bluuebunny/crossref_metadata_2025 huggingface dataset:
Relationships between alternative complement pathway activation, C-reactive protein, and pneumococcal infection
Authors: Rabinovitch R A , Koethe S M , Kalbfleisch J H , Preheim L C , Rytel M W
Published: January 2020

In the absence of specific antibody, opsonization of Streptococcus pneumoniae may be mediated by the alternative complement pathway (AP) or by C-reactive protein (CRP) via C1 binding. To determine the role of these mechanisms in pneumococcal (PNC) disease, we studied 19 patients with differing severities of PNC infection. C4 and CRP levels and zymosan-induced consumption of 50% hemolytic complement (CH50) were measured in specimens obtained acutely and then weekly. In patients with complicated illness, the modified mean CH50 in acute sera was 178 +/- 57 U/ml, significantly lower than the mean CH50 of 331 +/- 80 U/ml in patients with uncomplicated illness (P less than 0.05). The values of the two groups on a given day approximated each other on days 7, 14, and 23. Consumption of complement by zymosan was also lower in acute sera of patients with complicated illness, with a mean value of 19 +/- 18 U/ml compared with 58 +/- 30 U/ml in those with uncomplicated illness (P less than 0.05). This difference was also seen on day 7 (P less than 0.05). Disease involving lower-numbered PNC serotypes (less than 10) correlated with reduced availability of AP factors in acute sera, independent of illness severity. Mean CRP levels were inversely related to zymosan-induced complement activation in patients with complicated illness. These data suggest that in vivo depletion of AP factors is significantly greater in patients with complicated illness and is associated with high CRP levels. CRP may enhance AP activation via C3 convertase generation and function with it as a preantibody host defense mechanism.
Microbiological and microhardness evaluation of artificial enamel fissures worn intraorally by humans
Authors: Strassler H E , Minah G E , Kula K S
Published: January 2020

Devices simulating occlusal fissures were constructed from dental enamel and bonded to human maxillary molar teeth for 3 weeks. Facilitation of in vivo caries research in humans is the long-range goal for this model system. In the present investigation, microbial compositions of plaque in the fissural space of the model and natural fissural plaque from teeth bearing the devices were compared. Plaque from models constructed from either bovine or human enamel was also compared. In addition, microhardness of the enamel surfaces was examined before and after oral exposure. Plaque in both bovine and human enamel models differed significantly from natural fissural plaque in several microbial categories. Differences appeared to be related to the increased accessibility of the deep fissural contents of the models. For example, levels of the aciduric Streptococcus mutans and Veillonella species were higher in the models, although levels of a salivary inhabitant, Streptococcus salivarius, were lower. Plaque in bovine and human enamel models was similar, and both models showed significant decreases in enamel microhardness after oral exposure for 3 weeks. The model system should be useful in caries research in that carieslike activity was simulated within a relatively short period of time, and the fissural space became colonized by high levels of cariogenic bacteria.
Distribution of bacteria and yeasts within the 10-ml Isolator during the processing of seeded blood samples
Authors: Kellogg J A , Levisky J S
Published: January 2020

Forty-five organisms consisting of stock cultures and clinical isolates of bacteria and yeast were separately inoculated into outdated blood bank blood to achieve a concentration of approximately 100 CFU/ml. Blood with each organism was introduced into groups of four Isolators (E. I. du Pont de Nemours & Co., Inc., Wilmington, Del.), which were then processed according to the Isostat instructions of the manufacturer. The supernatant, sediment, and wash (material removed from the surface of the slanted stopper after sediment removal) were inoculated onto 5% sheep blood agar plates. Cultures were incubated aerobically (5 to 10% CO2) at 35 degrees C for 48 to 72 h. From the 180 Isolators, the mean recovery was 6% (range, 0 to 48%) for the supernatant, 87% (range, 47 to 98%) for the sediment, and 8% (range, 3 to 23%) for the wash. Neither variation among technologists nor intentional misalignment of additional Isolators in the centrifuge could explain all of the losses of microorganisms from the sediment. The manual nature of the Isolator procedure, which led to the loss of significant amounts of organisms from the sediment, may help to explain false-negative Isolator results obtained from blood of patients, particularly when small numbers of pathogens are present.
Comparison of quantitative and semiquantitative culture techniques for burn biopsy
Authors: Buchanan K , Heimbach D M , Minshew B H , Coyle M B
Published: January 2020

Accurate evaluation of bacterial colonization as a predictive index for wound sepsis has relied on a quantitative culture technique that provides exact colony counts per gram of tissue by culture of five serial dilutions of biopsy tissue homogenate. The method, while useful to the physician, is both labor intensive and expensive. In this study 78 eschar biopsies were cultured by a semiquantitative technique that involved the use of 0.1- and 0.01-ml samples of inocula and by the serial dilution method. Exact colony counts from the semiquantitative culture method were available only from cultures containing 10(4) to 10(6) CFU/g of tissue. Other colony counts were reported as less than 10(4) or greater than 10(6) CFU/g. Agreement by category of colony counts between the two methods was 96%. For prediction of wound sepsis, the semiquantitative procedure had a positive predictive value of 100% and a negative predictive value of 93.7%. This method also resulted in an approximately 30% reduction of work units (as defined by the College of American Pathologists) and a 60% reduction in the amount of media for specimen processing. Therefore, this semiquantitative culture technique provides accurate information to the physician while saving both time and materials.
Exoantigen test for Cladosporium bantianum, Fonsecaea pedrosoi, and Phialophora verrucosa
Authors: Espinel-Ingroff A , Shadomy S , Dixon D , Goldson P
Published: January 2020

