Lecture Final Micro Flashcards
study
Using hot water and soap…what type of treatment corresponds to….
Washing dishes in the dishwasher with detergent and hot water is a ____ process.
ANS: Disinfecting
What are disinfectants and their characteristics?
Which of the following statements is TRUE of disinfectants?
ANS: they are used on inanimate surfaces.
What is Sanitization, and mode of action of most common agents?
You notice a sign in a public restroom that states “Sanitized for your safety.” This means
ANS: methods of disinfection that meet minimum standards of microbial removal have been used.
What is pasteurization, and how is it attained? Give examples.
Which of the following describes flash pasteurization?
ANS: heating at 72 degrees C for 15 seconds
Which of the following is an example of pasteurization?
ANS: Heat is used to kill potential pathogens in apple juice.
What are aseptic, sterility, and sanitation, and how do we attain them?
Aseptic means
ANS: Free of pathogens
What are incineration, sanitization, degerming, disinfection, and sterilization?
The process of incineration is used for
ANS: sterilization
Targets of antimicrobial agents on microorganisms.
Antimicrobial agents that damage nucleic acids also affect
ANS: protein synthesis
A chemical agent that dissolves lipids can damage
ANS: cells and enveloped viruses
Target of Beta-lactam and cephalosporin antibiotics.
Beta-lactam antibiotics such as penicillins, have an effect on which of the following types of cells?
ANS: Bacterial cells
Primary advantage of semisynthetic drugs.
Which of the following is a primary advantage of semisynthetic drugs?
ANS: they are more effective than the unmodified natural antibiotics
Drug synergy, cross-resistance, anti-metabolism, chemotherapy, selective toxicity.
The cooperative activity of drugs such as beta-lactam antibiotics and clavilanic acid, a beta-lactamase inhibitor, is known as
ANS: Synergism
Effect of antibiotics on the bacterial cell wall.
The mechanism of action of the antibiotic vancomycin is
ANS: inhibition of cell wall synthesis
Which of the following drugs specifically targets cell walls that contain mycolic acid?
ANS: isoniazid
Azol drugs and their effect on cell membranes.
Azole drugs are antifungal medications that disrupt fungal cell membranes by inhibiting the synthesis of ergosterol, a key component of these membranes. By targeting the enzyme lanosterol 14α-demethylase, azoles prevent ergosterol production, leading to increased membrane permeability and cell damage. There are two main types: imidazoles (e.g., clotrimazole) and triazoles (e.g., fluconazole). While effective against many fungi, resistance and side effects, including liver toxicity and drug interactions, are significant clinical considerations.
Drugs that bind to the isoleucyl-tRNA synthetase and their action.
Drugs like mupirocin and tavaborole bind to isoleucyl-tRNA synthetase, inhibiting this enzyme’s function. This prevents the attachment of isoleucine to its tRNA, disrupting protein synthesis. Mupirocin is used topically for bacterial infections, especially MRSA, while tavaborole treats fungal nail infections. By halting protein production, these drugs effectively stop the growth and survival of bacteria and fungi.
Sulfonamide and targets.
A drug is structurally similar to PABA and inhibits folic acid synthesis. It is most likely a(n)
ANS: Sulfonamide
Which of the following steps in the folic acid synthesis pathway is specifically inhibited by sulfonamides?
ANS: the conversion of PABA to dihydrofolic acid
Quinolones and Fluoroquinolones target
Which of the following drugs inhibits nucleic acid synthesis specifically in most bacteria?
ANS: fluoroquinolones
Plecoranil and targets.
pleconaril dramatically reduced virus levels in target tissues of coxsackievirus serotype B3 strain M-infected animals. Pleconaril represents a promising new drug candidate for potential use in the treatment of human enteroviral infections.
What is an ideal antimicrobial agent?
Antimicrobial agents that damage nucleic acids also affect
ANS: protein synthesis
Which of the following antimicrobial agents is the most toxic to humans?
ANS: ethylene oxide
Which of the following is NOT a desirable characteristic of an ideal antimicrobial agent?
ANS: it only arrests growth of vegetative cells
The Epsilon test (E-test) and the Minimal Inhibitory Concentration
Etest is a quantitative technique for determining the antibiotic sensitivity and minimum inhibitory concentration (in μg/mL) of some bacteria
Consequences of the alteration of the normal microbiota.
