Nonfermenters

1. Nonfermenters Victor S. Flauta, M.D. Division of Medical Microbiology The University of Toledo April 2011

2. Pseudomonas

3. Pseudomonas aeruginosa BAP MAC TSOY TSOY

4. Pseudomonas aeruginosa • Spot tests are acceptable to identify this organism, although AST is necessary. • Very mucoid strains have poor biochemical reactions. • Oxidase +, typical smell, & colony morphology (blue-green pigment) are 95% diagnostic. • Rare Aeromonas isolates can have similar colonies but no odor. • Pseudomonas is indole neg while Aeromonas is indole pos.

5. P. aeruginosa Photo: Victor S. Flauta, M.D.

6. Pseudomonas aeruginosa • Prevalent in the following patients: • Burn wounds • Cystic fibrosis • Acute leukemia • Transplant • IV drug users • Occur at moist areas: tracheostomies, catheters, burns, ear, weeping wounds • Causes UTI, RTI, eye infections, otitis externa, dermatitis, endocarditis

7. P. aeruginosa • Resistance to beta-lactams may arise during therapy. • Very rare to see gentamicin, tobramycin, & amikacin resistance concurrently.

8. P. aeruginosa • 1st Rx: antipseudomonal penicillin, imipinem, tobramycin, ciprofloxacin, ticarcillin-clavulanate, piperacillin-tazobactam, or aztreonam. • 2nd Rx: for serious infections: (antipseudomonal penicillins or broad-spectrum cephalosporins, or aztreonam, or ticarcillin-clavulanate or piperacillin-tazobactam or imipinem) + (meropenem or tobramycin or ciprofloxacin)

9. Pseudomonas fluorescens BAP MAC

10. P. fluoresecens, P. putida, & P. mendocina • None of these have blue-green pigment. • P. mendocina can be confused with nonpigmented P. aeruginosa. • P. fluorescens & P. putida are rare in clinical specimens • Both seen in bacteremia from transfused blood • P. putida – catheter-related sepsis • P. fluorescens - pseudobacteremia • Instrument will report as “fluorescens/putida group.”

11. P. oryzihabitans • Formerly Flavimonas, Ve-2 • The Flavimonas is replaced by Pseudomonas • Yellow pigmented but oxidase negative. • Wrinkled colony. • Similar to Chryseomonas luteola. • Associated with septicemia and prosthetic valve endocarditis. • Esculin negative.

12. P. oryzihabitans • MIC value or Etest value only. • Disk test unreliable.

13. P. stutzeri Photo: Victor S. Flauta, M.D.

14. P. stutzeri • Wrinkled colony (lactose negative) like B. pseudomallei (lactose positive). • Colonies are adherent on primary isolation but later become smooth. • Mainly comes from soil & water. • May have a slight yellow pigment.

15. P. stutzeri • Rare cause of infections (OM, pneumonia, endocarditis, meningitis, conjunctivits, osteomyelitis) • No CLSI interpretive criteria. • Refer or try Etest value. • Susceptible to most antibiotics.

16. Burkholderia cepacia BAP BAP MAC

17. Burkholderia cepacia • Formerly, Pseudomonas cepacia or CDC EO-1 • Can smell like P. aeruginosa • Lysine positive (rare in nonfermenters) • Oxidase positive (Stenotrophomonas maltophilia is LYS + but oxidase neg) • May be yellow on TSI. • Dangerous nosocomial respiratory pathogen especially in cystic fibrosis • Often resistant to quaternary ammonium disinfectants.

18. Burkholderia cepacia • New KB standards available for ceftazidime, meropenem, minocycline, & SXT • Natural resistance to ampicillin, amoxicillin, narrow-spectrum cephalosporin, colistin, & aminoglycosides • 1st Rx: SXT or meropenem or cipro • 2nd Rx: minocycline or chloramphenicol

19. Glanders in WWI Allied cavalries, such as this Belgian convoy, may have been the target of glanders attacks in World War I. http://www.pbs.org/wgbh/nova/bioterror/agen_glanders.html

20. Glanders in WWII Hangzhou, capital of east China's Zhejiang Province. http://english.peopledaily.com.cn/200506/16/eng20050616_190568.html

21. Glanders • Symptoms • nodular lesions in the lungs • ulceration of the mucous membranes in the upper respiratory tract • coughing, fever and the release of infectious nasal discharge • septicemia and death within days • Chronic form: nasal & subcutaneous nodules that eventually ulcerate. • Death can occur within months, while survivors act as carriers.

22. Burkholderia mallei • BIOTERRORISM AGENT • Formerly Pseudomonas mallei • Causes glanders in horses but not in the U.S. • Can be transmitted to humans • Ensure testing for ceftazidime, tetracycline, & imipinem

23. B. pseudomallei http://www.jcu.edu.au/school/bms/units/melioidosis.shtml

24. B. pseudomallei • BIOTERRORISM AGENT • Formerly Pseudomonas pseudomallei • Melioidosis in humans but not in the U.S. • Rough, convoluted colony in 3 days is diagnostic

25. Active Melioidosis • Fever • Pain or other symptoms • Pneumonia • Bone or joint pain • Cellulitis • Intra-abdominal infection • B. pseudomallei abscesses have a characteristic honeycomb architecture (hypoechoic, multi-septate, multiloculate)

26. Melioidosis : Vietnam War • Recognized in US servicemen involved in the Vietnam War, and was referred to as the "Vietnamese time-bomb.”

