# name
Development and characterisation of highly antibiotic resistant
                Bartonella bacilliformis mutants

# metadata.dc.description.abstract[].value
The objective was to develop and characterise in vitro
                Bartonella bacilliformis antibiotic resistant mutants. Three B.
                bacilliformis strains were plated 35 or 40 times with
                azithromycin, chloramphenicol, ciprofloxacin or rifampicin
                discs. Resistance-stability was assessed performing 5 serial
                passages without antibiotic pressure. MICs were determined
                with/without Phe-Arg-beta-Napthylamide and artesunate. Target
                alterations were screened in the 23S rRNA, rplD, rplV, gyrA,
                gyrB, parC, parE and rpoB genes. Chloramphenicol and
                ciprofloxacin resistance were the most difficult and easiest
                (>37.3 and 10.6 passages) to be selected, respectively. All
                mutants but one selected with chloramphenicol achieved high
                resistance levels. All rifampicin, one azithromycin and one
                ciprofloxacin mutants did not totally revert when cultured
                without antibiotic pressure. Azithromycin resistance was related
                to L4 substitutions Gln-66 --> Lys or Gly-70 --> Arg; L4
                deletion Delta62-65 (Lys-Met-Tyr-Lys) or L22 insertion
                83::Val-Ser-Glu-Ala-His-Val-Gly-Lys-Ser; in two
                chloramphenicol-resistant mutants the 23S rRNA mutation G2372A
                was detected. GyrA Ala-91 --> Val and Asp-95 --> Gly and
                GyrB Glu474 --> Lys were detected in ciprofloxacin-resistant
                mutants. RpoB substitutions Gln-527 --> Arg, His-540 -->
                Tyr and Ser-545 --> Phe plus Ser-588 --> Tyr were detected
                in rifampicin-resistant mutants. In 5 mutants the effect of
                efflux pumps on resistance was observed. Antibiotic resistance
                was mainly related to target mutations and overexpression of
                efflux pumps, which might underlie microbiological failures
                during treatments.

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Reproducció del document publicat a:
                http://dx.doi.org/10.1038/srep33584

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Scientific Reports, 2016, vol. 6, num. 33584

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

# metadata.dc.title[].value
Development and characterisation of highly antibiotic resistant
                Bartonella bacilliformis mutants