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Pathogenic traits of Salmonella Montevideo in experimental infections in vivo and in vitro

View Article: PubMed Central - PubMed

ABSTRACT

Salmonella serovar Montevideo (SM) is frequently associated with human Salmonella infections and causes gastrointestinal disease, cases are common particularly among individuals who come in close contact with live poultry or poultry meat products. To characterize SM disease in chickens, the pathogenic traits and tissue predilections of the disease were investigated. Dissemination of fluorescent-tagged SM (JOL1575GFP) was monitored after oral and intramuscular mock infections of specific-pathogen-free chickens. The spleen was predominantly affected by intramuscular infection while the cecum, spleen, and minimally liver were affected by oral infection. No conspicuous illness was observed in infected birds, and histopathological examination showed minimal damage of the intestinal epithelium and splenic parenchyma though SM was readily isolated from these tissues. Levels of SM internalization by primary chicken peritoneal macrophages were similar to that of Salmonella Typhimurium. SM was more sensitive to chicken than rabbit serum complement killing. Internal egg contamination of SM mock infected layers also occurred at trace levels and lasted for a week after inoculation. This study also confirmed that SM infection in chickens is sub-clinical and asymptomatic, which suggests that latent asymptomatic carriers may excrete a large number of bacteria and transmit the pathogen by contaminating water or food sources.

No MeSH data available.


Related in: MedlinePlus

Serum complement sensitivity assay.S. Montevideo serotype susceptibility to complement killing was assessed with chicken and rabbit complements. One hour after incubation with complement, viable bacteria were determined by plating on BGA plates. CFU of bacterial strains are represented as percent reduction. (A) SM strains were more susceptible to chicken serum than was the reference ST strain. (B) SM was relatively resistant to rabbit complement. *P ≤ 0.05; error bars indicate the SEM.
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f1: Serum complement sensitivity assay.S. Montevideo serotype susceptibility to complement killing was assessed with chicken and rabbit complements. One hour after incubation with complement, viable bacteria were determined by plating on BGA plates. CFU of bacterial strains are represented as percent reduction. (A) SM strains were more susceptible to chicken serum than was the reference ST strain. (B) SM was relatively resistant to rabbit complement. *P ≤ 0.05; error bars indicate the SEM.

Mentions: To evaluate the sensitivity of SM strains to serum complement killing, JOL1575, JOL1577, and reference ST strains were exposed to chicken and rabbit serum complements. The principle behind the test was to determine the sensitivity of the bacteria to complement-mediated bacterial lysis. Fresh serum contains an active complement system that lysed susceptible organisms, but heat treatment for 30 min at 56 °C inactivated the serum complements leading to decomplementation. The effect of bacterial cell lysis by serum complement killing was measured in CFU. SM was more susceptible to complement lysis by chicken serum than was ST (Fig. 1). However, SM was relatively resistant to complement killing by rabbit serum.


Pathogenic traits of Salmonella Montevideo in experimental infections in vivo and in vitro
Serum complement sensitivity assay.S. Montevideo serotype susceptibility to complement killing was assessed with chicken and rabbit complements. One hour after incubation with complement, viable bacteria were determined by plating on BGA plates. CFU of bacterial strains are represented as percent reduction. (A) SM strains were more susceptible to chicken serum than was the reference ST strain. (B) SM was relatively resistant to rabbit complement. *P ≤ 0.05; error bars indicate the SEM.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384224&req=5

f1: Serum complement sensitivity assay.S. Montevideo serotype susceptibility to complement killing was assessed with chicken and rabbit complements. One hour after incubation with complement, viable bacteria were determined by plating on BGA plates. CFU of bacterial strains are represented as percent reduction. (A) SM strains were more susceptible to chicken serum than was the reference ST strain. (B) SM was relatively resistant to rabbit complement. *P ≤ 0.05; error bars indicate the SEM.
Mentions: To evaluate the sensitivity of SM strains to serum complement killing, JOL1575, JOL1577, and reference ST strains were exposed to chicken and rabbit serum complements. The principle behind the test was to determine the sensitivity of the bacteria to complement-mediated bacterial lysis. Fresh serum contains an active complement system that lysed susceptible organisms, but heat treatment for 30 min at 56 °C inactivated the serum complements leading to decomplementation. The effect of bacterial cell lysis by serum complement killing was measured in CFU. SM was more susceptible to complement lysis by chicken serum than was ST (Fig. 1). However, SM was relatively resistant to complement killing by rabbit serum.

View Article: PubMed Central - PubMed

ABSTRACT

Salmonella serovar Montevideo (SM) is frequently associated with human Salmonella infections and causes gastrointestinal disease, cases are common particularly among individuals who come in close contact with live poultry or poultry meat products. To characterize SM disease in chickens, the pathogenic traits and tissue predilections of the disease were investigated. Dissemination of fluorescent-tagged SM (JOL1575GFP) was monitored after oral and intramuscular mock infections of specific-pathogen-free chickens. The spleen was predominantly affected by intramuscular infection while the cecum, spleen, and minimally liver were affected by oral infection. No conspicuous illness was observed in infected birds, and histopathological examination showed minimal damage of the intestinal epithelium and splenic parenchyma though SM was readily isolated from these tissues. Levels of SM internalization by primary chicken peritoneal macrophages were similar to that of Salmonella Typhimurium. SM was more sensitive to chicken than rabbit serum complement killing. Internal egg contamination of SM mock infected layers also occurred at trace levels and lasted for a week after inoculation. This study also confirmed that SM infection in chickens is sub-clinical and asymptomatic, which suggests that latent asymptomatic carriers may excrete a large number of bacteria and transmit the pathogen by contaminating water or food sources.

No MeSH data available.


Related in: MedlinePlus