bluuebunny/crossref_metadata_2025 huggingface dataset:
Methods for optimal recovery of Malassezia furfur from blood culture
Authors: Marcon M J , Powell D A , Durrell D E
Published: January 2020

Malassezia furfur, a recently described agent of catheter-associated sepsis, requires long-chained fatty acids for in vitro growth. To determine optimum conditions for recovery of the organism from blood culture, we compared a radiometric (BACTEC) with a lysis centrifugation-direct agar plating (Isolator) blood culture method. When blood culture isolates of M. furfur were suspended in phosphate-buffered saline and used as inocula, the BACTEC system detected the organisms radiometrically only when bottles were supplemented with lipid compounds; detection was often delayed (greater than or equal to 72 h) when small inoculum sizes were tested. The Isolator pediatric tube system detected growth of M. furfur within 48 h of plating onto a lipid-supplemented agar medium. Simulated blood culture experiments showed that the addition of whole human blood and Intralipid to the BACTEC 6B bottle was associated with rapid lysis of erythrocytes, accumulation of a chocolate brown sediment in the bottles, and fungicidal activity to the M. furfur isolates. In contrast, suspensions of M. furfur in whole human blood were stable for at least 8 h in Isolator tubes and quantitatively recoverable after plating onto agar. Of the two systems studied, the Isolator tube system provided a more suitable procedure for isolation of M. furfur from blood culture.
Evaluation of laboratory tests for detection of methicillin-resistant Staphylococcus aureus and Staphylococcus epidermidis
Authors: Coudron P E , Jones D L , Dalton H P , Archer G L
Published: January 2020

Few studies evaluating susceptibility testing of methicillin-resistant staphylococci have included isolates of Staphylococcus epidermidis, a known pathogen in many types of serious infections. We tested 175 S. epidermidis and 95 Staphylococcus aureus isolates to determine the most sensitive procedures for detecting methicillin-resistant staphylococci. Reference procedures included agar dilution with methicillin and 4% NaCl in the agar and broth microdilution with methicillin and 2% NaCl in cation-supplemented Mueller-Hinton broth. After 24 h of incubation, the results from both methods correlated well and were within 1 log2 dilution for all isolates tested. Only one-half of all resistant isolates (92 of 183) were detected at 18 h by using the standard disk diffusion technique with 5-micrograms methicillin disks, and even fewer were detected with 10-micrograms methicillin disks and newly recommended zone-size criteria. However, the standard disk diffusion method with 4% NaCl in the agar increased the sensitivity and specificity for identification of the proper phenotype to greater than 92%. The spread plate and new spot techniques, both using agar with 4% NaCl, were also sensitive methods. Of 47 S. epidermidis isolates tested against oxacillin, 6 (13%) were oxacillin susceptible but methicillin resistant. Two automated systems, the Automicrobic system (Vitek Systems) and MicroScan (American MicroScan), as well as two broth screening systems available from Remel and Austin Biological Laboratories, failed to detect several resistant isolates, depending on the species.
Antibodies to staphylococcal enterotoxins and toxic shock syndrome toxin 1 in sera of patients and healthy people in Rio de Janeiro, Brazil
Authors: Solino Noleto A L , da Costa Cesar E , Bergdoll M S
Published: January 2020

Sera from 33 persons with staphylococcal infections and from 37 healthy persons were surveyed for the presence of antibody to staphylococcal enterotoxins A, B, C, D, and E and toxic shock syndrome toxin 1. Thirty-one (93.9%) of the patients and 35 (94.6%) of the control group had antibodies to one or more of the enterotoxins. The numbers of patients with antibody to the enterotoxins were as follows: A, 8; B, 9; C, 7; D, 17; E, 21; and toxic shock syndrome toxin 1, 11. The numbers of healthy individuals with antibody to the enterotoxins were as follows: A, 6; B, 12; C, 8; D, 27; E, 21; and toxic shock syndrome toxin 1, 9.
Isolation of Blastomyces dermatitidis from an earthen floor in southwestern Ontario, Canada
Authors: Bakerspigel A , Kane J , Schaus D
Published: January 2020

The first Canadian isolation of Blastomyces dermatitidis from nature is recorded. This was from the earthern floor of a petroleum filtering shed located in southwestern Ontario. A technician working in this environment became infected and was diagnosed as having systemic blastomycosis with meningeal involvement.
Rapid diagnosis of respiratory syncytial virus infection by antigen immunofluorescence detection with monoclonal antibodies and immunoglobulin M immunofluorescence test
Authors: Kadi Z , Dali S , Bakouri S , Bouguermouh A
Published: January 2020

During a respiratory syncytial virus (RSV) infection outbreak in a pediatric hospital, diagnosis was made by immunofluorescence on smears by using an anti-RSV monoclonal antibody (IFm). Immunoglobulins M and G were titrated by indirect immunofluorescence on HEp-2 cells infected with an RSV strain. The IFm was sensitive (89%) and specific (75%) when compared with the cell culture method. We showed that the specimens which were found positive by IFm and negative by cell culture were truly positive. Under these conditions, the IFm test appears more sensitive and more specific than cell culture, particularly when no care is taken to maintain the specimens in the cold during transport. In this study the immunoglobulin M immunofluorescence test had a low sensitivity (34%), especially on serum samples taken on days 0 to 4 after the onset of illness.
Homotypic and heterotypic antibodies for prevention of experimental rotavirus gastroenteritis
Authors: Losonsky G A , Vonderfecht S L , Eiden J , Wee S B , Yolken R H
Published: January 2020

