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.

Mechanism and antibacterial synergies of poly(Dabco-BBAC) nanoparticles against multi-drug resistant Pseudomonas aeruginosa isolates from human burns.

Multi-drug resistant bacteria are a major problem in the treatment of infectious diseases, such as pneumonia, meningitis, or even coronavirus disease 2019 (COVID-19). Cationic nanopolymers are a new type of antimicrobial agent with high efficiency. We synthesized and characterized cationic polymer based on 1,4-diazabicyclo [2.2.2] octane (DABCO) and Bis (bromoacetyl)cystamine (BBAC), named poly (DABCO-BBAC) nanoparticles(NPs), and produced 150 nm diameter NPs. The antibacterial activity of poly (DABCO-BBAC) against eight multi drug resistant (MDR) Pseudomonas aeruginosa isolates from human burns, its possible synergistic effect with gentamicin, and the mechanism of action were examined. Poly(DABCO-BBAC) could effectively inhibit and kill bacterial strains at a very low concentration calculated by minimum inhibitory concentration (MIC) assay. Nevertheless, its synergism index with gentamicin showed an indifferent effect. Moreover, transmission electron microscopy and lipid peroxidation assays showed that poly (DABCO-BBAC) distorted and damaged the bacterial cell wall. These results suggest that the poly (DABCO-BBAC) could be an effective antibacterial agent for MDR clinical pathogens.

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.

Role of neurotransmitters in immune-mediated inflammatory disorders: a crosstalk between the nervous and immune systems.

Immune-mediated inflammatory diseases (IMIDs) are a group of common heterogeneous disorders, characterized by an alteration of cellular homeostasis. Primarily, it has been shown that the release and diffusion of neurotransmitters from nervous tissue could result in signaling through lymphocyte cell-surface receptors and the modulation of immune function. This finding led to the idea that the neurotransmitters could serve as immunomodulators. It is now manifested that neurotransmitters can also be released from leukocytes and act as autocrine or paracrine modulators. Increasing data indicate that there is a crosstalk between inflammation and alterations in neurotransmission. The primary goal of this review is to demonstrate how these two pathways may converge at the level of the neuron and glia to involve in IMID. We review the role of neurotransmitters in IMID. The different effects that these compounds exert on a variety of immune cells are also reviewed. Current and future developments in understanding the cross-talk between the immune and nervous systems will undoubtedly identify new ways for treating immune-mediated diseases utilizing agonists or antagonists of neurotransmitter receptors.

Molecular typing of the actin gene of Trichomonas vaginalis isolates in Tehran, Iran.

Trichomonas vaginalis is a protozoan parasite that causes trichomoniasis with worldwide distribution. This study evaluated actin genotypes of T. vaginalis isolates using PCR-RFLP and sequence analysis in Tehran, Iran. Overall, 850 vaginal samples were collected from women admitted to hospitals affiliated with the Iran University of Medical Sciences in Tehran from 2020-to 2021. The samples were examined by wet mount and cultured. The parasites were harvested, and PCR-RFLP was performed using three endonuclease enzymes of HindII, MseI, and RsaI on all T. vaginalis isolates. Digestion patterns were then compared, and the genotype of these isolates was defined. The PCR products were sequenced. Overall, 12 (1.4%) isolates of T. vaginalis were identified from 850 vaginal samples collected. The most common genotypes were genotype E, seven (58.3%) and genotype G, three (25%), followed by genotype I, two (%16.7), using PCR-RFLP patterns and sequencing. No pattern indicative of mixed infection was found. PCR-RFLP is a proper technique to detect different T. vaginalis isolates, and noticeable polymorphism was found between isolates. Genotype E was the most common genotype in the studied group. The phylogenetic analysis indicated the T. vaginalis genotype E isolates in a distinct group compared to the genotypes G and I that evolved from a common ancestor.

Antibacterial, antibiofilm, anti-inflammatory, and wound healing effects of nanoscale multifunctional cationic alternating copolymers.

