Ok so the first Microbe Meetup, possibly not a roaring success, but definitely not a failure. A few comments and some emails got close but no cigars, however this was a particularly hard identification and if you want to try and still guess then skip the rest of this post and go down to the microbe meetup.
Well lets look at what we have:
1.) The gram stain (although small) is a gram negative curved rod suggesting that it might be Vibrio spp.
2.) The colony morphology on maconkey suggests that the organism is a lactose fermenter. (Lactose fermenters on maconkey are pink, non-lactose fermenters are whitish-yellow) Most vibrio spp (cholera, alignolyticus) are NLF (non lactose ferementers) where as Vibrio vulnificus is a lactose fermenter and is commonly associated with MARINE trauma and puncture wounds, ding ding ding!
3.) Vibrio spp are also oxidase positive, H2S negative, and produce acid from TSI.
The main factors that we look at here are our gram stain, colony morphology on mac, subsequent confirmation of lactose fermentation, and patient history. We can ultimately deduce that Vibrio vulnificus is the organism of infection based on these strong identification parameters.
A little bit of background on V.vulnificus:
Vibrio vulnificus is a bacterium that causes a disease with over a 50 percent mortality rate, and it causes 95 percent of all seafood-related deaths.
Vibrio vulnificus (as we know) is a Gram-negative, motile curved bacterium found in warm water marine environments (in the Gulf of Mexico, the Atlantic Coast as far north as Cape Cod, and the U.S. West Coast). The bacterium thrives in warm seawater and is part of a group of vibrios that are "moderate halophiles", meaning they require salt for growth. It has been isolated from seawater, sediments, plankton and shellfish (oysters, clams and crabs). Vibrios are frequently isolated from oysters and other shellfish in warm coastal waters during the summer months. This correlates with the peak incidence of disease caused by the bacterium. In January of 2007 Vibrio vulnificus became a CDC nationally notifiable organism and has undergone an effort to reduce underreporting of culture results within the clinical setting.
Another aspect of Vibrio vulnificus is the rate of infections after a natural disaster such as a hurricane. Wound care is essential because contaminated sea water (as we saw with our case) can enter the wound and rapidly (12-24 hours) cause extreme infection. More information can be found here:
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