1. Members of the Family Enterobacteriaceae

2. Citrobacter Resembles Salmonella but are ONPG (+) & LDC (-)
Citrobacter species
freundii (UTI, pneumonia, intraabdominal abscess)
diversus (neonatal meningitis)
amalonaticus (extraintestinal infections)
C. freundii S. diversus
H2S
Indole
KCN

3. Klebsiella
Klebsiella -Enterobacter-Serratia-Hafnia K. pneumoniae >Friedlander’s bacilli (encapsulated and mucoid) > (+) String test Klebsiella aerogenes is associated with hospital acquired infections of wounds and of the urinary tract K. rhinoschleromatis – rhinoscleromatis (granulomatous disease of the nose and pharynx with intense swelling and malformation of the entire face and neck)

4. The patient's K. pneumoniae isolate was string test positive (>5 mm string length).

5. LABORATORY DIAGNOSES
Specimens: Depending on the site of infection, specimens
include urine, pus, sputum and infected tissue.
Morphology
Klebsiellae are Gram negative, non-motile, usually
capsulated rods.
Culture
Klebsiellae are aerobes and facultative anaerobes.
Blood agar: Klebsiellae produce large grey white usually mucoid colonies.
MacConkey agar and CLED medium: Most klebsiellae are lactose-fermenting, producing mucoid pink colonies on MacConkey agar and yellow mucoid colonies on CLED medium
K. rhinoscleromatis is non-lactose fermenting.
Biochemical tests
Klebsiellae are indole negative, ornithine decarboxylase negative and do not produce H2S.

6. Klebsiella on CLED medium show yellow lactose fermenting colony
Klebsiella on Macconkey medium show large mucoid pink lactose fermenting colony

7. Enterobacter -species: habitat: soil, water, dairy products
-normal flora of the gut of animals & humans
-motile, ODC & ONPG (+)
LDC ADH ODC Urease Yellow
pigment
E. cloacae V -
E. aerogenes
E. gergoviae
E. sakazakii
E. taylorae

8. Enterobacter

9. Edwardsiella Edwardsiella
tarda (human pathogen – bacteremia and wound infection)
hoshinae (snakes, birds and water)
ictaluri (enteric septicemia in fish)

10. Serratia opportunistic pathogens DNAse, lipase, gelatinase
S. marcescens
S. liquefaciens
S. rubidaea
S. oderifera

11. Serratia

12. Proteus Tow important species , P. mirabilis and P. vulgaris
Morphology
Proteus is actively motile with peritricous flagella , non capsulate, Gram negative pleomorphic rods.
Rapid urease producers
Swarming, burned chocolate odor

13. Proteus with peritricous flagella

14. Pathogenicity P. mirabilis causes:
1- Urinary infections. in the elderly and young males and often following catheterization or cystoscopy..
2- Abdominal and wound infections
3- secondary invader of ulcers, burns and damaged tissues.
4- Septicaemia
5- Meningitis and Chest infections.

15. is electrolyte deficient Biochemical tests
Culture
aerobically, most Proteus cultures have a characteristic ‘fishy’ Odour and Swarming on the medium
MacConkey, CLED, XLD media: non-lactose fermenting colonies after overnight incubation at 35–37 ºC
Swarming is prevented on MacConkey agar and XLD agar because these media contain bile salts.
Swarming is inhibited on CLED agar because it
is electrolyte deficient
Biochemical tests
Do not ferment lactose.
Rapidly hydrolyze urea (within 4 hours), early screening test in differentiating enteric pathogens, e.g. salmonellae and shigellae from Proteus.
Phenylalanine deaminase (PDA), positive.
Indole negative (P. vulgaris is indole positive).

16. Proteus P. mirabilis P. vulgaris Indole - + ODC + - Fermentation
Maltose
Xylose
Salicin
Chloramphenicol S R

17. Proteus P. mirabilis P. vulgaris Indole ……… ……. Maltose ……… …….
Xylose …….. …….
Salicin …….. …….
Chloramphenicol …….. ……

18. Proteus
Proteus McConkey Urease test

19. Swarming on Blood agar
Swarming pehomenon

20. Morganella Formerl known as Proteus M. morganii – only specie
UTI’s and wound infections

21. Providencia
Providencia ( 4 species – P. alcalifaciens, P. Rustigianii, P. rettgeri, P. stuartii)
P. rettgeri P. stuartii
Urease
Citrate

22. Yersinia 11 species Y. pestis (plague) – bipolar staining (wayson)
Agent of bubonic plague, pneumonic and septicemic plagues
Bubonic – bite of infected flea
Pneumonic
Prefered growth at 25 deg C
Y. enterocolitica (acute enteritis – appendictis like)
Pig, cats and dogs
Cold enrichment
Motile at RT
Y. pseudotuberculosis
Pathogen in animals (turkey, geese, doves, farm and domestic animals)

23. Yersinia
Yersinia pestis
Safety pin appearance

24. Revision Question
1- Characteristic of enterobacterceae all of the following except :
a- Gram negative rod
b- Facultative anaerobic
c- Ferment glucose
d- Oxidase positive
2-Sworming is special characteristic of:
a. Pseudomonades
b- Proteus
c- E. coli
d- Klebsiella
3- Mucoid colony is special characteristic of:

25. 4- Bacteria which give green metallic sheen on EMB medium is:
a. Pseudomonades
b- Proteus
c- E. coli
d- Klebsiella
5- Polysaccharide capsule present on which of the following bacteria:
c- Shigella
6- Which of the following bacteria is urease positive :
7- Which of the following bacteria is lactose fermenter:

26. When we inoculate members of enterobacterceae on MacConkey agar, mention which organism grow producing lactose fermentor colony and which grow producing lactose fermentor colony

27. الهم لا تجعل الدنيا اكبر همنا و لا مبلغ علمنا
klebsiella and e.coli
الهم لا تجعل الدنيا اكبر همنا و لا مبلغ علمنا