Polymerase chain reaction test for differentiation of five toxin types of Clostridium perfringens

Bacteriological and serological investigation of Clostridium perfringens in lambs

Clostridium perfringens is one of the most common and important pathogens in livestock due to its ability to produce a diverse arsenal of toxins. Owing to C. perfringens economic importance, this study aimed to determine the types and toxins of C. perfringens in newly born lambs. A total of 200 lambs of less than one-month old were examined, including 100 lambs suffered from diarrhea, 60 freshly dead and 40 apparent healthy. C. perfringens was identified morphologically and biochemically using bacteriological culture in 103 of 200 samples (51.5%). Moreover, serological typing of C. perfringens isolates revealed three serotypes, C. perfringens type A (54.2%), C. perfringens type B (28.8%) and C. perfringens type D (16.9%). The highest prevalence rate for C. perfringens infection was observed in winter (58.25%) in comparison with other seasons. The findings of the present study confirm the presence of enterotoxmia among lambs in localities under study, causing economic losses. The proper vaccination schedule particularly against C. perfringens type A and B is highly recommended.

Infection Dynamics of Clostridium perfringens Fingerprinting in Buffalo and Cattle of Punjab Province, Pakistan

Clostridium perfringens produces core virulence factors that are responsible for causing hemorrhagic abomasitis and enterotoxemia making food, animals, and humans susceptible to its infection. In this study, C. perfringens was isolated from necropsied intestinal content of buffalo and cattle belonging to four major bovine-producing regions in the Punjab Province of Pakistan for the purpose offind out the genetic variation. Out of total 160 bovine samples (n: 160), thirty-three (n: 33) isolates of C. perfringens were obtained from buffalo (Bubales bubalis) and cattle (Bos indicus) that were further subjected to biochemical tests; 16S rRNA based identification and toxinotyping was done using PCR (Polymerase Chain Reaction) and PFGE (Pulse Field Gel Electrophoresis) pulsotypesfor genetic diversity. Occurrence of C. perfringens was found to be maximum in zone-IV (Bhakkar and Dera Ghazi Khan) according to the heatmap. Correlation was found to be significant and positive among the toxinotypes (α-toxin, and ε-toxin). Response surface methodology (RSM) via central composite design (CCD) and Box-Behnken design (BBD) demonstrated substantial frequency of C. perfringens based toxinotypes in all sampling zones. PFGE distinguished all isolates into 26 different pulsotypes using SmaI subtyping. Co-clustering analysis based on PFGE further decoded a diversegenetic relationship among the collected isolates. This study could help us to advance toward disease array of C. perfringens and its probable transmission and control. This study demonstrates PFGE patterns from Pakistan, and typing of C. perfringens by PFGE helps illustrate and mitigate the incidence of running pulsotypes.

Occurrence and Toxicogenetic Profiling of Clostridium perfringens in Buffalo and Cattle: An Update from Pakistan

Clostridium perfringens is a Gram-positive bacterium that possess seven toxinotypes (A, B, C, D, E, F, and G) that are responsible for the production of six major toxins, i.e., α, β, ε, ι, CPE, and NetB. The aim of this study is to find out the occurrence of toxinotypes in buffalo and cattle of Punjab province in Pakistan and their corresponding toxin-encoding genes from the isolated toxinotypes. To accomplish this aim, six districts in Punjab province were selected (i.e., Lahore, Sahiwal, Cheecha Watni, Bhakkar, Dera Ghazi Khan, and Bahawalpur) and a total of 240 buffalo and 240 cattle were selected for the collection of samples. From isolation and molecular analysis (16S rRNA), it was observed that out of seven toxinotypes (A–G), two toxinotypes (A and D) were found at most, whereas other toxinotypes, i.e., B, C, E, F, and G, were not found. The most frequently occurring toxinotype was type A (buffalo: 149/240; cattle: 157/240) whereas type D (buffalo: 8/240 cattle: 7/240) was found to occur the least. Genes encoding toxinotypes A and D were cpa and etx, respectively, whereas genes encoding other toxinotypes were not observed. The occurrence of isolated toxinotypes was studied using response surface methodology, which suggested a considerable occurrence of the isolated toxinotypes (A and D) in both buffalo and cattle. Association between type A and type D was found to be significant among the isolated toxinotypes in both buffalo and cattle (p ≤ 0.05). Correlation was also found to be positive and significant between type A and type D. C. perfringens exhibits a range of toxinotypes that can be diagnosed via genotyping, which is more reliable than classical toxinotyping.

