BACKGROUND: Clostridium perfringens is an important animal pathogen that causes severe loses to the livestock and poultry industries. Therefore, bacterial detection is believed to be of particular importance. OBJECTIVES: The present study aimed to identify Iranian isolates using conventional and molecular methods and to evaluate their toxicity. METHODS: In this work, 23 Clostridium perfringens type B isolates were examined via microbiological and biochemical tests. Subsequently, they were subjected to PCR technique for the final confirmation. After culturing of the isolates in specific medium, the minimum lethal dose test was performed. The most toxigenic isolate and reference strain was prepared the enterotoxaemia anaculture vaccine. Serum neutralization test was performed on the experimental inactive vaccines. RESULTS: The results revealed that etx and cpb gene could be found in all of the isolates, yet cpb2 gene was found in 65.2 % of the isolates. The minimum lethal dose ranges for these bacteria was less than 1/10 to more than 1/900. The results of serum neutralization in Iranian isolate and reference strains were 5 and 10 IU / ml, respectively. CONCLUSIONS: The findings herein implied that strain 1795 with high toxicity could be used in vaccine production. Of course, for use in production, further research on target animals is needed.

BACKGROUND: Clostridium perfringens (C. perfringens) is an anaerobic Gram-positive bacillus with spores, whose biotype A is responsible for a variety of diseases, including intestinal inflammation, bloody diarrhea, and gas gangrene, and hemorrhagic bowel syndrome. Genetic variety can explain the bacteria’s phenotypic diversity, geographic distribution, host specificity, pathogenicity, antibiotic resistance, and virulence. A molecular method using the pattern of DNA bands classifies bacteria based on the size of fragments produced by enzymatic digestion of the genome.OBJECTIVES: This study aims to standardize the polymerase chain reaction (PCR)- restriction fragment length polymorphism (RFLP) method in identifying the genetic diversity of C. perfringens biotype A isolates.METHODS: The genomic DNA of the investigated strains was extracted, and the complete sequence of the alpha toxin gene locus was synthesized using specific primers designed by PCR technique. Enzymatic cleavage of the synthesized amplicons was performed with the Mse l restriction enzyme, and the resulting fragments were separated by electrophoresis and analyzed by ImageJ and NTSYSPC software.RESULTS: The findings showed that the alpha toxin gene locus sequence may change and is not conserved. In this research, 4 different patterns were identified based on enzymatic cleavage. Mutations in this locus can lead to diversity in C. perfringens biotype A and the creation of new strains.CONCLUSIONS: The results of this research showed that the alpha toxin gene locus could be considered a DNA molecular marker in C. perfringens, and the PCR-RFLP technique can be used as a tool for typing this bacterium and estimating the phylogenetic relationships through comparative studies of nucleotide sequences.

When Salmonella typhimurium and Clostridium perfringens were tested in conventional chickens, larger numbers of S typhimurium and C perfringens adhered to Eimeria tenella-infected ceca than to uninfected ceca. In germ-free chickens, S typhimurium and C perfringens adhered to the E tenella-infected cecal mucosa more than to the uninfected cecal mucosa, but fewer Bacteroides vulgatus and Bifidobacterium thermophilum adhered to the E tenella-infected ceca than to the uninfected ceca. Many bacteria adhered to the lesions caused by E tenella as observed by scanning electron microscopy. On the basis of our findings, we suggest that infection with E tenella upsets the balance of competitive adherence of bacteria, allowing more colonization of S typhimurium and C perfringens.

Spore-forming bacteria are a group of bacteria can form spore and they grow aerobically and anaerobically as Bacilli and Clostridia spp. This group of bacteria has public health hazards and economic loss significance. This study was designed to determine the prevalence of spore-forming bacteria isolated from marketable milk and some dairy products as pasteurized milk, UHT milk, milk powder, and baby food (30 samples of each). The samples were purchased randomly from different dairy shops, supermarkets, and pharmacies in Assiut Governorate, Egypt. Bacillus cereus was detected in 23.33, 13.33, 6.66, 13.33, and 10% from marketable milk, pasteurized milk, UHT milk, milk powder, and baby food, respectively. While, Clostridium perfringens was recovered in 20, 6.66, 0, 3.33 and 0%, respectively. This study concluded that there is a need for hygienic measures must be applied in the milk and dairy products production and manufacture to minimize the possibility of entering the spore-forming bacteria in these products.

