A 1-year prospective study was conducted to identify enteropathogens in adults with diarrhea (n=851) and in healthy control subjects (n=203) by use of conventional laboratory methods. Virulence factor genes for diarrheagenic Escherichia coli were detected by polymerase chain reaction. Enteropathogens were identified in 56% of patients and 16% of control subjects. The isolation rate was 65% for patients with symptoms for <1 week and for travelers; >1 pathogen was found in 11% of patients. The most frequent enteropathogens were Campylobacter (13% of patients), Clostridium difficile (13%), enterotoxigenic Escherichia coli (8%), Salmonella (7%), Shigella (4%), Blastocystis hominis (4%), calicivirus (3%), rotavirus (3%), enteroaggregative E. coli (2%), Aeromonas (2%), Giardia intestinalis (2%), Cryptosporidium (2%), and astrovirus (2%). Less frequently isolated (< or =1% of patients) were verotoxigenic E. coli, enteropathogenic E. coli, enteroinvasive E. coli, Entamoeba histolytica/Entamoeba dispar, microsporidia, and adenovirus. Fifty percent of the patients were hospitalized, and 43% needed intravenous fluids. The median duration of diarrhea was 14 days. Clinical features were not helpful for predicting the etiology of diarrhea.

We investigated in vivo and in vitro yields of toxins A and B from and PCR ribotypes of Clostridium difficile isolates from 164 patients with differing severities of C. difficile-associated diarrhea (CDAD) (patients were grouped as follows: <3 loose stools per day, n ‫؍‬ 45; 3 to 10 per day, n ‫؍‬ 97; >10 per day, n ‫؍‬ 22). The median fecal toxin levels in each group were 0.5, 6.8, and 149 U/g feces (P < 0.001), respectively. Patients with severe diarrhea also had more-frequent occurrence of blood in stool and vomiting, but there was no association with fecal toxin levels per se. There was no correlation between fecal toxin level and toxin yield in vitro for the corresponding C. difficile isolate or between its PCR ribotype and disease severity. A broad range of toxin yields among isolates belonging to major PCR ribotypes indicated a presence of many subtypes. We hypothesize that bacterial and host factors that affect C. difficile toxin levels in feces are important determinants of symptoms in CDAD patients. An inverse correlation between toxin yield and spore count (r ‫؍‬ 0.66) in stationary-phase cultures supported the notion that toxin production and sporulation represent opposite alternative survival strategies for C. difficile cells facing nutrient shortage.Most strains of Clostridium difficile produce two toxins, A and B, that cause C. difficile-associated diarrhea (CDAD) with symptoms ranging from mild diarrhea to pseudomembranous colitis. CDAD is associated mainly with the use of antibiotics that reduce the protective microflora, which allows for overgrowth and toxin production by C. difficile (21), and chemostat and animal studies have verified that certain antibiotics induce C. difficile growth, toxin production, and toxin release (11,29,31). Furthermore, the age of the patient, underlying diseases, and levels of toxin-neutralizing antibodies are factors that affect attack rate, severity of disease, and the risk of relapse of CDAD (17,18,21,38). In addition, factors that differ between toxin-producing C. difficile strains, e.g., the amount of toxin produced, the serogroup, and the surface layer protein composition, may affect symptoms (12,14,20,25,32,33). For example, strains of C. difficile belonging to specific serogroups are highly virulent in animal models (3,8), but whether C. difficile strain types differ in terms of virulence in humans is less clear.The epidemiology and disease pattern of C. difficile strains have been studied by several methods, e.g., serotyping, toxinotyping, and PCR ribotyping (4). A cohort study showed no difference in the distributions of C. difficile immunoblot types between asymptomatic carriers and CDAD patients, suggesting that patient factors or bacterial numbers contribute to disease more than the properties of specific C. difficile strain types (24). In addition, for a total of 62 C. difficile strains isolated from 17 patients with CDAD and 11 carriers and typed by PCR ribotyping and by use of randomly amplified polymorphic DNA, no significant correlation between ge...

A point-prevalence survey of five European university hospitals was performed to benchmark antimicrobial drug use in order to identify potential problem areas in prescribing practice and to aid in establishing appropriate and attainable goals. All inpatients at the university hospitals of Rijeka (Croatia), Tartu (Estonia), Riga (Latvia), Vilnius (Lithuania) and Karolinska-Huddinge (Sweden) were surveyed for antimicrobial drug use during a single day. The frequency of antimicrobial drug use was 24% in Rijeka, 30% in Tartu, 26% in Riga, 14% in Vilnius and 32% in Huddinge. Surgical patients were treated with antimicrobial agents more often than medical patients in Riga (53% vs. 31%), Tartu (39% vs. 26%) and Vilnius (54% vs. 25%). Two-thirds of patients in Rijeka, Tartu, Riga and Vilnius, and fewer than half of the patients in Huddinge, received antimicrobial agents intravenously. Broad-spectrum antimicrobial agents were used most commonly in Rijeka. The prevalence of nosocomial infections treated with antibiotics was 9% at Huddinge, and 3-5% at the other centres. Benchmarking antimicrobial drug use at five university hospitals identified differences and problem areas. The high rates of intravenous administration, poor compliance with guidelines, and prolonged surgical prophylaxis were general problems that deserved specific attention at all centres. A change in prescription practices may reduce unnecessary drug use and decrease antimicrobial resistance.

Fecal samples from a 1-year prospective study were investigated to establish the role of group C rotavirus infections in acute diarrhea in Swedish adults (>15 years old). Rotaviruses were found in samples from 3% of the patients, and, in 35% of these, group C rotavirus was detected. Clinical symptoms of group C rotavirus infection were generally milder than those of group A rotavirus infection. Gene 8 (vp7) from 12 group C isolates, including strains from the prospective study, a military outbreak, and a sporadic case, was sequenced. The gene was found to be extremely conserved, with identities of 99.1%-100% at the amino acid level. This study has systematically investigated the prevalence and genetic diversity of group C rotavirus in adults. The data confirm the extreme sequence conservation within human group C rotavirus strains and suggest that symptomatic group C rotavirus infections occur more frequently in adults than has been previously recognized.