Both bacteria and viruses can cause diseases with similar symptoms,
but may multiply and spread the illness differently.
Antibiotics inhibit bacterial growth and reproduction by
targeting certain molecules in them. Whereas, on the other hand,
antibiotics have no "target" to attack in a virus. Hence, they are not
effective against majority of common respiratory infections like
common cold, flu, bronchitis, sore throats, sinus and ear infections
because they are caused by a virus.
Antibiotic Resistance- A New Global Epidemic
Antibiotic resistance is a global threat. The Centers for Disease
Control and Prevention (CDC) call it-"one of the world's most critical
public health issues." Some medications that used to be standard treatments for
bacterial infections are now less effective or do not work at all.
When an antibiotic has no longer an effect on a certain strain of bacteria,
those bacteria are said to be Antibiotic Resistant.
Antibiotic resistance is one of the world's most threatening health. These are
"Superbugs that refer to the microbes with enhanced morbidity and
mortality due to multiple mutations endowing high levels of resistance
to the spectrum of antibiotics specifically recommended for their treatment.
The misuse of antibiotics is unbridled in India, resulting in "Superbugs" that are
resistant to all known types of drugs. The Million Death Study reported that
diseases such as pneumonia and diarrhea account for 50% of all the deaths in
children, aged 1-59 months in India. The main cause of increasing antibiotic
resistance is the overuse, rather than the "misuse" of antibiotics. It is
estimated that 30% of antibiotics prescribed are unnecessary. To avoid the
threat of these infections, it is important to avoid the consumption of unnecessary antibiotics.
Soon antibiotic resistance will lead to more deaths than cancer.
Till date, much of the research into the practices, prevalence and
patient perspectives of antibiotic misuse have been conducted.
These studies often focus on their interaction with doctors or
advanced healthcare providers, who control the access to antibiotics
through written prescriptions. Due to a shortage of trained doctors,
access to licensed allopathic doctors is limited in Indian villages.
Thus, pharmacists and unlicensed Rural Medical Providers are
commonly the primary sources of healthcare. The role of pharmacists
as firstline healthcare providers, has made it difficult to implement
strict regulatory mechanisms to restrict over the counter dispensing
of antibiotics. As a result, several leading Indian non-governmental
healthcare societies collaborated with the WHO to release the 2012
Chennai Declaration, a five year plan focused on the practical implementation
of antibiotic policies in India.
What are the causes of antibiotic resistance?
We consume medicines with a belief that they ease up our symptoms, without even
thinking little of what we are actually gulping up. Some bacteria undergo
change that helps them resist the medication therapy by either protecting
them from the action of the medication or neutralizing the medication.
These bacteria are Superbugs that survive an antibiotic treatment and multiply,
and pass on their resistant properties to their offsprings. Also,
few of them can transfer their antibioticresistant properties to other
bacteria - as if passing along a cheat sheet to help each other survive.
Viruses and fungi can also become resistant to antimicrobials,
used to treat infections with these microbes.
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Development of resistance commonly occurs in nature.
However, because of the routine use of antibiotics,
bacterial exposure to antibiotics is more frequent and resistance develops
at a faster pace. Without effective antibiotics, common infections such as
bacterial pneumonia, once again, would become life-threatening.
Complex procedures, such as open-heart surgery, would become much
more dangerous and deaths from infection more common.
Consuming antibiotics unnecessarily can increase the risk of emergence
and spread of resistant strains of bacteria. A growing list of infections,
such as Pneumonia, Tuberculosis, Blood poisoning, Gonorrhoea, and foodborne diseases,
are becoming difficult and sometimes impossible, to treat,
as antibiotics become less effective. Hospitals are the focal points
for the spread of these infections.
How Antibiotic Misuse Threatens the Achievements of Modern Medicine?
Antibiotic misuse is when antibiotics are used unnecessarily,
especially when they are not even the appropriate treatment.
Overprescription of these has led to resistant bacteria.
Some bacteria that were once very responsive to antibiotics
have become more and more resistant
According to the CDC,
up to one-third to one-half of antibiotic use in humans is
unnecessary or inappropriate.
Many of the bacterial pathogens
associated with epidemics of human disease have evolved into
Multidrug-Resistant (MDR) forms, subsequent to antibiotic usage.
