bluuebunny/crossref_metadata_2025 huggingface dataset:
Characteristics of different solid-phase immunoassay formats for the measurement of BK virus immunoglobulin M in sera of patients on renal dialysis or with kidney allografts
Authors: Mahony J , Zapata M , Chernesky M
Published: January 2020

Solid-phase immunoglobulin M (IgM) antigen capture enzyme immunoassay (AgCEIA) and antibody capture enzyme immunoassay (AbCEIA) were developed for the diagnosis of BK virus (BKV) infections. Of 37 serum samples from renal allograft recipients, 15 were positive for BKV IgM antibody by either AgCEIA, AbCEIA, or antigen capture radioimmunoassay. False-positive IgM results were observed in the AgCEIA in the presence of high levels of BKV IgG antibody (titers greater than or equal to 1:51,200), when rheumatoid factor (RF) titers were greater than or equal to 1:20, or in the presence of high levels of RF (titers greater than or equal to 1:10,240) when BKV hemagglutination inhibition titers exceeded 1:40. False-positives due to RF could be eliminated by treatment of sera with anti-human IgG antisera or IgG-coated latex particles. The presence of RF did not, however, produce false-positive results in the AbCEIA. Both AgCEIA and AbCEIA were specific for BKV IgM antibody, as 14 serum samples containing either JC papovavirus, cytomegalovirus, rubella virus, hepatitis A virus, or hepatitis B virus core IgM antibody were negative in both EIAs. Comparison of results obtained for 37 serum samples revealed 14 positive by radioimmunoassay and 11 positive by both AgCEIA and AbCEIA. Both EIAs detected BKV IgM antibody in sera of renal allograft patients and patients on renal dialysis who had reactivated BKV infections persisting for several months after transplantation.
Haemophilus infection in a colony of laboratory rats
Authors: Nicklas W
Published: January 2020

During routine quality control of laboratory rodents, short gram-negative rods with satellite growth adjacent to a Staphylococcus strain were isolated from rats. They proved to be members of the family Pasteurellaceae. On the basis of their dependence on V factor they were classified as Haemophilus sp. Systematic investigations in our laboratory rat colony revealed a high prevalence of these bacteria. They were isolated from 75 of 446 rats (16.8%) which were monitored by culture during a 2-year investigation. Most strains were isolated from the lungs and the trachea; some were cultured from the nasal cavity and the female genital tract. Antibodies to these bacteria were detected in sera from 385 of 829 rats (46.5%) by using an indirect immunofluorescence test. The majority of culturally and serologically positive animals came from three separate holding areas; they all came from the same breeder. Investigation of rats immediately on receipt from the breeder showed that they were culturally and serologically positive for Haemophilus sp. Histological examination of rats which were monoinfected with Haemophilus sp. showed a mild inflammatory cell infiltration in the lungs and a light diffuse hyperemia. In the physiological and biochemical investigations of 53 isolates, all strains had an identical biochemical profile. On the basis of the 35 criteria examined, a definite classification is not possible. These Haemophilus bacteria are probably members of a hitherto unknown species.
T-mod pathway, a reduced sequence for identification of gram-negative urinary tract pathogens
Authors: Berlutti F , Thaller M C , Dainelli B , Pezzi R
Published: January 2020

In this paper, we describe a reduced sequence of identification that includes T-mod medium, a selective and differential isolation medium which allows accurate presumptive identification of the most common gram-negative bacteria encountered in urine samples. The present study, performed on bacteria isolated from 1,762 independent urine samples, has shown that a few selected tests (lysine and ornithine decarboxylase, urease and trehalose fermentation tests) improve the identification accuracy of T-mod, making it possible both to identify the less frequent species and to prevent some misidentifications of Klebsiella pneumoniae and Proteus mirabilis. The proposed work flow agreed with conventional identification protocols to a 99.3% extent and allowed identification of 87.4% of the isolates directly from the primary plate, 11.4% after 1 to 3 additional tests, and 1.2% after an identification gallery.
Laboratory diagnosis of pulmonary toxoplasmosis in patients with acquired immunodeficiency syndrome
Authors: Derouin F , Sarfati C , Beauvais B , Iliou M C , Dehen L , Lariviere M
Published: January 2020

In four cases of pulmonary toxoplasmosis occurring in patients with acquired immunodeficiency syndrome, Toxoplasma sp. was discovered in bronchoalveolar-lavage fluid (three cases) and in lung biopsy specimen (one case) by using the following methods: direct examination of smears stained with eosine-methylene blue fast stain, indirect immunofluorescence assay, and inoculation of MRC5 fibroblast cell line in tissue culture.
Development and testing of a synthetic oligonucleotide probe for the detection of pathogenic Yersinia strains
Authors: Miliotis M D , Galen J E , Kaper J B , Morris J G
Published: January 2020

A 24-base oligonucleotide probe specific for a region of the Yersinia enterocolitica virulence plasmid (pYV) associated with HEp-2 cell cytotoxicity and the Sereny reaction was constructed by using sequences flanking critical TnphoA insertions in a subcloned fragment of pYV. This probe, highly specific and sensitive for virulent yersiniae, detected pathogenic Y. enterocolitica isolates in artificially inoculated foods.
Rahnella aquatilis, an unusual gram-negative rod isolated from the bronchial washing of a patient with acquired immunodeficiency syndrome
Authors: Harrell L J , Cameron M L , O'Hara C M
Published: January 2020

