bluuebunny/crossref_metadata_2025 huggingface dataset:
Persistent in vitro survival of coagulase-negative staphylococci adherent to intravascular catheters in the absence of conventional nutrients
Authors: Franson T R , Sheth N K , Menon L , Sohnle P G
Published: January 2020

The in vitro survival of coagulase-negative staphylococci in media devoid of routine nutritional supplementation was assessed in the presence and absence of catheter materials to evaluate bacterium-device interactions. Strains of slime- and non-slime-producing coagulase-negative staphylococci were suspended in phosphate-buffered saline together with multiple segments of polyvinyl chloride (PVC), Teflon, Silastic, and polyurethane catheters and in control suspensions without catheters. Catheters were removed at 2 min and 24, 48, 72, and 96 h of incubation and washed thoroughly, and semiquantitative roll cultures were performed on blood agar. In addition, after 96 h catheters were introduced into tryptic soy broth (TSB), and roll cultures were performed after 18 h of incubation. Results demonstrated that after 96 h, 6 of 32 catheter specimens (4 PVC) had greater than 10 CFU of coagulase-negative staphylococci per catheter; after TSB addition, 18 of 32 catheter specimens had greater than or equal to 100 CFU per catheter (8 of 8 PVC catheters had greater than 1,000 CFU per catheter). In control suspensions, no growth was seen at 96 h or after TSB addition. No differences in the survival of slime- versus non-slime-producing strains were observed in control or catheter studies. These findings suggest that both slime- and non-slime-producing coagulase-negative staphylococci survive in vitro on catheters (especially PVC) in the absence of conventional nutrients and can proliferate on catheters when nutrients are added. Catheter-adherent coagulase-negative staphylococci appear to possess survival mechanisms under adverse conditions which may relate to the genesis of occult foreign-body-associated infections.
Monoclonal antibodies against Escherichia coli heat-stable toxin (STa) and their use in a diagnostic ST ganglioside GM1-enzyme-linked immunosorbent assay
Authors: Svennerholm A M , Wikström M , Lindblad M , Holmgren J
Published: January 2020

Seven monoclonal antibodies (MAbs) against heat-stable enterotoxin (ST) from a human Escherichia coli isolate were prepared and evaluated for their usefulness in an ST immunodetection assay, the ST ganglioside GM1-enzyme-linked immunosorbent assay (ELISA). This assay is based on the ability of STa, as present in, for example, culture filtrates from ST-producing E. coli, to inhibit specific anti-ST antibody from binding to solid-phase-bound ST ganglioside (GM1-bound ST-cholera B subunit). Four of the MAbs were of immunoglobulin G1 (IgG1), one was of IgG2b, and two were of IgM isotype. All the IgG1 MAbs could be completely inhibited by addition of free ST; 0.2 to 0.4 ng of purified ST inhibited binding of these MAbs by 50%. The non-IgG1 MAbs were, in contrast, not inhibited by 200-fold-higher amounts of purified ST, probably because they were directed against linkage epitopes or were of low affinity or both. When the IgG1 MAbs were tested in the ST GM1-ELISA, ST could be detected in culture filtrates from stock human E. coli isolates with 100% sensitivity and specificity. ST in filtrates from fresh stool cultures was demonstrated with higher sensitivity with the MAbs ST GM1-ELISA than with the conventional infant mouse test. Both subtypes of STa, STaI and STaII, could be detected by the ST GM1-ELISA by using either IgG1 MAb in the immunodetection step, whereas infant-mouse-active ST from Yersinia enterocolitica failed to react.
Passive hemagglutination test for antibody to hepatitis B core antigen
Authors: Petchclai B , Khupulsup K , Wasi C , Bhamarapravati N
Published: January 2020

Available tests for antibody to hepatitis B core antigen (anti-HBc) are complicated. A passive hemagglutination assay for anti-HBc was developed by sensitizing sheep erythrocytes with hepatitis B core antigen synthesized by a recombinant DNA technique. It was compared with a commercial passive hemagglutination assay and an enzyme-linked immunosorbent assay for anti-HBc and showed good agreement with both. It is rapid, simple, and sensitive.
Effect of medium and cultivation conditions on comparisons between latex agglutination and culture detection of group A streptococci
Authors: Graham L , Meier F A , Centor R M , Garner B K , Dalton H P
Published: January 2020

In the laboratory diagnosis of pharyngitis, results from latex agglutination tests (LAT) performed directly on throat swabs are often compared with the isolation of group A beta-hemolytic streptococci (GABHS) from simultaneously obtained swabs cultivated on a variety of media under different atmospheric conditions. In this study, results of an LAT, Directigen, were compared with those of two different media: sheep blood agar (SBA) and group A selective strep agar (ssA). Specimens inoculated on SBA were incubated in three different atmospheres: air, 3 to 5% CO2, and anaerobically. Those inoculated on ssA were incubated in 3 to 5% CO2 only. Isolation of GABHS was confirmed by coagglutination. The standard for true positivity was the isolation of GABHS from at least one of the simultaneous cultures. Comparisons were made with samples from 693 adult patients. GABHS was isolated on at least one of the three cultures in 143 patients, demonstrating an isolation rate of 20.6%. LAT exhibited a sensitivity of 95.1%. SBA incubated in air, in CO2, or anaerobically had sensitivities of 86.2, 85.9, and 93.7%, respectively. The ssA detected 99.3% of the positive specimens. Single SBA culture proved to be inferior to LAT and therefore was a poor standard for measuring LAT performance. Single ssA cultures demonstrated the greatest sensitivity in GABHS detection and therefore could serve as a standard for measuring LAT performance.
Improved biochemical screening procedure for small clinical laboratories for vero (Shiga-like)-toxin-producing strains of Escherichia coli O157:H7
Authors: Haldane D J , Damm M A , Anderson J D
Published: January 2020

