bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of rapid urease tests, staining techniques, and growth on different solid media for detection of Campylobacter pylori
Authors: Coudron P E , Kirby D F
Published: January 2020

Thirty-nine single antral biopsies (phase 1) and 99 sets of six antral biopsies (phase 2) were collected from 132 patients, and 87 (63%) yielded positive cultures for Campylobacter pylori. Of several primary media tested in phase 1, tryptic soy agar and Skirrow agar, each supplemented with 10% whole sheep blood, supported relatively good growth of C. pylori. In phase 2, four of the six biopsies in each set were tested with different urease systems. Selective urea agar for rapid identification was the most sensitive (39 of 63 [62%] at 1 h) and specific (100%); however, the difference between this system and the CLOtest was not statistically significant. The remaining two biopsies, one transported in saline and the other transported in a supplemented tryptic soy broth, were ground separately and inoculated onto tryptic soy agar and Skirrow agar, each supplemented with 10% whole sheep blood. In selected instances, 10% horse serum or 10% horse serum and 5 mM urea or 1% cholesterol were also added to the media. Smears stained with a modified Gram stain or acridine orange detected 68% of 63 culture-positive biopsies; no false-positive results were reported. Skirrow agar supported better growth of C. pylori than did tryptic soy agar; the nonselective medium was also overgrown with contaminants in 25 to 30% of the positive cultures. Based on colony size, Skirrow agar supplemented with 10% whole sheep blood, 10% horse serum, and 1% cholesterol supported optimal growth of C. pylori. Fresh media supported better growth than did prepoured commercial media (P less than or equal to 0.004). Saline was a convenient and satisfactory transport medium for antral biopsies.
Application of gas-liquid chromatography to the routine identification of nonfermenting gram-negative bacteria in clinical specimens
Authors: Veys A , Callewaert W , Waelkens E , Van den Abbeele K
Published: January 2020

A total of 430 strains of glucose-nonfermenting gram-negative bacteria representing 35 species were analyzed for their cellular fatty acid composition by gas-liquid chromatography (GLC). On the basis of qualitative differences in their cellular fatty acid composition, these bacteria could be divided into 19 distinct chromatographic groups. Eight Pseudomonas species, Achromobacter xylosoxidans, group Vd, and Agrobacterium radiobacter were identified from their fatty acid compositions alone. The other glucose-nonfermenting gram-negative bacterial species studied here, classified within nine distinct GLC groups, were easily recognized by using the GLC fatty acid analysis supplemented with a limited number of conventional biochemical tests. The results support the hypothesis that bacterial fatty acid composition is rather specific and that qualitative GLC fatty acid analysis can be adapted in the clinical laboratory either to provide additional criteria for differentiation of closely related groups or to serve as a rapid and highly reproducible method for their routine identification.
Subclass compositions of immunoglobulin G to pertussis toxin in patients with whooping cough, in healthy individuals, and in recipients of a pertussis toxoid vaccine
Authors: Zackrisson G , Lagergård T , Trollfors B
Published: January 2020

The subclass composition of serum immunoglobulin G (IgG) antibodies against pertussis toxin was studied in 108 serum samples obtained during various stages of disease from 75 patients with whooping cough. IgG1 and IgG3 antibodies were detected in 92 and 42% of the samples, respectively, while only a few contained IgG2 or IgG4 antibodies. Similarly, IgG1 antibodies were predominant in serum samples from healthy children and adults, many of whom had a history of whooping cough several years earlier. Of 85 children and 30 adults with detectable levels of total IgG, 65 and 14 had IgG1 antibodies, respectively, while only 9 of them had IgG3 antibodies. Again, very few sera contained IgG2 or IgG4 antibodies. In contrast, 13 children vaccinated with an acellular aluminum-adsorbed pertussis toxoid vaccine responded mainly with IgG1 and IgG4 antibodies. In conclusion, this study showed that the subclass composition of IgG antibodies to pertussis toxin after natural infection consists mainly of IgG1 and to a certain extent of IgG3, while an aluminum-adsorbed pertussis toxoid induces IgG1 and IgG4 antibodies.
Development of a diagnostic test for Johne's disease using a DNA hybridization probe
Authors: Hurley S S , Splitter G A , Welch R A
Published: January 2020

A DNA probe, M13 mpHAW71, that detects Mycobacterium paratuberculosis in the fecal material of infected animals was developed for use in the diagnosis of Johne's disease. The probe detected as few as 10(5) M. paratuberculosis when hybridized under stringent conditions to total genomic DNA purified from bovine fecal material. When the probe was used diagnostically, it did not differentiate members of the Mycobacterium avium-M. intracellulare-M. paratuberculosis complex. Compared with culturing, the DNA probe identified 34.4% more mycobacterium-containing fecal samples, and testing took only 72 h to complete.
Effect of delay in processing on lysis-centrifugation blood culture results from marrow transplant patients
Authors: Hamilton D J , Amos D , Schwartz R W , Dent C M , Counts G W
Published: January 2020

