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Background: The management of axilla after Primary Systemic Therapy (PST) for breast cancer is a highly debated field. Despite the proven axillary downstaging occurring after PST, there is still some degree of reluctance in applying sentinel node biopsy (SNB) in the neoadjuvant setting., Patients and Methods: We performed a retrospective analysis on 181 PST patients with axillary positive nodes at presentation treated between 2005 and 2017 at San Raffaele Hospital in Milan. The aim was to observe the application time trend of SNB, to determine the imaging staging power and the axillary downstaging according to molecular subtypes., Results: Median follow-up after surgery was 32.5(IQR: 12-59) months. After PST, 119 (65.7%) patients had no clinically palpable nodes, 72 (39.7%) converted to N0 on final imaging and 34 (18.8%) underwent SNB with an increasing application trend. Axillary-US showed the highest accuracy (69.3%) in re-staging axilla after PST. Staging power of preoperative testing varied with tumour biology: Positive Predictive Value was higher in Luminal A (80% for clinical examination and 100% for axillary-US) and Luminal B (72% and 70.5%) tumours, whilst Negative Predictive Value was higher in HER2 positive (100% and 93.3%), and triple negative (71.4% and 93.3%) tumours. Ninety five (52.5%) patients experienced axillary downstaging after PST, by molecular subtype 15% (3/20) in Luminal A, 46.4% (45/97) in Luminal B, 90.9% (20/22) in HER2+ and 70.3% (26/37) in triple negative breast tumours., Conclusion: SNB application after PST for breast cancer in node positive patients at presentation is increasing. Pre-operative axillary imaging and tumour biology help identify patients who might be candidates for SNB as a single staging procedure., (Copyright © 2019 Elsevier Ltd, BASO ~ The Association for Cancer Surgery, and the European Society of Surgical Oncology. All rights reserved.)

Hybridization on arrays was used to assess the presence of virulence-associated genes and to determine the relatedness of 32 non-O157 sorbitol-negative Escherichia coli isolates from healthy broiler chickens. These isolates were from commercial farms that used feed supplemented with different antimicrobial agents (virginiamycin, bacitracin, salinomycin, narasin, nicarbazin, or diclazuril). For each isolate, fluorescent probes were made from genomic DNA and were hybridized on DNA arrays composed of genes associated with general functions, virulence, iron uptake systems, and DNA repair genes (e.g., mut genes). Hybridization on arrays results showed that isolates from the same farm tended to be clustered but actually represented 18 genetically distinct groups of isolates. Results revealed that some isolates showed similarity to human uropathogenic E. coli or avian pathogenic E. coli. Four avian pathogenic E. coli-like isolates were detected. Another isolate possessed the intimin gene (eaeA) and typical genes of the type 3 secretion system associated with enteropathogenic E. coli and enterohemorrhagic E. coli strains. Genes from a second system (secondary type 3 secretion system) homologous to that found in Salmonella Typhimurium were detected in many isolates. Several of the studied isolates also possessed the aerobactin, salmochelin, and yersiniabactin genes involved in iron acquisition in pathogenic bacteria. Our results clearly suggest that commensal E. coli isolates from chickens are reservoirs of virulence-associated genes and may represent colibacillosis and zoonotic risks.