Stenotrophomonas riyadhensis sp. nov., isolated from a hospital floor swab.

During the analysis of a collection of Pseudomonas strains linked to an outbreak in an intensive care unit at King Faisal Specialist Hospital and Research Center in 2019, one isolate (CFS3442T) was identified phenotypically as Pseudomonas aeruginosa. However, whole-genome sequencing revealed its true identity as a member of the genus Stenotrophomonas, distinct from both P. aeruginosa and Stenotrophomonas maltophilia. The isolate demonstrated: (i) a significant phylogenetic distance from P. aeruginosa; (ii) considerable genomic differences from several S. maltophilia reference strains and other Stenotrophomonas species; and (iii) unique phenotypic characteristics. Based on the combined geno- and phenotypic data, we propose that this isolate represents a novel species within the genus Stenotrophomonas, for which the name Stenotrophomonas riyadhensis sp. nov. is proposed. The type strain is CFS3442T (=NCTC 14921T=LMG 33162T).

The need for One Health systems-thinking approaches to understand multiscale dissemination of antimicrobial resistance.

Although the effects of antimicrobial resistance (AMR) are most obvious at clinical treatment failure, AMR evolution, transmission, and dispersal happen largely in environmental settings, for example within farms, waterways, livestock, and wildlife. We argue that systems-thinking, One Health approaches are crucial for tackling AMR, by understanding and predicting how anthropogenic activities interact within environmental subsystems, to drive AMR emergence and transmission. Innovative computational methods integrating big data streams (eg, from clinical, agricultural, and environmental monitoring) will accelerate our understanding of AMR, supporting decision making. There are challenges to accessing, integrating, synthesising, and interpreting such complex, multidimensional, heterogeneous datasets, including the lack of specific metrics to quantify anthropogenic AMR. Moreover, data confidentiality, geopolitical and cultural variation, surveillance gaps, and science funding cause biases, uncertainty, and gaps in AMR data and metadata. Combining systems-thinking with modelling will allow exploration, scaling-up, and extrapolation of existing data. This combination will provide vital understanding of the dynamic movement and transmission of AMR within and among environmental subsystems, and its effects across the greater system. Consequently, strategies for slowing down AMR dissemination can be modelled and compared for efficacy and cost-effectiveness.

Detection of hepatitis E RNA in pork products at point of retail in Ireland - Are consumers at risk?

Hepatitis E (HEV), a zoonotic virus, is the leading cause of acute viral hepatitis in Europe. The presence of HEV in domestic pigs can result in infections in humans through consumption of pork products which are undercooked or where processing methods are insufficient to inactivate the virus. In Ireland, pork accounts for 34 % of all meat consumption (CSO, 2022) and the prevalence of HEV in products at point of retail has not previously been characterised. A sampling strategy was designed in which high pork content sausages, fresh pork liver and raw fermented sausages were systematically purchased from three types of retailers between May 2018 and March 2019. In total, 200 pork products were tested using a lysing agent to release the HEV from the product for detection. RT-PCR for HEV was performed on samples with an extraction efficiency >1 % (n = 188/200) (94 %). Low level HEV RNA was detected in 9/188 (4.8 %) pork products tested. The highest incidence of HEV RNA was in pork liver where 6/25 (24 %) samples were positive. The concentration of HEV ranged from 0.02 - to 9.4 genome copies/g of pork. Based on these data an exposure assessment was performed which found that if consumers followed advice from the Food Safety Authority of Ireland to achieve core temperatures of 70 °C or higher when cooking, the risk was likely to be negligible.

Whole genome sequencing of resistance and virulence genes in multi-drug resistant Pseudomonas aeruginosa.

