RESUMO
Background: P.stuartii has emerged as an important nosocomial pathogen affecting primarily the hospitalized patients especially those with long term indwelling urinary catheters. Bladder colonization with those organisms provides a reservoir for outbreaks in long term care facilities. P.stuartii as an opportunistic pathogen is occasionally implicated in other types of hospital acquired infections, it could be isolated from infected wounds and burns. P. stuartii is of great clinical importance because of this organism's broad spectrum resistance to antibiotics, as clinical strains of P.stuartii are commonly resistant to aminopenicillins and early generation cephalosporins due to the production of an inherent Ambler class C cephlosporinase [AmpC], it can also acquires plasmide encoding class A Extended Spectrum Beta Lactamases [ESBLs]. Infection caused by ESBL producing P.stuarttii and its difficult treatment is a real emerging problem that should be really estimated in our locality. Aim : The aims of this study 'were to isolate P. stuartii from different sites of infection among patients in Mansoura University Hospitals [MUH], detect ESBL-producing Multi Durg Resistant [MDR] P. stuartii strains and confirm its role as nosocomial pathogen and to Identify of risk group patients and their clinical outcome. Methods: Urine, blood, sputum and -wound specimens were collected from patients clinically suspected of nosocomial infections. The collected specimens were cultivated on blood agar, MacConkey agar, chocolate agar and CLED agar for urine specimens. P.stuartii isolates were identified by colonial morphology, gram stained films, biochemical reactions and they were confirmed by API 20E strips. Double disk synergy test was performed to detect ESBLs producing isolates and MDR isolates were identified using the minimum inhibitory concentration [MIC] Etest strips. Finally the ESBLs producing MDR P.stuartii isolates were further characterized as regarded AmpC production using the modified three dimensional test and the presence of bla CTX-M gene by polymerase chain reaction. Results: P.stuartii was detected in 32 samples, representing 4.3% of all nosocomial pathogens. Most of the isolates were from catheterized urine samples and the most isolated co-pathogen was Proteus species. P.stuartii infections were significantly higher in patients with age more than 60 years [59.4%]. 53.1% of the isolated P. stuartii were ESBL-MDR isolates, 94% of them were AmpC producer and 65% of them were PCR positive for bla CTX-M gene. Conclusion: the clear role of P.stuartii as nosocomial pathogens, the high morbidity and mortality associated with their infections and their MDR character, make accurate detection is very important in order to offer successful treatment and ensure better patient outcome?