Risk Factors And Treatment Outcome For Ultidrug-resistant Klebsiella Pneumoniae Loodstream Infections In Children

Background Multidrug-resistance(MDR) is defined asnon-susceptibility to at least one agent in three or more antimicrobialcategories，which included carbapenem resistance and strains producingextended spectrum beta-lactamases(ESBLs).It was difficult to diagnosebloodstream infections(BSIs) in children and treat it,especially when theywere infected by multidrug-resistant(MDR) Klebsiella pneumoniae(KP).Itwas neccery to diagnosis and treat it as soon as possible because of the highmortality, which could help us to increase the rate of cure and reducemultidrug-resistance.Objective To assess risk factors,treatments for and outcome of MDRKlebsiella pneumoniae bloodstream infections in children.Methods There were34confirmed cases of MDR KP BSIs in theChildren′s Hospital of Chongqing Medical University from January2009toDecember2011.Their data of epidemiological,clinical characteristics andresults of antibiotic resistance were retrospectively analyzed.The data wereanalyzed by SPSS statistical analysis19.0software.MIC values were judged according to the guideline of CLSI.ESBLs were detected according to theNCCLS2000. The blaKPC were detected by PCR.Results Concomitant diseases included pneumonia and congenital heartdisease.Necrotizing enterocolitis(NEC) were only in neonatal andhematopoietic system tumors were only in non-neonatal.Common riskfactors for neonatal BSIs included prematurity, low birth weight,twins,previous use of invasive devices and history of perinatalasphyxia.Common risk factors for non-neonatal BSIs included previous useof invasive devices and neutropenia.There were significant differences inprevious treatment with carbapenems and cephalosporins between neonataland non-neonatal group and there were no significant differences in isolationof MDR and carbapenem resistance.The common prior antimicrobialexposure included second-generation cephalosporins andpiperacillin-tazobactam in neonatal.The common prior antimicrobialexposure included cephalosporins except forth-generation，piperacillin-tazobactam and carbapenems in neonatal.No pandrug-resistantstrains. The resistance to β-lactamase and β-lactamaseinhibitorscombinations was more than80%,and the resistance topiperacillin-tazobactam was the highest (97.1%) which showed anincreasing trend.The resistance to cephalosporins and aztreonam wasmore than85%,the lowest was ceftazidime (85.29%).There were4stainswith resistance to imipenem and meropenem(11.76%),3stains with ESBLs positive, and no blaKPC-2.All stains were susceptible to levofloxacin,and7strains were non-susceptible to ciprofloxacin.There were19stains withpositive ESBLs (19/25,76%),3stains with carbapenem resistance,9stainswith moxifloxacin resistance and2stains with amikacin resistancerespectively.The cure rate of empirical use of carbapenems (more than6days) was66.7%(10/15).8BSIs which respectively had treatment ofanti-fungal and anti-anaerobic bacteria were cured,and the treatments wereaccording to the concomitant diseases,for example hematopoieticmalignancies, NEC.The treatment of ciprofloxacin associated withmetronidazole for suspected NEC was effective in carbapenem resistantKlebsiella pneumoniae BSIs.The strains were positive ESBLs from thedeath cases,and carbapenem resistance KP BSIs were cured or better.Conclusion MDR of KP BSIs in our hospital was serious,and the rateof ESBLs producing KP was high.We must pay more attention to thepan-resistant KP. It was more common to infect MDR KP in children,whohad prior antimicrobial exposure of piperacillin-tazobactam,thesecond-generation cephalosporins,third-generation cephalosporins andcarbapenems. Strengthen the previous antibiotic therapy can improve theeffect of empirical therapy.We can reduce MDR infections by the rationaluse of antibiotics.Empirical therapy with carbapenems should be taken whenMDR KP BSIs were suspected, and combined with anti-anaerobic bacteria,anti-fungi bacteria according to concomitant diseases.The treatment of ciprofloxacin associated with metronidazole for suspected NEC waseffective in carbapenem resistant Klebsiella pneumoniae BSIs. The riskfactor for infection-related mortality was ESBLs nor carbapenemresistance.We speculated that ESBLs was the main mechanism in MDRKP,and ESBLs with the deletion of the outer membrane porin was the majorresistance mechanism in carbapenem resistance KP BSIs in our hospital.