Laboratory

Laboratory
B57: BAL, sputum, associated specimens

Type of specimen Target organism CAP HAP Lung abscess Cystic fibrosis Mycobacteria disease Parasites Fungal infection Consider bioterrorism for these organisms if there is no travel history Media Safety Processing specimen Review the sputum: Is it salivary, mucosalivary, mucoid, mucopurulent, purulent and/or bloodstained? Put in on the report. If salivary, reject (unless the patient is […]

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Laboratory
UK SMI notes – Ear Infections.

Type of specimen: Ear swab Middle ear fluid Scraping of material from the ear canal (for fungal infection) Expected organisms Otitis Externa Acute localised otitis externa Staphylococcus aureus Group A Streptococcus furuncle Erysipelas Acute diffuse otitis externa Pseudomonas aeruginosa S. aureus Anaerobes Treatment – topical cleaning of debris. Antibiotics are not useful. Chronic otitis externa Colonisation by Enterobacteriaceae Fungi Treatment […]

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Laboratory
SMI: Investigation of whooping cough

Types of specimen Cough plates are not recommended. Selective media It contains blood or charcoal or both, along with selective antibiotic supplements – penicillin, cefalexin or meticillin.It should be able to suppress other nasopharyngeal flora. Meticillin is the least inhibitory, and cefalexin is the most. Cefalexin is the drug of choice for selective media in […]

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Laboratory
SMI: Investigation of Throat-Related Specimens

Specimens Throat swab, posterior pharyngeal swab, nasopharyngeal swab, pharyngeal washings, pus aspirate, oropharyngeal swab, throat gargle. Why To investigate upper respiratory tract infection – Pharyngitis, Tonsillitis, Epiglottitis, and Laryngitis. Condition Target organisms Pharyngitis(sore throat) 1. Viral (commonest),2. Group A Streptococcus/ Streptococcus pyogenes,3. Group C/G Streptococcus – Streptococcus dysgalactiae subspecies equisimilis,4. Streptococcus anginosus group,5. Corynebacterium – […]

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Laboratory
SMI Summary: Investigation of bone marrow

Because it is an invasive procedure, bone marrow biopsy (typically collected from the posterior iliac crest or the sternum) is rarely used. It’s also proposed that it shouldn’t be done on people who are immune-competent.It may be useful in the diagnosis of infection in immunocompromised patients (HIV, transplant patients, or patients on high-dose steroids), caused […]

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Laboratory
SMI notes: Investigation of infectious causes of dyspepsia (SMI B 55)

There are  2 SMIs related to H pylori- Identification of Helicobacter spp. (SMI ID26) & Investigation of infectious causes of dyspepsia (SMI B55). Available tests for the diagnosis of H. pylori infection There are 4 major types of tests that we can use to test for H pylori. 1. Urea breath test (UBT) 2. Stool antigen test […]

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Laboratory
SMI (note): Investigation of swabs from the skin and superficial soft tissue infection

Specimen Advice for the users: Safety Processing Gram stain – usually not done unless deep-seated pus from a normally sterile site Plate selection CONDITION PLATES All clinical conditions Blood agarCLED/MacConkey agar Wound swab Selective anaerobic agar with metronidazole disc Pus Fastidious anaerobic, cooked meat broth;then Subculture to blood agar. Cellulitis in childrenHuman bite Chocolate agar […]

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Infection
Screening blood donors for infection (note)

Please note this is a study note, keeping the exam in mind. This is not a guideline and should not be used for that purpose. It is not for clinical use either. You should contact your doctor for clinical advice. Blood donation screening ORGANISM MANDATORY TEST ADDITIONAL TEST HIV anti-HIV 1+2 or HIV 1+2 Ag/Ab […]

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Infection
Neurobrucellosis

Brucellosis is a zoonotic infection transmitted to humans from animals (cattle, goats, sheep) via The UK is a non-endemic country. Most brucella cases in the UK are imported cases with links to Mediterranean or Middle Eastern countries. However, Brucella is also endemic in Central Asia, China, South Asia, sub-Saharan Africa, and some parts of Middle and […]

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Laboratory
Culture media and composition

This is a list of some culture media and their composition. MEDIA SUPPLEMENTS TARGET ORGANISMS ABC plates Alpha-galactosidase Salmonella sp. Alkaline peptone water [pH – 8.6 ± 0.2] NaCl, peptone Enrichment of Vibrio spp. Aztreonam Blood Agar Aztreonam, blood agar base Gram-positive, especially fastidious gram-positive organisms BHI Broths Calf brain and beef heart infusion solids, peptone […]

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