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1.  Peripheral Blood Stem Cell Transplant Related Plasmodium falciparum Infection in a Patient with Sickle Cell Disease 
Transfusion  2012;52(12):2677-2682.
Although transmission of Plasmodium falciparum (Pf) infection during red blood cell 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. Pf HRP2 antigen was measured by ELISA on whole blood and plasma. Pf DNA was detected in whole blood and stem cell retention samples by real-time PCR using Pf species–specific primers and probes. Genotyping of 8 Pf microsatellites was performed on genomic DNA extracted from whole blood.
Pf was not detected by molecular, serologic or parasitologic means in samples from the recipient until day 11 post-transplant, coincident with the onset of symptoms. In contrast, Pf antigen was retrospectively detected in stored plasma collected 3 months prior to transplant from the asymptomatic donor. Pf DNA was detected in whole blood from both the donor and recipient post-transplant, and genotyping confirmed shared markers between donor and recipient Pf strains. Look back analysis of red blood cell donors was negative for Pf infection.
These findings are consistent with transmission by the stem cell product and have profound implications with respect to the screening of potential stem cell donors and recipients from malaria-endemic regions.
PMCID: PMC3408807  PMID: 22536941
Plasmodium falciparum; Sickle Cell Disease; Peripheral Blood Stem Cell Transplant; Real-Time PCR; PfHRP2 Antigen ELISA
2.  Disseminated Strongyloides stercoralis Infection in HTLV-1-Associated Adult T-Cell Leukemia/Lymphoma 
Acta Haematologica  2011;126(2):63-67.
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. Ten days later, the patient developed diarrhea, vomiting, fever, cough, skin rash, and a deteriorating mental status. She was diagnosed with disseminated S. stercoralis. Corticosteroids were discontinued and the patient received anthelmintic therapy with ivermectin and albendazole with complete clinical recovery.
PMCID: PMC3080579  PMID: 21474923
Adult T-cell leukemia; Alemtuzumab; Corticosteroid; Disseminated Strongyloides; HTLV-1; Human T-cell lymphotropic virus type-1
3.  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. Miltefosine treatment cured two patients with L. infantum chagasi. A wide variety of Leishmania responded to liposomal amphotericin B administered for 5–7 days. Three patients with L. V. braziliensis, one patient with L. tropica, and two patients with L. infantum chagasi were treated successfully. One person with L. V. braziliensis healed slowly because of a resistant bacterial superinfection, and a second patient with L. infantum chagasi relapsed and was retreated with miltefosine. These drugs were reasonably well-tolerated. In this limited case series, alternative non-antimony–based regimens were convenient, safe, and effective.
PMCID: PMC3005496  PMID: 21212212
4.  An Enhanced Method for the Identification of Leishmania spp. using Real-Time PCR and Sequence Analysis of the 7SL RNA Gene Region 
The accurate identification of Leishmania species is important for the treatment of infected patients. Molecular methods offer an alternative to time consuming traditional laboratory techniques for species determination. We redesigned a 7SL rRNA gene based PCR and sequence assay for increased species identification. DNA extracted from 17 reference strains and 10 cultured clinical isolates was examined. Sequence comparison was used successfully to identify organisms to the complex level with intercomplex similarity ranging from 77.5% to 98.4%. Many species within each complex were discriminated accurately by this method including: L. major, L. tropica, L. aethiopica, L. guyanensis, and the previously indistinguishable L. brasiliensis and L. panamensis. The L. donovani complex members remain indistinguishable by this method, as are the representatives of L. amazonensis/L. garnhami and L. mexicana/L. pifanoi.
PMCID: PMC2856081  PMID: 20226334
5.  Legionella feeleii Serotype 2 Pneumonia in a Man with Chronic Lymphocytic Leukemia: a Challenging Diagnosis ▿  
Journal of Clinical Microbiology  2010;48(6):2294-2297.
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.
