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The occurrcnce of Clostridium perfringens in particular links of food chain and their toxic potential was studied. Compound feeding stuffs, poultry, swine, and bovine faeces, food of animal origin, and human faeces were examined microbiologically. The isolated anaerobes were analysed for presence of toxin genes (cpa, cpb, cpb2, etx, iap, and cpe). The presence of C. perfringens on level higher than 1.0 x 10¹ cfu/g were detected in 68% of feed samples, 36% of poultry faeces, 92% of swine faeces, 67% of bovine faeces, 4% of food samples, and in 67% of human faeces. The detected levels of type A C. perfringens strains did not exceed the number of these strains physiologically present in the intestines of birds and mammals. Food and feed samples also revealed good microbiological quality. The identification of toxin type and subtype revealed domination of type A strains and among them the percentage of subtype ß2 strains varied considerably. The second toxotype detected was toxotype E. There were no cpe-positive strains in the analysed food of animal origin.
In this study, Clostridium perfringens strains isolated from feedingstuffs were characterised phenotypically (width of lecithinolysis and partial haemolysis zones, biochemical reactions and resistance to antibacterial substances) and genotypically (presence of toxin genes and genomic polymorphism analysis). C. perfringens toxin genes were detected by multiplex PCR and genomic polymorphism was analysed by pulsed field gel electrophoresis. It was demonstrated that C. perfringens strains type A, among which more than half belonged to subtype ß2, were the most commonly isolated strains. Strains containing cpb2 gene revealed higher diversity of their biochemical reactions, more often occurring antibiotic resistance, and lower genomic DNA profile similarity. Feedingstuffs may serve as a source of C. perfringens, the most important animal pathogen among anaerobic sporulating bacteria. Widely occurrence of cpb2 gene among C. perfringens isolates from feedingstuffs may suggest taking into account ß2 toxin in animal immunoprophylaxis. The knowledge gained in this study shows feedingstuffs as a source of C. perfringens ß2 toxin in food chain and sheds light on the animal immunoprophylaxis regarding diseases caused by this microorganism.
Microbiological quality of feed materials used in Poland in 2007-2010 was assessed. The examinations were conducted at all veterinary diagnostic laboratories. Feed samples were examined on Salmonella prevalence and level of contamination by aerobic mesophilic bacteria, microorganisms, Enterobacteriaceae and fungi. Salmonella sp. was the most often detected in feed materials of animal origin. The number of Enterobacteriaceae in most of the examined feed samples did not exceed 10 cfu/g. The demonstrated contamination by aerobic bacteria ranged most often from 10 to 10⁷ cfu/g. Analysis of mycological status of feed materials indicated that the highest contamination by fungi was 10⁸ cfu/g in cereal grains.
The occurrence of pathogenic microorganisms in animal feed is risky for animals and, if transported by food of animal origin, may also pose a risk for humans. Moreover, permanent animal exposure to excessive saprophytic microorganisms in an unhygienic environment and feedingstuffs provokes pro-inflammatory cytokine production and an increase in metabolism activity, which, in turn, causes a decrease in productivity. Mycological contamination of animal feed may additionally cause mycosis, allergies and, above all, micotoxicoses. The most often detected microorganisms in animal feedingstuffs are Salmonella spp. and Clostridium spp. and factors of feed hygiene are aerobic bacteria count, fungi count, Enterobacteriaceae count and Clostridium perfringens count.
The aim of this work was to present selected data regarding traditional and modern methods for C. botulinum and its toxins detection. In this article, methods based on culturing techniques, mouse bioassay, immunological techniques, chromatography and PCR, PFGE, RFLP, AFLP are described. The mentioned techniques were evaluated considering their usefulness in the samples examination, genotyping of strains and the diagnostics of botulism.
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The aim of the study was the microbiological quality assessment of feed materials produced and used in animal feeding in Poland. Examinations were conducted in all regional laboratories dealing with animal feedstuff testing. Prevalence of Salmonella sp. and Clostridium sp. were assessed, as well as mesophilic aerobic bacteria, Enterobacteriaceae and fungi counts. The following materials were examined: 9 389 samples in the year 2003, 5 716 samples in 2004, 4 490 samples in 2005 and 6 905 samples feed materials in 2006. Assays were done following Polish standards harmonized with European standards and/or international (ISO) standards. Most often Salmonella sp. were detected in extracted oil seed meal samples, and the percentage of positive samples, depending on the examined materials, ranged from 1.5 to 7.7. The number of Enterobacteriaceae in most of the examined meat and bone meal samples did not exceed 10 cfu/g, and in oil seed meals 100 cfu/g. The highest level of contamination by Enterobacteriaceae confirmed in plant feed materials reached the level 10⁴ cfu/g. The most often confirmed level of contamination by aerobic bacteria ranged from 10² to 10⁶ cfu/g. In the mycological studies performed more than 10⁵ fungi per gram were detected in 0.8% of oil seed meal samples and more than 2% of cereal samples. The highest level of contamination by aerobic bacteria and fungi were detected in the cereal samples examined. Most examined feed material samples showed Clostridium sp. presence in titre from 0.01 to less than 0.1. Clostridium species occurred in meat and bone meal samples more often than in oil seed meal and cereal samples. The results obtained indicate an urgent need for the verification of previous microbiological criteria established for feed materials.
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