bluuebunny/crossref_metadata_2025 huggingface dataset:
Alternative quality control parameters for Autobac susceptibility testing disks: use of agar diffusion zone size results
Authors: Boshard R , Matsen J M
Published: January 2020

Persistent concerns about limitation in the assessment of the quality control of Autobac 1 (Pfizer Diagnostics Division, Groton, Conn.) led us to investigate an alternative method for monitoring the performance of Autobac susceptibility testing disks. Current methodology for quality control of the system provides data which are interpreted at the high end of a numerical scale; e.g., the control strain of Escherichia coli consistently exhibits a light-scattering index value of 1.00 for all antibiotics tested. This type of end-of-scale criterion may not detect individual antibiotic disk aberrations of individual clinical isolate susceptibilities. Disk diffusion testing allows a semiquantitative, continuous-scale determination and will detect test performance variations, unless the control strain is highly resistant. During a 6-month period daily quality control procedures for 10 Autobac antibiotics tested against control strains of E. coli and Pseudomonas aeruginosa were monitored, utilizing both Autobac 1 recommendations and disk diffusion susceptibility (Kirby-Bauer) methodology. Readings were carried out by one of six technologists. Zone sizes were within a range of +/- 3 mm of a mean value of 99% of the tests with E. coli and within +/- 3 mm for 98% of the tests with Pseudomonas. Reproducibility was excellent. The high reproducibility may be due to the disk manufacturing process, which provides rigorous disk preparation and acceptability standards, to strict laboratory storage procedure, and to our own careful assessment of disk cartridges before their use for clinical susceptibility testing. We recommend that each new cartridge be tested in this manner and that a similar procedure be considered for other automated procedures in which disks are used.
Long-term infections with Campylobacter fetus subsp. jejuni
Authors: Richardson N J , Koornhof H J , Bokkenheuser V D
Published: January 2020

Seventy-three apparently healthy, rural South African schoolchildren 6 to 8 or 13 to 16 years of age were examined five times over a 16-month period for fecal pathogens. Nine were positive for Campylobacter fetus subsp. jejuni. The organism was isolated intermittently from six children for at least 9 months and from three children for more than 1 year. Five of the long-term infections occurred among the 46 children aged 6 to 8 years (10.9%) versus one long-term infection among the 27 children aged 13 to 16 years (3.7%). It is not possible with present microbiological techniques to make a clear-cut distinction between reinfected subjects and chronic carriers.
Reverse enzyme immunoassay for detection of specific anti-Toxoplasma immunoglobulin M antibodies
Authors: Franco E L , Walls K W , Sulzer A J
Published: January 2020

A reverse enzyme immunoassay (R-EIA) is described, in which polystyrene muplates are sensitized with anti-immunoglobulin M (IgM) (mu chain) antibodies and then sequentially allowed to react with patient's serum, peroxidase-labeled Toxoplasma gondii soluble antigen, and substrate. Measurement of activity of the solid-phase bound enzyme conjugate was done by colorimetric reading of the final developed color and kinetically by the initial rate of color development. This R-EIA allowed full resolution between absorbance values of a group of 36 sera which presented positive results in the Toxoplasma IgM immunofluorescence test and the remaining groups, which consisted of 39 normal individuals, 22 rheumatoid factor-positive sera, 8 Waldenstrom's macroglobulinemic sera, 3 infectious mononucleosis samples, and 6 high-titered IgG anti-T. gondii sera. No interference of rheumatoid factor IgM or inhibition by high-titered specific IgG was detected, even in the false IgM immunofluorescence-positive rheumatoid factor samples. Likewise, false-negative IgM immunofluorescence samples gave positive R-EIA even without adsorption with Staphylococcus aureus protein A. The possibility of direct tagging of the antigen with the enzyme eliminates the need for using antigen and anti-antigen conjugates as separate layers, therefore eliminating one step in the assay.
Gas-chromatographic analysis of mycolic acid cleavage products in mycobacteria
Authors: Guerrant G O , Lambert M A , Moss C W
Published: January 2020

Mycolic acids were detected in both reference strains and clinical isolates of mycobacteria using gas chromatography of fatty acid methyl esters prepared by acid methanolysis. The methyl esters were extracted with hexane, concentrated, and analyzed with a gas chromatograph by using two different injector temperatures. When the samples were analyzed at high injector temperatures of 300 to 350 degrees C, characteristic thermal cleavage products from mycolic acids, C22:0, C24:0, or C26:0 fatty acid methyl esters, were detected. When analyzed at injector temperatures of 235 degrees C or lower, the mycolic acids were heat stable and the characteristic methyl ester cleavage products were not observed.
Evaluation of rapid radiometric method for drug susceptibility testing of Mycobacterium tuberculosis
Authors: Siddiqi S H , Libonati J P , Middlebrook G
Published: January 2020

A total of 106 isolates of Mycobacterium tuberculosis were tested for drug susceptibility by the conventional 7H11 plate method and by a new rapid radiometric method using special 7H12 liquid medium with 14C-labeled substrate. Results obtained by the two methods were compared for rapidity, sensitivity, and specificity of the new test method. There was 98% overall agreement between the results obtained by the two methods. Of a total of 424 drug tests, only 8 drug results did not agree, mostly in the case of streptomycin. This new procedure was found to be rapid, with 87% of the tests results reportable within 4 days and 98% reportable within 5 days as compared to the usual 3 weeks required with the conventional indirect susceptibility test method. The results of this preliminary study indicate that the rapid radiometric method seems to have the potential for routine laboratory use and merits further investigations.
Kluyvera, a new (redefined) genus in the family Enterobacteriaceae: identification of Kluyvera ascorbata sp. nov. and Kluyvera cryocrescens sp. nov. in clinical specimens
Authors: Farmer J J , Fanning G R , Huntley-Carter G P , Holmes B , Hickman F W , Richard C , Brenner D J
Published: January 2020

