Prevalence of Clostridium difficile in raw beef, cow, sheep, goat, camel and buffalo meat in Iran

Prevalence and Antibiotic Resistance of Clostridioides (Clostridium difficile) In Meat and Meat Products: A Systematic Review and Meta-Analysis

Background

Meat and meat products are introduced as one of the frequent sources of Clostridioides difficile. We aimed to determine the prevalence and antibiotic resistance of C. difficile isolates in meat and meat products using a systematic review and meta-analysis.

Methods

A literature search was performed in the primary international and bibliographic databases such as MEDLINE (PubMed), Cochrane Library, Embase, Scopus, and Web of Science to achieve all articles related to the prevalence and antibiotic resistance rates from 2007 to 2022.

Results

The 278 retrieved articles were reduced to 54 worldwide eligible studies after screening and matching inclusion/exclusion criteria. C. difficile was examined in different types of samples and its resistance to 10 antibiotics. The pooled prevalence of C. difficile was 3.4% in all samples. C. difficile pooled prevalence was detected in fish, poultry, and red meat groups with 6.9%, 5.2%, and 3.2%, respectively. Regarding antibiotic resistance, the highest pooled prevalence was for ciprofloxacin (86.6%), followed by clindamycin (42.6%) and erythromycin (34%). The lowest pooled prevalence was observed in metronidazole (7.6%), vancomycin (6.6%), and chloramphenicol (6%).

Conclusion

Low resistance was found to commonly used drugs for C. difficile infection (CDI) treatment. Since each antibiotic can be predisposing cause for CDI development, this finding possibly will be warning from a One Health viewpoint about the misuse of antibiotics in the chain of farm to fork including agriculture, animal husbandry and the food industry and also their injudicious use in medicine.

Characterization of Food Chain Clostridioides difficile Isolates in Terms of Ribotype and Antimicrobial Resistance

The aim of this study was to characterize C. difficile isolates from the farm, abattoir, and retail outlets in Ireland in terms of ribotype and antibiotic resistance (vancomycin, erythromycin, metronidazole, moxifloxacin, clindamycin, and rifampicin) using PCR and E-test methods, respectively. The most common ribotype in all stages of the food chain (including retail foods) was 078 and a variant (RT078/4). Less commonly reported (014/0, 002/1, 049, and 205) and novel (RT530, 547, and 683) ribotypes were also detected, but at lower frequencies. Approximately 72% (26/36 tested) of the isolates tested were resistant to at least one antibiotic, with the majority of these (65%; 17/26) displaying a multi-drug (three to five antibiotics) resistant phenotype. It was concluded that ribotype 078, a hypervirulent strain commonly associated with C. difficile infection (CDI) in Ireland, was the most frequent ribotype along the food chain, resistance to clinically important antibiotics was common in C. difficile food chain isolates, and there was no relationship between ribotype and antibiotic resistance profile.

Global prevalence of Clostridioides difficile in 17,148 food samples from 2009 to 2019: a systematic review and meta-analysis

BACKGROUND

Clostridioides (Clostridium) difficile is an important infectious pathogen, which causes mild-to-severe gastrointestinal infections by creating resistant spores and producing toxins. Spores contaminated foods might be one of the most significant transmission ways of C. difficile-associated infections. This systematic review and meta-analysis study were conducted to investigate the prevalence of C. difficile in food.

METHODS

Articles that published the prevalence of C. difficile in food in PubMed, Web of Science, and Scopus databases were retrieved using selected keywords between January 2009 and December 2019. Finally, 17,148 food samples from 60 studies from 20 countries were evaluated.

RESULTS

The overall prevalence of C. difficile in various foods was 6.3%. The highest and lowest levels of C. difficile contamination were detected to seafood (10.3%) and side dishes (0.8%), respectively. The prevalence of C. difficile was 4% in cooked food, 6.2% in cooked chicken and 10% in cooked seafood.

CONCLUSIONS

There is still little known concerning the food-borne impact of C. difficile, but the reported contamination might pose a public health risk. Therefore, to improve the food safety and prevent contamination with C. difficile spores, it is necessary to observe hygienic issues during foods preparation, cooking and transfer.

Clostridioides difficile in food and food products of animal origin in Assam, India

OBJECTIVE

Considering the paucity of information about food-associated Clostridioides difficile from India, a study was undertaken to establish the prevalence of C. difficile in a variety of foods of animal origin, together with molecular strain characterization and antimicrobial resistance.

METHODS

A total of 235 samples comprising raw meat and meat products, fish products, and milk and milk products were screened for C. difficile. Toxin genes and other parts of PaLoc were amplified in isolated strains. The resistance pattern towards commonly used antimicrobial agents was studied by the Epsilometric test.

RESULTS

C. difficile was isolated from 17(7.23%) different food samples of animal origin, including toxigenic (6) and non-toxigenic (11) isolates. In four toxigenic strains, the tcdA gene could not be detected under used conditions (tcdA-tcdB+). However, all strains had binary toxin-associated genes (cdtA and cdtB). The antimicrobial resistance was highest in non-toxigenic C. difficile isolates in food of animal origin.

CONCLUSION

Meat, meat products and dry fish, but not milk and milk products were contaminated with C. difficile. Contamination rates were low with diverse toxin profiles and antibiotic resistance patterns among the C. difficile strains.

