Comparison Study on Colonization of hilA Mutant and Parent Strains of Salmonella enteritidis in Vertically Infected Broiler Chickens
AbstractBackground: Salmonella actively stimulates its own uptake into the epithelial cells by inducing cytoskeleton rearrangements and membrane ruffling triggered by some proteins secreted by Salmonella into the cytosol of the epithelial cells via a type III secretion system (TTSS) encoded by genes of the Salmonella pathogenicity island 1 (SPI-1). hilA is a transcriptional activator encoded on Salmonella Pathogenicity Island 1 (SPI-1) genes.Methods: To assess the importance of hilA in a simulation modeling of vertical infection and shedding of S. enteritidis in broiler chickens a long-term experiment was designed. Two groups of 200 fertile eggs were inoculated with 20 colony forming units (CFU) of hilA mutant of S. enteritidis or its parent strain just prior to incubation. Thirty five birds of each group were housed in separate rooms. On days 2, 4, 7, 14, 21, 28 and 35 of age, cloacal swabs from live birds as well as samples from internal organs (intestinal tract, liver and spleen) were evaluated by bacteriological or molecular methods.Results: In most of sampling days colonization and invasion of parent strain S. enteritidis in intestine (especially ceaca) and internal organs of chickens were higher with compared to its hilA mutant but this mutant strain could still colonize in intestinal tract and even invade liver or spleen.Conclusion: Colonization of hilA mutant of S. enteritidis indicated that hilA gene is only one part of the modulators in Salmonella invasion mechanism. The ability of hilA mutant to multiply and persist in host internal organs including ceaca may promise further research for potential of hilA mutant to prevent the initial colonization of the intestinal tract by a virulent S. enteritidis strain
Eurosurveillance editoral team, et al. The European Union summary report on trends and sources of zoonoses, zoonotic agents and food-borne outbreaks in 2012. Euro surveillance: bulletin Européen sur les maladies transmissibles European communicable disease bulletin, 2012,17.10.
Mirzaie S, Hassanzadeh M, Ashrafi I.Identification and characterization of Salmonella isolates from captured house sparrows. Turk J Vet Anim Sci 2010; 34 (2): 181- 186.
Bohez L, Ducatelle R, Pasmans F, Botteldoorn N, Haesebrouck F, Van Immerseel F. Salmonella enterica serovar enteritidis colonization of the chicken caecum requires the HilA regulatory protein. Vet Microbiol 2006; 116: 202-210.
Desmidt M., Ducatelle R, Haesebrouck F.Pathogenesis of Salmonella enteritidis phage type four after experimental infection of young chickens. Vet Microbiol 1997; 56: 99- 109.
Pan TM, Liu YJ. Identification of Salmonella enteritidis isolates by polymerase chain reaction and multiplex polymerase chain reaction. J Microbiol Immunol Infect 2002; 35: 147- 151.
Madadi MS, Azari M, Yazdani A.Evaluation of different plating medias and PCR in the detecting of Salmonella enteritidis from eggs laid by experimentally infected hens J Anim Poult Sci 2012; 1(1):13-23.
Madadi MS, Hassanzadeh, M, Nikbakht GhR, Bozorgmehrifard M, Shojaei H. A comparative study on the colonization of Salmonella enteritidis hilA mutant and its parentstrains in laying hens. Iran J Vet Med 2013; 6 (4): 327- 333.
Lichtensteiger CA, Vimr ER. Systemic and enteric colonization of pigs by a hilA signature tagged mutant of Salmonella Choleraesuis. Microb Pathogenesis 2003;34: 149-154.
Morgan E, Campbell JD, Rowe SC, Bispham J, Stevens MP, Bowen J. Identification of host-specific colonization factors of Salmonella enterica serovar Typhimurium. Mol Microbiol 2004; 54: 994-1010.
Bohez L, Ducatelle R, Pasmans F, Botteldoorn N, Haesebrouck F, Van Immerseel F. Long- term colonization- inhibition studies to protect broilers against colonization with Salmonella enteritidis, using Salmonella Pathogenicity Island 1 and 2 mutants. Vaccine 2007; 25: 4235-4243.