Molecular Analysis of Three Aeromonas hydrophila AH-3 (Serotype O34) Lipopolysaccharide Core Biosynthesis Gene Clusters▿ †

By the isolation of three different Aeromonas hydrophila strain AH-3 (serotype O34) mutants with an altered lipopolysaccharide (LPS) migration in gels, three genomic regions encompassing LPS core biosynthesis genes were identified and characterized. When possible, mutants were constructed using each gene from the three regions, containing seven, four, and two genes (regions 1 to 3, respectively). The mutant LPS core structures were elucidated by using mass spectrometry, methylation analysis, and comparison with the full core structure of an O-antigen-lacking AH-3 mutant previously established by us. Combining the gene sequence and complementation test data with the structural data and phenotypic characterization of the mutant LPSs enabled a presumptive assignment of all LPS core biosynthesis gene functions in A. hydrophila AH-3. The three regions and the genes contained are in complete agreement with the recently sequenced genome of A. hydrophila ATCC 7966. The functions of the A. hydrophila genes waaC in region 3 and waaF in region 2 were completely established, allowing the genome annotations of the two heptosyl transferase products not previously assigned. Having the functions of all genes involved with the LPS core biosynthesis and most corresponding single-gene mutants now allows experimental work on the role of the LPS core in the virulence of A. hydrophila

MAIN AGENTS OF OPPORTUNISTIC INFECTIONS OF GENITOURINARY TRACTS AND THEIR ANTIBIOTIC RESISTANCE

Today the one of most important medical-social problems is a growing antibiotic resistance of opportunistic infectious agents.Aim of research: the dynamic observance of antibiotic resistance of opportunistic pathogens – infectious agents of genitourinary tracts under conditions of venereological clinic.The study included 2205 patients with inflammatory diseases of genitourinary tract, who were on the stationary treatment at the department of venereology of SI “IDV NAMS of Ukraine”. Bacteriological studies for isolation of conventionally pathogenic microorganisms with determination of sensitivity of separated laboratory strains to antibacterial drugs of the different groups were carried out using the methods of classic bacteriology.It was demonstrated, that the composition of microbiocenosis of genitourinary tract in patients with infections, caused by conventionally pathogenic microorganisms was characterized by the prevalence of aerobic representatives of Enterobacteriaceae and Staphylococcaceae families that formed associations both between each other and with representatives of other taxonomic groups. The analysis of antibiotic sensitivity of separated strains testifies to the necessity of permanent microbiological monitoring of opportunistic infectious agents for elaborations of the regimes of rational antibacterial therapy