bluuebunny/crossref_metadata_2025 huggingface dataset:
Inability of cephalothin testing to predict cefprozil susceptibility
Authors: Fung-Tomc J , Stickle T , Doyle C , Huczko E , Kessler R E
Published: January 2020

The 30-micrograms cefprozil disk and the cephalosporin class (30-micrograms cephalothin) disk were compared for their abilities to predict cefprozil susceptibility by agar disk diffusion testing. High error (5.02% major and 14.11% minor) rates were encountered with the cephalothin disk and were most frequently observed for Escherichia coli and Enterococcus faecalis. The cefprozil disks resulted in rates of 0.05% very major, 0% major, and 3.72% minor errors. Thus, the 30-micrograms cefprozil disk is more desirable for predicting cefprozil susceptibility.
Characterization of human papillomavirus type 66 from an invasive carcinoma of the uterine cervix
Authors: Tawheed A R , Beaudenon S , Favre M , Orth G
Published: January 2020

Human papillomavirus (HPV) DNA sequences coexisting with HPV16 and HPV45 were cloned from an invasive cervical carcinoma. The cloned HPV was shown to be a novel type, named HPV66, and is related to HPV56 (an HPV detected in cervical cancer). After screening 160 anogenital biopsies, four specimens exhibited histological features of intraepithelial neoplasia and contained HPV66 sequences. Of these, three were found to be associated with another HPV type.
Performance of a nonisotopic DNA probe for detection of Chlamydia trachomatis in urogenital specimens
Authors: Kluytmans J A , Niesters H G , Mouton J W , Quint W G , Ijpelaar J A , Van Rijsoort-Vos J H , Habbema L , Stolz E , Michel M F , Wagenvoort J H
Published: January 2020

The Gen-Probe PACE 2 assay (GP), a nonisotopic DNA probe, was evaluated by using cell culture as the method of reference. Specimens were collected from 260 men and 482 women visiting the outpatient department for sexually transmitted diseases at the University Hospital in Rotterdam, The Netherlands. The prevalences of Chlamydia culture-positive men and women were 13.2 and 8.6%, respectively. Sensitivity values for the male and female patients were 70.6 and 92.7%, respectively. Specificity values for these groups were 98.2 and 97.7%, respectively. Sensitivity was significantly lower when the number of inclusions in cell culture was low. Samples which showed a discordance between cell culture and GP results were retested by the polymerase chain reaction. If the results of the polymerase chain reaction were considered as the points of reference, the sensitivity and specificity of both GP and cell culture could be calculated. The performance of GP for females was comparable to that of cell culture. In males, the sensitivity of GP was considerably lower than that of cell culture (77.2 versus 91.4%), while specificity was somewhat higher (99.6 versus 99.1%). Compared with cell culture, the GP is a relatively simple and rapid test that is suitable for diagnosing Chlamydia infections in urogenital specimens.
Rhodococcus equi plasmids: isolation and partial characterization
Authors: Tkachuk-Saad O , Prescott J
Published: January 2020

Fifty-four strains of Rhodococcus equi from different clinical sources (mainly horses and pigs) were examined for their plasmid content by two screening methods. Plasmids were detected in 49 of 54 strains. A plasmid of approximately 80 kb was isolated from 21 of 22 isolates from horses and 20 of 28 isolates from pigs, and a 105-kb plasmid was isolated from 7 of 28 isolates from pigs. The 80-kb plasmid was significantly associated with strains of equine rather than porcine origin, and the 105-kb plasmid was significantly associated with strains of porcine origin. The type strain, ATCC 6939, consistently failed to yield a plasmid. Restriction enzyme analysis of purified plasmid DNA confirmed the relatedness of the 80-kb plasmids isolated from strains of equine and porcine origin. More differences between the restriction patterns of plasmids from strains isolated from horses and from pigs than among strains from either species were observed. Restriction enzyme analysis also showed relatedness of the 105-kb plasmid to the 80-kb plasmid. Three strains shown by others to be virulent in horses or mice possessed the 80-kb plasmid, whereas three other strains not virulent for horses or mice lacked the plasmid, although one had the 105-kb plasmid. There was a significant but not perfect association between the presence of the 80-kb plasmid and production of a diffuse 17.5-kDa thermoregulated, virulence-associated protein. Further study is needed to determine whether this plasmid is associated with virulence in R. equi.
Development of verotoxin 2- and verotoxin 2 variant (VT2v)-specific oligonucleotide probes on the basis of the nucleotide sequence of the B cistron of VT2v from Escherichia coli E32511 and B2F1
Authors: Hii J H , Gyles C , Morooka T , Karmali M A , Clarke R , De Grandis S , Brunton J L
Published: January 2020

We and others have noted that there are serological differences between verotoxin 2 (VT2) (also known as Shiga-like toxin II) produced by Escherichia coli C600(933W) and the VT2 variant (VT2v) produced by strain E32511. Recent reports have described nucleotide sequence differences between the VT2v B subunit cistron of E32511 and B2F1 and that of VT2. We have confirmed the sequence differences and have used them to design oligonucleotide probes which differentiate the B subunit cistron of VT2v from that of VT2. Isolates of VT-producing E. coli obtained from human as well as food and veterinary sources were classified according to the toxin phenotype by using a toxin neutralization assay with VT2-specific monoclonal antibody and VT2v-specific polyclonal antisera. Using the oligonucleotide probes in colony hybridization, we detected 35 of 35 VT2 producers and 16 of 16 VT2v producers. One VT2 producer was falsely identified as containing the VT2v gene. The E32511 strain in our collection hybridized only with the VT2-specific probe. Southern hybridization of radiolabeled oligonucleotide probes showed that strains carried zero to one copy of the VT2 gene and zero to two copies of the VT2v gene. We conclude that colony hybridization with the VT2- and VT2-specific probes is highly predictive of the toxin phenotypes in the clinical isolates described in this study.
Immunoglobulin binding by Tritrichomonas foetus
Authors: Corbeil L B , Hodgson J L , Widders P R
Published: January 2020

