Molecular epidemiology of Clostridium difficile in Southampton 2001-2005

transillumination. Gel images were stored electronicallyand analysed using BioNumerics� software.

Results: PCR ribotype patterns were obtained for all iso-lates. Patterns contained from 6 to 9 bands ranging in sizebetween 260 and 720 bp. Five clusters were obtained atsimilarity levels greater than 90% (A, B, B+, C and D).Thirty-one of 44 isolates examined were of pattern B, andwere widespread in time and place, being isolated from pa-tients in hospitals 1, 2, and 3, and from samples submittedfrom March through July 2006. Pattern A was present in 5isolates from 5 different wards at hospital 2 and 4 isolatesfrom hospital 4. The remaining patterns were present inonly one or two individual isolates.

Conclusion: PCR-ribotyping was simple, rapid and repro-ducible. BioNumerics� software provided an invaluable toolfor storage and analysis of data. Use of standard methodol-ogy should allow comparison of patterns generated herewith those archived at the PHLS Anaerobic ReferenceUnit, Cardiff.

P 108

ADDITIONAL YIELD OF FAECAL SCREENING TODETECT MRSA CARRIAGE AMONG HOSPITALIZEDPATIENTS WITH DIARRHOEA

Gupta R, Cheesbrough JSRoyal Preston Hospital, Lancashire Teaching Hospitals NHSFoundation Trust, Fulwood, Preston PR2 9HT

Background: The standard method currently recommen-ded for detecting MRSA carriage among hospitalised pa-tients is to culture the following sites: anterior nares, skinlesions and wounds, sites of indwelling catheters, catheterurine, groin/perineum and sputum.

The role of faecal carriage as a major reservoir, which ispotentially a source of cross infection, remainscontroversial.

Aim: To assess the incremental yield of faecal MRSA cul-ture, among inpatients with diarrhoea, admitted to Lanca-shire Teaching Hospitals NHS Trust (LTHTR).

Methods: Study population: In-patients at LTHTR be-tween April and July 2006.

Study sample 1 MRSA detected by current screeningmethods

All patients in whom MRSA was detected, from any site,by routine laboratory procedures including admissionscreening of patients in Critical care, Neurosurgery andElective Orthopaedics.

Study sample 2 In-patients with liquid faeces submittedfor C. difficile toxin testing.

Laboratory methods: Faecal suspensions were dilutedinto maximum recovery diluent (MRD) and were platedonto MRSA ID, a Chromogenic agar medium (BioMerieux).

Results: Over a period of 4 months, MRSA was isolatedfor the first time from routine clinical specimens, includingscreening of standard body sites, from 214 patients. Overthe same period, 1375 samples were submitted for C. diffi-cile testing from 896 patients. MRSA was detected in thefaeces of 93 patients. Fifty-five (20.4%) of these were pre-viously not known to be MRSA carriers. C. difficile toxin wasdetected by EIA in 82 patients.

Conclusion: Faecal specimens yielded the first isolate ofMRSA in 20.4% of detected carriers. Thirty-four percent ofall MRSA carriers were also faecal carriers of MRSA.

The screening of faecal specimens, submitted for C. dif-ficile toxin testing, for MRSA, is a simple way of improvingMRSA surveillance among hospitalised patients.

Abstracts e93

P 107

MOLECULAR EPIDEMIOLOGY OF CLOSTRIDIUMDIFFICILE IN SOUTHAMPTON 2001-2005

Green S, Cortes N, Prime K, Hadfield SHealth Protection Agency South East, SouthamptonLaboratory, Southampton General Hospital, Southampton

Background: C. difficile infection is the major cause ofhospital-acquired diarrhoea in the UK and can result in life-threatening complications. Disease is associated with anti-biotic use and results from production of toxins A and B. Mo-lecular typing of isolates by PCR ribotyping has identifiedover 100 ribotypes in the UK. In 2003, a hypertoxin-produc-ing strain (ribotype 027), associated with an epidemic of se-vere disease and fluoroquinolone use in Canada, wasdetected during an outbreak at Stoke Mandeville Hospitaland has subsequently spread to hospitals throughout theUK, including Southampton University Hospitals Trust(SUHT). The aims of this study were to identify ribotypes re-sponsible for C. difficile infections at SUHT between 2001and 2005 and determine the antimicrobial sensitivities ofrecently circulating ribotypes.

Methods: C. difficile was isolated from faecal samplespositive for toxins A & B (Tox A/B II�, TechLab) collected in2001, 2003/4 and 2005 (n¼ 286). PCR ribotypes were deter-mined by amplification of the ribosomal 16S-23S variablespacer region. The antimicrobial susceptibilities to 12 antibi-otics of isolates from 2005 were measured by E-test (ABBiodisk).

Results: PCR ribotype 001 was found to be the predomi-nant strain in 2001 (73% of isolates). By 2003/4, ribotype106 (not detected in 2001) had emerged (80% of isolates)and displaced ribotype 001 (15%). In 2005, ribotype 106(64%) remained the most frequently detected, whilst ribo-type 001 was not found. The first ribotype 027 isolates atSUHT (5%)werealsodetected. Ribotypes027and106had sim-ilar antimicrobial susceptibilities and were resistant to eryth-romycin and moxifloxacin, unlike less common ribotypes.

Conclusions: There has been a dramatic shift in the mo-lecular epidemiology of C. difficile at SUHT since 2001, withribotype 001 being displaced by ribotype 106. A small num-ber of the potentially hypertoxin-producing ribotype 027strains were detected in 2005. A rise in the prevalence ofthis strain could have a significant impact on C. difficile-associated morbidity and mortality in the UK and requireson-going surveillance.