Background:Skeletal tuberculosis(TB)remains a persistent clinical and research chal-lenge due to its chronic course,osteolytic destruction,and the limitations of existing animal models,which often require high-level b...Background:Skeletal tuberculosis(TB)remains a persistent clinical and research chal-lenge due to its chronic course,osteolytic destruction,and the limitations of existing animal models,which often require high-level biosafety containment or fail to repli-cate human skeletal pathology.Methods:This study developed a biosafe,accessible,and versatile murine model of skeletal TB using Mycobacterium smegmatis,a fast-growing,nonpathogenic myco-bacterial species with high genomic homology to Mycobacterium tuberculosis.Three infection routes-subperiosteal calvarial injection,intratibial injection,and intra-cardiac inoculation-were systematically evaluated for their ability to induce lo-calized versus disseminated bone infection under standard biosafety level(BSL)-1 conditions.Results:Subperiosteal calvarial and intratibial injection of M.smegmatis induced local-ized bone lesions characterized by osteolysis,sequestrum formation,granulomatous inflammation,and increased osteoclast activity.Intratibial infection additionally trig-gered compartment-specific immune responses,including neutrophil and macrophage expansion,transient B-cell depletion,and activation of interferon-γ^(+)(IFN-γ^(+))T cells,reflecting active immune remodeling at the infection site.Systemic dissemination via intracardiac injection reproducibly generated progressive vertebral and tibial bone destruction with organized granuloma formation and immune cell infiltration but without prominent sequestrum formation.Compared to intratibial infection,intracar-diac delivery exhibited lower intragroup variability and more closely recapitulated the diffuse progression of extrapulmonary skeletal tuberculosis.Conclusions:This M.smegmatis-based murine model provides a straightforward,reliable,and immunopathologically relevant platform for exploring host-pathogen dynamics,immune-driven bone destruction,and early-stage therapeutic testing in skeletal TB,all within standard BSL-1 laboratories.This model fills a critical gap by enabling BSL-1 research into skeletal TB mechanisms and drug development.展开更多
Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RAL...Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RALs)library constructed in the laboratory for in vitro anti-Mycobacterium marinum activity and found that several compounds,including compounds 3,4,6,10,and 17–26,showed good activity.Notably,the trace natural product cochilimycin B(compound 3)possesses significant long-lasting inhibitory function to Mycobacterium marinum.It also shows synergistic effects with drugs like isoniazid,ethambutol,and bedaquiline(FICI≤0.5).In addition,cochilimycin B showed a significant inhibitory effect on the biofilm produced by Mycobacterium marinum,with an inhibition rate of 65.9%.To solve the bottleneck problem of natural product drug sources,we realized an efficient one-step semi-synthetic method to obtain compound 3 with a yield of 32.1%.In vivo,inflammatory changes in BALB/c mice infected with Mycobacterium marinum were characterized.After 12 h of infection,IL-1βwas 20%–30%lower in the spleen and tail of the3-treated group compared to the control group.In the thymus and tail of the treated group,TNF-αlevels were 30%–60%lower than in the control group.This is the first time that the significant anti-Mycobacterium marinum effect of cochilimycin B from 14-Membered Resorcylic Acid Lactones(14-RALs)was reported,offering a new chemical molecule for anti-Mycobacterium marinum drug research.展开更多
BACKGROUND Tuberculosis is among the most devastating infectious diseases worldwide.Spinal tuberculosis is not easy to detect at an early stage,which without effective treatment often leads to spinal deformity and spi...BACKGROUND Tuberculosis is among the most devastating infectious diseases worldwide.Spinal tuberculosis is not easy to detect at an early stage,which without effective treatment often leads to spinal deformity and spinal cord damage which in turn cause complications such as paraplegia and quadriplegia.In this study,we established a model using three concentrations of bacteria and carried out a comprehensive evaluation of the model by imaging,general observations,and histopathological and bacteriological studies.AIM To establish a rabbit model of spinal tuberculosis and examine the effect on the model’s efficacy using different concentrations of Mycobacterium tuberculosis(M.tuberculosis)inoculum.METHODS New Zealand rabbits were randomly divided into experimental,control and blank groups.The experimental and control animals were sensitized with complete Freund′s adjuvant,a hole was drilled beneath the upper endplate of the L6 vertebral body and filled with gelfoam sponge.The experimental group was divided into three subgroups(experimental 1,experimental 2,experimental 3)and infused with M.tuberculosis suspension at various concentrations.The control group was inoculated with saline and the blank group received no treatment.The 12-week post-operative survival rates were 100%,80%and 30%in the experimental groups inoculated with concentrations of 106,107 and 108 CFU/mL bacteria,respectively.RESULTS The survival rate of the control and blank groups was 100%.Vertebral body destruction at 8 weeks in the three experimental groups as determined by X-ray analysis was 33.3%,62.5%and 66.7%,and by computed tomography(CT)and 3-dimensional CT 44.4%,75%and 100%,respectively.At 12 weeks,the figures were 44.4%,75%and 100%by X-ray analysis and 44.4%,100%and 100%by CT and 3-dimensional CT,respectively.All surviving rabbits of the experimental groups had vertebral destruction.The positive bacterial culture rates were 22.2%,75%and 66.7%,respectively,in the experimental groups.After being sensitized with complete Freund's adjuvant,large differences were observed in the extent of spinal tuberculosis after inoculation of the rabbits with different concentrations of H37RV standard M.tuberculosis.CONCLUSION The experimental 1 had a low success rate at establishing an infection.The experimental 3 resulted in high mortality and complication rates.The experimental 2 was optimum for establishing a spinal tuberculosis model based on the high level of symptoms observed and the low rabbit mortality.展开更多
