bluuebunny/crossref_metadata_2025 huggingface dataset:
Predictive value of the "clue cells" investigation and the amine volatilization test in vaginal infections caused by Gardnerella vaginalis
Authors: Marquez-Davila G , Martinez-Barreda C E
Published: January 2020

Although still controversial, an etiologic role of Gardnerella vaginalis is imputed in vaginitis. Besides isolation of the organism by culture, two alternative diagnostic procedures have been claimed to be useful: the investigation of "clue cells" in clinical specimens and the amine volatilization test or fishy odor perception in genital secretions. Herein we report on the findings of the simultaneous use of G. vaginalis isolation, the clue cell test and amine volatilization perception in specimens from 1,263 consecutive female patients referred to our clinic. Our results show that the simultaneous use of both alternative tests is very useful as a screening procedure. A negative result of both tests predicts a negative culture result in 99% of the cases. However, a positive result of either or both should be considered as an indication to proceed to culture and not as diagnostic of infection.
Interpretive standards and quality control guidelines for cefpiramide disk susceptibility tests
Authors: Barry A L , Gavan T L , Thornsberry C , Jones R N
Published: January 2020

Disk susceptibility tests with 30- and 75-micrograms cefpiramide disks were evaluated with 614 bacterial isolates. Quality control parameters were also evaluated, and control limits for disk tests are recommended. Tests with 75-micrograms disks are recommended, with zone size standards of greater than or equal to 19 mm for susceptible (MIC, less than or equal to 32 micrograms/ml) and less than or equal to 15 mm for resistant (MIC, greater than or equal to 128 micrograms/ml).
Enterotoxigenic Escherichia coli strains belonging to a new serogroup, Escherichia coli O166
Authors: Gross R J , Thomas L V , Rowe B
Published: January 2020

Thirty-two strains of Escherichia coli belonging to a new O group, O166, were examined. Twenty-one strains had the flagella antigen H27, five had the H15 antigen, five had the H7 antigen, and one was nonmotile. All the H27 strains and the nonmotile strain produced heat-stable enterotoxin but not heat-labile enterotoxin. All the H7 strains produced heat-labile enterotoxin but not heat-stable enterotoxin. The remaining strains were nonenterotoxigenic. None of the strains possessed colonization factor antigens CFA/I, CFA/II, or PCF8775.
Difficulties in differentiating Neisseria cinerea from Neisseria gonorrhoeae in rapid systems used for identifying pathogenic Neisseria species
Authors: Boyce J M , Mitchell E B
Published: January 2020

Neisseria cinerea and Neisseria gonorrhoeae may occur at the same body sites and may have similar colony morphologies. Ideally, systems used for rapid identification of N. gonorrhoeae should be able to differentiate N. cinerea from gonococci. We tested seven N. cinerea strains using the Gonochek II (Du Pont Diagnostics), Minitek (BBL Microbiology Systems), RapID-NH (Innovative Diagnostics, Inc.), RIM-N (American Microscan), and Phadebact (Pharmacia Diagnostics) systems. We found that the reactions produced by N. cinerea in Gonochek II, Minitek, and RapID-NH kits could be confused with the results produced by some strains of N. gonorrhoeae. The susceptibility of N. cinerea to colistin, its ability to grow on tryptic soy or Mueller-Hinton agar, and its inability to grow on modified Thayer-Martin medium help differentiate it from gonococci.
Incidence and characterization of beta-hemolytic Streptococcus milleri and differentiation from S. pyogenes (group A), S. equisimilis (group C), and large-colony group G streptococci
Authors: Lawrence J , Yajko D M , Hadley W K
Published: January 2020

The biochemical characteristics of 172 clinical isolates of group A, C, F, or G or "nongroupable" beta-hemolytic streptococci were examined. Among these isolates, 91 were identified as beta-hemolytic strains of Streptococcus milleri. The remaining isolates included 20 Streptococcus pyogenes, 21 Streptococcus equisimilis, 37 large-colony group G streptococci, and 3 unidentified nongroupable isolates. A majority (84%) of the S. milleri strains possessed Lancefield group antigen (3 A, 27 C, 41 F, and 5 G), whereas 15 S. milleri strains (16%) were nongroupable. Serological tests did not differentiate S. milleri isolates with group A, C, or G antigen from S. pyogenes (group A), S. equisimilis (group C), or large-colony group G streptococci. Biochemical tests which were found useful for differentiation included the Voges-Proskauer test, hydrolysis of pyroglutamic acid and beta-D-glucuronide, bacitracin susceptibility, and acid production from ribose. S. milleri represented 56% of the group C, 100% of the group F, and 83% of the nongroupable beta-hemolytic streptococci isolated in our clinical laboratory, whereas the incidence of S. milleri among group A and group G streptococci was estimated to be low. The role of beta-hemolytic S. milleri as a cause of human infection remains obscured by the failure to routinely differentiate S. milleri from other beta-hemolytic streptococci.
Rapid detection of respiratory syncytial virus in nasopharyngeal secretions by enzyme-linked immunosorbent assay
Authors: Lauer B A , Masters H A , Wren C G , Levin M J
Published: January 2020

