Gram Positive (purple/blue)
Cocci
Catalse (+)
STAPH
Coagulase (+)
S. AUREUS
Catalse (-)
STREP
Rods (bacilli)
CLOSTRIDIUM (anaerobe)
LISTERIA
BACILLUS
CORYNEBACTERIUM
α
Coagulase (-)
Hemolysis
Novobiocin (+)
S. EPIDERMIDIS
Capsule
S. PNEUMONIA
No Capsule
VIRIDANS STREP
β
Group A
S. PYOGENES
Group B
S. AGALACTAIE
γ
ENTEROCOCCUS
PEPTOSTREPTOCOCCUS
Novobiocin (-)
S. PNEUMONIAE
Gram Negative (pink)
Cocci
Maltose Fermenter
Non Fermenter
NEISSERIA MENINGITIDIS NEISSERIA GONORRHOEAE
Rods
“Coccoid” Rods
H. FLU
PASTURELLA
BRUCELLA
BORDETELLA PERTUSSIS
Fast lactose Fermenter
KLEBSIELLA
E. COLI
ENTEROBACTER
Slow Fermenter
CITROBACTER
SERRATIA
Oxidase Negative
SHIGELLA
SALMONELLA
PROTEUS
Lactose Nonfermenter
Oxidase Positive
PSEUDOMONAS
Gram positive
Gram negative
2 envelope layers:
3 envelope layers:
1) cytoplasmic membrane
2) thick peptidoglycan layer
1) cytoplasmic membrane
2 )thin peptidoglycan layer
3) phospholipid/LPS
Low lipid content
No endotoxin
No periplasmic space
High lipid content
Endotoxin
Periplasmic space
Teichoic Acid
O Specific Side chain
Metabolic Characteristics
• Obligate aerobes
•Love oxygen
•Need it to grow
•Have all 3 enzymes
•Like oxygen /doesn’t require it
• Facultative anaerobes
•Can use anaerobic fermentation
•Catalase and Superoxide Dismutase
• Microaerophilic bacteria
• Obligate Anaerobes
•Like small amounts of oxygen
•Aerotolerent anaerobes
•Superoxide Dismutase
•Don’t like oxygen
•No enzymes to
counter act
Gram Positive Pathogens
• Cocci
– Staphylococci
– Streptococci
• Rods (bacilli)
– Spore formers
• Bacillus
• Clostridium
– Nonspore formers
• Nonfilamentous
– Corynebacterium
– Listeria
– [Mycobacterium-kind of]
• Filamentous
– Actinomyces
– Nocardia
Gram Positive Pathogens
Cocci-catalase test
Streptococcus
Streptococci-negative
Staphylococci-positive
Staphylococcus
Genus: Staphylococci
• Gram Positive Cocci in groups and clusters
• Catalase positive
• Coagulase Test for differentiation
– S. Aureus-positive
– S. Epidermidis-negative
– S. Saprophyticus-negative
Virulence factors
•Surface protein A binds to Fc portion
of IgG (prevents opsonization)
•Enterotoxin and TSST-1 toxins
Staphylococcus Aureus
Direct infection
Impetigo
MRSA
Staphylococcus Aureus
diseases due to toxins
TSST-1
Enterotoxin
Very stable
Scalded Skin Syndrome
Genus: Staphylococcus
Staph Epidermidis
Genus: Streptococcus
Catalase Negative Gram Positive Cocci in pairs and chains
Genus: Streptococcus
•
•
•
•
S. pyogenes
S. agalactiae
S. pneumoniae
Enterococcus
Genus: Streptococcus
• Lancefield Antigens
– Lancefield antigens denote cell wall carbohydrates
– The presence of Lancefield antigens defines the
pyogenic streptococci
– Groups A through T
• A,B, C and D are most important
– Some Streptococcus are not assigned (they do not
possess) Lancefield antigens
Genus: Streptococcus
• Hemolysis on BAP
• The hemolysis is defined as alpha, beta and gamma
No
Complete
Partial
Genus: Streptococcus
• Strep Pyogenes
– Group A Beta Strep
– Strep throat, scarlet fever, rheumatic fever, acute
glomerulonephritis, impetigo
