bluuebunny/crossref_metadata_2025 huggingface dataset:
Detection of soluble Legionella pneumophila antigens in serum and urine specimens by enzyme-linked immunosorbent assay with monoclonal and polyclonal antibodies
Authors: Bibb W F , Arnow P M , Thacker L , McKinney R M
Published: January 2020

Urine and serum specimens from three patients with pneumonia caused by Legionella pneumophila serogroup 1 (Lp1) were tested by enzyme-linked immunosorbent assay (ELISA) for Lp1-soluble antigen. A three-layer direct ELISA with polyclonal antibodies and a four-layer indirect ELISA with both polyclonal and monoclonal antibodies were used. Lp1 antigen was detected in both urine and serum from the three patients. As determined by ELISA, the concentration of antigen was 30- to 100-fold less in serum than in urine collected on the same day. In some instances the indirect ELISA was more sensitive than the direct ELISA, but in others it was less sensitive, depending on the monoclonal antibody used. The subgroup of the infecting Lp1 organism was determined based on antigenic determinants expressed in the urine. This study illustrates the use of serum as well as urine as an antigen reservoir in the laboratory diagnosis of legionellosis by ELISA and the potential for developing more sensitive antigen detection systems by the judicious use of monoclonal antibodies.
Infectivity titration of hemorrhagic fever with renal syndrome virus: use of immune adherence hemagglutination for detection of virus growth
Authors: Matsuura Y , Sugiyama K , Morita C , Morikawa S , Shiga S , Komatsu T , Akao Y , Kitamura T
Published: January 2020

Serial dilutions of hemorrhagic fever with renal syndrome viruses were inoculated into Vero-E6 cells in microplates. After 2 weeks of incubation, infected cells were disrupted by freezing and thawing, and virus antigens were detected by immune adherence hemagglutination. The infectivity titers of the virus as determined by this method were in close agreement with those obtained by the immunofluorescent antigen endpoint method. Then, a neutralization method was established. Japanese hemorrhagic fever with renal syndrome isolates, strains SR-11 and TR-352, were found to be distinct from Hantaan virus, strain 76-118, by the neutralization test.
Evaluation of a commercial enzyme-linked immunosorbent assay for detection of herpes simplex virus antigen
Authors: Warford A L , Levy R A , Rekrut K A
Published: January 2020

A commercial enzyme-linked immunosorbent assay (ELISA) for detection of herpes simplex virus (HSV) antigen in clinical specimens and culture lysates was evaluated. A total of 1,155 specimens and an additional 335 cell culture lysates were tested by ELISA, and results were compared to those obtained by cell culture in primary rabbit kidney, human foreskin, and MRC-5. The sensitivity and specificity of the direct test were 52.5 and 96.9% and those of the culture lysate test were 98.7 and 96.9%, respectively. The sensitivity of the direct ELISA correlated with early cytopathic effect in cell culture and varied with specimen source, ranging from 100% with skin lesions to 40.9% with cervical swabs. Of 60 cervical specimens from asymptomatic individuals, 22 (36.6%) yielded false-positives, which may be due to noninfectious HSV. No reproducible cross-reactions were found with other viruses isolated. The Ortho HSV ELISA was found to be rapid, sensitive, and specific for detection of HSV from cell culture lysates, but it needs reevaluation for direct specimen testing, in particular for screening of asymptomatic obstetrical patients.
Radiometric studies with gas-liquid and thin-layer chromatography for rapid demonstration of hemin dependence and characterization of Mycobacterium haemophilum
Authors: Damato J J , Collins M T
Published: January 2020

Eight isolates of Mycobacterium haemophilum were evaluated by radiometric methods to determine whether this test system could support the growth of these organisms as well as demonstrate their growth requirements for iron complexes such as hemin, ferric ammonium citrate, and blood. In addition, gas-liquid and thin-layer chromatography were evaluated to determine whether these procedures could further differentiate M. haemophilum from other mycobacteria. During the initial 24 to 48 h, there was no significant difference between the radiometric test broths containing iron complexes and control broths without iron supplementation. After 48 h, the test growth index readings rapidly increased, and control broth readings leveled off and declined. The mean growth index reading of the test broths after 6 days of incubation was 100 times that of the controls. The mean incubation time with supplemented 7H10 agar was 17 days. The use of radiometric media resulted in the demonstration of hemin dependence by M. haemophilum significantly earlier than with 7H10 agar. Of the three supplements studied, whole blood provided the greatest growth rate, followed by ferric ammonium citrate and hemin. When 12 species of mycobacteria other than M. haemophilum were radiometrically evaluated, no isolate demonstrated an iron complex requirement. Gas-liquid and thin-layer chromatography procedures were able to rapidly differentiate M. haemophilum from the other 12 Mycobacterium species.
Sensitive enzyme immunoassay for early diagnosis of tuberculous meningitis
Authors: Hernández R , Muñoz O , Guiscafre H
Published: January 2020

Cerebrospinal fluid from patients with tuberculous, pyogenic, and viral meningitis, as well as from appropriate control individuals, were assayed for immunoglobulin G and immunoglobulin M antibody activity to Mycobacterium bovis BCG by an enzyme-linked immunosorbent assay. BCG linked covalently to plastic disks served as the antigen in a classical indirect enzyme-linked immunosorbent assay. A significant difference was found between the tuberculous meningitis group and the nontuberculous meningitis and control groups. All samples from the tuberculous meningitis group gave a positive reaction, and none of the known negative samples gave false-positive reactions. Because of its sensitivity, specificity, and predictive value, this test may be useful in the early diagnosis of tuberculous meningitis.
Measurement of antibodies to varicella-zoster virus in a tropical population by enzyme-linked immunosorbent assay
Authors: Venkitaraman A R , Seigneurin J M , Baccard M , Lenoir G M , John T J
Published: January 2020

