Antibiotics in agriculture and the risk to human health: how worried should we be?

Graduate Student Literature Review: Perceptions of biosecurity in a Canadian dairy context

The objective of this review was to outline current implementation of biosecurity, the impact of biosecurity on the industry, and producers' and veterinarians' perceptions of biosecurity, with a focus on the Canadian dairy industry. Biosecurity has an important role in farm safety by reducing the spread of pathogens and contaminants, improving animal health and production, and maintaining human safety. Implementation of biosecurity practices varies among farms and countries. Because Canada's supply management system is different than other countries, different barriers and perceptions of biosecurity may exist. Producers may have negative perspectives on biosecurity, such as it being expensive or time consuming. Producers are motivated or deterred from biosecurity implementation for many reasons, including perceived value, disease risk, and financial incentives or deterrents. In addition, because veterinarians are a trusted source of information, their approaches to discussions on biosecurity implementation are important to understand. Veterinarians and producers appear to have differing opinions on the importance of biosecurity and approaches to discussing biosecurity. Improving biosecurity implementation requires a multifactorial approach, such as individualized education and awareness for producers, further research into efficacy of and barriers to biosecurity, and development of strategies for effective communication between veterinarians and producers.

Effects of hydrothermal treatment on the reduction of antibiotic-resistant Escherichia coli and antibiotic resistance genes and the fertilizer potential of liquid product from cattle manure

In this study, the reduction in the abundance of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) and the fertilizer potential of liquid products from hydrothermally treated cattle manure were investigated. Hydrothermal treatment (HTT) was conducted under different reaction temperatures (125, 150, 175 and 200 °C) and retention times (60, 90 and 120 min). The total organic carbon (TOC) and total nitrogen (TN) of the liquid product increased with increasing reaction temperature. The germination index (GI), a measure of the percentage of germination, exceeded 90 % at 125, 150, and 175 °C in diluted samples, while it decreased to 18 % at 200 °C. Although a longer retention time contributed to an increase in TOC of liquid products, it did not increase the GI values. The liquid product should be diluted or adjusted before use as fertilizer to prevent phytotoxicity. In our analysis of ARB and ARGs, E. coli and antibiotic-resistant E. coli were completely reduced after HTT, except for the operating conditions of 125 °C and 60 min. Although both a higher reaction temperature and longer retention time tended to be better for the reduction of ARGs and intI1, it was found that the longer retention time is much more effective than the higher reaction temperature. The reduction of target ARGs and intI1 was 2.9-log under175 °C and 120 min. Comprehensively considering the fertilizer potential of liquid product and the reduction of ARB and ARGs, 175 °C of reaction temperature and 120 min of retention time of operating conditions for HTT were recommended.

Effect of lipopolysaccharides from pathogenic bacteria on broiler chickens' productivity: a meta-analysis

1. This meta-analysis investigated the impact of LPS and covariates (serotype, rearing period and administration route) on the productivity parameters of broiler chickens (average daily feed intake (ADFI), average daily gain (ADG) and feed conversion ratio (FCR)).2. Thirty-two eligible studies were included. Hedges' g effect size was determined using a random-effects model at 95% confidence interval.3. Results showed that LPS significantly decreased average daily feed intake (ADFI; p < 0.0001) and average daily gain (ADG; p < 0.0001) and increased FCR (p < 0.0001). The serotypes Escherichia coli 055: B5 (EC055: B5) and Escherichia coli 0127: B8 (EC 0127: B8) significantly reduced ADFI and ADG, and the serotype EC 055: B5 significantly increased the FCR (p < 0.05).4. The intraperitoneal administration of the LPS significantly reduced the productivity of broiler chickens (p < 0.05), but other administration routes did not show such effects. The reduction in ADFI and ADG was found in all rearing periods (p < 0.05), and the increase in FCR was observed in the starter (p = 0.0302) and grower periods (p = 0.0031).5. Exposure to LPS significantly reduced the productivity of broiler chickens (p < 0.05). However, no relationship was observed between LPS dosage and productivity as indicated by the meta-regression study.6. The findings indicated that LPS has detrimental effects on broiler chickens' ADFI, ADG and FCR across various LPS serotypes and rearing periods. These detrimental impacts of LPS remain consistent regardless of the administered dosage.

Economic assessment of an intervention strategy to reduce antimicrobial usage in small-scale chicken farms in Vietnam

Antimicrobials are a core aspect of most livestock production systems, especially in low-and middle-income countries. They underpin the efficient use of scarce feed resources and stabilize returns on capital and labor inputs. Antimicrobial use (AMU) contributes to the production of healthy animals, yet AMU in livestock is linked to antimicrobial resistance (AMR) in animals, humans and the environment. The Vietnamese Platform for Antimicrobial Reduction in Chicken Production was implemented during 2016-2019 and was one of Southeast Asia's first interventions focused on AMU reductions in livestock production. The project targeted small-scale commercial poultry farms in the Mekong Delta region of Vietnam using a "randomized before-and-after controlled" study design. It provided farmers with a locally adapted support service (farmer training plan, advisory visits, biosecurity, and antimicrobial replacement products) to help them reduce their reliance on antimicrobials. A partial budget analysis was performed comparing the control group (status-quo) and intervention group (alternative). The median net farm-level benefit of the intervention strategies with the project's support was VND 6.78 million (interquartile range (IR) VND -71.9-89 million) per farm. Without project support the benefit was reduced to VND 5.1 million (IR VND -69.1-87.2 million) to VND 5.3 million (IR -VND 68.9-87.5 million) depending on the antimicrobial alternative product used. At the project level with a focus on AMU and its reduction, subsequently influence on the resistance reduction, our results showed that achieving resistance reduction benefits with the current knowledge and technologies required investment of at least VND 9.1 million (US$ 395.10) per farm during the project's lifetime. The results highlight the positive net profit for the majority of enrolled farms and a reasonable investments from the project. The recommendation focuses on the implementation of policies on financial support, legislation, and information as potential solutions to facilitate the application of intervention strategies to reduce AMU in poultry production.

A metagenomic study of antibiotic resistance genes in a hypereutrophic subtropical lake contaminated by anthropogenic sources

Antibiotic resistance genes (ARGs) are a major threat to human and environmental health. This study investigated the occurrence and distribution of ARGs in Lake Cajititlán, a hypereutrophic subtropical lake in Mexico contaminated by anthropogenic sources (urban wastewater and runoff from crop and livestock production). ARGs (a total of 475 genes) were detected in 22 bacterial genera, with Pseudomonas (144 genes), Stenotrophomonas (88 genes), Mycobacterium (54 genes), and Rhodococcus (27 genes) displaying the highest frequencies of ARGs. Among these, Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed the highest number of ARGs. The results revealed a diverse array of ARGs, including resistance to macrolides (11.55 %), aminoglycosides (8.22 %), glycopeptides (6.22 %), tetracyclines (4 %), sulfonamides (4 %), carbapenems (1.11 %), phenicols (0.88 %), fluoroquinolones (0.44 %), and lincosamides (0.22 %). The most frequently observed ARGs were associated with multidrug resistance (63.33 %), with MexF (42 genes), MexW (36 genes), smeD (31 genes), mtrA (25 genes), and KHM-1 (22 genes) being the most common. Lake Cajititlán is a recreational area for swimming, fishing, and boating, while also supporting irrigation for agriculture and potentially acting as a drinking water source for some communities. This raises concerns about the potential for exposure to antibiotic-resistant bacteria through these activities. The presence of ARGs in Lake Cajititlán poses a significant threat to both human and environmental health. Developing strategies to mitigate the risks of antibiotic resistance, including improving wastewater treatment, and promoting strategic antibiotic use and disposal, is crucial. This study represents a significant advancement in the understanding of antibiotic resistance dynamics in a hypereutrophic subtropical lake in a developing country, providing valuable insights for the scientific community and policymakers.

Isolation of a CTX-M-55 (ESBL)-Producing Escherichia coli Strain of the Global ST6448 Clone from a Captive Orangutan in the USA

The purpose of this study was to determine if orangutans (Pongo spp.) living in captivity at a zoo in Wisconsin were colonized with antimicrobial-resistant bacteria and, if found, to identify underlying genetic mechanisms contributing to their resistant phenotypes. We hypothesize that since antimicrobial-resistant bacteria are so prevalent within humans, the animals could also be carriers of such strains given the daily contact between the animals and the zoo staff that care for them. To test this theory, fecal samples from two orangutans were examined for resistant bacteria by inoculation on HardyCHROM™ ESBL and HardyCHROM™ CRE agars. Isolates were identified using MALDI-TOF mass spectrometry and antimicrobial susceptibility testing was performed using a Microscan autoSCAN-4 System. An isolate was selected for additional characterization, including whole genome sequencing (WGS). Using the Type (Strain) Genome Server (TYGS) the bacterium was identified as Escherichia coli. The sequence type identified was (ST/phylogenetic group/β-lactamase): ST6448/B1/CTX-M-55.

