bluuebunny/crossref_metadata_2025 huggingface dataset:
Culture of the surfaces of urinary catheters to sample urethral flora and study the effect of antimicrobial therapy
Authors: Kunin C M , Steele C
Published: January 2020

At the time indwelling urinary catheters were removed, the urethral flora was sampled by rolling the catheters onto culture plates. Cultures were obtained from 398 patients with sterile urine. Catheter surfaces were colonized less often in males than in females (16.8 and 67.0%, respectively) and yielded correspondingly fewer bacterial species per catheter. In both sexes, gram-positive species were isolated more frequently than gram-negative species (428 and 131 isolates, respectively). The bacteria most commonly isolated were Staphylococcus epidermidis and Streptococcus faecalis. Staphylococcus saprophyticus was not recovered despite the large proportion of young, sexually active women in the study population. Gram-negative bacteria, mainly Escherichia coli, gradually colonized the catheters over time but at all times were recovered in lower amounts the gram-positive organisms and less often in males than in females. Slime production by coagulase-negative staphylococci did not relate to the density of organisms recovered from the catheters or influence the presence of gram-negative bacteria. Despite frequent use of antibiotics in this population, the urethral flora remained highly susceptible to these drugs. Antibacterial activity was not detected on the catheters despite high concentrations in the urine. This suggests that systemic antibiotics have a very limited effect on resident urethral flora. Despite relatively small numbers in the urethra, gram-negative bacteria readily produce urinary tract infections in catheterized patients.
Rapid microbiochemical method for presumptive identification of gastroenteritis-associated members of the family Enterobacteriaceae
Authors: Yong D C , Thompson J S , Prytula A
Published: January 2020

A method for rapid screening of isolates of pathogenic members of the family Enterobacteriaceae is described. Flow charts are used in conjunction with triple sugar iron agar, o-nitrophenyl-beta-D-galactopyranoside-phenylalanine-motility sulfate screening media, oxidase test, and six rapid biochemical tests, namely, lysine decarboxylase, urease, indole, esculin hydrolysis, malonate, and xylose. This scheme is used to provide an inexpensive but rapid presumptive identification of Salmonella, Shigella, Edwardsiella, Aeromonas, Plesiomonas, Vibrio, and Yersinia isolates from stool cultures.
Evaluation of the BACTEC radiometric method for detection of 1% resistant populations of Mycobacterium tuberculosis
Authors: Tarrand J J , Gröschel D H
Published: January 2020

BACTEC and conventional methods of antimicrobial susceptibility testing were compared with the use of artificial mixtures of 1% resistant and 99% susceptible Mycobacterium tuberculosis strains. Inocula for the assays were prepared on the basis of radiometric readings. A total of 40 resistant strains were tested: 18 were resistant to isoniazid, 16 to rifampin, 5 to streptomycin, and 1 to ethambutol. The BACTEC method detected 27 of 39 strains at the greater than 0.5% resistance level, whereas the conventional plate method detected only 8 of 40. In addition, the results of the BACTEC assay were closer to the expected 1% resistance level (0.7%) than were the data obtained with the proportional plate method (0.3%; P = 0.001). This difference was most striking with the isoniazid-resistant strains. The precision of the assay methods was quite different (coefficients of variation, 26% for BACTEC and 54% for plates; P = 0.0002). Streptomycin-resistant strains had the highest variability in both assay methods. A 1-day delay in calculating the BACTEC data after the control vial reading was equal to or greater than 30 resulted in a 25% reduction in the calculated level of resistance (0.7 to 0.53). By adhering exactly to the recommended procedures for the BACTEC test method and by using log-phase inocula, this method shows better precision and accuracy at the 1% resistance level than does the proportional plate method.
Indications that the erythrocyte receptor involved in enterotoxigenic Escherichia coli attachment is a sialoglycoconjugate
Authors: Bartus H , Actor P , Snipes E , Sedlock D , Zajac I
Published: January 2020

A reverse hemagglutination assay was used to study adherence to human erythrocytes by Escherichia coli H10407, which possesses colonization factor antigen I. Pretreatment of erythrocytes with trypsin, chymotrypsin, papain, protease, and neuraminidase completely abolished attachment reactivity. In addition, the hemagglutination reaction was prevented by the presence of urea and guanidine. In contrast, the lipases, nucleotide hydrolases, exoglycosidases, and reagents affecting disulfide or sulfhydryl moieties did not alter receptor reactivity. Glycoconjugates containing sialic acid inhibited the hemagglutination reaction. Furthermore, a sialoglycoprotein isolated from the erythrocyte membrane inhibited the hemagglutination reaction. Collectively, these data indicate that the erythrocyte receptor responsible for attachment by E. coli possessing colonization factor antigen I is a sialoglycoconjugate.
Comparison of the Cathra Repliscan II, the AutoMicrobic system Gram-Negative General Susceptibility-Plus Card, and the Micro-Media System Fox Panel for dilution susceptibility testing of gram-negative bacilli
Authors: Reiber N E , Kelly M T , Latimer J M , Tison D L , Hysmith R M
Published: January 2020

