bluuebunny/crossref_metadata_2025 huggingface dataset:
Cephalexin and Cephaloglycin Activity In Vitro and Absorption and Urinary Excretion of Single Oral Doses in Normal Young Adults
Authors: Braun Peter , Tillotson James R. , Wilcox Clare , Finland Maxwell
Published: December 2020

A large number of recently isolated bacterial pathogens were tested for susceptibility to cephalexin and cephaloglycin by the replica inoculating method. Strains of group A hemolytic streptococci, viridans (alpha and gamma) streptococci, pneumococci, gonococci, meningococci, and penicillin G-sensitive
Staphylococcus aureus
were all moderately to highly susceptible to both of these cephalosporin analogues, nearly all of the strains being two to eight (median four) times more susceptible to cephaloglycin than to cephalexin. The penicillin G-resistant, penicillinase-producing strains of
S. aureus
varied in their susceptibility; many were moderately resistant to both analogues, particularly to cephalexin. Strains of enterococci,
Haemophilus influenzae
, and most of the common gram-negative bacilli were moderately to highly resistant. Reducing the size of the inoculum had variable effects on inhibition by these drugs, depending on the species or strain. The activity of cephalexin was very little affected by
p
H of the medium within the clinical range or by incubation at 37 C in broth for up to 24 hr. In contrast, cephaloglycin in broth deteriorated rapidly at 37 C, and its activity was markedly reduced in alkaline medium. Both cephalexin and cephaloglycin were rapidly absorbed and excreted into the urine after single oral doses of 500 mg. Much higher levels were achieved and sustained with the former. Absorption of both analogues was delayed when taken with food, and the levels in the serum were significantly higher and better sustained when probenecid was also given. Very high concentrations of cephalexin were excreted into the urine during the first 4 hr, and the levels were still high in the 4- to 8-hr collection. The concentrations of cephaloglycin in the urine at these times were much lower. An average of 80 to 93% of the dose of cephalexin and 25 to 30% of the cephaloglycin were accounted for as active drug in the urine collected in 8 hr. Both analogues were well tolerated.
Automated Procedure for Measuring Antigenicity of Extracted and Intact Influenza Virus
Authors: Hebeka E. K. , Walker R. M. , Beardmore W. B.
Published: December 2020

An automated serum-blocking (S-B) technique was developed in an attempt to find an in vitro test for the determination of the antigenicity of extracted influenza vaccines. The S-B test depends on the ability of an antigen to combine with (or block) specific (in this case, hemagglutination-inhibiting) antibodies. After mixing the test virus with a constant amount of specific antiserum and hemagglutinating virus in an Auto Analyzer, chicken erythrocytes were pumped into the system and the mixture was incubated by passing through coils. The hemagglutinated cells were removed and the residual cells were lysed. The optical density was read and recorded automatically. The S-B test was much more reproducible than the chicken cell agglutination (CCA) test. There was good correlation between the S-B and CCA titers of intact influenza virus, but not of ether-extracted influenza virus. The CCA titer of influenza strains of type A was reduced significantly during ether-extraction. The S-B titers indicated that there was no significant loss in specific antigenicity when influenza strains of types A and B were extracted with ether and Tween-80 according to the described procedure. The S-B test seemed to be a true measurement of the total antigens present in influenza vaccines.
Penicillium
Mycelium Waste as Protein Supplement in Animals
Authors: Doctor V. M. , Kerur L.
Published: December 2020

Dried
Penicillium
mycelium served as a protein source in animal diet when it was supplemented at 7.5% protein level along with 7.5% protein level from peanut meal. Under these conditions, the food consumption was optimal, and the rat growth response was comparable with 15% casein diet. The role of peanut meal appears to be twofold; it makes the mycelium diet more palatable and it supplies protein. The amino acids, lysine and threonine, which are found to be limiting in peanut meal, are reported to be present in the
Penicillium
mycelium. This type of formulation affords considerable economic advantage because both the peanut meal and the
Penicillium
mycelium are by-products and, therefore, are inexpensive sources of protein.
Lysozyme Production as an Aid for Identification of Potentially Pathogenic Strains of Staphylococci
Authors: Grossgebauer Klaus , Schmidt Bernhard , Langmaack Heike
Published: December 2020

Lysozyme production is a frequent property of potentially pathogenic staphylococci. In the present study, 1,186 strains of human origin, 85 strains of animal origin, and 156 strains of
Staphylococcus albus
(
epidermidis
) were tested. Of 1,114 coagulase-positive strains of human and animal origin, 1,098 were lysozyme-positive (98.5%). On the other hand, of 157 coagulase-negative strains which, based on further investigations, belong to the potentially pathogenic staphylococci, all were lysozyme-positive. All of the 156 strains (100%) belonging to the species
S. albus
(
epidermidis
) were lysozyme-negative. We conclude that lysozyme production is a better index of potentially pathogenic staphylococci than the measurement of free coagulase, especially in cases of strains of animal origin. It is possible that lysozyme production allows a differentiation between pathogenic and nonpathogenic coagulase-negative staphylococci.
Tissue Culture Method for Toxigenicity Testing of
Corynebacterium diphtheriae
Authors: Schubert Joseph H. , Bickham Susan T. , Wiggins Geraldine L.
Published: December 2020