A better method for diagnosis of bovine trichomoniasis is needed because culture is slow and somewhat lacking in sensitivity. Immunodiagnosis of Tritrichomonas foetus infection usually involves detection of antigen-antibody reactions with an anti-immunoglobulin conjugate. However, nonspecific immunoglobulin (Ig), bound to the surface of T. foetus, would also be detected by an anti-Ig conjugate and thus would interfere with the specificity of the immunoassay. The goals of this study were to define the binding of bovine immunoglobulins to T. foetus. To determine whether nonimmune binding of Ig to T. foetus occurs, we immunized rabbits with organisms that had been grown in medium containing normal bovine serum and vigorously washed three times with phosphate-buffered saline. The rabbit antiserum had similar titers to T. foetus and to normal bovine serum by enzyme-linked immunosorbent assay (ELISA). Furthermore, two bovine serum proteins were immunoprecipitated by the rabbit antiserum in an immunoelectrophoretogram. One of the serum proteins had a distribution characteristic of IgG2. The rabbit antiserum was then shown to react with purified bovine IgG and IgM by ELISA. Reactivity to IgG was greater. To identify the IgG subisotypes bound and to confirm nonimmune binding of Ig, we grew T. foetus in agammaglobulinemic fetal calf serum and reacted it with IgG1, IgG2, and IgM specific for dinitrophenol (DNP) in ELISA. The binding of IgG2 was greatest, that of IgG1 was next, and that of IgM was least. Little competitive inhibition by DNP was detected, indicating that binding of DNP-specific antibodies was predominantly nonimmune rather than antigen-specific Ig binding. We also demonstrated that T. foetus grew well in medium containing agammaglobulinemic fetal calf serum or serum made agammaglobulinemic by ammonium sulfate precipitation of Igs. This may overcome the problem of low specificity in diagnostic assays as a result of antigen with Ig bound by nonimmune mechanisms.
Group G streptococcal lymphadenitis in rats
Authors: Corning B F , Murphy J C , Fox J G
Published: January 2020

Group G streptococci which have been isolated from the oral flora of rats are also normal inhabitants of the human skin, oropharynx, gastrointestinal tract, and female genital tract. This group of streptococci can cause a wide variety of clinical diseases in humans, including septicemia, pharyngitis, endocarditis, pneumonia, and meningitis. Ten days after oral gavage with 7,12-dimethylbenz[a]anthracene, 12 of 22 two-month-old, female, outbred, viral-antibody-free rats presented with red ocular and nasal discharges and marked swelling of the cervical region. Various degrees of firm, nonpitting edema in the region of the cervical lymph nodes and salivary glands as well as pale mucous membranes and dehydration were observed. Pure cultures of beta-hemolytic streptococci were obtained from the cervical lymph nodes of three rats that were necropsied. A rapid latex test system identified the isolates to have group G-specific antigen. These streptococcal isolates fermented trehalose and lactose but not sorbitol and inulin and did not hydrolize sodium hippurate or bile esculin. A Voges-Proskauer test was negative for all six isolates. Serologic tests to detect the presence of immunoglobulin G antibody to rat viral pathogens and Mycoplasma pulmonis were negative. Histopathologic changes included acute necrotizing inflammation of the cervical lymph nodes with multiple large colonies of coccoid bacteria at the perimeter of the necrotiz zone. To our knowledge, this is the first report of naturally occurring disease attributed to group G streptococci in rats.
Isolation and characterization of an Ehrlichia sp. from a patient diagnosed with human ehrlichiosis
Authors: Dawson J E , Anderson B E , Fishbein D B , Sanchez J L , Goldsmith C S , Wilson K H , Duntley C W
Published: January 2020

A new disease was recognized in the United States in 1986. The etiologic agent, although not previously isolated from a human, appeared to be serologically related to Ehrlichia canis, a canine leukotropic rickettsia. We obtained blood specimens from 27 febrile patients with a history of tick exposure. Leukocytes from 24 patients not treated with tetracycline were placed onto a monolayer of DH82 cells. We performed indirect immunofluorescence on sera from all 27 febrile patients as well as sera from 12 patients with previously diagnosed ehrlichiosis. Intractoplasmic inclusions were first observed in culture 35 days after the addition of infected blood from one patient. Partial sequencing of the rRNAs from the human isolate and E. canis indicated that they are 98.7% related. Positive indirect immunofluorescence reactions to the human isolate were obtained for all 12 previously diagnosed patients and for 33% of the 27 febrile patients. Two patients were seropositive for the human isolate but not for E. canis. No sera were positive for E. canis and negative for the human isolate. We report the isolation of a previously unrecognized Ehrlichia sp. that appears to be the etiologic agent of human ehrlichiosis. Serologic data (range of antibody titers, 256 to 32,768) in combination with rRNA sequencing indicated that the newly isolated Ehrlichia sp. is similar, but not identical, to E. canis.
Differentiation of Streptococcus uberis from Streptococcus parauberis by polymerase chain reaction and restriction fragment length polymorphism analysis of 16S ribosomal DNA
Authors: Jayarao B M , Doré J J , Baumbach G A , Matthews K R , Oliver S P
Published: January 2020

