An outbreak of haemorrhagic septicaemia (septicaemic pasteurellosis) in cattle in Zimbabwe

Heavy Rainfall, Sewer Overflows, and Salmonellosis in Black Skimmers (Rynchops niger)

Extreme weather events, particularly heavy rainfall, are occurring at greater frequency with climate change. Although adverse human health effects from heavy rainfall are often publicized, impacts to free-ranging wildlife populations are less well known. We first summarize documented associations of heavy rainfall on wildlife health. We then report a novel investigation of a salmonellosis outbreak in a colony of black skimmers (Rynchops niger) in Florida, USA. During June-September 2016, heavy rainfall resulted in the discharge of millions of gallons of untreated wastewater into the Tampa Bay system, contaminating the water body, where adult skimmers foraged. At least 48 fledglings died, comprising 39% of the colony's nesting season's offspring. Of eight examined deceased birds from the colony, six had a systemic salmonellosis infection. Isolates were identified as Salmonella enterica serotype Typhimurium. Their pulsed-field gel electrophoresis patterns were identical to each other and matched those from several human Salmonella sp. infections. Differences among whole-genome sequences were negligible. These findings and the outbreak's epidemic curve suggest propagated transmission occurred within the colony. A multidisciplinary and One Health approach is recommended to mitigate any adverse effects of climate change-driven stochastic events, especially when they place already imperiled wildlife at further risk.

Localization of Pasteurella multocida antigens in the brains of pigs naturally infected with Pasteurellosis revealing a newer aspect of pathogenesis

Pasteurella multocida is an economically important respiratory pathogen of pigs confronting swine industry worldwide. Despite extensive research over the decades, its pathogenesis is still poorly understood. Recent reports have demonstrated the nervous system affection as a newer aspect of pathogenesis by Pasteurella multocida type B:2 in Haemorrhagic Septicemia, but there are no reports of the involvement of nervous system by P. multocida in pigs. Therefore, the study was aimed to explore the neurovirulence of Pasteurella multocida in naturally infected pigs. A total of 15 brains were collected from the natural cases of pig mortality suggestive of Pasteurellosis. Grossly, the leptomeninges were markedly congested and brains were oedematously swollen. Histologically, there was moderate to severe fibrinohaemorrhagic and mononuclear cells exudates present in the leptomeningeal tissue and cerebrospinal spaces. Similar vascular inflammatory lesions (perivascular and perineuronal) along with gliosis, neuronal degeneration and necrosis were noted in various subanatomical sites of the brain (cerebrum, cerebellum, brainstem and spinal cord). The culture and biochemical tests showed the presence of P. multocida within the brain tissue. P. multocida type specific antibody staining in the brain tissues revealed intense distribution of antigens in the inflammatory exudates of meningeal vessels, neurons, glial cells and endothelial cells of the blood vessels contributing its association with neuropathological lesions. Pasteurella multocida specific PCR amplification of capsular polysaccharide gene yielded 460 bp and multiplex PCR showed the involvement of capsular serogroups A &D. All the isolates showed the presence of 10 genes for virulence factors. The disease confirmation of both serotypes was proven by Koch's postulates using Swiss albino mice. Further, histopathological brain lesions along with the immunohistochemical detection of bacterial antigens were corroborated with natural cases of P. multocida as described above. To the best of our knowledge, we first time report the neuroinvasion of P. multocida in naturally infected pigs.

Clinico-pathology, hematology, and biochemistry responses toward Pasteurella multocida Type B: 2 via oral and subcutaneous route of infections

Background:

Pasteurella multocida a Gram-negative bacterium has been identified as the causative agent of many economically important diseases in a wide range of hosts. Hemorrhagic septicemia is a disease caused by P. multocida serotype B:2 and E:2. The organism causes acute, a highly fatal septicemic disease with high morbidity and mortality in cattle and more susceptible in buffaloes. Therefore, the aim of this study was to investigate the clinical signs, blood parameters, post mortem and histopathology changes caused by P. multocida Type B:2 infections initiated through the oral and subcutaneous routes.

Methods:

Nine buffalo heifers were divided equally into 3 treatment groups. Group 1 was inoculated orally with 10 ml of phosphate buffer saline; Groups 2 and 3 were inoculated with 10 ml of 10¹² colony forming unit of P. multocida Type B:2 subcutaneously and orally respectively.

