Microbiology 2 - TB, Respiratory Infections, STIs, GI Infections, HAI, Wound, bone and joint fection, Urinary infection, CNS infection, Antimicrobials, Endocarditis Flashcards
What does PET stand for?
Positron electron tomography
What is used in PET?
Radio transparent - glucose
What % of TB pts get drug induced liver injury?
5-10%
1% life threatening - hepatic necrosis, may require liver transplant.
Patient being treated for TB comes in with severe vomiting, diagnosis?
Drug induced liver injury
How long are TB patients infectious?
Infectious until they have done 2 full weeks of Tb treatment. Can do sputum sample to check.
What should you exclude if or presents with liver abscess?
Immunodeficiency - HIV
Bowel Cancer - cancer breaks the basement membrane, makes a hole bacteria can escape from in blood —> goes to liver —> abscess
80 year old known COPD patient presents with SOB, wheeze, cough and fever. give features of organism too i.e. gram stain and shape.
Haemophilus Influenzae - most common respiratory organism in smokers
Gram negative coccobacilli
70 year old lady presents with SOB and cough productive of rusty brown sputum give features of organism too i.e. gram stain and shape.
Streptococcus pneumoniae - rusty brown sputum
Gram positive cocci (in groups of two/diplococci)
45 year old man presents to ED stating he feels very unwell with a dry cough, fever, rhinorrhea and muscle aches. Observations are within normal limits. Bloods show CRP 12, WCC 9. No past medical history. give features of organism too i.e. gram stain and shape.
Influenza virus - the flu
Virus - no shape
65 year old alcoholic presents with SOB, productive cough, haemoptysis and feeling hot and cold. give features of organism too i.e. gram stain and shape.
Klebsiella - haemoptysis (cavitating lesion)
Gram negative bacilli
Most likely respiratory organism in a smoker?
Haemophilus influenzae
Pneumonia after an illness
Usually staph aureus
Alcoholic person with bloody sputum
Klebsiella
What is an important thing to consider in COPD pneumonia?
They get atypical pneumonia
45 year old man presents to ED stating he feels “very unwell”, with a dry cough, fever, rhinorrhea and muscle aches. Observations are within normal limits. Bloods show CRP 12, WCC 9. No past medical history.
treat
Encourage oral intake and give discharge advice
influenza virus
65 year old alcoholic presents to ED with SOB, productive cough, haemoptysis and feeling hot and cold. Temp 38.5, HR 110. Inflammatory markers are raised.
IV Co-amoxiclav + clarithromycin
signs of systemic illness
Pathagnomonic for Bacterial Meningitis
Polymorphs on LP
What acronym for managing infection in COPD patients?
ABC
Antibiotics
Bronchodilators
Corticosteroids
How to manage mild and moderate - severe IECOPD?
Mild = doxycycline + inhalers + prednisolone + supportive
Mod-severe (sepsis/respiratory compromise) = IV abx + nebulisers + hydrocortisone STAT + supportive
50 year old has ben recovering well on the ward after elective bowel resection when he develops a cough. CXR shows pneumonia. Routine MRSA swabs are negative. treat
IV Tazocin (piperacillin + tazobactam)
HAI - hospital acquired pneumonia: first line in IV Tazocin
70 year old lady presents to GP with cough productive of rusty brown sputum for one week. Observations are within normal limits.
treat
PO Amoxicillin
strep pneumoniae
How do manage CAP?
Community acquired pneumonia:
classic: mild-moderate: penicillin, moderate-severe: penicillin + macrolide (co-amoxiclav + clarithromycin)
atypical: chlaemydia, mycoplasma: use protein synthesis abx: macrolide/tetracycline
hotel
legionella pneumoniae
nigerian man - which organism
Pneumocystis jirovecii
after HIV
A businesswoman has recently returned from a hotel conference with a cough and fever. Bloods show Cr 65, K+ 4.0, Na+ 129 which organism
Legionella pneumoniae
A 35 year old Nigerian man presents with a dry cough. On examination, she is cachectic and has multiple purple skin lesions on his face and torso.
