non entero git complete Flashcards
GENERAL CHARCTERESTICS OF VIBRIO spp
(what temp, where do they grow, motility, catalase and oxidase state, media they grow best in, transmission)
They are temperature sensitive in that in temperate
climates when water temperature exceeds 20°C, as in the
summer months
Can easily be isolated from water, suspended particulate
matter, algae, plankton, fish, and shellfish.
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
4 most common vibrio species encountered in the lab:
o V. cholerae
o V. parahaemolyticus
o V. vulnificus
o V. alginolyticus
vibrio spp clinical manifestation
Ranging from mild gastroenteritis to cholera and from simple wound infections to fatal septicemia and
necrotizing fasciitis
Microscopic Morphology of vibrio
(gram stain, shape, flagella)
Asporogenous (non spore producing) , gram-negative rods
Polar, sheathed flagella when grown in broth but can
produce peritrichous, unsheathed flagella when
grown on solid media
Curved gram-negative rods
physiology of vibrio spp
Can be highly pleomorphic especially under suboptimal growth conditions
Facultatively anaerobic
All clinically species are oxidase positive and able to
reduce nitrate to nitrite except for V. metschnikovii
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
All species, except for V. cholera and V. mimicus, are
halophilic or salt-loving and require the addition of Na+
for growth
Can be differentiated from the similar genera
Aeromonas and Plesiomonas by mean of key
biochemical and growth requirement characteristics
Subgroups of V. cholerae O1
- Ogawa (A, B)
- Inaba (A, C)
- Hikojima (A, B, C)
- Epidemic choler
o- Epidemic cholera
V. cholerae O139
– phenotypically resembles V.
cholerae but fail to agglutinate in O1 antisera
V. cholerae non-O1
Vibrio cholerae
BASED ON O ANTIGEN
o O1 – the causative agent of cholera
o O139
– share cross-reacting antigens with Aeromonas trota
- epidemic cholera
o non-O1 – have been implicated in a variety of
extraintestinal infections including cholecystitis,
ear infections, cellulitis, and septicemia.
v cholera based on biotypes
o Classical -
o El Tor – able to agglutinate chicken red blood cells
– able to agglutinate chicken red blood cells
El Tor
vibrio Based on Serotypes
o Ogawa
o Inaba
o Hikojima
Virulence Factors of vibrio
o Cholera - Toxins
Mucinase
Cholera toxin or Choleragen:
Coregulated pilus: adherence to mucosal cells
Adhesion factor
Hemagglutination protease:
Siderophores
Neuraminidase
choleragen
Cholera toxin or Choleragen: an enterotoxin,
consist of 2 toxic A subunits and 5 binding B
subunits.
Once ingested, the bacteria colonize the small
intestine, in which they multiply and produce
choleragen
adherence to mucosal cells
Coregulated pilus:
induces intestinal
inflammation and degradation of tight junctions
Hemagglutination protease:
: iron sequestration
Siderophores
: increase toxin receptors
Neuraminidase
symptoms of vibrio or v cholera ata
Profuse vomiting
Watery diarrhea
Sunken eyes
Watery diarrhea and profuse vomiting can lead
to severe dehydration which leads to death.