Kluyvera is proposed as a new genus for the group of organisms formerly known as Enteric Group 8 (synonym = API group 1). Strains of Kluyvera share the properties of most members of the family Enterobacteriaceae: they are gram-negative rods, motile with peritrichous flagella, catalase positive, and oxidase negative; they grow on MacConkey agar, ferment D-glucose with the production of acid and gas, and are susceptible to many antibiotics. Strains are usually indole positive, methyl red positive, Voges-Proskauer negative, citrate positive, H2S (triple sugar iron) negative, urea negative, phenylalanine deaminase negative, lysine decarboxylase positive, arginine dihydrolase negative, and ornithine decarboxylase positive. Kluyvera strains ferment many of the sugars and polyhydroxyl alcohols used in identification. By deoxyribonucleic acid-deoxyribonucleic acid hybridization, strains of Kluyvera were divided into three groups. Kluyvera ascorbata is proposed as the type species for the genus. Most strains of K. ascorbata have been isolated from clinical specimens. K. cryocrescens is proposed as the second species. It was occasionally isolated from clinical specimens, but it was isolated more commonly from the environment. Kluyvera species group 3 was heterogeneous, but was distinct from the two named species by deoxyribonucleic acid hybridization. This group was rare, so no species name will be proposed at this time. K. ascorbata can be differentiated from K. cryocrescens by its positive ascorbate test, inability to grow at 5 degrees C in a refrigerator, and smaller zones of inhibition around carbenicillin and cephalothin disks. The test normally used for identification does not clearly differentiate these two species. Kluyvera species are probably infrequent opportunistic pathogens. The most common source is sputum, where they are probably not clinically significant. Five strains have been from blood cultures. More information is needed about the incidence and clinical significance of the genus Kluyvera.
Highly sensitive assay for Clostridium perfringens enterotoxin that uses inhibition of plating efficiency of Vero cells grown in culture
Authors: McDonel J L , McClane B A
Published: January 2020

A highly sensitive and reproducible biological assay for Clostridium perfringens enterotoxin is described that uses Vero (African green monkey kidney) cells grown in tissue cultures. Very small doses of the enterotoxin inhibited the plating efficiency of the cells. This inhibition of plating efficiency could be used to detect as little as 0.1 ng (1 ng/ml) of enterotoxin, and a linear dose-response curve was obtained with 0.5 to 5 ng (5 to 50 ng/ml). A nonlinear, but reproducible, curve was obtained with a dose range from 0.1 to 100 ng (1 to 1,000 ng/ml). A new unit of biological activity, called the plating efficiency unit, was defined as that amount of enterotoxin that caused a 25% inhibition of the plating of 200 cells inoculated into 100 microliters of medium in a microwell culture system. One milligram of highly purified enterotoxin contained about 400,000 plating efficiency units. Additional studies demonstrated that the biological and serological activities of the enterotoxin molecule were not equally labile.
Comparison of fluorescent-antibody, neutralizing-antibody, and complement-enhanced neutralizing-antibody assays for detection of serum antibody to respiratory syncytial virus
Authors: Kaul T N , Welliver R C , Ogra P L
Published: January 2020

A comparison of three assays for the detection of serum antibody to respiratory syncytial virus (RSV) was carried out on 47 serum samples obtained sequentially from infants and young children with RSV infection. Neutralizing-antibody (NA) activity was determined by a semimicromethod of plaque reduction. Complement-enhanced NA activity was determined by the addition of guinea pig complement to NA assays. RSV antibody responses in immunoglobulin G, immunoglobulin M, and immunoglobulin A classes were determined by using indirect immunofluorescence techniques for fluorescent-antibody (FAb) assay. Antibody to RSV was detectable by all three techniques as early as 4 days after the onset of illness. At all phases of illness, titers obtained by complement-enhanced NA assays were significantly greater than those obtained by NA or FAb assays (P less than 0.01). RSV-FAb titers determined in the immunoglobulin G class correlated well with those determined by complement-enhanced NA or NA assays. The data suggest that the FAb assay for detection of RSV antibody in serum is somewhat less sensitive but also less laborious and more rapid than NA assays.
Use of New York City medium for improved recovery of Neisseria gonorrhoeae from clinical specimens
Authors: Granato P A , Schneible-Smith C , Weiner L B
Published: January 2020

New York City (NYC) and Martin-Lewis (ML) media were evaluated comparatively for their ability to support the growth of Neisseria gonorrhoeae from clinical specimens. A total of 1,010 urethral, cervical, pharyngeal, and rectal specimens were collected from walk-in patients attending a clinic for sexually transmitted diseases. A total of 187 and 165 isolates of gonococci were cultivated on NYC and ML media, respectively, with 161 of these isolates being recovered on both media. Overall, the use of NYC medium resulted in a 13.3% increased recovery rate of gonococci. When gonococci were recovered on both media from primary isolation, the NYC medium supported a more luxuriant growth and a greater number of colonies, which usually resulted in the detection of positive cultures 1 day sooner than on ML medium. Both media were comparable in their ability to suppress the growth of saprophytic microorganisms. The results of this study demonstrated that the use of NYC medium markedly enhanced the recovery of N. gonorrhoeae from clinical specimens as compared to ML medium.
Clinical manifestations of diarrhea in calves infected with rotavirus and enterotoxigenic Escherichia coli
Authors: Tzipori S R , Makin T J , Smith M L , Krautil F L
Published: January 2020

