bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical and microbiologic characteristics of pediococci
Authors: Riebel W J , Washington J A
Published: January 2020

Over a 43-month period, 23 separate isolates of nonenterococcal alpha- and nonhemolytic streptococci were reported by our clinical microbiology laboratory to be resistant to vancomycin. This constituted 0.32% of nonenterococcal alpha- and nonhemolytic streptococci reported and 4.4% of such streptococci upon which susceptibility testing was performed. Of 13 isolates which were available for further study, all were highly resistant to vancomycin (MIC greater than or equal to 1,024 micrograms/ml), but none were actually streptococci. Three were clearly gram-positive rods by Gram stain and were found to be homofermentative lactobacilli. Two strains with elongated gram-positive cocci from colonies on agar showed small gram-positive rods when grown in thioglycolate broth and were physiologically identified as Lactobacillus confusus. Two isolates with lenticular gram-positive cocci appeared to be Leuconostoc mesenteroides subsp. mesenteroides. Six gram-positive isolates with round cells from growth on agar and from broth were arranged in tetrads in broth and closely resembled Pediococcus acidilactici. Twelve additional strains of pediococci that were not of human origin were also found to be highly resistant to vancomycin. These findings confirm published reports of clinical isolation of organisms resembling pediococci and suggest that clinically isolated, vancomycin-resistant bacteria which superficially resemble streptococci are probably other lactic acid bacteria.
Large-scale screening of human sera with cytomegalovirus recombinant antigens
Authors: Landini M P , Guan M X , Jahn G , Lindenmaier W , Mach M , Ripalti A , Necker A , Lazzarotto T , Plachter B
Published: January 2020

One of the major problems regarding cytomegalovirus (CMV) serodiagnosis is the use of poorly defined viral antigens. Individual CMV proteins expressed via recombinant DNA procedures are a promising approach to solving this problem. In this work, 10 different fusion proteins containing antigenic epitopes of the major CMV structural proteins of 150, 71, 65, 38, and 28 kilodaltons and of the nonstructural protein of 52 kilodaltons were subjected to Western (immuno-) blotting to assay their reactivities with immunoglobulins G and M in 395 CMV-seropositive and 100 CMV-seronegative unselected human serum samples. As a whole, the results obtained indicate that CMV can be replaced by recombinant viral proteins in the serological evaluation of anti-CMV antibodies.
Description of a medium for isolating Anaerobiospirillum spp., a possible cause of zoonotic disease, from diarrheal feces and blood of humans and use of the medium in a survey of human, canine, and feline feces
Authors: Malnick H , Williams K , Phil-Ebosie J , Levy A S
Published: January 2020

Anaerobiospirillum spp., motile, spiral anaerobic bacteria, have been implicated as a cause of diarrhea and bacteremia in humans. Anaerobiospirillumlike organisms and Anaerobiospirillum succiniciproducens were reported from 17 cases of diarrhea. Sixteen of the patients did not have any underlying disorders and recovered from the infection; the other one, who had a heart defect, did not. The formulation of a selective medium for Anaerobiospirillum spp. has enabled a survey of human, cat, and dog feces as possible sources for these anaerobic bacteria. Anaerobiospirillum spp. were not isolated from 527 "normal" human feces but were found in both cat and dog feces. We also describe biochemical tests and API ZYM results of A. succiniciproducens and anaerobiospirillumlike organisms.
Detection of hepatitis B virus DNA in serum by polymerase chain reaction amplification and microtiter sandwich hybridization
Authors: Keller G H , Huang D P , Shih J W , Manak M M
Published: January 2020

We have developed a microtiter sandwich hybridization assay for the detection of polymerase chain reaction (PCR)-amplified hepatitis B virus (HBV) sequences. This assay utilizes an enzyme-linked immunosorbent assay-like format in which cloned DNA containing a sequence complementary to half of one PCR product strand is immobilized in microtiter wells. A biotin-labeled DNA sequence complementary to the other portion of the same PCR product strand is used as the probe. The DNAs from 69 hepatitis B surface antigen-positive serum samples and 16 antigen-negative control samples were amplified by the PCR procedure, and the product was detected by Southern and sandwich hybridization. Both detection procedures were capable of detecting as few as five copies of HBV DNA. Compared with Southern hybridization, the sandwich hybridization assay exhibited a sensitivity of 100% and a specificity of 95% for the detection of amplified HBV sequences. Unlike Southern hybridization, however, the sandwich hybridization assay employs a nonradioactive probe and allows easy handling of large numbers of samples. DNA was detected in 74% of the antigen-positive samples. All of the antigen-negative samples (healthy blood donors) were negative for HBV DNA by both procedures.
Comparison of Kodak Surecell Chlamydia Test Kit with culture for the diagnosis of chlamydial conjunctivitis in infants
Authors: Hammerschlag M R , Gelling M , Roblin P M , Worku M
Published: January 2020

The accuracy of the Surecell Chlamydia Test Kit (Kodak Clinical Products, Rochester, N.Y.) in detecting neonatal conjunctival infection caused by Chlamydia trachomatis was determined by comparison of this enzyme immunoassay with the isolation of C. trachomatis in tissue culture. Kodak Surecell is a rapid monoclonal antibody-based membrane capture enzyme immunoassay which can be processed in the office of a physician. The sensitivity and specificity compared to culture in detecting C. trachomatis in conjunctival specimens from infants with conjunctivitis were 93 and 96%, respectively. The test does not require specialized equipment or trained personnel and would be ideal for physicians who see low numbers of infants with possible chlamydial conjunctivitis in their offices.
Evaluation of the LOGIC system for the rapid identification of members of the family Enterobacteriaceae in the clinical microbiology laboratory
Authors: Pattyn S R , Sion J P , Verhoeven J
Published: January 2020