• Strep Agalactactiae
– Group B Beta Strep
– Perinatal sepsis, meningitis and/or pneumonia
• Strep Pneumoniae
– Pneumococcus
– Optichin Sensitive
– Otitis media, pneumonia, meningitis
• Enterococcus
– Group D
– UTI
Genus: Streptococcus
Lancefield Antigen
Hemolysis on BAP
Strawberry tongue
• Group A Beta Strep
– S. pyogenes
•
•
•
•
•
Strep Throat
Scarlet Fever
Rheumatic Fever
Post Streptococcal Glomerulonephritis
Impetigo
Chromatographic
Immunoassay
Pharyngitis
Genus: Streptococcus
• Strep Agalactactiae
– Group B Beta Strep
– Perinatal sepsis, meningitis and/or
pneumonia
• Early Sepsis within one week of birth
• Late Sepsis from 7days to 3 months of
birth
Genus: Streptococcus
•
•
•
•
Alpha hemolysis
Optichin Sensitive
Gram positive Lancet Shaped Diplococci
Strep Pneumoniae
Significant sequalae
– Pneumococcus (nickname)
– Otitis media, pneumonia, meningitis
Right lower lobe pneumonia
encapsulated
Genus: Streptococcus
• Enterococcus
– Group D
– Virulence Factors
•
•
•
•
•
Abx resistant due to PBP
Acquired Resistance
Enzymes
Adherence factors
Biofilm formation
– UTI, catheter related infections
Gram Positive Spore Forming Rods
• Bacillus (Fac. Anaerobe)
• Clostridium (Strict Anaerobe)
Genus: Bacillus
• Fac. Anaerobe
• G + Spore Forming Rod
• Bacillus
– B. Anthracis
• Cutaneous
• Respiratory
• Intestinal
Respiratory
B. Anthracis
BAP
Genus: Clostridium
• Anaerobic G + Rod
• Spore formers
• Clostridium
– C. Perfringens
– C Tetni
– C. Botulinum
– C. Difficile
Myonecrosis/ gas gangrene
Target hemolysis on BAP ~ two
zones due to production of 2
toxins
Genus: Clostridium
• Anaerobic G + Rod
• Spore formers
• Clostridium
– C. Perfringens
– C Tetni
– C. Botulinum
– C. Difficile
Neurotoxin binds to presynaptic
terminals in prevents transmission
of inhibitory neurotransmitters
Terminal Spore
DTP and DTaP
Tennis Racket
Genus: Clostridium
• Anaerobic G + Rod
• Spore formers
• Clostridium
Toxin ingestion
(usual)
– C. Perfringens
– C Tetni
– C. Botulinum
– C. Difficile
Infantile Botulism caused by
spore ingestion with
endogenous toxin production
Spores
Genus: Clostridium
• Anaerobic G + Rod Endoscopic view of Psuedomembranous colitis
• Spore formers
• Clostridium
–
–
–
–
C. Perfringens
C Tetni
C. Botulinum
C. Difficile
Plain film of abdomen showing bowel wall thickening, loss of haustral
markings (thin arrow) and dilation of the ascending and transverse
colon (thick arrow)
Gram Positive Nonspore Forming Rods
• Nonfilamentous
– Corynebacterium
– Listeria
– [Mycobacterium-kind of]
Genus: Corynebacterium
•
•
•
•
•
Gram Positive Nonspore Forming Rods
Immobile
Nonencapsulated
Nonfilamentous
Corynebacterium
– C. Diphtheriae
Pseudomembrane of throat
and/or nasal cavity
DTP and DTaP
Pallisades/ Chinese Letter Arrangements
Barred appearance (metachromatic granules)
Genus: Listeria
• Gram Positive Nonspore Forming Coccobacilus
• Tumbling motility at 25 degrees Celsius
• Nonfilamentous
– Listeria
• L. Monocytogenes
Transplacental and birth canal
transmission
Raw milk, soft cheeses, ice
cream, raw vegetables, raw or
cooked poultry, raw meat, raw