The effect of delay in processing on results of lysis-centrifugation (LC; Isolator) blood cultures was assessed in 4,577 paired blood specimens. Blood specimens were obtained at all hours from 384 febrile marrow transplant patients with indwelling venous catheters and were processed by the LC technique and by a conventional two-bottle method. Most patients (84%) were receiving broad-spectrum antibiotics at the time of blood culture. Specimens were delivered to the laboratory, where Isolator tubes were held at 35 degrees C and processed in batches between 0700 and 1730 h daily. This procedure resulted in a delay beyond the manufacturer-suggested processing time of less than 8 h for 1,853 (42%) of the LC cultures. There was no overall difference in the recovery of organisms present in LC cultures processed after being held for 8 to 24 h compared with the conventional two-bottle method. LC methodology had shorter time to detection than the conventional method for detection of Candida spp. and Pseudomonas spp. (P less than 0.05). However, time to detection for Streptococcus spp. and members of the family Enterobacteriaceae, responsible for 16.3% of total isolates, was prolonged significantly by delay in processing when compared with the conventional two-bottle method (P less than 0.01). Results of this study support the recommendation of the manufacturer for processing of Isolator tubes within 8 h or less. Although one can safely delay processing beyond 8 h in terms of total recovery of organisms, such delays were associated with longer time to detection for certain important potentially pathogenic organisms which accounted for a sizeable proportion of blood culture isolates from marrow transplant patients.
Antigen-antibody reaction in solution in capture competition immunoassay for human immunodeficiency virus antibodies
Authors: Nielsen C M , Kvinesdal B , Vestergaard B F
Published: January 2020

In the capture competition immunoassay, undiluted serum was reacted in solution with purified human immunodeficiency virus (HIV) antigen in wells of microtest plates coated with anti-HIV immunoglobulin G antibodies (HIV capture antibodies). HIV antibodies present in the serum being tested combined with the HIV antigen and thus blocked (completely or partially) the fixation of the antigen to the capture layer. Unblocked antigenic activity was measured in subsequent steps by the use of biotinylated anti-HIV immunoglobulin G and peroxidase-conjugated avidin. The assay was evaluated in comparison with indirect enzyme-linked immunosorbent assay and Western (immuno-) blot (WB). A total of 180 serum samples which reacted repeatedly as positive in indirect enzyme-linked immunosorbent assay but negative in WB were found to be negative by the capture competition assay. Of 54 serum samples showing dubious reactions (single p24 bands in WB), 53 were clearly separated into positive or negative reactions, whereas 1 serum sample gave a borderline reaction. It was concluded that a characteristic feature of this kind of inhibition assay is a very low frequency of equivocal results.
Sensitive receptor-specified enzyme-linked immunosorbent assay for Escherichia coli verocytotoxin
Authors: Basta M , Karmali M , Lingwood C
Published: January 2020

The specific identification of verocytotoxin (VT)-producing Escherichia coli (VTEC) requires the detection of VTs in bacterial culture filtrates or the detection of genes encoding these toxins in bacterial cells by specific DNA probes. The standard method for detecting these toxins involves a time-consuming, labor-intensive, and expensive cytotoxicity assay. We have developed a specific, highly sensitive receptor-specified enzyme-linked immunosorbent assay (RELISA) to detect VT1, one of at least two VTs implicated in human disease. The assay is based on the affinity of VT1 for the glycolipid globotriosyl ceramide (Gb3). Gb3 was de-N-acylated to yield lyso-Gb3, which is more polar but retains VT1 binding. Lyso-Gb3 was used to sensitize microdilution plates to bind VT1 for subsequent immunodetection. This RELISA was used to detect VT1 in the culture supernatant of a variety of bacteria of known VT status. The assay was compared with the highly sensitive cell cytotoxicity assay for their abilities to detect VT. The RELISA was as sensitive as the cytotoxicity assay and, in a blind study, 100% specific. This assay will provide a quick, specific, efficient adjunct to the diagnosis and epidemiological study of VTEC infections and their relationship to human disease.
Double-label immunofluorescence method for simultaneous detection of adenovirus and herpes simplex virus from the eye
Authors: Walpita P , Darougar S
Published: January 2020

The development and application of a double-label immunofluorescence method which has the potential to screen for single or dual infections from any site, in single shell vial cultures, is described. In this study, a total of 1,141 ocular specimens were inoculated in shell vials, centrifuged at 15,000 X g for 1 h, incubated at 37 degrees C for 48 h, and fixed in methanol at room temperature for 15 min. The virus inclusions were detected by staining with a double-label indirect immunofluorescence procedure using mixtures of appropriate first antibodies, followed by fluorescein- and rhodamine-conjugated second antibodies. Each specimen was also inoculated in parallel by the conventional virus isolation method. The sensitivity and specificity of the double-label shell vial procedure were comparable to those with the conventional method, and the former test took only 48 h to complete. The test offers a rapid and simple single-vial procedure which allows for individual or simultaneous detection of multiple pathogens. It results in savings in time and cost over the conventional virus isolation method and other shell vial procedures.
Staphylococcus aureus exopolysaccharide in vivo demonstrated by immunomagnetic separation and electron microscopy
Authors: Johne B , Jarp J , Haaheim L R
Published: January 2020

Staphylococcus aureus strains were separated from mastitis milk samples without cultivation by using monodisperse magnetic polymer particles coated with polyclonal antiserum against an encapsulated S. aureus strain. Exopolysaccharide was verified by transmission electron microscopy and the serum soft-agar culture technique. Capsular polysaccharide was found on virtually all clinical isolates. Surface protein A and S. aureus-specific cell wall components were masked when the strains were cultured on an exopolysaccharide-promoting medium. Masking of surface determinants was dependent on their concentration on the bacterial surface as well as on exopolysaccharide abundance. The polysaccharide layer on in vivo bacteria was reduced markedly after just one transfer from milk to blood agar plates but was reexpressed after culturing was done on a capsule-generating medium.
L-form-like colonies of Staphylococcus aureus induced by an extracellular lytic enzyme from Pseudomonas aeruginosa
Authors: Falcon M A , Mansito T B , Carnicero A , Gutierrez-Navarro A M
Published: January 2020

