Fernández Magalí, Casaux María Laura, Fraga Martín, Vignoli Rafael, Bado Inés, Zunino Pablo, Umpiérrez Ana
Departamento de Microbiología, Instituto de Investigaciones Biológicas Clemente Estable, Avenida Italia 3318, Montevideo 11600, Uruguay.
Plataforma de Investigación en Salud Animal, Instituto Nacional de Investigación Agropecuaria (INIA), Estación Experimental INIA La Estanzuela, Ruta 50, Km 11, Colonia 70000, Uruguay.
Microorganisms. 2023 Jun 29;11(7):1704. doi: 10.3390/microorganisms11071704.
In Uruguay, the mortality of dairy calves due to infectious diseases is high. is a natural inhabitant of the intestinal microbiota, but can cause several infections. The aim of the work was to characterize isolates from intestinal and extraintestinal origin of dead newborn calves. Using PCR, virulence gene characteristics of pathogenic were searched. The pathogenic were molecularly characterized and the phylogroup, serogroup and the Stx subtype were determined. Antibiotic susceptibility was determined using the Kirby-Bauer disk diffusion method and plasmid-mediated quinolone resistance (PMQR) genes with PCR. Finally, clonal relationships were inferred using PFGE. Gene characteristics of the Shiga toxin-producing (STEC), Enteropathogenic (EPEC) and Necrotoxigenic (NTEC) were identified. The prevalence of the , , , , , and genes was high and no , , , , , , or were detected. The prevalence of STEC gene in the dead calves stood out and was higher compared with previous studies conducted in live calves, and STEC LEE+ (Enterohemorrhagic (EHEC)) isolates with // genotypes were more frequently identified in the intestinal than in the extraintestinal environment. isolates were assigned to phylogroups A, B1, D and E, and some belonged to the O111 serogroup. and subtypes were determined in STEC. A high prevalence of multi-resistance among STEC and genes was determined. The PFGE showed a high diversity of pathogenic strains with similar genetic profiles. It can be speculated that EHEC (/) could play an important role in mortality. The , and genes could also have a role in calf mortality. Multidrug resistance defies disease treatment and increases the risk of death, while the potential transmissibility of genes to other species constitutes a threat to public health.
在乌拉圭，奶牛犊因传染病导致的死亡率很高。[某种细菌]是肠道微生物群的天然寄居菌，但可引发多种感染。这项工作的目的是对死亡新生犊牛肠道和肠外来源的[该细菌]分离株进行特征分析。使用聚合酶链反应（PCR）寻找致病[该细菌]的毒力基因特征。对致病[该细菌]进行分子特征分析，并确定其系统发育群、血清群和志贺毒素（Stx）亚型。使用 Kirby-Bauer 纸片扩散法和 PCR 检测质粒介导的喹诺酮耐药性（PMQR）基因来确定抗生素敏感性。最后，使用脉冲场凝胶电泳（PFGE）推断克隆关系。鉴定了产志贺毒素大肠杆菌（STEC）、肠致病性大肠杆菌（EPEC）和产坏死毒素大肠杆菌（NTEC）的基因特征。[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]和[某些基因名称]基因的流行率很高，未检测到[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]、[某些基因名称]或[某些基因名称]。死亡犊牛中 STEC 基因[某个基因名称]的流行率较为突出，与之前对活犊牛进行的研究相比更高，并且具有//基因型的 STEC LEE+（肠出血性大肠杆菌（EHEC））分离株在肠道中比在肠外环境中更频繁地被鉴定出来。[该细菌]分离株被归入系统发育群 A、B1、D 和 E，一些属于 O111 血清群。在 STEC 中确定了[某些 Stx 亚型名称]和[某些 Stx 亚型名称]亚型。确定了 STEC 中多重耐药性以及[某些基因名称]基因的高流行率。PFGE 显示具有相似基因图谱的致病菌株具有高度多样性。可以推测 EHEC（/）可能在死亡率中起重要作用。[某些基因名称]、[某些基因名称]和[某些基因名称]基因也可能在犊牛死亡率中起作用。多重耐药性使疾病治疗变得困难并增加了死亡风险，而这些基因向其他物种的潜在传播对公共卫生构成了威胁。
