Human adenovirus type 14p1 (HAdV-14p1) is associated with severe respiratory illness. Using human airway organoids, we characterized the cellular tropism, infection dynamics, and cellular response to HAdV-14p1, and evaluated the antiviral efficacy of cidofovir. HAdV-14p1 robustly infected and replicated in human airway organoids, particularly targeting ciliated, basal, and goblet cells. CCL5, CXCL10, CXCL11, and TNFSF13B were significantly upregulated upon HAdV-14p1 infection, indicating inflammatory activation. Pathway enrichment analysis revealed that upregulated genes were enriched in p53 signaling, cytokine-cytokine receptor interaction, and NOD-like receptor signaling pathways, whereas downregulated genes were linked to focal adhesion, tight junction, metabolic pathways, and oxidative phosphorylation pathways. Furthermore, treatment with cidofovir effectively inhibited viral replication with low cytotoxicity. Our findings highlight the robust replication and proinflammatory response that shape HAdV-14p1 pathogenesis and underscore the value of organoid systems in probing virus-host interactions and evaluating candidate antiviral strategies.

Purpose:Klebsiella pneumoniae harbors a gene cluster, polyketide synthase island (PKS), which is responsible for colibactin synthesis which induces double-stranded DNA breaks and associated with increased pathogenicity and cancer development. However, there is limited information on pks-positive K. pneumoniae in cancer patients in China. This study aimed to investigate the prevalence and molecular characteristics of K. pneumoniae harboring the pks island in patients with cancer in China and to explore its potential pathogenicity and clinical significance. Methods:Among 279 nonrepetitive K. pneumoniae isolated from all cancer patients in China, the presence of pks genes were determined by PCR and the molecular characteristics were detected by whole-genome sequencing. Clinical characteristics and antimicrobial susceptibility were also investigated. Results:The pks gene cluster was detected in 35 (12.54%) of the 279 isolates. All isolates were less resistant to most antimicrobial agents, and there were no significant differences in the rates of susceptibility between pks-positive and pks-negative isolates to most antibiotics, except for sulfonamides. Among pks-positive isolates, ST23 (19, 54.29%) and K1 (17, 48.57%) were the dominant sequence types and serotypes, respectively, and the majority harbored multiple virulence genes, including aerobactin, enterobactin, salmochelin, and yersiniabactin. Conclusion:The distribution of pks-positive K. pneumoniae in different types of cancer combined with its hypervirulent determinants highlighted the potential pathogenicity of genotoxins, which requires close clinical attention and epidemic tracking.

Programmed cell death is a pivotal mechanism of cell-autonomous immune defense against viral infections. Recent studies indicate that both blocking and promoting cell death negatively affect coronavirus replication, implying that coronaviruses may fine-tune cell death pathways to optimize their propagation. However, the mechanisms underlying this remain poorly understood. Here, it is verified that coronaviruses induce the formation of a Z-DNA-binding protein 1 (ZBP1)-initiated cell death complex involving ZBP1, Z-RNA, receptor-interacting serine/threonine-protein kinase 3 (RIPK3), and caspase-8, thereby triggering apoptosis, pyroptosis, and necroptosis in human bronchial epithelial cells. To impede the activation of apoptosis and pyroptosis, NSP5 and ORF6 of SARS-CoV-2 concurrently inhibit caspase-8 activity by targeting its large and small subunits, respectively. Additionally, NSP13, the viral helicase, interacts with RIPK3 to impair its binding to ZBP1, thus suppressing ZBP1-initiated necroptosis. This inhibitory effect on cell death is likely conserved across β-coronaviruses. Furthermore, co-infection of influenza A virus and SARS-CoV-2 is demonstrated to exacerbate disease severity, although the mechanisms remain unclear. These findings suggest that β-coronavirus-induced inhibition of cell death enhances influenza A virus replication and worsens inflammation during their co-infection, ultimately increasing mortality in mice. This research provides valuable insights into the regulation of coronavirus-induced cell death, offering potential therapeutic strategies for combating highly pathogenic coronavirus infections.

