bluuebunny/crossref_metadata_2025 huggingface dataset:
Close association of verotoxin (Shiga-like toxin) production with enterohemolysin production in strains of Escherichia coli
Authors: Beutin L , Montenegro M A , Orskov I , Orskov F , Prada J , Zimmermann S , Stephan R
Published: January 2020

Sixty-four verotoxin-producing (VT+) Escherichia coli strains were analyzed for VT1- and VT2-specific DNA sequences and for production of hemolysin. Strains of human origin were of the following serotypes: O157:H7 or H-, O111:H8 or H-, O26:H11, O114:H4, and rough:H7. Strains of serotypes O157:H7, O113:H21, O116:H21, and rough:H- were from cattle, while those of serotype O139:K12:H1 were from pigs. All 64 isolates carried either VT1 or VT2 or both genes. Sixty of the strains (93.8%) were hemolytic (Hly+). The three O139:K12:H1 strains examined produced alpha-hemolysin, as shown by their reaction with the alpha-hemolysin-specific monoclonal antibody h2A and by DNA hybridization with an alpha-hly gene probe. The remaining 57 Hly+ strains (95%) produced a different type of hemolysin (enterohemolysin), which is genetically and serologically unrelated to alpha-hemolysin. The two types of hemolysin are further distinguished by the appearance of the lysis zone on blood agar and by the time interval for the detection of hemolysis. In contrast to alpha-hemolysin, enterohemolysin can be detected only on blood plates containing washed erythrocytes. The frequent association of enterohemolysin with verotoxin production (89%) makes it useful as an epidemiological marker for rapid and simple detection of potential VT+ E. coli.
Detection of enzymatically amplified human immunodeficiency virus DNA by oligonucleotide solution hybridization and by incorporation of radiolabeled deoxynucleotides
Authors: Carman W F , Williamson C
Published: January 2020

Two methods are described for the detection of in vitro enzymatically amplified DNA. The first method involves solution hybridization of labeled oligonucleotides to amplified products. Hybridization of primers to a dilution series of known concentration of amplified DNA showed that approximately 5 pg of DNA could be detected by this method. In the second method, radiolabeled deoxynucleotides were incorporated into the elongating DNA chain. Both methods were able to detect amplified products 10 cycles before detection by ethidium bromide staining. Some variations of these techniques are discussed.
Monoclonal antibody-based enzyme immunoassay for Giardia lamblia antigen in human stool
Authors: Stibbs H H
Published: January 2020

A visually readable monoclonal antibody-based antigen-capture enzyme immunoassay for the detection of Giardia lamblia antigen in human stool specimens was developed and found to be 97% (30 of 31 stool specimens) sensitive for formalinized stools and 82% (49 of 60 stool specimens) sensitive for unfixed stool specimens by visual reading. The storage of specimens in 10% Formalin resulted in increased absorbance in 20 of 26 G. lamblia-positive specimens tested as both formalinized and unfixed specimens; the increase averaged 1,336%. The assay was specific for antigens of this organism and for antigens derived from the cyst, as opposed to the trophozoite, stage. The assay could detect the antigens of five cysts per well, but could not detect antigen in in vitro-cultured trophozoites. A mouse monoclonal antibody of the immunoglobulin G1 (IgG1) subclass, which was prepared against cysts of G. lamblia, was used as the solid-phase capture antibody. The antibody was reactive with the cyst wall, as determined by immunofluorescence. Polyclonal rabbit anti-cyst IgG was used as the secondary antibody, and peroxidase-labeled goat anti-rabbit IgG was used as the tertiary antibody in the assay format. Maximal capture of antigen from stool specimens occurred by 30 min. Optimal dilution of specimens was in the range of 1:60 to 1:600. Preliminary characterization of affinity-purified antigen recognized by the monoclonal antibody showed that it is heat stable (100 degrees C, 12 min) and resistant to sodium periodate treatment and that it may exist in multiple molecular weights from 45,000 to 110,000.
Use of a pilin gene probe to study molecular epidemiology of Pseudomonas aeruginosa
Authors: Speert D P , Campbell M E , Farmer S W , Volpel K , Joffe A M , Paranchych W
Published: January 2020

Strains of Pseudomonas aeruginosa from patients with cystic fibrosis (CF) are unusual. The majority have a rough lipopolysaccharide (LPS) which renders them nontypeable by conventional typing systems based on a serological reaction with the O polysaccharide of smooth LPS. We developed a new typing scheme using a pilin gene probe as a marker for hybridization with endonuclease-digested genomic DNA from P. aeruginosa. Twenty-one different restriction fragment length polymorphism (RFLP) types were found among 249 isolates. RFLP type 7 was recovered only from patients with thermal burns (9 of 14 isolates) in both Vancouver, British Columbia, and Edmonton, Alberta, Canada. None of the other RFLP types showed a clear predilection for disease state or environmental niche. Multiple morphologically different isolates from individual patients with CF were studied; each isolate in 33 of 40 sputum samples had an identical RFLP type, despite considerable LPS serotype heterogeneity. Sequential isolates from 23 patients were studied; in 10 isolates there was a clear change in both the RFLP and the LPS serotype. We conclude that patients with CF usually harbor a single P. aeruginosa RFLP type in their sputa, but that one strain can replace another as the predominant colonizing type.
Eikenella corrodens cellulitis and arthritis of the knee
Authors: Flesher S A , Bottone E J
Published: January 2020

