RESUMO
The aim of this study was to evaluate the antimicrobial activity of imipenem plus amikacin or polymyxin B against six carbapenem-resistant P. aeruginosa by time-kill assay. Synergism was observed in two isolates for combinations with amikacin. For combinations with polymyxin B, synergism and antagonism also occurred in two isolates.
Assuntos
Amicacina/farmacologia , Anti-Infecciosos/farmacologia , Carbapenêmicos/farmacologia , Imipenem/farmacologia , Polimixina B/farmacologia , Infecções por Pseudomonas/microbiologia , Farmacorresistência Bacteriana , Sinergismo Farmacológico , Humanos , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/genéticaAssuntos
Escherichia coli/genética , Polimixinas , Animais , Brasil , Infecções por Escherichia coli , Humanos , Aves DomésticasRESUMO
Outbreaks associated with rapidly growing mycobacteria (RGM) have been increasingly reported worldwide, including in Brazil. Among the RGM, the Mycobacterium abscessus complex is the most pathogenic and related to multidrug resistance. The aim of this study was to evaluate the antimicrobial susceptibility and molecular profile of RGM isolates involved in new postsurgical infection outbreaks in Brazil since 2007. Of the 109 cases reported in the state of Rio Grande do Sul between 2007 and 2011, 43 (39â%) had confirmed mycobacterial growth in culture. Clinical isolates were obtained from biopsy specimens or abscess aspirates. PRA-hsp65 restriction pattern identified the isolates as M. abscessus type 2, and partial rpoB sequencing confirmed the identification as M. abscessus subsp. bolletii. All isolates were susceptible to amikacin and resistant to ciprofloxacin, doxycycline, sulfamethoxazole, moxifloxacin and tobramycin. Most isolates (72â%) were fully susceptible to cefoxitin but six isolates (14â%) were fully resistant to clarithromycin. The latter differed from the susceptibility profiles of the previously described BRA100 clone from other Brazilian regions. Nevertheless, pulsed-field gel electrophoresis analysis revealed that these isolates belonged to a single BRA100 clone. In conclusion, our study reports the persistence of an emergent single and highly resistant clone of M. abscessus subsp. bolletii for several years even after national implementation of infection control measures.