The susceptibility of gnotobiotic, colostrum-derived, or suckling calves to four bovine rotavirus isolates was found to be age dependent. Calves older than 7 days remained clinically normal, although they excreted virus in their feces and subsequently developed antibody against the virus, Enterotoxigenic Escherichia coli, fed to gnotobiotic, colostrum-deprived, or suckling calves ranging in age from a few hours to 26 days old, only caused diarrhea in animals younger than 24 h old. In contrast, diarrhea was consistently induced in 1- and 2-week-old calves infected with both enterotoxigenic E. coli and rotavirus. In general, diarrhea appeared after a rotavirus incubation period of approximately 3 days and was independent of the order in which the two microbial agents were given, the age of the calf, or the level of circulating rotavirus antibodies. The disease episode coincided with the excretion of rotavirus, rather than enterotoxigenic E. coli, in the feces. Infection with enterotoxigenic E. coli became established within 24 h of inoculation, and in older calves enterotoxigenic E. coli was often excreted in very small numbers and for a longer period than rotavirus.
Follow-up study of pharyngeal carriers of beta-hemolytic streptococci among school children in Sapporo City during a period of 2 years and 5 months
Authors: Maekawa S , Fukuda K , Yamauchi T , Yamaguchi T , Takahashi K , Sugawa K
Published: January 2020

A total of 124 normal school children in three classes (aged 8 to 9) were examined for beta-hemolytic streptococci for 29 months from August 1977 to December 1979 be means of serial monthly throat cultures. No significant difference between the carrier rate of boys and that of girls was observed. Although no monthly variation of carrier rates appeared in class II, marked temporal increases of carrier rates appeared from June 1978 (in Class I) and from August 1978 (in class III) in August 1979. These periodical variations of carrier rates observed in this investigation do not coincide with the low-in summer and high-in winter seasonal variations which has generally been observed by many other investigators. The average values of carrier rates throughout the period of this investigation were 30.9, 29.7, and 24.5% in classes I, II, and III, respectively. The carrier rate of group A streptococci by month and by class showed some positive correlation with the carrier rate of total beta-hemolytic streptococci. T-type 4 and T-untypable strains were not identified up to a certain period; then each strain appeared at a given time during the course of our investigation in one class, spread to all three classes, and continued to be isolated until the end of this investigation. The origin of these type of strains could not be identified in this study. Of the children, 36 (29.0%) never became streptococcal carriers during the period of examination and 88 (71.0%) became streptococcal carriers at least one time during the 29 examinations; among these positive carriers, 29 children (23.0%) showed positive results in more than 50% of the examinations.
Freeze-dried erythrocytes for an indirect hemagglutination test for detection of cytomegalovirus antibodies
Authors: Cabau N , Crainic R , Duros C , Denoyel G , Gaspar A , Bronnert C , Boué A , Horodniceanu F
Published: January 2020

An indirect hemagglutination test with lyophilized, fixed, tanned, and cytomegalovirus (CMV)-sensitized sheep erythrocytes for the detection of CMV antibodies is reported. To avoid nonspecific hemagglutination, cells were fixed with glutaraldehyde or Formalin directly in whole blood. The lyophilized, CMV-sensitized erythrocytes obtained by this technique were stable up to 9 months at 37 degrees C and retained the same reactivity at fresh, CMV-sensitized cells. Indirect hemagglutination performed with lyophilized, sensitized cells was highly efficient in detecting CMV-antibodies as compared with complement fixation and enzyme immunoassay.
Isolation of Pasteurella ureae from reproductive tracts of congenic mice
Authors: Ackerman J I , Fox J G
Published: January 2020

Infertility noted in two congenic strains of mice was associated with abortion, metritis, and stillbirths. Pasteurella pneumotropica was recovered from affected uterine tracts of ATL mice. Tetracycline treatment for 6 weeks was instituted in an attempt to minimize Pasteurella-associated infertility. Nine ATL mice and 12 ATH mice were examined 4 and 12 months after cessation of tetracycline therapy, respectively. Histopathologically, all animals appeared normal. P. pneumotropica was recovered from six of nine prepuces of both ATH and ATL mice; similarly, two of three vaginal culture of the ATL mice yielded this bacterium. Pasteurella ureae was isolated from three of eight reproductive tracts of the female ATH mice, Negative indole and ornithine decarboxylase reactions and positive acid production for mannitol differentiated P. ureae from P. pneumotropica. This report represents the first confirmed isolation of P. urea from animals. Biochemical profiles of atypical strains of P. pneumotropica isolated from animals are discussed and compared with those of P. ureae. The need for careful biochemical characterization of all Pasteurella isolated from rodents is emphasized.
Role of pH in oxidase variability of Aeromonas hydrophila
Authors: Hunt L K , Overman T L , Otero R B
Published: January 2020