Which of the following can result when antibiotic therapy disrupts the normal microbiota?
ANS: both pseudomembranous colitis and thrush
Disruptions of the normal microbiota can result in infections caused by which of the following microbes?
ANS: both Candida albicans and Clostridium difficile
Secondary infections that result from the killing of some of the normal microbiota are called
ANS: superinfections
Normal microbiota may cause disease if conditions change in the body
ANS: TRUE
Staphylococcus aureus as a primary and secondary pathogen.
Staphylococcus aureus as a Primary Pathogen:
Causes Disease in Healthy Individuals: Skin infections (boils, impetigo), pneumonia, sepsis, endocarditis, toxic shock syndrome.
Mechanism: Utilizes toxins, enzymes, and adhesion factors to invade and cause disease.
Staphylococcus aureus as a Secondary Pathogen:
Infects When Predisposing Factors Exist: Hospital-acquired infections (surgical sites, catheters), infections in chronic disease patients (diabetes, HIV), secondary infections post-viral illness (post-influenza pneumonia).
Mechanism: Exploits weakened immune defenses or compromised barriers to establish infection.
Staphylococcus aureus can cause infections both in healthy individuals and those with predisposing factors.
Normal fungal members of the normal human microbiome
Which of the following is NOT considered a member of the normal human microbiota?
ANS: Microsporum
Toxins of the Gram-negative bacteria.
A toxin common to all Gram-negative bacteria is
ANS: lipid A
Virulence factors of S. aureus and their action.
Among the virulence factors produced by Staphylococcus aureus are hemolysin, coagulase, hyaluronidase, and enterotoxin. Which of these factors contribute to the ability of S. aureus to invade the body?
ANS: hyaluronidase
Phases of an infectious and disease process.
Which of the following stages of an infectious disease is the most severe?
ANS: the illness period
Vehicles of microbial transmission.
Which of the following is transmitted by the parenteral route?
ANS: yellow fever
What is a mechanical vector, examples.
Which of the following is considered a mechanical vector transmission?
ANS: cockroach transmission of Shigella
Disease signs and symptoms.
Which of the following is a sign of a disease?
ANS: Fever
Which of the following is a symptom of a disease?
ANS: Fatigue
Examples of symptoms.
Symptoms are
ANS: subjective characteristics of a disease that only the patient can feel
Pathogenesis and virulence factors of Neisseria gonorrhea.
A strain of Neisseria gonorrhea has a mutation which has caused it to lose the ability to produce fimbriae and become less virulent as a consequence. What function has this pathogen lost?
ANS: the ability to adhere to cells of the body
Phases of the disease process
Which of the following stages of an infectious disease is the most severe?
ANS: the illness period
What is iatrogenic, exogenous, opportunistic, endogenous, subacute
Diseases that are induced by modern medical procedures are referred to as
ANS: Iatrogenic
What are the first and second lines of defense against microbes?
Cells of the second line of defense called ____ recognize and kill virus-infected cells.
ANS: NK Cells
Which of the following cells is a component of the body’s first line defense?
ANS: goblet cell
The first and second lines of defense against microbial invasion are part of
ANS: innate immunity
The second line of defense against invading microbes.
The second line of defense against invading microbes includes
ANS: phagocytic white blood cells
Response to specific pathogens with subsequent exposure
Response to specific pathogens that can improve with subsequent exposure is
ANS: the third line of defense
What is fever and its functions?
Fever is beneficial during viral infection because the higher temperature
ANS: increases the effectiveness of interferons.
Granulocytes and agranulocytes
Which of the following leukocytes are called agranulocytes because of the absence of granules in their cytoplasm revealed by basic or acidic dyes?
ANS: lymphocytes
Connection between macrophage and monocytes.
Which cell becomes a macrophage when leaving the bloodstream?
ANS: monocyte
Antibacterial chemicals in tear fluid.
What antibacterial chemical is present in tear fluid?
ANS: lysozyme
Granulocytes and their function.
Antimicrobial peptides on skin and mucosal membranes.
Antimicrobial peptides called ______ are secreted in sweat and damage bacteria and fungi.
ANS: dermcidins