bluuebunny/crossref_metadata_2025 huggingface dataset:
Growth of coagulase-negative staphylococci on colistin-nalidixic acid agar and susceptibility to polymyxins
Authors: Fung J C , McKinley G , Tyburski M B , Berman M , Goldstein J
Published: January 2020

Colistin-nalidixic acid agar, although recently recommended as a replacement for blood agar for primary plating of urine specimens ( Fung et al., J. Clin. Microbiol. 16:632-636, 1982), has also been reported to suppress the growth of some strains of staphylococci that are susceptible to colistin (polymyxin E). The susceptibility of 11 species of staphylococci to polymyxins was determined, and the ability of these species to grow on colistin-nalidixic acid agar was examined. Although the MICs for most of the strains tested were 8 micrograms/ml or less, only a few coagulase-negative staphylococci grew on or were inhibited by colistin-nalidixic acid agar. This descrepancy was explained by the antagonistic effects that medium components, such as physiological concentrations of magnesium and calcium and 5% sheep blood, had on the activity of polymyxin. Colistin-nalidixic acid agar is still recommended for routine urine processing; however, the poor growth of 13% of the Staphylococcus saprophyticus strains tested suggests that blood agar should be included in the primary plating battery of urine specimens obtained from female outpatients.
Mucoid conversion by phages of Pseudomonas aeruginosa strains from patients with cystic fibrosis
Authors: Miller R V , Rubero V J
Published: January 2020

A total of 21 of 22 independent isolates of cystic fibrosis-associated Pseudomonas aeruginosa were found to be lysogenic for DNA-containing, complex capsid viruses. Several of the phages demonstrated the ability to select mucoid cells from populations of nonmucoid bacteria. Conversion to mucoid growth was more frequently achieved when phages were isolated from mucoid as opposed to nonmucoid cystic fibrosis-associated strains.
Collaborative evaluation of the UniScept quantitative antimicrobial susceptibility test
Authors: Isenberg H D , D'Amato R F , McKinley G A , Hochstein L , Sampson-Scherer J
Published: January 2020

UniScept (Analytab Products, Plainview, N.Y.) is a commercially prepared microdilution antimicrobial susceptibility system for the determination, in a single tray, of antimicrobial MICs for gram-negative and gram-positive bacteria and those isolated from urinary tract infections. The system showed excellent correlation with the reference microdilution approach for organisms from clinical specimens and with stock and reference cultures. Intra- and interlaboratory reproducibility was high.
Applications of restriction endonuclease fingerprinting of chromosomal DNA of Neisseria meningitidis
Authors: Bjorvatn B , Lund V , Kristiansen B E , Korsnes L , Spanne O , Lindqvist B
Published: January 2020

Restriction endonucleases are bacterial enzymes that cleave DNA at specific sites. The resulting DNA fragments may be separated electrophoretically in gel to form specific restriction patterns. In the present study, the restriction endonuclease method was successfully adapted to the analysis of the chromosomal DNA of Neisseria meningitidis. The endonucleases HindIII and EcoRI provided optimal restriction patterns of ca. 50 well-separated lines. The pattern of each bacterial isolate was characteristic, stable, and reproducible. Despite some general similarity, the restriction patterns of the closely related B15 meningococci were surprisingly heterogeneous.
Enzyme-linked immunosorbent assay for Escherichia coli heat-stable enterotoxin
Authors: Klipstein F A , Engert R F , Houghten R A , Rowe B
Published: January 2020

The sensitivity of an enzyme-linked immunosorbent assay (ELISA) to detect pure native Escherichia coli heat-stable toxin (ST) and to identify ST-producing strains among clinical isolates was determined. Two synthetically produced ST preparations were used to raise hyperimmune antisera in rabbits and goats: ST(S), which has the same antigenicity as native ST; and ST(C), which is 15-fold more immunogenic. These antisera were used in the double-sandwich technique as either crude double-species antisera or pure single-species antibody. The sensitivity of the assay was increased by using either a purer antibody preparation or the antiserum to the more potent immunogen; the assay in which pure antibody to ST(C) was used was 2,857-fold more sensitive in detecting ST than the assay in which crude antiserum to ST(S) was used. The minimum amount of ST detectable by the ST(C) ELISA was 140 pg/ml, which was an amount 285-fold smaller than that detectable by the suckling mouse assay. Among 50 human E. coli isolates examined by both the ST(C) ELISA and an ELISA for heat-labile toxin (LT), which had a sensitivity of 290 pg/ml for LT, the respective toxins were consistently identified in broth cultures of 10 LT+ and ST-, 15 LT+ and ST+, and 10 LT- and ST+ strains, and there were no false-positive responses. The ST(C) ELISA also detected ST in all of seven ST - producing E. coli strains tested of human origin, which had been shown elsewhere by DNA hybridization probes to have ST-coding genes of either human or porcine origin, and in all of three ST-producing E. coi strains tested of porcine origin. These results indicate that the sensitivity of the ST(C) ELISA is the same as that of previously described LT ELISAs. The concomitant use of both ST and LT ELISAs provides a rapid, simple, and sensitive method for identifying among clinical isolates enterotoxigenic strains of E. coli which produce either toxin.
Comparison of serum mannan, arabinitol, and mannose in experimental disseminated candidiasis
Authors: de Repentigny L , Kuykendall R J , Chandler F W , Broderson J R , Reiss E
Published: January 2020

