bluuebunny/crossref_metadata_2025 huggingface dataset:
Significance of quantitative enzyme-linked immunosorbent assay (ELISA) results in evaluation of three ELISAs and Western blot tests for detection of antibodies to human immunodeficiency virus in a high-risk population
Authors: Nishanian P , Taylor J M , Korns E , Detels R , Saah A , Fahey J L
Published: January 2020

The characteristics of primary (first) tests with three enzyme-linked immunosorbent assay (ELISA) kits for human immunodeficiency virus (HIV) antibody were determined. The three ELISAs were performed on 3,229, 3,130, and 685 specimens from high-risk individuals using the Litton (LT; Litton Bionetics Laboratory Products, Charleston, S.C.), Dupont (DP; E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), and Genetic Systems (GS; Genetic Systems, Seattle, Wash.) kits, respectively. Evaluation was based on the distribution of quantitative test results (such as optical densities), a comparison with Western blot (WB) results, reproducibility of the tests, and identification of seroconverters. The performances of the GS and the DP kits were good by all four criteria and exceeded that of the LT kit. Primary ELISA-negative results were not always confirmed with repeat ELISA and by WB testing. The largest percentage of these unconfirmed negative test results came from samples with quantitative results in the fifth percentile nearest the cutoff. Thus, supplementary testing was indicated for samples with test results in this borderline negative range. Similarly, borderline positive primary ELISA results that were quantitatively nearest (fifth percentile) the cutoff value were more likely to be antibody negative on supplementary testing than samples with high antibody values. In this study, results of repeated tests by GS ELISA showed the least change from first test results. DP ELISA showed more unconfirmed primary positive test results, and LT ELISA showed more unconfirmed primary negative test results. Designation of a specimen with a single ELISA quantitative level near the cutoff value as positive or negative should be viewed with skepticism. A higher than normal proportion of specimens with high negative optical densities by GS ELISA (fifth percentile nearest the cutoff) and also negative by WB were found to be from individuals in the process of seroconversion.
Detection of intrinsically resistant (heteroresistant) Staphylococcus aureus with the Sceptor and AutoMicrobic systems
Authors: Hansen S L , Walsh T J
Published: January 2020

Modified procedures for the Sceptor Gram-Positive MIC Panel and the Vitek AutoMicrobic System GPS-M Card were evaluated for their ability to detect methicillin-resistant (heteroresistant) Staphylococcus aureus. A total of 398 clinical isolates (including 222 methicillin-resistant S. aureus) obtained from 10 hospitals were tested. Both systems had 2% NaCl in the oxacillin wells. Sceptor MIC panels were inoculated with an organism suspension prepared from an 18- to 24-h blood agar plate and were inoculated for a full 24 h at 35 degrees C before MICs were read. All methicillin-resistant S. aureus isolates were detected as resistant to oxacillin at greater than or equal to 8 micrograms/ml by the Sceptor method and at greater than 2 micrograms/ml by the Vitek method. All 176 oxacillin-susceptible, methicillin-susceptible S. aureus isolates were correctly distinguished from methicillin-resistant S. aureus isolates by Sceptor. However, with the Vitek system 29 methicillin-susceptible S. aureus isolates tested as falsely resistant to oxacillin and four isolates tested as falsely resistant to vancomycin. The modified testing procedure with the Sceptor system can be used reliably for accurate susceptibility testing of methicillin-resistant and methicillin-susceptible S. aureus. The Vitek GPS-M card does not accurately discriminate between methicillin-resistant and methicillin-susceptible S. aureus with an oxacillin breakpoint of greater than 2 micrograms/ml.
Early testing of cell cultures for detection of hemadsorbing viruses
Authors: Minnich L L , Ray C G
Published: January 2020

Hemadsorption of primary monkey kidney cell cultures was commenced at 1 day after inoculation to evaluate how rapidly influenza A virus, influenza B virus, and parainfluenza virus types 1, 2, and 3 could be detected by this method from respiratory specimens. Overall, 38% of all isolates could be detected within 24 h of inoculation, and 69% could be detected within 48 h. All influenza A viruses and all but one influenza B virus were detected by day 3.
Centrifugation-shell vial technique for rapid detection of herpes simplex virus cytopathic effect in Vero cells
Authors: Pruneda R C , Almanza I
Published: January 2020

A centrifugation-shell vial technique for herpes simplex virus detected the virus in 50 (24.6%) of 203 specimens by cytopathic effect at 48 h, compared with detection of the virus in 47 (23.2%) specimens by immunofluorescence at 24 h. The rapid detection of cytopathic effect may be useful to laboratories that are not interested in typing all herpes simplex virus specimens but that wish to reduce the cost of herpesvirus cultures.
Factors affecting antimicrobial susceptibility of Fusobacterium species
Authors: Rowland M D , Del Bene V E , Lewis J W
Published: January 2020

Fifteen clinical isolates of Fusobacterium species were studied to determine their quality of growth on five agar media, their susceptibility to penicillin, cephalothin, cefoxitin, and cefotaxime, the inoculum effect, and the presence of L forms and beta-lactamase. Wilkins-Chalgren agar supported confluent growth best, but Fusobacterium nucleatum exhibited poor growth on all agar media. Most isolates exhibited poor reproducibility of MIC results with repeated agar dilution testing. However, most isolates were susceptible to all antibiotics at the breakpoint concentrations. No inoculum effect was observed, but preparation of an inoculum at a 0.5 McFarland nephelometric standard produced a lower than expected number of CFU (10(6) CFU) in some isolates. L forms were frequently seen. No beta-lactamase was found. The variability in MICs seen with beta-lactam antibiotics was not found when clindamycin was tested. MIC studies with Fusobacterium spp. may be complicated by poor growth on agar media, poor reproducibility, and small inoculum size.
Specificity study of kits for detection of group A streptococci directly from throat swabs
Authors: Facklam R R
Published: January 2020