A comparative evaluation was done to test the accuracy of the Cathra Repliscan II agar dilution system (Diagnostic Equipment, Inc., St. Paul, Minn.), the AutoMicrobic system with Gram-Negative General Susceptibility-Plus Card (Vitek Systems, Inc., Hazelwood, Mo.), and the Micro-Media Fox Panel micro broth dilution system (Micro-Media Systems, Inc., San Jose, Calif.) in determining MICs of 12 antibiotics for 200 gram-negative bacilli. Of the 200 strains tested, 12 isolates did not grow in one of the three systems. The 188 remaining organisms included 158 members of the family Enterobacteriaceae, 20 Pseudomonas spp., 5 Acinetobacter sp., 3 Aeromonas spp., and 2 Vibrio spp. A total of 2,256 organism-antibiotic combinations were analyzed for each system. An MIC was considered correct if two of the three systems were in agreement. When disagreements occurred, correct MICs were determined by the standard agar dilution method. With this criterion, overall agreements of the Cathra Repliscan II system, AutoMicrobic system, and Micro-Media Fox Panel system were 94.7, 94.9, and 95.5%, respectively. Tetracycline (20%), nitrofurantoin (20%), and ampicillin (16%) accounted for 56% of the discrepancies observed. These results indicate that all three systems perform with a high degree of accuracy for susceptibility testing of gram-negative bacilli.
Detection of specific immunoglobulin M antibody to rubella virus by use of an enzyme-labeled antigen
Authors: Bonfanti C , Meurman O , Halonen P
Published: January 2020

A direct antibody capture enzyme immunoassay (EIA) for the detection of rubella-specific immunoglobulin M (IgM) antibody was developed. Polystyrene microtiter strips coated with rabbit anti-human IgM were used as solid phase, and a semipurified rubella antigen labeled with horseradish peroxidase was used as indicator. By testing a panel of 238 serum specimens (not including sera from newborns with congenital rubella), the direct EIA was compared with the indirect EIA used routinely in our diagnostic unit and with a commercial IgM capture EIA (RubEnz M II) that employs a horseradish peroxidase-labeled anti-rubella monoclonal antibody as indicator. Overall agreement of direct EIA with indirect EIA and RubEnz M II was 95%, whereas agreement between direct and indirect EIA was 96.2%, and agreement between direct EIA and RubEnz M II was 97.8%. Sensitivity of the direct assay was higher than that of the indirect EIA and similar to that of the RubEnz M II assay. Specific IgM antibody could always be detected in serum specimens taken from patients with primary acute rubella infection between days 4 and 56 after the onset of rash. The assay was highly specific, and it was not affected either by rheumatoid factor or by high levels of specific IgG in sera. Another important advantage that the direct EIA has over the indirect EIA is that it requires 10 to 20 times less antigen per serum specimen tested.
Rapid neutralization assay for human cytomegalovirus antibody
Authors: Zerbini M , Plazzi M , Musiani M
Published: January 2020

Human cytomegalovirus induces the appearance of immediate early antigens in infected cells 1 h after infection. This provided the basis for the development of a rapid neutralization assay for cytomegalovirus antibody which was able to yield results within a single day. Indirect immunofluorescence to visualize immediate early antigen-positive cells was applied to the rapid determination of cytomegalovirus-neutralizing antibody. The neutralization titers obtained with this assay on 92 serum samples were in accordance with the immune status as determined by enzyme-linked immunosorbent assay to cytomegalovirus-induced immediate early, early, and late antigens.
Pyrazinamidase activity in Yersinia enterocolitica and related organisms
Authors: Kandolo K , Wauters G
Published: January 2020

Pyrazinamidase activity was tested in 381 Yersinia strains from various ecological and geographical origins and belonging to the following species: Y. enterocolitica (five biogroups), Y. intermedia, Y. frederiksenii, Y. kristensenii, Y. aldovae, Y. pseudotuberculosis, and Y. pestis. The pyrazinamidase test was negative (Pyz-) in all bioserogroups of Y. enterocolitica, in which is usually harbored the virulence plasmid, and was involved in human or animal diseases. Y. pseudotuberculosis and Y. pestis were also Pyz-. The more ubiquitous bioserogroups of Y. enterocolitica, without naturally occurring virulence plasmid, and related species were all Pyz+. Pyrazinamidase activity allowed the separation of the pathogenic North American Y. enterocolitica isolates from other nonpathogenic strains within biogroup 1. Similarly, environmental biogroups 3A and 3B were clearly distinguished from pathogenic biogroup 3. However, the pyrazinamidase test was not linked to the presence of the virulence plasmid itself and should not replace the pathogenicity tests to assess the actual virulence of an individual strain. This test proved to be a valuable tool to distinguish potential pathogenic from nonpathogenic strains of Y. enterocolitica in epidemiological surveillance programs.
Identification of Gardnerella vaginalis with the API 20 Strep system
Authors: Human R P , Tillotson G S
Published: January 2020

A total of 137 strains of Gardnerella vaginalis were examined by the API 20 Strep system. The system was shown to be reliable when the tests were compared with standard identification methods, and very little confusion occurred with streptococcal profiles; consequently, G. vaginalis has been included in the API 20 Strep data base.
Thermonuclease test for same-day identification of Staphylococcus aureus in blood cultures
Authors: Ratner H B , Stratton C W
Published: January 2020

We used a thermonuclease test to presumptively identify Staphylococcus aureus directly in blood cultures on the same day that a smear of the broth showed gram-positive cocci in clusters. There were no discrepancies between the identification of S. aureus directly from 250 blood cultures and identification by the tube coagulase test which was performed on the 18- to 24-h subculture isolates. These rapid results were clinically relevant and enabled physicians to make more timely and cost-effective decisions about antibiotic therapy.
Detection of C polysaccharide in Streptococcus pneumoniae in the sputa of pneumonia patients by an enzyme-linked immunosorbent assay
Authors: Holmberg H , Holme T , Krook A , Olsson T , Sjöberg L , Sjögren A M
Published: January 2020