We used the recently developed enzyme-linked immunosorbent assay for antibody to varicella-zoster virus to study the prevalence and titers of virus-specific antibody in a south Indian population of 171 individuals 0 to 25 years old. The antibody prevalence rate was less than 15% in individuals under 5 years of age and gradually rose to a maximum of 72% in young adults 15 to 25 years of age. The median age of primary infection was 12.25 years. The geometric mean antibody titers were between 1:80 and 1:160 in the age groups with antibody. These results are different from the pattern of seroepidemiology of varicella-zoster virus infection in temperate countries and indicate that varicella is predominantly a disease of young adults in the population studied.
Use of Directigen and acridine orange for rapid identification of human blood culture isolates
Authors: Flejzor B , Bokkenheuser V D
Published: January 2020

Of 7,871 blood cultures from hospital patients, 22 yielded growth of Streptococcus pneumoniae or Haemophilus influenzae type b. The identities of 19 (86%) of these 22 strains could be verified after 18 to 24 h of incubation by application of the Directigen meningitis test kit to the unheated, uncentrifuged supernatant from the cultures; thus, the turnaround time for these cultures was halved. Growth in 16 (72%) of the Directigen-positive cultures was detected by visual inspection, and that in 3 (14%) of the cultures was detected by acridine orange staining. Growth in the three remaining bottles (14%) was detected by blind subculturing after 18 to 24 h or incubation and, therefore, was delayed by 24 h. The systematic application the acridine orange stain was helpful in 40 (44%) of 91 cases for which macroscopic inspection failed to reveal growth after 24 h of incubation.
Evaluation of the Pneumoslide latex agglutination test for identification of Streptococcus pneumoniae
Authors: Smith S K , Washington J A
Published: January 2020

The Pneumoslide latex agglutination tests was evaluated with 106 strains of Streptococcus pneumoniae and 56 strains representing seven species of viridans streptococci. The Pneumoslide test gave one false-positive and one false-negative reaction. Testing of isolated colonies for solubility in 10% sodium deoxycholate was as accurate but was simpler and less expensive to perform.
Evaluation of three commercial agglutination tests for the identification of Staphylococcus aureus
Authors: Pennell D R , Rott-Petri J A , Kurzynski T A
Published: January 2020

Three commercially available rapid slide agglutination tests for the identification of Staphylococcus aureus were evaluated with 354 recent clinical isolates (165 strains of S. aureus). The test results of two latex agglutination products, SeroSTAT Staph (Scott Laboratories, Inc.) and Staphylatex (American Micro Scan), and one hemagglutination product, Staphyloslide (BBL Microbiology Systems), were compared with the results of the tube coagulase test, which was read at 4 h (4-h tube coagulase test) and, if negative, again after overnight incubation at room temperature (24-h tube coagulase test). Discrepancies between agglutination and tube coagulase identifications were resolved by use of the thermonuclease, mannitol fermentation, and slide coagulase tests. All sensitivities, specificities, predictive values of a positive result, and predictive values of a negative result for the three agglutination tests were at least 98.8% and comparable with the 4-h tube coagulase test. Best results were obtained with the 24-h tube coagulase test, which yielded one false-negative and no false-positive tests. Agglutination identifications may be performed on organisms taken directly from a primary plate when sufficient growth is present. Kit agglutination procedures yield rapid and reliable identifications and are easy to perform. This study also demonstrates the usefulness of the 24-h tube coagulase test.
Acridine orange staining for diagnosis of Mycoplasma bovis infection in cow milk
Authors: Jasper D E , Rosendal S , Barnum D A
Published: January 2020

Mycoplasma organisms were readily recognized in samples of milk or udder secretions from cows with clinical Mycoplasma bovis mastitis when these samples were stained with 0.01% acridine orange at pH 3.0. Samples could be stored at -4 degrees C for several days or subjected to repeated freezing and thawing without loss of staining or fluorescence properties. Use of this procedure in diagnostic laboratories on suspect samples from cows with clinical mastitis could hasten inauguration of control measures against this highly contagious disease by several days; however, definitive diagnosis still requires standard culture methods.
Update and evaluation of the AutoMicrobic yeast identification system
Authors: Land G , Stotler R , Land K , Staneck J
Published: January 2020

The AutoMicrobic system (AMS) Yeast Biochemical Card (Vitek Systems Inc., Hazelwood, Mo.) is a system which has been designed for rapid and automated reporting of yeast identification in the clinical laboratory. Recent improvements have been implemented in the AMS data base to expand and enhance its yeast identification capabilities. These improvements include the addition of seven biotypes, changes in data analysis scheme, and construction of the taxonomic keys. The updated system was compared with the API 20C (Analytab Products, Plainview, N.Y.) yeast identification system and a rapid conventional method, using 1,106 clinical and stock yeast isolates. With these improvements, the AMS Yeast Biochemical Card had a correlation of 98.8% with the API 20C system and 93.4% with the rapid conventional method and significantly increased its capability of identifying Cryptococcus neoformans (98%). The most difficult organisms for the system to identify in 22 to 24 h were Cryptococcus terreus (58%) and Cryptococcus uniguttulatus (73%). The updated AMS not only provided more rapid results which were comparable to the other two systems but gave a substantial savings in set-up and reporting time as well.
Differentiation of Neisseria gonorrhoeae from other Neisseria species by use of the restriction endonuclease HaeIII
Authors: Torres A R , Li M K , Ward D C , Edberg S C
Published: January 2020