Infectious diseases caused by new or unknown bacteria and viruses, such as anthrax, cholera, tuberculosis and even COVID-19, are a major threat to humanity. Thus, the development of new synthetic compounds with efficient antimicrobial activity is a necessity. Herein, rationally designed novel multifunctional cationic alternating copolymers were directly synthesized through a step-growth polymerization reaction using a bivalent electrophilic cross-linker containing disulfide bonds and a diamine heterocyclic ring. To optimize the activity of these alternating copolymers, several different diamines and cross-linkers were explored to find the highest antibacterial effects. The synthesized nanopolymers not only displayed good to excellent antibacterial activity as judged by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) against Staphylococcus aureus, Enterococcus faecalis, Pseudomonas aeruginosa, and Escherichia coli, but also reduced the number of biofilm cells even at low concentrations, without killing mammalian cells. Furthermore, in vivo experiments using infected burn wounds in mice demonstrated good antibacterial activity and stimulated wound healing, without causing systemic inflammation. These findings suggest that the multifunctional cationic nanopolymers have potential as a novel antibacterial agent for eradication of multidrug resistant bacterial infections.

A review of the effects of the anesthetic gas nitrous oxide on the immune system; a starting point for future experiences.

Nitrous oxide is a common gas used as an anesthetic agent and analgesic medication in operating rooms. The gas inhibits vitamin B12 dependent-methionine synthase, which converts L-homocysteine and 5-methyltetrahydrofolate to L-methionine and tetrahydrofolate, respectively, via a methylation process. The immune system has been frequently reported to be suppressed in anesthetized subjects during the postoperative period. Although previous reviews have focused on the pathophysiologic role of nitrous oxide, none of them has considered the harmful effects of nitrous oxide on the Defense system of the host. In this article, the authors review current studies on the effects of nitrous oxide on the immune system of both patients undergoing surgery and occupational exposure, as well as preclinical studies. Moreover, this paper opens a new horizon for future studies in the context of underlying mechanisms of nitrous oxide actions on the immune system.

Prevalence of vaginolysin, sialidase and phospholipase genes in Gardnerella vaginalis isolates between bacterial vaginosis and healthy individuals.

Background: Gardnerella vaginalis is considered as the predominant microorganism found in bacterial vaginosis (BV). The aim of this study was to evaluate the prevalence of virulence factors in G. vaginalis associated with BV or non-BV cases and their correlations with this disorder. Methods: A total of 102 vaginal specimens were collected from patients during their visit to Akbar Abadi hospital in Tehran, Iran. Bacterial vaginosis was determined by Nugent score and Amsel's criteria. Polymerase chain reaction (PCR) was used for the detection of G. vaginalis 16S rRNA, vaginolysin, sialidase and phospholipase genes. To evaluate the association between the presence of vly, pho, and sld genes and BV. Pearson Chi-square test was applied using SPSS software. P-value ≤0.05 was considered as significant. Results: Totally, 27.4% of the patients were suffering from BV. Gardnerella vaginalis was found in 100% women with BV and in 56.7% women with normal vaginal discharge. The prevalence of vly, sld and pho genes in BV-associated G. vaginalis was 10 (35.7%) (95% CI [0.18, 0.53]), 19 (67.8%) (95% CI [0.51, 0.85]) and 6 (21.4%) (95% CI [0.06, 0.37]), respectively. The prevalence of the aforementioned genes in non-BV associated G. vaginalis was 20 (47.6%) (95% CI [0.33, 0.63]), 28 (66.6%) (95% CI [0.52, 0.81]), and 5 (11.9%) (95% CI [0.02, 0.22]), respectively. Our results showed no statistically significant association between the presence of the virulence genes and BV associatedness of this microorganism. Conclusion: Our results showed the presence of G. vaginalis in all BV patients and relatively high prevalence in healthy individuals. The prevalence rates of the three virulence genes were different in BV and non-BV associated G. vaginalis; however, the differences were not statistically significant.