The clinical effects of pediatric human adenovirus (HAdV) 7 infection are more severe than those caused by HAdV-3. This increased pathogenesis is likely associated with a higher viremia, i.e., a higher presence of HAdV-7 in blood, but the mechanisms that explain this are poorly understood. Herein, we tested the polarization of entry and release for both HAdV-7 or HAdV-3 in epithelial and endothelial cells, and evaluated the effect of these viruses on cellular junctions of epithelial cells, measuring transepithelial electrical resistance and paracellular flux. We show that epithelial cells are infected by both viruses via either basolateral or apical sides, but are released apically. In contrast, in endothelials cells, both entry and release can occur from either side. The replication capacity was higher for HAdV-7 than for HAdV-3, and infection led to more severe epithelial barrier damage, compromising tight junction integrity. These effects may be related to the higher viremia observed previously in HAdV-7. The way in which HAdV-7 traverses epithelial and endothelial barriers to establish a new infection offers new perspectives to treat its pathogenicity.

AbstractObjectiveUnder the prevention and control measures of COVID‐19, the epidemiological situation of respiratory pathogens is not well known. Understanding the patterns of respiratory pathogens epidemiology under the prevention and control measures of COVID‐19 is important to guide resource allocation for existing and future treatment and prevention strategies.MethodsIn total, 659 fever outpatients nasopharyngeal swabs were collected at fever illness onset during June in 2022 at the First Hospital of Guangzhou Medical University. Swabs were tested by real‐time fluorescent single‐tube multiplex polymerase chain reaction (PCR) for 12 respiratory pathogens. Moreover, 108 of the 659 swabs were tested for influenza virus antigen.ResultsAt least one pathogen was detected in 477 (72.38%) of 659 fever outpatients with multiple pathogens identified in 25 (3.79%). The highest multiple infectious pattern is parainfluenza virus in combination with influenza (five cases). Influenza A virus (IFA), human rhinovirus (HRV), and parainfluenza virus are the three leading virus pathogens with proportions of 64.64%, 5.01%, and 2.88%. School‐age children and adult groups have the highest pathogens positivity rate of 81.28% and 83.87%.ConclusionA high proportion of adolescents and adults has respiratory pathogens detected during fever illnesses during June in 2022 under the prevention and control of COVID‐19. These data indicate that diagnosis, prevention, and control of respiratory tract infection should be paid attention under the prevention and control of COVID‐19.

Background: To explore the tropism and replication proficiency of specific human adenoviruses, namely HAdV-7 and HAdV-3, across a spectrum of human cell lines, and to elucidate the relationship between viral infection and the levels of hDSG2 and hCD46 receptor expression. Methods: We employed a variety of human cell lines originating from diverse tissues to evaluate viral replication. Viral titers were determined using a standard plaque assay, and cell infection was evaluated by immunofluorescence staining for viral hexon protein. Flow cytometry was used to assess the surface expression of hDSG2 and hCD46. The statistical analysis was conducted with GraphPad Prism version 6 software. Results: HAdV-7 demonstrated higher replication efficiency than HAdV-3 in most cell lines, with significant replication observed in Hep-2, Calu-3, HEK-293, and HeLa cells. The expression of hDSG2 and hCD46 correlated with viral susceptibility, indicating that these receptors are vital for viral adhesion and penetration. Notably, HAdV-7 showed a stronger association with hDSG2, which may explain its increased pathogenicity. Conclusions: Our study provides evidence that HAdV-7 has a broader tropism and higher replication efficiency in human cell lines compared to HAdV-3, with hDSG2 being a potential target for antiviral interventions. These results deepen our comprehension of HAdV-7 pathogenesis and could inform the creation of innovative treatment approaches for adenovirus infections.