PMCID: PMC2884502  PMID: 20357216
6.  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, Illinois 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 were evaluated, and point mutations were compared with other reports of isolates derived from adult or mixed patient populations. 9% of isolates had reduced susceptibility to one or more of these fluoroquinolones by Etest: ciprofloxacin, levofloxacin, moxifloxacin. A single point mutation (Ser-79) in parC seemed responsible for the reduced susceptibility. Resistant S. pyogenes isolates were compared using M/emm type, RepPCR, and pulsed-field gel electrophoresis (PFGE). RepPCR provided no more separation of strains than M/emm typing and PFGE results with SgrA1 were more discriminatory than with SmaI. The majority of these isolates were M/emm type 6. PFGE analysis using SgrA1 demonstrated 2 different resistant strains among the M/emm type 6 isolates. The findings suggest that a population of S. pyogenes with an intrinsic reduced susceptibility to fluoroquinolones exists in pediatric clinical isolates. Monitoring of amino acid changes in both parC and gyrA will assist in the prediction of emergence of high level fluoroquinolone resistance.
PMCID: PMC2572761  PMID: 18554840
Streptococcus pyogenes; pediatric isolates; M/emm type; fluoroquinolones; resistance; point mutation
7.  Detection of Vaccinia Virus DNA, but not Infectious Virus, in the Blood of Smallpox Vaccine Recipients 
Vaccine  2007;25(23):4571-4574.
The authors of a recent study suggested that the duration of deferral for blood donations by smallpox vaccinees should be extended, based on detection of vaccinia virus DNA in 5 blood samples by PCR and the potential for viremia. We found that 4 of 202 blood specimens (from 3 of 27 smallpox vaccinees) were positive for vaccinia virus DNA by PCR; none were positive for virus by culture. Throat swabs were negative by PCR and culture. Thus, while some blood specimens contained vaccinia virus DNA, infectious virus was not detected. Current guidelines for deferral of blood donation in vaccinees seem appropriate.
PMCID: PMC2082009  PMID: 17493714
smallpox vaccine; vaccinia virus; poxvirus
9.  Comparison of Methods for Detection of Vaccinia Virus in Patient Specimens 
Journal of Clinical Microbiology  2005;43(9):4602-4606.
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. DFA performed better with specimens from patients who had not previously received the vaccine. PCR was positive for longer times postvaccination than was SVA. Infectious virus could be recovered after 45 min of acetone fixation of shell vial coverslips. Commercially available polyclonal antibodies cross-reacted with other orthopoxviruses and herpes simplex 1, but commercially available monoclonal antibodies were specific for vaccinia virus. In summary, PCR was the most sensitive test for detecting vaccinia virus in clinical specimens, while the DFA was the most rapid but the least sensitive test.
PMCID: PMC1234082  PMID: 16145113
10.  Large-Scale Screening of Nasal Swabs for Bacillus anthracis: Descriptive Summary and Discussion of the National Institutes of Health's Experience 
Journal of Clinical Microbiology  2002;40(8):3012-3016.
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. Several thousand people who worked at these sites were screened for spore exposure by collecting nasal swab samples. We describe here a screening protocol which we, as a level A laboratory, used on very short notice to process a large number of specimens (3,936 swabs) in order to report preliminary results as quickly as possible. Six isolates from our screening met preliminary criteria for Bacillus anthracis identification and were referred for definitive testing. Although none of the isolates was later confirmed to be B. anthracis, we studied these isolates further to define their biochemical characteristics and 16S rRNA sequences. Four of the six isolates were identified as Bacillus megaterium, one was identified as Bacillus cereus, and one was an unidentifiable Bacillus sp. Our results suggest that large-scale nasal-swab screening for potential exposure to anthrax spores, particularly if not done immediately postexposure, may not be very effective for detecting B. anthracis but may detect a number of Bacillus spp. that are phenotypically very similar to B. anthracis.
PMCID: PMC120640  PMID: 12149367
11.  Resistance to Multiple Fluoroquinolones in a Clinical Isolate of Streptococcus pyogenes: Identification of gyrA and parC and Specification of Point Mutations Associated with Resistance 
Antimicrobial Agents and Chemotherapy  2000;44(11):3196-3198.
A strain of Streptococcus pyogenes resistant to multiple fluoroquinolones was isolated from the blood of an immunocompromised patient. Resistance to fluoroquinolones in S. pyogenes has not been previously studied. Compared to 10 sensitive strains of S. pyogenes, the fluoroquinolone-resistant clinical isolate of S. pyogenes presented point mutations in gyrA, predicting that serine-81 was changed to phenylalanine and that methionine-99 was changed to leucine, and in parC, predicting that serine-79 was changed to tyrosine. The mechanism of fluoroquinolone resistance in this isolate of S. pyogenes appears to be analogous to previously reported mechanisms for Streptococcus pneumoniae.
