bluuebunny/crossref_metadata_2025 huggingface dataset:
Hemadsorption immunosorbent technique for the detection of dengue immunoglobulin M antibody
Authors: Gunasegaran K , Lim T W , Ahmed A , Aaskov J G , Lam S K , Pang T
Published: January 2020

We developed a highly specific, sensitive, and economical hemadsorption immunosorbent technique for the detection of dengue-specific immunoglobulin M (IgM) antibody. The technique is based on the reaction of human sera with anti-human IgM immobilized onto a solid phase followed by the detection of dengue-specific IgM by the addition of a known quantity of dengue virus hemagglutinin and goose erythrocytes. Dengue-specific IgM-positive sera showed hemadsorption. IgM antibody specific for dengue virus was detected in 22 of 39 (56%) convalescent-phase sera from primary dengue infections and 8 of 10 (80%) convalescent-phase sera from secondary dengue infections. Additionally, 32 of 76 single sera from patients were positive for dengue IgM; these sera were previously uninterpretable by the hemagglutination inhibition test, as only a single serum specimen was available. No false-positive results were obtained with sera that were negative by the hemagglutination inhibition test for dengue virus. Crude dengue virus hemagglutinin preparations could be used without purification. Dengue-specific IgG did not interfere with the results, nor was there any cross-reactivity between dengue hemagglutinins and IgM specific for other viruses. Some cross-reactivity of the dengue-specific IgM was observed with Japanese encephalitis virus hemagglutinins, but this did not present any problems in the interpretation of results. This test is specific, inexpensive, highly reproducible, and simple to perform.
Simultaneous infections with different enteric and respiratory tract viruses
Authors: Brandt C D , Kim H W , Rodriguez W J , Arrobio J O , Jeffries B C , Parrott R H
Published: January 2020

Infants and young children with rotavirus (RV) or visualized adenovirus in their stools were tested for the simultaneous presence of a respiratory viral pathogen in their upper respiratory tract. Overall, at least 10.7% of 484 study subjects had such dual infections, including 8.3% of 385 RV-positive gastroenteritis patients and 24.3% of 37 RV-positive respiratory disease patients. Respiratory syncytial virus was present in 34.1% of 41 dual infections with RV and at least 40% of the 12 to 15 dual infections with visualized fecal adenovirus. Other pathogens found in the respiratory tract of patients with RV or visualized fecal adenovirus infections included influenza viruses, adenoviruses, parainfluenza viruses, rhinoviruses, and a cytomegalovirus.
Isolation of highly encapsulated Cryptococcus neoformans serotype B from a patient in New York City
Authors: Bottone E J , Kirschner P A , Salkin I F
Published: January 2020

For the first time, Cryptococcus neoformans serotype B was isolated from a patient in New York City, not a region endemic for B/C serotypes. The isolate was morphologically unusual, with cells several times larger in infected tissue than those characteristic of the yeastlike pathogen. This anomaly may be a problem in the identification of similar isolates. Two serotype differentiation media and a slide agglutination test were used for definitive serotype identification.
Method for the typing of Clostridium difficile based on polyacrylamide gel electrophoresis of [35S]methionine-labeled proteins
Authors: Tabaqchali S , O'Farrell S , Holland D , Silman R
Published: January 2020

A typing method for Clostridium difficile based on the incorporation of [35S]methionine into cellular proteins, their separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and their visualization by autoradiography is described. On analysis of the radiolabeled-protein profiles, nine distinct groups were observed (A to E and W to Z). The method, which is simple, reproducible, and readily expandable, has been applied in epidemiological studies to demonstrate cross-infection and hospital acquisition of C. difficile.
Separation of Cryptosporidium species oocysts from feces by using a percoll discontinuous density gradient
Authors: Waldman E , Tzipori S , Forsyth J R
Published: January 2020

Cryptosporidium oocysts were concentrated by an ether-phosphate-buffered saline sedimentation technique and then separated by density gradient centrifugation. This two-step method yielded highly concentrated oocysts largely free of bacteria and fecal debris.
Involvement of coagulase-negative staphylococci in toxic shock syndrome
Authors: Crass B A , Bergdoll M S
Published: January 2020

Coagulase-negative staphylococci that produce toxic shock syndrome toxin 1 (TSST-1) or a staphylococcal enterotoxin or both were isolated from various sources. Coagulase-negative strains that produce TSST-1 alone or with enterotoxin A were the only staphylococci isolated from seven patients with toxic shock syndrome. Two other toxic shock syndrome patients had coagulase-positive staphylococci also, but only the coagulase-negative strains produced TSST-1. Coagulase-positive and coagulase-negative strains that produced TSST-1 were isolated from two other toxic shock syndrome patients. In addition, coagulase-negative staphylococci that produced toxins were isolated from patients with other staphylococcal infections and from food implicated in a case of food poisoning.
New method of preparing elastase toxoid from Pseudomonas aeruginosa
Authors: Morihara K , Homma J Y
Published: January 2020

A new method for the preparation of elastase toxoid of Pseudomonas aeruginosa was developed. A chloroacetyl peptide derivative (CICH2CO-HOLeu-Ala-Gly-NH2; HOLeu, N-hydroxy-L-leucine), an active-site-directed irreversible inhibitor of Pseudomonas aeruginosa elastase, was used to prepare elastase toxoid with or without pretreatment with Formalin and L-lysine. Elastase toxoid thus obtained appeared to be ideal, possessing negligible enzyme activity while retaining full antigenicity and immunogenicity.
Development and persistence of local and systemic antibody responses in adults given live attenuated or inactivated influenza A virus vaccine
Authors: Clements M L , Murphy B R
Published: January 2020