A method for toxigenicity testing of
Corynebacterium diphtheriae
in tissue cultures was developed. Results were obtained by comparing destruction of the monkey kidney or, preferably, rabbit kidney monolayer by 0.1 ml of the
C. diphtheriae
culture in Elek's broth containing 20% rabbit serum with the appearance after the addition of 0.2 ml of a mixture of the
C. diphtheriae
culture and diphtheria antitoxin. The mixture of
C. diphtheriae
broth culture and 10 antitoxin units per ml was incubated for 1 hr at room temperature before it was added to the tissue cultures which were then incubated as long as 5 days; most results, however, were read in 72 hr. Elek's broth medium was superior to heart infusion broth for toxin production by
C. diphtheriae
. Addition of 20% rabbit serum improved toxin production in either broth. Numerous toxigenic and atoxigenic
C. diphtheriae
cultures were tested for toxigenicity in primary rabbit and monkey kidney tissue cultures. If properly controlled, this in vitro method appeared to have an advantage over the in vitro agar gel method; its results were comparable with the rabbit intradermal test. With the wider use of tissue cultures in most laboratories, we believe that the tissue culture method for toxigenicity would be more economical and easier to perform than the animal intradermal method.
Sporicidal Effect of Peracetic Acid Vapor
Authors: Portner Dorothy M. , Hoffman Robert K.
Published: December 2020

The sporicidal activity of peracetic acid (PAA) vapor at 20, 40, 60, and 80% relative humidity (RH) and 25 C was determined on
Bacillus subtilis
var.
niger
spores on paper and glass surfaces. Appreciable activity occurred within 10 min of exposure to 1 mg of PAA per liter and 40% or higher RH. The sporicidal rate decreased from the optimum at 80% RH to a slight effect at 20% RH. Spores on an impermeable surface were more difficult to kill than those on a porous one, probably because the cells tend to pile up on an impermeable surface and the vapor penetrates poorly through the layer of covering cells.
Variations in the Growth Response of Four Different Vitamin B
12
Assay Microorganisms to the Same Tissue and Standard Preparations
Authors: Cook Elizabeth A. , Ellis Lillian N.
Published: December 2020

Four microbiological assay procedures (
Escherichia coli, Lactobacillus leichmanni, Euglena gracilis
, and
Ochromonas malhamensis
) for the vitamin B
12
content of rat liver and kidney tissue were compared. Significant differences in the growth response for portions of the same sample based on the same standard preparations were noted. The liver values with
E. coli
were strikingly higher than those obtained with the other microorganisms, about which there was rather general agreement. With kidney tissue,
E. coli
again gave higher values, but not as significantly high as those obtained with
L. leichmannii
and
E. gracilis. O. malhamensis
values were significantly lower. These differences were greater than were expected and could not be explained by the differences of specificity and sensitivity of the assay organisms. Several methods of sample preparation, the possible presence of an alkali-heat-stable factor, different methods of sterilization of the sample plus medium, and different chromatographic procedures were explored in an attempt to find explanations for the variations in growth response, with the thought that these various methods would clarify in what form or forms the free and bound vitamin B
12
might exist in the samples. No clear-cut explanation was found.
Production of
d
-Mannitol and Glycerol by Yeasts
Authors: Onishi Hiroshi , Suzuki Toshiyuki
Published: December 2020

D-Mannitol has not so far been known as a major product of sugar metabolism by yeasts. Three yeast strains, a newly isolated yeast from soy-sauce mash,
Torulopsis versatilis
, and
T. anomala
, were found to be good mannitol producers. Under optimal conditions, the isolate produced mannitol at good yield of 30% of the sugar consumed. Glucose, fructose, mannose, galactose, maltose, glycerol, and xylitol were suitable substrates for mannitol formation. High concentrations of yeast extract, Casamino Acids, NaCl, and KCl in media affected significantly the mannitol yield, whereas high levels of inorganic phosphate did not show any detrimental effect.
Water Relations of Xerophilic Fungi Isolated from Prunes
Authors: Pitt J. I. , Christian J. H. B.
Published: December 2020

The predominant spoilage fungi of dried and high-moisture prunes were members of the
Aspergillus glaucus
group and
Xeromyces bisporus. Chrysosporium
spp. were also important. At the mean
p
H of prune flesh (3.8) and at 25 C,
X. bisporus
grew at water activities (a
w
) down to 0.605, and
Chrysosporium fastidium
grew to 0.686. Germination was always followed by growth, but within the 120-day incubation period, the minimum a
w
permitting asexual sporulation was usually higher than that permitting germination. Sexual sporulation often required an even higher a
w
. The water requirements of aspergilli were appreciably greater at this
p
H than near neutrality, no species germinating below 0.738 a
w
. This was probably a consequence of a high spore-death rate during incubation at low a
w
and
p
H.
Examination by Chromatography and Immunodiffusion of an Adenovirus 3 Isolated from Humans with Infectious Hepatitis
Authors: Hartwell W. V. , Auernheimer A. H. , Pearce G. W.
Published: December 2020

Prototype adenovirus 3 and adenovirus SC8, which was found in feces from a patient with infectious hepatitis and which was classified as adenovirus 3 by standard procedures, were compared by chromatography and immunodiffusion techniques. When the radioactive adenovirus moiety in SC8 had been separated from other radioactive components of tissue culture by gel filtration, a smaller infectious agent was detected, whereas with prototype adenovirus 3 one infectious agent was found. The large agent from SC8 was classified as adenovirus type 3 by serum neutralization tests, but results from homologous and heterologous immunodiffusion tests and heat sensitivity tests indicated that this agent was different from the classical prototype adenovirus 3. Similar precipitin patterns obtained in homologous and heterologous reactions by immunodiffusion suggested a similarity between the smaller particle and an unidentified agent isolated without adenoviruses from blood clots from overt cases of hepatitis. With the present evidence, it was not possible to relate the smaller agent to adeno-associated viruses; however, its similarity to an agent isolated from blood of overt cases implies a possible relationship with hepatitis. The continued recovery of the variant strain of adenovirus type 3 from patients with hepatitis, although at relatively low rates of isolation, suggested a possible undetermined relation to the disease.
Biohazard Hood to Prevent Infection During Microbiological Procedures
Authors: Coriell Lewis L. , Mcgarrity Gerard J.
Published: December 2020

