Antibiotics

The inappropriate use of antimicrobials enhances antimicrobial resistance (AMR). Antimicrobial stewardship (AMS) is a coordinated effort of prescribers, pharmacists, and nurses. Still, local data regarding AMS-related knowledge, attitudes, and practices (KAP) are scarce in many low and middle-income countries. We evaluated KAP regarding AMS among the healthcare providers at Komfo Anokye Teaching Hospital (KATH), Ghana, and found the related factors. A cross-sectional survey in the form of a descriptive survey was conducted among medical doctors, pharmacists, and nurses at KATH. Knowledge, attitude, and practice were evaluated using a structured questionnaire. The scores were converted into percentages and classified as good (>=60%) or poor (<60%). Chi-square tests were used to test associations, and logistic regression to predict good KAP (p<0.05). A total of 349 healthcare professionals participated, which comprised: 91 medical doctors (26.1%), 101 pharmacists (28.9%), and 157 nurses (45.0%). The majority of the respondents had formal AMS/AMR training (69.6%), and 37.0% had updated training the previous year. Only 18.6% demonstrated good AMS-related knowledge, although attitudes were largely positive (95.7% good) and reported practices were mostly appropriate (77.4% good). In multivariable models, greater years of practice (5-9 years: adjusted odds ratio [AOR] 2.32; >=15 years: AOR 2.77) and formal training (AOR 2.94) were associated with good knowledge. Formal training was also associated with good attitudes (AOR 5.19). Compared with medical doctors, nurses had lower odds of good practice (AOR 0.29), while pharmacists had higher odds (AOR 1.41). Participants with 10-14 years of experience had higher odds of good practice (AOR 3.18). This study revealed that marked knowledge deficits exist, despite favourable attitudes and generally good self-reported AMS practices. Role-tailored, competency-based AMS training with regular updates and reinforcement through practical stewardship tools is needed to translate positive attitudes into evidence-based prescribing and administration behaviours.

AimsPseudomonas aeruginosa biofilm-associated infections pose a significant clinical challenge due to their inherent antibiotic tolerance. This study aimed to evaluate the antibacterial and antibiofilm activity of Placentrex, a standardised aqueous placental extract, against P. aeruginosa and to elucidate its molecular mechanism of action using RNA sequencing (RNA-seq). Methods and ResultsPlacentrex exhibited potent bactericidal activity against P. aeruginosa at 50 mg/mL. Biofilm formation was significantly inhibited by [~]87% at 50mg/mL after 72 hours. Preformed biofilms were eradicated by [~]93% and [~]89% at 50 and 25 mg/mL, respectively. Interestingly, biofilm viability was reduced by [~]93% and [~]87% upon treatment with 50 mg/mL and 25 mg/mL of Placentrex, respectively. EPS characterisation revealed that the EPS contain a single large polysaccharide, and chromatography data suggested that it is made up of glucose as a monomer. RNA-seq identified coordinated downregulation of seven key genes, namely, flp major pilin (surface attachment), extracellular solute binding protein (ABC transporter-mediated nutrient sensing and biofilm maintenance), gntP permease (carbon metabolism), AraC family transcriptional regulator (quorum sensing and polysaccharide biosynthesis), ureE (urease nickel metallochaperone), aromatic amino acid permease (pyoverdine and PQS biosynthesis), and MFS transporter (efflux and autoinducer export). ConclusionsPlacentrex exerts comprehensive antibiofilm and antibacterial activity through simultaneous disruption of surface attachment, nutrient-sensing-driven biofilm maintenance, quorum sensing, carbon metabolism, urease virulence maturation, and efflux-mediated persistence. This polypharmacological mechanism supports Placentrex as a promising multi-target antibacterial agent against P. aeruginosa biofilm-associated infections. Impact statementPlacentrex is a potential anti-biofilm agent against Pseudomonas aeruginosa.

