Antibiotic Resistance Research Articles

Research progress in the design and application of whole-cell biosensors for antibiotics

Antibiotics are chemicals with bactericidal or bacteriostatic activity produced by microorganisms and artificially synthesized. Since the discovery of penicillin by Alexander Fleming in 1928, antibiotics have been widely used in clinical treatments as well as in the animal husbandry and aquaculture, leading to antibiotic residues in soil, water, food and other environments. At the same time, antibiotic resistance is increasingly serious, which necessitates the discovery of novel antibiotics. In recent years, with the development of synthetic biology, researchers have developed a variety of whole-cell biosensors that can respond to antibiotics. These whole-cell biosensors use microbial cells to convert antibiotic signals into readable signals, which can not only perform dynamic detection of antibiotics simply, quickly, sensitively and accurately but also effectively discover novel antibiotics. This review comprehensively summarizes the reported whole-cell biosensors for antibiotics, classifies them into two types (specific and general), and elaborates on the design principles and applications of the two types of antibiotic biosensors. This review will provide reference for the construction and application of other whole-cell biosensors for antibiotics.

Characterisation of Proteus mirabilis isolates from the poultry production chain in Zhejiang Province, China: antimicrobial resistance, virulence factors and genotypic profiling

ABSTRACT 1. This study investigated antimicrobial resistance, virulence factors and genotypic profiling among Proteus mirabilis isolated from three sources (poultry farms, slaughterhouses and retail markets) in the poultry production chain in Zhejiang Province, China, to assess its potential risk to public health. 2. A total of 112 P. mirabilis strains were isolated from 409 samples, including 35 from poultry farms, 35 from slaughterhouses and 42 from retail markets. Antimicrobial susceptibility was tested using 18 antimicrobials in 9 categories, in which 110 (98.2%) strains were considered multidrug-resistant (MDR). These strains carried numerous antimicrobial resistance genes, with the sulphonamide resistance gene (sul1) having the highest rate (100%) and the polymyxin resistance gene (mcr-1) the lowest (3.6%). 3. These isolates were validated to carry virulence genes pmfA, mrpA, atfC, rsbA, atfA, ureC and ucaA with the high prevalence of 96.4, 92.9, 92.0, 85.7, 85.7, 57.1 and 46.4%, respectively. Genotyping results using the ERIC-PCR indicated that the genetic similarity of all the isolates was 68.6% to 100% which fell into 4 clusters. 4. The P. mirabilis isolates from the slaughterhouses exhibited higher levels of antibiotic resistance and a more pronounced MDR phenomenon than those from poultry farms and retail markets. The proportion of isolates carrying the most commonly detected resistant and virulence genes was higher in samples from poultry farms and slaughterhouses as opposed to retail markets. Importantly, there was genetic similarity and heterogeneity among P. mirabilis isolates from the three sources and genotypic diversity was the highest among isolates from retail markets, followed by slaughterhouses and poultry farms.

Contextual Factors that Influence Antibiotic Prescribing: A Discrete Choice Experiment of GP Registrars.

Antimicrobial resistance is a global emergency related to overprescribing of antibiotics. Few studies have explored how prescribing behaviours may change as the consequence of changing resistance. Understanding how contextual factors influence antibiotic prescribing will facilitate improved communication strategies to promote appropriate antibiotic prescribing. We aimed to develop and conduct a discrete choice experiment (DCE) to measure how contextual factors influence intended antibiotic prescribing of general practitioner (GP) registrars. Factors included as attributes in the DCE were level of antibiotic resistance, requirement for an authority to prescribe, existence of a Practice Incentives Program (PIP) for low prescribing and supervisor support for low prescribing. The survey was administered in an online format for GP registrars undergoing training between 2020 and 2021. Regression analysis using a conditional logit model with interaction effects was used on the basis of the assumptions of independence of irrelevant alternatives, independence of error terms and no preference heterogeneity. In total, 617 unique respondents answered at least one choice set question. Respondents showed significant preference for avoiding prescribing antibiotics when antibiotic resistance was 25-35% or 40-60% compared with 5-8%. There was also a significant preference for avoiding prescribing when an authority to prescribe was required, or when there was supervisory support of low antibiotic prescribing. In the main effects analysis, respondents were significantly less likely to choose a prescribing option if there was a PIP; however, when interaction effects were included in the regression analysis there was a significant interaction between PIP and resistance rates, but the preference weights for PIP was no longer significant. Knowledge about community resistance impacts the stated intention of GP registrars to prescribe antibiotics. The use of the DCE may have made it possible to determine factors influencing prescribing that would not be detected using other survey methods. These findings provide guidance for producing, explaining and communicating issues regarding antibiotic prescribing to GP registrars.

