RESUMO
Introduction: Universally, in microbiological diagnostics the detection of live bacteria is essential. Rapid identification of pathogens enables appropriate remedial measures to be taken. The identification of many bacteria simultaneously facilitates the determination of the characteristics of the accompanying microbiota and/or the microbiological complexity of a given environment. Material and Methods: The effectiveness of the VITEK2 Compact automated microbial identification system and matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS), analytical profile index (API) and Remel RapID tests were compared in identification of bacteria isolated from the alpaca gastrointestinal tract. Results: Most isolates were Gram-positive, such as Bacillus cereus, Bacillus flexus, Bacillus licheniformis, Bacillus pumilus and Bacillus subtilis; Enterococcus faecium, Enterococcus gallinarum, Enterococcus hirae and Enterococcus casseliflavus; Staphylococcus aureus, Staphylococcus equorum, Staphylococcus lentus, Staphylococcus pseudintermedius and Staphylococcus sciuri; Paenibacillus amylolyticus; Cellulosimicrobium cellulans; Leuconostoc mesenteroides; Clostridium perfringens; Corynebacterium stationis, Corynebacterium xerosis, and Corynebacterium diphtheriae (the last only isolated manually by API Coryne and the VITEK2 system and Corynebacteria (CBC) card). Corynebacterium diphtheriae was misidentified by MALDI-TOF MS as Candida lipolytica (currently Yarrowia lipolytica). Gram-positive and Gram-variable Micrococcus luteus were also isolated. Gram-negative Enterobacter cloacae, Enterobacter gergoviae, Enterobacter hormaechei and Enterobacter ludwigii; E. coli; Klebsiella pneumoniae subsp. pneumoniae; Citrobacter braakii and Citrobacter freundii; Serratia liquefaciens, Serratia odorifera and Serratia marcescens; Morganella morganii subsp. morganii; Providencia alcalifaciens; Pseudomonas aeruginosa; Stenotrophomonas maltophilia; Moraxella osloensis; and Ochrobactrum intermedium were also found. The yeasts Candida albicans, Candida haemulonii and Candida ciferrii were also present. Conclusion: MALDI-TOF MS enabled the identification of pathogens and opportunistic pathogens from the alpaca gut which may represent a high risk to human and animal health.
RESUMO
During embryonic development, hematopoietic cells are present in areas of blood-vessel differentiation. These hematopoietic cells emerge from a specific subpopulation of endothelial cells called the hemogenic endothelium. We have previously found that mouse proepicardium contained its own population of endothelial cells forming a network of vascular tubules. We hypothesize that this EC population contains cells of hematopoietic potential. Therefore, we investigated an in vitro hematopoietic potential of proepicardial cell populations. The CD31+/CD45-/CD71- cell population cultured for 10 days in MethocultTM gave numerous colonies of CFU-GEMM, CFU-GM, and CFU-E type. These colonies consisted of various cell types. Flk-1+/CD31-/CD45-/CD71-, and CD45+ and/or CD71+ cell populations produced CFU-GEMM and CFU-GM, or CFU-GM and CFU-E colonies, respectively. Immunohistochemical evaluations of smears prepared from colonies revealed the presence of cells of different hematopoietic lineages. These cells were characterized by labeling with various combinations of antibodies directed against CD31, CD41, CD71, c-kit, Mpl, Fli1, Gata-2, and Zeb1 markers. Furthermore, we found that proepicardium-specific marker WT1 co-localized with Runx1 and Zeb1 and that single endothelial cells bearing CD31 molecule expressed Runx1 in the proepicardial area of embryonic tissue sections. We have shown that cells of endothelial and/or hematopoietic phenotypes isolated from mouse proepicardium possess hematopoietic potential in vitro and in situ. These results are supported by RT-PCR analyses of proepicardial extract, which revealed the expression of mRNA for crucial regulatory factors for hemogenic endothelium specification, i.e., Runx1, Notch1, Gata2, and Sox17. Our data are in line with previous observation on hemangioblast derivation from the quail PE.