Modern problems of antibiotic resistance gram-negative nosocomial infections in the Rostov region

Abstract

Objectives: to analyze the prevalence of strains of gram-negative bacteria - pathogens of infectious complications resistant to carbapenems, including through the production of carbapenemases isolated from various clinical biomaterials in hospitalized patients of hospitals in the city of Rostov-on-Don.Materials and methods: 366 gram-negative bacterial isolates were studied, from patients from 16 wards, 9 treatment-and-prophylactic institutions of the city of Rostov-on-Don and the region. The study was conducted by traditional microbiological method. Species identification of strains and sensitivity to antimicrobial drugs were determined on a Vitek 2 automatic analyzer (BioMerieux, France). The strains insensitive to carbapenems were tested for the presence of carbapenemases using CIM-test. MBL was detected by the effect of suppression of their activity in the presence of EDTA. MBL genes were detected by PCR-RV test kit “AmpliSens MDR MBL-FL”, “AmpliSens MDR KPC/OXA-48-FL”. The conclusion about the production of BLRS was made by the presence of synergism of cephalosporins of III-IV generation with clavulanic acid by the method of double discs.Results: of the 366 isolates tested, gram-negative bacteria accounted for 74.2 %: Klebsiella pneumoniae — 33.0 %, Escherichia coli — 19.0 %, Acinetobacter baumannii — 18.0 %, Pseudomonas aeruginosa — 15.0 %. Resistance to carbapenems was detected in 90.9 % of A.baumannii strains, more than 50 % of P.aeruginosa and K.pneumoniae. LBR production was detected in more than 90 % of K.pneumoniae and about 80 % of E. coli. In A. baumannii and K.pneumoniae isolates, the presence of OXA and NDM genes was found, and in P.aeruginosa, VIM groups.Conclusion: enterobacteria resistant to beta-lactams, producing extended-spectrum beta-lactamases and carbapenemases are one of the leading causative agents of infectious complications in hospitals of Rostov-on-don and the region, almost not inferior in frequency of occurrence of bacteria of the genus Acinetobacter spp. and Paeruginosa. This determines the importance of detection of resistance mechanisms not only for the purpose of optimal etiotropic therapy, but also for epidemiological control of the spread of resistant strains and the development of infection control measures.

Keywords

• antibiotic resistance
• gram-negative bacteria
• β-lactams
• carbapenemases