Emergence and spread of antibiotic-resistant foodborne pathogens from farm to table

Antibiotic resistance and preventive strategies in foodborne pathogenic bacteria: a comprehensive review

Antibiotic resistance in foodborne bacteria poses a substantial global health challenge. Reports indicate that antibiotic overuse in middle-class and low-income countries is a significant factor in the ever-increasing resistance. Resistance mechanisms have developed through enzymatic hydrolysis, reduced membrane permeability, efflux pumps, and target site mutations. Preventive measures like proper hygiene and safe food preparation, vaccination, antibiotic stewardship and surveillance, implementing infection prevention and control (IPC) measures, good agricultural practices, and investigating novel approaches like CRISPR, NGS, nanotechnology, and bacteriophages may be employed to address this challenge. Naturally occurring preservatives (e.g., nisin) are alternatives to antibiotics for food preservation. Prebiotics, probiotics, nanobiotics, phage treatment, and antimicrobial peptides are also substitutes for antibiotics. Furthermore, plant-derived compounds, such as essential oils and plant extracts, are promising substitutes for antibiotics in animal production. This review focuses on the mechanisms of underlying antibiotic resistance in foodborne pathogens, necessary preventive measures, and the challenges associated.

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Phage applications for biocontrol of enterohemorrhagic E. coli O157:H7 and other Shiga toxin-producing Escherichia coli

Foodborne outbreaks are becoming increasingly common and linked to zoonotic diseases caused by microbial spillover from wild or farm animals. Furthermore, agricultural animals could be considered reservoirs of multidrug-resistant (MDR) microorganisms. Escherichia coli O157:H7, a widespread foodborne pathogen, poses a substantial hazard due to its ubiquitous environmental distribution, MDR phenotypes, and life-threatening pathogenicity. This bacterium produces a potent toxin (Shiga toxin, Stx) encoded by prophages (Stx-phage). In addition to antibiotic resistance, E. coli O157:H7 has been shown to express more Stx upon treatment with antibiotics such as trimethoprim-sulfamethoxazole and metronidazole than controls. The combination of MDR and increased pathogenicity upon antibiotic treatment requires the development of alternatives for treating and preventing E. coli O157:H7 and related bacteria. Bacterial viruses (phages) are gaining popularity in clinical and veterinary settings due to their high antibacterial activities and lack of side effects in animals. Phage application in food production can help reduce the spread of E. coli O157:H7 and other Stx-producing E. coli (STEC), thus decreasing the burden of infection and economic loss due to these foodborne zoonoses. The present review will provide an update on phage utilization in the food industry to reduce the STEC load, with particular focus on O157:H7.

Patterns of antibiotic resistance in urinary tract infections before and during the COVID-19 pandemic in Uganda and Tanzania

Background

Increased antimicrobial use during the COVID-19 pandemic has driven antimicrobial resistance (AMR) globally, particularly in resource-limited settings. This study assessed AMR patterns in urinary tract infections (UTIs) in Uganda and Tanzania before and during the pandemic.

Methods

A cross-sectional study was conducted among UTI patients at healthcare facilities in Mbarara (Uganda) and Mwanza (Tanzania) between March 2019-September 2020 and January-December 2021. Mid-stream urine samples were collected and analysed following standard procedures. AMR patterns were compared across the two periods.

Results

A total of 5563 patients were enrolled from Mwanza (55.0%, n = 3061) and Mbarara (45.0%, n = 2502). The overall prevalence of microbiologically confirmed UTIs in Mwanza was 32.5% (999/3060; 95% CI: 30.9%-34.3%), raised from 30.1% (655/2180; 95% CI: 28.1%-32.0%) before to 39.1% (344/880; 95% CI: 35.8%-42.4%) during the pandemic. Whereby, the overall prevalence of microbiologically confirmed UTIs in Mbarara was 24.8% (620/2502; 95% CI: 23.1%-26.5%), decreasing from 27.5% (502/1824; 95% CI: 25.5%-29.6%) before to 17.4% (118/678; 95% CI: 14.6%-20.5%) during the pandemic. The proportion of multidrug-resistant Gram-negative bacteria (MDR-GNB) rose significantly (74% versus 83.4%, P = 0.01) while MDR Gram-positive bacteria (MDR-GPB) increased slightly (55.5% versus 56.7%, P = 0.45) in Mwanza. Conversely, MDR-GPB increased substantially (31.4% versus 51.6%, P = 0.09) while MDR-GNB decreased (67.3% versus 61.9%, P = 0.22) in Mbarara.

Conclusions

This study provides critical insights into AMR trends in UTI pathogens in Tanzania and Uganda, emphasizing the need for stringent antimicrobial stewardship, requiring ongoing surveillance and targeted interventions.

Feeding systems influence the rumen resistome in yaks by changing the microbiome

The rumen microbiome serves as a reservoir of antibiotic-resistance genes (ARGs) with significant implications for public health. This study aimed to investigate the effects of different feeding systems on the rumen resistome in yaks. Yaks that grazed naturally on pasture were used as controls, while the experimental yaks were housed in a high-density pen environment and fed a specially designed diet to optimally meet their nutritional requirements, with increased interactions with farm workers. Metagenomic analysis was performed to assess changes in the rumen microbiome and resistome. Dietary factors influencing changes in the rumen microbiome and resistome were identified. A greater variety of microbiomes associated with carbohydrate digestion was found in yaks under a house-feeding system, such as Stomatobaculum longum and Succiniclasticum ruminis. Although grazing yaks exhibited various dominant antibiotic resistance genes (ARGs) at the class level, house-fed yaks were mainly enriched with tetracycline-resistant genes. A random forest model identified specific ARG signatures for each group, such as Sent_cmlA and Sliv_cmlR (Phenicol) and vanHD (Glycopeptide) prevalent in grazing yaks, while tet44, tetW, tetW/N/W, and tet40 were abundant in house-fed yaks. ARG interactions varied by feeding system, with signature ARGs in each group showing distinct correlations. Nevertheless, strong correlations among ARGs existed regardless of the treatments, such as the positive correlation between tetW and tetW/N/W in both groups. The rumen microbiome was strongly associated with the resistome, especially regarding abundant microbiomes and ARGs. Proteobacteria carrying ARGs were observed in grazing yaks, while Firmicutes served as hosts for ARGs in yaks under a housed feeding system. The specific bacteria contributing to the distinct ARGs in each group were identified. For instance, members of Firmicutes (Clostridium tepidiprofundi) carried their ARG signatures, such as tet44. These findings emphasized that diet, along with environmental factors and farmworker interactions, contributed to changes in the rumen resistome of yaks. This study is the first to discuss how multiple factors within a feeding regime influence the gut resistome, highlighting the drawbacks of intensive feedings with respect to the gut resistome.

Antibiotic Resistance Dissemination and Mapping in the Environment Through Surveillance of Wastewater

Antibiotic resistance is one of the major health threat for humans, animals, and the environment, according to the World Health Organization (WHO) and the Global Antibiotic-Resistance Surveillance System (GLASS). In the last several years, wastewater/sewage has been identified as potential hotspots for the dissemination of antibiotic resistance and transfer of resistance genes. However, systematic approaches for mapping the antibiotic resistance situation in sewage are limited and underdeveloped. The present review has highlighted all possible perspectives by which the dynamics of ARBs/ARGs in the environment may be tracked, quantified and assessed spatio-temporally through surveillance of wastewater. Moreover, application of advanced methods like wastewater metagenomics for determining the community distribution of resistance at large has appeared to be promising. In addition, monitoring wastewater for antibiotic pollution at various levels, may serve as an early warning system and enable policymakers to take timely measures and build infrastructure to mitigate health crises. Thus, by understanding the alarming presence of antibiotic resistance in wastewater, effective action plans may be developed to address this global health challenge and its associated environmental risks.

