General Biofilms Flashcards
1
Q
- What is a biofilm?
A
a. A biofilm is a structured community of bacterial cells enclosed in a self-produced extracellular polymeric matrix (EPS) and adherent to inert or living surfaces (Costerton, 1999).
2
Q
- The Pseudomonas fluorescens biofilms that grow on the surface of plant roots prevent the growth of ______ pathogens.
A
a. Fungal
3
Q
- Biofilms that grow on ingested plant material within the _____aid efficient breakdown of the plant which in turn provides the ruminant with energy which is converted to meat and milk.
A
a. Rumen
4
Q
- What are the five stages of biofilm formation?
A
a. (1) Initial attachment
b. (2 Genetic changes and production of EPS
c. (3) Early development
d. (4) Maturation
e. (5) Dispersion
5
Q
- What factors affect the attachment phase?
A
a. Physiochemical properties of a surface affect colonisation
b. Surface texture and roughness
c. Electrostatic charge
d. Surface free energy
e. Hydrophobicity
f. The presence of a conditioning film
6
Q
- In most biofilms the microbial cells account for approx. ______of the biomass with EPS constituting ______ (Flemming and Wingender, 2010)
A
a. 10%
b. 90%
7
Q
- Attrachtion to surfaces occurs initially from what type of forces for motile bacteria?
A
a. Van der Waals
8
Q
- What way do non-motile bacteria end up in biofilms initially?
A
a. Random
9
Q
- What is the second stage of attachment of a cell decides not to leave?
A
a. Irreversible attachment
10
Q
- Once the cells dcide to for the biofilm what happens next?
A
a. Growth and division
11
Q
- Biofilms will split up into sections to increase surface area in what type of environment?
A
a. Aquatic
12
Q
- When there are too many microbes in they will ______?
A
a. Disperse
13
Q
- The dispersed cell from a biofilm can do two things what are they?
A
a. Go on to form another biofilm
b. Be broke down in the rumen to provide proteins and nutrients
14
Q
- What surfaces are more likely to get biofilms? And Why?
A
a. Rough, indents etc, as its protected
15
Q
- What is a conditioning film? Why is this important?
A
a. surface coatings formed by the adsorption of biomolecules from the surrounding environment that can modify the material-specific surface properties and precedes the attachment of microorganisms.
16
Q
- EPS composed mainly of______, proteins, DNA and lipids (proportions differ dependent of environment)– up-regulation, lysis and membrane vesicles (Flemming and Wingender, 2010)
A
a. Polysaccharides
17
Q
- What is the Main component of most EPS matrices (approx . 50%)
A
a. Polysaccharides
18
Q
- What are the majority of the polysaccharides in the EPS?
A
a. Heteropolysaccharides
19
Q
- Pseudomonas aeruginosa up-regulates alginate release to the EPS? What is it?
A
a. Alginate
b. Heteropolysaccharides
20
Q
- Pseudomonas aeruginosa known to actively release ‘unwanted’ non-coding _____or ______ to the EPS within blebbed ______vesicles (Schooling et al., 2006)
A
a. DNA
b. enzymes
c. membrane
21
Q
- The _____ and _______in membrane vesicle s keep a structure to the EPS.
A
a. DNA
b. Proteins
22
Q
- Enzymes – many extracellular enzymes involved in degradation of biopolymers found in EPS. These are usually released extracellularly by the attached _______although some are a product of cell______.
A
a. Bacteria
b. Lysis
23
Q
- Structural proteins – Non-enzymatic proteins are involved in stabilization of the EPS matrix e.g’s include_______. Present due to cell lysis
A
a. Lectin
24
Q
- Treatment of Rhodovulum spp. biofilms with nucleolytic enzymes – biofilm dispersion. Polysaccharide and protein-degrading enzymes had no effect. (T/F)
A
a. True
25
25. What protection does the biofilm give you?
a. Antibiotics
b. Toxins
c. Antibodies
d. phage attack
e. predation by protozoa
26
26. How are nutrient provided in a biofilm?
a. Trace organics will concentrate on surfaces
b. Extracellular polymers will further concentrate trace nutrients from bulk water
c. Secondary colonizers utilize the waste products from their neighbours
d. Bacteria armed with enzymes can break down food supplies that single species could alone
27
27. How is stability provided in a biofilm?
a. DNA and prtien and the polysaccharides
b. But have the ability to leave
28
28. How does community aid a biofilm?
a. Gene transfer
b. signal transduction
c. quorum sensing
29
29. Cells within biofilms are reported to be _________ times more resistant to antimicrobials than planktonic cells.
a. 10-1000
30
30. Why are biofilms able to develop antimicrobial resistance?
a. Diffusion limitation
b. Generation time
c. Efflux pumps
d. Clonal expansion of pre-existing, resistant mutants
31
31. E. colii describe:
a. Graham negative
b. Motile: Petritrichous flagella arrangement.