Exoantigens from 10-day-old cultures of 100 isolates of pathogenic and saprophytic dematiaceous fungi were analyzed by the exoantigen test. Antisera to Cladosporium bantianum ATCC 10958, Fonsecaea pedrosoi CDC AMO-B06, and Phialophora verrucosa CDC AMO-C12 were prepared in New Zealand rabbits immunized with soluble antigens from 1-month-old cultures. Absorbed and nonabsorbed antisera and exoantigens from the same organisms were used as reference reagents. Serologic reactions were analyzed in terms of the presence or absence of lines of identity or nonidentity. These reactions allowed presumptive differentiation of C. bantianum, F. pedrosoi, and Phialophora verrucosa from other dematiaceous fungi, including Cladosporium spp. (28 isolates), Exophiala spp. (18 isolates), Fonsecaea spp. (17 isolates). Lecythophora hoffmannii (4 isolates), Phaeoannellomyces werneckii (3 isolates), Phialophora spp. (17 isolates), Wangiella dermatitidis (9 isolates), and Rhinocladiella spp. (4 isolates).
Evaluation of chlamydiazyme for the detection of genital infections caused by Chlamydia trachomatis
Authors: Howard L V , Coleman P F , England B J , Herrmann J E
Published: January 2020

Chlamydiazyme is a 4-h enzyme-linked immunoassay that detects an antigen of Chlamydia trachomatis directly in clinical specimens. This immunoassay was compared with cell culture for the diagnosis of chlamydial infections of the genital tract. The assay was evaluated at five clinics with a total of 1,277 cervical specimens of which 239 were culture positive. At three of these clinics where urethral samples were taken from males, 99 of 363 samples were culture positive. The sensitivity of the assay averaged 89.5% for detecting cervical infections and 78.8% for detecting male urethral infections. Specificity was 97.0% when samples from either males or females were tested. Some patients who were culture negative were infected with chlamydiae according to both Chlamydiazyme and a monoclonal antibody test that detected a chlamydial antigen distinct from the antigen detected by Chlamydiazyme. If the 15 females and 2 males who were positive by both immunoassays but culture negative were considered positive for chlamydial infection, the specificity of the assay was 98.4% in females and 97.7% in males. Chlamydiazyme is a simple and relatively rapid immunoassay that has sufficient sensitivity and specificity to supplant culture in the detection of genital chlamydial infections.
Enzyme-linked immunosorbent assay for detection of Staphylococcus epidermidis antibody in experimental S. epidermidis endocarditis
Authors: Espersen F , Wheat L J , Bemis A T , White A
Published: January 2020

The immune response against Staphylococcus epidermidis, as determined by an enzyme-linked immunosorbent assay, was evaluated in experimental S. epidermidis infections in rabbits. Antigens from 8 of 10 clinical S. epidermidis strains detected significant antibody production in five rabbits immunized with different strains of S. epidermidis and in five of six rabbits with experimental endocarditis caused by four different strains. The antigens from two strains detected antibody production in all rabbits, and strain ATCC 14990 discriminated best between positive and negative samples. Consecutive blood samples from rabbits with endocarditis and control rabbits with bacteremia, which were successfully prevented from developing endocarditis by using prophylactic antibiotics, were examined by using an enzyme-linked immunosorbent assay and an ultrasonic extract of strain ATCC 14990 as the antigen. This assay discriminated between rabbits with endocarditis and rabbits with uncomplicated bacteremia. Antibody production was detected as early as 3 days after the onset of infection in rabbits with endocarditis.
Endogenous activity of phospholipases A and C in Ureaplasma urealyticum
Authors: De Silva N S , Quinn P A
Published: January 2020

The results of recent studies support the concept that Ureaplasma urealyticum may be a major cause of perinatal infection in both term and preterm infants. It has been postulated that phospholipase degradation of placental phospholipids by microorganisms triggers the onset of premature labor. Since the presence of ureaplasmas in placentas is associated with pregnancy loss, prematurity, and neonatal morbidity, we assayed U. urealyticum for the presence of phospholipase A1, A2, and C activities. Phospholipase A1 activity was low in lysates of exponential-phase cells of U. urealyticum. Phospholipase A2 activity was present and was 100-fold higher than the activity of phospholipase A1 in serotypes 3,4, and 8. The total activity and specific activity of phospholipase A2 in serotype 8 were nearly threefold higher than the activities in serotypes 3 and 4. Cell lysates of all three serotypes showed the presence of phospholipase C activity during the exponential phase of growth, and no significant difference in activity was observed among the three serotypes. In stationary-phase cells the phospholipase C activity was 10-fold lower than the activity in exponential-phase cells. Our results demonstrate that phospholipase activities are present in U. urealyticum cells and that the specific activities of phospholipase A2 differed among the three serotypes tested, while the activities of phospholipases A1 and C were similar.
Specific and common antigenic determinants of Candida albicans isolates detected by monoclonal antibody
Authors: Polonelli L , Morace G
Published: January 2020

