Search

Aims: The genetic diversity of Beauveria bassiana was investigated by comparing isolates of this species to each other (49 from different geographical regions of Brazil and 4 from USA) and to other Beauveria spp. Methods and Results: The isolates were examined by multilocus enzyme electrophoresis (MLEE), amplified fragment length polymorphism (AFLP), and rDNA sequencing. MLEE and AFLP revealed considerable genetic variability among B. bassiana isolates. Several isolates from South and Southeast Brazil had high similarity coefficients, providing evidence of at least one population with clonal structure. There were clear genomic differences between most Brazilian and USA B. bassiana isolates. A Mantel test using data generated by AFLP provided evidence that greater geographical distances were associated with higher genetic distances. AFLP and rDNA sequencing demonstrated notable genotypic variation between B. bassiana and other Beauveria spp. Conclusion: Geographical distance between populations apparently is an important factor influencing genotypic variability among B. bassiana populations in Brazil. Significance and Impact of the Study: This study characterized many B. bassiana isolates. The results indicate that certain Brazilian isolates are considerably different from others and possibly should be regarded as separate species from B. bassiana sensu latu. The information on genetic variation among the Brazilian isolates, therefore, will be important to comprehending the population structure of B. bassiana in Brazil. [ABSTRACT FROM AUTHOR]

Aims: Sheep are important carriers of Shiga toxin-producing Escherichia coli (STEC) in several countries. However, there are a few reports about ovine STEC in American continent. Methods and Results: About 86 E. coli strains previously isolated from 172 healthy sheep from different farms were studied. PCR was used for detection of stx1, stx2, eae, ehxA and saa genes and for the identification of intimin subtypes. Restriction fragment length polymorphism (RFLP)–PCR was performed to investigate the variants of stx1 and stx2, and the flagellar antigen ( fliC) genes in nonmotile isolates. Five isolates were eae+ and stx−, and belonged to serotypes O128:H2/β-intimin (2), O145:H2/γ, O153:H7/β and O178:H7/ε. Eighty-one STEC isolates were recovered, and the stx genotypes identified were stx1c stx2d-O118 (46·9%), stx1c (27·2%), stx2d-O118 (23·4%), and stx1c stx2dOX3a (2·5%). Pulsed-field gel electrophoresis (PFGE) revealed 27 profiles among 53 STEC and atypical enteropathogenic Escherichia coli (EPEC) isolates. Conclusions: This study demonstrated that healthy sheep in São Paulo, Brazil, can be carriers of potential human pathogenic STEC and atypical EPEC. Significance and Impact of the Study: As some of the STEC serotypes presently found have been involved with haemolytic uraemic syndrome (HUS) in other countries, the important role of sheep as sources of STEC infection in our settings should not be disregarded. [ABSTRACT FROM AUTHOR]

Aims: Leptospirosis is a public health problem worldwide. Traditionally, microscopic agglutination test (MAT) and cross-agglutinin absorption test (CAAT) are used to identify leptospires. However, these techniques are laborious and time-consuming, requiring the maintenance of a collection of more than 200 reference strains and correspondent rabbit antisera. The purpose of this study was to evaluate the pulsed-field gel electrophoresis (PFGE) method for discrimination of Leptospira serovars. Methods and Results: Fourteen clinical isolates of Leptospira spp. were analysed by MAT before being characterized by PFGE. The isolates were compared with a library of 206 different reference Leptospira serovars. All the isolates gave clear profiles with high resolution. PFGE and MAT results were in agreement for all clinical isolates evaluated. Twelve isolates were classified as serovar Icterohaemorrhagiae/Copenhageni by PFGE. By MAT, these isolates were classified as serogroup Icterohaemorrhagiae with titres ranging from 3200 to 25 600. Two isolates were classified as serovar Canicola by PFGE, and as serogroup Canicola by MAT with titres higher than 3200. Conclusions: PFGE offers the advantages of simple, reliable and reproducible results. Significance and Impact of the Study: PFGE provides a convenient tool for the identification of clinical isolates. [ABSTRACT FROM AUTHOR]

Fifty-one vancomycin-resistant enterococci samples isolated from different geographic regions in Brazil were studied. All the isolates harboured the vanA gene as demonstrated by PCR analysis, and in a majority of strains the gene was associated with a transferable plasmid of 70 kb. A single variant of the prototype Tn 1546 associated with common transferable vanA-containing plasmids has spread among the enterococcal strains circulating in Brazil. The VanA element integrity in these enterococci strains and the different pulsed-field gel electrophoresis patterns suggest horizontal transmission of the vancomycin resistance transposon in Brazilian strains. [ABSTRACT FROM AUTHOR]

Summary: Diffuse cutaneous leishmaniasis (DCL) is characterised by multiple and progressive cutaneous lesions, resistance to chemotherapy and Leishmania-specific T-cell anergy. We report the first autochthonous DCL case and the first human infection with Leishmania amazonensis in Rio de Janeiro State, Brazil, where only L. braziliensis is considered to be the causative agent of cutaneous leishmaniasis. Leishmania amazonensis was identified by multilocus enzyme electrophoresis and PCR-RFLP. Our case was diagnosed as DCL according to clinical, parasitological, histopathological and immunological criteria. These observations indicate that L. amazonensis is increasing its geographical distribution in Brazil, accounting for unusual clinical presentations in new transmission areas. [Copyright &y& Elsevier]

We describe the isolation of Leishmania (Viannia) braziliensis from two female cats with American cutaneous leishmaniasis in Rio de Janeiro, Brazil. The isolates were identified as L. (V.) braziliensis by isoenzyme electrophoresis. [Copyright &y& Elsevier]