Multilocus sequence typing analysis and antibiotic resistance of Clostridium difficile strains isolated from retail meat and humans in Belgium

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.

Spore-Forming Clostridium (Clostridioides) difficile in Wastewater Treatment Plants in Western Australia

There is growing evidence that shows Clostridium (Clostridioides) difficile is a pathogen of One Health importance with a complex dissemination pathway involving animals, humans, and the environment. Thus, environmental discharge and agricultural recycling of human and animal waste have been suspected as factors behind the dissemination of Clostridium difficile in the community. Here, the presence of C. difficile in 12 wastewater treatment plants (WWTPs) in Western Australia was investigated. Overall, C. difficile was found in 90.5% (114/126) of raw sewage influent, 48.1% (50/104) of treated effluent, 40% (2/5) of reclaimed irrigation water, 100% (38/38) of untreated biosolids, 95.2% (20/21) of anaerobically digested biosolids, and 72.7% (8/11) of lime-amended biosolids. Over half of the isolates (55.3% [157/284]) were toxigenic, and 97 C. difficile ribotypes (RTs) were identified, with RT014/020 the most common (14.8% [42/284]). Thirteen C. difficile isolates with the toxin gene profile A⁺ B⁺ CDT⁺ (positive for genes coding for toxins A and B and the binary C. difficile transferase toxin [CDT]) were found, including the hypervirulent RT078 strain. Resistance to the antimicrobials fidaxomicin, vancomycin, metronidazole, rifaximin, amoxicillin-clavulanate, meropenem, and moxifloxacin was uncommon; however, resistance to clindamycin, erythromycin, and tetracycline was relatively frequent at 56.7% (161/284), 14.4% (41/284), and 13.7% (39/284), respectively. This study revealed that toxigenic C. difficile was commonly encountered in WWTPs and being released into the environment. This raises concern about the possible spillover of C. difficile into animal and/or human populations via land receiving the treated waste. In Western Australia, stringent measures are in place to mitigate the health and environmental risk of recycling human waste; however, further studies are needed to elucidate the public health significance of C. difficile surviving the treatment processes at WWTPs. IMPORTANCE Clostridium difficile infection (CDI) is a leading cause of antimicrobial-associated diarrhea in health care facilities. Extended hospital stays and recurrences increase the cost of treatment and morbidity and mortality. Community-associated CDI (CA-CDI) cases, with no history of antimicrobial use or exposure to health care settings, are increasing. The isolation of clinically important C. difficile strains from animals, rivers, soil, meat, vegetables, compost, treated wastewater, and biosolids has been reported. The objective of this study was to characterize C. difficile in wastewater treatment plants (WWTPs) in Australia. We found that C. difficile can survive the treatment processes of WWTPs, and toxigenic C. difficile was being released into the environment, becoming a potential source/reservoir for CA-CDI.

Prevalence, Molecular Characterization and Antimicrobial Susceptibility of Clostridioides difficile Isolated from Pig Carcasses and Pork Products in Central Italy

In the last decade, the incidence and severity of Clostridioides difficile infections (CDIs) in humans have been increasing and community-associated infections have been described. For these reasons, the interest in C. difficile in food and in food animals has increased, suggesting other possible sources of C. difficile acquisition. This study evaluated the presence of C. difficile on pig carcasses at the slaughterhouse and in pork products in Central Italy. The contamination rate on pig carcasses was 4/179 (2.3%). Regarding food samples, a total of 216 pork products were tested (74 raw meat preparations and 142 ready-to-eat food samples made by cured raw meat). The real-time PCR screening was positive for 1/74 raw meat preparation (1.35%) and for 1/142 ready-to-eat food samples (0.7%) C. difficile was isolated only from the raw meat preparation (pork sausage). All the isolated strains were toxigenic and susceptible to all the tested antibiotics. Strains isolated from carcass samples displayed A+B+CDTa+CDTb+ profile, were toxinotype IV and belonged to the same ribotype arbitrary named TV93, while the one isolated from food samples displayed A+B+CDTa-CDTb- profile and it was not possible to determine ribotype and toxinotype, because it was lost after freeze storage. It was concluded that the prevalence of C. difficile in the pork supply chain is very low.

