Alireza Ekrami

Colorectal cancer is a major cause of cancer-related mortality worldwide. Nanotechnology has introduced nanoparticles as a promising therapeutic approach in cancer treatment. Gold nanoparticles (AuNPs) can influence critical cellular processes in cancer cells. This study evaluates the effects of chitosan-coated gold nanoparticles (CH-AuNPs) on cell viability, mitochondrial membrane potential, reactive oxygen species (ROS) production, and apoptosis-related gene expression in the human colorectal adenocarcinoma HT-29 cell line. CH-AuNPs were synthesized and characterized using dynamic light scattering (DLS), UV-Vis spectroscopy, and atomic force microscopy (AFM). Cell viability was assessed using the MTT assay. Apoptosis, mitochondrial membrane potential (Δψm), and ROS production were analyzed via flow cytometry using Annexin V-FITC/PI, Rhodamine 123, and DCFH-DA, respectively. A clonogenic assay was used to measure colony-forming ability, and real-time qPCR was performed for gene expression analysis. The nanoparticles had an average size of 12.3 nm. The IC50 was 33 µM (approximately 6.5 µg/mL). They significantly reduced colony formation, decreased mitochondrial membrane potential, and induced apoptosis in HT-29 cells. ROS levels remained unchanged. BAX, Caspase-3, and CYT C gene expression increased, while anti-apoptotic BCL2 expression decreased. Chitosan-coated gold nanoparticles exhibit cytotoxic and apoptotic effects on HT-29 cells under in vitro conditions. These preliminary findings suggest the need for further investigation, including validation in additional colorectal cancer cell lines, assessment of selectivity, and in vivo studies, before any therapeutic application can be considered.

In recent decades, fungal infections of the central nervous system (CNS) have increased significantly. Of more than 100,000 identified fungal species, approximately 10 to 15% are responsible for implicated fungal-related neurological diseases. A significant clinical manifestation of fungal infections of the CNS is meningitis, a serious condition marked

Introduction: Accurate laboratory results are critical in guiding patient treatment pathways, underscoring the necessity of implementing quality control programs to enhance laboratory services. This study evaluates the outcomes of 30 external quality control cycles in microbiology conducted in Iran over a decade (2013–2023). Data were retrieved from the website of the Iranian Association of Clinical Laboratory Scientists and analyzed using SPSS software. Results: The findings indicate that over 95% of laboratories submitted responses, with more than 97% of submissions deemed valid. The highest and lowest rates of correct identification were observed for Escherichia coli in cycle 45 (92.5%) and Aeromonas hydrophila in cycle 22 (3.9%), respectively. The mean rates of correct, partially correct, and combined correct/partially correct identifications were 42.3%, 20.3%, and 62.7%, respectively. Of the 30 cycles evaluated, 9 focused on Gram-positive bacteria and 21 on Gram-negative bacteria. The mean correct identification rate for Gram-positive bacteria (59.3%) exceeded that for Gram-negative bacteria (34.1%), though no statistically significant difference was observed. The mean correct identification rate for acid-fast bacteria was 57.2%, raising significant concerns. Conclusion: The results of this study reveal an unfavorable landscape of laboratory diagnostic performance in this field, highlighting the need for prioritized attention in national planning and policy-making.

Seyed Mohammad Sadegh Pezeshki, Najmadin Saki, Mehran Varnaseri Ghandali, Alireza Ekrami, Arshid Yousefi Avarvand. Blood Res 2021;56:38-43. https://doi.org/10.5045/br.2021.2020189

Objectives.Incidence of methicillin-resistantStaphylococcus aureus(MRSA) is increasing every year, especially in burn patients with a high rate of morbidity and mortality. Molecular and epidemiologic studies are useful practices for understanding the relatedness of isolates in a single patient or a hospital. This study aimed at determining molecular characterizations of isolates collected in 2006 and 2014 usingS. aureus-specific staphylococcal protein A (Spa) typing and Multilocus Sequence Typing (MLST) methods.Materials and Methods. Totally, 71 MRSA isolates were collected during the last two studies (2006 and 2014) from burn patients at Taleghani Burn Centre. After confirmation, all isolates were analysed using MLST andSpatyping methods.Results. We reported the emergence of Spa type t021, ST-30-IV MRSA isolates, which were PVL-positive in 14.6% of the cases and t12366, ST-8-IV isolates, which were PVL-negative in 9.8% of the cases. In 2014 study, Spa typing of MRSA isolates revealed five different spa types. Overall, in two studies, t037, ST-239, SCCmecIII, and CC8 were predominant clones and they were reported in 63% of the cases.Conclusion. The predominance of ST-239 in this region during the last eight years is a major concern. It also has a disturbing impact on the management of staphylococcal infections. Moreover, the SCCmectype IV strain is able to disseminate rapidly in hospital environments, demanding an improvement in infection-control policy.