The LOGIC identification system (J.D. Perry, M. Ford, N. Hjersing, and F.K. Gould, J. Clin. Pathol. 41: 1010-1012, 1988) for gram-negative rods, performed with microdilution plates instead of tubes, was evaluated for strains isolated from all tested specimens except those obtained from stools (for which a different strategy was followed). Systematically extended with the oxidase test and lactose fermentation, it proved to be very reliable and extremely simple and economical.
Engyodontium album endocarditis
Authors: Augustinsky J , Kammeyer P , Husain A , deHoog G S , Libertin C R
Published: January 2020

This is the first reported case of native valve endocarditis caused by Engyodontium album. This fungus, rarely seen as a human pathogen, is separated from Tritirachium species by its lack of pigmentation and from Beauveria species by the presence of conidiogenous cells in whorls.
Quantitative immunoassay of Treponema denticola serovar C in adult periodontitis
Authors: Simonson L G , Goodman C H , Morton H E
Published: January 2020

Murine monoclonal antibodies specific for Treponema denticola serovar C were produced and characterized in this study. An immunoassay was then developed by using these monoclonal antibodies, and the T. denticola serovar C antigen content of subgingival plaque was quantitated for samples taken from patients with periodontitis and healthy volunteers. The human subgingival plaque samples were grouped by severity of disease and pocket depth measurements at the collection site. The T. denticola serovar C content per milligram of subgingival plaque from deep pockets (greater than 6 mm) of patients with severe periodontitis was found to be twice that of samples collected from deep pockets (4 to 6 mm) of patients with moderate periodontitis or samples collected from healthy subjects (pocket depth, less than 4 mm).
Reproducibility of interpretation of Gram-stained vaginal smears for the diagnosis of bacterial vaginosis
Authors: Mazzulli T , Simor A E , Low D E
Published: January 2020

In the diagnostic microbiology laboratory, interpretation of Gram-stained slides of vaginal swab specimens is used to support the clinical diagnosis of bacterial vaginosis. The reproducibility with which technologists interpret these Gram-stained slides was evaluated by presenting, in coded fashion, 80 original slides and 80 duplicate slides of vaginal swab specimens to three technologists. They each interpreted the original slide twice and the duplicate slide from the same specimen once. Intraobserver and interobserver agreement was assessed by use of the weighted kappa statistic. Semiquantitation of Lactobacillus and Gardnerella morphotypes and a diagnosis of bacterial vaginosis showed the greatest intraobserver agreement, with kappa values ranging from 0.772 to 1.000. Interobserver agreement was also high for rating Lactobacillus morphotypes and clue cells (kappa values between 0.735 and 0.869) but decreased slightly for Gardnerella morphotypes and a diagnosis of bacterial vaginosis (kappa values between 0.656 and 0.800). These results indicate that there is good agreement for the interpretation of Gram-stained slides of vaginal swab specimens and that this method alone, without culture, can be used reliably to support the clinical diagnosis of bacterial vaginosis.
Oligonucleotide probes for detection and differentiation of Staphylococcus aureus strains containing genes for enterotoxins A, B, and C and toxic shock syndrome toxin 1
Authors: Neill R J , Fanning G R , Delahoz F , Wolff R , Gemski P
Published: January 2020

Different synthetic DNA nucleotide sequences were evaluated as gene probes for the specific detection and differentiation of Staphylococcus aureus strains encoding enterotoxins A (SEA), B (SEB), and C (SEC) and toxic shock syndrome toxin 1 (TSST-1). Identification of sequences unique to each toxin, based on knowledge of their nucleotide sequences, led to preparation of the specific 18-base oligonucleotide probes EA1 (encoding amino acids 177 to 182 of SEA), EB2 (encoding amino acids 105 to 110 of SEB), EC5 (encoding amino acids 125 to 131 of SEC1), and TS1 (encoding amino acids 160 to 166 of TSST-1). In colony blot hybridization analyses, these probes hybridized specifically with DNA from strains that produced the respective toxin serotypes. An excellent (greater than or equal to 93%) correlation between hybridization results (genotype) and toxin protein detection by an enzyme-linked immunosorbent assay (phenotype) was observed in the characterization of both reference and clinical strains of S. aureus for SEA, SEB, and TSST-1. A lower correlation (64%) for SEC reflected a lack of sensitivity in detecting toxin production. Our findings demonstrate that molecular DNA hybridization with synthetic oligonucleotide probes provides another approach for establishing the toxigenicity of S. aureus.
Use of an alkaline phosphatase-labeled synthetic oligonucleotide probe for detection of Campylobacter jejuni and Campylobacter coli
Authors: Olive D M , Johny M , Sethi S K
Published: January 2020

