p.22
General Characteristics of Streptococcus
What is the characteristic of β-hemolytic Streptococci?
Complete lysis of RBC, resulting in a clear zone around colonies.
p.7
Post-Streptococcal Complications
What are potential complications of Streptococcal infections?
Bone and joint infections, meningitis, and endocarditis.
p.9
Post-Streptococcal Complications
What is ARF?
An autoimmune disease characterized by inflammatory lesions involving the heart valves, joints, subcutaneous tissues, and central nervous system.
p.6
Clinical Features of Streptococcal Infections
What type of infections can group A Streptococcus cause?
Skin and soft tissue infections.
p.13
Classification of Streptococci
What type of Lancefield antigens do Streptococcus bovis have?
Lancefield antigens negative.
p.27
Laboratory Diagnosis of Streptococcal Infections
What test is used for detecting Streptococcus pneumoniae from CSF and sputum?
Quellung test (capsular swelling test).
p.12
Epidemiology and Transmission of Group A Streptococcus
What are some risk factors for GBS infections?
Premature rupture of membranes, prolonged labor, and preterm labor.
p.23
Laboratory Diagnosis of Streptococcal Infections
What is the procedure for the bacitracin susceptibility test?
Use a bacitracin antibiotic disc on blood agar with the test organism and incubate overnight at 35-37°C.
p.15
Virulence Factors of Streptococcus pneumoniae
What types of enzymes are produced by S. pneumoniae?
Neuraminidase and protease.
p.4
Virulence Factors of Streptococcus pyogenes
What are the effects of the erythrogenic toxin?
It causes inflammation, fever, shock, and localized erythematous reactions (rash).
p.21
Laboratory Diagnosis of Streptococcal Infections
What is the appearance of colonies for Gram-positive cocci?
Gray-whitish and glistening, pin-point/large/mucoid/buttery.
p.16
Epidemiology and Transmission of Group A Streptococcus
What is a common mode of transmission for pneumococcal infections?
Inhalation of respiratory droplets.
p.29
Virulence Factors of Streptococcus pyogenes
What is the increasing concern regarding erythromycin in the treatment of GAS?
Resistance to erythromycin is increasing.
p.18
Post-Streptococcal Complications
What is subacute bacterial endocarditis (SBE)?
A condition that can be caused by viridans streptococci.
p.5
Clinical Features of Streptococcal Infections
What clinical features are associated with suppurative infections caused by GAS?
URT infections such as pharyngitis and tonsillitis (sore throat).
p.12
Clinical Features of Streptococcal Infections
What are the clinical features of Group B Streptococcus (GBS) infections?
Neonatal sepsis, meningitis, and pneumonia.
p.23
Laboratory Diagnosis of Streptococcal Infections
What does a bacitracin susceptibility test differentiate?
It differentiates Group A Streptococcus (S. pyogenes) from other β-hemolytic streptococci (Group B, C, G).
p.23
Laboratory Diagnosis of Streptococcal Infections
What indicates susceptibility to bacitracin in the test?
A zone of inhibition around the disc.
p.31
General Characteristics of Streptococcus
Is there a vaccine available for Viridians Streptococci?
No, a vaccine is not available.
p.8
Clinical Features of Streptococcal Infections
What are the symptoms of scarlet fever?
Pharyngitis, redness of buccal mucosa, punctuate hemorrhage, strawberry tongue, and a diffuse red sandpaper rash.
p.4
Virulence Factors of Streptococcus pyogenes
What is the function of M protein in Streptococcus pyogenes?
It aids in evading the immune response and inhibiting phagocytosis.
p.6
Clinical Features of Streptococcal Infections
What is the primary cause of sore throat?
Group A Streptococcus (S. pyogenes).
p.17
Clinical Features of Streptococcal Infections
What is the causative agent of pneumococcal lobar pneumonia?
Streptococcus pneumoniae.
p.9
Post-Streptococcal Complications
What are the common symptoms of rheumatic fever?
