bluuebunny/crossref_metadata_2025 huggingface dataset:
Delta toxin activity in coagulase-negative staphylococci from the bowels of neonates
Authors: Scheifele D W , Bjornson G L
Published: January 2020

Coagulase-negative staphylococci are prominent in stools of neonates in some intensive care units and have been associated with necrotizing enterocolitis. A plausible mediator of bowel damage is delta-like toxin, which is produced in vitro by most coagulase-negative staphylococci, but factors influencing the expression of toxin in the bowel are unknown. We examined 105 coagulase-negative staphylococcus isolates from stools of neonates by using an enzyme-linked immunosorbent assay and detected delta toxin production by 92 isolates (88%). The amount present in 18-h broth cultures varied over 100-fold, from 933 to 125,000 ng/ml. All broths positive by enzyme-linked immunosorbent assay except one caused hemolysis of human erythrocytes. The threshold concentration for consistent cytotoxicity to fibroblasts was greater than or equal to 24,000 ng/ml. Only 56% of Staphylococcus epidermidis isolates were capable of producing this much toxin, and these were more often obtained from premature infants in intensive care than from healthy full-term infants (P = 0.003) and were more often resistant to multiple antibiotics (P less than 0.001). Cultures grown anaerobically seldom caused hemolysis (4 positive of 29 tested; P less than 0.001) because potency of the toxin was decreased (at least ninefold for S. epidermidis isolates). We conclude that only a portion of the fecal coagulase-negative staphylococci tested produced enough delta toxin in vitro to be cytotoxic, that such isolates have accumulated in our intensive care nursery, and that development of toxin-mediated bowel injury may also require a favorable redox potential within the host bowel.
Comparative studies of commercially available particle agglutination assay and enzyme-linked immunosorbent assay for screening of human T-cell leukemia virus type I antibodies in blood donors
Authors: Kobayashi S , Yoshida T , Hiroshige Y , Matsui T , Yamamoto N
Published: January 2020

Human T-cell leukemia virus type I (HTLV-I) transmission during blood transfusion can be prevented by screening for and eliminating blood containing anti-HTLV-I antibodies. For this purpose, we evaluated two commercial test kits for HTLV-I antibodies, Serodia-ATLA (particle agglutination assay [PA]) and Eitest-ATL (enzyme-linked immunosorbent assay [ELISA]), by using serum samples from Japanese blood donors. Of 2,316 serum samples, 39 (1.7%), 34 (1.5%), and 28 (1.2%) were positive for the antibody by PA, ELISA, and immunofluorescence (IF), respectively. The coincidence rate for antibody-positive and antibody-negative results was 99.5% between PA and IF, whereas it was 99.6% between ELISA and IF. The serum samples which were positive by IF were also positive by PA, whereas 2 of 26 IF-positive samples were negative by ELISA. All the samples positive by both PA and ELISA were shown to be positive by IF unequivocally. The samples positive by only one of the two methods (PA or ELISA) were different. Eleven and eight serum samples that were negative by IF but positive by PA and ELISA, respectively, were further studied for HTLV-I antibody by radioimmunoprecipitation. Three of the former but none of the latter were found to be positive for antibody. Moreover, a PA-positive but IF-negative serum sample was shown to have significantly decreased PA titers after 2-mercaptoethanol treatment. The PA was further shown to detect not only IgG antibody but also IgM antibody to HTLV-I after separation of this serum sample by high-performance liquid chromatography.
Commercial identification systems often fail to identify Providencia stuartii
Authors: Cornaglia G , Dainelli B , Berlutti F , Thaller M C
Published: January 2020

We tested 145 clinical isolates in an attempt to evaluate some of the most widely used commercial identification systems in Europe in terms of their ability to identify Providencia strains. Two manual miniaturized systems (API 20E and Enterotube II) and three mechanized-automated systems (Cobas-Bact, Sceptor System, and Titertek-Enterobac-Rapid Automated System) were evaluated. Providencia alcalifaciens and Providencia rettgeri strains were correctly identified by all systems in all cases, and in most cases identification was achieved without the aid of supplementary tube tests. By contrast, Providencia stuartii was identified without the aid of supplementary tube tests for only 42.5% (API 20E), 37.5% (Enterotube), 68.7% (Sceptor), and 71.2% (Cobas-Bact) of the isolates. The overall misidentification rates were 16.3, 11.3, 11.3, and 10%, respectively. The Titertek-Enterobac-Rapid Automated System failed to identify only 1 of 80 strains (1.3%) and required supplementary tests in 2 other cases (2.5%). Since four of the multitest systems examined often failed to correctly identify P. stuartii, we conclude that supplementary conventional tube tests should always be used to distinguish this species from the other taxa of the Proteeae tribe.
Antibody response in humans to influenza virus type B host-cell-derived variants after vaccination with standard (egg-derived) vaccine or natural infection
Authors: Harmon M W , Rota P A , Walls H H , Kendal A P
Published: January 2020

