Moraxella catarrhalis
Encyclopedia
Moraxella catarrhalis is a fastidious, nonmotile, Gram-negative
, aerobic
, oxidase-positive
diplococcus
that can cause infection
s of the respiratory system
, middle ear
, eye
, central nervous system
and joint
s of humans.
are rod-shaped
and rarely caused infections in humans. However results from DNA hybridization studies and 16S
rRNA
sequence comparisons were used to justify inclusion of the species catarrhalis in the genus Moraxella. Consequently, the name Moraxella catarrhalis is currently preferred for these bacteria. Nevertheless, some in the medical field continue to call these bacteria Branhamella catarrhalis.
Moraxella is named after Victor Morax
, a Swiss ophthalmologist who first described this genus of bacteria. Catarrhalis is derived from catarrh
, originally a Greek
word meaning 'to flow down', describing the profuse discharge from eyes and nose typically associated with severe inflammation in colds.
are known to cause otitis media
, bronchitis
, sinusitis
, and laryngitis
. Elderly patients and long-term heavy smokers with chronic pulmonary disease
should be aware that M. catarrhalis is associated with bronchopneumonia
, as well as exacerbations of existing chronic obstructive pulmonary disease
(COPD).
The peak rate of colonisation by M. catarrhalis appears to occur at approximately 2 years of age, with a striking difference in colonization rates between children and adults (very high to very low).
M. Catarrhalis has recently been gaining attention as an emerging human pathogen. It has been identified as an important cause in branchopulmonary infection, causing infection through pulmonary aspiration
in the upper pulmonary tract. Additionally, it causes bacterial pneumonia
, especially in adults with a compromised immune system
. It has also been known to cause infective exacerbations in adults with chronic lung disease, and it is an important cause in acute sinusitis, maxillary sinusitis, bacteremia, meningitis, conjunctivitis, acute purulent irritation of chronic bronchitis
, urethritis
, septicemia (although this is rare), septic arthritis
(which is also a rare occurrence), as well as acute laryngitis
in adults and acute otitis media
in children. M. Catarrhalis is an opportunistic pulmonary invader, and causes harm especially in patients who have compromised immune systems or any underlying chronic (medicine).
in conjunction with bacteremia
, as shown in a case recorded by Philipp Melendez and Royce Johnson in 1991 in the Kern Medical Center in the University of California, Los Angeles
. Although there have been cases of bacteremia cased by M. Catarrhalis reported before, this was the first instance in which bacteremia caused by "M. Catarrhalis" was also associated with septic arthritis. A microbiological evaluation of the patient (a 41 year old male) revealed that "M. Catarrhalis" was the cause of the disease rather than Neisseria
as was previously believed. This was also the second case of M. Catarrhalis causing septic arthritis (although in the first case there was no mention of bacteremia).
Along with its relation to septic arthritis
, bacteremia
is also caused by M. Catarrhalis infection. However, bacteremia caused by M. Catarrhalis infection can range in severity from a slight fever to lethal sepsis
and an associated respiratory tract infection
) is usually also identified. In a 1995 case study by John Ioannidasa and his colleagues of bacteremia infections caused by M. Catarrhalis, there was a 21% mortality rate
among patients. However, this may have been due to a lack of knowledge about the bacterium because of its recent recognition as a pathogen
.
In this same study, an infection of high-grade bacteremia
was linked with the development of endocarditis
. However, the patients without endocarditis
in the case study has been related to the background of each patient, especially the existence of other illnesses and any possible immune impairments
they may or may not have. Also, although bacteremia caused by M. Catarrhalis has been infrequently reported, this may be due to a misdiagnosis or oversight because M. Catarrhalis was only recently (1990s) identified as an important pathogen
. Many chronic disease in patients with "M. Catarrhalis" bacteremia can be linked to the patients with immune defects
or respiratory debility
. Similarly, respiratory debility in patients with bacteremic pneumonia
caused by M. Cartarrhalis infection can be linked with increased rates of pharyngeal colonization
, enhancement of bacterial adherence to abnormal epithelium
, and increased susceptibility of pulmonary parenchyma
to infection.
, ampicillin
, and amoxicillin
.
Current research priorities involve trying to find a suitable vaccine
for this genotypically diverse organism, as well as determining factors involved with virulence e.g. complement resistance. Lipooligosaccharide
is considered one possible virulence factor
.
Since the recent recognition of M. Catarrhalis as an important pathogenic microbe
, there have been developments for a possible antibiotic
. According to a correspondence from T.G. Winstanley regarding M. Catarrhalis and antibiotics, Winstanley reported that a fraction of M. Catarrhalis strains seemed to be resistant to ampicillin
, which makes ampicillin and amoxicillin
inappropriate choices of antibiotic against M. Catarrhalis. Although all strains of M. Catarrhalis were susceptible to cotrimoxazole, erythromycin
, sulfadimidine
, and tetracycline, all strains of M. Catarrhalis were also resistant
to trimethoprim
. One of the reasons for the resistance of M. Catarrhalis to ampicillin
and trimethoprim
is because of the beta-lactamase
production, which is resistant to ampicillin
. Also, the resistance of M. Catarrhalis to other antibiotics may be attributed to beta-lactamase
as well because the use of these antibiotics has triggered an increase in development of beta-lactase
, which resists antibiotics.
