Clinical Microbiology — SCT II [Vol. 2] Flashcards
What kind of immunity develops after Neisseria gonorrhoeae infection?
Partial immunity of short duration; no protection from reinfection
Specify at least 2 of the most important manifestations of disseminated gonorrhoeal infections
- Arthritis
- Skin lesion
- Endocarditis
- Meningitis
What is the major manifestations of Neisseria gonorrhoeae infection in newborns? How can it be prevented?
Blenorrhoea (opthalmia) neonatorum; silver acetate eye drops or erythromycin ointment
Mention at least 3 major virulence factors of Neisseria gonorrhoeae
- Pilus
- Outer membrane proteins
- LOS (Lipooligosaccharide)
- IgA protease
Mention at least 2 major virulence factors Neisseria meningitidis
- Polysaccharide capsule
- LOS (Lipooligosaccharide)
- IgA protease
What is the site of entry of Neisseria meningitidis infection? Which diseases are caused by this bacterium?
The site of entry is the nasopharynx (transmitted by airborne droplets).
Meningococcemia and acute (purulent) bacterial meningitis
What kinds of prophylactic measures are available against diseases caused by Neisseria meningitidis?
Chemoprophylaxis: rifampin or ciprofloxacin
Vaccination: Capsular polysaccharide (types A, C, Y and W135).
Vaccine against type B: Contains different recombinant proteins
Which rapid diagnostic methods can be used in the presumptive diagnosis of purulent bacterial meningitis?
- Gram or methylene blue stain of CSF sediment
- Demonstration of bacterial capsular antigens by latex agglutination (from CSF)
- Polymerase chain reaction (PCR)
What does the vaccine against Haemophilus influenzae contain?
Type B capsular polysaccharide conjugated to a carrier protein
Which are the portals of entry of Bacillus anthracis?
- Skin
- Lungs
- Gastrointestinal tract
Mention 3 important bacteria involved in nosocomial (hospital-acquired) infections
- Staphylococcus aureus
- Enterococcus faecalis
- Pseudomonas aeruginosa
- Eschericia coli
- Clostridioides difficile
Mention four E. coli pathogenic groups involved in enteric diseases
- Enteropathogenic E. coli (EPEC)
- Enterotoxic E. coli (ETEC)
- Enteroinvasive E. coli (EIEC)
- Enterohemorrhagic E. coli (EHEC)
- Enteroaggregative E. coli (EAggEC)
What are the most important extraintestinal infections caused by E. coli? Mention at least 3 of them
- Urinary tract infections
- Neonatal meningitis
- Nosocomial wound infections
The most frequent causative agent of urinary tract infections is:
Escherichia coli
Which 2 diseases are caused by E. coli O157:H7?
Hemorrhagic colitis +/- HUS (hemolytic uraemic syndrome)
What is the reservoir of Salmonella typhi?
Humans (with disease, or healthy carriers)
Which bacteria cause most frequently typhoid fever and enteric fever, respectively?
Salmenoella Typhi (typhoid)
Salmonella Paratyphi A, B, C (enteric fever)
When typhoid fever is suspected, what kinds of clinical samples should be used to isolate the causative agent in the first 2 weeks of the disease?
Blood, bone marrow
What is the route of infection in Salmonella gastroenteritis?
Ingestion of contaminated food (such as eggs, cream, mayonnaise, creamed foods, etc.) containing a sufficient number of Salmonella.
Which antibacterial drugs should be administered in gastroenteritis caused by salmonella
Antibiotics are usually contraindicated unless the infection is generalized.
In case of extraintestinal infection (very young, very old or immunosuppressed patients):
1. Trimethoprim/sulfamethoxazole
2. Ceftriaxone
3. Ciprofloxacin
List the 4 Shigella species causing human disease
- Shigella dysenteriae
- S. flexneri
- S. boydii
- S. sonnei
Mention 2 bacterial species belonging to different genera that cause bacillary dysentery
- Shigella dysenteriae
- Shigella flexneri
- Shigella boydii
- Shigella sonnei
- Enteroinvasive E. coli (EIEC)
Mention 3 bacterial species belonging to different genera that cause enteritis or enterocolitis
- Campylobacter jejuni
- Escherichia coli
- Salmonella enteritidis
- Shigella
- Yersinia enterocolitica
Mention 2 bacteria causing intestinal infections which have animal reservoirs
- Salmonella (not Typhi and Paratyphi!)
- Campylobacter jejuni
- Yersinia enterocolitica
- Listeria monocytogenes
- E. coli O157
What are the modes of transmission of the 2 different forms of plague?
Bubonic Plague: transmitted by the bite of infected rat fleas from rats to humans
Primary pneumonic plague: spreads directly from human to human via respiratory droplets