BACKGROUND: Pseudomonas aeruginosa is an opportunistic bacterium that causes serious hospital-acquired infections. To assess the risk of clinically isolated P. aeruginosa to human health, we analyzed the resistance and virulence mechanisms of a collection of clinical isolates. METHODS: This was a retrospective study in which P. aeruginosa isolates collected from January 1, 2018 to August 31, 2019 were analyzed using phenotypic and whole-genome sequencing (WGS) methods. The analysis included 48 clinical samples. Median patient age was 54.0 (29.5) years, and 58.3% of patients were women. Data from the microbiology laboratory database were reviewed to identify P. aeruginosa isolates. All unique isolates available for further testing were included, and related clinical data were collected. Infections were defined as hospital acquired if the index culture was obtained at least 48 h after hospitalization. RESULTS: High-risk P. aeruginosa clones, including sequence types (STs) ST235 and ST111, were identified, in addition to 12 new STs. The isolates showed varying degrees of biofilm formation ability when evaluated at room temperature, along with reduced metabolic activity, as measured by metabolic staining, suggesting their ability to evade antimicrobial therapy. Most isolates (77.1%) were multidrug resistant (MDR), with the highest resistance and susceptibility rates to beta-lactams and colistimethate sodium, respectively. CONCLUSIONS: The MDR phenotypes of the examined isolates can be explained by the high prevalence of efflux-mediated resistance- and hydrolytic enzyme-encoding genes. These isolates had high cytotoxic potential, as indicated by the detection of toxin production-related genes.

Comprehensive Genomic Characterization of Cronobacter sakazakii Isolates from Infant Formula Processing Facilities Using Whole-Genome Sequencing.

Cronobacter sakazakii is an opportunistic pathogen linked to outbreaks in powdered infant formula (PIF), primarily causing meningitis and necrotizing enterocolitis. Whole-genome sequencing (WGS) was used to characterize 18 C. sakazakii strains isolated from PIF (powdered infant formula) manufacturing plants (2011-2015). Sequence Type (ST) 1 was identified as the dominant sequence type, and all isolates carried virulence genes for chemotaxis, flagellar motion, and heat shock proteins. Multiple antibiotic resistance genes were detected, with all isolates exhibiting resistance to Cephalosporins and Tetracycline. A significant correlation existed between genotypic and phenotypic antibiotic resistance. The plasmid Col(pHAD28) was identified in the isolates recovered from the same PIF environment. All isolates harbored at least one intact phage. All the study isolates were compared with a collection of 96 publicly available C. sakazakii genomes to place these isolates within a global context. This comprehensive study, integrating phylogenetic, genomic, and epidemiological data, contributes to a deeper understanding of Cronobacter outbreaks. It provides valuable insights to enhance surveillance, prevention, and control strategies in food processing and public health contexts.

Hybrid genome assemblies of four Shiga toxin-producing Escherichia coli strains containing a complete locus of enterocyte effacement and an O-Island 122.

This study describes the hybrid genome assemblies of four Shiga toxin-producing Escherichia coli strains isolated from the recto-anal junction of slaughter-age Irish sheep. In silico serotyping and genome analysis determined that each of the strains harbored a Shiga-toxin subtype, a complete locus of enterocyte effacement, and a rare O-island 122.

High-Soluble-Fiber Diet Attenuates Hypoxia-Induced Vascular Remodeling and the Development of Hypoxic Pulmonary Hypertension.

BACKGROUND: Hypoxic pulmonary hypertension is a difficult disease to manage that is characterized by sustained elevation of pulmonary vascular resistance and pulmonary artery pressure due to vasoconstriction, perivascular inflammation, and vascular remodeling. Consumption of soluble-fiber is associated with lower systemic blood pressure, but little is known about its ability to affect the pulmonary circulation. METHODS: Mice were fed either a low- or high-soluble-fiber diet (0% or 16.9% inulin) and then exposed to hypoxia (FiO2, 0.10) for 21 days to induce pulmonary hypertension. The impact of diet on right ventricular systolic pressure and pulmonary vascular resistance was determined in vivo or in ex vivo isolated lungs, respectively, and correlated with alterations in the composition of the gut microbiome, plasma metabolome, pulmonary inflammatory cell phenotype, and lung proteome. RESULTS: High-soluble-fiber diet increased the abundance of short-chain fatty acid-producing bacteria, with parallel increases in plasma propionate levels, and reduced the abundance of disease-related bacterial genera such as Staphylococcus, Clostridioides, and Streptococcus in hypoxic mice with parallel decreases in plasma levels of p-cresol sulfate. High-soluble-fiber diet decreased hypoxia-induced elevations of right ventricular systolic pressure and pulmonary vascular resistance. These changes were associated with reduced proportions of interstitial macrophages, dendritic cells, and nonclassical monocytes. Whole-lung proteomics revealed proteins and molecular pathways that may explain the effect of soluble-fiber supplementation. CONCLUSIONS: This study demonstrates for the first time that a high-soluble-fiber diet attenuates hypoxia-induced pulmonary vascular remodeling and the development of pulmonary hypertension in a mouse model of hypoxic pulmonary hypertension and highlights diet-derived metabolites that may have an immuno-modulatory role in the lung.

