Proteus Bacilli

Proteus bacilli – Dr. Tanmay Mehta Tribe Prot eeae : Proteus Morganella Providencia Commo n characteri stics : 1. Proteus = Pleomorphism (Greek God Proteus who could assume any shape) 2. Gram negative – Nonc apsulated – Pleomorphic – Motile Bacilli (peritrichous flagella) 3. Lactose (Dulcitol /Malonate) Nonfermenter : Not strictly belong to coliform bacilli 4. Urease Positive (except Providencia) : hydroly se urea to ammonia and CO2 5. Characteristic feature differentiating Proteeae from other enterobacteria : PPA Positive : Phenyl alanine deaminase – coverts phenyl alanine to phenyl Pyruvic acid 6. Resistant to KCN 7. Degrade Tyrosine 8. Do not form ar ginine/lysine decarboxylase or Beta galactosidase 9. IMViC : V / + / - / + (Pr. Mirabilis is indole negative – rest all are indole positive/ morganella is citrate negative) Genus : Proteus : Normal intestinal commensal & opportunistic pathogens like coliforms 1. P r. Mirabilis – urinary & nosocomial pathogen ( indole negative ) 2. Pr.vulgaris – less common in human infection (indole positive ) Culture on Nutrient agar : Facultative anaerobic Characteristic fishy /seminal putrefying odor – with Swarming Discrete colonies in young culture actively motile cells spread on surface of plate in successive waves form thin filmy layer in concentric circles Disadvantage of swarming : it is a problem when mixed growth is obtained in which proteus is contaminant Methods to inhibit swarming (in mixed growth) : 1. Increase co ncentration of agar to 6% 2. Chlor hydrate (1:500) 3. Sodium azide (1:500) 4. Alcohol 6% 5. Sulfonamides 6. Surface active agents 7. Boric acid (1:1000) Swarming does Not occur on : MacConkey Agar (smooth colonies are found) : Lactos e non fer menter Oxidase negative – catalase positive IMViC: +(vulgaris) – (mirabilis) /+/-/+ PPA & Urease positive Genus : Morgenella M morganii (Pr.morganii) – found in feces – infrequent UTI- nosocomial wound infection : Not swarm on culture PPA positive IMViC : + / + / - / - (citrat e neag ative ) Urease positive G enu : Prov iden cia Prov. Alcalifaciens : in normal feces & diarrheal stools Prov. Stuartii : UTI – Burn infection Prov. Rettgerii : nosocomial infection of Urinary tract – wounds – burns – blood PPA positive IMViC : + / + / - /+ (citrate positive) Urease negative\ Antibiotics proteus bacilli ate resistant to many antibiotics : Providencia is most resistant – Prov.Stuartii also resistant to disinfectants [chlorhexidine , cetrimide , benzalkonium chloride ]& heavy me tal compounds like silver sulfadiazine (major pathogen in burns) Exception : Pr.mirabilis – sensitive to ampicillinand cephalosporins Sensitive to : Phe nol & glu tarldehyde - Amikacin & Ciprofloxacin Weil & Felix : Strains of proteus on agar Form a surface film r ese mbling mist produced by breathing on glass – named Hauch (= film of breath) : Flagellar H strains Colonies without a surface film – Ohne Hauch (without film of breath) : only somatic O antigens Bacterial agglutination H type : loose fluffy masses (d ue to flagellated cells agglutination) O type : fine granular (due to somatic agglutination) Nonmotile strains of pr.vulgaris = X strains (OX2 , O X19 , OXk) – share carbohydrate haptens with rickettsia : basis o f heterophile agglutination Weil felix reaction for diagnosis of ricketssial infection

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8/4/2019 Proteus Bacilli

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Proteus bacilli – Dr. Tanmay Mehta Tribe Proteeae :

Proteus Morganella Providencia

Common characteristics :1. Proteus = Pleomorphism (Greek God Proteus who could assume any shape)2. Gram negative – Noncapsulated – Pleomorphic – Motile Bacilli (peritrichous flagella)3. Lactose (Dulcitol /Malonate) Nonfermenter : Not strictly belong to coliform bacilli

4. Urease Positive (except Providencia) : hydrolyse urea to ammonia and CO25. Characteristic feature differentiating Proteeae from other enterobacteria : PPA Positive : Phenyl alanine deaminase – coverts

phenyl alanine to phenyl Pyruvic acid6. Resistant to KCN7. Degrade Tyrosine8. Do not form arginine/lysine decarboxylase or Beta galactosidase9. IMViC : V / + / - / + (Pr. Mirabilis is indole negative – rest all are indole positive/ morganella is citrate negative)

Genus : Proteus : Normal intestinal commensal & opportunistic pathogens like coliforms1. Pr. Mirabilis – urinary & nosocomial pathogen (indole negative )2. Pr.vulgaris – less common in human infection (indole positive ) Culture on Nutrient agar :

Facultative anaerobic

Characteristic fishy /seminal putrefying odor – with Swarming

Discrete colonies in young culture actively motile cells spread on surface ofplate in successive waves form thin filmy layer in concentric circles

Disadvantage of swarming : it is a problem when mixed growth is obtained inwhich proteus is contaminant

Methods to inhibit swarming (in mixed growth) :1. Increase concentration of agar to 6%2. Chlor hydrate (1:500)3. Sodium azide (1:500)4. Alcohol 6%5. Sulfonamides

6. Surface active agents7. Boric acid (1:1000)

Swarming does Not occur on : MacConkey Agar (smooth colonies are found) : Lactose nonfermenter

Oxidase negative – catalase positive IMViC: +(vulgaris) – (mirabilis) /+/-/+ PPA & Urease positive

Genus : Morgenella M morganii (Pr.morganii) – found in feces – infrequent UTI-

nosocomial wound infection : Not swarm on culture PPA positive

IMViC : + / + / - / - (citrate neagative ) Urease positive

Genu : Providencia Prov. Alcalifaciens : in normal feces & diarrheal stools Prov. Stuartii : UTI – Burn infection Prov. Rettgerii : nosocomial infection of Urinary tract –

wounds – burns – blood PPA positive IMViC : + / + / - /+ (citrate positive) Urease negative\

Antibiotics proteus bacilli ate resistant to many antibiotics : Providencia is most resistant – Prov.Stuartii also resistant to disinfectants

[chlorhexidine , cetrimide , benzalkonium chloride ]& heavy metal compounds like silver sulfadiazine (major pathogen in burns) Exception : Pr.mirabilis – sensitive to ampicillinand cephalosporins Sensitive to : Phenol & glutarldehyde - Amikacin & Ciprofloxacin

Weil & Felix :Strains of proteus on agar Form a surface film resembling mist

produced by breathing on glass – namHauch (= film of breath) : Flagellar Hstrains

Colonies without a surface film – OhnHauch (without film of breath) : onlysomatic O antigens

Bacterial agglutination H type : loose fluffy masses (due to

flagellated cells agglutination) O type : fine granular (due to somatic

agglutination)

Nonmotile strains of pr.vulgaris = X strain(OX2 , OX19 , OXk) – share carbohydratehaptens with rickettsia : basis of heteropagglutination Weil felix reaction for diagnof ricketssial infection