T
he co-occurrence of L1 and AmpR-L2 with
blaNDM-1 gene with an upstream 250-bp promoter was detected in a clinical isolate of
Stenotrophomonas maltophilia DCPS-01, which was resistant to all 尾-lactams and sensitive only to colistin and fluoroquinolones. To investigate expression of resistance genes and t
he molecular mechanisms of bacteria resistance to carbapenems, proteomic profiles of t
he isolate was passaged with and without t
he drug by using 2D-PAGE. T
he results showed that 33 genes exhibiting a 鈮?-fold change were identified as candidates that may
help
S. maltophilia survive drug selection. Strikingly, L1 was expressed more highly in cells grown with imipenem, and t
he abundant NDM-1 furt
her increased, while very little L2 was detected even following induction. Specific activities for 尾-lactamase revealed that L2 remained at constitutive low levels (10.6 U/mg), while L1 and NDM-1 showed clear activity (69.8 U/mg). Our data support that imipenem could specifically and reversibly induce L1 and NDM-1, which toget
her played key roles in drug resistance in DCPS-01. Although NDM-1 mediated resistance to carbapenems has been found in very few cases, to our knowledge, this is t
he first proteomics research of
S. maltophilia with NDM-1, giving very broad-spectrum antibiotic resistance profiles.
Keywords:
Stenotrophomonas maltophilia DCPS-01; 尾-lactams resistance; co-occurrence; blaNDM-1; L1 and L2 metallo-尾-lactamase