We are all know that bacteria are prokaryotic unicellular micro-organism. They are found everywhere from favourable to unfavourable conditions. Bacteria are both harmful as well as beneficial for us. Usually harmful bacteria are termed as bugs. These bugs cause a lots of infectious diseases in human beings. But a new category of bugs has been introduced among us called as superbugs. It is a new category of bacteria which is more advanced than general infectious bacteria and more disease causing capacity and highly resistant to classical antibiotics to modern antibiotics. They affect new born babies as well as grown ups . Now our world suffers from superbugs infection . Developed countries as well as developing countries to regime a global problem in 21th century.
Reason : Antibiotic overuse and misuse
The superbugs are modified form of bacteria which previously caused infectious disease among human beings. The evolution of superbugs has been observed during the time of discovery of antibiotic or post antibiotic era . Antibiotic play a central role in evolution of superbugs. The first antibiotic penicillin was discovered in 1928 by Sir Alexander Fleming. After this many classes of antibiotics has been discovered for treatment of infectious diseases .Antibiotics are not only used for the treatment of infectious diseases , but also for production of livestocks and their growth and treatment for infectious disease in cattles. Misuse and overuse of the antibiotics for disease treatment led to evolution of antibiotic resistant bacteria or superbugs. It means superbugs are not easy to kill or suppress using antibiotics. Some superbugs are resistant to many antibiotic drugs called as MDR or multidrug resistant. But some are specifically for single drug resistant.
In the context of first discovered antibiotic after successful outcome Sir Alexander Fleming said that
“ the time may come when penicillin can be bought by anyone in the shop. There is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.”
Alexander Fleming at his 1945 Nobel prize lecture.
Due to the overuse and misuse of antibiotics , our intestinal micro-biome get affected and again by again using the antibiotics, our beneficial intestinal bacteria becomes antibiotic resistant by antibiotic selection pressure(SEP) such as Escherichia coli. Not only this other disease causing bacteria mutated within micro-biome and they are able to exchange genetic material or gene that make them antibiotic resistant.
Category of antibiotics
To date scientist developed and discovered the many antibiotics and all antibiotics are categorized into 10 main classes according to U.S. Centre for disease control and prevention (CDC). These are-
Class of antibiotics
Types of superbugs
According to the U.S. Centre for disease control and prevention (CDC) , some superbugs are most common infection problems and other considered urgent or serious threats-
Most common superbugs
A . Clostridium difficile– CDC considered as urgent threat.
B. MRSA- Methicillin resistant Staphylococcus aureus
Can cause flesh eating disease , considered a serious threat by the CDC.
C. VRE– Vancomycin resistant entericocci
Can cause sepsis , meningitis or pneumonia. CDC considered as serious threat.
Other urgent threat
A . CRE– Carbapenam resistant enterobacteria . it includes Klebsiella and E. coli can cause blood stream infections and pneumonia .
B . Neisseria gonorrhoerae – sexually transmitted disease that can lead to chronic pain . infertility in men and women and life threading complications.
Other serious threats
A . ESBL( Extended – spectrum beta lactamase )- Can cause intestinal , urinary , or respiratory symptoms.
B . Shigella, Camylobactor , Salmonella – drug resistant strains of bacteria cause food borne illness.
Mechanisms of antibiotic resistance
Bacteria resist the effects of antibiotics by using the following genetic strategies , with thousands of variations-
Producing destructive enzymes to neutralize antibiotics;
Modifying antimicrobial targets by mutation , so that drugs cannot recognize them;
Removing antimicrobial agents by pumping them out(drug efflux pump);
Preventing antibiotics from creating a “biofilm” or otherwise reducing permeability;and
Creating bypass that allow bacteria to function without the enzymes targeted by antibiotics.
NDM-1 Superbugs : World attention towards India
NDM-1 stands for New Delhi metalloprotein beta lactamse -1 is an enzyme that makes bacteria resistant to broad range of beta lactam antibiotics (penicillin) . NDM-1 coding gene present in bacteria to becomes superbugs. NDM-1 was first detected in Klebsiella penumoniae isolated from a Swedish patient of India (New Delhi) in 2008. The most bacteria that make this enzyme are gram negative such as E.coli and Klebsiella pneumoniae . Gene responsible for NDM-1 can spread from strain to other strain of bacteria by horizontal gene transfer. NDM-1 able to confer resistance to all available beta – lactam antibiotics. NDM-1 found in Asiatic countries as well as European countries and united states of America. Most of the countries of Europe and U.S.A claimed on India for Spreading and origin of NDM-1 superbugs. It is most dangerous and life threating superbugs . On the basis of survey most of the developing countries used high amount of antibiotics for both disease treatment and meat production In livestock. Our India is the largest antibiotic consuming country in the world. Peoples of the India used antibiotics for complex to simple diseases or even general fever without the prescription of doctors. In India antibiotics are bought by every category of the people. Because antibiotics are inexpensive as well as easily available . Person who uses huge amount of antibiotics they are highly resistant to antibiotics. Even fifth generation of the antibiotics are fail to treat of infectious diseases according to doctors report. The NDM-1 is not only found in the human micro-biome , but also has identified in environmental sample from water sources in India and Vietnam , indicating that the gene is present in both community and hospital ward. Superbugs are global problem and in the future uncountable people will die in next 2050 by Superbugs attacks.