Monitoring of antibiotic resistance of non-fermenting bacteria circulating in hospitals in Rostov-On-Don (2012-2019)

Abstract

Purpose: A significant place among the causative agents of nosocomial infections is occupied by gram-negative non-fermenting bacteria (GNNFB). Monitoring of prevalence, assessment of antibiotic resistance of GNNFB in hospitals allows assessing the risk of occurrence and contributes to the prevention of HCI.The aim of the work was to study antibiotic resistance of non-fermenting bacteria strains identified in multidisciplinary hospitals in Rostov-on-Don. Methods & Materials: In the period 2012-2019, a study of antibiotic susceptibility was carried out on 2709 NGOB cultures isolated in hospitals from different biotopes.The isolated microorganisms were identified using MALDI-TOF based on a Microflex mass spectrometer. Determination of antibiotic susceptibility of bacteria studied with Vitek-2 (bacteriological analyzer and a standard disk diffusion method. Results: Monitoring of non-fermenting bacteria in hospitals revealed that GNNFB was detected in 5 - 28% of all identified potential pathogens of HCI.Pseudomonas spp. remained dominant in 2012-2013 - 83-85% and somewhat less in 2018-2019 - 48-60%. We determined an increase in the share of Acinetobacter spp. from 7-8% in 2012-2013 to 37-41% in 2018-2019. Other GNNFB and Stenotrophomonas spp. did not exceed 13% of all detected non-fermenting bacteria.In 2012-2013 among the strains of GNNFB isolated in hospitals, there were still variants of cultures that are sensitive to groups of antibiotics used for a long time in medical practice: to aminoglycosides of the 1st generation (Am I), cephalosporins of the 1st generation (Cef II), semisynthetic penicillins of the 1st generation (Pen I)). Until 2015, GNNFB had become almost 100% resistant to these drugs. we registered an increase of the resistance of GNNFB to antibiotics of later generations: to fluoroquinolones (Ftorh), aminoglycosides of the 2nd generation (Am II), cephalosporins of the 3rd generation (Cef III), semisynthetic penicillins of the 2nd generation (Pen II), macrolides (Mac). Conclusion: At the beginning of our observation period, we identified 25-30% of resistant strains, at the end - 60-80%.The antibiotic resistance of GNNFB continued to increase during the observation period. The drugs of choice for the treatment of infectious diseases remain carbapenems (45% of resistant crops in 2019) and drugs of the nitrofuran series (50% -2019).