Enterococcus, Listeria, Erysipelothryx Flashcards
1
Q
Enterococcus used to be ________ until 1984, when the advent of sequencing such as ____ _____ gene)
A
Streptococcus, 16S rRNA
2
Q
What kind of bacteria is enterococcus? How does it occur? Is it catalase positive or negative? What is it lancefield group? Does it have a capsule? Is it motile?
A
- Gram-positive
• Occur in pairs or short chains like Streptococcus
• Catalase negative like Streptococcus
• Lancefield Group D antigen (antibody based serogrouping)
• Facultative anaerobe
• Non-capsulate (some species)
• All non-motile except some species
3
Q
What media types are used for growing Enterococcus?
A
- Blood agar
- Media containing up to 40% bile esculin
- MacConkey agar
- Media containing high salt ( 6.5-10%)
- Kenner-fecal agar media
4
Q
How does enterococcus present on blood agar? Is it hemalytic?
A
Non-hemolytic = gamma
5
Q
Enterococcus:
Media containing up to 40% bile esculin produces?
A
dark colonies (NB: Streptococcus does not grow on bile)
6
Q
Enterococcus:
What can you see on MacConkey agar ?
A
ferment lactose, producing small dark-red magenta colonies
7
Q
Enterococcus:
What do you see on media containing high salt = ?
A
Grow on media containing high salt (6.5-10%) concentration
(unlike Streptococcus)
8
Q
Enterococcus
What is Kenner-fecal agar media?
A
Selective media for enterococcus
9
Q
What is this media?
A
Bile Esculin Azide Agar
10
Q
Enterococcus is a highly ______ organism in ____ even if they
are __-____ forming bacteria
A
resistant, nature, non-spore
11
Q
Enterococcus:
What conditions are they able to grow in?
A
hypotonic, hypertonic, acidic, or alkaline conditions
12
Q
Enterococcus:
What factors are they able to withstand?
A
detergents, oxidative stress, desiccation, heavy metals
13
Q
Enterococcus
What are they resistant to?
A
multiple antimicrobials = member of ESKAPE
14
Q
Enterococcus:
What are they normal commensals of?
A
Mammals, birds, reptiles, fishes, insects.
15
Q
Enterococcus: What parts of the body do they live in?
A
Colon and bile tract, Oral cavity, Urethra, Vulva/vagina in humans and animals
16
Q
Enterococci is the leading ____ and ____ microbiota of animals and humans. Thus, millions of them are _______ with feces daily to the environment
A
- gut,
- fecal,
- excreted
17
Q
What are the body structures of Enterococci used for adhesion, colonization, and biofilm formation?
A
- 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).
18
Q
What enzymes do Enterococci use?
A
Gelatinase, Hyaluronidase
19
Q
What does Gelatinase digests ?
A
Gelatine, elastin, collagen, haemglobin, and other bioactive peptides.
20
Q
Enterococcus:
What does Hyaluronidase do?
A
- Hyaluronidase = destroy blood vessel and mucopolysaccharides of the connective tissue/cartilage
for spreading of bacteria to the deeper tissue
21
Q
What toxins or secreted substances do Enterococci use?
A
- . Cytolysin/hemolysin (also called bacteriocin or enterocin)
- Sex pheromones
22
Q
Whar is cytolysin/hemolysin? What does it do?
A
- Cytolysin/hemolysin (also called bacteriocin or enterocin) =
- kills by pore-forming on cell envelope of red and white blood cells 2. kills Gram-negative bacteria competitors = to defend its territory that contributes to niche control
23
Q
Enterococcus:
What are sex pheromones? What do they do?
A
- Sex pheromone = stimulate expression of aggregation substances which results in conjugation;
thus, it is a means of acquiring and accumulating plasmids
24
Q
E. faecalis, E. faecium, E. durans occupy which host animals?
A
Multi-host species
25
E. faecalis, E. faecium, E. durans occupy which habitats?
intestinal tract, soil, water, food/feed
26
E. faecalis, E. faecium, E. durans cause which diseases?
1. Septicemia in poultry
2. mastitis in cows
3. endocarditis in cattle & lambs
4. urinary tract infection in pets
5. chronic liver diseases (humans)
27
Overall, 65-95% of the diseases are by \_\_\_\_\_\_\_\_\_\_?
