Spread Of Antibiotic-resistant Bacteria Research Articles

Characterisation of microbial communities and quantification of antibiotic resistance genes in Italian wastewater treatment plants using 16S rRNA sequencing and digital PCR

The spread of antibiotic resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in humans, animals and environment is a growing threat to public health. Wastewater treatment plants (WWTPs) are crucial in mitigating the risk of environmental contamination by effectively removing contaminants before discharge. However, the persistence of ARB and ARGs even after treatment is a challenge for the management of water system.To comprehensively assess antimicrobial resistance dynamics, we conducted a one-year monitoring study in three WWTPs in central Italy, both influents and effluents. We used seasonal sampling to analyze microbial communities by 16S rRNA, as well as to determine the prevalence and behaviour of major ARGs (sul1, tetA, blaTEM, blaOXA-48, blaCTX-M-1 group, blaKPC) and the class 1 Integron (int1). Predominant genera included in order: Arcobacter, Acinetobacter, Flavobacterium, Pseudarcobacter, Bacteroides, Aeromonas, Trichococcus, Cloacibacterium, Pseudomonas and Streptococcus. A higher diversity of bacterial communities was observed in the effluents compared to the influents. Within these communities, we also identified bacteria that may be associated with antibiotic resistance and pose a significant threat to human health. The mean concentrations (in gene copies per liter, gc/L) of ARGs and int1 in untreated wastewater (absolute abundance) were as follows: sul1 (4.1 × 109), tetA (5.2 × 108), blaTEM (1.1 × 108), blaOXA-48 (2.1 × 107), blaCTX-M-1 group (1.1 × 107), blaKPC (9.4 × 105), and int1 (5.5 × 109). The mean values in treated effluents showed reductions ranging from one to three log. However, after normalizing to the 16S rRNA gene (relative abundance), it was observed that in 37.5 % (42/112) of measurements, the relative abundance of ARGs increased in effluents compared to influents. Furthermore, correlations were identified between ARGs and bacterial genera including priority pathogens. This study improves our understanding of the dynamics of ARGs and provides insights to develop more effective strategies to reduce their spread, protecting public health and preserving the future efficacy of antibiotics.

Mariculture waters as yet another hotbed for the creation and transfer of new antibiotic-resistant pathogenome

With the rapid growth of aquaculture globally, large amounts of antibiotics have been used to treat aquatic disease, which may accelerate induction and spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) in aquaculture environments. Herein, metagenomic and 16S rRNA analyses were used to analyze the potentials and co-occurrence patterns of pathogenome (culturable and unculturable pathogens), antibiotic resistome (ARGs), and mobilome (mobile genetic elements (MGEs)) from mariculture waters near 5000 km coast of South China. Total 207 species of pathogens were identified, with only 10 culturable species. Furthermore, more pathogen species were detected in mariculture waters than those in coastal waters, and mariculture waters were prone to become reservoirs of unculturable pathogens. In addition, 913 subtypes of 21 ARG types were also identified, with multidrug resistance genes as the majority. MGEs including plasmids, integrons, transposons, and insertion sequences were abundantly present in mariculture waters. The co-occurrence network pattern between pathogenome, antibiotic resistome, and mobilome suggested that most of pathogens may be potential multidrug resistant hosts, possibly due to high frequency of horizontal gene transfer. These findings increase our understanding of mariculture waters as reservoirs of antibiotic resistome and mobilome, and as yet another hotbed for creation and transfer of new antibiotic-resistant pathogenome.

Ligand-Free Silver Nanoparticles: An Innovative Strategy against Viruses and Bacteria.

