جستجوی مقالات مرتبط با کلیدواژه « Clostridium perfringens » در نشریات گروه « دامپزشکی »

Foot and mouth disease (FMD) and enterotoxemia are important diseases of hoofed animals. Vaccination against livestock pathogens, especially these two diseases, plays a key role in the prevention and control of these diseases. The use of combined vaccines with the aim of creating a better immune response and producing cheaper vaccines is a great contribution to Vaccine industry. This research aimed to compare the immunogenicity of FMD (O) and Clostridium perfringens type B toxoid along with adjuvant (MF59) and Montanide (ISA70) to create the best immunogenicity. To investigate the immune responses of vaccines, it was injected into an animal model, and the antibody titer was measured by enzyme-linked immunosorbent assay (ELISA) test and VN antibody titer. The results showed that the formulation with MF59 adjuvant brought more stable immunogenicity against FMD and Clostridium perfringens type B, and the length of the immunogenicity period also increased significantly. Therefore, the combined vaccine (Clostridium perfringens + FMD) could play a major role invaccine industry as an alternative vaccine against Clostridium perfringens and FMD in livestock.

Concurrent with an increase in the human population on the earth, more than ever, the creation of energy and maintenance of health is necessary, and nowadays, various sources of energy supply are being developed. The general global view in this regard is to provide protein and energy from available and cheap sources. Iran is no exception to this general rule, only in the field of ensuring the health of livestock resources every year, about 10 tons of peptone is needed for producing clostridial vaccines. Vermicomposting worms (Esienia fetida) with high protein percentages and rapid reproductions are a suitable source for peptone production. Based on this, the vaccine strain of Clostridium perfringens type D cultivated in two different media contain peptone produced from worms and meat peptone. The growth rate, epsilon toxin (ETX), and alpha toxin (CPA) of Cl. perfringens have been compared in two media. The results showed that the growth rate of bacteria in the worm peptone medium in 48 h was 22% higher than that of the meat peptone. Additionally, the activity of alpha toxin (phospholipase C) was in worm peptone 15% higher than meat peptone during 80 min of measurement. Regarding epsilon toxin lethality, all three mice of the N-worm peptone group died, while all three mice of the meat peptone group survived even 72 h after injection. The average survival time of mice in the N-worm peptone group was 1700 min. Therefore, we suggest the worms' protein is more suitable than industrial meat in peptone production for vicinal propose. To eliminate the need for hydrolyzed protein in the production of vaccines in the future, we suggest an increase in the fields of employment and the development of fertilizer and worm farms in Iran.

Clostridial enteric diseases, called enterotoxemia, are caused by Clostridium perfringens toxinotypes in sheep and other ruminants. This study aimed to describe the molecular characterization of C. perfringens isolates in diarrhoeic sheep (Ovis aries) flocks in the southeast of Iran. Fecal/intestinal samples were collected from diarrhoeic (n=116), dead (n= 13), and healthy (n=63) sheep over four years (2016-2020) and subjected to bacteriological and molecular examinations. The C. perfringens isolates were typed by polymerase chain reaction targeting genes, namely 16SrRNA, CPA, CPB, ETX, IAP, CPE, and NetB. The overall prevalence of C. perfringens was 28.6% among the studied sheep, and there was a significant relationship between its isolation rate and diarrhea (P<0.001). The C. perfringens isolation rate also decreased with animal age (P=0.012) and was significantly higher in late winter and spring (P=0.000). The most prevalent toxinotypes were types A (52.4%), D (22.2%), and F (18.5%), in that order. Moreover, C, G, and B types were found in 4.2%, 1.6%, and 1.1% of the isolates, respectively, and no type E was detected. The CPE gene was detected in 32.3% of all isolates, and the diarrhoeic sheep were most likely to yield CPE+ strains of C. perfringens (93.1%). These findings highlight the importance of CPE+ strains of C. perfringens in sheep enteritis and suggest that the high presence of type F needs to be considered in new clostridial vaccines containing this toxinotype. It is noteworthy that the present study reported the isolation of C. perfringens type F, type G, and the CPE+ strains of type B from diarrhoeic sheep for the first time.