Treatment of vibrio
- Doxycycline
if resistant: azithromycin and ciprofloxacin
Oral rehydration salts
Intravenous fluids
Stool culture
Manifests in acute cases as a severe gastroenteritis
accompanied by vomiting followed by diarrhea
Cholera
“Rice water” stools, contains numerous flecks of mucus
what bacte
vibrio cholarae
Can result in a rapid fluid and electrolyte loss that leads to
dehydration, hypovolemic shock, metabolic acidosis, and
death in a matter of hours
vibrio
vibrio is resistant to what
Resistant to tetracycline and doxycycline
El Tor differentiate to classic
o Voges-Proskauer positive
o Hemolyzes RBCs
o Inhibited by polymyxin B (50µg), and is able to
agglutinate chicken RBCs
o Different phage susceptibility patters
appears to be
associated with sporadic cholera-like diarrhea and
bloodstream infections
V. cholerae serogroup O141
have been implicated
in a variety of extraintestinal infections including
cholecystitis, ear infections, cellulitis, and septicemia
Other non-O1 serogroup strains
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 is found in
Found in aquatic environments but limited to coastal or
estuarine areas despite a halophilic requirement of 1
8% NaCl
clinical manifes\tation of v. parahaemolyticus
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
symptoms appear 24 to 48 hrs after consumption of raw seafood esp oyster
kanagawa phenomemon is associated with
v parahaemolyticus
most strains produce a
heat-stable hemolysin that is able to lyse human RBC
in a special high-salt mannitol medium
what is the phenomenon and what is the medium called
Kanagawa phenomenon
wagatsuma agar is the medium
Commonly referred to as the “lactose-positive” Vibrio
Vibrio vulnificus
Second most serious type of Vibrio infection
Vibrio vulnificus
Found in warm salt waters
v. vulnificus
v vulnificus is found in
Causes severe skin and soft tissue infections esp. in
shellfish handlers
also necrotizing fascilitis asnd multiple organ system failure
first v cholarea non 01 srteain producing epidemic disease
0139 strain vibrio
v vulnificus 2 categoris of disease
primary septicemia
wound infection
surmised to occur through
the gastrointestinal route after the consumption of
shellfish, especially raw oysters
primary septicemia (v vulnificus)
vf of v vulnificus
o 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 vulnificus
doxycycline
Least pathogenic for humans and one most frequently
isolated in vibrio
Vibrio alginolyticus
Vibrio alginolyticus
Least pathogenic for humans and one most frequently
isolated
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
o Vibrios are not fastidious, and only a few special
collection and processing procedures are
necessary to ensure the recovery of vibrios from
clinical material
Specimen Collection and Transport
of vibrio
o 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
o Buffered glycerol saline is not recommended as a
transport or holding medium because the glycerol
is toxic for vibrios
o Even strips of blotting paper soaked in liquid stool
and placed in airtight plastic bags are considered
viable specimens for up to 5 weeks
o Stool specimens should be collected as early as
possible in the course of the illness, before the
administration of any antimicrobial agents
culture media vibrio
o The salt concentration (0.5%) in most commonly
used laboratory media, such as nutrient agar or
sheep blood agar (SBA), is sufficient to support
the growth of any vibrios present SBA or
chocolate (CHOC) agar,
o The SBA plate should also be examined for the
presence of α- or β-hemolysis. On MacConkey
(MAC) agar, the pathogenic vibrios usually grow
as nonlactose fermenters
o However, lactose-fermenting species such as V.
vulnificus may be overlooked and incorrectly
considered to be members of the family
Enterobacteriaceae, such as Escherichia coli. It
therefore is imperative to determine the oxidase
activity of any suspicious Vibrio-like colony
o This can be accomplished by either directly testing
colonies from SBA or CHOC agar plates with
oxidase reagent or by subculturing any
suspicious lactose-fermenting colonies on
MAC to an SBA plate for next-day testing
o Both Mueller-Hinton agar and broth contain sufficient salt to support the growth of the Vibrio spp. most often isolated from clinical specimens
vibrios produce (ano itsura)
medium
to large colonies that appear smooth, opaque,
and iridescent with a greenish hue
MAC or cefsulodin-irgasin-novobiocin agar may
give false-positive oxidase reactions
vibrio
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),
thiosulfate
citrate bile salts sucrose (TCBS) agar is
recommended.
tcbs
sucrose-
fermenting (yellow) species such as V. cholerae,
V. alginolyticus, V. fluvialis, V. furnissii, V.
cincinnatiensis, V. metschnikovii, and some V.
vulnificus strains from the
nonsucrose-
fermenting (green) vibrios: V. mimicus, V.
parahaemolyticus, V. damsela, and most V.
vulnificus strains
is recommended. It differentiates sucrose-fermenting (yellow) species from the Non sucrose-
fermenting (green)
thiosulfate citrate bile salts sucrose (TCBS) agar
in vibrio
Their general susceptibility to the vibriostatic agent
O/129 (150 µg) and positive “string test”
distinguishes them from
Aeromonas
inability to ferment inositol (except for V.
cincinnatiensis and some strains of V.
metschnikovii) separates them from
vibrio
Plesiomonas
all vibrio is incapable of inability to ferment inositol
except for V. cincinnatiensis and some strains of V. metschnikovii
Their positive oxidase reaction (except for V.
metschnikovii) separates them from the Enterobacteriaceae (excluding Plesiomonas
shigelloides), and a fermentative metabolism
separates them from the oxidative
Pseudomonas
all vibrio are positive oxidase except
V.
