Background: Infections caused by drug-resistant Klebsiella pneumoniae represent a significant and growing global problem. Bacteriophages are viruses that target specific bacteria and represent a promising alternative to antibiotics for eradicating bacterial infections. Objectives: This study investigated the therapeutic effect of a phage cocktail on wounds infected with clinical and standard K. pneumoniae (ATCC® BAA-1705) strains. Methods: Specific bacteriophages were isolated from hospital sewage samples. An infectious wound model was established in Wistar rats, and the effects of a hydroxypropyl methylcellulose (HPMC) gel containing a phage cocktail were evaluated in animals with infected wounds compared with gentamicin. Finally, the antibacterial and wound-healing effects of combination therapy (HPMC gel containing phage cocktail + gentamicin) were investigated in vivo. Results: The results revealed that a single dose of a phage cocktail significantly reduced the mortality rate in rats with K. pneumoniae wound infection. We also observed that combination therapy (phage cocktail + gentamicin) significantly accelerated infected wound healing and reduced the number of bacterial colonies and the mortality rate in rats. Conclusions: Complementary therapy using a phage cocktail in combination with antibiotics may be a promising approach for treating infected wounds. Infections caused by drug-resistant K. pneumoniae represent a significant and growing problem worldwide.
Background: Actinomycetes can colonize the oral cavity of HIV-infected patients and may cause opportunistic infections. The use of commonly prescribed antimicrobials to treat these infections may contribute to the development of antimicrobial resistance (AMR). Objectives: This study aimed to assess the antimicrobial susceptibility of actinomycetes isolated from the oral cavities of HIV-infected patients in Tehran, Iran. The susceptibility of the isolates to the essential oils (EOs) of thyme and ajwain was also evaluated. Methods: Samples were previously collected from 200 HIV-infected participants and 85 healthy participants using oral swabs and inoculated into thioglycolate media. The isolated bacteria were characterized phenotypically and genotypically. The antimicrobial susceptibility of the isolates to 14 antimicrobials was then assessed. In addition, the susceptibility of the isolates to the EOs of thyme and ajwain was evaluated. Results: Overall, actinomycetes were identified in 6.5% of HIV-infected patients and 3.5% of healthy controls. Most isolates were multidrug resistant (MDR) to amoxicillin, clindamycin, erythromycin, nalidixic acid, penicillin G, and tetracycline but were susceptible to gentamicin, ciprofloxacin, amikacin, linezolid, trimethoprim-sulfamethoxazole, and nitrofurantoin. All isolates were also susceptible to the herbal EOs. Conclusions: The findings demonstrated that the Actinomycetes isolates were MDR to several antimicrobials, including some listed by the World Health Organization (WHO) as first-line agents for treating major bacterial infections. This study highlights the importance of early diagnosis and appropriate treatment of Actinomycetes-associated infections and further suggests that the EOs of thyme and ajwain may be considered therapeutic options alongside conventional antimicrobial regimens.
Background: Carbapenem-resistant Acinetobacter baumannii (CRAB) is an important cause of fatal drug-resistant infection in the intensive care unit (ICU). Thus, it is crucial to identify strategies to reduce the occurrence of CRAB infection. Although studies have revealed that CRAB is associated with invasive operations, little research has assessed the relationship between the occurrence of CRAB infections and different types of invasive procedures in patients with pulmonary infections in the ICU. Objectives: The present study explored the relationships between specific invasive procedures and CRAB infection to provide evidence for the clinical prevention and control of CRAB. Methods: This single-center retrospective analysis was conducted in the ICU and electronic ICU of Jiangsu Provincial Hospital of Traditional Chinese Medicine. Patients diagnosed with pulmonary infection caused by AB between June 2020 and December 2024 were enrolled. Patients were categorized according to the presence or absence of CRAB infection, and invasive operation types and mortality rates were compared between these groups. The factors affecting CRAB infection were analyzed by least absolute shrinkage and selection operator (LASSO) regression analysis. Patients were further divided into three groups based on the duration of deep venous catheterization, and the relationship between the risk of CRAB infection and the duration of catheterization was examined using multivariate regression models. Results: In total, 341 patients were included, with 216 patients in the CRAB group and 125 patients in the AB group. The 28-day all-cause mortality rate was higher in the CRAB group (52.8% vs. 38.4%; P < 0.001). Endotracheal intubation (odds ratio [OR] = 7.28, 95% confidence interval [CI] = 3.81 - 13.92), chronic obstructive pulmonary disease (OR = 0.32, 95% CI = 0.14 - 0.77), a higher CURB-65 score (OR = 1.53, 95% CI = 1.16 - 2.02), and a longer duration of deep venous catheterization (6 - 10 days: OR = 2.39, 95% CI = 1.15 - 4.97; ≥ 10 days: OR = 10.56, 95% CI = 4.52 - 24.67) increased the risk for CRAB infection. In the fully adjusted model, the rate of CRAB infection was significantly higher in patients catheterized for 6 - 10 days (OR = 2.49, 95% CI = 1.16 - 5.34) or ≥ 10 days (OR = 12.63, 95% CI = 5.22 - 30.59). Conclusions: Tracheal intubation and prolonged deep venous catheterization in the ICU increased the risk of CRAB infection and reduced survival among patients with pulmonary infection. Thus, the duration of deep venous catheterization and the use of tracheal intubation in the ICU should be minimized to reduce the risk of CRAB infection.
