bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Macrocomplement and Microcomplement Fixation Techniques Used in Fungus Serology
Authors: Kaufman Leo , Hall Elmer C. , Clark Maxine J. , McLaughlin David
Published: December 2020

A comparative evaluation was performed on the micro- and macrocomplement fixation (CF) tests that are used as standard procedures in the serodiagnosis of blastomycosis, coccidioidomycosis, and histoplasmosis. Tests with 937 sera from suspected and culturally proven cases of these diseases against yeast-form antigens of
Blastomyces dermatitidis
and
Histoplasma capsulatum
and against the soluble antigens, coccidioidin and histoplasmin, revealed that the microtiters were within ± 1 dilution of the macrotiters in 83 to 93% of the sera. Tests on randomly coded quality control sera revealed the microform of the CF test to be highly reproducible. Our studies indicate that the results obtained by the two tests have similar diagnostic and prognostic interpretations. Because of the sensitivity, reproducibility, economy, and ease of performance, the microtest is highly recommended for use in fungus serology.
Hydrogen Sulfide-Negative Variant of
Citrobacter
Authors: Washington John A. , Yu Pauline K. W. , Martin William Jeffery
Published: December 2020

The characteristics of 25 hydrogen sulfide-negative strains of
Citrobacter
were studied. The majority of isolates were from the respiratory tract and usually were of indeterminate clinical significance. All strains were highly susceptible to polymyxin B, gentamicin, kanamycin, nalidixic acid, and nitrofurantoin.
Immunofluorescent Identification of Type 12 Group A Streptococci
Authors: Vincent William F. , Lisiewski Kathleen J. , Ullmann William W.
Published: December 2020

The fluorescent antibody (FA) conjugate prepared by labeling streptococcal M type 12 antibody with fluorescein isothiocyanate was found to exhibit considerable nonspecific FA staining with other group A M-serotypes. The cross-reactions could be reduced sufficiently or eliminated by the addition of adsorbed homologous blocking serum (AHB) but not by preimmune serum. The AHB was prepared by adsorbing type 12 antiserum with untreated homologous cells. Comparative staining with unblocked and AHB-blocked FA conjugates enabled type 12 streptococci from clinical specimens to be rapidly and accurately identified.
Potential of Kidney Cell Cultures from Nonhibernating Thirteen-Lined Ground Squirrels (
Citellus tridecemlineatus
) for Virus Propagation
Authors: Cashon Gary W. , McKenna John M. , Cashon Carol S.
Published: December 2020

Kidney cells were cultured in vitro from nonhibernating thirteen-lined ground squirrels (
Citellus tridecemlineatus
). These primary ground squirrel kidney cultures were tested for the ability to support the replication of 13 viruses representing nine virus groups. The cultures were shown to be susceptible to every virus tested, either by an increase in infectious virus or by the cytopathic effect produced.
Pyelonephritis Therapy in Rats: Random Association with Excreted Urinary Antibacterial Activity
Authors: Burrous S. E. , Freedman R. , Chamberlain R. E. , Basson R. P.
Published: December 2020

In vitro activities or excreted urinary activities of 56 generic and experimental drugs against two organisms commonly associated with human pyelonephritis,
Escherichia coli
and
Proteus mirabilis
, are not correlated with the in vivo activities of these compounds as measured by reduction of viable organisms in kidneys in experimental pyelonephritis.
Enterotoxigenicity of
Staphylococcus aureus
Cultures Isolated from Acute Cases of Bovine Mastitis
Authors: Olson J. C. , Casman E. P. , Baer E. F. , Stone Judith E.
Published: December 2020

To determine whether staphylococci causing bovine mastitis are potential causes of human intoxications, 142 cultures identified as etiological agents of acute cases and 18 cultures causing chronic cases of staphylococcal mastitis were obtained from investigators in the United States and Canada, examined microscopically, and tested for carbohydrate utilization, terminal
p
H, catalase, coagulase, egg yolk hydrolysis, gelatin hydrolysis, cytochrome oxidase, urease production, nitrate reduction, micrococcal nuclease, phage type, and enterotoxin production. Three cultures were not confirmed as
Staphylococcus aureus.
Of the 157
S. aureus
cultures, 23 produced staphylococcal enterotoxins. Although a direct relationship between staphylococcal mastitis and outbreaks of staphylococcal food poisoning was not proved, results indicated that staphylococcal infections of the bovine mammary gland represent a significant reservoir of enterotoxigenic strains of
S. aureus.
Growth of Rio Bravo Virus in Cell Cultures
Authors: Wilhelm Alan R. , Gerone Peter J.
Published: December 2020

The growth of Rio Bravo virus (RBV) in eight cell culture systems was studied. Highest yields of virus were produced in BHK-21 (C13), L, and Vero cell lines, but L cells were resistant to low doses of virus. LLC-MK
2
, HeLa, and human embryo skin cells produced moderate amounts of virus, but FL amnion and primary chick embryo fibroblasts supported little virus growth. Virus was rapidly inactivated by exposure to
p
H values below 7.0. Single-cycle growth in BHK-21, L, and LLC-MK
2
cell monolayers was characterized by a latent period of about 12 hr followed by rapid virus production that peaked at 36 to 48 hr. Vero cell cultures can remain chronically infected with RBV for more than 100 days. Such cultures show evidence of cell destruction, and their supernatant fluids contain virus at 10
4
to 10
5
log
10
per ml.
Comparative Study of
14
C-Labeled Purified Protein Derivative from Various Mycobacteria
Authors: Landi S. , Held H. R.
Published: December 2020