An extracellular enzyme produced by Pseudomonas aeruginosa had a lytic effect on lyophilized Staphylococcus aureus cells. It was purified from the culture supernatant by ammonium sulfate fractionation followed by column chromatography with P cellulose and Sephadex G-50. The molecular weight of the enzyme was estimated to be 19,000 +/- 1,750 with sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The pI of the enzyme was estimated to be 8.5 with isoelectric focusing. The enzyme was inactive in 4% NaC1-40 mM sodium phosphate buffer or at pH values lower than 6.0 or higher than 11.0; however, it was not affected by 1 M sucrose or 0.25% heat-denatured horse serum. The action of the enzyme on cultures of S. aureus resulted in the presence of many cells lacking cell walls. In addition, when cultivation was carried out on osmotically stabilized solid media, these cell wall-deficient cell developed in L-form colonies.
Long-term storage of Campylobacter pylori
Authors: Drumm B , Sherman P
Published: January 2020

A reproducible method for long-term storage of Campylobacter pylori has been previously described. We cultured 10 strains of C. pylori in brucella broth that was supplemented with 10% fetal bovine serum. After incubation for 24 h, 10% glycerol and an additional 10% fetal bovine serum were added to the cultures, which when then held in storage at -70 degrees C. After 6 months, each of the strains remained viable. This technique, therefore, represents an excellent method for long-term storage of C. pylori isolates.
Evaluation of the pacific biotech CARDS STREP A test for detecting group A streptococci from cases of pharyngitis
Authors: Manasse R J
Published: January 2020

The Pacific Biotech CARD STREP A test for rapid screening of throat specimens for group A streptococci was evaluated. Relative to conventional culture, this assay had a sensitivity of 76.1% (108 of 142) and a specificity of 98.7% (392 of 397). The relatively low sensitivity of the test makes it of questionable value as a screening procedure.
Latex agglutination test for detection of Escherichia coli serotype O157
Authors: March S B , Ratnam S
Published: January 2020

The value of a latex agglutination test (Escherichia coli O157 latex test; Oxoid Ltd.) for rapid presumptive detection of E. coli serotype O157:H7 was determined by laboratory trials and during an outbreak of hemorrhagic colitis. The latex test was found to be a simple, highly efficient and reliable test in detecting E. coli O157:H7 with 100% sensitivity and specificity. It was also found that sorbitol-MacConkey agar cultures were not as useful for food samples as they were for fecal specimens in screening for E. coli O157:H7, but the use of the latex screen was particularly efficient in this setting.
Characteristic bacteriolytic activities of Staphylococcus hyicus
Authors: Lämmler C
Published: January 2020

Staphylococcus hyicus demonstrated characteristic bacteriolytic activities towards a Micrococcus luteus reference strain. This lytic activity was demonstrated on medium containing M. luteus cells as large zones of transparency around the culture streak. Smaller zones of transparency were observed with Staphylococcus intermedius, Staphylococcus chromogenes, and some strains of Staphylococcus aureus but not with other coagulase-negative staphylococcal species. The distribution and extent of the bacteriolytic activity could be useful as additional criteria for differentiation of S. hyicus.
Saccharomyces cerevisiae pneumonia in a patient with acquired immune deficiency syndrome
Authors: Tawfik O W , Papasian C J , Dixon A Y , Potter L M
Published: January 2020

The clinical course of a patient with a polymicrobial pneumonia that included Saccharomyces cerevisiae infection is described. S. cerevisiae was recovered from autopsy cultures of the lungs, spleen, oral mucosa, and small intestine, and organisms morphologically consistent with S. cerevisiae were visualized in histologic sections of the lung. The role of this organism as a human pathogen is reviewed.
Campylobacter cinaedi is normal intestinal flora in hamsters
Authors: Gebhart C J , Fennell C L , Murtaugh M P , Stamm W E
Published: January 2020

During the course of studies to reproduce proliferative enteritis in hamsters, Campylobacter cinaedi was recovered from the feces of the majority of healthy hamsters obtained from two commercial sources. The organisms were cultured by using filtration, a nonselective medium, and a microaerophilic atmosphere containing hydrogen. Isolation was hindered by the fastidious nature of C. cinaedi and by the presence of other Campylobacter species in the hamster intestine. All hamster C. cinaedi isolates were phenotypically similar to C. cinaedi ATCC 35683. Comparison of whole-cell protein profiles of one hamster isolate with a reference strain of C. cinaedi by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunoblotting with C. cinaedi-specific rabbit antiserum supported the phenotypic identification of these isolates. Hamsters may be an animal reservoir for human C. cinaedi infections.
Comparison of the Directigen 1-2-3 Group A Strep Test with culture for detection of group A beta-hemolytic streptococci
Authors: Huck W , Reed B D , French T , Mitchell R S
Published: January 2020