A microbiological hood was designed to reduce the danger of airborne infection of laboratory workers. The hood uses absolute filters to deliver sterile air in a laminar flow to the work area. An air curtain across the hood opening permits easy access but separates the worker from aerosols produced in the hood, and protects material inside the hood from contamination by room air. Tests with bacterial and viral aerosols showed that the air curtain is at least 99.96% effective in preventing airborne particles from entering the work area.
Value and Interpretation of Serological Tests for the Diagnosis of Cryptococcosis
Authors: Kaufman Leo , Blumer Sharon
Published: December 2020

Maximal serological diagnosis of cryptococcosis may be accomplished through the concurrent use of three tests: the latex agglutination (LA) test for cryptococcal antigen, and the indirect fluorescent antibody (IFA) and tube agglutination (TA) tests for
Cryptococcus neoformans
antibodies. These tests were applied to 141 serum and cerebral spinal fluid specimens from 66 culturally proven cases of cryptococcosis and to 42 sera from normal subjects and from patients with other systemic mycotic diseases. The LA test was sensitive and completely specific; of the sera from proven cases, 55% were positive. With the TA test, 37% of the specimens were positive and the test was highly specific. With the IFA test, 38% of the specimens were positive and the test appears to be the least specific of the three. Cross-reactions were most evident with blastomycosis and histoplasmosis case sera. When the three tests were used concurrently, 87% of the cryptococcosis case specimens were positive and permitted a presumptive diagnosis of
C. neoformans
infections in 61 (92%) of the 66 patients whose specimens were examined.
Method for Microbiological Testing of Nonsterile Pharmaceuticals
Authors: Bühlmann Xaver
Published: December 2020

A method for testing nonsterile pharmaceutical preparations for their microbial content is described. As far as possible, only solid culture media were used to obtain quantitative results. Aqueous and water-soluble products were tested with membrane-filter techniques. Nonfilterable products were first emulsified or suspended and the homogenate was used for examination. In both procedures, the total number of colonies is determined for aerobic bacteria and fungi. Tests for certain undesirable microbial groups were conducted with selected media. The method described is applicable for finished products, bulk products, raw materials, and active ingredients.
Growth and Destruction of
Salmonella typhimurium
in Egg White Foam Products Cooked by Microwaves
Authors: Baldwin Ruth E. , Cloninger Marion , Fields M. L.
Published: December 2020

Currently, in both home and institutional food preparation, attempts are being made to produce high quality foods with a minimum of time and effort. Research is being carried out to develop equipment capable of cooking foods in a fraction of the time required by conventional methods; as a result, the problem arises as to the bacteriological safety of these products. We investigated the microbiological aspects of lemon and chocolate foam pies before and after cooking by microwaves for less than 2 min. Pies prepared with sterile equipment under sanitary conditions were inoculated with washed cells from a 24-hr broth culture of
Salmonella typhimurium
and were incubated for 24, 48, and 72 hr at 33 C. The same procedures were followed in model systems to determine the effects of various sugar and
p
H levels on the survival of
S. typhimurium
. No
S. typhimurium
was detected in inoculated cooked or uncooked lemon pies by the plating method; with the Lactose Broth pre-enrichment method, survivors were detected in lemon pies immediately after preparation. After electronic cooking, no survivors were detected in lemon pies by plate counts, whereas cells were recovered from chocolate pies by the Lactose Broth method. Both chocolate and lemon pies had lower counts throughout the 72-hr incubation period than the model systems compared to them. With the model systems, at
p
H 7.3, media containing sugar inhibited the growth of
S. typhimurium
but did not cause a significant reduction in counts during the incubation times studied. At
p
H 3.7, media without sugar yielded no cells with the Lactose Broth pre-enrichment method after 48 hr of incubation, whereas media with sugar were not sterile until after 72 hr of incubation. Apparently, the presence of sugar in the medium had a protective influence which made the lethal effect of the low
p
H less severe.
Thermostability of Antigens Associated with Serotype of
Rhizobium japonicum
Authors: Means Ura Mae , Johnson Herbert W.
Published: December 2020

The antigens associated with serologically distinct strains of
Rhizobium japonicum
were found to differ in heat sensitivity. Cell preparations from 4 out of 12 strains retained agglutinability, and 1 out of 5 retained antigenicity after they were heated to 120 C. Antigenicity was reduced in most strains after heating to 100 C for 30 min, but agglutinability was not affected by this treatment. This suggests that the antigens are protein-polysaccharide-lipid complexes described for O-type antigens. Cells of strain 46, however, retained both agglutinability and antigenicity after heating to 120 C for 1 hr, and thus a protein in its structure seems improbable. Antigens associated with bacteria from soybean nodules responded to heat treatment in essentially the same manner as those from the same strain grown in nutrient broth. Certain serotypes showed a tendency to agglutinate spontaneously. A heat treatment of 100 C for 30 min, to remove nodule debris and destroy certain blocking antigens, did not interfere with the agglutination reaction. Live cells induced antiserum in rabbit to a higher titer than did heat-treated cells.
Antibiotic Susceptibility of Anaerobic Ruminal Bacteria
Authors: Fulghum Robert S. , Baldwin Beverly B. , Williams Phletus P.
Published: December 2020

This study demonstrated that 15 species of ruminal bacteria with no previous history of contact with antibiotics are susceptible to bacitracin, chloramphenicol, chlortetracycline, erythromycin, novobiocin, oleandomycin, oxytetracycline, penicillin, tetracycline, tylosin, and vancomycin. A number of the species were not inhibited by kanamycin, neomycin, polymyxin, and streptomycin. The data suggest that antibiotic-resistant cells occur within susceptible cultures of these species.
Streptococcus bovis
FD-10 and a nonruminal anaerobe,
Bacteroides melaninogenicus
BE-1, showed similar antibiotic susceptibilities.

