[The target value of anticoagulation intensity for Chinese patients after mechanical heart valve replacement]

Objective: To explore the optimal intensity of anticoagulation therapy for Chinese patients after mechanical heart valve replacement. Methods: This is a prospective, multicenter, cohort study. The anticoagulation data from in-hospital patients of 35 medical centers and patients in outpatient clinic of 11 medical centers from Anticoagulation Therapy Database of Chinese Patients after Heart Valve Replacement between January 2011 and December 2015 were analyzed. The anticoagulation-relevant complications among different coagulation intensities were compared, and the optimal value of anticoagulation intensity for Chinese patients after mechanical heart valve replacement were analyzed. Results: A total of 24 433 patients were in the final analysis, including 13 634 females and 10 799 males, with a median age of 49.0 (3-80) years. International normalized ratio (INR) values of in-hospital patients were recorded 94 286 times, with the mean value of 1.8±0.7, and 87.6% (82 595/94 286) of them were within the range of 1.5 to 2.5. During a median follow-up time of 19.2 (1.0-58.8) months, a total of 17 331 outpatient clinic patients were followed up, with the follow-up rate of 89.1% (17 331/19 452) and a total of 27 803 patient-years (Pty), including 4 038 aortic valve replacement (AVR), 8 215 mitral valve replacement (MVR), 4 437 AVR plus MVR (double valve replacement, DVR) replacement and 641 tricuspidvalve replacement (TVR). A total of 101 860 INR measurements were recorded, with the mean value of 1.8±0.5, and 64.8% (66 005/101 860) of them were within the range of 1.5-2.5. The rates of anticoagulation-related complications of the patients with INR of 1.5-2.5 (0.65/100 Pty) were lower than those of other INR value patients (INR<1.5: 1.31/100 Pty, RR=2.01, 95%CI: 1.59-2.51, P<0.001; INR>2.5: 2.34/100 Pty, RR=3.60, 95%CI: 2.84-4.52, P<0.001). The rates of anticoagulation-related complications of AVR and MVR patients without risk factors and with INR of 1.5-2.0 were lower than those of other INR value patients (AVR: 0.15/100 Pty vs 0.38/100 Pty, RR=2.57, 95%CI: 1.02-7.28, P=0.029; MVR: 0.23/100 Pty vs 0.56/100 Pty, RR=2.42, 95%CI: 1.39-4.38, P<0.001), and the rate of anticoagulation-related complications of DVR patients with INR of 2.0-2.5 was lower than those of other INR value patients (0.32/100 Pty vs 0.62/100 Pty, RR=1.94, 95%CI: 1.03-3.79, P=0.029). Conclusions: A target INR range of 1.5-2.5 is recommended for Chinese patients after mechanical heart valve replacement. The optimal INR value for isolated AVR or MVR patients without risk factors was 1.5-2.0, while the optimal INR value for isolated AVR or MVR patients with risk factors and all the TVR or DVR patients was 2.0-2.5.

The Scap-SREBP1-S1P/S2P lipogenesis signal orchestrates the homeostasis and spatiotemporal activation of NF-κB

The nuclear factor κB (NF-κB) pathway plays essential roles in innate and adaptive immunity, but little is known how NF-κB signaling is compartmentalized and spatiotemporally activated in the cytoplasm. Here, we show that the lipogenesis signal cascade Scap-SREBP1-S1P/S2P orchestrates the homeostasis and spatiotemporal activation of NF-κB. SREBP cleavage-activating protein (Scap) and sterol regulatory element-binding protein 1 (SREBP1) form a super complex with inhibitors of NF-κB α (IκBα) to associate NF-κB close to the endoplasmic reticulum (ER). Upon lipopolysaccharide (LPS) stimulation, Scap transports the complex to the Golgi apparatus, where SREBP1 is cleaved by site-1 protease (S1P)/S2P, liberating IκBα for IκB kinase (Ikk)-mediated phosphorylation and subsequent activation of NF-κB. Loss of Scap or inhibition of S1P or S2P diminishes, while SREBP1 deficiency augments, LPS-induced NF-κB activation and subsequent inflammatory responses. Our results reveal the Scap-SREBP1 complex as an additional cytoplasmic checkpoint for NF-κB homeostasis and unveil the Golgi apparatus as the optimal cellular platform for NF-κB activation, providing insights into the crosstalk between lipogenesis signaling and immunity.

Bedaquiline resistance pattern in clofazimine-resistant clinical isolates of tuberculosis patients

BACKGROUND

Bedaquiline (BDQ) is a potent drug for treating drug-resistant tuberculosis (TB). Here, we analyzed the resistance profiles of BDQ in CFZ-resistant clinical isolates and investigated the clinical risk factors of BDQ and CFZ cross/co-resistance.

METHODS

The AlarmarBlue microplate assay was performed to determine the minimum inhibitory concentration (MIC) of the CFZ-resistant Mycobacterium tuberculosis (MTB) clinical isolates to CFZ and BDQ. The clinical characteristics of the respective patients were analyzed to explore the possible risk factors of BDQ resistance. The drug resistance-associated genes including Rv0678, Rv1979c, atpE, pepQ and Rv1453 were sequenced and analyzed.

