Antibiotic Levels Research Articles

Antibiotic Residues in Milk and Milk-Based Products Served in Kuwait Hospitals: Multi-Hazard Risk Assessment

Antimicrobial resistance (AMR) poses a significant global health challenge affecting food safety and development. Residues of antibiotics in food from animal sources, particularly milk, contribute to the development and spread of AMR, alter intestinal microbiota, and potentially lead to allergies, serious health conditions, and environmental and technological problems within the dairy industry. Therefore, this study investigated the residue levels of veterinary drugs from β-lactam antibiotics and tetracyclines in milk and milk products and assessed human health risks. Two hundred milk and milk product samples (pasteurized milk, sterile milk, soft white cheese, and processed cheese, 50 each) were collected from different hospitals in the State of Kuwait and screened for antibiotic residues using a microbial inhibition assay (Delvotest SP-NT) and high-performance liquid chromatography (HPLC). Delvotest SP-NT and HPLC analyses showed that 30, 28, 26, and 24% of the pasteurized milk, sterilized milk, white soft cheese, and processed cheese samples tested positive for antibiotic residues. Forty-eight milk and cheese samples were confirmed as positive by both methods, and six samples initially found to be negative by Delvotest SP-NT were confirmed as positive by HPLC. Multi-antibiotic residues were detected in five samples by using HPLC. The kappa coefficient (0.921; p < 0.0001) revealed complete concordance between the HPLC and Delvotest SP-NT results. Ampicillin was the most abundant residue in the positive samples (31.48%), ranging from 2.44 to 3.89 μg/L, with an overall mean concentration of 3.492 ± 0.094 μg/L, followed by tetracycline and oxytetracycline (27.78% each), ranging from 54.13 to 220.3 μg/L and from 41.55 to 160.7 μg/L, with mean concentrations of 129.477 ± 14.22 and 91.86 ± 9.92 μg/L, respectively. The amoxicillin levels in the samples (12/54; 22.22%) ranged from 3.11 to 5.5 μg/L, with an overall mean concentration of 3.685 ± 0.186 μg/L. The maximum concentrations of ampicillin, amoxicillin, and tetracycline were detected in processed cheese with mean concentrations of 3.89 ± 0.28 µg/L, 3.95 ± 0.15 µg/L, and 170.3 ± 0.27 µg/L, respectively. Pasteurized milk contained the maximum concentrations of oxytetracycline, with a mean concentration of 120.45 ± 0.25 µg/L. The tetracycline residues exceeded the standard maximum residue limits (MRLs; 100 µg/L) in 6% of both pasteurized and sterilized milk samples, and in 4% of processed cheese. Additionally, the oxytetracycline levels in pasteurized milk (6%) and amoxicillin levels in processed cheese (2%) were higher than the permitted MRLs (100 µg/L and 4 µg/L, respectively). Furthermore, the antibiotic residues detected in 12.5% (25/200) of the samples were close to standard permissible MRL limits for ampicillin (5%), amoxicillin and oxytetracycline (3% each), and tetracycline (1.5%). Hazard quotients, which compare the standard acceptable daily intake (ADI) to the estimated daily exposure (EDI), indicated that the overall risk associated with antibiotic residues in these dairy products is low. The EDI was lower than the ADI for the tested antibiotics, indicating an elevated safety margin. While the overall hazard quotients are low, the potential for the development of antibiotic resistance due to long-term exposure to low levels of antibiotics should be considered. Hence, strict regulations and enforcement are necessary to prevent excessive residue levels and to promote responsible antibiotic use in dairy production. Regular monitoring of antibiotic residues in dairy products is essential for ensuring consumer safety.

Identification and genetic dissection of convergent persister cell states.

Persister cells, rare phenotypic variants that survive normally lethal levels of antibiotics, present a major barrier to clearing bacterial infections1. However, understanding the precise physiological state and genetic basis of persister formation has been a longstanding challenge. Here we generated a high-resolution single-cell2 RNA atlas of Escherichia coli growth transitions, which revealed that persisters from diverse genetic and physiological models converge to transcriptional states that are distinct from standard growth phases and instead exhibit a dominant signature of translational deficiency. We then used ultra-dense CRISPR interference3 to determine how every E. coli gene contributes to persister formation across genetic models. Among critical genes with large effects, we found lon, which encodes a highly conserved protease4, and yqgE, a poorly characterized gene whose product strongly modulates the duration of post-starvation dormancy and persistence. Our work reveals key physiologic and genetic factors that underlie starvation-triggered persistence, a critical step towards targeting persisters in recalcitrant bacterial infections.

Nanoemulsion and nanoemulgel-based carriers as advanced delivery tools for the treatment of oral diseases.

