bluuebunny/crossref_metadata_2025 huggingface dataset:
Titration of Newcastle disease virus and its neutralizing antibodies in microplates by a modified hemadsorption and hemadsorption inhibition method
Authors: Israel Institute for Biological Research, Ness-Ziona, Israel
Published: May 2021

Using the microtiter system, titration of Newcastle disease virus infectivity and neutralizing antibodies was carried out in chicken embryo fibroblasts grown in "U" or flat-bottomed plates. Infectivity was detected by a combined hemadsorption-hemagglutination method. Inhibition of that reaction indicated the presence of neutralizing antibodies. A 24-h microneutralization test was developed and compared to the plaque neutralization and microhemagglutination inhibition test. Reproducibility of the microneutralization test was statistically analyzed.
Antigenic relationships among influenza virua A neuraminidase (N2) antigens by immunodiffusion and postinfection neutralization tests
Authors: Dowdle W R , Laver W G , Galphin J C , Downie J C
Published: May 2021

The antigenic relationships among the neuraminidases of influenza A strains from 1957 to 1973 were examined by postinfection application of neuraminidase antisera. This procedure causes inhibition of virus spread and apparent neutralization. Neuraminidase (apparent) neutralization and neuraminidase inhibition tests with chicken antisera gave similar results. Neuraminidase inhibition tests were more discriminating than neuraminidase neutralization tests when rabbit and goat antisera were used. Antibody absorption studies revealed that the neuraminidase, like the hemagglutinin, may possess two kinds of antigenic determinants, which can give rise to "common," or "cross-reacting," and "specific" antibodies. "Specific" antibody appears to be more effective in the inhibition of enzyme activity than in the inhibition of virus spread.
Polymicrobic bacteriuria: significant association with bacteremia
Authors: Gross P A , Flower M , Barden G
Published: May 2021

Current clinical practice states that a urine culture yielding three or more isolates must be considered a contaminated specimen and discarded. The validity of this practice was tested by reviewing all patients at the West Haven Veterans Administration Hospital with positive blood cultures for 1 year to determine how many were associated with polymicrobic bacteriuria (two or more urine isolates each present at greater than 10(5) colonies/ml). During 1973 there were 18 patients who had bacteremia associated with a urinary tract infection in which the same organism with the identical antibiogram was found in both the blood and the urine of these 18 patients with monomicrobic bacteremia 11(61%) had polymicrobic bacteriuria, with a mean of an additional 1.75 urinary pathogens present in significant quantities. In these patients with polymicrobic bacteriuria, an indwelling bladder catheter was present for a mean period of 4.4 months before the episode of bacteremia. Only 5 of the 11 patients with polymicrobic bacteriuria had temporally associated urinary tract manipulation. Monomicrobic bacteriuria occurred in seven patients (39%). The mean indwelling bladder catheter time was 0.9 days, and urinary tract manipulation near the time of bacteremia occurred in all seven patients. Prospectively, nine other patients with polymicrobic bacteriuria were recultured by one of us to be certain that appropriate collection and transportation methods were used; the presence of polymicrobic bacteriuria was repeatedly demonstrated in 7(78%). This study illustrates the clinical importance of polymicrobic bacteriuria.
Rapid recognition of group B streptococci by pigment production and counterimmunoelectrophoresis
Authors: Merritt K , Treadwell T L , Jacobs N J
Published: May 2021

Streptococci from clinical isolates were studied for their ability to produce pigment in stab cultures in Columbia agar. Serological grouping of these organisms was done by counterimmunoelectrophoresis using Burroughs-Wellcome antisera. In this group of isolates, 66 of the 68 organisms grouped as B by serological testing produced pigment in the Columbia agar stab cultures. Pigment was not produced by any of the other 36 streptococci studied (11 group A, 9 group C, 4 group D, and 12 nongroupable). The use of the Columbia agar stab culture is recommended as a rapid and simple test for recognition of group B streptococci. The counterimmunoelectrophoresis test is also suggested as a convenient, rapid, and sensitive method for grouping the streptococci.
Evaluation of the API 20 c microtube system for the identification of clinically important yeasts
Authors: Roberts G D , Wang H S , Hollick G E
Published: May 2021

The API 20 C microtube system containing 20 biochemical tests for the identification of yeasts was compared with conventional tests used in the Mayo Clinic mycology laboratory. Three hundred isolates of clinically important yeasts were studied, and agreement of the carbohydrate fermentation and assimilation tests between the systems was good. The API 20 C represents a useful, commercially available screening method for the identification of yeasts; however, it is not a complete system and must be used in conjunction with microscopic morphological features and, when appropriate, with other biochemical tests.
Diagnosis of herpes simplex virus infection by immunofluorescence
Authors: Taber L H , Brasier F , Couch R B , Greenberg S B , Jones D , Knight V
Published: May 2021

The utility of the indirect immunofluorescent antibody (IFA) technique for diagnosis of herpes simplex virus (HSV) infection was examined by testing specimens for this agent from 31 patients with encephalitis or meningitis, 17 with conjunctivitis, 19 with genital disease, and 1 with genital disease and meningitis. Brain biopsy tissue from four patients with encephalitis was positive by IFA and virus culture for HSV. Leukocytes in cerebrospinal fluid from these four patients and one with HSV meningitis were also positive by IFA, but virus isolation attempts on the fluid were all negative. Conjunctival scrapings from two patients with conjunctivitis were positive for HSV by both IFA and virus culture. Eleven of 12 culture-positive lesions of herpes progenitalis were positive by IFA, and 1 dark field-positive syphilitic chancre was also positive for HSV by both IFA and culture. Evidence for specificity of the results was provided by internal controls in each test and negative results from patients with other diagnoses. Thus, the IFA technique constituted a rapid, sensitive, and specific diagnostic method for the diagnosis of HSV infections.
Rapid fermentation testing of anaerobic bacteria
Authors: Schreckenberger P C , Blazevic D J
Published: May 2021

