bluuebunny/crossref_metadata_2025 huggingface dataset:
Diversity of plasmids in Achromobacter xylosoxidans isolates responsible for a seemingly common-source nosocomial outbreak
Authors: Arroyo J C , Jordan W , Lema M W , Brown A
Published: January 2020

Achromobacter xylosoxidans, an uncommon yet highly resistant opportunistic pathogen, was isolated from nine hospitalized patients during an 8-month period. It had been isolated from only seven patients with either nonfatal infection or colonization from 1981 to 1984. From June 1985 to January 1986, A. xylosoxidans was isolated 18 times from seven different sites (sputum, 7 times; urine, 4 times; blood, 3 times; and lung, pleural fluid, wound tissue, and tracheal aspirate, 1 time each). Four patients died, including the three with bacteremia. All but two patients had nosocomial infections and either were on the same ward or were cared for by the same staff members. Eleven A. xylosoxidans strains yielded eight distinct plasmids (8, 21, 23, 26, 38, 50, 51, and 64 megadaltons). Whole-cell peptide patterns of 10 of these strains were determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Isolates from the same patient contained the same plasmids and had identical peptide patterns but differed from other strains in both parameters. Plasmids were absent from the two community-acquired isolates. Although nosocomial strains showed similar antibiotic resistance patterns (only moxalactam and ticarcillin-clavulanic acid were uniformly active) and cross-contamination was strongly suggested epidemiologically, results of plasmid and peptide analyses did not support the possibility of a single-strain outbreak.
Monoclonal antibody typing of Chlamydia psittaci strains derived from avian and mammalian species
Authors: Fukushi H , Nojiri K , Hirai K
Published: January 2020

A total of 77 Chlamydia psittaci strains of avian, human, and mammalian origin were grouped into four serovars with 11 monoclonal antibodies recognizing the lipopolysaccharide and the major outer membrane protein antigens. The avian and human strains, which were closely related to each other, were distinct from the mammalian strains. Immunological typing of C. psittaci with monoclonal antibodies seems practical.
Phadebact Monoclonal GC OMNI Test for confirmation of Neisseria gonorrhoeae
Authors: Carlson B L , Calnan M B , Goodman R E , George H
Published: January 2020

The Phadebact Monoclonal GC OMNI Test (Pharmacia Diagnostics, Piscataway, N.J.) is used for the definitive identification of Neisseria gonorrhoeae. In this test, boiled organisms are examined by using a 1-min coagglutination technique. A total of 776 Neisseria strains, confirmed to the species level by patterns of acid production from carbohydrates incorporated in cysteine-tryptose agar or morphologically consistent with Neisseria meningitidis and fluorescent antibody negative, were tested by the coagglutination technique. Of the 516 isolates of N. gonorrhoeae, 8 (1.6%) were negative with the OMNI Test. Of the 260 isolates of Neisseria spp. other than N. gonorrhoeae, none showed a positive coagglutination reaction. The Phadebact Monoclonal GC OMNI Test provided rapid, accurate identification of N. gonorrhoeae (sensitivity, 98.4%; specificity, 100%).
Norwalk virus antigen and antibody response in an adult volunteer study
Authors: Gary G W , Anderson L J , Keswick B H , Johnson P C , DuPont H L , Stine S E , Bartlett A V
Published: January 2020

To better define the optimum timing of specimen collection and identify alternate ways to diagnose Norwalk virus outbreaks, we looked at the timing of the antibody response and virus excretion in a human volunteer study. The Norwalk virus antibody titers and antigen in stool specimens were examined by biotin-avidin immunoassay. Our data suggest that in epidemic situations, convalescent-phase sera could be collected as soon as 13 days after the onset of illness and acute-phase sera could be collected as late as 5 days after onset. Our data also suggest that if sufficient serum samples are collected, convalescent-phase case and control serum samples can be used to identify Norwalk virus outbreaks. Antigen detection was much less sensitive than seroconversion for detecting infection.
Puncture wound osteochondritis of the foot caused by CDC group Vd
Authors: Barson W J , Cromer B A , Marcon M J
Published: January 2020

A case of puncture wound osteochondritis of the foot caused by CDC group Vd is presented because of the unusual nature of the infecting organism. This organism may be confused with Pseudomonas aeruginosa, the usual pathogen responsible for this type of infection, but does not have a similar antimicrobial susceptibility profile. For this reason, it is important to obtain appropriate culture specimens and to identify and test the susceptibility of bacterial isolates from cases of puncture wound-associated osteochondritis so that optimal therapeutic regimens can be determined.
Bacteremia Caused by CDC Group Ve-1 in Previously Healthy Patient with Granulomatous Hepatitis
Authors: Engel J. Mark , Alexander Frederick S. , Pachucki Constance T.
Published: January 2020

This is a case report of CDC group Ve-1 bacteremia in an otherwise healthy patient with granulomatous hepatitis.
DNA probes for identification of enteroinvasive Escherichia coli
Authors: Gomes T A , Toledo M R , Trabulsi L R , Wood P K , Morris J G
Published: January 2020

Eighty-one Escherichia coli strains belonging to all known invasive O serogroups were tested with two distinct invasiveness probes (pMR17 and pSF55). All 54 Sereny test-positive strains and 5 strains that lost Sereny positivity during storage hybridized with both probes. Probe-positive strains carried a 120- to 140-megadalton plasmid, did not produce lysine decarboxylase, and, with the exception of certain serotypes, were nonmotile. Motile strains of serotype O144:H25 were for the first time characterized as invasive by hybridization with the probes.
Comparison of selective media for primary isolation of Aeromonas species from human and animal feces
Authors: Mishra S , Nair G B , Bhadra R K , Sikder S N , Pal S C
Published: January 2020

