Integrity: Microorganisms Flashcards
How is the microbiomb involved in energy biosythesis?
Is is essential for the breakdown of resistant starch into SCFAs (short chain fatty acids)
What are short chain fatty acids used for?
SCFAs are the main energy source for enterocytes
They also have anti-tumor and anti-inflammatory properties
They stimulate satiety through production of protein YY
WHat are enterocytes?
Epithelial cells of the intestines
How does the microbiombe protect from pathogenic bacteria
It out competes any pathogenic bacteria
Some can also produce bacteriocins which directly kill salmonella, clostridium and listeria
How does the microbiombe interact with the nervous system?
Certain compounds formt he nervous system such a noradrenaline can actually affect the composition of the microbiombe
In turn the microbiombe can produce neurological compounds such a GABA
How is the microbiombe involves in bile acid production?
It can synthesis primary bile acids synthesised from cholesterol by the liver into secondary bile salts imporatants for many things including encouraging the release of insulin.
How does the microbiombe differ in obese people to lean people?
Lean: Higher proportion of Bacteroidetes
Obese: Higher proportion of Firmicutes
How does the microbiombe become altered in IBS?
Some bacteria are decreased:
Firmicutes, some Clostridium species
Some bacteria are increased:
Enterobacteriaceae, including E.Coli
Facultative anaerobes
What is helicobacter pylori?
Helicobacter pylori can be found attached to the gastric mucosa
It is a chronic infection which leads to inflammation, gastritis and even stomach cancer
Eradication is a good idea
How might the microbiombe be thought of as a treatment for Clostridioides Difficile infection?
C. Diff occurs after antibiotic treament as it is resistant to many antibiotics therefore blooms easily in a neutralised microbiomb.
It is shown that a faecal microbiota transplant can actually help treat C. Diff by reintroducing a healthy microbiomb.
4 common causes of community infection that are likely to come up in exams
Uropathogenic Escherichia coli
Neisseria meningitidis
Staphylococcus aureus
Streptocococus pneumoniae
Staphylococcus aureus can infect in two areas, what are these?
Superficial ( e.g. skin and soft tissue) infections
AND
Deep seated infections (bacteraemia, endocarditis, osteomyelitis)
If there is an ulcer what could it be?
Staphylococcus aureus
Is Staphylococcus aureus community or hospital aquired?
Both
Can be community but also
- Leading cause of Surgical site infections
- Other hospital acquired infections e.g. bacteraemias
- MRSA through acquisition of resistance genes
Is Staphylococcus aureus gram positive or gam negative?
Gram positive
Pink/Purple Positive/Negative?
Purple: positive
Pink: negative
Streptococcus pneumoniae
Is Streptococcus pneumoniae gram pos/neg
Gram positive
Where is Streptococcus pneumoniae a coloniser, and infection or invasive?
What is bacteraemia?
Bacteria in the blood
E. coli is gram ____
Negative
E. coli is ____ shaped
Rod
Where is E. coli a coloniser?
In our gut microbimob
What is a common cause of urinary tract infection?
Uropathogenic E. Coli
WHat is a glass test used for?
Neisseria meningitidis
You see if a rash fades under pressure, if it does not indicates meningitis
Neisseria meningitidis is gram ___
Negative
Neisseria meningitidis is ____ shaped
Cocci
Neisseria meningitidis causes what?
Meningitis and septicaemia
How does Neisseria meningitidis get to the C.S.F (Cerebrospinal fluid)
Common hospital aqquired pathogens
- Pneumonia- S. pneumoniae initially but also Gram negative bacteria
- Surgical site infections- S. aureus including MRSA but also other pathogens
- Urinary tract infections- E. coli but also other pathogens e.g. proteus etc.
- C. difficile infections- loss of microbiome in bowel.
What is an obligate pathogen?
One that is dependent on disease causation for transmission and evolutionary survival
What is this?
Lesions on the valve of the heart cause by a
staphylococcus aureus vegitation
A vegitation is where a bacteria invades and attaches to a thrombus
Why does staphylococcus aureus often cause vegetations?
One of it’s viralance factors is pro coagulation
Why sort of viralance factors does Streptococcus pneumoniae utilise?
They tend to promote caughing symtoms so that it can spread. They also promote mucous formation as this is a good envronment to live in
Why is E. coli a common cause of UTIs?
One of it’s virulence factors is flagellum which allow it to adher to and move up the urinary tract
If a skin condition blisters is the likely cause bacterial, fungal or viral?
Viral
e.g. herpes, genital warts, small pox, chicken pox
What does elevated c-reactive protein in the blood show?
It is a product of inflammation, particularly chronic inflammation
A 3-month-old baby presents with reduced feeding, mild fever, respiratory distress (evidenced by the
increased respiratory rate and subcostal and intercostal recession), and wheezing.
What is the most likely causal pathogen?
Respiratory syncytial virus (RSV)
Given the clinical presentation and
age, the most likely diagnosis is bronchiolitis.
Bronchiolitis is a common viral lower respiratory tract infection affecting infants and young children. It typically presents with symptoms of a cold (coryza) followed by increased work of breathing and wheezing.
The most common causative organism of bronchiolitis is Respiratory syncytial virus (RSV).
RSV is the most frequent cause of bronchiolitis in infants. While other viruses such as rhinovirus, adenovirus, and coronavirus can also cause bronchiolitis, RSV is the most prevalent, especially in the winter months
