currently determining the composition, coordination, and chronology of the multiple-protein molecular machines that synthesize the pneumococcal peptidoglycan cell wall and the homeostatic and stress pathways that regulate peptidoglycan biosynthesis. Dr. Winkler is a Fellow of the American Academy of Microbiology (AAM) and a Fellow of the American Academy for the Advancement of Science (AAAS).
Brian Thomas Ho, PhD, is a Lecturer in Bacteriology at the Institute of Structural and Molecular Biology of the University College London and Birkbeck College, University of London, United Kingdom. He began his research training as an undergraduate researcher in the laboratory of Nancy Kleckner at Harvard University, where he studied changes in chromosome dynamics throughout the bacterial cell cycle. He then went on to earn his PhD degree in the laboratory of John J. Mekalanos at Harvard Medical School, where he studied various aspects of the structure and function of the type 6 secretion system (T6SS) and its effectors in Vibrio cholerae and Pseudomonas aeruginosa. Continuing as a postdoc, his research turned toward studying the T6SS and other contact-dependent secretion systems, such as DNA conjugation, in the context of in vivo microbial communities. His current research focuses on understanding how underlying bacterial cell-cell interactions shape larger macroscopic microbial population dynamics and microbial community structure.
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IN THIS CHAPTER
Why Are Bacteria So Much in the Public Health Spotlight Nowadays?
Bacteria, a Formidable Ancient Life Form
Pressing Current Infectious Disease Issues
Emerging and Reemerging Infectious Diseases
Foodborne and Waterborne Infections
Modern Medicine as a Source of New Diseases
Postsurgical and Other Wound Infections
Surveillance: An Early Warning System
Making Hospitals Safe for Patients
And Now for Some Good News: You’ve Got a Bacterial Infection!
The Helicobacter pylori Revolution
A Brave New World of Pathogenesis Research
Insights into Pathogen Evolution
Modeling the Host-Pathogen Interaction in Experimental Animals
CHAPTER 1
The Power of Bacteria
N ever underestimate a potential adversary that has had a 3-billion-year evolutionary head start.
Why Are Bacteria So Much in the Public Health Spotlight Nowadays?
Widespread clinical use of antibiotics first began in the 1950s. The availability of these “miracle drugs,” as they were called at the time, caused great excitement for both physicians and the public as a whole. They came at a time when the medical community was gaining greater control over infectious diseases than ever before. In clinics and hospitals, hygienic practices such as handwashing and disinfectant use were reducing the risk of disease transmission. In the community, improved nutrition made people better able to resist infections, while less crowded conditions and the availability of clean water helped reduce the spread of disease. Meanwhile, newly developed vaccines were protecting against some much-feared diseases. Despite all this, bacterial infections, such as pneumonia, tuberculosis, cholera, and syphilis, continued to take a heavy toll, and infectious diseases were still a leading cause of death. Antibiotics appeared to be the superweapon that would give humans the final decisive victory over bacteria.
In this early euphoria over the success of antibiotics, scientists and policy makers alike concluded that bacterial infections were no longer a threat and turned their attention to other problems, such as cancer, heart disease, and viral infections. For the next three decades, bacteria were of interest mainly as tractable model systems for studying physiology, genetics, and ecology, and as a source of tools for the new molecular biology and genetic engineering technologies that were revolutionizing all of biology. Confidence that bacterial diseases were completely under control was bolstered by a glut of new antibiotics on the market. Indeed, there was a pervasive perception among the medical community and the public as a whole that bacterial infectious diseases were no longer a problem since they could now be readily and effectively treated with antibiotics.
Unnoticed by all but a few researchers in the field and some pharmaceutical companies, the first cracks soon began to appear in the protective shield against bacterial diseases. This danger became more evident in the late 1970s. Antibiotics were no longer the highly profitable products they had once been, especially not compared to heart medications or tranquilizers, which needed to be taken daily for long periods of time. Additionally, new antibiotics were becoming harder to discover and more expensive to develop. One pharmaceutical company after another quietly cut back or dismantled its antibiotic discovery program. For a while, these cracks appeared not to matter, as there were enough new antibiotics that still worked on the bacteria that had become resistant to the old standbys like penicillin. Warnings from scientists that bacteria were becoming more resistant to antibiotics were largely ignored.
During the late 1980s, however, scientists and health officials began to notice an alarming increase in difficult-to-treat bacterial infections. By 1995, infectious diseases became one of the top five causes of death in the United States. Even with the AIDS epidemic in full swing, most infectious disease deaths were still caused by bacterial diseases, such as pneumonia and bacterial bloodstream infections (sepsis). Why was the incidence of bacterial pneumonia and sepsis increasing? For one, the population as a whole was aging, and older people are more susceptible to these diseases. For another, modern medicine had created a large and growing population of patients whose immune systems were temporarily disrupted due to cancer