Microplastics, Nanoplastics and Nanoparticles: Emerging Dynamic Carriers of Extracellular DNA Antibiotic Resistance Genes in the Environment

Microplastics, Nanoplastics and Nanoparticles: Emerging Dynamic Carriers of Extracellular DNA Antibiotic Resistance Genes in the Environment

Biodegradable film drip fertigation is more conducive to reducing the diversity and abundance of antibiotic resistance genes than plastic film drip fertigation

Biodegradable film drip fertigation is more conducive to reducing the diversity and abundance of antibiotic resistance genes than plastic film drip fertigation

Green solutions for treating groundwater polluted with nitrates, pesticides, antibiotics, and antibiotic resistance genes for drinking water production.

The present study evaluates for the first time the seasonal performance of an innovative green groundwater treatment. The pilot plant combines microalgae-bacteria treatment and a cork-wood biofilter to reduce nitrates, pesticides, antibiotics (ABs), and antibiotic resistance genes (ARGs) from groundwater. Groundwater had nitrate concentrations ranging from 220 to 410mg/L, while ABs (sulfonamides and fluoroquinolones) and pesticides (triazines) were detected at concentrations ranging from a few ng/L to 150ng/L. Only the gene targets sul1, tetM and the class 1 integron-integrase gene (intl1) were detected in the groundwater. The microalgae-biofilter treatment system effectively removed 15%-98% of nitrates, depending on the season, and consistently eliminated over 90% of ABs and pesticides year-round. Among the components of the treatment system, the microalgal system was the most effective at removing ABs and pesticides. However, the cork-wood biofilter showed superior performance in reducing the bacterial load in groundwater, achieving more than a 1-log reduction in the absolute abundance of genes such as sul1 and intl1. The accumulation of ABs and pesticides in microalgae biomass was minimal or undetectable (<20ng/g of fresh weight). Overall, our results indicate that the microalgae-biofilter treatment plant is an effective solution for significantly reducing nitrates, antibiotics, and pesticides from groundwaters, while also producing a valuable biomass, and meeting drinking water standards during warmer months.

Household waste-specific ambient air shows greater inhalable antimicrobial resistance risks in densely populated communities.

Household waste is a hotspot of antibiotic resistance, which can be readily emitted to the ambient airborne inhalable particulate matters (PM10) during the day-long storage in communities. Nevertheless, whether these waste-specific inhalable antibiotic resistance genes (ARGs) are associated with pathogenic bacteria or pose hazards to local residents have yet to be explored. By high-throughput metagenomic sequencing and culture-based antibiotic resistance validation, we analyzed 108 airborne PM10 and nearby environmental samples collected across different types of residential communities in Shanghai, the most populous city in China. Compared to the cold-dry period, the warm-humid season had significantly larger PM10-associated antibiotic resistomes in all types of residential communities (T-test, P < 0.001), most of airborne ARGs in which were estimatedly originated from disposed household waste (∼ 30%). In addition, the airborne bacteria were assembled in a deterministic approach (iCAMP, P<0.01), where the waste-specific bacteria taxa including Acinetobacter, Pseudomonas, Rhodococcus, and Kocuria had the predominant niches in the airborne microbial assemblages. Notably, these waste-sourced bacteria were also identified as the primary airborne hosts of ARGs encoding the aminoglycoside resistances. Among them, some antibiotic resistant human pathogens, such as Pseudomonas aeruginosa and Acinetobacter baumannii, not only exhibited higher ARG horizontal gene transfer (HGT) potential across the microbial assemblages, but also imposed direct infection risks on the local residents by 2min inhalation exposure per day. When the daily exposure duration increased to 11min, the infection-induced illness burden became unignorably high, especially in densely populated urban communities, being twofold greater than rural areas.

