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PubMed1983

Selective pigment medium for Streptococcus agalactiae.

Increased awareness of the importance of Streptococcus agalactiae (Group B streptococcus) in neonatal morbidity and mortality has demonstrated the need for a selective and differential primary plating medium. In this report we describe a selective pigment medium containing colistin and nalidixic acid that allows presumptive identification of S. agalactiae from the primary plate, even when specimens are polymicrobic. A preliminary study compared the value of three media for pigment production by 137 known S. agalactiae strains. This was followed by a clinical laboratory trial using the best of these pigment media at an obstetric hospital in which 581 specimens from neonates, female reproductive tracts, and urinary tracts were screened. Subsequent to the clinical laboratory trial, an epidemiological investigation using the selective pigment medium was conducted on a mother/infant population. Of the 1,331 specimens screened for S. agalactiae, 75 (5.6%) were positive on 5% sheep blood agar and 79 (5.9%) were positive on the selective pigment medium.

Adult↗

PubMed1986

Coaggregation between Actinomyces viscosus with Streptococcus pyogenes and Streptococcus agalactiae.

Interbacterial coaggregation between Actinomyces viscosus indigenous to the human mouth and Streptococcus pyogenes and Streptococcus agalactiae was studied. Fifteen of twenty-six strains of Streptococcus pyogenes and thirteen of thirty-one Streptococcus agalactiae showed a coaggregation with Actinomyces viscosus strain. The results show that the coaggregation mechanism required calcium and was dependent on pH. Some coaggregations were inhibited by 0.06 M. lactose and by 1 M. NaCl.

Actinomyces↗

PubMed2004

Serotype III Streptococcus agalactiae from bovine milk and human neonatal infections.

Streptococcus agalactiae (group B streptococcus [GBS]) causes invasive human infections and bovine mastitis. This study examined the genetic relationship between bovine and human serotype III GBS by using molecular techniques that classify human serotype III GBS into four distinct phylogenetic lineages. Bovine serotype III GBS were largely contained in two lineages, which are distinct from the two major lineages (restriction digest types III-2 and III-3) that infect human neonates. One of the bovine lineages closely resembles the human III-1 lineage, whose members occasionally cause human neonatal infections. The bovine strains in the other lineage characteristically have an initiation factor IF2 gene (infB) H allele and multilocus sequence types that are not found in human GBS strains. Evidence suggests that this "H allele" lineage is related to the human III-3 lineage. These results support the assertion that human and bovine GBS are largely unrelated and provide further insight into the genetic relation between human and bovine GBS.

Alleles↗

PubMed1991

The kinetics of inflammation and phagocytosis during bovine mastitis induced by Streptococcus agalactiae bearing the protein X.

The protein X of Streptococcus agalactiae is a surface antigen borne by a high proportion of strains isolated from bovine mastitis. We have tested the capacity of two strains of X-bearing Streptococcus agalactiae to induce mastitis in dairy cows. The reference X-strain (411.07) produced an intramammary infection with local clinical signs in the three inoculated quarters. Another X-bearing strain (443.31) of bovine origin produced infection in all 11 quarters inoculated with only 25 or 85 colony-forming units. In naive cows, strain 433.31 induced less exudation of plasma into the milk, shedding of bacteria, macroscopic alteration, and a lower somatic cell count (SCC) than did the reference strain. Only one quarter spontaneously eliminated the infection before antibiotic treatment 9 days after inoculation. The serum of all the cows contained naturally acquired or induced antibodies to the challenge strain (443.31) and possessed opsonic activity. Before inflammation occurred, the milk was almost devoid of antibody or opsonic activities. The early phase of infection was characterized by rapid multiplication of streptococci in the milk, followed by a sharp drop in bacterial counts concomitant with the onset of inflammation. Three cows immunized with protein X displayed higher SCC and bactericidal activity in milk from the inoculated quarter at the onset of inflammation than non-immunized cows. Two of the three immunized cows underwent an early and transient febrile episode and eliminated the infection.

