Antimicrobial Profiles Research Articles

BACTERIOLOGICAL PROFILE OF SURGICAL SITE INFECTIONS AND THEIR ANTIBIOGRAM: A STUDY IN A TERTIARY CARE HOSPITAL

Objective: To ascertain the frequency of surgical site infection (SSI) occurrences and the prevalence of aerobic bacterial infections associated with their antibiogram. Methods: For 1 year, a tertiary care hospital affiliated with Government Medical College, Amritsar, served as the site of this cross-sectional study. Pus aspirates were aseptically taken from 86 consecutive individuals suspected of having SSI using a sterile surgical syringe with a needle and sterile cotton surgical swabs. The specimens were cultivated and placed in an incubator at 37°C for 24 h. The individual strains were then identified using traditional techniques. The Kirby–Bauer’s Disc Diffusion Method was employed to conduct antimicrobial susceptibility testing. Results: Among 1021 patients, 86 were clinically suspected of SSI, and 64 were culture-positive. The incidence of SSI was 8.42%. The most common organisms were Klebsiella pneumoniae 34% (17/50) and Escherichia coli 32% (16/50), whereas Staphylococcus aureus 100% (14/14) was the only organism found among Gram-positive cocci. The antimicrobial Profile of Gram-positive isolates showed maximum sensitivity to linezolid (100%), followed by erythromycin (85.7%). The antimicrobial profile of lactose fermenters revealed maximum sensitivity to polymyxin (100%). Antibiogram of Proteus species showed maximum sensitivity to meropenem (100%) and ceftazidime tazobactam (100%). Non-fermenters showed 100% polymyxin and 80% sensitivity to aztreonam. Conclusion: Our study has revealed significant findings. The incidence of SSI was found to vary between 8% and 12% in our tertiary care center. K. pneumoniae 26.5% (17/64) and E. coli 25% (16/64) were the most common organisms isolated. S. aureus 21.2% (14/64) was the only organism found among Gram-positive cocci. SSI below waist surgery was far more 75% (48/64) than above waist surgery of 25% (16/64).

The gut microbiome and resistome of yellow perch (Perca flavescens) living in Minnesota lakes under varying anthropogenic pressure

Anthropogenic activities can significantly impact wildlife in natural water bodies, affecting not only the host's physiology but also its microbiome. This study aimed to analyze the gut microbiome and antimicrobial resistance gene profile (i.e., the resistome) of yellow perch living in lakes subjected to different levels of anthropogenic pressure: wastewater effluent-impacted lakes and undeveloped lakes. Total DNA and RNA from gut content samples were extracted and sequenced for analysis. Results indicate that the gut resistome and microbiome of yellow perch differ between lakes, perhaps due to varying anthropogenic pressure. The resistome was predominated by macrolide resistance genes, particularly the MLS23S group, making up 53 % of resistome sequences from effluent-impacted lakes and 73 % from undeveloped lakes. The colistin resistance gene group (mcr) was detected in numerous samples, including variants associated with Aeromonas and the family Enterobacteriaceae. The gut microbiome across all samples was dominated by the phyla Proteobacteria, Firmicutes, and Actinobacteria, with the opportunistic pathogens Plesiomonas shigelloides and Aeromonas veronii more abundant in effluent-impacted lakes. Metagenomic analysis of wild fish samples offers valuable insights into the effects of anthropogenic pressures on microbial communities, including antimicrobial resistance genes, in water bodies.

Peritonitis-related bacterial infections: a large-scale case-series retrospective study in 160 domestic animals (2009-2022).

