Nanotechnology and tuberculosis: An old disease with new treatment strategies.

Tuberculosis is an intracellular infectious disease caused by Mycobacterium tuberculosis, which mainly affects the lungs. Especially in patients infected by the Human Immunodeficiency Virus (HIV) or other immunosuppressed patients, tuberculosis is considered one of the infectious diseases with higher morbidity and mortality rates. Despite considerable improvements in diagnosis and treatment during the last decades, the drugs currently used in tuberculosis treatment still have limitations, such as low plasma levels after oral administration, low solubility in water, fast metabolization by the liver with a short 1/2 life and low patient adherence to treatment. Another limiting point is drug-resistant strains. Thus, to overcome such limitations, nanotechnology emerges as a promising alternative due to the drug release systems and its recent advances that show potential improvements, such as improved bioavailability and reduction of the therapeutic dose. In this context, this manuscript aimed to highlight the nanotechnology-based drug delivery systems studies pointing to those most effective for tuberculosis treatment. Studies based on polymeric nanoparticles are promising in diagnosing, treating, and even preventing tuberculosis because they have the high stability and transport capacity of these drugs. Solid lipid nanoparticles are another type of promising nanocarriers for treating tuberculosis, mainly for delivering drugs to the remote lymphatic system. Other promising nanosystems are the liposomes, since they have also shown efficacy in significantly reducing bacterial load compared to conventional drug administration. Given the results presented, the administration of drugs through nanotechnology-based drug delivery systems has benefits in treating tuberculosis since in vitro and in vivo studies have revealed that nanotechnology through nano- and micro-scale systems is an effective and promising approach for the treatment of tuberculosis. Furthermore, the increase in the number of patents for nanosystems aimed at treating TB has demonstrated researchers' commitment in the quest to improve the therapeutic arsenal against tuberculosis.

Antibacterial and antibiofilm potential of silver nanoparticles against antibiotic-sensitive and multidrug-resistant Pseudomonas aeruginosa strains.

Due to the severity of infections caused by P. aeruginosa and the limitations in treatment, it is necessary to find new therapeutic alternatives. Thus, the use of silver nanoparticles (AgNPs) is a viable alternative because of their potential actions in the combat of microorganisms, showing efficacy against Gram-positive and Gram-negative bacteria, including multidrug-resistant microorganisms (MDR). In this sense, the aim of this work was to conduct a literature review related to the antibacterial and antibiofilm activity of AgNPs against antibiotic-sensitive and multidrug-resistant Pseudomonas aeruginosa strains. The AgNPs are promising for future applications, which may match the clinical need for effective antibiotic therapy. The size of AgNPs is a crucial element to determine the therapeutic activity of nanoparticles, since smaller particles present a larger surface area of contact with the microorganism, affecting their vital functioning. AgNPs adhere to the cytoplasmic membrane and cell wall of microorganisms, causing disruption, penetrating the cell, interacting with cellular structures and biomolecules, and inducing the generation of reactive oxygen species and free radicals. Studies describe the antimicrobial activity of AgNPs at minimum inhibitory concentration (MIC) between 1 and 200 µg/mL against susceptible and MDR P. aeruginosa strains. These studies have also shown antibiofilm activity through disruption of biofilm structure, and oxidative stress, inhibiting biofilm growth at concentrations between 1 and 600 µg/mL of AgNPs. This study evidences the advance of AgNPs as an antibacterial and antibiofilm agent against Pseudomonas aeruginosa strains, demonstrating to be an extremely promising approach to the development of new antimicrobial systems.

Antimicrobial Resistance Profile and Biofilm Production of Microorganisms Isolated from Oropharynx of Rupornis magnirostris (Gmelin, 1788) and Caracara plancus (Miller, 1777).

The aim of this preliminary study was to identify microorganisms with antimicrobial resistance profile and biofilm producers in oropharynx of Rupornis magnirostris and Caracara plancus. Six R. magnirostris and six C. plancus maintained in Triage Center for Wild Animals (CETAS) facilities were studied. Coagulase-positive staphylococci (CoPS), enterobacteria, and yeasts were identified by the biochemical analysis or MALDI-TOF mass spectrometry. The resistance profile of the microorganisms was analyzed according to CLSI. The biofilm production was evaluated by Congo red and violet crystal staining methods. Among the 12 birds, 10 presented strains of CoPS and/or enterobacteria with resistance profile, such as methicillin-resistant CoPS (MR-CoPS), vancomycin-resistant CoPS (VR-CoPS), extended-spectrum ß-lactamase-producing Enterobacteriaceae (ESBL), and Klebsiella pneumoniae carbapenemase- (KPC-) producing bacteria. Regards the fungal analysis, Candida spp., Cryptococcus spp., Rhodotorula mucilaginosa, R. glutinis, and Trichosporon coremiiforme were identified. All the Trichosporon coremiiforme strains were resistant to amphotericin B, as well as all the Rhodotorula mucilaginosa exhibited resistance to fluconazole. Related to the biofilm production, among the 8 CoPS, 27 enterobacteria, and 10 yeasts isolates, 3, 16, and 7 strains were biofilm producers, respectively. Thus, the presence of these microorganisms in birds of prey is worrisome, highlighting its possible influence in the spread of infections in urban centers.