Background: Mycoplasma hominis and M. genitalium have been associated with reproductive health issues and may contribute to infertility, although causal links remain unclear. Data on their prevalence and antimicrobial susceptibility in southern Iran are limited. Objectives: To assess the molecular prevalence, species distribution, and antimicrobial susceptibility of M. hominis and M. genitalium among fertile and infertile individuals in Bandar Abbas, Hormozgan province, southern Iran. Methods: In this cross-sectional study conducted in 2024, 200 participants (100 infertile and 100 fertile) provided clinical samples — 100 semen samples from men and 100 endocervical swabs from women. Fertility status was clinically confirmed for all participants. Samples were enriched in pleuropneumonia-like organism (PPLO) broth, analyzed by polymerase chain reaction (PCR) targeting the 16S rRNA gene for genus-level detection, followed by multiplex PCR for species identification. Minimum inhibitory concentrations (MIC) for azithromycin, erythromycin, and moxifloxacin were determined using the 96-well microdilution method. Data were analyzed using SPSS v29, with P < 0.05 considered statistically significant. Results: Among 200 samples, 41 (20.5%) were positive for Mycoplasma: 22 men (20 infertile, 2 fertile) and 19 women (16 infertile, 3 fertile). Multiplex PCR identified 26 isolates as M. genitalium (12 infertile men, 2 fertile men; 10 infertile women, 2 fertile women) and 15 isolates as M. hominis (8 infertile men, 0 fertile men; 6 infertile women, 1 fertile woman). Although minor differences were observed between sexes (22% of men vs 19% of women), these were not statistically significant (P > 0.05). Macrolide resistance was detected in 6 M. genitalium and 4 M. hominis isolates, while moxifloxacin resistance was rare, found in only one M. genitalium isolate. Conclusions: Mycoplasma hominis and M. genitalium are present in both fertile and infertile individuals in southern Iran, with higher macrolide resistance in M. genitalium. While these organisms may influence reproductive health, causal associations cannot be confirmed. Routine molecular detection and species-specific antimicrobial testing are recommended, and larger longitudinal studies are needed to clarify their potential role in infertility.
