bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical and epidemiological features of acute infantile gastroenteritis associated with human rotavirus subgroups 1 and 2
Authors: Uhnoo I , Svensson L
Published: January 2020

During a prospective 1-year study rotavirus isolates from 169 children with gastroenteritis were investigated by polyacrylamide gel electrophoresis. A total of 118 (70%) of the strains analyzed contained sufficient viral nucleic acid to give visible electrophoretic patterns; 36% were identified as strains belonging to subgroup 1 (short patterns), and 64% were identified as strains belonging to subgroup 2 (long patterns). The two subgroups cocirculated at equal frequencies during the first 7 months of the year, after which subgroup 1 rotavirus completely disappeared. Subgroup 2 rotavirus occurred throughout the year. No significant differences between the subgroups in relation to age or sex distribution were observed. Fever and temperatures exceeding 39 degrees C were significantly more frequent in children who shed rotavirus subgroup 1. Diarrhea and vomiting occurred at similar rates in both groups of patients, but were more pronounced in children who shed rotavirus subgroup 2. One of three dominant electropherotypic variants of subgroup 2 rotavirus was found to be associated with more intense symptoms, higher rates of hospitalization, and a significantly higher frequency of respiratory symptoms; the clinical picture may indicate that this rotavirus electropherotype has higher virulence.
Enzyme-linked immunosorbent assay measurement of fluctuations in antibody titer and antigenemia in cancer patients with and without candidiasis
Authors: Fujita S , Matsubara F , Matsuda T
Published: January 2020

Antibody titers against purified sulfate-soluble fraction (PSSF) obtained from cytoplasmic extracts of Candida albicans were determined retrospectively over a 2-year period for 123 cancer patients by enzyme-linked immunosorbent assay. Antibody against cell wall mannan (CWM) was also measured by the hemagglutination test and the production of precipitins by a serum interacting with a yeast cell homogenate by immunodiffusion. Invasive candidiasis determined by histological evidence at autopsy was present in 10 patients. Fourfold or greater rises in anti-CWM and anti-PSSF antibodies were detected for eight of the patients with invasive candidiasis at 14 to 22 days after the onset of fever. The immunodiffusion test was positive for four patients with invasive candidiasis. For patients with no evidence of candidiasis, significant rises in anti-CWM and anti-PSSF antibodies were observed at a frequency of 20 and 10%, respectively. The concentrations of serum mannan were sequentially measured by the enzyme-linked immunosorbent assay. Antigenemia (greater than or equal to 3 ng/ml) was found in 9 of the 10 patients with invasive candidiasis and in 2 of the 4 patients with thrush, whereas the serum of 1 of the 36 patients with no evidence of candidiasis was positive for antigen. The first antigenemia antedated significant rises in antibody levels against Candida species by 6 to 23 days.
Comparison of cross-staining reactions by Pseudomonas spp. and fluorescein-labeled polyclonal and monoclonal antibodies directed against Legionella pneumophila
Authors: Tenover F C , Edelstein P H , Goldstein L C , Sturge J C , Plorde J J
Published: January 2020

Commercially prepared polyclonal antisera to Legionella pneumophila are known to cross-react with organisms of the genus Pseudomonas. To determine whether a commercially available monoclonal antibody reagent specific for L. pneumophila would also cross-react with pseudomonads, a two-laboratory study was undertaken to test both monoclonal and polyclonal reagents against 33 isolates of Pseudomonas spp., including 25 Pseudomonas aeruginosa, 4 P. putida, 2 P. maltophilia, 1 P. fluorescens, and 1 P. alcaligenes. Four antisera were tested; polyclonal anti-legionella antisera pools A and B (Centers for Disease Control [CDC], Atlanta, (Ga.), polyclonal 1-6 antisera (BioDx, Inc., Denville, N.J.), and a monoclonal antibody reagent produced by Genetic Systems Corp., Seattle, Wash. All reagents were labeled with fluorescein. Cross-staining reactions were found with the BioDx L. pneumophila antisera and 10 isolates of Pseudomonas. Four of these isolates demonstrated cross-staining with CDC pool A. When tested with individual serotype-specific reagents (CDC), three of four cross-reacted with L. pneumophila serotype 1 antisera; the fourth cross-reacted with serotype 3. No cross-staining reactions were noted with the monoclonal reagent and any of the pseudomonads tested, demonstrating that the Genetic Systems Corp. monoclonal reagent is the most specific of the four reagents tested.
Growth and cytopathogenicity of Trichomonas vaginalis in tissue cultures
Authors: Pindak F F , Gardner W A , Mora de Pindak M
Published: January 2020

The primary purpose of this study was to identify the mammalian tissue cultures which were most suitable for investigations of the cytopathogenicity of Trichomonas vaginalis. A recently isolated strain of the organism was inoculated into 15 different tissue cultures which were maintained in an appropriately modified growth medium. Proliferation of the protozoon was accompanied by the progressive disintegration of cell culture monolayers. Initial focal lesions consisting of detached cells and an accumulation of trichomonads gradually enlarged until the entire monolayer was disrupted. When judged by the size of the inoculum required to obtain this effect, differences among the tissue cultures were noted. An inoculum of approximately 10(3) viable trichomonads was sufficient to completely disrupt monolayers of HeLa 229, HeLa, McCoy, HEp-2, and RK-13 cells. To obtain a comparable effect with other cells, 10- to 100-fold higher levels of inoculum were required. Polyethylene glycol concentrates from culture filtrates contained a cell-detaching factor (CDF) which caused detachment and clumping of susceptible cells. Freshly seeded cells in growth medium containing CDF failed to form a monolayer. Aggregates of cells maintained for up to 1 week in the presence of CDF remained viable and formed a monolayer after being washed and suspended in normal growth medium. The activity of the CDF was not lost during 1 week of contact with the cells. The CDF may contribute to the pathogenicity mechanisms of T. vaginalis.
Modified ammonia electrode method to investigate D-asparagine breakdown by Campylobacter strains
Authors: Karmali M A , Roscoe M , Fleming P C
Published: January 2020