A Study of the Synergistic Effects of Essential Oils from Origanum compactum and Origanum elongatum with Commercial Antibiotics against Highly Prioritized Multidrug-Resistant Bacteria for the World Health Organization

The irrational use of antibiotics has favored the emergence of resistant bacteria, posing a serious threat to global health. To counteract antibiotic resistance, this research seeks to identify novel antimicrobials derived from essential oils that operate through several mechanisms. It aims to evaluate the quality and composition of essential oils from Origanum compactum and Origanum elongatum; test their antimicrobial activity against various strains; explore their synergies with commercial antibiotics; predict the efficacy, toxicity, and stability of compounds; and understand their molecular interactions through docking and dynamic simulations. The essential oils were extracted via hydrodistillation from the flowering tops of oregano in the Middle Atlas Mountains in Morocco. Gas chromatography combined with mass spectrometry (GC-MS) was used to examine their composition. Nine common antibiotics were chosen and tested alone or in combination with essential oils to discover synergistic effects against clinically important and resistant bacterial strains. A comprehensive in silico study was conducted, involving molecular docking and molecular dynamics simulations (MD). O. elongatum oil includes borneol (8.58%), p-cymene (42.56%), thymol (28.43%), and carvacrol (30.89%), whereas O. compactum oil is mostly composed of γ-terpinene (22.89%), p-cymene (15.84%), thymol (10.21%), and (E)-caryophyllene (3.63%). With O. compactum proving to be the most potent, these essential oils showed antibacterial action against both Gram-positive and Gram-negative bacteria. Certain antibiotics, including ciprofloxacin, ceftriaxone, amoxicillin, and ampicillin, have been shown to elicit synergistic effects. To fight resistant bacteria, the essential oils of O. compactum and O. elongatum, particularly those high in thymol and (E)-caryophyllene, seem promising when combined with antibiotics. These synergistic effects could result from their ability to target the same bacterial proteins or facilitate access to target sites, as suggested by molecular docking simulations. Molecular dynamics simulations validated the stability of the examined protein-ligand complexes, emphasizing the propensity of substances like thymol and (E)-caryophyllene for particular target proteins, opening the door to potentially effective new therapeutic approaches against pathogens resistant to multiple drugs.

Phylogeny of Transferable Oxazolidinone Resistance Genes and Homologs

Oxazolidinone resistance, especially transmissible resistance, is a major public health concern, and the origin of this resistance mechanism is not yet resolved. This study aims to delve into the phylogenetic origin of the transmissible oxazolidinone resistance mechanisms conferring cross-resistance to other drugs of human and veterinary importance. The amino acid sequences of the five cfr ribosomal methylases and optrA and poxtA were used as queries in searches against 219,549 bacterial proteomes in the NCBI RefSeq database. Hits with >40% amino acid identity and >80% query coverage were aligned, and phylogenetic trees were reconstructed. All five cfr genes yielded highly similar trees, with rlmN housekeeping ribosomal methylases located basal to the sister groups of S-adenosyl-methionine-dependent methyltransferases from various Deltaproteobacteria and Actinomycetia, including antibiotic-producing Streptomyces species, and the monophyletic group of cfr genes. The basal branches of the latter contained paenibacilli and other soil bacteria; they then could be split into the clades [cfr(C):cfr(E)] and [[cfr:cfr(B)]:cfr(D)], always with different Bacillaceae in their stems. Lachnospiraceae were encountered in the basal branches of both optrA and poxtA trees. The ultimate origin of the cfr genes is the rlmN housekeeping ribosomal methylases, which evolved into a suicide-avoiding methylase in antibiotic producers; a soil organism (Lachnospiraceae, Paenibacilli) probably acted as a transfer organism into pathogenic bacteria. In the case of optrA, the porcine pathogenic Streptococcus suis was present in all branches, while the proteins closest to poxtA originated from Clostridia.

Diversity and Antibiotic Resistance of Triticale Seed-Borne Bacteria on the Tibetan Plateau

The Tibetan Plateau is located in southwestern China. It has many important ecological functions, such as biodiversity protection, and is an important grassland agroecosystem in China. With the development of modern agriculture and animal husbandry, antibiotics are widely used to treat humans and livestock, and antibiotics cannot be fully metabolised by both. Antibiotics eventually find their way into the environment, affecting other parts of grassland agroecosystems. Triticale (Triticosecale wittmack) is an artificial hybrid forage that can be used for both grain and forage. This study revealed the diversity of seedborne bacteria in triticale on the Tibetan Plateau and the resistance of the bacteria to nine antibiotics. It identified 37 representative strains and successfully obtained the spliced sequences of 36 strains of the bacteria, which were clustered into 5 phyla and 16 genera. Among them, 18 strains showed resistance to at least one of the 9 antibiotics, and the colony-forming unit (CFU) abundance of antibiotic-resistant bacteria (ARB) accounted for 45.38% of the total samples. Finally, the bacterial motility and biofilm formation ability were measured, and their correlation with bacterial resistance was analysed. The results showed that the bacterial resistance did not have an absolute positive correlation with the motility or biofilm formation ability.

Wastewater-based surveillance as a tool for public health action: SARS-CoV-2 and beyond

Wastewater-based surveillance (WBS) has undergone dramatic advancement in the context of the coronavirus disease 2019 (COVID-19) pandemic. The power and potential of this platform technology were rapidly realized when it became evident that not only did WBS-measured SARS-CoV-2 RNA correlate strongly with COVID-19 clinical disease within monitored populations but also, in fact, it functioned as a leading indicator. Teams from across the globe rapidly innovated novel approaches by which wastewater could be collected from diverse sewersheds ranging from wastewater treatment plants (enabling community-level surveillance) to more granular locations including individual neighborhoods and high-risk buildings such as long-term care facilities (LTCF). Efficient processes enabled SARS-CoV-2 RNA extraction and concentration from the highly dilute wastewater matrix. Molecular and genomic tools to identify, quantify, and characterize SARS-CoV-2 and its various variants were adapted from clinical programs and applied to these mixed environmental systems. Novel data-sharing tools allowed this information to be mobilized and made immediately available to public health and government decision-makers and even the public, enabling evidence-informed decision-making based on local disease dynamics. WBS has since been recognized as a tool of transformative potential, providing near-real-time cost-effective, objective, comprehensive, and inclusive data on the changing prevalence of measured analytes across space and time in populations. However, as a consequence of rapid innovation from hundreds of teams simultaneously, tremendous heterogeneity currently exists in the SARS-CoV-2 WBS literature. This manuscript provides a state-of-the-art review of WBS as established with SARS-CoV-2 and details the current work underway expanding its scope to other infectious disease targets.

Bioinspired silver nanoparticle-based nanocomposites for effective control of plant pathogens: A review

Plant pathogens, including bacteria, fungi, and viruses, pose significant challenges to the farming community due to their extensive diversity, the rapidly evolving phenomenon of multi-drug resistance (MDR), and the limited availability of effective control measures. Amid mounting global pressure, particularly from the World Health Organization, to limit the use of antibiotics in agriculture and livestock management, there is increasing consideration of engineered nanomaterials (ENMs) as promising alternatives for antimicrobial applications. Studies focusing on the application of ENMs in the fight against MDR pathogens are receiving increasing attention, driven by significant losses in agriculture and critical knowledge gaps in this crucial field. In this review, we explore the potential contributions of silver nanoparticles (AgNPs) and their nanocomposites in combating plant diseases, within the emerging interdisciplinary arena of nano-phytopathology. AgNPs and their nanocomposites are increasingly acknowledged as promising countermeasures against plant pathogens, owing to their unique physicochemical characteristics and inherent antimicrobial properties. This review explores recent advancements in engineered nanocomposites, highlights their diverse mechanisms for pathogen control, and draws attention to their potential in antibacterial, antifungal, and antiviral applications. In the discussion, we briefly address three crucial dimensions of combating plant pathogens: green synthesis approaches, toxicity-environmental concerns, and factors influencing antimicrobial efficacy. Finally, we outline recent advancements, existing challenges, and prospects in scholarly research to facilitate the integration of nanotechnology across interdisciplinary fields for more effective treatment and prevention of plant diseases.

Pathogenicity assessment of Arcobacter butzleri isolated from Canadian agricultural surface water

BACKGROUND

Water is considered a source for the transmission of Arcobacter species to both humans and animals. This study was conducted to assess the prevalence, distribution, and pathogenicity of A. butzleri strains, which can potentially pose health risks to humans and animals. Cultures were isolated from surface waters of a mixed-use but predominately agricultural watershed in eastern Ontario, Canada. The detection of antimicrobial resistance (AMR) and virulence-associated genes (VAGs), as well as enterobacterial repetitive intergenic consensus-polymerase chain reaction (ERIC-PCR) assays were performed on 913 A. butzleri strains isolated from 11 agricultural sampling sites.