The spread of antibiotic-resistant bacteria and the rise of emerging and re-emerging viruses in recent years constitute significant public health problems. Therefore, it is necessary to develop new antimicrobial strategies to overcome these challenges. Herein, we describe an innovative method to synthesize ligand-free silver nanoparticles by Pulsed Laser Ablation in Liquid (PLAL-AgNPs). Thus produced, nanoparticles were characterized by total X-ray fluorescence, zeta potential analysis, transmission electron microscopy (TEM), and nanoparticle tracking analysis (NTA). A 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was performed to evaluate the nanoparticles' cytotoxicity. Their potential was evaluated against the enveloped herpes simplex virus type 1 (HSV-1) and the naked poliovirus type 1 (PV-1) by plaque reduction assays and confirmed by real-time PCR and fluorescence microscopy, showing that nanoparticles interfered with the early stage of infection. Their action was also examined against different bacteria. We observed that the PLAL-AgNPs exerted a strong effect against both methicillin-resistant Staphylococcus aureus (S. aureus MRSA) and Escherichia coli (E. coli) producing extended-spectrum β-lactamase (ESBL). In detail, the PLAL-AgNPs exhibited a bacteriostatic action against S. aureus and a bactericidal activity against E. coli. Finally, we proved that the PLAL-AgNPs were able to inhibit/degrade the biofilm of S. aureus and E. coli.

Impact of the ´Alforja Educativa’ on Ecuadorian schoolchildren’s knowledge of bacteria, antibiotics, and antibiotic resistance, a pretest-posttest study

BackgroundWidespread use of antibiotics disrupts the balance in the microbial world and promotes development and spread of antibiotic resistant bacteria. Educational initiatives are important as part of strategies to mitigate antibiotic resistance. The Alforja Educativa is an innovative educational program developed in Ecuador with the aim to teach schoolchildren about antibiotic use and antibiotic resistance. The program places antibiotic resistance within a broader frame of health, well-being, and ecological awareness, highlighting the importance to maintain balance in the microbial world. The objective of this study was to evaluate the effect of the Alforja Educativa on knowledge about bacteria, antibiotics and antibiotic resistance amongst fifth and sixth grade Ecuadorian schoolchildren.MethodsThis pretest-posttest intervention study was conducted between April and June 2017 and comprised fifth and sixth grade schoolchildren from 20 schools in Cuenca, Ecuador, recruited by purposeful sampling. The Alforja Educativa was implemented over twelve 80-minute sessions by trained university students. Schoolchildren’s knowledge was assessed before and after participation in the educational program using a structured questionnaire. A mean total score, the proportion of correct responses for each individual knowledge-based question, as well as correct responses for each of the multiple-choice options of the knowledge-based questions were calculated for the pretest and posttest.ResultsA total of 1,257 schoolchildren participated in the Alforja Educativa program, of which 980 (78%) completed both the pretest and posttest. Overall, the mean total knowledge score increased from pretest to posttest (2.58/7.00 vs. 3.85/7.00; CI = 0.5, p < 0.001). After participation in the program, the proportion of schoolchildren that correctly identified that bacteria can be both good and bad increased from 35.0 to 84.3%. In addition, scores increased for correctly identifying the meaning of antibiotic resistance (37.4–72.0%); how to prevent antibiotic resistance (63.2–74.6%); and for identifying the meaning of self-medication (46.3–54.3%).ConclusionThe Alforja Educativa was effective in improving the knowledge of participating schoolchildren about concepts related to bacteria, antibiotics and antibiotic resistance. The holistic perspective taken to explain the complex relationship between humans and bacteria, as well as the effect of antibiotics on the microbial world, may help provide a foundation for more sustainable antibiotic use.

Importation trends in antibiotics for veterinary use in Rwanda: A retrospective study between 2019 and 2021.

Estimating antibiotic consumption in animals is fundamental to guiding decision-making and research on controlling the emergence and spread of antibiotic-resistant bacteria in humans, animals, and the environment. This study aimed to establish importation trends of antibiotics for veterinary use in Rwanda between 2019 and 2021. Data was collected from the Rwanda Food and Drugs Authority's database. Quantities of imported antibiotic active ingredients were computed using the information extracted from the issued import licenses. These quantities were subsequently adjusted per animal biomass. In total, 35,291.4 kg of antibiotics were imported into Rwanda between 2019 and 2021, with an annual mean of 11,763.8 ± 1,486.9 kg. The adjustment of imported quantities of antibiotics per animal biomass revealed that 29.1 mg/kg, 24.3 mg/kg, and 30.3 mg/kg were imported in 2019, 2020, and 2021 respectively. A slight but not statistically significant decline in antibiotic importation was noted in 2020 (p-value = 0.547). Most of the imported antibiotics were indicated to be used in food-producing animals (35,253.8 kg or 99.9% of the imported antibiotics). Tetracyclines (17,768.6 kg or 50.3%), followed by sulfonamides (7,865.0 kg or 22.3%) and aminoglycosides (4,071.1 kg or 11.5%), were the most imported antibiotics over the studied period. It was noted that 78.9% of the imported antibiotics were categorized as highly important antimicrobials for human medicine. This study established a generalized overview of the importation of antibiotics for veterinary use in Rwanda. These results can serve as guidance for the control of antibiotic misuse. They can be used to make a correlation between antibiotic importation, antibiotic consumption, and the occurrence of antibiotic resistance in the country.

