Pheno- and genotypic properties of streptococci of serological group B of canine and feline origin

Yildirim, Ali Önder

doi:10.1016/s0378-1097(02)00719-x

Cited by 10 publications

(14 citation statements)

References 12 publications

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“…Interestingly, we found that 8 of the 52 human isolates and none of the 52 bovine isolates characterized in our study carried an IS1548 insertion in hylB, which was associated with a hyaluronidase-negative phenotype. Our findings are consistent with previous studies that showed the presence of the IS1548 insertion in hylB in S. agalactiae isolates from human endocarditis and septicemia patients and from human asymptomatic carriers (15) as well as in human and feline isolates collected in Europe (49). These data further support the idea that hyaluronidase may not be required for the ability of S. agalactiae to cause certain infections (e.g., endocarditis) in human hosts.…”

Section: Discussionsupporting

confidence: 93%

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Sukhnanand¹,

Dogan²,

Ayodele³

et al. 2005

J Clin Microbiol

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Streptococcus agalactiae causes severe invasive disease in humans and mastitis in cattle. Temporally matched bovine milk isolates and clinical human invasive isolates (52 each) collected in New York State over 18 months were characterized by molecular subtyping and phenotypic methods to probe the interspecies transmission potential of this species. EcoRI ribotyping differentiated 17 ribotypes, and DNA sequencing of the housekeeping gene sodA and the putative virulence gene hylB differentiated 7 and 17 allelic types, respectively. Human and bovine isolates were not randomly distributed between ribotypes or hylB and sodA clusters. The combined analysis of all subtyping data allowed the differentiation of 39 clonal groups; 26 groups contained only bovine isolates, and 2 groups contained both human and bovine isolates. The EcoRI ribotype diversity among bovine isolates (Simpson's numerical index of discrimination [mean ؎ standard deviation], 0.90 ؎ 0.05) being significantly higher than that among human isolates (0.42 ؎ 0.15) further supports that these isolates represent distinct populations. Eight human isolates, but no bovine isolates, showed an IS1548 transposon insertion in hylB, which encodes a hyaluronidase. Based on data for 43 representative isolates, human isolates, on average, showed lower hyaluronidase activities than bovine isolates. Isolates with the IS1548 insertion in hylB showed no hyaluronidase activity. Human and bovine isolates did not differ in their abilities to invade HeLa human epithelial cells. Our data show that (i) EcoRI ribotyping, combined with hylB and sodA sequencing, provides a discriminatory subtype analysis of S. agalactiae; (ii) most human invasive and bovine S. agalactiae isolates represent distinct subtypes, suggesting limited interspecies transmission; and (iii) hyaluronidase activity is not required for all human infections.

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Section: Discussionsupporting

confidence: 93%

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Sukhnanand¹,

Dogan²,

Ayodele³

et al. 2005

J Clin Microbiol

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“…From farms C and D 14 and eight bacteria, respectively, were additionally isolated 8 months later. The isolates were identified and further characterized by cultural and biochemical properties, by detection of hemolysis [6], pigmentation in GBS Islam agar (Oxoid, Wesel, Germany) supplemented with 5% sterile horse serum, by serogrouping and by determination of type‐specific polysaccharide (Ia, Ib, II, III, IV, V, VI, VII, VIII) and protein (X, R, Rib, cα, cβ) antigens [7], supported by polymerase chain reaction (PCR) amplification of the gene rib encoding protein Rib [8] and the gene bag corresponding to protein cβ[9]. The identification of the bacteria was also conducted by PCR amplification of species‐specific parts of the gene encoding the 16S rRNA, the 16S–23S rDNA intergenic spacer region and the CAMP factor gene cfb with oligonucleotide primers and thermal cycler programs described previously [10,11].…”