Some strains of Aeromonas hydrophila may be oxidase negative or only weakly oxidase positive by the Kovacs method taken from the surface of a differential medium, such as MacConkey agar. Six strains of A. hydrophila, two oxidase variable, one oxidase constant, and three weakly oxidase positive on MacConkey agar, were studied to determine the cause of oxidase variability. The bacteriostatic dyes in MacConkey agar were considered possible inhibitors of the oxidase reaction. The concentration of these dyes was varied from twice the normal concentration in zero. No change in the oxidase reaction of any of the six strains was noted. Carbohydrate utilization was also studied. When lactose was deleted from the MacConkey agar formula, the oxidase-variable and weakly oxidase-positive stains become strongly oxidase positive. When glucose was substituted for lactose in the MacConkey agar formula, all strains became oxidase negative. Substitution of nonfermentable carbohydrates, such as dulcitol or raffinose, returned all strains to the oxidase-positive state. When trehalose, which is utilized by all of the strains, was substituted for lactose, the oxidase-variable strains and two of the three weakly oxidase-positive strains became oxidase negative. The other weakly oxidase-positive strain remained weakly positive and the oxidase-constant strain remained strongly oxidase positive when trehalose was substituted for lactose. Oxidase reactions were found to be negative when the pH of the medium was 5.1 or lower. Negative oxidase reactions could be reversed by raising the pH above 5.2, and positive oxidase reactions could be reversed by lowering the pH to 5.1. Therefore, the fermentation of lactose in MacConkey agar results in the inhibition of the oxidase reaction. The acid end products of the fermentation of lactose include acetic, formic, lactic, oxaloacetic, pyruvic, and succinic acids.
Pseudomonas paucimobilis bacteremia
Authors: Southern P M , Kutscher A E
Published: January 2020

Pseudomonas paucimobilis was isolated from blood of a man after surgery for occlusive vascular disease of his lower extremities. Circumstances suggest that the infection was hospital associated and was possibly caused by an organism present in the surroundings of this particularly susceptible host. An environmental source was found. The isolate was susceptible in vitro to carbenicillin, chloramphenicol, tetracycline, and trimethoprim-sulfamethoxazole and was moderately susceptible to amikacin and ampicillin. This case represents the fourth report incidence of infection due to P. paucimobilis.
Use of agarose gel electrophoresis of plasmid deoxyribonucleic acid to fingerprint gram-negative bacilli
Authors: Schaberg D R , Tompkins L S , Falkow S
Published: January 2020

Agarose gel electrophoresis of the plasmid deoxyribonucleic acids from 60 gram-negative bacilli recovered during investigations of nosocomial epidemics was used to fingerprint the strains. This method was as specific at differentiating bacterial strains as more conventional phenotyping methods. In all cases, plasmid band fingerprints of epidermic strains isolates were identical whereas coisolate plasmid deoxyribonucleic acid patterns were different. Agarose gel electrophoresis of plasmid deoxyribonucleic acid is proposed as a method which can be used in conventional microbiology laboratories as an adjunct to or, possibly, replacement for other methods of identifying bacterial strains.
Acid-fast microscopy on polycarbonate membrane filter sputum sediments
Authors: Smithwick R W , Stratigos C B
Published: January 2020

Polycarbonate membrane filters were used to concentrate 916 sputum specimens for detecting acid-fast bacilli by microscopic examination. These results were compared with those of smears prepared from centrifugates and direct smears of the same specimens. Culture isolation, the control procedure, demonstrated the presence of acid-fast bacilli in 76 specimens. The number of positive specimens detected by microscopy was 82 on polycarbonate membrane filter concentrates, with an 80.2% sensitivity; 53 on centrifugate smears, with a 62.2% sensitivity; and 44 on direct smears, with a 55.8% sensitivity. Acid-fast microscopy results demonstrated that the sensitivity of the polycarbonate membrane filter sputum concentration method was superior to that of the recommended centrifuge concentration method and that the former method may be considered a rapid alternative when culture for acid-fast bacilli is impractical.
Serotypes of Cryptococcus neoformans strains isolated in Germany
Authors: Mishra S K , Staib F , Folkens U , Fromtling R A
Published: January 2020

An examination of 21 strains of Cryptococcus neoformans isolated from environmental and clinical sources in Germany revealed only serotypes A, D, and AD. Of these, 13 isolates were serotype A, 5 isolates were serotype D, and 3 isolates were identified as serotype AD. The absence of serotypes B or C confirms earlier reports from other European countries.
Cellular fatty acids of Brucella canis and Brucella suis
Authors: Dees S B , Hollis D G , Weaver R E , Moss C W
Published: January 2020

The cellular fatty acid composition of Brucella canis and Brucella suis was determined by gas-liquid chromatography. The presence of relatively large amounts of a 19-carbon cyclopropane fatty acid in B. suis was a major distinguishing feature between these organisms. The gas-liquid chromatography test for cellular fatty acids provides an additional criterion for the distinction of antigenically rough strains of B. suis which cannot be differentiated from B. canis by conventional procedures.
Simple, Inexpensive, and Rapid Way to Produce
Bacillus subtilis
Spores for the Guthrie Bioassay
Authors: Franklin Martha L. , Clark William A.
Published: January 2020

Esculin agar has been found to be a simple, inexpensive, rapid, and reliable means to promote production of spores of inhibitor-sensitive clones of
Bacillus subtilis
strains ATCC 6051 and 6633 for use in the Guthrie bioassay screening tests for genetic metabolic disorders.
Ethylenediaminetetraacetic acid (disodium salt)-labile bovine immunoglobulin M Fc binding to Brucella abortus: a cause of nonspecific agglutination
Authors: Nielsen K , Stilwell K , Stemshorn B , Duncan R
Published: January 2020

