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BACTERIAL PATHOGENICITY AND CHARACTERISATIONEn t ero pat h og en i ci ty m a r kers i n Escrt erichia coli isolated from infants with acute diarrhoea and healthy controls in Rio de Janeiro, Brazil Sa'o Paulo, Brazil Faeces from urban children < 2 years old with acute diarrhoeal illness and from nondiarrhoeal infants (controls) were examined for Escherichia coli and other enteropathogens. A total of 990 E. coli isolates from 100 patients and 50 controls was tested for enteropathogenic E. coli (EPEC) serotype (O:H), adherence to HEp-2 cells after incubation for 3 and 6 h, fluorescent actin staining (FAS), DNA hybridisation with EAF, eaeA, STh, STp and EAggEC probes and production of heat-labile enterotoxin (LT) and verocytotoxin (VT) with Y1 and Vero cells. EPEC were the most prevalent enteropathogens in patients (32.7%; and 14% in controls). Enteroinvasive E. coli (EIEC) and Vero cytotoxin-producing E. coli (VTEC) were not detected. The rate of isolation of enterotoxigenic E. coli (ETEC) was identical in both groups. Among the EPEC isolates the prevalent serotypes were Olll:H2, 055:NM and 01 19:H6. Localised adherence (LA) was found significantly more frequently in isolates from patients (19.6%) than controls (2.1%). All LA-positive EPEC isolates were FASf and eaeAf, but only 75.2% of them hybridised with the EAF probe. Diffusely adhering E. coli (DAEC) and enteroaggregative E. coli (EAggEC) were found with equal frequency in patients and controls. Twenty-seven E. coli isolates were negative for EAF but positive for eaeA and FAS and produced LA in 6-h adherence tests. These EAF-/eaeA+ strains were the only putative enteropathogen identified in seven patients and were not found in controls. The ability of these strains to elicit ultrastructural cell alterations and cell-signalling events was evaluated in Caco-2 cells (human colon carcinoma cell line) by the gentamicin invasion assay and by transmission electron microscopy. The numbers of intracellular bacteria in cell invasion tests varied from 0.4% to 1.6% of the cellassociated bacteria after a 6-h incubation period. Tyrosine phosphorylation of host cell proteins was assessed in HEp-2 cells by immunofluorescence microscopy and all strains gave positive results. EAF-/eaeA+ E. coli strains express most of the virulence properties found among true EPEC strains and can be a relevant cause of infant diarrhoea in developing countries.

New York State had 180,458 cases of SARS-CoV-2 and 9385 reported deaths as of April 10th, 2020. Patients with cancer comprised 8.4% of deceased individuals1. Population-based studies from China and Italy suggested a higher COVID-19 death rate in patients with cancer2,3, although there is a knowledge gap as to which aspects of cancer and its treatment confer risk of severe COVID-19 disease4. This information is critical to balance the competing safety considerations of reducing SARS-CoV-2 exposure and cancer treatment continuation. Since March 10th, 2020 Memorial Sloan Kettering Cancer Center performed diagnostic testing for SARS-CoV-2 in symptomatic patients. Overall, 40% out of 423 patients with cancer were hospitalized for COVID-19 illness, 20% developed severe respiratory illness, including 9% that required mechanical ventilation, and 9% that died. On multivariate analysis, age ≥ 65 years and treatment with immune checkpoint inhibitors (ICI) within 90 days were predictors for hospitalization and severe disease, while receipt of chemotherapy within 30 days and major surgery were not. Overall, COVID-19 illness is associated with higher rates of hospitalization and severe outcomes in patients with cancer. Association between ICI and COVID-19 outcomes will need interrogation in tumor-specific cohorts.

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