Clostridium perfringens and Clostridium difficile in cooked beef sold in Côte d'Ivoire and their antimicrobial susceptibility

Microbiology of street food: understanding risks to improve safety

Street foods play important socioeconomic and cultural roles and are popular worldwide. In addition to providing convenient and low-cost meals for urban populations, street food offers an essential source of income for vendors, especially women, and it can reflect traditional local culture, which is an important attraction for tourists. Despite these benefits, the microbiological safety of street food has become a worldwide concern because it is often prepared and sold under inadequate safety conditions, without legal control and sanitary surveillance. Consequently, high counts of fecal indicator bacteria and several foodborne pathogens have been detected in street foods. This review provides insight into the microbiology of street food, focus on the associated microbiological safety aspects and main pathogens, and the global status of this important economic activity. Furthermore, the need to apply molecular detection rather than traditional culture-based methods is discussed to better understand the actual risks of microbial infection associated with street foods. Recognition is always the first step toward addressing a problem.

Prevalence and Characterisation of Clostridium perfringens Isolates in Food-Producing Animals in Romania

The aim of the current study was to investigate the prevalence of Clostridium perfringens (C. perfringens) recovered from animal faeces, as well as to determine the antimicrobial susceptibility of such isolates. A total of 14 (14/100; 14%) C. perfringens isolates were isolated from the 100 analysed samples (twelve recovered from faecal samples collected from pigs and two from veal calves' faecal samples). The preponderant genotype was type A, with all isolates being cpa-positive. The most potent antimicrobial agents against C. perfringens proved to be vancomycin, rifampicin and lincomycin. A strong resistance to tetracycline (71.4%), penicillin (64.2%), erythromycin (42.8%) and enrofloxacin (35.7%) was also observed. To the best of our knowledge, this is the first analysis regarding the prevalence, characterization and antimicrobial susceptibility of C. perfringens in food-producing animals in Romania, adding further evidence for the probable role of animals as a source of resistant C. perfringens strains.

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.

The Environment, Farm Animals and Foods as Sources of Clostridioides difficile Infection in Humans

The recent discovery of the same Clostridioides difficile ribotypes associated with human infection in a broad range of environments, animals and foods, coupled with an ever-increasing rate of community-acquired infections, suggests this pathogen may be foodborne. The objective of this review was to examine the evidence supporting this hypothesis. A review of the literature found that forty-three different ribotypes, including six hypervirulent strains, have been detected in meat and vegetable food products, all of which carry the genes encoding pathogenesis. Of these, nine ribotypes (002, 003, 012, 014, 027, 029, 070, 078 and 126) have been isolated from patients with confirmed community-associated C. difficile infection (CDI). A meta-analysis of this data suggested there is a higher risk of exposure to all ribotypes when consuming shellfish or pork, with the latter being the main foodborne route for ribotypes 027 and 078, the hypervirulent strains that cause most human illnesses. Managing the risk of foodborne CDI is difficult as there are multiple routes of transmission from the farming and processing environment to humans. Moreover, the endospores are resistant to most physical and chemical treatments. The most effective current strategy is, therefore, to limit the use of broad-spectrum antibiotics while advising potentially vulnerable patients to avoid high-risk foods such as shellfish and pork.

Prevalence, Antimicrobial Resistance and Toxin-Encoding Genes of Clostridioides difficile from Environmental Sources Contaminated by Feces

Clostridioides difficile (C. difficile) is the most common pathogen causing antibiotic-associated intestinal diseases in humans and some animal species, but it can also be present in various environments outside hospitals. Thus, the objective of this study was to investigate the presence and the characteristics of toxin-encoding genes and antimicrobial resistance of C. difficile isolates from different environmental sources. C. difficile was found in 32 out of 81 samples (39.50%) after selective enrichment of spore-forming bacteria and in 45 samples (55.56%) using a TaqMan-based qPCR assay. A total of 169 C. difficile isolates were recovered from those 32 C. difficile-positive environmental samples. The majority of environmental C. difficile isolates were toxigenic, with many (88.75%) positive for tcdA and tcdB. Seventy-four isolates (43.78%) were positive for binary toxins, cdtA and cdtB, and 19 isolates were non-toxigenic. All the environmental C. difficile isolates were susceptible to vancomycin and metronidazole, and most isolates were resistant to ciprofloxacin (66.86%) and clindamycin (46.15%), followed by moxifloxacin (13.02%) and tetracycline (4.73%). Seventy-five isolates (44.38%) showed resistance to at least two of the tested antimicrobials. C. difficile strains are commonly present in various environmental sources contaminated by feces and could be a potential source of community-associated C. difficile infections.

