Epidemiology and Subtype Distribution of Blastocystis Among Asymptomatic Volunteers in South Korea: A Multicenter Study / 대한임상미생물학회지

Background@#Blastocystis is a genus of intestinal, anaerobic protozoan parasites that can be isolated from humans, animals, and the environment. We aimed to determine the distribution of Blastocystis and subtypes (STs) using stool samples obtained from healthy volunteers at collection centers in South Korea. @*Methods@#A total of 478 stool samples from volunteers were collected at five collection centers throughout South Korea. The presence of Blastocystis was determined using PCR based on the small subunit (SSU) rRNA gene, and Blastocystis STs were confirmed through sequencing of the SSU rRNA gene. @*Results@#Molecular analysis revealed the presence of Blastocystis in 27 (5.6%) of the enrolled participants. Two STs were identified: ST3 (66.7%) and ST1 (33.3%). The positive rates of Blastocystis varied by geographical region, ranging from 1.2%–12.0%. ST3 was the predominant subtype in all centers except one, where only ST1 was isolated. Phylogenic analysis showed clustering based on ST, but no significant differences were found among the regions. There was no association between Blastocystis colonization and either age or sex of the participants. @*Conclusions@#The results of this multicenter study demonstrated colonization by Blastocystis, mainly ST3, in the gastrointestinal tracts of asymptomatic individuals in South Korea.

Clinical and Microbiological Risk Factors for Community-Associated Clostridioides difficile Infections / 대한임상미생물학회지

Background@#The incidence of community-associated (CA) Clostridioides difficile infection (CDI) has increased in Korea. In this study, we evaluated CA-CDI risk factors in terms of clinical features and ribotype considering its region-specific molecular epidemiology. @*Methods@#A retrospective case-control study was performed on two groups of CDI patients:127 subjects with CA-CDI and 265 subjects with healthcare-associated (HA)-CDI. Risk factors for CA-CDI were evaluated in terms of clinical and microbiological features such as toxin type and ribotype. @*Results@#A comparison of the two groups of CDI patients revealed that inflammatory bowel disease, diarrhea, abdominal pain, and fever were more closely associated with CA-CDI. The toxin types and ribotypes of C. difficile were similar between the two groups. After adjusting for variables, no risk factors were identified for CA-CDI compared with HA-CDI. @*Conclusion@#Specific risk factors for CA-CDI were not identified in this study.

Clinical and Microbiological Risk Factors for Severe Clostridioides difficile Infections / 대한임상미생물학회지

Background@#There has been a marked increase in the mortality rate associated with Clostridioides difficile infection (CDI) globally since 2003, with the emergence of binary toxinproducing ribotype 027 strains. However, the molecular epidemiology of C. difficile shows regional differences and ribotype 027 is not common in Korea. In this study, the risk factors for severe CDI were evaluated, while considering the region-specific molecular epidemiology. @*Methods@#A retrospective case-control study was performed. Cases (n = 149) included patients with severe CDI or severe complicated CDI. Controls (n = 155) consisted of patients with nonsevere CDI. @*Results@#Advanced age (odds ratio [OR] = 1.017, P = 0.0358), a history of chemotherapy (OR = 2.695, P = 0.0464), and ribotype 002 (OR = 3.406, P = 0.0231) were statistically significant factors associated with severe CDI in a multivariate analysis. @*Conclusion@#Ribotype 002 was found to be a significant risk factor for severe CDI in this study.Therefore, the surveillance of C. difficile ribotypes is recommended to monitor the spread of high-risk clones.

Septicemia Caused by Herbaspirillum huttiense Secondary to Pneumonia

No abstract available.