Background: Mycoplasma pneumoniae is a major respiratory pathogen. Accurate and timely diagnosis is critical for guiding treatment, as clinical symptoms overlap with those of other respiratory pathogens. Molecular assays, particularly fluorescent PCR, offer higher sensitivity and specificity but typically require time-consuming nucleic acid extraction steps, prolonging the detection process to over 1 hour. Objectives: This study aimed to develop a rapid and efficient method for direct sample analysis to overcome the limitations of conventional, time-consuming methods for M. pneumoniae detection. Methods: Primers and probe were designed based on conserved regions of the P1 gene. The specificity of primers and probe was verified by BLAST analysis. Assay conditions were optimized by adjusting primer/probe concentrations and two-stage annealing/extension parameters. Specificity was evaluated using 322 throat swab samples (including 32 M. pneumoniae-positive samples) collected from Jiaxing hospitals in 2024. Sensitivity was assessed by testing serial dilutions of M. pneumoniae positive control, with the detection limit calculated by probit analysis. Reproducibility was determined by intra- and inter-assay variability. The performance of the newly developed assay was compared with a commercial fluorescent PCR kit using 10-fold diluted M. pneumoniae-positive samples. Results: Melting curve analysis revealed that by 86°C, nearly all amplification products had completely denatured, which was used for denaturation in the second amplification stage. Optimal assay conditions included a primer concentration of 1 µM, a probe concentration of 0.6 µM, and annealing/extension conditions of 65°C for 10 s in the first stage and 60°C for 5 s in the second stage. The assay showed high specificity with no cross-reactivity to other respiratory pathogens. Sensitivity analysis indicated that the limit of detection of the assay in 95% of cases was 553.26 copies/mL (95% CI: 341.32 - 2063.47 copies/mL). The method demonstrated good reproducibility, with intra-assay variability of 1.86% and 3.17%, and inter-assay variability of 3.73% and 4.70% at 2500 and 1000 copies/mL, respectively. Head-to-head comparison using the same set of 10-fold diluted clinical samples demonstrated that the newly developed assay achieved a higher detection rate (62.5%, 20/32) than the commercial fluorescent PCR kit (53.1%, 17/32). Conclusions: The developed extraction-free fluorescent PCR offers a rapid, simple, and reliable approach for M. pneumoniae detection. It shows promise for clinical applications, particularly in outpatient settings requiring prompt diagnosis.
Background: Pseudomonas aeruginosa species cause damage in various plant tissues by overcoming host defenses through the production of effectors and toxins. Pseudomonas aeruginosa infects Arabidopsis thaliana using multiple bacterial genes involved in virulence and adaptation. Objectives: The aim of this study was to identify the mexR gene in P. aeruginosa and investigate its potential role in infection and tissue damage in Arabidopsis thaliana Methods: Twelve plants per bacterial strain were used for infection assays. Disease symptoms were recorded daily to evaluate infection over a five-day period. The mexR gene was amplified from P. aeruginosa genomic DNA using PCR. Results: Water-soaking and yellow discoloration of infected leaves were observed two days after infection. An increase in colony-forming units (CFUs) was detected from day 0 to day 2, followed by only slight increases from day 2 to day 5. Out of fifteen P. aeruginosa strains tested, three strains were positive for the mexR gene. Conclusions: Pseudomonas aeruginosa isolates exhibited a notable prevalence of the efflux pump regulatory gene mexR. This study provides evidence supporting an association between P. aeruginosa infection and tissue damage in Arabidopsis thaliana.
Background: Microbial culture media contain complex nutrient components such as yeast extract, peptides, and carbohydrates, which exhibit inherent redox properties. These baseline antioxidant activities can interfere with assays assessing the radical scavenging ability of microbial metabolites, particularly when media-derived effects are not properly controlled. Objectives: To quantitatively evaluate the intrinsic 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) radical scavenging capacities of five commonly used microbial media and to assess how media composition and sterilization methods contribute to assay interference. Methods: Five commercial liquid media — Tryptic Soy Broth (TSB), de Man-Rogosa-Sharpe (MRS) broth, Luria-Bertani (LB) broth (Miller), Nutrient Broth (NB), and Yeast extract-Malt extract (YM) broth — were tested for ABTS radical scavenging activity. Media were sterilized using either autoclaving (121°C, 20 min) or 0.22 μm syringe filtration. Radical scavenging (%) was calculated from absorbance at 734 nm after 15 min incubation with ABTS⁺ working solution. IC₅₀ values were determined by four-parameter logistic regression. Results: Baseline antioxidant capacity varied significantly depending on media composition, with the following potency order: MRS > TSB ≈ LB > YM > NB. Autoclaving further enhanced radical scavenging activity, particularly in carbohydrate-rich media such as MRS, likely due to the formation of melanoidin-like antioxidant compounds via heat-induced chemical reactions such as the Maillard reaction. Conclusions: Media-derived radical scavenging effects have substantial potential to confound antioxidant assays. Consideration of both media selection and sterilization method is essential to avoid misinterpretation of microbial functionality. This study provides practical guidance for minimizing assay interference and establishing reliable conditions in antioxidant-related microbiological research.
