Metagenomic perspectives on antibiotic resistance genes in tap water: The environmental characteristic, potential mobility and health threat.

As an emerging environmental contaminant, antibiotic resistance genes (ARGs) in tap water have attracted great attention. Although studies have provided ARG profiles in tap water, research on their abundance levels, composition characteristics, and potential threat is still insufficient. Here, 9 household tap water samples were collected from the Guangdong-Hong Kong-Macao Greater Bay Area (GBA) in China. Additionally, 75 sets of environmental sample data (9 types) were downloaded from the public database. Metagenomics was then performed to explore the differences in the abundance and composition of ARGs. 221 ARG subtypes consisting of 17 types were detected in tap water. Although the ARG abundance in tap water was not significantly different from that found in drinking water plants and reservoirs, their composition varied. In tap water samples, the three most abundant classes of resistance genes were multidrug, fosfomycin and MLS (macrolide-lincosamide-streptogramin) ARGs, and their corresponding subtypes ompR, fosX and macB were also the most abundant ARG subtypes. Regarding the potential mobility, vanS had the highest abundance on plasmids and viruses, but the absence of key genes rendered resistance to vancomycin ineffective. Generally, the majority of ARGs present in tap water were those that have not been assessed and are currently not listed as high-threat level ARG families based on the World Health Organization Guideline. Although the current potential threat to human health posed by ARGs in tap water is limited, with persistent transfer and accumulation, especially in pathogens, the potential danger to human health posed by ARGs should not be ignored.

Impact of bedaquiline regimen on the treatment success rates of multidrug-resistant tuberculosis patients in Egypt.

Bedaquiline (BDQ), an innovative anti-tuberculous (TB) agent, has attracted attention for its potential effectiveness against drug-resistant TB. This study investigated the impact of BDQ-containing regimens on treatment success rates among multi-drug resistant tuberculosis (MDR-TB) patients in Egypt. We conducted a prospective cohort study that included all adult non-pregnant patients treated in MDR-TB centers in Egypt from April 1, 2020, to June 30, 2021, with follow-up extended until December 31, 2022. The study compared patients prescribed BDQ according to national protocols with those receiving conventional treatments for MDR-TB. Treatment success rates, mortality rates, and adverse events were analyzed using descriptive statistics, chi-square tests, logistic regression, and Kaplan-Meier survival curves. Adjustment for potential confounders was conducted using propensity score matching and Cox-hazard regressions. A total of 84 patients were included in this study. The median age of the study participants was 39 years; 22.6% were women, 57.1% were unemployed or housewives, and 1.2% had human immunodeficiency virus (HIV). Regarding the treatment regimen, 67.8% were exposed to BDQ-based treatment. Among the 55 patients (65.5%) with treatment success, a significantly higher success rate was observed in the BDQ group (73.7%) compared to the conventional group (48.1%), P = 0.042. Additionally, the incidence of skin discoloration was significantly higher in the BDQ group compared to the conventional group (38.6% versus 0.0%, P < 0.001). Despite the lower mortality incidence in the BDQ-group (14.0% versus 22.2% in the conventional group), the Kaplan-Meier survival analysis revealed no excess mortality associated with the BDQ-group, with a hazard ratio (HR) of 0.62 (95% CI 0.21-1.78, P = 0.372). Propensity score matching, while considering factors such as lesion site, diabetes mellitus, hepatitis C virus, and smoking, revealed a significant increase in the success rate associated with BDQ inclusion, with an HR of 6.79 (95% CI 1.8-25.8). In conclusion, BDQ is an effective and tolerable medication for treating MDR-TB, associated with lower mortality rates compared to conventional treatment.

Epidemiology, outcomes and prognosis of infective endocarditis in Northern Morocco.

