Gram Negs Flashcards
Which organism causes gonorrhoea?
Neisseria Gonorrhoeae
Do N. Gonorrhoeae and N. Meningitidis have polysaccharide capsules?
Only n. meningitidis has a polysaccharide capsule
Do N. Gonorrhoeae and N. Meningitidis have vaccines?
N. meningitidis has vaccines
Polysaccharide for short term protections
Conjugated for long term and infants
How is N. Gonorrhoeae transmitted?
Sexually or perinatally
How is N. meningitidis transmitted?
Respiratory droplets/ close contact
What are the complications of N. gonorrhoeae?
Urethritis in males
Cervicitis & Pelvic inflammatory disease in females
Septic arthritis
Conjunctivitis
Proctitis
Disseminated Gonoccocal infection
How to diagnose n.gonorrhoeae?
PCR of urine samples
Gram stains (males)
Chocolate agar culture
How to prevent gonorrhoea?
Condoms
How to treat gonorrhoea?
IM ceftriaxone and PO azithromycin
How to diagnose N. meningitidis?
Blood / Chocolate agar culture
PCR
What are the complications of n.meningitidis?
Meningitis
Meningococcemia (non-blanching rash)
What is the empirical treatment for meningitis?
Ceftriaxone and vancomycin
How to prevent spread of n.meningitidis?
Ceftriaxone in close contacts
What are the clinical presentations of e.coli?
Diarrhoea
UTI (more common in females)
Neonatal sepsis and meningitis
Gut related sepsis (biliary obstruction or epithelium damage)
Which strains of e. coli are pathogenic?
EHEC, ETEC, EPEC, EIEC, EAEC
What is the serotype for EHEC?
O157:H7
What does EHEC produce and what does it cause?
Shiga toxin
Causes bloody diarrhoea and Haemolytic uraemia syndrome which causes renal failure
What is ETEC the leading cause of?
Bacterial diarrhoea (travellers diarrhoea)
List the commonest causes of UTI.
- E.coli
- Klebsiella, Proteus, Enterococcus
- Pseudomona (nosocomial)
What are the 2 types of salmonella species?
Typhi / paratyphi a,b,c
Enteritidis
Which salmonella species causes typhoid fever?
Typhi and paratyphi a,b,c
What are sources of P. aeruginosa?
Water bodies
How is S. typhi transmitted?
Human-human
Contaminated food and water
How to diagnose S. typhi?
Blood culture
What does S. enteritidis cause
Food poisoning
Acute gastroenteritis
Bacteremia in immunocompromised
What are common sources of S. enteritidis?
Eggs and poultry
What kind of a pathogen is P . aeruginosa?
Opportunistic and nosocomial
How do you treat for P. aeruginosa infections?
Carbapenems & fluoroquinones
What are the clinical features of P. aeruginosa?
Septicaemia
UTI
SSTI
Pneumonia
Keratitis (contact lens)
What is the toxin produced by V. cholerae and how does it exert its effect?
Cholera toxin
‘A’ unit inhibits Na+ and HCO3- uptake and causes hyper secretion of Cl- and HCO3- by epithelial cells, causing extreme water loss
‘B’ unit binds and is immunogenic
What are the clinical presentations of V. cholerae?
Rice water stool and vomitting
How is cholera transmitted?
Faecal oral transmission
What is the treatment and prevention of cholera?
Oral rehydration solution and oral doxycycline
Live and activated vax
Which serotypes of V. cholera carry the cholera toxin?
O1 and O139
What vibrio are a/w seawater and raw seafood?
V. vulnificus and V. parahaemolyticus
Is capsulated or encapsulated haemophilus influenza invasive?
Both are invasive
What does V. vulnificus cause?
Necrotising fasciitis and septicaemia
What does V. parahaemolyticus cause?
Gastroenteritis and SSTI
How to treat haemophilus influenzae?
Co-amoxiclav due to presence of B-lactamase
How do you diagnose Haemophilus influenza?
Chocolate agar culture
What is the vaccine for haemophilus influenza?
Hib vax
What are the clinical presentations of haemophilus influenza?
Arthritis
Epiglottitis
Meningitis
Otitis media
Pneumonia
Sinusitis
Which organism cause pertussis?
Bordetella pertussis
What is the strategy for pertussis vax?
Pregnant women and close family
How do you diagnose pertussis?
PCR
Mercury droplets colonies on culture
What complications do H. pylori cause?
Gastritis causing
Peptic ulcer disease, gastric cancer, gastric MALT lymphoma
How is helicobacter pylori transmitted?
Faecal oral route
What does H. pylori produce?
Urease which neutralises stomach acid
What is the treatment for H. pylori?
3x therapy
Clarithromycin
Amoxicillin
Omeprazole
for clarithromycin resistance:
Metronidazole
Amoxicillin
Omeprazole
How do you diagnose H. pylori?
Invasive: Gastroscopy /rapid urease test
Non-invasive: Urea breath test/ stool antigen test
What are the sources of Campylobacter jejuni?
Poultry and eggs
How is campylobacter jejuni transmitted?
Faecal oral route
What are the post infectious complications of campylobacter jejuni?
Guillian-barre syndrome
reactive arthritis
Both due to molecular mimicry
What are the clinical presentations of campylobacter jejuni?
Fever
Abdominal pain
Bloody diarrhoea
How do you diagnose campylobacter jejuni?
Stool culture
What organism causes syphillis?
Treponema pallidum
What is the treatment for syphillis?
Penicillin G
What entails primary syphillis?
Painless chancre (genital ulcers)
How is treponema palladium detected?
Early lesions
Antibody tests
What entails secondary syphillis?
Scaly rash on palms and soles, lymphadenopathy
What entails congenital syphillis?
Keratitis, deafness and Hutchinson’s teeth
What entails tertiary syphillis?
Gummatous
What entails quaternary syphillis
CVS: myocardial infarction, angina, aneurysm
Neuro: menginovascular syphilis, tables dorsales
What organisms are mainly responsible for water related necrotising fasciitis?
V. vulnifuculus and aeromona
What organisms are mainly responsible for water related SSTIs?
V. aeromonas, PAE, S.aureus and S.pyogenes
What organisms are mainly responsible for meningitis in elderly and infants?
SPN, N.meningitidis
H.influenzae
Patient presents with purulent urethral discharge. What is the causative organism?
N. gonorrhoeae
What organisms are mainly responsible for meningitis in neonates and what is the treatment?
E.coli, S. agalctiae and Listeria
Ceftriaxone, gentamicin and ampicillin
What is the commonest cause of bloody diarrhoea?
EHEC
What organisms cause neonatal conjunctivitis?
Day 1-3: N . gonorrhoeae
Day 3-10: C. Trachomatis
What is the treatment for uncomplicated UTI?
Co-trimoxazole or nitrofurantoin
What is the treatment for complicated UTI?
Ciprofloxacin and co-amoxiclav
