Influence of coccidiosis on Salmonella colonization in broiler chickens under floor-pen conditions.

The influence of coccidiosis on colonization of Salmonella typhimurium in broiler chickens under floor pen conditions was studied by semiquantitative methods. Chickens of two groups, unmedicated and medicated with nicarbazin (125 ppm via the feed), were exposed to three species of Eimeria (Eimeria tenella, Eimeria maxima, and Eimeria acervulina) at 2, 3, and 4 wk of age and given S. typhimurium in the feed 2 days later. Salmonella typhimurium was isolated most often (100%) from ceca of chickens exposed at 3 wk of age. Birds in the unmedicated group were positive for S. typhimurium at a higher rate than those in the medicated group. Salmonella typhimurium was detected in livers only in a few unmedicated birds.

Arakawa A ，Fukata T ，Baba E ，McDougald LR ，Bailey JS ，Blankenship LC ... -  《-》

Effects of infection of Eimeria tenella, E. acervulina, and E. maxima upon Salmonella typhimurium infection in chickens.

Three experiments were conducted to examine whether Salmonella typhimurium infection is enhanced by concurrent infection with Eimeria tenella, E. acervulina, or E. maxima. There were two groups in each experiment: birds infected with a daily oral dose of approximately 1 X 10(4) cfu of S. typhimurium for 5 days after coccidial infection and birds infected with S. typhimurium alone with the similar exposure schedule. Chickens were necropsied 7, 10, and 14 days after coccidial infection. The numbers of S. typhimurium in the contents of ceca and small intestine were counted, and numbers of chickens positive for S. typhimurium in the liver and bile were examined. In E. tenella infection, the S. typhimurium counts in the ceca and small intestine of concurrently infected chickens were significantly greater than those of birds infected with S. typhimurium alone. In E. acervulina infection, the S. typhimurium counts in the ceca of chickens killed 14 days after E. acervulina infection and the numbers of birds positive for S. typhimurium in the ceca of chickens killed 10 and 14 days after E. acervulina infection were significantly greater than those of chickens infected with S. typhimurium alone. In E. maxima infection, the numbers of birds positive for S. typhimurium in the ceca and liver of chickens killed 7 days after E. maxima infection were significantly greater than those of birds infected with S. typhimurium alone. Results of this study indicate that infection with E. acervulina or E. maxima is able to enhance S. typhimurium infection in chickens.

Takimoto H ，Baba E ，Fukata T ，Arakawa A ... -  《-》

Establishment and persistence of Salmonella typhimurium infection stimulated by Eimeria tenella in chickens.

Baba E ，Fukata T ，Arakawa A 《RESEARCH IN VETERINARY SCIENCE》

The Contribution of Eimeria Coinfection and Intestinal Inflammation to Cecal Colonization and Systemic Spread of Salmonella Typhimurium Deficient in Tetrathionate Reductase or Type III Secretion Systems Salmonella Pathogenicity Island 1 or 2.

Intestinal inflammation may provide a growth advantage for and enhance its systemic spread in chickens. triggers intestinal inflammation in the host by using type III secretion systems (T3SS) and produces the inflammatory end product tetrathionate. In mice, tetrathionate respiration confers a growth advantage for Typhimurium over the competitive microbiome in the inflamed intestine. Coccidia also promote intestinal inflammation and enhance intestinal growth and systemic spread in chickens. The objective of this study was to evaluate the contribution of inflammation, induced by spp. or Typhimurium, to colonization and dissemination in chickens. In addition, the fitness costs associated with defects in tetrathionate reductase and T3SS associated with Pathogenicity Island 1 or 2 (SPI-1 or SPI-2) were evaluated in competition experiments with wild-type strain, with or without coinfection. One-day-old specific-pathogen-free chickens were orally inoculated with a sham inoculum or with 4 × 10 oocysts cocktail of , , , and . At 6 days of age, birds were orally administered a 1:1 ratio of Typhimurium wild-type and mutant deficient in tetrathionate reductase, SPI-1, or SPI-2 (10 colony forming units/bird). Ceca, livers, and drumsticks were collected at 3, 7, 14, and 42 days after infection, for bacteriology. Intestinal inflammation was scored by histology. Significantly higher intestinal inflammation was observed in challenge groups compared with the control. However, there were no significant differences in intestinal inflammation scores between groups coinfected with both spp. and Typhimurium and birds infected with alone, and coinfection did not increase prevalence or abundance. Contrary to mouse studies, tetrathionate reductase did not enhance Typhimurium cecal colonization or systemic spread in chickens. SPI-1 and SPI-2 played a significant role in dissemination and cecal colonization in chickens, respectively.

Rimet CS ，Maurer JJ ，Berghaus RD ，Jordan BJ ，da Silva LHA ，Stabler LJ ，Johnson KK ，Tensa LR ，Segovia KM ，França MS ... -  《-》

Eimeria tenella infection enhances Salmonella typhimurium infection in chickens.

Arakawa A ，Baba E ，Fukata T 《-》