BACKGROUNDS:Mycoplasma pneumoniae (M. pneumoniae) is a common pathogen causing respiratory diseases in children. This study aimed to characterize epidemiological and disease severity shifts of M. pneumoniae: infections in Guangzhou, China during and after the coronavirus disease 2019 (COVID-19) pandemic. METHODS:Throat swab samples were obtained from 5405 hospitalized patients with symptoms of acute respiratory infections to detect M. pneumoniae. Differences in epidemiological and clinical characteristics of M. pneumoniae: infections were investigated during 2020-2022 and after COVID-19 pandemic (2023). RESULTS:M. pneumoniae were detected in 849 (15.6%, 849/5405) patients. The highest annual positive rate was 29.4% (754/2570) in 2023, followed by 5.3% (72/1367) in 2022, 1.2% (12/1015) in 2021, and 2.0% (11/553) in 2020, with significantly increasing annual prevalence from 2020 to 2023. M. pneumoniae incidence peaked between July and December post-COVID-19 pandemic in 2023, with the highest monthly positive rate (56.4%, 165/293). Clinical characteristics and outcomes of patients with M. pneumoniae did not vary between periods during and after COVID-19 pandemic except that patients with M. pneumoniae post-COVID-19 pandemic were more likely to develop fever. Patients with severe M. pneumoniae pneumonia (SMPP) were more likely to develop respiratory complications, myocardial damage, and gastrointestinal dysfunction than those with non-SMPP. Patients with SMPP had lower lymphocytes, CD3+ T cells, CD4+ T cells, CD8+ T cells, B cells, and higher IL-4, IL-6, IL-10 levels than those with non-SMPP. Bronchoalveolar lavage fluid specimens from infected patients were obtained to identify macrolide resistance mutations. Macrolide-resistant M. pneumoniae (MRMP) proportion in 2023 was 91.1% (215/236). CONCLUSION:Outbreaks of M. pneumoniae: occurred in Guangzhou, China in 2023 upon Non-pharmaceutical interventions easing. Despite the increasing incidence of M. pneumoniae, the disease severity remained similar during and after the COVID-19 pandemic.

Background: Tuberculosis (TB) remains a significant global health emergency caused by Mycobacterium tuberculosis (Mtb). The epidemiology, transmission, genotypes, mutational patterns, and clinical consequences of TB have been extensively studied worldwide, however, there is a lack of information regarding the epidemiology and mutational patterns of Mtb in Pakistan, specifically concerning the prevalence of multi-drug resistant TB (MDR-TB). Methods: This study aimed to investigate the incidence of Mtb and associated mutational patterns using the line probe assay (LPA). Previous studies have reported a high frequency of mutations in the rpoB, inhA, and katG genes, which are associated with resistance to rifampicin (RIF) and isoniazid (INH). Therefore, the current study utilized LPA to detect mutations in the rpoB, katG, and inhA genes to identify multi-drug resistant Mtb. Results: LPA analysis of a large pool of Mtb isolates, including samples from 241 sputum-positive patients, revealed that 34.85% of isolates were identified as MDR-TB, consistent with reports from various regions worldwide. The most prevalent mutations observed were rpoB S531L and inhA promoter C15T, which were associated with resistance to RIF and INH, respectively. Conclusions: This study highlights the effectiveness of GenoType MTBDRplus and MTBDRsl assays as valuable tools for TB management. These assays enable rapid detection of resistance to RIF, INH, and fluoroquinolones (FQs) in Mtb clinical isolates, surpassing the limitations of solid and liquid media-based methods. The findings contribute to our understanding of MDR-TB epidemiology and provide insights into the genetic profiles of Mtb in Pakistan, which are essential for effective TB control strategies.