INTRODUCTION: Infective endocarditis is a rare but potentially severe disease, associated with significant morbidity and mortality. Our study aims to describe the epidemiology and management aspects of endocarditis in northern Morocco and compare it with international management guidelines. MATERIALS AND METHODS: This is a retrospective study involving all patients hospitalized in the cardiology department of the University Hospital of Tangier for infective endocarditis over a period of 4 years and 7 months, from May 2019 to February 2024. RESULTS: Eighty patients were hospitalized for IE during the study period. The average age of the patients was 46 years, with an even sex ratio. IE concerned native valves in 77% of cases, mechanical prostheses in 19% of cases, and on bio prostheses in 4%. The average diagnostic delay was 25 days. Blood cultures were negative in 59% of cases. The predominant infective microorganism was the bacteria Staphylococcus (65.6%). Imaging results showed vegetations in 76.3% of cases, predominantly on the mitral valve (39.3%), followed by the aortic valve (21.3%). The main complications included heart failure (51.2%), peripheral arterial embolisms (22.5%) and splenic infarction (17.5%). Management wise, the most commonly used antibiotic therapy was a combination of ceftriaxone and gentamicin. Clinical and biological improvement was observed in 70% of cases, with a mortality rate of 12.5%. Twelve patients underwent surgery (15%). Urgent surgery was indicated in 66,7% of the operated patients. CONCLUSION: Our study highlights the challenges in managing infective endocarditis in northern Morocco. The prognosis of infective endocarditis can be improved through multidisciplinary management within the implementation of an Endocarditis Team.

Pan-Genome Provides Insights into Vibrio Evolution and Adaptation to Deep-Sea Hydrothermal Vents.

This study delves into the genomic features of 10 Vibrio strains collected from deep-sea hydrothermal vents in the Pacific Ocean, providing insights into their evolutionary history and ecological adaptations. Through sequencing and pan-genome analysis involving 141 Vibrio species, we found that deep-sea strains exhibit larger genomes with unique gene distributions, suggesting adaptation to the vent environment. The phylogenomic reconstruction of the investigated isolates revealed the presence of 2 main clades: The first is monophyletic, consisting exclusively of Vibrio alginolyticus, while the second forms a monophyletic clade comprising both Vibrio antiquarius and Vibrio diabolicus species, which were previously isolated from deep-sea vents. All strains carry virulence and antibiotic resistance genes related to those found in human pathogenic Vibrio species which may play a wider ecological role other than host infection in these environments. In addition, functional genomic analysis identified genes potentially related to deep-sea survival and stress response, alongside candidate genes encoding for novel antimicrobial agents. Ultimately, the pan-genome we generated represents a valuable resource for future studies investigating the taxonomy, evolution, and ecology of Vibrio species.

Edible river fish-derived extended-spectrum ß-lactamase (ESBL)-producing Enterobacterales harboring transferable plasmids encoding bla CTX-M-15, bla CTX-M-27, and bla CTX-M-55.

Transmission of extended-spectrum ß-lactamase (ESBL) genes has increased the global prevalence of ESBL-producing bacteria, especially in developing countries. Human infection with these bacteria may be food-mediated but has not been fully elucidated. Therefore, we aimed to examine ESBL-producing bacteria in edible river fish and elucidate their potential for horizontal gene transfer. A total of 173 ESBL-producing Enterobacterales were isolated (Escherichia coli [n = 87], Klebsiella pneumoniae [n = 52], Enterobacter cloacae complex [n = 18], Citrobacter freundii complex [n = 14], Atlantibacter hermannii [n = 1] and Serratia fonticola [n = 1]) from 56 of 80 fish intestinal contents sampled. Among the bacterial bla CTX-M genotypes, bla CTX-M-55 was the most predominant, followed by bla CTX-M-15, bla CTX-M-27, and bla CTX-M-65. Furthermore, we found that ESBL-producing Enterobacterales were able to transfer their bla CTX-M genes to E. coli. In summary, our results suggest that ESBL-producing Enterobacterales transfer bla CTX-M to indigenous gut E. coli in humans, following the consumption of contaminated fish.

Antimicrobial resistance in food-borne pathogens at the human-animal interface: Results from a large surveillance study in India.