Streptococcus uberis type II has been proposed recently as a separate species designated Streptococcus parauberis (A. M. Williams and M. D. Collins, J. Appl. Bacteriol. 68:485-490, 1990). Differentiation of S. parauberis from S. uberis has been possible only by DNA-DNA hybridization or 16S rRNA sequencing, since the biochemical and serological characteristics of the two species are indistinguishable. A simple and reliable technique was developed for differentiating S. parauberis (S. uberis type II [ATCC 13386]) from S. uberis (S. uberis type I [ATCC 9927, ATCC 13387, and ATCC 27958]) by restriction fragment length polymorphism (RFLP) analysis of 1.4-kb 16S ribosomal DNA (rDNA). Oligonucleotide primers complementary to 16S rRNA genes were used to amplify 16S ribosomal gene fragments from genomic DNA by polymerase chain reaction. The 1.4-kb 16S rDNA fragment was digested with ScaI, NspI, DdeI, and AvaII restriction endonucleases. Restriction fragments produced by all four restriction endonucleases were characteristic for each species. RFLP analysis of 16S rDNA from 24 "S. uberis" isolates obtained from mammary secretions of dairy cows indicated that all 24 isolates were indeed S. uberis.
Yersinia enterocolitica isolated from two cohorts of young children in Santiago, Chile: incidence of and lack of correlation between illness and proposed virulence factors
Authors: Morris J G , Prado V , Ferreccio C , Robins-Browne R M , Bordun A M , Cayazzo M , Kay B A , Levine M M
Published: January 2020

Yersinia enterocolitica was isolated from children in two cohorts in Santiago, Chile. In a cohort containing a cross section of children aged 0 to 4 years, Y. enterocolitica was isolated from stool samples of 1.1% of children with diarrhea and 0.2% of age-matched control children. In a subgroup of this cohort from which weekly stool samples were obtained from all children irrespective of clinical status, 6% of children had asymptomatic Yersinia infections. In a birth cohort (with a greater representation of children less than 1 year of age and a significantly higher rate of diarrhea), Y. enterocolitica was isolated from 1.9% of children with diarrhea and 0.6% of controls (P = 0.05). Biogroup 1A strains (which lacked traditional phenotypic and molecular markers for pathogenicity) were isolated from seven children with diarrhea but from no control children in the birth cohort (P = 0.02). All other isolates, including all isolates from asymptomatic children, were "pathogenic" strains in biogroup 4, serogroup O3; no association between these isolates and occurrence of disease was found. Y. enterocolitica is found among young children in Santiago, with asymptomatic infections not uncommon occurrences. However, questions about the association between previously described virulence factors and diarrheal illness remain.
Serotyping of Canadian isolates of Treponema hyodysenteriae and description of two new serotypes
Authors: Li Z S , Bélanger M , Jacques M
Published: January 2020

A total of 30 isolates of Treponema hyodysenteriae collected in the Saint-Hyacinthe (Quebec, Canada) area were serotyped by agar gel double immunodiffusion by using extracted lipopolysaccharide and hyperimmune rabbit antisera. Only 17% (5 of 30) of the isolates were typed with antisera specific for each of the seven known serotypes of T. hyodysenteriae. Antisera raised against 11 untypeable local isolates were then produced and tested against each lipopolysaccharide extract. Results showed two serologically distinct groups among 21 of the 25 untypeable isolates. The isolates in each group shared identical antigens. No detectable reactions could be observed between antisera raised against these 11 isolates and the antigens extracted from 7 reference serotype strains. On the basis of these results, two new serotypes of T. hyodysenteriae, serotypes 8 and 9, are proposed. We also propose isolate FM 88-90 as the reference strain for serotype 8 and isolate FMV 89-3323 as the reference strain for serotype 9. These two new serotypes, which represented 70% of the isolates tested, seem to be the major serotypes found in the province of Quebec.
Use of multiple markers for investigation of an epidemic of Shigella sonnei infections in Monroe County, New York
Authors: Yagupsky P , Loeffelholz M , Bell K , Menegus M A
Published: January 2020

Antibiotic susceptibility patterns, plasmid profiles, and endonuclease restriction analysis of plasmid DNA were used in the investigation of an epidemic of Shigella sonnei infections in Monroe County, New York, in 1988 and 1989. The epidemic peaked during the winter, included the simultaneous transmission of the disease from person to person and from common food sources, and especially affected inhabitants of the poor, inner-city neighborhoods, young children of both sexes, and women. Resistance to ampicillin, tetracycline, or trimethoprim-sulfamethoxazole, encoded in a 70-MDa plasmid, was found in most of the examined isolates. Unexpectedly, isolates from patients involved in a food-borne outbreak exhibited three different antibiotic susceptibility patterns, suggesting deletion of antibiotic resistance determinants in some strains. Antibiograms clearly separated food-borne outbreak-related and non-foodborne outbreak-related strains, distinguished more strains than did the plasmid profiles, and were useful in tracing the dissemination of individual isolates in the community. Restriction endonuclease analysis substantially increased the discriminatory value of plasmid profiles and validated the antibiogram results. The present study illustrates the complexity of epidemics of S. sonnei infections and shows the value of combining different biological markers in the investigation.
Antibodies to seven rotavirus serotypes in cord sera, maternal sera, and colostrum of German women
Authors: Brüssow H , Sidoti J , Lerner L , Rahim H , Eckstein W , Werchau H , Mietens C
Published: January 2020

