RESUMEN
OBJECTIVES: The present study reports the draft genome sequence of Staphylococcus aureus 4181, a strain involved in bovine mastitis that produces aureocin 4181, a broad-spectrum antimicrobial peptide (AMP). Inhibition of multidrug-resistant (MDR) staphylococci involved in human infections by S. aureus 4181 was also investigated. METHODS: A sequencing library was constructed using a Nextera XT DNA Library Preparation Kit (Illumina). Whole-genome shotgun sequencing was performed using an Illumina MiSeq System. The A5-miseq pipeline was employed for de novo genome assembly. Genome annotation was performed by the RAST server. The online automated tools BAGEL4 and antiSMASH v.5.0 were used for mining gene clusters encoding AMP production. The virulence potential of the strain was investigated employing online tools. Its inhibitory activity toward MDR staphylococcal isolates associated with human infections was tested by the deferred antagonism assay on brain-heart infusion agar medium. RESULTS: The total scaffold size was determined to be 2 719 949 bp, with a G + C content of 32.7%. Genome analyses revealed 2504 protein-coding sequences and 74 RNA-coding sequences as well as several genes encoding drug resistance and a single AMP gene cluster coding for aureocin 4181. Staphylococcus aureus 4181 exhibited a pathogenic potential and inhibited all MDR staphylococcal isolates tested as a target. CONCLUSIONS: This study describes the main features of the draft genome of S. aureus 4181, a strain that produces the third four-component bacteriocin described in the literature, namely aureocin 4181. This bacteriocin is a potential alternative drug to control MDR staphylococcal isolates involved in human infections.
Asunto(s)
Bacteriocinas , Infecciones Estafilocócicas , Animales , Bovinos , Femenino , Humanos , Proteínas Citotóxicas Formadoras de Poros , Staphylococcus/genética , Staphylococcus aureus/genéticaRESUMEN
BACKGROUND: The use of agro-industrial wastes to produce high value-added biomolecules such as biosurfactants is a promising approach for lowering the total costs of production. This study aimed to produce biosurfactants using Rhizopus arrhizus UCP 1607, with crude glycerol (CG) and corn steep liquor (CSL) as substrates. In addition, the biomolecule was characterized, and its efficiency in removing petroderivatives from marine soil was investigated. RESULTS: A 22 factorial design was applied, and the best condition for producing the biosurfactant was determined in assay 4 (3% CG and 5% CSL). The biosurfactant reduced the surface tension of water from 72 to 28.8 mN/m and produced a yield of 1.74 g/L. The preliminary biochemical characterization showed that the biosurfactant consisted of proteins (38.0%), carbohydrates (35.4%), and lipids (5.5%). The compounds presented an anionic character, nontoxicity, and great stability for all conditions tested. The biomolecule displayed great ability in dispersing hydrophobic substrates in water, thereby resulting in 53.4 cm2 ODA. The best efficiency of the biosurfactant in removing the pollutant diesel oil from marine soil was 79.4%. CONCLUSIONS: This study demonstrated the ability of R. arrhizus UCP1607 to produce a low-cost biosurfactant characterized as a glycoprotein and its potential use in the bioremediation of the hydrophobic diesel oil pollutant in marine soil
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Rhizopus/metabolismo , Tensoactivos/metabolismo , Gasolina , Suelo , Tensoactivos/toxicidad , Tensión Superficial , Biodegradación Ambiental , Ambiente Marino , Zea mays , Agroindustria , Interacciones Hidrofóbicas e Hidrofílicas , Glicerol , Residuos Industriales , Micelas , Mucorales/metabolismoRESUMEN
Neuraminidase (NA) of influenza A (H3N2) viruses was characterized after purification by gel filtration and proteolytic treatment, using the X-31 variant strain that is a reassortment between the influenza A/Victoria/3/75 (responsible for the 1975 pandemic) and the influenza A/PR/8/34 virus samples, as a model. In the purification process, NA heads, that is the spike responsible for the virus sialidase activity, were purified by filtration through a Bio-Gel polyacrylamide column. The enzyme activity was determined by periodic acid/thiobarbituric acid assay and high-performance thin-layer chromatography. The sialidase showed preference for the alpha-2,3-linkage over the alpha-2,6-linkage of sialyllactoses (K(m) of 1.8 and 5.2 x 10(-4)M, respectively) at pH 5.2. The enzyme acted on natural and synthetic substrates at different hydrolysis rates, as well as on human erythrocytes (A group, Rh+) and yeast (CANDIDA ALBICANS) cells. The active NA produced by gel filtration was characterized by different parameters of its sialidase activity, also showing to be a suitable tool for the identification of natural sialocompounds and for the screening of antisialidase drugs to treat influenza virus infections.
Asunto(s)
Subtipo H3N2 del Virus de la Influenza A , Virus de la Influenza A/enzimología , Neuraminidasa/metabolismo , Cromatografía en Gel , Cristalización , Humanos , Técnicas In Vitro , Virus de la Influenza A/clasificación , Virus de la Influenza A/aislamiento & purificación , Cinética , Peso Molecular , Neuraminidasa/química , Neuraminidasa/aislamiento & purificación , Pronasa , Estructura Cuaternaria de Proteína , Especificidad de la Especie , Especificidad por SustratoRESUMEN
The sialoglycoprotein profiles of five plant trypanosomatids (Phytomonas spp.) and of one flagellate (Herpetomonas sp.) isolated from the salivary gland of a phytophagous insect (Phthia picta) were analyzed by Western blotting using three distinct lectins (LFA, SNA and MAA), which recognize specifically sialic acid residues in glycoconjugates. All six flagellates presented at least one polypeptide recognized by the lectins, with the exception of Phytomonas françai, which did not show any reactivity with SNA agglutinin. Phytomonas serpens and P. françai showed the most distinct pattern of sialoglycoproteins. Phytomonas mcgheei, Herpetomonas sp. and the two other Phytomonas spp., isolated from latex, displayed an identical sialomolecule profile. We discuss the possible role of the sialoglycoproteins in the physiology of these trypanosomatids.