Lesson 9 Flashcards
Gram (+) cocci arranged in pair or chains
Streptococcus
spherical to ovoid
Streptococcus
True or False: Generally non motile except few strains of Group B
False- should be Group D
True or False: Generally encapsulated but members of groups A, B, C and D are non-encapsulated
False- should be generally non-encapsulated but groups A, B, C and D are encapsulated
Non-sporeformers
Streptococcus
True or False: Streptococcus is a Facultative aerobes
False- should be Facultative anaerobes
True or False: All species have C carbohydrate in their cell wall except Viridans group and Streptococcus agalactiae
False- should be Viridans Group and Streptococcus pneumoniae
What enrichment media do we use to isolate Streptococcus bacteria?
Blood Agar Plate
Catalase (-)
Streptococcus
Reduce nitrate to nitrite
Streptococcus
Fastidious organism that need to enriched in blood
Streptococcus
True or False: On broth, organism produce translucent to milky, circular, pinpoint colonies with a shiny surface
False: it should be plates not broth
What are the hemolytic patterns on BAP of a Streptococcus?
Beta Hemolytic Group
Alpha Hemolytic Group
Gamma Hemolysis/Non-Hemolytic
Alpha Prime/Wide Zone
Complete lysis ofRBC around the colony. Claer, colorless area around the colony.
Beta Hemolytic Group
What Streptococcus species are member of Beta Hemolytic Group
Streptococcus pyogenes
Streptococcus agalactiae
Green Streptococci. Partial lysis or incomplete hemolysis of RBC around the colony. Forms long chains especially when grow in liquid media.
Alpha Hemolytic Group
What Streptococcus species are members of Alpha Hemolytic Group?
Streptococcus pneumoniae
Viridans Group
No lysis of RBC around the colony. No change observed in the agar around the colony.
Gamma Hemolysis/ Non-Hemolytic
It is also called “The Indifferent Streptococcus”
Gamma Hemolysis/ Non-Hemolytic
What Streptococcus species is the member of Gamma Hemolysis/Non-Hemolytic?
Streptococcus faecalis
Small area of intact RBC surrounded by a wider zone of complete hemolysis.
Alpha Prime/Wide Zone
According to temperature, based on physiological division of Streptococcus:
Pyogenic Group
Lactic Acid Group
Viridans Group
Enterococcus Group
Pus forming organisms. Mostly B-hemolytic and Majority of Lancefield groups.
Pyogenic Group
in what temperature did Streptococcus pyogenes grow?
neither 45°C nor at 10°C
Harmless groups of Streptococcus. Associated in dairy industry, pickles.
Lactic Acid Group
in what temperature did Streptococcus lactis grow?
grows at 10°C but not at 45°C
It is responsible for souring the milk
Streptococcus lactis
in what temperature did Streptococcus mutans and Streptococcus salivarius grow?
Grows at 45°C but not at 10°C
Normal flora of oral cavity and cause of Sub-Acute Bacterial Endocarditis (SBE)
Viridans Group
Can withstand salt high concentration. Normal fecal flora and Currently considered as a new genus.
Enterococcus Group
in what temperature did Enterococcus feacalis grow?
Grows at both 45°C and at 10°C
Used as indicator in water pollution
Enterococcus feacalis
Based on the presence of a serologically active CHO known as C-Polysaccharide group specific CHO Ag
Lancefield Classification
What species has a beta hemolytic pattern?
S. pyogenes
S. agalactiae
S. equisimils
S. equi
What species has an alpha or gamma hemolytic pattern?
S. bovis
S. equines
What species has an alpha, beta or gamma hemolytic pattern?
E. feacalis
E. faecium
E. durans
What species has an alpha hemolytic pattern?
S. pneumoniae
What species has an alpha, alpha-prime or gamma hemolytic pattern?
(Viridans Streptococci) (None-lancefield group)
S. anginosus
S. sanguis
S. mitis
S. mutans
Group A Streptococci.
Predominantly pathogenic to man. Almost always ß-hemolytic
Streptococcus pyogenes
What are the virulence factors of Streptococcus pyogenes?
M Protein
Streptolysin O
Streptolysin S
Streptodornase
Streptokinase
Hyaluronidase
Erythrogenic Toxin/Pyrogenic Toxin
It is resistant to phagocytosis and adherence to mucosal cells and the principal virulence factor.