The pneumococcal C polysaccharide (PnC) is species specific and believed to be a cell wall component of all pneumococcal types. A sandwich enzyme-linked immunosorbent assay (ELISA) for detection of PnC in sputa has been developed by using a monoclonal antiphosphorylcholine antibody and a polyclonal rabbit anti-PnC antiserum in the test system. A 1-year study of adult hospitalized patients with community-acquired pneumonia was performed. A total of 147 patients with clinical and radiological evidence for pneumonia were accepted for the study. Of these, 105 patients provided a sputum sample upon admission to the ward. The sputa were cultured semiquantitatively as well as tested for the presence of antigen. Of the sputum samples from patients with Streptococcus pneumoniae, 27 of 33 (accounting for a sensitivity of 82%) were positive in the ELISA test. Of the sputum samples from patients with pneumonia of some other known or suspected etiology, 32 of 34 (accounting for a specificity of 94%) were negative. In addition, 7 sputum samples from 31 patients with pneumonia of unknown etiology were positive. The ELISA test described here is in our opinion a sensitive and specific test for detecting PnC from S. pneumoniae in sputa from patients with untreated pneumonia.
Detection of hepatitis A virus and antibody by solid-phase radioimmunoassay and enzyme-linked immunosorbent assay with monoclonal antibodies
Authors: Coulepis A G , Veale M F , MacGregor A , Kornitschuk M , Gust I D
Published: January 2020

Monoclonal antibodies (K3-2F2 and K3-4C8) raised against hepatitis A virus were used to develop a solid-phase radioimmunoassay and enzyme-linked immunosorbent assay for the detection of hepatitis A virus and antibody. Assays with this pair of monoclonal antibodies were compared in parallel with similarly constructed solid-phase radioimmunoassays and enzyme-linked immunosorbent assays in which human polyclonal serum was used. The monoclonal antibody assay proved to be more sensitive for the detection of hepatitis A virus from fecal specimens as well as for anti-hepatitis A virus immunoglobulin G (IgG) and IgM in sera.
Clinical evaluation of the Lumac bioluminescence method for screening urine specimens
Authors: Martin E T , Cote J A , Perry L K , Martin W J
Published: January 2020

A bioluminescence method for screening urine cultures to provide rapid reporting of negative specimens and to select appropriate urine cultures for direct application of automated identification methods was evaluated. A total of 2,000 specimens were processed in the Lumac Biocounter (3M, St. Paul, Minn.), and the results were compared with quantitative culture techniques by using a 0.001-ml inoculating loop. A total of 841 specimens were positive by the bioluminescence method; 291 specimens were culture positive (greater than or equal to 50,000 CFU of one or two organisms per ml). Positive cultures represented more than 20 different organisms. Approximately two-thirds of the false-positive results represented mixed flora or pure cultures of less than 5 X 10(4) organisms per ml. The predictive value of a negative result was 98.4%, reflecting a false-negative rate of only 0.7%. No advantages in cost or technician time were noted, but the Lumac method appears to be a useful technique in decreasing reporting time, especially for negative urine cultures.
Comparison of enzyme-linked immunosorbent assay and complement fixation test for the detection of specific antibody in cattle vaccinated and challenged with Brucella abortus
Authors: Sutherland S S
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) and a complement fixation test (CFT) were applied to sera collected regularly from 60 cattle challenged with Brucella abortus strain 544. Of the 60 cattle, 48 were vaccinated with either B. abortus strain 19 or B. abortus strain 45/20 as calves or adults. The remaining 12 cattle were not vaccinated. Of the 27 sera from cattle found to be infected at slaughter, 9 showed aberrant reactions to the CFT in that a positive titer after challenge was delayed or transient. The performance of the ELISA in these nine cattle with aberrant reactions and the other cattle in the trial was as follows. After vaccination with strain 19 or strain 45/20, the number of weeks at which the ELISA was positive was significantly greater (P less than 0.001) than that for the CFT. The strain 19 vaccine also induced positive responses to the CFT and the ELISA for a significantly longer period (P less than 0.001) than did the strain 45/20 vaccine. For cattle with aberrant reactions, the number of weeks after challenge when the ELISA was positive was significantly greater (P less than 0.001) than that for the CFT. For noninfected cattle, the average number of weeks after challenge when the CFT was negative (35 of 40) was higher than that for the ELISA (18 of 40).
Detection of cytomegalovirus antibody with latex agglutination
Authors: Adler S P , McVoy M , Biro V G , Britt W J , Hider P , Marshall D
Published: January 2020

Transfusion-acquired cytomegalovirus (CMV) infections should be prevented in seronegative immunocompromised patients by providing blood products from donors who are also seronegative. Latex agglutination was investigated as a simple and rapid method for detecting antibody against CMV. Latex beads were coated with CMV antigen, incubated for 8 min at room temperature with 25 microliter of sera, and examined for agglutination. The sensitivity and specificity of latex agglutination was compared with that of indirect hemagglutination (IHA, Cetus Corp., Emeryville, Calif.) and enzyme immunoassay (EIA) with sera from 604 random blood donors or patients. Of 327 serum samples shown to be seronegative by EIA and IHA, 327 had a latex agglutination titer of less than 1:4 (specificity, 100%). Of 236 serum samples with detectable antibody by EIA and IHA, 228 had a latex agglutination titer of 1:4 or greater (sensitivity, 97%). Plasma collected with EDTA, heparin, or citrate was satisfactory for latex agglutination. Latex agglutination results correlated quantitatively with those of EIA, and the test also detected fourfold or greater rises in antibody with paired sera from six patients with posttransfusion CMV infections. Latex agglutination is a sensitive and specific assay that is rapid and simple to perform and should be effective in selecting seronegative blood donors to prevent posttransfusion CMV infections in seronegative recipients.
Further characterization of Bacteroides endodontalis, an asaccharolytic black-pigmented Bacteroides species from the oral S cavity
Authors: van Winkelhoff A J , van Steenbergen T J , Kippuw N , De Graaff J
Published: January 2020

