Infectious Diseases E2 L13

Front 1

_________ are longer than _________ and there are only a few per cell. They are used for gene transfer between cells (found only in gram-_________ bacteria and not restriced to species), while _________ are mainly for attachment to surfaces such as the epithelial cells of the mucosa.

Back 1

Pili

fimbriae

negative

fimbriae

Front 2

_________ involves a process called conjugation where a "sex" pilus (or F-pilus) extends from a donor bacterium (F+) to a recepient (F-). A copy of part of the donor bacterium's genome then passes along the pilus into the recipient cell. The passed DNA may code for _________ which explains the abundance of _________ bacteria.

Back 2

Gene transfer

drug resistance

drug-resistant

Front 3

Pili are also involved in _________ motility.

Back 3

twitching

Front 4

Located as a shell of the cell envelope, the glycocalyx is a coat of either _________ or _________.

Back 4

slime layer

capsule

Front 5

The _________ is loosely bound to the cell and serves to protect the cell against dehydration and also as a food source (composed of polysaccharide matter with or without proteins).

Back 5

slime layer

Front 6

A _________ is composed of polysaccharide matter with or without proteins BUT it tends to be strongly bound to the cell. Colonies of cells possessing _________ are characteristically mucoid in nature.

Back 6

capsule

capsules

Front 7

The capsule protects the organism against _________ by white blood cells, an important immune defence mechanism without which we would become vulnerable to infection. Therefore, the presence of a capsule is often an indicator of virulence and the capsule itself is considered to be a _________.

Back 7

phagocytosis

virulence factor

Front 8

The slime layer and capsule are in contrast to _________, which is secreted and makes up the matrix.

Back 8

exopolysaccharide

Front 9

_________ is a gram-negative anaerobic bacterium that inhabits the oral cavity and is linked to severe periodontal disease. It is non-motile.

Back 9

Porphyromonas gingivalis

Front 10

_________ (a surfactant) synthesis is required for normal Pseudomonas aeruginosa biofilm architecture.

Back 10

Rhamnolipid

Front 11

Both _________ and _________ cell systems are used to study biofilm formation.

Back 11

static

flow

Front 12

_________ strains can be used to identify pathways for biofilm development.

Back 12

Mutant

Front 13

As bacteria grow on surfaces in the oral cavity, they _________ the environment around them.

Back 13

modify

Front 14

_________ between genetically distinct species (co-aggregation) is the foundation of plaque formation.

Back 14

Direct contact

Front 15

_________ and _________ are two key mechanisms involved in plaque development.

Back 15

Co-aggregation

succession

Front 16

In order for target genes to turn on and quorum sensing to occur, the bacteria must be in high _________.

Back 16

density

Front 17

The autoinducers ________ are produced by gram-negative bacteria. These are ________ cell-density dependent signals important for biofilm development.

Back 17

acyl-homoserine lactones (AHL)

diffusible

Front 18

Gram-positive bacteria have a different system for cell-dependent signaling which consists of ________ that are processed and transported to turn certain genes on.

Back 18

peptides

Front 19

During the early stages of plaque development, Streptococci constitute up to ________% of supragingival plaque.

Back 19

70

Front 20

________ associated with extracellular DNA in the matrix of a biofilm are being targeted to combat biofilm based infections.

Back 20

DNA binding proteins (DBPs)

Front 21

The process of successive biofilm formation involves ________ inhibition, ________ inhibition, ________ pathways, action on the ________, and fighting ________.

Back 21

non-specific

specific

signaling

matrix

persisters