[Clinical assessment of peritoneal drainages for necrotizing enterocolitis. A Bayesian approach].

Aim: To assess effectiveness of peritoneal drainages for necrotizing enterocolitis.

Material And Methods: Retrospective cohort study (years 2000 to 2006). Laparotomy or patient's death were considered as failure.

Aminoglycoside 6'-N-acetyltransferase variants of the Ib type with altered substrate profile in clinical isolates of Enterobacter cloacae and Citrobacter freundii.

Three clinical isolates, Enterobacter cloacae EC1562 and EC1563 and Citrobacter freundii CFr564, displayed an aminoglycoside resistance profile evocative of low-level 6'-N acetyltransferase type II [AAC(6')-II] production, which conferred reduced susceptibility to gentamicin but not to amikacin or isepamicin. Aminoglycoside acetyltransferase assays suggested the synthesis in the three strains of an AAC(6') which acetylated amikacin practically as well as it acetylated gentamicin in vitro. Both compounds, however, as well as isepamicin, retained good bactericidal activity against the three strains.

Emergence of clinical isolates of Escherichia coli producing TEM-1 derivatives or an OXA-1 beta-lactamase conferring resistance to beta-lactamase inhibitors.

Sixteen Escherichia coli clinical isolates which were resistant to ampicillin and amoxicillin-clavulanate but susceptible to cephalothin were studied. Eight strains showed the presence of a beta-lactamase which comigrates with reference OXA-1 enzyme. The eight other strains produced different TEM-1 derivatives which had in common a higher Km for penicillins and a higher 50% inhibitory concentration for the beta-lactamase inhibitors.

Novel gyrA point mutation in a strain of Escherichia coli resistant to fluoroquinolones but not to nalidixic acid.

We have previously described a clinical isolate of Escherichia coli (Q2) that is highly resistant to fluoroquinolones (MIC of ciprofloxacin, 16 micrograms/ml) but susceptible to nalidixic acid (MIC of nalidixic acid, 4 micrograms/ml) (N. Moniot-Ville, J. Guibert, N.

Incidence of an aminoglycoside 6'-N-acetyltransferase, ACC(6')-1b, in amikacin-resistant clinical isolates of gram-negative bacilli, as determined by DNA-DNA hybridisation and immunoblotting.

Seventy amikacin-resistant clinical isolates of gram-negative bacteria belonging to nine genera were examined by immunoblotting and by DNA-DNA hybridisation for the presence of ACC(6')1b enzyme, previously called AAC(6')-4, or its encoding gene aacA1b. The organisms mostly had resistance profiles compatible with AAC(6') production and were from South and North America, the Far East and Europe. Polyclonal (rabbit) anti-AAC(6')-1b antisera and an intragenic aacA1b (aacA4) probe derived from the multiresistance plasmid pAZ007 were used.

A silent carbapenemase gene in strains of Bacteroides fragilis can be expressed after a one-step mutation.

High-level carbapenem-resistant (CpmR) mutants, with MICs for imipenem and carbapenem of greater than 128 micrograms/ml, were selected in vitro from four carbapenem-susceptible (CpmS) clinical isolates of Bacteroides fragilis. The CpmS strains produced very low levels of beta-lactamase activity, which was increased approx. 50- to 100-fold in the CpmR mutants.