Visualized gene detection based on the CRISPR-Cas12/CRISPR-Cas13 technology and lateral flow assay device (CRISPR-LFA) has shown great potential in point-of-care testing sector. Current CRISPR-LFA methodology mainly utilizes conventional immuno-based LFA test strips, which could visualize whether the reporter probe is trans-cleaved by Cas protein, indicating the target positive detection. However, conventional CRISPR-LFA usually produces false-positive results in target negative assay. Herein, a nucleic acid Chain Hybridization-based Lateral Flow Assay platform, named CHLFA, has been developed to achieve the CRISPR-CHLFA concept. Different from the conventional CRISPR-LFA, the proposed CRISPR-CHLFA system was established based on the nucleic acid hybridization between the GNP-probe embedded in test strips and ssDNA (or ssRNA) reporter from CRISPR (LbaCas12a or LbuCas13a) reaction, which eliminated the requirement of immunoreaction in conventional immuno-based LFA. The assay realized the detection of 1-10 copy of target gene per reaction within 50 min. The CRISPR-CHLFA system achieved highly accurate visual detection of target negative samples, thus overcoming the false-positive problem that often produced in assays using conventional CRISPR-LFA. The CRISPR-CHLFA platform was further adopted for the visual detection of marker gene from SASR-CoV-2 Omicron variant and Mycobacterium tuberculosis (MTB), respectively, and 100% accuracy for the analysis of clinical specimens (45 SASR-CoV-2 specimens and 20 MTB specimens) was obtained. The proposed CRISPR-CHLFA system could provide an alternative platform for the development of POCT biosensors and can be widely adopted in accurate and visualized gene detection.

ABSTRACT The polymorphism at amino acid 17 of quinolone resistance-determining region of GyrA has been stated with a potential role in fluoroquinolone susceptibility in different mycobacterial species. However, no study has provided dependable evidence so far. Here, we verified that gene-edited Mycobacterium abscessus mutants bearing Ser/Gly at this position were more susceptible to fluoroquinolones than their parent strain and the revertant that supports mycobacteria containing Ser/Gly at this position were more susceptible to fluoroquinolones than those containing Ala. IMPORTANCE Fluoroquinolones (FQs) play a key role in the treatment regimens against tuberculosis and non-tuberculous mycobacterial infections. However, there are significant differences in the sensitivities of different mycobacteria to FQs. In this study, we proved that this is associated with the polymorphism at amino acid 17 of quinolone resistance-determining region of Gyrase A by gene editing. This is the first study using CRISPR-associated recombination for gene editing in Mycobacterium abscessus to underscore the contribution of the amino acid substitutions in GyrA to FQ susceptibilities in mycobacteria.

ObjectiveThe current paper aims to discuss the development of a virtual simulation experiment teaching system and review its effectiveness in improving the teaching of clinical skills to college medical students.MethodsCollaborators used 3D Studio Max, Unity 3D and Visual Studio to develop four modules: laboratory thinking training, biosafety training, gene testing and experimental assessment. Teaching was conducted and a virtual software program was used for evaluation of the students.ResultsThe laboratory safety training system, virtual gene experiment system and experimental assessment system were developed. The results of the questionnaire survey show that the software provides good interactivity and guidance. The interest of medical students in study is improved and they received training in clinical experimental thinking. Student evaluation assists their scientific research practice, and can improve the awareness of biosafety.ConclusionThe virtual simulation experiment teaching system, when applied in the teaching of undergraduate and postgraduate experiment courses, can bring about rapid improvements in the following areas: biosafety awareness, interest in learning about experiments and experimental skills, clinical experimental thinking, and comprehensive experimental ability.

