Global Threat Of Antimicrobial Resistance Research Articles

Unlocking the therapeutic potential of Nigella sativa extract: phytochemical analysis and revealing antimicrobial and antioxidant marvels

The growing global threat of antimicrobial resistance endangers both human and animal life, necessitating the urgent discovery of novel antimicrobial solutions. Medicinal plants hold promise as sources of potential antimicrobial compounds. In this study, we investigated the phytochemical constituents and microbicidal capabilities of the ethanolic extract from Nigella sativa (black seed). Gas chromatography analysis (GC) identified 11 compounds, among them thymoquinone, and thymol, contributing to antimicrobial and antioxidant properties. Antimicrobial assays demonstrated notable inhibition zones against broad spectra of bacteria, including Pseudomonas aeruginosa, Escherichia coli, Salmonella typhi, Staphylococcus aureus, Enterobacter, and Bacillus subtilis, along with potent antifungal activity against Aspergillus niger, Penicillium, and Candida albicans. Notably, when combined with antibiotics, the extract displayed exceptional synergistic antimicrobial efficacy. The black seed extract demonstrated membrane-damaging activity and disrupted virulence factors that protect microbes from antimicrobial agents, including the formation of bacterial biofilm and protease secretion. Thymoquinone, the primary active constituent of the extract, exhibited similar antimicrobial and ant virulence properties. In silico analysis targeting key regulators of quorum sensing and biofilm formation in P. aeruginosa, such as RhlG, LasR, and PqsR, showed a remarkable affinity of thymol and thymoquinone for these targets. Moreover, the N. sativa extract exhibited dose-dependent cytotoxicity against both the promastigote and amastigote forms of Leishmania tropica parasites, hinting at potential antiparasitic activity. In addition to its antimicrobial properties, the extract displayed potential antioxidant activity at a concentration of 400 μg/mL.

In-hospital use of antibiotics in internal medicine: A cross-sectional study before, during and after the COVID-19 pandemic in a COVID-19-free ward

BackgroundCoronavirus Disease-19 (COVID-19) pandemic impacted the use of antibiotics in hospitalized patients. However, most data on antibiotic therapy (AT) were recorded in COVID-19 settings. This study analyzed the appropriateness of AT in the real-world scenario of a COVID-19-free internal medicine ward before, during, and after the pandemic. MethodsClinical information of hospitalized patients was collected, and data related to AT prescription were analyzed. The appropriateness of AT was independently assessed by two specialists in internal medicine and infectious disease, combining evidence-based guidelines with a validated tool. ResultsRecords of 1249 patients were analyzed: AT was prescribed in 229 (55.2 %) patients before, 134 (53.2 %) patients during, and 315 (54.1 %) patients after COVID-19 pandemic. Compared to the pre-pandemic period, there was a decrease in monotherapy with 3rd and 4th generation cephalosporins and fluoroquinolones, and an increase in β-lactams + β-lactamase inhibitors and antibiotic combinations. Furthermore, AT was longer and more expensive during the pandemic, with duration and cost remaining higher after its end. The inappropriateness of AT increased during and after COVID-19 pandemic. Compared to the pre-pandemic period, inappropriate AT was longer and more expensive than appropriate AT. The COVID-19 pandemic had a significant impact on changes related to AT type and antibiotic classes. ConclusionsThe COVID-19 pandemic increased the inappropriateness of AT in a COVID-19-free internal medicine ward. Most modifications persist despite the end of pandemic, potentially leading to negative effects on in-hospital antimicrobial resistance. There is an urgent need to re-establish antimicrobial stewardship policies to address the longer-term global threat of antimicrobial resistance.

Molecular surveillance of carbapenem-resistant Enterobacterales in two nearby tertiary hospitals to identify regional spread of high-risk clones in Germany, 2019–2020

