Evaluation of DNA Extraction Methods and Their Clinical Application for Direct Detection of Causative Bacteria in Continuous Ambulatory Peritoneal Dialysis Culture Fluids from Patients with Peritonitis by Using Broad-Range PCR

BACKGROUND: The aims of this study were to compare several DNA extraction methods and 16S rDNA primers and to evaluate the clinical utility of broad-range PCR in continuous ambulatory peritoneal dialysis (CAPD) culture fluids. METHODS: Six type strains were used as model organisms in dilutions from 10(8) to 100 colony-forming units (CFU)/mL for the evaluation of 5 DNA extraction methods and 5 PCR primer pairs. Broad-range PCR was applied to 100 CAPD culture fluids, and the results were compared with conventional culture results. RESULTS: There were some differences between the various DNA extraction methods and primer sets with regard to the detection limits. The InstaGene Matrix (Bio-Rad Laboratories, USA) and Exgene Clinic SV kits (GeneAll Biotechnology Co. Ltd, Korea) seem to have higher sensitivities than the others. The results of broad-range PCR were concordant with the results from culture in 97% of all cases (97/100). Two culture-positive cases that were broad-range PCR-negative were identified as Candida albicans, and 1 PCR-positive but culture-negative sample was identified as Bacillus circulans by sequencing. Two samples among 54 broad-range PCR-positive products could not be sequenced. CONCLUSIONS: There were differences in the analytical sensitivity of various DNA extraction methods and primers for broad-range PCR. The broad-range PCR assay can be used to detect bacterial pathogens in CAPD culture fluid as a supplement to culture methods.

Pharmacotherapy for imported parasitic diseases with drugs reserved by the government

Parasitic diseases are widely distributed throughout the world. Recently, travel abroad and migration from abroad are increasing in Korea. Therefore, it is necessary to appropriately control imported parasitic disease. The drugs for the treatment of the parasitic diseases that can be imported from abroad are reserved by the government. To guide proper treatment of parasitic diseases, recommended chemotherapy focused on these reserved drugs has been introduced. The diseases reviewed in this article include malaria, babesiosis, toxoplasmosis, leishmaniasis, Chagas disease, African sleeping sickness, filariasis, angiostrongyliasis, and fascioliasis. Because most of the parasitic diseases produce severe illness or fatal results, rapid and accurate diagnosis is important and following fully the recommended therapy is needed. The recommended drug therapy changes from time to time due to various factors, so always recognizing and applying the latest therapy and is very important.

Prevalence of Plasmid-mediated Quinolone Resistance and Its Association with Extended-spectrum Beta-lactamase and AmpC Beta-lactamase in Enterobacteriaceae / 대한진단검사의학회지

BACKGROUND: We investigated the prevalence of plasmid-mediated quinolone resistance and its association with extended-spectrum beta-lactamase (ESBL) and AmpC beta-lactamase in Enterobacteriaceae. METHODS: A total of 347 non-duplicated isolates of Enterobacteriaceae were collected between August and October 2006 from 2 hospitals. Qnr determinant screening was conducted using PCR amplification, and all positive results were confirmed by direct sequencing. Qnr-positive strains were determined on the basis of the presence of ESBL and AmpC beta-lactamase genes. RESULTS: The qnr gene was detected in 47 of 347 clinical Enterobacteriaceae isolates. Among the 47 qnr-positive strains, Klebsiella pneumoniae (N=29) was the most common, followed by Escherichia coli (N=6), Enterobacter cloacae (N=6), Citrobacter freundii (N=5), and Enterobacter aerogenes (N=1). These isolates were identified as qnrA1 (N=6), 8 qnrB subtypes (N=40), and qnrS1 (N=1). At least 1 ESBL was detected in 38 of the 47 qnr-positive strains. Qnr-positive strains also showed high positive rates of ESBL or AmpC beta-lactamase, such as TEM, SHV, CTX-M, and DHA. DHA-1 was detected in 23 of 47 qnr-positive strains, and this was co-produced with 1 qnrA1 and 22 qnrB4. Strains harboring MIR-1T and CMY were also detected among the qnr-positive strains. Antimicrobial-resistance rates of qnr-positive strains to ciprofloxacin, levofloxacin, norfloxacin, nalidixic acid, and moxifloxacin were 51.1%, 46.8%, 46.8%, 74.5%, and 53.2%, respectively. CONCLUSIONS: The qnr genes were highly prevalent in Enterobacteriaceae, primarily the qnrB subtypes. They were closely associated with EBSL and AmpC beta-lactamase.