Clostridium perfringens associated with dairy farm systems show diverse genotypes

Clostridium perfringens is a bacterial species of importance to both public and animal health. Frequently found in food system environments, it presents a risk to food animal health such as dairy herds, and may cross contaminate associated ingredients or food products, with potential to cause sporadic and outbreaks of disease in human populations, including gastroenteric illness. In this study, we characterized C. perfringens isolated from bovine, caprine, and ovine dairy farm systems (n = 8, 11 and 4, respectively). Isolates were phenotypically screened for antimicrobial sensitivity profiling, and subjected to whole genome sequencing to elucidate related genetic markers, as well as examine virulence gene markers, mobile genetic elements, and other features. Both toxin type A and type D isolates were identified (78 % and 22 % of isolates, respectively), including 20 novel sequence types. Resistance to clindamycin was most prevalent among antibiotics screened (30 %), followed by erythromycin (13 %), then penicillin and tetracycline (4 %), although an additional 3 isolates were non-susceptible to tetracycline. Most isolates harboured plasmids, which mobilised virulence markers such as etx, cpb2, and resistance markers tetA(P), tetB(P), and erm(Q), on conjugative plasmids. The presence of type D isolates on caprine farms emphasizes the need for control efforts to prevent infection and potential enterotoxemia. Clostridium perfringens enterotoxin (cpe) was not identified, suggesting lower risk of gastrointestinal illness from contaminated foods, the presence of other virulence and antimicrobial resistance markers suggests farm hygiene remains an important consideration to help ensure food safety of associated dairy foods produced.

Presence of Clostridioides difficile in cattle feces, carcasses, and slaughterhouses: Molecular characterization and antibacterial susceptibility of the recovered isolates

The aims of this study were to isolate and identify Clostridioides difficile from cattle feces and carcasses, and slaughterhouse samples, and to determine the molecular characteristics and antibacterial susceptibility of the recovered isolates. A total of 220 samples, including 100 cattle fecal samples, 100 cattle carcass surface samples, and 20 slaughterhouse samples were used as the study material. In total, 12 (5.45%) samples, including 11 (11%) cattle fecal samples and 1 (5%) slaughterhouse sample, were found to be positive for C. difficile. On the other hand, all of the carcass samples were negative for C. difficile. A total of 11 (91.66%) isolates, including 10 fecal isolates and 1 slaughterhouse wastewater isolate, were found to be positive for the presence of the toxin genes tcdA and tcdB, whilst 1 fecal isolate was found to be negative for both genes. In addition, 3 different ERIC-PCR profiles were identified in the 11 fecal isolates. The ERIC-PCR profile of the slaughterhouse wastewater isolate was found to be similar to one of the ERIC-PCR profiles obtained from the fecal isolates. All of the isolates were resistant to ciprofloxacin and levofloxacin. Considering that the agent is a spore-forming bacterium shed in feces, the detection of C. difficile isolates of different genotypes, some carrying toxin genes, suggests that feces and slaughterhouse wastewater carrying this bacterium may pose a risk for the contamination of carcasses. The current study revealed that hygiene conditions should be performed to the maximum extent in slaughterhouses.

