Antimicrobial Resistance and Molecular Characterization of Extended-Spectrum ß-Lactamases of Escherichia coli and Klebsiella spp. Isolates from Urinary Tract Infections in Southern Brazil.

The objective of this study was to evaluate the frequency of different extended-spectrum ß-lactamases (ESBL) as well as to associate these ESBL with antimicrobial (ATM) resistance in Escherichia coli and Klebsiella spp. isolates from outpatients and inpatients with urinary tract infections. The study included 435 consecutive nonduplicate clinical isolates, including 362 E. coli isolates, 62 Klebsiella pneumoniae isolates, and 11 K. oxytoca isolates. Isolates were obtained from patients who were treated in a University Hospital between August 2012 and July 2013. Three multiplex PCR were performed to identify the ESBL groups. A total of 48 (11%) ESBL-producing isolates were found. The risk for the ESBL presence was significantly higher in males (26.4%) than females (8%), from hospital-acquired infections (29.1%) than community-acquired infections (7.0%) and in Klebsiella spp. (27.4%) than in E. coli (7.7%). ESBL-producing isolates presented a significantly higher percentage of resistance in 21 of the 23 ATMs analyzed. The CTX-M-1 group was the most predominant ESBL identified. The blaCTX-M-1-group gene was found in 56% of the total ESBL producers from community and in 42.4% from hospital origins; it was followed in frequency by the blaCTX-M-8/25-group, also found in both environments. Klebsiella spp. presented the largest variety of ß-lactamase enzyme combinations and a higher level of resistance to cefotaxime. These findings contribute to better knowledge of the epidemiology of ESBL enzymes and are alarming for the reduced therapeutic options available for the risk groups identified in the studied populations.

Lectin I from Bauhinia variegata (BVL-I) expressed by Pichia pastoris inhibits initial adhesion of oral bacteria in vitro.

Lectins are non-immune proteins that reversibly bind to carbohydrates in a specific manner. Bauhinia variegata lectin I (BVL-I) is a Gal/GalNAc-specific, single-chain lectin isolated from Bauhinia variegata seeds that has been implicated in the inhibition of bacterial adhesion and the healing of damaged skin. Since the source of the native protein (nBVL) is limited, this study aimed to produce recombinant BVL-I in Pichia pastoris (rBVL-Ip). The coding sequence for BVL-I containing preferential codons for P. pastoris was cloned into the pPICZαB plasmid. A single expressing clone was selected and fermented, resulting in the secretion and glycosylation of the protein. Fed-batch fermentation in 7L-scale was performed, and the recombinant lectin was purified from culture supernatant, resulting in a yield of 1.5mg/L culture. Further, rBVL-Ip was compared to nBVL and its recombinant version expressed in Escherichia coli BL21 (DE3) (rBVL-Ie). Although it was expressed as a monomer, rBVL-Ip retained its biological activity since it was able to impair the initial adhesion of Streptococcus mutans and S. sanguinis in an in vitro model of biofilm formation and bacterial adhesion. In summary, rBVL-Ip produced in Pichia pastoris represents a viable alternative to large-scale production, encouraging further biological application studies with this lectin.

Cell differentiation and the multiple drug resistance phenotype in human erythroleukemic cells.

The gene expression of Oct-4, a transcription factor and hematopoietic stem cell marker, is higher in Lucena lines, which is MDR, and the gene Alox-5 has also been implicated in the differentiation of some cell lines. The aim of this study was to compare the response to PMA-induced differentiation in MDR and non-MDR cells. We observed the differentiation to megakaryocytes in the K562 cell line, which is non-MDR. The expression of Alox-5 and Nanog genes was downregulated and that of Mdr-1 was upregulated in K562 cells. The Lucena cell line contained a higher number of megakaryocytes than the non-MDR, but this number was not altered by PMA, as well as Mdr-1 gene expression. However, Alox-5 expression was downregulated. Alox-5, Mdr-1, Nanog, Oct-4 and Sox-2 basal expression was also evaluated in the K562, Lucena and FEPS (also MDR) cell lines. The transcription factors gene expression was similar in MDR cell lines. The expression of Alox-5 was higher in the non-MDR cell line, while FEPS had the lowest expression of this gene. The opposite pattern was observed for Mdr-1 gene expression. These results suggest that the Alox-5 gene might play a role in the differentiation of these cell lines.

Assessment of plant lectin antifungal potential against yeasts of major importance in medical mycology.

The search for new compounds with antifungal activity is accelerating due to rising yeast and fungal resistance to commonly prescribed drugs. Among the molecules being investigated, plant lectins can be highlighted. The present work shows the potential of six plant lectins which were tested in vitro against yeasts of medical importance, Candida albicans, Candida tropicalis, Candida parapsilosis, Cryptococcus gattii, Cryptococcus neoformans, Malassezia pachydermatis, Rhodotorula sp. and Trichosporon sp. Broth microdilution susceptibility testing was performed in accordance with standard protocols to evaluate antifungal activity. Minimum inhibitory concentration (MIC) was determined at 80% yeast growth inhibition, whereas the minimum fungicidal concentration (MFC) was evaluated after making the subcultures of each dilution. Only C. parapsilosis growth was inhibited by the lectins tested. Abelmoschus esculentus lectin showed the highest MIC (0.97 µg ml(-1)). Lectins from Canavalia brasiliensis, Mucuna pruriens and Clitoria fairchildiana presented the highest MFC at (3.90 µg ml(-1)). These results encourage further studies with wider yeast strain selections, and open new perspectives for the development of pharmacological molecules.

Microalbuminúria: aviso de alerta às nefropatias diabéticas / Microalbuminuria: notice of alert to diabetics nephropathies

A microalbuminúria foi inicialmente detectada na urina de pacientes diabéticos tipo 1 e foi definida como a excreção subclínica de albumina na urina que não é detectada pelo métodos convencionais. O objetivo desse trabalho foi comparar pacientes diabéticos com não diabéticos relacionando a microalbuminúria, creatinina urinária e relação microalbuminúria/creatinúria. Foram analisados 50 pacientes sendo 12 diabéticos e 18 não diabéticos provenientes da cidade de Caçapava do Sul no Rio Grande do Sul. Eles foram analisados em um laboratório local, assinaram um termo de consentimento livre e esclarecido e preeencheram uma ficha contendo um questionário investigativo fechado. Para a estatística foi utilizado o teste t de Student e a correlação de Pearson, sendo utilizado p<0,05 como indice de significância. Não houve diferença estatistica entre os grupos quanto à creatinina urinária (p=0,25). Entretanto, o índice de massa corporal foi maior no grupo de pacientes diabéticos (p=0,001). A microalbuminúria foi maior nos pacientes diabéticos (p=0,013). A correlação de Pearson entre o tempo de diabetes e a relação microalbuminúria/creatinúria foi fraca (r+0,0099). Assim, concluimos que o monitoramento da microalbuminúria e a resução do índice de massa corporal têm papel importante no prognóstico de doença microvascular.