Stenotrophomonas Genome sequencing and assembly. Stenotrophomonas

Stenotrophomonas maltophilia is a Gram-negative, nonfermentative, environmental bacillus that has emerged as an important cause of MDR nosocomial infections in immunocompromised patients. Similar to our Pseudomonas project, Stenotrophomonas can confer resistance to carbapenem and extended spectrum beta lactamases via to intrinsic (chromosomally encoded) bla genes, L1 and L2. From a recent paper by the Bonomo lab (attached), "The L1 inducible metallo-β-lactamase (MBL) hydrolyzes carbapenems and other β-lactams, with the exception of the monobactam aztreonam (ATM), and is resistant to all clinically available β-lactamase inhibitors. The L2 β-lactamase is a chromosomally encoded, inducible cephalosporinase that confers resistance to extended-spectrum cephalosporins and ATM but can be inhibited by commercially available serine-β-lactamase inhibitors such as clavulanic acid." They have noticed several S. maltophilia isolates that are PCR negative for L1 and L2; therefore, it is imperative to identify the mechanism of resistance to the β-lactam-diazabicyclooctane combination. The goal of this study is to identify the mechanism of β-lactam-diazabicyclooctane resistance in S. maltophilia.