Week 3 - Enterococcus, Listeria, Erysipelothryx Flashcards
Enterococcus used to be ________ until 1984, when the advent of sequencing such as ____ _____ gene)
Streptococcus, 16S rRNA
Enterococcus is gram - _______.
positive
Enterococcus occurs in _____ or ____ _____ like Streptococcus
pairs, short chains
Enterococcus is Catalase _______ like _______.
negative, Streptococcus
Enterococcus is Lancefield Group __ antigen (antibody based serogrouping)
D
Enterococcus is a ________ ______.
facultative, anaerobe
Some species of enterococcus are ____-_______.
non-capsulate
Enterococcus is ____-_______ except some species.
non-motile
What media types are used for growing Enterococcus?
- Blood agar
- Media containing up to 40% bile esculin
- MacConkey agar
- Media containing high salt ( 6.5-10%)
- Kenner-fecal agar media
Enterococcus
Blood agar = ?
Non-hemolytic = gamma
Enterococcus
Media containing up to 40% bile esculin produces?
dark colonies (NB: Streptococcus does not grow on bile)
Enterococcus
MacConkey agar = ?
ferment lactose, producing small dark-red magenta colonies
Enterococcus
Media containing high salt = ?
Grow on media containing high salt (6.5-10%) concentration
(unlike Streptococcus)
Enterococcus
Kenner-fecal agar media
Selective media for enterococcus
Bile Esculin Azide Agar
Enterococcus is a highly ______ organism in ____ even if they
are __-____ forming bacteria
resistant, nature, non-spore
Enterococci are able to grow in?
hypotonic, hypertonic, acidic, or alkaline conditions
Enterococci are able to withstand?
detergents, oxidative stress, desiccation, heavy metals
Enterococci are resistant to?
multiple antimicrobials = member of ESKAPE
Enterococci are normal commensals of?
Mammals, birds, reptiles, fishes, insects.
Enterococci live in what parts of the body?
Colon and bile tract, Oral cavity, Urethra, Vulva/vagina in humans and animals
Enterococci is the ________ ____ and ____ microbiota of animals and humans. Thus, millions of them are _______
with feces daily to the environment
leading, gut, fecal, excreted
Name the body structures of Enterococci used for adhesion, colonization, and biofilm formation.
- collagen binding proteins
- endocarditis specific antigens (pili)
- surface proteins of enterococci
- Enterococcal polysaccharide on surface = cell wall carbohydrates serve as a capsular
- Aggregation substance = binds to host cells or bacteria-to-bacteria (conjugation)
- Trafficker of AMR genes by transferring them horizontally to enterococci spp.
- Acquired broad-spectrum antimicrobial resistance (AMR).
What enzymes do Enterococci use?
Gelatinase, Hyaluronidase
Gelatinase digests ?
Gelatine, elastin, collagen, haemglobin, and other bioactive peptides.
Hyaluronidase destroys blood _____ and ________ of the _______ tissue/_______ for spreading of _______ to the ______ tissue
vessels, mucopolysaccharides, connective, cartilage, bacteria, deeper
What toxins or secreted substances do Enterococci use?
- . Cytolysin/hemolysin (also called bacteriocin or enterocin)
- Sex pheromones
Cytolysin/hemolysin (also called bacteriocin or enterocin) kills by _____-forming on cell ______ of ___ and _____ blood cells
pore, envelope, red, white
Cytolysin/hemolysin (also called bacteriocin or enterocin) kills Gram-_______ bacteria competitors = to _____ its territory that contributes to ____ control
negative, defend, niche
Sex pheromones ________ expression of ______ substances which results in ________; thus, it is a means of acquiring and accumulating ______.
stimulate, aggregation, conjugation, plasmids
E. faecalis, E. faecium, E. durans occupy which host animals?
Multi-host species
E. faecalis, E. faecium, E. durans occupy which habitats?
intestinal tract, soil, water, food/feed
E. faecalis, E. faecium, E. durans cause which diseases?
- Septicemia in poultry
- mastitis in cows
- endocarditis in cattle & lambs
- urinary tract infection in pets
- chronic liver diseases (humans)
Overall, 65-95% of the diseases are by __________?
E. faecalis
E. faecalis, E. faecium, E. durans cause?
E. faecalis affects ______ of all ____, but exceptionally severe in ______ and ______ _____.
birds, ages, embryos, young chicks
E. faecalis usually colonizes the _____ first followed by E. ______, and then E. ______.
intestines, faecium, cecorum
E. cecorum has emerged as a major cause of _______ disease in adult _____ _____ causing ?
skeletal, broiler chickens
- osteomyelitis,
- femoral head necrosis,
- Spondylitis (i.e. back & neck pain due to inflammation of the vertebrate joints)
- arthritis.
Spondylitis in broiler chickens (showing it in humans)
Currently, enterococci rank among the top ___ leading cause of ________ infection in humans
3rd, nosocomial
In humans in the USA, Enterococcus spp. contributes to:
1. 20% of _______, ______ and
2. 10-16% _____ infection
endocarditis, endodontic, urinary
The majority of enterococcal infections are caused by E. _____ or E. _____
• E. faecalis accounts for the majority (65-95%) of ______ Enterococci infections in humans.
• E. faecium constitutes the majority of _______ and ______ resistant isolates of enterococci
faecalis, faecium, nosocomial, vancomycin, ampicillin
To a significantly lesser extent, infections are caused by other Enterococci species such as ?
E. durans, E. avium, E. gallinarum, or E. casseliflavus
What are the entry and exit transmission routes of Enterococci?
Entry = oral route: ingestion
Exit = feces from gut (their ecological niche) and other body parts via urine or milk (in case of mastitis)
Enterococci are excreted everyday in _____ concentrations in ____, usually between ____ and ___ bacteria per ___ wet weight
high, feces, 104, 106, gram
Enterococcus is routinely used as an indicator of fecal _______ and ______ quality of ____, ____, _____, ____ and ______ contamination/pollution by fecal
materials
contamination, hygienic, food, milk, meat, water, environmental
Collect samples and culture.
Treatment of Enterococci is challenging due to its _____
MDR
Faecium is more resistant, but faecalis causes disease more. Do AMR test to see which AMR is the most effective. Expensive ones are best (listed here).
Relative to the Streptococci, Enterococci are naturally _____to many commonly used antimicrobial agents such as _____ ______
resistant, beta-lactams
Enterococci generously give their AMR genes (_____) to other bacteria species by ______ (_____ _____)
plasmid, conjugation, horizontal transfer
MDR is more common E. ______ than E. ______
faecium, faecalis
How do you treat cases of Enterococcus infection?
In case the isolates are susceptible, use Beta-lactam antimicrobials e.g. amoxicillin, vancomycin OR Carbapenem
How do you control cases of Enterococcus infection?
- effective waste treatment of feces/manure and hygiene
- Water sanitation to reduce the incidence.
- Ensuring proper cleaning and disinfection of the facilities can reduce
environmental reservoirs of the bacteria. - Preventing immunosuppressive diseases and conditions, because
enterococcosis often occurs secondary to another disease.
What is the most clinically important strain of listeria?
Listeria monocytogenes
Listeria ivanovii (?)
Less pathogenic
Listeria is gram _______
positive
Listeria is _____-shaped ______.
rod, bacilli