Knowledge, Attitudes, and Practices of Parents in the Use of Antibiotics: A Case Study in a Mexican Indigenous Community

The rise and spread of antibiotic-resistant bacteria have become a global health problem. At the community level, bacterial resistance has been linked to antibiotic misuse practices. These practices are related to social factors such as education level, poverty, ethnicity, and use of traditional medicine. Through a survey, this study aims to analyse the knowledge, attitudes, and practices (KAP) of antimicrobial use, in an indigenous community in the south of Oaxaca, Mexico. It was observed that the population had a low socioeconomic profile, poor access to healthcare services, low academic level, little knowledge of antibiotics, the use of traditional medicine, and proper attitudes and practices regarding antibiotics use. Therefore, social factors are related to bacterial resistance only if they make the population prone to the use of antimicrobials. Lack of medical access and cultural factors drives this population to use ancestral alternatives such traditional medicine to treat conditions that in other contexts could be treated with antibiotics. This is an example of how the population can reduce the consumption of antimicrobials in infections if they have a reliable alternative that improves their symptoms.

Solar-driven photocatalytic removal of anti-microbial drugs – Comparison of the efficiency of selected photocatalysts

The growing interest in the environmental contamination by antibiotics is observed due to their adverse effects on aquatic fauna, formation and spread of antibiotic-resistant bacteria, and antibiotic-resistant genes. Heterogeneous photocatalysis has been found a promising method to remove these recalcitrant micropollutants from the broadly understood aquatic environment. The most efficient functional materials for photocatalytic applications are nano-sized semiconductor oxides. ZnO is recently mentioned to be an alternative to TiO2, a commonly used photocatalyst, for environmental applications, but there is still a lack of information on its operation efficiency, especially in more complex matrices. This study aimed to compare the efficiency of TiO2-P25 and ZnO in the removal of selected veterinary sulfonamides (SAs), namely: sulfadiazine (SDZ), sulfamethoxazole (SMX), and sulfamethazine (SMT) from distilled water (DW), river water (RW), and municipal wastewater effluent (MWWE). TiO2-P25 has been found the most efficient photocatalyst to remove target SAs from DW, while in the case of RW and MWWE ZnO was more efficient in the degradation of studied antibiotics. The removal efficiency of the studied SAs decreased in the following order: SMT>SDZ>SMX. Doubling the photocatalysts concentration increased the efficiency of SAs degradation, but the final effect depends on the complexity of the matrix used.

Investigating the Gut Microbiome's Role in Antibiotic Resistance in Companion Animals

Antibiotic resistance poses a growing concern in veterinary medicine, jeopardizing animal health and public health. Overuse and misuse of antibiotics have led to the emergence of bacteria resistant to these medications, rendering them ineffective. This overview screening article explores the potential link between disruptions in the gut microbiome and the rise of antibiotic-resistant bacteria in companion animals. The gut microbiome, a complex ecosystem of microorganisms residing in the digestive tract, plays a crucial role in maintaining health. However, antibiotic use can disrupt this delicate balance, leading to microbiome dysbiosis. This imbalance creates an opportunity for antibiotic-resistant bacteria to flourish. These resistant bacteria, often harboring genes allowing them to evade antibiotic effects, can then spread within the gut and potentially pose a threat to the effectiveness of future antibiotic treatments. Understanding the microbiome-resistance connection is essential for developing strategies to combat antibiotic resistance. Outlining a research approach to investigate this link, employing methods like animal models, microbiome analysis through 16S rRNA gene sequencing, and antibiotic resistance profiling would be reviewed. By elucidating the mechanisms by which microbiome disruptions contribute to the emergence of resistant bacteria, we can pave the way for novel interventions. These interventions could include the use of probiotics, prebiotics, or fecal microbiota transplantation to restore a healthy gut microbiome and limit the selection and spread of antibiotic-resistant bacteria. By harnessing the power of the gut microbiome, we can ensure the continued effectiveness of antibiotics in treating bacterial infections in companion animals and safeguard animal health and well-being.