Background: The burden of foodborne diseases and antimicrobial resistance carried by key foodborne pathogens in India is unknown due to a lack of an integrated surveillance system at the human-animal interface. Methods: We present data from the WHO-AGISAR (Advisory Group on Integrated Surveillance of Antimicrobial Resistance), India project. Concurrent human and animal sampling was done across a large area across north India. Community-acquired diarrhea cases (n = 1968) of all age groups were included. Cross-sectional sampling of stool/ intestinal contents (n = 487) and meat samples (n = 419) from food-producing animals was done at farms, retail shops, and slaughterhouses. Pathogens were cultured and identified, and antimicrobial susceptibility was performed. Results: Over 80% of diarrhoeal samples were obtained from moderate to severe diarrhea patients, which yielded EAEC (5%), ETEC (4.84%), EPEC (4.32%), and Campylobacter spp. (2%). A high carriage of EPEC (32.11%) and Campylobacter spp. (24.72%) was noted in food animals, but the prevalence of ETEC (2%) and EAEC (1%) was low. Atypical EPEC (aEPEC, 84.52%, p ≤0.0001) were predominant and caused milder diarrhea. All EPEC from animal/poultry were aEPEC. Overall, a very high level of resistance was observed, and the MDR rate ranged from 29.2% in Campylobacter spp., 53.6% in EPEC, and 59.8% in ETEC. Resistance to piperacillin-tazobactam, cefepime, ceftriaxone, and co-trimoxazole was significantly higher in human strains. In contrast, resistance to ciprofloxacin, aminoglycosides, and tetracycline was higher in animal strains, reflecting the corresponding usage in human and animal sectors. ESBL production was commoner in animal isolates than in humans, indicating high use of third-generation cephalosporins in the animal sector. C. hyointestinalis is an emerging zoonotic pathogen, first time reported from India. Conclusion: In one of the most extensive studies from India, a high burden of key foodborne pathogens with MDR and ESBL phenotypes was found in livestock, poultry, and retail meat.

Detection of Changes in Soil Microbial Community Physiological Profiles in Relation to Forest Types and Presence of Antibiotics Using BIOLOG EcoPlate.

Soil is home to microbiota with diverse metabolic activities. These microorganisms play vital roles in many ecological processes. Thus, the assessment of microbial functional diversity is an important quality indicator of soil ecosystems. In this study, we collected soil samples from three distinct forest habitats, i.e., an agroforest, a primary forest (PF), and a secondary forest, within the Angat Watershed Reservation in Bulacan, Northern Philippines. Community-level physiological profiling (CLPP) was done with the BIOLOG EcoPlate™ to analyze the responses of the soil microbial communities from the three forest habitats in the absence or presence of antibiotics. The BIOLOG EcoPlate represents 31 utilizable carbon sources. Based on the CLPP analysis, soil samples from the PF showed significantly higher utilization of most carbon sources than the other forest types (p < 0.05). Thus, less disturbed forest types constitute more functionally diverse microbial communities. The presence of antibiotics significantly decreased the carbon utilization patterns of the soil microbial communities (p < 0.05), indicating the possible use of CLPP in monitoring contamination in soil.

A Systemic Review on Fitness and Survival of Salmonella in Dynamic Environment and Conceivable Ways of Its Mitigation.

Gastroenteritis caused by non-typhoidal Salmonella still prevails resulting in several recent outbreaks affecting many people worldwide. The presence of invasive non-typhoidal Salmonella is exemplified by several characteristic symptoms and their severity relies on prominent risk factors. The persistence of this pathogen can be attributed to its broad host range, complex pathogenicity and virulence and adeptness in survival under challenging conditions inside the host. Moreover, a peculiar aid of the ever-changing climatic conditions grants this organism with remarkable potential to survive within the environment. Abusive use of antibiotics for the treatment of gastroenteritis has led to the emergence of multiple drug resistance, making the infections difficult to treat. This review emphasizes the importance of early detection of Salmonella, along with strategies for accomplishing it, as well as exploring alternative treatment approaches. The exceptional characteristics exhibited by Salmonella, like strategies of infection, persistence, and survival parallelly with multiple drug resistance, make this pathogen a prominent concern to human health.

