Infection with
Group B Streptococcus (
GBS), also known as
'Streptococcus agalactiaeStreptococcus agalactiae is a beta-hemolytic gram-positive streptococcus.-Identification:...
' and more colloquially as Strep B and group B Strep, can cause serious illness and sometimes
deathDeath is the termination of the biological functions that define a living organism. It refers to both a particular event and to the condition that results thereby. The true nature of the latter has for millennia been a central concern of the world's religious traditions and of philosophical...
, especially in newborn infants, the elderly, and patients with compromised immune systems. Group B streptococci are also prominent veterinary
pathogenA pathogen , infectious agent, or germ, is a biological agent that causes disease or illness to its host....
s, because they can cause bovine
mastitisMastitis is the inflammation of breast tissue.-Terminology:Popular usage of the term mastitis varies by geographic region. Outside the US it is commonly used for puerperal and nonpuerperal cases, in the US the term nonpuerperal mastitis is rarely used and alternative names such as duct ectasia,...
(
inflammationInflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a...
of the
udderAn udder is the mammary organ of female cattle and some other mammals, including goats and sheep. Udder care and hygiene in cows is important in milking, aiding uninterrupted and untainted milk production, and preventing mastitis. Products such as Bag Balm are used to soothe the chapped skin of...
) in dairy cows. The species name "agalactiae" meaning "no milk", alludes to this.
StreptococcusStreptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
is a
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
of spherical,
Gram-positiveGram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
bacteria of the
phylumIn biology, a phylum ["Phylum" is adopted from the Greek phylai, the clan-based voting groups in Greek city-states.] is a taxonomic rank below Kingdom and above Class...
FirmicutesThe Firmicutes are a phylum of bacteria, most of which have Gram-positive cell wall structure. A few, the Mollicutes or mycoplasmas, lack cell walls altogether and so do not respond to Gram staining, but still lack the second membrane found in other Gram-negative forms...
.
Infection with
Group B Streptococcus (
GBS), also known as
'Streptococcus agalactiaeStreptococcus agalactiae is a beta-hemolytic gram-positive streptococcus.-Identification:...
' and more colloquially as Strep B and group B Strep, can cause serious illness and sometimes
deathDeath is the termination of the biological functions that define a living organism. It refers to both a particular event and to the condition that results thereby. The true nature of the latter has for millennia been a central concern of the world's religious traditions and of philosophical...
, especially in newborn infants, the elderly, and patients with compromised immune systems. Group B streptococci are also prominent veterinary
pathogenA pathogen , infectious agent, or germ, is a biological agent that causes disease or illness to its host....
s, because they can cause bovine
mastitisMastitis is the inflammation of breast tissue.-Terminology:Popular usage of the term mastitis varies by geographic region. Outside the US it is commonly used for puerperal and nonpuerperal cases, in the US the term nonpuerperal mastitis is rarely used and alternative names such as duct ectasia,...
(
inflammationInflammation is the complex biological response of vascular tissues to harmful stimuli, such as pathogens, damaged cells, or irritants. Inflammation is a protective attempt by the organism to remove the injurious stimuli as well as initiate the healing process for the tissue. Inflammation is not a...
of the
udderAn udder is the mammary organ of female cattle and some other mammals, including goats and sheep. Udder care and hygiene in cows is important in milking, aiding uninterrupted and untainted milk production, and preventing mastitis. Products such as Bag Balm are used to soothe the chapped skin of...
) in dairy cows. The species name "agalactiae" meaning "no milk", alludes to this.
StreptococcusStreptococcus is a genus of spherical Gram-positive bacteria belonging to the phylum Firmicutes and the lactic acid bacteria group. Cellular division occurs along a single axis in these bacteria, and thus they grow in chains or pairs, hence the name — from Greek στρεπτος streptos, meaning...
is a
genusIn biology, a genus is a taxonomic unit used in the classification of living and fossil organisms. The term comes from Latin genus "descent, family, type, gender" , cognate with – genos, "race, stock, kin" ..In addition, genus is a taxonomic rank in the hierarchy In biology, a genus (plural:...
of spherical,
Gram-positiveGram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
bacteria of the
phylumIn biology, a phylum ["Phylum" is adopted from the Greek phylai, the clan-based voting groups in Greek city-states.] is a taxonomic rank below Kingdom and above Class...
FirmicutesThe Firmicutes are a phylum of bacteria, most of which have Gram-positive cell wall structure. A few, the Mollicutes or mycoplasmas, lack cell walls altogether and so do not respond to Gram staining, but still lack the second membrane found in other Gram-negative forms...