Background: Antimicrobial resistance is the world's silent pandemic. The public knowledge, attitudes, and practices (KAP) about antibiotic usage are strongly related to the growing problem in Nepal. Methods: A cross-sectional descriptive survey was done to 263 respondents. Information on KAP regarding antibiotics, primary healthcare sources, and demography was collected through a questionnaire. To identify health literacy gaps and characteristics that contribute to improper antibiotic use, this study assessed these variables across an age group from 18 to 60 years. Descriptive statistics analysis was performed to analyze the data. Results: The majority of respondents were between the ages of 18 and 39 (85.1%), female (63.1%), and had at least a bachelor's degree (67.8%). Significant misunderstandings about antibiotics remained, even though 77.6% of respondents correctly recognized antibiotics as effective against bacteria; 44.1% incorrectly believed that antibiotics cure viral diseases, and 87.8% felt that antibiotics should be stopped right away if adverse effects develop. In practice, 52.9% acknowledged quitting antibiotics as soon as symptoms improved, despite 89.4% consulting doctors. Additionally, 43% of respondents said they have taken antibiotics without a prescription, frequently due to pharmacist recommendations (21.67%) and financial or geographical constraints. The main sources of information were doctors (11.07%) and pharmacist-doctor combinations (14.88%), yet 81.8% of respondents said they had never heard of the phrase antimicrobial resistance. Conclusion: There is a significant lack between theoretical understanding and practical application, despite the high levels of fundamental knowledge toward the prohibition of non-prescription sales. Self-medication and early withdrawal are still common inappropriate practices. It is crucial to implement focused teaching initiatives that highlight the differences between bacterial and viral diseases as well as the risks associated with leftover medicine. It is advised to use digital platforms for younger demographics and to strengthen the role of pharmacists in order to reduce AMR.

Antimicrobial resistance is an impactful One Health issue. One of its drivers is the extensive use of antibiotics in both human and animal production systems, and despite regulatory restrictions on antibiotic use in poultry farming, antimicrobial resistance remains a major challenge. Consequently, animals are at higher risk of harder-to-treat diseases and play a role as resistance reservoirs, highlighting the need for alternative antimicrobial strategies. Towards this end, antimicrobial peptides (AMPs) have emerged as promising candidates due to their broad-spectrum activity and lower propensity to induce resistance. However, the effectiveness of AMPs against poultry pathogens, and in particular multi drug-resistant strains, is largely unclear. To tackle this question, we evaluated the synthetic AMP SET-M33 against four species of clinically relevant pathogens in poultry, namely Escherichia coli, Salmonella enterica, Enterococcus faecalis and Enterococcus cecorum. Using a panel of 141 field isolates, we found that SET-M33 broadly inhibited bacterial growth at low micromolar concentrations (median MICs of 2.5 M and 5 M for Gram-negative and Gram-positive strains, respectively), including in multi drug-resistant isolates. To examine the potential impact of SET-M33 on the host, we established a new in vitro co-cultivation system using chicken intestinal organoids. We found that SET-M33 retains its antimicrobial activity in organoid-microbe co-cultures at concentrations that preserved host viability. These findings demonstrate the potential of SET-M33 as a new antimicrobial agent against pathogens in poultry.

BackgroundThe global rise of multidrug-resistant (MDR) bacteria represents a critical public health threat, and Romania ranks amongst the most affected countries in Europe. As conventional therapy increasingly fails, bacteriophage therapy has re-emerged as a promising alternative to antibiotics. Urban rivers, contaminated with resistant bacterial strains, represent an underexplored and accessible reservoir for the isolation of lytic phages with therapeutic potential. MethodsTwo bacteriophages, 17M_Ec17_D and 22C_Ec22_D, were isolated from the Dambovita River, Bucharest, Romania, using MDR E. coli as host bacteria. Phage characterization included plaque morphology, transmission electron microscopy, and host range assessment by spot assay against 30 MDR E. coli isolates. Whole genome sequencing was performed on Illumina MiSeq and Oxford Nanopore Technologies MinION platforms, followed by bioinformatic analysis including taxonomic classification, lifestyle prediction, and functional annotation. ResultsBoth phages formed clear plaques and were classified as Kayfunavirus (17M_Ec17_D, Podoviridae-like) and Kagunavirus (22C_Ec22_D, Siphoviridae-like) with nucleotide similarities of 89.2% and 71.4% to their closest relatives, respectively, suggesting both are candidates for novel species. Host range analysis revealed lytic activity against 13% and 10% of tested MDR isolates, with complementary infection profiles. Genomic analysis confirmed a strictly lytic lifestyle for both phages, supported by the presence of holin and spanin genes and the absence of lysogenic modules, antibiotic resistance genes, and virulence factors. ConclusionsTo the best of our knowledge, this is the first study conducted in Romania to isolate and genomically characterize lytic bacteriophages targeting MDR E. coli. The characterized phages represent safe therapeutic candidates whose complementary host ranges suggest potential application as part of phage cocktail to broaden antimicrobial coverage against MDR infections.