RESULTS

A total of 72 clinical CFZ-resistant MTB isolates were collected; among these, half were identified as BDQ-resistant. The MIC value of BDQ closely correlated with CFZ (Spearman's q=0.766, P< 0.005). Among the isolates with a MIC of CFZ ≥4 mg/L, 92.31% (12/13) were resistant to BDQ. Pre-XDR and exposure to BDQ or CFZ are the major risk factors for concurrent BDQ resistance. Among the 36 cross/co-resistant isolates, 50% (18/36) had mutations in Rv0678, 8.3%(3/36)had mutations in Rv0678+Rv1453, 5.6%(2/36)had mutations in Rv0678+Rv1979c,2.8% (1/36) had mutations in Rv0678+Rv1979c+Rv1453, 2.8% (1/36) had mutations in atpE+Rv0678+Rv1453, 2.8% (1/36) had mutations in Rv1979c and 27.7% (10/36) had no variations in the target genes.

CONCLUSIONS

Nearly half of the CFZ-resistant isolates were still sensitive to BDQ, whereas this rate dramatically decreased among patients with pre-XDR TB or who had been exposed to BDQ or CFZ.

The Involvement of the Laccase Gene Cglac13 in Mycelial Growth, Germ Tube Development, and the Pathogenicity of Colletotrichum gloeosporioides from Mangoes

Colletotrichum gloeosporioides is one of the most serious diseases that causes damage to mangoes. Laccase, a copper-containing polyphenol oxidase, has been reported in many species with different functions and activities, and fungal laccase could be closely related to mycelial growth, melanin and appressorium formation, pathogenicity, and so on. Therefore, what is the relationship between laccase and pathogenicity? Do laccase genes have different functions? In this experiment, the knockout mutant and complementary strain of Cglac13 were obtained through polyethylene glycol (PEG)-mediated protoplast transformation, which then determined the related phenotypes. The results showed that the knockout of Cglac13 significantly increased the germ tube formation, and the formation rates of appressoria significantly decreased, delaying the mycelial growth and lignin degradation and, ultimately, leading to a significant reduction in the pathogenicity in mango fruit. Furthermore, we observed that Cglac13 was involved in regulating the formation of germ tubes and appressoria, mycelial growth, lignin degradation, and pathogenicity of C. gloeosporioides. This study is the first to report that the function of laccase is related to the formation of germ tubes, and this provides new insights into the pathogenesis of laccase in C. gloeosporioides.

[Clinicopathologic characteristics and prognostic analysis of testicular diffuse large B-cell lymphoma]

Objective: To analyze the clinicopathologic characteristics and prognosis of testicular diffuse large B-cell lymphoma (DLBCL) . Methods: A retrospective analysis was performed on 68 patients with testicular DLBCL admitted to Ruijin Hospital affiliated to Shanghai Jiao Tong University School of Medicine from October 2001 to April 2020. The gene mutation profile was evaluated by targeted sequencing (55 lymphoma-related genes) , and prognostic factors were analyzed. Results: A total of 68 patients were included, of whom 45 (66.2% ) had primary testicular DLBCL and 23 (33.8% ) had secondary testicular DLBCL. The proportion of secondary testicular DLBCL patients with Ann Arbor stage Ⅲ-Ⅳ (P<0.001) , elevated LDH (P<0.001) , ECOG score ≥ 2 points (P=0.005) , and IPI score 3-5 points (P<0.001) is higher than that of primary testicular DLBCL patients. Sixty-two (91% ) patients received rituximab in combination with cyclophosphamide, adriamycin, vincristine, and prednisone (R-CHOP) -based first-line regimen, whereas 54 cases (79% ) underwent orchiectomy prior to chemotherapy. Patients with secondary testicular DLBCL had a lower estimated 5-year progression-free survival (PFS) rate (16.5% vs 68.1% , P<0.001) and 5-year overall survival (OS) rate (63.4% vs 74.9% , P=0.008) than those with primary testicular DLBCL, and their complete remission rate (57% vs 91% , P=0.003) was also lower than that of primary testicular DLBCL. The ECOG scores of ≥2 (PFS: P=0.018; OS: P<0.001) , Ann Arbor stages Ⅲ-Ⅳ (PFS: P<0.001; OS: P=0.018) , increased LDH levels (PFS: P=0.015; OS: P=0.006) , and multiple extra-nodal involvements (PFS: P<0.001; OS: P=0.013) were poor prognostic factors in testicular DLBCL. Targeted sequencing data in 20 patients with testicular DLBCL showed that the mutation frequencies of ≥20% were PIM1 (12 cases, 60% ) , MYD88 (11 cases, 55% ) , CD79B (9 cases, 45% ) , CREBBP (5 cases, 25% ) , KMT2D (5 cases, 25% ) , ATM (4 cases, 20% ) , and BTG2 (4 cases, 20% ) . The frequency of mutations in KMT2D in patients with secondary testicular DLBCL was higher than that in patients with primary testicular DLBCL (66.7% vs 7.1% , P=0.014) and was associated with a lower 5-year PFS rate in patients with testicular DLBCL (P=0.019) . Conclusion: Patients with secondary testicular DLBCL had worse PFS and OS than those with primary testicular DLBCL. The ECOG scores of ≥2, Ann Arbor stages Ⅲ-Ⅳ, increased LDH levels, and multiple extra-nodal involvements were poor prognostic factors in testicular DLBCL. PIM1, MYD88, CD79B, CREBBP, KMT2D, ATM, and BTG2 were commonly mutated genes in testicular DLBCL, and the prognosis of patients with KMT2D mutations was poor.

