March 24, 2008

 

Flies found to transmit Salmonella among chicken and eggs

 

 

A recent study showed that the mere presence of flies in poultry houses may not cause Salmonella, but a hen's eating of flies seem to be the primary mechanism of Salmonella transmission from flies to birds, the USDA Agricultural Research Service (ARS) reported.

 

Musca domestica or the common housefly readily picks up bacteria from its surroundings, ARS microbiologist Peter Holt and entomologist Christopher Geden said.

 

The researchers explained that when the chickens eat the flies, the bacteria get inside the birds.

 

Holt conducted three experiments where he placed chickens in individual, adjacent laying cages.

 

Geden delivered fly pupae just 48 hours short of hatching, ensuring the flies are not exposed to any microbe prior to emergence. The fly pupae were placed in an open box in the bird room.

 

Three days later, hens were discovered to be orally infected with Salmonella.

 

The researchers also detected the bacteria in and on 45-50 percent of the flies within the first 48 hours of the flies' hatching.

 

Uninfected hens were then exposed to the newly infected flies. The researchers said that the healthy birds did not become infected with the mere presence of the flies, but got infected when they eat the flies.

 

The research indicates that simple physical contact may not be the primary method of transfer of Salmonella bacteria to different surfaces in a poultry house.

 

However, according to the researchers, a hen's eating of contaminated flies does seem to be the primary mechanism of transmission of Salmonella from flies to birds.

 

Holt concluded that the flies in poultry houses are not only a nuisance, but also a threat to the safety of poultry products.