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Evaluation of a rapid latex test for direct detection of Streptococcus agalactiae in various obstetrical and gynaecological disorders.

Cervical samples collected during speculum examination in 413 women were tested for the presence of Streptococcus agalactiae by Gram staining, a new latex agglutination test and standard cultures. The results of each method are reported in correlation with the clinical circumstances of isolation. Gram stain and the latex agglutination test had a sensitivity of 30% and 78%, and a specificity of 89% and 98% respectively compared with culture. The sensitivity of the latex agglutination test was higher in cases of premature rupture of membranes (90%), presumed chorioamnionitis (86%), presumed post-partum endometritis (86%) and presumed salpingitis (87%). This latex agglutination test appears to be useful for identifying patients who are heavily colonized with Streptococcus agalactiae and are at a high risk of infection.

Evaluation Studies as Topic↗

Group B streptococcus arthritis.

Serious infections with group B streptococcus (streptococcus agalactiae) are rare in adults. A 81-year-old patient with cirrhosis who developed a septic arthritis due to this germ, is described. Only eleven cases of group B streptococcal arthritis have been previously reported.

Aged↗

Morphological and immunological characteristics of Streptococcus pyogenes, group A, type 50.

Streptococcus pyogenes, group A, type 50, in contrast to other group A streptococci, causes spontaneous disease in mice thereby providing a suitable experimental model for the study of human streptococcosis. Type 50 possesses various peculiar morphological and immunobiological characteristics and under certain conditions forms and extremely thick non-antigenic capsule which seems to interfere with the binding of antibody. This interference is most likely responsible for the difficulties in detecting type 50 streptococci in the tissues of infected mice by immunofluorescent staining. Whereas the surface components (hyaluronic acid, M-antigen) of the type 50 Streptococcus exhibit several uncommon features, the more deeply located cell wall antigens, like peptidoglycan and C-carbohydrate, do not differ in either their chemical constituents or their serological reactions from the comparable components of other group A streptococci.

Animals↗

Streptococcus group B isolates in a regional hospital area.

A survey of the frequency of group B streptococcal infections in the Sharon area (Israel) was done in this laboratory. In the female genital tract streptococcus group B was found in 11.8%. This microorganism was recovered in lower frequencies (1.6%-7.4%) in other infection sites (CSF, wounds, throat, blood, and urine). The streptococci were identified as belonging to group B by biochemical properties such as resistance to bacitracin and capability to hydrolyze hippurate. Later the isolates were classified serologically. Serotypes Ib, Ic, and II were predominant in the vaginal smears (25%-28% each serotype). In the other infection sites serotype Ib was the most frequent (36%). The isolates were sensitive to penicillin, cloxacillin, cephalothin, and erythromycin - M.I.C. 0.1-0.2 microgram/ml. Most of the isolates were resistant to tetracycline (69%) and some to chloramphenicol (17.5%). Synergism has been obtained in vitro using a combination of gentamicin and penicillin simultaneously. Group B streptococci or Streptococcus agalactiae first became known because of association with bovine mastitis. This microorganism is now widely appreciated as a potent human pathogen. In several geographic regions it is the leading cause of meningitis during the first two months of life (Eickhoff et al. 1965; Franciosi et al. 1973; Baker et al. 1973; Patterson and Hafeez 1976; Anthony and Okada 1977; Baker 1977). Two clinical syndromes have been defined among infants. The first syndrome, called early onset, is observed in neonates aged five days or less (Baker et al. 1973). In older infants (between 10 days and three months of age) the second syndrome or the late-onset may appear (Franciosi et al. 1973; Baker et al. 1973). In the last few years infections in adults have also been reviewed (Bayer et al. 1976; Lerner et al. 1977). Group B streptococci are divided into five serological types: Ia, Ib, Ic, II, and III (Wilkinson and Eagon 1971); some strains to be devoid of type-specific antigens and are called nontypable (NT). The serotypes of group B streptococci isolated from infants with early onset disease are identical with those isolated from the genital tracts of their mothers. Infants probably acquire the microorganism during passage through the birth canal (Baker and Barrett 1973). Furthermore, the genitourinary tract is known to be a major reservoir of infection and a source for subsequent dissemination in both men and women (Wilkinson 1978). The appearance of sepsis and meningitis in neonates caused by group B streptococci and which was reported previously by this laboratory (Maayan et al. 1978; Nitzan et al. 1978) has prompted us to study the current situation of the infections caused by this microorganism. This study presents a survey on the frequency of infections, serotype distribution, and susceptibility to antimicrobial agents of group B streptococcal isolates in the Sharon district (Israel). It seems that the transformation of the group B streptococci to human pathogens has also affected this area.

