The methodological comparison of Pandoraea sputorum identification / 中华检验医学杂志

Objective:The matria-assisted laser desorption/ionization time of flight mass spectrometry(MALDI-TOF MS) and sequencing methods were performed to assess the methodology (biochemistry methods) for identifying the Pandoraea sputorum and provide the more preferred approach to identify Pandoraea species. Methods:This paper is a study on performance evaluation of identification method. Ten lines of Pandoraea sputorum were isolated from blood cultures of inpatients were collected at Zhongnan Hospital of Wuhan University from July to October 2018 and were confirmed by the cultural characteristics, colonial morphology and Gram′s stain. Further identification was carried out by using the manual biochemical method (API 20NE), automatic biochemistry systems(BioMerieuxVITEK 2 Compact, BD Phoenix-100andThemo ARIS 2X), MALDI-TOF MS (BioMerieuxVITEK MS and Bruker MALDI Biotyper) and the sequencing methods of the 16S rRNA to identify the Pandoraea sputorum. Results:Pandoraea sputorum was non-fermented gram-negative bacteria that are non-motile, oxidase positive, and catalase positive. Ten lines of Pandoraea sputorum were identified as Achromobacter denitrificans, Alcaligenes faecalis or Cupriavidus pauculus and the accuracy rate of genus and species identification was 0 by API 20NE. Among all the samples, six lines were identified as the Pandoraea spp. with the accuracy rate of genus identification was 6/10 by VITEK 2 Compact; whereas the other four lines were identified as the Burkholderia cepacia, Sphingomonas paucimobilis, Ralstonia pickettii, or "Low Discrim" . All of these were identified as "No Identification" by Phoenix-100, which the accuracy rate of genus and species identification was 0. Seven isolates were identified by ARIS 2X as Stenotrophomonas maltophilia, Acinetobacter lwoffii, Sphingomonas paucimobilis, Pseudomonas luteola, Acinetobacter baumannii/Acinetobacter haemolyticus; whereas the other three lines were identified as rare species, thus, the accuracy rate of genus and species identification was 0. Both VITEK MS and MALDI Biotyper indicated all the isolates were Pandoraea sputorum with the accuracy rate of genus and species identification was 10/10. 16S rRNA sequencing for the 10 isolates showed they have 100% of similarity to Pandoraea sputorum by blasting with Genebank. Conclusions:Methods based on biochemical reactions often failed to accurately identify the Pandoraea sputorum to species level. MALDL-TOF MS and 16S rRNA sequencing technology identify Pandoraea sputorum efficiently and precisely enough.

The phenotypes of a hypercholesterolemia family with low density lipoprotein receptor exon 13 A606T mutation / 中华内科杂志

ObjectiveTo investigate the clinical phenotypes of familial hypercholesterolemia (FH) caused by exon 13 A606T mutation in low deusity lipoprotein receptor.MethodsClinical data of the suffered family were collected and analyzed,as well as measurement of perivascular intima-medial thickness and follow-mediated-dilation function by ultrasonography.ResultsThere were totally 11 sufferers including 4 males and 9 females,aged 8-90 years,with 2 homozygotes and 9 heterozygotes.Among them, one homozygote showed angina pectoris and hematuria,both homozygotes had skin xanthomata.TC,TG,LDL-C and HDL-C were(7.39 ± 1.30) mmol/L,(0.93 ± 0.36) mmol/L,( 11.76 ± 1.10) mmol/L and ( 1.22 ±0.17) mmol/L,respectively.The left/right sided intima-medial thickness of the common,internal,external and bulb carotid artery were ( 1.15 ±0.45) mm/( 1.30 ±0.60) mm,(0.82 ±0.30) mm/( 1.00 -0.66)mm,(0.77 ±0.28) mm/(0.78 ±0.30) mm and ( 1.40 ±0.59) mm/( 1.46 ±0.71 ) mm respectively.The brachial artery flow mediated dilation rate was (4.85 ±4.80)％.Echocardiography revealed 2 patients with cardiac valvular disease and 3 with atrium septum aneurysm. ConclusionFH patients show a variety of phenotypes incuding extraordinary hypercholesterolemia,subcutaneous xanthomata and premature coronary heart disease.

Gene mutations in low-density lipoprotein receptor in one Chinese padigree with homozygous familial hypercholesterolemia / 中华检验医学杂志

Objective To investigate low density lipoprotein receptor (LDLR)gene mutation in familial hypercholesterolemia (FH) patients. Methods The proband was given clinical diagnosis of homozygous FH based on marked features and blood lipid tests results. After apoB100R3500Q mutation was excluded, the promoter region and all of the 18 exons of LDLR gene were amplified by touch-downpolymerase chain reaction (PCR). The PCR products were analyzed by single-strand conformationalpolymorphism (SSCP). The PCR products with abnormal single strands were sequenced directly. Thesecondary structures of the mutational and wild type proteins were analyzed and compared byANTHEPROT5.0, and then the tertiary structures of the mutant and wild type LDLR were predicted atSWISS MODEL homepage online. Results A homozygous mutation A606T at exon 13 of the patients wasfound by SSCP and confirmed by DNA sequencing. GOR Ⅰ method in ANTHEPROT5.0 indicates that therandom coils and turns would replace some helixes at the mutation site. The online prediction from theSWISS MODEL homepage indicates the backbone structure of the mutant LDLR has no difference from thewild type one. Conclusion The results suggest the A606T mutation of LDLR gene is the cause of the FH inthis pedigree.