32
32. What part of E. coli is vital for biofilm formation? When E. coli had a muttion in the flagella how does this affect the biofilm?
a. Flagellar active movement vital for biofilm formation
b. Flagella – mutants = little biofilm formation
33
33. Cyclic-diguanylic acid (c-di-GMP) play a big role in shifting to \_\_\_\_\_\_state, through \_\_\_\_\_\_
a. Sessile
b. Upregulation
34
34. Irreversible attachment involve attachment using fimbriae? Stay? Leave?
a. Make a strong attachment
35
35. Type 1 Fimbriae is encoded by ______ gene found in the majority of _______ serovars.
a. Fim
b. E, coli
36
36. What is the diameter, lengths, and number of fimbriae of Type 1, on E. coli?
a. 5-7nm diameter and 0.2-2m long; typically 100-500
37
37. Mutants –\_\_\_\_\_and ____ reduced attachment and thus biofilm formation
a. fimA
b. fimH
38
38. ______ are important for the initial attachment, and then ____ are responsible of the irreversible attachment
a. Flagella
b. Fimbria
39
39. _________ (also called thin aggregated fimbriae). Encoded by? Aggregate to form? Specific to?
a. Curli Fimbriae
b. csg gene
c. Aggregate to form 6-12 nm diameter structures between 0.5-1µm in length
d. Fibronectin
40
40. The _____ pilus encoded by the \_\_\_\_\_locus within conjugative plasmids involved in initial attachment and biofilm maturation through non-specific attachment to \_\_\_\_\_surfaces.
a. F
b. Tra
c. Abiotic
41
41. Two component regulatory cpx\_\_\_\_\_ system composed of sensor membrane protein ____ and cytoplasmic regulator \_\_\_\_.
a. RA
b. CpxA
c. CpxR
42
42. What is the importance of cpx system for sensing of surfaces?
a. Involved in bacterial adaptation to environmental stress
b. Up-regulated during E.coli adhesion to abiotic surfaces
c. Sensing surface for stress
43
43. cpxR E. coli mutations alter cell surface _______ system composed of sensor membrane protein CpxA and cytoplasmic regulator CpxR
a. interactions
44
44. Type V secretion pathways involved in _________ make up?
a. EPS
45
45. What are the three most common EPS polysaccharides in the E. colu EPAS? And their encoding operons?
a. Poly-β-1,6-N-acetyl glucosamine (PGA) – encoded by pgaABCD operon
b. Cellulose synthase encoded by bcsABZC operon
c. Colanic acid – negatively charged polymer of glucose, galactose, fructose and glucuronic acid that forms protective capsule around bacterium.
46
46. The ______ system mediates biofilm maturation
a. Rcs
47
47. rcs two-component system composed of membrane –associated proteins\_\_\_\_ and \_\_\_\_and the cytoplasmic response regulator \_\_\_\_
a. RcsC
b. RcsD
c. RcsB
48
48. RcsC sensor \_\_\_\_\_\_responds to growth on a solid surface and is thus required for normal biofilm development in E. coli. Also regulates cps operon encoding proteins required for capsular colanic acid production
a. Kinase
49
49. What is the importance of quorum sensing in biofilms?
a. Quorum sensing is a density-dependent mechanism allowing bacteria to co-ordinate their gene expression.
50
50. When is a biolfilm classed as high density?
a. 108
51
1. E. coli possess \_\_\_\_\_\_\_and \_\_\_\_\_\_\_\_based quorum sensing capacity
1. autoinducer-2 (AI-2)
2. acyl-homoserine lactone (AHL)
52
SdiA upregulates \_\_\_\_\_and\_\_\_ genes which enhance the capacity for biofilm formation
1. ydiV
2. csrA
53
1. AI-2 based QS responsible for \_\_\_\_and \_\_\_\_\_-species bacterial communication. AI-2 QS known to increase biofilm biomass
1. Inter
2. Intra
54
1. Glucose can result in the upregulation of Al-2. T/F
1. F
55
1. _________ protein identified to play a role in some E. coli biofim dispersion events (Velarde et al., 2007). But little is known
1. Dispersin
56
Dispersin plasmid encoded (\_\_\_\_\_\_gene)
1. Aap
57
1. What does dispersin do?
1. Prevents electrostatic surface interactions involving curli fimbriae
58
1. The gene _____ (also referred to as yjgI) decreases extracellular polysaccharide (EPS) production by decreasing \_\_\_\_\_\_\_concentrations, and consequently biofilm dispersal. The _____ knockout decreases biofilm dispersal
1. bdcA
2. c-di-GMP
3. bdcA
59
1. Again Cyclic-diguanylic acid (c-di-GMP) play a big role in shifting to sessile state is important for both E. coli and Pseudomonas aeruginosa. (T/F)
1. True
60
1. What is the Pseudomonas aeruginosa?
1. Flagella
2. Typ[e iV pili
3. Extracellualr DNA priducation
4. Psl polysaccharide
61
1. IV pili is coded by?
1. pilB gene
62
1. pilB mutant P. aeruginosa unable to produce ______ is compromised in terms of ability to form biofilms.
1. Pili
63
1. \_\_\_\_\_\_\_mutant P. aeruginosa unable to produce flagella is compromised in terms of ability to form biofilms.
