# | Rank | Similarity | Title + Abs. | Year | PMID |
|---|---|---|---|---|---|
| 0 | 1 | 2 | 3 | 4 | 5 |
| 3760 | 0 | 0.9526 | Emergence of recurrent urinary tract infection: Dissecting the mechanism of antimicrobial resistance, host-pathogen interaction, and hormonal imbalance. Urinary tract infection is one of the most common infections worldwide, causing numerous deaths every year. The gut-bladder axis has been recently found to be a key factor in initiating UTI pathogenesis, along with the imbalance in the gut microbiome, which is associated with advanced susceptibility to rUTI. The patients who suffer from UTIs are, more often than not, the ones who have the lowest levels of butyrate-producing gut bacteria. Antibiotics cause dysbiosis in the gut and increase the growth of uropathogenic strains. Moreover, the gut-vagina and vagina-bladder axes are involved in UTIs by transferring microbial species, modulating the immune response, and developing intracellular bacterial reservoirs in the bladder. The rising usage of antibiotics has raised antimicrobial resistance (AMR) worldwide and recently worsened the treatment of UTIs. Resistance mechanisms include enzymatic hydrolysis of antibiotics, efflux systems, biofilm formation, horizontal gene transfer, and a weakened host's immune system, allowing bacteria to escape from the treatments. Besides, in pregnant women and adolescents, the alterations in sex hormone levels increase the risk of rUTIs. Knowledge of microbiota that inhabit the gut-vagina and vagina-bladder axes might lead to the invention of nonantibiotic preventive and therapeutic techniques in the future. In conclusion, this review emphasizes the need for a study to understand the host-microbe interactions, gut health, and AMR to effectively deal with and prevent recurrent UTIs. Also, the review explores a comprehensive analysis of the epigenetic network between host UTIs and marker genes in E. coli. The analysis showed seven genes associated with UTIs, namely, CXCL8, CDKN2A, RB1, EGFR, TP53, KRAS, and HRAS, are also implicated in bladder cancer. | 2025 | 40373943 |
| 6605 | 1 | 0.9495 | Antimicrobial Resistance in African Great Apes. BACKGROUND/OBJECTIVES: Antibiotic-resistant bacteria pose a significant global public health threat that demands serious attention. The proliferation of antimicrobial resistance (AMR) is primarily attributed to the overuse of antibiotics in humans, livestock, and the agro-industry. However, it is worth noting that antibiotic-resistant genes (ARGs) can be found in all ecosystems, even in environments where antibiotics have never been utilized. African great apes (AGAs) are our closest living relatives and are known to be susceptible to many of the same pathogens (and other microorganisms) as humans. AGAs could therefore serve as sentinels for human-induced AMR spread into the environment. They can potentially also serve as reservoirs for AMR. AGAs inhabit a range of environments from remote areas with little anthropogenic impact, over habitats that are co-used by AGAs and humans, to captive settings with close human-animal contacts like zoos and sanctuaries. This provides opportunities to study AMR in relation to human interaction. This review examines the literature on AMR in AGAs, identifying knowledge gaps. RESULTS: Of the 16 articles reviewed, 13 focused on wild AGAs in habitats with different degrees of human presence, 2 compared wild and captive apes, and 1 study tested captive apes alone. Ten studies included humans working with or living close to AGA habitats. Despite different methodologies, all studies detected AMR in AGAs. Resistance to beta-lactams was the most common (36%), followed by resistance to aminoglycosides (22%), tetracyclines (15%), fluoroquinolones (10%), sulphonamides (5%), trimethoprim (5%), macrolide (3%), phenicoles (2%) and fosfomycin (1%). CONCLUSIONS: While several studies suggest a correlation between increased human contact and higher AMR in AGAs, resistance was also found in relatively pristine habitats. While AGAs clearly encounter bacteria resistant to diverse antibiotics, significant gaps remain in understanding the underlying processes. Comparative studies using standardized methods across different sites would enhance our understanding of the origin and distribution of AMR in AGAs. | 2024 | 39766531 |