Understanding the transmission dynamics of carbapenem-resistant Enterobacterales (CRE) is critical to addressing the escalating global threat of antimicrobial resistance (AMR). Although hospital transmission of CRE has been extensively studied, information on community transmission is lacking. This study aims to identify genomic clusters of CRE from two nearby institutions that may be indicative of community or inter-facility transmission. CRE isolates between 1st of January 2019 and 31st of December 2020 from two tertiary hospitals, detected in the respective routine microbiology laboratories, were collected and characterized by short-read whole genome sequencing. A total of 272 CRE were collected, with Enterobacter cloacae complex (71/192, 37%) predominant in Heidelberg and Escherichia coli (19/80, 24%) in Mannheim. The most common carbapenem resistance gene, blaOXA-48, was detected in 38% of CRE from both centres. Several putative transmission clusters were found, including 6 clusters of E. cloacae complex, 5 clusters of Klebsiella pneumoniae, 4 clusters of Citrobacter freundii, and 2 clusters each of Escherichia coli and K. aerogenes. No clusters involved isolates from both study centres, except for an ST22 C. freundii cluster. Globally circulating clones were identified between the two centres for ST131 E. coli, ST66 E. hormaechei and ST22 C. freundii. This study found no widespread transmission clusters among isolates from both centres, suggesting a hospital-specific clonal structure. This suggests that CRE clusters involving both institutions may indicate emerging or circulating clones in the community, highlighting the need for intersectoral surveillance and data sharing.

Vesicle protrusion induced by antimicrobial peptides suggests common carpet mechanism for short antimicrobial peptides

Short-cationic alpha-helical antimicrobial peptides (SCHAMPs) are promising candidates to combat the growing global threat of antimicrobial resistance. They are short-sequenced, selective against bacteria, and have rapid action by destroying membranes. A full understanding of their mechanism of action will provide key information to design more potent and selective SCHAMPs. Molecular Dynamics (MD) simulations are invaluable tools that provide detailed insights into the peptide-membrane interaction at the atomic- and meso-scale level. We use atomistic and coarse-grained MD to look into the exact steps that four promising SCHAMPs—BP100, Decoralin, Neurokinin-1, and Temporin L—take when they interact with membranes. Following experimental set-ups, we explored the effects of SCHAMPs on anionic membranes and vesicles at multiple peptide concentrations. Our results showed all four peptides shared similar binding steps, initially binding to the membrane through electrostatic interactions and then flipping on their axes, dehydrating, and inserting their hydrophobic moieties into the membrane core. At higher concentrations, fully alpha-helical peptides induced membrane budding and protrusions. Our results suggest the carpet mode of action is fit for the description of SCHAMPs lysis activity and discuss the importance of large hydrophobic residues in SCHAMPs design and activity.

Wild birds and the ecology of antimicrobial resistance: an approach to monitoring

AbstractTackling the global threat of antimicrobial resistance (AMR) requires joint efforts according to the principles of the One Health approach. In this context, wildlife, and especially wild birds, are recognized as an important bridge between environment, humans and livestock in perpetuating AMR. Over the last decades, important progress has been made in understanding the role of wild birds as carriers of antibiotic‐resistant bacteria and their genes (ARGs) within ecosystems; however, there are still many knowledge gaps regarding transmission sources and routes. This commentary summarizes studies from recent years focusing on AMR in wild birds, highlighting the most frequently found zoonotic bacteria harboring ARGs and the possible exchange scenarios between humans, livestock, and wild birds. We emphasize the need to standardize and optimize a wild bird monitoring approach for AMR surveillance that includes non‐invasive sampling methods, culture‐independent techniques for identification of ARGs, database integration and implementation, and machine learning technology. This multidisciplinary perspective, which could involve veterinarians, biologists, ornithologists, conservationists, and managers, may represent part of the solution, not only for wildlife conservation but also for global health, considering that the goal is to reverse the route of AMR.

Tapping the biosynthetic potential of marine Bacillus licheniformis LHG166, a prolific sulphated exopolysaccharide producer: structural insights, bio-prospecting its antioxidant, antifungal, antibacterial and anti-biofilm potency as a novel anti-infective lead.

The escalating global threat of antimicrobial resistance necessitates prospecting uncharted microbial biodiversity for novel therapeutic leads. This study mines the promising chemical richness of Bacillus licheniformis LHG166, a prolific exopolysaccharide (EPSR2-7.22 g/L). It comprised 5 different monosaccharides with 48.11% uronic acid, 17.40% sulfate groups, and 6.09% N-acetyl glucosamine residues. EPSR2 displayed potent antioxidant activity in DPPH and ABTS+, TAC and FRAP assays. Of all the fungi tested, the yeast Candida albicans displayed the highest susceptibility and antibiofilm inhibition. The fungi Aspergillus niger and Penicillium glabrum showed moderate EPSR2 susceptibility. In contrast, the fungi Mucor circinelloides and Trichoderma harzianum were resistant. Among G+ve tested bacteria, Enterococcus faecalis was the most susceptible, while Salmonella typhi was the most sensitive to G-ve pathogens. Encouragingly, EPSR2 predominantly demonstrated bactericidal effects against both bacterial classes based on MBC/MIC of either 1 or 2 superior Gentamicin. At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 88.30% against B. subtilis, while for G-ve antibiofilm inhibition, At 75% of MBC, EPSR2 displayed the highest anti-biofilm activity of 96.63% against Escherichia coli, Even at the lowest dose of 25% MBC, EPSR2 reduced biofilm formation by 84.13% in E. coli, 61.46% in B. subtilis. The microbial metabolite EPSR2 from Bacillus licheniformis LHG166 shows promise as an eco-friendly natural antibiotic alternative for treating infections and oxidative stress.

