2.A Core Genome Multilocus Sequence Typing Scheme for Proteus mirabilis.
Sheng Lin CHEN ; Yu Tong KANG ; Yi He LIANG ; Xiao Tong QIU ; Zhen Jun LI
Biomedical and Environmental Sciences 2023;36(4):343-352
OBJECTIVE:
A core genome multilocus sequence typing (cgMLST) scheme to genotype and identify potential risk clonal groups (CGs) in Proteus mirabilis.
METHODS:
In this work, we propose a publicly available cgMLST scheme for P. mirabilis using chewBBACA. In total 72 complete P. mirabilis genomes, representing the diversity of this species, were used to set up a cgMLST scheme targeting 1,842 genes, 635 unfinished (contig, chromosome, and scaffold) genomes were used for its validation.
RESULTS:
We identified a total of 205 CGs from 695 P. mirabilis strains with regional distribution characteristics. Of these, 159 unique CGs were distributed in 16 countries. CG20 and CG3 carried large numbers of shared and unique antibiotic resistance genes. Nine virulence genes ( papC, papD, papE, papF, papG, papH, papI, papJ, and papK) related to the P fimbrial operon that cause severe urinary tract infections were only found in CG20. These CGs require attention due to potential risks.
CONCLUSION
This research innovatively performs high-resolution molecular typing of P. mirabilis using whole-genome sequencing technology combined with a bioinformatics pipeline (chewBBACA). We found that the CGs of P. mirabilis showed regional distribution differences. We expect that our research will contribute to the establishment of cgMLST for P. mirabilis.
Genome, Bacterial
;
Proteus mirabilis/genetics*
;
Multilocus Sequence Typing
;
Molecular Epidemiology
;
Genotype
3.Genotyping Characteristics of Human Fecal Escherichia coli and Their Association with Multidrug Resistance in Miyun District, Beijing.
Wei Wei ZHANG ; Xiao Lin ZHU ; Le Le DENG ; Ya Jun HAN ; Zhuo Wei LI ; Jin Long WANG ; Yong Liang CHEN ; Ao Lin WANG ; Er Li TIAN ; Bin CHENG ; Lin Hua XU ; Yi Cong CHEN ; Li Li TIAN ; Guang Xue HE
Biomedical and Environmental Sciences 2023;36(5):406-417
OBJECTIVE:
To explore the genotyping characteristics of human fecal Escherichia coli( E. coli) and the relationships between antibiotic resistance genes (ARGs) and multidrug resistance (MDR) of E. coli in Miyun District, Beijing, an area with high incidence of infectious diarrheal cases but no related data.
METHODS:
Over a period of 3 years, 94 E. coli strains were isolated from fecal samples collected from Miyun District Hospital, a surveillance hospital of the National Pathogen Identification Network. The antibiotic susceptibility of the isolates was determined by the broth microdilution method. ARGs, multilocus sequence typing (MLST), and polymorphism trees were analyzed using whole-genome sequencing data (WGS).
RESULTS:
This study revealed that 68.09% of the isolates had MDR, prevalent and distributed in different clades, with a relatively high rate and low pathogenicity. There was no difference in MDR between the diarrheal (49/70) and healthy groups (15/24).
CONCLUSION
We developed a random forest (RF) prediction model of TEM.1 + baeR + mphA + mphB + QnrS1 + AAC.3-IId to identify MDR status, highlighting its potential for early resistance identification. The causes of MDR are likely mobile units transmitting the ARGs. In the future, we will continue to strengthen the monitoring of ARGs and MDR, and increase the number of strains to further verify the accuracy of the MDR markers.
Humans
;
Escherichia coli/genetics*
;
Escherichia coli Infections/epidemiology*
;
Multilocus Sequence Typing
;
Genotype
;
Beijing
;
Drug Resistance, Multiple, Bacterial/genetics*
;
Anti-Bacterial Agents/pharmacology*
;
Diarrhea
;
Microbial Sensitivity Tests
4.Analysis of the chloroplast genome of Incarvillea younghusbandii Sprague.