The Optimal Wavelength of Spectrophotometric Broth Microdilution Antifungal Susceptibility Test for Flucytosine and Three Azoles / 대한진단검사의학회지

BACKGROUND: There is no guideline for the appropriate wavelength at which to measure the optical density (OD) value in broth microdilution antifungal susceptibility testing, although a spectrophotometric reading method is commonly used. The present study aimed to analyze the difference in the OD values over the range of visible light and to ascertain the optimal wavelength for the spectrophotometric method of microdilution testing. METHODS: We measured the OD of background blank controls of broth medium, antifungal agents, and inocula of five type strains using a Synergy HT multi-detection microplate reader at 5-nm intervals from 380 nm to 760 nm. We also estimated the OD differences between the 50% of growth control and blank control. RESULTS: The OD of the blank control showed a parabola shape with two peaks and steadily decreased at longer wavelengths. The curves of the antifungal agent were similar to those of blank controls, and the influence of each antifungal agent on the OD was minimal. For the difference in OD between 50% of growth control and the blank control, the curve was the opposite of the blank control, and the OD increased steadily at the wavelengths above 600 nm. CONCLUSIONS: The range between 600 nm and 700 nm was the optimal wavelength for broth microdilution antifungal susceptibility testing, although any wavelength within the visible light spectrum can be used.

Genetic Characteristics of Polymorphic Antigenic Markers among Korean Isolates of Plasmodium vivax

Plasmodium vivax, a protozoan malaria parasite of humans, represents a major public health concern in the Republic of Korea (= South Korea). However, little is known about the genetic properties and population structures of the P. vivax isolates circulating in South Korea. This article reviews known polymorphic genetic markers in South Korean isolates of P. vivax and briefly summarizes the current issues surrounding the gene and population structures of this parasite. The critical genetic characteristics of major antigens of the parasite, such as circumsporozoite protein (CSP), merozoite surface protein 1 (MSP-1) and MSP-3, Duffy binding protein (DBP), apical membrane antigen 1 (AMA-1), and GAM-1, are also discussed.

Reemergence of Malaria in Korea

Malaria is one of the most important tropical diseases but also occurring in many temperate regions. After more than 10 years' absence, vivax malaria reemerged in Korea in 1993. The annual occurrence has been increased rapidly, reaching 4,142 cases in 2000. It started to decrease and fell to 826 cases in 2004. Recently, however, the incidence tends to increase. Anopheles sinensis is the major vector of malaria in Korea, and its vectorial capacity is low. This endemic occurred in the northern part of South Korea near the Demilitarized Zone (DMZ). The patients suffered from the typical illness of vivax malaria. It is noteworthy that thrombocytopenia occurred in more than 70% of the patients. It is believed that the malaria is properly diagnosed and treated over the nation along the accumulation of experience. To control the disease, more elaborated programs should be conducted in collaboration with North Korea.

Therapeutic evaluation of sustained-releasing praziquantel (SRP) for clonorchiasis: Phase 1 and 2 clinical studies

Sustained-releasing praziquantel (SRP) tablet was designed for single dose treatment regimen of clonorchiasis. A previous pre-clinical study confirmed its sustained-releasing characteristics and a better cure rate than conventional praziquantel (PZQ). In this clinical study, the pharmacokinetics of this SRP tablet were investigated in human volunteers (phase 1; 12 volunteers), and its curative efficacy was examined in clonorchiasis patients (phase 2; 20 volunteers). In the phase 1 clinical study, blood concentrations of both tablets showed wide individual variation. The AUC(last) of SRP was 497.9+/-519.0 ng.hr/ml (mean+/-SD) and PZQ of 628.6+/-695.5 ng.hr/ml, and the AUC(inf) of SRP was 776.0+/-538.5 ng.hr/ml and of PZQ 658.6+/-709.9 ng.hr/ml. C(max) values of SRP and PZQ were 90.7+/-82.2 ng/ml and 214.9+/-251.9 ng/ml, and T(max) values were 3.42+/-1.43 hr and 1.96+/-1.23 hr, respectively. SRP tablets showed similar AUC values, but lower C(max) and longer T(max) values than PZQ. In the phase 2 study, SRP at 30 mg/kg (single dose) achieved a 60% cure rate and a 95.5% egg reduction rate. The cure rate of a single dose SRP was unsatisfactory compared with that of the conventional PZQ dose, but much better than that achieved by a single dose PZQ.

