Microbiology - Microbes and Antibiotics

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Which of the two is used topically and which is used internally?: Nystatin - topically
Amphotericin B - internally
What is the metabolism of Abxs?: Abx -> blood, goes thru liver, it is conjugated where it is sent back into the blood; kidneys removed conjugated abx and put it into the urine
What are the modes of action of Abxs?: Inhibit cell wall synthesis, cell membrane fxn, inhibit bacterial 70s ribosomes, and affect DNA/RNA fxn
What is the goal of asepsis?: to prevent, eliminate or confine infection
What spectrum are Polymyxins?: narrow spectrum against G- bacteria
What are the phagocytic cells of inflammation?: Neutrophils and monocytes
What 4 things can we do for infection control?: Education of public
Technical development for proper dx
Survelliance during tests of microbes
Statutory Regulations of OTC drugs
What is antisepsis?: the process of destroying only vegetative pathogens on living tissue - mouthwash for teeth
What do anti-fungal agents work against?: against the eukaryotic fungi - yeasts and molds
Name several anti-viral agents.: Acyclovir / Zovirax for Herpes, Amantadine for Influenza A, Ribavirin for RSV, Interferon for hepatitis viruses
Sanitization is used to ...: reduce the # of microbes on inanimate surfaces
What are 4 methods of antisepsis?: boiling, US cleaning, radiation, chemical methods
How do Nystatin and Amphotericin work?: they inhibit the functioning of sterols in the eukaryotic cell membrane; since prokaryotic cell membranes don't have sterols, they don't work on bacterial growth in these cells
What is the most common macrolide?: Erythromycin
What is ethylene oxide active against?: both vegetative and spores; highly microbicidal
What can a disinfectant be used on and why?: It cannot be used on tissue due to it being too harsh of a chemical. It can be used on innominate objects - table, sinks, etc.
What soil bacteria do all the 70s inhibiting Abxs come from?: Streptomyces spp.
What are innate or non-specific resistance?: Species, intraspecies / racial, and individual resistance, sex, hormone balances
How does autoclaving kill microbes?: increased H20 content in protoplasm decreases the temperature necessary to denature all protein in microbes, killing them; 15# above atmospheric T
What is asepsis?: process of dettering the development of sepsis or the breakdown of tissue by microbes
How do these work more against fungal cell membranes than against human cell membranes?: Fungi, yeast, molds have more sterols in their cell membrane than we do
What spectrum are tetracyclines?: broad spectrum
What is antitoxin therapy?: used to neutralize toxins
What is the function of a disinfectant?: to destroy pathogens, to prevent infection.
What are bacteriocidal Abxs called that inhibit/kill the 70s ribosomes?: aminoglycosides
What are the side effects of chloramphenicol?: suppresses red bone marrow -> aplastic anemia
What is chemotherapy?: use of chemicals to rx disease; agents should be bacteriostatic or bacteriocidal; should be non-toxic to host
What is sterilization?: The process of killing or removing all life forms, esp. microbes, spores, and viruses. It is an absolute state.
How are polymyxins used and are they nephrotoxic?: used in ointments and yes, they are nephrotoxic
What are side effects of Abxs?: Allergy or hypersensitivity
Toxicity to use-such as Nephrotoxicity, Ototoxicity, Aplastic anemia, Tooth discoloration
Loss of normal microbial flora -> development of sec. infections
Why don't Abx have an effect on humans?: we don't have the peptidoglycan cell wall
Define disinfection.: It is the process of destroying only vege-non-pathogens.
Polymyxins come from which soil bacteria?: Bacillus polymyxa for polymyxin B
Bacillus colistinus for polymyxin E / colistin
What is the common trade name for Chloramphenicol?: Chloromycetin
What are two types of chemical degermination?: Using a -cide: that kills microbes
Using a -static: that inhibits or stops the growth multiplication of microbes - DOES NOT KILL !
What is the difference of medical and surgical asepsis?: medical asepsis is designed to keep objects, etc. free from pathogens while surgical is designed to prevent microbes from gaining access to pt.
What do these Abxs not have an effect on?: eukaryotic fungi, yeast, molds, viruses
Discuss hormone balance and resistance.: Estrogen up-regulates and progesterone down-regulates immune responses
Cortisone - low levels -> Addison's disease
high levels -> Cushing's disease
Blood sugar is playing field for bacterial growth
What is an antibiotic?: chemical compounds originally produced by mo in which small amounts inhibit or kill other mo's.
What is INH / isoniazide hydrazide ?: a antimetabolite for mycolic acid, used for rx of TB
What are the two anti-fungal agents and where do they come from?: Nystatin from Streptomyces noursei
Amphotericin B from Streptomyces nodosus
What is sulfa and sulfonamides?: an antimetabolite that is substituted for PABA that leads to stopping DNA synthesis; they are bacteriostatic
What is alkylation that is used with ethylene oxide?: it involves the replacement of H on organic moelcules with organic residues
What suffix do aminoglycosides end in ?: -mycin, -micin
What damage can these cause to the body?: Nephrotoxic and ototoxic
What is immunological prime?: 20-40 yos.
Why don't Abx have an effect on viruses and fungi?: They also lack to peptidoglycan cell walls.