DoxyPEP Implementation Preferences for Bacterial STD Prevention Among Gay, Bisexual, and Other Men Who Have Sex with Men Living With and Without HIV in Los Angeles: A Mixed-Methods Approach.

Bacterial sexually transmitted diseases (STDs) remain prominent in the United States among gay, bisexual, and other men who have sex with men (GBMSM). Doxycycline for post-exposure prophylaxis (DoxyPEP) is a regimen by which the antibiotic doxycycline is taken after sex to prevent bacterial STDs, such as, chlamydia, gonorrhea, and syphilis. Despite this, this study was conducted because there are a limited number of publications that describe GBMSM's knowledge of, and interest in, taking DoxyPEP and preferences regarding its implementation. We conducted a mixed-methods study between November 2023 and March 2024. Participants (N = 21) completed a semi-structured interview and survey and were eligible if they were a cisgender man who reported having anal sex with another man in the past year and lived in the greater Los Angeles area. Interviews were recorded and transcribed and were analyzed using thematic content analysis. The majority of participants identified as gay (90%) and a racial/ethnic minority (86%); 33% were living with HIV and 43% had been diagnosed with an STD in the prior year. Participants' mean age was 40 years (standard deviation [SD] = 15) and they reported an average of 4.5 (SD = 2.27) sexual partners in the past year. Interviews revealed that knowledge of DoxyPEP was low (28%), but most (81%) were interested in using DoxyPEP after learning about its potential. The vast majority were willing to pay $10-$20 for a 1-month supply but preferred that it be free or covered by insurance. Most preferred to get DoxyPEP from a medical provider or over-the-counter at a pharmacy. Others suggested sexualized venues, such as private sex parties, bathhouses, sex clubs, etc. The greatest concerns about its use included possible side effects, antibiotic resistance, or that it would lead to decreased condom use and increased number of sex partners. A common misconception was that DoxyPEP could prevent both a bacterial STD and HIV. DoxyPEP has strong potential as a widely accepted STD prevention method, but its successful adoption will require proactive strategies to increase GBMSM's knowledge. Implementation programs might consider nontraditional venues where sex between men is regularly occurring.

Phenotypic and genotypic characterization of antimicrobial resistance and virulence profiles of Salmonella enterica serotypes isolated from necropsied horses in Kentucky.

This study focuses on understanding how Salmonella, specifically isolated from horses, can resist antibiotics and cause disease. Salmonella is a well-known foodborne pathogen that can pose risks not only to animals but also to humans. By studying the bacteria from necropsied horses, the research aims to uncover how certain Salmonella strains develop resistance to antibiotics and which genetic factors make them more dangerous. In addition to antibiotic resistance, the research explores the biofilm-forming ability of these strains, which enhances their survival in harsh environments. The study also investigates their motility, a factor that contributes to the spread of infection. The findings can improve treatment strategies for horses and help prevent the transmission of resistant bacteria to other animals as well as humans. Ultimately, the research could contribute to better management of antibiotic resistance in both veterinary and public health contexts, helping to safeguard animal welfare and public health.

Understanding bacterial ecology to combat antibiotic resistance dissemination.