Forty percent of colostrum samples from German women showed neutralizing antibody titers of greater than or equal to 50 to rotavirus (RV) serotypes 1, 3, 4, and 6. Antibody to serotypes 2, 8, and 9 was less prevalent. Titers are, however, too low to indicate an important effect of colostrum on the RV vaccine take rate. On the other hand, about 50% of the cord serum samples showed high neutralizing-antibody titers to serotypes 1, 3, and 4, which could interfere with the take rate of RV vaccines based on these serotypes in very young infants.
Discrimination of hepatitis C virus in liver tissues from different patients with hepatocellular carcinomas by direct nucleotide sequencing of amplified cDNA of the viral genome
Authors: Chou W H , Yoneyama T , Takeuchi K , Harada H , Saito I , Miyamura T
Published: January 2020

We investigated the presence of the hepatitis C virus (HCV) genome in liver tissues of eight different patients with hepatocellular carcinoma by using the reverse transcriptase polymerase chain reaction (PCR) method. RNA was extracted separately from cancerous and peripheral noncancerous portions of the liver tissues of each patient. For reverse transcriptase PCR, we used sets of primers derived either from nonstructural region 3 (the NS3 region) or from the nucleocapsid-envelope (C/E) region of the HCV genome. The nucleotide sequences of the amplimers were directly determined without subcloning. Of 16 samples tested, cDNA of the HCV genome was detected in 2 cancerous tissues and in 4 noncancerous tissues by either pair of primers. Nucleotide sequences of HCV cDNA fragments amplified from cancerous and peripheral noncancerous tissues from the same patients were identical. However, 4.4 to 6.3% and 7.5 to 11.3% sequence variation was observed in NS3 and C/E regions, respectively, among cDNA fragments from different patients. The result indicated that the HCV genome detected in a given patient is distinguishable from that in others by a simple direct nucleotide sequencing of the reverse transcriptase PCR products.
Evaluation of a commercial measles virus immunoglobulin M enzyme immunoassay
Authors: Mayo D R , Brennan T , Cormier D P , Hadler J , Lamb P
Published: January 2020

Paired serum samples from 93 patients suspected of having measles were assayed for measles virus-specific immunoglobulin M (IgM) antibodies by an enzyme immunoassay (EIA), and the results were compared with results from a complement fixation assay and an EIA for measles virus IgG. By using significant serologic rises as the standard for comparison, the IgM EIA assay had a sensitivity of 85.7%, a specificity of 81.3%, a positive predictive value of 95.7%, and a negative predictive value of 54.2%. This assay can be expected to perform well in outbreak situations.
Yersinia enterocolitica: a frequent seasonal stool isolate from children at an urban hospital in the southeast United States
Authors: Metchock B , Lonsway D R , Carter G P , Lee L A , McGowan J E
Published: January 2020

From 1 December 1988 through 28 February 1991, 7,290 rectal swab specimens received in our laboratory were screened for Yersinia enterocolitica. A total of 76 patients had Y. enterocolitica isolated from their stool samples. Of these patients, 59 (77.6%) were 12 months old or younger. Y. enterocolitica was second only to Salmonella spp. in this age group. Routine screening for Y. enterocolitica may be warranted in hospitals serving large pediatric populations.
Characterization of yellow-pigmented enterococci from severe human infections
Authors: Pompei R , Lampis G , Berlutti F , Thaller M C
Published: January 2020

Four strains of yellow-pigmented enterococci that resembled the species Enterococcus casseliflavus were isolated from patients who had undergone surgical treatment. They were substantially homologous in terms of biochemical properties, antibiotic susceptibilities, and plasmid DNA profiles. Yellow-pigmented enterococci could be another potentially important cause of nosocomial infection in surgical units.
Isoprenoid quinones of "Afipia" spp
Authors: Moss C W , Daneshvar M I , Hollis D G , Birkness K A
Published: January 2020

The isoprenoid quinone contents of seven strains of "Afipia felis," the type strains of "A. clevelandensis" and "A. broomeae," and reference strains of three unnamed "Afipia" genospecies were determined by reverse-phase high-performance liquid chromatography. The quinone profiles of all "Afipia" strains were essentially identical, with ubiquinone 10 as the major component. The identity of ubiquinone 10 was confirmed by mass spectrometry.
Differentiation of Acanthamoeba strains from infected corneas and the environment by using restriction endonuclease digestion of whole-cell DNA
Authors: Kilvington S , Beeching J R , White D G
Published: January 2020

Restriction endonuclease digestion of Acanthamoeba whole-cell DNA was used to study the relationship between 33 morphologically identical strains from keratitis cases (30 strains), contact lens storage containers (2 strains), and soil (1 strain). Samples digested with BglII, EcoRI, or HindIII and separated by agarose gel electrophoresis contained detectable mitochondrial DNA restriction fragment length polymorphisms (RFLPs). By comparing RFLPs, the strains could be assigned to seven multiple-strain and three single-strain groups. The largest of these contained nine strains, eight of which were isolated in keratitis cases in various locations worldwide and may indicate a group particularly associated with keratitis. Restriction endonuclease analysis of whole-cell DNA is proposed as a valuable technique for detecting mitochondrial DNA RFLPs in the differentiation of morphologically identical Acanthamoeba strains and may therefore be useful in resolving the complex taxonomy of the genus, which has hitherto been founded on subjective morphological criteria.
Application of gas-liquid chromatographic analysis of cellular fatty acids for species identification and typing of coagulase-negative staphylococci
Authors: Kotilainen P , Huovinen P , Eerola E
Published: January 2020