Evaluation of disk diffusion method for testing the rifampicin, erythromycin, and tetracycline susceptibility of Clostridioides (prev. Clostridium) difficile

INTRODUCTION

Antimicrobial resistance (AMR) is one of the greatest threats to animal and public health. Clostridioides (prev. Clostridium) difficile is a major burden to healthcare and a relevant AMR gene reservoir. Despite the known importance of AMR in C. difficile epidemiology and treatment, antimicrobial susceptibility testing for this pathogen is still based on the determination of the minimal inhibitory concentration (MIC) by the agar dilution method, which is technically demanding and labor-intensive. In this study, the disk diffusion method was used to evaluate the susceptibility of C. difficile to erythromycin, rifampicin, and tetracycline.

MATERIAL AND METHODS

A total of 155 isolates isolated between 2011 and 2022 from humans and animals in Brazil were simultaneously tested using the disk diffusion method and the epsilometer test (Etest) for these three antimicrobials on Brucella blood agar supplemented with vitamin K and hemin.

RESULTS

The results suggest that disk diffusion can be an interesting routine tool to identify erythromycin- and rifampicin-resistant C. difficile isolates (≥20 mm cut-off) and wild type (WT) strains (≥28 mm). However, the disk diffusion protocol tested in this study does not seem suitable for tetracycline because of the common misclassification of resistant strains.

Clostridioides difficile in South American Camelids in Germany: First Insights into Molecular and Genetic Characteristics and Antimicrobial Resistance

Little is known about zoonotic pathogens and their antimicrobial resistance in South American camelids (SAC) in Germany including Clostridioides (C.) difficile. The aim of this study was to investigate prevalence, molecular characteristics and antimicrobial resistance of C. difficile in SAC. Composite SAC faecal samples were collected in 43 husbandries in Central Germany and cultured for C. difficile. Toxinotyping and ribotyping was done by PCR. Whole genome sequencing was performed with Illumina^® Miseq™. The genomes were screened for antimicrobial resistance determinants. Genetic relatedness of the isolates was investigated using core genome multi locus sequence typing (cgMLST) and single nucleotide polymorphism analysis. Antimicrobial susceptibility testing was done using the Etest^® method. Eight C. difficile isolates were recovered from seven farms. The isolates belonged to different PCR ribotypes. All isolates were toxinogenic. cgMLST revealed a cluster containing isolates recovered from different farms. Seven isolates showed similar resistance gene patterns. Different phenotypic resistance patterns were found. Agreement between phenotypic and genotypic resistance was identified only in some cases. Consequently, SAC may act as a reservoir for C. difficile. Thus, SAC may pose a risk regarding zoonotic transmission of toxinogenic, potentially human-pathogenic and resistant C. difficile isolates.

Examining the Extent of Contamination, Antibiotic Resistance, and Genetic Diversity of Clostridioides (Clostridium) difficile Strains in Meat and Feces of Some Native Birds of Iran

Clostridioides (Clostridium) difficile (C. difficile) is one of the essential enteropathogens in humans and livestock and is a severe health threat, according to the Centre for Disease Control and Prevention. Also, antimicrobials are one of the most critical risk factors for C. difficile infection (CDI). The present study examined the infection, antibiotic resistance, and genetic diversity of the C. difficile strains in the meat and feces of some native birds (chicken, duck, quail, and partridge) in the Shahrekord region, Iran, from July 2018 to July 2019. Samples were grown on CDMN agar after an enrichment step. To determine the toxin profile, the tcdA, tcdB, tcdC, cdtA, and cdtB genes were detected via multiplex PCR. The antibiotic susceptibility of these isolates was examined using the disk diffusion method and followed based on MIC and epsilometric test. 300 meat samples of chicken, duck, partridge, and quail and 1100 samples of bird feces were collected from six traditional farms in Shahrekord, Iran. Thirty-five meat samples (11.6%) and 191 fecal samples (17.36%) contained C. difficile. Moreover, five toxigenic samples isolated had 5, 1, and 3 tcdA/B, tcdC, and cdtA/B genes. Out of the studied strains isolated from the 226 samples, two isolates belonging to ribotype RT027 and one isolated RT078 profile related to native chicken feces were observed from chicken sample. The antimicrobial susceptibility testing showed that all the strains are resistant to ampicillin, 28.57% are resistant to metronidazole, and 100% were susceptible to vancomycin. Based on the results, it can be concluded that the raw meat of birds might be a source of resistant C. difficile that poses a hygienic threat to the consumption of native bird meat. Nevertheless, further studies are essential to understand additional epidemiological features of C. difficile in bird meat.