Clostridioides difficile infection in Africa: A narrative review

Clostridioides (Clostridium) difficile infection (CDI) places a burden on healthcare facilities worldwide. Most research studies have been concentrated in high-income countries in North America, Europe, Asia and Australia, where C. difficile is the leading cause of diarrhoea associated with antimicrobial use. This narrative review summarises African CDI studies, focussing on reports published in the last 20 years. Although relatively sparse, the data suggest that CDI is an important cause of diarrhoea on the continent. African CDI patient populations are often younger than in European and North American settings, probably due to the high prevalence of co-morbid conditions such as tuberculosis, particularly in sub-Saharan Africa. Strain typing data are rare and where reported generally limited to single sites and institutions. Despite challenges, including a lack of facilities and awareness, there is a need for further investigation to more accurately determine the true burden of disease caused by C. difficile in Africa.

Prevalence, Antibiotic Resistance, Toxin-Typing and Genotyping of Clostridium perfringens in Raw Beef Meats Obtained from Qazvin City, Iran

Background: Clostridium perfringens is one of the highest prevailing spore-forming foodborne pathogens, which is widely distributed and causes severe disease and outbreaks in humans and animals. Raw meat and poultry are the main vehicles of this pathogen. In this study, we investigated the prevalence, antibiotic resistance pattern, toxin-encoding genes and genetic diversity of C. perfringens isolates from raw whole and minced meat samples purchased from local markets in Qazvin city, Iran (the source of beef cattle production was also located in Qazvin city, Iran). Methods: We used conventional culture-based and Kirby–Bauer disk diffusion and conventional and arbitrary primer PCR methods. Results: A total of 18 C. perfringens strains were isolated from 133 raw meat samples (13.53%). Up to 44.4 and 55.5% of these isolates were detected in raw minced and whole meat samples, respectively. We found that 72.2, 66.6, 61.1, 37.8 and 33.3% of the C. perfringens isolates were resistant to ampicillin, tetracycline, amoxicillin, ciprofloxacin and chloramphenicol antibiotics, respectively. Multidrug resistance was found in 38% of the isolates. Among the four main toxin genes evaluated, the Cpa gene was detected in all isolates, and 61.1% of the isolates were mostly recognized as type A C. perfringens. High levels of genetic diversity were observed among the isolates, and they were classified into five distinct groups. Conclusions: The isolates from whole meat samples were more resistant to antibiotics. However, toxin genes were more detected in the isolates from minced meat samples. Our findings suggest that contamination of raw meat products with multidrug resistant C. perfringens could be regarded as one of the concerning pathogens in these products. Comprehensive monitoring of C. perfringens isolates is strongly recommended.

Effect of Doxycycline in Decreasing the Severity of Clostridioides difficile Infection in Mice

Background: Doxycycline possesses antibacterial activity against Clostridioides difficile and anti-inflammatory effects. Materials and Methods: The influence of doxycycline on the development of CDI was studied in an established animal model of CDI using C57BL/6 mice. Results: Mice intraperitoneally administered doxycycline had higher cecum weight (1.3 ± 0.1 vs. 0.5 ± 0.1 g; p < 0.001) and less body weight reduction (0.7 ± 0.5 g vs. −17.4 ± 0.2 g; p < 0.001) than untreated mice infected with C. difficile. Oral doxycycline, metronidazole, or vancomycin therapy resulted in less body weight reduction in mice with CDI than in untreated mice (1.1 ± 0.1 g, 1.3 ± 0.2 g, 1.2 ± 0.1 g, vs. 2.9 ± 0.3 g; p < 0.001). Doxycycline therapy led to lower expression levels of inflammatory cytokines, such as macrophage inflammatory protein-2 (0.4 ± 0.1 vs. 2.9 ± 1.3, p = 0.02), and higher levels of zonula occludens-1 (1.2 ± 0.1 vs. 0.8 ± 0.1, p = 0.02) in colonic tissues than in untreated mice. Conclusions: Concurrent intraperitoneal administration of doxycycline and oral C. difficile challenge does not aggravate the disease severity of CDI, and oral doxycycline may be a potential therapeutic option for CDI.

