Loss and gain of ceftazidime-avibactam susceptibility in a non-carbapenemase-producing K1-ST23 hypervirulent Klebsiella pneumoniae

OBJECTIVES

This study aimed at revealing the underlying mechanisms of the loss and gain of ceftazidime-avibactam susceptibility in a non-carbapenemase-producing hypervirulent Klebsiella pneumoniae (hvKp).

METHODS

Here we longitudinally recovered 3 non-carbapenemase-producing K1-ST23 hvKp strains at a one-month interval (KP29105, KP29499 and KP30086) from an elderly male. Antimicrobial susceptibility testing, whole genome sequencing, transcriptomic sequencing, gene cloning, plasmid conjugation, quantitative real-time PCR (qRT-PCR), and SDS-PAGE (sodium dodecyl sulfate-polyacrylamide gel electrophoresis) were conducted.

RESULTS

Among the 3 hvKp strains, KP29105 was resistant to the third- and fourth-generation cephalosporins, KP29499 acquired resistance to both ceftazidime-avibactam and carbapenems, while KP30086 restored its susceptibility to ceftazidime-avibactam, imipenem and meropenem but retained low-level resistance to ertapenem. KP29105 and KP29499 carried plasmid-encoded genes blaCTX-M-15 and blaCTX-M-71, respectively, but KP30086 lost both. Cloning of gene blaCTX-M-71 and conjugation experiment of blaCTX-M-71-carrying plasmid showed that the transformant and transconjugant were susceptible to ceftazidime-avibactam but had a more than 8-fold increase in MICs. Supplementation with an outer membrane permeabilizer could reduce the MIC of ceftazidime-avibactam by 32 folds, indicating that porins play a key role in ceftazidime-avibactam resistance. The OmpK35 of the 3 isolates was not expressed, and the OmpK36 of KP29499 and KP30086 had a novel amino acid substitution (L359R). SDS-PAGE and qRT-PCR showed that the expression of porin OmpK36 of KP29499 and KP30086 was significantly down-regulated compared with KP29105.

CONCLUSIONS

In summary, we reported the rare ceftazidime-avibactam resistance in a non-carbapenemase-producing hvKp strain. Resistance plasmid carrying blaCTX-M-71 and mutated OmpK36 had a synergetic effect on the resistance.

[Research progress on the impact of diet on the early-onset colorectal cancer]

The incidence of early-onset colorectal cancer has been gradually increasing in recent years. Studies have shown that early-onset CRC is closely related to modifiable risk factors such as diet, but there is still a lack of consistent conclusions and a systematic review of relevant research results. In this review, we comprehensively summarized the association between diet and the early-onset CRC, clarified the association and relative risk between different dietary patterns, common food types and nutrients and the occurrence of early-onset CRC, and elaborated the underlying physiological mechanisms. Enhancing the understanding of dietary risk factors, which are modifiable exogenous risk factors, is expected to serve as a reference for the formulation of primary prevention strategies for early-onset CRC.

[Interpretation of specification for service of cancer screening for workers]

As the backbone force of China's social and economic construction, the health status of workers is closely related to the nation's productivity and social development. Currently, cancers have become one of the major diseases threatening the health of workers. However, there are still many shortcomings in the cancer screening services for the workers. To standardize cancer screening services for workers, ensure the quality of screening services, and improve the overall screening effectiveness, 19 institutions, including Peking Union Medical College Hospital of the Chinese Academy of Medical Sciences, have jointly formulated the Group Standard "Specification for service of cancer screening for workers (T/CHAA 023-2023)". This standard follows the principles of "legality, scientific rigor, advancement, and feasibility" and combines the frontier scientific advances in cancer screening. It clarifies the relevant requirements for service principles, service design, service delivery, service management, service evaluation, and improving worker cancer screening. Implementing this group standard will help connect the common screening needs of workers, employers, and cancer screening service providers, standardize the screening process, improve screening quality, and ultimately increase the early diagnosis rate and survival rate of cancer patients. Consequently, this group standard will help safeguard workers' health rights and interests, ensure the labor force resources, promote the comprehensive coordinated and sustainable development of society, and contribute to realizing the "Healthy China 2030" strategic policy.

Quality control of postoperative radiotherapy for non-small cell lung cancer: A study of mediastinal shift

PURPOSE

This study aimed to assess the shifting patterns of the mediastinum, including the target volume and the isocenter point during the postoperative radiotherapy (PORT) process of non-small cell lung cancer (NSCLC), and to observe the occurrence of radiation injury. Additionally, we investigated the significance of mid-term assessment during the implementation of the PORT process.

MATERIAL AND METHODS

We established coordinate axes based on bone anatomy and measured the mediastinum's three-dimensional direction and the shift of the isocenter point's shift in the PORT process. Statistical analysis was performed using Wilcoxon, Kruskal-Wallis, and the Chi-square test. P<0.05 was considered statistically significant.

RESULTS

In this study, the analysis of patients revealed that the shift of anterior and posterior mediastinum (X), left and right mediastinum (Y), upper and lower mediastinum (Z), anterior and posterior isocenter point (Xi), and the left and right isocenter points (Yi) in the PORT process were 0.04-0.53, 0.00-0.84, 0.00-1.27, 0.01-0.86, and 0.00-0.66cm, respectively. The shift distance of the mediastinum was Z>Y>X, and the shift distance of the isocenter point was Xi>Yi. According to the ROC curve, the cut-off values were 0.263, 0.352, 0.405, 0.238, and 0.258, respectively, which were more significant than the cut-off values in 25 cases (25%), 30 cases (30%), 30 cases (30%), 17 cases (17%), and 15 cases (15%). In addition, there was a significant difference in the shift of the mediastinum and the isocenter point (all P=0.00). Kruskal-Wallis test showed no statistically significant difference between mediastinal shift and resection site in X, Y, and Z directions (P=0.355, P=0.239, P=0.256), surgical method (P=0.241, P=0.110, P=0.064). There was no significant difference in the incidence of RE and RP in PORT patients (P>0.05). No III-IV RP occurred. However, the incidence of ≥ grade III RE in the modified plan cases after M-S was significantly lower than in the original PORT patients, 0% and 7%, respectively (P=0.000).

CONCLUSION

In conclusion, this study provides evidence that mediastinal shift is a potential complication during the PORT process for patients with N2 stage or R1-2 resection following radical resection of NSCLC. This shift affects about 20-30% of patients, manifesting as actual radiation damage to normal tissue and reducing the local control rate. Therefore, mid-term repositioning of the PORT and revision of the target volume and radiation therapy plan can aid in maintaining QA and QC during the treatment of NSCLC patients and may result in improved patient outcomes.

The impacts of exposure to risk factors during youth on the increasing global trend of early-onset pancreatic cancer

OBJECTIVES

An increasing trend of pancreatic cancer in young adults has emerged in some countries. This study aimed to investigate global trends of pancreatic cancer in young adults and explore the impact of exposure to risk factors on pancreatic cancer incidence during youth.

METHODS

Global and national data on pancreatic cancer incidence, disability-adjusted life-years, attributive mortality, and summary exposure values of risk factors were retrieved from the Global Burden of Disease 2019. The average annual percent change (AAPC) of incidence and mortality was calculated. Additionally, generalized additive models were applied to explore the non-linear associations between the levels and changes in the Human Development Index and AAPC.

RESULTS

Global pancreatic cancer incidence increased during various periods from 1990 to 2019, particularly in adults aged <45 years from 2010 to 2019, at an average annual increase rate of 0.7% (95% confidence interval: 0.4-1.0%). The AAPC of early-onset pancreatic cancer incidence from 2010 to 2019 was negatively correlated with Human Development Index levels in both 2010 and 2019 but positively correlated with Human Development Index acceleration. Significant increases in early-onset pancreatic cancer incidence were observed over this period in 32 of 88 countries, primarily in South America, North America, Oceania, and Africa. Early-onset pancreatic cancer mortality attributed to high body mass index and fasting plasma glucose increased, while that attributed to tobacco use declined.

CONCLUSIONS

An increasing trend has emerged in the global incidence and burden of early-onset pancreatic cancer over the last few decades. This rise may partly be attributed to global epidemics of high body mass index and fasting plasma glucose.

Comparison of influenza- and COVID-19-associated pulmonary aspergillosis in China

PURPOSE

We conducted a monocentric retrospective study using the latest definitions to compare the demographic, clinical, and biological characteristics of influenza-associated pulmonary aspergillosis (IAPA) and COVID-19-associated pulmonary aspergillosis (CAPA).

METHODS

The study retrospectively enrolled 180 patients, including 70 influenza/IPA patients (with positive influenza A/B and Aspergillus) and 110 COVID-19/IPA patients (with positive SARS-CoV-2 and Aspergillus). Among them, 42 (60%) and 30 (27.3%) patients fulfilled the definitions of IAPA and CAPA, respectively.