Polyhexamethylene biguanide promotes adaptive cross-resistance to gentamicin in Escherichia coli biofilms.

Antimicrobial resistance is a critical public health issue that requires a thorough understanding of the factors that influence the selection and spread of antibiotic-resistant bacteria. Biocides, which are widely used in cleaning and disinfection procedures in a variety of settings, may contribute to this resistance by inducing similar defense mechanisms in bacteria against both biocides and antibiotics. However, the strategies used by bacteria to adapt and develop cross-resistance remain poorly understood, particularly within biofilms -a widespread bacterial habitat that significantly influences bacterial tolerance and adaptive strategies. Using a combination of adaptive laboratory evolution experiments, genomic and RT-qPCR analyses, and biofilm structural characterization using confocal microscopy, we investigated in this study how Escherichia coli biofilms adapted after 28 days of exposure to three biocidal active substances and the effects on cross-resistance to antibiotics. Interestingly, polyhexamethylene biguanide (PHMB) exposure led to an increase of gentamicin resistance (GenR) phenotypes in biofilms formed by most of the seven E. coli strains tested. Nevertheless, most variants that emerged under biocidal conditions did not retain the GenR phenotype after removal of antimicrobial stress, suggesting a transient adaptation (adaptive resistance). The whole genome sequencing of variants with stable GenR phenotypes revealed recurrent mutations in genes associated with cellular respiration, including cytochrome oxidase (cydA, cyoC) and ATP synthase (atpG). RT-qPCR analysis revealed an induction of gene expression associated with biofilm matrix production (especially curli synthesis), stress responses, active and passive transport and cell respiration during PHMB exposure, providing insight into potential physiological responses associated with adaptive crossresistance. In addition, confocal laser scanning microscopy (CLSM) observations demonstrated a global effect of PHMB on biofilm architectures and compositions formed by most E. coli strains, with the appearance of dense cellular clusters after a 24h-exposure. In conclusion, our results showed that the PHMB exposure stimulated the emergence of an adaptive cross-resistance to gentamicin in biofilms, likely induced through the activation of physiological responses and biofilm structural modulations altering gradients and microenvironmental conditions in the biological edifice.

Detection of chromosome-mediated blaNDM-1-carrying Aeromonas spp. in the intestinal contents of fresh water river fish in Ho Chi Minh City, Vietnam

The spread of antibiotic-resistant bacteria is a global problem that should be addressed through the perspective of the “one health” concept. The purpose of this study was to determine the contamination rate of antibiotic-resistant Aeromonas spp. in fresh water river fish purchased from a fish market in Vietnam. We then defined the pattern of antibiotic resistance to assess antibiotic-resistant contamination. Antibiotic-resistant Aeromonas spp. were detected in the intestinal contents of 32 of 80 fish. blaNDM-1 was detected in seven strains. Extended-spectrum β-lactamase and AmpC β-lactamase-related genes were detected in 28 strains, including blaCTX-M-55, blaCTX-M-15, blaCTX-M-1, and blaDHA,blaFOX, and blaMOX. The blaNDM-1 detected in the seven Aeromonas spp. strains were found chromosomally. This finding suggests that the blaNDM gene is stable in the natural environment and may spread widely into animals and humans via Aeromonas spp. with a transposon. Our results suggest the importance of continuing to monitor carbapenemase genes in Aeromonas spp. to evaluate the possibility that they may spread in other Enterobacterales, and to elucidate the mechanism of spread.

A case for the importance of following antibiotic resistant bacteria throughout the soil food web.