We isolated a hybridoma cell line which produced monoclonal antibody to one determinant of an exoantigen of Candida albicans. The immunoglobulin G antibody product was characterized by using a Western blot technique and was used for a serological analysis of numerous homologous and heterologous yeast isolates. Based on specific immunologic determinants, C. albicans strains were identified and clustered into five groups. The monoclonal antibodies were effective reagents for identifying and serotyping our C. albicans isolates; they have potential application in the epidemiology of yeast infections.
Intracranial infection by Vibrio alginolyticus following injury in salt water
Authors: Opal S M , Saxon J R
Published: January 2020

A 20-year-old man presented with an epidural abscess 3 months after a seawater diving accident. Cultures of the abscess cavity obtained by surgical drainage revealed a pure culture of Vibrio alginolyticus. Marine vibrios may produce serious intracranial infection after head injury in salt water.
Effect of using heat-inactivated serum with the Abbott human T-cell lymphotropic virus type III antibody test
Authors: Jungkind D L , DiRenzo S A , Young S J
Published: January 2020

The Abbott enzyme immunoassay (Abbott Laboratories, North Chicago, Ill.) for human T-cell lymphotropic virus type III (HTLV-III) antibody was evaluated to determine the effect of using heat-inactivated (56 degrees C for 30 min) serum as the sample. Each of 58 nonreactive serum samples gave a higher A492 value when tested after heat inactivation. Ten of the samples became reactive after heating. Heat-inactivated serum should not be used in the current Abbott HTLV-III antibody test, because this can cause false-positive results.
Single-serum diagnosis of rubella by combined use of the hemagglutination inhibition and passive hemagglutination tests
Authors: Inouye S , Satoh K , Tajima T
Published: January 2020

We explored the feasibility of using the passive hemagglutination (PHA) test in combination with the hemagglutination inhibition (HI) test for the single-serum diagnosis of rubella. We found by sedimentation analysis of the serum that early 7S antibody produced within 1 month after the onset of the rash had high HI but much lower PHA titers, whereas the PHA titers of antibody produced later were slightly higher than the HI titers. (19S antibody in the early serum had some PHA activity.) This disparity between the HI and PHA activities of the early 7S antibody could be used for the routine diagnosis of rubella. A comparison of the HI titers of the test serum with the PHA titers of mercaptoethanol-treated serum constitutes a simple method for determining whether the serum sample was taken shortly or remotely after the infection.
Strain characterization and grouping of Campylobacter jejuni and Campylobacter coli by interaction with lectins
Authors: Wong K H , Skelton S K , Feeley J C
Published: January 2020

Strains of Campylobacter jejuni and Campylobacter coli were characterized and grouped by their distinct reaction patterns with lectins. Heating of the Campylobacter cultures to 100 degrees C and holding for 30 to 60 min greatly enhanced their reactivity with lectins and permitted the grouping of all but 3 of 155 cultures tested in this study without interference of autoagglutination and other nonspecific activities. The lectin reaction patterns of the heated cultures were stable and reproducible. They were strain specific and independent of the heat-stable antigenic types. The lectin-reactive sites of C. jejuni and C. coli may be useful as additional markers for strain characterization. Based on these observations, a simple slide agglutination procedure is described for differentiating strains of C. jejuni and C. coli by their interaction with a selected group of commercially available lectins.
Emergence of bactericidal and opsonizing antibody to Vibrio vulnificus following bacterial infection
Authors: Musher D M , Hansen M V , Goree A , Gyorkey F , Chapman A J , Baughn R E
Published: January 2020

Virulent isolates of Vibrio vulnificus resist the bactericidal and opsonizing effects of normal human serum, in contrast to environmental isolates, which are highly serum susceptible. Immune responses to bacteremic V. vulnificus infections in human subjects have not been characterized. Serum from a patient who survived sepsis caused by V. vulnificus had substantial bactericidal and opsonizing immunoglobulin G (IgG) for his own bloodstream isolate. Killing was mediated by the classical complement pathway, whereas opsonization was effected by either the classical or the alternative pathway. IgG that reacted strongly with 55-, 58-, and 68-kilodalton outer membrane proteins was present in the patient's convalescent-phase serum but was absent from normal human serum. These findings suggest that humoral immunity to V. vulnificus, mediated by bactericidal and opsonizing antibody, emerges during infection and may be due, in part, to IgG directed against identifiable outer membrane proteins.
Adsorption, purification, and growth characteristics of hepatitis A virus strain HAS-15 propagated in fetal rhesus monkey kidney cells
Authors: Wheeler C M , Fields H A , Schable C A , Meinke W J , Maynard J E
Published: January 2020

