P32 Occurrence of bla  (KPC), bla  (NDM) and bla  (OXA-48) genes among carbapenemase-producing Enterobacteriaceae (CRE) in National Cancer Institute, Sri Lanka

BACKGROUND: Carbapenemase-producing Enterobacteriaceae (CRE) are a global problem and prevalence of CR genes differs across geographical regions. The current Sri Lankan situation is unknown; hence, this study aimed to identify three commonly occurring CR genes in the region. METHODS: Enterobacteriaceae isolates resistant to carbapenems were collected from clinical samples submitted for routine testing to the microbiology laboratory of National Cancer Institute. Species identification was done using conventional biochemicals and CLSI disc diffusion method was used for ABST of CRE isolates. Identification of CR genes was done by in-house conventional multiplex PCR, using previously described primers (Table 1). Ten microlitres of total DNA from each sample, extracted by heat shock method, was subjected to multiplex PCR in a 50 μL of PCR mixture which contained 5× PCR buffer (10 mmol/L Tris–HCl, 50 mmol/L KCl), 2.5 mmol/L of MgCl2, 10 mmol/L of deoxynucleotide triphosphate, 5 U/mL of Taq Polymerase and 20 μmol/L of each primer. The PCR program was run at 94°C for 3 min, followed by 30 cycles of 95°C for 1 min, 55°C for 30 s and 73°C for 1 min, with a final extension at 72°C for 5 min. Products were visualized by electrophoresis in 2% agarose gel (Figure 1). RESULTS: A total of 123 isolates were tested. Klebsiella pneumoniae was the predominant carbapenemase producer (58.5%). Sixty-six (53.6%) isolates harboured bla(OXA-48) and 47 (38.2%) had bla(NDM). Only one isolate was positive for bla(KPC). Thirteen (10.5%) had both bla(OXA-48) and bla(NDM) and 9 (7%) tested negative for all three genes. CONCLUSIONS: bla (OXA-48) and bla(NDM) being common and bla(KPC) being very rare is expected with the geographical location of the country. Noted high prevalence and co-occurrence of CR genes among CRE isolates is alarming and pose a threat to patient management and infection control of the institution.