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Bacteriophage-based Biocontrol of Escherichia coli O157:H7 in Beef: Investigating Sprayed Wraps for Enhanced Food Safety
Full text linkBackground and Objective: Escherichia coli O157:H7, a major foodborne bacterial pathogen, is commonly detected in the intestines of healthy cattle, deer, goats and sheep. It can readily contaminate veal, ground beef and hamburgers, causing a range of human diseases, including mild diarrhea, hemorrhagic colitis, hemolytic-uremic syndrome and thrombotic thrombocytopenic purpura. Various treatment strategies are used to reduce E. coli O157:H7 contamination, ranging from washing to chemical and physical food decontamination. The increase of antibiotic-resistant bacteria has hence increased interest in lytic bacteriophages as biocontrol agents. This study investigated the use of bacteriophages to control E. coli O157:H7 growth in experimentally contaminated meat.
Material and Methods: Six E. coli O157:H7 specific bacteriophages were isolated from sewage, purified via plaque assay and assessed individually and in cocktails for lytic activity at various multiplicity of infection rates. Temperature-dependent effects on adhesion and lytic efficiency were assessed at refrigeration and ambient conditions. Phages were further used in commercial polyethylene food wraps to assess realistic surface delivery performance on inoculated meat samples and long-term phage stability was monitored during storage at 4 °C.
Results and Conclusion: Single-phage treatments achieved up to 100% bacterial elimination at higher multiplicities of infection, while optimized phage cocktails completely eradicated bacteria. Temperature affected bacterial recovery, with refrigeration decreasing bacterial adhesion and slightly slowing phage-mediated lysis. Importantly, this study has introduced an innovative practical approach using phages onto commonly used commercial polyethylene plastic wraps, demonstrating 99 and 93% reductions when phage‑treated wraps were used after 20 min and 24 h storages, respectively. Long-term storage of phage tf1 at 4 °C for seven months demonstrated stable plaque-forming ability, verifying durability for practical uses. These results highlight bacteriophages as effective, safe and scalable interventions to control E. coli O157:H7 in meat products, providing a practical strategy to enhance food safety, particularly for pathogens with extremely low infectious doses.
Keywords: Bacteriophage biocontrol, Escherichia coli O157:H7, Food safety intervention, Meat contamination, Phage cocktail therapy, Polyethylene wrap application
Introduction
Escherichia coli O157:H7 was identified in 1983 and has since been addressed as a major foodborne bacterial pathogen affecting humans [1, 2]. It is commonly detected in the intestines of healthy cattle, deer, goats and sheep and can therefore readily contaminate veal, ground beef and hamburgers [3]. The E. coli O157:H7 produces Shiga toxins and is classified as an enteric bacterium responsible for diarrhea and dysentery, also known as enterohemorrhagic E. coli (EHEC) [4]. It causes a range of human diseases, including mild diarrhea, hemorrhagic colitis (HC), hemolytic-uremic syndrome (HUS) and thrombotic thrombocytopenic purpura (TTP) [5]. Although other foodborne pathogens such as Listeria, Salmonella enterica Serovar Enteritidis and Shigella species have been isolated from meats, E. coli O157:H7 is particularly concerning due to its extremely low infectious dose, as few as 10 cells, and its ease of transmission during slaughter and meat processing [6]. The microorganism can spread directly from person to person, especially in child day-care settings and from animals to humans [7].
Globally, E. coli infections are estimated to cause 2.8 million cases annually, with approximately 63,000 cases of HC reported each year in the United States alone. Children are particularly susceptible to severe complications such as HUS, a leading cause of acute renal failure (ARF) [8]. Numerous studies have investigated the prevalence of E. coli O157:H7 in food products and the bacterium has been isolated from a variety of plant and animal-derived foods within several countries. Contamination is frequently associated with meat products due to exposure to intestinal contents during slaughter and processing. However, contamination has been reported in raw fruits and vegetables, often linked to the use of untreated animal waste or contaminated irrigation water. Reported prevalence rates vary by country and food type, but the detection of the pathogen in ready-to-eat foods highlights the risk of foodborne illness outbreaks [9]. From 2003 to 2012, 390 outbreaks of Shiga toxin-producing E. coli O157 in the United States led to 4,928 diseases, 1,272 hospitalizations and 33 deaths, with cattle serving as the primary reservoir and ground beef as the most common route of transmission. Undercooked ground beef and other non-intact cuts pose a high risk, making it critical to decrease contamination during beef production, processing and storage and to protect consumers through appropriate handling and cooking of raw beef products [10].
