bluuebunny/crossref_metadata_2025_split huggingface dataset:
Imipenem Resistance of
Enterobacter aerogenes
Mediated by Outer Membrane Permeability
Authors: Bornet Charléric , Davin-Regli Anne , Bosi Claude , Pages Jean-Marie , Bollet Claude 
Published: December 2019

ABSTRACT

Multidrug-resistant
Enterobacter aerogenes
strains are increasingly isolated in Europe and especially in France. Treatment leads to imipenem resistance, because of a lack of porin. We studied the evolution of resistance in 29 strains isolated from four patients during their clinical course. These strains belonged to the prevalent epidemiological type observed in France in previous studies (C. Bosi, et al., J. Clin. Microbiol. 37:2165–2169, 1999; A. Davin-Regli et al., J. Clin. Microbiol. 34:1474–1480, 1996). They also harbored a TEM-24 extended-spectrum β-lactamase-coding gene. Thirteen strains were susceptible to gentamicin and resistant to imipenem and cefepime. All of the patients showed
E. aerogenes
strains with this resistance after an imipenem treatment. One patient showed resistance to imipenem after a treatment with cefpirome. Twelve of these 13 strains showed a lack of porin. Cessation of treatment with imipenem for three patients was followed by reversion of susceptibility to this antibiotic and the reappearance of porins, except in one case. For one patient, we observed three times in the same day the coexistence of resistant strains lacking porin and susceptible strains possessing porin. The emergence of multidrug-resistant
E. aerogenes
strains is very disquieting. In our study, infection by
E. aerogenes
increased the severity of the patients' illnesses, causing a 100% fatality rate.
An Antigen Capture Enzyme-Linked Immunosorbent Assay Reveals High Levels of the Dengue Virus Protein NS1 in the Sera of Infected Patients
Authors: Young Paul R. , Hilditch Paige A. , Bletchly Cheryl , Halloran Wendy 
Published: December 2019

ABSTRACTWe describe the development of a capture enzyme-linked immunosorbent assay for the detection of the dengue virus nonstructural protein NS1. The assay employs rabbit polyclonal and monoclonal antibodies as the capture and detection antibodies, respectively. Immunoaffinity-purified NS1 derived from dengue 2 virus-infected cells was used as a standard to establish a detection sensitivity of approximately 4 ng/ml for an assay employing monoclonal antibodies recognizing a dengue 2 serotype-specific epitope. A number of serotype cross-reactive monoclonal antibodies were also shown to be suitable probes for the detection of NS1 expressed by the remaining three dengue virus serotypes. Examination of clinical samples demonstrated that the assay was able to detect NS1 with minimal interference from serum components at the test dilutions routinely used, suggesting that it could form the basis of a useful additional diagnostic test for dengue virus infection. Furthermore, quantitation of NS1 levels in patient sera may prove to be a valuable surrogate marker for viremia. Surprisingly high levels of NS1, as much as 15 μg/ml, were found in acute-phase sera taken from some of the patients experiencing serologically confirmed dengue 2 virus secondary infections but was not detected in the convalescent sera of these patients. In contrast, NS1 could not be detected in either acute-phase or convalescent serum samples taken from patients with serologically confirmed primary infection. The presence of high levels of secreted NS1 in the sera of patients experiencing secondary dengue virus infections, and in the context of an anamnestic antibody response, suggests that NS1 may contribute significantly to the formation of the circulating immune complexes that are suspected to play an important role in the pathogenesis of severe dengue disease.
Evaluation of the Indirect Hemagglutination Assay for Diagnosis of Acute Leptospirosis in Hawaii
Authors: Effler Paul V. , Domen Harry Y. , Bragg Sandra L. , Aye Tin , Sasaki David M. 
Published: December 2019

