bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of three reagents for detecting indole production by anaerobic bacteria in microtest systems
Authors: Lombard G L , Dowell V R
Published: January 2020

Three reagents for detecting indole, Kovac, Ehrlich, and p-dimethylaminocinnamaldehyde (DMCA), were evaluated with commercial microtest systems for characterizing and identifying anaerobic bacteria. The DMCA reagent, the most sensitive of the three reagents, gave a positive reaction with 445 of 449 strains of various indole-producing anaerobic bacteria. There was 99.6% agreement between the results obtained with the DMCA in the microtest systems and results using the conventional tube test to detect indole by using xylene extraction and Ehrlich reagent. Ehrlich reagent detected indole in 163 of 176 (92.6%) indole-positive strains when the inoculum was overlaid with mineral oil before incubation. Kovac reagent was the least sensitive of the reagents tested. When the inoculum was overlaid with mineral oil, Kovac reagent detected only 80 of 108 (74.0%) of indole-positive strains. In addition to being the most sensitive reagent for detection indole, DMCA also allowed detection of indole derivatives (skatole, 3-indolepropionic acid, and 3-indolebutyric acid) produced by some clostridia.
Comparison of three methods for anaerobe identification
Authors: Appelbaum P C , Kaufmann C S , Keifer J C , Venbrux H J
Published: January 2020

In this study we evaluated the ability of three commercial methods, API 20A (Analytab Products, Plainview, N.Y.), Minitek (BBL Microbiology Systems, Cockeysville, Md.), and Anaerobe-Tek (Flow Laboratories, Inc., McLean, Va.), to accurately identify 165 recent clinical and 38 stock isolates of anaerobic bacteria without supplemental tests or gas-liquid chromatography. Strains included 89 Bacteroides spp., 12 fusobacteria, 10 gram-positive, nonsporing rods, 43 Clostridium spp., 15 Streptococcus intermedius, 18 peptococci, 6 peptostreptococci, 3 Staphylococcus saccharolyticus, and 7 Veillonella spp. The methods used were those of manufacturers, without supplemental tests. API 20A correctly identified 70.0% of strains to species and 6.4% to genus only, with 17.2% as part of a spectrum of identifications and 6.4% incorrect. Minitek, according to the current code book, yielded 69.5% correct identifications to species, 16.8% spectrum identifications, and 13.8% incorrect. Anaerobe-Tek correctly identified 64.0% of strains to species, 21.2% spectrum identifications, and 14.8% incorrect. Thirteen strains were misidentified by API 20A, 28 were misidentified by Minitek, and 30 were misidentified by Anaerobe-Tek. For laboratories without gas-liquid chromatography support and where identification of clinically significant Bacteroides fragilis and Clostridium perfringens is desired, any of the three systems would provide accurate information. For more extensive anaerobe identification, including the less frequently isolated, more unusual organisms, API 20A and Minitek are preferred at this time. All systems have identification schemes associated with a percentage of misidentifications, the most recently introduced Anaerobe-Tek system being associated with the highest error rate.
Clinical laboratory evaluation of a urine screening device
Authors: Pfaller M A , Baum C A , Niles A C , Murray P R
Published: January 2020

A study was conducted to compare the Bac-T-Screen Bacterial Detection Device for Urines (BDD; Marion Laboratories, Kansas City, Mo.) with urine Gram stain as a screen for bacteriuria. We analyzed 631 urine samples with the BDD and compared the results to urine Gram stains and quantitative cultures. A total of 90 (14%) specimens could not be analyzed with the BDD due to interfering pigments (67 specimens) or clogging of the filter (23 specimens). Of the 541 specimens that were analyzed, the BDD correctly identified 67 (88.2%) of the 76 specimens with greater than or equal to 10(5) CFU/ml but only 294 (63.2%) of the 465 specimens with less than 10(5) CFU/ml. The majority of the false negative specimens had either gram-positive organisms or yeasts. The predictive value of a negative BDD reading was 97.0%. The urine Gram stain correctly identified 92.1% of all positive cultures and 77.8% of all negative cultures. The predictive value of a negative urine Gram stain was 98.4%. In summary, the BDD compares favorably with the urine Gram stain as a screen for bacteriologically negative urine specimens.
Effects of trimethoprim-sulfamethoxazole and incubation atmosphere on isolation of group A streptococci
Authors: Libertin C R , Wold A D , Washington J A
Published: January 2020

The effects of selective media and incubation atmosphere on the isolation of group A beta-hemolytic streptococci were evaluated. A higher percentage of group A streptococci was isolated on sheep blood agar incubated in air than in CO2 or anaerobic atmospheric conditions. Fewer non-group A beta-hemolytic streptococci were isolated on sheep blood agar incubated in air than in CO2 or anaerobically. Group A streptococcal isolation was not significantly affected by different incubation atmospheres on sheep blood agar containing trimethoprim-sulfamethoxazole, but detection time was longer than on sheep blood agar alone. No significant difference was found between isolation of group A streptococci on sheep blood agar incubated in air and that on sheep blood agar containing trimethoprim-sulfamethoxazole and incubated in 5 to 10% CO2; however, more group A streptococci were isolated on sheep blood agar in air within 24 h. Sheep blood agar incubated at 35 degrees C in air is, therefore, recommended for the isolation of group A streptococci from throat swabs.
Evaluation of the BACTEC radiometric method for recovery of mycobacteria and drug susceptibility testing of Mycobacterium tuberculosis from acid-fast smear-positive specimens
Authors: Roberts G D , Goodman N L , Heifets L , Larsh H W , Lindner T H , McClatchy J K , McGinnis M R , Siddiqi S H , Wright P
Published: January 2020

