ABSTRACT
We have analyzed the development of fluoroquinolone resistance between 1986 and 1993 among clinical isolates of Enterococcus faecalis from a French hospital. One hundred randomly selected isolates per year were screened for resistance to ciprofloxacin (MIC > 2 micrograms/ml) and for high-level resistance to gentamicin (MIC > 1,000 micrograms/ml). The percentages of ciprofloxacin-resistant strains for these years were as follows: 1986, 0; 1987, 1; 1988 to 1989, 2; 1990, 6; 1991, 16; 1992, 24; and 1993, 14. Eighty-three percent of the ciprofloxacin-resistant isolates were coresistant to high levels of gentamicin. Forty-eight high-level gentamicin-resistant E. faecalis strains, which were resistant (24 strains) or susceptible (24 strains) to ciprofloxacin, were examined by pulsed-field gel electrophoresis (PFGE) of SmaI-digested total DNA. Numerous PFGE types were observed among the ciprofloxacin-susceptible isolates, whereas one type was largely predominant among the ciprofloxacin-resistant strains, which suggests that the increase in fluoroquinolone resistance was due to the spread of a single clone. A 241-bp fragment of gyrA, corresponding to the quinolone resistance-determining region, was amplified and sequenced for seven ciprofloxacin-resistant isolates. Six strains had high levels of resistance (MICs, 32 to 64 micrograms/ml) and had a mutation at position 83 (Escherichia coli coordinates) from Ser to Arg (three strains) or to Ile (two strains) or at position 87 from Glu to Gly (one strain), whereas the low-level-resistant isolate (MIC, 8 micrograms/ml) had no mutations.
Subject(s)
Anti-Infective Agents/pharmacology , DNA Topoisomerases, Type II/genetics , Enterococcus faecalis/drug effects , Mutation/physiology , DNA, Bacterial/analysis , Electrophoresis, Polyacrylamide Gel , Fluoroquinolones , France/epidemiology , Gram-Positive Bacterial Infections/drug therapy , Gram-Positive Bacterial Infections/epidemiology , Gram-Positive Bacterial Infections/microbiology , Microbial Sensitivity Tests , Polymerase Chain ReactionABSTRACT
Adrenocortical function and plasma growth hormone pattern were investigated in 15 patients with chronic obstructive lung disease, in a period of acute respiratory failure and again after recovery. During the acute period, secretion rate and plasma concentrations of cortisol were markedly enhanced; urinary excretion of cortisol metabolites was only slightly increased, suggesting an alteration of the catabolism of cortisol under these conditions; adrenocortical sensitivity to corticotropin and capacity of maximal adrenal secretion were normal. The increase of cortisol secretion was probably due to hypoxemia and/or hypercapnia acting through the hypothalamo-pituitary axis. During the chronic phase of respiratory insufficiency, adrenocortical secretion and responsiveness were within the normal range. Finally, respiratory failure did not stimulate the secretion of growth hormone.