Oral diseases rank among the most widespread ailments worldwide posing significant global health and economic challenges affecting around 3.5billion people, impacting the quality of life for affected individuals. Dental caries, periodontal disease, bacterial and fungal infections, tooth loss and oral malignancies are among the most prevalent global clinical disorders contributing to oral health burden. Traditional treatments for oral diseases often face challenges such as poor drug bioavailability, breakdown of medication in saliva, inconsistent antibiotic levels at the site of periodontal infection as well as higher side effects. However, the emergence of nanoemulgel (NEG) as an innovative drug delivery system offers promising solutions where NEG combines the advantages of both nanoemulsions (NEs) and hydrogels providing improved drug solubility, stability, and targeted delivery. Due to their minuscule size and ability to control drug release, NEGs hold promise for improving treatment of oral diseases, where versatility of these delivery systems makes them suitable for various applications, including topical delivery in dentistry. This review concisely outlines the anatomy of the oral environment and investigates the therapeutic potential of NE-based gels in oral disorder treatment. It thoroughly examines the challenges of drug delivery in the oral cavity and proposes strategies to improve therapeutic efficacy, drawing attention to previous research reports for comparison. Through comprehensive analysis, the review highlights the promising role of NEGs as a novel therapeutic approach for oral health management via research advancements and their clinical translation. Additionally, it provides valuable insights into future research directions and development opportunities in this area.

Impacts of micro/nano plastics on the ecotoxicological effects of antibiotics in agricultural soil: A comprehensive study based on meta-analysis and machine learning prediction

Micro/nano plastics (M/NPs) and antibiotics, as widely coexisting pollutants in environment, pose serious threats to soil ecosystem. The purpose of this study was to systematically evaluate the ecological effects of the co-exposure of M/NPs and antibiotics on soil organisms through the meta-analysis and machine learning prediction. Totally, 1002 data set from 38 articles were studied. The co-exposure of M/NPs significantly promoted the abundance (62.68 %) and migration level (55.22 %) of antibiotic contamination in soil, and caused serious biotoxicity to plants (−12.31 %), animals (−12.03 %), and microorganisms (35.07 %). Using 10 variables, such as risk response categories, basic physicochemical properties, exposure objects, and exposure time of M/NPs, as data sources, Random Forests (RF) and eXtreme Gradient Boosting (XGBoost) models were developed to predict the impacts of M/NPs on the ecotoxicological effects of antibiotics in agricultural soil. The effective R2 values (0.58 and 0.60, respectively) indicated that both models can be used to predict the future ecological risk of M/NPs and antibiotics coexistence in soil. Particle size (13.54 %), concentration (5.02 %), and type (11.18 %) of M/NPs were the key characteristic parameters that affected the prediction results. The findings of this study indicate that the co-exposure of M/NPs and antibiotics in soil not only exacerbates antibiotic contamination levels but also causes severe toxic effects to soil organism. Furthermore, this study provides an effective approach for ecological risk assessment of the coexistence of M/NPs and antibiotics in environment.

Trace antibiotic exposure affects murine gut microbiota and metabolism

Gut microbiota is important for host metabolism regulation. Antibiotic exposure disturbs this regulation by affecting the microbiome. Trace levels of antibiotics in water have been widely reported and the impact on gut microbiota remains understudied. We provide evidence of trace antibiotic exposure affecting the host's gut microbiota using a mouse model exposed to trace amounts of azithromycin (AZI) or ciprofloxacin (CIP) in drinking water. AZI exposure in males changed the distribution of gram-positive (Firmicutes and Bacteroidetes) and gram-negative (Proteobacteria, Fusobacteria, and Verrucomicrobia) bacteria at an early age. Both AZI and CIP resulted in abnormal microbiota maturation. Additionally, the production of short-chain fatty acids (SCFAs), including acetate, butyrate, and propionate, in females is affected. Serum hormone and metabolome levels shifted after trace antibiotic exposure. AZI and CIP exposure broadly disrupted original host-microbe interaction relationships between the gut microbiota and SCFAs or serum metabolites. In this study, we demonstrated that trace antibiotic exposure was associated with extensive gut microbiota and metabolism perturbation in mice and that the potential health risks in susceptible populations should be considered.

Unveiling the impact of antibiotic stress on biofilm formation and expression of toxin-antitoxin system genes in Clostridium difficile clinical isolates.