Pneumocystis jirovecii
A 45 year-old keen birdkeeper presents feeling unwell for 2 weeks with fever, muscle aches, cough and SOB.
which organism?
Chlamydia psitacci
pneumonia and Bone Marrow Treatment which organism:
Aspergillius + CMV
pneumonia and Splenectomy - which organism
Encapsulated organisms - H. influenza, S. pneumonia, N. meningitidis
Poor response to abx - which pneumonia organism
TB
Joint pain and erythema multiforme (target lesion rash)
Mycoplasma pneumonia
HIV pneumonia organisms
Pneumocystis jirovecii
Cryptococcus neoformans
What are the time frames different types of meningitis develop over and which type is associated with each?
Hours - Bacterial
Days (3-7) - Viral
Weeks to Months - TB
Weeks to Months - Fungal
20 year old woman presents with sudden, severe, persistent headache, fever and neck stiffness. On examination, GCS 15/15, she is very irritable and is sitting in the dark. CT head normal. Lumbar puncture shows cloudy CSF with WCC 100, protein level is high, glucose is 1.5mmol/L. Serum glucose is 6 mmol/L.
diagnose
Bacterial meningitis
bacterial as v. sudden onset high WCC
A 40 year old man who was treated for TB in Bangladesh several years ago presents with an acute onset right flank pain radiating to the right groin. PMH: chronic back pain. On examination the abdomen is soft, he is unable to flex his right hip. Observations: T 38.6, HR 105, BP 130/80, RR 20, O2 98%. Urine dip is normal.
Spinal TB
previous TB - latent TB has activated
could be primary psoas abscess
Treatment for TB
RIPE Rifampicin Isoniazid Pyraminazine Ethambutol
all for 2 months, first 2 for 4 more.
extrapulmonary TB is given for 12 months
latent TB usually treated with only Isoniazid 6-9 months
A 50 year old man presents with a rash on the soles of his feet and palms of his hands. His only previous history is a painless ulcer on his penis that healed itself. VDRL test is positive.
diagnose and organism
Syphilis
Treponema pallidum
A 30 year old man presents with a painful ulcer on his penis. Swabs grown on chocolate agar demonstrate the responsible microbe.
diagnose and organism
Chancroid
Haemophilus ducreyi
A 21 year old man presents for a routine sexual health check with no symptoms. Urinary NAAT test reveals a positive result.
diagnose and organism
Chlamydia
most common STI in UK, also most common with no symptoms
Chlamydia trachomatis
A 40 year old man presents with a 4 day history of swollen right testis. On examination there is swelling and a tender mass palpable separate to the testis. He has also noted some blood in his semen. Temperature is 38.4
diagnose and organism
Epididymitis
Neisseria gonorrhoae
VDRL Test Positive
Syphillis
Chocolate Agar
Chancroid
most common STI uk
chlamydia
2 common presentations for gonorrhoea
asymptomatic, urethral discharge
2 common presentations for chlamydia
asymptomatic, urethral discharge
A 30 year old vegan presents with offensive smelling vaginal discharge. Microscopy reveals clue cells. Whiff test is positive.
diagnose and managment
Bacterial vaginosis
Metronidazole
A 30 year old woman presents with vulval pruritus and a thin white discharge. Microscopy reveals the presence of a flagellated protozoan.
diagnose and managment
Trichomoniasis
Metronidazole
A 30 year old woman presents with vulval pruritus and a thick white discharge she describes as “like cottage cheese”.
diagnose and managment
Candidiasis
Fluconazole + clotrimazole cream
A 30 year old woman presents with abdominal pain and vaginal discharge. Examination reveals generalised tenderness and pain on cervical motion. She does not use contraception. Pregnancy test is negative.
