bluuebunny/crossref_metadata_2025 huggingface dataset:
Ureolytic Escherichia coli of human origin: serological, epidemiological, and genetic analysis
Authors: Wachsmuth I K , Davis B R , Allen S D
Published: January 2020

Forty-five strains of ureolytic Escherichia coli of human origin, isolated in the United States between 1956 and 1977, were characterized by geographical distribution, site of infection, serotype, resistance to antibiotics, and biochemical reactions. All strains were studied for the ability to generate clones of nonureolytic E. coli (segregants), and a subset of these were selected for plasmid analysis and a variety of bacterial matings. There did not appear to be a common geographical distribution, serotype, antibiogram, or other aberrant biochemical reactions other than the hydrolysis of urea among these strains. The predominance of urinary tract isolates (46.7% total) may reflect a relationship between urea hydrolysis and pathogenesis at this site. Ten of the strains (22.2%) did segregate nonureolytic E. coli colonies, and all possessed at least one common plasmid species with a molecular weight of about 65 X 10(6). Only strain 1138-77 serotype O16:H6 conjugally transfered the ability to hydrolyze urea, ferment sucrose, and resist inhibition by sulfadiazide simultaneously. The resulting, recombination-deficient E. coli K-12 tranconjugant was found to possess a plasmid with a molecular weight of about 80 X 10(6) to 90 X 10(6).
More sensitive test agar for detection of dextranase-producing oral streptococci and identification of two glucan synthesis-defective dextranase mutants of Streptococcus mutans 6715
Authors: Donkersloot J A , Harr R J
Published: January 2020

A more sensitive test agar was developed to detect oral microbes with relatively low dextranase activity and to identify dextranase-negative mutants. Several oral streptococci that had previously been scored as dextranase negative readily decolorized the new, blue dextran-containing medium. To assess whether dextranase plays a role in glucan synthesis by oral streptococci, various glucan synthesis-defective mutants were tested for dextranase activity on the new medium. Mutants 4 and 27, which do not cause smooth-surface caries and which synthesize more soluble glucan than their parent, Streptococcus mutans 6715-13, were markedly deficient in these dextranase activity tests.
Meningitis due to Haemophilus influenzae type e biotype 4
Authors: Shishido H , Matsumoto K
Published: January 2020

Haemophilus influenzae type e biotype 4 was isolated from the cerebrospinal fluid of a 16-month-old child with meningitis. This is the first isolation, from a case of meningitis, of this organism that has been biotyped.
Cellular fatty acid composition of Francisella tularensis
Authors: Jantzen E , Berdal B P , Omland T
Published: January 2020

Several unusual fatty acids characterized strains of Francisella tularensis. Long-chain (C20-C26) acids and the hydroxy acids 2-hydroxy-decanoate, 3-hydroxy-hexadecanoate, and 3-hydroxy-octadecanoate appeared to be of special diagnostic value.
Enzyme-linked immunosorbent assays adapted for serotyping of human rotavirus strains
Authors: Zissis G , Lambert J P
Published: January 2020

Five enzyme-linked immunosorbent assay systems were adapted for serotyping human rotavirus strains and were compared with a sensitive complement fixation test in terms of specificity and sensitivity. The assays differed mainly with regard to the antibody systems involved in the double sandwich. Serotype differentiation of 34 rotavirus strains was achieved by determining a neutralization endpoint titer, either with a constant antiserum-varying antigen dilution method or vice versa. The procedure which proved to be highly specific and sensitive was one with two type-specific hyperimmune sera (enzyme-linked immunosorbent assay system 5) instead of only one, as in the four other systems.
Rapid differentiation of the major causative agents of bacterial meningitis by use of frequency-pulsed electron capture gas-liquid chromatography: analysis of amines
Authors: Brooks J B , Kellogg D S , Shepherd M E , Alley C C
Published: January 2020

The major causative agents of bacterial meningitis (Haemophilus influenzae serogroup B, Neisseria meningitidis serogroups B and C, Klebsiella pneumoniae, Steptococcus pneumoniae, and two types of Escherichia coli) were cultured in a chemically defined medium, and selected strains were further studied in Todd-Hewitt medium. After acidic extraction of the spent media with chloroform, a basic extraction was made with chloroform to obtain amines. A third extraction was performed on re-acidified Todd-Hewitt medium with ethyl ether to obtain hydroxyacids. The extracts were derivatized with heptafluorobutyric anhydride-ethanol to form electron-capturing derivatives, and the derivatives were analyzed on a frequency-pulsed electron capture gas-liquid chromatograph (FPEC-GLC) equipped with a PEP-2 computer. The data obtained from the study showed that amines were produced by these organisms that formed characteristic patterns. Different serotypes of K. pneumoniae and the two serogroups of N. meningitidis produced different types of FPEC-GLC profiles within serotypes. E. coli produced several hydroxy acids on Todd-Hewitt medium that made it unique among the organisms studied. The methods used are practical and the techniques have potential for use in clinical laboratories and hospitals as a valuable aid for the rapid identification of the major causative agents of bacterial meningitis.
Direct immunofluorescent detection of Legionella pneumophila in respiratory specimens
Authors: Winn W C , Cherry W B , Frank R O , Casey C A , Broome C V
Published: January 2020

