bluuebunny/crossref_metadata_2025 huggingface dataset:
Use of the RapID-ANA system and sodium polyanetholesulfonate disk susceptibility testing in identifying Haemophilus ducreyi
Authors: Shawar R , Sepulveda J , Clarridge J E
Published: January 2020

Haemophilus ducreyi has traditionally been difficult to identify. We have utilized simple test methods to identify 19 fresh isolates obtained during a recent outbreak of chancroid in Houston and six strains of H. ducreyi from other outbreaks. Tests were performed from growth on chocolate agar after 48 h of incubation at 35 degrees C with increased humidity and CO2. All isolates exhibited typical colonial morphology and Gram stain. Isolates were catalase negative and oxidase and nitrate positive (in enriched broth). The RapID NH system failed to identify these strains because of negative reactions with alkaline phosphatase and nitrate reductase. However, by using the RapID-ANA system, all strains were positive for alkaline phosphatase and arginine, glycine, and serine aminopeptidases. Their biochemical profiles were distinct from those obtained with 66 strains representing 13 species similar to H. ducreyi. We also investigated the use of sodium polyanetholesulfonate (SPS) disk susceptibility to identify and differentiate H. ducreyi from other species. All H. ducreyi isolates were susceptible, as evidenced by the presence of a zone of inhibition with an average size of 15 mm around the SPS disk. With the exceptions of Neisseria gonorrhoeae, Gardnerella vaginalis, and Capnocytophaga spp., no other strain showed any evidence of inhibition. The latter three organisms can be easily differentiated from H. ducreyi by various features including reactions in the RapID-ANA. We conclude that, by considering simple growth and biochemical characteristics, SPS susceptibilities, and reactions in RapID-ANA, it is possible for more clinical laboratories to definitively identify this organism.
Comparison of a latex agglutination assay and an enzyme-linked immunosorbent assay for detecting cholera toxin
Authors: Almeida R J , Hickman-Brenner F W , Sowers E G , Puhr N D , Farmer J J , Wachsmuth I K
Published: January 2020

To determine the pandemic potential of Vibrio cholerae, one must demonstrate both the presence of O1 antigen and the production of enterotoxin (CT). Tissue culture or enzyme-linked immunosorbent assays (ELISAs) for CT have been limited to research and reference laboratories. A kit for detecting CT by reversed passive latex agglutination is now commercially available and was used to test 168 strains of V. cholerae O1 and non-O1. When compared with the routine ELISA, the latex test was 98% accurate (86 of 88) for serogroup O1 strains and 100% accurate (80 of 80) for non-O1 strains. For both O1 and non-O1 study strains, the sensitivity of the latex agglutination test was 0.97 and the specificity was 1.00 when results were compared with ELISA results. The latex test is commercially available and has the advantages of being less complicated and less time-consuming than the ELISA.
Detection of verotoxin in stool specimens
Authors: Maniar A C , Williams T , Anand C M , Hammond G W
Published: January 2020

A total of 132 fecal specimens containing verotoxin (VT) were subjected to counter-current immunoelectrophoresis (CIE). Of these, 113 (85.6%) were found to be positive by CIE. Another 71 stool specimens containing E. coli serogroup O157 but with flagellar antigens other than H7 were tested for verotoxin by CIE. These stool specimens were negative for VT on Vero cell monolayers. Of these 71 stool specimens, 6 (8.5%) gave positive tests for verotoxin by CIE. Forty stool specimen filtrates which were negative for VT (negative controls) were also subjected to CIE. One of these stool specimen filtrates gave a line of precipitation by CIE. The specificity of the CIE test was 93.7%, and the sensitivity was 85.6%. False-positive results may have been due to an antibody component against the somatic antigen (O157) in the antitoxin used; this is a limitation of the CIE test. In a related evaluation, 302 stool specimen filtrates containing VT were retested with Vero cell suspension cultures in microdilution plates. Of these, 281 stool specimen filtrates showed cytotoxic effects within 24 h, while the remaining 21 filtrates showed the effects within 48 h. The use of Vero cell suspension culture is as reliable as the use of Vero cell monolayers and provides detection of verotoxin 24 to 48 h sooner.
Numerical analysis of electrophoretic periplasmic protein patterns, a possible marker system for epidemiologic studies
Authors: Gargallo-Viola D , López D
Published: January 2020

The whole-cell and periplasmic protein (PP) compositions of 22 Serratia marcescens isolates were examined. Numerical analysis of whole-cell protein patterns was not a useful procedure for measuring relationships between organisms at the subspecific level. However, there was a very good correlation between electrophoretic PP pattern results and those obtained previously from multilocus enzyme electrophoresis (electrophoretic type) and biotype (D. Gargallo-Viola, J. Clin. Microbiol. 27:860-868, 1989). Clustering of isolates by using PP patterns compared by coefficients based on peak position (Dice coefficient) gave more precise information than that obtained by correlation coefficients. PP patterns appeared to be a useful tool that may be of value for epidemiologic studies.
Bacteremias caused by Selenomonas artemidis and Selenomonas infelix
Authors: Bisiaux-Salauze B , Perez C , Sebald M , Petit J C
Published: January 2020

We report two different cases of bacteremia caused by two recently described Selenomonas species, Selenomonas artemidis and Selenomonas infelix. Both species are normally found in human buccal flora. S. artemidis bacteremia appeared in a patient (number 1) who presented with an air-fluid pulmonary cavity and clinical conditions consistent with an anaerobic lung abscess. While the patient improved with antibiotic therapy, cultures of respiratory secretions yielded Mycobacterium tuberculosis. This case demonstrated a strong possibility of a coexisting lung abscess due to S. artemidis. S. infelix bacteremia appeared in a cancer patient (number 2) with heart disease during preterminal acute respiratory distress. It was more difficult in this case to assess the clinical impact of the Selenomonas organisms on the patient.
Serodiagnosis of respiratory syncytial virus (RSV) infection in children as measured by detection of RSV-specific immunoglobulins G, M, and A with enzyme-linked immunosorbent assay
Authors: Meddens M J , Herbrink P , Lindeman J , van Dijk W C
Published: January 2020

