Ch4 Flashcards
Corynebacterium diphtheriae characteristic is
Non-spore-forming, Gram-positive, pleomorphic rods Aerobic or facultatively anaerobic, catalase-positive, non-motile Ferments carbohydrates, producing lactic acid.
كيف ينتقل وينتشر ال Corynebacterium diphtheriae ؟
Respiratory droplets, skin contact
A subunit (catalytic domain) is
Inhibits elongation factor-2 (EF-2)
Blocks protein synthesis Cell death.
B subunit is
Binds heparin-binding epidermal growth factor (HB-EGF),
targeting heart & nerve cells.
ما هي أعراض ال Respiratory Diphtheria ؟
Sore throat, malaise, low-grade fever.
• Exudative pharyngitis → Forms thick, gray
pseudomembrane (tonsils, palate, nasopharynx).
• Adheres firmly, bleeds when removed.
• Bull-neck appearance (cervical
lymphadenopathy).
• Airway obstruction, hoarseness, stridor (severe
cases
Systemic Complications of Diphtheria symptoms is ?
Myocarditis Heart failure, arrhythmias, sudden death
Neuropathy Cranial nerve paralysis (soft palate, oculomotor, ciliary nerves).
• Peripheral neuropathy → Respiratory failure in severe cases
Cutaneous Diphtheria symptoms is
• Chronic non-healing ulcers.
• Gray membrane covering.
• Co-infection with Staphylococcus aureus or Streptococcus pyogenes
كيف تظهر ال Corynebacterium diphtheriae تحت المجهر ؟
Metachromatic granules
Treatment of Diphtheria to eliminate bacteria by ?
Antibiotics: Penicillin or erythromycin
Supportive care to Diphtheria is
Airway management, cardiac monitoring, bed rest
شو سبب ال Corynebacterium urealyticum ؟
Urinary tract infections
Urease hydrolyzes urea so Mack ?
release of NH4
+, increase in pH, alkaline urine, renal
stones
تكون ال Corynebacterium jeikeium
Opportunistic infections in immunocompromised (e.g., patients with
blood disorders, bone marrow transplants, intravenous catheters)
Disease association to C. jeikeium is
Bacteraemia, endocarditis; infection of foreign bodies and CSF shunts
Disease association to C. urealyticum is
Urinary tract infection, pyelonephritis, endocarditis
The Morphology to Listeria monocytogenes is ?
Short, non-branching gram-positive rods
▪ Motile at room temperature (end-over-end tumbling).
▪ Weak β-hemolysis on blood agar
كيف تنتقل ال Listeria monocytogenes ؟
Human-to-human transmission: Possible (e.g., transplacental, birth canal)
Symptoms of early neonatal infection with L. monocytogenes is ?
Disseminated infection (pneumonia
Meningitis, anaemia conjunctivitis)
Cardiopulmonary distress
Central nervous system signs
Vomiting and diarrhoea
Hepatosplenomegaly
Skin rash
Symptoms of Late neonatal infection with L. monocytogenes is ?
Meningitis
Irritability
Poor appetite
Fever
من خصائص ال L. monocytogenes ؟
Intracellular & extracellular Gram-positive coccobacilli
weak β-hemolysis on blood agar umbrella shape in semi-solid agar.
Treatment of L. monocytogenes is ? First-line
Ampicillin + Gentamicin
في حال كان الجسم حساس ل Ampicillin + Gentamicin يتم استبدال ب ؟
Trimethoprim-sulfamethoxazole, Linezolid, Daptomycin
ما هو ال Resistance ل L. monocytogenes ؟
Cephalosporins
Neuraminidase is ?
facilitates attachment and penetration into epithelial cells