Animals↗

PubMed1996

[Streptococcus agalactiae infection in adults. Presentation of 3 cases].

The Streptococcus of the B group was considered during many years, as a women's prelabor pathogen and neonatus. Lastly an increase of the infections is observed, for this germ in adults, without being in connection with the pregnancy. The Streptococcus agalactiae, affect above all to patients, with any type of illness underlying. The most susceptible are the diabetics and focus of more habitual infection, the soft tissues and the bone. We described three cases of infection by Streptococcus agalactiae in adults picked up during two years, in a Service of Internal Medicine with 51 beds. We are revised Medline, from the year 1985, until 1995, confirming the drop incidence of cases.

Aged↗

PubMed1988

Evaluation of the Rapid Mastitis Test for identification of Staphylococcus aureus and Streptococcus agalactiae isolated from bovine mammary glands.

A latex agglutination test system (Rapid Mastitis Test [RMT]; Immucell, Portland, Maine) containing reagents for the identification of Staphylococcus aureus and Streptococcus agalactiae from bovine intramammary infections was evaluated with 527 staphylococcal and 267 streptococcal isolates. The RMT Staphylococcus aureus reagent detected 94.2% of 242 Staphylococcus aureus isolates, 80% of 25 Staphylococcus intermedius isolates, and 42.8% of 21 tube coagulase-positive Staphylococcus hyicus isolates. All Streptococcus agalactiae isolates were correctly identified by the RMT Streptococcus agalactiae reagent. Cross-reactions were observed with one Streptococcus dysgalactiae and three Streptococcus uberis strains. The RMT was found to be an acceptable method for the detection of Staphylococcus aureus and Streptococcus agalactiae isolated from bovine mammary glands. The occurrence of coagulase-positive staphylococci other than Staphylococcus aureus requires biochemical testing for species level identification.

Animals↗

PubMed2004

Group B Streptococcus (Streptococcus agalactiae) peritonitis associated with continuous ambulatory peritoneal dialysis (CAPD).

Streptococcus agalactiae typically induces serious infections in pregnant women and newborns. Nonpregnant adult patients can also be infected and mortality rate exceeds 40%. CAPD peritonitis is very rarely induced by S. agalactiae. Seven cases have been described previously and all had a very severe course, which included bacteremia, septic shock and death. A 27-year-old male with end-stage renal disease due to membranoprolipherative glomerulonephritis type I, who was on CAPD for 17 months, was admitted with the clinical and laboratory picture of CAPD peritonitis. Severe abdominal pain, shaking chills and fever 38.5 microC were also observed at presentation. Streptococcus agalactiae was isolated from the peritoneal fluid and blood culture was sterile. Under treatment with ceftazidime and tobramycin (i.p.) and vancomycin (i.v.) cultures became negative after 48 hours, abdominal symptoms resolved after 12 days and WBC count in the dialysate normalized after 14 days. As a possible source of infection the patient's partner was shown to be a vaginal carrier of a clone of S. agalactiae identical to that isolated in the peritoneal fluid. S. agalactiae is a rare cause of CAPD peritonitis with potentially very serious consequences. Anal or genital tract colonization is, in general, the source of contamination with S. agalactiae. The microbiological findings in the case presented here suggest that colonization of the patient or of his close environment may be important in the pathogenesis of S. agalactiae-induced CAPD peritonitis.

Adult↗

PubMed2005

Serotype distribution and mother-to-baby transmission rate of Streptococcus agalactiae among expectant mothers in Kuwait.