metschnikovi
It is important to note that with the halophilic or
salt-loving vibrios, it often is necessary to add
at
least 1% NaCl to most biochemical media to obtain
reliable reaction results
id of vibrio
o Rapid and semiautomated identification systems
o Serology
antimicrobial suscpetibilityof vibrio
o cholerae susceptible to doxycycline or
ciprofloxacin
o Most vibrios are susceptible to gentamycin,
tetracycline and chloramphenicol
The recommended antimicrobial susceptibility
testing methods are
standardized disk diffusion
(KirbyBauer) or dilution susceptibility testing
methods
aeromonas charateristics
Consists of ubiquitous oxidase-positive, glucose-
fermenting, gram-negative rods that are widely distributed in freshwater, estuarine, and marine environments worldwide
Phylogenetic evidence from molecular studies
resulted in the proposal of a separate family
Aeromonadaceae from Vibrio
Aeromonads are gram negative straight rods and most are motile by means of a single polar flagellum
All aeromonads, in general, can typically grow from 4-42°C
Oxidase and Indole positive (mostly)
Glucose fermenter
Motile with single polar flagellum
Ubiquitous in fresh and salty water
They are frequently isolated from retail produce
sources and animal meat products
aeromonas
Responsible for a diverse spectrum of disease
syndromes among a variety of warm- and cold-
blooded animals including fish, reptiles, amphibians,
mammals, and humans
aeromonas
a. salmonicida
non-motile and atrichous
vf and mode of transmission of aeromonas
Virulence factors: exotoxins (enterotoxin, hemolysin,
cytotoxin and protease), adherence factors (S-layer,
capsule, pili) Type III secretion system (T3SSS)
MOT: Food and water
aeromods are classified into
mesophilic, psychrophilic, motila and non motile
mesophilic aermonod
Hydrophila complex which includes A.
hydrophila, A. bestiarum, and certain motile strains of A. salmonicida
Veronii complex includes A. veronii biovar sobria (formerly misidentified as A. sobria),
A. veronii biovar veronii, A. jandaei, A. trota, and A. schubertii
Caviae complex includes the species A.
caviae, A. media, and A. eucrenophila
psychrophilic aeroonad
psychrophilic - Grow best at 22-25°C - Non-motile
Salmonicida (fish pathogen)
motile aeromonad
A. hydrophila, A. caviae, A. sobria
Non-motile group of aeromonad
A. salmonicida
Non-motile group: A. salmonicida
- 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
The level and pattern of virulence is more like the
multifactorial patterns of the various E. coli
subgroups associated with enteric disease
aeromonads
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)
A.caviae
A.caviae is the species most frequently associated
with gastrointestinal infections, especially in neonate
and pediatric populations, and has been associated
with inflammatory bowel disease
More serious complications, usually from infections
with???? nclude
hemolytic uremic syndrome or kidney disease that may
require a kidney transplant
More serious complications, usually from infections
with A. hydrophila and A. veronii biovar sobria, include
hemolytic uremic syndrome or kidney disease that may
require a kidney transplant
has also been linked to cholera
like disease characterized by abdominal pain, fever,
and nausea
A.veronii biovar sobria
___________infections involving the use of leeches for medicinal
therapy following plastic surgery to relieve venous
congestion has been noted. These patients can
develop serious aeromonad wound infections.
These patients can
develop serious aeromonad wound infections.
leech
Hirudo medicinalis
Aeromonad sepsis a
ppears 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.
incubating aereomonads
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
Hemolysis is variable on SBA, but most major
clinical species, such as _______________________display strong β-
hemolysis
Hemolysis is variable on SBA, but most major
clinical species, such as A. hydrophila, A. veronii
biovar sobria, and A. jandaei, display strong β-
hemolysis
The most commonly isolated species, A. caviae,
is nearly always
(type of hemolysis)
nonhemolytic or at best weakly
α-hemolytic on SBA
does aeromonads ferment lactose
yes
Tmight yield the
highest recovery of aeromonads
he combined use of ampicillin sheep blood
agar and a modified cefsulodin-irgasin-
novobiocin (CIN II) plate (with only 4 µg of
cefsulodin instead of 15 µg),
its unusual universal susceptibility to
ampicillin
A. trota
Aeromonas
will form pink-centered colonies from the
fermentation of mannitol, with an uneven, clear apron
resembling
Yersinia enterocolitica.