For example, MDR Mycobacterium tuberculosis is a major pathogen
found in both developing and industrialized nations, and has become the
20-century version of an old pathogen. Other serious infections include
nosocomial (hospital-linked) infections with Acinetobacter baumannii,
Burkholderia cepacia, Campylobacter jejuni, Citrobacter freundii,
Clostridium difficile, Enterobacter spp., Enterococcus faecium,
Enterococcus faecalis, Escherichia coli, Haemophilus influenzae,
Klebsiella pneumoniae, Proteus mirabilis, Pseudomonas aeruginosa,
Salmonella spp., Serratia spp., Staphylococcus aureus,
Staphylococcus epidermidis, Stenotrophomonas maltophilia,
and Streptococcus pneumoniae. In some cases, superresistant
strains have also acquired increased virulence and enhanced transmissibility.
Realistically, antibiotic resistance can be considered as a virulence factor.
There are multiple national and international monitoring programs
for drug-resistant threats, including Methicillin-Resistant Staphylococcus
aureus (MRSA), Vancomycin-Resistant S. aureus (VRSA), Extended Spectrum
Beta-lactamase (ESBL), Vancomycin-Resistant Enterococcus (VRE),
MultidrugResistant Acinetobacter baumannii (MRAB), Carbapenem-Resistant
Enterobacteriaceae (CRE), Drug Resistant Tuberculosis (DRTB).
How bacteria exhibit resistance to antibiotics?
When bacteria grow, multiply and spread, they may develop mutations in their
DNA making them resistant to certain types of antimicrobial drugs.
When antibiotics are used to treat an infection, bacteria that lack
resistance mechanism die, while those who possess the mechanism
may continue to live and multiply. Bacteria can also give certain
resistance mechanisms to other bacteria in a process called horizontal
gene transfer, which increases the speed at which bacteria can evolve
into Superbugs.
Following are the four fundamental mechanisms by which
bacteria exhibit resistance to antibiotics:
1) Enzymatic degradation of antibacterial drugs
Most commonly, the protective enzymes produced by
the bacterial cell add an acetyl or phosphate group to a specific site on the
antibiotic, which reduces its ability to bind to the bacterial ribosomes and
disrupts protein synthesis. For eg., enzymatic deactivation of Penicillin G
takes place in some penicillin-resistant bacteria through the production
of enzyme B-lactamase.
2) Alteration of bacterial proteins that are antimicrobial targets
Another protective mechanism found among
bacterial species is Ribosomal Protection Proteins (RPP). These
protect the bacteria from antibiotics that inhibit protein synthesis by
targeting cellular ribosomes. The mechanism involves the binding of
RPP to the ribosomes in the bacterial cell, which in turn leads to change
in its conformation. This change in shape of ribosome prevents antibiotic
(that targets protein synthesis) from binding to it, allowing the continuous
synthesis of proteins essential for the cell. For eg., alteration of Penicillin
Binding Proteins which is the binding target site of penicillin in MRSA and
other penicillin-resistant bacteria.
3) Changes in membrane permeability to antibiotics
Drug accumulation can be reduced by decreasing the drug permeability
or increasing active efflux (pumping out) of the drugs across the cell surface.
These pumps are within the cell membrane of certain bacterial species and are
used to efflux antibiotics out of the cell before they create any damage.
They are often activated by a specific substrate associated with an antibiotic as
in fluoroquinolone resistance.
4) Alteration of metabolic pathway
Bacteria use folic acid to synthesize the nucleic acids to make up their DNA. Sulfonamides are
a class of antibiotics that inhibit the synthesis of these nucleic acids by interfering
with the folic acid synthesis. There are some sulfonamide-resistant bacteria that
make use of the preformed folic acid instead of using ParaAminobenzoic Acid (PABA)
which is an important precursor for folic acid synthesis. This is an example of alteration
of metabolic pathway.
Various other mechanisms are used by infectious bacteria to deal
with antibiotics. In gram-negative bacteria, plasmid-mediated resistance genes produce
proteins that bind to DNA gyrase and protect it from the action of quinolones. Also,
the binding affinity of quinolones can be decreased if there is mutation in DNA gyrase
or topoisomerase IV, that in turn cause decrease in the effectiveness of the drug.