A study on skin cross-reactivity between stabilized
14
C-labeled mycobacterial antigens, namely tuberculin purified protein derivative (PPD; from
Mycobacterium tuberculosis
), PPD-A (
M. avium
), PPD-Y (
M. kansasii
), PPD-G (
M. scrofulaceum
), PPD-B (
M. intracellulare
), and PPD-F (
M. fortuitum
), has been carried out in groups of guinea pigs sensitized with one of the following heat-killed mycobacteria:
M. tuberculosis, M. avium, M. kansasii, M. scrofulaceum, M. intracellulare
, or
M. fortuitum
. For each type of sensitization, the average response for the corresponding PPD antigen was higher than the average response for any of the other antigens. However, the responses to the heterologous PPD antigens were not necessarily significantly different among themselves, and the significant differences of the heterologous PPD antigens were distributed differently according to the type of sensitization. Therefore,
14
C-PPD antigens skin cross-reacted in guinea pigs essentially in the same manner as reported by others for nonradioactive PPD antigens.
New Water Disinfectant: an Insoluble Quaternary Ammonium Resin-Triiodide Combination that Releases Bactericide on Demand
Authors: Taylor S. L. , Fina L. R. , Lambert J. L.
Published: December 2020

Strongly basic anion-exchange resins form stable, water-insoluble combinations with triiodide ions. The combinations have remarkable antibacterial properties: 3.0 × 10
5
Escherichia coli
cells per ml were killed when passed through a 3.8-g column of commercially available resin treated with triiodide (volume 4 ml after treatment). In an attempt to deplete the resin-triiodide complex, 1.14 × 10
9
E. coli
cells in 15 liters were passed through the column with no significant loss of effectiveness. The antibacterial capabilities of the resin-triiodide columns ranged from 10
6
Salmonella typhimurium
per ml to 1.1 × 10
4
Streptococcus faecalis
per ml.
Staphylococcus aureus
and
Pseudomonas aeruginosa
were also tested and killed at concentrations of 1.8 × 10
4
and 1.3 × 10
5
per ml, respectively. The cells were not filtered from the water. They emerged from the column in nonviable form. This was demonstrated by using
14
C-labeled bacteria. The irreversible nature of the antibacterial action was revealed when attempts to wash the damaged cells did not restore viability.
Lyophilization of Cell-Free Marek's Disease Herpesvirus and a Herpesvirus from Turkeys
Authors: Calnek B. W. , Hitchner S. B. , Adldinger Hans K.
Published: December 2020

Cell extracts of the JM and GA strains of Marek's disease herpesvirus and the FC 126 strain of turkey herpesvirus were lyophilized with various stabilizers. Much higher virus titers were obtained with stabilizer than without stabilizer. Titers increased even further in the case of the Marek's disease virus strains by the addition of a chelating agent, disodium ethylenediaminetetraacetate.
Growth of Mouse L Cells in Shaken Culture and Mengovirus Plaque Formation on L Cells Suspended in Agar
Authors: Slein Milton W. , Logan Gerald F.
Published: December 2020

Procedures are described that require a minimum of equipment and maintenance for growing mouse L cells suspended in liquid medium and for plaquing mengovirus on L cells suspended in agar. Viability of L cells during storage for 1 to 2 hr at relatively high concentrations was better in media at 30 C than at 0 C, as measured by viable counts after growth for 24 hr at 35 C. The number and size of plaques increased with increasing concentration of NaHCO
3
in the agar layers, but the relative difference in plaque size was maintained. Large- and small-plaque-size variants had similar virulence as determined by the rates of viability loss of L cells in liquid suspension cultures.
Identification of a Stimulant for
Lactobacillus casei
Produced by
Streptococcus lactis
Authors: Branen A. L. , Keenan T. W.
Published: December 2020

A compound stimulatory to the growth of
Lactobacillus casei
was isolated from cell extracts of
Streptococcus lactis
, purified, and characterized. The stimulant was identified as a small peptide with a molecular weight of approximately 4,500 daltons. The purified peptide gave negative tests for nucleic acids, phosphorus, glucosamine, and carbohydrates. Sixteen amino acids were detected in acid hydrolysates of this peptide. Serine, proline, glycine, alanine, leucine, and glutamic acid were present in hydrolysates in greatest abundance.
Adsorption of Formaldehyde by Various Surfaces During Gaseous Decontamination
Authors: Braswell James R. , Spiner David R. , Hoffman Robert K.
Published: December 2020

Study of the effect of atmospheric relative humity (RH) on the adsorption of paraformaldehyde-generated formaldehyde gas on various surfaces and the effect of the adsorbed formaldehyde on the death rate of bacterial spores showed that increasing the RH caused a corresponding increase of formaldehyde levels on all surfaces. The amount peaked at 83% RH. The levels obtained at 100% RH were slightly below those at 83% RH. Cotton cloth had a much greater affinity for the gas at all RH than either glass or stainless steel. The death rate of bacterial spores on surfaces containing adsorbed formaldehyde was high for the first hour after removal from the formaldehyde atmosphere but decreased rapidly thereafter. This held true for both cotton and glass surfaces. Also, formaldehyde levels of 15 to 27 μg/ml of nutrient broth caused inhibition of bacterial growth, but levels above 27 μg/ml rendered broth sterile.
Plaque Assay for Pneumonia Virus of Mice
Authors: Shimonaski Gerard , Came Paul E.
Published: December 2020

