Preeda Lertwatcharasarakul

Developing an Indirect ELISA Based on Recombinant Hexon Protein for Serological Detection of Inclusion Body Hepatitis in Chickens

ABSTRACT Fowl adenovirus (FAdv) serotype 2 causes inclusion body hepatitis (IBH) disease which adversely affects the broiler industry in Thailand. We developed an indirect ELISA based on the recombinant hexon protein produced by E. coli. The recombinant hexon protein was tested with sera, in both infected and noninfected chickens. The recombinant hexon protein was standardized with an antigen concentration of 3.75 µg/ml and test sera. The intra- and inter-assays were repeatable. The cutoff value from TG-ROC curve analysis was 0.106. The specificity and sensitivity were 80 and 80%, respectively. The correlation coefficient (r) of absorbance values from this ELISA compared with the serum neutralization test was 0.76. This ELISA might be helpful for IBH diagnosis and surveillance.

FIRST REPORTED CASE OF ELEPHANT ENDOTHELIOTROPIC HERPES VIRUS INFECTION IN LAOS

Abstract:  The elephant endotheliotropic herpesvirus (EEHV) is now recognized as one of the main causes of death of young Asian elephants (Elephas maximus) in North American zoos. Its impact in wild and domestic elephant populations in Asia is not clearly understood. This article describes the first case of EEHV infection in Lao Peoples Democratic Republic of a 2.5-yr-old domestic male Asian elephant. Clinical signs and pathological findings reported here are consistent with previous infections in Asian elephant calves. Phylogenetic analyses showed 100% homology with other EEHV-1A strains identified in Asia, Europe, and North America. Contamination of the molecular assays was ruled out, because the DNA polymerase sequence identified in this study differed from the positive control by two base pairs.

Molecular characterization of Anaplasma platys in a domestic cat from Thailand

A 5-year-old female cat was presented at Kamphaengsaen Animal Hospital for a complication of jaundice. Haematology revealed mild non-regenerative anaemia, lymphopenia, thrombocytopenia, hyper-proteinaemia and icteric plasma. The inclusion bodies in the platelets were detected in a stained blood smear. Partial sequences of the 16S rRNA gene from the isolate indicated that it had the closest relation to Anaplasma platys sequences from many dogs in Thailand and those obtained from GenBank. This is the first report of Anaplasma platys in a naturally infected domestic cat from Thailand.

Cell penetrable human scFv specific to middle domain of matrix protein-1 protects mice from lethal influenza.

A new anti-influenza remedy that can tolerate the virus antigenic variation is needed. Influenza virus matrix protein-1 (M1) is highly conserved and pivotal for the virus replication cycle: virus uncoating, assembly and budding. An agent that blocks the M1 functions should be an effective anti-influenza agent. In this study, human scFv that bound to recombinant M1 middle domain (MD) and native M1 of A/H5N1 was produced. Phage mimotope search and computerized molecular docking revealed that the scFv bound to the MD conformational epitope formed by juxtaposed helices 7 and 9 of the M1. The scFv was linked molecularly to a cell penetrable peptide, penetratin (PEN). The PEN-scFv (transbody), when used to treat the cells pre-infected with the heterologous clade/subclade A/H5N1 reduced the viral mRNA intracellularly and in the cell culture fluids. The transbody mitigated symptom severity and lung histopathology of the H5N1 infected mice and caused reduction of virus antigen in the tissues as well as extricated the animals from the lethal challenge in a dose dependent manner. The transbody specific to the M1 MD, either alone or in combination with the cognate human scFvs specific to other influenza virus proteins, should be an effective, safe and mutation tolerable anti-influenza agent.

Haemoproteus in barn and collared scops owls from Thailand

The barn owl (BO) and the collared scops owl (CSO) are common nocturnal raptors throughout Thailand. Blood samples from 23 adult BOs and 14 CSOs were collected and processed for complete blood cell counts and parasite morphological examinations. Two Haemoproteus-positive samples were processed for ultrastructural observation. Polymerase chain reaction (PCR) analysis for a partial cytochrome b gene (cytb) from Haemoproteus was performed in all samples. Haemoproteus presence detected by light microscopy was lower than that detected by PCR (30.4% and 34.8%, respectively, in BO; and 50.0% and 78.6%, respectively, in CSO). Comparative hematology revealed that Haemoproteus-positive BOs had higher mean cell hemoglobin concentration, total leukocyte, absolute heterophil, basophil, and monocyte counts than Haemoproteus-negative BOs, but no significant differences between Haemoproteus-negative and -positive CSOs. Monocyte ultrastructure analysis revealed a role in the elimination of gametocytes. Morphologically, the Haemoproteus in 3 BOs and 6 CSOs were identified as H. noctuae, while that in 1 CSO was identified as H. syrnii. Phylogenetic analysis indicated the Haemoproteus spp. in 8 BOs and 7 CSOs were not closely related to H. noctuae or H. syrnii, and the cytb of 2 CSOs was that of H. syrnii. These results should be useful for study of Haemoproteus.

Molecular and phylogenetic characterization of bovine coronavirus virus isolated from dairy cattle in Central Region, Thailand

Bovine coronavirus (BCoV) is involved mainly in enteric infections in cattle. This study reports the first molecular detection of BCoV in a diarrhea outbreak in dairy cows in the Central Region, Thailand. BCoV was molecularly detected from bloody diarrheic cattle feces by using nested PCR. Agarose gel electrophoresis of three diarrheic fecal samples yielded from the 25 samples desired amplicons that were 488 base pairs and sequencing substantiated that have BCoV. The sequence alignment indicated that nucleotide and amino acid sequences, the three TWD isolated in Thailand, were more quite homologous to each other (amino acid at position 39 of TWD1, TWD3 was proline, but TWD2 was serine) and closely related to OK-0514-3strain (virulent respiratory strain; RBCoV).The amino acid sequencing identities among TWD1, TWD2,TWD3, and OK-0514-3 strain were 96.0 to 96.6%, those at which T3I, H65N, D87G, H127Y, andQ136R were changed. In addition, the phylogenetic tree of the hypervariable region S1subunit spike glycoprotein BCoV gene was composed of three major clades by using the 54 sequences generated and showed that the evolutionally distance, TWD1, TWD2, and TWD3 were the isolated group together and most similar to OK-0514-3 strain (98.2 to 98.5% similarity). Further study will develop ELISA assay for serologic detection of winter dysentery disease.