An ammonia electrode method has been developed for investigating the deamination of amino acids by bacteria. It consists of incubating a standard inoculum of organisms in an amino acid solution and then measuring the amount of ammonia evolved by the electrode. Two hundred and twelve Campylobacter strains (118 C. jejuni and 94 C. coli) were tested for their ability to break down D-asparagine by this method. Organism control (bacterial suspension in buffer alone) values ranged from 0.44 to 2.0 (mean 0.93 +/- 0.24) ammonia concentration (AC) units (one AC unit is equal to 10(-5) mol of ammonia per liter), whereas test values ranged from 0.60 to 46.0 units. Test ACs of less than 2 units (97 strains) were considered negative, whereas ACs of greater than or equal to 10 (77 strains) were considered positive for D-asparaginase; 38 (18%) strains with ACs between 2 and 10 units were provisionally assigned an intermediate status. The amount of ammonia produced by strains with ACs of greater than or equal to 10 increased greatly when the inoculum size was increased, whereas this was not a feature of strains with ACs of less than 2 units. The presence or absence of an inoculum effect was instrumental in classifying strains with intermediate ACs and allowed a breakpoint to be defined. When the ammonia electrode method was repeated, 97.6% of the 212 strains gave the same positive or negative reaction that they did on the first occasion. Thus the test was highly reproducible. Five strains (all porcine C. coli from Germany) were unclassifiable because they repeatedly gave either a weak-positive or negative reaction. Overall, 12.7% of C. jejuni strains and 86.2% of C. coli strains were positive for D-asparaginase. The ammonia electrode method was found to be simple and reliable for separating strains on the basis of D-asparaginase activity.
Selective medium for the isolation of Haemophilus aphrophilus from the human periodontium and other oral sites and the low proportion of the organism in the oral flora
Authors: Tempro P J , Slots J
Published: January 2020

We developed a medium for the selective recovery of Haemophilus aphrophilus. The medium, designated TSBVF, was composed of 4% tryptic soy agar, 10% heat-inactivated horse serum, 75 micrograms of bacitracin per ml, 5 micrograms of vancomycin per ml, and 50 micrograms of sodium fluoride per ml. TSBVF yielded a threefold higher recovery of oral H. aphrophilus than did chocolate agar with 75 micrograms of bacitracin per ml, which is a medium routinely used to diagnose human Haemophilus infections. H. aphrophilus and the few contaminating organisms on TSBVF were readily distinguished on the basis of colony morphology. The H. aphrophilus isolates exhibited variable fermentation of raffinose and dextrin but otherwise were biochemically similar. In a clinical study, H. aphrophilus was frequently recovered from supragingival plaque and saliva and occasionally from buccal mucosa and the tonsils. It was also isolated from 29 of 56 subgingival sites in 11 of 14 subjects. Its proportion of the subgingival microflora averaged 0.13% for healthy periodontal sites, 0.05% for adult periodontitis lesions, and 0.03% for localized juvenile periodontitis lesions. We concluded that H. aphrophilus is an indigenous bacterium of the human oral cavity. It occurs in low proportions in subgingival plaque and plays no apparent role in advanced periodontal disease in humans.
Salmonella susceptibility patterns in hospitals from 1975 through 1984
Authors: Lorian V
Published: January 2020

The susceptibility of salmonella to commonly used antibiotics was analyzed for the 10-year period 1975 through 1984. The susceptibilities of 19,200 strains isolated from a yearly average of 211 hospitals nationwide and 1,508 strains isolated at the Kings County Medical Center in Brooklyn, N.Y., were described. Nationally, the susceptibility to nine antibacterial agents, including tetracycline, did not change markedly for the decade. The slight increase in susceptibility to tetracycline observed nationally may reflect the decreased clinical use of this antibiotic during the decade studied.
Accuracy and reproducibility of the IDS rapID STR system for species identification of streptococci
Authors: Appelbaum P C , Jacobs M R , Palko W M , Frauenhoffer E E , Duffett A
Published: January 2020

The RapID STR system (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) was evaluated in the identification of 266 streptococci. Organisms included 60 beta-hemolytic streptococci, 71 group D strains (48 enterococci and 23 nonenterococci), 26 Streptococcus pneumoniae, and 109 viridans group strains. With concomitant optochin testing, as is currently recommended by the manufacturer for all alpha-hemolytic strains, the RapID STR system correctly identified 100% of beta-hemolytic strains, 87.3% of group D strains (93.7% of enterococci, 73.9% of nonenterococci), 88.5% of S. pneumoniae, and 72.5% of viridans strains. Without the use of optochin, the correct identification of S. pneumoniae and the viridans group was 26.9 and 52.3%, respectively. The RapID STR system incorrectly identified 3.0% of strains, including four group D streptococci, three pneumococci, and one viridans isolate. Reproducibility was excellent, with 95% of strains tested in triplicate yielding identical results on each of the three occasions. The RapID STR system represents a worthwhile advance in streptococcal species identification, especially for group D and viridans strains.
Evaluation of rapid coagulase methods for the identification of Staphylococcus aureus
Authors: Berke A , Tilton R C
Published: January 2020