PMCID: PMC101632  PMID: 11036052
12.  Performance of Three Enzyme Immunoassays and Two Direct Fluorescence Assays for Detection of Giardia lamblia in Stool Specimens Preserved in ECOFIX 
Journal of Clinical Microbiology  2000;38(7):2781-2783.
ECOFIX is a single-vial stool preservative that is both formalin- and mercury-free. We evaluated the abilities of three commercial Giardia lamblia-specific enzyme immunoassays (EIAs) (ProSpecT Giardia Microplate Assay [Alexon-Trend Inc.], Giardia Test [Techlab], and Premier Giardia lamblia [Meridian Diagnostics, Inc.]) and two commercial direct fluorescent-antibody (FA) assays for G. lamblia (Crypto/Giardia IF Test [Techlab] and Merifluor Cryptosporidium/Giardia [Meridian Diagnostics, Inc.]) to detect G. lamblia in 34 G. lamblia-positive and 44 G. lamblia-negative stool specimens (determined by traditional examination for ova and parasites) preserved in ECOFIX compared to their abilities to detect G. lamblia in the same specimens preserved in formalin as the “gold standard” for each assay. Of the 34 formalin-fixed positive specimens, the number detected by each assay was as follows:, Alexon EIA, 34; Meridian EIA, 27; Techlab EIA, 29; Meridian FA assay, 31; and Techlab FA assay, 28. Both FA tests and the Alexon EIA performed well with ECOFIX, but the other two EIAs detected fewer positive specimens (the difference was statistically significant with the Techlab EIA) when ECOFIX was the preservative. Use of G. lamblia cyst antigen from cultured organisms preserved in formalin and ECOFIX demonstrated that the Alexon EIA could detect smaller amounts of antigen in ECOFIX than the other two EIAs could and suggested that cyst antigen is more stable in formalin. We recommend that laboratories use an FA assay or the Alexon EIA if they plan to use ECOFIX as their stool preservative.
PMCID: PMC87032  PMID: 10878088
13.  Evaluation of Two Rapid Assays for Detection of Clostridium difficile Toxin A in Stool Specimens 
Journal of Clinical Microbiology  1999;37(9):3044-3047.
Rapid laboratory diagnosis of Clostridium difficile-associated diarrhea (CDAD) is highly desirable in the setting of hospital cost containment. We tested 654 stool specimens to compare the performance of two assays for rapid detection of toxin A, the Immunocard Toxin A test (Meridian Diagnostics, Inc.) and the Culturette Brand Toxin CD enzyme immunoassay (EIA) (Becton Dickinson Microbiology Systems), with a cytotoxin assay (Cytotoxi Test; Advanced Clinical Diagnostics) and culture on cycloserine-cefoxitin-fructose agar followed by determination of the production of toxins A and B. A chart review was performed for patients whose stool specimens provided positive results on one to three of the assays. With the “gold standard” of all four assays positive or chart review evidence of CDAD, 97 (14.8%) stool specimens were positive by one or more assays and 557 (85.2%) were negative by all methods. Total agreement for all assays was 90.5% (592 of 654). The sensitivity, specificity, positive predictive value, and negative predictive value for toxigenic culture were 94.7, 98.6, 87.1, and 99.5%, respectively, for toxigenic culture; 87.7, 98.6, 86.2, and 98.8%, respectively, for the cytotoxin assay; 71.9, 99.3, 91.1, and 97.3%, respectively, for the Immunocard; and 68.4, 99.1, 88.6, and 96.9%, respectively, for the Culturette EIA. While easy to perform and highly specific, these rapid assays do not appear to be sufficient for accurate diagnosis of CDAD.
PMCID: PMC85451  PMID: 10449503
14.  Blinded, Externally Controlled Multicenter Evaluation of Light Microscopy and PCR for Detection of Microsporidia in Stool Specimens 
Journal of Clinical Microbiology  1998;36(6):1814-1818.
The quality parameters for the detection of microsporidia in identical sets of 50 stool samples were determined for six laboratories where technicians used light microscopy and for six laboratories where technicians used PCR. The average overall sensitivities were 67% (89% for patient samples only) for the PCR laboratories and 54% (80% for patient samples only) for the light microscopy laboratories. Specificities were 98 and 95%, respectively. Differences in results were most apparent between the individual laboratories rather than between the two major methods used.
PMCID: PMC104932  PMID: 9620432

Results 1-14 (14)