In this study, the isolation, characterization, and identification of Bacteroides endodontalis is described. It was found that this asaccharolytic black-pigmented Bacteroides species is associated with infected dental root canals and oral submucous abscesses. B. endodontalis could be differentiated from B. gingivalis by a negative direct hemagglutination test and the absence of trypsin and N-acetyl-beta-glucosamidase. B. endodontalis could be differentiated from B. asaccharolyticus by the absence of alpha-fucosidase, its inability to grow in an atmosphere of 95% N2-5% H2, and a growth requirement for menadione. Immune serum raised against B. endodontalis strain HG 370T agglutinated only B. endodontalis cells. Precautions for the isolation of B. endodontalis are discussed.
Diagnosis of Colorado tick fever virus infection by enzyme immunoassays for immunoglobulin M and G antibodies
Authors: Calisher C H , Poland J D , Calisher S B , Warmoth L A
Published: January 2020

An immunoglobulin M (IgM) capture enzyme immunoassay technique was adapted for the detection of antibody to Colorado tick fever virus in sera from 84 individuals for whom diagnosis had been confirmed by virus isolation or neutralization test. Titers were compared with those for IgG and neutralizing antibodies in these Colorado tick fever cases. IgM antibody titers were higher than neutralizing antibody titers, but neither appeared until 1 to 2 weeks after the onset of illness. Neutralizing antibodies were detected earlier than IgM antibodies, and both were detected with greater frequency than IgG antibodies. Late-convalescent-phase sera contained both neutralizing and IgG antibodies, but IgM was all but undetectable by 2 months after onset. Although the neutralization test may remain the serological test of choice, the enzyme immunoassay for IgM antibody offers a simple and more rapid method of serodiagnosis; the enzyme immunoassay is, however, less sensitive than the neutralization test. Furthermore, because there was a sharp decline in IgM antibody after 45 days, the presence of IgM antibody in a single serum sample provides a basis for the presumptive serodiagnosis of recent Colorado tick fever virus infection.
Rheumatoid factor in syphilis
Authors: Cerny E H , Farshy C E , Hunter E F , Larsen S A
Published: January 2020

Immunoglobulin M (IgM) antibodies directed against IgG antibodies (rheumatoid factor [RF]) are known to occur often in patients with syphilis and to interfere with serological tests measuring specific antibodies of the IgM class. In this study we examined the occurrence and specificity of the RF and demonstrated a simple method to detect and eliminate the RF for a specific Treponema pallidum IgM enzyme-linked immunosorbent assay. We measured the occurrence of the RF with a sensitive enzyme-linked immunosorbent assay and found that it increased with the duration of syphilitic disease: 1 of 13 primary syphilis serum specimens, 3 of 13 secondary syphilis serum specimens, and 10 of 27 latent syphilis serum specimens were reactive in this RF test. Those sera containing IgM RF were immunoprecipitated with anti-human gamma chain antibodies and 2% polyethylene glycol until the RF was removed. One serum specimen from a patient in the secondary stage of syphilis and eight serum specimens from patients with latent disease still presented the RF after immunoprecipitation. Removal of the IgG antibodies also improved the sensitivity of the treponemal IgM test, indicating competition of these antibodies for binding sites of the antigen. The enzyme-linked immunosorbent assays for detection of RF and antitreponemal IgM antibodies are performed on the same plate. Theoretically, only sera positive for both tests have to be immunoprecipitated. But our findings indicated an increase in sensitivity of the IgM enzyme-linked immunosorbent assay after removal of IgG antibodies responsible for competition at the binding sites.
Occurrence of Streptococcus milleri among beta-hemolytic streptococci isolated from clinical specimens
Authors: Ruoff K L , Kunz L J , Ferraro M J
Published: January 2020

A total of 256 beta-hemolytic streptococcal isolates were subjected to serological and physiological tests to identify those which could be classified as Streptococcus milleri. S. milleri accounted for 75% of 70 group C isolates, 15% of 69 group G isolates, 75% of 16 nongroupable isolates, and 100% of 20 group F isolates examined. No S. milleri isolates were encountered among the 90 group A streptococci studied. Of the 95 beta-hemolytic S. milleri isolates examined, 81% were recovered from respiratory specimens.
Pure spherules of Coccidioides immitis in continuous culture
Authors: Petkus A F , Baum L L , Ellis R B , Stern M , Danley D L
Published: January 2020

Investigation of host-parasite relationships involving the parasitic form of Coccidioides immitis has been difficult because, previously, spherules and endospores have not been grown continuously in tissue culture medium without detectable formation of hyphae. Arthroconidia were harvested from mycelial cultures and inoculated into tissue culture flasks which contained RPMI 1640 medium supplemented with 10% calf serum and N-Tamol (Rohm & Haas Co., Philadelphia, Pa.). Flasks were purged with 5% CO2, sealed, and placed on a reciprocating shaker at 35 degrees C. Hyphae which arose during incubation were removed by filtration. Arthroconidia readily converted to the spherule-endospore form within 12 days. Six days after complete conversion, spherules and endospores were transferred to RPMI 1640 without N-Tamol. The spherule-endospore cycle was maintained in tissue culture medium for 84 days without the formation of detectable hyphae.
Comparison of the automicrobic system, acridine orange-stained smears, and gram-stained smears in detecting bacteriuria
Authors: Lipsky B A , Plorde J J , Tenover F C , Brancato F P
Published: January 2020

