Variations in testing for Clostridium difficile infection can hinder patients' care, increase the risk of transmission, and skew epidemiological data. We aimed to measure the underdiagnosis of C difficile infection across Europe. We did a questionnaire-based study at 482 participating hospitals across 20 European countries. Hospitals were questioned about their methods and testing policy for C difficile infection during the periods September, 2011, to August, 2012, and September, 2012, to August, 2013. On one day in winter, 2012-13 (December, 2012, or January, 2013), and summer, 2013 (July or August), every hospital sent all diarrhoeal samples submitted to their microbiology laboratory to a national coordinating laboratory for standardised testing of C difficile infection. Our primary outcome measures were the rates of testing for and cases of C difficile infection per 10 000 patient bed-days. Results of local and national C difficile infection testing were compared with each other. If the result was positive at the national laboratory but negative at the local hospital, the result was classified as undiagnosed C difficile infection. We compared differences in proportions with the Mann-Whitney test, or McNemar's test if data were matched. During the study period, participating hospitals reported a mean of 65·8 tests (country range 4·6-223·3) for C difficile infection per 10 000 patient-bed days and a mean of 7·0 cases (country range 0·7-28·7) of C difficile infection per 10 000 patient-bed days. Only two-fifths of hospitals reported using optimum methods for testing of C difficile infection (defined by European guidelines), although the number of participating hospitals using optimum methods increased during the study period, from 152 (32%) of 468 in 2011-12 to 205 (48%) of 428 in 2012-13. Across all 482 European hospitals on the two sampling days, 148 (23%) of 641 samples positive for C difficile infection (as determined by the national laboratory) were not diagnosed by participating hospitals because of an absence of clinical suspicion, equating to about 74 missed diagnoses per day. A wide variety of testing strategies for C difficile infection are used across Europe. Absence of clinical suspicion and suboptimum laboratory diagnostic methods mean that an estimated 40 000 inpatients with C difficile infection are potentially undiagnosed every year in 482 European hospitals. Astellas Pharmaceuticals Europe.

Clostridium difficile infection (CDI) is the major cause of infective diarrhoea in healthcare environments. As part of the European, multicentre, prospective, biannual, point-prevalence study of Clostridium difficile infection in hospitalised patients with diarrhoea (EUCLID), the largest C. difficile epidemiological study of its type, PCR ribotype distribution of C. difficile isolates in Europe was investigated. PCR ribotyping was performed on 1,196 C. difficile isolates from diarrhoeal samples sent to the European coordinating laboratory in 2012–13 and 2013 (from two sampling days) by 482 participating hospitals from 19 European countries. A total of 125 ribotypes were identified, of which ribotypes 027 (19%, n =222), 001/072 (11%, n = 134) and 014/020 (10%, n = 119) were the most prevalent. Distinct regional patterns of ribotype distribution were noted. Of 596 isolates from patients with toxin-positive stools (CDI cases), ribotype 027 accounted for 22% (32/144) of infections in cases aged from 18 to less than 65 years, but the prevalence decreased in those aged ≥ 65 years (14% (59/412)) and further decreased in those aged ≥ 81 years (9% (18/195)). The prevalence of ribotype 027 and 176, but not other epidemic strains, was inversely proportional to overall ribotype diversity (R² = 0.717). This study highlights an increased diversity of C. difficile ribotypes across Europe compared with previous studies, with considerable intercountry variation in ribotype distribution. Continuous surveillance programmes are necessary to monitor the changing epidemiology of C. difficile.

This report describes a high-throughput assay to identify substances that reduce the frequency of conjugation in Gram-negative bacteria. Bacterial conjugation is largely responsible for the spread of multiple antibiotic resistances in human pathogens. Conjugation inhibitors may provide a means to control the spread of antibiotic resistance. An automated conjugation assay was developed that used plasmid R388 and a laboratory strain of Escherichia coli as a model system, and bioluminescence as a reporter for conjugation activity. Frequencies of conjugation could be measured continuously in real time by the amount of light produced, and thus the effects of inhibitory compounds could be determined quantitatively. A control assay, run in parallel, allowed elimination of compounds affecting cell growth, plasmid stability or gene expression. The automated conjugation assay was used to screen a database of more than 12 000 microbial extracts known to contain a wide variety of bioactive compounds (the NatChem library). The initial hit rate was 1·4 %. From these, 48 extracts containing active compounds and representing a variety of organisms and extraction conditions were subjected to fractionation (24 fractions per extract). The 52 most active fractions were subjected to a secondary analysis to determine the range of plasmid inhibition. Plasmids R388, R1 and RP4 were used as representatives of a variety of plasmid transfer systems. Only one fraction (of complex composition) affected transfer of all three plasmids, while four other fractions were active against two of them. Two separate compounds were identified from these fractions: linoleic acid and dehydrocrepenynic acid. Downstream analysis showed that the chemical class of unsaturated fatty acids act as true inhibitors of conjugation.