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Virus Culture (virus + culture)
Selected AbstractsAn evaluation of current diagnostic tests for the detection of infectious salmon anaemia virus (ISAV) following experimental water-borne infection of Atlantic salmon, Salmo salar L.JOURNAL OF FISH DISEASES, Issue 3 2003M Snow Abstract Four commonly used diagnostic tests [reverse transcription polymerase chain reaction (RT-PCR), indirect fluorescent antibody test (IFAT), virus culture and light microscopy] were evaluated for their ability to detect infectious salmon anaemia virus (ISAV) or tissue pathology following experimental infection of Atlantic salmon. Fish were infected with ISAV by water-borne exposure which mimics the route of natural infection. Forty-five per cent of pre-clinical fish tested yielded positive results by RT-PCR for at least one of the organs tested (kidney, heart, gill, liver, blood). No significant difference was detected between organs in the number or time of first occurrence of positive result. Virus culture identified a total of 14% of pre-clinical fish as ISAV-infected. The presence of ISAV in heart tissue was particularly notable (13% of fish sampled) as was the inability to culture virus from spleen tissue. In the case of IFAT, 15% of fish sampled were positive, although tissue other than kidney proved unsuitable for use in this method. Only limited ISAV-specific pathology was detectable by histological examination of fish prior to the onset of clinical disease. These findings reveal important information regarding the optimal choice of both tissue sample and diagnostic test for the routine diagnosis of ISAV. [source] Microchip, reverse transcription-polymerase chain reaction and culture methods to detect enterovirus infection in pediatric patientsPEDIATRICS INTERNATIONAL, Issue 1 2006LON-YEN TSAO Abstract Background: Enterovirus infection usually presents with mild and self-limited illness in children. However, Enterovirus type 71 can be characterized by neurotropism and may cause severe illness or even sudden death. Early detection of the virus will allow a physician to provide intensive or aggressive intervention. The purpose of the present study was to compare sensitivity of two innovative laboratory methods, that is, the DR.EV microchip method (DR. Chip Biotechnology, Shin-Tsu, Taiwan) and the reverse transcription-polymerase chain reaction (RT-PCR) method following conventional virus culture in detecting enterovirus infection in pediatric patients with herpangina or hand,foot,mouth disease. Methods: A total of 87 children (age range: 1,8 years) were enrolled because of typical clinical findings of herpangina and hand,foot,mouth disease. Two hundred children selected after a careful clinical history review and physical examinations, were included as controls. All of these children had at least throat swab and rectal swab specimens taken and tested for evidence of enterovirus infection by microchip, RT-PCR and virus culture methods. In addition, 21 patients also had cerebrospinal fluid (CSF) specimens taken to test for possible central nervous system involvement. Result: The test results obtained from the 200 healthy kindergarten children were all negative for enteroviral infection by these three methods. Among the 87 test patients, the positive rates for throat swab, rectal swab and CSF by DR.EV chip, RT-PCR and virus culture were 71%, 68%, and 45% (throat swab); 66%, 61%, and 33% (rectal swab); and 52%, 29%, and 5% (CSF), respectively. There was no significant difference in the positive rates between the DR.EV chip and the RT-PCR methods (P > 0.1) on all types of specimens. However, statistically significant differences in positive rates were noted between the DR.EV chip and the conventional virus culture methods on all types of specimens (P < 0.001). Sensitivity of the microchip, RT-PCR and virus culture methods, was 82%, 72%, and 53%, respectively. Conclusion: The DR.EV chip method yielded a statistically higher positive rate and faster test results than the conventional viral culture method. [source] Australian surveillance for avian influenza viruses in wild birds between July 2005 and June 2007AUSTRALIAN VETERINARY JOURNAL, Issue 7 2009L Haynes Objective To identify and gain an understanding of the influenza viruses circulating in wild birds in Australia. Design A total of 16,303 swabs and 3782 blood samples were collected and analysed for avian influenza (AI) viruses from 16,420 wild birds in Australia between July 2005 and June 2007. Anseriformes and Charadriiformes were primarily targeted. Procedures Cloacal, oropharyngeal and faecal (environmental) swabs were tested using polymerase chain reaction (PCR) for the AI type A matrix gene. Positive samples underwent virus culture and subtyping. Serum samples were analysed using a blocking enzyme-linked immunosorbent assay for influenza A virus nucleoprotein. Results No highly pathogenic AI viruses were identified. However, 164 PCR tests were positive for the AI type A matrix gene, 46 of which were identified to subtype. A total of five viruses were isolated, three of which had a corresponding positive PCR and subtype identification (H3N8, H4N6, H7N6). Low pathogenic AI H5 and/or H7 was present in wild birds in New South Wales, Tasmania, Victoria and Western Australia. Antibodies to influenza A were also detected in 15.0% of the birds sampled. Conclusions Although low pathogenic AI virus subtypes are currently circulating in Australia, their prevalence is low (1.0% positive PCR). Surveillance activities for AI in wild birds should be continued to provide further epidemiological information about circulating viruses and to identify any changes in subtype prevalence. [source] | ||||||||||