ABSTRACT

Timely diagnosis of leptospirosis is important to ensure a favorable clinical outcome. The definitive serologic assay, the microscopic agglutination test (MAT), requires paired sera and is not useful for guiding early clinical management. The only screening test approved for use in the United States, the indirect hemagglutination assay (IHA), has not undergone extensive field evaluation. To assess the performance of the leptospirosis IHA in Hawaii, serum from patients evaluated for leptospirosis between 1992 and 1997 were tested with the IHA at the Hawaii State Laboratories Division and with the MAT at the Centers for Disease Control and Prevention. Leptospirosis was considered confirmed by a fourfold rise in MAT titer and/or a positive culture. A total of 92 (41%) of 226 specimens from 114 persons with confirmed leptospirosis were found positive by IHA. Only 18 (15%) of 119 specimens obtained within 14 days of onset were IHA positive, compared to 74 (69%) of 107 specimens collected more than 14 days after onset (
P
<0.001). Repeat testing ultimately resulted in 78 (68%) of the confirmed cases having at least one specimen found positive by IHA. Thirteen different presumptive infecting serogroups were identified among 251 specimens with an MAT titer of ≥200 and obtained from persons with confirmed or probable leptospirosis. Fifty (68%) of 73 specimens with Icterohaemorrhagiae as the presumptive infecting serogroup were found positive by IHA, compared to 44 (47%) of 93 specimens with Australis as the presumptive infecting serogroup (
P
, 0.01). The IHA test was positive for 3 (1%) of 236 specimens from 154 persons without leptospirosis. The sensitivity of the leptospirosis IHA in Hawaii was substantially below figures reported previously, particularly early in the course of illness, limiting its usefulness for diagnosing acute infection. Since the presumptive infecting serogroup affected IHA results and the prevalence of serovars varies with geography, the performance of the IHA should be assessed locally. More sensitive leptospirosis screening tests are needed in Hawaii.
Recombinant Antigens To DetectToxoplasma gondii-Specific Immunoglobulin G and Immunoglobulin M in Human Sera by Enzyme Immunoassay
Authors: Aubert D. , Maine G. T. , Villena I. , Hunt J. C. , Howard L. , Sheu M. , Brojanac S. , Chovan L. E. , Nowlan S. F. , Pinon J. M. 
Published: December 2019

ABSTRACTWe have evaluated the diagnostic utility of elevenToxoplasma gondiirecombinant antigens (P22 [SAG2], P24 [GRA1], P25, P28 [GRA2], P29 [GRA7], P30 [SAG1], P35, P41 [GRA4], P54 [ROP2], P66 [ROP1], and P68) in immunoglobulin G (IgG) and IgM recombinant enzyme-linked immunosorbent assays (Rec-ELISAs). Following an initial evaluation, six recombinant antigens (P29, P30, P35, P54, P66, and P68) were tested in the IgG and IgM Rec-ELISAs with four groups of samples which span the toxoplasmosis disease spectrum (negative, chronic infection, acute infection, and recent seroconversion). Our results suggest that the combination of P29, P30, and P35 in an IgG Rec-ELISA and the combination of P29, P35, and P66 in an IgM Rec-ELISA can replace the tachyzoite antigen in IgG and IgM serologic tests, respectively. The relative sensitivity, specificity, and agreement for the IgG P29-P30-P35 Rec-ELISA were 98.4, 95.7, and 97.2%, respectively. The resolved sensitivity, specificity, and agreement for the IgM P29-P35-P66 Rec-ELISA were 93.1, 95.0, and 94.5%, respectively. Relative to the tachyzoite-based immunocapture IgM assay, the IgM P29-P35-P66 Rec-ELISA detects fewer samples that contain IgG antibodies with elevated avidity from individuals with an acute toxoplasmosis.
Rapid, Efficient Detection and Drug Susceptibility Testing of
Mycobacterium tuberculosis
in Sputum by Microscopic Observation of Broth Cultures
Authors: Caviedes Luz , Lee Tien-Shun , Gilman Robert H. , Sheen Patricia , Spellman Emily , Lee Ellen H. , Berg Douglas E. , Montenegro-James Sonia ,   The Tuberculosis Working Group in Peru
Published: December 2019

