bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparative Assessment of Fouling Scenarios in an Axial Flow Compressor
Authors: Templalexis Ioannis , Pachidis Vasilios , Aguirre Hasani Azamar
Published: December 2020

It is commonly accepted that fouling degrades severely axial compressor performance. Deposits build up as operating hours sum up, causing a decrease in the compressor's delivery pressure, efficiency, and flow capacity. Compressor susceptibility to fouling depends on many factors, such as atmospheric conditions, air quality, filtration system, and the size and design of the compressor. The current study identifies four basic operating scenarios which refer to the same compressor, in order to put forward a comparative assessment as to how incoming air quality would affect compressor performance. SOCRATES, an in-house, streamline curvature-based through-flow tool, in conjunction with a detailed, fully customizable fouling empirical model, conceived based on flow physics and relevant experimental data, is used to qualify and quantify compressor degradation with time.
Intraoperative ultrasound in liver and pancreatic surgery
Authors: Bartoș Adrian , Iancu Ioana , Ciobanu Lidia , Badea Radu , Spârchez Zeno , Bartoș Dana Monica
Published: December 2020

This paper summarizes the current knowledge of intraoperative ultrasonography (IOUS) in open and laparoscopic ab-dominal surgery. The abdominal IOUS contributes to the diagnosis and staging (for parenchymal organ tumors), to establish surgical procedure and to guide surgical maneuvers. The main applications are represented by liver, biliary tract and pancreatic pathology. Diagnostic approaches are frequently combined with therapeutic purposes. The technique, equipment, training, benefits and limits of IOUS in abdominal surgery are discussed and cases from our experience are used as examples.
In situ manipulation of van der Waals heterostructures for twistronics
Authors: Yang Yaping , Li Jidong , Yin Jun , Xu Shuigang , Mullan Ciaran , Taniguchi Takashi , Watanabe Kenji , Geim Andre K. , Novoselov Konstantin S. , Mishchenko Artem
Published: December 2020

Rotation of 2D materials by polymer patch and gel stamp manipulator opens up a new strategy for twistronics.
Wireless, skin-interfaced sensors for compression therapy
Authors: Park Yoonseok , Kwon Kyeongha , Kwak Sung Soo , Yang Da Som , Kwak Jean Won , Luan Haiwen , Chung Ted S. , Chun Keum San , Kim Jong Uk , Jang Hokyung , Ryu Hanjun , Jeong Hyoyoung , Won Sang Min , Kang Youn J. , Zhang Michael , Pontes David , Kampmeier Brianna R. , Seo Seon Hee , Zhao Jeffrey , Jung Inhwa , Huang Yonggang , Xu Shuai , Rogers John A.
Published: December 2020

Soft, wireless sensors monitor the temperature and interface pressure of the patient’s skin for compression therapy.
BATF regulates innate lymphoid cell hematopoiesis and homeostasis
Authors: Liu Qingyang , Kim Myung H. , Friesen Leon , Kim Chang H.
Published: December 2020

Batf supports differentiation of ILC progenitors and optimal population of NK, ILC1, ILC2, and ILC3 in peripheral tissues.
Gamma-Ray Sterilization and Residual Toxicity Studies of Ground Beef Inoculated with Spores of
Clostridium botulinum
Authors: Kempe Lloyd L. , Graikoski John T.
Published: December 2020

Inoculated packs of cooked and raw ground beef were sterilized with gamma radiation from cobalt-60. With inocula of 5,000,000
Clostridium botulinum
213B spores per g of cooked ground beef, 3.8 megarad were required for sterilization; in raw ground beef, 3.72 megarad sterilized the meat when inocula of 1,700,000
C. botulinum
213B spores were used per g. Using
C. botulinum
62A spores, cooked ground beef inoculated with 5,200,000 spores per g was sterilized with 3.85 megarad; raw ground beef, inoculated with 2,670,000 spores per g, was sterilized with 3.6 megarad. Cans of meat that were considered sterile by lack of culture growth after incubation for at least 6 months and, in some instances, as long as 5 years, were tested for the presence of botulinus toxin. No toxin was found in any meat taken from inoculated packs prepared from
C. botulinum
213B spores; however, all cans of meat that had been inoculated with more than 2,670,000
C. botulinum
62A spores per g of meat, contained type A toxin. It was shown that these latter inocula of heat-shocked spores, by themselves, contained sufficient toxin to kill mice. However, more toxin appeared to be present than could be ascribed to the unirradiated spores alone. This finding is discussed.
Evaluation of Natural Products for Algicidal Properties
Authors: Safferman Robert S. , Morris Mary-Ellen
Published: December 2020

A procedure for the screening of antialgal substances has been described and evaluated with specific reference to microbial products. Data on the extracellular materials of 545 actinomycete and fungal isolates showed a wide distribution of agents having algicidal activities. Of these culture filtrates, 20.4% apparently had selective antagonistic effects against particular algal groups. A more comprehensive examination revealed that metabolic products from two actinomycete cultures exhibited properties that warrant further studies on their chemical and physiological characteristics.
Successive Microbial Populations in
Calimyrna
Figs
Authors: Miller M. W. , Phaff H. J.
Published: December 2020