Of 327 sorbitol-negative fecal isolates of Escherichia coli, 37 O157:H7 Vero (Shiga-like)-toxin-producing strains were identified. The specificity of the basic sorbitol screen was improved from 11.3 to 33.6% by the exclusion of organisms with negative ornithine and lysine decarboxylase reactions.
Elimination of toxicity and enhanced cytomegalovirus detection in cell cultures inoculated with semen from patients with acquired immunodeficiency syndrome
Authors: Howell C L , Miller M J , Bruckner D A
Published: January 2020

Although semen is a particularly rich source of cytomegalovirus (CMV) and is useful for monitoring CMV shedding, its culturing is associated with extensive monolayer toxicity, isolation failures, and lengthy detection times. Inoculation of fractionated semen with immunoperoxidase staining of monolayers eliminated virtually all toxicity, increased isolation rates and monolayer infectivity, and greatly reduced detection times. Semen specimens (n = 73) were processed conventionally (C) or separated into supernatant (SF) and cellular pellet (PF) fractions, and 35% of C and SF inocula produced extensive toxicity. In contrast, virtually no toxicity was observed in monolayers inoculated with PF. C and SF isolation rates were 41 of 73 and 38 of 73, respectively, whereas that for PF was 51 of 73. Although monolayer infectivity at initial CMV detection was often less than 10% for C and SF, it was as much as 25% for PF. Average detection times were reduced from 13 days for C and SF to 6 days with PF and were further reduced to 3 days when PF inoculation was combined with immunoperoxidase staining. Thirty percent of specimens negative by C were positive by PF.
Cedecea davisae bacteremia
Authors: Perkins S R , Beckett T A , Bump C M
Published: January 2020

A case of bacteremia caused by Cedecea davisae is presented. This is the first reported case of bacteremia caused by this organism.
Comparison of immunofluorescence and hemagglutination inhibition tests and enzyme-linked immunosorbent assay for detection of serum antibody in rats infected with hemorrhagic fever with renal syndrome virus
Authors: Takahashi Y , Okuno Y , Yamanouchi T , Takada N , Yamanishi K
Published: January 2020

Serum antibodies against the B-1 strain of hemorrhagic fever with renal syndrome (HFRS) virus in wild and experimental rats were investigated by the indirect immunofluorescent antibody (IF) test, the hemagglutination inhibition (HI) test, and an enzyme-linked immunosorbent assay (ELISA). In the newly developed ELISA, monoclonal antibodies to the B-1 strain were applied as coating antibody. In sera from wild rats, the results obtained by the ELISA agreed quite well with those obtained by the HI test, but some serum samples that gave a negative reaction in the HI test gave a positive reaction in the IF test, although their IF titers were very low. In serum samples from experimental rats that had been kept in an animal house infected with HFRS virus, a group with high titers and a group with low or negative titers were clearly differentiated by all the tests.
Detection of Campylobacter pyloridis in patients with antrum gastritis and peptic ulcers by culture, complement fixation test, and immunoblot
Authors: von Wulffen H , Heesemann J , Bützow G H , Löning T , Laufs R
Published: January 2020

The association of Campylobacter pyloridis with antrum gastritis and peptic ulcers was described. We investigated antral biopsies from 180 patients who underwent gastroscopy. By culture or Gram stain or both, we found overall 98 (54%) of them to be positive for C. pyloridis. In the various groups the following percentages were found to be positive: normal antral mucosa 3% (n = 30); moderate superficial antrum gastritis, 49% (n = 83); severe superficial antrum gastritis, 86% (n = 44); duodenal ulcer, 83% (n = 54); and gastric ulcer, 72% (n = 18). A serological screening that used a complement fixation test yielded the following results: highest rates of positive complement fixation titers were seen in patients with severe gastritis and those with duodenal ulcers, both with 79%; the lowest incidence was in a group of 20 blood donors, with 5%. Positive complement fixation titers in gastritis patients also correlated well with characteristic patterns on immunoglobulin G and A immunoblots, while there was no specific reactivity observed on immunoglobulin M immunoblots.
Identification of type D Pasteurella multocida by counterimmunoelectrophoresis
Authors: Chengappa M M , Carter G R , Bailie W E
Published: January 2020

A counterimmunoelectrophoresis (CIE) test was applied to serotype 35 isolates of type D Pasteurella multocida recovered from 32 cases of atrophic rhinitis (in swine) and 3 cases of snuffles (in rabbits). The CIE test was compared with the indirect hemagglutination (IHA) and acriflavine (AF) tests. Results of the CIE test correlated 100% with those of the IHA test whereas results of the AF test correlated 91.43% with those of the IHA test. The CIE test was rapid and simpler to perform compared with the IHA test and more sensitive than the AF test. Cross-reactions were not encountered with capsular antigens of P. multocida types A, B, and E in the CIE test. The CIE test was not found to be suitable for typing type A P. multocida strains.
Rapid detection of cytomegalovirus in clinical specimens by using biotinylated DNA probes and analysis of cross-reactivity with herpes simplex virus
Authors: Lurain N S , Thompson K D , Farrand S K
Published: January 2020

