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.

Optimal conditions for the removal of house dust mite, dog dander, and pollen allergens using mechanical laundry.

BACKGROUND: Mechanical laundry is an effective tool for the environmental control of allergens, but the optimal conditions for removing allergens are not yet clear. OBJECTIVE: To evaluate the optimal conditions of mechanical laundry for the removal of house dust mite (HDM), dog dander, and pollen allergens. METHODS: The 4 washing modes of 30 degrees C (86 degrees F), 40 degrees C (104 degrees F), 60 degrees C (140 degrees F), and steam water (SW) with detergent were evaluated. Allergen removal performance was assayed using a 2-site enzyme-linked immunosorbent assay (ELISA) or an ELISA inhibition test. RESULTS: Using the 30 degrees C and 40 degrees C washing modes, only 6.5% and 9.6% of Dermatophagoides farinae, respectively, were killed. However, using the 60 degrees C and SW washing modes, all HDMs were killed. The amounts of Der f 1 remaining after the 30 degrees C, 40 degrees C, 60 degrees C, and SW washing modes were 26.8%, 2.4%, 1.3%, and 0.6%, respectively, with unmanipulated contaminated sheets. The effects of rinse on Der f 1 levels after the 30 degrees C washing were greater compared with those after the 40 degrees C, 60 degrees C, and SW modes. The amounts of Can f 1 in the extractions after washing were 0.3% to 1.3% for all modes, and all extracts, even without a rinse, did not inhibit specific IgE binding to dog allergens according to ELISA. The remaining pollen allergen levels after washing were lower in the 60 degrees C and SW modes than in the lower temperature modes. However, the levels did not differ among the various washing modes after rinsing once. CONCLUSION: Water temperature and number of rinses are critical factors for the removal of HDM, dog dander, and pollen allergens.

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)-beta 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.

Effectiveness of education for control of house dust mites and cockroaches in Seoul, Korea.

We evaluated the efficacy of health education in reducing indoor arthropod allergens in Seoul. The mite control measures comprised the use of mite-proof mattress and pillow coverings, regular washing of potentially infested materials, maintenance of a low humidity, removal of carpets, and frequent vacuum cleaning. Cockroach control measures included trapping, application of insecticides, and protecting food. Of 201 homes enrolled in October 1999, 63 volunteers were included in a 2-year follow-up survey between April 2000 and January 2002. Before intervention, the density of mites/g of dust varied greatly; 27.1/g in childrenos bedding, 20/g in adult bedding, 7.2/g on the floors of childrenos bedrooms, 6.8/g in sofas, 5.9/g on the floors of adultos bedrooms, 3.9/g on living room floors, 3.7/g in carpets, and 1.9 mites/g on kitchen floors. The predominant mite species and house percentages infested were; Dermatophagoides farinae 93%, D. pteronyssinus 9%, and Tyrophagus putrescentiae 8%. Comparing 1999 and 2001 infestations, before and after 25 mo of education, mite abundance was reduced by 98%, from 23.7 to 0.57 mites/g of dust. In 1999, cockroaches were detected in 62% homes: 36% Blattella germanica and 35% Periplaneta spp., including 9% double infestations of B. germanica and P. americana. Following intervention, cockroach infestation rates decreased to 22% of houses in 2000 and 23% in 2001. We conclude that continuous and repetitive health education resulted in the effective control of domestic arthropods.

[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.