Potential Causes of Spread of Antimicrobial Resistance and Preventive Measures in One Health Perspective-A Review

Organophosphate pesticides and their potential in the change of microbial population and frequency of antibiotic resistance genes in aquatic environments

Heavy metals (HMs) and pesticides disrupt aquatic biodiversity and microbial communities, contributing to antibiotic resistance via cross-resistance and co-selection mechanisms. This study investigates the relationship between organophosphorus pesticides (OPs), HMs, microbial diversity, and antibiotic resistance genes (ARGs) in eight lakes and wetlands. Microbial communities were analyzed via metagenomics methods, and data were processed using CLC Genomics Workbench 22. ARGs, including tetA, tetB, qnrA, qnrS, CIT, Fox, KPC, CTX-M1, DHA, GES, OXA, IMP, VEB, NDM1, SHV, TEM, CTX-M, PER, and MOX, were identified through polymerase chain reaction (PCR). Element concentrations and pesticide were quantified using inductively coupled plasma mass spectrometry and gas chromatography-mass spectrometry, respectively. The results indicate that environmental elements and pesticides significantly influence microbial diversity. Proteobacteria (Gamma, Beta, Alpha) dominate over other bacteria in all locations. β-Lactamase resistance genes have a significant positive correlations with the concentrations of boron, iron, lithium, magnesium, sodium, and phosphorus (P-value<0.05). Positive correlations between phosphorus, iron, and beta-lactamase genes suggest that higher concentrations of these elements may increase resistance likelihood by promoting resistant bacterial growth or facilitating gene transfer. Additionally, tetA and tetB exhibited a significant positive correlation with parathion concentration. The results showed that OPs and HMs increase antibiotic resistance by causing gene mutations, altering gene expression, and promoting horizontal gene transfer, resulting in multidrug-resistant strains. This highlights the need for monitoring these pollutants as they affect microbial diversity and accelerate antibiotic resistance. Targeted measures, such as bioremediation and pollution control, are essential to mitigate risks to the environment and public health.

Role of advanced cleaning and sanitation techniques in biofilm prevention on dairy equipment

Biofilm formation on dairy equipment is a persistent challenge in the dairy industry, contributing to product contamination, equipment inefficiency, and economic losses. Traditional methods such as manual cleaning and basic chemical sanitation are discussed as foundational approaches, followed by an in-depth investigation of cutting-edge technologies, including clean-in-place systems, high-pressure cleaning, foam cleaning, ultrasonic and electrochemical cleaning, dry ice blasting, robotics, nanotechnology-based agents, enzymatic cleaners, and oxidizing agents. Enhanced sanitation techniques, such as dry steam, pulsed light, acidic and alkaline electrolyzed water, hydrogen peroxide vapor, microbubble technology, and biodegradable biocides, are highlighted for their potential to achieve superior sanitation while promoting sustainability. The effectiveness, feasibility, and limitations of these methods are evaluated, emphasizing their role in maintaining dairy equipment hygiene and reducing biofilm-associated risks. Additionally, challenges, such as equipment compatibility, cost, and regulatory compliance, are addressed, along with insights into future directions and innovations, including automation, smart cleaning systems, and green cleaning solutions. This review provides a comprehensive resource for researchers, industry professionals, and policymakers aiming to tackle biofilm formation in dairy production systems and enhance food safety, operational efficiency, and sustainability.

Acinetobacter baumannii: A comprehensive review of global epidemiology, clinical implications, host interactions, mechanisms of antimicrobial resistance and mitigation strategies

Since the discovery of Acinetobacter baumannii, it has emerged as a significant global health threat due to its increasing prevalence in healthcare settings and remarkable ability to develop resistance to various antibiotics. This detailed review addresses global epidemiology, emphasizing the worldwide distribution of carbapenem-resistant A. baumannii (CRAb), which is particularly prevalent in high-density healthcare settings and regions with intensive antibiotic usage, such as India. Clinically, A. baumannii infection poses serious health challenges, with mortality rates ranging from 30 % to 75 % for multidrug-resistant (MDR) strains. The review highlights the clinical impact and disease spectrum of A. baumannii, associated with pneumonia, wound infections, bloodstream infections, and, urinary tract infections with a strong association to invasive medical procedures and devices. Additionally, it discusses human-pathogen interactions by exploring various mechanisms, persistence in hospital environments, and survival under harsh conditions. The review further elaborates on different resistance mechanisms, focusing broadly on antibiotic degradation, altered drug targets, reduced drug permeability, and efflux systems, which facilitate the survival and persistence of A. baumannii. Finally, it evaluates strategies to combat AMR, emphasizing infection control measures, antimicrobial stewardship, and the urgent need for innovative therapeutic approaches such as phage therapy and new antibiotic development. The review calls for concerted, collaborative efforts among researchers, healthcare professionals, and public health authorities to mitigate the global threat posed by MDR A. baumannii strains.

Status and implications of the knowledge, attitudes and practices towards AWaRe antibiotic use, resistance and stewardship among low- and middle-income countries

Background

There are concerns globally with rising rates of antimicrobial resistance (AMR), particularly in low- and middle-income countries (LMICs). AMR is driven by high rates of inappropriate prescribing and dispensing of antibiotics, particularly Watch antibiotics. To develop future interventions, it is important to document current knowledge, attitudes and practices (KAP) among key stakeholder groups in LMICs.

Methods

We undertook a narrative review of published papers among four WHO Regions including African and Asian countries. Relevant papers were sourced from 2018 to 2024 and synthesized by key stakeholder group, country, WHO Region, income level and year. The findings were summarized to identify pertinent future activities for all key stakeholder groups.