M Protein
It is Oxygen labile; active only in reduced form or anaerobic conditions. Responsible for sub-surface hemolysis o Highly antigenic; Anti-Streptolysisn O (ASO) indicates recent infection with S. pyogenes. Lyses leukocytes, platelets, and RBC
Streptolysin O
It is Oxygen stable; responsible for hemolysis when incubated aerobically, Surface hemolysis and Non-antigenic.
Streptolysin S
Used to liquefy exudates
Streptodornase
It is responsible for redness and the spreading rash in scarlet fever .
EYTHROGENIC TOXIN/ PYROGENIC TOXIN
What are the three types of toxins in EYTHROGENIC TOXIN/ PYROGENIC TOXIN
A, B, and C
What are the clinical infections of Streptococcus pyogenes?
Pharyngitis and tonsilitis
Pyodermal infections
Streptococcal Toxic shock syndrome
What are the pyodermal infections?
Impetigo
Erysipelas
Cellulitis
Scarlet Fever
“Strep Throat” o Usually in children 5-15 years old; IP: 1-4 days; MOT: droplets and close contact. Manifest as sore throat, malaise, fever, headache, inflamed tonsils and pharynx, swollen and tender cervical lymph nodes.
pharyngitis and tonsilitis
Definitive Dx relies on a throat culture and 1/3 of those with sore throat have a throat culture (+) for
_________?
S. pyogenes
Localized skin disease, small vesicles that progress to weeping lesions.
Impetigo
Impetigo are seen in what age of children?
2-5 years old
Infection of the skin & subcutaneous tissue and it is erythematous lesion.
Erysipelas
Erysipelas is seen in what type of patient?
Elderly Patients
Develops following deeper invasion by Streptococci. Life-threatening. With bacteremia or sepsis present.
Cellulitis
What are the two type of susceptibility test used in Scarlet fever?
Dick’s Test and Schultz-Charlton RXN/ Neutralization RXN/ Blanching Phenomenon
What are the two type of susceptibility test used in Scarlet fever?
Dick’s Test and Schultz-Charlton RXN/ Neutralization RXN/ Blanching Phenomenon
Uses 0.1 mL Dick’s Toxin and 0.1 mL Dick’s Toxoid
DICK’S TEST
what is the result of the dick’s test if: area of erythema/ redness and edema
(+) result
Red rash appear on the upper chest, spreads on the trunk & extremities associated with erythrogenic toxin
Scarlet Fever
Based on the neutralization of erythrogenic toxin when an antitoxin is injected into the skin of patient with a scarlet fever and it is used to diagnose skin rashes whether skin rashes are due to scarlet fever.
SCHULTZ-CHARLTON RXN/
NEUTRALIZATION RXN/ BLANCHING PHENOMENON
if there is
a rashes fade/ blanch, the result would be?
(+) result
Same toxin associated with scarlet fever
STREPTOCOCCAL TOXIC SHOCK SYNDROME
What are the complications associated with S. pyogenes?
Rheumatic fever and Acute glomerulonephritis (AGN)
Complications of S. pyogenes pharyngitis. Fever, inflammation of the heart, joints, blood vessels; most serious result is a progressive damage to the heart valves.
rheumatic fever
Rheumatic fever:
Attacks begin within a ___________ infection; repeated infections may produce further valve damage
month after
May occur after a cutaneous or pharyngeal infection
ACUTE GLOMERULONEPHRITIS (AGN)
True or False: ACUTE GLOMERULONEPHRITIS (AGN) are more common in adults than children.
False- should be more common in children than in adults
What are the laboratory diagnosis of S. pyogenes?
gram stain
culture
biochemical tests
Definitive ID
Immunologic tests to detect past infection with s. pyogenes
What culture media is use in S. pyogenes?
Blood Agar Plate with SXT
What are the biochemical tests of S. pyogenes?
Catalase (-)
Bacitracin (S)
CAMP(-)
Hippurate Hydrolysis (-)
PYR (+)
It is gram (+) cocci in chains, pairs, singly
Gram stain of S. pyogenes, S. agalactiae and Group D Streptococcus
What is the definitive ID for S. pyogenes and S. agalactiae?
Serologic Typing (Lancefield Typing)
What are the Immunologic tests to detect past infection with s. pyogenes?
