bluuebunny/crossref_metadata_2025 huggingface dataset:
Evaluation of a rapid screening immunoassay for antibodies to Toxoplasma gondii
Authors: Smith S B , Repetti C F
Published: January 2020

A total of 349 human serum samples were examined for anti-Toxoplasma antibodies by the Murex Single Use Diagnostic System (SUDS) qualitative screening test, indirect hemagglutination assay (IHA), and indirect immunofluorescence assay (IFA). Concordant results with SUDS and IHA were obtained for 91.9% of serum samples; 8.9% were SUDS+ and IHA-; none were SUDS- and IHA+. Comparison of the SUDS assay with IFA showed a concordance of 95.3%, with a sensitivity of 97.5% and a specificity of 94.7%. Moreover, the positive and negative predictive values were 84.9 and 99.2%, respectively, when results of the SUDS assay and IFA were compared. The SUDS assay is a rapid, simple test requiring no instrumentation and can be performed on 50 microliters of serum, features which make this an excellent screening test for detecting anti-Toxoplasma antibodies, particularly in outpatient settings.
Comparison of three dispersion procedures for quantitative recovery of cultivable species of subgingival spirochetes
Authors: Salvador S L , Syed S A , Loesche W J
Published: January 2020

Spirochetes are usually the predominant organisms observed microscopically in subgingival plaques removed from tooth sites associated with periodontitis, but these organisms are rarely isolated by cultural means, presumably because the media do not support their growth and/or because these fragile organisms are disrupted by the various procedures used to disperse plaque samples. In the present investigation, three dispersal procedures, sonification, mechanical mixing, and homogenization, were compared for their ability to permit the isolation of Treponema denticola, Treponema vincentii, Treponema socranskii, and Treponema pectinovorum from plaque samples on media that support the growth of these species. Plaque samples in which the spirochetes averaged 50% of the microscopic count were chosen. The highest viable recoveries of spirochetes were observed when the plaques were dispersed with a Tekmar homogenizer, and the lowest occurred with sonification. The highest recoveries averaged only about 1% of the total cultivable counts, indicating either that the sought-after species were minor members of the flora or that the dispersal procedures were still too harsh. A total of 91% of the isolates were T. denticola, 5% were T. socranskii, and 4% were a heretofore-undescribed species.
Development and evaluation of an enzyme-linked immunosorbent assay for serum Vi antibodies for detection of chronic Salmonella typhi carriers
Authors: Losonsky G A , Ferreccio C , Kotloff K L , Kaintuck S , Robbins J B , Levine M M
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) measuring, in serum, immunoglobulin G (IgG), IgM, and IgA to Vi capsular polysaccharide antigen that was tyraminated (Vi-Tyr) to increase its binding efficiency to microtiter plates was compared with the standard passive hemagglutination assay (PHA) as a screening test for chronic Salmonella typhi carriers. Initially, three populations were evaluated: 22 healthy U.S. adults, 17 young Chilean adults with acute typhoid fever, and 51 Chileans who had bacteriologically confirmed S. typhi chronic carriage. IgG-specific Vi-Tyr antibodies were preferentially present in the S. typhi chronic carrier state. A total of 44 of 51 (81%) chronic carriers, 0 of 22 (0%) healthy U.S. adults, and 2 of 17 (12%) Chileans with acute typhoid fever had reciprocal IgG Vi-Tyr ELISA antibody titers in serum of greater than or equal to 200. The IgG Vi-Tyr ELISA was then compared with the PHA as a screening test for chronic carriers in 141 Chilean female food handlers. One woman was serologically incriminated as a carrier by both the IgG ELISA and PHA; her coprocultures were positive for S. typhi. One other woman, identified as a carrier by PHA, was negative by culture and IgG ELISA. The IgG Vi-Tyr ELISA is as sensitive as the PHA (86 versus 76%) and as specific (95 versus 95%) in screening for chronic carriers.
Laboratory and clinical evaluation of isolation media for Campylobacter jejuni
Authors: Gun-Munro J , Rennie R P , Thornley J H , Richardson H L , Hodge D , Lynch J
Published: January 2020

Six selective isolation media were evaluated for their ability to support the growth of Campylobacter jejuni. Colony counts of 70 isolated strains of C. jejuni and recovery studies on these strains in simulated positive feces samples demonstrated that Bolton and Hutchinson' charcoal, cefoperazone, deoxycholate agar and Karmali's charcoal-based selective medium produced the highest recovery rates with the greatest suppression of other fecal flora. C. jejuni colonies were more easily recognized on charcoal-based selective medium. A clinical evaluation performed on 2,780 human, animal, and avian feces specimens confirmed the results of the laboratory investigation. From human samples, 4 more strains of C. jejuni were isolated on charcoal-based selective medium than were isolated on Skirrow medium, and 19 more strains of C. jejuni or C. coli were isolated on charcoal-based selective medium from animal specimens. Suppression of normal fecal flora was also greater on charcoal-based selective medium.
Subtyping of Legionella pneumophila serogroup 1 isolates by monoclonal antibody and plasmid techniques
Authors: Maher W E , Para M F , Plouffe J F
Published: January 2020

