Background: Local surveillance of antimicrobial resistance is essential to guide empirical treatment strategies for respiratory tract infections. Long-term local data are particularly important in the context of rising global resistance and regional variations in antimicrobial susceptibility patterns, enabling clinicians to make informed empirical therapy decisions. Objectives: This study aimed to determine and compare antimicrobial resistance rates in Streptococcus pneumoniae (n = 335) and Haemophilus influenzae (n = 185) isolates obtained from community-acquired respiratory tract infections at Hacettepe University Hospital between 2010 and 2023. Methods: Streptococcus pneumoniae and H. influenzae isolates (one isolate per patient) recovered from sputum, tracheal aspirate, or bronchoalveolar lavage samples of patients with community-acquired pneumonia were included in the SENTRY surveillance program. Antimicrobial susceptibilities were determined by the microdilution method according to European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines (2025) using cation-adjusted Mueller–Hinton broth supplemented with lysed horse blood. Results: Penicillin non-susceptibility (I+R) was 67.2% in S. pneumoniae isolates (42.7% intermediate, 24.5% resistant), while ampicillin resistance in H. influenzae was 13.0%. All S. pneumoniae isolates remained fully susceptible to meropenem, linezolid, and vancomycin. Ceftaroline resistance rates were 1.5% in S. pneumoniae and 3.2% in H. influenzae. No resistance to ceftriaxone was detected among H. influenzae isolates. Conclusions: High rates of penicillin and macrolide non-susceptibility in S. pneumoniae limit the empirical use of these agents in our setting. In contrast, ceftriaxone and respiratory fluoroquinolones remain highly effective options for the empirical treatment of community-acquired respiratory tract infections. These findings underscore the importance of continuous local surveillance to support rational antimicrobial therapy.

Background: Rotaviruses are widely distributed throughout the world and cause serious water-borne infections in infants, children, adults, and individuals with weakened immune systems. These viruses enter environmental waters via wastewater discharge and pose a serious risk to public health. Objectives: The purpose of the present study is to monitor human rotavirus levels in Ahvaz's water and wastewater treatment systems. Methods: This study used the grab sampling method to collect 60 samples from two water treatment systems (including raw water inlet points, filtration outlet, and clean water tank outlet) and 48 samples from the influent and effluent of a wastewater treatment system in Ahvaz city. Water samples were concentrated with a 0.2-µm membrane filter cartridge and polyethylene glycol in a centrifuge, while wastewater samples were concentrated with both pellet and two-phase methods. For rotavirus detection, RNA isolation, complementary DNA (cDNA) synthesis, and amplification were performed with RVA primer by reverse transcription polymerase chain reaction (RT-PCR). The genotyping of rotavirus was performed using the multiplex nested reverse transcription polymerase chain reaction (MN-RT-PCR). Results: Out of the total samples collected, rotavirus was identified in 45 samples (41.66%) using RT-PCR. The efficiency of water treatment plant systems was 75%, and the efficiency of wastewater treatment plant systems in removing rotavirus was 60%. There was no significant difference between the rotaviruses identified in the influent and effluent samples of wastewater in different months of the year (P = 0.626). The most abundant genotypes identified were G9 and G10, with frequencies of 40% and 5%, respectively. Conclusions: The results showed that the water and wastewater treatment systems in Ahvaz are not efficient in eliminating rotaviruses. Therefore, continuous monitoring of human rotaviruses in water and wastewater to assess the efficiency of treatment systems and identify circulating genotypes for the appropriate design of human vaccines is recommended. There is also a need to use more appropriate processes for the removal of infectious viruses, such as ozone disinfection.