Bacterial peritonitis infections comprise a life-threatening clinical condition in domestic animals that commonly lead to sepsis and high mortality. A set of bacterial pathogens have been identified in septic peritonitis in livestock and companion animals. Nonetheless, most descriptions are restricted to case reports or limited to only one domestic species, and a restrict number of comprehensive studies involving this infection has focused on a great number of domestic animals. Here, we retrospectively investigated selected epidemiological data (with an emphasis in outcome), clinical signs, bacteriological culturing, and in vitro antimicrobial susceptibility patterns of microorganisms isolated of peritoneal fluid from 160 domestic animals (2009-2023) compatible with septic peritonitis. Bacteria were isolated from 71.9% (115/160) of the peritoneal fluid from 75 dogs (75/115 = 65.2%), 22 cats (22/115 = 19.1%), 14 horses (14/115 = 12.2%), and 4 cattle (4/115 = 3.5%). Among animals with bacterial isolation, Escherichia coli (34/115 = 29.6%), alfa-hemolytic Streptococcus (12/115 = 10.4%), Staphylococcus aureus (8/115 = 6.9%), beta-hemolytic Streptococcus (7/115 = 6.1%), and Pasteurella multocida (6/115 = 5.2%) were predominant in pure culture, in addition to a miscellaneous of other bacteria isolated in minor frequency, e.g., Pseudomonas sp., Trueperella pyogenes, Klebsiella pneumoniae, and Salmonella sp. In general, in vitro susceptibility tests of isolates revealed that florfenicol, chloramphenicol, and amoxicillin/clavulanic acid showed moderate effectivity (≥ 60%). Conversely, most of isolates exhibited resistance mainly to trimethoprim/sulfamethoxazole, enrofloxacin, and penicillin (> 60%). Additionally, multidrug resistance was found in 42.6% (49/115) of the isolates. Data related to the outcome were available in 37.4% (43/115) of animals that had bacterial isolation and, from these, the mortality rate was 79.1% (34/43), with a significant association (p < 0.036) between mortality and septic peritonitis by gram-negative bacteria. Neoplasia (7/43 = 16.3%), pneumonia/pulmonary abscess (5/43 = 11.6%), hepatitis (5/43 = 11.6%), metritis/pyometra (4/43 = 9.3%), and gall bladder rupture (3/43 = 7%) represented the probable main sources of septic peritonitis. Anorexia (34/115 = 29.6%), emesis (29/115 = 25.2%), lethargy (26/115 = 22.6%), respiratory distress (25/115 = 21.7%), ascites (20/115 = 17.4%), and fever (19/115 = 16.5%) were the most frequent clinical signs among animals with bacterial isolation. A variety of bacteria were isolated in the peritoneal fluid of animals, with a predominance of Enterobacteriaceae, streptococci, and staphylococci, highlighting the opportunistic nature of the pathogens in septic peritonitis. High in vitro multidrug resistance of isolates and high mortality of animals reinforce the need for early diagnosis and therapy based on the in vitro antimicrobial profile of the pathogens involved in septic peritonitis. Our results contribute to the etiological characterization, clinical-epidemiological findings, and vigilance of multidrug-resistant bacteria in septic peritonitis among livestock and companion animals.

The Variability of the Salivary Antimicrobial Peptide Profile: Impact of Lifestyle.

Saliva is crucial in maintaining oral health; its composition reflects the body's physiological and diseased state. Among salivary components, antimicrobial peptides (AMPs) stand out for their broad antimicrobial activities and role in modulating the oral microbiota and innate immune response. Local and systemic diseases can affect the levels of AMPs in saliva, making them attractive biomarkers. However, the large variability in their concentrations hampers their use in diagnostics. Knowledge of the various factors influencing the profile of salivary AMPs is essential for their use as biomarkers. Here, we examine how lifestyle factors such as physical activity, dietary supplementation, tobacco smoking, and psychological stress impact salivary AMP levels. By understanding these sources of variability, we can take a step forward in using AMPs for diagnostics and prognostics and develop new tailored and preventative approaches.

Synthesis and evaluation of antibacterial and antibiofilm agents based on phenylamino-substituted 1,4-benzoquinones.

Aim: This work describes the synthesis and antimicrobial evaluation of 6-aminated 1,4-benzoquinones (6-AQs) against seven resistant pathogens.Materials & methods: The 6-AQs, synthesized via a Michael addition reaction between bromoquinone and p-substituted anilines, were assessed for their antimicrobial activity through both in vitro and in silico analyses.Results: Bromoquinone and 6-AQs with electron-withdrawing groups demonstrated activity against Pseudomonas aeruginosa, with minimum inhibitory concentrations ranging from 16 to 128μg/ml, comparable to standard antimicrobials. Two derivatives exhibited minimum inhibitory concentrations values against methicillin-resistant Staphylococcus aureus ranging from 64 to 128μg/ml. These compounds demonstrated both bacteriostatic and bactericidal effects, and antibiofilm features.Conclusion: The 6-AQs 19g and 19f showed a promising antimicrobial profile, indicating their potential as new therapeutic options.

