Clindamycin-resistant clone of Clostridium difficile PCR Ribotype 027, Europe

Assessing the Feasibility of Employing a Combination of a Bacteriophage-Derived Endolysin and Spore Germinants to Treat Relapsing Clostridioides difficile Infection

Clostridioides difficile is a Gram-positive, anaerobic, spore-forming bacillus and is a major cause of healthcare-associated infections. Whereas the vegetative form of the pathogen is susceptible to treatment with antibiotics, its ability to persist in the gut as antibiotic-resistant spores means that reinfection can occur in cases were the individual fails to re-establish a protective microflora. Bacteriophages and their lysins are currently being explored as treatment options due to their specificity, which minimizes the disruption to the other members of the gut microflora that are protective. The feasibility of employing recombinant endolysins to target the vegetative form of C. difficile has been demonstrated in animal models. In this study, we cloned and expressed the enzyme active domain of LysCD6356 and confirmed its ability to lyse the vegetative forms of a diverse range of clinical isolates of C. difficile, which included members of the hypervirulent 027 ribotype. Lytic activity was adversely affected by calcium, which is naturally found in the gut and is released from the spore upon germination. Our results suggests that a strategy in which the triggering of spore germination is separated in time from the application of the lysin could be developed as a strategy to reduce the risk of relapsing C. difficile infections.

High-Level Resistance of Toxigenic Clostridioides difficile Genotype to Macrolide-Lincosamide- Streptogramin B in Community Acquired Patients in Eastern China

Background

Clostridioides difficile resistant to macrolide-lincosamide-streptogramin B (MLS_B) has not been reported in China.

Methods

In a cross-sectional study in two tertiary hospitals, C. difficile isolates from stool specimens from community-onset, hospital-associated diarrheal patients were analyzed for toxin genes, genotype, and antibiotic resistance, and the patients’ clinical charts were reviewed.

Results

A total of 190 (15.2%) isolates (102 A⁺B⁺ and 88 A⁻B⁺) from 1250 community acquired (CA) patients were recovered and all were susceptible to vancomycin and metronidazole. High-level resistance (minimum inhibitory concentration > 128 mg/L) to erythromycin and clindamycin was recorded in 77.9% and 88.4% of the tested isolates, respectively. Furthermore, 89.3% (159/178) of the isolates resistant to MLS_B carried the erythromycin resistance methylase gene (ermB). The statistically significant factors associated with C. difficile infection (CDI) induced by A⁻B⁺ isolates with MLS_B resistance included a severity score of >2 (odds ratio [95% confidence interval], 7.43 [2.31–23.87]) and platelet count (cells × 10⁹ cells/L) < 100 [5.19 (1.58–17.04)]. The proportion of A⁻B⁺ increased with enhanced CDI severity (x² = 21.62, P < 0.001), which was significantly higher than that of ermB-positive A⁺B⁺ in severity score of 4 (x² = 8.61, P = 0.003). The average severity score of ermB-positive isolates was significantly higher than that of ermB-negative isolates in A⁻B⁺ (Z = −2.41, P = 0.016).

Conclusion

The ermB-positive A⁻B⁺C. difficile with MLS_B resistance is described for the first time as a potential epidemic clone inducing severe CDI in CA diarrheal patients in Eastern China.

A global to local genomics analysis of Clostridioides difficile ST1/RT027 identifies cryptic transmission events in a northern Arizona healthcare network