We investigated the abilities of homologous and heterologous antibody preparations to neutralize murine rotavirus in a mouse model of rotavirus infection. We found that incubation of virus with murine sera obtained from animals experimentally infected with the homologous epizootic diarrhea of infant mice strain of rotavirus resulted in inability of the virus to cause symptomatic disease in infant mice. Sera from nonimmune mice and mice infected or immunized with a heterotypic strain of rotavirus did not effectively neutralize virus in this system. On the other hand, neutralization was noted after incubation of virus with a number of immunoglobulins from other animal and human sources. The neutralizing activity of the preparations in the murine model correlated partially, but not completely, with the level of in vitro neutralizing antibody to the murine strain of rotavirus measured in a tissue culture system. In most cases, asymptomatic infection after feeding of the virus and the antibody preparation resulted in subsequent generation of an active immune response in infected animals.
Identification of phase-specific antigenic fractions of Coxiella burnetti by enzyme-linked immunosorbent assay
Authors: Williams J C , Thomas L A , Peacock M G
Published: January 2020

Antigenic fractions of Coxiella burnetii phase variants were identified with an enzyme-linked immunosorbent assay (ELISA). Immune sera from guinea pigs immunized with Formalin-inactivated phase I or phase II whole cells were used to measure the antigenic activity of whole cells and various soluble and particulate preparations. Phase-specific antigens of C. burnetii whole cells and fractions were compared by dose-response curves at different (antigen and antibody) dilutions. Water-soluble extracts prepared by meta-periodate, ether, and phenol extraction of phase I whole cells yielded antigenic fractions which reacted with anti-phase I antibodies. The extraction of phase I whole cells with dimethyl sulfoxide, trichloracetic acid, and Formalin yielded antigenic fractions which detected antibodies in both anti-phase I and -phase II sera. Interestingly, the trichloracetic acid extract of phase I whole cells also contained a component which bound nonimmune immunoglobulin. The sera of animals immunized with whole cells of the phase II Australian QD strain reacted with lipopolysaccharides of the phase I and phase II Nine Mile strains. Therefore, variations in lipopolysaccharide structure among phase variants of C. burnetii were detected as cross-reactions with immune sera from an interspecific strain. Comparisons of immunofluorescence, microagglutination, and the complement fixation assays with the ELISA indicated greater sensitivity and specificity of the ELISA for the measurement of phase-specific antigens and antibodies.
Elastolytic activity among staphylococci
Authors: Janda J M
Published: January 2020

A total of 161 isolates of the genus Staphylococcus were evaluated for the ability to produce elastase. Elastase activity was detected only in S. epidermidis strains (sensu stricto), being absent in S. aureus isolates and other coagulase-negative staphylococci tested. The elastase elaborated by S. epidermidis isolates appeared to be an inducible enzyme whose synthesis was medium dependent.
Enzyme-linked immunosorbent assay to detect Shiga toxin of Shigella dysenteriae and related toxins
Authors: Kongmuang U , Honda T , Miwatani T
Published: January 2020

A sandwich enzyme-linked immunosorbent assay (ELISA) was developed for detection of Shiga toxin. Four species of Shigella, Escherichia coli, and Vibro parahaemolyticus were tested for production of Shiga or Shiga-like toxin by ELISA and Vero cell bioassay. In the ELISA, most strains of S. dysenteriae and some strains of E. coli isolated from traveler's diarrhea were positive. These ELISA-positive strains were positive by Vero cell bioassay without exception. Some E. coli strains and most V. parahaemolyticus strains were toxic to Vero cells, although they were negative in the ELISA. Much of the cytotoxic activity was not neutralized by anti-Shiga toxin antiserum. The newly developed sandwich ELISA is specific and can be a substitute for the cumbersome Vero cell bioassay.
Antibody response to teichoic acid and peptidoglycan in Staphylococcus aureus osteomyelitis
Authors: Jacob E , Durham L C , Falk M C , Williams T J , Wheat L J
Published: January 2020

An enzyme-linked immunosorbent assay was used to evaluate the immunoglobulin G (IgG) response to Staphylococcus aureus crude teichoic acid (TA) and peptidoglycan (PG) in both rabbits and patients with osteomyelitis. In rabbits with experimental S. aureus osteomyelitis, elevated levels of IgG to TA were present in 13/18 (72%) of the serum samples obtained at 4 and 10 weeks postinfection. In contrast, only 5/18 (28%) of these sera were found to be positive for antibodies to PG. Of a total of 39 patients with confirmed S. aureus osteomyelitis (11 acute, 28 chronic), IgG to TA was elevated in 17 (44%), whereas antibodies to PG were found to be increased in only 1 (3%). Cross-reacting antibodies to S. aureus TA were detected in only 1/18 (6%) of the patients with osteomyelitis caused by organisms other than S. aureus. These studies indicate that IgG to TA is more prevalent than IgG to PG in patients with staphylococcal osteomyelitis. Although these results are encouraging, a larger number of patients is required for an adequate evaluation of the TA enzyme-linked immunosorbent assay for the diagnosis and management of suspected S. aureus osteomyelitis.
Enzyme-linked immunosorbent assay for Potomac horse fever disease
Authors: Pretzman C I , Rikihisa Y , Ralph D , Gordon J C , Bech-Nielsen S
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) and IgM in natural and experimental infections of equids with Ehrlichia risticii was developed. Ehrlichial organisms purified from an infected mouse macrophage cell line were used as the antigen. IgM was separated from serum IgG by the expedient of spun-column chromatography, allowing the use of an indirect ELISA for quantitation of both IgG and IgM in the test sera. Among 16 paired sera from horses exhibiting clinical signs of Potomac horse fever, 8 were positive by the indirect fluorescent-antibody test (IFA), 11 were positive by the IgG ELISA, and 8 were positive by the IgM ELISA. All IFA-positive specimens were positive by the IgG ELISA, which appeared to be more sensitive than the IFA. In all cases, the IgG ELISA alone would have sufficed for diagnosis when acute- and convalescent-phase sera were available. When 26 single acute- or convalescent-phase serum samples were tested, the IFA detected 8, the IgG ELISA detected 10, and the IgM ELISA detected 6 positive serum specimens. The kinetics of IgG and IgM responses as determined by ELISA in two experimentally infected ponies which survived infection and challenges revealed that specific IgM was short-lived, falling to undetectable levels by day 60 postinoculation, whereas specific IgG persisted for more than 1 year. IgM and IgG were detected as early as days 1 and 10, respectively, postinoculation. The results suggest that the ELISA is more sensitive than the IFA and that the IgM ELISA may provide a means for early diagnosis of Potomac horse fever at or before the onset of clinical signs.
Micromethod for assaying reverse transcriptase of human T-cell lymphotropic virus type III/lymphadenopathy-associated virus
Authors: Spira T J , Bozeman L H , Holman R C , Warfield D T , Phillips S K , Feorino P M
Published: January 2020

