A 58-year-old Korean-born woman with a history of seizures and psychiatric issues was found dead at home. Autopsy was notable for large, calcified nodules that had nearly replaced her right temporal lobe. Histologic examination revealed the presence of Paragonimus eggs.
View Article and Find Full Text PDFWe present 2 cases of Cokeromyces recurvatus in routine, liquid-based Papanicolaou tests (ThinPrep). Patient 1 is a healthy, asymptomatic, 26-year-old woman with no pertinent past medical history. Patient 2 is a healthy, asymptomatic, 47-year-old woman with no pertinent past medical history.
View Article and Find Full Text PDFTo investigate the performance of a nucleic acid amplification test (NAAT) for the diagnosis of Mycobacterium tuberculosis bacteremia, 5-ml aliquots of blood were inoculated into bioMérieux mycobacterial (MB) bottles and incubated, and 5-ml aliquots of blood were extracted and tested by real-time PCR. Of 25 samples from patients with M. tuberculosis bacteremia, 9 (36.
View Article and Find Full Text PDFThe role of Panton-Valentine leukocidin (PVL) in methicillin-resistant Staphylococcus aureus (MRSA) infections is unclear. PVL has been long associated with soft tissue infections and necrotizing pneumonia, but inconsistently with other site infections or mortality. The retrospective cohort study explores the association between PVL and bacteremia in colonized medical intensive care unit (ICU) patients with surveillance isolates and blood cultures.
View Article and Find Full Text PDFWe experienced significant problems while developing a PyrosequencingTM (Biotage, Uppsala, Sweden) assay to characterize the rifampin resistance-determining region of Mycobacteriumtuberculosis, a target with high guanosine-cytosine content. This paper describes the successful use of a modified pyrosequencing protocol through partial substitution of deoxyguanosine triphosphate with deoxyinosine triphosphate in the polymerase chain reaction.
View Article and Find Full Text PDFNontuberculous mycobacteria rarely cause bacteremia in HIV-negative patients. We describe 16 cases, including the first Mycobacterium neoaurum endocarditis. Nine cases were line related.
View Article and Find Full Text PDFOne limitation to the use of the polymerase chain reaction (PCR) to identify orthopedic infections has been apparent false-positive results, possibly due to the detection of dead bacteria. We recently showed that the use of DNA-binding agent propidium monoazide (PMA) could distinguish viable from heat-inactivated bacteria, and, in this study, we investigated whether the same technique can be applied to bacteria killed by two antibiotics with distinctly different mechanisms of action, a test of greater clinical relevance than thermal inactivation. Staphylococcus aureus and S.
View Article and Find Full Text PDFAfter isoniazid and rifampin (rifampicin), the next pivotal drug class in Mycobacterium tuberculosis treatment is the fluoroquinolone class. Mutations in resistance-determining regions (RDR) of the rpoB, katG, and gyrA genes occur with frequencies of 97%, 50%, and 85% among M. tuberculosis isolates resistant to rifampin, isoniazid, and fluoroquinolones, respectively.
View Article and Find Full Text PDFWe compared 2 methods for determining Escherichia coli viability in vitro. A 16S rDNA polymerase chain reaction (PCR) assay detected bacteria irrespective of viability. A groEL mRNA reverse transcriptase PCR was positive for 72 h but later became negative.
View Article and Find Full Text PDFMolecular techniques, such as the polymerase chain reaction (PCR) have high sensitivity when used to diagnose infection, but may detect DNA, RNA, and proteins from dead, as well as viable, bacteria. Propidium monoazide (PMA) is a DNA binding agent, that has the ability to penetrate only dead cells with compromised membranes and has been used in conjunction with real-time PCR to distinguish intact from dead bacterial cells. In this study, intact, heat-inactivated (dead), and intact/dead admixed Staphylococcus aureus (S.
View Article and Find Full Text PDFSalmonella septic arthritis is rare. Our objective was to identify bacterial species from joint fluid using a broad-range real-time PCR and pyrosequencing technique. We describe a case of bilateral Salmonella enterica serotype Enteritidis infection of right and left total knee arthroplasties.
View Article and Find Full Text PDFBacteria such as staphylococci commonly encountered in orthopaedic infections form biofilms and adhere to bone implants and cements. Various methods to disrupt the biofilm and enhance bacterial detection have been reported. We will describe the effectiveness of vortexing and sonication to improve the detection of biofilm-formative bacteria from polymethylmethacrylate by conventional quantitative bacterial culture and real-time quantitative PCR.
View Article and Find Full Text PDFSalmonella and Shigella species are routinely sought in stool specimens submitted for culture. It is a common practice to screen lactose-negative colonies by using triple sugar iron agar, lysine iron agar, and Christensen urea agar to determine if further identification is necessary. We designed and evaluated a novel combination of media, which are layered in a single tube, for screening isolates suspected to possibly represent Salmonella or Shigella.
