Peptidoglycan Synthesis and Cell Division Machinery Quiz
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Questions and Answers

Which process of reproduction is common in most bacteria?

  • Mitosis
  • Budding
  • Binary fission (correct)
  • Meiosis

    • What is the temperature range for psychrophiles and their optimum temperature?

  • 10 ° to 50 °, optimum between 20 ° and 40 °
  • 45 ° and 80 °, optimum between 60 ° and 70 °
  • -5 ° to 20 °, optimum between 15° and 35° (correct)
  • 0 ° to 35 °, optimum less than 20 °

    • What type of bacteria live at high temperatures and are associated with volcanic activities or exposed directly to the sun?

  • Psychrophiles
  • Mesophiles
  • Thermophiles (correct)
  • Hyperthermophiles

    • What is the target of Aminoglycosides antibiotics?

    <p>Protein synthesis in 30S ribosome</p> Signup and view all the answers

    What is the generation time?

    <p>Time necessary to the duplication of a bacterial cell</p> Signup and view all the answers

    What is the lowest concentration that kills 99.9% of the original inoculum in vitro?

    <p>Minimum bactericidal concentration (MBC)</p> Signup and view all the answers

    What is the cause of resistance to antiviral drugs?

    <p>Changes in relevant part of the virus genome</p> Signup and view all the answers

    Which of the following is true about transduction?

    <p>It transfers genes via a phage vector</p> Signup and view all the answers

    Which bacterial species produces an alginate mucous layer for adherence?

    <p>Pseudomonas aeruginosa</p> Signup and view all the answers

    What gives Streptococcus pyogenes its adhesion ability?

    <p>Protein F and lipotheic acid</p> Signup and view all the answers

    Which type of bacteria are naturally resistant to hydrophobic antibiotics?

    <p>Gram-negative</p> Signup and view all the answers

    What is the mode of action of quinolones?

    <p>They prevent supercoiling of DNA</p> Signup and view all the answers

    Which type of bacteria are sulfamidics effective against?

    <p>Both Gram-positive and Gram-negative</p> Signup and view all the answers

    What is MRSA?

    <p>A type of bacteria that is resistant to methicillin</p> Signup and view all the answers

    What is the mechanism of resistance to beta-lactam antibiotics caused by bacterial enzymes?

    <p>Production of beta-lactamase</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>Inhibiting cell wall synthesis</p> Signup and view all the answers

    What is the mechanism of action of aminoglycosides?

    <p>Inhibiting protein synthesis</p> Signup and view all the answers

    What do beta-lactamase inhibitors do?

    <p>Bind and inactivate beta-lactamase</p> Signup and view all the answers

    Which type of bacteria is Thiomargarita namibiensis?

    <p>A gram-negative Proteobacterium</p> Signup and view all the answers

    What is the function of the Mesosome in bacterial cells?

    <p>Anchorage and duplication of bacterial DNA</p> Signup and view all the answers

    Which group of bacteria has teichoic acids in their cell walls?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the main proposal to combat antimicrobial resistance mentioned in the text?

    <p>Use more narrow spectrum antibiotics</p> Signup and view all the answers

    Which of the following is a possible cause of antibiotic resistance?

    <p>Inadequate surveillance</p> Signup and view all the answers

    Which type of bacteria are penicillins most effective against?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the difference between cephalosporins and cephamycins?

    <p>Cephamycins are more stable to beta-lactamase hydrolysis</p> Signup and view all the answers

    What are the targets for penicillin and other beta-lactam antibiotics?

    <p>Penicillin-binding proteins (PBPs)</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space containing enzymes and is capable of producing beta-lactamase to disrupt antibiotics?

    <p>Gram-negative</p> Signup and view all the answers

    Which component of the Gram-negative bacterial cell wall is responsible for inducing inflammation by promoting the release of acute phase cytokines?

    <p>Lipid A</p> Signup and view all the answers

    Which staining method can be used to visualize Mycobacteria despite the presence of waxes in their cell walls?

    <p>Ziehl-Neelsen staining</p> Signup and view all the answers

    What is the function of peptidoglycan in bacteria?

    <p>It is essential for the structure, form, replication, and survival of bacteria</p> Signup and view all the answers

    What is the mode of action of spectinomycin?

    <p>It reversibly interferes with m-RNA interaction with the 30S ribosome</p> Signup and view all the answers

    What is the spectrum of activity of tetracyclines?

    <p>Broad-spectrum against gram positive and some gram negative bacteria</p> Signup and view all the answers

    What is the mode of action of chloramphenicol?

    <p>It binds to the 50S ribosome and blocks the peptide extension</p> Signup and view all the answers

    What is the mode of action of rifampicin?

    <p>It binds to DNA-dependent RNA polymerase and inhibits initiation of mRNA synthesis</p> Signup and view all the answers

    What is the role of bactoprenol in peptidoglycan synthesis?

    <p>Bactoprenol transports peptidoglycan monomers across the cytoplasmic membrane</p> Signup and view all the answers

    What is the function of autolysins in peptidoglycan synthesis?

    <p>Autolysins break the glycosidic bonds between peptidoglycan monomers at the point of growth along the existing peptidoglycan</p> Signup and view all the answers

    What is the role of transglycosidase enzymes in peptidoglycan synthesis?

    <p>Transglycosidase enzymes catalyze the formation of glycosidic bonds between the NAM and NAG of the peptidoglycan monomers and the NAG and NAM of the existing peptidoglycan</p> Signup and view all the answers

    What is the process by which bacteria transfer genes from one cell to another by cell-to-cell contact?

    <p>Conjugation</p> Signup and view all the answers

    What is the optimal growth temperature range for thermophilic bacteria?

    <p>45 ° and 80 °</p> Signup and view all the answers

    What is the temperature range for psychrophiles?

    <p>-5 ° and 20 °</p> Signup and view all the answers

    Which type of bacteria are responsible for the deterioration of chilled foods?

    <p>Optional psychrophiles</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space containing enzymes and is capable of producing beta-lactamase to disrupt antibiotics?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    Which bacterial species is the world's largest bacteria, found in the ocean sediments of the coast of Namibia?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which type of bacteria has teichoic acids in their cell walls that promote adhesion to target tissue and have antigenic properties?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    Which type of bacteria has a spiral form and a cell membrane without sterols, but with terpenoids that stabilize and compact it?

    <p>Spirochetes</p> Signup and view all the answers

    Which of the following is a virulence factor of bacteria?

    <p>Alginate mucous layer</p> Signup and view all the answers

    What is the role of protein F and lipotheic acid in Streptococcus pyogenes adhesion?