A total of 463 respiratory specimens, all smear positive for acid-fast bacteria, were inoculated onto routine solid media and into BACTEC 7H12 Middlebrook medium for detection of mycobacterial growth. Conventional drug susceptibility testing (1% proportion method) was performed on Middlebrook 7H10/7H11 medium, and radiometric susceptibility testing was performed on BACTEC 7H12 medium. The average detection times for BACTEC-positive cultures were 8.3 days for Mycobacterium tuberculosis and 5.2 days for mycobacteria other than tuberculosis; by conventional methods, they were 19.4 and 17.8 days, respectively. These detection times do not include time required for identification, which was done by the conventional method only. There was an excellent correlation in the recovery rates of mycobacteria by the two methods. Drug susceptibility test results of M. tuberculosis isolates by the two methods showed 95.1 to 100% overall agreement. The average reporting time for drug susceptibility results ranged from 4.2 to 6.9 days for the BACTEC method and 13.7 to 21 days for the conventional methods. An average of 18 days was required by the BACTEC method for complete recovery and drug susceptibility testing of M. tuberculosis, as compared with 38.5 days for the conventional methods.
Viability of organisms held in the isolator blood culture system for 15 h and their rapid detection by acridine orange staining
Authors: Cashman J S , Boshard R , Matsen J M
Published: January 2020

Sets of three Isolator blood culture tubes were seeded with low numbers of 96 strains of 26 bacterial species (fresh and stock clinical isolates). One tube was processed immediately, and the other two were held at 22 and 34 degrees C for 15 h before processing. Organism recovery was 99, 99, and 98%, respectively. Organism numbers increased at both 22 degrees C (60% of strains) and 34 degrees C (79% of strains). Especially notable was that the increases were seen with most strains of Staphylococcus aureus, streptococcal species, Pseudomonas, and all of the Enterobacteriaceae tested. Seven strains, including Streptococcus pneumoniae and Haemophilus influenzae, although viable, were recovered with a decreased number of organisms at each temperature. Acridine orange staining detected organisms in 53% of those Isolator tubes being held and 71% of those demonstrating a numerical increase, after incubation at 34 degrees C. In addition, it was noted that after processing, 48% of the strains that had increased in number while being held at 34 degrees C resulted in visible growth on agar media in 6 h. The results suggest that up to a 15-h delay in processing Isolator tubes may be possible and that acridine orange staining for the rapid detection of positive cultures may be useful in such a circumstance.
Quantitation of Giardia cysts by membrane filtration
Authors: Spaulding J J , Pacha R E , Clark G W
Published: January 2020

A method of fixing and staining Giardia cysts on a membrane filter is reported. This procedure appears to be a reliable method for the recovery and detection of cysts and also for the determination of cyst densities. Evaluation and possible applications of the technique are described.
Rapid identification of Staphylococcus aureus in blood cultures by thermonuclease testing
Authors: Madison B M , Baselski V S
Published: January 2020

The detection of thermonuclease activity in 86 blood culture samples containing gram-positive cocci showed 100% correlation with the subsequent identification of the isolate as Staphylococcus aureus by the coagulase test. No positive thermonuclease results were found with 66 samples containing coagulase-negative staphylococci and 56 samples containing other gram-positive organisms. The thermonuclease test provides a rapid, reliable method to identify S. aureus in blood cultures.
Pneumonia and bacteremia associated with Haemophilus influenzae serotype d
Authors: Holmes R L , Kozinn W P
Published: January 2020

Haemophilus influenzae serotype d was isolated from three women with pneumonia and underlying cardiopulmonary disease. Two of the strains were isolated from blood, and the third strain was isolated from sputum. The biotypes of the isolates were I, IV, and VI.
Rapid identification of Serratia marcescens by coagglutination
Authors: Roig J M , Dorronsoro I , Diaz R
Published: January 2020

All 20 O serotypes of Serratia marcescens produce a common, soluble antigen. Crude antigen was obtained by ammonium sulfate precipitation of spent growth medium, antiserum was produced in rabbits, and a coagglutination test for rapid identification of S. marcescens was developed. A total of 701 clinical isolates of gram-negative bacilli were examined, and a 100% correlation between biochemical identification of S. marcescens and identification by coagglutination was found.
Rapid detection of clindamycin resistance in Bacteroides spp
Authors: Murray P R , Weber C J
Published: January 2020

High-level resistance to clindamycin can be accurately detected by the Wadsworth disk identification test. Of the 98 isolates of the Bacteroides fragilis group that were tested, 90 were inhibited by the 60-micrograms erythromycin disk and had clindamycin minimal inhibitory concentrations of less than or equal to 3.2 micrograms/ml. Of the remaining eight isolates, all were resistant to the erythromycin disk and had clindamycin minimal inhibitory concentrations of greater than or equal to 100 micrograms/ml.
Haemophilus influenzae biotype VII
Authors: Gratten M
Published: January 2020

A hitherto unreported biotype of Haemophilus influenzae is described. The isolate is noncapsulate and fails to decarboxylate ornithine or hydrolyze urea but is a strong indole producer. Its frequency is low. It is suggested that this newly recognized biotype of H. influenzae be designated biotype VII.
Routine use of BACTEC 16B bottles to remove antibacterial and antitumor agents from blood cultures of cancer patients
Authors: Hopfer R L , Moore D G , Fainstein V , Watkins S , Wenglar M
Published: January 2020

