Onderstepoort Journal of Veterinary Research最新文献

Fasciolosis is caused by digenean trematodes of the genus Fasciola. The principal definitive hosts are cattle, sheep and goats. Humans are infected as accidental hosts. Fasciolosis is one of the major neglected tropical diseases and is considered an emerging zoonotic infection. This study was aimed at determining the prevalence of human and domestic animal fasciolosis in selected counties in Kenya. Stool samples for Fasciola diagnosis were collected from humans and domestic animals and transported to the laboratory at Egerton University and processed using sedimentation technique and examined for the presence of eggs. A total of 272 human samples collected were all negative for Fasciola eggs. A total of 582 domestic animals (cattle (46.0%), sheep (29.9%) and goats (24.1%)) samples collected had overall prevalence of 30.9% for Fasciola infection. There was no significant differences (p0.05) between prevalence of fasciolosis and origin of the animals, sex and season. There was a significant difference (p0.05) between the prevalence of fasciolosis and domestic animals, age and body condition. The prevalence of fasciolosis was high in two irrigation schemes which favor the breeding of intermediate host snail and grazing of animals along the irrigation canals where metacercaria of Fasciola parasites could be present on the vegetation. Though human fasciolosis was not detected in this study, the presence of animal fasciolosis can pose public health risk because of its zoonotic nature. It is therefore, important to introduce measures which would assist reduce exposure of animals to Fasciola infection.

Background:  Diarrheagenic E. coli (DEC) strains are a major cause of diarrheal diseases in both developed and developing countries. Healthy asymptomatic animals may be reservoirs of zoonotic DEC, which may enter the food chain via the weak points in hygiene practices.

Aim:  We investigated the prevalence of DEC along the pig production continuum from farm-to-fork.

Methods:  A total of 417 samples were collected from specific points along the pig production system, that is, farm, transport, abattoir and food. E. coli was isolated and enumerated using Colilert. Ten isolates from each Quanti-tray were selected randomly and phenotypically identified using eosin methylene blue agar selective media. Real-time polymerase chain reaction (PCR) was used to confirm the species and to classify them into the various diarrheagenic pathotypes. Antimicrobial susceptibility was determined against a panel of 20 antibiotics using the Kirby-Bauer disk diffusion method and EUCAST guideline.

Results:  The final sample size consisted of 1044 isolates, of which 45.40% (474/1044) were DEC and 73% (762/1044) were multidrug-resistant. Enteroinvasive E. coli (EIEC) was the most predominant DEC at all the sampling sites.

Conclusion:  The presence of DEC in food animal production environments and food of animal origin could serve as reservoirs for transmitting these bacteria to humans, especially in occupationally exposed workers and via food. Adherence to good hygienic practices along the pig production continuum is essential for mitigating the risk of transmission and infection, and ensuring food safety.

Historically, the use of antibiotics was not well regulated in veterinary medicine. The emergence of antibiotic resistance (ABR) in pathogenic bacteria in human and veterinary medicine has driven the need for greater antibiotic stewardship. The preservation of certain antibiotic classes for use exclusively in humans, especially in cases of multidrug resistance, has highlighted the need for veterinarians to reduce its use and redefine dosage regimens of antibiotics to ensure efficacy and guard against the development of ABR pathogens. The minimum inhibitory concentration (MIC), the lowest concentration of an antibiotic drug that will prevent the growth of a bacterium, is recognised as a method to assist in antibiotic dosage determination. Minimum inhibitory concentrations sometimes fail to deal with first-step mutants in bacterial populations; therefore dosing regimens based solely on MIC can lead to the development of ABR. The mutant prevention concentration (MPC) is the minimum inhibitory antibiotic concentration of the most resistant first-step mutant. Mutant prevention concentration determination as a complementary and sometimes preferable alternative to MIC determination for veterinarians when managing bacterial pathogens. The results of this study focused on livestock pathogens and antibiotics used to treat them, which had a MIC value of 0.25 µg/mL for enrofloxacin against all 27 isolates of Salmonella typhimurium. The MPC values were 0.50 µg/mL, with the exception of five isolates that had MPC values of 4.00 µg/mL. The MPC test yielded 65.52% (18 isolates) Salmonella isolates with florfenicol MICs in the sensitive range, while 11 isolates were in the resistant range. Seventeen isolates (58.62%) of Pasteurella multocida had MIC values in the susceptible range and 41.38% (12 isolates) had an intermediate MIC value. Mutant prevention concentration determinations as done in this study is effective for the antibiotic treatment of bacterial infections and minimising the development of resistance. The MPC method can be used to better control to prevent the development of antibiotic drug resistance used in animals.

