Perfringens Isolates Research Articles

Gastrointestinal Impaction and Necrotic Enteritis in a Backyard Chicken.

The carcass of a 4-mo-old, female, mixed-breed backyard chicken was submitted for postmortem evaluation and diagnostic workup. The bird was previously presented to a veterinary clinic because of chronic weight loss and loose stool, and was euthanized before submission to the California Animal Health and Food Safety, Turlock lab. On gross examination, the proventriculus, gizzard, and duodenum were markedly distended and impacted with a mixture of fibrous plant material, cereal grain, and litter material. The koilin layer of the gizzard was eroded. There were multifocal to coalescing, 0.2-1-cm diameter white nodules on the serosal surface of the duodenal loop and lesions extended into the distal jejunum. The duodenum had multifocal, transmural, umbilicated, and ulcerated mucosal lesions, which were covered with a white pseudomembrane. Microscopically, there was segmental, transmural necrosis of the intestinal wall with diffuse sloughing of villi epithelium and accumulation of fibrino-hemorrhagic exudate with numerous bacterial colonies in the lumen. The gross and microscopic findings were indicative of gastrointestinal impaction and necrotic enteritis. Proliferation of Clostridium perfringens within the intestine was demonstrated by anaerobic bacterial culture, intestinal gram stains, and immunohistochemistry. The C. perfringens isolate was type F (encoding the gene for alpha toxin -cpa- and for enterotoxin -cpe) by PCR toxinotyping. Overgrowth of C. perfringens was likely exacerbated by the rough fibrous forage and highly fermentable grain diet. To our knowledge, gastrointestinal impaction concurrent with necrotic enteritis has not been described in backyard chickens. In addition, to our knowledge, C. perfringens type F has not been associated with necrotic enteritis in chickens.

Molecular identification and sequence analysis of Clostridium perfringens virulence genes isolated from sheep and goats

Clostridium perfringens (C. perfringens) belongs to the family of Clostridiaceae and produces a wide range of toxins (four major and a variety of minor toxins). Some toxins associated with virulence have been shown to participate in the pathogenesis of enteric diseases in sheep, goats, and other animals. The aim of this study was to determine the presence of minor virulence genes and their genetic diversity in the various toxinotypes of C. perfringens isolates. About 84 isolates collected from sheep and goat flocks were examined and sequenced for the presence of minor virulence genes. Results showed that PFO and cpb2 were found in 79 out of 84 (94%), cpe was identified in 29 out of 84 (35%) and the presence of tpeL was confirmed in 28 out of 84 (33%) isolates, while none of the isolates were identified as carrying the netB gene. This study shows that the prevalence of genes varied among various types of C. perfringens isolates and also sheep and goat samples, furthermore these findings change the toxinotypes of isolates based on a modified scheme of toxinotype, which incorporated CPE and NetB toxins. The results of this study showed that the dominant minor virulence genes were PFO and cpb2 and the occurrence of cpe and tpeL genes was also diverse. DNA sequencing revealed approximately a sequence similarity of 97-100% with the GenBank database and 3 motation was found in sequence analysis.

No change in avilamycin (Surmax® Premix) minimum inhibitory concentration for Clostridium perfringens isolates recovered from poultry up to 7 years post-approval in Canada.

Clostridium perfringens, the causative agent of necrotic enteritis (NE) in chickens, has an enormous economic impact on global broiler production. The non-medically important antibiotic avilamycin was approved in Canada in 2014 to prevent and control NE in broiler chickens. To compare avilamycin susceptibility in C. perfringens isolates collected pre- and 7 years post-avilamycin approval in Canada and determine the avilamycin resistance mutation frequency rate in C. perfringens. The MICs of avilamycin were determined for 89 strains of C. perfringens recovered from clinically relevant NE field cases pre-avilamycin approval between 2003 and 2013 (n = 50) and post-avilamycin approval between 2014 and 2021 (n = 39) across Canada. For determining the mutant prevention concentration (MPC) of avilamycin for C. perfringens strains, a strain with avilamycin MIC of 1 mg/L was randomly selected. MIC studies showed no difference in avilamycin susceptibility in pre-avilamycin and post-avilamycin isolates (MIC50/90: pre-avilamycin approval 2/2 mg/L and post-avilamycin approval 1/2 mg/L). The MPC was 8 × MIC (8 mg/L) for the selected strain. These findings suggest that the susceptibility of C. perfringens strains to avilamycin was not impacted by its continued use in the 7 years following its approval in Canada. Avilamycin, a non-medically important antibiotic, poses no threat to human health regarding cross-resistance or co-selection of other medically important antibiotics. These factors make avilamycin an appropriate choice for continued use in broiler chickens to prevent and control NE without increased antimicrobial resistance concerns.