We used the restriction endonuclease HaeIII to differentiate Neisseria gonorrhoeae from other Neisseria species and Branhamella catarrhalis. A total of 16 clinical isolates and four American Type Culture Collection strains of N. gonorrhoeae were resistant to HaeIII digestion, whereas 17 isolates and four American Type Culture Collection strains from eight different bacterial species were susceptible. This resistance was not caused by an enzyme inhibitor. We propose that protection of the HaeIII recognition sequence by methylation is the mechanism of resistance since N. gonorrhoeae DNA became susceptible to digestion when passed in Escherichia coli as part of a plasmid clone.
Outbreak of nosocomial urinary tract infections caused by Serratia marcescens
Authors: Okuda T , Endo N , Osada Y , Zen-Yoji H
Published: January 2020

A prolonged outbreak (December 1980 to July 1982) of nosocomial urinary tract infections appeared to be due to strains of Serratia marcescens that were resistant to currently available antibiotics. The serotyping and antibiotic susceptibility patterns suggested a few endemic strains of serotypes O13, O2/3, O12/14, and nontypable strains. These strains were isolated from the urine samples of inpatients with urinary tract infections in the urology ward and in other wards. The strains of O12/14 (gentamicin susceptible) were replaced with those of O2/3 (gentamicin resistant) between June and September 1981, whereas the other serotypes were isolated continuously. They were resistant to sulbenicillin, cefmetazole, gentamicin, and amikacin, and susceptible to micronomicin and of loxacin, a new quinolone antibiotic. Most of them were also resistant to the disinfectant chlorhexidine, which had been used widely for hand washing in the hospital.
Comparative assessment of in vitro inactivation of gentamicin in the presence of carbenicillin by three different gentamicin assay methods
Authors: Ebert S C , Jorgensen J H , Drutz D J , Clementi W A
Published: January 2020

Inactivation of gentamicin (G) is known to occur secondarily to the formation of complexes with certain beta-lactam antibiotics. However, aminoglycosides in the presence of aminoglycoside-beta-lactam complexes may not be recognized uniformly by all assay methods. We tested this hypothesis by using mixtures of G plus carbenicillin (C), with and without the addition of penicillinase, in pooled sera under several in vitro conditions: at 25 and 35 degrees C and at low and high C concentrations. Samples were assayed for G with the EMIT and TDx systems, and a microbiological assay was performed with a strain of Klebsiella pneumoniae resistant to C. In the presence of C (500 micrograms/ml) at 35 degrees C, the initial G concentration of 5 micrograms/ml decreased markedly over 48 h as assessed by all three assay methods. However, significantly greater degradation was noted when samples were measured by microbiological assay and TDx than by EMIT. Differences between assays were less marked when mixtures were studied at a lower temperature and with a lower G to C ratio (5 micrograms of G plus 100 micrograms of C per ml). The addition of penicillinase to the antibiotic mixtures prevented the degradation of G over time when measured by all three assay systems. We concluded (i) that EMIT measures higher serum concentrations of G than do TDx or microbiological assays when complexes of G and C are present and (ii) that the addition of penicillinase to serum samples containing C and G would be effective in preventing G degradation during prolonged (greater than 24-h) periods between the time of sampling and assay.
Biotyping and exoenzyme profiling as an aid in the differentiation of human from bovine group G streptococci
Authors: Clark R B , Berrafati J F , Janda J M , Bottone E J
Published: January 2020

Group G streptococci were isolated from throat and extrapharyngeal cultures from 75 patients during an 18-month period. Of 29 throat isolates, 18 were recovered from patients with pharyngitis, 8 were of unknown significance, and 3 were of questionable etiology. Clinical significance could be ascribed to 13 of 46 extrapharyngeal isolates recovered from wound, urinary tract, blood, and conjunctival cultures. Extrapharyngeal isolates recovered from stool, sputum, and vaginal cultures were considered nonsignificant. A total of 96 group G streptococcal strains (including 21 human and 14 bovine strains from outside sources) were tested for exoenzyme production and subjected to a large battery of biochemical tests. Bovine and human isolates could be distinguished on the basis of trehalose fermentation, litmus milk reduction, and production of beta-D-glucuronidase, hyaluronidase, and fibrinolysin. Eight distinct biotypes could be discerned on the basis of fermentation of trehalose, raffinose, and lactose and esculin hydrolysis. All isolates that fermented raffinose were associated with infection. These results support the concept of two distinctly different epidemiological reservoirs of group G streptococci in humans and bovines.
Sensitivity and specificity of monoclonal antibodies directed against antigenic determinants of Treponema pallidum Nichols in the diagnosis of syphilis
Authors: Norgard M V , Selland C K , Kettman J R , Miller J N
Published: January 2020