Clostridioides difficile is a ubiquitous, diarrhoeagenic pathogen often associated with healthcare-acquired infections that can cause a range of symptoms from mild, self-limiting disease to toxic megacolon and death. Since the early 2000s, a large proportion of C. difficile cases have been attributed to the ribotype 027 (RT027) lineage, which is associated with sequence type 1 (ST1) in the C. difficile multilocus sequence typing scheme. The spread of ST1 has been attributed, in part, to resistance to fluoroquinolones used to treat unrelated infections, which creates conditions ideal for C. difficile colonization and proliferation. In this study, we analysed 27 isolates from a healthcare network in northern Arizona, USA, and 1352 publicly available ST1 genomes to place locally sampled isolates into a global context. Whole genome, single nucleotide polymorphism analysis demonstrated that at least six separate introductions of ST1 were observed in healthcare facilities in northern Arizona over an 18-month sampling period. A reconstruction of transmission networks identified potential nosocomial transmission of isolates, which were only identified via whole genome sequence analysis. Antibiotic resistance heterogeneity was observed among ST1 genomes, including variability in resistance profiles among locally sampled ST1 isolates. To investigate why ST1 genomes are so common globally and in northern Arizona, we compared all high-quality C. difficile genomes and identified that ST1 genomes have gained and lost a number of genomic regions compared to all other C. difficile genomes; analyses of other toxigenic C. difficile sequence types demonstrate that this loss may be anomalous and could be related to niche specialization. These results suggest that a combination of antimicrobial resistance and gain and loss of specific genes may explain the prominent association of this sequence type with C. difficile infection cases worldwide. The degree of genetic variability in ST1 suggests that classifying all ST1 genomes into a quinolone-resistant hypervirulent clone category may not be appropriate. Whole genome sequencing of clinical C. difficile isolates provides a high-resolution surveillance strategy for monitoring persistence and transmission of C. difficile and for assessing the performance of infection prevention and control strategies.

Occurrence of Clostridium difficile ribotype 027 in hospitals of Silesia, Poland

Clostridium difficile is an important healthcare-associated pathogen, responsible for a broad spectrum of diarrheal diseases. The aim of this prospective study was to determine the occurrence of C. difficile infection (CDI), to characterize cultured C. difficile strains and to investigate the association of fecal lactoferrin with CDI. Between January 2013 and June 2014, 148 stool samples were obtained from adult diarrheal patients (C. difficile as a suspected pathogen) hospitalized in different healthcare facilities of 15 Silesian hospitals. Out of 134 isolated C. difficile strains, 108 were ribotyped: 82.4% belonged to Type 027, 2.8% to Type 176, 2.8% to Type 014, 1.9% to Type 010 and 0.9% to Types 001, 018, 020 and 046 each. In total, 6.5% non-typable strains were identified. All Type 027 isolates contained both toxin genes tcdA & tcdB, and binary toxin genes (cdtA &cdtB). Susceptibility testing revealed that all Type 027 isolates were sensitive to metronidazole and vancomycin and resistant to moxifloxacin, ciprofloxacin, imipenem and erythromycin. Of 89 Type 027 strains, 16 had a ermB (688 bp) gene coinciding with high levels of erythromycin resistance (MIC >256 μg/mL). Of 16 ermB positive strains, 14 demonstrated also high level of resistance to clindamycin (>256 μg/mL). A significant difference (p = 0.004) in lactoferrin level was found between C. difficile toxin-positive (n = 123; median 185.9 μg/mL; IQR 238.8) and toxin-negative (n = 25; median 22.4 μg/mL; IQR 141.7) fecal samples. Stool samples from n = 89 patients with CDI caused by Type 027 demonstrated significantly higher (p = 0.03) lactoferrin level (median 173.0 μg/mL; IQR 237.3) than from patients with CDI caused by other ribotypes and non-typable C. difficile strains (median 189.4 μg/mL; IQR 190.8).

Comparative Genome Analysis and Global Phylogeny of the Toxin Variant Clostridium difficile PCR Ribotype 017 Reveals the Evolution of Two Independent Sublineages

The diarrheal pathogen Clostridium difficile consists of at least six distinct evolutionary lineages. The RT017 lineage is anomalous, as strains only express toxin B, compared to strains from other lineages that produce toxins A and B and, occasionally, binary toxin. Historically, RT017 initially was reported in Asia but now has been reported worldwide. We used whole-genome sequencing and phylogenetic analysis to investigate the patterns of global spread and population structure of 277 RT017 isolates from animal and human origins from six continents, isolated between 1990 and 2013. We reveal two distinct evenly split sublineages (SL1 and SL2) of C. difficile RT017 that contain multiple independent clonal expansions. All 24 animal isolates were contained within SL1 along with human isolates, suggesting potential transmission between animals and humans. Genetic analyses revealed an overrepresentation of antibiotic resistance genes. Phylogeographic analyses show a North American origin for RT017, as has been found for the recently emerged epidemic RT027 lineage. Despite having only one toxin, RT017 strains have evolved in parallel from at least two independent sources and can readily transmit between continents.