27. B. pseudomallei • Ensure testing for amoxicillin-clavulanic acid, ceftazidime, tetracycline, imipinem, & SXT • 1st Rx: ceftazidime (IV) • 2nd Rx: SXT, imipinem

28. P. mallei, P. pseudomallei • Rx for P. mallei: sulfadiazine, SXT • Rx for P. pseudomallei: ceftazidime or amoxi-clavulanate, SXT • Resistance to SXT appearing in Southeast Asia.

29. Sphingomonas paucimobilis • Formerly IIK-1, Ps. paucimobilis • Weakly motile • Bright yellow pigment. • Sometimes seen with respiratory equipment. • Isolated from various body sites & hospital environment • Bacteremia, peritonitis

30. Sphingomonas paucimobilis • Do not test for AST. If necessary try Etest. No CLSI criteria. Do MIC & report value only. • Most strains are susceptible to tetracycline, chloramphenicol, SXT, aminoglycosides

31. Stenotrophomonas maltophilia MAC BAP

32. Stenotrophomonas maltophilia • Probably the 2nd most common NF in the U.S. • Opportunistic infections • Emerging hospital-acquired pathogen • Ubiquitous • Now being reported in CF centers • Association between respiratory tract colonization & lung damage • Wide spectrum of disease

33. Stenotrophomonas maltophilia • Risk factors associated with death: • ICU patient • Older than 40 years • Pulmonary source of the isolate • About 85% are susceptible to SXT • Lysine positive (rare in NF) & oxidase neg

34. Stenotrophomonas maltophilia • Use new CLSI guidelines for disk testing of limited drugs • Naturally resistant to aminoglycosides and most beta-lactams except ticarcillin-clavulanate • Always resistant to carbapenem, imipinem, & ceftriaxone • 1st Rx: SXT • 2nd Rx: ticarcillin-clavulanate (+/- aztreonam)

35. Acinetobacter baumanii complex

36. Acinetobacter baumanii complex BAP MAC

37. Acinetobacter baumanii complex • Formerly A. calcoaceticus subsp anitratus or A. anitratus • Use the name currently on the database of the instrument • ~50% from UTI • Also ear, eye, nose, throat. • Normal on skin & feces • This organism is of nosocomial importance • Oxidase neg

38. A. baumanii in Iraq War http://www.cdc.gov/mmwr/preview/mmwrhtml/mm5345a1.htm

39. Acinetobacter baumanii • 5% resistant to imipinem • Often resistant to penicillin, ampicillin, chloramphenicol • Combination Rx with beta-lactam & aminoglycoside may be needed for serious cases • AST: interpret with Pseudomonas breakpoints • Always confirm if resistant to colistin.

40. Acinteobacter lwoffi • Oxidase negative • Sensitive to most other antimicrobials

41. Ralstonia spp. • R. pickettii (most common), R. paucula, R. gilardii • Rare in humans as etiologic agent • Probably a nonpathogen • Weak motility • Slow-growing, pinpoint colonies at 24 h on BAP • No CLSI interpretive criteria • Refer or try Etest value.

42. Pandoraea spp. • Biochemically similar to Burkholderia & Ralstonia • Differentiated by fatty acid profiles • Refer or report MIC value only.

43. Brevundimonas spp. • B. diminuta, B. vesicularis (formerly Ps. diminuta & Ps. vesicularis) • Unusual in clinical specimens • B. diminuta is associated with few bacteremias • B. vesicularis in hemodialysis, sickle cell, & immunocompromised • Requires pantothenate, biotin, cyanocobalamin vitamins for growth (B. diminuta also requires cystine)

44. Brevundimonas spp. • Do not use the disk diffusion test with these organisms • Use MIC method and interpret with Ps. aeruginosa standards.

45. Comamonas spp. • Formerly Pseudomonas spp • C. acidovorans, C. terrigena, C. testosteroni • Motile by flagellar tufts on polar stalks • Primarily a soil (environmental) organism • C. testosteroni is oxidase +, catalase + • GNR recovered from sputum, peritoneal fluid, urine, & stool • Uncertain pathogenicity • Orange indole reaction due to anthranilic acid from tryptone • MIC or Etest values only.

46. Delftia spp. • Phenotypically similar to Comamonas but oxidize fructose & mannitol • 25% have fluorescent pigment • 50% may be yellow or tan • Oxidase + • Grows on MAC • No CLSI criteria available for testing.

47. Acidovorax spp • Recently described genus • GNR; slightly curved • 3 species, all rare in humans • Questionably pathogenic • Aerobic & common environment (soil, water, plants) • No interpretive guidelines available • Do not do disk test • Use MIC only & use P. aeruginosa standards • Rx depends on susceptibility test

48. Thank You !