Murine anti-Treponema pallidum monoclonal antibodies were employed in studies on sensitivity and specificity of binding to examine their potential for use in the detection of low numbers of pathogenic treponemes present in various body fluids. Monoclonal antibodies were used as a primary antibody source in a solid-phase immunoblot assay system. All monoclonal antibodies assayed were capable of detecting ca. 1.0 X 10(3) to 2.5 X 10(3) treponemes. Of 13 monoclonal antibodies examined, 3 were able to detect 10(3) virulent treponemes, and 1 of these antibodies was able to reveal the presence of as few as 500 organisms. Western blot analyses showed that all anti-T. pallidum monoclonal antibodies exhibiting high sensitivities for the detection of T. pallidum cells were directed against an abundant, 47,000-dalton surface-exposed antigen of the organism (S. A. Jones, K. S. Marchitto, J. N. Miller, and M. V. Norgard, Abstr. Annu. Meet. Am. Soc. Microbiol. 1984, B173, p. 46; K. S. Marchitto, S. A. Jones, and M. V. Norgard, Abstr. Annu. Meet. Am. Soc. Microbiol. 1984, B182, p. 48). Differences in binding properties of the various monoclonal antibodies were most likely a reflection of differential binding affinities or their specificities for different epitopes on the 47,000-dalton surface antigen. With two possible exceptions, the monoclonal antibodies tested reacted specifically with T. pallidum, either purified or found within a high-contaminating tissue background, and not with Treponema phagedenis biotype Reiter, Haemophilus ducreyi, Neisseria gonorrhoeae, herpes simplex virus type 2, or normal rabbit testicular tissue. The high sensitivity and specificity exhibited by these anti-T. pallidum monoclonal antibodies make them excellent candidates for employment in new syphilis or other treponemal diagnostic tests designed to detect very low numbers of pathogenic treponemes in lesion exudates or other body fluids.
Serodiagnosis of typhoid fever by enzyme-linked immunosorbent assay determination of anti-Salmonella typhi lipopolysaccharide antibodies
Authors: Nardiello S , Pizzella T , Russo M , Galanti B
Published: January 2020

Serum samples from 22 patients with proven typhoid fever, 60 febrile nontyphoidal patients, and 120 healthy subjects were tested for immunoglobulin A (IgA), IgG, and IgM anti-Salmonella typhi lipopolysaccharide antibodies by an enzyme-linked immunosorbent assay. The levels of all three classes of immunoglobulin anti-lipopolysaccharide were higher in typhoid patients than in controls; the test for IgM anti-lipopolysaccharide gave the best discrimination between typhoid and nontyphoidal sera. The absorbance values obtained with the enzyme-linked immunosorbent assay for IgM anti-lipopolysaccharide were highly correlated to the titers of anti-O agglutinins. However, the enzyme-linked immunosorbent assay was much more specific than the Widal test, and hence it could be a useful tool for the serological diagnosis of typhoid fever with a single blood sample.
Association of infection caused by Pseudomonas aeruginosa serotype O11 with intravenous abuse of pentazocine mixed with tripelennamine
Authors: Levin M H , Weinstein R A , Nathan C , Selander R K , Ochman H , Kabins S A
Published: January 2020

From July 1979 to June 1983, 25 of 40 intravenous drug addicts with systemic infections had Pseudomonas aeruginosa as the etiological agent; by 1982, P. aeruginosa had replaced Staphylococcus aureus as the most common pathogen. At least 21 of the 25 addicts with P. aeruginosa infection abused pentazocine mixed with tripelennamine (commonly known as T's and blues) compared with 6 of 15 addicts infected with other pathogens (P = 0.006). Of the 25 P. aeruginosa isolates, 23 were of serotype O11. Phenotypic patterns in isolates from addicts and in 22 serotype O11 control isolates from nonaddicts were determined by pyocin and electrophoretic enzyme typing, as well as by susceptibility to heavy metals and antibiotics. Of 25 isolates from addicts, 20 were identical or differed by only one marker, whereas the 22 nonaddict serotype O11 isolates were distributed among 17 distinct phenotypic patterns. We postulate that the emergence of P. aeruginosa as the major cause of deep infection in addicts is a consequence of contamination of their paraphernalia during preparation of pentazocine and tripelennamine for self-injection. The phenotypic similarity among isolates from addicts may reflect acquisition from related environmental sources and an unusual ability of certain serotype O11 strains to survive preparation of the drugs or to be invasive.
Immunoenzymatic assay of anti-diphtheric toxin antibodies in human serum
Authors: Camargo M E , Silveira L , Furuta J A , Oliveira E P , Germek O A
Published: January 2020

An enzyme-linked immunosorbent assay was developed for measuring immunoglobulin G anti-diphtheric toxin antibodies in human serum. The assay was done in plastic plates coated with purified diphtheric toxoid. Since a straight-line relationship was found between logs of extinction values and of antibody concentrations, with a very constant slope, serum titers could be expressed as log10 of the serum dilution corresponding to a definite optical density, such as 0.5. The assay furnished highly reproducible titers on a continuous range, with coefficients of variation less than 10%. Only one or two serum dilutions were usually sufficient for serum titration. To establish correspondence of the enzyme-linked immunosorbent assay titers with biologically determined antitoxin international units, a regression equation was fitted between the respective values for 112 serum samples titrated in both tests. The enzyme-linked immunosorbent assay titer of 2.38 corresponded to an antitoxin titer of 0.01 U, which is considered as the minimal protective level. Simple to perform, economical, and precise, the immunoenzymatic assay seems to be a very practical procedure for seroepidemiological purposes.
Enzyme-linked immunosorbent assay for the diagnosis of cerebral cysticercosis
Authors: Mohammad I N , Heiner D C , Miller B L , Goldberg M A , Kagan I G
Published: January 2020

Central nervous system cysticercosis is common in countries where Taenia solium occurs in pigs and the level of hygiene and sanitation is low. The clinical presentation may include epileptic seizures, focal neurological deficits, hydrocephalus, or aseptic meningitis. The disease is frequently seen in California residents of Hispanic origin. It sometimes occurs in whites from homes that employ Hispanic cooks. Diagnosis is often difficult. Computerized tomography scan and brain biopsy are the most reliable diagnostic procedures, but each has its limitations. We have found that a radioimmunoassay improves our diagnostic capability, and more recently we have adapted this to an enzyme-linked immunosorbent assay that is equally sensitive and specific and, in addition, obviates the need for radioactive materials. Details of the enzyme-linked immunosorbent assay procedure and its application to the diagnosis of central nervous system cysticercosis form the basis of this report.
Comparison of phenol- and heat-killed antigens in the indirect immunofluorescence test for serodiagnosis of Legionella pneumophila group 1 infections
Authors: Pastoris M C , Ciarrocchi S , Di Capua A , Temperanza A M
Published: January 2020

