Antibiotic Susceptibility and Antibiotic Resistance Genes in Enterococcus Species Isolated from Feces of Bats

Abstract

Enterococci are Gram positive, catalase negative, facultative anaerobic cocci (single, paired or chained), and are found in intestinal tract of many animals including bats. The present work was aimed at studying the prevalence of Enterococcus species specifically E. faecalis and E. faecium in feces of fruit bats. A total of 95 fecal samples were collected from fruit bats (Pteropus medius) from G11/3 sector of Islamabad, Pakistan. From those 95 samples, 43 Enterococcus isolates were recovered. Further testing showed 11 of the isolates were E. faecalis and 32 were E. faecium. After isolation and confirmation, AST was done for 43 Enterococcal isolates. Among 11 E. faecalis isolates, the drugs for which the sensitivity values were high were nitrofurantoin (100%), pencillin (100%), chloramphenicol (100%) ampicillin (91%), teicoplanin (91%) and fosfomycin (81%) while the drugs to which the resistance values were greater than 50% were quinupristin (55%) and rifampicin (55%). Among the 32 E. faecium isolates, the drugs which were highly effective towards E. faecium were ampicillin (91%), fosfomycin (88%) and vancomycin (84%) while the antibiotics against which high resistance was observed were rifampicin (75%), norfloxacin (34%), Linezolid (34%), quinupristin (28%) and doxycycline (25%). Thus, both Enterococcus species showed highest resistance towards rifampicin and quinupristin. After AST, PCRs were done for antibiotic resistance genes for tetracyclines and quinolones. Among the six tetracycline resistance genes of Enterococci, tetM was found in one isolate of E. faecalis and eight isolates of E. faecium respectively while other tetracycline genes were not detected by PCR in any of the positive isolates. The quinolones resistance genes oqxA qnrA, qnrB, and qnrS were not observed in any of the isolates