To Access Multi Drugs Resistance Status and AmpC Production in Isolates of Pseudomonas spp. and Acinetobacter spp. from ICU

Abstract

Multidrug resistance in bacteria may be generated by one of two mechanisms. First, these bacteria may accumulate multiple genes, each coding for resistance to a single drug, within a single cell. This accumulation occurs typically on resistance (R) plasmids. Second, multidrug resistance may also occur by the increased expression of genes that code for multidrug efflux pumps, extruding a wide range of drugs. This review discusses our current knowledge on the molecular mechanisms involved in both types of resistance. some strains have become resistant to practically all of the commonly available agents. A notorious case is the methicillin-resistant Staphylococcus aureus (MRSA), which is resistant not only to methicillin (which was developed to fight against penicillinase-producing S. aureus) but usually also to aminoglycosides, macrolides, tetracycline, chloramphenicol, and lincosamides. Such strains are also resistant to disinfectants, and MRSA can act as a major source of hospital-acquired infections. Pseudomonas is a genus of Gram-negative, Gammaproteobacteria, belonging to the family Pseudomonadaceae and containing 191 described species. The members of the genus demonstrate a great deal of metabolic diversity and consequently are able to colonize a wide range of niches. Their ease of culture in vitro and availability of an increasing number of Pseudomonas strain genome sequences has made the genus an excellent focus for scientific research; the best studied species include P. aeruginosa in its role as an opportunistic human pathogen, the plant pathogen P. syringae, the soil bacterium P. putida, and the plant growth-promoting P. fluorescens, P. lini, P. migulae, and P. graminis. Most Pseudomonas spp. is naturally resistant to penicillin and the majority of related β-lactam antibiotics, but a number are sensitive to piperacillin, imipenem, ticarcillin, or ciprofloxacin. Acinetobacter is a genus of gram-negative bacteria belonging to the wider class of Gammaproteobacteria. Acinetobacter species are oxidase-negative, exhibit twitching motility, and occur in pairs under magnification. They are important soil organisms, where they contribute to the mineralization of, for example, aromatic compounds. Acinetobacter species are a key source of infection in debilitated patients in the hospital, in particular the species Acinetobacter baumannii. Species of the genus Acinetobacter are strictly aerobic, non-fermentative, Gram- negative bacilli. They show mostly a coccobacillary morphology on nonselective agar. Rods predominate in fluid media, especially during early growth.