Group B streptococcal bacteremia in non-pregnant adults.

BACKGROUND AND PURPOSE: An increasing incidence of group B streptococcus (GBS) infection in non-pregnant adults has been noted in recent years. To understand the incidence, clinical characteristics, and outcome of GBS bacteremia in non-pregnant adults, we conducted a retrospective study at a tertiary teaching hospital in Taiwan. METHODS: This retrospective analysis included 94 non-pregnant adults (age >/=18 years) with GBS bacteremia hospitalized between January 2001 and December 2003. RESULTS: The incidence of GBS bacteremia increased from 0.16 cases/1000 admissions in 2001 to 0.30 cases/1000 admissions in 2003 (p=0.017, chi-squared test for trend). The mean age of patients was 64.7 +/- 1.39 years. At least 1 underlying systemic disease was found in 81% of patients, with the most frequent being malignancy (43.6%), diabetes mellitus (42.6%), and liver cirrhosis (16%). The 2 major clinical syndromes were primary bacteremia (34%) and soft tissue infection (31.9%). The overall mortality rate was 20.2%. Staphylococcus aureus and Klebsiella pneumoniae were the 2 most common concurrently isolated bloodstream pathogens. Polymicrobial bacteremia, thrombocytopenia, and shock were independent risk factors for mortality in GBS bacteremia. CONCLUSIONS: The increasing incidence of GBS bacteremia is noteworthy, especially among patients with invasive infections. These infections are also responsible for substantial mortality in elderly patients with underlying diseases. Susceptibility testing indicated that penicillin G remains the drug of choice for GBS bacteremia.     

Group B streptococcal breast abscess

A 22-year-old women was admitted to the hospital with a large, tender supraareolar mass of her right breast. Cultures of the purulent aspirate yielded beta-hemolytic group B streptococcus. Surgical incision and drainage, together with therapy with erythromycin ethylsuccinate in this penicillin-allergic patient, resulted in cure. This is the first report, to our knowledge, of group B streptococcus causing human breast abscess.     

Group B streptococcal neuraminidase is actually a hyaluronidase.

The extracellular group B streptococcal enzyme described in numerous reports as a neuraminidase is really a hyaluronidase. Over the past 25 years, the enzyme was routinely assayed with bovine submaxillary mucin as the substrate and by the thiobarbituric acid procedure to measure released sialic acid. Characterization of the actual compound released by the enzyme revealed it to be an alpha,beta-unsaturated derivative of hyalobiuronic acid that was derived from hyaluronic acid contaminating the mucin preparation. Previous reports describing an association of elevated levels of extracellular neuraminidase with virulent strains of group B streptococci must be reevaluated with the recognition that the enzyme is really a hyaluronidase.     

Group B streptococcal endocarditis in Down's syndrome

A 36 year old man with Down's syndrome developed group B Streptococcal (subtype Ia) mitral endocarditis, which was complicated by widespread abscess formation. He was given antibiotics for one year, and no surgery was performed. Despite the underlying condition, the IgM response and the production of specific antibodies against the bacteria were normal.     

Group B streptococcal colonization patterns in mothers and their infants.

Maternity patients and their newborn infants were cultured for group B streptococci (GBS) at Tampa General Hospital, Tampa, Fla., from September 1982 to May 1983. Culture swabs were placed into Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and quantitated for GBS. A strong correlation was found between the numbers of GBS in the maternal vagina and the infant rectum. Infants symptomatic for early-onset GBS disease were delivered by mothers heavily colonized (greater than or equal to 3 X 10(4) GBS per swab) at the vagina. Such mothers were identified as GBS carriers by slide coagglutination and latex agglutination after their broth cultures had been incubated for 5 h. These data indicate that maternity patients at high risk of delivering infants heavily colonized with GBS and potentially symptomatic for early-onset GBS disease can be rapidly and selectively identified.     

Group G streptococcal endocarditis.

The group G streptococcus may be a more common human pathogen than previously recognized. A case of group G streptococcal endocarditis is reported and the 11 cases reported previously are reviewed. Group G endocarditis may have significant clinical and prognostic differences from endocarditis caused by the more commonly identified viridans or group D streptococci. Routine serologic grouping of beta-hemolytic streptococcal isolates from serious infections is warranted.     

Group B streptococcal soft tissue infections in non-pregnant adults

Skin and soft tissue infections are the most common presentations of invasive Streptococcus agalactiae infections. This study reviewed 71 patients in a medical centre in southern Taiwan with S. agalactiae soft tissue infections. The mortality rate was 7%, and 11% of patients lost their extremities following extensive tissue necrosis. Critical illness and the presence of cutaneous ulceration heralded a fatal prognosis. Risk-factors for amputation of limbs included advanced age, cutaneous ulceration and polymicrobial infection. It was concluded that invasive S. agalactiae soft tissue infections, as with infections caused by Streptococcus pyogenes, can also lead to substantial morbidity and mortality in non-pregnant adults.     

