Objective To explore the role of CD4+CD25+ Treg cells in chronic pulmonary infection caused by Pseudomonas aeruginosa(PA).Methods Sixty SD rats were randomly divided into a PA group and a control group(n=30 in each group).Chronic lung infection model was established by implantation of silicone tube precoated with PA into the main bronchus.Twenty-eight days later Treg cells in peripheral blood were measured by fluorescence-activated cell sorting（FACS）.Levels of IL-10 and TGF-β in serum were assayed by ELISA.The expression of Foxp3 mRNA in spleen was measured by RT-PCR.Pathological changes of lung tissue were studed by HE staining.Results Treg/CD4+ T cells in the PA group were significantly more than those in the control group[（19.79±6.45）% vs （5.15±0.47）%，Plt;0.05].The levels of IL-10 and TGF-β were (231.52±54.48)pg/mL and （121.05±7.98）pg/mL in the PA group respectively，which were significantly higher than those in the control group[（35.43±23.56）pg/mL and （36.02±8.94）pg/mL].The expression of Foxp3 mRNA in the PA group was significantly higher compared with the control group(0.80±0.044 vs 0.25±0.054，Plt;0.05）.HE staining revealed that PA caused a intensive inflammatory reaction with lymphocytes infiltration.Conclusion CD4+CD25+ Treg cell is up-regulated and plays an important role in chronic lung infection caused by Pseudomonas aeruginosa.
ObjectiveTo study the clinical features, short-term prognosis and risk factors of Pseudomonas Aeruginosa (P.aeruginosa) infection in patients with acute exacerbation of chronic obstructive pulmonary disease (AECOPD). MethodsThis study enrolled patients hospitalized for AECOPD in ten tertiary hospitals of China from September 2017 to July 2021. AECOPD patients with P.aeruginosa infection were included as case group, AECOPD patients without P.aeruginosa infection were randomly selected as control group from the same hospitals and same hospitalization period as the patients in case group, at a ratio of 2∶1. The differences in basic conditions, complications, clinical manifestations on admission and in-hospital prognosis between the two groups were compared, and the risk factors of P.aeruginosa infection were analyzed. ResultsA total of 14007 inpatients with AECOPD were included in this study, and 338 patients were confirmed to have P.aeruginosa infection during hospitalization, with an incidence rate of 2.41%. The in-hospital prognosis of AECOPD patients with P.aeruginosa infection was worse than that of the control group, which was manifested in higher hospital mortality (4.4% vs. 1.9%, P=0.02) and longer hospital stay [13.0 (9.0, 19.25)d vs. 11.0 (8.0, 15.0)d, P=0.002]. In terms of clinical features, the proportions of patients with cough, expectoration, purulent sputum, dyspnea in the case group were higher than those in the control group, and the inflammatory indicators (neutrophil ratio, erythrocyte sedimentation rate) and partial pressure of carbon dioxide in arterial blood gas were higher than those in the control group, while the serum albumin was significantly lower than that in the control group (all P<0.05). Multivariate logistic regression analysis showed that Parkinson's disease [odds ratio (OR)=5.14, 95% confidence interval (CI): 1.43 to 18.49, P=0.012], bronchiectasis (OR=4.97, 95%CI: 3.70 to 6.67, P<0.001), invasive mechanical ventilation (OR=2.03, 95%CI: 1.23 to 3.36, P=0.006), serum albumin<35 g/L (OR=1.40, 95%CI: 1.04 to 1.88, P=0.026), partial pressure of carbon dioxide ≥45 mm Hg (OR=1.38, 95%CI: 1.01 to 1.90, P=0.046) were independent risk factors for P.aeruginosa infection in AECOPD patients. ConclusionsP.aeruginosa infection has a relative high morbidity and poor outcome among AECOPD inpatients. Parkinson’s disease, bronchiectasis, invasive mechanical ventilation, serum albumin below 35 g/L, partial pressure of carbon dioxide ≥45 mm Hg are independent risk factors of P.aeruginosa infection in AECOPD inpatients.
Objectives To retrospectively analyze the isolation rate and drug-resistance of pseudomonas aeruginosa in Fuwai Hospital of Chinese Academy of Medical Sciences from 2013 to 2016. Methods The specimens were collected and cultured. If the isolated bacteria were from the same part of the same patient, the first isolated strains were only counted. The isolated pathogens were identified and the drug-resistance were analyzed. Results A total of 1 404 pseudomonas aeruginosa were isolated. The majority of them were from postoperative recovery room of surgery department (62.1%) and ICU of internal medicine (22.3%). The specimen source were mainly from respiratory tract (75.7%), followed by blood (10.0%) and venous catheter (5.5%). The resistance rate of piperacillin and piperacillin/sulbactam to pseudomonas aeruginosa was 0.6% to 10.4%. The resistance rate of ceftazidime and cefepime was 0.3% to 11.7%. The resistance rate of imipenem and meropenem was 7.6% to 20.1%. The resistance rate of amikacin, gentamicin, and tobramycin was 0.3% to 3.2%. The resistance rate of ciprofloxacin and levofloxacin was 0.6% to 5.2%. Conclusions The isolates of pseudomonas aeruginosa are mainly from postoperative recovery room of surgery department and ICU of internal medicine . Imipenem and meropenem are not the best choices for pseudomonas aeruginosa infection. It has great value to combine piperacillin, piperacillin/sulbactam, ceftazidime and cefepime with aminoglycoside or quinolone antibiotics for the treatment of pseudomonas aeruginosa infection which will reduce drug resistance.