Mycobacterium tuberculosis(Mtb)employs multiple mechanisms,such as phagocytosis and autophagy,to evade innate immune clearance and establish infection.In the present study,we identified the ESX-1 secretion-associated ...Mycobacterium tuberculosis(Mtb)employs multiple mechanisms,such as phagocytosis and autophagy,to evade innate immune clearance and establish infection.In the present study,we identified the ESX-1 secretion-associated protein EspL,which promotes Mtb survival by inhibiting phagosome maturation and autophagy initiation.EspL knockout decreased Mtb intracellular survival,while EspL overexpression increased bacterial survival by interfering with phagocytosis and autophagy.EspL interacts with ULK1 and promotes its phosphorylation at Ser^(757),leading to the inhibition of autophagy initiation.Additionally,overexpression of EspL reduced antigen presentation and T-cell responses both in vitro and in vivo.Our findings revealed that EspL interferes with autophagy and antigen presenta-tion by suppressing ULK1 activation.These insights provide a novel understanding of Mtb pathogenicity.展开更多
Detection and treatment of drug resistance in extrapulmonary tuberculosis(EPTB)is a major challenge worldwide.Drug resistance in EPTB has not been studied extensively.However,patients with drug-resistant EPTB have bee...Detection and treatment of drug resistance in extrapulmonary tuberculosis(EPTB)is a major challenge worldwide.Drug resistance in EPTB has not been studied extensively.However,patients with drug-resistant EPTB have been reported to have poor outcomes[1].Rifampicin and isoniazid are the cornerstone drugs in the management of EPTB.Resistance in Mycobacterium(M.)tuberculosis to these drugs commonly arises due to mutations in the‘rpoB’gene and‘katG&inhA’genes,which confer resistance to rifampicin and isoniazid,respectively.Treatment outcomes are affected by the presence of these mutations.In addition,anatomical and physiological barriers impede the effective delivery of drugs to the affected extrapulmonary site[1].An analysis of the frequency of mutations in drug resistant M.tuberculosis strains causing EPTB in our region can help identify patterns of drug resistance.This,in turn,can provide inputs that may be used for modifying standard treatment regimens to make them more effective.The present study aims to identify the frequency and pattern of mutations in the‘rpoB’gene and‘katG&inhA’genes in M.tuberculosis strains isolated from EPTB samples.展开更多
Tuberculosis,an infectious disease,causes considerable morbidity and mortality.Within the host immune system,transition metals play vital roles in combating Mycobacterium tuberculosis(MTB),acting as catalytic cofactor...Tuberculosis,an infectious disease,causes considerable morbidity and mortality.Within the host immune system,transition metals play vital roles in combating Mycobacterium tuberculosis(MTB),acting as catalytic cofactors,mediating electron transport,and catalyzing antimicrobial radical formation.Both the host and MTB have developed mechanisms to maintain metal homeostasis.Flavonoids,important herbal materials with potent iron-chelating ability,have gained attention for their antitubercular and anti-inflammatory effects,making them a promising treatment option.This review explores how trace metals restrict MTB and the dynamic balance between pathogen and host,revealing innovative perspectives for therapeutic interventions.展开更多
Background:Whipple’s Disease(WD)is a chronic and recurrent multisystem disease caused by Tropheryma whipplei(TW).Typically,MTB infection compromises the immune system.However,clinical reports of MTB and TW co-infecti...Background:Whipple’s Disease(WD)is a chronic and recurrent multisystem disease caused by Tropheryma whipplei(TW).Typically,MTB infection compromises the immune system.However,clinical reports of MTB and TW co-infection are rare.Methods:This study retrospectively analyzed the admission symptoms and biochemical test results of 39 patients co-infected with MTB and TW between January 1,2023,and August 31,2024,at the Infectious Disease Hospital of Heilongjiang Province,China.This study further compared the admission indicators between individuals with co-infections involving more than two pathogens(multi-infected)and those infected with only MTB and TW(Co-Infected).Results:The hospitalized patients had a median age of 50(39–58)years.Most of the patients were male(69.23%,27/39).Most patients presented with cough(87.18%,34/39),sputum production(76.92%,30/39),shortness of breath(64.10%,25/39),and reduced appetite or even anorexia(53.85%,21/39).However,fever(41.03%,14/39)and fatigue(41.03%,16/39)were less common.Among the patients who underwent these four biochemical tests,the majority(86.36%,19/22)had an A/G ratio below the normal range at the time of admission,primarily due to an increase in serum globulin levels.Multi-Infected group had higher levels of alanine aminotransferase than the Co-Infected group(17 vs.10,p=0.035),and aspartate aminotransferase is also higher in the multi-infected group compared to the Co-Infected group(20 vs.14,p=0.034).Conclusion:This is the first study to report the coinfection of Tropheryma whipplei(TW)and Mycobacterium tuberculosis(MTB)in Heilongjiang Province,China.However,this study did not find significant differences from descriptions in existing literature.Therefore,this study has provided a descriptive analysis to serve as a reference for further understanding TW infections.展开更多
Background:The diagnosis of tuberculous pleurisy(TP)presents a significant challenge due to the low bacterial load in pleural effusion(PE)samples.Cell-free Mycobacterium tuberculosis DNA(cf-TB)in PE samples is conside...Background:The diagnosis of tuberculous pleurisy(TP)presents a significant challenge due to the low bacterial load in pleural effusion(PE)samples.Cell-free Mycobacterium tuberculosis DNA(cf-TB)in PE samples is considered an optimal biomarker for diagnosing TP.This study aimed to evaluate the applicability of cf-TB testing across diverse research sites with a relatively large sample size.Methods:Patients suspected of TP and presenting with clinical symptoms and radiological evidence of PE were consecutively enrolled by treating physicians from 11 research sites across 6 provinces in China between April 2020 and August 2022.Following centrifugation,sediments obtained from PE were used for Xpert MTB/RIF(Xpert)and mycobacterial culture,while the supernatants were subjected to cf-TB testing.This study employed a composite reference standard to definite TP,which was characterized by any positive result for Mycobacterium tuberculosis(MTB)through either PE culture,PE Xpert,or pleural biopsy.Results:A total of 1412 participants underwent screening,and 1344(95.2%)were subsequently enrolled in this study.Data from 1241(92.3%)participants were included,comprising 284 with definite TP,677 with clinically diagnosed TP,and 280 without TP.The sensitivity of cf-TB testing in definite TP was 73.6%(95%CI 68.2%-78.4%),significantly higher than both Xpert(40.8%,95%CI 35.3%-46.7%,P<0.001)and mycobacterial culture(54.2%,95%CI 48.4%-59.9%,P<0.001).When clinically diagnosed TP was incorporated into the composite reference standard for sensitivity analysis,cf-TB testing showed a sensitivity of 46.8%(450/961,95%CI 43.7%-50.0%),significantly higher than both Xpert(12.1%,116/961,95%CI 10.2%-14.3%,P<0.001)and mycobacterial culture(16.0%,154/961,95%CI 13.8%-18.5%,P<0.001).The specificities of cf-TB testing,Xpert,and mycobacterial culture were all 100.0%.Conclusions:The performance of cf-TB testing is significantly superior to that of Xpert and mycobacterial culture methods,indicating that it can be considered as the primary diagnostic approach for improving TP detection.Trial registration:The trial was registered on Chictr.org.cn(ChiCTR2000031680,https://www.chictr.org.cn/showproj.html?proj=49316).展开更多