The Prevalence of Multidrug-Resistant Escherichia coli in Chennai and Whole Genome Sequence Analysis of Carbapenem-Resistant Escherichia coli ST410.

The current study evaluates antibiotic susceptibility and Extended Spectrum ß-Lactamase (ESBL) production of 557 Escherichia coli isolates obtained from clean catch midstream urine samples using VITEK 2 compact automated microbial identification system. Different classes of drugs were used to determine the Minimum inhibitory concentration (MIC). In our study, 50.45% of isolates were ESBL producers. There is a higher incidence of UTI in females (77.4%) than in males (22.6%). The isolates reveal a high percentage of resistance to antibiotics like nalidixic acid (89.59%), ampicillin (75.76%), ticarcillin (73.43%), cefalotin (67.68%), cefixime (65.17%), ciprofloxacin (58.35%) and ceftriaxone (56.37%). An increased susceptibility pattern was observed for the isolates against drug classes like fosfomycin (98.03%) and nitrofurantoin (91.02%). Among the isolates, 395 (70.91%) were classified as Multidrug-resistant organisms based on the resistance pattern observed against three or more classes of antibiotics. One of the isolates resistant to fluoroquinolones, penicillins, penicillins along with ß-lactamase inhibitor, aminoglycosides, third-generation cephalosporins and carbapenems was subjected to Whole genome sequencing (WGS). WGS data revealed the isolate to be a high-risk clone ST410, which contains antimicrobial-resistance genes (blaTEM-1B, blaCTX-M-15, blaNDM-5, aac(3)-IId, armA, gyrA(p.S83L), gyrA(p.D87N)) conferring resistance to ß-lactam, cephalosporins, carbapenem, aminoglycoside and fluoroquinolone class of antibiotics. The core genome MLST was carried out using BacWGSTdb to assess the global phylogenetic relationship of the genome sequence. Supplementary Information: The online version contains supplementary material available at 10.1007/s12088-023-01125-1.

The FinO/ProQ-like protein PA2582 impacts antimicrobial resistance in Pseudomonas aeruginosa.

Bacteria employ small regulatory RNAs (sRNA) and/or RNA binding proteins (RBPs) to respond to environmental cues. In Enterobacteriaceae, the FinO-domain containing RBP ProQ associates with numerous sRNAs and mRNAs, impacts sRNA-mediated riboregulation or mRNA stability by binding to 5'- or 3'-untranslated regions as well as to internal stem loop structures. Global RNA-protein interaction studies and sequence comparisons identified a ProQ-like homolog (PA2582/ProQ Pae ) in Pseudomonas aeruginosa (Pae). To address the function of ProQ Pae , at first a comparative transcriptome analysis of the Pae strains PAO1 and PAO1ΔproQ was performed. This study revealed more than 100 differentially abundant transcripts, affecting a variety of cellular functions. Among these transcripts were pprA and pprB, encoding the PprA/PprB two component system, psrA, encoding a transcriptional activator of pprB, and oprI, encoding the outer membrane protein OprI. RNA co-purification experiments with Strep-tagged Pae ProQ protein corroborated an association of ProQ Pae with these transcripts. In accordance with the up-regulation of the psrA, pprA, and pprB genes in strain PAO1ΔproQ a phenotypic analysis revealed an increased susceptibility toward the aminoglycosides tobramycin and gentamicin in biofilms. Conversely, the observed down-regulation of the oprI gene in PAO1ΔproQ could be reconciled with a decreased susceptibility toward the synthetic cationic antimicrobial peptide GW-Q6. Taken together, these studies revealed that ProQ Pae is an RBP that impacts antimicrobial resistance in Pae.

Doctors' perception on the ethical use of AI-enabled clinical decision support systems for antibiotic prescribing recommendations in Singapore.

