ANTIBIOTIC CLASSES AND ANTIBIOTIC SUSCEPTIBILITY OF BACTERIAL ISOLATES FROM SELECTED POULTRY; A MINI REVIEW

Abstract

Antibiotics are drugs that kill (bactericidal) or slow (bacteriostatic) the growth of bacteria. Broad-spectrum antibiotics treat a wide range of infections, while narrow- spectrum antibiotics are effective against only a few types of bacteria. Antibiotics are very essential in the treatment of human and animal infections caused by bacteria. They are also important for the prevention of secondary infections. Despite the importance of antibiotics, their uses have received much criticism from the consumers, responsible stakeholders and policy makers. Antibiotics have evolved over the years with relatively unprecedented resistant patterns. Various classes of antibiotics such as aminoglycosides, cephalosporins, macrolides, quinolones, tetracyclines and many more have also evolved. For instance cephalosporins have evolved from first generation to the fifth generation. These antibiotic groups use different mechanisms in combating bacteria. These mechanisms include disrupting the formation of bacteria cell wall (penicillins, cephalosporins), interfering with the synthesis of bacteria DNA (fluoroquinolones), inhibiting the bacterial protein synthesis (tetracycline) and destroying protein synthesis (macrolides, aminoglycosides). Bacterial isolates from poultry exhibit different resistance patterns. At times the resistance patterns may be the same or similar among bacterial isolates. The differences in resistance patterns are widely due to factors which include differences in geographical locations, particular bacteria species involved, the animal production systems, the extent to which antibiotics are used, sampling techniques and period of sampling