|WALTMAN, W - Georgia Poultry Laboratory Network|
Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 2/18/2016
Publication Date: 7/7/2016
Citation: Waltman, W. Douglas and Richard K. Gast, 2016. Salmonella enterica. In Isolation and Identification of Avian Pathogens, 6th edition, S. M. Williams, L. Dufour-Zavala, M. W. Jackwood, M. D. Lee, B. Lupiani, W. M. Reed, E. Spackman, and P. R. Woolcock, eds.American Association of Avian Pathologists, Athens, GA. pp. 103-112.
Technical Abstract: Avian Salmonella infections are important as both a cause of clinical disease in poultry and as a source of food-borne transmission of disease to humans. Host-adapted salmonellae (Salmonella enterica serovar Pullorum and Gallinarum) are responsible for severe systemic diseases, whereas numerous serotypes of non-host-adapted paratyphoid salmonellae are often carried subclinically by poultry and thereby may contaminate poultry products. Crowding, malnutrition, and other stressful conditions as well as unsanitary surroundings can exacerbate mortality and performance losses due to salmonellosis, especially in young birds. Salmonella infections in poultry flocks are diagnosed principally by the isolation of the bacteria from clinical tissue samples, such as pooled internal organs and sections of the intestinal tract. Egg contents may also be cultured to detect Salmonella enterica serovar Enteritidis. Preliminary identification of infected or colonized flocks is often obtained by culturing poultry house or hatchery environmental samples, such as drag swabs/boot swabs, litter, dust, feed, and hatch residue. Clinical and environmental samples are generally subjected to selective enrichment, with nonselective pre-enrichment sometimes employed when salmonellae are present in very small numbers or are potentially injured. Delayed secondary enrichment often improves Salmonella recovery from tissue samples. Samples are plated on selective agar and bacterial colonies are identified as Salmonella by further biochemical and serological testing. Serologic identification of infected poultry plays an important role in programs for controlling the spread of Salmonella in commercial flocks, especially in regard to S. Pullorum and S. Gallinarum. Agglutination tests, particularly the rapid whole-blood plate test, are used for verification of the Salmonella status of flocks participating in the National Poultry Improvement Plan.