A new enzyme-linked immunosorbent assay (ELISA) respiratory syncytial virus antigen detection kit (Ortho Diagnostics, Inc., Raritan, N.J.) was compared with virus culture and with the indirect fluorescent antibody test (FAT) by using fresh nasal washings from children with suspected respiratory syncytial virus infection. Both uncentrifuged nasal washings and pellets from centrifuged split specimens were examined by ELISA. The ELISA was considered positive when the optical density was greater than the mean background optical density plus 0.15. Specimens positive by ELISA but negative by culture and FAT were reexamined in an ELISA blocking assay. Of 337 uncentrifuged specimens, 124 (37%) were positive by culture, 107 (32%) were positive by FAT, and 166 (49%) were positive by ELISA. Blocking assays showed that 21 of 30 (70%) of the seemingly false-positive ELISA tests were, in fact, true-positives and that the cultures and FATs were falsely negative. A patient specimen was considered positive when it was positive by virus culture, FAT, or blocking assay. The sensitivity, specificity, and positive predictive value of the ELISA test were 88, 94, and 95%, respectively. Centrifugation of nasal washings raised the sensitivity from 88 to 92% but reduced the specificity from 94 to 81%. We conclude that the Ortho ELISA test of uncentrifuged nasal washings is more sensitive than virus culture or indirect FAT and is highly specific.
Evaluation of Mycotrim-GU for isolation of Mycoplasma species and Ureaplasma urealyticum
Authors: Wood J C , Lu R M , Peterson E M , de la Maza L M
Published: January 2020

The Mycotrim-GU (Hana Biologics, Berkeley, Calif.) biphasic culture system and a conventional system were compared for their ability to detect Ureaplasma urealyticum and Mycoplasma species in 100 clinical specimens. Both systems detected 18 Mycoplasma spp. isolates. The average colony detection time was 1.9 days with the Mycotrim-GU and 2.3 days with the conventional system. The Mycotrim-GU agar detected all 33 U. urealyticum isolates recovered in the study, and the conventional agar detected 31. In addition to the U. urealyticum isolates recovered from the agar, there were several specimens that, although they did not grow colonies on the agar, gave an alkaline broth change. Of these specimens, two were found with the conventional system and seven were found with the Mycotrim-GU. The average detection time of U. urealyticum colonies was 2.0 days for the conventional agar and 1.7 days for the Mycotrim-GU. The Mycotrim-GU offers several advantages over the conventional system: it is commercially available, consists of a one-flask system which is ready to use, has a significantly longer shelf life, and is cost competitive. This study showed the Mycotrim-GU to be an effective system for detecting the genital mycoplasmas.
Evaluation of the BIOGRAM antimicrobial susceptibility test system
Authors: D'Amato R F , Hochstein L , Vernaleo J R , Cleri D J , Wallman A A , Gradus M S , Thornsberry C
Published: January 2020

BIOGRAM is an antimicrobial susceptibility test system for the determination of MICs from the standard disk diffusion test zone diameters. The system was challenged with 511 recent clinical isolates of members of the family Enterobacteriaceae, nonfermentative gram-negative bacteria, staphylococci, and enterococci. Results were compared with those obtained with the broth microdilution method. Appropriate control organisms were included with each test series. A total of 10,085 organism-drug combinations were evaluated. BIOGRAM demonstrated an overall correlation of 95.9% with the reference broth microdilution method.
Comparison of the Du Pont Isolator 1.5 Microbial Tube and Trypticase soy broth for the recovery of Haemophilus influenzae type b in experimental bacteremia
Authors: Rubin L G , Baranowski J
Published: January 2020

The isolator 1.5 Microbial Tube (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) is a new blood culture system for detection of bacteremia in children which involves lysis of blood cells and direct plating of blood lysate on agar media. Haemophilus influenzae type b is a major pediatric pathogen and may be associated with low-density bacteremia (less than or equal to 50 CFU per ml), yet the clinical data on the efficacy of this system for recovery of H. influenzae b are limited. We used a rat model of H. influenzae b bacteremia and fresh, whole human blood inoculated in vitro with H. influenzae b to compare the 1.5 Microbial Tube and conventional Trypticase soy broth (BBL Microbiology Systems, Cockeysville, Md.) for the detection of low-density H. influenzae b bacteremia. There was a significantly lower recovery of H. influenzae b from blood of bacteremic rats and from in vitro-inoculated human blood by using the 1.5 Microbial Tube than by using Trypticase soy broth. Studies on the mechanism of this lower recovery suggested that the contents of the 1.5 Microbial Tube are toxic to H. influenzae b in the presence of human blood. Additional clinical data are necessary before the 1.5 Microbial Tube can be recommended for detection of low-density H. influenzae b bacteremia.
Encapsulation and capsular types in isolates of Staphylococcus aureus from different sources and relationship to phage types
Authors: Sompolinsky D , Samra Z , Karakawa W W , Vann W F , Schneerson R , Malik Z
Published: January 2020

The relationship of capsular types of Staphylococcus aureus to type of infection, carrier state, and phage type was studied in a collection of 477 isolates from 380 infection sites. Capsular polysaccharides were demonstrated by precipitation and agglutination with 11 monospecific antisera. When only one isolate from each infection was considered, 63% were of type 8 and 16% were of type 5. Of all the isolates tested, over 90% were encapsulated. We did not demonstrate any marked difference in the distribution of capsular types between isolates from the blood stream or purulent processes and isolates from healthy carriers or food. Most isolates from bovine mastitis milk had nontypeable capsules. The capsular type seemed stable in culture, and encapsulation had no apparent influence on susceptibility to phages. Of 27 phage-propagating strains maintained via culture transfer on artificial media over many years, 16 (59%) produced capsules. A striking association between certain phage patterns and capsular types was demonstrated.
Inoculum size and lot-to-lot variation as significant variables in the tube coagulase test for Staphylococcus aureus
Authors: Selepak S T , Witebsky F G
Published: January 2020