An autocatalytic hybridization circuit-based FRET aptasensor for detection of low-abundant sulfameter in human serum

Exposure to antibiotics is considered a potential risk factor for human health. Yet, the extensive and cost-effective detection of low-abundant antibiotics in complex matrices remains a significant challenge. Herein, an aptamer and an autocatalytic hybridization circuit (AHC) were used to fabricate a fluorescence resonance energy transfer (FRET) platform to detect sulfameter (SME) in human serum. The AHC system comprised two mutually motivated hybridization chain reactions (HCR) modules, ultimately producing long-branched DNA copolymeric nanowires. This mutually reciprocal activation of two HCR modules enables continuous signal amplification, providing the AHC system with wide linear range and high sensitivity for the SME detection. Compared to the HCR-based aptasensor, the AHC-based aptasensor exhibited a wider linear range and improved sensitivity (3.3 times greater). Under optimal conditions, the fluorescent AHC-based aptasensor demonstrated a linear range (R2 was 0.996) from 0.5 to 2000 nM, with a low detection limit of 0.301 nM (S/N = 3). The fluorescent aptasensor was also validated by SME-spiked human serum samples, showing average recoveries ranging from 96.40 % to 109.30 %, with a relative standard deviation below 10.45 %. Furthermore, when tested on six human serum samples, the aptasensor results were consistent with those obtained from the commercial ELISA method. These findings demonstrate that the proposed aptasensor provides a promising approach for the practical monitoring of low-abundant SME in human serum.

Antibiogram profile of Enterococcus faecalis and Enterococcus faecium in chicken meat from supermarkets in Sleman District, Indonesia

Background and Aim

Enterococci are commensal bacteria in the digestive tract of poultry and serve as indicators of fecal contamination. Their significance in veterinary and human medicine arises from their ability to acquire antibiotic-resistance genes, posing a potential public health risk. Poultry meat, a major protein source in Indonesia, can act as a reservoir for Enterococcus species, transferring antibiotic-resistant strains to humans through food handling. Despite rigorous hygiene standards in supermarket supply chains, limited studies have assessed contamination levels. This study aimed to identify Enterococcus species from supermarket chicken meat in Sleman District, Yogyakarta, Indonesia, and evaluate their antibiotic resistance profiles.

Materials and Methods

Chicken breast samples were randomly collected from three Supermarkets (A, B, and C). Bacterial isolation was performed using buffered peptone water and enterococcosel agar. Presumptive colonies were confirmed by polymerase chain reaction for genus and species identification. Antibiotic susceptibility was assessed using the Kirby-Bauer disk diffusion method against ampicillin (AMP), tetracycline (TET), erythromycin (ERY), and vancomycin (VAN).

Results

A total of 269 Enterococcus isolates were confirmed, including 163 Enterococcus faecium (EFM), 92 Enterococcus faecalis (EFS), and 14 other Enterococcus species. Resistance to AMP, TET, and ERY in EFM was 12.12%, 57.57%, and 66.67%, respectively, while resistance in EFS was 4.54%, 31.82%, and 63.63%. No isolates showed resistance to VAN. Multidrug resistance (MDR) was observed in 60.60% of EFM and 36.36% of EFS isolates.

Conclusion

Despite high susceptibility to AMP and VAN, resistance to TET and ERY was prevalent. The presence of MDR isolates underscores the need for continuous surveillance of antibiotic resistance in Enterococcus species within the food chain. This study highlights the necessity of further research with expanded sampling and antibiotic panels to assess the dissemination of antibiotic resistance genes and potential public health risks.

The Gut Bacteria of Gampsocleis gratiosa (Orthoptera: Tettigoniidae) by Culturomics

Gampsocleis gratiosa Brunner von Wattenwyl, 1862, is a type of omnivorous chirping insect with a long history of artificial breeding. It has high economic value and is also an excellent orthopteran model organism. In this study, 12 types of culture media combined with 16S rRNA sequencing were employed to isolate 838 bacterial strains from the gut of G. gratiosa. After sequence comparison, a total of 98 species of bacteria were identified, belonging to 3 phyla, 5 classes, 11 orders, 20 families, and 45 genera. Firmicutes and Proteobacteria accounted for the majority (92.86%). At the order level, Enterobacteriaceae, Bacillales, and Lactobacillales predominated (79.59%). At the genus level, Klebsiella (11.22%) and Enterococcus (7.14%) predominated. This study also enumerated the strain morphological, physiological and biochemical properties of 98 species of bacteria, including colony morphology, Gram staining, bacterial motility test, temperature gradient growth, pH gradient growth, citrate utilization test, temperature oxidase test, contact enzyme test, methyl red test, V-P test, indole test, gelatin liquefaction test, nitrate reduction test, hydrogen sulfide test, starch hydrolysis test, cellulose decomposition test, esterase (corn oil) test and antibiotic susceptibility testing. Additionally, 16 antibiotics were utilized to test the bacterial susceptibility of the strains. This study explored the types and community structure of some culturable microorganisms in the intestinal tract of G. gratiosa and recorded their physiological characteristics. These data reflect the physiological functions of the intestinal microorganisms of G. gratiosa and provide support for subsequent research on the interaction mechanism between microorganisms and their hosts.

Effects of dietary dihydroartemisinin on growth performance, meat quality, and antioxidant capacity in broiler chickens

This study aimed to investigate the effects of dietary dihydroartemisinin on the growth performance, meat quality, and antioxidant capacity of broiler chickens. Four-hundred one-day-old Arbor Acres male broilers were randomly assigned to five treatment groups with eight replicates and ten birds each. All broilers were fed a basal diet containing 0, 5, 10, 20 or 40 mg/kg dihydroartemisinin. The results showed that dihydroartemisinin at 10 mg/kg quadratically increased ADG, and dihydroartemisinin at 10 and 20 mg/kg quadratically increased ADFI during the days 1-21 period. Compared to the control group, dihydroartemisinin at 10 and 20 mg/kg quadratically decreased the drip loss at 24 h. Dihydroartemisinin linearly and quadratically decreased the L* value of breast muscles. Dihydroartemisinin at 20-40 mg/kg linearly and quadratically decreased the MDA concentrations at D5 and D 7 of postmortem storage. Dihydroartemisinin linearly and quadratically increased the ABTS scavenging activity at D 7 of postmortem storage. Dietary 20 mg/kg dihydroartemisinin at 21 days and 40 mg/kg dihydroartemisinin at 42 days linearly and quadratically increased serum glutathione concentrations. Dihydroartemisinin at 5-40 mg/kg linearly increased serum total superoxide dismutase activity at 42 days. Dihydroartemisinin at 10-20 mg/kg quadratically decreased serum malondialdehyde contents at 42 days. At 21 days, 20 mg/kg dihydroartemisinin quadratically increased hepatic glutathione concentrations and catalase activities. Compared to the control group, 40 mg/kg dihydroartemisinin linearly and quadratically decreased hepatic malondialdehyde contents. At 42 days, 20 mg/kg dihydroartemisinin quadratically increased catalase activities and reduced the malondialdehyde contents in liver. Dihydroartemisinin quadratically increased the hepatic mRNA expression of Nrf2. Compared to the control group, dihydroartemisinin at 10 and 20 mg/kg quadratically induced the hepatic mRNA expression of HO-1. Dihydroartemisinin at 10-40 mg/kg linearly and quadratically increased the mRNA expression of CAT in liver. These results showed that dihydroartemisinin improved growth performance, meat quality, and antioxidant capacity of broiler chickens, especially at 10 and 20 mg/kg.

