Optimized Protocol for Testing Multipurpose Contact Lens Solution Efficacy Against Acanthamoeba.

Objectives: To evaluate the interlaboratory and intralaboratory reproducibility of a proposed protocol for multipurpose contact lens solution (MPS) disinfection efficacy against Acanthamoeba.

Methods: Acanthamoeba castellanii and Acanthamoeba polyphaga and four MPS with different biocidal agents were used to evaluate the protocol in two different laboratories. In addition to the negative control, a positive control and neutralization control were used.

The utility of bronchoalveolar lavage beta-D-glucan testing for the diagnosis of invasive fungal infections.

Objectives: To investigate the utility of beta-D-glucan (BDG) testing in bronchoalveolar lavage (BAL) fluid for the diagnosis of invasive fungal infection (IFI), as compared to BAL galactomannan (GM).

Methods: We retrospectively reviewed medical records of 132 consecutive patients at the National Institutes of Health (NIH) in whom BAL BDG testing was performed for diagnosis of pneumonia. Using the European Organization for Research and Treatment of Cancer/Mycoses Study Group guidelines, we determined which patients had proven or probable IFI, and assessed the diagnostic performance of BAL BDG testing, relative to BAL GM.

Peripheral blood stem cell transplant-related Plasmodium falciparum infection in a patient with sickle cell disease.

Background: Although transmission of Plasmodium falciparum (Pf) infection during red blood cell (RBC) transfusion from an infected donor has been well documented, malaria parasites are not known to infect hematopoietic stem cells. We report a case of Pf infection in a patient 11 days after peripheral blood stem cell transplant for sickle cell disease.

Study Design And Methods: Malaria parasites were detected in thick blood smears by Giemsa staining.

Identification of clinical isolates of anaerobic bacteria using matrix-assisted laser desorption ionization-time of flight mass spectrometry.

We evaluated the use of matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF) for the rapid identification of anaerobic bacteria that had been isolated from clinical specimens and previously identified by 16s rRNA sequencing. The Bruker Microflex MALDI-TOF instrument with the Biotyper Software was used. We tested 152 isolates of anaerobic bacteria from 24 different genera and 75 different species.

Use of adherence monitors as part of a team approach to control clonal spread of multidrug-resistant Acinetobacter baumannii in a research hospital.

Background: Multidrug-resistant Acinetobacter baumannii (MDRAB) is difficult to treat and eradicate. Several reports describe isolation and environmental cleaning strategies that controlled hospital MDRAB outbreaks. Such interventions were insufficient to interrupt MDRAB transmission in 2 intensive care unit-based outbreaks in our hospital.

Disseminated Strongyloides stercoralis infection in HTLV-1-associated adult T-cell leukemia/lymphoma.

A 55-year-old woman with human T-cell lymphotropic virus type-1 (HTLV-1)-associated adult T-cell leukemia (ATL) and a history of previously treated Strongyloides stercoralis infection received anti-CD52 monoclonal antibody therapy with alemtuzumab on a clinical trial. After an initial response, she developed ocular involvement by ATL. Alemtuzumab was stopped and high-dose corticosteroid therapy was started to palliate her ocular symptoms.

A species-specific approach to the use of non-antimony treatments for cutaneous leishmaniasis.

We used a species-specific approach to treat 10 patients with cutaneous leishmaniasis diagnosed using polymerase chain reaction. Non-antimony treatments (oral miltefosine, ketoconazole, and liposomal amphotericin B) were chosen as an alternative to pentavalent antimony drugs based on likely or proven drug efficacy against the infecting species. Leishmania Viannia panamensis was diagnosed in three patients and treated successfully with oral ketoconazole.

Toward molecular parasitologic diagnosis: enhanced diagnostic sensitivity for filarial infections in mobile populations.

The diagnosis of filarial infections among individuals residing in areas where the disease is not endemic requires both strong clinical suspicion and expert training in infrequently practiced parasitological methods. Recently developed filarial molecular diagnostic assays are highly sensitive and specific but have limited availability and have not been closely evaluated for clinical use outside populations residing in areas of endemicity. In this study, we assessed the performance of a panel of real-time PCR assays for the four most common human filarial pathogens among blood and tissue samples collected from a cohort of patients undergoing evaluation for suspected filarial infections.

Legionella feeleii serotype 2 pneumonia in a man with chronic lymphocytic leukemia: a challenging diagnosis.

Legionella feeleii has rarely been reported as causing pneumonia in patients with hematologic malignancies. We present a case of Legionella feeleii serotype 2 pneumonia with empyema in a man with chronic lymphocytic leukemia and describe the methods of identifying this organism using both standard methods and newer diagnostic techniques.

An enhanced method for the identification of Leishmania spp. using real-time polymerase chain reaction and sequence analysis of the 7SL RNA gene region.

The accurate identification of Leishmania spp. is important for the treatment of infected patients. Molecular methods offer an alternative to time-consuming traditional laboratory techniques for species determination.

Loss of erythromycin resistance genes from strains of Streptococcus pyogenes that have developed resistance to levofloxacin.

In the past 2 to 3 decades, erythromycin resistance in Streptococcus pyogenes has been decreasing, whereas fluoroquinolone resistance (or reduction in its susceptibility) has been reported often. Although a shift of M-type prevalence and decreased pressure from macrolides have been suggested for the decrease in erythromycin resistance, we hypothesized that this might also be a result of increased antimicrobial pressure from fluoroquinolone use. Levofloxacin resistance for 4 erythromycin-resistant parent strains was induced in vitro.