For a positive coagulase test with certain isolates of Staphylococcus aureus, inoculation of 0.5 ml of coagulase plasma with at least two colonies and 24 h of incubation at 35 to 37 degrees C may be required. S. aureus does not multiply in coagulase plasma. There is also lot-to-lot variation in the sensitivity of coagulase plasma. On isolates from critical specimens, a negative coagulase test obtained with an inoculum of less than two colonies should be confirmed by repeating the procedure with a larger inoculum or by using some other confirmatory test.
Enteropathogenic Escherichia coli diarrhea in hospitalized children in Bangladesh
Authors: Moyenuddin M , Rahman K M
Published: January 2020

The role of enteropathogenic Escherichia coli (EPEC) was evaluated in a group of children with endemic diarrhea admitted to Dhaka Shishu Hospital in Dacca, Bangladesh. EPEC was detected in fecal samples of 23% of 104 cases and 8% of 74 concurrent control children. The most commonly isolated EPEC strains were serogroups O20a, O20c:K61; O20a, O20b:K84; O26:K60; and O18a, O18c:K77. Except for O26:K60, these groups had not been reported from Bangladesh. On testing for enterotoxin production, only two strains (serogroups O26:K60, O18a, and O18c:K77) were enterotoxigenic. None was enteroinvasive as tested in the guinea pig conjunctivitis model. Our study supports the concept that EPEC may be an important cause of endemic diarrhea in Bangladesh.
Rapid diagnosis of rotavirus gastroenteritis by a commercial latex agglutination test
Authors: Pai C H , Shahrabadi M S , Ince B
Published: January 2020

The Rotalex test, a commercial latex agglutination test for rotavirus, was compared with direct electron microscopy (EM) and the Rotazyme test I, a commercial enzyme immunoassay, for detection of rotavirus in stools of children and neonates. For initial stool specimens from 265 children (less than 3 years old) with diarrhea, the Rotalex test had a sensitivity of 81.7% and specificity of 99.5% compared with EM results. Positive and negative predictive values were 98 and 94.9%, respectively. The Rotalex test was slightly more sensitive and specific than the Rotazyme test. When daily stool specimens from patients with rotavirus gastroenteritis were examined, the sensitivity of the Rotalex test varied depending on the time of stool collection relative to the onset of symptoms. Sensitivity was 100 (20/20), 96 (23/24), and 54% (7/13) during 1 to 4, 5 to 7, and 8 to 18 days, respectively, after the onset of symptoms. The sensitivity of the Rotazyme test varied similarly with days from onset. We also examined 214 EM-negative stool specimens from asymptomatic newborns. False positivity by the Rotalex test was only 3.3% (7/214) compared with 4.2% (9/215) for the Rotazyme test. The Rotalex test was as sensitive and specific as EM for detection of rotavirus during the acute stage of illness and much faster and cheaper than EM or the Rotazyme test. The test appears to be suitable for routine use in small hospitals, emergency wards, or even the physician's office for rapid diagnosis of rotavirus gastroenteritis.
Cephalothin susceptibility as a potential marker for the Aeromonas sobria group
Authors: Janda J M , Motyl M R
Published: January 2020

Fifty-four motile Aeromonas strains, composing the three currently recognizable species, were tested for susceptibility to cephalothin by broth dilution and disk agar diffusion assays. Cephalothin susceptibility was significantly associated with Aeromonas sobria (P less than 0.001) and may be an additional phenotypic marker useful in the identification of this species.
Frequency of Chlamydia trachomatis as the cause of pharyngitis
Authors: Huss H , Jungkind D , Amadio P , Rubenfeld I
Published: January 2020

We evaluated the incidence of Chlamydia trachomatis as the etiologic agent of uncomplicated pharyngitis by the cell culture procedure recommended by the Centers for Disease Control, Atlanta, Ga., and by the MicroTrak direct immunofluorescent stain (Syva Co., Palo Alto, Calif.) for elementary bodies on throat swabs collected from 126 symptomatic patients. Of the 126 cultures, 8% were positive for group A beta-hemolytic streptococci. Of 126 chlamydia cultures, none was positive. The MicroTrak test gave one borderline positive result. In contrast to a previously published report that C. trachomatis is the most frequent nonviral cause of adult pharyngitis (A. L. Komaroff, M. D. Aronson, T. M. Pass, C. T. Ervin, and W. T. Branch, Jr., Science 222:927-929, 1983), our data indicated an infection rate of less than 1%.
Comparison of the modified Elek test and Wagatsuma agar for determination of the Kanagawa phenomenon of Vibrio parahaemolyticus
Authors: Nair G B , Saha M R , Sarkar B L , Pal S C
Published: January 2020

The modified Elek test and Wagatsuma agar were compared for their ability to detect the Kanagawa activity of 142 strains of Vibrio parahaemolyticus. The performance of the modified Elek test was on a par with that of the Wagatsuma agar as far as positivity was concerned, and the test was far superior to Wagatsuma agar in eliminating doubtful results. The results of the modified Elek test were not unduly influenced by the different types of agar used.
Comparison of polyclonal antiserum versus monoclonal antibodies for the rapid diagnosis of influenza A virus infections by immunofluorescence in clinical specimens
Authors: Shalit I , McKee P A , Beauchamp H , Waner J L
Published: January 2020

A pool of monoclonal antibodies was compared with polyclonal antiserum for the rapid detection of influenza A virus in 28 clinical specimens by immunofluorescence. Monoclonal antibodies showed higher sensitivity (69 versus 46%) and accuracy (86 versus 75%) and easier slide interpretation than did polyclonal antiserum. The procedure proved useful for rapid detection of a community outbreak of influenza A virus infection.
Preliminary evaluation of a rapid colorimetric method for the presumptive identification of group A streptococci and enterococci
Authors: Ellner P D , Williams D A , Hosmer M E , Cohenford M A
Published: January 2020