Anti-Bacterial Agents↗

Comparison of E-test with agar dilution for determining susceptibility of Streptococcus pneumoniae to penicillin.

Minimum inhibitory concentrations (MICs) of penicillin for Streptococcus pneumoniae were determined by the E-test and the agar dilution method. Ninety Streptococcus pneumoniae strains were tested, of which 16 were resistant, 33 intermediate, and 41 susceptible by agar dilution. By the E-test, 80 (88.9%) strains agreed with these determinations within one log2 dilution step, and no strains disagreed by more than two dilution steps. Sixty-eight of the 70 strains with discrepant MICs read lower in the E-test, resulting in 15 strains being placed in different susceptibility categories when classified by this test. Exact MICs rather than classification groups should be used to determine appropriate antibiotic therapy, since small differences in MICs determined by different methods can lead to a significant degree of misclassification.

Colony Count, Microbial↗

Effects of enterocin E1A on the ultrastructure of Streptococcus faecium.

Streptococcus faecium 158 cells were examined by electron microscopy at sequential intervals after addition of enterocin E1A, a bacteriocin produced by Streptococcus faecium E1. After addition of enterocin E1A, the nuclear material began to concentrate into distinct areas at the center of the bacteria. In a later stage, extensive condensation of the nuclear filaments left a small cluster of dense granules within a cytoplasmic vacuole, and 10-20% of the cells underwent a complete lysis.

Enterobactin↗

Monoclonal antibodies against the common polysaccharide of Streptococcus agalactiae.

A monoclonal antibody giving a dominant reaction with the group-specific polysaccharide of streptococcus group B in an ELISA test has been developed. The purified polysaccharide exhibited a high positivity with reference anti B streptococcal antiserum in the ELISA test. Cross-tests of antibodies with other groups of streptococci provided a minimum cross-reaction only in the case of G streptococci. Monoclonal antibodies were prepared using Streptococcus agalactiae S 589 MT strain isolated from a case of bovine mastitis which does not express Ia, Ib, II, III, IV and V type antigens, nor C, R and X protein antigens.

Animals↗

Distribution of plasmid-borne stress protein genes in Streptococcus thermophilus and other lactic acid bacteria.

The presence of heat stress protein genes (hsp) was tested by Southern hybridization analysis in total DNA extracts from species of the genus Streptococcus (47 strains), Lactobacillus (34 strains), Lactococcus (24 strains), and Leuconostoc (5 strains). The biotinylated hsp16.4 probe prepared from an ORF2 fragment of pER341 (2.8 kb) tested positively with restricted DNA extracts of seven Streptococcus thermophilus strains and a single strain of Lactococcus lactis subsp. cremoris. In all positive S. thermophilus strains, the hsp was located on plasmids ranging from ca. 2.8 kb to 11 kb in size, while hsp was present in a 7.5-kb plasmid in Lactococcus lactis subsp. cremoris. Southern blots with a rep probe showed that all hsp16.4+ plasmids in S. thermophilus strains also shared homology with the replication function (rep) of pER341, suggesting the common origin of these plasmids.

Bacterial Proteins↗

Cloning, sequencing, and chromosomal location of a putative class-II aldolase gene from Streptococcus pneumoniae.

The nucleotide sequence of a 1620-bp chromosomal fragment from Streptococcus pneumoniae, containing a putative class-II aldolase gene, has been determined. The N-terminal amino acid (aa) sequence of S. pneumoniae class-II aldolase protein allowed us to determine the initiation site for the putative aldolase gene, and a molecular weight of 31,274 Da was predicted for the protein, after removal of the N-terminal methionine. Northern hybridization and primer extension analysis showed a 1100-nucleotide transcript with a transcription start site located 43 or 42 bp upstream of the start codon. Southern hybridization studies indicated that the putative class-II aldolase gene was in the ApaI fragment 6, SmaI fragment 9, and SacII fragment 12 or 13 of the physical map of S. pneumoniae chromosome. Southern hybridization analysis and partial sequencing performed in another eight streptococcus species, belonging to six different phylogenetic groups, suggested that a class-II aldolase gene with a considerable DNA homology to that of the S. pneumoniae, could exist in these streptococcal species.

