Nanotechnology improves the detection of bacteria: Recent advances and future perspectives.

Nanotechnology has advanced significantly, particularly in biomedicine, showing promise for nanomaterial applications. Bacterial infections pose persistent public health challenges due to the lack of rapid pathogen detection methods, resulting in antibiotic overuse and bacterial resistance, threatening the human microbiome. Nanotechnology offers a solution through nanoparticle-based materials facilitating early bacterial detection and combating resistance. This study explores recent research on nanoparticle development for controlling microbial infections using various nanotechnology-driven detection methods. These approaches include Surface Plasmon Resonance (SPR) Sensors, Surface-Enhanced Raman Scattering (SERS) Sensors, Optoelectronic-based sensors, Bacteriophage-Based Sensors, and nanotechnology-based aptasensors. These technologies provide precise bacteria detection, enabling targeted treatment and infection prevention. Integrating nanoparticles into detection approaches holds promise for enhancing patient outcomes and mitigating harmful bacteria spread in healthcare settings.

Genomic diversity of ß-lactamase producing Pseudomonas aeruginosa in Iran; the impact of global high-risk clones.

BACKGROUND: Hospital-acquired infections caused by multidrug-resistant Pseudomonas aeruginosa incline hospital stay and costs of treatment that resulted in an increased mortality rate. The frequency of P. aeruginosa high-risk clones producing carbapenemases was investigated in our clinical samples. METHODS: In this cross-sectional study, 155 non-repetitive P. aeruginosa isolates were included from different medical centers of Iran. Antibiotic susceptibility testing was determined, and the presence of ß-lactamases were sought by phenotypic and genotypic methods. The clonal relationship of all isolates was investigated, and multi-locus sequence typing (MLST) was used for finding the sequence types of carbapenemase-producers. RESULTS: The agent with highest percent susceptibility rate was recorded for colistin (94.9%). MOX and FOX were found both as low as 1.95% (3/155). The most frequent narrow spectrum ß-lactamase was SHV with 7.7% (12/155) followed by PER, OXA-1, and TEM with the frequency of 7.1% (11/155), 3.2% (5/155), and 1.3% (2/155), respectively. Carbapenemases were detected in 28 isolates (18%). The most frequent carbapenemase was IMP with 9% (14/155) followed by NDM, 8.4% (13/155). OXA-48 and VIM were also detected both per one isolate (0.65%). MLST of carbapenem resistant P. aeruginosa isolates revealed that ST244, ST664, ST235, and ST357 were spread in subjected clinical settings. REP-PCR uncovered high genomic diversity in our clinical setting. CONCLUSION: Clonal proliferation of ST235 strain plays a key role in the propagation of MDR pattern in P. aeruginosa. Our data showed that high-risk clones has distributed in Iran, and programs are required to limit spreading of these clones.

The global prevalence of gastric cancer in Helicobacter pylori-infected individuals: a systematic review and meta-analysis.

BACKGROUND: Helicobacter pylori is a gastrointestinal pathogen that infects around half of the world's population. H. pylori infection is the most severe known risk factor for gastric cancer (GC), which is the second highest cause of cancer-related deaths globally. We conducted a systematic review and meta-analysis to assess the global prevalence of GC in H. pylori-infected individuals. METHODS: We performed a systematic search of the PubMed, Web of Science, and Embase databases for studies of the prevalence of GC in H. pylori-infected individuals published from 1 January 2011 to 20 April 2021. Metaprop package were used to calculate the pooled prevalence with 95% confidence interval. Random-effects model was applied to estimate the pooled prevalence. We also quantified it with the I2 index. Based on the Higgins classification approach, I2 values above 0.7 were determined as high heterogeneity. RESULTS: Among 17,438 reports screened, we assessed 1053 full-text articles for eligibility; 149 were included in the final analysis, comprising data from 32 countries. The highest and lowest prevalence was observed in America (pooled prevalence: 18.06%; 95% CI: 16.48 - 19.63; I2: 98.84%) and Africa (pooled prevalence: 9.52%; 95% CI: 5.92 - 13.12; I2: 88.39%). Among individual countries, Japan had the highest pooled prevalence of GC in H. pylori positive patients (Prevalence: 90.90%:95% CI: 83.61-95.14), whereas Sweden had the lowest prevalence (Prevalence: 0.07%; 95% CI: 0.06-0.09). The highest and lowest prevalence was observed in prospective case series (pooled prevalence: 23.13%; 95% CI: 20.41 - 25.85; I2: 97.70%) and retrospective cohort (pooled prevalence: 1.17%; 95% CI: 0.55 - 1.78; I 2: 0.10%). CONCLUSIONS: H. pylori infection in GC patients varied between regions in this systematic review and meta-analysis. We observed that large amounts of GCs in developed countries are associated with H. pylori. Using these data, regional initiatives can be taken to prevent and eradicate H. pylori worldwide, thus reducing its complications.

Detection of efflux pump genes in multiresistant Acinetobacter baumannii ST2 in Iran.

Acinetobacter baumannii, as a nosocomial pathogen has become a worldwide concern in recent years. In the current study, the resistance to tetracyclines and colistin were assessed in the isolates from different provinces of Iran.During the timeline of this study, a number of 270 isolates of A. baumannii were collected from tracheal aspirates, wounds, urine and blood cultures. The minimum inhibitory concentration (MIC) for tetracycline, doxycycline, minocycline, tigecycline and colistin were evaluated. Tetracycline resistance genes were assessed by PCR. The mean expression level of adeB, adeJ and adeG were assessed using semi quantitative Real-Time PCR. The clonal relationship of the isolates was evaluated by the repetitive extragenic palindromic PCR (REP-PCR), International Clonal (IC) Lineage Multiplex PCR and multilocus sequence typing (MLST) (Pasteur scheme) methods.The MIC by microdilution method showed that 87.5, 51.4, 28, 0.74 and 0% of the isolates were resistant to tetracycline, doxycycline, minocycline, tigecycline and colistin respectively. The prevalence of tetracycline resistance genes was 99.2, 99.2, 98, 86.7, 10, 3.33, 0.37, 0% for adeB, adeJ, adeG, tetB, tetA(39), tetA, tetM and tetH in tetracycline-resistant isolates. Moreover, the expression level of adeB, adeJ, adeG genes in tigecycline-nonsusceptible A. baumannii (TNAB) strain was higher compared to the tigecycline-susceptible A. baumannii (TSAB). A broad genomic diversity was revealed, but ST2 was the most prevalent ST. Our results indicated that tetracycline resistance in Iran is mediated by resistance-nodulation-cell division (RND) and tetB efflux pumps.