The dissemination of antibiotic resistance from environmental sources is a growing concern. Despite the widespread occurrence of antibiotic resistance transmission events, there are actually multiple obstacles in the ecosystem that restrict the flow of bacteria and genes, in particular nonnegligible biological barriers. How these ecological factors help combat the dissemination of antibiotic resistance and relevant antibiotic resistance-diminishing organisms (ARDOs) deserves further exploration. This review summarizes the factors that influence the growth, metabolism, and environmental adaptation of antibiotic-resistant bacteria (ARB) and restrict the horizontal gene transfer (HGT) of antibiotic resistance genes (ARGs). Additionally, this review discusses the achievements in the application of ARDOs to improve biotechnology for wastewater and solid waste remediation while highlighting current challenges limiting their broader implementation.

Antibiotics for Paediatric Community-Acquired Pneumonia: What is the Optimal Course Duration?

Despite significant global reductions in cases of pneumonia during the last 3 decades, pneumonia remains the leading cause of post-neonatal mortality in children aged <5 years. Beyond the immediate disease burden it imposes, pneumonia contributes to long-term morbidity, including lung function deficits and bronchiectasis. Viruses are the most common cause of childhood pneumonia, but bacteria also play a crucial role. However, the optimal duration of antibiotic therapy for bacterial pneumonia remains uncertain in both low- and middle-income countries and in high-income countries. Knowing the optimal duration of antibiotic therapy for pneumonia is crucial for effective antimicrobial stewardship. This is especially important as concerns mount over rising antibiotic resistance in respiratory bacterial pathogens, which increases the risk of treatment failure. Numerous studies have focused on the duration of oral antibiotics and short-term outcomes, such as clinical cure and mortality. In contrast, only one study has examined both intravenous and oral antibiotics and their impact on long-term respiratory outcomes following pneumonia hospitalisation. However, study findings may be influenced by their inclusion criteria when children unlikely to have bacterial pneumonia are included. Efforts to differentiate between bacterial and non-bacterial pneumonia continue, but a validated, accurate, and simple point-of-care diagnostic test remains elusive. Without certainty that a child has bacterial pneumonia, determining the optimal duration of antibiotic treatment is challenging. This review examines the evidence for the recommended duration of antibiotics for treating uncomplicated pneumonia in otherwise healthy children and concludes that the question of duration is unresolved.

Pollution profiles, pathogenicity, and toxicity of bioaerosols in the atmospheric environment of urban general hospital in China.

Airborne microorganisms in hospitals present significant health risks to both patients and employees. However, their pollution profiles and associated hazards in different hospital areas remained largely unknown during the extensive use of masks and disinfectants. This study investigated the characteristics of bioaerosols in an urban general hospital during the COVID-19 pandemic and found that airborne bacteria and fungi concentrations range from 87±35 to 1037±275 CFU/m3 and 21±15 to 561±132 CFU/m3, respectively, with the outpatient clinic and internal medicine ward showing the highest levels. The operating room (OR) and clinical laboratory (LA) had lower bioaerosol levels but higher microbial activities, suggesting that disinfection procedures used to clean bioaerosols may change them into a viable but non-culturable state. The dominant fungi were Cladosporium, Aspergillus, and Penicillium, while the most common viruses were human associated gemykibivirus 2 and human alpha herpesvirus 1. Besides, the dominant pathogens were Staphylococcus aureus, Salmonella enterica, and Pseudomonas aeruginosa. Bacitracin and macrolides resistance genes bacA and ermC were the most prevalent subtypes of antibiotic resistance genes. Compared to the control sample, hospital-acquired bioaerosols, particularly from the outpatient examination room and emergency room can trigger higher levels of inflammatory factors and cell toxicity but lower cell proliferation rates. Lower cell toxicity was observed in low-risk areas (intensive care unit, LA, and OR). This study provides a new method for assessing bioaerosol health risks and enhances understanding of nosocomial and opportunistic infections and their control.

Arsenic-induced modulation of virulence and drug resistance in Pseudomonas aeruginosa.