Hemagglutination inhibition (HI) and neutralization tests were used to determine antibody responses to egg-derived and Madin-Darby canine kidney (MDCK)-derived influenza B virus (B/England/222/82) in paired sera from persons naturally infected with influenza B and in persons vaccinated with standard egg-derived inactivated influenza vaccine. When tested by HI, the MDCK-derived antigen gave significantly higher (8- to 12-fold) geometric mean titers (GMT) in convalescent-phase sera from persons naturally infected during community outbreaks, as well as more 4-fold titer rises, than did tests with egg-derived antigen. When tested by neutralization, however, the convalescent-phase sera GMTs were only threefold higher with the MDCK-derived antigen and an equivalent number of fourfold titer rises were detected with both antigens. With postvaccine sera, the MDCK-derived antigen gave GMTs that were threefold higher than those obtained with egg-derived antigen in both the HI and neutralization tests and both antigens detected an equivalent number of fourfold titer rises in HI and neutralization tests. Sucrose gradient-fractionated egg-derived antigen showed a single peak of hemagglutinin activity corresponding to whole virions, whereas MDCK-derived antigen contained two distinct peaks of hemagglutinin activity, one of which had a lower sedimentation rate. The overall findings indicate that the egg-derived antigen in the vaccine induced HI and neutralizing antibody to both egg- and MDCK-derived variants and suggest that titers of antibody to MDCK-derived virus may be affected by the physical form of the hemagglutinin antigen.
Modification of potassium nitrate assimilation test for identification of clinically important yeasts
Authors: Pincus D H , Salkin I F , Hurd N J , Levy I L , Kemna M A
Published: January 2020

The modification of an auxanographic method used in yeast species identification to determine potassium nitrate (KNO3) assimilation resulted in a simple and inexpensive KNO3 assimilation test medium. The medium provided accurate and reliable results in less than 24 h.
Comparison of three enzyme-linked immunosorbent assays and a direct fluorescent-antibody test for detection of respiratory syncytial virus antigen
Authors: Krilov L R , Marcoux L , Isenberg H D
Published: January 2020

We prospectively evaluated three enzyme immunoassays (EIAs) and a direct fluorescent-antibody (DFA) test for respiratory syncytial virus detection. Of 90 specimens, 79% gave the same results in all four tests (30 positive and 41 negative) and 97% were in agreement in three of the four assays. The agreement between the direct fluorescent-antibody test and each enzyme immunoassay was greater than or equal to 86%.
Legionella pneumophila serogroup 14 isolated from patients with fatal pneumonia
Authors: Benson R F , Thacker W L , Wilkinson H W , Fallon R J , Brenner D J
Published: January 2020

Two Legionella-like organisms, one isolated from postmortem lung tissue and the other from a bronchial aspirate, were shown by growth, physiologic, and genetic characteristics to belong to the species Legionella pneumophila. Subsequent serologic testing indicated that both strains belonged to a new serogroup, serogroup 14.
UV red fluorescence of Veillonella spp
Authors: Brazier J S , Riley T V
Published: January 2020

A total of 34 clinical isolates and 7 type strains of Veillonella spp. were tested for their ability to fluoresce on various culture media. Fluorescence was medium dependent and varied among the species. Scanning absorption spectrophotometry of culture extracts showed that the absorption spectrum of the fluorescent pigment is typical of a metal-free porphyrin.
Proctitis and fatal septicemia caused by Plesiomonas shigelloides in a bisexual man
Authors: Nolte F S , Poole R M , Murphy G W , Clark C , Panner B J
Published: January 2020

A case of proctitis and fatal septicemia caused by Plesiomonas shigelloides in a 42-year-old bisexual male is reported. The medical history of the patient was significant for an aortic valve replacement 3 years before but was otherwise unremarkable. A serum specimen obtained at autopsy was negative for antibody to human immunodeficiency virus by Western blot (immunoblot) analysis. P. shigelloides isolated from blood was susceptible to all antibiotics tested, agglutinated in Shigella group D antiserum, possessed a greater than 100-megadalton plasmid, and was noninvasive in a HeLa cell invasion assay. The previous reports of Plesiomonas bacteremic infections are reviewed, and possible pathogenic mechanisms are discussed.
Effect of incubation temperature on growth and soluble protein profiles of motile Aeromonas strains
Authors: Statner B , Jones M J , George W L
Published: January 2020

Motile Aeromonas spp. are said to have an optimal growth temperature of 28 degrees C. We performed growth studies on 24 isolates at 29 and 37 degrees C and found that the optimal growth temperature was not necessarily 28 degrees C. We also detected temperature-dependent differences in soluble protein production in some of these strains.
Value of needle aspiration in bacteriologic diagnosis of cellulitis in adults
Authors: Newell P M , Norden C W
Published: January 2020

We prospectively studied 30 adult patients with cellulitis, including many who were hospitalized with significant underlying medical problems. Needle aspiration of both central and leading edge areas of their lesions was performed in an attempt to establish a bacteriologic diagnosis. Potential pathogens were isolated by this technique in only 10% of the patients. Neither site of aspiration was clearly superior in terms of culture yield. Because aspirate Gram stains and cultures so rarely provided useful bacteriologic information, they were seldom helpful in guiding antibiotic selection or in influencing the outcome of treatment in most patients. However, clinical information, as well as results of primary lesion cultures when obtainable, may be used to successfully select therapy in most cases of adult cellulitis. On the basis of our results, needle aspiration may not be justified as a routine diagnostic procedure for all adults with cellulitis, though it may still be useful in selected patients.
Risk factors for candidemia in cancer patients: a case-control study
Authors: Karabinis A , Hill C , Leclercq B , Tancrède C , Baume D , Andremont A
Published: January 2020

Risk factors for candidemia were analyzed in a case-control study of 30 cancer patients with candidemia and 58 controls. In a univariate analysis, previous surgery, neutropenia, central catheterization, chemotherapy, specific antibiotic treatments, and peripheral cultures positive for Candida spp. were associated with a significantly increased risk of candidemia. In a multivariate logistic model, the significant risk factors for candidemia were positive peripheral cultures for Candida spp. (P = 0.02), central catheterization (P = 0.03), and neutropenia (P = 0.05). These results should help to identify cancer patients with a high risk of candidemia, who should be given early systemic antifungal therapy.
Diagnosis of systemic candidiasis by an enzyme-linked dot immunobinding assay for a circulating immunodominant 47-kilodalton antigen
Authors: Matthews R , Burnie J
Published: January 2020

