Bacterial Distribution Of Urine Tract Infection And Evaluation On The Significance Of Routine Urinalysis

Objective Our study aimed to analyze the distribution and antimicrobial resistance ofpathogenic bacteria in urinary tract infection and evaluate the significance of routine urinalysis inthe diagnosis and prognosis of urinary tract infection.Methods Mid-stream urine culture were determined in13418patients from Jan2011to Dec2012in Shanghai Jiao Tong University Affiliated Sixth People’s Hospital，analyzing thedistribution and antimicrobial resistance of pathogenic bacteria. Routine urinalysis and mid-streamurine culture were determined in419untreated patients from Oct2012to Dec2012in ShanghaiJiao Tong University Affiliated Sixth People’s Hospital. The results of the WBC(white blood cell)counts，LE(Lekocyte esterase) and NIT(nitrate) were compared with urine cultures using ReceiverOperating Characteristic(ROC) curve analysis. The optimal values were obtained by calculatingthe area under ROC curve(AUC).The sensitivity，specificity, positive predictive value(PPV),negative predictive value (NPV)of WBC counts, LE,NIT,serial and parallel detection wereanalysis.Results A total of5923clinical isolates were collected from Jan2011to Dec2012, positiverate was44.1%.E.coil was the most prevalent specis, accounting for30.2%,the others includingfungus(6.1%),Klebsiella pneumonia(4.9%),Acinetobacter baumanii(4.7%),Enterococcusfaecalis(4.5%).E.coil collected from outpaitent showed high resistance rates toampicillin(86.4%),piperacillin(79.2%),ciprofloxacin(64.6%);while a low resistance rates toimipenem(0%),amikacin(7.1%),ceftazidime(17.2%);E.coil collected from inpaitent showed highresistance rates to ampicillin(86.4%),piperacillin(79.2%),ciprofloxacin(64.6%);while a lowresistance rates to imipenem(0.5%),amikacin(8.6%),ceftazidime(25%).Enterococcus faecaliscollected from outpaitent showed high resistance rates to gentamicin(60%)，erythromycin(50%)，ceftazidime(33.3%);while resistant rates to teicoplanin(0%), vancomycin(0%),nitrofuradantin(3.3%); Enterococcus faecalis collected from inpaitent showed high resistance ratesto erythromycin(87.1%),gentamicin(48.8%),ceftazidime(42.9%);while a low resistance rates toteicoplanin(0.7%), vancomycin(0.8%),nitrofurantoin(4.2%).Ancinetobacter Baumanii collectedfrom inpaitent showed higher resistance rates to available antibiotics than those collected from outpatient. The rate of multi-resistant bacteria was20.7%vs58.9%.The AUC of WBC counts, LE, NIT in first diagnosis group were0.727,0.730,0.650，eitherin prognostic group were0.668,0.649,0.653.In first diagnosis group, the sensitivity of WBCcounts,LE,NIT,serial and parallel detection were64.6%,75.0%,30.6%,30.6%,75.0%; specificitywere66.5%,62.5%,99.3%,99.3%,60.7%;PPV were50.3%,51.2%,95.7%,64.3%,50.0%and NPVwere78.2%,82.7%,73.2%,73.2%,82.3%.Correspond in prognosis group, the sensitivity of WBCcounts, LE,NIT,serial and parallel detection were69.6%,71.4%,35.7%,35.7%,73.2%;specificitywere54.4%,54.4%,94.7%,94.7%,47.4%;PPV were58.2%，66.0%，87.0%，87.0%，57.7%and NPVwere64.6%,65.6%,60.0%,60.0%,64.3%.Conclusions Female patients were more common in urinary tract infections, the proportionsincreased with age. E.coil was the most prevalent species. E.coil showed high resistance rates toampicillin, piperacillin, ciprofloxacin; while a low resistance rates to imipenem，amikacin，ceftazidime. Routine urinalysis has low sensitivity, not applicable for first diagnosis of urinarytract infection. The marker of NIT has high specificity and PPV, applicable for diagnosis ofurinary tract infection and empirical antibiotic treatment.