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.
Objective To investigate the predictors for carbapenem-resistant Acinetobacter baumannii, Enterobacteriaceae and Pseudomonas aeruginosa (CR-AEP) as the pathogens of bloodstream infection (BSI) for intensive care unit (ICU) patients. Methods A retrospective case-control study based on ICU- healthcare-associated infection (HAI) research database was carried out. The patients who have been admitted to the central ICU between 2015 and 2019 in the ICU-HAI research database of West China Hospital of Sichuan University were selected. The included patients were divided into two groups, of which the patients with ICU-acquired BSI due to CR-AEP were the case group and the patients with BSI due to the pathogens other than CR-AEP were the control group. The clinical features of the two groups of patients were compared. Logistic regression model was used to identify the predictors of BSI due to CR-AEP.ResultsA total of 197 patients with BSI were included, including 83 cases in the case group and 114 cases in the control group. A total of 214 strains of pathogenic bacteria were isolated from the 197 BSI cases, including 86 CR-AEP strains. The results of multivariate logistic regression analysis showed that previous use of tigecycline [odds ratio (OR)=2.490, 95% confidence interval (CI) (1.141, 5.436), P=0.022] was associated with higher possibility for CR-AEP as the pathogens of BSI in ICU patients with BSI, while previous use of antipseudomonal penicillin [OR=0.497, 95%CI (0.256, 0.964), P=0.039] was associated with lower possibility for that. Conclusion Previous use of tigecycline or antipseudomonal penicillin is the predictor for CR-AEP as the pathogens of BSI in ICU patients with BSI.
ObjectiveTo investigate the impact of postoperative application of Pseudomonas aeruginosa injection on recurrence free survival (RFS) and overall survival (OS) in patients with abnormal serum calcitonin levels following surgery for medullary thyroid carcinoma (MTC). MethodsA retrospective collection of data was conducted for 214 patients with abnormal serum calcitonin levels following MTC surgery at West China Hospital of Sichuan University from January 2015 to April 2024. Propensity score matching (1∶2) was utilized to match patients’ data to reduce confounding bias, comparing RFS and OS between patients who used (Pseudomonas group) and did not use (control group) Pseudomonas aeruginosa injection. ResultsAfter propensity score matching, 72 patients with abnormal postoperative calcitonin levels were included, with 24 in the Pseudomonas group and 48 in the control group. The median follow-up time for the 72 patients was 66 months (11–168 months). The 1-year RFS rates for the Pseudomonas group and the control group were 100% and 75.0%, respectively, and the 2-year RFS rates were 87.5% and 56.3%, respectively. The RFS in the Pseudomonas group was superior to that in the control group (χ2=4.791, P=0.029). The 5-year OS rates for the Pseudomonas group and the control group were 90.9% and 93.5%, respectively, with no significant difference between the two groups (χ2=0.469, P=0.491). The Cox proportional hazards regression model indicated that the median RFS was extended in the Pseudomonas group [25 months vs. 21 months, RR=0.350, 95%CI (0.135, 0.900), P=0.029], but there was no significant impact on OS [66 months vs. 69 months, RR=2.22, 95%CI (0.229, 21.444), P=0.503]. ConclusionPostoperative use of Pseudomonas aeruginosa injection in MTC patients with abnormal serum calcitonin level shows significant improvement in RFS, but no significant change in OS.
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 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 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.
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 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.
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.