4. Group B: Streptococcus agalactiae
• Regularly resides in human
vagina, pharynx, and large intestine
• Can be transferred to infant during
delivery and cause severe infection
– Pregnant women should be screened and
treated
• Wound and skin infections and
endocarditis in debilitated people
5. Deepa Babin 5
LAB DIAGNOSIS
Cultivation and diagnosis
ensure proper treatment
to prevent possible
complications
Rapid diagnostic tests
based on monoclonal
antibodies that react with
C-carbohydrates
Culture using bacitracin
disc test, CAMP
test, Hippurate hydrolysis
6. Deepa Babin 6
CAMP Test- S.agalactiae
• By Christie, Atkins, and Munch-Peterson
• In the CAMP test, group B streptococci release a soluble factor
(CAMP factor) that acts synergistically with the -hemolysin of
Staphylococcus aureus.
• A strain of -hemolysin producing Staphylococcus aureus is
inoculated down the center of a sheep blood agar plate.
• A single streak of an isolate to be identified is inoculated
perpendicular to the S. aureus streak to within 3-4 mm of the S.
aureus streak.
• The blood agar plate is then incubated overnight in an 35-37oC air
incubator
• If a large arrowhead zone of enhanced -hemolysis develops
between the unknown isolate and S. aureus the unknown isolate
is group B Streptococcus.
8. • Groups C –Strep equisimilis species
– Common animal flora, frequently isolated from upper
respiratory;
pharyngitis,osteomylitis,glomerulonephritis, bactere
mia,brain abscess,puerperal sepsis
– Strep equisimilis- source of streptokinase
Group G,H,K O,R:
Group G- commensals of throat of man monkey
dogs
Occationaly-tonsilitis,endocarditis,UTI
Group H and K- Endocarditis
Group O- tonsilitis,endocarditis
Group R- Pigs(Septicemia,meningitis)
9. Treatment
• Groups A and B are treated with
Penicillin
• Long-term penicillin prophylaxis for
people with a history of rheumatic
fever or recurrent strep throat
10. Deepa Babin 10
Group D (Enterococci)
• Two groups-
Enterococcal gp and
Non Enterococcal
gp
– Enterococcus
faecalis, E.
faecium, E. durans
– Strep bovis,Strep
equinus- Non
Enterococcal gp
11. Deepa Babin 11
Group D (Enterococci)
• -Normal colonists of human large intestine,Genital
tract and saliva
– Cause opportunistic urinary, wound, and skin
infections, particularly in debilitated persons
– Intra abdominal abscess complicating
diverticulitis and peritonitis
12. Lab diagnosis
• Bile Esculin hydrolysis
– Ability to grow in 40% bile and hydrolyze Esculin
are features of Enterococci that possess Group D
antigen
• Growth in 6.5% NaCl broth
– Differentiates Group D streptococci from
enterococci
13. Treatment
• Treatment-Penicillin- Resistance(enterococci)
• P –R ,CHOICE IS VANCOMYCIN
• VRE- Vancomycin resitant Enterococci
• Enterococcal treatment usually requires
combined therap
• Cephalosporin's are inherently resistant
for Enterococci
14. Deepa Babin 14
Viridans Group
• Bacteremia, meningitis, abdominal infection, tooth
abscesses
• Most serious infection – Sub Acute Endocarditis – Blood-
borne bacteria settle and grow on heart lining or valves
• S. mutans produce slime layers that adhere to teeth, basis
for plaque
• Involved in dental caries
• Persons with pre existing heart conditions should receive
prophylactic antibiotics before surgery or dental
procedures
• Persons with pre existing heart disease are at high risk
• Colonization of heart by forming biofilms