The Directigen 1-2-3 Group A Strep Test (DGAST; BBL Microbiology Systems, Cockeysville, Md.) was compared with conventional culture procedures on Trypticase soy agar with 5% sheep blood (BBL) and Selective Streptococcal Agar (ssA; BBL) for detection of group A beta-hemolytic streptococci (GABHS) for 1,006 patients complaining of sore throat. The DGAST was performed at five acute-care clinics according to the instructions of the manufacturer; interpretation of the cultures was done at the central microbiology laboratory. Of 924 patients with complete data, 243 (26.3%) were positive for GABHS on culture when both sheep blood agar and ssA were used. Of the patients with positive cultures, 159 were detected by the DGAST, yielding a sensitivity of 65.4%, a specificity of 84.7%, a positive predictive value of 60.5%, and a negative predictive value of 87.3%. The greater the number of colonies on culture, the greater the sensitivity of the DGAST, and the more intense the positive reaction on the DGAST, the higher the positive predictive value of the test. For the identification of GABHS, sheep blood agar was superior to ssA by 12.9% at 24 h and by 3.4% at 48 h of incubation.
Improved growth of Campylobacter pylori in a biphasic system
Authors: Shadowen R D , Sciortino C V
Published: January 2020

The recovery of Campylobacter pylori from clinical specimens is difficult, even when done with an optimal medium, atmosphere, and temperature. The growth of this organism was investigated by comparing a biphasic system with broth culture. The effects of gyration, inoculum, and pH were studied. Brucella agar and broth supplemented with 2.5% fetal bovine serum were used. Growth in the biphasic system was an average of 2 log units (7 X 10(8) versus 5 X 10(6) CFU/ml) greater than that in the broth system (P less than 0.01), and this occurred 12 to 24 h sooner in the biphasic system. When gyration was added, an average of 1 log unit of growth improvement was seen in comparable systems. Improved growth was also seen with low inoculum levels, in which stationary-phase cells in the broth system reached 10(5) CFU/ml compared with 10(7) CFU/ml in the biphasic system. At the three pH ranges studied, growth was best at pH 8 to 9 (6 X 10(9) CFU/ml), averaging 2 log units greater growth than that at pH 6 to 7 and 4 log units greater growth than that at pH 4.5 to 5.5 (P less than 0.01). The improved recovery of the organism for low inoculum levels in a biphasic system may be important for long-term storage and clinical isolation.
Pulmonary persistence of Haemophilus somnus in the presence of specific antibody
Authors: Gogolewski R P , Schaefer D C , Wasson S K , Corbeil R R , Corbeil L B
Published: January 2020

Chronic experimental Haemophilus somnus pneumonia was produced in five 8- to 12-week-old calves to investigate host-parasite relationships in the respiratory tract. Calves were depressed and pyrexic and coughed intermittently for 3 days and then recovered except for sporadic coughing. Bacteria persisted in the lung for 6 to 10 weeks or more. Immunoglobulin G1 (IgG1), IgG2, and IgM but no IgA antibodies specific for H. somnus were detected in serum. Bronchoalveolar lavage samples contained detectable IgG1, IgG2, IgM, and IgA antibodies specific for H. somnus throughout most of the experiment. The kinetics of the isotypic antibody response against H. somnus in serum and bronchoalveolar lavage fluids differed, suggesting that both local and systemic antibody responses had occurred. Persistence of pulmonary infection for 10 weeks or more in the presence of antibody may be due to an inappropriate distribution of isotypes, toxicity of H. somnus for bovine macrophages, and perhaps other factors. Three of the calves were challenged with a 10-fold-higher dose of H. somnus at 10 weeks after the original inoculation. Immunity against H. somnus was indicated by the rapid clearance of bacteria from the lungs and the presence of minimal pneumonia at necropsy 3 days after bacterial challenge.
Identification of EF group 22 campylobacters from gastroenteritis cases as Campylobacter concisus
Authors: Vandamme P , Falsen E , Pot B , Hoste B , Kersters K , De Ley J
Published: January 2020

EF (E. Falsen) group 22, a group of Campylobacter strains sorted out by routine immunotyping among unidentified or misidentified human nonoral clinical specimens, was characterized by numerical analysis of gel electrophoretic protein profiles and immunotyping. The protein electrophoretic and immunotyping analyses, DNA:DNA hybridizations, and the DNA base composition demonstrated unambiguously that all EF group 22 strains belong to Campylobacter concisus. EF group 22 strains have DNA binding values of at least 42% with the type strain of C. concisus, showing a considerable degree of genomic heterogeneity. The isolation from blood, esophagus, stomach, duodenum, and feces of humans in association with different gastrointestinal disorders considerably extends the clinical significance of this species. Our results indicate that sodium dodecyl sulfate-polyacrylamide gel electrophoresis and immunotyping are excellent tools for the identification of the fastidious C. concisus strains and relatives.
Enzyme-linked immunosorbent assays for detection of immunoglobulin M to nontreponemal and treponemal antigens for the diagnosis of congenital syphilis
Authors: Pedersen N S , Sheller J P , Ratnam A V , Hira S K
Published: January 2020