A group of environmental and clinical Legionella pneumophila serogroup 1 isolates was subtyped by monoclonal antibody dot immunoblotting and plasmid analysis. Monoclonal antibody analysis defined seven subtypes within three major groups. Plasmid analysis (including restriction endonuclease digestion) revealed 10 subtypes. By combining plasmid and monoclonal techniques, all 16 strains were shown to be distinct. Plasmid profiles and monoclonal antibody reactivities of selected strains were stable despite serial passage (greater than 100 times). No plasmid-associated antigen was defined by this panel of monoclonal antibodies. The observed dissociation of plasmid profiles and monoclonal antibody reactivity patterns suggests that accurate epidemiologic typing of L. pneumophila serogroup 1 strains will require use of both techniques.
Identification of Streptococcus sobrinus with monoclonal antibodies
Authors: de Soet J J , van Dalen P J , Appelmelk B J , de Graaff J
Published: January 2020

Identification of Streptococcus sobrinus is often difficult to perform because of the great resemblance of the organism to other oral streptococcal species. Therefore, monoclonal antibodies were prepared which were shown to be highly specific for S. sobrinus. Cross-reactivity with other oral microorganisms has not been observed in an enzyme-linked immunosorbent assay and an immunofluorescence assay. These monoclonal antibodies belonged to the subclass immunoglobulin G2b. To be certain that the strains used in cross-reactivity tests were S. sobrinus, their DNA base composition was measured as a golden standard. Additional tests like colony morphology and sugar fermentation with the API 20 Strep system (Analytab Products, Montalieu-Vercieu, France) were performed. These additional tests turned out to be necessary because 100% correct identification could not be obtained by separate tests. Immunological characterization with the clones OMVU10 and OMVU11 proved to be discriminative between S. sobrinus and other streptococcal species.
Different types of monoclonal antibodies to Ogawa-specific and group-specific antigens of Vibrio cholerae O1
Authors: Ito T , Yokota T
Published: January 2020

Nine monoclonal antibodies to Ogawa-specific antigenic determinants of Vibrio cholerae O1 and seven monoclonal antibodies to the Ogawa-Inaba common antigenic determinants were obtained. Specificities and reactivities were examined by slide or microdilution agglutination methods, along with enzyme-linked immunosorbent assays and immunoblotting analysis. In both the Ogawa-specific and Ogawa-Inaba common groups, it was revealed that there were two types of antibodies. One type showed strong agglutination with both live cells and heat-killed (100 degrees C for 30 min) cells in the microdilution agglutination test and in the slide agglutination test (type 1), while the other showed rather weak agglutination with heat-killed cells, especially in the slide agglutination test (type 2). Electronic measurement of agglutinates from these antibodies revealed that the size of aggregates varied. In the case of the type 2 antibodies, the size of aggregates obtained with heat-killed cells was smaller than those obtained with Formalin-killed cells. Results of enzyme-linked immunosorbent assays and immunoblotting analysis showed that all 16 antibodies were to the lipopolysaccharide of V. cholerae O1.
Urease activity of Proteus penneri
Authors: Mobley H L , Jones B D , Penner J L
Published: January 2020

Ten strains of Proteus penneri isolated from geographically diverse laboratories were tested for urease activity. Cell lysates from urea-induced cells had a mean activity of 4.9 +/- 4.1 mumol of NH3 per min per mg of protein. On nondenaturing 6% polyacrylamide activity gels, the enzymes of P. penneri had very similar electrophoretic mobilities within species and within the Proteus genus but were distinct from the ureases of Providencia and Morganella species. On lower-percentage polyacrylamide, differences in mobilities of the ureases could be detected between the Proteus species. From representative strains, the P. penneri urease was found to be inducible by growth in urea and had an apparent molecular weight of 246,000 +/- 9,000, an isoelectric point of 5.1, and a Km for urea of 14 mM and was inhibitable by acetohydroxamic acid, hydroxyurea, and EDTA. In an in vitro model of struvite formation, a P. penneri strain produced abundant crystals on a glass rod submerged in synthetic urine in the absence but not presence of acetohydroxamic acid (500 micrograms/ml).
Restriction endonuclease analysis of members of the Mycobacterium avium-M. intracellulare-M. scrofulaceum serocomplex
Authors: Wards B J , Collins D M , de Lisle G W
Published: January 2020

Organisms belonging to the Mycobacterium avium-M. intracellulare-M. scrofulaceum (MAIS) serocomplex were subjected to restriction endonuclease analysis (REA) with the enzymes BstEII, PvuII, and BclI. Substantial genetic heterogeneity was observed between members of an authenticated collection of the 31 serotypes. Serotypes 2 and 3 were indistinguishable, however, as were serotypes 5 and 10. No direct correlation could be made between restriction pattern and species identification. REA of serotype 2 and serotype 8 isolates from various geographic locations and animal origins showed that, within limits, the restriction pattern could be used as an index of serotype. Some isolates that were unable to be classified serologically exhibited restriction patterns identical to those of strains that were able to be classified by seroagglutination. The difficulty of interpreting much of the epidemiological data concerning MAIS organisms may be partially explained by the extent of heterogeneity observed by REA. These findings support the contention that the MAIS complex has a substantially greater degree of heterogeneity than has been revealed by traditional methods.
Large production of cholera toxin by Vibrio cholerae O1 in yeast extract peptone water
Authors: Iwanaga M , Kuyyakanond T
Published: January 2020

