Enteric Pathogens in Monkeys

From 1964 to 1967, 6,646 monkeys, representing 10 primate species, were examined for Shigella and Salmonella infections upon arrival at the National Center for Primate Biology. Of these animals, 12% were infected with Shigella, and 75% of the Shigella isolates were S. flexneri 4. The incidence of Salmonella infections decreased from 12 to 3% during the period of study. Epidemiological studies of animals in the colony for 90 days or more indicated no seasonal variation in the occurrence of Shigella and Salmonella. Many of the isolates from incoming monkeys as well as from laboratory-conditioned animals were resistant to chloramphenicol, dihydrostreptomycin, and tetracycline. The possible operation of drug-resistance factors in these infections is discussed.     

Survival of Aerobic and Anaerobic Bacteria in Chicken Meat During Freeze-Dehydration, Rehydration, and Storage

Total and anaerobic counts were ascertained on boneless, cooked, cubed, frozen chicken meat. We determined survival of aerobes and anaerobes in the natural flora after the meat was freeze-dehydrated and rehydrated at room temperature for 30 min and at 50, 85, and 100 C for 10 min. Total and anaerobic counts of bacteria in the rehydrated meat were established during storage of samples at 4, 22, and 37 C-until a spoilage odor was detected. Samples were also inoculated with Clostridium sporogenes and were dried and rehydrated at 100 C and stored at 37 C. Approximately 21% of the aerobes and 37% of the anaerobes survived drying and rehydration at room temperature. Many genera of aerobes, anaerobes, and facultative anaerobes survived drying and rehydration at 50 C; only sporeformers survived rehydration at 85 or 100 C. Low-temperature (4 C) storage of rehydrated meat produced ample shelf life (over 20 days), whereas storage at the higher temperature resulted in a shelf life of less than 30 hr. Approximately 81% of the C. sporogenes cells survived rehydration at 100 C and grew to over 10(7) cells within 40 hr. Our study presents additional data for adequate microbiological control in processing of freeze-dehydrated meat. Also, it points out the natural selection for sporeformers at high temperature of rehydration, stressing the need for consumer education in product handling for safety purposes.     

Allescheria boydii and Aspergillus fumigatus Skin Test Antigens

May, Lewis K. (Woman's Medical College of Pennsylvania, Philadelphia), Ralph A. Knight, and H. William Harris. Allescheria boydii and Aspergillus fumigatus skin test antigens. J. Bacteriol. 91:2155-2157. 1966.-Protein and polysaccharide fractions were extracted from culture filtrates of Allescheria boydii and Aspergillus fumigatus by the methods of Seibert and of Heidelberger, and injected intradermally into guinea pigs previously infected with these fungi. The diameter of erythema and induration was determined at 8, 24, and 48 hr. The protein and polysaccharide antigens yielded specific skin reactions in homologously infected guinea pigs. Erythema appeared at 8 hr with both the protein and polysaccharide antigens. At this time, the polysaccharide skin tests showed erythema and a central blanched wheal. A similar wheal was not observed with the protein. The erythema of the polysaccharide reaction began fading at 24 hr, whereas the protein reaction remained unchanged through 48 hr with both antigens. In guinea pigs, the area of erythema was more constant and thus easier to measure than was induration.     

Tissue specific expression of rat peptidylglycine alpha-amidating monooxygenase activity and mRNA

The tissue specific expression of peptidylglycine alpha-amidating monooxygenase [(PAM) EC 1.14.17.3], an enzyme which catalyzes the formation of amidated bioactive peptides from their glycine-extended precursors, was examined in adult rat. Soluble and membrane-associated PAM enzymatic activities were determined, and the levels and size classes of PAM mRNA were examined by Northern blot analysis. PAM specific activity varied 1000-fold in the tissues examined, with highest levels in heart atrium, pituitary and salivary glands, and hypothalamus. The fraction of total PAM activity that was membrane associated varied from approximately 70% in heart atrium to 10% in neurointermediate pituitary lobe and thyroid gland. Levels of PAM mRNA varied over 300-fold. In the heart atrium, PAM mRNA accounts for more than 0.1% of the mRNA. For many tissues the ratio of total PAM specific activity to PAM mRNA levels was similar; however, PAM activity was higher than expected from mRNA levels in the salivary glands and lower than expected in several tissues, including heart ventricle. Three major size classes of PAM mRNA were identified among the tissues. Use of RNAse H indicated that differences in size were not due to the length of the poly(A) tail. The heart and central nervous system expressed PAM mRNA of the 4.2 kilobase (kb) and 3.8 kb size classes, while the remaining tissues expressed predominantly 3.8 kb and 3.6 kb classes; few tissues contained only one size class of PAM mRNA. The two major forms of PAM mRNA in adult heart atrium differ by the presence or absence of a 315 nucleotide segment in the protein coding region. Using a cDNA probe from within this segment, the 4.2 kb and 3.8 kb size classes of PAM mRNA in the central nervous system appeared to resemble those in the heart atrium. In the remaining tissues, a subset of PAM mRNAs in the 3.8 kb and 3.6 kb size classes hybridized with this probe, suggesting that additional forms of PAM mRNA are present.