Seven influenza A (H3N2) high-yielding vaccine candidate strains were examined. Antigenic analysis revealed that 5 of the strains could be distinguished antigenically from their corresponding wild type parent viruses. Comparative sequence data for the HA1 domains of the HA (hemagglutinin) genes for these 5 high-yielding viruses and the corresponding wild type parents demonstrated one to three amino acid substitutions within each virus pair, with at least one amino acid change being located in a previously defined antigenic site. Comparison of the HA sequences of the 2 antigenically indistinguishable virus pairs revealed no amino acid differences in 1 and one amino acid change in the other. Examination of 1 additional wild type virus, A/Guangdong/39/89, and its three high-yielding derivatives obtained either by serial egg passage or by reassortment revealed an additive effect of the HA and M genes in creating the high-yielding phenotype.

PCR was used to amplify and sequence the complete HA1 region of the haemagglutinin (HA)-encoding genes of 10 clinical isolates of influenza virus of the H1N1 or H3N2 subtypes. These sequences were compared to those obtained from viruses isolated from the same specimens after passage in eggs and MDCK cells. Amino acid substitutions in the egg-derived HA sequences were found in nine out of the 10 specimens analysed, whereas seven out of eight of the MDCK-derived HA sequences were identical to those in the corresponding original specimens. Changes in the H1 HA occurred at residues 77a, 196 (also found in the corresponding HA from the MDCK isolate), 225, 226 and 227; changes in the H3 HA occurred at residues 137, 156, 186, 248 and 276. In addition, we have shown that an amino acid change at residue 145 in the HA of the H3 subtype that was previously demonstrated to be egg-selected is now present in circulating strains.

Microbiological profiles were determined for surfaces of the command module, lunar module (ascent and descent stages), instrument unit, Saturn S-4B stage, and the spacecraft lunar module adapter of the Apollo 10 and 11 spacecraft. Average levels of contamination of the command module were 2.1 x 10(4) and 2.7 x 10(4) microorganisms per ft(2) for Apollo 10 and 11, respectively. With the exception of the exterior surfaces of the ascent stage of the lunar module and the interior surfaces of the command module, average levels of microbial contamination on all components of the Apollo 11 were found to be lower than those observed on Apollo 10. For each Apollo mission, approximately 2,000 colonies were picked from a variety of media and identified. The results showed that approximately 95% of all isolates were those considered indigenous to humans; the remaining were associated with soil and dust in the environment. However, the ratio of these two general groups varied depending on the degrees of personnel density and environmental control associated with each module.

Morphological, cultural, biochemical, and serological characteristics of 79 strains of Vibrio parahemolyticus isolated from patients suffering from gastroenteric disease in Japan were compared with 17 suspected V. parahemolyticus cultures isolated from wound infections and 14 nonpathogenic vibrios isolated from an estuarine environment in the United States. These groups were differentiated on the basis of several key reactions which included: the range of growth temperature and salt tolerance; the production of catalase and acetoin; the hydrolysis of starch; the fermentation and utilization as single carbon source of sucrose, cellobiose, and arabinose; and the ability to swarm on 1% agar. The separation of the groups on the basis of cultural and biochemical analyses was confirmed by means of slide agglutinations with specific anti-K antisera. The results of this study strongly suggest that the wound infection isolates are V. parahemolyticus species which are easily distinguished from the nonpathogenic estuarine vibrios.

Recent work on Clostridium perfringens foodborne disease has established that any type, whether classical or “food-poisoning,” may cause illness if present in sufficiently large numbers. Cultural methods for detection and enumeration of the organism have been suggested, and some of these methods have proven satisfactory in field trials. New approaches, such as the cultural or serological examination of patients' feces or the direct examination of foods for toxin content, have been suggested. The problem has been shown to be of sufficient importance to warrant continued and increased study.

Rabbit, National Communicable Disease Center (NCDC) equine, and International Standard antitoxins to types A and B botulinal toxins were compared by passive hemagglutination (HA), hemagglutination inhibition (HI), and gel-diffusion. The HA reactions in general were quite specific, although cross-reactions were observed. The extent of cross-reaction was greater with B antitoxins and A botulinal toxoid-sensitized red blood cells. The different antitoxins behaved similarly in HI and gel-diffusions, though the reactions of the NCDC and International antitoxins were weaker than those of rabbit antitoxins in gel-diffusions. Hemagglutination inhibition and gel-diffusion reactions with toxic cultures suggested that the in vitro specificity of the A toxin-antitoxin did not involve neutralizing antibodies. Hemagglutination inhibitions and gel-diffusions with B toxins did not resolve the question of the involvement of neutralizing antibodies in in vitro specificity, since fairly toxic cultures inhibited HA and formed bands believed to be associated with type specificity, whereas a virtually non-toxic B culture neither inhibited HA nor formed a line of identity with the type specific systems in gel-diffusion.