The study investigates how antibiotics affect biofilm formation and toxin gene expression in Clostridium difficile, which is essential for its survival and persistence. The study confirmed 25 strains of C. difficile and assessed biofilm formation. The MIC of metronidazole and vancomycin was determined through agar dilution, and the impact of sub-MIC levels on biofilm formation and eradication was investigated. Additionally, Real-time PCR was used to analyze the expression levels of target genes related to antibiotic treatment. We found that certain genes, such as the ImmA/IrrE system, were associated with increased biofilm formation in isolates. Sub-MIC antibiotic levels influenced gene expression related to biofilm activities, particularly emphasizing the importance of toxin-antitoxin systems. The results suggest that antibiotics at sub-MIC levels may play a signaling role in promoting biofilm formation and gene expression in C. difficile. Our study suggests that toxin and antitoxin genes may impact C. difficile biofilm formation, while antibiotics could signal biofilm strengthening and gene expression increase.

Antibiotics and Pesticides Enhancing the Transfer of Resistomes among Soil-Bayberry-Fruit Fly Food Chain in the Orchard Ecosystem.

While substantial amounts of antibiotics and pesticides are applied to maintain orchard yields, their influence on the dissemination and risk of antibiotic resisitome in the orchard food chain remains poorly understood. In this study, we characterized the bacterial and fungal communities and differentiated both antibiotic resistance genes (ARGs) and virulence factor genes (VFGs) in the soil, Chinese bayberry (matured and fallen), and fruit fly gut, collected from five geographic locations. Our results showed that fruit fly guts and soils exhibit a higher abundance of ARGs and VFGs compared with bayberry fruits. We identified 112 shared ARGs and 75 shared VFGs, with aminoglycoside and adherence factor genes being among the most abundant. The co-occurrence network revealed some shared microbes, such as Bacillus and Candida, as potential hosts of ARGs, highlighting the vector risks for both above- and below-ground parts of the orchard food chain. Notably, the elevated levels of antibiotics and pesticide residues in orchard soils increase ARGs, mobile genetic elements (MGEs), and VFGs in the soil-bayberry-fruit fly food chain. Our study highlighted that agricultural management, including the overuse of antibiotics and pesticides, could be the key factor in accumulating resistomes in the orchard food chain.

Multiple mechanisms enable broad-spectrum activity of the Pelargonium sidoides root extract EPs 7630 against acute respiratory tract infections.

There is clinical evidence showing that the Pelargonium sidoides root extract EPs 7630 is a safe and effective treatment for a range of acute infectious respiratory illnesses. Moreover, EPs 7630 has been shown to reduce the use of antibiotics, which is important in the context of rising antibiotic resistance levels. A wide range of mechanisms appears to contribute to the beneficial effects of EPs 7630, e.g. antibacterial, antiviral, immunomodulatory, and epithelial barrier effects. This broad spectrum of pharmacological activities seems to enable the clinical activity of EPs 7630 against multiple respiratory infections. In particular, the combination of antiviral and immunomodulatory effects may enable EPs 7630 to tackle acute viral respiratory infections both in early stages of the disease process, which are driven by virus replication, as well as in later stages, which are caused by an overshooting immune response. Hence, EPs 7630 is a prime example of a plant extract with evidence-based clinical efficacy, including a solid understanding of the underlying mechanisms of action. The example of EPs 7630 demonstrates that plant extracts have a potential role as evidence-based clinical treatments and that they deserve pre-clinical and clinical testing and investigation in the same way as any other drug class.

Multidrug-resistant bacteria in healthcare-associated infections among pediatric patients in Lima, Peru: a call for antibiotic stewardship programs

