Clostridium difficile PCR ribotype 027 comprised 0.2% of a collection of Swedish isolates in 1997-2001 (3 of 1,325 isolates). These isolates had lower moxifloxacin MICs than the epidemic type 027 isolates, but they had the same tcdC sequence and toxin yield. Type 027 produced 3-to 13-fold more toxin than did major Swedish types. One epidemic strain (027/NAP1a) sporulated more than did other type 027 isolates, a feature that should contribute to its survival and spread.

Background Giardia intestinalis is one of the most common diarrhea-related parasites in humans, where infection ranges from asymptomatic to acute or chronic disease. G. intestinalis consists of eight genetically distinct genotypes or assemblages, designated A–H, and assemblages A and B can infect humans. Giardiasis has been classified as a possible zoonotic disease but the role of animals in human disease transmission still needs to be proven. We tried to link different assemblages and sub-assemblages of G. intestinalis isolates from Swedish human patients to clinical symptoms and zoonotic transmission.Methodology/Principal FindingsMultilocus sequence-based genotyping of 207 human Giardia isolates using three gene loci: ß-giardin, glutamate dehydrogenase (gdh), and triose phosphate isomerase (tpi) was combined with assemblage-specific tpi PCRs. This analysis identified 73 patients infected with assemblage A, 128 with assemblage B, and six with mixed assemblages A+B. Multilocus genotypes (MLGs) were easily determined for the assemblage A isolates, and most patients with this genotype had apparently been infected through anthroponotic transmission. However, we also found evidence of limited zoonotic transmission of Giardia in Sweden, since a few domestic human infections involved the same assemblage A MLGs previously reported in Swedish cats and ruminants. Assemblage B was detected more frequently than assemblage A and it was also more common in patients with suspected treatment failure. However, a large genetic variability made determination of assemblage B MLGs problematic. Correlation between symptoms and assemblages was found only for flatulence, which was significantly more common in children less than six years of age infected with assemblage B.Conclusions/SignificanceThis study shows that certain assemblage A subtypes are potentially zoonotic and that flatulence is connected to assemblage B infections in young children. Determination of MLGs from assemblages A and B can be a valuable tool in outbreak situations and to help identify possible zoonotic transmission.

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.

This study describes the epidemiology and symptoms in 271 cryptosporidiosis patients in Stockholm County, Sweden. Species/genotypes were determined by polymerase chain reaction-restriction fragment-length polymorphism (PCR-RFLP) of the Cryptosporidium oocyst wall protein (COWP) and 18S rRNA genes. Species were C. parvum (n=111), C. hominis (n=65), C. meleagridis (n=11), C. felis (n=2), Cryptosporidium chipmunk genotype 1 (n=2), and a recently described species, C. viatorum (n=2). Analysis of the Gp60 gene revealed five C. hominis allele families (Ia, Ib, Id, Ie, If), and four C. parvum allele families (IIa, IIc, IId, IIe). Most C. parvum cases (51%) were infected in Sweden, as opposed to C. hominis cases (26%). Clinical manifestations differed slightly by species. Diarrhoea lasted longer in C. parvum cases compared to C. hominis and C. meleagridis cases. At follow-up 25-36 months after disease onset, 15% of the patients still reported intermittent diarrhoea. In four outbreaks and 13 family clusters, a single subtype was identified, indicating a common infection source, which emphasizes the value of genotyping for epidemiological investigations.

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...

To compare the efficacy of oral doxycycline and IV penicillin G for the treatment of neuroborreliosis, we randomized consecutive patients with Lyme neuroborreliosis to receive either IV penicillin G (3 g q 6 h) or oral deoxycycline (200 mg q 24 h) for 14 days. All patients had antibodies against Borrelia burgdorferi in serum, CSF, or both, or had a positive CSF culture. Twenty-three patients randomized to penicillin G and 31 patients to doxycycline were included in the study. All patients improved during treatment, and there were no significant differences between the two treatment groups in patient scoring, CSF analysis, or serologic and clinical follow-up during 1 year. There were no treatment failures, although one patient in each treatment group was re-treated because of residual symptoms. In conclusion, oral doxycycline is an adequate and cost-effective alternative to IV penicillin for the treatment of Lyme neuroborreliosis.

Enterotoxigenic strains of Bacteroides fragilis (ETBF) have been associated with diarrheal diseases in animals and humans. The enterotoxin of ETBF induces fluid changes in ligated intestinal segments and a cytotoxic response in HT29/C1 cells. An assay based on immunomagnetic-beads separation in combination with PCR was used to detect ETBF in fecal samples from patients with diarrhea and healthy Swedish adults. A total of 922 fecal samples were analyzed in this study, including 728 samples from patients with diarrhea and 194 samples from controls. ETBF was detected in 195 of 728 patients (26.8%) and 24 of 194 healthy controls (12.4%). The difference between the two groups was statistically significant (P<.01). ETBF was the only potential diarrheal agent in 91 (12.5%) of 728 patients. All ETBF-positive samples from patients and controls were also positive in the HT29/C1 assay. The data show high carriage of ETBF in Swedish adults, which might be associated with diarrheal disease.

Attempts were made to culture spirochetes from cerebrospinal fluid samples of 105 patients suspected of having Lyme borreliosis with neurological complications. At the final evaluation, only 38 patients fulfilled the criteria of neuroborreliosis. Spirochetes were cultured from cerebrospinal fluid samples of four of these patients. Ail four patients had pleocytosis in their cerebrospinal fluid and a history of neurological symptoms of only 4 to 10 days in duration. Two of them had no detectable antibodies against any of the isolated spirochetes in their cerebrospinal fluid, both when tested with an enzyme-linked immunosorbent assay and when tested by immunoblotting. An antibody reaction against the homologous isolate that was distinctly stronger than that against the heterologous isolates was found in the serum and cerebrospinal fluid samples from one patient. The cells of the isolates were morphologically similar and showed a very similar protein pattern when analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cells of all isolates reacted with the monoclonal antibodies H5332 and H9724, which also react with Borrelia burgdorferi B31, the type strain. One isolate lost a major protein of 23 kilodaltons after subcultivation for 4 months. We conclude that isolation of spirochetes from cerebrospinal fluid might prove successful in clinically selected cases of Lyme borreliosis.