Five selective media were evaluated for their effectiveness in the primary isolation of Aeromonas spp. from human patients with acute diarrhea and from healthy domestic animals. Sheep blood agar with 30 mg of ampicillin per liter (ASBA30) yielded a significantly higher percentage of positive specimens as compared with the four other media. The effective combination of two selective media with which 98% of all isolates were detected and with which all of the three human-associated Aeromonas spp. could be isolated was ASBA30-DNase-toluidine blue agar. ASBA30 was the most sensitive medium since it permitted more growth of Aeromonas colonies and effectively suppressed competing microflora. We recommend the use of ASBA30-DNase-toluidine blue agar for investigations in which an attempt is made to assess the significance of Aeromonas spp. in the etiology of human diarrhea.
Colony formation and morphology in Borrelia burgdorferi
Authors: Kurtti T J , Munderloh U G , Johnson R C , Ahlstrand G G
Published: January 2020

Two strains of Borrelia burgdorferi, B31 and 297, formed colonies when plated onto Barbour-Stoenner-Kelly medium solidified with agarose (1.3%) and incubated in a candle jar at 34 degrees C. Colonies differing in morphology were observed in both strains after 2 to 3 weeks of incubation. Strain B31 colonies were either compact, round (mean diameter, 0.43 mm), and restricted to the surface of the agarose medium or diffuse (mean diameter, 1.80 mm) and penetrating into the solid medium. Strain 297 colonies (mean diameter, 1.43 mm) either showed a raised center surrounded by a diffuse ring of spirochetes or consisted of numerous small spirochetal aggregates. Both colony types expanded into the agarose medium. Scanning electron and light microscopy confirmed that the colonies were formed by spirochetes. Twisted tangles of intertwined spirochetes were visible on the surface, with numerous spherical bodies among them, especially in the central regions. At the periphery, the borreliae were more loosely packed, and individual coils were discernible.
SIGNAL blood culture system for detection of bacteremia in neonates
Authors: Trombley C , Anderson J D
Published: January 2020

In the SIGNAL (Oxoid Ltd., Basingstoke, United Kingdom) blood culture system, gas produced by bacterial metabolism displaces medium from the culture bottle into an upper reservoir via a hollow needle. Displacement of media may provide a visual indication of the presence of both aerobic and anaerobic organisms in a single medium. The single-bottle SIGNAL system was compared with paired BACTEC 16B and 7D (Johnston Laboratories, Inc., Towson, Md.) radiometric system bottles by using bacterial inocula and conditions which simulated those found in neonatal and pediatric populations. The single SIGNAL bottle was a good as the combined BACTEC media for Escherichia coli and Staphylococcus aureus, but was slower for Candida spp., Haemophilus influenzae, Pseudomonas aeruginosa, Staphylococcus epidermidis, group B streptococci, alpha-streptococci, and pneumococci. The SIGNAL system failed to detect four of five isolates of Neisseria meningitidis and four of eight anaerobic organisms. The SIGNAL system is not suitable for neonatal blood cultures at its present state of development.
Isolation and antigenic reactivity of Brucella ovis outer membrane proteins
Authors: Afzal M , Brodie S J , Tengerdy R P , Squire P G
Published: January 2020

Brucella ovis cell membranes were isolated from fractured and lysozyme-treated cells by ultracentrifugation. These preparations appeared to consist largely of outer membranes, as judged from the results of ultracentrifugation experiments in sucrose density gradients under conditions that are widely used to separate inner and outer membranes of gram-negative bacteria. The sequential detergent extraction of cell membranes yielded mainly lipopolysaccharide and three groups of outer membrane proteins. In immunoblotting, lipopolysaccharide had good antigenic reactivity with all sera from rams exposed to B. ovis (vaccination or natural infection), but some outer membrane proteins reacted strongly only with sera from immune (vaccinated) rams, not from infected rams, suggesting a possible diagnostic role for such proteins in predicting immunity or infection.
Murine monoclonal antibody specific for lipopolysaccharide of Salmonella serogroup A
Authors: Luk M C , Tsang R S , Ng M H
Published: January 2020

To facilitate the routine identification of salmonellae and detailed studies of their lipopolysaccharides, we raised murine monoclonal antibodies against these organisms. We raised an immunoglobulin G1 antibody, MO2, which is specific for factor O2. By immunoblotting following sodium dodecyl sulfate-polyacrylamide gel electrophoresis, MO2 was shown to bind only the lipopolysaccharide of Salmonella paratyphi A, giving a ladderlike reaction pattern with regularly spaced reactive bands. MO2 did not react against lipopolysaccharides of other Salmonella serogroups, including those of serogroups B, C, D, E, and L. Since the lipopolysaccharides of Salmonella serogroups A, B, D, and E are similar except for the presence of paratose in serogroup A organisms, this dideoxyhexose is therefore believed to be the immunodominant epitope for MO2. Consistent with the latter contention was the finding that periodate oxidation of the S. paratyphi A lipopolysaccharide did not destroy its antigenicity for MO2. In a slide agglutination test, MO2 was found to react specifically against all 12 clinical isolates of S. paratyphi A but not against 98 isolates of other salmonellae or 74 isolates of other bacteria and Candida albicans.
Antigenic relationship between the animal and human pathogen Pythium insidiosum and nonpathogenic Pythium species
Authors: Mendoza L , Kaufman L , Standard P
Published: January 2020

