Infections Flashcards
Meningococcal sepsis
Virulence factors: Lipopolysaccharide
Commensal of the nasopharynx
Neisseria meningitidis
UTIs, Peritonitis, neonatal meningitidis
Commensal at the colon (fecal - perineal route)
Escherichia coli
Commensal of the skin
MRSA
Skin abscess
Staphylococcus aureus
Commensal of the skin
Forms slime - very difficult to remove
Staphylococcus epidermidis
Group A, B - haemolytic
Common cause of bacterial pharyngitis/tonsillitis
Virulence factors
- Hyaluronic acid capsule
- M protein
- Streptokinase (breaks down blood clots)
Streptococcus pyogenes
Commensal at the colon Associated with antibiotic usage Sporulating - very difficult to remove Virulence factors: - Toxin A (enterotoxin) - diarrhoea - Toxin B (cytotoxin)
Clostridium difficile
Community acquired pneumonia
Polysaccharide capsule
Encapsulated
Streptococcus pneumoniae
Oral commensal
Alpha haemolytic usually
Tooth decay
Bacterial endocarditis
Viridans streptococci
Associated with children and pneumonia
Nasopharyngeal commensal in certain disease free individuals
Haemophilus influenzae
Causes typhoid or enteric fever
Travel related infection (fecal-oral route)
Drinking contaminated water
Salmonella typhi
Causes legionnaire’s disease or legionellosis
Air droplet mode of transmission
Causes acute lobar pneumonia
Legionella pneumophila
Double stranded DNA, enveloped virus Infects B cells Splenomegaly Cold like symptoms Gastric lymphoma Burkit’s lymphoma
Epstein-Barr virus
First presentation as chickenpox
Enveloped double stranded DNA virus
Reappears as shingles on a single dermatome
Immunocompromised
Varicella zoster
Double stranded DNA Enveloped Fatigue; loss of appetite; abdominal pain; nausea Jaundice Blood-borne virus 6 weeks - 6 months After 6 months chronic infection ALT; ALP; bilirubin all raised
Hepatitis B
Blood borne viruses
80% chronically infected
Mostly asymptomatic
- fatigue, anorexia, nausea, abdominal pain
Hepatitis C
Single stranded RNA, enveloped, retrovirus
Opportunistic illnesses:
- oral candidiasis
- kaposis sarcoma
- pneumocystis pneumonia
HIV
Double stranded DNA, non-enveloped
Replicates in endothelial cells
Conjunctivitis, sore throat, fever, cough
Adenovirus
Winter vomiting bug
Single stranded RNA, non-enveloped
Fecal - oral route, low viral load required to cause infection
Norovirus
Parasite
Hepatomegaly and splenomegaly
(RBC destruction -> increased bilirubin and thus Jaundice)
Plasmodium falciparum
Fungi - mould
Opportunistic infection
Commensal of vagina, mouth
Candida albicans
Fungi
Acute infection of the lungs
Opportunistic
Aspergillous
Severe inflammation of dermal and subcutaneous layers of skin
Bacteria enter break/crack in skin
Cellulitis
Peritonsillar abscess
Rheumatic fever
Necrotising fasciitis
Erysipelas
Tonsillitis
Streptococcus pyogenes
Pneumonia, intra abdominal
Urinary sepsis
Skin and soft tissue infections
Affects CVS, resp, CNS, liver, GI tract
Normal immune response becomes exaggerated so patient is damaged by own immune system
Sepsis - Neisseria meningitidis
- gram -ve diplococci
Female
Dysuria - pain when passing urine
Polyuria
Commensal of the colon displaced
Nitrates found in urine
Fecal contamination or direct contact
UTI - E.Coli
Gram -ve rods
Commensal in vaginal flora Yeast overgrowth Vaginal thrush Itching and burning pain White discharge
UTI 2
Candida Albicans
Varicella zoster reactivation
Usually latent in ganglia of cutaneous nerves
1 in 5 childhood reactivation
Shingles
Gram -ve coccbacilli Nasopharyngeal commensal in some Opportunistic infection Mostly associated with children Cough up sputum
Pneumonia - Haemophilus influenzae
Gram +ve bacilli Anaerobes Minor component of normal flora at colon Associated with antibiotic usage Sporulating - resistant to heat/acid/antibiotics Identified through stools
Profuse Diarrhoea - Clostridium difficille
Gram +ve cocci in chains Commensalism of the mouth Upper right sterna border at the 2nd right intercostal space Systolic murmur Poor state of teeth Vegetation growth
Aortic valve stenosis/Endocarditis - Viridans streptococci
Bronchitis
Streptococcus pneumoniae
Haemophilus influenzae
Moraxella catarrhalis
