Introduction of Sphingobacterium case report
Sphingobacterium is a non-fermermenter, Gram-negative rod, catalase test positive, oxidase test positive, and a genus of the family Sphingobacteriaceae. The genus Sphingobacterium is characterized by the high concentrations of sphingophospholipids as lipid components. Sphingobacterium mizutaii does not on MacConkey agar but grows well on blood agar with evidence of yellow pigment. Other species of Sphingobacterium grow well on MacConkey agar. The above picture is showing the growth of Sphingobacterium mizutaii with yellow pigment after 48 hours of incubation at 37°C. Pigment expression is well expressed at room temperature. Other medically important species of this genus are S. multivorum and S. spritivorum. It is ubiquitous in nature and rarely involved in human infection. Sphingobacterium mizutaii has been associated with blood, CSF, and wound infections; S. multivorum with blood and wound infections; and S. spritivorum with blood and urine infections.
Patient history
A 72 years old patient with a wound in the gluteal region having intolerable pain. Pus from this sent to the microbiology laboratory for culture and sensitivity and also Gram stain.
Samples were processed for investigation of the causative agents.
Gram stains findings
Pus cells: Plenty
Organisms: Few Gram-negative bacilli seen
Laboratory Diagnosis of Sphingobacterium
Pus for Culture and sensitivity
- Specimen inoculated on blood agar and MacConkey agar using an inoculating loop.
- These plates were incubated at 37° C for 24-48 hours.
- But growth observes only after 24 hours of incubation on blood agar but no growth on MacConkey agar.
- Blood agar was with yellow pigment.
- Further tests were performed as follows:
Gram stain finding-
Gram-negative bacilli seen
Hanging drop preparation-Negative .i.e Non-motile
Catalase test
Positive
Oxidase test
Positive
Biochemical reactions of Sphingobacterium
Triple sugar iron (TSI) agar test
Alkaline /no change
No hydrogen sulfide production
No gas formation
Motility Indole urease (MIU)test
Non-motile
Indole -Negative
Urea hydrolyzation test-Negative
Citrate Utilization test-Negative
Esculin test-Positive
Antibiotic sensitivity pattern
Getammycin : Resistant
Amikacin: Resistant
Colistin: Resistant
Trimethoprim-Sulfamethoxazole: Sensitive
Pefloxacin: Sensitive
Treatment
Patient treated with trimethoprim-sulfamethoxazole.
Final impression
Sphingobacterium mizutaii isolated from pus conformed phenotypically on the basis of the following characteristics:
- Gram-negative bacilli
- catalase positive
- Oxidase positive
- No growth on MacConkey agar
- Yellow pigmentation
- Non -fermenter
- Christensen urease test negative
- Non-motile
- Pefloxacin is sensitive whereas gentamycin and amikacin resistant
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Sphingobacterium case report -PDF file
Further Readings
- Bailey & Scott’s Diagnostic Microbiology. Editors: Bettey A. Forbes, Daniel F. Sahm & Alice S. Weissfeld, 12th ed 2007, Publisher Elsevier.
- Bailey & Scott’s Diagnostic Microbiology. Editors: Bettey A. Forbes, Daniel F. Sahm & Alice S. Weissfeld, 12th ed 2007, Publisher Elsevier.
- Clinical Microbiology Procedure Handbook Vol. I & II, Chief in editor H.D. Isenberg, Albert Einstein College of Medicine, New York, Publisher ASM (American Society for Microbiology), Washington DC.
- Colour Atlas and Textbook of Diagnostic Microbiology. Editors: Koneman E.W., Allen D.D., Dowell V.R. Jr, and Sommers H.M.
- Cowan & Steel’s Manual for identification of Medical Bacteria. Editors: G.I. Barron & R.K. Felthani, 3rd ed 1993, Publisher Cambridge University press.
- Jawetz, Melnick and Adelberg’s Medical Microbiology. Editors: Geo. F. Brook, Janet S. Butel & Stephen A. Morse, 21st ed 1998, Publisher Appleton & Lance, Co Stamford Connecticut.
- Mackie and Mc Cartney Practical Medical Microbiology. Editors: J.G. Colle, A.G. Fraser, B.P. Marmion, A. Simmous, 4th ed, Publisher Churchill Living Stone, New York, Melborne, Sans Franscisco 1996.
- Manual of Clinical Microbiology. Editors: P.R. Murray, E. J. Baron, M. A. Pfaller, F. C. Tenover and R. H. Yolken, 7th ed 2005, Publisher ASM, USA
- Textbook of Diagnostic Microbiology. Editors: Connie R. Mahon, Donald G. Lehman & George Manuselis, 3rd edition2007, Publisher Elsevier.