diagnose and managment
Pelvic inflammatory disease
IM Ceftriaxone 500mg single dose followed by oral doxycycline 100mg twice daily plus Metronidazole 400mg twice daily for 14 days
Treatment genital warts
podophyllin cream, cryotherapy
most common vulval pathology worldwide
Trichomonas vaginalis
vulval parasite
Trichomonas vaginalis
treatment for PID
IM ceftriaxone 500mg single dose, oral doxycyline 100mg BD 2/52, oral metronidazole 400mg BD 2/52
20 year old man has just returned from Thailand, he has been having non-bloody diarrhoea 5 times/day for 5 days associated with crampy abdo pain.
salmonella entiridis
20 year old man has just returned from Thailand, he has been having non-bloody diarrhoea 5 times/day for 5 days associated with crampy abdo pain.
E Coli
most common cause of Traveller’s diarrhoea
20 year old man present to the OOH GP at midnight, he woke in the night with vomiting, abdominal pain and profuse diarrhoea. He recalls reheating a Chinese takeaway a few hours prior.
Bacilius cereus
Found in rice, symptoms develop in 4-8 hours hours
Whilst camping in rural Peru, a 30 year old woman becomes unwell with a one week history of abdo pain, vomiting and bloody diarrhoea 10x day
Shigella
bloody diarrhoea + VOMITING
Whilst camping in rural Peru, a 30 year old woman becomes unwell with a one week history of abdominal pain and watery diarrhoea 10x day. The stool is described as rice-water.
Vibrio cholerae
rice water stool
A 30 year old woman presents with diarrhoea and abdo pain. She recalls attending a barbecue 3 days ago where chicken was served.
Salmonella enteritidis
non-bloody diarrhoea and chicken
gastroenteritis salmonella
A 30 year old woman presents with bloody diarrhoea and abdo pain. She recalls attending a barbecue 3 days ago where chicken was served.
Campylobacter
bloody diarrhoea and chicken
A 55 year old man on long-term antibiotics for a chronic joint infection begins to suffer with severe diarrhoea, abdominal pain and feeling unwell.
C. diff
A hospital ward has been shut due to an epidemic of diarrhoea and vomiting, leaving many patients dehydrated.
Norovirus
mobile trophozoites
Entamoeba histolytica
mnemonic for causes of bloody diarrhoea
CHES Campylobacter Haemorrhagic E coli Entamoeba histolytica Shigella Salmonella - rarely/causes non-bloody
fever, abdo pain, diarrhoea, headache, rash on torso, low heart rate, enlarged liver.
dx and rx
typhoid fever
ciprofloxacin
40 year old woman presents with diarrhoea, large amounts of offensive flatulence and abdominal pain. Stool microscopy reveals mobile trophozoites.
Entamoeba histolytica
A 60 year old renal transplant patient presents to ED with severe diarrhoea. Kinyoun acid fast stain of stool reveals oocysts.
Cryptosporidia
A 55 year old man on long-term antibiotics for a chronic joint infection begins to suffer with severe diarrhoea, abdominal pain and feeling unwell.
C. Difficile
A 30 year old has recently returned from El Salvador presenting with fever and abdominal pain. On examination splenomegaly is noted. Bloods show WCC 3.0.
Salmonella typhi
A hospital ward has been shut due to an epidemic of diarrhoea and vomiting, leaving many patients dehydrated.
Norovirus
pathagnomonic for entamoeba histolytica
mobile trophozoites
what is entamoeba histolytica
an anaerobic parasitic amoebozoan
pathagnomonic for cryptosporidium
acid fast stain reveals oocysts
list 3 protozoa and one key symptom of each
entamoeba histolytica - excessive flatulence w/diarrhoea
giardiasis lamblia - v. foul smelling diarrhoea
cryptosporidium - diarrhoea
list types of salmonella and brief effects of each
Salmonella enteritidis = gastroenteritis
Salmonella typhi = typhoid fever
Salmonella paratyphi = paratyphoid fever
Rose spots - causative organism - disease
Salmonella typhi - typhoid fever
Ricewater Stools
Cholera
c diff rx 1st and 2nd line
PO metronidazole, 2nd line PO vancomycin.