Influence of enzymatic hydrolysis conditions on antimicrobial activities and peptide profiles of milk protein-derived hydrolysates from white wastewater

The focus of our investigation lies in the hydrolysis of milk proteins found in the substantial wastewater generated by the dairy industry, particularly in the white and cleaning wastewater resulting from rinsing and cleaning-in-place processes in order to enhance the value of dairy constituents by producing a diverse population of peptides, including potential antimicrobial peptides generated by 4 different enzymes: pepsin, trypsin, pronase E, and thermolysin. The protein/peptide content was influenced by the degree of hydrolysis values ranging from 2 % to 13 %, and UPLC-MS/MS characterization reveals distinct peptide sequences in enzymatic hydrolysates. The impact of hydrolysis time was also examined, revealing significant differences between 30 minutes and 240 minutes, with 555 peptides identified at 30 minutes, increasing to 693 at 240 minutes. After 4 hours, grouping showed variations: 181 peptides (thermolysin), 153 (pepsin), 126 (trypsin), and 83 (pronase E). A comparative analysis of the characterized sequences with antimicrobial peptides databases identified 17 antimicrobial peptides after 240 minutes pronase E and thermolysin hydrolysis, though they were insufficient to inhibit strains like Clostridium tyrobutyricum and Pseudomonas aeruginosa. Antimicrobial assays also revealed that peptides from Pronase T30, Pronase T240, and Thermolysine T240 exhibited antifungal activity against Mucor racemosus (MIC 2.5 mg/mL), but none against Penicillium commune. The effet of enzymatic hydrolysis demonstrated in this study highlights, for the first time, the potential for valorizing dairy white wastewater within the context of a circular economy framework.

Determination of Pathogenic E. coli and Antimicrobial Resistance Genes in dogs and human Semen: Evidence of Multidrug-Resistance and Antimicrobial Resistance Gene Profiles

Determination of Pathogenic E. coli and Antimicrobial Resistance Genes in dogs and human Semen: Evidence of Multidrug-Resistance and Antimicrobial Resistance Gene Profiles

Design, Synthesis, Molecular Docking Studies and Antimicrobial Profiling of 7-Nitroquinazoline Derivatives against Staphylococcus aureus (MRSA)

The alarming increase in antibiotic resistance contributes to the growing risk posed by Staphylococcus aureus (MRSA) in the worldwide healthcare sector. To address the challenge, this study designed, synthesized and evaluated novel quinazoline derivatives, specifically 7-nitroquinazolines, for their antimicrobial efficacy against Staphylococcus aureus (MRSA). Molecular docking studies revealed that compounds 8a and 8b exhibited superior binding affinity to the protein 1T2W, with binding energies of -9.6 kcal/mol and -8.8 kcal/mol, surpassing ciprofloxacin. The derivatives demonstrated favourable pharmacokinetic properties, including moderate lipophilicity, optimal polarity and good water solubility. Compound 8b shows a potent minimum inhibitory concentration (MIC) of 31.1 µg/mL against S. aureus (MRSA ATCC6538), outperforming ciprofloxacin. These findings indicate that compound 8b and related derivatives hold promise as novel therapeutic agents against MRSA, warranting further research to combat the growing issue of antibiotic resistance.

Udder health, bacterial isolation and antimicrobial sensitivity of Staphylococcus species from non-dairy goats on smallholder farms in Hong Kong

Abstract This research article describes an investigation into the udder health, bacterial isolation and antimicrobial sensitivity of three staphylococcal species isolated from the milk of non-dairy goats, suckling their kids, on two smallholder farms in the Hong Kong Special Administrative Region. Udder lesions were visually noted in 21 of 34 goats and two goats had palpable abnormalities. Collected milk samples grew a total of 11 bacterial organisms and the most frequently isolated organism was Staphylococcus chromogenes. Selected isolates of S. aureus, caprae and simulans from both farms were tested by antimicrobial sensitivity testing for 23 antimicrobials and all isolates showed antimicrobial resistance to doxycycline and tetracycline. Less common resistance was shown to ampicillin, chloramphenicol, penicillin and rifampicin. This preliminary study confirms the presence of udder lesions and mastitis bacteria in non-dairy goats in Hong Kong, along with the first information on the antimicrobial profile of three common Staphylococcus species bacteria affecting goats.