Respiratory secretions from patients with clinically suspected Legionnaires pneumonia were examined by direc immunofluorescent tests at the Medical Center Hospital of Vermont and at the Center for Disease Control. No fluorescent bacteria were found by either laboratory in eight specimens from eight patients who were seronegative. Twenty specimens were obtained from seven patients who had serologically confirmed Legionnaires disease. Four of the seven cases were identified at the Medical Center Hospital of Vermont, and six of the seven were identified at the Center for Disease Control. Of 20 specimens, 8 were positive at the Center for Disease Control (six or more bacilli per slide), and 7 specimens were suspicious (one to five bacilli per slide); at the Medical Center Hospital of Vermont, 4 of 20 specimens were positive, and 2 were suspicious. The inclusion of a rhodamine-conjugated counterstain at the Center for Disease Control facilitated the examination and may have improved the sensitivity. Smears from transtracheal aspirates, bronchoscopic aspirates, transcutaneous lung aspirates, pleural fluids, and tracheal aspirate-expectorated sputum produced positive results. Several specimens contained fluorescing bacilli when stained for serogroup 2 as well as serogroup 1, perhaps reflecting the presence of cross-reacting antigens in vivo.
Variable susceptibility of mice to group B coxsackievirus infections
Authors: Minnich L L , Ray C G
Published: January 2020

Laboratory strains of group B coxsackievirus serotypes 1 to 6 were inoculated intraperitoneally into newborn mice of differing genetic backgrouns. Of the four genetic strains investigated, C3H mice appeared to be resistant to all six serotypes, whereas BALB/c mice were most susceptible. Swiss mice and a random-bred Swiss strain (COH) were intermediate in susceptibility. The findings underscore the fact that clinical isolation attempts and experimental studies involving group B coxsackieviruses must take into account both the virus strain used and the genetic background of the host. For clinical isolation of these viruses, the BALB/c mouse may be the most suitable of th strains tested.
Streptococcus zooepidemicus (group C) pneumonia in a human
Authors: Rose H D , Allen J R , Witte G
Published: January 2020

Lancefield group C streptococcal pneumonia appeared in a previously healthy young adult. The patient apparently acquired the infection while caring for her sick horse, and experienced a gradual onset of the illness. There was rapid accumulation of pleural fluid and empyema requiring open drainage. Group C pneumonia cannot be distinguished from classic group A pneumonia on clinical grounds. Beta-hemolytic streptococci isolated from sputum, transtracheal aspirates, pleural fluid, or blood of patients with pneumonia should be grouped by the precipitin method of Lancefield or one of its more rapid modifications.
Differentiation of cytomegalovirus antigens by their reactivity with various classes of human antibodies in the indirect fluorescent antibody test
Authors: Riggs J L , Cremer N E
Published: January 2020

Human sera containing immunoglobulin G (IgG), IgA, and IgM antibodies were tested by immunofluorescence for reactivity with cytomegalovirus-infected cell cultures and with early antigens of cytomegalovirus produced by treating the infected cultures with either bromodeoxyuridine or cytosine arabinoside. IgG antibody but not IgM antibody reacted with early antigens produced in bromodeoxyuridine-treated infected cultures. This observation on a small sample of sera suggested that a positive IgM reaction with an infected, nontreated culture and a negative reaction with a bromodeoxyuridine-treated infected culture may indicate a positive specific IgM reaction for cytomegalovirus, even in the presence of IgM rhematoid factor. The hyothesis requires further testing. The different classes of antibody did not all react or did not react to the same extent with early antigens produced in infected cells blocked with cytosine arabinoside or bromodeoxyuridine. This observation indicates that different antigens were being produced as a result of the two treatments.
Slide agglutination test for serogrouping Legionella pneumophila and atypical Legionella-like organisms
Authors: Wilkinson H W , Fikes B J
Published: January 2020

A simple, inexpensive slide agglutination test correctly identified the serogroup to which 38 Legionella pneumophilia strains belonged, and distinguished them from two atypical, Legionella-like organisms.
Serotypes of group B streptococci and their relation to hyaluronidase production and hydrolysis of salicin
Authors: Kjems E , Perch B , Henrichsen J
Published: January 2020

A total of 252 strains of group B streptococci were serotyped and examined for their ability to ferment lactose (lac+), to hydrolyze salicin (sal+), and to produce hyaluronidase (hy+). Of these strains, 67 had been isolated from bacteremia and meningitis in infants less than 2 months old. Eighty-one strains were isolated from bacteremia and meningitis in adults, and 104 strains were from various other infections. Type III was the most common in neonatal disease, especially if isolates from cases of bacteremia in infants less than 10 days of age were not included. Only 6% of the strains were lac+. Sal+/hy+ strains were never type III, but 91% of the strains belonging to the other serotypes were sal+/hy/. Results showed that 81% of the sal+/hy- strains and 95% of the sal-/hy+ strains were type III, and sal-/hy+ strains were more than twice as frequent as sal+/hy- strains in serious neonatal infections, in contrast to the other two disease groups, in which the opposite was found to be the case. These reactions may be used as additional markers in epidemiological studies.
Enzyme immunoassay for measurement of antibodies to herpes simplex virus infection: comparison with complement fixation, immunofluorescent-antibody, and neutralization techniques
Authors: Denoyel G A , Gaspar A , Nouyrigat C
Published: January 2020