Abstract Background Healthcare-associated infections (HAIs) in children contribute to elevated morbidity and mortality rates. While the surveillance of antibiotic-resistant bacteria involved in HAIs is important, there is limited data available in Latin America. The present study aimed to evaluate the antibiotic resistance levels in bacteria isolated from hospitalized patients with HAIs in a pediatric referral center in Lima – Peru. Methods Surveillance data of HAIs from November 2021 to June 2023 among pediatric patients at Instituto Nacional de Salud del Niño San Borja was prospectively collected and reviewed. The dataset included comprehensive information on the clinical and epidemiological characteristics of patients, bacteria isolation sites and identification, as well as resistance profiles to 13 antibiotics. HAIs included were central line-associated bloodstream infections (CLABSI), catheter-associated urinary tract infections (CAUTI) and ventilator-associated pneumonia (VAP). Results We included 143 bacterial isolates from pediatric patients hospitalized with HAIs, of which 53.85% were male (n=77). The median age of the patients was 7 months (IQR: 2 -36). A total of 44.76% (n=64) had congenital diseases and 20.28% (n=29) had cancer. Most of the isolates were collected from pediatric Intensive Care Unit (n=104, 72.73%). The median time from the hospital admission to the appearance of HAIs was 17 days (IQR: 7-28). The most frequent isolates were Gram negative bacteria: Klebsiella pneumoniae (n=33), Pseudomonas aeruginosa (n=34) and Escherichia coli (n=24). Among Gram positive bacteria, Staphylococcus epidermidis (n=5) and Staphylococcus aureus (n=5) were the most frequent species. Regarding the site of isolation, the primary etiological agent in CLABSI was K. pneumoniae (n=18); in CAUTI, E. coli (n=13) and in VAP P. aeruginosa (n=9). Multidrug-resistant (MDR) isolates were identified, mainly among K. pneumoniae (62.50%), E. coli (54.55%), and P. aeruginosa (26.74%). Difficult-to-treat resistance was only present in 2.94% of P. aeruginosa isolates. Overall resistance to piperacillin-tazobactam was below 16%. Resistance to cephalosporins was higher than 40% for K. pneumoniae and E. coli isolates, with frequencies exceeding 60% for cefuroxime, ceftazidime, ceftriaxone, cefepime and cefoperazone/sulbactam. E. coli and K. pneumoniae resistance to carbapenems was below than 10%; however, P. aeruginosa resistant isolates were identified in 38.24% and 39.39% for meropenem and imipenem, respectively. Ciprofloxacin resistance was frequent among E. coli (70%) and K. pneumoniae (60.87%), whereas only 26.67% of P. aeruginosa. Amikacin resistance was detected in K. pneumoniae and P. aeruginosa only, with a frequency of 23.08% and 20%, respectively. Conclusion Alarming levels of antibiotic-resistant bacteria were found in HAIs among pediatric patients. Our results highlight the need of supporting initiatives for HAIs control, developing institutional guidelines for prevention and strengthening antibiotic stewardship in pediatric patients. Table 1: Antibiotic resistance profiles of the main microorganisms of healthcare-associated infections (November 2021 – June 2023)

Dispersive solid phase extraction of chloramphenicol and florfenicol in honey sample performed in narrow bore tube with the aid of magnetic ionic liquids prior to HPLC-DAD analysis

The precedence of high levels of antibiotics in animal-derived foods such as honey poses a significant food safety risk. Therefore, the development of an accurate, and reliable method for determining these residues is crucial. In this study, a new extraction method was proposed for the simultaneous determination of chloramphenicol and florfenicol residues in honey samples prior to high performance liquid chromatography analysis. The method involved using amino-functionalized UiO-66 metal–organic framework (NH2-UiO-66) as a sorbent in a narrow bore tube. To begin, the solution was placed into a narrow bore tube and the pH was adjusted to 6. Then, 100 mg of the sorbent was added to the solution. The particles were slowly passed through the solution and collected in the tube bottom. After removing the supernatant phase, 55 µL of 1-butyl-3-methylimidazolium tetrachloroferrate (III) magnetic ionic liquid was used as the elution solvent under sonication for 3 min. The optimized method exhibited low limits of detection (0.19 and 0.44 ng g−1) and quantification (0.63 and 1.4 ng g−1), good extraction recovery (81 and 74 %), and good linearity of the calibration curve (r2 ≥ 0.996) over the ranges of 1.2–500 and 2.4–500 ng g−1 for florfenicol and chloramphenicol, respectively. Precision was satisfactory, with relative standard deviations ≤8.1 % for both intra- and inter-day precisions. The developed method was done on ten honey samples and chloramphenicol was found in five samples.

Cost-Effective Synthesis of MXene Cadmium Sulfide (CdS) for Heavy Metal Removal.

Background Environmental contamination resulting from the release of untreated industrial wastewater has emerged as a critical worldwide issue. These effluents frequently have high levels of heavy metals and antibiotics, which are bad for aquatic ecosystems and human health. Oftentimes, conventional wastewater treatment techniques fall short of effectively eliminating these pollutants. Innovative materials that may efficiently absorb or break down contaminants from contaminated water sources are, therefore, desperately needed. Hydrothermally produced MXene cadmium sulfide (CdS) composites have shown great promise as an adsorbent material because of their special qualities, which include high surface area, chemical stability, and customizable surface functions that improve their adsorption capacity for heavy metals and antibiotics alike. Aim The aim of this study is to produce MXene-CdS nanoparticles in a cost-effective method for the simultaneous removal of heavy metals from aqueous contaminants for water pollution control. Methods and materials MXenes were synthesized by selectively etching Ti3AlC2 MAX-phase ceramics using aqueous HF. CdS nanoparticles were synthesized separately and integrated with MXenes via a hydrothermal process. The resulting MXene CdS nanocomposites were characterized using scanning electron microscopy (SEM) for morphology, energy dispersion spectrum (EDS) for elemental composition, X-ray diffraction(XRD) study for phase identification, and removal of heavy metals viaMXene CdS. Results Consistent distribution of CdS nanoparticles on the MXene surface and the creation of MXene CdS nanomembranes with a well-defined shape were observed by SEM analysis. Ti, C, Cd, and S elements, indiciaries of a successful composite formation, were confirmed to be present by EDS. The crystalline structure of both the MXene and CdS phases was confirmed by the distinctive peaks seen in the XRD patterns. MXene-CdS composites facilitate the effective removal of chromium ions from contaminated water. The excellent hydrophilicity of the produced nanomembrane allowed for effective interaction with watery contaminants. Conclusion This study showcases the successful synthesis and characterization of MXene-CdS nanocomposites for environmental remediation, particularly in removing toxic metals like chromium from industrial effluents. SEM analysis confirmed the uniform distribution of CdS nanoparticles on the MXene surface, while elemental composition validated their integration. XRD analysis confirmed the crystalline structures of both components. The nanocomposite exhibited excellent hydrophilicity, enhancing the efficient adsorption of heavy metals. Its large surface area and chemical stability contribute to high adsorption efficiency, making it ideal for wastewater treatment. The scalable synthesis process supports practical applications. This research highlights MXene-CdS nanocomposites as a cost-effective, sustainable solution for water pollution control.