or smoked fish
Beta hemolysis
Genus: Mycobacterium
•
•
•
•
•
Gram Positive Nonfilamentous Nonspore Forming Rods
Strict aerobe
Very slow growing
Weakly gram positive
Acid Fast-waxy cell wall-mycolic acid
– [Mycobacterium -kind of]
• M. Tuberculosis
• M.Leprae
Divides every 15 to 20 hours
Acid fast gram positive bacteria
PPD
Genus: Mycobacterium
•
•
•
•
•
Gram Positive Nonfilamentous Nonspore Forming Rods
Waxy coating->acid fast
Aerobic/ nonmotile
Can not grow in artificial culture
[Mycobacterium -kind of]
–
M. Tuberculosis
–
M.Leprae
• Leprosy
• Hanson’s Disease
Nine banded Armadillo
Incubation is 2-20 years
• Gram Positive Filamentous Nonspore
Forming Rods
• Aerobic to Fac. Anaerobe
• Opportunistic
• Actinomyces
– A. Israelii
• Nocardia
Genus: Actinomyces
• Gram Positive Filamentous Nonspore
Forming Rods
• Aerobic to Fac. Anaerobe
• Non acid fast
• Opportunisitic
• Actinomyces
Lumpy Jaw
– A. Israelii
Actinomycoses infections
are polymicrobial
Primary source is soil
Genus: Nocardia
•
•
•
•
•
•
Colonies smell like wet dirt
Gram Positive Filamentous
Branching
Weakly acid fast
Strict aerobe
Catalase positive
Nonspore Forming Rods
– Nocardia
Low virulence opportunistic infection
Now on to Gram Negatives
Gram Negative Cocci
• Neisseria
– N. Meningitidis
– N. Gonnorhea
• Moraxella
– Branhemella Cattorhalis
• Gram Negative Cocci
• Kidney bean shape
• Ferments maltose and glucose like
meningitis
• Oxidase and catalase positive
• Endotoxin production
• Neisseria
– N. Meningitidis
• Meningiococcus (nickname)
• Meningitis, septic shock
– N. Gonnorhea
Kidney bean shape
Not B
Nonblanching petechial rash
Direct or from cultured specimen
• Gram Negative Cocci
• Kidney bean shaped
• Neisseria
– N. Gonorrhea
• Gonorrhea
• Ophthalmia Neonatorum
Culture is the gold standard
$$$
Nucleic Acid Amplification Tests
Ophthalmia Neonatorum
Otitis media
• Gram Negative Cocci
• Aerobic
• Moraxella
– Branhemella Catorrhalis
• Otitis media, sinusitis
sinusitis
Gram Negative Spirochetes
• Treponema
– T. Pallidum
• Borrelia
– B. Burgdorfi
– B. Recurrentis
• Leptospira
Gram Negative Spirochetes
•
•
•
•
Too small for gram stain
Can not be cultured from clinical specimen
Dark field microscopy of clinical sample
Treponema
– T. Pallidum
• Syphillus-acquired and congenital
Electron Micrograph
– Nontreponemal tests
– Treponemal tests
Secondary stage
Gram Negative Spirochetes
western black-legged tick (Ixodes)
• Microaerophilic
• Geimsa or Wright stain
• Borrelia
– B. Burgdorfi
Erythema migrans
Gram Negative Spirochete
•
•
•
•
•
•
•
•
Aerobic
Motile
G –cell envelope
Animal reservoirs
Flexible spirochete
Not seen on gram stain
Dark field microscopy
Leptospira
– L. Interrigans
Fine spirals with hooked ends
Water transmission
Petichial rash
Many Many Gram Negative Bacilli
• Respiratory
–
–
–
–
Heamophilus
Bordetella
Legionella
Gardnerella
–
–
–
–
–
Yersinia
Franicisella
Brucella
Pasteurella
Bartonella
• Zoonotics
• Enterics
– Many many
Respiratory Gram Negative Bacilli
•
•
•
•
•
•
small pleomorphic, gram-negative coccobacillus.