Results:

There was a significant difference (p<0.05) in temperature between the subcutaneous and the control group. The results revealed significant differences (p<0.05) in erythrocytes, hemoglobin, packed cell volume, leukocytes, monocytes, and A: G ratio between the subcutaneous and the control group. Furthermore, there were significant differences (p<0.05) in leukocytes, band neutrophils, segmented neutrophils, lymphocytes, eosinophils, basophils, thrombocytes, plasma protein, icterus index, gamma glutamyl tranferase and A: G ratio between the oral and the control group. The post mortem lesions of the subcutaneous group buffaloes showed generalized hyperemia, congestion and hemorrhage of the immune organs, gastro-intestinal tract organs and vital organs. The oral group buffaloes showed mild lesions in the lung and liver. Histologically, there were significant differences (p<0.05) in hemorrhage and congestion; necrosis and degeneration; inflammatory cells infiltration; and edema in between the groups.

Conclusion:

This study was a proof that oral route infection of P. multocida Type B:2 can be used to stimulate host cell responses where oral vaccine through feed can be developed in the near future.

Diagnostic and typing options for investigating diseases associated with Pasteurella multocida

Pasteurella multocida is responsible for major animal diseases of economic significance in both developed and developing countries whereas human infections related to this bacterium are infrequent. Significantly, development of a carrier status or latent infections plays a critical role in the epidemiology of these diseases. Aiming at increased knowledge of these infections, we examine potential diagnostic and selected typing systems for investigating diseases caused by P. multocida. Detection of P. multocida from clinical specimen by; (i) isolation and identification, (ii) polymerase chain reaction (PCR), iii) specific hybridisation probes, (iv) serological tests and (v) other alternative methods is critically evaluated. These detection systems provide a wide spectrum of options for rapid diagnosis and for detecting and understanding of latent infections in herd/flock health control programmes, though PCR methods for detecting P. multocida in clinical specimen appear increasingly preferred. For establishing the clonality of outbreak strains, we select to discuss macromolecular profiling, serotyping, biotyping, restriction enzyme analysis, ribotyping and multiplex PCR typing. Although P. multocida infections can be rapidly diagnosed with molecular and serological tests, isolation and accurate species identification are central to epidemiological tracing of outbreak strains. Our review brings together comprehensive and essential information that may be adapted for confirming diagnosis and determining the molecular epidemiology of diseases associated with P. multocida.

Pasteurella multocida Sepsis and Meningitis in 2-Month-Old Twin Infants after Household Exposure to a Slaughtered Sheep

This article outlines 2 cases of Pasteurella multocida sepsis and meningitis in 2-month-old twins after their father was exposed to a sheep during a sacrifice celebration at home. These cases emphasize the necessity of respecting basic hygiene rules and the danger involved in animal sacrifice without suitable professional structure.

Outbreak of Fowl Cholera in Baikal Teals in Korea

Fowl cholera (FC) caused by Pasteurella multocida was diagnosed in waterfowl, Baikal teals (Anas formosa), submitted to the National Veterinary Research and Quarantine in Korea. The total number of mortalities was 13,228 out of approximately 100,000 birds that wintered in Cheonsoo Bay, the most important habitat area of Baikal teals in the world. Clinical signs were detected in only a few birds because of sudden death. Grossly, the dead Baikal teals had lesions consistent with FC, including multifocal necrotic foci in the liver with enlargement, petechial or ecchymotic hemorrhages on the heart, and mucoid exudates in the duodenal mucosa. Microscopically, there were hepatocytic necrosis with bacterial colonization, hemorrhage and necrosis in the myocardium, and hemorrhagic enteritis. Pasteurella multocida was isolated from the liver and the heart of all birds examined, and the isolate (P-627) was the serotype 1 X 12 X 13 by the agar gel immunodiffusion test. In order to estimate the virulence of P-627, 5-wk-old commercial ducks were exposed intramuscularly or intratracheally to the bacterium. On the basis of mortality rate, the isolate, P-627, was found to be highly virulent. This is the first report of an outbreak of FC in Baikal teals in Korea.

Phenotypic characterization of Zimbabwean isolates of Pasteurella multocida

The phenotypic characteristics of 60 Zimbabwean isolates of Pasteurella multocida sensu stricto, from disease syndromes in different host species were studied. A number of representative strains were also serotyped. Consistent results were obtained in the tests for; catalase, oxidase, urease, indole, acid in glucose, inositol, salicin and sucrose. There was no obvious relationship between serotype, host or disease and the pattern of utilization of certain substrates by an isolate. This has been discussed in the context of recent proposals to reclassify Pasteurella and P. multocida on genotypic and phenotypic studies. It is suggested that notwithstanding the relevance of genetic studies in circumscribing P. multocida, the phenotype and disease significance of the taxon should not be ignored. A case of bronchitis in a dog which was simultaneously colonized by three different strains of Pasteurella is described. Also septicaemic pasteurellosis in a Nile crocodile (Crocodylus niloticus) is reported and for the first time prevalence of various serotypes in pasteurellosis of animals in Zimbabwe.