RESULTS

The CAPA patients had significantly higher in-hospital mortality (13/31, 41.9%) than IAPA patients (8/42, 19%) with a P-value of 0.033. Kaplan-Meier survival curve also showed significantly higher 30-day mortality for CAPA patients (P = 0.025). Additionally, the CAPA patients were older, though insignificantly, than IAPA patients (70 (60-80) vs. 62 (52-72), P = 0.075). A lower percentage of chronic pulmonary disease (12.9 vs. 40.5%, P = 0.01) but higher corticosteroids use 7 days before and after ICU admission (22.6% vs. 0%, P = 0.002) were found in CAPA patients. Notably, there were no significant differences in the percentage of ICU admission or ICU mortality between the two groups. In addition, the time from observation to Aspergillus diagnosis was significantly longer in CAPA patients than in IAPA patients (7 (2-13) vs. 0 (0-4.5), P = 0.048).

CONCLUSION

Patients infected with SARS-CoV-2 and Aspergillus during the concentrated outbreak of COVID-19 in China had generally higher in-hospital mortality but a lower percentage of chronic pulmonary disease than those infected with influenza and Aspergillus. For influenza-infected patients who require hospitalization, close attention should be paid to the risk of invasive aspergillosis upfront.

Coexistence of virulent and multidrug-resistant plasmids in an uropathogenic Escherichia coli

OBJECTIVES

The emergence of pathogens co-harbouring multiple mobile resistance and virulence elements is of great concern in clinical settings. Herein, we report an O101: H10-ST167 Escherichia coli Hu106 strain isolated from the urinary tract of a female in China.

METHODS

Antibiotic susceptibility testing was used to present the antimicrobial resistance spectrum. Whole-genome sequencing (WGS) and bioinformatic analysis were used to clarify the virulent and resistance mechanisms. Furthermore, the virulence of this strain was tested by the Greater wax moth larvae and siderophore production experiment.

RESULTS

The strain E. coli Hu106 was resistant to almost all antimicrobials tested, and only susceptible to aztreonam, amikacin, and tigecycline. WGS analysis revealed that the strain Hu106 co-harboured blaNDM-9 and mcr-1 on p2-Hu106, belonging to IncHI2/IncHI2A (256,000 bp). The co-existence of both resistance genes, blaNDM-9 and mcr-1, on the plasmid p2-Hu106 was mainly acquired by transposition recombination of mobile antibiotic elements mediated by IS26 and/or IS1 on IncHI2/IncHI2A type plasmid. In addition, the virulence clusters aerobactin (iutA-iucABCD) and salmochelin (iroBCDEN) were identified on an IncFIB/IncFIC(IncFII) type plasmid p1-Hu106, flanked by small mobile elements such as IS1A, ISkpn28, and IS3, respectively. After performing genomic comparison of p1-Hu106 with the WGS in NCBI, we identified that the virulent plasmid p1-Hu106-like could spread in different clones of E. coli and Klebsiella pneumoniae, revealing its underlying dissemination mechanism between Enterobacterales. Furthermore, the strain caused a decreased survival rate of larvae and produced high siderophore units (62.33%), similar to hypervirulent K. pneumoniae NTUH-K2044.

CONCLUSIONS

The strains co-carrying the multidrug-resistant plasmid p2-Hu106 and virulent plasmid p1-Hu106 should be closely monitored to prevent its further spreading.

[Research on the framework of biosafety standards for pathogenic microbial laboratories]

Developing and implementing biosafety standards for pathogenic microbiology laboratories is essential to achieving scientific, efficient, and standardized management and operation. This article analyzes the current standardization construction in biosafety in pathogenic microbiology laboratories domestically and internationally. It proposes a framework for the biosafety standard system of pathogenic microbiology laboratories, which mainly includes four parts: basic standards, management standards, technical standards, and industry applications. It provides a reference for the standardization work of pathogenic microbiology laboratories and helps to standardize the biosafety industry in China.

Preoperative diagnostic value of coronary CT angiography in acute Stanford type A aortic dissection involving the coronary arteries

AIM

To assess the diagnostic value of coronary computed tomography angiography (CCTA) in acute type A aortic dissection (ATAAD) with coronary artery involvement and to evaluate whether CCTA could provide potentially useful information for selecting the surgical method.

MATERIALS AND METHODS

Patients with ATAAD treated from January 2019 to December 2020 were reviewed retrospectively. Involvement of the coronary arteries based on CCTA findings were grouped into three major types and five subtypes. Interobserver and intraobserver diagnostic agreement for five subtypes were determined. The patients were divided into the coronary artery bypass grafting (CABG) and non-CABG groups, and the proportions of the five subtypes between the two groups were compared.

RESULTS

A total of 95 patients were enrolled in this study. Interobserver and intraobserver diagnostic agreement were both substantial in the left and right coronary arteries. Overall, the proportions of the five subtypes of coronary artery involvement were significantly different between the two groups (p<0.001). The proportion of Type A was elevated in the non-CABG group compared with the CABG group (22.6% versus 71.9%); by contrast, the proportions of Type B1 (35.5% versus 14.1%), Type B2 (19.4% versus 10.9%), Type C1 (6.5% versus 0%), and Type C2 (16.1% versus 3.1%) were elevated in the CABG group.

CONCLUSION

CCTA is reliable in evaluating coronary artery involvement by ATAAD. The present retrospective study indicated that CABG may be considered if the intimal flap disrupts the coronary orifice and causes luminal stenosis >50%, particularly Type B, or if an intimal tear occurs in the coronary orifice (Type C), which deserve further validation through prospective studies.

[Participation rate and detection of colorectal neoplasms based on multi-round fecal immunochemical testing for colorectal cancer screening in the Chinese population]

Objective: To evaluate the participation rate and detection of colorectal neoplasms based on annual fecal immunochemical testing (FIT) for three consecutive years in a population-based colorectal cancer screening program in China. Methods: Based on a population-based colorectal cancer screening program conducted from May 2018 to May 2021 in 6 centers in China, 7 793 eligible participants aged 50-74 were included and offered free FIT and colonoscopy (for those who were FIT-positive on initial screening). At baseline, all participants were invited to receive FIT. In subsequent screening rounds, only FIT-positive participants who did not undergo colonoscopy or FIT-negative participants were invited to have repeated FIT screening. FIT-positive participants were recommended to undertake colonoscopy and pathological examination (if abnormalities were found during colonoscopy). An overall of three rounds of annual FIT screening were conducted. The primary outcomes of the study were the participation rate of FIT screening, the compliance rate of colonoscopy for FIT-positive participants, and the detection rate of colorectal neoplasms. Results: Among the 7 793 participants included in this study, 3 310 (42.5%) were male, with age of (60.50±6.49) years. The overall participation rates for the first, second and third round of FIT screening were 94.0%(7 327/7 793), 86.8% (6 048/6 968) and 91.3% (6 113/6 693), respectively. Overall, 7 742 out of 7 793 participants (99.3%) attended at least one round of screening, and 5 163 out of 7 793 participants (66.3%) attended all three rounds of screening. The positivity rate was significantly higher in the first (14.6%, 1 071/7 327) round compared with the second (5.6%, 3 41/6 048) and third (5.5%, 3 39/6 113) screening rounds (P<0.001). The overall compliance rates of colonoscopy examination among FIT-positive subjects were over 70% in three rounds, which were 76.3% (817/1 071), 75.7% (258/341) and 71.7% (243/339), respectively. In a multivariate logistic regression model considering factors including sex, education background, smoking, alcohol drinking, previous colonoscopy examination, colonic polyp history and family history of colorectal cancer among first-degree relatives, gender and smoking status were related factors affecting the participation rate of FIT screening, with higher rate in males and non-smokers. In addition, logistic regression analysis also found that age was negatively correlated with the compliance rate of colonoscopy in FIT positive patients. The detection rate of advanced tumors (colorectal cancer + advanced adenoma) declined from the first round to subsequent rounds [1st round: 1.15% (90/7 793); 2nd round: 0.57% (40/6 968); and 3rd round: 0.58% (39/6 693)], however, the positive predictive value for advanced neoplasms increased round by round, and was 11.02% in the first screening round, 15.50% in the second screening round, and 16.05 % in the third screening round. In each screening round, the detection rate for advanced neoplasms was higher in men than that in women, and increased with age. Conclusions: Annual repeated FIT screening has high acceptance and satisfying detection rates in the Chinese population. To optimize and improve the effectiveness of colorectal cancer screening, multi-round repeated FIT screening should be implemented while ensuring high participation rates.