An enzyme immunoassay (EIA) was developed for detecting antibody to herpes simplex virus, and the results were compared with those of complement fixation, indirect immunofluorescent-antibody, and plaque reduction neutralization tests. Test sera showed very little nonspecific reactivity even at a starting dilution as low as 1:10. EIA results showed excellent correlation with results obtained by the neutralization test, with an average gain in sensitivity of 1.65. EIA proved very useful in detecting current herpes simplex virus infection, and antibody appeared in all cases soon after clinical onset. EIA appears to be a rapid, sensitive, and specific method for routine demonstration of herpes simplex virus antibody in a clinical setting.
Some characteristics of a new multiple-channel photometer for through-the-plate reading of microplates to be used in enzyme-linked immunosorbent assay
Authors: Ruitenberg E J , Sekhuis V M , Brosi B J
Published: January 2020

The performance of a prototype of a now commercially available multiple-channel photometer for high-speed reading of microplates to be used in the enzyme-linked immunosorbent assay was evaluated. For this purpose the extinction of a stable test liquid dispensed in flat-bottomed polystyrene microplates was measured, varying the test volume and the optical density. From the results obtained for dilutions of a single, biolgoically inactive material we concluded that the photometric inaccuracy is negligible when performing enzyme-linked immunosorbent assay with biologically active samples.
Detection of Pneumococcal Capsular polysaccharide antigens by latex agglutination, counterimmunoelectrophoresis, and radioimmunoassay in middle ear exudates in acute otitis media
Authors: Leinonen M K
Published: January 2020

The presence of pneumococcal antigen in middle ear exudates during acute otitis media was studied by latex agglutination and counterimmunoelectrophoresis. The positive antigen findings were confirmed by radioimmunoassay. Latex agglutination gave a positive result in 63% and counterimmunoelectrophoresis in 76% of samples that grew Streptococcus pneumoniae. The methods were complementary; the antigen was detected by one or both of the methods in 88% of these samples. Pneumococcal antigen was further detected in 15% of samples that grew other otitis pathogens and in 33% of samples in which no pathogenic bacteria were recovered by culture. The distribution of pneumococcal serotypes found by immunochemical methods only corresponded to that found by culture.
Clinical and laboratory characteristics of Achromobacter xylosoxidans infection
Authors: Igra-Siegman Y , Chmel H , Cobbs C
Published: January 2020

Achromobacter xylosoxidans was isolated from six patients. The organism causes opportunistic infections in patients who are compromised. A. xylosoxidans is a catalase- and oxidase-positive, motile, gram-negative rod that oxidizes xylose and glucose. The organism exists in a water environment and may be confused with Pseudomonas species. Unlike pseudomonas, achromobacter has peritrichous flagella. The clinical and laboratory characteristics of A. xylosoxidans are presented.
Evaluation of a safranin-O-stained antigen microagglutination test for francisella tularensis antibodies
Authors: Brown S L , McKinney F T , Klein G C , Jones W L
Published: January 2020

A microagglutination test for Francisella tularensis, with 0.025-ml amounts of diluted sera and 0.025-ml amounts of safranin-O-stained antigen in U-bottom microtitration plates, was compared with a tube agglutination test by using 137 sera. There was 86.3% agreement (+/- 1 dilution variation) between the microagglutination results and the tube agglutination results for sera with tube agglutination titers of greater than or equal to 20. There was 100% agreement (+/- 1 dilution variation) for sera with titers of less than 20. The advantages of the microagglutination test are: (i) it requires fewer man hours to perform; (ii) it requires only one-twentieth of the amount of antigen; and (iii) it is easier to read.
Evaluation of the phadebact gonococcus test, a coagglutination procedure for confirmation of Neisseria gonorrhoeae
Authors: Lewis J S , Martin J E
Published: January 2020

Rapid and accurate immunological confirmation of presumptively positive gonococci could be facilitated with the Phadebact Gonococcus Test, a slide coagglutination procedure. The test was compared with carbohydrate utilization and fluorescent-antibody tests on 235 clinical isolates. With the coagglutination procedure, 97.1% of the isolates were identified as compared with 93.1% by carbohydrate utilization and 98.7% by fluorescent antibody. The Phadebact test was highly specific, showing no cross-reactions with 55 other Neisseria species or with 50 miscellaneous organisms occasionally found growing on selective culture media. Because of its high sensitivity and specificity, ease of performance, and ability to provide results in 2 to 3 min, this procedure provides a suitable alternative to the carbohydrate utilization and fluorescent-antibody tests for confirmation of N. gonorrhoeae.
Nosocomial multiply resistant Providencia stuartii: a long-term outbreak with multiple biotypes and serotypes at one hospital
Authors: Kocka F E , Srinivasan S , Mowjood M , Kantor H S
Published: January 2020

A long-term outbreak of urinary tract-associated multiply resistant Providencia stuartii occurred in a large medical facility that included a 513-bed chronic care unit. The unique characteristics of this outbreak were that from within a single medical facility, P. stuartii with multiple serotypes, biotypes, and antibiograms could be identified. The organisms isolated had five different biotypes, seven different antibiograms, and two major serotypes. All of the organisms were susceptible to amikacin, cefamandole, and cefoxitin. Application of standard infection control measures impeded the spread of this outbreak, and it slowly terminated 16 months later.
Branhamella (Neisseria) catarrhalis: criteria for laboratory identification
Authors: Doern G V , Morse S A
Published: January 2020

