Microbial diseases antimicrobial resistance

Tikofsky, L.L., Barlow, J.W., Santisteban, C. and Schukken, Y.H. 2003. A comparison of antimicrobial susceptibility patterns for Staphylococcus aureus in organic and conventional dairy herds. Microbial Drug Resistance-Mechanisms Epidemiology and Disease 9 S39-S45. 

Discovery and development of new antibiotics are in critical demand to combat infectious diseases caused by microbial pathogens and rapid spreading of antibiotic resistance. The add-mix-measure format of the BacTiter-Glo Assay can be easily adapted for high-throughput screening. In this report, we describe the use of BacTiter-Glo Assay to screen and evaluate antimicrobial compounds. 

The first quinolone, nalidixic acid, was isolated as a byproduct of the synthesis of chloroquine. It has been available for the treatment of urinary tract infections for many years. The introduction of fluorinated 4-quinolones, such as ciprofloxacin (Cipro), moxifloxacin (Avelox), and gatifloxacin (Tequin) represents a particularly important therapeutic advance because these agents have broad antimicrobial activity and are effective after oral administration for the treatment of a wide variety of infectious diseases. Relatively few side effects appear to accompany the use of these fluoroquinolones, and microbial resistance to their action does not develop rapidly. Rare and potentially fatal side effects, however, have resulted in the withdrawal from the market of temafloxacin (immune hemolytic anemia), trovafloxacin... 

Because of a significant decrease in the pace of novel anti-infective discovery, increased regulatory constraints, and greater profits to be made by the use of medications for chronic conditions, there is presently a decreased research emphasis on antimicrobial agents. This coincides with a dramatic increase in microbial resistance to chemotherapy, that portends a bleak future in which humankind may once again face infectious diseases with few available countermeasures. 

The presence of antimicrobial drug residues in the edible tissues can cause allergies, toxic effects, changes in the intestinal microbial fauna and acquisition of drug resistance. Chloramphenicol residues in food consumed by humans can even result in aplastic anemia, which causes very serious bone marrow diseases. Nitrofuran antibiotics are known to cause cancer and many other diseases. It is for this reason that most countries that import fish products have banned the use of certain antibiotics (Sanandakumar, 2002). 

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