An antigen prepared with agar-grown Legionella pneumophila group 1 killed by 0.5% phenol and suspended in 0.5% yolk sac was examined for use in the indirect immunofluorescence test for legionellosis and compared with a heat-killed antigen. The serological results of the two antigens for single and paired sera agreed well. Morphological and staining characteristics were better for phenol-treated organisms. Electron microscopy observation showed an apparently well-preserved cell surface. The background antibody level among a healthy control population was very low (3.4% with titers of greater than or equal to 16). Sera of patients with gram-negative bacteria infections (Yersinia enterocolytica, Campylobacter jejuni, Salmonella typhimurium, Escherichia coli, Brucella melitensis, Pseudomonas aeruginosa, Mycoplasma pneumoniae, Coxiella burnetti, and Chlamydia psittaci) showed no cross-reactions with the phenol-killed antigen. The data suggest that phenol-killed antigen is sensitive and specific. This antigen is stable for at least 1 year.
Enzyme immunoassay for detection of pneumococcal antigen in cerebrospinal fluid
Authors: Yolken R H , Davis D , Winkelstein J , Russell H , Sippel J E
Published: January 2020

A solid-phase immunoassay utilizing horse antiserum against the C polysaccharide of Streptococcus pneumoniae and biotinylated rabbit antibodies to type-specific pneumococcal polysaccharides was developed to detect pneumococcal antigens in human body fluids and in broth cultures. Pneumococcal antigen could be detected in broth cultures of serotypes of S. pneumoniae containing as little as 10(2) to 10(3) organisms per ml. The assay system detected pneumococcal antigen in all 25 cerebrospinal fluid specimens obtained from patients with documented pneumococcal meningitis. There were no positive reactions noted in specimens from patients infected with Neisseria meningitidis group A or from patients without evidence of bacterial infection. The solid-phase enzyme immunoassay utilizing these reagents is a sensitive and specific assay for the immunodetection of a wide range of pneumococcal antigens.
Patterns of antibodies to staphylococcal DNases in dog sera
Authors: Ness E
Published: January 2020

Sera from clinically healthy dogs and from dogs with a history of skin disease were examined for the presence of antibodies to the DNases of Staphylococcus aureus, Staphylococcus hyicus subsp. hyicus, and Staphylococcus intermedius. The antibodies found most frequently and in the largest amounts were those to the DNase of S. intermedius.
Restriction endonuclease DNA analysis of Leptospira interrogans serovars icterohaemorrhagiae and hebdomadis
Authors: Marshall R B , Winter P J , Yanagawa R
Published: January 2020

Antigenic variants of Leptospira interrogans serovars copenhageni and hebdomadis were examined by bacterial restriction endonuclease DNA analysis with EcoRI, XhoI, SalI, BstEII, and HindIII as the digesting enzymes. The antigenic variants were stable cloned strains which had been cultivated in media containing homologous immune serum. One of the strains examined has been reported elsewhere (R. Yanagawa and J. Takashima, Infect. Immun. 10:1439-1442) as having an antigenic makeup which more closely resembles serovar kremastos than the serovar hebdomadis parent. The closely antigenically related but naturally occurring serovars icterhaemorrhagiae strain RGA and copenhageni strain M20 were examined in parallel. No differences could be shown between the hebdomadis parent and any of its mutants. Serovars copenhageni and icterohaemorrhagiae produced patterns which differed in the high-molecular-weight bands only. The Shibaura parent strain did not differ from copenhageni M20, but the Shibaura M1 strain differed from the other mutants and from icterohaemorrhagiae RGA in its high-molecular-weight bands.
Taxonomic and nomenclatural evaluation of the genera Candida and Torulopsis
Authors: McGinnis M R , Ajello L , Beneke E S , Drouhet E , Goodman N L , Halde C J , Haley L D , Kane J , Land G A , Padhye A A
Published: January 2020

It is concluded that the validly published genera Candida and Torulopsis are taxonomically distinct. The recently proposed merger of these two yeast genera is rejected.
Comparison of Directigen Group A Strep Test with a traditional culture technique for detection of group A beta-hemolytic streptococci
Authors: McCusker J J , McCoy E L , Young C L , Alamares R , Hirsch L S
Published: January 2020

The Directigen Group A Strep Test (DGAST), a new rapid method of detecting group A beta-hemolytic streptococci directly from throat swabs, was compared with a traditional culture technique for the detection of group A beta-hemolytic streptococci. Five hundred oropharyngeal swabs from pediatric and adult patients were cultured and then processed by using the DGAST. Of the 144 specimens positive by culture, 131 were DGAST positive (sensitivity, 90.9%). Of the 356 specimens negative by culture, 353 were DGAST negative (specificity, 99.2%). Twelve of the 13 false-negative DGAST results were from pediatric patients. One hundred isolates of non-group A beta-hemolytic streptococci were recovered, primarily groups C, F, and G. The DGAST is easy to perform, rapid, sensitive, and very specific for detection of group A beta-hemolytic streptococci directly from swabs. Supplementing the DGAST with a culture on a 5% sheep blood agar plate would enhance detection of group A beta-hemolytic streptococci, especially in pediatric patients.
Antigenic identity of Yersinia enterocolitica serotypes O:Tacoma and O21
Authors: Schiemann D A
Published: January 2020

