Biomedical subjects

T R Nicoll

Publications and source records attributed to T R Nicoll.

3 recordsLinked to original sources

PubMedDate not supplied

Preliminary studies on bacterial interference of staphylococcosis of chickens.

Previous studies indicated that Staphylococcus epidermidis strain 115 might be an effective interfering agent in reducing the rate of staphylococcosis in turkeys. In the present study, strain 115 was avirulent when administered to 3-day-old chicks by oral, aerosol, or intravenous route. Strain 115 adhered specifically to tracheal, lung, air-sac, and liver cells in vitro and interfered with subsequent colonization by virulent Staphylococcus aureus. In vivo colonization of lungs and livers of young chicks occurred following exposure to aerosols of strain 115. Strain 115 interfered with the in vivo colonization of lungs and livers by virulent S. aureus.

Animals↗

PubMedDate not supplied

Staphylococcosis of turkeys. 1. Portal of entry and tissue colonization.

Staphylococcus aureus and various coagulase-negative staphylococci were isolated from turkeys with staphylococcosis. Virulent S. aureus adhered well (averaged more than 100 bacteria per tissue cell) in vitro to cells from tissues of the respiratory tract but did not adhere well (averaged fewer than 12 bacteria per tissue cell) to cells from tissues of the alimentary tract. Some avirulent coagulase-negative staphylococci also adhered well to cells from the respiratory tissues. Lungs and livers of turkeys became colonized with virulent S. aureus following experimental aerosol exposure. Tracheas, livers, and hock joints of some market-age turkeys were naturally colonized with S. aureus and various species of coagulase-negative staphylococci.

Aerosols↗

PubMedDate not supplied

Staphylococcosis of turkeys. 5. Large-scale control programs using bacterial interference.

Staphylococcus epidermidis strain 115 was used as an interfering agent to reduce the incidence of staphylococcosis in turkeys. In 1984, the entire Utah turkey population of about 3 million turkeys was exposed at 1 to 10 days and at 4 to 6 weeks of age to aerosols of strain 115. Some staphylococcosis was still observed in range turkeys but appeared to be at a lower rate than in previous years. At processing, about 30% of the turkeys were still colonized with strain 115. A control study was carried out in 1985 to quantitate the level of reduction of staphylococcosis in turkeys treated with strain 115. About 1 million turkeys were treated, and 2 million remained untreated. Flocks from both groups were examined periodically for existing cases of staphylococcosis. Of 174,250 treated turkeys examined, 90 had staphylococcosis on the days examined, whereas 255 of the 183,500 untreated turkeys that were examined had staphylococcosis. Turkeys housed in range sheds had five times the incidence of staphylococcosis that turkeys in enclosed coops had. The gross mortality rate of 200,636 treated turkeys was 2.7% lower (P less than 0.001) than that of 189,450 untreated control turkeys that were monitored.

Aerosols↗