RESULTS

All strains were resistant to one or more antimicrobial agents, with a high rate of resistance to clindamycin (99%) and chloramphenicol (77%), followed by azithromycin (48%) and nalidixic acid (49%). However, isolates showed a significantly (p < 0.05) high rate of susceptibility to tetracycline (1%), gentamycin (2%), ciprofloxacin (4%), and erythromycin (5%). Of the eight VAGs tested, ciaB, mviN, tlyA, and pldA were detected at high frequency (> 85%) compared to irgA (25%), hecB (19%), hecA (15%), and cj1349 (12%) genes. Co-occurrence analysis showed A. butzleri strains resistant to clindamycin, chloramphenicol, nalidixic acid, and azithromycin were positive for ciaB, tlyA, mviN and pldA VAGs. ERIC-PCR fingerprint analysis revealed high genetic similarity among strains isolated from three sites, and the genotypes were significantly associated with AMR and VAGs results, which highlight their potential environmental ubiquity and potential as pathogenic.

CONCLUSIONS

The study results show that agricultural activities likely contribute to the contamination of A. butzleri in surface water. The findings underscore the importance of farm management practices in controlling the potential spread of A. butzleri and its associated health risks to humans and animals through contaminated water.

Hollow CoZnSe@CN nanocage with enzymatic activity for determination of tetracycline using smartphone platforms and virtual reality revealing

Antibiotic residues in the environment pose a serious threat to ecosystems and human health. Therefore, it is important to develop sensitive and rapid in situ detection methods. In this work, the designed nanozymes, with excellent four enzyme activities, were proved to be constituted of unique hollow nanocage structures (CoZnSe@CN HCs). Based on the peroxidase-like enzymes, a portable colorimetric sensor was constructed for the on-site determination of tetracycline (TC) in real samples. The linear range of TC detection was 0.1-100 μM, and the detection limit was 0.02 μM. At the same time, colorimetric detection and smartphones have also been combined for on-site colorimetric detection of TC. In-depth exploration of the detection mechanism showed that TC could be bound with the material, inhibiting the production of oxidized 3,3',5,5'-tetramethylbenzidine. The sensor was also used for the detection of TC in environmental soil and water samples. This study can provide an intelligent detection method for environmental monitoring.

Microbial transmission in the social microbiome and host health and disease

Although social interactions are known to drive pathogen transmission, the contributions of socially transmissible host-associated mutualists and commensals to host health and disease remain poorly explored. We use the concept of the social microbiome-the microbial metacommunity of a social network of hosts-to analyze the implications of social microbial transmission for host health and disease. We investigate the contributions of socially transmissible microbes to both eco-evolutionary microbiome community processes (colonization resistance, the evolution of virulence, and reactions to ecological disturbance) and microbial transmission-based processes (transmission of microbes with metabolic and immune effects, inter-specific transmission, transmission of antibiotic-resistant microbes, and transmission of viruses). We consider the implications of social microbial transmission for communicable and non-communicable diseases and evaluate the importance of a socially transmissible component underlying canonically non-communicable diseases. The social transmission of mutualists and commensals may play a significant, under-appreciated role in the social determinants of health and may act as a hidden force in social evolution.

Prospects and Challenges of Bacteriophage Substitution for Antibiotics in Livestock and Poultry Production

The overuse and misuse of antibiotics in the livestock and poultry industry has led to the development of multi-drug resistance in animal pathogens, and antibiotic resistance genes (ARGs) in bacteria transfer from animals to humans through the consumption of animal products, posing a serious threat to human health. Therefore, the use of antibiotics in livestock production has been strictly controlled. As a result, bacteriophages have attracted increasing research interest as antibiotic alternatives, since they are natural invaders of bacteria. Numerous studies have shown that dietary bacteriophage supplementation could regulate intestinal microbial composition, enhance mucosal immunity and the physical barrier function of the intestinal tract, and play an important role in maintaining intestinal microecological stability and normal body development of animals. The effect of bacteriophages used in animals is influenced by factors such as species, dose, and duration. However, as a category of mobile genetic elements, the high frequency of gene exchange of bacteriophages also poses risks of transmitting ARGs among bacteria. Hence, we summarized the mechanism and efficacy of bacteriophage therapy, and highlighted the feasibility and challenges of bacteriophage utilization in farm animal production, aiming to provide a reference for the safe and effective application of bacteriophages as an antibiotic alternative in livestock and poultry.

Healthcare commissioners' experience with antibiotic resistance during the COVID-19 pandemic in Saudi Arabia: a qualitative study

Introduction

The occurrence of antibiotic resistance (AR) has become a critical issue during the Novel coronavirus disease 2019 (COVID-19) pandemic. This study explores the experiences of healthcare commissioners with AR during the COVID-19 pandemic, identifies challenges, and provides recommendations for combating AR during pandemics.

Methods

This qualitative study was multi-centered and used a phenomenological approach. Semi-structured interviews were conducted between December 2022 and January 2023 among 11 health commissioners using video calls.

Results

Seven themes emerged from the data, including knowledge of AR and its consequences, the antibiotic prescription system, the future of AR and potential contributory factors, the impact of COVID-19 on AR and their relationship, the experience of AR during the COVID-19 pandemic in healthcare facilities, barriers that prevent the misuse of antibiotics during pandemics, and recommendations regarding antibiotic resistance during pandemics.

Conclusion

The findings of this study could be used to inform policy and practice for government healthcare workers (HCWs) and the public. Furthermore, this study identified the main challenges of AR during the pandemic, and the recommendations of health commissioners were provided accordingly. Such recommendations could be beneficial on a national and international scale to reduce the impact of future pandemics on AR.

Abbreviations

COVID-19: Novel coronavirus disease 2019; AR: Antibiotic Resistance; IPC: Infection prevention and control; MDRO: multi-drug resistant organism; ASP: Antimicrobial Stewardship Program; HCW: Healthcare worker; KSA: Kingdom of Saudi Arabia; WHO: World Health Organization; MOH: Ministry of Health; MOEWA: Ministry of Environment, Water, and Agriculture; AMR: Antimicrobial Resistance; PHCC: Primary Healthcare Center.

Optimizing the formulation of Erwinia bacteriophages for improved UV stability and adsorption on apple leaves

Fire blight is a bacterial disease that affects plants of the Rosaceae family and causes significant economic losses worldwide. Although antibiotics have been used to control the disease, concerns about their environmental impact and the potential to promote antibiotic resistance have arisen. Bacteriophages are being investigated as an alternative to antibiotics; however, their efficacy can be affected by environmental stresses, such as UV radiation. In this study, we optimized the formulation of Erwinia phages to enhance their stability in the field, focusing on improving their UV stability and adsorption using adjuvants. Our results confirmed that 4.5 % polysorbate 80 and kaolin improve phage stability under UV stress, resulting in an 80 % increase in PFU value and improved UV protection efficacy. Adsorption assays also demonstrated that polysorbate 80 and kaolin improved the absorption efficiency, with phages detected in plant for up to two weeks. These findings demonstrate the effectiveness of the auxiliary formulation of Erwinia bacteriophages against environmental stress.

Control of Escherichia coli in Fresh-Cut Mixed Vegetables Using a Combination of Bacteriophage and Carvacrol

The continual emergence of antibiotic-resistant bacteria and the slow development of new antibiotics has driven the resurgent interest in the potential application of bacteriophages as antimicrobial agents in different medical and industrial sectors. In the present study, the potential of combining phage biocontrol and a natural plant compound (carvacrol) in controlling Escherichia coli on fresh-cut mixed vegetable was evaluated. Four coliphages, designated Escherichia phage SUT_E420, Escherichia phage SUT_E520, Escherichia phage SUT_E1520 and Escherichia phage SUT_E1620, were isolated from raw sewage. Biological characterization revealed that all four phages had a latent period of 20-30 min and a burst size ranging from 116 plaque-forming units (PFU)/colony forming units (CFU) to 441 PFU/CFU. The phages effectively inhibited the growth of respective host bacteria in vitro, especially when used at a high multiplicity of infection (MOI). Based on transmission electron microscopy analysis, all phages were classified as tailed phages in the class of Caudoviricetes. Additionally, next generation sequencing indicated that none of the selected coliphages contained genes encoding virulence or antimicrobial resistance factors, highlighting the suitability of isolated phages as biocontrol agents. When a phage cocktail (~109 PFU/mL) was applied alone onto fresh-cut mixed vegetables artificially contaminated with E. coli, no bacteria were recovered from treated samples on Day 0, followed by a gradual increase in the E. coli population after 24 h of incubation at 8 °C. On the other hand, no significant differences (p < 0.05) were observed between treated and non-treated samples in terms of E. coli viable counts when carvacrol at the minimum inhibitory concentration (MIC) of 6.25 μL/mL was applied alone. When a phage cocktail at an MOI of ~1000 and MIC carvacrol were applied in combination, no E. coli were recovered from treated samples on Day 0 and 1, followed by a slight increase in the E. coli population to approximately 1.2-1.3 log CFU/mL after 48 h of incubation at 8 °C. However, total elimination of E. coli was observed in samples treated with a phage cocktail at a higher MOI of ~2000 and carvacrol at MIC, with a reduction of approximately 4 log CFU/mL observed at the end of Day 3. The results obtained in this study highlight the potential of combined treatment involving phage biocontrol and carvacrol as a new alternative method to reduce E. coli contamination in minimally processed ready-to-eat foods.

