Non-Fermenters Presentation PDF

Non-fermenters Hannah Reilly MS, MLS, PA (ASCP)  Characteristics of Non- Fermenters Do NOT ferment glucose TSI reaction is K/K Many are oxidase positive Slower growing than Enterobacteriaceae Some grow poorly or not at all on MacConkey Grow well on blood agar...

Non-fermenters Hannah Reilly MS, MLS, PA (ASCP)  Characteristics of Non- Fermenters Do NOT ferment glucose TSI reaction is K/K Many are oxidase positive Slower growing than Enterobacteriaceae Some grow poorly or not at all on MacConkey Grow well on blood agar Tend to be resistant to more antibiotics than Enterobacteriaceae Pseudomonas aeruginosa is the most commonly isolated non-fermenter  Alternate Energy Pathways Non-utilizers: Organisms do not use glucose as energy source Oxidizers: Oxidize rather than ferment glucose Strict aerobes Entner-Doudoroff pathway-oxidation pathway for glucose  Tests used for Non-fermenters Oxidase Indole OF Glucose Urea Motility Decarboxylases Pigment production Esculin hydrolysis Nitrate  Oxidase Detects enzyme cytochrome oxidase Reagent used: 0.5% tetramethyl-p-phenlenediamine HCL Oxidizes to a colored endproduct: Indophenol Test from Blood agar (never MAC) Positive: Blue/Purple color Negative: No change  OF (oxidative fermentative) Glucose Tests how organisms utilize glucose Hugh-Leifson Oxidative-Fermentative (OF) tube media used Designed to enhance the weak acid production of oxidative organisms Bromthymol ble pH indicator is added to cause a color change with acid production Need 2 tubes for each organism One is capped (left “open”) One is overlaid with mineral oil  Results of OF Test Oxidizer (aerobic): Open tube only is yellow Fermentation (anaerobic): Both tubes are yellow Non-utilizer of glucose: Both tubes stay green  Motility Non-fermenters will grow on top of motility media Must use wet mount exam  Pigment Production Many non-fermenters produce distinctive pigments  Esculin Hydrolysis o Bacteria has enzyme to break down esculin o Results in visible black color o This test is used for many bacteria, not just non-fermenters  Nitrate, Urease, Indole,& Decarboxylases Done just like for Enterobacteriaceae It may take the nonfermenters longer to become positive since they grow slower. Allow 48 hours for reactions to develop in manual and automated systems. Ehrlich’s is best indole test for nonfermenters Patients at Risk of Infection by Non- Fermenters Immunocompromised: Cancer patients, steroids, transplant patients Trauma: Gunshot, knife, puncture wounds, surgery, burns (Pseudomonas), aquatic wounds Implants: Catheters, joints, valves, corneal transplants, contact lenses Infusion fluids: Dialysate, saline irrigation Classification of Non-Fermenters Unlike the Enterobacteriaceae, this group does not have much in common other than an inability to ferment glucose Includes a wide variety of very different genera Are subdivided into families, and then into genera Are based on similarities in DNA/RNA  Genera we will discuss Pseudomonas Burkholderia Stenotrophomonas Alcaligenes Acinetobacter  Family Pseudomonadaceae Genus: Pseudomonas Sorted into groups by RNA similarities RNA group 1: Fluorescent group Pseudomonas aeruginosa Pseudomonas fluorescens Pseudomonas putida All members of this group produce a fluorescent pigment, pyoverdin Only P. aeruginosa produces the visible blue-green pigment, pyocyanin  Clinical significance of Pseudomonas aeruginosa #1 Most common non-fermenter isolated Found in soil and water Most commonly affects hospital patients Can live in hospital solutions such as soap, hand cream, flower vase water, whirlpool baths, sinks and oral thermometers  Clinical Significance con’t….. Infects areas that stay moist like: Burns Ear canals Spread by the contact of contaminated water or person-to- person contact People can carry the organism in their GI tract, respiratory tract, or skin Not usually found as normal flora in healthy