Severe cellulitis and septic arthritis due to Eikenella corrodens and a viridans group streptococcus developed following dental manipulation in a patient with a history of hemarthrosis. Correct diagnosis was achieved by recognition of E. corrodens on a culture of a knee aspirate. Antimicrobial (ampicillin) therapy resulted in a therapeutic response.
Subgrouping of Pseudomonas cepacia by cellular fatty acid composition
Authors: Mukwaya G M , Welch D F
Published: January 2020

The cellular fatty acid compositions were determined for 42 strains of Pseudomonas cepacia from five cystic fibrosis centers in North America. All isolates contained significant (20%) amounts of hexadecanoic (C16:0), and cis-9 hexadecenoic (C16:1 cis9) acids and an isomer of octadecenoic acid (C18:1). None had hydroxy acids containing fewer than 14 carbon atoms. The quantitative data from the fatty acid analysis were highly reproducible and provided a basis for numerical analysis. Five subgroups comprising all the strains were obtained by cluster analysis and further characterized by principal-component analysis. With minor exceptions, the predominant subgroup identified in each center was different from that identified in other centers and accounted for one-half of the isolates within each center. Cellular fatty acid composition is a useful adjunct to biochemical characterization for the identification of P. cepacia isolated from cystic fibrosis patients. Numerical analysis of the fatty acid data can separate P. cepacia into subgroups, which may provide useful epidemiologic information or a basis for further analysis by more complex techniques such as DNA probe analysis.
Comparison of immunoblotting with other serological methods and virus isolation for the early detection of primary cytomegalovirus infection in allograft recipients
Authors: Miller H , McCulloch B , Landini M P , Rossier E
Published: January 2020

Sequential specimens from nine allograft recipients were examined by using a variety of methods to detect primary cytomegalovirus (CMV) infection as rapidly as possible posttransplantation. Sera were examined for immunoglobulin G (IgG) and IgM antibodies by immunoblotting, enzyme immunoassay, and immunofluorescence and also by complement fixation, latex agglutination, and an immunofluorescence test for antibody to CMV early antigen. Urine and occasionally blood, tissue, and other specimens were centrifuged onto cell cultures to enhance CMV infectivity. Eight of the nine patients showed laboratory evidence of primary CMV infection, and CMV was isolated from seven of the eight: in no case was virus isolated before seroconversion had become evident. However, serological tests differed in their abilities to detect antibody response to CMV infection in different patients; while immunoblotting, latex agglutination, and enzyme immunoassay for IgG antibodies generally detected seroconversion before complement fixation, this was not invariably the case. At present, optimal laboratory detection of CMV infections in these patients can be achieved only by a combination of serological methods and virus isolation.
Improved O-serotyping method for Serratia marcescens
Authors: Gaston M A , Pitt T L
Published: January 2020

In a previous study, we found that some O serotypes of Serratia marcescens, as defined by agglutination tests, were not based on lipopolysaccharide (LPS) O antigens. We developed a dot enzyme immunoassay with a high degree of LPS specificity and tested 104 distinct clinical strains. Only 7 of the 24 existing O antigens were found in more than one strain: O12/O14 (30.8% of strains examined), O21 (12.5%), O8 (8.7%), O6/O7 (5.8%), O4 (3.8%), O18 (2.9%), and O9 (2.9%). Two new antigens, S1254 (13.5%) and S3255 (3.8%), were also found. Agglutination tests with O antisera identified the LPS antigen in only 36 strains. Prodigiosin production was restricted to serotypes O8, O6, and S3255 and strains with a rough or semirough LPS phenotype. Dot immunoassay appears to offer greater accuracy than agglutination tests for serotype identification in S. marcescens.
Endotoxin removal by end-line filters
Authors: Vanhaecke E , De Muynck C , Remon J P , Colardyn F
Published: January 2020

Four commonly used end-line filters, one with a charge-modified hydrophilic nylon filter (ELD96; Pall Biomedical Ltd., Portsmouth, United Kingdom), one with an unmodified nylon filter (FAE020; Pall Biomedical), and two with hydrophilic cellulose ester filters (Ivex-HP, Millipore Corp., Bedford, Mass.; Sterifix, Braun-Gelman, Brussels, Belgium), were evaluated for their endotoxin-removing capacity in saline and 5% glucose. Natural endotoxins derived from Escherichia coli 8739 and the lipopolysaccharide mutant Pseudomonas aeruginosa PA220-R2 and a purified E. coli serotype O111:B4 lipopolysaccharide preparation were used to challenge the four end-line filters. No endotoxin-removing capacity was observed for the Ivex-HP and Sterifix filters. Both the FAE020 and the ELD96 end-line filters showed excellent endotoxin-eliminating capacities in 5% glucose. Increasing the NaCl concentration in 5% glucose, however, greatly reduced the endotoxin-removing efficiency of especially the ELD96 filter for the purified E. coli lipopolysaccharide preparation. Obviously, both the nature of the endotoxin and the ionic strength of the solution had a major influence on the endotoxin end-line filtering efficiency.
Relationship among selected Leptospira interrogans serogroups as determined by nucleic acid hybridization
Authors: Nielsen J N , Armstrong C H , Nielsen N C
Published: January 2020

Leptospiral DNAs from a variety of Leptospira interrogans serogroups of veterinary significance, as well as a nonpathogenic leptospira, were compared by Southern blot hybridization of EcoRI-digested genomic DNA. The serogroups examined could be assigned to one of three groups on the basis of the degree of cross-hybridization between genomic DNAs. Only a few restriction fragments hybridized between the three groups, and most of these were shown to contain ribosomal DNA. The restriction fragment length polymorphism observed among the intergroup hybridizations allowed differentiation among serogroups and, in some cases, serovars. Under the hybridization conditions used, no hybridization was observed between leptospiral DNA and Leptonema, Escherichia coli, or porcine DNA.
Cloned DNA probes identify Anaplasma ovis in goats and reveal a high prevalence of infection
Authors: Shompole S , Waghela S D , Rurangirwa F R , McGuire T C
Published: January 2020