However, a 1994 study by Merja Helminen and her colleagues has identified a large protein
on the surface of M. Catarrhalis that may serve as a target for protective antibodies
. This UspA (the designated antigen
) protein
is the first surface-exposed protein on M. Catarrhalis that can be a target for biologically active antibodies
, and therefore lead to a vaccination
. This protein
was also present in all of the strains that Helminen and her colleagues were able to test. The large size of the exposed protein
macromolecule
makes it similar to Neisseria gonorrhoeae
outer membrane protein macromolecular complex, which implies that UspA maybe be a single polypeptide chain.
Another study by Isobel Maciver in 1993 determined that active immunization
of M. Catarrhalis in the respiratory tract
allowed the control of the growth
of M. Catarrhalis and led to the development of serum antigens
. Also, there was an enhanced ability in the test subjects (mice) to clear M. Catarrhalis from their lungs
. Similarly, passive immunization
of M. Catarrhalis from the mice respiratory tracts
also enhanced the mice’s ability to clear the microbes from their lungs
, which means that serum antibodies
likely play a large role in the immunization
and protection of the respiratory tract
. Maciver also notes that along with outer membrane proteins that are consistent among different strains of M. Catarrhalis, there may also be a sort of sub-class specific IgG antibody response to certain outer membrane proteins. Therefore, the outer membrane antigens
of M. Catarrhalis also provide a possible vaccine
source. Also, there has also been the development of a bactericidal serum antibody
in response to the diseases
caused by M. Catarrhalis.
therapy or a so-called "watchful waiting
" approach. The great majority of clinical isolates of this organism produce beta-lactamase
s and are resistant to penicillin
. Resistance to trimethoprim
, trimethoprim-sulfamethoxazole
(TMP-SMX) and tetracycline have been reported. It is susceptible to fluoroquinolones, most second and third generation cephalosporin
s, erythromycin
and amoxicillin-clavulanate
.
that was associated with septic arthritis
, the microbe was cultured
, which revealed much about the morphology
of colonies of M. Catarrhalis as well as M. Catarrhalis itself. M. Catarrhalis is a large, kidney-shaped gram-negative
diplococcus
. It can be cultured
on blood and chocolate
agar plates after an aerobic
incubation at 37 degrees Celsius for 24 hours. Cultures
of the M. Catarrhalis bacterium revealed gray-white hemispheric colonies about 1 millimeter in diameter
. These colonies were fragile and easy to crumble and appeared to have a waxy
surface.
Also, the hockey puck test was applied to these M. Catarrhalis colonies. This is a test in which a wooden stick is used to try and push the colonies across the agar plate
. The M. Catarrhalis colonies scored positively on this test, which means that the colonies could be slid across the plate. Also, during this test there was no hemolysis
. Additionally, the colonies were not able to ferment
glucose
, sucrose
, maltose
, and lactose
. However, they were able to produce DNase. Finally, the cultures of the M. Catarrhalis tested positive for oxidase and catalyzation
of nitrate
, which is characteristic of M. Catarrhalis.
The recognition of M. Catarrhalis as a pathogenic bacterium
has led to studies for possible antibodies
against it. Therefore, these studies have led to a wider understanding of the composition of M. Catarrhalis. A study by Merja Helminen and her colleagues revealed that the outer membrane protein (OMP) profiles of different strains of M. Catarrhalis are incredibly similar to each other. Further, analyses of these outer membrane protein profiles with monoclonal antibodies (MAbs)
revealed that a few proteins
with similar molecular masses
in the different strains of M. Catarrhalis have cross-reactive
epitopes
. Their experiments also identified a surface-exposed protein
on M. Catarrhalis that has an unusually high molecular mass
. There has been a report that an 80kDa
outer membrane protein on M. Catarrhalis is immunogenic
and common to all nonencapsulated strands of M. Catarrhalis, which suggests that it may be used as an antigen
for immunization
.
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
, aerobic
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
, oxidase-positive
Oxidase test
The oxidase test is a test used in microbiology to determine if a bacterium produces certain cytochrome c oxidases. It uses disks impregnated with a reagent such as N,N,N′,N′-tetramethyl-p-phenylenediamine or N,N-Dimethyl-p-phenylenediamine , which is also a redox indicator...
diplococcus
Diplococcus
A diplococcus is a round bacterium that typically occurs in the form of two joined cells. Examples are Streptococcus pneumoniae, Moraxella catarrhalis, Neisseria gonorrhoeae and Neisseria meningitidis...
that can cause infection
Infection
An infection is the colonization of a host organism by parasite species. Infecting parasites seek to use the host's resources to reproduce, often resulting in disease...
s of the respiratory system
Respiratory system
The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...