We compared the accuracy of the Gram-stained smear, the acridine orange-stained smear, and the AutoMicrobic system (AMS; Vitek Systems, Inc., Hazelwood, Mo.) in screening for bacteriuria, as detected by conventional cultures. For 1,024 clinical specimens, results with the acridine orange-stained smear and the Gram-stained smear were very similar. When read for the presence of one or more microorganisms or leukocytes per 20 oil immersion fields, both smears were highly sensitive (92.1 and 93.3%, respectively) and moderately specific (70.0 and 61.7%, respectively). Sensitivity was greater for specimens yielding greater than or equal to 10(5) CFU/ml (96.1 and 98.9%, respectively) than for those with 10(3) to 10(4) CFU/ml (81.4 and 78.0%, respectively). Preliminary classification based upon the tinctorial and morphological characteristics of the Gram-stained smear was compatible with culture results in nearly all cases. The accuracy of the Gram-stained smears was not influenced by special cleaning of the microscopic slides, or the level of expertise of the microscopist. For 715 specimens, the sensitivity of the AMS in detecting bacteriuria (91.5%) was very similar to that of the stained smears (92.1 and 95.7%, respectively), but the specificity was significantly higher (83.2% versus 42.6 and 70.0%). Detection of microorganisms by the AMS took an average of 6.3 +/- 3.0 h. These data suggest that the Gram-stained smear is easily interpreted, very sensitive, acceptably specific, and still the optimal rapid method for screening for bacteriuria in most clinical microbiology laboratories.
Automated reading of MIC microdilution trays containing fluorogenic enzyme substrates with the Sensititre Autoreader
Authors: Staneck J L , Allen S D , Harris E E , Tilton R C
Published: January 2020

The Sensititre Autoreader is a microcomputer-driven instrument capable of automatically reading antimicrobial susceptibility microdilution trays. The instrument measures the fluorescence liberated by bacterial enzymatic activity on fluorogenic substrates as an indicator of growth in each well. A mathematical algorithm converts the fluorescent signals from an antimicrobial dilution series to an MIC endpoint. A three-center study evaluated the performance of the Autoreader in comparison with MIC determined visually in a duplicate set of control plates lacking fluorogenic substrate. Among 828 isolates of gram-negative bacilli tested against 17 antimicrobial agents, Autoreader 18-h MIC were within +/- 1 twofold dilution of control MIC values (agreement) in 95.3% of instances. In 3.5% of the instances, Autoreader values occurred +/- 2 half-step dilutions from control values (minor discrepancy), and in only 1.2% of instances did Autoreader values deviate from control values by greater than +/- 2 dilution steps (major discrepancy). Agreement, minor discrepancies, and major discrepancies were noted among 148 gram-positive cocci tested against 11 antimicrobial agents in 93.5, 4.8, and 1.7% of the instances, respectively. Over half of the major discrepancies noted with gram-negative bacilli occurred with Proteus mirabilis-beta-lactam combinations, a problem that was resolved when a lower initial inoculum was used. Inter-and intralaboratory reproducibility was excellent. Standard Sensititre susceptibility trays may be instrument read at 18 h reproducibly and accurately with only slight modification of conventional procedures to include fluorogenic enzyme substrates in the incubation broth.
Practical recommendations for the detection of pediatric respiratory syncytial virus infections
Authors: Treuhaft M W , Soukup J M , Sullivan B J
Published: January 2020

In our private clinic-hospital setting, respiratory syncytial virus (RSV) was isolated from infants more frequently and sooner from nasal washes (84%; 4.2 days) than from throat swabs (45%; 5.5 days) or nasopharyngeal swabs (39%; 5.7 days). Immunofluorescence of nasal wash cells identified 72% of the infants with virus isolations from nasal washes in less than one day. We therefore recommend the combination of isolation and immunofluorescence on nasal wash specimens for optimal detection of RSV-infected infants. Immunofluorescence of respiratory tract cells was also useful for monitoring the presence of RSV antigen in intubation secretions during ribavirin antiviral therapy. RSV infectivity was maintained in phosphate-buffered saline at room temperature for 6 h. Transport and inoculation of specimens in less than 6 h yielded RSV isolates from 50% of sampled infants during the two RSV seasons examined. For optimal RSV isolation, we recommend inoculation of HEp-2 tubes less than or equal to 4 days old. Replacing medium after 3 days as compared with 7 days did not increase recovery of RSV and provided little practical reduction in time to detection of cytopathology.
Detection of Norwalk virus antibodies and antigen with a biotin-avidin immunoassay
Authors: Gary G W , Kaplan J E , Stine S E , Anderson L J
Published: January 2020