Rapid tests for glucose, maltose, lactose, sucrose, and starch fermentation were performed on 112 strains of anaerobic bacteria. The tests were incubated under aerobic conditions, and results were read within 4 h. An overall correlation of 89% was achieved between the rapid tests and the Virginia Polytechnic Institute method.
Comparison of Chlamydia subgroup A detection from clinical specimens after 40 and 64 hours of incubation in 5-iodo-2-deoxyuridine-treated McCoy's cells
Authors: Jonhson J E , Smith T F
Published: May 2021

The time course of formation of inclusion bodies produced by Chlamydia in 5-iodo-2-deoxyuridine (IUdR)-treated McCoy's cells was studied with the use of a known isolate of Chlamydia trachomatis D/UW-184/Ur and 47 frozen clinical urethral specimens previously shown to be either positive or negative for chlamydial inclusions after 3 days of incubation. Subsequent examination of 369 clinical specimens from the genitourinary tract over a 6-month period revealed 47 (13%) Chlamydia-positive cultures, all of which demonstrated inclusion bodies by iodine staining at 40 and 64 h postinoculation. Another 146 similar detected by iodine staining from 22 (15%). This study indicates that, although Chlamydia subgroup A inclusions are larger at 64 h, they can be readily detected from clinical specimens in IUdR-treated McCoy's cells at 40 h postinfection.
Halophilic Vibrio species isolated from blood cultures
Authors: Hollis D G , Weaver R E , Baker C N , Thornsberry C
Published: May 2021

The Special Bacteriology Section of the Center for Disease Control has received 38 cultures of a halophilic bacterium which apparently unnamed. On the basis of the minimal characteristics of Vibrio species proposed by Hugh and Sakazaki, this bacterium belongs to the genus Vibrio. The unnamed species can be differentiated from Vibro parahaemolyticus by a lower tolerance for sodium chloride (NaC1) and the fermentation of lactose. The failure to ferment sucrose is an additional characteristic which differentiates these organisms from V. alginolyticus. Of 33 unnamed species strains tested, all were sensitive to penicillin, ampicillin, carbenicillin, cephalothin, chlorapmphenicol, gentamicin, tetracycline, rifampin, nitrofurantoin, and sulfisoxazole by agar diffusion and agar dilution tests. The sources of isolation of the cultures of the unnamed species suggest that it is a clinically important organism. Twenty strains were isolated remaining cultures were isolated from localized infections of the extremities. In contrast, only 2 of 60 cultures of V. parahaemolyticus and V. alginolyticus received in our laboratory as human isolates from extra-intestinal sources were isolated from blood.
Evaluation of the Beckman Antistreptolysin O and Antideoxyribonuclease B (ASO/ADB) Test Kit
Authors: Klein George C.
Published: May 2021

The Beckman antistreptolysin O kit agreed within one-dilution increment for 70% of the specimens tested. The antideoxyribonuclease B kit agreed within onedilution increment for 96% of the specimens tested.
Persistence of antibody to hepatitis B surface antigen
Authors: Irwin G R , Allen A M , Segal H E , Willhight M , Cannon H , Top F H
Published: May 2021

Sera from military personnel found to have antibodies to hepatitis B surface antigen (anti-HBS) in an epidemiological study of a hepatitis B outbreak were tested for persistence of that antibody 1 year later. Initially, 64% of the anti-HBS-positive sera reacted in passive hemagglutination tests with erythrocytes coated with hepatitis B surface antigen of both ayw and adw subtypes; the remaining sera reacted only with adw-coated erythrocytes (19%) or ayw-coated erythrocytes (17%). After 1 year, anti-HBS was detectable by passive hemagglutination tests in 87% of individuals with initial antibody to both subtypes but in only 41% and 16% (P less than 0.001) of those initially reacting only to adw- or ayw-coated erythrocytes, respectively. Seropositivity for anti-HBS correlated best with history of contact with jaundiced people (20.3%) and duty in Asia.
Hepatitis B infection in health care personnel of an institution for mentally handicapped children and adults
Authors: Tiku M L , Beutner K R , Carmody P , Sultz H A , Kaul B L , Ogra P L
Published: May 2021

The health care personnel (HCP) of an institution for the mentally handicapped were serially tested for the presence of hepatitis B surface antigen (HBSAg) and antibody over a period of 1.5 years. HBSAg was present in 1.8% and anti-HBS in 20.8% of HCP. The prevalence of seropositive HCP appeared to be related to the age and the prevalence of seropositive residents cared for by the HCP. The occurrence of seropositivity was higher in the HCP who cared for children under 15 years of age, who demonstrated a high prevalence of HBSAg or anti-HBS. Although the prevalence of HBSAg-positive subjects was 4- to 8-fold lower in HCP than in residents, the degree of seroconversion in susceptible seronegative HCP and residents was strikingly similar. These observations suggest that HCP working in a closed institutional setting are at considerable risk of contacting hepatitis B infection.
Direct Measurement of Microplates and Its Application to Enzyme-Linked Immunosorbent Assay
Authors: Ruitenberg E. J. , Brosi B. J. M. , Steerenberg P. A.
Published: May 2021

A commercially available system for enzyme analysis was adapted for high-speed reading of microplates in which the enzyme-linked immunosorbent assay was performed.
Differential quantitation of surface and subsurface bacteria of normal skin by the combined use of the cotton swab and the scrub methods
Authors: Evans C A , Stevens R J
Published: May 2021

