Valutazione del livello di contaminazione batterica in uova ed embrioni di pollo presso un incubatoio industriale

Hygiene and biosecurity deficiencies in breeding farms are amplified exponentially in the hatchery. The microbial population present in the hatchery has a significant impact on the quality of the chicks, on their chances of survival and their productive performances. The purpose of the present study was to assess the degree of bacterial contamination of chicken eggs in an industrial poultry hatchery. Samples of twenty batches of eggs, collected at different stages of the incubation, from the arrival to the hatcher, were subjected to bacteriological tests. The bacterial contamination of the eggs at the arrival, both of the shells than of the yolks, was found to be rather low. Escherichia coli, Pseudomonas aeruginosa and other bacteria of minor importance such as Citrobacter freundii, Providencia alcalifaciens, Enterobacter spp., Enterobacter agglomerans, Pseudomonas cepacia, Sphingomonas paucimobilis were isolated. At the hatching, the bacterial contamination was significantly larger. Escherichia coli was present in the 88,25% of eggs pipped but chicks dead-in-shell, and in most of the chicks dead-in-shell without pipping (22%). Various other bacteria species were also isolated (in association or not with Escherichia coli or Salmonella Livingstone), in particular: Pseudomonas aeruginosa, Proteus mirabilis, Enterobacter spp., Escherichia fergusonii, Citrobacter koseri, Citrobacter amalonaticus, Citrobacter freundii, Acinetobacter calcoaceticus, Acinetobacter lwoffii, Serratia liquefaciens. Salmonella Livingstone was isolated from dead-in-shell chicks of two batches of eggs. The results of the present survey confirm the role of Escherichia coli as one of the major bacterial contaminant of poultry hatcheries. Moreover, results of our study highlight how the hatchery may have an amplifier effect of the bacterial contamination. Pseudomonas aeruginosa and Escherichia coli, present respectively in the 5% and in the 10% of the batches of eggs at the arrival, were found during the hatching respectively in the 15% and 100% of dead-in-shell chicks.