Concentrations of arabinitol, mannose, and mannan in serum have independently been reported to be elevated in patients with invasive candidiasis. These three marker substances were compared in a rabbit model. Twelve rabbits, immunosuppressed with cortisone, were infected intravenously with Candida albicans 3181A. Six uninfected control animals also received cortisone, and four rabbits were neither infected nor immunosuppressed. Blood samples, drawn from 2 days before to 14 days after infection, were assayed for serum mannan by sandwich enzyme immunoassay, antibodies to mannan by indirect enzyme immunoassay, arabinitol and mannose by gas-liquid chromatography, and serum creatinine. Serum mannan, negative before infection, peaked in all infected animals 4 days after infection (mean, 18 ng/ml) and decreased thereafter. Significant increases (2 standard deviations greater than mean in normals) in arabinitol, the arabinitol/creatinine ratio, and mannose were found in 12, 8, and 12 of the infected rabbits, respectively, but also in all 6 uninfected animals receiving cortisone. Only serum mannan was specific in this immunosuppressed rabbit model.
Quantitation of enterovirus 70 antibody by microneutralization test and comparison with standard neutralization, hemagglutination inhibition, and complement fixation tests with different virus strains
Authors: Hierholzer J C , Bingham P G , Coombs R A , Stone Y O , Hatch M H
Published: January 2020

We describe here a microneutralization procedure for conveniently testing large numbers of specimens for antibodies to enterovirus 70. The test utilized human rhabdomyosarcoma cells and was read by staining with crystal violet after 4 days of incubation. The test compares well with other serological assays, being more sensitive than the standard tube neutralization test and the complement fixation test, but less sensitive than the hemagglutination inhibition test. However, the hemagglutination inhibition test required concentrated, partially purified virus as antigen, as did the complement fixation test, and was difficult to read, so that its greater sensitivity may not be of practical significance. By all four test procedures, a recent isolate of enterovirus 70 was a more sensitive antigen than the prototype strain, as shown by greater geometric mean titers in sera of patients from various epidemics.
Rapid diagnosis of herpes simplex virus infections by enzyme-linked immunosorbent assay
Authors: Land S A , Skurrie I J , Gilbert G L
Published: January 2020

A total of 457 clinical specimens were tested for the presence of herpes simplex virus (HSV) by isolation in cell culture and by enzyme-linked immunosorbent assay. HSV antigen was detected by enzyme-linked immunosorbent assay in 94% of the clinical specimens from which the virus was isolated. The detection rate was improved to 100% when specimens were either assayed within 24 h or stored frozen at a constant temperature (-20 degrees C) for up to 14 days. Type-specific HSV antigen was also detected in 6% of culture-negative specimens. The assay can be completed in 5 h or less, and commercially available immunoglobulins are used. Enzyme-linked immunosorbent assay is a rapid and sensitive method for the diagnosis of HSV infection and can be used to improve the management of pregnant women with a history of genital herpes and of neonates and others with serious HSV infection which may require specific antiviral therapy. It also offers an alternative to cell culture for routine diagnosis of HSV infections.
Reaction pattern of immunoglobulin M and G antibodies to echovirus 11 structural proteins
Authors: Reigel F , Burkhardt F , Schilt U
Published: January 2020

The immunoglobulin M and G specific immune response of humans to echovirus 11 proteins during an echovirus 11 outbreak was studied by the immunoblot technique. Whereas immunoglobulin G antibodies were directed most exclusively to the VP 1 protein, the immunoglobulin M antibodies were directed against VP 1, VP 2, and VP 3.
Simonsiella filaments isolated from erosive lesions of the human oral cavity
Authors: Carandina G , Bacchelli M , Virgili A , Strumia R
Published: January 2020

The morphology and cultural characteristics of bacteria of the Simonsiella genus isolated from erosions of oral mucosa are reported here. Direct microscopic examination of smeared oral swabs and the consequent selection of suitable culturing procedures and media are compulsory for recovering Simonsiella microorganisms from clinical specimens in routine work.
Indirect immunofluorescence staining of Chlamydia trachomatis inclusions in microculture plates with monoclonal antibodies
Authors: Zapata M , Chernesky M , Mahony J
Published: January 2020

Indirect immunofluorescence (IF) staining, using a monoclonal antibody, detected two- to fourfold more inclusions than did iodine staining. Of 274 clinical specimens, 53 (19.3%) were positive by IF on passage 1 as compared with 33 (12%) by iodine staining (P less than 0.005). IF-stained inclusions in McCoy cells in the bottom of microculture wells were readily viewed with a long-focal-length objective at a magnification of 250 X.
Six new leptospiral serovars isolated from wild animals in Peru
Authors: Liceras de Hidalgo J L , Sulzer K R
Published: January 2020

Six new serovars of Leptospira interrogans were isolated from opossums (Didelphis marsupialis and Philander opossum) trapped in the Peruvian jungle. The proposed names, type strain designation, and serogroup of the serovars, respectively, were: huallaga, strain M-7, Djasiman serogroup; luis, strain M-6, Tarassovi serogroup; machiguenga, strain MMD-3, Icterohaemorrhagiae serogroup; rioja, strain MR-12, Bataviae serogroup; rupa rupa, strain M-3, Sejroe serogroup; and tingomaria, strain M-13, Cynopteri serogroup.
Rapid dimethyl sulfoxide-modified acid-fast stain of Cryptosporidium oocysts in stool specimens
Authors: Bronsdon M A
Published: January 2020

A rapid dimethyl sulfoxide modification of an acid-fast technique was applied to direct fecal smears to monitor cryptosporidiosis in nonhuman primates. Brilliantly stained pink oocysts against a pale green background demonstrated well-preserved internal morphology and facilitated rapid, simple, noninvasive diagnosis without fluorescent or phase-contrast microscopy.
Superoxol and amylase inhibition tests for distinguishing gonococcal and nongonococcal cultures growing on selective media
Authors: Arko R J , Odugbemi T
Published: January 2020