Consumer Preferences and Attitudes towards Antibiotic Use in Food Animals

Antimicrobial resistance (AMR) is one of the major challenges faced by society, with the real threat of the failure of many medical procedures. Antibiotics are also used in livestock production and provide a potential pathway to increasing AMR. The central challenge involves ensuring animal health and welfare while securing the long-term effectiveness of antibiotics. This paper reports the results of a survey of 5693 respondents from the customer panels of four major UK supermarkets regarding preferences and attitudes towards antibiotic use in food animals, and their perspectives on how the balance between animal welfare and human benefit can be achieved. The results of these surveys are consistent with those from other countries that found that consumers generally have limited knowledge about antibiotic use in agriculture and AMR, with around 50% responding "don't know" to many questions. There was agreement about the benefits of antibiotics outweighing harm, with 40% agreeing that, overall, the use of antibiotics to treat disease in farm animals delivers more benefit than harm. However, 44% neither agreed nor disagreed, indicating a high level of uncertainty and a situation that is potentially unstable. The seriousness of the AMR challenge is such that continued action for the more discriminating use of antibiotics must continue.

Antibiogram Profile and Detection of Resistance Genes in Pseudomonas aeruginosa Recovered from Hospital Wastewater Effluent

The nosocomial pathogen Pseudomonas aeruginosa (P. aeruginosa) is characterized by increased prevalence in hospital wastewater and is a public health concern. Untreated wastewater severely challenges human health when discharged into nearby aquatic ecosystems. The antibiogram profiles and resistance genes of P. aeruginosa were evaluated in this study. Wastewater effluents were obtained from a hospital within a six-month sampling period. After the samples were processed and analysed, P. aeruginosa was identified by polymerase chain reaction (PCR) by amplifying OprI and OprL genes. The Kirby-Bauer diffusion technique was employed to check the susceptibility profiles of P. aeruginosa which were further interpreted using CLSI guidelines. A total of 21 resistance genes were investigated among the isolates. The sum of 81 positive P. aeruginosa were isolated in this study. This study's mean count of Pseudomonas aeruginosa ranged from 2.4 × 105 to 6.5 × 105 CFU/mL. A significant proportion of the isolates were susceptible to imipenem (93%), tobramycin (85%), norfloxacin (85%), aztreonam (70%), ciprofloxacin (51%), meropenem (47%), levofloxacin (43%), and gentamicin (40%). Meanwhile, a low susceptibility was recorded for amikacin and ceftazidime. The overall multiple antibiotics resistance index (MARI) ranged from 0.3 to 0.9, with 75% of the multidrug-resistant isolates. The assessment of β-lactam-resistant genes revealed blaOXA-1 (3.7%) and blaSHV (2.4%). The frequency of carbapenem genes was 6.6% for blaIMP, 6.6% for blaKPC, 6.6% for blaoxa-48, 2.2% for blaNDM-1, 2.2% for blaGES, and 2.2% for blaVIM. Of the aminoglycoside genes screened, 8.6% harboured strA, 11.5% harboured aadA, and 1.5% harboured aph(3)-Ia(aphA1). Only one non-β-lactamase gene (qnrA) was detected, with a prevalence of 4.9%. The findings of this study revealed a high prevalence of multidrug-resistant P. aeruginosa and resistance determinants potentially posing environmental health risks.

The phc Quorum-Sensing System in Ralstonia solanacearum Species Complex

Ralstonia solanacearum species complex (RSSC) strains are devastating plant pathogens distributed worldwide. The primary cell density-dependent gene expression system in RSSC strains is phc quorum sensing (QS). It regulates the expression of about 30% of all genes, including those related to cellular activity, primary and secondary metabolism, pathogenicity, and more. The phc regulatory elements encoded by the phcBSRQ operon and phcA gene play vital roles. RSSC strains use methyl 3-hydroxymyristate (3-OH MAME) or methyl 3-hydroxypalmitate (3-OH PAME) as the QS signal. Each type of RSSC strain has specificity in generating and receiving its QS signal, but their signaling pathways might not differ significantly. In this review, I describe the genetic and biochemical factors involved in QS signal input and the regulatory network and summarize control of the phc QS system, new cell-cell communications, and QS-dependent interactions with soil fungi.

Electrochemical Biosensors for the Detection of Antibiotics in Milk: Recent Trends and Future Perspectives

Antibiotics have emerged as ground-breaking medications for the treatment of infectious diseases, but due to the excessive use of antibiotics, some drugs have developed resistance to microorganisms. Because of their structural complexity, most antibiotics are excreted unchanged, polluting the water, soil, and natural resources. Additionally, food items are being polluted through the widespread use of antibiotics in animal feed. The normal concentrations of antibiotics in environmental samples typically vary from ng to g/L. Antibiotic residues in excess of these values can pose major risks the development of illnesses and infections/diseases. According to estimates, 300 million people will die prematurely in the next three decades (by 2050), and the WHO has proclaimed "antibiotic resistance" to be a severe economic and sociological hazard to public health. Several antibiotics have been recognised as possible environmental pollutants (EMA) and their detection in various matrices such as food, milk, and environmental samples is being investigated. Currently, chromatographic techniques coupled with different detectors (e.g., HPLC, LC-MS) are typically used for antibiotic analysis. Other screening methods include optical methods, ELISA, electrophoresis, biosensors, etc. To minimise the problems associated with antibiotics (i.e., the development of AMR) and the currently available analytical methods, electrochemical platforms have been investigated, and can provide a cost-effective, rapid and portable alternative. Despite the significant progress in this field, further developments are necessary to advance electrochemical sensors, e.g., through the use of multi-functional nanomaterials and advanced (bio)materials to ensure efficient detection, sensitivity, portability, and reliability. This review summarises the use of electrochemical biosensors for the detection of antibiotics in milk/milk products and presents a brief introduction to antibiotics and AMR followed by developments in the field of electrochemical biosensors based on (i) immunosensor, (ii) aptamer (iii) MIP, (iv) enzyme, (v) whole-cell and (vi) direct electrochemical approaches. The role of nanomaterials and sensor fabrication is discussed wherever necessary. Finally, the review discusses the challenges encountered and future perspectives. This review can serve as an insightful source of information, enhancing the awareness of the role of electrochemical biosensors in providing information for the preservation of the health of the public, of animals, and of our environment, globally.

Highly efficient adsorption of antibiotic ciprofloxacin hydrochloride from aqueous solution by diatomite-basic zinc chloride composites

The antibiotic ciprofloxacin (CIP) is used to treat a variety of bacterial infections, yet it poses significant health risks to aquatic environments. While adsorption is a promising technique for CIP removal, current adsorption capacities remain limited. In this study, we introduce a diatomite and basic zinc chloride composite (ZnHC-Dt) prepared using a straightforward deposition method, with the ability to achieve highly efficient ciprofloxacin removal. ZnHC-Dt is characterized using field emission scanning electron microscopy (SEM), X-ray diffraction analysis (XRD), Fourier transform infrared spectroscopy (FTIR), and the Brunauer-Emmett-Teller method (BET). We also assess the zeta potential. The optimized ZnHC-Dt adsorbent, achieved at a mass ratio of 0.45 with ZnHC/(ZnHC+Dt), is adopted with a CIP adsorption capacity of 831.96 mg/g at 25 °C, broad pH adaptability (within 3.0-10.0), rapid adsorption rate (reaching equilibrium in 4 h), and stable performance under Na+ ionic strength. The CIP adsorption process follows pseudo-second-order kinetics and aligns well with the Langmuir adsorption model. The high adsorption capacity of ZnHC-Dt can be attributed to electrostatic attraction, hydrogen bonding, surface complexation, and available adsorption sites. During the desorption process, the CIP removal rate retains 65.33% effectiveness after five cycles. The results suggest that ZnHC-Dt holds significant potential for CIP removal in aqueous solutions.

Joining Forces against Antibiotic Resistance: The One Health Solution

Antibiotic resistance is a significant global health concern that affects both human and animal populations. The One Health approach acknowledges the interconnectedness of human health, animal health, and the environment. It emphasizes the importance of collaboration and coordination across these sectors to tackle complex health challenges such as antibiotic resistance. In the context of One Health, antibiotic resistance refers to the ability of bacteria to withstand the efficacy of antibiotics, rendering them less effective or completely ineffective in treating infections. The emergence and spread of antibiotic-resistant bacteria pose a threat to human and animal health, as well as to the effectiveness of medical treatments and veterinary interventions. In particular, One Health recognizes that antibiotic use in human medicine, animal agriculture, and the environment are interconnected factors contributing to the development and spread of antibiotic resistance. For example, the misuse and overuse of antibiotics in human healthcare, including inappropriate prescribing and patient non-compliance, can contribute to the selection and spread of resistant bacteria. Similarly, the use of antibiotics in livestock production for growth promotion and disease prevention can contribute to the development of antibiotic resistance in animals and subsequent transmission to humans through the food chain. Addressing antibiotic resistance requires a collaborative One Health approach that involves multiple participants, including healthcare professionals, veterinarians, researchers, and policymakers.