A micromethod for assaying the reverse transcriptase enzyme of human T-cell lymphotropic virus type III/lymphadenopathy-associated virus in cocultures of clinical specimens for viral isolation was developed and compared with the macromethod in use. Ultracentrifuged, pelleted, and solubilized viral culture supernatants were transferred into either tubes (macromethod) or microtiter plates (micromethod) and incubated with tritiated enzyme substrate. Trichloroacetic acid-precipitated DNA was collected on individual filter papers with a Millipore filtration manifold (macromethod) or on filter sheets using a semiautomated cell harvester (micromethod). Filters were then placed in scintillation fluid and counted on a beta scintillation counter. Results of the micromethod significantly correlated to those of the macromethod, with a linear relationship between the two. The cutoffs for positivity based on the mean + 2 standard deviations for a set of known negative specimens (n = 19) was 4,973 cpm for the micromethod compared with 5,336 for the macromethod. The intrarun and interrun variations were comparable for both methods. There was a 67% increase in the maximal daily number of specimens which could be run (100 versus 60) as well as a reduction in reagent use. In summary, the micromethod utilizing a semiautomated cell harvester is comparable to the existing macromethod in accuracy and is an improvement due to savings in time and reagents.
Comparison of physiologic tests used to identify non-beta-hemolytic aerococci, enterococci, and streptococci
Authors: Fertally S S , Facklam R
Published: January 2020

Twenty-one reference strains and 88 clinical isolates of Aerococcus, Enterococcus, and Streptococcus species were tested for reactions in the Rapid Strep (RS) and modified conventional tests. We conclude that some but not all of the tests in the RS system could be used to substitute for conventional tests. RS tests for hydrolysis of arginine, esculin, L-pyrrolidonyl-naphthylamide, production of acetyl methyl carbinol (Voges-Proskauer), and fermentation of arabinose, lactose, mannitol, raffinose, and sorbitol were satisfactory substitutes for conventional tests. However, the RS tests for hydrolysis of hippurate and starch and fermentation of inulin were not satisfactory substitutes for conventional tests. We also conclude that, of the five test tube Voges-Proskauer tests, the Coblentz modification is the most discriminatory.
DNA hybridization for diagnosis of enteric adenovirus infection from directly spotted human fecal specimens
Authors: Hammond G , Hannan C , Yeh T , Fischer K , Mauthe G , Straus S E
Published: January 2020

By using a genomic probe, DNA hybridization for adenovirus type 41 (Ad41) showed equivalent sensitivity with a direct spot method from clinical specimens compared with a more laborious DNA phenol extraction procedure. By using this direct spot preparation method, fecal specimens of 67 patients were examined under code for blind testing for the presence of adenovirus by DNA hybridization by using two Ad41 probes (genomic and cloned BglII-D) and an adenovirus type 2 genomic probe. Identical results were obtained with both of the Ad41 probes. Of the fecal specimens from 42 children with adenovirus gastroenteritis studied prospectively (16 of whom had enteric adenoviruses), 13 specimens (81%) were detected by DNA hybridization with a cloned Ad41 BglII-D probe. There were 14 fecal specimens that were positive by electron microscopy (EM) and culture for nonenteric adenovirus, and 2 specimens were positive by DNA hybridization (87% specificity); these 2 specimens may have been from a mixed enteric adenovirus and nonenteric adenovirus infection. None of 26 specimens from age-matched healthy control patients was positive for adenovirus by EM or DNA hybridization. Our data indicated that DNA hybridization gives highly reproducible results. The direct spot technique is the method of choice for specimen preparation in the diagnostic laboratory, since it requires only the simplest manipulations in specimen preparation. By using DNA hybridization with the BglII D fragment of a cloned enteric Ad41, both adenovirus type 40 and Ad41 were detected directly from fecal specimens, but it was less sensitive than EM following direct ultracentrifugation of specimens. The Bg1II-D Ad41 DNA probe was highly specific for enteric adenoviruses, and DNA hybridization with this probe could be a useful diagnostic test for these fastidious adenoviruses.
Electron microscopy procedure influences detection of rotaviruses
Authors: Nakata S , Petrie B L , Calomeni E P , Estes M K
Published: January 2020

