SIMONA CONSTANTINESCU, CLAUDIA ELENA PLESCA, PARASCHIVA POSTOLACHE, MIHAELA CATALINA LUCA ANTIBIORESISTANCE OF MICROBIAL STRAINS IMPLICATED IN THE ETIOLOGY OF SEPSIS WITH ORO-MAXILLOFACIAL PORTAL OF ENTRY Grigore T Popa University of Medicine and Pharmacy, Microbiology Department, 16 Universitatii Str., 700115, Timisoara, Romania 2 Grigore T Popa University of Medicine and Pharmacy, Infectious Diseases Department, 16 Universitatii Str., 700115, Timisoara, Romania
Methicillin-resistance phenomenon regarding Staphylococcus aureus which is often met as etiologic agent of severe systemic infections with oral-maxillofacial portal of entry imposes the first-line therapeutic schemes readjustment in patients with significant risk factors. Minimum inhibitory concentration (MIC) determination for every isolated S.aureus strain is useful for the antibiotherapy guiding, in order to choose the appropriate antimicrobial substances and to avoid the selection of resistant mutants. There have been studied and tested 9036 bacterial strains isolated from patients hospitalized in the Sf.Spiridon Emergency County Hospital between 2013-2016. Minimum inhibitory concentrations (MIC), MIC 50 and MIC 90 values were determined for the following antibiotics: Penycilline, Erithromycin, Oxacylline, Tetracycline, Gentamycin, Tobramycine, Kanamycin, Ryfampicyn, Trimethoprim-Sulfamethoxazole, Ofloxacine, Ciprofloxacine and Vancomycin.The classification of each identified bacterial strain into sensitive or resistant was accomplished according to the breakpoints recommended by CLSI 2016 (Clinical and Laboratory Standard Institute). We considered intermediately susceptible isolates as being resistant. S.aureus antibioresistance was high to tetracycline, erythromycin and kanamycin, with elevated MIC 90 values (64µg). The rate of resistance to penicillin in the case of S.aureus was 94.7%. The lowest MIC values regarding Pseudomonas aeruginosa were for imipenem, meropenem and colistin and the highest ones for piperacillin-tazobactam, ceftazidime and amikacin. Third generation cephalosporins demonstrated their inefficiency in the staphylococcal infections’ treatment as a consequence of an increasing resistance to this category of betalactams. Vancomycin remains a saving in-hospital therapeutic option in the case of MRSA implication, next to teicoplanin and linezolid.