Four rapid latex agglutination assays, StaphAurex (Wellcome Diagnostics, Research Triangle Park, N.C.), Bacto Staph (Difco Laboratories, Detroit, Mich.), SeroSTAT (Scott Laboratories, Inc., Fiskeville, R.I.), Veri-Staph (Zeus Technologies, Raritan, N.J.), and two hemagglutination tests, Staphyloslide (BBL Microbiology Systems, Cockeysville, Md.) and Hemastaph (Remel, Lenexa, Kans.), were compared with the conventional slide coagulase, tube coagulase (TC), and thermonuclease (TNase) tests for the identification of Staphylococcus aureus. A total of 118 clinical isolates of S. aureus (52 methicillin resistant), 50 S. epidermidis, 5 S. capitis, 2 S. hominis, 3 S. simulans, 6 S. saprophyticus, and 2 S. warneri were tested. The slide coagulase, TC and TNase tests detected 115 (97.5%), 117 (99.2%), and 118 (100%) of the S. aureus isolates, respectively. All showed 100% specificity. The StaphAurex, Veri-Staph, Staphyloslide, Hemastaph, SeroSTAT, and Bacto Staph assays correctly identified 117 (99.2%), 117 (99.2%), 116 (98.3%), 110 (93.2%), 108 (91.5%), and 107 (90.7%) of the S. aureus isolates, respectively. For methicillin-resistant S. aureus isolates, StaphAurex, Veri-Staph, Staphyloslide, Hemastaph, SeroSTAT, and Bacto Staph showed 1 (2%), 1 (2%), 2 (4%), 7 (13.5%), 7 (13.5%), and 8 (15.4%) false-negative results, respectively. All the commercial agglutination assays demonstrated false-positive results with strains of S. capitis, S. saprophyticus and S. warneri. The overall accuracy of the commercial agglutination assays compared with TC and TNase ranged from 90.7 to 99.2%. We recommend that negative reactions with the rapid commercial test kits for methicillin-resistant Staphylococcus isolates be confirmed with the TC or TNase test.
Comparison of lipopolysaccharide and outer membrane protein-lipopolysaccharide extracts in an enzyme-linked immunosorbent assay for the diagnosis of Brucella ovis infection
Authors: Riezu-Boj J I , Moriyón I , Blasco J M , Marín C M , Diaz R
Published: January 2020

Brucella ovis hot saline extracts and petroleum ether-chloroform-phenol lipopolysaccharide were compared in an enzyme-linked immunosorbent assay for the diagnosis of B. ovis ram epididymitis. Hot saline extracts detected greater numbers of infected rams. Chemical characterization of the antigens showed that, although both contained lipopolysaccharide, hot saline extracts also contained outer membrane proteins. These proteins were active as antigens in Western blot tests with sera of infected rams, and therefore they explained the better diagnostic results obtained with hot saline extracts. However, compared with lipopolysaccharide, hot saline extracts showed a higher degree of cross-reactivity with sera from smooth B. melitensis-infected animals. This observation might be explained by the presence of B. ovis outer membrane proteins in hot saline extracts which lack the specificity necessary for serological identification of the Brucella species present.
Diagnostic implications of parasite-specific immune responses in immunocompromised patients with strongyloidiasis
Authors: Genta R M , Douce R W , Walzer P D
Published: January 2020

Parasite-specific humoral and cellular immune responses were evaluated in in nine immunosuppressed patients with Strongyloides stercoralis infection. Four patients had the disseminated form of the disease, and five had serious manifestations without evidence of hyperinfection. All patients had high levels of immunoglobulin G (IgG) antibodies directed against S. stercoralis larval antigens as detected by the enzyme-linked immunosorbent assay. Seven patients had both elevated total serum IgE and parasite-specific IgE antibodies detected by a modified radioimmunoassay. The hyperinfected patients differed significantly from the nonhyperinfected group in total and specific IgE levels and peripheral eosinophilia but not in specific IgG levels. None of the patients tested exhibited significant in vitro lymphoproliferative responses to parasite antigens. Our results indicated that the possibility of a protective role of IgE and eosinophils in strongyloidiasis deserves further investigation. In addition, we suggest that the enzyme-linked immunosorbent assay for specific IgG antibodies may have an important place in the diagnosis of strongyloidiasis in immunocompetent as well as in immunocompromised patients.
Enterobacter asburiae sp. nov., a new species found in clinical specimens, and reassignment of Erwinia dissolvens and Erwinia nimipressuralis to the genus Enterobacter as Enterobacter dissolvens comb. nov. and Enterobacter nimipressuralis comb. nov
Authors: Brenner D J , McWhorter A C , Kai A , Steigerwalt A G , Farmer J J
Published: January 2020