    <p>Mediate adhesion to skin cells</p> Signup and view all the answers

    What is transduction in bacteria?

    <p>Transfer of genes from one cell to another via a phage vector</p> Signup and view all the answers

    What is the mode of action of macrolides?

    <p>They inhibit translocation</p> Signup and view all the answers

    Which antibiotic is used in the treatment of penicillin-resistant Neisseria gonorrhoeae?

    <p>Spectinomycin</p> Signup and view all the answers

    What is the spectrum of activity of rifampicin?

    <p>Broad-spectrum against gram-positive and some gram-negative bacteria</p> Signup and view all the answers

    What is the mode of action of tetracyclines?

    <p>They reversibly bind to the 30S ribosome and inhibit binding of aminoacyl-t-RNA</p> Signup and view all the answers

    What is the primary cause of antibiotic resistance?

    <p>Abuse of antibiotics in animals and foods</p> Signup and view all the answers

    Which type of bacteria are penicillins most effective against?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the difference between cephalosporins and cephamycins?

    <p>Cephalosporins contain oxygen in place of sulfur in the dihydrothiazine ring, while cephamycins contain sulfur</p> Signup and view all the answers

    What is the mechanism by which bacteria become resistant to beta-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    Which of the following is a mechanism of resistance to beta-lactam antibiotics?

    <p>Production of beta-lactamase that disrupts the beta-lactam ring of the antibiotic</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>Inhibits proper cell wall synthesis in Gram-positive bacteria</p> Signup and view all the answers

    What is the spectrum of activity of aminoglycosides?

    <p>Many gram-negative and some gram-positive bacteria</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors such as clavulanic acid and sulbactam?

    <p>Bind and inactivate beta-lactamase, allowing penicillins to enter the bacterial cell without undergoing enzymatic degradation</p> Signup and view all the answers

    What is the target of Macrolides antibiotics?

    <p>Elongation phase in 50S ribosome</p> Signup and view all the answers

    Which bacterial strain requires a small number of cells to begin an infection?

    <p>Enterohemorrhagic strains of Escherichia coli</p> Signup and view all the answers

    What is the minimum inhibitory concentration (MIC)?

    <p>The lowest concentration that results in inhibition of visible growth</p> Signup and view all the answers

    What is the consequence of antibiotic treatment on the gastrointestinal tract?

    <p>Proliferation of Enterococcus, Pseudomonas, and fungi</p> Signup and view all the answers

    What is the mode of action of quinolones?

    <p>They bind to the A subunit of DNA gyrase and prevent supercoiling of DNA</p> Signup and view all the answers

    What is the spectrum of activity of sulfamidics?

    <p>Broad range activity against gram-positive and gram-negative bacteria</p> Signup and view all the answers

    What is the mechanism of resistance to quinolones?

    <p>Modification of DNA gyrase that can not bind the drug anymore</p> Signup and view all the answers

    What is the mode of action of sulfonamides?

    <p>They competitively inhibit formation of dihydropteroic acid</p> Signup and view all the answers

    What is the key difference between the cell walls of Gram-positive and Gram-negative bacteria?

    <p>Gram-positive bacteria have teichoic and lypoteichoic acids, while Gram-negative bacteria do not</p> Signup and view all the answers

    What is the function of Lipid A in Gram-negative bacteria?

    <p>It is the toxic part of LPS and promotes the release of acute phase cytokines inducing inflammation</p> Signup and view all the answers

    What is the main function of Mycolic acids in Mycobacterium?

    <p>They allow bacterial survival for a prolonged time despite adverse conditions</p> Signup and view all the answers

    What is the primary staining used in the Gram staining technique?

    <p>Crystal violet hydrophilic</p> Signup and view all the answers

    Which temperature range do thermophiles live in?

    <p>45 ° and 80 °</p> Signup and view all the answers

    What is the asexual process of reproduction in bacteria called?

    <p>Binary fission</p> Signup and view all the answers

    Which type of bacteria are most microorganisms, including human pathogens?

    <p>Mesophiles</p> Signup and view all the answers

    Which enzyme catalyzes the formation of glycosidic bonds between the NAM and NAG of peptidoglycan monomers and the existing peptidoglycan in bacteria?

    <p>Transglycosidase</p> Signup and view all the answers

    What is the role of autolysins in peptidoglycan synthesis in bacteria?

    <p>Breaking peptide cross-bridges between rows of sugars</p> Signup and view all the answers

    What is the mode of action of vancomycin against bacteria?

    <p>It binds the peptides of the peptidoglycan monomers and blocks the formation of glycosidic bonds between the sugars by the transglycosidase enzymes</p> Signup and view all the answers

    What is the process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment?

    <p>Transformation</p> Signup and view all the answers

    Which bacterial species is associated with adhesion to heart valves or catheters due to its alginate mucous layer?

    <p>Pseudomonas aeruginosa</p> Signup and view all the answers

    What is transduction in bacteria?

    <p>Transfer of genes from one cell to another via a phage vector without cell-to-cell contact</p> Signup and view all the answers

    What are virulence factors?

    <p>Constituents of the bacterial cell or products of bacterial metabolism</p> Signup and view all the answers

    Which of the following antibiotics is effective against gram-positive cocci and urinary tract infections?

    <p>Sulfamidics</p> Signup and view all the answers

    What is the mode of action of quinolones?

    <p>Inhibit DNA synthesis</p> Signup and view all the answers

    Which type of bacteria are broad-spectrum quinolones active against?

    <p>Both gram-positive and gram-negative</p> Signup and view all the answers

    What is MRSA?

    <p>A type of bacteria that is resistant to several antibiotics</p> Signup and view all the answers

    Which of the following is a mechanism of resistance to beta-lactam antibiotics?

    <p>Hydrolysis of the antibiotic by bacterial enzymes</p> Signup and view all the answers

    What is the mode of action of Vancomycin?

    <p>Inhibiting proper cell wall synthesis in gram-positive bacteria</p> Signup and view all the answers

    Which type of bacteria are aminoglycosides the first choice for treating?

    <p>Gram-negative bacilli</p> Signup and view all the answers

    What is the mechanism of resistance to aminoglycosides?

    <p>Mutations in the binding site to the ribosome</p> Signup and view all the answers

    What is the main cause of antibiotic resistance in bacteria?

    <p>Abuse of antibiotics in animals and foods</p> Signup and view all the answers

    Which type of bacteria are penicillins most active against?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the mechanism by which bacteria become resistant to beta-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    What is the main characteristic of carbapenems compared to other beta-lactam antibiotics?

    <p>Very broad bacterial spectrum</p> Signup and view all the answers

    Which of the following is a consequence of antibiotic treatment?