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.

Knowledge, Attitudes, and Practices Toward Antibiotic Use in Food-Producing Animals Among University Students in Seven Cities in Southern and Central China: A Cross-Sectional Study

Background: The misuse of antibiotics in both humans and food-producing animals poses significant risks to human health and contributes to the rise of antibiotic resistance. Raising public awareness is crucial to managing antibiotic resistance, particularly among university students, as they represent a future force in tackling this global issue. Methods: A cross-sectional study was conducted from July 2022 to May 2024 in seven cities in Southern and Central China to assess university students' knowledge, attitude, and practice regarding antibiotic use in humans and food-producing animals. Binary logistic regression was used to identify associated factors. Results: A total of 6357 students from 72 universities participated. Less than half of the students answered the knowledge items appropriately. Only 21.47% to 29.98% had a proper understanding of basic antibiotic concepts and their use in humans and food-producing animals. Respectively, 21.49% and 28.50% students paid attention to antibiotic content in food from food-producing animals and refused to buy food containing antibiotics. Factors associated with higher knowledge, attitude, and practice total scores included being male, being of older age, having a postgraduate education, majoring in the medical science discipline, studying at a double-first-class university, having a higher family monthly income, having parents in the medical area, and using antibiotics in the past year (p < 0.001). Conclusions: Given students' insufficient knowledge-particularly in identifying antibiotics and understanding their functions-and inappropriate practices related to purchasing food from food-producing animals, targeted education programs are suggested. These programs should address the fundamental concepts of antibiotic use in both humans and food-producing animals while providing practical guidance on individual behaviors to help mitigate antibiotic resistance.

Antioxidant and Antibacterial Properties of Ethanolic Pot-Pollen Extracts of Melipona beecheii and Determination of the Major Components by GC-MS

Melipona beecheii pot-pollen is a natural product that has barely been studied, unlike other hive products such as honey and propolis. Its application has been reported since ancient times in traditional Mayan medicine, and it is also a functional food with high nutritional value. In the present study, samples of ethanolic pot-pollen extracts from five locations in the Yucatán Peninsula were analyzed to determine their antibacterial and antioxidant properties. All the extracts showed activity against five medically important bacteria; Pseudomonas aeruginosa and Listeria monocytogenes were the most susceptible bacteria in all samples. The evaluated antioxidant activity was higher than that reported by other studies. Palmitic, linoleic, and linolenic fatty acids and their respective ethyl ethers were detected by Gas Chromatography-Mass Spectrometry (GC-MS) in all samples in different concentrations. Based on these results, pot-pollen extract from Mama, Yucatán exhibited the best biological activities (Minimum Inhibitory Concentrations (MICs) between 6 and 40 mg/mL, EC50 DPPH 28 μg/mL, EC50 RP 30 μg/mL), which could be related to a higher content of unsaturated fatty acids and their ethyl esters. The present study demonstrates that M. beecheii pot-pollen has therapeutic potential in addition to its benefits as a nutritional supplement.

Emergence and genomic epidemiology of tigecycline resistant bacteria of fly origin across urban and rural China

Plasmid-mediated tigecycline resistance genes, notably the tet(X) and tmexCD-toprJ genes, have garnered considerable attention due to their transferability. This study aims to investigate the prevalence and resistance mechanisms associated with tet(X) and tmexCD-toprJ in flies, which are important reservoirs of antimicrobial resistance genes. A total of 52 tigecycline resistant bacterial isolates were collected, among which 40 (76.9 %) and 12 (23.1 %) were positive for tet(X) and tmexCD-toprJ, respectively. Tigecycline resistant bacteria were isolated from diverse geographical locations in China, with tet(X4)-positive Escherichia coli and tmexCD1-toprJ1-positive Klebsiella pneumoniae dominant among the isolates. The prevalence of tet(X) in rural area was significantly higher than that in urban area (2.7 % vs. 0.3 %; P < 0.001), while the prevalence of tmexCD1-toprJ1 shows no significant difference between urban and rural areas (0.2 % vs. 0.6 %; P > 0.05). Most tet(X)-positive strains (n = 40, 100.0 %), and 11(91.7 %) of the tmexCD1-toprJ1-positive strains exhibited multi-drug resistance. The IncFIB(Mar)/IncHI1B hybrid plasmid carrying tmexCD1-toprJ1 was identified by whole-genome sequencing analysis, which dominated the transmission of tmexCD1-toprJ1 in K. pneumoniae. Genetic context analysis showed that tmexCD1-toprJ1 was related locally to IS26, and IS26 may exacerbate the spread of tmexCD1-toprJ1 in different bacteria. In addition, the genetic structure of tmexCD1-toprJ1 also contains several antimicrobial resistance genes, including aph(3')-Ic, sul1, blaDHA-1, blaCTX-M-5, etc., conferring resistance to aminoglycosides, sulfonamides, and carbapenems. This study provides insights into the epidemiology and transmission dynamics of tigecycline resistance genes, informing targeted intervention strategies to mitigate antimicrobial resistance dissemination.

Synergistic antimicrobial action of chlorogenic acid and ultraviolet-A (365 nm) irradiation; mechanisms and effects on DNA integrity

Chlorogenic acid (CGA) is abundant in various plants and notably in coffee beans. This study investigated the bactericidal activity of CGA combined with ultraviolet-A light (UVA, 365 nm) (CGA + UVA) against Escherichia coli DH5α, with the aim of developing novel strategies for food preservation and healthcare. CGA + UVA treatment was superiorin reducing bacterial survival than either treatment alone. At 20 J/cm2 and pH 7, CGA (0.3%) + UVA treatment resulted in only about a 3-log reduction in bacterial survival, whereas at 15 J/cm2 and pH 3, no surviving bacteria could be detected, demostrating that the treatment was more effective at acidic pH. CGA + UVA treatment was also bactericidal in green plum juice, confirming that its low pH-dependent property could be effective in acidic food products. To elucidate the bactericidal mechanism of CGA + UVA treatment, its effects on reactive oxygen species (ROS) generation, membrane integrity, and enzyme activity were measured. ROS generated via the type-1 reaction, such as hydrogen peroxide (H2O2) and hydroxyl radicals (·OH), were mainly detected. CGA + UVA disrupted the bacterial cell membrane, causing the leakage of cellular components, particularly proteins. CGA + UVA treatment also led to deoxyribonucleic acid (DNA) degradation and reduced succinate-coenzyme Q reductase activity by approximately 72 %. Furthermore, CGA + UVA treatment decreased β-lactamase activity and plasmid transforming efficacy with maximal reductions of 68 % and 98 %, respectively, highlighting its potential for increasing antibiotic susceptibility and preventing the spread of antimicrobial resistance. The results demonstrate that CGA + UVA treatment could be used to effectively combat antibiotic-resistant bacteria and prevent the spoilage of preserved foods or food poisoning.

