Unique North American isolates of severe metastatic hypervirulent Klebsiella pneumoniae strain infections with hepatic abscesses seen in young patients within Texas.

Rationale: Hypervirulent Klebsiella pneumoniae (hvKp) infections have principally been identified in Asia. Within a two-month period, two patients between the ages of 30 to 50 years old presented to a tertiary referral hospital in Texas with septic shock, hepatic abscess, and septic thrombophlebitis. Blood cultures were positive for Klebsiella pneumoniae (isolates 2020CK-00441 and 2021CK-00720 respectively).

Enterobacteriaceae Growth Promotion by Intestinal Acylcarnitines, a Biomarker of Dysbiosis in Inflammatory Bowel Disease.

Background & Aims: Altered plasma acylcarnitine levels are well-known biomarkers for a variety of mitochondrial fatty acid oxidation disorders and can be used as an alternative energy source for the intestinal epithelium when short-chain fatty acids are low. These membrane-permeable fatty acid intermediates are excreted into the gut lumen via bile and are increased in the feces of patients with inflammatory bowel disease (IBD).

Methods: Herein, based on studies in human subjects, animal models, and bacterial cultures, we show a strong positive correlation between fecal carnitine and acylcarnitines and the abundance of Enterobacteriaceae in IBD where they can be consumed by bacteria both in vitro and in vivo.

Microbubble cavitation restores Staphylococcus aureus antibiotic susceptibility in vitro and in a septic arthritis model.

Treatment failure in joint infections is associated with fibrinous, antibiotic-resistant, floating and tissue-associated Staphylococcus aureus aggregates formed in synovial fluid (SynF). We explore whether antibiotic activity could be increased against Staphylococcus aureus aggregates using ultrasound-triggered microbubble destruction (UTMD), in vitro and in a porcine model of septic arthritis. In vitro, when bacterially laden SynF is diluted, akin to the dilution achieved clinically with lavage and local injection of antibiotics, amikacin and ultrasound application result in increased bacterial metabolism, aggregate permeabilization, and a 4-5 log decrease in colony forming units, independent of microbubble destruction.

Floating Biofilm Formation and Phenotype in Synovial Fluid Depends on Albumin, Fibrinogen, and Hyaluronic Acid.

Biofilms are typically studied in bacterial media that allow the study of important properties such as bacterial growth. However, the results obtained in such media cannot take into account the bacterial localization/clustering caused by bacteria-protein interactions and the accompanying alterations in phenotype, virulence factor production, and ultimately antibiotic tolerance. We and others have reported that methicillin-resistant or methicillin-susceptible (MRSA or MSSA, respectively) and other pathogens assemble a proteinaceous matrix in synovial fluid.