A total of 78 Streptococcus strains, 15 Staphylococcus strains, and 2 Stomatococcus strains were used to test the specificity of 18 different antigen detection systems for group A streptococci and five products that detect a specific enzyme associated with group A streptococci. All streptococcal strains possessing the group A antigen were correctly identified with 31 different lots of reagents in the 18 antigen detection systems. The specificities of the 31 different lots of reagents ranged between 88.5 and 100%. A limited number of nonspecific reactions were observed with Enterococcus gallinarium, group C Streptococcus strain C23, and Staphylococcus aureus F49 and Cowan 1. The antigen detection kits that used enzymes as the extraction reagent gave slightly more specific results than did the kits that used chemical extraction reagents. The reagents in the five kits designed to detect the enzyme pyroglutamic acid arylamidase in Streptococcus pyogenes reacted positively with S. pyogenes (group A streptococcus); however, the reagents also reacted positively with all group D enterococcal streptococci and with about half of the staphylococcal strains treated. The nonspecificity of tests based on pyroglutamic acid arylamidase detection would seem to limit the usefulness of these kits with mixed cultures.
Simple and specific enzyme immunoassay using monoclonal antibodies for serotyping human rotaviruses
Authors: Coulson B S , Unicomb L E , Pitson G A , Bishop R F
Published: January 2020

An enzyme immunoassay for serotyping human rotaviruses in stools and in cell culture was developed. Hyperimmune rabbit antisera to rotaviruses were used as capture antibodies, and rotavirus-neutralizing mouse monoclonal antibodies specific for serotypes 1, 2, 3, and 4 were used as detection reagents. Partial purification of monoclonal antibodies and inclusion of skim milk powder in antibody diluents contributed to assay specificity. The sensitivity of this assay was greater than that of a direct enzyme immunoassay in which rotaviruses of the appropriate serotype were adsorbed directly to the solid phase. When fecal extracts were concentrated threefold, this serotyping enzyme immunoassay was of equal specificity and approached the sensitivity of electron microscopy for rotavirus detection. This assay is simple and rapid and is suitable for serotyping the large numbers of isolates obtained from epidemiological studies and vaccine trials.
Serotyping and electron microscopy studies of Staphylococcus aureus clinical isolates with monoclonal antibodies to capsular polysaccharide types 5 and 8
Authors: Hochkeppel H K , Braun D G , Vischer W , Imm A , Sutter S , Staeubli U , Guggenheim R , Kaplan E L , Boutonnier A , Fournier J M
Published: January 2020

Monoclonal antibodies to Staphylococcus aureus capsular polysaccharide types 5 and 8 were prepared and used to serotype 821 clinical isolates of S. aureus from four countries. The capsular polysaccharide-binding sites on the bacterial membrane were examined by transmission and scanning electron microscopy.
Serotype, antimicrobial susceptibility, and pathogenicity of Erysipelothrix rhusiopathiae isolates from tonsils of apparently healthy slaughter pigs
Authors: Takahashi T , Sawada T , Muramatsu M , Tamura Y , Fujisawa T , Benno Y , Mitsuoka T
Published: January 2020

Erysipelothrix rhusiopathiae was isolated from tonsils of 63 (10.5%) of 600 apparently healthy slaughter pigs in the Kanto area of Japan in February and July 1984. The isolation rate was significantly higher during July than in February. Of these 63 isolates, 34 isolates (54.0%) were serotype 7, 20 isolates (31.7%) were serotype 2, 6 isolates (9.5%) were serotype 6, and 1 isolate (1.6%) each was serotype 11, 12, or 16. All isolates of serotypes 2, 6, 11, 12, and 16 were highly virulent for mice, whereas most isolates of serotype 7 were weakly virulent. In swine, all isolates of serotype 2 were highly virulent, capable of inducing generalized urticarial lesions with depression and anorexia. On the other hand, 37 of 43 isolates of serotypes other than 2 induced no clinical signs, and the remaining 6 isolates induced local urticarial lesions at the site of inoculation in swine. The MIC of dihydrostreptomycin ranged from 1.56 to 100 micrograms/ml. All of the dihydrostreptomycin-resistant strains belonged to serotype 2. The high virulence of E. rhusiopathiae strains of serotype 2 harbored in the tonsils suggests a possible role of such strains in the cause of swine erysipelas. In contrast, members of the other nonvirulent or weakly virulent group, mainly serotype 7 strains, were considered to be resident in porcine tonsils.
Evaluation of the AutoMicrobic system for susceptibility testing of aminoglycosides and gram-negative bacilli
Authors: Hindler J A , Bruckner D A
Published: January 2020