Anaplasma organisms are observed in erythrocytes from goats with anemia and weight loss in Kenya. Three anaplasmas have been isolated in nature, Anaplasma ovis, Anaplasma marginale, and Anaplasma centrale. The two recognized species, A. ovis and A. marginale, are known to infect goats. Since only A. ovis causes clinical disease in goats, the Anaplasma species in goats in Kenya were identified. To detect A. ovis, a 9.6-kilobase-pair section of genomic DNA was cloned into pBR322 (pAO12A) and was used in conjunction with an A. marginale DNA probe previously derived from a gene coding for a 105,000-molecular-weight surface protein (Am105L) of A. marginale. In Southern blots, pAO12A DNA hybridized to several at least partially homologous sequences that were present in A. ovis and A. marginale genomic DNAs. The pAO12A DNA did not hybridize to Babesia bovis genomic or goat leukocyte DNA. The Anaplasma species that infected goats was identified as A. ovis by (i) DNA hybridization with pAO12A, (ii) hybridization of the A. marginale DNA probe to A. centrale and A. marginale genomic DNAs and lack of hybridization to A. ovis genomic DNA from an isolate obtained in Idaho and Anaplasma DNA from infected goats in Kenya, (iii) the intraerythrocytic location of Anaplasma organisms in infected goat blood, and (iv) the host specificity of the Anaplasma organisms for goats but not for cattle. Also, by using the two Anaplasma DNA probes, the prevalence of A. ovis in goats from seven locations in Kenya was found to range from 22 to 87%. The pAO12A DNA probe detected a 0.0035% A. ovis parasitemia in infected blood, an improved sensitivity which is suitable for use in surveillance and epidemiological studies.
Screening of type Ia and Ib Streptococcus agalactiae strains with high sialic acid levels by determination of susceptibility to tetracyclines
Authors: Nagano Y , Nagano N , Takahashi S , Suzuki A , Okuwaki Y
Published: January 2020

The type-specific capsular polysaccharide antigen of Streptococcus agalactiae is recognized to be an antiphagocytic factor in strains having large amounts of it. In the present study, it was indicated that vaginal isolates of types Ia and Ib could be classified into two groups on the basis of both their levels of the sialic acid, which occupies the terminal side chains of the polysaccharide, and their susceptibility to tetracyclines: one group comprised strains with low sialic acid levels (less than 9 micrograms/mg of cell dry weight) as well as with susceptibility to tetracyclines (MIC, less than or equal to 0.5 micrograms/ml), and the other comprised strains with higher sialic acid levels (greater than or equal to 9 micrograms/mg) and resistance to tetracyclines (MIC, greater than or equal to 8 micrograms/ml). A few isolates were found to have low levels of sialic acid and to be resistant to tetracyclines, but no isolates that were both relatively high in sialic acid and susceptible to tetracyclines were ever detected. Among strains of those serotypes, the MICs of tetracyclines were not in proportion to the sialic acid levels and were not affected when the sialic acid levels of each strain were altered by using Todd-Hewitt broth with various concentrations of Na2HPO4 and glucose. It was, therefore, apparent that the correlation of sialic acid levels with susceptibility to tetracyclines was not related directly to the sialic acid content or to the amount of the capsular polysaccharide. Since no plasmid DNAs were detected among representative strains that were tetracycline resistant, it was apparent that at least for the strains tested, resistance was chromosomal gene associated. In strains of S. agalactiae of types of Ia and Ib, the determination of susceptibility to tetracyclines was considered to be useful for screening strains with higher sialic acid levels.
Rapid screening for Staphylococcus aureus infection by measuring enterotoxin B
Authors: Hosotsubo K K , Hosotsubo H , Nishijima M K , Nishimura M , Taenaka N , Yoshiya I
Published: January 2020

We developed a simple, sensitive laser nephelometric assay (LNA) to detect circulating staphylococcal enterotoxin B (SEB). This assay yields the result within 2 h and needs no special treatment. Influence of protein A, a product generated by Staphylococcus aureus, was negligible in this assay. The levels of SEB in plasma were measured in 28 patients with and without S. aureus infection with the LNA. The levels of SEB in plasma increased significantly in patients with S. aureus infection. We also demonstrated that the levels of SEB in plasma were higher in patients with methicillin-resistant S. aureus infection than in patients with nonresistant staphylococcal infection. Our data indicate that LNA is a useful assay in the early diagnosis of methicillin-resistant S. aureus infection.
Preparation of filamentous hemagglutinin from Bordetella pertussis and assay for serum antibodies to filamentous hemagglutinin and pertussis toxin for clinical and public health laboratories
Authors: Wong K H , Skelton S K
Published: January 2020