Technical parameters of electron microscope staining procedures (type of stain, pH of stain, and time of staining) influence particle integrity for three groups of rotaviruses. Simian rotavirus SA11 (group A), Chinese adult diarrhea rotavirus and porcine rotavirus-like agent (group B), and porcine pararotavirus (group C) were tested. All rotavirus strains were quite stable in uranyl acetate and phosphotungstic acid at pH 4.5 and relatively stable in ammonium molybdate. However, staining with phosphotungstic acid at higher pH values with increased staining time yielded a reduction in the number of particles and particles that were broken or degraded to single-shelled particles or core particles. The different staining procedures were also tested in immunoelectron microscopy experiments. Antibody molecules bound to rotavirus particles were observed clearly only with phosphotungstic acid staining and not with uranyl acetate. We therefore recommend that uranyl acetate and phosphotungstic acid at pH 4.5 be used for negative staining of rotaviruses; phosphotungstic acid at pH 4.5 is optimal for immunoelectron microscopy. These technical points may be critical for rotavirus detection and are important for studies pertaining to the epidemiology and clinical importance of the non-group A rotaviruses.
Predominance of capsular polysaccharide type 5 among oxacillin-resistant Staphylococcus aureus
Authors: Fournier J M , Bouvet A , Boutonnier A , Audurier A , Goldstein F , Pierre J , Bure A , Lebrun L , Hochkeppel H K
Published: January 2020

The relationship between capsular polysaccharide types 5 and 8 and resistance of Staphylococcus aureus to oxacillin was studied with a collection of 406 clinical isolates from six French hospitals. Of 175 type 5 isolates, 84 (48%) were resistant to oxacillin. In contrast, only 8 of 160 type 8 isolates (5%) and 5 of 71 nontypeable isolates (7%) were resistant to oxacillin. Therefore, capsular typing of clinical isolates of S. aureus may facilitate the choice of first-line antibiotic therapy.
Problems in detection of cytomegalovirus in urine samples by dot blot hybridization
Authors: Augustin S , Popow-Kraupp T , Heinz F X , Kunz C
Published: January 2020

A hybridization assay for the detection of cytomegalovirus (CMV) in urine specimens was established. Two different DNA fragments were used as hybridization probes: the HindIII L fragment (11.7 kilobases) and the EcoRI J fragment (10.6 kilobases) of the human CMV strain AD169. These probes were used in an isolated and highly purified form and therefore did not cross hybridize with vector sequences. As shown by hybridization with DNA from CMV-infected and uninfected cells, the assay was highly CMV specific and sensitive (detection limit, 750 to 500 fg of CMV DNA). A total of 122 urine specimens were examined by DNA hybridization, virus isolation, and the detection of CMV-induced early nuclear protein. The results coincided in 91% of the samples. The application of DNA hybridization to urine samples, however, is not without problems, and some of the pitfalls and drawbacks are discussed.
Enhanced method of herpes simplex virus culture confirmation using the virogen herpes slide test
Authors: Prymas L A , Venezia R A , McSharry M M
Published: January 2020

Of 100 herpes simplex virus specimens, 30% were detected by the Virogen Herpes Slide test at the initial observation of cytopathic effect (CPE) on MRC-5 cells. The remainder became positive after the CPE had progressed. Enhancement of the test procedure was accomplished by vortexing the infected cells to disrupt the monolayer, and the time to positivity became equivalent to the initial time of CPE. Compared with a fluorescent-antibody technique, the Virogen Herpes Slide test was 100% sensitive and specific when used for culture confirmation of herpes simplex virus.
Effect of decontamination procedures on recovery of Nocardia spp
Authors: Murray P R , Heeren R L , Niles A C
Published: January 2020

Exposure to 0.5% N-acetyl-L-cysteine (NAC), 2% NaOH-NAC, or benzalkonium chloride in trisodium phosphate (Zephiran-TSP) was toxic for Nocardia isolates. The number of viable Nocardia cells in a standardized suspension was reduced by 10(2) to 10(6) after a 30-min exposure to 2% NaOH-NAC and by 10(4) or more after a 30-min treatment with Zephiran-TSP.
Purified 60-kilodalton Legionella protein antigen with Legionella-specific and nonspecific epitopes
Authors: Plikaytis B B , Carlone G M , Pau C P , Wilkinson H W
Published: January 2020

In a previous study, all convalescent-phase sera from patients with culture-confirmed legionellosis reacted on immunoblots with a Legionella genus-wide 58-kilodalton (kDa) protein antigen (J.S. Sampson, B.B. Plikaytis, and H.W. Wilkinson, J. Clin. Microbiol. 23:92-99, 1986). The present study was done to immunologically characterize and determine the diagnostic relevance of this purified antigen. The antigen was precipitated from enriched cell extracts with ammonium sulfate and purified by high-pressure liquid chromatography. High-titered rabbit antiserum produced to the purified protein was used to show its presence on immunoblots in the 60-kDa range in 38 Legionella serogroups, representing 23 species, and in 39 non-Legionella bacteria. The antiserum was made specific for Legionella strains by sequential absorptions with Bordetella pertussis, Pseudomonas aeruginosa, and Pseudomonas fluorescens whole cells. Serum from legionellosis patients reacted with both specific and nonspecific epitopes. Results of indirect immunofluorescence experiments showed that neither specific nor nonspecific epitopes of the 60-kDa protein were surface exposed on Legionella cells and that cross-reactive epitopes were variably exposed on non-Legionella bacteria. The 60-kDa protein antigen should be useful in diagnostic tests for legionellosis if care is taken to expose cryptic epitopes and if the tests use or measure only the Legionella-specific epitopes.
Efficacy of enzyme-linked immunosorbent assay for rapid diagnosis of Bordetella pertussis infection
Authors: Lawrence A J , Paton J C
Published: January 2020

