Jornal de Biorremediação e Biodegradação

Abstrato

Antibiotics Sensitivity Patterns and Plasmid Profiles Analysis

Oyem, I. M

Antibiotics are a gaggle of naturally-occurring, semi-synthetic and/or chemically synthesized compounds with antimicrobial activity. They find wide application in human and veterinary medicine in the treatment and prevention of a number of diseases and as growth promoters in animal intensive industries. The resistance to a broad range of antibiotics by microorganisms is a major concern in modern medicine. Clinical infections, diseases and death caused by resistant bacteria are increasing by the day. Antibiotic resistance are often established and propagated in human and animal digestive systems. The spread of resistant strain within the gastro intestinal tract (GIT) is enabled by the co-occurrence of high levels of bacteria and sub-lethal doses of antibiotics. However, there are some uncertainties and speculation about environments such as sewage treatment plants (STPs) and aquatic environments in general, which provide enabling conditions for the establishment and propagation of antibiotics resistant bacteria. Effluent emanating from pharmaceutical manufacturing plants and waste water treatment facilities receiving wastewater from sewage, hospitals and veterinary clinic are a number of the notable sources through which antibiotics are released into the environment .Towards the end of the 20th century, several classes of antibiotics were discovered in sewage and sewage treatment plants (STPs). These include ß-lactams, trimethoprim, sulphonamides fluoroquinolones, macrolides, and tetracycline;. Many of those antibiotics find their way into sewage unchanged as they're not completely metabolized during therapeutic use. Various researchers have reported bacteriophage isolated from sewage carrying various lactamase genes, a simple route for disseminating antibiotic resistance among STP bacterial communities. Activated sludge tanks, trickling filters et al. STPs are samples of biological reactors that concentrate bacteria in conditions designed to encourage their proliferation and activity. They reduce viable concentration of faecal bacteria like coliforms and enterococci counting on the plant efficiency. However, relatively high number of bacteria still remains in STP effluents, up to 103 cfu/ml-1. Enterococci have been reported. Some of these bacteria carry antibiotics resistance genes especially in the influent. About 40% of the cultivable E. coli strains isolated from sewage were immune to one or more antibiotics and 9.8% were immune to quite three antibiotics. Various multi resistant plasmids harbouring transposons each carrying up to 10 different antibiotic resistance genes have been isolated from STPs. Besides health fears, there's an increasing concern about the potential ecological impacts from both the presence of antibiotics and resistant bacteria within the environment.