By testing adjacent sites on the hypothenar eminence of the palm, enriched with bacteria by massaging the forehead, we found that the numbers of bacteria recovered from the skin surface by a wet cotton swab in 30 s were not significantly different from the numbers obtained by a brisk scrubbing with a blunted Teflon policeman for 120 s. This was true of aerobes (gram-positive cocci) and anaerobes (propionibacteria). If the same site on the palm was swabbed two times for 15 s each time, 67 to 94% of the total recovered bacteria were obtained on the first swab. Differential localization of bacteria into surface and subsurface populations was accomplished by first swabbing a test skin site to assay the surface flora and then scrubbing the same site to test for subsurface organisms. On the palm the swab yielded more aerobes and anaerobes than did the subsequent scrub. On the forehead the scrub yielded three to eight times as many anaerobes as the preceding swab. In some tests gram-positive cocci were distributed on the forehead like propionibacteria (large excess in scrub specimen); in other tests their numbers were similar in the swab and scrub specimens or there was a large excess in the swab specimen. These results indicate that there was no substantial subsurface flora on the palm. On the forehead propionibacteria were predominantly in deeper locations in all tests; gram-positive cocci were variable: in some test sites they were largely at the surface, whereas at other sites a predominance of cocci was in subsurface locations.
Preparation of rabies fluorescein isothiocyanate-labeled immune globulin from mouse hyperimmune ascitic fluids
Authors: Tzianabos T , Hebert G A , White L A
Published: May 2021

Immunization conditions for the production of mouse immune ascitic fluids to be used for the preparation of rabies fluorescent antibody (FA) conjugate are presented. The use of optimal concentrations of ammonium sulfate for precipitation of gamma globulin resulted in a fraction consisting of 75% gamma globulin and 25% alpha-beta globulins with no detectable albumin. Dialysis labeling of the globulin fration with fluorescein isothiocyanate produced a specific rabies FA conjugate with negligible nonspecific background staining. This procedure represents a simple means of producing rabies FA conjugate.
Differential agar medium (A7) for identification of Ureaplasma urealyticum (human T mycoplasmas) in primary cultures of clinical material
Authors: Shepard M C , Lunceford C D
Published: May 2021

A differential agar medium for the identification of Ureaplasma urealyticum in primary cultures of clinical specimens is described. The differential medium (no. A7) is specific for the identification of U. urealyticum and other members of the genus Ureaplasma. Large-colony, classical Mycoplasma and Acholeplasma species and Proteus L colonies are unreactive on this differential medium. The medium incorporates the biochemical principle of the direct spot test for urease in colonies of Ureaplasma and contains added urea and a sensitive indicator of ammonia, manganous sulfate. Ureaplasma colonies on this medium are identified as dark golden-brown or rich deep-brown colonies, in sharp contrast to the light background of the medium, when viewed by direct transmitted illumination under the low power of the microscope.
A Simplified Leifson Flagella Stain
Authors: Clark W. A.
Published: May 2021

Flagella of bacteria taken directly from 24- and 48-h blood agar plates can be stained by using a simple, reliable procedure.
Detection of virus-specific immunoglobulins using a doubly labeled fluorescein-125I antibody
Authors: Parkinson A J , Kalmakoff J
Published: May 2021

Commercially prepared fluorescein-labeled antihuman antibodies were labed with 125I and used to compre specific herpes simplex virus antibody titers as determined by indirect fluorescent antibody and radioimmunoassay techniques. Total virus-specific immunoglobulin and virus-specific immunoglobulin G titers did not vary by more than one twofold dilution when compared by the two methods.
Clinically Applicable Multiplex PCR for Four Middle Ear Pathogens
Authors: Hendolin Panu H. , Paulin Lars , Ylikoski Jukka
Published: May 2021

The multiplex PCR method for the detection of
Alloiococcus otitidis
,
Haemophilus influenzae
,
Moraxella catarrhalis
, and
Streptococcus pneumoniae
(P. H. Hendolin, A. Markkanen, J. Ylikoski, and J. J. Wahlfors, J. Clin. Microbiol. 35:2854–2858, 1997) in middle ear effusions (MEEs) was modified to be better suited for clinical use. To detect false-negative results, an internal amplification was added to the reaction, and to prevent carryover contamination, the dUTP–uracil-N-glycosidase system was incorporated into the procedure. Labor was minimized by using the heat-activatable AmpliTaq Gold polymerase in order to circumvent manual hot start and by detecting the amplification products on an automated sequencer. The performance of the improved protocol was verified with MEEs from patients with otitis media with effusion. In addition, a ligase detection reaction (LDR) was developed for confirmation of the PCR products. The modifications increased the reliability of the protocol and the hands-off time significantly. However, when two DNA extraction protocols were compared, gram-negative bacteria were detected more often in phenol-treated MEEs (94 versus 46%;
P
< 0.001), and gram-positive bacteria were detected more often in MEEs dissolved in sodium dodecyl sulfate-NaOH-chaotropic salt (83 versus 27%;
P
< 0.001). The LDR was found to be 100% specific. In all, the results demonstrate the feasibility of the rapid (7-h) multiplex PCR method for routine laboratory use.
Molecular Epidemiology of Genital
Chlamydia trachomatis
Infection in High-Risk Women in Senegal, West Africa
Authors: Sturm-Ramirez Katharine , Brumblay Hunter , Diop Khady , Guèye-Ndiaye Aissatou , Sankalé Jean-Louis , Thior Ibou , N'Doye Ibrahima , Hsieh Chung-Cheng , Mboup Souleymane , Kanki Phyllis J.
Published: May 2021