Smyrna-type (
Calimyrna
) figs have essentially sterile internal tissue until visited by the pollinating fig wasp,
Blastophaga psenes
, which introduces a specific microflora consisting of
Candida guilliermondii
var.
carpophila
and
Serratia plymuthica
. This flora persists and develops in numbers throughout the ripening period until maturity of the fruit. These organisms do not cause spoilage. The presence of
C. guilliermondii
var.
carpophila
appears to increase the attractiveness of the fruit to drosophilae.
Drosophila
(mainly
D. melanogaster
) carry spoilage yeasts and bacteria on their exterior body parts, and introduce these organisms during ovipositing in the fruit cavity. The spoilage yeasts consist almost entirely of apiculate yeasts (
Hanseniaspora valbyensis, H. uvarum
, and
Kloeckera apiculata
) and of
Torulopsis stellata
, which cause active fermentative spoilage. Spoilage bacteria (primarily
Acetobacter melanogenus
) are also introduced with the yeasts. Organic acids are produced by these yeasts as well as by the
Acetobacter
. A number of minor spoilage yeasts were also identified.
Diploid Hybridization in a Heterothallic Haploid Yeast,
Saccharomyces rouxii
Authors: Mori Haruhiko , Onishi Hiroshi
Published: December 2020

By crossing of a heterothallic haploid yeast,
Saccharomyces rouxii
, we have succeeded in obtaining diploid hybrids. This paper shows one possible method of breeding heterothallic haploid yeasts for industrial application.
S. rouxii
is highly salt-tolerant and plays an important role in shoyu and miso fermentation. Therefore, genetic improvements of the properties are of commercial importance. Since newly isolated
S. rouxii
could neither conjugate nor sporulate on sporulation media commonly used, a suitable medium for conjugation and sporulation of
S. rouxii
was firstly investigated. A 5% NaCl Shoyu-koji extract agar was found to be most efficient. Next, we tried to get diploid strains by mass culture of two mating types on the conjugation medium, but several phenomena made this difficult: (i) zygotes quickly sporulated before budding; (ii) several zygotes showed terminal budding, but the buds could not grow into diploid cells, suggesting they would be heterocaryon; and (iii) a few zygotes lost their viability. After trying to isolate and cultivate a large number of zygotes in various combinations of crossing by micromanipulation, we fortunately recognized that large cells arose from some combinations. The analysis of ploidy suggested that the large cells would be diploid. Also, they showed sporulation of typical
Saccharomyces
, i.e., two to four spores in an unconjugated ascus. The diploid strains thus obtained were highly salt-tolerant and stable in liquid medium. Therefore, the procedure presented here would be effective for breeding salt-tolerant
S. rouxii
.
Growth Response of
Lactobacillus brevis
to Aeration and Organic Catalysts
Authors: Stamer J. R. , Stoyla B. O.
Published: December 2020

Under stationary and anaerobic conditions, greater cell yields of
Lactobacillus brevis
were obtained from autoclaved than from filter-sterilized glucose media. Fructose, tentatively identified as a product generated by the heating process, served as an excellent catalyst for inducing growth. The addition of micromolar quantities of pentoses or potential pentose precursors to the filter-sterilized medium was equally effective in stimulating growth. These organic catalysts were not essential for growth under aerobic conditions. Upon agitation, similar cell yields were obtained from the autoclaved and filter-sterilized media. The micromolar quantities of lactic acid produced per micromole of carbohydrate fermented appeared to be similar under aerobic and static conditions of incubation. The final concentration of acetic acid increased as the result of agitation. This increase in volatile acidity was accompanied by a significant decrease in ethyl alcohol production. The cell yield was increased nearly 50% under aerobic conditions.
Agar-Gel Precipitin-Inhibition Test for Coccidioidomycosis
Authors: Ray John G.
Published: December 2020

The agar-gel precipitin-inhibition serological test for coccidioidomycosis was a more sensitive indicator of
Coccidioides immitis
antibodies than the tube precipitin, the agar-gel immunodiffusion, in the complement-fixation tests in assaying monkey sera, whether these sera were from prechallenge-vaccinated or postchallenged animals. When applying this technique to the assay of human sera, an analogous finding generally persisted. However, some human sera were positive by the complement-fixation test and negative by the agar-gel precipitin-inhibition test. These sera were diffused in agar-gel against various coccidioidin complement-fixation, tube precipitin, and agar-gel precipitin-inhibition test antigens with essentially negative results.
Selective Inhibition of
Escherichia coli
in the Presence of
Salmonella typhimurium
by Phenethyl β-D-Galactopyranoside
Authors: Johnston M. A. , Thatcher F. S.
Published: December 2020

Phenethyl β-
d
-galactopyranoside (PEG) was hydrolyzed by the β-galactosidase of
Escherichia coli
to form the toxic product phenethyl alcohol.
Salmonella typhimurium
did not hydrolyze PEG. In mixed culture, the ratio of
S. typhimurium
to
E. coli
was increased by growing the organisms in lactose broth containing 2.5% PEG. The high concentration of PEG required for inhibition of
E. coli
can be attributed to inadequate cell permeability rather than to prevention of β-galactosidase induction.
In Vitro Effects of Some Chemotherapeutic Agents on Mycobacteria
Authors: Olitzki A. L. , Godinger D. , Israeli M. , Honigman A.
Published: December 2020

Examination of the bactericidal and bacteriostatic effects of nine antibiotics on atypical mycobacteria revealed that streptovaricin complex and streptovaricin C exerted bactericidal effects on several strains in concentrations lower than 1.0 μg/ml. An exposure to the drug for 48 hr at 37 C was necessary to effect a complete inactivation of more than 99.9% of the exposed microorganisms. The appearance of strepto-varicin-resistant mutants was observed. However, these mutants were unstable, and reversion to streptovaricin susceptibility occurred. Celesticetin salicylate, added in a concentration of 100.0 μg/ml to the medium of Olitzki and Gershon inoculated with
Mycobacterium leprae
, effected a complete change of the uniformly stained mycobacteria to bipolarity, which indicates the devitalization of this microorganism.
Effect of Brilliant Green on the Motility of Salmonellae and Other Selected Microorganisms
Authors: Sessoms A. R. , Banwart G. J.
Published: December 2020

