Antibiotics and bacterial resistance in the 21st century

Advancements in MRSA treatment: the role of berberine in enhancing antibiotic therapy

BACKGROUND

Methicillin-resistant Staphylococcus aureus (MRSA) is a significant public health problem. This study investigated the antimicrobial properties and mechanisms of berberine (BBR), a plant alkaloid, against MRSA, evaluating its potential to enhance antibiotic therapy.

RESULTS

Berberine only demonstrated variable but significant inhibitory effects on 50 clinical MRSA strains. When combined with antibiotics, synergistic effects were observed only with amikacin in 6 of the 50 MRSA strains. BBR disrupted MRSA cell wall integrity, leading to leakage of cellular contents. Network pharmacology analysis revealed that BBR targets multiple pathways essential for bacterial survival.

CONCLUSION

The study confirmed the potent antimicrobial activity of berberine against MRSA and its capability to act synergistically with traditional antibiotics. Berberine's impact on cell wall integrity and bacterial survival pathways highlights its potential as an adjunct therapy in MRSA treatment.

Global prevalence of Helicobacter pylori antibiotic resistance among children in the world health organization regions between 2000 and 2023: a systematic review and meta-analysis

BACKGROUND

Helicobacter pylori infection causes gastritis, peptic ulcers, and gastric cancer. The infection is typically acquired in childhood and persists throughout life. The major impediment to successful therapy is antibiotic resistance. This systematic review and meta-analysis aimed to comprehensively assess the global prevalence of antibiotic resistance in pediatric H. pylori infection.

METHODS

We performed a systematic search of publication databases that assessed H. pylori resistance rates to clarithromycin, metronidazole, levofloxacin, amoxicillin, and tetracycline in children. The WHO region classification was used to group pooled primary and secondary resistance estimates along with 95% confidence interval (CI). H. pylori antibiotic resistance rates were retrieved and combined with odds ratios (95% CI) to investigate the global prevalence and temporal trends. Subgroup analysis of the prevalence of antibiotic resistance was conducted by country, age groups, and susceptibility testing methods.

RESULTS

Among 1417 records obtained initially, 152 studies were selected for eligibility assessment after applying exclusion criteria in multiple steps. Ultimately, 63 studies involving 15,953 individuals were included comprising data from 28 countries in 5 WHO regions. The primary resistance rates were metronidazole 35.3% (5482/15,529, 95% CI: 28.7-42.6), clarithromycin 32.6% (5071/15,555, 95% CI: 27.7-37.9), tetracycline 2.1% (148/7033, 95% CI: 1.3-3.6), levofloxacin 13.2% (1091/8271, 95% CI: 9.3-18.4), and amoxicillin 4.8% (495/10305, 95% CI: 2.5-8.8). Raising antibiotic resistance was detected in most WHO regions.

CONCLUSIONS

The escalating trend of H. pylori antibiotic resistance in children warrants urgent attention globally. National and regional surveillance networks are required for antibiotic stewardship in children infected with H. pylori.

Soil Amoebae Are Unexpected Hotspots of Environmental Antibiotics and Antibiotic Resistance Genes

Antibiotic resistance poses a significant threat to human health. While most studies focus on bacteria, interactions between antibiotics and other crucial microbial groups like protists remain uncertain. This study investigates how protists interact with antibiotics and examines how these interactions impact the fate of resistance genes. It reveals that amoebae exhibit high resistance to eight high-risk environmental antibiotics, accumulating significant quantities within their cells. Wild amoeboid strains from distant locations carry substantial antibiotic resistance genes (ARGs) and metal resistance genes (MRGs), with significant heterogeneity within a single species. Amoeboid symbionts and pathogens predominantly carry these genes. Paraburkholderia symbionts have reduced genomes and fewer resistance genes compared to free-living strains, while amoeba-endogenous Stenotrophomonas maltophilia does not exhibit a significantly reduced genome size. This suggests that the amoeboid hosts serve as a temporary medium facilitating its transmission. In summary, the study unveils that soil amoebae represent unexpected hotspots for antibiotics and resistance genes. Future research should assess the effects of antibiotics on often-overlooked protists and explore their role in spreading ARGs and MRGs in ecosystems. Incorporating protists into broader antibiotic resistance research is recommended, highlighting their significance within a One Health perspective.

Antioxidant and Antimicrobial Activities of 4H-Chromene Based Indole-Pyrimidine Hybrids: Synthesis and Molecular Docking Studies

A series of 4H-Chromene Based Indole-Pyrimidine Hybrids synthesized using simple and efficient multicomponent reaction. The title molecules were evaluated for their invitro antioxidant and antimicrobial activities. Compounds 8 g containing bromo substituted naphthalene displayed potent antioxidant activity with IC50 value of 1.09±0.34 μM and 1.10±0.36 μM. Compound 10 a, a 4-methylphenyl derivative presented potent activity with antioxidant activity with IC50 value of 1.29±0.35 μM and 1.43±0.38 μM. Subsequently, compounds 8 a, 8 b, 8 d and 10 g had shown prominent percentage of inhibition and derived effective IC50 values in comparison to reference drug Ascorbic Acid. The invitro antimicrobial activity carried out against two gram positive and two gram-negative bacteria, and two fungal strains using Ampicillin and Itraconazole as refence drugs. Compound 10 f exhibited exceptional efficacy against all types of bacterial and fungal strains compared to Ampicillin and Itraconazole, compounds 8 e and 8 g showed activity against bacterial strains whereas compound 10 g exhibited the most effective zone of inhibition against fungal strains. The molecular docking study against crystal structure of NADPH oxidase obtained supporting docking scores and showed notable binding interactions such as H-bond and hydrophobic.

Bacterial Photodynamic Inactivation: Eradication of Staphylococcus aureus and Escherichia coli Mediated by Pyridinium-Pyrazolyl Zinc(II) Phthalocyanines

Antimicrobial resistance remains an enduring global health issue, manifested when microorganisms, such as bacteria, lack responsiveness to antimicrobial treatments. Photodynamic inactivation (PDI) of microorganisms arises as a noninvasive, nontoxic, and repeatable alternative for the inactivation of a broad range of pathogens. So, this study reports the synthesis, structural characterization, and photophysical properties of a new tetra-β-substituted pyridinium-pyrazolyl zinc(II) phthalocyanine (ZnPc 1a) that was compared with two previously described pyridinium-pyrazolyl ZnPcs 2a and 3a. The PDI efficacy of these three ZnPcs (1a-3a) against a drug-resistant Gram-positive bacterium (as Staphylococcus aureus) and a Gram-negative bacterium (as Escherichia coli) is also reported. The PDI efficacy toward these bacteria was examined with ZnPcs 1a-3a in the 5.0-10.0 μM range using a white light source with an irradiance of 150 mW/cm2. All ZnPcs displayed a significant PDI activity against S. aureus, with reductions superior to 3 Log CFU/mL. Increasing the treatment time, the E. coli was inactivated until the detection limit of the method (>6.3 Log CFU/mL) using the quaternized ZnPcs 1a-3a (10.0 μM, 120 min) being the inactivation time was reduced when added the KI for ZnPcs 1a and 3a. These findings demonstrate the effective PDI performance of pyridinium-pyrazolyl group-bearing PSs, indicating their potential use as a versatile antimicrobial agent for managing infections induced by Gram-negative and Gram-positive bacteria.

Antibacterial Mechanisms and Clinical Impact of Sitafloxacin

Sitafloxacin is a 4th generation fluoroquinolone antibiotic with broad activity against a wide range of Gram-negative and Gram-positive bacteria. It is approved in Japan and used to treat pneumonia and urinary tract infections (UTIs) as well as other upper and lower respiratory infections, genitourinary infections, oral infections and otitis media. Compared to other fluoroquinolones, sitafloxacin displays a low minimal inhibitory concentration (MIC) for many bacterial species but also activity against anaerobes, intracellular bacteria, and persisters. Furthermore, it has also shown strong activity against biofilms of P. aeruginosa and S. aureus in vitro, which was recently validated in vivo with murine models of S. aureus implant-associated bone infection. Although limited in scale at present, the published literature supports the further evaluation of sitafloxacin in implant-related infections and other biofilm-related infections. The aim of this review is to summarize the chemical-positioning-based mechanisms, activity, resistance profile, and future clinical potential of sitafloxacin.

Screening for antimicrobial and antioxidant activities of quinazolinone based isoxazole and isoxazoline derivatives, synthesis and In silico studies

Two novel series of quinazolinone based isoxazole and isoxazoline hybrid compounds were synthesized from 6-aminoquinazolinone as a key precursor. The title compounds were achieved in synthetic routes via propargylation and allylation reactions of the precursor followed by cyclization with various chloroximes. The new compounds 4a-g and 6a-g were screened for their antimicrobial activity against two Gram-positive bacteria, two Gram-negative bacteria and two fungi by employing Ampicillin and Itraconazole as standard reference. Among all, the 4-bromosubstituted analogues in isoxazole series 4d and in isoxazoline series 6d demonstrated potent activity against all bacterial and fungal strains compared to Ampicillin as well as Itraconazole. The MIC of these compounds were determined as 0.012 μM. The antioxidant investigation revealed that compounds 4f and 6f with dimethyl substitution, exhibited significant activity. Their respective IC50 values were 1.28 ± 0.33, 1.39 ± 0.38 µM and 1.07 ± 0.24, 1.10 ± 0.26 µM, when compared to Ascorbic acid. The compounds 4 g and 6 g with dichloro substitution, exhibited promising results with IC50 values were 2.72 ± 0.34 µM and 2.78 ± 0.41 µM for 4 g, and 2.24 ± 0.93 µM and 2.45 ± 0.53 µM for 6 g, respectively. Their antimicrobial and antioxidant activities were authenticated by the molecular docking study against crystal structure of DNA gyrase and NADPH oxidase. The predicted ADME properties of these molecules progressed favourable drug-likeness properties.