Microextraction by packed sorbent: Introducing a novel hybrid silica-based chitosan-graphene oxide biosorbent for the evaluation of pesticides and antibiotics in food matrices

This study introduces a novel silica-graphene oxide@chitosan (SiGO@CS) material as a packed biosorbent for microextraction by packed sorbent (MEPS), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) analysis of pesticides (atrazine and thiamethoxam) and antibiotics (ceftiofur and sulfonamide) in food samples. The graphene-based aerogel was modified with varying percentages of silica-graphene oxide/chitosan (w/w) and characterized to confirm successful chitosan incorporation. Optimization of the MEPS protocol, using 24–1 and 23 experimental designs, identified draw/eject and washing cycles as the most influential parameters for extraction efficiency. The SiGO@CS biosorbent with 80 % CS/SiGO (w/w) exhibited superior extraction efficiency compared to other ratios and commercial sorbents. The method demonstrated excellent linearity for all analytes (R² > 0.9900), with low limits of detection (LOD) and quantification (LOQ) ranging from 0.020 to 0.045 µg l-1 and 0.045 to 1.0 µg l-1 for pesticides, respectively, and 5 to 15 µg l-1 and 15 to 20 µg l-1 for antibiotics, respectively. Trueness values were within 82 % to 109 %. The method's green credentials were confirmed using AGREEprep and the Green Analytical Procedure Index (GAPI) approach, highlighting sorbent reusability (over 15 times) and rapid analytical throughput (5 min per sample) with low use of pre-treated sample extract volume (500 µL). The application to local corn, tomato, and milk samples confirmed the detection and quantification of thiamethoxam and atrazine at concentrations above the recommended ingestion per day for one sample of tomato and corn out of the three samples analyzed. Furthermore, using the novel SiGO@CS biosorbent in the MEPS protocol offers a green, high-performance analytical alternative to traditional sorbent phases, with the potential for evaluating trace levels of pesticides and antibiotics in food matrices.

Intraosseous regional antibiotic prophylaxis in total joint arthroplasty (TJA): Systematic review and meta-analysis

BackgroundA major catastrophic adverse event after total joint arthroplasty surgery (TJA) is the periprosthetic joint infection (PJI). In the recent years, regional antibiotic prophylaxis has gained momentum as a novel infection control strategy in total knee arthroplasty (TKA), with different purported benefits over systemic administration. The current article was planned to comprehensively review the available evidence in literature; as well as compare the safety and effectiveness of intraosseous (IO) antibiotic prophylaxis with systemic prophylaxis in patients undergoing TJA. MethodsAn independent database (5 databases: Pubmed, Scopus, Embase, Web of science and Cochrane library) search was performed (on January 1, 2024) using suitable key words [PROSPERO (registration number: CRD42023458219)]. All randomised controlled trials (RCT), prospective or retrospective studies reporting data on intraosseous vancomycin or other antibiotics during arthroplasty for prophylaxis of PJI were considered. Studies not pertaining to the topic of interest or non-clinical trials were excluded. The evaluated outcome parameters included PJI incidence, systemic antibiotic levels, minimal inhibitory concentrations, local antibiotic concentrations achieved in soft tissues (or fat) and bone; and associated complications. While the “risk of bias” was evaluated using ROB-2 tool and MINORS criteria; LibreOffice version (v)7.5.6 was utilized for data management. OpenMeta-analyst v5.26.14 and RevMan v5.4 software were employed for meta-analysis. ResultsFollowing our literature search, 11 studies (1 prospective series, 6 RCT and 4 retrospective studies) were finally identified. Based on our meta-analysis, there was statistically higher antibiotic concentration in the bone [meandifference(MD):25.12 μg/g;95%CI:10.32,39.91;z=3.33,p = 0.0009] and local fat tissues [MD:22.01 μg/g;95%CI:1.71,32.30;z=4.19,p < 0.0001) following IO prophylaxis, as compared with the systemic drug administration. IO prophylaxis was also associated with a significant reduction in prosthetic joint infections (PJI; April 1633 and 25/2213 patients developed PJI in IO and systemic prophylaxis groups, respectively; p = 0.006). There was significant difference in gram-positive infections between IO and systemic prophylaxis groups (2/1123 and 13/1753 g + ve infections in IO and systemic prophylaxis groups, respectively; p = 0.05). Our review and meta-analysis revealed no substantial difference in complications amongst the groups (p = 0.66). ConclusionIO antibiotic prophylaxis appears to be an effective and safe strategy in patients undergoing TJA. IO access provides substantially enhanced antibiotic elution into the local tissues (bone and soft tissues); and consequently, results in reduced of PJI rates after TJA (in comparison with conventional systemic antibiotic prophylaxis).