The effect of Brilliant Green on motility was studied with
Salmonella anatum, S. derby, S. tennessee, Escherichia coli, Proteus vulgaris
, and
Pseudomonas aeruginosa
. Semisolid tryptic soy-agars containing 0, 20, or 40 mg of Brilliant Green per liter were used as the motility media. Both concentrations of Brilliant Green inhibited the growth of the non-
Salmonella
species through the semisolid agar. For 24 hr, the Brilliant Green appeared to limit the growth of the salmonellae; however, by 48 hr the salmonellae were able to grow through the semisolid agars. The presence of Brilliant Green in the motility media aided in the detection of
Salmonella
when mixed cultures were used.
Effect of Repeated Irradiation on Various Characteristics of
Salmonella
Authors: Licciardello J. J. , Nickerson J. T. R. , Goldblith S. A. , Bishop W. W. , Shannon C. A.
Published: December 2020

Four
Salmonella
serotypes which had been subjected to either 15 or 20 cycles of irradiation and subculture were examined for possible changes induced by the treatment. With three serotypes virulence remained unchanged, and with one serotype a reduction had occurred. A few minor changes in the biochemical characteristics occurred in some instances, but with all cultures the serological property was affected to some extent. Lag times and growth rates of the treated cultures were not altered, but the maximal viable population was usually less than that for untreated cultures.
Correlations Between Virulence and Other Characters of
Clostridium perfringens
Type A
Authors: Forget A. , Paquette G. , Roy A. , Fredette V.
Published: December 2020

The correlation analysis which has already proved its value in ecology has not yet been applied to the determination of virulence indicators. Its application to a group of
Clostridium perfringens
type A strains has brought out some characters that may be considered as virulence indicators. This study suggests that the toxicity of the culture supernatant fluids for mice is significantly correlated with the virulence for mice and guinea pigs. A significant correlation was found between the virulence of the fluid cultures for mice or guinea pigs and the coagulation of milk, production of gas (in deep agar), hydrogen sulfide production, and fermentation of glucose, sucrose, maltose, and levulose.
Differential Agar Medium for Separating
Streptococcus lactis
and
Streptococcus cremoris
Authors: Reddy M. Srinivasulu , Vedamuthu E. R. , Washam C. J. , Reinbold G. W.
Published: December 2020

The characteristic ability of
Streptococcus lactis
and inability of
Streptococcus cremoris
to hydrolyze arginine formed the basis for the development of a differential agar medium to separate these species in pure and mixed cultures. Ammonia liberated from arginine was detected by the
p
H changes occurring in the medium. The agar contained milk as the sole source of carbohydrate, arginine as the specific substrate, diffusible (K
2
HPO
4
) and nondiffusible (CaCO
3
) buffer systems, and a suitable
p
H indicator in addition to other ingredients. The nondiffusible buffer system afforded the localization of
p
H changes, and, hence, the indicator color changes immediately around individual colonies appearing on the medium.
S. cremoris
produced yellow colonies surrounded by yellow zones on this purple medium because of their ability to produce acid from lactose in the milk.
S. lactis
, on the other hand, first produced colonies similar to
S. cremoris
, but subsequent color reversal of
p
H indicator with the liberation of NH
3
resulted in the discharge of the yellow color. Hence,
S. lactis
colonies were white and devoid of zones. The difference in their colony color allowed the identification of the species in a mixture of
S. cremoris
and
S. lactis
strains. The medium was found suitable for both qualitative and quantitative differentiation.
Stability of St. Louis Encephalitis Virus in the Airborne State
Authors: Rabey Frank , Janssen Robert J. , Kelley Lee M.
Published: December 2020

The aerosol stability of St. Louis encephalitis (SLE) virus was studied over a 6-hr period at a temperature of 21 C and relative humidity values of 23, 46, 60, and 80%. Aerosols were generated from and collected in 0.75% bovine albumin-buffered saline, and spores of
Bacillus subtilis
var.
niger
were used as the tracer to determine the physical decay of the aerosols. Aerosol samples were titrated in BHK-21 cell monolayers for surviving SLE virus. The results of this study indicated that, under the test conditions employed, relative humidity had no influence on the stability of SLE virus in the airborne state.
Two-Phase Slug Flow Heat Exchanger for Microbial Thermal Inactivation Research
Authors: Stroup W. H. , Dickerson R. W. , Read R. B.
Published: December 2020

A continuous two-phase (air-liquid), slug flow, tubular heat exchanger was developed for microbial thermal inactivation research to give exposure times and temperatures in the range of high-temperature, short-time milk pasteurization as well as heat-treated sample volumes of at least 2 ml. The use of air to compartmentalize the liquid in the capillary tubing prevented the development of laminar flow, which enabled precise identification of the residence time of the fastest flowing particles in the heating, holding, and cooling sections of the instrument. Residence time distributions were quantitated by measuring the degree of spreading of radioactive tracers for water, whole milk, chocolate milk, cream, and ice-cream mix with holding temperatures from 50 to 72 C, holding times from 2 to 60 sec, and heating and cooling times of 1.7 sec each. For a holding time of 60 sec and a fastest particle velocity of 10.2 cm/sec, the velocity ratios of the fastest moving particle to the median particle were 1.05, 1.05, 1.10, and 1.13 for whole milk, chocolate milk, cream, and ice-cream mix, respectively. With shorter holding times, these velocity ratios were even closer to unity. These velocity ratios indicated that the instrument would be an effective tool for thermal inactivation research on microorganisms suspended in homogeneous fluids with a viscosity of 15 centipoises or less at the exposure temperature.
Use of Fast Green in Agar-Diffusion Microbiological Assays
Authors: Hunt D. E. , Caldwell R. C.
Published: December 2020

