The chemical composition of ethanol extracts from samples of Brazilian propolis (EEPs) determined by HPLC and their activity against Trypanosoma cruzi, Staphylococcus aureus, Streptococcus pneumoniae, Klebisiella pneumoniae, Candida albicans, Sporothrix schenckii and Paracoccidioides brasiliensis were determined. Based on the predominant botanical origin in the region of samples' collection, the 10 extracts were separated into three groups: A (B. dracunculifolia + Auraucaria spp), B (B. dracunculifolia) and C (Araucaria spp). Analysis by the multiple regression of all the extracts together showed a positive correlation, higher concentrations leading to higher biological effect, of S. aureus with p-coumaric acid (PCUM) and 3-(4-hydroxy-3-(oxo-butenyl)-phenylacrylic acid (DHCA1) and of trypomastigotes of T. cruzi with 3,5-diprenyl-4-hydroxycinnamic acid derivative 4 (DHCA4) and 2,2-dimethyl-6-carboxyethenyl-2H-1-benzopyran (DCBEN). When the same approach was employed for each group, due to the small number of observations, the statistical test gave unreliable results. However, an overall analysis revealed for group A an association of S. aureus with caffeic acid (CAF) and dicaffeoylquinic acid 3 (CAFQ3), of S. pneumoniae with CAFQ3 and monocaffeoylquinic acid 2 (CAFQ2) and of T. cruzi also with CAFQ3. For group B, a higher activity against S. pneumoniae was associated DCBEN and for T. cruzi with CAF. For group C no association was observed between the anitmicrobial effect and any component of the extracts. The present study reinforces the relevance of PCUM and derivatives, especially prenylated ones and also of caffeolyquinic acids, on the biological activity of Brazilian propolis.

Aims:The chemical composition of ethanol extracts from a Brazilian (Et-Bra) and a Bulgarian (Et-Blg) propolis, and their activity against the protozoan Trypanosoma cruzi, several fungi and bacteria species were determined. Methods and Results: The chemical composition was determined by high temperature high resolution gas chromatography coupled to mass spectrometry. Microbiological activity was assayed in vitro against T. cruzi, Candida albicans, Sporothrix schenckii, Paracoccidioides brasiliensis, Neisseria meningitidis, Streptococcus pneumoniae and Staphylococcus aureus. Conclusions: Et-Bra and Et-Blg, although with totally distinct compositions, were active against T. cruzi and the three species of fungi. Et-Blg was more effective than Et-Bra against bacteria, particularly N. meningitidis and Strep. pneumoniae. Significance and Impact of the Study: Although with different classes of components, both propolis extracts showed microbicidal activity. For the bactericidal activity it was possible to establish a positive correlation with the high content of flavonoids of the Bulgarian extract.

Virulence properties and genetic variation as determined by multilocus enzyme electrophoresis were studied in 70 strains of Escherichia coli O55, a common serogroup of enteropathogenic E. coli (EPEC), a major cause of infantile diarrhea in developing countries. Nearly 40% of the strains were originally isolated in Brazil and represented serotypes O55:H6, O55:H7, and O55:H51 and nonmotile (O55:H؊) strains. The analysis of electrophoretic variants of 20 enzymes defined seven distinct electrophoretic types (ETs). ET 1 was represented by 41% of the strains, including strains which usually hybridized with DNA probes for the intimin gene (eaeA), the EPEC adherence plasmid (EAF), and the gene for the pilin subunit of the bundle-forming pilus (bfpA). The ET 1 strains were also typically serotype O55:H6, displayed localized adherence (LA) in tissue culture assays, and were positive in the fluorescent-actin staining test for intimate cell adherence. These same characteristics were observed in the closely related ETs 2 to 4, which clustered in the same branch as ET 1. No known virulence marker could be identified in ET 6. ET 5 included 23 strains, all of which carried the eaeA gene but otherwise displayed a striking array of distinct virulence traits. This ET was represented by O55:H7 strains with phenotypes as diverse as the simultaneous expression of LA and diffuse adherence and the ability to form a newly described adherence pattern, called LA-like adherence. The results suggest that ET 5 marks a special pathogenic clone with a propensity to acquire virulence factors which may facilitate the emergence of new pathogenic strains.

The species Escherichia coli is serologically divided in serogroups and serotypes on the basis of its antigenic composition (somatic or O antigens for serogroups and flagelar or H antigens for serotypes). Many strains express a third class of antigens (capsular or K antigens) that although important in pathogenesis only occasionally are used in serotyping.The species comprise intestinal and extraintestinal pathogens. The intestinal pathogens are also known as diarrheagenic E. coli (DEC) of which six categories have been characterized: enteropathogenic E. coli (EPEC), enterohaemorrhagic E. coli (EHEC), enterotoxigenic E. coli (ETEC), enteroinvasive E. coli (EIEC), enteroaggregative E. coli (EAEC), and diffusely adhering E. coli (DAEC) (Nataro & Kaper 1998). Recently EPEC has been divided in typical EPEC (t-EPEC) and atypical EPEC (a-EPEC) . There are many differences between these categories but in routine they are defined by a few virulence markers (Table I). The extraintestinal pathogens (EXPEC) more frequent includes the strains associated with urinary tract infections (UPEC), neonatal meningitis (MAEC), and bacteremia. For an excellent review on DEC see Nataro and Kaper (1998) and on E. coli in general Gyles (1994). E. coli is also a very important veterinary pathogen (Gyles 1994 (WHO 1987). At this time already there were studies showing that at least some of these serogroups contained different diarrheagenic serotypes but their pathogenic diversity only latter became really clear (Nataro & Kaper 1998).During the last 10 years we have studied most of the EPEC O serogroups in regard to DEC categories, serotypes, clones, and genetic relationships. The purpose of this article is to review these characteristics. It is based on the study of 805 strains of serogroups O26, O55, O86, O111, O114, O119, O125, O126, O127, O128, and O142 most of which were isolated in São Paulo from children with diarrhea between 1970 and 1990. All strains were studied in regard to adhesion patterns, virulence genes implicated in the definition of the DEC category, and serotypes. The strains of serogropus O55, O111, and O119 were also studied by MLEE and a representative number of strains of serogroups O86, O127, O128, and O142 were studied by ribotyping. Serogroup O26 was studied by RAPD. Potential virulence factors were studied in a representative number of strains of the DEC categories detected (Campos et al. 1994, Valle et al. 1997, Gonçalves et al. 1997, Monteiro-Neto et al. 1997, Dias 1998, Valle 1998, Ghilardi et al. 2003. Other studies performed will be mentioned during the review. DEC CATEGORIES IN THE EPEC O SEROGROUPSThe DEC categories and the number of strains of each category as well the number of avirulent strains are shown in Table II. Typical EPEC was the most frequent category followed by EAEC, atypical EPEC, ETEC, and EHEC. EIEC and DAEC were not found among the strains tested. A number of strains showed the diffuse adherence (DA) pattern but they proved to belong to the ETEC, EAEC, and atypical EPEC categories. The n...

Genetic variation among isolates of Escherichia coli 0111 obtained mostly from patients with diarrhea in Brazil was assessed by multilocus enzyme electrophoresis to characterize chromosomal genotypes and by gene probes and adherence assays to characterize virulence properties. Among the 152 isolates, we resolved 16 distinct electrophoretic types (ETs), which differed on average at 40% of the enzyme loci. We identified four major bacterial 0111 clones of different disease classes: ET 12, which includes the bulk of the enteropathogenic E. coli strains, typically showing localized adherence and intimate attachment in tissue culture assays; ET 1,