A dot immunobinding assay based on the detection of the immunodominant 47-kilodalton (kDa) antigen of Candida albicans is described for the serological diagnosis of systemic candidiasis. It was compared with a reverse passive latex agglutination test and a dot immunobinding assay with total unfractionated hyperimmune serum to C. albicans. Use of the 47-kDa antigen-specific probe increased both the sensitivity and specificity of the assay system. Patients with systemic candidiasis were detected earlier in the course of the infection. The rate of detection of systemic C. albicans infections in neutropenic patients was 77% compared with 55% with total antibody in the dot immunobinding assay and 29% with the latex test. All three assay systems were positive in over 73% of infected patients who were not neutropenic. The 47-kDa antigen-specific probe was relatively specific to C. albicans. Antibody probes to the immunodominant antigens of other yeasts might be incorporated in the same dot immunobinding assay to detect systemic candidiasis caused by other species of yeasts.
Scedosporium inflatum, an emerging pathogen
Authors: Salkin I F , McGinnis M R , Dykstra M J , Rinaldi M G
Published: January 2020

The salient morphologic and physiologic characteristics of 18 isolates of Scedosporium inflatum, a newly reported human pathogen, were compared with those of the morphologically similar fungi Scedosporium apiospermum, Scopulariopsis brevicaulis, and Scopulariopsis brumptii. The formation by S. inflatum of annelloconidia in wet clumps at the apices of annellides with swollen bases was found to be the most useful characteristic in differentiating this potential pathogen.
Electrophoretic characterization of Clostridium difficile strains isolated from antibiotic-associated colitis and other conditions
Authors: Pantosti A , Cerquetti M , Gianfrilli P M
Published: January 2020

Clostridium difficile has been recognized as the cause of antibiotic-associated pseudomembranous colitis and of less severe diarrheal diseases associated with the use of antimicrobial agents. However, healthy carriers of this microorganism have been found, particularly healthy neonates and small children. Various typing systems have been used to clarify the epidemiology of C. difficile. We used the electrophoretic patterns of EDTA-extracted proteins to characterize C. difficile strains from various sources. Altogether, 110 strains were studied, including 2 reference strains, and 21 different protein profiles were obtained. However, two patterns were the most common: the group 2 pattern, characterized by a major 35-kilodalton polypeptide band, and the group 5 pattern, identified by principal bands of 37 and 56 kilodaltons. The group 2 pattern was characteristic of strains isolated during hospital outbreaks and from sporadic cases of pseudomembranous colitis and antibiotic-associated diarrhea. The group 5 pattern was obtained only from isolates from healthy neonates and children. A correlation between electrophoretic characteristics and virulence can be hypothesized, namely that group 2 strains are more prone to induce diseases and cause outbreaks. It is noteworthy that strains isolated from children with diarrhea of unknown etiology, not related to antibiotic use, belong to the "virulent" group 2; strains from leukemic patients showed a variety of different patterns, and only two belong to group 2. This characterization can be used to aid studies on the virulence and clinical significance of C. difficile.
Immunofluorescence as an adjunct to the histopathologic diagnosis of Chagas' disease
Authors: Chandler F W , Watts J C
Published: January 2020

We have developed a new indirect immunofluorescence procedure for identifying Trypanosoma cruzi amastigotes in sections of Formalin-fixed, paraffin-embedded tissue pretreated with a 0.25% trypsin solution to enhance immunofluorescence. In sections of human and mouse myocardia infected with T. cruzi and stained by this procedure, both intact amastigotes and phagocytosed amorphous antigen were intensely fluorescent and easily detected; nonspecific background fluorescence was absent or minimal. No staining occurred in similarly treated sections of Formalin-fixed, paraffin-embedded tissue that contained Histoplasma capsulatum var. capsulatum, Toxoplasma gondii, or Leishmania donovani to control specificity. Because pathology laboratories usually receive Formalin-fixed tissues for evaluation, this rapid and reliable procedure can be used to extend the diagnostic capability of conventional histopathology.
Conventional tube cell culture compared with centrifugal inoculation of MRC-5 cells and staining with monoclonal antibodies for detection of herpes simplex virus in clinical specimens
Authors: Woods G L , Mills R D
Published: January 2020

During a 15-month period, two methods for detection of herpes simplex virus (HSV) in 699 clinical specimens were compared: (i) 24-well-plate centrifugation (24WPC) with MRC-5 cells and staining with type-specific monoclonal antibodies (Syva Co., Palo Alto, Calif.) after incubation for 16 to 18 h and (ii) conventional tube cell culture with primary rabbit kidney and A549 cells. HSV was identified by conventional tube cell culture in 165 (24%) of 699 specimens and by the 24WPC method in 116 (17%) of 699 specimens. One specimen was positive for HSV by the 24WPC method alone, compared with 50 specimens positive only by conventional cell culture (P less than 0.0001). The sensitivity, specificity, and positive and negative predictive values of the 24WPC technique with MRC-5 cells for detection of HSV in clinical specimens were 70, 99.8, 99, and 91%, respectively. Centrifugal inoculation of MRC-5 cells in 24-well plates and staining with monoclonal antibodies after incubation for 16 to 18 h is an insensitive means of detecting HSV in clinical specimens and should not replace conventional tube cell culture with primary rabbit kidney cells.
Enzymatic characterization of Pseudomonas cepacia by API ZYM profile
Authors: Poh C L , Loh G K
Published: January 2020