Yersinia enterocolitica serotypes O:Tacoma and O:21 are antigenically identical and include both pathogenic and nonpathogenic types.
Candida pseudotropicalis fungemia and invasive disease in an immunocompromised patient
Authors: Morgan M A , Wilkowske C J , Roberts G D
Published: January 2020

A case of Candida pseudotropicalis fungemia and invasive disease in an immunocompromised patient is reported. Multiple blood cultures taken over a 2-week period were positive, and histopathological slides of postmortem spleen and kidney tissue showed tissue invasion by the organism. The source of the yeast infection was determined to be the urinary tract. This is the first report of C. pseudotropicalis fungemia documented by culture.
Evaluation of the DMS Rapid E system for identification of clinical isolates of the family Enterobacteriaceae
Authors: Keville M W , Doern G V
Published: January 2020

A total of 387 unique clinical isolates of the family Enterobacteriaceae were examined with the new DMS Rapid E gram-negative identification system (DMS Laboratories, Inc., Flemington, N.J.) and the API 20E procedure (Analytab Products, Plainview, N.Y.). Altogether, 376 strains (97.2%) were correctly identified to species level within 4 h with the DMS Rapid E system; 366 strains (94.6%) were correctly identified with the API 20E after overnight incubation.
Preliminary investigation of Mycobacterium tuberculosis biovars
Authors: Roman M C , Sicilia M J
Published: January 2020

A total of 97 Mycobacterium tuberculosis strains were enzymatically evaluated by the APIZYM system. Four enzymatically based groups (biovars) of M. tuberculosis were recognized.
Titration of dengue viruses by immunofluorescence in microtiter plates
Authors: Schoepp R J , Beaty B J
Published: January 2020

A fast, reliable, and inexpensive method was developed for titration of dengue viruses in microtiter plates with an indirect fluorescent-antibody technique. No significant differences were found in median infectious dose endpoints of samples titrated in microtiter plates as compared with titrations in multichambered slides.
Oxygen metabolism in phagocytes of leprotic patients: enhanced endogenous superoxide dismutase activity and hydroxyl radical generation by clofazimine
Authors: Niwa Y , Sakane T , Miyachi Y , Ozaki M
Published: January 2020

We examined the generation of active oxygens (O2-, H2O2, and OH X ) and the superoxide dismutase (SOD) activity of polymorphonuclear leukocytes (PMNs) and monocytes from 14 leprotic patients manifesting a bacillary index above 2.2. Patients with disease of more than 4 years in duration showed significantly enhanced SOD activity and a decrease in O2- and OH X production. The antileprotic agent, clofazimine, significantly increased the generation of OH X in a dose-dependent manner, with a subsequent decrease in H2O2, but had no effect on the SOD activity of the PMNs and monocytes. In medium containing FeSO4 or Fe2+-EDTA, the drug elevated OH X production markedly further. Phagocytic SOD in PMNs and monocytes of leprotic patients was both host and bacillus derived, because the presence of cyanide, to which human-derived cuprozinc SOD is susceptible, did not completely abrogate SOD activity. The difficulty in treating leprosy may be partly ascribable to decreased phagocytic OH X generation, which in leprosy patients is apparently due to the uptake of Hansen bacillus-derived SOD. Clofazimine may be effective in leprosy by chelating Fe2+, with the resultant potentiation of the catalyzing activity of Fe2+ in the Haber-Weiss reaction increasing OH X formation from H2O2.
O:13a,13b, a new pathogenic serotype of Yersinia enterocolitica
Authors: Toma S , Wauters G , McClure H M , Morris G K , Weissfeld A S
Published: January 2020

Forty strains of a new Yersinia enterocolitica serotype isolated in the United States from nonhuman primates and humans were characterized as serotype O:13a,13b. Most of the human strains were isolated from a large multistate outbreak of milkborne enteritis. A common antigenic factor between this new serotype and four previously described Y. enterocolitica (O:7,13; O:18; O:44; and O:44,45) led to recharacterization of the latter as serotypes O:7,13a,13b; O:18,13b; O:44,13a; and O:44,13a,45.
Concentration and identification of Cryptosporidium sp. by use of a parasite concentrator
Authors: Zierdt W S
Published: January 2020

A new disposable plastic tube device and technique for ovum and parasite concentration, with upper and lower chambers separated by a fine screen, was compared with the standard gauze and open-funnel filtration technique as well as with the technique of direct smearing with an acid-fast stain. The new concentrator was distinctly superior to gauze filtration in concentrating Cryptosporidium sp. oocysts. Processing time was reduced. The new technique was less messy and as a closed system was considered to be much safer than gauze filtration.
Comparison of media for isolation of Ureaplasma urealyticum and genital Mycoplasma species
Authors: Fiacco V , Miller M J , Carney E , Martin W J
Published: January 2020

A total of 484 frozen patient specimens originally positive for Ureaplasma urealyticum or Mycoplasma spp. or both were recultured, and the results were compared on the following media: Shepard's A7 agar, modified phenol red-urea, SP-4-urea, modified phenol red-arginine, and SP-4-arginine broths. Of 351 specimens positive for U. urealyticum, 30 (8.5%) were detected only in one or more of the broth media, whereas 117 (33%) were positive only on A7 agar. Separate use of the SP-4-urea broth or modified phenol red-urea broth isolated all but 1 and 2, respectively, of the negative A7 agar cultures. Of the 76 specimens positive for large colony Mycoplasma spp., 58 (76.3%) were not grown on the primary plating (A7) agar. Of 73 broth isolates, 73 (100%) grew in SP-4-arginine broth, and 64 (87.7%) grew in modified phenol red-arginine broth. Modified SP-4 broth appears to be a useful supplement to the A7 plating medium commonly used in the diagnostic laboratory for the isolation of U. urealyticum and Mycoplasma spp.
Comparison of enzyme-multiplied immunoassay technique with fluorescence polarization immunoassay for determination of gentamicin and tobramycin levels in serum
Authors: Pohlod D J , Saravolatz L D , Somerville M M
Published: January 2020