[Analysis of the clinical features and the risk factors of severe human metapneu movirus-associated community acquired pneumonia in children]

Objective: To investigate the clinical characteristics and the risk factors of severe human metapneumovirus (hMPV)-associated community acquired pneumonia (CAP) in children. Methods: A retrospective case summary was conducted. From December 2020 to March 2022, 721 children who were diagnosed with CAP and tested positive for hMPV nucleic acid by PCR-capillary electrophoresis fragment analysis of nasopharyngeal secretions at the Yuying Children's Hospital, the Second Affiliated Hospital of Wenzhou Medical University were selected as the research objects. The clinical characteristics, epidemiological characteristics and mixed pathogens of the two groups were analyzed. According to CAP diagnostic criteria, the children were divided into the severe group and the mild group. Chi-square test or Mann-Whitney rank and contrast analysis was used for comparison between groups, while multivariate Logistic regression was applied to analyze the risk factors of the severe hMPV-associated CAP. Results: A total of 721 children who were diagnosed with hMPV-associated CAP were included in this study, with 397 males and 324 females. There were 154 cases in the severe group. The age of onset was 1.0 (0.9, 3.0) years, <3 years old 104 cases (67.5%), and the length of hospital stay was 7 (6, 9) days. In the severe group, 67 children (43.5%) were complicated with underlying diseases. In the severe group, 154 cases (100.0%) had cough, 148 cases (96.1%) had shortness of breath and pulmonary moist rales, and 132 cases (85.7%) had fever, 23 cases (14.9%) were complicated with respiratory failure. C-reactive protein (CRP) was elevated in 86 children (55.8%), including CRP≥50 mg/L in 33 children (21.4%). Co-infection was detected in 77 cases (50.0%) and 102 strains of pathogen were detected, 25 strains of rhinovirus, 17 strains of Mycoplasma pneumoniae, 15 strains of Streptococcus pneumoniae, 12 strains of Haemophilus influenzae and 10 strains of respiratory syncytial virus were detected. Six cases (3.9%) received heated and humidified high flow nasal cannula oxygen therapy, 15 cases (9.7%) were admitted to intensive care unit, and 2 cases (1.3%) received mechanical ventilation. In the severe group, 108 children were cured, 42 children were improved, 4 chlidren were discharged automatically without recovery and no death occurred. There were 567 cases in the mild group. The age of onset was 2.7 (1.0, 4.0) years, and the length of hospital stay was 4 (4, 6) days.Compared with the mild group, the proportion of children who age of disease onset <6 months, CRP≥50 mg/L, the proportions of preterm birth, congenital heart disease, malnutrition, congenital airway malformation, neuromuscular disease, mixed respiratory syncytial viruses infection were higher (20 cases (13.0%) vs. 31 cases (5.5%), 32 cases (20.8%) vs. 64 cases (11.3%), 23 cases (14.9%) vs. 44 cases (7.8%), 11 cases (7.1%) vs. 18 cases (3.2%), 9 cases (5.8%) vs. 6 cases (1.1%), 11 cases (7.1%) vs. 12 cases (2.1%), 8 cases (5.2%) vs. 4 cases (0.7%), 10 cases (6.5%) vs. 13 cases (2.3%), χ²=0.42, 9.45, 7.40, 4.94, 11.40, 8.35, 3.52, 6.92, all P<0.05). Multivariate Logistic regression analysis showed that age<6 months (OR=2.51, 95%CI 1.29-4.89), CRP≥50 mg/L (OR=2.20, 95%CI 1.36-3.57), prematurity (OR=2.19, 95%CI 1.26-3.81), malnutrition (OR=6.05, 95%CI 1.89-19.39) were the independent risk factors for severe hMPV-associated CAP. Conclusions: Severe hMPV-associated CAP is most likely to occur in infants under 3 years old and has a higher proportion of underlying diseases and co-infection. The main clinical manifestations are cough, shortness of breath and pulmonary moist rales, fever. The overall prognosis is good. Age<6 months, CRP≥50 mg/L, preterm birth, malnutrition are the independent risk factors for severe hMPV-associated CAP.

