RURAL LEFT-BEHIND CHILDREN ARE SERIOUSLY AFFLICTED WITH INTESTINAL HELMINTH INFECTIONS IN SOUTHERN SICHUAH, CHINA.

Rural children are seriously afflicted with intestinal helminth infections in China. Of note, the term rural children includes rural left-behind children (LBC) and rural non-left-behind children (NLBC); the difference in the prevalence of intestinal helminths between the 2 groups remains unclear. In this study, Gulin and Xuyong counties in southern Sichuan were chosen for investigation in 2019. The Kato Katz thick smear method was used to detect the presence of intestinal helminth eggs in rural children. For children aged 3-6 yr, the adhesive tape perianal swab method was used to detect Enterobius vermicularis and tapeworm eggs. Statistical differences in infection rates between the 2 groups were determined by the chi-square test. In total, 1,608 rural children, 911 LBC and 697 NLBC, participated in the investigation. Six species of intestinal helminths were detected. A total of 358 (39.3%) and 130 (18.7%) intestinal helminth positives were found among LBC and NLBC, respectively; the former had a higher (P < 0.05) infection level. Moreover, an analysis of double worm infection rates among intestinal helminth positive LBC and NLBC showed a difference between the 2 groups that was also statistically significant. These surveys indicated that the risk of intestinal helminth infection was substantially higher and the severity of infection much worse in rural LBC in southern Sichuan. More attention should be paid to the parasitic infection of LBC.

Mechanism of the Passage of Angiostrongylus cantonensis across the Final Host Blood-Brain Barrier Using the Next-Generation Sequencing.

BACKGROUND: Multicellular parasites Angiostrogylus cantonensis larvae develop in the final host rat brain at the fourth stage (L4) and migrate to the lungs by the adult stage. The potential mechanism of its blood-brain barrier (BBB) passage remains unclear. METHODS: By using Illumina Hiseq/Miseq sequencing, we obtained the transcriptomes of 3 groups of adult males and 3 groups of female of A. cantonensis to generate similarly expressed genes (SEGs) between 2 genders at the adult stage. Next 2 groups of L4 expressed genes were used to compared with SEGs to create differentially expressed genes (DEGs) between 2 life stages to unlock potential mechanism of BBB passage. RESULTS: In total, we obtained 381 581 802 clean reads and 56 990 699 010 clean bases. Of these, 331 803 unigenes and 482 056 transcripts were successfully annotated. A total of 3 166 DEGs between L4 and adults SEGs were detected. Annotation of these DEGs showed 167 were down-regulated and 181 were up-regulated. Pathway analysis exhibited that calcium signaling pathway, the ECM-receptor interaction, focal adhesion, and cysteine and methionine metabolism were highly associated with DEGs. The function of these pathways might be related to BBB traversal, as well as neuro-regulation, interactions between parasite and host, environmental adaption. CONCLUSION: This study expanded the regulatory characteristics of the two important life stages of A. cantonensis. This information may provide a better appreciation of the biological features of the stages of the parasitic A. cantonensis.

Why do we lack a specific magic anti-COVID-19 drug? Analyses and solutions.

The Coronavirus 2019 (COVID-19) pandemic represents the greatest worldwide public health crisis of recent times. The lack of proven effective therapies means that COVID-19 rages relatively unchecked. Current anti-COVID-19 pharmacotherapies are drugs originally designed for other diseases, and administered orally or intravascularly. Thus, they can have various adverse effects. A specific anti-Coronavirus drug should not only target the virus per se, but also treat the related respiratory and cardiovascular symptoms. Here, we examine the advantages and disadvantages of current anti-COVID-19 pharmacotherapies, and analyze the reasons why in the era of big data we have not yet established specific coronavirus therapies and related technical bottlenecks. Finally, we present our design of a novel nebulized S-nitrosocaptopril that is under development for targeting both coronaviruses and their related symptoms.

