ABSTRACT
In the present contribution virions of five different virus species, namely Varicella-zoster virus, Porcine teschovirus, Tobacco mosaic virus, Coliphage M13 and Enterobacteria phage PsP3, are investigated using atomic force microscopy (AFM). From the resulting height images quantitative features like maximal height, area and volume of the viruses could be extracted and compared to reference values. Subsequently, these features were accompanied by image moments, which quantify the morphology of the virions. Both types of features could be utilized for an automatic discrimination of the five virus species. The accuracy of this classification model was 96.8%. Thus, a virus detection on a single-particle level using AFM images is possible. Due to the application of advanced image analysis the morphology could be quantified and used for further analysis. Here, an automatic recognition by means of a classification model could be achieved in a reliable and objective manner.
Subject(s)
Image Processing, Computer-Assisted , Microscopy, Atomic Force , Virion/isolation & purification , Herpesvirus 3, Human/isolation & purification , Herpesvirus 3, Human/ultrastructure , Teschovirus/isolation & purification , Teschovirus/ultrastructure , Tobacco Mosaic Virus/isolation & purification , Tobacco Mosaic Virus/ultrastructure , Virion/ultrastructureABSTRACT
In February and March 2009, approximately 1,500 backyard pigs of variable age became sick, and approximately 700 of them died or were euthanized in the Lower Artibonite Valley and the Lower Plateau of the Republic of Haiti. The main clinical sign was posterior ataxia followed by paresis and/or paralysis on the second or third day of illness. No gross lesions were observed at postmortem examinations. The morbidity and mortality were approximately 60% and 40%, respectively. Diagnostic samples (whole blood, brain, tonsil, lymph nodes, spleen, and lung) were negative for Classical swine fever virus and African swine fever virus. Porcine teschovirus type 1 was detected by reverse transcription polymerase chain reactions in brain samples. Results of virus isolation, electron microscopy of virus particles, histopathological analysis on brain tissues, nucleic acid sequencing, and phylogenetic analysis of the viral isolate supported the diagnosis of teschovirus encephalomyelitis. The outbreak of the disease in Haiti is the first appearance of the severe form of teschovirus encephalomyelitis in the Americas. This disease poses a potential threat to the swine industries in other Caribbean countries, as well as to Central and North American countries.
Subject(s)
Encephalomyelitis/veterinary , Picornaviridae Infections/veterinary , Swine Diseases/virology , Teschovirus/isolation & purification , Animals , Antibodies, Viral/analysis , Disease Outbreaks/veterinary , Encephalomyelitis/diagnosis , Encephalomyelitis/epidemiology , Encephalomyelitis/virology , Haiti/epidemiology , Histocytochemistry/veterinary , Microscopy, Electron/veterinary , Phylogeny , Picornaviridae Infections/diagnosis , Picornaviridae Infections/epidemiology , Picornaviridae Infections/virology , RNA, Viral/chemistry , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction/veterinary , Sequence Analysis, DNA , Swine , Swine Diseases/epidemiology , Teschovirus/genetics , Teschovirus/ultrastructureABSTRACT
Porcine teschovirus 1 (PTV-1) (Swine/CH/IMH/03) was isolated from piglets in a farm in Inner Mongolia Province, P.R. China. It was confirmed by electron microscopy, RT-PCR, and sequencing. Comparison of the sequences of the amino acid and nucleotides and phylogenetic analysis of the polyprotein showed that PTV Swine/CH/IMH/03 strain is PTV-1. The isolated virus has closest relationship with Talfan strain, they shared 98.9% and 99.5% homology of amino acids and nucleotides, respectively, in the ORF of polyprotein. To our knowledge, this is the first report about isolation and identification of a PTV in China.