Yaying ZHANG ; Wanyao JIAO ; Wenrui JIAO ; Tianle QIAO ; Zhiyang SU ; Shuo FENG
Chinese Journal of Biotechnology 2023;39(7):2954-2964
Incarvillea younghusbandii Sprague is a traditional tonic herb. The roots are used as herbal medicine for nourishing and strengthening, as well as treating postpartum milk deficiency and weakness. In this study, the chloroplast genome of I. younghusbandii was sequenced and assembled by the high-throughput sequencing technology. The sequence characteristics, sequence repeats, codon usage bias, phylogenetic relationships and estimated divergence time of I. younghusbandii were analyzed. The 159 323 bp sequence contained a large single copy (80 197 bp), a small single copy (9 030 bp) and two inverted repeat sequences (35 048 bp). It contained 120 genes, including 77 protein coding genes, 8 ribosomal RNA genes and 35 transfer RNA genes. AAA was the most frequent codon in the chloroplast coding sequence of I. younghusbandii. A total of 42 simple sequence repeats were identified in the chloroplast genome. Phylogenetic analysis revealed I. younghusbandii was mostly like its taxonomically close relative Incarvillea compacta. The divergence between I. younghusbandii and I. compacta was dated to 4.66 million years ago. This study was significant for the scientific conservation and development of resources related to I. compacta. It also provides a basic genetic resource for the subsequent species identification of the genus Incarvillea, and the population genetic diversity study of Bignoniaceae.
Phylogeny
;
Molecular Sequence Annotation
;
Genome, Chloroplast
;
Sequence Analysis, DNA
;
Whole Genome Sequencing
5.Mitochondrial genome sequence characteristics and phylogenetic analysis of Schizothorax argentatus.
Yuping LIU ; Jianyong HU ; Zijun NING ; Peiyi XIAO ; Tianyan YANG
Chinese Journal of Biotechnology 2023;39(7):2965-2985
Schizothorax argentatus that only distributes in the Ili River basin in Xinjiang is one of the rare and endangered species of schizothorax in China, thus has high scientific and economic values. In this study, the complete mitochondrial genome sequence of S. argenteus with a length of 16 580 bp was obtained by high-throughput sequencing. The gene compositions and arrangement were similar to those of typical vertebrates. It contained 13 protein-coding genes, 22 tRNA genes, 2 rRNA genes, and a non-coding region (D-loop). The nucleotide compositions were A (30.25%), G (17.28%), C (27.20%), and T (25.27%), respectively, showing obvious AT bias and anti-G bias. Among the tRNA genes, only tRNA-Ser(GCU) could not form a typical cloverleaf structure due to the lack of dihydrouracil arm. The AT-skew and GC-skew values of the ND6 gene were fluctuating the most, suggesting that the gene may experience different selection and mutation pressures from other genes. The mitochondrial control region of S. argenteus contained three different domains, i.e., termination sequence region (ETAS), central conserved region (CSB-F, CSB-E, CSB-D, and CSB-B), and conserved sequence region (CSB1, CSB2, and CSB3). The conserved sequence fragment TT (AT) nGTG, which was ubiquitous in Cypriniformes, was identified at about 50 bp downstream CSB3. Phylogenetic relationships based on the complete mitochondrial genome sequence of 28 Schizothorax species showed that S. argenteus had differentiated earlier and had a distant relationship with other species, which may be closely related to the geographical location and the hydrological environment where it lives.
Animals
;
Genome, Mitochondrial/genetics*
;
Phylogeny
;
Sequence Analysis, DNA
;
Cyprinidae/genetics*
;
RNA, Transfer/genetics*
;
DNA, Mitochondrial/genetics*
;
Genes, Mitochondrial
6.A prospective study of genetic screening of 2 060 neonates by high-throughput sequencing.
Danyan ZHUANG ; Fei WANG ; Shuxia DING ; Zhoushu ZHENG ; Qi YU ; Lanqiu LYU ; Shuni SUN ; Rulai YANG ; Wenwen QUE ; Haibo LI
Chinese Journal of Medical Genetics 2023;40(6):641-647
OBJECTIVE:
To assess the value of genetic screening by high-throughput sequencing (HTS) for the early diagnosis of neonatal diseases.