Despite the urgent need to control E. coli O157:H7 contamination, current treatment methods vary in effectiveness and present challenges. To effectively decrease or eradicate E. coli O157:H7 contamination, a variety of treatment methods are currently used, ranging from simple washing of foods to chemical (peroxyacetic acid, chlorine dioxide, sodium hypochlorite and organic acids) or physical (irradiation, pasteurization, high-pressure processing and pulsed electric fields) decontamination techniques. These methods vary in their efficacy, costs and effects on the sensory quality and visual appeal of foods. However, their practical use is limited because several of these treatments can modify texture, flavor and nutritional attributes and some also increase concerns associated to residue safety and toxicity. Furthermore, they are not universally usable within all food types, which limits their feasibility and consistency in real processing environments [11]. Although antibiotics are used as effective chemical agents for removing these bacteria, increasing reports of antibiotic-resistant bacteria suggest that an alternative effective method is needed [12]. The growing threat of multidrug-resistant bacterial pathogens necessitates urgent investigation of alternatives to traditional antibiotics [13].
Regarding the limitations of current treatments, bacteriophage therapy, first developed by Felix d’Herelle and historically overshadowed by antibiotics, has re-emerged as a promising alternative to traditional antibiotics. This is due to its specificity, ability to target biofilms, minimal side effects and potentials to decrease antibiotic resistance development [14]. In food safety, bacteriophages offer unique advantages because of their narrow host range, which enables them to eliminate pathogenic E. coli strains without harming beneficial microbiota [15]. Coliphages, in particular, are abundant in environments such as sewages, animal wastes and water sources, making them accessible for isolation and use against foodborne pathogens [16]. One challenge to their use is the possible emergence of phage-resistant bacteria; however, this can be addressed through the use of phage cocktails composed of multiple phages with complementary host specificities. Such formulations not only broaden the range of susceptible bacterial targets but also decrease the likelihood of resistance development. Moreover, phages include the ability to evolve in bacteria, allowing them to overcome resistance mechanisms that limit the effectiveness of antibiotics. These characteristics have provided a way for regulatory acceptance of several phage-based products in the food industry, particularly for the control of E. coli O157:H7 in beef and fresh products, highlighting their potential as sustainable and innovative tools to enhance food safety [17].
Bacteriophages have been recognized as safe for use in food production and are classified as generally recognized as safe (GRAS) by the U.S. Food and Drug Administration (FDA). While phages targeting E. coli O157:H7 such as EcoShield and SecureShield E1 have received GRAS approval for use in beef and other food products, similar approvals exist for phages against other foodborne pathogens. The GRAS phages are valued for their specificity, safety for human consumption, minimal effects on the food sensory characteristics and ability to decrease pathogen levels without contributing to antimicrobial resistance [18]. This research investigated the use of bacteriophages as biocontrol agents to control the propagation of artificially contaminated E. coli O157:H7 in meat samples.
Materials and Methods
2.1. Bacteria cultivation
Lyophilized E. coli O157:H7 PTCC 1860 was provided by the Persian Type Culture Collection (PTCC), Iran. The strain was cultured on tryptic soy agar plates at 37 °C for 16–18 h. For storage, bacterial cultures were suspended in tryptic soy broth (TSB) with 15% glycerol and stored at -80 °C. Bacterial counts were determined as colony-forming units (CFU) defined as viable bacterial cell capable of forming a visible colony on solid media.
2.2. Isolation and purification of bacteriophages
Bacteriophages were isolated from environmental water, sewage and slaughterhouse sewage samples. Briefly, 100 mL of sewage samples were collected in sterile bottles and transported to the laboratory. To enrich bacteriophages, samples were mixed with 200 mL of TSB media and inoculated with the E. coli host and then incubated overnight at 37 °C. Chloroform was added to the mixture for 10 min to lyse the bacterial cells, followed by centrifugation to remove debris. The resulting supernatants, containing potential bacteriophages, were assessed against host bacteria using double-layer agar method [19]. After overnight incubation at 37 °C, plates were investigated for plaques. Single plaques were isolated and subjected to repeated culture using double-layer agar technique to purify individual bacteriophages. Isolated bacteriophages were stored in SM buffer at 4 °C. Phage titers were expressed as plaque-forming units (PFU), where one PFU corresponded to an infectious phage particle that produced a visible plaque on a bacterial lawn.
2.3. Contaminated-meat experiments
Fresh beef was purchased from a local butchery and cut into similar pieces. Their sterility was assessed before use. For experimental contamination, E. coli O157:H7 was cultured overnight and a bacterial suspension was prepared at a concentration of 10⁷ CFU.mL-1. Meat samples were immersed in the suspension and agitated for 10 min to allow bacterial adhesion. The multiplicity of infection (MOI) was reported as the ratio of phage particles (PFU) to bacterial cells (CFU).