Use of antimicrobials and other medical products in an ethnic minority context of South-Central Vietnam: A qualitative study of vulnerability.

Despite the global threat of antimicrobial resistance (AMR), evidence on the use and quality of medicines at community level is limited, particularly in impoverished, rural areas where prevalence of (bacterial) infections is high. To better understand the processes that drive vulnerability to AMR' effects, this study aimed to assess social factors underpinning access to-and use of-medical products and healthcare, among people from the Raglai ethnic minority in Ninh Thuan Province, Vietnam. We conducted ethnographic research in eight villages in 2018-2019, using interviewing and participant observation methods for data collection. Different types of informants (including community members and healthcare providers) were selected using purposive sampling strategies and analysis was retroductive. Our findings show that, despite the existence of a government-funded health insurance scheme, Raglai people's flexible therapeutic itineraries did not systematically start with formal healthcare. Different types of care (private/informal, public, shamanic) were combined in parallel or in alternation, determined by distance to the provider, cost, workload, perceived diagnostic capacity, perceived severity and aetiology of the illness, and trust in the provider. Available medicines were often tablets dispensed in plastic bags containing labelled tablets, unlabelled tablets (in bulk) or tablets ground to powder. Treatment was often considered effective when it relieved symptoms, which led to abandonment of the treatment course. When symptoms did not speedily abate, the illness aetiology would be reinterpreted, and "stronger" medicines would be sought. The precarious socio-economic status of some Raglai drove them in cycles of severe poverty when additional unforeseen factors such as illness, animal disease or loss of crops arose, hampering access to (in)formal healthcare providers and/or appropriate diagnosis and treatment. We conclude that Raglai communities are structurally unable to buffer themselves against the threat and consequences of AMR. Despite this vulnerability, they are among the least targeted by efforts to optimize antibiotic use, which are concentrated in secondary and tertiary healthcare facilities targeted at urban populations.

Towards monitoring the invisible threat: a global approach for tackling AMR in water resources and environment

The global threat of antimicrobial resistance (AMR) is now increasingly recognized for the danger posed by its environmental spread. Aquatic environments and wastewater represent a significant diffusion and selection pathway for antibiotic resistance genes and antibiotic resistant bacteria (ARGs and ARBs). During a collaborative hackathon event, the “Innovation Workshop on Water Quality Monitoring & Assessment,” held in September 2023, experts addressed four challenges related to water quality, including the challenge of globalization AMR surveillance in water. This paper, derived from the workshop findings, proposes a globally adaptable model for antimicrobial resistance surveillance intended as an advance to improve future monitoring systems. The new framework aims to address significant challenges, such as the lack of standardized methodological approaches or lack of funding, coordination, and awareness across a short-, medium- and long-term plan, integrating sustainability concepts, extending participation and monitoring capacity of countries, and offering efficient solutions. This vision is first articulated by creating a technical committee that promotes awareness of antimicrobial resistance and develops a single data management and communication platform. Subsequently, by developing local, national, and international policies, centralized laboratories will be established at the regional level, and built based on existing realities. These laboratories will include facilities to make the management of analyses more efficient, from sampling to reporting the final result. In the long term, activities that allow the maintenance of the created framework and continuous technological development and advancement will be promoted. All this will be achieved in collaboration with national and supranational bodies that are already addressing the issue at a global level.