Dietary Pleurotus citrinopileatus Polysaccharide Improves Growth Performance and Meat Quality Associated with Alterations of Gut Microbiota in Arbor Acre Broilers

Adding edible fungal polysaccharides to animal diets improves growth performance, meat quality, intestinal health, and immunity without adverse effects. This study aimed to evaluate the impact of Pleurotus citrinopileatus polysaccharide (PCP, including PCP250, PCP500, PCP750, and PCP1000 mg/kg) on the growth performance, meat quality, and microbial composition of Arbor Acre (AA) broilers (total 180) by metabolomics and high-throughput sequencing. The results showed that adding PCP enhanced chicken meat tenderness, redness (a*), and water retention and raised essential amino acids and flavor amino acids (such as umami and sweet amino acids) content. The metabolomics revealed that IMP, creatine, betaine, sarcosine, and taurine were related to improving meat quality in broilers by PCP addition. In addition, amino acid, purine, and lipid metabolism were the main metabolic pathways. Moreover, PCP could regulate muscle metabolism by increasing the relative abundance of Lachnospiraceae and Lactobacillus and the content of short-chain fatty acids (SCFAs). Therefore, PCP may become a promising new dietary supplement in the future, which may improve the yield and quality of broiler chickens.

Nanocomposites: silver nanoparticles and bacteriocins obtained from lactic acid bacteria against multidrug-resistant Escherichia coli and Staphylococcus aureus

Drug-resistant bacteria such as Escherichia coli and Staphylococcus aureus represent a global health problem that requires priority attention. Due to the current situation, there is an urgent need to develop new, more effective and safe antimicrobial agents. Biotechnological approaches can provide a possible alternative control through the production of new generation antimicrobial agents, such as silver nanoparticles (AgNPs) and bacteriocins. AgNPs stand out for their antimicrobial potential by employing several mechanisms of action that can act simultaneously on the target cell such as the production of reactive oxygen species and cell wall rupture. On the other hand, bacteriocins are natural peptides synthesized ribosomally that have antimicrobial activity and are produced, among others, by lactic acid bacteria (LAB), whose main mechanism of action is to produce pores at the level of the cell membrane of bacterial cells. However, these agents have disadvantages. Nanoparticles also have limitations such as the tendency to form aggregates, which decreases their antibacterial activity and possible cytotoxic effects, and bacteriocins have a narrow spectrum of action, require high doses to be effective, and can be degraded by proteases. Given these limitations, nanoconjugates of these two agents have been developed that can act synergistically in the control of pathogenic bacteria resistant to antibiotics. This review focuses on knowing relevant aspects of the antibiotic resistance of E. coli and S. aureus, the characteristics of these new generation antibacterial agents, and their effect alone or forming nanoconjugates that are more effective against the multiresistant mentioned bacteria.

An Overview of the Recent Advances in Antimicrobial Resistance

Antimicrobial resistance (AMR), frequently considered a major global public health threat, requires a comprehensive understanding of its emergence, mechanisms, advances, and implications. AMR's epidemiological landscape is characterized by its widespread prevalence and constantly evolving patterns, with multidrug-resistant organisms (MDROs) creating new challenges every day. The most common mechanisms underlying AMR (i.e., genetic mutations, horizontal gene transfer, and selective pressure) contribute to the emergence and dissemination of new resistant strains. Therefore, mitigation strategies (e.g., antibiotic stewardship programs-ASPs-and infection prevention and control strategies-IPCs) emphasize the importance of responsible antimicrobial use and surveillance. A One Health approach (i.e., the interconnectedness of human, animal, and environmental health) highlights the necessity for interdisciplinary collaboration and holistic strategies in combating AMR. Advancements in novel therapeutics (e.g., alternative antimicrobial agents and vaccines) offer promising avenues in addressing AMR challenges. Policy interventions at the international and national levels also promote ASPs aiming to regulate antimicrobial use. Despite all of the observed progress, AMR remains a pressing concern, demanding sustained efforts to address emerging threats and promote antimicrobial sustainability. Future research must prioritize innovative approaches and address the complex socioecological dynamics underlying AMR. This manuscript is a comprehensive resource for researchers, policymakers, and healthcare professionals seeking to navigate the complex AMR landscape and develop effective strategies for its mitigation.

Unveiling the traits of antibiotic resistance and virulence in Escherichia coli obtained from poultry waste

Antibiotic resistance and virulence factors in avian pathogenic Escherichia coli (APEC) have become significant concerns, contributing to adverse environmental effects. The extensive use of antibiotics in poultry farming has resulted in the emergence of antibiotic-resistant APEC strains. This study prioritizes the molecular screening of APEC to uncover their antibiotic resistance and virulence attributes, with specific attention to their environmental impact. To address the imperative of understanding APEC pathogenesis, our study analyzed 50 poultry waste samples including 10 poultry litter, 15 fecal matter, 15 wastewater, and 10 anatomical waste samples. For the presence of virulence genes, 35 Escherichia coli isolates were subjected to molecular characterization. Amongst these, 27 were APEC strains demonstrating the presence of at least four virulence genes each. Notably, virulence genes such as fimH, ompA, ybjX, waaL, cvaC, hlyF, iss, ompT, and iroN were observed among all the E. coli isolates. Furthermore, eleven of the APEC strains exhibited resistance to tetracycline, ampicillin, sulphonamides, and fluoroquinolones.These findings highlight the role of APEC as a potential source of environmental pollution serving as a reservoir for virulence and resistance genes. Understanding the dynamics of antibiotic resistance and virulence in APEC is essential due to its potential threat to broiler chickens and the broader population through the food chain, intensifying concerns related to environmental pollution. Recognizing the ecological impact of APEC is essential for developing effective strategies to mitigate environmental pollution and safeguard the health of ecosystems and human populations.

Alternatives to antibiotic growth promoters for poultry: a bibliometric analysis of the research journals

The need to develop novel alternatives to antibiotics gained prominence following the ban on sub-therapeutic antibiotic applications for livestock growth enhancement. This prohibition led to a surge in research papers exploring potential alternatives to antibiotics to promote growth and health in poultry. As a result, it has become imperative to synthesize information regarding research accomplishments and publication patterns in antibiotic alternatives, to assess research gaps and aid regulatory, funding, and research entities in making informed decisions. Consequently, our study aims to systematically analyze and comprehend the research and publication trends related to growth-promoting antibiotic alternatives in poultry. We identified all publications during the search period from 2009 to 2022, utilizing various bibliometric analysis datasets from Scopus, Web of Science/InCites, and Dimensions. The Rayyan web application was employed for manual deduplicating, labeling, and screening the relevant publications. From an initial pool of 2038 publications, we screened and categorized 816 based on factors such as alternative antibiotic categories, publication years, countries, species, journals, and institutes. Our findings reveal that the most prevalent publications are centered around probiotic (30.51%) and phytogenic (24.02%). Notably, the United States leads publication output, followed by China and Egypt. Among poultry species, broilers emerge as the most extensively studied category, followed by layer chickens. Universities emerge as the foremost contributors to antibiotic alternative research, while government institutes and industry occupy the second and third positions, respectively. Upon scrutinizing the journals responsible for the highest publication count and most cited papers, it became evident that the journal "Poultry Science" leads with the highest percentage (13.51%) and the most highly cited publications, accounting for five out of eleven highly cited articles. This comprehensive review outlines research trends concerning diverse antibiotic alternatives, taking into account poultry species and geographical distribution. The future trajectory in this domain is projected to encompass a blend of various antibiotic alternatives that could be administered as a single product and/or the innovative use of novel antibiotic alternatives.