A large amount of cholera toxin (CT) was produced by Vibrio cholerae O1 cultured in yeast extract-peptone water. The organisms were cultured initially in a stationary test tube (small surface-to-volume ratio) until the end of the exponential phase and subsequently cultured in a shaking flask for 15 to 20 h. By this method (previously reported as the AKI-SW method), most cholera vibrios produced an abundance of CT (up to 64 micrograms/ml), regardless of their biotype and serotype. A substantial amount of CT was produced even in basic peptone water (2% peptone, 0.5% NaCl). Use of sodium bicarbonate, which markedly stimulated CT production in the stationary test tube culture, was undesirable for CT production by the culture method used here. CT production was greatly influenced by culture conditions but was not significantly affected by the composition of the medium.
Antibiotic- and method-dependent variation in susceptibility testing results of Bacteroides fragilis group isolates
Authors: Aldridge K E , Sanders C V
Published: January 2020

The susceptibilities of 36 isolates of the Bacteroides fragilis group to ceftizoxime, cefoxitin, clindamycin, and metronidazole were determined by using the National Committee for Clinical Laboratory Standards agar dilution reference method and a broth microdilution method using anaerobe, brucella, Schaedler, and brain heart infusion broths. MICs that were greater than or equal to fourfold higher or lower than those of the reference method were considered significant. Major and minor discrepancies in susceptibility interpretation (SI) were also noted. Ceftizoxime showed the greatest number of variations and SI discrepancies. In 72% of the cases, MICs in broth were greater than or equal to fourfold lower than those obtained by the reference method, resulting in 33% of the major and 22% of the minor discrepancies in SI. A total of 53% of the isolates were resistant to ceftizoxime by the reference method, but only 11 to 17% were resistant in the various broths. Significant variations in MICs of cefoxitin occurred in 19 to 22% of the isolates; 17 to 19% of the isolates showed major discrepancies and 31 to 58% showed minor discrepancies in SI. A total of 58% of the isolates were resistant to cefoxitin by the reference method, but only 19 to 28% were resistant in the various broths. Significant variations with clindamycin in broths ranged from 32 to 53% and resulted in 3 to 8% of the isolates showing major discrepancies and 33 to 44% showing minor discrepancies in SI. Metronidazole yielded significant variations in MICs in 6 to 28% of the isolates, but no major or minor SI discrepancies were noted. This study indicates that significant differences in susceptibility results, which appear to be method related, can result when isolates of the B. fragilis group are tested. Therefore, studies correlating in vitro results, determined by various methods, to clinical outcome are essential.
Immunoglobulins A and G2a in milks of protein- and calorie-restricted dams
Authors: Elitsur Y , Lee P C , Lebenthal E
Published: January 2020

It is well accepted that breast-feeding enhances the ability of newborns and infants to be protected against infection. Maternal nutritional status may affect this passive immunological defense mechanism because of either the change in the volume of milk or the alteration of the immunological components secreted in the milk. Diet restriction in lactating dams has been shown to influence the secretion of immunoglobulin in their milk. We investigated the specific role of caloric or protein restriction on immunoglobulin A (IgA) and IgG2a secretion in the milk of lactating rats. Both calorie- and protein-restricted dams had lower protein levels (milligrams per milliliter) than did the controls during the initial days of lactation (P less than 0.05). The levels (milligrams per milligram of protein) of IgA and IgG were higher in the milk obtained from calorie-restricted dams during the whole lactation period. The amount of IgA in the milk of protein-restricted rats was higher during 21 days of lactation, while the amount of IgG2a was higher only during the first 2 weeks of the lactation period compared with the respective values for the milk from control dams (P less than 0.05). Rats on a protein-restricted diet had lower IgA and IgG2a levels in their milk than those on a calorie-restricted diet at the second half of the lactation period (P less than 0.05). Our data suggest that the diet-restricted dams had a compensatory mechanism to ensure passive immunological protection for their pups during lactation. The compensation was diminished with a protein-restricted diet compared with a calorie-restricted diet.
Serum antibody response to capsular polysaccharide, outer membrane, and lipooligosaccharide in children with invasive Haemophilus influenzae type b infections
Authors: Claesson B A , Lagergård T , Trollfors B , Gothefors L , Jodal U
Published: January 2020

Serum antibodies against capsular polysaccharide (CPS), outer membrane (OM), and lipooligosaccharide (LOS) from Haemophilus influenzae type b were measured by enzyme-linked immunosorbent assay in acute- and convalescent-phase sera from 21 children between 3 months and 4 years of age with invasive H. influenzae type b infections. As expected, the levels of anti-CPS antibodies in the acute-phase serum samples were low or not detectable, as were the levels of antibodies against LOS. In contrast, all children had detectable antibodies against the OM in the acute-phase serum sample, indicating that they are of little or no importance for protection. An antibody response to CPS was noted in 13 of the 21 patients, mainly in the older children. An antibody response to the OM was seen in 16 patients, with no evident relation to age. The antibody response to the OM preparation, which consisted of proteins and LOS, was probably directed mainly against the OM proteins, since only six children showed a response, usually of low magnitude, of antibodies to LOS.
Comparison of antigen assay and reverse transcriptase assay for detecting human immunodeficiency virus in culture
Authors: Feorino P , Forrester B , Schable C , Warfield D , Schochetman G
Published: January 2020