A procedure that is sufficiently simple and economical for use in clinical and public health laboratories for producing and purifying filamentous hemagglutinin (FHA) and determining antibodies to this major antigen of Bordetella pertussis in serum is described. High yields of FHA (40 to 80 mg/liter) were obtained in the supernatant by cultivating B. pertussis in modified CL medium. The FHA antigen was separated from pertussis toxin (PT) and other antigens by chromatography on hydroxylapatite. Removal of residual PT activity in the FHA fraction was effected by affinity absorption of PT with Fetuin immobilized to Sepharose 4B. The FHA was used as the antigen for determining titers of immunoglobulin G (IgG), IgA, and IgM to FHA in sera of patients with pertussis by an improved enzyme-linked immunosorbent assay. Development of the interfering background color commonly observed in conventional FHA enzyme-linked immunosorbent assay procedures was eliminated by washing the reaction wells with a buffer of high ionic strength before adding the peroxidase conjugates. In the absence of nonspecific background color, the reaction endpoints were easy to read. The FHA prepared by the procedure described was identical to a reference preparation of purified FHA in sodium dodecyl sulfate-polyacrylamide gel electrophoresis profiles and serological specificity assays. High yields of FHA were obtained from all four strains of B. pertussis tested in this study, indicating that the procedure for enhanced production of FHA may be generally applicable to other strains of B. pertussis. Results from tests of 50 serum specimens with clinical information on pertussis for FHA and PT antibodies by the assay procedures described exemplified the usefulness and caveats of serodiagnosis for pertussis.
TestPack Chlamydia, a new rapid assay for the direct detection of Chlamydia trachomatis
Authors: Coleman P , Varitek V , Mushahwar I K , Marchlewicz B , Safford J , Hansen J , Kurpiewski G , Grier T
Published: January 2020

TestPack Chlamydia (Abbott Laboratories) is a rapid enzyme immunoassay for the direct antigen detection of Chlamydia trachomatis in endocervical specimens. The assay is self-contained, requires no specialized equipment, and yields results in less than 30 min. The clinical performance of TestPack Chlamydia versus chlamydial cell culture was evaluated with a total of 1,694 paired endocervical specimens. Discordant samples were further investigated by immunofluorescent staining and by Chlamydiazyme immunoassay, with confirmatory procedures. The sensitivity of TestPack Chlamydia with less-than-48-h-old specimens was 76.5%, while culture sensitivity was 86.7%. TestPack Chlamydia specificity was determined to be 99.5%. These results indicate that TestPack Chlamydia is an accurate test for chlamydial infection, with a positive predictive value of 96.2%. This assay is suitable for low-volume chlamydial testing in physician offices, clinics, and smaller laboratories.
Temporal and geographical distributions of human rotavirus serotypes, 1983 to 1988
Authors: Beards G M , Desselberger U , Flewett T H
Published: January 2020

Between 1983 and 1988, subgroups and serotypes were determined for 907 of 1,084 clinical specimens of rotaviruses collected in various countries of Europe, North and South America, Africa, and Asia. Enhanced enzyme immunoassays based on monoclonal antibodies specific for rotavirus proteins VP6 and VP7 were used. Significant differences in the prevalent serotypes were detected from year to year in the United Kingdom and Brazil and also in different countries during the same year. Throughout the study, rotavirus serotype 1 was detected most often (53.8%), followed in frequency by serotype 2 (17.8%), serotype 3 (12.1%), serotype 4 (11.1%), and serotypes other than 1 to 4 (5.1%). No individual serotype was found to predominate consistently in any one location. In the United Kingdom, rotavirus serotypes varied in prevalence in a regular but not predictable way. We suggest that a similar epidemiology might be found in other settings. Seventeen unusual strains were detected. Of these, five strains did not react with reference monoclonal antibodies specific for subgroup I and subgroup II, but they reacted with rotavirus group A-specific polyclonal and monoclonal antibodies; four strains were of subgroup II, serotype 2, and at least one had a "long" electropherotype; two strains were of subgroup I, serotype 2 with a long electropherotype; and one strain was of subgroup I, serotype 3. Five group C rotaviruses were detected.
Isoenzyme analysis of typhoid-Shigella and Escherichia-Shigella hybrid vaccines and their parental strains
Authors: Schultz C
Published: January 2020

Isoenzyme analysis can be used to measure phenotypic changes and to characterize bacterial strains. The use of isoenzyme analysis to characterize bacterial hybrid vaccine strains that were prepared for human vaccination is described in this report. The hybrid vaccine strains were two lots of Salmonella typhi-Shigella sonnei vaccine, two lots of Escherichia coli-Shigella flexneri vaccine, and their parental strains. The two lots of S. typhi-S. sonnei hybrid vaccine had only 5 of 11 reactive isoenzymes in common. The lot of S. typhi-S. sonnei hybrid vaccine that protected human volunteers in a clinical trial also had a greater degree of relatedness to the parental strain, S. typhi Ty21a, than the nonprotective lot. The two lots of E. coli-S. flexneri vaccine were more similar in terms of their isoenzyme profiles. There were colonial isolates from both lots that had identical isoenzyme profiles. The results also indicate a greater degree of homogenicity between Shigella spp. and E. coli than between either of these species and Salmonella spp. The data also show more isoenzyme activity associated with the nonpathogenic bacteria than with pathogenic isolates. Isoenzyme analysis is a rapid and specific assay that can be used to evaluate bacterial vaccine organisms and to establish isoenzyme profiles associated with vaccine immunogenicity and efficacy.
Detection of the 43,000-molecular-weight glycoprotein in sera of patients with paracoccidioidomycosis
Authors: Mendes-Giannini M J , Bueno J P , Shikanai-Yasuda M A , Ferreira A W , Masuda A
Published: January 2020

