RESUMO
Staphylococcus aureus NCTC 8325-4 and its eight variants lysogenized with phages responsible for the synthesis of staphylococcal staphylokinase were used for the study. Influence of phage conversion of S. aureus on its interaction with human leucocytes and influence of prophage on strain susceptibility to intracellular killing by human granulocytes without opsonins were evaluated. It was found that lysogenization of the strain with the bacteriophages decreased in each case reactivity of human leucocytes for staphylococcal strain what was expressed by lower bioluminescence values and by lower percentage of intracellular killing of bacterial cells carrying prophage.
Assuntos
Leucócitos/imunologia , Lisogenia/imunologia , Fagocitose/imunologia , Fagos de Staphylococcus/imunologia , Staphylococcus aureus/imunologia , Meios de Cultura , Humanos , Técnicas In Vitro , Lisogenia/genética , Fagos de Staphylococcus/genética , Staphylococcus aureus/genética , Staphylococcus aureus/crescimento & desenvolvimentoAssuntos
Campylobacter/isolamento & purificação , Dispepsia/microbiologia , Mucosa Gástrica/microbiologia , Úlcera Péptica/microbiologia , Adulto , Idoso , Infecções por Campylobacter/complicações , Dispepsia/etiologia , Feminino , Gastrite/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Úlcera Péptica/etiologiaAssuntos
Cromossomos Bacterianos , Infecção Hospitalar/microbiologia , Eritromicina/farmacologia , Genes Bacterianos/efeitos dos fármacos , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus/genética , Translocação Genética , Meios de Cultura , Resistência Microbiana a Medicamentos , Humanos , Técnicas In Vitro , Staphylococcus aureus/efeitos dos fármacosRESUMO
The localization of the coagulase gene in Staphylococcus aureus JM 750 strain was investigated. S. aureus JM 750 strain in contrast to other S. aureus strains shows instability of coagulase production. This strain contains the 23.5 kb penicillinase plasmid, determining beta-lactamase synthesis and resistance to heavy metal salts, and a larger plasmid greater than 100 kb in size, which was detectable only in coagulase positive variants. The results suggest the unparalleled, extrachromosomal localization of the coagulase gene in S. aureus JM 750 strain.
Assuntos
Coagulase/genética , Genes Bacterianos , Staphylococcus aureus/genética , Clonagem Molecular , Coagulase/biossíntese , DNA Bacteriano/análise , Temperatura Alta , Cinética , Penicilinase/genética , Fatores R , Staphylococcus aureus/enzimologia , Transdução Genética , beta-Lactamases/biossíntese , beta-Lactamases/genéticaRESUMO
pC658: a plasmid determining resistance to chloramphenicol in the hospital strain of Staphylococcus aureus JM658 was transduced after irradiation of phage lysate with high doses of UV. The localization of determinants causing resistance to chloramphenicol in the obtained transductants was investigated by modified Arber's method and variants resistant to chloramphenicol, but suspected of absence of chloramphenicolase plasmid were selected. Additionally the absence of plasmid DNA was demonstrated in the selected strains. The possibility of plasmid and chromosomal localization of the same gene indicates its translocable nature. The obtained results suggests transposomal character of the genes determining resistance to chloramphenicol in the pC658 plasmid, occurring in the hospital strain of S. aureus.
Assuntos
Cloranfenicol/farmacologia , Staphylococcus aureus/genética , Translocação Genética , Resistência Microbiana a Medicamentos , Fatores R , Especificidade da Espécie , Staphylococcus aureus/efeitos dos fármacosRESUMO
The chromosomal localization of fosfomycin resistance genes in three hospital Staphylococcus aureus strains and in the standard strain NCTC 8507 was shown. Moreover, the chromosomal locus of the gene determining resistance to three aminocyclitol antibiotics: gentamycin, kanamycin and tobramycin in the one of hospital strains was determined. The possibility of transducing this resistance and the absence of plasmid DNA in the obtained transductants, suggest transposomal nature of the gene determining gentamycin, kanamycin and tobramycin resistance in the investigated strain.
Assuntos
Antibacterianos/farmacologia , Cromossomos Bacterianos , Fosfomicina/farmacologia , Staphylococcus aureus/genética , Mapeamento Cromossômico , Elementos de DNA Transponíveis , DNA Bacteriano , Resistência Microbiana a Medicamentos , Genes Bacterianos , Marcadores Genéticos , Gentamicinas/farmacologia , Canamicina/farmacologia , Plasmídeos , Staphylococcus aureus/efeitos dos fármacos , Tobramicina/farmacologia , Transdução GenéticaRESUMO
EcoRI fragments of Aspergillus nidulans DNA were cloned in a shotgun type experiment using the EK2 vector lambda gtWEST.T5-622. In situ plaque hybridization was used to screen for hybrid phage particles containing sequences coding for ribosomal RNA. Four clones selected from the whole gene bank were characterized further. Two of them contain sequences homologous to a 3.6 Kb fragment of A. nidulans rDNA.
Assuntos
Aspergillus nidulans/genética , Bacteriófago lambda/genética , Clonagem Molecular , DNA Fúngico/genética , DNA Recombinante , DNA/metabolismo , Ribossomos/metabolismo , Aspergillus nidulans/ultraestrutura , DNA Ribossômico , Escherichia coli/genética , Hibridização Genética , Técnicas In VitroRESUMO
A genetic analysis of multiply inorganic salts and antibiotic--resistant strains of Staphylococcus aureus was performed. Experiments designed to show reversion of organisms to antibiotic and inorganic salt susceptibility, as well as studies on the influence of ultraviolet irradiation of phage on the transduction frequencies of the resistance markers, indicated that determinants of chloramphenicol, tetracycline, aminoglycoside antibiotics, inorganic salts, and penicillin resistance in hospital strain are present on separate plasmids. Transduced by us plasmids pN742 and pN794 determined resistance to neomycin, kanamycin, paromomycin, lividomycin and streptomycin.