Nonmotile
non–spore-forming
fastidious
facultative anaerobe
Heamophilus
– H. Influenzae
– H. Ducryi
Respiratory Gram Negative Bacilli
•
•
•
•
•
•
Small pleomorphic, gram-negative coccobacillus.
Nonmotile
Otitis media
non–spore-forming
Fastidious-X &V factor
facultative anaerobe
Heamophilus
Epiglottitis
– H. Influenzae
Insp. Stridor
• HIb
• Epiglottitis, otitis media, meningitis, pneumonia
– H. Ducryi
conjugated
Satelliting around Staph.
Respiratory Gram Negative Bacilli
• small pleomorphic, gramnegative coccobacillus.
• Nonmotile
• non–spore-forming
• Fastidious-X &V factor
– Dies quickly outside of
body
• facultative anaerobe
Heamophilus
– H. Ducryi
• “soft chancre”
• Culture is difficult
• chancroid
Painful genital ulcer
Respiratory Gram Negative Bacilli
• Small aerobic G- Coccobacilllus
• Singly and in pairs
• Nicotinamide required for (slow)
growth
• Bordetella
Bordet-Gengou
– B. Pertussis
medium
– Whooping cough
DTP & DTaP
ELISA or PCR assays
Paroxysmal cough with an inspiratory whoop
Respiratory Gram Negative Bacilli
• Nicotinamide required for (slow) growth
• Bordetella
– B. Pertussis
– Whooping cough
DTP & DTaP
ELISA or PCR assays
Virulence factors
•Pili and surface protein for adhesion
•Pertussis toxin
•Enzyme that disrupts immune response
•Peptidoglycan injury to ciliated trachea cells
Bordet-Gengou
medium
Respiratory Gram Negative Bacilli
•
•
•
•
•
Poorly staining
Facultative Intracellular parasite
Compromised host
Aerobic
Legionella
– L. Pneumophila
• Legionnaires' disease
– Pneumonia
Paired serum sample
Urinary antigen
Sputum culture
NONRespiratory Gram Negative Bacilli
• Presumptive Identification
– Clue Cells
– KOH
• Does not require X & V factors
• Gardnerella
– G. Vaginalis
• Bacterial Vaginosis (BV), preterm
labor
Whiff Test
Clue cells
cervicitis
Zoonotic Gram Negative Bacilli
• Yersinia
•
Y. Pestis
– Franicisella
• F. Tulerensis
– Brucella
•
•
•
•
B. Suis
B. Meltensis
B. Abortus
B. Canis
– Pasteurella
• P. Multicida
– Bartonella
• B. Henselae
• B. Quintana
Zoonotic Gram Negative Bacilli
• Nonmotile
• G- rod
• Yersinia
•
Bubonic Plague
bubo
Y. Pestis
Pneumonic Plague
Zoonotic Gram Negative Bacilli
•G- bacillus
•Aerobic
•Low infecting dose
•Vector->tick or deer fly
•Special media
•Immunoflourescence
•Serum Serology (>1:40)
•Franicisella
•F. Tularensis
•Pneumonia
•Glandular
ulceroglandular
pneumonia
Zoonotic Gram Negative Bacilli
•
•
•
•
•
Nonmotile
Non-acid fast
Nonsporeforming
Small G- coccobacillus
Catalase, oxidase and urease
positive
• Brucella
– Brucellosis
Blood
culture
Recurrent flu-like symptoms with granulomas
Zoonotic Gram Negative Bacilli
•
•
•
•
•
•
•
•
Small G- coccobacillus
Nonspore forming
Oxidase positive
Ferments CHO
Nonmotile
Grows on BAP
PCN susceptible
Bacteriophage encoded toxin
Pasteurella
– P. Multocida
• Cellulitis associated with
animal bites
Bipolar staining
Well demarcated cellulitis
Zoonotic Gram Negative Bacilli
•
•
•
•
•
fastidious
pleomorphic
aerobic
gram-negative bacillus
Bartonella
– B. Henselae
• Cat Scratch Fever
– B. Quintana