One size does not fit all - Trehalose metabolism by Clostridioides difficile is variable across the five phylogenetic lineages.

Clostridioides difficile, the leading cause of antibiotic-associated diarrhoea worldwide, is a genetically diverse species which can metabolise a number of nutrient sources upon colonising a dysbiotic gut environment. Trehalose, a disaccharide sugar consisting of two glucose molecules bonded by an α 1,1-glycosidic bond, has been hypothesised to be involved in the emergence of C. difficile hypervirulence due to its increased utilisation by the RT027 and RT078 strains. Here, growth in trehalose as the sole carbon source was shown to be non-uniform across representative C. difficile strains, even though the genes for its metabolism were induced. Growth in trehalose reduced the expression of genes associated with toxin production and sporulation in the C. difficile R20291 (RT027) and M120 (RT078) strains in vitro, suggesting an inhibitory effect on virulence factors. Interestingly, the R20291 TreR transcriptional regulatory protein appeared to possess an activator function as its DNA-binding ability was increased in the presence of its effector, trehalose-6-phosphate. Using RNA-sequencing analysis, we report the identification of a putative trehalose metabolism pathway which is induced during growth in trehalose: this has not been previously described within the C. difficile species. These data demonstrate the metabolic diversity exhibited by C. difficile which warrants further investigation to elucidate the molecular basis of trehalose metabolism within this important gut pathogen.

Validating the Utility of Multilocus Variable Number Tandem-repeat Analysis (MLVA) as a Subtyping Strategy to Monitor Listeria monocytogenes In-built Food Processing Environments.

Listeria monocytogenes is a serious human pathogen and an enduring challenge to control for the ready-to-eat food processing industry. Cost-effective tools that can be deployed by commercial or in-house laboratories to rapidly investigate and resolve contamination events in the built food processing environment are of value to the food industry. Multilocus variable number tandem-repeat analysis (MLVA) is a molecular subtyping method, which along with other same-generation methods such as pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) is being superseded in disease tracking and outbreak investigations by whole-genome sequencing (WGS). In this paper, it is demonstrated that MLVA can continue to play a valuable role as a valid, fast, simple, and cost-effective method to identify and track Listeria monocytogenes subtypes in factory environments, with the method being highly congruent with MLST. Although MLVA does not have the discriminatory power of WGS to identify truly persistent clones, with careful interpretation of results alongside isolate metadata, it remains a powerful tool in situations and locations where WGS may not be readily available to food business operators.

Detection of Hepatitis A RNA, Hepatitis E RNA, Human Adenovirus F DNA, and Norovirus RNA in Fresh and Frozen Berry Products at Point of Retail in Ireland.

Soft fruits are at particular risk of contamination with enteric viruses such as Hepatitis A virus (HAV), Hepatitis E Virus (HEV), Norovirus (NoV), Human Adenovirus (HAdV) and Sapovirus (SaV). The aim of this study was to investigate, for the first time, the presence of these biological agents in ready to eat (RTE) berries at point of retail in Ireland. A sampling strategy was designed in which RTE fresh and frozen strawberries and raspberries were purchased from five retailers between May and October 2018. Reverse Transcriptase Polymerase Chain Reaction (RT-qPCR) assays for HEV RNA, Nov RNA, SaV RNA, and human Adenovirus species F DNA (HAdV-F) were performed on 239 samples (25g portions). Viral nucleic acid was present in 6.7% (n = 16) of samples tested as follows: HAV RNA (n = 5), HAdV-F DNA (n = 5), HEV RNA (n = 3) and NoV GII RNA (n = 3). Sapovirus RNA was not detected in any product. No significant differences were found between berry type, fresh/frozen status, or supermarket source. This study suggests a risk that exists across all retail outlets however only low levels of nucleic acid ranging from 0 to 16 genome copies/g were present. Although these findings may reflect non-viable/non-infectious virus the continued provision of risk mitigation advice to consumers is warranted and further work is required to ensure control measures to reduce contamination are implemented and enforced.

Regulation of iron metabolism is critical for the survival of Salmonella Typhimurium in pasteurized milk.