Functional characterisation and modification of a novel Kunitzin peptide for use as an anti-trypsin antimicrobial peptide against drug-resistant Escherichia coli

In recent decades, antimicrobial peptides (AMPs) have emerged as highly promising candidates for the next generation of antibiotic agents, garnering significant attention. Although their potent antimicrobial activities and ability to combat drug resistance make them stand out among alternative agents, their poor stability has presented a great challenge for further development. In this work, we report a novel Kunitzin AMP, Kunitzin-OL, from the frog Odorrana lividia, exhibiting dual antimicrobial and anti-trypsin activities. Through functional screening and comparison with previously reported Kunitzin peptides, we serendipitously discovered a unique motif (-KVKF-) and unveiled its crucial role in the antibacterial functions of Kunitzin-OL by modifying it through motif removal and duplication. Among the designed derivatives, peptides 4 and 8 demonstrated remarkable antimicrobial activities and low cytotoxicity, with high therapeutic index (TI) values (TI4 = 20.8, TI8 = 20.8). Furthermore, they showed potent antibacterial efficacy against drug-resistant Escherichia coli strains and exhibited lipopolysaccharide (LPS)-neutralising activity, effectively alleviating LPS-induced inflammatory responses. Overall, our findings provide a new short motif for designing effective AMP drugs and highlight the potential of the Kunitztin trypsin inhibitory loop as a valuable motif for the design of AMPs with enhancing proteolytic stability.

Review: Antimicrobial resistance of Klebsiella pneumoniae isolated from poultry, cattle and pigs

Klebsiella pneumoniae, common pathogenic bacteria, cause dangerous infectious diseases in animals and humans. Klebsiella pneumoniae have numerous resistance mechanisms to antibacterials and the frequency of resistant K. pneumoniae isolates increases, making treatment of K. pneumoniae-induced infections difficult. Farm animals are a possible source of antibacterial resistant K. pneumoniae. The aim of this literature review (2018-2024) was to evaluate the antibacterial resistance of K. pneumoniae isolated from poultry, cattle and pigs in various countries. The analysis shows that farm animals are an important source of antibacterial-resistant and multidrug-resistant K. pneumoniae and that resistance patterns differ among antibacterial groups, animals and locations. In poultry, high resistance to penicillins (91%), III and IV generation cephalosporins (> 50%) occurred, and low to carbapenems (5%) and polymyxins (6%). In cattle, high resistance to sulphonamides (76%), IV generation cephalosporins, macrolides and lincosamides, and penicillins occurred (> 50%), and low to carbapenems (10%) and polymyxins (1%). Isolates from pigs showed high resistance to I and II-generation cephalosporins, I-generation fluoroquinolones, macrolides and lincosamides, tetracyclines (> 50%) and carbapenems (> 20%), and low to polymyxins (5%). The highest resistance rates to most antibacterial groups occurred in pigs, and in Africa and Asia, while the lowest in cattle, and in North and South America. Particularly, the relatively high resistance of K. pneumoniae to carbapenems and polymyxins in Africa poses a threat to animal and human health as these antibiotics are the last resort therapeutics used to treat severe infections. Different rates of K. pneumoniae resistance to antibacterials among isolates from farm animals probably result from differences in the treatment of each animal group with various antibacterial agents and different regimes of their use in various locations.

Designing potential lead compounds targeting aminoglycoside N (6')-acetyltransferase in Serratia marcescens: A drug discovery strategy

Serratia marcescens is an opportunistic human pathogen that causes urinary tract infections, ocular lens infections, and respiratory tract infections. S. marcescens employs various defense mechanisms to evade antibiotics, one of which is mediated by aminoglycoside N-acetyltransferase (AAC). In this mechanism, the enzyme AAC facilitates the transfer and linkage of the acetyl moiety from the donor substrate acetyl-coenzyme A to specific positions on antibiotics. This modification alters the antibiotic's structure, leading to the inactivation of aminoglycoside antibiotics. In the current scenario, antibiotic resistance has become a global threat, and targeting the enzymes that mediate resistance is considered crucial to combat this issue. The study aimed to address the increasing global threat of antibiotic resistance in Serratia marcescens by targeting the aminoglycoside N-acetyltransferase (AAC (6')) enzyme, which inactivates aminoglycoside antibiotics through acetylation. Due to the absence of experimental structure, we constructed a homology model of aminoglycoside N (6')-acetyltransferase (AAC (6')) of S. marcescens using the atomic structure of aminoglycoside N-acetyltransferase AAC (6')-Ib (PDB ID: 1V0C) as a template. The stable architecture and integrity of the modelled AAC (6') structure were analyzed through a 100 ns simulation. Structure-guided high-throughput screening of four small molecule databases (Binding, Life Chemicals, Zinc, and Toslab) resulted in the identification of potent inhibitors against AAC (6'). The hits obtained from screening were manually clustered, and the five hit molecules were shortlisted based on the docking score, which are observed in the range of -17.09 kcal/mol to -11.95 kcal/mol. These selected five molecules displayed acceptable pharmacological properties in ADME predictions. The binding free energy calculations, and molecular dynamics simulations of ligand bound AAC (6') complexes represented higher affinity and stable binding. The selected molecules demonstrated stable binding with AAC (6'), indicating their strong potential to hamper the binding of aminoglycoside in the respective site. and thereby inhibit. This process mitigates enzyme mediated AAC (6') activity on aminoglycosides and reverse the bactericidal function of aminoglycosides, and also this method could serve as a platform for the development of potential antimicrobials.

In vitro antimicrobial activities, molecular docking and density functional theory (DFT) evaluation of natural product-based vanillin derivatives featuring halogenated azo dyes

Chemical modification of active scaffolds from natural products has gained interest in pharmaceutical industries. Nevertheless, the metabolites extraction is time-consuming while the lead is frequently mismatched with the receptor. Here, the diazo coupling approach was introduced to generate a series of vanillin derivatives featuring halogenated azo dyes (1a-h). The vanillin derivatives showed effective inhibition of S. aureus (7-9 mm) and E. coli (7-8 mm) compared to the parent vanillin, while 1b had the highest inhibition zone (9 mm) against S. aureus comparable to the reference ampicillin. The presence of N = N, C = O, -OH, -OCH3 and halogens established strategic binding interactions with the receptor. The potential vanillin-azo as an antimicrobial drug was supported by in silico docking with penicillin-binding proteins and DFT (using Gaussian 09) with binding affinity -7.5 kcal/mol and energy gap (Egap) 3.77 eV, respectively. This study represents a significant advancement in drug discovery for effective antibiotics with excellent properties.

Integrative metagenomic dissection of last-resort antibiotic resistance genes and mobile genetic elements in hospital wastewaters

Hospital wastewater is a critical source of antimicrobial resistance (AMR), which facilitates the proliferation and spread of clinically significant antimicrobial resistance genes (ARGs) and pathogenic bacteria. This study utilized metagenomic approaches, including advanced binning techniques, such as MetaBAT2, MaxBin2, and CONCOCT, which offer significant improvements in accuracy and completeness over traditional binning methods. These methods were used to comprehensively assess the dynamics and composition of resistomes and mobilomes in untreated wastewater samples taken from two general hospitals and one cancer hospital. This study revealed a diverse bacterial landscape, largely consisting of Proteobacteria, Firmicutes, Bacteroidetes, and Actinobacteria, with notable variations in microbial composition among hospitals. Analysis of the top 15 genera showed unique microbial pattern distribution in each hospital: Aeromonas was predominant in 1stHWTS (49.39 %), Acidovorax in the CAHWTS at 16.85 %, and Escherichia and Bacteroides in the 2ndHWTS at 11.44 % and 11.33 %, respectively. A total of 114 pathogenic bacteria were identified, with drug-resistant Aeromonas caviae and Escherichia coli being the most prevalent. The study identified 34 types and 1660 subtypes of ARGs, including important last-resort antibiotic resistance genes (LARGs), such as blaNDM, mcr, and tet(X). Using metagenomic binning, this study uncovered distinct patterns of host-resistance associations, particularly with Proteobacteria and Firmicutes. Network analysis highlighted the complex interactions among ARGs, mobile genetic elements (MGEs), and bacterial species, all contributing to the dissemination of AMR. These findings emphasize the intricate nature of AMR in hospital wastewater and the influence of hospital-specific factors on microbial resistance patterns. This study provides support for implementing integrated management strategies, including robust surveillance, advanced wastewater treatment, and strict antibiotic stewardship, to control the dissemination of AMR. Understanding the interplay among bacterial communities, ARGs, and MGEs is important for developing effective public health measures against AMR.

Risk factors associated with multidrug-resistant Klebsiella pneumoniae infections: a multicenter observational study in Lebanese hospitals

BACKGROUND

Klebsiella pneumoniae is a significant global public health burden, especially in low-income countries and regions with fragile healthcare infrastructures, due to its ability to cause severe infections, increase mortality rates, and its rising antimicrobial resistance. This study aimed to estimate the proportion of multidrug-resistant (MDR) K. pneumoniae infections and identify associated risk factors.

METHODS

Data were retrospectively collected from three academic hospitals in Beirut, Lebanon, between January 2021 and September 2023 using a standardized form. Binary logistic regression was used to determine risk factors associated with MDR, extended-spectrum beta-lactamase (ESBL)-producing, and carbapenem-resistant K. pneumoniae (CRKP) infections.

