Non Entero Gir Flashcards
Where is vibrio found
Can easily be isolated from water, suspended particulate
matter, algae, plankton, fish, and shellfish.
Where is vinrio found
Can easily be isolated from water, suspended particulate
matter, algae, plankton, fish, and shellfish.
How does vibrio fare with temp
They are temperature sensitive in that in temperate
climates when water temperature exceeds 20°C, as in the
summer months
How does vibrio fare with temp
They are temperature sensitive in that in temperate
climates when water temperature exceeds 20°C, as in the
summer months
General charcteristics of vibrio
• Motile with polar flagella
• Catalase +
• Oxidase +.
• Grow best in alkaline media
• Often found in brackish water
• Temperature sensitive
• Risk of infection transmitted by eating undercooked or raw
marine products
Common vibrio species
4 most common vibrio species encountered in the lab:
o V. cholerae
o V. parahaemolyticus
o V. vulnificus
o V. alginolyticus
Clinical manifestation of vibrio
Ranging from mild gastroenteritis to cholera and from
simple wound infections to fatal septicemia and
necrotizing fasciitis
Microscopic morphology of vibrio
• Asporogenous, gram-negative rods
• Polar, sheathed flagella when grown in broth but can
produce petritrichous, unsheathed flagella when
grown on solid media
• Curved gram-negative rods
Vubrio can reduce nitrate to nitrite except
V. metschnikovii
Is vibrio susceptible or resistant in mh or tripticase soy agar
Most are generally susceptible to vibriostatic
compound O/129 (2,4-diamino-6,7-
diisopropylpteridine), exhibiting a zone of inhibition to a
150µg Vibriostat disk on either a Mueller-Hinton or
trypticase soy agar
Positive string test observed as mucoid “stringing”
reaction after emulsification of colonies in 0.5%
sodium desoxycholate
vibrio
In vibrio, all species, , are
halophilic or salt-loving and require the addition of Na+
for growth ESCEPT FOR
except for V. cholera and V. mimicus
Vibrio can be differentiated from the similar genera
Aeromonas and Plesiomonas by
mean of key
biochemical and growth requirement characteristics
- Epidemic cholera
o V. cholerae O139
henotypically resembles V.
cholerae but fail to agglutinate in O1 antisera
V. cholerae non-O1 –
Shares a common flagellar (H) antigen and somatic
(O) antigen
o V. cholerae O139
o V. cholerae non-O1 –
o – the causative agent of cholera
O1
have been implicated in a variety of
extraintestinal infections including cholecystitis,
ear infections, cellulitis, and septicemia.
Non-O1 –
– share cross-reacting antigens with
Aeromonas trota
O139
Based on Biotypes
o Classical -
o El Tor
Based on Serotypes
o Ogawa
o Inaba
o Hikojima
Virulence Factors of vibrio
- mucinase
- choleragen
-coregulated pilus
-adehsion factor
-hemagluttination protease
-siderophores
-neuraminidase
symptoms of vibrio
Symptoms
Profuse vomiting
Watery diarrhea
Sunken eyes
Watery diarrhea and profuse vomiting can lead
to severe dehydration which leads to death.
- Mode of Transmission of vibrio
feces of the infected people -
through flies or leakage from sewage contaminated with the bacteria.
