rusty nail ??pseudomonas or C.perfringens - USMLE Forums
USMLE Forums Logo
USMLE Forums         Your Reliable USMLE Online Community     Members     Posts
USMLE Articles
Go Back   USMLE Forums > USMLE Step 2 CK Forum

USMLE Step 2 CK Forum USMLE Step 2 CK Discussion Forum: Let's talk about anything related to USMLE Step 2 CK exam

Thread Tools Search this Thread Display Modes
Old 07-06-2011
kemoo's Avatar
USMLE Forums Guru
Steps History: 1+CK+CS
Posts: 378
Threads: 161
Thanked 103 Times in 52 Posts
Reputation: 117
Question rusty nail ??pseudomonas or C.perfringens

stepped on a big rusty nail i remember from step 1 that pseudomonas osteomyelitis very common

in kaplan surgery now similar story but they said gas gangrene (C.Perfringens )

so the clue rusty nail apply to both ??

how to differentiate between both ??
Reply With Quote Quick reply to this message

Old 07-06-2011
USMLE Forums Addict
Steps History: ---
Posts: 146
Threads: 27
Thanked 74 Times in 42 Posts
Reputation: 84
Post both

  • Pseudomonas
  • aerobes, occurs on skin surface
  • opportunistic pathogen
  • may cause serious & lethal infection
  • colonize ventilators, iv catheters, urinary catheters
  • Wound infection, burn, septicemia
  • Treatment: aminoglycosides, piperacillin, ceftazidime
<LI sizset="0" sizcache="6478">
  2. Cl. Perfringens, Cl. Septicum
  • Exotoxins: lecithinase, collagenase, hyaluridase
  • Large wounds of muscle ( contaminated by soil, foreign body )
  • Rapid myonecrosis, crepitus in subcutaneous tissue
  • Seropurulent discharge, foul smell, swollen
  • Toxemia, tachycardia, ill looking
  • X-ray: gas in muscle and under skin
  • treatment:Penicillin, clindamycin, metronidazole
  • Wound exposure, debridement , drainage, amputation
  • Hyperbaric oxygen
Reply With Quote Quick reply to this message
Old 04-26-2012
USMLE Forums Newbie
Steps History: 1 + CK
Posts: 3
Threads: 0
Thanked 5 Times in 2 Posts
Reputation: 15

The clue is the presentation: soft tissue infection or osteomyelitis?

Pseudomonas is notorious for osteomyelitis following nail puncture in adults, while clostridium hardly if ever causes osteomyelitis.

C perfringes (an anaerobe) on the other hand, causes subcut infection and release O2 in the process, thus the gas gangrene (subcut crepitus).
Reply With Quote Quick reply to this message
The above post was thanked by:
doc_study (04-27-2012), tyagee (04-26-2012), usmledee (04-27-2012)
Old 04-27-2012
USMLE Forums Master
Steps History: 1+CK+CS
Posts: 1,867
Threads: 149
Thanked 2,106 Times in 1,049 Posts
Reputation: 2126

Another point is that you get Pseudomonas infection if the nail goes through sneakers since sneakers contains the Pseudomonas reservoir. So, the organism is not in the nail (nail can be clean & not rusty) but you get inoculated by Pseudomonas from the shoe sole.
In contrast, the clostridium is in the nail (rusty,dirty, dusty) and you can be barefoot to get inoculated.
Reply With Quote Quick reply to this message
The above post was thanked by:
doc_study (04-27-2012), usmledee (04-27-2012)



Quick Reply

Register Now

In order to be able to post messages on the USMLE Forums forums, you must first register.
Please enter your desired user name, your email address and other required details in the form below.
User Name:
Please enter a password for your user account. Note that passwords are case-sensitive.
Confirm Password:
Email Address
Please enter a valid email address for yourself.
Email Address:
Medical School
Choose "---" if you don't want to tell. AMG for US & Canadian medical schools. IMG for all other medical schools.
USMLE Steps History
What steps finished! Example: 1+CK+CS+3 = Passed Step 1, Step 2 CK, Step 2 CS, and Step 3.

Choose "---" if you don't want to tell.

Favorite USMLE Books
What USMLE books you really think are useful. Leave blank if you don't want to tell.
Where you live. Leave blank if you don't want to tell.


Human Verification

In order to verify that you are a human and not a spam bot, please enter the answer into the following box below based on the instructions contained in the graphic.

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Similar Threads
Thread Thread Starter Forum Replies Last Post
Exotoxin A of Pseudomonas and Pyogenes step1saga USMLE Step 1 Forum 1 12-04-2010 08:40 PM
Pseudomonas Aeruginosa Exotoxin and ADP ribosylation evavar USMLE Step 1 Forum 2 12-04-2010 08:01 AM

RSS Feed
Find Us on Facebook
vBulletin Security provided by vBSecurity v2.2.2 (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.

USMLE® & other trade marks belong to their respective owners, read full disclaimer
USMLE Forums created under Creative Commons 3.0 License. (2009-2014)