RESULTS

Out of 2,655 K. pneumoniae cases, 410 met the inclusion criteria. The primary infection sources were the urinary tract (58.3%) and the respiratory tract (12.4%). Among the isolates, 61% were MDR K. pneumoniae, with 7.3% being extensively drug-resistant, and 0.5% pandrug-resistant. Additionally, 36.8% were ESBL-producing, while 6.3% were CRKP. Predictors significantly associated with MDR K. pneumoniae infections included male sex (adjusted odds ratio [AOR] = 3.46, 95% CI = 1.01-11.86, P = 0.04), recent antibiotics use (AOR = 4.52, 95% CI = 1.65-12.36, P = 0.003), and recent cancer chemotherapy (AOR = 3.43, 95% CI = 1.25-9.42, P = 0.01). ESBL-producing infections were associated with age ≥ 65 years, higher Charlson Comorbidity Index (CCI), and recent antibiotic use. CRKP infections were linked to male sex, prior antibiotic use, and longer hospital stays prior to infection (all P < 0.05).

CONCLUSIONS

MDR K. pneumoniae infections are steadily rising in Lebanon, along with an increase in ESBL-producing and CRKP cases. The main risk factors for MDR K. pneumoniae infections were male sex, recent antibiotic use, and cancer chemotherapy. ESBL-producing infections were associated with advanced age, higher CCI, and recent antibiotic use, while CRKP infections were linked to male sex, prior antibiotic use, and prolonged hospital stays. This situation is further exacerbated by inadequate healthcare infrastructure and suboptimal national surveillance. Strengthening local surveillance and implementing effective antibiotic stewardship programs are critical to managing this growing threat..

AmpClass: an Antimicrobial Peptide Predictor Based on Supervised Machine Learning

In the last decades, antibiotic resistance has been considered a severe problem worldwide. Antimicrobial peptides (AMPs) are molecules that have shown potential for the development of new drugs against antibiotic-resistant bacteria. Nowadays, medicinal drug researchers use supervised learning methods to screen new peptides with antimicrobial potency to save time and resources. In this work, we consolidate a database with 15945 AMPs and 12535 non-AMPs taken as the base to train a pool of supervised learning models to recognize peptides with antimicrobial activity. Results show that the proposed tool (AmpClass) outperforms classical state-of-the-art prediction models and achieves similar results compared with deep learning models.

The Synergy between Antibiotics and the Nanoparticle-Based Photodynamic Effect

Antimicrobial resistance (AMR) is a growing global health concern, necessitating innovative strategies beyond the development of new antibiotics. Here, we employed NdYVO4:Eu3+ nanoparticles, which can persistently produce reactive oxygen species (ROS) after stopping the light, as a model of photodynamic nanoparticles and demonstrated that the photodynamic effect can serve as an adjuvant with antibiotics to effectively reduce their minimum inhibitory concentration. These preirradiated nanoparticles could penetrate the bacterial cell membrane, significantly enhancing the potency of antibiotics. We showed that the synergy effect could be attributed to disrupting crucial cellular processes by ROS, including damaging cell membrane proteins, interfering with energy supply, and inhibiting antibiotic metabolism. Our findings suggested that complementing the photodynamic effect might be a robust strategy to enhance antibiotic potency, providing an alternative antibacterial treatment paradigm.

Genome sequencing and analysis of penicillin V producing Penicillium rubens strain BIONCL P45 isolated from India

BACKGROUND

A filamentous fungus Penicillium rubens is widely recognized for producing industrially important antibiotic, penicillin at industrial scale.

OBJECTIVE

To better comprehend, the genetic blueprint of the wild-type P. rubens was isolated from India to identify the genetic/biosynthetic pathways for phenoxymethylpenicillin (penicillin V, PenV) and other secondary metabolites.

METHOD

Genomic DNA (gDNA) was isolated, and library was prepared as per Illumina platform. Whole genome sequencing (WGS) was performed according to Illumina NovoSeq platform. Further, SOAPdenovo was used to assemble the short reads validated by Bowtie-2 and SAMtools packages. Glimmer and GeneMark were used to dig out total genes in genome. Functional annotation of predicted proteins was performed by NCBI non-redundant (NR), UniProt, Kyoto Encyclopedia of Genes and Genomes (KEGG), and Gene Ontology (GO) databases. Moreover, secretome analysis was performed by SignalP 4.1 and TargetP v1.1 and carbohydrate-active enzymes (CAZymes) and protease families by CAZy database. Comparative genome analysis was performed by Mauve 2.4.0. software to find genomic correlation between P. rubens BIONCL P45 and Penicillium chrysogenum Wisconsin 54-1255; also phylogeny was prepared with known penicillin producing strains by ParSNP tool.

RESULTS

Penicillium rubens BIONCL P45 strain was isolated from India and is producing excess PenV. The 31.09 Mb genome was assembled with 95.6% coverage of the reference genome P. chrysogenum Wis 54-1255 with 10687 protein coding genes, 3502 genes had homologs in NR, UniProt, KEGG, and GO databases. Additionally, 358 CAZymes and 911 transporter coding genes were found in genome. Genome contains complete pathways for penicillin, homogentisate pathway of phenyl acetic acid (PAA) catabolism, Andrastin A, Sorbicillin, Roquefortine C, and Meleagrin. Comparative genome analysis of BIONCL P45 and Wis 54-1255 revealed 99.89% coverage with 2952 common KEGG orthologous protein-coding genes. Phylogenetic analysis revealed that BIONCL P45 was clustered with Fleming's original isolate P. rubens IMI 15378.

CONCLUSION

This genome can be a helpful resource for further research in developing fermentation processes and strain engineering approaches for high titer penicillin production.

Bactericidal activity of esculetin is associated with impaired cell wall synthesis by targeting glutamate racemase of Neisseria gonorrhoeae

Neisseria gonorrhoeae (NG), the causative organism of gonorrhea, has been classified by the World Health Organization as 'Priority' two organism owing to its increased resistance to antibiotics and even failure of recommended dual therapy with ceftriaxone and azithromycin. As a result, the general and reproductive health of infected individuals is severely compromised. The imminent public health catastrophe of antimicrobial-resistant gonococci cannot be understated, as t he of severe complications and sequelae of infection are not only increasing but their treatment has also become more expensive. Tenacious attempts are underway to discover novel drug targets as well as new drugs to fight against NG. Therefore, a considerable number of phytochemicals have been tested for their remedial intercession via targeting bacterial proteins. The MurI gene encodes for an enzyme called glutamate racemase (MurI) that is primarily involved in peptidoglycan (PG) biosynthesis and is specific to the bacterial kingdom and hence can be exploited as a potential drug target for the treatment of bacterial diseases. Accordingly, diverse families of phytochemicals were screened in silico for their binding affinity with N. Gonorrhoeae MurI (NG-MurI) protein. Esculetin, one of the shortlisted compounds, was evaluated for its functional, structural, and anti-bacterial activity. Treatment with esculetin resulted in growth inhibition, cell wall damage, and altered permeability as revealed by fluorescence and electron microscopy. Furthermore, esculetin inhibited the racemization activity of recombinant, purified NG-MurI protein, one of the enzymes required for peptidoglycan biosynthesis. Our results suggest that esculetin could be further explored as a lead compound for developing new drug molecules against multidrug-resistant strains.

Engineered Bacteriophage-Polymer Nanoassemblies for Treatment of Wound Biofilm Infections

The antibacterial efficacy and specificity of lytic bacteriophages (phages) make them promising therapeutics for treatment of multidrug-resistant bacterial infections. Restricted penetration of phages through the protective matrix of biofilms, however, may limit their efficacy against biofilm infections. Here, engineered polymers were used to generate noncovalent phage-polymer nanoassemblies (PPNs) that penetrate bacterial biofilms and kill resident bacteria. Phage K, active against multiple strains of Staphylococcus aureus, including methicillin-resistant S. aureus (MRSA), was assembled with cationic poly(oxanorbornene) polymers into PPNs. The PPNs retained phage infectivity, while demonstrating enhanced biofilm penetration and killing relative to free phages. PPNs achieved 3-log10 bacterial reduction (∼99.9%) against MRSA biofilms in vitro. PPNs were then incorporated into Poloxamer 407 (P407) hydrogels and applied onto in vivo wound biofilms, demonstrating controlled and sustained release. Hydrogel-incorporated PPNs were effective in a murine MRSA wound biofilm model, showing a 1.5-log10 reduction in bacterial load compared to a 0.5 log reduction with phage K in P407 hydrogel. Overall, this work showcases the therapeutic potential of phage K engineered with cationic polymers for treating wound biofilm infections.

Antimicrobial resistance profiles of and associated risk factors for Pseudomonas aeruginosa nosocomial infection among patients at two tertiary healthcare facilities in Lusaka and Copperbelt Provinces, Zambia

Background

Antimicrobial resistance (AMR) of pathogens such as Pseudomonas aeruginosa is among the top 10 threats to global health. However, clinical and molecular data are scarce in Zambia. We, therefore, evaluated the AMR profiles of P. aeruginosa nosocomial infections (NIs).

Methods

A year-long hospital-based cross-sectional study was conducted at two large tertiary-level hospitals in Zambia. Patients with current or previous hospital contact were screened for NIs. The current study focused on patients diagnosed with P. aeruginosa NIs. Clinical specimens were collected for bacteriological culture, and PCR amplification of 16S rRNA gene fragments was performed on pure isolates. Hospital or NIs were defined as infections that arise during hospitalization, occurring at least 48 h after admission. The Kirby-Bauer's disk diffusion method was used to evaluate antibiotic resistance patterns. The association between AMR and risk factors was analysed using the χ2 test.

Results

Eight hundred and forty-one patients were screened, and clinical specimens were collected and analysed. Of them, 116 (13.7%) were diagnosed with P. aeruginosa NIs. The participants' ages ranged from 15 to 98 years, with a mean of 51 (SD ± 18). Catheter-associated urinary tract infections (57%) were the most common, followed by pressure sores (38.7%). P. aeruginosa isolates were primarily susceptible to amikacin, which had the highest resistance to FEP. We observed a high prevalence of multidrug resistance (73.6%). The AMR was associated with carbapenem-hydrolysing β-lactamase gene blaOXA-51 and surgical care.

