Sero-epidemiological survey and risk factors associated with bovine brucellosis among slaughtered cattle in Nigeria

Bovine brucellosis is endemic in Nigeria; however, limited data exist on nationwide studies and risk factors associated with the disease. Using a cross-sectional sero-epidemiological survey, we determined the prevalence of and risk factors for brucellosis in slaughtered cattle in three geographical regions of Nigeria. Serum samples from randomly selected unvaccinated cattle slaughtered over a period of 3 years (between December 2010 and September 2013) from northern, southern and south-western Nigeria were tested for antibodies to Brucella abortus using the Rose Bengal test. Data associated with risk factors of brucellosis were analysed by Stata Version 12. In all, 8105 cattle were screened. An overall seroprevalence of 3.9% (315/8105) was recorded by the Rose Bengal test, with 3.8%, 3.4% and 4.0% from the northern, southern and south-western regions, respectively. Bivariate analysis showed that cattle screened in northern Nigeria were less likely to be seropositive for antibodies to Brucella spp. than those from south-western Nigeria (odds ratio = 0.94; 95% confidence interval: 0.73–1.22). However, logistic regression analysis revealed that breed ( p = 0.04) and sex ( p £ 0.0001) of cattle were statistically significant for seropositivity to Brucella spp. The study found that brucellosis was endemic at a low prevalence among slaughtered cattle in Nigeria, with sex and breed of cattle being significant risk factors. Considering the public health implications of brucellosis, we advocate coordinated surveillance for the disease among diverse cattle populations in Nigeria, as is carried out in most developed countries. Keywords: Bovine brucellosis, RBT, Epidemiology, Public Health, Nigeri

Bacterial Load and Antimicrobial Profile of Escherichia coli and Listeria spp. Isolates from Muscle Tissues of Slaughtered Cattle at a Major Abattoir in Ibadan, South-Western Nigeria

Meat is prone to contamination by pathogenic organisms during slaughter and processing due to unhygienic practices in Nigeria. In recent times, there has been an increase in the prevalence of antibiotic resistant foodborne pathogens due to increased drug misuse in livestock industry. We assessed the level of microbial contamination of fresh muscle tissues from cattle slaughtered in a major abattoir in Ibadan immediately after slaughter and also determined the antibiogram of Escherichia coli and Listeria spp isolates from the muscle tissues. These were done using standard plate and Bauer-Kirby disc diffusion techniques for bacteriological assay and antibiotic sensitivity testing, respectively. We found that the muscle tissues from the slaughtered cattle were highly contaminated, with the Total Aerobic (6.59±0.94 log cfu/g), coliform (6.43±0.67 log cfu/g) and Listeria (6.96±0.32 log cfu/g) counts being higher than the acceptable international standards. Isolated E. coli and Listeria spp demonstrated 100% resistance to all tested antibiotics. We thus recommend further studies to be carried out on the molecular characteristics of antibiotic resistant genes responsible for transferability of bacterial resistance among foodborne pathogens in Nigeria

Bacterial Load and Antimicrobial Profile of Escherichia coli and Listeria spp. Isolates from Muscle Tissues of Slaughtered Cattle at a Major Abattoir in Ibadan, South-Western Nigeria

Meat is prone to contamination by pathogenic organisms during slaughter and processing due to unhygienic practices in Nigeria. In recent times, there has been an increase in the prevalence of antibiotic resistant foodborne pathogens due to increased drug misuse in livestock industry. We assessed the level of microbial contamination of fresh muscle tissues from cattle slaughtered in a major abattoir in Ibadan immediately after slaughter and also determined the antibiogram of Escherichia coli and Listeria spp isolates from the muscle tissues. These were done using standard plate and Bauer-Kirby disc diffusion techniques for bacteriological assay and antibiotic sensitivity testing, respectively. We found that the muscle tissues from the slaughtered cattle were highly contaminated, with the Total Aerobic (6.59±0.94 log cfu/g), coliform (6.43±0.67 log cfu/g) and Listeria (6.96±0.32 log cfu/g) counts being higher than the acceptable international standards. Isolated E. coli and Listeria spp demonstrated 100% resistance to all tested antibiotics. We thus recommend further studies to be carried out on the molecular characteristics of antibiotic resistant genes responsible for transferability of bacterial resistance among foodborne pathogens in Nigeria

Oxytetracycline and penicillin-G residues in cattle slaughtered in south-western Nigeria: Implications for livestock disease management and public health

After the discovery of indiscriminate antibiotic use in ready-for-slaughter cattle in south-western Nigeria, 90 tissue samples from randomly selected slaughtered cattle were evaluated for oxytetracycline and penicillin-G residues using high performance liquid chromatography and the data analysed by one-way Analysis of variance (ANOVA). The findings revealed residues of oxytetracycline (kidney: 9.47 µ/kg ± 3.24 µ/kg; liver: 12.73 µ/kg ± 4.39 µ/kg; muscle: 16.17 µ/kg ± 5.52 µ/kg) and penicillin-G (kidney: 6.27 µ/kg ± 2.46 µ/kg; liver: 8.5 µ/kg ± 2.80 µ/kg; muscle: 11.67 µ/kg ± 2.94 µ/kg) in all tissues screened. Significantly high levels (oxytetracycline: F = 16.77; penicillin-G: F = 29.38) were, however, found in muscles, followed by liver and then kidney – findings confirming recent antibiotic administration to the animals before slaughter. The dietary intakes through the tissues screened were 0.024% (oxytetracycline) and 0.017% (penicillin-G) of the acceptable daily intake (ADI). Although the concentrations in the tissues screened were below the maximum residue limits despite recent administration of these antibiotics before slaughter, the lower concentrations are suggestive of the probable low dosages often administered by those involved in indiscriminate use of antibiotics. This therefore raises serious concerns for the livestock industry as well as human health, given the resultant emergence and spread of resistant strains of bacterial pathogens that could ensue from prolonged use of low dosages of antibiotics. Additionally, the lower concentrations of the daily intakes notwithstanding, the plausible exposure to these antibiotics from other food sources is a cause for concern. Since antimicrobial misuse and its consequent effects are not just a problem limited to Nigeria but also a concern in sub-Saharan Africa, the need for national and international stakeholder intervention is emphasised