DELIA MIRA BERCEANU VADUVA, DANA EMILIA VELIMIROVICI, MARCEL MIHAI BERCEANU VADUVA, LIVIA STANGA, HORATIU PETRESCU, MARIA RADA, DANIELA CIPU, BIANCA MANUELA BERCEANU VADUVA, MATILDA RADULESCU PHENOTYPIC STUDY AND SENSITIVITY TO ANTI-INFECTIVE CHEMOTHERAPY OF BACTERIAL STRAINS ISOLATED FROM CUTANEOUS-MUCOSAL INFECTIONS Skin- and mucosal infections, especially purulent, can often cause diagnostic and treatment problems. Therefore, we intend to conduct a microbiological study of isolated bacterial strains from ambulatory patients with various cutaneous-mucosal infections. In isolated strains we determined the sensitivity to antibiotics and we established the phenotypes of resistance in which they fall. We took in account 98 strains isolated by a private laboratory in Timisoara between January 2016 and December 2017. After bacterial identification, sensitivity testing to antibiotics was realized using Kirby-Bauer disc diffusion according to the CLSI standard. Antibiogram was performed for all strains except for Streptococcus pyogenes. By interpreting the antibiograms, the phenotypes of resistance were determined. Most infections were caused by Staphylococcus aureus. In order of frequency following strains were isolated: Staphylococcus aureus (75.52%), Streptococcus pyogenes (11.22%), Pseudomonas aeruginosa (7.14%), E. coli (4.08%) ’i Enterobacter spp. (2.04%). S. aureus strains were resistant to penicillin in 94.60% of cases. We observed a higher sensitivity to oxacillin (87.84%), tobramycin (86.49%), gentamycin (87.84%), ciprofloxacin (83.78%) and clindamycin (89.20%). Most strains of S. aureus were of phenotype Peni-R Meti-S (82.44%). 12.16% were of phenotype Peni-R Meti-R (MRSA) and only 5.40% were sensitive to betalactams (Peni-S Meti-S). Gram-negative bacilli strains (Pseudomonas aeruginosa, E. coli, Enterobacter spp.) were less resistant, all being wild strains. Determining antibiotic resistance phenotypes is necessary in order to be able to make the right decision when choosing anti-infectious treatment, but also to prevent the selection of multi-resistant bacterial strains. The presence of MRSA at a rate of 12.16% is an alarm signal because the MRSA strains are multi-resistant to antibiotics with cross-resistance to the betalactams. Resistance usualy extends also to other classes of antibiotics. For a correct diagnosis and treatment, the results of the bacteriological testing need to be corroborated with the clinical signs.