Raw Animal Meats as Potential Sources of Clostridium difficile in Al-Jouf, Saudi Arabia

Clostridium difficile present in feces of food animals may contaminate their meats and act as a potential source of C. difficile infection (CDI) to humans. C. difficile resistance to antibiotics, its production of toxins and spores play major roles in the pathogenesis of CDI. This is the first study to evaluate C. difficile prevalence in retail raw animal meats, its antibiotics susceptibilities and toxigenic activities in Al-Jouf, Saudi Arabia. Totally, 240 meat samples were tested. C. difficile was identified by standard microbiological and biochemical methods. Vitek-2 compact system confirmed C. difficile isolates were 15/240 (6.3%). Toxins A/B were not detected by Xpect C. difficile toxin A/B tests. Although all isolates were susceptible to vancomycin and metronidazole, variable degrees of reduced susceptibilities to moxifloxacin, clindamycin or tetracycline antibiotics were detected by Epsilon tests. C. difficile strains with reduced susceptibility to antibiotics should be investigated. Variability between the worldwide reported C. difficile contamination levels could be due to absence of a gold standard procedure for its isolation. Establishment of a unified testing algorithm for C. difficile detection in food products is definitely essential to evaluate the inter-regional variation in its prevalence on national and international levels. Proper use of antimicrobials during animal husbandry is crucial to control the selective drug pressure on C. difficile strains associated with food animals. Investigating the protective or pathogenic potential of non-toxigenic C. difficile strains and the possibility of gene transfer from certain toxigenic/ antibiotics-resistant to non-toxigenic/antibiotics-sensitive strains, respectively, should be worthy of attention.

Factors Associated with Clostridioides (Clostridium) Difficile Infection and Colonization: Ongoing Prospective Cohort Study in a French University Hospital

Introduction: Clostridioides (Clostridium) difficile can be isolated from stool in 3% of healthy adults and in at least 10% of asymptomatic hospitalized patients. C. difficile, the most common cause of hospital-acquired infectious diarrhea in the developed world, has re-emerged in recent years with increasing incidence and severity. In an effort to reduce the spread of the pathogen, published recommendations suggest isolation and contact precautions for patients suffering from C. difficile infection (CDI). However, asymptomatic colonized patients are not targeted by infection control policies, and active surveillance for colonization is not routinely performed. Moreover, given the current changes in the epidemiology of CDI, particularly the emergence of new virulent strains either in the hospital or community settings, there is a need for identification of factors associated with colonization by C. difficile and CDI. Methods and analysis: We are carrying out a prospective, observational, cohort study in Edouard Herriot Hospital, Hospices Civils de Lyon, a 900-bed university hospital in Lyon, France. All consecutive adult patients admitted on selected units are eligible to participate in the study. Stool samples or rectal swabs for C. difficile testing are obtained on admission, every 3–5 days during hospitalization, at the onset of diarrhea (if applicable), and at discharge. Descriptive and logistic regression analyses will be completed to mainly estimate the proportion of asymptomatic colonization at admission, and to evaluate differences between factors associated with colonization and those related to CDI. Ethics: The study is conducted in accordance with the ethical principles of the Declaration of Helsinki, French law, and the Good Clinical Practice guidelines. The study protocol design was approved by the participating units, the ethics committee and the hospital institutional review board (Comité de protection des personnes et Comission Nationale de l’Informatique et des Libertés; N°: 00009118). Dissemination: The results of this study will be disseminated by presenting the findings locally at each participating ward, as well as national and international scientific meetings. Findings will be shared with interested national societies crafting guidelines in CDI.

Complete Genetic Analysis of Plasmids Carrying mcr-1 and Other Resistance Genes in Avian Pathogenic Escherichia coli Isolates from Diseased Chickens in Anhui Province in China

