A Use of 56-kDa Recombinant Protein of Karp Serotype in Serodiagnosis of Scrub Typhus by Enzyme-Linked Immunosorbent Assay in Thais.

Scrub typhus is a mite-borne disease caused by a Gram-negative obligately intracellular bacillus, . The disease is endemic in the Asia-Australia-Pacific region, including Thailand. Scrub typhus generally manifests as acute undifferentiated febrile fever along with myalgia, rash, and lymphadenopathy.

Evaluation of a genus-specific rGroEL IgM-ELISA and commercial ELISA kits during the course of leptospirosis in Thailand.

In the present study, we developed a genus-specific rGroEL IgM-ELISA assay for use in screening diagnosis of suspected leptospirosis among acute undifferentiated febrile illness patients during acute fever. The diagnostic accuracies of the rGroEL IgM-ELISA, commercial Panbio IgM-ELISA, and Virion-Serion Classic IgG-ELISA were evaluated using 133 Thai leptospirosis sera and 210 controls. Sensitivities were 91.

Antimicrobial Peptide Modifications against Clinically Isolated Antibiotic-Resistant .

Antimicrobial peptides are promising molecules to address the global antibiotic resistance problem, however, optimization to achieve favorable potency and safety is required. Here, a peptide-template modification approach was employed to design physicochemical variants based on net charge, hydrophobicity, enantiomer, and terminal group. All variants of the scorpion venom peptide BmKn-2 with amphipathic α-helical cationic structure exhibited an increased antibacterial potency when evaluated against multidrug-resistant isolates at a MIC range of 4-8 µM.

Genetic association study of interferon lambda 3, CD27, and human leukocyte antigen-DPB1 with dengue severity in Thailand.

Background: Dengue patients develop different disease severity ranging from mild (dengue fever [DF]) to severe forms (dengue hemorrhagic fever [DHF] and the fatal dengue shock syndrome [DSS]). Host genetics are considered to be one factor responsible for the severity of dengue outcomes. To identify genes associated with dengue severity that have not been studied yet, we performed genetic association analyses of interferon lambda 3 (IFNL3), CD27, and human leukocyte antigen-DPB1 (HLA-DPB1) genes in Thai dengue patients.

Interferon lambda 1 is associated with dengue severity in Thailand.

Objectives: Patients with dengue exhibit a range of symptoms from an acute febrile illness (dengue fever, DF), to dengue hemorrhagic fever (DHF), and to the most severe outcome, dengue shock syndrome (DSS). This study was performed to determine the host genetic factors responsible for dengue severity. Two single nucleotide polymorphisms (SNPs) of the interferon lambda 1 (IFNL1) gene (rs30461 and rs7247086) were analyzed for their association with dengue severity in a Thai population.

ELISA based on a recombinant Paragonimus heterotremus protein for serodiagnosis of human paragonimiasis in Thailand.

Background: Paragonimus heterotremus is the main causative agent of paragonimiasis in Thailand. In Western blot diagnostic assays for paragonimiasis, the 35 kDa band present in crude P. heterotremus somatic extracts represents one of the known diagnostic bands.

Immunodominance of LipL32 peptides revealed by leptospirosis sera and therapeutic monoclonal antibodies.

Background/purpose: Leptospirosis is a neglected zoonosis, imposing significant human and veterinary public health burdens. In this study, recombinant LipL32 and LipL32 middle domain of LipL32, and LipL32, and LipL32 of c-terminal LipL32 truncations were defined for immunodominance of the molecule during Leptospira infections revealed by leptospirosis sera.

Results: IgM-dominant was directed to highly surface accessible LipL32 and Lipl32.

MULTIPLE-LOCUS VARIABLE-NUMBER TANDEM REPEAT ANALYSIS OF BRUCELLA ISOLATES FROM THAILAND.

Brucellosis-induced abortion can result in significant economic loss to farm animals. Brucellosis can be transmitted to humans during slaughter of infected animals or via consumption of contaminated food products. Strain identification of Brucella isolates can reveal the route of transmission.

Cloning and expression of a 16-kDa recombinant protein from Angiostrongylus cantonensis for use in immunoblot diagnosis of human angiostrongyliasis.

