Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 5167 5167 Mohammad Mehdi Feizabadi Department of Microbiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran 2024 11 30 2024 11 30 On the occasion of World Antimicrobial Resistance (AMR) Awareness Week, November 2024, we witnessed a lot of events throughout our country, Iran. Many different specialists throughout the country debated on the current situation, however, no one can predict the future outlook of this ongoing issue. The health policy makers try to find the right solutions for combating the drug-resistant superbugs but they should not ignore Microbiology principles. Carbapenem-resistant Klbesiella pneumoniae infections are definitely the main causes of morbidity and mortality in the Iranian Hospitals. In the current issue of this Journal, Dr. Solgi and his colleagues have raised an important and critical point: New Delhi metallo-beta-lactamase (NDM-MBL). Unfortunately, the number of cases infected with ceftazidime/avibactam-resistant Gram-negative bacteria has increased due to NDM-MBL production (Nearly 87% of K. pneumoniae clinical isolates in Isfahan). Therefore, our country resources are wasted with the current official protocol for administration of ceftazidime/avibactam, despite knowing that NDM-MBL producers are dominant. Physicians should be aware of the current situation of MBL strains in Iran, which is attainable through reviewing works published by Microbiologists in different provinces of Iran.   https://ijm.tums.ac.ir/index.php/ijm/article/view/5167 https://ijm.tums.ac.ir/index.php/ijm/article/download/5167/1720

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 720 721 Mojtaba Akbari Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Christian Giske Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet and Karolinska University Hospital, Stockholm, Sweden Hamid Solgi Isfahan Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, Iran; Amin Hospital, Isfahan University of Medical Sciences, Isfahan, Iran 2024 11 28 2024 11 30 No Abstract No Abstract No Abstract https://ijm.tums.ac.ir/index.php/ijm/article/view/5161 https://ijm.tums.ac.ir/index.php/ijm/article/download/5161/1721

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 722 731 Hazhir Moradi Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Zahra Sadat Sajadi-Javan Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Sarah Mousavi Department of Clinical Pharmacy and Pharmacy Practice, School of Pharmacy and Pharmaceutical Sciences, Isfahan University of Medical Sciences, Isfahan, Iran Soodabeh Rostami Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran Bita Moradi Khaniabadi Nosocomial Infection Research Center, Isfahan University of Medical Sciences, Isfahan, Iran 2024 03 29 2024 08 07 Background and Objectives: Nosocomial pneumonia caused by multidrug-resistant gram-negative bacteria presents a significant challenge for healthcare systems, as there are limited effective treatments available. This systematic review and meta-analysis aim to investigate the outcomes of colistin plus meropenem combination therapy on nosocomial pneumonia. Materials and Methods: An exhaustive search of PubMed, Scopus, Web of Science (WOS), and Embase databases was conducted, resulting in the extraction of 5 studies for qualitative assessment and meta-analysis. The study sample included 991 patients admitted with nosocomial pneumonia. The outcomes evaluated were clinical improvement, microbiological response, mortality, Sequential Organ Failure Assessment (SOFA) score, Acute Physiology and Chronic Health Evaluation (APACHE II) score, Charlson Comorbidity Index (CCI), Clinical Pulmonary Infection Score (CPIS), C-reactive protein (CRP) levels, procalcitonin (PCT) levels, and intensive care unit (ICU) duration. Results: The results demonstrated that colistin plus meropenem combination therapy significantly improved clinical outcomes (OR = 1.37, 95% CI = 1.04-1.81, p = 0.027), reduced SOFA scores (OR = -0.28, 95% CI = -0.44 to -0.11, p = 0.001), and increased CCI scores (OR = 0.16, 95% CI = 0.02-0.29, p = 0.021) compared to other medications. However, other evaluated parameters did not show significant differences. Conclusion: This meta-analysis indicates that colistin-meropenem combination therapy is superior to other colistin-based treatments for nosocomial pneumonia in terms of clinical improvement, SOFA score reduction, and CCI score increase. Nevertheless, other variables assessed did not exhibit remarkable differences between the treatment regimens. https://ijm.tums.ac.ir/index.php/ijm/article/view/4673 https://ijm.tums.ac.ir/index.php/ijm/article/download/4673/1722