E. faecalis
28
29
What diseases are caused by enterococcus spp. in poultry?
1. E. faecalis affects birds of all ages, but
exceptionally severe in embryos and young chicks
2. E. faecalis usually colonizes the intestines first followed by E. faecium, and then E.cecorum
3. E. cecorum has emerged as a major cause of
skeletal disease in adult broiler chickens causing
✓ osteomyelitis, ✓ femoral head necrosis,
✓ Spondylitis (i.e. back & neck pain due to
inflammation of the vertebrate joints) ✓ arthritis.
30
What is seen in this image?
Spondylitis in broiler chickens (showing it in humans)
31
Why are enterococci an important zoonotic bacterium of humans?
Currently, enterococci rank among the top 3rd leading cause of nosocomial
infection in humans
• In humans in the USA, Enterococcus spp. contributes to:
1. 20% of endocarditis, endodontic and 2. 10-16% urinary infection
• The majority of enterococcal infections are caused by E. faecalis or E. faecium
• E. faecalis accounts for the majority (65-95%) of nosocomial Enterococci infections in humans. • E. faecium constitutes the majority of vancomycin and ampicillin resistant isolates of enterococci
• To a significantly lesser extent, infections are caused by other Enterococci
species such as E. durans, E. avium, E. gallinarum, or E. casseliflavus
32
In humans in the USA, what do Enterococcus spp. contributes to?
In humans in the USA, Enterococcus spp. contributes to:
1. 20% of endocarditis, endodontic and 2. 10-16% urinary infection
33
What are the majority of enterococcal infections caused by?
* The majority of enterococcal infections are caused by E. faecalis or E. faecium
* E. faecalis accounts for the majority (65-95%) of nosocomial Enterococci infections in humans.
• E. faecium constitutes the majority of vancomycin and ampicillin resistant isolates of enterococci
34
To a significantly lesser extent, infections are caused by other Enterococci species such as ?
E. durans, E. avium, E. gallinarum, or E. casseliflavus
35
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
```
36
How much enterococci is excreted in feces daily?
➢ Excreted everyday in high concentrations in feces, usually
between 104 and 106 bacteria per gram wet weight
37
What is enterococcus usually used as an indicator of?
• Thus, routinely used as indicator of:
1. fecal contamination and hygienic quality of food, milk, meat,
2. water and environmental contamination/pollution by fecal
materials
38
What samples are typically taken for isolation and identification for enterococcus?
- feces
- urine
- milk
- blood
39
Treatment of Enterococci is challenging due to its \_\_\_\_\_
MDR
40
Relative to the Streptococci, Enterococci are naturally \_\_\_\_\_
to many commonly used antimicrobial agents such as _____ \_\_\_\_\_\_
resistant, beta-lactams
41
Enterococci generously give their AMR genes (\_\_\_\_\_) to other bacteria species by ______ (\_\_\_\_\_ \_\_\_\_\_)
plasmid, conjugation, horizontal transfer
42
MDR is more common in what species of enterococcus?
E. faecium, E. faecalis
43
How do you treat cases of E. faecalis infection?
Beta-lactamase
✓ Penicillin
✓ Ampicillin
✓ amoxicillin
Aminoglycosides
✓ Gentamycin
✓ Streptomycin
Their is resistance with vancomycin.
44
How do you treat cases of E. faecium infection?
- vancomycin.
Resistant to beta lactamases and aminoglycosides.
45
How do you treat cases of enterococcus that are vancomycin resistant infections? What is the drawback to these infections?
These antimicrobials are expensive
- Linezolid
- Daptomycin
- Tigecycline
46
47
How do you control cases of Enterococcus infection?