Clostridium perfringens in Broiler Chickens: Isolation, Identification, Typing, and Antimicrobial Susceptibility

Necrotic enteritis (NE) is a common worldwide poultry disease caused by the bacterium of Clostridium perfringens (C. perfringens) which has significant economic losses in the poultry industry as well as the cost of treatment and preventive measures. The current study was conducted to evaluate the incidence of NetB toxin positive in C. perfringens on different farms in Egypt. In the years 2020 and 2021, on industrial broiler farms (15-45 days- old), 100 intestinal samples were collected consisting of 30 healthy Ross broiler chickens and 70 unhealthy Ross broiler chickens. Culture and biochemical characterization (Catalase, urease, sugar fermentation, gelatin liquefaction, nitrate reduction, and lecithinase reaction tests) confirmed that C. perfringens was isolated at a rate of 10% (3/30) from apparently healthy broiler chickens and 40% from unhealthy broiler chickens. Thirty-one isolates were tested for toxigenicity and typing by ELISA kits and the results showed that 80% of the isolates from unhealthy broiler chickens were C perfringens type A alpha-toxin (toxigenic), 20% were non-toxigenic, and 66.7% isolates from apparently normal broiler chickens were toxigenic. The same thirty-one (44%) C. perfringens isolates were detected by PCR to investigate the presence of the NetB toxin gene in apparently healthy and unhealthy broilers and subsequently detect the role of NetB toxin in inducing NE. Of the samples, 82% of the isolates from unhealthy chicks were found to incode NetB gene, while none of the isolates from healthy broiler chickens had NetB. Clostridium perfringens showed sensitivity to amoxicillin, amoxicillin with clavulanic acid and ampiclox, intermediate for ofloxacin, and high resistance to cephalexin, streptomycin, colistin sulfate, erythromycin, sulfa trimethoprim, gentamycin, and oxytetracycline. The present study revealed the importance of NetB gen in the appearance of clinical signs of NE in broiler chickens. Keywords: Alpha toxin, Antibiotic sensitivity test, Clostridium perfringens, Necrotic enteritis, NetB

Antimicrobial potential of myricetin-coated zinc oxide nanocomposite against drug-resistant Clostridium perfringens

BackgroundClostridium perfringens (C. perfringens) is an important pathogen in livestock animals and humans causing a wide array of systemic and enteric diseases. The current study was performed to investigate the inhibitory activity of myricetin (MYR), polyvinyl alcohol (PVA), and zinc oxide (ZnO) nanocomposite against growth and α-hemolysin of C. perfringens isolated from beef meat and chicken sources.ResultsThe overall occurrence of C. perfringens was 29.8%. The prevalence of C. perfringens was higher in chicken (38.3%) than in beef meat products (10%). The antimicrobial susceptibility testing revealed that C. perfringens isolates exhibited high resistance levels for metronidazole (93%), bacitracin (89%), penicillin G (84%), and lincomycin (76%). Of note, 1% of C. perfringens isolates were pandrug-resistant (PDR), 4% were extensive drug-resistant (XDR), while 91% were multidrug-resistant. The results of broth microdilution technique revealed that all tested C. perfringens isolates were susceptible to MYR-loaded ZnO/PVA with minimum inhibitory concentrations (MICs) ranged from 0.125 to 2 µg/mL. Moreover, the MYR either alone or combined with the nanocomposite had no cytotoxic activities on chicken red blood cells (cRBCs). Transcriptional modifications of MYR, ZnO, ZnO/PVA, and ZnO/PVA/MYR nanocomposite were determined, and the results showed significant down-regulation of α-hemolysin fold change to 0.5, 0.7, 0.6, and 0.28, respectively compared to the untreated bacteria.ConclusionThis is an in vitro study reporting the antimicrobial potential of MYR-coated ZnO nanocomposite as an effective therapeutic candidate against C. perfringens. An in vivo approach is the next step to provide evidence for applying these alternatives in the treatment and prevention of C. perfringens-associated diseases.