The prevalence and heterogeneity of
Chlamydia trachomatis
infections in a cohort of female sex workers in Dakar (Senegal) were determined by using endocervical-swab-based PCR DNA amplification assays. The overall prevalence of cervical chlamydial infection was 28.5% (206 of 722), and most of these infections were asymptomatic. An increased number of sexual partners was significantly associated with infection (adjusted odds ratio [AOR] = 1.37; 95% confidence interval [CI] = 1.06 to 1.77), while the presence of a yeast infection was negatively associated with chlamydial infection (AOR = 0.28; 95% CI = 0.10 to 0.83). Six different
C. trachomatis
genotypes were identified based on phylogenetic analysis of the
omp1
gene sequences. Interestingly, genotype E predominated (47.6%) and was not associated with visible signs of cervical inflammation compared to non-E genotypes (
P
< 0.05). Overall, the high rate of asymptomatic
C. trachomatis
infection by genotype E may suggest genotype-specific properties that confer a transmission advantage in this high risk population.
Performance of Immunoblotting in Diagnosis of Visceral Leishmaniasis in Human Immunodeficiency Virus-
Leishmania
sp.-Coinfected Patients
Authors: Santos-Gomes G. , Gomes-Pereira S. , Campino L. , Araújo M. De Almeida , Abranches P.
Published: May 2021

This study evaluated the performance of immunoblotting with
Leishmania infantum
soluble antigens for the diagnosis of visceral leishmaniasis in human immunodeficiency virus (HIV)-infected and immunocompetent patients and assessed the humoral responses of patients coinfected with HIV and
Leishmania
. In this work, the results of the immunoblot analysis were compared to those of parasitological examination (Giemsa-stained smears and/or parasite isolation in Novy, Nicolle, and MacNeal medium from bone marrow) and indirect immunofluorescence and counterimmunoelectrophoresis techniques. Patients were considered to be infected if one or more of the comparison techniques gave a positive result. Immunoblotting was considered to be positive if at least one band was present. For 198 HIV-positive patients with a clinical suspicion of visceral leishmaniasis, immunoblot analysis had a sensitivity of 70.6%, a specificity of 73.2%, and an accuracy of 72.7%. For a separate group of 40 immunocompetent patients not infected with
Leishmania
, the immunoblot analysis was negative for all patients (100% specificity), and for a third group of 32 immunocompetent patients with confirmed visceral leishmaniasis, the immunoblot analysis was positive for all patients (100% sensitivity). Sera of coinfected patients recognized few bands and recognized bands at lower intensities compared with sera from immunocompetent patients. The most frequently detected band was 63 to 66 kDa (55.9%), with the difference being statistically significant compared to frequency of detection of the other bands. This study confirms that the humoral response in patients coinfected with HIV and
Leishmania
is much lower than that in immunocompetent patients and that the immunoblot method is a sensitive, noninvasive, and specific serological technique for the diagnosis of visceral leishmaniasis in immunocompromised patients.
Nested PCR for Rapid Detection of Mumps Virus in Cerebrospinal Fluid from Patients with Neurological Diseases
Authors: Poggio Gustavo Palacios , Rodriguez Claudia , Cisterna Daniel , Freire María Cecilia , Cello Jerónimo
Published: May 2021

In this study, we have developed a reverse transcription (RT)-nested polymerase chain reaction (n-PCR) for the detection of mumps virus RNA in cerebrospinal fluid (CSF) from patients with neurological infections. A specific 112-bp fragment was amplified by this method with primers from the nucleoprotein of the mumps virus genome. The mumps virus RT–n-PCR was capable of detecting 0.001 PFU/ml and 0.005 50% tissue culture infective dose/ml. This method was found to be specific, since no PCR product was detected in each of the CSF samples from patients with proven non-mumps virus-related meningitis or encephalitis. Mumps virus RNA was detected in all 18 CSF samples confirmed by culture to be infected with mumps virus. Positive PCR results were obtained for the CSF of 26 of 28 patients that were positive for signs of mumps virus infection (i.e., cultivable virus from urine or oropharyngeal samples or positivity for anti-mumps virus immunoglobulin M) but without cultivable virus in their CSF. Overall, mumps virus RNA was detected in CSF of 96% of the patients with a clinical diagnosis of viral central nervous system (CNS) disease and confirmed mumps virus infection, while mumps virus was isolated in CSF of only 39% of the patients. Furthermore, in a retrospective study, we were able to detect mumps virus RNA in 25 of 55 (46%) CSF samples from patients with a clinical diagnosis of viral CNS disease and negative laboratory evidence of viral infection including mumps virus infection. The 25 patients represent 12% of the 236 patients who had a clinical diagnosis of viral CNS infections and whose CSF was examined at our laboratory for a 2-year period. The findings confirm the importance of mumps virus as a causative agent of CNS infections in countries with low vaccine coverage rates. In summary, our study demonstrates the usefulness of the mumps virus RT–n-PCR for the diagnosis of mumps virus CNS disease and suggests that this assay may soon become the “gold standard” test for the diagnosis of mumps virus CNS infection.
Recovery and Analysis of Human Immunodeficiency Virus Type 1 (HIV) RNA Sequences from Plasma Samples with Low HIV RNA Levels
Authors: Niubò Jordi , Li Wuyi , Henry Keith , Erice Alejo
Published: May 2021