Biotin-avidin immunoassays (BAIs) were developed to detect Norwalk virus antigen and to measure Norwalk virus antibody. The BAI detected Norwalk virus infections by a fourfold titer rise in antibody in sera or by antigen in stool, with a sensitivity similar to or greater than that of the radioimmunoassay (RIA), and the BAI appeared to be more sensitive than the RIA for detecting antibody in single serum specimens. The BAI antigen test detected Norwalk antigen in all stools that were positive by the RIA, and in two stools negative by the RIA. Of 106 serum pairs tested by both the RIA and BAI, 94 demonstrated seroconversion, or lack of seroconversion, in both assays; 12 gave discordant results. Titers by the BAI generally exceeded those by the RIA by two- or fourfold. The BAI had advantages over the RIA in that it had added sensitivity in the detection of Norwalk antibody, was less time consuming, did not require frequent labeling of antibody, and did not have the problems associated with the use of isotopes.
Comparison of measles antihemolysin test, enzyme-linked immunosorbent assay, and hemagglutination inhibition test with neutralization test for determination of immune status
Authors: Neumann P W , Weber J M , Jessamine A G , O'Shaughnessy M V
Published: January 2020

Sera were collected from 238 high-school students in Prince Edward Island for the determination of immune status before an anticipated measles outbreak. In addition, history of vaccination status and measles infection was obtained. In the subsequent outbreak, 28 students did contract measles. Specificity for hemagglutination inhibition (HI), antihemolysin (AH), and enzyme-linked immunosorbent assay (ELISA) was 100%, compared with the neutralization test. Corresponding sensitivity values for the tests were 66.0% (HI), 99.5% (AH), and 99.0% (ELISA). Predictive values for susceptibility were 26.9% (HI), 77.8% (AH), 75.7% (ELISA), 80% (neutralization), and 41.4% as determined by history of infection or vaccination. The predictive value for immunity as determined by history of previous infection or vaccination was 91.8%, compared with 100% for the four serological tests. No false-positive results were seen with any of these tests. Compared with the neutralization test, the HI test had 69 false-negative results, the AH had 1, and the ELISA test had 2. The AH and ELISA tests provided sensitive and specific alternatives to the commonly used HI test for immune status determination.
Interleukin 2 production in whole blood culture: a rapid test of immunity to Francisella tularensis
Authors: Karttunen R , Ilonen J , Herva E
Published: January 2020

The measurement of interleukin 2 from antigen-stimulated whole blood culture supernatants was used to detect cell-mediated immunity in subjects sensitized against Francisella tularensis. The amount of interleukin 2 produced differentiated a positive immune reaction sensitively and reliably in a 24-h culture. Whole blood culturing is an easy method for producing interleukin 2.
Pseudomonas pseudomallei infection from drowning: the first reported case in Taiwan
Authors: Lee N , Wu J L , Lee C H , Tsai W C
Published: January 2020

We report a case of Pseudomonas pseudomallei infection, in which the patient acquired the bacteria by aspiration of river water after a drowning incident near Manila, the Philippines. The pulmonary form of melioidosis was noted at the onset, but septicemia developed at a later stage. Positive blood cultures were obtained 17 days after the accident. The patient was treated successfully with a combination of amikacin and cephalothin. This is the first report of P. pseudomallei infection documented in Taiwan.
Pathogenesis of herpes simplex labialis: experimental induction of lesions with UV light
Authors: Spruance S L
Published: January 2020

To develop a model system of herpes simplex labialis which would enable the study of patients before lesion onset, five patients were exposed to various doses of UV light from a sunlamp at their usual site of lesions. Six of 10 treatments resulted in the development of herpes labialis. Three of four treatments with the highest exposure levels led to large, vesicular, virus culture-positive sores. Side effects from sunlamp exposure were minimal.
Epidemiological characterization of Neisseria gonorrhoeae by lectins
Authors: Schalla W O , Whittington W L , Rice R J , Larsen S A
Published: January 2020

A total of 101 isolates of penicillinase-producing and non-penicillinase-producing Neisseria gonorrhoeae with known nutritional requirements, plasmid content, and serovars, were examined for lectin agglutination patterns. These isolates were from outbreaks in Georgia, California, Hawaii, and Pennsylvania. Cell suspensions made from 16- to 18-h cultures were mixed with 14 different lectins, and the resultant agglutination patterns were classified as agglutination groups. Among the 101 isolates tested, 24 different agglutination groups were demonstrated. Of the organisms tested, 55% were located in 3 of the 24 groups, and 86% of the isolates reacted with the lectins Trichosanthes kinlowii, Griffonia simplicifolia I, peanut agglutinin, soybean agglutinin, potato agglutinin, and wheat germ agglutinin. One isolate did not react with peanut or potato agglutinin, five isolates lacked reactivity with potato agglutinin, and six isolates did not react with wheat germ agglutinin. Of the wheat germ-negative isolates, four were from Pennsylvania and were identical with regard to auxotype, plasmid content, serovar, and lectin group. The other two wheat germ-negative isolates were from California and were unrelated by the same criteria to the four Pennsylvania isolates and to each other. Among the isolates tested, there were no differences in lectin groups with regard to the sex of the patient. In the Georgia collection, agglutination with one lectin group was confined to isolates of serogroup IA. This association was not observed for the other geographic areas. Some isolates showing identical auxotype, plasmid content, and serovars could be differentiated based on lectin agglutination patterns, whereas other isolates were identical by all testing criteria.
Occurrence of Cryptosporidium oocysts in fecal samples submitted for routine microbiological examination
Authors: Ratnam S , Paddock J , McDonald E , Whitty D , Jong M , Cooper R
Published: January 2020