Microbiological assay plates containing agar stained with fast green and inoculated with test microorganisms could be readily distinguished from unstained seeded agar plates. The boundaries of zones of growth inhibition were more sharply defined in those plates which contained stained agar.
Metabolism of
14
C-Chlorobenzilate and
14
C-Chloropropylate by
Rhodotorula gracilis
Authors: Miyazaki Satoru , Boush G. Mallory , Matsumura Fumio
Published: December 2020

Rhodotorula gracilis
metabolizes Chlorobenzilate (ethyl 4,4′-dichlorobenzilate) and Chloropropylate (isopropyl 4,4′-dichlorobenzilate) to several metabolites in a basal medium supplemented by sucrose and by several intermediates of the citric acid cycle. Three identified metabolites resulting from the degradation of either acaricide, were 4,4′-dichlorobenzilic acid, 4,4′-dichlorobenzophenone, and carbon dioxide. Chlorobenzilate, i.e., ethyl ester of 4,4′-dichlorobenzilic acid, was more easily hydrolyzed than Chloropropylate, i.e., isopropyl ester of this acid, so that larger amounts of carbon dioxide and 4,4′-dichlorobenzophenone were obtained from Chlorobenzilate degradation. Regardless of acaricides used, longer incubation caused a higher accumulation of 4,4′-dichlorobenzophenone. The probable steps of the degradation pathway are: Chlorobenzilate (or Chloropropylate) → 4,4′-dichlorobenzilic acid → 4,4′-dichlorobenzophenone plus carbon dioxide. It appears that the decarboxylation of 4,4′-dichlorobenzilic acid to 4,4′-dichlorobenzophenone was hindered by α-ketoglutarate and enhanced by succinate.
Radiometric Method for Detection of Bacteremia
Authors: Washington John A. , Yu Pauline K. W.
Published: December 2020

A study was performed with simulated blood cultures to evaluate the production of
14
CO
2
as an index of bacterial growth. With a range of inoculum sizes from 4 to 4,250 colony-forming units, it was not possible to detect
14
CO
2
within 6 hr after inoculation in 59 separate experiments. In a limited trial with patients' blood cultures, the radiometric method failed to provide any earlier evidence of bacteremia than did routine broth cultures.
Cultural Estimation of Yeasts on Seaweeds
Authors: Seshadri Raja , Sieburth John M.
Published: December 2020

Five per cent suspensions of freshly harvested seaweeds were used as an inoculum to develop a selective medium for epiphytic yeasts. Conditions for satisfactory yeast growth and visualization as red colonies on membrane filters were obtained by supplementing a basal glucose-Trypticase-yeast extract-agar at
p
H 7.0 with 100 mg each of chloramphenicol and 2,3,5-triphenyl tetrazolium chloride per liter. Maximal counts were obtained by triturating the algae in prechilled (4 C) seawater with a blender for 2 to 5 min. Inhibitory phenolic materials released from phaeophytes during this process were removed with a modified Cholodny filtration. A preliminary survey indicated that yeasts were epiphytic on all nine species of seaweeds and that maximal populations occurred on the chlorophytes and rhodophytes especially during the periods of warmer water.
Diacetyl and Acetoin Production by
Lactobacillus casei
Authors: Branen A. L. , Keenan T. W.
Published: December 2020

Agitation of broth cultures of
Lactobacillus casei
retarded cellular dry weight accumulation but enhanced production of both diacetyl and acetoin. Addition of pyruvate overcame this retardation, but addition of sulfhydryl-protecting reagents did not. Both pyruvate and citrate enhanced accumulated dry weight of
L. casei
incubated without agitation, but only pyruvate increased diacetyl accumulation. Both actively dividing cells and cells suspended in buffer converted pyruvate to diacetyl and acetoin. Maximum production of diacetyl and acetoin occurred during the late logarithmic or early stationary phases. Cells isolated from pyruvate- or citrate-containing cultures showed the greatest ability to convert pyruvate to diacetyl and acetoin. The optimum
p
H for diacetyl and acetoin formation by whole cells was in the range of 4.5 to 5.5. The presence of citrate or acetate enhanced diacetyl and acetoin formation by
L. casei
cells in buffer suspension.
Electrophoretic Analysis of Ribosomal and Viral Ribonucleic Acids with a Simple Technique for Slicing Low-Concentration Polyacrylamide Gels
Authors: Schaffer F. L. , Soergel M. E. , Straube D. C.
Published: December 2020

The electrophoretic mobilities of ribosomal ribonucleic acids (RNA) from cultured mammalian (HeLa, Vero, MDBK), avian (chick embryo), and bacterial (
Escherichia coli
) cells, and RNA species extracted from selected viruses (Sindbis, polio, tobacco mosaic, Sendai) were compared, employing a simple, inexpensive technique for slicing low-concentration polyacrylamide gels. The procedure provides for rapid fractionation of gels used for characterization of RNA, incorporating extrusion and serial sectioning of frozen gels. Among 28
S
ribosomal RNA species, Vero and MDBK were indistinguishable, whereas HeLA RNA had a slightly lower mobility (higher apparent molecular weight) and chick RNA had a higher mobility (lower apparent molecular weight). The 18
S
ribosomal RNA species of the three mammalian sources were indistinguishable, but chick 18
S
RNA had a slightly lower apparent molecular weight. The inverse relation between mobility and log-molecular weight among the ribosomal and viral RNA species, though not highly precise, demonstrates the applicability of the technique to the study of molecular weights of viral RNA species.
Use of Montmorillonite for the Demonstration of Capsules of
Klebsiella aerogenes
and
Corynebacterium
sp
Authors: Bitton Gabriel , Henis Y.
Published: December 2020

