Studies on cellulitis and other disease syndromes caused by Escherichia coli in broilers in Sri Lanka

Cellulitis caused by Escherichia coli in broilers results in substantial lo sses to the broiler industry in North America and Europe due to condemnatio ns at slaughter. The objective of this study was to identify cellulitis in broilers in Sri Lanka and to characterize the E. coli from cellulitis and o ther colibacillosis lesions. Twenty-four farms from the low- and mid-countr y were selected and bacterial isolations were obtained from 241 birds. Two hundred and ninety-one gross lesions were observed in these 241 birds and 1 62 E. coli isolates were obtained. Cellulitis was observed in 21% of the bi rds. Twenty-one per cent of the birds had multiple lesions due to E. coli. The frequency of detection of other disease syndromes was 162 (67%) birds w ith pericarditis, 26 (11%) airsacculitis, 24 (10%) hepatitis, 12 (5%) perih epatitis, and 16 (7%) polyserositis (a combination of pericarditis, perihep atitis and airsacculitis). Serogroups O78, O2, O85 and O88 were distributed among the 32% of typable E. coli and 81% of isolates were assigned to thre e biotypes. Forty-four per cent of the E. coli isolates produced aerobactin and 88% demonstrated resistance to the bactericidal effect of normal chick en serum. The majority of the E. coli isolates were resistant to the antibi otics commonly used in poultry. All the E. coli isolates were non-haemolyti c and 25% of the isolates produced K1 capsule. This study demonstrated the presence of cellulitis in Sri Lanka and this report describes some of the p henotypic characteristics of the E. coli isolates.