Poultry industry is playing central role in the economics of Pakistan. Unfortunately, many diseases
are continuous threat to this industry. One of the important disease is salmonellosis which is
zoonotic problem and leftovers among principal causes of food borne illness throughout world.
Salmonella Enterica serotype Gallinarum biotype Gallinarum is septicemic, acute, chronic and
systemic disease of birds and had given huge economic losses to the farmers. A poultry producer
suffers lose due to salmonella infection of the flock including loss of birds and production time.
So the exact and precise diagnosis of disease is most important.
A total of 150 samples were collected from six outbreaks of salmonellosis around Lahore
region on the basis of clinical signs and postmortem lesions. 25 samples from each outbreak were
collected in duplicates. One in polythene bag along with ice pack for bacteriology and second in
ten percent neutral buffered formalin for histopathology. These samples were transported to the
Department of Pathology, University of Veterinary and Animal Sciences Lahore, for further
processing. Pre-enrichment method was used to isolate bacteria. 24 gram affected organs (liver,
spleen, intestine, caeca, lungs, heart and kidney) were cut into very small pieces using sterile
scalpel blades and suspended into 250 ml sterile buffered peptone water and incubated for 18 hours
at 37°C. One mL of cultures was shifted to Selenite broth and incubated at 37°C for 24 hours. One
loopful from the Selenite broths was streaked onto plates of (SS) agar and incubated at 37°C for
24 hours. Whitish and slightly gray color colonies on SS agar, were observed. These colonies were
confirmed by morphologically biochemically and serologically. Colonies were considered positive
S. gallinarum when indole production, Voges-Proskauer, urease, motility, arginine and lactose
fermentation tests were negative and H2S production, methyl red, mannitol fermentation with no
Summary
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gas production, lysine, ornithine and Salmonella Polyvalent “O” antiserum agglutination tests were
positive. S. gallinarum was successfully recovered from organs including Liver, spleen, intestine,
caeca, lungs, heart and kidney. All the organs of positive samples did not give recovery of S.
gallinarum. Maximum recovery was obtained from liver. Majority of birds showed clinical sigs
anorexia, depression, high fever, watery bright yellow diarrhea, rapid respiration and pale and
shrunken comb. Bronze discoloration and necrotic foci on liver, congested and enlarged kidney,
enlarged spleen, edematous and congested lungs, degeneration in intestine and degeneration and
necrosis in caeca, were main gross lesions on internal organs. Microscopically liver showed
hepatic card necrosis. kidney showed interstitial nephritis, peritubular necrosis and congestion.
Intestinal caeca showed necrosis and degeneration. Intestinal mucosa showed degeneration.
Immunohistochemistry on S. gallinarum positive tissues were conducted and revealed localize
bacteria in tissues. In positive slides, dark stained areas showed immunoreaction between antigen
and antibody. These stained areas actually showed the position of pathogen. In present study S.
gallinarum was not isolated from all the birds showing clinical signs of disease and liver is the
only organ that gave highest recovery of S. gallinarum. So liver may be the target organ in this
disease. Furthermore, immunohistochemistry is precise and sensible technique to find out
pathogen.