32种抗菌药物对临床分离猪源链球菌的体外抗菌活性

Antimicrobial Susceptibility in vitro of 32 Drugs Against Pig Streptococcus Isolates in China

采用微量稀释法测定了 32种药物对临床分离猪源链球菌的体外最小抑菌浓度 (MIC) ,以美国临床检验标准委员会 (NCCLS)的临界浓度做为判断标准 ,判定了猪源链球菌对 32种药物的耐药性。结果表明 ,临床分离的菌株以耐药菌为主 ,且 96 6 %的菌株呈多重耐药 ,4 1%菌株为链霉素高耐药菌株 (MIC≥ 2mg mL) ;对磺胺类药物(92 3%～ 98 3% )、氨基糖甙类药物 (70 8%～ 78 5 % )、四环素类 (72 3% )、林可胺类 (6 6 2 %～ 6 4 6 % )、大环内酯类(5 3 8%～ 6 7 7% )耐药性最为严重 ,对青霉素类 (18 5 %～ 5 3 8% )、头孢菌素类 (18 5 %～ 5 6 9% )、泰妙灵 (2 1 5 % )和喹诺酮类药物 (36 9%～ 78 5 % )耐药性次之 ,而所选菌株对氯霉素类药物氟苯尼考均敏感 ;检测了所有耐 β内酰胺类抗生素菌株是否产 β内酰胺酶 。

A number of 65 Streptococcus species isolated from diseased pigs were surveyed for in vitro minimal inhibitory concentration (MIC) to 32 drugs by microdilution test. Clinical categorization of isolates as susceptible or resistant was based on MIC interpretative standards of the National Committee for Clinical Laboratory Standards(NCCLS). None of the strains were susceptible to all antimicrobial compounds tested and most strains(96.6%) were multidrug-resistant. High level resistance to streptomycin was also detected. Resistance to sulfonamides(92.3%～98.3%), aminoglycosides (70.8%～78.5%), lincosamides (66.2%～64.6%), tetracyclines (72.3%) and macrolides(53.8%～67.7%) were most frequent, then β-lactam(18.5%～56.9%) and quinolones(36.9%～78.5%) resistance, while all strains were susceptible to florfenicol,78.5% strains were susceptible to Taimulin. All resistant strains to β-lactam were tested for β-lactamase production and the results were negative.