# name
Azithromycin resistance levels and mechanisms in Escherichia
                coli

# metadata.dc.description.abstract[].value
Despite azithromycin being used in some countries to
                treat infections caused by Gram-negative pathogens, no
                resistance breakpoint for Escherichia coli exists. The aim of
                this study was to analyse the levels and mechanisms of
                azithromycin resistance in E. coli. The presence of chromosomal
                (rplD, rplV and 23S rRNA) mutations, 10 macrolide resistance
                genes (MRGs) and efflux pump overexpression was determined in
                343 E. coli isolates. Overall, 89 (25.9%) isolates had
                MICs\xE2\x80\x89\xE2\x89\xA5\xE2\x80\x8932\xE2\x80\x89mg/L to
                azithromycin, decreasing to 42 (12.2%) when assayed in the
                presence of Phe-Arg-\xCE\xB2-Napthylamide, with 35 of these 42
                possessing at least one MRG. Efflux pumps played a role in
                azithromycin resistance affecting the Minimal Inhibitory
                Concentration (MIC) levels of 91.2% isolates whereas chromosomal
                alterations seem to have a minimal role. At least one MRG was
                found in 22.7% of the isolates with mph(A) being the most
                commonly found gene. The mph(A) gene plays the main role in the
                development of azithromycin resistance and 93% of the
                mph(A)-carrying isolates showed a MIC of 32\xE2\x80\x89mg/L. In
                the absence of a specific resistance breakpoint our results
                suggest a MIC of 32\xE2\x80\x89mg/L to be considered in order to
                detect isolates carrying mechanisms able to confer azithromycin
                resistance.

# metadata.dc.source[].value
Articles publicats en revistes (ISGlobal)

# metadata.dc.title[].value
Azithromycin resistance levels and mechanisms in Escherichia
                coli