Conclusions

This study has demonstrated that multidrug-resistant P. aeruginosa is prevalent in hospitals in Zambia's Lusaka and Ndola districts and possibly countrywide.

Bacteriophage as a potential biotherapeutics to combat present-day crisis of multi-drug resistant pathogens

The rise of Multi-Drug Resistant (MDR) bacterial pathogens to most, if not all, currently available antibacterial agents has become a global threat. As a consequence of the antibiotic resistance epidemic, phage therapy has emerged as a potential alternative to conventional antibiotics. Despite the high therapeutic advantages of phage therapy, they have not yet been successfully used in the clinic due to various limitations of narrow host specificity compared to antibiotics, poor adhesion on biofilm surface, and susceptibility to both human and bacterial defences. This review focuses on the antibacterial effect of bacteriophage and their recent clinical trials with a special emphasis on the underlying mechanism of lytic phage action with the help of endolysin and holin. Furthermore, recent clinical trials of natural and modified endolysins and some marketed products have also been emphasized with future prospective.

On the potential activity of hyaluronic acid as an antimicrobial agent: experimental and computational validations

This century has seen the rise of antibiotic resistance as a significant public health problem. In addition, oxidative stress may also be a factor in selecting resistant strains of bacteria. The current study analyzed microbially produced hyaluronic acid's antibacterial activity and antioxidant activity. It had significant antibacterial action against strains of Staphylococcus aureus and Escherichia coli, with the IC50 value obtained being 487.65 µg mL-1 for antioxidant assay. Our molecular docking investigations of hyaluronic acid on tyrosyl-tRNA synthetase (Staphylococcus aureus: -6.13 kcal/mol, Escherichia coli: -5.79 kcal/mol) and topoisomerase II DNA gyrase (Staphylococcus aureus: -5.02 kcal/mol, Escherichia coli: -4.90 kcal/mol) confirmed the ligands' possible binding mode to the appropriate targets' sites. We also employed molecular dynamics simulation and showed that HA binds more strongly with 1JIL (-85.455 ± 12.623 kJ/mol) compared to 2YXN (-49.907 ± 64.191 kJ/mol), 5CDP (-47.285 ± 13.925 kJ/mol), and 6RKS (-45.306 ± 21.338 kJ/mol). We also report that the ligand forms several hydrogen bonds in molecular simulation, implying regular interaction with key residues of the enzymes. The results in this study indicate the potential use of HA in the vast field of applications having both asthetic and medicinal values.

Aptamers: precision tools for diagnosing and treating infectious diseases

Infectious diseases represent a significant global health challenge, with bacteria, fungi, viruses, and parasitic protozoa being significant causative agents. The shared symptoms among diseases and the emergence of new pathogen variations make diagnosis and treatment complex. Conventional diagnostic methods are laborious and intricate, underscoring the need for rapid, accurate techniques. Aptamer-based technologies offer a promising solution, as they are cost-effective, sensitive, specific, and convenient for molecular disease diagnosis. Aptamers, which are single-stranded RNA or DNA sequences, serve as nucleotide equivalents of monoclonal antibodies, displaying high specificity and affinity for target molecules. They are structurally robust, allowing for long-term storage without substantial activity loss. Aptamers find applications in diverse fields such as drug screening, material science, and environmental monitoring. In biomedicine, they are extensively studied for biomarker detection, diagnostics, imaging, and targeted therapy. This comprehensive review focuses on the utility of aptamers in managing infectious diseases, particularly in the realms of diagnostics and therapeutics.

Antioxidant and Antibacterial Activities of Selected Medicinal Plants from Addis Ababa against MDR-Uropathogenic Bacteria

This study determined the antioxidant and antibacterial activities of Thymus schimperi (Ts), Rhamnus prinoides (Rp), and Justicia schimperiana (Js) from Addis Ababa against MDR-Uropathogenic bacteria. Accordingly, Thymus schimperi had the highest total phenolic (TPC), flavonoid (TFC) and proanthocyanidin content. In Ts, the GC-MS analyses predicted 14 bioactive compounds. And among these, hexanedioic acid, bis(2-ethylhexyl) ester, thymol, and o-cymen-5-ol were the most predominant compounds, respectively. Six compounds were also predicted in Rp, where hexanedioic acid, bis(2-ethylhexyl) ester, β-D-glucopyranoside, methyl, and desulphosinigrin were the predominant, respectively. Whereas in the Js extract, five bioactive compounds were predicted, with hexanedioic acid, mono (2-ethylhexyl) ester, debrisoquine, and 8,11,14-heptadecatrienoate, methyl ester being predominant compounds, respectively. The extracts' TPC showed a strong negative correlation with the DPPH (2,2-diphenyl-1-picrylhydrazyl) assay (r = -0.999; p = 0.023). In addition, the TFC correlated significantly with the ABTS (2,2'-azino-di-(3-ethylbenzthiazoline sulfonic acid)) assay (r = 0.999; p = 0.032). Thymus schimperi showed the highest antibacterial activity against clinical isolates of Escherichia coli and Klebsiella pneumoniae ESBL at 1000 mg/mL, and Ts had the lowest MIC (4 mg/mL) among evaluated extracts against E. coli (ATCC25922). In conclusion, Ts and Rp possess higher predicted bioactive molecules, including antioxidant and antibacterial activities, which are potentially useful in treating urinary tract infections.

Reckoning with COVID-19 denial: Brazil's exemplary model for global response

In the aftermath of the coronavirus disease 2019 (COVID-19) pandemic in Brazil, accountability is crucial for those who denied the severity of the virus, spreading false information and causing harm. Some individuals have already faced legal proceedings against them, revealing economic motivations behind their actions. It is equally important to hold doctors accountable for prescribing ineffective treatments, putting the population at risk. The leaders of the denial movement and the federal government, who mishandled the pandemic, should be held accountable for the high death toll. Seeking justice from the legislative and executive branches is necessary, along with exemplary measures for those who spread misinformation about COVID-19.

Antibiotics: From Mechanism of Action to Resistance and Beyond

Antibiotics are the super drugs that have revolutionized modern medicine by curing many infectious diseases caused by various microbes. They efficiently inhibit the growth and multiplication of the pathogenic microbes without causing adverse effects on the host. However, prescribing suboptimal antibiotic and overuse in agriculture and animal husbandry have led to the emergence of antimicrobial resistance, one of the most serious threats to global health at present. The efficacy of a new antibiotic is high when introduced; however, a small bacterial population attains resistance gradually and eventually survives. Understanding the mode of action of these miracle drugs, as well as their interaction with targets is very complex. However, it is necessary to fulfill the constant need for novel therapeutic alternatives to address the inevitable development of resistance. Therefore, considering the need of the hour, this article has been prepared to discuss the mode of action and recent advancements in the field of antibiotics. Efforts has also been made to highlight the current scenario of antimicrobial resistance and drug repurposing as a fast-track solution to combat the issue.

Community awareness initiative about antimicrobial resistance: An educational intervention by medical undergraduates

BACKGROUND

Antimicrobial resistance (AMR) is a global problem and an important consequence of inappropriate use of antimicrobial agents (AMAs). Studies have observed that a lack of awareness of AMR among healthcare professionals as well as consumers results in the irrational use of AMAs, a significant driver of AMR.

MATERIALS AND METHODS

This educational intervention study was undertaken to assess community awareness regarding AMAs and AMR and to educate them. Ten volunteer students from II MBBS were made aware of AMR, its impact and measures to reduce resistance through a lecture by Pharmacology faculty. Students interacted with 220 family representatives in the community to assess their knowledge about AMAs and AMR using a 15-item pre-validated questionnaire. Charts, videos, and role-play were used to impart knowledge about the rational use of AMAs, AMR, and its consequences. Participants' understanding was ensured with feedback taken on Lickert scale.

RESULTS

Students interacted with the study participants and found that most were aware of the term 'antibiotic' (90.8%), but 67% were clueless regarding antibiotic resistance. The purpose of AMA use was not adequately known to 43% as they mentioned using these for diarrhea, viral fever, cough, cold, and sore throat. AMAs were purchased by 40% of participants as OTC medicine, whereas Azithromycin and Amoxicillin were the AMAs they could remember by name. The reasons for buying OTC antibiotics were the inconvenience of doctors' clinic timings, unaffordable consultation charges, and easy antibiotic availability. Students also learned about communication etiquette during this community interaction. This educational intervention proved helpful as the participants agreed that the unnecessary use of AMAs makes them ineffective and AMR is preventable by simple measures.

CONCLUSION

A multifactorial approach involving prescribers, regulatory Government authorities and general public is needed to control irrational use of antimicrobials. Timely interventions are necessary to increase the awareness of AMR in the community.

Antibiotic susceptibility pattern among children admitted to a hospital in Nigeria: A retrospective study

Background

The impact of antimicrobial resistance on children living in resource-limited countries has been underreported, despite its established global threat.

Objective

This retrospective study aimed to describe the trend of antibiotic susceptibility in the paediatric age group.

Methods

Sensitivity test report data consisting of 300 paediatric patients aged 18 hours to 192 months were retrieved from the microbiology laboratory records at a state-owned children's hospital in Nigeria over a period of 4 months starting from December 2021 to March 2022. Five genera (Escherichia coli, Klebsiella spp., Pseudomonas spp., Staphylococcus aureus and Streptococcus spp.) were cultured as recommended by the Clinical Laboratory Standard Institute, using the Kirby Bauer disc diffusion method. Antimicrobial susceptibility testing was carried out on isolates using 15 different antibiotics.