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 732 736 Uksim Qadri Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Sofiya Zaffar Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Saleem Wani Department of General Medicine, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Shugufta Roohi Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Munazah Aman Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Sabah Bhat Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India Umaya Majid Department of Microbiology, Sher-i-Kashmir Institute of Medical Sciences, Jammu and Kashmir, India 2024 07 05 2024 11 03 Background and Objectives: The incidence of multidrug-resistant, Gram-negative organisms, isolated as the etiological agents of infections is ascending. The advent of novel antibiotics poses significant challenges, necessitating the optimization and utilization of extant antimicrobial agents. Cefoperazone, a third-generation cephalosporin and β-lactam antimicrobial, when combined with sulbactam, an irreversible β-lactamase inhibitor, mitigates the vulnerability of cefoperazone to β-lactamase-producing organisms. Nonetheless, regional data on the susceptibility patterns for this pharmacological combination remains scarce. The primary objective of this investigation was to assess the efficacy of the cefoperazone-sulbactam combination against prevalent Gram-negative bacteria isolated from blood cultures. Materials and Methods: A total of 700 Gram-negative isolates, comprising Escherichia coli, Klebsiella pneumoniae, Acinetobacter species, and Pseudomonas aeruginosa, were procured using the BacT/Alert 3D system. The identification and susceptibility testing for cefoperazone-sulbactam were performed using the VITEK Compact ID and AST system. Comparative analysis was conducted against other tested antibiotics. Results: The study revealed that cefoperazone-sulbactam exhibited commendable in-vitro activity against Gram-negative pathogens isolated from blood, surpassed only by colistin and tigecycline. Conclusion: Cefoperazone-sulbactam demonstrates robust activity against the most frequently encountered clinical pathogens, suggesting its potential as an efficacious therapeutic agent. The findings underscore the imperative for ongoing surveillance of resistance patterns and trends among commonly used antimicrobials. https://ijm.tums.ac.ir/index.php/ijm/article/view/4891 https://ijm.tums.ac.ir/index.php/ijm/article/download/4891/1723

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 737 744 Pegah Shakib Razi Herbal Medicines Research Center, Department of Microbiology, School of Medicine, Lorestan University of Medical Sciences, Khorramabad, Iran Mohsen Arzanlou Department of Microbiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Pouria Sobhi Student Research Committee, Ardabil University of Medical Sciences, Ardabil, Iran Mehdi Mojebi Student Research Committee, Ardabil University of Medical Sciences, Ardabil, Iran Mohammad Bahrami Student Research Committee, Ardabil University of Medical Sciences, Ardabil, Iran Faraz Mahdizadeh Student Research Committee, Ardabil University of Medical Sciences, Ardabil, Iran Leyla Asadi Imam Hospital Laboratory, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Masoud Amanzadeh Department of Health Information Management, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Alireza Mohammadnia Department of Health Information Management, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Farzad Khademi Department of Microbiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran Rashid Ramazanzadeh Department of Microbiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran 2024 08 03 2024 11 15 Background and Objectives: The global problem of urinary tract infections (UTIs) caused by antibiotic-resistant bacteria is due to limited treatment options. This study aimed to examine the prevalence, etiology, and management implications of Escherichi coli causing UTI at Imam Hospital Ardabil, Iran. Materials and Methods: 2340 samples of retrospective data on E. coli causing UTIs were collected at Imam Hospital in Ardabil, Iran, spanning from 2012 to 2022. The samples were cultured and isolated, and their antibiotic susceptibility was determined using standard laboratory methods and data were then organized and systematically categorized using Python. Results: It was found that the lowest level of resistance was related to nitrofurantoin, followed by imipenem. In 2018, the number of E. coli patients resistant to trimethoprim was the highest. Cephalexin and ciprofloxacin trends indicate the reduction of the line during this retrospective period. There was a significant correlation between wards and some antibiotics like Cefepime, Cefotaxime, Ceftazidime, and Trimethoprim (P-Value <0.05). Conclusion: Significant correlations were identified between specific hospital wards and resistance to antibiotics. These findings underscore the need for continuous surveillance and tailored antibiotic stewardship programs to combat the rising trend of antibiotic resistance. https://ijm.tums.ac.ir/index.php/ijm/article/view/4964 https://ijm.tums.ac.ir/index.php/ijm/article/download/4964/1724