Identification of the newly named pathogenic oomycete Pythium insidiosum and its differentiation from other Pythium species by morphologic criteria alone can be difficult and time-consuming. Antigenic analysis by fluorescent-antibody and immunodiffusion precipitin techniques demonstrated that the P. insidiosum isolates that cause pythiosis in dogs, horses, and humans are identical and that they were distinguishable from other Pythium species by these means. The immunologic data agreed with the morphologic data. This indicated that the animal and human isolates belonged to a single species, P. insidiosum. Fluorescent-antibody and immunodiffusion reagents were developed for the specific identification of P. insidiosum.
Restriction endonuclease analysis of nosocomial isolates of Clostridium difficile
Authors: Devlin H R , Au W , Foux L , Bradbury W C
Published: January 2020

A total of 110 clinical isolates of Clostridium difficile were analyzed by agarose gel electrophoresis by using both bacterial restriction endonuclease analysis (REA) and plasmid profiles. A total of 72 isolates were divided into 12 groups according to their REA patterns. Some 38 isolates exhibited unique patterns. Pattern A occurred in 20% of isolates. Isolates with patterns B, E, and G were cytotoxin negative. The remaining groups were cytotoxin positive. Multiple isolates obtained from two stool specimens were studied to examine the variation in REA profiles found in single specimens. In these specimens no variation in REA profiles was found. The stability of C. difficile was studied by examining sequential in vitro subcultures of a single isolate and strains isolated over a 4-month period from two long-term carriers. REA patterns were stable over time, both in vitro and in vivo. Because plasmid DNA was observed in 53% of isolates, plasmid profiles alone could not be used to study the spread of C. difficile; however, they were necessary for the interpretation of REA patterns in some instances.
Collaborative investigation of the accuracy and reproducibility of Sceptor Breakpoint susceptibility panels
Authors: Denys G A , Hansen S L , Pope W A , Lilli H , Hejna J M
Published: January 2020

A combination Sceptor Breakpoint/ID panel (Johnston Laboratories, Inc., Towson, Md.), which determines interpretive susceptibility results (susceptible, moderately susceptible, and resistant) using two to three selected concentrations of antimicrobial agents, was tested in comparison with full-range Sceptor microdilution MIC panels. The inter- and intralaboratory interpretive reproducibilities for 24 control strains tested in three laboratories on three consecutive days were 97.0 and 95.7%, respectively. The equivalency of breakpoint results to category results obtained by the microdilution MIC procedure for 10,368 control organism-antimicrobial agent comparisons was 94.1%. The level of interpretive agreement between breakpoint and MIC category results using 101 fresh clinical isolates was 97.0% for 51 gram-negative and 50 gram-positive bacteria. Among the total 4,872 clinical organism-antimicrobial agent comparisons, major and very major discrepancies were seen in 0.2% of gram-negative bacteria and very major discrepancies were seen in 0.9% of gram-positive bacteria. All very major discrepancies with gram-positive organisms were associated with trailing endpoints using trimethoprim or sulfisoxazole and staphylococci. The breakpoint concept of testing selective antimicrobial agent concentrations was highly reproducible and accurate and allows for placement of more antimicrobial agents into a panel than is possible with full-dilution MIC testing.
Dot immunoperoxidase assay using monoclonal antibody for direct detection of cytomegalovirus in urine samples
Authors: Zerbini M , Musiani M , Gentilomi G , La Placa M
Published: January 2020

A rapid, simple dot immunoperoxidase assay for the direct detection of cytomegalovirus in clinical urine samples was developed. The assay was performed on nitrocellulose paper dotted with urine pellets free of cellular debris. Cytomegalovirus was detected with a monoclonal antibody to the capsid antigen, and the complex was visualized by immunoperoxidase staining. Positive reactions appeared as well-defined dark blue spots. Of the 87 urine samples examined, 10 proved positive in the dot immunoperoxidase assay, and 77 proved negative. The results agreed completely with the detection of cytomegalovirus-induced antigens in cell cultures inoculated with clinical specimens.
Disk diffusion susceptibility testing and broth microdilution quality control guidelines for BMY-28100, a new orally administered cephalosporin
Authors: Jones R N , Barry A L
Published: January 2020

The BMY-28100 30-micrograms-disk test was evaluated by using 615 clinical isolates. Regression analyses and error rates were determined, leading to the recommendation of greater than or equal to 18-mm zone diameters (MIC correlate, greater than or equal to 8.0 micrograms/ml) for susceptibility and less than or equal to 14-mm zone diameters (MIC correlate, greater than or equal to 32 micrograms/ml) for resistance. Nearly all false-susceptible disk test results were among the Providencia spp. and the beta-lactamase-positive Haemophilus influenzae strains. Susceptibility disk test results for these species should be interpreted with caution. The following broth microdilution MIC quality control guidelines were determined from results of a multilaboratory trial: Escherichia coli ATCC 25922, 1.0 to 4.0 micrograms/ml; Enterococcus faecalis ATCC 29212, 4.0 to 16 micrograms/ml; Staphylococcus aureus ATCC 29213, 0.25 to 1.0 microgram/ml; and Pseudomonas aeruginosa ATCC 27853, greater than 32 micrograms/ml.
Peritonsillar abscess caused by Nocardia asteroides
Authors: Adair J C , Amber I J , Johnston J M
Published: January 2020

