• Journal of Microbiology and Biotechnology
• /
• v.24 no.12
• /
• pp.1728-1735
• /
• 2014

Scrub typhus, caused by infection with Orientia tsutsugamushi, is a mite-borne zoonotic disease endemic to the Asian-Pacific region. In Korea, the incidence of this disease has increased with climate changes, and over 10,000 cases of infection were reported in 2013. Although this infection is treatable with antibiotics such as doxycycline and azithromycin, an effective prophylactic vaccine against O. tsutsugamushi would be more desirable for preventing scrub typhus in endemic areas. In this study, we investigated the 56-kDa type-specific antigen (TSA56), which is a major outer membrane protein of O. tsutsugamushi, as a vaccine candidate. Intranasal immunization of recombinant TSA56 (rec56) induced a higher level of TSA56-specific IgG than that induced by intramuscular immunization of tsa56-expressing DNA (p56). Both types of immunization induced a cell-mediated immune response to TSA56, as demonstrated by the splenic cell proliferation assay. Mice immunized with p56, followed by rec56 plus heat-labile enterotoxin B subunit from E. coli, had a stronger protection from a homologous challenge with the O. tsutsugamushi Boryong strain than with other combinations. Our preliminary results suggest that an effective human vaccine for scrub typhus can include either recombinant TSA56 protein or tsa56-expressing DNA, and provide the basis for further studies to optimize vaccine performance using additional antigens or different adjuvants.

• Molecules and Cells
• /
• v.45 no.10
• /
• pp.702-717
• /
• 2022

Hepatitis C virus (HCV) infection can lead to chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV employs diverse strategies to evade host antiviral innate immune responses to mediate a persistent infection. In the present study, we show that nonstructural protein 5A (NS5A) interacts with an NF-κB inhibitor immunomodulatory kinase, IKKε, and subsequently downregulates beta interferon (IFN-β) promoter activity. We further demonstrate that NS5A inhibits DDX3-mediated IKKε and interferon regulatory factor 3 (IRF3) phosphorylation. We also note that hyperphosphorylation of NS5A mediates protein interplay between NS5A and IKKε, thereby contributing to NS5A mediated modulation of IFN-β signaling. Lastly, NS5A inhibits IKKε-dependent p65 phosphorylation and NF-κB activation. Based on these findings, we propose NS5A as a novel regulator of IFN signaling events, specifically by inhibiting IKKε downstream signaling cascades through its interaction with IKKε. Taken together, these data suggest an additional mechanistic means by which HCV modulates host antiviral innate immune responses to promote persistent viral infection.

• The Korean Nurse
• /
• v.5 no.5 s.25
• /
• pp.23-29
• /
• 1966

• Asian Pacific Journal of Cancer Prevention
• /
• v.16 no.18
• /
• pp.8085-8091
• /
• 2016

Human papillomavirus is a virus that is distributed worldwide, and persistent infection with high-risk genotypes (HR-HPV) is considered the most important factor for the development of squamous cell cervical carcinoma (SCC). However, by itself, it is not sufficient, and other factors may contribute to the onset and progression of lesions. For example, infection with other sexually transmitted diseases such as human immunodeficiency virus (HIV) may be a factor. Previous studies have shown the relationship between HPV infection and SCC development among HIV-infected women in many regions of the world, with great emphasis on low- and middle-income countries (LMICs). Brazil is considered a LMIC and has great disparities across different regions. The purpose of this review was to highlight the current knowledge about HPV infection and cervical abnormalities in HIV+ women in Brazil because this country is an ideal setting to evaluate HIV impact on SCC development and serves as model of LMICs and low-resource settings.

• Asian Pacific Journal of Cancer Prevention
• /
• v.17 no.3
• /
• pp.1589-1593
• /
• 2016

Opisthorchis viverrini (OV) liver flukes are common parasites found in central and southern Laos and constitute a major public health problem in the country. Laos people continue to have the habit of extensively consuming raw or half-cooked fish which are intermediate hosts. This study aimed to determine the prevalence and factors associated with OV infection in the population of Thakek district, Khammouane Province. This cross-sectional analytic study covered 237 subjects who filled out structured questionnaires. Fecal examination for OV infection was performed by Kato's thick smear method. Data analysis was carried out using STATA Version 10.0. Multiple logistic regression was applied. The results showed that the infection rate of OV was 54.8%. Factors associated with OV infections were gender, a habit of defecation in fields and raw fish (goi bplaa dip) consumption. Opisthorchiasis and associated cholangiocarcinoma development thus appear to remain as important concerns in Laos.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.6169-6173
• /
• 2012

Infection by human papillomavirus (HPV) is one of common sexually transmitted diseases leading to cervical cancer. Evaluation of parental knowledge and attitudes toward HPV were aims of present study to provide an appropriate method to decrease burden of this infection on society. During this study, 358 parents were assessed for knowledge about HPV and its related disorders. Some 76% of parents had no information about HPV infection and among the informed parents 36% had obtained their information via internet and others from studying medical resources. The average score of mothers information about HPV infection was higher than that of fathers, and also educational level and age had significant impact on knowledge of parents about HPV. Parent knowledge about the hazards of HPV was higher than their knowledge about modes of transmission. Lack of awareness about HPV infection was high in this study, underlining the urgency of education among all adult people in our society.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.8
• /
• pp.3657-3661
• /
• 2012