A rapid colorimetric method for the presumptive identification of group A streptococci and enterococci based upon pyroglutamyl aminopeptidase activity is described. Of 76 group A streptococcal isolates from primary plates, 83 gave positive reactions, and the remaining 7 were positive on retesting in pure culture. Of the 31 enterococcal isolates tested, all gave positive reactions. Despite occasional positive reactions with staphylococci and Klebsiella pneumoniae, the test could be useful and cost-effective in the clinical laboratory.
Cefoperazone and cefoperazone-sulbactam susceptibility tests with anaerobic bacteria by the thioglycolate disk elution method
Authors: Barry A L , Packer R R , Jones R N
Published: January 2020

Tests were performed with 104 anaerobic microorganisms to evaluate the thioglycolate disk elution technique for the detection of resistance to cefoperazone and cefoperazone-sulbactam. An unacceptably high false-resistance rate and a poor reproducibility record make the disk elution procedure unsatisfactory for routine testing of this drug or combination of drugs.
Media for the isolation of Aeromonas hydrophila
Authors: Kay B A , Guerrero C E , Sack R B
Published: January 2020

Isolation rates of Aeromonas hydrophila from stool samples of symptomatic and asymptomatic individuals were examined for several common enteric media. Sheep blood agar with 10 micrograms of ampicillin per ml, preceded by overnight enrichment in alkaline peptone water, yielded 2.6 times the number of isolates as the other media examined and is recommended for the isolation of A. hydrophila from humans.
Characterization of "Campylobacter pyloridis" by culture, enzymatic profile, and protein content
Authors: Megraud F , Bonnet F , Garnier M , Lamouliatte H
Published: January 2020

"Campylobacter pyloridis" has been recently described as a gastritis-associated bacterium. We studied 20 strains. The bacteria had most of the characteristics of Campylobacter spp. strains. They were hippurate negative and tolerant to triphenyl tetrazolium chloride (at 0.4 and 1 mg/ml). They grew on all the media commonly used in laboratories, although chocolate agar was the most effective for isolation. They grew in a microaerophilic atmosphere as well as in an atmosphere enriched in CO2 and when incubated at 37 degrees C but not at 30 or 42 degrees C. A total of 31 enzymes were present among the 78 studied. gamma-Glutamyl-transpeptidase activity was, in addition to urea hydrolysis, an interesting feature for the identification of these bacteria. The protein profiles of the 20 strains were similar.
Modified taurocholate-tellurite-gelatin agar for improved differentiation of Vibrio species
Authors: O'Brien M , Colwell R
Published: January 2020

A total of 78 strains, representing 21 Vibrio species, were examined by using taurocholate-tellurite-gelatin agar (TTGA) medium and modified TTGA medium containing 4-methylumbelliferyl-beta-D-galactoside (150 micrograms/ml). Modified TTGA medium allowed for simple and direct detection of beta-D-galactosidase (beta-gal) activity. This feature, in conjunction with other differential characteristics of TTGA medium, gave improved differentiation of the vibrios tested. The modified TTGA medium allowed for easy differentiation of Vibrio cholerae (beta-gal+) from Vibrio parahaemolyticus (beta-gal-). The 4-methylumbelliferyl-beta-D-galactoside substrate is inexpensive and very stable. Incorporation into the agar did not affect the performance of TTGA as a differential medium. The assay for beta-gal activity with this substrate was specific and sensitive.
Comparison of six methods for the detection of antibody to cytomegalovirus
Authors: McHugh T M , Casavant C H , Wilber J C , Stites D P
Published: January 2020

Five commercial assays were compared to a standardized complement fixation (CF) test for the detection of antibody to cytomegalovirus. Two hundred and thirty serum specimens were analyzed. In addition, nine pairs of acute- and convalescent-phase sera were tested by two of the commercial assays. The assays were compared as to sensitivity, specificity, and positive and negative predictive value, as well as incidence of false-positive and -negative results. Samples which did not agree in all the assays were retested and tested with an indirect fluorescent-antibody assay. Of 228 specimens, 103 (45.2%) were positive by CF. Of the 230 samples, 2 (0.9%) were inconclusive by CF and readable in the other assays. Of the 230 specimens, 97 (42.2%) were positive by an enzyme immunoassay (EIA; Litton Bionetics), 100 (43.5%) were positive by a second EIA (Abbott Laboratories), 104 (45.2%) were positive by a third EIA (M. A. Bioproducts). One hundred and eight (47.0%) were positive by indirect hemagglutination (IHA; Cetus Corporation), and 110 (47.8%) were positive by latex agglutination (LA; Hynson, Westcott and Dunning). Sensitivity and specificity were similar with all the assays (93 to 100%). The greater numbers of positive results by IHA and LA were confirmed by repeat CF testing at less than 1:8 dilution, and by indirect fluorescent-antibody assay. Acute- and convalescent-phase serum pairs showed a significant rise in antibody titer when tested by anticomplement immunofluorescence, IHA, and LA. There was good agreement among the assays, with LA having the highest sensitivity.
Characterization of nutritionally variant streptococci by biochemical tests and penicillin-binding proteins
Authors: Bouvet A , Villeroy F , Cheng F , Lamesch C , Williamson R , Gutmann L
Published: January 2020

