Analysis of Retrospective Laboratory Data on the Burden of Bacterial Pathogens Isolated at the National Veterinary Research Institute Nigeria, 2018-2021.

Farm animals harbour bacterial pathogens, which are often viewed as important indicators of animal health and determinants of food safety. To better understand the prevalence and inform treatment, we audited laboratory data at the Bacteriology Laboratory of the NVRI from 2018-2021. Antibiotics were classified into seven basic classes: quinolones, tetracyclines, beta-lactams, aminoglycosides, macrolides, nitrofuran, and cephalosporins. Trends were analysed using a generalised linear model with a log link function for the Poisson distribution, comparing proportions between years with an offset to account for the variability in the total number of organisms per year. Avian (73.18%) samples were higher than any other sample. The major isolates identified were Escherichia. coli, Salmonella spp., Klebsiella spp., Staphylococcus spp., Proteus spp., and Pseudomonas spp. We found that antimicrobial resistance to baseline antibiotics increased over the years. Of particular concern was the increasing resistance of Klebsiella spp. to cephalosporins, an important second-generation antibiotic. This finding underscores the importance of farm animals as reservoirs of pathogens harbouring antimicrobial resistance. Effective biosecurity, surveillance, and frugal use of antibiotics in farms are needed because the health of humans and animals is intricately connected.

Chitosan/alginate microparticles for the oral delivery of fowl typhoid vaccine: Innate and acquired immunity.

Oral fowl typhoid (FT) vaccine is necessary for improved flock vaccinations and economic growth. This study was undertaken to evaluate the immune responses of birds given oral fowl typhoid vaccine coated with chitosan/alginate microparticles and comparing it with the conventional subcutaneous route of administration. Preliminary studies were done to evaluate the particle size, encapsulation efficiency and agglutination. Sixty day-old chicks were divided into three groups of twenty birds each. This comprised a negative control group NEG 451 (non-vaccinated and non-challenged used as control for cytokine quantification), SC 634 (live 9R vaccine by the injection route) and OCV 567 (live 9R vaccine coated with chitosan/alginate microparticles). Vaccination was done at 10 weeks and 14 weeks of age followed by challenge at 16 weeks of age. IgG was measured using ELISA. mRNA fold expression of IFN-γ in spleen was calculated using qRT-PCR. Particle sizes ranged between 0.55 µm and 10 µm. Encapsulation efficiency was above 60%. ELISA showed E-values of 0.10 ±â€¯0.14, 0.07 ±â€¯0.01 and 0.02 ±â€¯0.01 for OCV 567, SC 634 and NEG 451 respectively after primary vaccination. Also E-values were 0.25 ±â€¯0.16, 0.19 ±â€¯0.04 and 0.0008 ±â€¯0.005 for SC 634, OCV 567 and NEG451 respectively after boost vaccination. The expression of IFN-γin spleen using 2-ΔΔ CT calculation was upregulated with values of 1.97 and 0.75 for OCV 567 and SC 634 respectively. After challenge with the 85-kb virulence plasmid SG9, there was 100% protection of the birds in both OCV 567 and SC 634 groups with no mortality. In conclusion, there was no significant difference at p < 0.05 of the means ±â€¯SD in immune responses between the oral fowl typhoid vaccine coated with chitosan/alginate microparticles and the subcutaneous route of administration. However, it is noteworthy to mention that the protective efficacy of the oral route is due to the chitosan/alginate biopolymers which coated the vaccine preventing destruction in the gastrointestinal tract.

Phosphine poisoning in free-range local chickens: a case report.

Phosphine poisoning is rarely reported in poultry, and its diagnosis is a great challenge for veterinary toxicologists and pathologists. A case of phosphine toxicosis in local, free range chickens is reported. Fourteen dead chickens (age ≥6 months old) were presented to the veterinary clinic for necropsy. The history revealed that the chickens were normally fed with guinea corn grains, but were suspected to have been fed boiled rice laced with poison. The clinical signs observed were ruffled feathers, somnolence, anorexia and high mortality. The disease ran a 2-day course with mortality pattern of four chickens the first day, six overnight and 14 the following day. Necropsy findings showed generalized vascular congestion and haemorrhage in the lungs and visceral organs, with the crop and gizzard filled with guinea corn and rice grains and greenish-yellow faecal material in the intestinal lumen. The presence of widespread congestion and petechial haemorrhages on visceral organs with the microscopic pulmonary congestion, and diffuse intraparabronchial presence of air sac macrophages, strongly suggested an acute toxic cause of death. Chemical tests on the crop contents of the dead chickens were positive for phosphine gas. This report will contribute to a better understanding of the clinical signs and lesions presented in cases of acute phosphide rodenticide exposure in domestic chickens, with a brief review of the forensic literature.