Anti-Streptolysin O (ASO)
Anti-DNAse
Anti-Streptokinase
Anti-Hyaluronidase
Treatment of choice for S. pyogenes
Penicillin
For those allergy to Penicillin this is the alternative.
Erythromycin
What are the groups for antimicrobial susceptibility testing of S. pyogenes and S. agalactiae?
Group A
Group B
Group C
Group O
What antimicrobial susceptibility testing are belong to Group A of S. pyogenes and S. agalactiae?
Penicillin
Ampicillin
Erythromycin
Clindamycin
What antimicrobial susceptibility testing are belong to Group B of S. pyogenes and S. agalactiae?
Cefepime
Cefotaxime or Ceftriaxone
Vancomycin
What antimicrobial susceptibility testing are belong to Group C of S. pyogenes and S. agalactiae?
Levofloxacin
Ofloxacin
Linezolid
What antimicrobial susceptibility testing are belong to Group O?
Meropenem
Azithromycin
Clarithromycin
Tetracycline
Gatifloxacin
Group B Streptococci. Three (3) Serotypes based on capsular polysaccharides: I, II, and III. Etiologic agent of bovine mastitis in animals. In human, normal flora in the URT, GIT, GUT
STREPTOCOCCUS AGALACTIAE
What are the VIRULENCE FACTORS of S. agalactiae?
Capsule with sialic acid
CAMP Factor
Hyaluronidase
Hemolysin
DNase
Neuraminidase
Protease
What virulence factor of S. agalactiae that prevents phagocytyosis?
Caosule with sialic acid
What are the clinical infection neonates?
Early Onset Infection
Late Onset Infection
Within 3 days after birth
and usually manifests pneumonia or meningitis with bacteremia
Early Onset Infection
Between 1 week and 3 months after birth and Usually meningitis
Late Onset Infection
Women after childbirth or abortion and Elderly with serious underlying disease or
immunodeficiency
ADULTS
Grayish white mucoid colonies surrounded by a small zone of ß-hemolysis on BAP
Culture of S. agalactiae
What are the BIOCHEMICAL TESTS for S. agalactiae?
Catalase (-)
Bacitracin (R)
CAMP (+)
Hippurate Hydrolysis (+)
PYR (-)
What are the treatment for S. agalactiae?
Penicillin and Ampicillin + Aminoglycoside
Previously subdivided into two groups
GROUP D STREPTOCOCCUS
What are the 2 group of GROUP D STREPTOCOCCUS?
ENTEROCOCCAL GROUP and
NON-ENTEROCOCCAL GROUP
It is now placed in a new genus Enterococcus
ENTEROCOCCAL GROUP
Non-enterococcal isolate but is found in the intestinal tract
and Bacteremia has been associated with gastrointestinal tumors
NON-ENTEROCOCCAL GROUP
Remained part of the Group D Streptococci
S. equines and S. bovis
What are the CLINICAL INFECTION of Group D Streptococcus?
Bacterial Endocarditis
UTI
Abscesses
Wound Infections
It is Susceptible to Penicillin
Treatment for Group D Streptococcus
CULTURE for Group D Streptococcus
Alpha or Beta or non-hemolytic on BAP
BIOCHEMICAL TEST
for Group D Streptococcus
Catalase (-)
Bile Esculin (+)
PYR (-)
6.5% NaCl (-)
DEFINITIVE ID for Group D Streptococcus
Serologic Typing for Streptococcus bovis
ANTIMICROBIAL SUSCEPTIBILITY TESTING
GROUP A
Penicillin
Ampicillin
GROUP B
Cefepime
Cefotaxime
Ceftriaxone
Vancomycin
GROUP C
Erythromycin
Chloramphenicol
Clindamycin
Linezolid
GROUP O
Meropenem
Azithromycin
Clarithromycin
Tetracycline
Levofloxacin
Ofloxacin
Gatifloxacin
Previously known as Group D Streptococcus Enterococcus and Found in intestinal tract
ENTEROCOCCUS
Enterococcus Species
Enterococcus faecalis
Enterococcus faecium
Enterococcus durans
Gram (+) cocci in pairs, singly, short chains
GRAM STAIN for Enterococcus
Alpha, Beta, non-hemolytic on BAP
CULTURE for Enterococcus
BIOCHEMICAL TEST
for Enterococcus
Catalase (-)
Bile Esculin (+)
6.5% NaCl (+)
PYR (+)
GROUP A
Antimicrobial for Enterococcus
Penicillin
Ampicillin
GROUP B
Antimicrobial for Enterococcus
Vancomycin
Linezolid
GROUP C
Antimicrobial for Enterococcus
Gentamicin (High level resistace screen only)
Sreptomycin (High level resistace screen only)
GROUP O Antimicrobial for Enterococcus
Erythromycin
Doxycycline
Minocycline
Gatifloxacin
Rifampicin
Chloramphenicol
GROUP U Antimicrobial for Enterococcus
Ciprofloxacin
Levofloxacin
Norfloxacin
Nitrofurantoin
Tetracycline – MIC testing; disk diffusion unreliable
What are the ANTIGENIC STRUCTURES of the STREPTOCOCCUS PNEUMONIAE?
