Determination of the Critical Concentration of Rifabutin for Susceptibility Testing Using the Proportion Method with Löwenstein-Jensen Medium against Mycobacterium Tuberculosis Isolates.

OBJECTIVE: To determine the critical concentration of rifabutin (RFB) for susceptibility testing against Mycobacterium tuberculosis (Mtb) on Löwenstein-Jensen (L-J) medium using the proportion method. METHODS: We used 47 strains were used to determine the critical concentration of RFB. The microplate antimicrobial assay (MABA) was used as a reference method. We used 160 strains to evaluate its correlation with the classification results derived from the MABA method. We performed antimicrobial susceptibility testing (AST) against RFB and rifampin (RIF) for 2748 other strains using the proportion method on L-J medium. RESULTS: The determined critical concentration for RFB was 20 µg per mL. Identical classification as susceptible or resistant was observed in 93.8% and 92.5% strains for RFB and RIF, respectively, using the 2 different methods. The cross-resistance ratio between RFB and RIF was 72.7% in the 2748 Mtb strains. CONCLUSIONS: We determined that a critical concentration of 20 µg per mL RFB was reliable for AST of Mtb.

Screening for potential biomarkers of traditional Chinese medicinechest impediment syndromesbased on plasma metabonomics / 中国药理学与毒理学杂志

OBJECTIVE To have a systematic pathomechanism view of three chest impediment-syndromes of Qi Deficiency and Blood Stasis syndrome(QDBS),Qi Stagnation and Blood Stasis syn-drome (QSBS), Cold Obstruction and Qi Stagnation syndrome(COQS) and further investigate the changed metabolome and related pathways for screening potential biomarkers in rat plasma. METHODS According to clinical pathogeny, three kinds of syndrome models were established to simulate the disease of chest impediment. Plasma metabonomics based on UPLC-Q-TOF/MS was applied in this research to detected small molecule metabolites for identifyingthe special potential biomarkers of three chest impediment syndromes, respectively. RESULTS Significant metabolic differences were observed between thecontrol group and three syndrome groups. Furthermore, three syndrome groups were distinguished clearly by pattern recognition method.The particular metabolites contributing most to the classification of three chest impediment syndromes were identified. In the QSBS group, the potential biomarkers could include 2-keto-glutaramic acid, L-methionine, L-homocysteic acid, octadecanamide, stearoylglycine,behenic acid,linoleylcarnitine,lysoPC(14:1(9Z)),indoxyl sulfate and cholic acid.In the COQS group, they could be aminoadipic acid, palmitic amide, oleamide, lysoPC(P-16:0), lysoPC(P-18:0), lysoPC(20:2(11Z,14Z)), 9-HETE and tauroursodeoxycholic acid. Moreover, 4-pyridoxic acid, L-palmi-toylcarnitine, lysoPC(20:0), lysoPC (22:5 (4Z,7Z,10Z,13Z,16Z)), 3- hydroxyhexadecanoic acid and arachidonic acid could be the potential biomarkers for the QDBS group. CONCLUSION Three chest impediment syndromes have their own potential biomarkers.Each special metabolite has its owndifferent metabolic pathway.Both metabolismof cysteine and methionine,and metabolism of alanine,aspartate and glutamate are the main pathways in regulation of metabolic disorders in QSBS syndrome. Lysine biosynthesis and degradation,fatty acid metabolism,and glycerophospholipid metabolism are the main pathways in regulation of metabolic disorders in COQS syndrome.Arachidonic acid metabolism, fatty acid metabolism,fatty acid elongation in mitochondria,and vitamin B6 metabolism are the main pathways in regulation of metabolic disorders in QDBS syndrome.These endogenous substances were indicated as the special potential biomarkers for three chest impediment syndromes and worth studying in depth.

Intermittent convulsions for 1.5 years and psychomotor retardation in a girl / 中国当代儿科杂志

The study reports a girl with pyridoxine-dependent epilepsy. The girl was admitted at the age of 2 years because of intermittent convulsions for 1.5 years and psychomotor retardation. She had a history of "hypoxia" in the neonatal period. At the age of 5 months recurrent epileptic seizures occurred. The child was resistant to antiepileptic drugs, and had many more seizures when she got cold or fever. She also had a lot of convulsive status epilepticus. No discharges were found during several video-EEG monitorings. Cerebral MRI examinations showed normal results. So Dravet syndrome was clinically suspected. ALDH7N1 gene mutation analysis revealed two heterozygote mutations, and pyridoxine-dependent epilepsy was thus confirmed. Seizures were generally controlled after pyridoxine supplementation.