We assayed serum gentamicin and tobramycin specimens by the enzyme multiplied immunoassay technique (Syva EMIT) and the fluorescence polarization immunoassay (Abbott TDx). When interassay and intraassay control samples were evaluated, both methods gave an overall coefficient of variation of less than +/- 10%. Using patient serum samples, we obtained excellent correlation with both methods in the assay of gentamicin (correlation coefficient, 0.985) and tobramycin (correlation coefficient, 0.982).
Stone formation by Ureaplasma urealyticum in human urine and its prevention by urease inhibitors
Authors: Takebe S , Numata A , Kobashi K
Published: January 2020

When Ureaplasma urealyticum T-960 was inoculated into normal human urine (10(8) viable cells per ml of urine), a white precipitate formed, with an increase in pH of the infected urine. This precipitate was identified as a mixture of struvite and whitelockite by analysis of the infrared spectrum. Its formation was completely prevented by the addition of 10 microM N-benzoylphosphotriamide, 20 microM N-isopentenoylphosphotriamide, or 0.5 mM caprylohydroxamic acid without the alkalinization of the urine, and the Ureaplasma color change units were also decreased markedly by these compounds. The apparent concentrations for 50% inhibition by N-benzoylphosphotriamide,N-isopentenolyphosphotriamide, and caprylohydroxamic acid against Ureaplasma urease were 7 nM, 2 nM, and 2.2 microM, respectively. From these results, it seems that stone formation by U. urealyticum is prevented with these compounds, that prevention being directly attributable to the inhibition of urease activity, which causes the death of the cells.
Variability in CO2, O2, and pH levels in blood culture bottles from five different manufacturers
Authors: Welch W D , Porschen R K , Zarifi S Z
Published: January 2020

The CO2, O2, and pH levels of commercially available blood culture bottles with tryptic soy broth medium from five different manufacturers were compared. Ranges of 1.3 to 6.9% for CO2, 1.1 to 6.0% for O2, and pH 6.94 to 7.26 were found. Different venting procedures revealed that blood culture bottles from which the rubber diaphragm was removed equilibrated the most rapidly (24 h) to the atmosphere (10, 5, and 2.5% CO2) they were incubated in. In contrast, blood culture bottles vented with cotton-plugged needles required 48 h to achieve similar CO2 levels in the medium. The ability of these venting procedures to support bacterial growth was confirmed by measuring the growth of a CO2-dependent Escherichia coli isolate in such vented bottles; blood culture bottles that showed rapid atmospheric (5 and 10% CO2) equilibration had the fastest growth curves. Our results suggest that the differences in the recovery of certain microorganism from blood culture bottles may be due in part to the large variability seen in CO2 and O2 concentrations and the use of various venting procedures.
Pneumocystis carinii antigenemia in adults with malignancy, infection, or pulmonary disease
Authors: Pifer L L , Niell H B , Morrison B J , Counce J D , Freeman J M , Woods D R , Neely C L
Published: January 2020

A counterimmunoelectrophoresis test for Pneumocystis carinii antigenemia was employed to assess the extent of subclinical infection or colonization with this agent in adults with infection, pulmonary disease, or malignancy and in healthy homosexual men. Antigenemia was detected in 6 of 208 (3%) of normal controls, 3 of 28 (11%) of patients with pulmonary infection, 3 of 33 (9%) of those with chronic lung disease, 1 of 36 (3%) of patients with lung cancer, 7 of 271 (3%) of afebrile subjects with malignancy, 6 of 19 (32%) of febrile patients with malignancy, 2 of 22 (9%) of those with nonpulmonary infection, and 0 of 21 (0%) of healthy young homosexual men. These data suggest that P. carinii is a common commensal or saprophyte that becomes clinically significant only when host defenses are impaired. Antigenemia may occur intermittently during various disease states in the absence of positive clinical signs and should alert the physician to subacute infection or colonization. Treatment appears advisable when clinical data and counterimmunoelectrophoresis results concur.
Evaluation of the Rapid Strep system for the identification of clinical isolates of Streptococcus species
Authors: Facklam R R , Rhoden D L , Smith P B
Published: January 2020

A total of 247 strains of streptococci isolated from humans were tested for identification in the Rapid Strep system. The identification rates and identification levels were different for each Streptococcus species. Our data indicate that the Rapid Strep system will identify nearly all the beta-hemolytic Streptococcus species if serological procedures are used in conjunction with the rapid physiological procedures. Of the group D streptococci, 98% of the enterococci and 95% of the non-enterococci were correctly identified. Of the commonly occurring viridans species, 85% were correctly identified, but only 10% of the less frequently occurring viridans species were identified. A total of 90% of the Streptococcus pneumoniae and 60% of the Aerococcus strains were correctly identified.
Effect of D-tryptophan on hemolysin production in Vibrio parahaemolyticus
Authors: Cherwonogrodzky J W , Skinner M A , Clark A G
Published: January 2020