A technique is described for the demonstration of bacterial capsules by using montmorillonite in combination with a conventional staining method.
Presence of Thermophilic Actinomycetes in Residential Heating Systems
Authors: Fink Jordan N. , Resnick Abe J. , Salvaggio John
Published: December 2020

Thermophilic actinomycetes, associated with a hypersensitivity pneumonitis, may be found in compost but also have been detected in heating systems of office buildings. This study was designed to determine whether these organisms were present in residential heating systems. Furnace dust or humidifier water of 12 of 20 homes contained thermophilic actinomycetes, indicating that the organisms may be found in areas other than specific decomposing organic dusts.
Chemotherapeutic Evaluation of Clotrimazole [Bay b 5097, 1 (
o
-Chloro-α-α-Diphenylbenzyl) Imidazole]
Authors: Waitz J. Allan , Moss Eugene L. , Weinstein Marvin J.
Published: December 2020

Clotrimazole has a broad spectrum of activity against yeast and filamentous fungi in vitro and also in vivo when given orally or parenterally to experimentally infected mice and when administered orally or topically to infected guinea pigs. In vitro a distinct inoculum effect has been observed with a number of strains of
Candida
and
Torulopsis
; minimal inhibitory concentrations have tended to increase with increased incubation time. With prolonged incubation times, resistance can be developed to clotrimazole in vitro, but this resistance is readily reversible upon passage in drug-free broth. The degree of in vivo activity of clotrimazole against
Candida
depends on the severity of infection used. Orally it appears to be more effective when administered by gavage than when given mixed in the diet. Pretreatment with the agent may decrease its efficacy because of drug inactivation. Against dermatophytes, clotrimazole has a degree of activity similar to griseofulvin when given orally, but it is less active than tolnaftate topically in cutaneous infection of
Trichophyton mentagrophytes
in guinea pigs. In vitro, but not in vivo, some gram-positive and gram-negative bacteria are inhibited by low concentrations of clotrimazole.
Cephapirin: In Vitro Antibacterial Spectrum
Authors: Axelrod Judith , Meyers Burt R. , Hirschman Shalom Z.
Published: December 2020

Cephapirin, a new semisynthetic cephalosporin derivative, was found to have an antibacterial spectrum similar to that of cephalothin.
Staphylococcus aureus
was inhibited by cephapirin concentrations of 0.09 to 12.5 μg/ml.
S. epidermidis, S. viridans, S. pyogenes,
and
Diplococcus pneumonia
isolates were inhibited by less than 1 μg/ml. The
Enterococcus
required a concentration of 25 μg of antibiotic per ml for inhibition. Approximately 65% of
Escherichia coli,
and all
Klebsiella,
indole-negative
Proteus,
and
Salmonella
strains tested were inhibited by the drug.
Serratia, Pseudomonas
, indole-positive
Proteus
, and
Erwinia
strains were highly resistant. Inoculum size was not an important factor in determining the level of sensitivity of
S. aureus
to cephapirin. The antibiotic does not appear to be significantly bound to serum protein. In vitro development of resistance to the drug was demonstrated with two isolates of
S. aureus
.
Epidemiological Surveillance of
Serratia marcescens
Infections by Bacteriocin Typing
Authors: Traub Walter H. , Raymond Ella A.
Published: December 2020

During 10 months, 155 isolates of
Serratia marcescens
were cultured from 105 patients, of whom 49 were considered to have significant infection. The 155 isolates were typed by bacteriocin sensitivity, and 137 (88.4%) were assigned to 37 provisional bacteriocin groups; 18 isolates were nontypable. No major outbreaks of nosocomial infection were demonstrable; however, there were four chronologically separate minor episodes of cross-infection that involved two or three patients per room or unit, respectively.
Comparison of Three Methods Used to Isolate Dengue Virus Type 2
Authors: Chappell W. Adrian , Calisher Charles H. , Toole Roberta F. , Maness Kathryn C. , Sasso Donna R. , Henderson Brian E.
Published: December 2020

During the 1969 dengue epidemic in Puerto Rico, human sera and
Aedes aegypti
mosquitoes were collected for virus isolation and identification. Three methods of isolation were used and compared. In the first method, we inoculated newborn mice by the intracranial route, noted any signs of illness, and serially passed specimens in mice until virus was isolated. In the second method, we inoculated tube cultures of LLC-MK
2
cells, noted any cytopathic effect (CPE), and assayed fluids for virus by plaque formation in LLC-MK
2
cell monolayers. The third method was different from the second only in that the original specimens were first inoculated into fluid cultures of Singh's
A. albopictus
cells. No significant CPE was seen in LLC-MK
2
cultures; however, distinct syncytial CPE was observed in
A. albopictus
cells. About the same number of virus isolates were made in each isolation system. Virus isolates from both sera and mosquitoes were identified as dengue type 2 by a plaque-reduction neutralization test in LLC-MK
2
cells. The utility of the three methods, individually or in combination, is discussed and related to diagnostic and epidemic situations.
Phenol Concentrations in the Air from Disinfection Solutions
Authors: Braymen D. T. , Songer J. R.
Published: December 2020

Phenol concentrations in the air near phenol disinfectant solutions were measured. The concentration of phenol was not excessive, except for hot solutions with which exposure would normally be for a very short time. Adverse physiological reactions may occur at air levels below the threshold limit values which may be especially hazardous to those persons exposed to organisms causing respiratory diseases.
Long-Term Preservation of
Bordetella pertussis
Authors: Eckert Herbert L. , Flaherty Dennis K.
Published: December 2020

