• 1

    Carlson SAStoffregen WC, Bolìn SR. Abomasitis due to multiple antibiotic resistant Salmonella enterica serotype Typhimurium phagetype DT104. Vet Microbiol 2002;85:233240.

    • Search Google Scholar
    • Export Citation
  • 2

    Wall PGMorgan DLamden K, et al. A case control study of infection with an epidemic strain of multiresistant Salmonella typhimurium DT104 in England and Wales. Commun Dis Rep CDR Rev 1994;4:R130R135.

    • Search Google Scholar
    • Export Citation
  • 3

    Boyd DPeters GCloeckaert A, et al. Complete nucleotide sequence of a 43-kilobase genomic island associated with the multidrug resistance region of Salmonella enterica serovar Typhimurium DT104 and its identification in phage type DT120 and serovar Agona. J Bacteriol 2001;183:57255732.

    • Search Google Scholar
    • Export Citation
  • 4

    Briggs CEFratamico PM. Molecular characterization of an antibiotic resistance gene cluster of Salmonella typhimurium DTI04. Antimicrob Agents Chemother 1999;43:846849.

    • Search Google Scholar
    • Export Citation
  • 5

    Rasmussen MACarlson SAFranklin SK, et al. Exposure to rumen protozoa leads to enhancement of invasion and pathogenicity for multiple antibiotic resistant Salmonella bearing SGI-1. Infect Immun 2005;73:46684675.

    • Search Google Scholar
    • Export Citation
  • 6

    Carlson SASharma VKMcCuddin ZP, et al. Involvement of a Salmonella genomic island 1 gene in the rumen protozoan-mediated enhancement of invasion for multiple-antibiotic-resistant Salmonella enterica serovar Typhimurium. Infect Immun 2007;75:792800.

    • Search Google Scholar
    • Export Citation
  • 7

    McCuddin ZPCarlson SASharma VK. Experimental reproduction of bovine Salmonella encephalopathy using a norepinephrine-based stress model. Vet J 2008;175:8288.

    • Search Google Scholar
    • Export Citation
  • 8

    Carlson SABolton LFBriggs CE, et al. Detection of Salmonella typhimurium DT104 using multiplex and fluorogenic PCR. Mol Cell Probes 1999;13:213222.

    • Search Google Scholar
    • Export Citation
  • 9

    Carlson SMeyerholz DStabel T, et al. Secretion of a putative cytotoxin in multiple antibiotic resistant Salmonella enterica serotype Typhimurium phagetype DT104. Microb Pathog 2002;31:201204.

    • Search Google Scholar
    • Export Citation
  • 10

    Wu MTCarlson SAMeyerholz DK. Cytopathic effects observed upon expression of a repressed collagenase gene present in Salmonella and related pathogens: mimicry of a cytotoxin from multiple antibiotic-resistant Salmonella enterica serotype Typhimurium phagetype DT104. Microb Pathog 2002;32:279287.

    • Search Google Scholar
    • Export Citation
  • 11

    Carlson SAMcCuddin ZPWu MT, et al. SlyA partially regulates the collagenase-mediated cytopathic phenotype specific for multiresistant Salmonella. Microb Pathog 2005;38:181187.

    • Search Google Scholar
    • Export Citation
  • 12

    Pabbaraju KMiller WSanderson K. Distribution of intervening sequences in the genes for 23S rRNA and rRNA fragmentation among strains of Salmonella Reference Collection B (SARB) and SARC sets. J Bacteriol 2000;182:19231929.

    • Search Google Scholar
    • Export Citation
  • 13

    Frana TSCarlson SAGriffith RW. Relative distribution and conservation of genes encoding aminoglycoside-modifying enzymes in Salmonella enterica serotype typhimurium phage type DT104. Appl Environ Microbiol 2001;67:445448.

    • Search Google Scholar
    • Export Citation
  • 14

    Guerra BSoto SHelmuth R, et al. Characterization of a self-transferable plasmid from Salmonella enterica serotype typhimurium clinical isolates carrying two integron-borne gene cassettes together with virulence and drug resistance genes. Antimicrob Agents Chemother 2002;46:29772981.