Summary A simplified method is described for coupling proteins to red cells using the water-soluble carbodiimide, 1 - ethyl - 3 - (3 - dimethylaminopropyl) carbodiimide hydrochloride. The procedure is simpler than BDB coupling and the sensitized cells are more stable than those in the BDB system. The data indicated a marked similarity in the specificity and sensitivity of ECDI-and BDB-hemagglutination.

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.

Procedures were developed for assay of staphylococcal enterotoxins in foods, using microslide gel double diffusion test.(1) Foods were prepared for assay by addition of water (homogenization or mashing in case of cereal foods) adjustment of pH to 7.4-7.6, blending, and centrifugation. The supernatant fluids were then adjusted to pH 4.5 (in case of animal foods) or pH 6.0, and centrifuged. Supernatant fluids taken at pH 4.5 were readjusted to pH 6.0, and centrifuged. From these supernatant fluids, enterotoxins were partially purified by adsorption on CM-Sephadex C-50 equilibrated with 0.01M sodium phosphate (pH 6.0), washing with 0.01M sodium phosphate (pH 6.0), then eluted with 0.2M sodium chloride in 0.1M sodium phosphate (pH 7.6), and concentrated by dialysis against polyethylene glycol.Adequate dosage levels of CM-Sephadex in the batch ion exchange for various foods were determined, individually.(2) By these procedures, enterotoxins were detected in 12 out of 16 foods suspected for cause of poisoning outbreaks. Enterotoxin A (50%) and A+D (33%) were predominant types. Concentrations of enterotoxins detected in foods were ranging up to 0.3μg/g, and estimated at 0.05μg/g on the average. In 4 outbreaks, neither enterotoxins nor enterotoxin-producing staphylococci were isolated from the suspected foods.(3) The extract from suspected cream puff containg 4.5μg of enterotoxin A induced emetic responses in a volunteer by feeding test.

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 μg/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 μg 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.

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.

RECOVERY of coagulase-positive StaphyloCOCCUs aureus from food implicated in a foodpoisoning outbreak is only circumstant.,ial evidence that the correct etiological agent has been found. Even the determination by animal studies that the strain isolated is capable of producing enterotoxin doeis not prove that it did so in the food. Positive proof depends on demonstration of the enterotoxin in the food itself. Such proof can be obtained by feeding the food to monkeys or human volunteers, but the results are subject to the variations in susceptibility known to occur among both test subjects. The purification (1) of Enterotoxin. B, S6 type ["E" type of Casman (2) ] and t,he determination that it was an antigenically act-ive protein (.3-5) opened t.he way to use of serologic methods for direct detection of enterotoxin in foods. Although Enterotoxin B occurs in food infrequently (2,6) compared with the frequency of Enterotoxin A, 196E type ["F" type of Casman (2)], it is a useful substitute for preliminary studies because it can be produced in a highly purified form. This report deals with the results obtained and the difficulties encountered in the use of the various gel-diffusion techniques for the, direct serologic detection and quantification of 'Enterotoxin B 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.

"The Effect of Chemotherapy on the Tuberculin Sensitivity of Leukocytes from Tuberculous Patients1." American Review of Respiratory Disease, 81(1), pp. 100–101

Journal Article The Relationship Between Insusceptibility to Phagocytosis and Virulence of Certain Klebsiella PneumoniaeStrains Get access Herbert E. Hall, Herbert E. Hall Department of Bacteriology, University of Kentucky, Lexington, Kentucky Search for other works by this author on: Oxford Academic PubMed Google Scholar James C. Humphries James C. Humphries Department of Bacteriology, University of Kentucky, Lexington, Kentucky Search for other works by this author on: Oxford Academic PubMed Google Scholar The Journal of Infectious Diseases, Volume 103, Issue 2, September 1958, Pages 157–162, https://doi.org/10.1093/infdis/103.2.157 Published: 01 September 1958 Article history Received: 08 March 1958 Published: 01 September 1958