title: Antibiotic resistance, efflux pump genes and virulence determinants in Enterococcus spp. from surface water systems.
abstract: The aim of this study was to report on antibiotic susceptibility patterns as well as highlight the presence of efflux pump genes and virulence genetic determinants in Enterococcus spp. isolated from South African surface water systems. One hundred and twenty-four Enterococcus isolates consisting of seven species were identified. Antimicrobial susceptibility testing revealed a high percentage of isolates was resistant to β-lactams and vancomycin. Many were also resistant to other antibiotic groups. These isolates were screened by PCR, for the presence of four efflux pump genes (mefA, tetK, tetL and msrC). Efflux genes mefA and tetK were not detected in any of the Enterococcus spp. However, tetL and msrC were detected in 17 % of the Enterococcus spp. The presence of virulence factors in the Enterococcus spp. harbouring efflux pump genes was determined. Virulence determinants were detected in 86 % of the Enterococcus spp. harbouring efflux pump genes. Four (asa1, cylA, gel and hyl) of the five virulence factors were detected. The findings of this study have demonstrated that Enterococcus from South African surface water systems are resistant to multiple antibiotics, some of which are frequently used for therapy. Furthermore, these isolates harbour efflux pump genes coding for resistance to antibiotics and virulence factors which enhance their pathogenic potential.
authors: Unit for Environmental Sciences and Management: Microbiology, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom, 2520, South Africa.
authors: L G
authors: LG
authors: Molale
authors: Unit for Environmental Sciences and Management: Microbiology, North-West University, Potchefstroom Campus, Private Bag X6001, Potchefstroom, 2520, South Africa. carlos.bezuidenhout@nwu.ac.za.
authors: Cornelius Carlos
authors: CC
authors: Bezuidenhout
mesh_terms: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins / Q000235:genetics*; D024881:Drug Resistance, Bacterial; D016983:Enterococcus / Q000187:drug effects* / Q000235:genetics* / Q000502:physiology; D005618:Fresh Water / Q000382:microbiology; D005798:Genes, Bacterial; D013019:South Africa; D014774:Virulence; D037521:Virulence Factors / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D037521:Virulence Factors
keywords: Efflux pump genes; Enterococcus spp.; Multiple antibiotic resistance; Surface water systems; Virulence genes