Clostridioides difficile in Foods with Animal Origins; Prevalence, Toxigenic Genes, Ribotyping Profile, and Antimicrobial Resistance

Clostridioides difficile is an important nosocomial pathogen and is considered as a reason of diarrhea and gastrointestinal infections. As a majority of community-originated C. difficile cases are not related to antibiotic prescription and hospitalization, the food portion as a vector of infection transmission has been raised. An existing survey was aimed evaluating the prevalence, antimicrobial resistance, profile of toxigenic genes, and ribotypes of C. difficile isolated from raw meat and carcass surface swab samples. In total, 485 raw meat and carcass surface swab samples were collected. C. difficile was isolated via culture and a diverse biochemical examination. The assessment of minimum inhibitory concentration (MIC) was addressed to evaluate the antibiotic resistance of isolates. Toxin genes detection and ribotyping were used for isolates characterization. The prevalence of C. difficile contamination in all examined samples was 3.71%. The bacterium was detected in 2.91% of raw meat and 4.48% of carcass surface swab samples. Raw sheep meat (5%) and sheep carcass swab (7.50%) samples harbored the highest C. difficile prevalence. The highest rate of antibiotic resistance was observed toward clindamycin (38.88%), ciprofloxacin (38.88%), metronidazole (44.44%), erythromycin (72.22%), and tetracycline (77.77%). C. difficile bacteria showed the minimum rate of resistance meropenem (16.66%) and chloramphenicol (16.66%). TcdA, tcdB, cdtA, and cdtB toxigenic genes were detected in 22.22%, 44.44%, and 16.66% of isolates, respectively. TcdB + tcdA (27.77%) were the most prevalent combined toxigenic gene profile. Both 027 and 078 ribotypes were identified in C. difficile isolates. The role of raw meat and carcass surface swab samples as toxigenic and antibiotic-resistant C. difficile strains vectors was signified. This study authorizes that food animals, particularly sheep and cattle, are C. difficile carriers at slaughter stages and ribotypes are equal in human cases. Subsequently, contamination of carcasses occurs inside the slaughterhouse.

Clostridioides difficile epidemiology in the Middle and the Far East

OBJECTIVES

Clostridioides difficile is an important pathogen of healthcare-associated gastrointestinal infections. Recently, an increased number of C. difficile infection (CDI) surveillance data has been reported from Asia. The aim of this review is to summarize the data on the prevalence, distribution and molecular epidemiology of CDI in the Middle and the Far East.

METHODS

Literature was drawn from a search of PubMed up to September 30, 2021.

RESULTS

The meta-analysis of data from 111 studies revealed the pooled CDI prevalence rate in the Middle and the Far East of 12.4% (95% CI 11.4-13.3); 48 studies used PCR for CDI laboratory diagnoses. The predominant types (RT)/sequence type (ST) differ between individual countries (24 studies, 14 countries). Frequently found RTs were 001, 002, 012, 017, 018 and 126; RT017 was predominant in the Far East. The epidemic RT027 was detected in 8 countries (22 studies), but its predominance was reported only in three studies (Israel and Iran). The contamination of vegetable and meat or meat products and/or intestinal carriage of C. difficile in food and companion animals have been reported; the C. difficile RTs/STs identified overlapped with those identified in humans.

CONCLUSIONS

A large number of studies on CDI prevalence in humans from the Middle and the Far East have been published; countries with no available data were identified. The number of studies on C. difficile from non-human sources is limited. Comparative genomic studies of isolates from different sources are needed.

Clostridioides difficile infection: an emerging zoonosis?

INTRODUCTION

Clostridioides difficile (C. difficile) infection (CDI) is the most common cause of antibiotic-associated diarrhea and one of the common infections in healthcare facilities. In recent decades, there has been an emerging threat of community-acquired CDI (CA-CDI). Environmental transmission of C. difficile in the community setting has become a major concern, and animals are an important reservoir for C. difficile causing human diseases.

AREAS COVERED

In this article, the molecular epidemiology of C. difficile in animals and recent evidences of zoonotic transfer to humans are reviewed based on an electronic search in the databases of PubMed and Google Scholar.

EXPERT OPINION

C. difficile can be found in stool from diarrheal dogs and cats; therefore, household pets could be a potential source. C. difficile will threaten human health because hypervirulent C. difficile ribotype 078 strains have been found in retail chickens, pig farms, and slaughterhouses. Risk factors for fecal C. difficile carriage in animals include young age, dietary changes, and antibiotic abuse in domestic animals. With the advent of whole genome sequencing techniques, there will be more solid evidence indicating zoonotic transfer of C. difficile from animals to humans.

Clostridioides difficile in Non-hospital Sources (Animals, Food, and Environment) in Asian Countries: A Literature Review

Context: Clostridioides difficile (C. difficile) is an agent responsible for severe infection with a high mortality rate in healthcare facilities. With the discovery of C. difficile in the community, it was assumed that this bacterium might be transmitted to humans through non-hospital sources. Evidence Acquisition: This study examined different aspects of the epidemiology of C. difficile in Asian countries with a review of the literature using search engines such as Web of Science, Scopus, and PubMed. Results: Based on the literature pertaining to Asia, the highest rate of C. difficile is found in samples collected from farm animals, red meat, and meat-based products. Two ribotypes 027 and 078, as hypervirulent factors, were found in different non-hospital sources. Resistance to the most frequently used antibiotics in healthcare setting was observed in C. difficile. Conclusions: Due to the heterogeneity of the examination of C. difficile, understanding the actual condition of C. difficile is difficult. However, the presence of two hypervirulent ribotypes of C. difficile in non-hospital sources is alarming. It seems that it is necessary to perform further studies on C. difficile in non-hospital sources. Defining a focal point for such research could be helpful to explore the situation of C. difficile in clinical settings and communities of Asian countries.

