TiO2 Nanocomposite Coatings and Inactivation of Carbapenemase-Producing Klebsiella Pneumoniae Biofilm-Opportunities and Challenges

The worldwide increase of multidrug-resistant Gram-negative bacteria is a global threat. The emergence and global spread of Klebsiella pneumoniae carbapenemase- (KPC-) producing Klebsiella pneumoniae represent a particular concern. This pathogen has increased resistance and abilities to persist in human reservoirs, in hospital environments, on medical devices, and to generate biofilms. Mortality related to this microorganism is high among immunosuppressed oncological patients and those with multiple hospitalizations and an extended stay in intensive care. There is a severe threat posed by the ability of biofilms to grow and resist antibiotics. Various nanotechnology-based strategies have been studied and developed to prevent and combat serious health problems caused by biofilm infections. The aim of this review was to evaluate the implications of nanotechnology in eradicating biofilms with KPC-producing Klebsiella pneumoniae, one of the bacteria most frequently associated with nosocomial infections in intensive care units, including in our department, and to highlight studies presenting the potential applicability of TiO2 nanocomposite materials in hospital practice. We also described the frequency of the presence of bacterial biofilms on medical surfaces, devices, and equipment. TiO2 nanocomposite coatings are one of the best long-term options for antimicrobial efficacy due to their biocompatibility, stability, corrosion resistance, and low cost; they find their applicability in hospital practice due to their critical antimicrobial role for surfaces and orthopedic and dental implants. The International Agency for Research on Cancer has recently classified titanium dioxide nanoparticles (TiO2 NPs) as possibly carcinogenic. Currently, there is an interest in the ecological, non-toxic synthesis of TiO2 nanoparticles via biological methods. Biogenic, non-toxic nanoparticles have remarkable properties due to their biocompatibility, stability, and size. Few studies have mentioned the use of nanoparticle-coated surfaces as antibiofilm agents. A literature review was performed to identify publications related to KPC-producing Klebsiella pneumoniae biofilms and antimicrobial TiO2 photocatalytic nanocomposite coatings. There are few reviews on the antibacterial and antibiofilm applications of TiO2 photocatalytic nanocomposite coatings. TiO2 nanoparticles demonstrated marked antibiofilm activity, but being nano in size, these nanoparticles can penetrate cell membranes and may initiate cellular toxicity and genotoxicity. Biogenic TiO2 nanoparticles obtained via green, ecological technology have less applicability but are actively investigated.

Therapeutic Plasma Exchange in Catastrophic Antiphospholipid Syndrome (CAPS): A Rare Case Report and Literature Review

BACKGROUND/AIM

Catastrophic antiphospholipid syndrome (CAPS) may be the first manifestation ("de novo") of antiphospholipid syndrome (APS) or a complication in the clinical course of patients known to have this syndrome. Approximately 40% of patients had an associated autoimmune disease, mainly, systemic lupus erythematosus (SLE). The trigger can be one of the following: infections, surgical interventions, neoplasms, pregnancy, discontinuation of anticoagulant treatment, and others. CAPS is a medical emergency in which early identification and prompt initiation of aggressive therapy is extremely important. According to the Guidelines for the use of Therapeutic Apheresis in Clinical Practice developed by the American Society for Apheresis (ASFA), last updated in April 2023, in CAPS, the indication for therapeutic plasma exchange (TPE) is category I, grade 2C.

CASE REPORT

We present a case of probable CAPS secondary to systemic lupus erythematosus (SLE) in an elderly patient in whom clinical and biological improvement was achieved through a multidisciplinary approach and prompt initiation of TPE. Because TPE is considered first-line therapy in CAPS, we initiated the procedure as soon as the attending rheumatologist raised this suspicion. Four plasmapheresis sessions were performed in the Intensive Care Unit. We used TPE by membrane filtration. Following the therapeutic intervention with TPE, corticotherapy (Solumedrol in puls-therapy), cyclophosphamide and anticoagulant treatment, the evolution was favourable, with clinical and biological improvement.

CONCLUSION

The prompt initiation of TPE, because of the suspicion of CAPS, increases the chances of a favourable evolution.