Main Pathways and Ion Channels Differentially Expressed in the Transcriptome of Male and Female Adult Angiostrongylus cantonensis Using a Deep Sequencing Approach.

BACKGROUND: The adult stage is an important period in the life cycle of Angiostrongylus cantonensis, as it is at this stage that male and female worms produce thousands of fertilized eggs daily. METHODS: To explore the transcriptional details of adult male and female A. cantonensis, three groups of male and female adult worms were collected, and their transcriptome profiles were analyzed using an Illumina next-generation sequencing platform. A total of 283,910,174 clean reads were obtained, and 137,626 unigenes and 237,059 transcripts were then generated. Unigenes were successfully annotated by querying the Gene Ontology (GO), the Kyoto Encyclopedia of Genes and Genomes (KEGG), NCBI non-redundant protein sequences (NR), PFAM, STRING, and SWISS-PROT databases. Then, differentially expressed genes (DEGs) between the 2 genders were identified. The GO and KEGG databases were used for DEG annotation, and a number of DEG annotations were enriched. RESULTS: The results obtained from querying DEGs using the GO and KEGG databases revealed that male and female adult worms exhibited differences in metabolism and production. Protein phosphorylation, ion transport, and calcium transport were all significantly enriched according to GO annotation. A number of other pathways were also enriched according to KEGG enrichment annotation, including the pentose phosphate pathway, nitrogen metabolism, oocyte meiosis pathway, neuroactive ligand-receptor interaction, calcium signaling pathway, transforming growth factor ß (TGF-ß) signaling pathway etc. CONCLUSION: We hypothesized that the nervous system of the worm plays a key role in the physiological regulation of adult A. cantonensis, and based on this, the function of the calcium-signaling pathway should be investigated.

Next-Generation Sequencing Reveals That Oxidative Phosphorylation Might Be a Key Pathway Differently Expressed in the Third and Fourth Stages Larvae of Angiostrongylus cantonensis.

BACKGROUND: When Angiostrongylus cantonensis develops from the third and fourth stage, it needs to change its host from the middle host, snail to the final host, rat. However, the mechanism involved in this change remains unclear. METHODS: The transcriptome differences of the third and fourth stages of A. cantonensis were explored by next-generation Illumina Hiseq/Miseq sequencing in China, in 2018. RESULTS: Overall, 137 956 488 clean reads and 20 406 213 373 clean bases of the two stages larvae were produced. Based on the queries against the Gene Ontology (GO), NCBI non-redundant protein sequences (Nr), Swissprot, and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases, 14 204 differentially expressed genes (DEGs) were predicted. GO enrichment analysis revealed 5660 DEGs with the top s categories as followings: biological process (GO:0008150, related to 5345 DEGs), cellular component (GO:0005575, related to 5297 DEGs), molecular function (GO:0003674, related to 5290 DEGs). In KEGG enrichment analysis, 116 genes were related to oxidative phosphorylation and 49 genes involved in the glycolytic process. CONCLUSION: Metabolism changes, especially oxidative phosphorylation and glycolysis, might play a key role in A. cantonensis infection of its final rat host. Many other pathways might also contribute to the transcriptome changes between these two life stages. Overall, additional studies are needed for further details.

Analysis and recognition of characteristics of digitized tongue pictures and tongue coating texture based on fractal theory in traditional Chinese medicine.