Prevalence and characterization of Clostridium perfringens isolated from different chicken farms in China

Clostridium perfringens (C. perfringens) is a common pathogenic microorganism present in nature, which can cause animal and human diseases, such as necrotizing enteritis (NE) in poultry. Little is known about the current prevalence status of C. perfringens from poultry farms of different types and regions in China. From December 2018 to August 2019, we investigated the prevalence, genotype distribution and drug resistance of C. perfringens from Guangdong, Pingyin, Tai'an and Weifang. A total of 622 samples were collected and processed for C. perfringens isolation, among which 239 (38.42%) samples were determined to be positive for C. perfringens. A total of 312 isolates of C. perfringens were recovered (1-5 strains were isolated for each positive sample), and 98.72% of the isolates were identified as type A, while the others were type F. Antimicrobial susceptibility testing revealed that 47.71% of the isolates were resistant to at least five classes of commonly used antibiotics. Multilocus sequence typing (MLST) showed that 74 representative isolates were divided into 63 sequence types (STs), and the Simpson's diversity index (Ds) of the STs for the five farms was 0.9799. 37.84% of the isolates were classified into seven clonal complexes (CC1-CC7), and the isolates from the same farm were more concentrated in the minimum spanning tree. In addition, some cloaca isolates and feed isolates were distributed in the same ST or CC; this result indicates that the C. perfringens in chicken can come from the environment (feed etc.).

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.

Evaluation and Optimization of Antibiotics Resistance Profile against Clostridium perfringens from Buffalo and Cattle in Pakistan

Clostridium perfringens is a serious threat to successful bovine farming. It causes severe damage to the buffalo and cattle health causing a drastic reduction in milk and meat production. In Pakistan, C. perfringens is a constant threat, and for its management, antibiotics are mostly used. Most bovine farmers use a single antibiotic to suppress the bacterial infection which in turn, increases the antimicrobial resistance (AMR) against the particular antibiotic. To reduce the resistance, the administration of multiple antibiotics in their standard doses at different times can be a possible remedy to manage the AMR and reduce their viability. This study aims to evaluate the effect of 11 commonly used antibiotics at their standard concentrations for inhibiting 33 strains of C. perfringens from five districts of Punjab province in Pakistan. Based on the zone of inhibition, ciprofloxacin, ampicillin, and cefotaxime (CAC) at their standard concentrations effectively inhibited the bacterium. These antibiotics showed appropriate significance statistically, i.e., correlation, Chi-square test, and cluster analysis. Optimization of these antibiotics using response surface methodology (RSM) revealed that the selected antibiotics from medium to high range not only reduce the bacterial propagation but also their population up to a considerable extent. Hence, the health of milk- and meat-producing large animals could be improved, which will be cost-effective and less harmful to the animal, human health, and the environment. Moreover, optimized administration of the selected antibiotics would reduce the impact of drug-resistant superbugs.

Isolation and characterization of a multidrug-resistant Clostridioides difficile toxinotype V from municipal wastewater treatment plant

PURPOSE

Wastewater treatment plant (WWTP) is regarded as a potential source for transmission of Clostridioides difficile from urban areas into the surface water, through feces of human and animals. The aim of this study was to screen and characterize the C. difficile bacteria in inlet and outlet wastewater of different WWTPs in Tehran, Iran.

METHODS

Totally, 72 samples were collected from three different WWTPs (inlet site and outlet sites) during a year. C. difficile was isolated and characterized in terms of toxins, toxinotype, resistance profile and genes, and colonization factors using PCR.

RESULTS

One C. difficile toxinotype V was isolated from the outlet samples. The isolate was susceptible to vancomycin but resistant to metronidazole, tetracycline, ciprofloxacin, and moxifloxacin using MIC Test Strips. The isolated C. difficile was toxigenic (tcdA, tcdB, cdtA, cdtB positive and CPE positive) and had tcdC-A genotype. No mutations were found in fliC and fliD. The slpA sequence type was 078 - 01. The C. difficile was positive for tetM, int, but negative for vanA, nim, and tndX genes. Mutations were not observed in gyrA and gyrB genes.

CONCLUSIONS

This study provided evidence of presence of a multidrug-resistant C. difficile toxinotype V in one of the municipal WWTP. The transmission of such isolate to the environment and reuse of treated wastewater by human pose a threat to human health and dissemination of antibiotic resistant bacteria which are untreatable.