ABSTRACT

Inexpensive, rapid, and reliable methods of detecting infection by and drug susceptibility of
Mycobacterium tuberculosis
(MTB) are crucial to the control of tuberculosis. The novel microscopic observation broth-drug susceptibility assay (MODS) detects early growth of MTB in liquid medium, allowing more timely diagnosis and drug susceptibility testing. Sputum samples from hospitalized patients in Peru were analyzed by using stains, culture, and PCR. Sensitivity of MODS (92%) compared favorably with the most sensitive of the other culture methods (93%). Sputum samples positive for tuberculosis were tested for susceptibility to isoniazid and rifampin with the microwell alamar blue assay (MABA) and MODS. In 89% of cases, there was concordance between MODS and MABA. Of the diagnostic and susceptibility testing methods used, MODS yielded results most rapidly (median, 9.0 and 9.5 days, respectively). MODS is a rapid, inexpensive, sensitive, and specific method for MTB detection and susceptibility testing; it is particularly appropriate for use in developing countries burdened by significant infection rates and increasing numbers of multiple-drug-resistant cases.
Report of the First Human Case of Lobomycosis in the United States
Authors: Burns Robert A. , Roy J. Stephen , Woods Cavan , Padhye Arvind A. , Warnock David W. 
Published: December 2019

ABSTRACT

We describe the first human case of lobomycosis caused by
Lacazia loboi
in a 42-year-old white male resident of Georgia. The patient had traveled to Venezuela 7 years earlier, where he had planned to rappel down Angel Falls in Canaima. Although he never actually rappelled the falls, he did walk under the falls at least three times, exposing himself to the high water pressures of the falls. He noticed a small pustule with surrounding erythema developing on the skin of his right chest wall. The lesion gradually increased in size and had an appearance of a keloid. For cosmetic reasons, the patient sought medical treatment to remove the lesion. After an uncomplicated excision of the lesion, the patient recovered completely. The excised tissue was fixed in formalin for pathologic examination. Tissue sections stained by hematoxylin and eosin, periodic acid-Schiff stain, and Gomori methenamine silver stain procedures showed numerous histiocytes, multinucleated giant cells, and numerous globose or subglobose, lemon-shaped cells producing multiple blastoconidia connected by narrow tube-like connectors and catenate chains of various lengths characteristic of
L. loboi.
Clinical Use of Capillary PCR To Diagnose
Mycoplasma
Pneumonia
Authors: Honda Junichi , Yano Takafumi , Kusaba Mikako , Yonemitsu Junko , Kitajima Hiromoto , Masuoka Megumi , Hamada Kaori , Oizumi Kotaro 
Published: December 2019

ABSTRACT

In the present study, serologic data were compared with data obtained by capillary PCR to establish the efficacy of capillary PCR for the determination of
Mycoplasma
infection in samples obtained from throat swabs, bronchoalveolar lavage fluids (BALF), and sputum of patients with
Mycoplasma
pneumonia. We performed PCR analysis for
Mycoplasma
DNA on a total of 325 samples from 197 patients with community-acquired pneumonia and in whom
Mycoplasma
pneumonia was suspected. There were 68 PCR-positive specimens. Review of the differences in PCR positivity rates based on the site of specimen collection showed the highest rate of detection (28.6%) from throat swabs. From among the 31 patients with significantly elevated titers of serum
Mycoplasma
antibodies, the PCR results were positive for 25 patients. Thus, capillary PCR had a sensitivity of 80.6% (25 of 31). Five of the six false-negative results were from throat swab specimens. Moreover, testing (PCR) had been performed only once for these five patients with false-negative results. From among the PCR-positive findings from BALF specimens, there were no false-positive results. BALF specimens were very useful, except for the technical procedures and increased patient burden required to obtain these specimens. We suggest that the use of throat swab specimens in capillary PCR is much more suitable for diagnosing
Mycoplasma
pneumonia in routine clinical practice; however, careful throat swab specimen collection and an increase in the number of times that the PCR is performed are necessary to reduce the rate of false-negative results.
Quantitation of Human Immunodeficiency Virus Type 1 RNA in Different Biological Compartments
Authors: Shepard Robin N. , Schock Jody , Robertson Kevin , Shugars Diane C. , Dyer John , Vernazza Pietro , Hall Colin , Cohen Myron S. , Fiscus Susan A. 
Published: December 2019