A human fecal isolate of hepatitis A virus strain HAS-15 was adapted to rapid growth in FRhK-4 cells by more than 20 7-day passages. A cell culture-derived inoculum of strain HAS-15 was used at a multiplicity of infection of 80 radioimmunofocus-forming units per cell, and a one-step growth curve was determined. Both intracellular production and supernatant release of infectious virions were evaluated. Detection of virus release into the medium directly corresponded to intracellular production of infectious virions. A classical eclipse period was not observed during the growth curve determinations; however, detectable infectious virion production was absent for approximately 20 h after infection. This 20-h period was immediately followed by a 4-day logarithmic phase of virus production. A maximum intracellular virus titer of 10(9) radioimmunofocus-forming units per ml was achieved, and this level remained essentially constant for up to 14 days after infection. The infectious virus and viral antigen produced during the growth cycle were ascertained by a radioimmunofocus assay and by a radioimmunoassay, respectively. Cell culture supernatants were negative for viral antigen as determined by the radioimmunoassay, even though as many as 10(8) hepatitis A virus radioimmunofocus-forming units per ml were found. An adsorption study was also performed with strain HAS-15 by using FRhK-4 cells. More than 99.9% of the infectious virus was adsorbed at 25 degrees C in less than 20 min.
Simplified lysed-blood culture technique
Authors: Zierdt C H
Published: January 2020

A blood culture system was developed in which a lysing agent (either Tween 20, one of several other polyoxyethylene adducts, digitonin, or Triton X-100) is added to the blood culture medium. Of 33 Triton compounds, 9 lysed human blood, as did 7 of 21 polyoxyethylene compounds and digitonin, all at a concentration of 0.05%. Under the specific test conditions, three of the hemolytic polyoxyethylene compounds and digitonin had no inhibitory effect. All of the Triton compounds had at least some inhibitory effect on the most sensitive of the pathogenic bacteria that were tested, Streptococcus pneumoniae and Neisseria meningitidis. Because of results from previous studies, Triton X-100 was tested further, despite evidence in this study of its inhibition of bacteria. Of the 55 lysing agents tested, digitonin, Triton X-100, Brij 96, and Tween 20 were selected for further testing as additions to conventional culture broth. Comparative culture studies with bacteremic blood from infected rabbits were performed with the conventional blood culture, the Isolator system (Du Pont Co., Wilmington, Del.), and the new lysing medium. The new system has the advantages of lysis filtration and lysis centrifugation without the associated added cost and processing complexity.
Serospecificity of a cloned protease-resistant Treponema pallidum--specific antigen expressed in Escherichia coli
Authors: Coates S R , Sheridan P J , Hansen D S , Laird W J , Erlich H A
Published: January 2020

We evaluated the serological reactivity of a protease-resistant antigen designated 4D which was encoded by Treponema pallidum DNA and was expressed in Escherichia coli from recombinant plasmid pAW329. This 19,000-molecular-weight antigen was purified in its native, non-protease-treated form from E. coli sonic extracts by molecular sieving and ion-exchange chromatography. Antibody binding to antigen 4D was detected by a radioimmunoassay. Antigen 4D-specific antibody was detected in 95% of the sera in a Centers for Disease Control syphilis serum panel. It was also detected in 55% of 121 primary syphilis patients, whereas syphilis antibody was detected in 83% of the sera by a fluorescent treponemal antibody absorption test and in 88% of the sera by a T. pallidum microhemagglutination test. In tests of 118 normal sera, less than 3% demonstrated antibody to antigen 4D; these results are similar to microhemagglutination and fluorescent treponemal antibody absorption test results. Rabbit antisera against Treponema phagedenis, Treponema refringens, Treponema denticola, and Treponema vincentii did not react with antigen 4D.
Identification of epitopes on respiratory syncytial virus proteins by competitive binding immunoassay
Authors: Anderson L J , Hierholzer J C , Stone Y O , Tsou C , Fernie B F
Published: January 2020

To characterize the interrelationship of monoclonal antibodies (MAbs) against respiratory syncytial virus (RSV) and their respective epitopes, we developed a competitive binding assay based on the biotin-avidin system and a tissue culture enzyme-linked immunosorbent assay. The competitive binding assay clearly distinguished between competing and noncompeting MAbs. Eight MAbs against the fusion protein (F protein) demonstrated two blocking patterns consistent with two antigenic sites. MAbs reacting at one site neutralized the virus, while those reacting at the other site did not. Eight MAbs against the large glycoprotein (G protein) demonstrated five blocking patterns consistent with three antigenic sites, one with three epitopes and the other two with one each. None of the MAbs against G protein neutralized the virus. The reaction pattern of the MAbs against three strains of RSV identified three additional epitopes on the F protein and no additional epitopes on the G protein. The epitopes on G protein showed the greatest antigenic diversity among the three strains. These results help us better understand the functional and antigenic structure of the two surface glycoproteins of RSV.
Rapid detection of respiratory syncytial virus in nasopharyngeal aspirates by a commercial enzyme immunoassay
Authors: Swenson P D , Kaplan M H
Published: January 2020

A commercial enzyme immunoassay (EIA) for the rapid detection of respiratory syncytial virus (RSV) in respiratory secretions was evaluated by comparison with both virus isolation in HEp-2 cells and indirect immunofluorescence (IFA) staining of exfoliated respiratory cells. Initial examination of 80 nasopharyngeal aspirates collected from infants with acute respiratory illness showed that the RSV EIA was positive for 21 of 24 specimens positive by virus isolation or IFA (87.5% sensitivity) and negative for 53 of 56 specimens negative by virus isolation and IFA (95% specificity). The EIA appears to be an acceptable and more rapid test than virus isolation for the detection of RSV, especially for laboratories in which prompt inoculation of specimens is not always possible. IFA staining with commercial bovine anti-RSV serum was found to be the most sensitive and rapid test for the detection of RSV. However, three of four specimens positive by IFA and negative by virus isolation were not cultured under optimal conditions. In addition, the IFA test requires a highly trained technologist to interpret the staining results.
Evaluation of broth disk elution methods for susceptibility testing of anaerobic bacteria with the newer beta-lactam antibiotics
Authors: Jorgensen J H , Redding J S , Howell A W
Published: January 2020

