Publications (6)19.73 Total impact
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Article: Monoclonal antibodies to VP1 recognize a broad range of enteroviruses.
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ABSTRACT: Enteroviruses (EVs) are common seasonal viruses that are associated with a variety of diseases. High-quality monoclonal antibodies (MAbs) are needed to improve the accuracy of EV diagnosis in clinical laboratories. In the present study, the full-length VP1 genes of poliovirus 1 (Polio 1) and coxsackievirus B3 (Cox B3) were cloned, and the encoded proteins were expressed and used as antigens in an attempt to raise broad-spectrum MAbs to EVs. Two pan-EV MAbs were isolated: one raised against Polio 1 VP1 and the other against Cox B3 VP1. The binding sites of both pan-EV MAbs were mapped to an amino acid sequence within a conserved region in the N terminus of Polio 1 VP1 by peptide and competition enzyme-linked immunosorbent assay. Two additional MAbs, an EV70-specific MAb and an EV71/Cox A16-bispecific MAb, developed against EV70 and 71 VP1 proteins, were pooled with the two pan-EV MAbs (pan-EV MAb mix) and tested for their sensitivity and specificity in the staining of various virus-infected cells. The pan-EV MAb mix detected all 40 prototype EVs tested and showed no cross-reactivity to 18 different non-EV human viruses. Compared with two commercially available EV tests, the pan-EV MAb mix exhibited higher specificity than one test and broader spectrum reactivity than the other. Thus, our study demonstrates that full-length Polio 1 VP1 and Cox B3 VP1 can serve as effective antigens for developing a pan-EV MAb and that the pan-EV MAb mix can be used for the laboratory diagnosis of a wide range of EV infections.Journal of clinical microbiology 09/2009; 47(10):3108-13. · 4.16 Impact Factor -
Article: Identification of a novel human gammapapillomavirus species.
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ABSTRACT: By using random PCR amplification, shotgun sequencing and sequence similarity searches, we analysed nucleic acids present in cell cultures inoculated with samples from unexplained cases of encephalitis. We identified a divergent human papillomavirus (HPV) sequence originating from a rectal swab. The full genome was amplified by inverse PCR and sequenced. The prototype of the sixth gammapapillomavirus species, HPV116, was not found in the patient's cerebrospinal fluid or respiratory secretions, nor in culture supernatants from other unexplained cases of encephalitis, indicating that its identification in an encephalitis patient was accidental.Journal of General Virology 08/2009; 90(Pt 10):2413-7. · 3.36 Impact Factor -
Article: An algorithm for the typing of enteroviruses and correlation to serotyping by viral neutralization.
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ABSTRACT: Human enteroviruses (HEVs) are common pathogens which cause a broad spectrum of illnesses ranging from asymptomatic infection to acute myocarditis and aseptic meningitis. The neutralization assay for serotype determination is labor-intensive and time-consuming. There is a need for a methodology that is more rapid and widely accessible. Our goals were to develop an algorithm to type enteroviruses which combines both serologic typing, based on indirect immunofluorescence assay (IFA) using type-specific monoclonal antibodies (mAbs) and genotyping, by DNA sequence analysis and to assess the correlation of both IFA and genotyping to traditional viral neutralization by type-specific antisera. Clinical specimens initially determined to be enterovirus positive by nucleic acid detection were grown in cell culture and typed using mAbs. Specimens that could not be typed by mAbs were subject to molecular analysis. Genotyping was performed by a combination of either a primary or semi-nested RT-PCR for a region within VP3/VP1 and followed by direct DNA sequencing of PCR products. Database homology comparisons and phylogenetic analysis were performed based on a defined region (303 nt) within the VP1 gene. We inoculated 134 enterovirus nucleic acid amplification-positive specimens into culture and 115 (86%) of these isolates were successfully typed by this algorithm. We have demonstrated a strong correlation between serotyping by viral neutralization to both IFA by type-specific mAbs and genotyping. Typing of human enteroviruses can be effectively performed using an integration of antibody-based and molecular methods.Journal of clinical virology: the official publication of the Pan American Society for Clinical Virology 07/2009; 45(4):334-40. · 3.12 Impact Factor -
Article: Creating a model program for influenza surveillance in California: results from the 2005-2006 influenza season.
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ABSTRACT: Influenza surveillance is valuable for monitoring trends in influenza-related morbidity and mortality. Using the 2005-2006 influenza season as an example, this paper describes a comprehensive influenza surveillance program used by the California Department of Public Health (CDPH). Data collected from patients evaluated for acute respiratory illness in a given week were reported and summarized the following week, including (1) electronic hospital pneumonia and influenza admission and antiviral usage records from Kaiser Permanente, (2) sentinel provider influenza-like illness (ILI) reports, (3) severe pediatric influenza case reports (e.g., children either hospitalized in intensive care or expired), (4) school clinic ILI evaluations, and (5) positive influenza test results from a network of academic, hospital, commercial, and public health laboratories and the state CDPH Viral and Rickettsial Disease Laboratory. Influenza activity in California in the 2005-2006 season was moderate in severity; all clinical and laboratory markers rose and fell consistently. Extensive laboratory characterization identified the predominant circulating virus strain as A/California/7/2004(H3N2), which was a component of the 2005-2006 influenza vaccine; 96% of samples tested showed adamantane resistance. By using multiple, complementary surveillance methods coupled with a strong laboratory component, the CDPH has developed a simple, flexible, stable, and widely accepted influenza surveillance system that can monitor trends in statewide influenza activity, ascertain the correlation between circulating strains with vaccine strains, and assist with detection of new strain variants. The methods described can serve as a model for influenza surveillance in other states.American Journal of Preventive Medicine 11/2007; 33(4):353-7. · 4.04 Impact Factor -
Article: Diagnosis of a critical respiratory illness caused by human metapneumovirus by use of a pan-virus microarray.
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ABSTRACT: A pan-virus DNA microarray (Virochip) was used to detect a human metapneumovirus (hMPV) strain associated with a critical respiratory tract infection in an elderly adult with chronic lymphocytic leukemia. This infection had previously eluded diagnosis despite extensive microbiological testing for possible etiologic agents. The patient's hMPV strain did not grow in viral culture, and only one of five specific reverse transcription-PCR assays for hMPV was positive.Journal of Clinical Microbiology 08/2007; 45(7):2340-3. · 4.15 Impact Factor -
Article: Clinical, epidemiologic, and environmental surveillance for ehrlichiosis and anaplasmosis in an endemic area of northern California.
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ABSTRACT: Two forms of tick-borne leukocytotropic rickettsioses have been recognized in California since the mid-1990s: human monocytic ehrlichiosis (HME) caused by Ehrlichia chaffeensis and human granulocytic anaplasmosis (HGA) caused by Anaplasma phagocytophilum. Between 1997 and 1999, two cases of HME and four cases of HGA were diagnosed in residents of southern Humboldt County, California. Environmental followup at case-patients' residences revealed dense populations of Ixodes pacificus ticks, particularly in grassy roadside areas. PCR evidence of A. phagocytophilum was detected in approximately 2.0% of I. pacificus; E. chaffeensis was not detected in any of 625 ticks tested. Serologic antibody to A. phagocytophilum was detected in two of 54 participants in a community epidemiologic study; one of these also had antibody to E. chaffeensis. Over 85% of study participants reported finding a tick on themselves in the preceding 12 mo. Residents of southern Humboldt County are at significant risk of tick bites and should take appropriate prevention measures to avoid infection with rickettsia and other tick-transmitted pathogens.Journal of Vector Ecology 07/2005; 30(1):4-10. · 0.88 Impact Factor
