Multidrug-resistant enterococci in the hospital environment: detection of novel vancomycin-resistant E. faecium clone ST910

Abstract

Introduction: The role of the hospital environment as a reservoir of resistant bacteria in Tunisia has been poorly investigated; however, it could be responsible for the transmission of multidrug-resistant bacteria. The objective was to study the prevalence of Enterococcus in the environment of a Tunisian hospital and the antibiotic resistance phenotype/genotype in recovered isolates, with special reference to vancomycin resistance. Methodology: A total of 300 samples were taken (March-June, 2013) and inoculated in Slanetz-Bartley agar plates supplemented or not supplemented with 8 µg/mL of vancomycin. Antibiotic resistance genes were tested by polymerase chain reaction (PCR). The clonal relatedness of the vanA isolates was assessed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence testing (MLST). Results: Enterococci were recovered in 33.3% of tested samples inoculated in SB medium. E faecium was the most prevalent species, followed by E. faecalis and E. casseliflavus. Antimicrobial resistance genes detected were as follows (number of isolates): erm(B) (71), tet(M) (18), aph(3')-IIIa (27), ant(6)-Ia (15), cat(A) (4), and van(C2) (6). Vancomycin-resistant-enterococci (VRE) were recovered from 14 samples (4.7%), when tested in SB-VAN. The 14 VRE (one per positive sample) were identified as E. faecium and contained the van(A),erm(B), tet(M), ant(6)-Ia, and aph(3')-IIIa genes. Thirteen of the VRE strains were ascribed by PFGE and MLST to a novel clone (new ST910), and only one VRE strain was typed as ST80 included in CC17. Conclusions: The emergence and spread of new clones of VRE, especially in the hospital environment in this country, could become particularly problematic.

Molecular epidemiology and mechanisms of antibiotic resistance inEnterococcusspp.,Staphylococcusspp., andStreptococcusspp. in Africa: a systematic review from a One Health perspective

“…isolated resistant E. faecium ST80 from humans in South Africa, and this clone was reported for the first time by Dziri et al . from environmental samples in a Tunisian hospital and by Elhani et al . also in Tunisia.…”

Molecular Epidemiology and Mechanisms of Antibiotic Resistance in Gram-positive Bacteria in Africa: A Systematic Review and Meta-Analysis from a One Health Perspective

“…Fischer et al (2013) also reported the association between Tn916 and tet(M) in tetracycline-resistant S. agalactiae in camel in Kenya 86 . Similarly, IS 16 was found in vancomycin-resistant E. faecium (ST80, ST180 and ST910) in humans and the environment in Tunisia 69,70 . Investigations into the association between MGEs and resistance genes were limited by few studies (n=22 studies) on MGEs.…”

“…Similarly, Lochan et al (2016) 30 in South Africa, Dziri et al (2016) 20 and Elhani et al (2014) 69 in Tunisia isolated resistant E. faecium ST80 from humans. For the first time, E. faecium ST80 was isolated from environmental samples in a hospital in Tunisia by Elhani et al (2013) 69 and Dziri et al (2016) 70 . Transmission of this resistant clone to animals is possible, although not yet reported.…”

Prevalence and molecular characterization of Enterococcus faecalis from spring water

“…Molecular typing studies of E . faecalis can help to obtain better knowledge of the genetic relatedness within this bacterium and have identified the relative evolutionary of lateral gene transfer among these strains (Dziri et al, ; Zischka et al, ).…”

“…As sequence-based, MLST typing provides stable bacterial isolates, molecular diversity is consistent in laboratories all over the world. Molecular typing studies of E. faecalis can help to obtain better knowledge of the genetic relatedness within this bacterium and have identified the relative evolutionary of lateral gene transfer among these strains (Dziri et al, 2016;Zischka et al, 2015).…”