A method for rapid identification of human cytomegalovirus (HCMV) was developed with biotinylated DNA probes. BamHI restriction fragments from HCMV strain AD169 were selected and tested for their ability to detect virus in patient urine samples. All probes detected 30 pg of HCMV AD169 DNA. The BamHI B fragment detected 15 of 29 cell-culture-positive samples (sensitivity, 52%). There were four samples which were probe positive and cell culture negative (specificity, 87%). The D and H fragments used as combined probes detected 17 of 21 cell-culture-positive samples (sensitivity, 81%). There were five probe-positive and cell-culture-negative samples (specificity, 68.8%). The H fragment, when used alone, detected 11 of 14 culture-positive samples, and 5 samples were culture negative and probe positive. Sensitivity (78.6%) and specificity (76.2%) for the H fragment were similar to those for the combined probes, but the color intensity of the positive reactions detected by the H fragment alone was lower. There was unexpected cross-reactivity with herpes simplex type 1 and 2 controls when the combined D and H probes were used. Specific hybridization was demonstrated between subfragments of the HCMV BamHI D fragment and the herpes simplex virus type 1 EcoRI M fragment.
Accuracy of immunoglobulin M immunoassay for diagnosis of chlamydial infections in infants and adults
Authors: Mahony J B , Chernesky M A , Bromberg K , Schachter J
Published: January 2020

An improved solid-phase enzyme immunoassay (EIA) with Chlamydia trachomatis L2 434/Bu elementary bodies was developed for the measurement of immunoglobulin M (IgM) antibody to C. trachomatis in serum. Comparison of EIA and microimmunofluorescence IgM antibody titers of 156 serum samples revealed an EIA sensitivity and specificity of 100% for infants, but reduced sensitivity (85%) and specificity (76%) for sera from adults. Sera containing IgM class rheumatoid factor produced false-positive IgM results which could easily be eliminated by pretreatment of the sera with anti-human IgG. Analysis of sera from infants with chlamydial infections revealed that 17 of 17 infants with C. trachomatis pneumonia had high IgM antibody titers (geometric mean titer, 1:64,812), whereas two infants with conjunctivitis only lacked detectable IgM antibody. EIA detected IgM antibody to several serovar groups in serum, including serovars B, BDE, FG, and J. IgM antibody to C. trachomatis in serum was detected as early as 5 days after the infection that was acquired at delivery and persisted for 3 months. The availability of an EIA possessing good sensitivity and specificity for the detection of IgM antibody to C. trachomatis may permit more laboratories to diagnose perinatal chlamydial infections.
GM1 erythroimmunoassay for detection and titration of Escherichia coli heat-labile enterotoxin
Authors: Germani Y , Bégaud E , Guesdon J L , Moreau J P
Published: January 2020

A GM1 ganglioside erythroimmunoassay for the detection of heat-labile Escherichia coli enterotoxin (LT) was developed for use in poorly equipped laboratories in developing countries. This assay is based on the immunological similarity between Vibrio cholerae toxin and LT and uses cholera toxin antiserum and sheep anti-rabbit immunoglobulin covalently coupled to sheep erythrocytes as conjugate. This assay has the following advantages over other currently available techniques: the reagents it uses are stable, in particular, tanned and sensitized sheep erythrocytes; GM1 ganglioside is commercially available; erythro-adsorption can be read with the naked eye; the test can be completed in 1 day; and as little as 4 ng of V. cholerae toxin or LT per ml can be detected accurately. The GM1 ganglioside erythroimmunoassay showed good quantitative and qualitative correlation with the Vero cell assay and the conventional GM1 enzyme-linked immunosorbent assay. The GM1 ganglioside erythroimmunoassay was somewhat less sensitive than the GM1 enzyme-linked immunosorbent assay but more sensitive than the Vero cell assay. Results obtained for 12 LT-positive and 138 LT-negative E. coli strains correlated with results obtained with GM1 enzyme-linked immunosorbent and Vero cell assays.
Screening pneumococci for penicillin resistance
Authors: Swenson J M , Hill B C , Thornsberry C
Published: January 2020

Eighty-four pneumococci with various MICs of penicillin (38 with MICs of less than or equal to 0.06 micrograms/ml [susceptible], 35 with MICs of 0.12 to 1.0 micrograms/ml [relatively resistant], and 11 with MICs of greater than 1.0 micrograms/ml [resistant] ) were screened by a disk diffusion test using oxacillin and methicillin to see how well they distinguished penicillin-susceptible strains from those with decreased susceptibility to penicillin. The effects of Mueller-Hinton agar plus 5% sheep blood and Trypticase soy agar plus 5% sheep blood and two atmospheres, ambient air and a candle extinction jar (increased CO2), were compared. There were no obvious differences between the effects of the two media, but zones were generally larger in ambient air than in increased CO2. Although the oxacillin test can separate penicillin-susceptible and -resistant strains, it cannot separate penicillin-resistant from relatively penicillin-resistant strains by using the breakpoint of less than 20 mm recommended by the National Committee for Clinical Laboratory Standards. When the 20-mm breakpoint was applied to methicillin, 12% of the relatively resistant strains tested were erroneously classified as susceptible. When different breakpoints were used for methicillin, there was better separation of the two classes of penicillin-resistant isolates, but a few relatively resistant strains were still classified as susceptible. We recommend that oxacillin, not methicillin, be used as the screening agent with Mueller-Hinton sheep blood agar and ambient air incubation and that the breakpoint be less than 20 mm to indicate resistance or relative resistance.
Detection of Corynebacterium kutscheri in animal tissues by DNA-DNA hybridization
Authors: Saltzgaber-Muller J , Stone B A
Published: January 2020