The AutoMicrobic system (AMS; Vitek Systems, Inc., Hazelwood, Mo.) was compared with a reference broth microdilution MIC method to determine the accuracy and reproducibility of aminoglycoside susceptibility testing of gram-negative bacilli. Stock clinical isolates (n = 176) which demonstrated resistance to at least one aminoglycoside, extended-spectrum penicillin, or broad-spectrum cephalosporin (or a combination) were selected for this study. Isolates with moderate susceptibility to the aminoglycosides were also included. Of these isolates, 116 were either resistant or moderately susceptible to one or more of amikacin, gentamicin, netilmicin, and tobramycin. When AMS MIC results for 704 antimicrobial agent-organism combinations were compared with parallel microdilution MIC results, exact agreement (AMS MIC = reference MIC) rates were: amikacin, 71.6%; gentamicin, 71.6%; netilmicin, 83.0%; and tobramycin, 69.3%. Agreement rates within +/- 1 log2 dilution were: amikacin, 96.0%; gentamicin, 93.8%; netilmicin, 97.2%; and tobramycin, 96.0%. When National Committee for Clinical Laboratory Standards criteria were used to qualitatively evaluate performance, the overall agreement rates were: amikacin, 100.0%; gentamicin, 99.4%; netilmicin, 98.9%; and tobramycin, 99.4%. There were only four very major discrepancies, which represented 0.6% of the tests performed, and there were no major discrepancies. The percentages of minor discrepancies were: amikacin, 9.6%; gentamicin, 14.2%; netilmicin, 11.9%; and tobramycin, 10.8%. Of the overall average of 11.6% minor discrepancies, 9.7% occurred even though the AMS MIC was within +/- 1 log2 dilution of the reference MIC. The intralaboratory reproducibility ranged from 93.3 to 100% for the four drugs examined. With this challenge group of gram-negative bacilli, the AMS generated aminoglycoside MIC results that were comparable to those obtained by a reference broth microdilution method.
Modification of Grimont biotyping system for epidemiologic studies with nosocomial Serratia marcescens isolates
Authors: Sifuentes-Osornio J , Gröschel D H
Published: January 2020

A modification of the Grimont biotyping system for Serratia marcescens permitted the rapid testing of nosocomial strains by a plate-disk assimilation technique instead of with individual substrate tubes.
Comparison of the Gono-Pak system with the candle extinction jar for recovery of Neisseria gonorrhoeae
Authors: Devaux D L , Evans G L , Arndt C W , Janda W M
Published: January 2020

Maximum CO2 levels in the Gono-Pak system were obtained 2 h after activation, with a mean value of 1.5%. Although this is less than the 2 to 3% CO2 level obtained with the candle jar, Gono-Pak produced comparable recovery of Neisseria gonorrhoeae in 357 clinical specimens and stock cultures. Using adjustable CO2 incubators, we found the recovery at 1% CO2 to be comparable to that at 5%, whereas 10% CO2 was inhibitory.
Expanded clinical spectrum of infections caused by Proteus penneri
Authors: Krajden S , Fuksa M , Petrea C , Crisp L J , Penner J L
Published: January 2020

Strains of Proteus penneri from seven abdominal wounds (after bowel resection), five urine samples, and eight other sites were isolated in mixed cultures. Seven urine isolates were in pure cultures. All infections were nosocomially acquired, indicating that complete identification of P. penneri in the clinical laboratory is warranted.
Comparison of the AMS gram-negative susceptibility flex panel GNS-V and agar disk diffusion for testing of Pseudomonas aeruginosa
Authors: Henry D A , Smith J A , Jones M A
Published: January 2020

Sixty Pseudomonas aeruginosa isolates were tested by the agar disk diffusion, AMS Vitek GNS-V flex panel (Vitek Systems, Inc., Hazelwood, Mo.), and agar dilution methods. Although the results of aminoglycoside tests were satisfactory, those of piperacillin and cefoperazone by Vitek GNS-V (T2.05 program) were not acceptable.
Antimicrobic susceptibility and plasmid profile analysis as identity tests for multiple blood isolates of coagulase-negative staphylococci
Authors: Hartstein A I , Valvano M A , Morthland V H , Fuchs P C , Potter S A , Crosa J H
Published: January 2020

We compared a disk diffusion antimicrobic susceptibility panel with plasmid DNA profiles as tests for identity of 106 isolates of coagulase-negative staphylococci cultured from the blood of 45 patients on multiple occasions. The antimicrobic panel included penicillin, oxacillin, clindamycin, trimethoprim-sulfamethoxazole, chloramphenicol, tetracycline, tobramycin, kanamycin, and gentamicin. Nineteen patterns of antimicrobic susceptibility were found. The most common pattern was present in 25% of the isolates, and at least one isolate from 31% of the patients had this pattern. Forty-seven distinct plasmid DNA profiles were found. The most common plasmid profile was present in 8.5% of the isolates, and at least one isolate from 15% of the patients had this profile. Twenty-eight patients had multiple isolates that were identical by plasmid profile analysis. Twenty-seven (96%) of these patients had isolates that were also identical by antimicrobic susceptibility. Nineteen patients had multiple isolates that were different by plasmid profile analysis. In 18 (95%) of these patients, the isolates were also different by antimicrobic susceptibility. Although plasmid DNA profile analysis is a more discriminating tool, these data confirm that a selected disk diffusion antimicrobic susceptibility panel may be used to screen multiple blood isolates of coagulase-negative staphylococci for identity or differences.
Cross-reactions in Legionella antisera with Bordetella pertussis strains
Authors: Benson R F , Thacker W L , Plikaytis B B , Wilkinson H W
Published: January 2020