2.3.1. Single Phage Treatment
Meat samples were divided into three groups and suspended in sterile water, including untreated meat (control), meat treated with E. coli O157:H7 at 10⁷ CFU.mL-1 (bacteria only), meat contaminated with E. coli O157:H7 (10⁷ CFU.mL-1) and subsequently treated with a specific bacteriophage at 10⁸ PFU.mL-1 (phage-treated). All samples were agitated for 20 min; after which, aliquots were serially diluted (10-¹, 10-² and 10-³) for plating on eosin methylene blue (EMB) agar. Sampling and culturing were repeated after 60 min to assess bacterial decrease over time. The entire procedure was carried out at room temperature (RT) and 4 °C to assess the effect of temperature on phage efficacy.
2.3.2. Phage Cocktail Treatment
A mixture of three bacteriophages (TF1, TF2 and SC) was used in meat samples inoculated with E. coli O157:H7 (10⁷ CFU.mL-1) at a total phage concentration of 10⁸ PFU.mL-1. To further assess the cocktail performance, an additional trial was carried out; in which, each phage was used individually at 10⁸ PFU.mL-1.
2.4. Contaminated ground beef experiments
Ground beef was prepared from the meat under sterile laboratory conditions and divided into three portions of equal weight. One portion was untreated as a control. The second portion was inoculated with E. coli O157:H7 at a concentration of 5 × 10⁸ CFU.mL-1 without further treatment. The third portion was similarly contaminated with the bacteria, agitated for 20 min to ensure homogenized distribution and then treated with a bacteriophage suspension at 10⁸ PFU.mL-1. These experiments were carried out at RT and 4 °C.
2.5. Plastic wrap treatment with bacteriophages
Beef samples were covered with plastic wrap under various conditions. The wrap included commercial food-grade low-density polyethylene available in the market. In the control setup, uncontaminated beef was wrapped with untreated plastic. A second setup involved contaminated beef wrapped with plastic that did not contain bacteriophages. In the phage-treatment setup, plastic wrap was pretreated with a suspension containing 10⁹ PFU.mL-1 bacteriophages by spraying and storing at 4 °C for 20 min and then used in contaminated beef for 30 min at 4 °C. To further assess the protective effect of wraps over time, additional plastic sheets were incubated at 4 °C for 24 h after sprayed with the phage suspension followed by covering beef samples for 30 min.
2.6. Statistical analysis
All experiments were carried out in three replicates (n = 3). Quantitative data were presented as mean ± SD (standard deviation). Error bars in figures represented SD of the replicates.
Results and Discussion
Four bacteriophages were isolated from municipal sewage and two others from slaughterhouse wastewater. These were designated as tf1-tf4 and sc-sg, respectively. Of the six bacteriophages isolated, tf1 was chosen for further individual assessments based on its distinct plaque morphology. This produced large, clear and well-defined plaques, suggesting high lytic efficiency and strong bactericidal potential against E. coli O157:H7. In contaminated beef experiments, when 106 PFU.mL-1 of tf1 bacteriophage was used at RT against 107 CFU.mL-1 of E. coli O157:H7, 65% ±0.5 of bacteria were removed after 20 min (MOI = 0.1) at RT. Increasing phage dose up to 109 PFU.mL-1 led to 99% ±0.4 bacterial elimination (MOI = 100), as shown in Figure 1.
Exposure with phage for 60 min at RT, addition of 107 PFU.mL-1 of phage to 106 CFU.mL-1 of bacteria resulted in nearly 93.5% ±0.4 elimination (MOI = 10). However, bacteria were more effectively removed, when treated by 108 PFU.mL-1 phage even up to 99% ±0.2 (MOI = 100). Elimination rate was 100%, when 109 PFU.mL-1 of phage was added to 107 CFU.mL-1 of bacteria (MOI = 1000), as shown in Figure 2. Bacterial decreases are shown at the second y axis (right y axis).
