重庆地区革兰氏阴性杆菌中β-内酰胺酶的分型与分布

STUDJES ON BETA-LACTAMASES OF GRAM-NEGATIVE BACTERIA FROM CHONGQING DISTRICT

应用超薄层聚丙烯酰胺凝胶等电聚焦技术对本院临床分离的354株革兰氏阴性菌中165株能判断感染来源的产酶株进行β-内酰胺酶定性检测,并首次比较研究了院内和院外感染时β-内酰胺酶的分布特征。结果发现,重庆地区革兰氏阴性杆菌中β-内酰胺酶型别分布较杂,但以OXA-2型为主(占16,36％),TEM-1型、PSE型、SHV-1型均较少,与国内其它地区和国外报道有所不同;院内和院外感染时β-内酰胺酶的分布存在一定差异。院内感染时,绿脓杆菌、肺炎杆菌、大肠杆菌中分别以OXA-2和TEM-1、OXA-1、OXA-2和P-99型β-内酰胺酶为主;院外感染时则分别以OXA-2、OXA-1和OXA-3、OXA-2和TEM-2型β-内酰胺酶为主。沙雷氏菌则不分感染来源,均以染色体介导的β-内酰胺酶为主。 在本实验中,染色体介导的β-内酰胺酶分布相当广泛,在所试9属165株细菌中占到33.3～100％,值得引起高度重视。

The distribution of different types of β-lactamases of Gram-negative bacteria from Chongqing district was studied. The types of β-lactamases of 165 strains isolated clinically were determined qualitatively by the technique of polya-crylamide gel isoelectric focusing electrophoresis; and the distribution characteristics of nosocomial and community strains were compared which is first reported in China. The results showed that the distribution of different types of β-actamases of Gram-negative bacteria from Chongqing district was quite complex and diverse.OXA-2 was the common type<16.36%); while TEM-1, PSE,and SHV-1 were infrequently encountered. The distributions of β-lactamases from nocosomial and community strains were also different. Pseudomonas aeruginosa, Klebstella. pneumonias and Escherichia colt from nosocomial origin produced mainly OXA-2 and TEM-1, OXA-l, and OXA-2 and P-99; while those from community origin produced mainly OXA-2, OXA-1 and OXA -3, OXA-2 and TEM-2 types. On the contrary, Serratia strains, both nosocomial and community isolated,mainly produced chromosome mediated β-lactamases. The common existence of Gram-negative bacteria of different species that produced chromosome mediated β-lactamases(33.3-100%) in this study is emphasized.