[Analysis of the efficacy and safety of dual immunotherapy in patients with driver gene and programmed death ligand-1 double negative advanced non-small cell lung cancer].

Objective: To discuss the efficacy and safety of the dual immunotherapy of nivolumab plus ipilimumab in patients with advanced non-small cell lung cancer (NSCLC) who are double negative for driver gene and programmed death-ligand 1 (PD-L1) expression. Methods: We conducted a retrospective collection of clinical data for 61 patients with advanced NSCLC who were negative for both driver genes and PD-L1 and received dual immunotherapy with nivolumab plus ipilimumab at the First Affiliated Hospital of Guangzhou Medical University from January 2019 to June 2023. Based on treatment conditions, patients were divided into first-line and non-first-line dual immunotherapy groups. Patients were followed up monthly, with the follow-up period ending on October 1, 2023. The efficacy was evaluated using Solid Tumor Response Evaluation Criteria, and adverse reactions were assessed according to the Common Terminology Criteria for Adverse Events developed by the National Cancer Institute in the United States. Survival curves were plotted using the Kaplan-Meier method, and the log-rank test was used to compare the differences in progression-free survival (PFS) and overall survival (OS) between first-line and non-first-line dual immunotherapy patients. The influence factors of PFS were analyzed using a multivariate Cox proportional hazards regression model. Results: Among the 61 NSCLC patients, 49 were male (80.3%), with an age range of 23-88 years [(65.3±7.4) years]. There were 14 cases (23.0%) classified as stage ⅢC and 47 cases (77.0%) classified as stage Ⅳ according to TNM staging. Forty cases (65.6%) received non-first-line treatment. The objective response rate (ORR) was 24.6% (15/61), and the disease control rate (DCR) was 52.5% (32/61). All 61 patients were followed up, with a median follow-up time of 17.8 months. The median PFS was 6.0 months (95%CI: 5.5-6.4 months), and the median OS was 17.0 months (95%CI: 14.8-19.2 months). For patients receiving first-line dual immunotherapy, the median PFS was longer than for those receiving non-first-line dual immunotherapy [7.0 months (95%CI: 6.0-7.9 months) vs 4.0 months (95%CI: 3.3-4.6 months), P<0.001]; similarly, the median OS for patients receiving first-line dual immunotherapy was longer than for those receiving non-first-line dual immunotherapy [19.0 months (95%CI: 18.1-19.9 months) vs 13.0 months (95%CI: 10.8-15.1 months), P<0.001]. Multivariate Cox risk regression model analysis showed that distant tumor metastasis (HR=1.414, 95%CI: 1.253-1.725), non-first-line dual immunotherapy (HR=1.412, 95%CI: 1.184-1.652), and tumor mutation burden<10 mut/Mb (HR=1.328, 95%CI: 1.151-1.546) were risk factors for PFS, while non-squamous carcinoma (HR=0.917, 95%CI: 0.823-0.984) was a protective factor for PFS. Immune-related adverse reactions occurred in 41 cases (67.2%), including 21 cases (32.8%) of grade 3-4 adverse reactions. Eight cases (13.1%) discontinued treatment, and there were no deaths. Conclusions: Dual immunotherapy with nivolumab plus ipilimumab can be a treatment option for driver gene and PD-L1 double-negative advanced NSCLC. Distant tumor metastasis, non-first-line dual immunotherapy, and tumor mutation burden<10 mut/Mb are risk factors affecting patients' PFS, while non-squamous cell carcinoma is a protective factor affecting patients' PFS.

[New characteristics of COVID-19 caused by the Omicron variant in Guangzhou].