, middle ear
Middle ear
The middle ear is the portion of the ear internal to the eardrum, and external to the oval window of the cochlea. The mammalian middle ear contains three ossicles, which couple vibration of the eardrum into waves in the fluid and membranes of the inner ear. The hollow space of the middle ear has...
, eye
Human eye
The human eye is an organ which reacts to light for several purposes. As a conscious sense organ, the eye allows vision. Rod and cone cells in the retina allow conscious light perception and vision including color differentiation and the perception of depth...
, central nervous system
Central nervous system
The central nervous system is the part of the nervous system that integrates the information that it receives from, and coordinates the activity of, all parts of the bodies of bilaterian animals—that is, all multicellular animals except sponges and radially symmetric animals such as jellyfish...
and joint
Joint
A joint is the location at which two or more bones make contact. They are constructed to allow movement and provide mechanical support, and are classified structurally and functionally.-Classification:...
s of humans.
History
M. catarrhalis was previously placed in a separate genus named Branhamella. The rationale for this was that other members of the genus MoraxellaMoraxella
Moraxella is a genus of Gram-negative bacteria in the Moraxellaceae family. It is named after the Swiss ophthalmologist Victor Morax. The organisms are short rods, coccobacilli or, as in the case of Moraxella catarrhalis, diplococci in morphology, with asaccharolytic, oxidase-positive and...
are rod-shaped
Bacilli
Bacilli refers to a taxonomic class of bacteria. It includes two orders, Bacillales and Lactobacillales, which contain several well-known pathogens like Bacillus anthracis .-Ambiguity:...
and rarely caused infections in humans. However results from DNA hybridization studies and 16S
16S ribosomal RNA
16S ribosomal RNA is a component of the 30S subunit of prokaryotic ribosomes. It is approximately 1.5kb in length...
rRNA
Ribosomal RNA
Ribosomal ribonucleic acid is the RNA component of the ribosome, the enzyme that is the site of protein synthesis in all living cells. Ribosomal RNA provides a mechanism for decoding mRNA into amino acids and interacts with tRNAs during translation by providing peptidyl transferase activity...
sequence comparisons were used to justify inclusion of the species catarrhalis in the genus Moraxella. Consequently, the name Moraxella catarrhalis is currently preferred for these bacteria. Nevertheless, some in the medical field continue to call these bacteria Branhamella catarrhalis.
Moraxella is named after Victor Morax
Victor Morax
Victor Morax was a French ophthalmologist who was born in Morges, Switzerland. He studied in Freiburg and Paris, and from 1891 to 1903 he worked at the Pasteur Institute in Paris...
, a Swiss ophthalmologist who first described this genus of bacteria. Catarrhalis is derived from catarrh
Catarrh
Catarrh is a disorder of inflammation of the mucous membranes in one of the airways or cavities of the body. It can result in a thick exudate of mucus and white blood cells caused by the swelling of the mucous membranes in the head in response to an infection...
, originally a Greek
Greek language
Greek is an independent branch of the Indo-European family of languages. Native to the southern Balkans, it has the longest documented history of any Indo-European language, spanning 34 centuries of written records. Its writing system has been the Greek alphabet for the majority of its history;...
word meaning 'to flow down', describing the profuse discharge from eyes and nose typically associated with severe inflammation in colds.
Clinical significance
Clinically, these bacteriaBacteria
Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...
are known to cause otitis media
Otitis media
Otitis media is inflammation of the middle ear, or a middle ear infection.It occurs in the area between the tympanic membrane and the inner ear, including a duct known as the eustachian tube. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache,...
, bronchitis
Bronchitis
Acute bronchitis is an inflammation of the large bronchi in the lungs that is usually caused by viruses or bacteria and may last several days or weeks. Characteristic symptoms include cough, sputum production, and shortness of breath and wheezing related to the obstruction of the inflamed airways...
, sinusitis
Sinusitis
Sinusitis is inflammation of the paranasal sinuses, which may be due to infection, allergy, or autoimmune issues. Most cases are due to a viral infection and resolve over the course of 10 days...
, and laryngitis
Laryngitis
Laryngitis is an inflammation of the larynx. It causes hoarse voice or the complete loss of the voice because of irritation to the vocal folds . Dysphonia is the medical term for a vocal disorder, of which laryngitis is one cause....
. Elderly patients and long-term heavy smokers with chronic pulmonary disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
should be aware that M. catarrhalis is associated with bronchopneumonia
Bronchopneumonia
Bronchopneumonia or bronchial pneumonia or "Bronchogenic pneumonia" is the acute inflammation of the walls of the bronchioles...
, as well as exacerbations of existing chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease
Chronic obstructive pulmonary disease , also known as chronic obstructive lung disease , chronic obstructive airway disease , chronic airflow limitation and chronic obstructive respiratory disease , is the co-occurrence of chronic bronchitis and emphysema, a pair of commonly co-existing diseases...
(COPD).
