MPharm Programme Micro 1 and 2: Bacterial and viral Respiratory Infections

Flashcards covering bacterial and viral respiratory infections, lung physiology, immunity, respiratory tract infections, specific diseases like pneumonia, tuberculosis, influenza, RSV, and the common cold, as well as emerging respiratory pathogens.

What is URT?

The upper respiratory tract, which has abundant and diverse microbiota.

What is LRT?

The lower respiratory tract, which is normally sterile.

Name some common microbes in the normal lung

Dolosigranulum, Staphylococcus, Streptococcus, Corynebacterium, Prevotella, Moraxella, Haemophilus, Alloiococcus, Lachnospiraceae, Sphingobacteria, Veillonella, Bifidobacterium, Rothia, and Cutibacterium.

What are the components of Lung Immunity?

Mechanical barriers, chemical factors (mucus, complement, cytokines), and immune cells like alveolar macrophages.

What are the components of the Mucociliary Elevator?

Epithelial (ciliated) cells, secretory cells, periciliary liquid (PCL), and mucus layer.

Which cells produce mucus in the airways?

Goblet cells in the trachea, changing to club and serous cells further down, producing mucus with mucins as the main component.

Distinguish between upper and lower respiratory tract infections.

Upper respiratory tract infections are often acute, mainly viral but can be bacterial, while lower respiratory tract infections tend to be more serious.

What are Koch's Postulates?

1. Microorganism must be found in abundance in diseased organisms. 2. Microorganism must be isolated and grown in pure culture. 3. Cultured microorganism should cause disease in a healthy organism. 4. Microorganism must be reisolated from the inoculated host.

Name some common respiratory diseases.

Pharyngitis, laryngitis, sinusitis, and the common cold for the upper respiratory tract; bronchitis, bronchiolitis, and pneumonia for the lower respiratory tract.

How are respiratory tract infections generally transmitted?

Droplets from coughing and sneezing, direct person-to-person contact, and contaminated surfaces.

List some measures for preventing respiratory infections.

Handwashing, soap/alcohol rubs, cough etiquette, patient isolation, PPE, and surface decontamination.

Name some common species associated with COPD exacerbations.

H. influenzae, S. pneumoniae, M. catarrhalis; P. aeruginosa in more advanced disease.

What microorganisms cause community and hospital-acquired pneumonia?

S. pneumoniae, Group A Streptococcus, H. influenzae, M. catarrhalis, Legionella, Mycoplasma, Chlamydia for community-acquired pneumonia; G- bacilli and G+ cocci (MRSA) for hospital and ventilator-acquired pneumonia.

How does Group A Streptococcus evade the immune system?

Attachment/invasion is mediated by M proteins, Pili F proteins, and hyaluronic acid capsule; immune evasion is through the hyaluronic acid capsule, M-protein, secreted enzymes (Streptolysin O and S, Proteinase SpeCYP, Streptokinase, C5a peptidase).

What are the key characteristics of Tuberculosis?

Mycobacterium tuberculosis is the main cause; can only be transmitted during active infections; mainly affects the lungs but can spread to other systems.

Describe the Tuberculosis disease cycle.

Bacterium breathed in, ingested by macrophages, triggers a response, new cells surround macrophages, environmental factors trigger killing of macrophages, granuloma disintegrates, spreads in lung.

What are some common diagnostics for TB?

Heaf tests (replaced by Mantoux), Mantoux tests, Sputum microscopy and culturing, Radiography, and Interferon gamma release assay.

What is the treatment for TB?

Isoniazid and rifampicin for 6 months; pyrazinamide and ethambutol for the first 2 months.

How is Tuberculosis prevented?

Give Bacillus Calmette-Guérin vaccine (BCG vaccine), a live attenuated vaccine derived from M. bovis.

Distinguish between the different types of Influenza.

A and B generally associated with human infections, with A responsible for pandemics and B less common; C primarily infects pigs and dogs, and D only infects pigs and cattle.

What are the key structural components of Influenza?

Hemagglutinin (binds virus), Neuraminidase (cleaves sialic acid), M1 matrix protein (mediates encapsidation), and M2 Ion channel (maintains pH).

Distinguish between Antigenic Shift and Antigenic Drift.

Antigenic Shift (only in Influenza A, causes major changes) and Antigenic Drift (in Influenza A and B, gradual accumulation of point mutations).

What are the components of Naming Flu strains?

Virus type, Geographic origin, Strain number, Year of isolation, Virus subtype (e.g., A/Fujian/411/2002 (H3N2)).

Name some famous Flu strains.

Spanish Flu (H1N1), Asian Flu (H2N2), Hong Kong flu (H3N2), Bird Flu (H5N1), and Swine Flu (H1N1).

What determines how serious an Influenza infection will be?

Hemagglutinin can only be cleaved by proteases in throat and lungs (mild) or by a variety of proteases throughout the body (highly virulent).

What are the symptoms of a cold?

Gradual onset, rare fever, slight aches, uncommon chills, sometimes fatigue, common sneezing, mild to moderate cough, common stuffy nose, common sore throat, and rare headache.

What are the symptoms of the flu?

Abrupt onset, usual fever, severe aches, fairly common chills, usual fatigue, sometimes sneezing, can be severe cough, sometimes stuffy nose, sometimes sore throat and common headache.

How is flu treated?

Bedrest, fluids; antivirals (Zanamivir & Osletamivir, neuraminidase inhibitors), vaccination to at-risk groups.

What are some antivirals used to treat Influenza?

Zanamivir & Osletamivir (neuraminidase inhibitors), Amantadine hydrochloride (blocks M2 ion channel), and Baloxavir marboxil (inhibits influenza polymerase - not approved in the UK).

What are the different types of Flu vaccines in the UK?

Live attenuated quadrivalent vaccine (nasal spray) for eligible children 2-17; quadrivalent injected vaccine (egg or cell grown) for adults 18-64; adjuvanted trivalent injected vaccine (grown in eggs) or quadrivalent injected vaccine (cell grown) for adults 65+.

What is Respiratory syncytial virus (RSV)?

Common respiratory virus that causes mild, cold-like symptoms but can progress to bronchiolitis or pneumonia.

How is the Common Cold treated?

Supportive care for symptom management.

What are the main characteristics of Coronaviruses?

Most viruses in this family infect different species of animals; SARS CoV and MERS CoV can cause severe respiratory infections.

What are the main vaccines developed and approved in the UK for COVID-19?

Moderna, Pfizer/BioNTech, Oxford/AZ.