Practical Algorisms for PCR-RFLP-Based Genotyping of Echinococcus granulosus Sensu Lato

Echinococcus granulosus sensu lato (s.l.) is a causative agent of cystic echinococcosis or cystic hydatid disease in humans and domestic and wild animals. The disease is a serious health problem in countries associated with poverty and poor hygiene practices, particularly in livestock raising. We introduced a practical algorism for genotyping the parasite, which may be useful to many developing countries. To evaluate the efficiency of the algorism, we genotyped 3 unknown strains isolated from human patients. We found that unknowns 1 and 3 were included in G1, G2, and G3 genotypes group and unknown 2 was included in G4 genotype (Echinococcus equinus) according to the algorisms. We confirmed these results by sequencing the 3 unknown isolates cox1 and nad1 PCR products. In conclusion, these new algorisms are very fast genotype identification tools that are suitable for evaluating E. granulosus s.l. isolated from livestock or livestock holders, particularly in developing countries.

The Resistance Mechanism and Clonal Distribution of Tigecycline-Nonsusceptible Klebsiella pneumoniae Isolates in Korea

PURPOSE: Tigecycline is one of the drugs used to treat multi-drug resistant Klebsiella pneumoniae (K. pneumoniae) infections, including complicated skin and soft tissue infections, complicated intra-abdominal infection, and community-acquired pneumonia in the Republic of Korea. However, since its commercial release, K. pneumoniae resistance against tigecycline has been reported, and there is a serious concern about the spread of tigecycline resistant bacteria. MATERIALS AND METHODS: In this study, we collected and analyzed 342 isolates from 23 hospitals in the Republic of Korea to determine the mechanisms of tigecycline susceptibility and their clonal types. The hospitals include several from each province in the Republic of Korea, except Jeju, an island province, and nonsusceptibility among the isolates was tested by the disk diffusion method. In our lab, susceptibility was checked again using the broth dilution method, and clonal types were determined using the multilocus sequence typing protocol. Real-time PCR was performed to measure the ramR mutation in the isolates nonsusceptible to tigecycline, which would suggest an increased expression of the AcrAB multidrug pump. RESULTS: Fifty-six K. pneumoniae isolates were found to be nonsusceptible, 16% of the 342 collected. Twenty-seven and nine isolates of the tigecycline nonsusceptible isolates had mutations in the ramR and rpsJ genes, respectively; while 18 nonsusceptible isolates harbored the tetA gene. Comparison of isolates with and without ramR mutation showed a significant statistical difference (p<0.05) for expression of AcrAB. Moreover, the most common clonal types, as observed in our study, appear to be ST11 and ST789. CONCLUSION: Several dominate clonal types infer tigecycline resistance to K. pneumoniae, including ST11, ST768, ST15, ST23, ST48, and ST307. There does not seem to be a transferrable medium, such as plasmid, for the resistance yet, although mutation of the ramR gene may be a common event, accounting for 48% of the nonsusceptibility in this study.

Geographical Distribution and Relative Abundance of Vectors of Scrub Typhus in the Republic of Korea

A survey to determine the geographical distribution and relative abundance of potential vectors of scrub typhus was conducted from October to November 2006 at 13 localities throughout the Republic of Korea. Apodemus agrarius accounted for 97.6% (80/82) of all rodents, while only 2 Myodes regulus (2/82) were collected. A total of 10,860 chiggers were collected from A. agrarius belonging to 4 genera and 8 species, while only Walchia fragilis (40) was collected from Myodes regulus. Leptotrombidium pallidum (8,137; 74.9%), a vector of scrub typhus, was the predominant species collected from A. agrarius followed by Leptotrombidium scutellare (2,057, 18.9%), Leptotrombidium palpale (279; 2.7%), Leptotrombidium orientale (232; 2.1%), and Leptotrombidium zetum (79; 0.7%), Neotrombicula tamiyai (58; 0.5%), Euschoengastica koreaensis (16; 0.1%), and Cheladonta ikaoensis (2; < 0.1%). L. pallidum was the predominant chigger collected at collection sites in Gangwon (100%), Gyeonggi (87.2%), Chungnam (100%), Chungbuk (100%), Jeonbuk (73.9%), Jeonnam (77.0%), and Gyeongbuk (66.1%) provinces, whereas L. scutellare was the predominant chigger collected in Gyeongnam province (77.9%) and Jeju Island (62.3%). Data suggest a correlation between chigger population abundance and human cases of scrub typhus in Korea.