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Fig. 1
Plate-Dilution Frequency Technique for Assay of Microbial Ecology
Authors: Harris R. F. , Sommers L. E.
Published: December 2020

The plate-dilution frequency technique described facilitates simultaneous enumeration of a wide range of physiologically different microorganisms in complex systems with a precision comparable to dilution tube (most probable number) methods. Replicate microsamples are inoculated from each member of a dilution series onto areas delineated on plates of prepoured solid media; the plates are incubated, and the occurrence of growth or specific biochemical transformation is recorded for each inoculated area. Microbial enumeration is accomplished by reference to appropriate tables. Details of the experimental procedures are described, and tables are presented from which microbial numbers with 95% confidence limits can be obtained and compared for significant difference directly for 10-fold and 4-fold dilution series. Results of experiments in which microbial populations were estimated simultaneously by the plate-dilution frequency and conventional plate count methods are compared. The potential of the technique for broad-spectrum microbial assay is also discussed.

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Fig. 1
Effect of Temperature and Gas Velocity on the Dry-Heat Destruction Rate of Bacterial Spores
Authors: Fox Kenneth , Pflug I. J.
Published: December 2020

Spores of
Bacillus subtilis
were dried in vacuo for use in dry-heat thermal destruction tests. Survivor curve tests were conducted in a specifically designed dry-heat oven. This oven provided accurate temperature control and permitted air or nitrogen to be passed over the spores during the lethal treatment. Experiments were carried out at various flow rates of the two gases (air and nitrogen) and various temperatures, and the data were expressed as survivor curves from which the decimal reduction time (
D
value) was obtained. Linear regression analysis methods were used to compute the slope of the survivor curves. The results indicated that as the flow rate of gas is increased, the effect of temperature on the destruction rate of the spores is lessened, the
z
value becoming very large. It is believed that the higher flow rates of dry gas cause greater dehydration of the spores and that spore moisture loss is one of the major factors in determining the dry-heat thermal destruction rate of bacterial spores.

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Fig. 1

Fig. 2
In Vivo Antiviral Properties of Biologically Active Compounds
Authors: Sidwell Robert W. , Dixon Glen J. , Sellers Sara M. , Schabel Frank M.
Published: December 2020

The in vivo anti-influenza virus and antivaccinia virus activity of 156 biologically active compounds was determined. One of two criteria was used for evaluating activity against the influenza virus. The criteria were increase in survivor number and mean survival time, and reduction in virus-induced lung consolidation in treated, infected Swiss mice. Increase in survivor number and mean survival time were the criteria for evaluation of antivaccinia virus activity. Several drug doses were tested against two virus concentrations to demonstrate antiviral activity more clearly. Two compounds were considered significantly active against the influenza virus: DL-noformicin (NSC 72942) and amantadine hydrochloride (NSC 83653). Eleven compounds had reproducible activity against vaccinia virus: isatin-β-thiosemicarbazone (NSC 721), 6-azauracil (NSC 3425), 9-α-fluoro-2α-methylhydrocortisone 21-acetate (NSC 12601), 5-[bis(2-chloroethyl)amino]uracil (NSC 34462), 5-iodo-2′-deoxyuridine (NSC 39661), streptonigrin (NSC 45383),
N
-methylisatin β-thiosemicarbazone (NSC 69811), cytovirin (NSC 91770), 9-β-D-arabinofuranosyladenine (NSC 404241), and 5-(mercaptomethyl)uracil (NSC 529351).
Large-Scale Transformation of Steroids by Fungal Spores
Authors: Singh Kartar , Sehgal S. N. , Vezina Claude
Published: December 2020

Spores of
Aspergillus ochraceus
and
Septomyxa affinis
were produced on a large scale by surface sporulation on moist wheat bran and barley. 11α-Hydroxylation of progesterone and Reichstein's compound S by spores of
A. ochraceus
and 1-dehydrogenation of compound S by spores of
S. affinis
were carried out in 5-liter fermentors. It was shown that, above a certain minimum, increase in aeration and agitation did not significantly affect steroid conversion. The industrial feasibility of the spore process was further demonstrated by 11α-hydroxylation of 6α-fluoro-16α,17α-dihydroxypregn-4-ene-3,20-dione in a modified 200-gal stainless-steel vessel with spores of
A. ochraceus
. Strict aseptic conditions are not necessary, either during harvesting of spores or during steroid transformation.
Nitrite-induced Germination of Putrefactive Anaerobe 3679h Spores
Authors: Duncan Charles L. , Foster E. M.
Published: December 2020