.
Streptococcus agalactiaeStreptococcus agalactiae is a beta-hemolytic gram-positive streptococcus.-Identification:...
is a
gram-positiveGram-positive bacteria are those that are stained dark blue or violet by Gram staining. This is in contrast to Gram-negative bacteria, which cannot retain the crystal violet stain, instead taking up the counterstain and appearing red or pink...
streptococcus characterized by the presence of Group B
Lancefield antigenRebecca Craighill Lancefield was a prominent American microbiologist. She joined the Rockefeller Institute for Medical Research in New York in 1918 and was associated to that institute throughout her long and outstanding career. Her bibliography comprises more than 50 publications published over...
, and so takes the name Group B Streptococcus.
Perinatal disease
Group B
Streptococcus (GBS) is a part of normal flora of the gut and genital tract and is found in 20-40% women. It may be harmful to both mother and the baby itself. Infection of this organism may result in neonatal death due to severe neonatal infection. It may also result in maternal death although this is only occasionally by causing uper genital tract infection which progresses to septicaemia. Carriage of the organism is asymptomatic.
Perinatal Group B Streptococcal Disease
25% of women are colonized with GBS in the vagina or rectum. Since the bacteria can come and go, testing for GBS is recommended by US public health protocols at the 36 week antenatal appointment of every pregnancy. The
vaginaThe vagina is a fibromuscular tubular tract leading from the uterus to the exterior of the body in female placental mammals and marsupials, or to the cloaca in female birds, monotremes, and some reptiles. Female insects and other invertebrates also have a vagina, which is the terminal part of the...
and
rectumThe rectum is the final straight portion of the large intestine in some mammals, and the gut in others, terminating in the anus. The human rectum is about 12 cm long...
are swabbed and cultures grown in enriched culture media. In the UK, cultures are not routinely grown at 36 weeks, but rather women are treated according to their risk in labor - antibiotics are given to women whose membranes are ruptured more than 18 hours and those who have fever. In some countries suboptimal culture methods are used, which result in up to half of women carrying GBS when swabbed, and being given a false-negative test result. Treatment of GBS positive women with intravenous penicillin at the onset of labor and then again at every sixth hour reduces early neonatal infection, but research has shown that treatment at least 2 hours prior to birth is also beneficial.
Where insufficient intravenous antibiotics are given before delivery, the baby may be given antibiotics immediately after birth, although evidence is inconclusive as to whether this is effective. Some maternity units take a watchful approach for 24–48 hours, only giving antibiotics if the baby shows any symptoms of infection, or if there is laboratory evidence on CBC or culture of infection. If a woman presents late in her prenatal period then there may be no time to grow cultures prior to labor, or she may present in active labor without documentation of prenatal care. In this situation, some clinicians advocate
empiricalThe word empirical denotes information gained by means of observation, experience, or experiment. A central concept in science and the scientific method is that all evidence must be empirical, or empirically based, that is, dependent on evidence or consequences that are observable by the senses...
antibiotic coverage of mother and baby, although most would only advocate antibiotics for the mother if other recognized risk factors were present.
Perinatal GBS disease prevention
Through collaborative efforts clinicians, researchers, professional organizations, parent advocacy groups, and the
public healthPublic health is "the science and art of preventing disease, prolonging life and promoting health through the organized efforts and informed choices of society, organizations, public and private, communities and individuals." It is concerned with threats to the overall health of a community based...
community developed recommendations for intrapartum prophylaxis to prevent Perinatal GBS disease. Many organizations have developed perinatal GBS disease
preventionPrevention refers to:* Preventive medicine* Hazard prevention, the process of risk study and elimination and mitigation in emergency management* Risk prevention* Risk management* Preventive maintenance* Crime prevention...
and education programs to reduce the
incidenceIncidence is a measure of the risk of developing some new condition within a specified period of time. Although sometimes loosely expressed simply as the number of new cases during some time period, it is better expressed as a proportion or a rate with a denominator.Incidence proportion is the...
of the disease. Information about the recommendations and the prevention programs can be found in
medical journalA medical journal is a scientific journal devoted to the field of medicine. Most medical journals are peer-reviewed. Medical journals commonly arose as the journal of societies, such as the precursor to the British Medical Association, and would originally be collections of letters sent to the...
s and on the
internetThe Internet is a global system of interconnected computer networks that use the standardized Internet Protocol Suite to serve billions of users worldwide...
.
External links