Evaluation of a Commercial Direct Fluorescent-Antibody Assay for Human Metapneumovirus in Respiratory Specimens

Aim. To determine the frequency of detection of conjunctivalC. trachomatis(CT),M. hominis(MH), andU. urealyticum(UU) infections in young adults with dry eye disease (DED), since these infections may potentially produce the chronic subclinical inflammation characteristic of DED.Materials and Methods. The study included subjects of 25–45 years of age, divided into the DED (n=114) and nondry eye control (n=98) groups, with the diagnosis based on self-reported complaints, biomicroscopy, the Schirmer I test, and break-up time. All patients had conjunctival scrapings taken to detect CT, MH, and UU with direct fluorescent-antibody assay kits.Results. At least one of the three microorganisms was found in 87.7% of the DED patients versus 8.2% of the controls. Of all the DED patients, 63.2%, 50.8%, and 42.1% were found to be infected with CT, MH, and UU, respectively. Multiple pathogens were identified in 65% of the DED patients found to be infected. CT infection was detected in 6.1% of the controls.Conclusion.C. trachomatis,M. hominis, andU. urealyticumwere detected with high frequency in the conjunctiva of young adults with DED and may be an important risk factor for DED in them.

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Comparison of the performance of direct fluorescent antibody staining, a point-of-care rapid antigen test and virus isolation with that of RT-PCR for the detection of novel 2009 influenza A (H1N1) virus in respiratory specimens

Journal of Medical Microbiology ◽

10.1099/jmm.0.017244-0 ◽

2010 ◽

Vol 59 (6) ◽

pp. 713-717 ◽

Cited By ~ 39

Author(s):

Tina Ganzenmueller ◽

Jeanette Kluba ◽

Birgit Hilfrich ◽

Wolfram Puppe ◽

Willem Verhagen ◽

...

Keyword(s):

Rapid Detection ◽

Influenza A ◽

Virus Isolation ◽

H1n1 Virus ◽

Point Of Care ◽

Fluorescent Antibody ◽

Rt Pcr ◽

Influenza A H1n1 ◽

Direct Fluorescent Antibody ◽

Respiratory Specimens

Although infections with the novel pandemic 2009 influenza A (H1N1) virus (A/H1N1/2009) appeared to be relatively mild during the first summer of circulation (‘off season’), there has been significant morbidity and hospitalization and several fatal cases. Thus, rapid detection of A/H1N1/2009 is crucial for efficient treatment and infection control measures. In contrast to seasonal influenza, where point-of-care (POC) rapid antigen tests and direct fluorescent antibody (DFA) staining ensure rapid detection, diagnosis of A/H1N1/2009 has so far been based on RT-PCR. This study retrospectively compared the performance of the Quidel QuickVue POC test, DFA staining and virus isolation with that of RT-PCR for A/H1N1/2009 detection in 526 respiratory specimens collected during the first wave of the outbreak from May to September 2009. A/H1N1/2009 was detected in 9.1 % (48/526) of samples. One hundred and thirty-seven of the A/H1N1/2009 PCR-negative samples were additionally tested using a RealAccurate Respiratory RT-PCR panel, revealing other respiratory viruses (mainly entero/rhino- and adenoviruses) in 42.3 % (58/137). All methods analysed detected A/H1N1/2009 with excellent specificity but different sensitivities (POC test: 18.2 %; DFA staining: 38.7 %; virus isolation: 45.7 %). Therefore, the POC test was not suitable for diagnosis, detecting A/H1N1/2009 only if present in high concentrations (corresponding median C t value=19.0; range=16.5–21.4). DFA staining was also able to detect A/H1N1/2009 in specimens with a lower virus concentration (median C t value=24.0; range=16.5–29.8). Virus isolation, which was positive after a median time of 7.5 days, was too time-consuming. In summary, DFA staining is superior to POC testing and may be appropriate for patients expected to have a rather high level of virus replication. Nevertheless, in DFA-negative specimens, A/H1N1/2009 should be excluded by RT-PCR.

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Evaluation of Shell Vial Cell Culture Technique for the Detection of Bovine Coronavirus

Journal of Veterinary Diagnostic Investigation ◽

10.1177/104063879500700301 ◽

1995 ◽

Vol 7 (3) ◽

pp. 301-304 ◽

Cited By ~ 6

Author(s):

Rafique A. Tahir ◽

Kern A. Pomeroy ◽

Sagar M. Goyal

Keyword(s):

Tumor Cells ◽

Fluorescent Antibody ◽

Rectal Tumor ◽

Antibody Assay ◽

Electron Microscopic ◽

Bovine Coronavirus ◽

Shell Vial ◽

Extracellular Virus ◽

Transmission Electron ◽

Direct Fluorescent Antibody

The effect of blind passage and centrifugation on the isolation of bovine coronavirus in human rectal tumor cells cultured in shell vials was investigated. A total of 68 fecal samples known to be positive for bovine coronavirus by transmission electron microscopic (TEM) examination were used. The samples were centrifuged onto human rectal tumor cell monolayers and incubated in the presence of trypsin. The growth of bovine coronavirus in infected cells was demonstrated by fluorescent antibody staining, and the extracellular virus was detected and confirmed by hemagglutination and hemagglutination-inhibition tests, respectively. Of the 68 TEM-positive samples, 51 (75%), 58 (85%), and 61 (90%) grew in shell vial cell cultures at first, second, and third passages, respectively. Of the 51 cultures positive on first passage, 19 were examined by TEM; 18 of these were positive for bovine coronavirus. The shell vial technique was also compared with direct detection of bovine coronavirus by staining cryostat sections of infected tissues in a direct fluorescent antibody assay. The results of direct fluorescent antibody assay were available for 54 of the 68 samples, of which 53 (98%) and 43 (80%) were positive by shell vial technique and direct fluorescent antibody assay, respectively. For identification of bovine coronavirus, shell vials using human rectal tumor cells in the presence of trypsin is more sensitive than direct fluorescent antibody assay but is relatively less sensitive than transmission electron microscopy.

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