Use of Antibiotics in Tertiary Care Hospitals of Meteropolitan City Islamabad

Background: The global threat of antimicrobial resistance (AMR) necessitates a deeper understanding of antibiotic use patterns within healthcare settings. Previous studies have indicated variable prevalence rates of antibiotic use across different regions, underscoring the need for localized data to inform antimicrobial stewardship initiatives. Objective: This study aimed to determine the prevalence and patterns of antibiotic use in two tertiary care hospitals in Islamabad, Pakistan, to identify opportunities for improving antibiotic prescribing practices and inform the development of targeted antimicrobial stewardship programs. Methods: A descriptive cross-sectional study was conducted through a point prevalence survey in two tertiary care hospitals over three months, from January to March 2022. Data on antibiotic use were collected from patient files, employing a two-stage random sampling method for both hospital and ward selection. The survey assessed the prevalence of antibiotic use, categorized according to the WHO Aware classification (Access, Watch, Reserve, Not Recommended), and analyzed the indications, dosages, routes of administration, and compliance with prescribing guidelines. Statistical analysis was performed using SPSS version 25. Results: The prevalence of antibiotic use among the surveyed population (n=255) was 78%, with a higher prevalence observed in neonatal (100%) and pediatric (100%) departments compared to the adult department (74.66%). Ceftriaxone (27.06%), meropenem (10.98%), and moxifloxacin (9.41%) were the most frequently used antibiotics. The majority of antibiotics prescribed belonged to the 'Watch' group (70%), with 17.6% in the 'Access' group, and 11.6% in the 'Reserve' group. Prophylactic use accounted for 62.9% of all antibiotics prescribed. The study also noted a lack of compliance with prescribing guidelines and a scarcity of culture sensitivity testing. Conclusion: The study reveals a high prevalence of antibiotic use in tertiary care hospitals in Islamabad, with a significant reliance on 'Watch' and 'Reserve' group antibiotics. These findings highlight the critical need for the implementation of antimicrobial stewardship programs and national action plans to promote rational antibiotic use and combat AMR. Background: Antimicrobial resistance is one of the biggest global healthcare concerns as per the World Health Organization. It has impacted high, mid, and low-income countries with mid and low-income countries taking higher tools. Lack of data on the pattern of antibiotic use will lead to difficulty in the implementation of antimicrobial stewardship programs at the facility level. The purpose of this study is to determine the point prevalence of antibiotic use among hospitals in Islamabad and to determine the pattern of the WHO-aware group antibiotics in paediatrics. Methodology: The point prevalence survey methodology was used to collect random sample of 255 in two tertiary care hospitals in Islamabad in three months. All the inpatients admitted on the day of PPS were included in the survey. Data was collected through questionnaires from patients' files and analysed in SPSS Results: Total of two tertiary care hospitals with 375 beds were assessed in this study. Out of these, 255 patients 78.03% patients were receiving at least one antibiotic. Out of 255 antibiotics were used in which 32.1% were prescribed for medical prophylaxis, while 29.8% of the antibiotics prescribed were for surgical prophylaxis. Ceftriaxone and Maropenm accounted for 27% & 10.98% of total antibiotic prescribed respectively. The result also indicates high use of watch group antibiotics in children under 5 years of age. The majority of antibiotics were used as Empirical therapy. There was no specific institutional guideline for the use of antibiotics, while in 95% of cases there was no reason notes available for the use of antibiotics. Conclusion: We concluded that use of antibiotics in the two hospitals is very high. It has been also seen that there was no proper guideline for the use of antibiotics in hospitals with poor quality documentation. It is an immediate need for the implementation of a national action plan on the antimicrobials resistance and the development of an antibiotics stewardship program at each facility level to protect the resistance to the antibiotic.

Point-prevalence survey of antimicrobial use in intensive care units in Nepal.

This study aimed to investigate the prevalence and practices of antibiotic use in intensive care units (ICUs) in Nepal and to identify potential areas for implementing antimicrobial stewardship programs. A point prevalence survey was conducted to characterize and quantify the antimicrobial utilization in level III ICUs of Nepal. Data on antibiotic prescription rates, reasons for prescribing antibiotics, and prescribing practices were collected and analyzed. The prevalence of antimicrobial resistance was also assessed. The antibiotic prescribing rate was found to be very high, with 92.85% of patients in ICU on antibiotics. Prolonged surgical prophylaxis was the most common reason for prescribing antibiotics. Empirical therapy accounted for 67.5% of all antibiotic prescriptions. Prescribing practices were poor, with low adherence to guidelines and best practices. Broad-spectrum antibiotics were commonly used even for surgical prophylaxis or community-acquired infections. High resistance was observed against commonly used antibiotics. The study underscores the urgent need for effective antimicrobial stewardship programs in ICUs of Nepal. Implementing robust stewardship programs could help optimize antibiotic utilization, improve patient outcomes, and combat the global threat of antimicrobial resistance. The findings serve as a stepping stone toward understanding and improving antibiotic prescribing practices in ICUs of Nepal.