Eleven clinically significant isolates of Branhamella catarrhalis grew well on modified Thayer-Martin medium and produced beta-lactamase, but did not grow on nutrient agar at 22 degrees C. Minimum inhibitory concentrations of vancomycin, colistin, and trimethoprim were found to be higher than the concentrations of these antibiotics in modified Thayer-Martin medium. The criteria necessary for laboratory identification of B. catarrhalis are discussed.
Evaluation of the exoantigen test for identification of Histoplasma species and Coccidioides immitis cultures
Authors: DiSalvo A F , Sekhon A S , Land G A , Fleming W H
Published: January 2020

Recently it was demonstrated that certain fungal pathogens could be rapidly and accurately identified on the basis of their exoantigens. Mycelial-form cultures of the Histoplasma species consistently appear to produce either H or M antigens, or both, whereas cultures of Coccidioides immitis produce tube precipitinogen, heat-labile precipitinogen, or heat-labile F antigens. Three laboratories each evaluated 48 cultures by the exoantigen procedure for the identification of Histoplasma spp. and C. immitis. One hundred forty-four cultures were tested, and 143 (99.3%) were correctly identified as Histoplama spp. or C. immitis, or neither. The simple and rapid exoantigen test appears to be a sensitive and specific method for identification of these fungi.
Meningitis caused by maltose-negative variant of Neisseria meningitidis
Authors: Granato P A , Howard R , Wilkinson B , Laser J
Published: January 2020

A maltose-negative variant of Neisseria meningitidis, Slaterus Y, was recovered from a patient with meningitis. A report of the case is presented and the medical-legal significance of such an isolate is briefly discussed.
Evaluation of acridine orange stain for detection of microorganisms in blood cultures
Authors: McCarthy L R , Senne J E
Published: January 2020

A pH 4.0 buffered solution of the fluorochrome acridine orange was used to stain samples of 2,704 blood cultures that failed to yield visible evidence of growth after 1 day of incubation. Results obtained by the staining method were compared with those obtained by aerobic and anaerobic subcultures simultaneously performed upon the same cultures. Of the 109 culture-positive blood specimens initially detected by the acridine orange and the subculture methods, 85 (78%) were detected by both acridine orange and subcultures techniques, 14 (12.8%) were detected by subculture alone, and 10 (9.2%) were detected by acridine orange alone. The differences between the subculture and acridine orange methods were not found to be statistically significant (P less than 0.1). The acridine orange method represents a rapid and inexpensive alternative to conventional subculture techniques for the detection of bacteria in blood cultures that fail to yield visible evidence of growth after 1 day of incubation.
Comparison of three blood-clotting substances in Staphylococcus aureus strains
Authors: Yoshida K , Takahashi M , Haga K , Kono E , Kushiro H , Ito S
Published: January 2020

Besides the two well-known blood-clotting substances, coagulase and clumping factor, a third one has been identified from the staphylococci which is a cell surface polysaccharide, is alkali stable, and induces compact-colony formation in serum soft agar. Using some 97 clinical strains of Staphylococcus aureus, we found that in production and activity the substances were distinctly different.
Use of preserved organisms for individual test-use quality control of bacterial typing antisera
Authors: Wright D N , Welch D F , Matsen J M
Published: January 2020

Bacterial antigens representing 14 of the most common clinical isolates requiring serological confirmation for identification were prepared. These antigens were stable for periods in excess of 5 months, readily available, and sero-specific. Use of these antigens for quality control of bacterial typing antisera increased the accuracy, reduced the technician time, and obviated the delay which otherwise occurred while stock isolates were subcultured to provide a sero-specific control for this procedure.
Enzyme-linked immunosorbent assay for mumps and parainfluenza type 1 immunoglobulin G and immunoglobulin M antibodies
Authors: Ukkonen P , Väisänen O , Penttinen K
Published: January 2020

A solid-phase enzyme-linked immunosorbent assay (ELISA) for detection of mumps and parainfluenza type 1 antibodies (immunoglobulin G [IgG] and IgM classes) is described and compared with the conventional complement fixation (CF) test. A highly positive correlation was found between mumps IgG ELISA and the mumps CF test, whereas parainfluenza type 1 IgG ELISA had only a moderate positive correlation with the respective CF test. Mumps IgM antibodies could be demonstrated in all patients with serologically verified and clinically typical (parotitis, meningitis, or orchitis) mumps virus infection, but not in patients with rises in parainfluenza CF titers. Mumps IgM was already present in the acute-phase sera if they were not taken during the first 2 days after onset of disease. Mumps IgM was also found in some paired sera that were taken too late to demonstrate any significant increase in the antibody titers by CF. Therefore, mumps IgM ELISA provides an improvement over the conventional laboratory diagnosis of mumps infection, since the measurement of specific IgM antibodies in a single serum by ELISA is diagnostic, rather than the identification of a fourfold or greater rise in CF antibody titer. An unexpected finding was that parainfluenza type 1 IgM antibodies could not be demonstrated by ELISA in paired sera with rises in parainfluenza CF titers, suggesting a different antibody response from that occurring in mumps infection.
Evaluation of cerebrospinal fluid lactic acid levels as an aid in differential diagnosis of bacterial and viral meningitis in adults
Authors: Lannigan R , MacDonald M A , Marrie T J , Haldane E V
Published: January 2020