In recent years, a nanoparticle-based strategy has shown that non-denatured protein toxins can be used to enhance the appropriate immune response. Once the toxin reacts between the nanoparticles and the protein (toxin), it loses its toxicity because it does not attach to its ligand at the cell surface. The results of the nanoparticle and toxin complex show that the nanoparticles facilitate the internal release of the toxin. Clostridium perfringens beta toxin is produced by Clostridium perfringens type B and C, and diarrhea is the most important disease caused in newborn lambs. When beta toxin forms a complex with nanoparticles, the reaction between the toxin and the nanoparticle leads to the formation of a new form of nanoparticle in which the toxin loses its lethality due to its involvement; therefore, it becomes a toxoid. The nanoparticles used in this research are of poly lactic-co-glycolic acid (PLGA) type, one of the most developed biodegradable polymers. This study aimed to isolate and purify Clostridium perfringens beta toxin and produce its complex with PLGA nanoparticles to form a non-toxic structure. In this study, Clostridium perfringens beta toxin type B was isolated using ammonium sulfate precipitation and gel filtration chromatography. Toxin assay was performed in vivo (lethal dose [LD50]) and in vitro by sodium dodecyl sulphate-polyacrylamide gel electrophoresis at each stage, and the quantity of purified toxin was calculated to be 10 mg/ml. Afterward, the beta toxin antigen was used as the basis for the preparation of nanotoxoid candidates with nanoparticle formulation. Moreover, the PLGA polymer and water-oil-water methods were used to fabricate nanoparticles. Under optimal conditions, nanoparticles without antigen with an average size of 100 nm and zeta potential of -23.28 mV, as well as nanoparticles containing antigen with an average size of 120 nm and zeta potential of -18.2 mV, were prepared. When nanoparticles are injected into mice with the beta toxin, the toxin becomes a toxoid with no toxicity effects, and it cannot bind to its receptors and reveal its effects. In this study, the mice showed mild symptoms in one case, and none of them died. The beta and PLGA toxin model could also be applied as a candidate to study the release and immunization of the target animal. In order to achieve antigen regulation using natural polymers, it is recommended to conduct a comparative study between nanoparticles based on natural polymers.

Clostridium perfringens commonly resides in the gastrointestinal tract and can survive in different environmental conditions. This pathogen produces several protein toxins including the potent ε-toxin which is classified as a category B toxin by the Centers for Disease Control and Prevention (CDC). In several studies, the induction of C. perfringens type C or D to produce toxins much more rapidly by close contact of bacteria with Caco-2 cells has been reported.

The effect of close contact of enterocyte-like Caco-2 cells with C. perfringens type D (vaccine strain) on the production time of ε- and α-toxins was studied.

During C. perfringens type D contact with Caco-2 cells for 5 h, ε- and α-toxins expressions (at 0, 2, and 5 h) were evaluated by a quantitative real-time PCR assay. Non-contacted bacteria with cells were included as the negative control in this research.

Bacterial contact with the Caco-2 cells induces a significant effect on the mean expression of the ε-toxin gene (etx) (P<0.05). Two h after contact, the highest level of gene expression was detected in the experimental group. Bacterial harvesting time, cell treatment, and their interactions did not affect significantly the mean expression of the α-toxin gene (cpa) (P>0.05).

According to the findings of the present study, 2 h of bacterial contact with Caco-2 cells could stimulate etx gene expression in the C. perfringens type D vaccine strain.

The high potential toxicity of epsilon toxin (Etx) produced by Clostridium perfringens (C. perfringens) type D, has made it the third most lethal clostridial toxin behind botulinum and tetanus, therefore, having a pure and concentrated Etx is very important.

The aim of this study was to purify Etx as pure as possible with an applicable, cost-effective, multistep purification protocol with the lowest and shortest time.

The purification of the Etx was carried out in multiple consecutive steps; ammonium sulfate precipi-tation, dialysis, size exclusion chromatography by G50, two concentration steps, and ultrafiltration. The Etx activity after different steps was evaluated by the minimum lethal dose (MLD) calculation, according to the standard oper-ating procedure. Toxin quantification was determined using Lowry technique, and its presence and specificity was tracked to identify pure Etx by SDS- PAGE and western blotting. Finally, the purity of Etx was evaluated by capil-lary electrophoresis.

The purified Etx formed a single band of about 32.9 kDa in SDS-PAGE and blotting. The pure Etx concentration was calculated to be 3.9 mg/ml and its MLD value was the dilution of 1/24000 after the ultrafiltration step. The presented purification processes to purify Etx resulted in ~ 87-fold concentration and 88.6% purity.

Due to this high Etx purity, the processes used in this study can provide the technical knowledge of toxin production in a larger industrial scale that can be used in development of clostridial toxoid vaccines, as well as quality control and/or diagnostic tests.

Wound infections are among public health problems worldwide. However, progress has been made in improving surgical techniques and antibiotic treatments. Misuse/overuse of antibiotics to prevent and treat bacterial infections eventually leads to increased bacterial resistance with rising incidences of multi-drug resistant (MDR) bacterial strains. The wider dissemination of antibiotics may ultimately result in ineffectiveness to antibiotic therapy, thereby complicating/graving the outcome of a patient. In the present study, a 60-year-old male patient having wound infection with MDR bacterium that ultimately required surgical amputation of the toe was investigated. For the confirmation of MDR bacterium, two culture media viz., MacConkeyAgar and Mueller Hinton Agar media were used. The sensitivity of the isolated strain for various antibiotics was tested using the disc diffusion method. The wound sample was found positive for Gram-positive bacterium that was identified as Clostridium perfringens. The bacterium was screened for 40 antibiotics, and among all the antibiotics, it was found sensitive for only Piperacillin/Tazobactam antibiotic combination. C. perfringens bacterium caused the gas gangrene in the infected wound part of the patient. Amputation of the gangrene –affected foot part was performed by surgery, and with good medical care, the person recovered fast. To the best of our knowledge, this is the first-ever report of MDRC. perfringens single isolate  harboring resistance against at least 40 antibiotics tested. More research is needed to develop really new and effective medicines that do not cross-react with antibiotics now in use and have robust activity against MDR organisms.