Enterobacter asburiae sp. nov. is a new species that was formerly referred to as Enteric Group 17 and that consists of 71 strains, 70 of which were isolated from humans. Enterobacter asburiae sp. nov. strains gave positive reactions in tests for methyl red, citrate utilization (Simmons and Christensen's), urea hydrolysis, L-ornithine decarboxylase, growth in KCN, acid and gas production from D-glucose, and acid production from L-arabinose, cellobiose, glycerol (negative in 1 to 2 days, positive in 3 to 7 days), lactose, D-mannitol, alpha-methyl-D-glucoside, salicin, D-sorbitol, sucrose, trehalose, and D-xylose. They gave negative reactions in the Voges-Proskauer test and in tests for indole, H2S production, phenylalanine, L-lysine decarboxylase, motility, gelatin, utilization of malonate, lipase, DNase, tyrosine clearing, acid production from adonitol, D-arabitol, dulcitol, erythritol, i(myo)-inositol, melibiose, and L-rhamnose. They gave variable reactions in tests for L-arginine dihydrolase (25% positive after 2 days) and acid production from raffinose (69% positive after 2 days). Thirty-four Enterobacter asburiae sp. nov. strains were tested for DNA relatedness by the hydroxyapatite method with 32PO4-labeled DNA from the designated type strain (1497-78, ATCC 35953). The strains were 69 to 100% related in 60 degrees C reactions and 63 to 100% related in 75 degrees C reactions. Divergence within related sequences was 0 to 2.5%. Relatedness of Enterobacter asburiae sp. nov. to 84 strains of members of the Enterobacteriaceae was 5 to 63%, with closest relatedness to strains of Enterobacter cloacae, Erwinia dissolvens, Enterobacter taylorae, Enterobacter agglomerans, Erwinia nimipressuralis, and Enterobacter gergoviae. All strains tested were susceptible to gentamicin and sulfdiazine, and most were susceptible to chloramphenicol, colistin, kanamycin, nalidixic acid, carbenicillin and streptomycin. All strains were resistant to ampicillan, cephalothin, and penicillin, and most were resistant or moderately resistant to tetracycline. Enterobacter asburiae sp. nov strains were isolated from a variety of human sources, most prevalent of which were urine (16 strains), respiratory sources (15 strains), stools (12 strains), wounds (11 strains), and blood (7 strains). The clinical significance of Enterobacter aburiae is not known. As a result of this and previous studies, proposals are made to transfer Erwinia dissolvens and Erwinia nimipressuralis to the genus Enterobacter as Enterobacter dissolvens comb. nov. and Enterobacter nimipressuralis comb. nov., respectively.
Involvement of staphylococcal enterotoxins in nonmenstrual toxic shock syndrome
Authors: Crass B A , Bergdoll M S
Published: January 2020

Adequate evidence is available to show that the major toxin responsible for toxic shock syndrome (TSS) is TSS toxin 1 (TSST-1). More than 90% of the staphylococcal strains isolated from TSS patients produce this toxin. However, approximately 60% of these strains produce one or more of the staphylococcal enterotoxins, with a number of them producing only enterotoxin, primarily enterotoxin B. Of 55 staphylococcal strains isolated from nonmenstrual cases, 46 produced TSST-1; 42 produced one of the enterotoxins, including 8 that produced only enterotoxin B. The fact that the enterotoxins can produce in monkeys many signs and symptoms similar to those observed in TSS in humans implicates them as the cause of some cases of TSS.
Growth of Yersinia pseudotuberculosis and Yersinia enterocolitica biotype 3B serotype O3 inhibited on cefsulodin-Irgasan-novobiocin agar
Authors: Fukushima H , Gomyoda M
Published: January 2020

A total of 169 strains of Yersinia spp. were analyzed for their ability to grow on two different kinds of cefsulodin-Irgasan-novobiocin (CIN) agar containing 15 or 4 micrograms of cefsulodin per ml, on salmonella-shigella agar, and on MacConkey agar. CIN media inhibited the growth of Yersinia pseudotuberculosis and Yersinia enterocolitica biotype 3B serotype O3 (3B/O3) but not the growth of the other Yersinia organisms used. Relative to growth on Trypticase soy agar (BBL Microbiology Systems, Cockeysville, Md.) with 6% yeast extract, 48 and 44% of Y. pseudotuberculosis and Y. enterocolitica 3B/O3 strains, respectively, were inhibited on CIN I agar (low cefsulodin concentration), and 83 and 54%, respectively, were inhibited on CIN II agar (high cefsulodin concentration) after incubation for 24 h at 32 degrees C. The inhibition of Y. pseudotuberculosis growth was significantly more extensive on CIN II agar than on CIN I agar. The MICs of cefsulodin and novobiocin clearly indicated a higher susceptibility for Y. pseudotuberculosis than for the other Yersinia organisms at 32 degrees C. All Y. pseudotuberculosis strains were susceptible to cefsulodin at 15 micrograms/ml (the approximate concentration used in CIN II agar). Y. enterocolitica 3B/O3 strains were resistant to cefsulodin, Irgasan, and novobiocin at the concentrations used in CIN media. These findings show that cefsulodin inhibits the growth of Y. pseudotuberculosis at the concentration used in CIN media and that growth inhibition of Y. enterocolitica 3B/O3 is related to a component of the CIN Base.
Comparison of epidemiologic markers for Staphylococcus epidermidis
Authors: Parisi J T , Lampson B C , Hoover D L , Khan J A
Published: January 2020