Successful pregnancy in the blind hemicavity of Robert's uterus: a rare case report and brief literature review

BACKGROUND

Robert's uterus is a rare congenital anomaly, characterized as an asymmetric septate uterus that has a blind hemicavity with unilateral menstrual fluid retention and a unicornuate hemicavity connecting to the cervix unimpededly. Patients with Robert's uterus generally present with menstrual disorders and dysmenorrhea, and some may have reproductive problems as well, including infertility, recurrent miscarriage, preterm labor and obstetric complications. In this case, we describe a successful pregnancy implanted on the obstructed hemicavity and delivered a liveborn girl. Meanwhile, we highlight diagnostic and therapeutic difficulties in patients with atypical symptoms of Robert's uterus.

CASE PRESENTATION

A 30-year-old Chinese primigravida sought for emergency treatment at 26 weeks and 2 days of gestation because of preterm premature rupture of membranes (PPROM). At the age of 19, the patient was misdiagnosed with hyperprolactinemia and pituitary microadenoma for showing symptom of hypomenorrhea and was suspected to have a uterine septum in the first trimester. She was diagnosed with Robert's uterus at 22 weeks of gestation by repetitious prenatal transvaginal ultrasonography, which was subsequently confirmed by magnetic resonance imaging. At 26 weeks and 3 days of gestation, the patient was suspected to have oligohydramnion, irregular uterine contraction, and umbilical cord prolapse, and she expressed a strong will of saving the baby. Emergency cesarean delivery was performed and a small hole, together with several weak spots, was found at the lower and back wall of the septum of the patient. The treatment was effective and both the mother and the infant, who had an extremely low birth weight, were discharged in good health conditions.

CONCLUSIONS

Pregnancy in the blind cavity of Robert's uterus with living neonates is incredibly rare. In our case, the favorable outcome may result from the unusual hole found at the septum, which may play a role in communicating amniotic fluid between the two hemicavities so to keep the neonate alive. we highlight the importance of early diagnosis and pre-pregnancy treatment of this uterine malformation, and the timely termination of pregnancy, for improving birth quality and reducing mortality.

Biological interpretation of the sporadic sputum smear-positive-culture-negative outcome for patients with tuberculosis undertaking treatments

Introduction

The objective of the study was to identify the causes of smear-positive-culture-negative (S+/C-) outcomes of patients with tuberculosis during the treatment course.

Methods

A laboratory-based retrospective study was performed at the Beijing Chest Hospital in China. Within the study period, all patients with pulmonary tuberculosis (PTB) who undertook anti-TB treatments and yielded smear positive outcomes with simultaneous culture outcomes on sputa were considered. Patients were classified into three groups: (I) performed LJ medium culture only; (II) performed BACTEC MGIT960 liquid culture only; and (III) performed both LJ culture and MGIT960 culture. The S+/C- rates of each group were analyzed. The clinical medical records regarding patient category, follow-up bacteriologic examination data, and treatment response were investigated.

Results

In total, 1,200 eligible patients were enrolled, and the overall S+/C- rate was 17.5% (210/1,200). Group I had obviously higher S+/C- rate (37%) than group II (18.5%) and group III (9.5%). When solid and liquid cultures were considered independently, the S+/C- outcome was observed more frequently in the solid culture group than in the liquid culture group (30.4%, 345/1,135 vs. 11.5%, 100/873; p < 0.001, χ² = 102.64). Among the 102 S+/C- patients who had follow-up cultures performed, 35 (34.3%) had positive culture outcomes. Whereas among the 67 patients with follow-up information for more than 3 months but without supportive bacteriological evidence, 45 (67.2%, 45/67) had unfavorable prognosis (including relapse and unimproved conditions), and only 22 (32.8%, 22/67) patients had improved conditions. Compared with new cases, retreated cases produced S+/C- outcomes more frequently and had more chances to be cultivated bacilli successfully afterward.

Conclusions

Among our patients, the sporadic smear positive and culture negative outcomes for sputa are more likely associated with the technical failures of culture than with dead bacilli, and this is especially noteworthy for LJ medium culture.

In vitro and Intracellular Antibacterial Activity of Sudapyridine (WX-081) Against Tuberculosis

Background

Sudapyridine (WX-081) has exhibited equivalent efficacy than its counterpart parent drug bedaquiline (BDQ) but better safety profile against Mycobacterium tuberculosis (Mtb). Our study was aimed to evaluate in vitro activity of WX-081 against the clinical isolates of Mtb with different drug-resistance profiles and the intracellular bactericidal activity against the reference strain.

Methods

The minimum inhibitory concentrations (MICs) of WX-081 and BDQ were tested against 114 Mtb clinical isolates. The intracellular activity of WX-081 and BDQ against the Mtb reference strain H37Rv in THP-1 cells was also evaluated in parallel.

Results

The MICs for WX-081 of the enrolled isolates ranged from 0.0156 μg/mL to 1 μg/mL. The MIC₅₀ and MIC₉₀ of WX-081 were, respectively, 0.25 μg/mL and 0.5 μg/mL, with 95.6% of the enrolled strains having MICs ≤0.25 μg/mL. For a given strain, the MIC value of WX-081 was generally equivalent to or 2-fold than MIC of BDQ. The intracellular bacterial killing was acquired with the tested drug concentrations that were presumed attainable during clinical usage.

