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Nonfermentative Gram Negative Bacilli

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Fermentation
Located on Embden-Meyerhof-Parnas Pathway; Anaerobic metabolism; Oxidation/reduction rxn; Organic compound; Large amounts of mixed acid products and gas may be produced - Detected through pH changes
Oxidation/Oxidative
Located on Entner-Dudoroff Pathway; Aerobic metabolism - strictly aerogic org (oxygen required for glycolysis to work); Weak acids produced but no gas produced; Require more sensitive detection systems
1.Nonfermenters 2.Predominantly opportunistic 3.Nonspore formers 4.Obligate aerobic 5.No change on TSI (nonfermenters so they don't produce acids) 6.Found in the environment 7.Nonsaccharolytic (non-oxiders) 8.Resistant to most antibiotics
8 characteristics of nonfermentative gram - bacilli
1.BAP 2.MAC 3.Hugh-Leifson OF
Media used for nonfermentative gram - bacilli
Hugh-Leifson OF
Type of media used for nonfermentative gram - bacilli; Semi-solid media (enhances acid detection); Decrease in peptone concentration (minimizes formation of oxidative products which raise pH and neutralize weak acids); Increase in carbohydrate concentration (enhnaces acid production); Indicator= Bromothymol blue; Diphosphate buffer (stabilizes pH for enhanced acid production); Innoculate 2 tubes w/ org and leave one tube exposed to the air (aerobic) and one tube is overlayed w/ mineral oil (anaerobic)
Oxidative - strict aerobe
Acid in open tube of Hugh-Leifson OF
Fermentation - Facultative anaerobe
Acid in both closed and open tube of Hugh-Leifson OF
Nonsaccharyltic org (org doesn't use carbohydrates fermentatively or oxidatively
NO acid in either open or closed tube of Hugh-Leifson OF
1.Slow growing organisms (may take several days for rxns to occur) 2.Spp. producing amides from AA may cause weak acid rxns to revert w/ time (use all the carbohydrates so the rxns begin to revert)
Precautions/limitations of nonfermentative gram - bacilli
1.Oxidase positive for gnb on BAP*** 2.Growth or no growth on MAC 3.Evidence of glucose non-fermentation on TSI (K/K) 4.Motilitiy and flagella location 5.Pigment producing colonies 6.Fluorescence colonies 7.Distinct odors 8.Grow on BAP
Recognition clues of nonfermentative gram - bacilli
ID for Pseudomonoas aeurginosa
Org identified as being oxidase +; TSI= K/K; Good growth at 42C; Production of blue-green, yellow, red, or brown colonies on Mueller Hinton media or TSA***; Grows well on BAP and MAC; Distinct grape odor
Diseases of Pseudomonas aeuroginosa
1.Infections of burn sites**** 2.Wounds 3.Lower respiratory tract infections - Commonly causes pneumonia in cystic fibrosis patients 4.Septicemia 5.Septic arthritis 6.Destructive eye infections (contacts) 7.Swimmers ear Special antibiotics as this org is resistant to most
Pseudomonoas pigments
1.Pyocyanin - blue/green colonies (most common) 2.Pyoverdin - yellow colonies (fluorescent) 3.Pyorubin - rust colonies 4.Pyomelanin - brown colonies
Fluorescent Pseudomonoas
1.fluorescens 2.putida 3.monteilli
Burkholderia cepacea
Org commonly seen w/ rotting onions; Causes jungle rot (foot rot) in humans; Isolated from water sources, IV fluids, detergent solutions; Grows in providone-iodine and chlorhexidine; Known to give false positive blood cultures (May sterilize the area you're drawing from w/ iodine that has this org in it which will then contaminate your sample); Oxidase +; TSI= K/K; Grows well on MAC
Diseases of Burkholderia cepacea
1.Pneumonia 2.Heart valve infections 3.UTI 4.Jungle rot
Burkholderia (Psuedomonas) mallei
Org that causes Glanders
Glanders
Animal disease (horses, goats, domestic animals) that can be passed onto humans via infected animals; Endemic in Africa, SA, Asia; Eradicated in NA and Europe; Causes purulent inflammation of mucous membranes and ulcerative skin lesions; If left untreated it may affect a person's bones, liver, CNS and result in death
Burkholderia (Pseudomonas) pseudomallei
Org that causes Melioidosis
Melioidosis
Zoonotic disease; Common in China and SE Asia; Acute = Fulminant pneumonia, emphysema, lung abscess, septicemia, liver and spleen complications; Chronic= Osteomyelitis, multiple internal organ abscesses, time bomb of Vietnam war
Acinetobacter, Chryseomonas, Flavimonas, Stenotrophomonas
Opportunistic pathogens; Unknown definitive virulence factors; Growth on MAC but oxidase NEG***; Wide distribution in nature and hospitals; Isolated as colonizers instead of infectious; Seen in debilitated patients, ICU, burn victims, immunosuppressed, on instrumentation, and multiple ATB's; May be pathogenic depening on where they are isolated
Achromobacter
Org that are environmental inhabitants; Rarely isolated from humans; Seen w/ contaminated medical devices; Immunocompromised; Oxidase +; Grows well on MAC
Chryseobacterium (Flavobacterium)
Org that is commonly found in the environment; Has the ability to survive in hospital environments (esp moist areas); Can survive in chlorinated water
Chryseobacterium meningosepticum
Org that is commonly associated w/ neonatal meningitis***; Nosocomial acquired; May also affect comprimised adults; Yellow pigmented; Glucose oxidizer; Growth on MAC; Oxidase +
Diseases causing meningitis in newborns
1.Streptococcus agalactiae 2.E.coli 3.Listeria monocytogenes 4.Chryseobacterium meningosepticum
Alcaligenes and Bordetalla (non-pertussis)
Very diverse group of org; All are MAC + and Oxidase +; Nonglucose utilizers; Most grow well (1 exception); Commerical ID methods limited
Vibrio and Aeromonas
Org that are MAC + and Oxidase +; Glucose fermenters; Primarily found in the water; Always pathogenic; Transmitted via ingestion of contaminated water, seafood, or skin exposure to infected water
Vibrio cholerae
Causative agent of human cholera; Many different serotypes/biotypes; Produces a cholera toxin; May have to treat both the org and the toxin; Causes hypersecretion of water and electrolytes in GI tract resulting in extremely watery diarrhea (rice water stools, fluids and mucous flecks); Dramatic fluid loss->severe dehydration->hypotension->death; Toxin mediated disease; Blood and inflammatory cells absent***; Other toxins and factors are produced but their role is unknown; Specmin source=Feces (rectal swab); Antibiotics decrease severity and shorten length of disease; Rehydration of patient important
Carey-Blair Transport media
Media used for Vibrio cholerae
ID of Vibrio cholerae
Toxin of this org can be identified through ELISA or a latex agglutination test; Microscopic- Darkfield, rapid, darting or shooting star motility; GNB w/ straight/slightly curved rods; Sucrose + on TCBS
Vibrio
Org grows well on BAP, Chocolate, MAC; NLF except for spp. vulnificus is LF
Thiosulfate Citrate Bile Salts Sucrose Agar
Selective media for Vibrio
Vibrio cholereae
Sucrose + on TCBS agar
Vibrio parahemolyticus
Sucrose - on TCBS agar
Vibrio vulnificus
Sucrse +/- on TCBS agar