Salmonella is known to survive in raw/pasteurized milk and cause foodborne outbreaks. Lactoferrin, present in milk from all animal sources, is an iron-binding glycoprotein that limits the availability of iron to pathogenic bacteria. Despite the presence of lactoferrins, Salmonella can grow in milk obtained from different animal sources. However, the mechanism by which Salmonella overcomes iron scarcity induced by lactoferrin in milk is not evaluated yet. Salmonella employs the DNA binding transcriptional regulator Fur (ferric update regulator) to mediate iron uptake during survival in iron deplete conditions. To understand the importance of Fur in Salmonella milk growth, we profiled the growth of Salmonella Typhimurium Δfur (ST4/74Δfur) in both bovine and camel milk. ST4/74Δfur was highly inhibited in milk compared to wild-type ST4/74, confirming the importance of Fur mediated regulation of iron metabolism in Salmonella milk growth. We further studied the biology of ST4/74Δfur to understand the importance of iron metabolism in Salmonella milk survival. Using increasing concentrations of FeCl3, and the antibiotic streptonigrin we show that iron accumulates in the cytoplasm of ST4/74Δfur. We hypothesized that the accumulated iron could activate oxidative stress via Fenton's reaction leading to growth inhibition. However, the inhibition of ST4/74Δfur in milk was not due to Fenton's reaction, but due to the 'iron scarce' conditions of milk and microaerophilic incubation conditions which made the presence of the fur gene indispensable for Salmonella milk growth. Subsequently, survival studies of 14 other transcriptional mutants of ST4/74 in milk confirmed that RpoE-mediated response to extracytoplasmic stress is also important for the survival of Salmonella in milk. Though we have data only for fur and rpoE, many other Salmonella transcriptional factors could play important roles in the growth of Salmonella in milk, a theme for future research on Salmonella milk biology. Nevertheless, our data provide early insights into the biology of milk-associated Salmonella.

Dynamic evolution and transmission of a blaNDM-1-bearing fusion plasmid in a clinical Escherichia coli.

Plasmids are the main driving forces for the rapid dissemination of blaNDM-1. In recent years, blaNDM-1-carrying fusion plasmids have been frequently reported. However, the evolutionary patterns of blaNDM-1-carrying fusion plasmids remain largely unknown. Herein, we reported a blaNDM-1-bearing fusion plasmid pZX35-269k possessing IncFII and IncA/C2 replicons from clinical ST349 E. coli 13ZX35. The backbone of pZX35-269k was structurally unstable, which was manifested in different types of structural dissociation during conjugation and passage, thereby forming various daughter plasmids. Moreover, the same events were observed in the clinical setting as well. We found that pZX35-269k exhibited highly identical to two plasmids (pZX30-70k and pZX30-192k) in 13ZX30, both of which were isolated from the same hospital. Sequence analysis highlighted that two plasmids in 13ZX30 evolved from pZX35-269k through homologous recombination of a 4856-bp fragment. Collectively, this study confirmed the transmission and structural evolution of a blaNDM-1-bearing fusion plasmid in both laboratory and clinical settings, and provided clear evidence of plasmid spread and evolution in clinical settings. Such versatile plasmids may represent a potential risk for the public health.

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.

Cronobacter Species in the Built Food Production Environment: A Review on Persistence, Pathogenicity, Regulation and Detection Methods.

The powdered formula market is large and growing, with sales and manufacturing increasing by 120% between 2012 and 2021. With this growing market, there must come an increasing emphasis on maintaining a high standard of hygiene to ensure a safe product. In particular, Cronobacter species pose a risk to public health through their potential to cause severe illness in susceptible infants who consume contaminated powdered infant formula (PIF). Assessment of this risk is dependent on determining prevalence in PIF-producing factories, which can be challenging to measure with the heterogeneity observed in the design of built process facilities. There is also a potential risk of bacterial growth occurring during rehydration, given the observed persistence of Cronobacter in desiccated conditions. In addition, novel detection methods are emerging to effectively track and monitor Cronobacter species across the food chain. This review will explore the different vehicles that lead to Cronobacter species' environmental persistence in the food production environment, as well as their pathogenicity, detection methods and the regulatory framework surrounding PIF manufacturing that ensures a safe product for the global consumer.

Dissemination of carbapenemase-producing Enterobacteriaceae and associated resistance determinants through global food systems.

