Hemolytic Streptococci- Group A, B, C, D and F
| A | Streptococcus agalactiae | |
| B |
Streptococcus bovis |
|
| C |
Streptococcus pneumoniae |
|
| D |
Streptococcus pyogenes |
A patient with colorectal cancer develops septicemia complicated by endocarditis. You would expect the blood cultures to grow?
| A |
Streptococcus agalactiae |
|
| B |
Streptococcus bovis |
|
| C |
Streptococcus pneumoniae |
|
| D |
Streptococcus pyogenes |
Streptococcus bovis is a Group D streptococcus.
There is a significant association between S. bovis bacteremia and endocarditis with carcinoma of the colon and other colonic diseases.
Every patient with S. bovis bacteremia should undergo gastrointestinal and cardiac evaluation.
Up to 50% of patients with S. bovis bacteremia are reported to have underlying colonic malignancies.
In another study, 25-50% of cases of S. bovis bacteremia were associated with endocarditis, especially in patients with preexisting valvular lesions.
S. pneumoniae infections are also more frequent and unusually severe in patients with sickle cell anemia, multiple myeloma, alcoholism, and hypogammaglobulinemia. S. pneumoniae is now the leading cause of invasive bacterial respiratory disease in patients with AIDS.
A 25 year old woman had premature rupture of membranes and delivered a male child became lethargic and apneic on the 1st day and went into shock. The mother had a previous history of abortion 1 year back. On culture, her vaginal swab growth of a hemolytic colonies on blood agar was found. On staining these were found to be gram positive cocci. Which of the following is the most likely etiological agent :
| A | Streptococcus pyogenes | |
| B |
Streptococcus agalactiae |
|
| C |
Peptostreptococci |
|
| D |
Enterococcus faecalis |
Ans. is b i.e. Streptococcus agalactiae
Streptocr,rrn’ (agalactiae) infection is characterised by :
- Asymptomatic bacteremia to septic shock (as is the case here).
- Early onset disease may present at birth, and generally within 6 hours of birth (patient is presenting here on the first day).
- In utero infection may result in fetal asphyxia, coma or shock.
- In 10% of infants with early onset disease, meningitis occurs.
- Diagnosis is made by isolation and identification of organism from sterile site.
- The demonstration of gram positive organism in pairs or chain in buffy coat or other sterile fluid indicates infection.
- Drug of Choice : Penicillin G./ Ampicillin
| A | Streptococcus agalactae | |
| B |
Enterococcus fecalis |
|
| C |
Streptococcus bovis |
|
| D |
Streptococcus pneumoniae |
Ans. is ‘b’ i.e., Enterococcus fecalis
Enterococcus ‑
- It belongs to lancefields’s group ‘FY streptococci
Note – Enterococci grow in the presence of bile and hydrolyze esculine —-> bile esculin positive.
| A | Strep agalactiae | |
| B |
Strep pneumoniae |
|
| C |
Enterococcus |
|
| D |
Strep bovis |
Ans. is ‘c’ i.e., Enterococcus
The bacteria in this question is showing growth in 6.5% NaC1, non bile senstive (ie growing in the presence of bile) and showing 3 hemolysis, Enterococci have all these features.
| A |
Staphylococci |
|
| B |
E. Coli |
|
| C |
Strept. agalactiae |
|
| D |
Hemophilus |
Ans. is ‘c’ i.e., Strept. agalactiae
Neonatal meningitis acquired during passage through birth canal is due to –
| A |
Streptococcus agalactiae |
|
| B |
S. equisimilus |
|
| C |
S. pyogenes |
|
| D |
Pnemococci |
Ans. is ‘a’ i.e., Streptococcus agalactiae
. Str agalactiae a grp B streptococcus is the single most common cause of neonatal meningitis in the west.
. It produces two types of infection in the new born :‑
– Early onset (within a week of birth) —> Infection is acquired from the maternal vagina
– Late onset (2nd to 12th weeks) –> Infection is obtained from the environment
| A | Streptococcus pyogenes | |
| B |
Streptococcus agalactacea |
|
| C |
Enterococcus fecalis |
|
| D |
Staphylococcus aureus |
Ans. is ‘b’ i.e., Streptococcus agalactiae
A 25-year-old woman had premature rupture of membranes and delivered a male child who became lethargic and apneic on the first day of birth and went into shock. The mother had a previous history of abortion 1 year back. On vaginal swab culture growth of β-haemolytic colonies on blood agar was found. On staining these were found to be gram-positive cocci. Which of the following is the most likely etiological agent –
| A |
Streptococcus pyogenes |
|
| B |
Streptococcus agalactiae |
|
| C |
Peptostreptococci |
|
| D |
Enterococcus faecum |
Ans. is ‘b’ i.e., Streptococcus Agalactiae
`Group B streptococci are the commonest gram-positive agents responsible for early-onset neonatal pyogenic infections and are usually clinically apparent within the first 24 hours of life’. — Nelson
Presence of hemolytic colonies on blood agar (9hemolysis) and gram-positive cocci in smears is almost diagnostic of Group B hemolytic streptococci infection (streptococcus agalactiae).
The following bacteria are most often associated with acute neonatal meningitis except –
| A |
Escherichia coli |
|
| B |
Streptococcus agalactiae |
|
| C |
Neisseria meningitidis |
|
| D |
Listeria monocytogenes |
Ans. is ‘c’ i.e., N. Meningitides