ABSTRACT
Little information is available describing viral loads in body fluids other than blood. In addition, the suitability of commercially available assays for human immunodeficiency virus type 1 (HIV-1) RNA quantitation has not been evaluated in most nonblood fluids. We compared Organon Teknika's nucleic acid sequence-based amplification method (NASBA) and Roche's Amplicor HIV-1 Monitor (reverse transcriptase PCR [RT-PCR]) for quantitating HIV-1 RNA in cerebrospinal fluid (CSF), saliva, breast milk, seminal plasma, and cervical-vaginal lavage fluid (CVL). Saliva and breast milk frequently demonstrated some inhibition in the RT-PCR assay, similar to the inhibition previously described in seminal plasma. Inhibition of the RT-PCR assay was not observed with CSF or CVL, nor in any of the NASBA assays. When fluids from HIV-infected individuals were tested by RT-PCR and NASBA, 73 and 27% of CSF samples and 60 and 40% of breast milk specimens had detectable RNA, respectively. These differences were not statistically significant. In cross-sectional studies using RT-PCR to measure viral RNA in paired blood plasma and CSF samples, 71% of blood plasma samples and 42% of CSF samples were positive. A similar analysis using NASBA with paired blood plasma and CVL, saliva, or seminal plasma samples revealed 91% were blood plasma positive and 55% were CVL positive, 76% were blood plasma positive and 46% were saliva positive, and 83% were blood plasma positive and 63% were seminal plasma positive. NASBA worked fairly well to quantitate HIV-1 RNA from all fluids without apparent inhibition. RT-PCR performed well on CVL and CSF, frequently with greater sensitivity, although its use in other fluids appears limited due to the presence of inhibitors. These studies demonstrate that viral loads in nonblood fluids were generally lower than in blood.
Transmission of
Pneumocystis carinii
DNA from a Patient with
P. carinii
Pneumonia to Immunocompetent Contact Health Care Workers
Authors: Vargas Sergio L. , A. Ponce Carolina , Gigliotti Francis , Ulloa Ana V. , Prieto Susana , Muñoz Maria P. , Hughes Walter T. 
Published: December 2019

ABSTRACT

The transmission of
Pneumocystis carinii
from person to person was studied by detecting
P. carinii
-specific DNA in prospectively obtained noninvasive deep-nasal-swab samples from a child with a documented
P. carinii
pneumonia (PCP), his mother, two contact health care workers, and 30 hospital staff members who did not enter the patient's room (controls). Nested-DNA amplification was done by using oligonucleotide primers designed for the gene encoding the mitochondrial large subunit rRNA of rat
P. carinii
(
P. carinii
f. sp.
carinii
) that amplifies all forms of
P. carinii
and internal primers specific for human
P. carinii
(f. sp.
hominis
).
P. carinii
f. sp.
hominis
DNA was detected in samples from the patient and all of his contacts versus none of the 30 hospital staff members. The results, as previously shown in murine models of
P. carinii
pneumonia, document that person-to-person transmission of
P. carinii
is possible. This observation suggests that immunocompromised patients not on PCP prophylaxis should not enter the room of a patient with PCP, and it also raises the question as to whether healthy contacts can transmit the disease to immunocompromised patients at risk.
Application of a Fluorogenic PCR Assay for Typing and Subtyping of Influenza Viruses in Respiratory Samples
Authors: Schweiger B. , Zadow I. , Heckler R. , Timm H. , Pauli G. 
Published: December 2019