The level of lactic acid in cerebrospinal fluid has been suggested as a useful diagnostic parameter to differentiate between bacterial and viral meningitis, especially in patients partially treated before admission to hospital. A concentration of greater than or equal to 35 mg/dl, determined by either gas-liquid chromatography or an enzymatic method, has been considered in several studies to provide definite evidence of meningitis of bacterial origin, whereas a lower level indicates no bacterial involvement. Over the past 18 months, we have analyzed by the enzymatic method the lactate level in 493 spinal fluids submitted from 434 adult patients with various conditions involving the central nervous system. Fifty fluids had a lactate level of greater than 35 mg/dl, of which 19 were cases of infective meningitis of varying etiology. The 435 specimens with lactate levels within the range considered normal included three cases of infective meningitis, of which two were cryptococcal and one was bacterial. In this adult study, the lactate level in the cerebrospinal fluid did not provide unequivocal evidence of bacterial infection and did not provide assistance to any greater degree than the standard parameters of leukocyte count, protein, and glucose contents in the differential diagnosis of bacterial meningitis from that of any other etiology.
Comparative evaluation of the tube and microdilution Limulus lysate techniques for rapid presumptive diagnosis of gonococcal urethritis in men
Authors: Prior R B , Spagna V A
Published: January 2020

Eighty-one men with exudative urethritis were evaluated on initial visit for gonococcal urethritis by using the standard tube and newly developed microdilution Limulus amoebocyte lysate techniques. Serial dilutions of clinical specimens ranging from 1:100 to 1:102,400 were each tested, and results correlated with Gram stain and culture. Overall accuracy for predicting culture results was 98% for a dilution of 1:200 and 99% for a dilution of 1:400 for the tube and microdilution techniques, respectively. The microdilution technique predicted culture results in 98% of cases for dilutions ranging from 1:400 to 1:1,600, whereas the tube technique was as accurate for dilutions of only 1:100 and 1:200. The microdilution Limulus amoebocyte lysate technique was a rapid, reliable, sensitive, and economical diagnostic aid in the initial evaluation of exudative urethritis in men.
Virion envelope glycoproteins as epidermiological markers of Venezuelan encephalitis virus isolates
Authors: Wiebe M E , Scherer W F
Published: January 2020

Virion polypeptide compositions of 26 isolates of Venezuelan encephalitis virus were analyzed by a reproducible and comparative technique of discontinuous sodium dodecyl sulfate-polyacrylamide slab gel electrophoresis. Although the molecular weight of the core polypeptide for each isolate was 36,000, numbers and molecular weights of envelope glycoproteins were heterogeneous. Isolates associated with human, but not equine, disease usually had two glycoproteins of 50,000 to 51,000 and 51,000 to 55,000 molecular weight, whereas isolates associated with both human and equine disease usually had an additional, third polypeptide band of either 45,000 to 46,000 or 56,000 to 58,000 molecular weight. The former isolates were in hemagglutination inhibition subtypes I-D, I-E, III, or IV, and the latter were in subtypes I-A, I-B, I-C, or II. Thus virion envelope glycoproteins should be useful markers of Venezuelan encephalitis virus isolates in epidemiological investigations.
Inactivation of mycoplasma in serum with binary ethyleneimine
Authors: Christianson G G , Pemberton J R , Koski T A
Published: January 2020

A method of inactivating mycoplasma contaminants in sera by using binary ethyleneimine was tried. When used at the concentration recommended for inactivating viruses, 0.001 M, binary ethyleneimine inactivated only two of five mycoplasma species. Even at a concentration of 0.01 M, the compound did not consistently inactivate all mycoplasmas.
Use of Moore swabs for isolating Vibrio cholerae from sewage
Authors: Barrett T J , Blake P A , Morris G K , Puhr N D , Bradford H B , Wells J G
Published: January 2020

The Moore swab method was shown to be a practical and sensitive technique for the isolation of Vibrio cholerae from sewage. In each of three instances in which cholera patients lived in homes connected to municipal sewers, V. cholerae was isolated from the community sewage plant intake at the time of the patients illness. Sewer systems became negative within 1 day after patients were treated with tetracycline. Sewer surveillance using the Moore swab also found evidence of infections occurring in areas where surveillance of diarrheal illness failed to detect cholera. Culturing community sewage by the Moore swab method proved to be an economical and effective way of determining areas where V. cholerae infections were occurring.
Suppression of Chlamydia trachomatis inclusion formation by fetal calf serum in cycloheximide-treated McCoy cells
Authors: Evans R T
Published: January 2020

A batch of fetal calf serum was encountered which suppressed the number of Chlamydia trachomatis inclusions seen when it was used in conjunction with cycloheximide-treated McCoy cells. The batch of serum did not affect the number of inclusions detected in irradiated or untreated McCoy cells.
Hippurate hydrolysis by Campylobacter fetus
Authors: Harvey S M
Published: January 2020

An additional method for differentiating between Campylobacter fetus subsp. jejuni and C. fetus subsp. intestinalis is reported. Strains of C. fetus subsp. jejuni (18/20) were shown to hydrolyze hippurate in the 2-h rapid test, whereas strains of C. fetus subsp. intestinalis did not.
Biochemical and cultural characteristics of invasive Escherichia coli
Authors: Silva R M , Toledo M R , Trabulsi L R
Published: January 2020

The biochemical characteristics of 97 invasive Escherichia coli strains of different O serogroups were studied. Considered as a group, the behavior of the strains was quite variable. However, none of them decarboxylated lysine and all but seven strains, belonging to the O124 serogroup, were nonmotile. The growth of 25 strains obtained on MacConkey, salmonella-shigella, xylose-lysine-desoxycholate, and Hektoen enteric agars was compared. MacConkey and Hektoen enteric agars yielded the highest average growth for these strains, whereas salmonella-shigella agar had the lowest average counts.
Capacity of staphylococci to grow in the presence of ovotransferrin or CrCl3 as a character of potential pathogenicity
Authors: Valenti P , De Stasio A , Seganti L , Mastromarino P , Sinibaldi L , Orsi N
Published: January 2020