C SUBSTANCE IN THE CELL WALL
CAPSULAR ATIGENS
Similar to C CHO of Lancefield Group
C SUBSTANCE IN THE CELL WALL
With 72 different capsular types. Capsular antigen identified with appropriate antiserum
and Capsule swells in the presence of specific anticapsular serum
CAPSULAR ATIGENS
What are the VIRULENCE FACTORS of S. pneumoniae?
Capsular Polysaccharide
Hemolysin
IgA Protease
Neuraminidase
Hyaluronidase
Pneumolysin O
Purpura Producing Factor
It is Similar to Streptolysin O
Pneumolysin O
Dermal purpura. Thermal hemorrhages in experimental animal
Purpura Producing Factor
What are the CLINICAL INFECTIONS
of S. pneumoniae?
PNEUMONIA
OTITIS MEDIA
MENINGITIS
ENDOCARDITIS
PERITONITIS
BACTEREMIA
Predisposing factors of S. pneumoniae
Alcoholism
Malnutrition
Anesthesia
Viral infections of the RT
Lobar pneumonia (rusty-brown sputum). Caused by types 1, 2, and 3. Usually in elderly and patients with underlying disease. High mortality rate
PNEUMONIA
Most common cause of bacterial meningitis in adults and Also affects all age groups
MENINGITIS
What are the SUBSTANCES RESPONSIBLE FOR SEROLOGICAL REACTION of S. pneumoniae?
SPECIFIC SOLUBLE SUBSTANCE (SSS)
SOMATIC Ag/ O Ag
Polysaccharide capsular substance which determines both the virulence and capsular type
SPECIFIC SOLUBLE SUBSTANCE (SSS)
Present in the cell wall. Binds with C-Reactive CHON (CRP). CRP: increase in patients with acute inflammatory disease
SOMATIC Ag/ O Ag
Gram (+) cocci in pairs, lancet-shaped
Streptococcus lanceolatus
On BAP aerobic: α-hemolytic
On BAP anaerobic: ß-hemolytic due to presence of toxin pneumolysin O
Culture are most often aerobic
Young colonies: circular, glistening and dome-shaped On aging, autolytic changes results in te collapse of the center of colonies appearing as nail-head or checker
Culture of S. pneumoniae
What are the BIOCHEMICAL TEST for S. pneumoniae?
Catalase (-)
Bile Solubility Test (+)
Optochin Sensitivity Test/ TAXO P (S)
Quellung Capsular Swelling (+)
Inulin Fermentation (+)
Quinidine Test (S)
What are the SEROLOGICAL TEST
in S. pneumoniae?