Clostridium perfringens is implicated in the etiology of some diseases including fatal enterotoxaemia. Determining dominant toxin types of this microorganism can be helpful in epidemiologic surveys and the formulation of more proper vaccines. To understand the pathogenicity of this bacterium, it seems necessary to describe the toxin and virulence genes content of strains involved in enterotoxaemia and other associated diseases. The current study aimed to isolate and type the toxins of C. perfringens in sheep with suspected enterotoxaemia in Fars province by culture-PCR and ELISA methods and to compare them to isolates of a healthy group. Samples of intestinal contents were collected from enterotoxaemia cases and a healthy group of sheep. The presence of alpha, beta, and epsilon toxins were evaluated by ELISA method. After culture and isolation of C. perfringens, toxin typing and screening of isolates for the presence of beta-2 and enterotoxin were performed by PCR method. C. perfringens was isolated from 102 of 167 suspected enterotoxaemia cases of sheep and from 22 of 50 healthy sheep. The PCR results showed that type A was the most prevalent toxin type in both groups, but according to ELISA type D was the dominant toxin type in the clinical group. The enterotoxin gene was detected in 10% of all isolates from healthy and suspected group isolates of types A and D. The beta-2 gene was identified in 35% and 63.6% of enterotoxaemia-associated isolates and isolates not associated with disease, respectively. In conclusion, Type D of C. perfringens was the dominant causative organism of fatal enterotoxaemia in sheep in Fars province.

Clostridium perfringens, as a bacterial agent causing foodborne illnesses, is of great importance in thefood industry. On the other hand, the increasing concern of antibiotic resistance is forcing humans to find an alternative toantibiotics.

This study aimed to evaluate the antimicrobial activity of the extracts of grape pomace, pistachio peel,and pomegranate pomace against Clostridium perfringens (C. perfringens) in the presence or absence of resistant starch(RS) as a prebiotic.

The RS (Fibersol-2) was purchased, and the extracts of grape pomace, pistachio peel, and pomegranate pomacewere prepared. The total phenolic content and tannin of extracts were determined by Folin-Ciocalteu and standard tannic acidmethod, respectively. The antimicrobial activity of the extract with or without RS was evaluated using the minimum inhibitory concentration (MIC) against C. perfringens.

Our findings showed that 100 ppm of pistachio peel extract could act as an inhibition factor against the growthof C. perfringens. The RS alone was not able to prevent C. perfringens growth. In contrast, 400 ppm dilution of RS+grapepomace extract could restrain C. perfringens growth. In contrast, the pomegranate pomace extract with and without RScould not inhibit its growth. On the other hand, the RS±pistachio peel extract could not prevent C. perfringens growth, incomparison with other treatments.

We concluded that grape pomace extract, both with and without RS, effectively prevented C.perfringens growth.

Clostridium perfringens causes necrotic enteritis (NE) and is considered a major economic burden in the broiler industry and a significant foodborne pathogen, worldwide.

Clostridium perfringens isolated from NE affected broiler chickens was aimed to characterize and the presence of β-lactamase and quinolone resistant genes were also investigated in the isolates.

A total of 224 intestinal and caecal specimens were collected from NE affected broiler chickens and cultured to isolate C. perfringens. The toxicogenic characterization of C. perfringens was appraised using polymerase chain reaction (PCR) and antibiotic susceptibility testing (disc diffusion method). The selected C. perfringens isolates were characterized for β-lactamase and quinolone encoding genes by PCR analysis.

All isolates were cultured positive for C. perfringens and the toxin-encoding genes of C. perfringens (α-, β-, β2-, ε-, ι-, and enterotoxin) were also identified. About 65.6% of isolates had a multi-drug resistant (MDR) profile but none of these isolates were resistant or susceptible to all screened antibiotics. A subset of isolates, 160 and 98 were analyzed for β-lactamase and quinolone genes, respectively, and recognized blaTEM, blaSHV, and blaOXA in 64 (40%; CI: 32.35-48.03%; P<0.001) isolates, and qnrB and qnrS in 28 (28.57%; CI: 19.90-38.58%; P<0.001) isolates except qnrA.

Therefore, the isolates of C. perfringens were toxicogenic and carried β-lactamase, and quinolone resistance genes. Nowadays, the rational use of antibiotics and safe production of broiler chickens are the major concern to save public health.