A total of 150 strains of staphylococci, clinically isolated, were tested for sensitivity to ovotransferrin (conalbumin). Among these, all the 50 coagulase-positive, mannitol-positive, and deoxyribonuclease-positive staphylococci appeared to be resistant to conalbumin, i.e., capable of growing in the presence of this transferrin. Among the other 100 strains, which were not classified as S. aureus, some appeared to be resistant and some were sensitive. The different behavior toward conalbumin is related to varying degrees of efficiency of the bacterial iron transport systems and, to test this, a simple method can be used, based on the addition of CrCl3 to the culture medium. The precipitation of iron produced by chromium salts has an effect on the growth of staphylococci similar to that produced by conalbumin and reveals the differences in the iron transport systems which occur in the genus Staphylococcus.
Hepatitis B e antibody determination: comparison and evaluation of four different methods
Authors: Aldershvile J , Caspani B , Frösner G G
Published: January 2020

A radioimmunological neutralization assay for the determination of hepatitis B e antibody is described. The method is compared with a blocking and a competitive assay and with immunodiffusion. The neutralization assay proved to be the most sensitive method, and results obtained by this method were reproduced most easily. The frequency of nonspecific results may be up to 1% of the sera tested. Among patients with acute type B hepatitis, e antibody was found regularly soon after the clearance of hepatitis B e antigen by using the neutralization assay, whereas this antibody was found on the average several weeks later and in a lower percentage of patients by using the other methods. It is concluded that at present the neutralization assay is the method of choice.
High-catalase strains of Mycobacterium kansasii isolated from water in Texas
Authors: Steadham J E
Published: January 2020

Isolation techniques with membrane-filtered potable water samples resulted in the isolation of potentially pathogenic high-catalase strains of Mycobacterium kansasii from 8 of 19 representative outlets in a small central Texas town. Mycobacterium gordonae was isolated from all samples, and Mycobacterium fortuitum was isolated from two samples. Data on chlorine levels are presented along with a possible explanation for the unusually high numbers of mycobacteria in these potable water samples. Findings suggest that water is a source of M. kansasii and may be an important link in the epidemiological picture of the disease.
Characteristics of Bacteroides asaccharolyticus from dental plaques of beagle dogs
Authors: Syed S A
Published: January 2020

Gram-negative, non-saccharolytic, brown- or black-pigment-forming, nonmotile anaerboic coccobacilli, capable of decomposing hydrogen peroxide and identified as Bacteroides asaccharolyticus (B. melaninogenicus subsp. asaccharolyticus), were isolated from the supra- and subgingival plaques of beagle dogs with gingivitis or periodontitis. The organisms remained viable for many hours in an aerobic atmosphere as evidenced by their ability to grow subsequently in an anaerobic environment. They also grew well on agar media that were not reduced before use. Although blood was required for pigmentation of colonies, organisms grew on media that lacked hemin, menadione, blood, or reducing compounds. Increased oxygen tolerance, catalase activity, and different nutritional requirements differentiate these organisms from strains of B. asaccharolyticus isolated from humans.
Reproducibility of serological titers
Authors: Wood R J , Durham T M
Published: January 2020

Serologists are making increasing use of the term "reproducibility" when referring to the reliability or repeatability of serological tests. The practical use of the concept, however, has been limited by the absence of an appropriate numerical scale on which differing reproducibilities can be quantified and objectively compared. This limitation can be overcome by adopting the proposed quantitative measure of reproducibility. The recommended measure is a natural extension of the common practice of considering a serological test to be acceptably reporducible so long as replicate titers remain within a twofold range. The measure can be readily used in the field of serology, and examples are given of how this can be done.
Bacteriology of sputum in cystic fibrosis: evaluation of dithiothreitol as a mucolytic agent
Authors: Hammerschlag M R , Harding L , Macone A , Smith A L , Goldmann D A
Published: January 2020

Liquefaction and homogenization have been recommended to ensure accurate, representative sputum cultures. We evaluated dithiothreitol (DTT) as mucolytic agent for culturing sputum samples obtained from 79 cystic fibrosis (CF) patients. Liquefaction with DTT was not superior to direct plating of specimens for routine qualitative cultures. Unliquefied sputum cultures failed to direct 3 of 47 Pseudomonas aeruginosa isolates; DTT-treated specimens missed 5 of 13 Candida albicans isolates. Neither treated nor untreated sputum cultures were completely successful in detecting Staphylococcus aureus or Enterobacteriaceae. Since Haemophilus influenzae was recovered from only two qualitative cultures, we could not evaluate the effect of DTT on the receovery of this organism. However, 27 of 29 strains of H. influenzae were inhibited by concentrations of DTT near the recommended final working concentration of 50 micrograms/ml, suggesting that liquefaction might impair isolation of this organism. Liquefaction with DTT permitted quantitative cultures of CF sputum. The predominant pathogen in our CF population was P. aeruginosa; 37 of 43 (86%) patients were colonized with this organism. Median densities of rough and mucoid strains were 3.2 x 10(7) and 4.3 x 10(7) colony-forming units per ml, respectively. Previous oral antistaphylococcal therapy may have accounted for the observed low density of S. aureus (mean density, 3.5 x 10(3) colony-forming units per ml). We conclude that DTT treatment does not improve recovery of organisms from qualitative cultures but does facilitate quantitative studies of S. aureus and P. aeruginosa in CF sputum.
Nontuberculous mycobacteria as unsuspected agents of dermatological infections: diagnosis through microbiological parameters
Authors: Damsker B , Bottone E J
Published: January 2020

