Salmonella in eggs and egg products with fluorescent antibody. Appl. Microbiol. 12:447-450. 1964.-Organisms of the genus Salmonella are detected in eggs and egg products within 24 hr in the presence of Pseudomonadaceae and other Enterobacteriaceae by combining selective cultural methods with fluorescentantibody techniques. These techniques are specific for Salmonella when H antibodies are used. Absorption techniques are necessary before the 0 antibodies give specific reactions for Salmonella. No cross-reactions appear when H antiserum is used. Absorption and interference techniques indicate the test is specific for Salmonella. Salmonellosis is one of the important food-borne infections in the world today; the United States alone reported almost 19,000 cases in 1963 (U.S. Department of Health, Education, and Welfare, 1964). Conventional methods for the isolation and identification of Salmonella are tedious and time-consuming. The development of a rapid and accurate test would be an invaluable aid toward controlling these organisms in dried eggs and egg products. Coons et al. (1942) introduced the fluorescent-antibody (FA) technique and made possible a new and rapid serological method of detecting microorganisms. In principle, this technique is an immunological staining procedure which uses homologous antibody conjugated with suitable fluorochromes. FA technique is now a common tool in microbiology and has generally been proved satisfactory. Thomason, Cherry, and Moody (1957) applied this method for the detection of several serotypes of Salmonella in pure culture. Later, Thomason, Cherry, and Edwards (1959) found that the value of the method for the rapid detection of Salmonella in feces was impaired by nonspecific staining.

BURROUGHS, ANI) WILLIAM C. CHRISTIANSEN. Continuous culture of ruminal microorganisms in chemically defined medium. II. Culture medium studies. Appl. Microbiol. 10:583-592. 1962. Ruminal ciliates have been grown in continuous culture in chenmically defined media and in the absence of viable bacteria. Oligotrichic ruminal ciliates seem to reqjuire insoluble carbohydrates for growth; the

Type A botulinum toxin was studied for its ability to inhibit the action of acetylcholinesterase. The chromogenic substrate, indophenyl acetate, was used for assay ofenzyme activity. Inhibition ofenzyme function was detected through use ofboth 6.6 X 10-6 mg (20 LDS0) and 6.6 x I010 mg (2 x 10-3 LD50) of type A botulinal toxin. Control assays were performed by use of both homologous antitoxin and heterologous antitoxins (types B and E). Enzyme inhibition was effectively prevented by use ofhomologous antitoxin only. The inhibition noted was specific and reproducible for given substrate, enzyme, and toxin concentrations.

QUINN, LOYD Y. (Iowa State University, Ames). Continuous culture of ruminal microorganisms in chemically defined medium. I. Design of continuous-culture apparatus. Appl. Microbiol. 10:580-582. 1962.-An apparatus is described which has been used for successful continuous culture of the ciliates from the rumen of cattle. Automatic control of feeding rate, pH, oxidation-reduction potential, temperature, stirring rate, aeration rate, salinity, and volume of the culture is provided for, using standard commercial equipment, whenever possible. The operation of this apparatus is described.

Nutritional requirements of Clostridium thermocellum were examined, and a defined medium was formulated which supported reproducible growth through 10 serial subcultures.