The 43,000-molecular-weight (43K) soluble glycoprotein was detected in sera of patients with paracoccidioidomycosis by the immunoblot technique by using as the probe rabbit monospecific antisera to this fraction. The 43K antigen was present before treatment in sera of patients with the acute (juvenile) form; it started to disappear from circulation after 10 months of chemotherapy, and it was undetectable after 2 years of treatment. In the chronic cases, the 43K antigen was detected in patients without treatment, and it was absent in the healed cases. The detection of the 43K protein specific to Paracoccidioides brasiliensis may be important for its diagnostic value as well as for modulation of the host immune response.
Evidence for the occurrence of the same strain of Campylobacter pylori in the stomach and dental plaque
Authors: Shames B , Krajden S , Fuksa M , Babida C , Penner J L
Published: January 2020

Restriction endonuclease analysis with HindIII, HaeIII, and BglII endonucleases of DNA extracted from each of eight colonies of Campylobacter pylori subcultured from a stomach biopsy and from each of eight colonies subcultured from dental plaque of the same patient indicated that at least three strains were present in the dental plaque but only one strain was present in the biopsy. One of the dental strains had restriction patterns indistinguishable from those of the biopsy isolate, providing evidence that both sites were infected with the same strain of C. pylori.
Maltose-negative Neisseria meningitidis isolated from a case of male urethritis
Authors: Phillips E A , Shultz T R , Tapsall J W , Chambers I W
Published: January 2020

A maltose-negative strain of Neisseria meningitidis isolated from a male patient with urethritis was initially identified as a gonococcus on the basis of carbohydrate utilization tests. Additional investigations initiated because of atypical colony morphology and a negative superoxol reaction showed the isolate to be a meningococcus with defective maltose-phosphorylating capacity.
Novel latex agglutination method with chicken anti-protein A for detection of Staphylococcus aureus infections
Authors: Larsson A , Sjöquist J
Published: January 2020

A latex agglutination assay for the detection of protein A-secreting Staphylococcus aureus strains or strains with protein A in the cell wall is described. The assay utilizes latex particles coated with chicken anti-protein A antibodies. Chicken antibodies do not react with protein G-producing streptococci or rheumatoid factor, thus avoiding false-positive reactions.
Comparison of monoclonal antibodies for rapid detection of cytomegalovirus in spin-amplified plate cultures
Authors: Ashley R , Peterson E , Abbo H , Gold D , Corey L
Published: January 2020

Cytomegalovirus (CMV) was detected in 56 of 275 specimens (20%); 50 of 56 (89%) were detected by conventional culture, and 37 (66%) were detected by rapid assay at 72 h with a commercial monoclonal antibody and a pooled monoclonal antibody. Although the two antibodies were equally sensitive at 72 h, the pooled antibody gave a brighter, more easily detected signal. Other viruses were isolated from 9 specimens (3.3%) by conventional culture. Use of rapid assays alone fails to detect slow-growing CMV and non-CMV viral pathogens.
Corynebacterium xerosis as a cause of vertebral osteomyelitis
Authors: Krish G , Beaver W , Sarubbi F , Verghese A
Published: January 2020

We report a patient who developed Corynebacterium xerosis vertebral osteomyelitis 6 months following a decompressive laminectomy. Prolonged parenteral and subsequent oral therapy for 11 months resulted in apparent cure. This is the first reported case of vertebral osteomyelitis caused by C. xerosis.
Continuous high-speed rolling versus centrifugation for detection of herpes simplex virus
Authors: Hughes J H , Hamparian V V , Mavromoustakis C T
Published: January 2020

Specimens submitted for diagnosis of herpes simplex virus infections were inoculated into shell vials and conventional culture tubes. Inoculated culture tubes were incubated with rolling at 96 rpm. Immunoperoxidase (IP) staining and cytopathic effects (CPE) were used to detect positive cultures. At 24 h, 42 (53%) of the rolled cultures were positive for CPE, while only 16 (21%) of the shell vials were CPE positive (P less than 0.01). No difference in sensitivity was seen between rolled and shell vial cultures that were inoculated with high-titered viral preparations and IP stained at 16 h. However, when low-titered preparations were used, 39 of 41 (95%) were IP positive by the high-speed roller method at 64 h postinoculation, while only 24 of 41 (58%) were IP positive with shell vials (P less than 0.01). These results indicate that high-speed roller method at 64 h postinoculation, while only 24 of 41 (58%) were IP positive with shell vials (P less than 0.01). These results indicate that high-speed rolling is better than the shell vial technique for the detection of herpes simplex virus by IP staining.
Characterization of monoclonal antibodies to human group B rotavirus and their use in an antigen detection enzyme-linked immunosorbent assay
Authors: Burns J W , Welch S K , Nakata S , Estes M K
Published: January 2020

Three monoclonal antibodies (MAbs)--B5C9, B5E4, and B10G10--to human group B rotavirus, an agent implicated in epidemic outbreaks of diarrhea in the People's Republic of China, primarily in adults, were prepared. MAb reactivity was decreased when virus preparations were treated with EDTA, suggesting reactivity with the outer-capsid protein(s). Competition experiments suggested that these MAbs recognize overlapping epitopes within a single antigenic site. A simple antigen detection enzyme-linked immunosorbent assay (ELISA) specific for the human group B rotavirus was established by using these MAbs as capture antibodies. Fifteen clinical samples obtained from three epidemic areas in the People's Republic of China and previously shown by Chinese scientists to contain group B virus were all positive in the MAb capture antigen detection ELISA, whereas none of the 57 samples lacking the group B virus reacted in the test. The results suggest that this MAb capture antigen detection ELISA will be useful to identify outbreaks caused by the human group B rotavirus and to monitor possible spread of the virus.
Prevalence of Escherichia coli strains with localized, diffuse, and aggregative adherence to HeLa cells in infants with diarrhea and matched controls
Authors: Gomes T A , Blake P A , Trabulsi L R
Published: January 2020