Corynebacterium kutscheri, a pathogen of experimental rats and mice, is difficult to detect in the early stages of infection. A diagnostic assay was developed to reveal the organism in tissues of asymptomatic, infected animals. Three fragments of DNA specific to C. kutscheri were isolated, radiolabeled with 32P, and used in DNA-DNA hybridization assays with blots of impression smears of animal tissues on membrane filters. The C. kutscheri probes did not cross-hybridize with 15 DNA isolates from nonpathogenic corynebacteria. The method described is more rapid and more specific than conventional immunological and culture procedures used to detect C. kutscheri; the organism was detected in tissues of animals infected for only 1 week.
Virulence characteristics of Aeromonas spp. in relation to source and biotype
Authors: Kirov S M , Rees B , Wellock R C , Goldsmid J M , Van Galen A D
Published: January 2020

The significance of Aeromonas spp. as potential water-borne enteric pathogens in Tasmania, Australia, an area with a mild climate and comparatively low year-round water temperatures, was investigated in view of the reported marked peak of Aeromonas-associated gastroenteritis in the summer and the apparent influence of temperature on levels of potentially pathogenic species in water supplies. Biochemical characteristics and virulence-associated properties--exotoxin production (hemolysin, enterotoxin), ability to grow at 43 degrees C, and possession of pili--were determined for 105 Tasmanian isolates of Aeromonas spp.; 43 isolates were from clinical specimens (greater than 75% diarrhea associated) and 62 were from water. Current classification schemes were evaluated for these isolates. A. sobria comprised 35% of the clinical isolates and 16% of the water isolates, A. hydrophila comprised 56 and 79%, and A. caviae comprised 9 and 5%. A total of 42% of the clinical isolates and 15% of the environmental isolates were enterotoxigenic (by the suckling mouse assay); these levels were significantly lower than those found in warmer environments. The majority (74%) of enterotoxigenic isolates were A. sobria. Enterotoxin-producing isolates possessed three or more of the following properties. They were Voges-Proskauer positive, did not hydrolyze arabinose, were positive for lysine decarboxylase, were able to grow at 43 degrees C, and produced large amounts of hemolysin (titer, greater than 128). Thus, the biochemical scheme proposed by Burke et al. (V. Burke, J. Robinson, H.M. Atkinson, and M. Gracey, J. Clin. Microbiol. 15:48-52, 1982) for identifying enterotoxigenic isolates appears to have widespread applicability. Environmental enterotoxigenic isolates possessed numerous pili, but these appeared to be lost once infection was established, as a similar isolates from patients with diarrhea were poorly piliated.
Heating cells in acid methanol for 30 min without freeze-drying provides adequate yields of fatty acids and alcohols for gas chromatographic characterization of mycobacteria
Authors: Jimenez J , Larsson L
Published: January 2020

We studied the release of mycobacterial fatty acids (as methyl esters) and secondary alcohols after heating both wet and freeze-dried cells in methanolic hydrogen chloride for different time periods. A 30-min heating of the mycobacteria without prior freeze-drying was found adequate in a routine gas chromatographic procedure for strain and species characterization.
Precipitating antibody against lipopolysaccharide of Haemophilus actinomycetemcomitans in human serum
Authors: Okuda K , Kato T , Naito Y , Takazoe I
Published: January 2020

Approximately 6% of 50 tested human sera possessed precipitating antibody against lipopolysaccharide from Haemophilus actinomycetemcomitans (Actinobacillus actinomycetemcomitans).
Five cases of Haemophilus segnis appendicitis
Authors: Welch W D , Southern P M , Schneider N R
Published: January 2020

The clinical, histological, and bacteriological findings in five cases of acute appendicitis caused by Haemophilus segnis are reported. This is the first documentation of appendicitis associated with this organism.
Community-acquired bloodstream infection caused by Pseudomonas paucimobilis: case report and review of the literature
Authors: Morrison A J , Shulman J A
Published: January 2020

Various sources of Pseudomonas paucimobilis bacterial infections have been documented. We report the third human case of bloodstream infection due to P. paucimobilis and review the literature in English regarding community-acquired and nosocomial infection due to this bacterium. Biochemical and genetic characteristics supporting the pathogenic potential of P. paucimobilis are presented, and the antibiotic susceptibility profile of the organism is summarized.
Evaluation of a xylene substitute in Ehrlich indole test
Authors: Egleton J H , Fraser G P , Gerber B , Logan A L , Rinehardt C J , Reynolds S M , Neimeister R
Published: January 2020

Hemo-De (PMP Medical Industries, Inc., Irving, Tex.) was evaluated and found to be a suitable substitute for xylene in the Ehrlich modification of the indole test.
Direct immunofluorescence microscopy for rapid screening of Campylobacter enteritis
Authors: Hodge D S , Prescott J F , Shewen P E
Published: January 2020

Diagnostic use of a direct fluorescent-antibody test for detection of Campylobacter jejuni and C. coli in human fecal specimens (n = 497) was compared with detection by culturing (specificity, 99.7%; sensitivity, 40%). Conjugates were prepared from immunoglobulin G antibody against 22 Lior C. jejuni and C. coli reference strains (H. Lior, D. L. Woodward, J. A. Edgar, L. J. Laroche, and P. Gill, J. Clin. Microbiol. 15:761-768, 1982). Interestingly, the serotypes of cultures tested by the direct fluorescent antibody test were different from those of cultures tested by Lior slide agglutination, although the antisera used were common to both test systems.
Peritonitis caused by Alcaligenes denitrificans subsp. xylosoxydans: case report and review of the literature
Authors: Morrison A J , Boyce K
Published: January 2020

