Stenotrophomonas maltophilia (
S. maltophilia), a newly emerging global opportunistic Gram-negative pathogen, exists widely in nature and hospitals [
1]. It can be isolated from soil, plant roots, and aqueous-associated sources, such as water treatment and distribution systems, tap water, and bottled water [
2].
S. maltophilia strains of both clinical and environmental origin have been reported to adhere to abiotic surfaces and form bacterial biofilm [
3,
4]. Besides,
S. maltophilia can adhere to mouse tracheal mucus and thus cause respiratory tract infections [
5]. As the third most frequently isolated nonfermentative Gram-negative bacilli following
Pesudomonas aeruginosa and
Acinetobacter species [
6],
S. maltophilia is also a newly emerging multiple-drug-resistant organism [
2].
S. maltophilia can cause infections in multiple organs and tissues, such as the respiratory tract, biliary and urinary tract, skin, bone and joint, heart, brain, eyes, and soft tissues [
7‐
9]. Risk factors for
S. maltophilia-associated infections include immunosuppression, cancer, indwelling devices, mechanical ventilation, and broad spectrum antimicrobial therapy [
10,
11]. The mortality rate of
S. maltophilia-associated infection ranges from 14 to 69% in patients with bacteremia [
12].
S. maltophilia has been found to show resistance to a broad array of antibiotics, such as trimethoprim-sulfamethoxazole (TMP-SMX), β-lactam antibiotics, macrolides, fluoroquinolones, cephalosporins, aminoglycosides, chloramphenicol, carbapenems, tetracyclines, and polymyxins [
13‐
15]. Thus, it is becoming increasingly challenging for physicians to use conventional therapies to treat
S. maltophilia-associated infections effectively. Novel therapeutic or preventive approaches targeting
S. maltophilia-associated infections are greatly needed. Currently, vaccines or antibody based treatments have not been developed for
S. maltophilia-associated infections.
Bacterial outer membrane proteins (Omps) play key roles in bacterial survival and multiplication in host systems. Omps of
Aeromonas salmonicida have been found to regulate the adherence and serum and bile salt resistance of the bacteria [
16]. Because many bacterial Omps can be easily recognized by the host immune system as foreign substances so to initiate host immune defense mechanism against the bacterial infection [
17‐
20], they could be potential vaccine candidates against the infection. Immunoproteomic technology is now allowing screening immunogenic candidate proteins rapidly and effectively. In the current study, we used immunoproteomic technology to identify immunogenic Omps of
S. maltophilia, developed antibodies against the Omps, and tested the effects of immunization with recombinant Omps on tissue bacterial loads in a mouse model of
S. maltophilia infection.