肺炎克雷伯菌和铜绿假单胞菌β-内酰胺酶的分类和分布研究

目的：研究肺炎克雷伯菌(Kpn)所产各种组成型β—内酰胺酶和铜绿假单胞菌(Pae)所产的各种诱导型β—内酰胺酶(诱导酶)的分布情况。方法：采用多底物改良相邻纸片法(协同法检测β—lase，拮抗法检测诱导酶)检测205株细菌。结果：(1)Kpn和Pae的β—lase总检出率分别为46．67％，93．00％。(2)Kpn产青霉素酶、头孢菌素酶各2株，产广谱酶11株(10．48％)，产ESBLs 34株(32．38％)，未检出碳青霉烯酶；34菌产ESBLs菌株中，以头孢他啶、氨曲菌、头孢噻肟为底物检出率分别是82．35％，85．29％，94．12％；呼吸道与非呼吸道两组Kpn在产酶率、产酶类型方面差异显著。(3)93株Pae产诱导酶临床株中，产诱导型青霉素酶1株，超广谱酶92株(98．92％)，以头孢噻肟、哌拉西林、氨曲南、头孢他啶为作用底物的菌株依次为53株(56．99％)、60株(64．52％)、74株(79．57％)、77株(82．80％)，未出现以头孢唑啉为作用底物的诱导酶菌株。结论：本组二种菌的β—lase总检出率和各种β—lase检出率均不同；Kpn菌产β—lase以广谱酶、ESBLs为主，绝大多数Pae临床株产生诱导型超广谱酶(IESBLs)，Pae产其它类型诱导酶很少，所产IESBLs至少有10种。

Classification and distribution of β-lactamases produced by Klebsiella pneumoniae and Pseudomonas aeruginosa

Objective To study the classification and distribution of p-lactamases produced by K. pneumonias and P. aeruginosa . Methods (3-lactamases were detected on 205 strains with a multi-disk test. Results The total positive rate of (3-lactamases produced by K.pneumonia and P.aeruginosa was 46.67% and 93.00% respectively; among K. pneumonia , two strains produced penicillinases or cephalosporinases respectively, 11 strains produced BSBLs (10.48% ), 34 strains produced ESBLs (32.38% ), all did not produce carbapenem-hydrolyzing (3-lactamases. Among 34 strains producing ESBLs, the rate of resistant strain to ceftazidime, aztreonam and cefotaxine was 82.35% , 85.29% and 94.12% , respectively. There was significant difference in (3-lactamases between K. pneumonia isolated from respiratory tract and the other sites. Among 93 strains of P. aeruginosa , the inducible penicillinases and inducible ESBLs were produced by 1 strain and 92 strains respectively; the resistant strains to cefotaxine, piperacillin, aztreonam and ceftazidime was 53 (56.99%),60 (64.52%),74 (79.57%),77 (82.80% ) respectively. Conclusion Among two kinds of strians, the total producing rate of (3-lactamases and the producing rate of each type of 3-lactamases were different; K. pneumonia produced mainly BSBLs and ESBLs; P. aeruginosa produced mainly inducible ESBLs.