A 22-year-old man with recurrent pharyngitis developed a peritonsillar abscess from which aspirated material yielded a pure culture of Nocardia asteroides. It is likely that the organism was introduced iatrogenically during a prior tonsillar incision. Although unusual, Nocardia species should be considered and microbiological specimens should be handled appropriately in pharyngeal abscesses that respond poorly to conventional therapy.
Urease-positive bacteriuria and obstruction of long-term urinary catheters
Authors: Mobley H L , Warren J W
Published: January 2020

Long-term urethral catheterization (greater than or equal to 30 days), a management technique for urinary incontinence, results in polymicrobial bacteriuria. We frequently found urease-producing bacteria: of 1,135 weekly urine specimens from 32 long-term-catheterized patients, 86% had urease-positive bacterial species at greater than or equal to 10(5) CFU/ml. The most common species were Proteus mirabilis and Morganella morganii, each found in over half the specimens. P. mirabilis, but not other urease-positive species, was significantly associated with the 67 obstructions observed in 23 patients. M. morganii had a more complex association and in some way may protect the catheter from obstruction.
Evaluation of a quantitative fluorescence immunoassay (FIAX) for detection of serum antibody to Borrelia burgdorferi
Authors: Pennell D R , Wand P J , Schell R F
Published: January 2020

A quantitative, indirect, fluorescence immunoassay (FIAX; Whittaker Bioproducts, Inc.) was compared with the conventional indirect fluorescent-antibody test for detection of serum antibody to Borrelia burgdorferi. FIAX correlated well with the indirect fluorescent-antibody test (r = 0.72). FIAX is a convenient and dependable means of measuring serum antibody to B. burgdorferi.
Comparison of conventional and revised isolator blood culture tubes
Authors: Basille B A , Easley K A , Hall G S , Washington J A
Published: January 2020

A paired clinical study compared bacterial and fungal recovery from 4,553 blood cultures processed by the conventional Isolator (Du Pont Co.) and a revised Isolator consisting of a single-stoppered, round-bottom tube containing the same ingredients as the conventional tube except for an inert fluorochemical. Excluding contaminants, there were 425 positive blood cultures with 450 isolates representing 208 patients. There were no statistically significant differences between systems in the number of positive cultures or patients with positive cultures for each organism group studied, nor were there any statistically significant differences between systems in the time required for detection of positive cultures.
Rapid identification of pathogenic Neisseria species and Branhamella catarrhalis
Authors: Hughes B , Pezzlo M T , de la Maza L M , Peterson E M
Published: January 2020

Two systems, the Identicult-Neisseria (IDN; Scott Laboratories, Inc., Fiskeville, R.I.) strip and the Neisseria/Haemophilus Identification Test Kit (NHI; Vitek Systems, Inc., Hazelwood, Mo.) card, were compared with the 4-h Minitek system (BBL Microbiology Systems, Cockeysville, Md.) for their ability to rapidly identify 157 pathogenic Neisseria and Branhamella catarrhalis isolates. IDN, limited in its identification to four species, when incubated at 35 degrees C for 10 min identified 99% of the isolates. However, when IDN was incubated at 22 degrees C for 20 min, it identified only 92% of the isolates. The NHI card, a rapid semiautomated system with the ability to identify 25 organisms to the species level, correctly identified all of the isolates. A test for beta-lactamase production included in the NHI card identified the 12 Neisseria gonorrhoeae and 10 B. catarrhalis beta-lactamase-positive isolates included in the study. The IDN strip (35 degrees C) and the NHI card compared favorably with the Minitek system.
Evaluation of a commercial monoclonal antibody for detection of adenovirus antigen
Authors: August M J , Warford A L
Published: January 2020

The Adenoclone monoclonal antibody for detection of adenovirus antigen was evaluated by enzyme immunoassay and a 72-h indirect fluorescent-antibody test in shell vials and compared with standard culture. The sensitivity and specificity of the Adenoclone test were both 100% with 114 cell culture isolates. With 310 direct clinical specimens, the Adenoclone enzyme immunoassay sensitivity varied from 14.3 to 66.6%, but the Adenoclone indirect fluorescent-antibody test sensitivity was 86.7%, with 100% specificity.
Serum albumin treatment to eliminate false-positive results with laboratory rodent specimens tested by rotazyme enzyme-linked immunosorbent assay
Authors: Jure M N , Morse S S , Stark D M
Published: January 2020

A high proportion of positive results was found in fecal specimens from mice and rats tested by Rotazyme II enzyme-linked immunosorbent assay, but the presence of virus could not be confirmed. Positive specimens and nonautoclaved rodent diet contained a substance that apparently attached nonspecifically to the antibody-coated beads used in the test and reacted directly with the substrate. Pretreatment of the beads with 0.1% bovine serum albumin eliminated this nonspecific activity.
Susceptibility testing of carumonam: interpretive criteria for 30-microgram disk tests and quality control guidelines for disk diffusion and broth microdilution methods
Authors: Jones R N , Barry A L
Published: January 2020