In this study multiplex PCR was used for typing of Clostridium perfringens isolates from soil, clinically healthy and diseased sheep. Clostridium perfringens was isolated from 41 out of 100 soil samples, 12 out of 100 clinically healthy sheep and 118 out of 200 sheep with enterotoxaemia signs. Genotyping of 41 isolates from soil indicated that 29 (70.73%) were type A, 3 (7.31%) were type B and 9 (21.95%) were type D. Of 12 isolates from clinically healthy sheep 6 (50%) were type A and 6(50%) were type D. Of 118 isolates from diseased sheep 42 (35.59%) were type A, 22 (18.64%) were type B and 54 (45.76%) were type D. This result indicates that Clostridium perfringens type A, B and D are the main types causing enterotoxaemia in sheep in Egypt and Clostridium perfringens type A must be included in any vaccine programme to ensure optimum protection.

Silage quality deteriorates with Clostridium spp. contamination, and if consumed, such silage jeopardises herd health and productivity. Minimising its occurrence reduces economic and animal welfare risks. The study investigated the influence of environmental and technological determinants on the Clostridium genus’ occurrence in silage. Analyses were conducted on 305 silage samples directly collected from farms located in all Polish provinces. Cultures and isolates were evaluated phenotypically and examined for occurrence of Clostridium spp., particularly C. perfringens and C. botulinum using PCR techniques. The results were statistically analysed using the ᵡ² test for continuous and Student’s t-test for non-continuous values. The most influential effect on Clostridium spp. occurrence is exerted by factors potentially associated with primary production, like the type of fertilisation and the contamination level of the ensiled feed material. Clostridium spp. was detected in 232 (76%) samples, and C. perfringens strains, predominantly toxinotype A, in 79 (26%). C. botulinum occurrence was not detected. Deterioration of silage by clostridia could be prevented by a properly conducted ensiling process with the addition of starter cultures, but the presence of spores mainly depends on primary production and the extent of contamination of the feed material.

Introduction: Clostridium perfringens is commonly found in the gastrointestinal tract of animals and humans and continues to cause one of the most prevalent foodborne diseases in man. Material and Methods: A total of 355 samples were examined for the occurrence of C. perfringens: rectal swabs from cattle, sheep, and goats, fresh stool samples from diarrhoea sufferers having been in contact with these animals, irrigation water and soil samples from the husbandry sites, and preharvesting fresh produce from farms irrigated with the sampled water. All samples were collected from Cairo and Giza governorates, Egypt. PCR analysis was carried out with positive isolates using the α-toxin gene. Sequence analysis of the gene of C. perfringens isolates was performed using the neighbour-joining approach. Bootstrap analysis was executed with 1,000 resamplings. Results: 174 C. perfringens strains were isolated with a 49.01% prevalence. The highest prevalence of C. perfringens in apparently healthy animals was found in sheep (65.45%) followed by goats (58%), buffaloes (55%), and cattle (47.1%). Its prevalence in humans being in contact with these animals was 47.5%. The bacterium’s isolation from the soil and irrigation water was achieved in 40% and 31.7% of samples, respectively, posing a risk, particularly when the water and soil contact food in the field, shown by the fresh produce isolation of 40%. A significant relationship between the prevalence of C. perfringens in animal and environmental samples was identified (P < 0.05). A significant relationship was identified neither between animal species and C. perfringens prevalence, nor between the environmental source and C. perfringens prevalence (P > 0.05). All isolates were positive for the α-toxin gene by PCR. The sequence analysis and the phylogenetic relationship of the α-toxin genes from different samples revealed that C. perfringens from faeces of apparently healthy cattle, buffaloes, sheep, and goats is a significant threat in places where it can contaminate the soil and water. In addition, the sequence of C. perfringens from humans suffering from diarrhoea was found in the same cluster with the sequence from cows, goats, and sheep. Conclusion: The role of apparently healthy animals in transmitting C. perfringens to humans, either through being in direct or indirect contact via water or soil in the cultivation of vegetables and fruits, was demonstrated.

The aim of this study was examination of honey samples collected from apiaries situated in all Polish provinces for occurrence of Clostridium spp., especially C. perfringens. The study was carried out on 240 honey samples (15 samples/province). Estimation of Clostridium titre, its cultures and C. perfringens isolate characterisation were performed according to the standard PN-R-64791:1994. A multiplex PCR method for detection of genes coding cpa (α toxin), cpb (β), cpb2 (β2), etx (ε), iap (ι), and cpe (enterotoxin) toxins was used. Clostridium spp. was noticed in 56% (136/240) of samples, and its titres ranged between 0.1 g and 0.001 g. Clostridium perfringens occurrence was evidenced in 27.5% (66/240) of samples. All isolates were classified to toxinotype A. Evidence of a high number of positive samples with occurrence of Clostridium spp. indicates a potential risk to consumers’ health. The infective number of Clostridium spp. is unknown; however, the obtained results have shown that a risk assessment on the entire honey harvesting process should be made in order to ensure microbiological safety. Moreover, a detailed study should be undertaken on the antibiotic resistance of C. perfringens isolates from honey samples.