AUTHOR=Osman Kamelia M. , Ali Mohamed N. , Radwan Ismail , ElHofy Fatma , Abed Ahmed H. , Orabi Ahmed , Fawzy Nehal M. 

TITLE=Dispersion of the Vancomycin Resistance Genes vanA and vanC of Enterococcus Isolated from Nile Tilapia on Retail Sale: A Public Health Hazard

JOURNAL=Frontiers in Microbiology

VOLUME=7

YEAR=2016

URL=https://www.frontiersin.org/journals/microbiology/articles/10.3389/fmicb.2016.01354

DOI=10.3389/fmicb.2016.01354

ISSN=1664-302X

ABSTRACT=<p>Although normally regarded harmless commensals, enterococci may cause a range of different infections in humans, including urinary tract infections, sepsis, and endocarditis. The acquisition of vancomycin resistance by enterococci (VRE) has seriously affected the treatment and infection control of these organisms. VRE are frequently resistant to all antibiotics that are effective treatment for vancomycin-susceptible enterococci, which leaves clinicians treating VRE infections with limited therapeutic options. With VRE emerging as a global threat to public health, we aimed to isolate, identify enterococci species from tilapia and their resistance to <italic>van</italic>-mediated glycopeptide (<italic>van</italic>A and <italic>van</italic>C) as well as the presence of enterococcal surface protein (<italic>esp</italic>) using conventional and molecular methods. The cultural, biochemical (Vitek 2 system) and polymerase chain reaction results revealed eight <italic>Enterococcus</italic> isolates from the 80 fish samples (10%) to be further identified as <italic>E. faecalis</italic> (6/8, 75%) and <italic>E gallinarum</italic> (2/8, 25%). Intraperitoneal injection of healthy Nile tilapia with the eight <italic>Enterococcus</italic> isolates caused significant morbidity (70%) within 3 days and 100% mortality at 6 days post-injection with general signs of septicemia. All of the eight <italic>Enterococcus</italic> isolates were found to be resistant to tetracycline. The 6/6 <italic>E. faecalis</italic> isolates were susceptible for penicillin, nitrofurantoin, gentamicin, and streptomycin. On the other hand 5/6 were susceptible for ampicillin, vancomycin, chloramphenicol, and ciprofloxacin. The two isolates of <italic>E. gallinarum</italic> were sensitive to rifampicin and ciprofloxacin and resistant to vancomycin, chloramphenicol, and erythromycin. Molecular characterization proved that they all presented the prototypic <italic>van</italic>C element. On the whole, one of the two vancomycin resistance gene was present in 3/8 of the enterococci isolates, while the <italic>esp</italic> virulence gene was present in 1/8 of the enterococci isolates. The results in this study emphasize the potential role that aquatic environments are correlated to proximity to anthropogenic activities in determining the antimicrobial resistance patterns of <italic>Enterococcus</italic> spp. recovered from fish in the river Nile in Giza, Elmounib, Egypt as a continuation of our larger study on the reservoirs of antibiotic resistance in the environment.</p>