Viability of
Bordetella pertussis
was preserved when glycerol broth suspensions were quick frozen and stored at -70 C for as long as 45 months.
In Vitro Evaluation of Actinobolin as an Antibiotic for the Treatment of Periodontal Disease
Authors: Armstrong P. J. , Hunt D. E.
Published: December 2020

Actinobolin was evaluated in vitro by a paper disc-agar diffusion method for inhibitory activity against mixed microbial cultures obtained from patients with periodontal disease and against pure bacterial cultures tentatively identified as strains of
Bacteroides melaninogenicus, Fusobacterium fusiforme, Leptotrichia buccalis
, and
Veillonella parvula
. Every culture tested was inhibited to some degree by actinobolin. These observations suggest that actinobolin may be effective in the treatment of periodontal disease.
Effect of a Modified Kaolin Treatment on Serum Immunoglobulins
Authors: Inouye Sakae , Kono Reisaku
Published: December 2020

After kaolin treatment of fetal rabbit serum, 7
S
antibody titers were reduced more than 19
S
titers. This reduction was less when the kaolin treatment was performed at
p
H 9.0 than when it was performed at
p
H 7.3. A modification of the kaolin treatment of sera for use in the hemagglutination-inhibiting antibody titration, in which the hemagglutination reaction is performed at a neutral
p
H, is recommended. The advantage of the modified method is that adsorption of immunoglobulins to kaolin is minimized when serum is treated at a lower dilution with
p
H 9.0 kaolin, followed by reduction of the
p
H of the supernatant fluid to neutrality with a “serum adjusting diluent.” When the serum was diluted with physiological saline before kaolin treatment, a great decrease in serum immunoglobulin concentrations occurred. This decrease was found to be less in the modified kaolin treatment than in the conventional
p
H 7.3 kaolin treatment.
Potential Pathogens in the Environment: Isolation, Enumeration, and Identification of Seven Genera of Intestinal Bacteria Associated with Small Green Pet Turtles
Authors: McCoy R. H. , Seidler Ramon J.
Published: December 2020

Bacteriological analyses were performed on fecal swabs and the aquarium water of 27 individually purchased specimens of the small green pet turtle,
Pseudemys scripta elegans
. Representatives of
Aeromonas, Citrobacter, Enterobacter, Klebsiella, Proteus, Salmonella
, and
Serratia
were isolated.
Enterobacter, Klebsiella
, and
Salmonella
were encountered in 20% or more of the specimens, whereas
Aeromonas
was isolated from 63%.
Klebsiella pneumoniae
counts ranged from 10
3
to 10
4
per milliliter of aquarium water, whereas
Aeromonas
routinely exceeded 10
4
per milliliter.
Aeromonas
cultures from turtles were identical to 7 human isolates in some 29 biochemical tests. On the basis of our findings, we question whether the
Salmonella
-free certification program alone is sufficient to render these reptiles as safe pets.
Quantitative Assessment of Hemadsorption by Myxoviruses: Anti-Immunoglobulin G Hemadsorption-Inhibition Test
Authors: Hahon Nicholas , Stewart John D. , Eckert Herbert L.
Published: December 2020

A quantitative hemadsorption-inhibition test was developed to estimate myxovirus serum antibodies within 24 h by determining the serum dilution inhibiting hemadsorption in 50% of the infected cells. The test depends on the interactions of virus-infected cell monolayers with antiviral serum and of the resultant complexes with antiimmunoglobulin G serum. The incorporation of species-specific anti-immunoglobulin G serum into the test significantly increased sensitivity.
Rapid Solid-Phase Radioimmunoassay for Staphylococcal Enterotoxin A
Authors: Collins William S. , Johnson Anna D. , Metzger Joseph F. , Bennett Reginald W.
Published: December 2020

A rapid solid-phase radioimmunoassay for staphylococcal enterotoxin A is described. The assay procedure requires 3 to 4 h for completion by using a competitive inhibition system in which the antibody is attached to bromacetyl cellulose particles. It is accurate to a level of 0.01 μg of enterotoxin A/ml in a variety of media such as ham, milk products, crab meat, custard, etc. No significant interference was found with any media or food product tested.
Growth of
Acinetobacter calcoaceticus
on Ethanol
Authors: Abbott Bernard J. , Laskin A. I. , McCoy C. J.
Published: December 2020

A soil microorganism, identified as
Acinetobacter calcoaceticus
, was cultivated on ethanol as a sole source of carbon. This organism grew with a maximum specific growth rate of 0.7/h. The pH optimum for growth was between 6.5 and 7.5, and the temperature optimum was between 32 and 35 C. Ethanol metabolism by this organism was inducible by ethanol, and the presence of acetate led to the repression of ethanol dehydrogenase. At higher cell densities the cessation of growth on ethanol was accompanied by the accumulation of acetate or acetaldehyde, or both. These accumulations were attributed to a reduction in the magnesium or sulfur content of the medium and a lack of feedback inhibition by acetate of alcohol dehydrogenase.
Automated Detection of
Haemophilus influenzae
Authors: Larson Steven M. , Charache Patricia , Chen Marianne , Wagner Henry N.
Published: December 2020

Addition of heme (X factor) and pyridine nucleotide (V factor) to the medium permits rapid growth of
Haemophilus influenzae
, with evolution of easily detectable amounts of
14
CO
2
. Radiometric media containing X and V factor should be used when evaluating clinical specimens which might contain
Haemophilus
species.
Identification of the Volatile Compounds Produced in Sterile Fish Muscle (
Sebastes melanops
) by
Pseudomonas fragi
Authors: Miller A. , Scanlan R. A. , Lee J. S. , Libbey L. M.
Published: December 2020