Effects of tissue-specific biomolecules on piglets after-weaning period

Background and Aim

Now-a-days antibiotics are the main tool for correcting the pathological conditions of pigs; unfortunately, antibiotics are a potential threat to the environment, as they lead to the spread of antibiotic-resistant infections. This study aimed to study the immunomodulatory encapsulated biomolecules on piglets in the post-weaning period.

Materials and Methods

An immunomodulator based on biomolecules obtained from animal raw materials included in alginate capsules to improve absorption has been developed. The study presents the results of a study on 25 weaned piglets (25-30 days old) which received biomolecules at a dose of 200 mg/piglet for 14 days, followed by 400 mg/piglet from days 15 to 28. Blood was taken from animals for analysis (biochemical, hematological, cytometric, and enzyme immunoassay) and the integral index of blood serum antimicrobial activity was determined.

Results

Experimental animals, whose initial weight was 1.6 times less than that of the control animals, were able to bridge this gap and, on the 28^th day, there were no differences in weight. Stimulation of the production of cytokines interleukin (IL)-2 and IL-4 was observed and the antimicrobial resistance of blood serum to Escherichia coli also increased. A positive effect on the metabolism of piglets was noted, which helped them adapt to a change in diet (from colostrum to solid food).

Conclusion

The results show that the immunomodulation at the dose of 150 mg/kg body weight has a great potential for improving weaned pigs.

One Health approach to Clostridioides difficile in Japan

Clostridioides difficile infections (CDIs) are predominantly a healthcare-associated illness in developed countries, with the majority of cases being elderly and hospitalize patients who used antibiotic therapy. Recently, the incidence of community-associated CDIs (CA-CDIs) in younger patients without a previous history of hospitalization or antibiotic treatment has been increasing globally. C. difficile is sometimes found in the intestine of many animals, such as pigs, calves, and dogs. Food products such as retail meat products and vegetables sometimes contain C. difficile. C. difficile has also been isolated from several environments such as compost manure, rivers, and soils. Yet, direct transmission of C. difficile from animals, food products, and environments to humans has not been proven, although these strains have similar molecular characteristics. Therefore, it has been suggested that there is a relationship between CA-CDIs and C. difficile from animals, food products, and the environment. To clarify the importance of the presence of C. difficile in several sources, characterization of C. difficile in these sources is required. However, the epidemiology of C. difficile in animals, food products, and the environment is not well studied in Japan. This review summarizes recent trends of CDIs and compares the molecular characteristics of C. difficile in Japanese animals, food products, and the environment. The prevalence trends of C. difficile in Japan are similar to those in the rest of the world. Therefore, I recommend using a One Health approach to CDI surveillance, monitoring, and control.

Global and Historical Distribution of Clostridioides difficile in the Human Diet (1981-2019): Systematic Review and Meta-Analysis of 21886 Samples Reveal Sources of Heterogeneity, High-Risk Foods, and Unexpected Higher Prevalence Toward the Tropic

Clostridioides difficile (CD) is a spore-forming bacterium that causes life-threatening intestinal infections in humans. Although formerly regarded as exclusively nosocomial, there is increasing genomic evidence that person-to-person transmission accounts for only <25% of cases, supporting the culture-based hypothesis that foods may be routine sources of CD-spore ingestion in humans. To synthesize the evidence on the risk of CD exposure via foods, we conducted a systematic review and meta-analysis of studies reporting the culture prevalence of CD in foods between January 1981 and November 2019. Meta-analyses, risk-ratio estimates, and meta-regression were used to estimate weighed-prevalence across studies and food types to identify laboratory and geographical sources of heterogeneity. In total, 21886 food samples were tested for CD between 1981 and 2019 (96.4%, n = 21084, 2007–2019; 232 food-sample-sets; 79 studies; 25 countries). Culture methodology, sample size and type, region, and latitude were sources of heterogeneity (p < 0.05). Although non-strictly-anaerobic methods were reported in some studies, and we confirmed experimentally that improper anaerobiosis of media/sample-handling affects CD recovery in agar (Fisher, p < 0.01), most studies (>72%) employed the same (one-of-six) culture strategy. Because the prevalence was also meta-analytically similar across six culture strategies reported, all studies were integrated using three meta-analytical methods. At the study level (n = 79), the four-decade global cumulative-prevalence of CD in the human diet was 4.1% (95%CI = −3.71, 11.91). At the food-set level (n = 232, mean 12.9 g/sample, similar across regions p > 0.2; 95%CI = 9.7–16.2), the weighted prevalence ranged between 4.5% (95%CI = 3–6%; all studies) and 8% (95%CI = 7–8%; only CD-positive-studies). Risk-ratio ranking and meta-regression showed that milk was the least likely source of CD, while seafood, leafy green vegetables, pork, and poultry carried higher risks (p < 0.05). Across regions, the risk of CD in foods for foodborne exposure reproducibly decreased with Earth latitude (p < 0.001). In conclusion, CD in the human diet is a global non-random-source of foodborne exposure that occurs independently of laboratory culture methods, across regions, and at a variable level depending on food type and latitude. The latitudinal trend (high CD-food-prevalence toward tropic) is unexpectedly inverse to the epidemiological observations of CD-infections in humans (frequent in temperate regions). Findings suggest the plausible hypothesis that ecologically-richer microbiomes in the tropic might protect against intestinal CD colonization/infections despite CD ingestion.