Subtyping and antimicrobial susceptibility of Clostridium difficile PCR ribotype 078/126 isolates of human and animal origin

The Clostridium difficile PCR ribotype complex 078/126 (RT078/126) is often involved in human disease and is also frequently isolated from diverse animal species. The high genetic relatedness between human and animal RT078/126 isolates found in different regions has encouraged discussion about the zoonotic potential of this lineage. We compared for the first time the genetic diversity and antimicrobial susceptibility profiles of human and animal C. difficile RT078/126 isolates from Spain. A collection of 96 isolates (50 of human and 46 of animal origin; 63 and 33 of ribotypes 078 and 126, respectively) was subtyped by an improved amplified fragment length polymorphism (AFLP) fingerprinting method and tested for in vitro antimicrobial susceptibility. A total of 67 genotypes were distinguished, three of which grouped together isolates of human and animal origin. Furthermore, two main groups of isolates that mostly correlated with PCR ribotypes could be distinguished in the AFLP dendrogram. Human origin was significantly associated with resistance to ertapenem, erythromycin and moxifloxacin; resistance to clindamycin and erythromycin was associated with RT126 and AFLP group 1. Twenty-nine isolates (30.2% of total) displayed heteroresistance to metronidazole. Substantial differences were observed in the susceptibility profiles of isolates belonging to a same genotype. Altogether, these results provide a valuable baseline for future studies on the epidemiology of C. difficile RT078/126.

Comparison of antimicrobial susceptibility among Clostridium difficile isolated from an integrated human and swine population in Texas

Clostridium difficile can be a major problem in hospitals because the bacterium primarily affects individuals with an altered intestinal flora; this largely occurs through prolonged antibiotic use. Proposed sources of increased community-acquired infections are food animals and retail meats. The objective of this study was to compare the antimicrobial resistance patterns of C. difficile isolated from a closed, integrated population of humans and swine to increase understanding of the bacterium in these populations. Swine fecal samples were collected from a vertically flowing swine population consisting of farrowing, nursery, breeding, and grower/finisher production groups. Human wastewater samples were collected from swine worker and nonworker occupational group cohorts. Antimicrobial susceptibility testing was performed on 523 C. difficile strains from the population using the commercially available agar diffusion Epsilometer test (Etest(®)) for 11 different antimicrobials. All of the swine and human strains were susceptible to amoxicillin/clavulanic acid, piperacillin/tazobactam, and vancomycin. In addition, all of the human strains were susceptible to chloramphenicol. The majority of the human and swine strains were resistant to cefoxitin and ciprofloxacin. Statistically significant differences in antimicrobial susceptibility were found among the swine production groups for ciprofloxacin, tetracycline, amoxicillin/clavulanic acid, and clindamycin. No significant differences in antimicrobial susceptibility were found across human occupational group cohorts. We found that 8.3% of the swine strains and 13.3% of the human strains exhibited resistance to metronidazole. The finding of differences in susceptibility patterns between human and swine strains of C. difficile provides evidence that transmission between host species in this integrated population is unlikely.

Evaluation of automated repetitive-sequence-based PCR (DiversiLab) compared to PCR ribotyping for rapid molecular typing of community- and nosocomial-acquired Clostridium difficile