The Potential of Bacteriophage-Antibiotic Combination Therapy in Treating Infections with Multidrug-Resistant Bacteria

The growing threat of antibiotic resistance is a significant global health challenge that has intensified in recent years. The burden of antibiotic resistance on public health is augmented due to its multifaceted nature, as well as the slow-paced and limited development of new antibiotics. The threat posed by resistance is now existential in phage therapy, which had long been touted as a promising replacement for antibiotics. Consequently, it is imperative to explore the potential of combination therapies involving antibiotics and phages as a feasible alternative for treating infections with multidrug-resistant bacteria. Although either bacteriophage or antibiotics can potentially treat bacterial infections, they are each fraught with resistance. Combination therapies, however, yielded positive outcomes in most cases; nonetheless, a few combinations did not show any benefit. Combination therapies comprising the synergistic activity of phages and antibiotics and combinations of phages with other treatments such as probiotics hold promise in the treatment of drug-resistant bacterial infections.

Cattle-compost-soil: The transfer of antibiotic resistance in livestock agriculture

Antibiotic resistance is a major global health threat. Agricultural use of antibiotics is considered to be a main contributor to the issue, influencing both animals and humans as defined by the One Health approach. The purpose of the present study was to determine the abundance of antibiotic-resistant bacterial populations and the overall bacterial diversity of cattle farm soils that have been treated with animal manure compost. Soil and manure samples were collected from different sites at Tullimba farm, NSW. Cultures were grown from these samples in the presence of 11 commonly used antibiotics and antibiotic-resistant bacteria (ARB) colonies were identified. Soil and manure bacterial diversity was also determined using 16S ribosomal RNA next-generation sequencing. Results showed that ARB abundance was greatest in fresh manure and significantly lower in composted manure. However, the application of composted manure on paddock soil led to a significant increase in soil ARB abundance. Of the antibiotics tested, the number of ARB in each sample was greatest for antibiotics that inhibited the bacterial cell wall and protein synthesis. Collectively, these results suggest that the transfer of antibiotic resistance from composted animal manure to soil may not be solely mediated through the application of live bacteria and highlight the need for further research into the mechanism of antibiotic resistance transfer.

Application of antimicrobial peptides in plant protection: making use of the overlooked merits

Pathogen infection is one of the major causes of yield loss in the crop field. The rapid increase of antimicrobial resistance in plant pathogens has urged researchers to develop both new pesticides and management strategies for plant protection. The antimicrobial peptides (AMPs) showed potential on eliminating plant pathogenic fungi and bacteria. Here, we first summarize several overlooked advantages and merits of AMPs, which includes the steep dose-response relations, fast killing ability, broad synergism, slow resistance selection. We then discuss the possible application of AMPs for plant protection with above merits, and highlight how AMPs can be incorporated into a more efficient integrated management system that both increases the crop yield and reduce resistance evolution of pathogens.

Evaluating the long-term portrayal of antibiotic resistance in major U.S. newspapers

BACKGROUND

Popular media play a critical role in informing the public about antibiotic resistance, which has remained a health concern for over seven decades. Media attention increases the notoriety of antibiotic resistance and shapes the public's perception of its severity, causes, and solutions. Therefore, it is critical the media accurately portray scientific knowledge that may shape personal and policy responses to antibiotic resistance.

METHODS

We analyzed articles from two major U.S. newspapers, The New York Times and Los Angeles Times, from 1940 to 2019 to assess trends in sentiment and lexicon surrounding antibiotic and antimicrobial resistance.

RESULTS

We observed a gradual increase in the number of relevant articles about resistance, although far fewer than other topics with comparable mortality rates. We found a consistently threatening portrayal of antibiotic resistance as a crisis, reflected in the usage of terms such as "superbug" to refer to some pathogens. Governmental agencies responsible for determining antibiotic usage policies were infrequently mentioned in articles. Blame for resistance was almost exclusively attributed to inappropriate antibiotic use, mainly in animals, rather than appropriate uses of antibiotics.

CONCLUSIONS

Collectively, our results provide insights into how popular media can more accurately inform the public about antibiotic resistance. Potential changes include increasing news coverage, avoiding fear-mongering, and adequately conveying the multiple uses of antibiotics that can potentiate resistance.

Antimicrobial Resistance: A Growing Serious Threat for Global Public Health

Antibiotics are among the most important discoveries of the 20th century, having saved millions of lives from infectious diseases. Microbes have developed acquired antimicrobial resistance (AMR) to many drugs due to high selection pressure from increasing use and misuse of antibiotics over the years. The transmission and acquisition of AMR occur primarily via a human-human interface both within and outside of healthcare facilities. A huge number of interdependent factors related to healthcare and agriculture govern the development of AMR through various drug-resistance mechanisms. The emergence and spread of AMR from the unrestricted use of antimicrobials in livestock feed has been a major contributing factor. The prevalence of antimicrobial-resistant bacteria has attained an incongruous level worldwide and threatens global public health as a silent pandemic, necessitating urgent intervention. Therapeutic options of infections caused by antimicrobial-resistant bacteria are limited, resulting in significant morbidity and mortality with high financial impact. The paucity in discovery and supply of new novel antimicrobials to treat life-threatening infections by resistant pathogens stands in sharp contrast to demand. Immediate interventions to contain AMR include surveillance and monitoring, minimizing over-the-counter antibiotics and antibiotics in food animals, access to quality and affordable medicines, vaccines and diagnostics, and enforcement of legislation. An orchestrated collaborative action within and between multiple national and international organizations is required urgently, otherwise, a postantibiotic era can be a more real possibility than an apocalyptic fantasy for the 21st century. This narrative review highlights on this basis, mechanisms and factors in microbial resistance, and key strategies to combat antimicrobial resistance.

Plasmid permissiveness of wastewater microbiomes can be predicted from 16S rRNA sequences by machine learning

MOTIVATION

Wastewater treatment plants (WWTPs) harbor a dense and diverse microbial community. They constantly receive antimicrobial residues and resistant strains, and therefore provide conditions for horizontal gene transfer (HGT) of antimicrobial resistance (AMR) determinants. This facilitates the transmission of clinically important genes between, e.g. enteric and environmental bacteria, and vice versa. Despite the clinical importance, tools for predicting HGT remain underdeveloped.

RESULTS

In this study, we examined to which extent water cycle microbial community composition, as inferred by partial 16S rRNA gene sequences, can predict plasmid permissiveness, i.e. the ability of cells to receive a plasmid through conjugation, based on data from standardized filter mating assays using fluorescent bio-reporter plasmids. We leveraged a range of machine learning models for predicting the permissiveness for each taxon in the community, representing the range of hosts a plasmid is able to transfer to, for three broad host-range resistance IncP plasmids (pKJK5, pB10, and RP4). Our results indicate that the predicted permissiveness from the best performing model (random forest) showed a moderate-to-strong average correlation of 0.49 for pB10 [95% confidence interval (CI): 0.44-0.55], 0.43 for pKJK5 (0.95% CI: 0.41-0.49), and 0.53 for RP4 (0.95% CI: 0.48-0.57) with the experimental permissiveness in the unseen test dataset. Predictive phylogenetic signals occurred despite the broad host-range nature of these plasmids. Our results provide a framework that contributes to the assessment of the risk of AMR pollution in wastewater systems.

AVAILABILITY AND IMPLEMENTATION

The predictive tool is available as an application at https://github.com/DaneshMoradigaravand/PlasmidPerm.

A Metasurface Plasmonic Analysis Platform Combined with Gold Nanoparticles for Ultrasensitive Quantitative Detection of Small Molecules

Food safety related to drug residues in food has become a widespread public concern. Small-molecule drug residue analysis often relies on mass spectrometry, thin-layer chromatography, or enzyme-linked immunosorbent assays (ELISA). Some of these techniques have limited sensitivity and accuracy, while others are time-consuming, costly, and rely on specialized equipment that requires skilled operation. Therefore, the development of a sensitive, fast, and easy-to-operate biosensor could provide an accessible alternative to conventional small-molecule analysis. Here, we developed a nanocup array-enhanced metasurface plasmon resonance (MetaSPR) chip coupled with gold nanoparticles (AuNPs) (MSPRAN) to detect small molecules. As sulfamethazine drug residues in poultry eggs may cause health issues, we selected this as a model to evaluate the feasibility of using MSPRAN for small-molecule detection. The MSPRAN biosensor employed competitive immunoassay technology for sulfamethazine detection. The limit of detection was calculated as 73 pg/mL, with sensitivity approximately twice that of previously reported detection methods. Additionally, the recovery rate of the biosensor, tested in egg samples, was similar to that measured using ELISA. Overall, this newly developed MSPRAN biosensor platform for small-molecule detection provides fast and reliable results, facile operation, and is relatively cost-effective for application in food safety testing, environmental monitoring, or clinical diagnostics.

