NEW DELI METALLO-BETA-LACTAMASE AND OTHER CARBAPENEMASES AMONG EXTREME ANTIBIOTIC-RESISTANT KLEBSIELLA PNEUMONIAE: OCCURRENCE IN BELARUS
Objective: To estimate the prevalence of different types of carbapenemases among extreme antibiotic-resistant Klebsiella pneumoniae circulating on the territory of the Republic of Belarus.
Materials and methods. The antibiotic resistance and production of serine carbapenemases and metallo-beta- lactamases were studied in 109 Klebsiella pneumoniae isolates identified in 2013—2014 in hospitals of the three regions of the Republic of Belarus. The microorganisms were identified basing on the biochemical tests and MALDI-TOF-mass spectrometry results. The antibiotic sensitivity was determined using the disc diffusion method and semi-automatic analyzers. The carbapenemases were identified using the phenotypic tests (the modified Hodge test, the method of double discs with EDTA) and genotypic tests (real-time PCR accompanied by the carbapenemase KPC, OXA-48, NDM, IMP, VIM genes detection).
Results. The sensitivity of the K. pneumoniae isolates studied was 73.4% to imipenem, 69.7%— to meropenem. 22.0% of the isolates were extremely drug resistant (not sensitive to ampicillin, amoxicillin / clavulanate, aztreonam, cefotaxime, ciprofloxacin, amikacin, imipenem and meropenem). Seventeen (15.6%) K. pneumoniae isolates produced OXA-48 carbapenemases, 13 (11.9%) isolates— NDM carbapenemases the results being confirmed by the phenotypic and genotypic tests. No K.pneumoniae isolate with VIM, IMP and KPC carbapenemases production was identified.
Conclusion. Occurrence of Enterobacteriaceae producing NDM and OXA-48 carbapenemases is common in the Belarus healthcare settings and can lead to an inadequate empirical antibiotic therapy of such infections and result in the number of complications and adverse outcomes increasing in hospitalized patients as well as in further aggravating of resistance to carbapenems and developing of pandrug resistant isolates. It is necessary to organize systematic multi-center microbiological studies for identifying extremely antibiotic-resistant Gram-negative bacteria with the definition of the key mechanisms of the antibiotic resistance using phenotypic and genotypic methods in addition to monitoring the overall level of the key microorganisms resistance to certain antibiotics. It will improve the infection control system functioning significantly.