It is necessary to complement next-generation sequencing data on the soil resistome with theoretical knowledge provided by ecological studies regarding the spread of antibiotic resistant bacteria (ARB) in the abiotic and, especially, biotic fraction of the soil ecosystem. Particularly, when ARB enter agricultural soils as a consequence of the application of animal manure as fertilizer, from a microbial ecology perspective, it is important to know their fate along the soil food web, that is, throughout that complex network of feeding interactions among members of the soil biota that has crucial effects on species richness and ecosystem productivity and stability. It is critical to study how the ARB that enter the soil through the application of manure can reach other taxonomical groups (e.g., fungi, protists, nematodes, arthropods, earthworms), paying special attention to their presence in the gut microbiomes of mesofauna-macrofauna and to the possibilities for horizontal gene transfer of antibiotic resistant genes.

Deciphering the pivotal role of people with high-frequency occupational animal exposure in antibiotic resistance transmission between humans and animals.

The spread of antibiotic-resistant bacteria (ARB) and antibiotic resistance genes (ARGs) among humans and food-producing animals has been widely reported. However, the transmission routes and associated risk factors remain incompletely understood. Here, we used commensal Escherichia coli bacteria strains from faeces of pigs and local citizens [HEG: high exposure group (pig breeders, butchers or restaurant chefs) and LEG: low exposure group (other occupations)] to explore the dynamics of ARB and ARG transmission between animals and humans. Most ARGs (96%) present in pigs were shared with humans. Carriage rates of the shared ARGs suggest two transmission patterns among pigs, the HEG and LEG: one pattern was highest in pigs, gradually decreasing in the HEG and LEG (e.g. floR and cmlA1); the other pattern was increasing from pigs to the HEG but then decreasing in the LEG (e.g. mcr-1.1). Carriage rates of the HEG were higher than in the LEG in both patterns, implicating the HEG as a crucial medium in transmitting ARB and ARGs between food-producing animals and humans. Moreover, frequent inter/intragroup transmission via strains, plasmids and/or mobile elements was evident. Carriage of mcr-1.1 on human-gut-prevalent plasmids possibly promoted its enrichment in the HEG. The HEG is a crucial factor in transmitting ARB and ARGs between food-producing animals and humans. Rational measures to contain the risks of occupational exposure are urgently needed to keep dissemination of antibiotic resistance in check and safeguard public health.

Use of lactulose as a prebiotic in laying hens: its effect on growth, egg production, egg quality, blood biochemistry, digestive enzymes, gene expression and intestinal morphology

BackgroundThe rising popularity of eggs as an alternative source of protein to meat has led to significant increase in egg consumption over the past decade. To meet the increasing demand for eggs, poultry farmers have used antibiotics to treat infections and, to some extent, promote growth and egg production in raising layer. However, the emergence and global spread of antibiotic resistant bacteria has now necessitated antibiotic-free poultry farming. As alternatives to antibiotics, prebiotics are feed additives that can be used to improve the growth and laying performance of poultry which positively impacts their performance and general health. In this study we evaluated the effect of lactulose, formulated as Vetelact, on body weight, egg production, egg quality, blood biochemical parameters and expression of genes associated with reproductive performance in laying hens.ResultsVetelact supplementation improved egg weight, egg production as well as egg quality. Following Vetalact supplementation, the levels of total bilirubin, total protein, globulin and phosphorus were increased, while the activities of alkaline phosphatase and lipase enzymes were increased compared to control. Vetelact at 0.10 ml/kg body weight upregulated OCX-36, OVAL, CALB1, OC-116, OCX-32 and IL8 transcripts while downregulating the transcription of Gal-10, PENK and AvBD9. At this optimal inclusion rate of Vetalect, histomorphologic analyses of intestinal tissue showed increased villi length with more goblet cell distribution and obvious mucus covering a surface, increase in the depth of intestinal crypts produce digestive enzymes, as well as more developed muscle layer that promote improved nutrient absorption.ConclusionVetelact at a dose of 0.10 ml/ kg body weight was effective in improving productive performance of laying hens. Adding lactulose (0.10 ml/ kg body weight) to layer diet is recommended to promote growth and improve egg laying performance in antibiotics-free poultry production.

Risk factors for extended-spectrum beta-lactamase (ESBL)-producing E. coli carriage among children in a food animal-producing region of Ecuador: A repeated measures observational study.

