Gram Negative Bacteria Flashcards
What are Escherichia Coli, Shigella and Salmonella examples of?
Enterobacteriaceae - rods of the intestines
Remember as related to poo
What, essentially are enterobacteriaceae?
Rods of the Intestines
What type of bacteria are Gram Negative Rods, typically colonise the gut, but can also cause GI infections if virulent?
Escherichia Coli
What are UTIs (simple and severe) and mild intestinal disease examples of?
Escherichia Coli - Gram Negative Rods
What bacteria causes dysentery, characterised by bloody, mucous filled diarrhoea spread by contamination of food by handlers (faecal- oral route) or at source?
Shigella dysenteriae - Gram Negative Rods
What is a gastrointestinal disease previously associated with eggs?
Salmonella Enteritidis - Gram Negative Rods
An example of Non typhoidal salmonella
What is a serious cause of infection called typhoid fever with systemic signs - which often results in carriers like Typhoid Mary maintaining it by passing it on through poor hygiene?
Salmonella Typhi and Paratyphi
There are two types of salmonella:
Non typhoidal salmonella and Typhoidal salmonella
Which category do Salmonella Enteritidis and
Salmonella Typhi/Paratyphi fit into?
Nontyphoidal = Enteritidis
Typhoidal = Typhi/Paratyphi
Enteric infections tend to be Gram Negative…..
Rods
What are neisseria meningitidis, neisseria gonorrhea, bordetella pertussis and haemophilus influenzae examples of?
Neisseria - Gram Negative Diplococci - Non enteric infections
NOT in the intestines
What bacteria is Gram Negative diplococci, capsulated and non-motile and also referred to as the meningococci?
Neiserria meningitidis
What bacteria is the leading cause of meningitis, which can be associated with septicaemia needing prompt antibiotic therapy?
Neisseria meningitidis
What bacteria is similar to n meningitidis but has no capsule and is motile?
(it is also called the gonococci)
Neisseria gonorrhoea - Gram Negative diplococci
What bacteria is the second most common STD in the UK, causing urethral, rectal and throat infections in men and women, and endocervical infections in women?
Neisseria gonnorhea
It also causes eye infections in new borns but is usually asymptomatic and can lead to pelvic inflammatory disease and ectopic pregnancy
What bacteria is the cause of whooping cough - a diseases that only uses humans as a reservoir and is globally increasing?
Bordetella pertussis
What bacteria is cocco bacilli - and causes invasive infections typically by type B influenza (80%)?
This also causes many infections, most often meningitis however there is a vaccination for this.
Haemophilius influenzae
What characterises type b h influenza?
a capsule round the cell
What type of gram-negative bacteria is mainly found in the GI Tract and can cause escherichia, salmonella, shigella, proteus, klebsiella, enterobacter, citrobacter and yersinia?
Enterobacteriacae
Self limiting GI infections (diarrhoea) and enteric fever (typhoid) are Gram-Negative Rods, but what are they?
Salmonella
The predominant cause of salmonella from food is campylobacter as we are now vaccinated against the one from where?
Eggs
Salmonella is not commensal. What does this mean?
We do not carry it inside us normally.
All strains will cause disease in humans
What disease caused by Gram-negative rods (enterobacteriacae) is resistant to freezing and drying, sensitive to most disinfectants and killed at high temperatures?
Salmonella
The reservoirs for what disease are GI Tracts of animals (including poultry, cattle, reptiles, arthropods and humans with enteric fever)?
What does this mean we need to do after touching animals?
Salmonella
WASH YOUR HANDS
What are 3 ways salmonella can be transmitted?
Food from infected animals
Contaminated food/water
Contact with an infected animal or person
What is the difference between you getting salmonella - or not getting it - even if you have ingested bacterial cells?
You have to ingest a certain amount - 10 to the power of 4-7
Is the onset of non-typhoidal salmonella or typhoidal salmonella faster?
