Table 1.

Characteristics of the ESBL-producing Shigella strains under study.

Strain No.	Time of isolation	Serotype	Antibiotic resistance pattern*	Type of β-lactamase
1	June 12, 2009	S. sonnei	AMC-AM-NA-CAZ-TIC-CTX-CRO-CT-PIP-D-TE-S-SXT-CF	CMY-59
2	July 23, 2009	S. flexneri	AMC-AM-NA-CAZ-TIC-CTX-CRO-D-TE-S-SXT-C-CF	TEM-1, CTX-M-15
3	September 3, 2009	S. sonnei	AMC-AM-NA-CAZ-TOB-TIC-CTX-CRO-PIP-D-TE-S-SXT	TEM-1, CTX-M-15
4	November 10, 2009	S. sonnei	AMC-AM-CZA-TOB-TIC-CTX-CRO-D-TE-S-SXT-CF	TEM-1, CTX-M-15

^*AM: ampicillin, AMC: amoxycillin-clavulanic acid, C: chloramphenicol, CAZ: ceftazidime, CF: cephalothin, CRO: ceftriaxone, CT: ceftizoxime, CTX: cefotaxime, D: doxycycline, NA: nalidixic acid, PIP: piperacillin, S: streptomycin, SXT: trimethoprim-sulfamethoxazole, TE: tetracycline, TIC: ticarcillin, TOB: tobramycin