Results

Staphylococcus aureus was the most frequent pathogen isolated 32.1% (50/156) and Pseudomonas spp. was the least frequent pathogen isolated 7.1% (11/156) in all samples. The isolates with the highest rate of resistance to the tested antibiotics were S. aureus 32.1% (50/156), E. coli 28.2% (44/156) and Klebsiella spp. 20.5% (32/156). Isolates in all age groups were more resistant to ampicillin, amoxicillin + clavulanic acid, cefuroxime and cefepime.

Conclusion

Antibiotic resistance is high, especially the younger Nigerian children. Strict antibiotic protocols should be adhered to especially in the use of empirical antibiotic therapy in hospitals.

What this study adds

Our study reveals a higher trend of antibiotic resistance, especially in younger children. It further shows that the pathogens are most resistant to the most available empirical antibiotics in Nigeria.

Genomic analysis of Oceanotoga teriensis strain UFV_LIMV02, a multidrug-resistant thermophilic bacterium isolated from an offshore oil reservoir

Bacteria of the species Oceanotoga teriensis belong to the family Petrotogaceae, are Gram-negative bacilli, are moderately thermophilic and are included in the group of thiosulfate-reducing bacteria, being capable of significantly accelerating corrosion in metallic structures. However, no in-depth study on the genome, antibiotic resistance and mobile elements has been carried out so far. In this work, the isolation, phenotypic and genotypic characterization of the multi-resistant O. teriensis UFV_LIMV02 strain was carried out, from water samples from an offshore oil extraction platform in Rio de Janeiro (Brazil). We determined that the isolate has a genome of 2 812 778 bp in size, with 26 % GC content, organized into 34 contigs. Genomic annotation using Rapid Annotation using Subsystem Technology revealed the presence of genes related to resistance to antibiotics and heavy metals. By evaluating the antimicrobial resistance of the isolate using the disc diffusion technique, resistance was verified for the classes of antibiotics, beta-lactams, fluoroquinolones, aminoglycosides, sulfonamides, lincosamides and rifamycins, a total of 14 antibiotics. The search for genomic islands, prophages and defence systems against phage infection revealed the presence of five genomic islands in its genome, containing genes related to resistance to heavy metals and antibiotics, most of which are efflux pumps and several transposases. No prophage was found in its genome; however, nine different defence systems against phage infection were detected. When analysing the clustered regularly interspaced short palindromic repeat (CRISPR) systems, four CRISPR arrays, classified as types I-B and III-B, with 272 spacers, can provide the strain with immunity to different mobile genetic elements and bacteriophage infection. The results found in this study show that the isolate UFV_LIVM02 is an environmental bacterium, resistant to different classes of antibiotics, and that the proteins encoded by the predicted genomic islands may be associated with the development of greater resistance to antibiotics and heavy metals. They provide evidence that environmental bacteria found in offshore oil exploration residues may pose a risk for the spread of antibiotic resistance genes. More comprehensive studies on the microbial community present in oil waste are needed to assess the risks of horizontal gene transfer.

Plant-Derived Antimicrobials and Their Crucial Role in Combating Antimicrobial Resistance

Antibiotic resistance emerged shortly after the discovery of the first antibiotic and has remained a critical public health issue ever since. Managing antibiotic resistance in clinical settings continues to be challenging, particularly with the rise of superbugs, or bacteria resistant to multiple antibiotics, known as multidrug-resistant (MDR) bacteria. This rapid development of resistance has compelled researchers to continuously seek new antimicrobial agents to curb resistance, despite a shrinking pipeline of new drugs. Recently, the focus of antimicrobial discovery has shifted to plants, fungi, lichens, endophytes, and various marine sources, such as seaweeds, corals, and other microorganisms, due to their promising properties. For this review, an extensive search was conducted across multiple scientific databases, including PubMed, Elsevier, ResearchGate, Scopus, and Google Scholar, encompassing publications from 1929 to 2024. This review provides a concise overview of the mechanisms employed by bacteria to develop antibiotic resistance, followed by an in-depth exploration of plant secondary metabolites as a potential solution to MDR pathogens. In recent years, the interest in plant-based medicines has surged, driven by their advantageous properties. However, additional research is essential to fully understand the mechanisms of action and verify the safety of antimicrobial phytochemicals. Future prospects for enhancing the use of plant secondary metabolites in combating antibiotic-resistant pathogens will also be discussed.

Differential Age-Based Response Induced by a Commercial Probiotic Supplementation in Pastured Goats

The potential benefit of probiotics in small ruminant production systems has largely been unexplored. We evaluated the effect of a goat commercial probiotic on health and performance indicators in pastured goats from birth until 10 months. We randomly allocated 26 newborn nursing goat kids to two groups: a control group that received saline and a treatment group that received a commercial probiotic paste orally. We evaluated select observable health indicators (inappetence, diarrhea, coughing), weight, immunity (IgA, IgG, and innate immune response), total protein, hematocrit (HCT), total lactic acid bacteria (LAB), total coliforms, and prevalence of Escherichia coli (E. coli) primary virulence genes (stx1, stx2, and eae) during the experimental period. The results revealed no significant differences in the health indicators, LAB count, and total E. coli count. Prevalence of stx1 at 1 week of age and both stx1 and stx2 genes 4 months post-weaning was significantly (P < 0.05) higher in probiotic-supplemented goats. Probiotic supplementation significantly (P < 0.05) increased the total protein and IgA 1 month post-supplementation during the pre-weaning period and innate immune markers 2 days post-weaning. The HCT in probiotic-supplemented goats was significantly (P < 0.05) higher at 1 and 2 months post-weaning. The growth rate was not affected by probiotic supplementation in pre- and peri-weaned goats but was significantly (P < 0.05) lowered in goats older than 4 months in the supplemented group. In this pastured goat production study, there were mixed responses to a commercial probiotic in healthy goats based on age. The study suggests that early daily probiotic supplementation in pre-weaned pastured goats may have immune stimulation benefits, but in older healthy animals, post-weaning net benefits are unclear and further research is recommended.

Antibiotic Resistance Profiles of Escherichia coli and Salmonella spp. Isolated From Dairy Farms and Surroundings in a Rural Area of Western Anatolia, Turkey

Background Antibiotic resistance is a significant public health issue worldwide. Antibiotic-resistant zoonotic bacteria such as Escherichia coli (E. coli), Campylobacter, Salmonella, Listeria, Coxiella, and Mycobacterium can be particularly isolated from biofertilizers. Epidemiological studies have shown that cases of foodborne infections and intoxications are significantly related to animal-derived foods. The presence of these species in aquatic environments indicates areas or organisms contaminated with animal or human feces. Especially, the presence of E. coli in aquatic environments has become a serious problem worldwide. Pathogenic strains of E. coli cause waterborne and foodborne diseases. Materials and methods This study included a total of 290 samples collected from five different dairy farms between April and September 2023 which comprised 20 samples of cow manure, 20 samples of milk, three samples of dairy workers' hand washing water, five samples of soil, five samples of water, and five samples of vegetables. The samples taken from the farms were homogenized with 0.1% peptone water at a ratio of 1/10. They were then cultured on xylose lysine deoxycholate (XLD), eosin methylene blue agar (EMB), and blood agar media, and gram-negative colonies were identified using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) and the VITEK2 automated system (BioMerieux Inc., Durham, NC). Amplification of the isolated DNA extracts was performed with A.B.T.™ 2X HS-PCR MasterMix (A.B.T Laboratory Industry, Arnavutköy, Turkey) in the SimpliAmp™ thermal cycler (Thermo Fischer Scientific Inc., Waltham, MA) and visualized by agarose gel electrophoresis. Results Among the 52 E. coli strains isolated in our study, the highest antibiotic sensitivity rate was observed in meropenem, while the lowest sensitivity rates were determined in cefazolin and cefuroxime. While two of the Salmonella spp. (n = 2) isolates were found to be resistant to tetracycline, and one was found to be resistant to penicillin and ampicillin. No resistance to trimethoprim/sulfamethoxazole was detected in either isolate. Extended-spectrum beta-lactamases (ESBLs) were detected in only four (7.7%) E. coli strains. While tetA, tetB, and TEM genes were seen in almost all E. coli strains, they were not found in Salmonella spp. Conclusion In conclusion, our study revealed the presence of antimicrobial resistance genes in E. coli and Salmonella spp. isolates collected from various farms and environmental samples, which render the antimicrobials used for disease treatment ineffective. Consequently, research should be undertaken to prevent the development of new resistance genes in our country, as creating new medications and treatment strategies for these diseases is costly and time-intensive.

[After the pandemic is before the pandemic: And how interdisciplinary research can help here]

Aviation is among the social sectors most impacted by the COVID-19 pandemic, and at the same time has contributed to the rapid global spread of the SARS-CoV-2 virus. SARS-CoV-2 is one of the coronaviruses that have led to outbreaks such as MERS-CoV in the past. This group of pathogens, as well as others that may be unknown at this time, will continue to challenge our society in the future. In order to be able to react better, a research training group was established at DLR in cooperation with 6 institutes, which will develop interdisciplinary approaches to researching and combating current and future pandemics. Engineers, physicists, software developers, biologists and physicians are working closely together on new concepts and the development of interdisciplinary knowledge in order to better control and contain future pandemics and to be able to react in a more targeted manner. One focus is the reduction of germ contamination in airplanes but also in other means of public transport such as buses and trains. In this review, we provide an overview of the baseline situation and possible approaches to address future pandemic challenges.