The emergence of metronidazole and vancomycin reduced susceptibility in Clostridium difficile isolates in Iran

OBJECTIVES

Clostridium difficile (C. difficile) is the main causative agent of antibiotic-associated diarrhoea (AAD) and pseudomembranous colitis. The accumulation of antimicrobial resistance in C. difficile strains can drive C. difficile infection (CDI) epidemiology. This study was undertaken to evaluate the antimicrobial resistance patterns of toxigenic C. difficile isolates cultured from diarrhoeal stool samples of hospitalised patients with suspected CDI in three tertiary care hospitals in Tehran, Iran.

METHODS

Two hundred and fifty diarrhoeal stool samples were investigated by toxigenic culture using cycloserine-cefoxitin-fructose agar and the VERO cell line. Antimicrobial susceptibility to metronidazole, vancomycin, clindamycin, tetracycline, and moxifloxacin was performed by disk diffusion and Etest methods on Brucella Blood Agar supplemented with hemin and vitamin K.

RESULTS

Thirty-five stool samples (14.0%) proved positive using C. difficile toxigenic culture. According to Clinical and Laboratory Standards Institute breakpoints, the following resistance was identified in C. difficile isolates: metronidazole (2 of 35); moxifloxacin (7 of 35); clindamycin (18 of 35); and tetracycline (5 of 35). Using European Committee on Antimicrobial Susceptibility Testing breakpoints, three of 35 isolates showed reduced-susceptibility for vancomycin and 14 of 35 for metronidazole. In addition, the results showed a good correlation between the inhibition zone diameter (disk diffusion) and MIC values (Etest); Pearson correlation coefficient 0.7400.95 (P< 0.001).

CONCLUSIONS

Multidrug resistance was observed in Iranian clinical toxigenic C. difficile isolates, including reduced susceptibility to first-line CDI treatment drugs. In addition, disk diffusion can be used as a cost-effective option for the antimicrobial susceptibility testing of C. difficile isolates.

Genomic Delineation of Zoonotic Origins of Clostridium difficile

Clostridium difficile is toxin-producing antimicrobial resistant (AMR) enteropathogen historically associated with diarrhea and pseudomembranous colitis in hospitalized patients. In recent years, there have been dramatic increases in the incidence and severity of C. difficile infection (CDI), and associated morbidity and mortality, in both healthcare and community settings. C. difficile is an ancient and diverse species that displays a sympatric lifestyle, establishing itself in a range of ecological niches external to the healthcare system. These sources/reservoirs include food, water, soil, and over a dozen animal species, in particular, livestock such as pigs and cattle. In a manner analogous to human infection, excessive antimicrobial exposure, particularly to cephalosporins, is driving the expansion of C. difficile in livestock populations worldwide. Subsequent spore contamination of meat, vegetables grown in soil containing animal feces, agricultural by-products such as compost and manure, and the environment in general (households, lawns, and public spaces) is contributing to a persistent community source/reservoir of C. difficile and the insidious rise of CDI in the community. The whole-genome sequencing era continues to redefine our view of this complex pathogen. The application of high-resolution microbial genomics in a One Health framework (encompassing clinical, veterinary, and environment derived datasets) is the optimal paradigm for advancing our understanding of CDI in humans and animals. This approach has begun to yield critical insights into the genetic diversity, evolution, AMR, and zoonotic potential of C. difficile. In Europe, North America, and Australia, microevolutionary analysis of the C. difficile core genome shows strains common to humans and animals (livestock or companion animals) do not form distinct populations but share a recent evolutionary history. Moreover, for C. difficile sequence type 11 and PCR ribotypes 078 and 014, major lineages of One Health importance, this approach has substantiated inter-species clonal transmission between animals and humans. These findings indicate either a zoonosis or anthroponosis. Moreover, they challenge the existing paradigm and the long-held misconception that CDI is primarily a healthcare-associated infection. In this article, evolutionary, and zoonotic aspects of CDI are discussed, including the anthropomorphic factors that contribute to the spread of C. difficile from the farm to the community.

Clostridium difficile isolated from faecal samples in patients with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is an inflammatory bowel disease (IBD) that is widely identified worldwide. This study aimed to investigate the phenotypic characterization and molecular typing of Clostridium difficile isolates among patients with UC at an inflammatory bowel disease clinic in Iran.

METHODS

In this cross-sectional study, conducted from April 2015 to December 2015, 85 UC patients were assessed for C.difficile infection (CDI). C. difficile isolates were characterized based on their toxin profile and antimicrobial resistance pattern. Multi-locus sequence typing analysis (MLST) and PCR ribotyping were performed to define the genetic relationships between different lineages of toxigenic strains.