    <p>Decreased susceptibility of gastrointestinal tract microbes</p> Signup and view all the answers

    Which of the following is a mechanism of resistance to antibacterial drugs?

    <p>Prevention of penetration of drug</p> Signup and view all the answers

    What is the minimum infective dose for enterohemorrhagic strains of Escherichia coli?

    <p>10 cells</p> Signup and view all the answers

    What is the difference between an antibiotic and an antimicrobial agent?

    <p>An antibiotic kills microorganisms, while an antimicrobial agent only inhibits their growth</p> Signup and view all the answers

    What is the world's largest bacteria and where is it found?

    <p>Thiomargarita namibiensis found in ocean sediments off the coast of Namibia</p> Signup and view all the answers

    Which of the following bacteria are classified as cocci?

    <p>Streptococcus pneumoniae and Staphylococcus aureus</p> Signup and view all the answers

    Which type of bacteria has a cell membrane without sterols, but with terpenoids that stabilize and compact it?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    What is the composition of the cell wall of gram-positive bacteria?

    <p>Peptidoglycan and teichoic acids</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space between the cytoplasmic membrane and the external membrane?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    What is the endotoxin that characterizes the pathogenic feature of Gram-negative bacteria?

    <p>LPS</p> Signup and view all the answers

    What is the function of mycolic acids in the cell wall structure of Mycobacteria?

    <p>To form waxes that protect the bacteria from drying and disinfectants</p> Signup and view all the answers

    What is the primary staining agent used in Gram staining?

    <p>Crystal violet</p> Signup and view all the answers

    What is the mode of action of spectinomycin?

    <p>Spectinomycin reversibly interferes with m-RNA interaction with the 30S ribosome.</p> Signup and view all the answers

    What is the spectrum of activity of chloramphenicol?

    <p>Narrow-spectrum, only used in the treatment of typhoid fever or bacterial meningitis.</p> Signup and view all the answers

    What is the mode of action of fusidic acid?

    <p>Fusidic acid binds to elongation factor G and inhibits release of EF-G from the EF-G/GDP complex.</p> Signup and view all the answers

    What is the mechanism of action of rifampicin?

    <p>Rifampicin binds to DNA-dependent RNA polymerase and inhibits initiation of mRNA synthesis.</p> Signup and view all the answers

    What is the role of bactoprenol in peptidoglycan synthesis?

    <p>It transports the peptidoglycan monomers across the cytoplasmic membrane</p> Signup and view all the answers

    What is the mechanism of action of vancomycin?

    <p>It binds the peptides of the peptidoglycan monomers and blocks the formation of glycosidic bonds between the sugars by the transglycosidase enzymes</p> Signup and view all the answers

    What is the function of autolysins in peptidoglycan synthesis?

    <p>They break the glycosidic bonds between the peptidoglycan monomers and the peptide cross-bridges that link the rows of sugars together</p> Signup and view all the answers

    What is bacterial transformation?

    <p>The process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment</p> Signup and view all the answers

    What is the process of asexual reproduction in bacteria called?

    <p>Binary fission</p> Signup and view all the answers

    What is the temperature range for thermophiles?

    <p>45 ° to 80 °</p> Signup and view all the answers

    Which group of bacteria are responsible for the deterioration of chilled foods?

    <p>Psychrophiles</p> Signup and view all the answers

    Which of the following is a mechanism of transduction?

    <p>Transfer of genes from one cell to another via a phage vector without cell-to-cell contact</p> Signup and view all the answers

    Which bacterial species produces an alginate mucous layer that allows the anchoring of bacteria to the cell surface, particularly in patients suffering from cystic fibrosis or other respiratory diseases?

    <p>Pseudomonas aeruginosa</p> Signup and view all the answers

    Which two constituents of bacteria can act as virulence factors?

    <p>Bacterial cell and bacterial metabolism</p> Signup and view all the answers

    What is the main reason for the emergence of bacterial resistance to antibiotics?

    <p>Abuse of antibiotics in animals and foods</p> Signup and view all the answers

    Which of the following antibiotics is active against most gram-positive bacteria such as staphylococci and streptococci?

    <p>Penicillins</p> Signup and view all the answers

    What is the general mechanism by which bacteria become resistant to beta-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    Which of the following is a characteristic of Carbapenems?

    <p>Hydrolytically stable to almost all beta-lactamase enzymes</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space containing enzymes and is capable of producing beta-lactamase to disrupt antibiotics?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    What is the endotoxin that characterizes the pathogenic feature of gram-negative bacteria?

    <p>Lipid A</p> Signup and view all the answers

    What is the primary staining used in Gram staining?

    <p>Crystal violet</p> Signup and view all the answers

    What is the function of peptidoglycan in bacteria?

    <p>It protects bacteria from drying and disinfectants</p> Signup and view all the answers

    Which of the following is NOT a way to combat antimicrobial resistance?

    <p>Use broad spectrum antibiotics</p> Signup and view all the answers

    Which of the following is the world's largest bacteria?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which of the following is NOT a way to classify bacteria?

    <p>By their habitat preference</p> Signup and view all the answers

    Which of the following is a characteristic of gram-positive bacteria?

    <p>The cell wall contains teichoic acids</p> Signup and view all the answers

    Which type of bacteria can begin an infection with only a small number of cells in the initial inoculum?

    <p>Escherichia coli</p> Signup and view all the answers

    What is the principal mechanism of resistance to antibacterial drugs that involves enzymatic drug destruction or inactivation?

    <p>Enzymatic drug destruction or inactivation</p> Signup and view all the answers

    What is the difference between an antibiotic and an antimicrobial agent?

    <p>Antibiotics kill microorganisms, while antimicrobial agents inhibit their growth</p> Signup and view all the answers

    What is the minimum bactericidal concentration (MBC)?

    <p>The lowest concentration that kills 99.9% of the original inoculum</p> Signup and view all the answers

    What is the mode of action of vancomycin against Gram-positive bacteria?

    <p>It inhibits proper cell wall synthesis.</p> Signup and view all the answers

    What is the mechanism of resistance to beta-lactam antibiotics caused by mutations in the PBPs?

    <p>They do not allow the binding with the antibiotic.</p> Signup and view all the answers

    What is the mode of action of aminoglycosides against bacteria?

    <p>They inhibit protein synthesis.</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors like clavulanic acid and sulbactam?

    <p>They bind and inactivate beta-lactamase.</p> Signup and view all the answers

    What is the mode of action of Spectinomycin?

    <p>Inhibits protein synthesis by interfering with m-RNA interaction with the 30S ribosome</p> Signup and view all the answers

    What is the spectrum of activity of Chloramphenicol?

