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Biomedical subjects

H E HALL

Publications and source records attributed to H E HALL.

At least 19 recordsLinked to original sources
PubMed1965

CLOSTRIDIUM PERFRINGENS IN MEAT AND MEAT PRODUCTS.

A total of 262 specimens of meat and meat dishes were examined for the presence of Clostridium perfringens. Of this total, 161 were raw, unprocessed beef, veal, lamb, pork, or chicken; 101 were processed meats and meat dishes. C. perfringens was isolated from 113 (43.1%) of these specimens. The highest percentage of contamination (82%) was found in veal cuts, and the lowest (4.7%) in sliced sandwich meats and spreads. Only 2 of the 113 isolates were shown to produce heat-resistant spores, which indicates a very low incidence (0.8%) of contamination. These findings indicate that outbreaks of C. perfringens food-borne disease in the Cincinnati area are caused principally by the contamination of the food with vegetative cells or spores of the organism after cooking. Studies of the effects of various holding temperatures on the growth of C. perfringens indicated that, in the range of 5 to 15 C, no multiplication would occur, but that viable cells would still be present at the end of a 5-day holding period. Extremely rapid growth occurred at temperatures around 45 C, and complete inhibition of growth was accomplished between 49 and 52 C.

Animals↗
PubMed1963

Resistance of free-living nematodes to staphylococcal enterotoxin.

The usefulness of free-living nematodes for assaying staphylococcal enterotoxin was evaluated with a 98% pure enterotoxin B on five different nematodes. Included in the evaluation was an enterotoxin B in a crude culture filtrate. The filtrate of a culture of nonenterotoxigenic strains of Staphylococcus aureus, the uninoculated respective broth media, and distilled water were used as controls. The purified enterotoxin was found to exert no toxic effects at dosages ranging from 10 to 1,000 mug/ml for as long as 24 hr. Utilization of the toxin-protein by these nematodes was evidenced by their propagation after exposure times longer than 24 hr. The crude filtrate, containing 28 mug of enterotoxin per ml, was detrimental to nematodes to the same degree as the nontoxic filtrate and the uninoculated broths, in that they all caused irritation to external genitalia, motility changes, and death after comparable exposure times. This is in agreement with earlier observations that standard bacteriological fluid media, or broths containing over 1% protein hydrolysate or 1 to 2% salts, exert toxic effects on free-living nematodes.

Antitoxins↗
PubMed1963

CHARACTERISTICS OF CLOSTRIDIUM PERFRINGENS STRAINS ASSOCIATED WITH FOOD AND FOOD-BORNE DISEASE.

Hall, Herbert E. (Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio), Robert Angelotti, Keith H. Lewis, and Milton J. Foter. Characteristics of Clostridium perfringens strains associated with food and food-borne disease. J. Bacteriol. 85:1094-1103. 1963.-A total of 83 strains of Clostridium perfringens-30 from England, Europe, and Asia, associated with food-poisoning outbreaks; 28 from the United States, associated with outbreaks or contaminated foods; and 25 from natural or pathological sources-have been studied to determine their serological relationships, sporulation and heat-resistance of spores, and their hemolytic activity on mammalian bloods. A comparison of the results obtained with these three groups of strains reveals that the Eurasian group is characterized by serological typability, poor sporulation with the production of heat-resistant spores, and a hemolytic activity limited to the production of partial hemolysis on horse, ox, and sheep bloods, whereas the strains from natural and pathological sources in this country are not serologically typable, sporulate well but the spores are not heat-resistant, and are hemolytically active, producing both partial and complete hemolysis on horse, ox, and sheep bloods. The American food-poisoning strains have a wide variety of characteristics. Some strains resemble the Eurasian in their serological typability and the production of heat-resistant spores, but sporulation and hemolytic activity are more like the strains from classical sources. On the basis of these data, it appears unlikely that C. perfringens food-poisoning outbreaks in the United States are restricted to strains meeting the criteria of classification described by British workers and that the isolation of large numbers of any strain of this organism from an incriminated food must be considered as having a possible bearing on the etiology of the outbreak.

Animals↗
PubMed1962

Quantitation of Clostridium perfringens in foods.

A procedure is described for identifying and enumerating Clostridium perfringens in foods by means of a simplified agar plating method, followed by confirmation of black colonies in tubes of motility-nitrate medium and sporulation broth. The test is routinely completed within 48 hr. Under experimental conditions, the procedure has been used to quantitatively recover various levels of C. perfringens contamination in a variety of foods and has recovered as few as ten C. perfringens per g without interference from food constituents and associated flora. Under practical conditions of field application, the method has been used to investigate five food-poisoning outbreaks, and C. perfringens was implicated as the etiological agent in two of these outbreaks.

Agar↗