Sera from newborn infants born of mothers with a high risk of syphilis were examined for immunoglobulin M (IgM) antibodies in two different enzyme-linked immunosorbent assays (ELISAs), using either purified flagella from Treponema phagedenis biotype Reiter or the Venereal Disease Research Laboratory (VDRL) antigen as the antigen. All sera were also examined by the fluorescent treponemal antibody absorption (FTA-ABS) test for IgM. Three different groups of patients were studied. Group 1 consisted of 84 women and their newborn infants from a high-risk population for syphilis. Congenital syphilis was diagnosed in one child who had an IgM-positive cord blood specimen in both the ELISA and the FTA-ABS test. Group 2 consisted of 10 mothers and their newborn children. All mothers had positive syphilis-screening tests, and all children had signs of congenital syphilis. All but one child had positive IgM tests. Group 3 consisted of 15 mothers and their newborn children. These mothers had been treated for syphilis late in pregnancy, and all had a positive screening test at delivery. Two of the children had positive IgM tests, probably caused by reactivity after late intrauterine treatment of congenital syphilis. The specificities of the IgM tests were high when evaluated with sera from newborn children without signs of congenital syphilis. Even though IgM rheumatoid factor was found in all of the children tested with definite congenital syphilis, the rheumatoid factor did not cause false-positive results in either the VDRL ELISA or the flagellum ELISA. No significant IgG-IgM competition was noticed in the ELISAs. This study also confirmed that IgA antibodies do not cross the placenta; most newborn children with congenital syphilis were positive in the VDRL ELISA for IgA. Both the VDRL ELISA and the flagellum ELISA are very useful in the diagnosis of congenital syphilis and may be substitute for the FTA-ABS test. The VDRL ELISA for IgM will be especially useful in developing countries with a high incidence of congenital syphilis.
Use of an rRNA probe and restriction endonuclease analysis to fingerprint Pasteurella multocida isolated from turkeys and wildlife
Authors: Snipes K P , Hirsh D C , Kasten R W , Hansen L M , Hird D W , Carpenter T E , McCapes R H
Published: January 2020

Twenty-five isolates of the bacterium Pasteurella multocida were characterized (fingerprinted) phenotypically and genotypically in order to compare the abilities of various techniques to differentiate strains for epidemiologic studies of fowl cholera. Isolates were obtained over a 16-month period from turkeys dying from fowl cholera (six outbreak flocks) and from wildlife captured on premises with a history of the disease. The characteristics compared included (i) serotype, (ii) subspecies, (iii) antibiogram, (iv) presence of plasmid DNA, (v) restriction endonuclease analysis patterns of whole-cell DNA, and (vi) ribotype. Ribotyping, a method of highlighting DNA restriction site heterogeneity by using an rRNA probe, worked well for differentiating the strains of P. multocida when the majority of the other techniques could not. Ribotyping results correlated directly with and confirmed results obtained from restriction endonuclease analysis. Ribotyping demonstrated the presence of up to three strains of P. multocida in one outbreak flock, recurrence of a single strain in five of the flocks over an 11-month period, and the presence of common strains in turkeys and wildlife on the premises.
Fluoroimmunoassay studies with solubilized antigens from Borrelia burgdorferi
Authors: Hechemy K E , Harris H L , Wethers J A , Stevens R W , Stock B R , Reilly A A , Benach J L
Published: January 2020

Sodium deoxycholate-solubilized Borrelia burgdorferi antigen was prepared for use in a solid-phase fluoroimmunoassay (FIA-L) to detect antibodies in Lyme disease. Serum specimens were tested by FIA-L and by a microimmunofluorescence test. The FIA-L results are comparable to those of the standard microimmunofluorescence test. The overall agreement was 0.98. Moreover, the FIA-L procedure is simple and rapid; fluorescence is objectively determined and is proportional to antibody titer.
Cytobrush in collection of cervical specimens for detection of Chlamydia trachomatis
Authors: Moncada J , Schachter J , Shipp M , Bolan G , Wilber J
Published: January 2020

Methods of collecting endocervical samples for the detection of Chlamydia trachomatis were evaluated. We compared Calgiswab and cytobrush for isolation in cell culture and Dacron swab and cytobrush for direct fluorescent-antibody (DFA) testing for 632 females attending a sexually transmitted disease clinic. An additional specimen for enzyme immunoassay (EIA) was also collected. True-positives were identified as tissue culture positive and/or both DFA and EIA positive. Use of the cytobrush significantly improved the sensitivity of both the culture (69% with swab and 100% with cytobrush) and DFA testing (68% with swab and 85% with cytobrush). The EIA sensitivity was 85%. The specificity of each test was greater than or equal to 98%. The cytobrush appears to be the superior method for the collection of cervical samples from nonpregnant women.
Quantification and toxicity of group A streptococcal pyrogenic exotoxins in an animal model of toxic shock syndrome-like illness
Authors: Lee P K , Schlievert P M
Published: January 2020

Toxic shock-like syndrome isolates of group A streptococci were evaluated for production of pyrogenic exotoxins (also called SPEs, scarlet fever toxins, and erythrogenic toxins). The isolates were consecutively obtained during 1987 and 1988. Of these isolates, 23 of 26 made SPE type A, 10 of 26 made SPE B, and 8 of 26 made SPE C. SPE A was produced in significantly greater amounts than SPEs B and C (3.2 micrograms/ml of culture fluid compared with 0.7 and 0.6 microgram/ml, respectively). SPE A, administered in miniosmotic pumps implanted subcutaneously in rabbits, was significantly more toxic than SPE C; seven of eight rabbits succumbed after challenge with 150 or 300 micrograms of SPE A, compared with one of six after challenge with SPE C.
Vibrio cholerae non-serogroup O1 cystitis
Authors: Dumler J S , Osterhout G J , Spangler J G , Dick J D
Published: January 2020

We report a case of a patient who developed cystitis caused by non-serogroup O1 Vibrio cholerae after swimming in the Chesapeake Bay. Treatment was empirical, with complete symptomatic resolution. Genitourinary tract infections by Vibrio spp. are uncommon but should be considered when cystitis occurs after saltwater exposure in appropriate geographic regions.
Case report of Plesiomonas shigelloides-associated persistent dysentery and pseudomembranous colitis
Authors: van Loon F P , Rahim Z , Chowdhury K A , Kay B A , Rahman S A
Published: January 2020