An enzyme-linked immunosorbent assay was used to measure nasal-wash and serum isotype-specific hemagglutinin antibody responses in 109 seronegative (hemagglutination-inhibiting titer less than or equal to 1:8) adults vaccinated intranasally with live attenuated A/Washington/897/80 (H3N2) or A/California/10/78 (H1N1) cold-adapted (ca) virus or with licensed subvirion vaccine subcutaneously. Live and inactivated virus elicited serum immunoglobulin A (IgA) responses in 83 and 96% of vaccinees, respectively, and elicited serum IgG responses in 72 and 100% of vaccinees. Inactivated virus induced higher titers of serum antibodies than did live virus and stimulated a nasal-wash IgG response more often than did live virus (94 versus 59%, P less than 0.01). In contrast, only 38% of inactivated virus vaccinees had local IgA responses compared with 83% of live virus vaccinees. Serum IgA and IgG and nasal IgG antibody titers remained elevated above prevaccination levels for at least 6 months in most of the live and inactivated vaccine responders, but the mean level of local IgA antibody induced by infection with live virus vaccine, in particular, decreased substantially. Considered in the context of previous work, the finding that live virus vaccine induced relatively long-lasting antibody in both local and serum compartments suggested that this vaccine may be a suitable alternative to inactivated vaccine for use in healthy persons.
Resistance of adults to challenge with influenza A wild-type virus after receiving live or inactivated virus vaccine
Authors: Clements M L , Betts R F , Tierney E L , Murphy B R
Published: January 2020

The efficacy of live attenuated cold-adapted (ca) reassortant influenza A H3N2 and H1N1 virus vaccines against experimental challenge with homologous wild-type virus 7 months after vaccination was compared with that of licensed inactivated virus vaccine in 106 seronegative (hemagglutination-inhibiting antibody titer less than or equal to 1:8) college students. The live attenuated virus vaccines induced as much resistance against illness as did the inactivated vaccine. Vaccine efficacy, measured by reduction in febrile or systemic illness in vaccines, compared with that in controls was 100% for ca H3N2 vaccine, 84% for inactivated H3N2 vaccine, 79% for ca H1N1 vaccine, and 67% for inactivated H1N1 vaccine. Less protection was conferred against upper respiratory tract illness; there was 50 and 77% protection in ca and inactivated H3N2 vaccines, respectively, but there was no protection in ca or inactivated H1N1 vaccinees. The duration, but not the magnitude, of H1N1 wild-type virus shedding in both ca and inactivated vaccinees was significantly reduced compared with controls. In contrast, a significant reduction in the duration and magnitude of H3N2 virus shedding was observed in ca vaccinees but not in inactivated vaccines. After wild-type virus challenge, live ca virus vaccinees demonstrated resistance at least as great 7 months postvaccination as did inactivated virus vaccinees. These observations indicate that live virus vaccines may be a satisfactory alternative to inactivated vaccines for healthy persons.
Importance of exfoliatin toxin A production by Staphylococcus aureus strains isolated from clustered epidemics of neonatal pustulosis
Authors: Kaplan M H , Chmel H , Hsieh H C , Stephens A , Brinsko V
Published: January 2020

Clustered epidemics of pustulosis due to Staphylococcus aureus occurred in two geographically distant newborn nurseries. In nurseries A and B an attack rate of pustulosis of 0.8 and 2.0 cases per 100 live births occurred, respectively. Experimental phage type 1046/1116 belonging to phage group II dominated clustered epidemics in nursery A, while group II phage type 3A/3C/55/71 and 3A/3C/55 occurred in nursery B. Other group II strains also occasionally produced clustered epidemics. These epidemic strains were found to be making heat-stable dermal exfoliatin toxin A (ETA) which had a pI of 6.8 and a molecular weight of 32,000 and 33,000. ETA-bearing strains did not make bacteriocin. Children infected with ETA-producing strains developed extensive bullous pustulosis. Surveillance cultures of personnel revealed an ETA-bearing strain in only one person. This strain was not the same phage type as the epidemic cluster. In contrast, ETA-bearing epidemic strains were found in the inanimate environment of both nurseries. ETA protein acts as an important virulence factor in the production of neonatal pustulosis infection and appears to be linked with the ability of S. aureus organisms to stick to the inanimate environment.
Immunologic response of patients with legionellosis against major protein-containing antigens of Legionella pneumophila serogroup 1 as shown by immunoblot analysis
Authors: Sampson J S , Plikaytis B B , Wilkinson H W
Published: January 2020

Major protein-containing antigens of Legionella pneumophila serogroup 1 were were identified by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblot analysis with rabbit antisera to 14 different Legionella species or serogroups. Fourteen bands were observed in immunoelectropherograms of whole-cell, sonicated cell, and heated cell preparations, seven of which appeared in the supernatant fluid from the heated cells and three of which were shown in an outer membrane fraction. Immunoblots of whole-cell antigen preparations of 14 Legionella species or serogroups revealed seven major Legionella proteins: antigens with molecular weights of 58,000, 79,000, and 154,000 were present in all Legionella sp. strains, antigens with molecular weights of 44,000 and 97,000 occurred in multiple species, and antigens with molecular weights of 14,000 and 25,000 were present only in L. pneumophila strains. All sera from 15 patients with culture-confirmed L. pneumophila serogroup 1 disease and 14 of 18 (78%) sera from serologically diagnosed patients reacted with the 58-kilodalton (kDa) common antigen. In contrast, less than one-half of the sera reacted with the L. pneumophila-specific proteins (14 and 25 kDa). Absorption of sera with Escherichia coli cells had no effect on their reactivity with the 58-kDa antigen, whereas absorption with L. pneumophila serogroup 1 cells removed reactivity. These data suggest that the 58-kDa antigen may prove useful in serodiagnostic tests for legionellosis.
Quantitative estimation by a standardized enzyme-linked immunosorbent assay of human T-cell lymphotropic virus type I antibodies in adult T-cell leukemia and acquired immune deficiency syndrome
Authors: Halbert S P , Poiesz B , Friedman-Kien A E , Montagna R , Blattner W A , Anken M
Published: January 2020

