Extra credit case study In August 2014, a 68-year-old man su…
Extra credit case study In August 2014, a 68-year-old man sustained a deep bite to his left fourth and fifth fingers from his pet African gray parrot. The gentleman had a past medical history of chronic obstructive pulmonary disease, for which he took regular inhaled steroids. He was also severely affected by osteoarthritis, for which he took long-acting morphine as analgesia. A day following the parrot bite, he saw his family practitioner for a consultation. The practitioner noted a laceration over the fourth proximal interphalangeal phalanx (PIP) with reddening of the surrounding tissues, and a course of oral antibiotics that have a broad spectrum against most Gram positive and Gram negative bacteria was prescribed for a presumed diagnosis of bacterial cellulitis (skin infection)… In October 2015, the patient again visited his general practitioner with worsening fourth finger swelling and erythema and a new fleshy nodule on the dorsal aspect of the left wrist. In November 2015, a rheumatologist injected steroids into the fourth PIP joint. In December 2015, the fourth PIP wound reopened and his entire left hand became red and swollen. The orthopedic team performed an initial washout with debridement, and amputation was considered. In February 2016, a second washout was performed from which deep tissue swabs showed non-nucleated acid-fast bacilli on a smear. A comprehensive medical history taken in February 2016 revealed that, in addition to the African gray parrot, the patient kept tropical fish and had cleaned the fish tank thoroughly following the parrot bite. The organism identified as the cause of this man’s infection is a naturally occurring aquatic organism found in freshwater and salt water. In humans, it predominantly causes soft tissue infections following exposure to contaminated water. The most common presentation is “fish tank granuloma”, i.e., hand infection following exposure to fish tank water. The majority of cases have a preceding injury to the hand (e.g., bites, abrasions, or puncture wounds) prior to the exposure that allowed entry of the organism through the dermis and into the soft tissue. Why do you think the initial course of antibiotics given in August 2014 were not effective at treating his infection? Use information about the cell structure of the etiological agent in your answer.