ABSTRACT

A fluorogenic PCR-based method (TaqMan-PCR) was developed for typing and subtyping of influenza virus genomes in clinical specimens. The TaqMan-PCR employs a probe technology that exploits the endogenous 5′–3′ nuclease activity of the
Taq
DNA polymerase to allow direct detection of the amplicon by release of a fluorescent reporter during the PCR. Therefore, post-PCR analysis is avoided since hybridization with the fluorogenic probe and quantification of the amplified product is performed simultaneously during PCR cycling. The specificity of the method was evaluated on 86 influenza A (25 H1N1 and 61 H3N2) and 49 influenza B virus reference strains and isolates. The sensitivity of the technique was found to be at the level of 0.1 50% tissue culture infective dose. This TaqMan-PCR was applied prospectively to surveillance work by community-based sampling in Germany during the last two influenza seasons. Seven hundred five throat swabs were analyzed during the winter of 1997–1998. A total of 195 of 705 samples (28%) were positive by PCR. Influenza viruses could be isolated from 125 specimens (18%). During the 1998–1999 season, 1,840 respiratory samples were received. Influenza viruses were isolated from 281 specimens (15%) out of 525 throat swabs (29%) which were positive for influenza A or B virus by TaqMan-PCR. Further differentiation of influenza A virus-positive swabs revealed an intensive circulation of the subtype H3N2 during both seasons, 1997–1998 and 1998–1999. The TaqMan-PCR was much more sensitive than culture and revealed an excellent correlation for typing and subtyping of influenza viruses when samples were positive by both methods.
A Novel Multiresistant
Streptococcus pneumoniae
Serogroup 19 Clone from Washington State Identified by Pulsed-Field Gel Electrophoresis and Restriction Fragment Length Patterns
Authors: Luna Vicki A. , Jernigan Daniel B. , Tice Alan , Kellner James D. , Roberts Marilyn C. 
Published: December 2019

ABSTRACT

In 1997, a cluster of multiresistant invasive serogroup 19 pneumococcus infections, including two fatalities, was reported in Washington State. Further investigation identified other cases. Fourteen Washington
Streptococcus pneumoniae
isolates, four from Alaska, and eight isolates from eastern Canada with reduced penicillin susceptibility (MIC of ≥1 μg/ml) were included in the study. Pulsed-field gel electrophoresis (PFGE) with
Apa
I,
Sac
II, and
Sma
I restriction enzymes and IS
1167
and
mef
restriction fragment length polymorphism (RFLP) pattern analysis were performed. Twenty of the 26 isolates had identical or related PFGE patterns, with two or all three enzymes, and identical or related IS
1167
RFLP patterns, indicating that they were genetically related. These 20 isolates contained the
mef
gene conferring erythromycin resistance and had identical
mef
RFLP patterns. The PFGE and RFLP patterns were distinct from those of six multiresistant clones previously described and suggest that a new multiresistant clone has appeared in Washington, Alaska, and eastern Canada. This newly characterized clone should be included in the Pneumococcal Molecular Epidemiology Network.
Reverse Cross Blot Hybridization Assay for Rapid Detection of PCR-Amplified DNA from
Candida
Species,
Cryptococcus neoformans
, and
Saccharomyces cerevisiae
in Clinical Samples
Authors: Posteraro Brunella , Sanguinetti Maurizio , Masucci Luca , Romano Lucio , Morace Giulia , Fadda Giovanni 
Published: December 2019