We investigated the types of novel coronavirus strains present during the Omicron epidemic from late 2022 to early 2023, COVID-19 co-infections with other pathogens, and clinical characteristics of patients with novel coronavirus infections. Adult patients hospitalized due to SARS CoV-2 infection in six hospitals in Guangzhou city were included in the study from November 2022 to February 2023. Clinical information was collected and analyzed, and bronchoalveolar lavage fluid was obtained for pathogen detection using a variety of techniques, including standard methods and mNGS, tNGS. The results showed that the main strain circulating in Guangzhou was Omicron BA.5.2, and the overall detection rate of potentially pathogenic pathogens combined with Omicron COVID-19 infection was 49.8%. In patients with severe COVID-19 infection, special attention should be paid to aspergillosis and combined Mycobacterium tuberculosis infection. In additon, Omicron strain infection could cause viral sepsis, which led to a worse prognosis for COVID-19 patients. Diabetic patients with SARS-CoV-2 infection did not benefit from glucocorticoid treatment, and caution was necessary when using glucocorticoids. These findings highlighted some new features of severe Omicron coronavirus infection that should be noted.

Preliminary Extracellular Vesicle Profiling in Drainage Fluid After Neck Dissection in OSCC.

Lymph node metastasis is related to poor prognosis in oral squamous cell carcinoma (OSCC), and few studies have explored the relevance of postoperative drainage fluid (PDF) in metastasis. Extracellular vesicles (EVs) are nanosized vesicles that can transfer oncogenic molecules to regulate tumorigenesis. However, the proteomic profile of postoperative drainage fluid-derived EVs (PDF-EVs) in OSCC has not been elucidated. Herein, we collected drainage fluid from OSCC patients after neck dissection to investigate the difference in PDF-EVs between patients with metastatic lymph nodes (the LN+ group) and nonmetastatic lymph nodes (the LN- group). The proteomic profile of PDF-EVs from the LN+ and LN- groups was compared using label-free liquid chromatography tandem-mass spectrometry-based protein quantification. The results revealed that PDF-EVs were mainly derived from epithelial cells and immune cells. A total of 2,134 proteins in the PDF-EVs were identified, and 313 were differentially expressed between the LN+ and LN- groups. Metabolic proteins, such as EHD2 and CAVIN1, were expressed at higher levels in the LN+ group than in the LN- group, and the levels of EHD2 and CAVIN1 in the postoperative drainage fluid were positively correlated with lymph node metastasis. Our study revealed previously undocumented postoperative drainage fluid-associated proteins in patients with metastatic OSCC, providing a starting point for understanding their role in metastatic and nonmetastatic OSCC.

[Summary of the 2021 Annual Academic Conference of the Chinese Burn Association].

Organized by the Chinese Medical Association and the Chinese Burn Association, hosted by the Hainan Medical Association and Hainan Provincial People's Hospital, and co-sponsored by the Chinese Journal of Burns (Chinese Journal of Burns and Wounds), Chinese Journal of Injury Repair and Wound Healing (Electronic Edition), and Burns & Trauma, the 2021 Annual Academic Conference of the Chinese Burn Association was held in beautiful Haikou from December 14 to 16, 2021. The conference continued to focus on the guiding principle of "One China, One Standard" and followed the tenet of "precise, homogeneous, and comfortable treatment" for burns. The conference received a total of 1 638 submissions, 296 electronic posters, 891 online and offline registered delegates, and nearly 750 offline attendees. The conference focused on the theme, adopting a variety of novel forms to discuss the key issues in burn field, including academician and committee director forum, doctor-nurse-rehabilitation therapist combined case competition, discipline development forum, and workshop, recording and broadcasting of surgical operations. The atmosphere was warm in the conference site.

Preparation of low-molecular-weight sodium alginate by ozonation.

Low-molecular-weight sodium alginate (LMWSA) has been reported to possess unique physicochemical properties and bioactivities. There is little information available about degradation of sodium alginate by ozonation. Effect of ozonation on molecular weight, molecular weight distribution, color change, M/G ratio, and chemical structure of sodium alginate was investigated. The molecular weight of sodium alginate decreased from 972.3 to 76.7 kDa in the 80-min period of ozonation at 25 °C. Two different degradation-rate constants were calculated. Molecular weight distribution of the LMWSA changed appreciably. Ozonation cannot lead to color change of LMWSA. The M/G ratio of LMWSA was not altered significantly, compared with that of the original alginate. The FT-IR and 13C NMR spectra indicated the chemical structure of LMWSA obtained by ozonation was not altered appreciably. New insight into the ozonation of alginate will be promisingly opened up. Ozonation of sodium alginate can be a alternative for production of LMWSA.