We examined the diagnostic efficacy of an enzyme-linked immunosorbent assay (ELISA) for class-specific antibodies to Bordetella pertussis in acute-phase sera collected from 1,240 patients with suspected pertussis. A total of 833 serum specimens (67%) yielded positive results. The proportion of positive results increased to 77% if a second (convalescent-phase) serum was also tested. By comparison, a bacterial agglutination test for B. pertussis antibodies was positive in only 21% of acute-phase specimens and 50% of paired specimens. The high proportion of acute-phase sera which were ELISA positive indicates that a measurable serologic response has usually occurred by the time the diagnosis is suspected. Thus, the ELISA is potentially the most rapid means of laboratory confirmation of B. pertussis infection.
Spheroplast induction in clinical isolates of Serratia marcescens in the presence of Ca2+ or Mg2+
Authors: Tada Y , Yamaguchi J
Published: January 2020

Serratia marcescens was easily induced to form spheroplasts by beta-lactam antibiotics in the presence of Ca2+ or Mg2+ without an osmotic stabilizer such as sucrose. The spheroplasts grew in volume, although they could not divide. They were stable for more than 10 h at 37 degrees C in a medium containing a high concentration of antibiotic, and they had the ability to revert to the original bacillary form. Ca2+ was more effective in spheroplast induction than Mg2+. The effect was proportional to the concentration of cations. In 40% of 180 clinical isolates of S. marcescens, more than 40% of the original bacterial cells were induced to form spheroplasts by ceftizoxime in a medium supplemented with 40 mM Ca2+. A high spheroplast induction rate was observed even in medium with 10 mM Ca2+. Few isolates that were supersusceptible to ceftizoxime (MIC, less than 0.2 microgram/ml) were induced to form spheroplasts at a high rate. No difference in spheroplast induction rate or extent between antibiotic-resistant strains and relatively susceptible strains (MIC, greater than 0.2 microgram/ml) was found. The serotype of S. marcescens had no effect on the spheroplast induction rate. Monocations (Na+ and K+) had little effect on spheroplast induction.
Three rapid methods compared with a conventional method for detection of urease production in anaerobic bacteria
Authors: Mills C K , Grimes B Y , Gherna R L
Published: January 2020

Three rapid methods (spot test, disk, and tube) for detecting urease production in anaerobic bacteria yielded results faster than the conventional method. The results were more consistent with the disk and tube methods than with the spot test. Blood agar plate growth gave more consistent results than growth from chopped-meat slants.
Rapid lysis technique for mycobacterial species
Authors: Hurley S S , Splitter G A , Welch R A
Published: January 2020

The lysis of mycobacterial cells typically has been difficult and time-consuming. We report a method for the physical rupture of Mycobacterium paratuberculosis and several other members of the family Mycobacteriaceae using a Mini-Beadbeater cell disrupter (Biospec Products; Bartlesville, Okla.) and zirconium beads, a process which yields DNA and RNA of high molecular weight and in greater quantity than that obtained by rupture in a Ribi pressure cell.
Evaluation of commercial serodiagnostic kits for toxoplasmosis
Authors: Wilson M , Ware D A , Walls K W
Published: January 2020

To evaluate commercially available diagnostic kits for human immunoglobulin G to Toxoplasma gondii, we purchased three enzyme immunoassay (EIA) (Cordia-T, Toxo Bio-EnzaBead, and Toxoelisa), two indirect hemagglutination (IHA) (TPM-Test and ToxHAtest), one fluoroimmunoassay (Toxoplasma-G FIAX), and one latex agglutination (Eiken Toxotest-MT) kit from U.S. suppliers. A total of 100 serum specimens, including 27 that were negative (less than 1:16) and 73 that were positive for the various titers in the Toxoplasma indirect immunofluorescence (IIF) test, were tested once with each kit; serum samples with discrepant results were retested. Qualitatively, results obtained with the Toxo Bio-EnzaBead EIA, the TMP-Test IHA, and FIAX, and the Toxotest-MT latex agglutination kits agreed exactly with those of IIF. Although all IIF-positive serum samples were detected by the Cordia-T and the Toxoelisa EIAs, four samples determined to be negative by IIF were identified as positive with the Cordia-T kit, and six negative samples by IIF were determined to be positive with the Toxoelisa kit. Results of the ToxoHAtest IHA kit were extremely difficult to read. Quantitatively, the seven kits were difficult to compare because the expression of results was not standardized. Of the four kits that gave positive results in titers, Toxoplasma-G FIAX had the closest agreement with IIF, as determined by the Spearman rank correlation coefficient (0.9168), followed by the Eiken Toxotest-MT (0.8293), the Toxo Bio-EnzaBead (0.7553), and the TPM-Test (0.7206) kits.
Randomized trial interpreting sputum quality in a clinical laboratory
Authors: Mizrachi H H , Valenstein P N
Published: January 2020

