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 GNR: Glucose nonfermenters 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, 24-72 hours Categories based upon: glucose, oxidase & ability to grow on MAC Microbiology

GNR: Glucose nonfermenters 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 Many genera Commercial system reliability? Microbiology

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

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

P. aeruginosa - Pigments GNR: Glucose “O”, Oxidase +, MAC + P. aeruginosa - Pigments Usually produces Pyoverdin (fluorescein) – yellow/green; visualize with UV light; Other Pseudomonas sp. can also produce Pyocyanin – blue-green pigment; only produced by P. aeruginosa May produce Pyorubrin – pink to red/maroon pigment; only produced by P. aeruginosa Microbiology

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

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

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

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

Pseudomonas aeruginosa infections GNR: Glucose “O”, Oxidase +, MAC + Pseudomonas aeruginosa infections Corneal ulcers (blindness) Photo from Images.MD Microbiology

Pseudomonas aeruginosa infections GNR: Glucose “O”, Oxidase +, MAC + Pseudomonas aeruginosa infections Burn wound Photo from Images.MD Microbiology

Burkholderia cepacia Nosocomial infections GNR: Glucose “O”, Oxidase +/-, MAC + Burkholderia cepacia Nosocomial infections CF patient – colonized/infected with: severe social ramifications; person to person spread established Some CF – once infected with: fulminant decline of pulmonary function Resistant to many antibiotics Microbiology

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

Stenotrophomonas maltophilia GNR: Glucose “O” or “I”, oxidase (-), MAC + Stenotrophomonas maltophilia BAP: may produce a pale yellow to lavender pigment Oxidase negative Arginine (-), Ornithine (-), Lysine (+) DNase (+) Polymyxin B = “S” Disk diffusion susceptibilities now standardized (SXT “S” – drug of choice) Microbiology

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

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