We compared an antigen capture assay (Abbott Laboratories, North Chicago, Ill.) with a reverse transcriptase assay to identify and quantify human immunodeficiency virus (HIV) in culture. In direct comparisons of serial dilutions of lymphadenopathy-associated virus type 1, the antigen assay was 100-fold more sensitive than the reverse transcriptase assay in detecting the virus. The antigen assay reacted strongly with 60 different HIV isolates but did not cross-react with human T-cell lymphotropic virus type I, human T-cell lymphotropic virus type II, cytomegalovirus, varicella-zoster virus, herpes simplex virus type 1, Epstein-Barr virus, adenovirus type 5, or poliovirus type 1 or with extracts from four different control human cell lines and eight different phytohemagglutinin-stimulated normal human lymphocytes. Peripheral blood lymphocyte samples from 50 individuals were evaluated by both the antigen assay and the reverse transcriptase assay. The cells from the 34 seropositive individuals were all positive by the antigen assay (range, 3 to 9 days; average time, 5.9 days) and the reverse transcriptase assay (range, 7 to 16 days; average time, 9.6 days). Cells from the 16 seronegative individuals were negative by both assays. These results indicate that the antigen assay is an important addition to the monitoring of HIV production in the lymphocytes of infected patients.
Absence of antigenic diversity in Pf155, a major parasite antigen in membranes of erythrocytes infected with Plasmodium falciparum
Authors: Perlmann H K , Berzins K , Wåhlin B , Udomsangpetch R , Ruangjirachuporn W , Wahlgren M , Perlmann P H
Published: January 2020

Pf155 is a merozoite-derived polypeptide antigen which the parasite Plasmodium falciparum deposits in the membranes of erythrocytes at invasion. Eleven laboratory strains or clones of P. falciparum and a large number of isolates obtained from patients from different parts of the world were studied for antigenic diversity in Pf155. Immunoglobulin G antibodies from different serum samples from P. falciparum-infected donors were affinity purified on monolayers of glutaraldehyde-fixed and air-dried erythrocytes infected with P. falciparum of different origins and tested in different combinations by immunoblotting, reinvasion inhibition, and a modified immunofluorescence procedure in which the membranes of recently infected erythrocytes were stained. Similar experiments were performed with monoclonal and oligoclonal antibodies specific for different epitopes in the C-terminal region of Pf155. No strain- or isolate-associated antigenic diversity or size variation of Pf155 was detected, indicating that the immunodominant regions of this antigen are highly conserved throughout the world.
Comparison of a highly automated 5-h susceptibility testing system, the Cobas-Bact, with two reference methods: Kirby-Bauer disk diffusion and broth microdilution
Authors: Murray P R , Niles A C , Heeren R L
Published: January 2020

The results of susceptibility tests performed with the Cobas-Bact system were compared with those of the Kirby-Bauer disk diffusion and the broth microdilution methods. The evaluation included tests with 24 antibiotics against 250 isolates of the family Enterobacteriaceae and 13 antibiotics against 100 gram-positive cocci. Complete agreements between the Cobas-Bact and Kirby-Bauer methods were 82.8 and 84.5% for gram-positive cocci and gram-negative bacilli, respectively. Agreements between the Cobas-Bact and broth microdilution methods were 76.7% for gram-positive cocci and 84.8% for gram-negative bacilli. Complete agreements between the Kirby-Bauer and broth microdilution methods were 87.0% for gram-positive cocci and 92.2% for gram-negative bacilli. Despite generally satisfactory results with most organism-antibiotic combinations tested, additional modifications of the Cobas-Bact system are required to reduce the number of major and very major discrepancies, as well as to permit testing of Pseudomonas spp. and other gram-negative nonfermentative bacilli.
Characterization of Mycobacterium paratuberculosis by gas-liquid and thin-layer chromatography and rapid demonstration of mycobactin dependence using radiometric methods
Authors: Damato J J , Knisley C , Collins M T
Published: January 2020

Thirty-six Mycobacterium paratuberculosis isolates of bovine, caprine, and ovine origins were evaluated by using gas-liquid chromatography (GLC), thin-layer chromatography (TLC), and BACTEC 7H12 Middlebrook TB medium (12A; Johnston Laboratories, Inc., Towson, Md.) in an effort to more rapidly differentiate this group of organisms from other mycobacteria. Bacterial suspensions (0.1 ml) were inoculated by syringe into 7H12 broth containing 2 micrograms of mycobactin P per ml and control broth without mycobactin P. Cultures were incubated at 37 degrees C and read daily with a BACTEC Model 301 (Johnston Laboratories). After 8 days of incubation, the growth index readings for the test broths containing mycobactin P were twice those of the control broths without mycobactin P. Sixty-five isolates of mycobacteria other than M. paratuberculosis were also examined. No difference was noted between the growth index readings of control and mycobactin-containing broths. Except for Mycobacterium avium-Mycobacterium intracellulare, TLC studies differentiated M. paratuberculosis from the other mycobacterial species tested. The GLC data reveal that all M. paratuberculosis isolates had a distinctive peak (14A) which was not found among M. avium-M. intracellulare complex organisms. These data indicate that 7H12 radiometric broth was able to rapidly demonstrate the mycobactin dependence of M. paratuberculosis and GLC and TLC procedures were capable of rapidly differentiating this organism from the other mycobacteria studied.
Modified scrub technique for sampling infant skin microflora
Authors: Keswick B H , Frank D
Published: January 2020

Two techniques for quantitatively recovering normal-flora microorganisms from the skin of infants were compared. A technique using a swab to dislodge microorganisms from the skin compared favorably to a technique using a rubber policeman. The swab was easier to use and is suitable for use on infant skin.
Restriction endonuclease DNA analysis of Clostridium difficile
Authors: Wren B W , Tabaqchali S
Published: January 2020