NUEFELD QUELLUNG REACTION
FRANCIS TEST
Capsular Precipitation Rxn/ Capsular Swelling Test o In glass slide, mix a loopful of sputum and antipneumococcal serum + methylene blue
(+) result = capsules appear swollen due to a change in refractive index
NUEFELD QUELLUNG REACTION
Skin test done to determine the presence or absence of Ab against Pneumococcal Ag
FRANCIS TEST
ANIMAL INOCULATION TEST
Mouse Virulence Test
Animal dies within 16-48 hours (+). Pure culture of pneumococci can be grown
Mouse Virulence Test
TREATMENT for S. pneumoniae
Penicillin
Erythromycin
ANTIMICROBIAL SUSCEPTIBILITY TESTING:
GROUP A
Erythromycin
Penicillin
Trimetoprim-Sulfamethoxazole
ANTIMICROBIAL SUSCEPTIBILITY TESTING: GROUP B
Cefepime
Cefotaxime
Ceftriaxone
Meropenem
Vancomycin
Tetracycline
Doxycline
Levofloxacin
Ofloxacin
Clindamycin
ANTIMICROBIAL SUSCEPTIBILITY TESTING: GROUP C
Amoxicillin
Amoxicillin-Clavulanate
Cefuroxime
Chloramphenicol
Rifampicin
Linezolid
ANTIMICROBIAL SUSCEPTIBILITY TESTING: GROUP O
Cefaclor
Ceffpodoxime
Azithromycin
Clarithromycin
Gatifloxacin
- Lack Lancefield Group Ag
- Does not meet the criteria for S. pneumonia
- Identification for _____________ to the species level is difficult
- Oropharyngeal commensal but opportunistic pathogen
VIRIDANS STREPTOCOCCI
CLINICAL INFECTIONS of Viridans Streptococci
Sub-Acute Bacterial Endocarditis (SBE)
Meningitis
Dental Caries
Abscess
Osteomyelitis
Empyema
Gram (+) cocci in pairs
Gram Stain of Viridans Streptococci
α-hemolytic or non-hemolytic on BAP
Culture of Viridans Streptococci
Biochemical Test of Viridans Streptococci
Catalase (-)
Bile Esculin (-)
Optochin (R)
6.5% NaCl (-)
Bile Solubility Test (-)
PYR (-)
TREATMENT of choice for Viridans Streptococci
Penicillin
Other Viridans Streptococci
- Streptococcus anginosus (formerly S. milleri)
- Streptococcus mitis
- Streptococcus oralis
- Streptococcus sanguis
- Streptococcus salivarius
- Streptococcus constellatus
- Streptococcus mutans
- Streptococcus intermedius
Primary animal pathogens
GROUP C STREPTOCOCCI
pathogen in humans
Streptococcus equisimilis
pathogen in horses
Streptococcus equi
Used in thrombolytic therapy in humans
Hydrolyzes thrombus (clot)
Sources of Streptokinase
- Formerly known as Nutritionally Variant Streptococci/ Pyridoxaldependent/ Vitamin B6-dependent/ Thiol-dependent/ Symbiotic Streptococci
- They satellite around the colonies of organism that produces pyridoxal: Staphylocci, E. coli, Klebsiella spp., Enterobacter, and Yeasts
- Gram (+) cocci
- Maybe gram (-), variable and pleomorphic
- Part of the normal flora but can cause endocarditis, otitis media, wound infections
GENUS ABIOTROPHIA
➢ Use of pyridoxal (Vitamin B6 supplemented medium)
➢ Plated with a Staphylococcal streak (cross-streaking)
➢ PYR (+)
➢ Bile Esculin (-)
➢ 6.5% NaCl (-)
Laboratory diagnosis for GENUS ABIOTROPHIA
Other Streptococcus
- Streptococcus acidominimus
- Streptococcus crista
- Streptococcus gordonii
- Streptococcus parasanguis
- Streptococcus sobrinus
- Streptococcus uberis
- Streptococcus vestibularis
- Streptococcus cricetus
- Streptococcus pornicus
- Gram (+) cocci in tetrads
- Aerobic
- Catalase (+)
- Non-motile
- Often yellow orange or red in color
- Easily confured with Staphylococci
- Widespread in soil, water, and mammalian skin
- Non-pathogenic
- Skin colonizers
- Occasionally associated with skin lesions
- More commonly isolated from immunocompromised patients
- Unknown virulence factor; probably of extremely low virulence
- Usually considered contaminants of clinical specimens
- Rarely implicated as cause of infections in humans
- Similar organism: Kocuria spp., Kytococcus spp., and Alloiococcus spp.
MICROCOCCUS
In contrast to Staphylococci:
➢ Not lysed with Lysostaphin
➢ Resistant to furazolidone
➢ Bacitracin (S)
➢ Microdase (+) - Micrococcus luteus
Other Micrococcus
- Micrococcus kristinae
- Micrococcus lylae
- Micrococcus roseus
- Micrococcus sedentarius
- Facklamia
- Dolosigranulum pigrum
- Ignavigranum ruoffiae
- Rothia (formerly Stomatococcus mucilaginosa)
- Gemella
- Pediacoccus
- Tetragenococcus
- Leuconostoc
- Vagococcus
- Aerococcus
- Helcoccus
MISCELLANEOUS GRAM (+) COCCI