Objectives: The increased utilization of Artificial intelligence (AI) in healthcare changes practice and introduces ethical implications for AI adoption in medicine. We assess medical doctors' ethical stance in situations that arise in adopting an AI-enabled Clinical Decision Support System (AI-CDSS) for antibiotic prescribing decision support in a healthcare institution in Singapore. Methods: We conducted in-depth interviews with 30 doctors of varying medical specialties and designations between October 2022 and January 2023. Our interview guide was anchored on the four pillars of medical ethics. We used clinical vignettes with the following hypothetical scenarios: (1) Using an antibiotic AI-enabled CDSS's recommendations for a tourist, (2) Uncertainty about the AI-CDSS's recommendation of a narrow-spectrum antibiotic vs. concerns about antimicrobial resistance, (3) Patient refusing the "best treatment" recommended by the AI-CDSS, (4) Data breach. Results: More than half of the participants only realized that the AI-enabled CDSS could have misrepresented non-local populations after being probed to think about the AI-CDSS's data source. Regarding prescribing a broad- or narrow-spectrum antibiotic, most participants preferred to exercise their clinical judgment over the AI-enabled CDSS's recommendations in their patients' best interest. Two-thirds of participants prioritized beneficence over patient autonomy by convincing patients who refused the best practice treatment to accept it. Many were unaware of the implications of data breaches. Conclusion: The current position on the legal liability concerning the use of AI-enabled CDSS is unclear in relation to doctors, hospitals and CDSS providers. Having a comprehensive ethical legal and regulatory framework, perceived organizational support, and adequate knowledge of AI and ethics are essential for successfully implementing AI in healthcare.

One Health Threat of Treated Wastewater Discharge in Urban Ohio Rivers: Implications for Surface Water and Fish Gut Microbiome and Resistome.

Wastewater treatment plants (WWTPs) are thought to be a major disseminating source of antibiotic resistance (AR) to the environment, establishing a crucial connection between human and environmental resistome. The objectives of this study were to determine how wastewater effluents impact microbiome and resistome of freshwater and fish, and identify potential AR-carrying clinically relevant pathogens in these matrices. We analyzed wastewater influent and effluent from four WWTPs in three metropolitan areas of Ohio, USA via shotgun metagenomic sequencing. We also sequenced river water and fish guts from three reaches (upstream, at the WWTP outfall, and downstream). Notably, we observed a decline in microbiome diversity and AR gene abundance from wastewater to the receiving river. We also found significant differences by reach and trophic level (diet) in beta-diversity of the fish gut microbiomes. SourceTracker revealed that 0.443 and 0.248 more of the of the fish gut microbiome was sourced from wastewater effluent in fish from the outfall and downstream locations, respectively, compared to upstream fish. Additionally, AR bacteria of public health concern were annotated in effluent and river water samples, indicating potential concern for human exposure. In summary, our findings show the continued role of wastewater as a significant AR reservoir and underscores the considerable impact of wastewater discharge on aquatic wildlife, which highlights the One Health nature of this issue.

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OBJECTIVES: To develop effective measures to reduce antibiotic use duration in very low birth weight (VLBW) preterm infants in the neonatal intensive care unit through quality improvement methods. METHODS: The study population consisted of hospitalized VLBW preterm infants, with the percentage of hospitalization time during which antibiotics were used from November 2020 to June 2021 serving as the baseline. The specific quality improvement goal was to reduce the duration of antibiotic use. Factors affecting antibiotic use duration in preterm infants were analyzed using Pareto charts. Key drivers were identified, and specific interventions were formulated based on the stages of antibiotic use. Changes in the percentage of antibiotic use duration were monitored with run charts until the quality improvement target was achieved. RESULTS: From November 2020 to June 2021, the baseline antibiotic use duration percentage was 49%, with a quality improvement target to reduce this by 10% within 12 months. The Pareto analysis indicated that major factors influencing antibiotic duration included non-standard antibiotic use; delayed cessation of antibiotics when no infection evidence was present; prolonged central venous catheter placement; insufficient application of kangaroo care; and delayed progress in enteral nutrition. The interventions implemented included: (1) establishing sepsis evaluation and management standards; (2) educating medical staff on the rational use of antibiotics for preterm infants; (3) supervising the enforcement of antibiotic use standards during ward rounds; (4) for those without clear signs of infection and with negative blood cultures, discontinued the use of antibiotics 36 hours after initiation; (5) reducing the duration of central venous catheterization and parenteral nutrition to lower the risk of infection in preterm infants. The control chart showed that with continuous implementation of interventions, the percentage of antibiotic use duration was reduced from 49% to 32%, a statistically significant decrease. CONCLUSIONS: The application of quality improvement tools based on statistical principles and process control may significantly reduce the antibiotic use duration in VLBW preterm infants. Citation:Chinese Journal of Contemporary Pediatrics, 2024, 26(7): 736-742.