For assessing the effect of phage cocktail, including tf1, tf2 and sc, cocktails with two various formulas were assessed. Meat containing 107 CFU.mL-1 bacteria was exposed to a dose of 108 PFU.mL-1 cocktail phages and showed nearly 99% ±0.1 of bacteria being lysed after 20 min and 99.5% ±0.1 after 60 min. When a cocktail included 108 PFU.mL-1 separately, bacterial removal was 100%; as shown in Figure 3. Comparison of performance between single-phage (Figure 1-2) and cocktail treatments (Figure 3) indicated that while tf1 alone achieved strong bacterial decrease at higher MOIs, the cocktails demonstrated enhanced efficacy and reliability in reaching levels below infectious (< 100 CFU) and ingestion (< 10 CFU) thresholds. The optimized cocktail not only maintained 99% bacterial elimination but achieved complete eradication when used at equivalent individual phage titers, demonstrating superior robustness in ensuring bacterial counts fall below clinically relevant exposure limits.
In ground beef experiments, meat samples were inoculated with E. coli O157:H7 at an initial concentration of 107 CFU.mL-1 and then treated with 108 PFU.mL-1 of bacteriophages for either 20 or 60 min at 25 and 4 °C. Bacterial recovery from the meat was affected by temperature, as adhesion decreased at refrigeration temperature, compared to ambient conditions, consistent with the lower metabolic activity and decreased surface interactions of bacteria at colder environments. After 20 min of phage exposure, bacterial counts decreased by 96.4% ±0.1 at 25 °C and 82.0% ±0.4 at 4 °C (Figure 4). When exposure time was extended to 60 min, decrease rates increased to 99.95% ±0.05 and 87.0% ±0.5 at 25 and 4 °C, respectively, indicating that phage-host interactions were kinetically dependent, with higher temperatures favoring further efficient adsorption and subsequent lysis. These findings suggested that rapid refrigeration of meat could decrease infection risk by limiting bacterial attachment, even though phage-mediated lysis occurred further slowly at lower temperatures
Contaminated meat samples were covered for 30 min with plastic wraps coated with 109 PFU.mL-1 phage for 20 min and 24 h. significant viable cell decreases, at the two conditions were observed with the greatest decrease in the 20 min-treated plastic wrap, compared to controls without phages. This included 99.0% ±0.9, compared to 93% ±2 in 24 h-treated group; as shown in Figure 5.
To assess the long-term stability of phage tf1, its plaque-forming ability was assessed over a 7 m storage at 4 °C. At a 10⁻⁷ dilution, plaque counts were consistent within all measured time points, showing no appreciable decreases in infectivity (Figure 6). The average plaque count calculated from all sampling intervals was stable, further verifying the persistence of active phage particles during prolonged storage. Minor deviations observed between the months were included within the expected range of experimental variability, which might be seen due to the counting precision or inherent assay fluctuations. Overall, these results indicated that phage tf1 preserved its infective capacity and structural integrity for at least 7 m under refrigerated conditions, highlighting its strong potential for use in long-term biocontrol uses.
The EHEC are pathogenic E. coli strains that produce Shiga toxins and cause HC and its life-threatening sequelae of HUS [20]. Since identification of serotype O157:H7 in 1983, many outbreaks associated with EHEC have been reported in the United States and E. coli O157:H7 has become one of the most important foodborne pathogens [21]. It causes severe human disease worldwide. It seems important to eliminate this pathogen in appropriate way [5]. Antibiotics were always an option; however, with increasing antibiotic-resistant strains due to use of antibiotics in cow feed, an alternative treatment is needed [22].
In a study, the overall prevalence of Shiga toxin-producing E. coli in raw beef samples collected from an industrial slaughterhouse in Hamadan, Iran, was 10.4%, with one isolate (12.5%) belonged to the O157 serogroup and the rest isolates of 87.5% classified as non-O157. The prevalence of O157 (1.3%) was similar to that reported in Iran (e.g., 1.35% in Mashhad), greater than those reported from the EU (0.3%), the U.S. (0.8%) and Brazil (1%) and less than those reported in Nigeria (2.2%) and Australia (1.7%). The study verified cattle as a reservoir for Shiga toxin-producing E. coli and highlighted seasonal and animal-associated factors such as spring sampling and the use of feeder cattle, which might contribute to the prevalence [23]. Additionally, they reported that 5.3% of raw poultry meat samples were contaminated with E. coli O157 strains. Out of 257 samples, 36% of the samples contained E. coli isolates, with 38.7% of the isolates identified as Shiga toxin-producing E. coli carrying virulence genes such as stx1, stx2 and eae. The isolates showed significant genetic diversity and high resistance to antibiotics, including nalidixic acid, tetracycline, ampicillin and trimethoprim-sulfamethoxazole [24].
Since discovery of bacteriophages, they included therapeutic potential as natural enemies of bacteria and phase-based elimination of bacteria in agriculture and food industry was started [25]. Therefore, bacteriophages have been reported as good antibiotic alternatives. They provide a highly specific, environmental-friendly effective means of controlling bacterial pathogens in agriculture; thereby, contributing to efforts against the increase of antibiotic resistance in the food sector [26].
