Carbapenem-resistant Klebsiella pneumoniae (CRKP) is a critical threat in ICU settings. The most common mechanism of carbapenem resistance in K. pneumoniae in India is production of which enzyme?
- A NDM-1 (New Delhi metallo-beta-lactamase) — a class B metallo-beta-lactamase ✓
- B KPC-2 (K. pneumoniae carbapenemase) — a class A serine carbapenemase
- C OXA-48 (oxacillinase-48) — a class D serine carbapenemase
- D VIM-1 (Verona integron-encoded metallo-beta-lactamase) — a class B enzyme
Explanation
India is the global epicentre of NDM-1-producing Enterobacteriaceae. NDM-1 (New Delhi metallo-beta-lactamase-1) is a class B metallo-beta-lactamase (requires zinc ions as cofactor) that hydrolyses virtually all beta-lactams including carbapenems, but not aztreonam (a monobactam). NDM-1 was first described in a K. pneumoniae isolate from a patient who had been hospitalised in India. The blaNDM gene is located on highly transmissible plasmids, facilitating horizontal spread. Treatment options for NDM producers are limited: colistin, polymyxin B, tigecycline, fosfomycin, or ceftazidime-avibactam + aztreonam combination. KPC is predominant in the USA; OXA-48 in Europe and Turkey.
Reference: Ananthanarayan & Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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