In recent years, Shewanella putrefaciens, commonly known as a halophilic bacteria, has been associated with serious health disorders in freshwater fish. Therefore, it has been described as a new aetiological agent of the disease, named shewanellosis. S. putrefaciens is a heterogeneous group of microorganisms, belonging to the Alteromonadaceae family. Based on different criteria, three biovars and biogroups as well as four genomic groups have been distinguished. The first infections of S. putrefaciens in fish were reported in rabbitfish (Siganus rivulatus) and European sea bass (Dicentrarchus labrax L.). Outbreaks in farmed fish were reported in Poland for the first time in 2004. The disease causes skin disorders and haemorrhages in internal organs. It should be noted that S. putrefaciens could also be associated with different infections in humans, such as skin and tissue infections, bacteraemia, otitis. Investigations on pathogenic mechanisms of S. putrefaciens infections are very limited. Enzymatic activity, cytotoxin secretion, adhesion ability, lipopolysaccharide (LPS), and the presence of siderophores are potential virulence factors of S. putrefaciens. Antimicrobial resistance of S. putrefaciens is different and depends on the isolates. In general, these bacteria are sensitive to antimicrobial drugs commonly used in aquaculture.

Objective: This study was carried out to assess the pathogenicity of local isolates of Mycoplasma ovipneumoniae and M. arginini in West African dwarf goats (kids) in Nigeria. Materials and methods: A total of 22 goats aged less than 1-year were purchased from markets. The goats were divided into six groups comprising of four experimental groups (EG; 4 in each) and two control groups (CG; 3 in each). The goats were fed ad libitum with standard diets and safe water. Groups EG1 and EG2 were infected with M. ovipneumoniae through trans-tracheal (TT) and intravenous (IV) routes, respectively, while those in groups EG3 and EG4 were infected with M. arginini through the same routes. Goats in groups CG1 and CG2 were inoculated with sterile Mycoplasma broth through TT and IV routes, respectively. In all cases, the amount of bacteria inoculated was 1.5x108 cells/mL. After the onset of the disease in goats, re-isolation of Mycoplasma was performed by culturing on mycoplasma agar supplemented with mycoplasma supplement G. The goats were monitored for 14 days post-infection (PI) to observe respiratory signs and mortality. Post-mortem (PM) examination was performed on each animal that died, while one surviving goat from each of the groups was sacrificed at 14 days PI for PM. After PM, histopathology was performed to observe the changes in tissues. Results: Cough and nasal discharges were observed in all the experimentally infected goats seven days PI. Mortalities were recorded in goats in EG1 (two goats), EG2 (one goats), EG3 (two goats) and EG4 (one goat). At PM, pneumonic lesions were observed in the lungs of all the experimentally infected goats. Conclusion: This study provides evidence that the local isolates of M. ovipneumoniae and M. arginini strains are pathogenic for goats in Nigeria. [J Adv Vet Anim Res 2016; 3(3.000): 242-251]