Receptors of the P2X7 type have been demonstrated in granulocytes, monocytes/macrophages, B and T lymphocytes, and have been involved in several cellular mechanisms including those related to inflammation and immunological response. This study attempted to investigate the role of these receptors on the inflammatory and fibrogenic response in the kidneys of unilateral ureteral obstruction (UUO), by using P2X7 knockout mice (-/-). C57Bl6 mice were submitted to left UUO and killed after 7 and 14 days. Histopathology using hematoxylin-eosin, periodic-acid Schiff and Sirius-red staining, immunohistochemistry for macrophages, myofibroblasts, transforming growth factor-beta (TGF-beta)1 and P2X7, and immunofluorescence for apoptotic cells (terminal deoxynucleotidyltransferase-mediated deoxyuridine triphosphate nick-end labeling) were performed. Protocols were as follows: (1) control; (2) sham; (3) control P2X7 (-/-); (4) sham P2X7 (-/-); (5) UUO wild type (WT); (6) UUO P2X7 (-/-). Myofibroblasts and Sirius-red staining were significantly lower in UUO P2X7 (-/-) mice at days 7 and 14, compared to UUO WT. Kidneys from UUO P2X7 (-/-) mice showed reduced number of inflammatory cells at day 14 but not at day 7, compared to UUO WT. TGF-beta1 was less in UUO P2X7 (-/-) mice at days 7 and 14 when compared to UUO WT. Macrophage infiltration and tubular apoptosis were lower in UUO P2X7 (-/-) at day 14 but not at day 7, compared to UUO WT. P2X7 was expressed only in tubular epithelial cells at day 7 of UUO WT mice. These findings constitute the first evidence that P2X7 receptors are implicated in macrophage infiltration, collagen deposition and apoptosis in response to ureteral obstruction in mice.

Background Staphylococcus epidermidis is an opportunistic pathogen involved in hospital-acquired infections, particularly in those related to medical devices. This study characterized 50 genetically unrelated S. epidermidis isolates from bloodstream infections (BSIs, n = 31) and nares (n = 19) of neonates in relation to staphylococcal chromosomal cassette mec (SCCmec) type, biofilm production and associated genes, and the arginine catabolic mobile elements (ACME), in order to detect virulence factors that could discriminate a potential invasiveness isolate or predict an increasing pathogenicity.ResultsIsolates from both groups showed no difference for biofilm production and ACME genes detection. However, BSI isolates harbored more frequently the sdrF and sesI genes (p < 0.05), whereas biofilm producer isolates were associated with presence of the aap gene. The sdrF gene was also significantly more in the biofilm producer isolates from BSI. The SCCmec type IV and the ccr2 complex were related to BSI isolates (p < 0.05), while 83% of the nasal isolates were non-typeable for the SCCmec elements, with the mec complex and ccr undetectable as the most frequent profile.ConclusionsDespite the great clonal diversity displayed by S. epidermidis isolates from neonates, BSI isolates harbored more frequently the sdrF and sesI adhesin genes, while nasal isolates were very variable in SCCmec composition. These aspects could be advantageous to improve colonization in the host increasing its pathogenicity.

