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Laboratory tests
The vitreous washings in a cassette were sent to the Microbiology laboratory for Gram stain and aerobic and anaerobic culture. The Gram stain of the vitreous fluid is shown in Figure 1.
The Gram stain results were as follows: rare to few thin faint staining gram negative rods noted. Cellular debris and fibrinous material was noted, but no distinct cells were present. The aerobic culture was no growth after 48 hours.
The cultures were held longer based on the positive Gram stain. After five days, small gray colonies with a diffuse margin appeared on blood and chocolate agar incubated in 5% CO2.
The Gram stain from the colonies showed bizarre pleomorphism, with fusiform gram negative rods, elongated forms, and coccoid forms as shown in Figure 2.
The isolate was positive for oxidase, catalase and esculin hydrolysis and was nitrate negative. The organism was not identifiable by routine methods used (API 20E strip, REMEL rapid non-fermenter panel) and was referred to the state laboratories for definitive identification by 16S ribosomal sequencing.
Antimicrobial therapy
The patient was placed on antimicrobial therapy for 14 days and appeared to recover fully.
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Laboratory Tests & Antimicrobial Therapy
Define Terms & Determine Source