Sodium nitrite alone has been shown to stimulate germination of PA 3679h spores. The process was accelerated by using increased concentrations of sodium nitrite, a low
p
H, and a high temperature of incubation. At low concentrations of nitrite (0.01 to 0.2%), the delay of 36 to 48 hr occurred before germination commenced at 37 C. However, with 3.45% nitrite at 45 C and
p
H 6.0, most of the spores germinated within 1 hr. At
p
H 7.0, the germination rate decreased markedly, and at
p
H 8.0 it was nil. The greatest acceleration in germination rate occurred near 60 C. Hydroxylamine was completely inhibitory to nitrite-induced germination. Sodium nitrite, in turn, inhibited germination by
l
-alanine, the degree of inhibition being influenced by nitrite concentration and
p
H.
Antibacterial Action of Essential Oils of
Artemisia
as an Ecological Factor
Authors: Nagy Julius G. , Tengerdy Robert P.
Published: December 2020

Rumen microorganisms of wild and captive deer were subjected to increasing amounts of volatile oils. The oils had a marked antibacterial effect on the rumen bacteria when the concentration reached approximately 16 μliters of oil per 10 ml of rumen fluid nutrient broth. The gross reactions of rumen bacteria obtained from wild, as well as captive, deer to the volatile oils seemed to be of the same magnitude; thus no adaptation by the bacteria to the oils was apparent.
Comparison of Microbial Contamination Levels Among Hospital Operating Rooms and Industrial Clean Rooms
Authors: Favero Martin S. , Puleo John R. , Marshall James H. , Oxborrow Gordon S.
Published: December 2020

Microbial contamination in industrial clean rooms was compared quantitatively and qualitatively with that of hospital operating rooms. The number of aerobic mesophilic microorganisms which accumulated on stainless-steel strips exposed for periods up to 21 weeks to the intramural air of four operating rooms was at least 1 log higher than the accumulation on strips exposed in four clean rooms, and was essentially the same as that found in two factory areas. Volumetric air samplings showed that there were significantly higher numbers of airborne viable particles per cubic foot of air in operating rooms than in industrial clean rooms. In contrast to clean rooms, where most of the airborne contaminants were those associated with human hair, skin, and respiratory tract, the hospital operating rooms showed a very high level of microorganisms associated with dust and soil.
Direct Comparison of the
N
-Acetyl-L-Cysteine-Sodium Hydroxide and the Trisodium Phosphate Digestion Methods for the Culture of Mycobacteria
Authors: Martin Margaret E. , Horton Charles L. , Sheffner A. Leonard , Solomon James D.
Published: December 2020

Comparison of sputum digestion procedures utilizing acetylcysteine-sodium hydroxide (AC) and trisodium phosphate for the isolation and culture of mycobacteria indicated that the AC procedure provides faster growth, thus permitting the earlier detection of positives. Also, in untreated patients and those in whom treatment has been recently instituted, the number of positives was slightly larger with the use of the AC procedure. However, of greater interest was finding that the AC procedure provided a larger quantity of positive cultures with sputum from subjects who had been intensively treated with antimicrobials and other drugs. Contamination was higher with the AC procedure, but when the sputa were diluted 1:10 this interference due to contamination was decreased.
Fermentation Rates of Grape Juice
Authors: Ough C. S. , Kunkee R. E.
Published: December 2020

Microbiological analysis showed that juices from white grapes had less biotin than juices from red grapes. The biotin content of the juices of some varieties was significantly different from that of other varieties. We did not note any regional effects on the biotin content of the juices. Biotin content of the Cabernet Sauvignon grapes increased significantly with maturity, whereas the biotin content of a white variety did not. The biotin content, with the total nitrogen, can be used to estimate indirectly the yeast growth potential and hence to predict the fermentation rate of the juice. About 84% of the rate variation can be accounted for by the calculated regression equations.
A New Plating Medium for the Isolation of Enteric Pathogens
Authors: King Sylvia , Metzger William I.
Published: December 2020

During this study, 2,855 stool specimens from patients at Cook County Hospital were cultured for enteric pathogens. Hektoen Enteric Agar (HE) was compared with E M B and S S Agars by replicate samplings with both direct and indirect methods.
Shigella
species were recovered more than twice as often on HE Agar as on S S Agar by both methods. With the direct method only, out of 98
Shigella
isolated, 97 were isolated from HE Agar, 74 were recovered from E M B Agar, and 40 were found on S S Agar. In addition, HE yielded better isolation of
Salmonella
strains than did S S or E M B by either direct or indirect methods. The greater efficiency of HE medium is discussed with respect to colonial recognition of enteric pathogens.
Antifungal Activity of Isothiocyanates and Related Compounds
Authors: Drobnica Ľ. , Zemanová M. , Nemec P. , Antoš K. , Kristián P. , Martvoň A. , Závodská E.
Published: December 2020

This paper presents the results of a study on the antifungal activity of isothiocyanates—derivatives of biphenyl (group “A”), of stilbene (“B”), of azobenzene and benzeneazonaphthalene (“C”), of naphthalene (“D”), and of further polycondensed aromatic hydrocarbons (“E”). From a total of 48 investigated compounds, antifungal activity was observed only in A and D group compounds. B, C, and E group derivatives are extremely insoluble in water, and the molecules are very large; as a result, they probably cannot pass into spores or mycelium of fungi. Thus, the —NCS group cannot manifest its reactivity.
Effect of Bacterial Cell Moisture on the Sporicidal Activity of β-Propiolactone Vapor
Authors: Hoffman Robert K.
Published: December 2020

