Flagellar biofilm in relation to flagellar gene for virulence of salmonellae in chicken

الملخص EN

The present study was conducted to determine the effect of Salmonella infection on 152 chicken samples of different ages in two seasons cold (winter and spring) and hot (summer and autumn) seasons at Dakahlia Governorate.

Chicken were examined clinically and postmortem and the samples were taken from livers, caecum, spleen and small intestine for Salmonella isolation.

S.

Typhimurium were examined for its ability to form biofilms on the wall of glass tubes and also Polymerase chain reac-tion (PCR) was used for detection of flagellar gene (flAg) of S.

Typhimurium which is an essential gene required for motility of Sal-monella.

Salmonellae were isolated from (27) out of (152) chickens that were examined (17.8 %) with high incidence during hot seasons (25 %) in contrast to cold seasons (10.5 %), the rate of recovery of Salmonellae from the different internal organs showed that the recovery rate was ; liver (12.5 %), caecum (8.55 %), spleen (7.24 %) and small intestine (3.29 %). Serotyping of isolates revealed that S.

Typhimurium represented 13.8 % (21 isolates) and S.

Kentucky 3.95 % (6 isolates) from the examined sam-ples, S.

Typhimurium and S.

Kentucky were isolated from liver while S.

Typhimurium is the only serovar which isolated from small intestine, caecum and spleen.

PCR-polyacrylamide gel electrophoresis detected flagellar gene of S.

Typhimurium with amplicon 375 bp and S.

Typhimurium had the ability to form biofilms on glass surface of the test tubes but, S.

Pullorum did not have the flagellar gene as non motile serotype (reference strain from Namiro Center in Egypt) so was not de-tected by PCR and this proved the relation between motility and biofilm formation.

Results of antibiotic sensitivity test of S.

Typhimurium and S.

Pullorum proved that there is no correlation between biofilm formation by flagellae and antibiotic susceptibility.