Concomitant tuberculosis and aspergillosis in patients with COVID-19: a case report.

Coexisting pulmonary aspergillosis and tuberculosis in a post-COVID-19 patient is rare. Here, we are going to report a case of combined pulmonary aspergillosis and tuberculosis in a 51-year-old female who was previously diagnosed with COVID-19 pneumonia. The patient was treated with voriconazole and anti-tuberculosis agents.

The effect of mesenchymal stem cell conditioned medium incorporated within chitosan nanostructure in clearance of common gastroenteritis bacteria in-vitro and in-vivo.

Gastroenteritis infection is a major public health concern worldwide, especially in developing countries due to the high annual mortality rate. The antimicrobial and antibiofilm activity of human mesenchymal stem cell-derived conditioned medium (hMSCsCM) encapsulated in chitosan nanoparticles (ChNPs) was studied in vitro and in vivo against common gastroenteritis bacteria. The synthesized ChNPs were characterized using Zeta potential, scanning electron microscopy (SEM), and dynamic light scattering (DLS) techniques. HMSC-derived conditioned medium incorporated into chitosan NPs (hMSCsCM-ChNPs) composite was fabricated by chitosan nanoparticles loaded with BM-MSCs (positive for CD73 and CD44 markers). The antimicrobial and antibiofilm activity of composite was investigated against four common gastroenteritis bacteria (Campylobacter jejuni ATCC29428, Salmonella enteritidis ATCC13076, Shigella dysenteriae PTCC1188, and E. coli ATCC25922) in-vitro and in-vivo. Majority of ChNPs (96%) had an average particle size of 329 nm with zeta potential 7.08 mV. The SEM images confirmed the synthesis of spherical shape for ChNPs and a near-spherical shape for hMSCsCM-ChNPs. Entrapment efficiency of hMSCsCM-ChNPs was 75%. Kinetic profiling revealed that the release rate of mesenchymal stem cells was reduced following the pH reduction. The antibacterial activity of hMSCsCM-ChNPs was significantly greater than that of hMSCsCM and ChNPs at dilutions of 1:2 to 1:8 (P < 0.05) against four common gastroenteritis bacteria. The number of bacteria present decreased more significantly in the group of mice treated with the hMSCsCM-ChNPs composite than in the groups treated with hMSCsCM and ChNPs. The antibacterial activity of hMSCsCM against common gastroenteritis bacteria in an in vivo assay decreased from > 106 CFU/ml to approximately (102 to 10) after 72 h. Both in vitro and in vivo assays demonstrated the antimicrobial and antibiofilm activities of ChNPs at a concentration of 0.1% and hMSCsCM at a concentration of 1000 µg/ml to be inferior to that of hMSCsCM-ChNPs (1000 µg/ml + 0.1%) composite. These results indicated the existence of a synergistic effect between ChNPs and hMSCsCM. The designed composite exhibited notable antibiofilm and antibacterial activities, demonstrating optimal release in simulated intestinal lumen conditions. The utilization of this composite is proposed as a novel treatment approach to combat gastroenteritis bacteria in the context of more challenging infections.

Investigation of the Antibacterial and Antibiofilm Activity of Selenium Nanoparticles against Vibrio cholerae as a Potent Therapeutics.

Vibrio cholerae is a major cause of severe diarrhea, which is ecologically flexible, and remains as a major cause of death, especially in developing countries. Consecutive emergence of antibiotic-resistant strains is considered to be as one of the major concerns of the World Health Organization (WHO). Nanoparticles as a new nonantibiotic therapeutic strategy have been widely used in recent years to treat bacterial infections. The present study aimed to investigate the antibacterial and antibiofilm effect of selenium nanoparticles (SeNPs) in vitro against V. cholerae O1 ATCC 14035 strain. SeNPs were prepared and characterized using ultraviolet-visible (UV-Vis) spectroscopy, DLS (dynamic light scattering), zeta potential measurement, and Fourier transform infrared (FTIR) analysis. The concentration of SeNPs was calculated by ICP (inductively coupled plasma) method. Also, 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide (MTT) assay was employed to assess the cytotoxic effect of SeNPs on Caco-2 cells. Antibacterial and antibiofilm activity of SeNPs was determined by broth microdilution and crystal violet assays, respectively. The average particle size of SeNPs was 71.1 nm with zeta potential -32.2 mV. The SEM images supported the uniform spherical morphology of the prepared nanoparticles. The antibiofilm effect of SeNPs was evident at concentrations of 50-200 µg/mL. This study results provided evidence that SeNPs are safe as an antibacterial and antibiofilm agent against V. cholerae O1 ATCC 14035 strain.

