Intracellular bacteria

tell me about facultative pathogen

they’re capable of living and reproducing inside or outside of cells.

list facultative organisms

Yersinia

Mycobacterium

Salmonella typhi

Legionella.

tell me about Obligate pathogen

A microbe capable of causing host damage that is completely dependent on a host for survival and replication

name the Bacterial intracellular pathogens

Obligate and facultative pathogen

list Obligate organisms

•Chlamydia

•Rickettsia

•Coxiella

What obligate organism can be a

bacterial zoonoses

Chlamydia e.g. chlamydia citrusy

what is bacterial zoonoses

is disease that's passed from animals to humans. 

what percent of diseases come from zoonoses

75%

explain the overt disease of chlamydia

overt - easily observable or clinically obvious; symptomatic

diseases from chlamydia all form the same way, it’s always causes inflammation which is caused by immune responses in the mucosal tissue(wet tissue of the body)

describe Rickettsia

primitive small intracellular bacteria that is gram negative and they separate by binary fission (No bi-phasic cycle0 in a host cell

name the 2 classes of Rickettsia

• Spotted fever

• Typhus

which eukaryotic cell is Rickettsia related to

related to the predecessor of the mitochondria.

why is typhus a problem and how is rickettsia spread

because they are spread by arthropod vectors meaning they’ve their own hosts

explain rickettsia complicated symbiotic relationship

they have a symbiotic relationship with another organism biting another organism first, they’re usually tick borne, but can be lice or bedbugs.

The geographical distribution of rickettsia is directly related

to the geographic distribution of the host.

why do a high volume of ticks carry rickettsia

is because it's transmitted by trans ovarian meaning rickettsia can be passed down from gen to gen from the maternal line

what ticks are present in the uk

anaplasma in cows and in humans helvetica

pathogenesis of rickettsia

•Find a bite site

• They secrete molecules from their saliva

• make their way to Replicate in endothelial cells in the capillaries

• disruption of the capillary endothelium.

• Cell destruction causes blood leakage

how our body reacts to rickettsia

• disruption of the capillary endothelium.

• causing leakage of blood under the skin which causes spots

• sets off immune reaction in our bodies

• causes fluid entering those tissues and swelling and fever

• causes organ and tissue damage

coxiella burnetii causes what fever

Q fever

is coxiella burnetii gram negative

yes

coxiella burnetii is related to

Legionellales

coxiella burnetii mostly affects

sheep, goats and humans

coxiella burnetii is Highly contagious

true or false

true

describe acute q fever in humans

most people get undulate fever, malaise, myalgia, hepatitis, pneumonia.

describe chronic q fever in humans

if you don’t treat q fever initially it can become a chronic form, it targets heart valves and and causes endocarditis.

what happens when you have chronic q fever in humans

you cand die or have to have your heart valves change

how does chronic q fever affect preg women

plays a role in premature births, infertility and early miscarriage

how can q fever be transmitted by infected animals with q fever to non infected animals

if non-infected animals have contact with their faeces, shared in milk, during birth

how is q fever transmitted through birth

at birth when the placenta come out there is a lot of liquid, liquid is full of infectious organisms and it's breathed in. get into certain macrophages of your immune system.

how can q fever be transmitted by infected animals with q fever to humans

tick bites, contact with fluid of placenta, ingestion of unpasteurised dairy products

how did the Netherlands manage to get q fever under control

vaccinated goats, for an entire year, if there was a pregnant goat, the got was culled

what does Chlamydia, Rickettsia, Coxiella have in common

Gram-negative obligate intracellular bacteria

• Fastidious

• Parasitic

Sensitive to antibiotics (Doxycline)

• Controlled by a Th1 immune response

Reductive evolution

how does coxiella burnetii invade host cells

they rely on targets, tend to target active phagocytes, it takes over the lysosome that would normally digest the organism and turns it into its own little environment within the cell.

how does rickettsia invade host cells

They go and attract some actin and have these little actin tails from the host cell, and effectively use them to propel themselves through the host cell.

how does chlamydia invade host cells

it targets the mucosal cells, these cells trigger phagocytosis making them enveloped, They then form themselves into a vacuole, when coxiella takes over the vacuole tries to digest it, the chlamydia makes its own vacuole which has a low pH within that, it completes its life cycle before leaving the host cell.