Antimicrobial resistance associated with colistin has emerged as a significant concern worldwide, threatening the use of one of the most important antimicrobials for treating human disease. This study aimed to investigate the prevalence of colistin-resistant avian-pathogenic Escherichia coli (APEC) and shed light on the possibility of transmission of mcr-1 (mobilized colistin resistance)-positive APEC. A total of 72 APEC isolates from Anhui Province in China were collected between March 2017 and December 2018 and screened for the mcr-1 gene. Antimicrobial susceptibility testing was performed using the broth dilution method. Pulsed-field gel electrophoresis, Southern blot analysis, and conjugation assay were performed to determine the location and conjugative ability of the mcr-1 gene. Whole-genome sequencing and analysis were performed using Illumina MiSeq and Nanopore MinION platforms. Three APEC isolates (AH25, AH62, and AH65) were found to be positive for the mcr-1 gene and showed multidrug resistance. The mcr-1 genes were located on IncI2 plasmids, and conjugation assays revealed that these plasmids were transferrable. Notably, strains AH62 and AH65, both belonging to ST1788, were collected from different places but carried the same drug resistance genes and shared highly similar plasmids. This study highlights the potential for a possible epidemic of mcr-1-positive APEC and the urgent need for continuous active monitoring.

IMPORTANCE In this study, three plasmids carrying mcr-1 were isolated and characterized from APEC isolates from Anhui Province in China. The mcr-1 genes were located on IncI2 plasmids, and these plasmids were transferrable. These three IncI2 plasmids had high homology with the plasmids harbored by pathogenic bacteria isolated from other species. This finding showed that IncI2 plasmids poses a risk for the exchange of genetic material between different niches. Although colistin has been banned for use in food-producing animals in China, the coexistence of the broad-spectrum β-lactamase and mcr-1 genes on a plasmid can also lead to the stable existence of mcr-1 genes. The findings illustrated the need to improve the monitoring of drug resistance in poultry systems so as to curb the transmission or persistence of multidrug-resistant bacteria.

Detection and pathogenic potential of Clostridium difficile in commercial meat and meat products in Brazil

The aims of this study were to evaluate the occurrence of Clostridium difficile in commercial raw meat and meat products commercialized in Brazil, and to determine the pathogenic potential and antimicrobial susceptibility of the isolates. After selective enrichment, the isolation of C. difficile involved plating with and without an alcohol shock treatment onto C. difficile moxalactam agar (CDMNA). The toxigenic profile was determined through PCR for detection of tcdA, tcdB, cdtA and cdtB genes and an enzyme-linked immunosorbent assay for toxin A/B. C. difficile was isolated from 8.9% (17 out of 192) of analyzed samples. Plating without alcohol treatment (sensitivity of 88.23%) was more efficient than with alcohol treatment (sensitivity of 29.41%) in C. difficile isolation. The profile A + B+CDT- was observed in 35.0% (28/80) of the isolates. The A/B toxin was tested in 44 isolates and 15.9% of them were positive. Resistance to clindamycin, ceftizoxime tetracycline, metronidazole, vancomycin, and ceftriaxone were observed among isolates. Multi-drug resistance was detected in 36.4% (8/22) of the isolates evaluated.

Occurrence of Clostridioides (Clostridium) difficile in Poultry Giblets at Slaughter and in Retail Pork and Poultry Meat in Southeastern Spain

ABSTRACT

Raw meat and meat products contaminated with Clostridioides difficile could be a vehicle for spreading community-associated C. difficile infection. This study was conducted to determine the occurrence of C. difficile in pork and poultry meat samples (n = 325) from retail establishments and in edible giblet samples (n = 36) from a poultry processing plant in Murcia (southeastern Spain). C. difficile was isolated after selective enrichment from 2% (6 of 361) of the samples, all of which were from the poultry processing plant. These isolates were recovered from 17% (6 of 36) of the edible chicken giblets, i.e., 28% (5 of 18) of the gizzard samples and 6% (1 of 18) of the liver samples. All six C. difficile isolates were negative for toxin A and B genes by PCR assay. These findings indicate that C. difficile can survive in the gastric acid of the chicken gizzard and could be transmitted to other meat products. However, the very low prevalence of C. difficile in the tested samples indicates that retail meat may not be an important source for transmission of C. difficile to humans.