To determine the possible role of Escherichia coli strains with three different patterns of adherence to HeLa cells in causing diarrhea in infants in São Paulo, Brazil, we studied stool specimens from 100 infants up to 1 year of age with acute diarrheal illnesses and 100 age-matched control infants without recent diarrhea. E. coli with localized adherence to HeLa cells was much more common in patients (23%) than in controls (2%) (P less than 0.0001) and was detected more frequently than rotavirus (19%) was in patients, even though the study was conducted during the coldest months of the year. Most (80%) of the E. coli colonies with localized adherence were of traditional enteropathogenic E. coli serotypes. Little difference was found between patients and controls in the rate of isolation of E. coli with diffuse adherence (31 and 32%, respectively) or aggregative adherence (10 and 8%, respectively). A genetic probe used to detect a plasmid-mediated adhesin which confers expression of localized adherence proved to be 100% sensitive and 99.9% specific in detecting E. coli with localized adherence to HeLa cells. Although E. coli strains with localized adherence have now been shown to be enteric pathogens in several parts of the world, the role of strains showing diffuse adherence and aggregative adherence is still uncertain.
Serum antibodies to Escherichia coli serotype O157:H7 in patients with hemolytic uremic syndrome
Authors: Chart H , Scotland S M , Rowe B
Published: January 2020

Sera from 13 patients with hemolytic uremic syndrome (HUS) and 8 healthy control subjects were examined for antibodies specific for bacterial antigens of Eschericia coli serotype O157:H7. Bacterial components, including outer membrane proteins (OMPs), lipopolysaccharide (LPS), and flagella, were reacted with sera by sodium dodecyl sulfate-polyacrylamide gel electrophoresis followed by immunoblotting and by enzyme-linked immunosorbent assay. All 13 serum samples from HUS patients contained high-titered antibodies of the immunoglobulin M class against O157 LPS and some OMPs. These same sera reacted weakly with some of the major OMPs, but not the LPS, of non-O157 strains of E. coli. Sera from patients did not contain antibodies to non-O157 LPS or H7 flagella. The possibility of using E. coli serotype O157 LPS in an enzyme-linked immunosorbent assay for the routine diagnostic testing of sera from HUS patients for evidence of O157:H7 infection is discussed.
Indirect immunofluorescence test and enzyme-linked immunosorbent assay for detection of Campylobacter pylori
Authors: Schaber E , Umlauft F , Stöffler G , Aigner F , Paulweber B , Sandhofer F
Published: January 2020

An indirect immunofluorescence test (IIF) has been developed for detecting Campylobacter pylori in gastroduodenal biopsies. This test was compared with standard methods of C. pylori diagnosis, namely Gram staining and urease test, in a study population of 226 patients; 121 of the biopsy specimens were cultured for C. pylori as well. C. pylori colonization was detected in 154 of 226 patients (68%) by at least one of these methods (IIF, 96%; Gram staining, 78%; urease test, 60%; cultivation, 55%). Serum samples from 191 patients of the study population were screened for circulating antibodies to C. pylori by an indirect enzyme-linked immunosorbent assay with whole, untreated bacteria as antigen. Of these serum specimens, 140 (73%) revealed absorbance readings above the limit of positivity, which was determined as an optical density of greater than 0.35 at 405/620 nm. Of 132 serum specimens, 128 (97%) from patients with C. pylori detected in biopsies, but only 12 (20%) of 59 specimens from those without C. pylori detection showed elevated specific antibody levels. Our data revealed that IIF proved to be the superior rapid, sensitive, and specific diagnostic method. The correlation between microbiological findings and the immune response favors our enzyme-linked immunosorbent assay as an additional tool in C. pylori diagnosis.
Methicillin-resistant strains of Staphylococcus aureus resistant to quinolones
Authors: Schaefler S
Published: January 2020

Since January 1988, Staphylococcus aureus strains with a high level of quinolone resistance have been isolated at 17 hospitals and 15 nursing homes in New York City. The majority of these strains were methicillin resistant. The bacteriophage types and susceptibility to other antibiotics were similar to those of quinolone-susceptible strains isolated at the same hospitals.
Corynebacterium aquaticum urinary tract infection in a neonate, and concepts regarding the role of the organism as a neonatal pathogen
Authors: Tendler C , Bottone E J
Published: January 2020

Corynebacterium aquaticum urinary tract infection developed in a neonate 8 days after uncomplicated vaginal delivery. Prior to definitive identification, the isolate was thought to be Listeria monocytogenes because of its microscopic morphology, catalase positivity, and tumbling motility. The infant responded to intravenous ceftriaxone. Because the presentation of C. aquaticum in this patient suggested systemic involvement, C. aquaticum may be regarded as a bona fide neonatal pathogen.
Growth of Aeromonas spp. on Butzler Campylobacter selective agar and evaluation of the agar for the primary isolation of Aeromonas spp. from clinical specimens
Authors: Misra S K , Bhadra R K , Pal S C , Nair G B
Published: January 2020

The fortuitous finding that Aeromonas spp. grew well on Butzler Campylobacter selective medium (BCSA) in a microaerobic atmosphere at 42 degrees C prompted us to evaluate the performance of BCSA for selective isolation of aeromonads in comparison with ampicillin (30 micrograms/ml) sheep blood agar (ASBA30). Overall recovery rates of aeromonads from 563 stool samples from patients with acute diarrhea were higher on ASBA30 (70.4%) than on BCSA (56.3%); however, 21 (29.5%) grew only on BCSA. The three human-associated Aeromonas spp. could be recovered on BCSA and ASBA30. We recommend the use of BCSA to laboratories reluctant to include a specific selective medium for aeromonads.
Comparison of a single-antigen microimmunofluorescence assay and inclusion fluorescent-antibody assay for detecting chlamydial antibodies and correlation of the results with neutralizing ability
Authors: Peterson E M , Oda R , Tse P , Gastaldi C , Stone S C , de la Maza L M
Published: January 2020