MRSA rx
vancomycin
A diabetic with long-standing infected uclers on his right ankle complains of persistent pain. MRI shows bone marrow oedema of the distal tibia.
Osteomyelitis
A 50 year old man presents with with an acutely swollen, red, painful left knee fixed at 10 degrees flexion. He is unable to weight bear. He is known to have a total knee replacement on that side. He has recently been treated for CAP.
Septic arthritis
elderly patient has new confusion
dip the urine - check for UTI
A 60 year old has recently had a Hartmann’s procedure for CRC. The stoma site is not yet fully healed, with surrounding erythema and yellow discharge. Inflammatory markers are raised.
Wound infection
Why is septic arthritis common in children?
Very high blood supply to the bones
Why are prosthetic joints a common site for septic arthritis?
They have no immune system!
Why do children hold their hip out in a flexed externally rotate position in septic arthritis?
it makes the joint capsule space as large as possible
What is prosthetic joint failure?
When there is a mechanical failure of the joint
most likely organism of (superficial) wound infection and tx
staph. aureus
treat w/ flucloxacillin
what is superficial and deep wound infection?
give respective treatments
superficial = infection of skin and subcutaeneous tissue, cellulitis. S.aureus most likely organism. Tx = flucloxacillin
deep = infection down to fascial and muscle layers or beyond into organ spaces, failure of healing. Rx = Broad spectrum antibiotics as per guidelines for organ systems involved.
Rx = IV antibiotics and surgery (arthroscopic washout)
condition?
Septic Arthritis
Most common pathogen causing UTI
Escherichia coli
2nd most common pathogen causing UTI, frequently seen in young women
Staphlyococcus saprophyticus
Pathogen associated with recurrent UTI and staghorn calculi
Proteus Mirabilis
Sign most associated with coliform infection on urine dipstick testing
BONUS: what does coliform mean?
Nitrate positive
coliform: rod-shaped Gram-negative non-spore forming and motile or non-motile bacteria which can ferment lactose with the production of acid and gas
20 year old man presents with right iliac fossa pain. On examination there is RIF tenderness and guarding. WCC 16, CRP 120
dx and tx
Appendicitis – urgent surgery
A 5 year old child presents unwell with a painful hip, unable to weight bear. On examination the hip is held in flexed externally rotated position. Temperature 39.5. WCC 18 CRP 150.
Septic arthritis
70 year old woman presents with confusion and suprapubic tenderness. Urine dipstick is positive for leukocytes and nitrates. WCC 12, CRP 20
UTI – trimethoprim
40 year old woman presents with abdominal pain and dysuria. On examination there was right renal angle tenderness. Pregnancy test negative. Pyuria is present.
Pyelonephritis – co-amoxiclav + gentamicin
Renal angle tenderness on examination
pyelonephritis
sudden severe loin to groin pain. 10/10. Worse on any movement.
give name and treatment
renal colic - renal stones
conservative/lithotripsy/PCNL
percutaneous nephrolithotomy - surgical removal of stones
30 year old woman presents with headache, neck stiffness and fever. Lumbar puncture shows low glucose, high protein and WCC 100 with 90% polymorphs.
Bacterial meningitis
30 year old woman presents with headache, neck stiffness and fever progressive over 5 days. Lumbar puncture shows normal glucose, normal protein with WCC 100 90% lymphocytic infiltrate.
Viral meningitis
A 30 year old Somalian woman presents with headache, worsening fever and neck stiffness. Lumbar puncture shows high levels of glucose, protein and white cells, with a lymphocytic predominance.