Simple fractal dimensions have been proposed for use in the analysis of the characteristics of digitized tongue pictures and tongue coating texture, which could further the establishment of objectified classification criteria under the conditions of expanding sample size. However, detailed descriptions on simple fractal dimensions have been limited. Therefore, BP (back propagation) neural network model classifiers could be designed by further calculation of the multiple fractal spectrum characteristics of digitized tongue pictures in order to classify and recognize the thin/thick or greasy characteristics of tongue coating. The fractal dimensions of sample data of 587 digitized tongue pictures were collected in a standard environment. A statistical analysis was conducted on the calculation results of the sample data, and the sensitivity of the fractal dimensions to the thin/thick and greasy characteristics of digitized tongue pictures was observed. As the overlap region resulted from a range of values of a single parameter, another 8 characteristic parameters of the multiple fractal spectra of the digitized tongue pictures were further proposed as the elements in the input layer of the three-layers BP neural network. Automatic recognition classifiers were designed and trained for the characteristics of digitized tongue pictures and tongue coating textures. The simple fractal dimension was sensitive to the thin/thick and greasy characteristics of digitized tongue pictures and could better judge the characteristics of the thickness of the tongue coating. A classifier with characteristic parameters of multiple fractal spectra as the input vectors identified by the BP neural network models could effectively increase the accuracy rate judged by the characteristics of the tongue coating texture.

New Nodule Type Found in the Lungs of Pomacea canaliculata, an Intermediate Host of Angiostrongylus cantonensis.

BACKGROUND: Pomacea canaliculata (P.canaliculata) lung nodules, were commonly caused by Angiostrongylus cantonensis infection. Here, we found a new nodule type without any parasites. METHODS: Overall, 447 P. canaliculata snails were collected in Ning Bo, Zhe Jiang, China in 2018. In order to exhibit the similarities and differences between two nodules types (2018, Huzhou Zhejiang, China), both types were collected in formalin for tissue pathological sectioning. Besides, to obtain the microbial community of the new nodule, the 18S ribosomal RNA (rRNA) gene of it was amplified and analyzed using the Illumina second-generation sequencing platform. RESULTS: Although two nodules were found in the lungs of P. canaliculata, they were different in shape and pathology. Illumina sequencing indicated Poterioochromonas sp., a species of golden algae, might be the causing agent of the new nodule. CONCLUSION: We firstly found a new pathological nodule type in the lungs of P. canaliculata, and this nodule might be induced by golden algae infection, however, the direct link between the golden algae and the new nodules, as well as the nodules' impact on the snails' physiology and A. cantonensis infection require further study.

Immunomagnetic antibody plus aptamer pseudo-DNA nanocatenane followed by rolling circle amplication for highly-sensitive CTC detection.

Biosensing and detecting the rare circulating tumor cells (CTCs) in complex blood samples are a great challenge but necessary for cancer metastasis prevention. Here we show a novel highly-sensitive biosensing system for detecting CTCs in whole blood. The system is composed of Her2-coated immunomagnetic beads and an anti-EpCAM aptamer assembled pseudo-DNA nanocatenane (PDN) for dual targeting and separating CTCs, in conjunction with the rolling circle amplification (RCA) and molecular beacon (MB) system for CTCs signal amplification. The Her-2-coated beads separated CTCs from blood after their elution from a magnetic column. The unique PDN, which is a tailor-designed self-assembly of three circular DNAs that are inter-locked with independent and non-interfered templates for periodic RCA process, binds EpCAM-rich CTCs. In the presence of the RCA primer, phi29 DNA polymerase and MB, the system collaboratively generated the amplified fluorescent signals for highly-sensitive detection of CTCs. Through this system, we achieved the limit of detection less than 10 CTCs/mL blood, and quantified the number of CTCs in patient blood, which is proportional to the patient cancer status. Our technique is highly-sensitive, practicable and convenient enough for clinical detection of breast CTCs.

A Retrospective Study of Culture-confirmed Mycobacterial Infection among Hospitalized HIV-infected Patients in Beijing, China.