With the continuous emergence and rapid spread of multidrug-resistant and extensively-drug-resistant Mycobacterium tuberculosis strains, it is imperative to develop novel therapies against this bacterium. The intrins...With the continuous emergence and rapid spread of multidrug-resistant and extensively-drug-resistant Mycobacterium tuberculosis strains, it is imperative to develop novel therapies against this bacterium. The intrinsic β-lactam resistance of M. tuberculosis is primarily due to the production of an Ambler class-A β-lactamase BlaC, which limits the application of β-lactam antibiotics in the treatment of tuberculosis. Therefore, the inhibitors of BlaC could be novel anti-tuberculosis drug synergistic agents to recover the sensibility of M. Tuberculosis to the β-lactam antibiotics. In the present study, BlaC of M. tuberculosis was expressed and purified to establish a screening model of the BlaC inhibitors. The screening conditions were determined, and the screening model was evaluated to fit for the high throughput screening. A total of 22 BlaC inhibitors were screened out from 26 400 compound samples with a positive rate of 0.083%. Taken together, our findings lay the foundation for the discovery of novel anti-tuberculosis drug synergistic agents in clinic.展开更多
Mycobacterium paragordonae(M.paragordonae),a slow-growing,acid-resistant mycobacterial species,was first isolated from the sputum of a lung infection patient in South Korea in 2014.Infections caused by M.paragordonae ...Mycobacterium paragordonae(M.paragordonae),a slow-growing,acid-resistant mycobacterial species,was first isolated from the sputum of a lung infection patient in South Korea in 2014.Infections caused by M.paragordonae are rare.CASE SUMMARY Herein,we report the case of a 53-year-old patient who presented with fever and low back pain.Lumbar nuclear magnetic resonance imaging revealed the destruction of the lumbar vertebra with peripheral abscess formation.After antiinfective and diagnostic anti-tuberculosis treatment,the patient had no further fever,but the back pain was not relieved.Postoperatively,the necrotic material was sent for pathological examination,and all tests related to tuberculosis were negative,but pus culture suggested nontuberculous mycobacteria.The necrotic tissue specimens were subjected to metagenomic next-generation sequencing,which indicated the presence of M.paragordonae.Finally,the infecting pathogen was identified,and the treatment plan was adjusted.The patient was in good condition during the follow-up period.CONCLUSION M.paragordonae,a rare nontuberculous mycobacterium,can also cause spinal infections.In the clinic,it is necessary to identify nontuberculous mycobacteria for spinal infections similar to Mycobacterium tuberculosis.展开更多
Objective To identify the novel species ‘Mycobacterium fukienense＇ sp. nov of Mycobacterium chelonoe/abscessus complex from tuberculosis patients in Fujian Province, China. Methods Five of 27 clinical Mycobucterium ...Objective To identify the novel species ‘Mycobacterium fukienense＇ sp. nov of Mycobacterium chelonoe/abscessus complex from tuberculosis patients in Fujian Province, China. Methods Five of 27 clinical Mycobucterium isolates （CIs） were previously identified as M. chelonoe/obscessus complex by sequencing the hsp65, rpoB, 165-235 rRNA internal transcribed spacer region （its）, recA and sodA house-keeping genes commonly used to describe the molecular characteristics of Mycobocterium. Clinical Mycobecterium isolates were classified according to the gene sequence using a clustering analysis program. Sequence similarity within clusters and diversity between clusters were analyzed. Results The 5 isolates were identified with distinct sequences exhibiting 99.8% homology in the hsp65 gene. However, a complete lack of homology was observed among the sequences of the rpoB, 165-235 rRNA internal tronscribed spacer region （its）, sodA, and recA genes as compared with the M. obscessus. Furthermore, no match for rpoB, sodA, and recA genes was identified among the published sequences. Conclusion The novel species, Mycobacterium fukienense, is identified from tuberculosis patients in Fujian Province, China, which does not belong to any existing subspecies of M. cheloneo/abscessus complex.展开更多
Objective In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were al...Objective In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study. Methods Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction （PCR） and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay. Results Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacteriurn elephantis （M. elephantis）. The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline. Conclusion To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.展开更多
Resuscitation promoting factor E （RpfE） is one of the five Rpf-like proteins in Mycobacterium tuberculos＆ （M. tuberculosis）. These Rpf-like proteins are secretory, which make them candidates for recognition by th...Resuscitation promoting factor E （RpfE） is one of the five Rpf-like proteins in Mycobacterium tuberculos＆ （M. tuberculosis）. These Rpf-like proteins are secretory, which make them candidates for recognition by the host immune system. In this study, the RpfE gene was amplified from M. tuberculosis, cloned into the expression vectors pDE22 and pPRO EXHT, and were expressed in Mycobacterium vaccae （M. vaccae） and Escherichia coli DHSa, respec- tively. Both recombinant RpfE proteins were purified by Ni-Sepharose affinity chromatography, and were given to C57BL/6 mice. The RpfE proteins elicited T cell proliferation, and stimulated the production of gamma interferon （IFN-y）, interleukin-10 （IL-10） and IL-12. Our results indicated that the RpfE protein expressed in M. vaccae could more efficiently stimulate cellular immune response, making it a promising candidate as a subunit vaccine.展开更多
