EVALUATION OF SEF14 FIMBRIAL DOT-BLOT AND FLAGELLAR WESTERN-BLOT TESTS AS INDICATORS OF SALMONELLA-ENTERITIDIS INFECTION IN CHICKENS

The serological responses to Salmonella enteritidis flagella (H: g,m) and its fimbrial antigen SEF14 were evaluated as indicators of infecti on in chickens and to confirm serological results obtained by an ELISA using S enteritidis lipopolysaccharide (LPS) (0: 9, 12) as the detect ing antigen, The SEF14 antigen and flagella were extracted from S ente ritidis and transferred to nitrocellulose paper for use in Western and dot blot tests. Antisera to 19 salmonella serotypes including S enter itidis were raised in rabbits and their cross reactivity to the flagel lar and SEF14 antigens was evaluated, Cross reactivity with the SEFM a ntigen was found in one antiserum, raised against S blegdam, and to fl agella in eight of 19 antisera raised against various salmonella serot ypes, most of which shared the flagellar factors g or m with S enterit idis. The intensity of cross reaction to flagella was strongest in S d erby and S blegdam antisera. Antisera raised in chickens against S typ himurium and S panama did not cross react in either test, and neither did pooled sera from eight-week-old salmonella-free, broiler breeder p arent chickens. Field sera from two commercial necks with no history o f salmonella infection were negative when tested by the LPS ELISA. The se sera were also negative when tested by the flagellar and SEF14 blot s, S enteritidis infection in a commercial laying flock was detected i nitially when the sera were tested by the LPS ELISA and confirmed in i ndividual and pooled sera by the SEF14 and flagellar tests. S enteriti dis PT4 was isolated from this flock post mortem.