Other gram (-) bacilli Flashcards
common characteristics of vibrio
gram negative, facultatively anaerobic
vibrio require __ for growth and __ fermentation
sodium for growth and glucose fermentation
all vibrio spp., are motile, catalase and oxidase positive except __
V. metschnikovii
organism primarily live in brackish or marine water
vibrio
organism that reside in freshwater
Aeromonas spp..
organism usually found in soil or water
C. violaceum
Mode of transmission
ingestion of contaminated water, fresh produce, meat, dairy products, or seafood or by exposure of disrupted skin and mucosal surfaces to contaminated water
agent of a diarrheal disease “Cholera”
V. cholerae
cholera is also known as
Asiatic cholera or epidemic cholera
in 2010 after a devastating earthquake in Haiti, more than 600,000 infection, and 7,000 deaths occurred as a result of ___ within a 24 month period.
Vibrio Cholerae O1 infections
during those outbreaks, v. cholerae was spread among people in?
fecal oral route due to poor sanitation
this bacillus has a dormant stage, that allows its long term survival in brackish water or salt water environments during interepidemic periods
Vibrio Cholerae
primary virulence factor of vibrio
cholera toxin or choleragen
how does the cholera toxin can be effectively release?
the organism must first infiltrate and distribute itself along the cells lining the mucosal surface of the gastrointestinal tract
for vibrio, ___ mediate the distribution of organisms and mucinase production allows penetration of the mucous layer.
motility and chemotaxis
this will provide the means by which bacilli attached to mucosal cells for the release of cholera toxin.
toxin coregulated pili
this toxin has been shown to disrupt the tight junctions of the intestinal cells effectively decreasing tissue resistance.
enterotoxin Zonula occludens (Zot) toxin
The action of cholera toxin is that it will trigger the ___, leading to production of profuse watery diarrhea, termed as ___
- hypersecretion of water and electrolytes by mucosal cells
- rice water stool or rice
watery stool
hallmark of cholera toxin activity
rice watery stool
vibrio: production of this watery diarrhea can produce a __ to the patient leading to __ and if these fluids are not replaced, it can lead to death.
- dramatic fluid loss
- severe dehydration and hypotension
it is associated with the Vibrio cholera cell envelope are positive markers for strains capable of epidemic and pandemic spread of the disease
somatic antigen 01 and 0139
strains carrying these markers almost always produce cholera toxin.
somatic antigen 01 and 0139
the strains that do not produce the toxin and hint do not produce cholera which are associated with non-epidemic diarrhea and extraintestinal infections.
non-01 or non-0139
second most common vibrio species implicated in gastroenteritis
Vibrio parahaemolyticus
v. parahaemolyticus is associated with a condition known as __
summer diarrhea in Japan
this organism is known to cause infections is associated with consumption of raw, improperly cooked, or recontaminated seafood, particularly oysters.
Vibrio parahaemolyticus
serotype of Vibrio parahaemolyticus known to cause the infections
serotype 03:K6
v. parahaemolyticus strains produce a heat stable hemolysin named __
Kanagawa
this strain is able to lyse human erythrocytes in high special high salt mannitol medium
Kanagawa toxin-positive
the strain of v. parahaemolyticus is able to lyse human erythrocytes in what medium?
Wagatsuma agar
Vibrio vulnificus infection can be categorized into two which could be ___ or either through __
primary septicemia or wound infections
v. vulnificus can occur in gastrointestinal route through __
consumption of shellfish especially raw oysters
v. vulnificus: Patients with liver dysfunction and syndromes that result in increased serum level of iron such as in ___ are particularly predisposed to this scenario
hemochromatosis, cirrhosis, thalassemia major and hepatitis
the least pathogenic for humans that usually originates from extraintestinal sources
v. alginolyticus
a common occupational hazard for people in constant contact with sea water, such as fishermen or sailors
v. alginolyticus
accepted specimens for vibrio alginolyticus
body fluids, pus, or tissue
what specimen should be transported in an appropriate holding medium to prevent dessication?
swabs - Cary bair
why buffed glycerol saline is not recommended?