While preparing slide agglutination test antisera and immunofluorescence conjugates for the identification of Legionella species and serogroups, we found that several of the reagents cross-reacted with Bordetella pertussis strains. To determine the extent of this problem and to estimate the specificity of Legionella reagents, we tested slide agglutination test antisera against 22 species and 35 serogroups with 92 bacterial strains representing 19 genera. The only cross-reactions observed were with Legionella pneumophila serogroup 10, L. maceachernii, L. gormanii, and L. feeleii serogroup 1 antisera and 4 of 10 B. pertussis strains. Nineteen conjugates, previously available from the Centers for Disease Control but no longer distributed as reference reagents, were tested with the four cross-reactive B. pertussis strains. Two conjugates, L. micdadei and L. wadsworthii, stained three of the B. pertussis strains at a fluorescence intensity of greater than or equal to 3+. All cross-reactions were removed from the antisera and conjugates by absorption with the cross-reacting strain without diminishing the homologous reaction. Special emphasis should be placed on the identification and removal of cross-reactions in Legionella reagents with strains that have similar morphologic and growth characteristics.
Medium supplementation for growth of Campylobacter pyloridis
Authors: Buck G E , Smith J S
Published: January 2020

Experiments were conducted to define the growth requirements of Campylobacter pyloridis, a newly discovered organism associated with gastritis and peptic ulcers. Two clinical isolates were streaked onto various media, and growth was assessed semiquantitatively according to relative colony size and extent of growth through the streak. The growth obtained on fresh chocolate agar, composed of GC agar base (Difco Laboratories, Detroit, Mich.) plus 1% hemin, was used as a reference. The organism grew on both GC agar base and Mueller-Hinton agar without supplementation, but less well than on chocolate agar. No growth occurred on tryptic soy or brucella agar. Supplementation of brucella agar with 1 or 5% horse serum or 0.1 or 1.0% cornstarch supported growth to about the same level as GC agar base alone. Supplementation with hog gastric mucin or methyl cellulose supported weak growth. GC agar base with 1% starch or 0.2% charcoal supported growth as well as chocolate agar. Experiments with brucella broth provided similar results. Cornstarch and methyl cellulose partially replaced the requirement for serum, but methyl cellulose and hog gastric mucin did not. These results show that some form of supplementation is necessary for growth of C. pyloridis. This can be starch, serum, charcoal, or hemin, but hemin is not an absolute requirement for growth.
Comparison of kill-kinetic studies with agar and broth microdilution methods for determination of antimicrobial activity of selected agents against members of the Bacteroides fragilis group
Authors: Stratton C W , Weeks L S , Aldridge K E
Published: January 2020

Kill-kinetic studies often are used to determine the rate and degree of killing of aerobic bacteria by antimicrobial agents. Few studies, however, make use of this method for determining antimicrobial activity against anaerobic bacteria. To evaluate kill-kinetic studies for anaerobes, kill-kinetic studies were performed for selected antimicrobial agents against members of the Bacteroides fragilis group and compared with MICs obtained by using a reference agar dilution method and a broth microdilution method. Results of the kill-kinetic studies showed that the degree of killing over a 24-h test period was related to the MIC for the test organism. In general, the higher the MIC of an antimicrobial agent for a test organism, the less the killing observed. In addition, these studies demonstrate subtle differences in bactericidal activity at various concentrations of the antimicrobial agents, which cannot be determined by agar or broth dilution methods. Kill-kinetic studies are a useful addition to dilution methods for the evaluation of antimicrobial agents against anaerobes.
Specificity of antibodies from human sera for Naegleria species
Authors: Marciano-Cabral F , Cline M L , Bradley S G
Published: January 2020

Serum samples from adult humans in North Carolina and Pennsylvania were assayed for antibodies against four Naegleria species: N. australiensis, N. fowleri, N. gruberi, and N. lovaniensis. Agglutinating activities of serum samples from North Carolina subjects were higher for N. fowleri than were those from Pennsylvania subjects. The distributions of agglutination titers of human serum samples for N. australiensis, N. gruberi, and N. lovaniensis were heterogeneous. The agglutination capabilities of selected serum samples absorbed with rounded, killed trophozoites of N. australiensis and N. lovaniensis were distinctly different, as were those of serum samples absorbed with N. fowleri and N. gruberi. N. australiensis and N. gruberi shared some agglutinating antigens, as did N. fowleri and N. lovaniensis. The agglutinating activities of most serum samples correlated with the capability of their immunoglobulin M (IgM) to bind to antigens in extracts of Naegleria species but not with the capabilities of their IgG to bind to antigens of Naegleria species. Absorption of IgM binding capability with rounded, killed trophozoites established that N. gruberi was distinctly different from N. fowleri and N. lovaniensis but that N. fowleri and N. lovaniensis shared surface antigens. The proteins in extracts of the four Naegleria species were subjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and tested for their ability to bind immunoglobulins in a serum sample. The antigens of the four species that bound IgM or IgG in the tested serum sample were separated by SDS-PAGE, and when they were incubated with anti-IgM or anti-IgG, they gave distinct profiles. There was one distinct, shared antigen that had a molecular size of 40,000 daltons. Absorption of the test serum with killed, rounded trophozoites did not markedly change the immunoglobulin binding profile for Naegleria internal antigens separated by SDS-PAGE and did not remove the shared 40,000-dalton protein(s). These results demonstrate that the four Naegleria species have antigenically distinct surfaces and that humans have been individually exposed to antigens of Naegleria species.
Detection of cytomegalovirus infections in specimens other than urine by the shell vial assay and conventional tube cell cultures
Authors: Paya C V , Wold A D , Smith T F
Published: January 2020