• Trench fever
• Urban Trench
Fever
Paired sera
Pediculus humanus
Cat scratch fever
Family: Enterobacteriacea
•
•
•
•
•
•
•
•
Escherichia Coli
Shigella
Salmonella
Yersinia
Klebsiella
Proteus
Enterobacter
Serratia
•Enterics live in the gut-> are members of the
family of Enterobacteriacea
•O antigen is lipopolysaccaride
•K antigen is polysaccharide capsule
•H-flagellar antigen
Enterics
•
•
•
•
•
Facultative Anaerobe
Large G- Rods
Nonsporeformers
Normal Flora
Escherichia Coli
– E. Coli (nickname)
– E. Coli 0157:H7 or
0157
– UTI, Sepsis, Enteric
E.Coli, Respiratory
illness, multiple
opportunistic
infections
Motile strains with peritrichous flagella
UTI/ Pyelonephritis
Enterics
• Facultative
Anaerobe
• Large G- Rods
• Nonsporeformers
• Relatively inert
• Shigella
– S. Sonnei
– S. Flexneri
– S. Dysenteriae
• Shigillosis
The O antigens (LPS) define the four species of Shigella
Enterics
•
•
•
•
•
•
G- Rod
Nonsporulating,
Facultative anaerobe
Ferment glucose
Reduce nitrate
Peritrichous flagella
Eggs & Enteritidis
when motile
• Produce gas upon sugar
fermentation Salmonella
– S. Typhi
• Typhoid Fever
– S. Enteritidis
• Gastroenteritis
Carrier states
Enterics
• Nonmotile
• G - rods
• Prominent
polysaccharide
capsule
• Multi Drug Resistant
• Recently important in
nosocomial
infections
• Normal flora
• Klebsiella
– K. Pneumoniae
• Pneumonia in
debilitated,
UTI, etc etc.
Encapsulated/ multi drug resistant
Enterics
•
•
•
•
•
Gram Negative Rod
Normal Flora
Hydrolyzes Urea (struvite
stone formation)
Proteus
– P. Mirabilis
Opportunistic infections
including UTI
Highly motile
Enterics
• G-Rod
• Multi drug
resistance
• Enterobacter
– E. Aerogenes
– E. Cloacae
• UTI,Endocarditis,
opportunistic
infection
Enterics
• G-rods
• Opportunistic
infection Serratia
– S. Marcescens
Other Gram Negative Rods
•
•
•
•
Vibrio
Helicobacter
Pseudomonas
Bacteroides
Other Gram Negative Rods
• Vibrio
– V. Cholerae
Other Gram Negative Rods
• Helicobacter
– H. Pylori
Other Gram Negative Rods
• Helicobacter
– Campylobacter
Jejuni
Other Gram Negative Rods
• Pseudomonas
– Ps. Aeruginosa
Other Gram Negative Rods
• Bacteroides
– B. Fragilis
Weird Bugs
•
•
•
•
Chlamydia
Rickettsia
Coxiella
Ehrlichia
Weird Bugs
• Chlamydia
– C. Trachomatis
Weird Bugs
• Obligate intercellular
gram negative coccobacilli
• Vector
– Dermacentor variabilis (dog
tick) East US
– Dermacentor andersoni
Rocky Mountain region and
Canada
• Rickettsia
– R. Ricketseii
Peticheal rash
Weird Bugs
• Obligate
intercellular gram
negative
coccobacilli
• Coxiella Brunetti
Weird Bugs
• Ehrlichia
– E. chaffeensis
– E. ewingii
Ehrlichea in white tail deer fawn
Distribution of Amblyomma americanum
Amblyomma americanum
Nymph left ; adult right
[Lone Star Tick]
Genus: Mycoplasma
• Pleomorphic
• No cell wall
• Mycoplasma
– M. Pneumoniae
• Atypical pneumonia
The Inevitable Exceptions
• Mycobacteria
– Weakly gram positive
– Better seen with acid fast stain
• Spirochetes
– Too small for light microscopy
– Need Dark field microscopy
• Mycoplasma
– No cell wall
– Neither G+ or G-