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 16 6 2024 12 08 745 754 Golnar Rahimzadeh Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran Shaghayegh Rezai Department of Medical Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Ghazal Abbasi Students Research Committee, Mazandaran University of Medical Sciences, Sari, Iran Saman Soleimanpour Department of Medical Microbiology and Virology, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran Reza Valadan Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran Laleh Vahedi Department of Pathology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran Somayeh Sheidaei Department of Pathology, School of Medicine, Mazandaran University of Medical Sciences, Sari, Iran Faezeh Sadat Movahedi Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran Raha Rezai Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran Mohammad Sadegh Rezai Pediatric Infectious Diseases Research Center, Communicable Diseases Institute, Mazandaran University of Medical Sciences, Sari, Iran 2024 07 06 2024 10 31 Background and Objectives: Klebsiella pneumoniae is a common pathogen associated with healthcare-related infections. It is particularly notable for its ability to develop resistance to multiple antibiotics, making treatment challenging. During the COVID-19 pandemic, increased antibiotic use to manage critically ill patients was contributed to the rise of multidrug-resistant Klebsiella pneumoniae. This study evaluated the antibiotic resistance patterns of multidrug-resistant, ESBL-producing Klebsiella pneumoniae in northern Iran after the COVID-19 pandemic. Materials and Methods: This cross-sectional study was conducted between September 2022 and October 2023. Clinical samples were collected from patients with nosocomial infections at hospitals in Sari. This study included 114 multidrug-resistant ESBLs-producing Klebsiella pneumoniae isolates. Antimicrobial susceptibility was assessed using broth macro-dilution, and resistance genes were detected by multiplex PCR. Results: Gentamicin, ampicillin-sulbactam, co-amoxiclav, and ceftazidime displayed the lowest activity against multidrug-resistant Klebsiella pneumoniae. In contrast, piperacillin-tazobactam showed the highest activity. The prevalence of resistance genes was as follows: blaTEM (99.12%), blaSHV (74.56%), blaCTX (88.60%), blaIMP (64.04%), acrA -B (92.98%), and OqXA -B (67.54%). Conclusion: This study identified over 50% of antibiotic-resistance genes. Over half of multidrug-resistant Klebsiella pneumoniae isolates showed resistance to antibiotics except piperacillin-tazobactam, which is recommended for treating multidrug-resistant Klebsiella pneumoniae infections. https://ijm.tums.ac.ir/index.php/ijm/article/view/4892 https://ijm.tums.ac.ir/index. of dogs and cats, their association with periodontal disease, and the possibility of a common source of infections between humans and companion animals is of great importance for the management of oral health in animals and humans. https://ijm.tums.ac.ir/index.php/ijm/article/view/5330 https://ijm.tums.ac.ir/index.php/ijm/article/download/5330/1817

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 725 733 Aya Maytah Department of Basic Sciences, Ma′an University College, Al-Balqa Applied University, Ma′an, Jordan Omar AlKofahi Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Zarqa University, Zarqa, Jordan Rania Al-Groom Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Zarqa University, Zarqa, Jordan; Department of Allied Medical Sciences, Zarqa University College, Al-Balqa Applied University, Zarqa, Jordan Mohd Sajjad Ahmad Khan Department of Basic Sciences, Imam Abdulrahman Bin Faisal University, Dammam, Saudi Arabia Basem Fouad Dababneh Department of Medical Laboratory Sciences, Faculty of Allied Medical Sciences, Al-Ahliyya Amman University, Amman, Jordan Anas Da'meh Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Zarqa University, Zarqa, Jordan Rahaf Alsarayereh Department of Medical Laboratory Science, Faculty of Allied Medical Sciences, Zarqa University, Zarqa, Jordan Fuad Alhawarat Department of Applied Medical Sciences, Al Hussein Bin Abdullah II Academy for Civil Protection, Al-Balqa Applied University, Salt, Jordan Heba Ahmad Al Shqairat Precision Medical Lab (PMLAB), AL-Karak, Jordan 2025 07 08 2025 08 22 Background and Objectives: Acinetobacter baumannii (A. baumannii) is an opportunistic bacterial pathogen principally related with hospital-acquired infections. This study aimed to isolate and identify A. baumannii strains, investigate their resistance to various antibiotics, and characterize A. baumannii at the molecular level. Materials and Methods: A total of 100 samples were obtained from various hospital departments, including the intensive care unit (ICU), emergency room, kidney dialysis and surgery units. The incidence of drug resistance was studied using the Vitek 2 Compact system and further using molecular techniques such as polymerase chain reaction to analyze the genes responsible for resistance. Results: The study exhibited a high prevalence of multidrug-resistant (MDR) A. baumannii isolates, especially in ICU patients. The males were the predominant group, accounting for 60% whereas females were 40%. The most frequent samples were from urine (43%) and skin (24%). Majority of samples were from the ICU (42%) and emergency departments (20%). The tested isolates exhibited the highest resistance (66%) to oxacillin, whereas the maximum sensitivity (52%) was recorded for Erythromycin. Molecular analysis revealed the occurrence of resistance genes blaOXA-23, blaOXA-24, blaOXA-51, and blaOXA-58, which contribute to carbapenem resistance. Conclusion: The findings emphasize that A. baumannii remains a formidable nosocomial pathogen, and there is pressing requirement for enhanced infection control procedures and antibiotic stewardship. Through improved molecular observation, judicious use of antibiotics and improved infection control practices, healthcare providers can alleviate the impact of MDR A. baumannii infections and improve the prognosis for affected patients in Jordan and beyond. https://ijm.tums.ac.ir/index.php/ijm/article/view/5606 https://ijm.tums.ac.ir/index.php/ijm/article/download/5606/1818

