Microbiology Gram-negative rods: Glucose nonfermenting Karen Honeycutt, M.Ed., MT(ASCP)SM MT 418 Clinical Microbiology Student Laboratory Session

Microbiology General Information Predominantly opportunistic Debilitated host Nomenclature changes rapidly (usually known by 2 names for 5-10 years) Will grow on BAP, 22-35°C, hours Categories based upon: glucose, oxidase & ability to grow on MAC GNR: Glucose nonfermenters

Microbiology General Information Gram stain morphology taken from non- inhibitory agar Can be difficult to treat, can rapidly develop antibiotic resistance to drugs used for treatment GNR: Glucose nonfermenters

Microbiology Glucose “O”, oxidase +, MAC + Pseudomonas sp. –Pseudomonas aeruginosa most commonly isolated nonfermenting GNR Grows in moist environments (soap) Aerobic Motile w/polar flagella GNR: Glucose nonfermenters

Microbiology Pseudomonas aeruginosa Nosocomial infections Usually not part of normal flora Colonization can occur (upper respiratory tract, skin, GI tract) Produces pigment –Pyocyanin –Pyoverdin –Pyomelanin –Pyorubrin GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Pseudomonas aeruginosa infections Cystic fibrosis patients – serious lung infections Immunosuppressed Burn wounds Osteomyelitis UTI, septicemia, Corneal ulcers (blindness) Swimmer’s ear, folliculitis GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Pseudomonas aeruginosa Id Glucose OF = “O” Oxidase BAP MAC GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Pseudomonas aeruginosa Id Oxidase BAP Rapid ID Rough & beta-hemolytic on BAP Pigment Grape-like smell GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Pseudomonas aeruginosa Id Oxidase BAP Pigment production: Pyoverdin (fluorescent) Pyocyanin(blue) Pyomelanin (brown) Pyorubrin (red) Pyoverdin (fluorescent) + Pyocyanin (blue)= green or metallic sheen on BAP, CHOC GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Pseudomonas aeruginosa Id Moeller base decarboxylase/dehydrogenase Arginine + Ornithine (-) Lysine (-) Glucose “O” Green pigment GNR: Glucose “O”, Oxidase +, MAC +

Microbiology Glucose “O” or “I”, oxidase (-), MAC + Stenotrophomonas maltophilia –Strong maltose oxidizer Nosocomial Opportunistic 3 rd most common glucose non-fermenter isolated in clinical lab GNR: Glucose nonfermenters

Microbiology Stenotrophomonas maltophilia BAP: may produce a pale yellow to lavender pigment Oxidase negative Arginine (-), Ornithine (-), Lysine (+) DNase (+) Polymyxin B = “S” GNR: Glucose “O” or “I”, oxidase (-), MAC +

Microbiology Glucose “O” or “I”, oxidase (-), MAC + Acinetobacter sp. 2 nd most common glucose non-fermenter isolated in clinical lab Nosocomial Opportunistic Normal flora: skin, vaginal tract GNR: Glucose “O” or “I”, oxidase (-), MAC +

Microbiology Acinetobacter sp. Gram stain morphology: plump gnr in pairs (can be mistaken for GNDC) Oxidase (-) Nitrate reduction (-) Glucose –“O” Acinetobacter calcaaceticus/baumannii –“I” Acinetobacter lwoffii GNR: Glucose “O” or “I”, oxidase (-), MAC +