Phenotypic detection and genotyping of Clostridium perfringens associated with enterotoxemia in sheep in the Qassim Region of Saudi Arabia

Epidemiology and diagnostic accuracy of Clostridium perfringens toxins in the intestinal contents of camels, sheep, and cattle: a cross-sectional study in Dakahlia governorate, Egypt

This study aimed to establish an accurate epidemiological surveillance tool for the detection of different C. perfringens types from 76 diseased and 34 healthy animals in Dakhalia Governorate, Egypt. A total of 110 intestinal content samples were randomly collected from camels, sheep, and cattle. C. perfringens was isolated and biochemically identified by the VITEK2 system. Toxinotyping and genotyping of C. perfringens isolates were specified by a multiscreen ELISA and real-time qPCR (rt-qPCR). The occurrence of C. perfringens was highest among camels (20% in healthy and 25% in diseased) and was lowest in cattle (23.1% and 14.7%). The cpa toxin was detected in all isolates by rt-qPCR and in 7 isolates by ELISA, ext toxin was detected in 7 isolates by rt-qPCR and in 6 isolates by ELISA, and cpb toxin was detected in 2 isolates by both rt-qPCR and ELISA. Four types of C. perfringens were identified by rt-qPCR, type A (65.2%), B (4.3%), C (4.3%), and D (26.1%), and three types by ELISA, type D (17.4%), A (8.7%) and C (4.3%). Our study indicated the prevalence of infection in Dakahlia by C. perfringens type A and D, particularly camels, and recommends adopting an appropriate vaccination strategy among the studied animals.

Moringa oleifera as a potential antimicrobial against pathogenic Clostridium perfringens isolates in farm animals

Background

Clostridium perfringens (CP) is an emerging anaerobic pathogen that can aggravate severe fatal infections in different hosts and livestock.

Aim

This paper was designed to monitor the antibacterial efficacy of Moringa oleifera (M. oleifera) plant against different CP isolates of variant toxin genotypes comparing that with commercial antibiotics in the veterinary field.

Methods

A total of 200 examined fecal, intestinal, and liver samples from cattle, sheep, and goats were investigated bacteriologically and biochemically for CP. Then, the isolates were examined by polymerase chain reaction (PCR) for toxin gene typing. Thereafter, the antimicrobial susceptibility testing as well as the antibacterial efficacy of M. oleifera were evaluated and statistically analyzed against recovered isolates.

Results

The prevalence rate of CP was 51% (102/200); of which 54.5% was from cattle, 50% from sheep, and 40% from goat. Moreover, all CP isolates were highly resistant to tetracycline and lincomycin drugs; meanwhile, they were of the least resistance against ciprofloxacin (8.3%-16.7%), cefotaxime (16.7%-25%), and gentamycin (26.7%-33.3%). For M. oleifera, high antibacterial efficacy with greater inhibition zones of the plant was recorded with its oil (20-24 mm) and ethanolic extracts (16-20 mm) against CP than the aqueous extract (≤ 10 mm). A good correlation was stated between M. oleifera oil and toxin type of CP isolates particularly type A followed by D and B types. Interestingly, the oil and ethanolic extracts of M. oleifera gave higher antibacterial efficacy than most commercial antibiotics against the recovered isolates.

Conclusion

This study highlighted the potent antibacterial properties of M. oleifera for suppressing CP isolated from farm animals; hence, more investigations on M. oleifera are suggested to support its use as a medical herbal plant substituting antibiotics hazards and resistance problems worldwide.

Epizootological monitoring of some bacterial infectious diseases of animals on the territory of the Republic of Kazakhstan