Amino Acid Sequence↗

Pheromone-induced expression of recombinant proteins in Streptococcus thermophilus.

A locus encoding proteins with high homology to the pneumococcal BlpABCHR quorum-sensing system was identified in Streptococcus thermophilus LMG 18311. The BlpABCHR system regulates bacteriocin production in Streptococcus pneumoniae by monitoring the extracellular concentration of a peptide-pheromone encoded by blpC. The homologous system in S. thermophilus, termed StbABCHR, contains a corresponding gene (stbC) encoding a possible peptide-pheromone (STP) that presumably controls bacteriocin production in S. thermophilus. We synthesized this peptide and found that it activates transcription of a gusA reporter gene placed behind the promoter of the bacteriocin-like gene stbD. Furthermore, deletion mapping and mutational analysis of the stbD promoter region were used to identify a degenerated direct repeat motif required for STP induced GusA expression. Our findings provide strong evidence that STP regulates bacteriocin production in S. thermophilus LMG 18311, and show that the StbABCHR quorum-sensing system can be exploited for inducible expression of recombinant proteins in this bacterial species.

Bacteriocins↗

Therapeutic effect of llama derived VHH fragments against Streptococcus mutans on the development of dental caries.

Streptococcus mutans is the main cause of dental caries. We evaluated the therapeutic effect of variable regions of a llama heavy chain antibody fragments directed against S. mutans named S36-VHH (S for Streptococcus) alone or fused with glucose oxidase (GOx) from Aspergillus niger. Western blot analysis and ELISA revealed binding of the S36-VHH to the streptococcal antigen I/II adhesin molecule of S. mutans serotype C. In a rat-desalivated caries model, daily administration of S36-VHH significantly reduced the development of smooth surface caries. No additional therapeutic effect of GOx was observed. Our results suggest that llama VHH antibodies may be a potential benefit as prophylaxis against dental caries.

Animals↗

Survey of phenotypic and genetic features of streptococcus pyogenes strains isolated in Northwest Italy.

Streptococcus pyogenes (group A Streptococcus [GAS]) is an important pathogen whose virulence is related to the production of exotoxins and the presence of particular surface components. One hundred eighty-two GAS strains were collected in northwestern Italy between 1994 and 2002 and analyzed for phenotypic characteristics (opacity factor, proteolyic activity, and antimicrobial susceptibility) and by polymerase chain reaction for the presence of genes responsible for the production of exotoxins implicated in pathogenesis speA and speF and of prtF(1) (encoding fibronectin-binding protein F1). All strains were speF positive and 19.2% were speA positive and prtF(1) negative, whereas the prtF(1) gene was identified in 39.5% of the other strains. Of these, approximately half revealed the same pulse-field gel electrophoresis (PFGE) pattern but differed in both speA gene and macrolide resistance.

Adhesins, Bacterial↗

Gene knockout of the intracellular amylase gene by homologous recombination in Streptococcus bovis.

Streptococcus bovis expresses two different amylases, one intracellular and the other secreted. A suicide vector containing part of the intracellular alpha-amylase gene from Streptococcus bovis WI-1 was recombined into the S. bovis WI-1 chromosome to disrupt the endogenous gene. Recombination was demonstrated by Southern blot, and zymogram analysis confirmed the loss of the intracellular amylase. Amylase activity in cell-free extracts of the recombinant grown in the presence of 1% starch was only 7% of wild type. The rate of logarithmic growth of the recombinant was 15-20% of the wild type in medium containing either 1% glucose, starch, or cellobiose. Revertants and non-amylase control recombinants had logarithmic growth rates that were the same as wild type. Plasmid transformants containing multiple copies of the cloned gene expressed up to threefold higher levels of intracellular amylase activity than wild type but did not demonstrate elevated growth rates. These results suggest that a critical level of expression of the intracellular amylase gene may be important for rapid growth of the bacterium.