Volatile compounds produced by
Pseudomonas fragi
strain 18 in sterile fish muscle (
Sebastes melanops
) were identified by combined gas-liquid chromatography and mass spectrometry. Compounds positively identified included dimethyl sulfide, acetaldehyde, ethyl acetate, ethyl alcohol, and dimethyl disulfide. Methyl mercaptan, ethyl butyrate, ethyl hexanoate, and butanone were tentatively identified by relative retention times of the authentic compounds. The fruity odor that developed in fish muscle during incipient spoilage was attributed to a synergistic flavor interaction involving the ethyl esters of acetate, butyrate, and hexanoate.
Characterization of Mild Thermal Stress in
Pseudomonas fluorescens
and Its Repair
Authors: Gray Rodney J. H. , Witter Lloyd D. , Ordal Z. John
Published: December 2020

The exposure of exponentially growing
Pseudomonas fluorescens
P7 cells to heating at 36 C for 2 h in a defined medium, followed by cooling to 25 C and further incubation at this, the optimal growth temperature, resulted in the apparent death of approximately 99% of the cells, as determined by their inability to form colonies on Trypticase soy agar. Continued incubation at 25 C resulted in an extremely rapid increase in the Trypticase soy agar count, demonstrating that the phenomenon observed was not death but rather injury. Presumptive evidence of heat-stimulated ribonucleic acid (RNA) degradation and membrane damage was provided by the observed loss of 260-nm absorbing materials. Confirmation of RNA degradation was obtained by colorimetric analysis. Ribosomal RNA from normal and injured cells, which was electrophoretically separated on polyacrylamide gels, revealed that the 23
S
and 16
S
species were only partially destroyed. Inhibitor studies demonstrated, however, that RNA synthesis was necessary for recovery. The unusual accumulation of 17
S
RNA during recovery pointed to the presence of a heat-induced lesion in the RNA maturation process. A thermally induced membrane lesion is also discussed.
Filtration Methods for Recovering Enteroviruses from Foods
Authors: Kostenbader K. D. , Cliver D. O.
Published: December 2020

A set of simple, rapid filtration methods has been developed for recovering enteroviruses from foods. The methods employ quite inexpensive equipment, and the resulting extract might be concentrated in any of several ways. Three model enteroviruses were apparently recovered with at least 80% efficiency when inoculated, at levels ranging from thousands to one plaque-forming unit per 20-g sample, into eleven foods representing six major food groups.
Effects of Various Gases on the Survival of Dried Bacteria During Storage
Authors: Marshall Betty J. , Coote G. G. , Scott W. J.
Published: December 2020

Salmonella newport
and
Pseudomonas fluorescens
were dried together in papain digest broth and sucrose-glutamate, and stored in several gases at various water activities (

a
w

) between 0.00 and 0.40 at 25 C for various periods up to 81 weeks. Both
S. newport
and
P. fluorescens
, dried in papain digest broth and stored in air, died rapidly if the conditions were very dry (0.00

a
w

) or moist (0.40

a
w

). Storage in carbon dioxide and argon gave greater survival than storage in air but lower survival than did storage in nitrogen or in vacuo. When the organisms were dried in a sucrose-glutamate mixture the differences between the gases were very small, and variations in residual water were less important. Of the inert gases, argon gave the best survival when the organisms were dried in papain digest broth, especially at 0.00

a
w

; the survival in neon and krypton was lower and in xenon and helium it was much lower.
Detection and Identification of Diagnostic
Histoplasma capsulatum
Precipitates by Counterelectrophoresis
Authors: Kleger Bruce , Kaufman Leo
Published: December 2020

Studies were carried out to develop and evaluate a counterelectrophoresis (CEP) technique for the rapid and specific identification of the diagnostically important histoplasmosis H and M precipitin bands. Well-defined and centrally located precipitin bands were produced by using a discontinuous buffer system and a gel matrix composed of agarose and ionagar no. 2. A template was devised which allowed the selective identification of the H and M precipitins. Comparative evaluations were performed with the microimmunodiffusion (ID) and complement fixation tests. In 52 sera from persons with histoplasmosis, either the H or M precipitin, or both, were identified in 42 (81%) of the cases with the CEP technique and in 43 (83%) with the ID test. With sera from 28 persons with heterologous diseases, the CEP technique, like the ID test, failed to react. The specificity of the CEP technique was dependent upon the use of the identity template. The CEP technique is recommended for routine use in laboratories testing moderate numbers of sera. It provides accurate and reproducible results within 90 min, in contrast to the ID test, which requires 18 to 24 h.
Comparison of Gelman and Millipore Membrane Filters for Enumerating Fecal Coliform Bacteria
Authors: Presswood William G. , Brown Lynn R.
Published: December 2020

Tests of two leading brands of membrane filters used for enumerating fecal coliform bacteria showed that Gelman GN-6 filters recovered statistically more colonies of bacteria than did Millipore HAWG 047SO filters from pure cultures incubated at either 35 C (the optimal growth temperature) or 44.5 C (the standard temperature for the fecal coliform test). Standard membrane filter procedures with M-FC broth base were used to enumerate the organisms. Densities of colonies incubated on Gelman filters at 44.5 C averaged 2.3 times greater than those on Millipore filters. Plate counts of the bacteria at both temperatures indicated that incubation at 44.5 C did not inhibit propagation of fecal coliform bacteria. For the pour plates, M-FC broth base plus 1.5% agar was used. This modified medium compared favorably to plate count agar for enumerating
Escherichia coli
. At 35 and 44.5 C, colony counts on Gelman filters agreed closely with plate counts prepared concurrently, but Millipore counts were consistently lower than plate counts, especially at 44.5 C. Comparative analyses of river water for fecal coliform bacteria by the membrane filter technique gave results comparable to those for the pure cultures.
Serological Examination of Some Strains That Are in the
Mycobacterium avium-intracellulare-scrofulaceum
Complex But Do Not Belong to Schaefer's Serotypes
Authors: Reznikov M. , Dawson David J.
Published: December 2020

