1.Identification for medically important yeast-like fungal species by sequence analysis of 18S rRNA gene
Jiajing GENG ; Liang YUAN ; Xinxin LU
Chinese Journal of Laboratory Medicine 2009;32(6):644-648
Objective To compare sequence analysis of the yeast-like fungal isolates with traditional methods and analyze the feasibility of identification of common yeast-like fungal by sequence analysis of gene. Methods 115 yeast-like fungal isolates were collected in the clinical laboratory of Beijing Tongren Hospital. DNA of yeast-like fungal was extracted and then amplified with universal primers of part of 18S rRNA genes followed by sequencing directly. The sequences obtained were submitted to the GenBank (NCBI) to identify the fungi. At the same time, the CHROMagar Candida and Vitek 32 YBC were used to identify the fungi. The identification accuracy with three methods was compared to explore the feasibility of the identification of sequence analysis. Results 18S rRNA gene sequence analysis was compared with traditional method. There were some differences in the identification results of 13 strains. The coincidence rate between CHROMagar Candida and sequence analysis was 89. 2% (91/102) and the coincidence rate between Vitek 32 YBC and sequence analysis was 91.3% (105/115). The positivity rate of species-level identification by CHROMagar Candida , Vitek 32 YBC and the 18S rRNA gene sequence analysis were 88. 7 % ( 102/115 ), 100% ( 115/115 ), 100% ( 115/115 ). Conclusion Identification of medically important yeast-like fungal by sequence analysis of the 18S rRNA gene is reliability.
2.CT differential diagnosis of fnngal ball in paranasal sinus caused by different mycotic pathogenic agents
Xiaoli CHEN ; Zhenchang WANG ; Xinxin LU ; Junfang XIAN ; Jing LI ; Jiajing GENG
Chinese Journal of Radiology 2012;46(7):611-614
ObjectiveTo evaluate CT characteristics of fungal ball in paranasal sinus caused by different fungi and to enhance differential diagnosis.MethodsCT results and clinical data of 74 patients with fungal ball arising from the paranasal sinuses proved by histopathology from 2007 to 2009 were analyzed retrospectively.The CT characteristics of fungal ball in paranasal sinus caused by different fungi were compared using x2 test with P < 0.05 considered statistically significant.Results Among 74 mycotic pathogenic agents,aspergillus was found in 58 cases (including 36 cases with aspergilhs flavus,15 cases with aspergillus fumigatus and 7 with aspergillus versicolor),the others including 5 cases with penicillium,6 cases with schizophyllum commune,and 5 cases with scedosporium apiospermum.There were significant differences in the number of sinus involved ( single sinus involvement was seen in 29 cases caused by aspergillus group and 2 cases caused by non-aspergillus-group,respectively,with x2 =7.245,P =0.007 ),the incidence of fungus ball in ethmoid sinus [ 39.7% ( 23/58 ) of cases caused by aspergillus group and 81.3 % ( 13/16 ) of cases caused by non-aspergillus-group,respectively,with x2 =8.685,P =0.003 ] and calcification (40 of 58 cases caused by aspergillus group and 5 of 16 cases caused by non-aspergillus-group,respectively,with x2 =7.485,P =0.006 ),the location of calcification ( 26 of 40 cases with central calcification and 14 of 40 cases with peripheral calcification in cases caused by aspergillus group,while all of 5 cases caused by non-aspergillus-group with peripheral calcification,x2 =7.697,P =0.006).However,there was no significant difference in the incidence of bilateral lesions ( x2 =1.002,P =0.317 ),maxillary sinus involvement ( x2 =0.020,P =0.888 ),sphenoidal sinus involvement ( x2 =0.704,P =0.401 ),frontal sinus involvement ( x2 =0.126,P =0.723 ),bony sclerosis ( x2 =2.024,P =0.155 ),lamellar calcification (x2 =2.045,P =0.153 ),complication of nasal polyps( x2 =0.018,P =0.893) and submucosal cyst( x2 =0.779,P =0.378 ).ConclusionsThe common CT characteristics of fungal ball in paranasal sinus are unilateral sinus involvement with inhomogeneous high-density soft tissue and lamellar calcification.The CT findings of fungal ball caused by non-aspergillus-group are ethmoid sinus involvement and calcification located on the periphery instead of the center of fungal ball.