Analytical Performance of Bio-Rad D-100 on a Hemoglobin A1c Assay

BACKGROUND: Hemoglobin A1c (HbA1c) is considered a marker useful for the follow-up and diagnosis of diabetes and implies the importance of reliable assay methods that are traceable to a reference method. We evaluated analytical performance of a new high-performance liquid chromatography system for the HbA1c assay: D-100 from Bio-Rad Laboratories (USA). METHODS: We evaluated precision, linearity, and carry-over of D-100, according to the Clinical and Laboratory Standards Institute's guidelines. Comparative analysis of D-100 with Integra 800 (Roche Diagnostics, Germany) and Capillarys 3 (Sebia, France) was conducted. Additionally, we evaluated the throughput of the three instruments. RESULTS: Precision of low- and high-concentration controls in D-100 showed a CV of less than 1%. The linearity was excellent (R²=0.999) in the range of 3.51-18.7%, and carry-over was not observed. HbA1c results of D-100 (n=144) showed good correlation with those of Integra 800 (r=0.993) and Capillarys 3 (r=0.996). The % bias between D-100 and Integra 800 or Capillarys 3 was within the allowable range at all 3 medical decision levels (5.7%, 6.5%, and 10.0%). Elapsed time in the analysis of the first sample by D-100 was shorter than that of Integra 800 (2.4 vs. 11.1 minutes), but subsequent samples took more time (0.8 vs. 0.3 minutes per sample). CONCLUSIONS: D-100 showed reliable analytical performance with good precision and linearity, minimal carry-over, and acceptable comparative characteristics relative to other instruments. D-100 is expected to be useful for clinical measurements of HbA1c for diabetes diagnosis and theranostics.

Change of Serum Prostate-specific Antigen with Age in Korean Men / 대한비뇨기과학회지

PURPOSE: Prostate-specific antigen(PSA) is believed to be the most useful tumor marker available for prostate cancer. Our intension was to establish the normal pattern of PSA changes with age and initial PSA to provide baseline data from which disease progression might be detected. MATERIALS AND METHODS: Patients, who received serum PSA screening test more than twice, between January 1997 and December 2005, at the health center of Asan Medical Center, were selected for this investigation. The PSA levels of 27,439 adult males, aged between 20 and 79 years, with no known prostate disease, were determined using the Tandem-R PSA assay (Hybritech). The PSA values were determined at the baseline and after 1 to 8 years. To estimate the increase in the level of serum PSA according to age, a one-way ANOVA test was carried out. Every change in an individual's PSA level was compiled to plot curves of the PSA according to the initial age and initial PSA. The PSA doubling times were also calculated with different PSA values at different ages. RESULTS: The mean PSA levels according to age steadily increased, and were directly correlated with age(p<0.001). These increases were greater for those in their fifties and most severe after their sixties. The future PSA and doubling time of an individual can be predicted based on his age and known history of PSA. CONCLUSIONS: The model indicates the expected rises in the PSA level in relation to age and the PSA doubling times in healthy Korean men. This will provide baseline data from which disease progression might be detected.

The Impact of Height, Weight and Body Mass Index(BMI) in Young Men with Varicoceles / 대한남성과학회지

PURPOSE: To assess the impact of physical characteristics on the incidence of varicoceles. Although previous reports have alluded to the fact that taller individuals may have a higher incidence of varicoceles, this has not been systematically studied. We hypothesized that physical characteristics such as height and weight could have a significant impact on the incidence of varicoceles. MATERIALS AND METHODS: We retrospectively reviewed charts of 145 patients who presented for evaluation of varicocele between 2000~2005. Each patients' age, symptoms, height, weight and body mass index (BMI) were recorded. Independent t-tests were performed to determine whether a correlation existed between presence of a varicocele and height, weight, or BMI. Moreover, we selected 90 patients whose varicocele was detected by pain and performed the same analysis in order to exclude selection bias. Additionally, we compared varicocele grade with height, weight and BMI by one-way ANOVA test. RESULTS: Our analysis showed that there was no association between height and the presence of a varicocele. However, the weight of the patient and the incidence of varicocele approached significance with greater weight associated with a lower incidence of varicoceles. There was also an association between BMI and the presence of varicoceles but the correlation did not depended on varicocele grade. CONCLUSIONS: Although previous reports have alluded to a higher incidence of varicoceles in taller patients, the current study found no correlation between height and the presence of a varicocele. Increased weight, however, was associated with a significantly lower incidence of varicoceles. Varicocele grade was not correlated with any factor. This study demonstrates that height is not a consideration when evaluating the infertile male, whereas weight may affect the ability to diagnose the varicocele.