Angistrongylus cantonensis is a zoonotic nematode parasite and causative agent of human angiostrongyliasis, which clinically presents as eosinophilic meningitis or meningoencephalitis. Diagnosis of the disease is problematic since parasitologic findings are infrequent, and infection determinations must be based on the clinical symptoms and serological tests with limited specificities and sensitivities. The aim of the present study was to identify and generate a novel recombinant protein from A.

Third-stage Gnathostoma spinigerum larva excretory secretory antigens modulate function of Fc gamma receptor I-mediated monocytes in peripheral blood mononuclear cell culture.

Background: Third (infective)-stage Gnathostoma spinigerum larvae (L3) mainly cause human gnathostomiasis. G. spinigerum L3 migrate throughout the subcutaneous tissues, vital organs, and central nervous system and can cause various pathogenesis including sudden death.

The Immunoreactive Exo-1,3-β-Glucanase from the Pathogenic Oomycete Pythium insidiosum Is Temperature Regulated and Exhibits Glycoside Hydrolase Activity.

The oomycete organism, Pythium insidiosum, is the etiologic agent of the life-threatening infectious disease called "pythiosis". Diagnosis and treatment of pythiosis is difficult and challenging. Novel methods for early diagnosis and effective treatment are urgently needed.

Molecular genotyping of human papillomavirus l1 gene in low-risk and high-risk populations in Bangkok.

Background: Human papillomavirus (HPV) infections in Thailand are a public health concern, but information on HPV infection in sex workers and men who have sex with men (MSM) is limited. The aim of this study was to measure the prevalence and genotype distribution of HPV among low- and high-risk, HIV-negative populations.

Methods: A total of 300 participants were categorized as general women, female sex workers, MSM, and MSM sex workers.

ELISA for brucellosis detection based on three Brucella recombinant proteins.

Control of brucellosis among farm animals, wildlife and humans require reliable diagnosis. Rose Bengal serological test (RBT) is based on lipopolysaccharide antigen of Brucella, which may cross react with other gram-negative bacteria and produce false positive result. Immunoreactive proteins, such as outer-membrane protein BP26, ribosome recycling factor protein CP24 and Brucella lumazine synthase (BLS), previously reported to be recognized by infected sheep sera, were selected for production of recombinant proteins for use in an ELISA in order to investigate immune response among goats and cows, in comparison with commercial RBT.

Cloning and application of recombinant dengue virus prM-M protein for serodiagnosis of dengue virus infection.

We studied the use of the precursor to the M structural protein (prM) found only on the surface of mature dengue virus as a target protein to detect dengue virus infection. Recombinant D2-16681 prM-M protein was constructed and tested for immunogenicity with dengue and Japanese encephalitis patient sera by Western blot analysis and indirect ELISA. The sensitivity and specificity of indirect ELISA were 48.

Genetic speciation of environmental Legionella isolates in Thailand.

Legionella-like organisms were isolated during 2003-2007 from various water resources by culturing on selective media of Wadowsky-Yee-Okuda agar. The 256 isolates were identified as belonging to the Legionella genus based on detection of 108 bp PCR product of the 5S rRNA gene, while the inclusion as Legionella pneumophila were confirmed by PCR detection of a specific mip gene region of 168 bp. The 50 isolates, identified as non-pneumophila, were then subjected to DNA tree analysis, based on mip gene of ~650 bp and rnpB genes product ranged from 304 to 354 bp.

Roles of partially purified antigens from Gnathostoma spinigerum larvae on antibody production by human B cell culture.

A 24 kDa protein from advanced third stage Gnathostoma spinigerum larvae (GsAL3) is used for gnathostomiasis serodiagnosis. This study investigated whether partially purified protein antigen (Ag) from GsAL3 (Gnath Ag), prepared by simple gel filtration chromatography, could be used for serodiagnosis. Using DNA microarray analysis, significant gene expression related to immunoreactivity was examined in peripheral blood mononuclear cells (PBMC) cocultured with Gnath Ag.

Accuracy of loop-mediated isothermal amplification for diagnosis of human leptospirosis in Thailand.

There is a lack of diagnostic tests for leptospirosis in technology-restricted settings. We developed loop-mediated isothermal amplification (LAMP) specific for the 16S ribosomal RNA gene (rrs) of pathogenic and intermediate group Leptospira species. The lower limit of detection was 10 genomic equivalents/reaction, and analytical specificity was high; we observed positive reactions for pathogenic/intermediate groups and negative reactions for non-pathogenic Leptospira species and other bacterial species.

