Prevalence and antimicrobial susceptibility of Salmonella enteritidis and Salmonella typhimurium isolated from hen eggs and quail eggs in Karaj, Iran.

BACKGROUND AND AIM: Different Salmonella serotypes are considered one of the most important food pathogens in the world. Poultry meat and eggs are the primary carriers of Salmonella in human populations. This study aimed to estimate the Salmonella enteritidis and Salmonella typhimurium contamination rates of retail hen and quail eggs in Karaj, Iran. Moreover, the antimicrobial resistance patterns of the strains were evaluated, and the efficiency of the standard culture method and multiplex polymerase chain reaction (m-PCR) were compared. MATERIALS AND METHODS: In this descriptive cross-sectional study over 1 year (Jan-Dec 2022), 150 commercial and 150 backyard hen eggs and 300 commercial quail eggs, without cracks and fractures, were collected randomly from best selling groceries in Karaj city. All samples were examined for Salmonella contamination independently by standard culture and m-PCR approaches. A standard disc diffusion method was employed to assess the antimicrobial susceptibility of the strains against 18 antimicrobial agents. RESULTS: Out of 300 examined eggs, 2 S. enteritidis strains were isolated from the shell of backyard hen eggs. The same serotype was also detected in the contents of one of these two eggs. One S. typhimurium was isolated from the shell of a commercial hen egg. Overall, the Salmonella contamination of the shell and contents was 1% and 0.3%, respectively. Salmonella was not isolated from the eggshells or the contents of the quail eggs. There was complete agreement between the results of m-PCR and the standard culture methods. Among the 18 tested antibiotics, the highest resistance was recorded for colistin (100%), followed by nalidixic acid (75%). CONCLUSION: As most Salmonella spp. are associated with human food poisoning, continuous surveillance is required to effectively reduce the risk posed by contaminated poultry eggs. Furthermore, mandatory monitoring of antimicrobial use on Iranian poultry farms is recommended.

Rapid detection of major enterotoxin genes and antibiotic resistance of Staphylococcus aureus isolated from raw milk in the Yazd province, Iran.

INTRODUCTION: Raw milk is a nutrient-rich food, but it may harbour harmful bacteria, such as enterotoxigenic Staphylococcus aureus (S. aureus), which can cause staphylococcal food poisoning. Antibiotic resistance of S. aureus in raw milk can increase the risk of such infections, particularly among susceptible individuals. OBJECTIVE: This study aimed to investigate the prevalence of enterotoxin genes a, d, g, i and j and the antibiotic resistance of S. aureus isolated from raw milk samples. METHODS: During a 6-month sampling period, 60 raw milk specimens were obtained from diverse locations in Yazd province, Iran. Antibiogram profiling was conducted via the disc diffusion method. In addition, staphylococcal enterotoxin (SE) genes a, d, g, i, and j were detected through real-time PCR analysis. RESULTS: Bacteriological assays confirmed the presence of S. aureus in 11 samples (18.3%). All isolates demonstrated 100% resistance to penicillin G but exhibited sensitivity to vancomycin, while resistance to other antibiotics ranged from 36.4% to 45.5%. The prevalence of enterotoxin genes in these strains showed variable distribution, with sea being the predominant SE (45.5%), followed by sed (36.4%), seg (18.2), sej and sei (9.1% each). CONCLUSIONS: This study discovered the presence of multiple enterotoxins in S. aureus strains obtained from raw milk samples. These strains also demonstrated resistance to a variety of antibiotics. Since enterotoxigenic S. aureus is known to cause human food poisoning, monitoring food hygiene practices, especially during raw milk production, is critical.

Isolation and characterization of the lactobacillus strain from honey and its probiotic properties.