Carumonam 30-microgram disk diffusion tests with 342 gram-negative organisms suggested modifying earlier interpretive zone criteria, i.e., a susceptibility zone diameter of greater than or equal to 23 mm (less than or equal to 8.0 micrograms/ml MIC correlate) and a resistance zone diameter of less than or equal to 17 mm (greater than or equal to 32 micrograms/ml MIC correlate). Quality assurance guidelines were determined by multilaboratory investigations. Recommended limits were calculated for the gram-negative quality control organisms only. For Escherichia coli ATCC 25922, the recommended limits are 30 to 36 mm and 0.03 to 0.25 micrograms/ml, and for Pseudomonas aeruginosa ATCC 27853, they are 24 to 32 mm and 1.0 to 4.0 micrograms/ml.
Listeria monocytogenes ATCC 35152 and NCTC 7973 contain a nonhemolytic, nonvirulent variant
Authors: Pine L , Weaver R E , Carlone G M , Pienta P A , Rocourt J , Goebel W , Kathariou S , Bibb W F , Malcolm G B
Published: January 2020

Listeria monocytogenes NCTC 7973 and this same strain deposited as ATCC 35152 contain two phenotypes: hemolytic virulent colonies and nonvirulent colonies that show no zones of hemolysis when streaked on heart infusion agar containing 5% rabbit blood. Results of examinations of these virulent and nonvirulent strains by investigators at the Centers for Disease Control, Atlanta, Ga., the Pasteur Institute, Paris, France, and the University of Würzburg, Federal Republic of Germany, support the conclusion that the avirulent strain is a nonhemolytic mutant of the virulent strain and that hemolysin is a virulence factor for L. monocytogenes.
Specificity of a Mycobacterium kansasii phenolic glycolipid (mycoside A) immunoserum
Authors: Papa F , Riviere M , Fournié J J , Puzo G , David H
Published: January 2020

The specificity of Mycobacterium kansasii anti-mycoside A antiserum prepared in rabbits injected with purified samples of the phenolic glycolipid was evaluated by an enzyme-linked immunosorbent assay. Chloroform-methanol extracts from representative strains of 23 mycobacterial species and 50 strains of M. kansasii showed that all strains of M. kansasii and the representative strain of M. gastri formed the antigen, whereas none of the remaining species (including M. leprae) formed it. Consequently, it was found that the antiserum was highly specific and useful for diagnostic purposes.
Identification of a common immunodominant protein in culture filtrates of three Nocardia species and use in etiologic diagnosis of mycetoma
Authors: Angeles A M , Sugar A M
Published: January 2020

Diagnosis of systemic nocardiosis has been hampered by difficulty in the rapid isolation and identification of the organism and by the frequent need for invasive biopsies. We show that a 55,000-Mr protein previously found in Nocardia asteroides is also present in N. brasiliensis and N. caviae culture filtrates. We also used the antigen in a dot blot assay to identify patients infected with N. brasiliensis. Sera from patients with mycetoma secondary to N. brasiliensis (n = 6) or Actinomadura madurae (n = 2) and 10 hospitalized controls were tested. Six (100%) of the sera from the patients with nocardial mycetoma had positive dot blots to purified antigen, whereas all 10 of the control sera were negative. Serum from one of two patients infected with A. madurae also reacted with the antigen. Thus, the 55-kilodalton protein appears to be produced by three medically important species of Nocardia and is useful when used in an immunoblot assay for identifying patients infected with these organisms.
Examination of feces and serum for diagnosis of infant botulism in 336 patients
Authors: Hatheway C L , McCroskey L M
Published: January 2020

In the 12-year period 1975 to 1987, feces from 336 infants were examined for botulinal neurotoxin and Clostridium botulinum. All the infants had illnesses which prompted their physicians to consider infant botulism in the diagnosis. Stool specimens from 113 of the infants yielded organisms that produced botulinal neurotoxins assumed to be responsible for the illness. The types of botulinal toxin in the confirmed cases were distributed as follows: 38 A, 69 B, 2 atypical B, 1 E, 1 F, 1 A + B, and 1 B + F. The type A and B toxins in a single infant were produced by two different strains of organism, and the type B and F toxins in another infant were produced by a single strain. The physiological characteristics of all the isolated toxigenic organisms except two were consistent with those of group I (proteolytic) C. botulinum. The toxigenic isolate from the infant with type E botulism was identified as C. butyricum, and that from the infant with type F botulism was identified as C. barati. Toxin of the same type as produced by the isolated organisms was identified in feces of 98 of 111 culture-positive infants. Botulinal toxin was identified in the serum of 9 of 67 culture-positive infants (8 of 22 infants with type A organisms; 1 of 43 infants with type B organisms; neither of 2 infants with A + B or atypical type B organisms). Botulinal toxin was not detected in feces (206 infants) or in serum (114 infants) of the culture-negative infants. The culture-positive infants had clinical features and a course of illness consistent with those of infant botulism. Most of the culture-negative infants probably had illnesses other than botulism, but specimens might have been obtained late in some infants' illnesses, when the organism had disappeared.
Evaluation of new commercial enzyme immunoassay for rotavirus detection
Authors: Cromien J L , Himmelreich C A , Glass R I , Storch G A
Published: January 2020

