Antimicrobial resistance pathogens

In recent years, antimicrobial-resistant pathogens have been emerging in human medicine and spreading more rapidly than in previous decades. Treatment of... 

Empirical therapy should be directed at the most likely pathogen (s) for a specific patient, taking into account age, risk factors for infection (including underlying disease and immune dysfunction, vaccine history, and recent exposures), CSF Gram stain results, CSF antibiotic penetration, and local antimicrobial resistance patterns. 

Stratton, C. W. Antimicrobial resistance in respiratory tract pathogens. Expert Rev. Anti. Infect. Ther. 2004, 2, 641-647. 

Emerging infectious pathogens, increasing antimicrobial resistance, recognition of the long-term impact of diarrheal diseases and the appearance of diseases that decrease the host defense have heightened the necessity to develop new and more specific treatments and further... 

Multiresistant Escherichia coli have been selected by the use of broad-spectrum antimicrobials in both livestock and humans (36). The development of antimicrobial resistance in Escherichia coli creates problems due to the high propensity of these bacteria to disseminate antimicrobial resistance genes. Resistance genes have been traced from Escherichia coli in animals to Escherichia coli in humans. Escherichia coli 0157 H7 has been recently recognized as an important human pathogen (37). lire mode of its transmission is primarily through the food, but person-to-person transmission has been also identified in some day-care center and nursing home outbreaks (38). 

Additional studies, such as those conducted by the US Institute of Medicine Report (lOM) in 1988, also attempted to determine the impact of drug usage in food-producing animals on antimicrobial resistance of human pathogens, using penicillin and tetracycline on Salmonella as a model. The authors of this study attempted to describe the extent to which transfer of resistance factors occurred between human and animals and to define whether the risk to human therapy was enough to outweigh the benefits of a cost-effective food supply. The result of the lOM Report was that the information available to answer the question was insufficient. 

The ability of a light-drug combination to kill microorganisms is not a new idea and has been known for over 100 years [3]. In fact the concept of PDT was initiated in 1900 when Raab described the antimicrobial action of acridine and light on Paramecium species [4], Flowever, only recently has the search for alternative treatments for antibiotic-resistant pathogens stimulated the PACT development. 

DSC has also been used to study the effects of a wide variety of antimicrobial peptides on the thermotropic phase behavior of different lipid bilayers. These studies again are highly biologically relevant because the primary mode of action of most antimicrobial peptides is the perturbation and permeabilization of the lipid bilayers of the target membrane, and these agents have considerable promise as antibiotics, especially to treat multiple dmg-resistant pathogenic bacteria. Again, the reader should consult recent reviews for more information on this topic (30, 31). 

Resistance of pathogens to antimicrobial treatment is a major concern in veterinary medicine, just as in human medicine. Antimicrobial resistance negatively impacts both the current use and future development of pharmaceuticals for animals. For sick animals, antimicrobial resistance directly impairs the success of treatment to control disease. This can affect the prognosis and suffering for an individual animal and often the productivity, survival, and economic returns for an entire herd. Resistance may make it difficult to find effective, already approved drugs as active controls for preapproval clinical trials. The ability of resistant micro-organisms to move between humans and animals raises serious public health concerns. 

Antimicrobial pharmacodynamics have become a crucial consideration for the clinician during the selection of both empirical and pathogen-directed therapy in the current era of antimicrobial resistance. 

There are a number of methods in use that directly detect the production of antimicrobial resistance in pathogens. /3 -Lactamase production can be detected rapidly and easily in the clinical laboratory with the use of nitrocephin disks. Nitrocephin is a chromogenic cephalosporin derivative that changes color on hydrolysis by /3-lactamase. Colonies from a growing bacterial culture can be touched to a disk, with /S-lactamase production noted within a few minutes. Although rapid and reliable, this method is limited to the assessment of strains of staphylococci, enterococci, H. influenzae, Moraxella catarrhalis, and N. gorwrrhoeae. The nitrocephin disk also cannot detect /3-lactam... 

One must consider the type of surgery, intrinsic patient risk factors, the most commonly identified pathogenic organisms, institutional antimicrobial resistance patterns, and cost when choosing an antimicrobial agent for prophylaxis. 

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