A comparative study of 60 strains of nutritionally variant streptococci (NVS) with 34 strains of Streptococcus mitis and 37 strains of Streptococcus sanguis II showed the presence of a red chromophore which was absent in the other streptococcal species. By using the conventional microbiological tests, only small differences were found between the NVS and the two other related species. In contrast a clear-cut delineation was found by the API 20 Strep system of identification. All NVS contained pyrrolidonylarylamidase, an enzyme which was absent in S. mitis and S. sanguis II strains, and lacked the alkaline phosphatase enzyme which was present in 56% of S. mitis strains and 62% of S. sanguis II strains. According to the additional enzymatic and biochemical tests of the API 20 Strep system, there were three biotypes among NVS. The major biotype included 33 of 60 strains which were characterized by the presence of both alpha- and beta-galactosidases and the capacity to hydrolyze trehalose. This biotype also showed a specific pattern of penicillin-binding proteins. These results show that NVS are recognized as a separate variety distinct from S. mitis and S. sanguis II species, despite some common biochemical properties. Moreover, the delineation of 33 strains with a specific biotype and a specific penicillin-binding protein pattern strongly suggests that a large part of NVS strains belong to an individual species.
Characterization of a Yersinia enterocolitica antigen common to enterocolitis-associated serotypes
Authors: Díaz R , Urra E , Toyos J , Moriyon I
Published: January 2020

Yersinia enterocolitica synthesized an exocellular antigen common to the serotypes associated with enterocolitis but absent from other serotypes or from other Yersinia species. Both virulent Ca2+-dependent and avirulent Ca2+-independent isogenic pairs derived from the enterocolitis-associated serotypes synthesized the common antigen. Requirements for the synthesis of this common antigen were (i) the presence of metabolizable sugars and (ii) growth on a solid medium at 37 degrees C. The antigen was identified as a 24,000-dalton protein loosely associated with the cell surface but absent from either the cell envelope or the cytoplasmic fraction.
Evaluation of human hair sources for the in vitro hair perforation test
Authors: Salkin I F , Hollick G E , Hurd N J , Kemna M E
Published: January 2020

The in vitro hair perforation test for dermatophytes was evaluated with hair from males and females aged 6 months to 67 years, including hair of various natural colors and hair which had been bleached, tinted, curled, sprayed, or subjected to various combinations of these treatments. In contrast to published recommendations, the source of hair had no effect on this diagnostic procedure.
Identification of Chlamydia trachomatis by direct immunofluorescence applied in specimens originating in remote areas
Authors: Williams T , Maniar A C , Brunham R C , Hammond G W
Published: January 2020

The efficacy of the MicroTrak (Syva Co., Palo Alto, Calif.) direct immunofluorescence test for the detection of Chlamydia trachomatis was compared with cell culturing of fresh specimens obtained from patients attending a clinic on sexually transmitted disease and of frozen specimens delayed in transit from urban or remote physicians' offices and clinics. Direct immunofluorescence testing detected C. trachomatis more frequently than culturing of the same specimens when transit caused a delay in culturing.
Fatal Legionella maceachernii pneumonia
Authors: Wilkinson H W , Thacker W L , Brenner D J , Ryan K J
Published: January 2020

Legionella maceachernii, previously isolated only from the environment, was shown to be a cause of fatal pneumonia in an immunocompromised patient.
Serological observations of Pneumocystis carinii infection in humans
Authors: Tanabe K , Furuta T , Ueda K , Tanaka H , Shimada K
Published: January 2020

Serological examinations of Pneumocystis carinii antigen and antibody were performed in adult patients with P. carinii pneumonia. The antibody titer was assayed by indirect immunofluorescence, and antigenemia was detected by counterimmunoelectrophoresis. Profiles of the time course of antibody levels in serum indicated that development of the antibody occurred at an early stage of pneumonia and that peak titers were obtained during the febrile stage.
Comparison of ortho respiratory syncytial virus enzyme-linked immunosorbent assay and HEp-2 cell culture
Authors: Bromberg K , Tannis G , Daidone B , Clarke L , Sierra M F
Published: January 2020

Two hundred seventy nasopharyngeal aspirates were tested in duplicate with the Ortho Diagnostics, Inc. (Raritan, N.J.), respiratory syncytial virus antigen enzyme-linked immunosorbent assay. The test was sensitive (80 to 82%) and specific (96%) when compared with cell culture. The enzyme-linked immunosorbent assay detected seven antigen-positive specimens not among the 71 specimens that were positive for respiratory syncytial virus in cell culture. A blocking test confirmed those specimens as true positives (specificity, 100%).
Evaluation of a competitive enzyme-linked immunosorbent assay for porcine Escherichia coli heat-stable enterotoxin
Authors: Rönnberg B , Söderlind O , Wadström T
Published: January 2020

A competitive enzyme-linked immunosorbent assay (ELISA) was compared with the conventional suckling mouse assay for the identification of heat-stable enterotoxin (STa) in samples from piglets suffering from diarrhea. A total of 110 Escherichia coli isolates, 22 primary cultures, and 26 fecal samples from piglets up to 8 weeks of age with diarrhea were compared in parallel by both assays. Of the 110 isolates tested, all gave consistent results by the ELISA and the suckling mouse assay; 60 strains were negative and 50 strains produced STa by both tests. Identical results were obtained when 22 primary agar cultures were screened for STa production by both methods; 6 were found to produce STa, while 16 did not. When 26 fecal samples were tested for the presence of STa, 10 were negative and 12 were positive by both assays. One of the remaining four samples gave questionable positive results by both the suckling mouse assay and the ELISA, but E. coli isolated from this sample gave positive results by both tests. The remaining three samples were negative by the suckling mouse assay, but gave questionable positive results by the ELISA. E. coli isolates from these three samples were always negative by both assays. The ELISA used in this study provides a reliable and convenient method for diagnosing STa-producing enterotoxigenic E. coli of porcine origin.
Interlaboratory drug susceptibility testing of Mycobacterium tuberculosis by a radiometric procedure and two conventional methods
Authors: Siddiqi S H , Hawkins J E , Laszlo A
Published: January 2020

