绵羊羔羊金黄色葡萄球菌与粪肠球菌混合感染的研究

Study on mixed infection of Staphylococcus aureus and Enterococcus faecalis in sheep

为查明新疆南疆某羊场羔羊陆续死亡的原因,采集该羊场8只羔羊的肺脏、脾脏、肝脏、肾、心等组织,对组织进行细菌的分离培养、染色镜检、16S rRNA基因序列分析、药敏试验判断分离菌株对12种抗菌药物的耐药性。结果表明:通过病原分离、革兰染色镜检发现2种菌,一种为蓝紫色圆形葡萄状的球菌,另一种为椭圆形或圆形链状排列的球菌。分离株在普通培养基上生长不良;BHI培养基上生长良好,形成灰白色不透明、扁平的圆形菌落;在鲜血培养基上形成圆形,周围有完全透明的草绿色溶血环,革兰染色为阳性。病原菌均具有一定的毒力,能够致小白鼠死亡。经16S rRNA序列鉴定,扩增条带大小与预期结果相符,与金黄色葡萄球菌和粪肠球菌序列的同源性分别为99.9%、99.7%。分离出的这2株菌均对氯霉素、氨苄西林、庆大霉素有耐药性,对卡那霉素、红霉素、诺氟沙星、四环素敏感,临床上可交替使用以上药物,达到有效治疗的目的。

In order to find out the causes of death of lambs in a sheep farm in southern Xinjiang.The lung,spleen,liver,kidney,heart and other tissues of eight lambs in the sheep farm were collected.The bacteria were isolated and cultured,stained by microscopy,16S rDNA gene sequence analysis,and drug sensitivity test was used to determine the resistance of isolated strains to 12 antibiotics.The results showed that two kinds of bacteria were found by pathogen isolation and Gram staining microscopy,one was blue purple round grape-shaped cocci,and another one was an elliptical or circular chain arrangement of cocci.The isolates grew poorly on the common medium,grew well on the BHI medium,and formed graywhite opaque,flat round colonies.They formed round colonies on the blood medium,surrounded by completely transparent green hemolytic ring,and Gram staining was positive.Pathogens have certain virulence,can cause mouse death.The results of 16S rDNA sequence identification showed that the amplified bands were consistent with the expected results,and the homology with Staphylococcus aureus and Enterococcus faecalis were 99.9% and 99.7%,respectively.The two strains were resistant to chloramphenicol,ampicillin and gentamicin,and were sensitive to kanamycin,erythromycin,norfloxacin and tetracycline.The above drugs can be used alternately in clinic to achieve the purpose of effective treatment.