HIGHLIGHTS

Antibiotic Resistance Characteristics and Prevalence in Kitfo, an Ethiopian Beef Tartar

ABSTRACT

Kitfo is a version of beef tartar widely consumed in the Ethiopian community. It is made from raw minced beef and a blend of powdered spice and butter. Although previous studies have shown that kitfo contains several bacteria that are of public health concern, the status of their antibiotic resistance is not known. In this study, the antibiotic resistance of bacterial isolates from 26 retail kitfo samples obtained from the Washington metropolitan area was analyzed. Characterization and antibiotic sensitivity of the isolates were determined by the Vitek 2 system and pulsed-field gel electrophoresis was used to delineate the intraspecies variations. Of the isolates, 59% were resistant to two or more antibiotics. Acinetobacter calcoaceticus and Pseudomonas luteola were multidrug resistant to the classes of β-lactam, cephalosporins, and nitrofurantoin. The antibiotic susceptibility profile of the isolates was cefazolin (59%), cefoxitin (50%), ampicillin (32%), and nitrofuran (18%). Most isolates (75%) were Enterobacteriaceae, whereas only 3.8 and 2.6% were Pseudomonadaceae and Moraxellaceae, respectively. Of the Enterobacteriaceae, Enterobacter cloacae, Escherichia coli, and Klebsiella spp. were the most predominant. All isolates except Klebsiella spp. showed high genetic variation (>65%). This study implicates for the first time kitfo as a potential reservoir of antibiotic-resistant bacteria.

HIGHLIGHTS

Prevalence and phylogenetic relationship of Clostridioides difficile strains in fresh poultry meat samples processed in different cutting plants

Clostridioides difficile is one of the most frequent causes of nosocomial infections in humans leading to (antibiotic-associated) diarrhea and severe pseudomembranous colitis. With an increasing frequency, C. difficile infections (CDI) are also observed independently of hospitalization and the age of the patients in an ambulant setting. One potential source of so-called community-acquired CDI is a zoonotic transmission to humans based on direct contact with animals or the consumption of food. To estimate the exposure of humans with C. difficile via food, we screened 364 different retail fresh poultry meat products purchased in Berlin and Brandenburg, Germany and further characterized the isolates. None of the 42 turkey or chicken meat samples without skin was contaminated. However, 51 (15.8%) of 322 tested fresh chicken meat samples with skin were C. difficile-positive. The vast majority (84.3%) of all isolates exhibited toxin genes tcdA and tcdB, whereas the binary toxin cdtA/B was absent. Most of the isolates (50/51) were susceptible to all six investigated antimicrobials. However, one non-toxigenic strain was multidrug resistant to the antimicrobials clindamycin and erythromycin. The isolates were mainly represented by PCR-ribotypes (RT) 001, RT002, RT005, and RT014, which were already associated with human CDI cases in Germany and were partially detected in poultry. The relatively high contamination rate of fresh retail chicken meat with skin purchased in Germany indicates chicken meat as a potential source of human infections. Moreover, we identified cutting plants with a higher rate of a C. difficile-contamination (21.4-32.8%). To compare the phylogenetic relationship of the isolated strains from certain cutting plants over several months in 2018 and 2019, we analyzed them using NGS followed by core genome MLST. Interestingly, highly related strains (0-3 alleles distance) of common clinical RT001 and RT002 isolates, as well as of the non-toxigenic RT205 isolates were detectable in same cutting plants over a period of three and 16 months, respectively.The continuous contamination with the same strain could be explained by the longterm persistence of this strain within the cutting plant (e.g., within the scalder), or with a recurring entry e.g. from the same fattening farm.

Detection, Characterization and Antibiotic Susceptibility of Clostridioides (Clostridium) difficile in Meat Products

Clostridioides (Clostridium) difficile is a Gram (+), anaerobic, spore forming, rod shaped bacterium that can produce toxin. The objective of this study is to reveal the presence of C. difficile in meat products, to analyze the ribotype diversity by PCR and to evaluate the antibiotic susceptibility of isolated strains. The organism was isolated in 22 out of 319 (6.9%) examined meat product samples and 9 out of 22 (40.9%) isolates were identified as RT027 and all isolates had the ability of toxin production. In terms of antibiotic susceptibility, all isolates were susceptive to amoxicillin-clavulanic acid, tetracycline and vancomycin and 21 (95.4%) isolates to metronidazole. On the other hand, imipenem and cefotaxim resistance was observed in all. In conclusion, the results of this comprehensive study conducted in Turkey deduced the presence of C. difficile in different meat products. Therefore, these products can be evaluated as a potential contamination source of C. difficile from animals to humans especially for elders, youngsters, long terms wide spectrum antibiotic used and immuno-suppressed individuals.