What are the side effects of CA therapy?: Hair loss, dec. in lining of GI tract, Anemia, immune suppression, bruising
How are aminoglycosides given to patients?: by IM or IV
What are Sulfas used for?: UTIs, TB
How do soap/surfactants chemically disinfect?: it degerms skin by removing transient bacteria by emulsifying skin oil
What are the roles of aspirin and acetaminophen in fever reduction?: Aspirin inhibits PG synthesis and acetaminophen decreases PGs.
What spectrum are aminoglycosides?: broad spectrum vs. both G+ and G-
What are 2 origins of Abx resistance?: Chance mutation in bacterial chromosome
Plasmid transfer of abx resistance
How does dry heat kill microbes?: the high T coagulates cell proteins
What is Rifampin?: From soil bacteria Streptomyces mediterranei
Inhibits only bacterial exnyme that synthesizes RNA
Used to rx TB and meningitis
What is silver used for?: used to prevent opthalmia neonatuorum in newborns
What are the side effects of tetracyclines and how should you take them?: tooth discoloration in kids; don't take them with meals
What is Glutaraldehyde or Cidex?: a disinfectant related to formaldehyde
What is interferon?: a protein that leads to the production of TIP/transnational inhibitory protein which leads to the prevention of viral mRNA from replicating -> viral death
Degermination is to ...: remove transient microbes on the skin by mechanical and chemical means
What body part controls fever?: hypothalamus
What are the soil fungi and mold Abxs?: Penicillium spp. and Cephalosporium spp.
What are 4 ways of Abx resistance?: Bacterial enzymes inactivate the abx
Change in selective permeability of cell membrane
Bacteria develops other metabolic pathway to bypass the abx
Bacteria develops a smart metabolic enzyme that recognizes the metabolite and won't use it
How does US cleaning work?: it removes soil and deisintegrates bacterial cells
What spectrum are macrolides?: narrow against G+ and fragile G-
How does radiation kill microbes?: thymine dimmers which cause mutations and prevent DNA replication; used to sterilize non-filterable items
Which Abxs inhibit nucleic acids in bacteria and humans also?: Rifampin, CA therapy
What is copper used for?: used to control fungal and algal growth
What suffix do all tetracyclines end in?: -cycline
What is a broad and narrow spectrum Abx?: Broad = works against G+ and G-
Narrow = works against only G+ or G- BUT not both
What are 3 bacteriostatic Abxs that inhibit but not kill the 70s ribosome of prokaryotic bacteria?: Tetracyclines, Macrolides, Chlormphenicol
What are alkylating agents used for?: disinfecting or sterilizing
What is neomycin used in and what with ? Hint: triple Abx: Triple Abx with bacitracin (G+), polymyxin (G-), and neomycin (G+ and G- 70s ribosomes)
What are the soil bacteria Abxs?: Bacillus spp., Streptomyces spp. - source of -mycins Abx
Are chloramphenicol broad or narrow spectrum?: broad
What 5 things are Abx resistance associated with?: 1. Incr. death toll
2. Incr. hospital stays
3. Incr. direct & indirect $$
4. Prolonged periods of infection
5. Incr. opporunities for spread of infection to others
What are antimetabolites?: laboratory made chemicals that are substituted for the normal cell metabolites that leads to stopping bacterial metabolism
What are methods of chemical disinfection?: Detergents damage lipid cell membrane
Phenols coagulate and denature protein
alkylating agents interact with active sites of enzymes
Chlorine/peroxide oxidize -SH groups of enzymes -> nonfunctional
What is the inflammatory response?: PGs are made by all cells in body; they dialate capillaries and arteries to allow blood into damaged area
What is a mechanical means of degermination?: proper cleaning and scrubbing first!
What is penicillin with a capital letter name?: Penicillin with side group in a unique compound
How does ETOH chemically disinfect?: denatures proteins, dissolves cell membrane DOES NOT KILL Spores !
What is natural penicillin with a side group?: orig. narrow spectrum v. G+ but with side group increase spectrum of activity therefore incr. to also include G- also.
What Abx do cephlosporins include?: All abx that sound like "cephalo" Keflex, Ceclor
How do cephalosporins work?: inhibit cell wall synthesis
How does Bacitracin work?: inhibits bact. cell wall sythesis
Which Abxs inhibit the synthesis of the bacterial cell wall when binary fission occurs?: Penicillins, Cephalosporins, Bacitracins
Where does Bacitracin come from?: soil Bacillus spp.
Discuss the Penicillin Abx group.: Includes all abx ending in -cillin
Produced by Penicillium spp.
Semi-sythetic comm. production
Natural penicillin G is unstable - must be given IM
How might natural penicillin be destroyed?: by plasmids that produce penicillinase that attacks the B-lactam ring on penicillin
Which Abxs inhibit cell membrane function?: Polymyxins, Anti-fungal agents; these damage the membranes of prokaryotic bacteria, eukaryotic yeast and fungi and human cells but have not effect on viruses
What is penicillin with a lower case name?: Generic penicillin: cheaper, just as good, taste and texture might not be as good
Where do natural cephalosporins come from: soil Cephalosoprium spp. molds - semi-synthetic comm. production
What spectrum is Bacitracin?: Narrow Spectrum v. G+ with thick outer peptidoglycan cell wall
What are the structure of cephalosporins resistant to and what is their spectrum coverage?: penicillinase; broader than penicillin
How do you use Bacitracin?: Topically only - it is nephrotoxic - damages the kidneys

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