Investigation of Azithromycin Minimum Inhibitory Concentration Values and Carbapenem Resistance in Salmonella and Shigella Clinical Isolates

In this study, we aimed to evaluate the susceptibility of Salmonella and Shigella species to azithromycin, to determine and compare the minimum inhibitory concentration (MIC) values and disk diffusion zone diameters. In addition, susceptibility to meropenem and first-line antibiotic options in isolates was also investigated. A total of 170 Salmonella, 76 Shigella clinical isolates collected between 2014 and 2018 in our hospital were tested for their susceptibility to azithromycin, meropenem, ampicillin, pefloxacin, trimetoprim-sulfamethoxazole, ceftazidime, and cefotaxime. Isolates were identified by matrix-assisted laser desorption ionization time of flight mass spectrometry. The isolates were confirmed and serotyped by the reference laboratory using the conventional slide agglutination method. Susceptibility of the isolates to azithromycin and other antibiotics was evaluated by Kirby-Bauer disk diffusion method. MIC values of azithromycin were determined by the reference broth microdilution method. Combined disk diffusion test was used for the detection of extended spectrum beta-lactamase (ESBL) production. Polymerase chain reaction was performed for macrolide and carbapenem resistance genes and the detected resistance genes were confirmed by sequencing. Of the 76 Shigella isolates tested, 64 (84.2%) were identified as Shigella sonnei, 10 (13.2%) as Shigella flexneri, one (1.3%) as Shigella boydii, and one (1.3%) as Shigella dysenteriae. Among the 170 Salmonella isolates, 1...
Source: Mikrobiyoloji Bulteni - Category: Microbiology Authors: Source Type: research