A commercially available synthetic nucleic acid probe (SNAP) conjugated to alkaline phosphatase was compared with standard culture techniques for detecting Campylobacter species. The SNAP was able to detect either 5 ng of C. jejuni DNA or 10(5) CFU of bacteria. The SNAP could also detect DNA extracted from 10(5) CFU in mock-infected stool samples. The SNAP detected C. jejuni and C. coli but showed no reactivity with C. laridis, C. fetus subsp. fetus, C. fetus subsp. venerealis, C. fennelliae, "C. upsaliensis," C. cinaedii, C. fecalis, C. hyointestinalis, C. mucosalis, or Helicobacter (Campylobacter) pylori. The SNAP also showed no cross-reactivity with other enteric pathogens. When applied to pure cultures, the SNAP detected 55 clinical isolates of C. jejuni and 11 clinical isolates of C. coli, with an accuracy of 100%. When applied directly to clinical specimens, the SNAP detected Campylobacter spp. in 19 of 23 culture-positive stool specimens (sensitivity, 82.6%; specificity, 100%). Pure cultures of the Campylobacter strains isolated from the four probe-negative, culture-positive stool specimens gave positive reactions with the SNAP. While the SNAP had excellent sensitivity and specificity for isolated bacterial colony isolates, the main limitation to the Campylobacter probe detection kit may be the sensitivity limit on direct detection of Campylobacter organisms in stools.
Production of bacteriolytic activity in the oral cavity by nutritionally variant streptococci
Authors: Pompei R , Caredda E , Piras V , Serra C , Pintus L
Published: January 2020

Microorganisms from the oral flora were examined for the production of bacteriolytic substances. Among human viridans group streptococci, only one group of strains with thiol-dependent properties was shown to secrete enzymes with bacteriolytic activity on heat-killed cells of Micrococcus luteus on double-layer nutrient agar plates. By morphology, culture requirements, and biochemical properties, they were found to conform to descriptions of nutritionally variant streptococci (NVS). Bacteriolytic activity was shown to be a constant property of all of the human oral NVS isolated and a property of some reference strains of NVS from clinical sources. No other known species of viridans group streptococci demonstrated bacteriolytic activity. Analysis of bacteriolytic activity could be a useful tool for both the isolation and identification of this fastidious group of microorganisms.
Evaluation of autoSCAN-W/A automated microbiology system for the identification of non-glucose-fermenting gram-negative bacilli
Authors: Tenover F C , Mizuki T S , Carlson L G
Published: January 2020

We evaluated the ability of the autoSCAN-W/A (MicroScan Division, Baxter Healthcare Corporation, West Sacramento, Calif.), in conjunction with the dried colorimetric Neg ID type 2 panel (DCP) and new rapid fluorometric Neg ID panel (RFP), to identify non-glucose-fermenting gram-negative bacilli by challenging the system with 310 previously identified reference strains. Of these 310 isolates, 286 organisms were in the DCP data base and 269 were in the RFP data base. Use of the DCP panels resulted in 118 (41.3%) correct and 64 (22.4%) incorrect first choice identifications at greater than or equal to 85% probability, 61 (21.3%) low-probability identifications, and 43 (15.0%) reports of unidentified organisms. The RFP system reported 135 (50.1%) correct and 25 (9.3%) incorrect identifications at greater than or equal to 85% probability and 109 (40.5%) low-probability identifications. Unidentified isolates (DCP system only) and isolates producing low-probability first choice identifications (both systems) required supplementary biochemical testing. Over half (37 of 64 [57.8%]) of the DCP misidentifications were due to four commonly isolated, saccharolytic organisms (Alcaligenes xylosoxidans subsp. xylosoxidans, Pseudomonas putida, Pseudomonas fluorescens, and Xanthomonas maltophilia), while 7 of 25 (28%) of misidentifications in the RFP system were due to P. fluorescens. Of note, the RFP system identified non-glucose-fermenting gram-negative bacilli within 2 h of panel inoculation, allowing additional conventional biochemical tests to be set up the same day on low-probability isolates, whereas only 13.5% of the DCPs could be read at 18 h, with the remainder requiring 42 h of incubation before reading. When organism identifications were recalculated with the updated RFP data base and revised software, only 8.1% of all 310 isolates were misidentified at greater than or equal to 85% probability while 77.1% of the isolates were now correctly reported at this same high probability.
Bacteremia and subcutaneous abscess caused by Proteus penneri in a neutropenic host
Authors: Engler H D , Troy K , Bottone E J
Published: January 2020

Proteus penneri bacteremia and concomitant subcutaneous infection developed in a neutropenic patient with acute lymphocytic leukemia. The skin infection occurred while the patient was being treated empirically with cefoperazone and metronidazole. This case demonstrates the invasive potential of this microorganism in the proper setting.
Ortho enzyme immunoassay versus McCoy cell monolayers stained by iodine or fluorescent antibody for detection of Chlamydia trachomatis
Authors: Phillips L E , Smith P B , Riddle G D , Faro S , Goodrich H K , Martens M G
Published: January 2020

We compared a new enzyme immunoassay (Ortho Diagnostics Systems, Inc., Raritan, N.J.) (EIA) with iodine and fluorescent-antibody staining of inoculated McCoy cell monolayers for detection of Chlamydia trachomatis in our female outpatient populations. EIA was more sensitive than iodine at a statistically significant level, but there were no statistically significant differences between EIA results and those for fluorescent-antibody staining.
Differentiation of medically important isolates of Bipolaris and Exserohilum with exoantigens
Authors: Pasarell L , McGinnis M R , Standard P G
Published: January 2020