Cloning of a pore-forming subunit of ATP-sensitive potassium channel from Clonorchis sinensis

A complete cDNA sequence encoding a pore-forming subunit (Kir6.2) of ATP-senstive potassium channel in the adult worm, Clonorchis sinensis, termed CsKir6.2, was isolated from an adult cDNA library. The cDNA contained a single open-reading frame of 333 amino acids, which has a structural motif (a GFG-motif) of the putative pore-forming loop of the Kir6.2. Peculiarly, the CsKir6.2 shows a lack-sequence structure, which deleted 57 amino acids were deleted from its N-terminus. The predicted amino acid sequence revealed a highly conserved sequence as other known other Kir6.2 subunits. The mRNA was weekly expressed in the adult worm.

Analysis of polymorphic regions of Plasmodium vivax Duffy binding protein of Korean isolates

The present study was designed to investigate polymorphism in Duffy binding protein (DBP) gene of Plasmodium vivax isolates of Korea. Thirty samples were obtained from P. vivax patients in Yonchon-gun, Kyonggi-do in 1998. The PCR products of the samples were subjected to sequencing and hybridization analyses of the regions II and IV of P. vivax DBP gene. Two genotypes, SK-1 and SK-2, were identified on the basis of amino acid substitution and deletion. The genotype of 10 isolates was SK-1 and that of 20 isolates was SK-2. Most of the predicted amino acids in the region II of DBP gene were conserved between the Korean isolates and Belem strain except for 4-5 amino acid substitutions. In the region IV of DBP, a 6-bp insert that was shown in the Sal-1 allele type was found in SK-1, and a 27-bp insert that was shown in the Papua New Guinea allele type was found in SK-2. In conclusion, the present findings suggest that two genotypes of P. vivax coexist in the endemic area of Korea.

Evaluation of LG Malaria Anti-PvTM for Diagnosis of Plasmodium vivax Malaria in the Republic of Korea / 대한임상병리학회지

BACKGROUND: In the Republic of Korea, Plasmodium vivax malaria, which had disappeared since 1984, re-emerged in 1993. Currently, malaria is becoming a serious public health problem in the Republic of Korea. The diagnosis of malaria has relied on microscopic examination such as thin and thick blood smears. However, even for expert microscopists, this test is a laborious and time-consuming procedure. Therefore, the development of a reliable, easy, and convenient diagnostic test is crucial. Recently, the LG malaria anti-PvTM enzyme-linked immunosorbent assay (ELISA) kit for the detection of a specific antibody against the merozoite surface protein (MSP) of P. vivax was developed. The aim of this study was to evaluate the diagnostic kit for P. vivax malaria in the Republic of Korea. METHODS: To determine the usefulness of the LG malaria anti-PvTM as a diagnostic kit for vivax malaria, a total of 59 serum samples from patients with P. vivax malaria were tested. The patients were diagnosed microscopically and the parasitemia index of their blood was calculated. Sera from 203 uninfected healthy blood donors, which were microscopically negative for Plasmodium vivax, were used as negative controls. RESULTS: The sensitivity and specificity of the LG malaria anti-PvTM were 98.31% (58/59) and 98.03% (199/203), respectively. The false-positive and false-negative rates were 1.97% (4/203) and 1.69% (1/59), respectively. CONCLUSIONS: The diagnostic kit, LG malaria anti-PvTM, might be a useful tool for diagnosis and screening of P. vivax malaria in Korea.