Phage therapy: an alternative treatment modality for MDR bacterial infections.

The increasing global incidence of multidrug-resistant (MDR) bacterial infections threatens public health and compromises various aspects of modern medicine. Recognising the urgency of this issue, the World Health Organisation has prioritised the development of novel antimicrobials to combat ESKAPEE pathogens. Comprising Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. and Escherichia coli, such pathogens represent a spectrum of high to critical drug resistance, accounting for a significant proportion of hospital-acquired infections worldwide. In response to the waning efficacy of antibiotics against these resilient pathogens, phage therapy (PT) has emerged as a promising therapeutic strategy. This review provides a comprehensive summary of clinical research on PT and explores the translational journey of phages from laboratory settings to clinical applications. It examines recent advancements in pre-clinical and clinical developments, highlighting the potential of phages and their proteins, alone or in combination with antibiotics. Furthermore, this review underlines the importance of establishing safe and approved routes of phage administration to patients. In conclusion, the evolving landscape of phage therapy offers a beacon of hope in the fight against MDR bacterial infections, emphasising the imperative for continued research, innovation and regulatory diligence to realise its full potential in clinical practice.

Unraveling the effect of micro/nanoplastics on the occurrence and horizontal transfer of environmental antibiotic resistance genes: Advances, mechanisms and future prospects.

Microplastics can not only serve as vectors of antibiotic resistance genes (ARGs), but also they and even nanoplastics potentially affect the occurrence of ARGs in indigenous environmental microorganisms, which have aroused great concern for the development of antibiotic resistance. This article specifically reviews the effects of micro/nanoplastics (concentration, size, exposure time, chemical additives) and their interactions with other pollutants on environmental ARGs dissemination. The changes of horizontal genes transfer (HGT, i.e., conjugation, transformation and transduction) of ARGs caused by micro/nanoplastics were also summarized. Further, this review systematically sums up the mechanisms of micro/nanoplastics regulating HGT process of ARGs, including reactive oxygen species production, cell membrane permeability, transfer-related genes expression, extracellular polymeric substances production, and ARG donor-recipient adsorption/contaminants adsorption/biofilm formation. The underlying mechanisms in changes of bacterial communities induced by micro/nanoplastics were also discussed as it was an important factor for structuring the profile of ARGs in the actual environment, including causing environmental stress, providing carbon sources, forming biofilms, affecting pollutants distribution and environmental factors. This review contributes to a systematical understanding of the potential risks of antibiotic resistance dissemination caused by micro/nanoplastics and provokes thinking about perspectives for future research and the management of micro/nanoplastics and plastics.

Aspirin altered antibiotic resistance genes response to sulfonamide in the gut microbiome of zebrafish.

