Comparative assessment of immunochromatographic test kits using somatic antigens from adult Opisthorchis viverrini and IgG and IgG4 conjugates for serodiagnosis of human opisthorchiasis.

Chronic infections of humans with Opisthorchis viverrini and Clonorchis sinensis spanning decades may lead to life-threatening pathology prior to cholangiocarcinoma (CCA), which usually has a poor prognosis. Serological tools can support the parasitological examination in clinical diagnosis and support screening for risk of CCA. We developed novel immunochromatographic test kits using a soluble, somatic tissue extract of adult O. viverrini worms as an antigen and colloidal gold-labeled conjugates of IgG and IgG4 antibodies, and evaluated the diagnostic values of both the OvSO-IgG and OvSO-IgG4 kits. For diagnosis of human opisthorchiasis individually, the diagnostic sensitivity, specificity, and positive and negative predictive values with 95% confidence intervals in the OvSO-IgG kit were 86.6% (78.9-92.3), 89.5% (84.2-93.5), 82.9% (74.8-89.2), and 91.9% (87.0-95.4), respectively, while the 75% (65.9-82.7), 98.4% (95.5-99.7), 96.6% (90.3-99.3), and 87% (81.7-91.2), respectively, for the OvSO-IgG4 kit at the prevalence of infection of 37.1%. Twenty-three (76.7%) and 14 (46.7%) of 30 clonorchiasis sera showed positive reactivity with the OvSO-IgG and OvSO-IgG4 kits, respectively. There was 84.1% (κ-value = 0.649) concordance between the two kits, which was statistically significant (p < 0.001). Both ICT kits can be employed as quick and easy point-of-care diagnostic tools, and hence, the OvSO-IgG and OvSO-IgG4 kits can support expanded capacity for clinical diagnosis of human opisthorchiasis and clonorchiasis. These kits may find utility in large-scale surveys in endemic areas where there are limited sophisticated medical facilities or capacity.

Comparison of point-of-care test and enzyme-linked immunosorbent assay for detection of immunoglobulin G antibodies in the diagnosis of human schistosomiasis japonica.

OBJECTIVE: Schistosomiasis japonica is an important helminthic disease in Asia. Sensitive and accurate diagnostic tools are indispensable for clinical diagnosis, screening infection and monitoring its control. In this study, we developed an immunochromatographic test (Sj-ICT) to detect anti-Schistosoma japonicum immunoglobulin G antibodies in human sera. METHODS: Somatic extract from adult S. japonicum was used as an antigen. The Sj-ICT was developed and optimized as a point-of-care test. All 214 human serum samples were evaluated for diagnostic usefulness and comparison with an enzyme-linked immunosorbent assay (ELISA). RESULTS: The diagnostic sensitivity, specificity, positive and negative predictive values, and accuracy of the Sj-ICT were 90.8%, 87.9%, 86.4%, 91.9% and 89.3%, respectively. For ELISA the values were respectively 91.8%, 87.9%, 86.5%, 92.7% and 89.7%. The concordance between both methods was 86.4 % (Cohen's kappa value = 0.729). CONCLUSIONS: The immunochromatographic test kit developed can support clinical diagnosis and large-scale surveys in endemic areas without requiring additional facilities or ancillary supplies.

High prevalence of opisthorchiasis in rural populations from Khammouane Province, central Lao PDR: serological screening using total IgG- and IgG4-based ELISA.

BACKGROUND: Human opisthorchiasis, caused by Opisthorchis viverrini, is a public health problem in Southeast Asia and a major risk factor for cholangiocarcinoma. In Lao PDR, seroprevalence and the relationship between the number of O. viverrini eggs in infected people and specific antibody responses are still unknown. We evaluated and compared parasitological and serological screening methods in the community in an endemic area of opisthorchiasis in Lao PDR. METHODS: Seroprevalence of O. viverrini-specific total IgG and IgG4 antibodies and their relationships with O. viverrini egg intensities were evaluated in Khammouane Province, central Lao PDR, using ELISA and a modified formalin ethyl-acetate concentration technique (FECT). RESULTS: FECT stool examination revealed O. viverrini eggs in 70.3% (90/128) of individuals (95% CI 61.6 to 78.1%) while ELISA (based on total IgG and on IgG4 antibodies to O. viverrini) found 98.4% (95% CI 94.5 to 99.8%) and 89.8% (95% CI 83.3 to 94.5%) of sera, respectively. There was a positive and significant correlation between numbers of O. viverrini eggs per gram and levels of both IgG (R2=0.168, p<0.001) and IgG4 (R2=0.219, p<0.001) antibodies. CONCLUSIONS: A high prevalence of human opisthorchiasis in Lao PDR was found using a new platform, serological screening in the community. This points to a need for sustainable control of this liver fluke infection.

