Genotypic and Phenotypic Diversity of Salmonella Enteritidis Isolated from Chickens and Humans in Korea

Abstract

ABSTRACT. Salmonella Enteritidis is the most common cause of salmonellosis in humans in South Korea. It has been recognized that the principal source of human infection with S. Enteritidis is chickens and their products such as meat and eggs. A total of 173 S. Enteritidis isolates from humans (65 isolates) and chickens or their products (108 isolates) were analyzed by antibiotic susceptibility assay, phage typing, and pulsed-field gel electrophoresis (PFGE). Drug resistance was found to streptomycin (32.3%), ampicillin (30.6%), nalidixic acid (30.1%), ticarcillin (30.1%), and tetracycline (28.3%). More than 70% of the isolates were found to be resistant to one or more antibiotics tested. The most frequent patterns of resistant isolates were resistance to nalidixic acid only (28.3%) and resistance to two antibiotics (four combinations; 20.2%). The most predominant phage type (PT) was PT1 (27.2%) followed by PT21 (20.8%) and PT4 (8.7%) in chicken and human isolates. Nineteen different PFGE patterns were found among the 173 isolates, and A1 was the most common PFGE pattern, followed by A6 (17.3%). Most S. Enteritis isolates (except two isolates with patterns B and C) showed similar PFGE patterns that differed by only a few bands. These results show that 2 or 3 subtypes of S. Enteritidis are shared to a large extent by humans and chickens. This implies the possibility of the spread of chicken S. Enteritidis to humans.

Antibiotic resistance phenotypes of Salmonella isolates of broiler meat and chicken origin

“…Previously, high resistance to erythromycin in broiler Salmonella isolates was reported by Bekele and Ashenafi (3), who similarly had detected high resistance results for penicillin G, doxycycline hydrochloride in parallel to our findings. Also, the resistance rates determined in this study for the chicken isolates were in agreement with previous reports for tetracycline (5,12), oxytetracycline (10), ciprofloxacin and enrofloxacin (5), enrofloxacin and penicillin G (14), cephalexin and cephazolin (3), streptomycin and ampicillin (3,5,12), amoxycillin/clavulanic acid (3), and ceftiofur (10). The resistance rate observed in the broiler isolates for sulphamethoxazole/trimethoprim 19:1 was relatively lower than previously reported by Ishihara et al (10) in chicken isolates.…”

“…In recent years, there are several reports on Salmonella isolates that are resistant to several antimicrobial agents (Multi Drug Resistant -MDR) both in the developed and developing countries from chicken meat (4,15,17,18,21,22,23), and from chickens (3,5,7,10,12). The emergence of these MDR Salmonella has significant outcomes for the safety of the food supply, namely chicken meat, directly as a source of MDR Salmonella, and indirectly as a reservoir of antimicrobial genetic elements that can be exchanged between intestinal bacteria (2).…”

Studies on Occurrence of Invasive Salmonella spp. from Unorganised Poultry Farm to Retail Chicken Meat Shops in Mumbai City, India

“…Human salmonellosis is frequently associated with the consumption of poultry products (CDC, 2008;Hanning et al, 2009;Kang et al, 2009 andPires et al, 2012). Contaminated poultry products are among the important sources for food-borne outbreaks in humans and Salmonella are isolated more often from poultry and poultry products (Habtamu et al, 2011;Kabir, 2010 andLinam andGerber, 2007).…”

Genotyping, Phage Typing, and Antimicrobial Resistance of Salmonella Typhimurium Isolated from Pigs, Cattle, and Humans

“…Pang et al (2007) reported that PFGE subtypes of S. Enteritidis showed about 75% homogeneity regardless of the geographic area and host source of the isolates. It was reported that PFGE patterns generated from the XbaI enzyme were very similar among S. Enteritidis strains (Kang et al, 2009;Laconcha et al, 2000;Woo, 2005). In this study, PFGE patterns with a single band difference were considered distinct, and 43 PFGE RDNC: Reacts with phages but does not confirm to a recognized pattern 2 ) patterns were grouped into 14 main clusters at 75% similarity by BioNumerics software.…”