A SYMPHONY BY STREPTOCOCCUS PYOGENES. Parker Youst, Thomas Tran, Will Benton, MD; Louisiana State University, Baton Rouge, LA.
Introduction: Understanding pathogenetic mechanisms is essential to recognizing and treating common diseases. A patient with Streptococcus pyogenes (also known as Group A Streptococcus [GAS]) infection illustrates this point. Case: A 52-year-old female with class III obesity presented with a desquamative skin rash beginning three days after onset of pharyngitis, fevers, and chills. She also complained of pain in her knees and ankles. Physical examination revealed tachycardia and multiple skin findings: a tense bulla on the abdomen, a well-demarcated erythematous plaque to the lower abdomen, with retiform purpura and ulceration. She had a diffuse morbilliform eruption with a sandpaper- like texture on all four extremities and trunk with desquamation on her back, arms, and lower abdomen. Her tongue was large, erythematous, and strawberry-like. Laboratory abnormalities included WBC of 37k, CRP>320 mg/L, lactic acid of 3.4 mmol/L, and elevated creatinine. Oropharyngeal strep screen was positive. Empiric vancomycin and piperacillin- tazobactam were administered. Blood cultures remained negative. A CT of the abdomen and pelvis revealed no evidence of an infectious source. Tissue biopsy showed marked papillary dermal edema and numerous bacteria in the epidermis and dermis.
Tissue culture grew Streptococcus pyogenes. Her skin erythema, pharyngitis, and arthralgias improved with antibiotic therapy. She was transitioned to amoxicillin/clavulanate upon discharge. Discussion: Infectious organisms can demonstrate pathogenicity by three mechanisms: (1) direct effect of the organism; (2) toxin production; (3) immunologic response to the organism. This case illustrates the diverse clinical spectrum of GAS and its ability to manifest disease by all three of these mechanisms. This patient’s erythematous skin lesion with sharply demarcated borders is consistent with erysipelas, which is a classic consequence of direct GAS invasion. Contained within her erysipelas lesion was evidence of purpura which on biopsy revealed retiform purpura, a vascular phenomenon that occurs when GAS angioinvasion compromises blood vessels serving the skin resulting in downstream cutaneous ischemia, purpura, and necrosis. Additionally, GAS can cause disease by producing toxins. GAS’s exotoxins led to the enlarged “strawberry” tongue and the desquamating skin rash, commonly seen in scarlet fever. As a final pathogenic mechanism, this patient’s bilateral, fixed arthralgias were likely secondary to immunologic sequelae of her GAS infection.
ACHROMOBACTER XYLOSOXIDANS BACTEREMIA IN A HEMODIALYSIS PATIENT WITH AV GRAFT INFECTION: A CASE REPORT. Susmitha D. Chalamalasetti, Deekshitha Manney, Harikrishna Bandla, Imran Ali Khan; St Francis Medical Center, Monroe, LA.
Introduction: Achromobacter xylosoxidans is an emerging multidrug-resistant gram-negative opportunistic pathogen primarily associated with respiratory infections in cystic fibrosis (CF) patients. In non-CF patients, it has been identified as a causative agent particularly in the immunocompromised and those with indwelling medical devices. Although infections by A. xylosoxidans are rare, their clinical significance has been increasing.
days. Initial labs showed leukocytosis and mild lactic acidosis. Blood cultures were drawn, and the patient was admitted for suspected sepsis, initially managed with piperacillin-tazobactam and vancomycin. Final blood cultures grew A. xylosoxidans and despite continued treatment, the patient did not improve clinically. Her leukocytosis continued to worsen and repeat blood cultures remained positive for three subsequent sets. Despite transitioning to imipenem- cilastatin based on sensitivity profiles, bacteremia persisted. Infectious disease suspected the left upper extremity AV graft as the infection source. After discussions with nephrology, the decision was made to remove the AV graft. Purulent material was found 22
Case: A 63-year-old female with a history of end stage renal disease on hemodialysis presented with generalized weakness and poor oral intake for several
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