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.

Clostridioides (Clostridium) Difficile in Food-Producing Animals, Horses and Household Pets: A Comprehensive Review

Clostridioides (Clostridium) difficile is ubiquitous in the environment and is also considered as a bacterium of great importance in diarrhea-associated disease for humans and different animal species. Food animals and household pets are frequently found positive for toxigenic C. difficile without exposing clinical signs of infection. Humans and animals share common C. difficile ribotypes (RTs) suggesting potential zoonotic transmission. However, the role of animals for the development of human infection due to C. difficile remains unclear. One major public health issue is the existence of asymptomatic animals that carry and shed the bacterium to the environment, and infect individuals or populations, directly or through the food chain. C. difficile ribotype 078 is frequently isolated from food animals and household pets as well as from their environment. Nevertheless, direct evidence for the transmission of this particular ribotype from animals to humans has never been established. This review will summarize the current available data on epidemiology, clinical presentations, risk factors and laboratory diagnosis of C. difficile infection in food animals and household pets, outline potential prevention and control strategies, and also describe the current evidence towards a zoonotic potential of C. difficile infection.

Seasonality of Clostridium difficile in the natural environment

Clostridium difficile is considered the leading cause of antibiotic-associated disease worldwide. In the past decade, a large number of studies have focused on identifying the main sources of contamination in order to elucidate the complete life cycle of the infection. Hospitals, animals and retail foods have been considered as potential vectors. However, the prevalence of C. difficile in these types of samples was found to be rather low, suggesting that other contamination routes must exist. This study explores the presence of C. difficile in the natural environment and the seasonal dynamics of the bacterium. C. difficile was isolated from a total of 45 samples out of 112 collected (40.2%) on 56 sampling points. A total of 17 points were positive only during the winter sampling (30.4%), 10 were positive only during the summer sampling (17.9%) and 9 sampling points (16.1%) were positive in both summer sampling and winter sampling. Spore counts in soil samples ranged between 50 and 250 cfu/g for 24.4% of the positive samples, with the highest concentrations detected in samples collected in the forest during winter campaign (200-250 cfu/g). A total of 17 different PCR ribotypes were identified, and 15 of them had the genes coding for toxins A and B. Most of those ribotypes had not previously been found or had been isolated only sporadically (<1% of samples) from hospitals in Belgium. Regarding antimicrobial susceptibility, most of the resistant strains were found during the summer campaign. These findings bear out that C. difficile is present in the natural environment, where the bacterium undergoes seasonal variations.

Molecular epidemiology of Clostridium difficile infection in Iranian hospitals

Background

Clostridium difficile infection (CDI) is known as one of the most important causes of nosocomial infections. The main objective of this study was to evaluate the presence of Clostridium difficile in the stool of hospitalized patients with diarrhea as well as in their environments.

Methods

C. difficile isolates were characterized according to the presence of toxin genes and antibiotic resistance. Multilocus Sequence Typing Analysis (MLST) was applied for finding the genetic polymorphism and relationship among strain lineages.

Results

A total of 821 samples (574 stools and 247 swabs) were collected between April 2015 and May 2017. The prevalence of C. difficile isolates was 28.6% (164/574) in patients and 19% (47/247) in swabs taken from medical devices, hands of healthcare workers and skin patient sites. Finally, 11.5% (66/574) toxigenic C. difficile strains isolated from stool samples of inpatients and 4.4% (11/247) from hands of healthcare workers and skin patient sites. All the toxigenic isolates were inhibited by a low concentration of vancomycin (MIC < 0.5 μg/ml). About 43% (33/77) and 39% of isolates were resistant to Clindamycin and moxifloxacin respectively. All isolates were susceptible to metronidazole. Toxigenic C. difficile strains were analyzed by MLST and were divided into 4 different STs. The detected types were ST-54 (57.9%), followed by ST-2 (31.6. %), ST-15 (5.3%) and ST-37 (5.3%), while none of the isolates were identified as ST-1 or ST-11. Significant risk factors for CDI appear to be advanced age, undergoing chemotherapy, previous surgery, and residence in the nursing home.