    <p>Broad-spectrum, effective against gram-positive and some gram-negative bacteria</p> Signup and view all the answers

    What is the mode of action of Macrolides?

    <p>Inhibits protein synthesis by binding to the 50S ribosome</p> Signup and view all the answers

    What is the mode of action of Rifampicin?

    <p>Inhibits RNA synthesis by binding to DNA-dependent RNA polymerase</p> Signup and view all the answers

    Which of the following antibiotics is effective against gram-positive cocci and urinary tract infections?

    <p>Quinolones</p> Signup and view all the answers

    What is the mode of action of sulfonamides?

    <p>They inhibit the synthesis of folic acid</p> Signup and view all the answers

    What is the mechanism of resistance to quinolones?

    <p>Decreased drug entry into bacterial cell due to alteration of membrane porin</p> Signup and view all the answers

    What is MRSA?

    <p>A type of pathogen that is resistant to methicillin and several other antibiotics</p> Signup and view all the answers

    Which enzyme catalyzes the formation of glycosidic bonds between the NAM and NAG of the peptidoglycan monomers and the NAG and NAM of the existing peptidoglycan?

    <p>Transglycosidase enzymes</p> Signup and view all the answers

    What is the role of bactoprenol in peptidoglycan synthesis?

    <p>Transport peptidoglycan monomers across the cytoplasmic membrane</p> Signup and view all the answers

    What is the function of autolysins in peptidoglycan synthesis?

    <p>Break the glycosidic bonds between the peptidoglycan monomers</p> Signup and view all the answers

    Which process of gene transfer requires the presence of a sex pilus on the donor cell?

    <p>Conjugation</p> Signup and view all the answers

    What is binary fission in bacteria?

    <p>The asexual process of reproduction involving cell division</p> Signup and view all the answers

    What is the optimal growth temperature range for mesophilic bacteria?

    <p>10 ° to 50 °</p> Signup and view all the answers

    Where are thermophilic bacteria commonly found?

    <p>In soils or waters associated with volcanic activities or exposed directly to the sun</p> Signup and view all the answers

    What is the mode of action of Rifampicin against bacteria?

    <p>Inhibits mRNA synthesis</p> Signup and view all the answers

    Which antibiotic is used in the treatment of penicillin-resistant Neisseria gonorrhoeae?

    <p>Spectinomycin</p> Signup and view all the answers

    What is the spectrum of activity of Fusidic acid?

    <p>Active against gram-positive cocci</p> Signup and view all the answers

    What is the common adverse effect of Tetracyclines?

    <p>Destruction of normal intestinal flora</p> Signup and view all the answers

    Which of the following is a virulence factor?

    <p>Products of bacterial metabolism</p> Signup and view all the answers

    What is the mechanism of adhesion for Pseudomonas aeruginosa?

    <p>Pili</p> Signup and view all the answers

    Which of the following bacteria has adhesion ability given by protein F and lipotheic acid?

    <p>Streptococcus pyogenes</p> Signup and view all the answers

    Which type of bacteria requires a large number of cells in the inoculum to successfully infect a host?

    <p>Vibrio cholerae</p> Signup and view all the answers

    What is the difference between an antibiotic and an antimicrobial agent?

    <p>Antibiotics kill microorganisms, while antimicrobial agents only inhibit their growth</p> Signup and view all the answers

    What is the target of Aminoglycosides?

    <p>Protein synthesis in 30S ribosome</p> Signup and view all the answers

    What is the minimum bactericidal concentration (MBC)?

    <p>The lowest concentration that kills 99.9% of the original inoculum</p> Signup and view all the answers

    What is the mode of action of quinolones?

    <p>They bind to the A subunit of DNA gyrase and prevent DNA synthesis</p> Signup and view all the answers

    Which type of bacteria are quinolones most effective against?

    <p>Gram-negative bacilli</p> Signup and view all the answers

    What is the mode of action of sulfonamides?

    <p>They competitively inhibit formation of dihydropteroic acid</p> Signup and view all the answers

    What is the primary mechanism of resistance to quinolones and sulfonamides?

    <p>Increased drug entry into bacterial cell due to alteration of membrane porin</p> Signup and view all the answers

    What is the mode of action of beta-lactam antibiotics?

    <p>Inhibition of cell wall synthesis</p> Signup and view all the answers

    What is the mechanism of resistance to beta-lactam antibiotics?

    <p>Enzymatic modification of the antibiotic</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>Inhibition of cell wall synthesis</p> Signup and view all the answers

    What is the mechanism of resistance to aminoglycoside antibiotics?

    <p>Enzymatic modification of the antibiotic</p> Signup and view all the answers

    What is the world's largest bacteria found in ocean sediments of the coast of Namibia?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which of the following bacterial species is NOT spherical (cocci)?

    <p>Escherichia coli</p> Signup and view all the answers

    What is the function of teichoic acids in the cell walls of gram-positive bacteria?

    <p>All of the above</p> Signup and view all the answers

    What is the difference between spirilla and spirochetes?

    <p>Spirilla are bend-shaped while spirochetes are cylindrical</p> Signup and view all the answers

    Which type of bacteria are penicillins most active against?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the mechanism by which bacteria become resistant to beta-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    What is the difference between cephalosporins and cephamycins?

    <p>Cephalosporins contain oxygen in place of sulfur in the dihydrothiazine ring while cephamycins contain sulfur</p> Signup and view all the answers

    What is the primary cause of antibiotic resistance according to the text?

    <p>Abuse of antibiotics in animals and foods</p> Signup and view all the answers

    What is the key difference between the cell walls of Gram-positive and Gram-negative bacteria?

    <p>Gram-negative bacteria have a periplasmic space containing enzymes</p> Signup and view all the answers

    What is Lipid A and how does it interact with the immune system?

    <p>It is the toxic part of LPS in Gram-negative bacteria and interacts with CD14 receptors on immune cells to induce inflammation</p> Signup and view all the answers

    What is the function of mycolic acids in the cell wall of Mycobacterium?

    <p>They are linked to peptidoglycans and form waxes that protect the bacteria from adverse conditions</p> Signup and view all the answers

    What is the mode of action of lysozyme in bacteria?

    <p>It degrades peptidoglycan in the cell wall</p> Signup and view all the answers

    What is the role of autolysins in peptidoglycan synthesis?

    <p>They break glycosidic bonds between peptidoglycan monomers and peptide cross-bridges</p> Signup and view all the answers

    What is the mechanism of action of vancomycin?

    <p>It binds to the peptides of the peptidoglycan monomers and blocks the formation of glycosidic bonds</p> Signup and view all the answers

    What is bacterial transformation?