We evaluated a new commercial enzyme immunoassay (EIA) for rotavirus (Rotavirus EIA; International Diagnostic Laboratories, Chesterfield, Mo.). A total of 161 consecutive stool samples (including 18 from infants less than 30 days old) submitted to the diagnostic laboratory at Children's Hospital, Washington University Medical Center, St. Louis, Mo., for rotavirus detection were tested by Rotavirus EIA and by Rotazyme II (Abbott Laboratories, North Chicago, III.) according to the instructions of the manufacturer. In addition, 16 samples from infants less than 30 days old without diarrhea were tested by both assays. Samples showing discrepant results after repeat testing were examined by electron microscopy. Nine samples yielding discrepant results were also tested by using a reference EIA directly on the specimen and on culture supernatants from two passages in MA 104 cells. Rotavirus EIA and Rotazyme II yielded concordant results for 85% of the samples. All of the 26 discrepant samples tested negative by Rotavirus EIA and positive (15 samples) or equivocal (11 samples) by Rotazyme II. These samples included 11 from symptomatic infants more than 30 days old, 2 from symptomatic infants less than 30 days old (neonates), and 2 from neonates without diarrhea. Rotavirus was not detected in any of the 24 that were examined by electron microscopy or in any of the 9 that were tested by the reference EIA. The sensitivity, specificity, positive predictive value, and negative predictive value were 100% for Rotazyme EIA and 100, 90, 70, and 100%, respectively, for Rotazyme II. Rotavirus EIA was comparable to Rotazyme II in ease of performance. We conclude that Rotavirus EIA is equally sensitive and more specific than Rotazyme II for detecting rotavirus. Rotavirus EIA is a practical and accurate rotavirus assay for use in clinical laboratories.
Laboratory indices of clinical peritonitis: total leukocyte count, microscopy, and microbiologic culture of peritoneal dialysis effluent
Authors: Males B M , Walshe J J , Amsterdam D
Published: January 2020

Total leukocyte count, microscopy, and conventional bacteriologic culture (10-ml sediment) of dialysis effluent were assessed for their ability to detect peritonitis in patients on peritoneal dialysis. A total of 73 patients were surveyed over a 17-month period. Laboratory findings included an examination of 1,774 dialysate samples and culture results from blood, wounds, indwelling catheters, and other specimens. Of 90 peritonitis events, 72 were culture positive. Gram-stained films were positive in no more than 14% of the dialysates collected during periods of clinical peritonitis. Factors which adversely affected the microscopic or cultural detection of microorganisms in effluent included the concentration of organisms in dialysate, antibiotic therapy, and growth medium used. Seeding of the peritoneum with organisms originating from other sites of infection or colonization was documented, although infrequent, yet bacteremia secondary to peritonitis was not seen. Because of the frequent isolation of microorganisms from dialysates in the absence of clinical peritonitis, culture-positive findings were a poor predictor of peritonitis without other evidence of infection. Detection of peritonitis by total leukocyte count (without a differential count) of dialysate specimens was adversely affected by the overlap in cell counts between dialysates collected either during or in the absence of peritonitis. This was attributed in part to nonspecific increases in dialysate cell count in the absence of peritonitis and was associated with intermittent dialysis and extraperitoneal infection.
Indicator medium for isolation of Campylobacter pylori
Authors: Queiroz D M , Mendes E N , Rocha G A
Published: January 2020

The use of a new indicator culture medium, Belo Horizonte medium, is proposed for better colony recognition and a presumptive identification of Campylobacter pylori. This medium, containing brain heart infusion sheep blood agar, was supplemented with 40 mg of 2,3,5-triphenyltetrazolium chloride per liter in addition to vancomycin, nalidixic acid, and amphotericin B. On Belo Horizonte medium, Campylobacter pylori present unique golden colonies.
Fluorescent monoclonal antibody for confirmation of Neisseria gonorrhoeae cultures
Authors: Laughon B E , Ehret J M , Tanino T T , Van der Pol B , Handsfield H H , Jones R B , Judson F N , Hook E W
Published: January 2020

We evaluated a monoclonal fluorescent-antibody (FA) reagent (Neisseria gonorrhoeae Culture Confirmation Test; Syva Co., Palo Alto, Calif.) for confirmation of N. gonorrhoeae isolates obtained from clinics for sexually transmitted diseases in four cities. The FA test was performed in parallel with established confirmation procedures on all organisms growing on 773 primary culture plates of modified Thayer-Martin agar. All N. gonorrhoeae isolates reacted with the FA reagent and produced a bright, easily interpretable fluorescence. The FA test correctly identified 533 N. gonorrhoeae isolates from 474 patients and did not react with 90 N. meningitidis or with 213 non-Neisseria isolates. In one city (Baltimore), Gonochek II (Du Pont Co., Wilmington, Del.) failed to identify four N. gonorrhoeae isolates reactive with the FA reagent and confirmed as N. gonorrhoeae by Phadebact (Pharmacia Inc., Piscataway, N.J.) and acid production from sugars. The FA test was rapid and specific and could be performed directly from primary isolation plates. The test requires 1 h to perform and is applicable to mixed-flora cultures.
Evaluation of latex-based heterophile antibody assay for diagnosis of acute infectious mononucleosis
Authors: Cook L , Midgett J , Willis D , Clinton B , Folds J D
Published: January 2020

The diagnosis of an acute episode of infectious mononucleosis (IM) is made on the basis of clinical symptoms and serological evidence for development of heterophile antibodies. In an effort to obtain a very sensitive and specific assay for diagnosis of IM, we have developed MERISTAR:IM. The MERISTAR assay uses latex beads coated with purified bovine heterophile antigen. We compared the sensitivity and specificity and performance characteristics of the latex-based test to those of the commercially available erythrocyte-based Monospot test with serum samples from 363 suspected-IM patients and controls. A total of 28 samples from patients with confirmed IM were positive with the MERISTAR assay, while only 23 of the samples were positive with the Monospot assay. The two assays had equal specificity, as each test gave two false-positive results. In the technical performance of the assay, the MERISTAR assay was simpler and faster to perform than the Monospot assay.
Improved procedures for differentiating Microsporum persicolor from Trichophyton mentagrophytes
Authors: Kane J , Sigler L , Summerbell R C
Published: January 2020