The diagnostic value of an enzyme-linked immunosorbent assay for detection of respiratory syncytial virus (RSV)-specific immunoglobulin G (IgG), IgM, and IgA in sera from infants and children with proven RSV infection, from a control group, and from patients with symptoms of viral respiratory disease was analyzed. Compared to virus isolation and RSV antigen detection methods, the sensitivity of this assay was 87% and the specificity was 79%. For IgG alone, these were 45 and 92%, for IgM alone they were 48 and 92%, and for IgA alone they were 74 and 95%, respectively.
Inactivation of human immunodeficiency virus type 1 in tissue culture fluid and in genital secretions by the spermicide benzalkonium chloride
Authors: Wainberg M A , Spira B , Bleau G , Thomas R
Published: January 2020

We have shown that the spermicidal agent benzalkonium chloride can exert a direct inhibitory effect on the viral reverse transcriptase activity of human immunodeficiency virus type 1 (HIV-1) when utilized at concentrations of 0.05% and higher. Exposure of HIV-1 to this disinfectant at concentrations of more than 0.05% was able to completely destroy viral infectivity, as assessed on susceptible target cells. We have further shown that HIV-1, which is present in both seminal and genital secretions, can be inactivated in such fluids by direct exposure to benzalkonium chloride.
Adherence of skin bacteria to human epithelial cells
Authors: Romero-Steiner S , Witek T , Balish E
Published: January 2020

Aerobic and anaerobic bacteria isolated from human axillae were tested for their capacity to adhere to buccal epithelial cells, immortalized human epithelial (HEp-2) cells, and undifferentiated and differentiated human epithelial cells. In general, both aerobic and anaerobic diphtheroids adhered better to differentiated human epithelial cells than to HEp-2 and undifferentiated human epithelial cells (P less than 0.05). Mannose, galactose, fucose, N-acetyl-D-glucosamine, and fibronectin were also assayed for their capacity to inhibit the adherence of diphtheroids to human epithelial cells. A great deal of variability was observed in the capacity of the latter compounds to inhibit the attachment of aerobic diphtheroids to undifferentiated and differentiated epithelial cells. Overall, mannose appeared to be best at inhibiting the adherence of the aerobic diphtheroids to undifferentiated human epithelial cells. Galactose, fucose, N-acetyl-D-glucosamine, and fibronectin showed a greater capacity to inhibit attachment of aerobic diphtheroids to differentiated than to undifferentiated human epithelial cells. The inhibition of adherence to differentiated human epithelial cells varied with the microorganism and the compound tested; however, the highest and most consistent inhibition of adherence (76.1 to 88.6%) was observed with a 5% solution of N-acetyl-D-glucosamine. The in vitro adherence and adherence inhibition assays presented here demonstrate that a number of adhesins and receptors are involved in the adherence of skin bacteria to human epithelial cells and receptors on human epithelial cells are apparently altered during differentiation.
Evaluation of the commercially available HepProbe kit for detection of hepatitis B virus DNA in serum
Authors: Valentine-Thon E , Steinmann J , Arnold W
Published: January 2020

The commercially available HepProbe kit involving the use of a 32P-labeled RNA probe was evaluated for its sensitivity, specificity, and reproducibility in detecting hepatitis B virus (HBV) DNA in patient serum by dot blot hybridization. The level of detection was 0.3 pg, corresponding to 3 x 10(4) genomes in 50 microliters of serum. A total of 181 serum samples were tested; 53 (82%) of 65 patients positive for both hepatitis B surface antigen and hepatitis e antigen were positive for HBV DNA compared with only 12 of 74 (16%) hepatitis B surface antigen-positive but hepatitis e antigen-negative individuals. In addition, among all patients positive for HBV DNA, there was a statistically significant correlation between the concentration of HBV DNA in serum and the presence or absence of hepatitis e antigen. None of the 42 hepatitis B surface antigen- and hepatitis e antigen-negative patients tested was positive for HBV DNA. Reproducibility was 87%, with all discordant results representing borderline positives. The results indicate that HepProbe can be employed as a sensitive and reliable assay for HBV DNA in patient serum.
Several membrane polypeptides of the live vaccine strain Francisella tularensis LVS stimulate T cells from naturally infected individuals
Authors: Sjöstedt A , Sandström G , Tärnvik A
Published: January 2020

The currently used live vaccine strain Francisella tularensis LVS was derived several decades ago from a wild strain of the species. In the present report, several membrane polypeptides of LVS are shown to be recognized by T cells from individuals immunized by natural infection with F. tularensis. Bacterial membranes of a capsule-deficient mutant of LVS were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Thereafter, gels were divided into seven fractions, each fraction containing a different number of peptide bands. From other gels, four bands were excised, each containing one major polypeptide. Eluates of each fraction and of each polypeptide band induced a proliferative response and an interleukin-2 response in lymphocytes from most of the individuals. When the lymphocytes were separated after induction, most of the proliferative response was found to occur in CD4+ T cells. Lymphocytes from nonimmune individuals responded poorly to all membrane polypeptides. To study the possible heterogeneity of antigen determinants among the polypeptides, T-cell clones were raised towards F. tularensis and tested for proliferative response to the four major membrane polypeptides. Five clones, all CD4+ CD8-, responded to one or more of the polypeptides, each clone with a unique pattern of response. In conclusion, F. tularensis possesses a high number of T-cell-reactive membrane polypeptides. There seems to be a heterogeneity of T-cell determinants among these polypeptides. Determinants involved in immunization by natural infection are well conserved in LVS.
Evaluation of an enzyme-linked immunosorbent assay that uses ferrous metal beads for determination of antihistoplasmal immunoglobulins G and M
Authors: Zimmerman S E , French M L , Kleiman M B , Wheat L J
Published: January 2020