The objective of this study was to determine the frequency of the antimicrobial resistance and genes encoding virulence factors of enterococci isolated in hospitalized burn patients in a major burn center in Ahvaz, southwest of Iran. A total of 340 bacterial isolates were collected from the burn center from February 2014 to February 2015. The antimicrobial susceptibility and MIC of vancomycin were determined using the disk diffusion and micro-agar dilution techniques. The genus and species-specific genes, potential virulence genes, and vanA and vanB genes were detected by polymerase chain reaction. According to our results, out of the 340 bacterial isolates, 16.4% (n = 56) were identified as enterococci. Out of the 56 enterococcal isolates, 35 (62.5%) were Enterococcus faecalis and 21 (37.5%) were Enterococcus faecium. More than 20% (n = 5) of E. faecium demonstrated resistance to vancomycin. The gelE and asa genes were the most prevalent virulence genes in E. faecalis (48.5%) and E. faecium (43%) isolates. The emergence of vancomycin resistant E. faecium strains which have several virulence factors should be considered as a major cause of concern for burn centers. Control and management of infections induced by enterococci should be regarded as highly important in burn patients.

Background: Pseudomonas aeruginosa is among the most problematic hospital and community-acquired pathogens. Toxin-antitoxin (TA) systems are maintenance regulatory systems in bacteria and have recently been considered new targets for antimicrobial therapy. The prevalence and transcription of these systems in clinical isolates are still unknown. Objectives: The aim of this study was to characterize three types of TA systems (parDE, relBE, and higBA) among P. aeruginosa clinical isolates. Materials and Methods: We typed our clinical isolates by ERIC-PCR (enterobacterial repetitive intergenic consensus sequence-based polymerase chain reaction) and BOX-PCR. We then investigated 174 P. aeruginosa clinical isolates from three hospitals in Ahvaz, Iran, for the presence of TA system genes, and determined whether these systems were encoded on chromosomes or plasmids by amplification of the flanking regions. Results: Our results showed that in the 174 P. aeruginosa isolates, relBE and higBA were universal, but parDE was less prevalent. Both of the flanking regions of the parDE genes in all positive isolates were amplified. The flanking regions of nearly all relBE genes were amplified. Amplification was observed for the downstream sequence of every higBA locus, as well as for the region upstream of higBA, except in 14 strains. Conclusions: Based on the presence of TA systems in the majority of P. aeruginosa isolates, these could be used as a novel target for antimicrobial therapy. Keywords: Gene Regulatory Networks; Resistance; Genotyping; Pseudomonas aeruginosa

Methicillin resistance Staphylococcus aureus (MRSA) and coagulase negative staphylococci (MRCoNS) have recognized as the major cause of nosocomial infections that threat the burn patient's life. The aims of this study were to determine the frequency of MRSA and MRCoNS and their antibiotic resistance patterns among burn patients in a burn center in Ahvaz, Iran. A total of 340 clinical specimens: (80%) wound and (20%) blood were obtained from patients in Taleghani burn hospital during February 2013–2014. Staphylococci species identification and antibiogram were performed by standard procedures using disk diffusion method. The Methicillin resistance strains were detected by Etest and PCR using mecA specific primers. Out of 30.2% (103) isolates that were recognized as staphylococci, 82 % (84) and 18% (19) were identified as S. aureus and coagulase negative staphylococci (CoNS) respectively. Resistance to methicillin was detected in 60% and 63% of the S. aureus and CoNS isolates respectively. Seven different antimicrobial resistance patterns observed among methicillin resistant staphylococci. The MRSA and MRCoNS strains showed closed resistance phenotypes. All the methicillin resistant isolates showed a high rate resistance to the other studied antibiotics in comparison to methicilin sensitive isolates. Vancomycin and imipenem showed the greatest effect against methicillin resistant isolates. During 8 years in the studied burn hospital, no significant changes in the methicillin resistance staphylococci frequency were detected. The presence of multi resistant MRSA and MRCoNS strains is cause of concern in burn hospitals. Vancomycin remains as a drug of choice for methicillin resistance staphylococci infections.