A plaque assay for the quantitation of pneumonia virus of mice is described. To obtain reproducible plaque formation, proteolytic enzymes had to be incorporated in the overlay medium. The plaque morphology observed in the presence of pancreatin and chymotrypsin was superior to that seen with trypsin. Although the plaque assay was found to be slightly less sensitive than the TCID
50
determination described by Harter and Choppin, it enables cloning of the virus by plaque selection and permits further study of pneumonia virus of mice.
Synergistic False-Positive Coliform Reaction on M-Endo MF Medium
Authors: Schiff L. J. , Morrison S. M. , Mayeux J. V.
Published: December 2020

The reported occurrence of synergistic false-positive coliform reactions on M-Endo MF medium was investigated. The objectives of the study were (i) to isolate populations of bacteria which produced such false-positive reactions, (ii) to determine whether false-positive sheen reactions are a result of synergistic interaction, and (iii) to determine the metabolic intermediates involved in false-positive sheen production. Samples of river water were subjected to coliform analysis by the membrane filter technique with M-Endo MF medium. Suspect sheen-forming colonies were analyzed to determine purity and identity of cultures. Mixed cultures were separated, and individual isolates were examined for sheen production. The isolates not producing a sheen were recombined and tested further for sheen production. Those mixtures reproducing the sheen were characterized biochemically and tested to determine the metabolic intermediates involved. Chromatographic analysis of the metabolites showed that individual isolates produced an assortment of neutral organic compounds including 2-butanone, 2,3-butanedione, formaldehyde, and butyraldehyde, whereas acetaldehyde or propionaldehyde was produced only by the mixed cultures. Tests showed that both propionaldehyde and acetaldehyde could react to produce a sheen on M-Endo medium. The conclusion was reached that synergistic false-positive coliform reactions do indeed occur on M-Endo MF medium.
Aflatoxin B
1
Induction of Lysogenic Bacteria
Authors: Lillehoj E. B. , Ciegler A.
Published: December 2020

A technique for biological verification of aflatoxin B
1
was developed based on toxin-mediated induction of lysis in a lysogenic strain of
Bacillus megaterium
NNRL B-3695. Reduction of culture turbidity was determined at various concentrations of toxin. Incubation of 1.1 × 10
−4
g (dry weight) of cells/ml of growth medium containing 25 μg of B
1
per ml at 37 C reduced initial turbidity 0.20 absorbance units in 4 hr. If the bacterial lysate of the lysogenic strain, after a 2-hr incubation with 25 μg of B
1
per ml, was plated with a sensitive
B. megaterium
strain (NRRL B-3694), plaque-forming units increased approximately 150 times relative to the control. Comparable testing of the effects of aflatoxin on the nonlysogenic, sensitive strain demonstrated that 75 μg of B
1
per ml neither induced lysis nor plaque-forming units. Although induction is not an exclusive property of aflatoxin B
1
, the differential response of the lysogenic and sensitive
Bacillus
strains to B
1
offers a unique and rapid technique for biological verification of the toxin.
Effect of Poly I:C on Experimental Respiratory Infection in Hamsters
Authors: Renis Harold E.
Published: December 2020

The interferon inducer double-stranded polyinosinic acid and polycytidylic acid (poly I:C) was studied in hamsters experimentally infected with parainfluenza 3 virus. Upper intranasal, deep intranasal, or intraperitoneal treatment of hamsters with poly I:C (100 μg/100- to 120-g animal) 24 hr before an upper respiratory infection significantly reduced the virus yields taken 28 hr after infection. Deep intranasal and intraperitoneal treatment with poly I:C greatly decreased the virus titers in the lungs, as measured 48 hr after a deep lung infection with parainfluenza 3 virus; however, the upper respiratory poly I:C treatment was ineffective.
Use of Formalinized Sheep Erythrocytes in the Rubella Hemagglutination-Inhibition Test
Authors: Gupta Jiban D. , Harley John D.
Published: December 2020

Rubella antibody determination by the hemagglutination-inhibition test was effectively simplified by substitution of formalinized sheep red blood cells for avian erythrocytes.
Improved 18-Hour Methyl Red Test
Authors: Barry A. L. , Bernsohn K. L. , Adams A. P. , Thrupp L. D.
Published: December 2020

Standard methods for the methyl red (MR) test are not practical for routine use in clinical laboratories because of the necessarily prolonged incubation period. When read after overnight incubation, the usual MR test is often equivocal or falsely positive. The present study demonstrates the importance of standardizing the total volume of broth, the size of the vessel in which the cultures are incubated, and the density of the inoculum. In very small volumes of broth, cultures are better exposed to atmospheric oxygen, and thus MR-negative organisms tend to revert the initial acidic
p
H much more quickly than in deeper, large-volume broth cultures. In the proposed technique, a single colony was inoculated into a 0.5-ml amount of MR-Voges Proskauer (VP) broth (13- by 100-mm tube), and, after 18 to 24 hr at 37 C, one drop of MR was added. With this technique, the broth cultures produced either a definite red (positive) or yellow (negative) color, whereas various shades of orange were frequently observed when larger volumes of broth were tested after only 1 to 2 days of incubation. With 6.0-ml broth cultures, 18-hr MR tests were totally unreliable, but 18-hr tests in 0.5 ml of broth were comparable to the standard MR test performed after 5 days of incubation and superior to those performed after 48 hr in 6.0-ml broth cultures. With the proposed technique, the MR test can be incorporated readily into the routine scheme for identification of
Enterobacteriaceae
.
Investigation of the Penicillinase Activity in L Colonies of
Staphylococcus aureus
Authors: Rosdahl Vibeke Thamdrup , Vejlsgaard René
Published: December 2020

