Staphylococci isolated from animals and food with phenotypically reduced susceptibility to β-lactamase-resistant β-lactam antibiotics
Staphylococci isolated from animals and food with phenotypically reduced susceptibility to β-lactamase-resistant β-lactam antibiotics
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DOI：
10.1556/avet.52.2004.1.2
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发表时间：
2004-01-01
影响因子：
0.9
通讯作者：
Somogyi, P
中科院分区：
文献类型：
--
作者：
Kaszanyitzky, EJ;Egyed, Z;Somogyi, P
采用扩散试验对近两年来从动物和食物中分离的1921株葡萄球菌的耐药模式进行了研究。其中，金黄色葡萄球菌抑菌区直径小于15 mm的仅有35株，凝固酶阴性葡萄球菌（CNS）抑菌区直径小于18 mm的仅有4株。对39株菌株进行了甲氧西林e -试验和PCR检测mecA基因，以确定它们是否为真正的耐甲氧西林葡萄球菌。39株病原菌中仅有2株对盘片扩散法青霉素敏感；然而，进一步的青霉素酶检测表明它们产生p -内酰胺酶。膜片扩散试验中金黄色葡萄球菌15株，CNS 4株，耐药19株，中间7株；e试验中耐药8株，中间5株。通过纸片扩散和E-test检测的8株oxacillin耐药菌株中有6株携带mecA基因。因此，1921株中只有6株被证明为mecA阳性。这些耐甲氧西林的甲氧西林阳性菌株（5株金黄色葡萄球菌和1株表皮葡萄球菌）起源于两个奶牛群。结果证明，动物中耐甲氧西林金黄色葡萄球菌（MRSA）菌株在匈牙利确实很罕见。选择18株菌株，在加或不加克拉维酸或舒巴坦的情况下，对氧苄西林进行最低抑菌浓度（MIC）筛选，其中3株产生甲氧西林酶。
The antibiotic resistance pattern of 1921 Staphylococcus strains isolated from animals and food within the last two years were examined using diffusion tests. Among them there were only 35 strains of S. aureus having an inhibition zone diameter of 15 mm or less, and 4 strains of coagulase-negative staphylococci (CNS) having a zone diameter of 18 mm or less to 1-mug oxacillin disk. These 39 strains were examined also by E-test to oxacillin and for the detection of the mecA gene by PCR in order to determine whether they might be real methicillin-resistant staphylococci. Among the 39 strains there were only two that were susceptible to penicillin by disk diffusion method; however, further examination by the penicillinase test showed that they produced P-lactamase. While 19 (15 S. aureus, 4 CNS) strains were resistant and 7 strains were intermediate to oxacillin in disk diffusion test, the E-test gave 8 resistant and 5 intermediate results. Six out of the 8 oxacillin-resistant strains examined by disk diffusion and E-test harboured the mecA gene. Thus only 6 out of the examined 1921 strains proved to be mecA positive. These methicillin-resistant, mecA-positive strains (5 of the S. aureus strains and I of the S. epidermidis) originated from two dairy herds. The results prove that methicillin-resistant S. aureus (MRSA) strains in animals are really rare in Hungary. Eighteen strains were chosen and screened for minimal inhibitory concentration (MIC) of oxacillin with or without clavulanic acid or sulbactam, and three of them produced methicillinase enzyme.