Table 1.

Comparison of MICs for OXA-type and TEM-type isolates of 91 S. flexneri isolates from Hong Kong and Shanghai

Antibiotic(s)OXA typea (n = 72)TEM typeb (n = 19)
MIC rangeMIC50MIC90MIC rangeMIC50MIC90
Ampicillin128–256128256512–≥2048256≥1,024
Cephalothin1–4442–64432
Cefuroxime1–4241–212
Cefotaxime≤0.015–0.060.030.060.03–0.060.030.06
Ceftazidime0.06–0.250.060.120.06–0.250.060.12
Ceftriaxone≤0.015–0.060.030.06≤0.015–0.060.030.06
Aztreonam0.03–0.060.030.060.03–0.250.030.25
Chloramphenicol1–≥2566412832–12864128
Sulfamethoxazole8–≥4096512≥4,0968–≥4,096512≥4,096
Streptomycin32–≥256128≥25664–≥256128≥256
Spectinomycin32–≥256≥256≥256≥256 ≥256≥256
Mercury chloride4–8484–≥648≥64
Trimethoprim0.5–≥128≥128≥1280.25–≥128≥128≥128
Tetracycline64–≥512128≥51264–≥512128≥512
Nalidixic acid2–≥64≥64≥642–≥642≥64
Ciprofloxacin0.0075–0.250.00750.060.03–10.030.03
Ofloxacin0.03–20.030.03 0.030.030.03
Gentamicin1–2121–222
Amikacin2–8482–848
Tobramycin0.5–2221–222
Amoxicillin-clavulante16/8–32/1616/832/168/4–32/168/432/16
Ampicillin-sulbactam16/8–32/1616/832/168/4–≥128/6416/832/16
  • a pI, approximately 7.4. MIC50 and MIC90, MICs for 50 and 90% of isolates, respectively. All values are in micrograms per milliliter.

  • b pI, approximately 5.4.