Microbiology: Key Definitions and Bacteria Characteristics

These flashcards cover key definitions and important concepts connected to various pathogenic bacteria and associated diseases.

Non-pathogenic

Does not cause disease.

Pathogenic

Capable of causing disease.

Opportunistic pathogen

Usually harmless, but can cause disease when conditions allow.

Nitrogen fixation

Process where bacteria convert nitrogen gas (N₂) into ammonia (NH₃) usable by plants.

Porins

Protein channels in the outer membrane of Gram-negative bacteria that allow small molecules to enter.

Pertussis

Bacterial respiratory infection causing severe coughing fits, caused by Bordetella pertussis.

DTaP & Tdap vaccines

Vaccines that protect against diphtheria, tetanus, and pertussis.

Adhesins

Molecules that help bacteria attach to host cells.

Meningitis

Inflammation of the meninges (brain/spinal cord membranes).

Carrier

Person who harbors a pathogen without symptoms but can spread it.

Endotoxin (LPS)

Toxic component of the Gram-negative outer membrane; released when bacteria die, causing severe illness.

Nosocomial infections

Infections acquired in healthcare settings.

Dermatitis

Skin inflammation which can be caused by microorganisms like Pseudomonas.

Cholera

Severe diarrheal disease caused by Vibrio cholerae, typically from contaminated water.

E. coli O157:H7

Pathogenic strain that can cause bloody diarrhea and possible kidney damage.

Exotoxins

Toxic proteins secreted by bacteria that damage host cells.

Enterotoxins

Type of exotoxin that specifically affects the intestines, causing diarrhea.

Neurotoxins

Toxins that affect the nervous system, such as those produced by Clostridium tetani and Clostridium botulinum.

Peptic ulcer

Open sore in the stomach lining caused by Helicobacter pylori.

Tetanus

Condition marked by muscle stiffness/spasms due to neurotoxin produced by Clostridium tetani.

Botulism

Condition characterized by muscle paralysis from neurotoxin produced by Clostridium botulinum.

Endospores

Dormant, highly resistant structures formed by bacteria like Bacillus and Clostridium.

Anthrax

Disease caused by Bacillus anthracis.

Toxic shock syndrome (TSS)

Condition caused by toxins from Staphylococcus aureus.

MRSA

Methicillin-resistant Staphylococcus aureus.

VRSA

Vancomycin-resistant Staphylococcus aureus.

Strep throat

Bacterial throat infection caused by Streptococcus pyogenes.

Pharyngitis

Inflammation of the throat.

Rheumatic fever

Autoimmune complication that can arise after untreated strep throat.

Pneumonia

Lung infection characterized by inflammation and fluid in the air sacs.

Dental caries

Tooth decay caused by specific strains like Streptococcus mutans.

Tuberculosis

Lung infection caused by Mycobacterium tuberculosis, leading to severe symptoms.

Leprosy

Chronic infection affecting skin and nerves, caused by Mycobacterium leprae.

Halophiles

Organisms that thrive in high salt environments.

Piezophiles

Organisms that thrive under high pressure.

Gram-negative bacteria

Bacteria that do not retain the crystal violet stain and often possess an outer membrane.

Coccal bacteria

Bacteria that are spherical in shape.

Facultative anaerobe

Organisms that can grow in both the presence and absence of oxygen.

Obligate anaerobe

Organisms that cannot survive in the presence of oxygen.

Transmissible vector

Pathways of transmission of diseases from one host to another.