EMES 446 Module 6 Part 2

Module 6 Lecture 2 and TB of the Sea

how does studying chemosymbiosis contribute to human health?

antimicrobial surface biology

sulfide detoxification and mitochondrial medicine

antimicrobial surface biology

anti-biofilm coatings

medical-device surface engineering

colonization resistance strategies

sulfide detoxification and mitochondrial medicine

dysregulated H2S metabolism has been linked to cardiovascular disease, inflammatory disorders, neurological disease, and cancer

the enzymes and pathways identified in sulfide-adapted symbiosis provide comparative models for understanding H2S biology in humans

mycobacterium characterized by

gram positive

aerobic

rod-shaped

waxy and thick cell wall

there are more than

190 species

mycobacterium is divided into

rapid and slow growing species

mycobacterium is widespred in

soil and water environments

nontuberculous mycobacterium (NTM)

mycobacteria not including those part of the mycobacterium tuberculosis complex (MTBC)

diseases typically occur in immunocompromised individuals

thin peptidoglycan layer surrounded by a thick outer lipid rich coating

can infect humans, livestock, birds, fish, amphibians, reptiles, etc

mycobacterium marinum

fish tuberculosis

slow growing endosymbiont

pathogenic NTM

ubiquitous species

primarily infects fish but can infect humans

infection of M. marinum

causes fish mycobacteriosis

it occurs in

open waters, aquariums, and aquaculture

establishes in the host about

14 days after exposure

transmission occurs through

consumption of infected dead fish

contact with infected fish skin or through gills

there are two stages of infection

an intracellular and extracellular stage

intracellular stage

infects and replicates within macrophages

extracellular stage

found extracellularly in necrotic tissue

it causes

uncoordinated swimming

abdominal swelling

loss of weight

skin ulceration

granuloma formation in liver, kidney, and spleen

significance

many documented infections in aquaculture affecting the commercial farming of fish

case study 1: observed gilthead seabream (sparus aurata) from

2 onshore recirculating aquaculture systems

case study 1: fish were euthanized and

observed for external clinical signs of disease

case study 1: data was collected over

3 time points

case study 1: conclusion

similar signs of external clinical disease in both tanks BUT

tank 1 (RAS A): ~1%

tank 2 (RAS B) up to 33%

case study 2: investigated the immune response of Coho salmon to

M. marinum infection in the liver and kidney

case study 2: how many healthy coho salmon were acquired and kept in tanks?

100

case study 2: M. marinum that was isolated from the liver of a natually infected Coho salmon was

injected into each salmon

case study 2: the livers and kidneys were separately sampled from 3 infected fish at

0, 2, 4, and 6 weeks after infection

case study 2: provided a considerable amount of information about

genes expressed by liver and kidney

genes expressed by immune related genes

characterization of the immune response

case study 2: 15 immune related genes in both the liver and kidneys demonstrated

significant upregulation

similarities of M. marinum to TB

most closely related mycobacterial species to TB outside of the M. tuberculosis complex

shares 3000 orthologs with 85% amino acid common identity with TB

both cause granulomas in their hosts

human infection

differencees when comparing M. marinum to TB

grows much faster in lab

has a larger genome that allows it to colonize a greater variety of hosts

by studying the presence of and immune response to M. marinum we can

better understand how to treat it in aquaculture

M. marinum is a great model bacteria to

use to study treatments for TB