| 3118 | 2 | 0.9492 | Importance of Microbiome of Fecal Samples Obtained from Adolescents with Different Weight Conditions on Resistance Gene Transfer. Antimicrobial resistance (AMR) is a relevant public health problem worldwide, and microbiome bacteria may contribute to the horizontal gene transfer associated with antimicrobial resistance. The microbiome of fecal samples from Mexican adolescents were analyzed and correlated with eating habits, and the presence of AMR genes on bacteria in the microbiome was evaluated. Fecal samples from adolescents were collected and processed to extract genomic DNA. An Illumina HiSeq 1500 system was used to determine resistance genes and the microbiome of adolescents through the amplification of gene resistance and the V3-V4 regions of RNA, respectively. Analysis of the microbiome from fecal samples taken from 18 obese, overweight, and normal-weight adolescents revealed that the Firmicutes was the most frequent phylum, followed by Bacteroidetes, Actinobacteria, Proteobacteria and Verrucomicrobia. The following species were detected as the most frequent in the samples: F. prausnitzii, P. cori, B. adolescentis, E. coli and A. muciniphila. The presence of Bacteroides, Prevotella and Ruminococcus was used to establish the enterotype; enterotype 1 was more common in women and enterotype 2 was more common in men. Twenty-nine AMR genes were found for β-lactamases, fluoroquinolones, aminoglycosides, macrolide, lincosamides, streptogramin (MLS), tetracyclines and sulfonamides. The presence of microorganisms in fecal samples that harbor AMR genes that work against antimicrobials frequently used for the treatment of microbial infections such as b-lactams, macrolides, aminoglycosides, MLS, and tetracyclines is of great concern, as these organisms may be an important reservoir for horizontal AMR gene transfer. | 2022 | 36296271 |
| 6507 | 3 | 0.9489 | What Are the Drivers Triggering Antimicrobial Resistance Emergence and Spread? Outlook from a One Health Perspective. Antimicrobial resistance (AMR) has emerged as a critical global public health threat, exacerbating healthcare burdens and imposing substantial economic costs. Currently, AMR contributes to nearly five million deaths annually worldwide, surpassing mortality rates of any single infectious disease. The economic burden associated with AMR-related disease management is estimated at approximately $730 billion per year. This review synthesizes current research on the mechanisms and multifaceted drivers of AMR development and dissemination through the lens of the One Health framework, which integrates human, animal, and environmental health perspectives. Intrinsic factors, including antimicrobial resistance genes (ARGs) and mobile genetic elements (MGEs), enable bacteria to evolve adaptive resistance mechanisms such as enzymatic inactivation, efflux pumps, and biofilm formation. Extrinsic drivers span environmental stressors (e.g., antimicrobials, heavy metals, disinfectants), socioeconomic practices, healthcare policies, and climate change, collectively accelerating AMR proliferation. Horizontal gene transfer and ecological pressures further facilitate the spread of antimicrobial-resistant bacteria across ecosystems. The cascading impacts of AMR threaten human health and agricultural productivity, elevate foodborne infection risks, and impose substantial economic burdens, particularly in low- and middle-income countries. To address this complex issue, the review advocates for interdisciplinary collaboration, robust policy implementation (e.g., antimicrobial stewardship), and innovative technologies (e.g., genomic surveillance, predictive modeling) under the One Health paradigm. Such integrated strategies are essential to mitigate AMR transmission, safeguard global health, and ensure sustainable development. | 2025 | 40558133 |
| 8598 | 4 | 0.9483 | Nonnutritive sweeteners can promote the dissemination of antibiotic resistance through conjugative gene transfer. Antimicrobial resistance (AMR) poses a worldwide threat to human health and biosecurity. The spread of antibiotic resistance genes (ARGs) via conjugative plasmid transfer is a major contributor to the evolution of this resistance. Although permitted as safe food additives, compounds such as saccharine, sucralose, aspartame, and acesulfame potassium that are commonly used as nonnutritive sweeteners have recently been associated with shifts in the gut microbiota similar to those caused by antibiotics. As antibiotics can promote the spread of antibiotic resistance genes (ARGs), we hypothesize that these nonnutritive sweeteners could have a similar effect. Here, we demonstrate for the first time that saccharine, sucralose, aspartame, and acesulfame potassium could promote plasmid-mediated conjugative transfer in three established conjugation models between the same and different phylogenetic strains. The real-time dynamic conjugation process was visualized at the single-cell level. Bacteria exposed to the tested compounds exhibited increased reactive oxygen species (ROS) production, the SOS response, and gene transfer. In addition, cell membrane permeability increased in both parental bacteria under exposure to the tested compounds. The expression of genes involved in ROS detoxification, the SOS response, and cell membrane permeability was significantly upregulated under sweetener treatment. In conclusion, exposure to nonnutritive sweeteners enhances conjugation in bacteria. Our findings provide insight into AMR spread and indicate the potential risk associated with the presence of nonnutritive sweeteners. | 2021 | 33589766 |