Automated repetitive PCR (rep-PCR; DiversiLab) was compared to PCR ribotyping of the 16S-23S RNA intergenic spacer of Clostridium difficile (CD) as the "gold standard" method for CD typing. PCR products were separated on DiversiLab LabChips (bioMérieux, St. Laurent, Quebec, Canada) utilizing a 2100 Bioanalyzer (Agilent Technologies, Santa Clara, CA) operating the DiversiLab v1.4 assay. Bioanalyzer data were exported to a secure DiversiLab website and analyzed with DiversiLab v3.4 software. Replicability of each method was verified by confirming that the 5 CD reference strains (RS) formed distinct clusters (CD4, CD6, VL0047, VL0013 [ribotype 027], VL0018 [ribotype 001]) by both typing methods. Ninety randomly selected clinical isolates (CS) were analyzed by both methods: 49 from community-acquired and 41 from hospital-acquired cases. A similarity index (SI) of ≥90% was used to define clusters when comparing the known RS cluster to the PCR ribotyping and rep-PCR patterns of CS. Fourteen different PCR-ribotype clusters were identified, but most CS formed 4 major clusters (i.e., CD4 [15/90; 17%], CD6 [17%], 027 [12%], and 001 [9%]). A total of 7 rep-PCR types were identified, but most CS formed 2 major rep-PCR clusters (i.e., CD4 [29/90; 32%] and CD6 [23%]); several PCR ribotypes occurred within a single rep-PCR cluster. Rep-PCR did not distinguish 027 or 001 isolates; i) 027 RS strain did not cluster, ii) eleven 027 CS strains clustered as CD4, iii) no 027 CS strains clustered with the 027 RS, and iv) only 2 001 CS clustered with the RS. Agreement between the PCR-ribotype and rep-PCR clusters only occurred for 35/90 (39%) of the CS using a rep-PCR SI of ≥90%. Rep-PCR time to results was similar, but the annual costs of routinely using this method are 32% higher than PCR ribotyping. Routine use of rep-PCR for CD typing is limited by its lack of definitive separation of the hypertoxigenic 027 or 001 outbreak CD strains.

Multidrug resistance in European Clostridium difficile clinical isolates

OBJECTIVES

Multidrug resistance and antibiotic resistance mechanisms were investigated in 316 Clostridium difficile clinical isolates collected during the first European surveillance on C. difficile in 2005.

METHODS

MICs of eight different antibiotics were determined using Etest. Reserpine- and carbonyl cyanide m-chlorophenylhydrazone-sensitive efflux was tested using the agar dilution method. Molecular analysis of the resistance mechanisms was performed using PCR assays, PCR mapping and sequencing.

RESULTS

One hundred and forty-eight C. difficile strains were resistant to at least one antibiotic and 82 (55%) were multidrug resistant. In particular, 48% of these isolates were resistant to erythromycin, clindamycin, moxifloxacin and rifampicin. New genetic elements or determinants conferring resistance to erythromycin/clindamycin or tetracycline were identified. Even if most multiresistant strains carried an erm(B) gene, quite a few were erm(B) negative. In-depth analysis of the underlying mechanism in these isolates was carried out, including analysis of 23S rDNA and the ribosomal proteins L4 and L22. Interestingly, resistance to rifampicin was observed in multidrug-resistant strains in association with resistance to fluoroquinolones. Mutations in the rpo(B) and gyrA genes were identified as the cause of resistance to these antibiotics, respectively.

CONCLUSIONS

Characterization of multidrug-resistant C. difficile clinical isolates shows that antibiotic resistance is changing, involving new determinants and mechanisms and providing this pathogen with potential advantages over the co-resident gut flora. The present paper provides, for the first time, a comprehensive picture of the different characteristics of multidrug-resistant C. difficile strains in Europe in 2005 and represents an important source of data for future comparative European studies.

An investigation of the subtype diversity of clinical isolates of Irish Clostridium difficile ribotypes 027 and 078 by repetitive-extragenic palindromic PCR

A repetitive-extragenic palindromic PCR (rep-PCR) subtyping method (DiversiLab) in conjunction with ribotyping, toxinotyping and antimicrobial-susceptibility testing was used to detect subtypes within Clostridium difficile ribotypes 027 and 078. Clinical isolates of ribotypes 027 (toxinotype III) (n = 30) and 078 (toxinotype V) (n = 23) were provided by health-care facilities across the Republic of Ireland over 2 months in 2006 and 1 month in 2009. Ribotype 027 isolates were significantly more related to each other (9 different subtype profiles) when compared to ribotype 078 isolates (14 different profiles) (P = 0.001; cut-off >90 % similarity). Almost half of ribotype 078 isolates (45.5 %) showed no relationship to each other. The clonality of ribotype 027 isolates suggests effective adaptation to the human niche, whereas the considerable genetic diversity within ribotype 078 isolates suggests that they may have originated from a variety of sources. Subtyping correlated well with antimicrobial susceptibility, in particular clindamycin susceptibility for ribotype 027, but diverse antimicrobial-susceptibility profiles were seen in ribotype 078 isolates, even within a single health-care facility. Between 2006 and 2009, a change in the predominant subtype of ribotype 027 was seen, with the recent clone representing half of all ribotype 027 isolates studied. This strain exhibited 89 % similarity to a rep-PCR profile of the North American NAP-1 strain.

