Leuconostoc mesenteroides periprosthetic knee infection, an unusual fastidious Gram-positive bacteria: a case report.

BACKGROUND: Periprosthetic joint infections are mainly caused by Gram-positive cocci. Leuconostoc mesenteroides is a rare microorganism mainly causing bloodstream infections. At times, it might be confused with another type of cocci and give rise to misdiagnosed infections. Molecular diagnosis and biofilm production comprise important techniques to guide antibiotic treatment. CASE PRESENTATION: A 68-year-old Hispanic female with a previous history of bilateral knee arthroplasty presented with acute right-knee inflammation and gait impairment. Blood tests showed inflammatory response and knee x-ray revealed no prosthesis loosening. Irrigation and debridement was performed. Gram-positive cocci were obtained from cultures, and then biochemical and molecular identification revealed L. mesenteroides. Susceptibility and biofilm production were performed. The patient was treated with IntraVenous (IV) Ceftriaxone for ten days and was then switched to Amoxicillin-Clavulanate for 3 months with clinical and laboratory success. CONCLUSIONS: Microbiology diagnosis of fastidious microorganisms is mandatory to treat periprosthetic joint infections adequately. L. mesenteroides may infect non-immunocompromised persons; however, treatment guidelines are lacking.

Microbiology and Infection Profile of Electric Burned Patients in a Referral Burn Hospital in Mexico City.

Electrical burn injuries are one of the most severe forms of trauma. This study aims to investigate the infection complications in electrical burn patients in a referral hospital in Mexico City. A longitudinal retrospective study was conducted, involving electrical burn patients admitted from April 2011 to December 2016. Demographic and clinical data including type of electric burns, infection complications, and mortality was sought. Data were collected at admission and daily until discharge. Number and type of infections and microorganism isolations were sought. Risk factors for death were analyzed. A total of 111 patients were included, of which 96.4% were males, mean age of 31.6±16.22, most injuries were high voltage associated. The total body surface area average was 27.8% ± 19.63. The overall infection rate was 72.9 cases per 100 patients. Mortality was observed in 4 (3.6%) patients. About 59.1% (443/749) had growth for Gram-negative bacteria. Multidrug-resistant Pseudomonas aeruginosa was the most frequent microorganism isolated. Fungi were present in 4.9% of cases. Electrical burn injuries occurred in young males in our study. Infection was frequent, most of them caused by Gram-negative rods with an important rate of antimicrobial resistance; however, an important microbial diversity was present.