Gas-liquid chromatography (GLC) of bacterial cellular fatty acids was used to analyze 264 isolates of coagulase-negative staphylococci, of which 178 were Staphylococcus epidermidis. The presence and amounts of individual fatty acids were determined to generate fatty acid profiles for each of the seven coagulase-negative species tested. The fatty acid profiles were then analyzed by computerized correlation and cluster analysis to calculate mean correlation values between isolates belonging to the same or different species, as well as to establish cluster analysis dendrograms. These data ultimately allowed the clustering of individual samples into species-specific clusters. Species identification by the GLC clustering was highly consistent with species identification by biochemical assays; the results were similar in 92.4% of the cases. The GLC profile correlation analysis was further used to analyze multiple blood isolates from 60 patients in order to determine the usefulness of this methodology in establishing identity, as well as differences, between consecutive patient isolates. The correlation between those multiple S. epidermidis isolates determined to be identical by standard techniques (such as the antibiogram, biotype, and plasmid profile) was significantly (P less than 0.001) higher than that between random isolates of the same species. The correlation coefficient was greater than 97 for 40 (97.6%) of the 41 patients with multiple identical blood isolates, compared with less than 95 in all 19 (100.0%) patients with multiple nonidentical isolates. The successful use of the computerized GLC analysis in this study demonstrated its appropriate application for species identification and typing of coagulase-negative staphylococci.
Performance of cryptococcus antigen latex agglutination kits on serum and cerebrospinal fluid specimens of AIDS patients before and after pronase treatment
Authors: Hamilton J R , Noble A , Denning D W , Stevens D A
Published: January 2020

Cryptococcal antigen titers in 97 serum and 42 cerebrospinal fluid (CSF) specimens from 37 AIDS patients with culture-proven cryptococcal infection were determined with the Meridian kit (Meridian Diagnostics Inc., Cincinnati, Ohio) before and after treatment with pronase. The geometric mean titers before and after pronase treatment were 1:45 and 1:588 in serum and 1:97 and 1:79 in CSF, respectively. Only on serum (but not CSF) specimens after pronase treatment were (i) titers increased by 2 to 13 dilutions on 57% of the specimens, all of which had titers of less than or equal to 1:128 before pronase treatment, (ii) false-negative reactions on 27% of specimens before pronase treatment eliminated, all of which had titers from 1:4 to 1:4,096, (iii) prozone-like reactions (titer, less than or equal to 1:256) on 9% of the specimens before pronase treatment eliminated, and (iv) agglutination reactions on all specimens stronger and easier to interpret. Antifungal agents added to serum as well as freeze-thaw cycles did not change antigen titers in serum. After two separate tests, the same titers were obtained on 94% of 35 serum specimens that were treated with pronase and on 96% of 53 CSF specimens that were not treated with pronase. A total of 26 serum specimens and 28 CSF specimens from patients with no cryptococcal disease were negative before and after pronase treatment. The IBL kit (International Biological Labs Inc., Cranbury, N.J.) was compared with the Meridian kit on 41 serum specimens and 14 CSF specimens. Results from the two kits agreed on 54 and 68% of serum specimens and 86 and 93% of CSF specimens before and after pronase treatment, respectively. The IBL kit generally produced higher titers on specimens in disagreement and produced no prozone-like reactions. Routine pronase treatment of serum is recommended with the Meridian kit in order to eliminate false-negative and unclear agglutination reactions by producing a consistent interpretation of agglutination reactions. CSF specimens do not require pronase treatment. Titer results produced by the kits from the two different manufacturers varied considerably: the kits should not be used interchangeably for determining antigen titers in serum specimens.
Genus-specific epitope on the 60-kilodalton Legionella heat shock protein recognized by a monoclonal antibody
Authors: Steinmetz I , Rheinheimer C , Hübner I , Bitter-Suermann D
Published: January 2020

A monoclonal antibody (MAb) immunoglobulin G2a (2125) was produced against a 60-kDa Legionella heat shock protein (HSP), recognizing a unique epitope common to all species of the genus Legionella. The antibody reacted in the immunoblot with 59 Legionella species and serogroups that were tested and showed no cross-reactivity with other bacteria, including Acinetobacter spp., Bordetella spp., Pseudomonas spp., Mycobacterium spp., and Escherichia coli. Two other MAbs (2122 and 2130) reacted with the 60-kDa Legionella protein as well but showed different cross-reactivities with other gram-negative bacteria in the same molecular mass range. The genus-specific MAb 2125 as well as the cross-reacting MAbs 2122 and 2130 were shown to be reactive with the expressed protein of the cloned gene of the 60-kDa HSP of Legionella micdadei and Legionella pneumophila. These antibodies demonstrate that Legionella-specific and nonspecific epitopes are present on this protein. A sandwich enzyme-linked immunosorbent assay (ELISA) in which the genus-specific MAb is used both as a capture antibody and as a biotinylated second antibody has been established. With this test it is possible to detect Legionella whole cells, sonicated cells, and cell fractions containing the 60-kDa HSP. The main part of the 60-kDa HSP is found in the cytoplasmic fraction. The sandwich ELISA can be used to demonstrate the increased expression of the 60-kDa protein in Legionella cells following heat shock as well as marked differences in the detection of the 60-kDa HSP on whole cells of different Legionella strains. The high specificity and sensitivity of the sandwich ELISA for sonicated cells might be very useful to screen on a genus level for Legionella cells or the 60-kDa antigen in environmental isolates or body fluids of patients.
Interpretive criteria and quality control guidelines for Neisseria gonorrhoeae susceptibility test standardization for cefotetan
Authors: Jones R N , Gerlach E H , Koontz F P , Murray P R , Pfaller M A , Washington J A , Erwin M E , Knapp C C
Published: January 2020