Clostridium difficile strains were detected in 14 of 210 (6 . 7 %) faecal samples from children in Rio de Janeiro, Brazil, by cultivating faeces on cycloserine/cefoxitin/fructose agar after alcohol-shock. Two main groups of children were studied: inpatients (n ¼ 96) and outpatients (n ¼ 114). The inpatient group consisted of children on antibiotics or immunosuppressors who presented with diarrhoea and other children who did not present with diarrhoea and were not under an antibiotic or chemotherapeutic regimen. Among the outpatients, two groups were examined: namely, a group that comprised children who presented with diarrhoea and were occasionally under an antibiotic regimen and another group that comprised patients who were not taking antibiotics. After cytotoxic assay, toxigenic C. difficile (Cd tox þ ) strains were detected in 4 . 2 % of inpatients and 3 . 5 % of outpatients. Exclusion of other infectious causes of diarrhoea indicated a typical case of C. difficileassociated paediatric diarrhoea in the community. Among Cd tox þ isolates, no variations were detected by PCR for toxin A that employed primers NK9 and NKVO11. No resistance was found to metronidazole or vancomycin among strains that were isolated from children who presented with diarrhoea, but the MIC 50 and MIC 90 values for clindamycin were 6-8 and 16 ìg ml À1 , respectively.Resistance to clindamycin seems to be more disseminated in strains from outpatients than in those from inpatients (P , 0 . 05). In conclusion, these data suggest that investigation for C. difficile infection should be taken into account in paediatric diarrhoea in both inpatients and outpatients in developing countries.

A total of 35 Brazilian isolates of Clostridium difficile from faecal stools and four isolates from hospital environments were analyzed by PCR ribotyping. A whole cell protein profile (as an alternative for serogrouping), in vitro toxin production and susceptibility to vancomycin, metronidazole and clindamycin were also investigated. All strains were typeable by both phenotypic and genotypic methods, and a total of 13 different PCR ribotypes were identified, of which seven (132, 133, 134, 135, 136, 142 and 143) were considered new types and accounted for 78.5% of all samples evaluated (including hospital environments). A non-toxigenic C. difficile PCR ribotype 133 was detected in all children groups examined (inpatients, outpatients and healthy children), whilst toxigenic PCR ribotypes 015, 131, 134 and 135 were associated mostly with symptomatic children. Serogroups G and D were disseminated both in patients from the community and from the pediatric hospital, with group G prevalent among outpatient children. All strains were susceptible to vancomycin and metronidazole but high levels of resistance to clindamycin were found, especially among serogroups G and D. Co-existence of different ribotypes and serogroups in the same individual was observed. The new seven ribotypes found in this investigation may represent strains characteristic of this region of Brazil.

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Fusobacterium nucleatum is a gram-negative non-spore-forming, non-motile, obligate anaerobic rod that is normally isolated from the oral cavity. Several studies have reported a significant heterogeneity within the F. nucleatum species. The aim of the present study was to analyze the clonal diversity of F. nucleatum strains isolated from intracanal infections and to evaluate the presence of Enterobacterial Repetitive Intergenic Consensus (ERIC)-like sequences in the genome of F. nucleatum. Samples were collected from 13 single-root teeth from adult patients, all having carious lesions, necrotic pulps and radiographic evidence of periradicular bone loss. F. nucleatum was isolated from two different patients (subjects 5 and 7) by culture. Amplification of 19 colonies from subject 5 and 15 colonies from subject 7 using ERIC primers resulted in four clonal types, two per subject. An intense amplicon of approximately 700 bp was generated by ERIC-PCR for all F. nucleatum isolates and F. nucleatum ssp. polymorphum ATCC 10953. The amplification reaction using primer 1254 confirmed the results obtained with the ERIC primer. Our findings indicate that DNA fingerprints provided by ERIC- and Arbitrarily Primed (AP)-PCR may constitute a powerful tool for investigating F. nucleatum clonal diversity.

Bacteroides fragilis, a component of the normal flora and an important anaerobic pathogen in non-intestinal endogenous infections, has recently been associated with enteric diseases. In this study, 41 B. fragilis strains were analysed in relation to their genetic diversity. This collection included two reference strains (ATCC 23745 and 25285), 20 isolates from non-intestinal infections, six from intestinal infections, five from intestinal microflora and eight from an aquatic environment. The fingerprints were generated by using two repetitive sequences (REP and ERIC) as primers to PCR (rep-PCR). A dendrogram was obtained with the Taxotron1 Program. Three clusters (threshold genotypes I, II and III) were observed when the genetic distance was 0.30. These results confirm previous data found regarding the genotypical diversity of B. fragilis.