CAPTURA Regional Workshop Proceedings (28-30 June 2022, Virtual).

In response to the global threat of antimicrobial resistance (AMR), the Capturing Data on Antimicrobial Resistance Patterns and Trends in Use in Regions of Asia (CAPTURA) project worked with microbiology laboratories, pharmacies, and local governments in South Asia and Southeast Asia to expand the volume of historical and current data available on AMR and antimicrobial use and to identify gaps in data and areas for quality improvement. When the CAPTURA project completed its country-level engagement in the first half of 2022, the consortium brought together local, regional, and global AMR stakeholders for a virtual regional workshop to review data outputs from the project and share strategies to inform national and regional efforts to combat AMR. This paper summarizes the main topics presented in the workshop held from 28 to 30 June 2022. As such, it highlights lessons learned from the project and strategies to fight AMR. Although CAPTURA has been invaluable to countries and information from the project is already being used, barriers concerning data quality and sharing remain. Regional-level initiatives should continue to build on the momentum gained from the CAPTURA project in supporting national-level surveillance and data quality improvements to inform critical decisions around planning, policies, and clinical care. Project findings have highlighted that issues with antimicrobial resistance and use are wide ranging across countries. Going forward, building on the current foundations and tailoring approaches to meet local needs and capacities will be fundamental in combatting AMR.

Exploring Facilitators and Barriers to Delayed Antibiotic Prescribing in Rural Northwest China: A Qualitative Study Using the Theoretical Domains Framework and Behavior Change Wheel.

Antimicrobial resistance, exacerbated by antibiotic misuse, poses a global threat. Though delayed antibiotic prescribing (DAP) can mitigate antibiotic overuse, its adoption in developing nations, such as China, is limited. This study probed barriers and facilitators to DAP in Xinjiang, characterized by extensive rural landscapes and primary care institutions (PCIs). Adopting a qualitative methodology, we conducted key informant interviews with thirty participants across six county hospitals in Xinjiang using VooV Meeting. Employing a two-stage sampling method targeting economically diverse areas, our interviews spanned physicians, pharmacists, patients, and caregivers. We organized the data according to the Theoretical Domains Framework (TDF) and the Behavior Change Wheel (BCW), spotlighting behavioral and policy elements impacting DAP. Our research included thirty interviewees. Twelve physicians contemplated delayed prescriptions, while five adult patients and six caregivers encountered recommendations for delayed antibiotic prescriptions. Six patients sought pharmacists' advice on antibiotic necessity. Prominent TDF domains were memory, attention, and beliefs about consequences. Critical intervention functions included education and environmental restructuring, while vital policy categories encompassed communication/marketing and guidelines. Countering antibiotic misuse and resistance in China necessitates overcoming barriers through strategic resource distribution, comprehensive education, rigorous training, and consistent monitoring, thereby promoting DAP adoption. The adoption of DAP in rural healthcare settings in China has the potential to significantly reduce antibiotic misuse, thereby mitigating the global threat of antimicrobial resistance.

Storage of boar semen at 17°C without conventional antibiotics in an extender containing an organic bactericidal substance

IntroductionFacing the global threat of antimicrobial resistance, the reduction of antibiotic use in semen extenders is a main goal in artificial insemination (AI) of pigs. The aim of this study was to investigate the potential of a commercial extender containing an organic bactericidal supplement in the absence of conventional antibiotics to control bacterial growth and to maintain the quality of boar spermatozoa during long-term semen storage for up to 144 h at 17°C.MethodsSemen from 233 boars housed at 16 European AI centers was split and diluted in the long-term extender “Androstar Plus without antibiotics + organic bactericidal supplement” (APlus) and in the control extender Beltsville Thawing Solution (BTS) with gentamicin, which is routinely used in many AI centers. Sperm motility was assessed with computer-assisted semen analysis (CASA) and membrane integrity was evaluated with flow cytometry. The number of bacteria was determined by counting colonies on agar plates.ResultsAt the end of storage, bacterial counts were ≥ 106 CFU/mL in 10.7% of the APlus and in 0.4% of the BTS samples. At the same time, bacterial counts were only weakly correlated with sperm motility (r = −0.23, p < 0.05), and there was no correlation with sperm membrane integrity (p > 0.05). Among the 12 identified bacterial species in APlus samples, loss of sperm quality was exclusively observed in the presence of >106 CFU/mL Serratia marcescens and Klebsiella oxytoca. Both these bacterial species, despite their known multi-drug resistance and the continuous use of gentamicin in Europe, proved sensitive to this antibiotic, thus indicating an efficient quality assurance program and responsible antibiotic use.ConclusionLong-term storage of boar semen at 17°C without conventional antibiotics in an extender containing an organic bactericidal supplement is an option if semen samples are regularly tested for the presence of S. marcescens and K. oxytoca, and the source of contamination is eliminated.

