Featured organism: pathogen special: Vibrio cholerae, Pseudomonas aeruginosa and Xylella fastidiosa.

One could almost say that it is the latest fashion to sequence a bacterial genome. However, this would belittle the efforts of those working on these important organisms, whose data will greatly help those working on the prevention of disease in the fields of medicine and agriculture. In this feature we present a guided tour of the latest additions to the 'sequenced microbes' club. Vibrio cholerae is the causative agent of cholera, which is still a threat in countries with poor sanitation and unsafe drinking water. Pseudomonas aeruginosa is responsible for a large proportion of opportunistic human infections, typically infecting those with compromised immune systems, particularly cystic fibrosis patients, those patients on respirators and burn victims. Xylella fastidiosa is a plant pathogen that attacks citrus fruits by blocking the xylem, resulting in juiceless fruits of no commercial value. Copyright 2000 John Wiley & Sons, Ltd.