Genomic approach to determine sources of neonatal Staphylococcus aureus infection from carriage in the Gambia

Staphylococcus aureus is a major cause of neonatal infections in various anatomical sites, resulting in high morbidity and mortality in The Gambia. These clinical infections are often preceded by nasal carriage of S. aureus, a known risk factor. To determine whether potential sources of newborn S. aureus infections were from carriage, and to characterize S. aureus present in different anatomical sites (blood, ear, eye, umbilical cord, skin, pus, oropharynx, breast milk and vagina), we performed whole-genome sequencing of 172 isolates from clinical sites as well as from healthy and unhealthy carriage. A random selection of mothers (n = 90) and newborns (n = 42) participating in a clinical trial and testing positive for S. aureus were considered for this study. Sequence data were analyzed to determine S. aureus multilocus sequence types and selected antimicrobial and virulence gene profiles. Our findings revealed that in The Gambia, ST15 is the dominant sequence type associated with both carriage and clinical infection. In addition, S. aureus isolates causing clinical infection among neonates were genetically similar to those colonizing their oropharynx, and the different anatomical sites were not found to be uniquely colonized by S. aureus of a single genomic profile. Furthermore, while S. aureus associated with clinical infection had similar antimicrobial resistance gene profiles to carriage isolates, only hemolysin and adhesive factor virulence genes were significantly higher among clinical isolates. In conclusion, this study confirmed S. aureus oropharyngeal colonization among neonates as a potential source of clinical infection in The Gambia. Hence, interventions aiming to reduce neonatal clinical infections in The Gambia should consider decreasing oropharyngeal S. aureus carriage.Trial registration The trial was registered at ClinicalTrials.gov NCT03199547.

Genomic Profiling of Antimicrobial Resistance Genes in Clinical Salmonella Isolates from Cattle in the Texas Panhandle, USA.

Rising antimicrobial resistance (AMR) in Salmonella serotypes host-adapted to cattle is of increasing concern to the beef and dairy industry. The bulk of the existing literature focuses on AMR post-slaughter. In comparison, the understanding of AMR in Salmonella among pre-harvest cattle is still limited, particularly in Texas, which ranks top five in beef and dairy exports in the United States; inherently, the health of Texas cattle has nationwide implications for the health of the United States beef and dairy industry. In this study, long-read whole genome sequencing and bioinformatic methods were utilized to analyze antimicrobial resistance genes (ARGs) in 98 isolates from beef and dairy cattle in the Texas Panhandle. Fisher exact tests and elastic net models accounting for population structure were used to infer associations between genomic ARG profiles and antimicrobial phenotypic profiles and metadata. Gene mapping was also performed to assess the role of mobile genetic elements in harboring ARGs. Antimicrobial resistance genes were found to be statistically different between the type of cattle operation and Salmonella serotypes. Beef operations were statistically significantly associated with more ARGs compared to dairy operations. Salmonella Heidelberg, followed by Salmonella Dublin isolates, were associated with the most ARGs. Additionally, specific classes of ARGs were only present within mobile genetic elements.

Antimicrobial Susceptibility of Methicillin-resistant Staphylococcus Aureus and Methicillin-sensitive Staphylococcus Aureus in a Pediatric Tertiary Care Hospital in Southern India

Objectives: To determine the current antimicrobial sensitivity profile of MRSA and compare it with the antimicrobial sensitivity of MSSA (Methicillin Sensitive Staphylococcus aureus) Material and Methods: Antimicrobial resistance in Staphylococcus aureus is a global public health concern. Methicillin-resistant Staphylococcus aureus (MRSA) is often resistant to the many classes of antibiotics compared to the methicillin-sensitive Staphylococcus aureus (MSSA). Five hundred and fifty S. aureus isolates obtained from clinical samples of pediatric patients were studied to determine the difference in the antimicrobial susceptibility between MRSA and MSSA. Results: Out of 550 S. aureus isolates, 59.3% were MSSA, and 40.7% were MRSA. The antimicrobial sensitivity to ciprofloxacin, gentamicin, clindamycin, erythomycin, tetracycline of MSSA was 26.4% , 93.6%, 81.5%, 61.2%, 95.4% respectively, and that of MRSA was 4.9%, 56.2%, 58%, 31%, 89.8% respectively. Conclusion: Antimicrobial sensitivity to ciprofloxacin, gentamicin, clindamycin, erythromycin, and tetracycline were significantly higher in MSSA than in MRSA.