Two inexpensive screening tests were evaluated singly and in tandem for distinguishing Neisseria gonorrhoeae from other oxidase-positive microorganisms growing on selective gonococcal media. In tests of 728 cultures, including 460 N. gonorrhoeae, 4 Neisseria lactamica, 257 Neisseria meningitidis, and 7 Branhamella catarrhalis, both Superoxol (30% H2O2; J. T. Baker Chemical Co., Phillipsburg, N.J.) and amylase inhibition tests were 100% sensitive (positive) for 20-h cultures of N. gonorrhoeae. Singly, the Superoxol test was 92.7% specific for N. gonorrhoeae, compared with a specificity of 82.3% for the amylase inhibition test. By using tandem screening tests to distinguish gonococci, we achieved an overall specificity of 98.6%. Group A meningococci were the primary source of error in the Superoxol test, with 97% (37 of 38) strains producing gonococcal like reactions for catalase. From 5 to 20% of N. meningitidis serogroups X, Y, Z, and Z' and nontypable strains, as well as about 50% of B. catarrhalis and N. lactamica strains, were also strong catalase producers.
Rapid detection of herpes simplex virus in clinical specimens by use of a capture biotin-streptavidin enzyme-linked immunosorbent assay
Authors: Nerurkar L S , Namba M , Brashears G , Jacob A J , Lee Y J , Sever J L
Published: January 2020

A sensitive enzyme-linked immunosorbent capture assay with biotin and streptavidin (capture B/SA ELISA) was developed to detect herpes simplex virus (HSV) antigen. Rabbit anti-HSV antibody (immunoglobulin G fraction) was coated on flat-bottom, irradiated, 96-well polystyrene microtiter plates and served to capture HSV antigen. Clinical specimens from patients with genital herpes were added. Biotin-linked rabbit anti-HSV immunoglobulin G was used as the second antibody. The antigen-antibody complex was detected with alkaline phosphatase-conjugated streptavidin, which linked to the biotin. With clinical specimens, the test had a sensitivity of 95.6% and a specificity of 91.4% when compared with the tissue culture method. The presence of HSV antigen in specimens devoid of infectivity was confirmed by blocking the reaction with unlabeled rabbit and human antibody to HSV. The level of antigen detected by the capture B/SA ELISA did not necessarily correlate with the infectivity titer of the specimens. HSV antigens could be detected by the capture B/SA ELISA when the virus infectivity was destroyed at 37 degrees C, by UV irradiation, or by Triton X-100 treatment, but not when hypochlorite treatment was used. Greater sensitivity was obtained when HSV-1- and HSV-2-specific antibody reagents were used simultaneously in each test. The capture B/SA ELISA provides a relatively rapid method (4.5 h) which is quite sensitive and specific when compared with other non-tissue culture, direct assay methods.
DNA relatedness among strains of Campylobacter jejuni and Campylobacter coli with divergent serogroup and hippurate reactions
Authors: Hébert G A , Edmonds P , Brenner D J
Published: January 2020

Eleven strains of Campylobacter from earlier fluorescent-antibody studies were examined by DNA hybridization to determine their species. Three of the strains hydrolyzed sodium hippurate, and eight did not. Four of the hippurate-negative strains were in Campylobacter jejuni serogroups, and the remaining strains were in both C. jejuni and Campylobacter coli serogroups. DNA relatedness to type strains of C. jejuni and C. coli indicated that all three of the hippurate-positive strains and two of the hippurate-negative strains were C. jejuni. The six remaining hippurate-negative strains were C. coli. Two of the hippurate-negative strains in C. jejuni serogroups were C. jejuni, and two were C. coli. Three of the strains in serogroups of both species were C. jejuni, and four were C. coli. These studies confirm that a few strains of C. jejuni are hippurate negative and show that identical or highly related antigens are found in C. coli and C. jejuni.
Rapid visual detection of microorganisms in blood culture
Authors: Sage B H , Neece V R
Published: January 2020

We describe a method and apparatus for rapid visual detection of microorganisms in blood cultures. In the 30-min procedure, a lysing reagent for the preferential digestion of blood cells and a concentration device which causes 1 ml of lysed specimen to pass through a portion (3 mm2) of a membrane filter (pore size, 0.6 micron) were used. After the material remaining on the filter was Gram stained, the filter was mounted and examined microscopically. The ability to detect microorganisms in blood cultures was determined by spiking seven common blood pathogens into blood cultures prepared from the blood of healthy volunteers. Microorganism concentration in the cultures ranged from 1 to 1,000/ml. All of 34 cultures with at least 100 CFU/ml were detected, 34 of 64 cultures with less than 100 CFU/ml were detected, and 41 of 42 negative controls were correctly reported as negative.
Simple and reliable enzyme-linked immunosorbent assay with monoclonal antibodies for detection of Escherichia coli heat-stable enterotoxins
Authors: Thompson M R , Brandwein H , LaBine-Racke M , Giannella R A
Published: January 2020