The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c p...The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c protein in Mycobacterium infection by purifying the Rv1043c protein in Escherichia coli and constructing a Mycobacterium smegmatis(Msg)strain overexpressing Rv1043c(Msg_Rv1043c).We found that Rv1043c had serine protease activity and localized to the surface of Mtb.We determined that the optimal pH and temperature for the Rv1043c serine protease were 9.0 and 45°C,respectively.Moreover,the serine protease activity of Rv1043c was enhanced by divalent metal ions of Ca^(2+)and Mg^(2+).Site-directed mutagenesis studies demonstrated that the serine 279 residue in Rv1043c plays a catalytic role.Additionally,mouse model studies confirmed that Rv1043c significantly enhanced the survival of Msg in vivo,induced pulmonary injury and lung cell apoptosis,and promoted the release of pro-inflammatory cytokines interleukin-1βand interleukin-6 in mice.This study presents novel insights into the relationship between mycobacterial serine protease and the pathogenesis of the disease.展开更多
Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare w...Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare were used to immunize BALB/c mice.The antigens were evaluated using cellular and humoral immunoassays.The common genes between M.intracellular and M.tuberculosis were identified using genome-wide comparative analysis,and cross-reactive proteins were screened using immunoproteome microarrays.Results Immunization with M.intracellulare proteins induced significantly higher levels of the cytokines interferon-γ(IFN-γ),interleukin-2(IL-2),interleukin-12(IL-12),interleukin-6(IL-6)and immunoglobulins IgG,IgG1,IgM,and IgG2a in mouse serum.Bone marrow-derived macrophages isolated from mice immunized with M.intracellulare antigens displayed significantly lower bacillary loads than those isolated from mice immunized with adjuvants.Whole-genome sequence analysis revealed 396 common genes between M.intracellulare and M.tuberculosis.Microchip hybridization with M.tuberculosis proteins revealed the presence of 478 proteins in the serum of mice immunized with M.intracellulare protein extracts.Sixty common antigens were found using both microchip and genomic comparative analyses.Conclusion This is the advanced study to investigate the immunogenicity of M.intracellulare proteins and the cross-reactive proteins between M.intracellulare and M.tuberculosis.The results revealed the presence of a number of cross-reactive proteins between M.intracellulare and M.tuberculosis.Therefore,this study provides a new way of identifying immunogenic proteins for use in tuberculosis vaccines against both M.intracellulare and M.tuberculosis in future.展开更多
BACKGROUND The incidence of infection with Mycobacterium abscessus(M.abscessus)has increased in recent years.This increase is partly associated with invasive cosmetic procedures.CASE SUMMARY The purpose of this case s...BACKGROUND The incidence of infection with Mycobacterium abscessus(M.abscessus)has increased in recent years.This increase is partly associated with invasive cosmetic procedures.CASE SUMMARY The purpose of this case summary is to increase clinicians'awareness of M.abscessus infection and reduce mycobacterial infection caused by cosmetic procedures.We report the case of a 45-year-old woman who received acetyl hexapeptide-8(argireline)injections in the forehead and temples,and erythema,nodules,and abscesses appeared at the injection sites after one week.The pus specimens were examined by microbiological culture and confirmed to be positive for M.abscessus.Clarithromycin 500 mg twice daily and moxifloxacin 400 mg once daily were administered for 5 mo and the lesions gradually subsided.CONCLUSION We report here for the first time a case of infection with M.abscessus after argireline injection.This condition is easily misdiagnosed as a common bacterial infection.Microbiological examinations are helpful for diagnosis and standardized cosmetic procedures can prevent infection with M.abscessus.展开更多
基金Southwest Hospital Boqing Innovation Fund,Grant/Award Number:2024BQCXJJ-9Fundings for Young Investigators of PLA,Grant/Award Number:2022-JCJQ-QT-004+3 种基金NSFC Key Projects of the Regional Innovation and Development Joint Fund,Grant/Award Number:U23A20413China Postdoctoral Science Foundation,Grant/Award Number:2023M744280National Natural Science Foundation of China,Grant/Award Number:82103778,82172449 and 82172489Southwest Hospital Postdoctoral Starting Fund,Grant/Award Number:5175ZA36BP。
文摘Background:Skeletal tuberculosis(TB)remains a persistent clinical and research chal-lenge due to its chronic course,osteolytic destruction,and the limitations of existing animal models,which often require high-level biosafety containment or fail to repli-cate human skeletal pathology.Methods:This study developed a biosafe,accessible,and versatile murine model of skeletal TB using Mycobacterium smegmatis,a fast-growing,nonpathogenic myco-bacterial species with high genomic homology to Mycobacterium tuberculosis.Three infection routes-subperiosteal calvarial injection,intratibial injection,and intra-cardiac inoculation-were systematically evaluated for their ability to induce lo-calized versus disseminated bone infection under standard biosafety level(BSL)-1 conditions.Results:Subperiosteal calvarial and intratibial injection of M.smegmatis induced local-ized bone lesions characterized by osteolysis,sequestrum formation,granulomatous inflammation,and increased osteoclast activity.Intratibial infection additionally trig-gered compartment-specific immune responses,including neutrophil and macrophage expansion,transient B-cell depletion,and activation of interferon-γ^(+)(IFN-γ^(+))T cells,reflecting active immune remodeling at the infection site.Systemic dissemination via intracardiac injection reproducibly generated progressive vertebral and tibial bone destruction with organized granuloma formation and immune cell infiltration but without prominent sequestrum formation.Compared to intratibial infection,intracar-diac delivery exhibited lower intragroup variability and more closely recapitulated the diffuse progression of extrapulmonary skeletal tuberculosis.Conclusions:This M.smegmatis-based murine model provides a straightforward,reliable,and immunopathologically relevant platform for exploring host-pathogen dynamics,immune-driven bone destruction,and early-stage therapeutic testing in skeletal TB,all within standard BSL-1 laboratories.This model fills a critical gap by enabling BSL-1 research into skeletal TB mechanisms and drug development.