Antimicrobial agents are a critical component of modern healthcare systems, fulfilling a core function in patient care and improving individual patient outcomes and consequently overall public health. However, the efficacy of antimicrobial interventions is being consistently eroded by the emergence and dissemination of various antimicrobial resistance (AMR) mechanisms. One highly valued class of antimicrobial compounds is carbapenems, which retain efficacy in treating most multidrug-resistant infections and are considered "last line" agents. Therefore, recent trends in proliferation of carbapenem resistance (CR) via dissemination of carbapenemase-encoding genes among members of the Enterobacteriaceae family pose a significant threat to public health. While much of the focus relating to this has been on nosocomial environments, community-acquired carbapenemase-producing Enterobacteriaceae (CPE) infections and their associated transmission routes are less well studied. Among these community-associated vectors, the role of food chains and contaminated foods is important, since Enterobacteriaceae occupy niches within these settings. This review examines foodborne CPE transmission by exploring how interactions within and between food, the food chain, and agriculture not only promote and disseminate CPE, but also create reservoirs of mobile genetic elements that may lead to further carbapenemase gene proliferation both within and between microbial communities. Additionally, recent developments regarding the global occurrence and molecular epidemiology of CPEs in food chains will be reviewed.

Insertion sequences mediate clinical ST34 monophasic Salmonella enterica serovar Typhimurium plasmid polymorphism.

Hybrid plasmids can combine the genetic elements of multiple plasmids, with the potential to carry a variety of antibiotic resistance genes and virulence genes, causing a great public health concern. Hybrid plasmids formed by fusion events may further exacerbate the spread of antibiotic resistance genes as well as plasmid evolution. Salmonella enterica serovar 4,[5],12:i:- is a monophasic variant of S. Typhimurium, which is one of the major causes of foodborne disease outbreaks worldwide. To assess the risk of transmission due to plasmid structure changes, we investigated the structural diversity of plasmids in two S. 4,[5],12:i:- isolates. Nanopore long-read sequencing was performed for plasmid comparison between original plasmids (donor isolates) and reorganized plasmids. We found that the IncHI2-IncHI2A multidrug resistance (MDR) plasmids in S. 4,[5],12:i:- possessed high plasticity, and could undergo recombination with other plasmids to form fusion plasmids of different sizes. Plasmid structural polymorphisms were mainly mediated by insertion sequences such as IS26 and ISPa40, and led to the rearrangement of the plasmid internal structures. To the best of our knowledge, this is the first report of the fusion of the IncHI2-IncHI2A and IncB/O/K/Z plasmids in S. 4,[5],12:i:- mediated by IS26. In addition, we also found that the mcr-1 gene was able to generate duplication during conjugation. Polymorphic changes in MDR plasmids during conjugation may further reduce the choice of clinical therapeutic agents. Therefore, continuous monitoring regarding plasmid polymorphic changes during transmission in both in vitro and in vivo is urgently needed to decipher the MDR plasmid evolution.

The Endometrial Microbiota-16S rRNA Gene Sequence Signatures in Healthy, Pregnant and Endometritis Dairy Cows.

Endometritis is one of the most important causes of infertility in dairy cows, resulting in high economic losses in the dairy industry. Though the presence of a commensal uterine microbiota is now well established, the complex role of these bacteria in genital health, fertility, and susceptibility to uterine diseases remains unclear. In this study, we explore the endometrial microbiota through 16S rRNA gene profiling from cytobrush samples taken ex vivo from healthy, pregnant, and endometritis cows. There were no significant differences between healthy and pregnant cows, whose uterine microbiota were dominated by Streptococcus, Pseudomonas, Fusobacterium, Lactococcus and Bacteroides. Compared to pregnant and clinically healthy cows, the uterine bacterial community of endometritis cows was significantly decreased in species diversity (p < 0.05), reflecting uneven community composition in different patterns with either dominance of Escherichia-Shigella, Histophilus, Bacteroides and Porphyromonas or Actinobacteria.

The effect of cold storage and cooking on the viability of Clostridioides difficile spores in consumer foods.