The activity of a vapor-phase disinfectant is usually expressed in terms of the atmospheric relative humidity (
RH
). This study shows that, in β-propiolactone (
BPL
) vapor disinfection, the important factor is really the moisture content and location of water in the cell, and not necessarily the atmospheric
RH
. Previous studies revealed that only about 50% of the bacterial spores equilibrated to 45%
RH
were killed when exposed to the same
RH
to
BPL
vapor. On the other hand, all the spores equilibrated to and then exposed at 75%
RH
to
BPL
were readily killed. The present study shows that spores equilibrated to 98%
RH
are readily killed by
BPL
at 45%
RH
, but only 99% of the spores equilibrated to 75%
RH
are killed by
BPL
at 45%
RH
. Also, in order to be killed, desiccated spores must be exposed to
BPL
at higher humidities than would be required if the spores had not been previously desiccated.
Comparison of the Action of Ampicillin and Benzylpenicillin on Enterococci In Vitro
Authors: Sonne Minetta , Jawetz Ernest
Published: December 2020

The bactericidal activity of benzylpenicillin and ampicillin on 21 strains of enterococci was evaluated and compared to the activity of these drugs in combination with streptomycin (20 μg/ml). On a weight basis, ampicillin was about twice as effective as benzylpenicillin. Neither of the drugs was rapidly and completely bactericidal for any of the 21 strains of enterococci when used alone. The addition of streptomycin greatly enhanced the early bactericidal rate achieved with any given amount of either penicillin and permitted the elimination of viable organisms in vitro. These results suggest that, for the time being, combined antibiotic therapy might be desirable in enterococcus endocarditis and that ampicillin, although more effective than benzylpenicillin, should not be relied upon as a single drug in that disease.
Drug Resistance as Influenced by Inactivated Sensitivity Discs
Authors: Griffith Lewis J. , Mullins C. G.
Published: December 2020

Reports of staphylococci resistant to the semisynthetic penicillins stimulated a study of the factors influencing the stability of the drugs in discs. The behavior of penicillin G, methicillin, oxacillin, cloxacillin, and cephalothin discs under different humidity and temperature conditions is described. Humidity was found to be the most significant factor in drug inactivation. Storage of discs in a vacuum desiccator at -20 C provides maximal antibiotic stability.
Sensitivity of an Enrichment Culture Procedure for Detection of
Clostridium botulinum
Type E in Raw and Smoked Whitefish Chubs
Authors: Pace Paul J. , Wisniewski Henry J. , Angelotti Robert
Published: December 2020

The sensitivity of an enrichment culture procedure for detecting
Clostridium botulinum
type E in whitefish chubs (
Leucichthys
sp.) was assayed. Data demonstrated that fish inoculated with 10 or more viable
C. botulinum
spores regularly develop specifically neutralizable enrichment cultures. Mild heat treatment (60 C, 15 min) substantially reduced the sensitivity of enrichment culturing. This effect was particularly noticeable in the culturing of fish which harbored fewer than 10 spores each. Evidence is presented which indicates that sensitivity of enrichment, without heat, approaches the level of one spore per fish. Smoked whitefish chubs, containing from one to several hundred spores each, were examined for toxin content after storage at 5, 10, 15, and 28 C for as long as 32 days. The lowest temperature at which detectable toxin was produced was 15 C. This occurred in 1 of 10 fish incubated for 14 days.
C. botulinum
was regularly recovered, by enrichment culture, from fish inoculated with small numbers of spores, even though toxin was not detected by direct extraction of incubated fish. Persistence of
C. botulinum
type E spores was observed to decline with an increase in the temperature and time at which inoculated fish were stored.
In Vitro Lactate Metabolism by Ruminal Ingesta
Authors: Satter L. D. , Esdale W. J.
Published: December 2020

Ruminal ingesta (300 ml) obtained from a fistulated cow fed alfalfa hay (H), 3.6 kg of grain mixture with corn silage fed ad libitum (S), 2.5:1 grain-alfalfa hay mixture (G), or a 2.5:1 grain-alfalfa hay mixture providing 545 g of sodium and calcium lactate daily (L) were incubated for 8 hr with nonpolymerized sodium lactate or 17% polymerized lactic acid neutralized to
p
H 6.7. Polymerization had no effect on the rate of lactate utilization. The initial rates of lactate metabolism for the H, G, S, and L ingesta were 0.72, 0.95, 1.8, and 3.4 meq per 100 ml of rumen fluid per hr, respectively. Lactate-
2
-
14
C
was incubated for 4 hr with each type of ruminal ingesta. Of the label recovered in the volatile fatty acids (VFA), 74.1, 61.2, 49.3, and 38.9% was recovered in acetate, and 9.4, 19.8, 23.3, and 51.9% was recovered in propionate with H, G, S, and L ingesta, respectively. The balance of label was distributed between butyrate and valerate. The titratable VFA did not follow this pattern of production. With the hay ingesta, lactate metabolism resulted in a net loss of acetate and a large increase in butyrate. Little propionate was produced. The G, S, and L ingesta metabolized lactate to yield progressively more propionate and less butyrate. Evidence was gathered to suggest that acetate was the primary end product of lactate metabolism but that oxidation of lactate to pyruvate dictated the synthesis of butyrate from acetate to maintain an oxidation-reduction balance. It was noted that acetate and butyrate production from lactate was
p
H-dependent, with acetate production maximal at
p
H 7.4 and butyrate at 6.2. Propionate production was largely unaffected within this
p
H range.
Studies on Versicolin, a New Antifungal Antibiotic from
Aspergillus versicolor
Authors: Dhar Amiya K. , Bose Sushil K.
Published: December 2020