Cultures of Staphylococcus epidermidis from the eyes or nose of the same individual were compared by their antimicrobial phenotype, Staph-Ident (Analytab Products, Inc., Plainview, N.Y.) profile number, phage type, and plasmid profile to determine which parameters provide the most compelling data for their identity. None of the parameters alone provided this type of information. The most conclusive data for the identity of strains resulted when two cultures had the same long phage type and identical or similar plasmid profiles. The presence of a large, slowly migrating plasmid band(s) in a culture that agreed with its pair in all other parameters and, in all likelihood, was the same strain casts doubt in some instances on the reliability of the plasmid profile alone for strain identification in an epidemiologic study.
Enzyme-linked immunosorbent assay for shigella toxin
Authors: Donohue-Rolfe A , Kelley M A , Bennish M , Keusch G T
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) was developed for the detection of shigella toxin. For the assay, a mouse monoclonal antibody against the B subunit of the toxin and a rabbit polyclonal antibody against the holotoxin were employed. The monoclonal antibody was used to coat wells of a microtiter plate, and the polyclonal antibody preparation was used as the detecting antibody. The amount of bound polyclonal antibody was determined by using a goat anti-rabbit immunoglobulin G-alkaline phosphatase conjugate and substrate. The ELISA was able to detect as little as 12 pg (0.06 ng/ml) of shigella toxin. The assay was specific for shigella toxin, not detecting a variety of other bacterial enterotoxins and lethal toxins. The ELISA values correlated well with cytotoxin activity during toxin purification. Shigella toxin was detected by ELISA and by immunoblot analysis in human fecal specimens from persons with S. dysenteriae infections, demonstrating that this toxin is produced in vivo.
Comparative evaluation of identification systems for testing methicillin-resistant strains of Staphylococcus aureus
Authors: Smith S M , Berezny C
Published: January 2020

Several commercial systems are available to distinguish between Staphylococcus aureus and the coagulase-negative species of the Micrococcaceae family. Four latex agglutination systems (Accu-Staph, SeroSTAT, Staphaurex, and Staphylatex) and two hemagglutination systems (Hemastaph and Staphyloslide) were compared for their performance in the rapid identification of 232 isolates of staphylococci, including 114 of methicillin-resistant S. aureus. Accu-Staph, Staphaurex, and Staphyloslide correctly identified 100% of the methicillin-resistant S. aureus isolates; Hemastaph and Staphylatex, 99.1%; and SeroSTAT, 94.7%. Most reactions were easy to interpret, although 15% of the SeroSTAT reactions were weak. Autoagglutination occurred only with isolates of coagulase-negative staphylococci. False-positive reactions were rare and occurred only with systems which did not detect autoagglutination. Five of these six systems appear to be adequate for the rapid identification of S. aureus, including methicillin-resistant isolates.
Predicting the susceptibility of anaerobes to cefoperazone, cefotaxime, and cefoxitin with the thioglycolate broth disk procedure
Authors: Zabransky R J , Birk R J , Kurzynski T A , Toohey K L
Published: January 2020

A variety of clinical anaerobic isolates were tested against cefoperazone (216 strains), cefoxitin (120 strains), and cefotaxime (120 strains) by the thioglycolate anaerobic broth disk method, and the results were compared with the National Committee for Clinical Laboratory Standards reference agar dilution method. The broth disk and reference breakpoint concentrations were as follows: cefoperazone, 60 and 64 or 30 and 32 micrograms/ml; cefotaxime, 30 and 32 micrograms/ml; cefoxitin, 18 and 16 micrograms/ml, respectively. Discrepant results were retested to obtain a mode. There was 99% agreement between the broth disk and reference methods for cefotaxime, 98% for cefoperazone with 60- and 64-micrograms/ml breakpoints and 91% with 30- and 32-micrograms/ml breakpoints, and 75% for cefoxitin. All but one of the strains that produced false susceptibility results by broth disk were members of the Bacteroides fragilis group, 1 with cefoperazone using the 60-micrograms/ml concentration, 14 with cefoperazone at the 30-micrograms/ml concentration, and 27 with cefoxitin. One strain of Clostridium difficile produced false susceptibility results to cefoperazone at the 30-micrograms/ml concentration. The lack of agreement between the broth disk and reference methods with cefoxitin may be a reflection of the number of isolates at the 16-micrograms/ml level and that the broth disk breakpoint was slightly higher than this concentration. Increased incubation time did not improve the results significantly.
Polysaccharide surface antigens expressed by nonmucoid isolates of Pseudomonas aeruginosa from cystic fibrosis patients
Authors: Pier G B , Desjardins D , Aguilar T , Barnard M , Speert D P
Published: January 2020

We tested nonmucoid Pseudomonas aeruginosa isolates obtained from cystic fibrosis (CF) patients for the expression of lipopolysaccharide (LPS) serotype antigens, serum sensitivity, and production of mucoid exopolysaccharide (MEP). When all nonmucoid isolates were compared with a set of random mucoid isolates, 20 of 52 (38%) nonmucoid isolates were typable and serum resistant, compared with 13 of 51 (24%) mucoid isolates (P = 0.16 by chi-square analysis). However, nonmucoid strains from CF patients colonized only with nonmucoid strains were more frequently typable and serum resistant (67%) than were nonmucoid isolates from patients cocolonized with mucoid strains (31%) (P = 0.012, Fisher exact test). An inhibition enzyme-linked immunosorbent assay done with bacterial extracts, a direct-whole-cell enzyme-linked immunosorbent assay done with affinity-purified antibody to MEP, and immune electron microscopy all demonstrated production of MEP by all nonmucoid P. aeruginosa isolates tested, including nonmucoid revertants of mucoid strains. No other bacterial species tested positive in these assays. These findings suggest that MEP is produced by all P. aeruginosa isolates obtained from CF patients, that the initial colonizing nonmucoid strains produce a smooth LPS, and that once LPS-rough, mucoid strains appear in the sputum, the predominant LPS phenotype is rough regardless of colony morphology.
Phaeohyphomycosis of the nasal sinuses caused by a new species of Exserohilum
Authors: Padhye A A , Ajello L , Wieden M A , Steinbronn K K
Published: January 2020