A systematic review and meta-analysis of antimicrobial resistance knowledge, attitudes, and practices: Current evidence to build a strong national antimicrobial drug resistance narrative in Ethiopia

Antimicrobial resistance (AMR) is a silent pandemic that has claimed millions of lives, and resulted in long-term disabilities, limited treatment options, and high economic costs associated with the healthcare burden. Given the rising prevalence of AMR, which is expected to pose a challenge to current empirical antibiotic treatment strategies, we sought to summarize the available data on knowledge, attitudes, and practices regarding AMR in Ethiopia. Articles were searched in international electronic databases. Microsoft Excel spreadsheet and STATA software version 16 were used for data extraction and analysis, respectively. The Preferred Reporting Items for Systematic Reviews and Meta-Analysis 2020 checklist was followed. The methodological quality of the studies included was assessed by the Joana Briggs Institute critical appraisal checklists. The random-effect meta-analysis model was used to estimate Der Simonian-Laird's pooled effect. Statistical heterogeneity of the meta-analysis was checked through Higgins and Thompson's I2 statistics and Cochran's Q test. Publication bias was investigated by funnel plots, and the regression-based test of Egger for small study effects with a P value < 0.05 was considered to indicate potential reporting bias. In addition, sensitivity and subgroup meta-analyses were performed. Fourteen studies with a total of 4476 participants met the inclusion criteria. Overall, the pooled prevalence of good AMR knowledge was 51.53% [(95% confidence interval (CI): 37.85, 65.21), I2 = 99.0%, P <0.001]. The pooled prevalence of favorable attitudes and good practices were 63.43% [(95% CI: 42.66, 84.20), I2 = 99.6, P <0.001], and 48.85% [(95% CI: 38.68, 59.01), I2 = 93.1, P <0.001] respectively. In conclusion, there is a significant knowledge and practice gap on AMR among the general public, patients, and livestock producers. As a result, we call for greater educational interventions to raise awareness and build a strong national AMR narrative.

Antifungal activity of a novel synthetic polymer M451 against phytopathogens

Phytopathogenic fungi are the predominant causal agents of plant diseases. Available fungicides have substantial disadvantages, such as being insufficiently effective owing to intrinsic tolerance and the spread of antifungal resistance accumulating in plant tissues, posing a global threat to public health. Therefore, finding a new broad-spectrum fungicide is a challenge to protect plants. We studied the potency of a novel antimicrobial agent, M451, a 1,6-diaminohexane derivative, against different phytopathogenic fungi of the Ascomycota, Oomycota, and Basidiomycota phyla. M451 exhibited significant antifungal activity with EC₅₀ values from 34-145 μg/mL. The minimal fungicidal concentration against Fusarium oxysporum ranged from 4 to 512 μg/mL depending on the exposure times of 5 min to 24 h. M451 has the highest activity and significantly lower exposure times compared to different polyene, azole, and phenylpyrrole antifungals. The conidial germination assay revealed that M451 induced 99 and 97.8% inhibition against F. oxysporum within 5 min of exposure to 5,000 and 500 μg/mL, respectively. Germ tube elongation, spore production, and spore germination were also significantly inhibited by M451 at concentrations of ≥50 μg/mL. Based on the broad spectrum of antifungal effects across different plant pathogens, M451 could be a new chemical fungicide for plant disease management.

Antibiotic resistance in soil-plant systems: A review of the source, dissemination, influence factors, and potential exposure risks

As an emerging environmental contaminant, the widespread of antibiotic resistance has caused a series of environmental issues and human health concerns. A load of antibiotic residues induced by agricultural practices have exerted selective pressure to bacterial communities in the soil-plant system, which facilitated the occurrence and dissemination of antibiotic resistance genes (ARGs) through horizontal gene transfer. As a result, the enrichment of ARGs within crops at harvest under the influence of food ingestion could lead to critical concerns of public health. In this review, the prevalence and dissemination of antibiotic resistance in the soil-plant system are highlighted. Moreover, different underlying mechanisms and detection methods for ARGs transfer between the soil environment and plant compartments are summarized and discussed. On the other hand, a wide range of influencing factors for the transfer and distribution of antibiotic resistance within the soil-plant system are also presented and discussed. In response to exposure of antibiotic residues and resistomes, corresponding hazard identification assessments have been summarized, which could provide beneficial guides of the toxicological tolerance for the general population. Finally, further research priorities for detection and management ARGs spread are also suggested.

Antibiotic resistance profiles on pathogenic bacteria in the Brazilian environments

The present study aimed to elaborate a review of multidrug-resistant (MDR) bacteria in soil, food, aquatic environments, cattle, poultry, and swine farms in Brazil. Initially, the literature database for published papers from 2012 to 2023 was Scientific Electronic Library Online (SciELO), U.S. National Library of Medicine (PubMed), and Google Scholar, through the descriptors: antimicrobial resistance, resistance profile, multidrug resistance, environmental bacteria, and pathogenic bacteria. The studies demonstrated the prevalence of pathogenic and resistant bacteria in environments that favor their rapid dissemination. Bacteria of medical importance, such as Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Listeria monocytogenes, Salmonella spp., Shigella spp., Vibrio spp., were present in samples from animal farms and foods, including cheese and milk, urban aquatic environments, hospital effluents, and shrimp farms. Studies suggested that important bacteria have been disseminated through different niches with easy contact with humans, animals, and food, demonstrating the danger of the emergence of increasingly difficult conditions for treating and controlling these infections. Thus, better understanding and characterizing the resistance profiles of bacteria in these regions, mainly referring to MDR bacteria, can help develop solutions to prevent the progression of this public health problem.

Antibiotic prescription patterns and non-clinical factors influencing antibiotic use by Ecuadorian veterinarians working on cattle and poultry farms: A cross-sectional study

Understanding antibiotic prescription patterns and non-clinical factors influencing antibiotic use is essential for implementing strategies to promote appropriate antibiotic use. There is, however, limited research exploring these issues with Ecuadorian veterinarians. Therefore, a questionnaire was developed and applied cross-sectionally to veterinarians (n = 173) from two professional organizations to explore the antibiotic prescription patterns and non-clinical factors (e.g., attitudes and perceptions) influencing antibiotic use, and to identify strategies to reduce antibiotic use. The response rate was 78.4%. Responses were compared between veterinarians working mainly on cattle and poultry farms using Mann-Whitney U tests. The most important attitudes, beliefs and perceptions towards antimicrobial resistance (AMR) and antibiotic use were identified with the Relative Importance Index (RII). Veterinarians showed high awareness of AMR and its implications for public health, as well as the necessity of reducing antibiotic use. However, some veterinarians appear to underestimate the potential contribution of veterinary antibiotic use on AMR in humans. Veterinarians self-reported high prescription (> 20%) of antibiotics for cattle and poultry that are critically important for human medicine, such as 3rd and 4th generation cephalosporins, polymyxins and quinolones. Further, antibiotic therapy was not tailored to disease type. Cattle and poultry veterinarians perceived similar barriers to increasing antibiotic stewardship including: poor biosecurity measures, animal confinement, low feed quality, farmers' behaviors (such as stopping antibiotic treatment, storing antibiotics on farms, buying antibiotics in veterinary supply stores), and sales agents' roles as non-professional prescribers of antibiotics. Overall, veterinarians were broadly supportive (>90%) of most strategies to promote appropriate antibiotic use. They saw more merit in improving biosecurity of farms and implementing educational programs for farmers and veterinarians. This study provides insight into the complexity of antibiotic use on Ecuadorian farms and the need for holistic strategies in a One Health context, to achieve antibiotic stewardship.

Occurrence of antibiotic-resistant bacteria and resistance genes in the urban water cycle

This study investigates the antibiotic resistance fate in the urban water cycle, evaluating the dynamics of antibiotic-resistant bacteria (ARB) and antibiotic-resistant genes (ARGs) in three different full-scale wastewater treatment plants (WWTPs) and two drinking water treatment plants (DWTPs) located in the same geographical area (North-West of Italy). ARB (tetracycline-, ampicillin-, and sulfonamide-resistant bacteria) were quantified by plate counting and the abundances of selected ARGs (i.e., tetA, bla_TEM, and sulII) and intI1 gene were measured using quantitative real-time PCR (qPCR). Higher concentrations of ARB and ARGs were observed in the WWTPs with respect to the DWTPs identifying the WWTP as hotspot for the spread of antibiotic resistances. Although a significant reduction of ARB and ARGs was observed in WWTPs and DWTPs after the treatment, none of the detected ARB or ARGs was completely removed in drinking water. The stability of the antibiotic-resistant rates between inlet and outlet associated with the reduction of relative ARG abundances underlined that both the treatments (WWTs and DWTs) did not apply any selective pressure. The overall results highlighted the importance to investigate the antibiotic resistance dynamics in aquatic ecosystems involved in urban water cycle integrating the information obtained by culture-dependent method with the culture-independent one and the need to monitor the presence of ARB and ARGs mainly in drinking water that represents a potential route of transmission to human.