The peak rate of colonisation by M. catarrhalis appears to occur at approximately 2 years of age, with a striking difference in colonization rates between children and adults (very high to very low).
M. Catarrhalis has recently been gaining attention as an emerging human pathogen. It has been identified as an important cause in branchopulmonary infection, causing infection through pulmonary aspiration
Aspiration
Aspiration may refer to:In linguistics:*Aspirated consonant, a plosive pronounced with a strong burst of air*Debuccalization, the conversion of a consonant to [h] or [ʔ]*Voiceless glottal fricative In engine technology:...
in the upper pulmonary tract. Additionally, it causes bacterial pneumonia
Bacterial pneumonia
Bacterial pneumonia is a type of pneumonia caused by bacterial infection.-Sign and symptoms:*Fever*Rigors*Cough*Dyspnea*Chest pain*Pneumococcal pneumonia can cause Hemoptysis-Gram positive:...
, especially in adults with a compromised immune system
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
. It has also been known to cause infective exacerbations in adults with chronic lung disease, and it is an important cause in acute sinusitis, maxillary sinusitis, bacteremia, meningitis, conjunctivitis, acute purulent irritation of chronic bronchitis
Chronic bronchitis
Chronic bronchitis is a chronic inflammation of the bronchi in the lungs. It is generally considered one of the two forms of chronic obstructive pulmonary disease...
, urethritis
Urethritis
Urethritis is inflammation of the urethra. The most common symptom is painful or difficult urination.-Causes:The disease is classified as either gonococcal urethritis, caused by Neisseria gonorrhoeae, or non-gonococcal urethritis , most commonly caused by Chlamydia trachomatis...
, septicemia (although this is rare), septic arthritis
Septic arthritis
Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
(which is also a rare occurrence), as well as acute laryngitis
Laryngitis
Laryngitis is an inflammation of the larynx. It causes hoarse voice or the complete loss of the voice because of irritation to the vocal folds . Dysphonia is the medical term for a vocal disorder, of which laryngitis is one cause....
in adults and acute otitis media
Otitis media
Otitis media is inflammation of the middle ear, or a middle ear infection.It occurs in the area between the tympanic membrane and the inner ear, including a duct known as the eustachian tube. It is one of the two categories of ear inflammation that can underlie what is commonly called an earache,...
in children. M. Catarrhalis is an opportunistic pulmonary invader, and causes harm especially in patients who have compromised immune systems or any underlying chronic (medicine).
Link with Bacteremia
M. Catarrhalis has also been linked with septic arthritisSeptic arthritis
Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
in conjunction with bacteremia
Bacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
, as shown in a case recorded by Philipp Melendez and Royce Johnson in 1991 in the Kern Medical Center in the University of California, Los Angeles
University of California, Los Angeles
The University of California, Los Angeles is a public research university located in the Westwood neighborhood of Los Angeles, California, USA. It was founded in 1919 as the "Southern Branch" of the University of California and is the second oldest of the ten campuses...
. Although there have been cases of bacteremia cased by M. Catarrhalis reported before, this was the first instance in which bacteremia caused by "M. Catarrhalis" was also associated with septic arthritis. A microbiological evaluation of the patient (a 41 year old male) revealed that "M. Catarrhalis" was the cause of the disease rather than Neisseria
Neisseria
The Neisseria is a large genus of commensal bacteria that colonize the mucosal surfaces of many animals. Of the 11 species that colonize humans, only two are pathogens. N. meningitidis and N. gonorrhoeae often cause asymptomatic infections, a commensal-like behavior...
as was previously believed. This was also the second case of M. Catarrhalis causing septic arthritis (although in the first case there was no mention of bacteremia).
Along with its relation to septic arthritis
Septic arthritis
Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
, bacteremia
Bacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
is also caused by M. Catarrhalis infection. However, bacteremia caused by M. Catarrhalis infection can range in severity from a slight fever to lethal sepsis
Sepsis
Sepsis is a potentially deadly medical condition that is characterized by a whole-body inflammatory state and the presence of a known or suspected infection. The body may develop this inflammatory response by the immune system to microbes in the blood, urine, lungs, skin, or other tissues...
and an associated respiratory tract infection
Respiratory tract infection
Respiratory tract infection refers to any of a number of infectious diseases involving the respiratory tract. An infection of this type is normally further classified as an upper respiratory tract infection or a lower respiratory tract infection...
) is usually also identified. In a 1995 case study by John Ioannidasa and his colleagues of bacteremia infections caused by M. Catarrhalis, there was a 21% mortality rate
Mortality rate
Mortality rate is a measure of the number of deaths in a population, scaled to the size of that population, per unit time...
among patients. However, this may have been due to a lack of knowledge about the bacterium because of its recent recognition as a pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
.
In this same study, an infection of high-grade bacteremia
Bacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
was linked with the development of endocarditis
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...