The enzymatic activities of 53 strains of Pseudomonas cepacia were determined by using the API ZYM system. Strong alkaline phosphatase, acid phosphatase, butyrate esterase, caprylate esterase, myristate lipase, leucine arylamidase, and phosphoamidase activities were consistently detected in all strains. Weak activities were observed for valine arylamidase, beta-glucosidase, and N-acetyl-beta-glucosaminidase. No activities could be demonstrated for cystine arylamidase, trypsin, chymotrypsin, alpha-galactosidase, beta-galactosidase, beta-glucuronidase, alpha-glucosidase, alpha-mannosidase, and alpha-fucosidase. Enzymatic activities of pseudomonads may provide useful information about their pathogenesis and information for identification of Pseudomonas species.
Detection of respiratory syncytial virus and rotavirus by enhanced chemiluminescence enzyme-linked immunosorbent assay
Authors: Hornsleth A , Aaen K , Gundestrup M
Published: January 2020

The horseradish peroxidase-catalyzed oxidation of luminol was used in a chemiluminescence avidin-biotin enzyme-linked immunosorbent assay (CL-ABE) to detect respiratory syncytial virus (RSV) and rotavirus (ROV). This CL-ABE was carried out in a new apparatus constructed for the photographic registration of the light emission produced. When measured in a spectrophotometer, the light emission produced by the oxidation of luminol showed a peak emission at 425 nm. The chemiluminescence output reached maximum within 1 min after the initiation of luminol oxidation and diminished to one-half of maximum emission within 8 min. When titrations of purified ROV by avidin-biotin enzyme-linked immunosorbent assay (ABE) were monitored by CL-ABE and by conventional orthophenylenediamine (OPD) staining (OPD-ABE), the detection limits were 0.01 and 0.04 ng of ROV protein, respectively. Similar titrations of purified RSV gave detection limits of 0.2 and 0.8 ng of RSV protein by CL-ABE and OPD-ABE, respectively. When 26 RSV-positive samples of nasopharyngeal secretions (NPS) were titrated by CL-ABE and by OPD-ABE, the mean titers obtained were 737 and 254, respectively. When 19 ROV-positive fecal samples were titrated by CL-ABE and by OPD-ABE, the mean titers obtained were 82,000 and 29,000, respectively. When samples of NPS from 123 infants and children with acute lower respiratory disease were tested for the presence of RSV, 31 NPS samples were RSV positive by CL-ABE, and 29 of these 31 NPS samples were RSV positive by OPD-ABE.
Immunoblot analysis of immunoglobulin G response to the Lyme disease agent (Borrelia burgdorferi) in experimentally and naturally exposed dogs
Authors: Greene R T , Walker R L , Nicholson W L , Heidner H W , Levine J F , Burgess E C , Wyand M , Breitschwerdt E B , Berkhoff H A
Published: January 2020

Immunoblots were used to study the immunoglobulin G response to Borrelia burgdorferi in experimentally and naturally exposed dogs. Adsorption studies confirmed that the antibodies were specific for B. burgdorferi. Experimentally exposed dogs were asymptomatic. Naturally exposed dogs included both asymptomatic animals and animals showing signs compatible with Lyme disease. Naturally exposed dogs were from four geographic regions of the country. No differences were detected between immunoblot patterns of naturally exposed symptomatic or asymptomatic dogs from different areas of the country. The immunoblot patterns obtained with sera from experimentally exposed dogs were different from those obtained with sera from naturally exposed dogs and were characterized by reactivity to fewer and different protein bands. Immunoblot analysis using an OspA-protein-producing Escherichia coli recombinant showed that experimentally exposed dogs produced antibodies to OspA, whereas naturally exposed dogs did not. Modifications of the immune response over time, different routes of antigen presentation, and strain variation are factors postulated to account for the observed differences.
Immunochemical diversity of the major outer membrane protein of avian and mammalian Chlamydia psittaci
Authors: Fukushi H , Hirai K
Published: January 2020

Immunochemical properties of the major outer membrane protein (MOMP) of 16 strains of Chlamydia psittaci isolated from psittacine birds, budgerigars, a pigeon, turkeys, humans, cats, a muskrat, sheep, and cattle and a strain of C. trachomatis, L2/434/Bu, were compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by immunoblotting analysis with hyperimmunized rabbit antisera to strains of parrot, turkey, feline, and bovine origin. The MOMPs of the strains showed variation in molecular weights and immunological specificities. Fifteen of the C. psittaci strains were classified into two avian and two mammalian types based on immunological specificity of the MOMP, whereas the other strain was not classified in this study. Immunological classification based on specificity of the MOMP by immunoblotting proved to be a valuable method to classify various strains of C. psittaci.
Disk diffusion susceptibility testing for LY163892 (KT-3777), a new orally administered 1-carbacephem
Authors: Jones R N , Barry A L
Published: January 2020

LY163892, a new orally administered 1-carbacephem, was found to have a spectrum of antimicrobial activity very similar to that of cefaclor. Diffusion tests with 30-micrograms LY163892 disks produced acceptable interpretive error rates with greater than or equal to 22 mm as the susceptibility zone diameter. This was required to reduce potential false-susceptibility results, particularly among Enterobacter spp. and Providencia stuartii: both species included strains that produce beta-lactamases capable of hydrolyzing Ly163892. Preliminary recommendations for LY163892 disk tests are presented, but the continued use of the 30-micrograms cephalothin "class representative" disk might be the best procedure to minimize LY163892 interpretive errors for clinical trials. A separate LY163892 disk for testing Haemophilus influenzae strains should be seriously considered.
Modified toluidine blue O stain for Pneumocystis carinii: further evaluation of some technical factors
Authors: Witebsky F G , Andrews J W , Gill V J , MacLowry J D
Published: January 2020