Rahnella aquatilis, a rare enteric gram-negative rod which is usually found in fresh water, was isolated from the bronchial washing of a patient with acquired immunodeficiency syndrome. Although few clinical isolates have been reported, this is the second isolation of R. aquatilis from a human in North Carolina. A case report and discussion of R. aquatilis is presented.
Simultaneous detection of Escherichia coli heat-stable and heat-labile enterotoxin genes with a single RNA probe
Authors: Sáez-Llorens X , Guzman-Verduzco L M , Shelton S , Nelson J D , Kupersztoch Y M
Published: January 2020

A single RNA probe was synthesized and used to detect simultaneously the methanol-soluble heat-stable enterotoxin and heat-labile enterotoxin genes in Escherichia coli strains. The results with the biotinylated or radioactive probe correlated 100% with the biological assay results for both toxins. The RNA probe detected the three known heat-stable enterotoxin A alleles.
Detection of herpes simplex virus by using A549 cells in centrifugation culture with a rapid membrane enzyme immunoassay
Authors: Hursh D A , Wendt S F , Lee C F , Gleaves C A
Published: January 2020

The RAMP herpes simplex virus (HSV) culture confirmation test was compared with immunofluorescence (IF) staining with a specific HSV monoclonal antibody reagent for the detection of HSV in centrifugation culture. The RAMP test detected 47 of 57 IF-positive specimens (sensitivity, 88.6%) and agreed with 217 of 220 IF-negative specimens (specificity, 98.6%). The RAMP test can be performed in less than 15 min and gives an immediate visual result. However, the sensitivity and the false-positive and false-negative results need further investigation.
Elevated levels of immunoglobulin A to Giardia lamblia during a waterborne outbreak of gastroenteritis
Authors: Birkhead G , Janoff E N , Vogt R L , Smith P D
Published: January 2020

During an outbreak of diarrheal illness among residents of a trailer park in rural Vermont, 37 (30%) of 122 residents met the case definition of outbreak-related giardiasis. Convalescent-phase sera from 24 residents and 20 nonresident control subjects were tested by enzyme-linked immunosorbent assay for immunoglobulin G (IgG), IgM, and IgA antibodies to Giardia lamblia. Residents showed higher levels of parasite-specific antibody than did nonresident controls for IgG and IgA but not IgM. Nine residents with giardiasis had a higher median level of G. lamblia-specific IgA but not IgG or IgM than 15 healthy residents (0.61 versus 0.16 optical density units; P = 0.004). Moreover, parasite-specific IgA levels were higher in those consuming tap water than in those who did not (0.31 versus 0.08 optical density units; P = 0.03) and increased with increasing water consumption. Levels of serum antibody to G. lamblia, particularly IgA, may be useful in determining exposure to G. lamblia-contaminated water and illness from G. lamblia during waterborne outbreaks of diarrheal illness.
Rapid identification of Streptococcus bovis by using combination constitutive enzyme substrate hydrolyses
Authors: Panosian K J , Edberg S C
Published: January 2020

Several studies have documented the association of blood and rectal-culture positivity for Streptococcus bovis with gastrointestinal neoplasia, especially colonic carcinoma. Conventional methods using bile-esculin hydrolysis, salt tolerance, and sugar fermentations to differentiate S. bovis from other streptococci are laborious, slow, and relatively expensive. Commercially available systems are costly and require at least 24 to 48 h of incubation. A rapid identification procedure for S. bovis and related bacteria was developed. The method uses a reagent containing two hydrolyzable substrates, p-nitrophenyl-alpha-D-galactopyranoside and 4-methylumbilliferyl-beta-D-glucoside, in the presence of 2.5% sodium deoxycholate. This combination test, performed with a rapid assay for L-pyrrolidonyl-aminopeptidase, could distinguish S. bovis, Streptococcus equinus, Enterococcus spp., Streptococcus pneumoniae, and the viridans group streptococci in culture within 30 min. Twelve species of the genera Streptococcus and Enterococcus were tested. The rapid method correlated well with conventional techniques. The reagents are readily available, inexpensive, and easy to make and can be stored in the refrigerator for at least 6 months.
Detection of respiratory syncytial virus in nasopharyngeal secretions by DNA-RNA hybridization
Authors: Van Dyke R B , Murphy-Corb M
Published: January 2020

We have developed an RNA-cDNA hybridization assay for the detection of respiratory syncytial virus (RSV) RNA in nasopharyngeal samples. We chose to use as probe a cDNA complementary to the nucleocapsid protein gene of RSV, integrated into the plasmid vector pBR322. The lower limit of sensitivity of the assay is 8.2 X 10(2) PFU of the Long strain of RSV. In throat washes with added cell-free virus, the assay can detect 3.3 X 10(3) PFU of RSV. Respiratory secretions were collected from a group of 104 infants in New Orleans, and 73 of the samples were tested for RSV by immunofluorescence (IF). All were then frozen at -70 degrees C for later testing by hybridization, and 67 were tested for RSV antigens by enzyme immunoassay (EIA). A second set of respiratory secretions from 48 infants in Denver were cultured for virus, assayed for RSV antigen by EIA, and then frozen for later testing by hybridization. For those samples on which IF was performed, hybridization, compared with IF, had a sensitivity of 49% and a specificity of 66%. For samples tested by EIA, hybridization had a sensitivity of 60% and a specificity of 81% compared with EIA. Compared with virus isolation, hybridization assay had a sensitivity of 73% and a specificity of 92%. With clinical samples, the sensitivity and specificity of the assay were improved with the addition of a control blot, which was hybridized to the plasmid vector (pBR322). The performance of the hybridization assay can be expected to improve when the assay is used with fresh clinical material rather than frozen samples.
Direct and sensitive detection of a pathogenic protozoan, Toxoplasma gondii, by polymerase chain reaction
Authors: Burg J L , Grover C M , Pouletty P , Boothroyd J C
Published: January 2020

