Xanthomonas maltophilia is an opportunistic bacteria capable of giving
rise to severe infections in particular in patients hospitalised in i
ntensive care units. The major problems raised in the isolation of thi
s pathogen are the necessity of distinguishing between colonisation an
d infection, and its usual multi-resistance to antibiotics. A study of
31 stains isolated at the University Hospital of Dijon and Nice has s
hown that the majority of the strains produced a metalloenzyme which l
ed to a constant resistance to imipenem; 28 strains also produced an a
dditional inducible beta-lactamase which hydrolysed ticarcillin, piper
acillin, cefotaxime, ceftazidime and aztreonam. Amongst the combinatio
ns of beta-lactamase inhibitors with beta-lactams tested, the only one
which showed synergistic properties was clavulanic acid associated wi
th ticarcillin or aztreonam. The activity of the formulation ticarcill
in + clavulanic acid was confirmed in 13 patients hospitalised in the
intensive care unit of the University Hospital of North Amiens who had
been treated by monotherapy in 10 cases, for pneumopathy or septicemi
a. A clinical cure and bacteriological eradication were obtained in 12
out of 13 cases. The formulation ticarcillin + clavulanic acid alone
or in association with quinolones thus comprised an effective therapy
in vitro and in vivo for Xanthomonas maltophilia infections.