Isolation, identification and antibiotic susceptibility of various clinical Enterococcus species in Sabah, Malaysia

Abstract

Background: Enterococcus spp. are Gram-positive facultatively anaerobic pathogens causing community-acquired and hospital-acquired infections. Common clinical manifestation are the bloodstream, urinary tract and surgical site infections. The increasing incidence of Enterococcus infections has gained immense public interest recently. The objectives of this study were to isolate, and identify, and antibiotic resistance profiling of Enterococcus spp. from patients in a tertiary hospital in Sabah, Malaysia. Methods and materials: Enterococcus isolates from various clinical specimens from body fluids (blood, urine, pus, high vaginal swab and peritoneal fluid) were collected from July to October 2019. The Enterococcus species, antibiotic susceptibility and resistance profiles were determined using Vitek2 (Biomerieux, Hazelwood, MO, USA) according to manufacturer's instruction. DNA were extracted using the DNeasy tissue kit (Qiagen, Valencia, CA). Identification of Enterococcus species was confirmed by polymerase chain reaction (PCR) using species specific primers. The E. gallinarum and E. raffinosus were also confirmed by 16S DNA sequencing. This research was approved by the Medical Research Ethics Committee (MREC), Ministry of Health, Malaysia (No. NMRR-19-1770-48622). Results: Among the 48 clinical specimens, four different Enterococcus species were identified of which 34 (70.8%) were E. faecalis 12 (25.0%), E. faecium and another 2 (4.2%) were E. gallinarum and E. raffinosus. Majority of the cases were diagnosed as urinary tract or blood stream infections with patient's age ranges from 1 to 87 years old. The antibiotic susceptibility pattern indicates that resistance to ampicillin was 31.3% and ciprofloxacin was 25.0%. One isolate, E. faecalis, showed resistance to both vancomycin and linezolid from a pus sample. Another strain, E. faecalis, from urine showed resistant to linezolid, ciprofloxacin and gentamicin. Conclusion: The occurrence of clinical vancomycin resistance Enterococcus spp. was very low with only one isolate out the total 48 samples examined. It was observed that E. faecium is more resistant to ampicillin (18.8%) than E. faecalis isolates (4.2%). Enhanced surveillance for multidrug resistant organisms (MDRO) and vancomycin resistant Enterococcus (VRE) pathogens could be helpful for effective infection control measures in healthcare facilities.