Microsporum persicolor, a zoophilic dermatophyte species, is seldom recorded causing human infections in North America. Its identification has been enhanced as a direct result of the development of improved techniques for its characterization. Identifying characteristics include induction of rough-walled macroconidia on sodium chloride-amended medium, absence of good growth at 37 degrees C, and absence of a pH change during growth on casein glucose medium. In contrast, Trichophyton mentagrophytes, a species commonly confused with M. persicolor, has smooth-walled macroconidia, grows well at 37 degrees C, and produces an alkaline reaction on casein glucose medium.
Characterization of hemolysin in extracellular products of Pseudomonas cepacia
Authors: Nakazawa T , Yamada Y , Ishibashi M
Published: January 2020

Pseudomonas cepacia is recognized as an opportunistic pathogen in immunocompromised patients. We screened 120 strains of P. cepacia isolated from clinical specimens for production of extracellular products. About 70% of these strains produced lipase, protease, and lecithinase, but only 4% produced hemolysin. A hemolysin produced by P. cepacia JN106 was characterized. The hemolysin was most active against human erythrocytes. Horse, sheep, chicken, and rabbit erythrocytes were also susceptible. The hemolysin was heat labile and was inhibited by sterols but was not activated by 2-mercaptoethanol and dithiothreitol. Four hemolysin-negative mutants obtained by N-methyl-N'-nitro-N-nitrosoguanidine treatment produced the other extracellular products. A 58-kilobase-pair plasmid found in the parent strain was also found in the mutant strains, suggesting that the hemolysin gene resides on the chromosome.
Bacterial concentration correlations in experimental endocarditis caused by Staphylococcus epidermidis
Authors: Baddour L M , Christensen G D , Bisno A L
Published: January 2020

Using 13 strains of Staphylococcus epidermidis to produce catheter-induced experimental endocarditis in rats, we found that bacterial concentrations in blood cultures obtained at the time of sacrifice correlated significantly with the number of organisms per gram of endocardial vegetation (P less than 0.001) and the total number of organisms per vegetation (P less than 0.001). Furthermore, blood culture concentrations correlated with vegetation weights (P less than 0.001) and sizes of infecting inocula (P less than 0.0001). Mean bacterial concentrations in vegetations more than doubled as bacterial concentrations in blood rose from less than 10 to greater than 100 CFU/ml. Mean values for vegetation weights, total organisms per vegetation, and sizes of infecting inocula were also reflected by the intensity of bacteremia. Moreover, intracardiac catheters were more likely colonized as bacterial concentrations in blood cultures increased, with all catheters culture positive in the 25 animals that exhibited high-grade bacteremia (greater than or equal to 100 CFU/ml). Slime production by the bacteria did not influence the above-mentioned correlations. These data indicate that the blood concentration of bacteria reflects the microbiologic status of infected vegetations in experimental infective endocarditis.
Diaper area skin microflora of normal children and children with atopic dermatitis
Authors: Keswick B H , Seymour J L , Milligan M C
Published: January 2020

In vitro studies established that neither cloth nor disposable diapers demonstrably contributed to the growth of Escherichia coli, Proteus vulgaris, Staphylococcus aureus, or Candida albicans when urine was present as a growth medium. In a clinical study of 166 children, the microbial skin flora of children with atopic dermatitis was compared with the flora of children with normal skin to determine the influence of diaper type. No biologically significant differences were detected between groups wearing disposable or cloth diapers in terms of frequency of isolation or log mean recovery of selected skin flora. Repeated isolation of S. aureus correlated with atopic dermatitis. The log mean recovery of S. aureus was higher in the atopic groups. The effects of each diaper type on skin microflora were equivalent in the normal and atopic populations.
Detection of Streptococcus pneumoniae and Haemophilus influenzae type b antigens in acute nonbacteremic pneumonia
Authors: Martin S J , Hoganson D A , Thomas E T
Published: January 2020

Commercially available latex agglutination and coagglutination reagents were evaluated for their ability to detect bacterial antigens in the sera of 165 patients to determine their suitability for rapid diagnosis of pneumonia. These reagents were used to detect the polysaccharide capsular antigens of Haemophilus influenzae type b and Streptococcus pneumoniae in nonbacteremic patients known to be respiratory culture positive for these organisms. The reagents were unable to detect the polysaccharide antigens in sera from nonbacteremic patients. Patients with a clinical diagnosis of pneumonia who had respiratory or extrarespiratory infections with a variety of organisms were also tested. No evidence of cross-reactivity or of false-positive reactions was observed with either reagent. Because a negative agglutination test may occur during the course of a nonbacteremic infection, these reagents should not be used alone, and if used, they should be used only in conjunction with standard bacteriological tests.
Utilization of nitrate or nitrite as single nitrogen source by Mycobacterium avium
Authors: McCarthy C M
Published: January 2020