We have developed a sensitive and specific competitive enzyme-linked immunosorbent assay for Escherichia coli heat-stable enterotoxins consisting of methanol-soluble, suckling mouse active peptides with similar core sequences (STa) by using monoclonal antibodies prepared against STa purified from a human isolate. The assay can detect 3 to 20 pg of purified STa, depending on the monoclonal antibody used in the assay. The assay is rapid, requiring ca. 1 h to complete. With this competitive enzyme-linked immunosorbent assay, we measured STa production by enterotoxigenic E. coli directly in Casamino Acid-yeast extract culture supernatants. The assay was suitable for measuring STa in culture supernatants from human, bovine, and porcine E. coli isolates. No cross-reactivity was observed with heat-labile enterotoxin, cholera toxin, or heat-stable enterotoxin STb, which is a methanol-insoluble peptide(s) active in the ligated pig jejunal loop test. A 100% correlation of toxin production was found by comparing the enzyme-linked immunosorbent assay with the previously established radioimmunoassay for STa and with suckling mouse activity.
Differentiation of the major flagellar antigens of Pseudomonas aeruginosa by the slide coagglutination technique
Authors: Ansorg R A , Knoche M E , Spies A F , Kraus C J
Published: January 2020

Antisera against the two major flagellar antigens of Pseudomonas aeruginosa were obtained by immunization of rabbits with isolated flagella and absorption of contaminating antisomatic antibodies. In the conventional slide agglutination test, the pure H antisera did not agglutinate the flagellated cells of the homologous strains. The addition of protein A-bearing staphylococci to H antiserum and homologous flagellated cells, the so-called slide coagglutination, results in a rapid development of flaky clumps. H coagglutination tests of reference strains, which formerly have been H typed by long-term tube agglutination and by the indirect fluorescent-antibody technique, yielded exactly the same subdivision of the strains in H type a and H type b as the more laborious and time-consuming methods. O grouping and H typing of 181 isolates from clinical specimens revealed a free combination of the somatic and flagellar antigens. 25 OH serovars were found. The simple and rapid coagglutination technique can promote the serovar determination of P. aeruginosa, particularly for the purpose of hospital infection control.
Detection of cytomegalovirus antibody with two commercially available assays, an indirect hemagglutination test and an enzyme immunosorbent assay
Authors: Cheeseman S H , Doern G V , Ferriani R A , Keville M W , McGraw B R , Stewart J A
Published: January 2020

By the use of two reference procedures, an indirect hemagglutination assay and a complement fixation test, the presence or absence of cytomegalovirus (CMV) antibody was determined for 221 human sera. Ninety-nine sera (44.8%) were found to contain CMV antibody. The remaining 122 sera (55.2%) lacked detectable CMV antibody. These same sera were then analyzed by two recently introduced, commercially available CMV antibody assays, an indirect hemagglutination test (IHA-c; Cetus Corp., Emeryville, Calif.) and an enzyme-linked immunosorbent assay (ELISA; M. A. Bioproducts, Walkersville, Md.). With the results of the reference procedures as true evidence of the presence or absence of CMV antibody, the sensitivity of the IHA-c was found to be 100%; the specificity was 98.4%. The sensitivity of the ELISA was also 100%; the specificity was 96.7%. The overall accuracies of these procedures were 99.1 and 98.2%, respectively. Time and motion studies revealed the IHA-c procedure to be faster and technically less demanding than the ELISA procedure.
Virus-specific immunoglobulin G subclasses in herpes simplex and varicella-zoster virus infections
Authors: Sundqvist V A , Linde A , Wahren B
Published: January 2020

The subclass specificities of antiviral immunoglobulin G (IgG) produced in response to herpes simplex and varicella-zoster virus infections were investigated. IgG1 and IgG3 with anti-herpes simplex virus activity were seen in patients with primary and reactivated disease, as well as in healthy seropositive subjects and in immunoglobulin preparations. IgG4 was occasionally seen alone or together with IgG1 and IgG3 in patients. In varicella, IgG3-specific antiviral antibodies were predominant, whereas in zoster, IgG1 was the dominant subclass.
Comparison of fluorescence polarization immunoassay and bioassay of vancomycin
Authors: Pohlod D J , Saravolatz L D , Somerville M M
Published: January 2020

Human serum samples were analyzed for vancomycin concentrations by two different methods: the fluorescence polarization immunoassay and the disk plate bioassay. Each assay method offered acceptable precision. The correlation between both assay methods was excellent (correlation coefficient = 0.985). Excluding technical time, the bioassay was the least expensive method to perform but was more labor intensive than the fluorescence polarization immunoassay.
Evaluation of rapid identification of gram-positive cocci in positive blood cultures by use of the AutoMicrobic system Gram-Positive Identification Card
Authors: Hamoudi A C , Marcon M J , Cannon H J
Published: January 2020

Because rapid identification of gram-positive organisms from blood cultures may provide valuable information for patient care and because the AutoMicrobic system Gram-Positive Identification (AMS-GPI) Card (Vitek Systems, Inc., Hazelwood, Mo.) is designed for the identification of these organisms in 4 to 13 h, we designed this study to evaluate the performance of the AMS-GPI Card in the direct identification of gram-positive organisms upon detection of growth in blood culture bottles. We compared direct identification by the AMS-GPI Card with the final AMS-GPI Card identification and with our standard identification methods. We evaluated 51 gram-positive organisms from clinical blood cultures as well as 49 simulated blood cultures. The isolates included Streptococcus pneumoniae (17), Streptococcus pyogenes (13), group D enterococci (12), Streptococcus agalactiae (11), viridans streptococci (10), coagulase-negative staphylococci (21), Staphylococcus aureus (15), and Listeria monocytogenes (1). The AMS-GPI Card identified all of the group D enterococci, viridans streptococci, and coagulase-negative staphylococci and all but one each of the Streptococcus pyogenes and Streptococcus agalactiae isolates. L. monocytogenes was also correctly identified. However, the AMS-GPI Card identified only 12 of 17 Streptococcus pneumoniae and 9 of 15 Staphylococcus aureus isolates by direct inoculation. We therefore conclude that the results of direct identification of gram-positive organisms by the AMS-GPI Card may be used cautiously for rapid direct identification of gram-positive organisms from positive blood cultures.
Vibrio vulnificus endometritis
Authors: Tison D L , Kelly M T
Published: January 2020