TB meningitis
A 30 year old woman presents checks in to ED complaining of headache, fever and neck stiffness. The receptionist calls you to the waiting room urgently, the patient is seizing. Once stable, she tells you she had been unwell with the flu recently
Viral Encephalitis
Seizing is far more common in encephalitis
Preceding prodromal illness is more common in encephalitis
LOW GLUCOSE LP
BACTERIAL
List time frames to consider to distinguish types of meningitis
hours
days
weeks to months
30 year old man from Swaziland presents with persistent cough, feeling hot and night sweats. He occasionally brings up blood. He has lost 10kg in the last 6 months. He is a smoker.
TB (respiratory) highest in swaziland
How does glucose vary for the different types of meningitis on LP?
Low Glucose - Bacterial (bacteria uses it)
Low Glucose - TB
Normal (similar to plasma) Glucose - Viral
How do white cells vary for the different types of meningitis on LP?
Polymorphs - Bacterial
Lymphocytes - Viral, TB
How does protein content vary for the different types of meningitis on LP?
High protein - Bacterial
High protein - TB
Low protein - Viral (small small amounts of protein in viruses)
Why do we do CT Head in meningitis?
Exclude any other causes of symptoms, to reassure us.
80 year old known COPD patient presents to ED with SOB, wheeze, cough and fever. O2 82% RA, RR 28.
treat
IV Co-amoxiclav + clarithromycin, IV hydrocortisone, salbutamol and ipratropium nebuliser
(need to improve lung function as well as treat infection)
72 year old woman diagnosed with meningitis. CSF culture shows gram positive rods with tumbling motility.
dx and mx?
Listeria
IV ceftriaxone + ampicillin
Newborn baby is diagnosed with meningitis. Gram negative rods are seen in the CSF
dx and mx?
E. coli
IV ceftriaxone
18 year old is diagnosed with meningitis.
dx and mx?
N. meningitidis
IV ceftriaxone
50 year old man is diagnosed with meningitis. Ziehl-Nielsen stain reveals the organism responsible.
dx and mx?
Mycobacterium tuberculosis
Rifampicin + isoniazid + pyrazinamide + dexamethasone
Gram positive rods with tumbling motility have caused a meningitis - causative organism?
tx?
Listeria
IV ceftriaxone + ampicillin
meningitis: Gram -ve bacilli in a newborn
E coli
meningitis: Gram +ve cocci in a newborn
Group B Strep
meningitis: Gram +ve diplococci in a teenager
Neisseria meningitis
meningitis: gram positive bacilli + motility in elderly and newborns
Listeria
meningitis: Gram –ve coccobacilli in newborns and children
Haemophilus influenzae
Which antimicrobial class inhibits protein synthesis?
Aminoglycosides
AMINO
Which antimicrobial class inhibits cell wall synthesis?
Beta-lactams
Which antimicrobial class inhibits DNA synthesis?
Fluoroquinolones
fluoro-uracil
Which antimicrobial class inhibits folate metabolism?
Sulfonamides
sulFO
FOlate
Give a Beta-lactam
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Ceftriaxone
Give an example of Fluoroquinolones
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Ciprofloxacin
Give an example of Glycopeptide
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Vancomycin
Give an example of Aminoglycoside
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Gentamicin
Give an example of Macrolide
Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Erythromycin
Give an example of Diaminopyrimidines
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Trimethoprim
Give an example of Oxazolidinones
Ceftriaxone Vancomycin Doxycycline Ciprofloxacin Colistin Erythromycin Linezolid Gentamicin Trimethoprim
Linezolid
Give 3 types of beta-lactams?
Penicillins,
cephalosporins,
carbapenems
Where does Tb originate?
Cow..
Factors inducing transmission of Tb
Sputum status of index case (can you see Tb down microscope)
Proximity
Time in high risk area
Susceptibility of exposed person (e.g. PPI lowers stomach acid more likely to get salmonella)
Who is at risk of disseminated Tb?
