Understanding Infectious Diseases and Antibiotics

1. UNIT 15 Antibiotic Agents

2. Key Terms Antiseptic Bacteria Bactericidal Bacteriostatic Beta-lactamase Disinfectant Infection Microorganism Pathogen

3. Infectious Disease Viruses cause 50% of all infectious diseases Infectious disease is one of the world’s top three killers (with heart ailments and cancer) (continues)

4. Infectious Disease Factors for infection Organism in sufficient number Power and degree of pathogenicity Environmental conditions Portal of exit Mode of transmission Susceptible host (continues)

5. Infectious Disease Defense mechanisms Body equipped with built-in defense Intact skin Secretions White blood cells Body chemicals Antibodies

6. Deadly Infection Factors International travel and food shipment Population growth Changes in growing and handling of food Poor public health infrastructure Immunosuppression Increased use of antibiotics in humans and livestock Resistance to antibiotics

7. MRSA Bacteria is resistant to antibiotics Frequently occur in people in health care centers with compromised immune systems (CA)-MRSA: usually skin infections 5 Cs: crowding, frequent skin-to-skin contact, compromised skin, contaminated items, lack of cleanliness

8. C. difficile Majority occur in health care settings Antibiotic resistant Toxins attack intestinal lining Treat with Flagyl or Vancocin

9. Escherichia coli Normally found in human intestine May cause diarrhea, hemorrhagic colitis, and HUS (continues)

10. Escherichia coli Contamination by Ground beef Fruits and vegetables Swimming pools, hot tubs Did you know? E. coli is the most common cause of UTI in women.

11. Salmonellosis Infects intestines and blood Most recover without treatment, but some require hospitalization May cause diarrhea, fever, abdominal cramps; usually lasts 4 to 7 days 40,000 cases per year; 1,000 deaths per year (continues)

12. Salmonellosis Usually foodborne Raw poultry Eggs Unpasteurized milk and cheese Infected food handlers May be found in animal feces (continues)

13. Salmonellosis Discussion Questions: Why is salmonellosismore common in summer than in winter? What can be done to prevent infection with E. coli or salmonellosis?

14. Campylobacteriosis Most common bacterial cause of diarrhea in the United States Symptoms Diarrhea, may be bloody Cramping Nausea and vomiting Fever (continues)

15. Campylobacteriosis Transmission Contaminated food, water, or milk Undercooked poultry Cross-contamination from raw to ready-to-eat food

16. SARS SARS: Severe acute respiratory syndrome First reported in Asia in February 2003 8,098 diagnosed; 744 died Viral infection spread through droplets Possibly airborne-spread (continues)

17. SARS Symptoms High fever Headache Overall discomfort; body aches Dry cough Diarrhea Pneumonia develops in most of those infected

18. Streptococcus Group B Most common cause of sepsis and meningitis in newborns Group A Found in throat and on skin May cause strep throat, impetigo, necrotizing fasciitis, or streptococcal toxic shock syndrome (STSS)

19. Group A Streptococcus (GAS) Necrotizing fasciitis: “flesh-eating bacteria” Destroys muscle, fat, and skin 20% of patients die STSS Causes hypotension and organ failure More than 50% of patients die

20. Minimizing Your Risk Healthy diet Don’t smoke Reduce stress Exercise Adequate sleep Current immunizations (continues)

21. Minimizing Your Risk Adequate fluid intake Positive attitude Good hygiene Don’t share food or drink with others Keep hands away from face

22. Warning! Seek medical attention immediately Sudden high fever, violent chills, or confusion Infection seems to be spreading Injury becomes extremely painful or enlarges Redness or blistering of skin Pain in muscles Enlarged lymph nodes Crescendo pain in surgical incision High fever, vomiting, lethargy, inflammation in other areas, or swollen areas of body after fourth day of chickenpox Pregnant women with flu-like symptoms

23. Antibiotics Used to treat bacterial infections in animals, plants, humans Bacteria Gram-positive: retains gentian violet stain Gram-negative: does not retain gentian violet stain Acid-fast: retains stain even when treated with acid (continues)

24. Antibiotics Discussion Questions: How can keeping a positive attitude help prevent infection? If patients are no longer contagious after 24 hours of antibiotics, why must they continue to take medication for several days?