We applied the polymerase chain reaction to detection of the pathogenic protozoan Toxoplasma gondii based on our identification of a 35-fold-repetitive gene (the B1 gene) as a target. Using this procedure, we were able to amplify and detect the DNA of a single organism directly from a crude cell lysate. This level of sensitivity also allowed us to detect the B1 gene from purified DNA samples containing as few as 10 parasites in the presence of 100,000 human leukocytes. This is representative of the maximal cellular infiltration (10(5)/ml) in 1 ml of cerebrospinal fluid obtained from patients with toxoplasmic encephalitis. The B1 gene is present and conserved in all six T. gondii strains tested to date, including two isolates from patients with acquired immunodeficiency syndrome. No signal was detected by using this assay and DNAs from a variety of other organisms, including several which might be found in the central nervous system of an immunocompromised host. This combination of sensitivity and specificity should make detection of the B1 gene based on polymerase chain reaction amplification a very useful method for diagnosis of toxoplasmosis both in immunocompromised hosts and in congenitally infected fetuses.
New datum handling methods for the quality control of antibiotic solutions and plates used in the antimicrobial susceptibility test
Authors: McDermott S N , Hartley T F
Published: January 2020

Quality control programs are described for monitoring both the antibiotic solutions and the plates used in the dilution antimicrobial susceptibility test. For the quality control of antibiotic solutions, a simple comparative disk diffusion assay is used in which the data are expressed as zone ratios calculated from the following formula: zone ratios = mean zones of inhibition for disks impregnated with antibiotic under test/mean zones of inhibition of previously prepared quality control disks impregnated with the same antibiotic. The rejection limits set for this method are twice as stringent as for MIC estimation, and its precision is four times greater. For quality control of the antibiotic agar plates, fluid was absorbed directly into filter paper disks placed on the surface of the medium. These disks were then transferred to a seeded plate to produce zones of inhibition. These zones of inhibition were then converted to zone ratios by dividing the zone of inhibition for the individual antibiotics by the mean of the total zones of inhibition for all the antibiotics tested on the same plate. We further normalized these data by expressing each entry as a standard normal deviate calculated from the mean and standard deviation of the cumulative data for each individual antibiotic. The use of zone ratios reduced batch-to-batch variation, and standard normal deviate values gave a uniform result for convenience. The method has a sensitivity equal to that of an MIC estimation if it were possible to estimate the MICs of antibiotics at these low levels.
Levels of the Candida metabolite D-arabinitol in sera of steroid-treated and untreated patients with sarcoidosis
Authors: Wong B , Baughman R P , Brauer K L
Published: January 2020

We measured the Candida metabolite D-arabinitol and its enantiomer L-arabinitol in 42 serum samples from 33 patients with sarcoidosis and compared the results with those from 27 healthy adults and 4 patients with candidiasis. The D- and L-arabinitol concentrations and the D- and L-arabinitol/creatinine ratios did not differ significantly in the sarcoidosis patients and the controls; the D-arabinitol concentrations and the D-arabinitol/creatinine ratios were much higher in the patients with candidiasis. Among the patients with sarcoidosis, the D- and L-arabinitol levels in the steroid recipients did not differ significantly from those in patients not receiving steroids. Higher D-arabinitol/creatinine ratios were associated with roentgenographic evidence of pulmonary fibrosis and low forced vital capacities, but not with disease activity as determined by the proportion of lymphocytes to total nucleated cells in bronchoalveolar lavage fluid or the CD4/CD8 ratio in bronchoalveolar lymphocytes. We conclude that neither sarcoidosis nor corticosteroid treatment is associated with high levels of D-arabinitol in serum.
Use of nasal and pharyngeal swabs for rapid detection of respiratory syncytial virus and adenovirus antigens by enzyme-linked immunosorbent assay
Authors: Brůcková M , Grandien M , Pettersson C A , Kunzová L
Published: January 2020

Nasal and pharyngeal swabs from 134 children with acute respiratory diseases were examined for the presence of respiratory syncytial (RS) virus and adenovirus antigens by enzyme-linked immunosorbent assay (ELISA). The results were compared with those obtained by virus isolation and serology. Altogether, 56 RS virus-positive (prospective study), 51 adenovirus-positive (retrospective study), and 27 negative (prospective study) samples were examined. The sensitivities of ELISA were 96 and 98% for RS virus and adenovirus antigen detection, respectively. No false-positive results were observed. It is concluded that the joint eluate from a nasal and a pharyngeal swab, properly taken and handled, serves well for the detection of RS virus and adenovirus acute respiratory infections by ELISA.
Restriction enzyme analysis of plasmid DNA and bacteriophage typing of paired Staphylococcus aureus blood culture isolates
Authors: Hartstein A I , Morthland V H , Eng S , Archer G L , Schoenknecht F D , Rashad A L
Published: January 2020

We compared restriction enzyme analysis of plasmid (REAP) DNA profiling with bacteriophage typing for determination of similarities and differences among 50 pairs of Staphylococcus aureus blood isolates from patients with multiple positive blood cultures. Isolates from 17 pairs did not have detectable plasmids. Isolates from 33 pairs had plasmids classified into 17 distinct REAP DNA profiles. Paired isolates from 31 of these episodes were identical to one another. By phage typing, 35 pairs had strong lytic reactions to a phage(s), 9 pairs lacked strong reactions, and 6 pairs consisted of a strongly reactive isolate and an isolate with no strong reaction to a phage. When consolidated into 11 general phage groups, pairs from 44 of the 50 episodes were in the same general group. REAP DNA profiles were highly reproducible (99%), whereas phage typing was not. REAP DNA profiling is superior to phage typing as a technique for determining similarities and differences among S. aureus blood isolates.
Method for improved extraction of DNA from Nocardia asteroides
Authors: Loeffelholz M J , Scholl D R
Published: January 2020

