Treatment Of Bacterial Infections Research Articles

Artificial intelligence applications in the diagnosis and treatment of bacterial infections

The diagnosis and treatment of bacterial infections in the medical and public health field in the 21st century remain significantly challenging. Artificial Intelligence (AI) has emerged as a powerful new tool in diagnosing and treating bacterial infections. AI is rapidly revolutionizing epidemiological studies of infectious diseases, providing effective early warning, prevention, and control of outbreaks. Machine learning models provide a highly flexible way to simulate and predict the complex mechanisms of pathogen-host interactions, which is crucial for a comprehensive understanding of the nature of diseases. Machine learning-based pathogen identification technology and antimicrobial drug susceptibility testing break through the limitations of traditional methods, significantly shorten the time from sample collection to the determination of result, and greatly improve the speed and accuracy of laboratory testing. In addition, AI technology application in treating bacterial infections, particularly in the research and development of drugs and vaccines, and the application of innovative therapies such as bacteriophage, provides new strategies for improving therapy and curbing bacterial resistance. Although AI has a broad application prospect in diagnosing and treating bacterial infections, significant challenges remain in data quality and quantity, model interpretability, clinical integration, and patient privacy protection. To overcome these challenges and, realize widespread application in clinical practice, interdisciplinary cooperation, technology innovation, and policy support are essential components of the joint efforts required. In summary, with continuous advancements and in-depth application of AI technology, AI will enable doctors to more effectivelyaddress the challenge of bacterial infection, promoting the development of medical practice toward precision, efficiency, and personalization; optimizing the best nursing and treatment plans for patients; and providing strong support for public health safety.

Exploring probiotic potential and antimicrobial properties of lactic acid bacteria from cow's milk

One of the most important foods in the world is milk, due to its nutrients and composition. Milk also contains lactic acid bacteria (LABs), which can produce antimicrobial compounds and organic acids; an essential factor in developing different methods to control other bacteria. Another critical factor is that several species of LABs are considered potential probiotics, offering several health benefits. This study aimed to isolate, identify LABs, characterize the antimicrobial susceptibility profile, and evaluate the inhibition potential against Staphylococcus aureus (ATCC 25923), Listeria monocytogenes (ATCC 7644), Escherichia coli (ATCC 25922) and Salmonella Typhimurium (ATCC 14028); as well as verifying the acidification capacity, survival of simulated in vitro gastrointestinal conditions and identification of virulence genes and bacteriocin-producing genes. The study was carried out with LABs previously isolated from milk of cows with clinical mastitis, low and high (Somatic Cells Count) in herds from all regions of Brazil (South, Southeast, Central-West, North, and Northeast). One hundred and ten strains were selected for identification using the MALDI-TOF technique. The genera with the most significant spectrum of action were Lactococcus, Lactobacillus, and Pediococcus in the antimicrobial action test against pathogens, concluding that Lactobacillus showed resistance to several antibiotics. The analysis of antimicrobial action made it possible to verify the potential production of antimicrobial compounds by LABs against the primary pathogens of food origin. The most significant reduction in pH could be observed from 24 h to 48 h, ranging from 6.8 (0 h) to 4.74 (48 h) for Lactobacillus and Lactococcus. All isolates survived tolerance tests at pH=3.0 and bile salts (0.5 %), with survival rates ranging from 34.2 to 69.9 % at pH = 3.0 and above 82 % at 0.5 % bile salts. Lacotococcus and Lactobacillus isolates presented the plnEF and plnNC8 genes. This study contributes to the search for alternatives in the treatment of bacterial infections with a reduction in the use of antibiotics, which, due to the increase in bacterial resistance, is causing difficulties in treating diseases caused by these microorganisms. pH is an important parameter when it comes to food safety and conservation. Tolerance to acid stress and bile salts are important properties in evaluating probiotic potential and the ability to maintain high counts under these conditions. The presence of the plnEF and plnNC8 genes suggests bacteriocin production.