Penicillinase-producing strains of
Staphylococcus aureus
are transformed into stable L colonies by 70 to 100 subcultures on methicillin-containing medium with a suitable high osmolarity. During transformation, the penicillinase activity is lost. This loss in activity is not the result of only the penicillinase-negative mutants transforming to L colonies. If unstable L colonies are filtered through 0.45-μm membrane filters immediately after transformation, still no penicillinase activity is seen; this is also the case if the filtrated L colonies are reverted into coccal forms. The mechanism responsible for the loss of penicillinase activity is discussed. A loss of the penicillinase plasmid is proposed as the most reasonable explanation.
Effects of Atmospheric Humidity and Temperature on the Survival of Airborne
Flavobacterium
Authors: Ehrlich Richard , Miller Sol , Walker Robert L.
Published: December 2020

The survival of airborne
Flavobacterium
sp. in particle sizes ranging from 1 to 5 μm was significantly influenced by atmospheric temperature. A progressive increase in temperature from −18 to 49 C resulted in increases in death rates of the airborne organism. The lowest death rates were observed in the temperature range of −40 to −18 C, and the highest death rates were observed in the 29 to 49 C range. At 24 C, the survival of airborne
Flavobacterium
did not appear to be significantly affected by relative humidity ranging from 25 to 99%.
Effect of Glucose and Low Oxygen Tension on
l
-Asparaginase Production by a Strain of
Escherichia coli
B
Authors: Boeck L. D. , Squires R. W. , Wilson M. W. , Ho P. P. K.
Published: December 2020

Cultural and nutritional requirements for maximum
l
-asparaginase synthesis were determined. Conventional aerobic and anaerobic fermentations were not satisfactory. The former yielded larger quantities of cells containing minimal amounts of
l
-asparaginase, whereas the latter supplied only minute amounts of bacteria that contained an abundance of enzyme. However, the combination of these classical methods, i.e., allowing growth to proceed aerobically until the mid to late exponential phase and then forcing the facultative microbial cells toward anaerobic metabolism by static incubation, produced 2.6 international units of enzyme per ml of fermentation broth when glucose was present. Enzyme synthesis was not induced by terminating aeration-agitation in the absence of glucose, nor was it induced in the presence of glucose when aeration was continued. Use of 0.2
m
phosphate buffer resulted in a constant
p
H near the optimum value of 7.5 during
l
-asparaginase formation. Addition of 0.05%
l
-asparagine prior to induction was also beneficial, but other amino acids or their catabolites failed to increase biosynthesis of
l
-asparaginase.
One-Day Fluorescent-Antibody Procedure for Detecting Salmonellae in Frozen and Dried Foods
Authors: Goepfert J. M. , Mann M. E. , Hicks R.
Published: December 2020

The indirect fluorescent-antibody technique was used to examine 422 food samples for the presence of salmonellae. A cultural phase involving a 16-hr preenrichment in buffered nutrient broth-milk medium followed by a 4- to 5-hr subculture into fresh medium of the same composition was evaluated. This procedure yielded a sufficient population of salmonellae so that no false-negative results were obtained. Of the 31 false-positives obtained, 12 samples yielded positive cultural results upon extensive subculture of the original enrichment broths. Yeast cells and both vegetative and spore forms of bacilli were observed to fluoresce when stained with anti-
Salmonella
serum. Efforts to ascertain the cause of these cross-reactions and several alternate explanations are discussed.
Antibacterial Activity of Gentamicin Sulfate in Tissue Culture
Authors: Rudin A. , Healey A. , Phillips C. A. , Gump D. W. , Forsyth B. R.
Published: December 2020

Gentamicin is a more effective in vitro bacterial inhibitor than combined penicillinstreptomycin, is nontoxic to tissue culture monolayers, and does not inhibit virus replication.
Survival of
Listeria monocytogenes
in Experimentally Infected Mice
Authors: Wilkinson Thomas R. , Hall Elizabeth R.
Published: December 2020

Physiological saline was found to be very detrimental to the viability of
Listeria monocytogenes.
The LD
50
value was substantially reduced when peptone was used as the suspending fluid rather than saline. Normal splenic tissue was not inhibitory to the survival of
Listeria.
In experimentally infected mice,
L. monocytogenes
survived for 8 days in the peritoneal cavity and for at least 11 days in the spleen.
Staining of Bacteriophages for Light Microscopy
Authors: McCamish Joan , Mickelson J. C.
Published: December 2020

Bacteriophages can be stained with a flagella stain, making them visible by light microscopy.
Agar Diffusion Method for the Differentiation of
Bacillus anthracis
Authors: Angelety Lorell H. , Wright George G.
Published: December 2020

A method was developed for identification of
Bacillus anthracis
based on elaboration of protective antigen by individual colonies and its detection by double-diffusion precipitation in agar plates.
Occurrence of a Carrier State for
Herpesvirus tamarinus
in Marmosets
Authors: Murphy Bert L. , Maynard James E. , Krushak Donald H. , Fields Rose M.
Published: December 2020

The ecology of herpesviruses in marmosets and other nonhuman primates is important today, for colonies of these animals are being established for biomedical research. This paper presents the first reported isolations of
Herpesvirus tamarinus
from throat swabs of a healthy white-lipped marmoset carrier (
Saguinus nigricollis
) during a 2-month period. Infectivity studies with this virus in both white-moustached (
S. mystax
) and white-lipped marmosets demonstrated that the virus is not lethal to white-moustached marmosets (perhaps a more resistant species) at 1,000 TCID
50
. Which environmental conditions trigger the unmasking of herpesviruses in marmosets is not known. Hoever, intermittent
H. tamarinus
shedding may help explain spontaneous infections in established colonies as well as suggest an additional mechanism for transmission of virus between marmosets under natural conditions.
Uptake of
3
H-Tetracycline by Resistant and Sensitive
Escherichia coli
Authors: Reynard A. M. , Nellis L. F. , Beck M. E.
Published: December 2020

