Airborne Opportunistic Pathogens in Infrastructures: An Underrecognized and Underappreciated Hazard

Abstract

This article builds on a life-threatening pneumonia that developed following a visit to a worksite. Bacteria encountered in infrastructures normally require either aerobic or anaerobic conditions for survival. Design of the structures involved in handling, processing and storing of wet organic materials reflects and enforces these requirements. Facultative aerobic, opportunistic bacteria that also have developed resistance to antibiotics, in particular, Klebsiella pneumoniae , can thrive under both conditions. Normally these bacteria live in liquid or semi-liquid media such as sludges and biofilms and pose an especial concern to occupations exposed to them. This concern is heightened when bacteria normally present in liquids or semi-liquids become airborne in droplets or solid particles. Aerosolization occurs under processes that disrupt biofilms on surfaces or oxygenate water using compressed air and through highly turbulent flow. A scan of the literature highlight indicates a recent shift to assessing the airborne microbial environment in many types of infrastructures to bacteria capable of causing pneumonia and other diseases. Identification of infection by Klebsiella pneumoniae requires diagnostic tests not commonly used in these situations. Klebsiella pneumoniae is exhibiting increasing antibiotic resistance to the point where lung infections become untreatable. This article will review and analyze the situation involving opportunistic bacteria in the context of infrastructures and will offer approaches for eliminating or at least minimizing the threat to the health of personnel who work in or around infrastructures potentially affected by this predator.