Twenty L-amino acids and several inorganic compounds were tested individually, as a sole nitrogen source, for ability to support the growth of Mycobacterium avium LM1 serovar 1. Of the amino acids tested, only L-glutamine provided nutritional support comparable to that of ammonium chloride at 1 mM. With either 1 mM potassium nitrate or nitrite substituted for ammonium chloride, similar numbers of CFU were produced. M. avium cells were grown in potassium nitrate or nitrite concentrations of 0.25, 0.5, 1.0, and 2.0 mM, and the medium was assayed for remaining nitrogen compound at several times during growth. Rates of utilization were of first-order kinetics, with nitrite removed more rapidly than nitrate. The rates were approximately 10 times as rapid at 0.25 mM than at 2 mM for either nitrogen source. Nine clinical isolates that included M. avium serovars 1, 4, and 8 and Mycobacterium scrofulaceum serovar 43 were tested for rate of utilization of ammonia, nitrate, or nitrite. Ammonia and nitrite were utilized with first-order kinetics by all strains. Nitrate utilization occurred but was not at the same level for all strains. Clinical tests indicate that M. avium is negative for nitrate reductase; this is because of the rapid reduction of nitrite produced from nitrate.
Monoclonal antibody passive hemagglutination and capture enzyme-linked immunosorbent assays for direct detection and quantitation of F41 and K99 fimbrial antigens in enterotoxigenic Escherichia coli
Authors: Raybould T J , Crouch C F , Acres S D
Published: January 2020

Production of diarrhea in neonatal calves by enterotoxigenic Escherichia coli depends on its ability to attach to the epithelial cells of the intestine via surface adhesins called pili or fimbriae and to secrete enterotoxins. The most important of these fimbriae are designated K99 and F41. We produced and characterized a murine monoclonal antibody specific to F41. This monoclonal antibody and a K99-specific monoclonal antibody were used to develop sensitive and specific passive hemagglutination and capture enzyme-linked immunosorbent assays (ELISAs) for detection and quantitation of F41 and K99 antigens in E. coli cultures and culture supernatants. The capture ELISA systems exhibited excellent sensitivity and specificity, whereas the passive hemagglutination systems appeared to be oversensitive. The ability of the capture ELISAs to detect K99 and F41 fimbrial antigens in fecal specimens from calves was evaluated. Fimbrial antigens were detected in six of six specimens from scouring calves but not in four of four specimens from nonscouring calves.
Analysis by plaque reduction neutralization assay of intertypic rotaviruses suggests that gene reassortment occurs in vivo
Authors: Hoshino Y , Sereno M M , Midthun K , Flores J , Chanock R M , Kapikian A Z
Published: January 2020

The SB-1A rotavirus recovered from a diarrheic piglet in the United States is a naturally occurring intertypic rotavirus. When studied by reciprocal neutralization tests, the SB-1A virus was similar, if not identical, to the porcine Gottfried virus (serotype 4) and the porcine OSU virus (serotype 5). Analysis of reassortant viruses prepared from the SB-1A virus and the serotype 2 human DS-1 virus revealed that the antigenic specificity of the outer capsid protein VP3 of SB-1A was shared with the OSU virus, while the antigenic specificity of another outer capsid protein, VP7, of SB-1A appeared to be shared with the Gottfried virus. This suggests that SB-1A is a naturally occurring reassortant rotavirus between OSU-like and Gottfried-like porcine rotaviruses. In addition, using a genetic approach, we found evidence that the fourth gene was responsible for the predominantly one-way cross-neutralizing reactivity between canine rotavirus strain CU-1 (serotype 3) and porcine rotavirus strains SB-1A (serotypes 4 and 5) and OSU (serotype 5). Assignment of hemagglutination function to the fourth genome segment of porcine rotaviruses SB-1A and OSU and canine rotavirus CU-1 confirmed a similar previous gene assignment established for certain rotaviruses. Analysis of single gene 4 substitution reassortants confirmed our previous finding that VP3 was as potent in stimulating neutralizing antibodies as VP7. The observations confirm the need for a binary system of rotavirus classification and nomenclature similar to that used for the influenza A viruses; in such a system the neutralization specificity of both VP3 and VP7 would be indicated.
Analysis by RNA-RNA hybridization assay of intertypic rotaviruses suggests that gene reassortment occurs in vivo
Authors: Midthun K , Valdesuso J , Hoshino Y , Flores J , Kapikian A Z , Chanock R M
Published: January 2020

Antigenic characterization of human and animal rotaviruses by the plaque reduction neutralization assay has shown the existence of naturally occurring intertypes. Antiserum to M37, a rotavirus strain isolated from an asymptomatic neonate, neutralizes both Wa and ST3 strains, which are classified as serotype 1 and serotype 4 human rotaviruses, respectively. Likewise, antiserum to SB-1A, a porcine rotavirus, neutralizes rotavirus strains belonging to serotype 4 or 5. Plaque reduction neutralization assay of reassortant rotaviruses produced in vitro from these intertypes indicates that these viruses share one antigenically related outer capsid protein, VP3, with one serotype and another antigenically related outer capsid protein, VP7, with the other serotype. Thus, M37 is related to ST3 on the basis of its fourth-gene product, VP3, and to Wa on the basis of its ninth-gene product, VP7, whereas SB-1A is related to Gottfried (serotype 4 porcine rotavirus) via VP7 and to OSU (serotype 5 porcine rotavirus) via VP3. RNA-RNA hybridization studies revealed a high degree of homology between the VP3 or VP7 gene segments responsible for shared serotype specificity. Thus, the fourth gene segments of M37 and ST3 were highly homologous, while M37 and Wa had homology between their ninth gene segments. SB-1A and Gottfried were homologous not only with respect to the ninth gene but had complete homology in all other genes except the fourth gene. The fourth gene of SB-1A was highly homologous with the fourth gene of OSU. These observations suggested that SB-1A was a naturally occurring reassortant between Gottfried-like and OSU-like porcine rotavirus strains. Our observations also suggested that intertypes may result from genetic reassortment in nature.