It was demonstrated by a radioimmunoassay procedure that Brucella abortus agglutinins from noninfected cattle sera, absorbed to B. abortus antigen and eluted with ethylenediaminetetraacetic acid (EDTA), was immunoglobulin M that bound to that bacterium by its Fc portion. The EDTA-eluted immunoglobulin M agglutinated intact B. abortus cells but not erythrocytes treated with B. abortus lipopolysaccharide. The specificity of the EDTA-eluted immunoglobulin was for B. abortus, although a small titer to Yersinia enterocolitica serotype O:9 was observed. In contrast, immunoglobulin M purified from the serum of a cow injected 7 days previously with heat-killed B. abortus bound to the antigen by its Fab portion, was not labile to EDTA treatment, cross-reacted extensively with Y. enterocolitica serotype O:9, and agglutinated various other bacterial antigens and normal erythrocytes.
Neisseria gonorrhoeae strains inhibited by vancomycin in selective media and correlation with auxotype
Authors: Mirrett S , Reller L B , Knapp J S
Published: January 2020

Strains of Neisseria gonorrhoeae that failed to grow on Thayer-Martin (T-M) and Martin-Lewis (M-L) media accounted for 2.0% of isolates at the University of Colorado Hospital and its Venereal Disease Clinic. A total of 31 inhibited and 31 control strains were compared by agar dilution testing for their susceptibilities to 13 antimicrobial agents used for treatment or in selective media. All 62 isolates were resistant to lincomycin, colistin, nystatin, amphotericin B, trimethoprim lactate, polymyxin B, and anisomycin. Vancomycin was the inhibitory antibiotic for N. gonorrhoeae in both T-M and M-L media. The vancomycin-inhibited strains were also significantly more sensitive to penicillin and ampicillin than were the control strains (P less than 0.001). The presence of the other antibiotics in selective media did not affect the minimum inhibitory concentrations of vancomycin for gonococci. All 31 inhibited strains were sensitive to 8.0 micrograms of vancomycin per ml, and 26 of these were sensitive to 2.0 microgram/ml. Decreasing the size of inoculum of gonococci results in greater inhibition by any given concentration of vancomycin. The vancomycin-sensitive strains contained significantly more arginine- hypoxanthine-, and uracil-requiring auxotypes (28 out of 31) than did the control strains (9 out of 31). As with T-M medium, some strains of gonococci will be missed when M-L medium with 4.0 micrograms of vancomycin per ml is the only medium used for the diagnosis of gonorrhea. This may be of particular importance in the confirmation of disseminated infection with Arg- Hyx- Ura- auxotypes of N. gonorrhoeae when cultures of blood, joint fluid, or skin lesions are negative.
Delayed development of antibody to hepatitis B surface antigen after symptomatic infection with hepatitis B virus
Authors: McMahon B J , Bender T R , Berquist K R , Schreeder M T , Harpster A P
Published: January 2020

During a 2-year period, 38 patients with clinical hepatitis B virus infection were seen at the Public Health Service Alaska Native Hospital in Bethel. This hospital serves an area in southwest Alaska that is hyperendemic for hepatitis B virus. The patients came to the hospital at various times from 15 scattered villages, and 92% were Eskimo. None of the patients had a recent history of hypodermic injection or blood transfusions. Twenty-five patients, all originally positive for hepatitis B surface antigen (HBsAg), were followed for up to 5 years after onset of illness, and 15 were either slow to develop, or never developed, antibody to HBsAg (anti-HBs), although only one patient became a chronic carrier of HBsAg. Six patients had a prolonged "window phase" between the disappearance of HBsAg and the appearance of anti-HBs which lasted for more than 1 year. Three patients had only transient anti-HBs after HBsAg disappeared, and five never developed measurable anti-HBs at all. All patients had antibody to hepatitis B core when both HBsAg and anti-HBs were absent. In contrast to studies in other populations, only 42% had anti-HBs 1 year after onset of illness, 63% had it at 18 months, 70% had it at 2 years, and 80% had it at 5 years. Factors related to ethnicity might account for the differences in the development of anti-HBs after acute symptomatic hepatitis B virus infection seen in Eskimos when compared with whites.
Evaluation of the solid-phase radioimmunoassay for diagnosis of St. Louis encephalitis infection in humans
Authors: Wolff K L , Muth D J , Hudson B W , Trent D W
Published: January 2020

Since the use of highly purified viral proteins in the solid-phase radioimmunoassay (SPRIA) procedure is not practical for routine diagnostic serology, the procedure was adapted for use with the crude antigens now commonly used to diagnose St. Louis encephalitis (SLE) virus infections. SLE and various other alpha- and flavivirus antigens were tested by both the SPRIA procedure and conventional serological methods. Standards were established for use of the crude antigens in the SPRIA procedure. Reproducibility of the procedure was similar to that of conventional tests. The SPRIA procedure specifically differentiated SLE from clinically similar alphaviruses, but did not differentiate SLE from related flaviviruses very well. SPRIA diagnosis of SLE infections by the immunoglobulin G response in paired sera was good. Generally, the crude antigen SPRIA procedure was as sensitive as the conventional serological tests, but not as specific.
Rapid differentiation of rocky mountain spotted fever from chickenpox, measles, and enterovirus infections and bacterial meningitis by frequency-pulsed electron capture gas-liquid chromatographic analysis of sera
Authors: Brooks J B , McDade J E , Alley C C
Published: January 2020