A 27-year-old man with a 6-year history of allergies developed nasal polyps that occluded his nose and prevented visual examination beyond the nasal vestibules. Histological examination of the polyps and bony tissue revealed septate, dematiaceous hyphae invading the bone trabeculae. A dematiaceous fungus was isolated in pure culture from the diseased tissue. Detailed mycological examination of the isolate showed that it produced numerous, distinctive poroconidia from erect, geniculate, sympodial conidiophores. The conidia were straight and cylindroellipsoidal, had 8 to 13 distosepta, and had protruding hila. The outer cell walls of the conidia, which were initially smooth, became unevenly roughened on aging. Comparison with other Exserohilum species revealed that the isolate represented an undescribed species; it is named Exserohilum mcginnisii sp. nov.
Emerging agents of phaeohyphomycosis: pathogenic species of Bipolaris and Exserohilum
Authors: McGinnis M R , Rinaldi M G , Winn R E
Published: January 2020

Study of numerous living isolates of Bipolaris, Drechslera, Exserohilum, and Helminthosporium spp., as well as a mycological assessment of published case reports of phaeohyphomycosis attributed to these fungi, showed that Bipolaris australiensis, B. hawaiiensis, B. spicifera, Exserohilum longirostratum, E. mcginnisii, and E. rostratum are well-documented pathogens. Conidial shape, septation, and size, hilar characteristics, the origin of the germ tube from the basal cell and, to a lesser extent, from other conidial cells, and the sequence and location of the conidial septa are useful criteria for distinguishing these taxa.
Cutoff levels of immunoglobulin M antibody against viral core antigen for differentiation of acute, chronic, and past hepatitis B virus infections
Authors: Gerlich W H , Uy A , Lambrecht F , Thomssen R
Published: January 2020

The titer of antibody against core antigen of hepatitis B virus in the immunoglobulin M class (IgM anti-HBc) was determined by an IgM capture assay of reduced sensitivity (30 arbitrary units). The distribution of titers among 235 acute hepatitis patients who were hepatitis B surface antigen (HBsAg) positive suggested that 600 U forms a lower cutoff value for acute hepatitis B. Clinically apparent cases of acute hepatitis with high IgM anti-HBc and without HBsAg were rare (2.6%). Acute, non-B hepatitis in HBsAg carriers was more frequent (9.4%). In chronic hepatitis B, 39% of 174 biopsy-proven cases had moderate titers of 30 to 600 U, whereas healthy HBsAg carriers were rarely (4/84) positive. In mild or inapparent infections without HBsAg, titers were between 50 and 400 U. Thus, sufficiently accurate and sensitive quantitation of IgM anti-HBc allows for differentiation of acute and nonacute hepatitis B virus infection in acute hepatitis, partial differentiation between clinically symptomatic and asymptomatic chronic infections, and identification of recent subclinical infections.
Stability of immunofluorescence reactions produced by polyclonal and monoclonal antibody conjugates for rabies virus
Authors: Durham T M , Smith J S , Reid F L , Hale-Smith C T , Fears M B
Published: January 2020

We investigated two consumer complaints that described fading of immunofluorescence reactions associated with the use of a commercial antirabies, fluorescein-labeled, monoclonal antibody conjugate. We compared the performance of this product with that of two polyclonal antibody antirabies conjugates and observed significant diminution of fluorescence with the monoclonal antibody conjugate only. Furthermore, the fading occurred only on tissue impressions that had been mounted but not exposed to UV light excitation, thereby essentially eliminating the photobleaching associated with fluorescence microscopy as a causative factor. Our observations suggest that mounting medium pH and the holding temperature of stained slides may be critical factors in maintaining optimal immunofluorescence reactions with this monoclonal antibody conjugate. We discuss some probable mechanisms that could produce the type of fading observed and also suggest certain precautionary measures for use with this monoclonal antibody conjugate.
Enzyme-linked immunosorbent assay spin amplification technique for herpes simplex virus antigen detection
Authors: Michalski F J , Shaikh M , Sahraie F , Desai S , Verano L , Vallabhaneni J
Published: January 2020

A comparative study of herpes simplex virus diagnosis by standard cell culture and a new hybrid test (enzyme-linked immunosorbent assay spin amplification technique) was done on 300 specimens. The new test was found to be equally sensitive and specific, much less expensive to perform, and to report all results in 48 h.
Evaluation of dot enzyme-linked immunosorbent assay for mucocutaneous leishmaniasis and comparison with microplate enzyme immunoassay
Authors: Guimarães M C , Celeste B J , Franco E L
Published: January 2020

A dot enzyme-linked immunosorbent assay (dot ELISA) was evaluated and compared with a standard microplate ELISA (immunoglobulin G [IgG] ELISA) for the serological diagnosis of mucocutaneous leishmaniasis. The two assays were used to test 113 serum specimens from the following groups: normal individuals and patients with deep mycoses, toxoplasmosis, mucocutaneous leishmaniasis, visceral leishmaniasis, Chagas' disease, malaria, and schistosomiasis. Both tests exhibited cross-reactivity when testing specimens from cases of visceral leishmaniasis and Chagas' disease. The dot ELISA proved to be economical with respect to use of reagents and was easy to perform. Interpretation could easily be made by visual inspection of reaction endpoints in the nitrocellulose disks, obviating the need for spectrophotometric readings. There were no significant differences in sensitivity between the dot ELISA and the IgG ELISA at a cutoff level either of 20 or 40. However, its most remarkable feature was the high specificity compared with that of the IgG ELISA. Because of its ease of performance and high sensitivity and specificity, the dot ELISA should be an excellent test to be executed in the field during seroepidemiological surveys.
Immunoblotting to demonstrate antigenic and immunogenic differences among nine standard strains of Clostridium difficile
Authors: Heard S R , Rasburn B , Matthews R C , Tabaqchali S
Published: January 2020