Sera from patients with adult T-cell leukemia and asymptomatic carriers of human T-cell lymphotropic virus type I (HTLV-I) from widely separated areas of the world reacted strongly in a standardized quantitative enzyme-linked immunosorbent assay procedure with HTLV-I viral antigen prepared from a strain isolated in the United States. There was a sharp differentiation of the values seen in the patients as compared with a normal population. Of the 35 acquired immune deficiency syndrome patients with Kaposi's sarcoma, only 2 were positive for HTLV-I antibodies in this test, and the distribution of the negative assay values in the other acquired immune deficiency syndrome patient sera was similar to that seen in the normal sera. Sera which contained extremely high levels of antibodies to other unrelated viruses (rubella virus, cytomegalovirus, and herpes simplex virus) all showed negative anti-HTLV-I results, in a pattern similar to the normal sera. Sera from patients with several autoimmune disease (systemic lupus erythematosus, rheumatoid arthritis, thyroiditis) as well as those with infectious mononucleosis or myeloma all also showed the normal distribution of negative results, in spite of the presence of very high levels of the autoantibodies, etc., associated with their illnesses.
Bordetella bronchiseptica phase variation induced by crystal violet
Authors: Ishikawa H , Isayama Y
Published: January 2020

A method for effective induction of phase variation in Bordetella bronchiseptica by treatment with crystal violet (CV) is presented. When grown in CV-broth, phase I cells dissociated into three serial phases. Appearance of variant cells was observed simultaneously with the beginning of cell multiplication. The maximum effect of CV was obtained at a concentration of 8 micrograms/ml, when the proportion of variants in the population reached 100%. The main factors which affected phase variation were concentration of CV, culture age, and temperature of treatment. The phase variants obtained were phenotypically stable upon serial passages on Bordet-Gengou agar plates. By this treatment, no reversion of phase descendants to former phases was observed.
Characterization and evaluation of monoclonal antibodies developed for typing influenza A and influenza B viruses
Authors: Walls H H , Harmon M W , Slagle J J , Stocksdale C , Kendal A P
Published: January 2020

Monoclonal antibodies that are broadly reactive with influenza A or influenza B viruses were produced as stable reagents for typing influenza viruses. Monoclonal antibodies to influenza A were specific for either matrix protein or nucleoprotein. The antibodies to influenza B were specific for nucleoprotein or hemagglutinin protein. In an enzyme immunoassay procedure, influenza A antibodies detected H1N1, H2N2, and H3N2 influenza A virus strains collected between 1934 and 1984. Each of the influenza B antibodies detected influenza B reference viruses collected between 1940 and 1984. Pools of either influenza A or influenza B monoclonal antibodies were used to detect influenza viruses reisolated from clinical specimens in tissue culture. At 48 h after inoculation, the influenza A monoclonal antibodies detected 64% of H1N1 and 94% of H3N2 influenza A specimens, and the influenza B monoclonal antibodies detected 79% of the influenza B specimens. The results of this study suggest that the monoclonal antibodies described should provide useful diagnostic reagents for workers in virology laboratories who wish to isolate and identify influenza virus but have been unable to obtain consistent supplies of animal sera specific for influenza A or B viruses.
Chemical characterization of Flavobacterium odoratum, Flavobacterium breve, and Flavobacterium-like groups IIe, IIh, and IIf
Authors: Dees S B , Moss C W , Hollis D G , Weaver R E
Published: January 2020

The cellular fatty acid, sphingolipid, and isoprenoid quinone compositions of Flavobacterium odoratum, Flavobacterium breve, and Flavobacterium-like groups IIe, IIh, and IIf were determined, using thin-layer, gas-liquid, and reverse-phase high-performance liquid chromatography. The fatty acid data showed that groups IIe, IIh, and IIf were similar to recognized Flavobacterium species by the presence of relatively large amounts of iso-branched hydroxy and nonhydroxy acids. Groups IIe and IIh were essentially identical in fatty acid composition but were distinguished from group IIf, F. breve, and F. odoratum on the basis of minor qualitative and quantitative differences. All strains tested contained menaquinone 6 as the major isoprenoid quinone, and all lacked sphingolipids. Overall, the chemical data suggest that groups IIe, IIh, and IIf are additional Flavobacterium species and are different from sphingobacteria, which contain sphingolipid and menaquinone 7 as the major quinone.
Polypeptide specificity of the antibody response after primary and recurrent infection with bovine herpesvirus 1
Authors: van Drunen Littel-van den Hurk S , Babiuk L A
Published: January 2020

