No abstract

A Mycoplasma synoviae (MS)-free flock of broiler breeders was housed for brooding and rearing on an MS endemic farm. PCR revealed that the flock became infected within nine weeks. At 22 weeks the flock was transferred to a clean and disinfected house on a previously depopulated farm. The birds were then subjected to three treatments with fluoroquinolones due to recurrent Escherichia coli peritonitis and from the 32 weeks of age they received 600 ppm of oxytetracycline hydrochloride continuously in the feed. Monitoring by PCR showed a decrease in MS positive birds after 34 weeks of age and MS may have been eradicated as judged by consistent negative results in PCR. We conclude that intensive antibiotic treatments supported by adequate biosecurity could clear MS from infected broiler breeders.

Campylobacter sp is a microaerophilic, thermotolerating Gram negative bacterium, known to be one of the main causes of food-borne human infections. Among the foods that carry these microorganisms, the chicken is outstanding. In Brazil, a large chicken exporting country, few researches are conducted about their prevalence in breeder hens and the transmission through eggs. The aim of this research was to verify the presence of Campylobacter sp in the shells and within the eggs from positive cloacal swab breeder hens. Microbiological analyses were made on cloacal swabs of 140 weighed breeder hens. The positive breeder hens were set aside and in a total of 244 of their eggs, Campylobacter sp was present in macerated shells and yolk contents during 7 weeks. Out of the 140 researched breeder hens, 25 (17.8%) were positive from cloacal swabs, however the eggs were not positive. The physiological characteristics of the birds, their eggs and Campylobacter sp favor the bacterium entering and surviving in the eggs, but in this study, no positive result was found in macerated shells or in the yolks, indicating that vertical transmission is probably an unusual event.

RESUMO Analisou