1. effective waste treatment of feces/manure and hygiene
2. Water sanitation to reduce the incidence.
3. Ensuring proper cleaning and disinfection of the facilities can reduce
environmental reservoirs of the bacteria.
4. Preventing immunosuppressive diseases and conditions, because
enterococcosis often occurs secondary to another disease.
48
What is the most clinically important strain of listeria?
Listeria monocytogenes
49
What is Listeria ivanovii ?
50
What is the morphology and characteristics of listeria ?( shape, type of bacteria, spore forming? catalase? motility? Hemolytic? growth conditions?)
• Gram positive
* Rod/bacilli
* Facultative anaerobe
* Non-spore forming
* Catalase positive
* Intracellular pathogen of animals and humans
* Has flagella for motility and invasion
* Beta-hemolytic on blood agar
- Resistant to high salt (7-12%) in the inside host cell
• Grow at cold (4°C) temperature
51
Listeria:
What is seen in this image?
Tumbling motility or “umbrella” shaped colony growth at
20-28C in a semisold motility media (because of its 1-5
flagella)
actin jet motility inside host cell
Umbrella-shaped subsurface listeria colony growth in semi-solid
motility media.
52
What are the diverse serotypes of l. monocytogenes? What are they based on?
• Has 14 serotypes based on its somatic (O) and flagella (H) antigens
• Of these, 3 serotype are important (virulent) since they cause the
vast majority of clinical case
1.1/2a = the most frequently isolated from food
2. 1/2b
3. 4b = causes the majority of human epidemics
53
What are the two key issues for Isolation of Listeria on a culture media?
1. It require enrichment media as it is fastidious bacteria
2. It requires prolonged inubationtime for the recovery of stressed Listeria cells.
54
How do you create an enriching media for Listeria?
1. Mullen-Hinton agar with 5% sheep blood as enrichment
2. Beta-hemolytic colonies on blood agar
3. Ferments glucose, maltose, lactose …produces acid but no
gas.
55
How can you recover stressed Listeria cells?
1. Incubation for weeks at 4°C on agar plates until the formation of visible colonies
2. This method of isolation usually does not allow for the isolation of injured or weak Listeria cells
56
57
How can listeria adapt to changing conditions?
• Resistant to high salt (7-12%) in the media
• Survive and multiply on inanimate objects
• E.g. silage through the transition processes from one host to another
• adapt to changing temperature (-0.4-45°C),
pH (4.4-9.6)
✓ Can multiply at refrigerator Tm (4°C)
58
What is the habitat listeria lives in?
• Grow as saprophytes in soil and decaying vegetation in the environment
✓ Listeria is not commensal rather a real pathogen
✓ Isolated from swage, water, feed, food
• Abundant in cold temperate
✓ EU, North America
✓ Can grow at low temperatures \< 4°C
59
What are the host ranges of listeria?
• It has diverse host ranges and isolated from:
✓ Humans ✓ 42 species of mammals ✓ 22 species of birds ✓ fish ✓ insects
• It is more common in ruminants (mainly sheep)
✓ It causes seasonal outbreak in ruminants ✓ It is sporadic in pig and horse
• It is one of the well recognized foodborne pathogen in humans
60
Listeria is most common in what species?
It is more common in ruminants (mainly sheep)
It causes seasonal outbreak in ruminants
It is sporadic in pig and horse
61
\_\_\_\_\_\_\_ is a well recognized food borne pathogen in humans.
Listeria
62
What are the points of entry and exit of Listeria?
• Entry: It enters the host by ingestion (oral)
1. Livestock: highly associated with feed/feeding of Silage with high iron content is a risk
factor for acquiring Listeria in ruminants
As you increase iron concentration in silage, it promotes listeria contamination
2. Humans: Consumption of contaminated raw vegetables, meat, and milk
Exit: It exits from the host via feces, vaginal discharge (abortion), milk (mastitis)
Detected in feces, milk, slurry, soil, feed, water, food
63
What body structures does Listeria possess?