A retrospective analysis was performed in two major HIV/AIDS referral hospitals in Beijing to evaluate the prevalence of Mycobacterium tuberculosis (MTB) and non-tuberculous mycobacterial (NTM) infections in HIV-infected patients. A total of 627 patients' data were reviewed, and 102 (16.3%) patients were diagnosed with culture-confirmed mycobacterial infection, including 84 with MTB, 16 with NTM, and 2 with both MTB and NTM. The most frequent clinical complication by mycobacterial infection was pulmonary infection (48/102, 47.1%). The overall rates of multidrug-resistant TB (MDR-TB) and extensively drug-resistant TB (XDR-TB) were 11.9% and 3.4%, respectively. This study underlines the urgent need to intensify screening for mycobacteria coinfection with HIV and to prevent the spread of drug-resistant TB among HIV-infected patients.

Bid-Induced Release of AIF/EndoG from Mitochondria Causes Apoptosis of Macrophages during Infection with Leptospira interrogans.

Leptospirosis is a global zoonotic infectious disease caused by pathogenic Leptospira species. Leptospire-induced macrophage apoptosis through the Fas/FasL-caspase-8/3 pathway plays an important role in the survival and proliferation of the pathogen in hosts. Although, the release of mitochondrial apoptosis-inducing factor (AIF) and endonuclease G (EndoG) in leptospire-infected macrophages has been described, the mechanisms linking caspase and mitochondrion-related host-cell apoptosis has not been determined. Here, we demonstrated that leptospire-infection induced apoptosis through mitochondrial damages in macrophages. Apoptosis was caused by the mitochondrial release and nuclear translocation of AIF and/or EndoG, leading to nuclear DNA fragmentation. However, the mitochondrion-related CytC-caspase-9/3 pathway was not activated. Next, we found that the release and translocation of AIF and/or EndoG was preceded by the activation of the BH3-interacting domain death agonist (Bid). Furthermore, our data demonstrated that caspase-8 was activated during the infection and caused the activation of Bid. Meanwhile, high reactive oxygen species (ROS) trigged by the infection caused the dephosphorylation of Akt, which also activated Bid. In conclusion, Bid-mediated mitochondrial release of AIF and/or EndoG followed by nuclear translocation is a major mechanism of leptospire- induced apoptosis in macrophages, and this process is modulated by both caspase-8 and ROS-Akt signal pathways.

Molecular Typing Characteristic and Drug Susceptibility Analysis of Mycobacterium tuberculosis Isolates from Zigong, China.

China is one of the 22 countries with high TB burden worldwide, and Sichuan contained the second-largest number of TB cases among all of the Chinese provinces. But the characteristics of Mycobacterium tuberculosis circulated in Zigong, Sichuan, were still unknown. To investigate the character and drug resistance profile, 265 clinical isolates were cultured from tuberculosis patient's sputum samples in the year of 2010, of which the genetic profile was determined by using Spoligotyping and MIRU-VNTR typing methods, and the drug sensibility testing to the four first-line and four second-line antituberculosis (anti-TB) drugs was performed by using proportion method on Lowenstein-Jensen (L-J) media. The major Spoligotype was Beijing family (143/265, 53.96%), followed by T (80/265, 30.19%) and H (9/265, 3.40%) genotypes; the total Hunter-Gaston discrimination index (HGDI) of the 24 loci MIRU-VNTR was 0.9995. About 27.17% (72/265) of the isolates were resistant to at least one of the eight tested anti-TB drugs, and for Beijing and non-Beijing family isolates the proportion of drug resistance was 28.47% (41/144) and 25.62% (31/121), respectively. That is, the most prevalent genotype here was Beijing family, and the 24 loci VNTR analysis could supply a high resolution for genotyping, and Beijing and non-Beijing isolates had no difference (p > 0.05) for drug resistance.

Pancreatic Stent or Rectal Indomethacin-Which Better Prevents Post-ERCP Pancreatitis?: A Propensity Score Matching Analysis.

