Prevalence of high-level gentamicin-resistantEnterococcus faecalisandEnterococcus faeciumin an Iranian hospital.
This study was designed to determine the molecular characteristics and antimicrobial resistance of enterococcal strains isolated from patients admitted to an Iranian Hospital. Enterococcal strains were isolated from the burn patients. All strains were screened for genes encoding resistance to aminoglycoside [aac(6')-Ie-aph(2'')-Ia, aph (3'), ant (4')], resistance to vancomycin (vanA, vanB), resistance to tetracycline (tetK, tetL, tetM, tetO), and resistance to erythromycin (ermA, ermB, ermC) by PCR and multiplex PCR-based methods. Genetic diversity was evaluated via Random Amplified Polymorphic DNA (RAPD)-PCR. All enterococcal isolates showed complete sensitivity to vancomycin with MIC ≤ 0.5μg/ml. Resistance to gentamicin, tetracycline, erythromycin, ciprofloxacin or quinopristin-dalfopristin was detected, whilst more than 96.2% of isolates were high-level gentamicinresistant (HLGR) and multiple drug resistant. The most prevalent aminoglycoside resistance gene was aac(6')-Ie-aph(2'')-Ia, that was found in 96.2% (26/27) of the isolates. The most prevalent tetracycline resistance genes were tetM, found in 85.1% (23/27) followed by tetL and tetO found in 7.4% (2/27) of the isolates. The ermA and ermB genes were detected in 33.3% (9/27) and 44.4% (12/27) of the isolates respectively. RAPD-PCR analysis yielded 17 distinct profiles among 27 investigated isolates. One cluster of isolates shared the same RAPD pattern, while 16 isolates had unique RAPD pattern. Our study showed that during the examination time period one RAPD genotype was the common type and was disseminated among patients in the burn unit. Interestingly, most of these strains had an identical or very similar antibiotic and gene resistance pattern.
Antimicrobial Resistance Research Center, Iran University of Medical Sciences, Tehran, Iran;; Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
M
M
Emaneini
Department of Clinical Sciences, Faculty of Veterinary Medicine, Ferdowsi University of Mashhad. Mashhad, Iran.
B
B
Khoramian
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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F
Jabalameli
Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran.
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R
Beigverdi
Department of Social Medicine, Faculty of Medicine, Ilam University of Medical Sciences, Ilam, Iran.
K
K
Asadollahi
Razi Herbal Medicines Researches Center, Department of Microbiology, School of Medicine, Lorestan University of Medical Sciences, Khoramabad, Iran.
M
M
Taherikalani
Antimicrobial Resistance Research Center, Iran University of Medical Sciences, Tehran, Iran.
A R
AR
Lari
D000900:Anti-Bacterial Agents; D024881:Drug Resistance, Bacterial; D013293:Enterococcus faecalis / Q000187:drug effects / Q000302:isolation & purification*; D016984:Enterococcus faecium / Q000187:drug effects / Q000302:isolation & purification*; D005839:Gentamicins / Q000494:pharmacology*; D016908:Gram-Positive Bacterial Infections / Q000188:drug therapy; D006801:Humans; D007492:Iran; D008826:Microbial Sensitivity Tests; D015995:Prevalence; D019105:Random Amplified Polymorphic DNA Technique
D000900:Anti-Bacterial Agents; D005839:Gentamicins
Enterococcus; HLGR; RAPD-PCR