| 3761 | 5 | 0.9483 | Stenotrophomonas maltophilia as an Emerging Ubiquitous Pathogen: Looking Beyond Contemporary Antibiotic Therapy. Stenotrophomonas maltophilia is a commensal and an emerging pathogen earlier noted in broad-spectrum life threatening infections among the vulnerable, but more recently as a pathogen in immunocompetent individuals. The bacteria are consistently being implicated in necrotizing otitis, cutaneous infections including soft tissue infection and keratitis, endocarditis, meningitis, acute respiratory tract infection (RTI), bacteraemia (with/without hematological malignancies), tropical pyomyositis, cystic fibrosis, septic arthritis, among others. S. maltophilia is also an environmental bacteria occurring in water, rhizospheres, as part of the animals' microflora, in foods, and several other microbiota. This review highlights clinical reports on S. maltophilia both as an opportunistic and as true pathogen. Also, biofilm formation as well as quorum sensing, extracellular enzymes, flagella, pili/fimbriae, small colony variant, other virulence or virulence-associated factors, the antibiotic resistance factors, and their implications are considered. Low outer membrane permeability, natural MDR efflux systems, and/or resistance genes, resistance mechanisms like the production of two inducible chromosomally encoded β-lactamases, and lack of carefully compiled patient history are factors that pose great challenges to the S. maltophilia control arsenals. The fluoroquinolone, some tetracycline derivatives and trimethoprim-sulphamethaxole (TMP-SMX) were reported as effective antibiotics with good therapeutic outcome. However, TMP-SMX resistance and allergies to sulfa together with high toxicity of fluoroquinolone are notable setbacks. S. maltophilia's production and sustenance of biofilm by quorum sensing enhance their virulence, resistance to antibiotics and gene transfer, making quorum quenching an imperative step in Stenotrophomonas control. Incorporating several other proven approaches like bioengineered bacteriophage therapy, Epigallocatechin-3-gallate (EGCG), essential oil, nanoemulsions, and use of cationic compounds are promising alternatives which can be incorporated in Stenotrophomonas control arsenal. | 2017 | 29250041 |
| 8597 | 6 | 0.9481 | Non-caloric artificial sweeteners exhibit antimicrobial activity against bacteria and promote bacterial evolution of antibiotic tolerance. Non-caloric artificial sweeteners are being widely used as safe table sugar substitutes with highly intensive sweetness but low calories. Previous studies have suggested that some of the sweeteners can alter the gut microbiota composition and promote horizontal transfer of antibiotic resistance genes across bacterial genera. However, little is known about whether these sweeteners could show antibiotic-like antimicrobial activity against bacteria, especially gut relevant bacteria. Whether they could affect evolutional trajectory of antibiotic resistance or tolerance in bacteria is also not clear yet. Here we investigated four commonly used artificial sweeteners (saccharin, sucralose, aspartame, and acesulfame potassium) against both Gram-negative (Escherichia coli and Klebsiella pneumoniae) and positive (Bacillus subtilis) strains. Results show that all four sweeteners exhibit antimicrobial effects on these strains. The antimicrobial mechanism is due to increased reactive oxygen species (ROS) and cell envelope damage. Compared to sucrose and glucose, the treatment of artificial sweeteners stimulates bacterial efflux pumps and promotes bacterial evolution of antibiotic tolerance. Collectively, our finding provides insights into roles of artificial sweeteners in the emergence of antibiotic tolerance and calls for a re-evaluation of risks due to their intensive usage. | 2022 | 35398799 |
| 6506 | 7 | 0.9481 | Mitigating antimicrobial resistance through effective hospital wastewater management in low- and middle-income countries. Hospital wastewater (HWW) is a significant environmental and public health threat, containing high levels of pollutants such as antibiotic-resistant bacteria (ARB), antibiotic-resistant genes (ARGs), antibiotics, disinfectants, and heavy metals. This threat is of particular concern in low- and middle-income countries (LMICs), where untreated effluents are often used for irrigating vegetables crops, leading to direct and indirect human exposure. Despite being a potential hotspot for the spread of antimicrobial resistance (AMR), existing HWW treatment systems in LMICs primarily target conventional pollutants and lack effective standards for monitoring the removal of ARB and ARGs. Consequently, untreated or inadequately treated HWW continues to disseminate ARB and ARGs, exacerbating the risk of AMR proliferation. Addressing this requires targeted interventions, including cost-effective treatment solutions, robust AMR monitoring protocols, and policy-driven strategies tailored to LMICs. This perspective calls for a paradigm shift in HWW management in LMIC, emphasizing the broader implementation of onsite treatment systems, which are currently rare. Key recommendations include developing affordable and contextually adaptable technologies for eliminating ARB and ARGs and enforcing local regulations for AMR monitoring and control in wastewater. Addressing these challenges is essential for protecting public health, preventing the environmental spread of resistance, and contributing to a global effort to preserve the efficacy of antibiotics. Recommendations include integrating scalable onsite technologies, leveraging local knowledge, and implementing comprehensive AMR-focused regulatory frameworks. | 2024 | 39944563 |