This study aimed isolation of effective bacteriophages for biocontrol of E. coli O157:H7 in beef and ground beef. Six phages were isolated and assessed in suspension and spray methods on beef and beef ground samples at RT and 4 °C. The use of the submersion method to assess bacterial attachment to meat showed less bacterial recovery at 4 °C, compared to 25 °C, verifying that adhesion and phage inactivation efficiency were modulated by temperature, likely due to differences in bacterial physiology and phage adsorption kinetics. These findings highlighted the importance of environmental conditions and exposure time in optimizing phage-based biocontrol strategies in meat systems. Furthermore, the effect of various MOIs were assessed after incubation times of 20 and 60 min. The results showed that the phage treatment eliminated 82 to 100% of E. coli O157:H7. Phage cocktails included a better elimination rate. In a similar study, a cocktail of all three phages was assessed for their ability to lyse the bacterium in vivo and in vitro. The phage cocktail totally eradicated E. coli O157:H7 from beef surfaces in seven out of nine experiments. They have isolated phages from bovine farmyard slurry samples. The study achieved superior results when using phage cocktails similar to those used in this study, suggesting that a combination of multiple phages could enhance the effectiveness against the target bacteria. Another bacteriophage cocktail of three lytic phages for E. coli O157:H7 was investigated for its ability to decrease experimental cont
بررسی انتقادی محتوای برنامه و خدمات عرصۀ سلامت روان در نظام مراقبتهای اولیۀ بهداشتی با روش واسازی و تحلیل انتقادی
No full textخلفية البحث وأهدافه: تعتبر السلامة النفسیة جزءاً لا یتجزأ من السلامة والرفاه الفردي والإجتماعي. إنّ وتیرة انتشار الأمراض في العالم توحي بأنّ المشاکل والتحدیات المتعلقة بالسلامة النفسیة تعتبر العامل الثاني في انتشار الأمراض والعجز الصحي. اما بالنسبة للبلاد (إیران) یمکن القول أنّ البلاد خطت خطوات جبارة في نظام العنایة الصحیة علی مستوی البلاد ونجحت في تعمیم القطاع الصحي والضمان الإجتماعي والسلامة النفسیة. والشعب یثق بشکل کبیر في النظام الصحي ویتعامل مع برامج ومشاریع نظام الصحة النفسیة. کما أنّ هناك الکثیر من الخدمات التي یقدمها النظام الصحي لعدد هائل من المواطنین. ولهذا تسعی هذه الدراسة لتقییم دقیق للخدمات والبرامج الخدمیة التي یقدمها النظام الصحي في البلاد.
منهجية البحث: المنهج الذي اعتمدت علیه الدراسة هو المنهج التفکیکي مع الترکیز علی فهم المحتوی بدل الوصف ونقد هذه البرامج نظریاً وبنیویاً. ولکي تنجح الدراسة في البحث بادر الباحثون بجمع المحتوی النصي لقسم السلامة النفسیة في مکاتب السلامة النفسیة، والإجتماعیة، ومراکز إعادة تأهیل المدمنین الموثوقة لدی وزارة الصحة؛ وقد تضمنت 1210 صفحة تم استخراج وتجمیع المفاهیم الأساسیة منها. وفي المرحلة الأخیرة قام الباحثون باستخراج المفاهیم الأکثر أهمیة لدراستها وتحلیلها بشکل جذري بغیة استخراج النتیجة الأکثر دقةً. إنّ مولفي البحث لم یشیروا إلی أيّ تضارب في المصالح.
المعطیات: اکدت النتائج التي حصل علیها الباحثون أنّ هناك مواطن ضعف في نظام الصحة مثل غیاب التناسق الثقافي بین المحتوی وثقافة الأفراد، وعدم الإهتمام بالصحة الروحیة، وقِدَم المضامین وغیاب الإرجاع إلی المصادر المعتبرة.
الاستنتاج: نظراً لتوفّر مصادر علمیة ونماذج محلیة ناجحة، یجب إعادة النظر في برامج النظام بهدف الإرتقاء بمستوی الخدمات الصحیة والسلامة النفسیة في المجتمع والتأکید علی الوقایة وتوقي الأمراض بدل علاجها.Background and Objective: Mental health is considered an inseparable part of individual and social health and well-being. The prevalence of diseases in the world shows that mental health problems are the second most debilitating factor in health. The primary health care system in the country has a very successful history in generalizing and developing mental health services. People are easily connected to this system and cooperate and participate to a large extent for the implementation of mental health programs. A large number of service packages are implemented in the country. For this reason, it is necessary to carry out a detailed review and evaluation of the content of services and care packages.