In a variation of standard DNA extraction methods, Nocardia asteroides was repeatedly exposed to sodium dodecyl sulfate at 60 degrees C for 30 min; each extraction was followed by centrifugation, removal of the nucleic acid-rich supernatant, and suspension of the cell pellet in fresh sodium dodecyl sulfate. The pooled supernatants contained a substantially higher amount of DNA than the first supernatant alone. The possible implications of this procedure on the development of DNA probes are discussed.
Modification of shell vial centrifugation method for detection of herpes simplex virus
Authors: Lin S Y
Published: January 2020

The shell vial centrifugation method for the detection of herpes simplex virus was modified with the addition of maintenance medium before specimen inoculation rather than after. Sensitivity and specificity values were comparable to those obtained with postcentrifugation medium addition.
Molecular epidemiology of Vibrio cholerae in Hong Kong
Authors: Yam W C , Lung M L , Ng K Y , Ng M H
Published: January 2020

We studied restriction fragment length polymorphism of the enterotoxin genes of isolates of Vibrio cholerae El Tor, indistinguishable by bacteriophage typing, which were collected in Hong Kong since 1978. Using this approach, we could distinguish indigenous and exogenous strains obtained from different sources and epidemiological settings.
Evaluation of the Du Pont HERPCHEK herpes simplex virus antigen test with clinical specimens
Authors: Wu T C , Zaza S , Callaway J
Published: January 2020

The HERPCHEK herpes simplex virus (HSV) antigen test (Du Pont, Billerica, Mass.) is a biotinstreptavidin-amplified enzyme-linked immunoassay for the detection of HSV antigen directly in clinical specimens. In a total of 200 mucocutaneous specimens, predominantly lesions from nongenital sites, HERPCHEK had a sensitivity of 90% and a specificity of 99% compared with the shell vial tissue culture method which uses primary rabbit kidney cells. Five false-negative results by HERPCHEK were found with specimens that contained a low percentage of positive cells by the direct immunoperoxidase stain used in a tissue culture method (1 to 9%). The absorbance values of the clinical specimens by the HERPCHEK test do not correlate well with the percentage of positive cells. Our results indicate that the HERPCHEK HSV antigen test, when performed with specimens from lesions, is a sensitive and specific test as compared with shell vial culture.
Application of numerical systematics to the phenotypic differentiation of legionellae
Authors: Fox K F , Brown A
Published: January 2020

A total of 163 strains, including 106 strains of Legionella pneumophila, 28 strains of Tatlockia micdadei, and 29 strains of other legionellae (including members of the proposed genus Fluoribacter), were studied. Ten tests which together could distinguish the genera previously proposed were identified. These tests included catalase-peroxidase, gelatinase, hippurate hydrolysis, starch hydrolysis, medium browning, acetoin production, oxidase, medium fluorescence, colony fluorescence, and the bromcresol purple spot test. T. micdadei strains were strongly catalase positive and bromcresol purple spot test positive and produced acetoin but otherwise were usually inert in the other tests. L. pneumophila and Fluoribacter species could usually be distinguished by strength of catalase activity, blue-white colony fluorescence (if present), and differences in frequency of hippurate hydrolysis, starch hydrolysis, yellow-green medium fluorescence, and, to a lesser extent, oxidase activity. With a simple algorithm and computer program, the overall accuracy was 98.8%.
Subgroup and serotype distributions of human, bovine, and porcine rotavirus in Thailand
Authors: Pongsuwanne Y , Taniguchi K , Choonthanom M , Chiwakul M , Susansook T , Saguanwongse S , Jayavasu C , Urasawa S
Published: January 2020

The subgroup and serotype specificities of human, bovine, and porcine group A rotaviruses in stool specimens collected in Thailand were examined by an enzyme-linked immunosorbent assay by using subgroup- and serotype-specific monoclonal antibodies. A clear yearly change was observed in the serotype distribution of human rotavirus. Between 1983 and 1984, serotype 4 was the most prevalent, while the highest frequency of serotype 2 was found between 1987 and 1988. All the bovine and porcine rotaviruses examined showed subgroup I specificities and long RNA patterns. It was of note that serotype 3 porcine rotaviruses were found at a high frequency.
Plaque assay for virulent Legionella pneumophila
Authors: Fernandez R C , Lee S H , Haldane D , Sumarah R , Rozee K R
Published: January 2020

Methods of assessing virulence of Legionella pneumophila, the etiologic agent of Legionnaires disease, include the infection of guinea pigs, fertile chicken eggs, and mammalian and protozoan cell cultures. Guinea pig assays, in particular, are expensive, laborious, or unsuitable for routine screening of Legionella isolates. We have developed a virulence assay that requires the enumeration of viruslike plaques which are the result of virulent L. pneumophila infecting mouse L929 cells. Each plaque is the consequence of the initial infection of an L cell with a single bacterium. A nonvirulent mutant derived from the serial passage of virulent L. pneumophila on Mueller-Hinton agar fails to survive within L cells and consequently fails to produce plaques.
False-positive result in Limulus test caused by Limulus amebocyte lysate-reactive material in immunoglobulin products
Authors: Ikemura K , Ikegami K , Shimazu T , Yoshioka T , Sugimoto T
Published: January 2020

