Veterinary Research Forum

Abstract Pasteurella multocida and Mannheimia haemolytica are significant bacteria of respiratory tract infections in cattle. Identifying whether these bacteria are commensal or pathogenic is crucial for understanding their role in predisposing calves to respiratory tract infections. This study aimed to determine the prevalence and pathogenic characteristics of P. multocida and M. haemolytica in nasal swab samples of clinically healthy calves in Konya, Turkey, and to assess antibiotic resistance profiles. Using conventional culture methods, 5 samples (1.67%) from 4 different farms were positive for P. multocida and 3 samples (1%) were positive for M. haemolytica. PCR of nasal swab samples yielded P. multocida positivity in 17 (5.67%) samples and M. haemolytica positivity in 13 (4.33%), including all culture-positive samples. While all P. multocida isolates were atypical for the capsule, 18% of the PCR-positive samples were L2, 70% L3A, and 12% L8 serotypes. The ompA, omp87, hghA, and tbpA genes were the most prevalent, while the presence of other virulence genes varied. High rates of ampicillin/cloxacillin (100%) and streptomycin (80%) resistance were observed among the isolates. The rates of serotypes A1 and A6 in M. haemolytica PCR-positive samples were 53.85% and 46.15%, respectively. The ssa-1 gene was detected in 33.33% of the isolates. Moderate resistance to trimethoprim/sulfamethoxazole, streptomycin, and neomycin (66.67%) was recorded. The findings revealed the presence of P. multocida and M. haemolytica with various virulence characteristics and antimicrobial resistance profiles in the nasal microbiota of healthy calves, providing novel insights that could inform improved herd management, disease control, and treatment strategies.

Abstract An increase in morbidity during times of relatively high functional load on the body such as during pregnancy, confirms the role of metabolic overload in the occurrence of metabolic failures. It is better to take preventive measures such as adjusting metabolic regulation mechanisms in light of the ideal dietary composition. However, this direction is constrained by the lack of information about neurohumoral regulation. The goal of the present study was to learn more about the dynamics of changes in insulin and glucose levels in pregnant cow’s blood. Research on the levels of glucose and insulin in lactating cows demonstrated that ruminants had distinct characteristics in the metabolism of carbohydrates, most notably a lessened reliance of blood glucose on insulin levels. A rise in blood glucose and insulin levels was observed as the gestational stage increased during the third trimester of pregnancy. The intensity of this insulin tolerance was contingent upon the level of productivity and glucose levels during the preceding stages of gestation.

Abstract The present study was conducted to investigate the detection and identification of Cryptosporidium species via molecular techniques and evaluate the serum concentrations of inflammatory factors in Cryptosporidium species. The fecal samples (n = 256) were collected from pre-weaned (≤ 2.00 months) calves and the positive samples were identified utilizing Ziehl-Neelsen staining. Nested species-specific multiplex PCR (nssm-PCR) and restriction fragment length polymorphism (RFLP) were used to identify the species and sub-species. The serum concentrations of IL-1β, IL-6, IL-12, TNF-α, and IFN-γ were also assessed. The results revealed that 10.54% of samples were positive. The results of Nested-PCR showed that 92.59% of the samples were positive for C. parvum while 7.41% were positive for C. andersoni. The results of RFLP confirmed 92.59% of the samples for C. parvum, 3.70% for C. muris / C. andersoni, and 3.70% for C. muris. The serum concentrations of IL-1β, IL-6, IL-12, TNF-α, and IFN-γ were significantly higher in the infected calves compared to those in healthy calves. However, the serum concentration of IFN-γ was significantly higher in the calves infected with C. parvum while the serum concentrations of TNF-α and IL-6 were significantly higher in those infected with C. andersoni. In conclusion, C. parvum was prevalent in the region and the calves demonstrated inflammatory responses to Cryptosporidium species.

Abstract An 8-day-old newborn female twin Holstein calves with a history of weakness, anorexia, emaciation and convulsion were presented to Tabriz University Veterinary Teaching Hospital. On admission, the calves were febrile and recumbent. Physical examination revealed many ticks from the external body surface of the animals, right and left prescapular lymphadenopathy, severe opisthotonos, nystagmus, pedaling, blindness, hyperpnea and hypersthenia. Buccal and vaginal mucous were pale and no other physical abnormalities were diagnosed. Fecal flotation, complete blood count, bone marrow aspiration, cerebrospinal fluid (CSF) analysis, necropsy and histopathological examination were performed. Fecal flotation showed no helminth eggs or coccidial oocysts. On blood smears obtained from the earlap, >70 percent of erythrocytes were infected with piroplasms organisms and schizonts were obvious in smears of lymphocytes lymph node. Blood count revealed a lymphopenia, poikilocytosis, anisocytosis and non-regenerative anemia (packed cell volume; mean, 16%). Histopathological examination revealed Arthus reaction through the walls of cerebral blood vessels, which resulted in local necrosis of the brain. Analysis of CSF showed no abnormality in appearance or biochemical and cell counts. Although the calves were treated with a single intramuscular injection of buparvaquone and oxytetracycline once daily they did not respond to the treatment and died. In conclusion, the present cases showed a rare cerebral form of theileriosis by vertical transmission that confirmed by the presence of piroplasms on blood films and multinuclear schizonts on lymph node aspiration smears, gross and histopathological examinations and unsuccessful treatment in a newborn twin Holstein calves.