The epidemiology of Clostridium difficile in Scotland

The objective of this study was to characterise the epidemiology of Clostridium difficile in Scotland by determining the distribution of PCR ribotypes and antimicrobial susceptibility in 1613 isolates collected from all healthboard areas of Scotland in the period November 2007-December 2009. Three PCR ribotypes predominated amongst the Scottish isolates of C. difficile; ribotype 106 (29.4%), ribotype 001 (22%) and ribotype 027 (12.6%) followed by the less prevalent ribotypes including 002, 015, 014, 078, 005, 023 and 020. The distribution of ribotypes varied between healthboard areas. Ribotype 106 or 001 was the predominant ribotype in 10 healthboard areas, while ribotype 027 was the predominant type in two neighbouring areas. Antimicrobial susceptibility testing of C. difficile isolates showed high frequencies of resistance to moxifloxacin, levofloxacin, erythromycin and cefotaxime in the epidemic C. difficile ribotypes 001, 027 and 106 compared to other less common ribotypes. Furthermore, reduced susceptibility to metronidazole was found only in the epidemic strains. These findings are compatible with the hypothesis that fluoroquinolones, macrolides and cephalosporins may play a role in the spread of C. difficile in Scotland (while the role of metronidazole needs further investigations), and highlights the role of antimicrobial stewardship in preventing and controlling C. difficile infection (CDI).

The changing epidemiology of Clostridium difficile infections

The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

The changing epidemiology of Clostridium difficile infections

The epidemiology of Clostridium difficile infection (CDI) has changed dramatically during this millennium. Infection rates have increased markedly in most countries with detailed surveillance data. There have been clear changes in the clinical presentation, response to treatment, and outcome of CDI. These changes have been driven to a major degree by the emergence and epidemic spread of a novel strain, known as PCR ribotype 027 (sometimes referred to as BI/NAP1/027). We review the evidence for the changing epidemiology, clinical virulence and outcome of treatment of CDI, and the similarities and differences between data from various countries and continents. Community-acquired CDI has also emerged, although the evidence for this as a distinct new entity is less clear. There are new data on the etiology of and potential risk factors for CDI; controversial issues include specific antimicrobial agents, gastric acid suppressants, potential animal and food sources of C. difficile, and the effect of the use of alcohol-based hand hygiene agents.

Clostridium difficile PCR ribotype 027: assessing the risks of further worldwide spread

Highly virulent strains of Clostridium difficile have emerged since 2003, causing large outbreaks of severe, often fatal, colitis in North America and Europe. In 2008–10, virulent strains spread between continents, with the first reported cases of fluoroquinolone-resistant C difficile PCR ribotype 027 in three Asia-Pacific countries and Central America. We present a risk assessment framework for assessing risks of further worldwide spread of this pathogen. This framework first requires identification of potential vehicles of introduction, including international transfers of hospital patients, international tourism and migration, and trade in livestock, associated commodities, and foodstuffs. It then calls for assessment of the risks of pathogen release, of exposure of individuals if release happens, and of resulting outbreaks. Health departments in countries unaffected by outbreaks should assess the risk of introduction or reintroduction of C difficile PCR ribotype 027 using a structured risk-assessment approach.

Coexistence of multiple multilocus variable-number tandem-repeat analysis subtypes of Clostridium difficile PCR ribotype 027 strains within fecal specimens

We investigated whether multilocus variable-number tandem-repeat analysis (MLVA) typing could identify different subtypes of Clostridium difficile ribotype 027 within the same feces specimen. Five of 39 specimens yielded at least one isolate with an MLVA profile different (more than five summed tandem repeat differences) from that of other isolates in the same specimen, thereby potentially obscuring epidemiological links between C. difficile infection cases.