Postpartum clostridial gangrenous metritis in 12 dairy goats in France.

Clostridial infections in goats have been associated frequently with enteric diseases or gas gangrene but very rarely with the reproductive system. We describe here 12 cases of fatal postpartum gangrenous metritis in does associated with infection by several clostridial species. Clinically, these cases were characterized by rapid onset of hyperthermia followed by death after kidding. On postmortem examination, the uteri appeared to be necrotic and were hemorrhagic and edematous. Microscopically, the uteri had diffuse coagulative necrosis, edema, hemorrhage, and fibrinous thrombi with intralesional gram-positive rods. Clostridium perfringens was isolated from 7 of 9 uterine samples cultured, and C. perfringens, C. septicum, C. novyi, or C. chauvoei were demonstrated by immunohistochemistry (IHC) in the 5 cases examined. IHC for Paeniclostridium sordellii was negative in all 5 cases. PCR performed on 3 of the C. perfringens isolates was positive for alpha toxin and perfringolysin, identifying these isolates as type A. Clostridial infection should be considered in cases of postpartum gangrenous metritis of does.

Necrotic enteritis in a commercial turkey flock coinfected with hemorrhagic enteritis virus.

Four turkeys from a commercial flock with acutely elevated mortality levels were submitted for postmortem examination and diagnostic workup. No clinical signs had been observed before death. On gross examination, hemorrhage and necrosis were present throughout the intestinal tracts, and the spleens were markedly enlarged and speckled. Microscopically, numerous, large basophilic-to-amphophilic intranuclear inclusion bodies were observed in mononuclear cells of the spleen and the lamina propria of the small intestine. In addition, there were lesions of diffuse villus blunting and necrosis of the small intestine, with large numbers of rod-shaped bacteria adhered to the epithelium and in the intestinal lumen. Hemorrhagic enteritis virus (HEV) infection was confirmed via PCR on the spleen. Clostridium perfringens was demonstrated in the small intestine by anaerobic culture and immunohistochemistry. The C. perfringens isolate was type F by PCR and, to our knowledge, necrotic enteritis in turkeys has not been described in association with C. perfringens type F infection.

Determination of Antimicrobial Susceptibility of Clostridium Perfringens Strains Isolated from Healthy and Diseased Ostriches (Struthio camelus)

Gastrointestinal diseases are considered the most prevalent and economically considerable diseases in the ostrich breeding industry, in which necrotic enteritis caused by C. perfringens induces high mortality, especially in ostrich chicks. Several antimicrobial agents are used to prevent enteric diseases, enhancing growth rate and increasing feed conversion ratio. This procedure results in a high prevalence of resistance among enteric bacteria with the possibility of a consequent emergence of antibiotic resistance in zoonotic enteropathogens. This study determined the susceptibility of C. perfringens strains isolated from the intestine and faeces of disease and healthy ostriches in southeast Iran to 8 antimicrobial agents. A total of 40 C. perfringens isolates were collected from several ostrich flocks and were tested using the broth microdilution method. The susceptibility of obtained isolates to antibiotics was as follows: ceftriaxone (80%), cefazolin (77.5%), florfenicol (72.5%), tetracycline (62.5%), penicillin (47.5%), sulfadiazine (20%), sulfadimidine (7.5%) and neomycin (7.5%). In conclusion, C. perfringens strains isolated from ostriches should be tested and monitored for antibacterial susceptibility patterns. The present study is the first to determine the antimicrobial susceptibility of C. perfringens isolated from ostrich.

Detection of Clostridium perfringens types through genetic profiling and mouse neutralisation test.

The aim of this study was to detect the types of C. perfringens using PCR and mouse neutralisation test (MNT) and find the genetic profile of virulence factors tpeL and netB isolated from animal samples in Iran. For this purpose, 46 C. perfringens isolates were tested using MNT. Detection was also performed using 16S rRNA-PCR and multiplex PCR for alpha, beta, epsilon and iota toxins. For tpeL and netB gene profiling, separate PCR experiments were carried out. MNT detected that all isolates were C. perfringens type A. The same results were obtained in 16SrRNA-PCR and multiplex-PCR. Based on the obtained results, the molecular test was 100% consistent with MNT. Samples were positive for tpeL and netB genes in 52.1% and 60.8% isolates, respectively. Overall, four genetic virulence factor profiles were found in C. perfringens type A isolates.