Normal sera and sera from patients with Rocky Mountain spotted fever, chickenpox, enterovirus infections, measles, and Neisseria meningitidis infections were extracted with organic solvents under acidic and basic conditions and then derivatized with trichloroethanol or heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives of organic acids, alcohols, and amines. The derivatives were analyzed by frequency-pulsed electron capture gas-liquid chromatography (FPEC-GLC). There were unique differences in the FPEC-GLC profiles of sera obtained from patients with these respective diseases. With Rocky Mountain spotted fever patients, typical profiles were detected as early as 1 day after onset of disease and before antibody could be detected in the serum. Rapid diagnosis of Rocky Mountain spotted fever by FPEC-GLC could permit early and effective therapy, thus preventing many deaths from this disease.
Enzyme-linked immunosorbent assay for detection of antibody to the hepatitis B surface antigen-associated delta antigen
Authors: Crivelli O , Rizzetto M , Lavarini C , Smedile A , Gerin J L
Published: January 2020

A blocking enzyme-linked immunosorbent assay (ELISA) was developed for specific detection of antibody to the hepatitis B surface antigen-associated delta antigen. The sensitivity of ELISA was intermediate between that of previously described immunofluorescence and radioimmunological assays for anti-delta. Performance of ELISA was simple and required only ordinary and inexpensive laboratory equipment.
Fluorescent treponemal antibody-absorption double-staining procedure
Authors: Hunter E F , Pender B J , Kennedy E J , Pettit D E , Schubert C M , Feeley J C , Larsen S A , McGrew B E
Published: January 2020

The fluorescent treponemal antibody-absorption double-staining step-by-step procedure and proposed reference reagents for the test are described. The test and reagents were evaluated in two separate laboratories on 265 fresh sera, and test results were compared with the reference fluorescent treponemal antibody-absorption test results performed in a third laboratory. The data indicate that the tests are comparable in the areas where the test is recommended for use. Problems with inadequate light filtration occurred, but these could be resolved. This test is recommended for use with microscopes equipped with incident illumination.
Rate of arabinitol production by pathogenic yeast species
Authors: Bernard E M , Christiansen K J , Tsang S F , Kiehn T E , Armstrong D
Published: January 2020

D-Arabinitol is a five-carbon polyol that is produced by many fungi. Detection of the metabolite has been reported in serum from patients with invasive candidiasis. We studied the production and assimilation of arabinitol by 46 clinical isolates of yeast species. Cultures of isolates of Candida albicans (9 strains), Candida tropicalis (12 strains), Candida parapsilosis (13 strains), Candida krusei (4 strains), Candida pseudotropicalis (3 strains), Torulopsis glabrata (3 strains), and Cryptococcus neoformans (2 strains) were assayed by gas-liquid chromatography. Yeast cells were cultured at 34 degrees C in yeast nitrogen base with 3.0 g of glucose per liter. At 1.5- to 3-h intervals, cells were counted and glucose and arabinitol were measured in media filtrates. The levels of arabinitol in cultures with 7.5 X 10(6) yeast cells per ml were compared. The mean concentrations of the metabolite in C. albicans, C. tropicalis, C. parapsilosis, and C. pseudotropicalis cultures wee 14.1, 1.6, 8.4, and 5.5 micrograms/ml, respectively. No arabinitol was detected in cultures of C. krusei, T. glabrata, or C. neoformans.
Immunization of inbred guinea pigs with varicella-zoster virus grown in a syngeneic transformed embryo cell line
Authors: Grose C
Published: January 2020

Varicella-zoster virus was serially propagated in a chemically transformed and cloned line of embryo cells (designated "104 C1") derived from the inbred strain 2 guinea pig. When strain 2 guinea pigs were immunized with varicella-zoster virus subcultivated in the syngeneic cell line, they produced high-titer virus-specific antiserum which lacked antibody against cellular determinants. This immunization procedure offers both practical and theoretical advantages over prior methods which involved inoculation of outbred laboratory animals with varicella-zoster virus grown in allogeneic or xenogeneic cell cultures.
Simplified coagglutination test for serological grouping of beta-hemolytic streptococci
Authors: Engel H W , van Silfhout A
Published: January 2020

A new coagglutination kit consisting of a plastic slide with dried antibody-coated staphylococci was evaluated for the grouping of beta-hemolytic streptococci of groups A, B, C, and G. The test was compared with the classical precipitation test, using hot formamide antigen extracts with 224 strains of groups A, B, C, and G streptococci. An agreement of 100% was found between the new coagglutination and the classical precipitation procedures. No false-positive results were obtained with group F and D streptococci; however, group L streptococci reacted with the group A reagent. The test procedure could be shortened by using suspensions of colonies from overnight cultures on blood agar plates in small volumes of Todd-Hewitt broth without further incubation. All 74 strains of groups A, B, C, and G were correctly identified from suspensions in Todd-Hewitt broth; however, suspending the colonies in 0.9% saline or phosphate-buffered saline resulted in lower sensitivities.
Detection of Salmonella infections by polyvalent enzyme-linked immunosorbent assay
Authors: Lentsch R H , Batema R P , Wagner J E
Published: January 2020