The uptakes of
3
H-tetracycline by 12 tetracycline-sensitive and 24 tetracycline-resistant
Escherichia coli
hospital cultures were found to be 270 and 75 nmoles of tetracycline per milliliter of cell water per 20 min, respectively. This confirms reports by other investigators who, by using only one or two cultures, suggested a relationship between tetracycline uptake and tetracycline resistance. However, minimum inhibitory concentrations of tetracycline for the cultures bore no relation to the tetracycline uptake values, suggesting that loss of tetracycline uptake may not be the primary cause of resistance. In addition there were three resistant cultures with uptake values greater than 140 and two sensitive cultures with uptakes lower than 180, raising the question of how these tetracycline-resistant cultures could grow with tetracycline at concentrations nearly as high as those found to inhibit growth of sensitive organisms. Of the tetracycline-resistant cultures, 15 were able to transfer tetracycline resistance to a recipient organism and 9 were not. Two of the cultures transferred TC-resistance to a recipient with no modification-restriction system (
E. coli
C) but did not transfer resistance to a recipient with a known modification-restriction system (
E. coli
K-12).
Indirect Hemagglutination Test for Detection of Antibodies to Cytomegalovirus
Authors: Bernstein Michael T. , Stewart John A.
Published: December 2020

An indirect hemagglutination test has been adapted for use with cytomegalovirus. The test is highly sensitive and reproducible. Both immunoglobulin M and immunoglobulin G antibodies can be detected by this method. The hemagglutination reaction can be inhibited by small amounts of homologous antigen. This principle permits early identification of virus isolated from diagnostic specimens.
Citric Acid Metabolism in the Bovine Rumen
Authors: Wright D. E.
Published: December 2020

Rumen microorganisms rapidly metabolize citric acid to carbon dioxide and acetic acid. The rate of metabolism varied between 0.00008 and 0.76 μmoles per g per min, the rate becoming higher as the citric acid concentration increased. The addition of potassium chloride to rumen contents decreased the rate of utilization. The results indicate that dietary citric acid is unlikely to accumulate in the rumen to a sufficiently high level to be an important factor in hypomagnesemia, except where other factors such as very high potassium levels in the food influence its metabolism.
Standardization of Human Diploid Fibroblast Cultivation: Trypsinization Procedure
Authors: Litwin Jack
Published: December 2020

Human embryonic diploid lung fibroblasts were used to examine the influence of the trypsinizing procedure on the growth and adsorption of these cells. The best buffer for trypsinizing these cells was Hanks balanced salt solution containing 0.5% lactalbumin hydrolysate. Trypsinizing cells at 4 C gave better growth results than trypsinization at higher temperatures. The presence of antibiotics in the trypsin buffer increased the longevity of the cells. Cells initially trypsinized from tissue in phosphate-buffered saline without Ca
2+
or Mg
2+
and 0.33
m
sucrose plus 10
−3
m
Mg
2+
gave rise to better subsequent growth and adsorption than cells from tissue trypsinized in other buffers.
Thermal Inactivation of Poliovirus in the Presence of Selective Organic Molecules (Cholesterol, Lecithin, Collagen, and β-Carotene)
Authors: Milo George E.
Published: December 2020

Poliovirus type 1 strain LS-a exhibited the typical thermal inactivation pattern observed previously by other investigators for poliovirus strains sensitive to the temperatures used in these experiments. However, when the virus suspension was thermally treated at 121 C for 5 sec in the presence of 2% collagen, a stabilizing effect on the virus was observed. The stabilizing effect in the presence of other food additives, such as cholesterol, lecithin, or β-carotene, was less dramatic or there was no effect at all. Pretreatment of the cells with the same additives before inoculation induced various changes in the susceptibility of the cells to infection by poliovirus. Lecithin and cholesterol treatment appeared to increase HeLa cell susceptibility to the invading virus, thereby enhancing infectivity. Ultraviolet examination of thermally inactivated virus (121 C) suspensions did not indicate any severe denaturation of the nucleic acid core. Subsequent phenol extraction of the infectious nucleic acid from the heat-inactivated virions revealed that infectious nucleic acid was still present in the denatured heat-treated (62 to 72 C) samples of virion. The immediate past history of treatment of the uninoculated cells appeared to be important, since pretreatment of the cells with cholesterol before inoculation resulted in a noticeable increase in infectivity. In addition, cholesterol-treated uninoculated cell sheets also exhibited an increase in longevity compared to the uninoculated, untreated controls.
Effects of Oxyamylose and Polyacrylic Acid on Foot-and-Mouth Disease and Hog Cholera Virus Infections
Authors: Leunen Joseph , Desmyter Jan , De Somer Pierre
Published: December 2020

Two interferon-inducing polycarboxylates were tested for antiviral activity on foot-and-mouth disease (FMD) virus infections in mice, guinea pigs, and swine. Polyacrylic acid, given intraperitoneally, had a protective effect on infection by FMD virus administered in the peritoneal cavity of mice and in the foot pad of guinea pigs. Chlorite-oxidized oxyamylose (COAM) was effective in mice at a dosage of 2 mg/kg. Swine were not protected against naturally transmitted FMD by 120 mg/kg of COAM nor by polyacrylic acid. Swine were not totally unresponsive to COAM since it delayed symptoms of hog cholera. Interferon was not detected in the serum of COAM-treated swine. With FMD virus, an example was found of activity of interferon inducers in experimental hosts and lack of activity in a natural host.
New Method of Isolating Salmonellae from Milk
Authors: Wells Joy G. , Morris George K. , Brachman Philip S.
Published: December 2020