Background and Objectives: The lactobacilli are abundant in honey, helping protect against pathogens and providing antimicrobial properties. This study aimed to isolate lactobacillus species from different honey regions and evaluate their potential probiotic properties. Materials and Methods: Eighty-eight samples were collected from different regions, including the northern, central, and southern areas, and obtained through retail stores. All samples were independently examined for the presence of Lactobacillus using both culture and real-time PCR methods. Probiotic tests were performed on the isolated Lactobacillus strains, including hemolytic activity, bile, acid, and pepsin resistance. Additionally, the antibiotic resistance of the obtained strains was investigated using seven different antibiotics. Results: Thirteen Lactobacillus isolates were obtained from 7 (8.0%) honey samples. Of these, eight isolates were identified as L. plantarum (61.54%), four isolates as L. rhamnosus (30.77%), and one isolate as L. acidophilus (7.69%). All strains were devoid of hemolytic activity, and three isolates (23.07%) were found to be resistant to acid, while 2 (15.38%) showed resistance to bile and pepsin. All isolates were resistant to vancomycin (100%). Additionally, only one strain exhibited resistance to all tested antibiotics. Furthermore, the present study demonstrates a significant association (p-value<0.05) between the presence of Lactobacillus in various regions of Iran. Conclusion: Various factors, such as climatic conditions and geographical location, can influence honey's composition and microbial diversity. Identifying and isolating potential probiotic species in honey could significantly expand their use in the food and pharmaceutical industries, offering numerous health benefits and potential therapeutic applications.

Direct Differentiation of Human Primary Fibroblast into Hematopoietic-Like Stem Cells; A New Way without Viral Transduction.

OBJECTIVE: The aim of this study was to investigate the possibility of producing safe hematopoietic stem cells without the use of viral infectious agents that can be used in stem cell transplantation. MATERIALS AND METHODS: In this experimental study, after single layer cell formation, human primary fibroblast cells were treated with static electromagnetic fields of 10 and 15 milli Tesla (mT) for 20 minutes each day for seven consecutive days. On the seventh day and immediately after the last radiation, the cells were added to the wells containing specific hematopoietic stem cell expansion media. After 21 days and colony formation, the cells belonging to each group were evaluated in terms of the expression of CD34, CD38, and GATA-1 genes using quantitative real-time polymerase chain reaction (PCR), as well as surface marker expression of CD34 by flow cytometry. RESULTS: Exposure to 10 mT and 15 mT electromagnetic field increased the expression of CD34 and CD38 genes (P<0.05). This increase in gene expression levels were 2.85 and 1.84 folds, respectively, in the 10mT group and 6.36 and 3.81 folds, respectively, in the 15 mT group. The expression of the GATA-1 gene in the 10 mT and 15 mT groups was not significantly different from that of the control group (P<0.05). Electromagnetic waves caused a marked increase in the expression of the CD34 marker at the surface of reprogrammed cells. The rate of expression was about 42.3% in the 15 mT group and 23.1% in the 10 mT group. CONCLUSION: The presence of human primary fibroblasts exposed to electromagnetic fields can increase the expression of specific hematopoietic genes. This method can be suitable for reprogramming cells differentiated into hematopoieticlike stem cells and does not pose the risks of retroviral use.

Integrated Cognitive Assessment: Speed and Accuracy of Visual Processing as a Reliable Proxy to Cognitive Performance.

Various mental disorders are accompanied by some degree of cognitive impairment. Particularly in neurodegenerative disorders, cognitive impairment is the phenotypical hallmark of the disease. Effective, accurate and timely cognitive assessment is key to early diagnosis of this family of mental disorders. Current standard-of-care techniques for cognitive assessment are primarily paper-based, and need to be administered by a healthcare professional; they are additionally language and education-dependent and typically suffer from a learning bias. These tests are thus not ideal for large-scale pro-active cognitive screening and disease progression monitoring. We developed the Integrated Cognitive Assessment (referred to as CGN_ICA), a 5-minute computerized cognitive assessment tool based on a rapid visual categorization task, in which a series of carefully selected natural images of varied difficulty are presented to participants. Overall 448 participants, across a wide age-range with different levels of education took the CGN_ICA test. We compared participants' CGN_ICA test results with a variety of standard pen-and-paper tests, such as Symbol Digit Modalities Test (SDMT) and Montreal Cognitive Assessment (MoCA), that are routinely used to assess cognitive performance. CGN_ICA had excellent test-retest reliability, showed convergent validity with the standard-of-care cognitive tests used here, and demonstrated to be suitable for micro-monitoring of cognitive performance.