INTRODUCTION: Streptococcus agalactiae, also known as Group B Streptococcus (GBS), is a formidable pathogen that is commonly responsible for early-onset and late-onset infections with high morbidity and mortality in the neonatal period. Since this organism is usually acquired via the mother's birth canal during labor, this study investigated the maternal carriage rate, mother-to-baby transmission rate, and the common GBS serotypes found among expectant mothers and their babies in Kuwait. METHODS: The setting was the Maternity Hospital, Kuwait. Low vaginal-anorectal swabs (LVRS) and urine specimens were collected from 847 pregnant women during labor. Ear and umbilical swabs from their new-born babies were also collected. Each specimen was cultured on selective Todd-Hewitt media. Isolates were identified and serotyped by established methods. RESULTS: Of the 847 mothers, 124 (14.6%) were colonized and 74 (8.7%) babies were colonized, mainly at the umbilicus. The 124 GBS-positive mothers gave birth to 44 babies that were colonized by GBS at one or both sites, which corresponds to a mother-to-baby transmission rate of (35.5%). A total of 193 isolates were serotyped. The majority of the GBS isolates belonged to serotypes III (47; 24.3%), V (42; 21.8%), Ia (25; 12.9%), II and VI (15; 7.8%) each, and VII (11; 5.7%). Only 4 (2.1%) and 1 (0.5%) isolates belonged to serotypes Ib and IV respectively. No isolate belonged to serotype VIII and 33 (17.1%) were non-typable (NT).

Female↗

PubMed1996

[Screening of Streptococcus agalactiae (group B) in the perinatal period].

OBJECTIVE: To determine the carriage rate of Streptococcus agalactiae in a group of pregnant women and evaluate its role in a neonatal infections. DESIGN: Prospective study between December 1992 and May 1993. SETTING: University hospital. PARTICIPANTS: 166 patients aged 17 to 41 years (m = 28 yrs) with a gestational age of 32 to 42 wks (m = 39.99 +/- 1.73) were admitted to the delivery suite. All patients had a vaginal swab on admission before any lavage. RESULTS: The recovery rate of Streptococcus agalactiae (group B) was found to be 7.8% (13/166) in our population. Twelve of the thirteen newborn to colonized mothers (92%) were term newborn as compared to 141 of 153 (92.1%) newborn to non-colonized mothers (p = 0.72). Three of thirteen (23%) colonized mothers had premature rupture of membranes and 23% (3/13) had prolonged labor > 12 h as compared to of 38 (25.1%) and 8 (5.1%) non-colonized mothers (respectively p = 0.58; NS; p = 0.035). No intra-partum fever was reported. All neonates born to colonized mothers had a birth weight > 2,800 g, an average Apgar score of 8.6 while neonates of non-colonized women had a weight > 2,800 g in 89.4% of cases and an average Apgar of 8.8 (p = 0.9). Two (15.4%) newborn infants born to colonized mothers had an early neonatal infection: one had a pneumonia and had a favorable outcome, the other one developed sepsis and meningitis and died on day 3. CONCLUSION: Despite the low rate of Streptococcus agalactiae (group B) colonization (found in our population), regular identification of the organism is recommended because of the high risk of neonatal infection with a high mortality. Further studies on a larger group are needed to confirm such an approach.

Adolescent↗

PubMed1986

Monoclonal antibodies produced to Streptococcus agalactiae.

Two monoclonal antibodies produced against Streptococcus agalactiae were studied for their specificity and sensitivity. Both reacted strongly in the enzyme-linked immunosorbent assay and indirect fluorescent antibody test with S agalactiae, but did not react with other gram-positive organisms frequently found in test herds in Mississippi. A procedure for using monoclonal antibodies in the detection of S agalactiae-infected milk samples is proposed.

Animals↗

PubMed2003

Evaluation of the surveillance program of Streptococcus agalactiae in Danish dairy herds.

