Diversity of carbapenemases in clinical isolates: The emergence of bla in Bangladesh.

Global emergence and dissemination of carbapenemases are clinically threatening, notably in countries with endemic bla. To analyze the extent of carbapenemases in Bangladesh, 71 isolates were collected from 7 different clinical sources: wound swab (n = 38), pus (n = 13), urine (n = 9), blood (n = 4), tracheal aspirate (n = 3), pleural fluid (n = 1) and vaginal swab (n = 3) from Dhaka Medical College Hospital, Bangladesh. Among the isolates, 25 were resistant to at least one of the three carbapenems (imipenem, meropenem and doripenem), including 15 being resistant to all. These resistant isolates were identified as Pseudomonas aeruginosa, Acinetobacter baumannii, Klebsiella pneumoniae, P. hibiscicola, Proteus mirabilis, Providencia stuartii and Citrobacter sedlakii. Carbapenemase detection among these 25 isolates varied in individual phenotypic assays (83% in Modified Hodge Test, 50% in Combined Disk Test for Metallo-β-lactamase prediction) as compared with the genotypes observed (96% prevalence of various carbapenemases including bla, bla, bla). bla was the most prevalent gene (84%) followed by bla (72%). Coexistence of multiple gene combination such as bla+bla+bla was prevalent (48%). Harborage of bla (n = 1) was characterized for the first time, while bla (n = 5) was reported contemporarily with a recent study in Bangladesh. Presence of plasmids (64%) and integron class 1 (100%) signifies the transferable potential of resistant traits. The emergence of such new variants along with the presence of the mobile genetic elements demands strict surveillance and combating strategies.