Blood, bronchoscopy-lavage, biopsy (lung, liver, kidney), sputum, and other (cecum, bone) specimens were inoculated into shell vials and conventional cell tube cultures seeded with MRC-5 cells over a 23-month period. Of 1,472 specimens, 182 (12.4%) yielded cytomegalovirus (CMV)-positive results from 81 patients. Significantly more CMV-positive specimens were detected in shell vials (n = 154; 84.6%) than in conventional tube cell cultures (n = 126; 69.2%) (P less than 0.01). We found that 98 (53.8%) of the total 182 and 41 (42.7%) of the 96 blood specimens positive for CMV were detected by both the shell vial assay and conventional tube cell cultures. However, 56 (30.7%) of the total 182 and 31 (32.3%) of the 96 blood specimens positive for CMV were obtained exclusively in shell vials after detection with monoclonal antibody. Alternatively, 28 (15.4%) of the total 182 and 24 (25%) of the 96 blood specimens positive for the virus were isolated only in conventional tube cell cultures. Thus, although the shell vial assay was more sensitive and rapid than the conventional tube cell culture method, both systems must be used, especially for blood specimens, for the laboratory diagnosis of CMV infections.
New method of serotyping Escherichia coli: implementation and verification
Authors: Bettelheim K A , Thompson C J
Published: January 2020

This paper describes the implementation and verification of a new method of serotyping Escherichia coli based on a mathematical analysis of the results of agglutination reactions between standard O antigens of E. coli and rabbit antisera raised against them. Details of the new method, which uses on average one-fifth of the serum used for the old method and is now in routine use in New Zealand, are given.
Identification of Streptococcus faecalis and Streptococcus faecium and susceptibility studies with newly developed antimicrobial agents
Authors: Kim M J , Weiser M , Gottschall S , Randall E L
Published: January 2020

Identification and susceptibility studies were performed on 301 blood and urine Streptococcus faecalis and Streptococcus faecium isolates. Strep Trio-Tubes S4, S5, and S3 (Carr-Scarborough Microbiologicals, Inc.) were compared with conventional methods for accuracy and rapidity. Of 282 isolates identified as S. faecalis, 98% were identified by species in 4 h with Trio-Tubes; the same percentage of isolates analyzed by conventional methods were identified in 24 h. All 14 S. faecium isolates (approximately 5% of the total number of isolates) were identified by Trio-Tubes in 24 h. In vitro MIC susceptibility testing of the isolates was performed by the Dynatech 2000 microdilution technique (Dynatech Laboratories, Inc.). Several newly developed antimicrobial agents, including imipenem (a carbapenem) and some of the quinolone drugs, i.e., CI-934, ciprofloxacin, A-56619, A-56620, amifloxacin, norfloxacin, and enoxacin, were tested, as were ampicillin, erythromycin, and vancomycin. Both ampicillin and vancomycin showed good activity against S. faecalis, with MICs for 90% of isolates tested (MIC90S) of 1 and 2 micrograms/ml, respectively; with S. faecium, ampicillin exhibited an MIC90 of 16 micrograms/ml and vancomycin exhibited an MIC90 of 2 micrograms/ml. Of the newer antimicrobial agents, imipenem and CI-934 exhibited the greatest activity against S. faecalis strains, with MIC90S of 2 and 0.5 micrograms/ml, respectively. MBCs against the isolates were determined with CI-934, with 90% of S. faecalis strains showing MBCs of 1 microgram/ml or less.
Yield, clinical significance, and cost of a combination BACTEC plus Septi-Chek blood culture system
Authors: Thomson R B , File T M , Tan J S , Evans B L
Published: January 2020

A blood culture was performed by adding a vented Septi-Chek bottle (Roche Diagnostics, Div. Hoffmann-LaRoche Inc., Nutley, N.J.) to a standard BACTEC system (Johnston Laboratories, Inc., Towson, Md.) blood culture. The yield of bacteremic patients, the clinical significance of organisms detected, and the cost of the combination system were compared with those of the standard BACTEC system alone. Each culture included 20 ml of blood divided among a BACTEC 6B aerobic bottle (5 ml), a BACTEC 7D anaerobic bottle (5 ml), and a Septi-Chek bottle equipped with a slide subculture attachment (10 ml). Significant isolates grew in 9.6% of the 2,269 cultures evaluated. The combination BACTEC plus Septi-Chek system detected 25% more bacteremic patients than the BACTEC system alone, 129 patients versus 103. The 26 bacteremic patients detected by only the added Septi-Chek bottle included 7 whose organism was isolated from blood alone and 19 whose organism was in mixed or pure culture from a second source. Detection of the organism resulted in alteration of antimicrobial therapy in 17 of these 26 patients. The combination system, which cultured a 20-ml blood volume, cost $11,000 more during the study period than the BACTEC system alone, which cultured a 10-ml volume. Reimbursement under the diagnosis-related group system was increased by $23,000 as a result of documentation of sepsis in these 26 patients. Blood volume and, possibly, the use of multiple blood culture systems are important factors when selecting a blood culture procedure for routine use.
Prospective study of enteric Campylobacter infections in children from birth to 6 months in the Central African Republic
Authors: Georges-Courbot M C , Beraud-Cassel A M , Gouandjika I , Georges A J
Published: January 2020

A survey of enteric Campylobacter infections was performed in Bangui, Central African Republic, with a cohort of 127 children from birth to 6 months of age by biweekly culture of stools; 82 infections were observed, and 41.7% of the children presented at least 1 infection before 6 months of age. Only 15.9% of the infected children had a diarrheic syndrome; moreover, 61.5% of these diarrheic children had another enteropathogen associated with Campylobacter species. In about half the cases, Campylobacter spp. were excreted for more than 4 days. More than half of the children had at least one diarrheic episode, for which an enteropathogen was identified in one third of the cases, before 6 months of age.
Detection of galactomannan antigenemia by enzyme immunoassay in experimental invasive aspergillosis
Authors: de Repentigny L , Boushira M , Ste-Marie L , Bosisio G
Published: January 2020