25. Classification of Antibiotics Broad-spectrum Many kinds of microorganisms Narrow-spectrum Limited types of microorganisms Extended-spectrum Covers Pseudomonas, Enterobacter, and Proteus species

26. Administration of Antibiotics Check for allergies; note in red Culture and sensitivity should be performed BEFORE starting antibiotics Discussion Question: Why would you not perform a C&S after antibiotics have been administered?

27. Effective Antibiotics Must be harmless to blood, liver, bone marrow, and kidneys Low possibility of toxicity Effective against invading microorganism Must be more beneficial than harmful

28. Adverse Reactions to Antibiotics Hypersensitivity Organ toxicity Superinfection Antibiotic overuse Results in drug-resistant strains of bacteria

29. Antibiotic Resistance Use of antibiotics for viral infections increases antibiotic resistance Antibiotics are overprescribed Hand washing and avoiding close contact with others limits spread of viral infections

30. Broad-Spectrum Antibiotics Penicillins Cephalosporins Carbapenems Tetracyclines Aminoglycosides Macrolides

31. Penicillins Special considerations Take on empty stomach Take with 8 oz water Do not take with soft drinks, fruit juice, or wine Administration with erythromycin or tetracycline may diminish effectiveness

32. Cephalosporins Special considerations Take on full or empty stomach May be crushed or mixed with food May cause false urine sugar test results Avoid alcohol consumption (continues)

33. Cephalosporins Warning! Cephalosporins may interact with alcohol, causing an Antabuse-like reaction • Flushing or syncope • Chest pain and palpitations • Arrhythmias and tachycardia • Hypotension

34. Carbapenems Contraindications Known hypersensitivity to same class of drugs Patients with demonstrated anaphylactic reactions to beta-lactams

35. Tetracyclines Contraindications Children under 8 years of age Pregnancy or lactation Renal or liver impairment (continues)

36. Tetracyclines Special Considerations Permanent discoloration of deciduous teeth Take on empty stomach with 8 oz water Do not take with dairy products, calcium, antacids, or iron

37. Aminoglycosides Contraindications Labyrinthine disease Myasthenia gravis Pregnancy or lactation Cautious use in renal impairment, elderly, infants, or children (continues)

38. Aminoglycosides Special considerations Can cause permanent damage to acoustic nerve Observe for ototoxicity or nephrotoxicity Drink plenty of liquids to reduce development of nephrotoxicity

39. Macrolides Ketolides Telithromycin Erythromycin Azithromycin Carithromycin (continues)

40. Macrolides Warning! Grapefruit juice decreases the speed at which the body breaks down certain medications. Drinking grapefruit juice can increase the effects and side effects of these drugs. Erythromycin can decrease the effectiveness of combination-type birth control pills.

41. Other Antibiotics Fluoroquinolones Monobactams Oxazolidinones Streptogramins Warning! Fluoroquinolones are associated with increased risk of tendonitis and tendon rupture. This risk is further increased for those older than 60; in kidney, heart, and lung transplant recipients; and with use of concomitant steroid therapy.

42. Antiseptics and Disinfectants Antiseptics Used on skin and body tissues Prevent or inhibit microorganism growth Bacteriostatic actions Disinfectants Used on objects and surfaces Kill vegetative forms of microorganisms Bactericidal action (continues)

43. Antiseptics and Disinfectants • Effectiveness depends on • Strength and temperature of solution • Time of exposure • Ionization rate of substance

44. Bleach • Recommended by OSHA more than any other disinfectant in medical and dental practices • Replace solution every 2 to 3 days • Inactivate HIV with 10% solution • Decontaminate surfaces with 1% solution