Methods: In this article, the deconstruction method was used with an emphasis on the deep understanding of the contents instead of describing them and their theoretical and fundamental criticism. For this purpose, all the textual content of the Mental Health Department of the Mental and Social Health and Addiction officeof the Ministry of Health, which include 1210 pages, was analyzed and the main concepts were compiled and summarized. Finally, the extracted fundamental concepts were discussed and conclusions were drawn. The authors of the article have reported no conflicts of interest.
Results: Low level of cultural compatibility, neglect of spiritual health, outdated materials and lack of references to reliable sources were identified and confirmed.
Conclusion: It is essential to conduct a fundamental review based on scientific resources and indigenous models, aiming to enhance the mental health of the community with a preventive approach in the packages.سابقه و هدف: سلامت روان بخشی تفکیکناپذیر از سلامت و رفاه فردی و اجتماعی قلمداد میشود. روند شیوع بیماریها در جهان نشان میدهد که مشکلات سلامت روان دومین عامل ناتوانکنندۀ سلامتی است. نظام مراقبتهای اولیۀ بهداشتی در سطح کشور پیشینۀ بسیار موفقی در تعمیم و توسعۀ خدمات سلامت روان دارد. مردم به شبکۀ بهداشت اعتماد دارند و بهراحتی به این نظام پیوند میخورند و تا حد زیادی برای اجرای برنامههای بهداشت روان همکاری و مشارکت میکنند. بستههای خدمت به تعداد بسیار زیاد در کشور اجرا میشود. به همین دلیل این پژوهش با هدف نقد و ارزیابی دقیق از محتوای بستههای خدمت و مراقبت صورت گرفته است.
روش کار: در این مقاله از روش واسازی با تأکید بر درک ریشهای و عمیق محتواها بهجای توصیف آنها و نقد نظری و بنیادی آنها بهطور جسورانه استفاده شده است. بدین منظور تمام محتوای متنی گروه سلامت روان دفتر سلامت روان، اجتماعی و اعتیاد وزارت بهداشت که مشتمل بر 1210 صفحه بود بررسی شد و مفاهیم اصلی تدوین و جمعبندی شد. در مرحلۀ آخر نیز مفاهیم بنیادین استخراجشده به بحث گذاشته شد و نتیجهگیری انجام پذیرفت. مؤلفان مقاله هیچگونه تضاد منافعی گزارش نکردهاند.
یافتهها: بر اساس نتایج بهدستآمده، تطابق پایین فرهنگی، بیتوجهی به سلامت معنوی، قدیمیبودن مطالب و نبود ارجاع به منابع معتبر محرز گردید.
نتیجهگیری: ضروری است بر اساس منابع علمی و الگوهای بومی، بازبینی اساسی با هدف ارتقای سلامت روان جامعه با رویکرد پیشگیرانه در بستهها انجام گیرد
The Effectiveness of Reality Therapy on Anger Rumination, Depression, and Quality of Life among Individuals Bereaved Due to COVID-19
Full text linkBackground and Aim: This study aimed to investigate the effectiveness of reality therapy on anger rumination, depression, and quality of life among individuals bereaved due to COVID-19.
Materials and Methods: The research method was a quasi-experimental design with pre-test, post-test, and follow-up phases, including a control group. The statistical population comprised all first-degree survivors of COVID-19 victims in Nishapur city. A total of 30 participants were selected through purposive sampling and were then randomly assigned to two groups of 15: experimental and control. The experimental group underwent an intervention of reality therapy over 8 sessions, each lasting 1.5 hours, while the control group received no intervention. Data were collected using the Anger Rumination Scale (ARS), the World Health Organization Quality of Life Questionnaire (WHOQOL-BREF), and the Beck Depression Inventory (BDI-II). The data were analyzed using multivariate covariance analysis (MANCOVA) via SPSS24 software.
Results: The results of Bonferroni post-hoc tests comparing time effects indicated that the differences in the mean scores of qualities of life, anger rumination, and depression between the pre-test and post-test phases, as well as between the pre-test and follow-up phases, were statistically significant. However, the differences in mean scores between the post-test and follow-up phases were not significant (P > 0.05).
