[Therapeutic effect of ceftazidime in a rabbit model of peritonitis caused by Escherichia coli producing CTX-M-14 extended-spectrum beta-lactamase].
OBJECTIVE
To study the therapeutic effect of ceftazidime (CAZ) in a rabbit model of peritonitis caused by Escherichia coli producing CTX-M-14 extended-spectrum beta-lactamase (ESBL).


METHODS
The peritonitis model was produced by intra-abdominal injection of a mixture of 3 x 10(8) CFU/ml Escherichia coli producing CTX-M-14 ESBL and 10% BaSO(4). All rabbits were randomized into four groups. Four hours after the bacteria were injected, three groups were intramuscularly administered ceftazidime (100 mg/kg, twice a day), cefotaxime (100 mg/kg, twice a day) and piperacillin/tazobactam (225 mg/kg, every 8 h) respectively. The fourth group did not receive any therapy as a control. The temperature, leucocyte counts and percentage of neutrophils were closely observed. The dying time of rabbits was recorded and anatomized immediately, and pathology of the great omentum was examined.


RESULTS
The temperature of the control group became normal on the 6th day, while the temperature of the other three groups returned normal 48 h after the injection of the bacteria. Compared with the mortality of the cefotaxime-treated group (50%) and the control group (52%), the mortality of the ceftazidime-treated group (22%) was significantly decreased (chi(2) = 5.64, 6.13, P < 0.05). The administration of ceftazidime also inhibited the incidence of abdominal abscess in the survived rabbits (16%) in comparison with the control group (50%, chi(2) = 3.93, P < 0.05). In addition, the leucocyte counts of the ceftazidime-treated group returned normal at the end of treatment, while those of the cefotaxime group and the control group were still high. The above measurements showed no difference between the ceftazidime-treated group and the piperacillin/tazobactam-treated group (P > 0.05).


CONCLUSIONS
Ceftazidime showed good therapeutic effect in peritonitis caused by Escherichia coli producing CTX-M-14 ESBL.
Zhou
Jian-ying
JY
Department of Respiratory Medicine, First Affiliated Hospital, Medical College, Zhejiang University, Hangzhou 310003, China.
Xu
Pan-feng
PF
Chen
Huan
H
Yu
Yun-song
YS
Chen
Ya-gang
YG
D000818:Animals; D002442:Ceftazidime / Q000494:pharmacology / Q000627:therapeutic use*; D004926:Escherichia coli / Q000378:metabolism*; D004927:Escherichia coli Infections / Q000188:drug therapy* / Q000382:microbiology; D010538:Peritonitis / Q000188:drug therapy* / Q000382:microbiology; D011817:Rabbits; D001618:beta-Lactamases / Q000096:biosynthesis*
D002442:Ceftazidime; C456080:beta-lactamase CTX-M-14; D001618:beta-Lactamases