An adult Bangladeshi woman had persistent bloody diarrhea. Repeated stool cultures yielded Plesiomonas shigelloides in pure growth. Tissue specimens of the colon were consistent with pseudomembranous colitis. Treatment with tetracycline, to which the isolate was susceptible, brought prompt recovery; the stool cultures became negative and the serum antibody titer against P. shigelloides lipopolysaccharide, as measured by hemagglutination inhibition with P. shigelloides lipopolysaccharide-sensitized sheep erythrocytes, declined from 1:160 to 1:40.
Detection of cytomegalovirus in peripheral leukocytes by different methods
Authors: Wunderli W , Kägi M K , Grüter E , Auracher J D
Published: January 2020

Screening leukocytes for cytomegalovirus (CMV) by shell vial assay gave unsatisfactory results. Of 10 positive specimens (114 samples), only 2 showing CMV could be detected. Disruption of leukocytes prior to their use in shell vial assays increased the sensitivity of CMV detection considerably: of 32 leukocyte specimens from transplant patients with signs of CMV disease, 13 were positive with disruption and only 3 were positive without. With this modification, 17 transplant patients with suspected CMV infection were regularly screened. Viremia could be detected in 10 cases by the shell vial assay and in 11 cases by the direct detection of immediate early antigen. On the average, viremia was detected 11 days before immunoglobulin M or typical clinical symptoms.
Immunoglobulin A antibody response to respiratory syncytial virus structural proteins in colostrum and milk
Authors: Tsutsumi H , Honjo T , Nagai K , Chiba Y , Chiba S , Tsugawa S
Published: January 2020

Immunoglobulin A (IgA) antibody response to respiratory syncytial virus (RSV) structural proteins in colostrum and milk was investigated by a radioimmunoprecipitation assay. By using [35S]methionine-labeled RSV-infected HEp-2 cells and antiserum to human IgA as the capture antibody, IgA antibody responses to large glycoprotein, fusion protein, nucleoprotein, phosphoprotein, and matrix protein were demonstrated in colostrum and milk. The IgA antibody response was mainly directed against fusion protein, whereas IgA activity against matrix protein was more variable and was not comparable to the antibody responses to other structural proteins. Maternal mammary IgA response after RSV infection in the infant was monitored in four cases, and the appearance of anti-RSV IgA activity against several RSV structural proteins was observed in convalescent-stage milk samples of two mothers in whom RSV infection was demonstrated.
Purification of an Escherichia coli serogroup O157:H7 verotoxin and its detection in North American hemorrhagic colitis isolates
Authors: Dickie N , Speirs J I , Akhtar M , Johnson W M , Szabo R A
Published: January 2020

Verotoxin (VT), which is immunologically unrelated to VT1 (Shiga-like toxin I), was purified from the culture filtrate of Escherichia coli hemorrhagic colitis serogroup O157:H7 strain 3657 by copper ion chelate affinity chromatography followed by anion-exchange chromatography. The isoelectric point by sucrose density gradient isoelectric focusing was 5.0, the molecular weight by gel filtration on Superose 12 was about 60,000, and the 50% cytopathic dose for Vero cells was about 1 pg. This toxin was found by immunological methods to be the predominant VT in E. coli O157 isolates associated with illness in North America, with 38 of 42 strains tested producing this toxin, 20 in combination with VT1. VT from strain 3657 is immunologically identical to the described Shiga-like toxin II (VT2) of E. coli strains (from the United States) K-12(pEB1) and C600(933W) but only partially related to VT of strain E32511 (from the United Kingdom), the first to be named VT2.
Stool diagnosis of giardiasis using a commercially available enzyme immunoassay to detect Giardia-specific antigen 65 (GSA 65)
Authors: Rosoff J D , Sanders C A , Sonnad S S , De Lay P R , Hadley W K , Vincenzi F F , Yajko D M , O'Hanley P D
Published: January 2020

A commercially available enzyme immunoassay for the diagnosis of giardiasis was evaluated in a clinical trial. The ProSpecT/Giardia diagnostic test (Alexon, Inc., Mountain View, Calif.) was compared with the standard ova and parasite (O&P) microscopic examination. Additionally, several widely used stool fixatives and a commonly used transport medium were assessed for compatibility with the immunoassay. A total of 325 stool specimens were collected and used to evaluate assay performance. Of those, 93 specimens were collected from symptomatic Giardia O&P-positive patients and 232 specimens were randomly collected from patients as part of a routine health screening procedure. All 93 Giardia O&P-positive stool specimens were strongly positive by visual and spectrophotometric examination using the immunoassay. Of the 232 randomly collected specimens, 16 were positive by O&P examination and immunoassay, 6 were negative by O&P examination but positive by immunoassay, and 1 was positive by O&P examination and negative by immunoassay. There was substantial supportive evidence that indicated that the six immunoassay-positive, O&P-negative specimens were true-positives. When these six specimens were accepted as true-positives, the immunoassay detected almost 30% more cases of Giardia infection than did O&P examination. Its sensitivity and specificity were 96 and 100%, respectively, while the sensitivity and specificity of O&P examination were 74 and 100%, respectively. The immunoassay also performed well on specimens treated with 10% neutral Formalin, sodium acetate-Formalin fixative, and Cary-Blair transport medium. However, the test was not compatible with polyvinyl alcohol-treated specimens. Overall, the ProSpecT/Giardia test was a sensitive, specific immunoassay which was easy to run and interpret. It offers a simple solution to traditional difficulties encountered in diagnosing Giardia infection.
New fluorescence assay for the quantitation of fungi
Authors: Coleman T , Madassery J V , Kobayashi G S , Nahm M H , Little J R
Published: January 2020