Soluble culture extracts of Bipolaris australiensis, B. hawaiiensis, B. spicifera, Exserohilum longirostratum, E. mcginnisii, E. rostratum, and Helminthosporium solani were used to prepare reference antisera in New Zealand White rabbits. The absorbed reference antisera were tested by a microimmunodiffusion method against concentrated culture filtrates prepared from 115 environmental and clinical isolates of Alternaria spp., Bipolaris spp., Curvularia spp., Dactylaria sp., Drechslera spp., Embellisia spp., Exserohilum spp., Fusarium sp., Helminthosporium sp., Microsporum sp., Scolecobasidium sp., and Scopulariopsis sp. Cross-reactivity did not occur between isolates of the genera tested except for some Bipolaris and Curvularia spp. Antigens shared by species of Bipolaris and Curvularia correlated with their morphologic similarity and phylogenetic closeness. Cross-reactivity was observed among isolates of B. australiensis, B. hawaiiensis, and B. spicifera and among isolates of E. longirostratum, E. mcginnisii, and E. rostratum. The exoantigen test is valuable for differentiating these fungi at the generic level.
Evaluation of the Directigen 1,2,3 Group A Strep Test for diagnosis of streptococcal pharyngitis
Authors: Moyer N P , Quinn P J , Showalter C A
Published: January 2020

The Directigen 1,2,3 Group A Strep Test (DGAST; BBL Microbiology Systems, Cockeysville, Md.) was compared with conventional culture methods for the detection of group A streptococci. Among 327 children, the DGAST has a sensitivity of 75.0%, a specificity of 99.1%, and positive and negative predictive values of 97.5 and 89.3%, respectively, as compared with 48-h culture results. The lower sensitivity (60.0%) in 322 adults was related to the low incidence of group A streptococcal pharyngitis in that population (7.8%). The positive and negative predictive values for adults were 93.8 and 96.7%, respectively. Only 3 of 327 (0.9%) pediatric and 2 of 322 (0.6%) adult specimens yielded uninterpretable results in the DGAST.
Candida norvegensis peritonitis and invasive disease in a patient on continuous ambulatory peritoneal dialysis
Authors: Nielsen H , Stenderup J , Bruun B , Ladefoged J
Published: January 2020

We report a case of Candida norvegensis invasive disease in an immunosuppressed renal transplant patient on continuous ambulatory peritoneal dialysis. Multiple cultures of peritoneal fluid, blood, and tracheal suction done over a 2-week period were positive for this unusual isolate. Despite treatment with amphotericin B and flucytosine the patient died. This is the first report of C. norvegensis fungemia documented by culture.
Enhancing effect of centrifugation on isolation of influenza virus from clinical specimens
Authors: Seno M , Kanamoto Y , Takao S , Takei N , Fukuda S , Umisa H
Published: January 2020

The use of centrifugation (700 x g, 60 min) in a plaque assay markedly increased (mean, 2.9-fold) the infectivity of all 42 influenza virus strains tested, compared with no centrifugation. Of 13 influenza virus strains isolated from 390 clinical specimens, 9 (69%) were efficiently isolated by the centrifugation assay compared with conventional culture methods. The centrifugation assay may be useful for isolating the influenza virus from clinical specimens.
The 83-kilodalton antigen of Borrelia burgdorferi which stimulates immunoglobulin M (IgM) and IgG responses in infected hosts is expressed by a chromosomal gene
Authors: Lefebvre R B , Perng G C , Johnson R C
Published: January 2020

We report the cloning and characterization of a chromosomal gene from Borrelia burgdorferi expressing an 83-kilodalton protein antigen in Escherichia coli. The antigen reacted strongly with antisera from two human Lyme disease patients. The chromosomal gene was expressed in a 6.5-kilobase-pair ClaI fragment cloned into a variable-reading-frame plasmid vector.
Identification of a high-virulence clone of serotype III Streptococcus agalactiae by growth characteristics at 40 degrees C
Authors: Mattingly S J , Maurer J J , Eskew E K , Cox F
Published: January 2020

A high-virulence clone of serotype III Streptococcus agalactiae causing invasive neonatal disease was previously identified by multilocus enzyme electrophoresis. A simple procedure involving growth at 40 degrees C distinguished all isolates classified in this high-virulence clone from other serotype III isolates, which are more frequently associated with asymptomatically colonized infants, as well as the other serotypes of group B streptococci. The high-virulence clone failed to grow at 40 degrees C in FMC, a chemically defined medium, in contrast to the other organisms, which grew readily.
Septicemia caused by vancomycin-resistant Pediococcus acidilactici
Authors: Golledge C L , Stingemore N , Aravena M , Joske D
Published: January 2020

A case of septicemia caused by vancomycin-resistant Pediococcus acidilactici is discussed. This appears to be the first reported case of septicemia caused by this organism. The characteristics and antimicrobial susceptibilities of this organism are described.
Antigenic variations in bovine viral diarrhea viruses detected by monoclonal antibodies
Authors: Xue W , Blecha F , Minocha H C
Published: January 2020

Five murine monoclonal antibodies (MAbs) against the NADL strain of bovine viral diarrhea (BVD) virus were developed, identified, and characterized. Four of the MAbs were directed against a 53-kilodalton (kDa) viral protein, and one was specific to a 47-kDa polypeptide. Competitive radioimmunoassay showed that two MAbs were specific to related epitopes of the 53-kDa protein, and the other three MAbs were each specific to a different epitope. The MAbs were used to study heterogeneity among BVD virus strains. Various degrees of reactivity of cytopathic and noncytopathic virus isolates were detected by virus neutralization and immunofluorescence assays. The virus isolates were divided into six groups based on the neutralization test. The results indicated that the 53-kDa glycoprotein of BVD virus is the major protein involved in virus neutralization and that only a few epitopes of the protein contribute to the neutralization. None of the MAbs neutralized all the BVD virus isolates tested in this study, suggesting antigenic variations among BVD virus isolates.
Identification of various serovar strains of Mycobacterium avium complex by using DNA probes specific for Mycobacterium avium and Mycobacterium intracellulare
Authors: Saito H , Tomioka H , Sato K , Tasaka H , Dawson D J
Published: January 2020