Conclusion

WX-081 exhibited potent efficacy against the clinical isolates in vitro. The intracellular killing effect of sudapyridine against the reference strain supports its potential efficacy in treating TB patients.

Maize resistance to witchweed through changes in strigolactone biosynthesis

Maize (Zea mays) is a major staple crop in Africa, where its yield and the livelihood of millions are compromised by the parasitic witchweed Striga. Germination of Striga is induced by strigolactones exuded from maize roots into the rhizosphere. In a maize germplasm collection, we identified two strigolactones, zealactol and zealactonoic acid, which stimulate less Striga germination than the major maize strigolactone, zealactone. We then showed that a single cytochrome P450, ZmCYP706C37, catalyzes a series of oxidative steps in the maize-strigolactone biosynthetic pathway. Reduction in activity of this enzyme and two others involved in the pathway, ZmMAX1b and ZmCLAMT1, can change strigolactone composition and reduce Striga germination and infection. These results offer prospects for breeding Striga-resistant maize.

Long non-coding RNA PVT1 promotes the proliferation, migration and EMT process of ovarian cancer cells by regulating CTGF

Ovarian cancer remains one of the most common gynecological malignancies with a poor prognosis. The present study investigated the roles of long non-coding RNA plasmacytoma variant translocation 1 (lncRNA PVT1) in the regulation of the malignant phenotype of ovarian cancer cells, including cell proliferation, migration, invasion and epithelial-mesenchymal transition (EMT). SKOV3 and CAOV3 cells were transfected with small interfering RNA (siRNA) targeting lncRNA PVT1 (si-PVT1) or control siRNA and the si-PVT1 transfected cells were co-cultured with recombinant human connective tissue growth factor (rhCTGF). The proliferation, migration and invasion abilities of the cells were examined via Cell Counting Kit-8, colony formation, wound-healing and Transwell assays. The relative expression levels of lncRNA PVT1, CTGF, E-cadherin and vimentin were analyzed using reverse transfection-quantitative polymerase chain reaction, and western blotting was employed to detect the protein levels of CTGF, E-cadherin and vimentin. The expression of lncRNA PVT1 was significantly reduced in SKOV3 and CAOV3 cells following transfection with si-PVT1. In addition, the proliferation, migration and invasion abilities of SKOV3 and CAOV3 cells were repressed following lncRNA PVT1 knockdown. The knockdown of lncRNA PVT1 also reduced the expression of CTGF and vimentin, and increased the expression of E-cadherin. The changes in the proliferation, migration and invasion of the cells induced by transfection with si-PVT1 were partially attenuated in the presence of rhCTGF. Furthermore, co-culture with rhCTGF reversed the si-PVT1-induced changes in the expression of EMT-associated proteins. In conclusion, lncRNA PVT1 promotes the proliferation, migration, invasiveness and EMT process of ovarian cancer cells, and CTGF contributes to the effect of lncRNA PVT1.

[Bibliometric analysis of publications pertaining to artemisinin resistance in Plasmodium falciparum based on Web of Science from 2011 to 2022]

OBJECTIVE

To analyze the global literature output and citation of publications pertaining to artemisinin (ART) resistance in Plasmodium falciparum from 2011 to 2021, so as to provide insights into researches on resistance of P. falciparum to ART.

METHODS

The publications pertaining to ART resistance in P. falciparum were retrieved from the Science Citation Index Expanded (SCIE) database in Web of Science during the period from January 2011 through May 2022. The subject, journal, country, affiliation and author distributions and citations of publications were descriptively analyzed.

RESULTS

A total of 1 640 publications pertaining to ART resistance in P. falciparum were retrieved in the SCIE database during the period from January 2011 through May 2022, and the number of publications appeared an overall tendency towards a rise during the study period. These articles were published in 343 journals, and the three most productive journals included Malaria Journal (341 publications, 20.79%), Antimicrobial Agents and Chemotherapy (141 publications, 8.60%), American Journal of Aropical Medicine and Hygiene (68 publications, 4.15%), with infectious diseases (565 publications, 34.45%), parasitology (531 publications, 32.38%), and tropical medicine (517 publications, 31.54%) as the predominant subject. The three most productive countries included the United States of America (627 publications, 38.23%), United Kingdom (395 publications, 24.08%), and Thailand (294 publications, 17.94%), with total citations of 25 280, 18 622 and 15 474, respectively, and the most productive countries included Mahidol University (Thailand), Oxford University (England) and London University (England), with 234, 220 publications and 142 publications and 15 058, 15 421 citations and 6 191 citations, respectively. The three most productive authors were all from Mahidol University, with 85, 77 and 63 publications, respectively; and among the three most cited authors, two were from Mahidol University, Thailand, with 8 623 and 7 961 total citations, and one from National Institutes of Health, the United States of America, with 6 267 total citations. A total of 138 articles were published by Chinese scientists, with 3 434 total citations, and National Institute of Parasitic Diseases of Chinese Center for the Diseases Control and Prevention was the most productive Chinese institution, with 35 publications, 1 165 total citations and 33.29 citations per publication.