The role for laboratory interpretation of microbiologic results remains controversial, and many laboratories leave the interpretation of culture results entirely to physicians. We examined the effects of furnishing a laboratory interpretation of sputum quality on physician decision making. Quality of sputum was determined on Gram-stained smears by using a modification of the criteria of Bartlett (R. C. Bartlett, Medical Microbiology: Quality, Cost, and Clinical Relevance, p. 24-31, 1974). A total of 301 poor-quality specimens were randomized either to receive written interpretation of Gram stain results or to a control group for which Gram stain results were reported without interpretation. Physicians were more likely to follow up a poor-quality specimen with a second specimen if they had been furnished an interpretation of the results from the original Gram stain (22 versus 12%; P = 0.025). We conclude that laboratory-based interpretation of microbiologic results can improve physician decision making.
Molecular epidemiology of rotavirus in black infants in South Africa
Authors: Steele A D , Alexander J J
Published: January 2020

The molecular epidemiology of rotavirus infections in black infants in Ga-Rankuwa, South Africa, was investigated by polyacrylamide gel electrophoresis. Between 1983 and 1986, 14 different RNA electrophoretic patterns were observed for children with acute gastroenteritis. These electrophoretypes showed a sequential pattern of appearance, with a limited number being present at any one time. In contrast, for neonates only one RNA electrophoretype was detected, which persisted for at least 3 years.
First report of subcutaneous phaeohyphomycosis of the foot caused by Phoma minutella
Authors: Baker J G , Salkin I F , Forgacs P , Haines J H , Kemna M E
Published: January 2020

Phoma minutella, a dematiaceous hyphomycete, was isolated to the exclusion of all other fungi from a subcutaneous inflammatory process on the foot of a farmer undergoing corticosteroid therapy for myasthenia gravis. Isolation was achieved on several nutrient media. Examination of stained smears and sections revealed dematiaceous fungal elements consistent with the mold. This is the first reported association of P. minutella with a human infection and only the second reported case involving a Phoma sp. as the etiologic agent of a subcutaneous infection.
Septicemia caused by Propionibacterium granulosum in a compromised patient
Authors: Branger C , Bruneau B , Goullet P
Published: January 2020

A case of septicemia caused by Propionibacterium granulosum in a compromised patient is described. The patient responded to ampicillin therapy. Detailed antibiotic susceptibility data are presented.
Rapid, sensitive, competitive serologic enzyme-linked immunosorbent assay for detecting serum antibodies to bovine herpesvirus type 1
Authors: Riegel C A , Ayers V K , Collins J K
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) for the detection of cattle antibodies to bovine herpesvirus type 1 was developed on the basis of competition between serum antibody and a virus-neutralizing mouse monoclonal antibody. The assay showed improved sensitivity over the virus neutralization (VN) test and over an enhanced VN test in which incubation of antibody-virus mixtures was carried out for 24 h. With the ELISA, antibodies in sera from experimentally infected cattle were detected earlier after infection and showed more rapid increases in levels. A comparison of the ELISA with the VN tests by using a set of 85 field sera with low levels of antibodies demonstrated that the ELISA was the most sensitive test, detecting 10 positive serum samples that were negative by the VN tests. The ELISA was inexpensive, rapid, and highly reproducible and showed a significant improvement in sensitivity over VN tests.
API QuadFERM+ with rapid DNase for identification of Neisseria spp. and Branhamella catarrhalis
Authors: Janda W M , Zigler K L , Bradna J J
Published: January 2020

The QuadFERM+ system (Analytab Products, Plainview, N.Y.), a 2-h carbohydrate degradation method for the identification of Neisseria spp., was evaluated along with a rapid DNase test for confirmation of Branhamella catarrhalis. QuadFERM+ identified 100% of 82 N. gonorrhoeae and 96% of 54 N. meningitidis strains. The two misidentified meningococcal strains were biochemically atypical and were also misidentified by the conventional method. Of 26 N. lactamica strains, 25 (96%) were correctly identified. Of 21 Neisseria spp., 14 (67%) produced carbohydrate reactions in agreement with the conventional procedure, and 7 strains produced detectable acid in the QuadFERM+ from maltose and sucrose but not glucose. All 9 N. cinerea and 30 B. catarrhalis strains were asaccharolytic by QuadFERM+. The rapid DNase test was positive for all B. catarrhalis strains and negative for all other organisms. Two beta-lactamase-positive N. gonorrhoeae strains and 25 (93%) of 27 beta-lactamase-positive B. catarrhalis strains were detected by the 2-h acidometric beta-lactamase test on the strip. QuadFERM+ with rapid DNase is a simple and easily interpretable method for identification of these organisms in the clinical laboratory.
Diagnosis of herpes simplex virus by direct immunofluorescence and viral isolation from samples of external genital lesions in a high-prevalence population
Authors: Lafferty W E , Krofft S , Remington M , Giddings R , Winter C , Cent A , Corey L
Published: January 2020

One hundred thirty specimens from 108 consecutive patients with a history of recurrent genital ulcerations were used in a study comparing herpes simplex virus (HSV) isolation with a direct fluorescent-antibody (DFA) technique using mouse monoclonal antibodies. HSV was isolated from 70% of vesicular lesions, 67% of pustular lesions, 32% of ulcerative lesions, and 17% of crusted lesions, whereas the DFA technique detected HSV antigen in 87, 67, 30, and 10% of lesions in similar stages, respectively. When both methods were used, HSV was identified in 97, 79, 45, and 17% of vesicles, pustules, ulcers, and crusted lesions, respectively. The overall sensitivity and specificity of the DFA technique in comparison with virus isolation (VI) were 74 and 85%, respectively. Of the 17 patients from whom DFA-positive, VI-negative samples were obtained, HSV was subsequently isolated from a genital lesion in 14, suggesting that they were not DFA false-positives. Similarly, of the 46 patients whose initial lesion samples were DFA and VI negative, 37 (80%) had HSV identified from subsequent genital lesions during follow-up. Thus, a single sample for VI or DFA testing from a recurrent genital lesion had a sensitivity of only 53 and 51%, respectively. Combining the DFA technique and VI increased the sensitivity of laboratory diagnosis of a single recurrent episode of genital HSV; however, repetitive laboratory testing was often required to confirm the diagnosis of recurrent genital HSV infection.
Qualitative and quantitative determination of enterobacterial common antigen (ECA) with monoclonal antibodies: expression of ECA by two Actinobacillus species
Authors: Böttger E C , Jürs M , Barrett T , Wachsmuth K , Metzger S , Bitter-Suermann D
Published: January 2020