Background: Seasonal influenza A virus (IAV) continues to pose a substantial global health threat because of its high mutation rate, widespread prevalence, and the ongoing challenge of timely detection, particularly in resource-limited settings. Objectives: To address this gap, we developed and analytically evaluated a novel colorimetric reverse transcription loop-mediated isothermal amplification (RT-LAMP) assay for the rapid, sensitive, and visually interpretable detection of seasonal IAV. Methods: Ten reported LAMP primer sets previously reported were initially screened for amplification efficiency using certified reference RNA materials from H1N1 and H3N2 as templates. Analytical sensitivity was assessed using serial dilutions of quantified RNA standards, and specificity was rigorously evaluated through both in silico analysis and experimental testing with a panel of common respiratory pathogens. Results: Sensitivity analyses based on triplicate serial dilution testing revealed preliminary limits of detection as low as 67 copies per reaction for H1N1 and 42 copies per reaction for H3N2, with performance matching or exceeding that reported in previous LAMP-based studies. No cross-reactivity with other respiratory pathogens was observed, confirming the high specificity of the assay. The assay targets the conserved matrix protein gene and detects IAV broadly; however, it does not differentiate between the H1N1 and H3N2 subtypes in a single reaction. Notably, incorporation of hydroxy naphthol blue (HNB) enabled direct visual detection via a distinct color change from violet to sky blue within 45 minutes under isothermal conditions, thereby eliminating the need for advanced instrumentation. Conclusions: The assay demonstrated high sensitivity and specificity, supporting future clinical validation studies to establish its utility for point-of-care testing (POCT) deployment.
Background: Using a comparative analysis and assessment approach on a number of vaccine under investigation in a specific group is pertinent to local health policy and to our scientific understanding of vaccine responses. Objectives: In this double-blind, cross-sectional study, the efficacy of two platforms inactivated COVID-19 vaccines (CO-Iran Barekat and Sinopharm) and adenoviral-vector COVID-19 vaccines (AstraZeneca and Sputnik V) most commonly used in the Iranian population was evaluated. The target population was 40 - 60 years old. Humoral immune response evaluated by the production of virus-neutralizing antibodies and immunoglobulin G binding to the receptor-binding domain (RBD). Methods: Four hundred twenty volunteers aged 40 - 60 years were vaccinated with the COVID-19 vaccines including CO-Iran Barekat, Sinopharm, AstraZeneca and Sputnik. After receiving the second dose, the humoral immune response was assessed using a conventional neutralizing antibody assay and IgG ELISA. Results: Recipients of the Barekat and Sinopharm vaccines had negative IgG responses of ~15.3% and ~32.97% respectively, while a negative IgG response in the Sputnik V vaccine group showed 10.58%. No negative IgG response was noted with the AstraZeneca group. In the neutralizing antibody assay against SARS-CoV-2, AstraZeneca, Sputnik V, COV-Iran Barekat and Sinopharm showed effective protection in 87.73%, 59.61%, 54.23% and 35.16% respectively. The S1-IgG and SARS-CoV-2 neutralization responses found with Sinopharm and COV-Iran Barekat were similar to those seen vaccinated individuals. In contrast, the conventional live-virus neutralization titer (cVNT50) in SARS-CoV-2-AstraZeneca vaccines was much higher than any of the other three groups. Also data analysis of adverse vaccine event revealed that injection site pain is the most common adverse event in the four groups. Conclusions: The highest levels of neutralizing antibodies were found with AstraZeneca that further support its higher effective potential for protection to SARS-CoV-2. Antibody levels were measured with ELISA IgG Kits and a conventional neutralizing antibody assay technique.