Ingestion of contaminated water and food
Treatment of vibrio
Oral rehydration salts
Intravenous fluids
Stool culture
contains numerous flecks of mucus
“Rice water” stools,
Can result in a rapid fluid and electrolyte loss thatleads to
dehydration, hypovolemic shock, metabolic acidosis, and
death in a matter of hours
cholera
cyclic adenosine monophosphate (cAMP) in vibrio explain
Accumulation of cyclic adenosine monophosphate (cAMP)
along the cell membrane, which stimulates hypersecretion
of electrolytes (Na+, K+, HCO3-) and water out of the cell
and into the lumen of the intestine
The gastrointestinal tract’s absorptive ability is
overwhelmed, resulting in the massive outpouring of watery
stools
bale watery stool
treatment of vibrio
- Resistant to tetracycline and doxycycline
diagnosis of vibrio
- vp positive
- polymyxin b susceptibility
- agglutinates chicken rbcs
V. cholerae serogroup O141
appears to be
associated with sporadic cholera-like diarrhea and
bloodstream infections
non-O1 serogroup strains have been implicated
in a variety of
extraintestinal infections including
cholecystitis, ear infections, cellulitis, and septicemia
share cross-reacting antigens with
Aeromonas trota, a somewhat uncommon cause of
diarrheal disease
O139 strains
Number 1 cause of Summer Diarrhea in Japan
Vibrio parahaemolyticus
Second most common Vibrio species implicated in
gastroenteritis
Vibrio parahaemolyticus
is implicated
in numerous food-borne outbreaks
V. parahaemolyticus serogroup O3:K6
Vibrio parahaemolyticus
Found in aquatic environments but limited to coastal or
estuarine areas despite a halophilic requirement of 1-
8% NaCl
Watery diarrhea, moderate cramps or vomiting, and
little if any fever
Occasionally isolated from extraintestinal sources
such as wounds, ear and eye infections, even in a case
of pneumonia
Vibrio parahaemolyticus
most strains produce a
heat-stable hemolysin that is able to lyse human RBC
in a special high-salt mannitol medium (Wagatsuma
agar)
Kanagawa phenomenon –
Kanagawa toxin positive
Vibrio parahaemolyticus
“lactose-positive” Vibrio
Vibrio vulnificus
Second most serious type of Vibrio infection
Vibrio vulnificus
vibrio vulnificus
Found in warm salt waters
Causes severe skin and soft tissue infections esp. in
shellfish handlers
Vibrio vulnificus
2 categories of v vilnificus
o Primary septicemia – surmised to occur through
the gastrointestinal route after the consumption of
shellfish, especially raw oysters
o Wound infections
VF of vibrio vilnificus
Resistant to complement and antibody-mediated
serum killing (thus systemic infections)
o Anti-phagocytic capsule
o Production of hydrolytic enzymes (cytolysins,collagenase, protease)
treatment of v vilnificus
doxycycline
Least pathogenic for humans and one most frequently
isolated
Vibrio alginolyticus
characteristics of v. alginolyticus
common inhabitant of marine environments
Strict halophile, requiring at least 1% NaCl and can
tolerate up to 10% NaCl
Nearly all isolates are from extraintestinal sources such
as eye and ear infections or wound and burn infections
Can be an occupational hazard for most people in
constant contact with seawater
transport of specimen of vibrio
Whenever possible, body fluids, pus, or tissues
should be submitted, but swabs are acceptable if
they are transported in an appropriate holding
medium, such as Cary-Blair, to prevent
desiccation
Buffered glycerol saline is not recommended as a
transport or holding medium because the glycerol
is toxic for vibrios
growing vibrio
- The salt concentration (0.5%) in most commonly
used laboratory media, such as nutrient agar or
sheep blood agar (SBA), is sufficient
mcconkey - negative except fot v.vulnificus kaya napagkakamalan na entero so need to do oxidase test since eto positive entero hinde
Both Mueller-Hinton agar and broth contain
sufficient salt to support the growth of the Vibrio
SBA or
chocolate (CHOC) agar, vibrios produce
SBA or
chocolate (CHOC) agar, vibrios produce medium
to large colonies that appear smooth, opaque,
and iridescent with a greenish hue
vibrio
If a selective medium is warranted, either because
of the clinical history (exposure to seafood or
seawater) or for geographic reasons (coastal area
resident or recent foreign travel), ___________________ is
recommended.
thiosulfate
citrate bile salts sucrose (TCBS) agar
It differentiates sucrose-fermenting (yellow) species
and from the nonsucrose fermenting (green) v
thiosulfate
citrate bile salts sucrose (TCBS) agar
nonsucrosefermenting (green)
pag sucrose fermenting yellow
vibrios: V. mimicus, V.
