Detection of Antibiotic Resistance Genes (CTX-M, Van A and Van B) of Enterococcus faecalis Isolated from Children with Bacteremia by RT-PCR

Fever is one of the most common diseases affecting humans, as it results from any disease or development and worsening of the disease for most people with widespread infections in the body. Therefore, this study aimed to evaluate antibiotic resistance genes (CTX-M, Van A and Van B) of Enterococcus faecalis isolated from children with bacteremia by RT-PCR. A total of  ۲۰۰ children was enrolled in the study, ۱۰۰ children with fever and ۱۰۰ healthy children (not suffering from any problem); that is, they are a control group for the detection of antibiotic resistance genes (CTX-M, Van A and Van B) of Enterococcus faecalis by RT-PCR. The age of the two groups ranged from one to five years. Four ml of venous blood sample was collected from each child; the venipuncture area was sterilized first with alcohol at a rate of ۷۰%, followed by medical iodine and then sterilized with alcohol again to avoid contamination with skin flora. The blood samples were cultured on media for isolating bacteria. Then, the resistant isolates of E. faecalis to Vancomycin and cefotaxime antibiotics were taken and kept in special nutrient agar media where the DNA of the bacteria was extracted using (Zymogene Extraction kit, Japan). The detection of the exact genes (CTX-M, Van A and Van B) was done using Real-Time PCR technology according to the protocol mentioned by the company (Sacace biotechnology, Italy). The study presented that ۴۰% of children with fever have positive blood cultures compared with ۵% in the control group, with a significant difference between the two groups (P<۰.۰۰۱). The study found that ۳۲.۵% of bacteremic children were due to S. aureus, ۳۰%, ۵%, and ۴% were due to E. faecalis, E. coli,  P. aeruginosa and Klebsiella spp, respectively, with significant difference (P<۰.۰۱). The study showed that ۹۱.۶۷% of E. faecalis isolates were sensitive to Levofloxacin, ۸۳.۳۳% to Amoxiclav, ۶۶.۶۷% to Erythromycin, ۵۸.۳۳% to Amikacin, ۵۰% to Ampicillin, ۳۳.۳۳% to cefotaxime and Ceftriaxone and ۲۵% toward Vancomycin. From ۹ isolates resistant to Vancomycin, the study presented that ۸۸.۸۹% of them were observed with Van A gene production as detected by real-time PCR (P<۰.۰۰۱). The study also showed that ۷۷.۷۸% were observed with Van B gene production as detected by real-time PCR (P<۰.۰۰۱). The study revealed that all E. faecalis isolates resistant to cefotaxime and Ceftriaxone were characterized by CTX gene production as detected by real-time PCR (P<۰.۰۰۱).

کلیدواژه ها:

Antibiotic resistance ، CTX-M ، Vancomycin ، Enterococcus faecalis RT-PCR