Prevalence and characterization of Clostridium perfringens isolated from feces of captive cynomolgus monkeys (Macaca fascicularis)

Clostridium perfringens is ubiquitous in the environment and the gastrointestinal tract of warm-blooded animals. While part of the gut microbiome, abnormal growth of C. perfringens causes histotoxic, neurologic, and enteric diseases in a variety of animal species, including humans, due to the production of toxins. There is extremely limited information on C. perfringens infection in non-human primates. Presently, 10 strains were successfully isolated from 126 monkeys and confirmed by molecular and biochemical analyses. All isolates were genotype A based on molecular analysis. Alpha toxin was identified in all isolates. Beta 2 toxin was detected in only three isolates. No other toxins, including enterotoxin, beta, iota, epsilon, and net B toxin, were identified in any isolate. All isolates were highly susceptible to β-lactam antibiotics. Double hemolysis and lecithinase activity were commonly observed in all strains. Biofilm formation, which can increase antibiotic resistance, was identified in 90% of the isolates. The data are the first report the prevalence and characteristics of C. perfringens isolated from captive cynomolgus monkeys.

Quantitative microbial risk assessment for Clostridium perfringens foodborne illness following consumption of kimchi in South Korea

The purpose of this study was to conduct a risk assessment for Clostridium perfringens foodborne illness via kimchi consumption in South Korea. Prevalence of C. perfringens in kimchi, kimchi consumption amount and frequency, and distribution conditions (time and temperature) from manufacture to the home were determined. C. perfringens initial contamination level was estimated using Beta distribution [Beta (6, 79)]. Potential C. perfringens cell counts during distribution were predicted using the Weibull model (primary models, R ² = 0.923-0.953) and a polynomial model [(δ = 1/(0.2385 + (- 0.0307 × Temp) + (0.0011 × Temp²)), R ² = 0.719]. Average daily consumption data was assessed using Gamma distribution [1.0444, 91.767, RiskShift (0.16895), RiskTruncate (0, 1078)]. The mean risk of C. perfringens-associated foodborne illness following kimchi consumption was found to be 1.21 × 10^-17. These results suggest that the risk of C. perfringens foodborne illness from kimchi consumption, under current conditions, can be considered to be very low in S. Korea.

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.

Antimicrobial Resistance in Clostridium and Brachyspira spp. and Other Anaerobes

This article describes the antimicrobial resistance to date of the most frequently encountered anaerobic bacterial pathogens of animals. The different sections show that antimicrobial resistance can vary depending on the antimicrobial, the anaerobe, and the resistance mechanism. The variability in antimicrobial resistance patterns is also associated with other factors such as geographic region and local antimicrobial usage. On occasion, the same resistance gene was observed in many anaerobes, whereas some were limited to certain anaerobes. This article focuses on antimicrobial resistance data of veterinary origin.

Characterization of Clostridioides difficile isolates recovered from hospitalized patients and the hospitals environment and air: A multicenter study

In healthcare settings, contamination of environment with toxigenic and hypervirulent Clostridioides difficile strains is a serious concern. Here, we assessed whether patients with C. difficile have a role to play in the dissemination of C. difficile in our settings or other sources are implicated in its circulation. A total of 700 fecal specimens and 1435 environmental samples from surfaces, equipment and air of rooms occupied by patients suspected of C. difficile infection were taken from 4 tertiary hospitals in Tehran, Iran between April 2016 and August 2017. Antibiotic susceptibility testing and detection of resistance genes were performed for the environmental isolates. The clinical and environmental isolates of C. difficile were subjected to Pulsed Field Gel Electrophoresis (PFGE) analysis. Forty three (6.14%) and 2 (0.13%) isolates of C. difficile were recovered from the clinical and environmental samples, respectively. In the clinical settings, 2 patients were suspected of recurrent C. difficile infection. Thirty distinct pulsotypes were found among the C. difficile isolates including 28 singletons and 2 common types. One of the two environmental isolates was isolated from floor in the Medical ward, of pulsotype/ribotype/toxinotype PT10/New ribotype/toxinotype V, harbored cdtA/B and tcdC-A, and resistant to ciprofloxacin. The other one was isolated from air of a room in ICU, assigned to PT11/RT001/toxinotype 0, belonged to tcdC-sc3 genotypes and resistant to metronidazole. The environmental isolates did not generate amplicons in PCR assays targeting vanA and nim genes. This study provided evidence for dissemination of genetically diverse strains of C. difficile in hospitalized patients, presence of C. difficile in hospital air, existence of binary toxin positive/antibiotic-resistant isolate on the floor and intra-hospital dissemination of this pathogen.