Results

We sourced 459 papers, with a large number coming from Africa (42.7%). An appreciable number dealt with patients' KAP (33.1%), reflecting their influence on the prescribing and dispensing of antibiotics. There was marked consistency of findings among key stakeholder groups across the four WHO Regions, all showing concerns with high rates of prescribing of antibiotics for viral infections despite professed knowledge of antibiotics and AMR. There were similar issues among dispensers. Patients' beliefs regarding the effectiveness of antibiotics for self-limiting infectious diseases were a major challenge, although educational programmes did improve knowledge. The development of the AWaRe (Access, Watch and Reserve) system, including practical prescribing guidance, provides a future opportunity for the standardization of educational inputs.

Conclusions

Similar KAP regarding the prescribing and dispensing of antibiotics across LMICs and stakeholder groups presents clear opportunities for standardization of educational input and practical training programmes based on the AWaRe system.

Epidemiological characteristics of antibiotic resistance genes in various bacteria worldwide

OBJECTIVES

This study aims to investigate the epidemiological characteristics of various bacteria carrying ARGs on a global scale over extended time periods.

METHODS

A total of 25,285 globally isolated bacteria's genomes were analyzed to explore ARGs. The analysis focused on temporal, geographic, and species distribution, including pathogenic and non-pathogenic bacteria, intracellular parasitic states, ARG types, and their association with MGEs. Multiple linear regression was employed to identify ARG risk factors in bacteria.

RESULTS

The overall prevalence of bacteria with ARGs was 64.2%, indicating that at least one ARG was present in 64.2% (16,243/25,285) of the included bacterial, with an average of 14.4 ARGs per bacterium. ARGs have been increasing globally, averaging one additional ARG every three years, closely linked to rising antibiotic consumption. Pathogenic bacteria harbored more ARGs than non-pathogenic ones. Intracellular parasitic bacteria still carry specific types of ARGs despite being less likely to generate ARGs. Clinical and human-associated bacteria showed higher ARG counts, and bacteria isolated from humans had the highest number of disinfectant-resistant genes. The average number of ARGs in bacteria isolated from high-middle-income and lower-middle-income countries is higher. Factors like motility, non-sporulation, Gram-positive staining, extracellular parasitism, and human pathogenicity are linked to higher ARGs levels.

CONCLUSIONS

An increasing number of bacteria carrying ARGs pose a significant challenge to the control of antibiotics-resistant pathogens worldwide. The issue of bacteria carrying more ARGs requires greater global attention.

A systematic review and meta-analysis on antibiotic resistance genes in Ghana

BACKGROUND

Addressing antimicrobial resistance (AMR) poses a complex challenge, primarily because of the limited understanding of bacterial antibiotic resistance genes (ARGs) and the spread of these genes across different domains. To bridge this knowledge gap in Ghana, we undertook a comprehensive systematic review and meta-analysis to quantify and estimate the prevalence of circulating ARGs in bacteria isolated from human, animal, and environmental sources.

METHODS

A thorough literature search was conducted across three major databases-Web of Science, PubMed, and Scopus-to retrieve all relevant articles related to ARGs in Ghana from the inception of the databases to February 25, 2024. A risk-of-bias evaluation was performed using the Newcastle-Ottawa Scale (NOS), and the data analysis involved descriptive statistics and proportional meta-analysis.

RESULTS

Of the 371 articles initially obtained, 38 met the inclusion criteria. These studies adequately covered Ghana geographically. The most prevalent ESBL gene identified was blaCTX-M, with a prevalence of 31.6% (95% CI: 17.6-45.7), followed by blaTEM (19.5% [95% CI: 9.7-29.3]), and blaSHV (3.5% [95% CI: 0.3-6.6]). The pooled prevalence of carbapenemase genes ranged from 17.2% (95% CI: 6.9-27.6) for blaNDM to 10.3% (95% CI: 1.9-18.7) for blaOXA. Additionally, other ARGs, including sul1, qnrS, gyrA, erm(B), and mecA, were detected, with prevalence ranging from 3.9% (95% CI: 0.0-8.5) to 16.4% (95% CI: 3.1-29.8). Several ARGs were shared across human, animal, and environmental sources.

CONCLUSION

This review revealed that bacteria obtained from human, animal, and environmental samples in Ghana shared genes associated with AMR. This finding provides evidence on the interconnection of AMR across these three domains. Horizontal gene transfer, which enables the dissemination of ARGs between genetically diverse bacteria, can occur, necessitating a multidisciplinary approach to addressing antimicrobial resistance in Ghana.

Observed Prevalence and Characterization of Fluoroquinolone-Resistant and Multidrug-Resistant Bacteria in Loggerhead Sea Turtles (Caretta caretta) from the Adriatic Sea

Background/Objectives: Antimicrobial resistance (AMR) is a major global health concern with profound implications for human, animal, and environmental health. Marine ecosystems are emerging as reservoirs of resistant bacteria due to contamination from anthropogenic activities. This study aimed to investigate fluoroquinolone-resistant and multidrug-resistant bacteria in loggerhead sea turtles (Caretta caretta). Methods: Cloacal swabs were collected from 28 loggerhead sea turtles at a rescue center in southern Italy. Swabs were cultured in nutrient media supplemented with enrofloxacin. Bacterial isolates underwent identification by MALDI-TOF, antimicrobial susceptibility testing, and assessment for multidrug resistance. Conjugation experiments evaluated the transferability of enrofloxacin resistance. Results: Thirty-six enrofloxacin-resistant bacterial strains were isolated from 22 turtles. The identified species included Vagococcus fluvialis (13 strains), Citrobacter freundii (5), Escherichia coli (6), and Pseudomonas mendocina (4). Thirty-five isolates exhibited multidrug resistance, with resistance to critically important antibiotics such as imipenem observed in C. freundii and Enterobacter faecium. Conjugation experiments showed no transfer of resistance genes. Conclusions: The study highlights the prevalence of fluoroquinolone-resistant and multidrug-resistant bacteria in C. caretta, implicating marine environments as reservoirs of AMR. The findings underscore the need for stricter regulation of antimicrobial use and monitoring of resistance dissemination in marine ecosystems. These results contribute to understanding AMR dynamics within the One Health framework, emphasizing the interconnectedness of environmental, animal, and human health.