Limulus amebocyte lysate (LAL)-reactive material other than endotoxin was detected in the plasma and urine of patients after intravenous immunoglobulin therapy. Thirty-seven vials of six different immunoglobulin products were analyzed for the LAL-reactive material by combined use of a conventional chromogenic Limulus test and a chromogenic endotoxin-specific test. The amount of LAL-reactive material in reconstituted immunoglobulin solutions ranged from a mean (standard deviation) of 10.2 (2.1) to 2,448.1 (988.9) pg/ml, and there were statistically significant differences among the six brands. The levels of LAL-reactive material in plasma increased in proportion to the amounts contained in the immunoglobulin products administered. The material accumulated in the blood with repeated administration. Urinary excretion of the material was less than 5% of the total amount administered. Such material seems to be derived from the cellulose-based membranes used during preparation of the blood products. Thus, interpretation of Limulus test results of patients receiving immunoglobulin therapy requires special consideration.
Usefulness of trehalose fermentation and L-glutamic acid decarboxylation for identification of biochemically aberrant Providencia stuartii strains
Authors: Fischer R , Penner J L , Zurinaga G , Riddle C , Sämisch W , Brenner D J
Published: January 2020

A total of 849 Providencia isolates were collected during a 4-year period when an increased incidence of nosocomial Providencia stuartii infection was noted in urologic wards. Of these isolates, 630 were identified as P. stuartii, 206 were identified as Providencia rettgeri, and 1 was identified as Providencia alcalifaciens. Twelve inositol-positive isolates from 10 patients (10 strains) resembled P. stuartii in fermenting trehalose but resembled P. rettgeri in fermenting D-arabitol or meso-erythritol or both. The latter traits, however, were not stable in all cases. These aberrant strains were identified as P. stuartii on the basis of their O antigens and DNA hybridization experiments. All isolates were tested for L-glutamic acid decarboxylase activity by a qualitative thin-layer chromatography method. All P. stuartii isolates, including the aberrant ones, were trehalose positive and L-glutamic acid decarboxylase negative. None of the P. rettgeri isolates fermented trehalose, while 99.0% of them and the single P. alcalifaciens strain were L-glutamic acid decarboxylase positive. Thus, trehalose fermentation and L-glutamic acid decarboxylation are more useful for separating P. stuartii from P. rettgeri than are D-arabitol and meso-erythritol fermentation.
Proteeae species bacteriuria accompanying Proteeae species groin skin carriage in geriatric outpatients
Authors: Ehrenkranz N J , Alfonso B C , Eckert D G , Moskowitz L B
Published: January 2020

There have been numerous reports of Proteeae species urinary tract infections among elderly individuals. To explore a possible urinary carrier source of Proteeae species in this population, the frequency of aerobic gram-negative bacillus (AGNB) bacteriuria at the greater than or equal to 10(2)/ml level was determined in 67 ambulatory elderly outpatients classified as to Proteeae group (Morganella, Proteus, Providencia) groin carriage by a set of two skin cultures obtained at least 1 week apart. None had urethral catheters, symptomatic infections, skin ulcers, or recent antibiotic therapy. We found AGNB bacteriuria in 12 of 15 carriers (80%) and in 21 of 52 noncarriers (40%) (P = 0.009). Proteeae species bacteriuria occurred in eight carriers (53.3%) and six noncarriers (11.5%) (P = 0.001). At the 10(2) to 10(4)/ml level, Proteeae species were isolated in urine specimens from seven carriers (46.7%) and four noncarriers (7.7%) (P = 0.001). There was concordance of species of skin and urine Proteeae isolates in six carriers. By contrast, non-Proteeae AGNB bacteriuria at any level was present in four Proteeae species carriers (26%) and 15 noncarriers (28.8%) (P greater than 0.05). There was a 36.7% frequency of Proteeae species bacteriuria in nursing home residents, in contrast to 8.1% among those living in private homes; this parallels the greater frequency of Proteeae species groin carriage among nursing home residents in the study population. Low-level urinary colonization with Proteeae species accompanying Proteeae species groin skin colonization in elderly individuals is a hitherto unrecognized finding. This may account for the greater frequency of Proteeae species urinary infections in this population.
Epidemic Pseudomonas aeruginosa serotype O16 bacteremia in hematology-oncology patients
Authors: Richet H , Escande M C , Marie J P , Zittoun R , Lagrange P H
Published: January 2020

From 1 August 1978 through 31 December 1982, 98 hematology-oncology patients had positive cultures for Pseudomonas aeruginosa serotype O16; 22 of these patients developed bacteremia, and this bacteremia was associated with the occurrence of extensive perineal cellulitis in 10 patients (45.5%). Seventeen bacteremic patients died. The epidemic strain differed from other P. aeruginosa organisms isolated at the hospital by its resistance to all antibiotics available at that time (ticarcillin, piperacillin, azlocillin, tobramycin, ceftizoxime, ceftriaxone, moxalactam, ceftazidime, and fosfomycin). Univariate analysis showed the following factors to be significantly associated with P. aeruginosa O16 bacteremia: the severity of granulocytopenia at the time of the bacteremia, more days with fever, the administration of ticarcillin or an aminoglycoside, the receipt of a greater number of antimicrobial agents for a longer period of time before documentation of the bacteremia, and the occurrence of cellulitis. Logistic regression analysis showed that duration of fever, duration of bacteremia, and the number of antimicrobial agents administered before documentation of the bacteremia were the best predictors of P. aeruginosa O16 bacteremia. In a prospective study of the acquisition of P. aeruginosa by hematology-oncology patients, 1,149 specimens (throat and rectal swabs) from 270 patients and 201 specimens from their washbasin drains were collected. On only three occasions was the epidemic strain isolated from both the patient and his or her washbasin, but in each case the colonization of the patient preceded the isolation of the strain from the washbasin. The transmission of any P. aeruginosa organism from washbasin drain to patient could not be documented. Contact isolation precautions from the Centers for Disease Control were used for all hematology-oncology patients colonized or infected with P. aeruginosa after 7 January 1983. No case of P. aeruginosa O16 bacteremia has occurred at Hotel Dieu since July 1984.
Tracheal tube biofilm as a source of bacterial colonization of the lung
Authors: Inglis T J , Millar M R , Jones J G , Robinson D A
Published: January 2020