Cytomegalovirus infection as an underestimated trigger for checkpoint inhibitor-related pneumonitis in lung cancer: a retrospective study.

OBJECTIVES: Checkpoint inhibitor-related pneumonitis (CIP) is a rare but potentially fatal complication of immune checkpoint inhibitors (ICIs). At present, the mechanism of CIP is not completely clear. Cytomegalovirus (CMV) infection is widespread in the population. Chemotherapy and radiotherapy can lead to the reactivation of CMV. We aimed to investigate the association between CMV infection and CIP. MATERIALS AND METHODS: We retrospectively identified all lung cancer patients treated with ICIs at our institute from January 2016 to May 2020. The association between the development of CIP and CMV infection status was analyzed. RESULTS: Among 251 cases analyzed, 29 (11.6%) patients with CIP were identified, of whom 12 (4.78%) cases had grade 3-4 CIP. All 12 patients with grade 3-4 pneumonitis were CMV-IgG-positive, indicating a previous CMV infection. Except for one CMV-DNA-positive patient, the other patients were CMV-DNA-negative. All but one patient was CMV pp65 antigen-positive, indicating an early reactivation of the virus. The histological features of CMV pneumonia were not found in all available lung tissues, including lung transplantation pathology in one patient and lung biopsies in three patients. Except for one patient who received delayed antiviral therapy, the symptoms improved after glucocorticoid combined with antiviral therapy. CONCLUSIONS: The use of ICIs can restore the immune function and cause an immune response to CMV antigen while the infection is still latent. Our study suggests that CIP may be an immune reconstitution syndrome associated with CMV infection. CMV infection may represent a potentially important trigger for CIP. Patients with severe CIP should be vigilant against CMV infection. The early use of glucocorticoid combined with antiviral therapy is pivotal to good prognosis.

Commentary on a combined approach to the problem of developing biomarkers for the prediction of spontaneous preterm labor that leads to preterm birth.

INTRODUCTION: Globally, preterm birth has replaced congenital malformation as the major cause of perinatal mortality and morbidity. The reduced rate of congenital malformation was not achieved through a single biophysical or biochemical marker at a specific gestational age, but rather through a combination of clinical, biophysical and biochemical markers at different gestational ages. Since the aetiology of spontaneous preterm birth is also multifactorial, it is unlikely that a single biomarker test, at a specific gestational age will emerge as the definitive predictive test. METHODS: The Biomarkers Group of PREBIC, comprising clinicians, basic scientists and other experts in the field, with a particular interest in preterm birth have produced this commentary with short, medium and long-term aims: i) to alert clinicians to the advances that are being made in the prediction of spontaneous preterm birth; ii) to encourage clinicians and scientists to continue their efforts in this field, and not to be disheartened or nihilistic because of a perceived lack of progress and iii) to enable development of novel interventions that can reduce the mortality and morbidity associated with preterm birth. RESULTS: Using language that we hope is clear to practising clinicians, we have identified 11 Sections in which there exists the potential, feasibility and capability of technologies for candidate biomarkers in the prediction of spontaneous preterm birth and how current limitations to this research might be circumvented. DISCUSSION: The combination of biophysical, biochemical, immunological, microbiological, fetal cell, exosomal, or cell free RNA at different gestational ages, integrated as part of a multivariable predictor model may be necessary to advance our attempts to predict sPTL and PTB. This will require systems biological data using "omics" data and artificial intelligence/machine learning to manage the data appropriately. The ultimate goal is to reduce the mortality and morbidity associated with preterm birth.

Characteristics and roles of severe acute respiratory syndrome coronavirus 2-specific antibodies in patients with different severities of coronavirus 19.