Non-typhoidal = hours 12/72
It takes days for typhoidal salmonella to kick in - this is the one only found in humans
Which type of salmonella resulting from enterobacteriacae (Gram-Negative Rods) gives you gastroenteritis - often localised to the GI, diarrhoea and for less than 10 days?
Non-Typhoidal Salmonella
Which type of salmonella resulting from enterobacteriacae (Gram-Negative Rods) gives you enteric fever, resulting in systemic infection, diarrhoea/constipation and a symptom duration of about 3 weeks?
It can also be acute carriage or last for a year (chronic carriage)
Typhoidal Salmonella
5% of previously infected individuals become chronic carriers of what?
Enteric Fever (Typhoidal salmonella)
They keep spreading it around although they appear healthy
Diarrhoea in the returning traveller might be what?
Enteric Fever (Typhoidal Salmonella)
What are the 2 types of typhoid?
Salmonella paratyphi and salmonella typhi
What 3 ways can we prevent salmonella typhi?
Check stools of healthcare workers and food handlers for clearance (treat if not cleared)
Prevent faecal contamination of drinking water and food supplies
Good public health measures
What Gram-Negative Rod (enterobacteriacae) infection causes dysentry/shigellosis - can sometimes be called bacillary dysentry?
Shigella
What infection has the symptoms of abdominal cramps, tenesmus, frequent passage of mucoid bloody diarrhoea and is spread to person to person via faecal oral route?
Shigellosis - bacillary dysentry - don’t need many cells to get it
What may you see outbreaks of in primary schools - that results in mucoid bloody diarrhoea?
Shigellosis/Bacillary Dysentry
Bacteraemia, GI Infections, UTIs and neonatal meningitis are examples of Gram-Negative Rods (enterobactariacae), but what bacteria group are they in?
Escherichia Coli
E.coli is commensal of the human gut, but what is it associated with?
NIBU
Intestinal Infections
UTI Infections
Neonatal Meningitis
Bacteraemia
There are many types of Diarrhoeagenic E.Coli, but which is traveller’s diarrhoea?
ETEC, EHEC, EPEC, EIEC
EHEC
Remember this is enterobacteriaec
What type of E.coli is found in the GI Tracts of humans, cattle, pigs, amphibians and fish?
EHEC, Traveller’s diarrhoea
What 4 ways can EHEC/traveller’s diarrhoea be spread?
Undercooked Contaminated Meat
Unpasteurised Dairy Products
Contaminated Fruit and Veg
Environmental Outbreaks
Verotoxin producing E.coli (VTEC) and Shiga toxin E.coli (STEC) are otherwise known as what?
0157 most important
EHEC - traveller’s diarrhoea
Strain 0157 of EHEC is relatively rare but in what cases is it serious?
Infants
What enterobacteriacae (Gram-Negative Rods) results in mild gastroenteritis to severe bloody diarrhoea? This can lead to haemorrhagic colitis and haemolytic uremic syndrome
EHEC
What can E.coli cause (enterobacteriacae) that is more prevalent in women, where predisposing factors are pregnancy, sexual intercourse and catheterisation?
E.coli Urinary Tract infections
What are UTIs and EHEC often caused by?
E.coli - enterobacteriacae
For what do we need high bacterial cell numbers, symptoms and a raised white blood cell count in the urine to show it is there?
E.Coli UTI
UTIs can spread up to the kidneys and into the blood.
Why are they more common in women?
Shorter urethra and less effective cysto-ureteric valve, so E.coli can get in easier
What are cystitis and pyelonephritis examples of?
E.coli UTIs
What condition has symptoms of burning during urination, severe low back pain and fever, chills, nausea and vomiting
Just burning = cystitis
The rest = pyelonephritis - can usually see bacteraemia in blood, CVA tenderness and elevated RBC in urine and WBC can be seen
Pyelonephritis = PUS in urine
General UTIs are usually caused by E.coli, staphylococcus saprophyticus (usually kids) and sometimes Klebsiella, Enterobacter, Proteus and Citrobacter.
Which causes cystitis and pyelonephritis?
E.coli
What enterobacteriacae colonises catheters?
