scholarly journals Characterization of Toxin Plasmids in Clostridium perfringens Type C Isolates

2010 ◽  
Vol 78 (11) ◽  
pp. 4860-4869 ◽  
Author(s):  
Abhijit Gurjar ◽  
Jihong Li ◽  
Bruce A. McClane

ABSTRACT Clostridium perfringens type C isolates cause enteritis necroticans in humans or necrotizing enteritis and enterotoxemia in domestic animals. Type C isolates always produce alpha toxin and beta toxin but often produce additional toxins, e.g., beta2 toxin or enterotoxin. Since plasmid carriage of toxin-encoding genes has not been systematically investigated for type C isolates, the current study used Southern blot hybridization of pulsed-field gels to test whether several toxin genes are plasmid borne among a collection of type C isolates. Those analyses revealed that the surveyed type C isolates carry their beta toxin-encoding gene (cpb) on plasmids ranging in size from ∼65 to ∼110 kb. When present in these type C isolates, the beta2 toxin gene localized to plasmids distinct from the cpb plasmid. However, some enterotoxin-positive type C isolates appeared to carry their enterotoxin-encoding cpe gene on a cpb plasmid. The tpeL gene encoding the large clostridial cytotoxin was localized to the cpb plasmids of some cpe-negative type C isolates. The cpb plasmids in most surveyed isolates were found to carry both IS1151 sequences and the tcp genes, which can mediate conjugative C. perfringens plasmid transfer. A dcm gene, which is often present near C. perfringens plasmid-borne toxin genes, was identified upstream of the cpb gene in many type C isolates. Overlapping PCR analyses suggested that the toxin-encoding plasmids of the surveyed type C isolates differ from the cpe plasmids of type A isolates. These findings provide new insight into plasmids of proven or potential importance for type C virulence.

2020 ◽  
pp. 030098582097178
Author(s):  
Llorenç Grau-Roma ◽  
Mauricio Navarro ◽  
Sohvi Blatter ◽  
Christian Wenker ◽  
Sonja Kittl ◽  
...  

Several outbreaks of necrotic enteritis-like disease in lorikeets, from which Clostridium perfringens was consistently isolated, are described. All lorikeets had acute, segmental, or multifocal fibrinonecrotizing inflammatory lesions in the small and/or the large intestine, with intralesional gram-positive rods. The gene encoding C. perfringens alpha toxin was detected by PCR (polymerase chain reaction) on formalin-fixed, paraffin-embedded (FFPE) tissues in 20 out of 24 affected lorikeets (83%), but it was not amplified from samples of any of 10 control lorikeets ( P < .0001). The second most prevalent C. perfringens toxin gene detected was the beta toxin gene, which was found in FFPE from 7 out of 24 affected lorikeets (29%). The other toxin genes were detected inconsistently and in a relatively low number of samples. These cases seem to be associated with C. perfringens, although the specific type involved could not be determined.


2008 ◽  
Vol 190 (21) ◽  
pp. 7178-7188 ◽  
Author(s):  
Kazuaki Miyamoto ◽  
Jihong Li ◽  
Sameera Sayeed ◽  
Shigeru Akimoto ◽  
Bruce A. McClane

ABSTRACT Clostridium perfringens type B and D isolates produce epsilon-toxin, the third most potent clostridial toxin. The epsilon-toxin gene (etx) is plasmid borne in type D isolates, but etx genetics have been poorly studied in type B isolates. This study reports the first sequencing of any etx plasmid, i.e., pCP8533etx, from type B strain NCTC8533. This etx plasmid is 64.7 kb, carries tcp conjugative transfer genes, and encodes additional potential virulence factors including beta2-toxin, sortase, and collagen adhesin but not beta-toxin. Interestingly, nearly 80% of pCP8533etx open reading frames (ORFs) are also present on pCPF5603, an enterotoxin-encoding plasmid from type A isolate F5603. Pulsed-field gel electrophoresis and overlapping PCR indicated that a pCP8533etx-like etx plasmid is also present in most, if not all, other type B isolates and some beta2-toxin-positive, cpe-negative type D isolates, while other type D isolates carry different etx plasmids. Sequences upstream of the etx gene vary between type B isolates and some type D isolates that do not carry a pCP8533etx-like etx plasmid. However, nearly all type B and D isolates have an etx locus with an upstream IS1151, and those etx loci typically reside near a dcm ORF. These results suggest that pCPF5603 and pCP8533etx evolved from insertion of mobile genetic elements carrying enterotoxin or etx genes, respectively, onto a common progenitor plasmid.


