PMID- 8243483
OWN - NLM
STAT- MEDLINE
DCOM- 19940106
LR  - 20190830
IS  - 0934-9723 (Print)
IS  - 0934-9723 (Linking)
VI  - 12
IP  - 9
DP  - 1993 Sep
TI  - Survey of clinical isolates of Staphylococcus aureus for borderline 
      susceptibility to antistaphylococcal penicillins.
PG  - 677-82
AB  - On the basis of the MICs of methicillin and oxacillin, 975 clinical isolates of 
      Staphylococcus aureus were categorized as having resistance, borderline 
      susceptibility or full susceptibility to penicillinase-resistant penicillins 
      (PRPs). The borderline phenotype accounted for 122 isolates (12.5%), whereas 562 
      isolates were fully susceptible and 290 resistant; one remaining isolate had 
      resistance to methicillin and borderline susceptibility to oxacillin. Reductions 
      in the MICs of methicillin and oxacillin in the presence of sulbactam were 
      greater in strains with borderline PRP susceptibility than in fully susceptible 
      or resistant isolates. Over 99% of fully PRP-susceptible strains, 93% with 
      borderline susceptibility and 71% of resistant strains were susceptible to 
      ampicillin/sulbactam. The production of beta-lactamase, assayed in all strains 
      using nitrocefin as substrate, could be detected without prior induction in 729 
      strains and after induction only in another 156 strains. With only two 
      exceptions, the beta-lactamase negative strains were part of the fully 
      PRP-susceptible group of organisms (88 of 562 isolates). Among the borderline 
      isolates, strong beta-lactamase reactions were encountered with particular 
      frequency, but not in all strains and not exclusively in borderline strains. 
      Although associated with the majority of borderline strains, beta-lactamase 
      hyperproduction thus did not appear to be an essential feature of the borderline 
      phenotype. The results obtained may have implications for laboratory and clinical 
      medicine, also in the light of recent findings suggesting that other mechanisms 
      besides beta-lactamase hyperproduction may account for borderline susceptibility 
      to PRPs.
FAU - Varaldo, P E
AU  - Varaldo PE
AD  - Institute of Microbiology, University of Ancona Medical School, Italy.
FAU - Montanari, M P
AU  - Montanari MP
FAU - Biavasco, F
AU  - Biavasco F
FAU - Manso, E
AU  - Manso E
FAU - Ripa, S
AU  - Ripa S
FAU - Santacroce, F
AU  - Santacroce F
LA  - eng
PT  - Journal Article
PT  - Research Support, Non-U.S. Gov't
PL  - Germany
TA  - Eur J Clin Microbiol Infect Dis
JT  - European journal of clinical microbiology & infectious diseases : official 
      publication of the European Society of Clinical Microbiology
JID - 8804297
RN  - 65DT0ML581 (sultamicillin)
RN  - 7C782967RD (Ampicillin)
RN  - EC 3.5.2.- (Penicillinase)
RN  - EC 3.5.2.6 (beta-Lactamases)
RN  - Q91FH1328A (Methicillin)
RN  - S4TF6I2330 (Sulbactam)
RN  - UH95VD7V76 (Oxacillin)
SB  - IM
MH  - Ampicillin/pharmacology
MH  - Ampicillin Resistance
MH  - Drug Therapy, Combination/pharmacology
MH  - Humans
MH  - Methicillin/*pharmacology
MH  - Methicillin Resistance
MH  - Microbial Sensitivity Tests
MH  - Oxacillin/*pharmacology
MH  - *Penicillin Resistance
MH  - Penicillinase/*metabolism
MH  - Staphylococcal Infections/microbiology
MH  - Staphylococcus aureus/*drug effects/enzymology
MH  - Sulbactam/pharmacology
MH  - beta-Lactamases/biosynthesis
EDAT- 1993/09/01 00:00
MHDA- 1993/09/01 00:01
CRDT- 1993/09/01 00:00
PHST- 1993/09/01 00:00 [pubmed]
PHST- 1993/09/01 00:01 [medline]
PHST- 1993/09/01 00:00 [entrez]
AID - 10.1007/BF02009379 [doi]
PST - ppublish
SO  - Eur J Clin Microbiol Infect Dis. 1993 Sep;12(9):677-82. doi: 10.1007/BF02009379.