Molecular Characterization of ß-Lactam Resistance and Antimicrobial Susceptibility to Possible Therapeutic Options of AmpC-Producing Multidrug-Resistant Proteus mirabilis in a University Hospital of Split, Croatia.

This study was performed to elucidate genetic relatedness and molecular resistance mechanisms of AmpC-producing multidrug-resistant Proteus mirabilis isolates in University Hospital of Split (UHS), and define efficient antibiotics in vitro. A total of 100 nonrepeated, consecutive, amoxicillin/clavulanate- and cefoxitin-resistant P. mirabilis isolates were collected, mostly from urine (44%) and skin and soft-tissue samples (30%). They were all positive in cefoxitin Hodge test and negative for extended spectrum beta-lactamase production. Pulsed field gel electrophoresis identified four clusters and two singletons, with 79% of isolates in dominant cluster. Molecular characterization and I-CeuI analysis of representatives revealed blaCMY-16 gene located on chromosome, and insertion element ISEcp1 positioned 110 pb upstream of blaCMY-16 starting codon. They also harbored blaTEM-1, except one with blaTEM-2. They were all resistant to trimethoprim-sulfamethoxazole, all but one to quinolones, and 81% to all aminoglycosides, while 77% were susceptible (S) and 22% intermediate (I) to piperacillin/tazobactam, and 4% were S and 68% I to cefepime. Only 15% were S to ceftolozane/tazobactam. Meropenem, ertapenem, ceftazidime/avibactam, temocillin, and fosfomycin were 100% efficient in vitro. This is the first report of blaCMY-16 gene in P. mirabilis from hospital samples in Croatia. The findings are in accordance with Italian and Greek reports. The clonal nature of outbreak suggests the high potential of clonal spread. Alternative agents should be considered to spare carbapenem usage.

Prompt diagnosis and effective treatment of Trichosporon asahii catheter-related infection in non-immunocompromised neurosurgical patient.

Trichosporon asahii is a rare but emerging fungal pathogen that causes severe and life-threatening infections with high mortality rate, mostly in immunocompromised patients. It could be easily misdiagnosed due to lack of awareness, especially when invasive or deep-seated infections occur in non-immunocompromised patients, and inadequately treated since the clinical failures and high minimum inhibitory concentrations to some antifungal agents have been described. We present a case of T. asahii catheter-related infection in 66-year-old comatose patient with polytrauma, who was not immunodeficient, but was receiving broad-spectrum antibiotics for a long period. Due to prompt diagnosis and treatment which included catheter replacement and voriconazole, the patient successfully recovered from this infection. The aims of this case report were to highlight the importance of recognizing this otherwise colonizing yeast as potentially dangerous pathogen in non-immunocompromised patients with a long-term antibiotic therapy, and to emphasize the importance of the right therapeutic choice due to its resistance to certain antifungal agents.