Visual Detection of Clostridium perfringens Alpha Toxin by Combining Nanometer Microspheres with Smart Phones

Clostridium perfringens α toxin (CPA) is an important virulence factor that causes livestock hemorrhagic enteritis and food poisoning by contaminated meat products. In this study, the nano-silica microspheres combined with smartphone image processing technology was developed to realize real-time CPA detection. First, the N-terminal and C-terminal domain of the CPA toxin (CPA_C3 and CPA_N) and their anti-sera were prepared. The silica microspheres coupled with the antibody of CPA_C3 was prepared to capture the toxin that existed in the detection sample and the fluorescent-labeled antibody of CPA_N was incubated. Moreover, the fluorescent pictures of gray value were performed in a cell phone app, corresponding to toxin concentration. The new assay takes 90 min to perform and can detect CPA as little as 32.8 ng/mL. Our results showed a sensitive, stable, and convenient CPA detection system, which provides a novel detection method of native CPA in foods.

Four foodborne disease outbreaks caused by a new type of enterotoxin-producing Clostridium perfringens

The epidemiological and bacteriological investigations on four foodborne outbreaks caused by a new type of enterotoxin-producing Clostridium perfringens are described. C. perfringens isolated from patients of these outbreaks did not produce any known enterotoxin and did not carry the C. perfringens enterotoxin gene. However, the culture filtrates of these isolates induced the accumulation of fluid in rabbit ileal loop tests. The molecular weight of the new enterotoxin may be between 50,000 and 100,000, although the known C. perfringens enterotoxin is ca. 35,000. This new enterotoxin was heat labile, and its biological activities were inactivated by heating for 5 min at 60°C. The new enterotoxin was sensitive to pH values higher than 11.0 and protease treatment but was resistant to trypsin treatment. These results suggest that the new enterotoxin may be a protein. Although C. perfringens enterotoxin induced morphological changes in Vero cells, the changes induced by the new enterotoxin differed from those by the known C. perfringens enterotoxin. The new enterotoxin also induced morphological changes in L929 cells, whereas the known C. perfringens enterotoxin did not, because L929 cells lacked an appropriate enterotoxin receptor. Although C. perfringens enterotoxin is recognized as the only diarrheagenic toxin responsible for C. perfringens foodborne outbreaks, the results of the present study indicate that C. perfringens isolated from these four outbreaks produced a new type of enterotoxin.

Detection and toxin typing of Clostridium perfringens in formalin-fixed, paraffin-embedded tissue samples by PCR

Since current microbiology methods are not suitable to detect Clostridium perfringens in formalin-fixed, paraffin-embedded tissue samples, we developed a PCR assay to detect toxin-encoding genes and the 16S rRNA gene of C. perfringens. We successfully detected and genotyped C. perfringens in tissue sections from two autopsy cases.

Survival of clostridium perfringens during simulated transport and stability of some plasmid-borne toxin genes under aerobic conditions

Clostridium perfringens is a pathogen of great concern in veterinary medicine, because it causes enteric diseases and different types of toxaemias in domesticated animals. It is important that bacteria in tissue samples, which have been collected in the field, survive and for the classification of C. perfringens into the correct toxin group, it is crucial that plasmid-borne genes are not lost during transportation or in the diagnostic laboratory. The objectives of this study were to investigate the survival of C. perfringens in a simulated transport of field samples and to determine the stability of the plasmid-borne toxin genes cpb1 and etx after storage at room temperature and at 4 degrees C. Stability of the plasmid-borne genes cpb1 and etx of C. perfringens CCUG 2035, and cpb2 from C. perfringens CIP 106526, JF 2255 and 6 field isolates in aerobic atmosphere was also studied. Survival of C. perfringens was similar in all experiments. The cpbl and etx genes were detected in all isolates from samples stored either at room temperature or at 4 degrees C for 24-44 h. Repeated aerobic treatment of C. perfringens CCUG 2035 and CIP 106526 did not result in the loss of the plasmid-borne genes cpb1, cpb2 or etx. Plasmid-borne genes in C. perfringens were found to be more stable than generally reported. Therefore, C. perfringens toxinotyping by PCR can be performed reliably, as the risk of plasmid loss seems to be a minor problem.