A rapid enzyme-linked immunosorbent assay (ELISA) for the detection of human class-specific antibodies to Histoplasma capsulatum (histoplasmal immunoglobulin M [HIgM] and histoplasmal IgG [HIgG]) was developed by using antigen adsorbed onto polycarbonate-coated ferrous beads. In the ELISA method all the reagents used were commercially available. In 135 specimens from patients with confirmed histoplasmosis, sensitivities were 76% for complement fixation (CF), 53% for immunodiffusion (ID), and 64% for the ELISA for HIgM and HIgG combined. The ELISA detected histoplasmal antibody in 36% of the specimens with negative antibody titers by CF and 46% of the specimens with negative antibody titers by ID. The ELISA detected histoplasmal antibody in 27% of specimens that were negative by both CF and ID. When limited to specimens collected within 4 months of the onset of histoplasmosis symptoms, sensitivities were 82% for CF, 63% for ID, and 86% for ELISA for HIgG and HIgM combined. Within this group, ELISA detected histoplasmal antibody in 90% of the specimens that were negative by CF, 76% that were negative by ID, and 100% that were negative by both CF and ID. The specificity of the ELISA could not be fully addressed since sera from patients with other fungal infections were not available.
Three-year experience with sonicated vascular catheter cultures in a clinical microbiology laboratory
Authors: Sherertz R J , Raad I I , Belani A , Koo L C , Rand K H , Pickett D L , Straub S A , Fauerbach L L
Published: January 2020

Using a quantitative sonication method, we cultured 1,681 consecutive vascular catheters submitted to a clinical microbiology laboratory in a 36-month period. A total of 46% of the cultures were positive; the most common organisms isolated were coagulase-negative staphylococci (36.4%), Pseudomonas aeruginosa (13.9%), enterococci (10.0%), yeasts (9.2%), Staphylococcus aureus (5.8%), and Enterobacter species (4.4%). The frequencies of positive blood cultures within 48 h prior to a positive catheter culture result were as follows: Candida albicans (68.4%), S. aureus (60%), Enterobacter cloacae (42.9%), Staphylococcus epidermidis (32.1%), P. aeruginosa (27.7%), and enterococci (23.3%). The sonication method allowed quantification of the number of CFU removed from a catheter for between 10(2) and 10(7) CFU. For catheter cultures in which greater than or equal to 10(2) CFU grew, a linear regression equation could be calculated: (risk of positive blood culture for the same organism) = 14 [log10 (number of organisms removed from the catheter)] -21 (r = 0.93). For catheter cultures in which less than 10(2) CFU grew, positive blood cultures for the same organism were strongly associated with a proven infection at a site distant from the catheter (P = 0.001) or probable contamination (S. epidermidis). Our findings indicate that this technique has considerable potential for use in clinical microbiology laboratories to aid in the diagnosis of vascular catheter infections and for clinical investigations into the pathogenesis of these infections.
Typing of Campylobacter pylori by bacterial DNA restriction endonuclease analysis and determination of plasmid profile
Authors: Simor A E , Shames B , Drumm B , Sherman P , Low D E , Penner J L
Published: January 2020

Campylobacter pylori isolates from 37 symptomatic patients and 3 asymptomatic volunteers were examined by chromosomal DNA restriction endonuclease analysis and determination of plasmid profile. Restriction digests with HindIII, HaeIII, PvuII, and BglII produced clear and reproducible results that permitted discrimination between different strains. Only 35% of C. pylori isolates were found to have plasmid DNA. Isolates from different patients, including those from two pairs of siblings, had unique restriction patterns and plasmid profiles. Consecutive isolates obtained 1 year apart from each of two asymptomatic volunteers had identical restriction patterns and plasmid profiles, suggesting persistence of the same strain. A pair of isolates obtained one year apart from the third volunteer differed in plasmid DNA content but had similar chromosomal DNA restriction patterns. Plasmid profile determination and bacterial DNA restriction endonuclease analysis provide a reliable means of discriminating between different strains of C. pylori and may be useful for typing these organisms in epidemiologic studies.
Recombinant fusion protein for simple detection of Escherichia coli heat-stable enterotoxin by GM1 enzyme-linked immunosorbent assay
Authors: Sanchez J , Holmgren J , Svennerholm A M
Published: January 2020

A recombinant gene fusion protein composed of an Escherichia coli heat-stable enterotoxin (STa) peptide epitope fused to the amino end of the cholera toxin B subunit was used to detect STa produced by clinical isolates of enterotoxigenic E. coli (STa-ETEC) by a single monoclonal antibody-based inhibition GM1 enzyme-linked immunosorbent assay. In this test, 100% sensitivity and 100% specificity were observed for use of the recombinant protein in either its purified form or as crude Vibrio cholerae culture supernatants in detection of STa-ETEC.
Detection of restriction fragment length polymorphisms in clinical isolates and serially passaged Pseudomonas aeruginosa strains
Authors: Hjelm L N , Branstrom A A , Warren R L
Published: January 2020