Reference strains of the Mycobacterium avium complex (MAC) belonging to serovars 1 to 28 were examined with DNA probes (Gen Probe Rapid Diagnostic System for the MAC; Gen Probe Inc., San Diego, Calif.) specific for either M. avium or Mycobacterium intracellulare. This study revealed that the earlier designations of the MAC serovars, in which serovars 1 to 3 and 4 to 28 were regarded as M. avium and M. intracellular, respectively, should be revised as follows. First M. avium includes serovars, 1 to 6, 8 to 11, and 21. Second, M. intracellulare includes serovars 7, 12 to 20, and 25. However, other serovars, such as serovars 22 to 24 and 26 to 28, involve M. intracellulare, Mycobacterium scrofulaceum, and MAC that are lacking in the reactivity with either DNA probe and that are too disordered to enable a conclusive description here, particularly concerning their taxonomic positions in the MAC.
Use of acute-stage-specific antigens of Toxoplasma gondii for serodiagnosis of acute toxoplasmosis
Authors: Suzuki Y , Thulliez P , Remington J S
Published: January 2020

Antisera to acetone-fixed tachyzoites were prepared by immunizing rabbits intravenously with the fixed organisms. Immunoblots in which purified immunoglobulin G (IgG) of the antisera was used recognized four antigens of a supernatant (after centrifugation at 10,000 x g for 30 min) fraction of sonicated tachyzoites. A purified toxoplasma antigen fraction, referred to as acute-stage-specific (AC) antigen, that contained mainly three antigens was obtained by affinity chromatography by using the purified IgG. One antigen had a molecular weight of approximately 52,000, and two antigens had molecular weights of approximately 6,000. An enzyme-linked immunosorbent assay (AC-ELISA) in which this purified antigen fraction, obtained by affinity chromatography, was used for detection of IgG antibody detected early acute infection in sera of patients with toxoplasmic lymphadenopathy. Ninety-two percent of sera obtained within 2 months after onset of lymphadenopathy were positive in the AC-ELISA, whereas only 9% of sera obtained later than 5 months after onset of the clinical illness were positive. The AC-ELISA appears highly sensitive and specific for diagnosis of acute toxoplasmosis.
Adenovirus types 40 and 41 and rotaviruses associated with diarrhea in children from Guatemala
Authors: Cruz J R , Cáceres P , Cano F , Flores J , Bartlett A , Torún B
Published: January 2020

From March 1987 to February 1988, fecal excretion of adenovirus types 40 and 41 and rotavirus serotypes in 194 children (age, 0 to 3 years) from a rural community of Guatemala was monitored. In total, 458 samples taken during 385 episodes of diarrhea and 191 specimens obtained during symptom-free periods were examined by enzyme-linked immunosorbent assay. Fifty-seven children hospitalized because of diarrhea were also studied. Among the rural children, 43 (22.2%) excreted adenovirus types 40 and 41 and 20 (10.3%) shed rotaviruses. Adenovirus types 40 and 41 were associated with 54 (14.0%) illnesses, and rotaviruses were associated with 18 (4.7%) illnesses. Asymptomatic infections with adenovirus types 40 and 41 were documented in nine children and with rotaviruses in two children. Fifteen typeable rotaviruses were identified as serotype 2. In the hospital population, 36 (63.2%) children had viral infections. Rotaviruses were identified in 29 (50.9%) and adenovirus types 40 and 41 were identified in 15 (31.2%) of 48 subjects tested. Dual infections by these viruses were found in eight children. Of 22 typeable strains of rotaviruses, 9 (34.6%) were serotype 1, 12 (46.1%) were serotype 2, and 1 (3.8%) was serotype 3. All the children infected with serotype 2 rotavirus were coinfected with other enteric pathogens, while only three (37.5%) of those infected with rotavirus serotype 1 excreted another pathogen. Adenovirus types 40 and 41 are an important cause of gastroenteritis in both ambulatory and hospitalized Guatemalan children. There seems to be a difference in the pathogenicity among rotavirus serotypes.
Indirect immunofluorescence test performance and questionnaire results from the Centers for Disease Control Model Performance Evaluation Program for human immunodeficiency virus type 1 testing
Authors: Taylor R N , Hearn T L , Schalla W O , Valdiserri R O
Published: January 2020

