Riaño Ioana, Moreno Miguel Angel, Teshager Tirushet, Sáenz Yolanda, Domínguez Lucas, Torres Carmen
Area de Bioquímica y Biología Molecular, Universidad de La Rioja, 26006 Logroño, Spain.
J Antimicrob Chemother. 2006 Oct;58(4):844-7. doi: 10.1093/jac/dkl337. Epub 2006 Aug 24.
To carry out the characterization of the genes encoding extended-spectrum beta-lactamases (ESBLs) and their genetic environments in four expanded-spectrum cephalosporin-resistant Salmonella enterica isolates (serovars: two Virchow, one Enteritidis, one Rissen) recovered during the monitoring programmes performed in Spain by the VAV Network from faecal samples of pigs, poultry and laying hens at the slaughterhouse level.
The presence and characterization of ESBL genes as well as their genetic environments in the four S. enterica isolates were investigated by PCR and sequencing. The presence of other resistance genes was also analysed by PCR and sequencing.
Three avian S. enterica isolates (two Virchow and one Enteritidis) harboured the bla(CTX-M-9) gene combined with bla(TEM-1b). The bla(CTX-M-9) gene was included in these three isolates in a class 1 integron with the following 5'-->3' structure: integron 1 variable region (dfrA16-aadA2 gene cassettes)-qacEDelta1-sul1-orf513-bla(CTX-M-9)-orf3-like-orf1005. The sul2 gene was also detected in these three bla(CTX-M-9)-containing isolates and tet(A) in one of them. The two serovar Virchow isolates showed an indistinguishable PFGE pattern, although they were recovered from different animal species (broiler and laying hen). A porcine ESBL-positive isolate (serovar Rissen) harboured the bla(SHV-12) gene combined with bla(TEM-1b). This bla(SHV-12)-containing isolate also harboured the tet(A), aadA and sul1 genes.
The emergence of ESBL-producing S. enterica isolates among food animals is described for the first time in Spain, with those of the CTX-M group being the predominant ESBLs detected.
对在西班牙由VAV网络在屠宰场层面开展的监测项目中，从猪、家禽和蛋鸡粪便样本中分离出的4株对广谱头孢菌素耐药的肠炎沙门氏菌（血清型：2株维尔肖、1株肠炎、1株里森）中编码超广谱β-内酰胺酶（ESBLs）的基因及其遗传环境进行特征分析。
通过PCR和测序对4株肠炎沙门氏菌分离株中ESBL基因的存在情况及其特征以及它们的遗传环境进行研究。还通过PCR和测序分析其他耐药基因的存在情况。
3株禽源肠炎沙门氏菌分离株（2株维尔肖和1株肠炎）携带bla(CTX-M-9)基因并与bla(TEM-1b)基因结合。这3株分离株中的bla(CTX-M-9)基因包含在一个1类整合子中，其5'→3'结构如下：整合子1可变区（dfrA16-aadA2基因盒）-qacEDelta1-sul1-orf513-bla(CTX-M-9)-orf3样-orf1005。在这3株携带bla(CTX-M-9)的分离株中还检测到了sul2基因，其中1株还检测到tet(A)基因。2株血清型维尔肖分离株尽管从不同动物物种（肉鸡和蛋鸡）中分离得到，但显示出难以区分的PFGE图谱。1株猪源ESBL阳性分离株（血清型里森）携带bla(SHV-12)基因并与bla(TEM-1b)基因结合。这株携带bla(SHV-12)的分离株还携带tet(A)、aadA和sul1基因。
西班牙首次报道了食用动物中产生ESBL的肠炎沙门氏菌分离株的出现，其中CTX-M组是检测到的主要ESBLs。