Background The testing for capability of some routine blood test parameters to reflect the biology of non-small cell lung carcinoma with different driver mutations is of great interest and practice significance. We aim to screen these variables and, if allowed, develop a novel predictive model based on results of these routine blood tests commonly performed in clinical practice to inform which can help doctors assess the patient’s genetic mutation status as early as possible before surgery. Methods For the exploration cohort, we included 1,595 patients who were diagnosed with non-small cell lung cancer (NSCLC) and genetically profiled by a next-generation sequencing panel in the First Affiliated Hospital of Guangzhou Medical University. The external validation cohort, which consists of 197 NSCLC cancer patients from Sun Yat-sen University Cancer Hospital, was subsequently established. Results We analyzed the association between 46 frequently tested laboratory variables and different genetic mutation types. KRAS mutation was found to be a unique subtype that exclusively correlated with several blood parameters in our study. Least absolute shrinkage and selection operator (LASSO) regression was performed, and the following parameters were found to be significantly associated with KRAS mutation: triglycerides [odds ratio (OR) =1.63], arterial oxygen partial pressure (OR =0.97), uric acid (OR =1.01), basophil count (OR =1.41), eosinophil count (OR =1.146), fibrinogen (OR =1.42), standard bicarbonate (OR =0.85), high-density lipoprotein cholesterol (OR =0.18), alpha-L-fucosidase (OR =1.07). The areas under the receiver-operator characteristic curve in the training set and the external validation set were 0.85 [95% confidence interval (CI): 0.81–0.88] and 0.81 (95% CI: 0.71–0.91), respectively. Conclusions We developed a non-invasive, more cost-effective predictive model of NSCLC based on routinely available variables, with practical predictive power. This model can be used as a practical screening tool to guide the use of more specialized and expensive molecular assays for KRAS mutation in NSCLC. However, further studies are warranted to investigate the mechanism underlying such association between KRAS mutations and the related parameters of blood tests.

Worldwide, lower respiratory tract infections (LRTI) are an important cause of hospitalization in children. Due to the relative limitations of traditional pathogen detection methods, new detection methods are needed. The purpose of this study was to evaluate the value of metagenomic next-generation sequencing (mNGS) of bronchoalveolar lavage fluid (BALF) samples for diagnosing children with LRTI based on the interpretation of sequencing results. A total of 211 children with LRTI admitted to the First Affiliated Hospital of Guangzhou Medical University from May 2019 to December 2020 were enrolled. The diagnostic performance of mNGS versus traditional methods for detecting pathogens was compared. The positive rate for the BALF mNGS analysis reached 95.48% (95% confidence interval [CI] 92.39% to 98.57%), which was superior to the culture method (44.07%, 95% CI 36.68% to 51.45%). For the detection of specific pathogens, mNGS showed similar diagnostic performance to PCR and antigen detection, except for Streptococcus pneumoniae, for which mNGS performed better than antigen detection. S. pneumoniae, cytomegalovirus and Candida albicans were the most common bacterial, viral and fungal pathogens. Common infections in children with LRTI were bacterial, viral and mixed bacterial-viral infections. Immunocompromised children with LRTI were highly susceptible to mixed and fungal infections. The initial diagnosis was modified based on mNGS in 29.6% (37/125) of patients. Receiver operating characteristic (ROC) curve analysis was performed to predict the relationship between inflammation indicators and the type of pathogen infection. BALF mNGS improves the sensitivity of pathogen detection and provides guidance in clinical practice for diagnosing LRTI in children.

The core of medical education is to continuously improve the quality of medical student training. The traditional teaching management mode has a single form and strong subjectivity, which can not reflect the comprehensive quality of standardized training trainees. In recent years, 360° feedback, introduced in the form of questionnaires, was used to obtain the information from various subjects who had a close working relationship with them, so as to better understand the training effect and teaching quality of students. Now, it has also been widely used in the assessment and evaluation of hospitals in China. How to establish a comprehensive and objective teaching management system and continuously enhance the quality of standardized training for students is the goal of the teaching management. In this paper, we retrospectively summarize the application of 360-degree evaluation methods in the teaching management of hospital standardized training students in the past 5 years, and attempt to explore the countermeasures that are more suitable for the standardized training of resident doctors in China, and then provide the constructive suggestions for future improvement.