separates aeromonads and yersisnia
oxidase test performed on SBA colonies will easily
separate the oxidase-positive aeromonads from the
oxidase- negative yersinias
The use of an enrichment broth generally is not
considered necessary. However, if such a medium is
warranted for detecting chronic cases or
asymptomatic carriers, __________ is
recommended.
aeromonads
alkaline peptone water
An important screening procedure for aeromonads is
to perform an oxidase test and a spot indole on
suspicious colonies on SBA, especially β-hemolytic
colonies
testing for
sensitivity to O/129
(usually aeromonads and
plesiomonads are resistant and most vibrios are
susceptible)
additional test to separate aeromonads and
plesiomonads from most vibrios is that of
Aeromonads and plesiomonads grow quite well in nutrient broth with 0% NaCl, but not in 6% NaCl.
vibrio pwede 6% bawal sa 0%
how to distinguish V. cholerae from V.
mimicus
both V. cholerae and V.
mimicus are nonhalophilic and grow quite well
without additional salt, any salt tolerance test must
be used in conjunction with both the string test and
the O/129 disk to distinguish aeromonads from
this major pandemic cholera species and the less
common sucrose- negative V. mimicus
For separation of aeromonads from plesiomonads, one
can utilize the fermentation of
inositol— where
aeromonads are negative and plesiomonads are
positive
astly, the 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
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
DNA homology studies
asacchrolytic
campylobacter
Although they may appear to be strict anaerobes, they
have been grown in a microaerophilic environment
CAMPYLOBACTERACEAE
organisms require oxygen, but at a
concentration less than that of room air; 5% is normally
optimal
CAMPYLOBACTERACEAE
cause abortion in
domestic animals such as cattle, sheep and swine
Campylobacter spp.
– most common cause of bacterial
gastroenteritis
Campylobacter jejuni
isolated most
frequently from blood cultures and is rarely associated with
gastrointestinal illness
Campylobacter fetus subsp. fetus
Thermophilic species grow better at 42 C
campylobacter
- may appear as long spirals or S-
or seagull-wing shapes.
Enteric campylobacters
campylobacter morphology
Curved or spiral-shaped gram-negative rod
Exhibits corkscrew or darting motility by polar flagella
The typical colony morphology of C. jejuni and other enteric campylobacters is moist, runny looking,and spreading.
Colonies are usually nonhemolytic; some are round and raised and others may be flat.
Gram-stained smears, these organisms stain poorly
For better visualization, carbol-fuchsin is recommended as
a counterstain
If safranin is used, counterstaining should be extended to 2
to 3 minutes.
campylobacter
Campylobacter spp. exhibit a characteristic “darting”
motility on hanging drop preparations or when visualized
under phase contrast microscopy
Campylobacter spp.
Other Campylobacter species produce colonies similar to
those of C. jejuni. Although most do not produce pigment,
__________ can produce a dirty
yellow pigm
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 dirty
yellow pigm
produces smooth, convex, translucent
colonies. A tan or slightly pink coloration is observed in
some enteric campylobacter colonies.
C. fetus subsp. fetus
C. fetus contains two subspecies: C. fetus subsp. fetus
and C. fetus subsp. venerealis
C. fetus subsp. fetus
and C. fetus subsp. venerealis
Patients infected with C. jejuni present with a
diarrheal
disease that begins with mild abdominal pain within 2 to 10
days after ingestion of the organisms
Cramps and bloody diarrhea often follow the initial
signs. Patients may experience fever and chills and,
rarely, nausea and vomiting
In most patients, the illness is self-limited and usually
resolves in 2 to 6 days. Untreated patients can remain
carriers for several months
Other enteric Campylobacter infections (i.e., those
caused by C. coli and C. lari) have similar clinical
manifestations
Strong evidence suggests it that
infection plays a role in Guillain-Barré syndrome, an
Campylobacter
acute paralysis
due to damage to the peripheral nervous system.