Quantitative determination of fungal mass is easily achieved with a new procedure that detects particle epifluorescence. Fungi are detected after exposure to a fluorescent stain (Fungiqual; CIBA-GEIGY Corp., Summit, N.J.) by using a fluorescence particle concentration analyzer. This report describes a simple fluorescence method for quantitation of either yeast or mycelial forms of fungi. The nature of the staining reaction was studied, and a practical application of this procedure for determination of fungal susceptibility to an antifungal agent is presented.
Toxoplasma antigens recognized by immunoglobulin G subclasses during acute and chronic infection
Authors: Huskinson J , Stepick-Biek P N , Araujo F G , Thulliez P , Suzuki Y , Remington J S
Published: January 2020

The immunoglobulin G (IgG) subclass response to Toxoplasma gondii antigens during the acute and chronic stages of T. gondii infection were studied by using immunoblots with reduced antigen (RA) and nonreduced antigen (NRA) preparations. Serum samples were from individuals with acute or chronic T. gondii infection, and sequential samples were from women who seroconverted during gestation and were treated with spiramycin. IgG1 antibodies were predominant in sera from each of the groups and recognized a large number of RA and NRA. In the latter group of patients, IgG1 and IgG3 were the first antibodies to appear in response to the infection. In all groups, an antigen with a molecular weight (MW) of 30,000 was the most intensely stained and frequently recognized by IgG1 antibodies in NRA preparations. In RA preparations, antigens of MW 35,000 and 30,000 were the most intensely stained and frequently recognized by IgG1 antibodies. An antigen with an MW of 22,000 was intensely stained in the IgG1 immunoblots of the NRA preparation and to a lesser extent in the RA preparation. In contrast to immunoblots with IgG1 antibodies, very few antigens in the RA and NRA preparations were detected by IgG2 and IgG3 antibodies; IgG4 antibodies rarely detected any antigens. Of interest was that IgG2 antibodies detected antigens distributed over the entire MW range, whereas those detected by IgG3 antibodies were located mostly below the 35,000 MW marker. Enzyme-linked immunosorbent assay results paralleled those of the immunoblots in that IgG1 antibodies were predominant.
Use of low-frequency-cleavage restriction endonucleases for DNA analysis in epidemiological investigations of nosocomial bacterial infections
Authors: Allardet-Servent A , Bouziges N , Carles-Nurit M J , Bourg G , Gouby A , Ramuz M
Published: January 2020

Epidemiological investigations of bacterial infections are generally based on multiple phenotypic markers that are often difficult to verify. A more general and reliable method is genomic DNA analysis by restriction endonucleases. However, the commonly used endonucleases produce too many fragments for correct separation by agarose electrophoresis. In contrast, simple electrophoretic patterns are obtained after genomic DNA digestion by low-frequency-cleavage restriction endonucleases and pulsed-field gel electrophoresis, making it easier to compare numerous strains from the same species. This technique was used to investigate an Acinetobacter calcoaceticus outbreak in a urologic department and bronchial colonization of artificially ventilated patients by Pseudomonas aeruginosa in an intensive care unit. The method allowed a clear distinction between epidemic and self-contaminating strains in these different epidemiological situations.
Quantitative western immunoblotting analysis in survey of human immunodeficiency virus-seropositive patients
Authors: Schiavini D G , Puel J M , Averous S A , Bazex J A
Published: January 2020

Identifying criteria for the early prediction of progression to acquired immunodeficiency syndrome in asymptomatic human immunodeficiency virus-seropositive patients have become necessary in order to widen the indications for antiviral treatment by azidothymidine and to increase its efficiency. With this aim in mind, we studied a cohort of seropositive homosexual men in the southwest region of France (Midi-Pyrénées). Of all the factors analyzed, the decline in p24 antibodies, assayed by second-generation enzyme-linked immunosorbent assay, was found to be the most reliable. On the basis of the work of Blomberg and Schmidt, we developed a quantitative approach to Western blotting (immunoblotting) for use in the follow-up of human immunodeficiency virus-infected patients. Our technique of quantitative Western blotting is unique because it uses a densitometric reading which, through a computerized system, gives a curve allowing the exact quantification of each stained Western blotting band. The results are expressed as integrals. This technique confirms the decrease in p24 and p17 antibodies as the criterion giving the earliest prediction of the progression to acquired immunodeficiency syndrome.
Prospective study of community-acquired rotavirus infection
Authors: Zheng B J , Lo S K , Tam J S , Lo M , Yeung C Y , Ng M H
Published: January 2020