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 734 740 Hayder Ali Department of Biology, College of Science, University of Al-Qadisiyah, Al Diwaniyah, Iraq Dhuha Jabir Department of Biology, College of Science, University of Al-Qadisiyah, Al Diwaniyah, Iraq Zainab Falih Department of Biology, College of Science, University of Al-Qadisiyah, Al Diwaniyah, Iraq Salam Najm Department Diwaniyah Health, Ministry of Health, Al Diwaniyah, Iraq 2025 05 01 2025 07 23 Background and Objectives: Hypermucoviscous Klebsiella pneumoniae exhibits distinct phenotypic and genetic characteristics that distinguish it from the classic K. pneumoniae pathogen. The aim of current study was to investigate some phenotypic and genetic markers used for hmKp identification. Materials and Methods: Seventy-one K. pneumoniae isolates were obtained from the respiratory care unit in Al-Diwanyiah Teaching Hospital \Diwanyah, Iraq, from the first of November 2024 to the first of March 2025. The bacteria were identified, and antibiotic sensitivity testing was performed using VITEK 2 ID-GN and AST cards. Hypermucoviscosity was assessed using the string test, and an investigation into several adherence and virulence genes was conducted for all isolates. Then, multi-locus sequence typing was performed for hypermucoviscous K. pneumoniae isolates. Results: 3 (4.22%) of 71 isolates were hypermucoviscous. The virulence and adherence genes were present in 100% of the isolates, whereas rmpA was only found in hypermucoviscous isolates. The results showed that the hmKp isolates were members of clonal group 147 (CG147) and were assigned to sequence type (ST) 293. Conclusion: The string test is the primary phenotypical diagnosis for hmKp, while the genetically encoded rmpA gene is the most reliable genetic marker for hmKp identification. However, MLST is not beneficial for identification. The central positioning of ST392 within the MST highlights its potential role as an emerging high-risk clone. https://ijm.tums.ac.ir/index.php/ijm/article/view/5474 https://ijm.tums.ac.ir/index.php/ijm/article/download/5474/1819

