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ENTEROBACTERIACEAEENTEROBACTERIACEAE

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EnterobacteriaceaeEnterobacteriaceae

Large family of gram Negative rodsLarge family of gram Negative rods

Free living in nature, part of indigenous flora of humansFree living in nature, part of indigenous flora of humans

and animals.and animals.

All areAll are

FacultativeFacultative anarobesanarobes

Ferment glucoseFerment glucose

Oxidase NegativeOxidase Negative

Grow rapidlyGrow rapidly Many are motile (exceptMany are motile (exceptKlebsiella, ShigellaKlebsiella, Shigella) w/) w/

((peritrichousperitrichous flagella)flagella)

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EnterobacteriaceaeEnterobacteriaceae (Continued)(Continued)

They are the most common leading cause ofThey are the most common leading cause ofUrinary tract infection and acute diarrhea.Urinary tract infection and acute diarrhea.

Some are encapsulated (Klebsiella)Some are encapsulated (Klebsiella)

Antigenic Structure:Antigenic Structure: (Imp. in identification)(Imp. in identification)

Cell wall LPSCell wall LPS O antigenO antigen

CapsuleCapsule K antigenK antigen

FlagellarFlagellar H antigenH antigen

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EnterobacteriaceaeEnterobacteriaceae (Continued)(Continued)

Habitat:Habitat: (Normal Colonic flora)(Normal Colonic flora)11-- Lower gastrointestinal tract (GIT)Lower gastrointestinal tract (GIT)

(Colon) of human al animals.(Colon) of human al animals.

E.g.E.g.E.coli, Klebsilla, Proteus, EnterobacterE.coli, Klebsilla, Proteus, Enterobacter22-- Female genital tractFemale genital tract

33-- Transient colonization of skinTransient colonization of skin

44-- URT of hospitalized patients.URT of hospitalized patients.NB: Salmonella, Shigella, Yersinia are intestinal pathogensNB: Salmonella, Shigella, Yersinia are intestinal pathogens

(not normal flora).(not normal flora).

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EnterobacteriaceaeEnterobacteriaceae(Continued)(Continued)

Classification: Cultural, Biochemical

E.g. Indole production (E.coli) H2S (Salmonella)

Lactose fermentation (pink colories on MacConky

agar)

Most spp. produce pink colories except.

(Salmonella Shigella Yersinea)

(Non lactose fermenters) LF

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E.coliE.coli

Most common colonic floraMost common colonic flora Lactose fermenterLactose fermenter

Produce indoleProduce indole

Many serotypes (O,K,H antigens) (>150)Many serotypes (O,K,H antigens) (>150) HemolysinsHemolysins, capsule, pilli (P attachment) to EPC, capsule, pilli (P attachment) to EPC

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E.coliE.coli (Continued)(Continued)

11-- UTI Infections:UTI Infections:

>90% of UTI, Cystitis (bladder) Pydonephritin (Renalpelvis .

Women

Children Elderly

Risk Factors:

TraumaTrauma

CatheterCatheter

Obstruction to outflow (prostate)Obstruction to outflow (prostate)

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E.coliE.coli (Continued)(Continued)

22-- Intestinal Infection (GIT)Intestinal Infection (GIT)

4 main groups

1-Enteropathogenic (EPEC)

Important cause of infantile diarrhea (

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E.coliE.coli (Continued)(Continued)

33-- Enterotoxigenic (ETEC)Enterotoxigenic (ETEC)

Transmitted through Cattle under cooked beef

E.coli O157:H7

Bloody diarrhea (Childhood) 10 days after

Hemolytic uremic syndrome (HUS)- hemolytic anemia

- thrombocytopenia

- Renal failure (life threatening)

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E.coliE.coli (Continued)(Continued)

44-- Enteroinvasive (ETIEC)Enteroinvasive (ETIEC)

Treatment & Prevention: Proper waste disposalProper waste disposal

Clean water supplyClean water supply

Avoid ice. salads. raw vegetables for travellersAvoid ice. salads. raw vegetables for travellers

Hand washingHand washing

TreatmentTreatment

DiarrheaDiarrhea

Most are self limitingMost are self limiting

RehydrationRehydration

-- OralOral

-- Parenteral (IV)Parenteral (IV)

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E.coliE.coli (Continued)(Continued)2- UTI.

i) fluid intaki) fluid intakii) Antibioticsii) Antibiotics

e.g.e.g. -- ampicillin (R )ampicillin (R )

--

Cotrimoxazol. (Septrin)Cotrimoxazol. (Septrin)

-- CephradinCephradin

-- CiprofloxacinCiprofloxacin

Other infections caused byOther infections caused byE.coliE.coli

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E.coliE.coli (Continued)(Continued)3- Meningitis

Most common cause of Neonatal among E.coli K1Most common cause of Neonatal among E.coli K1

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KlebsiellaKlebsiella::

Non motile LF

Capsule (mucoid)

Cause UTI pneumonia

species

- K. aerogens

- K. pneumoniae

Most resistant to antimicrobial agents (MDR) intrensic R to

ampicillin.

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EnterobacterEnterobacter:: Lactose fermenter

Motile

R to common agents except 2nd and 3rd Ceph.

Proteus, Morganella, Providensia NLF Swarming urease +ve

Produces UTI + Stone formation

Serratia

Citrobacter

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ShigellaShigella

(Cause of bacillary dysentry)

(acute inflammatory colitis) + bloody diarrhea

NLF

No gas production Non motile

4 Main Species

A- S.dysenteriaeB- S. flexneri

C- S. bodyii

D- S. sonrei

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EpidemiologyEpidemiology::

Pediatric disease (

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TreatmentTreatment::

Usually self limiting

Indicated to shorten illness and decrease excretion oforganism decrease spread of infection.

Antibiotics:

Qunelons (Cipro)

Cephtriaxon ampicillin (R )

Septrin

Prevention:

Avoid contaminated water, food Hand washing

Insects control

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Salmonella (Intracellular, Organism):Salmonella (Intracellular, Organism):

NLF

Produce gas and H2S

Motile

>1500 Spp. in human and animals

Infections:

1- Gastroenteritis (food poisoning )

2- Typhoid fever

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1) Gastroenteritis:

Zoonotic disease (animal born) through

Poultry (Chicken)

Eggs

Mainly due to improper handling of food and water Main species

S.typhimurium

S.enteritides

Children & elderly patients with achlorhydria ( acids) aremost susceptible.

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Clinical

Nausea,vomiting diarrhea (bloody) + fever within (IP) 2444 h

Self limiting

No systemic involvement OR blood stream infection.

No prolonged carriage.

2) Typhoid fever (enteric Fever)

Restricted human disease (no animal source)

Water born Liver

Systemic blood stream infection involving RES lymph nodes-spleen

Kidney

Associated with carrier state chronic carrier (source ofinfection) + contamination of water with human waste.

Communicable (fecal oral routes) infection + person - person

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Etiology

Salmonella typhi typhoid fever (most fever)

S.paratyphi A

B Paratyphoid fever (less fever)

CClinical

Fever (most important) + chills. Headache, bradicardia.

Rash ( rose spots ) - constipation IP. (2 Wks.) (14 days)

Performation

Hemorrhagic Chronic carriage in gall bladder & urinary tract.

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