We investigated and compared 2 clinical strategies to prevent postendoscopic retrograde cholangiopancreatography (ERCP) pancreatitis (PEP).We retrospectively reviewed data from patients who underwent ERCP between 2008 and 2014. Of 623 patients at high risk for PEP, 145 were treated with prophylactic pancreatic stent placement (PSP) only, and 478 were treated with rectal indomethacin (RI) only, for PEP prevention. Patients were matched by one-to-one propensity score matching (PSM) by risk factors, with overall PEP incidence as primary outcome, and moderate or severe PEP and complication rates as secondary outcomes.Of 623 patients with high-risk factors, 145 pairs were generated after PSM. Thirty-two patients developed pancreatitis-10 (6.9 %) in the PSP group and 22 (15.2 %) in the RI group (P = 0.025). Moderate-to-severe pancreatitis developed in 5 patients (2.8%) in the PSP group and 14 patients (9.7 %) in the RI group (P = 0.047).Although indomethacin represents an easy, inexpensive treatment, prophylactic PSP is still the better prevention strategy for PEP.

[A bite of parasite, experiences of application of documentaries into parasitology class teaching].

Medical parasitology education has been facing some difficulties, because it is a course of wide range, lacking clinical cases and concerned specimens of parasites currently. In addition, its relationship with life is not closely enough. All these reasons may impact the effect of class education negatively. Therefore, it is important to increase the vitality of parasitology education and diversify the instructional mode by using the resources from Internet. In recent years, the Discovery Channel has uploaded a documentary Monsters Inside Me online. This documentary is high professional and closely linked with parasitology. It maintains numbers of clinical cases about parasitic diseases. Each episode is about 3 minutes and shortly enough to be introduced into class teaching. However, this resource has not been fully used in domestic temporally. We found that direct introduction of the documentary into class teaching can enrich teaching forms to attract learning interest of students, and finally improve the teaching effect of class. Above that, another popular documentary A Bite of China involves many related knowledge points of parasitology. The appropriate usage of the knowledge can build up close linkage between book and life, which is extremely helpful to give students a deep impression of parasitology. In brief, it is our strong recommendation to introduce the documentary Monsters Inside Me into class.

Multicenter Evaluation of the Molecular Line Probe Assay for Multidrug Resistant Mycobacterium Tuberculosis Detection in China.

In order to evaluate the performance of a molecular Hain line probe assay (Hain LPA) for rapid detection of rifampicin and isoniazid resistance of Mycobacterium tuberculosis in China, 1612 smear positive patients were consecutively enrolled in this study. Smear positive sputum specimens were collected for Hain LPA and conventional drug susceptibility testing (DST). The sensitivity and specificity of Hain LPA were analyzed by using conventional DST as golden reference. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) for rifampicin resistance detection were 88.33%, 97.66%, 81.54%, and 98.62%, respectively. The sensitivity, specificity, PPV and NPV for isoniazid resistance detection were 80.25%, 98.07%, 87.25%, and 96.78%, respectively. These findings suggested that Hain LPA can be an effective method worthy of broader use in China.

Prevalence of drug resistant Mycobacterium tuberculosis among children in China.

The available data on the epidemic of drug resistant tuberculosis (TB) among children in China is limited. This study attempted to clarify the drug resistance profiles of clinical strains isolated from children and estimate risk factors related to acquisition of drug resistance. All Mycobacterium tuberculosis strains from children (age <15 years) and adolescent (age 15-18 years) TB patients received in the strain library of Chinese Center for Disease Control and Prevention between January 2005 and December 2012 were included in the study. A study collection included 450 clinical isolates (100 from children, 159 from adolescents, and 191 from adults) from all over China. Drug susceptibility testing was performed by a proportion method. As a result, the drug resistance and multi-drug resistance (MDR) rates in children were 55% (55/100) and 22% (22/100), respectively. In children with MDR-TB, new cases accounted for 40.9% (9/22). Compared with adults, the drug resistance rates were similar in all subgroups (new cases, previously treated cases and all cases) of children (P > 0.05), except for the lower resistance rate to isoniazid in total cases of children (P = 0.011). Patient related information was included in the MDR-TB association analysis. The treatment history was found to be strongly associated with MDR-TB in all three age groups (P < 0.05). Our results demonstrate that the prevalence of drug resistant TB in children in China is alarmingly high and similar to that seen in adults. In contrast, in adolescents, the drug resistance rate to most tested drugs was lower than in adults. Primary transmission and inadequate treatment are two equally important factors for the high MDR-TB rate in children. Thus, major efforts in the TB control in children should focus on decreasing the transmission of drug resistant TB and early testing of drug resistance.