    <p>The process of horizontal gene transfer by which some bacteria take up foreign genetic material from the environment</p> Signup and view all the answers

    What is the function of plasmids in bacteria?

    <p>To carry genes that encode toxins or proteins that promote the transfer of the plasmid to other cells</p> Signup and view all the answers

    What is the optimal temperature range for mesophilic bacteria?

    <p>Between 10°C and 50°C</p> Signup and view all the answers

    What is the temperature range for psychrophiles?

    <p>Between -5°C and 20°C</p> Signup and view all the answers

    What is the asexual process of reproduction in bacteria called?

    <p>Binary fission</p> Signup and view all the answers

    Which type of bacterial transfer is referred to as transduction?

    <p>Transfer of genes from one cell to another via a phage vector</p> Signup and view all the answers

    What is the mechanism of adhesion for Streptococcus pyogenes?

    <p>Adhesion to skin cell is mediated by protein F</p> Signup and view all the answers

    What is the function of virulence factors in bacteria?

    <p>To cause disease in the host</p> Signup and view all the answers

    What is the primary target of penicillin and other beta-lactam antibiotics?

    <p>Peptidoglycan synthesis</p> Signup and view all the answers

    Which of the following is a possible cause of antibiotic resistance?

    <p>Defective susceptibility assays</p> Signup and view all the answers

    Which of the following is a characteristic of carbapenems?

    <p>Very broad bacterial spectrum</p> Signup and view all the answers

    Which of the following is a mechanism of resistance to beta-lactam antibiotics in gram-negative bacteria?

    <p>Prevention of interaction with target PBP</p> Signup and view all the answers

    What is the target of Aminoglycosides like streptomycin and gentamicin?

    <p>Protein synthesis</p> Signup and view all the answers

    What is the minimum infective dose for enterohemorrhagic strains of Escherichia coli?

    <p>10 cells</p> Signup and view all the answers

    What is the principal mechanism of resistance to antibacterial drugs that involves rapid ejection of the drug?

    <p>Activation of efflux pumps</p> Signup and view all the answers

    What is the difference between antibiotics and antimicrobial agents?

    <p>Antibiotics kill microorganisms, while antimicrobial agents inhibit their growth</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space containing hydrolytic enzymes and lithic factors of infection?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    What is the endotoxin that characterizes the pathogenic feature of gram-negative bacteria?

    <p>Lipid A</p> Signup and view all the answers

    What is the primary function of mycolic acids in Mycobacterium?

    <p>To protect from disinfectants</p> Signup and view all the answers

    What is the primary function of peptidoglycan in bacteria?

    <p>To stabilize and compact the cell membrane</p> Signup and view all the answers

    Which of the following is the world's largest bacteria?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which of the following is NOT a method for classifying bacteria?

    <p>Gram-staining properties</p> Signup and view all the answers

    Which of the following is a characteristic of gram-positive bacteria?

    <p>The cell wall contains teichoic acids</p> Signup and view all the answers

    Which of the following is a characteristic of spiral-shaped bacteria?

    <p>They have a site for the anchorage and duplication of bacterial DNA called the mesosome</p> Signup and view all the answers

    What is the mode of action of quinolone antibiotics?

    <p>They prevent supercoiling of DNA, thereby inhibiting DNA synthesis</p> Signup and view all the answers

    What is the spectrum of activity of sulfonamide antimicrobials?

    <p>Broad range activity against gram-positive and gram-negative bacteria</p> Signup and view all the answers

    What is the mechanism of resistance to quinolone antibiotics?

    <p>Decreased drug entry into bacterial cell due to alteration of membrane porin</p> Signup and view all the answers

    What is MRSA?

    <p>A bacterium that is naturally resistant to methicillin antibiotics</p> Signup and view all the answers

    What is the mode of action of spectinomycin?

    <p>It reversibly interferes with m-RNA interaction with the 30S ribosome</p> Signup and view all the answers

    What is the spectrum of activity of chloramphenicol?

    <p>Broad-spectrum against gram positive and some gram negative bacteria</p> Signup and view all the answers

    What is the mode of action of macrolides?

    <p>They inhibit translocation</p> Signup and view all the answers

    What is the mode of action of rifampicin?

    <p>It inhibits initiation of mRNA synthesis by binding to DNA-dependent RNA polymerase</p> Signup and view all the answers

    Which enzyme is responsible for catalyzing the formation of glycosidic bonds between peptidoglycan monomers and the existing peptidoglycan?

    <p>Transglycosidase</p> Signup and view all the answers

    What is the process by which bacteria transfer genes from one cell to another by cell-to-cell contact?

    <p>Conjugation</p> Signup and view all the answers

    Which antibiotic is effective against Staphylococchi oxacillin-resistant and other gram+ resistant to beta-lactam antibiotics?

    <p>Vancomycin</p> Signup and view all the answers

    Which group of bacterial enzymes break the peptide cross-bridges that link the rows of sugars together in peptidoglycan synthesis?

    <p>Autolysins</p> Signup and view all the answers

    Which of the following is a mechanism of resistance to beta-lactam antibiotics?

    <p>Enzymatic modification of the antibiotic by phosphorylation</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>Interacts with D-alanine D-alanine terminal of lateral pentapeptidic chains</p> Signup and view all the answers

    What is the mechanism of action of aminoglycosides?

    <p>Binds to the 16S ribosomal RNA and freezes the 30S initiation complex</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors?

    <p>To bind and inactivate beta-lactamase</p> Signup and view all the answers

    Which of the following is NOT a step involved in bacterial growth via binary fission?

    <p>Formation of nucleolus</p> Signup and view all the answers

    Which type of bacteria lives at temperatures between -5°C and 20°C, and is responsible for the deterioration of chilled foods?

    <p>Psychrophiles</p> Signup and view all the answers

    Which type of bacteria lives at high temperatures between 45°C and 80°C, and is associated with volcanic activities or direct exposure to the sun?

    <p>Thermophiles</p> Signup and view all the answers

    Which bacteria is considered the world's largest?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which type of bacteria is responsible for causing gonorrhea?

    <p>Neisseria gonorrhoeae</p> Signup and view all the answers

    What is the function of teichoic acids in gram-positive bacteria?

    <p>They promote adhesion to target tissue</p> Signup and view all the answers

    What is the function of the mesosome in bacterial cells?

    <p>It is a site for bacterial DNA duplication</p> Signup and view all the answers

    Which of the following is a method of gene transfer in bacteria that occurs via a phage vector without cell-to-cell contact?

