1. Proteus Providencia Morganella

2. Family : Enterobacteriaceae Tribe I – Escherichiae Tribe II – Edwardsielleae Tribe III- Salmonelleae Tribe IV- Citrobactereae Tribe V – Klebsielleae Tribe VI- Proteeae Tribe VII- Yersinieae Tribe VIII- Erwinieae

3. Family Tribe Genera Enterobacteriaceae Proteeae Proteus Morganella
Providencia

4. General characteristics
PPA positivity
Motile and lactose nonfermenter
Fishy odor
Part of commensals in human intestine .

5. PROTEUS
Gram negative
Non capsulated
Pleomorphic
Motile rods

6. Possess somatic O
Flagellar H antigens
H antigen : ability of flagellated strains of Proteus to grow on agar as thin film (from Greek word Hauch – film of breath)
O antigen : (Ohne Hauche- without film of breath)thin film is not observed when strains have only somatic antigen.

7. Basis of Weil Felix Reaction
Somatic antigen of certain non motile Proteus strains (X strains)cross react with alkali stable antigen of some Rickettsia species.
To detect heterophile antibodies in sera of patients suffering from Rickettsial infections.
Three non motile Proteus strains : OX2, OX19 and OXK

8. Widely distributed in nature as saprophytes.
Commensals – moist areas of skin, intestine of humans, animals.
Opportunistic pathogens- urinary and septic infections
Nosocomial outbreaks
Struvite stones in bladder

9. LAB DIAGNOSIS
Specimens collected: Depends on the type of infection.
Suppurative lesion- Pus
Urinary symptoms –urine
Bacteremia & septicemia- Blood

10. Methods of examination:
I) Direct microscopy:
Direct microscopy with Gram stained smear shows gram negative coccobacilli.

11. II) Culture:
a) Media used: Blood agar, MacConkey agar , CLED agar
b) Cultural Characteristics:
Blood agar – Swarming is observed with characteristic putrid fishy odor
MacConkey agar- smooth ,colorless colonies

12. Gram staining: Smears are examined from the culture plate and reveals Gram negative coccobacilli.

13. d)Biochemical Reactions :
Indole positive – P.vulgaris / negative – P.mirabilis
MR positive and VP negative
Citrate variable
Urease positive
TSI – K/A,gas,H2S
CATALASE TEST
OXIDASE TEST

15. III) Antibiotic sensitivity tests done as a guide to treatment.
IV)Typing of Proteus –
Bacteriocin typing
Bacteriophage typing
Dienes phenomenon

16. DIENES PHENOMENON
When two strains of Proteus are inoculated on two different areas on culture plate:
If swarming of two strains merge incompletely, remain separated by line of demarcation – two strains are different.
If swarming of two strains merge completely, without any line of demarcation – two strains are identical.

17. Morganella M.morganii Commonly found in human and animal feces
Rarely associated with UTI, pneumonia and other nosocomial infections.
Doesnot swarm in culture.
Indole, urease positive but citrate negative
TSI- K/A+gas ,No H2S

18. Providencia
Associated with nosocomial infections of urinary tract, wounds and burns.
Five species:
P.rettgeri
P.stuartii
P.alcalifaciens
P.rustigianii
P.heimbache

19. P.rettgeri and P.stuartii-common pathogens
Motile but donot swarm

20. Swarming
Characteristic feature of most isolates of Proteus spp. in which a group of cells at the edge of a developing microcolony migrate to an uninoculated area of the medium.
Example of ‘quorum sensing’in which the initiation and regulation of transcription of particular genes occurs only when a critical cell density is reached.

21. Swarming appears in two patterns :
Continuous swarming
Discontinuous swarming

22. MECHANISM OF SWARMING:
During an incubation period of about 2–4 h at 37C, the bacterial cell, which is in the form of a sparsely flagellate,short (2–4 µm) bacillus, referred to here as a vegetative cell, receives a number of extracellular and intracellular signals--- - become multinucleatwed,densely flagellatednonseptate elongated cells (20- 80um)in length---swarm cells
Swarm cells migrate to surrounding uninoculated areas resulting in spreading the colonies.

23. ANTI- SWARMING AGENTS :
Increased agar concentration to 6%
Incorporation of alcohol,boric acid 0.1%, chloral hydrate, sodium azide, sulphonamide, surface active agents,bile salts (interfere with the structure or activity of flagella)
p-nitrophenylglycerol,which at low concentrations inhibits the formation of swarm cells without affecting the formation or motility of flagella

24. Organisms exhibting swarming:
Proteus mirabilis and P.vulgaris
Serratia marcescens
Vibrio parahemolyticus
Clostridium tetani

25. Treatment Often multidrug resistant. Resistant tomany disinfectants
Intrinsic resistance to nitrofurantoin, tetracycline and polymyxin
Resistant to most β lactam drugs
Aminoglycosides and quinoles are effective
In general, P.mirabilis is more susceptible to antibiotics.

26. THANK YOU