Broth disk elution procedures represent one of the most practical means for clinical laboratories to perform routine antibiotic susceptibility tests on anaerobic bacteria. The accuracy of five disk elution test methods and media (including the one to be proposed by the National Committee for Clinical Laboratory Standards) was evaluated for the testing of newer beta-lactam antibiotics, including cefoperazone, cefotaxime, cefoxitin, ceftazidime, ceftizoxime, moxalactam, and piperacillin. Various numbers of antibiotic disks were used to achieve disk elution test concentrations which approximated the highest MIC termed susceptible by the Food and Drug Administration. A group of 88 anaerobes representing many different species was tested in parallel by the five disk elution methods and the National Committee for Clinical Laboratory Standards reference agar dilution procedure. Overall, full agreement between the reference agar dilution MICs and the disk elution category results was 88.3% for PRAS BHI, 84.5% for Schaedler, 85.7% for thioglycolate, and 87.4% for Wilkins-Chalgren broth. Essential agreement (+/- 1 twofold MIC increment from the disk elution concentration) was achieved with 94.6% of PRAS BHI tests, 94.3% of Schaedler tests, 93.6% of thioglycolate tests, and 95.7% of Wilkins-Chalgren tests. Due to growth failures with a number of isolates and difficulties in interpreting results, the use of Wilkins-West broth was discontinued after approximately one-half of the isolates had been tested. The majority of errors with all of the disk elution methods occurred with isolates (most notably members of the Bacteroides fragilis group) having MICs near the single test concentrations used in the disk methods. With the notable exception of tests for the B. fragilis group, the disk elution methods offered acceptable accuracy with the newer beta-lactam antibiotics tested in this study.
Prevalence, species differentiation, and toxigenicity of Aeromonas strains in cases of childhood gastroenteritis and in controls
Authors: Figura N , Marri L , Verdiani S , Ceccherini C , Barberi A
Published: January 2020

In a 1-year period (January to December 1984), Aeromonas strains were isolated from feces of 21 of 561 (3.7%) children with gastroenteritis and from 12 of 576 (2.1%) children without intestinal disturbances (controls). The difference between the two isolation rates was not significant (X2 = 2.2; P greater than 0.05). In five cases of illness other intestinal pathogens were isolated together with Aeromonas in the same stool sample. A total of 39 Aeromonas strains were detected since in some cases aeromonads with different biochemical characteristics were obtained from the same stool sample. Of the 39 Aeromonas isolates, 6 strains (5 from patients) were Aeromonas hydrophila, 5 strains (3 from patients) were Aeromonas sobria, and 26 strains (18 from patients) were Aeromonas caviae; 2 strains isolated from controls did not ferment sucrose and were considered a distinct group of Aeromonas. We found no significant difference between the prevalence of each of these species from patients and the prevalence from controls. We found no significant difference in the prevalence of enterotoxin-producing strains (suckling mouse model), cytotoxin-producing strains (HEp-2 cell model), or hemolysin-producing strains (rabbit erythrocyte model) between patients and controls. In our geographical region there is no evidence that Aeromonas species are primary intestinal pathogens in children.
Selective and differential medium for the primary isolation of members of the Proteeae
Authors: Hawkey P M , McCormick A , Simpson R A
Published: January 2020

A new differential and selective medium for the isolation of members of the Proteeae, PIM (Proteeae isolation medium) agar, was developed and evaluated. The medium relies on the ability of all members of the Proteeae (with the exception of a very few Morganella morganii strains) to produce a dark brown pigment in medium containing DL-tryptophan. An additional differential property, tyrosine degradation, was also demonstrated by the medium. Members of the Proteeae appeared as dark brown colonies with a halo of clearing of fine tyrosine crystals when cultured on PIM agar. Occasional strains of Citrobacter sp. and Pseudomonas aeruginosa may degrade tyrosine, but none has the ability to produce dark brown pigmentation on PIM agar. Quantitative recovery studies showed that the addition of 5 mg of clindamycin per liter suppressed gram-positive bacteria without inhibiting any strains of the Proteeae. The addition of 100 mg of colistin per liter made the medium highly selective for strains of the Proteeae, but approximately 10% of the strains were not isolated, thus making this formulation unsuitable for general surveys of the occurrence of members of the Proteeae. PIM agar should aid the investigation of episodes of cross infection caused by members of the Proteeae and the isolation of the new species of the Proteeae recently described.
Composition and antimicrobic resistance of skin flora in hospitalized and healthy adults
Authors: Larson E L , McGinley K J , Foglia A R , Talbot G H , Leyden J J
Published: January 2020