Urinary tract infections (UTIs) are the most prevalent bacterial infections globally, and their management increasingly challenged by antimicrobial resistance (AMR). Probiotics offer a promising approach to mitigate AMR by competitively excluding uropathogens and enhancing host immunity by producing immune modulators. Despite being potential, key gaps persist between the discovery of uroprotective probiotic strains and optimization of formulations for urinary tract delivery. Here, we analyzed the urinary microbiome of UTI patients and healthy individuals to identify potential probiotic candidates for the prevention and management of UTIs. Publicly available 16S rRNA amplicon sequencing data of the urinary tract were processed using a standardized pipeline for sequence quality assessment, taxonomic assignment, and microbial function prediction. Comparative analysis showed a significant shift in microbial composition between UTI patients and healthy controls. The dominated phyla identified included Acidobacteriota, Actinobacteriota, Bacteroidota, Campylobacterota, Cyanobacteria, Firmicutes, Fusobacteriota, Patescibacteria, Proteobacteria, and Synergistota. Overall differential abundance analysis revealed Escherichia coli as the predominant UTI-associated species, while Lactobacillus crispatus was enriched in healthy samples. Additionally, predictive functional analysis indicated that metabolic pathways associated with beneficial microbes were enriched in the healthy group. Overall, the study highlights the association of distinct urinary microbiome signatures with infection status, which supports L. crispatus as the most promising probiotic for UTI prevention and control.

Biofilms pose a significant challenge to antimicrobial therapy. Bacteria in biofilms differ from planktonic counterpart in their altered metabolism, collective behavior, protective role of extracellular matrix and diversified microbial subpopulations. These attributions significantly influence bioavailability and activity of antibiotics. The presence of bacterial aggregates during acute infections expands the problem to many other conditions previously not discussed in the biofilm context. Klebsiella pneumoniae is a leading cause of life-threatening hospital-acquired infections and is included in the WHO Bacterial Priority Pathogens List due to increasing antimicrobial resistance. The combination of antimicrobial resistance and the ability to form biofilms severely limits the efficacy of antibiotic treatments. In this study, we investigated the in vitro susceptibility of mature biofilms to 13 antimicrobials of K. pneumoniae clinical isolates from a single hospital. The resistance profiles of the local clinical isolates were consistent with the global epidemiology of K. pneumoniae. Minimal biofilm eradication concentrations (MBEC) for mature biofilms were defined with two assays (biomass and metabolic activity measurements) and brought into relation with susceptibility breakpoints and plasma (Cmax). Colistin sulfate, tigecycline, cephalosporins and combination of imipenem with cilastatin were the most potent biomass eradicators, while suppression of metabolic activity was barely reachable. Moreover, we observed a notable increase in metabolic activity upon exposure to sub-MBEC concentrations of antibiotics. Finally, our data broach a subject of antibiotic prioritization with respect to biofilm tolerance. IMPORTANCEThis study addresses the critical gap between standard antibiotic susceptibility testing and the tolerance of biofilm and microbial aggregates during infections caused by K. pneumoniae. By systematically evaluating mature biofilms from a significant number of clinical isolates, we demonstrate that colistin and tigecycline show potent activity against both biofilm biomass and metabolic activity, whereas cephalosporins primarily reduce biomass without effectively suppressing bacterial metabolism, and other drugs have only weak effects on biofilms at clinically achievable concentrations. Furthermore, the alarming observation that sub-inhibitory biofilm eradication concentration (sub-MBEC) of antibiotic can paradoxically increase the metabolic activity of biofilms highlights a potential risk factor for therapy failure and resistance development. Our findings contribute to the necessary evidence base for prioritizing existing antibiotics in the limited armamentarium against biofilm-forming K. pneumoniae.

BackgroundTransfer of Streptococcus agalactiae, or Group B Streptococcus (GBS) from parent to newborn during delivery can produce life-threatening infections in neonates. Probiotics could potentially prevent GBS colonization in pregnant individuals. We conducted a systematic review and meta-analysis to evaluate the effectiveness of probiotic administration in treating Group B Streptococcus colonization. MethodsMEDLINE, ClinicalTrials.gov, PROSPERO, and the Cochrane, Wild Card, Central Register of Controlled Trials were searched from the July 2015 of each database until July 2025 that completed a randomized controlled trial which compared Probiotic versus control. We utilized the Cochrane Risk of Bias 2.0 (RoB 2) tool to assess bias in the systematic review. Results14 randomized controlled clinical trials met our inclusion criteria. The trials used oral probiotic administration compared to either a placebo or a control group. A meta-analysis showed that probiotic administration produced a statistically significant decrease in the rate of GBS colonization in pregnant individuals. The individual studies ranged from four showing great effectiveness, while the other 10 studies showed a range of effectiveness, from partially effective to no effectiveness in preventing GBS colonization. ConclusionOverall, probiotics were effective in lowering infection rates of GBS, but individual studies showed great variability. Probiotics show promise in decreasing GBS colonization in pregnant people, but more studies need to be performed in order to use them effectively and decrease antibiotic usage.