The use of a cotton gauze swab and subsequent culture of the swab was found to be a more sensitive method for isolating
Salmonella
from liquid milk than the revised procedure of North. The swab method was found to be as sensitive as the North procedure for recovering
Salmonella
when incubated at 37 C but more sensitive when incubated at 43 C. Incubation of the swab cultures at the elevated temperature of 43 C gave good results when
Salmonella
was present at levels as low as one per liter. Swabs exposed to milk contaminated with 100
Salmonella
per liter remained positive even when subsequently washed for 2 hr in noncontaminated milk. Bismuth sulfite agar and Brilliant Green sulfadiazine agar were equally effective for isolating
Salmonella
from broth cultures; use of both media resulted in maximal isolations.
Antigenic Relationships Among the Proteolytic and Nonproteolytic Strains of
Clostridium botulinum
Authors: Solomon H. M. , Lynt R. K. , Kautter D. A. , Lilly T.
Published: December 2020

Relationships of the somatic antigens among
Clostridium botulinum
strains have been investigated by tube agglutination and agglutinin absorption tests. Results revealed a relationship by which strains of
C. botulinum
are grouped by their proteolytic capacity rather than by the type of specific toxin produced. Thus,
C. botulinum
type E and its nontoxigenic variants, which are nonproteolytic, share common somatic antigens with the nonproteolytic strains of types B and F. Absorption of antiserum of a strain of any one type with antigen of any of the others removes the antibody to all three types. In the same manner,
C. botulinum
type A shares somatic antigens with the proteolytic strains of types B and F, and absorption of any one antiserum with an antigen of either of the other two types removes the antibody to all three types. Partial cross-agglutination of
C. sporogenes, C. tetani
, and
C. histolyticum
with the somatic antisera of the proteolytic group was also observed.
Statistical Evaluation of Diluents and Automatic Diluting and Pipetting Machines in Influenza Serology
Authors: O'Brien Thomas C. , Rastogi Suresh , Tauraso Nicola M.
Published: December 2020

The use of three diluents (i.e., 0.01
m
phosphate-buffered saline, PBS; PBS with 0.2% gelatin, PBS/GEL; and PBS with 0.4% bovine plasma albumin) and three methods (i.e., the standard tube macro-procedure, TUBE; the manual microtechnique, MANUAL; and the semiautomatic microtechnique, AUTO) were statistically compared for their reproducibility and sensitivity in determining hemagglutinin (HA) and hemagglutination-inhibition (HI) antibody titers. In the HA test, analyses of between-cell variances of the different methods showed the AUTO microtiter procedure to be more reproducible than the standard TUBE method. The MANUAL microtiter procedure was the least reproducible. In the HI test, the TUBE method was the most reproducible. No significant difference in the reproducibility of the diluents was observed in either the HA or HI test. When a comparison of the sensitivity of test methods and diluents was made for determining HA titers, the AUTO microtiter procedure and PBS/GEL diluent appeared to be the method and diluent of choice. Evaluation of another instrument, the autopipetter, which standardizes the volume of diluent to be added in the microtechnique, suggests that the reproducibility of the AUTO microtiter procedure might be further increased.
Incidence of Heat-Resistant Molds in Eastern Orchards and Vineyards
Authors: Splittstoesser D. F. , Kuss F. R. , Harrison Wanda , Prest Dorothy B.
Published: December 2020

Over 70% of the samples of fruit, vegetation, and soil obtained in surveys of New York orchards and vineyards were contaminated with heat-resistant molds. The counts generally were low, under one per gram.
Byssochlamys fulva
was the most common isolate. Other isolates were identified as
B. nivea, Paecilomyces varioti, Aspergillus fischeri, A. fischeri
var.
spinosus, A. fumigatus, Penicillium vermiculatum
, and
P. ochro-chloron.
Survey of Infectious Multiple Drug Resistance Among
Salmonella
Isolated from Animals in the United States
Authors: Pocurull Dorothy W. , Gaines Stuart A. , Mercer H. Dwight
Published: December 2020

Salmonella
cultures were obtained from outbreaks of animal disease from 37 states and 1 territory. They were screened for resistance to 11 antimicrobial drugs. Of the 1,251 strains studied, 935 were resistant to one or more of these agents. The three most common resistance patterns were ampicillin, dihydrostreptomycin, sulfamethoxypyridazine, tetracycline; ampicillin, dihydrostreptomycin, sulfamethoxypyridazine; dihydrostreptomycin, sulfamethoxypyridazine, tetracycline. Resistance transfer was demonstrated on 267 multiply resistant cultures, of which 181 were able to transfer all or part of their resistance pattern to a drug-sensitive recipient.
Tolerance of Bacteria to High Concentrations of NaCl and Glycerol in the Growth Medium
Authors: Marshall Betty J. , Ohye D. F. , Christian J. H. B.
Published: December 2020

When compared at similar levels of water activity, glycerol was more inhibitory than sodium chloride to relatively salt-tolerant bacteria and less inhibitory than salt to salt-sensitive species.
Biochemical and Serological Characteristics of a
Yersinia enterocolitica
Isolate
Authors: Sedgwick Ann K. , Tilton Richard C.
Published: December 2020

