GNR: Non Enterbacterales Flashcards
Pseudomonas spp. characteristics
aerobic, non-spore forming GNR, oxidize glucose, reduce nitrate, oxidase positive, catalase positive, motile
Pseudomonas aeruginosa diseases
causes nosocomial infections, bacteremia, wound infections, UTIs, keratitis (cornea inflammation), otitis externa (swimmer’s ear), folliculitis (hot tubs) and pneumonia (esp. in people with CF)
Which 6 species of Pseudomonas contain pyoverdin?
P. aeruginosa, P. fluorescens, P. monteilii, P. mosseilii, P. putida, and P. veronii
Out of the 6 species of Pseudomonas that contain pyoverdin, which ones can grow at 42C?
Only P. aeruginosa can grow at 42C out of the fluorescent group
Which Pseudomonas species are oxidase negative?
P. luteola and P. oryzihabitans
Which species of Pseudomonas do not utilize glucose?
P. alcaligenes, and P. pseudoalcaligenes
Key characteristics of P. aeruginosa
usually B hemolytic, grapelike or corn tortilla odor, metallic sheen with green/blue pigment, produces N2 gas from reduction of nitrate, and arginine positive
Which species of Pseudomonas can grow at 42C?
P. aeruginosa, P. luteola, P. mendocina, and P. pseudoalcaligenes
Which species of Pseudomonas can reduce nitrate all the way to nitrogen gas?
P. aeruginosa, P. mendocina, P. stutzeri, and P. veronii
Stenotrophomonas maltophilia characteristics
straight, small GNR, pigmented lavender/green colonies, ammonia-like odor, oxidizes maltose more quickly than glucose, oxidase negative, motile, lysine positive, DNase positive, resistant to many antimicrobial agents
Stenotrophomonas maltophilia diseases
most infections are nosociomal because it can survive on inanimate objects for weeks to months (colonize medical equipment); bacteremia, wound infections, pneumonia, and UTIs
Brevundimonas biochemicals
Positive: oxidase,
Negative: nitrate, lysine, lactose, sucrose
Different btw species: B. diminuta is maltose negative and white on BAP while B. vesicularis is positive and orange on BAP
Acidovorax biochemicals
Positive: oxidase, nitrate and glucose
Negative: lysine, lactose, sucrose, and maltose
Ralstonia biochemicals
make take up to 72 hours to grow
Positive: oxidase and xylose
Negative: lysine and sucrose
Ralostonia picketti vs. R. insidiosa vs. R. mannitolilytica
R. picketti: nitrate positive, mannitol negative, and glucose positive
R. insidiosa: nitrate positive and glucose negative
R. mannitolilytica: nitrate negative, mannitol positive, and glucose positive
Pandoreae biochemicals
causes infections in CF patients and those with chronic obstructive pulmonary disease
Negative: lusine, lactose, sucrose, maltose, and xylose
Variable for oxidase and nitrate
Comamonas biochemicals
aerobic, non-spore forming GNR with polar flagella
Positive: oxidase and nitrate
Negative: lysine, glucose, sucrose, lactose
Delftia biochemicals
Positive: oxidase, nitrate, grows at 42C, mannitol
Negative: lysine, glucose, lactose, sucrose
Cupriavidus biochemicals
Positive: oxidase
Negative: nitrate, lysine, glucose, lactose, sucrose
Which species of Burkholderia are considered select agents?
Burkholderia mallei and Burkholderia pseudomallei
Burkholderia cepacia characteristics
survives well in hospital environment and can colonize CF patients; earthy odor, colonies on MAC can turn red due to lactose oxidation
Which agars can be used to isolate Burkholderia cepacia and pseudomallei
Pseudomonas cepacia (PC) agar and oxidative-fermentative base-polymycin B-bacitracin-lactose (OFPBL) agar; will be yellow from lactose utilization
Burkholderia cepacia biochemicals
Positive: oxidase, lysine, glucose, lactose, sucrose, maltose, and mannitol
Negative: nitrate
Burkholderia mallei biochemicals
Positive: nitrate and glucose
Negative: lysine, does not grow at 42C, sucrose, maltose, and mannitol
Burkholderia pseudomallei biochemicals
Positive: oxidase, nitrate, lysine, glucose, lactose, maltose, and mannitol
Diseases caused by Burkholderia pseudomallei and mallei
Melioidosis/ Whitmore’s disease
What are the different types of melioidosis?