glycerol is toxic for vibrio
enumerate the direct detection methods for vibrio
- Elisa latex agglutination test (ELISA)
- rapid antigen test
- immunochromatographic assays
specific method for testing Vibrio cholerae
immunochromatographic assays
gram morphology of vibrio
gram-negative, straight or slightly curved rod or comma-shaped
motility of vibrio spp.,
rapid darting or shooting star motility especially on your darkfield microscopy
culture media for vibrio
Thiosulfate citrate bile salts sucrose (TCBS) agar
content of TCBS that inhibit the growth of gram + organisms
1% sodium chloride bile salts
content of TCBS agar for the differentiation of the various vibrio species
sucrose
pH indicators of TCBS
bromothymol blue and thymol blue
the high pH of the TCBS medium is ___ which inhibits the growth of other intestinal microbiota
8.6
in TCBS, the sucrose fermenters present as ___ colonies while the non-sucrose fermenters present as __
sucrose fermenters - yellow colonies
non-sucrose - green colonies
it has a pH of 8.4 thatmay be used as an enrichment broth for obtaining growth of vibrio from stool
Alkaline peptone water
vibrio: After inoculation, the broth is then incubated for ___ at ___ and is then subcultures to TCBS.
5 to 8 hours at 35 °C
t or f: Oxidase testing is reliable when perform on colonies grown on TCBS medium.
oxidase testing is unreliable
other media that can also be used for vibrio
MacConkey and Salmonella Shigella agar
vibrio spp., can also grow on this agar and present as ___ except for what organism?
MacConkey and Salmonella Shigella agar
except for V. vulnificus
Is it possible to use sheep blood agar for vibrio?
yes, but oxidase should be performed.
why vibrio should be tested for oxidase if we use Sheep blood agar?
because lactose positive colonies from selective differential media such as MacConkey agar can give false positive oxidase reactions
test to differentiate Vibrio from Aeromonas
string test
string test uses __ in which there is cell lysis that will release your DNA which can be pulled up onto a string with an inoculating loop.
0.5% sodium deoxycholate
vibrio and aeromonas string test result
vibrio - positive
aeromonas - negative
a test that Vibrio are susceptible, and are oxidase-positive and glucose fermenters are resistant.
Vibrostatic Test (0129)
test to distinguish the vibrio cholerae
Vibrostatic Test (0129)
Vibrostatic Test (0129) result
v. cholerae 01 - susceptivle
v. cholerae non-01 - resistant
oxidase, indole, sucrose result for V. cholerae
- oxidase positive
- indole positive
- sucrose positive
only positive vibrio for gas from glucose
V. furnissii
vibrio spp., that ferment inositol
- V. cincinnatiensis
- V. metschnikovii
all vibrio are oxidase positive except __
V. metschnikovii
All vibrio spp., are halophilic or salt loving and require the addition of sodium for growth except for __.
Vibrio cholerae and Vibrio mimicus
vibrio that ferments lactose
v. vulnificus
the only vibrio that can growth in 0% NaCl
v. cholerae
common characteristics of aeromonas
- oxidase +
- ferments glucose
- gram negative
organism isolated from retail produce sources and animal meat products
aeromonas
Aeromonas typically grows at __
10-42 °C
refers to the organisms that grows well at 37C
mesophilic
mesophiles are all motile by the means of a __
single polar flagellum
enumerate the mesophilic aeromonas
hydrophila, veronii, caviae
organisms that grows optimally at 22C
psychrophilic
A. salmonicida grows well at
22-25 °C
this organism is a psychrophilic, non motile strains, and are not considered as human pathogens
A. salmonicida
clinical manifestations of aeromonas
intestinal infections and extraintestinal infections
aeromonas that can affect the neonate and pediatric populations
A. caviae
aeromonas that can affect people that are those with Hemolytic Uremic Syndrome or kidney disease
A. hydrophila
this organism can causes HUS and cholera-like disease
A. veronii biovar sobria
aeromonas that can commonly cause extraintestinal infections like septicemia and wound infections
A. hydrophila subsp. Hydrophilia
most common manifestations caused by A. hydrophila
subsp. Hydrophilia
cellulitis which occurs on the extremities
one of the most invasive type of Aeromonas infection and similarly has strong association with the species A
A. sepsis
aeromonas spp., which most likely affect to immunocompromised patients
- A. veronii biovar sobria
- A. jandaei
- A. hydrophila
aeromonas that is implicated in surgical wound infections involving the use of leeches for medicinal therapy after plastic surgery to relieve
venous congestion.