Arsenic contamination of water sources, whether from natural or industrial origins, represents a significant risk to human health. However, its impact on waterborne pathogens remains understudied. This research explores the effects of arsenic exposure on the opportunistic pathogen Pseudomonas aeruginosa, a bacterium found in diverse environments. The arsenic exposure at concentrations of 0.12-20 mg/L As(III) resulted in rapid growth arrest of P. aeruginosa. Moreover, arsenic exposure significantly reduced the production of key virulence factors such as elastase (by 1.48- to 9.24-fold), pyocyanin, and flagella while increasing siderophore and extracellular polysaccharide production (by 1.44-1.75 and 1.36-2.59 times, respectively). Proteomic analysis revealed that both low (0.12 mg/L) and high (1.2 mg/L) As(III) levels activated an antioxidant defense response, with upregulation of Fnr-2, TrxB2, and Ohr. Furthermore, arsenic-induced the overexpression of multidrug resistance efflux proteins MexAB-OprM, MexCD-OprJ, and MexEF-OprN. At the same time, proteins associated with quorum sensing (QS), type III secretion system (T3SS), pyocyanin biosynthesis, and flagellar assembly were downregulated. In vitro assays confirmed that arsenic reduced bacterial virulence and significantly enhanced survival and proliferation under antibiotic treatment. These results indicate that arsenic exposure modulates the virulence and antibiotic resistance of P. aeruginosa, raising concerns about the public health risks posed by the convergence of arsenic-contaminated water and multidrug-resistant bacteria.

Antibiotic-free responsive biomaterials for specific and targeted Helicobacter pylori eradication.

Gastric cancer is highly correlated with Helicobacter pylori (H. pylori) infection. Approximately 50 % of the population worldwide is infected with H. pylori. However, current treatment regimens face severe challenges including drug resistance and gut microbiota disruption. An integrative treatment with slight negative influences on intestinal flora, conforming with concepts of integrative prevention of gastric cancer, is urgently needed. Non-antibiotic responsive biomaterials can respond to different stimuli, including pH, enzymes, light, ultrasound and magnetism, under which biomaterials are specifically activated to perform antibacterial capabilities, while neutral intestinal microenvironments differ from gastric microenvironments or inflammatory sites and have no or minimal irradiation via precisely controlled exogenous stimuli, which may not only overcome antibiotic resistance but also avoid gut microbiota disorders. First, the latest progress in responsive biomaterials against H. pylori without gut microbiome disturbance and their anti-H. pylori performances are profoundly summarized. Second, the mechanisms against planktonic bacteria, biofilms and intracellular bacteria are discussed respectively. Finally, the strategies of specific and targeted H. pylori elimination by responsive biomaterials are introduced. Additionally, the challenges and the focus of future research on translation into clinical application are fully proposed. Antibiotic-free responsive biomaterials for specific and targeted H. pylori eradication represent an innovative approach.

Optimized peptide inhibitor Aqs1C targets LasR to disrupt quorum sensing and biofilm formation in Pseudomonas aeruginosa: Insights from MD simulations and in vitro studies.

Pseudomonas aeruginosa (PA) is a critical pathogen, and its antibiotic resistance is largely driven by the quorum-sensing regulator LasR. Herein, we report the design, synthesis, and characterization of Aqs1C, a mutated peptide derivative of Aqs1, optimized to inhibit LasR and its quorum-sensing pathway. By introducing a targeted mutation, Aqs1C exhibited enhanced stability and binding affinity for LasR protein compared to its predecessor, Aqs1B. Using molecular dynamics simulations (MDS), the Aqs1C-LasR complex demonstrated a marked increase in structural stability, reflected in reduced root mean square deviation (RMSD) values and lower binding free energy. Electrostatic complementarity analysis showed stronger and more favorable interactions between Aqs1C and LasR. Further, GaMD experiments were able to reproduce the binding state between Aqs1C and LasR, indicating the binding mechanism between them. These molecular insights correlated with functional in vitro assays. Aqs1C effectively inhibited quorum-sensing-associated virulence factors in PA, involving biofilm formation (77.6 % inhibition), pyocyanin production (75.7 % inhibition), protease secretion (61.1 % inhibition), and rhamnolipid production (74.1 % inhibition), at a 100 μg/mL concentration, in a comparable or superior pattern to azithromycin (AZM). Molecular modelling, MDS, and GaMD insights and in vitro assays established Aqs1C as a promising candidate for therapeutic development to mitigate PA infections through targeted quorum-sensing disruption.