METHODS:
A total of 2 060 neonates born at Ningbo Women and Children's Hospital from March to September 2021 were selected as the study subjects. All neonates had undergone conventional tandem mass spectrometry metabolite analysis and fluorescent immunoassay analysis. HTS was carried out to detect the definite pathogenic variant sites with high-frequency of 135 disease-related genes. Candidate variants were verified by Sanger sequencing or multiplex ligation-dependent probe amplification (MLPA).
RESULTS:
Among the 2 060 newborns, 31 were diagnosed with genetic diseases, 557 were found to be carriers, and 1 472 were negative. Among the 31 neonates, 5 had G6PD, 19 had hereditary non-syndromic deafness due to variants of GJB2, GJB3 and MT-RNR1 genes, 2 had PAH gene variants, 1 had GAA gene variants, 1 had SMN1 gene variants, 2 had MTTL1 gene variants, and 1 had GH1 gene variants. Clinically, 1 child had Spinal muscular atrophy (SMA), 1 had Glycogen storage disease II, 2 had congenital deafness, and 5 had G6PD deficiency. One mother was diagnosed with SMA. No patient was detected by conventional tandem mass spectrometry. Conventional fluorescence immunoassay had revealed 5 cases of G6PD deficiency (all positive by genetic screening) and 2 cases of hypothyroidism (identified as carriers). The most common variants identified in this region have involved DUOX2 (3.93%), ATP7B (2.48%), SLC26A4 (2.38%), GJB2 (2.33%), PAH (2.09%) and SLC22A5 genes (2.09%).
CONCLUSION
Neonatal genetic screening has a wide range of detection and high detection rate, which can significantly improve the efficacy of newborn screening when combined with conventional screening and facilitate secondary prevention for the affected children, diagnosis of family members and genetic counseling for the carriers.
Child
;
Infant, Newborn
;
Humans
;
Female
;
Prospective Studies
;
Connexins/genetics*
;
Connexin 26/genetics*
;
Glucosephosphate Dehydrogenase Deficiency
;
Mutation
;
Sulfate Transporters/genetics*
;
DNA Mutational Analysis
;
Genetic Testing/methods*
;
Deafness/genetics*
;
Neonatal Screening/methods*
;
Hearing Loss, Sensorineural/genetics*
;
High-Throughput Nucleotide Sequencing
;
Solute Carrier Family 22 Member 5/genetics*
7.Results of combined newborn hearing and deafness gene screening in Yuncheng area of Shanxi Province.
Hongqin HE ; Li SU ; Jia XU ; Yiwen WANG ; Yarong WANG ; Cui GUO ; Dandan LINGHU
Chinese Journal of Medical Genetics 2023;40(7):815-820
OBJECTIVE:
To analyze the clinical significance of combined newborn hearing and deafness gene screening in Yuncheng area of Shanxi Province.
METHODS:
Results of audiological examinations, including transient evoked otoacoustic emission and automatic discriminative auditory brainstem evoked potentials, for 6 723 newborns born in Yuncheng area from January 1, 2021 to December 31, 2021, were retrospectively analyzed. Those who failed one of the tests were considered to have failed the examination. A deafness-related gene testing kit was used to detect 15 hot spot variants of common deafness-associated genes in China including GJB2, SLC26A4, GJB3, and mtDNA12S rRNA. Neonates who had passed the audiological examinations and those who had not were compared using a chi-square test.
RESULTS:
Among the 6 723 neonates, 363 (5.40%) were found to carry variants. These have included 166 cases (2.47%) with GJB2 gene variants, 136 cases (2.03%) with SLC26A4 gene variants, 26 cases (0.39%) with mitochondrial 12S rRNA gene variants, and 33 cases (0.49%) with GJB3 gene variants. Among the 6 723 neonates, 267 had failed initial hearing screening, among which 244 had accepted a re-examination, for which 14 cases (5.73%) had failed again. This has yielded an approximate prevalence of hearing disorder of 0.21% (14/6 723). Among 230 newborns who had passed the re-examination, 10 (4.34%) were found to have carried a variant. By contrast, 4 out of the 14 neonates (28.57%) who had failed the re-examination had carried a variant, and there was a significant difference between the two groups (P < 0.05).