Results from laboratories performing indirect immunofluorescence (IIF) testing for human immunodeficiency virus type 1 antibody and participating in the Centers for Disease Control Model Performance Evaluation Program in 1988 are presented. Approximately 90% of all laboratories receiving specimen panels or questionnaires furnished results to the Centers for Disease Control. In September 1988, 111 reports were received from IIF laboratories from 34 states and nine countries; most of these laboratories did IIF testing in conjunction with other antibody tests. Hospital laboratories were the most common type of laboratory participating in the program. Laboratories that performed IIF employed fewer personnel and performed testing less frequently than did laboratories that performed enzyme immunoassays or Western blot (immunoblot) tests and were likely to use a commercial test kit. Most of the laboratories that referred specimens for IIF testing sent them to the state laboratory. The analytic specificity for the Model Performance Evaluation Program specimens was 98.5% when indeterminate results on a negative specimen were considered correct (negative) and 89.6% when indeterminate results on a negative specimen were considered incorrect; analytic sensitivity was 94.8% when indeterminate results on a positive specimen were correct (positive) and 91.4% when indeterminate results on a positive specimen were considered incorrect. When indeterminate results were considered correct, all types of laboratories (blood bank, state, hospital, independent, and other) had analytic specificities over 96%, and all manufacturers had analytic specificities above 95%. All types of laboratories had analytic sensitivities over 92%, and analytic sensitivities were above 94% for all manufacturers and reagent sources except Cellular Products. Comparison of percentages of correct responses between IIF and Western blot assays on those samples for which there was good agreement on the target interpretation revealed no significant differences. Both individual donor and diluted materials were included in the evaluations; the diluted donor material presented the greatest testing difficulty. Within-survey reproducibility was about 93% overall and by specimen type. Between-survey reproducibility was about 81% for negative and indeterminate specimens and 88.5% for positive specimens, for an overall between-survey reproducibility of 84.3%. Differences in performance were noted when results were compared by type of laboratory and test manufacturer.
Identification of toxigenic Clostridium difficile strains by using a toxin A gene-specific probe
Authors: Wren B W , Clayton C L , Castledine N B , Tabaqchali S
Published: January 2020

A 4.5-kilobase PstI fragment encoding part of the toxin A gene was isolated and used as a DNA probe in colony hybridization studies with 58 toxigenic and 17 nontoxigenic Clostridium difficile strains. All 58 toxigenic strains showed positive hybridization, in contrast to the 17 nontoxigenic strains. Southern blot analysis with the toxin A gene probe showed hybridization to a single fragment of equal intensities for HindIII-digested genomic DNAs isolated from C. difficile strains of wide-ranging toxin production. The positive hybridization signals were due to fragments of heterogeneous lengths (9 to 13 kilobases) for toxigenic strains of different types but were absent for the nontoxigenic strains. These results suggest the presence of a single copy of the toxin A gene on the genome of C. difficile strains, and the wide variation of toxin expression is not a reflection of gene copy number. The lack of toxin activity for nontoxigenic strains can be explained by the absence of at least part of the toxin A gene. The toxin A gene probe was tested against clostridial strains from 18 other species, of which only toxigenic C. sordellii strains showed positive hybridization. The specificity of the toxin A gene probe for toxigenic strains may lead to improved methods for the specific identification of toxigenic C. difficile strains from clinical specimens.
Influence of carbon dioxide on the surface characteristics and adherence potential of coagulase-negative staphylococci
Authors: Denyer S P , Davies M C , Evans J A , Finch R G , Smith D G , Wilcox M H , Williams P
Published: January 2020

Coagulase-negative staphylococci obtained from patients with continuous ambulatory peritoneal dialysis-related peritonitis were cultured in nutrient broth in an atmosphere of air containing 5% carbon dioxide (reflecting the CO2 tension found in freshly used dialysate). Significant differences were observed between the surface chemistries of cells grown in the two atmospheres, as determined by X-ray photoelectron spectroscopy and changes in the cell wall protein profile. The growth atmosphere also influenced the adherence potential toward polystyrene and silicone in a proportion of strains examined. Thus, gaseous conditions can profoundly influence the nature of the staphylococcal surface, and this should be considered in any in vitro study of in vivo behavior.
Monoclonal antibodies to 52-kilodalton protein of Salmonella typhi
Authors: Ekpo P , Sarasombath S , Banchuin N , Sirisinha S
Published: January 2020

Ten monoclonal antibodies (6 immunoglobulin G1 kappa [IgG1 kappa] and 4 IgG2b kappa) from six hybrid clones specific for Salmonella typhi antigen were produced by immunizing BALB/cJ mice with affinity-purified S. typhi proteins (Bp). The latter were prepared by passing crude S. typhi Bp through an affinity column made from Sepharose conjugated to IgG antibodies against partially purified S. typhi Bp. The eluent was subsequently used as the immunogen for the production of monoclonal antibody. All 10 monoclonal antibodies reacted specifically with a 52-kilodalton (kDa) protein of S. typhi and were species specific. The presence of IgM antibody to the 52-kDa antigen in the sera of a majority of patients with acute typhoid fever suggested that this 52-kDa protein is also a good immunogen for humans. The potential usefulness of this antigen in the early diagnosis of typhoid fever is discussed.
Evaluation of a murine model of hepatic candidiasis
Authors: Cole G T , Lynn K T , Seshan K R
Published: January 2020