During a 7-month period, 2,252 fecal samples submitted for routine microbiological examination from 1,621 patients were screened for Cryptosporidium oocysts by the auramine staining method with Kinyoun acid-fast stain as the confirmatory stain. Cryptosporidium oocysts were detected in fecal samples from 19 (1.2%) patients, 18 of whom had gastroenteritis. Diarrheic stools from 14 of these 18 patients were negative for the usual enteropathogens but contained the oocysts in moderate to large numbers. Although Cryptosporidium oocysts were found in patients of all ages, they occurred slightly more frequently in infants and children than in the rest. Cryptosporidium species was one of the common enteropathogens identified in fecal samples submitted for routine parasitological examination during the period of the survey and was second only to Giardia species in terms of frequency. Considering cryptosporidiosis in the differential diagnosis of gastroenteritis in immunocompetent persons and including a search for Cryptosporidium oocysts in routine parasitological examinations of fecal samples appear warranted.
Synergistic hemolysis exhibited by species of staphylococci
Authors: Hébert G A , Hancock G A
Published: January 2020

The synergistic hemolysis reactions of 61 reference strains and 189 clinical isolates representing 17 species of staphylococci were examined on plates of Trypticase soy blood agar (BBL Microbiology Systems, Cockeysville, Md.). Some or all of the strains of Staphylococcus aureus, S. epidermidis, S. capitis, S. cohnii, S. haemolyticus, S. hyicus, S. simulans, S. warneri, and S. xylosus produced a delta-hemolysin that gave synergistic, complete hemolysis of washed human, sheep, and ox blood cells in an area of beta-lysin activity from strains of S. aureus and S. intermedius. Strains of the same nine species were positive with a commercial beta-lysin paper disk designed for presumptive identification of group B streptococci; most of these strains also gave synergistic, complete hemolysis with exotoxin from a strain of Corynebacterium pseudotuberculosis. None of the strains of S. auricularis, S. carnosus, S. caseolyticus, S. hominis, S. intermedius, S. saprophyticus, S. sciuri, or S. lentus were positive by any of these tests for synergistic hemolysis. These results indicate that a synergistic hemolysis test could prove very useful for differentiating these species; they also suggest that one role of some of these organisms in human infections could be that of a synergist. Further studies of synergism may clarify the clinical significance of these results.
Production of 14C-labeled gas in BACTEC Neisseria Differentiation kits by Neisseria cinerea
Authors: Boyce J M , Mitchell E B , Knapp J S , Buttke T M
Published: January 2020

Six strains of Neisseria cinerea were tested in BACTEC Neisseria Differentiation kits (Johnston Laboratories, Inc., Towson, Md.), and all yielded positive glucose growth indices and negative maltose and fructose growth indices. These results were similar to those achieved with Neisseria gonorrhoeae. However, most of the N. cinerea isolates tested yielded 3-h glucose growth indices that were lower than those obtained with gonococci. 14C-labeled gas was produced significantly faster (P less than 0.02) by N. gonorrhoeae than by N. cinerea. Additional studies suggested that the 14C-labeled gas produced by N. cinerea was carbon dioxide. N. cinerea strains were similar to Branhamella catarrhalis strains because both species failed to produce detectable acid from glucose, maltose, sucrose, fructose, and lactose in cysteine-tryptic agar media. However, in contrast to N. cinerea strains, B. catarrhalis strains did not metabolize glucose in BACTEC Neisseria Differentiation kits.
Detection of Escherichia coli adhesins with DNA probes
Authors: Lanser J A , Anargyros P A
Published: January 2020

DNA hybridization assays for genes encoding the Escherichia coli adhesins K88 and K99 were developed. These assays were used to screen a variety of animal E. coli strains, and the results were compared with results obtained by serological methods. All methods compared well for determining the presence of adhesin K99. However, the DNA hybridization detected more K88-positive strains than did either enzyme immunoassay or slide agglutination. Agreement was improved when strains were grown on blood or nutrient agar instead of Minca medium.
Method for the serological typing of the capsular polysaccharides of Staphylococcus aureus
Authors: Karakawa W W , Fournier J M , Vann W F , Arbeit R , Schneerson R S , Robbins J B
Published: January 2020

A method is described for typing Staphylococcus aureus capsular polysaccharides that is based on direct bacterial cell agglutination and immunoprecipitation of cell extracts with monospecific antisera. Encapsulated strains were identified by their inagglutinability with teichoic acid antisera. The typing sera reacted specifically with extracts of eight prototype strains.
Assessment of plasmid profile, exoenzyme activity, and virulence in recent human isolates of Yersinia enterocolitica
Authors: Bottone E J , Janda J M , Chiesa C , Wallen J W , Traub L , Calhoun D H
Published: January 2020

We examined a group of 23 recent clinical isolates of Yersinia enterocolitica recovered from symptomatic patients residing in the New York, N.Y. area. These isolates were tested for the presence of plasmids, exoenzyme activity, mouse lethality, and phenotypic properties postulated to correlate with virulence. Of the 23 isolates, 17 harbored a 60- to 65-kilobase (kb) plasmid. Six isolates were lethal for white mice, showed the phenotypic markers of autoagglutination and calcium dependence for growth at 37 degrees C, and contained a 60- to 65-kb plasmid. Restriction endonuclease analysis with several different enzymes revealed the presence of three distinct plasmid profiles in these isolates. Isolates with a single plasmid of 60 to 70 kb, typical for this species, were detected, but these were of three distinct types as judged from restriction enzyme digestion. One strain was unusual among clinical isolates of Y. enterocolitica in that it contained at least four distinct plasmids. In addition, this nontypable strain showed exoenzymatic activity similar to that of serogroup O8 isolates, was not lethal to mice, and did not require calcium for growth at 37 degrees C.
Nasal carriage of Staphylococcus aureus and antistaphylococcal immunoglobulin E antibodies in atopic dermatitis
Authors: Falanga V , Campbell D E , Leyden J J , Douglas S D
Published: January 2020

