- Volume 55, Issue 5, 2006

The differences in faecal bacterial population between irritable bowel syndrome (IBS) and control subjects have been reported in several studies. The aim of the present study was to compare the predominant and clostridial faecal microbiota of IBS subjects and healthy controls by applying denaturing gradient gel electrophoresis (DGGE) and a recently developed multiplexed and quantitative hybridization-based technique, transcript analysis with the aid of affinity capture (TRAC). According to the results, the studied clostridial groups (Clostridium histolyticum, Clostridium coccoides-Eubacterium rectale, Clostridium lituseburense and Clostridium leptum) represented the dominant faecal microbiota of most of the studied subjects, comprising altogether 29–87 % of the total bacteria as determined by the hybridized 16S rRNA. The C. coccoides-E. rectale group was the dominant subgroup of clostridia, contributing a mean of 43 % of the total bacteria in control subjects and 30 % (constipation type) to 50 % (diarrhoea type) in different IBS symptom category subjects. The proportion of the C. coccoides-E. rectale group was found to be significantly lower in the constipation-type IBS subjects than in the control subjects. DNA-based PCR-DGGE and RNA-based RT-PCR-DGGE analyses targeted to the predominant bacterial population showed considerable biodiversity as well as uniqueness of the microbiota in each subject, in both control and IBS subject groups. The RT-PCR-DGGE profiles of the IBS subjects further indicated higher instability of the bacterial population compared to the control subjects. The observations suggest that clostridial microbiota, in addition to the instability of the active predominant faecal bacterial population, may be involved in IBS.

Legionella pneumonia can be difficult to diagnose. Existing laboratory tests all have shortcomings, especially the ability to diagnose all Legionella spp. at an early stage. Detection of Legionella DNA in serum can be a valuable tool for the diagnosis of Legionnaires' disease (LD). This report describes two patients with LD diagnosed by PCR using serum samples. In addition, quantification of L. pneumophila DNA using real-time PCR during the course of illness was carried out. The results obtained mirrored both the clinical condition and C-reactive protein values during the course of the illness. Quantification of Legionella DNA in serum using real-time PCR could be a valuable tool to monitor the effects of antimicrobial therapy in patients with LD.