Composting: A biosecurity measure to maximize the benefit of broilers̕ litter.

This study was conducted to evaluate the effect of composting on the count of Salmonella spp., Clostridium perfringens, and New Castle virus (NDV) isolated from broilers' litter. Moreover, to verify the impact of compost thermal stress on the expression of thermal genes harbored in the isolated bacteria. The prevalence of enteric aerobic and anaerobic infections by Salmonella spp., C. perfringens, and viral infections by NDV were investigated in litter samples collected from 100 broiler flocks by conventional methods and polymerase chain reaction. The samples were positive for Salmonella spp., C. perfringens, and NDV, with prevalence rates of 60%, 55%, and 30%, respectively. An experiment to study the effect of compost on the microbiological quality of litter was applied using five compost heaps with an initial average count of Salmonella typhimurium (3.2 × 105CFU CFU/gm), C. perfringens (6.4 × 105 CFU/gm), and an average titer NDV (105.5 embryo infectious dose50/gm). The microbiological count of heaps after 15 days of composting revealed a reduction in the count of S. typhimurium and C. perfringens by 4 log10 CFU/gm and 3 log10 CFU/gm, respectively. Moreover, the hemagglutinating test revealed no detection of NDV after 15 days of composting. A high degree of downregulation of expression of the thermal genes, dnaK in S. typhimurium isolates and cpe gene in C. perfringens isolates, was detected by quantitative reverse transcription PCR. The reduction of pathogen counts, the simplicity, and the low cost associated with composting for only 15 days advocate the recommendation for raising awareness of composting as a routine biosecurity measure to prevent the spreading of infection and promote its safe use in agribusiness.

Toxin genotypes of Clostridium perfringens isolates from common quail (Coturnix coturnix) with or without acute necrotic enteritis

Clostridial diseases are one of the foremost causes of mortality in quails which occur by Clostridium colinum, Clostridium perfringens (C. perfringens), and Clostridium sordellii. C. perfringens genotypes responsible for quail enteritis are not well understood. In this study, the prevalence of C. perfringens genotypes was investigated in common quail (Coturnix coturnix) farms that suffered from acute necrotic enteritis (diarrhoeic) and compared with healthy (non-diarrhoeic) quails. Toward this end, C. perfringens isolates were collected and genotyped for 16s rRNA, cpa, cpb, cpb2, etx, iap, cpe, netB, and tpeL genes, using PCR. It was revealed that 42, 23, and 19 isolates belonged to toxinotypes A, F, and G, respectively, and the other toxinotypes were not obtained. The recovery ratio of C. perfringens from diarrhoeic farms roughly doubled in non-diarrhoeic farms (40.0% versus 21.5%, p = 0.03). Also, we observed a high isolation ratio of the cpb2 genotype (90.48%), which was significantly eminent in the diarrhoeic group (94.2%, p < 0.05). Although the prevalence of tpeL genes was low (15.48%), there was an interesting relationship between this gene and cpb2, so we did not obtain cpb2-tpeL-. This study showed the prevalence of types A, F, and G of C. perfringens in quail enteritis. Also, we reported tpeL+C. perfringens strains in quail for the first time and its frequent co-occurrence with the cpb2 gene. These results highlight the necessity of more accurate investigations of the C. perfringens genotype in different hosts to verify the exact role of these toxins in quail enteritis.

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.

Antimicrobial susceptibility and multilocus sequence typing of Clostridium perfringens isolated from yaks in Qinghai-Tibet plateau, China.