Proteus Mirabilis
What bacteria swarms on culture plates, can cause UTI, bacteraemia and pneumonia and is notorious for encrustation of catheters, due to a biofilm formation?
Proteus Mirabilis
If a patient has a catheter and proteus mirabilis is found in their urine culture, what does this usually signal?
Encrustation of catheter NOT infection
Staphylococcus Epidermis and Proteus Mirabilis - if you get a question asking which infects medical devices - what is the answer?
Staph Epidermis
as
Proteus Mirabilis is catheter only
What enterobacteriacae (gram negative rod) can cause severe pneumonia, UTI, surgical wounds and sepsis - that is commonly isolated from patients?
Klebsiella Pneumoniae
For which enterobacteriae is antibiotic resistance often an issue?
Klebsiella Pneumoniae
What enterobacteriacae has a cell membrane that mimics the host tissue so the immune system does not attack it?
Klesbsiella Pneumonia
also issue of antibiotic resistance for this reason
What is bacteraemia?
Bugs in the blood
Bacteraemia/bugs in the blood can often lead to what?
Sepsis = fever, raised heartrate, fast breathing, nausea, confusion
50% cases due to pneumonia
What 3 types of sepsis are there?
Uncomplicated - no need for hospital
Severe - interferes with vital organs
Septic Shock - organ failure
MOST GRAM NEGATIVE RODS
Where can klesiebella pneumonia be carried?
In the poo - this is why it is enterobacteriae
Name the 3 types of infection you have learned about that cover gram negative, non-enteric infections:
RBS
Respiratory Infections
Bacterial Meningitis
Sexually Transmitted Diseases
Which type of gram negative infections tend not to be in the intestines?
Non enteric infections
Bordatella - what does this mean?
That the infection is a short rod - so is basically either cocci or rod: not either
What does the gram-negative, non-enteric bordetella pertussis cause?
Is it a rod or cocci?
Whopping cough - and it is cocco-bacillus: nor rod or cocci
Bordatella = short rod, so looks like rod and cocci
What is the infection of the respiratory tract that is highly contagious and adapted to colonise humans called? It’s symptoms are lots of coughing fits.
What is it caused by?
Whooping cough - Bordatella pertussis gram = gram negative
What gram-negative cocco-bacilli infection is transmitted through droplet dissemination, usually arises from children with the disease and is spread amongst households due to the degree of contact being an important factor?
Whooping Cough - Bordatella Pertussis
Who do we give whooping cough immunisations to?
Infants under 2
Travellers going to endemic regions
Healthcare/at risk workers
Non-immunised people
What can we treat the gram-negative coccobacilli infection of whooping cough with?
macrolide antibiotics
can also prevent with 7 day course of clarithromycin (e.g. if someone in house has it)
Gram-negative cocci bacterial meningitis is inflammation of the lining of the brain.
What are the two types?
Neisseria Meningitidis
Haemophilus Influenzae
Bacterial Meningitis is caused by what type of bacteria?
Gram-Negative Cocci
What gram-negative cocci bacterial infection can present as a triad of fever, neck stiffness and altered mental status - but is most easily found by gram staining CSF?
Bacterial Meningitis
Which type of gram negative cocci-bacilli bacteria usually causes meningitis if capsuled (although other infections too), is typical in early childhood, can be carried by people without disease and is more common in winter and low socio-economic status people?
Haemophilius Influenzae
Which type of gram-negative bean shaped diplococci bacteria can be grouped based on capsule, can be carried in the nasopharynx, and is the leading cause of meningitis?
Neisseria meningitidis
bean shaped
What gram-negative cocci bacteria is motile with uretheral attachment components (not capsule)?
N.gonorrhoea
What infection may result in symptoms if the bacteria is in the urethra, rectal or endocervical regions but usually not in the pharyngeal region?
Gonnorhea - gram negative cocci
What infection can lead to PID, infertility, ectopic pregnancy and be passed to neonates giving them conjunctivitis?
It is also now becoming resistant to first line treatment
Gonnorhea