The aerobic bacterial flora of the skin of the anterior nares, axilla, perineum, and toe web in a group of 37 patients hospitalized for at least 2 weeks was compared with the flora of 30 healthy adults. Colony counts were significantly higher for flora of the perineum and toe web in both groups (P less than 0.05). Patients had significantly higher carriage rates of Proteus, Pseudomonas, and Candida spp. (P less than 0.01). Staphylococcus haemolyticus was isolated more frequently from patients, and S. hominis was isolated more frequently from controls (P less than 0.01). Patient microflora, including gram-positive cocci, gram-negative bacilli, large-colony diphtheroids, and lipophilic diphtheroids, showed a high degree of resistance to multiple antimicrobial agents. The gram-positive coccal flora of patients was significantly more resistant than that of controls for 8 of 10 antimicrobial agents tested. Methicillin resistance occurred in only 2.9% of isolates from controls, but in 44.3% from patients (P less than 0.01). This extensive survey identifies qualitative and quantitative differences in skin flora and confirms that significantly higher levels of antimicrobial resistance are present in all types of organisms from a number of skin sites in hospitalized patients.
Commercial latex test for Clostridium difficile toxin A does not detect toxin A
Authors: Lyerly D M , Wilkins T D
Published: January 2020

The rapid latex test recently marketed by Marion Scientific (Div. Marion Laboratories, Inc., Kansas City, Mo.) for the detection of Clostridium difficile toxin A does not react with the toxin, based on the following findings: culture filtrates from nontoxigenic strains of C. difficile gave positive reactions in the test, culture filtrate in which toxin A had been removed gave positive reactions, purified toxin A did not react in the test, and the latex reagent bound an antigen which is distinct from toxin A and which is produced in various amounts by both toxigenic and nontoxigenic strains of C. difficile.
Comparison of a new commercially prepared porphyrin test and the conventional satellite test for the identification of Haemophilus species that require the X factor
Authors: Gadberry J L , Amos M A
Published: January 2020

A test with a commercially developed porphyrin test agar was examined for the identification of Haemophilus spp. The porphyrin test agar method was compared with the conventional paper strip satellite method in tests with 187 isolates and was found to be easier to perform and interpret, giving a sensitivity of 98.7% and specificity of 94.7%.
Major outer membrane protein of Legionella pneumophila carries a species-specific epitope
Authors: Nolte F S , Conlin C A
Published: January 2020

A monoclonal antibody (LP3IIG2) directed against a species-specific epitope of Legionella pneumophila is available from Genetic Systems Corp., Seattle, Wash., for use as a diagnostic reagent. Outer membrane protein-rich fractions were prepared from L. pneumophila serogroups 1 to 8 by treatment of cell envelopes with 2% Triton X-100. Immunoblots of sodium dodecyl sulfate-polyacrylamide gels demonstrated that each membrane fraction contained two bands that reacted with LP3IIG2. The monoclonal antibody bound preferentially to a 26,000-molecular-weight band that appears to result from modification of the 29,000-molecular-weight major outer membrane protein.
Wound colonization by Ewingella americana
Authors: Bear N , Klugman K P , Tobiansky L , Koornhof H J
Published: January 2020

Ewingella americana was recovered from a wound on the left leg of a 46-year-old male after a compound fracture of the tibia and fibula. Compared with the reported characteristics of 44 American strains, this strain was shown to belong to biogroup 1. The isolation of this bacterium in South Africa confirms its wide geographical distribution in clinical specimens. Colonization was not associated with clinical deterioration.
Rapid detection of herpes simplex virus in clinical specimens by centrifugation and immunoperoxidase staining
Authors: Salmon V C , Turner R B , Speranza M J , Overall J C
Published: January 2020

The effect of immunoperoxidase staining and centrifugation on the sensitivity and rapidity of herpes simplex virus detection in mink lung cell cultures was determined with 730 clinical specimens. In standard tube cultures, the use of immunoperoxidase staining resulted in detection of 31 (91%) of 34 positive cultures after overnight incubation, compared with 25 (74%) detected without the stain (P less than 0.05). The effect of centrifugation of specimens onto the monolayer followed by overnight incubation and immunoperoxidase staining was studied with 431 specimens. Of 107 positive specimens, 103 (96%) were detected by this method, compared with 91 (85%) detected in standard cell cultures observed for 5 days (P less than 0.02). Standard cell cultures that were examined after overnight incubation detected only 62 (58%) of the 107 positive specimens (P less than 0.001). Centrifugation of clinical specimens onto cell monolayers followed by overnight incubation and immunoperoxidase staining is more rapid and sensitive than are standard cell culture techniques for the laboratory diagnosis of herpes simplex virus infection.
Evaluation of cell line 293 for virus isolation in routine viral diagnosis
Authors: Brown M , Petric M
Published: January 2020

Cell line 293, a continuous line of transformed human embryonic kidney cells, has been recognized for its sensitivity in the isolation of adenoviruses, particularly the fastidious species 40 and 41, from stool specimens. To explore the possibility of using this cell line for the isolation of other viruses from clinical specimens, 293 cells were tested for their susceptibility to a variety of viruses including herpes simplex virus, parainfluenza viruses, respiratory syncytial virus, and the enteroviruses ECHO 11, coxsackie B5, and coxsackie B6. All of the viruses induced a cytopathic effect in 293 cells. Consequently, 293 cells were introduced into the diagnostic laboratory and used along with primary African green monkey kidney (AGMK) cell cultures for the inoculation of all respiratory and stool specimens. The study represents a retrospective analysis of the performance of 293 cells over a 22-month period. It was confirmed that 293 cells were more sensitive than AGMK cells for the isolation of adenoviruses from both respiratory and stool specimens. The 293 cells were also sensitive for the isolation of enteroviruses (untyped) but more so from stool specimens than from respiratory specimens. Parainfluenza virus and respiratory syncytial virus were only rarely isolated in 293 cells. Herpesvirus isolates were obtained with equal frequency in both 293 and AGMK cells. This retrospective analysis confirms the value of 293 cells for the isolation of adenoviruses and demonstrates that 293 cells are also useful for the isolation of certain enteroviruses from both respiratory and stool specimens.
Detection of pathogenic Campylobacter species in blood culture systems
Authors: Wang W L , Blaser M J
Published: January 2020