The Impact of Tetracycline Pollution on the Aquatic Environment and Removal Strategies

Antibacterial drugs are among the most commonly used medications in the world. Tetracycline is a widely used antibiotic for human and animal therapy due to its broad-spectrum activity, high effectiveness, and reasonable cost. The indications for treatment with tetracycline include pneumonia, bone and joint infections, infectious disorders of the skin, sexually transmitted and gastrointestinal infections. However, tetracycline has become a serious threat to the environment because of its overuse by humans and veterinarians and weak ability to degrade. Tetracycline is capable of accumulating along the food chain, causing toxicity to the microbial community, encouraging the development and spread of antibiotic resistance, creating threats to drinking and irrigation water, and disrupting microbial flora in the human intestine. It is essential to address the negative impact of tetracycline on the environment, as it causes ecological imbalance. Ineffective wastewater systems are among the main reasons for the increased antibiotic concentrations in aquatic sources. It is possible to degrade tetracycline by breaking it down into small molecules with less harmful or nonhazardous effects. A range of methods for physical, chemical, and biological degradation exists. The review will discuss the negative effects of tetracycline consumption on the aquatic environment and describe available removal methods.

Antimicrobial Susceptibility Profile of Pathogenic and Commensal Bacteria Recovered from Cattle and Goat Farms

The use of antibiotics in food animals results to antimicrobial resistant bacteria that complicates the ability to treat infections. The purpose of this study was to investigate the prevalence of pathogenic and commensal bacteria in soil, water, manure, and milk from cattle and goat farms. A total of 285 environmental and 81 milk samples were analyzed for Enterobacteriaceae by using biochemical and PCR techniques. Susceptibility to antibiotics was determined by the Kirby-Bauer disk diffusion technique. A total of 15 different Enterobacteriaceae species were identified from goat and cattle farms. Manure had significantly higher (p < 0.05) Enterobacteriaceae (52.0%) than soil (37.2%), trough water (5.4%), and runoff water (5.4%). There was a significant difference (p < 0.05) in Enterobacteriaceae in goat milk (53.9%) and cow milk (46.2%). Enterobacteriaceae from environment showed 100% resistance to novobiocin, erythromycin, and vancomycin E. coli O157:H7, Salmonella spp., Enterococcus spp., and Listeria monocytogenes displayed three, five, six, and ten. AMR patterns, respectively. NOV-TET-ERY-VAN was the most common phenotype observed in all isolates. Our study suggest that cattle and goat farms are reservoirs of multidrug-resistant bacteria. Food animal producers should be informed on the prudent use of antimicrobials, good agricultural practices, and biosecurity measures.

Bacterial genome sequencing tracks the housefly-associated dispersal of fluoroquinolone- and cephalosporin-resistant Escherichia coli from a pig farm

The regular use of antimicrobials in livestock production selects for antimicrobial resistance. The potential impact of this practice on human health needs to be studied in more detail, including the role of the environment for the persistence and transmission of antimicrobial-resistant bacteria. During an investigation of a pig farm and its surroundings in Brandenburg, Germany, we detected abundant cephalosporin- and fluoroquinolone-resistant Escherichia coli in pig faeces, sedimented dust, and house flies (Musca domestica). Genome sequencing of E. coli isolates revealed large phylogenetic diversity and plasmid-borne extended-spectrum beta lactamase (ESBL) genes CTX-M-1 in multiple strains. [Correction added on 28 February 2023, after first online publication: In the preceding sentence, 'and TEM-1' was previously included but has been deleted in this version.] Close genomic relationships indicated frequent transmission of antimicrobial-resistant E. coli between pigs from different herds and across buildings of the farm and suggested dust and flies as vectors for dissemination of faecal pathogens. Strikingly, we repeatedly recovered E. coli from flies collected up to 2 km away from the source, whose genome sequences were identical or closely related to those from pig faeces isolates, indicating the fly-associated transport of diverse ESBL-producing E. coli from the pig farm into urban habitation areas. The observed proximity of contaminated flies to human households poses a risk of transmission of antimicrobial-resistant enteric pathogens from livestock to man.

Understanding networks in rural Cambodian farming communities and how they influence antibiotic use: A mixed methods study

Biosecurity and preventive animal health services in Cambodian smallholder backyard farming systems are often limited, leading to an over-reliance on antibiotics. However, data on factors influencing antibiotic use in these settings are lacking. We conducted a study in two rural Cambodian farming communities to investigate how social and contextual influences affect both human and animal antibiotic use behaviours. Data were collected in three phases: a baseline household census to enumerate village residents, a social network survey to understand village-level social ties, and in-depth interviews to elicit information about the influence of social ties on their decision-making processes. Primary outcome measures included knowledge, attitudes and practices surrounding antibiotic use, and awareness of issues relating to antibiotic resistance. Participants commonly accessed antibiotics or learned animal antibiotic use practices through village-level informal sources such as pharmacies or animal health workers. While most participants reported not using antibiotics for animal growth promotion or illness prevention, misconceptions surrounding both antibiotic effectiveness and resistance were common. Social networks capturing informal, work-related and health-related social ties showed that familial connections and geographic proximity were of primary importance for information sharing. Using exponential random graph models, we demonstrated that familial ties, and closer geographic and geodesic distance, were associated with similarity in overall antibiotic knowledge and attitudes. The informal private sector plays a major role in provision of antibiotics and antibiotic-related information in backyard farming communities, but such information is maintained within close social groups. This demonstrates the importance of engaging village-level informal sources in the provision of antibiotic-related information for both human and animal health, as well as in potential interventions to encourage appropriate antibiotic behaviours in lower-resourced settings.

Genetic characteristics, antimicrobial resistance, and prevalence of Arcobacter spp. isolated from various sources in Shenzhen, China

Arcobacter spp. is a globally emerging zoonotic and foodborne pathogen. However, little is known about its prevalence and antimicrobial resistance in China. To investigate the prevalence of Arcobacter spp. isolated from various sources, 396 samples were collected from human feces, chicken cecum, and food specimens including chicken meat, beef, pork, lettuce, and seafood. Arcobacter spp. was isolated by the membrane filtration method. For 92 strains, the agar dilution method and next-generation sequencing were used to investigate their antimicrobial resistance and to obtain whole genome data, respectively. The virulence factor database (VFDB) was queried to identify virulence genes. ResFinder and the Comprehensive Antibiotic Resistance Database (CARD) were used to predict resistance genes. A phylogenetic tree was constructed using the maximum likelihood (ML) method with core single-nucleotide polymorphisms (SNPs). We found that 27.5% of the samples (n = 109) were positive for Arcobacter spp., comprising Arcobacter butzleri (53.0%), Arcobacter cryaerophilus (39.6%), and Arcobacter skirrowii (7.4%). Chicken meat had the highest prevalence (81.2%), followed by seafood (51.9%), pork (43.3%), beef (36.7%), lettuce (35.5%), chicken cecum (8%), and human fecal samples (0%, 0/159). Antimicrobial susceptibility tests revealed that 51 A. butzleri and 40 A. cryaerophilus strains were resistant to streptomycin (98.1, 70%), clindamycin (94.1, 90%), tetracycline (64.7, 52.5%), azithromycin (43.1%, 15%), nalidixic acid (33.4, 35%), and ciprofloxacin (31.3, 35%) but were susceptible to erythromycin, gentamicin, chloramphenicol, telithromycin, and clindamycin (≤10%). A. skirrowii was sensitive to all experimental antibiotics. The virulence factors tlyA, mviN, cj1349, ciaB, and pldA were carried by all Arcobacter spp. strains at 100%, and the following percentages were cadF (95.7%), iroE (23.9%), hecB (2.2%), hecA, and irgA (1.1%). Only one A. butzleri strain (F061-2G) carried a macrolide resistance gene (ereA). One A. butzleri and one A. cryaerophilus harbored resistance island gene clusters, which were isolated from pork and chicken. Phylogenetic tree analysis revealed that A. butzleri, A. cryaerophilus, and A. skirrowii were separated from each other. To our knowledge, this is the first report of the isolation of Arcobacter spp. from vegetables and seafood in China. The resistance island gene cluster found in pork and chicken meat and the presence of virulence factors could be a potential risk to human health.

Enhancement of biological denitrification by the addition of novel sRNA Pda200 under antibiotic pressure

Paracoccus denitrificans can adapt to complex environmental changes and sRNAs play crucial roles during this process. This work aim to identify antibiotic-induced sRNA that regulated denitrification and explored its potential for functional enhancement of this process. Target prediction indicated complementary base pairing between the denitrifying gene nosZ and the sRNA Pda200. Anaerobic culture of P. denitrificans ATCC 19367 in the presence of florfenicol (FF) resulted in significant decreases in nosZ and Pda200 gene expression (p < 0.01). Two additional denitrifiers isolated from contaminated sediment were co-cultured with ATCC 19367 to generate a consortium. And an inducible Pda200 expression strain was also added. The results revealed that Pda200 significantly enhanced napA, napB and norB expression in different types of denitrifiers under FF condition (p < 0.05 ∼ 0.001). This study identified the sRNA Pda200 as a novel positive regulator of denitrification, which may realize the efficient treatment of antibiotic-contaminated wastewater by microbial agents.

