Role of Adhering Microflora in Competitive Exclusion of Salmonella from Young Chicks.

Adherence of gut microflora from Salmonella -free adult birds to the ceca of newly hatched chicks, and their role in protection against Salmonella was examined. The protective microflora remained attached to the cecal wall after four successive washings. Cultures of washed ceca taken from chicks 30 min to 1 h after treatment with fecal culture gave partial protection.

ICMSF Methods Studies. XVI. Comparison of Salt Polymyxin Broth with Glucose Salt Teepol Broth for Enumerating Vibrio parahaemolyticus in Naturally Contaminated Samples.

Two media, glucose salt teepol broth (GSTB) and salt polymyxin broth (SPB), were compared for their efficacy in enumerating Vibrio parahaemolyticus in naturally contaminated samples using the most probable number (MPN) procedure. Eleven laboratories in four countries participated, six of them using two analysts. One hundred ninety-six of 335 samples were found to contain V.

Competitive Exclusion of Salmonella from Newly Hatched Chicks by Mixtures of Pure Bacterial Cultures Isolated from Fecal and Cecal Contents of Adult Birds.

Oral administration of defined mixtures of bacterial isolates from fecal and cecal contents of adult chickens protected young chicks against infection with Salmonella . One-day-old chicks were treated with mixtures containing 50, 40, 25 and 10 bacterial isolates and challenged 2 d later with 10, 10 and 10 colony-forming units of nalidixic acid-resistant Salmonella typhimurium . The chicks were examined for infection 6 d after challenge.

ICMSF Methods Studies. XV. Comparison of Four Media and Methods for Enumerating Staphylococcus aureus in Powdered Milk.

Four media were examined for their usefulness in enumerating Staphylococcus aureus inoculated (a) into milk that was then dried or (b) directly into dried milk powder. In all, seven strains of S. aureus were inoculated individually into each preparation and were enumerated after two periods of storage (18 to 19 d and 60 to 61 d).

Minimum Intestinal Inoculum for Nurmi Cultures and a New Method for Determining Competitive Exclusion of Salmonella from Chicks.

Protection of chicks against Salmonella infection was obtained by oral administration of Nurmi cultures. The Nurmi cultures were prepared by inoculating adult chicken intestinal material (10 to 10 g) into anaerobic liquid medium and incubating for 3 d at 37°C. Excellent protection was obtained with cultures initiated with as little as 10 g of fecal or cecal content; progressively less protection with 10 to 5 × 10 g; and none with cultures initiated with 10 g.