The role of roof rats ( Rattus rattus) in the spread of Salmonella Enteritidis and S. Infantis contamination in layer farms in eastern Japan

• Published in: Epidemiology and Infection
• Main Authors: LAPUZ, R., TANI, H., SASAI, K., SHIROTA, K., KATOH, H., BABA, E.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Cambridge University Press (CUP) 2007
• Subjects: Rattus rattus
• Online Access: http://dx.doi.org/10.1017/s095026880700948x; https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S095026880700948X

SUMMARY The prevalence of Salmonella in four layer farms in eastern Japan was investigated between 2004 and 2006 to determine the role of roof rats ( Rattus rattus ) in the epizootology of Salmonella enterica subsp. enterica serovar Enteritidis ( S . Enteritidis). Persistent S . Enteritidis and S . Infantis contamination of the environment and pooled egg samples were detected in three out of four layer farms. A total of 113 (13·3%) and 158 (18·6%) out of 851 rats examined were positive for S . Enteritidis and S . Infantis, respectively. By pulsed-field gel electrophoresis, only one indistinguishable pulsed-field pattern was yielded by S . Enteritidis strains from rats, eggs and environmental samples from each of the two contaminated layer farms. Although, a variety of pulsed-field patterns were generated by S . Enteritidis isolates from rats, eggs, and the environment of the other contaminated farms, there are, however, some S . Enteritidis strains that are closely related clones. These results suggest that roof rats are carriers of S . Enteritidis and S . Infantis and that persistent S . Enteritidis and S . Infantis infections in a rat population may play an important role in the spread and maintenance of these pathogens inside the layer premises.