Dijagnostički postupci za razlikovanje vakcinalnog i terenskog soja Salmonele

Abstract

Control of the occurrence and spread of infectious diseases can be implemented in different ways. In addition to zootechnical and hygienic measures, which are the basic methods in preventing the outbreak of diseases caused by infectious agents, immunoprophylaxis is a qualitatively special way of limiting the spread of infection. It allows the creation of protection against a specific microorganism. Salmonellosis is an infectious disease caused by bacteria from the genus Salmonella, but in relation to humans, in animals, it almost never or rarely leads to clinically manifested forms of the disease. Creating an immune response to strains of live vaccines that are widely used in poultry can lead to diagnostic problems when a differential, laboratory finding requires a distinction between the field and vaccinal strains. In order to allow the differentiation of vaccine from field isolates, vaccine manufacturers prescribe methods for establishing a precise laboratory differential diagnosis. In our work we have analysed the methods of differential diagnosing of vaccine and field strains, with the aim of recommending an optimal method, from an economic and practical aspect. Monitoring the period of excretion of vaccine strain, sensitivity and/or resistance to particular antimicrobial drugs, molecular methods and determination of specific phenotypic i.e. biochemical characteristics of vaccinal strains are part of laboratory procedures that enable differential diagnosis. In laboratory conditions, the methods of monitoring the resistance/sensitivity of isolated strains of Salmonella Enteritidis toward some antimicrobial drugs and the confirmation of particular biochemical characteristics of the vaccine strain proved to be the most acceptable procedure for distinguishing field from vaccinal isolates.