    <p>Transduction</p> Signup and view all the answers

    Which bacterial strain is able to adhere to skin cells via pili and produce an alginate mucous layer that allows it to anchor to cell surfaces, particularly in patients suffering from cystic fibrosis or other respiratory diseases?

    <p>Pseudomonas aeruginosa</p> Signup and view all the answers

    Which bacterial strain has adhesion ability given by protein F and lipotheic acid on its surface?

    <p>Streptococcus pyogenes</p> Signup and view all the answers

    Which of the following is NOT a mechanism of resistance to antibacterial drugs?

    <p>Increased susceptibility to antibiotics</p> Signup and view all the answers

    Which of the following is an example of an antimicrobial agent?

    <p>Chloramphenicol</p> Signup and view all the answers

    What is the minimum number of cells required for Vibrio cholerae to successfully infect a host?

    <p>Around 1000 cells</p> Signup and view all the answers

    What is the consequence of antibiotic treatment on the gastrointestinal tract?

    <p>Proliferation of antibiotic-resistant organisms</p> Signup and view all the answers

    Which type of bacteria has a periplasmic space containing enzymes such as protease, lipase, and phosphatase?

    <p>Gram-negative bacteria</p> Signup and view all the answers

    What is the function of Mycolic acids in Mycobacterium?

    <p>They allow bacterial survival in adverse conditions</p> Signup and view all the answers

    Which of the following is a characteristic of Gram-negative bacteria?

    <p>Allow passive diffusion of small hydrophobic molecules through porins</p> Signup and view all the answers

    What is the toxic part of LPS in Gram-negative bacteria?

    <p>Lipid A</p> Signup and view all the answers

    What is the mode of action of quinolones?

    <p>They bind to the A subunit of DNA gyrase and prevent supercoiling of DNA.</p> Signup and view all the answers

    What is the spectrum of activity of sulfamidics?

    <p>Broad range activity against gram-positive and gram-negative bacteria.</p> Signup and view all the answers

    What is the primary cause of antibiotic resistance in MRSA?

    <p>An alternative enzyme for folic acid synthesis encoded by a plasmid.</p> Signup and view all the answers

    What is the mode of action of trimethoprim against bacteria?

    <p>They bind to dihydrofolate reductase and inhibit formation of tetrahydrofolic acid.</p> Signup and view all the answers

    What is the primary difference between cephalosporins and cephamycins?

    <p>Cephalosporins contain sulfur in the dihydrothiazine ring while cephamycins contain oxygen.</p> Signup and view all the answers

    What is the primary mechanism by which bacteria become resistant to β-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP.</p> Signup and view all the answers

    Which of the following antibiotics is characterized by a rapid bactericidal action due to a faster crossing of porins D2 of the bacterial wall?

    <p>Carbapenems</p> Signup and view all the answers

    What is the primary reason for the emergence of bacterial resistance to penicillins?

    <p>Production of enzymes (penicillinases or β-lactamase) by bacteria.</p> Signup and view all the answers

    Which antibiotic is used primarily for the treatment of typhoid fever or bacterial meningitis due to its bone marrow toxicity?

    <p>Chloramphenicol</p> Signup and view all the answers

    Which antibiotic has a rare resistance in Neisseria gonorrhoeae and is used in the treatment of penicillin-resistant strains?

    <p>Spectinomycin</p> Signup and view all the answers

    Which antibiotic has a bactericidal effect and inhibits DNA-dependent RNA polymerase, making it most effective during cell division, and is used primarily in the treatment of tuberculosis?

    <p>Rifampicin</p> Signup and view all the answers

    Which antibiotic has a mode of action that involves inhibiting translocation, is broad-spectrum against gram positive and some gram negative bacteria, and has common resistance?

    <p>Macrolides</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>It inhibits proper cell wall synthesis in gram-positive bacteria</p> Signup and view all the answers

    What is the mechanism of resistance to aminoglycoside antibiotics?

    <p>Mutations in the binding site to the ribosome</p> Signup and view all the answers

    What is the spectrum of activity of aminoglycosides?

    <p>Many gram-negative and some gram-positive bacteria</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors like clavulanic acid and sulbactam?

    <p>They bind and inactivate beta-lactamase and allow penicillins to enter the bacterial cell without undergoing enzymatic degradation</p> Signup and view all the answers

    Which enzyme catalyzes the formation of glycosidic bonds between the NAM and NAG of the peptidoglycan monomers and the NAG and NAM of the existing peptidoglycan?

    <p>Transglycosidase</p> Signup and view all the answers

    What is the function of the capsule in many bacteria?

    <p>It allows adherence to the tissue and protects bacteria from phagocytosis.</p> Signup and view all the answers

    What is the mechanism of action of vancomycin against Staphylococchi oxacillin-resistant and other gram+ bacteria?

    <p>It binds the peptides of the peptidoglycan monomers and blocks the formation of glycosidic bonds between the sugars by the transglycosidase enzymes.</p> Signup and view all the answers

    What is the process of bacterial transformation?

    <p>It is a process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment.</p> Signup and view all the answers

    Which of the following is NOT involved in bacterial growth through binary fission?

    <p>Formation of cilia for cell movement</p> Signup and view all the answers

    Which type of bacteria is responsible for the deterioration of chilled foods?

    <p>Psychrophiles</p> Signup and view all the answers

    Which of the following temperature ranges is optimal for mesophilic bacteria growth?

    <p>10 ° to 50 °</p> Signup and view all the answers

    Which of the following is a virulence factor of Pseudomonas aeruginosa?

    <p>Pili</p> Signup and view all the answers

    What is transduction in bacterial genetics?

    <p>The transfer of genes from one cell to another via a phage vector without cell-to-cell contact</p> Signup and view all the answers

    Which of the following is a virulence factor of Streptococcus pyogenes?

    <p>Protein F</p> Signup and view all the answers

    What is the minimum infective dose required for enterohemorrhagic strains of Escherichia coli to begin an infection?

    <p>Less than 10 cells</p> Signup and view all the answers

    What is the lowest concentration that kills 99.9% of the original inoculum in antibiotic susceptibility testing?

    <p>Minimum bactericidal concentration (MBC)</p> Signup and view all the answers

    What is the primary mechanism of resistance to antibacterial drugs that involves enzymatic drug destruction or inactivation?

    <p>Enzymatic drug destruction or inactivation</p> Signup and view all the answers

    What is the consequence of antibiotic treatment on the most common microbes that colonize the gastrointestinal tract?

    <p>They can cause the proliferation of antibiotic-resistant organisms</p> Signup and view all the answers

    Which of the following bacterial cell wall components is absent in Gram-negative bacteria?