Conclusions

CDI is common in Iran and further studies are recommended to monitor its epidemiological variations. Moreover, greater attempts must be made to encourage antibiotic stewardship by healthcare workers and the public.

Prevalence, genotype and antimicrobial resistance of Clostridium difficile isolates from healthy pets in Eastern China

BACKGROUND

Clostridium difficile (C. difficile) is a main cause of antibiotic-associated diarrhoea in humans. Several studies have been performed to reveal the prevalence rate of C. difficile in cats and dogs. However, little is known about the epidemiology of C. difficile in healthy pets in China. This study aimed to assess the burden of C. difficile shedding by healthy dogs and cats in China. Furthermore, the genetic diversity and antimicrobial susceptibility patterns of the recovered isolates were determined.

METHODS

A total of 175 faecal samples were collected from 146 healthy dogs and 29 cats. C. difficile strains were isolated and identified from the feces of these pets. The characterized C. difficile strains were typed by multilocus sequence typing (MLST), and the MICs of the isolates were determined against ampicillin, clindamycin, tetracycline, moxifloxacin, chloramphenicol, cefoxitin, metronidazole and vancomycin by the agar dilution method.

RESULTS

Overall, 3 faecal samples (1.7%) were C. difficile culture positive. One sample (0.7%) from a dog was C. difficile culture positive, while two cats (7.0%) yielded positive cultures. The prevalence rate differed significantly between cats and dogs. These isolates were typed into 3 MLST genotypes and were susceptible to chloramphenicol, tetracycline, metronidazole and moxifloxacin and resistant to ampicillin, clindamycin and cefoxitin. Notably, one strain, D141-1, which was resistant to three kinds of antibiotics and carried toxin genes, was recovered in the faeces of a healthy dog.

CONCLUSION

Our results suggest that common pets may be a source of pathogenic C. difficile, indicating that household transmission of C. difficile from pets to humans can not be excluded.

Prevalence of Clostridium difficile Isolated from Beef and Chicken Meat Products in Turkey

The concern about the possibility of food can be a vehicle for the transmission of Clostridium difficile to humans has been raised recently due to the similarities among the strains isolated from patients, foods and food animals. In this study, therefore, the prevalence of C. difficile was investigated in beef and chicken meat products collected from 57 different butcher shops, markets and fast food restaurants in Sakarya province of Turkey. Two out of 101 samples (1.98%) was positive for C. difficile indicating a very low prevalence. The pathogen was isolated from an uncooked meatball sample and a cooked meat döner sample, whereas not detected in chicken meat samples. The meatball isolate was resistant to vancomycin and tetracycline, while the cooked meat döner isolate was resistant to vancomycin and metronidazole. Both isolates were sensitive to moxifloxacin and clindamycin. Toxins A and B were not detected. This study reveals the presence of C. difficile in further processed beef products in Turkey.

Detection of antibiotic resistance toxigenic Clostridium difficile in processed retail lettuce

Objectives: Clostridium difficile is the major cause of infectious diarrhoea in humans after antimicrobial treatment. Clostridium difficile has been isolated from food animals and meat. The main purpose of this study was to characterize C. difficile isolated from retail lettuce and determine the antibiotic resistance using five common clinical-selected antibiotics (metronidazole, vancomycin, clindamycin, erythromycin, and cefotaxime).

Materials and Methods: Lettuce samples (grown in California, Arkansas, and Louisiana) were purchased from retail stores.

Results: Toxigenic C. difficile was isolated from 13.8 per cent (41/297) of the lettuce samples. Among the toxigenic isolates, only 82.9 per cent (34/41) produced toxin B, 17.1 per cent (7/41) produced both toxin A and toxin B, and two of the Louisiana C. difficile isolates were identified as ribotype 027. Under the treatment of the five antibiotics, the virulence C. difficile isolates were identified as having antibiotic resistance to metronidazole, vancomycin, and erythromycin.

Conclusion: The present study reports the highest prevalence of toxigenic C. difficile in US retail lettuce. The antibiotic resistance to metronidazole, vancomycin, and erythromycin of the isolated C. difficile from retail lettuces could lead to public health concerns.

