PMID- 3263833
OWN - NLM
STAT- MEDLINE
DCOM- 19881206
LR  - 20210526
IS  - 0066-4804 (Print)
IS  - 1098-6596 (Electronic)
IS  - 0066-4804 (Linking)
VI  - 32
IP  - 7
DP  - 1988 Jul
TI  - Simple assay of beta-lactamase with agar medium containing a chromogenic 
      cephalosporin, pyridinium-2-azo-p-dimethylaniline chromophore (PADAC).
PG  - 1040-5
AB  - A new beta-lactamase assay method with agar plates containing 
      pyridinium-2-azo-p-dimethylaniline chromophore (PADAC) (50 microM), a 
      beta-lactamase-labile, chromogenic cephalosporin, was examined. On the PADAC 
      plates inoculated with beta-lactamase-producing gram-negative bacteria (10(4) CFU 
      per spot) and incubated at 37 degrees C, a yellow zone showing hydrolysis of 
      PADAC by beta-lactamase was formed around the colony. The zone diameter increased 
      with incubation time. Examination with Enterobacter cloacae GN7471 revealed that 
      beta-lactamase activity was present in the agar around the colony, decreasing 
      exponentially with increasing distance from the colonial margin; this suggests 
      that the PADAC hydrolysis zone is formed by an extracellular enzyme. At 18 h, 
      significant correlations were obtained between the zone diameters of the 10 
      species (clinical isolates) examined and their periplasmic beta-lactamase 
      activities determined spectrophotometrically. The addition of clavulanic acid 
      (0.5 to 10 micrograms/ml) inhibited zone formation on the PADAC plates inoculated 
      with type IIIa, Va, Vb, PSE-1, and Ic beta-lactamase producers. When the clinical 
      isolates were tested on plates with clavulanic acid (2 micrograms/ml), inhibition 
      was observed in 41 to 58% of the Escherichia coli, Serratia marcescens, and 
      Pseudomonas aeruginosa isolates and in all isolates of Klebsiella pneumoniae, 
      Klebsiella oxytoca, and Proteus vulgaris. Thus, the use of the inhibitor made it 
      possible to detect penicillinase or type Ic cephalosporinase producers. These 
      results proved that the PADAC plate might be a useful tool permitting easy, 
      semiquantitative determination of beta-lactamase activity.
FAU - Kobayashi, S
AU  - Kobayashi S
AD  - Pharma Research Laboratories, Hoechst Japan Ltd., Saitama, Japan.
FAU - Arai, S
AU  - Arai S
FAU - Hayashi, S
AU  - Hayashi S
FAU - Sakaguchi, T
AU  - Sakaguchi T
LA  - eng
PT  - Journal Article
PL  - United States
TA  - Antimicrob Agents Chemother
JT  - Antimicrobial agents and chemotherapy
JID - 0315061
RN  - 0 (Cephalosporins)
RN  - 0 (Chromogenic Compounds)
RN  - 0 (Clavulanic Acids)
RN  - 0 (beta-Lactamase Inhibitors)
RN  - 23521W1S24 (Clavulanic Acid)
RN  - 77449-91-3 (pyridine-2-azo-4-dimethylaniline cephalosporin)
RN  - 9002-18-0 (Agar)
RN  - EC 3.5.2.6 (beta-Lactamases)
SB  - IM
MH  - Agar
MH  - *Cephalosporins
MH  - *Chromogenic Compounds
MH  - Clavulanic Acid
MH  - Clavulanic Acids/pharmacology
MH  - Enterobacter/enzymology
MH  - Hydrolysis
MH  - beta-Lactamase Inhibitors
MH  - beta-Lactamases/*analysis
PMC - PMC172340
EDAT- 1988/07/01 00:00
MHDA- 1988/07/01 00:01
PMCR- 1988/07/01
CRDT- 1988/07/01 00:00
PHST- 1988/07/01 00:00 [pubmed]
PHST- 1988/07/01 00:01 [medline]
PHST- 1988/07/01 00:00 [entrez]
PHST- 1988/07/01 00:00 [pmc-release]
AID - 10.1128/AAC.32.7.1040 [doi]
PST - ppublish
SO  - Antimicrob Agents Chemother. 1988 Jul;32(7):1040-5. doi: 10.1128/AAC.32.7.1040.