Comparative Phenotypic and Genotypic Characterization of Salmonella spp. in Pig Farms and Slaughterhouses in Two Provinces in Northern Thailand

Abstract

Salmonella spp. are an important group of bacterial zoonotic pathogens which can cause acute food-borne diseases in humans. Pork products are the main source of salmonellosis, but the origins and transmission routes of the disease have not been clearly determined. The purpose of this study was to characterize Salmonella spp. isolated in pig production lines both from pig farms and from slaughterhouses in Chiang Mai and Lamphun provinces in northern Thailand. The study focuses on the association among serotypes, antimicrobial resistance patterns and Pulse Field Gel Electrophoresis (PFGE) patterns to investigate possible sources of infection and to provide information which could help strengthen salmonellosis control programs in the region. A total of 86 strains of Salmonella comprising five majority serotypes were identified. Antibiotic resistance to tetracycline was found to be the most prevalent (82.56%) followed by ampicillin (81.40%) and streptomycin (63.95%). Seven clusters and 28 fingerprint-patterns generated by PFGE were identified among strains recovered from various locations and at different times, providing information on associations among the strains as well as evidence of the existence of persistent strains in some areas. Study results suggest that Salmonella control programs should be implemented at slaughterhouse production lines, including surveillance to insure good hygiene practices, in addition to regular monitoring of large populations of farm animals.

Quantification and rep‐PCR characterization of Salmonella spp. in retail meats and hospital patients in Northern Thailand

“…Salmonella Weltevreden and S. Rissen have been reported to be the most common serotypes found in animal farms and retail meats in South and Southeast Asia (Sinwat et al, ; Tadee, Boonkhot, Pornruangwong, & Patchanee, ), which aligns with our findings in this study. In different geographical areas, the leading Salmonella serotypes isolated from retail meat varies, for example, S. Thompson in Iran (Sodagari, Mashak, & Ghadimianazar, ), S. Montevideo in the United States (Bosilevac, Guerini, Kalchayanand, & Koohmaraie, ) and S. Typhimurium in Denmark (Bruun et al, ).…”

Detection of <i>Salmonella enterica</i> Serovar Rissen in Slaughter Pigs in Northern Ireland

“…This study supports other research that multidrug resistance is less common amongst S. Rissen isolates when compared to the antibiotic resistance characteristics of S. Typhimurium isolates [19] [26]. However, S. Rissen displaying multidrug resistance has been recorded including a study conducted in Spain which identified 48 of 114 S. Rissen isolates as MDR ranging from four to nine antimicrobials [26] and Thailand where S. Rissen displayed resistance from one to five antibiotics [27].…”

Antimicrobial Usage and Antimicrobial Resistance in Animal Production in Southeast Asia: A Review

“…In three publications, AMR was investigated in both E. coli and NTS isolates. The majority of publications included data from Thailand (20) [27,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44] and Vietnam (15) [18,23,45,46,47,48,49,50,51,52,53,54,55]. One publication was found with data from each of Cambodia, Indonesia, Lao PDR and Malaysia [56,57,58,59].…”

“…The overall estimates for AMR in chickens, pigs, aquaculture, and other host species among studies for the 11 most common antimicrobials tested are shown in Figure 1 and Figure 2 for E. coli and NTS isolates, respectively. Data from two publications including AMR phenotypic results for NTS isolates from pigs and poultry combined [30,42] were not plotted.…”

“…Resistance against ceftazidime, ceftiofur, ceftriaxone, norfloxacin, ciprofloxacin, and cefotaxime was <0.1%. In all studies investigating phenotypic resistance against third-generation cephalosporins in NTS strains, the prevalence found was <5%, except for two studies in Thailand, where cefotaxime prevalence in pig isolates was ~12% [38,42]. …”