| 6636 | 8 | 0.9480 | The Contribution of Dairy Bedding and Silage to the Dissemination of Genes Coding for Antimicrobial Resistance: A Narrative Review. Antimicrobial resistance (AMR) is a concern in the dairy industry. Recent studies have indicated that bedding serves as a reservoir for antimicrobial-resistant bacteria and antimicrobial-resistance genes (ARGs), while silage has been proposed as another possible source. The impact of AMR in dairy farming can be significant, resulting in decreased productivity and economic losses for farmers. Several studies have highlighted the safety implications of AMR bacteria and genes in bedding and silage, emphasizing the need for further research on how housing, bedding, and silage management affect AMR in farm environments. Exposure to sub-lethal concentrations of antibiotics, such as those from contaminated bedding and silage, can prompt bacteria to develop resistance mechanisms. Thus, even if antimicrobial usage is diminished, ARGs may be maintained in the dairy farm environment. By implementing proactive measures to tackle AMR in dairy farming, we can take steps to preserve the health and productivity of dairy cattle while also protecting public health. This involves addressing the prudent use of antibiotics during production and promoting animal welfare, hygiene, and management practices in bedding and farm environments to minimize the risk of AMR development and spread. This narrative review compiles the growing research, positioning the contribution of bedding and silage to the prevalence and dissemination of AMR, which can elicit insights for researchers and policymakers. | 2024 | 39335078 |
| 6665 | 9 | 0.9480 | A One-Health Perspective of Antimicrobial Resistance (AMR): Human, Animals and Environmental Health. Antibiotics are essential for treating bacterial and fungal infections in plants, animals, and humans. Their widespread use in agriculture and the food industry has significantly enhanced animal health and productivity. However, extensive and often inappropriate antibiotic use has driven the emergence and spread of antimicrobial resistance (AMR), a global health crisis marked by the reduced efficacy of antimicrobial treatments. Recognized by the World Health Organization (WHO) as one of the top ten global public health threats, AMR arises when certain bacteria harbor antimicrobial resistance genes (ARGs) that confer resistance that can be horizontally transferred to other bacteria, accelerating resistance spread in the environment. AMR poses a significant global health challenge, affecting humans, animals, and the environment alike. A One-Health perspective highlights the interconnected nature of these domains, emphasizing that resistant microorganisms spread across healthcare, agriculture, and the environment. Recent scientific advances such as metagenomic sequencing for resistance surveillance, innovative wastewater treatment technologies (e.g., ozonation, UV, membrane filtration), and the development of vaccines and probiotics as alternatives to antibiotics in livestock are helping to mitigate resistance. At the policy level, global initiatives including the WHO Global Action Plan on AMR, coordinated efforts by (Food and Agriculture Organization) FAO and World Organisation for Animal Health (WOAH), and recommendations from the O'Neill Report underscore the urgent need for international collaboration and sustainable interventions. By integrating these scientific and policy responses within the One-Health framework, stakeholders can improve antibiotic stewardship, reduce environmental contamination, and safeguard effective treatments for the future. | 2025 | 41157271 |
| 6650 | 10 | 0.9479 | Antibiotic resistance is never going to go away. No matter how many drugs we throw at it, no matter how much money and resources are sacrificed to wage a war on resistance, it will always prevail. Humans are forced to coexist with the fact of antibiotic resistance. Public health officials, clinicians, and scientists must find effective ways to cope with antibiotic resistant bacteria harmful to humans and animals and to control the development of new types of resistance. The American Academy of Microbiology convened a colloquium October 12–14, 2008, to discuss antibiotic resistance and the factors that influence the development and spread of resistance. Participants, whose areas of expertise included medicine, microbiology, and public health, made specific recommendations for needed research, policy development, a surveillance network, and treatment guidelines. Antibiotic resistance issues specific to the developing world were discussed and recommendations for improvements were made. Each antibiotic is injurious