Download Enteric Bacteria

Enteric Bacteria
Prof. Dr. Asem Shehabi
Faculty of Medicine
University of Jordan
Enteric Bacteria
• General Characteristics: Gram-ve Bacilli, Facultative
Anaerobes, Oxidase-negative.. Part Intestinal Normal
Flora.. Humans, Animals, Birds.. Common Waste water,
Natural Water, Soil, Vegetation.
• Opportunistic Pathogens/Obligate Pathogens..
Enterotoxins, Endotoxins, Capsules, Flagella, Pili
• Coliform Group:
1. Escherichia coli: Urinary Tract Infect (40-70%)..Single
Organism, Septicemia, Neonatal Meningitis, Wounds.
Diarrheagenic E coli strains:
- Enteropathogenic:Infants.. mild-chronic diarrhea,
Enterotoxigenic.. Heat-Labile/Stable Enterotoxin, Watery
diarrhea.. More Children than Adults.. Travelers
diarrhea..Contamination Water/Vegetables / Fresh food
Coli-form group-2
dairy products ..Mostly Self-limited.. No need for Antibiotics
treatment.
- Enterohaemorrhagic .. Common in intestinal Cattels,
verotoxins.. Contamination Ground meat/Hamburger,Dairy
products..Bloody diarrhea.. Haemolytic-ureamic syndrome,
pertonitis, Kidney failure..Outbreaks of infections.
• E. coli is used as indicator for detection of water & Food fecal
contamination.
2. Klebsiella-Enterobacter –Serratia species: UTI, Septicemia,
Wounds.. Rare Meningitis.. Common Hospitalized patients.
• K. pneumoniae.. Large polysaccharide.. capsule.. Nosocomial
Pneumonia.
E. coli Culture – Red color on MaConkey agar
indicates Lactose-positive & Gram-stain
E.coli-Flagella-Fimbriae-Pili
Klebsiella pneumonia-Capsule
Coliform group-3
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E.coli, Klebsiella-Enterobacter –Serratia spp..
Lactose+ve , urease-ve & oxidase-negative..
• Klebsilla spp. often encapsulated.. Non-motile
• 3. Proteus-Providencia-Morganella species:
Lactose-ve & urease positive.. cause UTI,
Septicemia, Wounds.. Commonly in
Hospitalized patients.
• Lab Diagnosis: All Enteric bacteria grow on
MacCokeny-, Blood-, CLED-agar. Full
identification done using Biochemical Tests..
Antibiotic Susceptibility must be done.
4. Pseudomonas group
• Gram-ve bacilli, Oxidase-positive, Single polar
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flagellum,Fimbriae, obligate aerobe, widely distributed
in human intestine, animal, plants, environment &
water. Survive in disinfection solutions.. 70%
Alcohol..contaminate Hospital sinks & equipments.
P. aeruginosa: Most common causes of human &
animal infections.. Produce several hemolyticprotolytic enzymes, toxins, fluorescent pigmentspyocyanin / Burn-Blue Green Pus.. can overcome host
defenses.. Wounds,, External Otitis Media, Septicemia,
Pneumonia, UTI, Nosocomial Infection, Mutlidrug
Resistance.. Intrinsic-R to many antibiotics..Common
Nosocomial/ opportunistic Pathogen.
5-Salmonella group
• Gram-ve bacilli.. Lactose-ve, urease-ve, Motile,
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Facultative Anaerobes.. Endotoxin/LPS, Cytotoxin..
common in Nature.. Humans, most domestic & wild
Animals, Birds, Reptiles ..Develop of specific
antibodies during invasive infection against their O/HAntigens..
Salmonellosis:
1-Gastroenteritis/ Food-poisoning Salmonella: S.
enterica/ enteritidis.. Numerous Serotypes.. Common
Farm Chickens, Pets.. Contamination Chicken MeatEggs, Water.. Fecal-Oral Infection.. Incub. 8-24 h..
Mild-Severe Diarrhea, Vomiting, Fever.. Mostly SelfLimited in Adults. More severe infection in children..
Septicemia-Meningitis in Immuno-compromised Pat.
V. cholerae – Salmonella/ Flagella
Hekton–Enteric agar for Isolation of
Salmonella (E.coli-Salmonella growth)
Typhoidal Salmonella
2- Typhoidal Salmonella: Human Enteric Fever..
Salmonella enterica /subtype Typhi & Paratyhi A, B,
C., Fecal-Oral route, Fecal water contamination or
drinks/ Fresh Food.. Intestine..Blood, Meningis,Urinary
tract.. Incubation Period 1-3 Weeks, high Fever
up to 42, Diarrhea, constipation, Septicemia,
Meningitis, Hepatospenomegaly, Intestinal
Perforation.. Healthy Carriers.. Mostly females in
Gallbladder.. Less Intestine.. Repeat chronic infection..
Stool Excretion..single cases and community water
outbreaks.
• Lab Diagnosis: Culture Feces, blood, Urine, CSF, Selective
Media.. Serological Widel Test for detection of specific
antibodies against O & H antigens ( Titer > 160 ).. Antibiotic,
Human vaccine available.