Yersinia enterocolitica
was isolated from human mesenteric lymph nodes. Its morphological characteristics and biochemical and serological reactions are described.
Virus in Water
Authors: Liu O. C. , Brashear D. A. , Seraichekas H. R. , Barnick J. A. , Metcalf T. G.
Published: December 2020

A preliminary study was carried out on evaluating a flow-through gauze sampler for its efficiency in recovering virus from both fresh and seawater. An attenuated type 1 poliovirus was used as the working model. When tap water was sampled, the amounts of virus adsorbed by the gauze pads were very small, about 2% of the total number of virus particles flowing through the device. The virus adsorption and recovery increased to 15 to 19% when seawater was sampled. Addition of NaCl to tap water produced a much better effect on virus adsorption and recovery by this device, i.e., 47% of the total virus particles in each sample. The best viral elution from the pads was obtained by using buffer solution of
p
H 8.0 to 9.0 containing a small amount of animal serum. Repeated elutions from the pads were necessary to recover the most virus although the first eluate contained approximately 50% of the adsorbed virus. Further development of this device appears warranted, because of (i) the simplicity of the procedure, (ii) its capability of sampling large volume of water, (iii) the low cost of collecting samples, and (iv) the feasibility of obtaining a rough quantitative assessment of viral pollutants in water examined.
Comparison of Animal Sera for Suitability in Coagulase Testing
Authors: Orth D. S. , Chugg L. R. , Anderson A. W.
Published: December 2020

The sera of several animals were examined for suitability in coagulase testing. The assay for coagulase-reacting factor (CRF) activities of the whole sera indicated the following relative concentrations of CRF: human > pig > rabbit > horse > bovine, chicken, and lamb. Human, pig, and rabbit sera had adequate amounts of CRF for coagulase testing. The plasmin activities of the different sera, arranged from the strongest to the weakest, were as follows: rabbit > human > lamb > horse > bovine, chicken, and pig. Fibrinolysis was observed when rabbit, human, lamb, or horse sera were incorporated into coagulase test agars. Pig serum was superior to the other sera for use in the plate test for coagulase since it had adequate amounts of CRF and the plasminogen-plasmin system was not activated by staphylokinase or staphylococcal Müller factor. Heparinized pig plasma was more suitable than citrated pig plasma since citrate interfered with the growth of
Staphylococcus aureus
, and the use of heparinized plasma prevented false-positive coagulase reactions due to citrate utilization.
Analysis of
Clostridium botulinum
Toxigenic Types A, B, and E for Fatty and Carbohydrate Content
Authors: Fugate Kearby J. , Hansen Lydell B. , White Olivia
Published: December 2020

Lyophilized, 48-hr log-phase vegetative cells were extracted with chloroform-methanol (2:1, v/v) and ethanol-ether (3:1, v/v) and then saponified with methanolic KOH. Gas-liquid chromatography of the methyl esters of extractable fatty acids revealed distinctive “pattern profiles” of
Clostridium botulinum
toxigenic types “A,” “B,” and “E.”
C. perfringens
type “A” and
Escherichia coli
strain “B” were also studied in a similar manner and were found to give pattern profiles which were distinct even from those obtained for the
C. botulinum
microorganisms. Amino sugar content of the five microorganisms was determined by using a Beckman amino acid analyzer. The molar ratio of glucosamine to that of galactosamine was found to be of further assistance in distinguishing the individual microorganisms.
Acute Toxicity of Ochratoxins A and B in Chicks
Authors: Peckham John C. , Doupnik Ben , Jones Oscar H.
Published: December 2020

Ochratoxins A and B were given to 1-day-old Babcock B-300 cockerels to evaluate acute toxic effects. Two trials with ochratoxin A gave 7-day oral median lethal dose estimates of 116 μg (3.3 mg/kg) and 135 μg (3.9 mg/kg) per chick. Chicks given daily oral doses of 100 μg of ochratoxin A died on the second day. Single subcutaneous doses of 400 μg of ochratoxin A were also lethal. The 7-day oral median lethal dose of B was estimated at 1,890 μg (54 mg/kg) per chick. Chicks given oral doses of 100 μg of ochratoxin B daily for 10 days survived. Sublethal doses of both ochratoxins A and B resulted in growth suppression which was proportional to the amount of ochratoxin given. Visceral gout was the principal gross finding. Microscopic examinations revealed acute nephrosis, hepatic degeneration or focal necrosis, and enteritis. Suppression of hematopoiesis in the bone marrow and depletion of lymphoid elements from the spleen and bursa of Fabricius were frequently seen. Both ochratoxins appeared to have similar pathological effects. This is the first report on the toxicity of ochratoxin B.
Antimicrobial Properties of Natural Phenols and Related Compounds
Authors: Jurd L. , King A. D. , Mihara K. , Stanley W. L.
Published: December 2020

Obtusastyrene (4-cinnamylphenol) displays effective antimicrobial activity in vitro against a variety of gram-positive bacteria, yeasts, and molds. The activity of obtusastyrene is not appreciably affected by
p
H, and its minimal inhibitory concentrations, 12 to 25 μg/ml for bacteria and 12 to 100 μg/ml for fungi, compare favorably with those of a number of synthetic, phenolic antimicrobial agents.
Prevalence of
Clostridium botulinum
in Semipreserved Meat Products
Authors: Abrahamsson Kerstin , Riemann H.
Published: December 2020

Samples of semipreserved meat products were taken, and 372 were examined for
Clostridium botulinum.
Five samples contained type A and one sample type B.
Rapid Test for Urease and Phenylalanine Deaminase Production
Authors: Ederer Grace Mary , Chu Jackie H. , Blazevic Donna J.
Published: December 2020

