ObjectiveTo explore the relationship between imipenem-resistant Pseudomonas aeruginosa (IRPA) and outer membrane porin protein OprD2 gene mutation.MethodsIRPA strains (n=30) and imipenem-sensitive Pseudomonas aeruginosa strains (n=30) isolated from the clinical specimens in the First Affiliated Hospital of Chengdu Medical College from December 2018 to December 2019 were collected. Bacteria identification and drug sensitivity experiments were performed by VITEK-2 Compact combined with Kirby-Bauer method. Quantitative real-time polymerase chain reaction was used to detect the expression levels of OprD2 gene in the imipenem-resistant group and the imipenem-sensitive group, and then the strains with decreased expression were sequenced.ResultsThe expression level of OprD2 gene in the imipenem-resistant group was significantly lower than that in the imipenem-sensitive group (P=0.048). Compared with the X63152 sequence, all the 11 Pseudomonas aeruginosa strains with significantly decreased OprD2 expression carried genetic variation, which occurred in coding regions. The variation sites presented diversity. The missense mutation of c.308C→G, c.344A→C, c.379G→C, c.471G→C, c.508T→C, c.553G→C, c.556-558CCG→GGC and c.565-566TG→AC caused amino acid change in the loop L2 and L3 of OprD2 porin, which affected the binding to imipenem. In addition, the mutations at 127, 169-171, 175, 177, 604, 628-630, 688, 719, 785, 826, 828, 842-843, 886, 901, 928-930, 934, 936, 944-945, 1039, 1041 and 1274 all resulted in the changes of amino acid. We also detected a deletion (c.1114-1115delAT) and other nonsense mutations. Large fragment deletion of OprD2 gene occurred in Strain 12. ConclusionsThe mutation and deletion of OprD2 gene can reduce the expression lever of OprD2 gene, leading to the resistance to imipenem of Pseudomonas aeruginosa. The variation of OprD2 gene of IRPA from clinical strains is diverse.
摘要:目的:探讨新生儿铜绿假单胞菌肺炎的临床特点及药敏特点,为合理治疗提供依据。方法:对我院新生儿科2006年8月到2008年7月收治新生儿肺炎痰标本进行培养分离鉴定,选择培养结果为铜绿假单胞菌者做药敏及临床分析。结果:铜绿假单胞菌对碳青霉烯类,如:亚胺培南,美洛培南敏感率达100%,对近几年在新生儿较少用的或不用的氨基糖甙类,环丙沙星敏感率为85%～100%,而对常用的氨苄西林+舒巴坦不敏感,对头孢他啶敏感率gt;70%,临床根据药敏结果选择敏感抗生素治疗,疗效满意。结论:近年新生儿铜绿假单胞菌肺炎有上升趋势,病死率极高,故应根据药敏试验结果选择敏感抗生素,以控制疾病发展,降低病死率。
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.
ObjectiveTo evaluate the safty of recurrent laryngeal nerve (RLN) and parathyroid if Pseudomonas aeruginosa injection (PAI) is used after total thyroidectomy and central neck dissection (CND).MethodsFrom Mar. 2016 to Oct. 2017, we recruited 113 patients with papillary thyroid cancer (PTC) who accepted total thyroidectomy and CND. During operation, 1 mL of PAI was applied in 58 patients (local spray group) and 55 not (control group). The hoarseness, hypoparathyroidism, chylous fistula, drainage volume, hospital stay, and incidence of complications were compared between the two groups.ResultsThe two groups embraced few difference in age, gender, BMI, tumor site, the diameter of tumor and the number of metastatic and the harvested lymph nodes (P>0.05). There were nobody who has suffered in hoarseness and permanent hypoparathyroidism in both groups at any time after operation. There was no significant differences of complication between the two groups. The drainage volume at 24 h after operation in the local spraying group was more than that in the control group, and the difference was statistically significant (P=0.023). There were 2 patients had chylous fistula after surgery in the control group but none in the local spray group. The total volumes of drainage, incidence of fever and incision infection, the mean stay in the hospital, and the postoperative pain score had no statistic significance in the both groups.ConclusionAfter total thyroidectomy and CND, local spraying of PAI in the wound cavity is safe and will not damage the recurrent laryngeal nerve.