Serum immunoglobulin G (IgG) and IgM were measured for individual Salmonella species by the enzyme-linked immunosorbent assay (ELISA). F344 rats were experimentally infected with Salmonella typhimurium (serogroup B), S. enteritidis (serogroup D), and S. rubislaw (serogroup G.) Endotoxin extracted from each serogroup served as the antigen in a classical indirect ELISA. Antibody specific for each Salmonella serogroup was detected by ELISA. Normal gut flora from control animals appeared not to cause cross-reactions in the ELISA. Specificity and sensitivity of the IgG ELISA were determined by statistically evaluating false-positives and false-negatives. Ideal values of 90% or better were achieved in nearly all instances. Each antigen was also tested with heterologous antisera in an effort to develop a polyvalent assay for Salmonella species. No single antigen detected all positive heterologous antisera. Therefore, a polyvalent antigen composed of the three serogroup antigens was tested. The results suggested that Salmonella infections can be detected by measuring serum IgG levels with a polyvalent ELISA 6 to 9 days postinfection.
Rapid identification by the Micro-ID system of Enterobacteriaceae detected by urine screening
Authors: Kelly M T , Hale D C , Matsen J M
Published: January 2020

Previous studies have demonstrated that organisms detected by urine screening can be processed for rapid identification and antimicrobial susceptibility testing directly from urine or urine screening broth. In the present study, an improved method for processing such specimens was evaluated. Organisms were harvested by centrifugation from positive urine screening broth, and inocula were prepared for rapid identification by the Micro-ID system and rapid susceptibility testing by the Autobac system. Nearly 2,500 urine specimens were analyzed by urine screening, and 206 specimens had significant growth of gram-negative, oxidase-negative bacilli. These organisms, prepared by the centrifugation procedure, were identified and tested for susceptibility to antimicrobial agents. For comparison, identifications by the Micro-ID system and antimicrobial susceptibility tests by the Autobac system were performed on the same organisms the next day with inocula prepared from colonies growing from standard urine cultures. The results demonstrated that 95% of the organisms were correctly identified by this procedure, and susceptibility testing by the rapid method gave results in 94% agreement with the standard method. These results demonstrate that organisms detected by urine screening can be accurately identified and tested for antimicrobial susceptibility after centrifugation from urine screening broth. This system provides a practical procedure or same-day reporting of urine culture results.
Serotyping Cryptococcus neoformans by immunofluorescence
Authors: Kaplan W , Bragg S L , Crane S , Ahearn D G
Published: January 2020

Four serotypes of Cryptococcus neoformans designated A, B, C, and D are currently recognized. Although an agglutination test is most often used to serotype C. neoformans in cultures, this test is not appropriate for typing the fungus in fixed tissues. A study to prepare fluorescent-antibody reagents for typing C. neoformans in cultures and to determine whether they can be used to type this fungus in fixed tissues was carried out. Antisera to one strain belonging to each of the four serotypes were prepared in rabbits by intravenous injection of whole Formalin-killed cryptococci. Each antiserum was labeled with fluorescein isothiocyanate and then adsorbed with cells of each of the heterologous serotypes. The adsorbed conjugates were then tested against six serotype A isolates and five isolates of each of the other three serotypes. Labeled serotype A or D antiserum adsorbed with either B or C cells stained the A and D, but not the B or C, isolates. Labeled serotype B antiserum adsorbed with A cells stained the B and C, but not the A or D, isolates. Labeled A antiserum absorbed with D cells differentiated A from D; labeled C antiserum absorbed with B cells differentiated C from B. Of the 21 test isolates, 17 could be serotyped in paraffin sections of tissues of experimentally infected mice.
Preliminary evaluation of the autoSCAN-3, an instrument for automated reading an interpretation of microdilution trays: identification of aerobic gram-negative bacilli
Authors: Ellner P D , Myers D A
Published: January 2020

The autoSCAN-3, an instrument for the automated reading and interpretation of Microscan microdilution trays, was evaluated for its ability to identify gram-negative bacilli. The results obtained by the visual reading of microdilution trays were compared with the results obtained with the machine. A total 387 clinical isolates of Enterobacteriaceae and nonfermenters were compared by both methods. In 369 instances (95%), the identification obtained by visual reading of the microdilution tray agreed with the identification obtained with the autoSCAN-3. In eight instances, the visual identification differed completely from that of the machine, and in nine cases, the machine was unable to provide an identification.
Isolation of species-specific protein antigens of Rickettsia typhi and Rickettsia prowazekii for immunodiagnosis and immunoprophylaxis
Authors: Dasch G A
Published: January 2020

A simple procedure for the selective isolation of the protective species-specific protein antigens (SPAs) of Rickettsia typhi and Rickettsia prowazekii was developed to permit use of the SPAs in the immunodiagnosis and immunoprophylaxis of typhus infections. Although the SPAs were readily extracted from lysozyme- or detergent-treated rickettsiae, as measured by rocket immunoelectrophoresis, other polypeptides were also present, as shown by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. In contrast, both water and seven buffers, each at a 10 mM concentration and pH 7.6, were nearly equally effective in the selective release of the SPAs from whole cells by extraction for 30 min at 45 degrees C. High-ionic-strength buffers and MgCl2 abolished this SPA release, thus suggesting that divalent cations were important in the binding of the SPAs to the cell envelope. The efficacy of the dilute buffer extraction procedure for isolation of large amounts of SPAs was tested by further characterization of the supernatants obtained by centrifugation (200,000 x g) of two successive tris-(hydroxymethyl)aminomethane-hydrochloride buffer (Tris) extracts. With this procedure, between 10 and 15 mg of SPA was obtained from 100 mg of purified rickettsiae. Although low-molecular-weight ribonucleic acid fragments were released into the Tris extracts in significant amounts, only the SPAs were detected, in significant quantities, as measured by polyacrylamide gel electrophoresis and rocket immunoelectrophoresis. The Tris extracts contained the same major and minor SPA polypeptides as those observed previously in SPA preparations obtained by extensive diethylaminoethyl-cellulose column chromatography, but the Tris SPAs were more satisfactory antigens in an enzyme-linked immunosorbent assay.
Influence of media on temperature-dependent motility test for Yersinia enterocolitica
Authors: D'Amato R F , Tomfohrde K M
Published: January 2020

