Medical Microbes

What is the main difference between gram positive and gram negative bacteria?

Gram positive bacteria have thick peptidoglycan while gram negative bacteria have thin peptidoglycan and an outer membrane

What color do gram positive bacteria appear on Gram stain?

Purple

What color do gram negative bacteria appear on Gram stain?

Pink

What structure is unique to gram positive bacteria?

Teichoic acid

What structure is unique to gram negative bacteria?

Lipopolysaccharide

What bacterial component causes endotoxin shock?

Lipopolysaccharide

What does LPS stand for?

Lipopolysaccharide

Which bacteria are acid-fast positive?

Mycobacterium species

What stain identifies Mycobacterium tuberculosis?

Acid-fast stain

What appearance does Mycobacterium tuberculosis have on acid-fast stain?

Pink beaded rods

What shape are cocci bacteria?

Spherical

What shape are bacilli bacteria?

Rod shaped

What shape are spiral bacteria?

Helical

What arrangement is seen in Streptococcus species?

Chains

What arrangement is seen in Staphylococcus species?

Clusters

What arrangement is seen in Streptococcus pneumoniae?

Diplococci

Which bacteria are helical and associated with gastritis?

Helicobacter pylori

Which bacteria causes chronic gastritis?

Helicobacter pylori

Which organism commonly causes urinary tract infections?

Escherichia coli

What are the characteristics of E. coli on MacConkey agar?

Pink lactose fermenting colonies

Is E. coli oxidase positive or negative?

Oxidase negative

Which bacteria produces blue-green pigment?

Pseudomonas aeruginosa

Which bacteria has a fruity odor?

Pseudomonas aeruginosa

Which bacteria is oxidase positive and gram negative?

Pseudomonas aeruginosa

Which organism commonly infects burn wounds?

Pseudomonas aeruginosa

Which organism causes hot tub folliculitis?

Pseudomonas aeruginosa

Which organism is associated with ventilator-associated pneumonia?

Klebsiella pneumoniae

Which organism is encapsulated and lactose fermenting?

Klebsiella pneumoniae

What is the major virulence factor of Streptococcus pneumoniae?

Capsule

What is the major virulence factor of Klebsiella pneumoniae?

Capsule

What does the bacterial capsule help prevent?

Phagocytosis

Which organism is optochin sensitive?

Streptococcus pneumoniae

Which organism is bile soluble?

Streptococcus pneumoniae

Which organism causes community acquired pneumonia with gram positive diplococci?

Streptococcus pneumoniae

Which organism forms dental plaque?

Streptococcus mutans

Which organism commonly causes pharyngitis and appears in chains?

Streptococcus pyogenes

Which organism is associated with cat bites?

Pasteurella multocida

Which organism is associated with dog bites?

Pasteurella multocida

Which organism causes cellulitis after animal bites?

Pasteurella multocida

Which organism causes tetanus?

Clostridium tetani

What symptom is classically associated with tetanus?

Lockjaw

What type of bacteria is Clostridium tetani?

Gram positive anaerobic spore-forming rod

Which organism causes tuberculosis?

Mycobacterium tuberculosis

What type of granuloma is seen in tuberculosis?

Caseating granuloma

Which organism causes aquarium granuloma?

Mycobacterium marinum

Which parasite causes malaria?

Plasmodium falciparum

What specimen is best for diagnosing urinary tract infections?

Midstream urine

What specimen is preferred for tuberculosis testing?

Early morning sputum

What is the purpose of Gram staining?

To differentiate gram positive and gram negative bacteria

What is the purpose of acid-fast staining?

To identify Mycobacterium species

Which stain is used to visualize capsules?

Capsule stain

Which stain is used to identify bacterial spores?

Endospore stain

What are bacterial flagella used for?

Motility

What are pili used for?

Attachment

What is the bacterial cell wall mainly composed of?

Peptidoglycan

What type of cell are bacteria?

Prokaryotic cells

Do prokaryotic cells have a true nucleus?

No

What genetic material do bacteria contain?

Circular DNA

Where is bacterial DNA located?

Nucleoid

What structure allows bacteria to survive harsh environments?

Endospores

Which genus commonly forms endospores?

Clostridium

Which bacteria are lactose fermenters?

Escherichia coli and Klebsiella pneumoniae

Which bacteria are non-lactose fermenters?

Pseudomonas aeruginosa

Which organism is associated with respiratory infections and thick sputum?

Klebsiella pneumoniae

Which organism is associated with productive cough and capsule formation?

Streptococcus pneumoniae

Which microorganism commonly resides on sebaceous skin?

Cutibacterium acnes

Which fungal form is unicellular?

Yeast

Which fungal form is multicellular?

Mold

What are fungal filaments called?

Hyphae

What is a mass of hyphae called?

Mycelium

How do yeasts commonly reproduce?

Budding

How do fungi reproduce asexually?

Spores

Which fungus causes oral thrush?

Candida albicans

What predisposes patients to oral thrush?

Prolonged antibiotic use

What are the clinical features of oral thrush?

White plaques on the tongue

Which fungus is associated with bird droppings?

Cryptococcus neoformans

Which fungus causes meningitis in immunocompromised patients?

Cryptococcus neoformans

Which fungus causes cryptococcal meningitis?

Cryptococcus neoformans

Which fungus is associated with AIDS pneumonia?

Pneumocystis jirovecii

What disease does Pneumocystis jirovecii cause?

Pneumocystis pneumonia

Which fungus forms septate hyphae?

Aspergillus fumigatus

Which fungus is associated with aspergillosis?

Aspergillus fumigatus

What is the function of the viral capsid?

Protects viral genetic material

What is the function of the viral envelope?

Helps virus enter host cells

What type of nucleic acid do viruses contain?

DNA or RNA

What are viral spike proteins used for?

Attachment to host cells

What is the first step of viral replication?

Attachment

What is the second step of viral replication?

Penetration

What is the third step of viral replication?

Uncoating

What is the fourth step of viral replication?

Replication

What is the fifth step of viral replication?

Assembly

What is the final step of viral replication?

Release

Which virus causes cervical cancer?

Human papillomavirus

Which virus causes plantar warts?

Human papillomavirus

Which virus is associated with squamous cell carcinoma of the cervix?

Human papillomavirus

Which virus is associated with nasopharyngeal carcinoma?

Epstein-Barr virus

Which viral family does Epstein-Barr virus belong to?

Herpesvirus family

Which virus causes infectious mononucleosis?

Epstein-Barr virus

Which virus belongs to the Flavivirus family and causes retro-orbital pain?

Dengue virus

What are the classic symptoms of Dengue fever?

Fever retro-orbital pain and rash