Modified laparoscopic intragastric surgery and endoscopic full-thickness resection for gastric stromal tumor originating from the muscularis propria.

BACKGROUND: This study aimed to evaluate the feasibility and security of the modified laparoscopic intragastric surgery (MLIGS) and the endoscopic full-thickness resection (EFR) for the treatment of gastric stromal tumors (GSTs) originating from the muscularis propria. METHODS: The study population was 18 patients with GSTs of the intraluminal muscularis propria layer. Eight were treated by MLIGS performed according to the following procedures: (1) gastroscopy was used to expose and confirm the location of the tumor; (2) a laparoscope light was placed in the cavity using the trocar at the navel, with the remaining two trocars penetrating both the abdominal and stomach walls; (3) the operation was performed in the gastric lumen using laparoscopic instruments with gastroscope monitoring, and the tumor was resected; (4) the tumor tissue was removed orally using a grasping forceps; (5) and the puncture holes and perforation in the stomach were sutured using titanium clips. The remaining 10 patients were treated by EFR, which involved (1) injection of normal saline into the submucosa and precutting of the mucosal and submucosal layer around the lesion, (2) a circumferential incision as deep as the muscularis propria around the lesion, (3) an incision into the serosal layer around the lesion, (4) completion of full-thickness incision to the tumor, (5) closure of the gastric wall defect with clips. RESULTS: The GSTs all were resected completely. The two groups did not differ significantly in terms of tumor size, hospital stay, or abdominal pain time. But in the MLIGS group, the operation time and blood loss were significantly decreased compared with the EFR group. No postoperative complications occurred in the MLIGS group, whereas one peritoneal abscess occurred in the EFR group. The pathology of all the resected specimens showed GST. No case of implantation or metastasis was found. CONCLUSIONS: Both MLIGS and EFR are feasible and effective treatments for GSTs from the muscularis propria. Moreover, both are minimally invasive.

New-style laparoscopic and endoscopic cooperative surgery for gastric stromal tumors.

AIM: To evaluate the feasibility and safety of a new style of laparoscopic and endoscopic cooperative surgery (LECS), an improved method of laparoscopic intragastric surgery (LIGS) for the treatment of gastric stromal tumors (GSTs). METHODS: Six patients were treated with the new-style LECS. Surgery was performed according to the following procedures: (1) Exposing and confirming the location of the tumor with gastroscopy; (2) A laparoscopy light was placed in the cavity using the trocar at the navel, and the other two trocars penetrated both the abdominal and stomach walls; (3) With gastroscopy monitoring, the operation was carried out in the gastric lumen using laparoscopic instruments and the tumor was resected; and (4) The tumor tissue was removed orally using a gastroscopy basket, and puncture holes and perforations were sutured using titanium clips. RESULTS: Tumor size ranged from 2.0 to 4.5 cm (average 3.50 ± 0.84 cm). The operative time ranged from 60 to 130 min (average 83.33 ± 26.58 min). Blood loss was less than 20 mL and hospital stay ranged from 6 to 8 d (average 6.67 ± 0.82 d). The patients were allowed out of bed 12 h later. A stomach tube was inserted for 72 h after surgery, and a liquid diet was then taken. All cases had single tumors which were completely resected using the new-style LECS. No postoperative complications occurred. Pathology of all resected specimens showed GST: no cases of implantation or metastasis were found. CONCLUSION: New-style LECS for GSTs is a quick, optimized, fast recovery, safe and effective therapy.

