Distribution of virulence genes among Enterococcus spp. strains isolated from recreational water samples in Mosul city and evidence for horizontal gene transfer of antibiotic resistance genes
Reyam H Abd Alrazzaq, Rayan M Faisal
Ten water samples were collected from different recreation sites in Tigris river and some swimming pools in Mosul city. The isolation percentage of Enterococcus spp. was 30% using Hicrome Enterococcus faecium agar for initial isolation and 16S rRNA gene sequencing for final identification. The aim of this study was to determine the incidence of eight virulence genes (gelE, efaAfs, ace, esp, cyl, asa1, eep, and agg) in Enterococcusspp. and study the possibility of gene transfer for virulence and antibiotic resistance genes between pathogenic enterococci and those isolated from recreation sites via horizontal gene transfer. Our results detected the presence of virulence genes in 0.0 - 66.7% of environmental isolates and in 66.7- 100% of pathogenic isolates. The virulence genes detected in environmental enterococci were gelE (66.6%), ace (66.6%), efaAfs (66.6%) and agg (33.3%). Even though the percentages for virulence gene detected in environmental enterococci were lower to what was found in pathogenic enterococci, such results show the existence of virulence genes in environmental enterococci that may lead to serious health issues. Enterococcus isolates from water were tested for their ability to resist 8 antibiotics and results showed that they were 100% resistant to gentamycin, 66.6% resistant to streptomycin, ciprofloxacin and kanamycin, and 33.3% resistant to ampicillin, tetracycline, and chloramphenicol, while none of the isolates were resistant to vancomycin. Conjugation experiments showed the possibility of antibiotic resistance genes to transfer between pathogenic enterococci but not to our environmentally isolated enterococci. However, identifying self-transmissible plasmids in Enterococcus may still lead to the spread of antibiotic resistance genes to other compatible recipient enterococci in nature.
Reyam H Abd Alrazzaq, Rayan M Faisal. Distribution of virulence genes among Enterococcus spp. strains isolated from recreational water samples in Mosul city and evidence for horizontal gene transfer of antibiotic resistance genes. International Journal of Biotechnology and Microbiology, Volume 4, Issue 1, 2022, Pages 31-38