Which beta-lactamase enzyme family is currently the most widespread ESBL type among clinical isolates of Enterobacterales worldwide?
- A CTX-M-type ✓
- B SHV-type
- C TEM-type
- D PER-type
Correct answer: A. CTX-M-type
Explanation
CTX-M enzymes have displaced TEM and SHV derivatives as the dominant ESBL family globally, including in India. They hydrolyse cefotaxime far more efficiently than ceftazidime, so isolates often show a cefotaxime MIC much higher than the ceftazidime MIC. TEM and SHV were the classic ESBLs described earlier but are now less prevalent, and PER-type enzymes are rare regional variants rather than a global dominant group.
Reference: Ananthanarayan and Paniker's Textbook of Microbiology, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
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