|PALERME, JEAN-SEBASTIAN - North Carolina State University|
|PAN, POCHING - North Carolina State University|
|PARSONS, CAMERON - North Carolina State University|
|KATHARIOU, SOPHIA - North Carolina State University|
|JACOB, MEGAN - North Carolina State University|
Submitted to: Journal of Veterinary Diagnostic Investigation
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 1/11/2016
Publication Date: 8/30/2016
Citation: Palerme, J-S., Pan, P.C., Parsons, C.T., Kathariou, S., Ward, T.J., Jacob, M.E. 2016. Isolation and characterization of atypical Listeria monocytogenes associated with a canine urinary tract infection. Journal of Veterinary Diagnostic Investigation. 28(5):604-607. doi: 10.117/1040638716661381.
Interpretive Summary: Listeria monocytogenes is a food-borne bacterium that can cause serious illness in humans and other animals (listeriosis). The prevalence of different strains of this pathogen has been characterized in food, food processing environments, and clinical cases of human listeriosis. However, the distribution and diversity of L. monocytogenes strains among non-human animals is less well understood. In this study, a rare case of listeriosis in an immunocompromised dog was documented and compared to strains from a wide variety of human and non-human infections. In addition, the ability of this strain to cause disease was assessed. The L. monocytogenes strain was identified as having a genetic type that is very rare among human and food-associated isolates, and which has not previously been observed among isolates from non-human animals. Although this isolate demonstrated relatively weak virulence potential, the only other isolate with this genetic type was responsible for a case of sporadic listeriosis in a human and was isolated from both the blood and synovial fluid of the infected patient. This is the first reported case of L. monocytogenes serotype 1/2a in a dog, which will be of interest to veterinary medicine as well as scientists studying mechanisms of pathogenicity in Listeria monocytogenes.
Technical Abstract: Listeria monocytogenes, a well-described cause of encephalitis and abortion in ruminants and of food-borne illness in humans, is rarely associated with disease in companion animals. A case of urinary tract infection associated with an atypical, weakly hemolytic L. monocytogenes strain is described in a diabetic dog. The serotype of the L. monocytogenes isolate was determined to be 1/2a (3a), with the multilocus genotyping pattern 2.72_1/2a. A nucleotide substitution (Gly145Asp) was detected at residue 145 in the promoter prfA region. This residue is within the critical helix-turn-helix motif of PrfA. The source of the L. monocytogenes strain remains unknown, and the dog recovered after a 4-week course of cephalexin (30 mg/kg orally twice daily).