1. flgK
64
1. P. aeruginosa biofilm matrix production. Mainly polysaccharide (\_\_\_\_\_\_\_), proteins and nucleic acids.
1. Alginate
65
1. Alginate is an \_\_\_\_\_\_\_polysaccharide composed of β-1,4-linked L-guluronic and D-mannuronic acids
1. Acetylated
66
1. Alginate produced by P. aeruginosa in lung infections and ______ patients.
1. Cystic Fibrosis
67
1. \_\_\_\_\_\_\_used as slimming aids, manufacture of paper and textiles, gelling agent, etc.
1. Alginate
68
1. \_\_\_\_\_\_\_overproducing P. aeruginosa biofilms highly structured and significantly more resistant to antimicrobials
1. Alginate
69
1. Alginate lyase treatment enhances susceptibility to \_\_\_\_\_\_– Alginate physical barrier to antimicrobials
1. Antimicrobials
70
1. \_\_\_\_\_treatment disrupts P. aeruginosa biofilms
1. DNAse
71
1. Both LasI and RhlI are \_\_\_\_\_\_working in tandem
1. autoinducers
72
1. ______ encodes 3-oxohexanoyl-L-homoserine lactone (OHHL)
1. LasI
73
1. ______ encodes N-(butryl)-homoserine lactone
1. RhlI
74
1. LasR binds OHHL and together they bind to \_\_\_\_\_\_\_region allowing the transcription of a cascade of virulence factors (elastase encoded by lasB, protease encoded by lasA, exotoxin A encoded by toxA and alkaline phosphatase encoded by aprA)
1. Promoter
75
1. LasR bound to autoinducer also stimulates \_\_\_\_\_\_\_expression establishing a positive feedback loop
1. LasI
76
1. \_\_\_\_\_\_autoinducer complex also stimulates expression of rhlR. RhlR binds N-(butryl)-homoserine lactone produced by RhlI causing induction of lasB (elastase) and aprA (alkaline phosphatase)
1. LasR
77
1. RhlR autoinducer complex alo induce transcription of a second group of specific genes: (5)
1. rpoS – encodes stationary phase sigma factor
2. rhlAB – encodes rhamnosyltransferase (rhamnolipid production)
3. Genes encoding pyocynain antibiotic production
4. lecA – encodes a cytotoxic lectin
5. RhlI – autoregulatory feedback loop
78
1. What is PQS:
1. P. aeruginosa quinolone signal
79
1. \_\_\_\_\_\_\_also partially controls lasB (elastase production) (alongside LasR and Rhl quorum sensing systems).
1. PQS
80
1. PQS enhances ______ release and therefore biofilm stability
1. eDNA
81
1. \_\_\_\_\_lipids play a role in the architechture of P. aeruginosa biofilms
1. Rhamnolipids
82
1. Dispersal of P. aeruginosa biofilms: Three factors?
1. Rhamnolipid
2. Cis-2 decanoic acid
3. Alginate lyase encoded by algL, degrades aliginate in EPS
83
1. What is S. aureus?
1. Gram positive cocci
2. Cluster into ‘grape-like’ structures
3. Non-motile
4. Facultative anaerobes
84
1. S. aureus biofilm attachment via \_\_\_\_\_\_\_\_\_(CWA) proteins specific for different host matrix substrates
1. cell wall-anchored
85
1. cell wall-anchored (CWA) proteins Mostly consist of the \_\_\_\_\_\_\_\_\_\_\_(MSCRAMMs), several of which share a common cell wall targeting motif, but have different binding specificities for host matrix components, such as fibronectin, fibrinogen, collagen and cytokeratin
1. microbial surface components recognizing adhesive matrix molecules
86
S. aureus biofilm attachment and maturation is dependent on _____ based quorum sensing.
1. AGR
87
1. Other cell-wall anchored (CWA) proteins categorized as MSCRAMMs like the FnBPs, ClfB and SdrC proteins, play dual roles in both ______ and\_\_\_\_\_\_\_\_.
1. Attachment
2. Accumulation
88
1. CWA proteins such as the Staphylococcus ________ (Aap) and the S. aureus homolog, SasG have also been implicated in attachment and early accumulation.
1. accumulation-associated protein
89
1. In addition, CWA proteins, like Protein A, SasC and Bap have all shown a propensity to aid in biofilm\_\_\_\_\_\_.
1. accumulation
90
1. _______ and _______ promote S. aureus biofilm stability
1. eDNA
2. autolysis
91
1. Degradation of \_\_\_\_\_within the biofilm matrix by a self-produced, secreted nuclease has repeatedly been shown to reduce the total biomass of S. aureus biofilms
1. eDNA
92
1. Dispersal of S. aureus biofilms has largely been shown to be under the control of ______ quorum sensing
1. Agr
93
1. In S. aureus biofilms, an octapeptide pheromone called \_\_\_\_\_\_\_(AIP) accumulates and activates ______ kinase, AgrC. AgrC then phosphorylates the response regulator, AgrA, which initiates transcription from the P3 promoter of the agr operon, producing a regulatory RNA molecule (RNAIII) that regulates biofilm-associated genes.
1. auto-inducing peptide
2. histidine
