Clinical Investigation of the Pathogenicity of Pasteurella multocida Isolated from Cattle in Egypt Regarding its Effect on Hematological, Biochemical, and Oxidant-Antioxidant Biomarkers as well as Proinflammatory Cytokines and Acute Phase Proteins

This study aimed to screen Pasteurella multocida for different virulence genes, antimicrobial resistance profiles, and to examine its effect on hematological, biochemical, oxidant-antioxidant biomarkers, proinflammatory cytokines, and acute-phase proteins in infected cattle. A total of 70 cattle from the Monufia and Qalyubia governorates included 30 animals suffering from respiratory manifestations and 40 cases were apparently healthy. P.multocida was detected in diseased animals and represented 30/70(42.9%) as confirmed by PCR. Capsular typing confirmed that types A and D represented 10/30(33.3%) and 20/30(66.7%) of the isolates, respectively. The distribution of ompA, sodC, toxA genes encoding outer membrane protein A, superoxide dismutase, and dermonecrotic toxin, respectively, were detected at frequencies of 28/30(93.3%), 22/30(73.3%), and 5/30(16.7%). The most effective antimicrobials were ciprofloxacin, amoxicillin/clavulanic acid, chloramphenicol, and azithromycin. P.multocida isolates were categorized to 14 groups after their antimicrobial resistance profiles, the antimicrobial resistance indices ranged from 0.0 to 1.0. Hematological changes included a significant reduction in RBCs, Hb, PCV, MCV, MCH, MCHC, and lymphocytes, in addition to significant leukocytosis, granulocytosis, and monocytosis. Biochemical alterations included a significant decrease in serum albumin, albumin/globulin ratio, sodium, calcium, phosphorus, chloride, iron, and TIBC concentrations with a significant increase in serum ALT, AST, TP, globulin, creatinine, urea, and potassium. Alterations in oxidant-antioxidative status included a significant increase in serum MDA and NO with a significant decrease in serum TAC, GSH, and SOD. An exaggerated response of proinflammatory cytokines (IL-1, IL-6, TNF-α) and acute-phase proteins (SAA, Hp) was observed. Hence, this work may assist in clarifying the pathogenesis of the disease and thus inform efficient diagnosis and treatment.