only to a certain segment of the microbial world, so for a given antibacterial there are some species of bacteria that are susceptible and others not. Bacterial species insusceptible to a particular drug are “naturally resistant.” Species that were once sensitive but eventually became resistant to it are said to have “acquired resistance.” It is important to note that “acquired resistance” affects a subset of strains in the entire species; that is why the prevalence of “acquired resistance” in a species is different according to location. Antibiotic resistance, the acquired ability of a pathogen to withstand an antibiotic that kills off its sensitive counterparts, originally arises from random mutations in existing genes or from intact genes that already serve a similar purpose. Exposure to antibiotics and other antimicrobial products, whether in the human body, in animals, or the environment, applies selective pressure that encourages resistance to emerge favoring both “naturally resistant” strains and strains which have “acquired resistance.” Horizontal gene transfer, in which genetic information is passed between microbes, allows resistance determinants to spread within harmless environmental or commensal microorganisms and pathogens, thus creating a reservoir of resistance. Resistance is also spread by the replication of microbes that carry resistance genes, a process that produces genetically identical (or clonal) progeny. Rapid diagnostic methods and surveillance are some of the most valuable tools in preventing the spread of resistance. Access to more rapid diagnostic tests that could determine the causative agent and antibiotic susceptibility of infections would inform better decision making with respect to antibiotic use, help slow the selection of resistant strains in clinical settings, and enable better disease surveillance. A rigorous surveillance network to track the evolution and spread of resistance is also needed and would probably result in significant savings in healthcare. Developing countries face unique challenges when it comes to antibiotic resistance; chief among them may be the wide availability of antibiotics without a prescription and also counterfeit products of dubious quality. Lack of adequate hygiene, poor water quality, and failure to manage human waste also top the list. Recommendations for addressing the problems of widespread resistance in the developing world include: proposals for training and infrastructure capacity building; surveillance programs; greater access to susceptibility testing; government controls on import, manufacture and use; development and use of vaccines; and incentives for pharmaceutical companies to supply drugs to these countries. Controlling antibiotic resistant bacteria and subsequent infections more efficiently necessitates the prudent and responsible use of antibiotics. It is mandatory to prevent the needless use of antibiotics (e.g., viral infections; unnecessary prolonged treatment) and to improve the rapid prescription of appropriate antibiotics to a patient. Delayed or inadequate prescriptions reduce the efficacy of treatment and favor the spread of the infection. Prudent use also applies to veterinary medicine. For example, antibiotics used as “growth promoters” have been banned in Europe and are subject to review in some other countries. There are proven techniques for limiting the spread of resistance, including hand hygiene, but more rapid screening techniques are needed in order to effectively track and prevent spread in clinical settings. The spread of antibiotic resistance on farms and in veterinary hospitals may also be significant and should not be neglected. Research is needed to pursue alternative approaches, including vaccines, antisense therapy, public health initiatives, and others. The important messages about antibiotic resistance are not getting across from scientists and infectious diseases specialists to prescribers, stakeholders, including the public, healthcare providers, and public officials. Innovative and effective communication initiatives are needed, as are carefully tailored messages for each of the stakeholder groups. | 2009 | 32644325 |
| 6046 | 11 | 0.9478 | Safety Evaluations of Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI. Over the past decade, a variety of lactic acid bacteria have been commercially available to and steadily used by consumers. However, recent studies have shown that some lactic acid bacteria produce toxic substances and display properties of virulence. To establish safety guidelines for lactic acid bacteria, the Food and Agriculture Organization of the United Nations (FAO)/World Health Organization (WHO) has suggested that lactic acid bacteria be characterized and proven safe for consumers’ health via multiple experiments (e.g., antibiotic resistance, metabolic activity, toxin production, hemolytic activity, infectivity in immune-compromised animal species, human side effects, and adverse-outcome analyses). Among the lactic acid bacteria, Bifidobacterium and Lactobacillus species are probiotic strains