A total of 1,764 paired sets of BACTEC 6B and 16B blood culture bottles were collected from patients for analysis. The majority of the patients were receiving antibiotic therapy at the time the blood specimens were collected. A total of 126 isolates were considered clinically significant. Of these, 58 grew in both 6B and 16B bottles, 25 grew only in 6B bottles, and 43 grew only in 16B bottles. In both bottles, the same amount of time was required to detect a positive culture. In 18 patients, septicemias were detected in the 16B bottles that were not detected in the 6B bottles. In seven patients, microorganisms were detected in the 6B bottles that were not detected in the 16B bottles. Interestingly, the antibiotic therapy was changed for only 4 of the 18 patients whose septicemias were detected only in the 16B bottles. Finally, an in vitro study showed that certain chemotherapeutic agents can cause the inhibition of growth of several microorganisms when tested in 6B bottles. These inhibitory effects were reduced or eliminated when the same organism-drug combinations were tested in 16B bottles.
Method for concentration of parasites from small amounts of feces
Authors: Levine J A , Estevez E G
Published: January 2020

A total of 258 formalinized stool specimens received in our clinical laboratory were examined for parasites by direct smears and by the standard Formalin-ethyl acetate (FEAc) concentration method. Microconcentration (MC), a miniaturization of the FEAc method, was compared with the standard method for efficiency of parasite recovery. MC employed 0.25 to 0.50 ml of formalinized stools, 0.5 ml of Formalin, and 0.25 ml of ethyl acetate; the washing steps were omitted, whereas the rest of the procedure remained the same as the FEAc method. A total of 36 (13.9%) specimens were positive for parasites; of these, 23 (63.9%) were negative on direct examination. In 14 of these 23 specimens, the FEAc and MC methods were equivalent in detecting parasites. MC failed to detect parasites in eight specimens that were positive by FEAc and detected a parasite in one specimen that was negative by FEAc. Of 14 specimens positive by both concentration methods, FEAc detected additional parasite species in 2 specimens and MC did so in 1 specimen. The reduced sensitivity of parasite concentration evident in the MC we believe to be exclusively due to the drastically reduced sample size. We propose MC as an alternative to the FEAc concentration method when only small amounts of feces can be obtained.
Characterization, serological specificity, and diagnostic possibilities of monoclonal antibodies against Legionella pneumophila
Authors: Guillet J G , Hoebeke J , Tram C , Marullo S , Strosberg A D
Published: January 2020

Hybridoma-producing monoclonal antibodies against Legionella pneumophila were produced by the fusion of nonsecreting mouse myeloma cells (NS-1) with splenocytes of BALB/c mice immunized by heat-killed L. pneumophila of serogroup I. Of 96 wells, 85 produced clones, of which 28 were positive as measured by an enzyme-linked immunosorbent assay technique. Ten of the hybridoma supernatants, remaining positive after 2 months of culture, were tested against the other Legionella serogroups and the atypical strains. None showed significant cross-reaction. Six of the positive clones were subcloned by limiting dilution, and two subclones were put into ascites in BALB/c mice. The monoclonal antibody obtained from the II-6-18 subclone was of the gamma-3 isotype. In this report, we describe the conditions for the use of this monoclonal antibody as a diagnostic tool for the detection of serogroup I L. pneumophila.
Vibrio furnissii (formerly aerogenic biogroup of Vibrio fluvialis), a new species isolated from human feces and the environment
Authors: Brenner D J , Hickman-Brenner F W , Lee J V , Steigerwalt A G , Fanning G R , Hollis D G , Farmer J J , Weaver R E , Joseph S W , Seidler R J
Published: January 2020

Strains formerly classified as the aerogenic (gas-producing) biogroup of Vibrio fluvialis were shown by DNA relatedness to be a separate species. The species was named Vibrio furnissii sp. nov. (type strain ATCC 35016 = CDC B3215). Three strains of V. furnissii were 79% or more related to the type strain of V. furnissii and about 50% related to the type strain of V. fluvialis. V. fluvialis strains were 40 to 64% related to the type strain of V. furnissii. Divergence in related sequences was only 0.0 to 1.5% among strains of V. furnissii and among strains of V. fluvialis but was 5.0 to 8.0% in interspecific reactions between V. fluvialis and V. furnissii. V. furnissii was aerogenic (produced gas from the fermentation of carbohydrates), whereas V. fluvialis was anaerogenic (did not produce gas from the fermentation of carbohydrates). Another test of some help in differentiating the two species was fermentation of L-rhamnose (57% positive for V. furnissii and negative for V. fluvialis). In addition to the reactions above, V. furnissii is distinguished from other salt-requiring vibrios on the basis of its positive reactions in tests for Møller L-arginine, L-arabinose, maltose, and D-mannitol and its negative reactions for Møller L-lysine and L-ornithine, lactose, and Voges-Proskauer. V. furnissii has been isolated from patients with acute gastroenteritis in at least two outbreaks of food poisoning; its role as a cause of diarrhea needs further study.
Medium-dependent zone size discrepancies associated with susceptibility testing of group D streptococci against various cephalosporins
Authors: Sahm D F , Baker C N , Jones R N , Thornsberry C
Published: January 2020