In vitro antibacterial, antibiofilm activities, and phytochemical properties of Posidonia oceanica (L.) Delile: An endemic Mediterranean seagrass

In the antibiotic resistance era, utilizing understudied sources for novel antimicrobials or antivirulence agents can provide new advances against antimicrobial resistant pathogens. In this study, we aimed to investigate antibacterial and antibiofilm activities of Posidonia oceanica (L.) Delile against Enterococcus faecalis ATCC 29212, Staphylococcus aureus ATCC 25923, Escherichia coli ATCC 25922 and Klebsiella pneumoniae ATCC 700603 and several S. aureus clinical isolates obtained from medical devices, including patient urinary catheters and breast implant infections, with varying antibiotic recalcitrance profiles. The ethanolic and methanolic extracts from P. oceanica rhizome exhibited significant antibacterial activity against E. faecalis and S. aureus, as well as drug resistant S. aureus clinical isolates. Furthermore, significant antibiofilm activity was observed against S. aureus and E. faecalis treated with ER, MR1, and MR2. P. oceanica extracts also exhibited synergistic antimicrobial activity with ciprofloxacin against E. faecalis, sensitizing E. faecalis to a lower ciprofloxacin concentration. Collectively, our data demonstrate the selective antibacterial and antibiofilm activity of the extracts of P. oceanica against Gram-positive bacteria and clinical isolates along with potentiation of current antibiotics, which suggests that P. oceanica can be further investigated as a potential source for novel therapeutic options in the treatment of drug resistant bacterial infections.

Usefulness of dalbavancin in early discharge and nonhospitalization. It's time to throw your heart over the obstacle?

Dalbavancin is a semisynthetic lipoglycopeptide long-acting antibiotic approved for the treatment of acute bacterial skin and skin structure infections (ABSSSIs). Its features can be useful in the current healthcare scenario characterized by the shortage of available hospital beds. We implemented several actions in order to optimize the use of dalbavancin allowing an improvement strategy both from the healthcare system and the patient's perspective in two hospital settings. In the Emergency Department we hospitalized only patients who met the clinical criteria and not the logistic criteria (i.e., the need for antibiotic therapy infusion). During the years 2017-2023, this strategy was applied in 40 cases, thus avoiding 40 hospitalizations for a total saving of 280 days of hospitalization.In the Internal Medicine ward and surgery department when there was no longer any need for hospitalization, we discharged the patient as early as possible. During the years 2017-2023, this strategy was applied in 189 cases, saving at least 1,134 days of hospitalization. The outcome of the treated patients was favorable in 228 out of 229 patients (99.5%). Our experience using dalbavancin in ABSSSI has been very satisfactory overall. The efficacy was close to 100%. Minor adverse events of slight severity occurred rarely. At the same time, this strategy allowed a more efficient allocation of hospital beds. Dalbavancin presents an ideal pharmacodynamic/pharmacokinetic profile for the management of ABSSSI especially in settings where shortage of hospital beds is critical.

ABD-3, the confluence of powerful antibacterial modalities: ABDs delivering and expressing lss, the gene encoding lysostaphin.

In response to the antimicrobial resistance crisis, we have developed a powerful and versatile therapeutic platform, the Antibacterial Drone (ABD) system. The ABD consists of a highly mobile staphylococcal pathogenicity island re-purposed to deliver genes encoding antibacterial proteins. The chromosomally located island is induced by a co-resident helper phage, packaged in phage-like particles, and released in very high numbers upon phage-induced lysis. ABD particles specifically adsorb to bacteria causing an infection and deliver their DNA to these bacteria, where the bactericidal cargo genes are expressed, kill the bacteria, and cure the infection. Here, we report a major advance of the system, incorporation of the gene encoding a secreted, bactericidal, species-specific lytic enzyme, lysostsphin. This ABD not only kills the bacterium that has been attacked by the ABD, but also any surrounding bacteria that are sensitive to the lytic enzyme which is released by secretion and by lysis of the doomed cell. So while the killing field is thus expanded, there are no civilian casualties (bacteria that are insensitive to the ABD and its cargo protein(s) are not inadvertently killed). Without amplifying the number of ABD particles (which are not re-packaged), the expression and release of the cargo gene's product dramatically extend the effective reach of the ABD. A cargo gene that encodes a secreted bactericidal protein also enables the treatment of a mixed bacterial infection in which one of the infecting organisms is insensitive to the ABD delivery system but is sensitive to the ABD's secreted cargo protein.

Neutrophil Extracellular Traps-Inspired Bismuth-Based Polypeptide Nanonets for Synergetic Treatment of Bacterial Infections.