Global dissemination of Klebsiella pneumoniae in surface waters: Genomic insights into drug resistance, virulence, and clinical relevance.

The aquatic environment is a major pathway for the spread of antibiotic resistance (AR) among microorganisms. Among these, Klebsiella pneumoniae reveals high genome plasticity, adaptability, and the ability to colonize humans, animals, and the natural environment, awarding it a significant role in the spread of AR. This work presents an in-depth analysis of the whole sequences of 149 K. pneumoniae genomes isolated from surface waters available in databases. The sequences were obtained from 20 countries in five continents. The analyses showed a high genomic diversity of isolates, classifying them into 94 unique sequence types. The isolates carried numerous virulence and drug resistance determinants in their genomes, including genes for carbapenem and colistin resistance. The critical resistance genes were located on plasmids, indicating their high mobility and ease of access in water environments. Sublineage 258 members, in particular ST11, have been identified as important carriers of both important drug resistance determinants and key virulence factors, thus posing a substantial threat to human health. Our analysis revealed the direct transmission of drug-resistant and virulent clinical strains to the natural environment, highlighting the role of K. pneumoniae in the dissemination of drug resistance within the "One Health" framework. Surface waters represent an environment conducive to the spread and evolution of drug resistance, and K. pneumoniae plays a significant role in this process by providing clinically-significant antibiotic resistance genes to environmental recipients.

Understanding the bovine mastitis co-infections: Coexistence with Enterobacter alters S. aureus antibiotic susceptibility and virulence phenotype.

The World Health Organization recently reported an alarming evolution and spread of antibiotic resistance, a global risk factor recognized as a One Health challenge. In veterinary, the general lack of clear treatment guidelines often leads to antibiotic misuse. Bovine mastitis is responsible for major economic losses and the main cause of antibiotic administration in the dairy industry, favoring the emergence of multi-resistant phenotypes. The complexity of inter-microbial and host-pathogen interactions in the mammary gland, demonstrated by culture-independent techniques, not only complicates the prediction of antibiotic treatment outcomes but also underscores the urgent need for further research in this field. This work evaluated the interactions between S. aureus L33 and Enterobacter sp. L34 obtained from an intramammary co-infection. The behavior of the dual-species culture resembled that of the Enterobacter monoculture in all the evaluated contexts. Most of the selected S. aureus virulence factors and the antibiotic susceptibility were altered by coexisting with Enterobacter. Under the protection of Enterobacter, S. aureus was able to survive upon exposure to concentrations of cloxacillin and other antibiotics that would be bactericidal for the monoculture. This could have serious implications for bacterial clearance of mastitis originating from the underestimated co-infections. These findings highlight the importance of broadening our knowledge of how microbial interactions in intramammary infections could contribute to antibiotic treatments failures. Moreover, they open new perspectives for the design of bovine mastitis therapies that consider the ecological context in order to optimize the antibiotic usage, improve the success rates and reduce antibiotic resistance.

Unveiling Gelation and Antimicrobial Potentials of α-Acyloxy Carboxamides: Findings from Experimental and Theoretical Approach.