Mueller-Hinton (MH) agar media from various commercial sources, either supplemented or not supplemented with 5% sheep blood, were studied to determine their effect on disk diffusion susceptibility testing results obtained with 90 strains of group D streptococci and four cephalosporins. The cephalosporins investigated included cephalothin, cefamandole, moxalactam, and cefotaxime. Results showed that a number of Streptococcus faecalis and Streptococcus faecium strains were susceptible to cephalothin, cefamandole, and cefotaxime, but the number varied with both the commercial source and blood content of the MH medium used. Regardless of the MH medium used, none of the S. faecalis or S. faecium strains were found to be susceptible to moxalactam. The apparently medium-associated variations in the number of strains susceptible to cephalothin, cefamandole, and cefotaxime were largely due to minor discrepancies (one result being intermediate) among the various types of MH media used. However, major discrepancies (one result being resistant and the other susceptible or vice versa) were observed when S. faecalis strains were tested against cefotaxime. These major discrepancies were associated with both the commercial source of the MH medium and the blood content of the medium.
Detection of urinary Vi antigen as a diagnostic test for typhoid fever
Authors: Taylor D N , Harris J R , Barrett T J , Hargrett N T , Prentzel I , Valdivieso C , Palomino C , Levine M M , Blake P A
Published: January 2020

Since Vi antigen is limited primarily to Salmonella typhi, it has been thought that detection of the antigen may be a useful method for diagnosing acute typhoid fever. The slide coagglutination method and enzyme-linked immunosorbent assay have recently been suggested as ways to detect small quantities of Vi antigen in urine. In Santiago, Chile, we compared the results of these two methods in patients with acute typhoid fever, paratyphoid fever, and other febrile illnesses and in afebrile control subjects. Using a cut-off value that maximally separated typhoid patients from controls, the enzyme-linked immunosorbent assay was positive in 62.4% of 141 patients with culture-proven typhoid infections and in 13.2% of 159 afebrile control subjects. The enzyme-linked immunosorbent assay was false positive in 64.7% of 34 culture-proven paratyphoid A or B patients and 47.1% of 21 patients with other nontyphoidal febrile illnesses. The coagglutination test was positive in 34% of typhoid patients, 14% of afebrile control subjects, and 46% of febrile control subjects. We conclude that these tests when performed with the Vi antibodies employed in this study are of little value for the diagnosis of typhoid fever in this setting.
Campylobacter jejuni and Campylobacter coli serotypes isolated from chickens, cattle, and pigs
Authors: Munroe D L , Prescott J F , Penner J L
Published: January 2020

A total of 191 Campylobacter jejuni and 125 Campylobacter coli were isolated from the intestinal content of 398 chickens, 421 cattle, and 203 pigs. All 108 chicken isolates and 73 of 80 cattle isolates were C. jejuni, but 115 of the 118 pig isolates were C. coli. A total of 84% of the C. jejuni and 64% of the C. coli isolates were typed on the basis of thermostable antigens with 20 antisera prepared against frequently occurring serotypes in Campylobacter enteritis in man (15 C. jejuni, 6 C. coli serotypes). A total of 96% of the chicken isolates and 67% of the cattle isolates belonged to 11 C. jejuni serotypes that occur most frequently in human cases of enteritis (serotypes 1, 2, 3, 4, 5, 13/16, 18, 21, 23, 31, and 36). Serotype 8, a relatively common human isolate, was not recovered. The C. coli isolates from pigs belonged to serotypes uncommon among human isolates.
Evaluation of latex-Rickettsia rickettsii test for Rocky Mountain spotted fever in 11 laboratories
Authors: Hechemy K E , Michaelson E E , Anacker R L , Zdeb M , Sasowski S J , Kleeman K T , Joseph J M , Patel J , Kudlac J , Elliott L B
Published: January 2020

A latex-Rickettsia rickettsii test for detection of antibodies to Rocky Mountain spotted fever (RMSF) was evaluated during the 1980 RMSF season in 11 laboratories in nine states where the disease is endemic. In a double-blind study, all sera submitted to each laboratory for RMSF testing were also examined by the latex-R. rickettsii test. A portion of each specimen was then sent to the New York State laboratory for testing by latex-R. rickettsii and by the reference microimmunofluorescence test. Results were exchanged at the end of the examination period. At the usual ratio of reactive to nonreactive sera encountered in a diagnostic laboratory on a day-to-day basis, the efficiency of the latex-R. rickettsii test relative to microimmunofluorescence was 96.79% for New York and 93.30% for the collaborating laboratories. Both the latex and microimmunofluorescence tests detected antibodies to RMSF within 7 to 9 days of onset. With the latex-R. rickettsii test--but not necessarily with microimmunofluorescence--a high titer (greater than or equal to 128) on a single serum was diagnostic of active RMSF. Changes in serum titer for patients with multiple sera were similar for both tests. The test detects rickettsial antibodies in patients with active infection, but in most cases it does not detect antibody in patients with past infection. Test reactivity could not be uniquely linked to a particular immunoglobulin class.
Increased immunofluorescent staining of rabies-infected, formalin-fixed brain tissue after pepsin and trypsin digestion
Authors: Reid F L , Hall N H , Smith J S , Baer G M
Published: January 2020

This study was undertaken to evaluate the sensitivity of the direct immunofluorescence test on Formalin-fixed, trypsin-digested, rabies-infected brain tissue. Our results suggest that the optimal unmasking of rabies antigenic sites is obtained by using a double enzyme digestion with pepsin and trypsin in lieu of only trypsin.
New characteristics of Mycobacterium haemophilum
Authors: Ryan C G , Dwyer B W
Published: January 2020