CONCLUSION
Genetic screening can provide an effective supplement to newborn hearing screening, and the combined screening can provide a best model for the prevention of hearing loss, which can enable early detection of deafness risks, targeted prevention measures, and genetic counseling to provide accurate prognosis for the newborns.
Infant, Newborn
;
Humans
;
Connexins/genetics*
;
Retrospective Studies
;
Deafness/genetics*
;
Connexin 26/genetics*
;
Neonatal Screening/methods*
;
Mutation
;
Genetic Testing/methods*
;
China/epidemiology*
;
Hearing
;
DNA Mutational Analysis
8.Drug resistance and genomic characteristics of Salmonella enterica serovar London from clinical and food sources in Hangzhou City from 2017 to 2021.
Zhi Bei ZHENG ; Hua YU ; Wei ZHENG ; Qi CHEN ; Xiu Qin LOU ; Xiao Dong LIU ; Hao Qiu WANG ; Jing Cao PAN
Chinese Journal of Preventive Medicine 2023;57(4):508-515
Objective: To analyze the drug resistance and genomic characteristics of Salmonella enterica serovar London isolated from clinical and food sources in Hangzhou City from 2017 to 2021. Methods: A total of 91 Salmonella enterica serovar London strains isolated from Hangzhou City from 2017 to 2021 were analyzed for drug susceptibility, pulsed field gel electrophoresis (PFGE) typing and whole genome sequencing. Multilocus sequence typing (MLST), core genome multilocus sequence typing (cgMLST) and detection of drug resistance genes were performed by using the sequencing data. Phylogenetic analysis was conducted to compare the 91 genomes from Hangzhou City with 347 genomes from public databases. Results: No significant difference in the drug resistance rate was observed between clinical strains and food strains to 18 drugs in Hangzhou City(all P>0.05), and the multidrug resistance (MDR) rate was 75.8% (69/91). Most strains were resistant to 7 drug classes simultaneously. One strain was resistant to Polymyxin E as well as positive for mcr-1.1, and 50.5% (46/91) of the strains were resistant to Azithromycin and were positive for mph(A). All 91 Salmonella enterica serovar London strains were ST155, which were subdivided into 44 molecular types by PFGE and 82 types by cgMLST. Phylogenetic analysis showed that most strains from Hangzhou City (83/91) were clustered together, and a small number of human isolates from Europe, North America and pork isolates from Hubei and Shenzhen were mixed in the cluster. Other strains from Hangzhou City (8/91) were closely related to strains from Europe, America and Southeast Asia. Strains isolated from pork were the most closely related to clinical strains. Conclusion: The epidemic of Salmonella enterica serovar London in Hangzhou City is mainly caused by the spread of ST155 strains, which is mainly transmitted locally. At the same time, cross-region transmission to Europe, North America, Southeast Asia, and other provinces and cities in China may also occur. There is no significant difference in the drug resistance rate between clinical strains and food strains, and a high level of MDR is found in the strains. Clinical infection of Salmonella enterica serovar London may be closely related to pork consumption in Hangzhou City.
Humans
;
Salmonella enterica/genetics*
;
Serogroup
;
Anti-Bacterial Agents/pharmacology*
;
Multilocus Sequence Typing
;
Cities
;
London
;
Clonidine
;
Phylogeny
;
Genomics
;
Drug Resistance
;
Electrophoresis, Gel, Pulsed-Field
;
Microbial Sensitivity Tests
9.Pathogenic characterization of Klebsiella pneumoniae resistant to carbapenems and polymyxin.