Section: Methodsmentioning

confidence: 99%

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Merl¹,

Abdulmawjood²,

Lämmler³

et al. 2003

FEMS Microbiology Letters

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In the present study 79 streptococcal cultures isolated from subclinical mastitis of 54 cows from seven dairy farms (A^G) in Hesse, Germany, were comparatively investigated using conventional and molecular methods. The isolates could be identified as Streptococcus agalactiae, belonging to Lancefield's serological group B by determination of cultural, biochemical and serological properties and by polymerase chain reaction (PCR)-mediated amplification of species-specific parts of the 16S ribosomal DNA, the 16S^23S rDNA intergenic spacer region and the CAMP factor gene cfb. The investigated group B streptococci were further characterized serologically for specific polysaccharide and protein antigens. Serotyping the isolates revealed a predominance of surface protein antigen X, either alone or in combination with polysaccharide antigen Ia. This could be observed for 39 isolates of farms A, B and C. Six group B streptococci from farm E displayed the serotype pattern III/Rib, two isolates from farm G showed the serotype pattern Ib/cK. The remaining cultures from farms D and F (n = 32) were non-typable. The occurrence of protein Rib could be confirmed by PCR amplification of the gene rib. The two isolates with serotype pattern Ib/cK also reacted positively for the cL-encoding gene bag. Additional properties which allowed a phenotypic characterization of the S. agalactiae were the degree of pigmentation, growth properties in fluid media and soft agar, the surface hydrophobicity, the ability to hemagglutinate rabbit erythrocytes and their resistance reactions to tetracycline and minocycline. The isolates of the seven farms showed identical or almost identical characteristics. The 79 group B streptococci were additionally investigated by macrorestriction analysis of their chromosomal DNA using the restriction endonucleases SmaI, ApaI and SalI. The restriction patterns obtained by pulsed-field gel electrophoresis displayed identical or closely related patterns for the cultures of the various farms. The pheno-and genotypic characteristics of the 79 group B streptococci of the present study revealed that a single S. agalactiae strain or at least closely related subtypes of this strain were responsible for the mastitis situation of the seven farms.

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“…In general, is possible that the success of both the CC-17 and CC-61 lineages in separate hosts can be attributed to subsequent and independent divergence. This hypothesis is supported by evidence demonstrating that GBS strains from humans and bovines represent distinct populations (2, 9, 19, 52,) and vary in the distribution of putative virulence genes (e.g., scpB [16,17,20,58]). Moreover, ST-17, a member of CC-17 that is associated with neonatal disease (3,29,37,38,43) and meningitis (43), was found to have evolved from a bovine ancestor (2).…”

mentioning

confidence: 87%

Selection, Recombination, and Virulence Gene Diversity among Group B Streptococcal Genotypes

Springman

Lacher²,

et al. 2009

J Bacteriol

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Transmission of group B Streptococcus (GBS) from mothers to neonates during childbirth is a leading cause of neonatal sepsis and meningitis. Although subtyping tools have identified specific GBS phylogenetic lineages that are important in neonatal disease, little is known about the genetic diversity of these lineages or the roles that recombination and selection play in the generation of emergent genotypes. Here, we examined genetic variation, selection, and recombination in seven multilocus sequence typing (MLST) loci from 94 invasive, colonizing, and bovine strains representing 38 GBS sequence types and performed DNA sequencing and PCR-based restriction fragment length polymorphism analysis of several putative virulence genes to identify gene content differences between genotypes. Despite the low level of diversity in the MLST loci, a neighbor net analysis revealed a variable range of genetic exchange among the seven clonal complexes (CCs) identified, suggesting that recombination is partly responsible for the diversity observed between genotypes. Recombination is also important for several virulence genes, as some gene alleles had evidence for lateral gene exchange across divergent genotypes. The CC-17 lineage, which is associated with neonatal disease, is relatively homogeneous and therefore appears to have diverged independently with an exclusive set of virulence characteristics. These data suggest that different GBS genetic backgrounds have distinct virulence gene profiles that may be important for disease pathogenesis. Such profiles could be used as markers for the rapid detection of strains with an increased propensity to cause neonatal disease and may be considered useful vaccine targets.Group B Streptococcus (GBS) is a leading cause of neonatal sepsis, pneumonia, and meningitis (51) and causes infections in pregnant women, nonpregnant adults, and the elderly with underlying medical conditions. Maternal GBS colonization is a main risk factor for neonatal disease, and roughly 20 to 40% of pregnant women are colonized (14, 23). Colonization rates of up to 31% and 34% have been documented in young men (4) and nonpregnant women (4, 42), respectively, whereas a rate of 22% has been observed in individuals over 65 years of age (18). GBS has also been identified as the cause of bovine mastitis in up to 45% of symptomatic bovines (30). Nine distinct polysaccharide capsule types (serotypes) are known, and the serotype distribution varies by population.The genetic diversity of GBS populations has been studied using a variety of different methods, including restriction fragment length polymorphism (RFLP) (24), ribotyping (5, 25), pulsed-field gel electrophoresis (49), multilocus enzyme electrophoresis (MLEE) (45), random amplification of polymorphic DNA (36), restriction digestion pattern (RDP) typing (53), and multilocus sequence typing (MLST) (28). By utilizing methods that focus on conserved genetic changes within GBS strains, virulent GBS clones that have diversified genetically can be identified. Both MLEE an...

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Pheno- and genotypic properties of streptococci of serological group B of canine and feline origin

Cited by 10 publications

References 12 publications

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Molecular Subtyping and Characterization of Bovine and Human Streptococcus agalactiae Isolates

Determination of epidemiological relationships ofStreptococcus agalactiaeisolated from bovine mastitis

Selection, Recombination, and Virulence Gene Diversity among Group B Streptococcal Genotypes

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