| The production of extended-spectrum β -lactamases (ESBLs) is the most common mechanism of resistance to the third generation cephlosporins for enterobacterium. ESBLs which is a large species of β -lactamases can hydrolyze the third generation of cephalosporins and monobactams. ESBLs are mainly produced by klebsiella and Escherichia coli. CTX-M type ESBLs is the main genotype of ESBLs in China, especially CTX-M-14 type ESBLs. It is important to study how to treat the infection caused by bacteria producing CTX-M type ESBLs in China. Animal model has been proved a good method to research disease.Mixture of 10%BaSO4 with 1 X 10-8 3 X 108 1 X 109 2 X 109 or 4 X 109cfu/ml Escherichia coli were injected into the peritoneal cavity of 5 groups of rabbits respectively. General conditions, body temperature, leucocyte count and the percentage of neutrophil of the rabbits were closely observed. The data when rabbits died was recorded and the autopsy was performed immediately. The greater omentum was obtained for pathology examination. All survived rabbits were killed on 10th day. After the rabbits were injectedwith bacteria, the leucocyte count and the percentage of neutrophil of all rabbits changed obviously. The mortality of the group injected with 3 X 108 cfu/ml E.coli is moderate(45%), the rabbits of which group died in various period, lasted longest fever time. And the pathology of the greater omentum revealed inflammatory cells infiltration, and some had absecsses. After intraabdominal injection with 3 X 10 cfu/ml Escherichia coli and 10%BaSO4, a stable, replicable, moderate infected animal model of bacterial peritonitis was established, which is similar to clinic in pathology and bacteriology.133 rabbits bacterial peritonitis model was caused by intra-abdominal injected with a mixture of 3 X 108 cfu/ml Escherichia coli producing CTX-M-14 type of ESBLs and 10%BaSO4. The rabbits were randomized divided into four groups. Three groups were administrated ceftazidime(100mg/kg,twice a day), ceftaxime (100mg/kg, twice a day) and piperacillin/tazbactam(225mg/kg, every 8 h) by intramuscular respectively. 4 hours after injected bacteria, the antibiotics were first administered. The fourth group did not give any therapy as the contrast group. The temperature ,leucocyte counts and the percentage of neutrophil of the rabbits were closely observed. The time of rabbit died was recorded and anatomized immediately. Pathology of the great omentum were examinated. Compared with the ceftaxime group and contrast group, the administration of ceftazidime decreased mortality( x2= 5.64, 6.13). Ceftazidime also inhibited the incidence of abdominal abscess in survived rabbits in comparison with the contrast group( x2 =3.93). In addition, the leucocyte counts of the ceftazidime group were recovered normal at the end of treatment, while that of the ceftaxime group and contrast group were still high. All results of ceftazidime group had no distinctness compared with that of piperacillin/tazbactamgroup(P>0.05). The ceftazidime has good treatment results in the bacterial peritonitis caused by Escherichia coli producing CTX-M-14 type of ESBLs.
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