Microbiological and hematological aspects of canine pyometra and associated risk factors

Canine Pyometra, also known as cystic endometrial hyperplasia complex, is a common reproductive issue in bitches. This study aimed to identify associated risk factors, hematological variation, bacteria involved, and the most potent anti-bacterial against bacterial isolates of canine pyometra. Forty-five bitches of different habitats, breeds, and ages infected with pyometra were included in the study. The samples were cultured to isolate bacteria associated with the pyometra and antibiotic sensitivity was done for each bacterial isolates to get antibiogram. The study findings showed that potential risk factors such as age group, medroxyprogesterone acetate administration, and changes in the white blood cells parameters were significantly associated (P < 0.05) with the type of pyometra. Closed cervix pyometra in dogs showed significantly higher prevalence of clinical signs including depression, vomiting, abdominal enlargement, and fever compared to the open cervix pyometra. Low levels of red blood cells, pack cell volume, and hemoglobin indicated that the pyometra-infected dogs were more likely to have normocytic, normochromic, and non-regenerative anemia. Pyometra was attributed to an increase in AST (Aspertate aminotransferase), ALT (Alanine transaminase), ALP (Alkaline phosphatase), BUN (Blood Urea Nitrogen), and Creatinine while a decrease in serum albumin. Of the all bacterial isolates, E. coli (35.55%) was the most common pathogen isolated from canine pyometra, followed by Pseudomonas spp. (26.66%). E coli and Pseudomonas spp. were susceptible to Imipenem, Amikacin, and Gentamicin while highly resistant to Ampicillin and Erythromycin. Imipenem, Amikacin, and Gentamicin were the most sensitive antibiotics, while Ampicillin and Erythromycin were the most resistant antibiotics for the bacterial strain isolated from canine pyometra. Multidrug resistant was observed in 26 of the isolated bacteria, indicating acquired resistance due to improper and uncontrolled use. Hence early diagnosis and close monitoring of antimicrobial susceptibility before therapeutic intervention is indispensable in preventing the global threat of antimicrobial resistance.

Genome Mining Uncovers NRPS and PKS Clusters in Rothia dentocariosa with Inhibitory Activity against Neisseria Species.

The growing global threat of antimicrobial resistance is reaching a crisis point as common bacterial infections, including those caused by pathogenic Neisseria species, are becoming increasingly untreatable. This is compelling the scientific community to search for new antimicrobial agents, taking advantage of computational mining and using whole genome sequences to discover natural products from the human microbiome with antibiotic effects. In this study, we investigated the crude extract from a Rothia dentocariosa strain with demonstrated antimicrobial activity against pathogenic Neisseria spp. by spot-on-lawn assay. The genomic DNA of the R. dentocariosa strain was sequenced, and bioinformatic evaluation was performed using antiSMASH and PRISM to search for biosynthetic gene clusters (BGCs). The crude extract with potential antimicrobial activity was run on Tricine-SDS-PAGE, and the putative peptides were characterised using liquid chromatography-tandem mass spectrometry (LC-MS). The crude extract inhibited the growth of the pathogenic Neisseria spp. Six BGCs were identified corresponding to non-ribosomal peptide synthases (NRPSs), polyketide synthases (PKSs), and ribosomally synthesised and post-translationally modified peptides. Three peptides were also identified corresponding to Actinorhodin polyketide putative beta-ketoacyl synthase 1. These findings serve as a useful reference to facilitate the research and development of NRPS and PKS as antimicrobial products against multidrug-resistant N. gonorrhoeae.