Evaluation of Xpert MTB/RIF for the Diagnosis of Extrapulmonary Tuberculosis in China.

We evaluate the performance of Xpert MTB/RIF for the diagnosis of extrapulmonary tuberculosis (EPTB) in China. The performance of Xpert was evaluated compared to the composite reference standard (CRS), drug susceptibility testing (DST), and imaging examination. The overall sensitivity and specificity of Xpert were 64.1% (195/304) and 100% (24/24), respectively, using CRS as the gold standard. The sensitivity was significantly higher than that of culture for pus (P<0.05). The proportion of EPTB-positive cases diagnosed by imaging was two times more than that diagnosed using Xpert; however, 6 out of 19 cases may have been overdiagnosed by imaging. Compared to phenotypic DST, the sensitivity and specificity of Xpert were 80% (12/15) and 100% (75/75), respectively. Considering its high sensitivity and specificity, Xpert MTB/RIF may be used as a rapid initial test for EPTB diagnosis, and may also support a quicker decision on the treatment regimen. The combination of imaging and Xpert testing could provide high efficiency and accurate diagnosis of suspected EPTB.

The Clinical Features and Bacteriological Characterizations of Bone and Joint Tuberculosis in China.

Bone and Joint tuberculosis (BJTB) constitutes about 10% of total extra-pulmonary TB cases. Since the BJTB is a paucibacillary condition, there has been no systematic study on the bacterial characterization, especially the epidemiological feature. Here we collected the mycobacterial clinical isolates, analyzed the clinical features and the bacteriological characteristics from 113 BJTB cases reported in China. The mean age of the cases was 40.33 years while most of the patients fell into the 20-29 year age group; local pain was the most common onset symptom of BJTB cases; mean time from symptom onset to BJTB diagnosis was 13.16 months. 31 isolates were defined as drug resistant, including 15 multidrug resistant (MDR) and 2 extensively drug resistant (XDR) isolates according to the drug susceptibility test outcomes; after spoligotyping, 87.6% (99/113) isolates were categorized as Beijing family. In contrast to the isolates from pulmonary tuberculosis patients, here the MIRU-VNTR assay did not find anything significant. A prolonged time span for BJTB diagnosis highlights the requirement of paying further attention to BJTB infection in China. This study provides essential insights into the demographic and microbial characteristics of BJTB cases in China.

Mongoliicoccus roseus gen. nov., sp. nov., an alkaliphilic bacterium isolated from a haloalkaline lake.

Two pink, non-motile, aerobic, alkaliphilic, halotolerant, Gram-negative cocci, designated MIM28(T) and MIM29, were isolated from the surface water of a haloalkaline lake on the Mongolia Plateau. The isolates grew optimally at 30-33 °C, at pH 8-9 and with 3-4 % (w/v) NaCl. The isolates were chemoheterotrophic and could assimilate carbohydrates, organic acids and amino acids. The major respiratory quinone was menaquinone MK-7. The major polar lipids were phosphatidylcholine and phosphatidylethanolamine. The predominant cellular fatty acids were iso-C(15 : 0) (13.8-17.5 %), anteiso-C(15 : 0) (10.5-11.2 %), iso-C(16 : 0) (9.9-13.0 %), C(16 : 0) (4.3-4.6 %), iso-C(17 : 0) (3.8-5.3 %), anteiso-C(17 : 0) (3.7-7.1 %), C(17 : 1)ω6c (4.6-6.4 %), iso-C(17 : 0) 3-OH (4.6-5.8 %), summed feature 3 (C(16 : 1)ω7c and/or C(16 : 1)ω6c; 4.0-6.4 %) and summed feature 9 (iso-C(17 : 1)ω9c and/or C(16 : 0) 10-methyl; 10.4-12.5 %). Phylogenetic analysis based on 16S rRNA gene sequences showed that the isolates were most closely related to Litoribacter ruber YIM CH208(T) (93.6 % 16S rRNA gene sequence similarity), the genus Echinicola (90.4-92 %) and other members of the family Cyclobacteriaceae (87.8-90 %). The DNA G+C contents of strains MIM28(T) and MIM29 were 62.8 and 62.2 mol%. On the basis of morphology, physiology, fatty acid composition, phylogeny and 16S rRNA gene sequence analysis, the isolates are assigned to a novel species of a new genus, for which we propose the name Mongoliicoccus roseus gen. nov., sp. nov.; the type strain of the type species is MIM28(T) (= ACCC 05511(T) = KCTC 19808(T)).