Because differences in recognition of Campylobacter fetus and Campylobacter jejuni in systemic infections may be due partially to differences in the ability to cultivate these organisms, we studied their growth characteristics in two widely used blood culture systems. In the Roche Septi-Chek system (Hoffman-La Roche, Inc., Nutley, N.J.), over a broad range of inocula all strains were detected in broth within 2 days and on paddles within 3 days. In the BACTEC 6B aerobic bottles (Johnston Laboratories, Inc., Towson, Md.), C. jejuni and C. fetus took a median of 5 and 3 days, respectively, to reach the growth index threshold. However, in the BACTEC 7D anaerobic bottles, C. fetus required a median of 2 days to reach the growth index threshold, whereas for C. jejuni the median was greater than 10 days. The poor performance of C. jejuni in both BACTEC systems may have been due to unfavorable incubation atmospheres and may partially explain why C. jejuni bacteremia is so infrequently detected. Overall, the Roche Septi-Chek system was excellent for detecting Campylobacter strains in blood cultures.
Feasibility of same-day identification of members of the family Vibrionaceae by the API 20E system
Authors: Overman T L , Overley J K
Published: January 2020

Sixty isolates, comprising nine species of the family Vibrionaceae, were tested with the API 20E 5-h same-day procedure (Analytab Products, Plainview, N.Y.). Included were 27 Aeromonas hydrophila isolates, 10 Aeromonas sobria isolates, 7 Aeromonas caviae isolates, 3 Plesiomonas shigelloides isolates, 3 Vibrio alginolyticus isolates, 3 Vibrio cholerae isolates, 1 Vibrio fluvialis isolate, 5 Vibrio parahaemolyticus isolates, and 1 Vibrio vulnificus isolate. The 5-h profile numbers were specific for the five Vibrio species and the Plesiomonas isolates. The three Aeromonas species shared seven 5-h profile numbers. Of the 63 5-h profile numbers generated by testing each isolate twice, 22 were identical to those found in the overnight analytical profile index. Of these, 20 were correct identifications, and two were incorrect. The remaining 41 5-h profile numbers were not found in the overnight analytical profile index. Because the 5-h analytical profile index does not contain any oxidase-positive organisms, the oxidase value was subtracted from the 63 5-h profile numbers to determine whether misidentifications could occur if the oxidase test was either not performed or not performed correctly. Only five of these factored profile numbers resulted in a possible misidentification. It is feasible, within limitations, to use the 5-h API 20E same-day procedure to identify the more commonly occurring members of the Vibrionaceae. The manufacturer should develop a data base for this purpose.
Human antibody response to herpes simplex virus-specific polypeptides after primary and recurrent infection
Authors: Kahlon J , Lakeman F D , Ackermann M , Whitley R J
Published: January 2020

Human antibody responses to specific polypeptides of herpes simplex virus types 1 and 2 (HSV-1 and HSV-2, respectively) were assessed in serial serum specimens from 18 infected patients by immunoblot technology. Nine patients had HSV-1 infections (six genital and three oral) and nine had HSV-2 genital infections. Antibodies to homologous and heterologous HSV antigens were studied and correlated with total microneutralization and enzyme-linked immunosorbent assay antibodies as well as correlated directly to purified glycoproteins. The data indicated a sequential appearance of antibodies to specific polypeptides, according to virus type and site of infection. After HSV-1 infection, the initial response was to glycoprotein B, but the same was not true for HSV-2 infection, where the initial response appeared to be to the type-specific glycoprotein G. A difference in sequential appearance of antibodies for the two viruses indicated greater reactivity to lower-molecular-weight polypeptides after genital infection, irrespective of type, in contrast to nongenital HSV-1 infections. The antibody responses for selected sera to purified glycoproteins B and D were verified by enzyme-linked immunosorbent assay antibody determinations.
Evaluation of an enzyme immunoassay for the diagnosis of chlamydial infections in urogenital specimens
Authors: Tjiam K H , van Heijst B Y , van Zuuren A , Wagenvoort J H , van Joost T , Stolz E , Michel M F
Published: January 2020

A total of 194 male urethral and 402 cervical specimens were obtained from patients at the venereal disease outpatient clinic of University Hospital, Rotterdam, The Netherlands, to evaluate the IDEIA test (Boots Celltech) for the detection of chlamydial infections. The prevalences of culture-positive males and females were 17.5 and 8.2%, respectively. The respective overall sensitivities and specificities found were 67.6 and 93.7% for the males and 63.6 and 93.8% for the females. The highest sensitivity (83.3%) was found in male patients with more than 20 leukocytes per field in the sediment of the first-voided urine (magnification, X250) and in women with more than 10 leukocytes per field in a cervical Gram stain (magnification, X800). However, in men without urethritis and in women with fewer than 10 leukocytes per field in the Gram stain, sensitivities of 44.4 and 40%, respectively, were found. Culture-positive, IDEIA-negative results were predominantly observed in samples with few inclusions in the culture.
Group C rotaviruses in humans
Authors: Bridger J C , Pedley S , McCrae M A
Published: January 2020