. However, the patients without endocarditis
Endocarditis
Endocarditis is an inflammation of the inner layer of the heart, the endocardium. It usually involves the heart valves . Other structures that may be involved include the interventricular septum, the chordae tendineae, the mural endocardium, or even on intracardiac devices...
in the case study has been related to the background of each patient, especially the existence of other illnesses and any possible immune impairments
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
they may or may not have. Also, although bacteremia caused by M. Catarrhalis has been infrequently reported, this may be due to a misdiagnosis or oversight because M. Catarrhalis was only recently (1990s) identified as an important pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
. Many chronic disease in patients with "M. Catarrhalis" bacteremia can be linked to the patients with immune defects
Immune system
An immune system is a system of biological structures and processes within an organism that protects against disease by identifying and killing pathogens and tumor cells. It detects a wide variety of agents, from viruses to parasitic worms, and needs to distinguish them from the organism's own...
or respiratory debility
Respiratory system
The respiratory system is the anatomical system of an organism that introduces respiratory gases to the interior and performs gas exchange. In humans and other mammals, the anatomical features of the respiratory system include airways, lungs, and the respiratory muscles...
. Similarly, respiratory debility in patients with bacteremic pneumonia
Bacterial pneumonia
Bacterial pneumonia is a type of pneumonia caused by bacterial infection.-Sign and symptoms:*Fever*Rigors*Cough*Dyspnea*Chest pain*Pneumococcal pneumonia can cause Hemoptysis-Gram positive:...
caused by M. Cartarrhalis infection can be linked with increased rates of pharyngeal colonization
Human pharynx
The human pharynx is the part of the throat situated immediately posterior to the mouth and nasal cavity, and anterior to the esophagus and larynx. The human pharynx is conventionally divided into three sections: the nasopharynx , the oropharynx , and the laryngopharynx...
, enhancement of bacterial adherence to abnormal epithelium
Epithelium
Epithelium is one of the four basic types of animal tissue, along with connective tissue, muscle tissue and nervous tissue. Epithelial tissues line the cavities and surfaces of structures throughout the body, and also form many glands. Functions of epithelial cells include secretion, selective...
, and increased susceptibility of pulmonary parenchyma
Pulmonary contusion
A pulmonary contusion is a contusion of the lung, caused by chest trauma. As a result of damage to capillaries, blood and other fluids accumulate in the lung tissue. The excess fluid interferes with gas exchange, potentially leading to inadequate oxygen levels...
to infection.
Antibiotic Resistance
M. Catarrhalis can be treated with antibiotics, but it is commonly resistant to penicillinPenicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
, ampicillin
Ampicillin
Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
, and amoxicillin
Amoxicillin
Amoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...
.
Current research priorities involve trying to find a suitable vaccine
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...
for this genotypically diverse organism, as well as determining factors involved with virulence e.g. complement resistance. Lipooligosaccharide
Lipooligosaccharide
Lipooligosaccharide , a potent endotoxin, causes:* Petechiae,* Purpura,* Waterhouse-Friderichsen syndrome,* Septic shockLipooligosaccharides are naturally occurring variants of the more common glycolipid, lipopolysaccharide...
is considered one possible virulence factor
Virulence factor
Virulence factors are molecules expressed and secreted by pathogens that enable them to achieve the following:* colonization of a niche in the host...
.
Since the recent recognition of M. Catarrhalis as an important pathogenic microbe
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
, there have been developments for a possible antibiotic
Antibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
. According to a correspondence from T.G. Winstanley regarding M. Catarrhalis and antibiotics, Winstanley reported that a fraction of M. Catarrhalis strains seemed to be resistant to ampicillin
Ampicillin
Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
, which makes ampicillin and amoxicillin
Amoxicillin
Amoxicillin , formerly amoxycillin , and abbreviated amox, is a moderate-spectrum, bacteriolytic, β-lactam antibiotic used to treat bacterial infections caused by susceptible microorganisms. It is usually the drug of choice within the class because it is better absorbed, following oral...
inappropriate choices of antibiotic against M. Catarrhalis. Although all strains of M. Catarrhalis were susceptible to cotrimoxazole, erythromycin
Erythromycin
Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
, sulfadimidine
Sulfadimidine
Sulfadimidine or sulfamethazine, is a sulfonamide antibacterial.There are non-standardized abbreviations for it as "sulfadimidine" and as "sulfamethazine"...
, and tetracycline, all strains of M. Catarrhalis were also resistant
Antibiotic resistance
Antibiotic resistance is a type of drug resistance where a microorganism is able to survive exposure to an antibiotic. While a spontaneous or induced genetic mutation in bacteria may confer resistance to antimicrobial drugs, genes that confer resistance can be transferred between bacteria in a...
to trimethoprim
Trimethoprim
Trimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections.It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
. One of the reasons for the resistance of M. Catarrhalis to ampicillin
Ampicillin
Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
and trimethoprim
Trimethoprim
Trimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections.It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
is because of the beta-lactamase
Beta-lactamase
Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...
production, which is resistant to ampicillin
Ampicillin
Ampicillin is a beta-lactam antibiotic that has been used extensively to treat bacterial infections since 1961. Until the introduction of ampicillin by the British company Beecham, penicillin therapies had only been effective against Gram-positive organisms such as staphylococci and streptococci...
