Legionella pneumophila (Lp) is a significant cause of nosocomial, community-acquired, and travel-associated pneumonia in industrialized regions. Legionellosis has been a nationally notifiable disease in Canada since 1986, with an average of 75 cases reported annually; however, only the most severe, and often fatal, cases are reported or investigated. Here, epidemiological relationships, types, and distribution of Lp referrals to the Canadian national reference center were studied. Lp strains from different years, sources, and geographic locations were subtyped using a sequence-based typing (SBT) scheme and by the 'Joly' and/or 'Dresden' monoclonal antibody panels. Included were 128 epidemiologically unrelated clinical and 86 unrelated environmental strains. Sixty-four (index of diversity [IOD] = 0.964) and 45 (IOD = 0.888) sequence types (STs) were observed among clinical and environmental sources, respectively. Serogroup (sg) 1 was represented by 60.2% (77/128) and 52.3% (45/86) of clinical and environmental strains, respectively, and 63.6% (49/77) and 15.6% (7/45) of those were mAb2-positive, respectively. Serogroup 1, ST1 accounted for 14.1% (18/128) and 30.2% (26/86) of unrelated clinical and environmental isolates, respectively. This database will serve as a basis for Canadian epidemiological surveillance efforts and is linked to global surveillance initiatives curated by the European Working Group for Legionella Infections (EWGLI) network.

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Zaire Ebola virus (ZEBOV) is a pathogen that causes severe hemorrhagic fever in humans and non-human primates. There are currently no licensed vaccines or approved treatments available against ZEBOV infections. The goal of this work was to evaluate different treatment strategies in conjunction with a replication deficient, recombinant human adenovirus serotype 5-based vaccine expressing the Zaire Ebola virus glycoprotein (Ad-CAGoptZGP) in Ebola infected mice and guinea pigs.Guinea pigs were treated with Ad-CAGoptZGP in combination with different treatment strategies after challenge with guinea pig adapted-ZEBOV (GA-ZEBOV). B10.BR mice were used to further characterize efficacy and immune responses following co-administration of AdCAGoptZGP with the most effective treatment: AdHu5 expressing recombinant IFN-α (hereafter termed DEF201) after challenge with a lethal dose of mouse adapted-ZEBOV (MA-ZEBOV).In mice, DEF201 treatment was able to elicit full protection against a lethal dose of MA-ZEBOV when administered 30 minutes after infection. In guinea pigs the Ad-CAGoptZGP and DEF201 combination therapy elicited full protection when treated 30 minutes post-exposure and were a superior treatment to Ad-CAGoptZGP supplemented with recombinant IFN-α protein. Further analysis of the immune response revealed that addition of DEF201 to Ad-CAGoptZGP enhances the resulting adaptive immune response against ZGP. The results highlight the importance of the innate immune response in the prevention of ZEBOV pathogenesis and support further development of the Ad-CAGoptZGP with DEF201 treatment combination for post-exposure therapy against ZEBOV infection.

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