ObjetivosCaracterizar los niveles y mecanismos de resistencia a β-lactámicos, quinolonas y macrólidos en 62 aislamientos de Escherichia coli causantes de bacteriemia en niños peruanos.MétodosSe determinaron las concentraciones inhibitorias mínimas (CIM) de ciprofloxacino, ácido nalidíxico (NAL) y azitromicina en presencia y ausencia de Phe-Arg-β-naftilamida. También se estableció la susceptibilidad a otros 14 agentes antimicrobianos. Se identificaron las β-lactamasas de espectro extendido (ESBL) y se determinaron las mutaciones en gyrA y parC, así como la presencia de mecanismos transferibles de resistencia a quinolonas (TMQR) y macrólidos (TMMR).ResultadosCincuenta aislados (80,6%) eran multirresistentes. Se observaron altas proporciones de resistencia a la ampicilina (93,5%), al NAL (66,1%) y al trimetoprim/sulfametoxazol (66,1%). Ningún aislado mostró resistencia a los...

From its introduction in 1952 onwards, the clinical use of macrolides has been steadily increasing, both in human and veterinary medicine. Although initially designed to the treatment of Gram-positive microorganisms, this antimicrobial family has also been used to treat specific Gram-negative bacteria. Some of them, as azithromycin, are considered in the armamentarium against Enterobacteriaceae infections. However, the facility that this bacterial genus has to gain or develop mechanisms of antibiotic resistance may compromise the future usefulness of these antibiotics to fight against Enterobacteriaceae infections. The present review is focused on the mechanisms of macrolide resistance, currently described in Enterobacteriaceae.

This study aimed to identify new B. bacilliformis antigenic candidates that could lead to a new diagnostic tool able to be implemented in endemic rural areas. RT-PCR and the high levels of positivity for specific ELISAs demonstrate high levels of B. bacilliformis exposure and asymptomatic carriers among inhabitants. The new antigens identified might be used as a new rapid diagnostic tool to diagnose acute Carrion’s disease and identify asymptomatic carriers.