Guillain-Barré syndrome
is the most common form of acute
infectious diarrhea in developed countries involving mostly
young children
Campylobacteriosis
Indirectly transmistted by the consumption of
contaminated water and dairy products and improperly
cooked poultry
Some person to person and sexually transmitted
Feco-oral transmission also occurs
campylobactereae
causes gastrointestinal disease
C. coli and C. lari
Non-motile strains and those lacking adhesin are avirulent
Damages the mucosa of the jejunum, ileum and colon
campylobacter
can be recovered from gastric biopsy
materials. Samples must be transported quickly to the
laboratory
H. pylori
storage of campylobacter
Stuart medium can be used to maintain the viability of
the organisms if a delay in processing is anticipated
o Tissue samples may also be placed in cysteine-
Brucella broth with 20% glycerol and frozen at
−70°C
An enriched selective agar, —————–is a commonly used medium to isolate C. jejuni
and other enteric campylobacters
CAMPY-BAP (blood agar
plate),
Other selective media that have been successful in
recovering Campylobacter spp. are
Butzler medium
and Skirrow’s medium
a modification of the original Butzler
medium, contains cefoperazone, rifampin, colistin, and
amphotericin B; it seems to inhibit normal colon
microbiota better than the original formulation
Medium V,
provides better supression of fecal biota,
even when this medium is incubated at 37° C
CAMPY CVA
To recover H. pylori, a combination of a nonselective
medium, such as
CHOC agar or Brucella agar with 5% horse red blood cells, and a selective medium,
such as Skirrow’s agar, may be used
TREATMENT OF CAMPYLOBACTER
Susceptibility to Nalidixic acid or Cephalotin
ANTIGEN AND ANTIBODY OF CAMPYLOBACTER
\
Antigen detection: Lior or Penner serotyping -
Antibody detection: Latex particle agglutin
C. jejuni and other enteric campylobacters grow
optimally at
42°C
, on the other hand, is a rare stool
isolate, and growth is suppressed at 42°C therefore
to isolate this organism, media should be incubated at
37°C
C. fetus subsp. fetus
he ideal atmospheric environment
for these organisms contains a gas mixture of 5%
O2, 10% CO2, and 85% N2 for Campylobacter
spp.
Campylobacter
5% to 10% O2 and 5% to 12% CO2 for
Helicobacter spp
EXCEPT FPR a strict
anaerobic environment does not support the
growth of most Campylobacter spp.
Except for C. rectus and C. curvus, a strict
anaerobic environment does not support the
growth of most Campylobacter spp.
To observe the typical motility, organisms should be
suspended in
CAMPYLOBACTER
Brucella or tryptic soy broth
o Distilled water and saline seem to inhibit motility
A positive hippurate hydrolysis is an important
characteristic for the identification of
C. jejuni
placed
onto Christensen’s urea medium and incubated at
37°C for 2 hours. A rapid color change suggests the
presence of
H. pylori
sensitive and
specific and is recommended for monitoring therapy
UREASE TEST
Bacterium found in the stomach of over half of the world’s
population
HELICOBACTER PYLORI
Can cause inflammation of the stomach lining
H PYLORI
H PYLORI CHARACTERISTUCS
gram-negative bacterium that’s shaped like a
curved rod and it has 2 to 6 flagella, kind of like multiple tails, all at one end which it uses for movement.
It’s positive for urease, oxidase and catalase
Microaerophile (needs oxygen to survive, but requires less
than the levels typically found in atmosphere)
have either a single polar flagellum or
multiple flagella at one pole.
Helicobacter spp
Primarily linked to gastric infections
H PYLORI
cause a
low-grade inflammatory process, producing a chronic
superficial gastritis
H PYLORI
Most common cause of chronic gastritis (type B gastritis)- a
chronic condition formerly associated primarily with stress
and chemical irritants
H PYLORI
H PYLORI CAUSES
Most common cause of duodenal ulcers
Second most common cause of gastric ulcer
Associated with development of gastric cancer and gastric
lymphoma
Long term H. pylori infection resulting in chronic gastritis is
an important risk factor for gastric carcinoma
H. pylori being classified as carcinogen
STORAGE OF H PYLORI
o Stuart medium maintains the viability of the organism if
delay is anticipated
o Tissue samples may be placed in cysteine-brucella
broth with 20% glycerol and frozen at -70 C
o Culture and urease production (Urea breath test)
To recover H. pylori, combination of:
- Nonselective medium: CHOC agar or Brucella
agar with 5% horse red blood cells - Selective medium: Skirrow’s
CLINICAL PRESENTATIOPN OF H PYLORI
o Asymptomatic
o Peptic ulcer disease (gastric, duodenal)
o Non-ulcer dyspepsia
o Gastric carcinoma
o Gastric mucosa-associated lymphoid tissue lymphoma - MALT lymphoma, MALToma, marginal zone B-cell
lymphoma of MALT type
H PYLORI
o Once it arrives within the stomach, H. pylori use its
flagella to propel toward the stomach lining.