The presence of significant areas used for pastures in Kazakhstan makes it relevant to study the epizootic situation in terms of the incidence of animals during their grazing. The most frequent and dangerous diseases during this period are clostridiosis and listeriosis, which cause significant damage to livestock. Monitoring studies of the dynamics of morbidity among animals for infectious diseases during the grazing period were carried out on the basis of veterinary reporting. Bacteriological studies were carried out in a state laboratory using generally accepted microbiological methods. Analytical and statistical methods were used during the work. Monitoring studies indicate a significant spread of clostridiosis in the territory of Kazakhstan. The highest incidence rate was characterised by emphysematous carbuncle infection, which was recorded throughout the country, with an average frequency of about 40 cases per year. The incidence of braxy and anaerobic enterotoxemia occurred much less frequently and mainly in the southern regions of the country. Listeriosis was also observed only in some regions, but at the same time, a stationary focus of the disease was recorded in the Utylaut region, where cases of the disease are recorded annually. Conducted research made it possible to form the dynamics of the incidence of animals in the pasture period for these diseases, to determine the regions of the country with different intensity of the epizootic situation, as well as to carry out bacteriological isolation of a pure culture of the pathogen from samples taken in the foci of the disease. The studies made it possible to collect information on the features and mechanisms of the occurrence of diseases in the conditions of different regions of Kazakhstan and to develop a multi-vector strategy for preventive measures to eliminate animal diseases during the grazing period.

Seroprevalence, associated risk factors, and molecular detection of bovine brucellosis in rural areas of Egypt

The study was carried out on six villages in northern Egypt to evaluate the epidemiological situation of bovine brucellosis among 989 unvaccinated household cattle by Rose Bengal Plate Test (RBPT) and indirect ELISA (iELISA) and to investigate the existence of Brucella DNA using real-time PCR in 100 milk and 100 sera from seropositive cattle and 50 sera from seronegative cattle. The overall seroprevalence was 20.7% and 23.7% by RBPT and iELISA, respectively. Based on the iELISA results, the seroprevalence was significantly (P < 0.05) higher in the village II (34.7%) and cattle > 7 years (30.1%). More males than females were non-significant seropositive (P = 0.6). There was 95% agreement between RBPT and iELISA, although iELISA showed a higher positivity rate (23.7%, 95% CI: 0.21-0.26) than RBPT (20.7%, 95% CI: 0.18-0.24). DNA of Brucella was confirmed in 16 milk samples by IS711 qPCR from seropositive cattle, however, no Brucella DNA was detected in serum samples tested positive and negative. Brucella abortus was the only species detected based on the alkB gene. Prevalence is highly related to the sampling site and the age of the animals. In conclusion, although qPCR is more accurate and commonly used in the diagnosis of most infectious diseases but in this situation iELISA is preferred and recommended for continuous screening and animal movement restriction and vaccination protocols, especially in high-risk areas.

Immunogenicity of a newly developed vaccine against Clostridium perfringens alpha-toxin in rabbits and cattle

Background and Aim: Clostridium perfringens type A is an anaerobic bacterium that produces four major toxins (alpha, beta, epsilon, and iota) that cause various diseases. Most of the important C. perfringens-associated diseases of farm animals are caused by alpha-toxin. This study aimed to produce a vaccine against alpha-toxin using C. perfringens type A (ATCC 13124) and investigate its potency, stability, and safety. Materials and Methods: The vaccine was formulated of its constituents for 1 h. Each milliliter of the final vaccine product contained alpha toxoid 15 lecithovitellinase activity (Lv) by adding (0.375 mL containing 40 Lv) and approximately 0.2 mL from 3% concentrated aluminum hydroxide gel, <0.001% W/V thiomersal, <0.05% W/V formaldehyde, and nearly 0.425 mL phosphate-buffered saline (pH 7.2). The vaccine efficacy was evaluated in rabbits and cattle by performing potency, stability, and safety tests. Results: The vaccine produced approximately 8.8 and 4.9 IU/mL neutralizing antibodies in rabbits and cattle, respectively. These concentrations were higher than the lowest concentration recommended by various international protocols and the United States Department of Agriculture by 2.20-fold in rabbits and 1.23-fold in cattle. Interestingly, the formulated vaccine enhanced immune responses by 1.80-fold in rabbits compared with that in cattle; the difference was statistically significant (p < 0.0001). The vaccine was stable for 30 months. In vaccinated rabbits, the body temperature slightly increased temporarily during the first 10 h of vaccination; however, the temperature difference was not statistically significant (p > 0.05). Conclusion: This study describes a manufacturing process to obtain sufficient amounts of a vaccine against C. perfringens alpha-toxin. The formulated vaccine effectively elicited a higher level of neutralizing antibody response than the international standards. Furthermore, the vaccine was found to be stable, safe, and effective in preventing C. perfringens-related diseases in rabbits and cattle. Further studies are necessary to evaluate the efficacy of this vaccine in other farm animals.