Have you ever think about the germs that around you everyday make your alive or die!

I know if i mention about the germ you might focus only about it bad point. Yes in fact, Some of them are good and some are bad. Now I want to widen your knowledge about those little tiny things. You know! Microbes are so cute is you guy look deeply in it and try to understand about those life. It was like a miracle to found out about it. Let's start take a tour with me. Close your eyes and think through the following: inside your intestines, in your mouth and on your skin, there inside more than 100 000 000 000 000 microbial cells-100-fold more than the numbers of cells that make up the human body. We are not conscious of these colleagues any more than we are conscious of passing them round every time we shake hands, speak or touch a surface. Inoculation with just one microbes of the wrong type in the wrong way may kill you, yet we tolerate and indeed thrive on constant appropriate exposure to this unseen world. 

Because microbes are generally hidden from our senses, an appreciation of microbiology and infection demands imagination. Our forebears who established the discipline lavished imagination on the problems they studied. Sadly it is lack of imagination that that now underpins serious problem such as hospital-acquired infection and antibiotic resistance. 

Hard-won advances in microbiology have transformed the diagnosis, prevention and cure of infection and have made key contributions to improved human health and a doubling in life expectancy. The conquest of epidemic and fatal infections has sometimes seemed so conclusive that infections maybe dismissed as of minor concern to modern doctors in wealthy countries. However, infection is far from defeated. In resource-poor countries, an estimated 10 millions young children die each year from the effects of infectious diarrhea, measles, malaria, tetanus, diphtheria and whooping cough alone. Many other classical scourges, such tuberculosis, cholera, typhoid and leprosy, continue to take their role. Although we have the potential to prevent nearly all of those deaths, political and social issues constantly hinder progress, and more effective and economic means of delivery provide a constant challenge. 

Even in wealthy nations, infections is still extremely common: at least a quarter of all illness for which patients consult their doctors in the UK are infective and around one in ten patients acquired infection while in hospital, sometimes with multi resistant organisms. Global communications and changes in production systems, particularly those affecting food, can have a profound effect on the spread of infectious diseases. The emergence of human immunodeficiency virus (HIV), new-variant Creutzfeldt-Jakob disease (CJD), severe acute respiratory syndrome (SARS), and avian influenza illustrate the need for continued vigilance. 

The relative freedom of wealthy societies from fatal infections has been won through great struggles, which are all too easily forgotten. As generations grow up without the experience of loosing friends and relatives through infection. So the balance of perceived risk and benefit looks difference. So now, in addition to the old threats, which are ever present, we constantly face pressure to drop or modify measures such as public immunization. A historical understanding of infection status as is knowledge of contemporary progress. 

In summary: 

- Microbes are too small to be seen directly and special method are needed to investigate them. In daily life and in clinical practice we are forced to use our imagination to understand how our behavior influences and is influenced by them. 

- Infections and microbes were considered as separate phenomena until the late nineteenth century when pasteur reconciled previous observations on the physical requirements for the transmission of infection with the nature of microbes and established the necessity of a chain of transmission in infection. 

- Some infections can be prevented by interrupting transmission and/or by immunization. 

- The role of specific microbes in specific infective conditions maybe established by propagating the microbe in pure laboratory culture and subsequently reproducing the disease in a suitable model. 

- Molecular biology has opened up new ways of identifying microbes and establish microbes and establishing causality in infection. 

- Transmission of infection  is related to the resevior, immediate source and mode of transmission of the causal agent. 

- Approximately 100 000 000 000 000 bacterial, fungal, and protozoan cells live on and in healthy human bodies. Most are harmless or even beneficial. Those that cause disease in otherwise healthy individuals are termed pathogens. The normal flora or microbiota constitutes the reservoir and immediate source for endogenous infection. Infections are termed endogenous infections. 

- Many infections can now be treated with antimicrobial agents that posses selective toxicity. None the less, infection remains the most common cause of morbidly and premature death in the world.