The spread of antibiotic-resistant bacteria may be driven by human-animal-environment interactions, especially in regions with limited restrictions on antibiotic use, widespread food animal production, and free-roaming domestic animals. In this study, we aimed to identify risk factors related to commercial food animal production, small-scale or "backyard" food animal production, domestic animal ownership, and practices related to animal handling, waste disposal, and antibiotic use in Ecuadorian communities. We conducted a repeated measures study from 2018 to 2021 in 7 semirural parishes of Quito, Ecuador to identify determinants of third-generation cephalosporin-resistant E. coli (3GCR-EC) and extended-spectrum beta-lactamase E. coli (ESBL-EC) in children. We collected 1,699 fecal samples from 600 children and 1,871 domestic animal fecal samples from 376 of the same households at up to 5 time points per household over the 3-year study period. We used multivariable log-binomial regression models to estimate relative risks (RR) of 3GCR-EC and ESBL-EC carriage, adjusting for child sex and age, caregiver education, household wealth, and recent child antibiotic use. Risk factors for 3GCR-EC included living within 5 km of more than 5 commercial food animal operations (RR: 1.26; 95% confidence interval (CI): 1.10, 1.45; p-value: 0.001), household pig ownership (RR: 1.23; 95% CI: 1.02, 1.48; p-value: 0.030) and child pet contact (RR: 1.23; 95% CI: 1.09, 1.39; p-value: 0.001). Risk factors for ESBL-EC were dog ownership (RR: 1.35; 95% CI: 1.00, 1.83; p-value: 0.053), child pet contact (RR: 1.54; 95% CI: 1.10, 2.16; p-value: 0.012), and placing animal feces on household land/crops (RR: 1.63; 95% CI: 1.09, 2.46; p-value: 0.019). The primary limitations of this study are the use of proxy and self-reported exposure measures and the use of a single beta-lactamase drug (ceftazidime with clavulanic acid) in combination disk diffusion tests for ESBL confirmation, potentially underestimating phenotypic ESBL production among cephalosporin-resistant E. coli isolates. To improve ESBL determination, it is recommended to use 2 combination disk diffusion tests (ceftazidime with clavulanic acid and cefotaxime with clavulanic acid) for ESBL confirmatory testing. Future studies should also characterize transmission pathways by assessing antibiotic resistance in commercial food animals and environmental reservoirs. In this study, we observed an increase in enteric colonization of antibiotic-resistant bacteria among children with exposures to domestic animals and their waste in the household environment and children living in areas with a higher density of commercial food animal production operations.

Imipenem-metal complexes: Computational analysis and toxicity studies with wastewater model microorganisms

The occurrence of antibiotic residues in diverse water sources has long been acknowledged as a potential health concern due to the emergence and spread of antibiotic-resistant bacteria and genes. However, there have been limited studies into the presence of antibiotic-metal complexes (AMCs) in real-time wastewater matrices, and their impact on wastewater microbial communities. The present work, in this regard, investigated the stability of Imipenem-metal complexes (Me = Mg (II), Ca (II), Fe (II), Cu (II), and Al (III)) with computational studies, stoichiometry with potentiometric measurements, and their antibacterial activity towards wastewater model microorganisms- Bacillus subtilis (B. subtilis) and Escherichia coli (E. Coli) by Colony Forming Unit (CFU) method. The lower energy of Imipenem-metal complexes than the parent antibiotic- Imipenem, during energy optimization using density functional (DFT) methods, revealed that metal interactions of Imipenem stabilize the drug by minimizing its energy. Further, CFU studies indicated that these complexes display higher antimicrobial activity than parent antibiotics. The electron delocalization over the entire chelated system (AMCs) reduces polarity and increases the lipophilicity of the complexes, thereby facilitating stronger interaction between AMCs and the bacterial cell membrane. Results indicate increased antibacterial activity of Imipenem-metal complexes for both E. coli and B. subtilis. The antibacterial activity, was however, more pronounced in B. subtilis, with >97% growth inhibition for metal complexes of Imipenem (at a Minimum Inhibitory Concentration of 20 nM or 6 ppb (i.e., MIC90)), for both the stoichiometric ratios (metal to ligand) ratios (M: L 1: 1 and 2: 1). All around, with increased stability and toxicity, AMCs are emerging as contaminants of concern and demand immediate attention to devise methods for their removal.