The diagnosis of coronavirus 19 (COVID-19) relies mainly upon viral nucleic acid detection, but false negatives can lead to missed diagnosis and misdiagnosis; severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-specific antibody detection is convenient, safe and highly sensitive. Immunoglobulin (Ig)M and IgG are commonly used to serologically diagnose COVID-19; however, the role of IgA is not well known. We aimed to quantify the levels of SARS-CoV-2-specific IgM, IgA and IgG antibodies, identify changes in them based on COVID-19 severity, and establish the significance of combined antibody detection. COVID-19 patients, divided into a severe and critical group and a moderate group, and non-COVID-19 patients with respiratory disease were included in this study. A chemiluminescence method was used to detect the levels of SARS-CoV-2-specific IgM, IgA and IgG in the blood samples from the three groups. Epidemiological characteristics, symptoms, blood test results and other data were recorded for all patients. Compared to the traditional IgM-IgG combined antibodies, IgA-IgG combined antibodies are more effective for diagnosing COVID-19. During the disease process, IgA appeared first and disappeared last. All three antibodies had significantly higher levels in COVID-19 patients than in non-COVID-19 patients. IgA and IgG were also higher for severe and critical disease than for moderate disease. All antibodies were at or near low levels at the time of tracheal extubation in critical patients. Detection of SARS-CoV-2-specific combined IgA-IgG antibodies is advantageous in diagnosing COVID-19. IgA detection is suitable during early and late stages of the disease. IgA and IgG levels correspond to disease severity.

[Pulmonary rehabilitation guidelines in the principle of 4S for patients infected with 2019 novel coronavirus (2019-nCoV)].

A recent epidemic of pneumonia cases in Wuhan China was caused by a novel coronavirus with strong infectivity, the 2019 novel coronavirus (2019-nCoV). The article provides the pulmonary rehabilitation (PR) methods in the principle of 4S (simple, safe, satisfy, save) for patients with pneumonia caused by the novel coronavirus, shows how to establish a ventilative and convectional PR environment to prevent the spread of virus through droplets, how to guide the patients to carry out PR, how to carry out respiratory muscle training, effective cough, expectoration, sneeze, general exercise, digestive function rehabilitation and psychological rehabilitation, and how to clean and disinfect the PR environment.

The relationship between atherosclerosis and bone mineral density in patients with type 2 diabetes depends on vascular calcifications and sex.

It is unknown whether a relationship exists between bone mineral density (BMD) and atherosclerosis with or without vascular calcification. In our study, a negative correlation between carotid atherosclerosis and BMD was found in female T2DM patients with vascular calcification, but not in those without calcification and males. INTRODUCTION: Atherosclerosis is considered associated with low bone mineral density (BMD). However, most previous studies focus on patients with arterial atherosclerosis with vascular calcification. It is still unknown whether a relationship exists between atherosclerosis and BMD in patients without calcification. It is also unknown if sex plays a role in this relationship. METHODS: We performed a retrospective cross-sectional study, which included 1459 type 2 diabetes mellitus (T2DM) patients (648 males ≥ 50 years old, and 811 postmenopausal females). They were assigned to three groups: group 1 (patients without carotid plaques and without carotid calcification), group 2 (patients with carotid plaques but without carotid calcification), and group 3 (patients with carotid plaques and with carotid calcification). Clinical characteristics and BMD were compared. The relationship between atherosclerosis and BMD was determined by binary logistic regression analysis. Statistical analysis was performed using SPSS 25.0. RESULTS: Significant differences were only observed in women. The percentage of osteoporosis was higher in group 3 (43.64%) than in groups 1 (34.82%) and 2 (32.14%) (P = 0.016). Low BMD was found in the lumbar (P = 0.032), hip (P < 0.001), and femoral neck (P < 0.001). The odds ratio for osteoporosis increased significantly in a score-dependent manner in postmenopausal female patients with calcified atherosclerosis, but not in uncalcified patients. In men, no differences or relationships were identified. CONCLUSION: A negative correlation between carotid atherosclerosis and BMD was found in female T2DM patients with vascular calcification, but not in those without calcification. A similar relationship was not observed in male patients with or without calcification. Thus, the relationship between atherosclerosis and bone mineral density in patients with type 2 diabetes depends on vascular calcifications and sex.

