Scavia Gaia, Gianviti Alessandra, Labriola Vincenzo, Chiani Paola, Maugliani Antonella, Michelacci Valeria, Minelli Fabio, Tozzoli Rosangela, Caprioli Alfredo, Morabito Stefano
European Union and National Reference Laboratory for E. coli, Dip. Sicurezza Alimentare, Nutrizione, Sanità Pubblica Veterinaria, Istituto Superiore di Sanità, Rome, Italy.
Dipartimento di Nefrologia-Urologia, Ospedale Pediatrico Bambino Gesù, Roma, Italy.
J Med Microbiol. 2018 Jun;67(6):775-782. doi: 10.1099/jmm.0.000738.
Shiga toxin-producing (STEC) represents a major issue for public health because of the severity of the associated illnesses, including haemolytic uraemic syndrome (HUS). In 2015, investigation of a case of HUS revealed an outbreak of Shiga toxin-2-producing O26 : H11 infection in a nursery in Italy. The investigation showed that the infection was transmitted to cases' contacts via person to person. The case finding was performed by testing for STEC stool samples of the HUS case's contacts within the family and the nursery. STEC O26 isolates were characterized by whole genome sequencing. Confirmed cases were repeatedly tested to monitor the duration of STEC shedding. Eleven STEC O26 cases were identified, including adults and asymptomatic patients. Clinical illness was only observed in children. Strain characterization revealed that a single clone harbouring the a and genes and the complete array of STEC-associated virulence genes, belonging to ST(21), was implicated in the outbreak. To reduce bacterial shedding, patients were treated with cefixime following clinical recovery. This antibiotic was well tolerated and did not induce any apparent consequences on patients' health. This study confirms that Stx2-producing O26 represents an emerging public health problem. The occurrence of outbreaks of infection by Stx2-producing O26 in nurseries is of particular concern, given the high probability of infection progressing in severity and resulting in secondary cases.
产志贺毒素大肠杆菌（STEC）是一个重大的公共卫生问题，因为与之相关的疾病，包括溶血性尿毒综合征（HUS），病情严重。2015年，对1例HUS病例的调查显示，意大利一家托儿所爆发了产志贺毒素2的O26 : H11感染。调查表明，感染是通过人与人之间传播给病例的接触者的。通过检测该HUS病例在家庭和托儿所内接触者的STEC粪便样本进行病例发现。对STEC O26分离株进行全基因组测序分析。对确诊病例进行反复检测，以监测STEC排菌持续时间。共识别出11例STEC O26病例，包括成人和无症状患者。仅在儿童中观察到临床疾病。菌株特征分析显示，一个携带a和基因以及全套STEC相关毒力基因、属于ST(21)的单一克隆与此次暴发有关。为减少细菌排菌，临床康复后的患者接受了头孢克肟治疗。这种抗生素耐受性良好，未对患者健康造成任何明显影响。本研究证实，产Stx2的O26是一个新出现的公共卫生问题。鉴于感染有很高概率进展为重症并导致二代病例，产Stx2的O26在托儿所爆发感染尤其令人担忧。