A sensitive enzyme immunoassay (EIA) for galactomannan antigenemia that avoids the use of radioisotopes was devised. Three carbohydrate-rich antigenic fractions were purified from Aspergillus fumigatus 2085: a cold alkali extract (CA) from mycelium, an acetone-precipitated pyridine extract (APSK-66) from mycelium, and a methanol precipitate from culture filtrate. CA and APSK-66 were further purified by gel filtration and ion-exchange chromatography, respectively. An acid hydrolysate of CA contained only mannose and galactose, as determined by gas-liquid chromatography. Rabbit antisera were raised against conidia, mycelia, and cell walls of A. fumigatus. By indirect EIA, the best immunoglobulin G response (1/8,000) was obtained against CA in rabbits immunized intravenously with cell walls. Antigenemia was detected by indirect EIA inhibition in heat-dissociated sera of four immunosuppressed rabbits that were infected intravenously but was absent in two uninfected controls. The circulating antigen was resistant to pronase, was adsorbed onto concanavalin A, and had a molecular size of 50 to 100 kilodaltons.
Diagnosis of chlamydial infection in women attending antenatal and gynecologic clinics
Authors: Smith J W , Rogers R E , Katz B P , Brickler J F , Lineback P L , Van der Pol B , Jones R B
Published: January 2020

Two antigen detection systems (MicroTrak [MT], Syva Co., Palo Alto, Calif.; and Chlamydiazyme [CZ], Abbott Laboratories, North Chicago, Ill.) were compared with semiquantitative culture for diagnosis of chlamydial infection in 1,059 patients. Cultures were done on microtiter plates and blind passaged once. Culture-negative but CZ- or MT-positive specimens were recultured. True positives were positive by either initial or repeat cultures. Of 827 nonpregnant and 231 pregnant patients, 9.1 and 12.1%, respectively, had positive cultures. Overall sensitivity of the initial culture was 48.5% without passage and 86.4% with passage. The sensitivity of CZ was 67%. The sensitivity of MT in our laboratory was 50%; however, further review of these specimens by Syva employees gave a combined sensitivity of 71.6%. MT and CZ were more sensitive for pregnant patients (MT, 84.6%; CZ, 85.7%) than for nonpregnant patients (MT, 65.5%; CZ, 60.0%). All the tests had specificities above 95%. Of the specimens that were positive after initial culture without subculture, MT-negative specimens had a mean of 3.7 inclusions in culture, and MT-positive specimens had a mean of 24.8 (P = 0.002); CZ-negative specimens had a mean of 4.3 inclusions, and CZ-positive specimens had a mean of 20.0 (P = 0.026). In addition, cultures of specimens from pregnant patients had more inclusions than did those from gynecology patients, but this was not statistically significant (P = 0.096). No method is ideal; however, MT and CZ were less sensitive than was this culture system for detecting chlamydial infection in patients in gynecology clinics and were of comparable sensitivity for pregnant patients.
Aeromonas veronii, a new ornithine decarboxylase-positive species that may cause diarrhea
Authors: Hickman-Brenner F W , MacDonald K L , Steigerwalt A G , Fanning G R , Brenner D J , Farmer J J
Published: January 2020

In 1983, the vernacular name Enteric Group 77 was coined for a group of strains that had been referred to our laboratory as "possible Vibrio cholerae except for gas production." By DNA-DNA hybridization (hydroxyapatite, 32P), 8 of 10 strains of Enteric Group 77 were very highly related to the labeled strain 1169-83 (74 to 100% at 60 degrees C and 75 to 100% at 75 degrees C; percent divergence, 0.0 to 2.5). Type strains of six other Aeromonas species were 45 to 66% related (60 degrees C) to strain 1169-83, but type strains of 27 Vibrio species were only 2 to 6% related. The name Aeromonas veronii is proposed for the highly related group of nine strains formerly known as Enteric Group 77. The type strain is designated as ATCC 35604 (CDC 1169-83). Strains of A. veronii grew well at 36 degrees C and had positive reactions at this temperature for indole, methyl red, Voges-Proskauer, citrate, lysine and ornithine decarboxylases, DNase, lipase, and motility; the strains had negative reactions for arginine decarboxylase, H2S, urea, and malonate. The following sugars were fermented: D-glucose (acid and gas), cellobiose (seven of nine strains), D-galactose, maltose, D-mannitol, D-mannose, alpha-methyl-D-glucoside (eight of nine strains), salicin, sucrose, and trehalose. The following sugars were not fermented: adonitol, L-arabinose, D-arabitol, dulcitol, erythritol, myo-inositol, lactose, raffinose, L-rhamnose, D-sorbitol, and D-xylose. The positive ornithine decarboxylase reaction differentiates A. veronii from other Aeromonas species. The antibiogram of A. veronii is typical of other Aeromonas strains (resistance to ampicillin and carbenicillin and susceptibility to most other agents). A. veronii strains were isolated from three clinical sources: respiratory secretions of four victims of drowning or near drowning in fresh water (probably not clinically significant); infected wounds of two patients previously exposed to fresh water (unknown clinical significance); and stools from three patients with diarrhea (probably clinically significant).
beta-Glucosidase in Candida albicans and its application in yeast identification
Authors: Polacheck I , Melamed M , Bercovier H , Salkin I F
Published: January 2020