The polypeptide specificities and defense mechanisms of the humoral immune response to bovine herpesvirus 1 were analyzed. Sequential serum samples taken from cows which were experimentally infected with bovine herpesvirus 1 were tested for their reactivity with individual bovine herpesvirus 1 polypeptides by immunoprecipitation, immunoblotting, and enzyme-linked immunosorbent assay. All bovine immune sera reacted with each of the three major bovine herpesvirus 1 glycoproteins, GVP 6/11a/16, GVP 3/9, and GVP 11b, during primary as well as recurrent infection. Among these glycoproteins, GVP 6/11a/16 induced the earliest and most consistent immune response. The levels of antibody to GVP 3/9 and GVP 11b varied among the animals, and they were slightly lower than the level of antibody to GVP 6/11a/16. Antibodies to several nonglycosylated polypeptides and two additional glycoproteins were also detected with the immunoblot assay. However, these antibodies were usually apparent only during recurrent infection, whereas they were undetectable or low during primary infection. The antibodies in the sera from all animals mediated virus neutralization and destruction of virus-infected cells by two immune mechanisms, e.g., antibody- and complement-mediated lysis and antibody-dependent cell-mediated cytotoxicity.
Response of dairy calves to vaccinia viruses that express foreign genes
Authors: Gillespie J H , Geissinger C , Scott F W , Higgins W P , Holmes D F , Perkus M , Mercer S , Paoletti E
Published: January 2020

Repeated intradermal inoculations of calves with wild-type vaccinia virus and recombinant vaccinia viruses expressing human hepatitis B virus surface antigen and herpes simplex virus, type 1, glycoprotein D produced characteristic pox lesions at each site of injection. In some instances, calves were inoculated as many as five times at intervals from 4 to 7 weeks. The lesions invariably were more severe after the second inoculation. Subsequent inoculations produced a less severe area of redness, swelling, necrosis, and scab formation. No other signs of illness, such as an elevation in temperature, were noted in the calves. Vaccinia virus was isolated in low titers from scabs taken at various times after inoculation. No lesions were formed at the sites injected with tissue culture fluid and cellular debris at the same time that virus inoculations were made. Calf contact controls remained normal through the 8-week exposure in isolation units with calves inoculated twice with vaccinia virus. No neutralizing antibody to vaccinia virus was detected in the contact controls. In contrast, the virus-inoculated calves developed neutralizing antibody to vaccinia virus and to herpes simplex virus glycoprotein D in serum. In all cattle, a second inoculation significantly enhanced the neutralizing antibody response within 1 week, suggesting that an anamnestic response had occurred. No antibody to hepatitis B virus surface antigen was elicited in calves after repeated inoculations with vaccinia recombinants that express hepatitis B virus surface antigen and are known to elicit in rabbits antibodies reactive with hepatitis B virus surface antigen.
Indirect alkaline phosphatase immunoenzymatic staining for the detection of antibodies to Epstein-Barr virus-induced virus capsid antigens and early antigens
Authors: Musiani M , Zerbini M , Gentilomi G , La Placa M
Published: January 2020

An indirect alkaline phosphatase immunoenzymatic staining technique was developed for the detection of antibodies against Epstein-Barr virus-induced virus capsid antigens and early antigens in cell smears. The presence of antibodies against Epstein-Barr virus-induced virus capsid antigens and early antigens was revealed by a dark blue staining of cells expressing the antigens. The alkaline phosphatase assay gave a permanent record of the reaction that could be visualized under an ordinary light microscope. The titers obtained with this assay on 91 serum samples were significantly correlated with the titers obtained with an immunofluorescence technique.
DNA probes for identification of clinically important Bacteroides species
Authors: Kuritza A P , Getty C E , Shaughnessy P , Hesse R , Salyers A A
Published: January 2020

Conventional procedures for identifying gram-negative anaerobes such as Bacteroides spp. are cumbersome and time-consuming. A simpler approach would be to use DNA probes to identify these organisms. Since many different species of gram-negative anaerobes are isolated from clinical specimens, the most useful DNA probes would be probes that identify a few clinically significant groups of anaerobes. To obtain such probes, we cloned HindIII-digested chromosomal DNA from various Bacteroides species and then screened these probes, labeled with 32P by nick translation, for hybridization to DNA from various species of Bacteroides, Fusobacterium, and other gram-negative bacteria. We identified three DNA probes (pBFII-4, pBFII-5, and pBFII-6) that hybridized specifically to DNA from Bacteroides fragilis, the species that accounts for about half of all isolates from clinical specimens containing anaerobes. We identified one DNA probe (pBE-3) that hybridized to all members of the B. fragilis group, a group of species that resemble B. fragilis with respect to fermentation pattern and antibiotic resistances. We also identified one probe (pBO-21) that hybridized to DNA from all Bacteroides sp. strains as well as to DNA from strains of Fusobacterium necrophorum and Fusobacterium nucleatum. pBO-21, but not pBE-3, cross-hybridized with a cloned Bacteroides sp. 16S rRNA gene. The limit of detection for these probes was 10(6) bacteria. The probes could detect B. fragilis in blood culture medium and in mixed cultures with other gram-negative bacteria. Attempts to use biotin-labeled DNA probes instead of 32P-labeled probes were not successful because the Bacteroides sp. extracts contained material that bound the streptoavidin-peroxidase detection reagent.
Comparison of washed nasopharyngeal cells and whole nasal secretions for detection of respiratory syncytial virus antigens by enzyme-linked immunosorbent assay
Authors: Hendry R M , Pierik L T , McIntosh K
Published: January 2020

