Characterization of non-typhoidal Salmonella enterica strains of human origin in central and southern Italy

Non-typhoidal infection is a significant public health problem worldwide. The aim of this study was to characterize strains isolated from human specimens in central and southern Italy, for epidemiological studies. One hundred and fifty strains were serotyped. Isolates were tested for their antimicrobial susceptibility, by disk diffusion method. The molecular characterizations, based on PCR, were carried out for the detection of gene and other virulence elements and phage marker genes. Eighteen different serotypes were identified. The most common serotypes detected were Typhimurium, Enteritidis, the monophasic variant of Typhimurium ( 4,[5],12:i:-), and Napoli. High resistance rates were recorded for tetracycline (64%), streptomycin (62%), sulphonamide (57%), and ampicillin (56%). The ASSuT R-type, also associated to resistance to other antibiotics, was highly prevalent in 4,[5],12:i:- (97%) and Typhimurium (55%), while the ACSSuT R-type, also associated to other antibiotics, was observed prevalently in Typhimurium (20.4%). The genes of more common detection were (100%), (86.6%), (84.6%), (80%), (77.3%), (52.6%), (52.6%).