We report the third human case of peritonitis caused by Alcaligenes denitrificans subsp. xylosoxydans and review the English literature regarding community-acquired and nonsocomial infection and colonization that results from this bacterium. The biochemical and genetic characteristics supporting the pathogenic potential of A. denitrificans subsp. xylosoxydans are reviewed, and the antimicrobial susceptibility profile of the organism is summarized.
Torulopsis candida, a new opportunistic pathogen
Authors: St-Germain G , Laverdière M
Published: January 2020

We described the first documented case of intravenous-catheter-associated fungemia caused by Torulopsis candida (Candida famata). The microorganism was isolated from two blood cultures and one intravenous catheter tip in a bone marrow transplant patient. Both the intravascular cannula and the immunological status of the patient are believed to have played major roles in predisposing the patient to such an infection. Uneventful recovery occurred after the removal of the catheter and amphotericin B therapy.
Comparison of two new tests for rapid diagnosis of respiratory syncytial virus infections by enzyme-linked immunosorbent assay and immunofluorescence techniques
Authors: Freymuth F , Quibriac M , Petitjean J , Amiel M L , Pothier P , Denis A , Duhamel J F
Published: January 2020

The sensitivity and the specificity of two new commercial reagent tests, an indirect fluorescent antibody test (FAT) with a mouse monoclonal antibody (MAb) against respiratory syncytial virus (RSV) and an enzyme-linked immunosorbent assay (ELISA) RSV antigen detection kit, were determined by a comparison of results from these tests with those of tissue culture isolation and an indirect FAT with bovine polyclonal antibody (BPA). Of 251 nasal aspirates from infants with suspected RSV infection, positive results were found for 99 (39%) by the FAT-MAb, 93 (37%) by the FAT-BPA, and 87 (35%) by the ELISA; 69 of 240 (29%) were positive by cultures. The FAT-MAb was a more sensitive technique than cultures, with 87% sensitivity for the FAT-MAb and 84% for the ELISA. It was also more sensitive than the FAT-BPA, with 97% sensitivity for the FAT-MAb and 85% for the ELISA. This could be caused only by the distinctive volume of suspended specimens used in these tests. Of 171 negative culture specimens, positive (but not false-positive) results were found for 18% by the FAT-MAb and for 12% by the ELISA. Inversely, 13% of 69 culture positive specimens were FAT-MAb negative and 16% were ELISA negative, emphasizing the importance of tissue cultures for the maximum recovery of RSV, as well as for detection of other respiratory viruses. The FAT-MAb and ELISA were easy to perform and interpret, thus facilitating wider use.
Heterologous protection against rotavirus-induced disease in gnotobiotic piglets
Authors: Bishop R F , Tzipori S R , Coulson B S , Unicomb L E , Albert M J , Barnes G L
Published: January 2020

Administration per os of 2 X 10(6) fluorescent cell-forming units of a human serotype 3 rotavirus (RV-3) protected all of nine gnotobiotic piglets against severe diarrheal disease when they were challenged 10 to 14 days later with 8 X 10(3) fluorescent cell-forming units of virulent wild-type porcine rotavirus (AT/76). The porcine virus was similar antigenically to porcine prototype strain OSU, previously described as antigenically distinct from all four recognized human serotypes. Administration of RV-3 was associated with the development of serum-neutralizing antibody to both RV-3 and AT/76 in piglets that excreted RV-3. Neutralizing antibody levels to RV-3 and AT/76 increased rapidly postchallenge. Vaccinated piglets were not immune to infection with AT/76 but showed no or minimal gastrointestinal symptoms after challenge. Control nonvaccinated piglets that were fed AT/76 developed severe dehydrating diarrhea and low levels of neutralizing antibody to AT/76 alone. The apparent heterologous clinical protection observed in this study could have been predicted from results of in vitro assays. Neutralization tests with reduction of fluorescence focus indicated a one-way cross-reaction between RV-3 and AT/76 such that hyperimmune antiserum to RV-3 neutralized porcine virus to moderate titer, but not vice versa. The results emphasize the importance of neutralizing antibody in protection against disease and the need to determine reciprocal cross-neutralization titers, rather than serotype alone, in order to predict the ability of rotavirus strains to cross protect.
Comparative tests for detection of plague antigen and antibody in experimentally infected wild rodents
Authors: Shepherd A J , Hummitzsch D E , Leman P A , Swanepoel R , Searle L A
Published: January 2020

The enzyme-linked immunosorbent assay (ELISA) was compared with other standard tests for detection of plague (Yersinia pestis) antibody and antigen in multimammate mice (Mastomys coucha and M. natalensis) which were experimentally infected and then killed at daily intervals postinoculation. For detection of antibody in sera from M. natalensis, the immunoglobulin G (IgG) ELISA was equivalent in sensitivity to passive hemagglutination and more sensitive than the IgM ELISA and complement fixation. Antibody was first detected on postinfection day 6 by all four tests, but IgM ELISA titers had declined to undetectable levels after 8 weeks. For detection of fraction 1 Y. pestis antigen in rodent organs, the ELISA was less sensitive than fluorescent antibody but more sensitive than complement fixation or immunodiffusion. Plague fraction 1 antigen was detected in 16 of 34 bacteremic sera from M. coucha and M. natalensis. The threshold sensitivity of the ELISA was approximately 10(5) Y. pestis per ml.
Molecular epidemiology of adenovirus type 21 in the Netherlands and the Federal Republic of Germany from 1960 to 1985
Authors: van der Avoort H G , Adrian T , Wigand R , Wermenbol A G , Zomerdijk T P , de Jong J C
Published: January 2020