An 800-base-pair HindIII-PstI fragment that flanks a hot spot for Tn7 insertion was isolated from the chromosome of Pseudomonas aeruginosa and cloned into pUC12. The fragment was used to probe XhoI digests of genomic DNA from 18 P. aeruginosa isolates collected from sputum samples of seven cystic fibrosis patients. Only two XhoI restriction fragment length polymorphisms (RFLPs), of 3.7 and 7.7 kilobases (kb), were detected. Isolate WSU3531-1 (3.7-kb XhoI fragment) and WSU3860 (7.7-kb XhoI fragment), while isolated from the same patient, showed different RFLPs. Serial passages of isolate WSU3531-1 demonstrated that this strain was phenotypically stable. In contrast, colony and pigment variants were readily isolated at a frequency of 1% from serial passages of isolate WSU3860. When XhoI-digested genomic DNA from phenotypic variants of serially passaged WSU3860 were probed with the 800-base-pair HindIII-PstI fragment, the probe hybridized to a 10.4-kb XhoI fragment from three isolates. Restriction analysis of the genomic DNA digested with a variety of restriction enzymes showed that a 2.7-kb insertion occurred in the same region for all three isolates. There appeared to be no correlation between changes in the RFLP and changes in colony morphology.
Influence of carbon dioxide on growth and antibiotic susceptibility of coagulase-negative staphylococci cultured in human peritoneal dialysate
Authors: Wilcox M H , Smith D G , Evans J A , Denyer S P , Finch R G , Williams P
Published: January 2020

Used peritoneal dialysis fluid was collected from patients undergoing continuous ambulatory peritoneal dialysis, and its pH and composition were assessed after incubation in either air or air with 5% CO2. Precipitation of calcium, magnesium, phosphate, and proteins occurred in the dialysis fluid incubated in air at 37 degrees C and was associated with a mean pH increase of 1.23 U. Incubation of dialysis fluid in air with 5% CO2 prevented precipitation and maintained pCO2 and pH levels at those found physiologically. Coagulase-negative staphylococcal strains isolated from patients with peritonitis tended to grow less well in dialysis fluid incubated in air than in dialysis fluid incubated in the carbon dioxide-enriched atmosphere. MICs of cefuroxime, ciprofloxacin, and vancomycin for seven strains of coagulase-negative staphylococci in dialysis fluid were markedly affected by atmosphere type (16 of 21 MICs). Of these 16 atmosphere-dependent MICs, 14 were at least fourfold higher in air than in air with 5% CO2.
Monoclonal antibody recognizing a species-specific protein from Streptococcus pneumoniae
Authors: Russell H , Tharpe J A , Wells D E , White E H , Johnson J E
Published: January 2020

Monoclonal antibodies (MAbs) against a nonencapsulated strain (R36A) of Streptococcus pneumoniae were produced to aid in a search for antigens common to this species. By Western immunoblot analysis, a species-specific 37-kilodalton (kDa) protein was found in lysates of 24 different encapsulated strains of S. pneumoniae. Monoclonal antibodies against the 37-kDa antigen did not react with 55 heterologous strains representing 19 genera and 36 species of bacteria that can also cause acute lower respiratory tract disease. Immunogold staining suggests that the antigen is synthesized inside the pneumococcal cell. However, MAbs to the 37-kDa antigen bound whole cells in the enzyme-linked immunosorbent assay and the indirect immunofluorescence assay. Antibody-binding epitopes of the antigen are probably exposed on the outer surface of the pneumococcus cell wall. The effectiveness of the 37-kDa antigen as a useful diagnostic marker is under study.
Characterization, in vitro susceptibility, and clinical significance of CDC group HB-5 from Rwanda
Authors: Bogaerts J , Verhaegen J , Martinez Tello W , Allen S , Verbist L , Van Dyck E , Piot P
Published: January 2020

From June 1984 until July 1988, CDC group HB-5 isolates were recovered from the exudates of genital ulcers in 25 of 675 (3.6%) patients (204 women, 471 men) in Kigali, Rwanda. Among a group of 145 men presenting with urethritis but without genital ulcers, a positive culture for HB-5 of a specimen from the coronal groove of the penis of only 1 man (0.7%) was found. During the same period, the organism was not obtained in cultures of vaginal specimens from 838 women without genital ulcer disease. The main biochemical characteristics of the isolated microorganisms included weak oxidase positivity, catalase negativity, indole positivity, reduction of nitrate to nitrite, acid production from D-glucose and fructose, and H2S production. A total of 75% of the organisms were susceptible to penicillin G. beta-Lactamase production was detected by the chromogenic cephalosporin test in a quarter of the strains. This study confirms that HB-5 can be found in the genital tract. HB-5 was associated with genital ulcer disease in Rwanda. However, its etiologic role in patients with this condition remains unclear.
Characterization of flagella of Clostridium difficile and their role in serogrouping reactions
Authors: Delmée M , Avesani V , Delferriere N , Burtonboy G
Published: January 2020

Slide agglutination with rabbit antisera allows the differentiation of 10 serogroups of Clostridium difficile, namely, A, B, C, D, F, G, H, I, K, and X. Each serogroup displays a specific protein profile in sodium dodecyl sulfate-polyacrylamide gel electrophoresis, except for A, which displays 12 different protein profiles (A1 to A12). In the present work, electron microscopy revealed the presence of uniformly distributed flagella in the reference strains of serogroups G and K and in all strains representative of the 12 subgroups within serogroup purified by differential centrifugation. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of these preparations revealed one distinct band with an apparent molecular mass of approximately 39 kilodaltons. Antiserum was prepared by immunizing a rabbit with the serogroup A flagellin, which had been eluted from the gel. In immunoblotting, this antiserum cross-reacted with the flagellin of the other strains. When the cells were deflagellated by a short sonication, the cross-reactions observed by slide agglutination with A, G, and K antisera were suppressed. Similarly, shearing of flagella allowed specific slide agglutination of the 12 subgroups of serogroup A.
Beta 2-microglobulin and neopterin: predictive markers for human immunodeficiency virus type 1 infection in children?
Authors: Chan M M , Campos J M , Josephs S , Rifai N
Published: January 2020