In vitro activity of cefiderocol, a siderophore cephalosporin, against carbapenem-resistant hypervirulent Klebsiella pneumoniae in China

Cefiderocol is a siderophore cephalosporin that binds ferric iron and utilizes iron transporters to cross the cell membrane. Hypervirulent Klebsiella pneumoniae (hvKp) is known to produce more siderophores; in this case, the uptake of cefiderocol may be decreased. Therefore, the objective of this study was to evaluate the in vitro activity of cefiderocol against hvKp isolates. A total of 320 carbapenem-resistant K. pneumoniae (CRKp) isolates were collected in China between 2014 and 2022, including 171 carbapenem-resistant hvKp (CR-hvKp) and 149 carbapenem-resistant classical K. pneumoniae (CR-cKp). Quantitative detection of siderophores showed that the average siderophore production of CR-hvKp (234.6 mg/L) was significantly higher than that of CR-cKp (68.9 mg/L, P < 0.001). The overall cefiderocol resistance rate of CR-hvKp and CR-cKp was 5.8% (10/171) and 2.7% (4/149), respectively. The non-susceptible rates of both cefiderocol and siderophore production of CR-hvKp isolates were higher than those of CR-cKp in either NDM-1- or KPC-2-producing groups. The MIC90 and MIC50 for CR-hvKp and CR-cKp were 8 mg/L and 2 mg/L and 4 mg/L and 1 mg/L, respectively. The cumulative cefiderocol MIC distribution for CR-hvKp was significantly lower than that of CR-cKp isolates (P = 0.003). KL64 and KL47 consisted of 53.9% (83/154) and 75.7% (53/70) of the ST11 CR-hvKp and CR-cKp, respectively, and the former had significantly higher siderophore production. In summary, cefiderocol might be less effective against CR-hvKp compared with CR-cKp isolates, highlighting the need for caution regarding the prevalence of cefiderocol-resistant K. pneumoniae strains, particularly in CR-hvKp isolates.

[A preliminary study on the establishment of a subcutaneous allergen-specific immunotherapy center]

Allergic diseases can notably affect a patient's quality of life. World Health Organization (WHO) has identified these diseases as one of the key areas for research and prevention in the 21st century. Currently, allergen-specific immunotherapy is viewed as a potential treatment approach that could modify the natural progression of allergic diseases, thus being recognized as a crucial tactic in their prevention and treatment. Nonetheless, the broad implementation of allergen-specific immunotherapy in clinical settings continues to confront challenges. One significant issue is the absence of standardized centers for subcutaneous allergen-specific immunotherapy. This article presents several perspectives and recommendations for establishing a standardized subcutaneous allergen-specific immunotherapy center.

A dual-process of targeted and unbiased Nanopore sequencing enables accurate and rapid diagnosis of lower respiratory infections

BACKGROUND

Nanopore metagenomics has been used for infectious disease diagnosis for bacterial pathogens. However, this technology currently lacks comprehensive performance studies in clinical settings for simultaneous detection of bacteria, fungi, and viruses.

METHODS

We developed a dual-process of Nanopore sequencing for one sample, with unbiased metagenomics in Meta process and target enrichment in Panel process (Nanopore Meta-Panel process, NanoMP) and prospectively enrolled 450 respiratory specimens from multiple centers. The filter system of pathogen detection was established with machine learning and receiver operator characteristic (ROC) curve to optimize the detection accuracy based on orthogonal test of 21 species. Antimicrobial resistance (AMR) genes were identified based on the Comprehensive Antibiotic Resistance Database (CARD) and single-nucleotide polymorphism matrix.

FINDINGS

Our approach showed high sensitivity in Meta process, with 82.9%, 88.7%, and 75.0% for bacteria, fungi (except Aspergillus), and Mycobacterium tuberculosis groups, respectively. Moreover, target amplification improved the sensitivity of virus (>80.0% vs. 39.4%) and Aspergillus (81.8% vs. 42.3%) groups in Panel process compared with Meta process. Overall, NanoMP achieved 80.2% sensitivity and 98.8% specificity compared with the composite reference standard, and we were able to accurately detect AMR genes including blaKPC-2, blaOXA-23 and mecA and distinguish their parent organisms in patients with mixed infections.

INTERPRETATION

We combined metagenomic and enriched Nanopore sequencing for one sample in parallel. Our NanoMP approach simultaneously covered bacteria, viruses and fungi in respiratory specimens and demonstrated good diagnostic performance in real clinical settings.

FUNDING

National Key Research and Development Program of China and National Natural Science Foundation of China.

[Value of fecal immunochemical test in colorectal cancer screening]

Screening and early diagnosis and treatment have been proven effective in reducing the incidence and mortality of colorectal cancer. Colonoscopy combined with pathological examination is the gold standard for colorectal cancer screening. However, due to the invasiveness, high cost and the need for professional endoscopists of colonoscopy, it is not feasible to directly use this method for mass population screening. Fecal immunochemical test (FIT) is one of the screening techniques recommended by authoritative international guidelines for colorectal cancer screening, and has been widely used in population-based colorectal cancer screening programs in countries around the world. This paper elaborates on the value of FIT in colorectal cancer screening from different aspects, such as the technical principles, the screening efficiency, the screening strategies, and the population effects and benefits. Additionally, it describes the current situation of colorectal cancer screening in China and summarizes the challenges faced in colorectal cancer screening in order to optimize the FIT-based colorectal cancer screening strategies in the population and provide theoretical reference for effective colorectal cancer screening.

Efficacy and Safety of Local Radiotherapy Combined with Chemotherapy ± Bevacizumab in the Treatment of Patients with Advanced and Recurrent Metastatic Cervical Cancer

PURPOSE/OBJECTIVE(S)

To observe the efficacy and safety of local radiotherapy combined with chemotherapy ± bevacizumab in the treatment of patients with advanced or recurrent metastatic cervical cancer.

MATERIALS/METHODS

A total of 53 patients with advanced and recurrent metastatic cervical cancer who had received local radiotherapy combined with chemotherapy ± bevacizumab in Affiliated Cancer Hospital of Guizhou Medical University from July 2018 to October 2021 were collected. The recurrence types included 21 patients of pelvic recurrence, 7 patients of distant metastasis, 14 patients of complex pelvic recurrence and distant metastasis, and 11 patients of advanced stage (initial diagnosis stage IVB). The primary endpoints were objective response rate (ORR) and disease control rate (DCR). The secondary endpoints were progression-free survival (PFS), overall survival (OS) and incidence of adverse reactions.

RESULTS

(1) Complete response (CR) was achieved in 4 patients (7.5%), partial response (PR) in 34 patients (64.2%), stable disease (SD) in 12 patients (22.6%), and disease progression (PD) in 3 patients (5.7%), ORR was 71.7%, DCR was 94.3%. (2) The follow-up time was 5.3 to 45.7 months, the median OS was 29.3 months, the median PFS was 15.7 months, the one-year and two-year OS were 83.0% and 59.2%, and the 1-year and two-year PFS were 62.2% and 34.4%. (3) Recurrence type, tumor size at the time of recurrence, and efficacy after radiotherapy were significant factors for PFS and OS rates in multivariate analysis. (4) The main adverse reactions were myelosuppression, gastrointestinal reaction and urinary reaction. Grade IV leukopenia occurred at 13.2%, grade IV neutropenia at 11.3%, grade IV thrombocytopenia at 15.1%, and grade IV anemia at 5.7%, all of which were tolerable. The gastrointestinal and urinary reactions were mainly grade I-II, and the incidence of vesical or rectovaginal fistulas was about 7.5% (2 patients had rectovaginal fistulas and 2 patients had vesto-vaginal fistulas).

CONCLUSION

Local radiotherapy combined with chemotherapy ± bevacizumab can improve the efficacy and survival of patients with advanced and recurrent metastatic cervical cancer. Adverse reactions are tolerable and may provide survival benefits in these patients.

Silva Classification System for HPV-Related EAC of Stage I ∼ IIIc1p Cervical Adenocarcinoma and Its Effect on Prognosis and Survival

PURPOSE/OBJECTIVE(S)

The proportion of adenocarcinoma in cervical cancer gradually increased and presented a younger trend. The previous pathological classification of cervical adenocarcinoma is difficult to provide reference for clinical treatment. In recent years, Silva classification, a new pathologic system for cervical adenocarcinoma, has been confirmed to be suitable for HPV-associated adenocarcinoma (HPVA), and has shown certain clinical application value in subsequent studies. Therefore, this study will retrospectively analyze the distribution of Silva typing system in patients with HPVA under standard treatment mode and its relationship with prognosis and survival.

MATERIALS/METHODS

From January 2010 to September 2021, 124 cervical adenocarcinoma patients with HPVA were retrospectively included, who underwent radical resection of cervical cancer. The HE staining sections of the patients were divided into SilvaA, SilvaB, and SilvaC types according to the Silva typing system. Kaplan-Meier calculation was used for single-factor analysis, and COX stepwise regression model was used for multi-factor analysis.