Biofilm formation in tracheal tubes, its bacterial content, and its interaction with ventilator gas flow were investigated. At least 50 mg (dry weight) of biofilm was found in 30 of 40 tracheal tubes used in intensive care patients for 2 h to 10 days. Electron microscopy showed bacteria in this layer, and quantitative studies showed that bacterial counts could reach up to 10(6)/cm of tube length. Bacteria were cultured from the patient side of 18 of 78 heat and moisture exchanger-microbiological filter units removed from ventilator circuits. Particles were shown to detach from tracheal tube luminal biofilm and were projected up to 45 cm from the tracheal tube tip. Following contamination of the tracheal tube biofilm with a patient's own gastrointestinal flora, entrainment of bacteria in the inspiratory gas flow provides a mechanism for initial and repeated lung colonization.
Comparison of epidemiological marker methods for identification of Salmonella typhimurium isolates from an outbreak caused by contaminated chocolate
Authors: Kapperud G , Lassen J , Dommarsnes K , Kristiansen B E , Caugant D A , Ask E , Jahkola M
Published: January 2020

Plasmid profile analysis, restriction endonuclease analysis, and multilocus enzyme electrophoresis were used in conjunction with serotyping, bacteriophage typing, and biochemical fingerprinting to trace epidemiologically related isolates of Salmonella typhimurium from an outbreak caused by contaminated chocolate products in Norway and Finland. To evaluate the efficiency of the epidemiological marker methods, isolates from the outbreak were compared with five groups of control isolates not known to be associated with the outbreak. Both plasmid profile analysis and phage typing provided further discrimination over that produced by serotyping and biochemical fingerprinting. Plasmid profile analysis and phage typing were equally reliable in differentiating the outbreak isolates from the epidemiologically unrelated controls and were significantly more effective than multilocus enzyme electrophoresis and restriction enzyme analysis of total DNA. The greatest differentiation was achieved when plasmid profile analysis and phage typing were combined to complement serotyping and biochemical fingerprinting. However, none of the methods employed, including restriction enzyme analysis of plasmid DNA, were able to distinguish the outbreak isolates from five isolates recovered in Norway and Finland over a period of years from dead passerine birds and a calf.
Quantitative assay of glycocalyx produced by viridans group streptococci that cause endocarditis
Authors: Dall L , Herndon B
Published: January 2020

A quantitative method to determine glycocalyx production by strains of viridans group streptococci from patients with endocarditis is presented. There is good correlation between this new tryptophan quantitative assay and qualitative assays employing polysaccharide stains (ruthenium red, periodic acid-Schiff, and Cellufluor) or the Molisch test. The quantification of the glycocalyx production in glucose substrate in vitro by viridans group streptococci correlates with the size of cardiac vegetation and ease of antimicrobial sterilization in experimental endocarditis. The relationship of in vitro quantification of glycocalyx to maintenance of infection, morbidity of infection, and antimicrobial treatment is discussed.
Colony immunoblot assay for the detection of staphylococcal toxic shock syndrome toxin 1 (TSST-1) with anti-TSST-1 F(ab')2 fragments
Authors: See R H , Adilman S , Bartlett K H , Chow A W
Published: January 2020

Toxic shock syndrome toxin 1 (TSST-1), an exoprotein of Staphylococcus aureus, is strongly implicated in the pathogenesis of TSS. Detection of TSST-1, however, is often hindered in immunoassays because of the cosecretion of protein A, a genetic trait which appears to be coordinately expressed with other exoproteins in S. aureus. We developed a colony immunoblot assay for rapid screening of TSST-1-producing S. aureus using TSST-1-specific rabbit F(ab')2 fragments. The sensitivity and specificity of this method were compared with those of a quantitative noncompetitive enzyme-linked immunosorbent assay (ELISA) for 34 S. aureus isolates (17 TSS-associated and 17 non-TSS-associated isolates). Cosecreted protein A in culture supernatants was evaluated by a quantitative competitive ELISA. The results clearly indicated the superiority of F(ab')2 fragments in eliminating nonspecific reactivity of protein A in the colony immunoblot assay. The sensitivity of the immunoblot with TSST-1-specific F(ab')2 was similar to that with whole immunoglobulin G (94 versus 82%, respectively; P = 0.601, Fisher's exact test), but the specificity was markedly improved (94 versus 59%, respectively; P = 0.039). Among TSST-1-negative isolates (as determined by ELISA), strains which gave false-positive results in the immunoglobulin G immunoblot assay produced higher amounts of protein A than strains which gave true-negative results (P = 0.08, Mann-Whitney rank sum test, one tailed). Among strains positive for TSST-1, the level of TSST-1 detected in culture supernatants correlated inversely with the amount of protein A secreted (rs = -0.64; P less than 0.01, Spearman rank correlation). These findings validate the utility of a rapid screening method for the detection of TSST-1-producing S. aureus and support the concept of coordinate secretion of exoproteins in S. aureus.
Line blot and western blot immunoassays for diagnosis of Mediterranean spotted fever
Authors: Raoult D , Dasch G A
Published: January 2020

