High-Level Aminoglycoside and Vancomycin Resistance in Enterococcus spp. Isolated from Hospital Acquired Infections, Ismailia, Egypt

This is the authors' abstract. We don't add key points for this paper.

Background: Multidrug resistant Enterococci (MDR) are important hospital acquired infections (HAIs). Objectives: This study aimed to determine the genetic basis of resistance to aminoglycosides and vancomycin in enterococci strains isolated from hospitalized patients with HAIs. Methodology: The disc diffusion method was used to detect high-level aminoglycoside resistance (HLAR) by using gentamicin (120 𝜇g) and streptomycin (300 𝜇g) discs. Nested PCR was performed for the six-aminoglycoside resistance genes. Vancomycin resistance genes were discovered by conventional PCR. Results: In a total of 100 Enterococcus isolates, aac(6')-Ie-aph(2")-Ia gene was found in 30 strains, 25 of them were E.faecalis and the remaining were E.faecium. aph(3'). The presence of high levels of gentamycin and streptomycin resistance was more common in strains carrying aac(6')-1e-aph(2'')-1a gene. We detected vanA gene in 9 isolates and van C in 15 isolates. vanB was not detected. E.faecium strains containing the vanA gene were shown to be resistant to vancomycin by MIC (MIC > 32 μg/mL), nitrofurantoin, ampicillin and penicillin (P<0.001). Van C was detected in 12 isolates of E.faecalis, 1 isolate of E.facium and 2 isolates of E.durans. E.faecalis carrying vanC gene was more resistant to aminoglycoside than vanC negative E.faecalis.. Conclusion: E. faecalis has been seen to be more widespread than other Enterococcus species in our research. we found that the aac(6')-Ie-aph(2")-Ia and aph(3')-IIIa genes are more frequently found than other genes.