HBV infection is contagious and may be transmitted vertically or horizontally by blood products and body secretions. Over 50% of Iranian carriers have contracted the infection prenatally, making this the most likely route of transmission of HBV in Iran. This study assesses the resistance to Lamivudine in patients with chronic hepatitis B infection using a new ZNA probe Real Time PCR method. To evaluate the effectiveness of Lamivudine therapy for chronic hepatitis B infection, a study was conducted on 70 patients (63 men and 7women), who had received the drug first line. All patients were tested for the presence of HBsAg and HBeAg, the serum ALT level and the HBV DNA load before and after treatment. In all samples resistance to Lamivudine was tested with the ZNA Probe. Our results showed that ZNA Probe Real Time PCR method could detect wild type,YMDD, and its mutants, tyrosine-isoleucine-aspartate-aspartate and tyrosine-valine-aspartate-Aspartate. Among an estimated seventy patients with chronic hepatitis B infection, 18 (25.7%) were resistant to lamivudine. Only one patient was negative for presence of HBS-Ag (5.6%) and two patients were negative for HBe-Ag (11.1%). Real-time PCR with Zip nucleic acid probes is a sensitive, specific and rapid detection method for mutations in the YMDD motif, which will be essential for monitoring patients undergoing Lamivudine antiviral therapy.

• Asian Pacific Journal of Cancer Prevention
• /
• v.13 no.12
• /
• pp.6175-6179
• /
• 2012

Intestinal parasitic infections (IPIs) are still important to the health of Thai rural residents. IPIs are the cause of many chronic diseases with, for example, opisthorchiasis resulting in progression to cholangiocarcinoma (CCA). This cross-sectional study in a prospective cohort study aimed to examine the prevalence and co-infection of intestinal parasites among Northeastern Thai rural residents, recruited into the Khon Kaen Cohort Study (KKCS), and who were residing in areas of high-risk for developing CCA. On recruitment, subjects had completed questionnaires and provided fecal samples for IPI testing using the formalin ethyl acetate concentration technique. Data on selected general characteristics and the results of the fecal tests were analysed. IPI test results were available for 18,900 of cohort subjects, and 38.50% were found to be positive for one or more types of intestinal parasite. The prevalence of Opisthorchis viverrini (O. viverrini) infection was the highest (45.7%), followed by intestinal flukes (31.9%), intestinal nematodes (17.7%), intestinal protozoa (3.02%), and intestinal cestodes (1.69%). The pattern of different infections was similar in all age groups. According to a mapping analysis, a higher CCA burden was correlated with a higher prevalence of O. viverrini and intestinal flukes and a greater intensity of O. viverrini. Both prevention and control programs against liver fluke and other intestinal parasites are needed and should be delivered simultaneously. We can anticipate that the design of future control and prevention programmes will accommodate a more community-orientated and participatory approach.

• Parasites, Hosts and Diseases
• /
• v.48 no.3
• /
• pp.267-270
• /
• 2010

The principal objective of this study was to investigate the prevalence of toxoplasmosis in household and stray cats in Seoul, Republic of Korea. We collected blood samples from 72 stray and 80 household cats, and all samples were examined by ELISA and nested peR. The overall positive rates of Toxoplasma gondii in stray cats were 38.9% (28/72), with 15.3% (11/72) in ELISA and 30.6% (22/72) in peR. The positive rate in male stray cats was Slightly higher than that of female stray cats. The highest positive rate of T. gondii infection was noted in Gangnam and Songpa populations in ELISA and in Gwangjin population in PCR. In household cats, however, we could not detect any specific antibodies or DNA for T. gondii. In conclusion, we recognized that the infection rate of toxoplasmosis in stray cats in Seoul was considerably high but household cats were free from infection.

• Parasites, Hosts and Diseases
• /
• v.59 no.1
• /
• pp.97-101
• /
• 2021

The infection status with Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fishes from Yongjeon-cheon (a branch of Nakdong-gang) located in Cheongsong-gun, Gyeongsangbuk-do, the Republic of Korea (Korea). A total of 750 fishes in 19 species were examined by the artificial digestion method for 2 years (2019 and 2020). CsMc were detected in 378 (51.4%) out of 735 fishes in 14 species (73.7%), and the infection intensity was 666 per fish infected. In 2019, CsMc were found in 172 (68.0%) out of 253 fishes in 10 species, and the infection intensity was 565 per fish infected. In 2020, CsMc were detected in 206 (62.2%) out of 331 fishes in 10 species, and the infection intensity was 751 per fish infected. The other zoonotic trematode, ie. Metagonimus spp., Centrocestus armatus, Echinostoma spp. and Clinostomum complanatum, metacercariae were also detected in fishes from the survey streams, but their endemicities were relatively low. Conclusively, it was first confirmed that CsMc are highly endemic in fishes from Yongjeon-cheon in Cheongsong-gun, Gyeongsangbuk-do, Korea.