Pharmaceuticals are widespread in aquatic environments and might contribute to the prevalence of antibiotic resistance. However, the co-effect of antibiotics and non-antibiotic pharmaceuticals on the gut microbiome of fish is poorly understood. In this study, we characterized the variation of the zebrafish gut microbiome and resistome after exposure to sulfamethoxazole (SMX) and aspirin under different treatments. SMX contributed to the significant increase in the antibiotic resistance genes (ARGs) richness and abundance with 46 unique ARGs and five mobile genetic elements (MGEs) detected. Combined exposure to SMX and aspirin enriched total ARGs abundance and rearranged microbiota under short-term exposure. Exposure time was more responsible for resistome and the gut microbiome than exposure concentrations. Perturbation of the gut microbiome contributed to the functional variation related to RNA processing and modification, cell motility, signal transduction mechanisms, and defense mechanisms. A strong significant positive correlation (R=0.8955, p<0.001) was observed between total ARGs and MGEs regardless of different treatments revealing the key role of MGEs in ARGs transmission. Network analysis indicated most of the potential ARGs host bacteria belonged to Proteobacteria. Our study suggested that co-occurrence of non-antibiotics and antibiotics could accelerate the spread of ARGs in gut microbial communities and MGEs played a key role.

Utilizing nutrient type compounds as anti-bacterial compounds: arginine and cysteine inhibit Salmonella survival in egg white.

Because of growing levels of antibiotic resistance, new methods to combat bacteria are needed. We hypothesized that because bacteria evolved to survive in specific environments, the addition of compounds, including nutrient type compounds, to an environment, might result in a modification of that environment that will disrupt bacterial growth or in maladaptive bacterial behavior, i.e., gene expression. As a proof of concept, we focused on the egg white environment and the pathogen Salmonella. Despite egg white's antibacterial nature, Salmonella is able to survive and grow in egg white, and this ability of Salmonella leads to infection of chicks and humans. Here, the 20 L-amino-acids were screened for their ability to affect the growth of Salmonella in egg white. L-arginine and L-cysteine were found to reduce growth in egg white in physiologically relevant concentrations. To determine the mechanism behind L-arginine inhibition TnSeq was utilized. TnSeq identified many Salmonella genes required for survival in egg white including genes required for iron import, biotin synthesis, stress responses, cell integrity, and DNA repair. However, a comparison of Salmonella in egg white with and without L-arginine identified only a few differences in the frequency of transposon insertions, including the possible contribution of perturbations in the cell envelope to the inhibition mechanism. Finally, both D-arginine and D-cysteine were found to inhibit Salmonella in egg white. This implied that the effect of arginine and cysteine in egg white is chemical rather than biological, likely on the egg white environment or on the bacterial outer membrane. To conclude, these results show that this approach of addition of compounds, including nutrient type compounds, to an environment can be used to limit bacterial growth. Importantly, these compounds have no inherent anti-bacterial properties, are used as nutrients by animals and bacteria, and only become anti-bacterial in a specific environmental context. Future research screening for the effects of compounds in relevant environments might uncover new ways to reduce pathogen levels in the poultry industry and beyond.

Impact of Selective Reporting of Antibiotic Susceptibility Test Results on Antibiotic Use in Patients with Bloodstream Infection with Streptococcus pneumoniae.

Introduction: Invasive pneumococcal disease is a major cause of morbidity and mortality in infectious diseases. Selective reporting of antibiotic susceptibility test results might lead to a tailored antibiotic therapy and could therefore be an important antibiotic stewardship program intervention. The aim of this study was to analyse whether a switch to selective reporting of antibiotic test results leads to a more focused antibiotic therapy in patients with a bloodstream infection with Streptococcus pneumoniae. Methods: This study was performed as a retrospective cohort study at the University Hospital Regensburg, Germany. All blood cultures positive for Streptococcus pneumoniae between 2006 and 2021 were analysed. In 2014, a switch to selective reporting of antibiotic susceptibility test results omitting sensitivity results for agents not recommended was introduced. Results: Twenty-four hours after final antibiotic susceptibility test results were available, 20.9% before (BI) versus 15.4% after implementation (AI) of selective reporting of antibiotic test results received a narrow-spectrum penicillin, while only 2.3% BI versus 5.8% AI received a narrow-spectrum penicillin from the beginning. Conclusion: Selective reporting of antibiotic susceptibility test results without further antimicrobial stewardship interventions did not lead to a higher use of a narrow-spectrum penicillin in this study.