An inclusion fluorescent-antibody assay (IFA) with McCoy cells infected with Chlamydia trachomatis serovar L2 was compared with a single-antigen (L2) microimmunofluorescence (MIF) assay for the detection of antichalmydial antibodies. A total of 562 serum specimens were tested by both assays, and sera representing a range of titers were tested for their ability to neutralize the infectivity of C. trachomatis. Overall, there was poor correlation between the two assays (r2 = 0.62). With most sera the inclusion IFA was more sensitive. There was better correlation between IFA titer and ability to neutralize the five serovars tested (L2, L3, C, E, and F) than between the MIF assay and neutralization. In summary, the IFA appeared to be more sensitive than the MIF assay for detecting antibodies to C. trachomatis.
Characterization of anaerobic bacteria by using a commercially available rapid tube test for glutamic acid decarboxylase
Authors: Banks E R , Allen S D , Siders J A , O'Bryan N A
Published: January 2020

A rapid glutamic acid decarboxylase microdilution test for presumptive identification of certain anaerobic bacteria was marketed recently by Carr-Scarborough Microbiologicals, Inc., Stone Mountain, Ga. The test was evaluated with 474 clinical isolates, representing 11 genera and 54 species, and was found to be a useful aid in the presumptive identification of Bacteroides fragilis, B. distasonis, B. vulgatus, B. thetaiotaomicron, B. ovatus, B. uniformis, B. eggerthii, Clostridium perfringens, C. barati, C. sordellii, and Eubacterium limosum.
Production of antibody to and cellular localization of erythrocyte-sensitizing substance from Rickettsia rickettsii
Authors: Hechemy K E , Fox J , Samsonoff W A , Anacker R , Silverman D , Eisemann C , Green I S
Published: January 2020

Antibodies to Rickettsia rickettsii erythrocyte-sensitizing substance (ESS) were raised in rabbits by using a derivatized ESS. The resulting antibodies reacted with R. rickettsii and cross-reacted with Rickettsia conorii, a member of the spotted fever group rickettsiae, but did not react with Rickettsia typhi, a member of the typhus group rickettsiae, Legionella bozemanii, or Proteus vulgaris OX19 or OX2. Immunoblot analysis indicated that ESS was present in more than one fraction and that the major haptenic fraction was proteinase resistant. Immunoelectron microscopy indicated that the antibodies to R. rickettsii were specific to components located on the cell surface and intracellularly to components between the cell wall and cytoplasmic membrane.
Protein and enzyme electrophoresis profiles of selected Candida species
Authors: Lehmann P F , Hsiao C B , Salkin I F
Published: January 2020

The cellular protein profiles and malate dehydrogenases, superoxide dismutases, alkaline phosphatases, and esterases from whole cell extracts of Candida spp. were studied with polyacrylamide gel electrophoresis. We investigated isolates that differed in their ability to assimilate sucrose as the sole carbon source. The protein and enzyme patterns of Candida tropicalis and its sucrose-negative variant "Candida paratropicalis Baker, Salkin, Pincus et D'Amato" were indistinguishable. Although the cellular protein and superoxide dismutase patterns of Candida albicans and its sucrose-negative variant "Candida stellatoidea" were quite similar, differences were noted in the profiles of the other enzymes studied. In addition, the C. stellatoidea isolates were found to be separable, on the basis of their enzyme profiles, into the same two types that have been reported by Kwon-Chung et al. (K.J. Kwon-Chung, B.L. Wickes, and W.G. Merz, Infect. Immun. 56:1814-1819, 1988).
Use of an enzyme-linked immunosorbent assay for detection of Treponema hyodysenteriae infection in swine
Authors: Wright J C , Wilt G R , Reed R B , Powe T A
Published: January 2020

Discriminate analysis was used to evaluate the enzyme-linked immunosorbent assay (ELISA) for the detection of anti-Treponema hyodysenteriae antibodies in experimentally and naturally infected swine. In trial 1, 26 pigs were randomly divided into three groups (naturally infected, n = 8; experimentally infected, n = 11; and noninfected, n = 7), and samples were collected for 10 weeks. For trial 2, 31 pigs were randomly divided into two groups (naturally infected, n = 22; and noninfected, n = 7), and samples were collected for 20 weeks. Rectal swabs for T. hyodysenteriae isolation were collected daily, and fecal samples for isolation of Salmonella spp. were collected weekly. Serum samples for ELISA evaluation were collected biweekly (trial 1) or weekly (trial 2). Results of discriminate analysis indicated that the ELISA correctly identified 90% or more of the individually infected pigs at prior probabilities of infection ranging from 60 to 90%. The test correctly identified noninfected pigs at a lower rate (61 to 92% range). The mean ELISA titers of naturally infected pigs without clinical signs were not significantly different (P less than 0.05) from the titers of both groups of experimentally infected pigs. Mean ELISA titers of naturally infected pigs without clinical signs were significantly greater than the mean titers of naturally infected pigs with clinical signs. Naturally infected pigs with clinical signs had a mean ELISA titer that was significantly greater than that of noninfected pigs and significantly less than the mean titers of the experimentally infected pigs without clinical signs and the naturally infected pigs without clinical signs.
Characterization of instrumentation and calibrators for quantitative microfluorometry for immunofluorescence tests
Authors: Kaplan D S , Picciolo G L
Published: January 2020