The first isolation of Mycobacterium haemophilum in Victoria was from 8-month-old leg lesions in an immunosuppressed renal transplant patient. Characteristics of the isolate that had not been described previously for M. haemophilum included growth enhancement by carbon dioxide, a temperature optimum that was lower than previously reported, and the surprisingly slow growth of the primary isolate.
Multicenter evaluation of the proposed quality control limits and interpretive zone standards for in vitro susceptibility testing with norfloxacin
Authors: Shungu D L , Tutlane V , Gadebusch H H
Published: January 2020

A seven-center collaborative study was carried out to evaluate the in vitro performance of the 10 micrograms norfloxacin disks on the basis of previously proposed interpretive susceptibility zone standards and quality control parameters. Of 7,858 clinical isolates tested, 93.2, 4.9, and 1.9% fell into the susceptible, moderately susceptible, and resistant groups, respectively. The quality control data based on a total of 1,368 zone diameter measurements compared quite favorably with the proposed performance limits as follows: Escherichia coli ATCC 25922, 28 to 35 mm versus 28 to 36 mm; Staphylococcus aureus ATCC 25923, 21 to 29 mm versus 17 to 29 mm; and Pseudomonas aeruginosa ATCC 27853, 23 to 27 mm versus 22 to 29 mm.
Simple new test for rapid differentiation of Prototheca wickerhamii from Prototheca zopfii
Authors: Casal M J , Gutierrez J
Published: January 2020

A simple new test to differentiate Prototheca wickerhamii from Prototheca zopfii by determining susceptibility to clotrimazole is described. A 50-micrograms clotrimazole disk provides a rapid and reliable means of distinguishing P. wickerhamii from P. zopfii.
Comparison of radioimmunoassay and fluorescent polarization immunoassay for quantitative determination of vancomycin concentrations in serum
Authors: Ackerman B H , Berg H G , Strate R G , Rotschafer J C
Published: January 2020

A new fluorescent polarization immunoassay (Abbott Laboratories, Diagnostics Division, North Chicago, Ill.) was compared with a standard radioimmunoassay (American Diagnostics Corp., Newport Beach, Calif.) in 34 patients being treated with vancomycin. A total of 123 serum samples were divided and quantitatively analyzed for vancomycin by both assay methods. The results obtained indicated that the two assay methods are comparable (y = 1.01x - 0.81; r = 0.99).
Development of a test system for rapid differentiation of Neisseria and Haemophilus spp
Authors: Eriquez L A , Hodinka N E
Published: January 2020

A qualitative micromethod (IDS Rapid NH system) employing conventional and single-substrate enzyme tests was developed for the biochemical characterization of Neisseria spp., Haemophilus spp., and other gram-negative species. A total of over 140 dehydrated, miniaturized biochemical tests were investigated for their ability to distinguish species. Computer-assisted test selection and pair separation analysis of the data allowed the selection of 11 4-h tests that would identify Haemophilus and Neisseria spp. implicated as etiological agents as well as differentiate them from other Neisseria spp., Moraxella spp., Branhamella catarrhalis, Centers for Disease Control M groups, and Kingella spp. The final test configuration included modified glucose, sucrose, galactosidase, nitrate, phosphatase, resazurin reduction, and two arylamidase tests. In addition, indole, urea, and ornithine decarboxylase tests were included to biochemically type strains of Haemophilus influenzae and Haemophilus parainfluenzae.
Serum antibodies to enterotoxins produced by Staphylococcus aureus with special reference to enterotoxin F and toxic shock syndrome
Authors: Notermans S , van Leeuwen W J , Dufrenne J , Tips P D
Published: January 2020

The presence of antibodies to staphylococcal enterotoxins (enterotoxins A through F) in sera of healthy subjects (n = 567) and in sera of patients with toxic shock syndrome (n = 20) was determined. Furthermore, production of enterotoxins by Staphylococcus aureus isolated from humans was investigated. In 46, 86, 78, 41, 20, and 91% of the sera of healthy subjects, antibodies were found against enterotoxins A, B, C, D, E, and F, respectively. The high percentage of sera with antibodies against enterotoxin F correlated with the relatively high frequency of enterotoxin F-producing S. aureus isolated from humans (one-third of the isolates produced enterotoxin F). In patients with toxic shock syndrome, antibodies against enterotoxin F were not present or were present only at very low levels. An increase of antibodies after onset of the disease was observed in two of eight patients investigated. From the results, it can be concluded that only those humans who show low levels of antibodies are susceptible to toxic shock syndrome.
Oropharyngeal colonization with Legionella pneumophila
Authors: Bridge J A , Edelstein P H
Published: January 2020

A total of 186 volunteers, including 40 hospital patients, participated in a cross-sectional survey of oropharyngeal colonization with Legionella pneumophila. Colonization was defined as the appearance of any L. pneumophila organisms on culture or a positive direct fluorescent-antibody (FA) test or both in the absence of signs or symptoms of pneumonia. The direct FA tests were performed on throat swabs, using a polyvalent conjugate directed against L. pneumophila serogroups I through IV. Throat swabs were cultured for L. pneumophila on a selective medium. Blood specimens were tested for antibody, using an indirect FA test and heat-killed polyvalent antigen for L. pneumophila serogroups I through IV. Eight people, none of whom had pneumonia or fever, had positive direct FA tests; no subject had a positive culture for L. pneumophila. Whether the positive direct FA results represent colonization cannot be stated with assurance. In any case, the results suggest that colonization occurs infrequently.
Comparison of slide agglutination test and direct immunofluorescence assay for identification of Legionella isolates
Authors: Thacker W L , Wilkinson H W , Benson R F
Published: January 2020