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 741 750 Muhammad Shafiq Department of Biosciences, Comsats University, Islamabad, Pakistan Amnah Khan Department of Biosciences, Comsats University, Islamabad, Pakistan Muhammad Hyder Department of Biosciences, Comsats University, Islamabad, Pakistan Umme Farwa Department of Pathology, Fazaia Medical College, Air University, Islamabad, Pakistan Farhan Kursheed Department of Microbiology, PMAS Arid Agriculture University, Rawalpindi, Pakistan Sana Khan Department of Pathology, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan Ayesha Siddiqa Department of Pathology, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan Iftikhar Ahmed National Culture Collection of Pakistan (NCCP), Land Resources Research Institute (LRRI), National Agriculture Research Centre, Park Road, Islamabad, Pakistan Muhammad Saeed Department of Biosciences, Comsats University, Islamabad, Pakistan Muhammad Fiaz Department of Pathology, Pakistan Institute of Medical Sciences (PIMS), Islamabad, Pakistan 2024 12 25 2025 07 18 Background and Objectives: Global health is seriously threatened by the rise of carbapenem-resistant Enterobacterales (CRE). The blaNDM gene, a key carbapenemase coding gene, causes global health concern due to its multidrug resistance and easy spread through mobile genetic elements. This study aimed to identify and genetically characterize the blaNDM genes from uropathogens, its antibiotic susceptibility, and its correlation with global sequences. Materials and Methods: Urine samples were processed following microbiological guidelines. Isolates were identified using API-20E. Antibiotic susceptibility was tested using disc diffusion method, and bacterial DNAs were extracted for blaNDM gene sequencing for phylogenetic analysis. Results: CREs were detected in 11.92% (n=51) of the 428 Enterobacterales. Among CRE isolates, 45% (n=23) were positive for blaNDM gene harbored by Klebsiella pneumoniae (57%), followed by Escherichia coli (26%). Uropathogenic CRE, harboring blaNDM, revealed susceptibility of 34.78%, 60.87%, and 65.22% to amikacin, nitrofurantoin, and fosfomycin respectively. The blaNDM-5 variant was most common (69.57%), followed by blaNDM-1 (26.09%) and blaNDM-7 (4.35%). Phylogenetic analysis revealed that blaNDM variants exhibit diverse relationships with Pakistani and worldwide sequences. Conclusion: The significant presence of blaNDM in uropathogens, along with extensive antibiotic resistance, underscores the urgent need for continuous monitoring and antibiotic stewardship programs to manage the growing threat of CRE infections. https://ijm.tums.ac.ir/index.php/ijm/article/view/5216 https://ijm.tums.ac.ir/index.php/ijm/article/download/5216/1820

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 751 760 Amer Mustafa Department of Microbiology, General Directorate of Health Erbil, Ministry of Health, Erbil, Iraq 2025 03 02 2025 09 19 Background and Objectives: Urinary tract infections (UTIs) are common in pregnancy and can cause maternal and fetal complications. Proteus mirabilis is a significant pathogen in recurrent UTIs due to its virulence factors. This study investigated the virulence genes and antibiotic resistance patterns of P. mirabilis isolates from pregnant women with UTIs in Erbil, Iraq. Materials and Methods: This cross-sectional study (September 2024–January 2025) included 120 urine specimens from pregnant women (15-44 years) with UTI symptoms. Bacterial identification was performed using culture, biochemical tests, as well as the Vitek 2 system. Virulence genes were detected by PCR, and antimicrobial susceptibility was assessed by standard methods. Results: Of the 120 samples, 103 (85.8%) showed bacterial growth; 8 (6.7%) were positive for P. mirabilis, while 95 (79.1%) yielded other bacteria. The most affected age group was 25-34 years (52.5%), predominantly in the second trimester (42.5%) and urban residents (60.8%). Antimicrobial resistance was significant to ampicillin, trimethoprim-sulfamethoxazole, amoxicillin/clavulanic acid, and cephalosporins, although susceptibility was observed with several antibiotics. All P. mirabilis isolates harbored the UreC gene, and 75% possessed the MrpA virulence gene. Conclusion: Multidrug-resistant P. mirabilis with key virulence genes was detected in pregnant women with UTIs. Regular screening and resistance monitoring are essential for effective management. https://ijm.tums.ac.ir/index.php/ijm/article/view/5325 https://ijm.tums.ac.ir/index.php/ijm/article/download/5325/1821

