Microrganisms elude our control

Implications:

Our experience with antibiotics has consistently shown that resistance occurs within 3-5 years of their widespread utilization. Our more recent experience with antiviral agents has been similar. Without diminishing the important role that antimicrobials have played in our recent history, it has also underscored their limitations. While this is of concern, there is also considerable concern in the international microbiology community regarding mutations within microorganisms that would allow them to 'jump species' and infect humans, or would enhance the virulence of existing pathogens. This fear is enhanced by the indiscriminate utilization of antimicrobial agents associated with ‘modern’ agricultural practices worldwide, which are changing the microbial ecology and potentially selecting out new pathogens to humans and/or to our food supply.

 

Analysis: The impact of environmental changes (e.g., deforestation, industrial pollution, global warming, spent uranium ordinance) and agricultural practices (monoculture, pesticides, chemical fertilizers, and genetically reengineered plants, etc.) on the microbial ecology may represent a serious threat. These environmental changes and agricultural practices present potential risks as they generate unnatural conditions of disturbance that will invite opportunistic microbes to fill the ecological spaces previously occupied by balanced populations of neutral or commensal species. Due to their adaptive and rapid mutational capabilities, emerging pathogens will 'learn' to exploit new circumstances in unprecedented ways, potentially affecting our ability to provide a sustainable food supply and/or through human epidemics and pandemics.

While the stark facts observed from a review of worldwide agricultural practices, human demographic shifts and microbial ecology are disturbing, the synergies that they represent are alarming. First, they have created the perfect media for microbial growth: slaughterhouse slush, filthy feedlots, sewers and manure ponds, battery-cage poultry operations, and massive nutritionally weakened, immune-compromised populations. Second, they have created remarkably efficient modes of transmission for pathogenic microorganisms: overcrowded urban centers that facilitate transmission of respiratory organisms; unsanitary water that facilitates transmission of enteric microorganisms; rapid international travel and shipping that facilitates world wide dispersion; and, disruption of traditional social structures with movement of men seeking work to urban centers, and the creation of hordes of impoverished sex-workers that facilitates sexual transmission. Finally, the shifts in the microbial ecology due to changes in climate, deforestation, pollution, irresponsible genetic engineering, and the replacement of strict livestock sanitation standards with the use of prophylactic antimicrobials will selectively allow resistant and/or new organisms to occupy roles never before encountered in the evolution of our planet.

Our current strategies to address the scenario are ineffective. Surveillance mechanisms will be after the fact. Antimicrobials, even if they are effective, will quickly select out resistant organisms. Vaccines will require years to develop and, based on our current experience, decades to effectively deploy.