基金supported by the Program of National Natural Science Foundation of China(Nos.42376116,41322037,U1706210)the Special Funds of Shandong Province for Qingdao National Laboratory of Marine Science and Technology(No.2022QNLM030003-3)+1 种基金the Shandong Province Special Fund‘Frontier Technology and Free Exploration’from Laoshan Laboratory(No.8-01)the State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources,Guangxi Normal University(No.CMEMR2023-B16)。
文摘Mycobacterium marinum can cause disease in both human beings and fishes.Infected fish exhibits symptoms commonly referred to as fish tuberculosis.In this research,we screened a 14-Membered Resorcylic Acid Lactones(RALs)library constructed in the laboratory for in vitro anti-Mycobacterium marinum activity and found that several compounds,including compounds 3,4,6,10,and 17–26,showed good activity.Notably,the trace natural product cochilimycin B(compound 3)possesses significant long-lasting inhibitory function to Mycobacterium marinum.It also shows synergistic effects with drugs like isoniazid,ethambutol,and bedaquiline(FICI≤0.5).In addition,cochilimycin B showed a significant inhibitory effect on the biofilm produced by Mycobacterium marinum,with an inhibition rate of 65.9%.To solve the bottleneck problem of natural product drug sources,we realized an efficient one-step semi-synthetic method to obtain compound 3 with a yield of 32.1%.In vivo,inflammatory changes in BALB/c mice infected with Mycobacterium marinum were characterized.After 12 h of infection,IL-1βwas 20%–30%lower in the spleen and tail of the3-treated group compared to the control group.In the thymus and tail of the treated group,TNF-αlevels were 30%–60%lower than in the control group.This is the first time that the significant anti-Mycobacterium marinum effect of cochilimycin B from 14-Membered Resorcylic Acid Lactones(14-RALs)was reported,offering a new chemical molecule for anti-Mycobacterium marinum drug research.
基金Supported by Lanzhou City Science and Technology Development Guiding Plan Project,No.2023-ZD-170Lanzhou Science and Technology Plan Project,No.2023-2-11High-Level Talent Training Project At the 940th Hospital of the Joint Logistics Force,No.2024-G3-5.
文摘BACKGROUND Tuberculosis is among the most devastating infectious diseases worldwide.Spinal tuberculosis is not easy to detect at an early stage,which without effective treatment often leads to spinal deformity and spinal cord damage which in turn cause complications such as paraplegia and quadriplegia.In this study,we established a model using three concentrations of bacteria and carried out a comprehensive evaluation of the model by imaging,general observations,and histopathological and bacteriological studies.AIM To establish a rabbit model of spinal tuberculosis and examine the effect on the model’s efficacy using different concentrations of Mycobacterium tuberculosis(M.tuberculosis)inoculum.METHODS New Zealand rabbits were randomly divided into experimental,control and blank groups.The experimental and control animals were sensitized with complete Freund′s adjuvant,a hole was drilled beneath the upper endplate of the L6 vertebral body and filled with gelfoam sponge.The experimental group was divided into three subgroups(experimental 1,experimental 2,experimental 3)and infused with M.tuberculosis suspension at various concentrations.The control group was inoculated with saline and the blank group received no treatment.The 12-week post-operative survival rates were 100%,80%and 30%in the experimental groups inoculated with concentrations of 106,107 and 108 CFU/mL bacteria,respectively.RESULTS The survival rate of the control and blank groups was 100%.Vertebral body destruction at 8 weeks in the three experimental groups as determined by X-ray analysis was 33.3%,62.5%and 66.7%,and by computed tomography(CT)and 3-dimensional CT 44.4%,75%and 100%,respectively.At 12 weeks,the figures were 44.4%,75%and 100%by X-ray analysis and 44.4%,100%and 100%by CT and 3-dimensional CT,respectively.All surviving rabbits of the experimental groups had vertebral destruction.The positive bacterial culture rates were 22.2%,75%and 66.7%,respectively,in the experimental groups.After being sensitized with complete Freund's adjuvant,large differences were observed in the extent of spinal tuberculosis after inoculation of the rabbits with different concentrations of H37RV standard M.tuberculosis.CONCLUSION The experimental 1 had a low success rate at establishing an infection.The experimental 3 resulted in high mortality and complication rates.The experimental 2 was optimum for establishing a spinal tuberculosis model based on the high level of symptoms observed and the low rabbit mortality.
