Table 1.

Profiles of St. Louis isolates

StrainOrganismKirby-Bauer susceptibility zone diameters (mm)aPresence of β-lactamases with the following pIs:Possible identity of β-lactamase(s)
AMPAMCSAMPIPPTZCAZCTXATMFOXIPM5.45.66.17.68.79.0
114 K. pneumoniae 6181462281762327XXXTEM-1 or TEM-7; SHV-1, SHV-2, SHV-4, or SHV-7; chromosomal
117 K. pneumoniae 614861862261426XXXXTEM-1 or TEM-7; TEM-2, TEM-10, or TEM-26; SHV-1, SHV-2, SHV-4, SHV-6, or SHV-7; AmpC type
119 K. pneumoniae 61810623828132330XTEM-7 (?)
122 K. pneumoniae 616176251023131326XXXTEM-2, TEM-10, or TEM-26; SHV-1, SHV-2, SHV-4, SHV-6, or SHV-7; chromosomal
123 K. pneumoniae 6156618623101328XXXXTEM-1 or TEM-7; TEM-2, TEM-10, or TEM-26; SHV-1; AmpC type
125 K. pneumoniae 6161361862391727XTEM-10 or TEM-26
149 E. coli 61419625823142421XTEM-6, TEM-28, or TEM-43
154 E. coli 14201915252629321232XAmpC type
156 E. coli 6151562561461730XTEM-43
162 Klebsiella oxytoca 61614622623102327XXTEM-6, TEM-28, or TEM-43; chromosomal
164 K. pneumoniae 6171061981671527XTEM-7 (?)
166 E. coli 617186251328202125XTEM-10
171 K. pneumoniae 61617623923162324XXTEM-6, TEM-28, or TEM-43; chromosomal
179 K. pneumoniae 61516622624112226XTEM-6, TEM-28, or TEM-43
181 K. pneumoniae 61713621106141826XXXTEM-1 or TEM-7; SHV-1, SHV-2, SHV-4, or SHV-6; chromosomal
185 K. pneumoniae 61696181114112426XXXTEM-1 or TEM-7; SHV-1, SHV-2, SHV-4, SHV-6, or SHV-7; chromosomal
193 K. pneumoniae 620186241025172525XXTEM-6, TEM-28, or TEM-43; SHV-1
196 K. pneumoniae 61517622623132427XXTEM-6, TEM-28, or TEM-43; SHV-1
201 K. pneumoniae 61615622621151928XXTEM-6, TEM-28, or TEM-43; SHV-1, SHV-2, SHV-4, SHV-6, or SHV-7
  • a Disk diffusion tests were performed by a standard method, and the results were interpreted according to the guidelines of the National Committee for Clinical Laboratory Standards (17, 18). Abbreviations: AMP, ampicillin, AMC, amoxicillin clavulanic acid; SAM, ampicillin plus sulbactam; TIC, ticarcillin, TIM, ticarcillin plus clavulanic acid; PIP, piperacillin, PTZ, piperacillin plus tazobactam; CAZ, ceftazidime; CTX, cefotaxime; ATM, aztreonam, IMP, imipenem; FOX, cefoxitin.