RESULTS

Of the 124 patients with HPVA who could be graded according to the Silva system, 16 (12.9%, 16/124) were SilvaA, 27 (21.7%, 27/124) SilvaB, and 81 (65.4%, 81/124) SilvaC. In Silva classification, FIGO staging of Silva A and B was stage I. And FIGO staging of Silva C was more significantly later than the staging of Silva A and B. All lymph node metastases and paruterine infiltrates were found only in Silva C. In addition, the patients with Silva C large mass accounted for a higher proportion (41.7%). SilvaA type cervical adenocarcinoma patients were in a survival state by the end of follow-up. Among Silva B, 3 patients died due to tumor, and the 5-year OS rate were 91.3%. Among SilvaC, 15 patients died due to tumor, and the 5-year OS rate were 76.5%. FIGO stage and lymph node invasion were the influencing factors for survival and prognosis of Silva classification (P <0.05). FIGO stage, tumor size, lymph node invasion, and paralegal invasion were the influencing factors for survival and prognosis of SilvaC patients (P <0.05).

CONCLUSION

Silva model classification system combined with clinicopathological features has certain clinical value for the prognostic guidance of HPVA patients. Among Silva classification, SilvaC had the worst prognosis. Late FIGO stage, lymph node metastasis, and paralegal infiltration are the influencing factors for survival and prognosis of SilvaC type.

Clinical characteristics and prognosis of pneumonia-related bloodstream infections in the intensive care unit: a single-center retrospective study

Background

Bloodstream infections (BSI) are one of the most severe healthcare-associated infections in intensive care units (ICU). However, there are few studies on pneumonia-related BSI (PRBSI) in the ICU. This study aimed to investigate the clinical and prognostic characteristics of patients with PRBSI in the ICU and to provide a clinical basis for early clinical identification.

Methods

We retrospectively collected data from patients with bacterial BSI in a single-center ICU between January 1, 2017, and August 31, 2020. Clinical diagnosis combined with whole-genome sequencing (WGS) was used to clarify the diagnosis of PRBSI, and patients with PRBSI and non-PRBSI were analyzed for clinical features, prognosis, imaging presentation, and distribution of pathogenic microorganisms.

Results

Of the 2,240 patients admitted to the MICU, 120 with bacterial BSI were included in this study. Thirty-two (26.7%) patients were identified as having PRBSI based on the clinical diagnosis combined with WGS. Compared to patients without PRBSI, those with PRBSI had higher 28-day mortality (81.3 vs.51.1%, p = 0.003), a higher total mortality rate (93.8 vs. 64.8%, p = 0.002), longer duration of invasive mechanical ventilation (median 16 vs. 6 days, p = 0.037), and prolonged duration of ICU stay (median 21 vs. 10 days, p = 0.004). There were no differences in other baseline data between the two groups, but patients with PRBSI had extensive consolidation on chest radiographs and significantly higher Radiographic Assessment of Lung Edema scores (mean 35 vs. 24, p < 0.001). The most common causative organisms isolated in the PRBSI group were gram-negative bacteria (n = 31, 96.9%), with carbapenem-resistant gram-negative bacteria accounting for 68.8% (n = 22) and multidrug-resistant bacteria accounting for 81.3% (n = 26).

Conclusion

Pneumonia-related BSI is an important component of ICU-BSI and has a poor prognosis. Compared to non-PRBSI, patients with PRBSI do not have typical clinical features but have more severe lung consolidation lesions, and should be alerted to the possibility of their occurrence when combined with pulmonary gram-negative bacterial infections, especially carbapenem-resistant bacteria. Further multicenter, large-sample studies are needed to identify the risk factors for the development of PRBSI and prevention and treatment strategies.

Within-host acquisition of colistin-resistance of an NDM-producing Klebsiella quasipneumoniae subsp. similipneumoniae strain through the insertion sequence-903B-mediated inactivation of mgrB gene in a lung transplant child in China

Background

Colistin, as the antibiotic of "last resort" for carbapenem-resistant Klebsiella, develop resistance during administration of this antimicrobial agent. We identified an NDM-1-producing Klebsiella quasipneumonuae subsp. similipneumoniae (KQSS) strain KQ20605 recovered from a child, which developed resistance to colistin (KQ20786) through acquiring an IS903B element between the -27th and -26th bp of mgrB promoter region after 6-day colistin usage.

Objectives

The aim of this study is to explore the source of IS903B in the disruptive mgrB gene and its underlying mechanisms.

Materials and methods

Antibiotics susceptibility testing was conducted via microbroth dilution method. The in vitro colistin-induced experiment of KQ20605 was performed to mimic the in vivo transition from colistin-sensitive to resistant. Whole-genome sequencing was used to molecular identification of colistin resistance mechanism.

Results

The IS903B element integrated into mgrB gene of KQ20786 had a 100% nucleotide identity and coverage match with one IS903B on plasmid IncR, and only 95.1% (1005/1057) identity to those on chromosome. In vitro, upon the pressure of colistin, KQ20605 could also switch its phenotype from colistin-sensitive to resistant with IS elements (e.g., IS903B and IS26) frequently inserted into mgrB gene at "hotspots", with the insertion site of IS903B nearly identical to that of KQ20786. Furthermore, IS26 elements in this isolate were only encoded by plasmids, including IncR and conjugative plasmid IncN harboring bla NDM.

Conclusion

Mobilizable IS elements on plasmids tend to be activated and integrated into mgrB gene at "hotspots" in this KQSS, thereby causing the colistin resistance emergence and further dissemination.

Carbapenem-resistant Citrobacter freundii harboring blaKPC-2 and blaNDM-1: a study on their transferability and potential dissemination via generating a transferrable hybrid plasmid mediated by IS6100

Introduction

The increase in clinical Enterobacteriaceae with dual carbapenemase has become a serious healthcare concern. It is essential to characterize the transferability and potential dissemination of blaKPC-2- and blaNDM-1-coharboring carbapenem-resistant Citrobacter freundii (CRCF).

Methods

Four blaKPC-2- and blaNDM-1-coharboring CRCF strains were collected from our surveillance of the prevalence of carbapenem-resistant Enterobacteriaceae. The isolates were assessed using species identification, antimicrobial susceptibility testing, conjugation assays, whole-genome sequencing, plasmid stability, and fitness costs. Clonality, genome, plasmidome, and phylogeny were analyzed to reveal potential dissemination.

Results

Three ST523 blaKPC-2- and blaNDM-1-coharboring CRCF strains, collected from the same hospital within 1 month, exhibited high homology (both identity and coverage >99%), implying clonal dissemination and a small-scale outbreak. Moreover, the blaKPC-2 and blaNDM-1 genes were coharbored on an IncR plasmid, probably generated by a blaKPC-2-harboring plasmid acquiring blaNDM-1, in these three strains. Importantly, the IncR plasmid may form a transferable hybrid plasmid, mediated by IS6100 via transposition, with another IncFII plasmid included in the same C. freundii strain. Furthermore, the blaKPC-2 and blaNDM-1 of the fourth CRCF strain are located on two different non-transferable plasmids lacking complete transfer elements. Additionally, throughout the course of the 10-day continuous passage, the genetic surroundings of blaNDM-1 in four CRCF strains were gradually excised from their plasmids after the 8th day, whereas they maintained 100% retention for blaKPC-2. Genome and plasmidome analyses revealed that blaKPC-2- or blaNDM-1-harboring C. freundii were divergent, and these plasmids have high homology to plasmids of other Enterobacteriaceae.

Conclusion

Clonal dissemination of ST523 blaKPC-2- and blaNDM-1-coharboring CRCF strains was detected, and we first reported blaKPC-2 and blaNDM-1 concomitantly located on one plasmid, which could be transferred with mediation by IS6100 via transposition. Continued surveillance should urgently be implemented.