Amplification of human immunodeficiency virus type 1 (HIV) reverse transcriptase (RT) and protease (PT) sequences from plasma is difficult when HIV RNA levels are low, and it usually cannot be accomplished in samples with <1,000 HIV RNA copies/ml. Because the RNA extraction step is critical for the success of subsequent amplifications and sequence analyses, two RNA extraction methods were compared to study plasma samples with low HIV RNA levels. Forty-four plasma samples containing <500 HIV RNA copies/ml in a branched-DNA (bDNA) assay (Quantiplex HIV RNA assay version 2.0 [Chiron Corp., Emeryville, Calif.]) were studied. RNA was extracted by using two commercial kits (QIAamp Viral RNA kit [Qiagen, Hilden, Germany] and NucliSens kit [Organon Teknika, Boxtel, The Netherlands]). Fragments (1,144 bp) encompassing HIV PT and RT sequences were amplified by nested PCRs. Amplified products were sequenced by using a commercial kit (Applied Biosystems). HIV RNA was recovered from a total of 21 plasma samples, including 20 samples after extraction by the NucliSens method, and 8 samples after extraction by the QIAamp method (
P
< 0.05). Mean HIV RNA levels in these samples, measured by an ultrasensitive bDNA assay (Quantiplex HIV RNA assay version 3.0; Chiron Corp., Emeryville, Calif.), were 848 copies/ml (median, 666; range, 154 to 2,606 copies/ml). Analysis of RT and PT sequences in five samples demonstrated an average of 3.8 and 2.4 resistance mutations in these regions, respectively. The NucliSens RNA extraction kit is a valuable method for obtaining HIV RNA for genotypic studies from plasma fractions of individuals with low HIV RNA levels.
Direct Amplification of rRNA Genes in Diagnosis of Bacterial Infections
Authors: Rantakokko-Jalava Kaisu , Nikkari Simo , Jalava Jari , Eerola Erkki , Skurnik Mikael , Meurman Olli , Ruuskanen Olli , Alanen Anna , Kotilainen Esa , Toivanen Paavo , Kotilainen Pirkko
Published: May 2021

A broad-range bacterial PCR targeting rRNA genes (rDNAs) was used to directly analyze 536 clinical samples obtained from 459 hospitalized patients during a 4-year study period. The molecular diagnosis based on DNA sequencing of the PCR product was compared to that obtained by bacterial culture. The bacteriological diagnosis was concordant for 447 (83%) specimens. Broad-range rDNA PCR was the only method that yielded an etiologic diagnosis for 11 (2.4%) of 459 patients. Compared to culture and clinical assessment, the sensitivity of the PCR method combined with sequencing was 74.2%, and the specificity was between 98.7 and 99.6%. At present, the described molecular approach proved superior to bacterial culture in two clinical situations: infections caused by bacteria with unusual growth requirements and specimens taken during antimicrobial treatment of the patient.
Antifungal Susceptibility Testing of Dermatophytes: Establishing a Medium for Inducing Conidial Growth and Evaluation of Susceptibility of Clinical Isolates
Authors: Jessup C. J. , Warner J. , Isham N. , Hasan I. , Ghannoum M. A.
Published: May 2021

A standardized reference method for dermatophyte in vitro susceptibility testing is lacking. In a previous study, Norris et al. (H. A. Norris, B. E. Elewski, and M. A. Ghannoum, J. Am. Acad. Dermatol. 40(6, part 2):S9–S13) established the optimal medium and other growth variables. However, the earlier study did not address two issues: (i) selection of an optimal medium for conidial formation by dermatophytes and (ii) validation of the method with a large number of dermatophytes. The present study addresses these two points. To select which agar medium best supported conidial growth, representative isolates of dermatophytes were grown on different agars. Preliminary experiments showed that only oatmeal cereal agar supported the production of conidia by
Trichophyton rubrum
. We tested the abilities of 251
T. rubrum
isolates to form conidia using three different cereal agars and potato dextrose agar. Overall, oatmeal cereal and rice agar media were comparable in their abilities to support
T. rubrum
conidial growth. Next, we used the oatmeal cereal agar for conidial formation along with the optimal conditions for dermatophyte susceptibility testing proposed by Norris et al. and determined the antifungal susceptibilities of 217 dermatophytes to fluconazole, griseofulvin, itraconazole, and terbinafine. Relative to the other agents tested, terbinafine possessed the highest antifungal activity against all of the dermatophytes. The mean ± standard error of the mean MICs of fluconazole, itraconazole, terbinafine, and griseofulvin were 2.07 ± 0.29, 0.13 ± 0.01, 0.002 ± 0.0003, and 0.71 ± 0.05 μg/ml, respectively. This study is the first step in the identification of optimal conditions that could be used for the standardization of the antifungal susceptibility testing method for dermatophytes. Inter- and intralaboratory agreement as well as clinical correlations need to be established.
Identification and Characterization of Immunoglobulin G in Blood as a Major Inhibitor of Diagnostic PCR
Authors: Al-Soud Waleed Abu , Jönsson Leif J. , Rådström Peter
Published: May 2021