Pulmonary, bloodstream, disseminated, and localized
Symptoms of Pulmonary melioidosis
Cough, Chest pain, High fever, Headache, and Anorexia; it can be mistaken for pneumonia or TB
Symptoms of localized melioidosis
Localized pain or swelling, Fever, Ulceration, and Abscess
Symptoms of bloodstream melioidosis
Fever, Headache, Respiratory distress, Abdominal discomfort, Joint pain, and Disorientation
Symptoms of disseminated melioidosis
Fever, Weight loss, Stomach or chest pain, Muscle or joint pain, Headache, Central nervous system/brain infection, and Seizures
What are the risk factors for melioidosis?
Diabetes, Liver disease, Renal disease, Thalassemia, Cancer, or another condition (not related to HIV) that weakens the immune system, and Chronic Lung disease (such as cystic fibrosis, chronic obstructive pulmonary disease (COPD), and bronchiectasis)
Where is B. mallei and pseudomallei found?
It is more common in SE Asia and the tropics, but it can also be found in the soil in the Gulf Coast region of Mississippi; those in Mississippi during flooding/hurricanes are at a higher risk
Burkholderia gladioli biochemicals
Positive: glucose, xylose and mannitol
Negative: lysine, lactose, sucrose, and maltose
What is the treatment for melioidosis?
IV: Ceftazidime administered every 6–8 hours or Meropenem administered every 8 hours
Oral: rimethoprim-sulfamethoxazole taken every 12 hours or Amoxicillin/clavulanic acid (co-amoxiclav) taken every 8 hours
Acinetobacter spp. characteristics and diseases
cause opportunistic infections, different species are oxidizers or asaccharolytic, the second most common nonfermenter; surgery, extended ICU stays, antimicrobial therapy, and use of respiratory equipment are risk factors for infection
Acinetobacter spp. biochemicals
oxidase negative, catalase positive, nonmotile, nitrate negative, nonpigmented, grow on MAC, indole negative, strictly aerobic
Which Acinetobacter spp. are major pathogens and what are they associated with?
Species in the A. baumanni complex are major pathogens including: A. baumanni, A. pitti, A. nosocomialis, and A. lwoffi; associated with returning soliders from the Iraq war
Moraxella spp. characteristics and diseases
rarely cause disease (opportunistic), can pit BAP agar, not all species will grow on MAC, asaccharolytic, small GNCB (M. cattarhalis is a GNC)
Moraxella spp. biochemicals
oxidase positive, nonpigmented, indole negative, nonmotile, variable nitrate, susceptible to penicillin, trypsin negative
Oligella biochemicals
hydrolyzes urea, oxidase positive, indole negative, trypsin negative, nitrate positive, nonpigmented, phenylalanine positive
Psychrobacter spp. biochemicals
urease positive, phenylalanine positive, oxidase positive, indole negative, nonpigmented, grows on MAC, trypsin negative
Myroides spp. biochemicals
spreads like Bacillus spp., fruity odor, grows on MAC, oxidase positive, indole negative, trypsin positive, urea positive, nitrate negative, nitrite positive, yellow pigmentation, nonmotile
Rhizobium radiobacter biochemicals
motile, grows optimally at 25C, urea positive, phenylalanine positive, esculin positive, oxidase positive, indole negative, trypsin positive, grows on MAC
Sphingomonas paucimobilis/ paraaucimobilis biochemicals
oxidase positive, nitrate negative, motile at 18-22C but not 37C, does not grow on MAC, indole negative, trypsin positive, ONPG positive, esculin positive, trypsin positive
Sphinobacterium multivorum/ spiritivorum biochemicals
nonmotile, urea positive, oxidase postive, nitrate negative, indole negative, trypsin positive
Shewanella putrefaciens/ algae biochemicals