The aim of this study was to evaluate the Danish surveillance program of Streptococcus agalactiae in dairy herds with respect to 1) fluctuation over time of the presence of S. agalactiae in bulk tank milk, 2) sensitivity and specificity of the bacteriological method used, and 3) contamination of bulk tank milk samples with milk from other herds. From June to September 1996, bulk tank milk was sampled from 100 Danish dairy herds seven times, with intervals of 2 wk. The samples were examined for the presence of S. agalactiae by four different methods: 1) by the method approved for the program, 2) after ultrasonic treatment of the milk before examination, 3) after freezing down the milk before examination, and 4) after selective preparation of the milk. Selected strains of S. agalactiae were examined by restriction fragment length polymorphism of the gene encoding rRNA to discriminate between the isolates. Streptococcus agalactiae was found in eight of 96 herds in which S. agalactiae had never previously been found during the surveillance program. Streptococcus agalactiae was not found in all seven sampling rounds in any of the eight herds. Comparing the approved method with supplemental findings by the other methods, the estimated sensitivity was (95% confidence limits): 0.786 (0.628; 0.892) and the estimated specificity (95% confidence limits): 0.995 (0.985; 0.999). Using all four methods on the same sample could increase the sensitivity, but by comparing the methods individually, there was no significant difference between any of them (P > 0.10). In milk samples from three herds, the ribotype of S. agalactiae was the same as in milk from herds sampled just before; therefore, it could not be ruled out that cross-contamination could occur. Taking into account that S. agalactiae in bulk tank milk reflects the presence of S. agalactiae in at least one udder quarter, this investigation gives further reason to assume that S. agalactiae can be seen sporadically in several herds. A surveillance program based on annual bulk tank milk sample examinations will only detect a limited number of S. agalactiae infected herds. If the overall aim is to identify herds where the infection is established, annual bulk tank milk sample examinations combined with the information of number of colonies of S. agalactiae in the sample will be sufficient.

Animals↗

PubMed2004

FbsA, a fibrinogen-binding protein from Streptococcus agalactiae, mediates platelet aggregation.

The bacterium Streptococcus agalactiae is an etiologic agent in the pathogenesis of endocarditis in humans. FbsA, a fibrinogen-binding protein produced by this pathogen, is considered an important virulence factor. In the present study we provide evidence that S agalactiae clinical isolates bearing FbsA attach to fibrinogen and elicit a fibrinogen-dependent aggregation of platelets. Mutants of S agalactiae lacking the fbsA gene lost the ability to attach to fibrinogen and to aggregate platelets. Plasmid-mediated expression of fbsA restored the capability for fibrinogen binding and platelet aggregation in S agalactiae fbsA mutants, and allowed Lactococcus lactis to interact with fibrinogen and to aggregate human platelets. Moreover, a monoclonal anti-FbsA antibody inhibited bacterial adherence to fibrinogen and S agalactiae-induced platelet aggregation. Platelet aggregation was inhibited by aspirin, prostaglandin E(1,) the peptide RGDS, and the antibody abciximab, demonstrating the specificity of platelet aggregation by S agalactiae and indicating an involvement of integrin glycoprotein IIb/IIIa in the induction of platelet aggregation. Aggregation was also dependent on anti-FbsA IgG and could be inhibited by an antibody against the platelet FcgammaRIIA receptor. These findings indicate that FbsA is a crucial factor in S agalactiae-induced platelet aggregation and may therefore play an important role in S agalactiae-induced endocarditis.

Bacterial Proteins↗

PubMed2005

Simultaneous detection and serotype identification of Streptococcus agalactiae using multiplex PCR and reverse line blot hybridization.

Streptococcus agalactiae (group B streptococcus, GBS) is an important cause of sepsis in neonates and their mothers, and the elderly and immunocompromised patients. Ongoing surveillance to monitor GBS serotype distribution is needed to guide the development and assess the feasibility of GBS conjugate vaccines. The authors previously developed a molecular serotype identification method based on serotype-specific PCR and partial sequencing of cps genes. In this study, a novel 10-primer pair multiplex PCR and reverse line blot (mPCR/RLB) hybridization assay was developed for simultaneous detection and serotype identification of all nine GBS serotypes. For all 316 GBS isolates tested the mPCR/RLB results corresponded with those of conventional serotyping and individual serotype-specific PCR, and the method was more convenient and practical than either alternative.

Base Sequence↗

PubMed2005

Surface proteins of Streptococcus agalactiae and related proteins in other bacterial pathogens.