Fever and pain in the joints.
p.29
Post-Streptococcal Complications
What is a complication associated with GAS (S. pyogenes)?
Acute rheumatic fever (ARF).
p.25
Laboratory Diagnosis of Streptococcal Infections
What is the result of a positive CAMP test?
An arrowhead shape of strong beta hemolysin.
p.28
Laboratory Diagnosis of Streptococcal Infections
What is the significance of the 6.5% NaCl growth test?
It indicates Enterococcus positivity.
p.8
Post-Streptococcal Complications
What role do genetic factors play in acute rheumatic fever?
They play an important role in developing the disease.
p.24
Laboratory Diagnosis of Streptococcal Infections
What is the purpose of the CAMP test?
To differentiate Group B Streptococcus (S. agalactiae) from Group A Streptococcus (S. pyogenes).
p.17
Clinical Features of Streptococcal Infections
What type of pneumonia is associated with S. pneumoniae?
Pneumococcal broncho pneumonia.
p.7
Epidemiology and Transmission of Group A Streptococcus
What is a common source of infection in post-operative and burn wound infections?
Hospital staff and patients with pharyngitis.
p.8
Clinical Features of Streptococcal Infections
What are the initial symptoms of necrotizing fasciitis?
Cellulitis followed by bullae, gangrene, systemic toxicity, and multiorgan failure.
p.26
Laboratory Diagnosis of Streptococcal Infections
What type of hemolytic streptococci does the Optochin susceptibility test involve?
α/γ hemolytic streptococci.
p.4
Virulence Factors of Streptococcus pyogenes
What is the role of the capsule in Streptococcus pyogenes?
It helps in immunological disguise and inhibits phagocytosis.
p.9
Post-Streptococcal Complications
What causes damage in acute glomerulonephritis?
Immune complex deposition on glomerular basement membrane.
p.16
Epidemiology and Transmission of Group A Streptococcus
Which groups are at higher risk for pneumococcal infections?
Smokers, alcoholics, individuals with viral RT infections, bronchitis, COPD, CHF, asthmatics, pulmonary edema, malnutrition, complement deficiency, and splenectomy.
p.14
General Characteristics of Streptococcus
What type of bacteria is characterized by Gram-positive diplococci?
Streptococcus pneumoniae.
p.32
General Characteristics of Streptococcus
What is the significance of the term 'cocci' in Streptococci?
It refers to their spherical shape.
p.13
General Characteristics of Streptococcus
How do Streptococcus pneumoniae typically appear under a microscope?
Usually as pairs of cocci (diplococci), but may also occur singly and in short chains.
p.3
Virulence Factors of Streptococcus pyogenes
What is the function of Streptokinase?
It converts plasminogen to plasmin, which digests fibrin.
p.29
Treatment and Prevention of Streptococcal Infections
What should be done for all Streptococci isolates except S. pyogenes?
Antibiotic susceptibility testing.
p.3
Virulence Factors of Streptococcus pyogenes
What is the role of C5a peptidase in Streptococcus pyogenes?
It degrades the C5a complement component.
p.5
Epidemiology and Transmission of Group A Streptococcus
What is the primary source of infection for Group A Streptococcus (GAS)?
Human nasopharyngeal carriers (<5%) and infected breast tips of cows (contaminate milk).
p.5
Epidemiology and Transmission of Group A Streptococcus
What are the modes of transmission for GAS?
Inhalation of respiratory droplets and direct contact with infected secretions/mucosa.
p.18
Clinical Features of Streptococcal Infections
What dental issues can viridans streptococci contribute to?
Dental plaque and dental caries.
p.28
General Characteristics of Streptococcus
What is the hemolytic pattern of S. viridans?
Alpha hemolytic and negative for all the tests listed.
p.1
Classification of Streptococci
Which species is classified as Group B β-hemolytic Streptococcus?
Streptococcus agalactiae.
p.27
Laboratory Diagnosis of Streptococcal Infections
How do Viridans streptococci respond to optochin?
They are not inhibited by optochin.
p.13
General Characteristics of Streptococcus
What are the characteristics of Streptococcus pneumoniae?