The gut microbiome plays a central role in host metabolism, immune function, and overall health, with disruptions in microbial composition (dysbiosis) being associated with a range of metabolic, inflammatory, and infectious conditions [1,2]. Consequently, strategies aiming to modulate the microbiome require selective activity that preserves beneficial commensals while limiting pathogenic organisms [3]. In this context, ThymoQuin(R)--a cold-pressed, standardized black cumin (Nigella sativa) seed oil developed by TriNutra Ltd. and defined by [&ge;]3% thymoquinone (TQ), controlled p-cymene levels, and low free fatty acids ([&le;]1.25%)--was evaluated for its microbiome-relevant activity. In vitro minimum bactericidal concentration (MBC) assays across three independent batches demonstrated a biphasic, dose-dependent response. At intermediate concentrations (0.25-0.5%), Streptococcus thermophilus was strongly stimulated (up to 53-fold) and Lactiplantibacillus plantarum fully preserved, while Klebsiella pneumoniae was effectively reduced (>94%). Akkermansia muciniphila exhibited stable viability at concentrations below 1%, with reductions only observed at 1%. This is notable given its role as a mucin-degrading commensal that has been linked to metabolic health, but whose abundance may vary across physiological and disease contexts [4,5]. At concentrations [&ge;]1%, selective effects diminished, resulting in broader antimicrobial activity and reduced specificity. These findings indicate a defined concentration range in which selective microbiome modulation is maintained, whereas higher thymoquinone levels may increase the risk of non-selective detrimental effect on microbes.

Abstract Background: The sanitation crisis poses a significant public health risk, leading to diseases like diarrhea, cholera, and typhoid, which impede children's health and development in developing countries like Uganda. Improving sanitation infrastructure is crucial for safeguarding child health and future generations. However, the link between sanitation and children's health is complex, influenced by various factors. This investigation in Gulu scrutinizes the correlation between sanitation practices and child well-being, considering moderating factors such as age, climate, and consistent water accessibility. Methods: The study used a convergent parallel design with equal priority. The Social Ecological Model, Social Learning Theory, and Diffusion of Innovations Model guided it. Researchers collected data from 10 health facilities and 317 households, using purposive and simple random sampling. They used sampling proportions proportional to village size within strata. The researcher analyzed quantitative data using SPSS with factor analysis, structural equation modeling, and multivariate analysis. To analyze qualitative data, they used DQA Minor Lite software, which facilitated thematic analysis. Results: The finding shows 56.8% of households had low socio-economic status. Sanitation was poor; 24.9% household had improved latrines, 20.5% had handwashing facilities with soap, and 68.1% used basic anal cleansing. For nutrition, 38.5% of children were malnourished by MUAC; by Z-scores, 28.7% were stunted, 16.4% underweight, 13.6% wasted. Diarrhea affected 62% of children. Climate worsened sanitation: 48.3% had latrines collapse from floods, and 63.4% of waterborne diseases occurred in both dry and wet seasons. Moderation analysis on childhood diarrhea shows that sociocultural factors ({beta} = -0.20, p < 0.001), sanitation ({beta} = -0.15, p < 0.001), and health system response ({beta} = -0.18, p < 0.001) reduced diarrhea. Climate change increased risk ({beta} = 0.15, p < 0.001) and moderated sanitation effects ({beta} = 0.01, p < 0.05). Models explained 10-14% variance. Age and water access had no moderating effect. While childhood malnutrition shows that sociocultural factors ({beta} = -0.43, p < 0.001) and health system response ({beta} = -0.13, p < 0.001) reduced malnutrition. Sanitation had no effect ({beta} = 0.01, p > 0.05). Age increased malnutrition risk ({beta} = 0.28, p < 0.01) and moderated sociocultural effects ({beta} = 0.16, p < 0.001), but not sanitation. The model explained 21% variance, R{superscript 2} = 0.21, p < 0.001. Conclusion: Sociocultural improvements and health system responses lower both diarrhea and malnutrition. Climate worsens diarrhea and alters sanitation's impact. Age worsens malnutrition and changes sociocultural effects. These findings are valuable for policymakers, healthcare professionals, and researchers

