microbiology of animals Flashcards
the bodies of animals provide a –, —- and —– env for bacteria.
wet, warm nutritious
—- —- forces bacteria to colonize inside animal tissues
evolutionary presser
what factors influence the richness and the abundance of microorganisms in the body
temp, pH, nutrient supply, immune system (genetic factors)
as the animal develops, various body surfaces become progressively —-, the individual acquires its —- —-
colonized, normal microbiome
what are commensals
at firs most microorganisms may seem to be commensals. they take advantage of the host (nutrients, shelter) and they do not harm the host
in what ways can commensals be beneficial
1) AA supply
2) vitamin supply
3) metabolic pathways
4) protection against new incoming microbial populations (occupy the territory)
5) teach the immune system
(T/F)
commensals may also be parasitic
explain
true
some commensals may be pathogenic under specific conditions and commensals of one species may infect another species
in animals the vast majority of the microorganisms may be found in the —–
GI tract
phylogenetic studies suggest that different lineages evolved a —- life style
herbivorous
what are the challenges of herbivores
digestion is difficult for them due to the presence of cellulose and complex sugars (lignin, pectin, hemicellulose) in their diet –> also insoluble
animals lack the enzyme —-
cellulase
microorganisms in the gut have a —– relationship with the host. due to their ability to break down cellulose
mutualistic
name the 2 digestive strategies that have evolved in herbivores
1) foregut fermentation: fermentation chamber precedes acidic stomach
2) hindgut fermentation: use caecum and/or large intestine as fermentation chambers
rumen
foregut fermenation chamber
how is the pH of the fermentation chamber maintained + what is its pH
by the saliva - composed of sodium bicarbonate and sodium phosphate
5-7
rumen is an —- env
anaerobic
temp in the rumen
39-40 degrees
(T/F)
a large portion of the rumen contains cellulase
FALSE
fermentation in the rumen is mediated by —— that hydrolyze cellulose into —- and —– , then sugars are fermented into —— , — , —-
cellulolytic microbes, glucose , cellobiose, VFAs, CO2,CH4
what happens to VFAs after fermentation
thy pass through the rumen wall, enter the bloodstream and are utilized by the animal as its main nrg source
what kind of micro-organism exist in the rumen
ciliated protozoa, bacteria, archaea –> 16S
——- (microorganism) produce cellulase, and the product may be used by other microorganisms
ruminococcaeceae
methanogens are —
anaerobes
reactions carried out by methanogens
4H2+CO2 –> CH4+2H2O +nrg
CH3COOH –>CO2 + CH4 + nrg
—- used by methanogens is not available to the host. uptown —- % of the nrg value of the feed can be lost as CH4
acetate, 10
—- inhibits methanenogenesis. This compound is an —
monensin, antibiotic
after several hours of microbial digestion, small portion of the rumen contents are —– , well chewed, and the swallowed again. smaller food particles are collected by the —- and moved to the —–, where excess —– is collected.
regurgitated , reticulum , omasum, water
what happens after when food particles enter the omasum
they enter the stomach (abomasum) and from there to the intestines. the mass of microbial cells are subjected to digestion and serves as a major source of AAs and vitamins
in non ruminant organisms fermentation takes place in the —– , provides —– absorbed by the animal
caecum, organic acids
the microbial mass that grows I cellulose and other polysaccharides are —— digested and are —– therefore these type of organisms require more:
Rabbits and hares got around this problem by consuming the —- —- they produce
not, excreted, AAs, vitamins , feacal pellets
commensals are microorganisms routinely found on the bodies of —– individuals. they normally colonize the body without causing any —–
most healthy, infections
normal microbiome
- microorganisms usually found associated with human body tissue
- humans are colonized by microorganisms at north
- normal microbiome changes over time and according to the condition of the host (diet, age, sex, occupation ,etc)
the —- is composed of an inner layer of living, actively —– cells and an outer layer of — cells
epidermis, replicating, dead
function of sebaceous glands and apocrine sweat glands
they produce salt water with various amounts of proteins, sugars and lipids. secretions are slightly acidic and have some antimicrobial activities —-> esp lipids and proteins
function of the dead cell layer of the skin
tough Barries that prevent microorganism from penetrating deep tissues
the skin is generally a —, — env that does not support the growth of most microorganisms
dry, acid
the —– that carry secretions are colonized by only a few well adapted species –> gram ——
ducts, positive
the normal microbiome secretes —- that kills incoming competitors and protects to a certain extent against colonization of harmful bacteria
bacteriocin
the oral cavity is a —-, — microbial habitat. both —- and —niches are available
heterogeneous, complex, aerobic, anaerobic
in the oral cavity there are high concentrations of nutrients new the —–
surfaces
the test consist of a —– —- also called —-, surrounding living tissue (dentin and pulp)
mineral matrices, enamel
dental plaque
extensive forth of oral microorganisms, esp streptococci results in a thick bacteria layer called dental plaque.
bacteria colonize tooth surfaced by:
attaching to acidic glycoproteins deposited there by saliva
sucrose + bacterial plaque
streptococcus mutans synthesize extracellular polysaccharides (dextran) that aid its attachment t the surface
s mutans and various lactobacilli ferment sucrose and producee lactic acid that demineralizes the tooth enamel
as plaque continues to develop —- bacterial species being to grow
anaerobic
microorganisms in the the colon are ——- or ——– like:
strict anaerobes, facultative aerobes, bactericides, enteric bacteria (e.cloi) yeasts, anaerobic protozoa (entamoeba coli)
high —- in gut communities between individuals
variability
intestinal microorganisms carry out a variety of metabolic pathways that produce various nutrients like:
AAs, vitamins
** sulfate reduces
notes
microorganisms in the gut contribute to the —- of the GI tract
maturing
microbes in the gut affect:
early development, health, predisposition to disease
microbiome of the nose and nasopharynx is very similar to that of the —– . name some of these microorganisms
mouth, staphylococci, streptococci, corynebacteria
—– may harbour potential pathogens under control by the host immune system like:
nasopharynx
streptoccouc pneumonia, haemophilus infleunzae, neisseria meningitidis
***healthy carries
the lower response tract includes:
microorganism level:
lungs, trachea, bronchi
- very low –> determined by culture technique
the genitourinary and urinary tract are generally —– of microorganisms due to the flossing action of the urine
free
under what conditions may the urinary tract become infected with microorganisms
1) altered conditions such as pH changes can cause potential pathogens from the urethra to multiply and cause disease
2) a few of the normal microorganisms of the GI tract can cause urinary tract infections like: e.cloi, proteus mirabillis
how may the vaginal tract protect the urinary tract
microorganisms in the vaginal tract degrade glycogen and produce lactic acid which reduces to pH 4.5 –> low pH protects against infection
name the sterile zones in the body
1) blood
2) spinal fluid
3) internal portion of urinary tract (bladder, kidney)
4) peritoneal cavity (gut cavity)
5) pleural cavity (lung cavity)
6) sinuses
7) interior region of other body tissues (bone, muscle, …)