Comparison of Performances of GeneXpert MTB/RIF, Bactec MGIT 960, and Bactec Myco/F Systems in Detecting Mycobacterium tuberculosis in Biopsy Tissues: a Retrospective Study

Tuberculosis remains a major global public concern as a leading cause of health care-associated infections. The detection of Mycobacterium tuberculosis (MTB) is challenging due to the paucibacillary nature of the pathogen. For suspected pulmonary and extrapulmonary tuberculosis patients, if sputum, bronchoalveolar lavage fluid (BALF), related samples are negative for MTB, or suspected tumors, biopsy tissues may provide a better diagnostic yield. This study was aimed at comparing the performances of three methods in identifying MTB in biopsy tissues, including the Bactec mycobacterial growth indicator tube 960 (MGIT 960) system, the GeneXpert MTB/RIF assay (GeneXpert), and the Bactec Myco/F lytic culture (Myco/F) system. Biopsy samples from 3,209 nonduplicated patients were retrospectively enrolled between January 2018 and September 2021, of which 180 (5.6%) were positive for MTB by at least one method. GeneXpert revealed the highest recovery rate (134/162, 82.7%), followed by MGIT 960 (99/135, 73.3%) and Myco/F (26/143, 18.1%), and the composite positive rate for GeneXpert and MGIT 960 was 96.6% (173/179). Pairwise comparisons were conducted after completion of both tests, and the results showed that Myco/F had significantly lower detection rates than GeneXpert and MGIT 960 (16.4% versus 82.8%, P < 0.001; 14.3% versus 71.4%, P < 0.001). In summary, GeneXpert was the most sensitive and recommended method for MTB detection in biopsy tissues, and the combination of GeneXpert and MGIT 960 could improve the overall diagnostic yield. IMPORTANCE Mycobacterium tuberculosis (MTB) poses a severe threat to public health worldwide. The diagnosis of tuberculosis is challenging due to the low load of the microorganism in samples. Biopsy tissues are sometimes collected via invasive procedures with limited size, and additional samples are often inaccessible. The GeneXpert MTB/RIF assay, Bactec MGIT 960 system, and Bactec Myco/F lytic system have been used in detecting MTB in our laboratory. Here, we evaluated the performances of these three methods in 3,209 biopsy tissues samples to establish a more effective protocol based on clinical requirements. Attempts for a locally optimized protocol should be always made.

Azithromycin Exposure Induces Transient Microbial Composition Shifts and Decreases the Airway Microbiota Resilience from Outdoor PM2.5 Stress in Healthy Adults: a Randomized, Double-Blind, Placebo-Controlled Trial

Inappropriate antibiotic prescriptions are common for patients with upper respiratory tract infections (URTIs). Few data exist regarding the effects of antibiotic administration on airway microbiota among healthy adults. We conducted a randomized, double-blind, placebo-controlled trial to characterize the airway microbiota longitudinally in healthy adults using 16S rRNA gene sequencing and quantification. Both the induced sputum and oral wash samples were collected over a 60-day period following a 3-day intervention with 500 mg azithromycin or placebo. Environmental information, including air quality data (particulate matter [PM2.5] and PM10, air quality index [AQI] values), were also collected during the study. A total of 48 healthy volunteers were enrolled and randomly assigned into two groups. Azithromycin did not alter bacterial load but significantly reduced species richness and Shannon index. Azithromycin exposure resulted in a decrease in the detection rate and relative abundance of different genera belonging to Veillonellaceae, Leptotrichia, Fusobacterium, Neisseria, and Haemophilus. In contrast, the relative abundance of taxa belonging to Streptococcus increased immediately after azithromycin intervention. The shifts in the diversity of the microbiology composition took between 14 and 60 days to recover, depending on the measure used: either UniFrac phylogenetic distance or α-diversity. Outdoor environmental perturbations, especially the high concentration of PM2.5, contributed to novel variability in microbial community composition of the azithromycin group at D30 (30 days after baseline). The network analysis found that azithromycin altered the microbial interactions within airway microbiota. The influence was still obvious at D14 when the relative abundance of most taxa had returned to the baseline level. Compared to the sputum microbiota, oral cavity microbiota had a different pattern of change over time. The induced sputum microbial data can represent the airway microbiota composition in healthy adults. Azithromycin may have transient effects in the airway microbiota of healthy adults and decrease the airway microbiota resilience against outdoor environmental stress. The influence of azithromycin on microbial interactions is noteworthy, although the airway microbiota has returned to a near-baseline level. IMPORTANCE The influence of antibiotic administration on the airway microbiota of healthy adults remains unknown. This study is a randomized, double-blind, placebo-controlled trial aiming to investigate the microbial shifts in airways after exposure to azithromycin among heathy adults. We find that azithromycin changes the airway microbial community composition of healthy adults and decreases the airway microbiota resilience against outdoor environmental stress. This study depicts the longitudinal recovery trajectory of airway microbiota after the antibiotic perturbation and may provide reference for appropriate antibiotic prescription.

[Research on applying genetic and environmental risk score in risk-adapted colorectal cancer screening]

Objective: To evaluate the effectiveness of a risk-adapted colorectal cancer screening strategy constructed utilizing genetic and environmental risk score (ERS). Methods: A polygenic risk score (PRS) was constructed based on 20 previously published single nucleotide polymorphisms for colorectal cancer in East Asian populations, using 2 160 samples with MassARRAY test results from a multicenter randomized controlled trial of colorectal cancer screening in China. The ERS was calculated using the Asia-Pacific Colorectal Screening Score system. Logistic regression was used to analyze the association between PRS alone and PRS combined with ERS and colorectal neoplasms risk, respectively. We also designed a risk-adapted screening strategy based on PRS and ERS (high-risk participants undergo a single colonoscopy, low-risk participants undergo an annual fecal immunochemical test, and those with positive results undergo further diagnostic colonoscopy) and compared its effectiveness with the all-acceptance colonoscopy strategy. Results: The high PRS group had a 26% increased risk of colorectal neoplasms compared with the low PRS group (OR=1.26, 95%CI: 1.03-1.54, P=0.026). Participants with the highest PRS and ERS were 3.03 times more likely to develop advanced colorectal neoplasms than those with the lowest score (95%CI: 1.87-4.90, P<0.001). As the risk-adapted screening simulation reached the third round, the detection rate of the PRS combined with ERS strategy was not statistically different from the all-acceptance colonoscopy strategy (8.79% vs. 10.46%, P=0.075) and had a higher positive predictive value (14.11% vs. 10.46%, P<0.001) and lower number of colonoscopies per advanced neoplasms detected (7.1 vs. 9.6, P<0.001). Conclusion: The risk-adapted screening strategy combining PRS and ERS helps achieve population risk stratification and better effectiveness than the traditional colonoscopy-based screening strategy.

In vitro Synergistic Activity of Ceftazidime-Avibactam in Combination with Aztreonam or Meropenem Against Clinical Enterobacterales Producing blaKPC or blaNDM

Background

It is often challenging to select appropriate combination therapies to treat infections caused by carbapenem-resistant Enterobacterales (CRE) with high-level resistance to carbapenem.

Methods

We investigated the in vitro synergistic activity of ceftazidime-avibactam-, polymyxin- or tigecycline-, and meropenem-based combinations using checkerboard assays against 16 CRE including Klebsiella pneumoniae carrying bla_KPC-2 (CR1-bla_KPC-2) and Enterobacter cloacae carrying bla_NDM-1 (CR2-bla_NDM-1) with meropenem MICs ≥128 mg/L. Time-kill assays were used to observe synergistic bactericidal activity.

Results

Meropenem in combination with ertapenem, amikacin, tigecycline or polymyxin B, and tigecycline plus ceftazidime-avibactam showed weak synergistic activities against CR1-bla_KPC-2 and CR2-bla_NDM-1. Polymyxin B combined with tigecycline or ceftazidime-avibactam, and ceftazidime-avibactam plus amikacin showed synergistic effects against two tigecycline-non-susceptible KPC-producers or three ceftazidime-avibactam-resistant NDM-producer, and 50% (5/10) of strains with amikacin MICs ≥4096 mg/L, respectively. Synergistic interactions of ceftazidime-avibactam plus aztreonam or meropenem in checkerboard assays were measured for 100% (16/16) and 93.8% (15/16) of strains, respectively. The time-kill assay further verified that the ceftazidime-avibactam combination had the potential to restore aztreonam susceptibility and reduced meropenem MICs to 8 mg/L.

Conclusion

Ceftazidime-avibactam plus aztreonam or meropenem could be an effective strategy for treating CRE infections, particularly those with high-level resistance to carbapenems and/or ceftazidime-avibactam.

Evaluation of BACTEC MGIT 960 system for recovery of Nocardia from clinical specimens

Nocardia spp. is an aerobic Gram-positive bacillus responsible for nocardiosis. Herein, we performed a retrospective study to evaluate the performance of BACTEC MGIT 960 system, in comparison with smear microscopy and blood agar plate (BAP) culture, to recover Nocardia from different clinical specimens. Furthermore, the inhibitory effect of antibiotics contained in MGIT 960 tube on Nocardia was also evaluated. The sensitivities for Nocardia recovery using smear microscopy, BAP culture, and MGIT 960 were 39.4% (54/137), 46.1% (99/215), and 81.3% (156/192), respectively. N. farcinica was the most detected species (60.4%, 136/225). In MGIT 960-recovered Nocardia strains, N. farcinica accounted for 76.9%. Furthermore, trimethoprim in MGIT 960 tube inhibited less N. farcinica growth than that of other Nocardia species, partially explaining why MGIT 960 recovered more N. farcinica from sputa. The current study demonstrated that MGIT 960 could recover Nocardia strains from heavily-contaminated samples if its components and antibiotics are redesigned.