Capsulated, non-spore formers, and non-motile.
p.27
Laboratory Diagnosis of Streptococcal Infections
What is a common issue when interpreting the Quellung test?
Cross reactivity with E. coli, Klebsiella, Hib, and some Viridans streptococci.
p.31
Treatment and Prevention of Streptococcal Infections
What is recommended for patients before dental extraction or surgery to prevent infections?
Chemoprophylaxis with Ampicillin, erythromycin, or vancomycin.
p.4
Virulence Factors of Streptococcus pyogenes
What type of toxin is the erythrogenic toxin produced by Streptococcus pyogenes?
It is a super-antigen phage coded toxin.
p.26
Laboratory Diagnosis of Streptococcal Infections
What is the purpose of the Optochin disc in the susceptibility test?
To observe the zone of inhibition around the disc.
p.29
Treatment and Prevention of Streptococcal Infections
What combination of antibiotics is used for serious infections caused by GBS (S. agalactiae)?
Penicillin + aminoglycoside.
p.8
Post-Streptococcal Complications
What is acute rheumatic fever?
An autoimmune disease where antibodies to M protein cross-react with heart muscle, leading to damage.
p.8
Post-Streptococcal Complications
What are the potential consequences of repeated attacks by Group A Streptococcus?
Rheumatic heart disease followed by congestive heart failure.
p.16
Virulence Factors of Streptococcus pyogenes
What are the stages of pathogenesis in pneumococcal infection?
Multiplication, inflammation, accumulation of fluid and inflammatory cells, consolidation of the lung, and complete resolution of inflammation.
p.19
General Characteristics of Streptococcus
What is a unique growth characteristic of Enterococcus?
All strains grow in a broth containing 6.5% NaCl and hydrolyze esculin in the presence of 40% bile salts.
p.20
Laboratory Diagnosis of Streptococcal Infections
What type of culture medium is used for blood culture?
Blood agar supplemented with 5% sheep/horse blood.
p.1
Clinical Features of Streptococcal Infections
Which group of Streptococci is associated with pharyngitis?
Groups C, F, and G (β-hemolytic).
p.6
Clinical Features of Streptococcal Infections
What are the characteristics of Impetigo?
Pustular skin lesions on the face and lower extremities; highly contagious.
p.2
Classification of Streptococci
How are streptococci classified on blood agar?
Based on their hemolytic reaction.
p.11
Virulence Factors of Streptococcus pyogenes
What is the significance of capsular polysaccharide in Group B Streptococcus?
It is used to group GBS into ten serotypes (Ia, Ib, II, III, IV, V, VI, VII, VIII, IX).
p.31
Virulence Factors of Streptococcus pyogenes
What is a notable characteristic of Viridians Streptococci regarding antibiotic resistance?
Multiple resistance is common.
p.15
Virulence Factors of Streptococcus pneumoniae
What is the role of pneumolysin in S. pneumoniae?
It damages pulmonary epithelial cells and cilia.
p.3
Virulence Factors of Streptococcus pyogenes
What are Streptolysins and their role?
They repel phagocytes, disrupt phagocyte membranes, and destroy erythrocyte membranes.
p.9
Post-Streptococcal Complications
When can acute glomerulonephritis occur after an upper respiratory tract infection?
10 days after URTI (sore throat).
p.18
General Characteristics of Streptococcus
Where are viridans streptococci normally found?
Inhabitants of the oral cavity, gastrointestinal tract, and female genital tract.
p.18
Virulence Factors of Streptococcus pyogenes
What can cause viridans streptococci to cause disease?
When they are displaced from their normal sites due to trauma, surgery, or dental extraction.
p.18
Post-Streptococcal Complications
What condition can damaged heart valves lead to in relation to viridans streptococci?
Rheumatic heart disease (RHD).
p.1
General Characteristics of Streptococcus
What are the general microbiologic characteristics of Streptococcus?