Background: Infective endocarditis (IE) is a severe cardiac infection involving microbial colonization of endocardial surfaces, primarily valves. Diagnosis is complex, requiring identification of the primary cardiac site and assessment of systemic complications. Objectives: This study aims to identify, monitor, and characterize nosocomial pathogens causing IE to enhance therapeutic strategies. Methods: This cross-sectional study was performed on 20 patients with IE in Namazi, Shahid Faqihi, and Qalb al-Zahra hospitals in Shiraz. Participants were Iranian adults (aged 18 - 80) presenting with initial symptoms of IE according to the modified Duke criteria. The study period was 18 months. All cases were evaluated by blood culture test. Then, by biochemical methods, known microorganisms were assessed. Finally, the genome of all known bacteria in IE was amplified by polymerase chain reaction (PCR) and then sequenced. GraphPad Prism 9.0 was used for statistical analysis. The chi-square and Fisher's exact tests were used to assess correlations (P-value < 0.05 considered significant). Results: Blood culture analysis in this IE cohort revealed 85% positivity (17/20 cases). Among positive cultures, Staphylococcus aureus (25%), Streptococcus spp. (20%), and S. epidermidis (15%) were the most prevalent pathogens. Notably, staphylococci collectively accounted for 74% of all pathogenic isolates. The affected population was predominantly male (highest percentage) within the 41 -60 year age range. Furthermore, antimicrobial susceptibility testing indicated markedly elevated rates of antibiotic resistance among the identified microorganisms. Conclusions: This study identifies Staphylococcus species, particularly S. aureus, as the predominant IE pathogens. The detection of fastidious organisms in culture-negative cases highlights the need to expand the etiological spectrum considered, especially in region-specific contexts. The high prevalence of antimicrobial resistance among isolates necessitates enhanced microbial surveillance and robust antibiotic stewardship. Rapid pathogen identification and molecular characterization remain critical for optimizing IE diagnostic and therapeutic management.

Background: Multidrug-resistant Acinetobacter baumannii infections present significant therapeutic challenges in intensive care unit (ICU) settings. Current evidence on optimal antimicrobial combinations remains limited. Objectives: This randomized controlled trial aims to compare the efficacy of dual versus triple antibiotic therapy in critically ill patients with carbapenem-resistant Acinetobacter infections. Methods: We conducted a single-center randomized controlled trial at Bohlool Hospital, Gonabad, Iran, between June 2024 and April 2025. Adult ICU patients with culture-confirmed carbapenem-resistant A. baumannii (CRAB) infections were randomly assigned (1:1) using block randomization to receive either dual therapy (colistin and ampicillin–sulbactam) or triple therapy (colistin, meropenem, and ampicillin–sulbactam). Outcome assessors were blinded to the treatment assignment. The primary outcome was 14-day clinical success. Secondary outcomes included 14- and 28-day mortality, final outcome, and hospital length of stay. Results: At day 14, clinical success was achieved in 14/23 (60.9%) dual-therapy versus 19/23 (82.6%) triple-therapy patients (P = 0.102). By day 28, mortality was significantly lower in the triple-therapy group (34.8% vs 65.2%; P = 0.039). There was no significant difference in overall in-hospital mortality (dual: 65.2% vs triple: 73.9%; P = 0.522). Time to discharge among survivors did not differ (P = 0.155). Conclusions: In this randomized controlled trial, adding meropenem to colistin and ampicillin–sulbactam was associated with reduced 28-day mortality in critically ill carbapenem-resistant Acinetobacter infections patients but did not significantly affect final outcome. Larger multicenter trials are warranted to confirm these findings and optimize combination regimens.

Background: Adult T-cell leukemia/lymphoma (ATLL) is a hematologic malignancy associated with human T-cell lymphotropic virus type 1 (HTLV-1) infection. Gene expression changes play a role in its pathogenesis. Objectives: In this study, we examined the gene expression profiles of alpha-actinin-4 (ACTN4), Tuberous Sclerosis Complex 2 (TSC2), C-X-C chemokine receptor type 4 (CXCR4), and Activating Transcription Factor 1 (ATF1) in Iranian ATLL patients for the first time, contrasting the findings with those from healthy controls. Methods: This case-control study (2023 - 2024) included 20 male Iranian participants (10 ATLL patients and 10 healthy controls). From each participant, 6 ml of whole blood was collected. Samples from eligible participants were screened for HTLV-1 infection using enzyme-linked immunosorbent assay (ELISA) and polymerase chain reaction (PCR). RNA was extracted and complementary DNA (cDNA) synthesis was performed. The expression of ACTN4, TSC2, CXCR4, ATF1, and viral HBZ genes was measured by Real-time PCR, using RPLP0 as the reference gene. Results: Expression of TSC2 and ACTN4 genes was significantly decreased in ATLL patients compared to healthy controls (TSC2: mean ± SD: 0.00003 ± 0.00004 vs. 0.00006 ± 0.00004, P < 0.05; ACTN4: 0.0129 ± 0.024 vs. 0.0207 ± 0.009, P < 0.05); CXCR4 and ATF1 expression levels were slightly increased but not significantly different between groups (CXCR4: 0.147 ± 0.154 vs. 0.139 ± 0.09, P > 0.05; ATF1: 0.0028 ± 0.0029 vs. 0.0015 ± 0.0009, P > 0.05). Conclusions: Dysregulation of target genes in ATLL patients suggests HTLV-1 involvement in disease progression by modulating host cellular pathways. Although CXCR4 and ATF1 showed non-significant upward trends, the observed downregulation of TSC2 and ACTN4 warrants further investigation in a larger sample size to clarify their potential roles in ATLL pathogenesis.