Phenylacetylglutamine as a novel biomarker of type 2 diabetes with distal symmetric polyneuropathy by metabolomics

PURPOSE

Type 2 diabetes mellitus (T2DM) with distal symmetric polyneuropathy (DSPN) is a disease involving the nervous system caused by metabolic disorder, while the metabolic spectrum and key metabolites remain poorly defined.

METHODS

Plasma samples of 30 healthy controls, 30 T2DM patients, and 60 DSPN patients were subjected to nontargeted metabolomics. Potential biomarkers of DSPN were screened based on univariate and multivariate statistical analyses, ROC curve analysis, and logistic regression. Finally, another 22 patients with T2DM who developed DSPN after follow-up were selected for validation of the new biomarker based on target metabolomics.

RESULTS

Compared with the control group and the T2DM group, 6 metabolites showed differences in the DSPN group (P < 0.05; FDR < 0.1; VIP > 1) and a rising step trend was observed. Among them, phenylacetylglutamine (PAG) and sorbitol displayed an excellent discriminatory ability and associated with disease severity. The verification results demonstrated that when T2DM progressed to DSPN, the phenylacetylglutamine content increased significantly (P = 0.004).

CONCLUSION

The discovered and verified endogenous metabolite PAG may be a novel potential biomarker of DSPN and involved in the disease pathogenesis.

[Research progress on the role of adipose-derived stem cell exosomes in skin scar formation]

The adipose-derived stem cell exosomes are subcellular structures of adipose stem cells. They are nano-sized membrane vesicles that can transport various cell components and act on target cells by paracrine, and they play an important role in the exchanges of substance and information between cells. Scar healing is the commonest way of healing after skin tissue injury. Pathological scar can not only cause movement dysfunction, but also lead to deformity, which affects the appearance of patients and brings life and mental pressure to the patients. In recent years, many researches have shown that the adipose-derived stem cell exosomes contain a variety of bioactive molecules, which play an important role in reducing scar formation and scar-free wound healing, by affecting the proliferation and migration of fibroblasts and the composition of extracellular matrix. This article reviewed the recent literature on the roles and mechanisms of adipose-derived stem cell exosomes in scar formation, and prospected the future application and development of adipose-derived stem cell exosomes in scar treatment.

The thoracoabdominal wall abscess and sepsis caused by Porphyromonas pogonae: Case report and literature review

Background

Porphyromonas pogonae was first reported in 2011 from polymicrobial infections in central bearded dragons. Human infections caused by P. pogonae remain rare, with only four cases published in the PubMed database. Herein, we present an unusual Chinese case of the thoracoabdominal wall abscess with sepsis caused by P. pogonae and review the clinical manifestations, diagnostic evaluation, and clinical outcome of the case.

Case presentation

A 62-year-old female with sinusitis but no diabetes mellitus presented with fever, tenderness under an abdominal mass, and paroxysmal stabbing pain in the chest after receiving augmentation mammoplasty. Cultures of blood and pus yielded P. pogonae, and a diagnosis of sepsis with an abscess in the chest and abdominal wall was made. After repeated debridement and appropriate meropenem antibiotic treatment, the patient was successfully treated and discharged home.

Conclusions

We report the first human case of P. pogonae causing sepsis in a patient with an abscess in China. The identification of P. pogonae should be considered if the strain grows well under either anaerobic or microaerobic conditions and exhibits strong β-hemolysis with fluorescence. This study retrospectively reviewed patients' infection diagnosis, clinical treatment, and prognosis to enhance awareness of the risk of P. pogonae infection.

Genetic Diversity of Polymyxin-Resistance Mechanisms in Clinical Isolates of Carbapenem-Resistant Klebsiella pneumoniae: a Multicenter Study in China

Polymyxin has been the last resort to treat multidrug-resistant Klebsiella pneumonia. However, recent studies have revealed that polymyxin-resistant carbapenem-resistant Klebsiella pneumonia (PR-CRKP) emerged due to the mutations in chromosomal genes or the plasmid-harboring mcr gene, leading to lipopolysaccharide modification or efflux of polymyxin through pumps. Further surveillance was required. In the present study we collected PR-CRKP strains from 8 hospitals in 6 provinces/cities across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features by whole-genome sequencing (WGS). The broth microdilution method (BMD) was performed to determine the MIC of polymyxin. Of 662 nonduplicate CRKP strains, 15.26% (101/662) were defined as PR-CRKP; 10 (9.90%) were confirmed as Klebsiella quasipneumoniae by WGS. The strains were further classified into 21 individual sequence types (STs) by using multilocus sequence typing (MLST), with ST11 being prevalent (68/101, 67.33%). Five carbapenemase types were identified among 92 CR-PRKP, blaKPC-2 (66.67%), blaNDM-1 (16.83%), blaNDM-5 (0.99%), blaIMP-4 (4.95%), and blaIMP-38 (0.99%). Notably, 2 PR-CRKP strains harbored both blaKPC-2 and blaNDM-1. The inactivation of mgrB, associated significantly with high-level polymyxin resistance, was mainly caused by the insertion sequence (IS) insertion (62.96%, 17/27). Furthermore, acrR was inserted coincidently by ISkpn26 (67/101, 66.33%). The deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47 (capsule locus types), and diverse mutations of the ramR gene were identified. Only one strain carried the mcr gene. In summary, the high IS-inserted mgrB inactivation, the close relationship between ST11 and the deletion or splicing mutations of the crrCAB, and the specific features of PR-K. quasipneumoniae constituted notable features of our PR-CRKP strains in China. IMPORTANCE Polymyxin-resistant CRKP is a serious public health threat whose resistance mechanisms should be under continuous surveillance. Here, we collected 662 nonduplicate CRKP strains across China to identify the carbapenemase and polymyxin resistance genes and epidemiological features. Polymyxin resistance mechanism in 101 PR-CRKP strains in China were also investigated, 9.8% of which (10/101) were K. quasipneumoniae, as determined via WGS, and inactivation of mgrB remained the most crucial polymyxin resistance mechanism, significantly related to high-level resistance. Deletion or splicing mutations of crrCAB were significantly associated with ST11 and KL47. Diverse mutations of the ramR gene were identified. The plasmid complementation experiment and mRNA expression analysis further confirmed that the mgrB promoter and ramR played a critical role in polymyxin resistance. This multicenter study contributed to the understanding of antibiotic resistance forms in China.

Within-host resistance evolution of a fatal ST11 hypervirulent carbapenem-resistant Klebsiella pneumoniae

OBJECTIVES

Hypervirulent carbapenem-resistant Klebsiella pneumoniae (hv-CRKp) has become a great threat to public health. This study reported an hv-CRKp-associated fatal infection and revealed its mechanisms of antimicrobial resistance and within-host evolution.

METHODS

A carbapenem-susceptible K. pneumoniae (CSKp) and 11 KPC-producing CRKp strains were isolated from a lung transplant recipient receiving continual antimicrobial therapy for 1.5 years. Pulsed-field gel electrophoresis (PFGE) separated two clusters between CSKp and CRKp.

RESULTS

Further whole genome sequencing analysis found that all 11 CRKp were ST11-KL64 clones, while the CSKp was ST412-KL57. Among these 11 CRKp strains, three and one were resistant to colistin and ceftazidime/avibactam (CAZ/AVI), respectively. Three different mechanisms were found to be responsible for the colistin resistance, including the insertions of two different IS (ISKpn74 and IS903B) into the same position of mgrB and one related to the efflux pump system. CAZ/AVI resistance was associated with bla_KPC-2 mutation, and it was also found that increasing bla_KPC-2 expression increased the MICs of CAZ/AVI, but not at the resistance level. All these 12 strains had iucABCDiutA virulence cluster and rmpA/rmpA2 genes, with higher siderophore production than a reference classic K. pneumoniae (cKp), which were thought to be hypervirulent K. pneumoniae (hvKp). However, only the CSKp showed higher mucoviscosity according to the mucoviscosity assay. Genomic analysis showed that the rmpA variation (interrupted by ISKpn26) existed in all CRKp strains except the CSKp strain, demonstrating that hypermucoviscous phenotype assays could not accurately identify hvKp.

CONCLUSION

This study depicted a rapid and diverse within-host evolution of resistance in hv-CRKp of ST11-KL64 clone.

