Bite Wound II

I am sure everyone has been eagerly awaiting the answer to last week’s post. First I am going to explain the organisms NOT responsible.

Staphyloccocus aureus – Gram positive cocci in clusters

S. aureus is infamous for its ability to infect skin and soft tissue. The infection would resemble the same characteristics except timing. S. aureus would typically take more time to develop this infection, close to 3 to 5 days after the incident instead of overnight.

Eikenella corrodens – Fastidious gram negative rods

E. corrodens is an organism frequently involved with human bite infections, and at times present in dog or cat bite infections. These animal bite infections are often on the head and neck area, which would match the profile of our patient. Again, this organism would require a longer incubation time (days to weeks) to develop the severe state of this infection.

Pasteurella multocida – Gram negative coccobacilli

To be honest, I immediately guessed this organism before finishing the article. It is often involved with infected cat bites, as well as some dog bites. The features of a P. multocida infection would show similar results to this infection with the rapid onset and progression, but it did not grow in the culture of this infection.

Our culprit is Streptococcus pyogenes (Group A Streptococcus), a Gram positive cocci in chains.

The speed of this infection well represents the rapid progression of S. pyogenes infections. Lab results, though not listed in the article, would show a beta hemolysis, positive PYR, and susceptible Bacitracin test. The patient’s clinicians changed his treatment ultimately to 80mg/kg/day of amoxicillin, and the patient thankfully recovered.

Next week I hope to post about a fungus infection! Thank you for reading!!
 

Article:

Bite Wound Article - Healio

Bite Wound I

Since it seems like “bite wounds” are memorable for certain bacteria, I have found an article posted this month that works through a case study of such an infection. This will be a two part post, and I will provide the answer and link in the second post.

The case begins with a 9.5 year old boy who received a bite wound to the face from his neighbor’s dog. The dog’s background, including vaccinations, appeared clear, and it was determined that the instance was “provoked” from the child. The boy was taken to a nearby hospital where they sutured his wound and wrote a prescription for antibiotics (amoxicillin/clavulanate) – clavulanate is asked about in the BOC.

The prescription was not filled, and the boy returned to the hospital within 24 hours with a fever of 103°F and painful inflammation. Previous sutures were removed; along with IV clindamycin (broad spectrum antibiotic) administered. The child began to take the previous prescription as instructed.

Shortly after, the child returned to the emergency department for symptoms worsening, and began treatment with ceftriazone IM with admission into the hospital. His physical exam revealed clear vital signs, but yellowish discharge from the wounds.

From the information provided, what would you guess the pathogen is?

Staphylococcus aureus

Eikenelle corrodens

Group A Streptococcus

Pasteurella multocida

Feel free to comment with your guess!

Introduction Post

This blog, Infectious Insight, serves to shed light on infectious disease topics that I find interesting including current events, publications, and subject matter we are currently covering in class. I am a graduate student who absolutely loves laboratory science, especially microbiology, since most of my academic and vocational experience is in that field. I plan to write a post at least once a week. I hope this blog provides additional insight that you find intriguing. Please feel free to leave any comments with questions you may have about the posted topics or list any other topics you would like for me to write about.