Veterinarians approach towards antimicrobial stewardship and one health: A survey study

Antimicrobial resistance (AMR) is one of the top 10 global public health threats. One Health approach is needed to tackle antimicrobial resistance as most antimicrobials used in animals are also used in humans and affect the environment. Although the knowledge and attitudes of personnel in the human healthcare sector are studied more frequently in Gujarat, veterinarians' approaches also play a pivotal role in attaining antimicrobial stewardship. Thus, an online survey was conducted to understand the knowledge, attitudes, and practices of veterinarians regarding AMR and antimicrobial stewardship in Gujarat. A total of 691 respondents included 300 government veterinarians (44 %), 258 cooperative veterinarians (37 %), 45 private veterinarians (5 %), 69 MVD GVK veterinarians (10 %), and 19 others (4 %). Several veterinarians (77 %) believe that farmers' misuse of antimicrobials contributes significantly to AMR. According to 78 % of respondents, the inappropriate use of antimicrobials in food-producing animals contributes to AMR, which can be reduced by vaccines, biosecurity measures, and hygiene (79 %). As per 86 % of the responders, antimicrobial stewardship is important, and 81 % educate farmers on the rational use of antimicrobials. Though 92 % of veterinarians agreed that culture and antimicrobial sensitivity testing (AST) should be done as frequently as possible to guide antimicrobial usage, only 4 % always, and 68 % sometimes send samples for AST. However, 31 % think it is acceptable to commence antimicrobial therapy without a confirmatory diagnosis. The study findings suggest that AMR awareness among farmers, increased provision of laboratory services, and AST at affordable costs should be developed to combat the development of AMR.

Advancements in Antibacterial Therapy: Feature Papers

Antimicrobial resistance (AMR) is a growing global health crisis that threatens the efficacy of antibiotics and modern medical interventions. The emergence of multidrug-resistant (MDR) pathogens, exacerbated by the misuse of antibiotics in healthcare and agriculture, underscores the urgent need for innovative solutions. (1) Background: AMR arises from complex interactions between human, animal, and environmental health, further aggravated by the overuse and inadequate regulation of antibiotics. Conventional treatments are increasingly ineffective, necessitating alternative strategies. Emerging approaches, including bacteriophage therapy, antimicrobial peptides (AMPs), nanotechnology, microbial extracellular vesicles (EVs), and CRISPR-based antimicrobials, provide novel mechanisms that complement traditional antibiotics in combating resistant pathogens. (2) Methods: This review critically analyzes advanced antibacterial strategies in conjunction with systemic reforms such as antimicrobial stewardship programs, the One Health framework, and advanced surveillance tools. These methods can enhance resistance detection, guide interventions, and promote sustainable practices. Additionally, economic, logistical, and regulatory challenges impeding their implementation are evaluated. (3) Results: Emerging technologies, such as CRISPR and nanotechnology, exhibit promising potential in targeting resistance mechanisms. However, disparities in resource distribution and regulatory barriers hinder widespread adoption. Public-private partnerships and sustainable agriculture practices are critical to overcoming these obstacles. (4) Conclusions: A holistic and integrated approach is essential for mitigating the impact of AMR. By aligning innovative therapeutic strategies with global health policies, fostering interdisciplinary collaboration, and ensuring equitable resource distribution, we can develop a sustainable response to this 21st-century challenge.

A mixed-method study on antimicrobial resistance infection drivers in neonatal intensive care units: pathways, risks, and solutions

BACKGROUND

Antimicrobial resistance (AMR) in neonatal intensive care units (NICUs) complicates treatment of healthcare-associated infections, causing high morbidity and mortality, especially among low-birth-weight and critically ill infants. This study evaluates AMR prevalence, risk factors, outcomes and infection control measures at Felege Hiwot Hospital, aiming to guide clinical practices, antimicrobial stewardship, and improved neonatal health outcomes.

METHODS

This mixed-methods study (Oct 2022-Jun 2023) assessed AMR in NICU neonates by analyzing 420 blood samples, environmental swabs, and staff insights. Bivariable and multivariable regressions identified significant variables, and content analysis was used for qualitative data.

RESULTS

Out of 420 samples, 35% tested positive for AMR pathogens, with Coagulase-Negative Staphylococci (16.7%), Klebsiella pneumoniae (12.9%), and Acinetobacter spp. (5.6%) being the most prevalent. Resistance rates for Gentamicin, Cotrimoxazole, and Ciprofloxacin were alarmingly high (98-100%), while Amikacin demonstrated low resistance (3.0-5.56%), indicating potential efficacy. Among the neonates admitted, 91.8% survived, and 8.2% succumbed. Risk factor analysis revealed that improper PPE usage (AOR 3.90, p < 0.001), non-functional handwashing sinks (AOR 3.20, p < 0.001), and inadequate disinfection practices (AOR 2.70, p < 0.001) were strongly associated with microbial contamination. Environmental factors, including cockroach presence (AOR 1.80, p = 0.040) and high traffic flow (AOR 2.10, p = 0.005), were also significant contributors. The qualitative data analysis confirmed that improper PPE use, inadequate disinfection practices, pest control challenges, and non-functional handwashing sinks significantly contributed to microbial contamination risks in the NICU, aligning with the quantitative findings.

CONCLUSIONS

This study underscores key factors driving AMR in NICUs, such as inadequate IPC practices and environmental contamination, alongside high resistance to Cotrimoxazole and Ciprofloxacin. Amikacin shows promise as an effective treatment for CONS. Urgent actions, including strengthened IPC measures, staff training, and environmental management, are crucial to combat AMR, ensuring improved neonatal care and outcomes.

Dealing with Challenges Posed by Antimicrobial Resistance in Long-Term Acute-Care Rehabilitation Facilities

Antimicrobial resistance (AMR) has emerged as one of the major challenges for human health, with a remarkable burden of mortality, morbidity, and healthcare-associated costs [...].