Assessing the Impact of the Introduction Of Advance Care Planning In Nursing Home Residents Admitted to Hospital

Abstract Background Nursing home residents may present inappropriately to the Emergency Department at the end of life (EOL). Appropriate advance care planning (ACP) may reduce these presentations. Inpatient teams are in a position to discuss, document and support these ACPs for nursing home residents admitted under their care. Methods Building on existing inpatient and outreach specialist pathways in a model three hospital, formal ACPs were introduced for all inpatients from Jan 2024 admitted from a nursing home where it was deemed clinically appropriate. The completed advance care plan included decisions re cardiopulmonary resuscitation, level of intervention (including hospital transfer), antibiotics, fluids, nutrition plan and medications to support EOL care. ACP discussions took place with the consultant geriatrician, patient, nominated family/patient support and director of nursing. Data on discharged patients (including presence of ACP on discharge) was collected and analysed for emergency re-presentations. Results Of 137 patients discharged back to their nursing homes in the first 4 months of 2024, 41 (30%) had an ACP in place while 96 (70%) did not. Of those with ACP in place, 6/41 re-presented to Emergency Department within this timeframe vs 17/96 who were discharged without an ACP (15% vs 18%, p=0.66). However, only 3/41 with ACP were re-admitted to hospital from the emergency department vs 15/96 without an ACP (7% vs 16%, p=0.19). No patients discharged with an ACP re-presented and subsequently died in hospital, while 1/96 (1%) of those discharged without an ACP died in hospital after re-presentation. Conclusion ACP discussion did not reduce re-presentations to hospital but there was a non-significant trend towards a reduction in re-admissions. Overall, there was an extremely low rate (1/137, 0.7%) of patients re-presenting to hospital and dying during that admission. Further work is ongoing to examine the criteria that would prompt ACP discussion in nursing home residents admitted to hospital.

Occurrence, distribution, and ecological risks of antibiotics and antibiotic resistance genes in the surface waters of Gaoyou Lake, China.

This work examined the occurrence characteristics and ecological risks of 31 antibiotics across five classes and seven ARGs in the surface waters of Gaoyou Lake. A total of 27 antibiotics, spanning four classes, were detected in the surface waters of Gaoyou Lake, with an overall concentration ranging from 57.5 to 114ng/L and an average of 78.8ng/L. Sulfonamide antibiotics exhibited the highest average concentration at 32.7ng/L. Spatial analysis revealed that antibiotic concentration levels in the western region of the lake were higher than those in other areas. Similarly, ARGs were most abundant in this area, with sulfonamide ARGs demonstrating a notably higher mean abundance than other ARGs. Correlation analysis revealed strong positive associations between sul1 and several antibiotics, including sulfadimidine, sulfamethoxazole, ciprofloxacin, lincomycin, clindamycin, erythromycin, and intl1 (P < 0.05), with intra-group correlations among sulfonamide ARGs exceeding those between different ARG groups. Ecological risk assessment indicated that erythromycin and sulfamethoxazole presented medium risks, whereas roxithromycin, azithromycin, and lincomycin were associated with low risks to aquatic organisms. The ecological risk proportions across monitoring sites were primarily low (10.6%) and moderate (16.7%), with no high-risk areas identified and 72.7% presenting no risk. The cumulative ecological risk quotient (RQcum) suggested a medium-risk level at all surveyed sites.