[Summary of the 2019 Academic Annual Meeting of the Chinese Burn Association].

The 2019 Academic Annual Meeting of the Chinese Burn Association, sponsored by the Chinese Medical Association and the Chinese Burn Association, was successfully held in Zhuhai, Guangdong province, from November 6th to 9th, 2019. The theme of this conference was " One China, One Standard--Data Standardization and Construction of National Burn Data Platform" . A total of 2 305 submissions and 1 749 e-posters were received, and 1 097 registered representatives, nearly 2 000 representatives from 9 countries and regions attended the meeting. Focusing on the theme of this conference, a variety of novel forms were adopted such as teaching contest of young surgeons, multi-disciplinary discussion, workshop, and surgery live broadcast on hot issues in key areas of burns. Besides, with the focus on humanistic care and innovation, a multi-disciplinary discussion was warmly conducted. The 2020 academic annual conference is scheduled to be held in Nanchang, China.

The impact of surgical timing on neurological outcomes and survival in patients with complete paralysis caused by spinal tumours: evaluation of surgery on patients with complete paralysis due to neoplastic epidural spinal cord compression.

AIMS: The aim of this study was to explore the prognostic factors for postoperative neurological recovery and survival in patients with complete paralysis due to neoplastic epidural spinal cord compression. PATIENTS AND METHODS: The medical records of 135 patients with complete paralysis due to neoplastic cord compression were retrospectively reviewed. Potential factors including the timing of surgery, muscular tone, and tumour characteristics were analyzed in relation to neurological recovery using logistical regression analysis. The association between neurological recovery and survival was analyzed using a Cox model. A nomogram was formulated to predict recovery. RESULTS: A total of 52 patients (38.5%) achieved American Spinal Injury Association Impairment Scale (AIS) D or E recovery postoperatively. The timing of surgery (p = 0.003) was found to be significant in univariate analysis. In multivariate analysis, surgery within one week was associated with better neurological recovery than surgery within three weeks (p = 0.002), with a trend towards being associated with a better neurological recovery than surgery within one to two weeks (p = 0.597) and two to three weeks (p = 0.055). Age (p = 0.039) and muscle tone (p = 0.018) were also significant predictors. In Cox regression analysis, good neurological recovery (p = 0.004), benign tumours (p = 0.039), and primary tumours (p = 0.005) were associated with longer survival. Calibration graphs showed that the nomogram did well with an ideal model. The bootstrap-corrected C-index for neurological recovery was 0.72. CONCLUSION: In patients with complete paralysis due to neoplastic spinal cord compression, whose treatment is delayed for more than 48 hours from the onset of symptoms, surgery within one week is still beneficial. Surgery undertaken at this time may still offer neurological recovery and longer survival. The identification of the association between these factors and neurological recovery may help guide treatment for these patients. Cite this article: Bone Joint J 2019;101-B:872-879.

Detection of novel mutations associated with independent resistance and cross-resistance to isoniazid and prothionamide in Mycobacterium tuberculosis clinical isolates.