A total of 224 recent isolates of Mycobacterium tuberculosis from 163 patients selected to have multidrug resistance were tested against streptomycin (SM), isoniazid, rifampin, and ethambutol (EMB) by the rapid radiometric BACTEC method and two conventional proportion methods: the World Health Organization (WHO) method, using Lowenstein-Jensen medium; and the Veterans Administration reference laboratory for mycobacteria (VA) method, using Middlebrook 7H10 agar medium. The results were compared, focusing on the concentrations of the drugs in all three methods. Among the four drugs tested, most of the discrepancies in measured activity were observed with SM and EMB, generally because of differences in the drug concentrations used by the three methods. A 4-micrograms amount of SM in the BACTEC method was found to be slightly less active than 10 micrograms in the VA method and significantly more active than 4 micrograms of dihydrostreptomycin in the WHO method. With EMB, 2.5 micrograms in BACTEC was similar to 5 micrograms in the VA method and 2 micrograms in the WHO method, while 10 micrograms in the BACTEC method was found to be more active than 10 and 2 micrograms in the VA and WHO methods, respectively. To attain close agreement, drug concentrations used in the BACTEC method should be carefully selected when a comparison is to be made with any conventional method employed in a laboratory. Standardization of in vitro susceptibility testing is greatly needed to achieve uniformity among the test methods used to evaluate tuberculosis therapeutics.
Large-scale clinical comparison of the lysis-centrifugation and radiometric systems for blood culture
Authors: Brannon P , Kiehn T E
Published: January 2020

The Isolator 10 lysis-centrifugation blood culture system (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.) was compared with the BACTEC radiometric method (Johnston Laboratories, Inc., Towson, Md.) with 6B and 7D broth media for the recovery of bacteria and yeasts. From 11,000 blood cultures, 1,174 clinically significant organisms were isolated. The Isolator system recovered significantly more total organisms, members of the family Enterobacteriaceae, Staphylococcus spp., and yeasts. The BACTEC system recovered significantly more Pseudomonas spp., Streptococcus spp., and anaerobes. Of the Isolator colony counts, 87% measured less than 11 CFU/ml of blood. Organisms, on an average, were detected the same day from each of the two culture systems. Only 13 of the 975 BACTEC isolates (0.01%) were recovered by subculture of growth-index-negative bottles, and 12 of the 13 were detected in another broth blood culture taken within 24 h. Contaminants were recovered from 4.8% of the Isolator 10 and 2.3% of the BACTEC cultures.
Biotypes of enteropathogenic Escherichia coli strains from rabbits
Authors: Okerman L , Devriese L A
Published: January 2020

Forty-five enteropathogenic (enteropathogenic Escherichia coli-like) strains isolated in commercial rabbit farms were subdivided into four biotypes with the help of six carbohydrate fermentation tests, ornithine decarboxylase tests, and motility tests. E. coli strains which caused neonatal diarrhea in baby rabbits belonged to a single biotype, biotype 1, and displayed the same serotype antigens. Biotype 2 strains provoked diarrhea of variable severity in weaned rabbits and were also pathogenic for baby rabbits under laboratory conditions. Biotype 1 and biotype 2 strains resembled each other in many respects. Biotype 3 and biotype 4 (represented by a single strain) were highly pathogenic for weaned rabbits, but they provoked no symptoms or lesions in baby rabbits. Biotype 3 formed a homogeneous group of nonmotile strains which possessed the O15 antigen. Forty-two strains from nondiarrheic rabbits constituted a very heterogeneous collection of biotypes, most of which could easily be differentiated from the pathogenic types. Biotyping can be used to recognize rabbit pathogenic strains.
Agar media that indicate acid production from sorbitol by oral microorganisms
Authors: Kalfas S , Edwardsson S
Published: January 2020

Two varieties of agar medium (Trypticase [BBL Microbiology Systems]-serum-sorbitol-bromcresol purple agar [TSSB] and Trypticase-blood-sorbitol-CaCO3 agar [TBSCa]) indicating microbial acid production from sorbitol were tested. The media were devised for use in studies on the prevalence of sorbitol-fermenting human oral microorganisms incubated in an anaerobic or microaerophilic atmosphere containing 5 to 6% CO2. TSSB contains bromcresol purple as the pH indicator and NaHCO3 as the main buffering salt. TBSCa contains CaCO3 as both the buffering salt and the indicator of acid production. The growth yield of pure cultures of oral microorganisms on TBSCa was shown to equal that on blood agar incubated under similar conditions. TSSB inhibited the growth of several bacteria to various extents. The recovery of sorbitol-fermenting microorganisms from oral specimens was the greatest when the specimens were assayed with TBSCa. The poorer results obtained with TSSB were mainly due to the decoloration of the pH indicator in this medium and the presence of greater numbers of sorbitol false-positive colonies.
Humoral immunity against Francisella tularensis after natural infection
Authors: Koskela P , Salminen A
Published: January 2020