A major inhibitor of diagnostic PCR in human plasma was identified and the mechanism of inhibition was characterized. Human blood was divided by centrifugation into buffy coat, plasma, platelets, and erythrocytes. All these blood fractions were found to be highly inhibitory to a standardized PCR mixture containing the thermostable DNA polymerase Ampli
Taq
Gold. PCR inhibitors in human plasma were purified by chromatographic procedures and were characterized by a process of elimination, so that the PCR-inhibitory effects of plasma fractions were tested after each purification step. The major inhibitor in human plasma, as determined by size-exclusion chromatography, anion-exchange chromatography, and chromatofocusing, was found to be immunoglobulin G (IgG) on the basis of N-terminal amino acid sequencing and electrophoretic analysis of the purified polypeptide. When different concentrations of purified plasma IgG (PIgG) were added to PCR mixtures containing 11 different thermostable DNA polymerases and 1 ng of
Listeria monocytogenes
DNA as template DNA, the only polymerase that resisted inhibition was
rTth
. The inhibitory effect was reduced when PIgG was heated at 95°C before it was added to PCR or after the addition of excess nontarget DNA to the PCR mixture. However, heating of PIgG together with target DNA at 95°C was found to block the amplification. Inhibition by PIgG may be due to an interaction with single-stranded DNA, which makes the target DNA unavailable for 10 of the DNA polymerases tested. The results show the danger of using boiling as a method of sample pretreatment or using a hot start prior to PCR. The effect of plasma PCR inhibition could be removed by mixing plasma with DNA-agarose beads prior to amplification, while plasma PCR inhibitors were found to bind to the DNA-agarose beads.
Pulmonary Infection Caused by
Gymnascella hyalinospora
in a Patient with Acute Myelogenous Leukemia
Authors: Iwen Peter C. , Sigler Lynne , Tarantolo Stefano , Sutton Deanna A. , Rinaldi Michael G. , Lackner Rudy P. , McCarthy Dora I. , Hinrichs Steven H.
Published: May 2021

We report the first case of invasive pulmonary infection caused by the thermotolerant ascomycetous fungus
Gymnascella hyalinospora
in a 43-year-old female from the rural midwestern United States. The patient was diagnosed with acute myelogenous leukemia and treated with induction chemotherapy. She was discharged in stable condition with an absolute neutrophil count of 100 cells per μl. Four days after discharge, she presented to the Cancer Clinic with fever and pancytopenia. A solitary pulmonary nodule was found in the right middle lobe which was resected by video-assisted thoracoscopy (VATHS). Histopathological examination revealed septate branching hyphae, suggesting a diagnosis of invasive aspergillosis; however, occasional yeast-like cells were also present. The culture grew a mold that appeared dull white with a slight brownish tint that failed to sporulate on standard media. The mold was found to be positive by the AccuProbe
Blastomyces dermatitidis
Culture ID Test (Gen-Probe Inc., San Diego, Calif.), but this result appeared to be incompatible with the morphology of the structures in tissue. The patient was removed from consideration for stem cell transplant and was treated for 6 weeks with amphotericin B (AmB), followed by itraconazole (Itr). A VATHS with biopsy performed 6 months later showed no evidence of mold infection. In vitro, the isolate appeared to be susceptible to AmB and resistant to fluconazole and 5-fluorocytosine. Results for Itr could not be obtained for the case isolate due to its failure to grow in polyethylene glycol used to solubilize the drug; however, MICs for a second isolate appeared to be elevated. The case isolate was subsequently identified as
G. hyalinospora
based on its formation of oblate, smooth-walled ascospores within yellow or yellow-green tufts of aerial hyphae on sporulation media. Repeat testing with the
Blastomyces
probe demonstrated false-positive results with the case isolate and a reference isolate of
G. hyalinospora
. This case demonstrates that both histopathologic and cultural features should be considered for the proper interpretation of this molecular test and extends the list of fungi recognized as a cause of human mycosis in immunocompromised patients.
Polyomaviruria in Renal Transplant Patients Is Not Correlated to the Cold Ischemia Period or to Rejection Episodes
Authors: Priftakis P. , Bogdanovic G. , Tyden G. , Dalianis T.
Published: May 2021

Polyomaviruria was observed in one-third of all renal transplant patients, irrespective of whether their renal grafts came from a living or cadaver donor, and was not correlated to graft rejection episodes. This suggests that the renal graft ischemia period is not the major cause of polyomavirus reactivation and that reactivation of polyomavirus is not a dominant cause of graft rejection.
Fungemia Due to
Fusarium sacchari
in an Immunosuppressed Patient
Authors: Guarro Josep , Nucci Marcio , Akiti Tiyomi , Gené Josepa , Barreiro M. Da Gloria C. , Gonçalves Renato T.
Published: May 2021

The fungus
Fusarium sacchari
was isolated repeatedly from the blood of an immunosuppressed host. The infection was treated successfully with a small dose of amphotericin B. The strain was resistant to this antifungal in vitro. MICs and minimum fungicidal concentrations of six antifungals for the clinical isolate are provided. To our knowledge, this is the first report involving this fungus in a case of fungemia.
2-Hour Cytomegalovirus pp65 Antigenemia Assay for Rapid Quantitation of Cytomegalovirus in Blood Samples
Authors: Landry Marie L. , Ferguson David
Published: May 2021

Of 109 blood samples tested for cytomegalovirus (CMV) antigenemia, 18 (16.5%) were positive. CMV Brite detected 13 and CMV Brite Turbo detected 16 of the 18 positives. There was no significant difference in the number of positive cells detected per sample. The seven discrepant samples contained a median of only one positive cell.
CagA Antibodies in Japanese Children with Nodular Gastritis or Peptic Ulcer Disease
Authors: Kato Seiichi , Sugiyama Toshiro , Kudo Mineo , Ohnuma Kenji , Ozawa Kyoko , Iinuma Kazuie , Asaka Masahiro , Blaser Martin J.
Published: May 2021

