“…Such variant strains with PB-sensitivity indices are shown to be replacing the wild type or proto-typical resistant El Tor V. cholerae strains [71] . Some studies reported a co-resistance mechanism of doxycycline and a member of the lipopeptide antibiotic (colistin) [72] . From the foregoing, such reports suggest that the status of polymyxin resistance and sensitivity as a biotyping scheme is questionable.…”