- It will migrate to regions where pH is less acidic (antrum – has fewer parietal cells)
- It then uses adhesin proteins to stick to the surface
of foveolar cells where it can release a number of
virulence factors which help it both survive and
thrive, and cause damage to the mucosa. - Urease
- Ammonia
H PYLORI VF
o Cause extensive damage to epithelial cells.
o Some strains of H. pylori produce cytotoxin-associated
gene A or cagA and exotoxin vacuolating cytotoxin A
or vacA
o Cytotoxin-associated gene A (cagA) – interferes with
the attachments between epithelial cells that normally
help protect the underlying mucosal layers -
Induces inflammatory
immune response within
the gastric lining, called gastritis
CHRONIC INFECTIONS OF H PYLORI
ANG HABA BASAHIN MO NALANG EVEYTIME U SEE THIS LOL
DIAGNOSIS OF H PYLORI
o Slender, curved Gram-negative bacillus
o Urease-producer
o Mucosa stomach
o Growth
o Microaerophilic atmosphere, slow
o Group 1 carcinogen (gastric carcinoma)
o Fecal antigen test
o Blood titers
o Urease breath test
o Upper gastrointestinal endoscopy
o Culture H
o No clinical symptoms, H. pylori is not typically treated.
But if it’s detected in a person with a family history of
gastrointestinal cancers; or when clinical symptoms are
present
H PYLORI TREATMENT
– triple therapy is effective and consists of two
antibiotics. Typically, amoxicillin and clarithromycin,
and proton pump inhibitor
Treating H. pylori infections consists of a macrolide,
amoxicillin, and proton pump inhibitor.
An alternative regimen consisting of metronidazole,
tetracycline, and bismuth salt can be used.
PLESIOMONAS
- Oxidase-positive, glucose fermenting, facultatively
anaerobic, gram-negative bacilli that are motile by
polar flagella - ①
Found in both soil and aquatic environments, but
because of intolerance to increased NaCl and a
minimum growth temperature of 8°C, they are
generally found only in the fresh and estuarine waters
of tropical and subtropical climates
PLESIOMONAS CHARACTERISTIC
Plesiomonads are straight (0.8 to 1 µm by 3 µm),
gram-negative bacilli that occur singly, in pairs, or
in short chains or filamentous forms
They do not form spores or capsules and are motile
by monotrichous or two to five lophotrichous
flagella
The genera Plesiomonas and Shigella share both
biochemical and antigenic features, and plesiomonads often cross-agglutinate with Shigella sonnei, S.
dysenteriae, and even S. boydii—hence the species
name shigelloides
Plesiomonas can be serotyped by somatic O antigens (50
groups) and their flagellar H antigens (17 groups).
Found is soil and aquatic (fresh or estuarine) environments
Does not tolerate increased salt (NaCl) concentration
Minimum growth temperature of 8oC
Like the genus Aeromonas – distributed among both warm-
and cold-blooded animals.
Possess a much lower virulence potential,
with a low symptomatic carriage rate among humans, and
is oxidase-positive
P. shigelloides
PLESIOMONAS CAUSE
o Self-limiting Gastroenteritis: - More common watery or Secretory diarrhea\
o Extra-intestinal
- Bacteremia
- Meningitis
A more invasive, dysenteric firm that resembles
colitis
GASTOENTERITIS
At least three major clinical types of
gastroenteritis are caused by Plesiomonas
o The more common watery or
secretory diarrhea
o A subacute or chronic disease that
lasts between 14 days and 2 to 3
months
o A more invasive, dysenteric form
that resembles colitis
PLESIOMONAS
After 18-24 hours incubation at 35° C, shiny,
opaque, nonhemolytic colonies appear, with a
slightly raised center and a smooth and entire
edge
use of _______can enhance the isolation of plesiomonads
use of inositol brilliant green bile salts
agar can enhance the isolation of plesiomonads
colonies are white to pink on this
medium, and most
Plesiomonas
TREATMENT OF PLESIOMONAS
o Generally resistant to Penicillin
o There are reports of resistance to more than one
aminoglycoside (e.g., gentamicin, tobramycin,
amikacin)
o Quinolones, Cephalosporins & Carbapenems are
effective