The influence of six widely used media on the motility of 100 isolates of Yersinia enterocolitica grown at 25 and 37 degrees C was investigated. Seven isolates were motile at 25 and 37 degrees C in all media, and the presence of flagellated cells was demonstrated by a flagellum stain. Six isolates were nonmotile at both temperatures in all media, and no flagella were observed. Identification schemes for Y. enterocolitica should reflect these possibilities.
Effects of bathing on Pseudomonas and Klebsiella colonization in patients with spinal cord injuries
Authors: Gilmore D S , Aeilts G D , Alldis B A , Bruce S K , Jimenez E M , Schick D G , Morrow J W , Montgomerie J Z
Published: January 2020

This study of Pseudomonas aeruginosa and Klebsiella pneumoniae colonization in humans with spinal cord injuries who were using the external urinary collection system showed that meticulous bathing with the bar soap issued by the hospital did not eliminated colonization and was frequently associated with the shifting of these bacteria to adjacent sites on the body. Bacterial counts of the skin showed that bathing did reduce the numbers of P. aeruginosa and K. pneumoniae found on the skin surface and temporarily eliminated these bacteria from some sites. The persistence of these organisms for long periods, even when patients were meticulously bathed, indicates that P. aeruginosa and K. pneumoniae may become part of the resident flora in these patients.
Preparation of Sputum Smears for Acid-Fast Microscopy
Authors: Goldfogel Gary A. , Sewell David L.
Published: January 2020

A method is presented for the preparation of satisfactory smears for acid-fast microscopy that do not contain viable cells of
Mycobacterium tuberculosis.
The single radial immunodiffusion assay highlights small antigenic differences among influenza virus hemagglutinins
Authors: Rodda S J , Gallichio H A , Hampson A W
Published: January 2020

The results of single radial immunodiffusion assays of influenza virus hemagglutinin were found to be greatly altered by small antigenic differences between test and reference strains. When such differences were present, the precise specificity of the antiserum used had a critical effect on the measured hemagglutinin antigen content obtained.
Characteristics of human isolates of unidentified fluorescence pseudomonads capable of growth at 42 degrees C
Authors: Oberhofer T R
Published: January 2020

Five strains of an unidentified fluorescent Pseudomonas sp. which were capable of growth at 42 degrees C were isolated over a 3-year period and were examined and compared with chosen strains of Pseudomonas aeruginosa, P. fluorescens, and P. putida. The strains were examined in a range of biochemical and carbon substrate alkalinization tests. The outstanding properties of the unidentified fluorescent Pseudomonas sp. included monopolar arrangement of flagella, gelatin liquefaction, litmus milk peptonization, and growth on cetrimide and Salmonella-Shigella agars. All strains failed to produce pyocyanin, 2-ketogluconate, and nitrogen gas, failed to acidify mannitol and xylose, and failed to alkalinize acetamide and allantoin. Similarities to P. fluorescens and P. putida were reflected in their resistance to carbenicillin and susceptibility to kanamycin and tetracycline.
Preparation of polyvalent viral immunofluorescent intracellular antigens and use in human serosurveys
Authors: Johnson K M , Elliott L H , Heymann D L
Published: January 2020

A method is described for preparation of polyvalent antigens for use in rapid screening for immunofluorescent antibodies to Lassa, Marburg, and Ebola viruses. The technique uses mixtures of specifically infected Vero cells placed on Teflon-templated microscopy slides. It was found to be as sensitive as the use of monovalent antigens for detection and quantitation of antibodies to these highly hazardous human pathogens.
Determination of immunoglobulin M antibodies against hepatitis B core antigen and hepatitis A virus by reorienting sucrose gradient high-speed centrifugation for diagnosis of acute viral-hepatitis
Authors: Swenson P D , Escobar M R , Galen E A , Carithers R L
Published: January 2020

Immunoglobulin M (IgM) antibodies against hepatitis B core antigen (anti-HBc) and hepatitis A virus (anti-HAV) were determined in 41 cases of acute viral hepatitis. In sera positive for anti-HBc or anti-HAV, IgM was separated from IgG by reorienting sucrose gradient high-speed centrifugation, and the IgG- and IgM-containing serum fractions were tested for the presence of specific antibody by radioimmunoassay. At the onset of illness, 4 of the 41 cases were classified as hepatitis A, 31 were hepatitis B, and 6 were non-A, non-B hepatitis, based on the results of these tests and of assays for hepatitis B surface antigen and antibody and hepatitis B e antigen and antibody. Fourteen of these 41 patients (34%) required IgM anti-HBc or IgM anti-HAV testing or both for appropriate classification. IgM anti-HBc persisted for at least 7 weeks after onset but no longer than 17 weeks in all patients tested with transient hepatitis B surface antigen-positive acute hepatitis. IgM anti-HAV persisted up to but not longer than 62 days in the patients with hepatitis A. Therefore, IgM anti-HBc and IgM anti-HAV determinants are valuable tools for the differential diagnosis of acute A, B, and non-A, non-B hepatitis.