HindIII restriction enzyme digests of genomic DNA from nine distinct strains of Clostridium difficile were undertaken, and the results were related to those of a previously established typing method based on [35S]methionine-labeled protein profiles. Each of the typed strains identified by its protein profile could also be distinguished by its unique DNA digestion pattern. Analysis of strains isolated from 10 patients during a hospital outbreak of antibiotic-associated colitis revealed identical DNA profiles, confirming a single strain as the source of cross-infection. Characterization of isolates from worldwide sources revealed similar digestion patterns within the same strain type. Restriction endonuclease DNA analysis provides a sensitive and useful technique for studying the epidemiology of C. difficile.
Liver infection caused by Coniothyrium fuckelii in a patient with acute myelogenous leukemia
Authors: Kiehn T E , Polsky B , Punithalingam E , Edwards F F , Brown A E , Armstrong D
Published: January 2020

A case of liver infection caused by Coniothyrium fuckelii is described in a patient with acute myelogenous leukemia. This fungus is found in the soil and can be a pathogen of plants. Coniothyrium spp. are members of the order Sphaeropsidales, an order composed of fungi whose conidiomata are usually pycnidia with the conidiogenous hymenium lining the walls of the locule. Coniothyrium spp. must be differentiated from Phoma spp. and Hendersonula spp., the two most commonly isolated members of the Sphaeropsidales.
Antibody that inhibits human immunodeficiency virus reverse transcriptase and association with inability to isolate virus
Authors: Sano K , Lee M H , Morales F , Nishanian P , Fahey J , Detels R , Imagawa D T
Published: January 2020

Most individuals infected with human immunodeficiency virus (HIV), the causative agent of acquired immune deficiency syndrome, produce an antibody against the viral reverse transcriptase (RT). Our studies show that 67% of HIV-seropositive individuals (33 of 49) produced an antibody that specifically inhibited viral RT enzyme activity. We were able to isolate HIV from only 18% of these individuals (6 of 33). On the other hand, virus was readily isolated from 63% of HIV-seropositive individuals (10 of 16) who did not demonstrate this antibody. Further examination of this RT-inhibiting antibody and its role during virus infection is needed, as it may prove to be of diagnostic, prognostic, or therapeutic value in this study and treatment of acquired immune deficiency syndrome.
Evaluation of Leathers-Awasthi medium for identifying Coccidioides immitis isolates
Authors: Standard P , Kaufman L
Published: January 2020

Leathers-Awasthi medium (LAM) has been recommended for the definitive identification of Coccidioides immitis isolates recovered from clinical specimens. Studies were undertaken to determine the diagnostic reliability of this medium for identifying fungal cultures. A total of 62 fungi, representing 13 C. immitis isolates and 49 similar pathogenic and saprophytic fungi, were tested in parallel by the LAM and exoantigen tests. All of the 13 C. immitis isolates were positive by the exoantigen test, whereas only 11 were positive on LAM. Of the 49 other fungal isolates, 29 were positive on LAM whereas none was positive by the exoantigen test. LAM does not permit the unequivocal identification of C. immitis isolates.
Antiserum to scrapie-associated fibril protein cross-reacts with Spiroplasma mirum fibril proteins
Authors: Bastian F O , Jennings R A , Gardner W A
Published: January 2020

Protease-resistant fibril proteins purified from Spiroplasma mirum and from Creutzfeldt-Jakob disease-infected brain tissues reacted with antisera to scrapie-associated fibrils on Western immunoblot analysis. These data suggest that there are conformational similarities among spiroplasma proteins and infection-specific proteins of the transmissible spongiform encephalopathies.
Osteomyelitis caused by Enterobacter taylorae, formerly enteric group 19
Authors: Westblom T U , Coggins M E
Published: January 2020

The first case of osteomyelitis caused by Enterobacter taylorae is presented. The infection occurred as a complication to an open fracture in an otherwise healthy host. Despite antimicrobial therapy, based on in vitro susceptibilities, it was not possible to establish a microbiologic cure.
Monoclonal antibody for identification of Bacteroides gingivalis lipopolysaccharide
Authors: Millar S J , Chen P B , Hausmann E
Published: January 2020

A monoclonal antibody, BBG-25, raised in BALB/c mice demonstrated specificity for Bacteroides gingivalis lipopolysaccharide. Immunoblotting indicated that this monoclonal antibody does not cross-react with lipopolysaccharide prepared from enterobacterial organisms or from other Bacteroides species.
Microneutralization test for rabies virus based on an enzyme immunoassay
Authors: Mannen K , Mifune K , Reid-Sanden F L , Smith J S , Yager P A , Sumner J W , Fishbein D B , Tong T C , Baer G M
Published: January 2020

We have developed an enzyme immunoassay for rabies virus by using acetone-fixed infected cell cultures as the antigen. This test was used to demonstrate virus-neutralizing antibodies in human and animal sera and was as sensitive as and easier to perform than the rapid fluorescent-focus inhibition technique.
Comparison of two rapid culture methods for detection of cytomegalovirus in clinical specimens
Authors: Swenson P D , Kaplan M H
Published: January 2020

The conventional virus isolation technique was compared with a 24-h shell vial centrifugation culture technique and with a 48-h tube culture method for the detection of cytomegalovirus (CMV) in MRC-5 cells. Of 200 clinical specimens tested, 41 were positive for CMV by at least one procedure. Indirect immunoperoxidase staining was positive for 32 (78.0%) of 41 specimens in the tube culture method and for 30 (73.2%) of 41 specimens in the shell vial centrifugation method. CMV was detected in 23 (56.1%) of 41 specimens by the development of cytopathic effect within 14 days.
Production and purification of Streptococcus pneumoniae hemolysin (pneumolysin)
Authors: Kanclerski K , Möllby R
Published: January 2020