Gram positive, non-motile, non-spore forming cocci arranged in pairs/chains, size <2 μm, catalase negative, facultative anaerobes.
p.6
Clinical Features of Streptococcal Infections
What is Erysipelas?
Inflammation of skin and subcutaneous tissues associated with erythema, edema, fever, and lymphadenopathy.
p.7
Clinical Features of Streptococcal Infections
What does cellulitis involve?
Involvement of deeper subcutaneous tissues.
p.17
Clinical Features of Streptococcal Infections
What is the acute onset pneumonia caused by S. pneumoniae called?
Pneumococcal lobar pneumonia.
p.3
Virulence Factors of Streptococcus pyogenes
What do Streptodornases do?
They are nucleases that facilitate liquefaction of pus and have DNase and RNase activity.
p.3
Virulence Factors of Streptococcus pyogenes
What is the function of Hyaluronidase in Streptococcus pyogenes?
It degrades hyaluronic acid in connective tissue.
p.21
Laboratory Diagnosis of Streptococcal Infections
What is the incubation time and temperature for growth on selective media?
18 - 48 hours at 35 - 37 °C.
p.8
Clinical Features of Streptococcal Infections
What is streptococcal toxic shock-like syndrome?
A condition similar to TSST-1 toxin of S. aureus, associated with rash, diarrhea, respiratory and renal failure.
p.9
Post-Streptococcal Complications
What are the clinical manifestations of damage caused by acute glomerulonephritis?
Hematuria, proteinuria, hypertension, edema, renal failure.
p.28
General Characteristics of Streptococcus
What is the result of the mannitol test for S. aureus?
Mannitol positive (yellow).
p.28
Classification of Streptococci
What is a limitation of the Lancefield classification?
Lack of specificity; single Streptococci can be grouped in more than one group.
p.19
Virulence Factors of Streptococcus pyogenes
What is a significant resistance characteristic of Enterococcus?
Multiple resistance to a number of antimicrobial agents, including vancomycin.
p.14
Laboratory Diagnosis of Streptococcal Infections
What does a Gram stain of sputum reveal in the case of Streptococcus pneumoniae?
Gram-positive diplococci.
p.23
Laboratory Diagnosis of Streptococcal Infections
What is the purpose of the catalase test?
To differentiate Staphylococcus from Streptococcus.
p.11
General Characteristics of Streptococcus
What type of hemolytic properties does Group B Streptococcus exhibit?
Beta hemolytic properties.
p.12
Clinical Features of Streptococcal Infections
What other infections can GBS cause?
Bacteremia, endocarditis, skin and soft tissue infections, and osteomyelitis.
p.9
Post-Streptococcal Complications
When can acute glomerulonephritis occur after a skin infection?
3 weeks after skin infection (impetigo).
p.25
Laboratory Diagnosis of Streptococcal Infections
What is the role of the hippurate hydrolysis test?
To identify Group B Streptococcus (S. agalactiae).
p.16
Clinical Features of Streptococcal Infections
What are the clinical features of community-acquired pneumonia caused by S. pneumoniae?
Fever, chills, productive cough (purulent/hemoptysis), and chest pain.
p.19
General Characteristics of Streptococcus
What types of hemolysis can Enterococcus exhibit?
Alpha, gamma, or beta hemolytic.
p.30
Treatment and Prevention of Streptococcal Infections
What does the pneumococcal vaccine contain?
23 serotypes including 1, 2, 3, 4, 5, 6B, 7F, 8, 9N, 9V, 10A, 11A, 12F, 14, 17F, 18C, 19A, 19F, 20, 22F, 23F, and 33F.
p.13
Virulence Factors of Streptococcus pyogenes
What is Streptococcus bovis associated with?
Bacteremia and meningitis, as well as malignancy of the gastrointestinal tract (colon cancer).
p.11
General Characteristics of Streptococcus
Where is Streptococcus agalactiae commonly found as normal flora?
In the female genital tract, upper respiratory tract (URT), and gastrointestinal (GI) tract.
p.23
Laboratory Diagnosis of Streptococcal Infections
What is the catalase result for Streptococcus?