Production of the Kanagawa hemolysin by a strain of Vibrio parahaemolyticus isolated from a gastroenteritis patient was found to correlate with the presence in cell lysates of two unidentified compounds, designated X and Y. The two compounds were present in cell lysates of the organism grown in peptone at the optimal pH for hemolysin synthesis but were not present when cell lysates were grown in peptone at a constant pH of 8.0. They were also absent in cells grown in synthetic medium at pH 6.2 without the addition of D-tryptophan, a condition under which hemolysin is not produced. Both X and Y were present intracellularly only from the time that D-tryptophan was added to synthetic medium, a known method of inducing hemolysin synthesis.
New, simple medium for selective recovery of Klebsiella pneumoniae and Klebsiella oxytoca from human feces
Authors: Van Kregten E , Westerdaal N A , Willers J M
Published: January 2020

A culture medium was developed which selectively favored the growth of Klebsiella pneumoniae and Klebsiella oxytoca in Escherichia coli-rich fecal cultures, without the use of antibiotics. The discriminative capacity of this medium was based on the presence of only two carbon sources, citrate and inositol, which can be utilized by nearly all K. pneumoniae and K. oxytoca strains but not by E. coli. The medium consisted of Simmons citrate agar (SCA) with 1% inositol (SCAI). Klebsiella strains from fecal samples subcultured on SCAI grew unhampered as yellow, dome-shaped, often mucoid colonies, whereas E. coli appeared as tiny, watery colonies. Apart from some Enterobacter strains, no other types of bacteria were found to mimic the typical appearance of klebsiellae. Recovery experiments from stool samples revealed a limiting ratio of Klebsiella to E. coli of 1:10(6) or more when samples were plated on SCAI versus ratios of 1:10(2) to 1:10(3) on blood agar or Macconkey agar. Compared with an existing Klebsiella culture method, the combination of SCA and MacConkey-inositol-carbenicillin (MIC) agar, Klebsiella yields with SCAI were not lower than those with the combination of MIC and SCA. Furthermore, the efficiency of the SCAI method was twice that of the latter combination. The SCAI plate could be a valuable tool in studies on the epidemiology of K. pneumoniae and K. oxytoca, for example in nosocomial infections, especially those concerning immunocompromised patients.
Reverse-flow apparatus for enhanced colorimetric detection of bacteriuria
Authors: Wallis C , Melnick J L
Published: January 2020

The reverse-flow apparatus is a new device for enhancing the detection of bacteria in urine. Bacteria are trapped onto a customized filter, and the pigments, crystals, and other interfering substances in the urine pass through the filter and are discarded. The bacteria are backflushed and are recovered as a concentrate, and the concentrate is then processed through the previously described colorimetric bacteriuria detection device. A total of 1,000 urine samples were obtained from randomly selected patients and were cultured on agar. Upon enumeration of the colonies, 160 urine samples were shown to contain more than 10(5) CFU/ml. In the bacteriuria detection device, 150 urine samples could not be processed (pigmenters and cloggers), and of the 850 urine samples processed, 127 were culture positive for 10(5) CFU/ml or greater, and 150 urine samples contained between 10(4) and 10(5) CFU/ml. At 10(5) CFU/ml, there were 140 false-positives and 14 false-negatives. When duplicate urine samples were processed through and concentrated by our new reverse-flow apparatus, all samples, including the above pigmenters and cloggers, could be tested in the bacteriuria detection device. The 150 unprocessable samples described above yielded 33 additional bacteria-positive urines, 23 at the 10(5)-CFU/ml cutoff and 10 at the 10(4)-to-10(5)-CFU/ml cutoff. There were 105 false-positives at 10(5) CFU/ml and only 2 false-negatives at the same level of bacteria. At 10(4) to 10(5) CFU/ml there was only 1% false-positive and 4% false-negative. The reverse-flow apparatus allows greater specificity and sensitivity in the rapid bacteriuria test. Urine containing 10(4) CFU/ml or more can now be detected with a 96% sensitivity in a total processing time of less than 2 min.
Rapid diagnosis of chlamydial infections with the MicroTrak direct test
Authors: Uyeda C T , Welborn P , Ellison-Birang N , Shunk K , Tsaouse B
Published: January 2020

A direct test on clinical specimens, using fluorescein-labeled monoclonal antibodies, for Chlamydia trachomatis (MicroTrak [Syva Co.]) was evaluated for the rapid diagnosis of chlamydial infections. Asymptomatic females attending pregnancy or planned parenthood clinics were tested by the direct test and by a cell culture method. Of 401 paired, endocervical specimens, 398 (99.3%) gave identical direct and culture results. The overall sensitivity of the direct test was 96.3% (26 of 27), and the specificity was 99.5% (372 of 374) as compared with that of culture. More than four-fifths of the direct smears were read within ca. 2 min. In this study population, the performance of the direct specimen test was comparable to that of cell culture methods. Rapid turnaround time and elimination of the need for cell culture make the direct test a practical method for the specific diagnosis of chlamydial infections.
DNA hybridization technique to detect Shigella species and enteroinvasive escherichia coli
Authors: Boileau C R , d'Hauteville H M , Sansonetti P J
Published: January 2020

A DNA hybridization method for the detection of Shigella species and enteroinvasive Escherichia coli is described. It is based upon the high degree of homology shared by the virulence plasmids present in all pathogenic strains. After 32P labeling, a 17-kilobase EcoRI restriction fragment of a virulence plasmid belonging to Shigella flexneri serotype 5 was used as a probe to detect Shigella species and enteroinvasive E. coli in isolated colonies. This method proved highly specific as well as sensitive and should be particularly useful for the characterization of atypical isolates and for large-scale epidemiological studies in endemic areas.