title: Biochemical, immunochemical and immunobiological properties of a chloramphenicol-resistant Salmonella typhi strain isolated in Mexico.
abstract: The authors have compared the biochemical, immunochemical and immunobiological properties of a chloramphenicol-resistant S. typhi strain isolated during the typhoid fever epidemic in Mexico of 1972 and those of a chloramphenicol-sensitive strain (S. typhi Ty2). They have found no difference in the chemical composition of the two strains. The immunobiological investigations have shown, that the chloramphenicol-resistant strain contains less Vi antigen, it is less virulent on mice, and its active and passive mouse-protective ability is lower than that of the chloramphenicol-sensitive S. typhi Ty2 strain. These findings supported by the result of the electrophoretic analysis suggest that the chloramphenicol-resistant strain is a VW strain, while the chloramphenicol-sensitive strain is a full V strain; the quantitative difference found between the immunogenicity of the two strains to the advantage of the chloramphenicol-sensitive strain may probably be explained by this fact. On the basis of their immunological investigations the authors are of the opinion, that vaccines prepared from chloramphenicol-sensitive S. typhi strains (provided these are full V strains, as e.g. the S. typhi Ty2 strain) will protect most likely also man against infection due to chloramphenicol-resistant S. typhi strains.
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000942:Antigens, Bacterial / Q000032:analysis; D002701:Chloramphenicol / Q000494:pharmacology*; D004352:Drug Resistance, Microbial; D005260:Female; D005285:Fermentation; D006601:Hexoses / Q000032:analysis; D008297:Male; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012485:Salmonella typhi / Q000032:analysis / Q000187:drug effects* / Q000276:immunology; D014435:Typhoid Fever / Q000517:prevention & control; D014436:Typhoid-Paratyphoid Vaccines / Q000494:pharmacology / Q000633:toxicity; D014774:Virulence
chemical_list: D000900:Anti-Bacterial Agents; D000942:Antigens, Bacterial; D006601:Hexoses; D014436:Typhoid-Paratyphoid Vaccines; D010758:Phosphorus; D002701:Chloramphenicol; D009584:Nitrogen