Aeromonas veronii biovar sobria
enumerate the beta-hemolytic aeromonas
A. hydrophila, A. veronii biovar sobria, A. jandaei
most common isolated specie of aeromonas
A. caviae
All aeromonas ferments __ on __ agar
lactose on MAC
why we must perform an oxidase test to Aeromonas which are taken from Sheep-blood?
to easily separate oxidase - and +
why we must perform an oxidase test to aeromonas from CIN?
because they may resemble Y. enterocolitica
t or f: vibrio cannot grow in 0% sodium chloride but thrive in 6% sodium chloride and even higher concentration
false, not all ky v. cholerae og mimicus can still grow w/out the presence of NaCl
enumerate the non-halophilic vibrio spp.,
V. cholerae and V. mimucus
this can be used for separating aeromonads from Plesiomonads
fermentation of inositol
inositol positive sp.,
Plesiomonas and Aeromonas is negative
The ability to ferment
__ with or without ___ distinguish Aeromonas from oxidase positive non-fermenting Pseudomonas isolates
ferment glucose with or without production of gas
term refers to the campylobacters that does not utilize any sugar
assacharolytic
common characteristics of camylobacter
- microaerophilic
- oxidase +
- gram - curved shaped
- assacharolytic
These are strongly associated with gastric, peptic, and duodenal ulcers, as well as with gastrointestinal carcinoma
helicobacter pylori
helicobacter pylori is the major cause of?
type B gastritis
helicobacter that has been isolated from the blood of patients with bacteremia, and patients with HIV infections.
Helicobacter cinaedi
they are known to cause abortion in domestic
animals, such as cattle, sheep, and swine and are primarily zoonotic organisms
campylobacter
most common cause of bacterial gastroenteritis worldwide
C. jejuni
MOT of camylobacter
- direct contact with animals and handling infected pets, such as dogs, cats, and birds
- consumption of contaminated water and dairy products, and improperly cooked poultry
- person to person transmission (sexually transmitted)
this can cause an autoimmune disorder known as Guillain Barre syndrome
campylobacter
Guillain Barre syndrome
an autoimmune disorder
characterized by acute paralysis, caused by damage of the peripheral nervous system
preferred specimen for Campylobacter fetus subsp. fetus
blood culture
for stool specimens for campylobacter, we should use __ and avoid __
Cary-blair and avoid buffered glycerol saline
specimen of choice for helicobacter pylori is __ that must be placed in __
gastric biopsy materials that must be placed in Stuart medium
for tissue sample of helicobacter, it may also be placed in __ frozen at
cysteine-Brucella broth with 20% glycerol frozen at -70C
media used for Campylobacter which is incubated at 37C
Campy Cefoperazone-vancomycin-amphotericin (CVA) medium
The incubation at 37 °C allows the recovery of Campylobacter species that are inhibited at __
42 °C
campylobacter spp., that can be isolated using routine culture media
c. fetus subsp. fetus, c. rectus, c. curvus
a charcoal-based blood free media that can also be used for campylobacter
Charcoal Cefoperazone Deoxycholate agar (CCDA)
medium used to recover helicobacter pylori
nonselective medium - CHOC agar or brucella agar with 5% horse red blood cells
selective medium - Skirrow’s agar
t or f: for helicobacter, It is important that the inoculated medium must be fresh and moist and that the culture be incubated in a microaerophilic environment (5% oxygen) with increased
humidity
true
t or f: for incubation of helicobacter, it must be aerobic.
false, microphilic and capnophilic
what is the ideal atmospheric environment for incubation of helicobacter?
10% oxygen, 5-12% carbon dioxide
what is the ideal atmospheric environment for incubation of campylobacter?
5% oxygen, 10% carbon dioxide, and 85%
nitrogen gas
what is the ideal incubation temp for stool cultures to increase the recovery of c. jejuni
42 °C
t or f: for recovery of Campylobacter fetus subsp. fetus, they can grow at 42C for incubation
false, 37C
recommended counterstain for campylobacter for gram staining
carbolfuchsin
t or f: counter staining for campylobacter should be extended to 2-3 mins
true
gram morphology of campylobacter
- non-spore forming
gram negative rods - long spirals or S-shaped
seagull wing shapes
motility of campylobacter
corkscrew motility
specimen of choice for campylobacter
stool or rectal swabs
what is the important characteristic for the identification of c. jejuni
positive hippurate hydrolysis test
each species of campylobacter can also be differentiated whether they are susceptible or resistant to ___ and __
nalidixic acid and cephalothin
the definitive identification of helicobacter pylori can be done through testing for?
rapid urease reaction on a gastric biopsy
The collected tissue sample is placed onto a __ medium, and is incubated at __ for 2 hours – color change
suggests the presence of Helicobacter pylori.
Christensen Urea medium
37 °C for 2 hours
A urease activity can also be detected by the __, which is reportedly sensitive and specific and is recommended for monitoring therapy.
urea breath test
immunologic assays for campylobacter and helicobacter
latex agglutination test
this testing is useful for epidemiologic studies for
campylobacter but is not recommended for routine diagnosis.
serologic testing
t or f: Serological testing is an important screening method for the diagnosis for the diagnosis of Helicobacter pylori infections.
true