The value of beta 2-microglobulin and neopterin concentrations in serum for early diagnosis of infants born to human immunodeficiency virus type 1 (HIV-1)-infected mothers was assessed. Concentrations of both markers were measured in serum samples from pediatric patients (Centers for Disease Control classifications P0, P1, and P2), as well as in age-matched normal subjects. Both beta 2-microglobulin and neopterin were significantly increased in HIV-1-infected symptomatic subjects (P2) compared to controls. Seventy-five percent of asymptomatic patients (P1) also had increased values. On the other hand, a significant overlap in concentrations of both markers in serum was found between controls and P0 patients. Thirty-eight percent of the P0 patients had values comparable to those of the P2 group. Persistently high concentrations of both markers in P0 patients may be indicative of HIV-1 infection.
Evaluation of two monkey species (Macaca mulatta and Macaca fascicularis) as possible models for human Helicobacter pylori disease
Authors: Euler A R , Zurenko G E , Moe J B , Ulrich R G , Yagi Y
Published: January 2020

Endoscopic, histologic, and microbiologic evaluations of 21 cynomolgus and 34 rhesus monkeys for naturally occurring Helicobacter pylori infection were done. H. pylori was never isolated from any cynomolgus monkey, but was found in 12 rhesus monkeys. A general correlation existed between a positive culture and a gastric inflammatory response. Inoculation challenges were then undertaken. Four cynomolgus and five rhesus monkeys received two different H. pylori strains isolated from humans. Five rhesus monkeys received an isolate obtained from rhesus monkeys. Evaluation of the cynomolgus monkeys 7 and 14 days later revealed no H. pylori. Endoscopies of the rhesus monkeys were done 7, 14, 21, 28, and 56 days later. One rhesus monkey, which received the isolate from humans, became H. pylori positive at day 21 and remained positive through day 56. Restriction enzyme analysis of genomic DNA at day 56 revealed that the isolate was not identical to the challenge strain isolated from humans. All five rhesus monkeys that received the strain isolated from rhesus monkeys became H. pylori positive by day 14 and remained positive through day 56 Antral inflammation developed in all monkeys. Restriction enzyme analysis of genomic DNA on day 56 confirmed that four of five isolates were identical to the challenge strain isolated from rhesus monkeys. DNA hybridization documented homology between the challenge strains isolated from humans and rhesus monkeys plus those isolated at day 56. In this study, we showed that the rhesus monkey, if given a strain of H. pylori isolated from rhesus monkeys, develops a gastric infection with accompanying histological changes, making this model suitable for further development.
Nonvalue of antigen detection immunoassays for diagnosis of candidemia
Authors: Phillips P , Dowd A , Jewesson P , Radigan G , Tweeddale M G , Clarke A , Geere I , Kelly M
Published: January 2020

We evaluated the Cand-Tec (Ramco Laboratories Inc., Houston, Tex.) and LA-Candida antigen detection system (Immuno-Mycologics Inc., Norman, Okla.) tests as possible rapid alternatives to blood cultures for the identification of patients with candidemia. Tests were performed on sera from (i) 33 patients with candidemia, (ii) 82 patients with fever and risk factors for invasive candidiasis, and (iii) 13 healthy controls. A total of 21 patients had no evidence of invasive candidiasis, as determined by clinical course, blood culture, and/or autopsy; results for 61 patients were indeterminate regarding the presence of invasive candidiasis, or else the patients had invasive candidiasis with organ involvement. By using a threshold positive Cand-Tec titer of greater than or equal to 1:4, the sensitivity in candidemic patients was 49%; the specificity was 43% (patients with true-negative results had neither candidemia nor other evidence of invasive candidiasis). Coexistent disseminated candidiasis in some candidemic patients may have accounted for some positive Cand-Tec tests and possible overestimation of the sensitivity of the test for candidemia. Cand-Tec test results were negative for healthy controls. All test results obtained by the LA-Candida antigen detection system assay were negative. Our findings indicate that neither of these assays reliably identifies patients with candidemia.
Acyclovir treatment for varicella does not lower gpI and IE-62 (p170) antibody responses to varicella-zoster virus in normal children
Authors: Englund J A , Arvin A M , Balfour H H
Published: January 2020

The varicella-zoster virus (VZV) membrane glycoprotein gpI elicits a major immunoglobulin G antibody response after naturally acquired VZV infection; antibody to a nonglycosylated immediate-early protein, IE-62 (p170), represents a response to a nonmembrane VZV component. We evaluated antibody response to VZV gpI and IE-62 (p170) at 28 days and 1 year following infection in 34 children (ages 5 to 16 years) enrolled in a randomized placebo-controlled study of oral acyclovir for the treatment of varicella. All children were VZV antibody negative at enrollment, were previously healthy, and had laboratory-documented varicella. Compared with placebo recipients, acyclovir recipients had lower geometric mean titers by the fluorescent antibody to membrane antigen technique at 28 days (620 versus 836) but similar titers at 1 year (122 versus 122). All children had antibodies to gpI and IE-62 detectable by enzyme-linked immunosorbent assay at 28 days and 1 year. No difference in gpI at 28 days compared with 1 year was noted in acyclovir recipients. No difference in antibody to IE-62 (p170) was noted when acyclovir and placebo recipients were compared at either 28 days or 1 year. Antibody responses to gpI and IE were similar when children were stratified by age (5 to 6 years, 7 to 11 years, 12 to 16 years). A short course of oral acyclovir for the treatment of varicella did not affect antibody responses to gpI or IE-62 (p170) in healthy children at 28 days and 1 year following varicella.
Butyrate esterase (4-methylumbelliferyl butyrate) spot test, a simple method for immediate identification of Moraxella (Branhamella) catarrhalis [corrected]
Authors: Pérez J L , Pulido A , Pantozzi F , Martin R
Published: January 2020