Type 3 secretion system on chlamydia apical membrane do what?

stick to the host cell, go into the host cell membrane. And this using energy will have effector molecules into the host cell okay. They will reorganise the host cell skeletal structure to envelop it.

Chlamydial Developmental Cycle

the infective form of the organism is known as the elementary body.

it enters the host cell

starts to form the inclusion which is a little space inside the host where it's going to complete its life cycle

It then converts to the reticulate body, which is more metabolically active, it's much easier to replicate.

And then it just replicates by binary fission

triggered by the space and the contact with the membrane,

the ones that stop being contact with the membrane of the inclusions start to convert back into the elementary particles.

and start being reorganised

And then eventually either this entire inclusion is forced out the cell or burst out the cell

and completes next life cycle

how do we have immunity to chlamydia

Interferon gamma production. for the control of chlamydia

Host cells produce a lot of IL-8 cytokine, which recruits neutrophils

what is bad about neutrophils

they are a primitive part of the immune system and cause a lot of collateral damage wherever they go to get recruited.

what does it by waves of an inflammatory response

meaning you can have infection for years before your body clears it, most of the infection are asymptomatic, you get your first immune. Response gets dampened down. You get a secondary immune response. And third, this will cause waves of cell death, regeneration cell death, regeneration.

what does the regeneration of cells in the waves of an inflammatory response cause

Regeneration often results in scarring and scarring in the tissues, whether that's your gut, your reproductive tract, your on.

what happens in the Chlamydial Developmental Cycle if a cell is under stress

Faced with

Nutrient restrictions

Antibiotics

immune responses

These cells go into a persistent state. They form into aberrant body they go into stasis inside a host cell hiding from the immune system.

what determines if you get acute or chronic infection of Coxiella

ur immune response and level of infection

what can clear coxiella

a balanced immune response and interferon gamma production then you get apoptosis

what happens if you don’t get interferon gamma produced

infected cells survive that means that the organism can replicate and persist

In vitro stromal cells

Successful embryo implantation requires the progesterone dependent differentiation of endometrial stromal cells into secretory cells. We recently determined that Chlamydia inhibits and prevents the action of progesterone on uterine cells, chlamydia makes the cells refractory to progesterone it stops that inhibition of its own growth.

Reductive evolution in context with Chlamydia , Coxiella and rickettsia

process by which they’ve lost their genes and depend on their host cell to produce

Wolbachia are…

gram negative bacteria, infects arthropod species and nematodes

how does Wolbachia have a mutualistic relationship with its host

some species need Wolbachia colonisation to survive or reproduce

Wolbachia infects?

organs of the body but are most notable for the infections of the testes and ovaries of their hosts

where you find Wolbachia in its host

mature egg

transmission of Wolbachia

is down the maternal line of host

how does Wolbachia affect reproductive phenotype

in some species it causes feminization, parthenogenesis, male killing, Cytoplasmic incompatibility

what is Pathogenesis

the ability for some female species to reproduce without sex with males

what is feminization

infected males of Wolbachia develop into females or infertile pseudo females

what is male killing

occurs when infected males die during larval development, which increases the rate of born, infected, females

what is Cytoplasmic incompatibility

is the inability of Wolbachia-infected males to successfully reproduce with uninfected females or females infected with another Wolbachia strain

what do all of the results from Wolbachia on the reproductive phenotype have in common

decline in males and increase in females and by killing of the males, makes more females because less competition for females to compete for the same resources as their male counterparts.

Host survival advantages of having Wolbachia

viral resistance in flies, RNA viruses in mosquitoes become more resistant to viruses.

common house mosquitoes confer more insecticide resistance.

If Drosophila under nutritional stress not getting enough iron enough iron. Wolbachia will mediate iron metabolism

Wolbachia makes vitamin B12 for bedbugs

tell me about how Wolbachia infected sperm turn into viable sperm

have a toxin inside them, when it goes undergoes the first meiotic division after fertilisation, you chromosomes doesn’t disaggregate properly. Female gamete of the same Wolbachia strain has the antidot to rescue sperm from the toxin. turns that sperm into a viable sperm.

how is doxycycline an effective anti helminth to treat filarial nematodes

it kills Wolbachia, Wolbachia is essential as an endosymbiont of filarial nematodes, there are some species of nematodes that can’t reproduce without Wolbachia being present, there are some species that just cannot complete their life cycle and There are some species that will just die because they make the essential vitamins for them to live .

filarial nematodes responsible for

elephantiasis