Versicolin is a new antifungal agent isolated from the culture broth of a new strain of
Aspergillus versicolor
. The antibiotic is specifically active against pathogenic fungi, particularly
Trichophyton rubrum
which causes 90% of the skin infections occurring in Calcutta and eastern India.
Turbidimetric Assays: the Antibiotic Dose-Response Line
Authors: Kavanagh Frederick
Published: December 2020

Several antibiotics reduced growth of bacteria without killing them when present in the range of concentrations of significance in assaying. The reduction in growth rate was linearly related to concentration of antibiotic. From this fact may be derived an equation of the form log
N
=
A
-
BC
where
N
is the concentration of bacteria at the end of the incubation period,
C
is the concentration of antibiotic, and
A
and
B
are constants. This equation is used to guide the selection of the best range of concentrations of unknown for assay and to show the large influence of variations of temperature upon an assay.
Sporicidal Activity of Sodium Hypochlorite at Subzero Temperatures
Authors: Jones Lynwood A. , Hoffman Robert K. , Phillips Charles R.
Published: December 2020

Sodium hypochlorite was an excellent disinfectant at low temperatures. With the addition of ethylene glycol to prevent freezing, hypochlorite solutions at low free available chlorine concentrations, were effective against
Bacillus subtilis
var.
niger
spores from 0 to -40 C. The effectiveness of this decontaminant was influenced by temperature,
p
H, and concentration, with
p
H 7.2 the optimum for decontamination at all temperatures and concentrations.
Effect of Ion Concentration on the Rupture and Survival of
Azotobacter
Cysts
Authors: Goldschmidt Millicent C. , Wyss O.
Published: December 2020

The ability of ethylenediaminetetraacetic acid (EDTA) and dipicolinic acid (DPA) to rupture
Azotobacter
cysts was directly related to the molarity of the reaction mixture. Cysts were not ruptured at concentrations above 0.15
m
(NaCl or phosphate). These higher salt concentrations prevented the formation of metallo:EDTA (or DPA) chelate complexes. Sudden shifts in the tonicity of NaCl or phosphate mixtures induced cyst rupture in the absence of EDTA. The effect of these mechanisms on the survival and germination of
Azotobacter
cysts in the soil is discussed.
Measurement of Three Antibiotics (Penicillin, Cephalothin, and Chloramphenicol) When Present Together in Mixtures
Authors: Sabath Leon D. , Loder P. Bronwen , Gerstein Deborah A. , Finland Maxwell
Published: December 2020

Benzylpenicillin, cephalothin, and chloramphenicol were measured individually and quantitatively when present together in mixtures at concentrations found in patients. The assay depended on the selective inactivation of two of the antibiotics, permitting the third to be assayed as if present alone. Agar seeded with a chloramphenicol-resistant, penicillinase-negative
Staphylococcus aureus
was used for a cylinder-plate assay of appropriately diluted fluid to determine the activity of either benzylpenicillin or cephalothin after either β-lactamase inactivation of the former or ultraviolet light inactivation of the latter. Chloramphenicol was assayed with
Sarcina lutea
after appropriate β-lactamase inactivation of both cephalothin and benzylpenicillin. Fluids containing various amounts of the three antibiotics were assayed by this method with less than 8% error. Procedures that fail to measure each antibiotic individually may give larger errors.
In Vitro Antimicrobial Activity and Human Pharmacology of Cephaloglycin
Authors: Applestein Jeffery M. , Crosby E. Brown , Johnson Warren D. , Kaye Donald
Published: December 2020

Serum and urine concentrations of cephaloglycin (an orally absorbed derivative of cephalosporin C) were determined in normal volunteers and in patients. The in vitro activity of cephaloglycin was also studied. All strains of group A streptococci (
Streptococcus pyogenes
) and
Diplococcus pneumoniae
were inhibited by 0.4 μg of cephaloglycin per ml. Eighty per cent of the
Staphylococcus aureus
strains and about 50% of the
Escherichia coli
and
Proteus mirabilis
strains were inhibited by 1.6 μg of cephaloglycin per ml.
Klebsiella-Aerobacter
species were more resistant to cephaloglycin and 12.5 μg per ml was required to inhibit 70% of these strains. When single doses of 250, 500, or 1,000 mg of cephaloglycin were administered to fasting volunteers, a peak serum concentration of at least 0.5 μg per ml was achieved. A full breakfast did not interfere with absorption of cephaloglycin. Probenecid enhanced both the peak serum concentration and the duration of antibiotic activity in the serum. Serum concentrations of cephaloglycin were even higher in patients who were receiving repeated doses. The peak serum concentrations of cephaloglycin in all volunteers and patients were adequate to inhibit all strains of group A streptococci and
D. pneumoniae
. Many of the peak serum concentrations were adequate to inhibit some strains of
S. aureus, E. coli
, and
P. mirabilis
. Urine levels of cephaloglycin were high enough in all volunteers and patients to inhibit more than 90% of the
E. coli
and
P. mirabilis
strains and over 70% of the strains of
Klebsiella-Aerobacter
.
Formation of Desacetylcephalosporin C in Cephalosporin C Fermentation
Authors: Huber F. M. , Baltz R. H. , Caltrider P. G.
Published: December 2020

The origin of desacetylcephalosporin C in cephalosporin C fermentation broths was investigated. Esterase activity was detected in cell-free extracts of
Cephalosporium acremonium
, but these extracts failed to deesterify cephalosporin C. When cephalosporin C was added to sterile and inoculated fermentation media, the antibiotic decayed at nearly identical rates. The formation of desacetylcephalosporin C during the fermentation was measured by quantitative chromatography and by the incorporation of valine-
1
-
14
C
into the molecule. The rate constants obtained from the results of these experiments were equivalent to those for the decay of cephalosporin C in sterile and inoculated media. The data demonstrate that desacetylcephalosporin C is produced by nonenzymatic hydrolysis of cephalosporin C.
Numerical Taxonomy of Catalase-negative Cocci Isolated from Frozen Vegetables
Authors: Splittstoesser D. F. , Mautz Marilyn , Colwell R. R.
Published: December 2020

