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Gram Positive (purple/blue). Cocci. Rods (bacilli) CLOSTRIDIUM (anaerobe) LISTERIA BACILLUS CORYNEBACTERIUM. Capsule S. PNEUMONIA. Catalse (+) STAPH. Catalse (-) STREP. α. No Capsule VIRIDANS STREP. Coagulase (+) S. AUREUS. Coagulase (-). Group A S. PYOGENES. Hemolysis. β. - PowerPoint PPT Presentation
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Gram Positive (purple/blue)
Cocci Rods (bacilli)CLOSTRIDIUM (anaerobe) LISTERIABACILLUSCORYNEBACTERIUM
Catalse (+)STAPH
Catalse (-)STREP
Coagulase (+)S. AUREUS
Coagulase (-)
Novobiocin (+)S. EPIDERMIDIS
Novobiocin (-)S. PNEUMONIAE
Hemolysis
α
β
γ
CapsuleS. PNEUMONIA
No CapsuleVIRIDANS STREP
Group AS. PYOGENESGroup BS. AGALACTAIE
ENTEROCOCCUSPEPTOSTREPTOCOCCUS
Gram Negative (pink)
Cocci Rods
“Coccoid” RodsH. FLUPASTURELLABRUCELLABORDETELLA PERTUSSISMaltose Fermenter
NEISSERIA MENINGITIDISNon FermenterNEISSERIA GONORRHOEAE
Fast lactose FermenterKLEBSIELLAE. COLIENTEROBACTER
Slow FermenterCITROBACTERSERRATIA
Lactose Nonfermenter
Oxidase NegativeSHIGELLASALMONELLAPROTEUS
Oxidase PositivePSEUDOMONAS
Gram positive Gram negative
2 envelope layers: 1) cytoplasmic membrane 2) thick peptidoglycan layer
3 envelope layers: 1) cytoplasmic membrane 2 )thin peptidoglycan layer
3) phospholipid/LPS Low lipid content High lipid contentNo endotoxin Endotoxin No periplasmic space Periplasmic spaceTeichoic Acid O Specific Side chain
Metabolic Characteristics
• Obligate aerobes
• Facultative anaerobes
• Microaerophilic bacteria
• Obligate Anaerobes
•Love oxygen •Need it to grow•Have all 3 enzymes
•Like oxygen /doesn’t require it•Can use anaerobic fermentation•Catalase and Superoxide Dismutase
•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
Staphylococcus
StreptococcusCocci-catalase test
Streptococci-negative
Staphylococci-positive
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 AureusDirect infection
Impetigo
MRSA
Staphylococcus Aureus diseases due to toxins
Scalded Skin Syndrome
EnterotoxinVery stable
TSST-1
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
• Group A Beta Strep– S. pyogenes
• Strep Throat• Scarlet Fever• Rheumatic Fever• Post Streptococcal Glomerulonephritis• Impetigo
Strawberry tongue
Pharyngitis
Lancefield Antigen Hemolysis on BAP
Chromatographic Immunoassay
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
– Pneumococcus (nickname)– Otitis media, pneumonia, meningitis
Right lower lobe pneumoniaencapsulated
Significant sequalae
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
RespiratoryB. Anthracis
BAP
Genus: Clostridium
• Anaerobic G + Rod• Spore formers• Clostridium
– C. Perfringens– C Tetni– C. Botulinum– C. Difficile
Target hemolysis on BAP ~ two zones due to production of 2 toxins
Myonecrosis/ gas gangrene
Genus: Clostridium• Anaerobic G + Rod• Spore formers• Clostridium
– C. Perfringens– C Tetni– C. Botulinum– C. Difficile
Terminal SporeTennis Racket
Neurotoxin binds to presynaptic terminals in prevents transmission of inhibitory neurotransmitters
DTP and DTaP
Genus: Clostridium
• Anaerobic G + Rod• Spore formers• Clostridium
– C. Perfringens– C Tetni– C. Botulinum– C. Difficile
Infantile Botulism caused by spore ingestion with endogenous toxin production
Spores
Toxin ingestion (usual)
Genus: Clostridium• Anaerobic G + Rod• 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)
Endoscopic view of Psuedomembranous colitis
Gram Positive Nonspore Forming Rods
• Nonfilamentous– Corynebacterium– Listeria– [Mycobacterium-kind of]
Genus: Corynebacterium• Gram Positive Nonspore Forming Rods• Immobile• Nonencapsulated• Nonfilamentous• Corynebacterium
– C. Diphtheriae
Pallisades/ Chinese Letter ArrangementsBarred appearance (metachromatic granules)
Pseudomembrane of throat and/or nasal cavity
DTP and DTaP
Genus: Listeria
• Gram Positive Nonspore Forming Coccobacilus• Tumbling motility at 25 degrees Celsius• Nonfilamentous
– Listeria• L. Monocytogenes
Beta hemolysis
Raw milk, soft cheeses, ice cream, raw vegetables, raw or cooked poultry, raw meat, raw or smoked fish
Transplacental and birth canal transmission
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 hoursAcid 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
