Classification of Pathogenic Bacteria 1 Flashcards
<p>What are things that can infect patients?</p>
<p>Bacteria</p>
<p>Parasites</p>
<p>Viruses</p>
<p>Fungi</p>
<p>What is bacteria?</p>
<p>A major group of microorganisms causing infectious disease</p>
<p>What is the process of gram staining?</p>
<p>1) Application of crystal violet (purple dye)</p>
<p>2) Application of iodine (morant)</p>
<p>3) Alcohol wash (decolourisation)</p>
<p>4) Application of safranin (counter stain)</p>
<p>What colour does gram positive bacteria appear?</p>
<p>Purple</p>
<p>What colour does gram negative bacteria appear?</p>
<p>Pink</p>
<p>What does gram staining do?</p>
<p>Provide early indication of the genus of bacteria</p>
<p>What are advantages of gram staining?</p>
<p>Quick, simple and inexpensive way to classify bacteria</p>
<p>What does knowing the classification of bacteria allow?</p>
<p>Targeted treatment as different classes of antibiotics are effective against gram positive and gram negative bacteria</p>
<p>What are the main classes of gram positive bacteria?</p>
<p>Aerobic<br></br> Cocci<br></br> Chains - streptococci and enterococci<br></br> Alpha, beta or non haemolytic<br></br> Clusters - staphylococci<br></br> Coagulase negative or positive<br></br> Bacalli - small and large</p>
<p>Anaerobic<br></br> Cocci<br></br> Bacalli</p>
<p>What is cocci bacteria?</p>
<p>Bacteria with a spherical shape</p>
<p>What is bacalli bacteria?</p>
<p>Bacteria with a rod shape</p>
<p>What are the two classes of staphylococci (aerobic cocci clusters)?</p>
<p>Coagulase positive</p>
<p>Coagulase negative</p>
<p>What is coagulase?</p>
<p>An enzyme that convers fibrinogen into fibrin which causes blood clotting</p>
<p>What is used to determine whether bacteria is coagulase positive or negative?</p>
<p>Coagulase test</p>
<p>What is an example of coagulase positive staphylococci and what can it cause?</p>
<p>Staphylococci aureus which can cause:</p>
<p>MRSA</p>
<p>MSSA</p>
<p>What is staphylococcus commonly resistant to and why?</p>
<p>Penicillin due to production of penicillinase</p>
<p>What is MRSA?</p>
<p>Methicillin resistant staph aureus</p>
<p>Where is staphylococci a commensal?</p>
<p>In the nose, axilla and perineum</p>
<p>What are examples of coagulase negative staphylococci?</p>
<p>Staphylococci epidermis</p>
<p>Staphylococci haemolyticus</p>
<p>Staphylococci saprophyticus</p>
<p>Staphylococci lugdenensis</p>
<p>What are coagulase negative staphylococci commonly?</p>
<p>Skin commensals</p>
<p>When can coagulase negative staphylococci cause problems?</p>
<p>In the presence of foreign objects such as prosthetic heart valves</p>
<p>What classes of bacteria are there in terms of how they degrade blood?</p>
<p>Alpha haemolytic (partial haemolysis)</p>
<p>Beta haemolytic (complete haemolysis)</p>
<p>Non-haemolytic</p>
<p>What is haemolysis?</p>
<p>Rupture or destruction of red blood cells</p>
<p>What are examples of alpha haemolytic streptococci and what do they cause?</p>
<p>Streptococci pneumoniae which causes:<br></br>Pneumonia<br></br>Meningitis<br></br>Septicaemia</p>
<p>Viridans streptococci which causes:<br></br>Infective endocarditis (infection of heart valves)</p>
<p>What does streptococci pneumoniae cause?</p>
<p>Pneumonia</p>
<p>Mengingitis</p>
<p>Septicaemia</p>
<p>What is infective endocarditis?</p>
<p>Infection of heart valves</p>
<p>How can beta haemolytic streptococci further be identified?</p>
<p>By carbohydrate surface antigens ranging from A to G</p>
<p>What are the clinical important groups of beta haemolytic bacteria?</p>
<p>Groups A, B, D and F</p>
<p>What is an examples of group A beta haemolytic streptococci and what does it cause?</p>
<p>Streptococcus pyogenes which causes:</p>
<p>Pharyngitis</p>
<p>Cellulitis</p>
<p>Necrotising fasciltis</p>
<p>What is an example of a group B beta haemolytic streptococci and what does it cause?</p>
<p>Streptococci agalactiae which causes:</p>
<p>Neonatal sepsis (meningitis/bacteraemia)</p>
<p>Invasive infections</p>
<p>What is an example of a group D beta haemolytic streptococci and what does it cause?</p>
<p>Streptococci enterococcus faecalis which causes:</p>
<p>Urinary tract infection</p>
<p>Infective endocarditis</p>
<p>What are some examples of aerobic gram positve bacteria?</p>
<p>Clostridium genus:</p>
<p>Clostridium difficile</p>
<p>Clostridium perfringens</p>
<p>Clostridium tetani</p>
<p>Where is clostridium difficile cause found and what does it cause?</p>
<p>In the gut and it causes diarrhoea</p>
<p>What isclostridium difficile spread by?</p>
<p>Pores</p>
<p>Where is clostridium perfringens found and what can it cause?</p>
<p>Found in soil and a normal commensal in gut faeces, if it infects wounds it can cause gas gangrene</p>
<p>What does clostridium cause?</p>
<p>Toxin produced causes tetanus</p>
<p>What are examples of biological spore warfare?</p>
<p>Clostridium botulnum (source of botox)</p>
<p>Basillus anthracis (cause of anthrax)</p>
<p>What is colonisation?</p>
<p>Germs being in the body buyt not making you sick</p>
<p>What is infection?</p>
<p>Germs are in the body and making you sick</p>
