Metagenomics for the study of viruses in urban sewage as a tool for public health surveillance.

The application of next-generation sequencing (NGS) techniques for the identification of viruses present in urban sewage has not been fully explored. This is partially due to a lack of reliable and sensitive protocols for studying viral diversity and to the highly complex analysis required for NGS data processing. One important step towards this goal is finding methods that can efficiently concentrate viruses from sewage samples. Here the application of a virus concentration method based on skimmed milk organic flocculation (SMF) using 10L of sewage collected in different seasons enabled the detection of many viruses. However, some viruses, such as human adenoviruses, could not always be detected using metagenomics, even when quantitative PCR (qPCR) assessments were positive. A targeted metagenomic assay for adenoviruses was conducted and 59.41% of the obtained reads were assigned to murine adenoviruses. However, up to 20 different human adenoviruses (HAdV) were detected by this targeted assay being the most abundant HAdV-41 (29.24%) and HAdV-51 (1.63%). To improve metagenomics' sensitivity, two different protocols for virus concentration were comparatively analysed: an ultracentrifugation protocol and a lower-volume SMF protocol. The sewage virome contained 41 viral families, including pathogenic viral species from families Caliciviridae, Adenoviridae, Astroviridae, Picornaviridae, Polyomaviridae, Papillomaviridae and Hepeviridae. The contribution of urine to sewage metavirome seems to be restricted to a few specific DNA viral families, including the polyomavirus and papillomavirus species. In experimental infections with sewage in a rhesus macaque model, infective human hepatitis E and JC polyomavirus were identified. Urban raw sewage consists of the excreta of thousands of inhabitants; therefore, it is a representative sample for epidemiological surveillance purposes. The knowledge of the metavirome is of significance to public health, highlighting the presence of viral strains that are circulating within a population while acting as a complex matrix for viral discovery.

Zollinger-Ellison syndrome due to a borderline mucinous cystadenoma of the ovary.

A Zollinger-Ellison syndrome due to an ovarian mucinous cystadenoma of borderline malignancy is reported in a 76-year-old woman. Immunostaining procedures showed reactivity for gastrin in neoplastic cells. After operation, the patient has remained without symptoms for 6 years. This is the fifth case reported in the literature. All of these ovarian tumors were considered mucinous cystadenomas histologically.

Squamous papilloma of the esophagus: report of six cases with long-term follow-up in four patients.

Squamous papilloma of the esophagus is a benign tumor. The diagnosis is usually made accidentally when an upper gastrointestinal endoscopy is performed due to upper abdominal or esophageal symptoms. After having reviewed 14,900 upper gastrointestinal endoscopies during the past 8 yr, we report six additional cases of esophageal squamous papilloma. The lesion seems to be relatively quiescent without apparent malignant changes, at least on a short-term basis. The etiology is unknown; however, we conclude that gastroesophageal reflux may predispose to the lesion and that endoscopic follow-up on these patients may be unnecessary due to the benign nature of the lesion.