ABSTRACT
The effect of subinhibitory concentrations of rifampicin, chloramphenicol, tetracycline and nalidixic acid on the interaction of Shigella flexneri 2a and Escherichia coli O124 with HeLa cells was examined. Antimicrobial agents altered adhesion, penetration and intracellular multiplication of the bacteria, as well as re-infection of adjacent cells. Chloramphenicol increased the virulence of the bacterial strains whereas nalidixic acid, tetracycline and rifampicin diminished it.
Subject(s)
Anti-Bacterial Agents/pharmacology , Escherichia coli/drug effects , Shigella flexneri/drug effects , Bacterial Adhesion/drug effects , Chloramphenicol/pharmacology , Escherichia coli/pathogenicity , HeLa Cells , Humans , Nalidixic Acid/pharmacology , Rifampin/pharmacology , Shigella flexneri/pathogenicity , Tetracycline/pharmacology , Virulence/drug effectsABSTRACT
The paper presents a review of foreign publications (35 references) regarding the history of isolation and investigation of one of the herpesviruses--a new lymphotropic human herpesvirus type 6 (HHV-6). The wide spread of the virus in the human population is demonstrated. Both patients with manifestative types of the disease and asymptomatic HHV-6 carriers are supposed to provoke the infection. The disease can be transmitted by the droplet and genital routes of infection, via hemotransplantation, and by the vertical transmission of the agent. HH-6 was found to play an etiological role in the development of sudden exanthema in early childhood.
Subject(s)
Herpesviridae Infections/epidemiology , Herpesvirus 6, Human , Adolescent , Adult , Age Factors , Child , Child, Preschool , Herpesviridae Infections/transmission , Herpesviridae Infections/virology , Humans , Infant , Infant, Newborn , Infectious Disease Transmission, Vertical , Middle Aged , Transfusion ReactionABSTRACT
The effect of subinhibitory concentrations of antimicrobial agents such as chloramphenicol, tetracycline, rifampicin and nalidixic acid on various factors of virulence in Shigella spp. and enteroinvasive colon bacilli was studied. It was shown that under such conditions changes took place in various events of the interaction with the epithelial cells, i.e. in adhesion, penetration, intracellular multiplication and transfers between contacting cells. The total effect of chloramphenicol resulted in increasing of the virulence while that of nalidixic acid, tetracycline and rifampicin resulted in its decreasing.