Three cases of vivax malaria showing atypical clinical course / 감염

Vivax malaria has been endemic in Korea since the 15th century. In the 1960s a Malaria Eradication Project was introduced by the Korean government in conjunction with the World Health Organization (WHO). In 1979, WHO declared Korea a malaria-free area. Thereafter, any cases of malaria in Korea were imported cases. In 1993 a case of malaria, that was not imported, was identified. From then, malaria cases have increased exponentially and have tended to expand toward souther areas of Korea. We experienced three cases showing atypical clinical course of vivax malaria. In the first case, the patient had a spike of fever after the completion of standard chloroquine-primaquine therapy. He revealed the recrudescence of vivax malaria. The second one was asymptomatic parasitemia. The patient had no complaint for the prolonged period despite low level of parasitemia. The third patient was natural healing or vivax malaria with a relative long incubation period. Therefore we report these atypical cases with review.

Malaria Situation in the Republic of Korea

No abstract available.

A Case of Stongyloidiasis Associated with Acute Hemorrhagic Gastritis / 대한소화기내시경학회지

A 69-year-old male was admitted to the neurosurgery department for traumatic intracra-nial hemorrhage in both frontal lobes. After 2 months, he complained of epigastric dis-comfort, nausea, vomiting, and loose stools. The gastric endoscopic examination found acute hemorrhagic gastritis and there were rhabditoid nematode larvae in the gastric fluid and biopsy sections. The filariform larvae of Strongyloides sp. were discovered from a fecal culture. The patient was treated with albendazole (200 mg, po bid, for 4 weeks). The epigastric discomfort disappeared and endoscopic findings improved after treatment.

A Case of Imported Falciparum Malaria in a child

Despite on-going efforts to control malaria, the rate of malaria has not decreased throughout the world. It was believed that endemic malaria had been eradicated in Korea since the end of the 1970s, however it reemerged from 1993 and has been increasing ever since. Besides endemic malaria, imported malaria is also increasing in Korea as the number of overseas travellers and foreign workers increases. We discovered malaria in a two-year-old child who visited Sierra Leone with his missionary father. The patient contracted malaria despite chemo-prophylaxis with chloroquine and was diagnosed as falciparum malaria by blood smear examination and IFAT. He successfully recovered after administraion of quinine and clindamycin without complication. However, the malaria did not respond quickly to chloroqine and Fansidar but a drug resistence test was not performed.

A Case of Intraerythrocytic Parasitism Treated with Quinine and Clindamycin / 감염

Although rapid diagnosis of human babesiosis usually can be made by microscopic examination of thin and thick blood smears, differentiation between Babesia microti and Plasmodium falciparum can be quite difficult. The parasite is often not visualized in the early course of infection or in a partially treated case and the young trophozoites of these two organisms are similar. Recently, we experienced a case, which was thought as human babesiosis initially by microscopic examination of the Giemsa-stained thin blood smears, but was finally diagno-sed as P. falcifarum infection by indirect immunofluorescent antibody assay and polymerase chain reaction. The patient was treated successfully with quinine and clindamycin, which are effective in both infections. When differential diagnosis is difficult, we suggest combination therapy of quinine and clindamycin as an empirical regimen.

Karyotypes of Pneumocystis carinii from Korean rats

Molecular karyotyping was applied to Pneumocystis carinii(Pc) from two strains of experimental rats, Sprague Dawley(SD) and Fisher(F), in Korea. Field inversion gel electrophoresis and contour clamped homogeneous electric field electrophoresis resolved 15 chromosomal bands from the Pc. The size of the bands was estimated 270kb to 684kb from SD rats, and 273kb to 713 kb from F rats. The bands of 283 kb from SD rats and of 273 kb from F rats stained more brightly suggesting duplicated bands. Total number of chromosomes was at least 16, and total genomic size was estimated 7 x 10(6) bp. All of the bands from F rats hybridized to the probe of repeated DNA sequences of Pc and the band of 448 kb size was proved to contain rDNA sequences, but Pc. chromosome bands from SD rats showed no reactions to the probes. The 2 different karyotypes of P. carinii from 2 strains of rats were maintained consistently for 2 years.

A case of babesiosis in an eight year old Korean boy

No abstract available.

A case of babesiosis in an eight year old Korean boy

No abstract available.