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.

Diversity of toxin genotypes and antimicrobial susceptibility of Clostridium perfringens isolates from feces of infants

Introduction

This study investigated the most important epidemiological characteristics of C. perfringens strains colonizing the intestine of Jordanian infants.

Methods

A total of 302 fecal samples were collected from Jordanian infants aged ≤ 1 year from patients hospitalized in the neonatal intensive care unit and from the outpatient department. Samples were cultured for detection of C. perfringens and evaluation of their antimicrobial resistance; identification of their potential toxins genes was performed using PCR.

Results

Overall the C. perfringens colonization rate was 27.2% (82/302). Infants aged ≤ 6 months showed significantly higher (p<0.004) colonization than older infants. The occurrence rates of C. perfringens isolates carrying potential specific toxin genes were as follows: alpha toxin 95.1% (78/82), beta-2 toxin 69.5% (57/82), beta toxin 14.6% (12/82), and only 2.4% (2/82) epsilon toxin. No isolate carried the iota toxin. Genotype A was the most prevalent among C. perfringens isolates (78.1%). The antimicrobial resistance rates of C. perfringens isolates were 20% to metronidazole and erythromycin, 16.7% to levofloxacin, and 6.7% to vancomycin.

Conclusions

This study demonstrates that the majority of C. perfringens isolates from feces of Jordanian infants were classified as type A, few isolates were classified as type C and type D, and all were negative for potential enterotoxin genes causing diarrhea.

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.

Highly antibiotic-resistant Clostridium difficile isolates from Iranian patients

AIMS

Little is known about the resistance rate and susceptibility profile of Clostridium difficile isolates in Iran. Therefore, the aim of present study is to assess the rate of drug-resistant C. difficile.

METHODS AND RESULTS

During a 6-year period, four hospitals submitted 735 stool specimens from patients suspected for C. difficile infections to the anaerobic bacteriology laboratory. The 46 C. difficile isolates were subjected to disc diffusion and minimum inhibitory concentration (MIC) Test Strips. All isolates were susceptible to vancomycin (VAN) while the highly resistant phenotypes of metronidazole (MTZ) (67·4%), moxifloxacin (78·3%), ciprofloxacin (69·5%) and tetracycline (82·6%) were observed. Of more concern, 67·3% of C. difficile isolates displayed multidrug-resistant phenotypes. More than half of the isolates (n = 27, 58·6%) were coresistant to ciprofloxacin and moxifloxacin. The MIC90 of VAN was ≤2 mg l^-1 , whereas this value for MTZ, ciprofloxacin, moxifloxacin and tetracycline was higher than the resistance breakpoints. According to the comparison of interpretive categories for two tests, the categorical agreement was less than 90% for VAN, ciprofloxacin and tetracycline.

CONCLUSIONS

The disc diffusion method can be used to detect the isolates with reduced susceptibility to MTZ or moxifloxacin. The high rate of resistance to fluoroquinolones highlights the possibility of the emergence of hypervirulent strains in our settings.

SIGNIFICANCE AND IMPACT OF THE STUDY

This study provides data regarding the high level of resistance against multiple antibiotics except VAN.

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.

Molecular and culture-based diagnosis of Clostridium difficile isolates from Côte d'Ivoire after prolonged storage at disrupted cold chain conditions

BACKGROUND

Although Clostridium difficile is a major cause of diarrhoea, its epidemiology in tropical settings is poorly understood. Strain characterisation requires work-up in specialised laboratories, often after prolonged storage without properly maintained cold chain.

