Molecular Identification of Some Antibiotic-Resistance Genes and Antibiotic Susceptibility Profile of Enterococcus faecalis Isolated from Clinical Samples

Abstract

Enterococcus spp. are a commensal bacteria and opportunistic pathogens that seriously threaten public health. Enterococcus faecalis and Enterococcus faecium are responsible for about 90% of the enterococcal infections. The ability of E. faecalis to resist many of the utilized antibiotics, which makes the treatment hard, together with its ability to form a biofilm that allows it to cause severe infections, make these bacteria a threat to public health. The study aimed to identify the resistance patterns and species distribution of E. faecalis strains isolated from clinical samples. Conventional methods were used to identify 52 E. faecalis isolates from patients at Al-Imam al-Sadiq teaching hospital in HIilla / Iraq, and a species-specific PCR assay was used for molecular identification for confirmation. The Kirby Bauer test was used to test antibiotic susceptibility to 15 antibiotics and analyze the distribution of two different resistance genes among the isolates (bla-TEM and GyrA). Statistical analysis showed significant differences (P<0.0001) for the antibiotic type and the response's nature. Among E. faecalis, the most prevalent was resistance to oxacillin, penicillin, erythromycin, Rifampicin, clindamycin, and Vancomycin, with a 100% ratio. While the percentage of the resistant isolates to the other antibiotics sorted in descending order was ceftazidime (85%), ampicillin (84.6%), amoxicillin-clavulanic acid (61%), Ciprofloxacin (23%), co-trimoxazole (13.46%), Gentamicin (7.69%), and Chloramphenicol (7.69%). PCR results detected the presence of the gyrA gene in 57.6% (30/52) of the isolates, while the bla TEM appeared in 78.8% of them )41/52(. According to the current study, E. faecalis was found to be resistant to a number of antibiotics and to have genes that resist antibiotics, such as bla-TEM and gyrA.