Contemporary activity of colistin and polymyxin B against a worldwide collection of Gram-negative pathogens: results from the SENTRY Antimicrobial Surveillance Program (2006-09)

Although the polymyxins showed excellent in vitro activity against the vast majority of Gram-negative bacilli evaluated, a trend to greater resistance was observed in the Asia-Pacific and Latin American regions. Therefore, the clinical use of polymyxins must be cautious and surveillance monitored.