Characterisation and Carriage Ratio of Clostridium difficile Strains Isolated from a Community-Dwelling Elderly Population in the United Kingdom
Open Access
- 23 August 2011
- journal article
- research article
- Published by Public Library of Science (PLoS) in PLOS ONE
- Vol. 6 (8), e22804
- https://doi.org/10.1371/journal.pone.0022804
Abstract
Community-associated Clostridium difficile infection (CDI) appears to be an increasing problem. Reported carriage rates by C.difficile are debatable with suggestions that primary asymptomatic carriage is associated with decreased risk of subsequent diarrhoea. However, knowledge of potential reservoirs and intestinal carriage rates in the community, particularly in the elderly, the most susceptible group, is limited. We have determined the presence of C.difficile in the faeces of a healthy elderly cohort living outside of long-term care facilities (LCFs) in the United Kingdom. Faecal samples from 149 community-based healthy elderly volunteers (median age 81 years) were screened for C.difficile using direct (Brazier's CCEY) and enrichment (Cooked Meat broth) culture methods and a glutamate dehydrogenase (GDH) immunoassay. Isolates were PCR-ribotyped and analysed for toxin production and the presence of toxin genes. Of 149 faecal samples submitted, six (4%) were found to contain C.difficile. One particular sample was positive by both the GDH immunoassay and direct culture, and concurrently produced two distinct strain types: one toxigenic and the other non-toxigenic. The other five samples were only positive by enrichment culture method. Overall, four C.difficile isolates were non-toxigenic (PCR-ribotypes 009, 026 (n = 2) and 039), while three were toxigenic (PCR-ribotypes 003, 005 and 106). All individuals who had a positive culture were symptom-free and none of them had a history of CDI and/or antibiotics use in the 3 month period preceding recruitment. To our knowledge, this is the first study of the presence of C.difficile in healthy elderly community-dwelling individuals residing outside of LCFs. The observed carriage rate is lower than that reported for individuals in LCFs and interestingly no individual carried the common epidemic strain PCR-ribotype 027 (NAP1/BI). Further follow-up of asymptomatic carriers in the community, is required to evaluate host susceptibility to CDI and identify dynamic changes in the host and microbial environment that are associated with pathogenicity.Keywords
This publication has 35 references indexed in Scilit:
- Human Hypervirulent Clostridium difficile Strains Exhibit Increased Sporulation as Well as Robust Toxin ProductionJournal of Bacteriology, 2010
- Comparison of Nine Commercially Available Clostridium difficile Toxin Detection Assays, a Real-Time PCR Assay for C . difficile tcdB , and a Glutamate Dehydrogenase Detection Assay to Cytotoxin Testing and Cytotoxigenic Culture MethodsJournal of Clinical Microbiology, 2009
- Comparative genome and phenotypic analysis of Clostridium difficile 027 strains provides insight into the evolution of a hypervirulent bacteriumGenome Biology, 2009
- Increased Sporulation Rate of Epidemic Clostridium difficile Type 027/NAP1Journal of Clinical Microbiology, 2008
- Clostridium difficile: changing epidemiology and new treatment optionsCurrent Opinion in Infectious Diseases, 2007
- Gastric Juice: A Barrier Against Infectious DiseasesBasic & Clinical Pharmacology & Toxicology, 2005
- Multiplex PCR Targetingtpi(Triose Phosphate Isomerase),tcdA(Toxin A), andtcdB(Toxin B) Genes for Toxigenic Culture ofClostridium difficileJournal of Clinical Microbiology, 2004
- Development of a new PCR-ribotyping method for Clostridium difficile based on ribosomal RNA gene sequencingFEMS Microbiology Letters, 1999
- Stool Form Scale as a Useful Guide to Intestinal Transit TimeScandinavian Journal of Gastroenterology, 1997
- Clostridium difficile toxin in asymptomatic neonatesThe Journal of Pediatrics, 1982