In this report we attempt to explain the discrepancy between beta-glucosidase (EC 3.2.1.21) activity in Candida albicans as measured by commercial kits and that found in an experimental assay. beta-Glucosidase activity in American and Israeli isolates of C. albicans was evaluated with the API ZYM and YeastIdent systems (Analytab Products) and with experimental biochemical assays. Activity was found with whole cells and cell extracts of isolates from both sources. The greatest beta-glucosidase activity was found at pH 5.0 and with p-nitrophenyl-beta-glucopyranoside (PNP-BDG) as the substrate. In assays with beta-naphthyl-beta-D-glucopyranoside and 6-bromo-2-naphthyl-beta-D-glucopyranoside (6-Br-2-naphthyl-BDG), no enzyme activity was detected in whole cells and only limited activity was found in cell extracts of isolates from both sources. In studies with PNP-BDG at pH 5.0 and 7.5, 29 to 38% less activity was found at both pHs with American whole cells, and minor activity (20%) was found at pH 7.5 with isolates from both sources. Because assays with PNP-BDG in cell extracts of isolates from both sources showed no significant differences in activity, the more limited beta-glucosidase activity in American whole cells was most likely due to less efficient transport. Because the API ZYM system uses 6-Br-2-naphthyl-BDG as the substrate and because the substrate is buffered at pH 7.5 in the API YeastIdent kit, both systems appear to be of limited value for the detection of beta-glucosidase activity in C. albicans.
Development of a broth medium for Bacteroides forsythus
Authors: Dzink J L , Smith C M , Socransky S S
Published: January 2020

Bacteriodes forsythus has been implicated as a possible pathogen in certain destructive periodontal diseases. This species has been extremely difficult to grow in broth, thus hampering its characterization and identification. A broth medium was developed consisting of 30 g of phytone, 10 g of NaCl, and 1 g of filter-sterilized L-cysteine per liter. The medium supported the growth of 23 fresh isolates of B. forsythus from six subjects to optical densities averaging 0.71 +/- 0.20 (standard deviation) at 550 nm after 48 to 72 h of anaerobic incubation.
FiltraCheck-UTI, a rapid, disposable system for detection of bacteriuria
Authors: Longoria C C , Gonzalez G A
Published: January 2020

The initial evaluation of the FiltraCheck-UTI bacteriuria detection system is described. The colorimetric test, which utilizes a disposable filter disk and a stable reagent system, does not require instrumentation. The test procedure is simple and may be performed in less than 1 min. Results obtained with the FiltraCheck-UTI system were compared with those obtained by conventional semiquantitative culturing. Of 1,198 urine specimens evaluated, 202 (16.9%) were determined to be significant positives at greater than or equal to 10(5) CFU/ml by the culture method. The sensitivity and specificity of the FiltraCheck-UTI system were 96.5 and 79.7%, respectively, and the negative predictive value was 99.1%. The high sensitivity, rapidity, simplicity, and unique disposable format of the FiltraCheck-UTI system offer significant advantages over other commonly used screening methods.
Evaluation of a rapid latex slide agglutination test for herpes simplex virus as a specimen screen and culture identification method
Authors: Halstead D C , Beckwith D G , Sautter R L , Plosila L , Schneck K A
Published: January 2020

A total of 449 clinical specimens and 199 culture fluids were tested using the Virogen Herpes Slide Test (Wampole Laboratories, Div. Carter-Wallace, Inc., Cranbury, N.J.), a rapid latex agglutination procedure. The results were compared with those obtained with isolation of herpes simplex virus in cell culture followed by identification using immunoperoxidase or fluorescent reagents. The sensitivity, specificity, and positive and negative predictive values of the direct test were 49.7, 93.4, 96.0, and 37.1%, respectively. The sensitivity and specificity of the latex agglutination test for culture confirmation were 75.9 and 100%, respectively.
Simultaneous seeding and infecting of shell vials for rapid detection of cytomegalovirus infection
Authors: Espy M J , Smith T F
Published: January 2020

Fifty cytomegalovirus isolates were used to infect shell vials containing confluent MRC-5 cell monolayers and shell vials which were seeded with MRC-5 cells at the time of inoculation. All 50 of the isolates were detected by immunofluorescence in shell vials containing confluent monolayers, whereas 39 (78%) of the isolates were detected in shell vials that had been seeded and inoculated simultaneously (P less than 0.001). Preformed monolayers of cells in shell vials provide the most sensitive system for the detection of cytomegalovirus infection.
"Campylobacter cinaedi" bacteremia: case report and laboratory findings
Authors: Cimolai N , Gill M J , Jones A , Flores B , Stamm W E , Laurie W , Madden B , Shahrabadi M S
Published: January 2020

"Campylobacter cinaedi" was isolated from the blood of a 29-year-old homosexual man with previously diagnosed acquired immune deficiency syndrome. Subculturing of the organism was achieved with the use of 7% lysed horse blood and 10% sheep blood agars at 37 degrees C in a microaerophilic atmosphere. Problems associated with the culturing of this organism are reviewed.
Experimental gingivitis in a Down's syndrome child and sibling
Authors: Reuland-Bosma W , van Dijk J , Rozeboom T , Poppema S
Published: January 2020

Biopsies were taken from a child with Down's syndrome and her sibling under experimental gingivitis conditions and analyzed with monoclonal antibodies. At first, plaque caused a shift from a predominance of T cells to a predominance of B cells. Later, a gradual increase of T cells and a looser arrangement of B cells were observed.
Prosthetic valve endocarditis caused by Acinetobacter calcoaceticus subsp. lwoffi
Authors: Weinberger I , Davidson E , Rotenberg Z , Fuchs J , Agmon J
Published: January 2020

