Abstract
<jats:p>Introduction. Sphingomonas paucimobilis is a Gram-negative, non-fermenting bacterium widely distributed in the natural environment and known for its resistance to disinfectants commonly used in healthcare settings. Human infections have been reported sporadically in both immunocompromised and immunocompetent individuals. However, data regarding the antimicrobial susceptibility patterns of this microorganism remain limited and fragmented in the literature. Objective: To determine the antibiotic susceptibility profile of clinical strains of S. paucimobilis isolated from the pharynx of children with recurrent tonsillitis and to identify antimicrobial agents suitable for empirical therapy. Materials and methods. A bacteriological approach was employed. Quantitative cultures were performed using the sector plating method on Columbia agar (bioMérieux, France). Final identification of pure isolates was carried out using the automated VITEK® 2 Compact system (bioMérieux, France). Antimicrobial susceptibility testing was performed using the standardized disk diffusion method according to the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines on Mueller–Hinton agar. Due to the slow growth characteristics of S. paucimobilis, inhibition zones were measured after 72 hours of incubation. Results. Three isolates of S. paucimobilis were recovered from nasopharyngeal specimens of five children, in clinically significant concentrations. Overall, the isolates demonstrated susceptibility to most tested antibiotics. The greatest variability in susceptibility was observed for the combination drug co-trimoxazole, with inhibition zone diameters differing by 1.7-fold between isolates 1 and 3. The lowest susceptibility was recorded for aztreonam, with inhibition zone diameters measuring less than 11 mm. Conclusions. For empirical treatment of infections caused by S. paucimobilis, β-lactam antibiotics combined with clavulanic acid, piperacillin–tazobactam, and carbapenems appear to be the most appropriate options. Rifampicin may be considered in cases of resistance to other antimicrobial agents.</jats:p>