Year: 2011
Type: dissertation
Abstract: [Truncated abstract] Clostridium difficile is an important nosocomial pathogen, the most frequent cause of infectious hospital-acquired diarrhoea. It has risen to prominence in the last decade due to the emergence of the hypervirulent NAP1/027 strain. Despite renewed interest in C. difficile and the infections it causes, little is known about the organism in Australia. In order to understand the molecular epidemiology of C. difficile in Australia, a large collection of isolates was characterised using molecular typing methods including PCR ribotyping and toxin gene PCR assays. A total of 773 human clinical isolates, 32 animal isolates, and 28 environmental isolates of C. difficile was toxin profiled by PCR for the toxin A, toxin B and binary toxin genes. The 773 human clinical isolates encompassed 624 (80.7%) A+B+, 139 (18.0%) AB strains, and 10 (1.3%) AB+ strains. Binary toxin genes were detected in 75 (9.7%) of the human isolates, with the highest proportion (70.0%) occurring among the AB+ strains. Among 752 human isolates ribotyped, 146 different ribotypes were identified. The most common human types in Australia were ribotype 014/020/255 (21.8%), 002 (8.4%), 010 (4.4%), 056 (3.6%), 070 (3.3%), 015 (2.7%) and 018 (2.4). The hypervirulent ribotype 027 strain was detected in Australia among humans only recently. Ribotype 078 was isolated from humans, but not from animals, although the closely related ribotype 126 was. The composition of the most common ribotypes in Australia was similar to that seen elsewhere, and ribotypes linked to higher morbidity and mortality elsewhere are common in Australia. A clindamycin-resistant ribotype 017, toxinotype VIII (AB+CDT) strain has been the most common AB+ strain isolated elsewhere in the world. Ribotype 017 isolates were detected among Australian isolates, but only constituted a minority of the AB+ isolates. A total of 10 AB+ ribotypes were identified in this study, nine of which have not been previously reported...
Author: Briony Elliott
Language: English
Subfield: Infectious Diseases
Field: Medicine
Domain: Health Sciences
Open Access status: green
OpenAlex ID: W2589626904