Vibrio vulnificus most frequently causes wound infections contracted after exposure to seawater or primary septicemias resulting from the consumption of raw oysters. We report a case of endometritis caused by V. vulnificus. The infection was apparently acquired during the act of sexual intercourse in seawater in an area in which V. vulnificus has been frequently isolated. The efficacy of treatment with an antimicrobial regimen which included tetracycline is discussed.
Enhancement of Chlamydia trachomatis infectious progeny by cultivation of HeLa 229 cells treated with DEAE-dextran and cycloheximide
Authors: Sabet S F , Simmons J , Caldwell H D
Published: January 2020

The effects of DEAE-dextran and cycloheximide on the infection of HeLa 229 cells with Chlamydia trachomatis serotype G were studied in terms of the number of cells infected and the yield of infectious progeny per infected cell. Pretreatment of the host cells with DEAE-dextran resulted in an increase in the number of infected cels but had no significant effect on the yield of infectious progeny per infected cell (burst size). In contrast, the addition of cycloheximide to the medium of infected cells had no significant effect on the number of infected cells but greatly enhanced the burst size. The burst size was calculated to be close to 500. The enhanced burst size was also observed in cells treated with DEAE-dextran and cycloheximide. In addition, there was an increase in the number of cells infected and an augmentation of the infectious progeny yield. Under the conditions of combined treatment, the yield of C. trachomatis serotype G cultivated in HeLa 229 cells was found to be approximately threefold higher than the yield of the organisms cultivated in McCoy cells. The results suggest that HeLa 229 cells treated with DEAE-dextran and cycloheximide offer a most suitable system for the high-yield cultivation of C. trachomatis organisms and possibly also for the diagnosis of infection with these organisms.
Identification of Staphylococcus species of bovine origin with the DMS Staph-Trac system
Authors: Langlois B E , Harmon R J , Akers K
Published: January 2020

The DMS Staph-Trac system was evaluated as a means for identifying the species of bovine strains of staphylococci routinely isolated from quarter-milk samples. The species identity of 83 of 91 (91.2%) isolates of staphylococci was correctly determined by this method. One isolate could not be identified by this system. The Staph-Trac system was able to distinguish between Staphylococcus hyicus and Staphylococcus epidermidis. We obtained a higher percentage of correct identifications with the DMS Staph-Trac system (91.2%) than we did in a previous study with the API Staph-Ident system (45.1%), using the same isolates (Langlois et al., J. Clin. Microbiol. 18:1212-1219, 1983).
Comparative evaluation of three commercial products and counterimmunoelectrophoresis for the detection of antigens in cerebrospinal fluid
Authors: Tilton R C , Dias F , Ryan R W
Published: January 2020

Three commercial products and counterimmunoelectrophoresis were evaluated for their ability to detect microbial antigens of Neisseria meningitidis, Haemophilus influenzae, and Streptococcus pneumoniae in cerebrospinal fluid from 157 patients suspected of having meningitis. Thirty-four patients were diagnosed as having bacterial meningitis by culture, microscopy, or antigen detection. The overall results showed the following detection percentages; counterimmunoelectrophoresis, 76%; Phadebact CSF, 76%; Directigen, 82%, and Bactigen, 93%. The results with purified antigen revealed that latex agglutination was more sensitive than coagglutination, which in turn was more sensitive than counterimmunoelectrophoresis.
Detection of Neisseria meningitidis group A, Haemophilus influenzae type b, and Streptococcus pneumoniae antigens in cerebrospinal fluid specimens by antigen capture enzyme-linked immunosorbent assays
Authors: Sippel J E , Prato C M , Girgis N I , Edwards E A
Published: January 2020

Antigen capture enzyme-linked immunosorbent assay was compared to coagglutination and counterimmunoelectrophoresis for the detection of meningococcal, Haemophilus, and pneumococcal antigens. Enzyme-linked immunosorbent assay detected 1 ng of purified meningococcal and Haemophilus polysaccharides per ml and 5 ng of pneumococcal polysaccharide per ml; coagglutination detected 20, 25, and 30 ng/ml, respectively, of these polysaccharides; and counterimmunoelectrophoresis detected 10, 50, and 60 ng/ml. Double-antibody sandwich-antiglobulin enzyme-linked immunosorbent assays, which employed antibodies produced in two animal species, differentiated 100% of the cerebrospinal fluid (CSF) specimens from meningococcal meningitis patients and 95% of the CSFs from Haemophilus patients from heterologous control CSFs. Double-antibody sandwich procedures, which use the same antiserum preparation for coating the wells of microtiter plates and for alkaline phosphatase-conjugated immunoglobulin, differentiated meningococcal CSFs from control specimens but were unable to effectively differentiate the Haemophilus or pneumococcal specimens from control CSFs. Coagglutination detected specific antigen in 92% of the meningococcal CSFs, 80% of the Haemophilus CSFs, and 92% of the pneumococcal specimens. The comparable percentages for counterimmunoelectrophoresis were 76, 95, and 71%.
Application of the peroxidase-antiperoxidase immunoassay to the identification of Salmonellae from pure culture and animal tissue
Authors: McRill C M , Kramer T T , Griffith R W
Published: January 2020