Pneumolysin was found to be produced by 112 of 113 clinical isolates of Streptococcus pneumoniae and to be an intracellular hemolysin. A 10-liter-scale fermentor production and purification procedure was developed for this hemolysin. The culture was concentrated by filtration 10 times before centrifugation. The cellular content was purified by ion-exchange chromatography, covalent thiopropyl gel chromatography, and gel filtration. One batch operation resulted in 6 mg of highly purified pneumolysin, with a yield of 66% and a specific activity of 1,400,000 hemolytic units per mg. The pneumolysin had a molecular weight of 53,000 and an isoelectric point of 5.2. The purification method developed will be of value in future studies on this hemolysin.
Rapid presumptive identification of streptococci directly from blood cultures by serologic tests and the L-pyrrolidonyl-beta-naphthylamide reaction
Authors: Gordon L P , Damm M A , Anderson J D
Published: January 2020

The value of the Strepslide kit for the rapid presumptive identification of streptococci directly from blood cultures without prior determination of hemolysis patterns was assessed and compared with that of the Streptex and Phadebact streptococcus kits. Studies involved 94 simulated and 60 clinical isolates of 83 streptococci. The Streptex and Strepslide kits had excellent sensitivity and specificity for group A, B, F, and G organisms, and the Phadebact kit had excellent sensitivity and specificity for groups B and G. Group C reactions usually occurred with all of the streptococcus kits with pneumococci and occasionally with alpha-hemolytic streptococci. Although these kits were unacceptable for group C and D organisms, enterococci which were common clinical isolates could be directly identified in blood cultures by a supplementary rapid L-pyrrolidonyl-beta-naphthylamide biochemical test. Direct application of the Phadebact pneumococcus kit to blood cultures was also assessed with 29 isolates of 20 organisms. The specificity was good, but the sensitivity was only 65.5%.
Effect of heat or chemical treatment on leptospiral antigens
Authors: Pope V , Johnson R C
Published: January 2020

The use of bacterins is one of the primary methods in the control of leptospirosis in domestic animals, especially cattle, swine, and dogs. Bacterins have been made using chemically treated or heat-inactivated organisms. Many of the initial studies indicated that the bacterins gave complete protection, whereas later reports found that some inactivation methods resulted in bacterins that protect against death but not against kidney infection and renal shedding. This raised the possibility that some of the antigens had been altered. To investigate this possibility, we heat or chemically treated Leptospira interrogans serovar icterohaemorrhagiae CF-1, L. interrogans serovar canicola Moulton, L. interrogans serovar grippotyphosa SC4397, L. interrogans serovar hardjo Hardjoprajitno, and L. interrogans serovar pomona MLS. Temperatures used to determine alterations in antigens were 50, 56, 80, 100, and 121 degrees C. The chemicals used were formaldehyde, phenol, and thimerosal. Analysis was done using Laemmli gels and Western blots. We found that heating at 50 or 56 degrees C had the smallest effect on antigens, whereas heating at 80 or 100 degrees C caused the appearance of high-molecular-weight bands on Western blots. Heating at 121 degrees C caused almost all the bands to disappear, in both the stained gel and the Western blot. Both phenol and Formalin treatment altered proteins, whereas thimerosal treatment appeared to have little effect compared with heating at 50 degrees C.
Rapid detection of group B streptococcal antigen in human amniotic fluid
Authors: Moriarty R A , Smith L P , Hemming V G , Fischer G W
Published: January 2020

Infants exposed in utero to group B streptococcus (GBS)-infected human amniotic fluid (HAF) are at high risk for serious infection. Latex particle agglutination (LPA) tests are not approved for detection of GBS in HAF. Two LPA systems, Patho-Dx Strep B and Wellcogen Strep B, were used to test unfiltered sterile HAF and filtered HAF containing concentrations of GBS carbohydrate from 0.2 to 100 micrograms/ml. Four different processing techniques were used to prevent nonspecific LPA: EDTA, nitrous acid, enzyme, and nitrous acid-heat. GBS (10(2) CFU/ml) was inoculated into filtered HAF, incubated, sampled serially, processed with enzyme, and tested by LPA. Unprocessed, unfiltered HAF showed 33% nonspecific agglutination when tested by LPA. Processing of HAF removed nonspecific agglutination and improved GBS antigen detection. Without processing, LPA could not detect less than 100 micrograms of GBS carbohydrate per ml. With nitrous acid or enzyme processing, as little as 0.2 microgram/ml could be detected. Results were easier to read after enzyme processing than after nitrous acid processing. Although both LPA systems were equally efficient, testing was easier with the Patho-Dx system. After enzyme processing, LPA could detect as few as 10(4) CFU/ml when agglutination was read with a 4 X hand lens. Substances in HAF induce false-positive reactions during LPA testing. Processing removes the interference and improves the detection of GBS. LPA testing of HAF may allow earlier identification and treatment of infants at risk for serious GBS infection.
Bifidobacterium, Bacteroides, and Clostridium spp. in fecal samples from breast-fed and bottle-fed infants with and without iron supplement
Authors: Mevissen-Verhage E A , Marcelis J H , de Vos M N , Harmsen-van Amerongen W C , Verhoef J
Published: January 2020