    • Search Google Scholar
    • Export Citation

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Evaluation of the pathogenicity and virulence of three strains of Salmonella organisms in calves and pigs

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  • 1 Department of Biomedical Sciences, College of Veterinary Medicine, Iowa State University Ames, IA 50011.

Abstract

Objective—To assess in pigs the pathogenicity and virulence of 3 strains of Salmonella spp capable of causing atypical salmonellosis in cattle.

Animals—36 Holstein calves and 72 pigs experimentally infected with Salmonella spp

Procedures—Representative Salmonella strains associated with 3 new disease phenotypes (protozoa-mediated hypervirulence, multisystemic cytopathicity, and encephalopathy) that have been characterized in cattle during the past 10 years were orally inoculated into pigs. Clinical manifestations were compared with those observed in cattle. Samples were collected from various tissues, and the presence of Salmonella organisms was assessed qualitatively and quantitatively by use of Salmonella-selective media

Results—Of the 3 unique Salmonella disease phenotypes observed in cattle, only protozoa-mediated hypervirulence was observed in pigs. Hypervirulence was related to a more rapid onset of disease and higher pathogen burden in pigs than in cattle. This phenotype was observed in pigs inoculated with multiresistant Salmonella enterica serotypes Typhimurium or Choleraesuis bearing the Salmonella genomic island 1 (SGI1) integron.

Conclusions and Clinical RelevanceSalmonella hypervirulence was identified in pigs noculated with SGI1-bearing strains exposed to free-living protozoa. Additionally, an SGI1-bearing strain of Salmonella Choleraesuis was detected that resulted in augmented virulence in pigs. Therefore, it appeared that protozoa-associated salmonellosis was analogous in pigs and cattle. Salmonella-mediated encephalopathy and multisystemic cytopathicity did not appear to be relevant diseases in pigs. (Am J Vet Res 2010;71:1170-1177)

Abstract

Objective—To assess in pigs the pathogenicity and virulence of 3 strains of Salmonella spp capable of causing atypical salmonellosis in cattle.

Animals—36 Holstein calves and 72 pigs experimentally infected with Salmonella spp

Procedures—Representative Salmonella strains associated with 3 new disease phenotypes (protozoa-mediated hypervirulence, multisystemic cytopathicity, and encephalopathy) that have been characterized in cattle during the past 10 years were orally inoculated into pigs. Clinical manifestations were compared with those observed in cattle. Samples were collected from various tissues, and the presence of Salmonella organisms was assessed qualitatively and quantitatively by use of Salmonella-selective media

Results—Of the 3 unique Salmonella disease phenotypes observed in cattle, only protozoa-mediated hypervirulence was observed in pigs. Hypervirulence was related to a more rapid onset of disease and higher pathogen burden in pigs than in cattle. This phenotype was observed in pigs inoculated with multiresistant Salmonella enterica serotypes Typhimurium or Choleraesuis bearing the Salmonella genomic island 1 (SGI1) integron.

Conclusions and Clinical RelevanceSalmonella hypervirulence was identified in pigs noculated with SGI1-bearing strains exposed to free-living protozoa. Additionally, an SGI1-bearing strain of Salmonella Choleraesuis was detected that resulted in augmented virulence in pigs. Therefore, it appeared that protozoa-associated salmonellosis was analogous in pigs and cattle. Salmonella-mediated encephalopathy and multisystemic cytopathicity did not appear to be relevant diseases in pigs. (Am J Vet Res 2010;71:1170-1177)

Contributor Notes

Dr. Barnhill's present address is National Animal Disease Center, 2300 Dayton Rd, Ames, IA 50010.

Supported in part by the National Pork Board on behalf of the Iowa Pork Producers Association.

The authors thank Diane McDonald for technical assistance.

Address correspondence to Dr. Carlson (stevec@iastate.edu).