Leptospirosis serodiagnosis by ELISA based on recombinant outer membrane protein.

The outer membrane protein LipL21, LipL32, LipL41 and Loa22 of Leptospira interrogans serovar Copenhageni were previously revealed by immunoproteomic analysis, using sera from acute phase infection in a guinea pig. The full-length DNA of each protein was then cloned from the same serovar and expressed in pRSET vector. The obtained molecular weight (MW) of recombinant proteins rLipL21, rLipL32 and rLoa22 were slightly higher than the MW predicted from nucleotide sequences of each inserted gene, while only the N-terminal half of rLipL41 was obtained.

Iso-electricfocusing of Bithynia snail antigens for IgG- and IgG(1-4)-ELISA detection of human opisthorchiasis.

Diagnosis of opisthorchiasis is confirmed by the presence of characteristic eggs and worms. However, misdiagnosis may occur in light infections, and also due to the morphological similarity of opisthorchid eggs to other species. A finding of specific immune mediators can help confirm infection.

Application of recombinant SMR-domain containing protein of angiostrongylus cantonensis in immunoblot diagnosis of human angiostrongyliasis.

The aim of this study was to find novel proteins expressed from an Angiostrongylus cantonensis adult female worm cDNA library for serodiagnosis of angiostrongyliasis. An immuno-dominant clone, fAC22, was identified by immunoscreening with pooled positive sera from proven angiostrongyliasis patients. The clone contained an open reading frame of 2,136 bp encoding a 80.

Blood stage Plasmodium falciparum antigens induce T cell independent immunoglobulin production via B cell activation factor of the TNF family (BAFF) pathway.

T independent (TI) antigens (Ags) activate monocytes to produce a cytokine, termed B cell activation factor (BAFF), involved in immunoglobulin (Ig) production. This study aimed to investigate whether the soluble schizont fraction of Plasmodium falciparum antigen (sPfAg) and hemozoin (HZ) could act as TI Ag to induce P. falciparum (Pf) specific Ig production via BAFF pathway.

Copro-DNA diagnosis of Opisthorchis viverrini and Haplorchis taichui infection in an endemic area of Lao PDR.

The utility of differential copro-DNA diagnosis using modified sample preparation steps of small liver and minute intestinal fluke infections was tested. Fecal samples containing parasite eggs were washed extensively with diluted detergent solution. Parasite eggs were concentrated by sedimentation and broken by microwaving before DNA extraction.

Effects of CYP2B6 G516T polymorphisms on plasma efavirenz and nevirapine levels when co-administered with rifampicin in HIV/TB co-infected Thai adults.

Background: Cytochrome P450 2B6 (CYP2B6) metabolizes efavirenz and nevirapine, the major core antiretroviral drugs for HIV in Thailand. Rifampicin, a critical component of tuberculosis (TB) therapy is a potent inducer of CYP enzyme activity. Polymorphisms of CYP2B6 and CYP3A4 are associated with altered activity of hepatic enzyme in the liver and pharmacokinetics resulting in treatment efficacy.

The 74-kilodalton immunodominant antigen of the pathogenic oomycete Pythium insidiosum is a putative exo-1,3-beta-glucanase.

The oomycetous, fungus-like, aquatic organism Pythium insidiosum is the causative agent of pythiosis, a life-threatening infectious disease of humans and animals living in tropical and subtropical areas of the world. Common sites of infection are the arteries, eyes, cutaneous/subcutaneous tissues, and gastrointestinal tract. Diagnosis of pythiosis is time-consuming and difficult.

IL4 gene polymorphism and previous malaria experiences manipulate anti-Plasmodium falciparum antibody isotype profiles in complicated and uncomplicated malaria.

Background: The IL4-590 gene polymorphism has been shown to be associated with elevated levels of anti-Plasmodium falciparum IgG antibodies and parasite intensity in the malaria protected Fulani of West Africa. This study aimed to investigate the possible impact of IL4-590C/T polymorphism on anti-P. falciparum IgG subclasses and IgE antibodies levels and the alteration of malaria severity in complicated and uncomplicated malaria patients with or without previous malaria experiences.