The line blot, a new immunoassay in which antigens are placed on nitrocellulose as narrow lines, was evaluated for its sensitivity and specificity relative to the microimmunofluorescence assay for the diagnosis of Mediterranean spotted fever (MSF). The line blot assay was only slightly less sensitive and less specific than the microimmunofluorescence assay for detection of immunoglobulin M (IgM) or IgG in 100 serum specimens from 42 patients with MSF. No line blot reactions were observed among 50 control serum specimens from febrile patients with other illnesses. The line blot assay was largely group reactive for spotted fever rickettsiae, but 26% of the positive serum specimens also cross-reacted by IgM with Rickettsia typhi. Western immunoblotting was used to characterize the antigenic components recognized by 19 MSF serum specimens. For both IgM and IgG, lipopolysaccharide was the cross-reactive group antigen, whereas the high-molecular-weight species-specific protein antigens (SPAs) were the only reactive proteins. Relative to the other nine rickettsiae, Rickettsia bellii was unique both in exhibiting no SPA reactions and in having a lipopolysaccharide with a predominantly high-molecular-weight distribution. Although most of the 19 MSF serum specimens examined by Western blotting exhibited preferential reactivity to SPAs of two strains of R. conorii and weaker reactions to the other rickettsiae, 2 serum specimens exhibited SPA reactions consistent with typhus infections. In comparison with other assays, the line blot and Western blot immunoassays have advantages which may permit an improvement in the general availability and commercialization of assays for the serodiagnosis of rickettsial infections.
Optimization of a medium for the rapid urease test for detection of Campylobacter pylori in gastric antral biopsies
Authors: Goldie J , Veldhuyzen van Zanten S J , Jalali S , Hollingsworth J , Riddell R H , Richardson H , Hunt R H
Published: January 2020

We developed a buffered azide-free urea medium which is sensitive, specific, and nontoxic for rapid detection of Campylobacter pylori in gastric biopsies. Detection of urease produced by the organism provides the basis for the test. The substrate is urea in monobasic sodium phosphate buffer, and phenol red provides indication of the pH change that results from urease activity. A rapid change from yellow to red occurs in the presence of C. pylori, even at low concentrations of the organism. A slower color change occurs with higher concentrations of other urease producers, such as Yersinia enterocolitica and Proteus mirabilis. Experience with 51 patients with our medium showed excellent results in detection of C. pylori in gastric mucosal biopsies. In clinical research and practice, a rapid bedside test will be helpful for rapid diagnosis of C. pylori-positive patients.
False-positive results with third-generation monoclonal hepatitis B surface antigen enzyme immunoassay
Authors: Ratnam S , Stead F , Head C B
Published: January 2020

Nonspecific hepatitis B surface antigen reactions with a third-generation enzyme immunoassay (Auszyme Monoclonal; Abbott Laboratories, North Chicago, Ill.) were investigated with 9,577 serum specimens in a clinical laboratory setting. Of the 196 serum specimens found reactive in Auszyme screen by the overnight procedure, 103 turned out to be true-positives, 71 were nonrepeatably reactive, and 22 were repeatably reactive but actually falsely positive (false-positive rate, 22 of 196, or 11.2%). Verification of the 196 screen reactives by the Auszyme 3-h incubation assay detected all but 4 true-positives, with a false-negative rate of 3.9% (4 of 103), and was negative for the rest. These observations reinforce the need for retesting all reactive specimens and confirming repeatedly reactive samples when the Auszyme Monoclonal test is used to detect hepatitis B surface antigen.
Comparison of media for screening of diarrheic stools for the recovery of Clostridium difficile
Authors: Iwen P C , Booth S J , Woods G L
Published: January 2020

Recoveries of Clostridium difficile from stool specimens by using three media, cycloserine-mannitol agar (M-CMA), cycloserine-mannitol-blood agar (M-CMBA), and cycloserine-cefoxitin agar (M-CCA), were compared. Of 321 clinical specimens, 37 yielded C. difficile. Thirty-four were positive on M-CCA, 21 were positive on M-CMA, and 20 were positive on M-CMBA. M-CCA recovered significantly more C. difficile than did M-CMBA or M-CMA.
Identification of serotype 9 human rotavirus by enzyme-linked immunosorbent assay with monoclonal antibodies
Authors: Midthun K , Valdesuso J , Kapikian A Z , Hoshino Y , Green K Y
Published: January 2020

Hybridomas producing monoclonal antibodies to VP7, a major neutralizing protein of serotype 9 rotavirus (strain W161), were prepared. One monoclonal antibody, W161-6A1, was shown to neutralize only serotype 9 rotavirus strains and reacted specifically with serotype 9 rotaviruses in an enzyme-linked immunosorbent assay. The development of an immunoassay for detection of serotype 9 rotaviruses should facilitate epidemiologic studies.
Comparison of three kinds of blood and two incubation atmospheres for cultivation of Bordetella pertussis on charcoal agar
Authors: Hoppe J E , Schlagenhauf M
Published: January 2020