parahaemolyticus, V. damsela, and most V
vibrio vs aeromonas
Their general susceptibility to the vibriostatic agent
O/129 (150 µg) and positive “string test”
distinguishes them from Aeromonas
separates vibrio from Plesiomonas
inability to ferment inositol
_______________separates vibrio from the
Enterobacteriaceae (excluding Plesiomonas
shigelloides), and a __________________
separates vibrio from the oxidative Pseudomonas
Their positive oxidase reaction (except for V.
metschnikovii)
fermentative metabolism
cholarae treatment
oxycycline or
ciprofloxacin
Most vibrios are susceptible to
gentamycin,
tetracycline and chloramphenicol
gen chara of aeromonass
Consists of ubiquitous oxidase-positive, glucose
fermenting, gram-negative rods that are widely
distributed in freshwater, estuarine, and marine
environments worldwide
They are frequently isolated from retail produce
sources and animal meat products
motile with single polar flagellum
oxidase and indole positive
grom from 4-42c
mot:food and water
from molecular studies
resulted in the proposal of a separate family
Aeromonadaceae from Vibrio
Phylogenetic evidence
Responsible for a diverse spectrum of disease
syndromes among a variety of warm- and coldblooded animals including fish, reptiles, amphibians,
mammals, and humans
aeromonas
vf of aeromonads
exotoxins (enterotoxin, hemolysin, cytotoxin and protease),
adherence factors (S-layer,
capsule, pili)
Type III secretion system (T3SSS)
Aeromonads are classified based on
temperature:
meso - motile.37c
psychro - non motile.22-25c
movement:
motile (A. hydrophila, A. caviae, A. sobria)
non-motile (A. salmonicida)
Positive for Catalase, starch hydrolysis, lecithinase,
phosphatase, arginine dihydrolase, ONPG
hydrolysis
c. Motile group: A. hydrophila, A. caviae, A. sobria
- Ferments arabinose, trehalose, galactose, mannose
and dextrin - Negative for growth in KCN broth, nutrient broth with
7.5% NaCl, ornithine decarboxylase, tetrathionate
reductase, - Some strains produce pigments
d. Non-motile group: A. salmonicida
Clinical Manefistations
of aeromonad`
-intestinal infection
-The level and pattern of virulence is more like the
multifactorial patterns of the various E. coli
subgroups associated with enteric disease
- Five diarrheal presentations are observed in patients
in whom an Aeromonas has been isolated from their
stools
-extraintesinal infection
Five diarrheal presentations are observed in patients
in whom an Aeromonas has been isolated from their
stools
a. An acute, secretory diarrhea often accompanied
by vomiting
b. An acute, dysenteric form of diarrhea (similar to
shigellosis) with blood and mucus
c. A chronic diarrhea usually lasting more than 10
days
d. A cholera-like disease including rice- water
stools
e. The nebulous syndrome commonly referred to as
“traveler’s diarrhea” (similar to enterotoxigenic E.
coli)
is the species most frequently associated
with gastrointestinal infections, especially in neonate
and pediatric populations, and has been associated
with inflammatory bowel disease
A.caviae
has also been linked to choleralike disease characterized by abdominal pain, fever,
and nausea
A.veronii biovar sobria
A. veronii biovar veronii and surgical wound
infections involving the use of leeches for medicinal
therapy following plastic surgery to relieve venous
congestion has been noted.
A. veronii biovar veronii
It
appears that the leech ——————– has a
symbiotic relationship with this particular aeromonad
species within its gut, wherein the organisms aid in the
enzymatic digestion of the blood ingested by the leech
hirudo medicinalis
appears to be the most invasive
type of Aeromonas infection and likewise has a strong
association with the species A. veronii biovar sobria, A.
jandaei, and A. hydrophila.
