Abstract
Salmonella enterica serovar Typhimurium is a common cause of non-typhoid salmonellosis in humans. Since 2006, an increase in the human infections caused by U302 phage type in Slovakia has been documented and, from 2006 to 2011, a total of 291 U302 human strains were isolated. Antimicrobial susceptibility testing demonstrated that these strains had a high overall antimicrobial resistance and 244 (83.8%) of the tested strains were multidrug-resistant (MDR). The most prevalent resistance was to ampicillin, streptomycin, sulfisoxazole, and tetracycline (R-type ASSuT), which was verified in 87 (29.9%) strains. The annual rate of this resistance type varies, but the largest number of these strains were identified in 2009 and 2010. The classical pentaresistance phenotype (R-type ACSSuT), characteristic of the DT104 phage type, was found only in 40 (13.7%) U302 strains. These results suggested that although the prevalence of DT104 phage type has decreased, ASSuT as well as ACSSuT resistance markers continue to circulate. Therefore, continual surveillance of the occurrence of these and similar MDR phage types is necessary.