Photodynamic inactivation of antibiotic-resistant bacteria in whole blood using riboflavin photodynamic method.

Treating bacteremia caused by antibiotic-resistant bacteria is a global concern. Antibacterial photodynamic inactivation is a promising strategy to combat it. However, it's challenging to achieve the inactivation of antibiotic-resistant bacteria in whole blood because of its opacity and complexity. We investigated a riboflavin photodynamic method to effectively inactivate antibiotic-resistant bacteria in whole blood. Four strains of antibiotic-resistant bacteria were isolated, identified, and cultured in this research: methicillin-resistant Staphylococcus aureus (MRSA), pan-drug-resistant Acinetobacter baumannii (PDRAB), ESBLs-producing Escherichia coli (EPEC) and pan-drug-resistant Klebsiella pneumoniae (PDRKP). To simulate bacteremia, antibiotic-resistant bacteria was added into whole blood. Whole blood was treated using riboflavin photodynamic method with ultraviolet irradiation (308 nm and 365 nm). The ultraviolet irradiation dose was divided into 18 J/cm2, 36 J/cm2, and 54 J/cm2. Microbial count of antibiotic-resistant bacteria in whole blood was used for evaluating inactivation effectiveness. The roles of red blood cells, lymphocytes, coagulation factors, and platelets in whole blood were assessed. In results, inactivation effectiveness increased as the ultraviolet dose increased from 18 J/cm2 to 54 J/cm2. At the dose of 18 J/cm2, inactivation effectiveness of four antibiotic-resistant bacteria were more than 80%, while only 67% of MRSA. The antibacterial effect was enhanced by the combination of riboflavin photodynamic treatment and antibiotic. The red blood cell function was susceptible to ultraviolet dose. At the dose of 18 J/cm2, hemolysis rate was less than 0.8% and there was no change in levels of ATP and 2,3-DPG. At the same dose, the proliferation, cell killing, and cytokine secretion activities of lymphocytes decreased 20-70%; Factor V and Factor VIII activities decreased 50%; Fibrinogen and platelet function loss significantly but reparable. Consequently, we speculated that riboflavin photodynamic method with a ultraviolet dose of 18 J/cm2 was effective in inactivating four antibiotic-resistant bacteria in whole blood while whole blood function was preserved. We also provided a novel extracorporeal circulation phototherapy mode for treating bacteremia caused by antibiotic-resistant bacteria.

Distribution of the active components from Xianglian Pill in tissues of healthy and antibiotic-associated diarrhea model mice and the mechanism study.

Antibiotic-associated diarrhea (AAD) is a common side effect of antibiotic therapy, characterized by intestinal inflammation which reduces the quality of life of patients. Xianglian Pill (XLP) has long been used to treat abdominal pain, diarrhea, bacillary dysentery and enteritis. Studies found that XLP has curative effect on AAD; however, the chemical constituents and mechanism of XLP have not been fully elucidated because of the lack of in vitro and in vivo studies. In this study, ultra-high performance liquid chromatography mass spectrometry method (UPLC-Q-Exactive-Orbitrap-HRMS) was used to examine the components of the XLP. Then, the binding between active compounds and the key targets was studied using network pharmacology and molecular docking. A comparative tissue distribution study was established for the simultaneous determination of the 10 active components in healthy and AAD mouse models. Forty-six components were characterized from XLP. According to the network pharmacology degree value, a prediction was made that encompassed 42 components and 14 core targets, which were intricately involved in crucial biological pathways, such as the AGE-RAGE signaling, cellular senescence, and MAPK signaling. Tissue distribution analysis showed that the 10 components were widely distributed in the heart, liver, spleen, lungs, kidneys, small intestine, and large intestine of mice, with varying concentrations in healthy and AAD mice. Molecular docking analysis also indicated that the active compounds in the tissue distribution could bind tightly to key targets of network pharmacological studies. This study provides a reference for further investigations of the relationships between the chemical components and pharmacological activities of XLP.