2015 ◽  
Vol 83 (6) ◽  
pp. 2369-2381 ◽  
Author(s):  
Jianming Chen ◽  
Bruce A. McClane

Large clostridial toxins (LCTs) are produced by at least four pathogenic clostridial species, and several LCTs are proven pivotal virulence factors for both human and veterinary diseases. TpeL is a recently identified LCT produced byClostridium perfringensthat has received relatively limited study. In response, the current study surveyed carriage of thetpeLgene among differentC. perfringensstrains, detecting this toxin gene in some type A, B, and C strains but not in any type D or E strains. This study also determined that all tested strains maximally produce, and extracellularly release, TpeL at the late-log or early-stationary growth stage duringin vitroculture, which is different from the maximal late-stationary-phase production reported previously for other LCTs and for TpeL production byC. perfringensstrain JIR12688. In addition, the present study found that TpeL levels in culture supernatants can be repressed by either glucose or sucrose. It was also shown that, at natural production levels, TpeL is a significant contributor to the cytotoxic activity of supernatants from cultures oftpeL-positive strain CN3685. Lastly, this study identified TpeL, which presumably is produced in the intestines during diseases caused by TpeL-positive type B and C strains, as a toxin whose cytotoxicity decreases after treatment with trypsin; this finding may have pathophysiologic relevance by suggesting that, like beta toxin, TpeL contributes to type B and C infections in hosts with decreased trypsin levels due to disease, diet, or age.


2014 ◽  
Vol 82 (7) ◽  
pp. 2958-2970 ◽  
Author(s):  
Menglin Ma ◽  
Abhijit Gurjar ◽  
James R. Theoret ◽  
Jorge P. Garcia ◽  
Juliann Beingesser ◽  
...  

ABSTRACTThe ability ofClostridium perfringenstype C to cause human enteritis necroticans (EN) is attributed to beta toxin (CPB). However, many EN strains also expressC. perfringensenterotoxin (CPE), suggesting that CPE could be another contributor to EN. Supporting this possibility, lysate supernatants from modified Duncan-Strong sporulation (MDS) medium cultures of three CPE-positive type C EN strains caused enteropathogenic effects in rabbit small intestinal loops, which is significant since CPE is produced only during sporulation and sinceC. perfringenscan sporulate in the intestines. Consequently, CPE and CPB contributions to the enteropathogenic effects of MDS lysate supernatants of CPE-positive type C EN strain CN3758 were evaluated using isogeniccpbandcpenull mutants. While supernatants of wild-type CN3758 MDS lysates induced significant hemorrhagic lesions and luminal fluid accumulation, MDS lysate supernatants of thecpbandcpemutants caused neither significant damage nor fluid accumulation. This attenuation was attributable to inactivating these toxin genes since complementing thecpemutant or reversing thecpbmutation restored the enteropathogenic effects of MDS lysate supernatants. Confirming that both CPB and CPE are needed for the enteropathogenic effects of CN3758 MDS lysate supernatants, purified CPB and CPE at the same concentrations found in CN3758 MDS lysates also acted together synergistically in rabbit small intestinal loops; however, only higher doses of either purified toxin independently caused enteropathogenic effects. These findings provide the first evidence for potential synergistic toxin interactions duringC. perfringensintestinal infections and support a possible role for CPE, as well as CPB, in some EN cases.


2006 ◽  
Vol 74 (9) ◽  
pp. 5200-5210 ◽  
Author(s):  
Derek J. Fisher ◽  
Mariano E. Fernandez-Miyakawa ◽  
Sameera Sayeed ◽  
Rachael Poon ◽  
Victoria Adams ◽  
...  