Excessive use of antibiotics and the formation of bacterial biofilms can lead to persistent infections caused by drug-resistant bacteria, rendering ineffective immune responses and even life-threatening. There is an urgent need to explore synergistic antibacterial therapies across all stages of infection. Drawing inspiration from the antibacterial properties of neutrophil extracellular traps (NETs) and integrating the bacterial biofilm dispersal mechanism involving boronic acid-catechol interaction, the multifunctional bismuth-based polypeptide nanonets (PLBA-Bi-Fe-TA) are developed. These nanonets are designed to capture bacteria through a coordination complex involving cationic polypeptides (PLBA) with boronic acid-functionalized side chains, alongside metal ions (bismuth (Bi) and iron (Fe)), and tannic acid (TA). Leveraging the nanoconfinement-enhanced high-contact network-driven multiple efficiency, PLBA-Bi-Fe-TA demonstrates the excellent ability to swiftly capture bacteria and their extracellular polysaccharides. This interaction culminates in the formation of a highly hydrophilic complex, effectively enabling the rapid inhibition and dispersion of antibiotic-resistant bacterial biofilms, while Fe-TA shows mild photothermal ability to further assist fluffy mature biofilm. In addition, Bi is beneficial to regulate the polarization of macrophages to pro-inflammatory phenotype to further kill escaping biofilm bacteria. In summary, this novel approach offers a promising bionic optimization strategy for treating bacterial-associated infections at all stages through synergetic treatment.

Gallic acid exerts antibiofilm activity by inhibiting methicillin-resistant Staphylococcus aureus adhesion

Methicillin-resistant Staphylococcus aureus (MRSA) is a serious threat to patients with nosocomial infections, and infection is strongly associated with biofilm formation. Gallic acid (GA) is a natural bioactive compound found in traditional Chinese medicines that exerts potent antimicrobial activity. However, the anti-MRSA biofilm efficacy of GA remained to be determined. This study investigated the antimicrobial activities of GA against MRSA and the mechanisms involved. The results revealed the significant antibacterial and antibiofilm activities of GA. The minimal inhibitory concentration of GA against MRSA was 32 μg/mL and a growth curve assay confirmed the significant inhibitory effect of GA on planktonic MRSA. Crystal violet and XTT assays showed that 8 µg/mL GA effectively inhibited the formation of new biofilms and disrupted existing biofilms by reducing both biofilm biomass and metabolic activities. Alkaline phosphatase and β-galactosidase leakage assays and live/dead staining provided evidence that GA disrupted the integrity of bacterial cell walls and membranes within the biofilm. Scanning electron microscopy observations showed that GA significantly inhibited bacterial adhesion and aggregation, affecting the overall structure of the biofilm. Bacterial adhesion, polysaccharide intercellular adhesion (PIA) production and real-time quantitative PCR assay confirmed that GA inhibited bacterial adhesion, PIA synthesis, and the expression of icaAD and sarA. These results suggested that GA inhibited biofilm formation by inhibiting the expression of sarA, then downregulating the expression of icaA and icaD, thereby reducing the synthesis of PIA to attenuate the adhesion capacity of MRSA. GA is therefore a promising candidate for development as a pharmaceutical agent for the prevention and treatment of bacterial infections caused by MRSA.

Recent Progress in Multifunctional Stimuli-Responsive Combinational Drug Delivery Systems for the Treatment of Biofilm-Forming Bacterial Infections

Recent Progress in Multifunctional Stimuli-Responsive Combinational Drug Delivery Systems for the Treatment of Biofilm-Forming Bacterial Infections

Prevalence and patterns of multidrug-resistant bacteria isolated from sputum samples of patients with bacterial pneumonia at a tertiary hospital in Tanzania

BackgroundAntimicrobial resistance affects the treatment of several bacterial infections, including pneumonia. This subsequently increased the morbidity and mortality rates of patients with bacterial pneumonia, especially in resource-limited settings. In this study, we aimed to determine the patterns of multidrug-resistant (MDR) bacteria isolated from the sputum samples of patients with bacterial pneumonia attending a tertiary hospital in Tanzania.MethodologyA retrospective cross-sectional study was conducted. It involved reviewing the laboratory sputum data in the laboratory information system at Muhimbili National Hospital in Tanzania. The sputum samples were previously processed using standard methods (culture, Gram staining, and biochemical tests) to isolate and identify the bacteria. At the same time, antibiogram profiles were determined using antimicrobial susceptibility tests. Bacterial isolates that expressed MDR patterns were identified. Demographic information was collected from patients' medical records. We used the chi-square test to determine factors associated with MDR. A p-value < 0.05 was considered significant.ResultsWe retrieved and analysed 169 laboratory records of patients with a provisional clinical diagnosis of bacterial pneumonia confirmed in the microbiology laboratory. Nearly 98% of the records were from adult patients. The patients’ mean age was 48.3 years and 17.3 standard deviations. About 84% of the isolated bacteria were Gram-negative; the most predominant was Klebsiella pneumoniae (59/142; 41.5%). The predominant Gram-positive bacteria was Staphylococcus aureus (25/27; 92.6%). Furthermore, 80 out of 169 (47.3%) bacteria were MDR; Klebsiella pneumoniae (32.5%) was predominant. In addition, 50% of Staphylococcus aureus was methicillin resistance. MDR bacterial pneumonia was highly observed in patients admitted to the Intensive Care Unit (p < 0.05).ConclusionsAlthough our study was limited by variations in the number of bacterial isolates subjected to the same antibiotic drugs and a lack of information on risk factors such as occupation, smoking history, and marital status, we observed that a high proportion of bacterial pneumonia is caused by MDR Gram-negative bacteria in our local setting. These results inform the need to improve infection prevention control measures in hospitals to reduce the burden of MDR bacteria in our settings and other similar resource-limited settings.