A total of 47 Moraxella (Branhamella) catarrhalis strains, 89 strains of Neisseria spp., and 82 strains of miscellaneous bacteria and yeasts were studied by using a fluorogenic spot method which detects butyrate esterase. A positive butyrate esterase spot test correctly differentiated M. catarrhalis from Neisseria spp., which had a negative butyrate esterase spot test reaction. The test is rapid, simple, and easy to perform. The butyrate esterase spot test was useful for direct identification of M. catarrhalis from primary cultures. However, false-positive reactions may occur with mixed cultures.
Microbiological characteristics of Weeksella virosa (formerly CDC group IIf) isolated from the human genitourinary tract
Authors: Reina J , Gil J , Salva F , Gomez J , Alomar P
Published: January 2020

Weeksella virosa (formerly CDC group IIf) is a nonsaccharolytic, oxidase- and catalase-positive, gram-negative rod which is unable to grow on MacConkey agar. At 48 h of incubation on blood or chocolate agar, the colonies present a characteristic appearance: intensely mucoid, adherent, and cream colored as a result of the production of a nondiffusible yellow pigment. This microorganism has been isolated predominantly from the female genitourinary tract, which indicates the opportunity for sexual transmission. We present the microbiological study of three strains of W. virosa identified in a study of 707 female genital samples, representing an incidence of 0.42%. At the same time, we analyzed the principal biochemical tests used in the identification of this microorganism and the susceptibilities of the organism to the different antimicrobial agents assayed.
Detection of Epstein-Barr virus DNA sequences in nasopharyngeal carcinoma cells by enzymatic DNA amplification
Authors: Chang Y S , Tyan Y S , Liu S T , Tsai M S , Pao C C
Published: January 2020

The presence of Epstein-Barr virus (EBV) DNA sequences was examined by the polymerase chain reaction in 50 nasopharyngeal carcinoma (NPC) biopsy specimens and in two primary epithelial tumor cell cultures derived from patients with NPC. The detection limit was a single EBV genome equivalent by agarose gel electrophoresis followed by Southern blot analysis of the amplified products. EBV DNA sequences were detected in all 41 undifferentiated NPC cell specimens, in 2 of 4 moderately differentiated NPC cell specimens, and in 3 of 5 keratinized NPC cell specimens. Undifferentiated NPC cells were also found to contain higher copy numbers of EBV than cells of the other two types of NPC. Our data suggest that EBV replication may be closely associated with the differentiation of NPC tumor cells. The results also demonstrated a sensitive and specific method for the detection of EBV DNA sequences in NPC tumor cells.
Detection of a novel fimbrial structure on the surface of Salmonella enteritidis by using a monoclonal antibody
Authors: Thorns C J , Sojka M G , Chasey D
Published: January 2020

A fimbrialike structure expressed on the surface of Salmonella enteritidis was identified by using a monoclonal antibody (69/25) produced against intact S. enteritidis cells. Fimbriae were less than 5 nm in diameter and carried a protein consisting of subunits with a molecular weight of 14,300. No hemagglutinating activity associated with the fimbriae was detected. An epitope on the fimbrial antigen identified by monoclonal antibody 69/25 was expressed by all 58 S. enteritidis strains, 12 of 36 S. dublin strains, and a single strain of S. moscow examined. None of 169 other isolates tested from 17 salmonella serogroups expressed this epitope.
Mice and moles inhabiting mountainous areas of Shimane Peninsula as sources of infection with Yersinia pseudotuberculosis
Authors: Fukushima H , Gomyoda M , Kaneko S
Published: January 2020

A total of 1,835 Yersinia spp. were isolated from 925 (60.5%) of 1,530 wild mice and from 139 (79.9%) of 174 moles living in mountainous areas of eastern Shimane Prefecture, Japan. The Yersinia spp. included 1,106 Yersinia enterocolitica, 26 Y. enterocolitica-like, 176 Yersinia mollaretii, 149 Yersinia frederiksenii, 70 Yersinia intermedia, 231 Yersinia kristensenii, 5 Yersinia aldovae, and 72 Yersinia pseudotuberculosis. Human pathogenic Y. enterocolitica was not isolated. Y. pseudotuberculosis was divided into 10 virulent 40- to 50-MDa plasmid-positive (P+) strains (serotypes 1b, 4b, and untypeable) and 62 plasmid-negative (P-) strains (serotypes 1b, 2b, 2c, 4a, 5a, 5b, 6, 7, and untypeable). P+ strains of serotypes 1b (two strains), 4b (seven strains), and untypeable (one strain) were isolated from nine Apodemus specious and one Apodemus argenteus. The isolates of Yersinia spp. were more frequently detected in newborn mice and during the breeding season. The P+ Y. pseudotuberculosis strains were recovered at less than 10(4) cells per g of the cecal contents. Thus, the prevalence of Yersinia spp. in small wild animals depends on the newborn animals born during the cold months, and wild mice in mountainous areas are important reservoirs of Y. pseudotuberculosis.
Isolation of 16 strains of Coxiella burnetii from patients by using a sensitive centrifugation cell culture system and establishment of the strains in HEL cells
Authors: Raoult D , Vestris G , Enea M
Published: January 2020

