Antibiotics and Antibiotic Resistance

Alain L. Fymat*

DOI: 10.26717/BJSTR.2017.01.000117

Received: May 22, 2017   Published: June 05, 2017

To view the Full Article   Peer-reviewed Article PDF

Abstract

According to the World Health Organization (WHO)’s “First Global Report on Antibiotic Resistance”, and the U.S. Centers for Disease Control & Prevention (CDC&P), the spread of “superbugs” - bacteria that have changed in ways that render antibiotics ineffective against them - is a serious and growing threat around the world. Once common treatments for everyday intestinal and urinary tract infections, pneumonia, infections in newborn, and diseases like gonorrhea are no longer working in people. Thus, in 2013, 2 million people in the U.S. were infected with antibiotic-resistant bacteria, and 23,000 of them die each year as a result.

Superbugs are bacteria-resistant to one or more antibiotics, and they make it difficult to treat or cure infections that once were easily treated. The antibiotic has lost its ability to control or kill bacterial growth. The bacteria can even grow in a sea of antibiotics because the antibiotic does not touch them. The bacteria have acquired the ability to destroy the antibiotic in order to protect themselves. They have developed a gene for resistance to, say, penicillin, and that gene protects them. A genetic mutation might enable bacteria to produce enzymes that inactivate antibiotics. Or, a mutation might eliminate the target that the antibiotic is supposed to attack. Bacteria may have developed resistance to five or six antibiotics so, in treatment, we do not know which one to choose or whether it will be effective. The bacteria have accumulated resistance by developing new genes. In other words, genetics is working against us!

Misuse of antibiotics to treat viruses rather than bacteria for which they are intended only contributes to antibiotic resistance. The same holds true for other uses whereby 80% of the antibiotics produced are fed to animals: beef cattle, chickens, hogs,... to help them grow “better” and put on more weight. The animals excrete the antibiotics in a largely unbroken form, which enter the environment (ground, water) and retain their ability to affect bacteria and promote antibiotic resistance. There is now a paucity of new antibiotics to take care of these superbugs. So we remain at the mercy of bacteria!

Additionally, there is a growing scientific awareness of the impact of antibiotics on the human and animal microbiome - our internal environment of commensal, symbiotic, and pathogenic microorganisms that completely shares our body space, are essential to our gut efficiency, and are at the centre of our immune system. The impact of antibiotics on this internal environment is devastating and links are rapidly being made between our overuse of antibiotics and the epidemic of chronic diseases such as cancer and diabetes. 23,000 deaths a year from superbugs is just a small and obvious part of the story. Much more insidious and pervasive is the wider story of chronic disease that massive overuse of antibiotics is contributing too.

In this paper, to better understand the important phenomenon of antibiotic resistance, I shall begin by a review of antibiotics: their discovery, the history of their development, their modes of action, their clinical activities, and the factors determining response to therapy with antibiotics. I shall then investigate the mechanisms of antibiotic resistance, review some major epidemics due to antibiotic resistance and infectious diseases and antibiotic resistance. Antibiotics do not work all the time, their inappropriate use, nosocomal infections, and possible reservoirs of antibiotic resistant animal organisms causing human diseases will then lead us to an update on the present situation, highlighting the nanopore revolution in genomic sequencing of drug-resistant bacteria, precious nanometals, and look forward to the future of antibiotics.

Abbreviations: AHA/JCAH: American Hospital Association/Joint Commission on Accreditation of Hospitals; ARI: Antibiotic Resistance Island; CDC&P: (U.S.) Centers for Disease Control & Prevention; CRE: Carbapenem-Resistant Enterobacteriaceae (a superbug); ESBL: Extended- Spectrum Beta-Lactamase; FDA: (U.S.) Food & Drug Administration; MDR: Multiple Drug Resistance; MIC: Minimum Inhibitory Concentration; MRSA: Methicillin- Resistant Staphylococcus aureus (MRSA); MSSA: Methicillin-Sensitive Staphylococcus aureus; ORSA: Oxacillin-Resistant Staphylococcus aureus; NAS: (U.S.) National Academy of Sciences; NRC: (U.S.) National Research Council; VRE: Vancomycin-Resistant Enterococcus; T2DM: Type 2 Diabetes Mellitus; WHO: World Health Organization

Introduction and Background | Brief History of Antibiotics Development | Antibiotics from Scratch | Modes of Action of Antibiotics | Antibiotic Clinical Activities | Factors Determining Response to Therapy With Antibiotics | Mechanisms of Antibiotic Resistance | Infectious Diseases and Antibiotic Resistance | Antibiotics Do Not Work All the Time | Inappropriate Use of Antibiotics | On Nosocomial Infections | Possible Reservoirs of Antibiotic-Resistant Animal Organisms Causing Human Diseases | Update on the Present Situation | The Nanopore Revolution In Genomic Sequencing Of Drug-Resistant Bacteria | Summary and Conclusion | References | Figures | Tables |