Biosafety assessment of laying hens fed different treatments of black soldier flies (Hermetia illucens) under doxycycline stress

The black soldier fly (BSF, Hermetia illucens) is a resource insect that can utilize livestock and poultry feces. However, BSFs may also increase the risk of transmission of antibiotic resistance genes (AGRs) that are widespread in livestock and poultry farm environments. Therefore, we aimed to evaluate the biosecurity risks of different BSF treatments in the laying chicken food chain using the "chicken manure-BSF-laying hens" model. Our results indicated that different BSF treatments significantly affected antibiotic residue, ARGs, MGEs, bacterial antibiotic resistance, and bacterial microbial community composition in the food chain of laying hens fed BSFs. These risks can be effectively reduced through starvation treatment and high-temperature grinding treatment. Comprehensive risk assessment analysis revealed that starvation combined with high-temperature milling (Group H) had the greatest effect.

Effect of Early Ciprofloxacin Administration on Growth Performance, Meat Quality, Food Safety, and Metabolomic Profiles in Xueshan Chickens

To investigate the effects of early administration of ciprofloxacin (CIP) on Xueshan chickens, in this study Xueshan chickens were measured for growth performance, tested for drug residues, evaluated for meat quality, and muscle metabolism changes were explored using a non-target metabolomics approach. Experimental findings revealed that early CIP use did not significantly impact the overall growth rate of Xueshan chickens (p > 0.05). However, notable alterations in meat quality were observed: the CIP-treated group exhibited a significant decrease in muscle pH (pH1 and pH24) and a marked increase in drip loss and moisture content (p > 0.05). No CIP residues were detected in muscle tissue. Untargeted metabolomics analyses unveiled significant alterations in the metabolic profile of market-age chickens following CIP treatment. Both functional enrichment and metabolic network analyses indicated significant effects on the ko01120 (microbial metabolism in diverse environments) and ko00350 (tyrosine metabolism) pathways, implying that CIP treatment may influence chicken meat quality by modulating microbial communities and amino acid metabolism. This study provides a crucial foundation for understanding the impact of antibiotics on meat quality and metabolism in poultry production, offering scientific insights for optimizing antibiotic-use strategies and safeguarding poultry product quality.

From Herd Health to Public Health: Digital Tools for Combating Antibiotic Resistance in Dairy Farms

The emergence of antimicrobial resistance (AMR) is a significant threat to global food security, human health, and the future of livestock production. Higher rates of antimicrobial use in dairy farming and the sheer lack of new antimicrobials available for use focused attention on the question of how the dairy production sector contributed to the development of AMR and paved the path toward taking action to curtail it on the targeted type of farms. This paper aims to provide an introduction to a phenomenon that has gained considerable attention in the recent past due to its ever-increasing impact, the use of antimicrobial drugs, the emergence of antimicrobial resistance (AMR) on dairy farms, and seeks to discuss the possibilities of approaches such as digital health monitoring and precision livestock farming. Using sensors, data, knowledge, automation, etc., digital health monitoring, as well as Precision Livestock Farming (PLF), is expected to enhance health control and minimize disease and antimicrobial usage. The work presents a literature review on the current status and trends of AMR in dairy farms, an understanding of the concept of digital health monitoring and PLF, and the presentation and usefulness of digital health monitoring and PLF in preventing AMR. The study also analyses the strengths and weaknesses of adopting and incorporating digital technologies and artificial intelligence for dairy farming and presents areas for further study and level of use.

In Vivo and in Vitro Mitigation of Salmonella Typhimurium Isolates by Fortunella Japonica Fruit Extract

The vast dissemination of resistance to different antibiotics among bacterial pathogens, especially foodborne pathogens, has drawn major research attention. Thus, many attempts have been made to reveal novel alternatives to the current antibiotics. Due to their variable pharmacologically active phytochemicals, plants represent a good solution for this issue. This study investigated the antibacterial potential of Kumquat or Fortunella japonica methanol extract (FJME) against Salmonella typhimurium clinical isolates. Gas chromatography coupled with mass spectrometry (GC/MS) characterized 39 compounds in FJME. Palmitic acid (15.386%) and cis-vaccenic acid (15.012%) are the major active constituents detected by GC/MS. Remarkably, FJME had minimum inhibitory concentrations from 128 to 512 µg/mL in vitro. In addition, a systemic infection model revealed the in vivo antibacterial action of FJME. The antibacterial therapeutic activity of FJME was noticed by improving the histological features of the liver and spleen. Moreover, there was a perceptible lessening (p < 0.05) of the levels of the oxidative stress markers (nitric oxide and malondialdehyde) using ELISA. In addition, the gene expression of the proinflammatory cytokine (interleukin 6) was downregulated. On the other hand, there was an upregulation of the anti-inflammatory cytokine (interleukin 10). Accordingly, future clinical investigations should be done to reveal the potential antibacterial action of FJME on other food pathogens.

Effect of a probiotic mixture with lactic acid activity on productive and allometric indicators in broiler chickens

Background and Aim

The feeding and sanitary conditions significantly influence the productivity of farm animals. This study aimed to assess the impact of a lactic acid-producing microbial additive on broiler chicken productivity.

Materials and Methods

A 42-day experimental period utilized 120 1-day-old Cobb 500 chicks with an average weight of 46 g. In groups of 30 each, the chicks were randomly assigned to four experimental designs. The following treatments were assessed: T1 without intervention (control), T2 with bacitracin at a concentration of 0.5 g/L, T3 with a 5% probiotic mixture (PM), and T4 with a 7.5% PM. The birds were fed the commercial balanced feed without anticoccidials daily, while vaccines were administered according to the recommended biosecurity plan by the commercial house. Drinking water was treated with PM containing lactobacilli, yeasts, and short-chain organic acids.

Result

In T4, a 7.5% PM resulted in a final weight of 2361.2 g (p < 0.05), a total weight gain of 1412.8 g (p < 0.05), and improved feed efficiency with a feed conversion of 2.00 (p < 0.05), during which feed intake was lower than in the other groups.

Conclusion

Microbial additives with lactic acid activity are a cost-effective and feasible solution for broiler chicken productivity.

