Dataset Information

Antibiotic Resistance-Susceptibility Profiles of Enterococcus faecalis and Streptococcus spp. From the Human Vagina, and Genome Analysis of the Genetic Basis of Intrinsic and Acquired Resistances.

ABSTRACT: The spread of antibiotic resistance is a major public health concern worldwide. Commensal bacteria from the human genitourinary tract can act as reservoirs of resistance genes playing a role in their transfer to pathogens. In this study, the minimum inhibitory concentration of 16 antibiotics to 15 isolates from the human vagina, identified as Enterococcus faecalis, Streptococcus anginosus, and Streptococcus salivarius, was determined. Eight isolates were considered resistant to tetracycline, five to clindamycin and quinupristin-dalfopristin, and four to rifampicin. To investigate the presence of antimicrobial resistance genes, PCR analysis was performed in all isolates, and five were subjected to whole-genome sequencing analysis. PCR reactions identified tet(M) in all tetracycline-resistant E. faecalis isolates, while both tet(M) and tet(L) were found in tetracycline-resistant S. anginosus isolates. The tet(M) gene in E. faecalis VA02-2 was carried within an entire copy of the transposon Tn916. In S. anginosus VA01-10AN and VA01-14AN, the tet(M) and tet(L) genes were found contiguous with one another and flanked by genes encoding DNA mobilization and plasmid replication proteins. Amplification and sequencing suggested the lsaA gene to be complete in all E. faecalis isolates resistant to clindamycin and quinupristin-dalfopristin, while the gene contain mutations rendering to a non-functional LsaA in susceptible isolates. These results were subsequently confirmed by genome analysis of clindamycin and quinupristin-dalfopristin resistant and susceptible E. faecalis strains. Although a clinical breakpoint to kanamycin for S. salivarius has yet to be established, S. salivarius VA08-2AN showed an MIC to this antibiotic of 128 ?g mL-1. However, genes involved in kanamycin resistance were not identified. Under the assayed conditions, neither tet(L) nor tet(M) from either E. faecalis or S. anginosus was transferred by conjugation to recipient strains of E. faecalis, Lactococcus lactis, or Lactobacillus plantarum. Nonetheless, the tet(L) gene from S. anginosus VA01-10AN was amplified by PCR, and cloned and expressed in Escherichia coli, to which it provided a resistance of 48-64 ?g mL-1 to tetracycline. Our results expand the knowledge of the antibiotic resistance-susceptibility profiles of vaginal bacteria and provide the genetic basis of their intrinsic and acquired resistance.

SUBMITTER: Sirichoat A

PROVIDER: S-EPMC7333779 | biostudies-literature | 2020

REPOSITORIES: biostudies-literature

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Antibiotic Resistance-Susceptibility Profiles of Enterococcus faecalis and Streptococcus spp. From the Human Vagina, and Genome Analysis of the Genetic Basis of Intrinsic and Acquired Resistances.

Sirichoat Auttawit A Flórez Ana Belén AB Vázquez Lucía L Buppasiri Pranom P Panya Marutpong M Lulitanond Viraphong V Mayo Baltasar B

Frontiers in microbiology 20200626

The spread of antibiotic resistance is a major public health concern worldwide. Commensal bacteria from the human genitourinary tract can act as reservoirs of resistance genes playing a role in their transfer to pathogens. In this study, the minimum inhibitory concentration of 16 antibiotics to 15 isolates from the human vagina, identified as Enterococcus faecalis, Streptococcus anginosus, and Streptococcus salivarius, was determined. Eight isolates were considered resistant ...[more]

PMID: 32695087

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Project description:The food chain is thought to play an important role in the transmission of antibiotic resistances from commensal and beneficial bacteria to pathogens. Streptococcus thermophilus is a lactic acid bacterium of major importance as a starter for the dairy industry. This study reports the minimum inhibitory concentration (MIC) of 16 representative antimicrobial agents to 41 isolates of S. thermophilus derived from raw milk. Strains showing resistance to tetracycline (seven), erythromycin and clindamycin (two), and streptomycin and neomycin (one) were found. PCR amplification identified tet(S) in all the tetracycline-resistant strains, and ermB in the two erythromycin/clindamycin-resistant strains. Hybridisation experiments suggested each resistance gene to be located in the chromosome with a similar genetic organization. Five antibiotic-resistant strains -two resistant to tetracycline (St-2 and St-9), two resistant to erythromycin/clindamycin (St-5 and St-6), and one resistant to streptomycin/neomycin (St-10)- were subjected to genome sequencing and analysis. The tet(S) gene was identified in small contigs of 3.2 and 3.7 kbp in St-2 and St-9, respectively, flanked by truncated copies of insertion sequence (IS) elements. Similarly, ermB in St-6 and St-5 was found in contigs of 1.6 and 28.1 kbp, respectively. Sequence analysis and comparison of the largest contig showed it to contain three segments (21.9, 3.7, and 1.4 kbp long) highly homologous to non-collinear sequences of pRE25 from Enterococcus faecalis. These segments contained the ermB gene, a transference module with an origin of transfer (oriT) plus 15 open reading frames encoding proteins involved in conjugation, and modules for plasmid replication and segregation. Homologous stretches were separated by short, IS-related sequences, resembling the genetic organization of the integrative and conjugative elements (ICEs) found in Streptococcus species. No gene known to provide aminoglycoside resistance was seen in St-10. Four strain-specific amino acid substitutions in the RsmG methyltransferase were scored in this strain; these might be associated to its streptomycin/neomycin resistance. Under yogurt manufacturing and storage conditions, no transfer of either tet(S) or ermB from S. thermophilus to L. delbrueckii was detected. The present results contribute toward characterisation of the antibiotic resistance profiles in S. thermophilus, provide evidence for the genetic basis of acquired resistances and deepen on their transference capability.

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Dataset Information

Antibiotic Resistance-Susceptibility Profiles of Enterococcus faecalis and Streptococcus spp. From the Human Vagina, and Genome Analysis of the Genetic Basis of Intrinsic and Acquired Resistances.

Publications

Antibiotic Resistance-Susceptibility Profiles of <i>Enterococcus faecalis</i> and <i>Streptococcus</i> spp. From the Human Vagina, and Genome Analysis of the Genetic Basis of Intrinsic and Acquired Resistances.

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