ABSTRACT The gram-positive anaerobe Clostridium perfringens produces a large arsenal of toxins that are responsible for histotoxic and enteric infections, including enterotoxemias, in humans and domestic animals. C. perfringens type C isolates, which cause rapidly fatal diseases in domestic animals and enteritis necroticans in humans, contain the genes for alpha toxin (plc), perfringolysin O (pfoA), beta toxin (cpb), and sometimes beta2 toxin (cpb2) and/or enterotoxin (cpe). Due to the economic impact of type C-induced diseases, domestic animals are commonly vaccinated with crude type C toxoid (prepared from inactivated culture supernatants) or bacterin/toxoid vaccines, and it is not clear which toxin(s) present in these vaccines actually elicits the protective immune response. To improve type C vaccines, it would be helpful to assess the contribution of each toxin present in type C supernatants to lethality. To address this issue, we surveyed a large collection of type C isolates to determine their toxin-producing abilities. When late-log-phase vegetative culture supernatants were analyzed by quantitative Western blotting or activity assays, most type C isolates produced at least three lethal toxins, alpha toxin, beta toxin, and perfringolysin O, and several isolates also produced beta2 toxin. In the mouse intravenous injection model, beta toxin was identified as the main lethal factor present in type C late-log-phase culture supernatants. This conclusion was based on monoclonal antibody neutralization studies and regression analyses in which the levels of alpha toxin, beta toxin, perfringolysin O, and beta2 toxin production were compared with lethality. Collectively, our results highlight the importance of beta toxin for type C-induced toxemia.


2000 ◽  
Vol 134 (1) ◽  
pp. 77-87 ◽  
Author(s):  
WILFRIED VAHJEN ◽  
K. GOLLNISCH ◽  
O. SIMON ◽  
E. SCHULZ

Total DNA was extracted and purified from luminal digesta samples (1 g) of 14-week-old (c. 43 kg bodyweight) pigs. Digoxigenin (DIG) labelled PCR products of the beta toxin gene of Clostridium perfringens type C were generated with DIG-11-UTP and chemoluminescent signals of DIG-labelled PCR products were detected on slot blots and recorded with a sensitive charge coupled densitometric camera. Detection limit and correlation of chemoluminescent signals to initial target DNA concentration were evaluated. Detection of the beta toxin gene could be achieved with 100 ag C. perfringens DNA in the presence of 1 μg unspecific DNA. The semiquantitative DIG-PCR assay was used to evaluate the relative abundance of the beta toxin gene of C. perfringens type C in purified DNA extracts from intestinal samples of pigs, which were fed a wheat/barley diet (controls), supplemented with the antibiotic avilamycin (40 mg/kg feed), a xylanase (4000 U/kg feed) or a combination of both feed additives. The antibiotic treatment significantly reduced the amount of PCR product in ileal and colon DNA extracts. Xylanase supplementation significantly reduced the amount of PCR product in colon samples, but led to an increase in jejunal samples. From the results it is concluded, that the antibiotic inhibited growth of C. perfringens type C in the ileum and colon of pigs. The semiquantitative DIG-PCR assay can be used to sensitively monitor the relative abundance of specific pathogens in the intestinal tract.


2008 ◽  
Vol 76 (10) ◽  
pp. 4396-4404 ◽  
Author(s):  
Jorge E. Vidal ◽  
Bruce A. McClane ◽  
Juliann Saputo ◽  
Jaquelyn Parker ◽  
Francisco A. Uzal

