title: Microevolution of cytochrome bd oxidase in Staphylococci and its implication in resistance to respiratory toxins released by Pseudomonas.
abstract: Pseudomonas aeruginosa and Staphylococcus aureus are opportunistic pathogens and frequently coinfect the lungs of cystic fibrosis patients. P. aeruginosa secretes an arsenal of small respiratory inhibitors, like pyocyanin, hydrogen cyanide, or quinoline N-oxides, that may act against the commensal flora as well as host cells. Here, we show that with respect to their susceptibility to these respiratory inhibitors, staphylococcal species can be divided into two groups: the sensitive group, comprised of pathogenic species such as S. aureus and S. epidermidis, and the resistant group, represented by nonpathogenic species such as S. carnosus, S. piscifermentans, and S. gallinarum. The resistance in the latter group of species was due to cydAB genes that encode a pyocyanin- and cyanide-insensitive cytochrome bd quinol oxidase. By exchanging cydB in S. aureus with the S. carnosus-specific cydB, we could demonstrate that CydB determines resistance. The resistant or sensitive phenotype was based on structural alterations in CydB, which is part of CydAB, the cytochrome bd quinol oxidase. CydB represents a prime example of both microevolution and the asymmetric pattern of evolutionary change.
authors.affiliation: Microbial Genetics, University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Lalitha
authors.initials: L
authors.lastname: Voggu
authors.forename: Steffen
authors.initials: S
authors.lastname: Schlag
authors.forename: Raja
authors.initials: R
authors.lastname: Biswas
authors.forename: Ralf
authors.initials: R
authors.lastname: Rosenstein
authors.forename: Christian
authors.initials: C
authors.lastname: Rausch
authors.forename: Friedrich
authors.initials: F
authors.lastname: Götz
mesh_terms: D000595:Amino Acid Sequence; D000898:Antibiosis; D001426:Bacterial Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D001427:Bacterial Toxins / Q000378:metabolism / Q000494:pharmacology*; D017077:Culture Media, Conditioned / Q000494:pharmacology; D003580:Cytochromes / Q000235:genetics* / Q000378:metabolism; D024881:Drug Resistance, Bacterial / Q000235:genetics; D019143:Evolution, Molecular; D006899:Mixed Function Oxygenases / Q000378:metabolism / Q000494:pharmacology; D008969:Molecular Sequence Data; D010088:Oxidoreductases / Q000235:genetics* / Q000378:metabolism; D010802:Phylogeny; D011550:Pseudomonas aeruginosa / Q000276:immunology / Q000378:metabolism*; D011710:Pyocyanine / Q000378:metabolism / Q000494:pharmacology; D016415:Sequence Alignment; D040141:Staphylococcaceae / Q000187:drug effects* / Q000201:enzymology* / Q000276:immunology
chemical_list: D001426:Bacterial Proteins; D001427:Bacterial Toxins; D017077:Culture Media, Conditioned; D003580:Cytochromes; C083459:pyocynase, Pseudomonas aeruginosa; D011710:Pyocyanine; D006899:Mixed Function Oxygenases; D010088:Oxidoreductases; C020094:duroquinol oxidase; C436954:cyanide oxidase