Background Antimicrobial stewardship (AMS) and infection prevention and control (IPC) are complementary strategies to improve patient safety and address antimicrobial resistance (AMR). In low- and middle-income countries (LMICs), they are often implemented separately, reducing effectiveness. Evidence on integrating AMS and IPC in routine hospital practice remains limited. Objective To evaluate the feasibility of an integrated AMS-IPC improvement approach and describe changes in implementation in Vietnamese hospitals. Methods We conducted a multisite quality improvement initiative in four hospitals within the national AMR surveillance network in Viet Nam (March-September 2025). We used US-CDC tools to guide the implementation, including the Global Antibiotic Stewardship Evaluation Tool (G-ASET) and the Infection Control Assessment and Response (ICAR) tool. Baseline assessments were followed by feedback, multidisciplinary action planning, and targeted capacity building. Follow-up occurred 2-5 months later. Changes were analysed descriptively using quantitative scores and qualitative synthesis, and reported following the SQUIRE 2.0 guidelines. Results All hospitals had established IPC programmes at baseline, while AMS maturity varied. G-ASET scores improved across all sites, with greater gains in hospitals starting from lower baselines. Key improvements included leadership and governance, education and training, stewardship actions, and monitoring and reporting. IPC practices aligned with AMS priorities also improved, particularly transmission-based precautions, environmental cleaning, and cross-team coordination. Infrastructure-dependent areas, such as water safety, showed limited short-term progress. Conclusions An integrated AMS-IPC approach using repeated assessment and feedback is feasible and associated with meaningful improvements. This model offers a scalable strategy for strengthening hospital responses to AMR in LMICs and informs national programmes.

Background The use of oral retinoids and valproate during pregnancy can cause birth defects. In 2018, the EMA revised Pregnancy Prevention Programs (PPPs) for these medications. Pharmacy technicians in Denmark dispense prescription medications and must counsel customers. Aims This study aimed to examine knowledge of the teratogenicity of oral retinoids and valproate and use of the relevant PPPs among pharmacy technicians in Denmark. Methods A cross-sectional survey was conducted in spring 2025 using questionnaires developed for and tested in an international project. Data was collected via relevant Facebook groups and email invitations. Descriptive statistics were used for analyses. Results For oral retinoids, 80 respondents were analyzed; 95% were women, 86% were pharmacy technicians, the mean age was 37.2 years. Most dispensed oral retinoids several times per month. Two respondents did not know retinoids were teratogenic. The most used PPP measure was the outer packaging warning (54%). Informing women about teratogenic effects was the most common practice. For valproate, 41 respondents were analyzed. Their characteristics were similar to those of respondents in the oral retinoid survey. Most dispensed valproate once per month. One-third did not know valproate was teratogenic. The outer packaging warning was used by 19%. The most common practice was referring to the prescribing physician if pregnancy was suspected. Conclusion Danish pharmacy technicians knowledge about teratogenic drugs and the PPP was poorer than that of pharmacists, especially regarding valproate, and requires attention in educational programs. The feasibility of PPP measures for both oral retinoids and valproate should be optimized.

The search for antimicrobials with a low propensity to select resistance has intensified in response to the global antimicrobial resistance crisis. Norway spruce resin (Picea abies) has long been used in Northern European wound care traditions and has shown broad antimicrobial activity in earlier microbiological studies. In the present study, we evaluated whether prolonged exposure to medical-grade spruce resin promotes reduced susceptibility in clinically relevant bacterial species. A 20-day serial-passage experiment was performed with Staphylococcus aureus, Pseudomonas aeruginosa, and Enterococcus faecalis using sub-inhibitory resin concentrations and broth microdilution readouts at baseline, day 10, and day 20. Resistance development was predefined as a [&ge;]4-fold increase in inhibitory concentration. Baseline inhibitory concentrations were 1.25% for S. aureus, 5.0% for P. aeruginosa, and 2.5% for E. faecalis. After 20 days, inhibitory concentrations were 2.5%, 10.0%, and 2.5%, respectively, corresponding to at most 2-fold changes and remaining below the predefined threshold for resistance development. Validation and vehicle-control arms indicated that these shifts were not attributable to medium transfer or solvent-related bias. These findings suggest that medical-grade Norway spruce resin has a low short-term tendency to select for reduced susceptibility under serial-passage conditions. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=134 SRC="FIGDIR/small/723837v1_ufig1.gif" ALT="Figure 1"> View larger version (34K): org.highwire.dtl.DTLVardef@160479forg.highwire.dtl.DTLVardef@1fe1e95org.highwire.dtl.DTLVardef@89dec3org.highwire.dtl.DTLVardef@17ff134_HPS_FORMAT_FIGEXP M_FIG C_FIG