It is technically impractical for many clinical laboratories to use the direct immunofluorescence assay for identifying and serogrouping clinical isolates of Legionella. We compared the results obtained with the direct immunofluorescence assay with the results of a simple and less-demanding slide agglutination test for identifying 15 serogroups representing seven Legionella species. The slide agglutination test was in complete agreement with the direct immunofluorescence assay, and the serogroup to which 64 clinical isolates of Legionella belonged was correctly identified. With polyvalent, pooled antisera and absorbed, serogroup-specific antisera, the slide agglutination test is a useful alternative to the direct immunofluorescence assay in the diagnosis of Legionella infections and for studying the serological relationships of Legionella-like organisms.
Use of the Rapid STREP system for identification of viridans streptococcal species
Authors: Ruoff K L , Kunz L J
Published: January 2020

A commercially available streptococcal identification system, Rapid STREP (API System S.A., Montalieu-Vercieu, France), was used to identify 119 viridans strains at the species level. A total of 92% of the strains tested were identified correctly with the Rapid STREP system, and 81% of the correct identifications were made at percentages of identification of 90 or greater. From these data it appears that the Rapid STREP system is a fairly accurate and rapid (24-h incubation) method for identifying species of viridans streptococci.
Serum immunoglobulin A antibody to varicella-zoster virus in subjects with primary varicella and herpes zoster infections and in immune subjects
Authors: Wittek A E , Arvin A M , Koropchak C M
Published: January 2020

Immunoglobulin A (IgA) antibodies to varicella-zoster virus (VZV) were measured in sera from subjects with acute varicella and herpes zoster, VZV-immune subjects remote from infection, and recipients of a live attenuated varicella vaccine, using a solid-phase radioimmunoassay. Primary infection with VZV was associated with early production of IgA antibodies. Among 36 subjects with varicella tested 1 to 5 days after onset, 22 had detectable IgA, and all of the negative sera were obtained before day 3 of the varicella exanthem. VZV IgA was detected in one of three sera obtained more than 60 days after onset of the illness. Four of five sera obtained from subjects within 1 week of the onset of herpes zoster had measurable levels of IgA. Between 1 and 4 weeks after onset of zoster, all 10 subjects tested had detectable IgA to VZV. VZV IgA was detected as late as 63 days after the onset of herpes zoster. Of 10 vaccine recipients, 5 developed VZV IgA which was detected as early as 4 weeks and persisted for as long as 16 weeks after vaccination. VZV IgA was not detected in sera from 42 children who had no detectable IgG antibody to VZV. VZV IgA was found on only 3 of 23 sera from adults who had varicella more than 20 years before.
Enzyme-linked immunosorbent assay for detection of capsular antibodies against Haemophilus influenzae type b: comparison with radioimmunoassay
Authors: Kaplan S L , Mason E O , Johnson G , Broughton R A , Hurley D , Parke J C
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) is described for detection of anti-capsular antibodies against Haemophilus influenzae type b. Polyribosephosphate was covalently bonded to poly-L-lysine before adsorption to microtiter plates. ELISA immunoglobulin G and immunoglobulin M anti-polyribosephosphate antibody titers were comparable to total anti-polyribosephosphate antibody concentration determined by radioimmunoassay. The ELISA technique will be useful for further investigations of host response to infections due to H. influenzae type b but is not intended to be used as a serological method for documenting H. influenzae type b infections.
Detection of oxacillin-resistant staphylococci by the AutoMicrobic system
Authors: Stotler R W , Meyer M C
Published: January 2020

The AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) is an automated instrument designed for rapid microbiological identification and susceptibility reporting in the clinical laboratory. The reliability of a rapid, automated approach to testing methicillin-resistant staphylococci was evaluated. To determine the accuracy in detecting oxacillin-methicillin resistance by the AutoMicrobic system, 746 staphylococci from seven different geographical areas were tested. Results were compared with the Bauer-Kirby agar disk diffusion technique as the reference method. Of the 304 staphylococci, 209 coagulase-positive and 95 coagulase-negative strains were resistant to oxacillin-methicillin. These organisms fell into three categories of resistance detection. The first category had resistance levels high enough for initial detection, the second category had low resistance levels requiring modified data analysis techniques for detection, and the third category had resistance levels too low for detection. Of the resistant strains tested, 21% showed a category two resistant growth pattern. Major errors, as a result of hetero-resistant growth patterns of the tested strains, were resolved by computer analysis of growth curves. These data analysis applications enabled detection of 96% of the oxacillin-methicillin-resistant organisms. Results for all resistant staphylococci tested were available in an average time of 5.5 h.
Comparison of solid-phase immune electron microscopy by use of protein A with direct electron microscopy and enzyme-linked immunosorbent assay for detection of rotavirus in stool
Authors: Svensson L , Grandien M , Pettersson C A
Published: January 2020