Xi CHEN ; Zhao Hui SUN ; Zhi Hui JIANG ; Yi Xue WU ; Zi Jing ZHU ; Li Dan CHEN
Chinese Journal of Preventive Medicine 2023;57(6):877-884
Objective: Analysis and investigation of pathogenic characteristics of polymyxin-and carbapenem-resistant Klebsiella pneumoniae (PR-CRKP). Methods: A total of 23 PR-CRKP strains isolated from clinical specimens from the General Hospital of Southern Theater Command from March 2019 to July 2021 were retrospectively collected, Whole-genome sequencing was performed on 23 PR-CRKP strains, resistance genes were identified by comparison of the CARD and the ResFinder database, high-resolution typing of PR-CRKP strains was analyzed by core genomic multilocus sequencing (cgMLST) and single nucleotide polymorphism (SNP); polymyxin resistance genes were determined by PCR and sequencing. Results: All PR-CRKP strains were KPC-2 producing ST11 types. cgMLST results showed that the evolutionary distance between the PR-CRKP strains and Klebsiella pneumoniae in mainland China was 66.44 on average, which is more closely related than foreign strains; the 23 PR-CRKP strains were divided into 3 main subclusters based on SNP phylogenetic trees, with some aggregation among Clade 2-1 in the isolation department and date. The two-component negative regulatory gene mgrB has seven mutation types including point mutations, different insertion fragments and different insertion positions. Conclusion: The close affinity of PR-CRKP strains indicate the possibility of nosocomial clonal transmission and the need to strengthen surveillance of PR-CRKP strains to prevent epidemic transmission of PR-CRKP.
Humans
;
Carbapenems/pharmacology*
;
Anti-Bacterial Agents/therapeutic use*
;
Klebsiella pneumoniae/genetics*
;
Polymyxins/pharmacology*
;
beta-Lactamases
;
Phylogeny
;
Retrospective Studies
;
Multilocus Sequence Typing
;
Microbial Sensitivity Tests
10.Study on the features of Clostridioides difficile infection among diarrhea patients in Kunming from 2018 to 2020.
Gui Man LI ; Wen Peng GU ; Min HOU ; Sen Quan JIA ; Yuan Yuan WANG ; Lu Lu BAI ; Jian Wen YIN ; Yong Ming ZHOU ; Xiao Qing FU ; Jin Xing LU ; Yuan WU
Chinese Journal of Epidemiology 2023;44(4):624-628
Objective: We analyze the characteristics of Clostridioides difficile (C. difficile) infection among diarrhea patients in Kunming from 2018 to 2020 and provide evidence for follow-up surveillance and prevention. Methods: A total of 388 fecal samples of diarrhea patients from four sentinel hospitals in Yunnan Province from 2018 to 2020 were collected. Real-time quantitative PCR was used to detect the fecal toxin genes of C. difficile. The positive fecal samples isolated the bacteria, and isolates were identified by mass spectrometry. The genomic DNA of the strains was extracted for multi-locus sequence typing (MLST). The fecal toxin, strain isolation, and clinical patient characteristics, including co-infection with other pathogens, were analyzed. Results: Among the 388 fecal samples, 47 samples with positive reference genes of C. difficile were positive, with a total positive rate of 12.11%. There were 4 (8.51%) non-toxigenic and 43 (91.49%) toxigenic ones. A total of 18 strains C. difficile were isolated from 47 positive specimens, and the isolation rate of positive specimens was 38.30%. Among them, 14 strains were positive for tcdA, tcdB, tcdC, tcdR, and tcdE. All 18 strains of C. difficile were negative for binary toxins. The MLST results showed 10 sequence types (ST), including 5 strains of ST37, accounting for 27.78%; 2 strains of ST129, ST3, ST54, and ST2, respectively; and 1 strain of ST35, ST532, ST48, ST27, and ST39, respectively. Fecal toxin gene positive (tcdB+) results were statistically associated with the patient's age group and with or without fever before the visit; positive isolates were only statistically associated with the patient's age group. In addition, some C. difficile patients have co-infection with other diarrhea-related viruses. Conclusions: The infection of C. difficile in diarrhea patients in Kunming is mostly toxigenic strains, and the high diversity of strains was identified using the MLST method. Therefore, the surveillance and prevention of C. difficile should be strengthened.
Humans
;
Bacterial Toxins/genetics*
;
Enterotoxins/genetics*
;
Clostridioides difficile/genetics*
;
Multilocus Sequence Typing
;
Coinfection
;
Bacterial Proteins/genetics*
;
China/epidemiology*
;
Clostridium Infections/epidemiology*
;
Diarrhea/microbiology*

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