Group G streptococcal lymphadenitis in rats.

Group G streptococci which have been isolated from the oral flora of rats are also normal inhabitants of the human skin, oropharynx, gastrointestinal tract, and female genital tract. This group of streptococci can cause a wide variety of clinical diseases in humans, including septicemia, pharyngitis, endocarditis, pneumonia, and meningitis. Ten days after oral gavage with 7,12-dimethylbenz[a]anthracene, 12 of 22 two-month-old, female, outbred, viral-antibody-free rats presented with red ocular and nasal discharges and marked swelling of the cervical region. Various degrees of firm, nonpitting edema in the region of the cervical lymph nodes and salivary glands as well as pale mucous membranes and dehydration were observed. Pure cultures of beta-hemolytic streptococci were obtained from the cervical lymph nodes of three rats that were necropsied. A rapid latex test system identified the isolates to have group G-specific antigen. These streptococcal isolates fermented trehalose and lactose but not sorbitol and inulin and did not hydrolize sodium hippurate or bile esculin. A Voges-Proskauer test was negative for all six isolates. Serologic tests to detect the presence of immunoglobulin G antibody to rat viral pathogens and Mycoplasma pulmonis were negative. Histopathologic changes included acute necrotizing inflammation of the cervical lymph nodes with multiple large colonies of coccoid bacteria at the perimeter of the necrotiz zone. To our knowledge, this is the first report of naturally occurring disease attributed to group G streptococci in rats.     

Group B streptococcal beta-hemolysin expression is associated with injury of lung epithelial cells.

Group B streptococci (GBS) are the leading cause of serious bacterial infection in newborns. Early-onset disease is heralded by pneumonia and lung injury, and the lung may serve as a portal of entry for GBS into the bloodstream. To examine a potential role for GBS beta-hemolysin in lung epithelial injury, five wild-type strains varying in beta-hemolysin expression were chosen, along with five nonhemolytic (NH) and five hyperhemolytic (HH) variants of these strains derived by chemical or transposon mutagenesis. Monolayers of A549 alveolar epithelial cells were exposed to log-phase GBS or stabilized hemolysin extracts of GBS cultures, and cellular injury was assessed by lactate dehydrogenase (LDH) release and trypan blue nuclear staining. Whereas NH strains produced no detectable injury beyond baseline (medium alone), hemolysin-producing strains induced LDH release from A549 cells in direct correlation to their ability to lyse sheep erythrocytes. HH strains were also associated with marked increases in trypan blue nuclear staining of A549 monolayers. The extent of LDH release produced by HH strains was significantly reduced in the presence of dipalmitoyl phosphatidylcholine, a known inhibitor of hemolysin and the major phospholipid component of human surfactant. Electron microscopic studies of A549 cell monolayers exposed to HH GBS mutants revealed global loss of microvillus architecture, disruption of cytoplasmic and nuclear membranes, and marked swelling of the cytoplasm and organelles. We conclude that GBS hemolysin expression correlates with lung epithelial cell injury and may be important in the initial pathogenesis of early-onset disease, particularly when pulmonary surfactant is deficient.     

Group B streptococcal disease in the era of intrapartum antibiotic prophylaxis

BACKGROUND: Group B streptococcal infections are a leading cause of neonatal mortality, and they also affect pregnant women and the elderly. Many cases of the disease in newborns can be prevented by the administration of prophylactic intrapartum antibiotics. In the 1990s, prevention efforts increased. In 1996, consensus guidelines recommended use of either a risk-based or a screening-based approach to identify candidates for intrapartum antibiotics. To assess the effects of the preventive efforts, we analyzed trends in the incidence of group B streptococcal disease from 1993 to 1998. METHODS: Active, population-based surveillance was conducted in selected counties of eight states. A case was defined by the isolation of group B streptococci from a normally sterile site. Census and live-birth data were used to calculate the race-specific incidence of disease; national projections were adjusted for race. RESULTS: Disease in infants less than seven days old accounted for 20 percent of all 7867 group B streptococcal infections. The incidence of early-onset neonatal infections decreased by 65 percent, from 1.7 per 1000 live births in 1993 to 0.6 per 1000 in 1998. The excess incidence of early-onset disease in black infants, as compared with white infants, decreased by 75 percent. Projecting our findings to the entire United States, we estimate that 3900 early-onset infections and 200 neonatal deaths were prevented in 1998 by the use of intrapartum antibiotics. Among pregnant girls and women, the incidence of invasive group B streptococcal disease declined by 21 percent. The incidence among nonpregnant adults did not decline. CONCLUSIONS: Over a six-year period, there has been a substantial decline in the incidence of group B streptococcal disease in newborns, including a major reduction in the excess incidence of these infections in black infants. These improvements coincide with the efforts to prevent perinatal disease by the wider use of prophylactic intrapartum antibiotics.     