RESULTS

The prevalence of C. difficile isolates was 31.8% (27/85) in patients, of those 15 patients (17.6%) had CDI. Three different sequence types (STs) identified based on MLST among the toxigenic isolates, that is ST54 (33.3%), ST2 (53.3%), and ST37 (13.6%). C. difficile strains were divided into four different PCR-ribotypes (012, 014, 017 and IR1). The most common ribotype was 014 accounting for 48.3% (7/15) of all strains. The strains isolated during the first episode and recurrence of CDI usually belonged to PCR ribotype 014 (ST2). A high rate of CDI recurrence (14.1%, 12/85) experienced in UC patients. Colonization of the gastrointestinal tract with non-toxigenic C. difficile strains was frequent among patients with mild disease. All C. difficile isolates were susceptible to metronidazole, and vancomycin, 86 and 67% of isolates were resistant to clindamycin and erythromycin respectively. There was no correlation between the toxin type and antibiotic resistance (p > 0.05).

CONCLUSION

Overall CDI is rather prevalent in UC patients. All patients with CDI experienced moderate to severe disease and exposed to different antimicrobial and anti-inflammatory agents. Close monitoring and appropriate management including early detection and fast treatment of CDI will improve UC outcomes.

The prevalence of antibiotic-resistant Clostridium species in Iran: a meta-analysis

Clostridium species are ubiquitous and associated with various diseases in animals and humans. However, there is little knowledge about the prevalence of their resistance to antibiotics in Iran. Therefore, the aim of this study was to determine the prevalence of antibiotic-resistant Clostridium species in Iran through a meta-analysis of eligible studies published up until December 2018. Fourteen articles on the drug resistance of Clostridium species in Iran were included in the current study following a search in PubMed, Scopus and Google Scholar databases using relevant keywords and screening based on inclusion and exclusion criteria. Antibiotic resistance rates of C. difficile to ampicillin (42.8%), ciprofloxacin (69.5%), clindamycin (84.3%), erythromycin (61.5%), gentamicin (93.5%), nalidixic acid (92.9%), tetracycline (32.5%), imipenem (39.6%), levofloxacin (93.4%), ertapenem (58.7%), piperacillin/tazobactam (56.5%), kanamycin (100%), colistin (100%), ceftazidime (76%), amikacin (76.5%), moxifloxacin (67.9%) and cefotaxime (95%) were high. In addition, resistance of C. perfringens to ampicillin (25.8%), erythromycin (32.9%), gentamicin (45.4%), nalidixic acid (52.5%), tetracycline (19.5%), penicillin (21.8%), trimethoprim-sulfamethoxazole (32.1%), amoxicillin (19.3%), imipenem (38%), cloxacillin (100%), oxacillin (45.6%), bacitracin (89.1%) and colistin (40%) was high. Metronidazole and vancomycin, as the first-line therapies, fidaxomicin, tetracyclines (except tetracycline), rifampicin and chloramphenicol can still be used for the treatment of C. difficile infections. However, the present results do not recommend the use of penicillin, bacitracin and tetracycline for the treatment of C. perfringens infections in humans and domestic animals in Iran.

Clostridioides difficile in the environment, food, animals and humans in southern Italy: Occurrence and genetic relatedness

One hundred and thirty-eight C. difficile isolates from different sources (66 from the environment, 36 from animals, 9 from food and 27 from humans) were ribotyped by capillary electrophoresis PCR ribotyping (CE-PCR). A multilocus variable tandem repeat analysis (MLVA) was carried out on a sample subset. The most frequently isolated PCR ribotypes were 126 (15.9%), 078 (14.5%), 011/018 (11.6%), 014/020/077 (10.1%), and 010 (2.8%). In particular, strains of PCR ribotype 011/018 were isolated from human, raw milk and environmental samples. The hypervirulent PCR ribotype 027 was isolated from two human samples. The majority of the strains were toxigenic (34.1% showed the toxigenic profile A⁺B⁺CDT⁺ and 38.9% the profile A⁺B⁺CDT^-). MLVA allowed to identify 4 clonal complexes of genetically related isolates: complex n. 1 grouped together human, environmental and food strains, whereas complex n. 3 included human and environmental isolates. The use of MLVA gave further evidence to the possible role of environment, animals and food as routes of transmission of C. difficile infections to human.

Prevalence of Clostridium difficile and its toxigenic genotype in beef samples in west of Iran

BACKGROUND AND OBJECTIVES

Clostridium difficile is the leading cause of nosocomial diarrhea and pseudomembranous colitis. The prevalence of C. difficile infection differs in various geographical areas. The aim of this study was to determine the prevalence of C. difficile isolates and the prevalence of cdd3, tcdA and tcdB genes in beef samples in Kermanshah Province.

MATERIALS AND METHODS

One hundred ground beef samples were randomly collected from the butchers of Kermanshah province during March 2014 to March 2015. Following alcohol shock, minced meat samples were incubated in a specific culture medium for 5 to 7 days. The suspicious colonies were analyzed by biochemical tests and frequency of C. difficile and cdd3, tcdA and tcdB genes was assessed by PCR using specific primers.

RESULTS

In total, 30% samples were positive for C. difficile and all the isolates harbored Cdd3 gene. Combined dual-gene frequency of A⁺B⁺, A^-B⁺ and A⁺B^- strains in the positive were 0%, 3.3%, and 26.6% respectively, while 21 samples (70%) were non-toxigenic (A^-B^-).

CONCLUSION

In this study, the presence of C. difficile in beef as a source of contamination was confirmed. It was also shown that the incidence of C. difficile in ground meat was relatively higher than many other studies.