The peroxidase-antiperoxidase immunoassay was developed by using selected Salmonella serotypes to evaluate its potential for use in diagnostic bacteriology. S. choleraesuis var, kunzendorf, S. dublin, and S. typhimurium were the test organisms. Strong specific staining with corresponding antiserum was achieved with smears of each Salmonella serotype on microscope slides from formalinized cell suspensions, live broth cultures of clinical isolates, and tissue suspensions from the livers and spleens of experimentally infected mice. In addition, S. choleraesuis var. kunzendorf was detected in Formalin-fixed and fresh frozen tissues from experimentally infected pigs. The results of this study indicate that the peroxidase-antiperoxidase assay is well-suited for the rapid identification of Salmonella from pure cultures and that the technique can be useful in research for the detection of this pathogen in histological sections.
Evaluation of a two-hour method for screening pathogens from stool specimens
Authors: Greene L C , Appelbaum P C , Kellogg J A
Published: January 2020

The 2-h stool-screening test (SST) (API System S.A., Montalieu-Vercieu, France) was used to screen 231 organisms yielding suspicious colonies on stool differential agars for potential pathogens. All 54 salmonellae yielded correct screens. Of 14 shigellas, 9 keyed as possible Shigella spp.-Yersinia enterocolitica-rare Salmonella spp. (SYS), and 5 (all Shigella sonnei) keyed as possible S. sonnei-Y. enterocolitica-Arizona spp. (SYA). Three Arizona strains were identified as probable Salmonella spp., two were identified as SYA, and one was identified as SYS. Seven Y. enterocolitica strains keyed as SYS, and two keyed as SYA; one strain was screened out as a nonpathogen. The two Aeromonas hydrophila strains keyed as SYA, and the two Plesiomonas shigelloides strains keyed as SYS. All 63 Proteus, Morganella, Providencia, and Pseudomonas aeruginosa strains were screened out as nonpathogens. Among 80 coliforms, 37 were screened as SYA, 32 were screened as SYS, and 11 were screened as nonpathogens. On the basis of the SST, 69/80 coliforms would have been tested further. However, only 1/88 potential pathogens would have been missed, and all Proteus, Morganella, Providencia, and P. aeruginosa strains would have been excluded. The capability of the SST (when combined with a rapid identification method) of providing same-day identification of potential stool pathogens must be weighed against its inability to effectively screen out coliforms. The cost of this method is equivalent to that of a three-tube conventional screening method. The suitability of the SST for individual laboratories must be predicated on the incidence of stool pathogens and commensals in the specific setting as well as on factors related to work flow, technologist acceptability, and turnaround time.
Failure of the disk diffusion test to detect tobramycin resistance in kanamycin-resistant Escherichia coli strains
Authors: Santanam P
Published: January 2020

Approximately 40% of Escherichia coli strains isolated from clinical specimens at the Institute of Medical Microbiology of the University of Zurich were resistant to kanamycin but susceptible to tobramycin in disk diffusion tests. Whereas 50% of these strains required a MIC of 7 micrograms of tobramycin per ml to inhibit 1 x 10(5) to 4 x 10(5) cells, 20% of them required a concentration of 8 micrograms or more of the drug per ml. The disk diffusion test, therefore, failed to detect resistance to tobramycin in kanamycin-resistant E. coli strains. Cell extracts from two representative strains phosphorylated and inactivated kanamycin, amikacin, gentamicin, tobramycin, 3',4'-dideoxykanamycin B (dibekacin), butirosin, lividomycin,and ribostamycin, which together constituted a novel spectrum of substrates for the enzymatic activity.
Identification of Escherichia coli K1 antigen
Authors: Cross A , Orskov I , Orskov F , Sadoff J , Gemski P
Published: January 2020

We compared the use of bacteriophage sensitivity, seroagglutination with polyclonal antisera raised in rabbits or horses, seroagglutination with murine monoclonal antibody, and the serum agar precipitin technique for the detection of K1 capsular polysaccharide among clinical isolates of Escherichia coli obtained from blood stream infections. Some E. coli isolates failed to yield agreement among these tests, indicating that reliable detection of K1 antigen may require the use of multiple tests.
Recovery of Staphylococcus aureus from multiple body sites in menstruating women
Authors: Lansdell L W , Taplin D , Aldrich T E
Published: January 2020

Because we suspected the number of women harboring Staphylococcus aureus perivaginally to be higher than previously reported, we undertook an examination of normal, healthy volunteers. Of 97 young women, 26% yielded S. aureus from the external labia at the time of menstruation. Toxin associated with toxic shock syndrome was recovered from 5 of 25 subjects with positive genital cultures. Approximately one-half of the women with positive genital cultures yielded positive cultures from the posterior cervical fornix. These 12 women with positive vaginal cultures formed a distinct subgroup that was characterized by positive labial and tampon cultures, higher incidence of previous streptococcal infections, and more frequent vaginal insertion of their own fingers or those of a partner. Tampons were used by all but one woman in the group with positive labial cultures and all but one woman in the group with positive vaginal cultures. We concluded that the presence of S. aureus in the vagina involves mechanisms other than the use of tampons. Insertion of fingers and perhaps some aspect of immunological status appear to play a role.
Economical, simple method for production of the gaseous environment required for cultivation of Campylobacter jejuni
Authors: Pennie R A , Zunino J N , Rose C E , Guerrant R L
Published: January 2020