A rapid urea-phenylalanine medium was effective for the identification of
Proteus
and, with one exception,
Providencia
. Most
Klebsiella
and a few
Enterobacter were
urease-positive with this method.
Oxidation of Alcohols by
Botrytis cinerea
Authors: Fukuda D. S. , Brannon D. R.
Published: December 2020

Crude cell-free preparations of
Botrytis cinerea
were found to oxidize straight-chain primary alcohols (except methanol), aromatic primary alcohols, and unsaturated primary alcohols. The resulting products were the corresponding aldehydes and an equal molar quantity of hydrogen peroxide.
Standardization of Human Diploid Fibroblast Cultivation: Centrifugation Procedure
Authors: Litwin Jack
Published: December 2020

The effect of varying centrifugal forces on the growth rate, longevity, and adsorption on glass of human embryonic diploid lung fibroblasts was studied. Cells centrifuged at 120, 500, or 1,500 ×
g
at each passage had similar growth rates but their longevity decreased slightly with increasing force. These forces had no influence on the proportion of cells attaching to the glass. When the material in the first supernatant was recentrifuged at 2,000 ×
g
for 30 min and added to the cells precipitated in the first centrifugation, the longevity of these cells was increased by several cell divisions. Cells which were not centrifuged but added directly from the cell suspension in trypsin to the new culture grew at a slightly slower rate than the centrifuged cells and became senescent at an earlier time. However, the noncentrifuged cells adsorbed to glass better than those centrifuged.
Identification of
Mycoplasmatales:
Procedures for Both Characterization and Purification
Authors: Barber Thomas L. , Fabricant Julius
Published: December 2020

Procedures with potential value for identification and purification of
Mycoplasma
were applied to over 240 cultures representing 11 of the 12 known avian serotypes. Growth was tested at
p
H 5.5 and 9.5, at 25 and 42 C, in serum-free media, and in the presence of (i) 1% bile salts, (ii) 3% NaCl, and (iii) 0.02% methylene blue. One avian
Mycoplasma
serotype grew in broth containing 1% bile salts. Two of 11 avian serotypes were resistant to 0.02% methylene blue. A number of
Mycoplasma
strains grew at 42 C or in a
p
H 9.5 medium. Usefulness of these procedures for purifying cultures of
Mycoplasma
is discussed.
Identification of
Mycoplasmatales:
Characterization Procedures
Authors: Barber Thomas L. , Fabricant Julius
Published: December 2020

A large collection of avian
Mycoplasma
cultures was used in studies to improve and develop biological and biochemical characterization techniques. Differential patterns among 11 avian serotypes were shown by carbohydrate fermentation, tetrazolium- and methylene blue-reduction reactions, breakdown of arginine, and the formation of film on egg yolk-agar. Some cultures fermented as many as 14 carbohydrates. Polyhydric alcohols and pentoses were among the compounds fermented. An improved procedure for determining methylene blue reduction by
Mycoplasma
was developed. These simple, rapid procedures are reproducible and should be useful in grouping
Mycoplasma
isolates prior to definitive identification by serological or other means.
Effect of the Purification of Virus Antigens on the Production of Specific Complement-Fixing Antibodies
Authors: Engler Reto , Keairnes Patricia
Published: December 2020

The effect of viral purification procedures on the antibody response of guinea pigs to immunization with reovirus type 2 and echovirus type 19 was investigated. Three grades of antigens were employed: (i) infectious monkey kidney tissue culture fluid (TCF), (ii) virus sedimented in the ultracentrifuge and suspended in phosphate-buffered saline, and (iii) virus purified by centrifugation in CsCl density gradients. The antibody response of the guinea pigs was studied by the hemagglutination inhibition, complement fixation, and serum neutralization tests. Only sera produced from virus purified by CsCl density gradients reacted specifically with homologous antigen in the complement fixation test. Sera from animals receiving tissue culture fluid virus or sedimented virus cross-reacted with heterologous antigens such as tissue culture fluid from uninfected monkey kidney cells. All sera, however, reacted specifically in hemagglutination inhibition and serum neutralization tests. Sera from intranasally infected animals (reovirus type 2), even though reacting specifically in the complement fixation test, had much lower titers than sera from animals inoculated intramuscularly.
Factors Which Influence Synergism by Neomycin and Oxytetracycline
Authors: Williams B. J.
Published: December 2020

Six strains of enteropathogenic gram-negative bacteria were tested for susceptibility to neomycin or oxytetracycline alone and combined in fixed ratios. The minimal inhibitory concentration for the combination was less than one-half of that expected if the antibiotic activities were simply additive. Neomycin alone was more effective against bacteria multiplying in the presence of abundant oxygen, whereas oxytetracycline alone was more effective against bacteria multiplying in relatively anaerobic environments; when combined, the antibiotics complemented each other by their opposing optima for activity. Oxygen concentration,
p
H, and neomycin activity are related, and the depression of acid production by oxytetracycline is believed to be partially responsible for the synergistic activity of this pair of antibiotics.
Semi-Micro, Dye-Binding Assay for Rabbit Interferon
Authors: Armstrong John A.
Published: December 2020

The semi-micro method for interferon assay was based on quantitation of inhibition of cytopathic effects in 6-mm wells. Cultures were exposed to interferon dilutions, challenged with vesicular stomatitis virus, and stained with methylrosanaline chloride. The bound dye was then eluted and measured colorimetrically. The method was more sensitive than the plaque-inhibition method and was extremely economical. Culture age was the most important factor affecting reproductibility.