Use of a universal virus detection assay to identify human metapneumovirus in a hematopoietic stem cell transplant recipient with pneumonia of unknown origin.

Background: Development of uncommon viral infections in immunocompromised transplant recipients can pose major diagnostic challenges. We present a case report of an immunocompromised patient suffering from pneumonia, for which the causative agent was not identified by routine methods.

Objectives: To identify the potential cause of the pneumonia using a degenerate oligonucleotide primer (DOP)-PCR assay that is designed to detect all viruses.

An intrinsic pattern of reduced susceptibility to fluoroquinolones in pediatric isolates of Streptococcus pyogenes.

A total of 116 clinical isolates collected in 2003 from a tertiary pediatric hospital and a primary pediatric department in Chicago, IL, were screened for reduced susceptibility to selected fluoroquinolones by disc diffusion. Correlation between reduced susceptibility and point mutations in the quinolone resistance-determining region of parC and gyrA genes was evaluated, and point mutations were compared with other reports of isolates derived from adult or mixed patient populations. Nine percent of isolates had reduced susceptibility to 1 or more of these fluoroquinolones by Etest: ciprofloxacin, levofloxacin, and moxifloxacin.

Identification and antimicrobial susceptibility of lactic acid bacteria from retail fermented foods.

One important safety criterion of using lactic acid bacteria (LAB) in food applications is to ensure that they do not carry transferable antimicrobial resistance (AR) determinants. In this study, 63 LAB belonging to six genera, Streptococcus, Lactobacillus, Lactococcus, Enterococcus, Leuconostoc, and Pediococcus, were recovered from 28 retail fermented food products in Maryland, identified to species with 16S-23S rRNA spacer PCRs, and characterized for antimicrobial susceptibility against eight antimicrobials. Besides intrinsic resistance to ciprofloxacin or vancomycin in some lactobacilli, tetracycline resistance was observed in two Streptococcus thermophilus isolates from one cheese and one sour cream sample and was associated with the presence of a nonconjugative tet(S) gene.

Detection of vaccinia virus DNA, but not infectious virus, in the blood of smallpox vaccine recipients.

The authors of a recent study [Savona MR, Dela Cruz WP, Jones MS, Thornton JA, Xia D, Hadfield TL, et al. Detection of vaccinia DNA in the blood following smallpox vaccination. JAMA 2006; 295:1898-1900] suggested that the duration of deferral for blood donations by smallpox vaccinees should be extended, based on detection of vaccinia virus DNA in five blood samples by polymerase chain reaction (PCR) and the potential for viremia.

In vitro induction and selection of fluoroquinolone-resistant mutants of Streptococcus pyogenes strains with multiple emm types.

Objectives: To perform a systematic analysis of point mutations in the quinolone resistance determining regions (QRDRs) of the DNA gyrase and topoisomerase genes of emm type 6 and other emm types of Streptococcus pyogenes strains after in vitro exposure to stepwise increasing concentrations of levofloxacin.

Methods: Twelve parent strains of S. pyogenes, each with a different emm type, were chosen for stepwise exposure to increasing levels of levofloxacin followed by selection of resistant mutants.

Comparison of methods for detection of vaccinia virus in patient specimens.

We analyzed a shell vial culture assay (SVA), real-time PCR, and a direct fluorescent antibody assay (DFA) for rapid detection of vaccinia virus from vaccination sites of Dryvax vaccine recipients. Of 47 samples assayed, 100% were positive by PCR, 89% were positive by SVA, and 40% were positive by DFA. DFA was limited by the need for adequate numbers of cells, with 32% of samples inadequate for interpretation.

Evaluation of 7SL RNA gene sequences for the identification of Leishmania spp.

We evaluated the use of 7SL RNA gene sequences for the identification of Leishmania spp. A fragment (approximately 137 basepairs) of the 7SL RNA gene from 13 reference strains and 18 clinical isolates of 11 different Leishmania species was amplified and sequenced using conserved primers. Reference strains from each Leishmania spp.

Multidrug-resistant Corynebacterium striatum pneumonia in a heart transplant recipient.

Corynebacterium striatum is a rare, but likely underreported, cause of serious infections in immunocompromised hosts and generally is susceptible to multiple classes of antimicrobial agents. Here we report the first case of C. striatum infection in a solid organ transplant recipient.

Rapid detection of Clostridium difficile in stool using the VIDASR C. difficile Toxin A II assay.

A rapid laboratory diagnosis of Clostridium difficile-associated diarrhea (CDAD) is important in patient management and in the administration of appropriate therapeutic modalities. The VIDAS(R) C. difficile Toxin A II (CDA 2) assay (bioMerieux, Inc.

Large-scale screening of nasal swabs for Bacillus anthracis: descriptive summary and discussion of the National Institutes of Health's experience.

In October 2001, a letter containing a large number of anthrax spores was sent through the Brentwood post office in Washington, D.C., to a United States Senate office on Capitol Hill, resulting in contamination in both places.

Controversies in testing.

Recent reports of two nosocomial outbreaks of -associated disease caused by toxin A-deficient strains emphasize that these strains can cause disease. Laboratories using an assay that detects only toxin A as their primary diagnostic test risk misdiagnosis of cases or outbreaks in the institutions they serve. Repeat testing can account for a significant portion of a laboratory's testing workload.