Which family of ESBL enzymes is currently the most prevalent worldwide, particularly among Escherichia coli urinary isolates?

• A TEM
• B SHV
• C PER
• D CTX-M ✓

Explanation

CTX-M enzymes have displaced TEM and SHV as the dominant ESBL family globally, driven largely by the spread of CTX-M-15 in E. coli. They preferentially hydrolyse cefotaxime over ceftazidime, which explains isolates that look more resistant to cefotaxime than ceftazidime. TEM was the first described ESBL lineage, and SHV arose from the native Klebsiella penicillinase, but neither now predominates.

Reference: Koneman's Color Atlas and Textbook of Diagnostic Microbiology, 7th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

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