medical and biological sciences - Collegium Medicum - Uniwersytet ...

26Anna Budzyńska et al.Gram-dodatnie). Najczęściej izolowanym drobnoustrojembyła Klebsiella oxytoca. Wśród bakterii Gram-dodatnichdominowały gronkowce. Żaden ze szczepów Gramujemnychpałeczek nie wytwarzał beta-laktamaz o poszerzonymspektrum substratowym (ESβLs). Wśród pałeczekniefermentujących stwierdzono 2 szczepy oporne na imipenem.U prawie 90% szczepów gronkowców koagulazoujemnychwykryto oporność na beta-laktamazy (meticylinooporność).Wnioski. Pomimo że w badaniach wykazano niewielkiodsetek (4,6%) zakażeń odcewnikowych, cewnikitypu Broviac mogą stanowić poważne ryzyko bakteriemiiwśród dzieci z chorobami nowotworowymi. Prawidłowadiagnostyka mikrobiologiczna zakażeń odcewnikowychpowinna opierać się na analizie krwi pobranej równocześniez żyły i Broviaca.Key words: bacteriemia, catheter-related infection, BroviacSłowa kluczowe: bakteriemia, zakażenia odcewnikowe, BroviacINTRODUCTIONPatients with neoplastic diseases frequently requireplacement of a permanent external venous catheter orimplantation of a subcutaneous venous port (totallyimplanted device, TID) [1]. Introduction of treatmentmethods based on central venous catheters has manyadvantages, one of them being the diminished risk ofchemotherapy-related skin inflammation and reducedneed for venipuncture [2]. On the other hand, permanentcentral catheters have many disadvantages relatedto technical complications during their placement(catheter rupture; malfunction due to thrombosis at thetip or within the lumen; catheter migration), skin infectionat placement site, deep venous thrombosis orbloodstream infections (catheter-related bloodstreaminfections, CRBSI) [3, 4, 5, 6]. The development ofcatheter-related infection in pediatric patients withneoplastic diseases carries a high risk, primarily due toimpaired immune response [2].The aim of this study was an attempt to assess theincidence of catheter-related infections among thechildren treated in the Clinic of Pediatric Hematologyand Oncology of the dr A. Jurasz University Hospitalin Bydgoszcz, Poland as well as to perform an analysisof the microorganisms isolated from blood culturesharvested simultaneously from the Broviac catheterand a peripheral vein.MATERIAL AND METHODSThe study included 2941 blood samples obtainedfrom peripheral veins and Broviac catheters from 519patients of the Clinic of Pediatric Hematology andOncology of the dr A. Jurasz University Hospital inBydgoszcz, in the period of one and a half years. All ofthe samples were harvested according to recommendedprotocols and referred to the Dept. of Microbiology.The blood cultures were analyzed with the use ofthe BacT/Alert (bioMerieux) and Bactec (Becton Dickinson)automated systems. The samples indicated aspositive by the system were cultured on a set of media:Columbia Agar Base with 5% sheep blood, chocolateagar, Pyocyanosel agar, Sabouraud Agar (bioMerieux),MacConkey agar (Becton Dickinson). The Petri disheswere incubated at 37 o C for 24-48 hours in an oxygenatmosphere and in an atmosphere of 5% CO 2 (chocolateagar cultures). Colony morphology and the productionof bound and free coagulase were taken intoconsideration in identification of staphylococci. Speciesdetermination was based on biochemical features,with the use of the following assays: API 20 STREP,ID 32 STAPH, ID 32 E, ID 32 GN, API CORYNE(bioMerieux) which were read by using an ATB Expressioninstrument and ATB Expression software(version 2.8.8, bioMerieux).Antibiotic susceptibility was determined by theKirby-Bauer disk diffusion method, according to therecommendations of the CLSI (Clinical and LaboratoryStandards Institute) [7] and the National ReferenceCenter for Antimicrobial Susceptibility [8].A McFarland 0.5 inoculum strength was used on Mueller-HintonII Agar (Becton Dickinson). The antibiogramdishes were incubated for 18-20 hours at35 o C. Methicillin resistance of staphylococci was assessedwith the use of 1µg/ml oxacillin disks(bioMerieux). In order to detect extended-spectrumβ-lactamases, the two disk test was performed accordingto CLSI [7] and the National Reference Center forAntimicrobial Susceptibility [8] standards. The resultswere read after 18-20 hours of incubation at 35 o C. Thegrowth inhibition zones around the disks were interpretedaccording to the current CLSI tables [7].