Gram Negative Bacilli Family Enterobacteriaceae Genus Proteus Species

Gram Negative Bacilli Family: Enterobacteriaceae Genus : Proteus Species : Proteus Mirabilis, Proteus Vulgaris

Genus : Proteus General Characteristics: G – ve, pleomorphic bacilli. Non – lactose fermenter Ferment glucose and produce acid + gas. Facultative anaerobes. Highly motile. Grow as swarms (waves) on blood agar (swarming phenomenon). Fishy smell on culture. Urease +ve N. f. of human GIT.

Genus : Proteus DISEASES: UTI, Stone formation form stone. Wound infection. Pneumonia. Sepsis. (alkaline urine)

Genus : Proteus Swarming inhibition: 1. Medium with surface active agent: e. g. Bile salt in Mac. Conkey agar. 2. Increases agar concentration (5%). Advantage: regarded as a diagnostic feature for Proteus. Disadvantage: can causes misdiagnosis for other bacteria.

Genus : Proteus LABORATORY DIAGNOSIS: Specimens according to disease e. g. in Ø UTI urine. Gram stain Gram’s negative bacilli. Ø Culture: Ø *Mac. Conkey’s agar non lactose Pale colonies.

Laboratory diagnosis *Blood agar Swarming.

Laboratory diagnosis *Glucose sugar fermentation acid &gas *Urea agar (urease test) Pink (+); Yellow (-) ØMotility test positive inverted Christmas tree Ø API 20 E (biochemical test)

Genus Pseudomonas Species: Pseudomonas aeruginosa.

Genus Pseudomonas GENERAL CHARACTERISTICS G-ve bacilli, non – lactose fermenter. Ferment glucose and produce acid only. Strictly aerobic, oxidase positive Fruity (sweet) smell on culture. (green apple smell) Produce water - soluble pigments: Pyocyanine Blue – green. Pyorubrin Red. Pyoviridin Fluorescence. Pyomelanin Black. Actively motile , N. f. of soil, water, plants, hospital environment (sinks, showers, respiratory equipments).

Genus Pseudomonas Pyocyanine Pigment

Genus Pseudomonas Pyocyanine Pigment

Genus Pseudomonas TRANSMISSIONS: Ingestion of water & food. Contaminated medical equipments. Contamination of wounds. Person to person.

Genus Pseudomonas Diseases: Community acquired infections: Skin (folliculitis), eye infection after trauma, osteomyelitis after trauma, pneumonia. Nosocomial infections: Wound infection. UTI. Burn infection. Otitis externa. Pneumonia. Sepsis. Highly resistant to antibiotics and disinfectant.

Genus Pseudomonas pseudomonas infection

Genus Pseudomonas LABORATORY DIAGNOSIS: - 1 -Specimens (according to the type of infection) e. g. wound swab…etc. 2 -Gram’s stain cylinder, Gram’s negative bacilli. 3 -Culture: Aerobic, 37 C° on: a. ) Mac. Conkey’s agar Non lactose fermentation Pale colonies.

Laboratory diagnosis b. ) Nutrient agar Demonstrate pigment production.

Laboratory diagnosis c. ) Blood agar spreading flat pigmented, sometime with Beta- hemolysis, mucoid, confluent growth.

Laboratory diagnosis 4 -Biochemical tests: Oxidase test, catalase test all are positive. Catalase +ve Oxidase +ve

Laboratory diagnosis 5 - Glucose sugar fermentation acid but no gas. 6 -Motility test: positive inverted Christmas tree. 7 -Antibiotic sensitivity: very important as this bacteria is multidrug resistance.

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