Multicomponent reactions have long been recognized as some of the most versatile tools in organic chemistry, with extensive applications in biomedical science and the pharmaceutical industry. In this study, we explored the potential of the Passerini reaction by designing and synthesizing new low molecular mass gelators that can serve as novel formulations for prolonged anesthesia. These gelators address critical issues like poor solubility, low bioavailability, and short plasma half-life, all of which hinder therapeutic efficacy. To further understand the gelation mechanism, we performed density functional theory (DFT) calculation for confirming the presence of non-covalent interactions during gel formation. Additionally, we evaluated the antimicrobial properties of the synthesized compounds, aiming to counter the rise of infectious diseases. These innovative antimicrobial agents could offer solutions to the growing problem of antibiotic resistance, which renders many existing therapies ineffective. Overall, this study aims to develop advanced formulations and antimicrobial agents through the Passerini reaction, providing new strategies for treating infections, minimizing side effects, and combating antibiotic resistance.

Prevalence of Plasmid-Mediated Fluoroquinolone Resistance Genes in Pseudomonas aeruginosa Among Patients at Aleppo University Hospital, Syria.

Pseudomonas aeruginosa is a significant opportunistic pathogen, especially in hospital-acquired infections, with plasmid-mediated fluoroquinolone resistance posing a major healthcare threat. This research aimed to isolate fluoroquinolone-resistant P. aeruginosa from patients at Aleppo University Hospital, assess the prevalence of fluoroquinolone resistance, confirm molecular identity, identify plasmid-associated resistance genes, and investigate virulence factors. A total of 430 samples were collected from patients and cultured on selective media for identification. Molecular confirmation was achieved through PCR techniques. Various media were used to assess virulence factors and antibiotic resistance while also investigating the prevalence of resistance-related genes. The study identified 29 fluoroquinolone-resistant P. aeruginosa isolates. These strains exhibited complete resistance to penicillins and all four generations of cephalosporins while remaining 100% sensitive to colistin. Notably, both hemolysin and gelatinase production rates were found to be 100%, and 48.2% of the isolates formed strong biofilms. The aac(6')-Ib gene was present in 72.4% of the isolates, the qnrS gene in 44.8%, and the qnrB gene in 13.7%. Additionally, 37.8% of the isolates contained two types of resistance genes, while 62% had one type. Importantly, all resistant isolates (100%) possessed at least four virulence factors. The findings indicate a prevalence of plasmid-associated fluoroquinolone resistance genes in the studied isolates. It is recommended to rationalize fluoroquinolone use to preserve their effectiveness against multidrug-resistant strains.

Parametric optimization, Polyphenol profiling and Bioefficacy of Bacopa monnieri (L.) Pennell phytoextract against multi-drug resistant (MDR) foodborne bacterial pathogens.

Nowadays, antimicrobial resistance and foodborne burden are a prevalent global concern for human health and sustainable development. In this context, this study aimed to investigate the effect of Bacopa monnieri (L.) Pennell extract against pathogenic foodborne bacteria (Escherichia coli, Staphylococcus aureus, and Listeria monocytogenes). Antibiogram phenotypic analysis on these strains revealed a high multiple antibiotic resistance (MAR) index, which varies from 0.5 to 0.75, and antibiotic resistance of 50-80 per cent. Polarity-wise extracted ethanolic extract (BM04-ET) showed potent anti-listerial (22.33±1.15mm) and anti-escherichial (20.33±0.58mm) potential with strong bactericidal activity against tested strains. In vitro phytochemical experiments confirmed a very high content of phenols (214.2±1.79mg/g and flavonoids (61.01±0.48mg/g) in BM04-ET; further confirmation via UPLC elucidated the abundance of natural bioactive flavanonol, i.e., dihydroquercetin (224.932μg/mL), possibly imparting bactericidal property to extract. Optimization studies identifies the best parametric combination with pH value of 6.8, temperature 37°C, and incubation period of 24h for the antibacterial effect of BM04-ET. Due to high polyphenolic content and superior antibacterial excellence, the study suggested B. monnieri ethanolic extract could be used as a choice in combating foodborne infection, and further research exploration on key antibacterial components turn out to be a remarkable milestone in food and medicinal industries.