基金supported by the National Natural Science Foundation of China under grant number U21A20259the National Key Research and Development Program of China under grant number 2021YFD1800401.
文摘Mycobacterium tuberculosis(Mtb)employs multiple mechanisms,such as phagocytosis and autophagy,to evade innate immune clearance and establish infection.In the present study,we identified the ESX-1 secretion-associated protein EspL,which promotes Mtb survival by inhibiting phagosome maturation and autophagy initiation.EspL knockout decreased Mtb intracellular survival,while EspL overexpression increased bacterial survival by interfering with phagocytosis and autophagy.EspL interacts with ULK1 and promotes its phosphorylation at Ser^(757),leading to the inhibition of autophagy initiation.Additionally,overexpression of EspL reduced antigen presentation and T-cell responses both in vitro and in vivo.Our findings revealed that EspL interferes with autophagy and antigen presenta-tion by suppressing ULK1 activation.These insights provide a novel understanding of Mtb pathogenicity.
文摘Detection and treatment of drug resistance in extrapulmonary tuberculosis(EPTB)is a major challenge worldwide.Drug resistance in EPTB has not been studied extensively.However,patients with drug-resistant EPTB have been reported to have poor outcomes[1].Rifampicin and isoniazid are the cornerstone drugs in the management of EPTB.Resistance in Mycobacterium(M.)tuberculosis to these drugs commonly arises due to mutations in the‘rpoB’gene and‘katG&inhA’genes,which confer resistance to rifampicin and isoniazid,respectively.Treatment outcomes are affected by the presence of these mutations.In addition,anatomical and physiological barriers impede the effective delivery of drugs to the affected extrapulmonary site[1].An analysis of the frequency of mutations in drug resistant M.tuberculosis strains causing EPTB in our region can help identify patterns of drug resistance.This,in turn,can provide inputs that may be used for modifying standard treatment regimens to make them more effective.The present study aims to identify the frequency and pattern of mutations in the‘rpoB’gene and‘katG&inhA’genes in M.tuberculosis strains isolated from EPTB samples.
文摘Tuberculosis,an infectious disease,causes considerable morbidity and mortality.Within the host immune system,transition metals play vital roles in combating Mycobacterium tuberculosis(MTB),acting as catalytic cofactors,mediating electron transport,and catalyzing antimicrobial radical formation.Both the host and MTB have developed mechanisms to maintain metal homeostasis.Flavonoids,important herbal materials with potent iron-chelating ability,have gained attention for their antitubercular and anti-inflammatory effects,making them a promising treatment option.This review explores how trace metals restrict MTB and the dynamic balance between pathogen and host,revealing innovative perspectives for therapeutic interventions.
文摘Background:Whipple’s Disease(WD)is a chronic and recurrent multisystem disease caused by Tropheryma whipplei(TW).Typically,MTB infection compromises the immune system.However,clinical reports of MTB and TW co-infection are rare.Methods:This study retrospectively analyzed the admission symptoms and biochemical test results of 39 patients co-infected with MTB and TW between January 1,2023,and August 31,2024,at the Infectious Disease Hospital of Heilongjiang Province,China.This study further compared the admission indicators between individuals with co-infections involving more than two pathogens(multi-infected)and those infected with only MTB and TW(Co-Infected).Results:The hospitalized patients had a median age of 50(39–58)years.Most of the patients were male(69.23%,27/39).Most patients presented with cough(87.18%,34/39),sputum production(76.92%,30/39),shortness of breath(64.10%,25/39),and reduced appetite or even anorexia(53.85%,21/39).However,fever(41.03%,14/39)and fatigue(41.03%,16/39)were less common.Among the patients who underwent these four biochemical tests,the majority(86.36%,19/22)had an A/G ratio below the normal range at the time of admission,primarily due to an increase in serum globulin levels.Multi-Infected group had higher levels of alanine aminotransferase than the Co-Infected group(17 vs.10,p=0.035),and aspartate aminotransferase is also higher in the multi-infected group compared to the Co-Infected group(20 vs.14,p=0.034).Conclusion:This is the first study to report the coinfection of Tropheryma whipplei(TW)and Mycobacterium tuberculosis(MTB)in Heilongjiang Province,China.However,this study did not find significant differences from descriptions in existing literature.Therefore,this study has provided a descriptive analysis to serve as a reference for further understanding TW infections.
基金supported by the Beijing Municipal Science and Technology Project(Z191100006619079)the General Program of the National Natural Science Foundation of China(82072381).
文摘Background:The diagnosis of tuberculous pleurisy(TP)presents a significant challenge due to the low bacterial load in pleural effusion(PE)samples.Cell-free Mycobacterium tuberculosis DNA(cf-TB)in PE samples is considered an optimal biomarker for diagnosing TP.This study aimed to evaluate the applicability of cf-TB testing across diverse research sites with a relatively large sample size.Methods:Patients suspected of TP and presenting with clinical symptoms and radiological evidence of PE were consecutively enrolled by treating physicians from 11 research sites across 6 provinces in China between April 2020 and August 2022.Following centrifugation,sediments obtained from PE were used for Xpert MTB/RIF(Xpert)and mycobacterial culture,while the supernatants were subjected to cf-TB testing.This study employed a composite reference standard to definite TP,which was characterized by any positive result for Mycobacterium tuberculosis(MTB)through either PE culture,PE Xpert,or pleural biopsy.Results:A total of 1412 participants underwent screening,and 1344(95.2%)were subsequently enrolled in this study.Data from 1241(92.3%)participants were included,comprising 284 with definite TP,677 with clinically diagnosed TP,and 280 without TP.The sensitivity of cf-TB testing in definite TP was 73.6%(95%CI 68.2%-78.4%),significantly higher than both Xpert(40.8%,95%CI 35.3%-46.7%,P<0.001)and mycobacterial culture(54.2%,95%CI 48.4%-59.9%,P<0.001).When clinically diagnosed TP was incorporated into the composite reference standard for sensitivity analysis,cf-TB testing showed a sensitivity of 46.8%(450/961,95%CI 43.7%-50.0%),significantly higher than both Xpert(12.1%,116/961,95%CI 10.2%-14.3%,P<0.001)and mycobacterial culture(16.0%,154/961,95%CI 13.8%-18.5%,P<0.001).The specificities of cf-TB testing,Xpert,and mycobacterial culture were all 100.0%.Conclusions:The performance of cf-TB testing is significantly superior to that of Xpert and mycobacterial culture methods,indicating that it can be considered as the primary diagnostic approach for improving TP detection.Trial registration:The trial was registered on Chictr.org.cn(ChiCTR2000031680,https://www.chictr.org.cn/showproj.html?proj=49316).