Concurrent pigeon paramyxovirus-1 and Acinetobacter baumannii infection in a fatal case of pneumonia

Pigeon paramyxovirus type 1 (PPMV-1), an antigenic variant of avian paramyxovirus type 1 (APMV-1), mainly infects pigeons. PPMV-1 genotype VI is the dominant genotype infecting pigeons in China. Human infection of avian paramyxovirus was rarely reported, and usually developed mild symptoms, such as conjunctivitis. We detected PPMV-1 in the lower respiratory sample from a fatal case with severe pneumonia; this patient aged 64 years presented cough, fever, and haemoptysis for 8 days and was admitted to hospital on Dec 26, 2020. He developed acute respiratory distress syndrome and sepsis in the following days and died of multiple organ failure on Jan 7, 2021. Sputum and blood culture reported multidrug-resistant Acinetobacter baumannii (ABA) for samples collected on days 22 and 19 post-illness, respectively. However, clinical metagenomic sequencing further reported PPMV-1 besides ABA in the bronchoalveolar lavage fluid. The PPMV-1 genome showed 99.21% identity with a Chinese strain and belonged to VI genotype by BLAST analysis. Multiple basic amino acids were observed at the cleavage site of F protein (113RKKRF117), which indicated high virulence of this PPMV-1 strain to poultry. The patient had close contact with pigeons before his illness, and PPMV-1 nucleic acid was detected from the pigeon feather. PPMV antibody was also detected in the patient serum 20 days after illness. In conclusion, concurrent PPMV-1 genotype VI.2.1.1.2.2 and ABA infection were identified in a fatal pneumonia case, and cross-species transmission of PPMV-1 may occur between infected pigeons and the human being.

[Short-term efficacy and safety of vedolizumab in patients with inflammatory bowel disease]

Objective: To evaluate the short-term efficacy and safety of vedolizumab in patients with inflammatory bowel disease (IBD). Methods: Patients with moderate and severe active IBD at the first use of vedolizumab from May 1 to October 31, 2021 were retrospectively enrolled. Then the clinical characteristics, and the efficacy and safety of vedolizumab were evaluated. Meanwhile, the clinical response rate, biological response rate and endoscopic response rate were calculated. Multivariate analysis was used to evaluate the independent influencing factors of short-term clinical efficacy and safety. Results: A total of 78 patients (44 males and 34 females) with IBD were enrolled, with a mean age of (40.5±11.9) years. The clinical remission rate, clinical response rate, biological remission rate, biological response rate and endoscopic remission rate was 60.3% (47/78), 85.9% (67/78), 70.5% (55/78), 43.6% (34/78) and 47.0% (31/66) respectively after 14 weeks of treatment. Body mass index (BMI) ≥ 18.5 kg/m² (HR=5.04, 95%CI: 1.50-16.91, P=0.009) and biological remission at 6 weeks of treatment (HR=15.22, 95%CI: 3.16-73.38, P=0.001) were predictors of endoscopic remission at 14 weeks of treatment. Adverse reactions occurred in 57 patients, with an incidence of 73.1%. The main manifestations were liver and kidney damage (37.2%) and infection (26.9%). Conclusions: More than half of patients with moderate and severe active IBD can achieve clinical remission after 14 weeks of vedolizumab treatment. Baseline BMI level and biological remission at 6 weeks of treatment are predictors of mucosal healing at 14 weeks. The incidence of adverse reactions is not low, although serious adverse reactions are rare in short-term treatment.

Convergence of MCR-8.2 and Chromosome-Mediated Resistance to Colistin and Tigecycline in an NDM-5-Producing ST656 Klebsiella pneumoniae Isolate From a Lung Transplant Patient in China

We characterized the first NDM-5 and MCR-8.2 co-harboring ST656 Klebsiella pneumoniae clinical isolate, combining with chromosomal gene-mediated resistance to colistin and tigecycline. The K. pneumoniae KP32558 was isolated from the bronchoalveolar lavage fluid from a lung transplant patient. Complete genome sequences were obtained through Illumina HiSeq sequencing and nanopore sequencing. The acquired resistance genes and mutations in chromosome-encoded genes associated with colistin and tigecycline resistance were analyzed. Comparative genomic analysis was conducted between mcr-8.2-carrying plasmids. The K. pneumoniae KP32558 was identified as a pan-drug resistant bacteria, belonging to ST656, and harbored plasmid-encoded blaNDM-5 and mcr-8.2 genes. The blaNDM-5 gene was located on an IncX3 type plasmid. The mcr-8.2 gene was located on a conjugative plasmid pKP32558-2-mcr8, which had a common ancestor with another two mcr-8.2-carrying plasmids pMCR8_020135 and pMCR8_095845. The MIC of KP32558 for colistin was 256 mg/L. The mcr-8.2 gene and mutations in the two-component system, pmrA and crrB, and the regulator mgrB, had a synergistic effect on the high-level colistin resistance. The truncation in the acrR gene, related to tigecycline resistance, was also identified. K. pneumoniae has evolved a variety of complex resistance mechanisms to the last-resort antimicrobials, close surveillance is urgently needed to monitor the prevalence of this clone.

[Preliminary efficacy of ab interno canaloplasty combined with micro-incision cataract surgery in primary open angle glaucoma combined with cataract: one-year results]

Objective: To evaluate the preliminary efficacy and safety of ab interno canaloplasty (ABiC) combined with micro-incision cataract surgery for treating primary open angle glaucoma (POAG) combined with cataract. Methods: Prospective case series study. Patients diagnosed with POAG and concurrent cataract were enrolled to receive ABiC combined with micro-incision phacoemulsification and intraocular lens implantation in the Eye Center of the Second Affiliated Hospital of Zhejiang University School of Medicine from June 2018 to October 2019. Intraocular pressure (IOP), use of hypotensive medications, visual acuity, visual field, and optic nerve at baseline as well as at 1 day, 1 week, 1 month, 3 months, 6 months, and 12 months postoperatively were assessed. Subgroup analyses were further performed to evaluate these data between controlled and uncontrolled POAG, as well as among mild, moderate, and advanced POAG. Success rate and complications were analyzed. Results: A total of 68 eyes in 42 patients completed a follow-up of 12 months. Compared to the baseline IOP under medical control [(18.25±2.65) mmHg (1 mmHg=0.133 kPa)], the mean postoperative IOP at 1 month [(14.31±3.25) mmHg], 3 months [(14.00±3.09) mmHg], 6 months[ (14.58±2.93) mmHg], and 12 months[ (14.84±2.73) mmHg] was all significantly reduced (P<0.05). The median (upper quadrant, lower quadrant) of the hypotensive medication number was 2.5 (2, 3) at baseline, which was significantly reduced to 0 (0, 1) at 1 month, and 0 (0, 0) at 3, 6, and 12 months (P<0.05). The complete success rate and qualified success rate at 12 months were 80.88%(55/68) and 89.71%(61/68), respectively. No deterioration in the visual field or optical coherence tomography scan of the optic nerve was observed at 12 months compared to the baseline status. Hyphema (26 eyes, 38.24%) and transient IOP spike (23 eyes, 33.82%) were the most common complications, but no severe case was present. Conclusion: ABiC combined with micro-incision cataract surgery is considerably effective and safe in the treatment of POAG combined with cataract in the Chinese population.

Prevalence, Incidence, and Progression of Radiographic and Symptomatic Hand Osteoarthritis: The Osteoarthritis Initiative

OBJECTIVE

To describe prevalence, incidence, and progression of radiographic and symptomatic hand osteoarthritis (OA), and evaluate age, sex, race and risk factors differences.

METHODS

We assessed both radiographic and symptomatic hand OA at baseline and year 4 for incident disease. A modified poisson regression with a robust variance estimator was used to account for clustering of joints within fingers within persons to estimate the prevalence ratios and relative risk estimates associated with participant characteristics.

RESULTS

Of 3588 participants, the prevalence hand OA was 41.4% for radiographic hand OA and 12.4 % for symptomatic hand OA. The incidence of hand OA over 48 months was 5.6 % for radiographic hand OA, and 16.9 % for symptomatic hand OA. Over 48 months, 27.3 % participants exhibited OA progression. We found complex differences by age, sex and race with both men and women having increasing prevalent hand OA with age, but women peaking at age 55-65, for incident disease. Women have more symptomatic hand OA than men but only non-significantly higher rates for incident radiographic hand OA. Women have more distal interphalangeal joint disease while men have more metacarpal joint OA. Black men and women have less hand OA than whites but black men have more hand OA than black women at younger ages.

CONCLUSION

Hand OA is a heterogeneous disease with complex differences by age, sex and race, hand symptoms and patterns of specific joints. Further research investigating the mechanisms behind these differences whether mechanical, metabolic, hormonal, or constitutional is warranted.

Clinical characteristics of patients with bronchiectasis with nontuberculous mycobacterial disease in Mainland China: a single center cross-sectional study

BACKGROUND

The diagnosis and treatment of patients with bronchiectasis and nontuberculous mycobacterium (NTM) pulmonary disease are challenging issues and the treatment is also prolonged and depends on the species. There is limited information on patients with bronchiectasis and NTM pulmonary disease in Mainland China.