Cefotetan was tested in a multilaboratory study to standardize susceptibility testing criteria and quality control guidelines for Neisseria gonorrhoeae. Cefotetan was most active against penicillinase-producing and penicillin-susceptible strains (MIC for 50% of strains tested, 0.5 micrograms/ml) and was least active against the chromosomally resistant isolates (MIC for 50% of strains tested, 2 micrograms/ml). The recommended 30-micrograms disk cefotetan interpretive criteria were as follows: susceptible at greater than or equal to 26 mm (less than or equal to 2 micrograms/ml), intermediate at 20 to 25 mm (4 micrograms/ml), and resistant at less than or equal to 19 mm (greater than or equal to 8 micrograms/ml). Quality control guidelines for agar dilution and disk diffusion tests were established by using numerous GC agar lots, three cefotetan 30-micrograms disk lots, two quality control organisms, and a volume of tests consistent with National Committee for Clinical Laboratory Standards M23-T guidelines.
Prospective study of the association between serum antibodies to lipopolysaccharide O antigen and the attack rate of shigellosis
Authors: Cohen D , Green M S , Block C , Slepon R , Ofek I
Published: January 2020

A means for determining immune status against shigellosis would significantly improve the design and evaluation of interventional and other epidemiologic studies. Previous case-control studies have indicated the potential role of humoral antilipopolysaccharide antibodies. To test this proposition, 190 soldiers serving in a field unit were monitored prospectively for 2.5 months for shigellosis. Blood samples were taken at the beginning of the follow-up period and tested for serological evidence of prior exposure to Shigella sonnei and Shigella flexneri. The risk for acquiring S. sonnei shigellosis was 3.7 times higher for individuals lacking homologous antibodies (P less than 0.02). The risk for acquiring S. flexneri shigellosis was 2.4 times higher for individuals lacking antibodies, although a low attack rate for S. flexneri resulted in numbers too small to achieve statistical significance. While the importance of the serum antilipopolysaccharide antibodies in protection against the disease remains unclear, these findings demonstrate that they are strong markers of acquired immunity. Serological markers should be incorporated in epidemiologic studies of shigellosis and in the design and evaluation of future trials of potential anti-Shigella vaccines.
Isolation of Chlamydia pneumoniae from the lungs of patients infected with the human immunodeficiency virus
Authors: Augenbraun M H , Roblin P M , Chirgwin K , Landman D , Hammerschlag M R
Published: January 2020

Chlamydia pneumoniae is being recognized as a common cause of respiratory tract infections. Bronchoalveolar lavage specimens from human immunodeficiency virus-infected patients were examined by culture for this pathogen. Of 50 specimens examined, 5 (10%) were positive for C. pneumoniae. Four of these (80%) were also positive for other pathogens frequently implicated as causes of respiratory disease in this patient population. C. pneumoniae may frequently inhabit the respiratory tracts of human immunodeficiency virus-infected individuals.
Rapid, on-site diagnosis of chlamydial urethritis in men by detection of antigens in urethral swabs and urine
Authors: Sellors J , Mahony J , Jang D , Pickard L , Castriciano S , Landis S , Stewart I , Seidelman W , Cunningham I , Chernesky M
Published: January 2020

First-void urine (FVU) sediments of 240 men were tested for Chlamydia trachomatis antigens by two enzyme immunoassays, TestPack Chlamydia (15 min) and Chlamydiazyme (3.5 h), and the results were compared with urethral swab culture results. The sensitivity and specificity on FVU sediment for TestPack Chlamydia were 76.2% (32 of 42 specimens) and 95.5% (189 of 198 specimens) versus 81.0% (34 of 42 specimens) and 96.5% (191 of 198 specimens) for Chlamydiazyme, respectively. Rapid, on-site detection of chlamydial antigen in male FVU would shorten the infectious period by hastening diagnosis and treatment.
Rapid culture confirmation of herpes simplex virus by a monoclonal antibody-based enzyme immunoassay
Authors: Patel H , Frenkel L D , Greenhalgh M , Howell R , Patel S
Published: January 2020

Rapid confirmation of herpes simplex virus (HSV) is essential in many clinical settings. Viral isolation in cell culture is the standard method for diagnosing HSV infection, with confirmation by specific immunological staining. The performance of the Rapid Absorbent Matrix Pad (RAMP) HSV culture confirmation test was evaluated with specimens obtained from 71 patients with suspected HSV infection and inoculated into African green monkey kidney cell lines. Forty-one culture-positive specimens were confirmed to be HSV by both the RAMP HSV test and the Bartels HSV immunoperoxidase test. Thirty immunoperoxidase-negative specimens were also negative in the RAMP HSV test. The sensitivity and specificity of the RAMP HSV test were 100%. Twelve specimens positive for cytomegalovirus, adenovirus, or enterovirus tested negative by the RAMP HSV test. Thus, the RAMP HSV test was faster than, easier to perform than, as sensitive as, and as specific as other well-documented confirmation methods.
Effect of treatment on serum antibody to Hymenolepis nana detected by enzyme-linked immunosorbent assay
Authors: Castillo R M , Grados P , Carcamo C , Miranda E , Montenegro T , Guevara A , Gilman R H
Published: January 2020