that are most commonly commercially produced and actively studied. Bifidobacterium bifidum BGN4 and Bifidobacterium longum BORI have been used in global functional food markets (e.g., China, Germany, Jordan, Korea, Lithuania, New Zealand, Poland, Singapore, Thailand, Turkey, and Vietnam) as nutraceutical ingredients for decades, without any adverse events. However, given that the safety of some newly screened probiotic species has recently been debated, it is crucial that the consumer safety of each commercially utilized strain be confirmed. Accordingly, this paper details a safety assessment of B. bifidum BGN4 and B. longum BORI via the assessment of ammonia production, hemolysis of blood cells, biogenic amine production, antimicrobial susceptibility pattern, antibiotic resistance gene transferability, PCR data on antibiotic resistance genes, mucin degradation, genome stability, and possession of virulence factors. These probiotic strains showed neither hemolytic activity nor mucin degradation activity, and they did not produce ammonia or biogenic amines (i.e., cadaverine, histamine or tyramine). B. bifidum BGN4 and B. longum BORI produced a small amount of putrescine, commonly found in living cells, at levels similar to or lower than that found in other foods (e.g., spinach, ketchup, green pea, sauerkraut, and sausage). B. bifidum BGN4 showed higher resistance to gentamicin than the European Food Safety Authority (EFSA) cut-off. However, this paper shows the gentamicin resistance of B. bifidum BGN4 was not transferred via conjugation with L. acidophilus ATCC 4356, the latter of which is highly susceptible to gentamicin. The entire genomic sequence of B. bifidum BGN4 has been published in GenBank (accession no.: CP001361.1), documenting the lack of retention of plasmids capable of transferring an antibiotic-resistant gene. Moreover, there was little genetic mutation between the first and 25th generations of B. bifidum BGN4. Tetracycline-resistant genes are prevalent among B. longum strains; B. longum BORI has a tet(W) gene on its chromosome DNA and has also shown resistance to tetracycline. However, this research shows that its tetracycline resistance was not transferred via conjugation with L. fermentum AGBG1, the latter of which is highly sensitive to tetracycline. These findings support the continuous use of B. bifidum BGN4 and B. longum BORI as probiotics, both of which have been reported as safe by several clinical studies, and have been used in food supplements for many years. | 2018 | 29747442 |
| 7490 | 12 | 0.9478 | Effect of Phorate on the Development of Hyperglycaemia in Mouse and Resistance Genes in Intestinal Microbiota. Phorate is a systemic, broad-spectrum organophosphorus insecticide. Although it is commonly used worldwide, phorate, like other pesticides, not only causes environmental pollution but also poses serious threats to human and animal health. Herein, we measured the blood glucose concentrations of high-fat-diet-fed mice exposed to various concentrations of phorate (0, 0.005, 0.05, or 0.5 mg/kg); we also assessed the blood glucose concentrations of high-fat-diet-fed mice exposed to phorate; we also assessed the distribution characteristics of the resistance genes in the intestinal microbiota of these mice. We found that 0.005 and 0.5 mg/kg of phorate induced obvious hyperglycaemia in the high-fat-diet-fed mice. Exposure to phorate markedly reduced the abundance of Akkermansia muciniphila in the mouse intestine. The resistance genes vanRG, tetW/N/W, acrD, and evgS were significantly upregulated in the test group compared with the control group. Efflux pumping was the primary mechanism of drug resistance in the Firmicutes, Proteobacteria, Bacteroidetes, Verrucomicrobia, Synergistetes, Spirochaetes, and Actinobacteria found in the mouse intestine. Our findings indicate that changes in the abundance of the intestinal microbiota are closely related to the presence of antibiotic-resistant bacteria in the intestinal tract and the metabolic health of the host. | 2022 | 36358236 |
| 8833 | 13 | 0.9478 | "One for All": Functional Transfer of OMV-Mediated Polymyxin B Resistance From Salmonella enterica sv. Typhi ΔtolR and ΔdegS to Susceptible Bacteria. The appearance of multi-resistant strains has contributed to reintroducing polymyxin as the last-line therapy. Although polymyxin resistance is based on bacterial envelope changes, other resistance mechanisms are being reported. Outer membrane vesicles (OMVs) are nanosized proteoliposomes secreted from the outer membrane of Gram-negative bacteria. In some bacteria, OMVs have shown to provide resistance to diverse antimicrobial agents either by sequestering and/or expelling the harmful agent from the bacterial envelope. Nevertheless, the participation of OMVs in polymyxin resistance has not yet been explored in S. Typhi, and neither OMVs derived from hypervesiculating mutants. In this work, we explored whether OMVs produced by the hypervesiculating strains Salmonella Typhi ΔrfaE (LPS synthesis), ΔtolR (bacterial envelope) and ΔdegS (misfolded proteins and σ (E) activation) exhibit protective properties against polymyxin B. We found that the OMVs extracted from S. Typhi ΔtolR and ΔdegS protect S. Typhi WT from polymyxin B in a concentration-depending manner. By contrast, the protective effect exerted by OMVs from S. Typhi WT and S. Typhi ΔrfaE is much lower. This effect is achieved by the sequestration of polymyxin B, as assessed by the more positive Zeta potential of OMVs with polymyxin B and the diminished antibiotic's availability when coincubated with OMVs. We also found that S. Typhi ΔtolR exhibited an increased MIC of polymyxin B. Finally, we determined that S. Typhi ΔtolR and S. Typhi ΔdegS, at a lesser level, can functionally and transiently transfer the OMV-mediated polymyxin B resistance to susceptible bacteria in cocultures. This work shows that mutants in genes related to OMVs biogenesis can release vesicles with improved abilities to protect bacteria against membrane-active agents. Since mutations affecting OMV biogenesis can involve the bacterial envelope, mutants with increased resistance to membrane-acting agents that, in turn, produce protective OMVs with a high vesiculation rate (e.g., S. Typhi ΔtolR) can arise. Such mutants can functionally transfer the resistance to surrounding bacteria via OMVs, diminishing the effective concentration of the antimicrobial agent and potentially favoring the selection of spontaneous resistant strains in the environment. This phenomenon might be considered the source for the emergence of polymyxin resistance in an entire bacterial community. | 2021 | 34025627 |
| 814 | 14 | 0.9478 | Drown Them in Their Own Garbage: a New Strategy To Reverse Polymyxin Resistance? Purcell and colleagues offer new insights into a major mechanism of polymyxin resistance in Gram-negative bacteria (A. B. Purcell, B. J. Voss, and M. S. Trent, J Bacteriol 204:e00498-21, 2022, https://doi.org/10.1128/JB.00498-21). Inactivating a single lipid recycling enzyme causes accumulation of waste lipid by-products that inhibit a key factor responsible for polymyxin resistance. | 2022 | 34843378 |
| 6666 | 15 | 0.9477 | Antibiotic residues in poultry products and bacterial resistance: A review in developing countries. Antimicrobial resistance (AMR) is a growing global concern, particularly in poultry farming, where antibiotics are widely used for both disease prevention and growth promotion. This review examines the misuse of antibiotics in poultry production, especially in developing countries, and its contribution to the emergence of antibiotic-resistant bacteria. The findings highlight that factors such as increasing demand for poultry protein, the availability of inexpensive antibiotics, and weak regulatory oversight have led to widespread misuse, accelerating the spread of resistance genes. Although evidence links poultry farming to AMR, significant data gaps remain, especially regarding resistance transmission from poultry to humans. The review underscores the urgent need for stronger regulatory frameworks, phased-out use of antimicrobial growth promoters, and enhanced awareness campaigns to address this issue. Improving the capacity of regulatory bodies and developing more robust national data monitoring systems are essential steps to mitigate the threat of AMR in poultry farming and to protect both animal and human health. | 2024 | 39551017 |
| 4712 | 16 | 0.9477 | The chicken gut metagenome and the modulatory effects of plant-derived benzylisoquinoline alkaloids. BACKGROUND: Sub-therapeutic antibiotics are widely used as growth promoters in the poultry industry; however, the resulting antibiotic resistance threatens public health. A plant-derived growth promoter, Macleaya cordata extract (MCE), with effective ingredients of benzylisoquinoline alkaloids, is a potential alternative to antibiotic growth promoters. Altered intestinal microbiota play important roles in growth promotion, but the underlying mechanism remains unknown. RESULTS: We generated 1.64 terabases of metagenomic data from 495 chicken intestinal digesta samples and constructed a comprehensive chicken gut microbial gene catalog (9.04 million genes), which is also the first gene catalog of an animal's gut microbiome that covers all intestinal compartments. Then, we identified the distinctive characteristics and temporal changes in the foregut and hindgut microbiota. Next, we assessed the impact of MCE on chickens and gut microbiota. Chickens fed with MCE had improved growth performance, and major microbial changes were confined to the foregut, with the predominant role of Lactobacillus being enhanced, and the amino acids, vitamins, and secondary bile acids biosynthesis pathways being upregulated, but lacked the accumulation of antibiotic-resistance genes. In comparison, treatment with chlortetracycline similarly enriched some biosynthesis pathways of nutrients in the foregut microbiota, but elicited an increase in antibiotic-producing bacteria and antibiotic-resistance genes. CONCLUSION: The reference gene catalog of the chicken gut microbiome is an important supplement to animal gut metagenomes. Metagenomic analysis provides insights into the growth-promoting mechanism of MCE, and underscored the importance of utilizing safe and effective growth promoters. | 2018 | 30482240 |