Pseudomonas aeruginosa, a Gram-negative opportunistic pathogen is well known for life-threatening acute infections among the human population. The bacterium can withstand most antibiotics by using their high levels of inherent and acquired resistance mechanisms such as Biofilm-EPS, Persistence, and Quorum sensing (QS). Owing to the importance of adaptive antibiotic multi-drug resistance of P. aeruginosa, the current investigation is aimed to explore the phytochemicals derived from mangrove plants as potential agents to control biofilm and drug resistance mechanisms through a multi-mechanistic computational approach. For identifying potential compounds and target, In-silico drug repurposing technique is implemented by docking/virtual screening of 49 phytochemical compounds against 18 proteins involved in the Persister Cell formation, QS, and EPS synthesis in P. aeruginosa which resulted the proteins RelA and SpoT (persistence), PqsA, and PqSR (QS), and PelA and PelB (EPS synthesis) and compounds Taraxerone and Taraxerol to be potential. The results of docking were well corroborated with MD simulations. These targets and compounds explored through in-silico approach, are found to target potential antimicrobial pathways involving EPS synthesis, persistence genes, and QS, aiming to enhance antibiotic efficacy. Further, this study could be reference for in-vivo and in-vitro investigations to evaluate the further effectiveness of the compounds and potentiality of the proteins for MDR therapeutics of P. aeruginosa.

Molecular diagnostics to detect Vibrio cholerae (Vc) may be negatively impacted by pathogen-specific lytic bacteriophage (phage) predation. To address this problem, phage detection as a proxy for pathogen detection has been proposed. However, efforts to modernize cholera diagnostics with molecular tools require addressing knowledge gaps on best practices to detect Vc and associated bacteriophages. We conducted polymerase chain reaction (PCR), quantitative PCR (qPCR), and nano-liter (nl) qPCR targeting Vc and known phages (ICP1/2/3) on stool samples collected from patients admitted at hospitals across Bangladesh. Of 4,975 patients enrolled, 2,574 diarrheal samples were collected and over 65,000 reactions were conducted, including replicates. We analyzed the results for target-specific assay alignment and then used machine learning to determine the effect of phage predation on Vc-assay alignment. Standard curve analyses were used to set qPCR-positivity thresholds at 7.3x105 CFU/mL for Vc and 1.7x103, 9.3x103, and 3.0x105 PFU/mL for ICP1, ICP2, and ICP3, respectively. Among 2,462 samples assayed by qPCR, target detection was 25.3% (623), 7.8% (193), 0.5% (13), and 5.8% (144) for Vc, ICP1, ICP2, and ICP3, respectively. There was strong alignment between assays for Vc detection ({kappa}=0.785) and moderate alignment for phage detection ({kappa}=0.609, 0.593, and 0.533 for ICP1/2/3, respectively). Phages were ranked as the first (ICP1) and third (ICP3) effectors of Vc diagnostic alignment. These findings provide insights on how to prioritize molecular methods in the cholera field as well as related less tractable diseases facing similar diagnostic challenges. IMPORTANCEThis paper presents a comprehensive comparison of molecular methods to detect Vibrio cholerae (Vc) and associated bacteriophage (phage) which can be used as a proxy for pathogen detection. This initiative is an important step towards modernizing cholera diagnostics with molecular tools. In this study, we found that quantitative polymerase chain reaction (qPCR) represents a reasonable approach to detect Vc and associated phages balancing assay performance, cost, and accessibility. A key additional finding was that phage predation was found to be a leading factor that impacts the alignment of molecular methods to detect Vc. While we recommend qPCR be added to the cholera diagnostic toolkit, the effects of phage predation need to be accounted for in the development and evaluation of cholera diagnostics. These findings have applicability to less tractable disease where diagnostics share similar vulnerabilities.

Colibacillosis, caused by Avian Pathogenic Escherichia coli (APEC), result in substantial economic losses in global poultry production. The emergence of multidrug-resistant (MDR) APEC poses zoonotic risks through horizontal transfer of antimicrobial resistance (AMR) genes. Bacteriophage therapy emerges as a safe alternative to antibiotherapy; however, comprehensive characterization of phages targeting MDR-APEC from diverse geographical regions remains limited. We isolated five lytic bacteriophages from poultry fecal samples collected from five Indian states and characterized them through morphological analysis, physiological stability testing, whole-genome sequencing, and in vivo efficacy assessment. Host range was determined against APEC isolates, and therapeutic potential was validated in Galleria mellonella infection model. All five phages showed Myovirus-like morphology and stability across physiologically relevant temperatures (up to 55-70{degrees}C) and pH conditions (3-11). Their genome size ranges from 170 to 356 kb, belonging to three distinct genera; Dhakavirus, Gaprivervirus, and Asteriusvirus. Genomic analysis confirmed absence of antimicrobial resistance, virulence, toxin, or lysogeny genes. 51 APEC strains were isolated, of which 23 (45.1%) were MDR. Individual phages lysed 37-51% of tested APEC and 17-39% of MDR strains. Three Escherichia phages (fBSZT1, fUAMT1, fPKPT2) significantly improved larval survival to 60-80% at MOI 10 in G. mellonella infection models compared to untreated controls. This study establishes a well-characterized phage bank targeting MDR-APEC strains, providing foundation for developing phage-based interventions to reduce antibiotic dependency and mitigate AMR transmission risks under One Health framework.