Aeromonad sepsis
culture media of aeromonads
o After 24-hour incubation at 35° C, aeromonads
appear as large round, raised, opaque colonies
with an entire edge and a smooth, often
mucoid surface
o Frequently, an extremely strong odor is present,
and pigmentation ranges from translucent and white to buff-colored
o Hemolysis is variable but mostly b hemolytic
The most commonly isolated species, ———
is nearly always nonhemolytic or at best weakly
α-hemolytic on SBA
aeromonads
A. caviae,
might yield the
highest recovery of aeromonads
The combined use of ampicillin sheep blood
agar and a modified cefsulodin-irgasinnovobiocin (CIN II) plate (with only 4 µg of
cefsulodin instead of 15 µg),
l universal susceptibility to
ampicillin
hallmark feature of A.
trota
auremonads on cin medium
eromonas
will form pink-centered colonies from the
fermentation of mannitol, with an uneven, clear apronresembling Yersinia enterocolitica
if such a medium is
warranted for detecting chronic cases or
asymptomatic carriers,_______________is
recommended. This can be inoculated, incubated
_____________ at___________and subsequently sub cultured
if such a medium is
warranted for detecting chronic cases or
asymptomatic carriers, alkaline peptone water is
recommended. This can be inoculated, incubated
overnight at 35° C, and subsequently sub cultured
indole and oxidase of aeromonads
A positive oxidase distinguishes aeromonadsfrom
the family Enterobacteriaceae (except for Plesiomonas
shigelloides), and most clinically relevant
aeromonads are indole positive
The best tests to distinguish the aeromonads from
Vibrio spp. are the
string test (usually negative for
aeromonads and positive for vibrios)
testing for
sensitivity to O/129 (usually aeromonads and
plesiomonads are resistant and most vibrios are
susceptible)
determining
the ability to grow in the presence of NaCl
additional test to separate aeromonads and
plesiomonads from most vibrios is that
________grow quite well in
nutrient broth with 0% NaCl, but not in 6% NaCl.
Aeromonads and plesiomonads grow quite well in
nutrient broth with 0% NaCl, but not in 6% NaCl.
, most vibrios (specifically the halophilic
species) cannot grow in 0% NaCl but thrive in 6% NaCl
and even higher concentrations of NaCl
ability to ferment glucose, with or without
the production of gas, distinguishes
Aeromonas from oxidase-positive nonfermenting Pseudomonas isolates
Definitive identification of the aeromonads is
accomplished with a small number of
conventional and readily available biochemical
tests and antimicrobial markers and the use of
a simple dichotomous key, Aerokey II
Definitive identification
Campylobacters were formerly classified with the vibrios
because of their positive oxidase and characteristic
microscopic morphology, but ______________
have shown that Campylobacter spp. do not belong with the
vibrios
Campylobacters were formerly classified with the vibrios
because of their positive oxidase and characteristic
microscopic morphology, but DNA homology studies
have shown that Campylobacter spp. do not belong with the
vibrios
campylobacter
Although they may appear to be strict anaerobes, they
have been grown in a microaerophilic environment
Thermophilic species grow better at 42 C
have been known to cause abortion in
domestic animals such as cattle, sheep and swine
Campylobacter spp.
most common cause of bacterial
gastroenteritis
campylobacter jejun
Found in the intestines of avian species
campyobacter
campylobacter morphology
Curved or spiral-shaped gram-negative rod
Exhibits corkscrew or darting motility by polar flagella
Non-spore forming
Enteric campylobacters- may appear as long spirals or Sor seagull-wing shapes.
Gram-stained smears, these organisms stain poorly
For better visualization, carbol-fuchsin is recommended as a counterstain
Campylobacter spp. exhibit a characteristic “darting”
motility on hanging drop preparations or when visualized
under phase contrast microscopy
campylobacter colony morphology of its species
moist, runny looking,and spreading.
Colonies are usually nonhemolytic; some are round and raised and others may be flat.
Other Campylobacter species produce colonies similar to
those of C. jejuni. Although most do not produce pigment,
C. mucosalis and C. hyointestinalis can produce a dirtyyellow pigment
C. fetus subsp. fetus morphology
C. fetus subsp. fetus produces smooth, convex, translucent olonies. A tan or slightly pink coloration is observed in some enteric campylobacter colonies.