A modified toluidine blue O (TBO) stain for Pneumocystis carinii cysts was evaluated with regard to the influence of (i) the age and extent of use of the sulfation reagent, (ii) the source of TBO, (iii) the TBO content of the staining solution, and (iv) the amount of TBO present in the alcohol wash solutions. All TBOs evaluated, except for a new TBO obtained from Roboz Surgical Instrument Co., Inc., Washington, D.C., produced satisfactory results. Each lot of TBO should be quality controlled before use to ensure that the P. carinii cysts stain lavender against a blue background. We have ourselves decided to use only certified TBO with a high dye content. As extensively used sulfation reagent provided less satisfactory results than did either freshly prepared or 1-week-old unused sulfation reagent, we have decided to prepare fresh sulfation reagent at least weekly and to discard used sulfation reagent after 10 slides have been processed.
Establishment by enzyme-linked immunosorbent assay of seronegative range for herpes simplex virus and cytomegalovirus antibodies and evaluation of heterologous responses to live varicella vaccine
Authors: Gong A K , Lipton S V , Brunell P A
Published: January 2020

Cord serum samples treated with staphylococcus protein A and an immune affinity column to remove immunoglobulin G were used to establish a seronegative range for herpes simplex virus and cytomegalovirus. No seroconversions or increased heterologous antibody levels to herpes simplex virus or cytomegalovirus were found in live varicella vaccine recipients.
Evaluation of a latex agglutination test for herpes simplex virus
Authors: Storch G A , Reed C A , Dalu Z A
Published: January 2020

We evaluated a new commercial latex agglutination test for herpes simplex virus antigen detection (Virogen Herpes Slide Test, Wampole Laboratories, Cranbury, N.J.). In testing of eluates from 100 lesion swabs, mostly from genital sites, the following test parameters were ascertained: sensitivity, 73%; specificity, 89%; positive predictive value, 89%; negative predictive value, 72%. Testing was also performed on 160 supernatants from 153 cell cultures inoculated with clinical samples. In this application, sensitivity and specificity were each 100%, provided supernatants were sampled for testing when the cytopathic effect involved at least 25% of the cell monolayer.
Enrichment for Plesiomonas shigelloides from stools
Authors: Rahim Z , Kay B A
Published: January 2020

Bile peptone broth and alkaline peptone water (pH 8.5) were examined as enrichment media for the isolation of Plesiomonas shigelloides from stools, with salmonella-shigella agar as the isolation medium. After 423 parallel examinations in two different experiments, bile peptone broth enrichment for 24 h was observed to be six times more effective (P less than 0.01) than direct plating alone on salmonella-shigella agar. Bile peptone broth was found to be twice as effective as alkaline peptone water for the recovery of P. shigelloides from stools.
Comparison of 17 genome types of adenovirus type 3 identified among strains recovered from six continents
Authors: Li Q G , Wadell G
Published: January 2020

Restriction endonucleases BamHI, BclI, BglI, BglII, BstEII, EcoRI, HindIII, HpaI, SalI, SmalI, XbalI, and XholI were used to analyze 61 selected strains of adenovirus type 3 (Ad3) isolated from Africa, Asia, Australia, Europe, North America, and South America. It was noted that the use of BamHI, BclI, BglII, HpaI, SalI, and SmaI was sufficient to distinguish 17 genome types; 13 of them were newly identified. All 17 Ad3 genome types could be divided into three genomic clusters. Genome types of Ad3 cluster 1 occurred in Africa, Europe, South America, and North America. Genomic cluster 2 was identified in Africa; genomic cluster 3 was identified in Africa, Asia, Australia, Europe (a few), and North America. This was of interest because 15 identified genome types of Ad7 could also be divided into three genomic clusters. The degree of genetic relatedness between the 17 Ad3 and the 15 Ad7 genome types was analyzed and was expressed in a three-dimensional model.
Common epitope on the lipopolysaccharide of Legionella pneumophila recognized by a monoclonal antibody
Authors: Barthe C , Joly J R , Ramsay D , Boissinot M , Benhamou N
Published: January 2020

Serogroup-specificity of Legionella pneumophila is related to lipopolysaccharide (LPS), and few cross-reactions between serogroups have been observed with rabbit or monkey antisera. C57BL/6 mice were sequentially immunized with crude outer membrane fractions of L. pneumophila serogroups 1, 5, and 7, Legionella bozemanii, and Legionella micdadei. Spleen cells from these mice were then fused with the Sp2-0/Ag14 mouse myeloma cell line. Outer membrane-rich fractions and LPS were prepared from L. pneumophila serogroups 1 to 8 and other Legionella and non-Legionella species. Immunoblots of these extracts were performed with monoclonal antibody obtained from these fusions. One of these monoclonal antibodies recognized an epitope common to all tested serogroups of L. pneumophila and attached to the major constituent of the outer membrane, LPS. This antibody did not react with other Legionella species and numerous gram-negative rods other than Pseudomonas fluorescens CDC93. This monoclonal antibody may be useful in preliminary identification of L. pneumophila as an alternative to direct fluorescent-antibody testing.
Evaluation of a new latex agglutination method for detection of antibody to herpes simplex virus
Authors: DeGirolami P C , Dakos J , Eichelberger K , Biano S
Published: January 2020

