Cellulitis in poultry

Cellulitis is an acute and diffuse suppurative inflamation, affecting all subcutaneous tissues and in certain instances the muscular tissue as well. It is frequently associated to abscess formation. In birds, cellulitis causes discoloration and thickening of the skin, hence, it is also known as an inflamatory process, or necrotic dermatitis (Norton, 1997).
In recent years, the interest in the study of avian cellulitis has increased. This is mainly due to the great losses associated with the number of birds discarded at slaughter because of skin lesions. It is considered that, in Brazil, yearly losses surpass 40 millon USD (Brito et al., 2003). The objective of this work was to determine the etiology of the lesions of cellulitis in chicken.

Forty lesions of cellulities in broilers coming  from 28 poultry farms of the state of Paraná, Brazi, were selected at the abattoir. Microorganisms were isolated from the cellulitis lesions by means of a sterile swab. Next, the swab was seeded in blood agar and Mac Conkey agar, during 18 hours at 37º C. Growth aspects, morphological and staining characteristics using the Gram technique and biochemical tests according to Cowan and Steel (1970) and Edward and Ewings (1972), were used for bacterial identification. For the mycologic examination, samples were cultured in Sabouraud agar, at ambient temperature during 21 days for further identification.

Table 1, presents the results of the microbiological analysis of cellulitis lesions. Forty samples from 28 farms were considered. Escherichia coli was the most isolated bacteria (96,43%), followed, in a lesseser percent by Citrobacter sp (10,71%), Proteus vulgaris (7,14%), Staphylococcus sp (3,57%), Streptococcus sp (3,57%), Candida albicans (3,57%), Pseudomonas aeruginosa (3,57%), Klebsiella sp (3,57%), Serratia sp (3,57%), Penicillium sp (3,57%) and Aspergillus sp (3,57). Data obtained in this work, agree with those of Messier et al. (1993) who also stated the prevailance of Escherichia coli in lesions of cellulitis. Besides Escherichia coli, several researchers have identified other organisms present in lesions of cellulitis. Norton et al. (1999) quote Enterobacter agglomerans, Pasteurella multocida, Proteus vulgaris, Pseudomonas aeruginosa and Streptococcus dysgalactiae.

Table 1. Frequency of isolated microorganisms of lesions of cellulitis in broilers of 28 farms, at slaughter.

We concluded that in lesions of cellulitis in chickens at the abattoir, Escherichia coli is the most frequently found bacteria, alone or in association with other  microorganisms.

Brito BG; Gaziri LCJ; Vidotto, MC. 2003. Virulence factors and clonal relationships among Escherichia coli strains isolated from broiler chickens with cellulitis. Infect. Immun. 71(7):4175-4177.

Cowan ST & Steel KJ. 1970. Manual for the identification of medical bactéria. Cambridge, Cambridge University.

Edward PR & Ewings WH. 1972. Identification of Enterobacteriacea. Minneapolis, Burgess Publishers.

Messier S; Quessy S; Robinson Y; Devriesse LA; Hommez J; Fairbrother, JM. 1993. Focal dermatitis and celullitis in broiler chickens: bacteriological and pathological findings. Avian Dis. 37:839-844.

Norton RA. 1997. Avian cellulitis. World's Pout. Sci. J. 53:337-349.