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 761 772 Zeb Hussain Department of Microbiology, University of Karachi, Karachi, Pakistan; Department of Clinical Laboratory Sciences, Dow Institute of Medical Technology, Dow University of Health Sciences, Karachi, Pakistan Asma Naim Department of Microbiology, University of Karachi, Karachi, Pakistan Ambreen Fatima Department of Pathology, Dow International Medical College, Dow University of Health Sciences, Karachi, Pakistan Asad Karim Department of Molecular Medicine, Dr. Panjwani Center for Molecular Medicine and Drug Research, International Center for Chemical and Biological Sciences, University of Karachi, Karachi, Pakistan Fakhur Uddin Department of Microbiology, Basic Medical Sciences Institute (BMSI), Jinnah Postgraduate Medical Centre (JPMC), Karachi, Pakistan Surraya Shams Department of Clinical Laboratory Sciences, Dow Institute of Medical Technology, Dow University of Health Sciences, Karachi, Pakistan 2025 05 20 2025 08 25 Background and Objectives: Ventilator-associated pneumonia (VAP) caused by carbapenem-resistant Gram-negative bacteria is a serious ICU challenge. This study determined the prevalence, antimicrobial susceptibility profiles, and phenotypic carbapenemase resistance mechanisms of Gram-negative isolates from VAP patients in two tertiary hospitals in Karachi, Pakistan. Materials and Methods: We included 104 consecutive cases of VAP (July 2021–January 2023). A total of 67 carbapenem-resistant Gram-negative isolates were identified and tested. Antibiotic susceptibility was assessed by disk diffusion and broth micro dilution, according to CLSI and EUCAST guidelines. Modified and enhanced carbapenem inactivation methods (mCIM/eCIM) were used to distinguish metallo-β-lactamase (MBL) and serine carbapenemase production. Results: The mean age was 44.6 ± 18.3 years; 52.2% were male. Early-onset VAP accounted for 37.3% and late-onset for 62.7%. The most frequent pathogens were Acinetobacter baumannii (49.3%, 33/67) and Klebsiella pneumoniae (20.9%, 14/67). Notably, 67% of isolates produced MBLs, and 33% produced serine carbapenemases (phenotypically). The prevalence of multidrug-resistant (MDR), extensively drug-resistant (XDR), and pan drug-resistant (PDR) phenotypes was 42.6%, 31.3%, and 19.4%, respectively. Conclusion: VAP in our ICUs was dominated by A. baumannii and K. pneumoniae with high levels of MBL-mediated resistance. These findings highlight the urgent need for surveillance, stewardship, and new therapeutic options. https://ijm.tums.ac.ir/index.php/ijm/article/view/5505 https://ijm.tums.ac.ir/index.php/ijm/article/download/5505/1822

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 773 782 Azadeh Ehsani Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Neda Soleimani Department of Microbiology and Microbial Biotechnology, Faculty of Life Sciences and Biotechnology, Shahid Beheshti University, Tehran, Iran Mohammadreza Modaresi Estehbanati Department of Pediatric Pulmonary and Sleep Medicine, Children's Medical Center Hospital, Tehran University of Medical Sciences, Tehran, Iran 2024 12 01 2025 08 07 Background and Objectives: Pseudomonas aeruginosa is a Gram-negative bacterium that causes respiratory infections in individuals with cystic fibrosis. Its level of virulence is primarily controlled through Quorum Sensing (QS), a communication mechanism that utilizes small signaling molecules. This study investigates P. aeruginosa antibiotic resistance in CF patients in Imam Khomeini Hospital and examines the presence of QS genes in resistant strains. Materials and Methods: Sixty-five P. aeruginosa samples were identified in CF patients in Imam Khomeini Hospital in Tehran. Antibiotic resistance was assessed using the disk diffusion method, and QS genes (rhlI, rhlR, lasI, lasR) were evaluated by applying PCR. Results: Approximately 61.5 % of P. aeruginosa strains were multiple-drug-resistant (MDR), with 30.7% classified as extensively drug-resistant (XDR). The highest resistance was observed against amoxicillin, amikacin, and cefepime. The most common QS gene in MDR and XDR strains was rhlR. Additionally, 78.9% of XDR isolates carried rhlI, rhlR, lasI, and lasR genes. Conclusion: The study specified that more than half of the P. aeruginosa strains exhibited resistance to five antibiotic classes, and effective antibiotics against P. aeruginosa were colistin, meropenem, ciprofloxacin, piperacillin/tazobactam, and cefotaxime. A noteworthy correlation was identified between MDR and XDR strains and the existence of QS genes in the strains. https://ijm.tums.ac.ir/index.php/ijm/article/view/5169 https://ijm.tums.ac.ir/index.php/ijm/article/download/5169/1823