Amylases↗

Cloning and expression of the pediocin operon in Streptococcus thermophilus and other lactic fermentation bacteria.

Production of pediocin in Pediococcus acidilactici is associated with pMBR1.0, which encodes prepediocin, a pediocin immunity protein, and two proteins involved in secretion and precursor processing. These four genes are organized as an operon under control of a single promoter. We have constructed shuttle vectors that contain all four structural genes, the chromosomal promoter ST(P2201) from Streptococcus thermophilus, and repA from the 2-kbp S. thermophilus plasmid pER8. The recombinant plasmid, pPC318, expressed and secreted active pediocin in Escherichia coli. Streptococcus thermophilus, Lactococcus lactis subsp. lactis, and Enterococcus faecalis were electrotransformed with pPC418, a modified vector fitted with an erythromycin resistance tracking gene. Pediocin was produced and secreted in each of the lactic acid bacteria, and production was stable for up to ten passages. The expression of pediocin in dairy fermentation microbes has important implications for bacteriocins as food preservatives in dairy products.

Bacteriocins↗

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↗

Streptococcus pyogenes meningitis: report of a case and review of the literature.

UNLABELLED: Streptococcus pyogenes is a very uncommon cause of bacterial meningitis beyond the neonatal period. A case report and a review of the recent literature is presented. We report on a previously healthy 7-year-old boy who developed S. pyogenes meningitis following a 2-day history of otitis media. A CT scan revealed right-sided mastoiditis as a possible focus of infection. The patient was treated with penicillin G for 14 days. The clinical course was uneventful, and the recovered without sequelae. By means of the polymerase chain reaction, the presence of streptococcal pyrogenic exotoxin (SPE) B and SPE C, but not SPE A genes was discovered from the bacterial DNA. CONCLUSION: Streptococcus pyogenes is a rare cause of bacterial meningitis but has to be considered as the causative pathogen beyond the neonatal period.

Bacterial Proteins↗

Risk factors for penicillin resistance and mortality in Korean adults with Streptococcus pneumoniae bacteremia.

A retrospective analysis was performed to measure the incidence of pneumococcal bacteremia and to identify risk factors for penicillin resistance and prognostic factors for outcome in adults. A total of 151 cases of pneumococcal bacteremia were identified from 149 adults during the period 1996-2000. The overall rate of penicillin resistance was 49%, ranging from 54.2% in 1996 to 48.5% in 2000 (P=0.93). Rates of resistance to ceftriaxone, clindamycin, erythromycin, and trimethoprim-sulfamethoxazole were 21.6%, 51%, 62%, and 44.7%, respectively. Multidrug resistance was documented in 47.7% of the cases. Penicillin resistance was significantly associated with solid tumor, biliary drainage catheter, and previous beta-lactam therapy in the univariate analysis. However, the associations were not as significant as independent risk factors in the multivariate analysis. Mortality was 23.8% and did not change significantly during the study period (P=0.06). Mortality rates in cases caused by penicillin-susceptible Streptococcus pneumoniae and penicillin-resistant Streptococcus pneumoniae were 23% and 24.7%, respectively (P=0.81). Mortality was not significantly influenced by penicillin resistance, even high-level resistance (24.4% vs. 20%; P=0.64). Multivariate analysis revealed that antineoplastic chemotherapy, respiratory failure, and acute renal failure were independent prognostic factors for mortality. In conclusion, the rate of penicillin resistance among pneumococcal blood isolates was high in the late 1990s, but penicillin resistance, and even high-level penicillin resistance, was not significantly associated with increased mortality in adults with pneumococcal bacteremia.

Adolescent↗

Streptococcus pneumoniae-infected aneurysm extending from a persistent lobar pneumonia: case report and review of the literature.

Presented here is the case of a 63-year-old patient with a Streptococcus pneumoniae-infected aneurysm extending from a persistent lobar pneumonia of the left lung into the thoracic aorta. The patient was successfully treated with surgery and high-dose penicillin, and he remained well at 6-month follow-up. A review of the English-language literature over the past 25 years revealed 22 cases of mycotic or infected aortic aneurysms due to Streptococcus pneumoniae; however, none of these cases resulted in a positive outcome for the patient. The characteristics of these cases are discussed.

Aged↗