Background: This study aimed to investigate post-coronavirus disease 2019 (COVID-19) distribution patterns of respiratory pathogens using data from a tertiary care center in Erzurum, Turkey. Objectives: This study evaluated the post-pandemic distribution patterns of viral and bacterial respiratory pathogens detected by multiplex real-time polymerase chain reaction and described their associations with age, sex, and seasonal variation in patients with acute respiratory tract infections. Methods: This retrospective study analyzed respiratory samples submitted to Erzurum City Hospital between 2024 and 2025 for suspected acute respiratory tract infection. Pathogens were identified using a multiplex reverse transcription quantitative polymerase chain reaction panel targeting 15 viral and 5 bacterial agents and were analyzed according to age, sex, and season. A P-value < 0.05 was considered statistically significant. Results: A total of 3197 samples were analyzed. The median age was 6 years (interquartile range, 2 - 20 years), and 55.9% of the patients were male. Most samples were collected in winter. Respiratory syncytial virus (RSV) was the most commonly detected viral pathogen, followed by severe acute respiratory syndrome coronavirus 2 and influenza A virus. Streptococcus pneumoniae and Haemophilus influenzae were the predominant bacterial agents. Coinfections were observed mainly in children younger than 10 years, whereas adults more frequently had negative results and lower pathogen diversity. Respiratory syncytial virus, adenovirus, bocavirus, H. influenzae, Bordetella pertussis, and S. pneumoniae were associated with younger age (P < 0.05), whereas coronavirus NL63 was associated with older age (P < 0.001). Seasonal patterns showed that RSV and influenza A virus peaked in winter, influenza B virus peaked in spring, and severe acute respiratory syndrome coronavirus 2 was more prevalent in summer and autumn (P < 0.001). Conclusions: These findings demonstrate the re-emergence of RSV and influenza viruses, whereas severe acute respiratory syndrome coronavirus 2 circulation has shifted to lower levels. Bacterial detection by multiplex polymerase chain reaction requires cautious clinical interpretation. These data may inform diagnostic strategies and rational test use in acute respiratory tract infections.
Background: Adult T-cell leukemia/lymphoma (ATLL) is a human T-cell leukemia virus type 1 (HTLV-i)-associated T-cell malignancy marked by metabolic remodeling and immune escape. Whether the viral transactivator Tax directly engages host transcriptional regulators that connect these processes remains unclear. Objectives: This study tested whether Tax transcriptionally activates high mobility group box 1 (HMGB1) and whether the Tax-HMGB1 axis is associated with glycolytic and immune-evasion phenotypes in ATLL. Methods: Public Gene Expression Omnibus (GEO) cohorts were analyzed within cohort after dataset-specific preprocessing, probe-to-gene collapsing, and standardized signature scoring. Patient-cohort findings were interpreted as associations, whereas mechanistic ordering was examined in a Tax-inducible T-cell model by HMGB1 promoter luciferase assays, chromatin immunoprecipitation quantitative polymerase chain reaction (ChIP-qPCR), small interfering RNA (siRNA) knockdown/rescue, extracellular acidification rate (ECAR), lactate and glucose-uptake assays, flow cytometry, and donor-matched cytotoxic co-culture. Results: In ATLL samples, HMGB1 expression and predefined glycolysis and immune-inhibitory signature scores were higher than in normal CD4+ T-cell controls. Within ATLL, HMGB1 expression was positively associated with both scores and with programmed death-ligand 1 (PD-L1; CD274). Tax induction in a switch model increased HMGB1 expression together with glycolytic and checkpoint-related programs. In mechanistic assays, Tax increased HMGB1 promoter activity and enriched the HMGB1 promoter interval-1163 to-975 in ChIP-qPCR, whereas mutation of a C/EBP-like motif blunted reporter responsiveness. HMGB1 knockdown reduced lactate, ECAR, glucose uptake, PD-IT and Galectin-9 surface expression, and resistance to cytotoxic killing; HMGB1 re-expression partially restored metabolic output. Lactate inhibition and PD-IT blockade each partially rescued cytotoxic killing in donor-matched co-cultures. Conclusions: The experimental data support direct transcriptional activation of HMGB1 by Tax and place HMGB1 upstream of a lactate-associated immune-evasion phenotype in ATLL models. The public patient datasets provide complementary associative support but do not by themselves establish causality or resolve contributions from extracellular HMGB1 and tumor microenvironmental composition.