We compared the growth of Bordetella pertussis strains (n = 32) on antibiotic-free and cephalexin (40 micrograms/ml)-containing charcoal agar supplemented with 10% defibrinated horse blood, defibrinated sheep blood, or anticoagulant-containing human blood. Plates were incubated either in air or in an atmosphere with 5 to 10% CO2. As assessed by mean colony numbers and rapidity of growth, normal air was preferable to CO2 enrichment for incubation. Growth on horse blood agar was more abundant and more rapid than on sheep blood agar, but the difference in general was not statistically significant. Human blood was clearly inferior to both horse and sheep blood.
Mannose-resistant hemagglutination, enzyme-linked immunosorbent assay, and immune electron microscopy for detection of K99 fimbrial antigen in Escherichia coli from calves
Authors: Hernández F , Caballero M , Rivera P , Hird D
Published: January 2020

Mannose-resistant hemagglutination (MRHA) was evaluated for identification of Escherichia coli with K99 fimbriae. The sensitivity and specificity of MRHA, relative to the enzyme-linked immunosorbent assay, were 21 and 79%, respectively. Disagreement between the tests may have been due in part to separation of pili from the cells, with resultant enzyme-linked immunosorbent assay-positive, MRHA-negative tests. MRHA was not useful as the sole means for the identification of E. coli with K99 fimbriae.
Analysis of an outbreak of penicillinase-producing Neisseria gonorrhoeae in Rhode Island, 1987
Authors: Debuono B A , Opal S M , Sarafian S K , Lyhte L W
Published: January 2020

In June of 1987, an outbreak of penicillinase-producing Neisseria gonorrhoeae (PPNG) occurred in Rhode Island. PPNG persists as an endemic pathogen despite a concerted statewide effort to eradicate the organism. Detailed analysis of PPNG isolates demonstrated that multiple strains are circulating concurrently, complicating control measures.
Identification of monounsaturated fatty acids of Aerococcus viridans with dimethyl disulfide derivatives and combined gas chromatography-mass spectrometry
Authors: Moss C W , Wallance P L , Bosley G S
Published: January 2020

Location of the double-bond position of monounsaturated fatty acids of Aerococcus viridans was accomplished by combined gas chromatography (GC)-mass spectrometry analysis of dimethyl disulfide (DMDS) derivatives. The monoenoic fatty acids from whole bacterial cells were converted to methyl esters and then to DMDS adducts and analyzed by capillary GC-mass spectrometry. The mass spectra of DMDS adducts gave an easily recognizable molecular ion (M+) and two major diagnostic ions attributable to fragmentation between the two CH3S groups located at the original site of unsaturation. Two relatively novel acids that distinguish aerococci from bacteria of closely related genera were identified as C16:1 omega 9c and C16:1 omega 9t from their mass spectrometry fragmentation patterns and retention characteristics on nonpolar capillary GC columns.
Use of terpene-based solvents (Hemo-De, Histoclear, and Shandon and BDH xylene substitutes) in place of xylene in the Ehrlich indole test
Authors: Gubash S M , Bennett E E
Published: January 2020

Although less effective than xylene and Kovacs reagent as indole extractants, Hemo-De and Shandon xylene substitute can be used in the Ehrlich indole test if a less toxic solvent is desirable. In doubtful cases, xylene should be used. Because of the blocking action shown in the test, use of indole-nitrite broth cannot be recommended.
Humoral circulatory immune response to Gardnerella vaginalis
Authors: Ghione M , Clerici P A , Piragine G , Magliano E
Published: January 2020

Strain-specific circulating immunoglobulin G and/or M was detected by enzyme-linked immunosorbent assay and immunofluorescence test by using Formol-treated suspensions of Gardnerella vaginalis from 28 women with overt vaginitis but only three symptom-free subjects among 43 otherwise healthy women found to be colonized by G. vaginalis. Analogous but less stringent strain specificity patterns were elicited by immunization of BALB/c mice.
Problems with the disk diffusion test for detection of vancomycin resistance in enterococci
Authors: Swenson J M , Hill B C , Thornsberry C
Published: January 2020

A total of 53 strains of enterococci, including recently isolated strains with high-level resistance to vancomycin, were tested for vancomycin susceptibility by broth microdilution and disk diffusion using Mueller-Hinton media with and without supplementation with 5% blood. By using currently published parameters of the National Committee for Clinical Laboratory Standards for the disk diffusion test, we found that strains for which MICs were 8 to 32 micrograms/ml were incorrectly placed in the susceptible or intermediate category, which caused both very major (1.9%) and minor (11.5%) errors. When we used newer, recently proposed breakpoints for vancomycin, we found 13.5% minor errors but no very major errors. Changing disk diffusion breakpoints to less than or equal to 14 mm for resistant [corrected] and greater than or equal to 15 mm for susceptible [corrected] would eliminate the problem for the strains with MICs of 32 micrograms/ml but not for those with MICs of 8 micrograms/ml. For those strains, it is necessary to perform an MIC test to differentiate them from strains with MICs of less than or equal to 4 micrograms/ml.
Bacteremia detected by lysis direct plating in a neonatal intensive care unit
Authors: Phillips S E , Bradley J S
Published: January 2020

The density of bacteremia was determined in 787 neonatal blood specimens by using the 1.5-ml Isolator microbial tube. Coagulase-negative staphylococci were the organisms isolated most frequently from both true-positive cultures (25 of 50) and contaminated cultures (57 of 131). Based on the first positive culture in an episode of sepsis, there were no cases of coagulase-negative staphylococcal sepsis associated with counts of less than or equal to 5 CFU/ml. Indwelling intravascular lines were associated with the majority of the episodes of sepsis. The distribution of pathogens causing sepsis in this neonatal population was similar to the distribution of microorganisms associated with cannula-related sepsis in other hospitalized patients.