Occurrence of Acinetobacter baumannii genomic resistance islands (AbGRIs) in Acinetobacter baumannii strains belonging to global clone 2 obtained from COVID-19 patients.

AIM: The Acinetobacter baumannii genomic resistance islands (AbGRIs), which were characterized in the genome of the global clone 2 (GC2) A. baumannii contain resistance genes. Here, we aimed to determine the occurrence of AbGRIs in GC2 A. baumannii obtained from COVID-19 patients in a referral hospital in Tehran, Iran. METHODS: A total of 19 carbapenem-resistant A. baumannii (CRAB) isolates belonging to GC2 and sequence type 2 (ST2), including 17 from COVID-19 patients and two from the devices used in the ICU that the COVID-19 patients were admitted, were examined in this study. Antibiotic susceptibility testing was performed by the disk diffusion method. PCR and PCR mapping, followed by sequencing, were performed to characterize the structure of AbGRI resistance islands in the isolates tested. RESULTS: The AbGRI3 was the most frequent resistance island (RI) detected, present in all the 19 isolates, followed by AbGRI1 (15 isolates; 78.9%) and AbGRI2 (three isolates; 15.8%). Notably, AbGRIs were identified in one of the A. baumannii strains, which was isolated from a medical device used in the ICU where COVID-19 patients were admitted. Furthermore, new structures of AbGRI1 and AbGRI3 resistance islands were found in this study, which was the first report of these structures. CONCLUSIONS: The present study provided evidence for the circulation of the GC2 A. baumannii strains harboring AbGRI resistance islands in a referral hospital in Tehran, Iran. It was found that resistance to several classes of antibiotics in the isolates collected from COVID-19 patients is associated with the resistance genes located within AbGRIs.

Bilateral hip septic arthritis caused by nontyphoidal Salmonella group D in a 16-year-old girl with COVID-19: A case report.

INTRODUCTION AND IMPORTANCE: Nontyphoidal Salmonella infection can lead to gastroenteritis, enteric fever, and bacteremia. However, joint infections due to this bacterium are rare, and usually associated with immunosuppressive disorders. CASE PRESENTATION: A 16-year-old girl, with a recent history of acute lymphocytic leukemia (ALL) presented with bacteremia, and bilateral hip pain after COVID-19 symptoms. Clinical presentation, laboratory features and imaging showed bilateral nontyphoidal Salmonella septic arthritis. We administered antibiotics, based on antibiotics susceptibility pattern of the isolated Salmonella. CLINICAL DISCUSSION: The case is presented because reports of bilateral hip joint infection due to nontyphoidal Salmonella are rare especially after COVID-19. When the patient presents with joint discomfort, the clinician should think infection especially in immunocompromised hosts. CONCLUSION: It illustrates successful management of septic arthritis requires prompt clinical diagnosis, microorganism identification, administration of appropriate systemic antibiotics and hip joint surgery.

Fungal and bacterial co-infections of the respiratory tract among patients with COVID-19 hospitalized in intensive care units.

Backgrounds: The pandemic of COVID-19 has created a global public health crisis. ICU patients with COVID-19 are prone to infections of bacterial and/or fungal origins due to several risk factors. Consequently, the current study was conducted to evaluate the frequency, demographic characteristics, underlying conditions, and etiologic agents of fungal and bacterial co-infections of the respiratory tract among ICU patients with COVID-19 in Iran. Materials and methods: From May to October 2020, sputa and endotracheal aspirates were collected from ICU patients hospitalized with COVID-19 who also were suspected of bacterial and/or fungal co-infections according to inclusion criteria. The etiologic agents of bacterial co-infections were identified using the Vitek 2 identification method. For fungal identification, all samples were analyzed by direct microscopy using KOH 10% and culture. Furthermore, all isolates were subjected to sequencing method. Results: A total of 73 lung specimens were obtained from patients who met the inclusion criteria. Of these, in 15 cases (20.54%) fungal and/or bacterial co-infections were confirmed. Males were more infected (73.33%) and all of them were between 49 and 79 years. Candida albicans (n = 8, 61.53%) and Klebsiella pneumoniae (n = 5, 38.46%) were the most frequent etiologic agents related to fungal and bacterial co-infections, respectively. Pneumonia (n = 15, 100%) and diabetes mellitus (n = 8, 53.33%) were documented as the most prevalent underlying conditions. In the current study, 3 out of 15 patients (20%) died. Conclusion: The frequency of bacterial co-infections of the respiratory tract in ICU patients hospitalized with COVID-19 was relatively high. According to the results, one of the causes of death of these patients could be a secondary infection.

Cerium oxide NPs mitigate the amyloid formation of α-synuclein and associated cytotoxicity.

AIM: Among therapeutic proposals for amyloid-associated disorders, special attention has been given to the exploitation of nanoparticles (NPs) as promising agents against aggregation. METHODS: In this paper, the inhibitory effect of cerium oxide (CeO2) NPs against α-synuclein (α-syn) amyloid formation was explored by different methods such as Thioflavin T (ThT) and 8-anilinonaphthalene-1-sulfonic acid (ANS) fluorescence spectroscopy, Congo red adsorption assay, circular dichroism (CD) spectroscopy, transmission electron microscopy (TEM), and bioinformatical approaches. Also, the cytotoxicity of α-syn amyloid either alone or with CeO2 NPs against neuron-like cells (SH-SY5Y) was examined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT), flow cytometry, and quantitative real-time polymerase chain reaction (Bax and Bcl-2 gene expression) assays. RESULTS: ThT and ANS fluorescence assays indicated that CeO2 NPs inhibit the formation of aggregated species and hydrophobic patches of α-syn in amyloidogenic conditions, respectively. Congo red and CD assays demonstrated that CeO2 NPs reduce the formation of amyloid species and ß-sheets structures of α-syn molecules, respectively. TEM investigation also confirmed that CeO2 NPs limited the formation of well-defined fibrillary structures of α-syn molecules. Molecular docking and dynamic studies revealed that CeO2 NPs could bind with different affinities to α-syn monomer and amyloid species and fibrillar structure of α-syn is disaggregated in the presence of CeO2 NPs. Moreover, cellular assays depicted that CeO2 NPs mitigate the cell mortality, apoptosis, and the ratio of Bax/Bcl-2 gene expression associated with α-syn amyloids. CONCLUSION: It may be concluded that CeO2 NPs can be used as therapeutic agents to reduce the aggregation of proteins and mitigate the occurrence of neurodegenerative diseases.