Taxonomic data for 135 cultures of bacteria isolated from frozen snap beans and whole kernel corn were analyzed by computer. Of the isolates, 79% were grouped into five major clusters. Two of the groups consisted of leuconostocs, whereas the other three contained homofermentative types. The intergroup similarities suggested a generic level of similarity. Feature frequencies for the groups were calculated, and properties of the different groups are presented. Many of the isolates differed from described species.
Assay for Aflatoxin Production by the Genera
Aspergillus
and
Penicillium
Authors: Mislivec Philip B. , Hunter J. H. , Tuite John
Published: December 2020

A total of 260 isolates, including 43 species of
Penicillium
and 7 species of
Aspergillus
, were screened for their ability to produce aflatoxin on rice. Chloroform extracts were analyzed by thin-layer chromatography. None of the isolates produced aflatoxin. Certain species of
Penicillium
produced fluorescent substances that either were similar in

R
F

or were of similar color to B and G aflatoxins. These substances were subsequently proved not to be aflatoxin by two-dimensional chromatography, by reaction with iodine fumes, or by both methods.
Rapid Sulfonamide Disc Sensitivity Test for Meningococci
Authors: Bennett John V. , Camp Helen M. , Eickhoff Theodore C.
Published: December 2020

Minimal inhibitory concentrations (MIC) of 90 strains of
Neisseria meningitidis
were determined by a plate dilution technique that employed twofold changes in concentrations of sulfadiazine. The geometric mean of three MIC determinations on each strain was correlated with inhibition zones produced by a 300-μg sulfathiazole disc. The linear relationship between the logarithm of the geometric mean MIC values and the zone diameters was highly significant. Strains were separated into sensitive and resistant populations by both test procedures. Quantitative criteria for interpreting the sensitivity of a strain by the disc test were established.
Use of the Antiserum-Agar Plate Technique for Specific Identification and Isolation of
Pasteurella pestis
Authors: Albizo Johnnie M. , Surgalla Michael J.
Published: December 2020

Pasteurella pestis
colonies were specifically identified on antiserum-agar plates used for primary culture of tissues from experimentally infected guinea pigs. Both selective and nonselective antiserum-agar plates were used to identify
P. pestis
from guinea pigs kept at 22 C for periods up to 4 days after death from plague. Colonies identified as
P. pestis
on selective and nonselective antiserum-agar plates, by the appearance of precipitin rings following brief chloroform vapor treatment, remained viable and were subsequently purified on nonselective antiserum-agar plates. Isolates obtained in this manner were uniformly lethal when injected into mice and guinea pigs, and conformed to standard laboratory criteria for
P. pestis. P. pestis
was identified on selective antiserum-agar plates from the spleens of all guinea pigs killed by the isolates, and from a large majority of the mice. The practical value and confirmative nature of the method were demonstrated.
Method for Measuring Microbial Growth in Rumen Content
Authors: Walker D. J. , Nader C. J.
Published: December 2020

Radioactive sodium sulfide was used to label the sulfide pool of rumen contents in vitro. Microbial protein synthesis was calculated from the size and rate of dilution of label in the sulfide pool, and from the radioactivity incorporated into protein together with a conversion factor specifying the nitrogen-sulfur ratio determined for microbial protein. The microbial cell yield, calculated on the basis of the adenosine triphosphate (ATP) available from fermentation, was 13 to 14 g (dry weight) per mole of ATP, which is in good agreement with the values obtained for pure cultures of bacteria. Calculation of microbial protein yield per kilogram of ration agreed fairly well with previous estimates for similar rations.
Method for the Detection and Quantitative Assay of Cephaloglycin and Its Biologically Active Metabolites
Authors: Hoehn Marvin M. , Pugh Charles T.
Published: December 2020

Thin-layer and paper chromatographic systems were used to detect and determine the concentration of cephaloglycin and its biologically active metabolites in serum and urine. Data are presented on the procedures, solvent systems, and specific techniques used in this evaluation.
Phage Typing Reactions on
Brucella
Species
Authors: Jones Lois M. , Merz G. S. , Wilson J. B.
Published: December 2020

The nature of the phage typing reactions on
Brucella
species was determined by rates of adsorption and infection, one-step growth experiments, and susceptibility to lysis from without. The highest rates of adsorption and infection were obtained on smooth
B. abortus
cultures, and large clear plaques were produced. One or a few phage particles per
B. neotomae
cell killed about one-half of the cells, but some went through an infective cycle and released mature phage that resulted in production of small clear plaques. With
B. suis
, more phage particles per cell were required to kill, replication did not occur, and plaques were not observed. Still greater numbers of phage particles were required to cause some inhibition of growth of
B. melitensis
lawns. Rough
Brucella
cultures and species, such as
B. ovis
and
B. canis
, were not affected by the highest concentrations of phage.
B. abortus
cultures of intermediate colonial morphology adsorbed phage, but only a few infected cells (after a delayed latent period) released mature phage. An infected culture or colony appeared normal until spontaneous phage mutants appeared which could penetrate the cell wall more effectively than the parent phage. The mutant phage multiplied more rapidly, and the colony changed to a sticky white form.