title: Prevalence and characteristics of Salmonella spp. isolated from commercial layer farms in Korea.
abstract: Salmonellosis is one of the most prevalent foodborne illnesses. The outbreak of this disease is often associated with eggs. In this study, the prevalence and characteristics of Salmonella was surveyed in layer farms in Korea. In addition, the risk factors affecting the prevalence of Salmonella in these farms were also assessed. Of the 32 farms and 67 flocks examined, 19 farms (59.3%) and 34 flocks (50.7%) were observed to be positive for Salmonella contamination. Salmonella was detected in the surrounding environment such as feces (41.8%), dust (40.3%), egg shells (17.2%), as well as the internal egg contents (5.2%). The incidence of Salmonella positives were tended to increase when the flock size is larger (P = 0.021). Differences in the provinces also affected Salmonella prevalence (P < 0.001). The most frequently observed Salmonella serovars in the flocks were Salmonella Bareilly (41.2%), Salmonella Mbandaka (32.4%), and Salmonella Rissen (17.6%). Twenty of the flocks revealed multi-serovar contamination, with the isolation of 2 to 4 serovars. Antimicrobial susceptibility testing revealed that 93 out of 101 isolates were susceptible to the 17 tested antimicrobial agents. The remaining isolates displayed resistance to ampicillin (4.0%), nalidixic acid (3.0%), tetracycline (1.0%), cephalothin (1.0%), and gentamicin (1.0%). As human salmonellosis has been repeatedly correlated to the consumption of poultry products worldwide, continuous studies are required to effectively minimize the Salmonella contamination in layer farms and egg products.
authors.affiliation: Department of Public Health, College of Veterinary Medicine, Kyungpook National University, 702-701, Daegu, Republic of Korea.
authors.forename: Min Chan
authors.initials: MC
authors.lastname: Im
authors.affiliation: Department of Public Health, College of Veterinary Medicine, Kyungpook National University, 702-701, Daegu, Republic of Korea.
authors.forename: So Jeong
authors.initials: SJ
authors.lastname: Jeong
authors.affiliation: Animal and Plant Quarantine Agency, 175 Anyangro, Manan-gu, Anyangsi Gyeonggido, 480-757, Anyang, Republic of Korea.
authors.forename: Yong-Kuk
authors.initials: YK
authors.lastname: Kwon
authors.affiliation: Animal and Plant Quarantine Agency, 175 Anyangro, Manan-gu, Anyangsi Gyeonggido, 480-757, Anyang, Republic of Korea.
authors.forename: Ok-Mi
authors.initials: OM
authors.lastname: Jeong
authors.affiliation: Animal and Plant Quarantine Agency, 175 Anyangro, Manan-gu, Anyangsi Gyeonggido, 480-757, Anyang, Republic of Korea.
authors.forename: Min-Su
authors.initials: MS
authors.lastname: Kang
authors.affiliation: Department of Public Health, College of Veterinary Medicine, Kyungpook National University, 702-701, Daegu, Republic of Korea youngju@knu.ac.kr.
authors.forename: Young Ju
authors.initials: YJ
authors.lastname: Lee
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D002645:Chickens; D005260:Female; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D011201:Poultry Diseases / Q000453:epidemiology / Q000382:microbiology*; D015995:Prevalence; D056910:Republic of Korea / Q000453:epidemiology; D012307:Risk Factors; D012475:Salmonella / Q000187:drug effects / Q000302:isolation & purification / Q000502:physiology*; D012481:Salmonella Infections, Animal / Q000453:epidemiology / Q000382:microbiology*
chemical_list: D000900:Anti-Bacterial Agents
keywords: Salmonella; antimicrobial susceptibility; layer farm; prevalence; risk factor