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.
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
摘要:目的:探讨老年耐亚胺培南铜绿假单胞菌(IRPA)感染的危险因素以指导临床救治。 方法:采用病例对照研究,选取四川省人民医院干部科2006年1月~2008年12月IRPA院内感染老年患者32例,并随机选择同时期敏感铜绿假单胞菌院内感染48例作为对照,采用单因素(t检验,χ2检验)及多因素Logistic回归进行分析。结果:IRPA分离率为34.8%,IRPA对抗生素的耐药性远远高于敏感铜绿假单胞菌组,但对阿米卡星敏感率达81.3%。单因素分析发现,下列因素与IRPA感染有关:高龄、住院时间≥4周、高急性生理和慢性健康状况(APACHEⅡ)评分、慢性肺部疾病(慢性阻塞性肺疾病COPD/支气管扩张)、分离出IRPA前2周用过亚胺培南/美罗培南、早期联用抗生素、院内获得性肺炎(HAP)。多因素Logistic回归分析表明:长程住院［比值比(OR)= 14.887］,APACHEⅡ评分≥16分(OR=38.908)以及分离出IRPA前2周用过亚胺培南/美罗培南(OR =12.945)是IRPA感染的独立危险因素。结论:长程住院、APACHEⅡ评分≥16分以及亚胺培南/美罗培南的使用是IRPA感染的危险因素。IRPA对阿米卡星敏感率相对较高,但治疗难度大。Abstract: Objective: To study the infection status and risk factors of nosocomial infection caused by imipenemresistant Pseudomonas aeruginosa (IRPA) in elderly patients. Methods: By a casecontrol study, the data of 32 cases of IRPA nosocomial infections were analyzed from Jan. 2006. to Dec. 2008 in cadres Ward of Sichuan Provincial People’s Hospital; 48 cases of Imipenemsensitive pseudomonas aeruginosa infection were randomized as control. Univariate analysis (T test and chisquare test )and multivariate logistic regression analysis were used for statistics. Results: The resistance to antibiotics of IRPA is much higher than the sensitive group.81.3％ of IRPA were sensitive to amikacin. According to univariate analysis,the factors associated with the infection caused by IRPA were age, length of stay in hospital more than 4 weeks, high score of APACHEⅡ, chronic pulmonary disease (COPD/bronchiectasis),imipenem/meropenem used 2 weeks before isolation of IRPA, early combination therapy of antibiotics and hospital acquired pneumonia (HAP). Multivariate logistic regression analysis identified three independent factors: Length of stay in hospital more than 4 weeks, APACHEⅡ score≥16 and imipenem/meropenem used 2 weeks before isolation of IRPA. Conclusion: Long length of stay in hospital, APACHEⅡ score ≥16 and previous imipenem/meropenem use were independent risk factors for IRPA infection. Although the sensitivity of IRPA to amikacin was relatively high, it was difficult to treat in clinical practice.
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.
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.
There is a worldwide consensus that urgent action is needed to prevent and control multi-drug resistant organisms in health care settings, especially carbapenem-resistant Enterobacteriaceae (CRE), carbapenem-resistant Acinetobacter baumannii (CRAB) and carbapenem-resistant Pseudomonas aeruginosa (CRPsA). In 2017, to focus on this topic, World Health Organization organized experts worldwide to develop guidelines for the prevention and control of CRE, CRPsA and CRAB. In this paper, we introduced the background, development process, main measures, advantages and disadvantages of the guidelines to help infection prevention and control practitioners take actions properly based on the guidelines.