Clostridium perfringens (C. perfringens) is an opportunistic pathogen that cause necrotic enteritis, food poisoning and even death in animals. In this study, we explored the prevalence, antibiotic resistance and genetic diversity of Clostridium perfringens isolated from yak in the Qinghai-Tibet plateau, China. A total of 744 yak fecal samples were collected and assessed for toxin genes, antimicrobial susceptibility and multilocus sequence typing (MLST). Results indicated that 144 out of 744 (19.35%) yak fecal samples were tested to be positive for C. perfringens, 75% (n = 108, 108/144) were C. perfringens type A, 17.36% (n = 25, 25/144) were C. perfringens type C, 2.78% (n = 4, 4/144) were C. perfringens type D, and 4.86% (n = 7, 7/144) were C. perfringens type F. In addition, 2.78% (n = 4, 4/144) of the isolates were positive for cpb2 toxin gene. Antimicrobial susceptibility testing revealed that 98.61% (142/144) of the isolates showed multiple-antibiotic resistance. According to MLST and phylogenetic tree, 144 yak-derived C. perfringens isolates had an average of 12.95 alleles and could be divided into 89 sequence types (STs) and clustered in 11 clonal complexes (CCs). The most of isolates belong to type A with a considerable genetic diversity, having Simpson index up to 0.9754. MLST and phylogenetic analysis showed that the isolates under the same clade came from multiple regions. Cross-transmission among isolates and interconnectedness were observed in the genetic evolution. According to the study, the most of the isolates exhibited broad-spectrum antibacterial resistance, diverse alleles, and multiple lethal toxin genes of C. perfringens.

Molecular epidemiology and genetic characterization of Clostridium perfringens infections in lambs

Clostridium perfringens is gram positive bacterium, wide spread in environment causing various diseases in animals and human. The current study was conducted to indentify the genetic identity of C. perfringens isolates from lambs from Egypt. Using specific primers amplifying genes associated to the toxins produced by C. perfringens, multiplex PCR was used to confirm C. perfringens in 87 out of 140 samples were collected from diseased and suspected lambs. The isolates were classified as type A in 49.4%, type B in 31.1% and type D in 19.5% of isolates. The phylogenetic analysis for the partial sequences of C. perfringens strains based on plc gene, cpb gene and etx gene obtained in the present study showed high degree of similarity with other sequences of C. perfringens strains in GenBank, isolating from sheep from Egypt and other countries. According to the findings, lambs with enterotoxaemia more frequently have C. perfringens type A and an efficient hygienic control program is necessary to reduce the infection spreading among susceptible animals.

Prevalence, molecular characterization, and antimicrobial resistance profile of Clostridium perfringens from India: A scoping review

Clostridium perfringens is one of the most important foodborne pathogens that causes histotoxic diseases and intestinal infections in both humans and animals. The present scoping review has been designed to analyze the literature published during 2000–2021 from India on the prevalence, molecular characterization, and antimicrobial resistance profile of C. perfringens isolates recovered from humans, animals, animal-based foods, and associated environmental samples. The peer-reviewed articles retrieved from four electronic databases (Google Scholar, PubMed, Science Direct, and Web of Science) were assessed using PRISMA-ScR guidelines. A total of 32 studies from India were selected on the basis of their relevance and inclusion criteria. The overall prevalence of C. perfringens among domestic animals having history of clinical symptoms and among healthy animals was found to be 65.8% (508/772) and 42.8% (493/1152), respectively. The pathogen was also detected in clinically affected wild animals (75%), healthy wild animals (35.4%), and captive birds (24.5%). The detection of C. perfringens among poultry having necrotic enteritis and among healthy birds was found to be 66.8% (321/480) and 25.6% (80/312), respectively. The detection of pathogen among animal-based foods (i.e., meat, milk, and fish and their products) and environmental samples depicted a prevalence of 20.8% (325/1562) and 30.2% (23/76), respectively. However, the prevalence of C. perfringens among humans having history of diarrhea and among healthy humans was found to be 25% (70/280) and 23.2% (36/155), respectively. The genotyping of C. perfringens isolates revealed that toxin type A was found to be the most prevalent genotype. Along with the alpha toxin gene (cpa), beta (cpb), epsilon (etx), iota (itx), enterotoxin (cpe), beta-2 toxin (cpb2), and NetB (netB) toxins were also detected in different combinations. Antimicrobial resistance profile of C. perfringens isolates recovered from different sources demonstrated that the highest resistance was detected against sulphonamides (76.8%) and tetracycline (41.3%) by phenotypic and genotypic detection methods, respectively. Comprehensive scientific studies covering different geographical areas at the human-animal-environment interface are crucial to generalize the real magnitude of C. perfringens-associated problem in India and for establishing a reliable database.