oxidase positive, nitrate positive, motile, grows on MAC, indole negative, trypsin positive, ornithine positive, H2S positive
S. algae need NaCl to grow
Chryseobacterium spp. biochemicals
nonmotile, thin GNR, oxidase positive, indole positive
Eliabethkingia meningoseptica biochemicals
oxidase positive, indole positive, ONPG positive, esculin positive, nitrate positive, nonmotile, grows on MAC
Note: associated with neonatal meningitis, endocarditis, and nosocomial infections from dialysis
Methylobacterium spp biochemicals
can utilize methanol as the sole carbon source; associated with septicemia and peritoneal dialysis peritonitis; dry colonies that do not grow on MAC, oxidase negative, pink pigmentation, nitrate negative, motile, indole negative
Roseomonas spp. biochemicals
optimal growth on SAB but will grow on MAC, mucoid/runny colonies, weakly oxidase positive or negative, nitrate negative, pink pigment, motile, indole negative
Actinobacillus spp. biochemicals and diseases
associated with animal bites/ contact with animals; does not grow on MAC, oxidase positive, nitrate positive, indole negative, glucose positive, sucrose positive
Which organisms are in the HACEK group and what defines this group?
Aggregatibacter aphrophilus, Aggregatibacter actinomycetemcomitans, Cardiobacterium hominis, Eikenella corrodens, and Kingella kingae; all of these cause endocarditis
What is endocarditis?
Endocarditis is inflammation of the inside lining of the heart chambers and heart valves, leading to fatigue, malaise, weight loss, and fever. Echocardiography shows bacterial vegetation.
What happens in endocarditis is untreated for an extended period of time?
Osler’s nodes, Roth’s spots, Janeway lesions, and splinter hemorrhages
Aggregatibacter spp. diseases
A. actinomycetemcomitans is the most common cause of periodontal disease and colonies develop a star-like/ cigar structure and pitting of the agar
A. aphrophilus can cause systemic disease as well as bone and joint infections
Aggregatibacter spp. biochemicals
Indole negative, nitrate positive, does not grow on MAC, urea negative, esculin negative, glucose positive, fermenters
How are A. actinomycetemcomitans and A. aphrophilus distinguished from each other?
A. actinomycetemcomitans is ONPG positive, catalase positive, and sucrose negative while A. aphrophilus is ONPG negative, catalase negative, and sucrose positive;
Cardiobacterium hominis biochemicals
Gram stain GNRs that form rosettes, can pit the agar, does not grow on MAC, fermenter, oxidase positive, catalase negative, indole positive, nonmotile, nitrate negative, urea negative, glucose positive, sucrose positive, esculin negative
Eikenella corrodens diseases
human bite wound infections, abscesses, osteomyelitis, and usually infections are mixed with other organisms
Eikenella corrodens biochemicals
capnophilic, require hemin for isolation, do not grow on MAC, small flat yellow colonies, corrode the agar and have a bleachlike odor, oxidase positive, asaccharolytic, nonmotile, indole negative, catalase negative, nitrate positive, urea negative, esculin negative, glucose and sucrose negative, ornithine positive
Kingella kingae diseases
associated with osteomyelitis, septic arthritis, and septicemia in infants/young children
Kingella kingae biochemicals
capnophilic, pit agar, oxidase positive, grows on gonococcal selective medium so it can be confused for Neisseria (but dif. biochemicals specifically catalase), oxidase positive, catalase negative, indole negative, does not grow on MAC, urea negative, esculin negative, glucose positive, sucrose negative
How are Kingella species differentiated from each other?
