Anti-Fungal Compounds.ppt

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1、Anti-Fungal Compounds,Eukaryotic pathogens Similar cell structure and functionMany fungi are opportunistic Fungal infections on the rise Most have detoxification systems,Fungal infections (mycoses) may be: Cutaneous Dermatophytic Subcutaneous Systemic,Antifungal Disruption of Cell Membrane,many targ

2、et membrane sterols (ergosterol)Polyenes Produced by Streptomyces Toxicity is a serious issue Amphotericin B Used for systemic mycoses Nystatin Effective topical treatment for cutaneous and subcutaneous mycoses,Azoles Synthetic drugs Fluconazole & Ketoconazole Used to treat systemic mycoses, dermato

3、phytic infections, cutaneous mycoses,Anti-fungal Inhibition of Cell Wall Synthesis,Inhibition of -glucan results in incomplete cell wall Echinocandins Caspofungin used against many opportunistic mycoses Candida, Aspergillus and Pneumocystis,Anti-fungal Inhibition of Nucleic Acids,Work on specific en

4、zymes not in mammalian cellsFluorocytocine Synthetic drug Cytosine analog interferes with RNA synthesis Serious toxicity issues Used to treat systemic yeast infections,Other Anti-fungals,Griseofulvin Given orally; reaches target site through sweat Inhibits cell divisionTolnaftate Used for athletes f

5、oot; action unknown,Nitroimidazoles Metronidazole Effective against Trichomonas and Girardia Effective against anaerobic bacteria Activated by anaerobic metabolism Alters DNA Side effect black, hairy tongue Causes birth defects; passed in breast milk,Anti-protozoan Inhibition of Nucleic Acids,Nifurt

6、imox Effective against Trypanosoma Interferes with electron transport Mild gastrointestinal upset,Anti-protozoan Inhibition of Necessary Metabolites,Quinine and Quinolines Isolated from a Peruvian tree; replaced with synthetic versions Exact mechanism of action unknown- inhibits protozoan metabolism

7、 Chloroquine & mefloquine Malaria treatment,Other Anti-protozoan Drugs,Niclosamide Prevents ATP generation Tapeworms Praziquantel Causes tetanic contractions Flukes Ivermectin Paralyzes worm Intestinal roundworms and tissue nematodes,Anti-helminthic Drugs,Available antiviral drugs effective specific

8、 type of virus None eliminate latent virusesAttachment Un-coating Nucleic acid synthesis Protein synthesis Maturation Release,Anti-viral Drugs,Nucleoside/nucleotide analogs Results in an increased mutation rate Azidothymidine (AZT) HIVRibavirin Flu, respiratory syncytial virus, hepatitis Acyclovir R

9、educes frequency and severity of herpes outbreaks Herpes viruses,Anti-viral Inhibition of Nucleic Acids,Indinavir Protease inhibitor- inhibit viral assembly/release HIVAmantadine Inhibit viral un-coating FluZanamivar Neuraminidase inhibitor- inhibit viral attachment Flu,Anti-viral Inhibition of Vira

10、l Proteins,Mutations lead to resistance Resistance is transferred between cells Resistance genes are often on plasmids or transposons Multi-drug-resistant pathogens Cross resistance,Anti-microbial Resistance,Mechanisms of antibiotic resistance 1. Drug inactivating enzymes 2. Decreased uptake of the

11、drug 3. Alteration of target moleculeIncreased elimination of the drugProtecting the target,Misuse selects for resistant mutants Using outdated, weakened antibiotics Using antibiotics for inappropriate conditions Use of antibiotics in animal feed Failure to complete the prescribed regimen,Slowing emergence and spread of resistance Responsibilities of healthcare workers Increase efforts to prescribe antibiotics for specific organisms Educate patients on proper use of antibiotics SynergismResponsibilities of patients Follow instructions carefully Complete prescribed course of treatment,