Nontuberculous mycobacteria were identified as the agents of dermatological lesions in seven patients seen at The Mount Sinai Hospital from 1969 to 1979. Three patients had water-associated cutaneous lesions, three had abscesses at the site of an injection, and one had an erosive nasal lesion. In each of these instances, the mycobacterial etiology was not suspected, and diagnosis was achieved only after careful microbiological studies. These experiences emphasize that a mycobacterial etiology should be sought in chronic cutaneous lesions occurring at traumatized sites.
Use of immunoglobulin M antibody to hepatitis B core antigen in diagnosis of viral hepatitis
Authors: Hawkes R A , Boughton C R , Ferguson V , Lehmann N I
Published: January 2020

To determine the diagnostic value of hepatitis B core (HBc)-specific immunoglobulin M (IgM) antibody (anti-HBc IgM), the sera of six patients with known recent acute viral hepatitis B were examined for the presence of anti-HBc periodically for up to 21 months from the onset of the attack by a sensitive radioimmunoassay technique (CORAB, Abbott Laboratories). It was found that anti-HBc IgM was detectable for approximately 17 months from the onset of the illness. Hence the finding of anti-HBc IgM suggests infection by hepatitis B virus, probably within the preceding 1 to 2 years. A high level of anti-HBc IgM in the acute-phase serum of an individual with viral hepatitis is indicative of recent hepatitis B virus etiology; one patient, however, showed a low titer of anti-HBc IgM in the acute-phase serum sample, which remained virtually unchanged 15 months from onset. The diagnostic use of this serologaical marker is illustrated in 25 patients with viral hepatitis, in whose acute-phase sera anti-HBc was found.
Comparison of counterimmunoelectrophoresis and the capsular reaction test for typing of pneumococci
Authors: Henrichsen J , Berntsson E , Kaijser B
Published: January 2020

The capsular reaction test is recommended as the method of choice for typing of pneumococci. Counterimmunoelectrophoresis also works in most cases, but has the following definite drawbacks. (i) The polysaccharide type antigens of types 7F, 7A, 14, 33F, 33A, and 37 are neutral and therefore do not form precipitates when conventional buffers are used. (ii) Counterimmunoelectrophoresis does not permit differentiation between types within groups since many factor sera do not contain sufficient amounts of precipitating antibodies. Omniserum contains low-titered antibodies against cell wall antigens and also reacts with thioglycolate-containing broth.
Preparation and use of erythrocyte-globulin conjugates to Lassa virus in reversed passive hemagglutination and inhibition
Authors: Goldwasser R A , Elliott L H , Johnson K M
Published: January 2020

Conditions were defined for functional covalent coupling of anti-Lassa virus globulins to glutaraldehyde-fixed chicken erythrocytes. Tolylene-2,4-diisocyanate in a reaction mixture containing not more than 0.01 M NaCl produced uniformly good conjugates which were used in reversed passive hemagglutination (RPH) and reversed passive hemagglutination inhibition (RPHI) tests to detect Lassa virus antigens in infected cell cultures and specific antigens in Vero cell cultures. Identical results were obtained with this method and with immunofluorescent-antibody (IFA) staining in the detection and identification of Lassa virus isolated from human and rodent specimens from West Africa. The RPHI method was equal to IFA for serological diagnosis of acute human Lassa virus infection and superior to IFA, complement fixation, and a radioimmunoassay procedure for detection of Lassa virus antibodies in a human population where this infection is endemic.
Increased sensitivity of acid-fast smears
Authors: Rickman T W , Moyer N P
Published: January 2020

Evaluation of the centrifuges used in the mycobacteriology laboratory indicated a failure to develop sufficient relative centrifugal force for optimal concentration of acid-fast bacilli. Retrospective analysis of 14,509 specimens received between 1 July 1973 and 30 June 1975 and sedimented at 1,260 x g relative centrifugal force revealed a positive smear rate of 1.8% and a positive culture rate of 7.1%, with a correlation between positive paired smears and cultures of 25.2%. After increasing the relative centrifugal force from 1,260 x g to 3,800 x g at maximum radius, the positive smear and culture rates were 9.6 and 11.6%, respectively, with a correlation between positive paired smears and cultures of 82.4%. The sensitivity of acid-fast smears is directly related to the relative centrifugal force achieved while concentrating the specimen by centrifugation.
Indirect sandwich enzyme-linked immunosorbent assay for rapid detection of Streptococcus pneumoniae type 3 antigen
Authors: Drow D L , Manning D D
Published: January 2020