One hundred strains belonging to the
Mycobacterium avium-intracellulare-scrofulaceum
(MAIS) complex but not agglutinating with antisera type-specific for Schaefer's 23 MAIS serotypes were examined using antisera against seven other such strains. Four of the 100 strains were found to be of the same serotype as one of the 7 against which antisera were prepared; 4 other strains were of the same serotype as another of those against which antisera were prepared. Although the strains against which antisera were prepared were serologically distinct from each other, no strains serologically identical to 5 of them were found. This suggests that numerous serotypes might have to be defined if strains such as those examined are to be assigned to their respective serotypes.
Concentration of Enteroviruses from Large Volumes of Water
Authors: Sobsey Mark D. , Wallis Craig , Henderson Marilyn , Melnick Joseph L.
Published: December 2020

An improved method for concentrating viruses from large volumes of clean waters is described. It was found that, by acidification, viruses in large volumes of water could be efficiently adsorbed to epoxy-fiber-glass and nitrocellulose filters in the absence of exogenously added salts. Based upon this finding, a modified version of our previously described virus concentration system was developed for virus monitoring of clean waters. In this procedure the water being tested is acidified by injection of N HCl prior to passage through a virus adsorber consisting of a fiber-glass cartridge depth filter and an epoxy-fiber-glass membrane filter in series. The adsorbed viruses are then eluted with a 1-liter volume of pH 11.5 eluent and reconcentrated by adsorption to and elution from a small epoxy-fiber-glass filter series. With this method small quantities of poliovirus in 100-gallon (378.5-liter) volumes of tapwater were concentrated nearly 40,000-fold with an average virus recovery efficiency of 77%.
Plaque Assay for Polyoma Virus on Primary Mouse Kidney Cell Cultures
Authors: Consigli Richard A. , Zabielski Janusz , Weil Roger
Published: December 2020

A plaque assay for polyoma virus using primary baby mouse kidney cells is reported.
Potential Production of Sterigmatocystin on Country-Cured Ham
Authors: Halls N. A. , Ayres J. C.
Published: December 2020

In laboratory media, 10 of 16 isolates of
Aspergillus versicolor
from country-cured ham were capable of producing sterigmatocystin. Three of these isolates were tested and found to produce sterigmatocystin on country-cured ham after 14 days of incubation at 20 or 28 C.
Measurement of Product Temperature by Use of an Infrared Thermometer
Authors: Mahnke C. W. , Soucheck J. A. , Insalata N. F.
Published: December 2020

An infrared sensor system to measure product surface temperature in industrial food processes is described. The method is suitable for use in either manufacturing plant or laboratory equipment. Good correlation can be expected between experimental and plant temperature readings.
Screening Plate Method for Detection of Bacterial β-Glucuronidase
Authors: Dahlén Gunnar , Linde Anders
Published: December 2020

For screening tests of bacterial β-glucuronidase (EC 3.2.1.31) activity an agar plate (MUG plate) containing the enzyme substrate, 4-methylumbelliferyl-β-D-glucuronide, was developed. In the presence of β-glucuronidase, the strongly fluorescent 4-methylumbelliferone, which can be detected by ultraviolet light, was liberated. For tests of fastidious bacteria, the MUG-plate was enriched with supplements containing heat-labile growth factors without influencing the reaction. The plate was found to be suitable for screening tests. The sensitivity of the MUG-plate was determined by means of fluorimetric method. With the present method, β-glucuronidase activities were demonstrated in some well-known β-glucuronidae-producing microorganisms as well as in
Bacteroides
and
Corynebacterium
spp.
Heat Injury and Recovery of Vegetative Cells of
Clostridium botulinum
Type E
Authors: Pierson M. D. , Payne S. L. , Ades G. L.
Published: December 2020

Vegetative cells of
Clostridium botulinum
type E (Tenno) were heated at 40.5 C in a prereduced peptone-yeast extract broth (PY). During the heating period, cell numbers remained essentially constant for 3 h as indicated by roll tube counts in PY agar (PYA); however, injury and recovery from injury were observed when the cells were enumerated using PYA containing either 0.06 or 0.07% bile salts.
Distribution of Zearalenone-Producing
Fusarium
Species in Japan
Authors: Ishii Kenji , Sawano Megumi , Ueno Yoshio , Tsunoda Hiroshi
Published: December 2020

One hundred sixty-six isolates of
Fusarium
spp. from domestic cereal grains, feed, and other sources were examined for their ability to produce zearalenone on autoclaved moist rice grains. They belonged to the following species (number of producers/number tested):
F. roseum
(9/28),
F. roseum
(Culmorum) (3/4),
F. roseum
(Gibbosum) (2/5),
F. roseum
(Avenaceum) (1/2),
F. roseum
(Scirpi) (0/1),
F. tricinctum
(1/4),
F. tricinctum
(Sporotrichiella) (0/7),
F. lateritium
(1/1),
F. episphaeria
(0/2),
F. moniliforme
(0/3),
F. oxysporum
(0/12),
F. rigidiusculum
(0/4),
F. solani
(0/4),
F. splendens
(0/1),
F. nivale
(0/2), and
Fusarium
spp. (15/86). Zearalenone was isolated from molded rice by ethanol extraction and purified by column chromatography. Selected isolates of
F. roseum
M-3-2 and
F. roseum
(Gibbosum) A-O-2 produced 50 to 100 mg of zearalenone per kg of rice. Increased yields (250 to 407 mg/kg of rice) were obtained by
F. roseum
M-3-2 when the substrate was supplemented with 1% peptone.