Group B streptococcal infections in children in a tertiary care hospital in southern Taiwan.

Group B Streptococcus (GBS) is widely recognized as a leading cause of neonatal sepsis and meningitis. Recently, GBS infections in older children have been increasingly noted. This retrospective study investigated the clinical features, distribution of serotypes, and antimicrobial susceptibility of GBS isolates in a tertiary care center in southern Taiwan over a 12-year period. GBS isolates recovered from various infected sites in 54 children treated from June 1991 through December 2002 were studied. These children were divided into those with disease onset of up to 3 months of age (group 1) and those with disease onset after 3 months of age (group 2). Patients in group 1 were subdivided into early-onset disease (EOD, <7 days of age, 7/30) and late-onset disease (LOD, > or =7 days to 3 months of age, 23/30). Sepsis (90% vs 8%; p<0.01) and meningitis (40% vs 4.2%; p<0.01) were observed more frequently in group 1, whereas urinary tract infection (UTI; 45.8% vs 6.7%; p<0.01) and acute tonsillitis (33.3% vs 0%; p<0.01) were noted more frequently in group 2. Underlying conditions were more common in group 2 than in group 1 (50% vs 10%; p<0.01), especially in patients with UTI. The most frequently encountered serotype was serotype III (56%). Patients in group 1, especially those with LOD, and those who had meningitis or sepsis, were prone to develop serotype III infections (p<0.05). All isolates were susceptible to penicillin G and cephalothin. About 50% of isolates were susceptible to erythromycin, azithromycin, and to clindamycin. In conclusion, GBS infection in children has different characteristics in different age groups. Serotype III is the most prevalent serotype in children. GBS isolates in southern Taiwan are still very susceptible to penicillin G.     

Group a streptococcal polysaccharide antigens

Cold trichloroacetic acid extracts of group A, type 3 streptococci were fractionated on Sephadex G50 and ECTEOLA cellulose columns. A glucose-N-acetylglucosamine polymer was isolated and shown by chemical, electrophoretic, and antigenic analysis to be distinct from the group A polysaccharide. The antigenic specificity was due to the glucosamine. A glycerol-phosphate-alanine-glucosamine teichoic acid polymer was isolated. The antigenic specificity was due to N-acetylglucosamine and d-alanine methyl ester, with the former possessing principal responsibility. The glucosamine and ester-linked alanine appear to be labile to the method of extraction and fractionation. Group A streptococcal whole cell antiserum, after adsorption with cells of a heterologous serological group and group A polysaccharide antigen, contained antibodies against both polymers.     

Group B streptococcal bacteremia in non-pregnant adults: results from two Korean centers

Patients with liver cirrhosis (LC) have impaired immunity and are, thus, predisposed to infection. Few studies have attempted to evaluate group B streptococcal (GBS) bacteremia in LC patients. A retrospective study of patients with GBS bacteremia was performed at the Dongguk University Ilsan Hospital and National Health Insurance Service Ilsan Hospital over a 13-year period (October 2000 to July 2013). During the study period, 97 patients with GBS bacteremia were enrolled. The median age of the patients was 67 years and 54 % were men. Among them, 23 (24 %) patients were classified as LC patients. The 30-day mortality rate of LC patients was significantly higher than that of patients with other diseases (26 % vs. 8 %, p?=?0.03). The multivariate analysis indicated that LC was associated with an increased risk of 30-day mortality [hazard ratio (HR) 5.0; 95 % confidence interval (CI) 1.53–16.3; p?=?0.008], as well as age (HR 1.07; 95 % CI 1.03–1.13; p?=?0.02) and high Pitt bacteremia score (HR 1.23; 95 % CI 1.02–1.46; p?=?0.03). The probability of survival at day 30 was significantly different for the Child–Pugh class C and the Child–Pugh classes A or B (44 % vs. 93 %, respectively; p?=?0.01 by the log-rank test). The mortality rates of LC patients with GBS bacteremia were significantly higher than those of patients with other diseases. The severity of hepatic dysfunction plays an important role in the development of adverse events. Cirrhosis-specific scores such as the Child–Pugh class might be useful for predicting the prognosis of GBS bacteremia in LC patients.