An enzyme-linked immunosorbent assay (ELISA) was developed to measure serum immunoglobulin G antibodies in 65 patients infected with Hymenolepis nana and 30 noninfected patients. Antibody was detected in 51 of 65 (sensitivity, 79%) and 5 of 30 H. nana-negative patients (specificity, 83%). Nine patients infected with H. nana were treated with praziquantel (20 to 25 mg/kg of body weight). Antibody disappeared from the sera at 90 days in six patients, five of whom had eliminated H. nana. Antibody persisted in three patients in whom H. nana infection did not clear after treatment. The H. nana ELISA had a high rate of cross-reactions with sera from patients with cysticercosis (8 of 29 [28%]) and hydatidosis (8 of 23 [35%]). The ELISA for H. nana may be useful for defining the epidemiology of H. nana infections, especially in areas free from cysticercosis and hydatidosis.
Reactivities of serotyping monoclonal antibodies with culture-adapted human rotaviruses
Authors: Ward R L , McNeal M M , Clemens J D , Sack D A , Rao M , Huda N , Green K Y , Kapikian A Z , Coulson B S , Bishop R F
Published: January 2020

Rotaviruses collected in Bangladesh during 1985 to 1986 were culture adapted and used in a comparative serotyping study with three groups of monoclonal antibodies, all of which reacted with the major neutralization protein (VP7) of serotype 1, 2, 3, or 4. The goals were to determine which monoclonal antibodies most accurately predicted the serotype and why large variations in serotyping efficiencies have occurred with these monoclonal antibodies in previous studies. The 143 rotavirus isolates used in this study belonged to 69 different electropherotypes; and 44, 23, 21, and 55 isolates were identified as serotype 1 through 4, respectively, by neutralization with serotype-specific hyperimmune antisera. Serotyping specificity by enzyme-linked immunosorbent assay with monoclonal antibodies was 100% consistent with results found by neutralization with polyclonal antisera, but large differences were observed in the sensitivities of the different monoclonal antibodies. Monoclonal antibodies 5E8 (serotype 1), 1C10 (serotype 2), 159 (serotype 3), RV3:1 (serotype 3), ST-3:1 (serotype 4), and ST-2G7 (serotype 4) reacted with all the isolates of the corresponding serotype for which there were sufficient infectious particles. Monoclonal antibody 2F1 (serotype 2) was much less sensitive and reacted with only five serotype 2 isolates, but these were among those with the highest titers. Monoclonal antibodies RV4:2 (serotype 1), KU6BG (serotype 1), RV5:3 (serotype 2), and S2-2G10 (serotype 2), on the other hand, failed to react with between one and three isolates of the corresponding serotypes which had high titers, apparently because of epitope changes in these isolates. Effects of epitope variation were, however, most apparent with monoclonal antibodies 2C9 (serotype 1) and YO-1E2 (serotype 3), which reacted with one and no isolates of the corresponding serotypes, respectively. Cross-neutralization of escape mutants indicated that the serotype 1 monoclonal antibodies 5E8, 2C9, and RV4:2 reacted with different but probably overlapping epitopes, as did serotype 2 monoclonal antibodies 2F1, 1C10, and RV5:3, finding that were consistent with the enzyme-linked immunosorbent assay data. Because of epitope variations between rotavirus strains, serotyping with several monoclonal antibodies directed at different epitopes may increase the sensitivity of the method.
Clinical evaluation of the RapID-ANA II panel for identification of anaerobic bacteria
Authors: Celig D M , Schreckenberger P C
Published: January 2020

The accuracy of the RapID-ANA II system (Innovative Diagnostic Systems, Inc., Atlanta, Ga.) was evaluated by comparing the results obtained with that system with results obtained by the methods described by the Virginia Polytechnic Institute and State University. Three hundred anaerobic bacteria were tested, including 259 clinical isolates and 41 stock strains of anaerobic microorganisms representing 16 genera and 48 species. When identifications to the genus level only were included, 96% of the anaerobic gram-negative bacilli, 94% of the Clostridium species, 83% of the anaerobic, nonsporeforming, gram-positive bacilli, and 97% of the anaerobic cocci were correctly identified. When correct identifications to the genus and species levels were compared, 86% of 152 anaerobic gram-negative bacilli, 76% of 34 Clostridium species, 81% of 41 anaerobic, nonsporeforming, gram-positive bacilli, and 97% of 73 anaerobic cocci were correctly identified. Eight isolates (3%) produced inadequate identification in which the correct identification was listed with one or two other possible choices and extra tests were required for separation. A total of 9 isolates (3%) were misidentified by the RapID-ANA II panel. Overall, the system was able to correctly identify 94% of all the isolates to the genus level and 87% of the isolates to the species level in 4 h by using aerobic incubation.
Detection of respiratory syncytial virus in nasopharyngeal secretions by shell vial technique
Authors: Smith M C , Creutz C , Huang Y T
Published: January 2020

A shell vial technique was used to recover respiratory syncytial virus (RSV) from frozen nasopharyngeal specimens previously tested by rapid diagnostic methods. With specimens determined to be positive by direct fluorescence assay (DFA), the shell vial technique was at least as sensitive as conventional tissue culture (92 versus 90%). The majority of RSV isolates were detected within 16 h postinoculation, versus an average of 4.5 days by conventional techniques. Also, the shell vial method recovered RSV from 16 of 17 specimens (94%) which had previously tested positive by enzyme immunoassay (EIA). In addition, the shell vial method detected RSV in 4 and 11% of specimens previously determined to be negative by DFA and EIA, respectively. Therefore, we recommend the use of the shell vial technique for specimens testing negative by the rapid methods of DFA or EIA.
Immune response to a major epitope of p24 during infection with human immunodeficiency virus type 1 and implications for diagnosis and prognosis
Authors: Janvier B , Baillou A , Archinard P , Mounier M , Mandrand B , Goudeau A , Barin F
Published: January 2020