people  Pseudomonas infections Grows in areas with water. Burns Swimmer’s ear Pulmonary infections, especially in patients with cystic fibrosis Nosocomial UTI Folliculitis from hot tubs, whirlpool baths Wound, eye, bone infections (osteomyelitis) Infant diarrhea Is resistant to many conventional antibiotics, which can make treatment difficult  Biochemical Characteristics Slender, long gram negative rod BAP agar may appear mucoid or flat, spready, ground glass look Oxidase + Glucose oxidizer in OF media Motile Reduces nitrate to nitrite Blue-green pyocyanin pigment Can grow at 42° Fruity “grape” odor  P. Fluorescens and P. putida Found in soil and water Rarely found in humans, may be found as oral flora Rare causes of opportunistic infections Do not grow at 42° C Do not produce blue green pyocyanin pigment May be mucoid on MAC  Burkholderia mallei & pseudomallei Both of these organisms are considered dangerous and should be handled carefully B. mallei causes glanders in horses and is a rare pathogen in humans B. pseudomallei causes meloidasis, a glanders-like condition in humans and animals Lives in soil Can be inhaled (pulmonary) Infect wounds Sepsis can follow Common in Australia and Asia  Burkholderia cepecia Used to be called Pseudomonas cepacia Found worldwide Lives in many hospital environments, equipment with moisture, a nosocomial opportunist. A plant pathogen (onion rot) Does not infect healthy humans Causes pulmonary infections, particularly in cystic fibrosis patients Very difficult to treat  Biochemical Reactions Weak oxidase producer and will often test negative OF oxidizer of glucose Lysine and ornithine positive Motile Slender, long gram neg rod Some strains have a yellow pigment No fluorescent pigment Smooth colonies Prefers 30° C, is an environmental organism normally  Cepacia Syndrome Cepacia Syndrome is the accelerated lung damage caused by Cepacia. Often Cepacia counts can be lessened with antibiotics (not totally cured). The syndrome occurs when the Cepacia returns to full strength and damages the lungs quickly. Cepacia Syndrome is a life threatening syndrome and can result in pneumonia and often sepsis and occurs in a rapid progression. Stenostrophomon as maltophilia Used to be called Xanthamonas maltophilia Maltophilia means “maltose lover” Utilizes maltose  Clinical Significance Frequently isolated from respiratory, wound and UTIs Free-living in the environment, including many hospitals sources Causes primary pneumonia and opportunistic infections in hospitalized patients Resistant to antibiotics which helps insure its survival in the hospital environment  Biochemical Characteristics Pigment: Lavender-bluish green to yellow on BAP Oxidase negative Motile Long slender gram negative rod OF oxidizer of maltose Non-utilizer of glucose Lysine positive Esculin positive Ammonia-like odor  Acinetobacter Genus: Acinetobacter Species: Acinetobacter baumanii (saccharolytic) Acintobacter lwoffi (non-saccharolytic)  Clinical Significance Widely distributed in nature, including hospitals Can colonize human skin Often introduced into normally sterile body sites by catheters and other hospital instrumentation Common isolate of respiratory, wound and UTIs Resistant to many antibiotics  Biochemical Characteristics Gram negative coccobacilli White color, turns dark pink to blue on MAC after several days incubation Oxidase negative Catalase positive Non-motile OF – glucose oxidizer or non-utilizer Strictly aerobic Penicillin resistant  Summary-ID of Non-fermenters Oxidase negative, non-motile Acinetobacter, gram negative coccobacilli Oxidase negative, motile Stenotrophomonas maltophilia, gram negative rod, lavender pigment, maltose utilizer Burkholderia cepacia (weak oxidase, may look negative), yellow pigment Oxidase positive, motile Pseudomonas aeruginosa, pyoverdin, pyocyanin, 42°C growth Most common: Pseudomonas aeruginosa, S. maltophilia, Acinetobacter sp.