Antibiotic-Resistant Bacteria Isolated from Street Foods: A Systematic Review

Street food may be a vehicle of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) to humans. Foods contaminated with ARB entail serious problems or challenges in the fields of medical care, animal husbandry, food industry, and public health worldwide. The objectives of this systematic review were to identify and evaluate scientific reports associated with ARB isolated from various street foods. "Preferred reporting items for systematic reviews and meta-analysis" (PRISMA) guidelines were followed. The bibliographic material covers a period from January 2015 to April 2024. Six electronic scientific databases were searched individually for full-text articles; only those papers that met the inclusion and exclusion criteria were selected. Seventeen papers were included in this systematic review. This study highlighted the wide distribution of ARB resistant to β-lactams and other antibiotics, posing significant health risks to consumers. High resistance levels were observed for antibiotics such as ampicillin, ceftriaxone, and tetracycline, while some antibiotics, such as ceftazidime, clavulanic acid, cefoperazone, cotrimoxazole, doxycycline, doripenem, fosfomycin, vancomycin, and piperacillin-tazobactam, demonstrated 100% susceptibility. The prevalence of ARB in street foods varied between 5.2% and 70.8% among different countries. The multiple resistance of various bacteria, including Escherichia coli, Staphylococcus, Salmonella, and Klebsiella, to multiple classes of antibiotics, as well as environmental factors contributing to the spread of antibiotic resistance (AR), emphasize the urgent need for comprehensive approaches and coordinated efforts to confront antimicrobial resistance (AMR) under the "One Health" paradigm.

Knowledge, Attitudes, Practices, and Risk Perception of Antimicrobial Use and Antimicrobial Resistance Among Dairy Farm Owners/Workers in Addis Ababa, Ethiopia

Introduction

Antimicrobial resistance (AMR) is one of the most significant global health threats to the public, animals, and the ecosystem. Inappropriate use of antibiotics in food animals is considered a major driver of AMR in humans. This study was conducted to assess the knowledge, attitude, practices, and risk perception (KAPP) of dairy farm owners/workers in Addis Ababa about antibiotic use and resistance.

Methods

A face-to-face interview using a structured questionnaire was conducted with 281 respondents in four selected subcities of Addis Ababa. The responses provided by each participant were recoded into a binary scale based on the mean score of each domain. Pearson chi-square was used to check the association between the KAPP and sociodemographic characteristics of the respondents and logistic regression analysis was done to explore the factors associated with KAPP.

Results

Overall, more than half of the surveyed dairy farm owners/workers had good knowledge (57.7%) and appropriate practice (53.0%), while less than half of the respondents showed desirable attitudes (47.7%) and positive risk perceptions (42.7%). The findings revealed a strong association between the respondents' KAPP and education and between knowledge and risk perception and farming experience.

Conclusion

This study found that continuous education of dairy farm owners/workers regarding antimicrobial usage and antimicrobial resistance in dairy farms will increase their awareness and perception of risk as well as motivate them to adopt desirable attitudes and appropriate practices, and consequently limit inappropriate use of antimicrobials leading to mitigating emergence of AMR.

Investigating antimicrobial resistance genes in Kenya, Uganda and Tanzania cattle using metagenomics

Antimicrobial resistance (AMR) is a growing problem in African cattle production systems, posing a threat to human and animal health and the associated economic value chain. However, there is a poor understanding of the resistomes in small-holder cattle breeds in East African countries. This study aims to examine the distribution of antimicrobial resistance genes (ARGs) in Kenya, Tanzania, and Uganda cattle using a metagenomics approach. We used the SqueezeMeta-Abricate (assembly-based) pipeline to detect ARGs and benchmarked this approach using the Centifuge-AMRplusplus (read-based) pipeline to evaluate its efficiency. Our findings reveal a significant number of ARGs of critical medical and economic importance in all three countries, including resistance to drugs of last resort such as carbapenems, suggesting the presence of highly virulent and antibiotic-resistant bacterial pathogens (ESKAPE) circulating in East Africa. Shared ARGs such as aph(6)-id (aminoglycoside phosphotransferase), tet (tetracycline resistance gene), sul2 (sulfonamide resistance gene) and cfxA_gen (betalactamase gene) were detected. Assembly-based methods revealed fewer ARGs compared to read-based methods, indicating the sensitivity and specificity of read-based methods in resistome characterization. Our findings call for further surveillance to estimate the intensity of the antibiotic resistance problem and wider resistome classification. Effective management of livestock and antibiotic consumption is crucial in minimizing antimicrobial resistance and maximizing productivity, making these findings relevant to stakeholders, agriculturists, and veterinarians in East Africa and Africa at large.

Tracking the extracellular and intracellular antibiotic resistance genes across whole year in wastewater of intensive dairy farm

Monitoring the annual variation of antibiotic resistance genes (ARGs) in livestock wastewater is important for determining the high-risk period of transfer and spread of animal-derived antibiotic resistance into the environment. However, the knowledge regarding the variation patterns of ARGs, especially intracellular ARGs (iARGs) and extracellular ARGs (eARGs), over time in livestock wastewater is still unclear. Herein, we conducted a year-round study to trace the profiles of ARGs at a Chinese-intensive dairy farm, focusing on the shifts observed in different months. The results showed significant differences in the composition and variation between iARGs and eARGs. Tetracycline, sulfonamide, and macrolide resistance genes were the major types of iARGs, while cfr was the major type of eARG. The environmental adaptations of the host bacteria determine whether ARGs appear as intracellular or extracellular forms. The total abundance of ARGs was higher from April to September, which can be attributed to the favorable climatic conditions for bacterial colonization and increased antibiotic administration during this period. Integron was found to be highly correlated with most iARGs, potentially playing a role in the presence of these genes within cells and their similar transmission patterns in wastewater. The intracellular and extracellular bacterial communities were significantly different, primarily because of variations in bacterial adaptability to the high salt and anaerobic environment. The intracellular co-occurrence network indicated that some dominant genera in wastewater, such as Turicibacter, Clostridium IV, Cloacibacillus, Subdivision5_genera_incertae_sedis, Saccharibacteria_genera_incertae_sedis and Halomonas, were potential hosts for many ARGs. To the best of our knowledge, this study demonstrates, for the first time, the annual variation of ARGs at critical points in the reuse of dairy farm wastewater. It also offers valuable insights into the prevention and control of ARGs derived from animals.

Magnetized algae catalyst by endogenous N to effectively trigger peroxodisulfate activation for ultrafast degraded sulfathiazole: Radical evolution and electron transfer

An innovative Fe-N co-coupled catalyst MN-2 was prepared from waste spirulina by co-pyrolysis as a highly active carbon-based catalyst for the activation of peroxydisulfate (PDS) for the degradation of sulfathiazole (ST). The protein-rich raw material Spirulina provided sufficient N during the pyrolysis process, thus achieving N doping without an additional nitrogen source, optimizing the interlayer structure of the biochar material and effectively inhibiting the leaching of the ligand metal Fe. MN-2 showed highly efficient catalytic activity for peroxydisulfate (PDS), with a degradation efficiency of 100% for ST within 30 min and a kinetic constant (kobs) reached 0.306 min-1, benefiting from the excellent adsorption ability of MN-2 forming MN-2-PDS* complexes and the electron transfer process generated by Fe3+ and Fe2+ cycling, oxygen-containing functional groups. The effects of PDS dosage, initial pH and coexisting anions on the oxidation process were also investigated. Free radical quenching, electron paramagnetic resonance and electrochemical measurements were employed to explain the hydroxyl (·OH) and sulfate (SO4·-) as the dominant active species and the electron transfer effect on the removal of ST. MN-2 maintained a ST removal rate of 84% after four recycling experiments, showing a high reusability performance. This work provides a simple way to prepare magnetized N-doped biochar, a novel catalyst (MN-2) for efficient activation of PDS for ST degradation, and a feasible method for removing sulfanilamide antibiotics in water environment.