We compared washed nasal epithelial cells with unfractionated nasal secretions as sources of respiratory syncytial virus (RSV) antigens in an indirect enzyme-linked immunosorbent assay (ELISA). Of 28 infants positive for RSV by virus isolation or direct immunofluorescence or both, 27 (96%) were positive by ELISA with whole nasal secretions, whereas only 19 (68%) were positive by ELISA with the matching washed-cell fractions. Furthermore, the ELISA absorbances obtained with nasal secretions were significantly greater than those seen with washed-cell fractions, indicating that whole nasal secretions contain relatively greater amounts of RSV antigens as measured by ELISA.
Evaluation of streptomycin and ethambutol concentrations for susceptibility testing of Mycobacterium tuberculosis by radiometric and conventional procedures
Authors: Woodley C L
Published: January 2020

Clinical isolates of Mycobacterium tuberculosis were used to compare various concentrations of streptomycin and ethambutol in the BACTEC 460 (Johnston Laboratories, Inc., Towson, Md.) radiometric method for drug susceptibility testing with those in the conventional method. Streptomycin used at 2.0 micrograms/ml for both methods showed a 0.99 agreement with susceptible strains and a 0.97 agreement with resistant strains. Ethambutol used at 2.5 micrograms/ml for the radiometric method showed 1.00 agreement with both susceptible and resistant strains when compared with ethambutol at 5.0 micrograms/ml for the conventional method.
Use of 51Cr release to measure the cytotoxic effects of staphylococcal leukocidin and toxin neutralization on bovine leukocytes
Authors: Loeffler D A , Schat K A , Norcross N L
Published: January 2020

Leukocidin toxin from Staphylococcus aureus produces specific cytolytic effects on neutrophils and macrophages. The most commonly used method for determination of leukocidin activity is microscopic examination for characteristic morphological changes in toxin-treated cells. The 51Cr release assay was modified to allow quantitation of the cytolytic effects of leukocidin on bovine peripheral blood neutrophils and lymphocytes. Toxin neutralization by serum and milk samples was quantitated by this method. The neutralizing abilities of the various samples were found to correlate with the levels of immunoglobulin G (IgG1) specific for leukocidin. Undiluted normal serum samples, however, were capable of partially preventing the cytotoxic effects of leukocidin. The assay was shown to be an effective means of quantitating the cytotoxic activity of leukocidin on neutrophils as well as demonstrating neutralization of cytotoxicity by milk and serum samples.
Tentative interpretive criteria for in vitro antibacterial susceptibility testing with imipenem
Authors: Shungu D L , Cerami A T , Weinberg E , Capizzi T , Gadebusch H H
Published: January 2020

Imipenem is a member of a new class of highly potent beta-lactam antibiotics, carbapenems, with a very broad antibacterial spectrum. This study was undertaken to determine tentative interpretive criteria for in vitro susceptibility testing with 10-micrograms imipenem disks. A careful examination of the zone diameters and the corresponding MICs for 489 clinical isolates by regression-line analysis and the error rate-bounded classification scheme suggested the following guidelines: greater than or equal to 16 mm with an MIC correlate of less than or equal to 4 micrograms/ml for susceptible, 14 to 15 mm (8 micrograms/ml) for moderately susceptible, and less than or equal to 13 mm (greater than or equal to 16 micrograms/ml) for resistant. Lack of cross-resistance between imipenem and broad-spectrum cephalosporins such as cefotaxime and ceftazidime argues against their use as class disks to predict in vitro susceptibility of bacterial species to carbapenems.
Interspecies reactivity of five monoclonal antibodies to Mycobacterium tuberculosis as examined by immunoblotting and enzyme-linked immunosorbent assay
Authors: Andersen A B , Yuan Z L , Hasløv K , Vergmann B , Bennedsen J
Published: January 2020

Five different murine monoclonal antibodies (MAbs) to Mycobacterium tuberculosis were examined for degree of cross-reactivity with other mycobacterial species by enzyme-linked immunosorbent assay and immunoblotting. One MAb reacted solely with M. tuberculosis and M. bovis BCG. Two of the MAbs reacted with all mycobacterial species examined, whereas two MAbs demonstrated a limited reactivity pattern. The epitopes are located on molecules susceptible to protease treatment, and two of these molecules possess concanavalin A-binding moieties. Two of the antigens defined by these five MAbs are present in tuberculin purified protein derivative.
Comparison of the standard pour plate procedure and the ATP and Limulus amebocyte lysate procedures for the detection of microbial contamination in intravenous fluids
Authors: Anderson R L , Highsmith A K , Holland B W
Published: January 2020

The intrinsic and extrinsic microbial contamination of large-volume parenterals has been associated with bacteremias in hospitalized patients. When epidemiologic data suggest the association of contaminated intravenous (i.v.) fluids with disease, appropriate laboratory methods must be devised to analyze quickly the suspect fluid. A study was undertaken to compare three laboratory test methods (standard pour plate [SPP] technique, ATP procedure, and Limulus amebocyte lysate [LAL] assay) for detecting the presence of microorganisms in artificially contaminated i.v. fluid. SPP proved the most sensitive of the assay techniques used, but a 24-h period was required for microbial growth. The LAL assay appeared more sensitive in detecting i.v. contamination than the ATP method. These studies suggest that the LAL and ATP methods can be used for the rapid detection of microbial contamination in i.v. fluid. SPP and LAL procedures would have practical laboratory application when the contamination of i.v. fluids is suspected, and they are more sensitive in detecting microbial contamination in these solutions than the ATP method.
Three adenovirus type 8 genome types defined by restriction enzyme analysis: prototype stability in geographically separated populations
Authors: Kemp M C , Hierholzer J C
Published: January 2020