Antimicrobial peptidase lysostaphin at subinhibitory concentrations modulates staphylococcal adherence, biofilm formation, and toxin production

BackgroundThe ability of antimicrobial agents to affect microbial adherence to eukaryotic cell surfaces is a promising antivirulence strategy for combating the global threat of antimicrobial resistance. Inadequate use of antimicrobials has led to widespread instances of suboptimal antibiotic concentrations around infection sites. Therefore, we aimed to examine the varying effect of an antimicrobial peptidase lysostaphin (APLss) on staphylococcal adherence to host cells, biofilm biomass formation, and toxin production as a probable method for mitigating staphylococcal virulence.ResultsInitially, soluble expression in E. coli and subsequent purification by immobilized-Ni2+ affinity chromatography (IMAC) enabled us to successfully produce a large quantity of highly pure ~ 28-kDa His-tagged mature APLss. The purified protein exhibited potent inhibitory effects against both methicillin-sensitive and methicillin-resistant staphylococcal strains, with minimal inhibitory concentrations (MICs) ranging from 1 to 2 µg/mL, and ultrastructural analysis revealed that APLss-induced concentration-specific changes in the morphological architecture of staphylococcal surface membranes. Furthermore, spectrophotometric and fluorescence microscopy revealed that incubating staphylococcal strains with sub-MIC and MIC of APLss significantly inhibited staphylococcal adherence to human vaginal epithelial cells and biofilm biomass formation. Ultimately, transcriptional investigations revealed that APLss inhibited the expression of agrA (quorum sensing effector) and other virulence genes related to toxin synthesis.ConclusionsOverall, APLss dose-dependently inhibited adhesion to host cell surfaces and staphylococcal-associated virulence factors, warranting further investigation as a potential anti-staphylococcal agent with an antiadhesive mechanism of action using in vivo models of staphylococcal toxic shock syndrome.

Early-life antibiotic usage and impact on the gut microbiota, including emergence of antimicrobial resistant Enterococcus

The early-life microbiota is an ‘immature’ and highly dynamic microbial ecosystem, which is central to infant health. Both perinatal and postnatal factors can impact the gut microbiota, with antibiotics proposed to cause short and longer-term disturbances. Antibiotics not only impact microbial community composition but also contribute to the overall antibiotic resistance profile, i.e. the ‘resistome’, and they may also enhance carriage of multi-drug-resistant bacteria. Given high antibiotic prescription practices in pregnant women and newborns this also contributes to the global threat of antimicrobial resistance. This review summarises the current literature on antibiotic usage and how this may impact the developing gut microbiota during early-life, including the influence of horizontal gene transfer on contributions to pathogenicity and resistance of gut bacteria. We also focus on Enterococcus spp. given their high levels in infants and their link with opportunistic infections that are a significant cause of morbidity and mortality during early-life. Finally, a perspective on the importance to antibiotic stewardship, and harnessing the microbiota itself for anti-infection therapies for reducing antibiotic usage are also covered.

A geospatial approach to identify patterns of antibiotic susceptibility at a neighborhood level in Wisconsin, United States

The global threat of antimicrobial resistance (AMR) varies regionally. This study explores whether geospatial analysis and data visualization methods detect both clinically and statistically significant variations in antibiotic susceptibility rates at a neighborhood level. This observational multicenter geospatial study collected 10 years of patient-level antibiotic susceptibility data and patient addresses from three regionally distinct Wisconsin health systems (UW Health, Fort HealthCare, Marshfield Clinic Health System [MCHS]). We included the initial Escherichia coli isolate per patient per year per sample source with a patient address in Wisconsin (N = 100,176). Isolates from U.S. Census Block Groups with less than 30 isolates were excluded (n = 13,709), resulting in 86,467 E. coli isolates. The primary study outcomes were the results of Moran’s I spatial autocorrelation analyses to quantify antibiotic susceptibility as spatially dispersed, randomly distributed, or clustered by a range of − 1 to + 1, and the detection of statistically significant local hot (high susceptibility) and cold spots (low susceptibility) for variations in antibiotic susceptibility by U.S. Census Block Group. UW Health isolates collected represented greater isolate geographic density (n = 36,279 E. coli, 389 = blocks, 2009–2018), compared to Fort HealthCare (n = 5110 isolates, 48 = blocks, 2012–2018) and MCHS (45,078 isolates, 480 blocks, 2009–2018). Choropleth maps enabled a spatial AMR data visualization. A positive spatially-clustered pattern was identified from the UW Health data for ciprofloxacin (Moran’s I = 0.096, p = 0.005) and trimethoprim/sulfamethoxazole susceptibility (Moran’s I = 0.180, p < 0.001). Fort HealthCare and MCHS distributions were likely random. At the local level, we identified hot and cold spots at all three health systems (90%, 95%, and 99% CIs). AMR spatial clustering was observed in urban areas but not rural areas. Unique identification of AMR hot spots at the Block Group level provides a foundation for future analyses and hypotheses. Clinically meaningful differences in AMR could inform clinical decision support tools and warrants further investigation for informing therapy options.