Atypical rotaviruses obtained from human feces from Australia, Brazil, and the United Kingdom were shown by a combination of techniques--immunoelectron microscopy, immunofluorescence, genome profile analysis, terminal fingerprint analysis of genome segments, and dot-blot hybridization--to be related to group C porcine rotaviruses. The prevalence of antibody to group C rotaviruses was found to be low in human sera and immunoglobulin pools from six countries. No signs of infection were obtained when one of the human viruses was inoculated into gnotobiotic piglets. We conclude that the atypical human viruses are the first examples of group C rotaviruses in humans.
Development of a standardized subgrouping scheme for Legionella pneumophila serogroup 1 using monoclonal antibodies
Authors: Joly J R , McKinney R M , Tobin J O , Bibb W F , Watkins I D , Ramsay D
Published: January 2020

A panel of monoclonal antibodies to Legionella pneumophila serogroup 1 and a subclassification scheme were developed in a collaborative project among three laboratories. The seven most useful monoclonal antibodies were selected from three previously developed panels on the basis of indirect fluorescent antibody patterns with 83 strains of L. pneumophila serogroup 1 that were obtained from widely distributed geographic locations. The isolates were divided into 10 major subgroups on the basis of reactivity patterns that can be readily reproduced in any laboratory and are not subject to major inconsistencies of interpretation of staining intensity. A standard protocol for the indirect fluorescent antibody procedure was also developed.
Evaluation of a commercial kit for the routine detection of Clostridium difficile cytotoxin by tissue culture
Authors: Wu T C , Gersch S M
Published: January 2020

The Toxi-titer microtiter plate system (Bartels Immunodiagnostic Supplies, Inc., Bellevue, Wash.) is a simplified procedure for detecting the cytotoxin produced by Clostridium difficile in stool filtrates. In a parallel study of 74 stool specimens, results from the Toxin-titer system compared favorably with those from the conventional system. Our experience with the Toxin-titer system in testing 540 stool specimens was, in general, satisfactory, although a few problems with toxin control did occur. The method requires no specialized experience in tissue culture techniques and can therefore be adopted for routine use in clinical laboratories.
Enhanced isolation of respiratory syncytial virus in cell culture
Authors: Arens M Q , Swierkosz E M , Schmidt R R , Armstrong T , Rivetna K A
Published: January 2020

During two winter seasons, we found that the combination of WI-38 or MRC-5 human lung fibroblasts plus primary rhesus monkey kidney (RhMK) and HEp-2 cell cultures yielded maximal isolation of respiratory syncytial virus. Cytopathic effects (CPE) developed earliest in RhMK cells and slowest in the human fibroblast lines. In RhMK cells, 50% of ultimately positive cultures showed CPE in 5 days, and 90% of positive cultures showed CPE within 7 days during both respiratory syncytial virus seasons.
Immunodiffusion test for diagnosing and monitoring pythiosis in horses
Authors: Mendoza L , Kaufman L , Standard P G
Published: January 2020

A practical, sensitive, and specific immunodiffusion test was developed for diagnosing and monitoring pythiosis in horses. Culture filtrates, a soluble cell mass, and trypsinized Pythium sp. antigens were evaluated against prepared rabbit anti-Pythium sp. serum and pythiosis horse case sera. The culture filtrate antigens demonstrated the greatest capacity for detecting precipitins and the greatest stability during storage. In contrast, the trypsinized antigens had the weakest capability for detecting multiple precipitins and the poorest stability. The 13 sera from horses with proven active pythiosis were positive in immunodiffusion tests with the culture filtrate antigens. Each serum contained from three to six precipitins. Treated horses lost precipitins, and some became antibody negative. No false-positive reactions were noted in tests with sera from normal horses and humans or with sera from a variety of heterologous horse and human infections.
The role of beta-lactamase in staphylococcal resistance to penicillinase-resistant penicillins and cephalosporins
Authors: McDougal L K , Thornsberry C
Published: January 2020

We showed that most Staphylococcus aureus strains that have borderline or intermediate susceptibility to the penicillinase-resistant penicillins (PRPs) react this way because of the activity of their beta-lactamase on these antimicrobial agents. These strains produced large amounts of staphylococcal beta-lactamase that rapidly hydrolyzed penicillin and partially hydrolyzed the PRPs. Susceptibility to hydrolysis was penicillin greater than oxacillin greater than cephalothin greater than methicillin. The borderline results and the hydrolysis could be prevented by the beta-lactamase inhibitors clavulanic acid and sulbactam. For intrinsically methicillin-resistant (heteroresistant) S. aureus, the inhibitors reduced the penicillin MICs, but the strains remained resistant to all the beta-lactam antimicrobial agents, including penicillin. We conclude that the borderline in vitro susceptibility or resistance to PRPs in most of these S. aureus strains is mediated by beta-lactamase and they are not heteroresistant or intrinsically resistant. We do not know whether this in vitro resistance is expressed clinically.