Adenovirus type 8 strains were collected over a 19-year period from eye specimens from patients with keratoconjunctivitis. These strains were divided by restriction enzyme analysis with the endonucleases SalI, HindIII, SacI, KpnI, and SmaI into three genotypic subgroups. The prototype strain (Trim) was found throughout the United States from 1966 through 1985 and also in Taiwan and Greece in the early 1980s. Genotype 8C was identified in an arc from Maryland to Missouri to Alabama from 1971 through 1974. Genotype 8D was found only in an epidemic of eye disease among Vietnamese refugees being resettled in northwest Florida in 1975. Genotypes 8C and D were distinct from genotypes 8A and B described from Japan in 1975 through 1981. Hemagglutination tests with a battery of avian and mammalian erythrocytes did not distinguish between the genotypic subgroups. Similarly, the genotypes could not be differentiated by hemagglutination inhibition or serum neutralization tests with reference prototype antisera. The long-term prevalence of the Trim strain suggests that adenovirus type 8 has greater genetic stability than the other adenovirus types studied to date.
Latex agglutination test for staphylococcal toxic shock syndrome toxin 1
Authors: Igarashi H , Fujikawa H , Shingaki M , Bergdoll M S
Published: January 2020

A reversed passive latex agglutination method, in which latex particles were sensitized with specific anti-toxic shock syndrome toxin-1 (TSST-1) immunoglobulin, was found to be a simple and sensitive method for the detection of TSST-1 production by Staphylococcus aureus strains. The minimum amount of TSST-1 detectable was approximately 1.0 ng/ml. Of 41 S. aureus isolates from toxic shock syndrome patients and controls, 23 were positive for TSST-1 production, whereas only 20 strains were positive for TSST-1 production by an Ouchterlony immunodiffusion method. The reversed passive latex agglutination method was used to examine S. aureus strains isolated in Japan from staphylococcal infections, feces from healthy individuals, food from poisoning outbreaks, and market food.
Reaction pattern of human anti-Mycoplasma pneumoniae antibodies in enzyme-linked immunosorbent assays and immunoblotting
Authors: Jacobs E , Bennewitz A , Bredt W
Published: January 2020

In serological diagnosis of Mycoplasma pneumoniae disease the frequently used complement fixation test is based on a cross-reacting glycolipid. Recently enzyme-linked immunoassays have been developed to overcome this lack of specificity. To study the involvement of the various proteins and the influence of age on the level of antiprotein antibodies present, we investigated by enzyme-linked immunoassays (immunoglobulin M [IgM] and IgG) and immunoblotting the sera of healthy persons of different age groups as well as sera of patients (including paired sera) with M. pneumoniae infection. In sera of children with nonrespiratory diseases and in healthy blood donors the IgM antibodies rose during the first 2 years of life to a relatively constant background level (optical density at 405 nm of 0.15 to 0.21). In contrast IgG remained low up to the seventh year and then increased to moderate levels (optical density of 0.15). The blotting patterns showed few IgM bands in the age group of 20 to 30 years. IgG blots revealed, up to 7 years, only very few reactions with a 168-kilodalton protein, but in higher age groups a considerable number of reactions with proteins of 193, 168, 84, 69, and 56 kilodaltons were detected. In the sera of patients, positive IgM blots were most numerous in the third week, whereas the number of IgG blots increased up to the fourth and the fifth week. At this time all sera contained antibodies against the 168-kilodalton protein, which is identical with the adhesin of M. pneumoniae. In a patient with acute infection, who had a high preinfection IgG level, no IgM response developed. The data indicate a relatively high background of antibodies against M. pneumoniae proteins in older age groups, suggesting a requirement for paired sera. Furthermore, reinfections of adults may occur without a concomitant IgM response.
Quantitative gas chromatographic analysis of volatile fatty acids in spent culture media and body fluids
Authors: van den Bogaard A E , Hazen M J , Van Boven C P
Published: January 2020

Gas chromatographic analysis of volatile fatty acids for identification of obligately anaerobic bacteria and for presumptive diagnosis of anaerobic infections is now widely practiced. However, it is difficult to compare data because only a qualitative analysis is done or only chromatograms are presented instead of quantitative data on volatile fatty acid production. We compared three stationary phases for volatile fatty acid analysis of aqueous solutions and four methods of pretreating samples for gas chromatography. Quantitative analysis could be done accurately by using Carbowax as the stationary phase after pretreatment of spent culture media with Dowex columns. If only qualitative analysis is required (e.g., for presumptive diagnosis of anaerobic infections), ether extraction and headspace analysis are equally suitable. The overall variation coefficient for volatile fatty acid production by four reference strains of obligately anaerobic bacteria after 24 h of incubation was approximately 10%.
Design and analysis considerations in evaluating the chemiluminescence response of mouse spleen cells
Authors: Giltinan D M , Capizzi T P , Abruzzo G K , Fromtling R A
Published: January 2020