Bifidobacterium, Bacteroides, and Clostridium spp. isolated from the feces of 23 neonates during the first 3 months of life were identified. Of the 23 neonates, 10 were breast fed, 6 received an infant formula with iron supplement (5 mg/liter), and 7 received the formula without iron supplement (iron concentration, less than 0.5 mg/liter). The Bifidobacterium spp. most frequently isolated from the three groups of infants were B. longum, B. breve, B. adolescentis, and B. bifidum. The bacteroides spp. most frequently isolated were B. fragilis and B. vulgatus. The most common Clostridium sp. in the three groups of infants was C. perfringens. The type of milk did not select for species of Bifidobacterium, Bacteroides, or Clostridium, except for Clostridium butyricum, which was isolated significantly more often from bottle-fed infants with iron supplement than from the other groups, and Clostridium tertium, which was more often isolated from breast-fed infants. The species of the three anaerobic genera did not persist for a long period of time in the three groups of infants.
Age-related infections with rotavirus, rotaviruslike virus, and atypical rotavirus in turkey flocks
Authors: Theil K W , Saif Y M
Published: January 2020

The genome electropherotyping technique was used in longitudinal surveys to detect group A rotavirus, rotaviruslike virus (RVLV), atypical rotavirus (ATR), and reovirus in intestinal contents or fecal specimens collected from turkeys in 10 commercial and 2 research station flocks. These viruses were detected in turkeys from 8 to 10 commercial flocks surveyed. Of 278 specimens collected from turkeys less then 29 days old in commercial flocks, 79 (28.4%) contained one or more viruses, whereas only 1 of 120 specimens collected from turkeys older than 28 days had virus. Viruses were detected in commercial turkeys between 3 and 35 days old, and over a third of the specimens collected from birds during their first week of life were positive for group A rotavirus. Between 8 and 28 days of age, commercial turkeys were infected with group A rotavirus, RVLV, ATR, and reovirus. ATR was the only virus detected in birds older than 28 days. Overall, group A rotavirus and RVLV were each detected in 39 specimens, and ATR was detected in 7 specimens; reovirus was detected in 2 specimens. Eight of the positive specimens contained two viruses. All 102 specimens collected from turkeys 1 to 56 days old in the two research station flocks were negative for virus.
Detection of enterotoxigenic Escherichia coli by dot blot hybridization with biotinylated DNA probes
Authors: Bialkowska-Hobrzanska H
Published: January 2020

A dot blot hybridization test was developed for the detection of enterotoxigenic E. coli without the use of radioisotopes. Three biotin-labeled DNA (Bio-DNA) probes corresponding to structural genes specifying heat-labile and heat-stable enterotoxins of porcine and human origin were prepared by random priming; label incorporation was significantly higher than that obtained from the use of nick translation. Bio-DNA probes were highly specific when reacted with protein- and RNA-free DNA preparations in a dot blot hybridization assay. The Bio-DNA probe, in which 40% of available thymidines were replaced by a biotin-labeled deoxyuridine, readily detected 160 pg of target DNA mixed with 6 micrograms of carrier DNA. The minimum amount of total DNA required for reliable identification of a single-copy enterotoxin gene of porcine origin within a 5,000-kilobase chromosome was found to be approximately 5 micrograms. Complete agreement among the results of Bio-DNA probe hybridization, [32P]DNA hybridization, and biological assay was demonstrated for 15 (100%) of the clinical isolates. This procedure provides a more suitable approach for the diagnosis of enterotoxigenic E. coli infections in clinical settings than the hybridization assay based on 32P-labeled DNA probes.
Pythium insidiosum sp. nov., the etiologic agent of pythiosis
Authors: De Cock A W , Mendoza L , Padhye A A , Ajello L , Kaufman L
Published: January 2020

Pythium insidiosum sp. nov., the etiologic agent of pythiosis, a cosmopolitan disease of horses, cattle, and dogs, is described and illustrated.
Electrophoretic and immunoblot analyses of Rhizopus arrhizus antigens
Authors: Wysong D R , Waldorf A R
Published: January 2020

Four antigen preparations from Rhizopus arrhizus were made and analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and column chromatography. Electrophoretic analyses of these antigens indicated that there are 18 to 28 component bands with a molecular mass range of approximately 10,500 to 83,000 daltons. Seven of these bands appear to be components common to three antigen preparations. Several of the bands identified by SDS-PAGE were composed of glycoproteins or carbohydrates as determined by their affinity for concanavalin A. Western blots, using sera from five patients with mucormycosis, consistently identified five different determinants in the R. arrhizus antigens separated by SDS-PAGE. This suggests that several of the Rhizopus antigens are present during mucormycosis. Four of the antigenic determinants recognized by patient sera reacted with the concanavalin A-peroxidase stain, indicating that they are composed of glycoproteins or carbohydrate. Enzyme-linked immunosorbent assays of sera from five patients with mucormycosis and with rabbit antisera resulted in antibody titers ranging from 1:64 to 1:32,000 for the R. arrhizus antigens.
Immunoglobulin level in donor blood reactive for antibodies to human immunodeficiency virus
Authors: Nath N , Wunderlich C , Darr F W , Douglas D K , Dodd R Y
Published: January 2020

