Donghoon Lim

Accuracy of Conventional PCR Targeting the 16S rRNA Gene with the Ot-16sRF1 and Ot-16sRR1 Primers for Diagnosis of Scrub Typhus: a Case-Control Study

ABSTRACT We retrospectively evaluated the accuracy of conventional PCR targeting the 16S rRNA gene (16S C-PCR) using the Ot-16sRF1/Ot-16sRR1 primers for diagnosing scrub typhus. The diagnosis of Orientia tsutsugamushi infection by 16S C-PCR presented an increased sensitivity of 87.0% and specificity of 100% compared with those obtained with other targets and is thus a simple and clinically useful method with good diagnostic accuracy.

Hypolipidemic and antioxidant effects on hypercholesterolemic rats of polysaccharide from Salicornia bigelovii seed

The hypolipidemic and antioxidant effects of dietary supplementation with polysaccharide isolated from Salicornia bigelovii seed (SBS) were evaluated in hypercholesterolemic rats. Following administration of SBS polysaccharide at 200mg/kg BW/day (HPS group), total cholesterol (TC), and low density lipoprotein cholesterol (LDLC) levels were 32.45% and 58.09% lower than those in negative controls (NC) group, respectively. However, in the case of high density lipoprotein cholesterol (HDLC), it was 36.37% higher than that of NC group. The arteriosclerosis and cardiac risk indices were 64.23% and 50.53% lower than in the NC group. However, the HTR (HDLC/TC) value was higher 2.05-fold than that of the NC group. Hydroxy-3-methylglutaryl CoA reductase activity in HPS group was 55.1% lower than that of the NC group. Activities of alanine transferase, aspartate aminotransferase, and alkaline phosphatase in HPS group were 29.71%, 26.49%, and 32.24%, lower than that of the NC group. SOD, CAT, and GSH-Px activities in HPS group were 31.05%, 49.29%, and 54.62% higher than that of the NC group. These results indicate that SBS polysaccharide has both hypolipidemic and antioxidant effects and shows potential for ameliorating hypercholesterolemia.

Case Report: Polymerase Chain Reaction Testing of Tick Bite Site Samples for the Diagnosis of Human Granulocytic Anaplasmosis

Human granulocytic anaplasmosis (HGA) is a tick-borne infectious disease caused by Anaplasma phagocytophilum, an obligate intracellular bacterium. Until now, the utility of tick-bite site samples for HGA diagnosis has not been reported. Using a patients buffy coat and tick-bite site crust samples, we performed polymerase chain reaction (PCR) testing using Ehrlichia- or Anaplasma-specific primers. PCR with buffy coat and crust samples obtained before doxycycline administration was positive. Six days after doxycycline administration, PCR with the buffy coat sample was negative but PCR with a crust tissue sample from the tick-bite site remained positive. This is the first case to suggest that crust tissue at the tick-bite site may be useful for early HGA diagnosis in patients who have already been treated with antibiotics such as doxycycline.

Antihyperglycemic and antioxidant activities of polysaccharide produced from Pleurotus ferulae in streptozotocin-induced diabetic rats

We investigated the antihyperglycemic and antioxidant activities of polysaccharides produced from Pleurotus ferulae mutant in streptozotocin-induced diabetic rats. Blood glucose level in the STZ-induced diabetic rat administered the extract polysaccharides, 250mg/kg b·w/d (EPSG) was 196.97mg/dL, approximately 54.12% less compared to that of the STZ-induced diabetic rats administered 0.9% NaCl solution (NCG). The insulin level in the EPSG was approximately 1.64-fold higher than that in the NCG. HDL and LDL cholesterol levels in the EPSG were 29.15mg/L and 20.35mg/dL, respectively, representing an approximate increase of 69.18% and decrease of 38.52%, respectively. The activities of aspartate aminotransferase (AST) and alanine transferase (ALT) in the EPSG decreased approximately by 49.27 and 50.43%, respectively, while the alkaline phosphatase (ALP) activity decreased by 34.25%, relative to the NCG. Antioxidant activities in the NCG decreased relative to the normal group. In contrast, for EPSG, these values increased relative to the NCG. The malondialdehyde level in the EPSG was 12.95mmol/mg protein, which was approximately 70.64% of that in the NCG. These results suggest that the polysaccharides of Pleurotus ferulae mutant could be developed as potential antidiabetic agents or functional foods for people with a high risk of diabetes mellitus.

Assessment of Efflux Activity Using H33342 Accumulation in Tigecycline-Resistant Acinetobacter baumannii Clinical Isolates

Background: Tigecycline resistance has emerged recently and has shown diverse mechanisms. The aim of this study was to assess the role of efflux activity in tigecycline resistance in 120 clinical isolates of A. baumannii using two methods: the H33342 accumulation assay and adeB real-time reverse transcriptase polymerase chain reaction. In addition, we analyzed the correlation between the expression level of adeB and H33342 accumulation level. Methods: A. baumannii clinical isolates was divided into tigecycline-resistant (49 strains), intermediate (40 strains), and susceptible (31 strains) groups. The H33342 accumulation was measured in the absence or presence of the efflux pump inhibitor carbonyl cyanide 3-chlorophenylhydrazone (CCCP). Real-time RTPCR was performed to determine the relative expression of the adeB gene in A. baumannii clinical isolates. Results: The level of H33342 accumulation in the resistant group was relatively lower than those in the other groups. The addition of CCCP caused a significantly increased fold change in H33342 accumulation in the tigecycline-resistant group. Significant difference in the fold change level in H33342 accumulation was found between tigecycline-susceptible and resistant isolates. Those findings support the role of efflux pumps of which substrates are H33342 in the resistance of tigecycline. Significant differences in the relative expression levels of adeB were shown between tigecycline-susceptible and resistant groups also. Conclusion: The results showed that several efflux pumps of which substrates were H33342 can contribute to tigecycline resistance. The adeB overexpression can also contribute to tigecycline resistance. It is possible that efflux pumps other than adeB efflux pumps contribute to tigecycline resistance because there was no correlation between fold change level in H33342 accumulation and adeB expression level. (Ann Clin Microbiol 2017;20:90-96)