A new latex agglutination (LA) test (Wampole Laboratories, Cranbury, N.J.) for detection of antibody to herpes simplex virus was compared with a reference complement fixation (CF) method in a premarket evaluation. Of 102 serum samples tested, 19 were LA negative and CF negative, 79 were LA positive and CF positive, and 4 were LA positive and CF negative. An enzyme immunoassay (M. A. Bioproducts, Walkersville, Md.) performed on the four LA-positive and CF-negative serum samples agreed with LA in all cases. Most LA titers were two to four doubling dilutions higher than CF titers. We conclude that this new LA test is a rapid, sensitive, and simple method for documentation of past infection with herpes simplex virus.
Use of A-549 cells in a clinical virology laboratory
Authors: Woods G L , Young A
Published: January 2020

A-549 cells were compared with other cell lines for virus recovery, except from specimens submitted specifically for detection of cytomegalovirus. Of 589 specimens submitted specifically for detection of herpes simplex virus (HSV), 163 (28%) were positive for HSV--159 (97.5%) in A-549 cells and 156 (96%) in primary rabbit kidney cells. HSV cytopathic effect was identified an average of 0.6 day earlier in A-549 cells. Virus was recovered from 194 (11%) of 1,790 specimens submitted for general virus isolation. Of 40 HSV isolates, 85% were positive in A-549 cells, 72.5% were positive in MRC-5/WI-38 cells, and 42.5% were positive in HEp-2 cells. With adenovirus, 96% of 45 isolates were detected in A-549 cells, 62% were detected in HEp-2 cells, 38% were detected in MRC-5/WI-38 cells, and 31% were detected in PMK cells. Of the 76 enterovirus-positive specimens, 71% were positive in PMK cells, 62% were positive in A-549 cells, and 62% were positive in MRC-5/WI-38 cells. None of 12 respiratory syncytial virus, 14 rhinovirus, or 7 influenza A virus isolates were detected in A-549 cells. Of the cell lines examined, A-549 cells performed optimally for recovery of HSV and adenovirus, they allowed good growth of many of the enterovirus isolates, but they did not allow recovery of any of the respiratory syncytial virus, rhinovirus, or influenza A virus isolates.
Rat model for human cryptosporidiosis
Authors: Brasseur P , Lemeteil D , Ballet J J
Published: January 2020

Effective treatment for Cryptosporidium infection in immunocompromised patients has yet to be found. We report a rodent model of persistent Cryptosporidium infection. Sprague-Dawley rats were injected subcutaneously twice a week for 8 weeks with 25 mg of hydrocortisone acetate. Fed a regular low-protein diet for 9 weeks, they were challenged once with 10(5) calf Cryptosporidium oocysts 5 weeks after the start of the hydrocortisone acetate regimen. Oocyst shedding was evaluated in feces daily by using a carbolfuchsin-staining method. Rats shed oocysts from days 2 to 9 after ingestion and developed a persistent infection for more than 38 days. Excretion was lower after subsequent parasite challenges, suggesting that a degree of protection developed progressively. The results suggest that this experimental model provides a procedure for screening candidate therapeutic agents.
Differential quantitation with a commercial blood culture tube for diagnosis of catheter-related infection
Authors: Flynn P M , Shenep J L , Barrett F F
Published: January 2020

Central-venous-catheter-related infection is readily diagnosed by comparing simultaneous quantitative cultures of blood samples obtained via the catheter and a peripheral vein. The DuPont Isolator 1.5 (Du Pont Co., Wilmington, Del.) microbial culture tube was evaluated as an aid in diagnosing catheter-related bacteremia and fungemia in children and was found to be a reliable and convenient laboratory device for determining whether a long-term central venous catheter is a focus of infection.
Rapid characterization of oral and nonoral pigmented Bacteroides species with the ATB Anaerobes ID system
Authors: van Winkelhoff A J , Clement M , de Graaff J
Published: January 2020

The ATB Anaerobes ID system (API SYSTEM, La Balme Les Grottes, France) was evaluated for its ability to differentiate between species of the pigmented Bacteroides group. This identification system is based on the degradation of chromogenic substrates in combination with sugar fermentation reactions. The results showed that the ATB system can be useful for differentiation between the 10 pigmented Bacteroides species. However, additional tests may be necessary.
Factors affecting viability and growth in HeLa 229 cells of Chlamydia sp. strain TWAR
Authors: Kuo C C , Grayston J T
Published: January 2020

Two prototype isolates (TW-183 and AR-39) of Chlamydia sp. strain TWAR were used to study factors affecting growth of this organism in HeLa 229 cells. The results showed that an incubation temperature of 35 degrees C was better than one of 37 degrees C for growth. The burst size after 3 days of incubation at 35 degrees C was found to be small (13 to 52), which partially explains the difficulty of serial passage in cell culture. Application of a higher centrifugal force (1,700 X g versus 900 X g) at the time of inoculation enhanced growth 2.2 to 3.6 times. Infectivity was enhanced by treatment of cells with DEAE-dextran (2.4 times) or poly-L-lysine (1.6 times), but not with Polybrene or polyethylene glycol. The viability of the TWAR organism in chlamydia transport medium SPG was also studied. It was shown that the organism was rapidly inactivated at room temperature (22 degrees C); only 1% remained viable after storage for 24 h. The viability was preserved at 4 degrees C, and 70% remained viable after storage for 24 h. Freezing at -75 degrees C inactivated 23% of the organisms when the organisms were frozen within 4 h after harvesting and stored at 4 degrees C before freezing.
Comparative immunochemistry of lipopolysaccharides from typable and polyagglutinable Pseudomonas aeruginosa strains isolated from patients with cystic fibrosis
Authors: Fomsgaard A , Conrad R S , Galanos C , Shand G H , Høiby N
Published: January 2020