OBJECTIVES: Prothionamide, a structural analogue of isoniazid, is used mainly for treating multidrug-resistant tuberculosis (MDR-TB). Both drugs have a common target InhA, so prothionamide can be ineffective against isoniazid-resistant (INHR) Mycobacterium tuberculosis. We aimed to investigate the prevalence of mutations in katG, ethA, ndh, ethR, mshA, inhA and/or its promoter associated with independent resistance and cross-resistance to INHR and/or prothionamide-resistant (PTOR) M. tuberculosis isolates. METHODS: We sequenced the above genes in 206 M. tuberculosis isolates with susceptibility testing against ten drugs. RESULTS: Of the 173 INHR PTOR isolates, 170 (98.3%) harboured mutations in katG, 111 (64.2%) in ethA, 58 (33.5%) in inhA or its promoter, 5 (2.9%) in ndh, 3 (1.7 %) in ethR and 2 (1.2%) in mshA. Among the 18 INHR PTOS isolates, mutations in katG were found in all of them; one had a mutation in the inhA promoter and another in ndh. Of the five INHS PTOR isolates, four showed mutations in ethA and two in the inhA promoter. Notably, 55 novel non-synonymous mutations were found in them and 20.2% of the PTORM. tuberculosis isolates harboured no known mutations. CONCLUSIONS: This is the first report to investigate cross-resistance between INHR and/or PTOR isolates. Among INHR (94.4% MDR-TB) M. tuberculosis isolates, the high diversity of mutations for independent resistance and cross-resistance with prothionamide highlight the importance of both phenotypic susceptibility and genotypic diagnosis when using it to treat patients with INHR-TB. The high proportion (one-fifth) of PTORM. tuberculosis isolates showed no known mutation related to PTOR genes, so uncovered resistance mechanism(s) of prothionamide exist.

[Summary of the 2018 Academic Annual Meeting of the Chinese Burn Association].

The 2018 Academic Annual Meeting of the Chinese Burn Association, sponsored by the Chinese Medical Association and the Chinese Burn Association, was successfully held in Fuzhou, Fujian Province, from October 24th to 27th. The theme of this conference is " One China, One Standard". A total of 1, 798 submissions were received, and 1, 060 registered representatives, more than 2, 000 representatives from 9 countries and regions attended the meeting. Focusing on the theme of " One China, One Standard" , the conference adopted a variety of innovative forms such as academic debate, live surgery, BBS on both sides of the straits, award selection, and so on to provide participants with multiple ways for exchange on the professional hot issues in the key areas of burns. The atmosphere of the conference was warm. The 2019 annual academic conference is scheduled to be held in Zhuhai, China.

Proteobacteria community compositions correlate with bronchiectasis severity.

BACKGROUND: Proteobacteria contributes to airway inflammation and poor clinical outcomes in bronchiectasis. OBJECTIVE: To compare sputum Proteobacteria compositions according to bronchiectasis severity. METHODS: Sputum samples collected from 106 patients with stable bronchiectasis and 17 healthy subjects were split for 16srRNA sequencing and biomarker measurement. Pairwise changes in Proteobacteria compositions among 22 of 106 patients during stability, exacerbations and convalescence were compared. Patients were stratified based on the Bronchiectasis Severity Index (BSI). RESULTS: Respectively 44, 34 and 28 patients had mild, moderate and severe bronchiectasis. A higher BSI was associated with a greater relative abundance of Proteobacteria and lower Shannon-Wiener diversity index, Simpson diversity index and bacterial richness. Similar findings applied at genera levels. Proteobacteria and Pseudomonas were the major phylum and genus, respectively, contributing to community similarity in moderate-to-severe bronchiectasis. These significant correlations were not observed in those in whom Pseudomonas aeruginosa was not isolated. Proteobacteria abundance correlated with lung function, but not sputum inflammatory biomarkers in severe bronchiectasis. Proteobacteria compositions in severe bronchiectasis were less likely to change significantly during exacerbations and convalescence. CONCLUSION: Proteobacteria compositions (particularly culturable Pseudomonas abundance) were correlated with bronchiectasis severity. Proteobacteria and Pseudomonas contributed most to community similarity in patients with a higher BSI, indicating microbial targets for interventions in severe bronchiectasis.

Universal newborn screening: A roadmap for action.

Newborn screening (NBS) prevents morbidity and mortality by screening babies for selected disorders in the first days of life so that early diagnosis and treatment can be initiated. Congenital disorders impact an estimated 8 million or 6% of annual births worldwide, and of the top five that contribute 25% to the global burden of these disorders, three can be identified and managed by NBS. There are determined pockets of activity in Latin America, Sub-Saharan Africa, and the Asia Pacific region, where partnerships among government, non-governmental organizations, academia, the private sector and civil society are developing novel NBS programs that are both saving lives and preventing disability in those who survive.