OBJECTIVE:The aim of this research is to investigate the feasibility of folate receptor-positive circulating tumor cells (FR+CTCs) as a biomarker for the diagnosis of malignant pulmonary nodules and the correlation between clinicopathological factors and FR+CTC levels.METHODS:Patients initially diagnosed with one or more pulmonary nodules from a computed tomography scan were prospectively included. Three milliliters of peripheral blood was collected from each participant for FR+CTC analysis prior to surgery. Clinical and pathological parameters and FR+CTC levels were compared between patients with lung cancer and benign diseases.RESULTS:Six hundred fifty-three patients had lung cancer and the other 124 had benign lung diseases based on pathological examinations of the resected specimens. The median FR+CTC value of the lung cancer group was 12.0 (95% CI 9.6-16.2) FU/3 mL and that of the benign group was 7.2 (95% CI 5.78-11.2) FU/3 mL. The difference was statistically significant (P < 0.0001). In a receiver operating characteristic analysis to distinguish the two groups, the area under curve of FR+CTC was 0.7457 (95% CI 0.6893-0.8021; P < 0.0001) using a cutoff of 8.65 FU/3 mL. The sensitivity was 86.37%, and the specificity was 74.19%. Combined with conventional serum tumor biomarkers, the area under curve was 0.922 (0.499-0.963). The sensitivity was 92.20%, and the specificity was 83.05%. FR+CTC levels were related to tumor staging (P4 < 0.001), the degree of tumor invasion both in single (P = 0.011) and multiple lesions (P = 0.022), pathological subtypes (P = 0.013), and maximum tumor diameter (P = 0.014).CONCLUSIONS:FR+CTC is an effective and reliable biomarker for the diagnosis of lung cancer. Further, FR+CTC level is correlated with tumor staging, degree of invasion, pathological subtypes, and tumor size.

Human parainfluenza viruses (HPIVs) are a leading cause of acute respiratory tract infections (ARTIs). Non-pharmaceutical interventions (NPIs) were widely administered to combat the pandemic of the coronavirus disease 2019 (COVID-19). Respiratory specimens were obtained from 10,454 hospitalized children with ARTIs to detect HPIV. We investigated differences in epidemiological and clinical characteristics of HPIV infections before (2017-2019) and during the COVID-19 pandemic (2020-2022). HPIVs were detected in 392 (3.75%, 392/10,454) patients, of whom 70 (17.86%), 48 (12.24%), and 274 (69.90%) were positive for HPIV1, HPIV2, and HPIV3, respectively. Detection rates of HPIV3 were higher in 2020-2022 than in 2017-2019 (3.38% vs. 2.24%). The seasonal distribution of HPIV1 showed no difference, but HPIV3 peaked between September and December during the COVID-19 pandemic, which differed from previous epidemiological patterns. Compared to the period before the COVID-19 pandemic, there has been a noticeable decrease in the incidence of asthma, moist rales, and emesis in patients infected with HPIV1 and in asthma, expectoration, and severe pneumonia in patients infected with HPIV3 during 2020-2022. The detection rates of HPIV increased in Southern China during the COVID-19 outbreak, which underlines the importance of continuous surveillance of HPIV in the next epidemic season.

This study aimed to investigate the molecular epidemiology and antibiotic resistance of Haemophilus influenzae in Guangzhou, China. A total of 80 H. influenzae isolates were collected from the First Affiliated Hospital of Guangzhou Medical University from January 2020 to April 2021. Species identification, antimicrobial susceptibility, molecular capsular typing, multilocus sequence typing and the clinical characteristics analysis of patients were performed. For all recruited isolates, the majority of H. influenzae strains from patients with respiratory symptoms were found to be non-typeable H. influenzae (NTHi). The isolates were relative susceptible to third- and fourth-generation cephalosporins, quinolones and chloramphenicol, despite having a high ampicillin resistance rate (>70%). The genotyping results reveal a total of 36 sequence types (STs), with ST12 being the most prevalent ST. Remarkably, the 36 STs identified from 80 NTHi isolates within a short period of 15 months and in a single medical setting have revealed a high genetic diversity in NTHi isolates. In comparison, it is noteworthy that the most prevalent STs found in the present study have rarely been found to overlap with those from previous studies. This is the first study on the molecular epidemiology of NTHi isolates in Guangzhou, a city that is representative of southern China.