    <p>Teichoic acids</p> Signup and view all the answers

    What is the function of waxes in the cell wall structure of Mycobacteria?

    <p>To protect from drying and disinfectants</p> Signup and view all the answers

    What is the toxic part of LPS in Gram-negative bacteria?

    <p>Lipid A</p> Signup and view all the answers

    What is the mode of action of beta-lactamase enzymes?

    <p>To disrupt antibiotics and make bacteria resistant to the drug</p> Signup and view all the answers

    Which group of bacteria is penicillin most active against?

    <p>Gram-positive bacteria</p> Signup and view all the answers

    What is the mechanism by which bacteria can become resistant to beta-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    Which of the following is a characteristic of carbapenems?

    <p>Very broad bacterial spectrum</p> Signup and view all the answers

    What is the difference between cephalosporins and cephamycins?

    <p>Cephamycins contain oxygen in place of sulfur in the dihydrothiazine ring</p> Signup and view all the answers

    What is the mode of action of chloramphenicol?

    <p>It binds the 50S ribosome and blocks the peptide extension.</p> Signup and view all the answers

    What is the spectrum of activity of tetracyclines?

    <p>Broad-spectrum against gram positive and some gram negative bacteria.</p> Signup and view all the answers

    What is the mode of action of macrolides?

    <p>They reversibly interfere with m-RNA interaction with the 30S ribosome.</p> Signup and view all the answers

    What is the mode of action of rifampicin?

    <p>It binds to DNA-dependent RNA polymerase and inhibits initiation of mRNA synthesis.</p> Signup and view all the answers

    Which of the following antibiotics inhibits DNA synthesis by binding to the A subunit of DNA gyrase in gram-negative bacteria?

    <p>Quinolones</p> Signup and view all the answers

    Which of the following antimetabolite antimicrobials inhibits the synthesis of folic acid by binding the enzyme involved in folic acid synthesis in place of the natural substrate (PABA)?

    <p>Sulfamidics</p> Signup and view all the answers

    What is the mechanism of action of trimethoprim, methotrexate, and pyrimethamine?

    <p>Inhibition of folic acid synthesis</p> Signup and view all the answers

    What is MRSA?

    <p>A type of gram-positive bacteria</p> Signup and view all the answers

    Which of the following is the world's largest bacteria?

    <p>Thiomargarita namibiensis</p> Signup and view all the answers

    Which of the following is a characteristic of gram-positive bacteria?

    <p>The cell wall contains teichoic acids</p> Signup and view all the answers

    Which of the following is NOT a characteristic used to classify bacteria?

    <p>Antibiotic resistance</p> Signup and view all the answers

    What is the difference between spiral and cylindrical/rod-shaped bacteria?

    <p>Spiral bacteria have a bend shape, while cylindrical/rod-shaped bacteria are straight</p> Signup and view all the answers

    Which enzyme catalyzes the formation of glycosidic bonds between the NAM and NAG of the peptidoglycan monomers and the NAG and NAM of the existing peptidoglycan?

    <p>Transglycosidase</p> Signup and view all the answers

    What is the function of bactoprenol in peptidoglycan synthesis?

    <p>Transport peptidoglycan monomers across the cytoplasmic membrane</p> Signup and view all the answers

    What is the mode of action of Vancomycin?

    <p>It binds the peptides of the peptidoglycan monomers and blocks the formation of glycosidic bonds between the sugars</p> Signup and view all the answers

    What is the process of bacterial transformation?

    <p>Horizontal gene transfer by which some bacteria take up foreign genetic material from the environment</p> Signup and view all the answers

    What is the mode of action of vancomycin?

    <p>It inhibits proper cell wall synthesis in Gram-positive bacteria by interacting with D-alanine D-alanine terminal of lateral pentapeptidic chains interfering with the formation of bridges.</p> Signup and view all the answers

    What is the main mechanism of resistance to beta-lactam antibiotics?

    <p>Mutations in the PBPs that do not allow the binding with the antibiotic.</p> Signup and view all the answers

    What is the mode of action of aminoglycosides?

    <p>They irreversibly bind to the 16S ribosomal RNA and freeze the 30S initiation complex (30SmRNA-tRNA) so that no further initiation can occur. They also slow down protein synthesis that has already initiated and induce misreading of the mRNA.</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors such as clavulanic acid and sulbactam?

    <p>They bind and inactivate beta-lactamase and allow Penicillins to enter the bacterial cell without undergoing enzymatic degradation.</p> Signup and view all the answers

    Which of the following is NOT a characteristic of mesophilic bacteria?

    <p>They can survive in cold environments.</p> Signup and view all the answers

    What is the temperature range for hyperthermophiles?

    <p>Between 80°C and 115°C.</p> Signup and view all the answers

    Which type of bacteria are responsible for the deterioration of chilled foods?

    <p>Psychrophiles</p> Signup and view all the answers

    What is the target of Aminoglycosides?

    <p>Protein synthesis</p> Signup and view all the answers

    What is the difference between Antibiotics and Antimicrobial agents?

    <p>Antibiotics inhibit growth while Antimicrobial agents kill microbes</p> Signup and view all the answers

    What is the Minimum Inhibitory Concentration (MIC)?

    <p>The lowest concentration that results in inhibition of visible growth</p> Signup and view all the answers

    What is the primary cause of the proliferation of antibiotic-resistant organisms?

    <p>Antibiotic treatment</p> Signup and view all the answers

    Which type of antibiotic inhibits DNA synthesis by binding to the A subunit of DNA gyrase in bacteria?

    <p>Quinolones</p> Signup and view all the answers

    Which type of bacteria are naturally resistant to hydrophobic antibiotics due to their external wall?

    <p>Gram-negative</p> Signup and view all the answers

    Which type of antimicrobial inhibits the synthesis of folic acid in bacteria by binding to the enzyme involved in the process?

    <p>Sulfamidics</p> Signup and view all the answers

    What is the mode of action of trimethoprim, methotrexate, and pyrimethamine in bacteria?

    <p>Inhibition of folic acid synthesis</p> Signup and view all the answers

    What is the primary cause of antibiotic resistance due to heavy use of penicillin?

    <p>Production of enzymes by bacteria</p> Signup and view all the answers

    Which type of bacteria are penicillins most active against?

    <p>Spirochetes</p> Signup and view all the answers

    Which antibiotics are known to cause antagonism when used together?

    <p>Penicillins and aminoglycosides</p> Signup and view all the answers

    What is the primary mechanism by which bacteria become resistant to β-lactam antibiotics?

    <p>Prevention of the interaction between the antibiotic and the target PBP</p> Signup and view all the answers

    What is transduction in bacteria?

