Department of Pathology, Health Sciences Center, Federal University of Espírito Santo, Vitória, Brazil.
State Health Secretariat, Central Public Health Laboratory, Vitoria, Espírito Santo, Brazil.
BMC Microbiol. 2021 Mar 29;21(1):95. doi: 10.1186/s12866-021-02161-x.
This study describes the investigation of an outbreak of diarrhea, hemorrhagic colitis (HC), and hemolytic uremic syndrome (HUS) at a daycare center in southeastern Brazil, involving fourteen children, six staff members, six family members, and one nurse. All bacterial and viral pathogens detected were genetically characterized.
Two isolates of a strain of enterohemorrhagic Escherichia coli (EHEC) serotype O111:H8 were recovered, one implicated in a case of HUS and the other in a case of uncomplicated diarrhea. These isolates had a clonal relationship of 94% and carried the stx2a and eae virulence genes and the OI-122 pathogenicity island. The EHEC strain was determined to be a single-locus variant of sequence type (ST) 327. EHEC isolates were resistant to ofloxacin, doxycycline, tetracycline, ampicillin, and trimethoprim-sulfamethoxazole and intermediately resistant to levofloxacin and ciprofloxacin. Rotavirus was not detected in any samples, and norovirus was detected in 46.7% (14/30) of the stool samples, three of which were from asymptomatic staff members. The noroviruses were classified as the recombinant GII.4 Sydney [P16] by gene sequencing.
In this outbreak, it was possible to identify an uncommon stx2a + EHEC O111:H8 strain, and the most recent pandemic norovirus strain GII.4 Sydney [P16]. Our findings reinforce the need for surveillance and diagnosis of multiple enteric pathogens by public health authorities, especially during outbreaks.
本研究描述了巴西东南部一家日托中心爆发的腹泻、出血性结肠炎（HC）和溶血性尿毒症综合征（HUS）疫情，涉及 14 名儿童、6 名工作人员、6 名家庭成员和 1 名护士。所有检测到的细菌和病毒病原体均进行了基因特征分析。
从一名 HUS 患者和一名非复杂性腹泻患者中分离到两株肠出血性大肠杆菌（EHEC）血清型 O111:H8 菌株，这两株分离株具有 94%的克隆关系，携带 stx2a 和 eae 毒力基因以及 OI-122 致病性岛。EHEC 菌株被确定为序列型（ST）327 的单一位点变异株。EHEC 分离株对氧氟沙星、多西环素、四环素、氨苄西林和复方磺胺甲噁唑具有耐药性，对左氧氟沙星和环丙沙星具有中度耐药性。未在任何样本中检测到轮状病毒，而诺如病毒在 46.7%（14/30）的粪便样本中检测到，其中 3 例来自无症状工作人员。通过基因测序，将诺如病毒分类为 GII.4 Sydney [P16] 重组型。
在本次暴发中，我们能够鉴定出一种不常见的 stx2a+EHEC O111:H8 菌株和最新的流行诺如病毒株 GII.4 Sydney [P16]。我们的研究结果加强了公共卫生当局对多种肠道病原体进行监测和诊断的必要性，特别是在暴发期间。