Prevalence and Antimicrobial Resistance Patterns of Escherichia coli in the Environment, Cow Dung, and Milk of Selangor Dairy Farms

BACKGROUND/OBJECTIVES

The increasing threat of antimicrobial resistance (AMR) to global public health urgently needs attention. Misuse of antimicrobials in sectors such as dairy farming has led to the emergence and spread of resistant bacteria and genes. This study investigated AMR patterns and profiles of Escherichia coli (E. coli) from various sources, including soil, effluent, cow dung, and milk.

METHODS

A total of 192 samples were collected, comprising environmental samples (soil and effluent), cow dung samples, and milk samples from eight dairy farms in Selangor, Malaysia. The spread plate method was employed to isolate E. coli, and all the isolates were subjected to Gram staining to identify Gram-negative, rod-shaped bacteria. The Vitek® 2 system was used for E. coli identification and susceptibility testing.

RESULTS

The prevalence of E. coli identified in the eight farms was 66.1%. A total of 360 E. coli isolates were successfully isolated, and 19.7% of the isolates presented AMR with ampicillin exhibiting the highest resistance (18.3%), followed by trimethoprim-sulfamethoxazole (8.9%). Additionally, 8.9% of them were multidrug resistant, which could be divided into 16 patterns. For the extended spectrum beta-lactamase screening, nine isolates were positive.

CONCLUSIONS

This finding emphasizes the rise in resistant isolates in the growing dairy industry and underscores the urgency of addressing the potential reservoir of AMR. Therefore, essential measures such as continuous surveillance and effective antimicrobial stewardship programs are crucial for regulating veterinary antimicrobial use. Research on the mechanisms driving the development and dissemination of AMR is imperative for addressing One Health concerns.

Acinetobacter baumannii infection in critically ill patients with COVID-19 from Tehran, Iran: the prevalence, antimicrobial resistance patterns and molecular characteristics of isolates

Background

The COVID-19 pandemic has led to the excessive use of antimicrobials in critically ill patients. Infections caused by Acinetobacter baumannii have increased significantly both regionally and globally during the COVID-19 pandemic, posing dramatic challenges for intensive care unit (ICU) patients. This study aimed to determine the prevalence, antimicrobial resistance patterns, presence of selected antimicrobial resistance genes, and genetic diversity of A. baumannii isolates obtained from COVID-19 cases admitted to the ICU at the University Hospital in Iran.

Materials and methods

This was a cross-sectional and single-center study comprising patients with A. baumannii infections admitted to the ICU with COVID-19 between April and November 2021. The demographic and clinical data of the patients were collected. Antimicrobial susceptibility testing was conducted based on Clinical Laboratory Standards Institute guidelines. This study used PCR and multiplex PCR to investigate antibiotic resistance genes (ARGs) and global clones (GC), respectively. Genetic diversity was investigated by repetitive element sequence-based PCR (REP-PCR).

Results

The prevalence of A. baumannii coinfection in COVID-19 cases was 8.1% (43/528). More than 90% (39/43) of A. baumannii isolates were resistant to cefepime, ampicillin-sulbactam, gentamicin, trimethoprim-sulfamethoxazole and amikacin. Furthermore, 44.2% (19/43) of isolates were resistant to colistin. There were 91% (39/43) isolates that were extensively drug-resistant (XDR). The most prevalence carbapenem resistance encoding genes were bla -OXA-23 65.1% (29/43) and bla NDM 41.8% (18/43). The most common aminoglycoside resistance genes were aac(6')-Ib 65.1% (28/43) and ant(2)-Ia 46.5% (20/43). Isolates from the prominent Global clone GCII comprised 83.7% (36/43) of total isolates. Genetic fingerprinting using REP-PCR revealed that 39 typeable A. baumannii isolates were categorized into 12 distinct genotypes, of which 72% (28/39) of isolates belonged to one genotype.

Conclusion

The high prevalence of XDR A. baumannii such as carbapenem and colistin-resistant strains, poses a significant concern for the treatment of COVID-19 patients, heightening the risk of therapeutic failure. The data demonstrate the dissemination of a single A. baumannii clone carrying multiple ARGs within our hospital. Regarding the limited therapeutic options, it is crucial to implement effective prevention and containment policies to curb the spread of these strains.

The role of artificial intelligence and machine learning in predicting and combating antimicrobial resistance

Antimicrobial resistance (AMR) is a major threat to global public health. The current review synthesizes to address the possible role of Artificial Intelligence and Machine Learning (AI/ML) in mitigating AMR. Supervised learning, unsupervised learning, deep learning, reinforcement learning, and natural language processing are some of the main tools used in this domain. AI/ML models can use various data sources, such as clinical information, genomic sequences, microbiome insights, and epidemiological data for predicting AMR outbreaks. Although AI/ML are relatively new fields, numerous case studies offer substantial evidence of their successful application in predicting AMR outbreaks with greater accuracy. These models can provide insights into the discovery of novel antimicrobials, the repurposing of existing drugs, and combination therapy through the analysis of their molecular structures. In addition, AI-based clinical decision support systems in real-time guide healthcare professionals to improve prescribing of antibiotics. The review also outlines how can AI improve AMR surveillance, analyze resistance trends, and enable early outbreak identification. Challenges, such as ethical considerations, data privacy, and model biases exist, however, the continuous development of novel methodologies enables AI/ML to play a significant role in combating AMR.