Lipopolysaccharide (LPS) was extracted and purified from three Pseudomonas aeruginosa strains isolated from the infected lungs of patients with cystic fibrosis. Two of the strains could be typed by O-specific antibody (O:3 and O:9), and the third was polyagglutinable (O:3/9). The separated LPS was characterized by chemical and serological methods. The main neutral sugar constituents (glucose, rhamnose, and heptose) were found in various proportions in the three strains, whereas the amounts of glucosamine, galactosamine, ketodeoxyoctonate, and phosphate were more constant. Ester-bound C12, C16, 3-OH-C10, and 2-OH-C12, together with amide-bound 3-OH-C12, fatty acids were present in equimolar proportions in all three strains. Considerable amounts of LPS were liberated in the culture supernatant of the O:3 bacteria but not in those from the other two strains. This free LPS was shown to be immunologically identical to the cell-bound LPS and the extracted LPS. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis, O:3 and O:9 LPS showed a ladder pattern characteristic of smooth LPS, while O:3/9 LPS appeared rough. Rabbit antisera used for O-typing were found by enzyme-linked immunosorbent assay to contain anti-LPS antibodies that reacted strongly with homologous LPS, moderately with O:3/9 LPS, and slightly with heterologous LPS. Immunoblotting showed that common antigenic determinants in the core-lipid A part were involved in the observed cross-reaction. The polyagglutinability of P. aeruginosa may be explained by the antibodies to these common determinants that arose from the partial absence of O polysaccharides.
Congo red as a fluorochrome for the rapid detection of fungi
Authors: Slifkin M , Cumbie R
Published: January 2020

Congo red may be applied as a fluorochrome to rapidly detect fungi in clinical specimens, tissue, and fungal culture preparations. This generally available stain is cost effective and simple to prepare. The stain may be prepared with potassium permanganate as a counterstain or with Formalin or glutaraldehyde as a fungicide.
Characterization of urease from Campylobacter pylori
Authors: Mobley H L , Cortesia M J , Rosenthal L E , Jones B D
Published: January 2020

Campylobacter pylori, a suspected agent of gastritis and peptic ulceration, rapidly hydrolyzes urea. Because urease serves as the basis of detection of the organism in gastric biopsies and may represent an important virulence factor, biochemical characteristics of the enzyme were determined. C. pylori was isolated from antral biopsies from 10 patients with complaints of abdominal pain or history of peptic ulcer disease. All isolates were urease positive, with an average rate of hydrolysis by cell lysates being 36 +/- 28 mumol of NH3 per min per mg of protein, more than twice that of Proteus mirabilis and 10 times that of other urinary tract isolates. The enzyme had an apparent molecular weight of 625,000 +/- 15,000 by column chromatography, an isoelectric point of 5.9, a Km of 0.8 +/- 0.1 mM urea, an optimal temperature of 45 degrees C, and an optimal pH of 8.2. Ten isolates tested produced ureases with identical electrophoretic mobilities on nondenaturing 5% polyacrylamide activity gels. Acetohydroxamic acid (100 micrograms/ml), hydroxyurea (85 micrograms/ml), flurofamide (0.05 micrograms/ml), and EDTA (8 mM) inhibited enzyme activity by 50%. Cell lysates retained 50% of initial urease activity after 6 days and 40% activity after 18 days when stored at 4 degrees C in 20 mM sodium phosphate, pH 6.8. At -70 degrees C for 18 days, 1 mM EDTA or 15% glycerol preserved 40 or 34%, respectively, of initial activity. The urease of C. pylori appears to be biochemically unique from the enzymes of other common urease-producing species.
Sputum gram stain assessment in community-acquired bacteremic pneumonia
Authors: Gleckman R , DeVita J , Hibert D , Pelletier C , Martin R
Published: January 2020

A prospective study was performed over a 4.5-year period to determine the ability of a sputum Gram stain to predict the cause of community-acquired bacterial pneumonia. A blood culture isolate, rather than a sputum culture, served as the reference standard to provide precise identification of the etiologic agent. The study population comprised 59 bacteremic adults who expectorated a valid sputum sample. Data are presented that indicate that a physician, aided by the morphology of the stained sputum, could theoretically select appropriate monotherapy approximately 94% of the time when selective, defined criteria for the microbiology of valid sputum are met. Three of the five patients with pneumonia caused by Haemophilus influenzae, however, had sputum stains that suggested alternative pathogens. This study reaffirms that the Gram-stained sputum is a reliable, but not infallible, guide to direct initial antibiotic therapy in adults with community-acquired bacterial pneumonia.
Specific immunoglobulin A to Bordetella pertussis antigens in mucosal secretion for rapid diagnosis of whooping cough
Authors: Granström G , Askelöf P , Granström M
Published: January 2020