6-Shigella group
• Shigella species.. Gram-ve bacilli, cause Only human
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disease.. Endo/Enterotoxins.. Susceptible to Dryness,
Acid, Low-High Tempt. Fecal-Oral infection.. Water,
fresh Vegetations, Common serotypes, S. Sonnei,
Sh.boydii Sh. flexneri Purulent-BloodyDiarrhea..Fever abdominal pain..Recovery 2-4 days
with treatment.. No chronic healthy Carriers.
S.dysenteriae.. Enterotoxin (Neurocytotoxin), Severe
Necrosis, high Fever, Severe Purulent-Bloody-Diarrhea
& Abdominal Cramps, CNS affection.. Rare Septicemia.
Lab Diagnosis: Feces Culture.. S-S Agar, Hecton –
Enteric Agar.. Recommended Antibiotic Treatment,
Control Sanitation & hygiene.. water, fresh Food.
7-Vibrio cholerae
• Gram-ve Vibrios.. Oxidase-positive & Motile, Aerobic
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Alkaline Medium (pH >8-9)..Killed in low acidity..
Survive in saline water for long time.. Endemic In
India/Bangladish.. Highly infectious.. Epidemic Human
Outbreaks.. Water, Fresh Green leaves & Food
V. cholera-01: Type V. cholera El-Tor.. Only Human..
Fecal-Oral Infection, multiply small intestine..release
Cholera-toxin.. Heat-labile enterotoxin, Incub. 8-48 h..
Severe Watery Diarrhea, Dehydration, Shock.. Death.
Within 24 hrs..No invasive infection.
Lab Diagnosis: Feces Culture.. Selective TCBS agar.
Treatment: Replacement Fluids & Electrolytes..
Antibiotic.. Public Heath Measurements.. Human
Vaccine recommended for Refuges & Army.
Cholera
TCBS agar for isolation of V.cholerae/
Salmonella–Shigella agar (Lactose-negative)
8-Brucella species
• Brucellosis/Malta Fever.. Gram-ve coccobacilli..Non-
motile, Intracellular, Endotoxins.. Primarily a
Pathogens of Animals (Zoonosis), Localized Infection
in reproductive Organs.. Sepsis, Abortions.
• Br. abortus (Cattel), Br. melitensis (Goats/Sheep).
• Human Brucellosis/Malt Fever : Mostly Br. melitensis..
Rare Other species in Jordan.
• Transmitted to Humans.. Unpasteurized Milk/Milk
Products.. Cheese, Direct Animal Contact.. Few Cells
Enter Through GI, Skin Abrasions, Eye,
Inhalation/Droplets.. Intracellular ..Lymphatic System..
Septicemia, Meningitis, Chronic disease
Brucella-2
• Clinical Features: Incub. 1-6 Weeks.. Intermittent
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fever, headaches, fatigue, joint and bone pain, GI
Symptoms, Sweats, Back Pains, Acute- SubacuteChronic Infections.
Common Complications: Arthritis, Meningitis-CNS,
Osteomylitis, Localized Lesions in any body part.
Lab Diagnosis: Culture Blood, CSF, Bone marrow
(Chronic Infection).. Brucella agglutination Test..
Specific Antibodies
Treatment: 6-8 Weeks with Antimicrobial drugs
Prevention: Control Brucella in Animals by
slaughtering infected animals .. Animal Vaccination,
Pasteurization Milk/ Milk Products
9-Campylobacter Species
• Campylobacter jejuni , is Gram-negative slender,
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curved, motile by one/ two polar Flagellium, Spiral
form, Grow Microaerophilic at 37-42..Normal
Intestines flora all Birds, Animal..dogs, cats..
contaminated often Chicken Meat, Milk, food, water.
It is primarily an animal pathogen causing abortion
and enteritis in sheep and cattle.
Common cause of food-poisoning, important enteric
pathogen since 1976.. In Western Countries.
C. jejuni .. Incubation 2-5 days..release Cytotoxins..
Intestinal inflammation..causes mild-moderate bloodywater diarrhea, Children.. , Other symptoms often
present are fever, abdominal pain, nausea, headache
and muscle pain..Rare Sepsis & complication Arthritis,
Diagnosis: Stool culture .. Selective culture Media
Cambylobacter Cell morphology
10-Helicobacter Species
• Helicobacter pylori is a spiral shaped
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bacterium..One polar flagella.. Colonize only mucus
lining cover mucosa of Gastric Antrim.. and
duodenum.. Produce extensive Urease..Split urea to
Ammonia..release Cytotoxin.. Mild-sever ulceration
The stomach is protected from its own gastric juice by
a thick layer of mucus that covers the stomach lining.
Helicobacter colonize and infect only humans
worldwide, where up to 10% of children & 80% of
adults can have evidence of an H. pylori infection usually without having any clinical signs or symptoms.
Helicobacter
Helicobacter Species-2
• Common symptoms: gastritis or peptic ulcer
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/Stomach.. duodenal ulcers ..burning, Abdomen Pain,
Nausea, Vomiting.
Persistence of ulcers .. Development of Stomach
Cancer and Lymphoma..1-3%
H. pylori can be successfully eradicated using a
combination of certain antibiotics and medicines that
suppress stomach acid production. Common Reoccurrence of infection & disease
Diagnosis: Urea Breath Test, Culture Stomach Biopsy..
Culture on Selective Medium.. 42C..
Serological test for specific antibodies is not significant