Food safety control in poultry industry: prevalence and antimicrobial susceptibility of Escherichia coli isolated from raw chicken and the potential use of Origanum essential oils as alternative to antibiotics

1. The extensive use of antimicrobials in poultry production may contribute to the emergence of resistant bacteria. This study was conducted to determine the prevalence and resistance of different E. coli strains isolated from raw chicken meat and to investigate the possibility to use Lebanese native oregano essential oils as alternatives.2. In total, 250 chickens from Lebanese markets were examined for the presence of E. coli. Isolates were then screened for susceptibility using 19 antibiotics and two essential oils extracted from oregano plants.3. Of the 250 chickens tested, 80% were contaminated with E. coli. Main resistance was seen against amoxycillin, ampicillin, penicillin, tetracycline, tylosin, streptomycin and erythromycin. The highest rate of sensitivity was found in 86.1% of strains to Amoxycillin/Clavulanic acid, 80.09% to Tilmicosin. Both essential oils from Origanum syriacum (98%) and O. ehrenbergii (97.3%) showed promising potential in inhibiting the growth of the tested bacteria. Oil from O. syriacum exhibited superior efficacy against 200 E. coli strains, inhibiting 46.1% at 200 mg/l and all at 400 mg/l, while O. ehrenbergii oil showed slightly lower inhibition, affecting 41.6% at 200 mg/l and all at 400 mg/l.

Enhancing the efficacy of antimicrobial photodynamic therapy through curcumin modifications

Curcumin serves as a photosensitizer (PS) in the context of microbial inactivation when subjected to light exposure, to produce reactive oxygen species, which exhibit efficacy in eradicating microorganisms. This remarkable property underscores the growing potential of antimicrobial photodynamic therapy (aPDT) in the ongoing fight against bacterial infections. Considering this, we investigate the efficacy of various in vitro curcumin formulations within a PDT protocol designed to target Staphylococcus aureus. Specifically, we conduct a comparative analysis involving synthetic curcumin (Cur-Syn) and curcumin derivatives modified with chlorine (Cl), selenium (Se), and iodine (I) (Cur-Cl, Cur-Se, Cur-I). To assess the impact of aPDT, we subject S. aureus to incubation with curcumin, followed by irradiation at 450 nm with energy doses of 3.75, 7.5, and 15 J/cm2. Our investigation encompasses an evaluation of PS uptake and photobleaching across the various curcumin variants. Notably, all three modifications (Cur-Cl, Cur-Se, Cur-I) induce a significant reduction in bacterial viability, approximately achieving a 3-log reduction. Interestingly, the uptake kinetics of Cur-Syn and Cur-Se exhibit similarities, reaching saturation after 20 min. Our findings suggest that modifications to curcumin have a discernible impact on the photodynamic properties of the PS molecule.

Modelling the implementation of narrow versus broader spectrum antibiotics in the empiric treatment of E. coli bacteraemia

The implementation of new antimicrobial resistance stewardship programs is crucial in optimizing antibiotic use. However, prescription choices can be difficult during empiric therapy; clinicians must balance the survival benefits of broader spectrum antibiotics with associated increases in resistance. The aim of this study was to evaluate the overall feasibility of switching to narrow spectrum antibiotics during the empiric treatment of E. coli bacteraemia by quantifying changes in resistance rates, antibiotic usage, and mortality using a deterministic state-transition model. Three unique model scenarios (A, B, and C), each representing a progressively broader spectrum empiric treatment regimen, were used to compare outcomes at 5 years. We show that the empiric use of the narrowest spectrum (first-line) antibiotics can lead to reductions in resistance to second-line antibiotics and the use of third-line antibiotics, but they also lead to increases in resistance to first-line therapy and higher mortality. Crucially, we find that shortening the duration of empiric and overall treatment, as well as reducing the baseline mortality rate, are important for increasing the feasibility of switching to narrow spectrum antibiotics in the empiric treatment of E. coli bacteraemia. We provide a flexible model design to investigate optimal treatment approaches for other bacterial infections.

Antibacterial Potential of Non-Tailed Icosahedral Phages Alone and in Combination with Antibiotics

Non-tailed icosahedral phages belonging to families Fiersviridae (phages MS2 and Qbeta), Tectiviridae (PRD1) and Microviridae (phiX174) have not been considered in detail so far as potential antibacterial agents. The aim of the study was to examine various aspects of the applicability of these phages as antibacterial agents. Antibacterial potential of four phages was investigated via bacterial growth and biofilm formation inhibition, lytic spectra determination, and phage safety examination. The phage phiX174 was combined with different classes of antibiotics to evaluate potential synergistic interactions. In addition, the incidence of phiX174-insensitive mutants was analyzed. The results showed that only phiX174 out of four phages tested against their corresponding hosts inhibited bacterial growth for  > 90% at different multiplicity of infection and that only this phage considerably prevented biofilm formation. Although all phages show the absence of potentially undesirable genes, they also have extremely narrow lytic spectra. The synergism was determined between phage phiX174 and ceftazidime, ceftriaxone, ciprofloxacin, macrolides, and chloramphenicol. It was shown that the simultaneous application of agents is more effective than successive treatment, where one agent is applied first. The analysis of the appearance of phiX174 bacteriophage-insensitive mutants showed that mutations occur with a frequency of 10-3. The examined non-tailed phages have a limited potential for use as antibacterial agents, primarily due to a very narrow lytic spectrum and the high frequency of resistant mutants appearance, but Microviridae can be considered in the future as biocontrol agents against susceptible strains of E. coli in combinations with conventional antimicrobial agents.

The role of gaming for information, education and communication of AMR: full review of online education resources

Background

The first objective of the Global Action Plan on antimicrobial resistance (AMR) is to improve awareness and understanding of AMR through effective communication, education and training. Towards this several efforts have been made to create AMR awareness resources. The aim of these resources is to inform the public about responsible antibiotic use and drive positive behavioural change. Digital media and specifically games can serve as unique innovative platforms in public communication programmes.

Objectives

This study focuses on compiling and evaluating game-based AMR resources. Recognizing the engaging and creative potential of games as learning tools, the primary objective of this study was to identify games that can be used, individually or in combination depending on their unique focus and gameplay experience, for AMR awareness. Furthermore, games are evaluated on five objective criteria and recommendations are made towards further development of gaming resources towards AMR awareness.

Methods

Meticulous curation was performed to mine information, education and communication resources, with a primary focus on games for AMR awareness and evaluating them based on game design and gameplay, AMR content and learning, engagement and replay appeal, learning outcomes, and level of difficulty and challenges.

Results

In this study, we selected 12 AMR games. Our evaluations, spanning various gamification elements and interactive parameters, informed recommendations for future AMR resource development, including multilevel game design, varied graphics, simple-to-understand rules, sustained challenge and a sense of reward, among others.

Conclusions

This study generated the first-ever comprehensive catalogue of AMR games that may assist public communication programmes for AMR awareness. Evaluation of these games led to actionable design recommendations for future resources towards effective communication of AMR complexity, enhanced learning and awareness.

Bioinspired and Green Synthesis of Silver Nanoparticles for Medical Applications: A Green Perspective

Silver nanoparticles (AgNPs) possess unmatched chemical, biological, and physical properties that make them unique compounds as antimicrobial, antifungal, antiviral, and anticancer agents. With the increasing drug resistance, AgNPs serve as promising entities for targeted drug therapy against several bacterial, fungal, and viral components. In addition, AgNPs also serve as successful anticancer agents against several cancers, including breast, prostate, and lung cancers. Several works in recent years have been done towards the development of AgNPs by using plant extracts like flowers, leaves, bark, root, stem, and whole plant parts. The green method of AgNP synthesis thus has several advantages over chemical and physical methods, especially the low cost of synthesis, no toxic byproducts, eco-friendly production pathways, can be easily regenerated, and the bio-reducing potential of plant derived nanoparticles. Furthermore, AgNPs are biocompatible and do not harm normally functioning human or host cells. This review provides an exhaustive overview and potential of green synthesized AgNPs that can be used as antimicrobial, antifungal, antiviral, and anticancer agents. After a brief introduction, we discussed the recent studies on the development of AgNPs from different plant extracts, including leaf parts, seeds, flowers, stems, bark, root, and whole plants. In the following section, we highlighted the different therapeutic actions of AgNPs against various bacteria, fungi, viruses, and cancers, including breast, prostate, and lung cancers. We then highlighted the general mechanism of action of AgNPs. The advantages of the green synthesis method over chemical and physical methods were then discussed in the article. Finally, we concluded the review by providing future perspectives on this promising field in nanotechnology.

Secondary metabolite fingerprinting, anti-pathogenic activity, elite chemotype selection and conservation of Curcuma caesia- an ethnomedicinally underutilized species

Curcuma caesia Roxb. is an ethnomedicinally important, essential oil (EO) yielding aromatic plant. A total of twelve accessions of this plant rhizome were collected from six different agro-climatic zones of West Bengal, India and evaluated for their antimicrobial activities against eight disease-causing, multi-drug-resistant pathogenic strains of urinary-tract infection and respiratory-tract infection. The EO and extracts demonstrated antibacterial activity, with the highest inhibition zone of 18.00 ± 0.08 and 17.50 ± 0.14 mm against Klebsiella pneumoniae by accession 06, even where all the broad-spectrum antibiotics failed to respond. In this study, we employed high-performance thin-layer chromatography (HPTLC) to quantify curcumin, the primary secondary metabolite of C. caesia, and the highest 0.228 mg/gm of curcumin resulted from accession 06. Hence, on the basis of all aspects, accession 06 was identified as the elite chemotype among all twelve accessions. The chemical profiling of EO from accession 06 was done using gas chromatography-mass spectroscopy (GC-MS). Conceivably, about 13 medicinally significant compounds were detected. As this plant species is seasonal and has difficulties in conventional breeding due to dormancy, it must be conserved through in vitro tissue culture for a steady supply throughout the year in massive amounts for agricultural demand. A maximum number of 19.28 ± 0.37 shoots has been obtained in MS medium fortified with 6-Benzylaminopurine, Kinetin, and Naphthalene acetic acid. The genetic uniformity of the plants has been studied through Start Codon Targeted Polymorphism. Therefore, this study must help meet the need for essential phytoactive compounds through a simple, validated, and reproducible plant tissue culture protocol throughout the year.