Ten-year statewide cross-sectional review of pediatric sinogenic intracranial abscess and empyema in Queensland, Australia: microbial profile before and after COVID-19.

Sinogenic intracranial infections in children, such as subdural empyema or intracranial abscess, are a rare disease process with significant associated morbidity. Recent literature has suggested that there may have been an increase in frequency of these infections following the COVID-19 pandemic, but the literature has been conflicting, perhaps related to the heterogenous management of COVID-19 lockdowns in various states and differences in data capture between methods. The collection of statewide Australian data overcomes these limitations by capturing a comprehensive sample though the public healthcare system of patients who were subject to a homogeneous statewide approach to public health policy during the COVID-19 pandemic (population 5.6 million, including 1.3 million children). The objective of this study was to present population-level data to address the question of whether the incidence of intracranial infections changed in pediatric patients before and after the COVID-19 pandemic. The authors present a retrospective 10-year statewide description of sinogenic intracranial infections in Queensland, Australia. A comparison was made between the incidence and microbiological profile before and after the onset of COVID-19 lockdowns on March 22, 2020. Forty-four pediatric intracranial infections undergoing neurosurgical intervention were identified within the review period. After exclusion of postsurgical and cardioembolic causes, 33 sinogenic intracranial infections were included (16 before and 17 after 2020, with a mean annualized incidence of 0.25 vs 0.37 cases per 100,000 children, respectively; p > 0.05). The most frequent organisms identified were Streptococcus milleri (n = 19), polymicrobial (n = 4), and S. aureus (n = 3). No significant differences in antimicrobial profile, susceptibility, parenchymal involvement, or clinical outcome were identified between the pre- and post-COVID-19 groups. No statistically significant differences in the epidemiology of pediatric intracranial infection have occurred in the state of Queensland, Australia, before and after March 22, 2020, and the COVID-19 pandemic.

Molecular Docking, Acute Toxicity and Antibacterial Study of Debilon and Phorbasterone-B Extracted from Rhodophyta

Introduction: Natural compounds obtained from marine algae, especially Rhodophyta are now being investigated for various biological activities. However, the antimicrobial activity and toxicity profile of compounds present in these algae isunderexplored. Objective: This study procured two compounds, Debilon and Phorbasterone-B, from Rhodophyta to analyze their in silico and in vitro potential against pathogenic bacterial strains and their acute toxicity. Methods: Debilon and Phorbasterone-B were extracted from Rhodophyta by a previously reported method and were further subsequently exploited computationally for their physicochemical properties, prediction of biological activity and molecular docking against bacterial proteins, toxicity, and experimentally for antibacterial potential against pathogenic strains of Vibrio cholera, Salmonella typhi, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, Bacillus subtilis, and Pseudomonas aeruginosa. Results: Docking studies proved that these molecules possess a chemical affinity for the bacterial proteins and can inhibit the growth of these microorganisms, as confirmed by antibacterial assay. Whereas the prediction analysis and toxicity studies showed that the friendliness of these molecules to the human body is enormous. Conclusion: From this study, it has been proved that DN and PB are perfect candidates for inhibiting these bacterial strains.