464 Awardee Talk: Gastrointestinal tract physiology in young pigs

Abstract It is indeed a great privilege to have been awarded the 2024 American Feed Industry Association Award in Nonruminant Nutrition Research. I am honored to follow in the footsteps of many great non-ruminant nutritionists in the industry. I commenced my career in the pork industry with a PhD in digestive nutritional physiology focusing on the newly weaned piglet that, some 35 yr later, is still the subject of significant interest amongst researchers, veterinarians and practitioners, and producers alike. My research was amongst the first to demonstrate direct relationships between voluntary feed intake after weaning and structure and function of the small intestine, corresponding to production consequences. To circumvent intestinal tract disturbances after weaning, antibiotic growth promotors (AGPs)/prophylactic levels of antibiotics and mineral compounds (e.g., ZnO) were routinely included in diets. With the withdrawal of AGPs and in some jurisdictions, in-feed medications and ZnO, the commercial importance of maximizing feed intake in the post-weaning period, with appropriate inclusion of fiber and selected feed additives, has become even more apparent. Some of the more recent work I have been involved in, still involving the gastrointestinal tract, has explored the interrelationships as to why progeny born to first-litter sows perform worse than progeny born to multiparous sows. This is a global issue for the pork industry, especially in view of increasing litter size, yet remains one that has been relatively underexplored. A series of Australian studies using primiparous and multiparous sows, and their progeny conducted on commercial farms confirmed these findings, and reported some significant physiological, immunological, and anatomical differences between piglets born to different parity mothers. Piglets born to first-litter sows are born and weaned lighter than their counterparts born to older sows, suggesting they suffer poorer acquisition of maternal immunity and delays in intestinal tract development and skeletal muscle both in utero and soon after birth, and around weaning. Piglets born to first-litter sows enter weaning with reduced intestinal tract integrity and show some signs of reduced immunocompetence, which taken together, may impede their ability to cope with the stressors of weaning. Weaned piglets are typically treated collectively and are not managed by parity, but lifelong consequences of being born to a first-litter sow suggests further work needs to be done in this field. Gastrointestinal tract structure and function in piglets, and indeed in all neonates, is intricately associated with ‘gut health’, which was a term not even in the lexicon of the pork industry when I began my career. It is pleasing to see that the study of the gastrointestinal tract continues today, stronger than ever, as advances in science and methodologies allow for greater introspection of this organ and its multi-directional influences on the biology of the pig.

Associating prenatal antibiotics exposure with attention deficit hyperactivity disorder symptoms in preschool children: The role of maternal vitamin D

BackgroundThe associations between prenatal antibiotics exposure and attention-deficit/hyperactivity disorder (ADHD) in preschoolers, and the role of maternal vitamin D in these associations, remain to be explored. ObjectivesTo evaluate the relationships between multiple maternal urinary antibiotics levels and preschoolers’ ADHD symptoms, and to identify the potential modifying effects of maternal vitamin D. MethodsBased on a prospective birth cohort, the present study included 2033 motherchild pairs. Maternal urine and serum samples were collected during all three trimesters to measure the urinary concentrations of 43 antibiotics (including two metabolites) and the serum vitamin D levels. The ADHD symptoms of preschoolers were assessed using the Diagnostic and Statistical Manual–oriented ADHD problems scale in the Achenbach Child Behavior Checklist. Multiple informant models in the form of logistic regression were conducted to investigate the associations between prenatal antibiotics exposure and preschooler ADHD symptoms, and these associations were stratified by child sex and maternal vitamin D status. ResultsCompared with the lowest tertile concentrations, maternal exposure to the middle tertile concentrations of doxycycline and human antibiotics/preferred as human antibiotics (HAs/PHAs), and the highest tertile concentrations of doxycycline during the first trimester were associated with an increased risk of ADHD symptoms in children. An increased risk of ADHD symptoms was observed in girls exposed to the highest tertile levels of sulfamethazine during the second trimester. Furthermore, pregnant women with vitamin D deficiency have a greater risk of ADHD symptoms in their offspring after exposure to doxycycline in the first trimester. ConclusionsMaternal exposure to doxycycline and HAs/PHAs during the first trimester increases the risk of ADHD symptoms in preschoolers. Mid-pregnancy sulfamethazine exposure increases the risk of ADHD symptoms in girls. Maternal vitamin D deficiency during pregnancy may exacerbate the adverse effects of doxycycline exposure on ADHD symptoms.

Photocatalysis Inhibits the Emergence of Multidrug-Resistant Bacteria in an Antibiotic-Resistant Bacterial Community in Aquatic Environments.