A total of 525 stool specimens collected during 1 year were examined for the presence of rotavirus by direct electron microscopy (EM), enzyme-linked immunosorbent assay (ELISA), and a solid-phase immune electron microscope method (SPIEM) utilizing protein A-coated grids for anchoring of specific viral antisera. Rotavirus was seen in 187 specimens; SPIEM detected 183 (97.8%), whereas direct EM and ELISA detected 161 (86%) and 166 (88.7%), respectively. No false-positive reactions were seen by ELISA. The sensitivity of the methods was evaluated by coded investigation of a dilution series of a positive sample, with a negative fecal specimen as diluent. SPIEM was approximately 30 times more sensitive than direct EM and 10 times more sensitive than ELISA. A study was done to compare the elapsed time for recognition of rotavirus by SPIEM and EM in 25 randomly selected positive specimens. All virus-positive specimens were detected within 2 min by SPIEM, whereas up to 9 min was required for direct EM. SPIEM with protein A is a highly sensitive method, useful for rapid detection of viruses in clinical specimens. Due to the direct visualization of virus particles by electron microscopy, there is no requirement for monospecific antisera for the method.
Use of leukocyte esterase-nitrate activity as predictive assays of significant bacteriuria
Authors: Smalley D L , Dittmann A N
Published: January 2020

The present study evaluated the usefulness of the 1-min leukocyte esterase-nitrite tests in a tertiary-care hospital as a screening procedure to detect significant bacteriuria and correlated the findings with culture results. A total of 531 urine samples were reviewed, of which 484 were evaluated. Of the evaluated samples, 113 positive cultures (23.4%) were found, of which 93 (82.3%) were detected by leukocyte esterase-nitrite tests. In addition, 365 of 371 (98.4%) urine samples with negative bacterial cultures were negative in leukocyte esterase and nitrite tests.
Evaluation of Mueller-Hinton agar for disk diffusion susceptibility tests
Authors: Murray P R , Zeitinger J R
Published: January 2020

Twelve lots of commercially prepared Mueller-Hinton agar from four medium manufacturers were evaluated for performance with recommended quality control organisms, medium pH, agar depth and uniformity, and characteristics of the zones of inhibition. Only 2 of 12 lots were acceptable for disk diffusion susceptibility tests. Significant problems were observed with the preparation and pouring of the agar media.
Abbreviated scheme for presumptive identification of Staphylococcus saprophyticus from urine cultures
Authors: Morgan J W
Published: January 2020

A simplified scheme for the presumptive identification of Staphylococcus saprophyticus was investigated. Clinical isolates of Micrococcaceae were tested in microtiter plates containing phenol red-novobiocin-turanose broth and phenol red-arabinose broth. Standard saline suspensions of test organisms served as inoculum. Identifying features were growth within 18 to 24 h in novobiocin-turanose broth, indicating resistance to 1.6 micrograms of novobiocin per ml and fermentation of turanose. With this method, all clinical isolates of S. saprophyticus tested were correctly identified.
Rapid identification of enterococci
Authors: Bosley G S , Facklam R R , Grossman D
Published: January 2020

A 4-h method was devised to differentiate the non-beta-hemolytic streptococci into three categories: enterococci, group D nonenterococci, and viridans streptococci. All of the Streptococcus faecalis, 90% of the Streptococcus faecium (enterococci), and 96% of the Streptococcus bovis biotype I (group D nonenterococci) cultures were correctly identified by the 4-h method. The less commonly isolated group D cultures had lower rates of correct identification by this method. None of the viridans streptococci was identified incorrectly.
Vancomycin as a selective agent for isolation of Bacteroides species
Authors: van Winkelhoff A J , de Graaff J
Published: January 2020

Thirty saccharolytic and asaccharolytic black-pigmented Bacteroides strains were tested for their susceptibility to vancomycin. All asaccharolytic strains appeared to be partly or completely inhibited at a concentration of 7.5 micrograms/ml, whereas most saccharolytic strains were resistant to this concentration. The use of vancomycin in Bacteroides selective media is discussed.
Amylase inhibits Neisseria gonorrhoeae by degrading starch in the growth medium
Authors: Gregory M R , Gregory W W , Bruns D E , Zakowski J J
Published: January 2020

Highly purified salivary alpha-amylase inhibited the growth of fresh isolates of Neisseria gonorrhoeae on GC agar base medium supplemented with 2% IsoVitaleX (BBL Microbiology Systems). Hydrolysis of starch in the medium by amylase resulted in a negative starch-iodine test. However, purified amylase did not inhibit gonococcal growth on agar plates that contained hemoglobin (chocolate agar). This effect was not caused by inhibition of amylase, since amylase activity was the same in the presence or absence of blood products. Moreover, survival of N. gonorrhoeae in buffered saline was not affected by amylase. These results suggest that amylase inhibited the growth of N. gonorrhoeae on GC agar base plates by hydrolyzing starch.
Fluorescent-antibody reagents for the identification of Clostridium botulinum
Authors: Glasby C , Hatheway C L
Published: January 2020