Use of antimicrobials in patients in Palliative Care admitted to the Intensive Care Unit: A retrospective study

Introduction: Palliative care (PC) improves the quality of life of patients and their families. The use of antimicrobials is controversial in PC patients, especially in those admitted to the intensive care unit (ICU). Objective: To evaluate the use of antimicrobials in PC patients admitted to the ICU. Methods: This is a retrospective study, performed from August 2019 to September 2020. Data on demographic profile, hospitalization, PC, and use of antimicrobials were collected from the Erasto Gaertner Hospital database, in Curitiba, Brazil. Results: 182 patients were studied, median age of 65 years and 52% men. The median length of stay in the ICU was 3 days; the median total length of stay in the hospital was 6 days and 89.5% of the patients died. The time in ICU of patients treated with antibiotics (14.8%) was significantly longer (p=0.033) than for patients who were not (85.2%). Using or not using antibiotics did not change the outcome. Among those who took antibiotics, death occurred in 81.5% of cases and among those who did not use, 74.8% died (p=0.627). Between the cases that used broad-spectrum antibiotics 17/19 (89.5%) died and the mean hospital stay was 16.2 days. Among cases that used narrow-spectrum 5/9 (62.5%) died and the mean hospital stay was 6.4 days (p=0.033). Conclusion: The administration and/or the spectrum of antibiotics in PC patients admitted to the ICU did not change the mortality rate. The administration of antibiotics increased the length of stay in the ICU.

Molecular characterization of Methicillin-resistant Staphylococcus aureus isolated in ready-to-eat food sold in supermarkets in Bobo-Dioulasso: case of charcuterie products

BackgroundStaphylococcus aureus (S. aureus) is one of the most widespread bacterial pathogens in animals and humans, and its role as an important causative agent of food poisoning is well-documented. The aim of this study was to highlight and characterize the resistance patterns of methicillin-resistant S. aureus (MRSA) in charcuterie products sold in selected supermarkets (SM) in Bobo-Dioulasso, Burkina Faso.MethodsIn this study, 72 samples including ham (n = 19), merguez (n = 22), sausage (n = 15) and minced meat (n = 16) were collected from 3 supermarkets. Standard microbiology methods were utilised to characterise S. aureus isolates. Phenotypic resistance patterns were investigated using the disk diffusion method on Mueller-Hinton agar. Genotypic testing using polymerase chain reaction (PCR) was performed on the isolates to detect the 16S-23S gene. Using specific primers, the following genes PVL, TSST-1, mecA, gyrA, gyrB, qnrA, intI1 and aac(6’)-Ib-cr were identified from purified DNA by PCR.ResultsAmong the 72 ready-to-eat food samples, S. aureus was present in 51, (70.83%). The yield was highest in both the ham and merguez food products, 15/51 (29.41%) each, followed by minced meat 12/51 (23.53%) and sausage 9/51 (17.65%). A total of 35 isolates (68.63%) were confirmed as S. aureus after molecular characterization using 16–23 S primers with 05 (14.29%) strains identified as MRSA. All of the MRSA and majority of the methicillin-sensitive S.aureus (MSSA) isolates were resistant to penicillin G, ampicillin, tetracycline and erythromycin, whereas one isolate from minced meat was found in SM3-harbouring PVL, TSST-1, mecA, gyrA, gyrB and Int1 genes.ConclusionsOur study revealed a high prevalence of S. aureus in chacuterie products in Bobo-Dioulasso with antimicrobial profiles that show resistance to most antibiotics. These findings should inform and augment efforts to raise awareness among local supermarket owners on adequate food manufacturing practices as well as promoting food safety and hygiene.

A subpopulation of human bone marrow erythroid cells displays a myeloid gene expression signature similar to that of classic monocytes.

Erythroid cells, serving as progenitors and precursors to erythrocytes responsible for oxygen transport, were shown to exhibit an immunosuppressive and immunoregulatory phenotype. Previous investigations from our research group have revealed an antimicrobial gene expression profile within murine bone marrow erythroid cells which suggested a role for erythroid cells in innate immunity. In the present study, we focused on elucidating the characteristics of human bone marrow erythroid cells through comprehensive analyses, including NanoString gene expression profiling utilizing the Immune Response V2 panel, a BioPlex examination of chemokine and TGF-beta family proteins secretion, and analysis of publicly available single-cell RNA-seq data. Our findings demonstrate that an erythroid cell subpopulation manifests a myeloid-like gene expression signature comprised of antibacterial immunity and neutrophil chemotaxis genes which suggests an involvement of human erythroid cells in the innate immunity. Furthermore, we found that human erythroid cells secreted CCL22, CCL24, CXCL5, CXCL8, and MIF chemokines. The ability of human erythroid cells to express these chemokines might facilitate the restriction of immune cells in the bone marrow under normal conditions or contribute to the ability of erythroid cells to induce local immunosuppression by recruiting immune cells in their immediate vicinity in case of extramedullary hematopoiesis.