A murine model of focal hepatic candidiasis which we suggest simulates certain conditions of this clinical variant of systemic candidiasis in leukemic patients is described. We have shown that outbred mice inoculated with Candida albicans by the oral-intragastric route as infants (6 days old) and then immunocompromised by cyclophosphamide and cortisone acetate treatment 2 weeks later demonstrate systemic spread of the opportunistic pathogen to the liver, lungs, spleen, and kidneys. Treatment with the immunosuppressive drugs cyclophosphamide and cortisone acetate resulted in alteration of the normal integrity of the mucosal epithelium of the gut as well as in granulocytopenia. Approximately 55% of the animals with C. albicans infections in the liver demonstrated hepatic abscesses. After these same infected, immunocompromised animals were treated with suboptimal dosages of antifungal agents (cilofungin or amphotericin B), either by intraperitoneal or subcutaneous (s.c.) routes, persistent hepatic abscesses were fewer in number and delimited by a distinct outer layer of host tissue but still contained large numbers of the viable pathogen. Blood cell counts indicated that these antifungal drug-treated animals had reestablished approximately the same number of leukocytes per microliter of blood as estimated prior to the immunocompromising drug treatment. Similar conditions in leukemic patients who were in remission and who were undergoing antifungal drug therapy for systemic candidiasis have been reported. Clearance of hepatic infections in mice was accomplished by using appropriate concentrations of amphotericin B administered by daily intraperitoneal or s.c. injection for 5 to 7 days or cilofungin by continuous s.c. infusion for 7 days. However, systemic antifungal therapy did not significantly reduce numbers of C. albicans cells in the stomach and esophagus. Persistent foci of gastrointestinal colonization by C. albicans, especially in the region of the cardial-atrium fold of the stomach of these mice, are reservoirs of the opportunistic pathogen from which reinfection may occur, leading to relapse of systemic candidiasis.
Comparison of the RIM-H rapid identification kit with conventional tests for the identification of Haemophilus spp
Authors: Palladino S , Leahy B J , Newall T L
Published: January 2020

A commercially available system, the RIM-H system (Austin Biological Laboratories, Austin, Tex.), was evaluated for its ability to rapidly and accurately identify various Haemophilus spp. A total of 110 clinical isolates were tested by both the RIM and conventional identification procedures. The RIM agreed with the standard identification for 100% of the Haemophilus influenzae (76 of 76) and 92.0% of the Haemophilus parainfluenzae (23 of 25) isolates tested. The identifications of Haemophilus parahaemolyticus, Haemophilus aphrophilus, and Haemophilus haemolyticus also correlated with those obtained by conventional methods. The RIM was found to be rapid and easy to use and was considered a suitable alternative to conventional identification procedures.
Identification of Mycoplasma felis and Mycoplasma gateae by an immunobinding assay
Authors: Brown M B , Gionet P , Senior D F
Published: January 2020

An immunobinding assay capable of distinguishing between Mycoplasma felis and Mycoplasma gateae was developed. Nitrocellulose was used as the solid support. Polyclonal rabbit antiserum against M. felis or M. gateae was used in the assay. Binding of the specific rabbit antiserum was detected by alkaline phosphatase-conjugated goat anti-rabbit immunoglobulin and an alkaline phosphatase substrate (Nitro Blue Tetrazolium-5-bromo-4-chloro-3-indolyl phosphate). The immunobinding assay was effective in the detection of feline mycoplasmas on agar plates, on primary isolation plates, in broth cultures, and in mixed cultures. No cross-reactions were observed with other related mycoplasmal species. The assay was cheap to perform and easy to interpret, and it required little technical time.
Evaluation of a modified complement fixation test and an indirect hemagglutination test for the serodiagnosis of melioidosis in pigs
Authors: Thomas A D , Spinks G A , D'Arcy T L , Hoffmann D
Published: January 2020

A complement fixation test modified by the addition of porcine serum and an indirect hemagglutination test were used to detect antibodies to Pseudomonas pseudomallei in pigs. These tests together with cultural examinations were carried out with 250 pigs. The sensitivity and specificity values were 79.3 and 99.5% and 82.8 and 93.2% for the modified complement fixation and hemagglutination tests, respectively. When results from the combination of both tests were considered, the values were 86.2 and 92.8%, respectively.
Rapid and sensitive detection of Mycobacterium leprae using a nested-primer gene amplification assay
Authors: Plikaytis B B , Gelber R H , Shinnick T M
Published: January 2020

By using a set of four nested oligonucleotide primers, a two-step polymerase chain reaction assay for the detection and identification of Mycobacterium leprae that does not require the use of radioactivity labeled hybridization probes was developed. The nested-primer procedure amplified a 347-base-pair product from M. leprae genomic DNA. No amplification products were produced from DNAs of 19 other Mycobacterium species, 19 non-Mycobacterium species, mouse cells, or human cells. Minor amplification products were observed with three additional Mycobacterium species, i.e., "M. lufu", M. simiae, and M. smegmatis. These products were easily distinguished from the M. leprae product by size and restriction enzyme cleavage patterns. The assay could amplify the 347-base-pair product from samples containing as little as 3 fg of M. leprae genomic DNA--the amount of DNA in a single bacillus. The assay also amplified target sequences in crude lysates of M. leprae bacilli isolated from tissue biopsy specimens from infected animals and humans. The entire assay, from sample preparation to data analysis, can be completed in less than 8 h.
Clinical comparison of isolator and BACTEC 660 resin media for blood culture
Authors: Kelly M T , Roberts F J , Henry D , Geere I , Smith J A
Published: January 2020