Genomic Characterization of Carbapenemase-Producing Enterobacteriaceae from Clinical and Epidemiological Human Samples

Background/Objectives: Infections caused by multidrug-resistant (MDR)bacteria pose a significant public health threat by worsening patient outcomes, contributing to hospital outbreaks, and increasing health and economic burdens. Advanced genomic tools enhance the detection of resistance genes, virulence factors, and high-risk clones, thus improving the management of MDR infections. In the Autonomous Community of Aragon, the diversity and incidence of carbapenemase-producing Enterobacteriaceae (CPE) have increased during the last years. This study analyses CPE trends at a tertiary hospital in Spain from 2021 to 2023, aiming to optimize personalized medicine. Methods: CPE isolates were the first isolate per patient, year, species, and carbapenemase from January 2021 to December 2023. Additional metadata were collected from the laboratory's information system. Antibiotic susceptibility testing was performed by broth microdilution. Whole-genome sequencing (WGS) was performed using Illumina short reads. De novo assembly was used to generate draft genomes in order to determine their complete taxonomic classification, resistome, plasmidome, sequence type (ST), core-genome multilocus sequence typing (cgMLST), and phylogenetic relationships using a suite of bioinformatics tools and in-house scripts. Results: Between 2021 and 2023, 0.4% out of 38,145 Enterobacteriaceae isolates were CPE. The CPE rate tripled in 2022 and doubled again in 2023. The most common species was Klebsiella pneumoniae (51.8%) and the most common carbapenemase was blaOXA-48. WGS revealed concordant species identification and the carbapenemase distribution in detail. Resistance rates to critical antibiotics, such as carbapenems, were variable, but in most cases were above 70%. Genetic diversity was observed in WGS and phylogenetic analyses, with plasmids often mediating carbapenemase dissemination. Conclusions: The increasing rate of CPE in healthcare settings highlights a critical public health challenge, with limited treatment options. Genomic characterization is essential to understanding resistance mechanisms, aiding therapy, limiting outbreaks, and improving precision medicine.

Antibiotic Resistance in Fermented Foods Chain: Evaluating the Risks of Emergence of Enterococci as an Emerging Pathogen in Raw Milk Cheese

Fermented foods, particularly fermented dairy products, offer significant health benefits but also present serious concerns. Probiotic bacteria, such as lactic acid bacteria (LAB), found in these foods have been strongly linked to the selection and dissemination of antibiotic resistance genes (ARGs). This study aims to examine the potential risks associated with fermented foods, despite their importance in human nutrition, by analyzing the entire production chain from raw material acquisition to storage. Focusing on cheese production as a key fermented food, the study will investigate various aspects, including dairy farm management, milk acquisition, milk handling, and the application of good manufacturing practices (GMP) and good hygiene practices (GHP) in cheese production. The findings of this review highlight that ARGs found in LAB are similar to those observed in hygiene indicator bacteria like E. coli and pathogens like S. aureus. The deliberate use of antibiotics in dairy farms and the incorrect use of disinfectants in cheese factories contribute to the prevalence of antibiotic-resistant bacteria in cheeses. Cheese factories, with their high frequency of horizontal gene transfer, are environments where the microbiological diversity of raw milk can enhance ARG transfer. The interaction between the raw milk microbiota and other environmental microbiotas, facilitated by cross-contamination, increases metabolic communication between bacteria, further promoting ARG transfer. Understanding these bacterial and ARG interactions is crucial to ensure food safety for consumers.

Decoding the enigma: unveiling the transmission characteristics of waterfowl-associated bla NDM-5-positive Escherichia coli in select regions of China

Escherichia coli (E. coli) serves as a critical indicator microorganism for assessing the prevalence and dissemination of antibiotic resistance, notably harboring various antibiotic-resistant genes (ARGs). Among these, the emergence of the bla NDM gene represents a significant threat to public health, especially since carbapenem antibiotics are vital for treating severe infections caused by Gram-negative bacteria. This study aimed to characterize the antibiotic resistance features of bla NDM-5-positive E. coli strains isolated from waterfowl in several regions of China and elucidate the dissemination patterns of the bla NDM-5 gene. We successfully isolated 103 bla NDM-5-positive E. coli strains from 431 intestinal fecal samples obtained from waterfowl across five provincial-level units in China, with all strains exhibiting multidrug resistance (MDR). Notably, the bla NDM-5 gene was identified on plasmids, which facilitate efficient and stable horizontal gene transfer (HGT). Our adaptability assays indicated that while the bla NDM-5-positive plasmid imposed a fitness cost on the host bacteria, the NDM-5 protein was successfully induced and purified, exhibiting significant enzymatic activity. One strain, designated DY51, exhibited a minimum inhibitory concentration (MIC) for imipenem of 4 mg/L, which escalated to 512 mg/L following exposure to increasing imipenem doses. This altered strain demonstrated stable resistance to imipenem alongside improved adaptability, correlating with elevated relative expression levels of the bla NDM-5 and overexpression of efflux pumps. Collectively, this study highlights the horizontal dissemination of the bla NDM-5 plasmid among E. coli strains, confirms the associated fitness costs, and provides insights into the mechanisms underlying the stable increase in antibiotic resistance to imipenem. These findings offer a theoretical framework for understanding the dissemination dynamics of bla NDM-5 in E. coli, which is essential for developing effective strategies to combat carbapenem antibiotic resistance.

Assessing the efficacy of carbon nanodots derived from curcumin on infectious diseases

INTRODUCTION

The threat of new, emerging, and multidrug-resistant microbes is increasing which has created the necessity for new antimicrobials. In this regard, nanotechnology can be an alternative for the treatment of infectious microbes. Curcumin has been used since ancient times as antimicrobials; however, it has limitations due to its less aqueous solubility, bioavailability, and biocompatibility. This problem can be solved by curcumin-derived carbon nanodots, which are emerging antimicrobials of <10 nm size, water-soluble, biocompatible, less toxic, and fluorescent.

AREAS COVERED

The review discusses the application of curcumin-derived carbon nanodots against various pathogenic microbes including bacteria and dreaded viruses like SARS-CoV-2. In addition, the role of curcumin carbon nanodots in biolabelling of pathogenic microbes, mechanism of action, bioimaging, and therapy has been critically examined.