cagA
+
Helicobacter pylori
strains have been linked to more severe gastric inflammation, peptic ulcer disease, and gastric cancer in adults, but there have been few studies of
cagA
in children. We examined the relationship between
H. pylori cagA
status and clinical status in Japanese children. Forty
H. pylori
-positive children were studied: 15 with nodular gastritis, 5 with gastric ulcers, and 20 with duodenal ulcers.
H. pylori
status was confirmed by biopsy-based tests and serum anti-
H. pylori
immunoglobulin G (IgG) antibody. As controls, 77 asymptomatic children with sera positive for anti-
H. pylori
IgG were enrolled. Levels of IgG antibodies to CagA in serum were measured by an antigen-specific enzyme-linked immunosorbent assay. In 16 patients with successful
H. pylori
eradication, posttreatment levels of CagA and
H. pylori
IgG antibodies also were studied. The CagA antibody seropositivities of asymptomatic controls (81.8%) and patients with nodular gastritis, gastric ulcers, and duodenal ulcers (80.0 to 95.0%) were not significantly different. Compared with pretreatment levels of CagA antibodies, posttreatment levels decreased progressively and significantly. We conclude that, as in Japanese adults, a high prevalence of
cagA
+
H. pylori
strains was found in Japanese children, and that there was no association with nodular gastritis or peptic ulcer disease. In the assessment of eradicative therapies, monitoring of serum anti-CagA antibodies does not appear to offer any direct benefit over monitoring of anti-
H. pylori
antibodies.
Characterization of
Escherichia coli
Strains from Cases of Childhood Diarrhea in Provincial Southwestern Nigeria
Authors: Okeke Iruka N. , Lamikanra Adebayo , Steinrück Hartmut , Kaper James B.
Published: May 2021

In a study carried out in small-town and rural primary health care centers in southwestern Nigeria, 330
Escherichia coli
strains isolated from 187 children with diarrhea and 144 apparently healthy controls were examined for virulence traits. Based on the results of colony blot hybridization, strains were categorized as enteropathogenic
E. coli
(1.8%), enterotoxigenic
E. coli
(2.4%), enteroinvasive
E. coli
(1.2%), enterohemorrhagic
E. coli
(0.6%), enteroaggregative
E. coli
(10.3%), diffusely adherent
E. coli
(7.9%), cell-detaching
E. coli
(6.9%), and cytolethal distending toxin-producing
E. coli
(0.9%).
E. coli
strains that hybridized with a Shiga toxin gene probe but lacked other characteristics usually present in enterohemorrhagic
E. coli
constituted 8.4% of the isolates. Ninety-seven
E. coli
isolates adhered to HEp-2 cells in an aggregative fashion but did not hybridize with any of the probes employed in the study. Overall the pathotypes, apart from cytolethal distending toxin-producing
E. coli
, were recovered both from children with diarrhea and from children without diarrhea, though to a lower extent from the healthy children. All diarrheagenic
E. coli
strains were associated with diarrhea (
P
< 0.02). Heat-stable-enterotoxin-producing enterotoxigenic
E. coli
showed significant association with diarrhea (
P
< 0.02), as did strains that demonstrated aggregative adherence to HEp-2 cells (
P
< 0.04), but not those that hybridized with the CVD432 enteroaggregative probe.
Heterogeneity of
Actinobacillus actinomycetemcomitans
Strains in Various Human Infections and Relationships between Serotype, Genotype, and Antimicrobial Susceptibility
Authors: Paju Susanna , Carlson Petteri , Jousimies-Somer Hannele , Asikainen Sirkka
Published: May 2021

Actinobacillus actinomycetemcomitans
, an oral pathogen, only occasionally causes nonoral infections. In this study 52
A. actinomycetemcomitans
strains from 51 subjects with nonoral infections were serotyped and genotyped by arbitrarily primed PCR (AP-PCR) to determine whether a certain clone(s) is specifically associated with nonoral infections or particular in vitro antimicrobial susceptibility patterns. The promoter structure of leukotoxin genes was additionally investigated to find the deletion characteristic of highly leukotoxic
A. actinomycetemcomitans
strains. The nonoral
A. actinomycetemcomitans
strains included all five known serotypes and nonserotypeable strains, the most common serotypes being b (40%) and c (31%). AP-PCR distinguished 10 different genotypes.
A. actinomycetemcomitans
serotype b strains were more frequently found in blood samples of patients with bacteremia or endocarditis than in patients with focal infections. One AP-PCR genotype was significantly more frequently found among strains originating in focal infections than in blood samples. Resistance to benzylpenicillin was significantly more frequent among
A. actinomycetemcomitans
serotype b strains than among strains of other serotypes. No differences in the leukotoxin gene promoter region or benzylpenicillin resistance between nonoral and oral
A. actinomycetemcomitans
strains were observed. Nonoral
A. actinomycetemcomitans
strains showed great similarity to the oral strains, confirming that the oral cavity is the likely source of nonoral
A. actinomycetemcomitans
infections. The predominance of serotype b strains in endocarditis and bacteremia supports the hypothesis of a relationship between certain
A. actinomycetemcomitans
clones and some nonoral infections. The mechanisms behind the exceptionally high rate of occurrence of benzylpenicillin resistance among
A. actinomycetemcomitans
serotype b strains are to be elucidated in further studies.
Relationship of Incremental Specimen Volumes and Enhanced Detection of Human Immunodeficiency Virus Type 1 RNA with Nucleic Acid Amplification Technology
Authors: Witt Donald J. , Kemper M. , Stead Andrew , Ginocchio Christine C. , Caliendo Angela M.
Published: May 2021