Clostridium difficile Infection in Production Animals and Avian Species: A Review

Clostridium difficile is the leading cause of antibiotic-associated diarrhea and colitis in hospitalized humans. Recently, C. difficile infection (CDI) has been increasingly recognized as a cause of neonatal enteritis in food animals such as pigs, resulting in stunted growth, delays in weaning, and mortality, as well as colitis in large birds such as ostriches. C. difficile is a strictly anaerobic spore-forming bacterium, which produces two toxins A (TcdA) and B (TcdB) as its main virulence factors. The majority of strains isolated from animals produce an additional binary toxin (C. difficile transferase) that is associated with increased virulence. C. difficile is ubiquitous in the environment and has a wide host range. This review summarizes the epidemiology, clinical presentations, risk factors, and laboratory diagnosis of CDI in animals. Increased awareness by veterinarians and animal owners of the significance of clinical disease caused by C. difficile in livestock and avians is needed. Finally, this review provides an overview on methods for controlling environmental contamination and potential therapeutics available.

Isolation and characterization of Clostridium difficile in farm animals from slaughterhouse to retail stage in Isfahan, Iran

To determine the prevalence of Clostridium difficile in farm animals from slaughterhouse through to retail stage, a total of 750 samples of feces, posteviscerated and washed carcass were collected from cattle, camels, goats, and sheep in Isfahan, Iran. The overall prevalence of C. difficile in feces, posteviscerated and washed carcass were 20 (13.3%), 23 (15.3%), and 11 (7.3%), respectively; while C. difficile was isolated from 79 (26.3%) retail samples. Twenty-nine (3.8%) isolates were toxigenic, with most toxigenic isolates (n = 17, 5.6%) identified from the retail stage. All toxigenic isolates harbored tcdA and tcdB; however, all were negative for cdtB. The 29 isolates were classified into 21 different ribotypes. This study revealed evidence of existence of toxigenic C. difficile in farm animal feces and meat in Iran.

Clostridium difficile in Food and Animals: A Comprehensive Review

Zoonoses are infections or diseases that can be transmitted between animals and humans through direct contact, close proximity or the environment. Clostridium difficile is ubiquitous in the environment, and the bacterium is able to colonise the intestinal tract of both animals and humans. Since domestic and food animals frequently test positive for toxigenic C. difficile, even without showing any signs of disease, it seems plausible that C. difficile could be zoonotic. Therefore, animals could play an essential role as carriers of the bacterium. In addition, the presence of the spores in different meats, fish, fruits and vegetables suggests a risk of foodborne transmission. This review summarises the current available data on C. difficile in animals and foods, from when the bacterium was first described up to the present.

Isolation of Clostridium difficile and molecular detection of binary and A/B toxins in faeces of dogs

The aim of this study was to isolate Clostridium difficile from dogs' faeces, and to study the frequency of its virulence genes. A total of 151 samples of dogs' faeces were collected. The isolation of C. difficile was performed by using the bacterial culture methods followed by DNA extraction using boiling method. Multiplex PCR method was performed for identification of tcdA, tcdB, cdtA and cdtB genes and single method was carried out for detection of tcdC. Twelve samples (7.9%) were positive in bacteriological assay and based on molecular assay, 66.7% of the isolates (8 of 12 C. difficile isolated) had shown tcdA⁺, tcdB⁺ profile. This is the first investigation on molecular assay of C. difficile in Iran's dog population.

Isolation of toxigenic Clostridium difficile from ready-to-eat salads by multiplex polymerase chain reaction in Isfahan, Iran

Background:

Since 2003, the incidence of community associated Clostridium difficile infection (CA-CDI) has increased; different types of food have been supposed to be the vectors of C. difficile strains. The purpose of this study is to investigate the occurrence of C. difficile strains in ready-to-eat salads distributed in food services.

Materials and Methods:

A total of 106 ready-made salad specimens were sampled from different restaurants and food services located in Isfahan, in the center of Iran. Positive isolates of C. difficile were identified and confirmed for the existence of three genes including tpi, tcdA and tcdB by multiplex PCR.

Results:

A total of six (5.66%) samples were positive for C. difficile strains. Of which, one strain (16.6%) was positive for A and B toxins.

Conclusion:

The existence of toxigenic C. difficile in ready-made salads could be a caution for public health. Further investigation is required to assess the relationship between the isolated strains in our study and those from diarrheic patients through molecular typing.

Toxigenic Clostridium difficile PCR ribotypes in edible marine bivalve molluscs in Italy

Even though food of animal sources and different foodstuffs are well known to be potentially carrier of Clostridium difficile, few data are available on the occurrence of C. difficile in seafood. This work investigated the occurrence of C. difficile in edible bivalve molluscs in southern Italy. Out of the 925 investigated samples, 3.9% contained C. difficile. Eighteen strains harboured both genes for toxins A and B whereas 1 only had toxin B gene. Binary toxin genes were found in 22.2% of the isolates. The most frequently ribotypes found were 078/126 (22.2%), 010 (19.4%), and 001 (8.3%). All isolates were susceptible to metronidazole, vancomycin, fidaxomicin, and to the new semisynthetic thiopeptide antibiotic LFF571, whereas 19.4% of them were resistant to moxifloxacin, 30.5% to clindamycin, 38.8% to erythromycin, and 100% to ciprofloxacin. This study points out that edible molluscs could be a potential source of toxigenic C. difficile ribotypes and a potential risk for human health.

