Laingshun HuoySrirat PornruangwongChaiwat PulsrikarnSoraya ChaturongakulMahidol UniversityThailand Ministry of Public HealthThailand Ministry of Education2018-11-092018-11-092014-08-01Foodborne Pathogens and Disease. Vol.11, No.8 (2014), 589-59215567125153531412-s2.0-84905215782https://repository.li.mahidol.ac.th/handle/123456789/33001In order to better understand the relationship between Salmonella serotypes Typhimurium and its monophasic variant 4,5,12:i:- found in Thailand, a total of 138 isolates from various sources were characterized using different molecular subtyping methods (i.e., pulsed-field gel electrophoresis [PFGE] and polymerase chain reaction [PCR]) and antibiotic resistance (AbR) patterns. PFGE revealed 52 distinct band patterns among these isolates, 3 of which were shared between the two serotypes. PCR characterization of genomic deletion patterns reveals that Thai S. 4,5,12:i:- isolates contain a distinct deletion pattern in the fljAB region, which can be used as a specific genetic marker for primary identification of S. 4,5,12:i:- sources. AbR study shows that, among 50 representative serotype-confirmed strains, 48.28% (14/29) of Salmonella Typhimurium and 90.48% (19/21) of 4,5,12:i:- isolates are multidrug-resistant Salmonella as they are resistant to at least 3 antimicrobial categories. The AmpST pattern for resistance to ampicillin, streptomycin, and tetracycline was found in high proportions of Salmonella Typhimurium (10 of 29) and S. 4,5,12:i:- (15 of 21) isolates. © Copyright 2014, Mary Ann Liebert, Inc. 2014.Mahidol UniversityAgricultural and Biological SciencesImmunology and MicrobiologyMedicineArticleSCOPUS10.1089/fpd.2013.1723