CONCLUSIONS

The literature output of ART resistance in P. falciparum was relatively high in the United States of America, Europe, and Southeast Asian countries during the period from 2011 to 2021, with a relatively high academic impact. Publications in Malaria Journal and Antimicrobial Agents and Chemotherapy are recommended to be paid much attention by Chinese scientists to understand the latest advances and extend the research interests.

Novel oxazolidinones harbor potent in vitro activity against the clinical isolates of multidrug-resistant Mycobacterium tuberculosis in China

OBJECTIVE

To investigate the in vitro activities of five oxazolidinones in parallel against the reference strains of different mycobacterial species and clinical isolates of Mycobacterium tuberculosis (Mtb), and shed light on the differences in the efficacy of these homolog drugs.

MATERIALS AND METHODS

The minimum inhibitory concentrations (MICs) of linezolid, tedizolid, sutezolid, delpazolid, and contezolid against 16 mycobacterial reference strains and 69 M. tuberculosis clinical isolates, including 17 drug-susceptible isolates and 52 multidrug-resistant (MDR) isolates, were determined by microplate alamarBlue assay (MABA). The intracellular killing activities of contezolid and linezolid against Mtb H37Rv were compared. In addition, mutations in the linezolid resistance-related genes (rplC, rplD, and 23S rRNA) of the Mtb clinical isolates were also analyzed.

RESULTS

Tedizolid exhibited the strongest inhibitory activities against the reference strains of both rapidly growing mycobacteria (RGM) and slowly growing mycobacteria (SGM), among the tested oxazolidinones. In contrast, sutezolid only manifested potent activity against reference strains of SGM. Linezolid, delpazolid, and contezolid were less active against the non-tuberculous mycobacterial references. For the Mtb clinical isolates, the antimicrobial action was ranked as: sutezolid > tedizolid > contezolid and linezolid > delpazolid, whereas no difference between drug-sensitive and multiple drug-resistant isolates was observed. Notably, contezolid demonstrated obviously superior intracellular antimicrobial activity than linezolid. Few strains harbored mutations in rrl gene or rplD genes, although these strains had drug susceptible profiles to linezolid.

CONCLUSION

Different oxazolidinones can have discrepant antimicrobial activity against different mycobacterial species, or have different manifestations out of cell or in cell. Understanding these differences would be helpful in choosing the appropriate drug in clinical practice.

Rapid quasi-periodic oscillations in the relativistic jet of BL Lacertae

Blazars are active galactic nuclei (AGN) with relativistic jets whose non-thermal radiation is extremely variable on various timescales^1-3. This variability seems mostly random, although some quasi-periodic oscillations (QPOs), implying systematic processes, have been reported in blazars and other AGN. QPOs with timescales of days or hours are especially rare⁴ in AGN and their nature is highly debated, explained by emitting plasma moving helically inside the jet⁵, plasma instabilities^6,7 or orbital motion in an accretion disc^7,8. Here we report results of intense optical and γ-ray flux monitoring of BL Lacertae (BL Lac) during a dramatic outburst in 2020 (ref. ⁹). BL Lac, the prototype of a subclass of blazars¹⁰, is powered by a 1.7 × 10⁸ M_Sun (ref. ¹¹) black hole in an elliptical galaxy (distance = 313 megaparsecs (ref. ¹²)). Our observations show QPOs of optical flux and linear polarization, and γ-ray flux, with cycles as short as approximately 13 h during the highest state of the outburst. The QPO properties match the expectations of current-driven kink instabilities⁶ near a recollimation shock about 5 parsecs (pc) from the black hole in the wake of an apparent superluminal feature moving down the jet. Such a kink is apparent in a microwave Very Long Baseline Array (VLBA) image.

The Practical Value of Xpert MTB/RIF Ultra for Diagnosis of Pulmonary Tuberculosis in a High Tuberculosis Burden Setting: a Prospective Multicenter Diagnostic Accuracy Study

Due to the probability of decreased specificity, the practical value of performing the Xpert MTB/RIF Ultra (Xpert Ultra) assay over the Xpert assay for diagnosing pulmonary tuberculosis (TB) and rifampicin (RIF) resistance in a high TB burden setting was evaluated. Participants were recruited consecutively in three tertiary hospitals in China and allocated to the TB case detection and/or rifampicin (RIF) resistance detection group. Each sputum specimen was subjected to smear, MGIT960 liquid culture, and Xpert, and Xpert Ultra assay in parallel. Drug susceptibility testing was conducted for all recovered isolates in the RIF resistance detection group. In total, 1,079 patients were recruited to the case detection group and 450 to the RIF resistance detection group. Xpert Ultra had higher sensitivity than Xpert (92.26%, 322/349 versus 89.40%, 312/349; P = 0.006), whereas the most prominent increase was identified in the smear-negative patients (83.70% versus 78.52%; P = 0.039). The specificity of Xpert Ultra was slightly lower than that of Xpert (96.30%, 495/514 versus 98.25%, 505/514; P = 0.055). Reclassifying trace results as negative resulted in a 4.01% loss of sensitivity (from 92.26% to 88.25%) accompanied by a 1.37% gain in specificity (from 96.30% to 97.67%). Both the sensitivity (97.64% versus 99.21%, P = 0.313) and specificity (96.90% versus 97.21%, P = 0.816) of Xpert Ultra and Xpert for detection RIF resistance were comparable. In conclusion, Xpert Ultra could improve the diagnosis of smear-negative pulmonary TB in contrast to the Xpert assay. A high percentage of TB history did not significantly decrease the specificity of the test, which supports the potential role of Xpert Ultra as an initial diagnostic tool for TB. IMPORTANCE Xpert Ultra is more sensitive than Xpert, especially in smear-negative TB. A high percentage of TB history in the non-TB population did not significantly affect the reliability of the assay, which supports the potential role of Xpert Ultra as an initial diagnostic tool for TB.