We determined titers of group A rotavirus common antibodies and neutralizing antibodies against serotypes 1 to 4 of prototype human rotavirus (HRV) in cord blood and serum specimens obtained from 38 infants at 4-month intervals from birth until 2 years of age. Nineteen of the infants developed one episode of HRV diarrhea each, and they were matched by age and birth weight with the other 19 infants, who did not develop HRV diarrhea during the follow-up period. We estimated the incidence rate of HRV infection for the two groups of infants combined to be a minimum of 1.34 episodes per infant per year, which is 22 times more common than the occurrence of overt disease caused by the virus in this community. The infection occurred constantly throughout the first 2 years of infancy, whereas all but one of the 19 episodes of overt disease occurred before 12 months of age. Seven of these overt episodes were preceded by at least one episode of subclinical infection earlier, and the other seven were probably due to primary HRV infection. The remaining five episodes occurred before 4 months of age, so that we could not ascertain whether they were due to primary infections because of the presence of maternal antibodies. We showed that levels of HRV antibodies in serum specimens obtained before clinical onset of diarrhea varied widely, and, for most infants in the diarrheal group, levels of these antibodies were similar to those in the serum specimens obtained at the same times from the corresponding age- and birth weight-matched control infants. Nevertheless, the age at which overt disease caused by HRV was most prevalent coincided with the time when the maternal antibodies had declined to low levels but the infants had not yet acquired high titers of these antibodies in their sera.
Enterococci highly resistant to penicillin and ampicillin: an emerging clinical problem?
Authors: Sapico F L , Canawati H N , Ginunas V J , Gilmore D S , Montgomerie J Z , Tuddenham W J , Facklam R R
Published: January 2020

Sixteen clinical isolates of ampicillin-resistant enterococci (ARE) were recovered from the microbiology laboratory of a 450-bed rehabilitation medical center from January 1981 to September 1987. These isolates were detected when a disk diffusion test using 10 micrograms of ampicillin on a blood agar plate revealed no zones of inhibition. Tube macrodilution tests yielded an MIC of greater than or equal to 16 micrograms of ampicillin per ml. None of the isolates were penicillinase producers by the chromogenic cephalosporin disk test. Ten isolates were Enterococcus faecium, four isolates were E. raffinosus, one isolate was E. gallinarum, and one isolate was not identified (lost). There were 6 male and 10 female patients. The sources of isolates were urine (n = 7), wound (n = 5), ascitic fluid (n = 2), blood (n = 2), peritoneal catheter tip (n = 1), Bartholin's cyst abscess (n = 1), rectal swab (n = 2), and pancreatic abscess (n = 1). The organism was isolated from multiple sites in 4 patients, was a pure culture isolate in 5 patients, and was part of a polymicrobial flora in 11 patients. Six patients were diabetic, and four had liver cirrhosis. All but four patients had received at least one antibiotic within 3 weeks of ARE isolation. The MICs (micrograms per milliliter) for 50 and 90% of isolates tested, respectively, were as follows: ampicillin, 64 and 64; penicillin, 128 and greater than 128; vancomycin, 1 and 2; gentamicin, 4 and 16; ciprofloxacin, 1.6 and 3.2; imipenem, 128 and greater than 128; and daptomycin (LY146032), 1.6 and 6.4. ARE may be an emerging pathogen in the hospitalized patient population.
Pathogenicity in two cases of Staphylococcus schleiferi, a recently described species
Authors: Jean-Pierre H , Darbas H , Jean-Roussenq A , Boyer G
Published: January 2020

Staphylococcus schleiferi is a new species of coagulase-negative staphylococcus first described in April 1988 (J. Freney, Y. Brun, M. Bes, H. Meugnier, F. Grimont, P. A. D. Grimont, C. Nervi, and J. Fleurette, Int. J. Syst. Bacteriol. 38:168-172, 1988). There are few data in the literature on its pathogenicity. We report two cases in which its role as an opportunistic nosocomial appears to be incontestable.
Catheter infection caused by an unusual pathogen, Agrobacterium radiobacter
Authors: Potvliege C , Vanhuynegem L , Hansen W
Published: January 2020

The genus Agrobacterium is composed of several phytopathogenic species occurring worldwide in soils. One nontumorigenic species, Agrobacterium radiobacter, has occasionally been isolated from clinical specimens, but its pathogenic role in these cases has been difficult to ascertain since agrobacteria are usually isolated in association with other bacteria. We report the case of a central venous catheter infection and present the characteristics of A. radiobacter.
Species identification of Aeromonas strains based on carbon substrate oxidation profiles
Authors: Carnahan A M , Joseph S W , Janda J M
Published: January 2020

Twenty clinical strains each of Aeromonas hydrophila, Aeromonas caviae, and Aeromonas sobria were evaluated for their abilities to oxidize one or more of 95 carbon sources on a GN Microplate (BIOLOG, Hayward, Calif.). Nine substrates yielded good, discriminatory values for the three species tested. The panel appears to be useful for the species identification of Aeromonas isolates originating from human material.
Synthetic DNA probes for detection of enterotoxigenic Clostridium perfringens strains isolated from outbreaks of food poisoning
Authors: Van Damme-Jongsten M , Rodhouse J , Gilbert R J , Notermans S
Published: January 2020

Four synthetic oligonucleotides encoding different parts of the Clostridium perfringens enterotoxin gene were used to test the enterotoxigenicity of C. perfringens strains isolated from confirmed outbreaks of food poisoning. Of the 245 strains isolated from food and feces originating from 186 separate outbreaks, 145 (59%) gave hybridization reactions with each of the four DNA probes used, while 104 strains did not hybridize with any of the probes. There was no correlation between serotype and the presence of the enterotoxin gene, although the C. perfringens enterotoxin gene was rarely detected among nontypable strains (17%). Results show that DNA hybridization is a suitable method for the identification of C. perfringens strains which have the potential to produce enterotoxin.