Fluorescent-antibody reagents were prepared against vegetative cells of representative strains of each physiological group and toxin type of Clostridium botulinum known to have caused botulism in humans. A fluorescent-antibody reagent was also prepared for C. botulinum type G, which has been isolated from autopsy specimens but which has not clearly been implicated in botulism. These fluorescent-antibody reagents were evaluated against 200 strains of C. botulinum and 64 strains of other clostridia. Each reagent reacted with at least a 2+ intensity with all of the strains in its same toxin type and physiological group. Ninety-seven percent of the strains gave at least a 3+ reaction with the homologous group or toxin type reagent. Some cross-reactions occurred with reagents against different toxin type strains within a physiological group; there was less cross-reaction between physiological groups and very little reactivity of C. botulinum reagents with nontoxigenic organisms. Absorption of cross-reacting antibodies was not successful. Certain reagents could be used for presumptive laboratory identification of C. botulinum strains causing botulism, especially in infants. The type G reagent provided a good means of identifying C. botulinum type G, which lacks the lipase marker and whose toxigenicity may be more difficult to demonstrate in mixed cultures. There was a serological relationship between C. botulinum type G and some strains of Clostridium subterminale. This relationship provided evidence of differences between strains of C. botulinum type G isolated in two different countries.
Respiratory syncytial virus detection by immunofluorescence in nasal secretions with monoclonal antibodies against selected surface and internal proteins
Authors: Kim H W , Wyatt R G , Fernie B F , Brandt C D , Arrobio J O , Jeffries B C , Parrott R H
Published: January 2020

Specimens containing respiratory tract epithelial cells from infants and children with acute respiratory disease were evaluated by using an indirect immunofluorescence technique with two specific respiratory syncytial virus monoclonal antibodies. One (RS/HN 13-1) was directed against a cell surface viral antigen, and the other (RS/HN 25-2) was directed against viral antigen present in large cytoplasmic inclusions. The same results on presence or absence of respiratory syncytial virus were obtained by cell culture and immunofluorescence in 93% of 252 patients tested adequately by both methods. The sensitivity of indirect immunofluorescence was approximately equal to that of cell culture. A total of 84 specimens were positive for RSV by immunofluorescence; 82 of them were positive with both monoclones, and the remaining 2 were positive only with the monoclone directed against the internal protein. The fluorescence pattern of the latter monoclone was unique and easily recognized. Indirect immunofluorescence testing with monoclonal antibodies to respiratory syncytial virus proved to be a very useful diagnostic technique, and results could be obtained within 4 h of specimen collection.
Utilization of indole compounds by Cryptococcus neoformans to produce a melanin-like pigment
Authors: Kwon-Chung K J , Tom W K , Costa J L
Published: January 2020

Several indoles served as substrates for the phenoloxidase of Cryptococcus neoformans and resulted in the production of a melanin-like pigment. In general, a higher percentage of C. neoformans var. neoformans (A and D serotypes) isolates could produce pigment from indoles than could those of var. gattii (B and C serotypes). Only compounds with a hydroxyl or an amino group on the phenyl ring produced pigment; methoxy, nitro, methyl, and fluorine substituents on the phenyl ring were inactive, as was a hydroxyl group at the 2 position on the indole ring. The phenoloxidase of C. neoformans thus appears to differ from that found in Mycobacterium leprae, which cannot use a hydroxyindole, desoxyfructo-5-hydroxytryptamine, as a substrate. In addition, C. neoformans differs from M. leprae in that desoxyfructo-5-hydroxytryptamine does not inhibit the uptake of dihydroxyphenylalanine into the cell.
Rapid diagnosis of septic arthritis by coagglutination
Authors: Mayer M E , Geiseler P J , Harris B
Published: January 2020

Pneumococcal capsular antigens were detected and serotyped by coagglutination in joint fluids and serum of a patient with septic arthritis within 1 h of obtaining the specimens. Pneumococcal antigens continued to be detected by coagglutination for 3 days, whereas cultures and Gram stains were negative after 1 day of antibiotic therapy.
Application of serotyping and chromosomal restriction endonuclease digest analysis in investigating a laboratory-acquired case of Campylobacter jejuni enteritis
Authors: Penner J L , Hennessy J N , Mills S D , Bradbury W C
Published: January 2020

A frequently passaged laboratory strain of Campylobacter jejuni was confirmed by serotyping on the basis of thermostable antigens and by bacterial chromosomal restriction endonuclease digests to be the causative agent of enteritis in a laboratory worker.
Stability of antibiotics bound to polytetrafluoroethylene with cationic surfactants
Authors: Donetz A P , Harvey R A , Greco R S
Published: January 2020

This study evaluated the effect of prolonged storage and sterilization on the noncovalent bonding of penicillin to polytetrafluoroethylene grafts. The surfactant tridodecylmethylammonium chloride was unaffected by prolonged storage or sterilization, and its ability to bind penicillin remained constant for as long as 3 months. Steam or ethylene oxide sterilization markedly diminished the antibacterial activity of bound penicillin. However, the antibacterial properties of penicillin remained constant for up to 12 weeks when the grafts were stored at either 4 degrees C or room temperature. Thus, the bonding process appears to increase the stability of the antibiotic, and the data presented suggest that vascular prostheses can be treated with a surfactant, sterilized, and stored for at least 3 months. Grafts can then be treated with an antibiotic in the operating room, washed, and implanted.
Hemagglutination patterns of Aeromonas spp. in relation to biotype and source
Authors: Burke V , Cooper M , Robinson J , Gracey M , Lesmana M , Echeverria P , Janda J M
Published: January 2020

Aeromonas spp. show patterns of hemagglutination with human group O cells in the presence of fucose, galactose, and mannose. These patterns are related to biotype as well as to the source of isolates. There was good correlation between hemagglutination pattern and the presence of diarrhea among strains isolated in Western Australia, which was the only source with adequate data for classification of children with an without diarrhea. Most of the environmental and other nonfecal isolates produced patterns different from those in strains associated with diarrhea. These results suggest that hemagglutinins should be considered with enterotoxins as virulence factors in Aeromonas spp.