Prevalence of bla KPC and its occurrence with other beta-lactamases in Klebsiella pneumoniae .

BACKGROUND: Klebsiella pneumoniae ( K. pneumoniae ) is an important nosocomial pathogen, and the emergence of multidrug resistance in these organisms limits the treatment options for serious infections caused by them. K. pneumoniae carbapenemase (KPC) is one of the clinically significant Class A beta-lactamases.

AIM AND OBJECTIVE: This study was aimed to detect the KPC and its coexistence with other beta-lactamases in K. pneumoniae .

MATERIALS AND METHODS: A total of 370 isolates, collected over a period of 1 year, were included in this study. The source of these isolates were urine ( n = 170), exudative specimens ( n = 132), respiratory secretions such as bronchial wash, endotracheal aspirate, and pleural fluid ( n = 38), and blood ( n = 30). For all the isolates, antibiotic susceptibility tests by disc diffusion, modified Hodge test, and KPC screening test were done. Polymerase chain reaction (PCR) was performed for the detection of KPC and the copresence of other beta-lactamases genes.

RESULTS: Among the 370 isolates, 41 were resistant to the carbapenem by disc diffusion and minimum inhibitory concentration tests. Screen test using ertapenem and the boronic acid disk was positive in 14 isolates. Only one isolate harbored KPC gene by PCR, and it was co-produced with SHV-12 and CTX-M-15.

CONCLUSION: PCR remains the gold standard for detection of KPC compared with any other phenotypic methods. Early detection of these genes helps in initiating proper antibiotic treatment.