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. Human enteroviruses (EVs) are classified into four species:Human enterovirus A (coxsackievirus A2 [Cox A2], A3, A5, A7, A8, A10, A12, A14, and A16 and EVs 71, 76, 89, 90, and 91), Human enterovirus B (Cox A9 and B1 to B6; echoviruses 1 to 7 [Echo 1 to 7], 9, 11 to 27, and 29 to 33; and EVs 69, 73 to 75, 77 to 88, 97, 100, and 101), Human enterovirus C (Cox A1, A11, A13, A17, A19 to A22, and A24; polioviruses 1 to 3 [Polio 1 to 3]; and EV96), and Human enterovirus D (EV68 and EV70) (14). Infection with these EVs causes a wide range of diseases in humans, from mild respiratory illness to severe aseptic meningitis. Diagnosis of EV infection depends mainly upon laboratory testing, since the clinical symptoms vary and overlap with other diseases. Laboratory diagnosis of EV infection is currently determined with either reverse transcription-PCR to detect EV RNA or by isolating the virus in cell culture followed by monoclonal antibody (MAb) staining (15,19). However, the two commercially available pan-EV MAbs used in the staining assay either fail to react with multiple EV serotypes (9, 19) or cross-react with other non-EVs (8, 22). The lack of availability of highly reactive and specific pan-EV MAbs for diagnosis of EV infection could be due to the difficulties in developing specific MAbs against the extensive antigenic diversity among EVs.EV capsid protein VP1 is one of four structural proteins of EV, and its antigenic homology among many different EV serotypes has been well documented (2,7,(16)(17)(18). The N te...

A colorimetric yield reduction assay, ELVIRA (enzyme-linked virus inhibitor reporter assay) HSV, was developed to determine the antiviral drug susceptibilities of herpes simplex virus (HSV). It uses an HSVinducible reporter cell line. This simple and rapid assay has an objective readout, low inoculum size, and good reproducibility. The results correlate well with those of the plaque reduction assay.The prevalence of herpes simplex virus (HSV) infections caused by a drug-resistant virus in immunocompromised patients has been demonstrated to be significant (3.5 to 7.1%) (1-4). This underlines the clinical importance of HSV drug susceptibility determinations for this patient group. The "gold standard," the plaque reduction assay (PRA), is laborious and time-consuming and has a subjective endpoint, and the results are often obtained too late to play a role in therapeutic decision making (5). There has been a considerable effort to develop less laborious and more rapid assays (8). One of the strategies was a modified PRA, which used a transgenic cell line expressing ␤-galactosidase upon infection with HSV and microscopic counting of blue plaques as a readout (9, 10).We describe a rapid, quantitative colorimetric antiviral drug susceptibility assay, ELVIRA (enzyme-linked virus inhibitor reporter assay) HSV (Diagnostic Hybrids, Inc.). The assay is based on the HSV-inducible reporter cell line BHKICP6 LacZ-5 (ELVIRA cells) stably transformed with the Escherichia coli lacZ gene under the control of the HSV type 1 (HSV-1) early promoter ICP6, which expresses ␤-galactosidase upon HSV infection (6). A yield reduction assay was set up in which virus is inoculated on human fibroblasts in the presence of antiviral drug. Subsequently, reporter ELVIRA cells, which represent an overlay readout cell line, are added. The ␤-galactosidase activity in the cell lysates reflects the number of infected reporter cells and, thereby, the yield of infectious virus after drug action.Confluent HFF cells were inoculated in triplicate with 0.1 ml of virus suspension and 0.1 ml of culture medium containing antiviral drugs (acyclovir [ACV] and foscarnet [PFA]) at different concentrations (7). After centrifugation (700 ϫ g)-enhanced virus adsorption for 1 h and incubation overnight at 37°C, a suspension of reporter ELVIRA cells (Diagnostic Hybrids, Inc., Athens, Ohio) was prepared from frozen stocks (final concentration, 29,000 cells/ml). The culture supernatant was aspirated, and 0.2 ml of the ELVIRA cell suspension was added and was allowed to settle. After overnight incubation, the culture supernatant was aspirated, 0.15 ml of 0.03% sodium desoxycholate solution was added, and cell cultures were lysed for 30 min. The ␤-galactosidase activity in the lysates was determined spectrophotometrically (optical density at 570 nm) after incubation for 15 to 90 min at 37°C with 0.1 ml of substrate solution (chlorophenol red-␤-D-galactopyranoside monosodium salt [3 mg/ml; Roche Diagnostics, Almere, The Netherlands] and 4.35 mM magnesium chloride in phosphat...

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The recent association of certain influenza A virus subtypes with clinically relevant phenotypes has led to the increasing importance of subtyping by clinical virology laboratories. To provide clinical laboratories with a definitive immunofluorescence assay for the subtyping of influenza A virus isolates, we generated a panel of monoclonal antibodies (MAbs) against the major circulating influenza A virus subtypes using multiple inactivated H1N1, H3N2, and 2009 H1N1 strains individually as immunogens. Eleven MAbs that target hemagglutinin (HA) of H1N1 and H3N2 subtypes were selected. These MAbs were combined into three subtype-specific reagents, one each for pan-H1 (seasonal and 2009