Trends and Species Diversity of Non-tuberculous Mycobacteria Isolated From Respiratiroy Samples in Northern China, 2014–2021

Background

Pulmonary non-tuberculous mycobacteria (NTM) infection has become a public health concern in China and around the world. The objective of this study was to describe the longitudinal changes in the frequency and diversity of NTM in northern China.

Methods

We retrospectively analyzed data on mycobacterium species in Beijing Chest Hospital from January 2014 to December 2021. The isolates were identified to species level by targeted DNA sequencing.

Results

After excluding duplicates, 1,755 NTM strains were analyzed, which were from 27 provinces in China over 8 years. Among all mycobacteria, the proportion of NTM increased each year, from 4.24% in 2014 to 12.68% in 2021. Overall, 39 different NTM species were identified, including 23 slow growing mycobacteria (SGM) and 16 rapid growing mycobacteria (RGM). The most common species were M. intracellulare (51.62%), M. abscessus (22.22%), M. kansasii (8.32%), M. avium (7.75%) and M. fortuitum (2.05%). The number of NTM species identified also increased each year from 9 in 2014 to 26 in 2021. Most species showed stable isolation rates over the years; however, the proportion of M. avium increased from 3.85 to 10.42% during the study period. Besides, 81 non-mycobacteria strains, including Gordonia (21 isolates), Nocardia (19 isolates) and Tsukamurella (17 isolates), etc., were also discovered.

Conclusion

The proportion of NTM and species diversity increased considerably in northern China from 2014 to 2021. M. intracellulare was the most common NTM isolated among respiratory specimens, followed by M. abscessus and M. kansasii. Rare NTM species and non-mycobacteria pathogens also need attention.

P-468 Organotypic culture of testicular tissue from infant boys with cryptorchidism

Study question

Can organotypic culture support the survival and maturation of germ cells and niche-related cells within testicular tissue from infant boys with cryptorchidism?

Summary answer

The testicular structure and the number of germ cells were maintained during organotypic culture, whereas Sertoli cells and peritubular myoid cells (PTMCs) matured.

What is known already

Testicular tissue cryopreservation (TTC) is a strategy to safeguard the fertility of prepubertal boys who face a risk of infertility. Organotypic culture of immature testicular tissue from mice achieved production of spermatozoa. Similarly, the culture of human fetal gonads resulted in the generation of competent spermatids. However , in vitro spermatogenesis by organotypic culture of human prepubertal testicular tissue has not been achieved. It is also unknown whether germ cells as well as its niche-related cells, in testicular tissue from infant boys with cryptorchidism, can maintain and mature under in vitro conditions.

Study design, size, duration

Testicular tissue was cryopreserved from four infant boys with bilateral cryptorchidism undergoing orchidopexy (age range: 0.5-1.4 years), as part of a fertility preservation program. Culture media with and without retinoic acid were tested. Testicular fragments were harvested at 30 days and 60 days after culture and evaluated by histological assessment of tissue structure, germ cell development, and immunohistochemical staining for germ cell and somatic cell markers.

Participants/materials, setting, methods

Cryopreserved-thawed testicular tissue was cut into fragments (1-2 mm3) and placed on top of agarose gel stands and cultured at 34oC with 5% CO2 in Minimum Essential Medium-alpha supplemented with knockout serum replacement, human umbilical cord plasma, Activin A, hormones, growth factors, with or without retinoic acid. Immunohistochemical analyses were performed using germ cell markers (MAGE-A, GAGE, and VASA), Sertoli cell maturation markers (AMH, AR, SOX9), PTMC marker (alpha-SMA).

Main results and the role of chance

Following the 60-day culture, the lumen of the seminiferous tubules had developed. The number of germ cells per tubule remained stable during this period. However, no further germ cell maturation was observed. Germ cells showed different phenotypes of MAGEA, GAGE, and VASA expression with no significant difference in number. The number of SOX9-positive Sertoli cells was significantly increased from 30 days to 60 days of culture (p &lt;0.0001). No difference in AMH expression was observed, while AR expression in Sertoli cells was induced during culture. Alpha-SMA expression was detected in the PTMCs surrounding the seminiferous tubules. The two different culture conditions, with and without retinoic acid in the culture media, did not affect cell survival or maturation.