Campylobacter jejuni is an enteric pathogen recognized worldwide as a cause of diarrhea. Its isolation from stool samples requires a microaerophilic environment that heretofore has been expensive and cumbersome to create. An economical, portable, and simple method is described which involves the production of appropriate concentrations of oxygen and carbon dioxide. Inside a plastic bag are placed two cups, one containing fine steel wool (grade 0) previously soaked in a 2.5% aqueous solution of copper sulfate and the other containing an Alka-Seltzer tablet in tap water. As suggested by Jurgensen et al. (Rev. Bras. Pat. Clin. 18:58-63, 1982), we used the effervescent antacid to generate CO2. By plate counts, we found this method to be as reliable in the cultivation of 20 isolates of C. jejuni in pure and mixed fecal culture as the reference gas method (85% N2, 10% CO2, and 5% O2). Analyses of the gas mixture inside the bag after up to 24 h of incubation confirmed the creation of an atmosphere of reduced O2 and increased CO2 concentrations. This method is eminently suitable for field situations in which more costly supplies are not available.
Comparison of enzyme-linked immunosorbent assay, DNA hybridization, hemagglutination, and electron microscopy for detection of canine parvovirus infections
Authors: Teramoto Y A , Mildbrand M M , Carlson J , Collins J K , Winston S
Published: January 2020

Canine fecal samples were analyzed by enzyme-linked immunosorbent assays (ELISA) by using monoclonal antibodies to the canine parvovirus hemagglutinating protein. These data were compared with results obtained with DNA hybridization assays, hemagglutination assays, and electron microscopy. The highest correlation was observed between the ELISA and the hemagglutination tests, with 94.4% of samples showing agreement. Lower correlation was obtained between ELISA and DNA hybridization tests (73.3%). Correlation between ELISA and electron microscopy was 60.9%. The studies indicated that the ELISA can be used as a sensitive and specific diagnostic assay for canine parvovirus infections.
Detection of Semliki Forest virus in cell culture by use of an enzyme immunoassay with peroxidase-labeled monoclonal antibodies specific for glycoproteins E1 and E2
Authors: van Tiel F H , Boere W A , Vinjé J , Harmsen T , Benaissa-Trouw B J , Kraaijeveld C A , Snippe H
Published: January 2020

Four noncompeting monoclonal antibodies (MA) directed against either the E1 (UM 8.64 and 8.139) or E2 (UM 8.55 and 8.73) glycoprotein of Semliki Forest virus were purified and labeled with horseradish peroxidase. Each enzyme-labeled MA was tested alone and in combination with others for its sensitivity to detect virus-infected cells. Semliki Forest virus-infected L cells seeded as monolayers in 96-well plates were screened for the virus after incubation with enzyme-labeled MA and a substrate. In this system single enzyme-labeled MA even at high dilution (10(3.0) to 10(4.5] were able to detect virus-infected cells. The sensitivity of the test could be enhanced by combining two noncompeting MA (10(4.5) to 10(5.0]. Combinations of three and four MA were less effective, due to high absorbance values for noninfected cells. The threshold of virus defection was between 10(5) and 10(6) PFU/ml. This test is sensitive and specific and therefore may be useful for diagnostic purposes.
Correlation of bioluminescent assay of gentamicin in serum with agar diffusion assay, latex agglutination inhibition card test, enzyme immunoassay, and fluorescence immunoassay
Authors: Nilsson L
Published: January 2020

An improved bioluminescent assay of gentamicin in serum, based on the dose-dependent effect of the agent on the accumulation of extracellular ATP in Escherichia coli LU 14 cultures, is presented. The accuracy of the bioluminescent assay of gentamicin, expressed as the mean coefficient of variation over the therapeutic range, was 2.8%. Corresponding figures for an agar diffusion assay, a latex agglutination inhibition card test, an enzyme immunoassay, and a fluorescence immunoassay were 6.4, 17.5, 4.2, and 9.4%, respectively. All of the methods correlated well (r = 0.926 to 0.976), with the possible exception of the card test (r = 0.777 to 0.841). The bioluminescent assay requires only 1 microliter of serum, which allows for capillary sampling, and results are available within 75 min.
Clinical evaluation of the sensitivity and specificity of a commercially available enzyme immunoassay for detection of rubella virus-specific immunoglobulin M
Authors: Chernesky M A , Wyman L , Mahony J B , Castriciano S , Unger J T , Safford J W , Metzel P S
Published: January 2020

A solid-phase capture antigen enzyme immunoassay (Rubazyme-M) was evaluated for sensitivity and specificity on sera from 1,200 blood donors, 51 patients with rubella, 2 infants with congenital rubella, 104 patients with other infections, and 126 patients with immunological abnormalities. The sensitivity was 100% for sera tested between days 3 and 40 after the onset of symptoms of rubella virus infection. Rubella virus-specific immunoglobulin M was detected at birth in sera from congenitally infected infants and persisted for several months. Positive Rubazyme-M responses were observed in some patients in the absence of rubella diagnosis (one blood donor, three other infections, and two immunological abnormalities), providing a test specificity of 99.6%. None of 67 patients with rubella virus-specific immunoglobulin G antibody and high levels of rheumatoid factor were positive in the test.
Detection of enterovirus 70 with monoclonal antibodies
Authors: Anderson L J , Hatch M H , Flemister M R , Marchetti G E
Published: January 2020