Conclusion: Accordingly, reality therapy was effective in improving anger rumination, depression, and quality of life among survivors of COVID-19 victims, and this effectiveness persisted during the follow-up period. Psychologists and counselors can use reality therapy to enhance anger rumination, depression, and quality of life among individuals bereaved due to the COVID-19 pandemic
High Succinate peak in Magnetic Resonance Spectroscopy: A Diagnostic Clue for the Leukoencephalopathy Result from Succinate Dehydrogenase Deficiencies: Leukoencephalopathy result from SDH deficiencies
No full textThe Succinate Dehydrogenase (SDH) enzyme is known as Complex-II in the electron transport chain. This study reports the clinical and molecular investigations of three pediatric patients (two of whom are siblings), with histochemical and biochemical evidence of a severe, isolated complex II deficiency due to SDH gene mutations. The patients presented with severe hypotonia, developmental delay, spasticity, macrocephaly, and megalencephaly. Magnetic Resonance Imaging (MRI) revealed signal changes in the frontal, temporal, parietal, occipital cerebral, and cerebellar white matter, corpus striatum, thalamus, substantia nigra, inferior olivary nucleus, pyramidal tracts at the level of the pons and posterior limb of the internal capsule. Other typical findings involved a high succinate peak at 2.42 ppm and lactate peak at 1.3 ppm in Magnetic Resonance Spectroscopy (MRS). The siblings presented due to compound heterozygous c.143A>T (p. Asp48Val) and c.308T>C (p. Met103Thr) SDHB mutations, while the other patient presented due to compound heterozygous c.1754G>A (p. Arg585Gln) and c.1786G>C (p. Asp596His) SDHA mutation. The demonstration of succinate peak, particularly MRS, is highly diagnostic regarding SDH deficiency. MRS should be a standard part of routine radiological exams when there is a suspicion of a neurometabolic disease, especially mitochondrial disorders. Additionally, employing Next-Generation Sequencing (NGS) is advisable for patients as it allows for accurate diagnosis without requiring invasive procedures like muscle biopsie
A Comprehensive Methodological Review of Major Developments in Bioinformatics Pipelines for Transcriptomic Data Analysis
Full text linkBackground: Recent advances in transcriptomics have provided new insights to analyze a wide range of biological data. RNA sequencing (RNA-Seq) is a common method used to study the complete set of RNA molecules (the transcriptome) in different cell types, genetic backgrounds, and environments. While many computational tools exist for analyzing large RNA-Seq datasets, there is still a need to thoroughly compare methods used to separate mixed cell populations (deconvolution).
Materials and Methods: This review highlights recent software and database improvements for processing RNA-Seq data, including steps like matching sequences to the genome, reconstructing RNA molecules, and measuring RNA abundance.
Results: We examine how well different methods work under various experimental conditions and discuss important factors such as data quality, sequence alignment, data visualization, identifying gene expression differences, and data standardization. A novel approach is also introduced: an ensemble learning-based deconvolution method combining multiple techniques to improve accuracy, mitigate data contamination, and reduce errors. Our findings provide valuable guidance for using omics tools effectively and developing better analysis methods. This review offers detailed instructions for planning and evaluating Illumina sequencing experiments.
Conclusion: We cover basic concepts, RNA-Seq analysis steps, computational workflows, and potential difficulties
Relationship Between Corpus Callusom Index and Clinical Subtypes, Severity of Cognitive Disorders, and Disability in Multiple Sclerosis
Full text linkBackground: Brain magnetic resonance imaging (MRI) is crucial to determine the prognosis of multiple sclerosis (MS). The use of simple and accessible techniques that can be used for examining and managing the cognitive status and disability of patients with MS is one of the important concerns. This study aimed to investigate the relationship between corpus callosum index in brain MRI and clinical subgroups of MS, severity of cognitive disorders, and disability in multiple sclerosis.
Materials and Methods: This cross-sectional study was conducted to determine the relationship between CCI and clinical subgroups of MS, the severity of cognitive disorders, and disability in patients with MS referred to Imam Hossein Hospital in 2020. The maximum length of the corpus callosum (anterior, posterior diameter) was measured, and the height of the corpus callosum was measured on a line perpendicular to its long axis. Corpus callosum index (CCI), symbol digit modalities test (SDMT), and expanded disability status scale (EDSS) were assessed in patients. A significance level of less than 0.05 was considered.
Results: A total of 85 patients with a mean age of 40.73 ± 8.45 years were assessed, and 65.9% were women. The CCI value was significantly lower in women (P-value: 0.001). The mean value of EDSS in all participants was 2.64±2.49. There was a statistically significant difference between the different subgroups of MS with the EDSS score, age of disease onset, SDMT score, CCI index, and mean disease duration (all P-values<0.05). There was a significant negative correlation between the CCI index and age (P:0.02, r:-0.24), duration of the disease (P:0.001, r:-0.38), EDSS (P:0.001, r:-0.71), while the correlation between SDMT and CCI was positive (P:0.001, r:0.67).
