Isolation and characterization of Leptospira interrogans serovar Copenhageni from a dog from Saint Kitts.

Introduction. Leptospirosis is a zoonotic bacterial disease of global distribution affecting humans and animals. The initial phase of leptospirosis resembles many other febrile illness and due to its broad and biphasic clinical manifestations, selection and implementation of appropriate diagnostic tests can be challenging. Case presentation. This report describes a case investigation of a 14 weeks old male, orphan puppy, presented with generalised jaundice, anemia, weakness, and anorexia. Clinical abnormalities included the evidence of renal and hepatic failure. Antemortem and postmortem diagnostic investigations were conducted to identify the cause of illness. PCR testing and culture of blood was positive for Leptospira sp. Necropsy followed by histopathology evaluation revealed lesions compatible with liver and kidney damage consisting of marked diffuse hepatocellular dissociation, acute renal tubular necrosis, and mild interstitial nephritis. Conclusion. Multiple diagnostic techniques including bacterial isolation confirmed Leptospira infection in this puppy. Whole genome sequencing and analysis identified the Leptospira sp. isolated from this puppy as Leptospira interrogans serovar Copenhageni. To our knowledge, this case report describes the first isolation of Leptospira from Saint Kitts. This case highlights the usefulness of including multiple diagnostic tests for the diagnosis and epidemiological investigation of Leptospira infection. Accurate diagnosis followed by timely intervention can prevent case fatality and mortality in infected patients.

Expression of a truncated Pasteurella multocida toxin antigen in Bordetella bronchiseptica.

Mild or subclinical respiratory infections caused by Bordetella bronchiseptica are widespread in pigs despite multiple control efforts. Infection with virulent B. bronchiseptica strains is a common risk factor in the establishment of toxin-producing strains of Pasteurella multocida in the nasal cavity of pigs leading to the disease, atrophic rhinitis (AR). This study was designed to explore the possibility of expressing a protective epitope of P. multocida toxin (PMT) in B. bronchiseptica to create single-component mucosal vaccine to control atrophic rhinitis in pigs. To achieve this, a P. multocida toxin fragment (PMTCE), that was non-toxic and protective against lethal challenge in mice, was cloned into a broad-host-range plasmid, PBBR1MCS2, and introduced into B. bronchiseptica by electroporation. The Pasteurella gene construct was placed under the regulatory control of a promoter region that was separately isolated from B. bronchiseptica and appears to be part of the heat shock protein gene family. B. bronchiseptica harboring the plasmid under antibiotic selection expressed the 80kDa PMTCE as determined by PAGE and Western blot with a PMT-specific monoclonal antibody. When introduced into the respiratory tracts of mice, B. bronchiseptica harboring the plasmid construct was reisolated in declining numbers for 72h post-inoculation. Antibody responses (IgM, IgA and IgG) to B. bronchiseptica were detected in serum and respiratory lavage, but PMTCE-specific antibodies were not detected. While further refinements of PMT expression in B. bronchiseptica are necessary, this study provides a basis for the development of a single-component, live-attenuated vaccine against atrophic rhinitis.