Introduction to Bacteriology – Week 1 Lecture

Vocabulary flashcards covering key terms, scientists, concepts, and techniques introduced in the Week 1 lecture on bacteriology.

Microbiology

The study of microscopic organisms (microbes) that can be seen only with a microscope.

Microbes

Microscopic life forms that may exist as single cells or clusters; include bacteria, viruses, fungi, protozoa, algae, and prions.

Indigenous Microflora

The population of microorganisms normally residing on and in the human body.

Opportunistic Pathogen

A microbe that ordinarily does not cause disease but can do so when host defenses are compromised.

Acellular Microbes

Infectious particles lacking cellular structure, e.g., viruses and prions.

Cellular Microbes

True microorganisms possessing cells; include prokaryotes (bacteria, archaea) and eukaryotes (protozoa, algae, fungi).

Decomposers (Saprophytes)

Microbes that break down dead organisms and waste, recycling nutrients in nature.

Crop Rotation

Agricultural practice that restores soil nutrients with the aid of microbial activity.

Composting

Biological process in which microbes convert organic waste into natural fertilizer.

Biotechnology

Use of living organisms (often microbes) to make products such as enzymes, chemicals, and fermented foods.

Antibiotic

A substance produced by certain microbes (e.g., bacteria, fungi) that inhibits or kills other microorganisms.

Genetic Engineering

Manipulation of microbial DNA to produce substances like insulin, vaccines, growth hormones, or interferons.

Pathogen

A microbe capable of causing disease in a host.

Infectious Disease

Illness in which a pathogen colonizes and damages a host’s body.

Microbial Intoxication

Disease resulting from ingestion of a toxin produced by a microorganism.

Toxin

Poisonous molecule produced by microbes that can harm a host.

Germ Theory of Disease

Concept that specific diseases are caused by specific microorganisms.

Variolation

Early technique of inducing immunity to smallpox by exposing individuals to material from smallpox scabs.

Pasteurization

Heat process devised by Louis Pasteur to kill spoilage microbes in food and beverages.

Attenuated Vaccine

Immunization made from weakened pathogens that elicit immunity without causing disease.

Biogenesis

Principle stating that living cells arise only from pre-existing living cells.

Antiseptic Surgery

Aseptic surgical method introduced by Joseph Lister using phenol to prevent infection.

Koch’s Postulates

Four criteria developed by Robert Koch to prove that a specific microbe causes a specific disease.

Agar

Polysaccharide used as a solidifying agent in microbial culture media, introduced by Angelina Fanny Hesse.

Endospore

Heat-resistant, dormant structure formed by certain bacteria for survival under adverse conditions.

Phagocytosis

Process by which cells engulf and digest particles; discovered by Elie Metchnikoff.

Salvarsan

Arsphenamine compound developed by Paul Ehrlich as the first effective treatment for syphilis.

Penicillin

First true antibiotic, discovered by Alexander Fleming from the mold Penicillium notatum.

Taxonomy

Science of classification, nomenclature, and identification of organisms.

Binomial Nomenclature

System of naming organisms with two Latinized names: Genus (capitalized) and species (lowercase).

Genus

Taxonomic rank grouping species that share important features; first part of a scientific name.

Species

Basic taxonomic unit; collection of strains sharing key genetic and physiological traits.

Family (-aceae)

Taxonomic category containing related genera; family names end in the suffix –aceae.

Subspecies

Taxonomic subdivision within a species, often distinguished by serotype or biotype differences.

Serotype

Subdivision of a microbial species based on distinct antigenic (serologic) characteristics.

Biotype

Subdivision of a species based on unique biochemical properties.

Genotypic Characteristics

Microbial traits determined by DNA/RNA sequences, used for precise identification (e.g., PCR, gene sequencing).

Phenotypic Characteristics

Observable microbial traits such as cell shape, Gram reaction, colony morphology, motility, and biochemical activities.

Prokaryote

Cell lacking a true nucleus and membrane-bound organelles; DNA is circular and free in cytoplasm (e.g., bacteria, archaea).

Eukaryote

Cell with a membrane-bound nucleus and organelles; includes animals, plants, fungi, algae, protozoa.

Binary Fission

Asexual reproduction method in which a prokaryotic cell divides into two identical daughter cells.

Flagellum

Long whip-like appendage providing motility to many bacteria and some eukaryotic cells.

Cilium

Short, hair-like structure used mainly for movement or adherence by eukaryotic cells; absent in bacteria.

Catalase Test

Biochemical assay detecting the enzyme catalase; differentiates microbes by ability to break down hydrogen peroxide.

Oxidase Test

Biochemical test identifying bacteria that produce cytochrome c oxidase enzyme.

Girolamo Fracastoro

Renaissance scholar who proposed that invisible living creatures cause disease (early germ theory).

Antonie van Leeuwenhoek

First to observe live bacteria and protozoa; called them “animalcules”; Father of Protozoology and Bacteriology.

Ignaz Semmelweis

Physician who introduced handwashing with chlorinated water to reduce puerperal infections; Father of Hand Hygiene.

Louis Pasteur

Father of Modern Microbiology; disproved spontaneous generation, developed vaccines, pasteurization, germ theory.

Joseph Lister

Surgeon who applied antiseptic principles in surgery using phenol, dramatically reducing postoperative infections.

Robert Koch

Father of Modern Bacteriology; identified causative agents of TB, cholera, anthrax; formulated Koch’s Postulates.

Ferdinand Cohn

Early bacteriologist who classified bacteria by shape and discovered endospores.

Angelina Fanny Hesse

Introduced agar as a solidifying agent for bacterial culture media.

Elie Metchnikoff

Zoologist who discovered phagocytosis, laying groundwork for cellular immunology.

Paul Ehrlich

Chemotherapist who developed Salvarsan and pioneered the concept of selective toxicity.

Alexander Fleming

Discovered penicillin in 1928, initiating the antibiotic era.

Carolus Linnaeus

“Father of Taxonomy”; created the binomial nomenclature system for classifying living organisms.