Bacte Quiz

taxonomy

The classification of organisms into categories based on genotypic and phenotypic characteristics

species

Is the most basic taxonomic group and encompasses bacterial strains with common genetic, physiologic, and phenotypic characteristics.

genus

Different species with many important features in common are known as a

cytoskeleton

supports the cell and also various organelles, such as the nucleus, mitochondria, endoplasmic reticulum, Golgi bodies, and lysosomes.

1-3 um

Bacterial cells range from _________in length and thus are not visible to the human eye without the aid of a microscope.

cytosol

Contains many enzymes and is the site of most metabolic processes for the bacterial cell.

bacterial chromosome

Is one double-stranded circle contained in a discrete area of the cytoplasm, known as the nucleoid.

Plasmids

Are small, circular extrachromosomal DNA may also be found in the cytoplasm. They play a role in the development of antibiotic resistance.

polysomes

Site of protein formation of bacteria

pili

hair-like extensions that extend into the environment, it also permit the organism to attach to the host cells, and sex pili

Monotrichous

flagella are located at one end of the cell

Lophotrichous

Flagella are located on both ends of the cell

Peritrichous

Flagella cover the entire bacterial surface

Capsules

Are poor antigens and are antiphagocytic and important virulence factors for bacteria. It may serve as barriers to hydrophobic compounds such as detergents and can enable the bacteria to adhere to other bacteria or to host surfaces.

periplasmic space

Contains the murein layer and a gel-like structure that assists the bacteria in obtaining nutrients.

Murein

This layer provides stability and strength to the bacterial cell and blocks the passage of some macromolecules.

Teichoic acids

Are water-soluble polymers of polyol phosphates bound to peptidoglycan and essential for the viability of the cell.

Lipoteichoic acids

Contain a fatty acid and are important as surface antigens to differentiate bacterial serotypes.

Lipid A

is associated with endotoxin activity; its structure is similar for closely related bacteria.

Core polysaccharide

is important structurally and for the viability of the bacterial cell.

O antigen

Is important in differentiating serotypes or strains of a bacterial species.

Porins

Present in the outer membrane contain water and help regulate the passage of nutrients, antibiotics, and other hydrophilic compounds into the cell.

Exotoxins

are associated with gram- positive organisms and are secreted by the living bacterial cell.

Endotoxins

Are usually associated with gram-negative bacteria and consist of lipopolysaccharide (LPS), the component of the cell wall.

Colonization

refers to the state when the microbe has established itself in a particular niche or body site.

Immunity

Refers to host properties that confer resistance of the host to foreign substances. It is the sum of all mechanisms used by the body as protection against environmental agents that are not normally present in the body.

Lysozyme

An enzyme that lyses bacterial cell walls, is also present in respiratory secretions.

clean-catch midstream method

The specimen of choice for bacterial culture of urine

Bacteremia

Refers to the presence of bacteria in blood, which is considered a sterile site

septicemia

The circulating bacteria multiply faster than phagocytosis can occur, and multiple organs and body systems may be infected.

121 degrees Celsius at 15 psi for 1 hour

Autoclave is operated at _______ to sterilize most contaminated microbiological materials

132 degrees Celsius for 1/2 to 1 hour

Infectious medical waste is usually autoclaved at _________

Disinfection

destroys most microbes but does not kill the spores.

Corrosive

causes visible destruction or irreversible damage to human skin on contact

Toxic

Serious biological effects after inhalation, in- gestion, or skin contact with relatively small amounts

Carcinogenic

It has the ability of chemical to induce a malignant tumor

Ignitable

Any chemical that can burn and includes both combustible and flammable liquids

Explosive

Reactive and unstable substances that readily undergo violent chemical change

Direct inoculation

An infection that may occur as a result of accidental needlesticks or through broken glass is classified as which of the following routes?

BSL 2

The Biosafety Level that includes most common laboratory microorganisms and involves organisms such as HBV, HIV, and enteric pathogens is:

Class II

Which of the following biological safety cabinets sterilize both the air entering and leaving the cabinet and utilize a HEPA filter?

Sterilizer

Which germicide is intended to destroy all microorganisms and their spores on inanimate surfaces?

Fastidious bacteria

Are those organ- isms that require special cultivation measures, such as enriched media or special atmospheric conditions such as increased carbon dioxide (CO2).

3rd or 4th

Cerebrospinal fluid (CSF) is collected by lumbar puncture in the ________lumbar vertebra by a physician.

broth

Media in liquid form are known as

agar

When the medium is in a gel or semisolid form, it is known as

General Isolation Media

Also known as supportive media, support the growth of most nonfastidious bacte- ria. Examples include nutrient agar, trypticase soy agar, and nutrient broth. No growth advantage is given to any group of bacteria.