Conclusion: CCI is a quick and cost-beneficial parameter to evaluate cognitive disorders and disability in patients with MS
Subcutaneous Infection Resulting From the Migration of a Peripherally Inserted Central Catheter Into the Angular Vein
Full text linkBackground: Peripherally inserted central catheter (PICC) migration into smaller veins is rare, often recognized only when catheter dysfunction occurs or associated clinical complications manifest. This study aims to highlight subcutaneous tissue infections as an unusual complication of PICC migration in newborns.Case Presentation: We report a case of a newborn male who experienced PICC migration into the angular vein after a prior successful repositioning. Factors contributing to this migration include anatomical variations in the venous system, left-sided catheter insertion, the need for mechanical ventilation due to persistent pulmonary hypertension of the newborn, and the potential influence of using a 2 Fr diameter PICC line.Conclusion: Maintaining detailed documentation of the external catheter length and conducting regular imaging post-PICC placement is crucial, especially if the patient shows signs of catheter dysfunction or if unanticipated complications develop
Effects of GLUMA Desensitizer and Low-Level 980 nm Diode Laser on the Retention of the Metal Frames of the PFM Crowns Cemented by Self-adhesive Resin Cement (RelyX U200): Effects of GLUMA and 980nm diode laser on the retention of metal frameworks
No full textIntroduction: Sometimes, dentinal tubules are exposed to the oral cavity during the preparation of vital teeth for crowns, and patients show various signs of tooth hypersensitivity. Some treatments have been suggested for dental hypersensitivity after tooth preparation, such as low-level diode laser (980 nm) and GLUMA desensitizer. The pretreatment of dentin with desensitizers may affect retention. The aim of this study was to ascertain the effects of the 980nm Diode laser and GLUMA Desensitizer on the retention of the metal frames cemented by self-adhesive resin cement (RelyX U200).Methods: Thirty intact permanent maxillary first premolars were used in this study. After preparing teeth with 0.5 to 0.7 finishing line above CEJ, casting full metal crowns with a 5-diameter ring on the occlusal surface was done. Then the samples were divided into 3 groups: (1) Control Group (n=10), (2) 980 nm diode laser (n=10), and (3) GLUMA desensitizer (n=10). Frames were cemented with self-adhesive resin cement (RelyX U200) and the bond strength was measured by a universal testing machine. Data were analyzed by ANOVA and Tukey post hoc tests in SPSS version 25 (P<0.05).Results: Frame retention in the 980 nm diode laser group (40.90±27.07N) was significantly lower than the control group (138.17±40.81 N) and the GLUMA desensitizer group (318.59±56.31N) (P<0.05), and frame retention in the GLUMA Desensitizer group was significantly higher than the other groups (P<0.05).Conclusion: The GLUMA desensitizer has a positive effect and the 980 nm diode laser has a negative effect on the retention of frames cemented by self-adhesive resin cement (RelyX U200)
Comparing the Frequency of Migraine Headaches in Children With and Without Enuresis: Migraine Headache in Enuresis
No full textBackground and Aim: Nocturnal enuresis and migraine are common disorders amongchildren, each having a major impact on the health and life status of the children andtheir families. In several children, these two disorders have also been observed together.Accordingly, this study evaluates the relationship between migraine and nocturnal enuresisby examining the frequency of migraine in children with nocturnal enuresis.Methods: In this analytical cross-sectional study, the experimental group includes childrenwith nocturnal enuresis, who were diagnosed by a pediatric nephrologist. The controlgroup is comprised of children without nocturnal enuresis. In both groups, the frequencyof migraine headaches diagnosed by pediatric neurologists was checked and finally, thefrequency obtained in the two groups was compared. The sample size was 47 people foreach group. Information analysis was done through analytical statistics, including tables andstatistical charts and their analysis. Independent t-test, the chi-square test, the Fisher test, andif necessary, equations were used to analyze the non-parametric data.Results: The distribution of frequency between gender and nocturnal enuresis was the samein two groups (57.4% male and 42.6% female). Also, the mean age in the patient categorywas 7.6±2.3 years and in the healthy category was 8.3±2.6 years. The frequency distributionbetween having migraine, migraine with aura, the number of times experiencing headache,and family history at the time of admission were the same in the two groups.Conclusion: In conclusion the frequency of migraine, migraine with aura, the number oftimes experiencing headache, and family history of migraine were the same in the two group