The spread of COVID‐19 worldwide caused by the severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has necessitated efficient, sensitive diagnostic methods to identify infected people. We report on the development of a rapid 15‐minute time‐resolved fluorescent (TRF) lateral flow immunochromatographic assay for the quantitative detection of the SARS‐CoV‐2 spike protein receptor‐binding domain (S1‐RBD).

Objective:To investigate the role of folic acid receptor circulating tumor cells in early diagnosis and prognosis of lung cancer patients.Methods:Folic acid receptor levels in inpatients and outpatients of thoracic surgery/respiratory department of our hospital from March to October 2020 were analyzed, and the relationship between the size of nodules, pathological stages and pathological types was analyzed.Results:Among patients with benign diseases, the sensitivity of FR+CTC was 73.9%; among newly diagnosed patients, the detection rate of FR+CTC was 76.0%, and the overall clinical compliance rate was 75.8%. There was a correlation between postoperation/overall and staging of FR+CTC level. The CTC level of stage Ⅳ patients was significantly higher than that of stage Ⅰ/Ⅱ/Ⅲ patients (P=0.0371). There were statistically significant differences in FR+CTC between infiltrating carcinoma and in situ carcinoma/microinfiltrating carcinoma. There was no clear correlation between FR+CTC level and pulmonary nodule/mass size.Conclusions:FR level plays an important role in the early diagnosis of lung cancer patients, which is correlated with tumor stage and invasion, and is a good prognostic indicator.

Mycobacterium abscessus is an emerging human pathogen leading to significant morbidity and even mortality, intrinsically resistant to almost all the antibiotics available and so can be a nightmare. Mechanisms of its intrinsic resistance remain not fully understood. Here, we selected and confirmed an M. abscessus transposon mutant that is hypersensitive to multiple drugs including rifampin, rifabutin, vancomycin, clofazimine, linezolid, imipenem, levofloxacin, cefoxitin, and clarithromycin. The gene MAB_0189c encoding a putative arabinosyltransferase C was found to be disrupted, using a newly developed highlyefficient strategy combining next-generation sequencing and multiple PCR. Furthermore, selectable marker-free deletion of MAB_0189c recapitulated the hypersensitive phenotype. Disruption of MAB_0189c resulted in an inability to synthesize lipoarabinomannan and markedly enhanced its cell envelope permeability. Complementing MAB_0189c or M. tuberculosis embC restored the resistance phenotype. Importantly, treatment of M. abscessus with ethambutol, a first-line antituberculosis drug targeting arabinosyltransferases of M. tuberculosis, largely sensitized M. abscessus to multiple antibiotics in vitro. We finally tested activities of six selected drugs using a murine model of sustained M. abscessus infection and found that linezolid, rifabutin, and imipenem were active against the MAB_0189c deletion strain. These results identified MAB_0189 as a crucial determinant of intrinsic resistance of M. abscessus, and optimizing inhibitors targeting MAB_0189 might be a strategy to disarm the intrinsic multiple antibiotic resistance of M. abscessus. IMPORTANCE Mycobacterium abscessus is intrinsically resistant to most antibiotics, and treatment of its infections is highly challenging. The mechanisms of its intrinsic resistance remain not fully understood. Here we found a transposon mutant hypersensitive to a variety of drugs and identified the transposon inserted into the MAB_0189c (orthologous embC coding arabinosyltransferase, EmbC) gene by using a newly developed rapid and efficient approach. We further verified that the MAB_0189c gene played a significant role in its intrinsic resistance by decreasing the cell envelope permeability through affecting the production of lipoarabinomannan in its cell envelope. Lastly, we found the arabinosyltransferases inhibitor, ethambutol, increased activities of nine selected drugs in vitro. Knockout of MAB_0189c made M. abscessus become susceptible to 3 drugs in mice. These findings indicated that potential powerful M. abscessus EmbC inhibitor might be used to reverse the intrinsic resistance of M. abscessus to multiple drugs.