Transferable mechanisms of quinolone resistance are more frequent among enterotoxigenic Escherichia coli isolates displaying low-level quinolone resistance

@#This study analysed the mechanisms of quinolone resistance among enterotoxigenic Escherichia coli (ETEC) in a periurban area of Lima, Peru. The susceptibility to nalidixic acid and ciprofloxacin, the role of Phe-Arg-b-Naphtylamyde inhibitable-(PAbN) efflux pumps, the presence of mutations in gyrA and parC as well as the presence of aac(6’)Ib-cr, qepA, qnrA, qnrB, qnrC, qnrD, qnrVC and oqxAB were determined in 31 ETEC from previous case/control studies of children’s diarrhoea. Discordances between disk diffusion, with all isolates showing intermediate or fully resistance to nalidixic acid, and minimal inhibitory concentration (MIC), with 7 isolates being below considered resistance breakpoint, were observed. Twenty-one isolates possessed gyrA mutations (19 S83L, 2 S83A). AAC(6’) Ib-cr, QnrS, QnrB and QepA were found in 7, 6, 2 and 1 isolates respectively, with 3 isolates presenting 2 transferable mechanisms of quinolone resistance (TMQR) concomitantly. TMQR were more frequent among isolates with MIC to nalidixic acid ranging from 2 to 16 mg/L (p=0.03), while gyrA mutations were more frequent among isolates with nalidixic acid MIC > 128 mg/L (p=0.0002). In summary, the mechanisms of quinolone resistance present in ETEC isolates in Peru have been described. Differences in the prevalence of underlying mechanisms associated with final MIC levels were observed. The results suggest two different evolutive strategies to survive in the presence of quinolones related to specific bacterial genetic background.

Intubación orotraqueal transmilohiodea en cirugía maxilofacial / Trans-mylohyoid orotracheal intubation in maxilofacial surgery

Los pacientes con alteraciones en las relaciones intermaxilares para la intubación y el mantenimiento del tubo endotraqueal durante la cirugía craneomaxilofacial. La fijación del tubo nasotraqueal puede ser seccionado accidentalmente en el momento de las osteomías. Se describe la técnica de pasaje transmilohiodeodel tubo orotraqueal y se detallan sus indicaciones y resultados. Entre Mayo de 1995 y Abril de 1997 se utilizó el método en diez pacientes con resultados favorables. Se indica como alternativa de intubación el uso de la vía orotraqueal, con abocamiento a la piel a través del músculo milohioideo, con el fin de obtener un mejor espacio quirúrgico y evotar los riesgos de obstrucción, extubación accidental y sección de la cánula endotraqueal, sin tener que recurrir a una traqueostomía