Alkyl Sulfatase of Cholera Vibrios

The aim of the work was to study the structure of the alkyl sulfatase (asu) gene in Vibrio cholerae strains of various serogroups, as well as to compare nucleotide and amino acid sequences of alkyl sulfatases using various methods of bioinformatic analysis.Materials and methods. 483 strains of V. cholerae O1, O139 and nonO1/nonO139 serogroups were employed in the work. The search for the gene, its recurrence, and localization was carried out applying the Blast software. The nucleotide and corresponding amino acid sequences of the gene, as well as its structure, were studied using bioinformatic analysis. Sequencing was performed on the MiSeq (Illumina) platform. The enzymatic activity was detected using a medium, confirming the presence/absence of the gene by PCR in vitro and in silico.Results and discussion. Bioinformatic analysis of the nucleotide and corresponding amino acid sequences of the asu gene has been carried out and its structure investigated. Four functional domains have been identified. In the beta-lactamase domain, a conservative amino acid sequence -HAHADH- has been found in all strains of cholera vibrios, which is part of the Zn2+ binding motif. It has been established that the alkyl sulfatase of cholera vibrios belongs to the family of Zn2+-dependent β-lactamases. Blast analysis has revealed the similarity of nucleotide and amino acid sequences of alkyl sulfatases in representatives of V. cholerae O1 and O139 serogroups (ctxAB+tcpA+) and representatives of the genera Aeromonas and Pseudomonas, which is in the line with the data of 3D modeling of the amino acid sequence structures of the alkyl sulfatase enzyme in these microorganisms. The bioinformatic analysis of nucleotide and amino acid sequences of alkyl sulfatases in cholera vibrios has showed the conservativeness of these sequences in toxigenic strains and the presence of a number of single mutations in the asu gene in atoxigenic ones. The presence or absence of the asu gene has been established by PCR in vitro and in silico and confirmed by the results obtained using the Blast program. It is demonstrated that the presence/absence of the asu gene correlates with the ability/inability of O139 strains to hydrolyze SDS on the medium. These results can be used in studying mechanisms of cholera vibrios adaptation, persistence and pathogenicity

Changing the spectrum of fatty acids as one of the mechanisms of adaptation/persistence of microorganisms

The review presents the basic information available in the literature on changes in the composition of fatty acids in various microorganisms in response to various environmental factors (stressors). The issues affecting the importance of fatty acids as biomarkers of pathogenetic and adaptive-persistent potential of bacteria are discussed. The prospects of studying the spectrum of fatty acids in the field of biochemistry, in particular, lipidomics of infectious diseases are noted

Cholera Vibrio Membrane Protein <I>OmpT</I> as an Omptin Belonging to <I>Vibrionaceae</I> Family

Concerned are the issues related to enterobacteria omptins, their structure and functionality, as well as alternative role in pathogenesis of the infections induced by them. Isolated from cholera vibrio, and later purified using differential centrifugation and column chromatography has been porin protein of the OmpT outer membranes, with the molar mass of approximately 40 kDa. Synthesis of porin is under control of the complex regulatory system. It does not contain cysteine, but possesses proteolytic activity with broad substrate specificity: it hydrolyzes fibrin, protamin, gelatine; transduces human plasminogen into plasmin, which provides for the well-known advantages for the vibrios in the intestine of a susceptible host. Comparative computer-assisted analysis of amino acid sequence has revealed that cholera vibrio OmpT protein relates to the omptins of enterobacteria as a far-remotely one, and has 13 % identity and similarity to it. OmpT protein is probably affiliated to a new class of porins of the family Vibrionaceae

USE OF VIBRIO CHOLERAE SURFACE STRUCTURES FOR SPECIFIC PROPHYLAXIS AND DIAGNOSTICS OF CHOLERA

The need for efficient and cost-effective cholera vaccine hasn’t lost its actuality in view of the emergence of new strains leading to severe clinical forms of cholera and capable to replace strains of the seventh cholera pandemic, and in connection with the threat of cholera spreading beyond the borders of endemic countries. In this review data from literature sources are presented about the use of outer membrane proteins, vesicles, cell ghosts of the cholera causative agent in specific prophylaxis and diagnostics of the disease