Divergence of Phyllosphere Microbial Community Assemblies and Components of Volatile Organic Compounds between the Invasive Sphagneticola trilobata, the Native Sphagneticola calendulacea and Their Hybrids, and Its Implications for Invasiveness.

Closely-related plant groups with distinct microbiomes, chemistries and ecological characteristics represent tractable models to explore mechanisms shaping species spread, competitive dynamics and community assembly at the interface of native and introduced ranges. We investigated phyllosphere microbial communities, volatile organic compound (VOC) compositions, and potential interactions among introduced S. trilobata, native S. calendulacea and their hybrid in South China. S. trilobata exhibited higher α diversity but significantly different community composition compared to the native and hybrid groups. However, S. calendulacea and the hybrid shared certain microbial taxa, suggesting potential gene flow or co-existence. The potent antimicrobial VOC profile of S. trilobata, including unique compounds like p-cymene (13.33%), likely contributes to its invasion success. The hybrid's intermediate microbial and VOC profiles suggest possible consequences for species distribution, genetic exchange, and community assembly in heterogeneous environments. This hybrid deserves further study as both an opportunity for and threat to diversity maintenance. These differentiating yet connected plant groups provide insight into ecological and evolutionary dynamics shaping microbiome structure, species co-occurrence and competitive outcomes during biological exchange and habitat transformation. An interdisciplinary approach combining chemical and microbial ecology may reveal mechanisms underlying community stability and change, informing management of species spread in a globalized world.

Synthesis and Antimicrobial Evaluation of 1H-1,2,3-Triazole-Linked Quinoline-Phenolic Natural Product Conjugates

A new library of quinoline–natural product conjugates bearing 1,2,3-triazole moiety as a linker has been synthesized using the copper(I) catalyzed azide-alkyne [3 + 2] cycloaddition reaction (CuAAC) methodology. The structure characterization of the synthesized compounds was achieved using NMR and HRMS analysis. The compounds were subsequently screened for their antimicrobial efficacies against methicillin resistant Staphylococcus aureus (MRSA), MDR Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, Escherichia coli, Candida albicans, and Cryptococcus neoformans. The studied compounds generally displayed stronger inhibition of microbial cell growth compared to their parent phenolic natural products. Eugenol, thymol, guaiacol, and o-vanillin based 1H-1,2,3-triazole compounds exhibited the best antimicrobial profiles while the pathogen, A. baumannii showed the highest susceptibility to the hybrids. Precisely, hybrids 19a, 20b, and 25b derived from eugenol, thymol, and o-vanillin, respectively, exhibited over 50% growth inhibition of the pathogen. K. pneumoniae was however strongly resistant to the compound series. In silico docking studies of the representative compounds further explored the characteristic binding orientations of these compounds in the active sites of the bacterial and fungal proteins. Overall, we perceive that rational scaffold hopping of these compounds holds promise to offer novel antimicrobial agents with enhanced potency.

The Next Frontier in Tuberculosis Investigation: Automated Whole Genome Sequencing for Mycobacterium tuberculosis Analysis.

A fully automated bacteria whole genome sequencing (WGS) assay was evaluated to characterize Mycobacterium tuberculosis (MTB) and non-tuberculosis Mycobacterium (NTM) clinical isolates. The results generated were highly reproducible, with 100% concordance in species and sub-lineage classification and 92% concordance between antimicrobial resistance (AMR) genotypic and phenotypic profiles. Using extracted deoxyribonucleic acid (DNA) from MTB clinical isolates as starting material, these findings demonstrate that a fully automated WGS assay, with a short turnaround time of 24.5 hours, provides timely and valuable insights into MTB outbreak investigation while providing reliable genotypic AMR profiling consistent with traditional antimicrobial susceptibility tests (AST). This study establishes a favorable proposition for the adoption of end-to-end fully automated WGS solutions for decentralized MTB diagnostics, thereby aiding in World Health Organization's (WHO) vision of tuberculosis eradication.