K. kingae- produces acid from maltose while other spp. do not
K. denitrificans- reduces nitrate unlike other spp.
K. oralis- found in dental plaque
What are the key biochemicals for differentiating between the different HACEK group members?
Cardiobacterium is the only one positive for indole
Aggregatibacter and Eikenella are nitrate positive while others are negative
Only Eikenella is glucose negative
Capnocytophaga spp. diseases and biochemicals
periodontitis, bacteremia, and wound infections (associated with dog bites b.c of animal strains)
gliding motility, indole negative, capnophilic, does not grow on MAC, nitrate negative, urea negative, glucose and sucrose positive
How are human strains of Capnocytophaga and animal strains differentiated from each other?
Animal strains are catalase positive, arginine positive, and oxidase positive
Human strains are catalase negative and oxidase negative
Dysgonomonas spp. biochemicals
nonmotile, strawberry odor, catalase negative, nitrate negative, oxidase negative, ONPG positive, does not grow on MAC, urea negative, glucose and sucrose positive
Suttonella indologenes biochemicals
oxidase positive, indole positive, nitrate negative, urea negative, esculin negative, glucose and sucrose positive
Chromobacterium violaceum diseases and biochemicals
rare cause of wound infections and bacteremia from contamination with soil or water; grows on MAC, violet pigment from producing violacein, urea positive, indole positive, oxidase positive, catalase positive, nitrate positive, esculin negative, glucose positive arginine positive, motile
Streptobacillus moniliformis diseases and biochemicals
causes rat bite fever, Haverhill fever/epidemic arthritic erythema (from ingesting milk, water or food contaminated), can have a necklace appearance on GS, fried egg colonies, indole negative, oxidase positive, catalase negative, nitrate negative, does not grow on MAC, urea negative, glucose positive, sucrose negative
What are the special growth requirements for Streptobacillus moniliformis?
It is inhibited by sodium polyanethol sulfonate, and needs 10-20% serum to grow
Legionella characteristics
aquatic bacteria that can be found in bodies of water and human made water systems, including AC, hot tubs, cooling towers, humidifiers, and showers; can be resistant to chlorine; causes disease through inhalation of aerosols and the severeness is based on the amount of exposure; intracellular parasite of free living ameba, ciliated protozoa, and slime mold; motile, obligate aerobic, asaccharolytic (use amino acids)
Legionella diseases
It infects alveolar macrophages after inhalation and replicates within the macrophage until it releases itself into the lungs
Pneumonia/ Legionnaires’ disease: acute pneumonia indistinguishable from other bacterial pneumonias (2-14 days after exposure)
Pontiac Fever: acute, self-limiting flu-like illness (24-48 hours after exposure)
Extrapulmonary infections (rare): abscesses in brain, spleen, lymph nodes, muscles, surgical wounds, and other sites
Legionella isolation/ identification
Lung biopsies have the highest yield, but sputum/BAL have increased detection; optimal growth at 35C and enhanced by iron and humidity
*Medias: BCYE w/ or w/o antibiotics should be used after pretreating the specimen to remove other bacteria
- A culture w/ and w/o L-cysteine should be done and then growth should be compared because it can only grow w/ L-cysteine
- Immunofluorescent microscopy is more sensitive than other stains
*Molecular methods:
- Direct IFA (DFA)
- Urine antigen test
- PCR
What are the pros and cons of different Legionella tests
The urine antigen test only detects serogroup 1. DFA tests have varying sensitivity and depends on how much organism is present; can also have false positives from Pseudomonoas, Francisella, and Bordetella
Bordetella spp. diseases
B. pertussis causes whooping cough
B. parapertussis can mimic whooping cough, but it is milder
B. bronchispetica can cause pneumonia, bacteremia, and wound infections generally in immunocompromised individuals
Cultures for Bordetella spp.