基金Fundamental Research Funds for Central Public Welfare Research Institutes(Grant No.2015PT350001)National Major Scientific and Technological Special Project for “Significant New Drugs Development”(Grant No.2015ZX09102007-009)
文摘With the continuous emergence and rapid spread of multidrug-resistant and extensively-drug-resistant Mycobacterium tuberculosis strains, it is imperative to develop novel therapies against this bacterium. The intrinsic β-lactam resistance of M. tuberculosis is primarily due to the production of an Ambler class-A β-lactamase BlaC, which limits the application of β-lactam antibiotics in the treatment of tuberculosis. Therefore, the inhibitors of BlaC could be novel anti-tuberculosis drug synergistic agents to recover the sensibility of M. Tuberculosis to the β-lactam antibiotics. In the present study, BlaC of M. tuberculosis was expressed and purified to establish a screening model of the BlaC inhibitors. The screening conditions were determined, and the screening model was evaluated to fit for the high throughput screening. A total of 22 BlaC inhibitors were screened out from 26 400 compound samples with a positive rate of 0.083%. Taken together, our findings lay the foundation for the discovery of novel anti-tuberculosis drug synergistic agents in clinic.
文摘Mycobacterium paragordonae(M.paragordonae),a slow-growing,acid-resistant mycobacterial species,was first isolated from the sputum of a lung infection patient in South Korea in 2014.Infections caused by M.paragordonae are rare.CASE SUMMARY Herein,we report the case of a 53-year-old patient who presented with fever and low back pain.Lumbar nuclear magnetic resonance imaging revealed the destruction of the lumbar vertebra with peripheral abscess formation.After antiinfective and diagnostic anti-tuberculosis treatment,the patient had no further fever,but the back pain was not relieved.Postoperatively,the necrotic material was sent for pathological examination,and all tests related to tuberculosis were negative,but pus culture suggested nontuberculous mycobacteria.The necrotic tissue specimens were subjected to metagenomic next-generation sequencing,which indicated the presence of M.paragordonae.Finally,the infecting pathogen was identified,and the treatment plan was adjusted.The patient was in good condition during the follow-up period.CONCLUSION M.paragordonae,a rare nontuberculous mycobacterium,can also cause spinal infections.In the clinic,it is necessary to identify nontuberculous mycobacteria for spinal infections similar to Mycobacterium tuberculosis.
基金supported by the National Key Programme of Mega Infectious Diseases (2008ZX100/03-010-02)the National Natural Science Funding of China (30800029)
文摘Objective To identify the novel species ‘Mycobacterium fukienense＇ sp. nov of Mycobacterium chelonoe/abscessus complex from tuberculosis patients in Fujian Province, China. Methods Five of 27 clinical Mycobucterium isolates （CIs） were previously identified as M. chelonoe/obscessus complex by sequencing the hsp65, rpoB, 165-235 rRNA internal transcribed spacer region （its）, recA and sodA house-keeping genes commonly used to describe the molecular characteristics of Mycobocterium. Clinical Mycobecterium isolates were classified according to the gene sequence using a clustering analysis program. Sequence similarity within clusters and diversity between clusters were analyzed. Results The 5 isolates were identified with distinct sequences exhibiting 99.8% homology in the hsp65 gene. However, a complete lack of homology was observed among the sequences of the rpoB, 165-235 rRNA internal tronscribed spacer region （its）, sodA, and recA genes as compared with the M. obscessus. Furthermore, no match for rpoB, sodA, and recA genes was identified among the published sequences. Conclusion The novel species, Mycobacterium fukienense, is identified from tuberculosis patients in Fujian Province, China, which does not belong to any existing subspecies of M. cheloneo/abscessus complex.
基金supported by the project 81401647 of Natural Science Foundation of ChinaProject 2014SKLID104 of State Key Laboratory for Infectious Diseases Prevention and Controlprojects 16411967900 of Science and Technology Commission of Shanghai Municipality
文摘Objective In this study, milk from a cow with mastitis was analyzed to determine the presence of mycobacterial infection. Milk quality and security problems pertaining to the safe consumption of dairy products were also discussed in this study. Methods Milk was preprocessed with 4% NaOH. Then, mycobacteria were isolated from the milk sample on L-J medium. The isolate was identified using multiple loci Polymerase Chain Reaction （PCR） and multi-locus sequence analysis with 16S rRNA, sodA, hsp65, and ITS genes. The drug sensitivity of the isolate to 27 antibiotics was tested through alamar blue assay. Results Smooth, moist, pale yellow colonies appeared on the L-J medium within a week after inoculation. Based on the results of multiple loci PCR analysis, the isolate was preliminarily identified as non-tuberculous mycobacteria. The 16S rRNA, SodA, hsp65, and ITS gene sequences of the isolate exhibited 99%, 99%, 99%, and 100% similarities, respectively, with those of the published reference strains of Mycobacteriurn elephantis （M. elephantis）. The drug sensitivity results showed that the strain is resistant to isoniazid, p-aminosalicylic acid, and trimesulf but is sensitive to ofloxacin, rifampicin, amikacin, capreomycin, moxifloxacin, kanamycin, levofloxacin, cycloserine, ethambutol, streptomycin, tobramycin, rifabutin, ciprofloxacin, linezolid, cefoxitin, clarithromycin, and minocycline. Conclusion To the best of our knowledge, this study is initially to report the isolation of M. elephantis from the milk of a cow with mastitis in China.