An indirect sandwich enzyme-linked immunosorbent assay for the detection of the polysaccharide antigen of type 3 pneumococcus (SSS-III) is reported. Polystyrene balls with attached anti-SSS-III antibody serve as the solid phase, and antigen is detected using an alkaline phosphatase-labeled antiglobulin conjugate. The reaction is quantitated by spectrophotometry. Concentrations of antigen are estimated by comparison with standard curves prepared with purified SSS-III. For this assay, the practical lower limit of detection of SSS-III is approximately 2 to 3 ng/ml, thus making the test sensitivity about 25 times that reported for counterimmunoelectrophoresis. In preliminary tests with simulated human clinical specimens, none of the body fluids tested (spinal fluid, serum, urine, and sputum) interfered with detection of antigen, nor did they produce false-positive or false-negative results. Streptococcus pneumoniae type 3 whole organisms were readily detected in simulated clinically positive sputum specimens. Cross-reactions were not observed with Haemophilus influenzae type b, group B Streptococcus, Klebsiella pneumoniae, Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa.
Cellular fatty acid composition of group IVe, a nonsaccharolytic organism from clinical sources
Authors: Dees S , Thanabalasundrum S , Moss C W , Hollis D G , Weaver R E
Published: January 2020

The cellular fatty acid composition of a group of gram-negative nonfermentative organisms designated group IVe was studied by gas-liquid chromatography. Strains of this group are isolated most frequently from urine and most closely resemble the Alcaligenes in conventional biochemical tests. On the basis of cellular fatty acids, however, we found these organisms to be strikingly different from Alcaligenes and other gram-negative species with similar phenotypic characteristics. The gas-liquid chromatography procedure offers an additional diagnostic test for rapid identification of unclassified bacteria like group IVe.
Evaluation of Fluoretec-M for detection of oral strains of Bacteroides asaccharolyticus and Bacteroides melaninogenicus
Authors: Mouton C , Hammond P , Slots J , Genco R J
Published: January 2020

Fluoretec-M is a polyvalent conjugate used in direct fluorescent-antibody staining for identification of the Bacteroides asaccharolyticus-Bacteroides melaninogenicus group. The Fluoretec-M reagent detected all oral and nonoral test strains of B. melaninogaenicus subsp. intermedius, all test strains of B. melaninogenicus subsp. melaninogenicus, and the nonoral strains of B. asaccharolyticus. However, the Fluoretec-M polyvalent reagent and the monovalent conjugates which constitute Fluoretec-M did not detect the oral strains B. asaccharolyticus. The use of Fluoretec-M can therefore generate false-negative results in studies of specimens from oral cavity and from nonoral sites in which an infection with B. asacacharolyticus of oral origin may have taken place. It is suggested that antibodies reactive with the oral antigenic type of B. asaccharolyticus be included in the preparative procedure of the Fluoretec-M reagent.
Immunofluorescence technique for detection of human cytomegalovirus (HCMV) antibodies against HCMV-induced late antigens with elimination of immunoglobulin G-receptor staining
Authors: Tardy-Panit M , Michelson S , Horodniceanu F
Published: January 2020

An immunofluorescence technique is described which permits the elimination of nonspecific cytoplasmic staining from late antigen preparations by using in situ a buffer containing Nonidet P-40.
Production of Phenylacetic and Hydroxyphenylacetic Acids by
Clostridium botulinum
Type G
Authors: Moss C. Wayne , Hatheway C. L. , Lambert M. A. , McCroskey L. M.
Published: January 2020

Phenylacetic and hydroxyphenylacetic acids were present as major acids in spent growth medium from
Clostridium botulinum
type G. These aromatic acids were identified by gas-liquid chromatography and mass spectrometry.
Rapid Laboratory Identification of
Neisseria gonorrhoeae
by Coagglutination
Authors: Helstad Arlan G. , Bruns Marcia K.
Published: January 2020

We compared the Phadebact Gonococcus Test with conventional methods in identifying 210 strains of
Neisseria gonorrhoeae.
Of these, 209 strains were correctly identified (99.5%).
Use of the API 20E system to identify veterinary Enterobacteriaceae
Authors: Swanson E C , Collins M T
Published: January 2020

A total of 503 veterinary enteric bacterial pathogens obtained from state veterinary diagnostic laboratories were tested on API 20E strips to determine whether this rapid microidentification system could be utilized for veterinary clinical microbiology. The API 20E strip accurately identified 96% of the veterinary isolates and misidentified 3%. Identifications by the API system and the diagnostic laboratories were in agreement in 85% of the isolates, disagreement on 16% of the isolates, and 1% were not identified by the API strip. Differences in identification occurred primarily in distinguishing between Klebsiella and Enterobacter and between Enterobacter and Escherichia coli. These disagreements were most often due to incorrect identifications by the diagnostic laboratory rather than by the API system. Biotype differences between human and veterinary isolates were compared. Significant differences were noted in several biochemical reactions. The main differences observed for E. coli isolates were in ornithine decarboxylase production and melibiose fermentation. The largest differences for Salmonella occurred in arginine dihydrolase production, citrate utilization, and inositol fermentation, whereas for Klebsiella pneumoniae the main differences were noted in urease production and nitrate reduction. These biotype differences, however, did not affect the accurate identification of organisms on the API strip.
Detection of rotavirus by serological trapping on antibody-coated electron microscope grids
Authors: Nicolaieff A , Obert G , van Regenmortel M H
Published: January 2020

A serological trapping technique for detecting rotaviruses is described which involves coating electron microscope grids with protein A and specific rotavirus antiserum. The presence of a layer of antibodies on the grid increases the number of rotavirus particles that can be visualized. Thirty-five crude fecal extracts from infants suffering from diarrhea were examined by the serological trapping technique and by standard electron-microscopy. When the specimens were deposited on antibody-coated girds, 71% of them were found to contain virus particles, compared with 20% on standard uncoated grids. The method is simple and rapid and does away with the need to concentrate the specimens.