Effect of Cosensitization with Buckwheat Flour Extract on the Production of House Dust Mite-specific IgE

There are studies reporting food sensitization in infancy increases the risk of sensitization to inhalants later in life. We performed a study to evaluate whether cosensitization with buckwheat (BW) has an effect on the production of house dust mite-IgE. C3H/HeJ mice (4 weeks, female) were sensitized with house dust mite (HDM)/Al (OH)3, intraperitoneally on day 0, followed by 4 intranasal sensitizations (on days 14, 15, 16, and 21). Group 1 was cosensitized intragastrically with BW/cholera toxin (CT) (on days 0, 1, 2, 7, and 18) during sensitization with HDM, group 2 was cosensitized intragastrically with CT only (on days 0, 1, 2, 7, and 18), and group 3 was used as controls. HDM- and BW-IgE and antigen-specific T-cell proliferation and cytokine production were evaluated. In Group 1, BW-IgE levels were highest at week 4, and the HDM-IgE at week 3 (98.45+/-64.37 ng/mL and 169.86+/-55.54 ng/mL, respectively). In Group 2, HDM-IgE levels reached a peak at week 3, remarkably higher (810.52+/-233.29 ng/mL) compared to those of Group 1 (169.86+/-55.54 ng/mL). The interleukin (IL)-4 and interferon (IFN)-gamma in the HDM-stimulated culture supernatants of splenocytes were not significantly different among groups. We postulate that the cosensitization with BW may down-regulate the specific IgE response to HDM.

Family Outbreak of Trichinosis After Eating a Raw Meat of Wild Swine

Trichinosis is a worldwide parasitic infection caused by ingesting an uncooked raw meat containing viable larvae of nematode Trichinella. Although most cases have been reported in Western countries, the incidence has decreased due to strict control of meat handlings and improved hygiene in these countries. In Korea, the first case of Trichinella spiralis was reported in a patient who ingested an uncooked badger. We have also experienced four cases of Trichinella spiralis infestation among family members who showed typical clinical manifestations and laboratory findings after ingesting raw wild swine meat, and herein report the finding.

Family Outbreak of Trichinosis After Eating a Raw Meat of Wild Swine

Trichinosis is a worldwide parasitic infection caused by ingesting an uncooked raw meat containing viable larvae of nematode Trichinella. Although most cases have been reported in Western countries, the incidence has decreased due to strict control of meat handlings and improved hygiene in these countries. In Korea, the first case of Trichinella spiralis was reported in a patient who ingested an uncooked badger. We have also experienced four cases of Trichinella spiralis infestation among family members who showed typical clinical manifestations and laboratory findings after ingesting raw wild swine meat, and herein report the finding.

Isolation of Human scFv Antibodies Specific for House Dust Mite Antigens from an Asthma Patient by Using a Phage Display Library

BACKGROUND: In order to characterize human antibodies with specificity for mite allergens at the molecular level, a scFv phage display library was constructed using peripheral blood mononuclear lymphocytes from an asthma patient allergic to mite as Ig gene sources. METHODS: Immunoglobulin VH and V gene fragments were obtained by polymerase chain reaction, and randomly combined in pCANTAB-5E vector. The resulting human scFv phage display library had 3 X 10(4) independent clones, and biopanning was performed with house dust mite extracts. RESULTS: Four scFv clones specific for house dust mite extract were isolated. Immunoblot assay showed that our clones reacted to 25 kDa and 50~60 kDa proteins with unknown identity in mite extracts. Sequence analysis indicated that two clones (b7 and c15) are identical, and all clones belong to human VH3 subgroup. On the other hand, light chain usage was different in that two clones (a2 and b7/c15) belonging to V kappa 4 subgroup, but a4 used V kappa 1 light chain gene. CONCLUSION: Our approach should facilitate provision of useful information on the antibody responses against allergens at the molecular level in humans.

The egg detection rates of Enterobius vermicularis among school children in the various regions

A total of 860 cellotape anal swab specimens from 326 school children of urban area, 243 of rura1 farm village and 291 of rural fishing village was submitted for Enterobius vermicularis egg detection from September through November 1985. Each specimen was collected in the morning. Among the total 860 children's submitting specimens, 316 (36.7 per cent) were positive for E. vermicularis eggs. Of the 326 children in the urban area, E. vermicularis eggs were detected in the 45 (13.8 per cent). This detection rate was lower significantly as compared with 143 (55.6 per cent) of 243 children in the farm village or 136 (46.7 per cent) of 291 children in the fishing village. The egg detection rate in the male children was lower remarkably than that in the female children.