Q fever, caused by Coxiella burnetii, may be acute or chronic. Only a few strains of C. burnetii have been isolated due to the difficulty and hazard of isolation. We report here the isolation using a centrifugation shell vial technique of 16 new strains from patients suffering chronic Q fever. Twenty-four samples were inoculated onto human embryonic lung (HEL) fibroblast cell monolayers growing in shell vials. C. burnetii was detected 6 days later by using immunofluorescence. Samples from valves (n = 10), arterial prostheses (n = 2), bone (n = 3), skin biopsy (n = 1), bone marrow (n = 1), and blood (n = 5) from 16 patients were successfully cultured. Two cerebrospinal fluid samples from two patients were negative. The strains were subcultured in HEL cells and are now established. The technique is sensitive and less hazardous than animal inoculation. We recommend the shell vial technique for isolation of C. burnetii.
Importance of salmonellae and Campylobacter jejuni in the etiology of diarrheal disease among children less than 5 years of age in a community in Bangkok, Thailand
Authors: Varavithya W , Vathanophas K , Bodhidatta L , Punyaratabandhu P , Sangchai R , Athipanyakom S , Wasi C , Echeverria P
Published: January 2020

The etiology of diarrhea in children less than 5 years of age in a low-income housing project in Bangkok, Thailand, was determined over 1 year. Nontyphoidal salmonellae (13%), Campylobacter jejuni (12%), rotavirus (12%), enterotoxigenic Escherichia coli (7%), shigellae (6%), E. coli that hybridized with the enteropathogenic E. coli adherence factor probe (3%), and enteroinvasive E. coli (1%) were identified in 345 episodes of diarrhea in children less than 5 years of age. Salmonellae were identified in 17% and C. jejuni was identified in 15% of 54 children less than 6 months of age with diarrhea. Shigellae, enteroinvasive E. coli, enteropathogenic E. coli adherence factor, and enterotoxigenic E. coli were not isolated from children less than 6 months of age. Since salmonellae and C. jejuni were the most common bacterial pathogens identified in children less than 6 months of age, efforts to prevent transmission of salmonellae and campylobacter to young children should be a public health priority in Bangkok.
Comparative evaluation of two test methods (enzyme immunoassay and latex fixation) for the detection of heterophil antibodies in infectious mononucleosis
Authors: Kim M , Wadke M
Published: January 2020

The present study evaluated the Ventrescreen Mono enzyme immunoassay (Ventrex Laboratories) and Monolatex (Wampole Laboratories) for detection of infectious mononucleosis-specific heterophil antibodies by comparing test results on sera of 247 symptomatic patients. The purpose of this study was to compare not only the two different test systems but also the two different methods they represent for accuracy in detecting infectious mononucleosis-specific heterophil antibodies. Discrepancies in the test results of the two kits were arbitrated by determining the Epstein-Barr virus antibody profiles of the samples. The study showed that the Ventrescreen Mono enzyme immunoassay is as good as the Monolatex test for detecting heterophil antibodies. After discrepancies were resolved, the sensitivity and specificity of the Ventrescreen assay were 100 and 98%, respectively.
Quantitation of antibody reactivity to human immunodeficiency virus (type 1) proteins and glycoproteins on Western immunoblots by reflectance densitometry
Authors: Hardy C T , Damrow T A , Kenny G E
Published: January 2020

The human serum antibody response to polypeptides of human immunodeficiency virus type 1 (HIV-1) was quantitated by reflectance densitometry of Western immunoblots by using two commercially available blotting systems. In one system, human antibodies were detected by an avidin-biotin method using peroxidase as the label, and in the other, human antibodies were detected by peroxidase-labeled conjugate against human immunoglobulins. When staining intensity was plotted against the log of the serum dilution, a shallow slope was evident, with a 50% change in staining intensity requiring as much as a 100-fold change in antibody content. The linear range of the staining intensity curves was frequently found in serum dilutions of 1:2,500 to 1:1,000,000, and a plateau was often observed at high antibody concentrations (1:80 to 1:640). When replicate strips were tested, staining intensities varied by +/- 7 to 37%. Antibodies to p24gag and gp160env were readily detectable in several sera diluted 1:1,000,000, a result seen with both blotting systems. If Western blotting were to be used to observe increase or decreases in levels of antibodies to various polypeptides, several widely spaced serum dilutions would need to be tested.
Interpretation of gram-stained sputa containing Moraxella (Branhamella) catarrhalis
Authors: Ainsworth S M , Nagy S B , Morgan L A , Miller G R , Perry J L
Published: January 2020

Sputum specimens culture positive for Moraxella (Branhamella) catarrhalis were Gram stained with three decolorizer solutions (slow, 95% ethyl alcohol; intermediate, 1:1 ratio of 95% ethyl alcohol and acetone; and fast, acetone alone) for 5, 10, 20, and 30 s. Optimal results were obtained with acetone alone after 10 s or with a 1:1 mixture of acetone and ethanol after 20 s. Inadequate decolorization of M. catarrhalis in sputa is likely if the decolorization solution and exposure time are not optimal and may contribute to underreporting of this organism.
Comparison of Guizotia abyssinica seed extract (birdseed) agar with conventional media for selective identification of Cryptococcus neoformans in patients with acquired immunodeficiency syndrome
Authors: Denning D W , Stevens D A , Hamilton J R
Published: January 2020