[The composition and antimicrobial resistance of isolates from lower respiratory tract and blood in hospitalized patients in respiratory ward: a multicenter national study in China].

Objective: To investigate the species and antimicrobial resistance of bacterial pathogens isolated from hospitalized patients in respiratory ward in China. Methods: This was a multicenter retrospective study based on a national epidemiological network called China Antimicrobial Resistance Surveillance System (CARSS). The non-repetitive strains isolated from lower respiratory tract and blood samples in 91 hospitals from seven geographic regions of CARSS were reviewed. The distribution of specimen type, hospital level (secondary and tertiary hospital), patient age group [geriatric (>65 years old), adult (15 to 65 years old), pediatric (28 days to 14 years old ) and newborn group (≤28 days)] and ward type (respiratory intensive care unit and general respiratory ward) were analyzed for MRSA, PRSP, CREC, CRKP, CRPA, CRAB, ESBL-EC and ESBL-KP. The categorical variables were analyzed by chi-square test using SPSS 16.0 statistical software. P<0.05 was regarded as statistically significant. Results: A total of 50 417 non-repetitive isolates [42 751 isolates from lower respiratory tract (LRT), 2 649 isolates from blood and 5 017 isolates from other samples (urine and secretions)] from 48 752 inpatients (without illness type information) were enrolled in the study. 90.2% (45 491/50 417) isolates were obtained from 63 tertiary hospitals. According to patients' age, all cases were divided into 4 groups, i. e. geriatric(46.0%, 23 177/50 417), adult(29.9%, 15 092/50 417), pediatric(24.0%, 12 112/50 417) and newborn group(0.0%, 36/50 417). All isolates were obtained from respiratory intensive care unit (6.2%, 3 129/50 417) or general respiratory wards (93.8%, 47 288/50 417). The majority of bacterial pathogens were isolated from lower respiratory and blood culture samples, which accounted for 90.0% of all the samples (45 400/50 417). Sputum accounted for 81.6% (41 131/50 417) of samples, and the leading 4 isolates were K. pneumonia (18.9%, 7 784/41 131), P. aeruginosa (13.6%, 5 580/41 131), A. baumanni (11.3%, 4 644/41 131) and S. pneumonia (11.1%, 4 564/41 131). Blood samples accounted for 5.3% (2 649/50 417) of the samples, with the leading 4 bacteria being coagulase-negative staphylococcus (42.0%, 1 112/2 649), E. coli (18.3%, 484/2 649), K. pneumonia (7.4%, 194/2 649) and S. aureus (4.9%, 131/2 649). The species distribution of pathogens isolated from bronchoalveolar lavage fluid (BALF), which accounted for 3.2% (1 620/50 417) of the samples, was similar to that of sputum, and the leading 4 bacteria were P. aeruginosa (22.0%, 360/1 620), K. pneumonia (14.8%, 239/1 620), A. baumanni (11.9%, 193/1 620) and S. pneumonia (9.6%, 155/1 620). The prevalence of CRKP, CRPA and CRAB in tertiary hospitals [5.2% (384/7 439), 23.8% (1 260/5 304) and 53.5% (2 259/4 224), respectively] was significantly higher than that in secondary hospitals [2.5% (24/973), 12.8% (101/787) and 33.9% (109/322), respectively] (all P<0.01). In comparison, the prevalence of ESBL-EC in secondary hospitals (63.9%, 145/227) was higher than that in tertiary ones (55.0%, 1 141/2 074) (P=0.011). The prevalence of ESBL-EC and ESBL-KP in pediatric group [68.2% (283/415) and 55.3% (183/331), respectively] was higher than that in geriatric group [54.2% (684/1 263) and 27.1% (625/2 303), respectively] and adult group [51.1% (317/620) and 15.1% (272/1 804), respectively] (all P<0.001). Conclusions: In China, the predominant bacterial pathogens in the respiratory wards were Enterobacteriaceae and non-fermentative bacteria. High prevalence of ESBL-EC and ESBL-KP isolated from lower repiratory tract was revealed in primary hospitals and pediatric patients.