High-throughput assessment of bacterial ecology in hog, cow and ovine casings used in sausages production

Natural casings derived from different intestine portions have been used for centuries in the production of fresh and dry-fermented sausages. Here we analysed by means of culture-dependent methods and Illumina high-throughput sequencing of 16S rRNA amplicons the bacterial ecology of hog, cow and ovine casings at different stages of their preparation for sausages production. Several strains of Staphylococcus, Lactobacillus, Bifidobacterium, Vagococcus and Clostridium were counted, isolated and characterised at phylogenetic level. High-throughput sequencing analyses revealed a high bacterial diversity, which differed strongly between casings of different animal species. The technological processes involved in the preparation for casing had also a strong impact on the casings bacterial ecology, with a significant reduction of undesired microorganisms, and an increase in the proportion of lactobacilli and staphylococci. Natural casings were demonstrated to be complex ecological environments, whose role as microbiological inoculants in the production of sausages should not be underestimated.

Occurrence of Clostridium difficile in seasoned hamburgers and seven processing plants in Iran

BACKGROUND

The recent increment of the incidence of Community Associated Clostridium difficile Infection (CA)-CDI has led to speculation that this disease is associated to foodborne transmission. Therefore it is critical to establish the community sources of CDI in order to implement the appropriate interventions. The present study was conducted to evaluate the prevalence of C. difficile in seasoned hamburger and examine the sources of C. difficile dispersal in hamburger processing plants. A total of 211 samples including hamburger ingredients, the final product, processing equipment and food contact surfaces were collected from seven hamburger processing plants to evaluate the routes of dispersal of C. difficile. The samples were assessed for the occurrence of C. difficile using culture and polymerase chain reaction (PCR) methods. All isolates were screened for the existence of toxin A, B and binary toxin genes. In addition, isolates were subjected to PCR ribotyping.

RESULTS

Overall, 9/211 (4.2%) samples were positive. Toxigenic C. difficile were detected from 2/7 (28.5%) hamburger processing plants, in (3/54) 5.6% of beef meat samples, (2/56) 3.5% of swabs taken from the environment and (4/56) 7.1% of hamburger samples after both molding and freezing. C. difficile was not found in 45 non-meat ingredients including 14 defrosted onions, 14 textured soy proteins and 17 seasonings. All isolates contained tcdB gene while 7 strains were positive for tcdA and two remaining strains were negative for tcdA. None of the isolates harbored binary toxin gene (cdtB). PCR ribotyping of 9 isolates categorized into four ribotypes (IR21, IR 22, IR 23 and IR24). Ribotype IR 22 was the most common type 6/9 (66.6%) found. This genotype was isolated from raw meat, environmental samples and hamburger after both forming and freezing in one processing plant, suggesting raw beef meat as a possible major source of contamination.

CONCLUSIONS

Hyper-virulent strains of ribotype were not found in this study however, occurrence of other toxicgenic strains indicate the public health significance of contamination of this product.

Prevalence and Characterization of Clostridium difficile in Beef and Mutton Meats of Isfahan Region, Iran

Background:

Clostridium difficile (C. difficile) is a frequent cause of nosocomial infections. During last few years, the mortality rate of C. difficile infection (CDI) increased in healthcare facilities. This organism has become a major public health concern in developed nations. Because of the increasing incidence of acquired-CDI (CA-CDI) and notable genetic overlap between C. difficile isolates from animals and humans, meat has defined as one of the probable transmission route of C. diffiicle to humans.

Objectives:

This study was performed to determine the prevalence of toxigenic C. difficile in beef and mutton meats consumed as human food in Isfahan, central part of Iran. Furthermore the polymerase chain reaction (PCR)-ribotyping employed to compare the genetic pattern of positive isolates in meat with clinical ones.

Materials and Methods:

A total of 200 raw meat samples (81 beef and 119 mutton) were purchased from meat packaging plants. The samples were anaerobically cultured in C. difficile moxalactam norfloxacin (CDMN) broth and plated on selective enrichment medium. The suspicious colonies were recultured on blood agar anaerobically. All C. difficile isolates identified by morphological and biochemical testing were screened by PCR for the presence of genes encoding the triose phosphate isomerase (tpi), toxin A (tcdA), toxin B (tcdB) and binary toxin (cdtB). The genomes of extracted isolates were analyzed by 16S-23S rRNA-based PCR ribotyping.

Results:

The overall prevalence of C. difficile with two toxigenic genes including tcdA and tcdB was estimated at 4.0%. C. difficile was detected in 2.8%, 2.1%, 3.6% and 6.2% of chopped beef, ground beef, chopped mutton and ground mutton, respectively. The cdtB gene was not found in positive isolates. Eight different ribotypes were found in isolated strains that were not identical with those belonging to patients with CDI.

Conclusions:

The results of PCR-ribotyping indicate that no relationship exists between clinical and meat isolates. We therefore conclude that other sources than meat may function as a vector for CA-CDI.