Clostridium perfringens: insight into virulence evolution and population structure

Clostridium perfringens is an important pathogen in veterinary and medical fields. Diseases caused by this organism are in many cases life threatening or fatal. At the same time, it is part of the ecological community of the intestinal tract of man and animals. Virulence in this species is not fully understood and it does seem that there is erratic distribution of the toxin/enzyme genes within C. perfringens population. We used the recently developed multiple-locus variable-number tandem repeat analysis (MLVA) scheme to investigate the evolution of virulence and population structure of this species. Analysis of the phylogenetic signal indicates that acquisition of the major toxin genes as well as other plasmid-borne toxin genes is a recent evolutionary event and their maintenance is essentially a function of the selective advantage they confer in certain niches under different conditions. In addition, it indicates the ability of virulent strains to cause disease in different host species. More interestingly, there is evidence that certain normal flora strains are virulent when they gain access to a different host species. Analysis of the population structure indicates that recombination events are the major tool that shapes the population and this panmixia is interrupted by frequent clonal expansion that mostly corresponds to disease processes. The signature of positive selection was detected in alpha toxin gene, suggesting the possibility of adaptive alleles on the other chromosomally encoded determinants. Finally, C. perfringens proved to have a dynamic population and availability of more genome sequences and use of comparative proteomics and animal modeling would provide more insight into the virulence of this organism.

Binary bacterial toxins: biochemistry, biology, and applications of common Clostridium and Bacillus proteins

Certain pathogenic species of Bacillus and Clostridium have developed unique methods for intoxicating cells that employ the classic enzymatic "A-B" paradigm for protein toxins. The binary toxins produced by B. anthracis, B. cereus, C. botulinum, C. difficile, C. perfringens, and C. spiroforme consist of components not physically associated in solution that are linked to various diseases in humans, animals, or insects. The "B" components are synthesized as precursors that are subsequently activated by serine-type proteases on the targeted cell surface and/or in solution. Following release of a 20-kDa N-terminal peptide, the activated "B" components form homoheptameric rings that subsequently dock with an "A" component(s) on the cell surface. By following an acidified endosomal route and translocation into the cytosol, "A" molecules disable a cell (and host organism) via disruption of the actin cytoskeleton, increasing intracellular levels of cyclic AMP, or inactivation of signaling pathways linked to mitogen-activated protein kinase kinases. Recently, B. anthracis has gleaned much notoriety as a biowarfare/bioterrorism agent, and of primary interest has been the edema and lethal toxins, their role in anthrax, as well as the development of efficacious vaccines and therapeutics targeting these virulence factors and ultimately B. anthracis. This review comprehensively surveys the literature and discusses the similarities, as well as distinct differences, between each Clostridium and Bacillus binary toxin in terms of their biochemistry, biology, genetics, structure, and applications in science and medicine. The information may foster future studies that aid novel vaccine and drug development, as well as a better understanding of a conserved intoxication process utilized by various gram-positive, spore-forming bacteria.

Propionibacterium acnesbiotypes and susceptibility to minocycline andKeigai-rengyo-to

BACKGROUND

Propionibacterium acnes is the predominant organism in acne lesions, but the sensitivity of different biotypes of P. acnes to therapeutic agents has seldom been reported.

METHODS

To characterize biotypes of P. acnes and to measure the effects of Keigai-rengyo-to (KRT) and minocycline (MINO) on clinical P. acnes isolates.

RESULTS

Propionibacterium acnes biotype III (BIII) is the most common form of identified acne lesion, followed by P. acnes biotype I. BIII was isolated from mild, moderate and severe severity and the average lipase activity of BIII was higher than that of Biotypes I, II, IV and V. No significant differences in the decrease of free fatty acid production elicited by KRT or by MINO were found between BIII and the other biotypes. The degree of decreased butyric acid production was greater than that of propionic acid production in the medium supplemented with MINO. The percent decrease of butyric acid production elicited by 1 mg/mL of KRT was the same as that elicited by 0.1 microg/mL of MINO. Among biotypes of P. acnes, the minimal inhibitory concentrations of agents tested were generally higher in erythritol-positive biotypes than in erythritol-negative biotypes.