ABSTRACT

A PCR-based assay was developed to detect and identify medically important yeasts in clinical samples. Using a previously described set of primers (G. Morace et al., J. Clin. Microbiol. 35:667–672, 1997), we amplified a fragment of the
ERG11
gene for cytochrome P-450 lanosterol 14α-demethylase, a crucial enzyme in the biosynthesis of ergosterol. The PCR product was analyzed in a reverse cross blot hybridization assay with species-specific probes directed to a target region of the
ERG11
gene of
Candida albicans
(pCal),
C. guilliermondii
(pGui),
C.
(
Torulopsis
)
glabrata
(pGla),
C. kefyr
(pKef),
C. krusei
(pKru),
C. parapsilosis
(pPar),
C. tropicalis
(pTro), the newly described species
C. dubliniensis
(pDub),
Saccharomyces cerevisiae
(pSce), and
Cryptococcus neoformans
(pCry). The PCR-reverse cross blot hybridization assay correctly identified multiple isolates of each species tested. No cross-hybridization was detected with any other fungal, bacteria, or human DNAs tested. The method was tested against conventional identification on 140 different clinical samples, including blood and cerebrospinal fluid, from patients with suspected fungal infections. The results agreed with those of culture and phenotyping for all but six specimens (two of which grew yeasts not included in the PCR panel of probes and four in which PCR positivity-culture negativity was justified by clinical findings). Species identification time was reduced from a mean of 4 days with conventional identification to 7 h with the molecular method. The PCR-reverse cross blot hybridization assay is a rapid method for the direct detection and identification of yeasts in clinical samples.
Comparison of the Yields of Blood Cultures Using Serum or Plasma from Patients with Early Lyme Disease
Authors: Wormser Gary P. , Bittker Susan , Cooper Denise , Nowakowski John , Nadelman Robert B. , Pavia Charles 
Published: December 2019

ABSTRACT

In an initial experiment, culture-grown
Borrelia burgdorferi
was added to freshly collected uninfected human blood. This in vitro study demonstrated that more spirochetes were distributed into the plasma than into the serum fraction. In a subsequent clinical study,
B. burgdorferi
was recovered from plasma cultures of approximately 50% of 42 patients with early Lyme disease associated with erythema migrans. The rate of recovery from plasma cultures was significantly greater than that from serum cultures (
P
< 0.001).
Evaluation of the Sirscan Automated Zone Reader in a Clinical Microbiology Laboratory
Authors: Medeiros Antone A. , Crellin Joyce 
Published: December 2019

ABSTRACT

We compared readings of Kirby-Bauer plates by the Sirscan, an automated image analyzer that measures zone diameters, to those of experienced clinical microbiologists measuring zones with a hand-held caliper interfaced to a computer and with a ruler. To read plates of
Escherichia coli
,
Morganella morganii
, and
Pseudomonas aeruginosa
containing 12 antibiotic disks the Sirscan took 11 s; technologists took 28 s by caliper and 39 s by ruler. Reading times of four different technologists ranged from 22 to 44 s with the caliper and 10 to 12 s with Sirscan. Upon repeated testing zone size variation rarely exceeded 3 mm by caliper and 1 mm by Sirscan. Over a 4-month period, 368 clinical isolates were tested prospectively by both methods in the Clinical Microbiology Laboratory of the Miriam Hospital. There was good correlation of zone sizes for most antibiotics, but Sirscan zone diameter measurements tended to be 3 to 5 mm larger than caliper readings for ciprofloxacin, norfloxacin, aztreonam, erythromycin, clindamycin, and trimethoprim-sulfamethoxazole. Very major errors (resistant by caliper and susceptible by Sirscan) occurred with 10 of 3,770 readings (0.3%), mainly where breakpoint criteria lacked an intermediate zone. They occurred in testing staphylococci with amoxicillin-clavulanate (5 of 127 isolates, 3.9%), pseudomonas with piperacillin (1 of 28, 3.6%), coagulase-negative staphylococci with oxacillin (2 of 74, 2.7%), gram-negative bacilli with cefuroxime (1 of 209, 0.5%), and mixed species with trimethoprim-sulfamethoxazole (1 of 366, 0.3%). The Sirscan zone reader facilitates accurate, fully quantitative susceptibility testing in clinical microbiology laboratories.