基金supported by National Natural Science Foundation of China (No.30470097,No.30500432)
文摘Resuscitation promoting factor E （RpfE） is one of the five Rpf-like proteins in Mycobacterium tuberculos＆ （M. tuberculosis）. These Rpf-like proteins are secretory, which make them candidates for recognition by the host immune system. In this study, the RpfE gene was amplified from M. tuberculosis, cloned into the expression vectors pDE22 and pPRO EXHT, and were expressed in Mycobacterium vaccae （M. vaccae） and Escherichia coli DHSa, respec- tively. Both recombinant RpfE proteins were purified by Ni-Sepharose affinity chromatography, and were given to C57BL/6 mice. The RpfE proteins elicited T cell proliferation, and stimulated the production of gamma interferon （IFN-y）, interleukin-10 （IL-10） and IL-12. Our results indicated that the RpfE protein expressed in M. vaccae could more efficiently stimulate cellular immune response, making it a promising candidate as a subunit vaccine.
基金This research was supported by the National Key Research and Development Program of China(2021YFD1800403)the National Natural Science Foundation of China(32273005 and 32002256).
文摘The serine proteases of Mycobacteria tuberculosis(Mtb)are important contributors to the process of bacterial invasion and its pathogenesis.In the present study,we systematically characterized the role of the Rv1043c protein in Mycobacterium infection by purifying the Rv1043c protein in Escherichia coli and constructing a Mycobacterium smegmatis(Msg)strain overexpressing Rv1043c(Msg_Rv1043c).We found that Rv1043c had serine protease activity and localized to the surface of Mtb.We determined that the optimal pH and temperature for the Rv1043c serine protease were 9.0 and 45°C,respectively.Moreover,the serine protease activity of Rv1043c was enhanced by divalent metal ions of Ca^(2+)and Mg^(2+).Site-directed mutagenesis studies demonstrated that the serine 279 residue in Rv1043c plays a catalytic role.Additionally,mouse model studies confirmed that Rv1043c significantly enhanced the survival of Msg in vivo,induced pulmonary injury and lung cell apoptosis,and promoted the release of pro-inflammatory cytokines interleukin-1βand interleukin-6 in mice.This study presents novel insights into the relationship between mycobacterial serine protease and the pathogenesis of the disease.
基金supported by National Science and Technology Major Project of China[2018ZX10731301-002]。
文摘Objectives To evaluate the immunogenicity of Mycobacterium intracellulare proteins and determine the cross-reactive proteins between M.intracellulare and M.tuberculosis.Methods Protein extracts from M.intracellulare were used to immunize BALB/c mice.The antigens were evaluated using cellular and humoral immunoassays.The common genes between M.intracellular and M.tuberculosis were identified using genome-wide comparative analysis,and cross-reactive proteins were screened using immunoproteome microarrays.Results Immunization with M.intracellulare proteins induced significantly higher levels of the cytokines interferon-γ(IFN-γ),interleukin-2(IL-2),interleukin-12(IL-12),interleukin-6(IL-6)and immunoglobulins IgG,IgG1,IgM,and IgG2a in mouse serum.Bone marrow-derived macrophages isolated from mice immunized with M.intracellulare antigens displayed significantly lower bacillary loads than those isolated from mice immunized with adjuvants.Whole-genome sequence analysis revealed 396 common genes between M.intracellulare and M.tuberculosis.Microchip hybridization with M.tuberculosis proteins revealed the presence of 478 proteins in the serum of mice immunized with M.intracellulare protein extracts.Sixty common antigens were found using both microchip and genomic comparative analyses.Conclusion This is the advanced study to investigate the immunogenicity of M.intracellulare proteins and the cross-reactive proteins between M.intracellulare and M.tuberculosis.The results revealed the presence of a number of cross-reactive proteins between M.intracellulare and M.tuberculosis.Therefore,this study provides a new way of identifying immunogenic proteins for use in tuberculosis vaccines against both M.intracellulare and M.tuberculosis in future.
基金The Scientific Research Project of Peking University Shenzhen Hospital,No.JCYJ2018011the San-ming Project of Medicine in Shenzhen,No.SZSM201812059.
文摘BACKGROUND The incidence of infection with Mycobacterium abscessus(M.abscessus)has increased in recent years.This increase is partly associated with invasive cosmetic procedures.CASE SUMMARY The purpose of this case summary is to increase clinicians'awareness of M.abscessus infection and reduce mycobacterial infection caused by cosmetic procedures.We report the case of a 45-year-old woman who received acetyl hexapeptide-8(argireline)injections in the forehead and temples,and erythema,nodules,and abscesses appeared at the injection sites after one week.The pus specimens were examined by microbiological culture and confirmed to be positive for M.abscessus.Clarithromycin 500 mg twice daily and moxifloxacin 400 mg once daily were administered for 5 mo and the lesions gradually subsided.CONCLUSION We report here for the first time a case of infection with M.abscessus after argireline injection.This condition is easily misdiagnosed as a common bacterial infection.Microbiological examinations are helpful for diagnosis and standardized cosmetic procedures can prevent infection with M.abscessus.
