serovars in a tertiary hospital in Turkey, 2015-2017: molecular epidemiology, antimicrobial resistance and molecular characteristics of resistance mechanisms.

BACKGROUND

Increase in antimicrobial resistance poses a global threat for treatment of Salmonellosis.

OBJECTIVES

In this study, serovar distribution, antimicrobial susceptibility, resistance genes, and clonal diversity were characterized in clinical isolates.

METHODS

In this study, serovar distribution of clinical isolates was characterized by the Kauffman-White scheme. The antimicrobial susceptibility was determined by the broth microdilution method. Resistance genes and clonal diversity were investigated by PCR and PFGE.

RESULTS

The serovars were serovar Enteritidis (n=92), serovar Typhimurium (n=14), and others (n=25). Resistance to ciprofloxacin, ceftriaxone, trimethoprim-sulfamethoxazole, azithromycin, meropenem, and colistin were 13.3%, 2.2%, 5.2%, 3.0%, 0%, 29.6%, respectively. Two ESBL-positive isolates carried TEM-type β-lactamases. Carbapenemases, -1 and -2 could not be detected. Colistin-resistant S. Enteritidis isolates were grouped in 4 pulsotypes [A1 (n=12), A2 (n=2), A3 (n=13) and B (n=1)]. All except one (B) were found closely related.

CONCLUSIONS

A relative decrease in resistance to trimethoprim-sulfamethoxazole was detected with time. Trimethoprim-sulfamethoxazole and azithromycin can be good alternatives to the widely-used ciprofloxacin and third-generation cephalosporins. High resistance of colistin and ciprofloxacin may be due to the extensive use of antibiotics in poultry, which highlights the significance of one health concept.