Streptococcus spp. and related bacteria: Their identification and their pathogenic potential for chronic mastitis – A molecular approach

Wyder, Anja Barbara; Boss, Renate; Naskova, J.; Kaufmann, Thomas; Steiner, Adrian; Graber, H.U.

doi:10.1016/j.rvsc.2010.09.006

Cited by 63 publications

(53 citation statements)

References 31 publications

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“…Recently, Lc. lactis has been isolated from diseased fish (Wang et al, 2008;Chen et al, 2012;Pérez et al, 2011), bovine mastitis cases (Wyder et al, 2011;Romero et al, 2011, Plumed-Ferrer et al, 2013, Werner et al, 2014, bird infections (Goyache et al, 2001), and many human clinical infections (Mofredj et al, 2007;Uchida et al, 2011). Isolates from the genus Lactococcus are often misidentified as enterococci or streptococci, and the difficulties in correctly identifying them have probably hindered elucidation of their clinical significance (Goyache et al, 2001).…”

Section: Introductionmentioning

confidence: 99%

Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections

Plumed-Ferrer

Barberio

Franklin‐Guild

et al. 2015

Journal of Dairy Science

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In total, 181 streptococci-like bacteria isolated from intramammary infections (IMI) were submitted by a veterinary clinic to Quality Milk Production Services (QMPS, Cornell University, Ithaca, NY). The isolates were characterized by sequence analysis, and 46 Lactococcus lactis ssp. lactis and 47 Lactococcus garvieae were tested for susceptibility to 17 antibiotics. No resistant strains were found for β-lactam antibiotics widely used in clinical practice (penicillin, ampicillin, and amoxicillin), and all minimum inhibitory concentrations (MIC) were far from the resistance breakpoints. Eight strains had MIC intermediate to cefazolin. The random amplification of polymorphic DNA (RAPD)-PCR fingerprint patterns showed a slightly higher heterogeneity for Lc. lactis ssp. lactis isolates than for Lc. garvieae isolates.

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Section: Introductionmentioning

confidence: 99%

Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections

Plumed-Ferrer

Barberio

Franklin‐Guild

et al. 2015

Journal of Dairy Science

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“…Known as a commensal of the digestive and genitourinary tracts of 10 to 30% of the human population, GBS is also a significant source of disease in immunocompromised adults and in the elderly (4)(5)(6)(7). Apart from causing human infections, GBS is an etiological agent of bovine mastitis and invasive disease in fish (8)(9)(10). First identified in the 1930s as a cause of neonatal mortality, it became a widespread concern in many developed countries in the second half of the 20th century (11)(12)(13).…”

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confidence: 99%

Whole-Genome Comparison Uncovers Genomic Mutations between Group B Streptococci Sampled from Infected Newborns and Their Mothers

Almeida¹,

Villain

Joubrel

et al. 2015

J Bacteriol

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Streptococcus agalactiae (group B Streptococcus or GBS), a commensal of the human gut and genitourinary tract, is a leading cause of neonatal infections, in which vertical transmission from mother to child remains the most frequent route of contamination. Here, we investigated whether the progression of GBS from carriage to disease is associated with genomic adaptation. Whole-genome comparison of 47 GBS samples from 19 mother-child pairs uncovered 21 single nucleotide polymorphisms (SNPs) and seven insertions/deletions. Of the SNPs detected, 16 appear to have been fixed in the population sampled whereas five mutations were found to be polymorphic. In the infant strains, 14 mutations were detected, including two independently fixed variants affecting the covRS locus, which is known to encode a major regulatory system of virulence. A one-nucleotide insertion was also identified in the promoter region of the highly immunogenic surface protein Rib gene. Gene expression analysis after incubation in human blood showed that these mutations influenced the expression of virulence-associated genes. Additional identification of three mutated strains in the mothers' milk raised the possibility of the newborns also being a source of contamination for their mothers. Overall, our work showed that GBS strains in carriage and disease scenarios might undergo adaptive changes following colonization. The types and locations of the mutations found, together with the experimental results showing their phenotypic impact, suggest that those in a context of infection were positively selected during the transition of GBS from commensal to pathogen, contributing to an increased capacity to cause disease. IMPORTANCEGroup B Streptococcus (GBS) is a major pathogen responsible for neonatal infections. Considering that its colonization of healthy adults is mostly asymptomatic, the mechanisms behind its switch from a commensal to an invasive state are largely unknown. In this work, we compared the genomic profile of GBS samples causing infections in newborns with that of the GBS colonizing their mothers. Multiple mutations were detected, namely, within key virulence factors, including the response regulator CovR and surface protein Rib, potentially affecting the pathogenesis of GBS. Their overall impact was supported by differences in the expression of virulence-associated genes in human blood. Our results suggest that during GBS's progression to disease, particular variants are positively selected, contributing to the ability of this bacterium to infect its host. Streptococcus agalactiae, or group B Streptococcus (GBS), is currently regarded as one of the leading causes of neonatal sepsis and meningitis worldwide (1-4). Known as a commensal of the digestive and genitourinary tracts of 10 to 30% of the human population, GBS is also a significant source of disease in immunocompromised adults and in the elderly (4-7). Apart from causing human infections, GBS is an etiological agent of bovine mastitis and invasive disease in fish (8-10). F...