Penicillin concentrations in oropharyngeal and frontal sinus tissue following enteral and intravenous administration measured by microdialysis in a porcine model

BackgroundPenicillin may be administered enterally or intravenously for the treatment of bacterial infections within the oropharynx and the frontal sinuses. We aimed to assess and compare penicillin concentrations in oropharyngeal and frontal sinus tissues following enteral and intravenous administration in a porcine model. MethodTwelve pigs were randomized to receive either enteral (0.8 g Penicillin V) or intravenous (1.2 g Penicillin G) penicillin. Microdialysis was used for sampling in oropharyngeal and frontal sinus tissues during a six-hour dosing interval. In addition, plasma samples were collected. The primary endpoints were time with drug concentration above the minimal inhibitory concentration (T>MIC) for two MIC targets: 0.125 (low target) and 0.5 (high target) μg/mL (covering Group A Streptococci, Fusobactarium necrophorum, Streptococcus pneumoniae and Hemophilus influenza) and attainment of these treatment targets for ≥50 % T>MIC. ResultsFor both the low and high MIC targets, intravenous administration resulted in higher T>MIC in oropharyngeal and frontal sinus tissues compared to enteral administration. In oropharyngeal tissue, the treatment target (≥50 % T>MIC) was achieved for both the low target (96 %) and high target (68 %) when penicillin was administrated intravenously. In frontal sinus tissue, the treatment target was reached for the low target (70 %), but not the high target (35 %) when administered intravenously. None of the two tissues reached the treatment targets when penicillin was administered enterally. ConclusionIntravenous administrated penicillin in standard dosage is superior to enteral administration of penicillin in standard dosage in achieving clinically important T>MIC as the majority of targets were achieved following intravenously administration, while none of the targets were achieved following enteral administration. These results support the general notion of higher tissue concentrations following intravenous compared to enteral administration.

Designing Fast-Moving Antibacterial Microtorpedoes to Treat Lethal Bacterial Biofilm Infections.

Engineering fast-moving microrobot swarms that can physically disassemble bacterial biofilms and kill the bacteria released from the biofilms is a promising way to combat bacterial biofilm infections. Here, we report electrochemical design of Ag7O8NO3 microtorpedoes with outstanding antibacterial performance and meanwhile capable of moving at speeds of hundreds of body lengths per second in clinically used H2O2 aqueous solutions. These fast-moving antibacterial Ag7O8NO3 microtorpedoes could penetrate into and disintegrate the bacterial biofilms and, in turn, kill the bacteria released from the biofilms. Based on the understanding of the growth behavior of the microtorpedoes, we could fine-tune the morphology of the microtorpedoes to accelerate the moving speed and increase their penetration depth into the biofilms simply via controlling the potential waveforms. We further developed an automatic shaking method to selectively peel off the uniformly structured microtorpedoes from the electrode surface, realizing continuous electrochemical production of the microtorpedoes. Animal experiments proved that the microtorpedo swarms greatly increased the survival rate of the mice infected by lethal biofilms to >90%. We used the electrochemical method to design and massively produce uniformly structured fast-moving antibacterial microtorpedo swarms with application potentials in treatment of lethal bacterial biofilm infections.

Exploring essential oil-based bio-composites: molecular docking and in vitro analysis for oral bacterial biofilm inhibition.