Objective To describe and compare the distributions of aminoglycosides modifying enzymes ( AMEs) in imipenem-resistant Pseudomonas aeruginosa ( IRPA) collected from5 cities in China. Methods A total of 146 strains of IRPA were collected from 5 cities of China ( Chengdu, Hangzhou, Beijing, Shanghai, and Guangzhou) . The polymerase chain reaction ( PCR) were used to amplify the genes of AMEs in IRPA. Results Six positive genotypes were amplified out of 16 genotypes of AMEs by PCR. The total positive rate of AMEs is 65. 06% . The positive rates of genes of aac( 3) -Ⅱ, aac( 6′) -Ⅰ, aac( 6′) -Ⅱ, ant( 2″) -Ⅰ, ant ( 3″) -Ⅰ and aph( 3′) -Ⅵ were 33. 6% , 15. 8% , 19. 9% , 28. 8% , 14. 4%, and 4. 8% , respectively. The genotypes of AMEs were discrepant in different areas as 6 genotypes in Huangzhou and Shanghai, 4 genotypes in Chengdu and Beijing, and 3 genotypes in Guangzhou. Conclusion The results show that the positive rate of AMEs genes is high in IRPA, and the distribution is discrepant among different areas.
Objective To examine the effects of Pseudomonas aeruginosa(PA)quorum-sensing systems on airway mucus hypersecretion．Methods Sixty Sprague-Dawley rats were intubated with a silicone tube pre-coated with PAO1(wild-type PA strain)，PAO1-JP2(quorum-sensing-mutant strain)or saline in the bronchus．After 28 days，the mRNA and protein expression of MUC5AC in the rats’bronchial epithelia were detected by RT-PCR，alcian blue／periodic acid—Schif(AB／PAS)staining and enzyme linked immunosorbent assay(ELISA)．Results In the PAO1 group，bronchiolar epithelium goblet cells by AB／PAS staining was significantly more than those in the PAO1-JP2 and control groups(both Plt;0．05)．The expression level of MUC5AC mRNA in the PAO1 group was significantly higher than those in the PAO1-JP2 and control groups(both P lt;0．05)．The ELISA showed that the concentration of MUC5AC protein in bronchoalveolar lavage fluid(BALF)in the PAO1 group was much higher than that in the PAO1-JP2 group(P lt;0．05)．Conclusion PA quorum-sensing system plays an important role in airway mucus hypersecretion
Objective To establish a rat model of chronic pulmonary infection by inoculating Pseudomonas aeruginosa to Sprague-Dawley(SD) rats.Metods Sixty SD rats were divided into 2 groups,ie.the P.aeruginosa group and the control group. Silicone tube precoated with P.aeruginosa was placed into the main bronchus. For the control group, sterile silicon tube was intubated. Results P ． aeruginosa was detected from lung tissue of rats in infected groups.Bacterial number was higher than 103cfu ／ g 28 days after inoculation.The pathological study showed fibrinous proliferation and granulomas formation in the lungs of infected rats 28 days after inoculation.Microscopy examination showed a inflammation predominantly with lymphocyte infiltration.In control group, no bacterial and pathological changes could be detected. Conclusions The animal model with P.aeruginosa chronic pulmonary infection can be established successfully by silicone tubes precoated with P.aeruginosa intubated into the main bronchus.
Objective To explore the overall outcome and its factors of patients with carbapenem-resistant Pseudomonas aeruginosa bloodstream infection (CRPA-BSI). Methods A single-center, retrospective cohort study was carried out. The demographic and clinical data of all emergency patients and inpatients in West China Hospital of Sichuan University from 2017 to 2021 were collected. Firstly, the prognosis of patients with CRPA-BSI was compared with those with carbapenem-sensitive Pseudomonas aeruginosa bloodstream infection (CSPA-BSI). Then Cox regression was used to analyze the factors affecting the prognosis of CRPA-BSI patients. Results A total of 53 patients with CRPA-BSI and 175 patients with CSPA-BSI were enrolled, and they were 1∶1 matched according to the age-adjusted Charlson Comorbidity Index (aCCI) to control for confounding factors. When aCCI was similar, the incidence of poor prognosis in CRPA-BSI patients was significantly higher than that in CSPA-BSI patients [41.5% vs. 18.9%; relative risk=2.20, 95% confidence interval (CI) (1.16, 4.19), P=0.011]. The median length of hospital stay in the CRPA-BSI group was 3 d longer than that in the CSPA-BSI group but the difference was not statistically significant (29 vs. 26 d, P=0.388). With regard to prognostic factors, univariate Cox regression analyses showed that the highest temperature ≤39℃ (P=0.014), hepatobiliary and pancreatic diseases (P=0.011), days of central venous catheterization (P=0.025), days of indwelling urinary catheters (P=0.037), adjustment of medication duration according to drug sensitivity results (P=0.015) and Pitt bacteremia score (P=0.007) were related to the poor prognosis of CRPA-BSI patients. Multiple Cox regression analysis showed that hepatobiliary and pancreatic disease [hazard ratio (HR)=3.434, 95%CI (1.271, 9.276), P=0.015] and Pitt bacteremia score [HR=1.264, 95%CI (1.057, 1.510), P=0.010] were independently associated with poor outcome in CRPA-BSI patients. Conclusions The prognosis of CRPA-BSI patients is worsen than that of CSPA-BSI patients. Hepatobiliary and pancreatic diseases significantly increase the risk of poor outcome in CRPA-BSI patients. Pitt bacteremia score is a predictor of prognosis in patients with CRPA-BSI.