1. 1-5 Flagella - for motility, adhesion & invasion
2. Internalin (A, B & C) - for host cell adhesion & invasion
3. invasion-associated protein (iap) - for host cell adhesion
& invasion
64
Listeria form \_\_\_\_\_\_\_.
Biofilms
65
What cells does listeria multiply in ? What is the benefit of this?
Intracellular pathogen and multiply in tissue cells,
monocytes, & macrophages
✓ So hide from the immune patrolling of the host cells,
antibodies & antimicrobials
66
What enzymes does Listeria use?
1. super-oxide dismutase from listeria
2. Phospholipase
67
What does superoxide dismutase do for listeria?
1. super-oxide dismutase from listeria
✓ protects listeria against free radicals from the host phagocyte cells
68
What does phospholipase do for listeria?
Pore-forming lysis on endocytosis membrane of 2. Phospholipase
the host to free itself from lysosome (vacuoles) in the cytoplasm of the host cell
69
What toxins or secreted substances does Listeria use?
1. Beta-hemolysin
2. listeriolysin O
3. Bacteriocins (listeriolysin S) –
4. Actin-polymerizing protein (actA)
70
What does Beta hemolysin and listeriolysin O do that benefits listeria?
Pore-forming lysis on endocytosis membrane of the host to free itself from lysosome (vacuoles) in the cytoplasm of the host cell
71
Bacteriocins (listeriolysin S) – ____ competing gut microbiota
kill
72
What does actin polymerizing protien do for listeria?
4. Actin-polymerizing protein (actA)
✓ instructs host cell for deposition of its actin- filaments on the end of Listeria
✓ Then Listeria uses the host actin filaments for propelling to the nearby cells.
✓ Such host actin-based zipper mechanism for propelling and transmission from cell to cell are used by:
✓ Listeria, Rickettsia, and Yersinia pseudotuberculosis
73
Whar are the 4 known barrier of body systems that Listeria enters?
1. Blood-brain barrier
2. Placental barrier
3. Intestinal barrier
4. Cell membrane lipid bilayer barrier (intracellular).
74
75
Listeriosis is characterized by ?
Febrile gastroenteritis, septicemia/shock, placentitis, brain stem & cranial nerve dysfunction
76
77
The two major clinical manifestations of listeriosis are?
neural form vs. visceral form
78
Neural form of listeriosis in silage-fed sheep shows?
microabscess in the brain
Ataxia and ‘circling disease’
Unilateral facial paralysis
head tilting to one-side
ear dropping (one ear)
tongue protrusion
salivation
79
Visceral form of listeriosis is linked with septicemia. What can you see in the visceral form?
Gastroenteritis
Septicemia
Liver and spleen damage
Fetoplacental tropism (abortion)
Myocarditis
Osteomyelitis (bone + bone marrow)
mastitis
80
\_\_\_\_\_\_\_\_\_\_\_\_ is the third leading cause of death from food-borne illnesses in the United States, with approximately 260 deaths annually
L. monocytogenes
81
82
How do you treat Listeria infections?
Treatment : Listeria is a Gram-positive intracellular pathogen
Ampicillin (200 mg/kg per day, IV)
Chlortetracycline (10 mg/kg per day for 5 days, IV)
Penicillin (44,000 U/kg per day for 7 days, IM)
Trimethoprim-sulphmethoxazole (10 mg/kg per day, IV)
83
How do you control Listeria outbreaks?
Its control is difficult as ubiquitously present
Little is known as to its risk factor (except silage) to control
Control Listeria growth in the feed mainly in silage
Vaccination with live attenuated listeria vaccine (in Norway)
and commercial killed vaccine in some countries
84
Which strain of Erysipelothrix is medically the most important?
Erysipelothrix rhusiopathiae
85
What is the Morphology of Erysipelothrix rhusiopathiae?
* Gram positive • Long filament (rod)…. (causes emboli)
* Facultative anaerobe • Catalase negative • Oxidase negative • Non-motile • non-spore forming
86
Erysipelothrix rhusiopathiae is shaped like ?
Causes?