Prevalence and genotypic characterization of Clostridium perfringens associated with goat (Capra hircus) enterotoxemia in Southeast Iran

Goat enterotoxaemia, a worldwide disease with a high case-fatality rate (up to 100%), is mainly caused by Clostridium perfringens (C. perfringens) toxinotypes D, C, and B, respectively. Here, the prevalence and genotypic characteristics of C. perfringens in goats were investigated in southeast Iran during 2016–2020. In total, 5300 goats from 57 herds were examined, and 112 strains of C. perfringens were isolated from 142 goats (79 dysenteric and 63 healthy goats with a history of enterotoxemia). PCR tests were conducted on isolates using the 16SrRNA, cpa, cpb, etx, iap, cpe, and netb gene primers. Toxinotyping of C. perfringens isolates revealed that the existing toxinotypes were type D (26.8%), followed by types A and F (25.9% for each), then type B (15.2%), and type C (6.2%). The overall prevalence of C. perfringens at the animal and farm levels was 19.0% and 36.8%, respectively. The isolation rate of C. perfringens from dysenteric goats (30.4%) was significantly higher than that of the healthy goats (p = 0.000). Among the isolates, 44.6% (50 of 112) were PCR positive for the cpe gene. The majority of cpe-positive isolates were characterized as type F (58.0%), followed by types D (28.0%), B (8.0%), and C (6.0%). Dysenteric goats were most likely to yield cpe-positive isolates (94.1%). Our results show the high prevalence of Clostridium perfringens toxinotypes in goats and, for the first time, indicate the presence of type F and cpe-positive type B strains in goat enterotoxemia.

Outbreaks of Acute Necrotic Enteritis and Haemolytic Crisis and Renal Disease Associated with Clostridium perfringens in Captive Toucans (Ramphastos spp)

Four toco toucans (Ramphastos toco), one channel-billed toucan (Ramphastos vitellinus) and one white-throated toucan (Ramphastos tucanus) died in two disease outbreaks in the same aviary in 2011 and 2016. Post-mortem examination revealed diffuse necrotic enteritis (NE) as the cause of death of five of these six birds. Clostridium perfringens was identified by culture and real-time multiplex PCR for C. perfringens α-, β-, ε- and ι-toxin genes in ligated intestine of one toucan from each outbreak. At another aviary, two keel-billed toucans (Ramphastos sulfuratus) died peracutely from severe haemolytic crisis with haemoglobinaemic nephrosis and cholestasis and acute tubulointerstitial nephritis. Mild NE was present in these birds and C. perfringens was demonstrated in liver by bacterial culture and real-time multiplex PCR for C. perfringens α-, β-, ε- and ι-toxin genes. To the authors' knowledge, this is the first description of outbreaks of NE associated with C. perfringens in captive toucans. Although haemolytic crisis has been reported in humans with C. perfringens type A septicaemia and hepatic abscesses, this presentation appears not to have been described in C. perfringens infections in toucans or other avian species. The factors causing C. perfringens proliferation and disease in the toucans were not identified. PCR for C. perfringens NetB toxin and enterotoxin genes performed retrospectively on one of the C. perfringens isolates from the second outbreak and on paraffin-embedded tissues from one dead toucan from the first outbreak was negative. With the current C. perfringens toxin typing scheme, C. perfringens type A was identified in the first two outbreaks.

Clostridium perfringens Associated with Foodborne Infections of Animal Origins: Insights into Prevalence, Antimicrobial Resistance, Toxin Genes Profiles, and Toxinotypes.