Catalase negative (cat - ve).
p.27
Laboratory Diagnosis of Streptococcal Infections
What is the purpose of using anticapsular antisera in the Quellung test?
To detect the presence of specific capsular types of Streptococcus pneumoniae.
p.25
Laboratory Diagnosis of Streptococcal Infections
What does the CAMP factor test identify?
The presence of Group B Streptococcus (S. agalactiae).
p.26
Laboratory Diagnosis of Streptococcal Infections
What is the incubation environment for the Optochin susceptibility test?
Candle jar or CO2 incubator.
p.5
Virulence Factors of Streptococcus pyogenes
What is the initial step in the pathogenesis of GAS infection?
Adherence to epithelial cells of the upper respiratory tract (URT) and skin.
p.5
Post-Streptococcal Complications
What complications can arise from GAS infections?
Tonsillar abscess, retropharyngeal abscess, cervical lymphadenitis, mastoiditis, otitis media, and sinusitis.
p.19
General Characteristics of Streptococcus
Which Enterococcus species are the most common clinical isolates?
Enterococcus faecalis, Enterococcus faecium, and Enterococcus durans.
p.22
General Characteristics of Streptococcus
What does γ-hemolytic indicate in Streptococci?
No lysis of RBC, with no hemolytic reaction seen around colonies.
p.11
General Characteristics of Streptococcus
What is the primary characteristic of Group B β-hemolytic Streptococci?
Positive CAMP and Hippurate hydrolysis tests.
p.3
Virulence Factors of Streptococcus pyogenes
What is the role of M protein in Streptococcus pyogenes?
It acts as an adhesin and is a colonization factor with over 70 serotypes.
p.17
Clinical Features of Streptococcal Infections
Name two other bacteria that can cause community-acquired pneumonia.
Mycoplasma pneumoniae and Chlamydia pneumoniae.
p.17
Clinical Features of Streptococcal Infections
What type of pneumonia is caused by L. pneumophilia?
Legionnaires' disease (not explicitly mentioned but inferred).
p.31
Clinical Features of Streptococcal Infections
What role does oral hygiene play in relation to Viridians Streptococci?
Oral hygiene is important for prevention.
p.26
Laboratory Diagnosis of Streptococcal Infections
What indicates a positive result in the Optochin susceptibility test?
A zone of inhibition around the disc, indicating S. pneumoniae.
p.4
Virulence Factors of Streptococcus pyogenes
What is C5a peptidase's role in Streptococcus pyogenes?
It inhibits phagocytosis by degrading C5a, a chemotactic factor.
p.19
General Characteristics of Streptococcus
What type of bacteria is Enterococcus?
Gram positive cocci that can be found in single, pair, or chains.
p.5
Epidemiology and Transmission of Group A Streptococcus
Which age group is most affected by GAS infections?
Children aged 5 - 15 years.
p.18
Clinical Features of Streptococcal Infections
What types of infections can viridans streptococci cause?
Wound infections, meningitis, and deep-seated abscesses (liver, brain, teeth, abdomen, pelvis).
p.5
Clinical Features of Streptococcal Infections
What are some differential diagnoses for sore throat related to GAS?
Infectious mononucleosis (IMN), oro-pharyngeal gonorrhea, diphtheria, and adenoviral sore throat.
p.30
Treatment and Prevention of Streptococcal Infections
What is the immunization schedule for the pneumococcal vaccine in children?
Available under EPI for children.
p.6
Clinical Features of Streptococcal Infections
What symptoms are associated with Erysipelas?
Erythema, edema, fever, and lymphadenopathy.
p.13
General Characteristics of Streptococcus
What shape are Streptococcus pneumoniae bacteria?
Gram-positive, lancet-shaped cocci.
p.7
Clinical Features of Streptococcal Infections
What is puerperal fever/sepsis?
Infection of the endometrium introduced through contaminated instruments.
p.12
Post-Streptococcal Complications
What is a potential complication of GBS in postpartum women?