Streptococcus agalactiae (group B Streptococcus) is the major cause of invasive bacterial disease, including meningitis, in the neonatal period. Although prophylactic measures have contributed to a substantial reduction in the number of infections, development of a vaccine remains an important goal. While much work in this field has focused on the S. agalactiae polysaccharide capsule, which is an important virulence factor that elicits protective immunity, surface proteins have received increasing attention as potential virulence factors and vaccine components. Here, we summarize current knowledge about S. agalactiae surface proteins, with emphasis on proteins that have been characterized immunochemically and/or elicit protective immunity in animal models. These surface proteins have been implicated in interactions with human epithelial cells, binding to extracellular matrix components, and/or evasion of host immunity. Of note, several S. agalactiae surface proteins are related to surface proteins identified in other bacterial pathogens, emphasizing the general interest of the S. agalactiae proteins. Because some S. agalactiae surface proteins elicit protective immunity, they hold promise as components in a vaccine based only on proteins or as carriers in polysaccharide conjugate vaccines.

Amino Acid Sequence↗

PubMed2006

[Streptococcus agalactiae highly resistant to fluoroquinolones].

BACKGROUND: Streptococcus agalactiae remains susceptible to penicillin; nevertheless, an increase in the resistance to other antimicrobial families, such as macrolides and more rarely fluoroquinolones, has been described. METHODS AND RESULTS: From 2003 to 2004, two fluoroquinolone-resistant S. agalactiae strains were detected. The strains presented one mutation in parC (Ser79 --> Phe) and an additional mutation in gyrA (Glu85 --> Ala or Glu85 --> Lys). CONCLUSION: This study describes the first S. agalactiae strains highly resistant to fluoroquinolones in Spain.

Amino Acid Substitution↗

PubMedDate not supplied

Isolation of SagI, a new HaeIII isoschizomer from Streptococcus agalactiae.

A new HaeIII isoschizomer from Streptococcus agalactiae was isolated by a single-step purification method. The highly active restriction endonuclease, SagI, was free of nonspecific nuclease activity and was suitable for use in molecular biology procedures. The rapid isolation procedure may be applicable for the recovery of other restriction endonucleases from bacteria.

Deoxyribonucleases, Type II Site-Specific↗

PubMed1999

Presence of mefA and mefE genes in Streptococcus agalactiae.

Eighteen unrelated clinical isolates of Streptococcus agalactiae with the M phenotype harbored an mef gene. DNA sequencing showed that one of nine strains contained mefA (producing one amino acid substitution), whereas the remaining eight carried mefE (identity, 100%). Restriction analysis of PCR products indicated that the nine other strains also contained mefE.

Bacterial Proteins↗

PubMed2005

Antigenicity of Streptococcus agalactiae extracellular products and vaccine efficacy.

Streptococcus agalactiae is a major bacterial pathogen that is the cause of serious economic losses in many species of freshwater, marine and estuarine fish worldwide. A highly efficacious S. agalactiae vaccine was developed using extracellular products (ECP) and formalin-killed whole cells of S. agalactiae. The vaccine efficacy following storage of S. agalactiae ECP and formalin-killed S. agalactiae cells at 4 degrees C for 1 year was determined. The stored ECP containing S. agalactiae formalin-killed cells failed to prevent morbidity and mortality among the vaccinated fish, and the relative percentage survival was 29. Serum antibody responses of the stored ECP and freshly prepared ECP against soluble whole cell extract of S. agalactiae indicated that significantly less antibody was produced in fish immunized with stored ECP and S. agalactiae cells than in those fish immunized with freshly prepared ECP and S. agalactiae cells at day 31 post-vaccination. Silver staining of sodium dodecyl sulphate-polyacrylamide gels and immunostaining of Western blots with tilapia antiserum to S. agalactiae revealed that predominant 54 and 55 kDa bands were present in the freshly prepared ECP fraction. The 55 kDa band was absent from the stored ECP and new bands below 54 kDa appeared on the Western blot. The results of this study on S. agalactiae ECP provide evidence for a correlation between protection and antibody production to ECP and for the importance of the 55 kDa ECP antigen for vaccine efficacy.

Animals↗