Forty-two subjects with acute tularemia were studied for the occurrence of C-reactive protein (CRP), and 73 subjects with acute tularemia or experience of the disease within the last 11 years were studied for immunoglobulin M (IgM), IgA, and IgG class-specific antibodies, agglutinating antibodies, and complement-fixing antibodies to Francisella tularensis by using an enzyme-linked immunosorbent assay (ELISA), the tube agglutination test, and a complement-fixing ELISA. The incubation time between infection and the outbreak of symptoms varied from 1 to 10 days, averaging 6.5 days. Elevated CRP concentrations were found in all samples taken in the first 6 days of illness, when the antibodies generally were absent. The highest CRP values, up to 165 mg/liter, occurred in the earliest samples and then decreased rapidly, being undetectable (less than 1 mg/liter) from 1 month after the onset of symptoms. Simultaneous though individually varying formation of IgM, IgA, and IgG class-specific antibodies to F. tularensis was demonstrable by ELISA in all the tularemia patients during the acute stage. In most cases, these antibodies appeared 6 to 10 days after the onset of symptoms, i.e., about 2 weeks after infection, reached their highest values at 4 to 7 weeks, and, despite a decreasing trend in their level, were still present 0.5 to 11 years after onset of tularemia, as demonstrable by the agglutination test and by the complement-fixing ELISA. Of the three methods used, ELISA for IgM, IgA, and IgG proved to be the most efficient for the early serodiagnosis of tularemia.
Adherence of coagulase-negative staphylococci to plastic tissue culture plates: a quantitative model for the adherence of staphylococci to medical devices
Authors: Christensen G D , Simpson W A , Younger J J , Baddour L M , Barrett F F , Melton D M , Beachey E H
Published: January 2020

The adherence of coagulase-negative staphylococci to smooth surfaces was assayed by measuring the optical densities of stained bacterial films adherent to the floors of plastic tissue culture plates. The optical densities correlated with the weight of the adherent bacterial film (r = 0.906; P less than 0.01). The measurements also agreed with visual assessments of bacterial adherence to culture tubes, microtiter plates, and tissue culture plates. Selected clinical strains were passed through a mouse model for foreign body infections and a rat model for catheter-induced endocarditis. The adherence measurements of animal passed strains remained the same as those of the laboratory-maintained parent strain. Spectrophotometric classification of coagulase-negative staphylococci into nonadherent and adherent categories according to these measurements had a sensitivity, specificity, and accuracy of 90.6, 80.8, and 88.4%, respectively. We examined a previously described collection of 127 strains of coagulase-negative staphylococci isolated from an outbreak of intravascular catheter-associated sepsis; strains associated with sepsis were more adherent than blood culture contaminants and cutaneous strains (P less than 0.001). We also examined a collection of 84 strains isolated from pediatric patients with cerebrospinal fluid (CSF) shunts; once again, pathogenic strains were more adherent than were CSF contaminants (P less than 0.01). Finally, we measured the adherence of seven endocarditis strains. As opposed to strains associated with intravascular catheters and CSF shunts, endocarditis strains were less adherent than were saprophytic strains of coagulase-negative staphylococci. The optical densities of bacterial films adherent to plastic tissue culture plates serve as a quantitative model for the study of the adherence of coagulase-negative staphylococci to medical devices, a process which may be important in the pathogenesis of foreign body infections.
Comparison of the Quantum II Bacterial Identification System and the AutoMicrobic System for the identification of gram-negative bacilli
Authors: Pfaller M A , Bale M J , Schulte K R , Koontz F P
Published: January 2020

The Quantum II Bacterial Identification System (BID; Abbott Laboratories) is a microprocessor-based spectrophotometric system for identification within 4 to 5 h of both enteric and nonenteric gram-negative bacilli. We compared the BID with the AutoMicrobic System (AMS; Vitek Systems, Inc.), using the most recent gram-negative identification card and software (AMS-GNI), for the identification of 501 clinical isolates of gram-negative bacilli, including 382 belonging to the Enterobacteriaceae and 119 nonenteric organisms. The API 20E (Analytab Products) was used as the reference system. The BID correctly identified 375 (98.2%) of the Enterobacteriaceae isolates and 111 (93.2%) of the nonenteric isolates; the AMS-GNI correctly identified 374 (97.9%) and 115 (96.6%) isolates, respectively. The BID identified all isolates within 5 h, whereas the AMS-GNI identified only 35% within this time period. The BID performed comparably to the AMS-GNI for the identification of most gram-negative bacilli. Simplicity, speed, and relatively low reagent cost make the BID a competitive system for many clinical laboratories.
Vibrio cincinnatiensis sp. nov., a new human pathogen
Authors: Brayton P R , Bode R B , Colwell R R , MacDonell M T , Hall H L , Grimes D J , West P A , Bryant T N
Published: January 2020

A halophilic gram-negative rod was isolated from blood and cerebrospinal fluid collected from a 70-year-old male having no known contact with seafood or salt water. Positive biochemical tests included oxidase, sensitivity to 0/129, O-nitrophenyl-beta-D-galactopyranoside, lysine decarboxylase and fermentation of glucose, salicin, n-inositol, sucrose, L-mannose, L-arabinose, and arbutin. Negative tests included indole, ornithine decarboxylase, arginine dihydrolase fermentation of lactose, and production of gelatinase and urease. The DNA base composition was 45.0 mol% guanine plus cytosine. Numerical taxonomy indicated 70% similarity with known reference Vibrio sp. strains. The 5S rRNA sequence for this strain has been determined: 5'-U G C C U G G C G A C C A U A G C G U U U U G G A C C C A C C U G A U U C C A U G C C G A A C U C A G U A G U G A A A C G A A A C A G C G U C G A U G G U A G U G U G G G G U C U C C C C A U G U G A G A G U A G A A C A U C G C C A G G C A U-3'. Based on the phenetic, molecular genetic, and nucleic acid sequencing data, it is concluded that Vibrio cincinnatiensis represents a new species of the genus Vibrio sensu strictu (as defined by 5S rRNA sequencing results). On a basis of 5S rRNA comparative sequence analysis, the organism appears to share a recent common ancestor with V. gazogenes (98% homology) and close ancestry with V. mimicus, V. fluvialis, and V. metschnikovii.
Determination of endotoxin in injectable antibiotic preparations by the chromogenic assay method using a Limulus reagent (Tachypleus hemocyte lysate) and a chromogenic substrate
Authors: Yano S , Hotta Y , Takahashi S
Published: January 2020