View Article and Find Full Text PDFBackground: Nocardia brain abscess carries a higher morbidity and mortality rate than other bacterial cerebral abscesses, with reported mortality rates of 55% and 20% in immunocompromised and immunocompetent patients, respectively. To prevent a delay in diagnosis and treatment, an aggressive therapeutic approach is required. In the present study, a rapid and accurate molecular diagnostic approach using pyrosequencing (PS), a semiautomated molecular genotyping method of nucleotide sequencing-by-synthesis, was performed.
View Article and Find Full Text PDFTo rapidly identify Mycobacterium and Nocardia spp. without costly probes, we had implemented capillary electrophoresis (CE) in polymerase chain reaction (PCR)-restriction fragment length polymorphism (RFLP) analysis to analyze their 65-kDa heat shock protein (hsp65) gene. The PCR-RFLP analysis with CE (PRACE) involved only one restriction enzyme, HaeIII, and a single electrophoretic separation less than 10 min.
View Article and Find Full Text PDFBiofilms are complex microenvironments produced by microorganisms on surfaces. Ultrasonication disrupts biofilms and may make the microorganism or its DNA available for detection. We determined whether ultrasonication could affect our ability to detect bacteria adherent to a metal substrate.
View Article and Find Full Text PDFWe identified Mycobacterium tuberculosis DNA using real-time polymerase chain reaction on a specimen from an osteolytic lesion of a femoral condyle, in which the frozen section demonstrated granulomas. The process was much more rapid than is possible with culture. The rapid detection of M tuberculosis and the concomitant exclusion of granulomatous disease caused by nontuberculous mycobacteria or systemic fungi are necessary to appropriately treat skeletal tuberculosis.
View Article and Find Full Text PDFWe have developed a combined real-time PCR and pyrosequencing assay that successfully differentiated the vast majority of gram-positive and gram-negative bacteria when bacterial isolates were tested. The purpose of this study was to evaluate this assay on clinical specimens obtained from orthopedic surgeries, and to prospectively compare the results of "molecular Gram stain" with culture and conventional direct Gram stain. Forty-five surgical specimens were obtained from patients who underwent orthopedic surgery procedures.
View Article and Find Full Text PDFProgressive multifocal leukoencephalopathy (PML) is a demyelinating disease of the central nervous system caused by the JC polyoma virus. Electron microscopy and immunohistochemistry are the traditional methods of confirming the presence of the virus in brain biopsies from these patients. We studied the brain biopsies from 7 patients with PML and 6 patients without PML with chromogenic in situ hybridization (CISH) for the JC polyoma virus using a commercially available probe.
View Article and Find Full Text PDFWe evaluated the Roche LightCycler Staphylococcus M(GRADE) kits to differentiate between Staphylococcus aureus and coagulase-negative staphylococci in blood cultures growing clusters of gram-positive cocci. Testing 100 bottles (36 containing S. aureus), the assay was 100% sensitive and 98.
View Article and Find Full Text PDFThe bacteria associated with orthopaedic infections are usually common gram-positive and gram-negative bacteria. This fundamental grouping of bacteria is a necessary first step in the selection of appropriate antibiotics. Since polymerase chain reaction (PCR) is more rapid and may be more sensitive than culture, we developed a postamplification pyrosequencing method to subcategorize bacteria based on a few nucleotide polymorphisms in the 16S rRNA gene.
View Article and Find Full Text PDFDiagn Microbiol Infect Dis
April 2005
Pyrosequencing technology, sequencing by addition, was evaluated for categorization of mycobacterial isolates. One hundred and eighty-nine isolates, including 18 ATCC and Trudeau Mycobacterial Culture Collection (TMC) strains, were studied. There were 38 Mycobacterium tuberculosis complex, 27 M.
View Article and Find Full Text PDFWe evaluated 2 methods, a LightCycler PCR assay and pyrosequencing for the detection of the JC polyoma virus (JCV) in fixed brain tissue of 10 patients with and 3 control patients without progressive multifocal leukoencephalopathy (PML). Nucleic acid extraction was performed after deparaffinization and proteinase K digestion. The LightCycler assay differentiates the BK virus (BKV), JCV, and SV40 using melt curve analysis.
View Article and Find Full Text PDFSusceptibility profiles of medically important fungi in less-developed countries remain uncharacterized. We measured the MICs of amphotericin B, 5-flucytosine, fluconazole, itraconazole, and ketoconazole for Cryptococcus neoformans clinical isolates from Thailand, Malawi, and the United States and found no evidence of resistance or MIC profile differences among the countries.
View Article and Find Full Text PDFMycobacteria cause a variety of illnesses that differ in severity and public health implications. The differentiation of Mycobacterium tuberculosis from nontuberculous mycobacteria (NTM) is of primary importance for infection control and choice of antimicrobial therapy. Despite advances in molecular diagnostics, the ability to rapidly diagnose M.
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