The epidemiology of Clostridium difficile-associated disease is being elucidated with the development of typing schemes for the organism. We recently described a new typing scheme based on the incorporation of [35S]methionine into bacterial proteins followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and autoradiography. Nine standard strains were identified. We report here some observations on the antigenic differences among these nine strains when studied by immunoblotting. Type-specific rabbit antiserum was raised against each of the nine standard strains. Immunoblotting of the strains with these antisera demonstrated, in addition to the presence of shared, common proteins, a type-specific response with homologous antisera. When [35S]methionine-labeled C. difficile proteins were immunoblotted with homologous and heterologous antisera, both the immunoblots and the autoradiographs demonstrated the same strain-specific response. These strain-specific proteins, which have been so useful for epidemiological and typing purposes, were also immunogenic.
Serum bactericidal testing with the Autobac system
Authors: Sanders S J , Gavan T L , Senturia J B , Smeby R R
Published: January 2020

Current methodology for the serum bactericidal test requires a minimum of 48 h. A procedure was devised for performing this test with the Autobac system (General Diagnostics, Div. Organon Inc., Raleigh, N.C.) in a shortened time span. All titers obtained with the Autobac were compared against results obtained with a standardized tube dilution procedure. The Autobac low-thymidine eugonic broth performed comparably to the tube dilution diluent, a 1:1 ratio of pooled human serum and cation-supplemented Mueller-Hinton broth (99.2% correlation between bactericidal endpoints). Over 300 tests were conducted by using stock reference bacterial strains, clinical isolates, pooled human serum seeded with antimicrobial agents, and serum from patients on antimicrobial therapy. With the Autobac procedure, serum inhibitory titers can be reported in 3 to 4 h (93.4% correlation with the tube dilution procedure). Serum bactericidal titers can be obtained in 24 h without the necessity of subculturing (95.6% correlation). With the exception of staphylococci tested against penicillin, serum bactericidal titers can be obtained in 3 to 4 h (88.4% correlation). The Autobac procedure can provide the clinical laboratory with a rapid, reliable method for performing the serum bactericidal test.
Rapid diagnosis of severe Haemophilus influenzae serotype b infections by monoclonal antibody enzyme immunoassay for outer membrane proteins
Authors: Belmaaza A , Hamel J , Mousseau S , Montplaisir S , Brodeur B R
Published: January 2020

A highly sensitive and specific enzyme immunoassay (EIA) for the detection of Haemophilus influenzae serotype b antigens in body fluids and broth cultures was developed, with a polyclonal antibody directed against polyribose phosphate as the solid-phase reagent and a biotinylated monoclonal antibody directed against H. influenzae type b outer membrane protein as the liquid-phase reagent. H. influenzae type b antigens could be detected in broth cultures containing as little as 50 organisms per ml. The sensitivity and specificity of this system were compared with those of two commercial kits and counterimmunoelectrophoresis. The overall detection of H. influenzae type b antigens in clinical specimens collected from children infected with H. influenzae type b was as follows: with Phadebact, 86 and 86% in cerebrospinal fluid and urine specimens, respectively; with Bactigen, 86, 80, and 92%, with counterimmunoelectrophoresis, 78, 73, and 75%, and with biotin-avidin EIA, 100, 100, and 100% for cerebrospinal fluid, serum, and urine specimens, respectively. In the biotin-avidin EIA, no positive reactions were noted in specimens collected from patients infected with other bacteria or from patients without evidence of bacterial infection, whereas false-positive reactions were found by counterimmunoelectrophoresis and the commercial kits. These results suggest that this monoclonal antibody reacting with the outer membrane protein is more specific and sensitive than the conventional methods using polyclonal antisera for the detection of H. influenzae type b antigens during severe infections in children.
Comparative efficacy of seven selective media for isolating Campylobacter jejuni
Authors: Merino F J , Agulla A , Villasante P A , Díaz A , Saz J V , Velasco A C
Published: January 2020

Diarrheal stools from 263 patients were inoculated on seven selective media: Butzler selective medium, Blaser medium, Skirrow blood agar, Preston campylobacter selective medium, Preston campylobacter blood-free medium, Butzler Virion medium, and modified Preston medium (with amphotericin B [2 mg/liter]). A similar number of Campylobacter jejuni strains were isolated from all the media studied; nevertheless, the presence of competing fecal flora (FF) made the detection of suspect colonies difficult. Preston campylobacter blood-free medium with cefoperazone yielded the greatest number of C. jejuni isolations, and contaminating FF grew in only 9% of the plates showing C. jejuni growth; all the other media allowed the abundant growth of other FF, regardless of whether C. jejuni was isolated from them or not.
Enzyme-linked immunosorbent assays for Snow Mountain and Norwalk agents of viral gastroenteritis
Authors: Madore H P , Treanor J J , Pray K A , Dolin R
Published: January 2020

Enzyme-linked immunosorbent assays (ELISAs) for antigen detection and blocking ELISAs for serum antibody rises were developed for the Snow Mountain and Norwalk agents of viral gastroenteritis. The ELISAs were as sensitive as the existing radioimmunoassays and were specific for the Snow Mountain or Norwalk agent. The blocking ELISAs detected the same number of significant rises in antibodies to these agents as did the existing blocking radioimmunoassays.
Modification of the Sceptor system for rapid detection of methicillin-resistant staphylococci
Authors: Denys G A , Sahm D F
Published: January 2020