The 10-ml Isolator system (E.I. du Pont de Nemours & Co., Inc., Wilmington, Del.) was compared with the BACTEC 16A-17A nonradiometric resin system (Johnston Laboratories, Inc., Towson, Md.) for isolation of organisms from 6,839 paired blood cultures. Equal volumes of blood (6 to 10 ml for each Isolator and 3 to 5 ml for each BACTEC bottle) were cultured in parallel in the two systems, and 600 isolates that were judged to be clinically significant by chart review were recovered during the study. The BACTEC resin system detected 510 (85%) and the Isolator system detected 435 (72%) of the clinically significant isolates (P less than 0.001). Of 45 polymicrobial blood cultures, the BACTEC system detected 32 (71%) and the Isolator system detected 21 (47%) (P less than 0.05). Of 253 gram-negative bacilli isolated during the study, 30% were detected only in the BACTEC system and 16% were detected only in the Isolator system (P less than 0.001), and of 56 nonfermentative or fastidious gram-negative bacilli detected, 46% were recovered only in the BACTEC system, while 14% were detected only in the Isolator system (P less than 0.001). Of 86 streptococci isolated during the study, 30% were detected only in the BACTEC system, and 4% were detected only in the Isolator system (P less than 0.001). Recoveries of anaerobic bacteria, staphylococci, and yeasts were equivalent in the two systems. Organisms judged to be contaminants were detected in approximately 1% of the cultures in each system. The results suggest that use of resin media renders the BACTEC nonradiometric system equivalent or superior to the Isolator system for detection of clinically significant organisms in blood cultures.
Diagnosis of Chlamydia trachomatis cervical infection by detection of amplified DNA with an enzyme immunoassay
Authors: Bobo L , Coutlee F , Yolken R H , Quinn T , Viscidi R P
Published: January 2020

A sensitive and specific system for detection of amplified Chlamydia trachomatis DNA from cervical specimens by fluorometric quantitation in an enzyme immunoassay (EIA) format (polymerase chain reaction [PCR]-EIA) is described. The primers selected for PCR-amplified DNA were from the 15 serovars of C. trachomatis and two strains of Chlamydia pneumoniae (TWAR). One strain of Chlamydia psittaci (Borg) was not amplified. One hundred four previously cultured cervical specimens were evaluated. Forty-six culture-positive specimens containing from 1+ to 4+ inclusion bodies were all positive by PCR-EIA. Of 58 culture-negative specimens, 2 were repeatedly positive and were nonreactive with control probes. This assay system represents a sensitive and specific combination of technologies for the quantitative detection of C. trachomatis DNA directly from a body fluid.
Analysis of a repetitive DNA sequence from Bordetella pertussis and its application to the diagnosis of pertussis using the polymerase chain reaction
Authors: Glare E M , Paton J C , Premier R R , Lawrence A J , Nisbet I T
Published: January 2020

A tandemly repeated 1,046-base-pair (bp) ClaI DNA fragment from Bordetella pertussis was cloned into Escherichia coli by using the vector pUC19. This fragment, when isolated, hybridized strongly to DNA from all 100 clinical isolates of B. pertussis tested. It was shown to have homology to single-copy sequences in Bordetella bronchiseptica but not Bordetella parapertussis and did not hybridize to lysate blots of a wide range of other bacteria, including members of the closely related genera Pasteurella, Alcaligenes, and Haemophilus. The 1,046-bp fragment was sequenced, and complementary synthetic oligonucleotides flanking a 153-bp region within the repeated element were used as primers for specific amplification of this region using the polymerase chain reaction (PCR). This procedure was then applied to the rapid (5-h) detection of B. pertussis in nasopharyngeal secretions collected from 332 children with suspected pertussis. The test yielded positive results in a total of 98 samples, compared with 66 for culture and 33 for direct immunofluorescence (IF). All of the IF-positive samples were PCR positive, as were 63 of the samples from which B. pertussis was eventually cultured. Two hundred thirty-one specimens which were negative by IF and culture were also negative in the PCR assay. However, 33 culture- and IF-negative specimens were positive by PCR assay. Several of these specimens were collected from close contacts of culture-proven pertussis patients, were follow-up specimens from such patients, or were from patients with serological evidence of pertussis and therefore may be true-rather than false-positives.
Identification of Haemophilus aphrophilus and Actinobacillus actinomycetemcomitans by DNA-DNA hybridization and genetic transformation
Authors: Tønjum T , Bukholm G , Bøvre K
Published: January 2020

DNA-DNA hybridization was used to identify clinical isolates as Haemophilus aphrophilus or Actinobacillus actinomycetemcomitans. Some of the isolates were naturally competent for genetic transformation and were also used as DNA recipients for identification of other isolates. The results obtained by hybridization were supported by interstrain-to-intrastrain transformation ratios. Distinction between the closely related species H. aphrophilus and A. actinomycetemcomitans was generally clear-cut by both methods. Distinction of H. aphrophilus and A. actinomycetemcomitans from type and reference strains of a diversity of species in the family Neisseriaceae and other gram-negative species was also demonstrated by both methods. This is the first description of the identification of clinical isolates of H. aphrophilus or A. actinomycetemcomitans by using them as recipients in genetic transformation. The results suggest that this is a reliable system for identification of new clinical isolates belonging to these taxonomic entities.
Application of a rapid microplaque assay for determination of human immunodeficiency virus neutralizing antibody titers
Authors: Hanson C V , Crawford-Miksza L , Sheppard H W
Published: January 2020

To perform a human immunodeficiency virus (HIV) plaque assay in nonadherent host cells, we developed a novel technique in which HIV-infected MT-2 cells were formed into monolayers by centrifugation through molten agarose. Infection, formation of cell monolayers, and enumeration of plaques all took place in 96-well microtiter plates. When this process was preceded by 18 h of incubation of HIV with patient serum samples, neutralizing antibody titers between 1:10 and 1:5,000 could be accurately determined in patient serum samples. In addition to the determination of neutralizing antibody titers (with the use of various serum dilutions and a constant virus concentration), neutralization indices could also be determined with different virus dilutions and a single dilution of patient serum.