African swine fever virus (ASFV) causes a lethal and contagious disease of domestic pigs. In South Africa, the virus historically circulated in warthogs and ornithodorid ticks that were only found in warthog burrows in the north of the country. Regulations implemented in 1935 to prevent transfer of infected animals or products to the south initially proved effective but from 2016 there have been outbreaks of disease in the south that cannot be traced to transfer of infection from the north. From 1963 there were widespread translocations of warthogs to the south, initially from a source considered to be free of ornithodorid ticks. We undertook to determine whether sylvatic circulation of ASFV occurs in the south, including identification of potential new vectors, through testing extralimital warthogs for antibody and ticks for virus. Results of testing warthogs for antibody and other species of ticks for virus will be presented separately. Here we report finding Ornithodoros (Pavlovskyella) zumpti ticks in warthog burrows for the first time. This occurred in the Eastern Cape Province (ECP) in 2019. Since African swine fever was recognised in the ECP for the first time in 2020 and outbreaks of the disease in domestic pigs continue to occur there, priority should be given to determining the distribution range and vector potential of O. (P.) zumpti for ASFV.

Bovine tuberculosis (bTB) is a zoonotic, infectious, chronic and contagious disease, caused by Mycobacterium bovis that mainly affects cattle. This pathology has a negative impact on animals and animal products trade. Unfortunately, in Burkina Faso where agriculture and livestock sectors represent around 80% of the socio-economic activities, the real situation of the disease is not well known especially in small ruminants and swine. Thus, our study focused on both the epidemiology and the microbiological diagnosis of tuberculosis (TB) in small ruminants and pigs slaughtered at Bobo-Dioulasso abattoir. A prospective study was conducted between August 2017 and December 2017. Epidemiological data collection was performed during routine meat inspection; moreover, samples were taken and transported to the Bacteriology laboratory of Centre Muraz for microbiological analyses. This diagnosis consisted in search of Acid Fast Bacilli (AFB) using the hot Ziehl-Neelsen staining. Out of a total of 14 648 small ruminants and 2430 pigs slaughtered during the study period, 156 and 17 had lesions suggestive of bTB with prevalence of 1.07% and 0.7%, respectively. Females and those between 2 and 4 years old were mainly infected. The most affected organs were: lungs, liver, spleen and lymph nodes. Finally, microscopy revealed 43.35% (75/173) of positive cases for AFB. These results confirm the presence of bTB in small ruminants and pigs in Burkina Faso. Efforts must still be made in the fight against this zoonosis in order to limit its economic and public health impacts.

Staphylococcus species colonises humans and animals and is a major food contaminant with public health significance. Here, we assessed the occurrence of methicillin-resistant staphylococci (MRS) in the pig-production chain in Ibadan, Nigeria. Nares of 120 pigs and 10 farmers were sampled with sterile swabs whilst 54 pork samples were collected from a retail slaughterhouse. Staphylococcus species were isolated using enrichment, cefoxitin-aztreonam selective broth and Mannitol salt agar. Isolates were tested for susceptibility to cefoxitin (30 μg), oxacillin (1 μg) and vancomycin (30 μg). Methicillin-resistant staphylococci isolates were characterised using conventional biochemical tests. From 184 samples, 364 staphylococcal isolates were obtained. Amongst the 54 pork samples, 44.0% were contaminated with Staphylococcus species. Overall, 9 (2.5%) MRS were obtained and presumptively identified as Staphylococcus xylosus (n = 3), Staphylococcus sciuri (n = 3), Staphylococcus warneri (n = 2) and Staphylococcus cohnii (n = 1). There was no relationship between the prevalence of MRS between pigs and pig handlers in the farms, but Farm 2 had the highest frequency of 66.7% (p 0.05). Piglets had the highest prevalence of 66.7% (p 0.05) whilst MRS was absent in workers and pork samples. This study raises concerns about the cross-contamination of staphylococci in the food chain. Constant surveillance is imperative to ensure food safety.