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J H SILLIKER

Publications and source records attributed to J H SILLIKER.

At least 19 recordsLinked to original sources
PubMed1964

ENHANCING EFFECT OF FECES ON ISOLATION OF SALMONELLAE FROM SELENITE BROTH.

The addition of feces to selenite broth significantly enhanced the ability of this medium to select for salmonellae in an environment initially containing overwhelming numbers of coliform bacteria. Either heat-sterilized or Seitz-filtered feces produced this effect. In most experiments, the selectivity of selenite broth was unaffected by unsterile feces. Human blood and plasma markedly reduced selenite efficiency. In a base medium supporting both coliform and Shigella growth, heat-sterilized feces imposed a measure of selectivity for Shigella.

Bacteriological Techniques↗
PubMed1964

ISOLATION OF SALMONELLAE FROM FOOD SAMPLES. VI. COMPARISON OF METHODS FOR THE ISOLATION OF SALMONELLA FROM EGG PRODUCTS.

THE RECOVERY OF SALMONELLAE FROM EGG PRODUCTS WAS STUDIED, BY USE OF THREE DIFFERENT ENRICHMENT PROCEDURES: (i) selenite broth, (ii) selenite broth containing 10% sterile feces, and (iii) the lactose pre-enrichment procedure. Brilliant Green Agar was used throughout as the recovery medium. Although the lactose pre-enrichment methodology promoted Salmonella recovery from samples containing small numbers of dormant organisms, the efficiency of this enrichment method is adversely affected by unfavorable coliform-Salmonella ratios. Under such conditions, early subculture of lactose broth into selenite broth is indicated. Selenite broth containing 10% sterile feces was more efficient than the lactose pre-enrichment methodology in promoting the growth of "dormant" salmonellae. Albumen adversely affected recovery of salmonellae from selenite broth, whereas whole egg and egg yolk enhanced Salmonella recovery from this medium. The selenite-feces medium presents a solution to the major problems encountered in the detection of salmonellae in egg products and offers an approach to a single medium in which food-borne salmonellae will manifest themselves with a minimum of laboratory manipulation.

Agar↗
PubMed1964

OCCURRENCE OF GRAM-POSITIVE ORGANISMS POSSESSING CHARACTERISTICS SIMILAR TO THOSE OF SALMONELLA AND THE PRACTICAL PROBLEM OF RAPID AND DEFINITIVE SALMONELLA IDENTIFICATION.

The occurrence and incidence of gram-positive organisms which possess some biochemical and serological characteristics in common with salmonellae are described. These organisms were encountered as contaminants in various food products as well as in feces. Their growth in various Salmonella enrichment media, typical Salmonella-like growth on differential selective media, biochemical similarities to Salmonella, and agglutination in Salmonella polyvalent O antiserum serve as a source of possible confusion in analyses for Salmonella. Although a definitive identification was not performed, preliminary results indicate that these bacteria closely resemble members of the genus Brevibacterium. No sanitary significance could be associated with these bacteria, because they were never found to coexist with Salmonella. The occurrence of these bacteria illustrates the pitfalls of a cursory examination for Salmonella. On the premise that ultimate identification of Salmonella rests upon serological procedures, a rapid and definitive identification of suspect Salmonella isolates is proposed, based upon reactions with polyvalent group O, group O, and Spicer-Edwards H antisera.

Agglutination↗
PubMed1964

SOME CHARACTERISTICS OF AN OLEATE-REQUIRING, HEMOLYTIC PEDIOCOCCUS.

Deibel, R. H. (St. James Hospital, Chicago Heights, Ill.), J. H. Silliker, and P. T. Fagan. Some characteristics of an oleate-requiring, hemolytic Pediococcus. J. Bacteriol. 88:1078-1083. 1964.-A gram-positive, catalase-negative, tetradforming coccus, isolated from a bronchial aspirate, is described. The organism was classified as a member of the genus Pediococcus on the basis of morphological and physiological characteristics. It differed from previously described members of this genus in that it evidenced a requirement for oleic acid, even in complex culture media. This isolate produced hemolysis on blood-agar formulated with certain specimens of human blood and not with others. It was demonstrated that hemolysis required oleate supplementation and that the level of this fatty acid required for hemolysis is greater than that necessary for growth of the organism. A cell-free hemolysin could not be demonstrated in the culture supernatant fluid of oleate-grown cultures. The organism was isolated from a patient suffering from tuberculosis; however, attempts to isolate similar organisms from other tuberculous patients as well as from routine throat and sputum specimens were negative. No pathogenicity was manifested when laboratory animals were inoculated with the hemolytic Pediococcus.

Catalase↗
PubMed1963

FOOD-POISONING POTENTIAL OF THE ENTEROCOCCI.

Deibel, R. H. (American Meat Institute Foundation, Chicago, Ill.), and J. H. Silliker. Food-poisoning potential of the enterococci. J. Bacteriol. 85:827-832. 1963.-A total of 23 enterococcus strains were fed to two and sometimes three human volunteers in an effort to elicit food-poisoning symptoms. Each culture was consumed after it was grown in whole sterile milk or on the surface of commercially sterile ham slices. Six strains of Streptococcus faecalis var. liquefaciens were consumed after complete liquefaction of gelatin. In addition, strains of S. faecalis were consumed after having been grown in media which altered the energy metabolism (arginine, gluconate, malate, and pyruvate). In no instance were any of the above conditions of growth conducive to the production of food-poisoning symptoms in the volunteers. Moreover, no evidence was found to indicate that either the age of the culture or the disruption of the cell was a factor in the production or release of a toxic principle. It would appear that until the environmental conditions (if any) for food poisoning are defined the evidence obtained suggests that the association of enterococci and food poisoning is questionable.

Animals↗
PubMed1962

The effect of nitric oxide on bacteria.

Nitric oxide, as well as several other oxides of nitrogen, were assayed for their antibacterial action. It is shown that nitric oxide has virtually no effect on bacteria, whereas both NaNO(3) and NaNO(2) appear to have either neutral or stimulatory effects. It is suggested that the formation of nitrous acid is mainly responsible for the quantitative as well as the qualitative changes that occur in the bacterial flora of cured meat. A pH-dependent "nitrite cycle" is presented to account for the production of nitrous acid in cured meat systems.

Bacteria↗
PubMed1962

The development of a nonmicrobial off-condition in fresh meat.

It has long been accepted, prima facie, that bacteria are the sole cause of a "sour" condition which is occasionally but persistently found in some fresh beef rounds. Evidence is presented which indicates that this condition often bears no relation to the bacteriology of the muscle involved. It was observed that sour rounds contain elevated quantities of volatile fatty acids. On the basis of experiments in which this condition was artificially induced in vivo, it is suggested that a metabolic block of meat enzymes could account for this build-up of short chain acids.

Animals↗
PubMed1961

Isolation of Salmonellae from food samples. IV. Comparison of methods of enrichment.

A comparison of various methods of enhancing frequency of Salmonella isolations revealed that inoculation of a second enrichment broth, with culture from the first, was no improvement over the single direct enrichment method. It was inferior to centrifugation. Selenite was observed to produce more positive isolations at 48 hr than at 24. No change occurred in tetrathionate. Reconstitution of dried albumen with water produced a significant increase in isolations over direct inoculation of enrichment broth in the case of tetrathionate but not selenite broth.Pre-enrichment in lactose broth before inoculation of enrichment media was vastly superior to reconstitution in water for both enrichment broths. A comparison of results obtained using dulcitol, mannitol, lactose and carbohydrate-free purple broths in pre-enrichment indicated that the carbohydrate added was immaterial.

Culture Media↗