. Also, the resistance of M. Catarrhalis to other antibiotics may be attributed to beta-lactamase
Beta-lactamase
Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...
as well because the use of these antibiotics has triggered an increase in development of beta-lactase
Beta-lactamase
Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...
, which resists antibiotics.
However, a 1994 study by Merja Helminen and her colleagues has identified a large protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
on the surface of M. Catarrhalis that may serve as a target for protective antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
. This UspA (the designated antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
) protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
is the first surface-exposed protein on M. Catarrhalis that can be a target for biologically active antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
, and therefore lead to a vaccination
Vaccination
Vaccination is the administration of antigenic material to stimulate the immune system of an individual to develop adaptive immunity to a disease. Vaccines can prevent or ameliorate the effects of infection by many pathogens...
. This protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
was also present in all of the strains that Helminen and her colleagues were able to test. The large size of the exposed protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
macromolecule
Macromolecule
A macromolecule is a very large molecule commonly created by some form of polymerization. In biochemistry, the term is applied to the four conventional biopolymers , as well as non-polymeric molecules with large molecular mass such as macrocycles...
makes it similar to Neisseria gonorrhoeae
Neisseria gonorrhoeae
Neisseria gonorrhoeae, also known as gonococci , or gonococcus , is a species of Gram-negative coffee bean-shaped diplococci bacteria responsible for the sexually transmitted infection gonorrhea.N...
outer membrane protein macromolecular complex, which implies that UspA maybe be a single polypeptide chain.
Another study by Isobel Maciver in 1993 determined that active immunization
Active immunization
Active immunization is the induction of immunity after exposure to an antigen. Antibodies are created by the recipient and may be stored permanently....
of M. Catarrhalis in the respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
allowed the control of the growth
Bacterial growth
250px|right|thumb|Growth is shown as L = log where numbers is the number of colony forming units per ml, versus T Bacterial growth is the division of one bacterium into two daughter cells in a process called binary fission. Providing no mutational event occurs the resulting daughter cells are...
of M. Catarrhalis and led to the development of serum antigens
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
. Also, there was an enhanced ability in the test subjects (mice) to clear M. Catarrhalis from their lungs
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
. Similarly, passive immunization
Passive immunity
Passive immunity is the transfer of active humoral immunity in the form of readymade antibodies, from one individual to another. Passive immunity can occur naturally, when maternal antibodies are transferred to the fetus through the placenta, and can also be induced artificially, when high levels...
of M. Catarrhalis from the mice respiratory tracts
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
also enhanced the mice’s ability to clear the microbes from their lungs
Lung
The lung is the essential respiration organ in many air-breathing animals, including most tetrapods, a few fish and a few snails. In mammals and the more complex life forms, the two lungs are located near the backbone on either side of the heart...
, which means that serum antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
likely play a large role in the immunization
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an agent ....
and protection of the respiratory tract
Respiratory tract
In humans the respiratory tract is the part of the anatomy involved with the process of respiration.The respiratory tract is divided into 3 segments:*Upper respiratory tract: nose and nasal passages, paranasal sinuses, and throat or pharynx...
. Maciver also notes that along with outer membrane proteins that are consistent among different strains of M. Catarrhalis, there may also be a sort of sub-class specific IgG antibody response to certain outer membrane proteins. Therefore, the outer membrane antigens
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
of M. Catarrhalis also provide a possible vaccine
Vaccine
A vaccine is a biological preparation that improves immunity to a particular disease. A vaccine typically contains an agent that resembles a disease-causing microorganism, and is often made from weakened or killed forms of the microbe or its toxins...
source. Also, there has also been the development of a bactericidal serum antibody
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
in response to the diseases
Disease
A disease is an abnormal condition affecting the body of an organism. It is often construed to be a medical condition associated with specific symptoms and signs. It may be caused by external factors, such as infectious disease, or it may be caused by internal dysfunctions, such as autoimmune...
caused by M. Catarrhalis.
Treatment
Treatment options include antibioticAntibiotic
An antibacterial is a compound or substance that kills or slows down the growth of bacteria.The term is often used synonymously with the term antibiotic; today, however, with increased knowledge of the causative agents of various infectious diseases, antibiotic has come to denote a broader range of...
therapy or a so-called "watchful waiting
Watchful waiting
Watchful waiting is an approach to a medical problem in which time is allowed to pass before medical intervention or therapy is used. During this time, repeated testing may be performed....
" approach. The great majority of clinical isolates of this organism produce beta-lactamase
Beta-lactamase
Beta-lactamases are enzymes produced by some bacteria and are responsible for their resistance to beta-lactam antibiotics like penicillins, cephamycins, and carbapenems . These antibiotics have a common element in their molecular structure: a four-atom ring known as a beta-lactam...
s and are resistant to penicillin
Penicillin
Penicillin is a group of antibiotics derived from Penicillium fungi. They include penicillin G, procaine penicillin, benzathine penicillin, and penicillin V....
