Salmonella carrier state and biological characteristics of the infectious agent.

Salmonella carrier state (42.6%-S. enteritidis and 34.4%-S. dublin) was demonstrated in subjects after acute salmonellosis as well as in healthy persons infected with salmonella as a result of occupational exposure to poultry (8.8% in humans exposed to chickens and 6.1% in those exposed to ducks) and sheep (2.8%). The carrier state was accompanied by intermittent pain in the epigastrium, diminished appetite, diarrhoea etc. Most of the carrier subjects with a history of salmonellosis exhibited, upon rectoromanoscopy, a varying degree of proctosigmoiditsi. The etiological role of S. typhimurium was proved beyond doubt, as well as its ability to cause salmonellosis outbursts, sporadic cases of the disease and the carrier state. When large industrial facilities specializing in poultry processing were investigated, the salmonella carrier state was revealed in practically healthy poultry--in 16% of chickens and 12% of ducks. The salmonella organisms isolated from carrier persons had, with some exceptions, typical properties, being virulent in that they caused death of experimental animals, seeded their internal organs and induced pathogenicity-associated enzymes. Multiple resistance to antibiotics was demonstrated in salmonella isolated from poultry; also determined was its plasmid nature. Pronounced resistance of the above salmonella subtypes to tetracycline-related antibiotics and streptomycin may be due to the fact that these drugs are used in poultry raising.