METHODS

We screened 298 human faecal samples from Côte d'Ivoire using a rapid test for C. difficile glutamate dehydrogenase (GDH). GDH-positive samples were aerobically stored at disrupted cold chain conditions (mean duration: 11 days) before transfer to a reference laboratory for anaerobic culture, susceptibility testing, PCR assays and ribotyping.

RESULTS

Sixteen samples (5.4%) had a positive GDH screening test. C. difficile infection was confirmed in six specimens by culture and PCR, while no nucleic acids of C. difficile were detected in the culture-negative samples. Further analysis of stool samples harbouring toxigenic C. difficile strains confirmed that both GDH and toxins remained detectable for at least 28 days, regardless of storage conditions (aerobic storage at 4°C or 20°C).

CONCLUSIONS

Storage conditions only minimally affect recovery of C. difficile and its toxins in stool culture. A rapid GDH screening test and subsequent transfer of GDH-positive stool samples to reference laboratories for in-depth characterisation may improve our understanding of the epidemiology of C. difficile in the tropics.

Doxycycline and Tigecycline: Two Friendly Drugs with a Low Association with Clostridium Difficile Infection

Clostridium difficile infection (CDI) is known to be associated with prior exposure to many classes of antibiotics. Standard therapy for CDI (i.e., metronidazole and vancomycin) is associated with high recurrence rates. Although tetracycline derivatives such as tetracycline, doxycycline or tigecycline are not the standard therapeutic choices for CDI, they may serve as an alternative or a component of combination therapy. Previous tetracycline or doxycycline usage had been shown to have less association with CDI development. Tigecycline, a broad-spectrum glycylcycline with potency against many gram-positive or gram-negative pathogens, had been successfully used to treat severe or refractory CDI. The in vitro susceptibility of C. difficile clinical isolates to tigecycline in many studies showed low minimal inhibitory concentrations. Tigecycline can suppress in vitro toxin production in both historical and hypervirulent C. difficile strains and reduce spore production in a dose-dependent manner. Tetracycline compounds such as doxycycline, minocycline, and tigecycline possess anti-inflammatory properties that are independent of their antibiotic activity and may contribute to their therapeutic effect for CDI. Although clinical data are limited, doxycycline is less likely to induce CDI, and tigecycline can be considered one of the therapeutic choices for severe or refractory CDI.

A possible route for foodborne transmission of Clostridium difficile?

Spores of toxigenic Clostridium difficile and spores of food-poisoning strains of Clostridium perfringens show a similar prevalence in meats. Spores of both species are heat resistant and can survive cooking of foods. C. perfringens is a major cause of foodborne illness; studies are needed to determine whether C. difficile transmission by a similar route is a cause of infection.

Global Phenotypic Characterization of Effects of Fluoroquinolone Resistance Selection on the Metabolic Activities and Drug Susceptibilities of Clostridium perfringens Strains

Fluoroquinolone resistance affects toxin production of Clostridium perfringens strains differently. To investigate the effect of fluoroquinolone resistance selection on global changes in metabolic activities and drug susceptibilities, four C. perfringens strains and their norfloxacin-, ciprofloxacin-, and gatifloxacin-resistant mutants were compared in nearly 2000 assays, using phenotype microarray plates. Variations among mutant strains resulting from resistance selection were observed in all aspects of metabolism. Carbon utilization, pH range, osmotic tolerance, and chemical sensitivity of resistant strains were affected differently in the resistant mutants depending on both the bacterial genotype and the fluoroquinolone to which the bacterium was resistant. The susceptibilities to gentamicin and erythromycin of all resistant mutants except one increased, but some resistant strains were less susceptible to amoxicillin, cefoxitin, ceftriaxone, chloramphenicol, and metronidazole than their wild types. Sensitivity to ethidium bromide decreased in some resistant mutants and increased in others. Microarray analysis of two gatifloxacin-resistant mutants showed changes in metabolic activities that were correlated with altered expression of various genes. Both the chemical structures of fluoroquinolones and the genomic makeup of the wild types influenced the changes found in resistant mutants, which may explain some inconsistent reports of the effects of therapeutic use of fluoroquinolones on clinical isolates of bacteria.