To improve the ability to identify enterovirus-70 (EV-70) from patients with acute hemorrhagic conjunctivitis, we developed four monoclonal antibodies (MAbs) to EV-70. We reacted the four MAbs against nine previously characterized strains of EV-70 and heterologous viruses by virus neutralization, indirect immunofluorescence, and enzyme-linked immunosorbent assay (ELISA). Two of the MAbs neutralized all nine strains of EV-70 and none of the other enterovirus types tested. Two of the MAbs gave a positive reaction with all nine strains by indirect immunofluorescence, and three reacted with all nine strains by ELISA. None of the MAbs gave a positive reaction with heterologous viruses, including those associated with eye disease, by indirect immunofluorescence or ELISA. The two neutralizing MAbs failed to give a positive reaction with some of the strains of EV-70 by indirect immunofluorescence and ELISA, yet they neutralized these viruses. By ELISA with a polyclonal serum as capture antibody and a mixture of MAbs as detector antibody, we were able to detect from 10(2.2) to 10(5.8) 50% tissue culture infective doses of virus and to type lyophilized isolates of EV-70 sent from Taiwan from which we could not recover infectious virus. By choosing the appropriate MAb, or mixture of MAbs, we could construct a test which had the type specificity and strain sensitivity needed to type isolates of EV-70.
Interlaboratory comparison of the toluidine red unheated serum test antigen preparation
Authors: Parham C E , Pettit D E , Larsen S A , Hambie E A , Perryman M W , McGrew B E
Published: January 2020

The toluidine red unheated serum test (TRUST) antigen, a macroscopic flocculation test antigen developed by Pettit et al. (J. Clin. Microbiol. 18:1141-1145, 1983) by modifying the color-coded antigen of Kasatiya and Lambert (Appl. Microbiol. 28:317-318, 1974), was compared with the Venereal Disease Research Laboratory (VDRL) slide and rapid plasma reagin (RPR) 18-mm circle card tests for sensitivity, specificity, and reproducibility. Two lots of TRUST antigen were prepared by two laboratories in the Centers for Disease Control. Both laboratories performed the TRUST and VDRL slide test on serum samples from 1,102 patients attending the DeKalb County, Georgia, Sexually Transmitted Disease Clinic. In addition, one laboratory performed the RPR card test. Reactive sera were quantitated in the three nontreponemal tests and confirmed with the fluorescent treponemal antibody absorption test. The sensitivity in untreated syphilis for all nontreponemal tests involved was 98.4%. The specificity for these tests was 98.6%. The qualitative reproducibility among the four lots of TRUST antigen, VDRL slide, and RPR card tests was 98.2%. Only 20 sera showed discrepant results. Intralaboratory reproducibility of the two TRUST antigens was 100% for one laboratory and 99.6% for the other. Interlaboratory reproducibility for the four lots of TRUST and the VDRL slide test was 99%. Quantitative agreement +/- 1 dilution between the TRUST and RPR card test was 92.3%, and quantitative agreement +/- 1 dilution for the TRUST and RPR card test versus the VDRL slide test averaged 50%. The TRUST appeared to be comparable to the RPR card test in all parameters compared.
Variation in the abilities of automated, commercial, and reference methods to detect methicillin-resistant (heteroresistant) Staphylococcus aureus
Authors: Hansen S L , Freedy P K
Published: January 2020

The abilities of commercial MIC, automated, and reference methods for in vitro detection of methicillin-resistant Staphylococcus aureus were determined on 49 strains from eight hospitals. Micro-Media, MicroScan, Sensititre, Sceptor, API Uniscept KB, Abbott MS-2, Vitek AMS, Autobac MTS, NCCLS disk diffusion, and broth microdilution antimicrobial susceptibility testing procedures were evaluated. All testing was performed by using manufacturers' or reference procedures, and results were determined at no later than 24 h of incubation at 35 degrees C. With NCCLS disk diffusion, all strains were resistant to oxacillin (1 microgram), 47 (96%) were resistant to methicillin (4 micrograms), and 48 (98%) were resistant to nafcillin (1 microgram). The percentages of strains resistant to methicillin (greater than 8 micrograms/ml) were 98% with API Uniscept KB, 86% with Sceptor, MicroScan, and Autobac MTS, 84% with Sensititre, 71% with Micro-Media, and 70% with NCCLS MIC. Abbott MS-2 detected 86% of strains resistant to methicillin (greater than 5 micrograms/ml). With oxacillin (greater than 2 micrograms/ml), 90% were detected with Vitek AMS and 70% were detected with NCCLS MIC. With nafcillin (greater than 2 micrograms), 82% were resistant with Micro-Media, 57% were resistant by NCCLS MIC, and 50% (three of six) were resistant by MicroScan. Two strains from one hospital and one strain from another gave susceptible results with all automated and commercial methods. All strains from three centers were detected by all methods. Variability also occurred among the systems with cephalothin, clindamycin, gentamicin, chloramphenicol, and trimethoprim sulfamethoxazole.
Evaluation of the Quantum II and Rapid E identification systems
Authors: Murray P R , Gauthier A , Niles A
Published: January 2020

A total of 492 clinical isolates from the family Enterobacteriaceae were tested in the API 20E, Rapid E, and Quantum II identification systems. Discrepant identifications among these three systems were resolved by repeat testing in the identification systems or use of conventional biochemical tests. Of these isolates, 94.1% were correctly identified with the API 20E and Rapid E systems, and 97.0% were correctly identified with the Quantum II system. An additional 48 non-Enterobacteriaceae isolates were tested with the Quantum II system, and 83.3% were correctly identified. The majority of incorrect identifications with the Rapid E and Quantum II systems were caused by a single aberrant biochemical reaction. Reproducibility of the biochemical reactions obtained with these two systems was evaluated by testing 40 organisms in triplicate. Identical biocodes for all three tests were obtained for 10 organisms with the Quantum II system and for 19 organisms with the Rapid E system. Reproducibility of the Quantum II test results was improved with a subsequent modification of the photometer of this system. Both the Rapid E and Quantum II systems were inexpensive and were technically easy to inoculate and interpret.