A sequential inhibition enzyme-linked immunoassay (SIEIA) using a peroxidase-conjugated monoclonal antibody reacting to the sequence AAEWDRVHP of p24HIV-1 (amino acids 209 to 217 of p55) was developed in order to detect and determine the titer of antibody to this epitope in various populations of human immunodeficiency virus type 1 (HIV-1)-positive patients. There was a good correlation between SIEIA and a commercially available competition assay that uses recombinant p24 protein and polyclonal antibody to HIV-1 antigen, demonstrating the importance of the described epitope. Analysis of sera from French patients showed a decline of antibody to the AAEWDRVHP sequence associated with the progression of AIDS. No decrease was observed with serum samples from African patients. An immune response to the epitope was detected by SIEIA early in the course of seroconversion. Although our SIEIA uses a single p24 epitope, these data are in accordance with previously published studies in which antibodies to the whole p24 were analyzed. Sera reacting to p24 only (indeterminate profiles by Western blot [immunoblot]) did not bind to AAEWDRVHP. This epitope, which is conserved between HIV-1 and HIV-2/simian immunodeficiency virus, appears to be a major antigenic domain of p24. The area containing the sequence AAEWDRVHP and the corresponding monoclonal antibody may serve as a convenient alternative to whole purified p24 and polyclonal antibody in diagnostic and prognostic assays.
cDNA probes for the diagnosis of bovine torovirus (Breda virus) infection
Authors: Koopmans M , Snijder E J , Horzinek M C
Published: January 2020

A genomic cDNA library of RNA from Breda virus (BRV), a bovine torovirus, was prepared. The nucleotide sequence of the 3' end of the genome was found to be highly conserved (93% identical) between BRV and Berne virus, the torovirus prototype. Cross-hybridization experiments were performed to select Berne virus cDNA clones for use as probes in a dot hybridization assay; the objective was to detect heterologous torovirus RNA in fecal material. A rapid RNA extraction method was employed to make the test applicable for routine diagnosis. Samples from calves after experimental and natural infection with BRV were assayed to establish the sensitivity and specificity of the test and to compare the test with the enzyme-linked immunosorbent assay (ELISA) for antigen detection. For this purpose, 53 samples from seven infected calves were tested with both methods. In the ELISA, BRV was detected in six fecal samples from three inoculated calves. By use of the hybridization test, 16 samples from seven calves reacted positively. With one exception, only postinoculation samples were found positive in hybridization. No signal was seen in feces from uninoculated calves or from calves infected with rotavirus or coronavirus.
Development of natural immunity in Plasmodium falciparum malaria: study of antibody response by Western immunoblotting
Authors: Thelu J , Sheick-Zakiuddin I , Boudin C , Peyron F , Picot S , Ambroise-Thomas P
Published: January 2020

A longitudinal study was carried out in Burkina Faso to investigate the natural development of the immune response to Plasmodium falciparum malaria. Three bleedings were carried out before, during, and after the seasonal peak of transmission. Detailed antigen mapping and antibody prevalence of the 248 collected serum samples were established by immunoblotting on the basis of several epidemiological and biological parameters. An improved Western immunoblotting system was used to analyze up to 67 serum samples on each nitrocellulose sheet. This system allowed us to perform the entire study with strictly comparable conditions. Two different blood-stage antigens (exoantigens and somatic antigens) were used to analyze the distribution of different classes and subclasses of immunoglobulins according to the age of the individuals, the presence or absence of a malarial attack, the transmission period, the origin of parasite isolates, and the response to intraerythrocytic stages. Although this analysis emphasizes strong individual variations, reactions with two major antigens of 115 and 103 kDa were especially noted. These antigens induced high antibody levels and prevalences but were probably not involved in protection. The prevalence of immunoglobulin G (IgG) antibodies differed by isotype. Most of antigens stimulating IgG production were also responsible for the IgM antibody response. The role played by these antibodies in the development of natural immunity against malaria is discussed.
Outbreak of human calicivirus gastroenteritis in a day-care center in Sydney, Australia
Authors: Grohmann G , Glass R I , Gold J , James M , Edwards P , Borg T , Stine S E , Goldsmith C , Monroe S S
Published: January 2020

Between January and March 1988, an outbreak of gastroenteritis occurred among children and staff at a day-care center in Sydney, New South Wales, Australia. Over an 11-week period, 53 persons had 101 episodes of gastroenteritis; some patients had 5 separate episodes. The principal etiologic agent in the outbreak, human calicivirus (HCV), was detected by electron microscopy in 32% of fecal specimens from children and staff members with symptoms but in only 8% of asymptomatic individuals (P less than 0.01). HCV was confirmed by both an enzyme immunoassay and solid-phase immune electron microscopy. HCV infection was a particular problem in infants, who had the highest age-specific attack rates, had the greatest symptomatic/asymptomatic infection ratio, and were most likely to have a second symptomatic episode. The mode of transmission of this virus was not identified, and extensive efforts to control the 11-week outbreak had little effect. Prolonged excretion of HCV by some symptomatic patients and high rates of asymptomatic infection may have contributed to the extended duration of the outbreak. HCV may be a common cause of gastroenteritis in children that is under-recognized because of insensitive methods of detection.