Acinetobacter spp. are uncommon etiologic agents of prosthetic valve endocarditis. Two patients with Acinetobacter calcoaceticus subsp. lwoffi prosthetic valve endocarditis are described. The patients were successfully treated with antibiotics (cefotaxime sodium and gentamicin sulfate); thus, we suggest medical treatment rather than early valve replacement in this particular type of infection.
Detection of herpes simplex virus in direct specimens by immunofluorescence assay using a monoclonal antibody
Authors: Pouletty P , Chomel J J , Thouvenot D , Catalan F , Rabillon V , Kadouche J
Published: January 2020

A monoclonal antibody (MAb), designated CHA 437, was developed against herpes simplex virus (HSV). This MAb (isotype, immunoglobulin G2b K) reacted with HSV type 1 and HSV type 2. It showed no cross-reactivity with varicella-zoster virus, cytomegalovirus, or Epstein-Barr virus. Direct detection of HSV antigen in clinical specimens using indirect immunofluorescence with this MAb was compared with tissue culture isolation. For the 682 specimens tested, the direct specimen test gave a sensitivity of 84.6% and a specificity of 95.7%.
Prevalent patterns of serotype-specific seroconversion in Mexican children infected with rotavirus
Authors: Puerto F I , Padilla-Noriega L , Zamora-Chávez A , Briceño A , Puerto M , Arias C F
Published: January 2020

The level of neutralizing antibodies to rotaviruses belonging to serotypes 1, 3, and 4 was determined in acute- and convalescent-phase sera from 36 Mexican children with rotaviral diarrhea. Most of the infants who seroconverted fell into one of the following three patterns: single seroconversion to serotype 1; seroconversion to serotypes 1 and 4; or seroconversion to all three serotypes tested. The heterotypic neutralizing antibody responses to rotavirus infections are discussed.
Epidemic septic arthritis caused by Serratia marcescens and associated with a benzalkonium chloride antiseptic
Authors: Nakashima A K , McCarthy M A , Martone W J , Anderson R L
Published: January 2020

During a 6-week period, 10 patients were admitted to a hospital for treatment of knee or shoulder joint infections due to Serratia species. Isolates from eight patients were identified as Serratia marcescens with identical biochemical characteristics and antibiotic susceptibility patterns. Before the onset of infections, all patients had been treated by two orthopedic surgeons who shared an office. Studies revealed that infections were associated with previous joint injections (P = 4.44 X 10(-5] of methylprednisolone and lidocaine. Environmental cultures revealed that a canister of cotton balls soaked in aqueous benzalkonium chloride and two multiple-dose vials of methylprednisolone previously used by office personnel were contaminated with the epidemic strain of S. marcescens. The canister may have served as a potential reservoir for contamination of sterile solutions and equipment used for joint injections, of skin at the injection site, and of hands of personnel. No further cases occurred after the use of aqueous benzalkonium chloride was discontinued.
Survival of Serratia marcescens in benzalkonium chloride and in multiple-dose medication vials: relationship to epidemic septic arthritis
Authors: Nakashima A K , Highsmith A K , Martone W J
Published: January 2020

In an epidemic of septic arthritis due to Serratia marcescens, the intra-articular injection of contaminated methylprednisolone may have played a key role. The epidemic strain was found in used multiple-dose vials of methylprednisolone and in a canister of cotton balls soaked in benzalkonium chloride. The cotton balls had been used for antisepsis and disinfection. Growth characteristics of the epidemic strain of S. marcescens were compared with those of control strains of S. marcescens which had been obtained from unrelated nosocomial outbreaks. The epidemic strain was able to survive in 1:100 dilutions of benzalkonium chloride and was able to grow to greater than 10(5) CFU/ml in multiple-dose vials of methylprednisoline; control strains could not be recovered after 24 h in the same solutions. The preservative in methylprednisolone is gamma-myristyl picolinium chloride, a compound chemically related to benzalkonium chloride. We speculate that the epidemic strain of S. marcescens, which was resistant to benzalkonium chloride, had cross-resistance to gamma-myristyl picolinium chloride. If the cotton balls were used to disinfect the tops of the multiple-dose vials of methylprednisolone, small numbers of organisms subsequently introduced into the solution could have grown to high concentrations.
Candida parapsilosis fungemia associated with parenteral nutrition and contaminated blood pressure transducers
Authors: Weems J J , Chamberland M E , Ward J , Willy M , Padhye A A , Solomon S L
Published: January 2020

During the period September 1983 through May 1985, Candida parapsilosis was isolated from intravascular sites (blood or vascular catheter tips) in 12 patients at a pediatric hospital. Of 205 patients with cultures of any site positive for Candida species, 32 (16%) had cultures positive for C. parapsilosis. In contrast, of 23 patients with intravascular cultures positive for Candida species, 12 (51%) had cultures positive for C. parapsilosis (P less than 0.001, Fisher's exact test). The 12 patients with intravascular cultures positive for C. parapsilosis were more likely to have received central venous nutrition therapy (10 of 12 versus 7 of 23; P less than 0.01, Mantel-Haenzel chi-square test) and had a longer duration of exposure to blood pressure transducers (P less than 0.08, paired t test) than the 23 ward- and age-matched controls. C. parapsilosis was isolated from 11 (32%) of 34 in-use and stored blood pressure transducers. After ethylene oxide sterilization of blood pressure transducers was begun, in-use pressure transducers showed no growth of C. parapsilosis. This study emphasizes the role of C. parapsilosis as a nosocomial pathogen associated with invasive devices and parenteral nutrition; it also emphasizes the importance of adhering to recommended procedures for sterilizing blood pressure transducers.