[Enterobacter cloacae and E. aerogenes septicemia: emergence of resistant variants (derepressed cephalosporinase) during treatment with third-generation cephalosporins].
From three patients hospitalised in intensive care units with Enterobacter septicaemia (two cases with E. cloacae, and one with E. aerogenes), cefotaxime therapy, alone or in combination with an aminoglycoside, selected variants (R) with increased resistance to beta-lactam antibiotics. The cross-resistance extended to all the beta-lactam antibiotics tested, penicillins and cephalosporins, including third-generation cephalosporins. The crude extracts of uninduced cultures of R variants showed high beta-lactamase activity and of the cephalosporinase type. These variants were selected in vitro with a frequency of 10(-6) to 10(-7) and may result from a mutation involving the regulation of Enterobacter cephalosporinases, usually inducible. Data from the literature indicated that this new type of resistance is actually emerging and observed not only in Enterobacter sp. The problem of emergence of R variants exhibiting cross-resistance to beta-lactam antibiotics should be considered when third-generation cephalosporins are used.
Nauciel
C
C
Philippon
A
A
Ronco
E
E
Pilliot
J
J
Guenounou
M
M
Paul
G
G
Brunel
D
D
Outin
H D
HD
D000328:Adult; D000368:Aged; D002511:Cephalosporins / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial; D004755:Enterobacteriaceae / Q000187:drug effects; D004756:Enterobacteriaceae Infections / Q000188:drug therapy; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D018805:Sepsis / Q000188:drug therapy* / Q000382:microbiology; D001618:beta-Lactamases / Q000378:metabolism
D002511:Cephalosporins; D001618:beta-Lactamases
Septicémies à Enterobacter cloacae et E. aerogenes: émergence de variants résistants (céphalosporinase déréprimée) en cours de traitement par des céphalosporines de troisième génération.