The increased detection of clinical cases of Clostridioides difficile coupled with the persistence of clostridial spores at various stages along the food chain suggest that this pathogen may be foodborne. This study examined C. difficile (ribotypes 078 and 126) spore viability in chicken breast, beef steak, spinach leaves and cottage cheese during refrigerated (4 °C) and frozen (-20 °C) storage with and without a subsequent sous vide mild cooking (60 °C, 1 h). Spore inactivation at 80 °C in phosphate buffer solution, beef and chicken were also investigated to provide D80°C values and determine if PBS was a suitable model system for real food matrices. There was no decrease in spore concentration after chilled or frozen storage and/or sous vide cooking at 60 °C. Non-log-linear thermal inactivation was observed for both C. difficile ribotypes at 80 °C in phosphate buffer solution (PBS), beef and chicken. The predicted PBS D80°C values of 5.72±[2.90, 8.55] min and 7.50±[6.61, 8.39] min for RT078 and RT126, respectively, were in agreement with the food matrices D80°C values of 5.65 min (95% CI range from 4.29 to 8.89 min) for RT078 and 7.35 min (95% CI range from 6.81 to 7.01 min) for RT126. It was concluded that C. difficile spores survive chilled and frozen storage and mild cooking at 60 °C but may be inactivated at 80 °C. Moreover thermal inactivation in PBS was representative of that observed in real food matrices (beef and chicken).

Terrisporobacter hibernicus sp. nov., isolated from bovine faeces in Northern Ireland.

A new species of Terrisporobacter, a Gram-positive, spore-forming anaerobic group, proposed name Terrisporobacter hibernicus sp. nov., was isolated in Northern Ireland from bovine faeces collected in 2016. Designated as MCA3T, cells of T. hibernicus sp. nov. are rod shaped and motile. Cells tolerate NaCl from 0.5 to 5.5 % (w/v), with a pH tolerance between pH 6 and 9. The optimal temperature for growth is 35-40 °C, and temperatures from 20 to 30 °C are tolerated. The polar lipid profile displays diphosphatidylglycerol, phosphatidylglycerol, two aminoglycolipids, one glycophospholipid, one aminolipid, three glycolipids, five phospholipids and one lipid. No respiratory quinones are detected. The predominant fatty acid profile includes C16 : 0 at 22.8 %. Strain MCA3T is positive for glucose and maltose acidification, as well as glycerol and sorbitol. The biochemical results from a VITEK2 assay of strain MCA3T, Terrisporobacter petrolearius LAM0A37T and Terrisporobacter mayombei DSM 6539T are also included for the first time. The closed and complete genome of strain MCA3T from a hybrid Oxford Nanopore Technology MinION/Illumina assembly reveals no evidence for known virulence genes. Draft genome sequencing of T. mayombei DSM 6539T and T. petrolearius LAM0A37T, as performed by Illumina MiSeq, provides reference genomes for these respective species of Terrisporobacter for the first time. DNA-DNA hybridization values (d4) of MCA3T to Terrisporobacter glycolicus ATCC 14880T, T. petrolearius LAM0A37T and T. mayombei DSM 6539T are 48.8, 67.4 and 46.3 %, with cutoff value at 70 %. The type strain for T. hibernicus sp. nov. is MCA3T (=NCTC 14625T=LMG 32430T).

Clostridioides difficile as a Potential Pathogen of Importance to One Health: A Review.

Clostridioides difficile (basonym Clostridium) is a bacterial enteropathogen associated with cases of C. difficile infection that can result in pseudomembranous colitis, rapid fluid loss, and death. For decades following its isolation, C. difficile was thought to be a solely nosocomial pathogen, being isolated from individuals undergoing antimicrobial therapy and largely affecting elderly populations. More recently, C. difficile spores have been identified in the broader environment, including in food-producing animals, soil, and food matrices, in both ready-to-eat foods and meat products. Furthermore, evidence has emerged of hypervirulent ribotypes (RTs), such as RT078, similar to those cultured in asymptomatic carriers, also being identified in these environments. This finding may reflect on adaptations arising in these bacteria following selection pressures encountered in these niches, and which occurs due to an increase in antimicrobial usage in both clinical and veterinary settings. As C. difficile continues to adapt to new ecological niches, the taxonomy of this genus has also been evolving. To help understand the transmission and virulence potential of these bacteria of importance to veterinary public health, strategies applying multi-omics-based technologies may prove useful. These approaches may extend our current understanding of this recognized nosocomial pathogen, perhaps redefining it as a zoonotic bacterium. In this review, a brief background on the epidemiological presentation of C. difficile will be highlighted, followed by a review of C. difficile in food-producing animals and food products. The current state of C. difficile taxonomy will provide evidence of Clade 5 (ST11/RT078) delineation, as well as background on the genomic elements linked to C. difficile virulence and ongoing speciation. Recent studies applying second- and third-generation sequencing technologies will be highlighted, and which will further strengthen the argument made by many throughout the world regarding this pathogen and its consideration within a One Health dimension.