Long filament (rod)…. (causes emboli)
87
Erysipelothrix rhusiopathiae is Catalase \_\_\_\_\_\_\_\_
Negative
88
Erysipelothrix rhusiopathiae is oxidase \_\_\_\_\_\_\_\_
negative
89
Erysipelothrix rhusiopathiae is \_\_\_\_-motile
non
90
Erysipelothrix rhusiopathiae is \_\_\_\_\_-spore forming.
non
91
Erysipelothrix rhusiopathiae
92
Erysipelothrix has ____ serotypes based on _____ antigen on the cell wall
28, peptidoglycan,
93
The pig is susceptible to at least ___ serotypes of Erysipelothrix.
15
94
Field cases of swine erysipelas are predominantly caused by three E.
rhusiopathiae serotypes:
1. 1a
2. 1b, or
3. 2
95
In swine, ?% of isolates are classified into serotype 1 or 2
75–80
96
What culture media can be used for Erysipelothrix?
* Blood agar (-hemolytic after 24h)
* Heart infusion + supplemented with sodium azide & crystal violet
* Nutrient broth + 1% glucose
* Triple sugar iron
97
How can you achieve nutrient rich media for Erysipelothrix?
It require enrichment media
1. Alpha-hemolytic colonies on blood agar
2. Heart infusion agar with sodium azide & crytal violet for plating pig
sample & incubated for 48h
3. Ferments glucose, lactose producing acid but not maltose and mannitol
98
Hydrogen sulfide H2S is produced by 95% of strains of Erysipelothrix species on triple sugar iron (TSI) agar
99
Erysipelothrix is unique & probably the only Gram-positive bacillus/rod bacteria that produce H2S (gas)
100
What is seen in this image?
Triple Sugar Iron
101
What is seen in this image?
Blood agar with alpha hemolysis after 24 hours in Erysipelothrix
102
What habitat do Erysipelothrix occupy?
Habitat – Tonsils
- lymphoid tissue of intestinal tracts in carrier animals
- Detected in the slurry of cattle herds or sewages from abattoirs
103
What is the non-human animal host range of Erysipelothrix?
Mammals (pig, horses, cattle), birds (turkey), reptiles, amphibians, fish
Pigs including wild boars (wildlife)
Detected in horses with vegetative endocarditis
Turkey with swollen snood
104
What is the human host range of Erysipelothrix?
Humans due to occupational zoonotic disease
• people who have contact with pigs, poultry, fish (vets, abattoir workers, butchers,
farmers)
It causes a purple colored hardened finger swelling in humans
It may disseminate from skin to cause endocarditis, pneumonia and meningitis.
105
What are the points of entry and exit of Erysipelothrix?
Entry: oral route
enter the host orally to colonize tonsils
Flies may transmit it
• Exit: fecal route (urine, saliva, nasal
secretion)
exit from the host mainly with feces to spread
to the environment (effluent) and new host
106
What are the virulence factors of Erysipelothrix?
No well known virulence factors except the following surface structures and enzymes
107
How do the structural surfaces of Erysipelothrix cause its virulence?
1. Capsule (lipopolysaccharide, slime or glycocalyx) – for resistance to phagocytosis
2. Surface protective proteins (spA, B and C antigens) – for biofilm formation,
adhesion, and to elicit immune response.
These surface proteins can be used as a protective vaccine
108
What enzymes does Erysipelothrix posess?
1. Neuraminidase (sialidase)
2. Hyaluronidase
3. Superoxide dismutase
109
What does Neuroaminidase do in Erysipelothrix?
attachment, invasion, destroy
hemorrhage and thrombosis
This can lead to bacterial emboli and infarction in the heart valves (endocarditis), spleen, liver, lung, kidney, and joints (polyarthritis)
110
What does Hyaluronidase do for Erysipelothrix?
Hyaluronidase – for spreading via destroying hyaluronic acid and polysaccharides between adjacent cells
111
What does superoxide dismutase do for Erysipelothrix?