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: 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: 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-& micro;m 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: 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: Multidrug resistance (MDR) is increasingly being detected in Klebsiella pneumoniae strains. The combined use of antibiotics is one of the important choices in the treatment of these infections. Objectives: This study aimed to evaluate the in vitro activity of the binary combinations of colistin (COL), meropenem (MEM), and ceftazidime/avibactam (CZA) against multidrug-resistant K pneumoniae clinical isolates and to identify carbapenemase genes. Methods: Between January 2022 and November 2023, randomly selected MDR K. pneumoniae isolates (n = 90) isolated from patient samples were included in the study. All isolates were investigated for carbapenem resistance genes using the PCR method. Additionally, the carbapenem inactivation method (CIM) was used as a phenotypic method to investigate carbapenemase production. Antimicrobial interactions (synergy test) were determined using the checkerboard method. Results: The most common carbapenem resistance gene was OXA-48 (72 isolates). The KPC gene was detected in 10 isolates, and the NDM gene in 5 isolates. A synergy test was performed on isolates randomly selected from among those resistant to at least one of the antibiotics COL, CZA, and MEM. Synergistic effect was detected in 50% of the COL-CZA combination, 75% of the MEM-CZA combination, and 45% of the MEM-COL combination. Conclusions: OXA-48 was the most frequently detected carbapenemase gene in MDR K pneumoniae isolates in our region, and KPC and NDM carbapenemase genes were also detected. The high synergy-partial synergy ratios identified in antibiotics may represent a promising treatment option for infections caused by MDR K pneumoniae, but this requires confirmation in studies with larger sample sizes.
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 Acinetobacter 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: Leptospirosis is a zoonotic disease, common in tropical and subtropical regions, caused by pathogenic species of Leptospira. Objectives: This study aimed to isolate and detect Leptospira in animal samples in Amol, northern Iran. Methods: A total of 118 samples were collected from rodent bladder urine and livestock midstream urine during 2023. Culture, microscopy, and molecular analyses were conducted to identify Leptospira interrogans. Cultures were incubated in Ellinghausen McCullough Johnson and Harris (EMJH) media and monitored weekly via dark field microscopy. DNA extraction was followed by conventional and real-time polymerase chain reaction (PCR) targeting the lipL32 gene. Multi locus sequence typing (MLST) was also performed on selected isolates. Results: Results showed that seven (5.93%) samples (including six rodent and one sheep samples) were culture-positive, all confirmed by real-time and traditional PCR. Real-time PCR identified 14 (11.86%) samples as positive for L. interrogans including 9/32 (28.1%), 3/44 (6.81%), and 2/42 (4.76%) rodent, sheep, and cattle samples, respectively. The results of the MLST sequence analysis of four culture-positive specimens were attributable to sequence type (ST) 330 (one sheep specimen) and ST 252 (three rodent specimens), both of which correspond to L. interrogans. Quantitative statistical analyses revealed noteworthy correlations between the types of samples and the presence of Leptospira (P <0.05). Conclusions: This investigation underscores the effectiveness of integrating molecular methodologies with conventional culture techniques for the surveillance of Leptospira in regions characterized by a heightened risk. The current study reports the isolation and characterization of Leptospira from animal urine samples, providing new insights into the presence of these bacteria in the study area.
Background: Shigellosis continues to pose a significant public health challenge worldwide, with recurrent outbreaks and sporadic cases in both developing and developed countries. Molecular genotyping of Shigella isolates is crucial for understanding epidemiology and controlling disease transmission. Objectives: This study aimed to genotype Shigella species isolated from clinical specimens using multiple PCR-based molecular techniques and to evaluate their discriminatory power and efficiency in bacterial strain differentiation. Methods: Sixty Shigella isolates were collected from clinical centers in Tehran and Qazvin, Iran. After biochemical and molecular confirmation, isolates were genotyped using four PCR-based methods: BOX-PCR, ERIC-PCR (Repetitive Intergenic Consensus-PCR), RAPD-PCR, and Rep-PCR. Banding patterns were scored by binary coding (presence/absence), and cluster Results: At a 70% similarity threshold, isolates were grouped into 21, 20, 10, and 17 clusters by BOX-PCR, ERIC-PCR, RAPD-PCR, and Rep-PCR, respectively. Simpson's diversity Index values were highest for ERIC-PCR (0.949) and BOX-PCR (0.92), indicating Conclusions: ERIC-PCR and BOX-PCR demonstrated the highest genotyping performance for clinical Shigella isolates, highlighting their suitability as rapid and reliable tools for molecular epidemiological investigations. These findings support the integration of these PCR-based methods into routine bacterial typing workflows.
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-gamma, TNF-alpha, IL-6, and IL-1 beta mRNA levels. Cytokine secretion was analyzed via ELISA. Results: In BEAS-2B cells, spike protein induced a transient increase in IFN-gamma at early time points, followed by a reduction in IFN-gamma and IL-6 at later times. Conversely, CRL-1831 cells demonstrated sustained or delayed increases in TNF-alpha and IFN-gamma 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.