3.The clinical application of identification of Aspergillus spp.using ITS and β-tubulin gene sequences
Min ZHU ; Jiajing GENG ; Mei WANG ; Yanfei HUANG ; Lijun WANG ; Xinxin LU
Chinese Journal of Laboratory Medicine 2011;34(4):353-357
Objective To study the clinical application of the ITS and β-tubulin gene regions in identification of Aspergillus spp. Methods One hundred and twenty-four Aspergillus strains that isolated from fungal rhino-sinusitis specimens were collected in Beijing Tongren Hospital, Capital Medical University from July 2007 to January 2010. They were identified by morphological and molecular methods. The first one included traditional culture, slide culture, and microscopic examination after lactophenol cotton blue stain and KOH digestion. The second one was amplifying and sequencing the part of ITS and β-tubulin gene and aligned all the sequences in the GenBank, European Molecular Biology Laboratory nucleotide sequence database, and DNA Data Bank of Japan. Results Of the 56 Aspergillus flavus identified by morphological features, fifty-five isolates were identified as Aspergillus flavus and 1 isolates was Aspergillus parasiticus by the ITS and β-tubulin gene region sequence analysis. In the 37 Aspergillus fumigatus identified by morphological method, and all the 37 isolates were identified as species complex of Aspergillus fumigatus by the ITS region sequence analysis, but through the sequence analysis of β-tubulin gene region, thirty-five isolates were identified as Aspergillus. fumigatus and 2 were Aspergillus lentulus. Twenty-one isolates were identified as Aspergillus versicolor by morphological method, but 16 of them were identified as Aspergillus. versicolor and 5 can not be identified to species level by the ITS region sequence. And by comparative-sequence analysis of β-tubulin gene region, the 5 isolates were identified as Aspergillus sydowii,the other 16 isolates were Aspergillus. versilcolor. Ten isolates were identified as Aspergillus nidulans by morphological features, the ITS and β-tubulin gene region sequence analysis. Conclusions β-tubulin gene sequencing is more suitable for identifying Aspergillus, and could identify Aspergillus spp. to species level Sequences of ITS region could only identify Aspergillus spp. to species complex.
4.Evaluation of ITS region sequencing strategy for the identification of the pathogenic fungi from fungal sinusitis tissues
Xinxin LU ; Jiajing GENG ; Yunchuan LI ; Bing ZHOU ; Liang WAN ; Xiangdong WANG ; Zi ZHANG ; Demin HAN
Chinese Journal of Laboratory Medicine 2010;33(2):126-131
Objective To establish a molecular technique of internal transcribed spacer (ITS) sequencing to identify pathogenic fungi species from the fungal sinusitis tissues. Methods Total 270 sinusitis tissues samples were collected by endoscopic surgery from 2006 to 2008. The histopathology, organize spring clip culturation and ITS region (ITS region region of fungal rRNA, including ITS1-5. 8S rRNA-ITS2) sequencing were employed simultaneously. And then to evaluate the ITS sequencing as the tool for identification of pathogenic fungi directly from clinical samples. Results Of the 270 samples, histopathology positive rate was 80.0% (216/270) , organize spring clip positive rate was 80.0% (216/ 270), fungal culturation positive rate was 53.0% (143/270) , ITS region sequencing positive rate was 63. 0% [ (134 +28 +8)/270], There were 22 species and 6 genera identified by fungal culturation, and 32 species identified by ITS region sequencing. Conclusion ITS region sequencing will become a applicable tool in clinical laboratory in future.