Blood samples from 98 asymptomatic volunteer blood donors, including 55 that were reactive for antibodies to human immunodeficiency virus (HIV) in Western blot (WB) assay, were tested for levels of immunoglobulin G (IgG), IgM, and titer of antibodies to HIV, cytomegalovirus, and herpes simplex virus. Levels of IgG were significantly elevated (P less than or equal to 0.001) in donors with specific anti-HIV reactivity. A total of 69% of donors with anti-HIV had IgG levels of greater than or equal to 12 mg/ml, and 44% had IgG levels of greater than or equal to 14.5 mg/ml. Levels of IgM were not significantly different among WB-reactive and nonreactive donors. The titer of anti-HIV was significantly (P less than 0.02) correlated with IgG levels among donors reactive in the WB assay. Elevation of IgG, however, was not significantly associated with the presence of anticytomegalovirus or anti-herpes simplex virus antibodies. The data show that elevation of IgG may represent an early manifestation of HIV infection before the development of clinical symptoms of acquired immunodeficiency syndrome.
Membrane filtration enzyme immunoassay, a novel, rapid method for measurement of virus-specific immunoglobulins G and M and detection of viral antigens
Authors: Barnett G R , Tannock G A , Bryce D A
Published: January 2020

A novel membrane filtration enzyme immunoassay (MF EIA) is described in which virus-antibody complexes formed are trapped onto the surface of membranes with low protein-binding affinity by vacuum filtration. Class-specific immunoglobulin G (IgG) or IgM antibody was measured by adding enzyme-conjugated antiimmunoglobulin and incubating prior to the final wash and addition of enzyme substrate. Influenza A virus-specific IgG antibodies measured by MF EIA showed similar sensitivity for detecting seroconversion in volunteers administered influenza virus subunit vaccines and subtype specificity comparable to that observed by the hemagglutination inhibition technique. Cytomegalovirus-specific IgG antibodies measured by MF EIA with commercially available complement fixation antigens gave results similar to those of conventional enzyme-linked immunosorbent assay and complement fixation tests. The MF EIA method is also suitable for detection of rotavirus antigen in feces.
Hemo-De as substitute for ethyl acetate in formalin-ethyl acetate concentration technique
Authors: Neimeister R , Logan A L , Gerber B , Egleton J H , Kleger B
Published: January 2020

In comparative studies, Hemo-De (PMP Medical Industries, Inc., Irving, Tex.) was found to be a suitable replacement for ethyl acetate in the Formalin-ethyl acetate concentration technique. With essentially equivalent recovery rates for both procedures, the Formalin-Hemo-De concentration technique is considered to be the preferred technique because Hemo-De is less toxic and less flammable and does not present disposal problems, and its cost is approximately one-fourth that of ethyl acetate.
ATP measurements obtained by luminometry provide rapid estimation of Ureaplasma urealyticum growth
Authors: Stemler M E , Stemke G W , Robertson J A
Published: January 2020

ATP content obtained by luciferin-luciferase luminometry with commercially available reagents provided rapid estimates of Ureaplasma urealyticum populations. Each cell contained about 4.7 X 10(-18) mol of ATP. We could detect 10(4) CCU50 (color change unit50) per 100 microliters. We correlated urease activity with growth and confirmed the differential response of ureaplasma strains to Mn2+.
DNase production by Clostridium septicum
Authors: Swiatek P J , Allen S D , Siders J A , Lee C H
Published: January 2020

Sixty-two Clostridium septicum isolates were assayed for extracellular DNase activity. All of the C. septicum isolates tested produced greater DNase activity than did the other DNase-producing clostridial isolates tested. The molecular weight of the DNase of C. septicum was determined to be approximately 45,000. DNase is a major extracellular protein produced by this organism.
Rapid catalase supplemental test for identification of members of the family Enterobacteriaceae
Authors: Chester B , Moskowitz L B
Published: January 2020

A simple, rapid, semiquantitative slide catalase test useful for differentiating members of the family Enterobacteriaceae is described. Judging by the time required for appearance of oxygen bubbles in 3% hydrogen peroxide, the immediate catalase reactors were Yersinia, Serratia, Proteus, Morganella, Providencia, Cedecea, and Hafnia spp. The delayed catalase reactors were Escherichia, Shigella, Klebsiella, Enterobacter, Salmonella, Citrobacter, Edwardsiella, Kluyvera, and Tatumella spp. This information is especially useful for differentiating Serratia from Enterobacter spp. and Yersinia from Escherichia and Shigella spp.
Presence of hepatitis B virus DNA in serum of surface-antigen-seronegative immunocompromised patients
Authors: Pao C C , Yang W L , Wu S Y , Lai G M , Shih L Y , Sun C F , Liaw Y F
Published: January 2020

We compared the prevalence of serum hepatitis B virus (HBV) DNA in cancer patients who were immunocompromised with that in healthy subjects. Testing positive for serum HBV DNA were 27 of the 232 (11.6%) surface-antigen-negative cancer patients and 7 of the 382 (1.8%) surface-antigen-negative healthy subjects. These data suggest that the negative serology, at least in immunocompromised individuals, is probably not sufficient to exclude HBV infection.
Lim group B Strep Broth and coagglutination for rapid identification of group B streptococci in preterm pregnant women
Authors: Lim D V , Morales W J , Walsh A F
Published: January 2020

A total of 147 preterm pregnant women at Orlando Regional Medical Center were screened for group B streptococci by using Lim Group B Strep Broth (GIBCO Laboratories, Madison, Wis.) and the Phadebact Strep B Test (Pharmacia Diagnostics, Piscataway, N.J.). Test results were available within 20 h of culture and, in the case of heavily colonized women, within 5 h. This procedure is useful in rapid diagnosis of preterm pregnant women for group B streptococcal colonization.