EXPERT OPINION

Carbon nanodots play an important role in combating pathogenic microbes by early diagnosis, bioimaging, nanocarrier for antimicrobial drugs, and therapy of infectious diseases. Curcumin carbon nanodots have already demonstrated their benefits of being water soluble, bioavailable, and biocompatible. However, more thorough research is needed to understand the efficacy and safety of curcumin carbon nanodots. In the future, curcumin-derived carbon nanodots can be used as alternative antimicrobial agents to fight microbial infections including multidrug-resistant microbes.

Profiling the bacterial microbiome diversity and assessing the potential to detect antimicrobial resistance bacteria in wastewater in Kimberley, South Africa

Wastewater treatment plants (WWTPs) are hotspots for pathogens, and can facilitate horizontal gene transfer, potentially releasing harmful genetic material and antimicrobial resistance genes into the environment. Little information exists on the composition and behavior of microbes in WWTPs, especially in developing countries. This study used environmental DNA (eDNA) techniques to examine the microbiome load of wastewater from WWTPs. The DNA was isolated from wastewater samples collected from the treatment trains of three WWTPs in Kimberley, South Africa, and the microbial diversity and composition was compared through 16 S rRNA gene sequencing. The microbes detected were of the Kingdom Bacteria, and of these, 48.27% were successfully identified to genus level. The majority of reads from the combined bacterial data fall within the class Gammaproteobacteria, which is known to adversely impact ecological and human health. Arcobacteraceae constituted 19% of the bacterial reads, which is expected as this family is widespread in aquatic environments. Interestingly, the most abundant bacterial group was Bacteroides, which contain a variety of antibiotic-resistant members. Overall, various antibiotic-resistant taxa were detected in the wastewater, indicating a concerning level of antibiotic resistance within the bacterial community. Therefore, eDNA analysis can be a valuable tool in monitoring and assessing the bacterial microbiome in wastewater, thus providing important information for the optimization and improvement of wastewater treatment systems and mitigate public health risks.

Molecular characterization of Staphylococcus aureus from nasal samples of healthy pet cats

The objective of this study was to characterize Staphylococcus aureus isolates recovered from the nasal samples of healthy pet cats in Algiers province. A total of 138 nasal swabs were collected. Antimicrobial susceptibility was conducted using the disk-diffusion method and the VITEK-2 susceptibility system. Whole genome sequencing was performed to identify multiple-locus sequence typing, antimicrobial and virulence genes. Staphylococcus aureus isolates were detected in 23 cats. Among these, 11 were methicillin-resistant S. aureus (MRSA) (one isolate/sample). Three sequence types (ST6, ST5, and ST1) were identified in MRSA, with the predominance of ST6 (n = 7). Seven distinct STs [ST398, ST97, ST15, ST7, ST291, ST5043, and a new ST, (ST9219)] were detected in methicillin-sensitive S. aureus. All MRSA isolates harbored the mecA gene and SCCmec-type-IVa. MRSA exhibited resistance to tetracycline [n = 3/tet(L) and tet(M); n = 1/tet(K)], kanamycin-tobramycin [n = 3/ant(4')-Ia), amikacin-kanamycin (n = 1/aph(3')-IIIa], and erythromycin-clindamycin [n = 1/erm(C)]. Seven S. aureus isolates were multidrug resistant. All the isolates were negative for lukS/lukF-PV and tst-1 genes, while 20 isolates were IEC-positive. This study revealed a diversity of genetic lineages in S. aureus strains isolated from nasal samples of pet cats, including multidrug-resistant and toxigenic strains. The presence of IEC-positive S. aureus suggests possible human-animal transmission.

Synergistic Antibacterial Effect of Eisenia bicyclis Extracts in Combination with Antibiotics against Fish Pathogenic Bacteria

The aquaculture industry faces significant challenges due to bacterial infections caused by Edwardsiella tarda, Photobacterium damselae, and Vibrio harveyi. The extensive use of traditional antibiotics, has resulted in widespread antibiotic resistance. This study aimed to investigate the antibacterial potential of the brown seaweed Eisenia bicyclis, particularly its synergistic effects with antibiotics against these fish pathogenic bacteria. E. bicyclis were processed to obtain methanolic extracts and fractionated using different polar solvents. The antibacterial activities of these extracts and fractions were assessed through disc diffusion and minimum inhibitory concentration (MIC) assays. The study further evaluated the antibiotic susceptibility of the bacterial strains and the synergistic effects of the extracts combined with erythromycin and oxyteteracycline using the fractional inhibitory concentration index. Results showed that the ethyl acetate (EtOAc) fraction of E. bicyclis methanolic extract exhibited the highest antibacterial activity. The combination of the EtOAc fraction with erythromycin significantly enhanced its antibacterial efficacy against the tested strains. This synergistic effect was indicated by a notable reduction in MIC values, demonstrating the potential of E. bicyclis to enhance the effectiveness of traditional antibiotics. The findings suggest that E. bicyclis extracts, particularly the EtOAc fraction, could serve as a potent natural resource to counteract antibiotic resistance in aquaculture.

Impact of improper municipal solid waste management on fostering One Health approach in Ethiopia - challenges and opportunities: A systematic review

Improper disposal of solid waste, predominantly illegal dumping, can lead to severe air and water pollution, land degradation, climate change, and health hazards due to the persistence of hazardous materials. As a result, it is threatening public and animal health, environmental sustainability, and economic development. The One Health approach, which acknowledges the interconnectedness of human, animal, and environmental health, offers a comprehensive solution. This systematic review examines the impact of improper municipal solid waste on fostering One Health approaches at the national level of Ethiopia by identifying key challenges and opportunities. Publications were retrieved from peer-reviewed, indexed journal publications, government documents (policies, proclamations, regulations, and guidelines), and credible non-governmental organization publications from selected electronic databases (Google scholar, PubMed, EMBASE, Global Health, Web of Science, etc.), and governmental offices. Despite efforts to advance the One Health approach in Ethiopia through the formation of the National One Health Steering Committee and technical working groups, implementation is hindered by challenges such as poor sectoral integration, insufficient advocacy, financial constraints, and limited research. These challenges contribute to worsening zoonotic and infectious diseases and environmental issues due to inadequate solid waste management. Nonetheless, opportunities exist through One Health integration via holistic programs, interdisciplinary collaboration, community engagement, policy enhancement, institutional capacity building, and public-private partnerships. Therefore, enhancing sectoral integration and increasing advocacy efforts and securing financial support is necessary to back waste management initiatives and related research. Further research is crucial to understand the impact of solid waste management and the potential benefits of the One Health approach in Ethiopia.

