奶牛乳房炎链球菌的耐药性检测

Detection of Drug Resistance of Streptococcus Isolates from Cow Mastieis

采用微量稀释法测定17种药物对临床分离的57株奶牛乳房炎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）的临界浓度作为判断标准,分析奶牛乳房炎链球菌对17种药物的耐药谱。结果表明,临床分离的菌株以耐药菌为主,且94.73%的菌株呈多重耐药,菌株耐药谱型达16种,对磺胺甲口恶唑（100.0%）、林可霉素（100.0%）、大环内酯类药物（73.7%~94.7%）、四环素类药物（31.6%~78.9%）、氟苯尼考（63.1%）耐药性最为严重,对青霉素类（15.8%~68.4%）、喹诺酮类（15.8%~84.2%）、氨基糖苷类药物（42.1%~47.4%）耐药性次之,对头孢菌素类药物头孢唑啉和头孢噻呋敏感率均为89.5%和73.7%。

Fifty-seven Streptococcus isolates from cow mastitis were surveyed for in vitro minimal inhibitory concentration（MIC） to 17 drugs by microdilution test.Clinical categorization of isolates as sensitive or resistance was based on MIC interpretative standards of the National Committee for Clinical Laboratory Standards（NCCLS）.None of the strains were sensitive to all antimicrobial compounds tested and most strains（94.73%） were multidrug-resistant.The strains showed 16 different drug resistance.Resistance to sulfamethoxazole（100%）,lincomycin（100%）,macrolides（73.7%-94.7%）,tetracyclines（31.6%-78.9%）,florfenicol（63.1%）were most frequent,then penicillines（15.8%-68.4%）,quinolones（36.9%-78.5%） and aminoglycosides（42.1%-47.4%） resistance,89.5% and 73.7% strains were sensitive to cefazolin and ceftiofur,respectively.