Bacteriology 2/3

Question 1

host

Answer 1

any organism that supports the survival and growth of microorganisms (parasites,bacteria, virus)

Question 2

saprophyte

Answer 2

are organisms that live on dead or decaying organic matter
usually not parasites of animals but can occasionally live in/on animals and cause disease

Question 3

parasite

Answer 3

general term that denotes an organism that lives on or within another living organism and derives sustenance
parasite does not necessarily harm the host but has the ability to given the right circumstances

Question 4

commensal

Answer 4

organism that lives in/on the host without causing disease
most of the bacteria that normally live in the intestines on the skin and on mucous membranes

Question 5

pathogen

Answer 5

parasitic and saprophytic bacteria which have the potential to cause disease
dont always cause disease but become pathogenic under conditions where host animals or their tissues allow invasion and disease production
live on the host as part of the normal flora
or live in only a porprotion of animals in a population

Question 6

carriers

Answer 6

animals with specific bacterial pathogens that is present in fewer animals within a population
pathogens may be causing subclinical disease or no clinical disease at all but still shed pathogen

Question 7

most animals-normal flora

Answer 7

cant eliminate a bacterial pathogen from the animal population

Question 8

few animals=carrier animals

Answer 8

can eliminate a bacterial pathogen from the animal population

Question 9

Skin

Answer 9

NF-all over
heavy bacteria in skin folds

Question 10

Ear

Answer 10

NF-ear flap, vertical canal, horizontal canal
sterile-after tympanic membrane (Ear drum)
gram + and yeast

Question 11

udder

Answer 11

NF-skin and streak (teat) cancal
sterile-teat cistern
gram +

Question 12

eye

Answer 12

NF-conjunctiva and cornea
sterile-anterior and posterior chambers

Question 13

respiratory tract

Answer 13

NF-cranial to the larynx or upper respiratory tract
sterile-lower respiratory tract
gram + and -

Question 14

urinary tract

Answer 14

NF-distal urethra
sterile-proximal urethra and bladder
gram + and -

Question 15

genital tract

Answer 15

NF- vagina posterior to cervix
sterile-uterus anterior to cervix

Question 16

Disease

Answer 16

abnormal condition affecting an animal which may be caused by external factors such as microorganisms
micro-organisms can come from exogenous or endogenous sources

Question 17

Endogenous

Answer 17

arise from bacteria that live on skin, mucous membranes as commensals

Question 18

exogenous

Answer 18

arise from environmental bacteria
disease occurs when impaired host defences allow these bacteria to invade (opportunistic infection)

Question 19

pathogen

Answer 19

those bacteria capable of causing disease are called pathogens

Question 20

pathogenicity

Answer 20

capacity of a bacteria to produce disease in a host

Question 21

virulence

Answer 21

variation in this capacity is referred
may vary between bacteria genera, species or strains and also depend on site of infection

Question 22

Obligate (True) pathogens

Answer 22

bacteria that must cause disease in order to be transmitted from one host to another and must also infect a host in order to survive they cant survive outside the host

Question 23

opportunistic pathogens

Answer 23

bacteria that are normal flora or saprophytes but can cause disease when something changes in the host animals that allows them to invade and cause disease

Question 24

predisposing factor for infection by opportunistic

Answer 24

factors causing damage to tissues and factors causing impairment of the hosts defence mechanisms that are the main reason leading to opportunistic infections caused by normal flora
introduction of microorganisms to body sites where they are not normally found
disturbance of normal flora

Question 25

Infectivity

Answer 25

capacity of the organism to become established in the tissues of the host
involves the ability to penetrate the tissues survive the host’s defences and multiply/disseminate within the host

Question 26

Numbers

Answer 26

number of potentially pathogenic bacteria present will also affect the development of disease
in general the more bacteria present, the more likely disease will occur but virulence does influence this

Question 27

Highly virulent pathogen

Answer 27

little host tissue compromise and or few bacteria to cause disease

Question 28

weakly virulent pathogen

Answer 28

lot of host tissue compromise and or many bacteria to cause disease

Question 29

Intermediate pathogens

Answer 29

intermediate response

Question 30

Presence of pathogen

Answer 30

bacteria that are capable of causing disease

Question 31

change to the host

Answer 31

innate host factors that predispose to infection
external or internal factor that modify host tissue/defense mechanisms

Question 32

innate host factors

Answer 32

species
sex
age

Question 33

external host stressors

Answer 33

extremes of temperature
nutritional deficiencies
overcrowding
transportation
change in feed
weaning

Question 34

what causes tissue damage

Answer 34

direct trauma/other infections/allergies
circulatory disturbances

Question 35

what causes changed host responses

Answer 35

endocrine changes
immunosuppressive organisms

Question 36

Sources of Bacteria

Answer 36

normal flora
animals incubating disease
animals with overt disease
carrier animals
fomites
environment

Question 37

Transmission of bacteria

Answer 37

variety of routes
inhalation
ingestion
inoculation
transplacental
via genital tract
via umbilicus

Question 38

what makes a good pathogen

Answer 38

ability to attach and colonize
ability to gain access to the body (invade)
ability to evade the innate defense mechanisms of the host
ability to produce molecules that cause dysfunction or damage