Hugh 1981 Xanthomonas maltophilia (Hugh 1981) Swings et al. 1983 Pseudomonas hibiscicola Moniz 1963 Pseudomonas beteli corrig. (Ragunathan 1928) Savulescu 1947 Stenotrophomonas maltophilia is an aerobic , nonfermentative , Gram-negative bacterium . It is an uncommon bacterium and human infection is difficult to treat. [ 1 ] Initially classified as Pseudomonas