Young and the immunocompromised
Where does Tb usually enter?
Lung
Sometimes pharynx and lymph nodes
What compound keeps Tb latent?
Anti-TNF
Gold standard of diagnosing Tb?
Culture
Takes 20 days - 8 weeks
Thus we have a lot of empirical therapy before dx confirmed
How sensitive is TB PCR?
60-65% lymph node
40% CSF (Tb meningitis)
How to tell if a granuloma is a TB?
Pus coming out of a granuloma, perhaps in the wall of an abscess
What does whole genome sequencing save time on in Tb Ix?
After culturing Tb you can find the sensitivity by mapping the 4000 genes of it. This saves several weeks as normally you would reculture the positive culture with all the different Abx.
Future of Ix
What are Mantoux test and IGRA for Tb equivalent to?
Equivalent to IgG for Tb.
All it shows is past immune response to Tb.
Note: IGRA misses 1 in 5 cases (low sensitivity)
Definition of Latent Tb.
Positive Mantoux test or IGRA test with no clinical symptoms.
How many cases and deaths of Tb each year?
1.4 million deaths
10 million cases
Ten times less funding than HIV
Features of military Tb?
CXR?
No cough, feeling rotten
Tiny spots all over, apical sparing
How to differentiate pleural Tb and malignancy?
Drain the fluid - lots of lymphocytes, no malignant cells
Where are mediastinal lymph nodes on CXR?
Around the hilae
Cold abscess?
Abscess in lymph node with Tb
It is called cold because if it was staph aureus it would be very hot
How does spinal Tb work?
Starts in bones, destroy, press into the spinal cord
Or
Starts in brain and then spreads to cord. Can become paraplegic.
How to treat CNS and Spinal Tb?
Normal treatment with HIGH dexamethasone.
(Look up in BNF)
High immunosuppression can foster Tb to spread to spinal Tb. It can also mask symptoms until progressed Tb.
May often find meningitis if spreading through cord.
When must you give steroids in Tb?
Spinal Tb Pericarditis Tb (lower inflammation that causes scarring and strangles the heart)
Can give for symptoms
Why multi drug treatment for Tb?
Speed killing
Combat resistance
Who gets longer Tb treatment”
Spinal Tb- 12 months
Intolerant - 1st line - rif and iso for 9 months
Missed doses - if totals 2 weeks must start from beginning
Drug-resistant Tb - long time
How treat latent Tb?
Screen the significantly immunocompromised, especially high steroids
3 months RI
Or 6 months I
Which Tb drug has most interactions?
Rifampicin
What can be given alongside Tb therapy if some symptoms arise?
Vitamin B6
Signs of URTI
Cervical lymph nodes
Coryza
What to do if Pt ill just have exposed camels
MERS - put mask on and isolate
Key point if history in fever in returning traveller
Focus or no focus
Ddx for fever with no focus
Bacterial - typhoid
Parasites - malaria (must be ruled out 3 tests) (low platelets)
Viral - arbovirus (mosquitoes)(dengue common, chikingunya, zika)
Low platelets, returning traveler, fever, no focus
Malaria
Viral
Which disease in fever returning traveller no focus has unusual FBC result.
Typhoid no neutrophilia
Why does Tb not usually present in returning traveller?
Very variable incubation time. Could be 6 months could be 3 years after exposure
Man returned from Delhi, puo
Amoebic liver abscess
What is the difference between thin and thick blood film?
Thin is one cell thick
Thick is many cells
Thin is a blob spread out so one cell thick
Thick is one blob not spread
What is the appearance of malaria blood cells in falciparum malaria
Earphones or signet rings in cells
How to treat typhoid
Ceftriaxone
How to treat malaria
Artesunate
Mortality of Ebola in tropic
Mortality of Lassa
50-70%
Very variable
What disease is around the entire tropics?
Zika virus
How to prevent congenital zika
No babies for 6 months if Male
No babies for 2 months if female