3. Superoxide dismutase – for protection from intracellular killing by macrophages
112
Erysipelothrix is the problem of \_\_\_, \_\_\_\_\_\_\_\_, and _____ …. it is also?
pigs, ruminants, turkey, zoonotic/humans
113
114
What is the diamond shaped skin form of erysiopelothrix?
rhomboid urticarial purple/black and hard skin lesion mainly around belly, inside the thighs, throat,
neck, ears
115
What is seen in this image?
Swollen snood in acute turkey erysipelas
116
What is seen in this image? Who is at risk?
- E. rhusiopathiae and a characteristic purplish, swollen, painful, hardened rash known as
erysipeloid…..but Do NOT produce PUS!
Fish handlers, poultry, pig workers, abattoir workers or vets are at risk
117
What is the cardiovascular form of Erysipelas?
• Purple/black discoloration of the skin of belly with bluish (cyanotic) of the extremities due to
• septicemia, emboli, infarcts, & vegetative endocarditis that blocks heart valve orifice.
Erysipelas ranked 2nd next to Sterpt. suis in causing endocarditis in pig industry
118
What is the joint form of Erysipelas?
Polyarthritis (swelling joints, lameness and stiffness) mainly elbow, hip, hock, stifle, and knee joints
119
What are the 5 tropisms for erysipelas based on body parts?
- diamond shaped skin form
- pneumonia
- cardiovascular form
- Joint form
- Uterine form
120
What is the uterine form if Erysipelas?
Abortion mainly due to fever, but the bacteria is isolated from fetuses (i.e. congenital/vertical infections
indicating it can pass the placental layers)
121
What are the clinical manifestations of Erysipelothrix?
✓ Lacy-skin disease, but it is not a pus forming bacteria
- purple/ red/ black colored diamond shaped skin lesion (pig) is indicator sign
- Swollen snood ( turkey)
- Purplish swollen and hardened skin in humans
Systemic Signs:
✓ Septicemia,
✓ fever,
✓ thrombosis,
✓ ischemic necrosis,
✓ abortion
✓ Polyarthritis (lameness of many limbs)
✓ vegetative endocarditis with selective attachment to heart valves
122
What are the differences in the skin presentation between Erysipelothrix vs Staph. hyicus or Strep Suis? Systemic signs?
• Erysipelothrix (lace-like or diamond shape skin lesion) - not pus forming
Staphylococcus hyicus = greasy skin
2. Streptococcus suis = contagious pyoderma
Systemic signs of Erysipelothrix:
Systemic Signs:
✓ Septicemia,
✓ fever,
✓ thrombosis,
✓ ischemic necrosis,
✓ abortion
✓ Polyarthritis (lameness of many limbs)
✓ vegetative endocarditis with selective attachment to heart valves
- Strep suis is similar , however shape of lesion and pus formation is what is different
123
How can you diagnose Erysipelothrix via bacteriology?
1. Gram positive - Long filamentous (Rod)
2. Catalase negative
3. Alpha-hemolytic
4. H2S in TSI agar
124
How can you diagnose Erysipelothrix via clinical signs?
looking for lace like or diamond shaped skin lesions.
125
What is seen in this image?
Lace like / diamond skin lesions on swine.
126
What is seen in this image?
lace like or diamond patterns
127
How can you diagnose Erysipelothrix via serology?
serotyping) - 28 serotypes
128
How do you treat Erysipelothrix infections?
Penicillin (50,000U/kg
per day for 3 days, IM)
ampicillin
ceftiofur
129
How do you control Erysipelothrix infections?
• Vaccinate pigs \> 3 months age with formalin-killed
vaccine bi-annually
but vaccine fails due to several serotypes i.e. 28
short duration of immunity i.e. protection lasts less
than 6 months
• Therefore, the feasible control methods are:
1. Remove clinically sick or test positive animals from the
herd immediately (but no reliable test?)
2. Good hygiene (biosecurity): all-in all-out policy followed by
disinfection of the house before restocking
130
Summary Erysipelothrix
131
Summary Listeria