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 783 790 Farzaneh Zarei Mahmoodabadi Department of Biology, ET.C., Islamic Azad University, Tehran, Iran Akram Tabatabaee Bafroee Department of Biology, ET.C., Islamic Azad University, Tehran, Iran Arfa Moshiri Departments of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Laboratory of Molecular Medicine, IRCCS Instituto Giannina Gaslini, Genova, Italy Seyed Davar Siadat Departments of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran; Department of Biochemistry, Vanderbilt University Class of 2025, Microbiology Research Center (MRC), Pasteur Institute of Iran, Tehran, Iran Nayereh Ebrahimzadeh Departments of Mycobacteriology and Pulmonary Research, Pasteur Institute of Iran, Tehran, Iran 2025 04 28 2025 08 07 Background and Objectives: Breast tissue microbiota differs between healthy and cancerous tissues, with some bacteria influencing tumor progression. Staphylococcus epidermidis, a common skin commensal found in breast tumors, may play a role in epithelial-mesenchymal transition (EMT), a key step in metastasis. This study evaluated the effects of S. epidermidis culture and cell-free supernatant (CFS) on MDA-MB-231 breast cancer cell survival and expression of EMT-related genes Snail1, fibronectin 1 (FN1), and N-cadherin (CDH2). Materials and Methods: Different concentrations of S. epidermidis cultures and their CFS were applied to MDA-MB-231 cells. Cytotoxic effects were assessed by MTT assay at 2, 4, and 24 hours post-treatment. Real-time PCR analyzed gene expression after 24 hours of exposure to non-toxic concentrations (MOI 50 and 100 for cultures; 14% for CFS). Results: Low concentrations did not affect viability, while higher doses (MOI 100 and 14% CFS) reduced viability by up to 60% and 90%, respectively, at 24 hours. MOI 50 did not significantly alter gene expression. At MOI 100, Snail1 and FN1 were significantly upregulated, but CDH2 was unchanged. Treatment with 5% and 7% CFS significantly increased all three EMT gene expressions, indicating EMT induction. Conclusion: S. epidermidis affects EMT gene expression and cell viability, indicating potential involvement in breast cancer progression. https://ijm.tums.ac.ir/index.php/ijm/article/view/5468 https://ijm.tums.ac.ir/index.php/ijm/article/download/5468/1824

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 791 803 Nguyen Vinh Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, University of Health Sciences, Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam; Department of Pharmaceutics, Research Center Of Discovery and Development Of Healthcare Products, Vietnam National University Ho Chi Minh City, Vietnam Nguyen Bac Department of Microbiology and Parasitology, School of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City, Ho Chi Minh City, Vietnam Nguyen Thien Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, University of Health Sciences, Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam Do Minh Department of Science, John F. Kennedy Catholic High School, Washington, U.S.A Dao Trung Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, University of Health Sciences, Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam 2025 07 15 2025 09 14 Background and Objectives: White basil (Ocimum gratissimum L. Lamiaceae) essential oil exhibits potent antibacterial effects but its aqueous insolubility and high volatility restrict its applications. This study aimed to develop a nanodispersed mouthwash containing white basil essential oil, optimizing of surfactant/co-surfactant type and ratio, assess its physicochemical stability and antibacterial efficacy against Streptococcus mutans ATCC 25175. Materials and Methods: Formulations combining white basil essential oil, Tween-80, isopropanol, Labrasol and water were prepared. Particle size, zeta potential, and pH were measured. Stability was evaluated under accelerated (40°C, 75% RH) and stressed (60°C, 75% RH) conditions over three months. Antimicrobial efficacy was assessed via minimum bactericidal concentration (MBC) after 30-second exposure. Results: Characterization of the optimized formulation revealed an average particle size of 128 nm, neutral zeta potential, pH 3.42. Stability testing demonstrated thermodynamic resistance under all storage conditions for three months without phase separation or significant size change. The MBC against Streptococcus mutans was 0.4% w/v essential oil following 30 seconds of exposure. A corresponding mouthwash with 0.4% w/v essential oil demonstrated equivalent bactericidal activity. Conclusion: Nanodispersion offers a promising strategy for white basil essential oil in mouthwash formulations. The developed formulation shows favorable stability and rapid bactericidal action, supporting further evaluation for clinical and commercial development. https://ijm.tums.ac.ir/index.php/ijm/article/view/5628 https://ijm.tums.ac.ir/index.php/ijm/article/download/5628/1825