The Impact of Bamboo Consumption on the Spread of Antibiotic Resistance Genes in Giant Pandas

The spread of antibiotic resistance genes (ARGs) in the environment exacerbates the contamination of these genes; therefore, the role plants play in the transmission of resistance genes in the food chain requires further research. Giant pandas consume different bamboo parts at different times, which provides the possibility of investigating how a single food source can affect the variation in the spread of ARGs. In this study, metagenomic analysis and the Comprehensive Antibiotic Resistance Database (CARD) database were used to annotate ARGs and the differences in gut microbiota ARGs during the consumption of bamboo shoots, leaves, and culms by captive giant pandas. These ARGs were then compared to investigate the impact of bamboo part consumption on the spread of ARGs. The results showed that the number of ARGs in the gut microbiota of the subjects was highest during the consumption of bamboo leaves, while the variety of ARGs was highest during the consumption of shoots. Escherichia coli, which poses a higher risk of ARG dissemination, was significantly higher in the leaf group, while Klebsiella, Enterobacter, and Raoultella were significantly higher in the shoot group. The ARG risk brought by bamboo shoots and leaves may originate from soil and environmental pollution. It is recommended to handle the feces of giant pandas properly and regularly monitor the antimicrobial and virulence genes in their gut microbiota to mitigate the threat of antibiotic resistance.

Investigation of milk microbiota of healthy and mastitic Sahiwal cattle

BACKGROUND

Sahiwal cattle is an indigenous cattle breed of Pakistan and mastitis is one of the major problems faced by Sahiwal cattle which hinders its production potential. The study was designed to investigate the milk microbiota of healthy and mastitic Sahiwal cattle as part of a multistep project to develop probiotics for the mitigation and control of mastitis. Milk samples of Sahiwal cattle (healthy clinical mastitis and subclinical mastitis) reared under similar husbandry and management practices were processed for 16S rRNA gene base metagenomics analysis.

RESULTS

Results revealed that Proteobacteria were dominant in the healthy group and subclinical mastitis group (56.48% and 48.77%, respectively) as compared to the clinical mastitis group (2.68%). In contrast, Firmicutes were abundant in the clinical mastitis group (64%) as compared to the healthy and subclinical mastitis groups (15.87% and 38.98%, respectively). Dominant species assigned in the healthy group were Ignavibacterium album, Novosphingobium capsulatum, Akkermansia muciniphila and Lactobacillus fermentum.The clinical mastitis group was dominated by Streptococcus dysgalactiae and Corynebacterium bovis, while subclinical mastitis group included Lactobacillus fermentum and uncultured acidobacteriales and Akkermansia muciniphila as dominant species. Alpha diversity indices showed higher microbial diversity in the healthy group compared to the clinical and sub-clinical mastitis groups.

CONCLUSION

It is concluded that the milk microbiota of healthy sahiwal cattle has higher diversity and dominant taxa in the different groups may be used as signature microbes for mastitis susceptibility. Akkermansia muciniphila is one of candidate specie that was identified and may be used for development of probiotics.

A Comprehensive Study of Historical Detection Data for Pathogen Isolates from U.S. Cattle

Foodborne pathogens pose substantial health hazards and result in considerable economic losses in the U.S. Fortunately, the National Center for Biotechnology Information Pathogen Detection Isolates Browser (NPDIB) provides valuable access to antimicrobial resistance (AMR) genes and antimicrobial assay data. This study aimed to conduct the first comprehensive investigation of AMR genes in pathogens isolated from U.S. cattle over the past decade, driven by the urgent need to address the dangers of AMR specifically originating in pathogens isolated from U.S. cattle. In this study, around 28,000 pathogen isolate samples were extracted from the NPDIB and then analyzed using multivariate statistical methods, mainly principal component analysis (PCA) and hierarchical clustering (H-clustering). These approaches were necessary due to the high dimensions of the raw data. Specifically, PCA was utilized to reduce the dimensions of the data, converting it to a two-dimensional space, and H-clustering was used to better identify the differences among data points. The findings from this work highlighted Salmonella enterica and Escherichia coli as the predominant pathogens among the isolates, with E. coli being the more concerning pathogen due to its increasing prevalence in recent years. Moreover, tetracycline was observed as the most commonly resistant antimicrobial, with the resistance genes mdsA, mdsB, mdtM, blaEC, and acrF being the most prevalent in pathogen isolates from U.S. cattle. The occurrence of mdtM, blaEC, acrF, and glpT_E448k showed an increase in pathogens isolated from U.S. cattle in recent years. Furthermore, based on the data collected for the locations of AMR cases, Texas, California, and Nebraska were the major areas carrying major AMR genes or antimicrobials with detected resistance. The results from this study provide potential directions for targeted interventions to mitigate pathogens' antimicrobial resistance in U.S. cattle.

Carbapenem resistance in Enterobacterales from agricultural, environmental and clinical origins: South Africa in a global context

Carbapenem agents are regarded as last-resort antibiotics, however, bacterial resistance towards carbapenems has been reported in both clinical and agricultural settings worldwide. Carbapenem resistance, defined as the resistance of a bacteria towards one or more carbapenem drugs, can be mediated in either of, or a combination of, three mechanisms-although, the mechanism mediated through the production of carbapenemases (β-lactamases that are able to enzymatically degrade carbapenems) is of most significance. Of particular concern is the occurrence of carbapenemase producing Enterobacterales (CPE), with literature describing a dramatic increase in resistance globally. In South Africa, increases of carbapenemase activity occurring in Enterobacter species, Klebsiella pneumoniae, Acinetobacter baumannii and Pseudomonas aeruginosa have recently been reported. CPE can also be found in agricultural environments, as global studies have documented numerous instances of CPE presence in various animals such as pigs, cattle, seafood, horses and dogs. However, most reports of CPE occurrence in agricultural settings come from Northern America, Europe and some parts of Asia, where more extensive research has been conducted to understand the CPE phenomenon. In comparison to clinical data, there are limited studies investigating the spread of CPE in agricultural settings in Africa, highlighting the importance of monitoring CPE in livestock environments and the food chain. Further research is necessary to uncover the true extent of CPE dissemination in South Africa. This review will discuss the phenomenon of bacterial antibiotic resistance (ABR), the applications of the carbapenem drug and the occurrence of carbapenem resistance globally.

Antimicrobial Resistance and Clonal Lineages of Escherichia coli from Food-Producing Animals

Escherichia coli are one of the most important pathogenic bacteria readily found in the livestock and widely studied as an indicator that carries drug-resistant genes between humans, animals, and the environment. The use of antimicrobials in the food chain, particularly in food-producing animals, is recognized as a significant contributor to the development and spread of antimicrobial resistance (AMR) and resistance genes can be transferred from the farm through the food-chain. The objective of this review is to highlight the background of the antimicrobials use in food-producing animals, more specifically, to study clonal lineages and the resistance profiles observed in E. coli, as well as in extended spectrum beta-lactamases (ESBL) producing E. coli, in a set of food-production animals with greater relevance in food consumption, such as pigs, poultry, cattle, fish farming and rabbits. Regarding the prevalence of ESBL-producing E. coli among farm animals, high-to-moderate prevalence was observed, and the highest resistance rates to tetracycline and ampicillin was detected in different farms in all geographic regions. Worldwide pandemic clones and high-risk zoonotic E. coli clones have been identified in most food-producing animals, and some of these clones are already disseminated in different niches, such as the environment and humans. A better understanding of the epidemiology of E. coli and ESBL-producing E. coli in livestock is urgently needed. Animal production is one of the major causes of the antibiotic resistance problem worldwide and a One Health approach is needed.