Veterinary Students' Knowledge and Awareness of Antimicrobial Stewardship before and after Clinical Rotations.

Given the global threat of antimicrobial resistance, it is imperative that veterinary graduates are effective antimicrobial stewards. Veterinary students learn the principles of antimicrobial stewardship explicitly, through pre-clinical coursework, and implicitly, through the cases they each encounter on clinical rotations. We aimed to understand the influence of pre-clinical versus clinical learning on veterinary students' knowledge and awareness of antimicrobial concepts to guide efforts to improve instruction in these areas. To assess knowledge acquisition and to explore student perceptions of antimicrobial stewardship, a standardized online survey was administered to Cornell University veterinary students at two timepoints: in August 2020 before clinical rotations (N = 26 complete responses and N = 24 partial responses) and again in May 2021 after their clinical rotations (N = 17 complete responses and N = 6 partial responses). Overall and section-specific confidence and knowledge scores were calculated, using pairwise deletion for incomplete responses. Students generally had low confidence in antimicrobial topics and correctly answered only half of knowledge questions correctly; they performed the best on antimicrobial resistance knowledge questions. There were no significant differences in knowledge or confidence after clinical rotations. On average, students had only read one antimicrobial stewardship guideline. Students reported that human health care providers contributed more to antimicrobial resistance than veterinarians. In conclusion, graduating veterinary students at our institution have significant knowledge gaps in critical principles that are essential to become antimicrobial stewards. Explicit instruction in antimicrobial stewardship is necessary in the pre-clinical and clinical coursework, and the practical use of antimicrobial stewardship guidelines should be emphasized.

2 days versus 5 days of postoperative antibiotics for complex appendicitis: a pragmatic, open-label, multicentre, non-inferiority randomised trial

The appropriate duration of postoperative antibiotics for complex appendicitis is unclear. The increasing global threat of antimicrobial resistance warrants restrictive antibiotic use, which could also reduce side-effects, length of hospital stay, and costs. In this pragmatic, open-label, non-inferiority trial in 15 hospitals in the Netherlands, patients with complex appendicitis (aged ≥8 years) were randomly assigned (1:1) to receive 2 days or 5 days of intravenous antibiotics after appendicectomy. Randomisation was stratified by centre, and treating physicians and patients were not masked to treatment allocation. The primary endpoint was a composite endpoint of infectious complications and mortality within 90 days. The main outcome was the absolute risk difference (95% CI) in the primary endpoint, adjusted for age and severity of appendicitis, with a non-inferiority margin of 7·5%. Outcome assessment was based on electronic patient records and a telephone consultation 90 days after appendicectomy. Efficacy was analysed in the intention-to-treat and per-protocol populations. Safety outcomes were analysed in the intention-to-treat population. This trial was registered with the Netherlands Trial Register, NL5946. Between April 12, 2017, and June 3, 2021, 13 267 patients were screened and 1066 were randomly assigned, 533 to each group. 31 were excluded from intention-to-treat analysis of the 2-day group and 30 from the 5-day group owing to errors in recruitment or consent. Appendicectomy was done laparoscopically in 955 (95%) of 1005 patients. The telephone follow-up was completed in 664 (66%) of 1005 patients. The primary endpoint occurred in 51 (10%) of 502 patients analysed in the 2-day group and 41 (8%) of 503 patients analysed in the 5-day group (adjusted absolute risk difference 2·0%, 95% CI -1·6 to 5·6). Rates of complications and re-interventions were similar between trial groups. Fewer patients had adverse effects of antibiotics in the 2-day group (45 [9%] of 502 patients) than in the 5-day group (112 [22%] of 503 patients; odds ratio [OR] 0·344, 95% CI 0·237 to 0·498). Re-admission to hospital was more frequent in the 2-day group (58 [12%] of 502 patients) than in the 5-day group (29 [6%] of 503 patients; OR 2·135, 1·342 to 3·396). There were no treatment-related deaths. 2 days of postoperative intravenous antibiotics for complex appendicitis is non-inferior to 5 days in terms of infectious complications and mortality within 90 days, based on a non-inferiority margin of 7·5%. These findings apply to laparoscopic appendicectomy conducted in a well resourced health-care setting. Adopting this strategy will reduce adverse effects of antibiotics and length of hospital stay. The Netherlands Organization for Health Research and Development.