Investigation of blaKPC and blaNDM genes in enterobacteriaceae received in a public health laboratory

Abstract

Introduction: KPC and NDM carbapenemases production is an important enzymatic mechanism of resistance to carbapenens in bacteria belonging to the Enterobacteriaceae family. These enzymes degrade virtually all beta-lactam antibiotics and are encoded by the blaKPC and blaNDM genes, which can be in mobile genetic elements such as plasmids and transposons. Objectives: This study evaluated the positivity rate of the presence of blaKPC and blaNDM genes in carbapenem-resistant enterobacteria received at the Instituto Adolfo Lutz (IAL) of São José do Rio Preto, Brazil and determined the epidemiological data related to the patients whose isolates were recovered. Methods: From June 2015 to April 2019, bacterial isolates were obtained from different hospitals located in five municipalities in São José do Rio Preto region. In the bacteriology and molecular biology laboratory, DNA extraction and real-time PCR were performed to investigate the blaKPC and blaNDM genes. Afterwards, epidemiological data were surveyed such as the municipality of origin, age, and gender of the patients whose bacterial isolates were recovered. Results: A total of 934 enterobacteria isolates were recovered from the different hospitals. Of these; 93.4% were positive for blaKPC, with 96.3%, 1.85%, and 1.85% of the isolates belonged to the Klebsiella genus, Enterobacter genus, and Escherichia coli species, respectively. Also, 52.5% and 84.4% of the isolates were obtained from women and elderly patients, respectively. The blaNDM gene was detected only in three isolates, two of which originated from surveillance cultures. Conclusion: Therefore, KPC-producing enterobacteria are widespread in all health units of the five municipalities that were studied, suggesting that the blaKPC-carrying Klebsiella sp. isolates may be endemic in these institutions. Additionally, there is a significant role of surveillance cultures in preventing the spread of resistance genes, as observed for blaNDM in this study.