After a period of high prevalence in the early 1960s, adenovirus serotype 21 (Ad21) was identified in The Netherlands only very sporadically for more than 20 years. From December 1984 to July 1985, Ad21 was isolated relatively often from hospitalized children living in different parts of The Netherlands. The patients in question suffered from respiratory, gastrointestinal, meningeal, or ocular disorders. An increase in the incidence of Ad21 infections was also observed in the Federal Republic of Germany during this period. The DNAs of 93 isolates of Ad21 were subjected to restriction enzyme analysis with eight endonucleases. All 50 strains isolated in The Netherlands between 1960 and 1963 proved to be DNA variant Ad21/D2/20655/Netherlands/60. This variant has already been described (T. Adrian, R. Wigand, and J. C. Hierholzer, Arch. Virol. 84:79-89, 1985) as typical for the Ad21 strains circulating since 1960. Analysis of the DNAs of the 28 Ad21 strains isolated in The Netherlands or in the Federal Republic of Germany in 1984 and 1985 showed them to belong to two new, closely related DNA variants designated Ad21/D7/1857/Netherlands/84 and Ad21/D8/5398/Netherlands/85. The BglI and KpnI restriction profiles were characteristic for these recent DNA variants.
Detection of Trichomonas vaginalis in vaginal specimens by direct immunofluorescence assay
Authors: Smith R F
Published: January 2020

Vaginal discharge specimens from 105 women were examined by wet mount, culture, and a new direct immunofluorescence assay to detect Trichomonas vaginalis. The organism was detected by culture in 31 patients, by direct immunofluorescence in 26 patients, and by wet mount in 21 patients.
Isotype-specific enzyme immunoassay for influenza antibody with monoclonal antibodies to human immunoglobulins
Authors: Harmon M W , Phillips D J , Reimer C B , Kendal A P
Published: January 2020

Mouse monoclonal antibodies specific for human immunoglobulin isotypes were investigated for use in an isotype-specific enzyme immunoassay for detection of antibody to influenza type A hemagglutinin (H1 and H3). The monoclonal antibody reagents were compared with isotype-specific, hyperimmune rabbit antisera from the National Institutes of Health. Endpoint titers for immunoglobulin G (IgG) obtained with the two reagents were within fourfold of each other 84% of the time (79 of 84) and within eightfold of each other 95% of the time (89 of 94). Regression analysis of the data gave a multiple correlation coefficient (r2) of 0.77 and a Spearman rank value of 0.83 (P less than 0.001). For IgA reagents, endpoint titers agreed within fourfold 77% of the time (88 of 114) and within eightfold 92% of the time (105 of 114). The r2 was 0.73, and Spearman rank was 0.83 (P less than 0.001). IgM antibody was detected in only 17 of 114 sera by either monoclonal or polyclonal reagents. Of these sera, 14 (82%) gave titers with the two reagents that were within fourfold of each other. A similar number of fourfold titer rises were detected with each reagent in paired sera showing hemagglutination inhibition titer rises. Monoclonal antibody reagents detected 27 IgA, 29 IgG, and 6 IgM rises, while polyclonal antisera detected 26 IgA, 31 IgG, and 7 IgM rises. These results show that monoclonal antibodies specific for human immunoglobulin isotypes are suitable as reagents for diagnostic assays. The advantages of monoclonal antibodies are their high degree of specificity and the ability to be standardized and produced in unlimited quantities. Moreover, the availability of immunoglobulin subclass- and allotype-specific monoclonal antibodies will enable a more detailed analysis of the antibody response to influenza as well as other infectious agents.
Serodiagnosis of leprosy: relationships between antibodies to Mycobacterium leprae phenolic glycolipid I and protein antigens
Authors: Levis W R , Meeker H C , Schuller-Levis G B , Gillis T P , Marino L J , Zabriskie J
Published: January 2020

Sera from leprosy patients and controls were assayed for immunoglobulin M (IgM) and IgG antibodies to the Mycobacterium leprae-specific phenolic glycolipid I antigen (PG) by enzyme-linked immunosorbent assay, for IgG antibodies to M. leprae protein antigens by Western immunoblot, and for antibodies to a 65-kilodalton (kDa) protein antigen of M. leprae by a competition antibody binding assay. Elevated levels of anti-PG IgM were seen in lepromatous and borderline lepromatous patients, and elevated levels of anti-PG IgG were seen in borderline lepromatous patients. There was a significant correlation between the bacillary index (BI) and anti-PG IgM whether all leprosy patients or only multibacillary patients were analyzed. A significant correlation was seen between anti-PG IgG and BI when all leprosy patients were used for analysis, but not when only multibacillary patients were used. IgG antibodies to protein antigens of M. leprae, as detected by Western immunoblot, were more prevalent in lepromatous and borderline lepromatous patients than in borderline tuberculoid patients, while one of eight controls showed one weak band. There were significant correlations between the number of M. leprae protein antigens detected by the sera of patients and both BI and the level of anti-PG IgM. The 65-kDa competition antibody binding assay detected active multibacillary leprosy. Patients positive for antibody to the 65-kDa antigen had a significantly higher BI and levels of anti-PG IgM and anti-PG IgG than did patients that were negative. In addition, the level of antibody to the 65-kDa antigen correlated with both the BI and anti-PG IgM. We conclude that testing for antibodies to protein antigens of M. leprae may provide a useful adjunct to testing for antibodies to PG.
Humoral immune response to Q fever: enzyme-linked immunosorbent assay antibody response to Coxiella burnetii in experimentally infected guinea pigs
Authors: Williams J C , Thomas L A , Peacock M G
Published: January 2020