| 6691 | 17 | 0.9477 | The antimicrobial resistance monitoring and research (ARMoR) program: the US Department of Defense response to escalating antimicrobial resistance. Responding to escalating antimicrobial resistance (AMR), the US Department of Defense implemented an enterprise-wide collaboration, the Antimicrobial Resistance Monitoring and Research Program, to aid in infection prevention and control. It consists of a network of epidemiologists, bioinformaticists, microbiology researchers, policy makers, hospital-based infection preventionists, and healthcare providers who collaborate to collect relevant AMR data, conduct centralized molecular characterization, and use AMR characterization feedback to implement appropriate infection prevention and control measures and influence policy. A particularly concerning type of AMR, carbapenem-resistant Enterobacteriaceae, significantly declined after the program was launched. Similarly, there have been no further reports or outbreaks of another concerning type of AMR, colistin resistance in Acinetobacter, in the Department of Defense since the program was initiated. However, bacteria containing AMR-encoding genes are increasing. To update program stakeholders and other healthcare systems facing such challenges, we describe the processes and impact of the program. | 2014 | 24795331 |
| 6664 | 18 | 0.9475 | Addressing the global challenge of bacterial drug resistance: insights, strategies, and future directions. The COVID-19 pandemic underscored bacterial resistance as a critical global health issue, exacerbated by the increased use of antibiotics during the crisis. Notwithstanding the pandemic's prevalence, initiatives to address bacterial medication resistance have been inadequate. Although an overall drop in worldwide antibiotic consumption, total usage remains substantial, requiring rigorous regulatory measures and preventive activities to mitigate the emergence of resistance. Although National Action Plans (NAPs) have been implemented worldwide, significant disparities persist, particularly in low- and middle-income countries (LMICs). Settings such as farms, hospitals, wastewater treatment facilities, and agricultural environments include a significant presence of Antibiotic Resistant Bacteria (ARB) and antibiotic-resistance genes (ARG), promoting the propagation of resistance. Dietary modifications and probiotic supplementation have shown potential in reshaping gut microbiota and reducing antibiotic resistance gene prevalence. Combining antibiotics with adjuvants or bacteriophages may enhance treatment efficacy and mitigate resistance development. Novel therapeutic approaches, such as tailored antibiotics, monoclonal antibodies, vaccines, and nanoparticles, offer alternate ways of addressing resistance. In spite of advancements in next-generation sequencing and analytics, gaps persist in comprehending the role of gut microbiota in regulating antibiotic resistance. Effectively tackling antibiotic resistance requires robust policy interventions and regulatory measures targeting root causes while minimizing public health risks. This review provides information for developing strategies and protocols to prevent bacterial colonization, enhance gut microbiome resilience, and mitigate the spread of antibiotic resistance. | 2025 | 40066274 |
| 6537 | 19 | 0.9475 | Antibiotic Abuse in Ornamental Fish: An Overlooked Reservoir for Antibiotic Resistance. Ornamental fish represent a significant aquaculture sector with notable economic value, yet their contribution to antibiotic residues and resistance remains underrecognized. This review synthesizes evidence on widespread and often unregulated antibiotic use-including tetracyclines and fluoroquinolones-in ornamental fish production, transportation, and retail, primarily targeting bacterial diseases such as aeromonosis and vibriosis. Pathogenic microorganisms including Edwardsiella, Flavobacterium, and Shewanella spp. cause diseases like hemorrhagic septicemia, fin rot, skin ulcers, and exophthalmia, impairing fish health and marketability. Prophylactic and therapeutic antibiotic applications elevate antibiotic residues in fish tissues and carriage water, thereby selecting for antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs). These resistant elements pose significant risks to fish health, human exposure via direct contact and bioaerosols, and environmental health through contamination pathways. We emphasize the urgent need for a holistic One Health approach, involving enhanced surveillance, stringent regulatory oversight, and adoption of alternative antimicrobial strategies, such as probiotics and advanced water treatments. Coordinated global actions are crucial to effectively mitigate antibiotic resistance within the ornamental fish industry, ensuring sustainable production, safeguarding public health, and protecting environmental integrity. | 2025 | 40284775 |