Hitchhiking of microbes and their friendships

Abstract

Fomite transmission is considered as the main transmission route for infectious diseases in built environments. The transmitted pathogens, although notorious, reveal their inherent human-like social behavior. These pathogens “hit the road” by hitchhiking on human hands. Along the journey, these pathogens make friends and foes. This microscopic society, including the “roadmap” and “friendship” of a surrogate tracer/invader for common nosocomial bacterial pathogens (transmission physics and microbial invasion ecology), was analyzed in this thesis. To predict the destinations of pathogens by learning their roadmap (physics of fomite transmission), I selected a substitute for pathogens (Lactobacillus delbrueckii subsp. bulgaricus) to analyze for the purpose of safety. Then, the substitutes were invited into an office space with human participants for 1 day while wearing lab-made, high spatiotemporal resolution tracker “backpacks” (quantitative PCR). Next, we closely monitored the tracks of these substitutes and drew roadmaps (surface touch network) to learn their behavioral patterns. Based on this knowledge, we were able to simulate the journey of the substitutes virtually thousands of times (agent-based model) to predict their possible destinations in a suburban area (environmental surface), shore (oral mucous membrane), forest (nostril), or wetland (eye). Finally, in case their unwelcome pathogenic counterparts have contaminated these nature reserves, we propose an optimized system to restrict their entry by distributing roadblocks (targeting surface hygiene) and changing the schedule of transport by hand (targeting human behaviors). There are other ways of predicting the destinations of substitute microbes, such as by studying their friendships (ecology of fomite transmission). These substitute microbes may travel the road on their own (transmission independence as the first invasion ecology principle) or operate with their global correspondents on a clandestine mission (co-transferring relationship as an alternative mechanism to transmission independence). In the latter case, we can pinpoint their global correspondents who are notable and newsworthy (amplicon DNA sequencing) and may reveal the plans of the substitutes. However, in many cases, the substitutes only trust those who speak the same language (i.e., are phylogenetically similar). Their migration is fast and effective (high dispersal potential as the second principle), which is attributed to the full use of transportation by hand (proximity effect as the third principle). By learning their friendships and temperaments, we are able to predict their behavior at the population level and social dynamics (using the ecological neutral model and others). Therefore, we can evaluate the degree of threat faced by the nature reserves of mucous membranes. These connections of microbes are our target for behavior modulation. This knowledge can be transitioned to management of the pathogenic counterparts of the substitutes. A technical summary of “Hitchhiking of microbes and their friendships” is “Trilogy of simulation of fomite transmission: molecular basis, physics, and ecology”. We observe these microbes either out of concern or out of curiosity. There are astonishing connections between you and me and microbes. We are all governed by the universal principles of ecology.