The response of guinea pigs experimentally infected with Coxiella burnetii organisms, the etiologic agents of Q fever, was obtained by the measurement of fever, circulating infectious C. burnetii cells, and anti-C. burnetii antibodies. The detection of antibodies by the enzyme-linked immunosorbent assay (ELISA) and traditional methods against phase I whole cells, phase II whole cells, and phase I lipopolysaccharide (LPS-I) (a virulence marker for phase I cells) antigens in the serum samples of infected animals revealed marked differences between intrastrain phase variants. Animals infected with the phase I Nine Mile strain produced a concomitant increase in temperature, circulating infectious C. burnetii cells, and antibodies against phase II cells, phase I cells, and LPS-I. At 15 weeks, a challenge of phase I-infected animals with viable phase I cells resulted in anamnestic antibody responses to phase I cells and LPS-I but not to phase II cells. Infection of animals with the phase II Nine Mile strain produced antibodies against only phase II cells. The challenge of phase II-infected animals at 15 weeks with viable phase II cells resulted in anamnestic antibody responses to phase I and phase II cells but not to LPS-I. Suppression of anti-phase II responses by the phase I challenge was apparent with only the ELISA, because the immunofluorescence, microagglutination, and complement fixation assays were insensitive to these changes. The sensitivity and specificity of the ELISA with whole-cell and the LPS-I antigens in the detection of phase-specific antibody revealed that avirulent phase II cells induced an immune response to phase I antigenic epitopes. Although the avirulent phase II cells were rapidly cleared by the host immune responses, they were sufficiently infective to induce antibody responses to both phase variants. Thus, in the occurrence of Q fever, any conventional serological technique that uses only phase II antigens may not provide a true incidence of naturally acquired infection with both phase I and II C. burnetii organisms.
Bacteroides buccae and related taxa in necrotic root canal infections
Authors: Haapasalo M
Published: January 2020

Fifty-seven adults with apical periodontitis were examined for the presence of nonpigmented Bacteroides species in 62 infected root canals. Nonpigmented Bacteroides species were found in 35 canals. In four cases two nonpigmented Bacteroides species and in one case three nonpigmented Bacteroides species were found. Species belonging to the B. fragilis group were not isolated. The most frequently isolated species were B. buccae (15 strains), B. oris (12 strains), and B. oralis (7 strains). alpha-Fucosidase, beta-N-acetylglucosaminidase, and beta-xylosidase appeared to be useful in the identification of B. buccae and B. oris. Corroding Bacteroides species were not found; all corroding strains were identified as Wolinella recta. The occurrence of nonpigmented Bacteroides species was compared with the severity of the periapical infection. A total of 13 B. buccae strains were found in acute infections and only 2 strains were found in asymptomatic infections, whereas other nonpigmented Bacteroides species were present in acutely infected and asymptomatic teeth with nearly equal frequency. Ultrastructural study of 13 B. buccae strains showed that 8 strains had a crystalline proteinaceous surface layer (S-layer) outside the outer membrane, but all 13 strains had areas of crystalline protein throughout in the outer membrane. The results suggest that B. buccae may have a specific role in the development of an acute opportunistic infection.
Antibody response in group B meningococcal disease determined by enzyme-linked immunosorbent assay with serotype 15 outer membrane antigen
Authors: Harthug S , Rosenqvist E , Høiby E A , Gedde-Dahl T W , Frøholm L O
Published: January 2020

To elucidate pathogenic aspects and serodiagnostic possibilities for meningococcal disease, we investigated levels of specific antimeningococcal immunoglobulin G (IgG), IgA, and IgM in serum by using an enzyme-linked immunosorbent assay with outer membrane antigen prepared from a Neisseria meningitidis B:15:P1.16 strain. Serum samples were drawn on hospital admission as well as during convalescence from patients suspected of purulent meningitis or meningococcal septicemia, and single samples were drawn from population controls. A total of 637 samples were examined blindly. On admission, the average antimeningococcal immunoglobulin levels were about the same in the meningococcal disease patients as in the population controls. Septicemic patients, however, had significantly lower values. During one week the mean specific immunoglobulin levels in meningococcal-disease patients increased 6 times for IgG, 14 times for IgA, and 5 times for IgM. Children younger than 1 year showed a modest and more slowly developing antibody response. There were no statistically significant differences in average antibody responses among patients infected with meningococci of different serotypes. At 100% specificity, the increase in IgG, IgA, and IgM yielded diagnostic sensitivities for meningococcal disease of 84, 52, and 66%, respectively. One of seven serum pairs from the patient control group with unknown etiology was positive for meningococcal disease in this assay. The patients with meningococcal disease originally diagnosed only by clinical signs and symptoms showed a slightly lower rate of seroconversion than the patients in whom the diagnosis was supported by test results showing a systemic Neisseria meningitidis isolate.
Detection of enteropathogens in fatal and potentially fatal diarrhea in Cairo, Egypt
Authors: Shukry S , Zaki A M , DuPont H L , Shoukry I , el Tagi M , Hamed Z
Published: January 2020