Knowledge, attitudes and practices of government animal health workers on antibiotic use and antibiotic resistance in Timor-Leste

Introduction

Antibiotic resistance is a global health threat, and there is growing concern on the inappropriate use of antibiotics in the livestock sector especially in low and middle income countries. The purpose of the study was to understand the knowledge, attitudes and practices on antibiotic use and antibiotic resistance of government animal health workers in Timor-Leste.

Method

A cross-sectional survey using a census approach was conducted between August 2021 and January 2022 focusing on government animal health workers involved in field work and access to antibiotics. Interviews were face-to-face in the local Tetun language. Descriptive and regression analysis informed by causal diagrams were performed.

Result

The study found poor knowledge of antibiotics among participants, with only 8.0% (13/162) able to correctly answer questions on how antibiotics worked. Knowledge of antibiotic resistance was poor as only 29.0% (47/162) of participants had heard of antibiotic resistance and were able to accurately identify that it made antibiotics less effective. Knowledge of antibiotics and knowledge of antibiotic resistance were crudely associated with being a veterinary technician and having university education. Attitude scores were positively influenced by knowledge of antibiotics and antibiotic resistance. Antibiotics were most commonly used in pigs, cattle and buffalo, with oxytetracycline being the most commonly used antibiotics in pigs and chicken. However, most participants reported a lack in supply of this antibiotic (137/162, 78.4%) and other antibiotics. Empiric use of antibiotics in sick animals was common, and some participants used antibiotics for parasitic diseases. Less than a fifth of participants reported ever using human antibiotics, and use of antibiotics for growth promotion was uncommon.

Conclusion

There is a need to develop Timor-Leste specific treatment guidelines, strengthen veterinary diagnostic support, improve antibiotic procurement, and develop training programs to address knowledge gaps and poor practices found in this study.

Effects of melittin on laying performance and intestinal barrier function of quails

To study the effects of melittin on egg-laying performance and intestinal barrier of quails, 240 quails (aged 70 d) were randomly divided into 4 groups with 6 replicates (10 quails per replicate). They were fed with basal diet (group B), basal diet + 0.08 g/kg melittin (group BA1), basal diet + 0.12 g/kg melittin (group BA2) and basal diet + 0.16 g/kg melittin (group BA3). The experiment lasted for 21 days. The eggs were collected every day. At the end of the experiment, duodenal, jejunal, and ileal tissues were collected, and the cecal contents were sampled. Intestinal antioxidant index, barrier function, and intestinal flora were analyzed. The results showed that the addition of melittin significantly increased the laying rate and average egg weight. Addition of melittin significantly increased the antioxidant function, mechanical barrier, immune barrier, and the villus height to crypt depth ratio of small intestine. Addition of melittin had no significant effect on the α and β diversity of cecal flora, but significantly increased the abundance of Bacteroidales at family level and genus level. Bioinformatics analysis of cecal content showed significant increase in COG functional category of cytoskeleton, and significant decrease in RNA processing and modification in group BA2. KEGG functional analysis showed significant decrease in steroid biosynthesis, caffeine metabolism, and cytochrome P450 pathways in group BA2. In conclusion, addition of 0.12 g/kg melittin to feed improved the laying performance and the intestinal antioxidant capacity and barrier function of quails but had no significant effect on the composition and structure of cecal microbial community. This study provides experimental data and theoretical basis for the application of melittin as a new quail feed additive.

Can Stray Cats Be Reservoirs of Antimicrobial Resistance?

The emergence and spread of antimicrobial resistance (AMR) is a global problem that requires a One Health approach. Despite several studies have reported the role of companion animals as reservoirs of AMR, limited information is available regarding the role of cats in the circulation of AMR. In this study, we evaluated the phenotypic and genotypic profile of 75 Escherichia coli isolated from rectal swabs and fecal samples of 75 stray cats (living in solitary or in a colony) sampled in Palermo (Sicily, Italy), to determine whether these animals may participate in the spread of AMR. Susceptibility to 8 antibiotics was tested using Minimum Inhibitory Concentration assays, while the presence of the common antibiotic resistance genes blaTEM, blaCTX-M, tet(A), and tet(B) was investigated by PCR. From the 75 E. coli isolates analyzed, 43% were resistant to at least one of the eight antibiotics tested, with 31% of the isolates resistant to ampicillin, 23% to cefotaxime, 21% to tetracycline, 20% to cefazolin, and 17% to amoxicillin/clavulanic acid. Most isolates harbored the blaTEM gene (29%), followed by blaCTX-M (23%), tet(A) (21%), and tet(B) (20%). Our results confirm the fecal carriage of antibiotic-resistant E. coli and clinically relevant resistance genes in stray cats. This study highlights the potential role of stray cats in the spread of AMR in urban environments, emphasising the need to better understand their role in AMR circulation when planning strategies to combat it.

MXene-Based Nucleic Acid Biosensors for Agricultural and Food Systems

MXene is a two-dimensional (2D) nanomaterial that exhibits several superior properties suitable for fabricating biosensors. Likewise, the nucleic acid (NA) in oligomerization forms possesses highly specific biorecognition ability and other features amenable to biosensing. Hence the combined use of MXene and NA is becoming increasingly common in biosensor design and development. In this review, MXene- and NA-based biosensors are discussed in terms of their sensing mechanisms and fabrication details. MXenes are introduced from their definition and synthesis process to their characterization followed by their use in NA-mediated biosensor fabrication. The emphasis is placed on the detection of various targets relevant to agricultural and food systems, including microbial pathogens, chemical toxicants, heavy metals, organic pollutants, etc. Finally, current challenges and future perspectives are presented with an eye toward the development of advanced biosensors with improved detection performance.

Antimicrobial Resistance Profile of Common Foodborne Pathogens Recovered from Livestock and Poultry in Bangladesh

Multidrug-resistant (MDR) foodborne pathogens have created a great challenge to the supply and consumption of safe & healthy animal-source foods. The study was conducted to identify the common foodborne pathogens from animal-source foods & by-products with their antimicrobial drug susceptibility and resistance gene profile. The common foodborne pathogens Escherichia coli (E. coli), Salmonella, Streptococcus, Staphylococcus, and Campylobacter species were identified in livestock and poultry food products. The prevalence of foodborne pathogens was found higher in poultry food & by-product compared with livestock (p < 0.05). The antimicrobial drug susceptibility results revealed decreased susceptibility to penicillin, ampicillin, amoxicillin, levofloxacin, ciprofloxacin, tetracycline, neomycin, streptomycin, and sulfamethoxazole-trimethoprim whilst gentamicin was found comparatively more sensitive. Regardless of sources, the overall MDR pattern of E. coli, Salmonella, Staphylococcus, and Streptococcus were found to be 88.33%, 75%, 95%, and 100%, respectively. The genotypic resistance showed a prevalence of blaTEM, blaSHV, blaCMY, tetA, tetB, sul1, aadA1, aac(3)-IV, and ereA resistance genes. The phenotype and genotype resistance patterns of isolated pathogens from livestock and poultry had harmony and good concordance, and sul1 & tetA resistance genes had a higher prevalence. Good agricultural practices along with proper biosecurity may reduce the rampant use of antimicrobial drugs. In addition, proper handling, processing, storage, and transportation of foods may decline the spread of MDR foodborne pathogens in the food chain.

Human Colonization with Antibiotic-Resistant Bacteria from Nonoccupational Exposure to Domesticated Animals in Low- and Middle-Income Countries: A Critical Review

Data on community-acquired antibiotic-resistant bacterial infections are particularly sparse in low- and middle-income countries (LMICs). Limited surveillance and oversight of antibiotic use in food-producing animals, inadequate access to safe drinking water, and insufficient sanitation and hygiene infrastructure in LMICs could exacerbate the risk of zoonotic antibiotic resistance transmission. This critical review compiles evidence of zoonotic exchange of antibiotic-resistant bacteria (ARB) or antibiotic resistance genes (ARGs) within households and backyard farms in LMICs, as well as assesses transmission mechanisms, risk factors, and environmental transmission pathways. Overall, substantial evidence exists for exchange of antibiotic resistance between domesticated animals and in-contact humans. Whole bacteria transmission and horizontal gene transfer between humans and animals were demonstrated within and between households and backyard farms. Further, we identified water, soil, and animal food products as environmental transmission pathways for exchange of ARB and ARGs between animals and humans, although directionality of transmission is poorly understood. Herein we propose study designs, methods, and topical considerations for priority incorporation into future One Health research to inform effective interventions and policies to disrupt zoonotic antibiotic resistance exchange in low-income communities.