Chemiluminescence is the result of the respiratory burst generated by phagocytic cells after stimulation by antigen. The measurement of chemiluminescence represents a sensitive means for detecting antigenic stimulation and immune cell function. Although the kinetics of chemiluminescence reactions have been described, appropriate statistical methods for the evaluation of data from chemiluminescence assays have not been reported. Based on examination of data from several studies in which the chemiluminescence response of spleen cells was investigated after stimulation with the particulate antigen zymosan, recommendations are made for the design and statistical evaluation of such studies. Three parameters were used in assessing the chemiluminescence response; peak intensity of the emitted light, time to peak, and the area under the intensity-time curve. The data indicated that peak intensity alone provides an adequate characterization of the chemiluminescence response. Since percent change in response upon treatment is of interest, analysis on the log scale is appropriate, and the statistical procedure of choice in evaluating data of this type is a trend analysis. The need for a balanced allocation of treatments to avoid potential bias is demonstrated. The methods proposed are illustrated with data from two studies in which the effect of preincubation with low concentrations of ketoconazole, an antifungal agent, on the chemiluminescence response of BALB/cBY spleen cells was examined.
Micro direct inoculation method for the isolation and identification of Chlamydia trachomatis
Authors: Yong D C , Paul N R
Published: January 2020

Current standard procedures for the isolation and identification of Chlamydia trachomatis are laborious. A more rapid method for the isolation and identification of C. trachomatis has been developed. This method features the use of a multiwell microplate to which trypsinized McCoy cells and specimens are added simultaneously, followed by centrifugation. A simplified one-step iodine-glycerol staining procedure is used to detect the chlamydial inclusions. The requirements of the conventional macro method for preseeding cell monolayers and for the use of cumbersome cover slips in glass vials are eliminated. Studies on 345 clinical specimens showed that the micro method is as sensitive as the conventional method but can be performed more conveniently, rapidly, and economically.
Enhancement of fluorescence development of end products by use of a fluorescence developer solution in a rapid and sensitive fluorescent spot test for specific detection of microbial beta-lactamases
Authors: Chen K C , Holmes K K
Published: January 2020

A fluorescent spot test method for specific detection of microbial beta-lactamases as previously published (K. C. S. Chen, J. S. Knapp, and K. K. Holmes, J. Clin. Microbiol. 19:818-825, 1984) was improved by the use of a fluorescence developer solution. The fluorescence developer solution used in this study consisted of 0.78 M sodium tartrate buffer containing 12% formaldehyde at a final pH of 4.5. An addition of 1 volume of fluorescence developer solution to 5 volumes of ampicillin or cephalex substrate solution incubated with beta-lactamase-producing organisms, followed by heating the mixture at 45 degrees C for 10 min resulted in enhancement of fluorescence of the end products of beta-lactamase activity. This provides a more sensitive assay for microbial beta-lactamases and offers the potential for direct detection of beta-lactamases in clinical specimens.
Production and utilization of pyochelin by clinical isolates of Pseudomonas cepacia
Authors: Sokol P A
Published: January 2020

Forty-three Pseudomonas cepacia isolates were screened for the production of pyochelin. Twenty-one (49%) produced pyochelin, and 22 (51%) were pyochelin negative. Of the 21 strains producing pyochelin, 18 were from patients with severe infections, 11 of which resulted in death. Of the 22 strains which did not produce pyochelin, 13 were from patients with mild or moderate infections. Pyochelin production by P. cepacia isolates infecting cystic fibrosis patients correlates with morbidity and mortality in these patients. Pyochelin was shown to stimulate the in vitro growth of P. cepacia in the presence of transferrin. P. cepacia isolates were able to accumulate 59Fe-pyochelin regardless of whether they produced this siderophore.
Elimination of nonspecific cytomegalovirus immunoglobulin M activities in the enzyme-linked immunosorbent assay by using anti-human immunoglobulin G
Authors: Joassin L , Reginster M
Published: January 2020

Direct enzyme-linked immunosorbent assay methods offer several advantages in assessing past or recent exposure to cytomegalovirus (CMV) infection, but there persist many pitfalls in the use of these methods for determining specific immunoglobulin M (IgM). The efficiency of absorption of sera by IgG-coated latex beads, aggregated human IgG, or Staphylococcus aureus, i.e., for removing nonspecific CMV IgM activities, was evaluated in comparison with the effect of an anti-human IgG hyperimmune serum. Large routine series comprising serum samples from patients of various clinical groups and healthy individuals were examined. The CMV IgM-positive samples were at first treated with latex or aggregated IgG, but these absorptions left too many CMV IgM-positive individuals. S. aureus increased the nonspecific activity of some sera and, in other cases, removed or impaired specific IgM activities. The anti-IgG treatment caused the disappearance of nonspecific CMV IgM activities that had resisted the other treatments, whereas specific activities remained intact. Utilizing this method, only 1.03% of the routine series patients remained CMV IgM positive by the enzyme-linked immunosorbent assay, a figure in good agreement with a mean probability of CMV antibody acquisition of 0.33% for the population living in Belgium. On the other hand, in a series of patients who were investigated for serological response to several viruses, eight individuals displayed multiple IgM activities after anti-IgG treatment. In these cases, most IgM activities were found in patients who had IgG toward the related antigen for a long time before transient IgM was detected. This result implies that to assess a diagnosis of primary infection, it is necessary to examine serial specimens for IgG acquisition accompanying specific IgM.
Effect of relative centrifugal force and centrifugation time on sedimentation of mycobacteria in clinical specimens
Authors: Ratnam S , March S B
Published: January 2020