Biochemical characterization of actinomycete from Namibia rocky crest mountainous soil and analyzing their bioactive metabolites for antagonistic effect against human respiratory pathogens

Introduction

the present study aimed at isolating and characterizing actinomycete from unexplored Windhoek rocky crest mountainous soil and extracting bioactive metabolites as possible therapeutics against common life-threatening Streptococcus pneumonia (S. pneumonia) and Stachybotrys chartarum (S. chartarum).

Methods

chemotaxonomy and biochemical methods were used to identify the isolates. The solvent extraction method was used to extract bioactive compounds. Agar overlay and disc diffusion methods were used to determine the antimicrobial activity of isolates and extracted bioactive metabolites against S. pneumonia and S. chartarum. The antioxidant activity of the extracted bioactive metabolites was determined using 2.2-diphenyl-1-picrylhydrazyl (DPPH) free radical scavenging method with ascorbic acid as a positive control. Comparison between groups was done using a Two-way ANOVA, followed by Bonferroni post-test.

Results

three distinct isolates from 3 soil samples were identified on starch casein agar and distinguished using biochemical tests. All three isolates showed strong inhibitory activity against S. pneumonia with average growth inhibition zones between 18.0±1.00 and 27±0.00 mm p< 0.005. All isolates showed potent inhibitory activity against S. chartarum with the average inhibition zones ranging between 42.0±1.00 and 48±0.00 mm, p< 0.005. The chloroform extracts showed potent DPPH activity of up to 73± 1.41%.

Conclusion

growth conditions and extraction solvents can influence the antimicrobial and antioxidant properties of bioactive metabolites.

Identification of novel inhibitors for trigger factor (TF) of M. tb: an in silico investigation

Trigger factor, as a chaperone protein, is required for survival of Mycobacterium tuberculosis (M.tb) in a stressed environment. This protein interacts with various partners in both the pre- and the post-translation processes, yet the crystal structures of the M.tb trigger factor remain unresolved. In this study, we developed a homology model of M.tb trigger factor to facilitate the discovery and design of inhibitors. To validate the model, we employed several methodologies, including Ramachandran plot and molecular dynamics simulations. The simulations showed a stable trajectory, indicating the accuracy of the model. The active site of M.tb Trigger Factor was identified based on site scores, and virtual screening of over 70,000 compounds led to the identification of two potential hits: HTS02984 (ethyl 2-(3-(4-fluorophenyl)ureido)-6-methyl-4,5,6,7-tetrahydrothieno[2,3-c]pyridine-3-carboxylate) and S06856 ((E)-N-(4-((2-(4-(tert-butyl)benzoyl)hydrazono)methyl)phenyl) acetamide). These compounds showed strong binding affinity and energy scores, and their chemical descriptors were evaluated. Our study provides a reliable computational model for M.tb Trigger Factor and identifies two potential inhibitors for this crucial protein, which could aid in the development of novel therapies against tuberculosis.Communicated by Ramaswamy H. Sarma.

The Rising Tide of Antibiotic Resistance: A Study on Extended-Spectrum Beta-Lactamase and Carbapenem-Resistant Escherichia coli and Klebsiella pneumoniae

BACKGROUND

The global spread of extended-spectrum beta-lactamase (ESBL)-producing and carbapenem-resistant Enterobacterales (CRE) poses a significant concern. Acquisition of antimicrobial resistance genes leads to resistance against several antibiotics, limiting treatment options. We aimed to study ESBL-producing and CRE transmission in clinical settings.

METHODS

From clinical samples, 227 ESBL-producing and CRE isolates were obtained. The isolates were cultured on bacterial media and confirmed by VITEK 2. Antibiograms were tested against several antibiotics using VITEK 2. The acquired resistance genes were identified by PCR.

RESULTS

Of the 227 clinical isolates, 145 (63.8%) were Klebsiella pneumoniae and 82 (36.1%) were Escherichia coli; 76 (33.4%) isolates were detected in urine, 57 (25.1%) in pus swabs, and 53 (23.3%) in blood samples. A total of 58 (70.7%) ESBL-producing E. coli were resistant to beta-lactams, except for carbapenems, and 17.2% were amikacin-resistant; 29.2% of E. coli isolates were resistant to carbapenems. A total of 106 (73.1%) ESBL-producing K. pneumoniae were resistant to all beta-lactams, except for carbapenems, and 66.9% to ciprofloxacin; 38 (26.2%) K. pneumoniae were resistant to carbapenems. Colistin emerged as the most effective antibiotic against both bacterial types. Twelve (20.6%) E. coli isolates were positive for blaCTX-M, 11 (18.9%) for blaTEM, and 8 (33.3%) for blaNDM. Forty-six (52.3%) K. pneumoniae isolates had blaCTX-M, 27 (18.6%) blaTEM, and 26 (68.4%) blaNDM.

CONCLUSION

This study found a high prevalence of drug-resistant ESBL-producing and CRE, highlighting the need for targeted antibiotic use to combat resistance.

Appendectomy versus antibiotic treatment for acute appendicitis

BACKGROUND

Acute appendicitis is one of the most common emergency general surgical conditions worldwide. Uncomplicated/simple appendicitis can be treated with appendectomy or antibiotics. Some studies have suggested possible benefits with antibiotics with reduced complications, length of hospital stay, and the number of days off work. However, surgery may improve success of treatment as antibiotic treatment is associated with recurrence and future need for surgery.

OBJECTIVES

To assess the effects of antibiotic treatment for uncomplicated/simple acute appendicitis compared with appendectomy for resolution of symptoms and complications.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, and two trial registers (World Health Organization International Clinical Trials Registry Platform and ClinicalTrials.gov) on 19 July 2022. We also searched for unpublished studies in conference proceedings together with reference checking and citation search. There were no restrictions on date, publication status, or language of publication.

SELECTION CRITERIA

We included parallel-group randomised controlled trials (RCTs) only. We included studies where most participants were adults with uncomplicated/simple appendicitis. Interventions included antibiotics (by any route) compared with appendectomy (open or laparoscopic).

DATA COLLECTION AND ANALYSIS

We used standard methodology expected by Cochrane. We used GRADE to assess the certainty of evidence for each outcome. Primary outcomes included mortality and success of treatment, and secondary outcomes included number of participants requiring appendectomy in the antibiotic group, complications, pain, length of hospital stay, sick leave, malignancy in the antibiotic group, negative appendectomy rate, and quality of life. Success of treatment definitions were heterogeneous although mainly based on resolution of symptoms rather than incorporation of long-term recurrence or need for surgery in the antibiotic group.

MAIN RESULTS

We included 13 studies in the review covering 1675 participants randomised to antibiotics and 1683 participants randomised to appendectomy. One study was unpublished. All were conducted in secondary care and two studies received pharmaceutical funding. All studies used broad-spectrum antibiotic regimens expected to cover gastrointestinal bacteria. Most studies used predominantly laparoscopic surgery, but some included mainly open procedures. Six studies included adults and children. Almost all studies aimed to exclude participants with complicated appendicitis prior to randomisation, although one study included 12% with perforation. The diagnostic technique was clinical assessment and imaging in most studies. Only one study limited inclusion by sex (male only). Follow-up ranged from hospital admission only to seven years. Certainty of evidence was mainly affected by risk of bias (due to lack of blinding and loss to follow-up) and imprecision. Primary outcomes It is uncertain whether there was any difference in mortality due to the very low-certainty evidence (Peto odds ratio (OR) 0.51, 95% confidence interval (CI) 0.05 to 4.95; 1 study, 492 participants). There may be 76 more people per 1000 having unsuccessful treatment in the antibiotic group compared with surgery, which did not reach our predefined level for clinical significance (risk ratio (RR) 0.91, 95% CI 0.87 to 0.96; I2 = 69%; 7 studies, 2471 participants; low-certainty evidence). Secondary outcomes At one year, 30.7% (95% CI 24.0 to 37.8; I2 = 80%; 9 studies, 1396 participants) of participants in the antibiotic group required appendectomy or, alternatively, more than two-thirds of antibiotic-treated participants avoided surgery in the first year, but the evidence is very uncertain. Regarding complications, it is uncertain whether there is any difference in episodes of Clostridium difficile diarrhoea due to very low-certainty evidence (Peto OR 0.97, 95% CI 0.24 to 3.89; 1 study, 1332 participants). There may be a clinically significant reduction in wound infections with antibiotics (RR 0.25, 95% CI 0.09 to 0.68; I2 = 16%; 9 studies, 2606 participants; low-certainty evidence). It is uncertain whether antibiotics affect the incidence of intra-abdominal abscess or collection (RR 1.58, 95% CI 0.61 to 4.07; I2 = 19%; 6 studies, 1831 participants), or reoperation (Peto OR 0.13, 95% CI 0.01 to 2.16; 1 study, 492 participants) due to very low-certainty evidence, mainly due to rare events causing imprecision and risk of bias. It is uncertain if antibiotics prolonged length of hospital stay by half a day due to the very low-certainty evidence (MD 0.54, 95% CI 0.06 to 1.01; I2 = 97%; 11 studies, 3192 participants). The incidence of malignancy was 0.3% (95% CI 0 to 1.5; 5 studies, 403 participants) in the antibiotic group although follow-up was variable. Antibiotics probably increased the number of negative appendectomies at surgery (RR 3.16, 95% CI 1.54 to 6.49; I2 = 17%; 5 studies, 707 participants; moderate-certainty evidence).