Some bacteria are naturally resistant to certain antibiotics, for example, gram-negative
bacteria are resistant to most l-lactam antibiotics due to the enzyme B-lactamase.
Antibiotic resistance may also be acquired as a result of either genetic mutation or
horizontal gene transfer. Although mutations are rare, the spontaneous mutations in
the pathogen genome occur at a rate of
about 1 in 10 to 1 in 10 per chromosomal replication." The lifespans and
production of new generations can merely be of few hours, a de novo (new)
mutation in parent cell can quickly become an inherited mutation of widespread
prevalence, resulting in the microevolution of a fully resistant colony.
However, bacteria can also acquire resistance through transformation,
as in Streptococcus pneumoniae uptaking the naked fragments of
extracellular DNA containing antibiotic resistance genes to streptomycin;
through transduction as in the bacteriophage-mediated transfer of
tetracycline resistance genes between strains of S. pyogenes;
or through the gene transferring agents that are
produced by the host cell resembling the bacteriophage structure and are
capable of transferring DNA.
Antibiotic resistance can also be introduced
artificially into a microorganism through laboratory protocols, sometimes
used as a selectable marker to study the mechanisms of gene transfer or to
identify individuals that absorbed fragments of DNA that consisted of the
resistance gene or the gene of interest.
In recent years, the origin and spread
of resistance to - lactamases called carbapenemases, has become a major
health crisis. One such case is New Delhi Metallo-beta
lactamase 1 (NDM-1), an enzyme that makes bacteria resistant to a broad
range of beta-lactam antibiotics. The most common gram-negative bacteria
that produce this enzyme are Escherichia coli and Klebsiella pneumoniae,
but the gene for NDM-1 can spread from one strain of bacteria to another
by horizontal gene transfer.
What happens if you misuse antibiotics?
Antibiotic resistance is highly problematic not only in developing
countries, but is widely common in the developed world too.
It has severely hindered the ability to treat
infectious diseases. When first-line and then second-line antibiotic treatment
options are limited or unavailable due to resistance, healthcare providers are
forced to use antibiotics that prove to be more toxic to the patient and
consequently more expensive. Also, surgical operations rely on the
administration of antibiotics, prior and after the operation.
Without effective antibiotics, basic medical procedures and surgical
operations become risky.
In addition to causing deaths and preventing
basic infectious conditions to be treated, antibiotic and antimicrobial
resistance leads to steeper healthcare costs. Patients need to spend
more time in hospital in order to receive more expensive types of treatment.
Antibiotic Stewardship The appropriate use of antibiotics is often called
as "Antibiotic Stewardship. Many hospitals and medical associations have
implemented new diagnostic and treatment guidelines to ensure effective
treatments for bacterial infections and reduce inappropriate use of antibiotics.
Patients also plays a role in antibiotic stewardship. They may help to reduce the
development of antibiotic resistance.
Consuming antibiotics for a viral infection would otherwise not cure the
infection or may not give relief from symptoms,
and may promote antibiotic resistance.
If one consumes an antibiotic while having a viral infection,
the antibiotic attacks the natural flora in the body.
This misdirected treatment may then promote antibiotic-resistant
properties in bacteria that are harmless, or create an opportunity
for potentially harmful bacteria to replace the harmless ones.
Efforts to prevent such threats, public health strategies like immunization,
infection control, antibiotic stewardship, protecting the food supply and
reducing person-to-person spread through diagnosis,
treatment and education are practiced.
How can we prevent antibiotic resistance?
Combating superbugs and
antimicrobial resistance is a technical challenge that cannot be addressed
by health administrators alone. Misuse of antibiotics by medical practioners
and patients, as well as by the weak pharmaceutical regulatory mechanisms
in most developing countries also are the main issue. Preservation of the
efficacy of the life-saving and precious resource of antibiotics cannot be taken
lightly or left to a few individuals or experts. It is a global threat that requires
global efforts, if we are to avoid a reversion to the dreadful pre-antibiotic era,
which would be disastrous for poverty alleviation, development, and global
efforts to make the world a better and more healthy place.