Biosynthesis of antimicrobial nanoparticle from Swertia spp. (Chirayita) against bacterial pathogens of poultry- A way forward to green nanotechnology and nano-medicines

The increasing prevalence of multidrug-resistant microorganisms in poultry has led to a rise in bacterial infections, causing significant economic loss. Green nanotechnology, such as silver nanoparticles (AgNPs), has the potential to address this issue by providing potent antifungal, antiviral, and antibacterial properties. This study explored the combined potential of AgNPs and the local herb Swertia chirayita against established poultry pathogens, employing a non-factorial Central Composite Design (CCD) to evaluate the factors affecting the production of nanoparticles induced by silver nitrate from the selected herb. The optimal values for temperature, wavelength, silver nitrate concentration, incubation duration, and pH were found to produce the highest nanoparticles. The functional groups in Swertia chirayita stimulated nanoparticles were confirmed using FTIR spectroscopy, and the stability of ScNPs was elucidated using zeta potential. The crystalline structure of ScNPs was confirmed using diffraction intensity patterns. Silver nanoparticles demonstrated antibacterial activity against Salmonella spp. and Escherichia coli (E.coli), both known as significant poultry pathogens, using the agar well diffusion method, with inhibition zones of 25.0 mm and 35.0 mm, respectively.This study explored the green manufacturing of silver nanoparticles by using plants and microorganisms, focusing on their antibacterial properties. The exact mechanism of synthesis and action in AgNPs is still poorly understood. Researchers should prioritize the use of accessible, easy-to-extract plants or bacteria, especially non-pathogenic and fast-growing microorganisms for safe handling. Analyzing biomolecules in plant extract, microbial biomass, or culture supernatants, including probiotic bacteria, is crucial for creating and stabilizing AgNPs, which could be effective synthetic agents. It is crucial to optimize conditions for rapid, stable, and large-scale synthesis. Based on this research, Sc-NPs may be proposed as nanomedicine for treating infections in poultry caused by E. coli and Salmonella spp.

Alginate/organo-selenium composite hydrogel beads: Dye adsorption and bacterial deactivation

Post-COVID-19, the risk and spread of germs, coupled with wastewater contamination, have become critical concerns. Wastewater contains waterborne bacteria and various contaminants like dye molecules, threatening water safety. Traditional adsorption methods address pollutant removal or pathogen inactivation separately, but a dual-action solution is increasingly essential. This study presents alginate/selenium composite hydrogel beads with the potential to simultaneously remove dyes and deactivating bacteria. Fabricated by dropping suspension droplets into a calcium ion bath, these beads were tested for dye adsorption and antibacterial efficacy. Beads with 50 wt% organo‑selenium demonstrated the highest methylene blue (MB) adsorption capacity and nearly 100 % deactivation efficiency against Pseudomonas aeruginosa, while those with 20 wt% showed no significant improvement. Mechanistic studies reveal that organo‑selenium induces stacking effects and reduces surface charges, enhancing MB adsorption and antibacterial performance. The alginate/organo‑selenium composite hydrogel beads offer a potential effective and sustainable solution for tackling the complex issue of wastewater pollutants.

Seasonal dynamics of antibiotic resistance genes and mobile genetic elements in a subtropical coastal ecosystem: Implications for environmental health risks

Antibiotic resistance poses a considerable global public health concern, leading to heightened rates of illness and mortality. However, the impact of seasonal variations and environmental factors on the health risks associated with antibiotic resistance genes (ARGs) and their assembly mechanisms is not fully understood. Based on metagenomic sequencing, this study investigated the antibiotic resistome, mobile genetic elements (MGEs), and microbiomes in a subtropical coastal ecosystem of the Beibu Gulf, China, over autumn and winter, and explored the factors influencing seasonal changes in ARG and MGE abundance and diversity. Results indicated that ARG abundance and diversity were higher in winter than in autumn, with beta-lactam and multidrug resistance genes being the most diverse and abundant, respectively. Similarly, MGE abundance and diversity increased in winter and were strongly correlated with ARGs. In contrast, more pronounced associations between microbial communities, especially archaea, and the antibiotic resistome were observed in autumn than in winter. The co-occurrence network identified multiple interactions between MGEs and various multidrug efflux pumps in winter, suggesting a potential for ARG dissemination. Multivariate correlation analyses and path modeling indicated that environmental factors driving microbial community changes predominantly influenced antibiotic resistome assembly in autumn, while the relative importance of MGEs increased significantly in winter. These findings suggest an elevated health risk associated with antimicrobial resistance in the Beibu Gulf during winter, attributed to the dissemination of ARGs by horizontal gene transfer. The observed seasonal variations highlight the dynamic nature of antibiotic resistance dissemination in coastal ecosystems, emphasizing the need for comprehensive surveillance and management measures to address the growing threat of antimicrobial resistance in vulnerable environments.