Laboratory identification of anaerobic bacteria isolated on Clostridium difficile selective medium

Despite increasing interest in the bacterium, the methodology for Clostridium difficile recovery has not yet been standardized. Cycloserine-cefoxitin fructose taurocholate (CCFT) has historically been the most used medium for C. difficile isolation from human, animal, environmental, and food samples, and presumptive identification is usually based on colony morphologies. However, CCFT is not totally selective. This study describes the recovery of 24 bacteria species belonging to 10 different genera other than C. difficile, present in the environment and foods of a retirement establishment that were not inhibited in the C. difficile selective medium. These findings provide insight for further environmental and food studies as well as for the isolation of C. difficile on supplemented CCFT.

Agricultural Applications for Antimicrobials. A Danger to Human Health: An Official Position Statement of the Society of Infectious Diseases Pharmacists

The use of antibiotics in agriculture, particularly in food-producing animals, is pervasive and represents the overwhelming majority of antibiotic use worldwide. The link between antibiotic use in animals and antibiotic resistance in humans is unequivocal. Transmission can occur by ingesting undercooked meats harboring resistant bacteria, by direct contact of animals by animal handlers, and by various other means. Antibiotics used in aquaculture and antifungals used in horticulture are also an evolving threat to human health. Regulations aimed at decreasing the amount of antibiotics used in food production to limit the development of antibiotic resistance have recently been implemented. However, further action is needed to minimize antibiotic use in agriculture. This article describes the extent of this current problem and serves as the official position of the Society of Infectious Diseases Pharmacists on this urgent threat to human health.

Clostridium perfringens: Comparative effects of heat and osmotic stress on non-enterotoxigenic and enterotoxigenic strains

Clostridium perfringens isolates associated with food poisoning carries a chromosomal cpe gene, while non-foodborne human gastrointestinal disease isolates carry a plasmid cpe gene. The enterotoxigenic strains tested produced vegetative cells and spores with significantly higher resistance than non-enterotoxigenic strains. These results suggest that the vegetative cells and spores have a competitive advantage over non-enterotoxigenic strains. However, no explanation has been provided for the significant associations between chromosomal cpe genotypes with the high resistance, which could explain the strong relationship between chromosomal cpe isolates and C. perfringens type A food poisoning. Here, we analyse the action of physical and chemical agent on non-enterotoxigenic and enterotoxigenic regional strains. And this study tested the relationship between the sensitivities of spores and their levels SASPs (small acid soluble proteins) production in the same strains examined.

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.

Clostridium difficile with Moxifloxacin/Clindamycin Resistance in Vegetables in Ohio, USA, and Prevalence Meta-Analysis

We (i) determined the prevalence of Clostridium difficile and their antimicrobial resistance to six antimicrobial classes, in a variety of fresh vegetables sold in retail in Ohio, USA, and (ii) conducted cumulative meta-analysis of reported prevalence in vegetables since the 1990s. Six antimicrobial classes were tested for their relevance as risk factors for C. difficile infections (CDIs) (clindamycin, moxifloxacin) or their clinical priority as exhaustive therapeutic options (metronidazole, vancomycin, linezolid, and tigecycline). By using an enrichment protocol we isolated C. difficile from three of 125 vegetable products (2.4%). All isolates were toxigenic, and originated from 4.6% of 65 vegetables cultivated above the ground (n = 3; outer leaves of iceberg lettuce, green pepper, and eggplant). Root vegetables yielded no C. difficile. The C. difficile isolates belonged to two PCR ribotypes, one with an unusual antimicrobial resistance for moxifloxacin and clindamycin (lettuce and pepper; 027-like, A⁺B⁺CDT⁺; tcdC 18 bp deletion); the other PCR ribotype (eggplant, A⁺B⁺ CDT⁻; classic tcdC) was susceptible to all antimicrobials. Results of the cumulative weighted meta-analysis (6 studies) indicate that the prevalence of C. difficile in vegetables is 2.1% and homogeneous (P < 0.001) since the first report in 1996 (2.4%). The present study is the first report of the isolation of C. difficile from retail vegetables in the USA. Of public health relevance, antimicrobial resistance to moxifloxacin/clindamycin (a bacterial-associated risk factor for severe CDIs) was identified on the surface of vegetables that are consumed raw.