Postpartum infection (Puerperal sepsis).
p.26
Laboratory Diagnosis of Streptococcal Infections
What test is used to differentiate S. pneumoniae from viridians streptococci?
Optochin susceptibility test.
p.21
Laboratory Diagnosis of Streptococcal Infections
What is the purpose of phenyl ethyl alcohol agar?
It is also a selective media.
p.8
Post-Streptococcal Complications
What are some complications of scarlet fever?
Peritonsillar abscess and Ludwig’s angina.
p.21
Laboratory Diagnosis of Streptococcal Infections
What does α-hemolytic reaction indicate?
Partial lysis of RBC, with greenish discoloration around colonies.
p.4
Virulence Factors of Streptococcus pyogenes
What are streptolysins?
They are secreted products involved in the virulence of Streptococcus pyogenes.
p.29
Treatment and Prevention of Streptococcal Infections
What type of vaccines are being tested for GAS?
Specific M-protein vaccines.
p.19
General Characteristics of Streptococcus
How do Enterococcus strains react to catalase?
They are catalase negative.
p.18
Virulence Factors of Streptococcus pyogenes
What serious conditions can viridans streptococci lead to in the bloodstream?
Bacteremia and septicemia.
p.19
General Characteristics of Streptococcus
Where is Enterococcus commonly found in humans?
As normal flora in the gastrointestinal and female genital tracts.
p.1
Classification of Streptococci
What is the Lancefield classification based on?
Group specific cell wall carbohydrate/Lancefield antigen (A - V, 22 groups).
p.30
Epidemiology and Transmission of Group A Streptococcus
Who is at risk for S. pneumoniae infections?
Elderly (65 and older) and children (2 years and older) with certain health conditions.
p.3
Virulence Factors of Streptococcus pyogenes
What distinguishes Streptolysin O from Streptolysin S?
Streptolysin O is oxygen labile and antigenic, while Streptolysin S is oxygen stable.
p.9
Virulence Factors of Streptococcus pyogenes
What strains of Streptococcus pyogenes are associated with nephritogenic effects?
Serotype 1, 3, 4, 12, 25 (URTI) and Serotype 49, 53 (skin infection).
p.25
Laboratory Diagnosis of Streptococcal Infections
Which organism's beta-hemolysin synergistically combines with Group B Streptococcus in the CAMP test?
Staphylococcus aureus (S. aureus).
p.28
Classification of Streptococci
What classification system is used for grouping Streptococci?
Lancefield classification.
p.30
Treatment and Prevention of Streptococcal Infections
What is the antibiotic of choice for S. pneumoniae?
Penicillin, although resistance is increasing rapidly.
p.30
Epidemiology and Transmission of Group A Streptococcus
What health conditions increase the risk for S. pneumoniae infections?
Sickle cell anemia, immunocompromised states, nephrotic syndrome, and chronic pulmonary disease.
p.26
Laboratory Diagnosis of Streptococcal Infections
What does a negative result in the Optochin susceptibility test indicate?
Viridians streptococci or S. bovis.
p.16
Post-Streptococcal Complications
What are some local complications of pneumonia?
Pleural effusion, empyema, lung abscess, and pericarditis.
p.30
Virulence Factors of Streptococcus pyogenes
What does VRE stand for?
Vancomycin-resistant Enterococcus.
p.16
Post-Streptococcal Complications
What systemic complications can arise from pneumococcal infections?
Otitis media, sinusitis, meningitis, endocarditis, and arthritis.
p.30
Virulence Factors of Streptococcus pyogenes
What is a significant issue with Enterococcus strains?
Multiple resistance is common, including high-level resistance to penicillin, vancomycin, and aminoglycosides.
p.30
Treatment and Prevention of Streptococcal Infections
What is the common treatment for Enterococcus endocarditis?
Penicillin combined with aminoglycosides.
p.1
Classification of Streptococci
What is the classification of Streptococcus pneumoniae?
Lancefield Antigen Negative (non-typeable), α/γ.