Terpenoids from Marine Sources: A Promising Avenue for New Antimicrobial Drugs

Currently, there is an urgent need for new antibacterial and antifungal agents to combat the growing challenge of antibiotic resistance. As the largest ecosystem on Earth, the marine ecosystem includes a vast array of microorganisms (primarily bacteria and fungi), plants, invertebrates, and vertebrates, making it a rich source of various antimicrobial compounds. Notably, terpenoids, known for their complex structures and diverse bioactivities, are a significant and promising group of compounds in the battle against bacterial and fungal infections. In the past five years, numerous antimicrobial terpenoids have been identified from marine organisms such as bacteria, fungi, algae, corals, sea cucumbers, and sponges. This review article provides a detailed overview of 141 terpenoids with antibacterial and/or antifungal properties derived from marine organisms between 2019 and 2024. Terpenoids, a diverse group of natural organic compounds derived from isoprene units, are systematically categorized based on their carbon skeleton structures. Comprehensive information is provided about their names, structures, biological sources, and the extent of their antibacterial and/or antifungal effectiveness. This review aims to facilitate the rapid identification and development of prospective antimicrobials in the pharmaceutical sector.

Ratanjot (Alkanna tinctoria L.) Root Extract, Rich in Antioxidants, Exhibits Strong Antimicrobial Activity against Foodborne Pathogens and Is a Potential Food Preservative

Natural and sustainable plant-based antioxidants and antimicrobials are highly desirable for improving food quality and safety. The present investigation assessed the antimicrobial and antioxidant properties of active components from Alkanna tinctoria L. (herb) roots, also known as Ratanjot root. Two methods were used to extract active components: microwave-assisted hot water (MAHW) and ethanolic extraction. MAHW extract yielded 6.29%, while the ethanol extract yielded 18.27%, suggesting superior Ratanjot root extract powder (RRP) solubility in ethanol over water. The ethanol extract showed significantly higher antioxidant activity than the MAHW extract. Gas Chromatography-Mass Spectrometry analysis revealed three major phenolic compounds: butanoic acid, 3-hydroxy-3-methyl-; arnebin 7, and diisooctyl pthalate. The color attributes (L*, a*, b*, H°ab, C*ab) for the ethanolic and MAHW extracts revealed significant differences (p < 0.05) in all the above parameters for both types of extracts, except for yellowness (b*) and chroma (C*ab) values. The ethanol extract exhibited antimicrobial activity against 14 foodborne bacteria, with a significantly higher inhibitory effect against Gram-positive bacteria (Listeria monocytogenes and Staphylococcus aureus) than the Gram-negative bacteria (Salmonella enterica serovar Typhimurium and Escherichia coli). The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were both 25 mg/mL for the Gram-negative bacteria, while the MIC and MBC concentrations varied for Gram-positive bacteria (0.049-0.098 mg/mL and 0.098-0.195 mg/mL) and the antimicrobial effect was bactericidal. The antimicrobial activities of RRP extract remained stable under broad temperature (37-100 °C) and pH (2-6) conditions, as well as during refrigerated storage for 30 days. Application of RRP at 1% (10 mg/g) and 2.5% (25 mg/g) levels in a cooked chicken meatball model system prevented lipid oxidation and improved sensory attributes and retarded microbial growth during refrigerated (4 °C) storage for 20 days. Furthermore, the RRP extract was non-toxic when tested with sheep erythrocytes and did not inhibit the growth of probiotics, Lacticaseibacillus casei, and Lactiplantibacillus plantarum. In conclusion, the study suggests that RRP possesses excellent antimicrobial and antioxidant activities, thus making it suitable for food preservation.

Mass spectrometry-based metabolomics for the investigation of antibiotic-bacterial interactions

With the development of analytical technologies especially mass spectrometry, metabolomics is becoming increasingly hot in the field of studying antibiotic-bacterial interactions. On the one hand, metabolomics can reveal metabolic perturbations in bacteria in the presence of antibiotics and expose metabolic mechanisms. On the other hand, through in-depth analysis of bacterial metabolic profiles, biomarkers and bioactive secondary metabolites with great potential as drug precursors can be discovered. This review focuses on the experimental workflow of bacterial metabolomics and its application to study the interaction between bacteria and antibiotics. Metabolomics improves the understanding of antibiotic lethality, reveals metabolic perturbations in antibiotic-resistant bacteria, guides the diagnosis and antibiotic treatment of infectious diseases, and aids in the exploration of antibacterial metabolites in nature. Furthermore, current limitations and directions for future developments in this area are discussed.

High Prevalence of Colistin-Resistant Encoding Genes Carriage among Patients and Healthy Residents in Vietnam

Background and Objectives: We aimed to investigate the carriage of colistin-resistant genes among both patients with a history of antibiotic exposure and apparently healthy adults with no recent healthcare contact. Materials and Methods: Stool swabs were collected from healthy people, and specimens were collected at the infection foci from the patients. Eleven primer/probe sets were used to perform the Multiplex Real-Time PCR assay with the QuantiNova Multiplex Probe PCR kit for screening the carriage of colistin-resistant genes (mcr-1 to mcr-10) and 16S rRNA gene as internal control. Results: In total, 86 patients and 96 healthy residents were included. Twenty two patients (25.9%) were positive with at least one colistin-resistance encoding gene. The mcr-1 gene was the most frequent (16.5%), followed by mcr-9, mcr-6, and mcr-4 genes, where the prevalence was 11.8%, 10.6%, and 9.4%, respectively. No patient was positive with mcr-3, mcr-7, and mcr-8 genes. Eight patients (9.4%) were positive with multiple colistin-encoding genes. Twenty-three healthy people (24.0%) were positive with at least one colistin-resistance encoding gene, and the mcr-10 gene was the most frequent (27.0%), followed by the mcr-1, mcr-8, and mcr-9 genes, where the prevalence was 24.3%, 21.6%, and 13.5%, respectively. No person was positive with the mcr-2 and mcr-5 genes. Conclusions: Our findings underscore the urgent need for enhanced surveillance, infection control measures, and stewardship interventions to mitigate the spread of colistin resistance in Vietnam.

Editorial for the Special Issue "Antibacterial Activity of Drug-Resistant Strains"

Antimicrobial resistance is an urgent global public health threat, as approximately 700,000 deaths annually can be attributed to antibiotic-resistant bacterial infections, and this figure is expected to reach 10 million deaths/year by 2050, a number that greatly exceeds the number of deaths resulting from cancer [...].