Experimental infection of laying hens with Salmonella enterica serovar Gallinarum

Abstract

Experimental infections were set up in commercial laying birds, comprising a white relatively resistant line and a red susceptible line infecting with Salmonella enterica serovar Gallinarum. The major findings were that in susceptible birds clinical disease occurred in a dose-dependent manner. Faecal excretion occurred in susceptible birds almost up to death but also occurred in the more resistant line and in birds, which were convalescing. Removal of birds, which had died from the disease, from the environment, reduced the resultant mortality/ morbidity and may be regarded as a useful measure for control.

Experimental infection of one-day-old chicks with Salmonella Serotypes Previously isolated from poultry facilities, wild birds, and swine

“…to investigate the pathogenicity of this agent (Pinheiro et al, 2001;Oliveira et al, 2005;Ribeiro et al, 2005).…”

“…in specimens collected from poultry facilities, local wild birds, and swine reared on the same farm. After the collected bacteria were cultured, broiler chicks were inoculated with the isolated serotypes and evaluated for disease (Pinheiro et al, 2001;Oliveira et al, 2005;Ribeiro et al, 2005).…”

A defective mutant of Salmonella enterica Serovar Gallinarum in cobalamin biosynthesis is avirulent in chickens

“…It is one of a small group of serovars that typically produces typhoid-like infections in a narrow range of host species and which therefore represents a good model for human typhoid. The disease is most severe where environmental conditions and management systems do not allow hygienic control measures to be introduced (36).…”

Dissemination of Salmonella enteritidis by experimentally-infected pigeons

“…Gast et al (2011) reported that both the frequency of microbial invasion and the recovery of the number of pathogen cells in the liver can vary significantly depending on the exposure dose administered. Oliveira et al (2005) showed that in hens orally inoculated with a lower dose of Salmonella (8.5 x 10 5 CFU/mL), the pathogen was recovered in the liver and the spleen only on 7 dpi, while in birds inoculated with the highest concentration (8.5 x 10 8 CFU/mL), it was recovered already did on 3 dpi. This indicates that both concentrations used in the present experiment may not have been sufficient to promote invasion of the liver and the spleen by the pathogen already on 3 dpi.…”

“…The following variables were analyzed: SE concentration in the feces and in organs, frequency of positive swabs, organ and fecal samples. The inoculation and evaluation of the concentration of Salmonella Enteritidis in organs and feces was performed according to the methodology adopted by Oliveira et al (2005).…”