Microbiology Quiz: Bacteria and Immunology

The minimum amount of water (ml) in which E. coli is detected.

Viruses, Rickettsia, and Chlamydia are all obligate parasites. This means they must live inside a living host cell to survive and reproduce.

The reproduction of a virus within a host cell is called viral replication.

The capsule surrounding some bacteria is antigenic, meaning it can trigger an immune response and the production of antibodies in the host.

Viruses reproduce inside host cells, typically in cell culture.

Klebsiella is a bacterium known to possess a well-developed capsule.

Phages, or bacteriophages, reproduce by a process called the lytic cycle, where they infect and destroy the host bacterial cell.

MPB (meat peptone broth) is a common universal culture media used for growing bacteria.

Fibrinolysin is a type of bacterial enzyme that breaks down fibrin, a protein that helps form blood clots. This enzyme can contribute to bacterial invasion by helping them spread through the body.

Mycobacteria are known for their resistance to drying. This is why they can survive in harsh environments and are difficult to eradicate.

The period in which Louis Pasteur made significant contributions to the field of microbiology, marked by groundbreaking discoveries.

A chemical process involving aniline dyes that are selectively adsorbed to microorganisms, allowing visualization and differentiation.

The method of differentiating bacteria based on their cell wall composition, specifically the presence or absence of peptidoglycan, using crystal violet and safranin dyes.

A process where bacteria form protective resistant structures called endospores in response to unfavourable environmental conditions like lack of nutrients or water.

A type of fatty acid that forms a waxy layer in certain bacteria, making them resistant to acids and common disinfectants.

A staining technique for detecting bacteria with high mycolic acid content, specifically Mycobacteria, using carbolfuchsin and acid alcohol.

A method used to identify bacterial flagella by coating them with silver nitrate, making them visible under a microscope.

A technique used to visualize bacterial capsules by using a negative stain, leaving a clear halo around the bacterial cells.

A population of bacteria originating from a single parent cell, containing identical genetic material.

Prokaryotes lack a true nucleus and membrane-bound organelles, while eukaryotes have a nucleus and other membrane-bound organelles.

Bacteria with flagella located at both ends of the cell.

A genus of obligate intracellular bacteria that are typically rod-shaped and often associated with diseases like typhus and Rocky Mountain spotted fever.

Bacterial cells lacking a cell wall, often resulting from antibiotic treatment or mutations.

Bacterial cells that have a partially degraded cell wall, usually due to antibiotic treatment or mutations.

A widely recognized system for classifying microorganisms, developed by David Hendricks Bergey and updated over time, used for grouping and identifying bacteria.

A technique used to transfer bacterial colonies from one agar plate to another while maintaining the original arrangement of colonies. It's used to identify bacteria that have been transformed with new genetic material.

A bacterium that does not produce any pigment. It lacks the genes or enzymes necessary to synthesize pigments.

A sterilization method that uses physical or chemical agents to kill all microorganisms, including bacterial endospores. Examples include autoclaving and using ethylene oxide gas.

A technique for staining bacteria to visualize their morphology and characteristics, but using a dye that has negative charge, repelling the negatively charged bacterial cell wall. Hence, the background around the bacteria gets stained, while the bacteria remain unstained and appear clear against a dark background.

A technique used to amplify specific DNA sequences from a sample. It is used to detect, identify, and analyze DNA from a variety of sources, including bacteria, viruses, and human cells.

A bacterium that has flagella distributed all around its surface. It is motile and can swim in a variety of directions.

A prion disease is caused by a misfolded protein, called a prion, which can cause other proteins to misfold, leading to the formation of aggregates in the brain and other organs.

The time it takes for a bacterial population to double in size under optimal conditions.

Bacteria that require specific organic compounds, known as growth factors, for their growth. They cannot synthesize these essential compounds themselves and rely on external sources.

Permeases are proteins embedded in the bacterial cell membrane. They act as carriers, facilitating the transport of nutrients from the external environment into the bacterial cell.

Lead acetate is a reagent used to detect the production of hydrogen sulfide (H2S) by bacteria. When H2S is produced, it reacts with lead acetate to form a black precipitate.

Bacterial endotoxin is a lipopolysaccharide (LPS) found in the outer membrane of gram-negative bacteria. It is a potent immunostimulant, triggering inflammation and immune responses.

The aspiration or sedimentation method is used to determine the number of microbes in the air. It involves collecting air samples using a specific device and then culturing the collected microbes on appropriate media.

Tyndallization is a sterilization method that involves repeated heating and cooling cycles. It is used for materials that cannot withstand high temperatures, like heat-sensitive media.

Interferons are proteins produced by cells in response to viral infections. They have antiviral activity, interfering with viral replication and spreading.

Penicillin inhibits the synthesis of peptidoglycan, a major component of the bacterial cell wall. This disruption weakens the cell wall, leading to cell lysis and death.

Staphylococcal resistance to penicillin can arise due to the presence of plasmids, which carry genes encoding penicillinase enzymes. These enzymes break down penicillin, rendering it ineffective.

Fusobacteria are obligate members of the oral cavity's microflora. They contribute to the balance of the oral microbiome.

The ability of a microbe to synthesize and release acetylmethylcarbinol, a compound detectable in a Voges-Proskauer test.

Aerobic respiration involves a series of biochemical reactions where electrons are passed along an electron transport chain, generating ATP through oxidative phosphorylation. This process requires oxygen as the final electron acceptor.

Virulence factors are mechanisms that allow pathogens to cause disease. These include traits like toxin production, invasiveness, and capsule formation, which help them evade the host's immune system or damage host tissues.

Superinfection refers to a new infection, often by a different microbe, that occurs during or after treatment for a previous infection. This can happen due to weakened immune defenses or changes in the microbiome.

Stool samples are crucial for investigating foodborne toxic infections. They allow the identification of the causative agent, analysis of toxins, and assessment of the severity of the infection.

A subpopulation of T-lymphocytes that plays a role in suppressing immune responses, preventing overreaction to antigens.

Klebsiella microbes are known for their thick capsules that protect them from phagocytosis by immune cells. This contributes to their ability to cause serious infections.

Encapsulated microbes can lead to severe infections with a poor response to treatment. Their capsules protect them from immune defenses, making them harder to eliminate.

Infection spread through the lymphatic system, involving movement of pathogens through lymph vessels and nodes.

A bacterial cell structure that is not a membrane, but rather a protective outer layer.

Clostridium botulinum is a spore-forming, Gram-positive rod. It produces a potent neurotoxin that causes botulism, a serious paralytic illness.

A type of symbiosis where one organism benefits, while the other is neither harmed nor benefited.

The ability of the immune system to remember specific pathogens and mount a faster and more effective response upon re-exposure.