. Resistance to trimethoprim
Trimethoprim
Trimethoprim is a bacteriostatic antibiotic mainly used in the prophylaxis and treatment of urinary tract infections.It belongs to the class of chemotherapeutic agents known as dihydrofolate reductase inhibitors...
, trimethoprim-sulfamethoxazole
Co-trimoxazole
Trimethoprim/sulfamethoxazole or co-trimoxazole is a sulfonamide antibiotic combination of trimethoprim and sulfamethoxazole, in the ratio of 1 to 5, used in the treatment of a variety of bacterial infections.The name co-trimoxazole is the British Approved Name, and has been marketed worldwide...
(TMP-SMX) and tetracycline have been reported. It is susceptible to fluoroquinolones, most second and third generation cephalosporin
Cephalosporin
The cephalosporins are a class of β-lactam antibiotics originally derived from Acremonium, which was previously known as "Cephalosporium".Together with cephamycins they constitute a subgroup of β-lactam antibiotics called cephems.-Medical use:...
s, erythromycin
Erythromycin
Erythromycin is a macrolide antibiotic that has an antimicrobial spectrum similar to or slightly wider than that of penicillin, and is often used for people who have an allergy to penicillins. For respiratory tract infections, it has better coverage of atypical organisms, including mycoplasma and...
and amoxicillin-clavulanate
Co-amoxiclav
Amoxicillin/clavulanic acid or co-amoxiclav is a combination antibiotic consisting of amoxicillin trihydrate, a β-lactam antibiotic, and potassium clavulanate, a β-lactamase inhibitor...
.
Cellular morphology and biochemistry
During the first reported case of M. Catarrhalis causing bacteremiaBacteremia
Bacteremia is the presence of bacteria in the blood. The blood is normally a sterile environment, so the detection of bacteria in the blood is always abnormal....
that was associated with septic arthritis
Septic arthritis
Septic arthritis is the purulent invasion of a joint by an infectious agent which produces arthritis. People with artificial joints are more at risk than the general population but have slightly different symptoms, are infected with different organisms and require different treatment. Septic...
, the microbe was cultured
Microbiological culture
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
, which revealed much about the morphology
Morphology (biology)
In biology, morphology is a branch of bioscience dealing with the study of the form and structure of organisms and their specific structural features....
of colonies of M. Catarrhalis as well as M. Catarrhalis itself. M. Catarrhalis is a large, kidney-shaped gram-negative
Gram-negative
Gram-negative bacteria are bacteria that do not retain crystal violet dye in the Gram staining protocol. In a Gram stain test, a counterstain is added after the crystal violet, coloring all Gram-negative bacteria with a red or pink color...
diplococcus
Diplococcus
A diplococcus is a round bacterium that typically occurs in the form of two joined cells. Examples are Streptococcus pneumoniae, Moraxella catarrhalis, Neisseria gonorrhoeae and Neisseria meningitidis...
. It can be cultured
Microbiological culture
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
on blood and chocolate
Chocolate agar
Chocolate agar - is a non-selective, enriched growth medium. It is a variant of the blood agar plate. It contains red blood cells, which have been lysed by heating very slowly to 56 °C. Chocolate agar is used for growing fastidious respiratory bacteria, such as Haemophilus influenzae...
agar plates after an aerobic
Aerobic organism
An aerobic organism or aerobe is an organism that can survive and grow in an oxygenated environment.Faculitative anaerobes grow and survive in an oxygenated environment and so do aerotolerant anaerobes.-Glucose:...
incubation at 37 degrees Celsius for 24 hours. Cultures
Microbiological culture
A microbiological culture, or microbial culture, is a method of multiplying microbial organisms by letting them reproduce in predetermined culture media under controlled laboratory conditions. Microbial cultures are used to determine the type of organism, its abundance in the sample being tested,...
of the M. Catarrhalis bacterium revealed gray-white hemispheric colonies about 1 millimeter in diameter
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the center of the circle and whose endpoints are on the circle. The diameters are the longest chords of the circle...
. These colonies were fragile and easy to crumble and appeared to have a waxy
Waxy
Waxy is an American stoner rock band. The power trio consists of frontman Robert Owen , bassist Owen Street and drummer Sean Landerra. Following their 2005 self-titled debut, 2007 saw the release of their second effort Chainsaw Holiday, which featured guest appearances by Alfredo Hernández, Jesse...
surface.
Also, the hockey puck test was applied to these M. Catarrhalis colonies. This is a test in which a wooden stick is used to try and push the colonies across the agar plate
Agar plate
An agar plate is a Petri dish that contains a growth medium used to culture microorganisms or small plants like the moss Physcomitrella patens.Selective growth compounds may also be added to the media, such as antibiotics....
