Prevalence of hypermutator isolates of Achromobacter spp. from cystic fibrosis patients.
- 作者列表："Ridderberg W","Jensen Handberg K","Nørskov-Lauritsen N
:Bacteria colonising the lungs of cystic fibrosis (CF) patients encounter high selective pressures. Hypermutation facilitates adaptation to fluctuating environments, and hypermutator strains are frequently isolated from CF patients. We investigated the prevalence of hypermutator isolates of Achromobacter spp. among patients affiliated with the CF Centre in Aarhus, Denmark. By exposure to rifampicin, the mutation frequency was determined for 90 isolates of Achromobacter spp. cultured from 42 CF patients; 20 infections were categorised as chronic, 22 as intermittent. The genetic mechanisms of hypermutation were examined by comparing DNA repair gene sequences from hypermutator and normomutator isolates. Achromobacter spp. cultured from 11 patients were categorised as hypermutators, and this phenotype was exclusively associated with chronic infections. Isolates of the Danish epidemic strain (DES) of Achromobacter ruhlandii cultured from patients from both Danish CF centres showed elevated mutation frequencies. The hypermutator state of Achromobacter spp. was most commonly associated with nonsynonymous mutations in the DNA mismatch repair gene mutS; a single clone had developed a substitution in the S-adenosyl-L-methionine-dependent methyltransferase putatively involved in DNA repair mechanisms, but not previously linked to the hypermutator phenotype. Hypermutation is prevalent among clinical isolates of Achromobacter spp. and could be a key determinant for the extraordinary adaptation and persistence of DES.
: 囊性纤维化 (CF) 患者肺部定植的细菌遇到高选择性压力。超突变有利于适应波动的环境，超突变株经常从 CF 患者中分离。我们调查了无色杆菌属超突变分离株的流行情况。在丹麦奥胡斯 CF 中心附属的患者中。通过暴露于利福平，测定 90 株无色杆菌分离株的突变频率。从 42 例 CF 患者培养; 20 例感染分为慢性，22 例为间歇性。通过比较超突变和正突变分离株的 DNA 修复基因序列，检测超突变的遗传机制。无色杆菌属。从 11 例患者中培养出来的被归类为超突变，这种表型完全与慢性感染相关。从丹麦两个 CF 中心的患者培养的无色杆菌 ruhlandii 的丹麦流行株 (DES) 分离株显示突变频率升高。无色杆菌 spp 的超突变状态。最常与 DNA 错配修复基因 mutS 的非同义突变相关; 单个克隆在 S-腺苷-L-甲硫氨酸依赖性甲基转移酶中发生了取代，推测其参与 DNA 修复机制，但以前未与超突变表型相关。超突变在无色杆菌属的临床分离株中普遍存在。并且可能是 DES 非凡适应和持久性的关键决定因素。
METHODS:OBJECTIVES:To asses the clinical course in RA-related interstitial lung disease (RA-ILD) patients with and without rituximab (RTX). The influence of other variables was also evaluated. METHODS:A longitudinal multicentre study was conducted in RA diagnosed with ILD from 2007 until 2018 in Madrid. Patients were included in a registry [pNEumology RhEumatology Autoinmune diseases (NEREA)] from the time of ILD diagnosis. The main endpoint was functional respiratory impairment (FI), when there was a decline ≥5% in the predicted forced vital capacity compared with the previous one. Pulmonary function was measured at baseline and in follow-up visits every 6-12 months. The independent variable was therapy with RTX. Covariables included sociodemographic, clinical, radiological and other therapies. Survival techniques were used to estimate the incidence rate (IR) and 95% CI of functional impairment, expressed per 100 patient-semesters. Cox multivariate regression models were run to examine the influence of RTX and other covariates on FI. Results were expressed as the hazard ratio (HR) and CI. RESULTS:A total of 68 patients were included. FI occurred in 42 patients [IR 23.5 (95% CI 19, 29.1)] and 50% of them had FI within 1.75 years of an ILD diagnosis. A multivariate analysis showed that RTX exposure resulted in a lower risk of FI compared with non-exposure [HR 0.51 (95% CI 0.31, 0.85)]. Interstitial pneumonia, glucocorticoids, disease activity and duration also influenced FI. CONCLUSION:RA-ILD patients deteriorate over time, with the median time free of impairment being <2 years. Patients exposed to RTX had a higher probability of remaining free of FI compared with other therapies. Other factors have also been identified. Key words: rheumatoid arthritis, interstitial lung disease, observational study, rituximab and prognosis
METHODS:The safety of anti-programmed cell death 1 (PD-1) antibody for patients with preexisting interstitial lung disease (ILD) remains unknown. The aim of this study was to evaluate the dependence of preexisting ILD on anti-PD-1 antibody-induced pneumonitis in non-small cell lung cancer (NSCLC) patients. We retrospectively reviewed the association of preexisting ILD with the incidence, radiographic pattern, and outcome of pneumonitis in NSCLC patients receiving anti-PD-1 antibody. A total of 331 patients were included in this study. Of these patients, 17 had preexisting ILD. The incidence of pneumonitis was higher among the patients with preexisting ILD than among those without preexisting ILD (29% vs. 10%, P = 0.027). The distributions of the CT appearances at the onset of anti-PD-1 antibody-induced pneumonitis were as follows: for the patients with preexisting ILD, two patients (40%) had diffuse alveolar damage (DAD), one patient each with organizing pneumonia-like (OP), hypersensitivity pneumonitis (HP), and other patterns (20% each); for the patients without preexisting ILD, 19 patients (61%) had OP, 8 (26%) had HP, 3 (10%) had DAD, and 1 (3.2%) had other patterns. The median onset time from the initiation of anti-PD-1 antibody treatment until the development of pneumonitis was 1.3 months (range 0.3–2.1 months) for the patients with preexisting ILD and 2.3 months (range 0.2–14.6 months) for the patients without preexisting ILD. Careful attention to the development of pneumonitis is needed, especially within the first 3 months after the start of anti-PD-1 antibody treatment, when using anti-PD-1 antibody to treat patients with preexisting ILD.
METHODS::Bacteria of the Burkholderia cepacia complex (Bcc) are ubiquitous multidrug resistant organisms and opportunistic pathogens capable of causing life threatening lung infections among cystic fibrosis (CF) patients. No effective therapies are currently available to eradicate Bcc bacteria from CF patients, as these organisms are inherently resistant to the majority of clinically available antimicrobials. An immunoproteomics approach was used to identify Bcc proteins that stimulate the humoral immune response of the CF host, using bacterial cells grown under conditions mimicking the CF lung environment and serum samples from CF patients with a clinical record of Bcc infection. 24 proteins of the Bcc strain B. cenocepacia J2315 were identified as immunoreactive, 19 here reported as immunogenic for the first time. Ten proteins were predicted as extracytoplasmic, 9 of them being conserved in Bcc genomes. The immunogenic Bcc extracytoplasmic proteins are potential targets for development of novel therapeutic strategies and diagnostic tools to protect patients against the onset of chronic Bcc lung infections.