The presence and quantity of the enterobacterial common antigen (ECA) in several species belonging to the family Enterobacteriaceae as well as to other gram-negative families were determined by a solid-phase enzyme-linked immunosorbent assay system and Western blotting by using mouse monoclonal antibodies specific for ECA. Except for Erwinia chrysanthemi, previously known to be an exception, all species known or presumed to belong to Enterobacteriaceae produced ECA (89 of 90 species). Most species not belonging to Enterobacteriaceae did not produce ECA (25 of 28 species), with one already known (Plesiomonas shigelloides) and two hitherto unknown (Actinobacillus equuli and Actinobacillus suis) exceptions. Interestingly, all strains of P. shigelloides produced ECA, regardless of the presence of the Shigella sonnei cross-reacting O antigen. Quantitation of the amount of ECA in members of the family Enterobacteriaceae revealed a remarkable heterogeneity among genera and species as well as within one species. We conclude that the rapid, sensitive, and reliable determination of ECA is a useful aid in taxonomic classification and may help to characterize the relatedness of the family Enterobacteriaceae to other families. However, a quantitative analysis of ECA appears to be without value for these purposes.
Binding to galactose alpha 1----4galactose beta-containing receptors as potential diagnostic tool in urinary tract infection
Authors: Enerbäck S , Larsson A C , Leffler H , Lundell A , de Man P , Nilsson B , Svanborg-Edén C
Published: January 2020

The diagnosis of urinary tract infection is based largely on quantitative urine cultures. The usefulness of qualitative information about the virulence of the infecting bacteria remains undefined. Ability to attach to human uroepithelial cells is one characteristic of the pyelonephritogenic clones, as well as a virulence factor per se. The identification of host cell receptors for attaching bacteria has permitted the construction of agglutination tests for simple detection of bacterial binding properties. In the present study, the reactivity with Gal alpha 1----4Gal beta-latex [galactose alpha (1----4)galactose beta-latex] and globotetraosylceramide-latex was analyzed for strains from patients with acute pyelonephritis (n = 135), acute cystitis (n = 121), and asymptomatic bacteriuria (n = 119) and from the fecal flora of healthy children (n = 120) and compared with agglutination of human blood group P1 and p, as well as guinea pig, erythrocytes. The reactivity by bioassay and the receptor-specific assays were significantly correlated. The frequency of positive reactions among the pyelonephritis isolates was 78.5% with the globotetraosylceramide-latex reagent, compared with 41% for the cystitis isolates, 25% for the asymptomatic bacteriuria isolates, and 13% for the fecal isolates. The combination of bioassays and receptor-specific assays increased the resolution of adhesins. Thus, adhesins reacting with human p erythrocytes frequently were coexpressed with Gal alpha 1----4Gal beta-specific adhesins. The receptor-specific assays provide a refined reagent to resolve bacterial binding specificities, as well as a potential tool for clinical diagnosis.
Enzyme immunofiltration staining assay for immediate diagnosis of herpes simplex virus and varicella-zoster virus directly from clinical specimens
Authors: Cleveland P H , Richman D D
Published: January 2020

A simple, sensitive, 30-min assay for the detection of herpes simplex virus (HSV) and varicella-zoster virus (VZV) antigens in clinical specimens is described. The assay utilizes a filter manifold, biotinylated monoclonal antibodies, streptavidin-horseradish peroxidase conjugate, and the substrate aminoethylcarbazole. The method stains infected cells and cell debris a bright red and is easily interpreted with a dissecting microscope. Reconstruction experiments indicated that as few as two virus-infected cells per swab could be detected. This was equivalent to an infectivity titer of 29 to 160 50% tissue culture infective doses per infected cell and 250 times more sensitive than an enzyme immunofiltration assay which detects a soluble reaction product. Clinical swab specimens collected from ocular, oral, skin, and genital lesions were cultured for virus, and the remaining cell debris was immobilized on glass fiber filters and stained for the presence of virus antigens. Of 71 HSV culture-positive specimens, 66 (93%) were positive for HSV antigens. All of nine VZV culture-positive specimens were positive for VZV antigens. Of 98 culture-negative specimens, 7 were positive for either HSV (n = 3) or VZV (n = 4) antigens.
Comparison of indirect immunofluorescence and Western blot for detection of anti-human immunodeficiency virus antibodies
Authors: Carlson J R , Yee J , Hinrichs S H , Bryant M L , Gardner M B , Pedersen N C
Published: January 2020