Clostridium difficile infection caused by the epidemic BI/NAP1/027 strain

Rates and severity of Clostridium difficile infection (CDI) in hospitals in North America and Europe have increased since 2000 and correlate with dissemination of an epidemic strain characterized by higher than usual toxin A and B production, the presence of a third toxin, binary toxin, and high-level resistance to fluoroquinolone antibiotics. The strain, which is restriction endonuclease analysis group BI, pulse-field gel electrophoresis type NAP1, and polymerase chain reaction ribotype 027, is designated BI/NAP1/027. How this strain has become so widely distributed geographically and produces such severe CDI is the subject of active investigation. The deletion at position 117 of the tcdC gene, a repressor of toxin A and B production, is one possible contributor to increased levels of the toxins. The role of binary toxin is unknown. Recent isolates of BI/NAP1/027 were found to be resistant to fluoroquinolones, which is likely to contribute to the dissemination of this strain. Other virulence factors such as increased sporulation and surface layer protein adherence are also under investigation. Infections caused by this organism are particularly frequent among elderly hospitalized patients, in whom the attributable 30-day mortality is greater than 5%. Major risk factors for BI/NAP1/027 infection include advanced age, hospitalization, and exposure to specific antimicrobials, especially fluoroquinolones and cephalosporins. When CDI is severe, vancomycin treatment is more effective than metronidazole; for mild disease either agent can be used. Control of hospital outbreaks caused by BI/NAP1/027 is difficult but possible through a combination of barrier precautions, environmental cleaning, and antimicrobial stewardship.

Comparison of molecular typing methods applied to Clostridium difficile

Since the 1980s the epidemiology of Clostridium difficile infection (CDI) has been investigated by the application of many different typing or fingerprinting methods. To study the epidemiology of CDI, a typing method with a high discriminatory power, typeability, and reproducibility is required. Molecular typing methods are generally regarded as having advantages over phenotypic methods in terms of the stability of genomic markers and providing greater levels of typeability. A growing number of molecular methods have been applied to C. difficile. For the early and rapid detection of outbreak situations, methods such as restriction enzyme analysis, arbitrary primed polymerase chain reaction (PCR), and PCR ribotyping are commonly used. For long-term epidemiology, multilocus sequence typing, multilocus variable number of tandem repeats analysis, and amplified fragment length polymorphism are of interest. Currently, the PCR-ribotyping method and the library of PCR ribotypes in Cardiff are the benchmarks to which most typing studies around the world are compared. Multilocus variable number of tandem repeats analysis is the most discriminative typing method and will contribute significantly to our understanding of the epidemiology of this important nosocomial pathogen.

Emergence of Clostridium difficile infection due to a new hypervirulent strain, polymerase chain reaction ribotype 078

BACKGROUND

Since 2005, an increase in the prevalence of Clostridium difficile infection (CDI) due to polymerase chain reaction ribotype 078 has been noticed in The Netherlands. This strain has also been identified as the predominant strain in pigs and calves.

METHODS

CDI caused by type 078 was studied in relation to CDI caused by the hypervirulent type 027 and by types other than 027 and 078. Human and porcine isolates were further investigated and characterized by multilocus variable number tandem repeat analysis.

RESULTS

From February 2005 through February 2008, the incidence of type 078 among isolates obtained from 1687 patients increased from 3% to 13%. Compared with patients infected with type 027, patients infected with type 078 were younger (67.4 vs. 73.5 years; P < .01) and more frequently had community-associated disease (17.5% vs. 6.7%; odds ratio, 2.98; 95% confidence interval, 2.11-8.02); rates of severe diarrhea (38.9% vs. 40.0%) and attributable mortality (3.8% vs. 4.0%) were similar in both groups. Compared with patients infected with other types, patients infected with type 078 more frequently received fluoroquinolone therapy (29.4% vs. 19.8%; odds ratio, 2.17; 95% confidence interval, 1.06-4.44). Type 078 isolates contained genes for toxin A, toxin B, binary toxin, and a 39-base pair deletion in toxin regulator gene (tcdC), as well as a point mutation at position 184, resulting in a stop codon. Multilocus variable number tandem repeat analysis of 54 human and 11 porcine isolates revealed 4 clonal complexes containing both porcine and human isolates.

CONCLUSIONS

CDI due to type 078 and CDI due to type 027 present with similar severity, but CDI due to type 078 affects a younger population and is more frequently community associated. C. difficile type 078 isolates from humans and pigs are highly genetically related.