RESUMO
The Curtobacterium genus is a member of the family Microbacteriaceae, and Curtobacterium species are recognized as plant pathogens. The aim of this study was to investigate a dubious result of species identification for an infection located on a catheter tip of a patient with Covid-19. A strain isolated from a catheter tip sample, identified by VITEK® 2 as Cronobacter spp., was submitted to polyphasic analysis: Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry (MALDI-TOF MS) using VITEK® MS, real-time polymerase chain reaction targeting dnaG gene, and 16S rRNA full gene Sanger sequencing analysis for confirmation. The strain presented negative result using qPCR and could not identified by MALDI-TOF MS. 16S rRNA full gene Sanger sequencing analysis identified the strain as Curtobacterium spp. The Gram-variable characteristic (Gram-negative instead of Gram-positive) of the isolated strain was the responsible for the misidentification by VITEK® 2 and VITEK® MS did not identify the strain. 16S rRNA full gene sequencing analysis identified the strain as Curtobacterium genus, but other complementary techniques are necessary to identify at species level.
Assuntos
Actinomycetales , COVID-19 , Cronobacter , Actinomycetales/genética , Técnicas de Tipagem Bacteriana/métodos , Catéteres , Humanos , RNA Ribossômico 16S/genética , Análise de Sequência de DNA , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz/métodosRESUMO
1. Feathers are recalcitrant protein-rich wastes produced in huge amounts by poultry processing for meat production. Hence, feather bioconversion and protease production by Bacillus sp. CL18 were investigated. 2. Bacillus sp. CL18 demonstrated a remarkable feather-degrading potential. Through cultivations on feather broth (10 g l-1 feathers), 94.5% ± 3% of whole feathers were degraded after 4 d. Increases in soluble protein contents were observed and protease production was maximal also at d 4. This strain produced diverse proteolytic enzymes during growth. 3. Crude protease displayed optimal activity at 55°C (50-62°C), pH 8.0 (7.0-9.0) and a low thermal stability. Proteolytic activity increased in the presence of Ca2+, Mg2+, Triton X-100, Tween 20 and dimethyl sulphoxide. Inhibition profile indicated that crude protease contains, mainly, serine proteases. Enzyme preparation hydrolysed mainly casein and soy protein isolate. 4. The keratinolytic capacity of Bacillus sp. CL18 at moderate temperatures (30°C) might be appropriate for feather conversion, resulting in protein hydrolysates and proteolytic enzymes. Proteases are postulated to be added-value products that can be obtained from such a bioprocess.