AUTHORS' CONCLUSIONS

Antibiotics may be associated with higher rates of unsuccessful treatment for 76 per 1000 people, although differences may not be clinically significant. It is uncertain if antibiotics increase length of hospital stay by half a day. Antibiotics may reduce wound infections. A third of the participants initially treated with antibiotics required subsequent appendectomy or two-thirds avoided surgery within one year, but the evidence is very uncertain. There were too few data from the included studies to comment on major complications.

Quinolone scaffolds as potential drug candidates against infectious microbes: a review

Prevalence of microbial infections and new rising pathogens are signified as causative agent for variety of serious and lethal health crisis in past years. Despite medical advances, bacterial and fungal infections continue to be a rising problem in the health care system. As more bacteria develop resistance to antibiotics used in therapy, and as more invasive microbial species develop resistance to conventional antimicrobial drugs. Relevant published publications from the last two decades, up to 2024, were systematically retrieved from the MEDLINE/PubMed, SCOPUS, EMBASE, and WOS databases using keywords such as quinolones, anti-infective, antibacterial, antimicrobial resistance and patents on quinolone derivatives. With an approach of considerable interest towards novel heterocyclic derivatives as novel anti-infective agents, researchers have explored these as essential tools in vistas of drug design and development. Among heterocycles, quinolones have been regarded extremely essential for the development of novel derivatives, even able to tackle the associated resistance issues. The quinolone scaffold with its bicyclic structure and specific functional groups such as the carbonyl and acidic groups, is indeed considered a valuable functionalities for further lead generation and optimization in drug discovery. Besides, the substitution at N-1, C-3 and C-7 positions also subjected to be having a significant role in anti-infective potential. In this article, we intend to highlight recent quinolone derivatives based on the SAR approach and anti-infective potential such as antibacterial, antifungal, antimalarial, antitubercular, antitrypanosomal and antiviral activities. Moreover, some recent patents granted on quinolone-containing derivatives as anti-infective agents have also been highlighted in tabular form. Due consideration of this, future research in this scaffold is expected to be useful for aspiring scientists to get pharmacologically significant leads.

A Study of Metabolites from Basidiomycota and Their Activities against Pseudomonas aeruginosa

The World Health Organization (WHO) promotes research aimed at developing new drugs from natural compounds. Fungi are important producers of bioactive molecules, and they are often effective against other fungi and/or bacteria and are thus a potential source of new antibiotics. Basidiomycota crude extracts, which have previously been proven to be active against Pseudomonas aeruginosa ATCC27853, were subjected to liquid chromatographic separation by RP-18, leading to six macro-fractions for each fungal extract. The various fractions were tested for their bioactivities against P. aeruginosa ATCC27853, and ten of them were characterized by HPLC-HRMS and NMR. Further chromatographic separations were performed for a few selected macro-fractions, yielding seven pure compounds. Bioactivity was mainly found in the lipophilic fractions containing fatty acids and their derivatives, such as hydroxy or keto C-18 unsaturated acids, and in various complex lipids, such as glycolipids and related compounds. More hydrophilic molecules, such as GABA, phenethylamine, two chromogenic anthraquinoids and pistillarin, were also isolated, and their antibacterial activities were recorded. The novelties of this research are as follows: (i) the genera Cortinarius and Mycena have never been investigated before for the synthesis of antibiotic compounds; (ii) the molecules produced by these genera are known, but their production has never been reported in the investigated fungi; (iii) the determination of bacterial siderophore synthesis inhibition by certain compounds from Cortinarius and Mycena.

Assessment of Biofilm Forming Capability and Antibiotic Resistance in Proteus mirabilis Colonizing Indwelling Catheter

<b>Background and Objective:</b> Urinary tract infections from the use of an indwelling urinary catheter are one of the most common infections caused by <i>Proteus mirabilis</i>. Due to their biofilm-producing capacity and the increasing antimicrobial resistance in this microorganism, this study aimed to determine the prevalence, biofilm-producing capacity, antimicrobial resistance patterns, multidrug resistance and plasmid mediated resistance of the recovered isolates. <b>Materials and Methods:</b> A total of 50 urinary samples were collected from May to August, 2018 from patients on indwelling urinary catheters. Using routine microbiological and biochemical methods, 37 <i>P. mirabilis</i> were isolated. Biofilm forming capability was determined among the isolates using the tube method while antimicrobial susceptibility and plasmid curing were also performed. <b>Results:</b> All isolates were biofilm producers with 17(46%) being moderate producers while 20(54%) were strong biofilm formers. The study isolates exhibited a high resistance rate to empiric antibiotics, including ceftazidime (75.8%), cefuroxime (54.5%), ampicillin (69.7%) and amoxicillin-clavulanic acid (51.5%). Low resistance was seen in the fluoroquinolones, gentamicin and nitrofurantoin. Plasmid curing experiment revealed that most isolates lost their resistance indicating that resistance was borne on plasmids. Plasmid carriage is likely the reason for the high MDR rate of 56.8% observed. <b>Conclusion:</b> These findings necessitate the provision of infection control programs which will guide and implement policies.

Molecular modeling and biological investigation of novel s-triazine linked benzothiazole and coumarin hybrids as antimicrobial and antimycobacterial agents

A novel series of s-triazine linked benzothiazole and coumarin hybrids (6a-6d, 7a-7d, and 8a-8d) were synthesized and characterized by IR, NMR, and mass spectrometry. The compound's in vitro antibacterial and antimycobacterial activities were also evaluated. Remarkable antibacterial activity with MIC in the range of 12.5-62.5 μM and antifungal activity of 100-200 μM were demonstrated by in vitro antimicrobial analysis. Compounds 6b, 6d, 7b, 7d, and 8a strongly inhibited all bacterial strains, while 6b, 6c, and 7d had good to moderate efficacy against M. tuberculosis H37Rv. Synthesized hybrids are observed in the active pocket of the S. aureus dihydropteroate synthetase enzyme, according to a molecular docking investigations. Among the docked compounds, 6d had a strong interaction and a greater binding affinity, and the dynamic stability of protein-ligand complexes was examined using molecular dynamic simulation with various settings at 100 ns. The proposed compounds successfully maintained their molecular interaction and structural integrity inside the S. aureus dihydropteroate synthase, according to the MD simulation analysis. These in silico analyses supported the in vitro antibacterial results of compound 6d, which demonstrated outstanding in vitro antibacterial efficacy against all bacterial strains. In the quest for new antibacterial drug-like molecules, compounds 6d, 7b, and 8a have been identified as promising lead compounds.Communicated by Ramaswamy H. Sarma.

Cultivation of monoxenous trypanosomatids: A minireview

Trypanosomatids are obligatory parasites, some of which are responsible for important human and animal diseases, but the vast majority of trypanosomatids are restricted to invertebrate hosts. Isolation and in vitro cultivation of trypanosomatids from insect hosts enable their description, characterization, and subsequently genetic and genomic studies. However, exact nutritional requirements are still unknown for most trypanosomatids and thus very few defined media are available. This mini review provides information about the role of different ingredients, recommendations and advice on essential supplements and important physicochemical parameters of culture media with the aim of facilitating first attempts to cultivate insect-infesting trypanosomatids, with a focus on monoxenous trypanosomatids.

Unlocking the Potential of Substrate Quality for the Enhanced Antibacterial Activity of Black Soldier Fly against Pathogens

Globally, antibiotics are facing fierce resistance from multidrug-resistant bacterial strains. There is an urgent need for eco-friendly alternatives. Though insects are important targets for antimicrobial peptides, it has received limited research attention. This study investigated the impact of waste substrates on the production of antibacterial agents in black soldier fly (Hermetia illucens L.) larvae (HIL) and their implications in the suppression of pathogens [Bacillus subtilis (ATCC 6051), Staphylococcus aureus (ATCC 25923), Pseudomonas aeruginosa (ATCC 27853), and Escherichia coli (ATCC 25922)]. The 20% acetic acid (AcOH) extract from market waste had the highest antibacterial activity with an inhibition zone of 17.00 mm, followed by potato waste (15.02 mm) against S. aureus. Hexane extract from HIL raised on market waste also showed a significant inhibitory zone (13.06 mm) against B. subtilis. .Minimum inhibitory concentration (MIC) values recorded were 25 mg/mL against all test pathogens. The fastest time-kill of 20% AcOH extract was 4 h againstB. subtilis, E. coli, ,andP. aeruginosa. Lauric acid was also identified as the dominant component of the various hexane extracts with concentrations of 602.76 and 318.17 μg/g in HIL reared on potato and market waste, respectively. Energy from the market waste substrate correlated significantly (r = 0.97) with antibacterial activities. This study highlights the key role of substrate quality and extraction methods for enhancing the production of antibacterial agents in HIL, thus providing new insights into the development of potential drugs to overcome the alarming concerns of antimicrobial resistance.

Theoretical Improvements in Enzyme Efficiency Associated with Noisy Rate Constants and Increased Dissipation

Previous studies have revealed the extraordinarily large catalytic efficiency of some enzymes. High catalytic proficiency is an essential accomplishment of biological evolution. Natural selection led to the increased turnover number, kcat, and enzyme efficiency, kcat/KM, of uni-uni enzymes, which convert a single substrate into a single product. We added or multiplied random noise with chosen rate constants to explore the correlation between dissipation and catalytic efficiency for ten enzymes: beta-galactosidase, glucose isomerase, β-lactamases from three bacterial strains, ketosteroid isomerase, triosephosphate isomerase, and carbonic anhydrase I, II, and T200H. Our results highlight the role of biological evolution in accelerating thermodynamic evolution. The catalytic performance of these enzymes is proportional to overall entropy production-the main parameter from irreversible thermodynamics. That parameter is also proportional to the evolutionary distance of β-lactamases PC1, RTEM, and Lac-1 when natural or artificial evolution produces the optimal or maximal possible catalytic efficiency. De novo enzyme design and attempts to speed up the rate-limiting catalytic steps may profit from the described connection between kinetics and thermodynamics.