Simple SummaryRecently, a crisis derived from foodborne infections, especially those are associated with food from animal origins caused by Clostridium perfringens (C. perfringens), has worsened. Unfortunately, the solutions to this crisis were restricted by an evolved resistance to antimicrobial agents. Therefore, we try to warn the world population about the hazards associated with this pathogen. The high diversity and polyclonality of C. perfringens strains depicted in our study show the urgent need to advance programs to control C. perfringens associated with foodborne infections. Additionally, the findings presented in this study are also of clinical importance, assisting in understanding the prevalence, origin, reservoir, and evolution of antimicrobial resistance of C. perfringens for establishing the control of this pathogen.Several food-poisoning outbreaks have been attributed to Clostridium perfringens (C. perfringens) worldwide. Despite that, this crisis was discussed in a few studies, and additional studies are urgently needed in this field. Therefore, we sought to highlight the prevalence, antimicrobial resistance, toxin profiles, and toxinotypes of C. perfringens isolates. In this study, 50 C. perfringens isolates obtained from 450 different animal origin samples (beef, chicken meat, and raw milk) were identified by phenotypic and genotypic methods. The antimicrobial susceptibility results were surprising, as most of the isolates (74%) showed multidrug-resistant (MDR) patterns. The phenotypic resistance to tetracycline, lincomycin, enrofloxacin, cefoxitin/ampicillin, and erythromycin was confirmed by the PCR detections of tet, lnu, qnr, bla, and erm(B) genes, respectively. In contrast to the toxinotypes C and E, toxinotype A prevailed (54%) among our isolates. Additionally, we found that the genes for C. perfringens enterotoxin (cpe) and C. perfringens beta2 toxin (cpb2) were distributed among the tested isolates with high prevalence rates (70 and 64%, respectively). Our findings confirmed that the C. perfringens foodborne crisis has been worsened by the evolution of MDR strains, which became the prominent phenotypes. Furthermore, we were not able to obtain a fixed association between the toxinotypes and antimicrobial resistance patterns.

Toxinotyping of Clostridium perfringens Strains Recovered from U.S. Turkeys with Necrotic Enteritis.

Necrotic enteritis (NE) is a serious disease of chickens and turkeys that causes significant economic losses to the poultry industry. On the basis of studies in chickens, Clostridium perfringens type G is considered by many to be the cause of NE in poultry. However, studies on isolates from Finnish and Italian turkeys with NE revealed that the vast majority were C. perfringens type A, and very few were C. perfringens type G. We therefore examined 74 C. perfringens isolates from U.S. turkeys with NE; 98% were type A and only 1% was type G. This result confirms that different C. perfringens types are involved in NE in turkeys when compared with chickens. We also examined the turkey isolates for other toxin genes associated with enteritis in various animal species, namely tpeL, cpb2, cpe, netE, netF, and netG. The tpeL gene, which has been associated with enhanced virulence of C. perfringens in chickens, was only found in 1% of turkey NE isolates. The cpe gene, which encodes C. perfringens enterotoxin (a major cause of food poisoning and non-foodborne C. perfringens-mediated diarrhea in humans) was also found in only 1% of our turkey NE isolates. Although cpb2, which encodes for the beta2 toxin, was found in 73% of our NE isolates, it has also been found in similar percentages of isolates from turkeys with normal intestine. The netE, netF, and netG genes were not detected among our C. perfringens isolates from turkeys.

The Broad Host Range Phage vB_CpeS_BG3P Is Able to Inhibit Clostridium perfringens Growth.

Clostridium perfringens is an important pathogen for both humans and animals, causing human foodborne disease and necrotic enteritis in poultry. In the present study, a C. perfringens-specific phage, vB_CpeS_BG3P (designated as BG3P hereafter), was isolated from chicken farm sewage. Both electron microscopy and phylogenetic analysis suggested that phage BG3P is a novel phage belonging to Siphoviridae family. Phage BG3P exhibited a broad host range against different C. perfringens isolates (90.63% of strains were infected). Sequencing of the complete genome revealed a linear double-stranded DNA (43,528 bp) with 28.65% GC content. After sequence analysis, 73 open reading frames (orfs) were predicted, of which only 13 were annotated with known functions. No tRNA and virulence encoding genes were detected. It should be noted that the protein of orf 15 has 97.92% homology to C. perfringens-specific chloramphenicol resistance protein, which has not been reported for any C. perfringens phage. Phylogenetic analysis of the ssDNA binding protein demonstrated that this phage is closely related to C. perfringens phages phiSM101 and phi3626. In considering future use as an antimicrobial agent, some biological characteristics were observed, such as a good pH (3–11) stability and moderate temperature tolerance (<60 °C). Moreover, bacteriophage BG3P showed a good antimicrobial effect against C. perfringens liquid cultures. Thus, phage treatment with MOI ≥ 100 completely inhibited bacterial growth compared to untreated cultures. Although phage BG3P shows good lytic efficiency and broad host range in vitro, future development and application may need to consider removal of the chloramphenicol-like resistance gene or exploring its lysin for future antibacterial applications.