Bacterial antibiotic resistance has recently attracted increasing amounts of attention. Here, an artificially antibiotic-resistant bacterial community (ARBC) combined with five different constructed antibiotic-resistant bacteria (ARB) with single antibiotic resistance, namely, kanamycin (KAN), tetracycline (TET), cefotaxime (CTX), polymyxin B (PB), or gentamicin (GEM), was studied for the stress response to photocatalysis. With photocatalytic inactivation, the transfer and diffusion of antibiotic resistance genes (ARGs) in the ARBC decreased, and fewer multidrug-resistant bacteria (MDRB) emerged in aquatic environments. After several days of photocatalytic inactivation or Luria broth cultivation, >90% ARB were transformed to antibiotic-susceptible bacteria by discarding ARGs. Bacteria with double antibiotic resistance were the dominant species (99%) of residual ARB. The changes in ARG abundance varied, decreasing for the GEM and TET resistance genes and increasing for the KAN resistance genes. The change in the antibiotic resistance level was consistent with the change in ARG abundance. Correspondingly, point mutations occurred for the KAN, CTX and PB resistance genes after photocatalytic inactivation, which might be the reason why these genes persisted longer in the studied ARBC. In summary, photocatalytic inactivation could reduce the abundance of some ARGs and inhibit the emergence of MDRB as well as block ARG transfer in the bacterial community in aquatic environments. This work highlights the advantages of long-term photocatalytic inactivation for controlling antibiotic resistance and facilitates a better understanding of bacterial communities in real aquatic environments.

Ultrasonically assisted fabrication of electrochemical platform for tinidazole detection

Based on sonochemistry, green synthesis methods play an important role in the development of nanomaterials. In this work, a novel chitosan modified MnMoO4/g-C3N4 (MnMoO4/g-C3N4/CHIT) was developed using ultrasonic cell disruptor (500 W, 30 kHz) for ultra-sensitive electrochemical detection of tinidazole (TNZ) in the environment. The morphology and surface properties of the synthesized MnMoO4/g-C3N4/CHIT electrode were characterized using X-ray diffraction (XRD), fourier transform infrared spectroscopy (FT-IR), scanning electron microscope (SEM) and transmission electron microscope (TEM). Cyclic voltammetry (CV) and differential pulse voltammetry (DPV) techniques were utilized to assess the electrochemical performance of TNZ. The results indicate that the electrochemical detection performance of TNZ is highly efficient, with a detection limit (LOD) of 3.78 nM, sensitivity of 1.320 µA·µM−1·cm−2, and a detection range of 0.1–200 μM. Additionally, the prepared electrode exhibits excellent selectivity, desirable anti-interference capability, and decent stability. MnMoO4/g-C3N4/CHIT can be successfully employed to detect TNZ in both the Songhua River and tap water, achieving good recovery rates within the range of 93.0 % to 106.6 %. Consequently, MnMoO4/g-C3N4/CHIT’s simple synthesis might provide a new electrode for the sensitive, repeatable, and selective measurement of TNZ in real-time applications. Using the MnMoO4/g-C3N4/CHIT electrode can effectively monitor and detect the concentration of TNZ in environmental water, guiding the sewage treatment process and reducing the pollution level of antibiotics in the water environment.

Occurrence, Source Apportionment, and Risk Assessment of Antibiotics in Mangrove Sediments from the Lianzhou Bay, China.

In recent years, the widespread application of antibiotics has raised global concerns, posing a severe threat to ecological health. In this study, the occurrence, source, and ecological risks of 39 antibiotics belonging to 5 classes in mangrove sediments from Lianzhou Bay, China, were assessed. The total concentrations of the antibiotics (∑39 antibiotics) ranged from 65.45 to 202.24 ng/g dry weight (dw), with an average of 142.73 ± 36.76 ng/g dw. The concentrations of these five classes of antibiotics were as follows: Sulfonamides (SAs) > Tetracyclines (TCs) > Fluoroquinolones (QUs) > Penicillin (PCs) > Macrolides (MLs). The spatial distribution of antibiotics varied as high tidal zone > middle tidal zone > low tidal zone. The total organic carbon (TOC), pH, nitrate (NO3--N), and nitrite (NO2--N) of the sediment significantly influenced the distribution of antibiotics (p < 0.05). A source analysis identified untreated sewage from aquaculture as the primary source of antibiotics in the local mangrove. A risk assessment revealed that ciprofloxacin, norfloxacin, ofloxacin of QUs, and tetracycline of TCs exhibited medium risks to algae in certain sampling sites, while other antibiotics exhibited low or no risks to all organisms. Nevertheless, the total risk of all the detected antibiotics to algae was medium in 95% of the sites. The overall ecological risk level of antibiotics in the middle tidal zone was slightly lower than in the high tidal zone and the lowest in the low tidal zone. In summary, the experimental results provided insights into the fate and transport behaviors of antibiotics in mangrove sediments from Lianzhou Bay.