Leading reasons for antibiotic prescriptions in pediatric respiratory infections: influence of fever in a primary care setting

BackgroundAntibiotic overuse in children is a significant public health concern, as it can lead to the emergence and spread of antibiotic-resistant bacteria. Although respiratory infections account for most antibiotic prescriptions in children, many of these infections are viral and do not require antibiotics. In this study, we aimed to investigate the use of antibiotics in children with respiratory infections in a primary care setting and to explore the possible role of fever on antibiotic prescription.MethodsWe conducted a prospective observational study that evaluated preschool children aged 0–5 years who were assessed by their primary care pediatricians for respiratory infectious diseases between October 2019 and March 2021. The study involved 69 public primary care pediatricians and a total of 678 pediatric episodes for respiratory infections.ResultsAmoxicillin/clavulanate was the most frequently prescribed drug. Bronchitis accounted for most of inappropriate antibiotic prescriptions (73%). Furthermore, the presence of fever was associated with a ~ 300% increase in the likelihood of prescribing antibiotics for respiratory infections that do not typically require antibiotics.ConclusionOur findings emphasize the need for adherence to international guidelines and recommendations in the primary care of children to reduce unnecessary antibiotic use and prevent the development of antibiotic resistance. This study also underscores the potential relevance of new studies to evaluate antibiotic prescription attitudes in other clinical settings and geographical areas.

First report of contamination of dried spices and herbs with desiccation-tolerant, biofilm-forming A. baumannii

The spread of antibiotic-resistant bacteria through the food chain is an issue of growing concern for public health. Antibiotic-resistant strains of Acinetobacter baumannii are commonly identified in nosocomial infections and have been linked to the highest mortality rates. However, A. baumannii has been detected in various food products, and the extent to which the food chain serves as a reservoir for this pathogen remains largely unclear. The current study aimed at investigating the prevalence of A. baumannii in dried spices, herbs, nuts and dried fruits. The ability of 20 recovered A. baumannii isolates to resist antibiotics, form biofilms and tolerate desiccation was tested. Additionally, multi-locus sequence typing (MLST) was used to genotype the isolates. The antibiotic susceptibility testing revealed that most of the isolates were susceptible, and displayed strong ability to form biofilms. MLST revealed 11 new sequence types (STs), while 9 isolates belonged to 7 known STs. Interestingly, 5 isolates (25%) were able to survive the desiccation conditions up to 56 days. This is the first study to demonstrate that spices and herbs are potential reservoirs for A. baumannii, which underlines the importance of continuous epidemiological surveillance in spices and dried herbs to reduce the risk of A. baumannii spread. Moreover, our findings highlights the need for quality control measures in the processing of dried spices and herbs.

Light-Based Anti-Biofilm and Antibacterial Strategies.

Biofilm formation and antimicrobial resistance pose significant challenges not only in clinical settings (i.e., implant-associated infections, endocarditis, and urinary tract infections) but also in industrial settings and in the environment, where the spreading of antibiotic-resistant bacteria is on the rise. Indeed, developing effective strategies to prevent biofilm formation and treat infections will be one of the major global challenges in the next few years. As traditional pharmacological treatments are becoming inadequate to curb this problem, a constant commitment to the exploration of novel therapeutic strategies is necessary. Light-triggered therapies have emerged as promising alternatives to traditional approaches due to their non-invasive nature, precise spatial and temporal control, and potential multifunctional properties. Here, we provide a comprehensive overview of the different biofilm formation stages and the molecular mechanism of biofilm disruption, with a major focus on the quorum sensing machinery. Moreover, we highlight the principal guidelines for the development of light-responsive materials and photosensitive compounds. The synergistic effects of combining light-triggered therapies with conventional treatments are also discussed. Through elegant molecular and material design solutions, remarkable results have been achieved in the fight against biofilm formation and antibacterial resistance. However, further research and development in this field are essential to optimize therapeutic strategies and translate them into clinical and industrial applications, ultimately addressing the global challenges posed by biofilm and antimicrobial resistance.