Optimum relative centrifugal force (RCF) and centrifugation time to concentrate mycobacteria in clinical specimens were determined by processing split samples of sputa and urines containing mycobacteria with combinations of different RCFs and centrifugation times. Although individual test results showed considerable variation in the recovery rates of mycobacteria in the sediment, the data indicated that higher recovery rates occurred as centrifugation speed and time were increased. With a 15- to 20-min centrifugation time, on the average, 67 to 71% of mycobacteria were recovered at an RCF of 2,074 X g, and 76 to 80% were recovered at 3,005 or 3,895 X g at maximum radius. The remainder of mycobacteria was mostly recovered from the supernatant, but culturing of supernatant was not profitable. Increasing RCF had a negligible effect on acid-fast bacillus smear sensitivity. The smear sensitivity for about 25,000 clinical specimens processed with an RCF of 3,800 X g for 20 min was 71% compared with 69% as determined for over 30,000 specimens processed in a similar manner but an RCF of 2,000 X g. An RCF of 3,000 X g applied for 15 min, or an RCF of about 2,000 to 2,500 X g applied for 20 min, is considered adequate to concentrate mycobacteria in clinical specimens.
Two fatal cases of type E adult food-borne botulism with early symptoms and terminal neurologic signs
Authors: Badhey H , Cleri D J , D'Amato R F , Vernaleo J R , Veinni V , Tessler J , Wallman A A , Mastellone A J , Giuliani M , Hochstein L
Published: January 2020

Type E botulism, one of the least common forms of botulinal intoxication on the East Coast of the United States, is described for two elderly patients with chronic underlying disease. Both patients consumed tainted kapchunka, a salted, ungutted whitefish. Gastrointestinal symptoms and signs were prominent, but neurologic complaints, although noted soon after the consumption of the fish in one patient, did not progress until late in the course of the patient's illness. One patient exhibited both urinary retention, which was reported mainly in one outbreak of type E botulism (M.G. Koenig, A. Spickard, M.A. Cardella, and D.E. Rogers, Medicine [Baltimore] 43:517-545, 1964), and muscular fasciculations, which have been rarely reported.
Evaluation of the AutoMicrobic system Gram-Positive Susceptibility-MIC card for detection of oxacillin-resistant coagulase-negative staphylococci
Authors: Woolfrey B F , Lally R T , Ederer M N
Published: January 2020

A total of 398 consecutive clinical staphylococcus isolates, of which 205 were coagulase negative and 193 were coagulase positive, were tested in parallel by using AutoMicrobic system Gram-Positive Susceptibility-MIC cards and modified Mueller-Hinton agar containing 4% NaCl and oxacillin (6 micrograms/ml). The AutoMicrobic system cards correctly detected 103 of 104 (99%) oxacillin-resistant coagulase-negative isolates with no reports of false resistance.
Tentative disk diffusion susceptibility interpretive criteria for BMY-28142, a new cephalosporin
Authors: Fuchs P C , Jones R N , Barry A L , Thornsberry C
Published: January 2020

A total of 750 bacterial isolates, including 37 different species, were tested for susceptibility to BMY-28142 by standardized broth microdilution and disk diffusion tests. The zone diameter interpretive criteria tentatively suggested for the 30-micrograms BMY-28142 disk are as follows: susceptible = greater than or equal to 18 mm (MIC less than or equal to 8.0 micrograms/ml), resistant = less than or equal to 14 mm (MIC greater than or equal to 32 micrograms/ml), and indeterminate = 15 to 17 mm.
Comparison of a yellow latex reagent with other agglutination methods for the identification of Staphylococcus aureus
Authors: Brown W J
Published: January 2020

A new commercial yellow latex agglutination reagent (Bacto-Staph) was compared with the slide and tube coagulase tests and three other commercial reagents for the identification of 283 Staphylococcus aureus and 54 non-S. aureus staphylococcal strains. Test sensitivities for the identification of S. aureus were as follows: tube coagulase, 99.6%; slide coagulase, 98.6%; Bacto-Staph, 99.6%; Staphylatex, 98.6%; Sero STAT Staph, 98.2%; and Staphyloslide, 97.5%. No false-positive reactions were observed with any of the commercial reagents.
Molecular epidemiology of human rotavirus infection in children in Hong Kong
Authors: Tam J S , Kum W W , Lam B , Yeung C Y , Ng M H
Published: January 2020

Rotavirus was identified in 256 (28.5%) of 899 hospitalized children with diarrhea during a 12-month period in Hong Kong. Fourteen electropherotypes were identified, and the appearance of each occurred in a sequential manner during the study period. One patient was shown to be mixedly infected with two prevalent electropherotypes. Sequential stool specimens from another case showed the appearance of an extra RNA band during the course of the diarrheal episode.
Serodiagnosis of La Crosse virus infections in humans by detection of immunoglobulin M class antibodies
Authors: Calisher C H , Pretzman C I , Muth D J , Parsons M A , Peterson E D
Published: January 2020

Sera from 92 humans with illnesses clinically compatible with those caused by California serogroup virus infections were tested for antibody to La Crosse (LAC) virus by using the immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC ELISA), the IgG ELISA, and the hemagglutination inhibition (HI), complement fixation and serum dilution-plaque reduction neutralization tests. On the reported day of onset of illness in 18 individuals, 94% had IgM antibody, 50% had neutralization antibody, 33% had HI antibody, and 11% had IgG antibody. Neutralization, HI, and IgG antibody prevalence rates increased thereafter, whereas IgM antibody prevalence remained high (92% 2 or more weeks after the onset of illness). It was concluded that the MAC ELISA is a sensitive test for the presence of antibody to LAC virus. The sensitivity of the MAC ELISA and the rapidity with which it can be performed appear to provide a powerful tool for the clinically relevant serodiagnosis of LAC virus infections in humans.