The effects of 50 antibiotics on the detection and determination of bacterial endotoxins by the chromogenic method using a Limulus reagent (Tachypleus hemocyte lysate) and a chromogenic substrate of p-nitroaniline derivatives were tested, and the antibiotic concentration for 50% inhibition of the chromogenic reaction in the presence of 0.5 ng of endotoxin (Escherichia coli 0111:B4) per ml was estimated. All the antibiotic preparations were depyrogenized by ultrafiltration treatment before they were subjected to the test. The reaction was conducted in the presence of a high concentration (0.5 M) of Tris buffer to constantly maintain the pH of the reaction mixture, and liberated p-nitroaniline was determined by high-pressure liquid chromatography. Several aminoglycosides (amikacin, bekanamycin, kanamycin, and streptomycin sulfate), bleomycin hydrochloride, and fosfomycin disodium showed no inhibition of the reaction up to 20 mg/ml. However, other antibiotics, including penicillins, cephalosporins, macrolides, and tetracyclines, inhibited the reaction concentration dependently. Polymyxin B sulfate was the most potent inhibitor, with less than 8 micrograms/ml for 50% inhibition. It was concluded that the chromogenic method can be applied to the detection and determination of endotoxin in most of the antibiotic preparations. An application of this method to carbenicillin disodium preparations was exemplified.
Use of gonozyme on urine sediment for diagnosis of gonorrhea in males
Authors: Schachter J , Pang F , Parks R M , Smith R F , Armstrong A S
Published: January 2020

We compared enzyme immunoassay (Gonozyme; Abbott Laboratories, North Chicago, Ill.) for detection of gonococcal antigen in urine sediments with urethral swab culture for diagnosis of gonorrhea in men attending a venereal disease clinic. The prevalence of infection was 14% by culture (27/196). The sensitivity of enzyme immunoassay was 93% (25/27) compared with the culture method, and the specificity was 99% (167/169). The ability to detect gonococcal antigen in urine sediment may provide the basis for a noninvasive method of screening for gonococcal infection.
Sensitive and specific monoclonal immunoassay for detecting yellow fever virus in laboratory and clinical specimens
Authors: Monath T P , Hill L J , Brown N V , Cropp C B , Schlesinger J J , Saluzzo J F , Wands J R
Published: January 2020

A solid-phase radioimmunoassay (RIA) was developed for the detection of yellow fever (YF) virus in infected cell culture supernatant fluid and clinical samples. The test employed a flavivirus group-reactive monoclonal antibody attached to a polystyrene bead support and a radiolabeled type-specific antibody probe in a simultaneous sandwich RIA format. Optimal assay conditions specified a 16-h incubation at high temperature (45 degrees C). Monoclonal antibody to tetanus toxoid was added to the radiolabeled probe to inhibit nonspecific binding. The sensitivity of the assay for cell culture-propagated virus was 2.0 log10 50% mosquito infectious doses per 100 microliters or 100 pg of gradient-purified virion protein per 100 microliters. Specificity, assessed with human sera from 512 patients with liver diseases other than YF, including acute viral hepatitis, showed a false-positive rate of 0.0 to 0.6%. Sera from experimentally infected rhesus macaques containing greater than 3.0 log10 units/100 microliter of YF virus were positive by RIA. Sera and liver tissue from human patients were found to be positive.
Peromyscus leucopus and Microtus pennsylvanicus simultaneously infected with Borrelia burgdorferi and Babesia microti
Authors: Anderson J F , Johnson R C , Magnarelli L A , Hyde F W , Myers J E
Published: January 2020

Borrelia burgdorferi, the etiologic agent of Lyme disease, and Babesia microti, the causative agent of human babesiosis, were isolated from 71 and 57%, respectively, of 14 specimens of Peromyscus leucopus and Microtus pennsylvanicus collected from Prudence and Patience Islands, R.I. Both pathogens were isolated from five individual rodents. The presence of these two infectious organisms in the same mammal suggests that individual larval Ixodes dammini may ingest both pathogens and subsequently transmit them in the nymphal stage.
Complex-specific immunoglobulin M antibody patterns in humans infected with alphaviruses
Authors: Calisher C H , el-Kafrawi A O , Al-Deen Mahmud M I , Travassos da Rosa A P , Bartz C R , Brummer-Korvenkontio M , Haksohusodo S , Suharyono W
Published: January 2020

Sera from humans with serologically confirmed eastern equine encephalitis, western equine encephalitis, Pogosta (Ockelbo), Mayaro, Ross River, and chikungunya virus infections were tested by immunoglobulin M (IgM) antibody capture enzyme immunoassay. Diagnostically useful IgM antibody titers were detected, and selected sera with high IgM antibody titers were tested for IgM antibody with nine heterologous alphaviruses. The results provide evidence for the complex specificity of IgM antibody and indicate the usefulness of this test in both individual cases and epidemic situations.