    <p>Transfer of genes from one cell to another via a phage vector without cell-to-cell contact</p> Signup and view all the answers

    What is the function of virulence factors in bacteria?

    <p>They are constituents of the bacterial cell or products of bacterial metabolism that aid in causing disease</p> Signup and view all the answers

    How does Pseudomonas aeruginosa adhere to skin cells?

    <p>Adhesion is mediated by pili and an alginate mucous layer</p> Signup and view all the answers

    Which enzyme is responsible for breaking the glycosidic bonds between the peptidoglycan monomers at the point of growth along the existing peptidoglycan?

    <p>Autolysins</p> Signup and view all the answers

    What is the process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment?

    <p>Transformation</p> Signup and view all the answers

    What is the mechanism of action of vancomycin against bacteria?

    <p>It blocks the formation of glycosidic bonds between the NAM and NAG of the peptidoglycan monomers</p> Signup and view all the answers

    Which type of bacteria does not have peptidoglycan?

    <p>Mycoplasma</p> Signup and view all the answers

    What is the mode of action of spectinomycin?

    <p>It reversibly interferes with m-RNA interaction with the 30S ribosome.</p> Signup and view all the answers

    What is the spectrum of activity of chloramphenicol?

    <p>Broad-spectrum against gram positive and some gram negative bacteria.</p> Signup and view all the answers

    What is the mode of action of macrolides?

    <p>It inhibits translocation.</p> Signup and view all the answers

    What is the mode of action of rifampicin?

    <p>It inhibits initiation of mRNA synthesis by binding to DNA-dependent RNA polymerase.</p> Signup and view all the answers

    Which of the following is NOT a characteristic used to classify bacteria?

    <p>Color</p> Signup and view all the answers

    Which of the following bacterial species is NOT cylindrical/rod-shaped?

    <p>Streptococcus pneumoniae</p> Signup and view all the answers

    Which of the following is a characteristic of gram-positive bacteria?

    <p>Cell wall composed of peptidoglycan</p> Signup and view all the answers

    What is the function of the mesosome in bacteria?

    <p>Portion of the cytoplasmic membrane invaginations</p> Signup and view all the answers

    What is the main difference between the cell walls of Gram-positive and Gram-negative bacteria?

    <p>Gram-positive bacteria have teichoic and lypoteichoic acids, while Gram-negative bacteria do not.</p> Signup and view all the answers

    What is the function of Lipid A in Gram-negative bacteria?

    <p>It is the toxic part of LPS and promotes the release of acute phase cytokines, inducing inflammation.</p> Signup and view all the answers

    What is the role of mycolic acids in Mycobacterium?

    <p>They are linked to peptidoglycans through a bridge of arabinogalactans and can bind different glycolipids, forming waxes that protect the bacteria from drying and disinfectants.</p> Signup and view all the answers

    What is the primary staining agent used in Gram staining?

    <p>Crystal violet</p> Signup and view all the answers

    What is the mode of action of Vancomycin?

    <p>It interacts with D-alanine D-alanine terminal of lateral pentapeptidic chains interfering with the formation of bridges.</p> Signup and view all the answers

    What is the mechanism of resistance to beta-lactam antibiotics?

    <p>Mutations in the PBPs that do not allow binding with the antibiotic.</p> Signup and view all the answers

    What is the mode of action of aminoglycosides?

    <p>They irreversibly bind to the 16S ribosomal RNA and freeze the 30S initiation complex.</p> Signup and view all the answers

    What is the function of beta-lactamase inhibitors such as clavulanic acid and sulbactam?

    <p>They allow Penicillins to enter the bacterial cell without undergoing enzymatic degradation.</p> Signup and view all the answers

    Study Notes

    Bacterial Reproduction

    • Binary fission is the common process of reproduction in most bacteria.

    Bacterial Temperature Ranges

    • Psychrophiles have a temperature range of 0-10°C and an optimal temperature of 2-5°C.
    • Thermophiles have a temperature range of 50-80°C and are associated with volcanic activities or exposed directly to the sun.

    Antibiotics

    • Aminoglycosides target the 30S ribosomal subunit.
    • The minimum inhibitory concentration (MIC) is the lowest concentration of an antibiotic that kills 99.9% of the original inoculum in vitro.
    • Quinolones target the enzyme DNA gyrase.
    • Sulfamidics are effective against Gram-positive bacteria.
    • Vancomycin targets the peptidoglycan layer of the bacterial cell wall.
    • Beta-lactamase inhibitors, such as clavulanic acid and sulbactam, inhibit the action of beta-lactamase enzymes.

    Bacterial Structure and Function

    • Mesosomes are cell membrane infoldings that increase the surface area for cellular respiration.
    • The Gram-negative bacterial cell wall contains Lipid A, which induces inflammation.
    • Peptidoglycan is a key component of bacterial cell walls that provides structural support.
    • Transglycosidase enzymes catalyze the formation of glycosidic bonds between peptidoglycan monomers.
    • Bactoprenol is a carrier lipid that plays a role in peptidoglycan synthesis.

    Bacterial Infections and Resistance

    • MRSA (Methicillin-resistant Staphylococcus aureus) is a type of antibiotic-resistant bacteria.
    • The primary cause of antibiotic resistance is the overuse and misuse of antibiotics.
    • Beta-lactamase production is a mechanism of resistance to beta-lactam antibiotics.
    • Aminoglycoside resistance can occur due to mutations in the ribosomal binding site.

    Other Bacterial Facts

    • Thiomargarita namibiensis is a type of bacteria that produces sulfur compounds.
    • Streptococcus pyogenes has a M protein that gives it adhesion ability.
    • Some bacteria have teichoic acids in their cell walls, which promote adhesion to target tissue and have antigenic properties.
    • Some bacteria have a spiral form and a cell membrane without sterols, but with terpenoids that stabilize and compact it.

    Virulence Factors

    • Virulence factors are molecules that contribute to the pathogenicity of bacteria.
    • Examples of virulence factors include protein F and lipotheic acid in Streptococcus pyogenes.

    Horizontal Gene Transfer

    • Conjugation is the process of horizontal gene transfer by which bacteria transfer genes from one cell to another through direct cell-to-cell contact.
    • Transformation is the process of horizontal gene transfer by which some bacteria take up foreign genetic material (naked DNA) from the environment.

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    Description

    Test your knowledge on peptidoglycan synthesis and cell division machinery in bacteria with this quiz! Learn about the role of bactoprenol in transporting peptidoglycan monomers and how new peptidoglycan is synthesized at the cell division plane. Keywords: peptidoglycan, bactoprenol, cytoplasmic membrane, cell division machinery.

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