Investigating the microbiota of fermented fish products (Pla-ra) from different communities of northeastern Thailand.

DNA-sequencing was performed on the V3-V4 regions of 16S rRNA genes to investigate the microbial diversity of five samples of fermented freshwater fish (pla-ra) from three provinces in northeastern Thailand. The samples had salt concentrations ranging from 7 to 10%, pH values from 4.83 to 7.15, and D-/L-lactic acid concentrations of 90 to 450 mg/l. A total of 598 operational taxonomic units were annotated at various taxonomic ranks based on the SILVA Database. The lactic-acid and halophilic genera Tetragenococcus, Halanaerobium and Lactobacillus were among the dominant taxa of bacteria. The top 20 non-redundant taxa were considered in more detail. In two pla-ra samples, Tetragenococcus muriaticus was commonly identified. Halanaerobium fermentans was the most abundant species in a third sample and co-dominant in another sample. Lactobacillus rennini was dominant in the pla-ra sample from Roi Et Province. Additionally, other beneficial bacteria were detected including Staphylococcus nepalensis, Lactobacillus sakei, Lactobacillus pentosus, Weissella confusa, and Bifidobacterium bifidum. Differences between samples may be due to use of different raw materials, salt concentrations, recipes, processes and fermentation periods. The microbial communities in pla-ra provide a better understanding of the production outcomes of traditional products. Further optimization of the fermentation process, for example by using dominant bacterial taxa in starter cultures, may improve processes of food fermentation, food quality and flavor control, providing useful guidelines for industrial applications.

Effectiveness of Strongyloides Recombinant IgG Immunoreactive Antigen in Detecting IgG and IgG4 Subclass Antibodies for Diagnosis of Human Strongyloidiasis Using Rapid Immunochromatographic Tests.

Human strongyloidiasis is an important soil-transmitted helminthiasis that affects millions worldwide and can develop into fatal systemic strongyloidiasis in immunosuppressed patients. We have developed two new rapid and simple-to-use immunochromatographic test (ICT) kits for rapid serodiagnosis that support stool examination for clinical diagnosis. Strongyloides stercoralis recombinant IgG immunoreactive antigen (GenBank: AAB97359.1; rSsIR-based ICT kit) was used for detection of IgG and IgG4 antibodies. The diagnostic efficacy of both kits was evaluated using human serum samples from strongyloidiasis patients, healthy individuals, and those with other parasitosis. At a prevalence of infection of 36.4%, the diagnostic sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of the rSsIR-based IgG ICT kit were 91.7%, 83.8%, 76.4%, 94.6%, and 86.7%, respectively, and those of the rSsIR-based IgG4 ICT kit were 78.3%, 84.8%, 74.6%, 87.3%, and 82.4% respectively. The concordance between the two kits was 89.7%. The recombinant antigen can be produced to an unlimited extent and the kits can be used as point-of-care diagnostic tools and in large-scale surveys in endemic areas throughout tropical regions without necessitating additional facilities or ancillary supplies.

Development and Characterization of an Anti-Acne Gel Containing Siamese Crocodile (Crocodylus siamensis) Leukocyte Extract.

Leukocytes are reportedly the first line of the innate immune defense and essential for the control of common bacterial infections. Therefore, in this work, the antibacterial activity of crocodile leukocyte extract against Propionibacterium acnes was evaluated, and we also characterized the related activity of skin infection. The leukocyte extract showed the minimum inhibitory concentration to be 100 µg/ml to P. acnes. SEM imaging demonstrated that the leukocyte extract adversely affected P. acnes cell permeability in a concentration-dependent manner. Furthermore, the crocodile leukocyte extract could significantly reduce proinflammatory markers and decrease inflammatory signs in infected mouse ears. The crude leukocyte extract was further purified using FPLC and RP-HPLC. The resulting fraction F5 was indicated as the anti-acne peptide-containing fraction. The molecular mass of the peptide contained in F5 was calculated to be 4,790.5 Da. N-Terminal sequencing revealed the amino acid sequence as GPEPVPAIYQ, which displays similarities to immunoglobulin A and leucine-rich repeat neuronal protein. This is the first reported amino acid sequence of a crocodile leukocyte extract that possesses anti-acne activity. To attempt to use it in a prototype cosmetic, an anti-acne gel containing crude crocodile leukocyte extract was formulated, resulting in seven gel formulations (G1, G2, G3, G4, G5, G6, and G7). The formulations G5, G6, and G7 exhibited 2-fold higher anti-acne activity than G1-G4. Investigation of accelerating stability studies of anti-acne gel formulations G5, G6, and G7 demonstrated that a low storage temperature (4°C) is suitable for maintaining the physical properties and biological activity of the anti-acne gel products.