. The M. Catarrhalis colonies scored positively on this test, which means that the colonies could be slid across the plate. Also, during this test there was no hemolysis
Hemolysis
Hemolysis —from the Greek meaning "blood" and meaning a "loosing", "setting free" or "releasing"—is the rupturing of erythrocytes and the release of their contents into surrounding fluid...
. Additionally, the colonies were not able to ferment
Fermentation (biochemistry)
Fermentation is the process of extracting energy from the oxidation of organic compounds, such as carbohydrates, using an endogenous electron acceptor, which is usually an organic compound. In contrast, respiration is where electrons are donated to an exogenous electron acceptor, such as oxygen,...
glucose
Glucose
Glucose is a simple sugar and an important carbohydrate in biology. Cells use it as the primary source of energy and a metabolic intermediate...
, sucrose
Sucrose
Sucrose is the organic compound commonly known as table sugar and sometimes called saccharose. A white, odorless, crystalline powder with a sweet taste, it is best known for its role in human nutrition. The molecule is a disaccharide composed of glucose and fructose with the molecular formula...
, maltose
Maltose
Maltose , or malt sugar, is a disaccharide formed from two units of glucose joined with an αbond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α bond. Maltose is the second member of an important biochemical series of glucose chains....
, and lactose
Lactose
Lactose is a disaccharide sugar that is found most notably in milk and is formed from galactose and glucose. Lactose makes up around 2~8% of milk , although the amount varies among species and individuals. It is extracted from sweet or sour whey. The name comes from or , the Latin word for milk,...
. However, they were able to produce DNase. Finally, the cultures of the M. Catarrhalis tested positive for oxidase and catalyzation
Catalysis
Catalysis is the change in rate of a chemical reaction due to the participation of a substance called a catalyst. Unlike other reagents that participate in the chemical reaction, a catalyst is not consumed by the reaction itself. A catalyst may participate in multiple chemical transformations....
of nitrate
Nitrate
The nitrate ion is a polyatomic ion with the molecular formula NO and a molecular mass of 62.0049 g/mol. It is the conjugate base of nitric acid, consisting of one central nitrogen atom surrounded by three identically-bonded oxygen atoms in a trigonal planar arrangement. The nitrate ion carries a...
, which is characteristic of M. Catarrhalis.
The recognition of M. Catarrhalis as a pathogenic bacterium
Pathogenic bacteria
Pathogenic bacteria are bacteria that cause bacterial infection. This article deals with human pathogenic bacteria.Although the vast majority of bacteria are harmless or beneficial, quite a few bacteria are pathogenic...
has led to studies for possible antibodies
Antibody
An antibody, also known as an immunoglobulin, is a large Y-shaped protein used by the immune system to identify and neutralize foreign objects such as bacteria and viruses. The antibody recognizes a unique part of the foreign target, termed an antigen...
against it. Therefore, these studies have led to a wider understanding of the composition of M. Catarrhalis. A study by Merja Helminen and her colleagues revealed that the outer membrane protein (OMP) profiles of different strains of M. Catarrhalis are incredibly similar to each other. Further, analyses of these outer membrane protein profiles with monoclonal antibodies (MAbs)
Monoclonal antibodies
Monoclonal antibodies are monospecific antibodies that are the same because they are made by identical immune cells that are all clones of a unique parent cell....
revealed that a few proteins
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
with similar molecular masses
Molecular mass
The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass unit u...
in the different strains of M. Catarrhalis have cross-reactive
Cross-reactivity
Cross-reactivity is the reaction between an antibody and an antigen that differs from the immunogen. It is sometimes also referred to as crossimmunity or cross-protective immunity...
epitopes
Epitope
An epitope, also known as antigenic determinant, is the part of an antigen that is recognized by the immune system, specifically by antibodies, B cells, or T cells. The part of an antibody that recognizes the epitope is called a paratope...
. Their experiments also identified a surface-exposed protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
on M. Catarrhalis that has an unusually high molecular mass
Molecular mass
The molecular mass of a substance is the mass of one molecule of that substance, in unified atomic mass unit u...
. There has been a report that an 80kDa
Atomic mass unit
The unified atomic mass unit or dalton is a unit that is used for indicating mass on an atomic or molecular scale. It is defined as one twelfth of the rest mass of an unbound neutral atom of carbon-12 in its nuclear and electronic ground state, and has a value of...
outer membrane protein on M. Catarrhalis is immunogenic
Immunogenicity
Immunogenicity is the ability of a particular substance, such as an antigen or epitope, to provoke an immune response in the body of a human or animal.- Immunogenicity :The ability to induce humoral and/or cell-mediated immune responses....
and common to all nonencapsulated strands of M. Catarrhalis, which suggests that it may be used as an antigen
Antigen
An antigen is a foreign molecule that, when introduced into the body, triggers the production of an antibody by the immune system. The immune system will then kill or neutralize the antigen that is recognized as a foreign and potentially harmful invader. These invaders can be molecules such as...
for immunization
Immunization
Immunization, or immunisation, is the process by which an individual's immune system becomes fortified against an agent ....
.