Specific immunoglobulin A (IgA) to Bordetella pertussis filamentous hemagglutinin (FHA) and pertussis toxin (PT) was determined in mucosal secretions by an enzyme-linked immunosorbent assay (ELISA). It took 3 to 4 h to complete the ELISA. The upper limits of normal values for age were determined in nasopharyngeal (NPH) secretions from 23 patients with viral infections and in 10 healthy adults working with pertussis patients or cultures. A significant IgA response to FHA was found in 38 of 54 (70%) and to PT in 28 of 54 (52%) NPH secretions from patients with pertussis confirmed by culture, serology, or both. The rate of positive responses to either antigen (44 of 54 [81%]) was significantly higher than that by culture alone (29 of 54 [54%]; P less than 0.01). The rate of positive responses increased from 65% in patients with symptoms for 1 week or less to 87 to 92% in patients with symptoms for 2 or more weeks. The specific IgA response to PT was found in 100% of NPH samples from 17 unimmunized children less than 3 years of age and in only 30% of adults and immunized children greater than 3 years of age. A response to FHA was found in 65 to 73% of the NPH secretions in all age groups. Saliva samples were found to contain specific IgA to FHA and PT in all age groups, but these were of diagnostic value in 50% (11 of 22) of the adult patients. The specificity of the ELISA was 100% (10 of 10 negatives) in NPH secretions from patients with pertussis-like cough who had negative cultures and serology. The results indicate that determination of specific IgA to PT and FHA in NPH aspirates represents a sensitive and rapid diagnostic method for the detection of pertussis.
Virulence factors in Escherichia coli strains isolated from Swedish piglets with diarrhea
Authors: Söderlind O , Thafvelin B , Möllby R
Published: January 2020

Parenteral vaccination of sows against Escherichia coli diarrhea in their newborn piglets has become more common during the last decade in Sweden, and the vaccination has generally had positive effects. For more than 20 years we have investigated E. coli strains isolated from piglets and weaned pigs with enteric disorders, noting the presence of O groups, enterotoxins, and adhesins. There has been a continuous change in the frequency of these virulence factors. The present study was performed during 1983 and 1984 to follow this change, since such information is essential for the proper choice of vaccines. A total of 856 E. coli strains were obtained from 683 herds divided into three age groups: 1 to 6 days old, 1 to 6 weeks old, and weaned pigs. O group 149 still dominated in the last two age groups, while O group 101 was, for the first time, the most frequent O group in neonatal piglets. All but four O149 strains carried the K88 antigen, which was found in only one other strain (O group 8). K99 antigen was most often found in O groups 101 and 64, and among all the K99 strains ST mouse was the most common (44 of 57), followed by ST mouse-ST pig strains (12 of 57). The 987P antigen was demonstrated in 26 strains belonging to O groups 141 and OX46 and nontypable strains. Two strains belonging to O group 101 were positive for F41 antigen; one of them also carried the K99 antigen. Among all non-O149 strains, ST mouse was the most common type of enterotoxigenic E. coli ( n = 88), followed in decreasing order by ST mouse-ST pig strains ( n = 69) and ST pig strains ( n = 33). In 114 strains producing enterotoxins no adhesive factor was found. Thus, vaccination of the Swedish sow population for more than 5 years with vaccines containing O149 and K88 antigens has apparently changed the pattern of enterotoxigenic E. coli in neonatal diarrhea. The frequency of O149:K88 strains has been reduced, and O101:K99:ST mouse strains now dominate. However, O149 strains remain the dominant O group in piglets older than 1 week. In spite of all our diagnostic efforts, no virulence factors were detected in about one third of the piglets and weaned pigs with enteric disorders.
Local and systemic antibody responses in high-risk adults given live-attenuated and inactivated influenza A virus vaccines
Authors: Gorse G J , Belshe R B , Munn N J
Published: January 2020

Forty seropositive older adults with chronic diseases were vaccinated intranasally with either influenza A/California/10/78 (H1N1) (CR37) or influenza A/Washington/897/80 (H3N2) (CR48) virus. No clinically significant decrements in pulmonary function occurred postvaccination. Eight (62%) recipients of CR37 virus and 16 (59%) recipients of CR48 virus became infected with vaccine virus, as indicated by a fourfold rise in nasal wash immunoglobulin G (IgG) or IgA antibody titer, a fourfold rise in serum antibody titer, isolation of vaccine virus from nasal washings, or all of these. Within 2 years after cold-recombinant virus vaccination, 29 vaccinees received trivalent inactivated influenza virus vaccine parenterally. After inactivated virus vaccination, 23 (79%) vaccinees developed a fourfold rise in nasal wash or serum antibody titer to H1 antigen and 24 (83%) developed a fourfold rise in nasal wash or serum antibody titer to H3 antigen. Significantly more cold-recombinant virus vaccinees developed a fourfold rise in nasal wash IgA antibody to H1 or H3 hemagglutinin compared with inactivated virus vaccinees (17 [43%] versus 9 [17%], P = 0.01). We conclude that these cold-recombinant virus vaccines are safe and immunogenic in seropositive older high-risk adults and more often induced a nasal wash IgA antibody response than the inactivated virus vaccine.
Pathogenicity of rotavirus in rabbits
Authors: Thouless M E , DiGiacomo R F , Deeb B J , Howard H
Published: January 2020

The role of rotavirus in diarrheal disease of rabbits was investigated, and a model for human rotavirus infection was established. Orogastric inoculation of 8- and 12-week-old New Zealand White rabbits with a rabbit strain of rotavirus (L:ALA:84) resulted in fecal shedding of virus for 6 to 8 days from 2 to 5 days after inoculation. Most rabbits exhibited diarrhea, coincident with the onset of viral shedding, which persisted for 2 to 4 days. Diarrhea was characterized by soft or fluid stools and fecal staining of the perineum. Inoculation of 3-week-old rabbits resulted in a briefer period of viral shedding and diarrhea of a milder nature. Histopathologic examination during the period of viral shedding revealed a mild, nonsuppurative enteritis. Inoculated rabbits exhibited antibodies in serum to rotavirus by enzyme-linked immunosorbent assay. Sham-inoculated or uninoculated rabbits maintained in the same cage or the same room with inoculated rabbits acquired rotavirus infection. The mild diarrheal disease which resulted with a rotavirus isolate from severe field cases suggests that cofactors were involved.