Limitations, reasons for caution

The small number of testicular biopsies available is a limitation.

Wider implications of the findings

Our organotypic culture conditions support the long-term survival of germ cells in testicular tissue from infant boys with cryptorchidism. Thus, further studies are needed to induce the maturation of germ cells under similar experimental conditions.

Trial registration number

not applicable

A Bacterial Isolate Capable of Quenching Both Diffusible Signal Factor- and N-Acylhomoserine Lactone-Family Quorum Sensing Signals Shows Much Enhanced Biocontrol Potencies

N-Acylhomoserine lactone (AHL) and diffusible signal factor (DSF) molecules are two families of widely conserved quorum sensing (QS) signals. Quorum quenching (QQ) via enzymatic inactivation of QS signals is a promising strategy of biocontrol. In the search for biocontrol agent quenching both AHL and DSF signals, it has been recently identified that DSF-quenching biocontrol agent Pseudomonas sp. HS-18 contains at least three genes (aigA, aigB, and aigC) encoding AHL-acylases displaying strong AHL-acylase activities on various AHLs. Among them, AigA and AigC presented broad-spectrum enzyme activity against AHLs, while AigB preferred longer AHLs. Interestingly, transcriptional expression of aigC could be significantly induced by AHL signals. Heterologous expression of aigA-C in Burkholderia cenocepacia and Pseudomonas aeruginosa resulted in drastically decreased AHL accumulation, virulence factor production, biofilm formation, motility, and virulence on plants. Significantly, the two types of QQ mechanisms in HS-18 showed a strong and much desired synergistic effect for enhanced biocontrol potency against AHL- and DSF-dependent pathogens.

Doubled Nontuberculous Mycobacteria Isolation as a Consequence of Changes in the Diagnosis Algorithm

Background

Nontuberculous mycobacteria (NTM) and their associated diseases remain neglected. Through minor modifications in our diagnostic algorithm, we observed an unexpected higher number of cultivable NTM isolates. Therefore, a retrospective study was performed thoroughly to investigate the effect of changed laboratory procedures on NTM isolation in a specialized tuberculosis hospital.

Methods

NTM isolation rates and composition of NTM species were compared for the two diagnostic algorithms: (1) by using traditional p-nitrobenzoic acid (PNB) selective medium as a preliminary test to identify NTM isolates among the positive cultures (procedure I) and (2) by using the MPT64 antigen detection method to distinguish between Mycobacterium tuberculosis complex (MTBC) isolates and possible NTM isolates after a positive MGIT960 liquid culture (procedure II).

Results

The NTM isolation rate in procedure II was significantly higher than the procedure I (18.08% vs 9.71%; P<0.001). A noticeable increase in the ratio of NTM isolates among the identified mycobacteria was observed over the studied years (ie, from 58.18% in 2019 to 72.93% in 2021), which indicated a more precise prescription of species identification test after prompt information was provided in procedure II. In addition, the consistency of the identified species using multiple specimens from the same patient did not present a significant difference between the procedures.

Conclusion

According to our study, NTM infection might be far more underestimated than it is. A diagnostic procedure combining MGIT960 culture and MPT64 antigen detection could timely and easily identify clues of NTM isolates and improve the diagnosis of NTM infections.

[Value of albumin RNAscope in situ hybridization in diagnosis and differential diagnosis of hepatocellular carcinoma]

Objective: To investigate the utility of albumin RNAscope in situ hybridization in the diagnosis and differential diagnosis of hepatocellular carcinoma and its mimics. Methods: One hundred and fifty-two cases of hepatocellular carcinoma and its mimics and 33 cases of normal tissue were selected from the pathology database of the Department of Pathology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine from January 2013 to December 2019. Tissue microarrays were constructed and RNAscope in situ hybridization was performed to detect the expression of albumin mRNA. Results: No albumin mRNA expression was detected in normal tissues except for the liver. All hepatocellular carcinoma regardless of its degree of differentiation and primary or metastatic nature had detectable albumin mRNA, with strong and diffuse staining in 90.7% (49/54) of cases. While the positive rate of HepPar-1, Arg-1 or one of them by immunohistochemistry was 87.0% (47/54), 85.2% (46/54) and 92.6% (50/54) respectively. The positive rates of albumin mRNA in intrahepatic cholangiocarcinoma and biphenotypic hepatocellular carcinoma were 7/15 and 9/10, respectively. The former showed focal or heterogeneous staining, while the latter showed strong and diffuse staining. The positive rate of hepatoid adenocarcinoma was 8/19, and the albumin expression could be diffuse or focal. Sporadic cases of poorly differentiated gastric adenocarcinoma and metastatic colon adenocarcinoma showed focal staining of albumin mRNA. Conclusions: Detection of albumin mRNA by RNAscope in situ hybridization is of great value for the diagnosis and differential diagnosis of HCC, and the sensitivity may be improved by combining with HepPar-1 and Arg-1. It also offers different diagnostic clues according to different expression patterns.