Bacterial infections Flashcards
What is Tularaemia ?
(The rabbit fever)
~Caused by Francisella tularensis
~Symptoms may include fever, skin ulcers, and enlarged lymph nodes.
~Occasionally, pneumonia or a throat
~ Spread: tick bite
deer flies, contact with infected animals and or contaminated water
Meningococcal serogroups?
At least 12 serotypes
#A, B and C account for about 90%
#Recent outbreaks of group Y and W135 strains
#Serogroup B (MenB) is the predominant in UK followed by serogroups W and Y
#Serogroup A is rare in the UK but more common in Africa and Asia
What are the virulence factors of N. meningitidis?
1- Polysaccharide capsule
2- Pili for attachment
3- Outer membrane proteins (PorA, PorB, and Opa ) for adhesion and invasion.
4- Lipooligosaccharide (LOS) endotoxin
5- IgA1 protease
IP for meningococcal disease?
3-4 days
Meningococcal rash?
non-blanching petechial or purpuric
Spectrum of meningococcal diseases?
1- Meningitis
2- Meningococcal septicemia
3- Meningococcemia
4- Pneumonia
5- Conjunctivitis
T/F
Meningococcus is a Hazard Group 3 organism ?
False
hazard group 2 and samples should be Process at Containment Level 2
selective media for N meningitis and gonorrhoea?
Thayer Martin for gonorrhoea and GC media for meningococci
Colony appearance of meningococci?
Small grey colonies on blood or chocolate agar
#Grow best on 5-10% CO2 35-37C
#Catalase and Oxidase positive
# GC agar is the selective media
Biochemical characteristics of meningococcus?
1-Oxidase-positive
2- Catalase-positive
3- Glucose and maltose fermentation positive (MeninGococci - Maltose and Glucose; Gonococci - Glucose only)
treatment of meningococca disease ?
Mild-moderate allergy - Meropenem 2gms TDS
IV Ceftriaxone 2 grams IV BD
#Severe allergy/anaphylaxis - Chloramphenicol 25 mg/kg intravenously every 6 hours
Meningococal prophylaxis (PEP)
Ciprofloxacin 500 mg po stat
or rifampicin 600 mg po bd for 2 days
Meningococcal UK vaccination protocol?
MenB vaccine (Bexsero or Trumenba):
Routine for infants (3 doses at 2, 4, and 12 months)
Catch-up for adolescents and high-risk groups
#MenACWY vaccine:
Routine immunization for adolescents (single dose at 14 years)
University entrants up to 25 years of age
#MenC vaccine:
Now part of the Hib/MenC combination vaccine given at 12 months
What is the causative agent for Enteric fever?
Salmonella enterica
1- Serotype typhi
2-Serotype para typhi A, B, C
What is the Multidrug-resistant Enteric Fever (MDR EF)?
R to ampicillin, chloramphenicol and co-trimoxazole.
What is the Extensively drug -resistant Enteric Fever (XDR EF)?
it is MDR EF with additional resistance to ciprofloxacin and third-generation cephalosporins.
What tests are available for H pylori?
1-Urea breath test-UBT
2-Stool antigen test -SAT
3- Antibody test- serology HiG
4-Microscopy and culture of gastric biopsy
5 Histology
6- PCR to detect clarithromycin resistance
T/F
H pylori are immotile bacteria under microscope??
It has rapid, darting (corkscrew) mobility using flagella.
what is the H pylori selective media?
Oxoid Dents media
[blood agar with dent supplement (vancomycin, trimethoprim, cefsoludin and amphotericin B)]
Also: can use Urea Agar (Christenson’s broth) for detection of urease
H pylori incubation ?
Microaerophilic
3-5% H2
At 35 degrees C
For 10 days
What is the definition of Extended-spectrum beta-lactamase (ESBL) enteric fever ?
It is the Salmonella spp that is resistant to third-generation cephalosporins but susceptible to at least one of :
1- chloramphenicol , Or:
2- co-trimoxazole, Or:
3- ciprofloxacin.
What are the pathogenic proteus spp?
Proteus mirabilis
Proteus vulgaris
Proteus penneri
erecurrennt Proteus UTI can lead to struvite stones?
T
it can hydrolyze urea and raise urinary pH. Alkalinization
What is the proteus intrinsic resistence pattern??
1- All Proteus spp is intrinsically R to:
- nitrofurantoin
- colistin/polymyxin
- tetracycline.
2- Proteus penneri and vulgaris also intrinsically resistant to:
- amoxicillin
- 1st & 2nd gen cephalopsorin.