A 1-year study of the etiology of acute diarrhea complicated by severe (10%) dehydration, active bleeding, shock and cardiovascular collapse, pneumonia, acute renal failure, or seizures in infants under 18 months of age was performed in Cairo, Egypt. Of 145 infants, 19 (13%) died or left the hospital moribund; the remaining 126 patients were classified as having potentially fatal illness. A variety of enteropathogens were identified with approximately equal frequency in the fatal and nonfatal complicated cases as well as in 135 controls with severe uncomplicated diarrhea. The agents most frequently detected in infants with severe diarrhea in this population which were felt to be etiologically important were rotavirus (33%), heat-stable enterotoxin-producing Escherichia coli (20%), heat-labile enterotoxin-producing E. coli (11%), enteropathogenic E. coli (8%), and Salmonella spp. (5%). The high rate of occurrence of Giardia lamblia (35%) probably represented the high carriage rate of the protozoan in this population. Complicated (fatal and potentially fatal) cases differed from control cases in a number of ways: the onset of diarrhea was more sudden, the course was progressive and of greater initial intensity, vomiting occurred more frequently, the patients more often had visited another physician before coming to the hospital, the patients more often had respiratory symptoms and pulmonary abnormalities on auscultation, hypoactive bowel sounds and abdominal distention were more common, as was oliguria, and the patients showed lower mean body weights.
Factors influencing measurement of human salivary lysozyme in lysoplate and turbidimetric assays
Authors: Jenzano J W , Hogan S L , Lundblad R L
Published: January 2020

The use of different assay conditions has complicated the evaluation of studies relating salivary lysozyme levels to oral or systemic disease. The purpose of this study was to compare values obtained for lysozyme activity in mixed saliva of 104 healthy subjects by using two assay techniques and four variations in sample preparation. Lysozyme activity was assayed by the turbidimetric and lysoplate methods with human colostrum lysozyme as the standard. Lysozyme activity in saliva samples made 0.5 M with respect to NaCl was compared with that in untreated samples with and without centrifugation. Mean values for lysozyme concentration in centrifuged saliva were 2.2 micrograms/ml with the turbidimetric assay and 5.9 micrograms/ml with the lysoplate assay. In samples which were salt treated before centrifugation, mean concentrations increased to 17.3 and 72.9 micrograms/ml, respectively. The results for uncentrifuged saliva were four to five times higher than the results for centrifuged saliva in each of the assay systems. Salt treatment without centrifugation produced values comparable to those obtained with centrifugation. The addition of salt to human colostrum or hen egg white lysozyme generally resulted in a 20 to 25% increase in expressed activity. These results indicate that the measurement of lysozyme in the supernatant of centrifuged saliva is of questionable value, most of the lysozyme in whole saliva is inactive and may be activated by markedly increasing the ionic strength, and values for lysozyme activity in whole saliva are much greater in the lysoplate assay than in the turbidimetric assay when the same standard is used.
Comparison of serogrouping and polyacrylamide gel electrophoresis for typing Clostridium difficile
Authors: Delmée M , Laroche Y , Avesani V , Cornelis G
Published: January 2020

A typing scheme for Clostridium difficile based on slide agglutination with rabbit antisera was previously described. It allows the differentiation of 10 serogroups designated A, B, C, D, F, G, H, I, K, and X. We studied the correlation between serogrouping and polyacrylamide gel electrophoresis (PAGE) of whole-cell proteins. A total of 202 isolates from different sources were analyzed by PAGE after ultrasonic disintegration of cells from an 18-h liquid culture and treatment with sodium dodecyl sulfate and 2-mercaptoethanol. A total of 21 different patterns were observed. The reference strains from the 10 serogroups showed different profiles. For each serogroup except A, the patterns obtained with the clinical isolates were identical to the patterns obtained with the reference strains. For the 48 strains belonging to serogroup A, 12 different profiles were observed. Five of these involved strains isolated from patients with antibiotic-associated diarrhea. Typing by sodium dodecyl sulfate-PAGE thus correlates with serogrouping. In addition, it allows discrimination within the heterogeneous serogroup A.
Enteritis associated with Campylobacter laridis
Authors: Simor A E , Wilcox L
Published: January 2020

Campylobacter laridis has occasionally been isolated from patients with diarrhea, but its clinical significance in this setting has yet to be established. We report a patient with a self-limited diarrheal illness whose stool cultures yielded C. laridis. The patient also developed a specific serum bactericidal antibody response to this strain of C. laridis, suggesting that the organism was causally related to the enteric illness.
Interlaboratory evaluation of indirect enzyme-linked immunosorbent assay, antibody capture enzyme-linked immunosorbent assay, and immunoblotting for detection of immunoglobulin M antibodies to Toxoplasma gondii
Authors: Herbrink P , van Loon A M , Rotmans J P , van Knapen F , van Dijk W C
Published: January 2020

One hundred and fifteen serum samples from healthy laboratory personnel and 50 consecutive samples from 19 patients with anamnestic clinical signs of toxoplasmosis were assayed by four laboratories for the presence of immunoglobulin M antibodies to Toxoplasma gondii by an indirect enzyme-linked immunosorbent assay (ELISA), an antibody capture assay with peroxidase-labeled toxoplasma antigen, and an immunoblotting assay. In addition, a commercially available antibody capture ELISA was used. Highly significant correlation coefficients were obtained between the four laboratories and the commercial test. The indirect ELISA and antibody capture ELISA showed equal sensitivity in detection of immunoglobulin M antibodies to toxoplasma in early-stage serum samples. However, in this study, the antibody capture assay discriminated better between serum samples obtained at early or late stages of toxoplasma infection.