The current method for measuring reagents for immunofluorescence microscopy involves a subjective evaluation of the endpoint (titer) with a negative or positive (1+ to 4+) scale. Variability is due to the biological constituents of the reagent, the observer, and the instrumentation. To have reliable methods for evaluation of performance of these products, we are developing a quantitative method that uses photometric measurements of microscopically observed epifluorescence of slide preparations. A computer-controlled microscope-photometer converts the light intensity into a voltage measurement. Our goal is to replace the subjective endpoint determination with an objective, quantitative method. The instrumentation and its operating characteristics are presented in this paper. Selected commercially available fluorescent materials were evaluated as calibrators for the instrumentation. These materials showed consistency in measurement and thus demonstrated their suitability for various levels of calibration. It is possible that they will prove useful as a reference standard for interlaboratory comparisons.
Microbial burdens in disposable and nondisposable ventilator circuits used for 24 and 48 h in intensive care units
Authors: Malecka-Griggs B , Kennedy C , Ross B
Published: January 2020

One hospital sought to study the differences in using resterilizable permanent versus disposable ventilator circuits and changing the circuits on a 24-h versus a 48-h basis. Over a period of 13 months 656 condensate samples from 92 permanent and 72 disposable circuits were collected and plated by a loop dilution technique. Two samples were collected from the inspiratory limb (humidifier; tubing or nebulizer), and two were collected from the expiratory limb (tubing and trap) of each circuit. Contamination rates were higher for disposable circuits than for permanent circuits and for 48-h changes than for 24-h changes. Results of chi 2 testing by site indicated there was more contamination on the inspiratory and expiratory limbs each with use of disposable circuits than with the use of permanent circuits. The total results (chi 2 analysis) showed significantly greater microbial growth with the use of disposable circuits (permanent versus disposable, P less than 0.001) and extension of time to 48-h changes (24 h versus 48 h, P less than 0.05). In the experience of this hospital permanent circuits proved more advantageous from the standpoint of contamination risk and cost.
Comparative virulence of human isolates of coagulase-negative staphylococci tested in an infant mouse weight retardation model
Authors: Gunn B A
Published: January 2020

Human infections caused by coagulase-negative staphylococci have steadily increased in numbers and severity. Causes may be the use of artificial prostheses, immunocompromising chemotherapy and radiation therapy, and sophisticated surgical techniques, to name a few. Although the infectivity of coagulase-negative staphylococci as a group has been well documented for humans, attempts to study the pathogenesis of infections caused by individual species of coagulase-negative staphylococci have been hampered by the lack of an animal model that is not refractory to infection by these organisms. In the study reported here, a 2-day-old-mouse weight retardation test was used to assay the virulence of 60 clinical and reference strains of coagulase-negative staphylococci. These strains represented eight species of coagulase-negative staphylococci. The most virulent strains were demonstrated to be of the species Staphylococcus haemolyticus, S. saprophyticus, and S. epidermidis. The data further suggest that production of slime is a marker of virulence in S. epidermidis and that intraspecies differences in virulence occur.
Effect of milk on fibronectin and collagen type I binding to Staphylococcus aureus and coagulase-negative staphylococci isolated from bovine mastitis
Authors: Miedzobrodzki J , Naidu A S , Watts J L , Ciborowski P , Palm K , Wadström T
Published: January 2020

Tryptic soy broth (TSB)-grown cells of Staphylococcus aureus isolated from acute and chronic bovine mastitis bound mainly 125I-fibronectin (Fn) [corrected], whereas strains of nine species of coagulase-negative staphylococci showed a predominant interaction with 125I-collagen (Cn) [corrected] type I. A particle agglutination assay (PAA) was used to examine the interaction of coagulase-negative staphylococci with 125I-Fn and 125I-Cn immobilized on latex. All 368 coagulase-negative staphylococci demonstrated high 125I-Cn and moderate to low 125I-Fn interactions in the PAA. Cn-PAA reactivity was high among strains of Staphylococcus xylosus (84.2%), Staphylococcus simulans (77.8%), Staphylococcus epidermidis (76.7%), and Staphylococcus hyicus (74.3%), whereas all six Staphylococcus capitis strains clumped Cn-PAA reagent. Incubating TSB-grown cells in 10% skim milk for 1 h decreased the 125I-Fn- and 125I-Cn-binding affinity in most of the S. aureus and coagulase-negative staphylococci, while growth in 10% skim milk for 18 h resulted in more than 90% decrease or complete loss of interaction with these proteins. Decreased 125I-Fn binding in the presence of milk was correlated with protease production but not with 125I-Cn binding.
Epidemiological typing of Enterobacter aerogenes
Authors: Gaston M A , Strickland M A , Ayling-Smith B A , Pitt T L
Published: January 2020

The applicability of Enterobacter cloacae and Klebsiella typing reagents for classifying clinical strains of Enterobacter aerogenes was evaluated. Of 75 strains, none were agglutinated by E. cloacae O antisera or were sensitive to E. cloacae bacteriophages. In contrast, 70 strains reacted with Klebsiella capsular antisera. Two-thirds of the strains were lysed by Klebsiella typing phages. A set of five E. aerogenes bacteriocin producers classified 92% of strains into 15 sensitivity types. In conclusion, E. aerogenes may be typed with Klebsiella reagents, and the simple bacteriocin test provides further discrimination between strains. The limited number of capsular antigens in the species and their apparent similarity to Klebsiella capsular antigens warrant further investigation.