| Background:Pseudomonas Aeruginosa belongs to the human conditional pathogensand wildly exist in nature.It can result in nosocomial infection,such asurinary tract infection,respiratory infection,dermatitis,chronic wounds ortissue infection,all kinds of systemic infection.The immunocompromisedpatients who were serious burns,malignant tumor,AIDS et.al weresusceptible population.The pathogenesis and prognosis of PA was based onthe production of virulence factor and biofilm formation.The virulencefactors of PA included:1.pili,the surface composition,related tomotiliny;2.the type III secretion system(T3SS),which secreted effectorprotein ExoS,ExoT,ExoU and ExoY which assisted the injection of toxins tothe host cell;3.quorum sensing system,which regulated bacteriacommunication,then regulated the production of virulence factor and biofilmformation;4.iron elimination,PA can produce two compounds which combine iron of the host and control the expression of virulence factors suchas exotoxin A and endonucleases;5.other virulence factors which werebeneficial to the planting and invading of PA,such as pili, flagellin, Surfacepolysaccharide, elastase, alkali protease, hemolysin, cytotoxic, compoundsand intaking system which combine iron and diffusible production ofpyocyanine.PA was one of the consitional pathogen of UTI. Nir Marcus reportedthat PA was the third UTI pathogen,following escherichia coli and Klebsiellapneumoniae.The treatment of non-Escherichia coli UTI was alwaysinappropriate.M. Bitsori reported that40%PA UTI patients gotinappropriate initial antibiotic therapy. Initial antibiotic therapy was startedbefore the urine culture result was available.PA was resistant to most firstline UTI antibiotic,so it’s important to study the risk factor of PA UTI andmonitor their susceptibility for improving curative effect and prognosis. M.Bitsori and N. Marcus respectively studied the risk factors,urine cultrure andantibiotics sensitivity results of community-acquired UTI in childrenincluding,and found that PA infections were more common in the childrenwith the history of at least1previous UTIepisode,hospitalization,vesicoureteral reflux，urinary operation，urinaryabnormanity or previous antibiotic use. At present domestic clinic researchabout PA UTIs is few.Objective: 1. To investigate the risk factors related with PA UTIs.2. To explore the drug resistance status of PA which caused UTIs.3. To explore the prognosis of PA UTIs.Methods:1. The clinic medical records of all clinic diagnosed PA UTI from Jan12006to Dec312011in Children’s Hospital of Chongqing MedicalUniversity were collected.For each P. aeruginosa UTI case2timematched children with E. coli UTI admitted next to the index P.aeruginosa case were chosen to form the control group.2. The clinic medical records of all included cases were studiedretrospectively.Parameters including age,gender,department,previoushospitalization,UTI,urinary tract operation,catheterization within theprevious week,underlying conditions,antibiotic use within the previous2months,use of the drug affecting immune system,clinic symptoms andsigns,finding on laboratory test,results of imaging studies,results ofantibiotics sensitivity,treatment before and after the result of urineculture,length of hospitalization and prognosis were recorded.3. The bacteria in the urine specimens was isolated and the antibioticsusceptibility was performed by Phoenix-100antomatic bacterialidentification/antibiotic susceptibility system.The operation of antibioticsusceptibility and result verification was performed by CLSI,using PAATCC27853and Escherichia coli ATCC25922(offered by clinic laboratory centre of Ministry of Health)as quality control.4. Prognostic index:recovery,i.e. the urine culture was negative,and/orurine routine was negative with clinic symptoms and signsdisappeared.Urinary tract operation,i.e. remove precipitating factor byurinary tract operation.Dead,i.e. died from serious infection andsystemic failure.Inappropriate initial antibiotic therapy,i.e. treated withinsensitive drug before urine culture test.And length of hospitalization.5. All the data were analyzed by SPSS software19.0version.Unpaired2-tailed Student’s t-test was used to compare continuous variablesbetween the two groups.For continuous variables without normaldistribution (i.e.,age), Mann-Whitney test was used. χ2or Fisher’s exactwas used to compare categorical variables.All significant variables byunivariate analysis were examined by multivariate logistic regressionanalysis to identify independent risk factors.The results were presentedas OR with95%CI and p level of each coefficient.Significance was setat p<0.05.Result1.45patients with PA UTI and90patients with Escherichia coli UTI wereincluded.The age of PA group was between0.30-15.17years old,medianage was5.00years old.The age of control group was between0.08-14.08years old,median age was3.00years old. The age difference wasstatistically significant(p=0.009).PA group was older. Number difference of older than2years old was statistically significant (p=0.011),also thePA group was more.The number of male in PA group was36(80%),andcontrol group38(42.22%). The sex difference was statisticallysignificant(χ~2=17.286,p=0.000). Community acquired infection in PAgroup was25(55.56%),and control group59(65.56%). The difference ofcommunity acquired infection and hospital infection between two groupwas not statistically significant(χ~2=0.09,p=0.902).2. We compared the follow variables after reading articles about risk factorof PA UTI all over the world. The differences of previous urinary tractoperation(χ~2=10.628,p=0.001),catheterization (including urethralcatheterization operation and retention catheterization)within theprevious week(χ~2=10.385,p=0.001),long-term use of the drug affectingimmune system(χ~2=6.344,p=0.012)were statistically significant.Butthere were not statistically significant in the differences of number ofchronic renal insufficiency(χ~2=2.888,p=0.089), neurogenicbladder(χ~2=1.063,p=0.303), vesicoureteral reflux(χ~2=0.104,p=0.747),urinarytractdeformity(χ~2=2.065,p=0.151),at least1UTIepisode(χ~2=0.090,p=0.746),neurological/skeletal/anorectal anomalies(χ~2=3.704,p=0.054),tumor(χ~2=0.000,p=1.000) and antibiotic use withinthe previous2months (χ~2=2.912,p=0.088).3. All significant variables(including:sex,older than2years, previousurinary tract operation, catheterization, long-term use of the drug affecting immune system) by univariate analysis were examined bymultivariable logistic regression analysis.We found that the ORs of themwere more than1,but just the Ps of sex(p=0.002), previous urinary tractoperation(p=0.019), long-term use of the drug affecting immunesystem(p=0.002) were less than0.05.4. Most children in two groups were hospitalized for fever,respectively26.67%of PA group and32.22%of control group. The numberdifference of fever was not statisticallysignificant(χ~2=0.438,p=0.508)..Children without fever were admittedfor edema(PA group:11.11%,contol group:6.67%),decrease in urineoutput(PA group:13.33%,contol group:5.56%),hematuresis(PA group:4.44%,contol group:12.22%),dysuresia(PA group:28.89%,contol group:12.22%),frequent urgency urination and odynuria(PA group:2.22%,contol group:12.22%),cloudyurine(PA group:2.22%,contolgroup:4.44%).5. Comparing the data of laboratory test,the difference ofpolymorphonuclear cell proportion(T=2.500,p=0.014)andalbumin(T=-2.190,p=0.031)were statistically significant.The differenceof leukocyte (T=-0.780,p=0.437),hemoglobin (T=1.586,p=0.115),C-reactive peptide (χ~2=1.151,p=0.283) and creatinine (T=0.626,p=0.533)were not statistically significant.There was not positive result of bloodclutrue in the two group. 6. Compared with clinic outcome,the difference of length of hospitalization(T=2.746,p=0.007)was not statistically significant.The mean ofhospitalization days of experimental group was more than the contralgroup. The difference of inappropriate initial antibiotic therapy(p=0.015)was statistically significant,the experimental group was also more.Thedifferences of dead patients(p=0.156)and urinary tract operation(p=0.661)were not statistically significant.There was just one patientdied who was from the experimental group.7. The results of antibiotics sensitivity presented that the resisatant rate ofimipenem (4.44%)was the lowest. The resisatant rates was4.88%formeropenem,6.06%for polymyxin,8.82%forPiperacillin-tazobactam,11.43%for Ciprofloxacin,11.90%levofloxacin,13.33%for amikacin,26.67%for ceftazidime,29.55%forCefepime,31.11%for gentamicin,32.35%for Piperacillin,40.00%foraztreonam. |
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