The dynamics and transmission of antibiotic resistance associated with plant microbiomes

Antibiotic resistance genes (ARGs) have been widely found and studied in soil and water environments. However, the propagation of ARGs in plant microbiomes has attracted insufficient attention. Plant microbiomes, especially the rhizosphere microorganisms, are closely connected with water, soil, and air, which allows ARGs to spread widely in ecosystems and pose a threat to human health after entering the human body with bacteria. Therefore, it is necessary to deeply understand and explore the dynamics and the transmission of ARGs in rhizosphere microorganisms and endophytes of plants. In this review, the transmission and influencing factors of ARGs in the microorganisms associated with plants, especially the influence of root exudates on plant microbiomes, are analyzed. Notably, the role of intrinsic genes of plants in determining root exudates and their potential effects on ARGs are proposed and analyzed. The important role of phyllosphere microorganisms and endophytes in the transmission of ARGs and co-resistance of antibiotics and other substances are also emphasized. The proliferation and transmission of ARGs associated with plant microbiomes addressed in this review is conducive to revealing the fate of ARGs in plant microorganisms and alleviating ARG pollution.

Effect and mechanism of simultaneous cadmium-tetracycline removal by a self-assembled microbial-photocatalytic coupling system

Electrochemical bacteria Shewanella oneidensis MR-4 (MR-4) was used to biologically generate cadmium sulfide (bio-CdS) nanocrystals and construct a self-assembled intimately coupled photocatalysis-biodegradation system (SA-ICPB) to remove cadmium (Cd) and tetracycline hydrochloride (TCH) from wastewater. The characterization using EDS, TEM, XRD, XPS, and UV-vis confirmed the successful CdS bio-synthesis and its visible-light response capacity (520 nm). 98.4% of Cd²⁺ (2 mM) was removed during bio-CdS generation within 30 min. The electrochemical analysis confirmed the photoelectric response capability of the bio-CdS as well as its photocatalytic efficiency. Under visible light, SA-ICPB entirely eliminated TCH (30 mg/L). In 2 h, 87.2% and 43.0% of TCH were removed separately with and without oxygen. 55.7% more chemical oxygen demand (COD) was removed with oxygen participation, indicating the degradation intermediates elimination by SA-ICPB required oxygen participation. Biodegradation dominated the process under aerobic circumstances. Electron paramagnetic resonance analysis indicated that h⁺ and ·O₂^- played a decisive role in photocatalytic degradation. Mass spectrometry analysis proved that TCH was dehydrated, dealkylated, and ring-opened before mineralizing. In conclusion, MR-4 can spontaneously generate SA-ICPB and rapidly-deeply eliminate antibiotics by coupling photocatalytic and microbial degradation. Such an approach was efficient for the deep degradation of persistent organic pollutants with antimicrobial properties.

An Overview of the Public Health Challenges in Diagnosing and Controlling Human Foodborne Pathogens

Pathogens found in food are believed to be the leading cause of foodborne illnesses; and they are considered a serious problem with global ramifications. During the last few decades, a lot of attention has been paid to determining the microorganisms that cause foodborne illnesses and developing new methods to identify them. Foodborne pathogen identification technologies have evolved rapidly over the last few decades, with the newer technologies focusing on immunoassays, genome-wide approaches, biosensors, and mass spectrometry as the primary methods of identification. Bacteriophages (phages), probiotics and prebiotics were known to have the ability to combat bacterial diseases since the turn of the 20th century. A primary focus of phage use was the development of medical therapies; however, its use quickly expanded to other applications in biotechnology and industry. A similar argument can be made with regards to the food safety industry, as diseases directly endanger the health of customers. Recently, a lot of attention has been paid to bacteriophages, probiotics and prebiotics most likely due to the exhaustion of traditional antibiotics. Reviewing a variety of current quick identification techniques is the purpose of this study. Using these techniques, we are able to quickly identify foodborne pathogenic bacteria, which forms the basis for future research advances. A review of recent studies on the use of phages, probiotics and prebiotics as a means of combating significant foodborne diseases is also presented. Furthermore, we discussed the advantages of using phages as well as the challenges they face, especially given their prevalent application in food safety.

Cephalosporins as key lead generation beta-lactam antibiotics

Abstract

Antibiotics are antibacterial compounds that interfere with bacterial growth, without harming the infected eukaryotic host. Among the clinical agents, beta-lactams play a major role in treating infected humans and animals. However, the ever-increasing antibiotic resistance crisis is forcing the pharmaceutical industry to search for new antibacterial drugs to combat a range of current and potential multi-resistant bacterial pathogens. In this review, we provide an overview of the development, innovation, and current status of therapeutic applications for beta-lactams with a focus on semi-synthetic cephalosporins. Cephalosporin C (CPC), which is a natural secondary metabolite from the filamentous fungus Acremonium chrysogenum, plays a major and demanding role in both producing modern antibiotics and developing new ones. CPC serves as a core compound for producing semi-synthetic cephalosporins that can control infections with different resistance mechanisms. We therefore summarize our latest knowledge about the CPC biosynthetic pathway and its regulation in the fungal host. Finally, we describe how CPC serves as a key lead generation source for the in vitro and better, in vivo synthesis of 7-aminocephalosporanic acid (7-ACA), the major core compound for the pharmaceutical synthesis of current and future semi-synthetic cephalosporins.

Key points

•Latest literature on cephalosporin generations

•Biotechnical production of cephalosporins

•In vivo production of 7-ACA

Evaluación de la administración de medicamentos veterinarios en hatos lecheros de quince municipios de Cundinamarca, Colombia

Objetivo Evaluar el conocimiento en el uso de Medicamentos de Uso Veterinario (MUV) de los productores ganaderos y personal involucrado en Bogotá y municipios aledaños. Métodos Se realizó un estudio de corte transversal a través de entrevistas a operarios y productores ganaderos de una muestra de 30 hatos lecheros localizados en 15 municipios cerca de Bogotá, Cundinamarca. Resultados Se identificó la implementación de prácticas para la administración de MUV, incluyendo parámetros que influencian su administración y conocimientos en las personas que los prescriben y administran. Se encontró que los medicamentos de mayor frecuencia fueron los antimicrobianos con 60,7%, entre los cuales se destaca el uso de penicilina y oxitetraciclina. Los MUV inyectables (parenterales) fueron las formas más frecuentes de aplicación con un 64,7%. Se identificaron 251 MUV en los hatos lecheros, de los cuales el 81,3% están compuestos por principios activos que requieren tiempo de retiro en leche y carne. Se destaca el rol del mayordomo en el cuidado animal a nivel diagnóstico y administración del tratamiento. Conclusión El presente estudio sugiere que el uso de MUV es implementado empíricamente en producciones lecheras y podría contribuir a mediano y largo plazo a la emergencia de cepas con resistencia a MUV.