There was 100% agreement between the results of indirect immunofluorescence (IF) and Western blot testing when these methods were used to detect antibodies to the human immunodeficiency virus in sera from 25 patients with acquired immune deficiency syndrome (AIDS), 20 patients with AIDS-related complex, 186 subjects at high risk for AIDS, and 40 healthy heterosexuals. However, there was only an 88.7% correlation between IF and Western blot results for 728 sera from blood and plasma donor centers that were selected on the basis of screening enzyme immunoassay reactivity. IF tests yielded nine false-negatives and were equivocal, yielding a nonspecific pattern of reactivity for both infected and uninfected cells for 73 of these specimens. The IF and Western blot methods were equal in performance for the detection of anti-human immunodeficiency virus antibodies in the high-risk and unselected low-risk groups, proving to be a practical approach for testing specimens from these subjects. However, the Western blot was the most acceptable method for the validation of specimens from groups at low risk for AIDS that were selected based on enzyme immunoassay reactivity.
Analysis of immunoglobulin G antibody responses after administration of live and inactivated influenza A vaccine indicates that nasal wash immunoglobulin G is a transudate from serum
Authors: Wagner D K , Clements M L , Reimer C B , Snyder M , Nelson D L , Murphy B R
Published: January 2020

Following intranasal administration of live influenza A virus vaccine or parenteral inoculation of inactivated influenza virus vaccine, immunoglobulin antibody to the influenza virus hemagglutinin was detected in nasal wash specimens from adult volunteers. Several observations supported the suggestion that this immunoglobulin G hemagglutinin nasal wash antibody appeared to be mainly derived from the serum by a process of passive transudation.
Molecular probe for identification of medically important Candida species and Torulopsis glabrata
Authors: Mason M M , Lasker B A , Riggsby W S
Published: January 2020

A cloned DNA fragment from Candida albicans containing the gene for the protein actin was used to probe the molecular structure of the actin gene of several medically important yeasts (C. albicans, Candida stellatoidea, Candida tropicalis, Candida pseudotropicalis, Candida krusei, Candida parapsilosis, Candida guilliermondii, and Torulopsis glabrata). Whole-cell DNA from each species was digested with restriction endonucleases, electrophoresed on agarose gels, and transferred to nitrocellulose. Radioactively labeled C. albicans actin gene was hybridized to the DNA fragments on the nitrocellulose. The C. albicans probe produced a strong signal with all of the Candida DNAs tested, indicating considerable conservation of this gene. In addition, the actin genes of all of the species tested were found to have no internal EcoRI or SalI restriction sites. With the exception of C. guilliermondii, all of the species tested had a single internal HindIII recognition site. However, the location of flanking restriction sites was found to be species specific. For all of the enzymes tested, the locations of the flanking restriction sites in C. albicans and C. stellatoidea were identical; all of the other strains yielded fragments clearly distinct from one another. These differences provide a molecular tool for the differentiation of medically important Candida species.
Rapid detection of group B streptococci directly from vaginal swabs
Authors: Wald E R , Dashefsky B , Green M , Harger J , Parise M , Korey C , Byers C
Published: January 2020

Duplicate vaginal swabs were obtained from patients who attended obstetric or gynecologic clinics affiliated with the Magee Womens Hospital in Pittsburgh. One swab was cultured semiquantitatively on 5% sheep blood agar to detect group B streptococci (GBS). The other swab was subjected to a rapid method (25 min) for antigen detection and micronitrous acid exposure to extract the GBS antigen, followed by latex particle agglutination. A total of 464 swabs were evaluated by direct plating. Fifty-two swabs (11.2%) were found to contain GBS. Overall, the rapid method detected 21 of 52, or 40.4%, positive specimens. The sensitivity of the rapid method for identifying the most heavily colonized samples was 85.7%. This method can be used to identify maternity patients who are heavily colonized with GBS and are at high risk of delivering septic infants.
Isolation of a spotted fever group rickettsia from a patient and related ecologic investigations in Xinjiang Uygur Autonomous Region of China
Authors: Fan M Y , Wang J G , Jiang Y X , Zong D G , Lenz B , Walker D H
Published: January 2020

Investigation of patients, healthy persons, and ticks in Jinghe County, Xinjiang Uygur Autonomous Region, People's Republic of China, for evidence of spotted fever group (SFG) rickettsiosis demonstrated strong evidence for a high prevalence of pathogenic SFG rickettsiae. Antibodies to SFG rickettsiae were detected in 62.5% of healthy subjects tested by enzyme-linked immunosorbent assay and 20% tested by complement fixation test. Two febrile patients were documented as having acute spotted fever rickettsiosis by complement fixation seroconversion. One, and 11-year-old Kazakh boy with eschar and regional lymphadenopathy, had an SFG rickettsia (An strain) isolated from his blood. A hemolymph test revealed that 20% of ticks contained rickettsiae. Two strains of SFG rickettsiae were isolated from male and female Dermacentor nuttalli ticks. The human SFG rickettsial isolate is the first to be obtained in the People's Republic of China.
Alginate production by clinical nonmucoid Pseudomonas aeruginosa strains
Authors: Anastassiou E D , Mintzas A C , Kounavis C , Dimitracopoulos G
Published: January 2020

The slime material from a revertant nonmucoid variant, derived by serial passage of a heavily mucoid Pseudomonas aeruginosa strain isolated from a patient with bacteremia, was found to contain 16% uronic acids, 48.5% carbohydrates, 11% protein, and 2% lipids. Chromatographic analysis by ion exchange chromatography revealed that this extracellular material consisted of three fractions, one uronic acid fraction with properties similar to those of the alginate fraction of the parental strain and two other fractions consisting of neutral sugars and proteins in approximately a 5:1 ratio. In addition, the slime material from six other clinical macroscopic nonmucoid P. aeruginosa strains was found to contain alginate. These results demonstrate that alginate production in various amounts is a property shared by all P. aeruginosa strains.