Pseudomonas aeruginosa is a clinically significant bacterial pathogen that poses a serious threat to aquaculture. However, there are limited information on Massilia isolates against pathogenic P. aeruginosa in aquaculture. In the present study, a facultative predator, M. varians isolate P2-4, was isolated from aquaculture sediment using Chinese mitten crab Eriocheir sinensis-pathogenic P. aeruginosa as the prey bacterium, and its genomic feature, bacteriolysis-related genes, safety, bacteriolytic spectrum, and in vitro and in vivo antibacterial effects against pathogenic P. aeruginosa in E. sinensis were further characterized. Isolate P2-4 consisted of one chromosome and one plasmid (with a total of 75 tRNAs, 7 5S rRNAs, 7 16S rRNAs, 7 23S rRNAs, 34 sRNAs, 5,238 coding genes, 20 genomic islands, 1 prophage, 23 insertion sequences, and 102 repeat sequences), and harbored 19 bacteriolysis-related genes (pilA, pilB, pilC, pilD, pilF, pilG, pilH, pilM, pilO, pilP, pilQ, pilS, pilR, pilT, mltA, mltB, mltC, mltD, and dacB) associated with cellular motility and cell wall lysis. In addition, the isolate carried no virulence genes, was unable to produce haemolysin, hydrogen sulfide, nitrite and ammonia, and avirulent in E. sinensis with a 7-day acute intraperitoneal LD50 value of above 5.0 x 108 CFU/mL. Furthermore, the isolate possessed a wide bacteriolytic spectrum against pathogenic Shewanella algae, Aeromonas caviae, A. hydrophila, and Photobacterium damselae besides P. aeruginosa, exhibited bacteriolysis rates of 99.35% to 99.99% towards the pathogenic P. aeruginosa at 1.0x103 to 1.0x10{square} CFU/mL, and displayed relative percentage survivals of 42.31% to 73.08% against P. aeruginosa infection in E. sinensis at doses of 6.0 x 103 to 6.0 x 105 CFU/g diet. To our knowledge, this study for the first time demonstrates a M. varians strain as a potential biocontrol agent against pathogenic P. aeruginosa in aquaculture.

Cryptosporidium parvum is a protozoan parasite responsible for cryptosporidiosis, significantly threatening immunocompromised individuals, particularly HIV/AIDS patients, by causing severe diarrhea and potential mortality. Current treatments are largely ineffective, prompting investigations into new therapeutic options. This study evaluated two antiparasitic drugs: Mebendazole, used for helminth infections, and Artemisinin, used for malaria. The SKSR gene family encodes virulence factors in C. parvum, and Calcium-dependent protein kinase1 (CpCDPK1) regulates the life cycle of C. parvum; targeting these proteins may reduce growth and infection in hosts. In the current study, molecular docking was conducted taking Mebendazole and Artemisinin drugs as ligands, SKSR gene family and CpCDPK1 proteins as drug targets. Results with SKSR showed binding energy of -4.9 kcal/mol, -6.72 kcal/mol for Mebendazole and Artemisinin, respectively. Whereas, with CpCDPK1, the binding energies were -6.44 kcal/mol, -9.18 kcal/mol for Mebendazole and Artemisinin, respectively. Docking of Nitazoxanide (an in-use drug for C. parvum) with SKSR and CpCDPK1 revealed binding energies -4.2 kcal/mol, -4.81 kcal/mol, respectively. The stability of the proteins (targets) upon binding to the ligands was assessed by performing all-atom MD simulations for 100ns using the GROMACS package. No major variations were observed upon binding of Artemisinin and Mebendazole to SKSR and CpCDPK1. The findings of MD simulations imply that both proteins maintain their stability upon binding of Artemisinin and Mebendazole. Molecular Docking and MD simulation studies suggest that Artemisinin and Mebendazole are potential candidates for repurposing in the treatment of C. parvum infections, with recommendations for in vitro studies to validate these findings.