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 804 813 EN Manizheh Hajizadeh Varzeghan Department of Biology, Science and Research Branch, Islamic Azad University, Tehran, Iran Gholamreza Zarrini Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran Farzam Sheikhzadeh Hesari Department of Animal Biology, Faculty of Natural Sciences, University of Tabriz, Tabriz, Iran Mohammad Hossein Modarressi Department of Medical Genetics, School of Medicine, Tehran University of Medicine Sciences, Tehran, Iran 2024 12 21 2025 07 17 Background and Objectives: Probiotics are effective in improving inflammatory bowel disease (IBD). This study assessed the effect of mesalazine and two candidate probiotics on the improvement of acetic acid (AA)-induced colitis model. Materials and Methods: Lactobacillus plantarum MS1and Lactobacillus delbrueckii YN1 were used for IBD model in rat. Twenty-five male Wistar rats weighing 250 ± 50 grams were used in 5 classified groups: Control (CO); Colitis (CL); Colitis, Probiotic (CLP); Colitis, Mesalazine (CLM); Colitis, Probiotic, Mesalazine (CLPM) and the treatment period was 3 weeks. The rats were treated with mesalazine 30 mg/kg and probiotic 109 CFU/ml after induction of colitis. Histopathological and immunological analyses were performed to evaluate the effects of probiotic bacteria on IBD. Results: The results showed that the probiotic bacteria reduced inflammation (P<0.05), extent (P<0.01), crypt abscesses (P<0.01), edema (P<0.05), inflammatory cell infiltration (P<0.5), and increased mucosa (P<0.001) in rats. Mesalazine administration in animals with colitis did not have a significant effect. Administration of probiotics in both CLP and CLPM groups reduced extent, crypt abscesses, edema, and inflammatory cell infiltration and showed an important role in the down-regulation of consolidation of pro-inflammatory factors (TNFα, IL-6, and IL-17), as well as up-regulation of anti-inflammatory factors such as IL-10. Conclusion: Lactobacillus plantarum MS1 and Lactobacillus delbrueckii YN1 have shown significant potential in alleviating AA-induced colitis symptoms. Their administration leads to a marked reduction in pro-inflammatory cytokines such as TNF-α, IL-17, and IL-6, while enhancing IL-10 levels, indicating their promise as therapeutic candidates for inflammatory bowel disease (IBD). https://ijm.tums.ac.ir/index.php/ijm/article/view/5210 https://ijm.tums.ac.ir/index.php/ijm/article/download/5210/1826

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 814 825 Najmeh Vahed Dehkordi Department of Food Hygiene, Faculty of Veterinary Medicine, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran Ebrahim Rahimi Research Center of Nutrition and Organic Products, Shahrekord Branch, Islamic Azad University, Shahrekord, Iran 2024 05 22 2024 12 11 Background and Objectives: Methicillin-resistant Staphylococcus aureus (MRSA) is a significant cause of illness from consuming contaminated food. MRSA is mainly known for its ability to develop resistance to antibiotics including methicillin. This research examined the antimicrobial resistance pattern, enterotoxigenic dispensation, virulence factors, and biotyping for MRSA isolates. Materials and Methods: Susceptibility of S. aureus isolates to 13 types of antibiotics were assessed, and the genes associated with the resistance were investigated. Disk diffusion was used to identify the phenotypic tenet of antibiotic resistance. PCR is instrumental in detecting genes that confer resistance to antibiotics, virulence and enterotoxin genes. Results: S. aureus were found in 167 out of 363 nugget and salad samples, representing 46% of the total sample count. Seventy-eight isolates (46.71%) were identified as MRSA bacteria. Its prevalence in different sources was as follows: 10% in bovine, 0% in ovine, 30% in poultry, and 56% in humans. MRSA displays high prevalence of resistance to cefotaxime and tetracycline (100%). coa was the most prevalent virulence factor (100%) in MRSA. Conclusion: Distribution of antibiotic resistance genes in MRSA, highlights a serious health issue, as the presence of different antibiotic resistance genes exacerbates multidrug resistance in MRSA isolates. https://ijm.tums.ac.ir/index.php/ijm/article/view/4807 https://ijm.tums.ac.ir/index.php/ijm/article/download/4807/1827

Tehran University of Medical Sciences Iranian Journal of Microbiology 2008-3289 17 5 2025 10 14 826 834 Shahla Shahsavandi Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Sina Soleimani Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Majid Tebyanian Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Amir Ali Hariri Biotechnology Department, Behyaar Sanaat Sepahan Company, Isfahan, Iran Ashraf Mohammadi Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Abbas Zare Mirakabadi Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Mojtaba Noofeli Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran Zarrin Sharifnia Biotechnology Department, Behyaar Sanaat Sepahan Company, Isfahan, Iran Mohammad Mahdi Ranjbar Razi Vaccine and Serum Research Institute, Agricultural Research Education and Extension Organization, Karaj, Iran 2025 02 18 2025 09 06 Background and Objectives: The emergence of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants has presented a challenging issue for global health in the 21st century. Frequent mutations in viral genomes have diminished the effectiveness of current vaccines against new variants. Messenger RNA (mRNA) vaccine is a promising platform for eliciting a robust T cell