microNotes1 - Differences Eukaryote Prokaryote Drugs...

Unformatted text preview: Differences Eukaryote Prokaryote Drugs Nuclear Membrane Yes No Organelles Bound Unbound Digestive vacuoles Yes No Chromosomes Multiple Single DNA gyrase can be targeted with quinolones like ciprofloxacin Membrane sterols Yes No Peptidoglycan No Yes Penicillins, cephalosporins Ribosomes 80s 70s Aminoglycosides, Macrolides M i c r o b io lo g y B a s i c s Prion Virus Bacteria Fungus Parasite Cells No No Yes Yes Yes Nucleic Acid No RNA/DNA RNA and DNA RNA and DNA RNA and DNA Nucleus None None Prokaryotic Eukaryotic Eukaryotic Ribosomes None None 70s 80s 80s Mitochondria None None None Yes Yes Outer Surface None Protein capsid Envelope Rigid wall Peptidoglycan Rigid wall Chitin Flexible membrane Replication Aggregates Requires host Binary fission Budding or mitosis Mitosis Functions of normal flora •Prevent colonization and infection with pathogens •Produce B vitamins and Vitamin K in the intestine •Deconjugate bile acids Typhoid Mary: first person identified as a healthy carrier of Salmonella typhi in the United States. e infected 75 people over the course of 7 years Site Normal Flora Problem Colonizers Skin • S. epidermidis • Diptheroids • Proprionobacterium acnes • Candida • S. Aureus • Pseudomonas aeruginosa Nose • S. epidermis • Diptheroids • Streptococci • S. Aureus • MRSA Humans normally have permanent, nonpathogenic resident bacteria and yeast on skin and mucosa. Their numbers are about 10 times the number of human cells. The blood, lower respiratory tract, CSF, pleural fluid, peritoneal fluid, and urine are sterile and do not contain any normal flora. Nile Law : California state law that requires the screening of all high-risk patients for MRSA. High-risk criteria include: inpatient surgery, burn, ICU, dialysis, hospitalized or nursing home She infected 75 people over the course of 7 years as a cook and was quarantined for 26 years. Mouth • S. viridans • Bacteroides • Fusobacterium • Streptococcus mutans • Porphyromonas gingivalis Throat • S. viridans • Neisseria spp. • Haemophilus spp. • S. pyogenies (Group A) • Meningococci Colon • Bacteroides fragilis • Enterobacteriaecae • Lactobacillus • Enterococci • Clostridium • C. difficile • Vancomycin-resistant enterococci Vagina • Lactobacillus • Streptococci • B. Fragilis • Enterobacteriacae • Candida • Group B Streptococci Clostridium perfingins from the normal bowel flora can cause myonecrosis if inoculated into an anaerobic environment in a wound. Attachment Colonization Invasion Evasion of host defenses Host damage and Infection Steps in Microbial Pathogenesis Selecting antibiotics: choose an antibiotic to which the pathogen is likely sensitive, but which has the most limited spectrum so as to limit the development of resistance. G e n e r a l B a c t e r ia F e a t u r Gram Stain: Gram positive cells have a thick layer of peptidoglycan, which serves as a barrier to lipid decolorizing solvents. Since the cells cannot be decolorized, they remain...
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