BackgroundRising antimicrobial resistance rates, require new therapeutic approaches such as antimicrobial peptides (AMPs), which are part of the innate immune defense, as alternatives to antibiotics. In this study, we aim to unravel the antibacterial activity of human histone H1.2 peptide against Pseudomonas aeruginosa and its potential immune modulatory role. MethodsWe used a hemofiltrate peptide database for antimicrobial peptide prediction to identify novel human AMPs. Thirteen sequences of histone H1 were identified as putative AMPs, synthesized, and tested against bacterial ESKAPE pathogens in a radial diffusion assay. SYTOX green assay, electrophoretic mobility shift assay, and differential proteomics assays were conducted to determine the mode of action of H1.2 peptide fragment. A crystal violet assay was performed to evaluate the inhibition of biofilm formation. The cytotoxicity of the peptide was tested in LDH and Alamar assays. Finally, to visualize the contributions of H1.2 in NETs formation, scanning electron microscopy was performed. ResultsThe H1.2 peptide inhibited the growth of P. aeruginosa in a dose and pH-dependent manner without cytotoxicity towards mammalian THP-1 cells. It acts on intracellular targets to inhibit the growth of P. aeruginosa. STRING analysis from the differential proteomics assay showed that H1.2 targets the downregulation of proteins involved in the biogenesis of outer membrane proteins, including the folding and trafficking of outer membrane proteins across the cytoplasmic membrane. Scanning electron microscopy images showed that H1.2 forms NET-like structures capable of trapping and immobilizing P. aeruginosa. ConclusionThe characterized antimicrobial activity of H1.2 points to a role for human histone H1 fragments in innate immunity and may represent a promising approach for the development of novel antibacterial therapies. Graphical Summary O_FIG O_LINKSMALLFIG WIDTH=192 HEIGHT=200 SRC="FIGDIR/small/724237v1_ufig1.gif" ALT="Figure 1"> View larger version (36K): org.highwire.dtl.DTLVardef@1778ddborg.highwire.dtl.DTLVardef@26430org.highwire.dtl.DTLVardef@ffbfa2org.highwire.dtl.DTLVardef@7e38ae_HPS_FORMAT_FIGEXP M_FIG C_FIG Sec transport and BAM complex system including chaperone proteins and quality control proteases are inhibited by H1.2 in Pseudomonas aeruginosa.Outer membrane proteins (OMPs) are synthesized in the cytoplasm and transported across the inner membrane via the Sec translocase, assisted by SecA/SecB or ribosomes. In the periplasm, they are escorted by chaperones such as SurA to the BAM complex for insertion into the outer membrane. Here, we show that H1.2, an antimicrobial peptide, targets membrane biogenesis in P. aeruginosa through downregulating Sec translocase (SecA/SecB and SecYEG), SurA, and BAM complex. Therefore, leading to improper transfer, folding and insertion of OMPs into the outer membrane. Normally, misfolded proteins are degraded by the protease MucD to prevent toxic aggregation in the bacteria. However, with H1.2 inhibiting MucD the proteotoxic stress is exacerbated, ultimately compromising bacterial homeostasis and viability. Figure created using BioRender.com.

Acinetobacter baumannii is a leading multidrug-resistant critical priority pathogen in healthcare settings, where biofilm formation confers survival and antibiotic tolerance. Targeting virulence associated proteins offers an alternative to conventional bactericidal strategies. Here, the inner membrane anchored lipoprotein NLPA, implicated in biofilm associated adaptation, was studied as a putative anti-virulence target using an integrated in silico pipeline and complementing the computational findings. The Alpha fold-derived structure of NLPA served as the basis for virtual screening of approximately 1.6 million compounds, with subsequent prioritization guided by MM/GBSA calculated binding free energies to highlight the top promising candidates. Molecular dynamics simulations demonstrated stable NLPA ligand complexes, as indicated by equilibrated RMSD, low residue fluctuations in the binding region, and persistent interaction networks over time. Pharmacokinetic evaluation indicated that the compounds satisfied Lipinskis Rule of Five and had overall acceptable ADMET characteristics. Two compounds, NLPA-6 and NLPA-3, showed the most favourable predicted binding free energies, suggesting strong and stable interactions within the NLPA binding site. NLPA-3 was evaluated in vitro against A. baumannii to validate the computational outcomes. The compound displayed moderate antibacterial activity with a MIC of 125 g/mL and demonstrated 55.75% inhibition of biofilm formation at 4x MIC. In addition, in macrophage infection studies, NLPA-3 decreased intracellular bacterial survival to 19.25% at 50 g/mL, suggesting that it may disrupt virulence pathways linked to persistence. In whole, these findings identify promising NLPA targeting compounds and support the feasibility of NLPA as an anti-virulence target.