Background: Multidrug-resistant Pseudomonas aeruginosa (MDR-PA) poses a severe threat, with its pathogenicity heavily reliant on quorum sensing (QS). Fosfomycin (FOM), known for its biofilm penetration and synergy with other antibiotics. Objectives: In this study, the potential of FOM to inhibit QS and its virulence at sub-inhibitory concentrations was investigated. Methods: We determined the sub-MIC of FOM that does not affect bacterial growth. Its impact on virulence phenotypes (biofilm formation, swimming motility, pyocyanin production, protease activity) and QS gene expression (las, rhl, pqs systems) was assessed in vitro. Efficacy was further evaluated in a murine model of MDR-PA pneumonia. Results: Fosfomycin at 1/8 minimum inhibitory concentration (MIC; 0.25 μg/mL) did not alter Pseudomonas aeruginosa (PA) growth but significantly reduced swimming motility (P < 0.001), biofilm biomass (P < 0.001), pyocyanin (P < 0.001), and extracellular protease activity (P < 0.05). Quantitative real-time PCR (qRT-PCR) revealed marked downregulation of lasR (27 %), lasI (17 %), rhlR (54 %), rhlI (48 %), and pqsR (10 %) (all P < 0.01), whereas pqsE was unchanged. In vivo, FOM-treated mice exhibited less weight loss (P < 0.05), 100 % survival versus ~60 % in untreated (P < 0.01), reduced bronchoalveolar lavage fluid (BALF) cytokines (all P < 0.05), and preserved alveolar architecture. Conclusions: Sub-inhibitory FOM blunts Las/Rhl/Pqs QS circuits, modestly but consistently attenuates key virulence phenotypes, and protects against MDR-PA pneumonia. These findings support exploring FOM as a QS-targeting adjuvant in MDR-PA infections.

Background: The SARS-CoV-2 spike protein, a key component in viral entry, has been implicated in modulating inflammatory responses even in the absence of complete viral infection. Spike protein exposure can alter signaling pathways in colon epithelial cells, leading to increased expression of proinflammatory cytokines and disruption of epithelial barrier integrity. Objectives: This study evaluates the time-dependent effects of recombinant spike protein on proinflammatory gene expression and cytokine release in lung (BEAS-2B) and colon (CRL-1831) epithelial cells. Methods: BEAS-2B and CRL-1831 cells were treated with varying doses of spike protein, and samples were collected at 12, 24, 48, and 72 hours. Cell viability was assessed via XTT assay. Quantitative PCR (qPCR) was used to measure IFN-γ, TNF-α, IL-6, and IL-1β mRNA levels. Cytokine secretion was analyzed via ELISA. Results: In BEAS-2B cells, spike protein induced a transient increase in IFN-γ at early time points, followed by a reduction in IFN-γ and IL-6 at later times. Conversely, CRL-1831 cells demonstrated sustained or delayed increases in TNF-α and IFN-γ expression, with notable IL-6 fluctuation. ELISA data confirmed these trends in cytokine secretion profiles. No significant cytotoxicity was observed across the tested conditions. Conclusions: The spike protein elicits distinct temporal inflammatory responses in lung and colon epithelial cells, underscoring tissue-specific susceptibility and regulatory mechanisms in SARS-CoV-2 pathogenesis. While some previous studies have examined individual components of SARS-CoV-2, the present study's specific focus on the time-dependent, differential effects of the spike protein on two distinct epithelial cell types (lung and colon) appears to be a unique contribution to the field. These findings may contribute to understanding gastrointestinal and respiratory complications observed in COVID-19 patients.