The 24-h Sceptor MIC system (Johnston Laboratories, Inc., Towson, Md.) was modified to allow rapid (6 h) detection of methicillin-resistant staphylococci. For 105 methicillin-resistant staphylococci tested, 90% of the results obtained by the 6-h method agreed with those obtained by disk agar diffusion. In comparison, 88 and 93% of the results obtained by the AutoMicrobic system (Vitek Systems, Inc., Hazelwood, Mo.) and the 24-h conventional Sceptor system, respectively, agreed with disk agar diffusion results. No false-resistant results were observed with 52 methicillin-susceptible staphylococci tested by any of the three methods.
Broad-spectrum enzyme-linked immunosorbent assay for detection of Legionella soluble antigens
Authors: Tang P W , Toma S
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) was developed which detected soluble antigens from culture extracts of Legionella pneumophila serogroups 1 to 8, L. micdadei, L. bozemanii serogroups 1 and 2, L. dumoffii, L. gormanii, L. longbeachae serogroups 1 and 2, L. wadsworthii, L. oakridgensis, L. anisa, L. feeleii serogroup 1, and L. jordanis. The assay was approximately 10-fold more sensitive for the eight L. pneumophila serogroups than for the other Legionella species tested. The ELISA detected Legionella antigens in the urine specimens of 25 of 35 patients with L. pneumophila serogroup 1, 3, 4, 6, and 8; L. micdadei; and L. longbeachae serogroup 1 infections. None of the 334 urine specimens from patients with either non-Legionella pneumonia or urinary tract infections was positive. For 10 patients from whom sequential urine specimens were available, Legionella antigens were not detectable from 7 to 19 days after laboratory diagnosis. Test sensitivity was not affected by heavy bacterial contamination. This ELISA offers the detection of a broad spectrum of Legionella antigens by a single test.
Characterization of Wolinella spp., Campylobacter concisus, Bacteroides gracilis, and Eikenella corrodens by polyacrylamide gel electrophoresis
Authors: Tanner A C
Published: January 2020

The small asaccharolytic, nonpigmenting gram-negative rods of the human oral cavity are difficult to differentiate from each other. Protein profiles of sonicated cells of Wolinella species, Campylobacter concisus, Bacteroides gracilis, and Eikenella corrodens were obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and visualized with a silver stain. The gels were scanned with a laser densitometer, and the similarity of strains was computed by determining correlation coefficients of normalized densities along the gels. The strains were grouped by cluster analysis of the correlation coefficients. All species were distinct from each other. Several groups were found within E. corrodens. A colored silver stain was found to highlight species differences and appears to be useful in the rapid identification of fresh isolates.
New test system for identification of Aerococcus, Enterococcus, and Streptococcus species
Authors: You M S , Facklam R R
Published: January 2020

A total of 244 strains of Aerococcus, Enterococcus, and Streptococcus species were tested by the RapID STR system (Innovative Diagnostic Systems Inc., Atlanta, Ga.) for identification. Strains were identified without additional tests or with additional conventional tests suggested by the IDS compendium manual. Our data indicate that the RapID STR system identifies 89% of the beta-hemolytic Streptococcus species if serological procedures are used in conjunction with the rapid physiological procedures. Of the group D streptococci, 98% of the Enterococcus species and 100% of the group D non-Enterococcus species were correctly identified. Of the commonly occurring viridans group Streptococcus species, 93% were correctly identified, and 79% of the less frequently occurring viridans group Streptococcus species were correctly identified. All of the Streptococcus pneumoniae and Aerococcus strains tested were correctly identified.
Peptostreptococcal vertebral osteomyelitis
Authors: Papasian C J , McGregor D H , Hodges G R , Kennedy J
Published: January 2020

The clinical course of a patient with vertebral osteomyelitis caused by Peptostreptococcus micros is described. The organism was isolated on two occasions from lumbar vertebral biopsies and was visualized in histologic sections of one of the biopsies. The patient had no apparent infections at other body sites. The infection was eradicated after 6 weeks of intravenous clindamycin therapy.
Cefixime disk susceptibility test criteria
Authors: Fuchs P C , Barry A L , Jones R N
Published: January 2020

A total of 583 bacterial isolates was tested for susceptibility to cefixime by broth microdilution and by disk agar diffusion with 5-, 10-, and 30-microgram disks. At MIC breakpoints of less than or equal to 1.0 and greater than or equal to 4 micrograms/ml for susceptible and resistant, respectively, the 5-microgram disk showed slightly better discrimination. The 5-microgram cefixime disk is recommended with proposed interpretive breakpoint criteria of: less than or equal to 17 mm, resistant; 18 to 20 mm, intermediate; and greater than or equal to 21 mm, susceptible.
Species-specific monoclonal antibody to a 43,000-molecular-weight membrane protein of Mycoplasma pneumoniae
Authors: Madsen R D , Saeed F A , Gray O , Fendly B M , Coates S R
Published: January 2020

A murine immunoglobulin G1 monoclonal antibody was produced that binds to a protease-sensitive, periodate-insensitive epitope on a 43,000-molecular-weight Mycoplasma pneumoniae membrane polypeptide. The 43,000-molecular-weight polypeptide appeared to be a major antigenic component of M. pneumoniae, as determined by immunoblot analysis. This monoclonal antibody reacted with 33 different clinical isolates of M. pneumoniae, but not with normal-flora Mycoplasma species or 18 other microorganisms potentially inhabiting the normal or diseased human respiratory tract. This apparent species-specific monoclonal antibody may have application for the detection of M. pneumoniae antigen in clinical specimens.