Objective To investigate the mutations of quinolone resistance determinational region ( QRDR) in fluoroquinolon-resistant Pseudomonas aeruginosa strains isolated from patients with nosocomial pneumonia. Methods Eight-four Pseudomonas aeruginosa strains isolated from patients with nosocomial pneumonia in Xinhua Hospital during January 2006 to December 2007, from whom fluoroquinolon-resistant resisitant ( case) and fluoroquinolon-susceptible ( control ) Pseudomona aeruginosa were identified. The mutation of QRDR was tested by restriction fragment length polymorphism ( RFLP) and gene sequencing.The relationship between QRDR mutations and clinical prescription was analyzed. Results Mutation in QRDR was found in 42 isolates among the 50 fluoroquinlon-resisitant isolates( 84. 0% ) , while no mutation was found in fluoroquinlon-susceptible isolates. The mutation in GyrB Ser464 was found in 34 isolates ( 68. 0% ) . There was statistical difference in the usage of β-lactams between the GyrB-Ser464-mutated group and the non-GyrB-Ser464-mutated group( OR = 11. 3, P = 0. 003 and OR = 3. 5, P = 0. 023) , also in the time of fluoroquinolon usage before isolated ( P = 0. 038) . Conclusions The mutation of QRDR is contributing to fluoroquindor-resisitance of Pseudomona aeruginosa, most of which lies in GyrB Ser464.Abuse of β-lactams and fluoroquinolon may be the risk factors of mutation in GyrB Ser464.
ObjectiveTo get a picture of the distribution of aminoglycoside-resistant genes in pseudomonas aeruginosa in China. MethodsWe electronically searched CBM, CNKI, VIP and WanFang Data for studies that reported aminoglycoside-resistant genes in pseudomonas aeruginosa in China from inception to December 2012. Two reviewers independently screened literature according to the inclusion and exclusion criteria, and extracted data. Then statistical analysis was performed using SPSS 17.0 software. ResultsA total of 1 144 strains of aminoglycoside-resistant pseudomonas aeruginosa from 10 provinces/cities were included. The positive rates of aac(3')-I, aac(3')-Ⅱ, aac(6')-I, aac(6')-Ⅱ, ant(2")-I, ant(3")-I and aph(3')-VI of aminoglycoside modifying enzyme genes were 13.3%, 40.1%, 21.6%, 40.3%, 38.1%, 23.7% and 2.9%, respectively to the north of Huai River, while the rates were 3.2%, 20.2%, 15.9%, 37.6%, 28.3%, 28.5% and 9.1%, respectively to the south of Huai River. The positive rates of rmtA, rmtB and armA of 16S rRNA methylases genes were 20.4%, 19.4% and 0.7%, respectively, while other 16S rRNA methylases genes were not found. ConclusionIn China, aminoglycoside modifying enzyme is the primary mechanism of pseudomonas aeruginosa aminoglycoside-resistant drugs, while 16S rRNA methylation enzyme mechanism is secondary.
Objective To evaluate the efficacy and safety of colistin in the treatment of severe infections. Methods PubMed, ISI Web of Knowledge and Wanfang databases were searched. The initial literatures and references listed in the literature were manually searched. Controlled studies were analyzed using RevMan 5. 0 software.Results Eleven studies were enrolled, including five prospective studies and six retrospective studies. Pooled analysis showed that, compared with other therapies, treatment with colistin in severe infections did not improve 28 or 30-day mortality, clinical symptoms, or bacteria clearance,however, increased the risk of kidney damage. Subgroup analysis showed that colistin did not improve symptoms, mortality ( which was even higher in the patients with drug resistant bacteria infection) , or kidney damage in drug resistant bacteria infections and ventilator associated pneumonia ( VAP) compared with the other antibiotic group. Conclusions Colistin is not superior to the other antibiotics in severe infections.However, there are some shortcomings in our meta-analysis due to limited high-quality RCTs, thus welldesigned RCTs are still needed before final conclusion is made.