Nonselective Isolation Media

also known as
enriched media, contain a nutrient supplement. Examples include sheep blood agar (SBA) and chocolate agar

Alpha

Hemolytic pattern: incomplete; greening or browning of the medium

Beta

Hemolytic pattern: Complete; total clearing of the medium

Gamma

Hemolytic pattern: No change in the color of the medium

Differential media

provide distinct colonial appearances of microorganisms to aid in their identification.

Selective media

Contain agents that inhibit the growth of all bacteria except those that are sought. These media allow one to select for pathogens through the inhibition of normal flora

mesophilic

Most pathogenic bacteria are_____________, preferring a growth temperature of 30°C to 45°C.

thermophiles

limited number of pathogens are classified as ___________ and prefer a growth temperature greater than 40°C

Psychrophiles

prefer growing at lower temperatures, such as 4°C to 20°C

Aerobic

Bacteria that require molecular oxygen for cellular respiration and thus require incubation in the presence of atmospheric oxygen.

Obligate aerobes

Have an absolute oxygen requirement, needing it as the terminal electron acceptor for cellular respiration. An example of a strict aerobe is Pseudomonas.

Facultative bacteria

Can multiply in the presence or absence of oxygen and are able to use oxygen as the final electron acceptor in cellular respiration. However, they also can acquire energy through fermentation. It include Staphylococcus and members of the Enterobacteriaceae

Obligate anaerobes

Are unable to multiple in the presence of oxygen and require incubation in an anaerobic environment, such an in anerobic jar. Examples includes Clostridium and Bacteroides.

Capnophilic

certain bacteria prefer to grow in the presence of 5% to 10% CO2 with small amounts of oxygen and are categorized as

Catalase

The test is important in the differentiation of gram-positive cocci: Staphylococcus are catalase positive, and Streptococcus are catalase negative.

Coagulase

Fibrinogen is converted to fibrin in the presence of the enzyme____________

Bound coagulase

is detected in the coagulase slide test, which is performed by mixing the colony with a drop of rabbit plasma; a positive reaction is shown by the presence of fibrin clots.

slide test

A negative control of rabbit plasma mixed with saline must be used in the _______.

Bacillus stearothermophilus

The effectiveness of autoclaves should be tested using a spore strip of ____________________

35-37 degrees celsius

Most pathogenic bacteria prefer an incubation temperature of:

Capnophiles

Those bacteria that prefer growth under increased CO2 are known as:

Resolving power

Refers to the ability to distinguish be- tween two adjacent points. It depends on the wavelength of light and the numerical aperture.

Condenser

Gather light rays and focus these on the object to be illuminated.

Darkfield microscope

the specimen appears luminous against a background of little or no light.

Saline mount

This method permits one to detect the presence of bacteria in a specimen and also to observe for motility.

Hanging drop

This technique is used primarily to observe for motility of the organism, al- lowing for less distortion when compared with the saline mount method.

Iodine mount

This technique is used to stain stools for parasitic ova whose nuclei appear orange to brown.

Potassium hydroxide

dissolves tissue, such as skin, hair, or nails, making the fungal elements more visible.

India ink

once the preferred method to detect capsules, produces a black, semi-opaque background, which makes the clear capsule more visible.

Neufeld reaction

was also used in the past to detect capsular antigen

Simple stains

Impart the same color to all structures,

Differential stains

Contain more than one dye and impart different colors to various structures.

smear

The first step in staining is the preparation of a _______

methylene blue

In the ____________ stain, the specimen can be observed for the presence of microorganisms as well as for their size, shape, and morphology.

Gram stain

The _________will differentiate gram-positive bacteria from gram-negative bacteria.

Hans Christian Gram

Gram Stain was first introduced by _____________

Streptococcus prnumoniae

is an example of lancet-shaped diplococci,

Neisseria

form tiny diplococci that resemble kidney beans

Staphyloccocci

typically form grape-like clusters.

Fusiform

bacilli taper at both ends

Filamentous

Bacilli that appear as long threads that do not appear to separate.

Campylobacter

Curved bacilli may be small and comma shaped, as with __________

Vibrio

slightly coiled with one spiral, as with ________

Spirochetes

Are coiled bacteria, such as Treponema, which may possess four to 20 coils. They do not Gram stain well.

Acid Fast Stains

Are used to stain mycobacteria that possess thick, waxy cell walls.

Crystal Violet

Primary stain: stains all bacteria blue to purple

Gram’s Iodine

Mordant: enhances reaction between cell wall and primary stain

Safranin

Counterstain: no effect on gram-positive bacteria; stains gram-negative bacteria pink to red

Rhodamine-auramine

Is a fluorescent stain used to stain mycobacteria. The stains bind to the mycolic acid in the organism’s cell wall, staining the bacteria yellow to orange.

Antibodies

Are specific proteins produced in response to exposure to antigens of a particular organism.

Antibiotics

are chemical substances produced by microorganisms that inhibit the growth of other microorganisms.

Antimicrobial agents

Are agents that destroy microorganisms through inhibiting their development or pathogenic action.

Bacteriocidal agents

kill the microbe, resulting in cell lysis