[debram]

Antibiotics came as a boon to human civilization with invent of the Penicillin that saved a million lives. Antibiotics are chemotherapeutic agent that abolishes or retards growth of microbe, such as fungi, bacteria or protozoa. Classically an antibiotic is defined as a compound produced by one microorganism that inhibits the growth of another microorganism. This definition over the years has been elaborated to include synthetic and semi-synthetic agents. Although not synonymous antibiotics are also referred as antimicrobials or chemotherapeutics. As, for example, antimicrobials may be effective against viruses. The term ‘chemotherapeutical” is also known as anti-neoplastic drugs referred to compounds used for the treating disease like cancer. The term, ‘‘chemotherapeutical” may also refer to antibiotics in which case it is known as antibacterial chemotherapy. Currently there are nearly 250 different chemical entities registered for its application in medicine and veterinary medicine. The first antibiotic, Penicillin was of natural origin produced by fungi Penicillium, and streptomycin by bacteria Streptomyces. In recent times antibiotic such as sulfa drugs (e.g. sulfamethoxazole) are being synthesized chemically or by chemically modifying compounds of natural origin. Some antibiotics are relatively small molecules with molecular weight less than 1000 Da.

In contrast to the desired properties and affects the therapeutic application of antibiotics, are often disadvantageous for target and non-target organisms present in the environment

Although over the decades antibiotic have been used in large quantities, the existence of these substances in the environment has gained little notice. A more complex investigation of antibiotic substances has been undertaken only in recent years, so as to assess the environmental risks they may pose. It was found that the concentrations of antibiotics measured in hospital effluents, municipal sewage, surface and ground water, influents and effluents of STPs, are mostly in the same range, respectively.
Although an increasing number of investigations covering input, fate, occurrence and effect of antibiotics have been published over the last decades, but, despite the numerous studies performed there is still a lack of proper understanding and knowledge about the existence and effects of antibiotic agents in the aquatic environment. Therefore, extensive and thorough research is needed to explore certain significant issues and questions related to these substances that are still open and must be properly handled in the future for a better understanding of the risk associated and behavior of antibiotics in the environment. I hope this reply addresses the present state of knowledge relating to the occurrence and effects of antibiotics in the aquatic environment.