Growth of Cryptococcus neoformans from the sputum of patients with acquired immunodeficiency syndrome may be obscured by oral contamination with Candida albicans on conventional media. We prospectively compared direct plating of sputum and urine onto birdseed agar and compared birdseed agar plating with plating onto Mycosel and Sabouraud dextrose agar cultures. Thirty-two sputum and three urine specimens were compared. C. neoformans was isolated from five specimens. In two specimens, one of sputum and one of urine, C. neoformans was detected only on the birdseed agar plate because of overgrowth on the conventional media by C. albicans. C. neoformans produced dark colonies on birdseed agar, unlike C. albicans, which produces white colonies. The use of birdseed agar as the primary culture medium for sputum and urine specimens from patients with acquired immunodeficiency syndrome increases sensitivity for C. neoformans.
Effect of BiTek agar on lysostaphin susceptibility of staphylococci
Authors: Langlois B E , Dawson K , Akers K
Published: January 2020

Staphylococci which were considered to be lysostaphin susceptible on P agar containing Bacto-Agar showed different degrees of resistance to lysostaphin when tested on P agar made with BiTek agar. As a result, lysostaphin-susceptible strains were misidentified as lysostaphin-resistant strains.
Modified Feist broth as a serum-free alternative for enhanced production of protective antigen of Erysipelothrix rhusiopathiae
Authors: Groschup M H , Timoney J F
Published: January 2020

The production of protective antigen in modified serum-free nutrient broth (H. Feist, K.-D. Flossmann, and W. Erler, Arch. Exp. Veterinaermed. 30:49-57, 1976) and in brain heart infusion broth supplemented with 10% horse serum (BHIS) was evaluated for six strains of Erysipelothrix rhusiopathiae serotypes 1a, 2, 2b, 4, and N. All six strains grew to higher cell densities in modified Feist medium than in BHIS and produced larger amounts of 64,000- to 66,000- and 39,000- to 40,000-molecular-weight antigens involved in immunity to erysipelas. A vaccine produced in Feist medium from E. rhusiopathiae SE-9 (serotype 2) was highly effective in a mouse protection test. We therefore suggest that modified Feist medium is an excellent, if not superior, alternative to BHIS for production of erysipelas vaccine.
Ability to bind salivary alpha-amylase discriminates certain viridans group streptococcal species
Authors: Kilian M , Nyvad B
Published: January 2020

A collection of 144 viridans group streptococcal strains recently characterized as part of a taxonomic study was examined for the ability to bind salivary alpha-amylase. This property was found in most strains of Streptococcus gordonii and Streptococcus mitis and in occasional strains of Streptococcus anginosus and Streptococcus salivarius. In contrast, all strains of Streptococcus sanguis, Streptococcus oralis, Streptococcus vestibularis, and Streptococcus mutans lacked alpha-amylase-binding capacity. A rapid and easy assay described in this paper may be an important supplementary test for identification of oral streptococci.
Differential production of slime under aerobic and anaerobic conditions
Authors: Barker L P , Simpson W A , Christensen G D
Published: January 2020

A series of 37 clinical isolates of coagulase-negative staphylococci previously identified as negative for slime production by the tube test were reexamined by the tissue culture plate test under aerobic and anaerobic conditions. None of the strains produced slime under anaerobic conditions; however, five strains (13%) produced slime under aerobic conditions.
Evaluation of lipoarabinomannan for the serological diagnosis of tuberculosis
Authors: Sada E , Brennan P J , Herrera T , Torres M
Published: January 2020

The availability of highly purified lipoarabinomannan from Mycobacterium tuberculosis in its native acylated, highly antigenic state allowed its application to the serodiagnosis of tuberculosis in patients from the Republic of Mexico. Antilipoarabinomannan immunoglobulin G antibodies in sera from 66 patients with pulmonary, miliary, and pleural tuberculosis and tuberculosis lymphadenities were measured by using the enzyme-linked immunosorbent assay against sera from a control population of healthy individuals, people with histoplasmosis, and people with lung diseases not caused by mycobacteria. The results pointed to an unexpectedly high degree of specificity of 91% and a sensitivity of 72%, comparable to figures from previous studies with other purified antigens; most of the false-positive results were for patients with histoplasmosis. Thus, lipoarabinomannan of M. tuberculosis is a potentially useful antigen for the serodiagnosis of tuberculosis.
Trivalent heat-labile- and heat-stable-enterotoxin probe conjugated with horseradish peroxidase for detection of enterotoxigenic Escherichia coli by hybridization
Authors: Abe A , Komase K , Bangtrakulnonth A , Ratchtrachenchat O A , Kawahara K , Danbara H
Published: January 2020

A 1,268-bp polynucleotide probe for heat-labile and heat-stable enterotoxins (LTh, STIa, STIb) was conjugated with horseradish peroxidase (HRP). The HRP-conjugated trivalent probe was applied to the detection of enterotoxigenic Escherichia coli (ETEC) by colony and stool hybridizations. The binding of the probe to its targets was assayed by the addition of HRP substrates hydrogen peroxide and luminol in the presence of an enhancer, and the chemiluminescence was recorded by exposure to X-ray film. Slot blot hybridization demonstrated that the HRP-conjugated trivalent probe specifically hybridized with the DNA isolated from ETEC strains. The trivalent probe also specifically identified bacterial colonies of ETEC that produced LTh, STIa, STIb, LTh-STIa, or LTh-STIb. Treatment of targets with sodium dodecyl sulfate and proteinase K remarkably reduced nonspecific hybridization to DNAs of non-ETEC strains. Furthermore, this probe was able to detect stool specimens seeded with 10(2) original ETEC cells per 5 mg of feces. These results suggest that the HRP-conjugated trivalent probe is a candidate for use in the clinical laboratory to detect ETEC.