METHODS

This cross-sectional study was conducted at the China-Japan Friendship Hospital, Beijing, China. Those adult patients who met the diagnostic criteria for bronchiectasis and obtained a culture result of mycobacteria from lower respiratory tract specimens or lung tissue were included in this study. A logistic regression model was used to identify the related factors in patients with NTM pulmonary disease.

RESULTS

A total of 202 patients with bronchiectasis from 19 cities, 155 without and 47 (23.3%) with NTM pulmonary disease, were included. In all the 47 patients with NTM pulmonary disease, Mycobacterium avium complex was the most common species (66.0%), and 72.3% of them were initiated on standard anti-NTM treatment within 3 months after the diagnosis of NTM pulmonary disease. A larger proportion of patients with NTM pulmonary disease had acute exacerbations of ≥ 3 times within 1 year and were diagnosed bronchiectasis ≥ 50 years among patients with NTM pulmonary disease. The HRCT chest images revealed higher proportions of nodular shadow (100% vs. 35.3%), tree-in-bud sign (97.9% vs. 29.0%), cavities (29.8% vs. 5.8%), and airway dilation of the right middle lobe or the left lingular lobe (63.8% vs. 23.9%) in patients with NTM pulmonary disease than in those without NTM pulmonary disease (all P values = 0.001). The multivariable logistic regression model indicated that three and more abnormal features (OR 33.8; 95% CI 11.1-102.8) and main lesions of bronchial expansion in the middle or lingual lobe (OR 6.4; 95% CI 2.4-16.6) in HRCT chest images were independently associated with NTM pulmonary disease (P values = 0.001).

CONCLUSION

In a single center of Mainland China, > 23% of patients with bronchiectasis had NTM pulmonary disease, and most patients were started on standard treatment within 3 months after the diagnosis of NTM pulmonary disease. These findings suggest that patients with bronchiectasis should be thoroughly examined for the presence of NTM pulmonary disease.

TRIAL REGISTRATION

NCT03594032.

Prospective Evaluation of a Rapid Clinical Metagenomics Test for Bacterial Pneumonia

Background

The diagnosis of bacterial pathogens in lower respiratory tract infections (LRI) using conventional culture methods remains challenging and time-consuming.

Objectives

To evaluate the clinical performance of a rapid nanopore-sequencing based metagenomics test for diagnosis of bacterial pathogens in common LRIs through a large-scale prospective study.

Methods

We enrolled 292 hospitalized patients suspected to have LRIs between November 2018 and June 2019 in a single-center, prospective cohort study. Rapid clinical metagenomics test was performed on-site, and the results were compared with those of routine microbiology tests.

Results

171 bronchoalveolar lavage fluid (BAL) and 121 sputum samples were collected from patients with six kinds of LRIs. The turnaround time (from sample registration to result) for the rapid metagenomics test was 6.4 ± 1.4 hours, compared to 94.8 ± 34.9 hours for routine culture. Compared with culture and real-time PCR validation tests, rapid metagenomics achieved 96.6% sensitivity and 88.0% specificity and identified pathogens in 63 out of 161 (39.1%) culture-negative samples. Correlation between enriched anaerobes and lung abscess was observed by Gene Set Enrichment Analysis. Moreover, 38 anaerobic species failed in culture was identified by metagenomics sequencing. The hypothetical impact of metagenomics test proposed antibiotic de-escalation in 34 patients compared to 1 using routine culture.

Conclusions

Rapid clinical metagenomics test improved pathogen detection yield in the diagnosis of LRI. Empirical antimicrobial therapy could be de-escalated if rapid metagenomics test results were hypothetically applied to clinical management.

[Quantitative myocardial perfusion parameters in subjects without coronary artery lesions based on computed tomography dynamic myocardial perfusion imaging]

Objective: To determinate the range of quantitative myocardial perfusion parameters (MBF, MBV) in subjects without coronary artery lesions by dynamic computed tomography myocardial perfusion imaging (CTP). Methods: Subjects with occasional chest tightness or family history of coronary artery disease coming to Fuwai Hospital underwent coronary computed tomography angiography (CCTA) were prospectively enrolled. A total of 34 subjects [mean age (50±7) years, range from 33 to 65 years; 15 male and 19 female] were enrolled. Coronary lesions were not confirmed in any subjects using CCTA and volunteered for stress and rest dynamic CTP examination. MBF and MBV values were calculated in each myocardial segment using a 17-segment model. The global ranges of MBF and MBV were analyzed, and the gender variability and regional variability were compared. Results: The mean global MBF and MBV at rest and under stress were (115.5±27.4) ml·100 g^-1·min^-1, (212.8±40.8) ml·100 g^-1·min^-1 and (17.6±4.0) ml/100 g, (25.8±4.6) ml/100 g, respectively. The absolute and resolute reserves of MBF and MBV [(102.8±41.5) ml·100 g^-1·min^-1, 107.7%±52.5%; (9.3±5.2) ml/100 g, 62.1%±47.4%] were highest in the right coronary artery territory, but without any significant differences. The stress MBF and absolute reserve of MBF in females were higher than those of males [(228.6±39.9) ml·100 g^-1·min^-1, (113.3±46.2) ml·100 g^-1·min^-1; (192.8±33.4) ml·100 g^-1·min^-1, (77.0±41.2) ml·100 g^-1·min^-1] (both P<0.05). The MBF resolute reserve, rest MBV, stress MBV and MBV absolute and resolute reserves were higher in females, but without significant differences (all P>0.05). Conclusion: The mean global MBF and MBV at rest and under stress were (115.5±27.4) ml·100 g^-1·min^-1, (212.8±40.8) ml·100 g^-1·min^-1 and (17.6±4.0) ml/100 g, (25.8±4.6) ml/100 g. The MBF under stress perfusion and MBF absolute reserve of females are higher than those of males.

In vivo Selection of Imipenem Resistance Among Ceftazidime-Avibactam-Resistant, Imipenem-Susceptible Klebsiella pneumoniae Isolate With KPC-33 Carbapenemase

We describe in vivo evolution of carbapenem and ceftazidime-avibactam resistance by analyzing four longitudinal Klebsiella pneumoniae clinical isolates from a patient with pneumonia following antimicrobial treatment. The patient had fever, cough associated with expectoration, and new infiltration was found on the chest CT. Antimicrobial susceptibility was determined, and whole genome sequencing (WGS) was performed to investigate its dynamic change of resistance phenotype. Population analysis profile was performed to investigate the population of Klebsiella pneumoniae. The infection started with a KPC-2-producing K. pneumoniae (ZRKP01, ceftazidime-avibactam-S/carbapenem-R). Then, after ceftazidime-avibactam treatment, the strain switched to D179Y mutant that is KPC-33 (ZRKP02, ceftazidime-avibactam-R/carbapenem-S), which restored carbapenem susceptibility. However, the restored carbapenem susceptibility in vivo was not stable and the subsequent use of imipenem against KPC-33-producing K. pneumoniae infection resulted in a reversion of KPC-2 producers (ZRKP03 and ZRKP04, ceftazidime-avibactam-S/carbapenem-R). Genetic analysis demonstrated that all four K. pneumoniae isolates belonged to sequence type 11and had identical capsular polysaccharide (KL47), identical porin genes, and same plasmid replicon types. Phylogenetic analysis indicated that four K. pneumoniae isolates showed a high degree of relatedness. Single nucleotide polymorphisms analysis indicated that the number of mutations observed in the KPC-33 isolate was more than in the wild-type KPC-2 isolates and the four KPC-Kp isolates evolved from a longitudinal evolution of K. pneumoniae harboring bla_KPC-2 gene. This is the first report to observe the in vivo evolution of wild-type KPC-2 to KPC-33 and then the reversion to its original wild-type KPC-2. Through WGS, we demonstrated the role of selective pressure of antibiotic in the mutation and reversion of bla_KPC genes, which leading to the dynamic change of KPC enzymes and the dynamic emergence of resistance to ceftazidime-avibactam and carbapenems.

Statement: Recently, studies reported the emergence of ceftazidime-avibactam-resistant strains. The KPC mutations mediating ceftazidime-avibactam resistance are generally associated with the restoration of carbapenem susceptibility. However, clinical significance of this observation is unclear. In this manuscript, we demonstrate the role of selective pressure of antibiotic in the mutation and reversion of bla_KPC genes, which leading to the dynamic change of KPC enzymes and the dynamic emergence of resistance to ceftazidime-avibactam and carbapenems. To the best of our knowledge, this is the first report to observe the in vivo evolution of wild-type KPC-2 to KPC-33 and then the reversion to its original wild-type KPC-2. It should be noted that understanding the clinical significance of this observation is of critical importance, and reversion to carbapenem susceptibility would not imply a potential role for carbapenems monotherapy. We hope our study will draw attention to clinicians, so that this agent can be used most effectively for the longest period of time.