In response to the current urgent demand for N95 respirators by healthcare workers responding to the COVID-19 pandemic, with particular emphasis on needs within local medical systems, we initiated an N95 decontamination study using aerosolized hydrogen peroxide or aHP (7% H2O2 solution), via the Pathogo Curis® (Curis) decontamination system. The study has thus far included 10 cycles of respirator decontamination, with periodic qualitative and quantitative fit testing to verify ongoing respirator integrity through the decontamination process, and support a statistical evaluation of successful respirator fit. In addition, we have conducted virologic testing of respirator surfaces and materials to demonstrate a rigorous verification of decontamination.Given that the current pandemic entails a respiratory viral pathogen, it is critical to address these aspects of respirator safety for reuse. These measures are intended to provide a foundation for a suitable decontamination process, which maintains N95 function, and supports safe respirator reuse by healthcare providers. Current results from both respirator fit testing and virologic testing indicate that the process is effective on the basis of zero failure rate on fit-testing of selected respirators, and on complete decontamination of multiple virus species by aHP treatment, comparable to that observed with commercial spore-based biological indicators of sterilization.

24The widespread use of antimicrobials under clinical and agricultural settings has 25 resulted in the evolution of resistance to these compounds.

34Both type III effector proteins and non-ribosomal peptide toxins play important 35 roles for Pseudomonas syringae pathogenicity in host plants, but whether and how 36 these virulence pathways interact to promote infection remains unclear. Genomic 37 evidence from one clade of P. syringae suggests a tradeoff between the total number of 38 type III effector proteins and presence of syringomycin, syringopeptin, and syringolin A 39 toxins. Here we report the complete genome sequence from P. syringae CC1557, 40 which contains the lowest number of known type III effectors to date and has also 41 acquired genes similar to sequences encoding syringomycin pathways from other 42 strains. We demonstrate that this strain is pathogenic on Nicotiana benthamiana and 43 that both the type III secretion system and a new type III effector family, hopBJ1, 44 contribute to virulence. We further demonstrate that virulence activity of HopBJ1 is 45 dependent on similar catalytic sites as the E. coli CNF1 toxin. Taken together, our 46 results provide additional support for a negative correlation between type III effector 47 repertoires and the potential to produce syringomycin-like toxins while also highlighting 48 how genomic synteny and bioinformatics can be used to identify and characterize novel 49 virulence proteins. 50 51 Introduction 52

18Phage tail-like bacteriocins (tailocins) are bacterially-produced protein toxins that can mediate 19 competitive interactions between co-colonizing bacteria. Both theoretical and empirical research 20 has shown there are intransitive interactions between bacteriocin-producing, bacteriocin-21 sensitive, and bacteriocin-resistant populations, whereby producers outcompete sensitive, 22 escape the trap of fitness trade-offs associated with gaining de novo tailocin resistance, and 41 expands our understanding of how sensistive bacterial populations can persist in the presence of 42 lethal competitors. 43 44