Key parameters for enhancing visible-light-driven photocatalytic activity of ZnS nanoparticle

The use of pharmaceuticals is increasing rapidly as the industrialization of the pharmaceutical industry progresses. Accordingly, antibiotics discharged into wastewater are attracting attention as emerging pollutants that aggravate water pollution. The spread of antibiotic-resistant bacteria that cause clinically infectious diseases is also a global challenge. In this study, ZnS nanoparticles were synthesized using a simple hydrothermal process and applied to the photocatalytic degradation of antibiotic tetracycline and the photocatalytic inactivation of high-strength multidrug-resistant bacteria (Klebsiella pneumonia and Staphylococcus aureus) and total coliforms under visible light irradiation. The prepared nanomaterial was characterized using a range of analytical techniques to confirm the properties of the ZnS nanoparticles. The photocatalytic activities of nanoparticles were investigated with various parameters, such as catalyst dose, type and intensity of light, antibiotic concentration, and pH. Among them, the type of light (white light) and pH were the most important factors affecting the photocatalytic activity of ZnS nanoparticles. The basic pH condition (pH 10) improved the photocatalytic reaction activity (k = 0.0318 min−1, R2 = 0.9653), approximately 30 times more than acidic conditions (pH 3) and approximately 3.3 times more than neutral conditions (pH 7). The total coliforms in wastewater effluent were completely inactivated within 30 min of reaction time using white light irradiation (80 mW/cm2). The scavenger experiment revealed that the reactive oxygen species appeared in the order of O2·− > ·OH > h+. The reusability studies showed that the ZnS nanoparticles were very stable and retained more than 94% of their catalytic capacity after five cycles.

Uncovering the effects of copper feed supplementation on the selection of copper-tolerant and antibiotic-resistant Enterococcus in poultry production for sustainable environmental practices

The use of antibiotics in animal production is linked to the emergence and spread of antibiotic-resistant bacteria, a threat to animal, environmental and human health. Copper (Cu) is an essential element in poultry diets and an alternative to antibiotics, supplementing inorganic or organic trace mineral feeds (ITMF/OTMF). However, its contribution to select multidrug-resistant (MDR) and Cu tolerant Enterococcus, a bacteria with a human-animal-environment-food interface, remains uncertain. We evaluated whether feeding chickens with Cu-ITMF or Cu-OTMF contributes to the selection of Cu tolerant and MDR Enterococcus from rearing to slaughter. Animal faeces [2–3-days-old (n = 18); pre-slaughter (n = 16)] and their meat (n = 18), drinking-water (n = 14) and feed (n = 18) from seven intensive farms with ITMF and OTMF flocks (10.000–64.000 animals each; 2019–2020; Portugal) were sampled. Enterococcus were studied by cultural, molecular and whole-genome sequencing methods and Cu concentrations by ICP-MS. Enterococcus (n = 477; 60 % MDR) were identified in 80 % of the samples, with >50 % carrying isolates resistant to tetracycline, quinupristin-dalfopristin, erythromycin, streptomycin, ampicillin or ciprofloxacin. Enterococcus with Cu tolerance genes, especially tcrB ± cueO, were mainly found in faeces (85 %; E. faecium/E. lactis) of ITMF/OTMF flocks. Similar occurrence and load of tcrB ± cueO Enterococcus in the faeces was detected throughout the chickens' lifespan in the ITMF/OTMF flocks, decreasing in meat. Most of the polyclonal MDR Enterococcus population carrying tcrB ± cueO or only cueO (67 %) showed a wild-type phenotype (MICCuSO4 ≤ 12 mM) linked to absence of tcrYAZB or truncated variants, also detected in 85 % of Enterococcus public genomes from poultry. Finally, < 65 μg/g Cu was found in all faecal and meat samples. In conclusion, Cu present in ITMF/OTMF is not selecting Cu tolerant and MDR Enterococcus during chickens' lifespan. However, more studies are needed to assess the minimum concentration of Cu required for MDR bacterial selection and horizontal transfer of antibiotic resistance genes, which would support sustainable practices mitigating antibiotic resistance spread in animal production and the environment beyond.