Pathogenic bacteria possess characteristics that enable them to circumvent the body's defenses and exploit its resources, resulting in infection
Bacterial infections spread by a variety of mechanisms: direct contact, ingestion, inhalation
Staphylococcus aureus
Gram-positive cocci usually arranged in pairs, short chains, or in grape-like clusters, found in the skin and the nasopharynx, produces enzymes and toxins that contribute to its virulence and pathogenicity
Staphylococcus aureus
- Produces enzymes and toxins
Responsible for its invasiveness and pathogenicity
Sudden onset of perioral erythema that covers the whole body within two days
Nikolsky sign - displacement of the skin when slight pressure is applied over the skin
Exfoliative toxin is responsible for the manifestation
7-10 days - antibodies against exfoliative toxin are produced and enabling the skin to become intact again, only the outer layer of the epidermis is affected hence there will be no scarring
Treatment and Prevention for Staphylococcus aureus
Oxacillin - the only penicillin-derived antibiotics that has remained active against S. aureus
Incision and drainage
Patient Care for Staphylococcus aureus infections
Standard Precautions for skin, burn, and wound infections if they are minor
2. Contact Precaution if major, SSSS (Staphylococcus scalded skin syndrome)
3. Standard Precautions for infections caused by methicillin-resistant S. aureus (MRSA)
4. Contact Precautions if wounds cannot be contained by dressings
Staphylococcus epidermidis
Gram-positive bacteria and it is a part of the skin's normal flora, frequently linked to "stitch abscess", UTI, and endocarditis, it causes infections in people who utilize prosthetic equipment
Streptococcus pyogenes
Gram-positive cocci, belong to group A beta-hemolytic (cause complete hemolysis of blood), M protein is the major virulence factor (anti-phagocytic), produces enzymes and toxins responsible for pathogenesis of infection
Clinical Manifestations of Streptococcus pyogenes
Erysipelas (St. Anthony's Fire)
Cellulitis
Necrotizing Fasciitis
Complications of Streptococcus pyogenes
Acute glomerulonephritis
Rheumatic fever
Laboratory Diagnosis for Streptococcus pyogenes
Microscopy - gram stain of infected tissue will show gram-positive cocci
Culture - positive beta hemolysis in blood agar
Bacitracin test - antibiotic susceptibility test
Diseases of the Upper Respiratory Tract
Common Cold
Tonsillopharyngitis
Croup
Influenza
Diphtheria
Diseases of the Lower Respiratory Tract
Chronic Bronchitis
Pneumonia
Pertussis
Tuberculosis
Tonsillopharyngitis
Inflammation of the pharynx and tonsils
Tonsillopharyngitis
Seasonal occurrence
Children: 5-10 years
Adults: 18-20 years
Causative agent of Tonsillopharyngitis
Streptococcus pyogenes
Mode of transmission for Tonsillopharyngitis
Direct contact with large droplets or respiratory secretions
Clinical manifestations of Tonsillopharyngitis
Sudden onset of fever
Sore throat
Headache
Nausea
Malaise
Pain
Tonsillopharyngeal erythema
Laboratory diagnosis of Tonsillopharyngitis
Culture of specimen obtained by swab of the posterior pharyngeal-tonsillar regions
Treatment and prevention of Tonsillopharyngitis
Penicillin
Erythromycin
Clindamycin
Diphtheria
Serious infection caused by a bacteria that make toxin (poison)
Diphtheria
Can lead to difficulty breathing, heart failure, paralysis, and even death
Causative agent of Diphtheria
Corynebacterium diphtheria
Incubation period of Diphtheria
2 - 5 days
Period of communicability for Diphtheria
Up to 3 weeks following onset of manifestations
Clinical findings of Diphtheria
Inflammation of respiratory tract
Sore throat
Fever
Thick, gray, adherent pseudomembrane over the tonsils & throat
Extension of the membrane into the larynx and trachea causing airway obstruction
Clinical findings of Diphtheria (continued)
Obstruction may cause suffocation relieved by intubation or tracheostomy
Do not attempt to remove the membrane because it is tightly adherent to the underlying tissue à massive bleeding
Arrhythmia
Nerve weakness or paralysis
"Bull neck" appearance = massive enlargement of cervical lymph nodes
Laboratory diagnosis of Diphtheria
Swab from the nose, throat or other suspected lesions
Gram stain
Culture = definitive diagnosis
Treatment for Diphtheria
Penicillin G
Erythromycin
Diphtheria antitoxin = to neutralize the exotoxin
Prevention of Diphtheria
Vaccine
Diphtheria-Pertussis-Tetanus (DPT)
Given: 2 - 4 - 6 months
Isolate infected patients
Chronic Bronchitis
A chronic inflammatory condition involving the bronchi