Discordance of the Urinary and Pleural Fluid Antigen Test and False Positive for Streptococcus pneumoniae in Empyema Secondary to Necrotizing Bacterial Pneumonia.

Empyema is a severe complication of pneumonia with high morbidity and mortality rates. Rapid diagnosis and tailoring of antibiotic therapy are crucial to treatment success for these severe bacterial lung infections. A Streptococcus pneumoniae (S. pneumonia) antigen test drawn from the pleural fluid rather than a urine sample has been found to have equivalent diagnostic utility to the urinary antigen test. Discordance between these tests is rare. We report a case of a 69-year-old female with CT imaging findings consistent with empyema and a bronchopulmonary fistula. A rapid S. pneumonia antigen test was negative from the urinary sample but positive when drawn from a patient's pleural fluid sample. Final pleural fluid cultures resulted in Streptococcus constellatus (S. constellatus). This case demonstrates discordance between the results of urinary and pleural fluid S. pneumoniae antigen tests, representing a potential pitfall in using rapid antigen testing on pleural fluid samples. False positives for the S. pneumoniae antigen in patients with viridans streptococci infections have been documented due to the cross-reactivity of cell wall proteins in different streptococcal species. Physicians encountering bacterial pneumonia of unknown etiology complicated by empyema should understand the potential for discordance and false positives using this diagnostic method.

Gemella haemolysans: Rare case of automatic implantable cardioverter-defibrillator (AICD) lead infection.

We present a rare case of Gemella haemolysans automated implantable cardioverter defibrillator (AICD) lead infection. Gemella species are catalase-negative, facultative anaerobic, Gram-positive cocci which are found in normal human oral flora. Gemella are often incorrectly identified on routine Gram stain and culture, requiring advanced techniques such as PCR. Gemella has been shown to be a rare cause infective endocarditis in case reports; however, there has not been a report of an isolated AICD lead infection. AICD infections with gram positive organisms other than Staphylococcus species has been associated with more aggressive infections and higher mortality. Standard treatment for Gemella consists of ß-lactam inhibitors and aminoglycosides. In this case, we present an alternative antibiotic treatment with vancomycin and ceftriaxone. A case series for Gemella haemolysans endocarditis, without lead infection, reported the use of vancomycin and ceftriaxone with good results. This approach is similar to methicillin-resistant staphylococcus aureus (MRSA) bacteremia salvage therapy. In addition, this case highlights the importance of culture and sensitivity in the selection of antibiotics, particularly avoiding nephrotoxic drugs when possible.

The Effects of Radiofrequency or Cryothermal Ablation on Biomechanical Properties of Isolated Human or Swine Cardiac Tissues.

Changes in cardiac tissue properties following the application of various ablation modalities may lead to the development of an array of associated complications. The application of either radio frequency (RF) or cryothermal ablations will alter the biomechanical properties of various cardiac tissues in a differential manner; in some cases, this may be attributable to increased incidences of cardiac tamponade, pulmonary vein stenosis, and/or atrial-esophageal fistula. Thus, a greater understanding of the underlying changes in tissue properties induced by ablative therapies will ultimately promote safer and more efficacious procedures. The effects of applied RF or cryothermal energies on the biomechanical properties of the pulmonary vein, left atrial, or right atrial samples ([Formula: see text]) were examined from fresh excised porcine ([Formula: see text]) and donated human tissue ([Formula: see text]). RF ablations were found to reduce the tensile strength of the porcine cardiac specimens ([Formula: see text]), and a similar trend was noted for human samples. Cryoablations did not have a significant impact on the tissue properties compared with the untreated tissue specimens. Locational and species differences were also observed in this experimental paradigm ([Formula: see text]. Incorporating these findings into cardiac device design and computational modeling should aid to reduce the risks of complications associated with tissue property changes resulting from cardiac ablative procedures.