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“…The identities of these isolates were confirmed using Gram staining, oxidase test, catalase test and a serological assay. These same methods have been used for identification of Streptococcus species [33,34,35]. However, these tests are supplemented with molecular assays the isolates are identified at species level [35].…”

Section: Discussionmentioning

confidence: 99%

Antimicrobial Activity of 1,3 Dihydroxy-2-Methylimidazolium Bis (Trifluoromethylsulfonyl) Imde and Selected Antibiotics Against <i>Streptococcus</i> Species Isolated from Groundwater in the Northwest Province, South Africa

Ateba¹,

Morare²,

Ebenso³

2014

JFNR

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In developing countries, access to unsafe water and inadequate sanitation continue to be a danger to human health and untreated groundwater constitutes one of the main sources of drinking water supply. The consumption of untreated contaminated groundwater has frequently been identified as a potential source for the transfer and spread of both antibiotic resistant bacteria strains and waterborne infections among humans. Antibiotics are used for the treatment of bacterial infections and therefore the emergence of drug resistant bacterial strains has huge clinical implications. Faced with the rapid growth of bacterial resistance to a number of commonly used antibiotics, ionic liquids are attracting increasing attention as agents that could serve as antimicrobial agents. The aim of this study was to isolate, identify and determine the antimicrobial activity of an ionic liquid and selected antibiotics against Streptococcus species isolated from groundwater samples. A total of 22 samples were collected from borehole taps in some villages in the Northwest Province and analysed for the presence of streptococci. Gramstaining, catalase test, oxidase test and Prolex Streptococcal Grouping Latex assays were used for bacteria identification. The growth inhibitory effect of the ionic liquid 1,3 dihydroxy-2-methylimidazolium bis (trifluoromethylsulfonyl) imide and selected antibiotics was determined. One hundred and seventy six presumptive isolates were obtained and screened for characters of streptococci and 165 isolates were obtained. All the isolates were Gram positive cocci; a large proportion (92.7%) was oxidase negative and only 51.5% were catalase negative. Based on serotyping, 86.7% of the isolates were positively identified as streptococci. All the isolates from Motlhabeng, Stella and Taung were resistant to penicillin G. Moreover, large proportions (75.0% to 95.8%) of these isolates were resistant to vancomycin. All the isolates except a large proportion of those from Stella (88%) and Taung (83%) were found to be more susceptible (22.5% to 50%) to chloramphenicol. Generally, the growth inhibition zone diameter for 1,3 dihydroxy-2-methylimidazolium bis (trifluoromethylsulfonyl) imide against the isolates ranged from 6 to 9 mm and 9 to 22mm for 1% and 10% solutions respectively. In conclusion multi-drug resistant streptococci were isolated from groundwater intended for human consumption. Isolates were however susceptible to the IL tested and the antimicrobial effect increased with increase in concentration of the IL.

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Streptococcus spp. and related bacteria: Their identification and their pathogenic potential for chronic mastitis – A molecular approach

Cited by 63 publications

References 31 publications

Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections

Antimicrobial susceptibilities and random amplified polymorphic DNA-PCR fingerprint characterization of Lactococcus lactis ssp. lactis and Lactococcus garvieae isolated from bovine intramammary infections

Whole-Genome Comparison Uncovers Genomic Mutations between Group B Streptococci Sampled from Infected Newborns and Their Mothers

Antimicrobial Activity of 1,3 Dihydroxy-2-Methylimidazolium Bis (Trifluoromethylsulfonyl) Imde and Selected Antibiotics Against <i>Streptococcus</i> Species Isolated from Groundwater in the Northwest Province, South Africa

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