Alzheimer's disease causes memory loss and dementia in older adults through a neurodegenerative mechanism. Despite the pathophysiological clarification of this cognitive disorder, novel molecular and cellular pathways should be identified to determine its exact mechanism. Alzheimer's disease (AD) is pathologically characterized by senile plaques comprising beta‐amyloid and neurofibrillary tangles (NFTs) formed by hyperphosphorylated tau as a microtubule‐associated protein with a key role in the pathogenesis of AD. Periodontitis through inflammatory pathways is a risk factor for deteriorating cognitive impairment in AD patients. Poor oral hygiene coupled with immunocompromised status in older adults causes periodontal diseases and chronic inflammations through an oral bacterial imbalance. Toxic bacterial products, including bacteria themselves, can reach the central nervous system through the bloodstream and evoke inflammatory responses. The present review was conducted to investigate relationships between AD and periodontitis‐involved bacteria as a risk factor.

Background Acinetobacter baumannii is one of the most important hospital pathogenic bacteria that cause infectious diseases. The present study aimed to determine the frequency of carbapenem resistance genes in association with transposable elements and molecular typing of carbapenem-resistant A. baumannii bacteria collected from patients in Shiraz, Iran. Materials and Methods A total of 170 carbapenem-resistant A. baumannii isolates were obtained from different clinical specimens in two hospitals. The minimum inhibitory concentrations (MIC) of imipenem were determined and the prevalence of OXA Carbapenemases, Metallo-β-lactamases genes, insertion sequences (IS) elements, and transposons were evaluated by the polymerase chain reaction (PCR) method. Finally, molecular typing of the isolates was performed by the Enterobacterial Repetitive Intergenic Consensus-PCR method. Results The MICs ranged from 16 to 1,024 µg/mL for imipenem-resistant A. baumannii isolates. Out of the 170 carbapenem resistant A. baumannii isolates, bla OXA-24-like (94, 55.3%) followed by bla OXA-23-like (71, 41.7%) were predominant. In addition, A. baumannii isolates carried bla VIM (71, 41.7%), bla GES (32, 18.8%), bla SPM (4, 2.3%), and bla KPC (1, 0.6%). Moreover, IS Aba1 (94.2%) and Tn2009 (39.2%) were the most frequent transposable elements. Furthermore, (71, 44.0%) and (161, 94.7%) of the IS Aba1 of the isolates were associated with bla OXA-23 and bla OXA-51 genes, respectively. Besides (3, 1.7%), (1, 0.6%) and (5, 2.9%) of bla OXA-23 were associated with IS 18 , IS Aba4 , and IS Aba2 , respectively. Considering an 80.0% cut off, clusters and four singletons were detected. Conclusion According to the results, transposable elements played an important role in the development of resistance genes and resistance to carbapenems. The results also indicated carbapenem-resistant A. baumannii bacteria as a public health concern.

Background: Ox-bile has been recommended as a natural remedy with several therapeutic potentials in traditional Persian medicine (TPM). It has had efficacy against inflammation and infection according to traditional medicine. Evidence revealed that bile disrupts bacterial cell membrane and degrades DNA structure, so it has anti-bacterial effects. However, there is no evidence of any approved medication composed of ox-bile in Iran. Objectives: The aim of this study was to evaluate the in vitro anti-bacterial effects of ox-bile. Methods: Ox-bile was obtained under aseptic conditions and sterilized with a 0.22 µm syringe filter, then examined for their sterility status through culture on different media. Following incubation under aerobic cultures for 48 hours and the anaerobic cultures for one week. Two different kinds of antimicrobial susceptibility tests, including well-diffusion method and serial dilution test were employed to characterize the inhibitory effect of ox-bile extraction on Pseudomonas aeruginosa, Escherichia coli, Staphylococcus aureus, Staphylococcus epidermidis, and Propionibacterium acnes. Results: Based on our study, no anti-bacterial effect of ox-bile was observed against selected Gram-positive and Gram-negative bacteria. Conclusions: No in-vitro evidence of inhibitory effect was observed against studied gram-positive and gram-negative bacteria. Though further evaluation of the anti-bacterial effects of different preparations of ox-bile seems is still required.

: In recent years, Acinetobacter baumannii has attracted the research community’s attention since they are turned into the leading cause of both community- and hospital-acquired infections. The emergence of MDR-Acinetobacter baumannii strains threatens hospitalized patients since antibiotics fail to withdraw the bacterial infectious agents. Despite its worldwide distribution, health settings fail to combat limitations in therapeutic regions against Acinetobacter baumannii. The capability of biofilm formation in Acinetobacter baumannii strengthens their virulence and also survival. Understanding the fundamental virulence mechanisms beyond the microbial aggregations leads to exploring alternative drug targets such as signaling molecules and Quorum sensing systems to block bacterial communication and antimicrobial resistance. The significance of examining the biofilm's structural details and the relationship between Quorum sensing networks and related signaling molecules has been explicitly highlighted. Accordingly, this review study aimed to explain the general biofilm structure, the mechanisms beyond biofilm formation, quorum sensing system, and the generation of signaling molecules in Acinetobacter baumannii.