ABSTRACT Clostridium perfringens type B and type C isolates, which produce beta-toxin (CPB), cause fatal diseases originating in the intestines of humans or livestock. Our previous studies demonstrated that CPB is necessary for type C isolate CN3685 to cause bloody necrotic enteritis in a rabbit ileal loop model and also showed that purified CPB, in the presence of trypsin inhibitor (TI), can reproduce type C pathology in rabbit ileal loops. We report here a more complete characterization of the effects of purified CPB in the rabbit small and large intestines. One microgram of purified CPB, in the presence of TI, was found to be sufficient to cause significant accumulation of hemorrhagic luminal fluid in duodenal, jejunal, or ileal loops treated for 6 h with purified CPB, while no damage was observed in corresponding loops receiving CPB (no TI) or TI alone. In contrast to the CPB sensitivity of the small intestine, the colon was not affected by 6 h of treatment with even 90 μg of purified CPB whether or not TI was present. Time course studies showed that purified CPB begins to induce small intestinal damage within 1 h, at which time the duodenum is less damaged than the jejunum or ileum. These observations help to explain why type B and C infections primarily involve the small intestine, establish CPB as a very potent and fast-acting toxin in the small intestines, and confirm a key role for intestinal trypsin as an innate intestinal defense mechanism against CPB-producing C. perfringens isolates.


2012 ◽  
Vol 80 (12) ◽  
pp. 4354-4363 ◽  
Author(s):  
Menglin Ma ◽  
Jihong Li ◽  
Bruce A. McClane

ABSTRACTClostridium perfringenstype C strains are the only non-type-A isolates that cause human disease. They are responsible for enteritis necroticans, which was termed Darmbrand when occurring in post-World War II Germany. Darmbrand strains were initially classified as type F because of their exceptional heat resistance but later identified as type C strains. Since only limited information exists regarding Darmbrand strains, this study genetically and phenotypically characterized seven 1940s era Darmbrand-associated strains. Results obtained indicated the following. (i) Five of these Darmbrand isolates belong to type C, carry beta-toxin (cpb) and enterotoxin (cpe) genes on large plasmids, and express both beta-toxin and enterotoxin. The other two isolates arecpe-negative type A. (ii) All seven isolates produce highly heat-resistant spores withD100values (the time that a culture must be kept at 100°C to reduce its viability by 90%) of 7 to 40 min. (iii) All of the isolates surveyed produce the same variant small acid-soluble protein 4 (Ssp4) made by type A food poisoning isolates with a chromosomalcpegene that also produce extremely heat-resistant spores. (iv) The Darmbrand isolates share a genetic background with type A chromosomal-cpe-bearing isolates. Finally, it was shown that both thecpeandcpbgenes can be mobilized in Darmbrand isolates. These results suggest thatC. perfringenstype A and C strains that cause human food-borne illness share a spore heat resistance mechanism that likely favors their survival in temperature-abused food. They also suggest possible evolutionary relationships between Darmbrand strains and type A strains carrying a chromosomalcpegene.


2009 ◽  
Vol 77 (12) ◽  
pp. 5291-5299 ◽  
Author(s):  
Francisco A. Uzal ◽  
Juliann Saputo ◽  
Sameera Sayeed ◽  
Jorge E. Vidal ◽  
Derek J. Fisher ◽  
...  

ABSTRACT Clostridium perfringens type C isolates cause enterotoxemias and enteritis in humans and livestock. While the major disease signs and lesions of type C disease are usually attributed to beta toxin (CPB), these bacteria typically produce several different lethal toxins. Since understanding of disease pathogenesis and development of improved vaccines is hindered by the lack of small animal models mimicking the lethality caused by type C isolates, in this study we developed two mouse models of C. perfringens type C-induced lethality. When inoculated into BALB/c mice by intragastric gavage, 7 of 14 type C isolates were lethal, whereas when inoculated intraduodenally, these strains were all lethal in these mice. Clinical signs in intragastrically and intraduodenally challenged mice were similar and included respiratory distress, abdominal distension, and neurological alterations. At necropsy, the small, and occasionally the large, intestine was dilated and gas filled in most mice developing a clinical response. Histological changes in the gut were relatively mild, consisting of attenuation of the mucosa with villus blunting. Inactivation of the CPB-encoding gene rendered the highly virulent type C strain CN3685 avirulent in the intragastric model and nearly nonlethal in the intraduodenal model. In contrast, inactivation of the genes encoding alpha toxin and perfringolysin O only slightly decreased the lethality of CN3685. Mice could be protected against lethality by intravenous passive immunization with a CPB antibody prior to intragastric challenge. This study proves that CPB is a major contributor to the systemic effects of type C infections and provides new mouse models for investigating the pathogenesis of type C-induced lethality.


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