– A. Israelii Lumpy Jaw
Actinomycoses infections are polymicrobial
Genus: Nocardia• Gram Positive Filamentous • Branching• Weakly acid fast• Strict aerobe• Catalase positive• Nonspore Forming Rods
– Nocardia
Primary source is soilColonies smell like wet dirt
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
Nonblanching petechial rash
Kidney bean shape
Not B
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 TestsOphthalmia Neonatorum
$$$
• Gram Negative Cocci • Aerobic• Moraxella
– Branhemella Catorrhalis• Otitis media, sinusitis
sinusitis
Otitis media
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
– Nontreponemal tests– Treponemal tests
Electron Micrograph
Secondary stage
Gram Negative Spirochetes
• Microaerophilic• Geimsa or Wright stain• Borrelia
– B. Burgdorfi
Erythema migrans
western black-legged tick (Ixodes)
Gram Negative Spirochete• Aerobic• Motile• G –cell envelope• Animal reservoirs• Flexible spirochete• Not seen on gram stain• Dark field microscopy• Leptospira
– L. Interrigans
Petichial rash
Fine spirals with hooked ends
Water transmission
Many Many Gram Negative Bacilli• Respiratory
– Heamophilus – Bordetella– Legionella– Gardnerella
• Zoonotics– Yersinia– Franicisella– Brucella– Pasteurella– Bartonella
• 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• non–spore-forming• Fastidious-X &V factor• facultative anaerobe• Heamophilus
– H. Influenzae• HIb• Epiglottitis, otitis media, meningitis, pneumonia
– H. Ducryi
Otitis media
Satelliting around Staph.
EpiglottitisInsp. Stridor
conjugated
Respiratory Gram Negative Bacilli
• small pleomorphic, gram-negative 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
– B. Pertussis– Whooping cough
Bordet-Gengou medium
ELISA or PCR assays
DTP & DTaP Paroxysmal cough with an inspiratory whoop
Respiratory Gram Negative Bacilli
• Nicotinamide required for (slow) growth• Bordetella
– B. Pertussis– Whooping cough
Virulence factors•Pili and surface protein for adhesion•Pertussis toxin•Enzyme that disrupts immune response•Peptidoglycan injury to ciliated trachea cells
Bordet-Gengou medium
ELISA or PCR assays
DTP & DTaP
Respiratory Gram Negative Bacilli
• Poorly staining• Facultative Intracellular parasite• Compromised host• Aerobic• Legionella
– L. Pneumophila• Legionnaires' disease
– Pneumonia
Urinary antigenSputum culture
Paired serum sample
NONRespiratory Gram Negative Bacilli
• Presumptive Identification– Clue Cells– KOH
• Does not require X & V factors• Gardnerella
– G. Vaginalis• Bacterial Vaginosis (BV), preterm labor
cervicitis
Whiff TestClue cells
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
Bubonic Plague
Zoonotic Gram Negative Bacilli• Nonmotile• G- rod• Yersinia
• Y. Pestis
Pneumonic Plague
bubo
•G- bacillus•Aerobic•Low infecting dose•Vector->tick or deer fly•Special media•Immunoflourescence•Serum Serology (>1:40)•Franicisella
• F. Tularensis• Pneumonia• Glandular
Zoonotic Gram Negative Bacilliulceroglandular
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• PCN susceptible• Bacteriophage encoded toxin• Pasteurella
– P. Multocida• Cellulitis associated with
animal bites
Well demarcated cellulitis
Grows on BAPBipolar staining
Zoonotic Gram Negative Bacilli• fastidious • pleomorphic • aerobic • gram-negative bacillus • Bartonella
– B. Henselae• Cat Scratch Fever
– B. Quintana• Trench fever• Urban Trench Fever
Cat scratch fever
Pediculus humanus
Paired sera
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
UTI/ Pyelonephritis
Motile strains with peritrichous flagella
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 when
motile• Produce gas upon sugar
fermentation Salmonella– S. Typhi
• Typhoid Fever– S. Enteritidis
• Gastroenteritis
Carrier states
Eggs & Enteritidis
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
• 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
Weird Bugs
Peticheal rash
• Obligate intercellular gram negative coccobacilli
• Coxiella Brunetti
Weird Bugs
• Ehrlichia– E. chaffeensis– E. ewingii
Weird Bugs
Amblyomma americanumNymph left ; adult right
Ehrlichea in white tail deer fawn
Distribution of Amblyomma americanum [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-
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