Pertussis is fastidious and is inhibited by fatty acids and peroxides so it needs neutralizing substances like charcoal to grow. Bordet-Gengou blood agar, Charcoal-horse blood agar/ Regan-Lowe charcoal agar, and Jones-Kendrick charcoal agar are used. Should not be put in a CO2 incubator, grows at 35C in humid air. Colonies look like mercury drops on special agars.
Bordetella spp. Identification
DFA tests can be used for rapid detection. All spp. grow on BAP and MAC other than B. pertussis. All three spp. are catalase positive.
B. pertussis is nonmotile, nitrate negative, oxidase positive, and urease negative; B. parapertussis is nonmotile, nitrate negative, oxidase negative, urease positive at 24hr; B. bronchiseptica is motile, nitrate positive, oxidase positive, and urease positive at 4hr
Achromobacter spp. biochemicals
Involved in nosocomial infections from contaminated solutions
catalase positive, motile, aerobic, oxidase positive, grows on MAC, urea negative, and nitrate positive other than A. faecalis
Alcalifenes faecalis biochemicals
motile, aerobic, catalase positive, oxidase positive, fruity odor, green hue, and reduces nitrite but not nitrate
Brucella spp. animal sources and specific diseases
B. melitensis: goats and sheep, causes Malta fever, and is the most virulent and prevelant
B. abortus: cattle, causes Bang’s disease
B. canis: canines
B. suis: swine
All can cause brucellosis from ingestion of, skin contact w/, or inhalation of infected material
Brucella spp. biochemicals
nonmotile, intracellular (monocytes and macrophages), 35C, catalase +, oxidase +, urease +, nitrate +, CO2 enhances growth
B. melitensis and B. canis do not produce H2S while the other species do, B. suis and B. canis are both susceptible to basic fuchsin, resistant to thionine, and produce urea in less than 90 minutes. B. melitensis is resistant to both dyes and takes over 90 minutes to produce urea. B. abortus is resistant to basic fuchsin, susceptible to thionine, and take greater than 90 minutes to produce urea
Brucella spp. testing other than culture
PCR, Microagglutination tests, ELISA, IgM serology
Pasteurella multocida diseases
respiratory infections, septicemia, wound infections, associated with animal bites, resulting in localized cellulitis and lymphadenitis
Pasteurella spp. biochemicals
All spp. are nonmotile, nitrate positive, catalase positive, sucrose positive, do not grow on MAC, and all are mannitol negative other than P. multocida and indole positive other than P. aerogenes
P. aerogenes: urea positive and maltose positive
P. canis: urea negative, ODC positive, and maltose negative
P. dagmatis: urea positive, ODC negative, and maltose positive
P. multocida: urea negative, ODC positive, and maltose negative
P. stomatis: urea negative, ODC negative, and maltose negative
Bartonella spp. diseases and biochemicals
Aerobic, oxidase negative, urease negative, motile, and does not produce acid from carbohydrates.
B. bacilliformis: localized to the Andes (sand fly vector), leads to anemia from penetrating RBC
B. quintana: transmitted by a sucking louse and causes trench fever/ 5-day fever
B. henselae: caused by fleas on cats and can lead to cat scratch disease
Afipia spp. biochemicals
Urease positive, oxidase positive, and produces acid from D-xylose
Francisella tularensis diseases
Tularemia (treated with gentamicin)
causes ulceroglandular, galndular, oculoglandular, systemic tularemia, and pneumonic types of tularemia.
Carried by rodents, rabbits, beavers, and insect vectors (ticks and deerflies)
Francisella tularensis biochemicals
weakly catalase +, nonmotile, strict aerobe, oxidase negative, needs cysteine to grow, urea negative, B-lactamase +; can be mistaken for Haemophilus.
Should grow on MTM, BCYE, or cystine heart agar w/ 9% chocolized sheep blood (CHAB)
Testing other than culture for Francisella tularensis
DFA, IHC staining for tissues, PCR, Microagglutination test, ELIDA, and tube agglutination test
