control of microbes in vivo

• use of any chemicals in treating a disease

  chemotherapy
• agent or drug used to treat diseases

  chemotherapeutic agent
• used to treat infectious disease either by inhibiting or killing pathogens 


  antimicrobial agents
• used to treat bacterial disease

  antibacterial agent
• used to treat fungal infections/diseases

  antifungal agents
• used to treat protozoal disease

  antiprotozoal agents
• used to treat viral infections

  antiviral agents
• used to kill growth of other microbes produced by microbes themselves

  antibiotic
• chemically modified to kill wider varieties of pathogens

  semisynthetic antibiotics
• who was the person to discover penicillin?

  alexander flemming
• characteristics of antimicrobial agent

  • kills growth of pathogens
  • cost no damage to the host
  • cost no allergic reaction to the host
  • stable
  • remains in specific tissues
  • kills pathogens before becoming resistant to it
• 5 common mechanisms of action of antimicrobial agents

  • inhibitions of cell wall synthesis
  • damage to the cell membrane
  • inhibition of nucleic acid synthesis (DNA and RNA)
  • inhibition of protein synthesis
  • inhibition of enzyme activity
• antibacterial agents

  • bacteriostatic drugs
  • sulfonamide drugs
• inhibits the growth of bacteria

  bacteriostatic drugs
• kills growth of bacteria

  bactericidal drugs
• inhibits production of folic acid in bacteria that requires p aminobenzoic acid for synthesis


  sulfonamide drugs
• have thick layers of peptidoglycan with reddish pink stains

  gram negative bacteria
• destroys only the gram negative bacteria with narrow spectrum antibiotics 


  colistin and nalidixic acid
• antibiotics that are both destructive to gram positive and gram negative bacteria

  broad spectrum antibiotics and multidrug therapy
• major categories of antibacterial agents

  • penicillins
  • cephalosporins
  • tetracyclines
  • aminoglycosides
  • macrolides
  • fluoroquinolones
• 2 microbes acting together with a greater effect on either one acting alone

  synergism
• 2 drugs working against each other; not good

  antagonism
• how does antifungal agents in 3 ways?

  • binding with cell membrane sterols
  • interfering with sterol synthesis
  • blocking mitosis or nucleic acid synthesis
• they are both tend to be more toxic to the patient because they are eukaryotic cells

  antiprotozoal and antifungal agents
• agent that is toxic to the host

  antiprotozoal
• newest weapon in antimicrobial methodology and are difficult to develop because they are made within the host cells themselves

  antiviral agent
• used to treat HIV patients

  cocktails
• microbes that have become resistant to one or more antimicrobial agents and infections that are caused by these are difficult to treat

  superbugs
• example of bacterial superbugs

  • methicillin-resistant staphylococcus aureus (MRSA)
  • enterococcus spp. (vre)
  • multidrug resistant mycobacterium tuberculosis (mdr tb)
• lack the specific target site for the drug or is unable to cross the organisms cell wall, thus not reaching its site of action.

  intrinsic resistance
• bacteria that is once susceptible to a particular drug that is now resistant

  acquired resistance
• called drug binding site

  proteins
• plasmid containing multiple genes for a drug resistance

  resistance factor (r-factor)
• bacteria that became resistant by developing multidrug resistance (mrd) pumps

  mdr transporters orr efflux pumps
• enables the cells to pump out drugs before they can damage or kill the cell

  mdr pumps
• bacteria can acquire resistance to antimicrobial agents by what?

  chromosomal mutation and/or acquisition of new genes by transduction, transformation or conjugation
• present in every penicillin and cephalosporin molecules

  b lactamase
• other term of 'garage' in a double-ringed structure

  b-lactam ring
• 2 types of b-lactamase

  penicillinases and cephalosporinases
• strategies against war against drug resistance:

  • education of health care professionals
  • physicians should not be pressured by patients
  • good infection control in health care professionals