Formulation of selenium nanoparticles encapsulated by alginate-chitosan for controlled delivery of Vibrio Cholerae LPS: A novel delivery system candidate for nanovaccine.

The lipopolysaccharide (LPS) of Vibrio cholerae plays a significant role in stimulating primary protection and immune responses. LPS delivery has been limited by the stimulation of inflammatory cytokines. This work aimed to report the synthesis and performance of this formulation in modulating immune responses and protecting LPS against acidic gastric medium. Alg-Cs-LPS-SeNPs composite was fabricated by an ionic cross-linking/in situ reduction method. Cytokines TNF-α, IL-6, IL-10, and TGF-ß were assessed after cells were incubated with different compounds of the system. The main outcomes revealed that encapsulation of LPS-loaded SeNPs in the alginate-chitosan complex was associated with a high entrapment efficiency and could effectively protect LPS against acidic GIT medium. Kinetic profiling revealed that LPS was more slowly released from LPS-loaded Alg-Cs-LPS-SeNPs at pH 1.2, 7.4, and 6.8. These results indicated that Alg-Cs-LPS-SeNPs composite was able to significantly increase anti-inflammatory cytokines and reduce the release of pro-inflammatory cytokines. Thus, these findings show that this system for LPS delivery could be easily biosynthesized and encapsulated for use in the pharmaceutical industry. This study provides proof of the potential for future use of oral LPS vaccines, concomitantly inducing immunomodulatory effects.

Sensitivity of levofloxacin in combination with ampicillin-sulbactam and tigecycline against multidrug-resistant Acinetobacter baumannii.

BACKGROUND AND OBJECTIVES: The selection of alternative treatment options with antibiotic combinations may be used for successful managing of multidrug-resistant Acinetobacter baumannii. The aim of this study was to determine the synergistic effects of ampicillin-sulbactam combined with either levofloxacin or tigecycline against MDR A. baumannii. MATERIALS AND METHODS: A total 124 of A.baumannii isolates collected from clinical samples of hospitalized patients which assessed for antibiotic susceptibility using disk diffusion method. E-test was used on 10 MDR A. baumannii isolates to determine the minimum inhibitory concentration (MIC) of ampicillin-sulbactam, levofloxacin and tigecycline. Any synergistic effects were evaluated at their own MIC using E-test assay at 37°C for 24 hours. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. RESULTS: Levofloxacin plus ampicillin-sulbactam combination was found to have synergistic effects (FIC index: ≤0.5) in 90% of the isolates, but there was no synergistic effect for ampicillin-sulbactam/tigecycline and tigecycline/levofloxacin combination. The antagonist effect in 50% of isolates (FIC index: >2) showed in combination of levofloxacin/tigecycline. CONCLUSION: The emergence of multidrug A. baumannii isolates requires evaluating by combination therapy. The combination of levofloxacin plus a bactericidal antibiotic such as ampicillin-sulbactam is recommended. Results should be confirmed by clinical studies.

Susceptibility Pattern and Distribution of Oxacillinases and bla PER-1 Genes among Multidrug Resistant Acinetobacter baumannii in a Teaching Hospital in Iran.

Acinetobacter baumannii (A. baumannii) is an important nosocomial pathogen in healthcare institutions. ß-Lactamase-mediated resistance is the most common mechanism for carbapenem resistance in A. baumannii. The aim of this study was to determine the antibiotic resistance pattern, to detect OXA encoding genes, class A, bla PER-1, and to detect the presence of ISAba1. A total of 124 A. baumannii isolates were collected from hospitalized patients in a teaching hospital in Kashan, Iran. The susceptibility of isolates to different antibiotics was determined by disk-diffusion method. PCR was used to detect bla PER-1, bla OXA-23, bla OXA-24, bla OXA-51, bla OXA-58, and ISAba1 genes. All isolates were resistant to ceftazidime, ceftriaxone, and cefotaxime. All of the isolates revealed susceptibility to polymyxin B and colistin. Ninety-six percent of the isolates were extensive drug resistance (XDR), 5.6% extended spectrum beta-lactamase (ESBL), and 54.8% metallo-beta-lactamase (MBL). All isolates were positive for bla OXA-51 and ISAba1. bla OXA-23, bla OXA-24, and bla OXA-58 were found in 79.8%, 25%, and 3.2%, respectively. The frequency rate of bla PER-1 gene was 52.4%. Multidrug resistant A. baumannii isolates are increasing in our setting and extensively limit therapeutic options. The high rate presence of class D carbapenemase-encoding genes, mainly bla OXA-23 carbapenemases, is worrying and alarming as an emerging threat in our hospital.