MedMicro Flash Cards for all bacteria as of 11JUN2025

Staphlyoccosus aureus

Gram positive Cocci that is catalase positive. Coagulase positive Creates a golden yellow pigment and is hemolysis beta.Ferments mannitol.

Virulence factors Protein A (binds to Fc-IcG), Caues toxic shock syndrome (TSST-1), exfoliative toxin and enterotoxin (heat stable, rapid food poisoning, PVL (leukocidin, necrosis)

Streptococcus pneumoniae

Gram positive lancet-shaped diploocci. Encapsulated. Catalase negative Hemolytic alpha, optochin sensitive, bile solutble sensitive Virulence factor IgA protease.

Causes meningitdis, otitis media, pneumonia, sinusitis.

No virulence with capsule

*associated with rusty sputum, patients with hyposplenia or asplenia.

Viridians Streptococci (e.g.S.mutans,S. Sanguis)

Gram positive Cocci

Catalse negative, Alpha hemolytic/optochin resistant and bile insoluble. Normal flora of oropharynx

Creates biofilm with dental plaque, and infective endocarditis

Streptococcus pygoenes (group A)

Gram postive Cocci

Catalase negative, hemolytic beta/bacitracin sensitive

Virulence factors M (protein prevents phagocytosis, autoimmune mimicry and Erythrogenic toxin

Streptococcus algalactiae (group b)

Gram positive Cocci

Encapsulated catalase negative and hemolytic beta. Bacitracin resistant

Entreococcus

Gram positive Cocci

Catalase negative and does Hemolysis game (none). Grows in 6.5% NacCl and bile

Clostridium Botulinum

Gram positive bacillus Anaerobic spore forming with Botulinum toxin (lysogenic phage)

Pseudomonas Aeruginosa

Gram negative rod. Encapsualted aerobic, catalase positive. creates blue green pigment (pyocyanin, pyoverdin). Creates biofilm in cystic fibrosis lungs. ventilator associated pneumonia and Contact lens keratitis

Haemophilus influenza (type b and non tapeable)

Gram negative pleomorphic. Encapsulated type b. Culture: Chocolate agar (requires factors V and X. Vaccines Hib conjugate. Non typeable Otis media. Virulence factor: Excretes IgA protease (cleaves IgA)

Neisseria meningitidis

Gram negative Diplococci, intracellular facultative. Encapsulated. Culture: Thayer Martin agar (Vancomycin inhibits gram positive, Trimethoprim and Colistin inhibit gram negative bacteria, fungi with Nystatin)

Vaccines: Meningococcal conjugate

Virulence factor: igA protease

Escherichia Coli

Gram positive negative bacillus (enterics)

Encapsulated facultative anaerobe and catalase positive. Culture EMB agar (MacConkey agar as its enteric)
Most common cause of uncompleted UTI in young females.

Mycobacterium Tuberculosis

Stain: Acid fast (ziehl neellsen) rod

Culture Lowenstein Jensen medium

Aerobic (predilection forn apices of the lung after immunocompromise or TNF alpha inhibitor use

intracellular facultative

legionella

intracellular facultative bacteria. Silver stain. Culture Charcoal yeast extract medium that requires cysteine and iron

Listeria monoctyogenes

Gram positive intracellular facultative catalase

Nocardia

Acid fast Uses Ziehl-Neelson Stain

Aerobic, urease positive and catalase positive

Proteus

Gram negative urease positive which is particularly known for struvtie stone formation

Klebsiella

Gram negative enteric (facultative anaerobic ) and urease positive

Cryptococcus neoformans

Stain india ink and urease positive

Helicobacter pylori

Gram negative entericis catalase positive and urease positive. Uses silver stain

klebsiella pneumoniae

Enteric (gram stain negative rod) Facultative anaerobic encapsulated

Corynebacterium Diphtheriae

Positive rod (Bacillus) Culture Tellurite or loffler media, virulence factor : Diphtheria toxin (lysogenic phage)

Bordetella pertussis

Gram negative bacteria, uses Bordet Gengous (potato) Regan-lowe (Charcoal, blood, antibiotic. Aerobic and catalase positive

Serretia maracescenes

Gram negative , red pigment and catalase positive

Candida

fungus, catalase positive, saboruad agar (starts with C)

Aspergillus

Fungus Catalse positive saboraud agar

Francisella

Gram negative (zoonotic) and facultative intracellular with F

Yersinia pestis

Gram negative entrics,iintracellular facultative

Actinomyces israellii

Gram positive anaerobic yellow suflur granules

Coccidioides

Fungus and silver stain

Trypanosomes

Giemsa stain that starts with T

Plasmodium

Giemsa thats starts with P (

parasite)

Cryptosproduium

Protozoa that uses ziehl-neelsen

Borrelia

Giemsa stain (B)

Naegleria Fowleri

Protozoa

Chlamydia

Obligate intracellular giemsa stain

Rickettsia

Obligate intracellular giemsa stain

Coxiella

Intracellular obligate starts with C

Treponema

too Thin to be stained

Leptospira

too thin to be stained starts with L

mycoplasma pneumonia

no cell wall, can’t be stained. Uses Eaton agar that requires cholesterol

Ureplasma

No cell wall and is urease positive

bacteroides

Gram negative enteric and anaerobic

Fusobacterium

gram negative and anaerobic

anaplasma

intracellular obligate with A

Ehrilichia

obligate intracellular starts with E

Bartonella

zootopic gram stain negative intracellular obligate (with b)

Tropheryma whipplei

Stain (periodic acid-schiff). Causes Whipple dieases

Staphlyocus Epidermis

Gram positive Cocci. Catalase positive, and Coagulase negative and novobiocin sensitive. Urease positive Creates biofilm in catheters. Does ferment mannitol
Normal in skin flora: Contaminates blood cultures.

Staphlyoccus saphrophytisus

Gram postiive cocci that is catalase positive and urease positive. Coagulase negative Its novobocin resistant. Normal flora of female genital tract and perineum.

2nd most common cause of uncomplicated UTI in young females

Bacillus anthracis

Gram postiive spore forming. Cotains dipcolinic acid, highly causes anthrax

Bacillus cerus

Spore forming gram positive -associated with food poisoning

Clostridium difficle

gram positive spore forming anaerobic -associated with pseudomembranous colitis

Clostridium perfringens

Gram posttive spore forming anaerobic that causes gas gangrene

Clostridium tenani

gram postive anaerboic spore forming causing tetatanous

Salmonella

gram negative rod (enteric). Facultative anaerobe and intracellular and encapsulated

Brucella

Gram negative zootopic Facultative intracellular