The relationship between specimen input volume and the frequency of reported human immunodeficiency virus type 1 (HIV-1) RNA copy numbers by nucleic acid amplification technology (the NASBA HIV-1 RNA QT system) was investigated. Results obtained with both clinical specimens and dilution panels indicated that both the absolute number of reported results and the reported HIV-1 RNA copy number were directly proportional to the specimen input volumes evaluated (0.1, 0.5, and 1.0 ml). Conversion of the reported HIV-1 RNA copy numbers to a constant 1.0-ml volume indicated that the numerical relationship among the specimen input volumes and the HIV-1 RNA copy numbers was multiplicative. The HIV-1 RNA copy numbers reported for the 0.5-ml input volume were approximately 5-fold increased over those reported for the 0.1-ml input volume, and those reported for the 1.0-ml input volume were 10-fold increased over those reported for the 0.1-ml input volume. For the specimen input volumes investigated, a common linear range of 264 to 5,400,000 HIV-1 RNA copies was observed. The use of increased specimen input volumes did not result in a loss of assay specificity, as the results reported for specimens from 50 seronegative blood donors were negative at all three specimen input volumes. In conclusion, an increase in the input volume of specimens analyzed by nucleic acid amplification technology can be useful for the enhanced detection of HIV-1 RNA.
Identification of
Mycoplasma fermentans
in Synovial Fluid Samples from Arthritis Patients with Inflammatory Disease
Authors: Johnson Sheena , Sidebottom David , Bruckner Felix , Collins David
Published: May 2021

Since 1970
Mycoplasma fermentans
has been suspected of being associated with rheumatoid arthritis. However, this association has been difficult to prove, and this has been our goal. The distribution of
M. fermentans
was studied in the synovial fluid of patients suffering from different arthritides. Samples of synovial fluid were taken from patients with well-defined disease and a clear diagnosis. After removal of the inflammatory cells and hyaluran, they were treated with proteinase K and tested by a single or fully nested PCR with primers directed against part of the two 16S rRNA genes of
M. fermentans
. The product was sequenced automatically, by using an ALF Express automatic sequencer, to confirm the mycoplasma species and to identify the strain since the two genes were usually found to be polymorphic. This was also true of the type strain, strain PG18.
M. fermentans
was detected in 23 of 26 (88%) rheumatoid arthritis patients, and four different strains were found. It was also found in 7 of 8 (88%) of the nonrheumatoid inflammatory arthritis patient group, which consisted of one patient with reactive arthritis, one patient with pauciarticular juvenile chronic arthritis, two patients with gout, two patients with ankylosing spondylitis, and two patients with psoriatic arthritis, only one of whom was infected with
M. fermentans
. It was not detected in any of the 10 osteoarthritis patients.
M. fermentans
was therefore found to be a variable and very common organism in arthritic patients with inflammatory joint exudates and may well prove to be important in the etiology of the diseases.
Facial subcutaneous emphysema in a patient with connective tissue disorder
Authors: Curtis Jon , Wooles Nicola Rachel , Phillips David
Published: May 2021

A 47-year-old woman presented to the emergency department with sudden onset of swelling in her face, which had been triggered by blowing her nose. She had no other symptoms, but was known to have Ehlers-Danlos syndrome. A CT confirmed bilateral subcutaneous facial emphysema attributed to a defect in her left nasal cartilage. The condition was managed conservatively with prophylactic antibiotics and self-resolved within 48 hours. Only eight cases of sudden facial subcutaneous emphysema following nose blowing or sneezing have been found in the English literature and this is the first known case in a patient with a connective tissue disorder. In this case, her condition is suspected to have contributed to her presentation and may be underlying in other similar cases.
Case of vaso-occlusive retinopathy in Kikuchi-Fujimoto and lupus overlap syndrome
Authors: Ghadiri Nima , Stanford Miles
Published: May 2021

A 35-year-old woman presented with a constellation of systemic symptoms: rashes, weight loss, arthralgia and mouth ulcers. Six months afterwards, she experienced bilateral and sequential reduction in vision, and was found to have bilateral vaso-occlusive retinopathy, with critical macular ischaemia in the left eye. Her serological markers were consistent with a diagnosis of lupus. A lymph node biopsy confirmed Kikuchi-Fujimoto disease, a benign condition of unknown cause characterised by fever, cervical and axillary lymphadenopathy. Given that this overlap syndrome was associated with a number of systemic features and had affected the eyes, an immunosuppressive regime with rituximab was considered prudent. This rendered her vasculitis stable and non-progressive, and there were signs of partial retinal microvasculature recovery on optical coherence tomography angiography. There is increasing evidence of an overlap between Kikuchi-Fujimoto disease and systemic lupus erythematosus, which is associated with vaso-occlusive retinopathy. In these instances, a multidisciplinary approach is warranted, with consideration of appropriate treatment in order to prevent harmful sequelae of vasculitis. Our treatment with rituximab abated the disease process, although close follow-up is paramount to monitor results and side-effects of treatment.
Diffuse gallbladder wall thickening in autoimmune hepatitis: an unusual presentation
Authors: Rattananukrom Chitchai , Angkathunyakul Napat , Sobhonslidsuk Abhasnee
Published: May 2021

A 63-year-old woman presented with jaundice and epigastric pain for 2 weeks. Physical examination revealed marked jaundice, and palpable gallbladder with right upper quadrant tenderness. Liver function test was remarkable for hepatocellular injury pattern. Antinuclear antibody and anti-smooth muscle antibody were positive with high titre and serum IgG was elevated more than upper normal range. Ultrasound and CT scan demonstrated mildly diffuse periportal oedema of liver parenchyma and markedly diffuse gallbladder wall thickening up to 2 cm. Liver histology showed focal interface hepatitis with prominent plasma cell infiltration and cluster formation, moderate lobular spotty necrosis and emperipolesis consistent with autoimmune hepatitis. The patient was treated with steroid and azathioprine. She had complete resolution of symptoms and normal biochemical laboratory results. Diffuse gallbladder thickening was seen in acute hepatitis from definite autoimmune hepatitis.