ENT BACTERIAL INFECTIONS DR K BABA MICROBIOLOGICAL PATHOLOGIST NHLS TSHWANE ACADEMIC DIVISION UNIVERSITY OF PRETORIA

Introduction Ear- external, middle and inner ear Middle ear- nares, nasopharynx, auditory tube and the mastoid air space Line with ciliated cells Normal flora of external ear are pneumococci, propionibacterium, Staphylococcus, and Enterobacteriaceae

Otitis external Acute –Localised or diffused Localised- staphylococcus aureus and streptococcus pyogenes Diffuse- swimmer’s ear Severe hemorrhagic external otitis media –Pseudomonas aeruginosa

Otitis external Chronic- irritation of drainage from middle ear Malignant – necrotizing infection Common in diabetes Pseudomonas aeruginosa Mycoplasma pneumoniae- painful infection of eardrum

Otitis media Acute Common in children Pnemococci, Haemophilus influenzae, Streptococcus pyogenes, Others are S. aureus, moraxella, Enterobacteriaceae, anaerobes, Chlamydia trachomatis, and mycoplasma pneumoniae

Otitis media Chronic Mainly anaerobes- Peptostreptococcus, Bacteroides, Prevotella, Fusobacterium Complication- mastoiditis Treatment with Amoxicillin/ Amoxi- clavulanate

Pathogenesis Local trauma Foreign bodies Excessive moisture Infection from middle ear All this can lead to otitis external

Pathogenesis Anatomic abnormalities of auditory tube Negative pressure in the middle ear from inflamed auditory tube following viral infection Pathogenic bacteria then enters from the nasopharynx

Laboratory diagnosis Needle aspirates Mastoid swabs Mastoid tissue Microscopy, culture and sensitivity

Sinusitis Sinuses are air filled cavities within the head Normally sterile Acute sinusitis- cold / influenza infection Purulent nasal and postnasal discharge Feeling of pressure over the sinus area Cough Sometimes fever

Sinusitis Chronic with bacterial colonization Surgery/drainage Treatment with Amoxicillin/ Amoxi- clavulanate Complications- extension to the orbit, skull, meninges, brain

Pathogenesis Bacterial complication of common cold Maxillary infection from dental source Inadequate drainage Mucociliary clearance and mucosal damage

Etiolgy Haemophilus influenzae Streptococcus pneumoniae Streptococcus pyogenes Moraxella Anaerobes

Laboratory diagnosis Puncture and aspiration Sinus drainage is unacceptable because of contamination Microscopy and culture

Case 2 A 6 month old baby presents with flu like symptoms. Greyish adherent membrane was found on the tonsil. What is the clinical diagnosis What sample would you send to the laboratory to confirm your diagnosis What are the characteristics of the causative organism How would you manage the patient

C. diphtheriae Transmission –droplet infection; hand to mouth Laboratory Diagnosis –Nasopharyngeal secretions or swabs –Throat /nasal swabs –Loffler’s; Hoyle’s; Tellurite containing blood agar –Black and shiny colony –Elek’s for toxin production –Nucleic acid amplification with sequencing

Pathogenesis Diphtheria toxin Bacteriophage carrying the tox gene Classic A-B toxin A active subunit and B binding subunit Block protein synthesis Inactivate elongation factor 2 (EF-2) required for polypeptide elongation

Diseases Respiratory: tonsilitis, pharyngitis (fever, sore throat, grey pseudomembrane on the tonsils) Cutaneous: ulcerating skin lesion with grey membrane Complications: Severe and potentially fatal; nerve weakness/paralysis; myocarditis/cardiac failure; airway obstruction

Management Antitoxin Penicillin/Erythromycin Vaccine is usually administered together with pertusis and tetanus toxoids as DPT

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