CONCLUSION

The high frequency of BIII might be responsible for the severity of acne in patients. It seems that if the same concentrations of MINO and KRT are used, the antilipase activity of MINO is stronger than that of KRT. Minocycline also has a direct anti-lipase activity against P. acnes. The mechanism underlying the influence of erythritol on the susceptibility of P. acnes to these agents remains unknown.

Clostridium perfringens and foodborne infections

Clostridium perfringens type A food poisoning is one of the more common in the industrialised world. This bacterium is also responsible for the rare but severe food borne necrotic enteritis. C. perfringens enterotoxin (CPE) has been shown to be the virulence factor responsible for causing the symptoms of C. perfringens type A food poisoning. CPE is a single polypeptide chain with a molecular weight of 3.5 kDa that binds to receptors on the target epithelial cells. Through a unique four-step membrane action it finally causes a breakdown in normal plasma membrane permeability properties. Genetic studies of cpe have shown that cpe can be either chromosomal or plasmid-borne and that only a small minority of the global C. perfringens population is cpe positive. CPE expression appears to be transcriptionally regulated during sporulation, at least in part, by regulatory factors that are common to all C. perfringens isolates.

Clostridium perfringens beta2-toxin in an African elephant (Loxodonta africana) with ulcerative enteritis

A 22-year-old female African elephant (Loxodonta africana) developed diarrhoea of unknown cause which lasted for two days. The animal was euthanased after it remained recumbent and refused to get up. Gross pathological changes were present mainly in the gastrointestinal tract. The intestinal contents were watery and dark brown. Several areas of the mucosa of the small intestine were covered minimally to moderately with fibrin and had a few 0.1 x 10 to 15 cm linear ulcerations. Microscopical lesions consisted of discrete areas of necrosis of the surface and crypt epithelium without overt inflammatory infiltrates. Culture of the small intestinal contents resulted in a moderate growth of Clostridium perfringens. No salmonella were found in the small or large intestine. PCR of the isolate of C. perfringens revealed the presence of the beta2-toxin gene cpb2 and the alpha-toxin gene cpa but no other known toxin genes. The expression of the beta2-toxin gene in vivo was demonstrated by the immunohistochemical localisation of the beta2-toxin to the microscopical lesions in the small intestine.

Rapid and direct detection of clostridium chauvoei by PCR of the 16S-23S rDNA spacer region and partial 23S rDNA sequences

Clostridium chauvoei causes blackleg, which is difficult to distinguish from the causative clostridia of malignant edema. Therefore, a single-step PCR system was developed for specific detection of C. chauvoei DNA using primers derived from the 16S-23S rDNA spacer region and partial 23S rDNA sequences. The specificity of the single-step PCR system was demonstrated by testing 37 strains of clostridia and 3 strains of other genera. A 509 bp PCR product, which is a C. choauvoei-specific PCR product, could be amplified from all of the C. chauvoei strains tested, but not from the other strains. Moreover, this single-step PCR system specifically detected C. chauvoei DNA in samples of muscle from mice 24 hr after inoculation with 100 spores of C. chauvoei, and in clinical materials from a cow affected with blackleg. These results suggest that our single-step PCR system may be useful for direct detection of C. chauvoei in culture and in clinical materials from animals affected with blackleg.

PCR detection of Clostridium perfringens type D in formalin-fixed, paraffin-embedded tissues of goats and sheep

A polymerase chain reaction (PCR) was used to identify the genes encoding the alpha, epsilon and beta toxins of Clostridium perfringens in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep. When pure cultures of Cl. perfringens types B and D were used as control templates in the PCR, products of the following sizes were observed on the agarose gel: 247 bp (alpha primers), 1025 bp (beta primers) and 403 bp (epsilon primers). When used to identify Cl. perfringens type D in formalin-fixed, paraffin-embedded intestinal tissues of goats and sheep, the PCR technique resulted in the detection of this micro-organism in 11 out of 13 samples known to be infected with Cl. perfringens. No false positive results were obtained when 13 culturally negative samples were analysed by the PCR technique.

Clostridium perfringens: toxinotype and genotype

Clostridium perfringens is a ubiquitous pathogen that produces many toxins and hydrolytic enzymes. Because the toxin-encoding genes can be located on extrachromosomal elements or in variable regions of the chromosome, several pathovars have arisen, each of which is involved in a specific disease. Pathovar identification is required for a precise diagnosis of associated pathologies and to define vaccine requirements. For these purposes, toxin genotyping is more reliable than the classical toxinotyping.