19-VNTR loci used in genotyping Chinese clinical Mycobacterium tuberculosis complex strains and in association with spoligotyping.

Recently, tandem repeat typing has emerged as a rapid and easy method for the molecular epidemiology of the Mycobacterium tuberculosis (M. tuberculosis) complex. In this study, a collection of 19 VNTRs incorporating 15 previously described loci and 4 newly evaluated markers were used to genotype 206 Chinese M. tuberculosis isolates and 9 BCG strains. The discriminatory power was evaluated and compared with that obtained by Spoligotyping. It turned out that 15-locus VNTR could be very useful in M. tuberculosis complex strains genotyping in China. The 4 newly evaluated loci were proved informative and could be useful for future epidemiology studies, especially in Beijing family strains. In addition, a unique pattern of the latter 4 loci were found in Chinese BCG strains.

[Pro-angiogenic effects of four Chinese medicines and three herbal prescription in chicken chorioallantoic membrane model].

OBJECTIVE: To observe the pro-angiogenic effect of four Chinese medicines and three herbal prescriptions, screen the effective components from them. METHODS: Chicken chorioallantoic membrane (CAM) model was employed to observe the pro-angiogenic activities of Angelicae Sinensis Radix, Salviae Miltiorrhizae Radix, Notoginseng Radix, Astragali Radix, Xuefuzhuyu decoction, Dangguibuxue decoction and Taohongsiwu decoction, all of them were claimed to promote angiogenesis. The effective components were screened from the extracts. RESULTS: Compared with negative control group, the blood vessel densities in Angelicae Sinensis Radix and Notoginseng Radix groups were not increased significantly (P > 0.05). However, blood vessel densities in Astragali Radix group, Salviae Miltiorrhizae Radix group, Xuefuzhuyu decoction group, Dangguibuxue decoction group and Taohongsiwu decoction group were notably enhanced (P < 0.05). Dangguibuxue decoction showed a more than 90% of increase in blood vessel densities as compared with the negative control group (P < 0.01), and components contained ferulic acid and astragaloside from Dangguibuxue decoction displayed significantly pro-angiogenic effect (P < 0.05). CONCLUSION: Dangguibuxue decoction and its extract, components contained ferulic acid and astragaloside, can improve angiogenesis in CAM model significantly.

A new multilocus sequence analysis scheme for Mycobacterium tuberculosis.

OBJECTIVE: Tuberculosis remains one of the most serious infectious diseases in the world. In this study, a scheme of Mycobacterium tuberculosis (M. tuberculosis) multilocus sequence analysis (MLSA) was established for the phylogenetic and epidemiology analysis. METHODS: To establish the scheme of M. tuberculosis MLSA, the genome of H37Rv, CCDC5079 and CCDC5180 were compared, and some variable genes were chosen to be the MLSA typing scheme. 44 M. tuberculosis clinical isolates were typed by MLSA, IS6110-RFLP, and soligotyping, to evaluate the MLSA methods. RESULTS: After comparison of the genome, seven high discrimination gene loci (recX, rpsL, rmlC, rpmG1, mprA, gcvH, ideR) were chosen to be the MLSA typing scheme finally. 11 variable SNP sites of those seven genes were found among the 44 M. tuberculosis isolate strains and 11 sequence types (STs) were identified. Based on the Hunter-Gaston Index (HGI), MLSA typing was not as good for discrimination at the strain level as IS6110-RFLP, but the HGI was much better than that of spoligotyping. In addition, the MEGA analysis result of MLSA data was similar to spoligotyping/PGG lineage, showing a strong phylogenetic signal in the modern strains of M. tuberculosis. The MLSA data analysis by eBURST revealed that 4 sequence types (ST) came into a main cluster, showing the major clonal complexes in those 44 strains. CONCLUSION: MLSA genotyping not only can be used for molecular typing, but also is an ideal method for the phylogenetic analysis for M. tuberculosis.