Background: Epstein-Barr virus (EBV), a ubiquitous human herpesvirus, has gained increasing recognition as a potential driver of thyroid pathology through mechanisms extending beyond its classical lymphotropism. Viral latency, periodic reactivation, and molecular mimicry can initiate or amplify chronic thyroid inflammation, trigger autoimmune cascades, and promote nodular transformation. These viral–host interactions disturb the immune–endocrine axis, facilitating immune evasion and diminishing responsiveness to conventional surgical management. Traditional thyroidectomy, which overlooks the virological component, may thus contribute to overtreatment, recurrence, and loss of endocrine integrity. Objectives: This systematic review and meta-analysis aimed to elucidate the relationship between EBV infection and therapeutic outcomes of ultrasound-guided thyroid ablation, determining whether EBV-associated immune profiles influence lesion response, hormonal recovery, and recurrence risk. Methods: A comprehensive literature review and multicenter data synthesis were conducted, encompassing studies that employed radiofrequency ablation (RFA), ethanol ablation (EA), or minimally invasive video-assisted thyroidectomy (MIVAT) for benign or inflammatory thyroid lesions. Cases were stratified by EBV serostatus, viral load, antibody profile, lesion morphology, and inflammatory biomarkers. Clinical, laboratory, and imaging parameters were analyzed following PRISMA 2020 guidelines to assess correlations between EBV-related immune alterations and post-ablation outcomes. Results: Image-guided ablation achieved substantial nodule volume reduction (70 - 90%) and effective hormonal stabilization in most patients. However, EBV-positive cases displayed distinct immunological patterns, characterized by elevated cytokine levels, delayed lesion resolution, and intermittent thyroid function fluctuations, especially in those with active inflammatory phenotypes. Precision ultrasound targeting allowed dynamic energy modulation to preserve surrounding structures, thereby minimizing procedural complications. Conclusions: The findings underscore the importance of adopting a virology-informed approach to thyroid ablation. EBV profiling may serve as a prognostic determinant for optimizing treatment selection, predicting endocrine recovery, and mitigating recurrence risk. Integration of viral diagnostics with image-guided ablation represents a forward step toward targeted, less invasive management of EBV-associated thyroid disease. Future studies should focus on validating EBV-specific biomarkers and developing combined immuno-ablative strategies to enhance long-term durability and precision of treatment outcomes.

Background: Leishmaniasis, a neglected tropical disease, impacts millions, especially in resource-limited areas. Objectives: This study examines the chemical composition and anti-leishmanial potential of Zataria multiflora and Thymus vulgaris essential oils against Leishmania major, a key cause of cutaneous leishmaniasis (CL). Methods: The chemical composition of Z. multiflora and T. vulgaris essential oils was analyzed by gas chromatography-mass spectrometry (GC-MS). Their anti-leishmanial effects against L. major promastigotes (31.25 - 1000 µg/mL) were evaluated via flow cytometry, while anti-amastigote activity was determined by counting infected macrophages using light microscopy. Cytotoxicity against J774 cells was assessed with the MTT assay after 48 hours. Results: The main compounds in T. vulgaris and Z. multiflora essential oils were thymol (49.83% and 46.46%, respectively), along with γ-terpinene (14.93%) and cymene (10.99%) in the former, and carvacrol (32.47%) in the latter. Both oils showed activity against L. major promastigotes (IC50 = 92.75 and 59.69 µg/mL, respectively) and amastigotes (48 hours) (IC50 = 100.68 and 87.28 µg/mL, respectively). Cytotoxicity on J774 cells (CC50 = 820.4 and 799.6 µg/mL) resulted in Selectivity Indices (SI) of 8.84 (promastigote) and 8.14 (amastigote) for T. vulgaris, and 13.39 (promastigote) and 9.16 (amastigote) for Z. multiflora. In the promastigote assay, amphotericin B [20 µg/mL, positive control (PC)] caused 89.71% mortality, confirming assay validity. Conclusions: This study demonstrates the anti-leishmanial potential of Z. multiflora and T. vulgaris essential oils against L. major, but further in vivo validation is required.

Background: The most frequent bacterial agent associated with purulent and non-purulent complications of pharyngitis is group A beta-hemolytic Streptococcus (GAS). Objectives: This study aimed to compare the frequency of GAS in children with pharyngitis and those without pharyngitis, emphasizing the problem of antibiotic overuse and bacterial resistance. Methods: This descriptive cross-sectional study was conducted from summer to winter 2014 on children aged 2 - 15 years visiting the Pediatric Emergency Department with sore throat complaints. Bacterial pharyngitis was clinically diagnosed, and throat swabs were collected before antibiotic use. Healthy children without infection symptoms were selected as controls. All specimens were cultured on blood agar, and results were analyzed using chi-square tests. Results: Among 100 patients with pharyngitis and 100 healthy controls, GAS was isolated from 18% and 8%, respectively (P = 0.03). The frequency of anterior cervical adenopathy and fever was significantly higher in culture-positive patients. Conclusions: The prevalence of GAS pharyngitis in children was 18%. Overdiagnosis and irrational antibiotic prescriptions remain common. Strengthening diagnostic accuracy and antibiotic stewardship is essential to prevent resistance and complications.