Twelve atopic dermatitis patients were studied to investigate the relationship between levels of antistaphylococcal immunoglobulin E antibodies in serum and quantitative cultures of Staphylococcus aureus strains from the anterior nares and chronic lesions. A positive correlation was found between logarithmic counts of S. aureus strains from the anterior nares and levels of antistaphylococcal immunoglobulin E in serum. The observation is important for understanding the pathophysiology of atopic dermatitis.
Concurrent infection of pigs with enterotoxigenic Escherichia coli of different serogroups
Authors: Francis D H , Wilson R A
Published: January 2020

Naturally occurring dual infections with Escherichia coli of different serogroups occurred in 12 pigs 2 to 14 days of age. In each case, one isolate was hemolytic and produced K88 pili and the other was nonhemolytic and produced either K99 or 987P pili.
Two similar but atypical strains of coryneform group A-4 isolated from patients with endophthalmitis
Authors: Coudron P E , Harris R C , Vaughan M G , Dalton H P
Published: January 2020

Corynebacterium species and other coryneform organisms isolated from clinical specimens are frequently considered contaminants. We isolated two strains of a gram-positive organism from the vitreous fluid of two patients with endophthalmitis who had previously received intraocular lens transplants. The biochemical characteristics and gas chromatographic patterns of both isolates were similar to those of coryneform group A-4 strains. Major differences included esculin hydrolysis, nitrate reduction, growth pigment, and lactic acid production. These two strains along with a limited number of strains collected at the Special Bacterial Pathogens Laboratory (Division of Bacterial Diseases, Centers for Disease Control, Atlanta, Ga.) may represent a subgroup of coryneform group A-4. Results of in vitro susceptibility testing performed with antimicrobial agents commonly used to treat patients with bacterial endophthalmitis underscore the importance of determining MBCs for slow-growing organisms. This report cautions microbiologists not to discard organisms frequently considered contaminants when isolated from body fluids that are normally sterile and from patients receiving local steroids.
Immunoglobulin responses in acute Q fever
Authors: Dupuis G , Péter O , Peacock M , Burgdorfer W , Haller E
Published: January 2020

Knowledge of the development of different classes of antibody during the course of acute Q fever is important to the clinician for interpreting a patient's serological test results. In the present study, the appearance of antibodies to Coxiella burnetii phases I and II was determined for a period of 1 year. A total of 683 sera from 191 patients with symptomatic Q fever were evaluated by the complement fixation and indirect immunofluorescence (immunoglobulins M and G [IgM, IgG]) tests. These patients had contracted acute Q fever in the fall of 1983 during an epidemic that resulted in 415 serologically confirmed cases of Q fever. As demonstrated by the complement fixation test, antibodies to C. burnetii phase II remained elevated throughout the entire study period, whereas antibodies to phase I were barely detectable. Although the immunofluorescence test was more sensitive than the complement fixation test, the specific anti-IgG response to C. burnetii to phases I and II gave the same general antibody profiles as did the complement fixation test. IgM anti-phase I and II titers appeared earlier but disappeared after 10 to 12 weeks. During this period, anti-phase II antibody levels were generally much higher than anti-phase I antibody levels.
Lack of reliability of primary grouping of beta-hemolytic streptococci by culture of throat swabs with streptocult supplemented with bacitracin disks in general practice
Authors: Hoffmann S
Published: January 2020

Fifty-eight general practitioners took throat swabs from 434 patients with sore throats. Office cultures were performed on Streptocult supplemented with bacitracin disks in an attempt to carry out primary grouping of beta-hemolytic streptococci (BHS). In 424 cases the findings were compared with those obtained in a microbiological laboratory. Streptocult showed a sensitivity of 75% and a specificity of 84% in the detection of BHS. The office-performed grouping procedure of the correctly detected BHS, however, only had a sensitivity of 65% and a specificity of 87%. Overall, as many as 45% of the patients with BHS group A were misdiagnosed. The unsatisfactory results obtained with primary grouping of BHS may be due partly to incorrect determinations of the diameter of the inhibition zone around the bacitracin disks and partly to an inappropriate choice of breakpoint. It is concluded that cultures of throat swabs on Streptocult in general practice should not be accompanied by attempts to carry out primary grouping with bacitracin disks. A laboratory investigation showed that incubation at room temperature for 48 h and at 35 degrees C for 24 h gave identical BHS positivity rates.
Zygomycosis caused by Apophysomyces elegans
Authors: Wieden M A , Steinbronn K K , Padhye A A , Ajello L , Chandler F W
Published: January 2020

A case of zygomycosis caused by Apophysomyces elegans in a diabetic, obese female is described. The fungus gained entry into the body through injury to the skin, penetrating the keratin, epidermis, and dermis. Hyphal angioinvasion was observed. Fungal elements invaded the subcutaneous fat, skeletal muscle fibers, nerves, and large blood vessels, resulting in the spread of the infection. The rapidity with which A. elegans invaded the blood vessels left no choice except amputation of the leg to stop the spread of the infection. This zygomycetous fungus closely resembles Absidia corymbifera. It is distinguished by its prominent campanulate apophyses. In its gross colony characteristics and failure to sporulate on routinely used media it resembles Saksenaea vasiformis.