Oral bacterial biofilms are the main reason for the progression of resistance to antimicrobial agents that may lead to severe conditions, including periodontitis and gingivitis. Essential oil-based nanocomposites can be a promising treatment option. We investigated cardamom, cinnamon, and clove essential oils for their potential in the treatment of oral bacterial infections using in vitro and computational tools. A detailed analysis of the drug-likeness and physicochemical properties of all constituents was performed. Molecular docking studies revealed that the binding free energy of a Carbopol 940 and eugenol complex was -2.0kcal/mol, of a Carbopol 940-anisaldehyde complex was -1.9kcal/mol, and a Carbapol 940-eugenol-anisaldehyde complex was -3.4kcal/mol. Molecular docking was performed against transcriptional regulator genes 2XCT, 1JIJ, 2Q0P, 4M81, and 3QPI. Eugenol cinnamaldehyde and cineol presented strong interaction with targets. The essential oils were analyzed against Staphylococcus aureus and Staphylococcus epidermidis isolated from the oral cavity of diabetic patients. The cinnamon and clove essential oil combination presented significant minimum inhibitory concentrations (MICs) (0.0625/0.0312mg/mL) against S. epidermidis and S. aureus (0.0156/0.0078mg/mL). In the anti-quorum sensing activity, the cinnamon and clove oil combination presented moderate inhibition (8mm) against Chromobacterium voilaceum with substantial violacein inhibition (58% ± 1.2%). Likewise, a significant biofilm inhibition was recorded in the case of S. aureus (82.1% ± 0.21%) and S. epidermidis (84.2% ± 1.3%) in combination. It was concluded that a clove and cinnamon essential oil-based formulation could be employed to prepare a stable nanocomposite, and Carbapol 940 could be used as a compatible biopolymer.

Characterization of the novel broad-spectrum lytic phage Phage_Pae01 and its antibiofilm efficacy against Pseudomonas aeruginosa.

Pseudomonas aeruginosa is present throughout nature and is a common opportunistic pathogen in the human body. Carbapenem antibiotics are typically utilized as a last resort in the clinical treatment of multidrug-resistant infections caused by P. aeruginosa. The increase in carbapenem-resistant P. aeruginosa poses an immense challenge for the treatment of these infections. Bacteriophages have the potential to be used as antimicrobial agents for treating antibiotic-resistant bacteria. In this study, a new virulent P. aeruginosa phage, Phage_Pae01, was isolated from hospital sewage and shown to have broad-spectrum antibacterial activity against clinical P. aeruginosa isolates (83.6%). These clinical strains included multidrug-resistant P. aeruginosa and carbapenem-resistant P. aeruginosa. Transmission electron microscopy revealed that the phage possessed an icosahedral head of approximately 80 nm and a long tail about 110 m, indicating that it belongs to the Myoviridae family of the order Caudovirales. Biological characteristic analysis revealed that Phage_Pae01 could maintain stable activity in the temperature range of 4~ 60°C and pH range of 4 ~ 10. According to the in vitro lysis kinetics of the phage, Phage_Pae01 demonstrated strong antibacterial activity. The optimal multiplicity of infection was 0.01. The genome of Phage_Pae01 has a total length of 93,182 bp and contains 176 open reading frames (ORFs). The phage genome does not contain genes related to virulence or antibiotic resistance. In addition, Phage_Pae01 effectively prevented the formation of biofilms and eliminated established biofilms. When Phage_Pae01 was combined with gentamicin, it significantly disrupted established P. aeruginosa biofilms. We identified a novel P. aeruginosa phage and demonstrated its effective antimicrobial properties against P. aeruginosa in both the floating and biofilm states. These findings offer a promising approach for the treatment of drug-resistant bacterial infections in clinical settings.

A Comprehensive Review on Analytical Methods of Rifampicin

Rifampicin, a cornerstone in the treatment of tuberculosis and other bacterial infections, necessitates robust analytical methods for its accurate determination in pharmaceutical formulations and biological matrices. This review aims to provide a comprehensive summary of the analytical methods developed and validated for rifampicin quantification, encompassing various chromatographic, spectroscopic, and other analytical techniques reported in the literature. The review begins with an overview of the physicochemical properties, pharmacological significance, and regulatory requirements pertinent to rifampicin analysis. Additionally, the review highlights the importance of method robustness, specificity, sensitivity, and stability-indicating capability in ensuring the quality and safety of rifampicin-containing formulations. Overall, this review serves as a comprehensive reference for researchers, analysts, and regulatory authorities involved in the development, validation, and quality control of analytical methods for rifampicin, facilitating the advancement of pharmaceutical sciences and therapeutic interventions aimed at combating infectious diseases effectively

Light‐activated Nanocatalyst for Precise In‐situ Antimicrobial Synthesis via Photoredox‐Catalytic Click Reaction

The excessive and prolonged use of antibiotics contributes to the emergence of drug‐resistant S. aureus strains and potential dysbacteriosis‐related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light‐activated nanocatalyst for synthesizing in‐situ antimicrobials through photoredox‐catalytic click reaction, achieving precise, site‐directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the CuII‐based metal‐organic framework, MOF‐199, and further enveloped with Pluronic F‐127 to create the light‐responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox‐catalytic cycle, driven by the 1,3,5‐benzenetricarboxylic carboxylate salts (BTC−) ligand presented in the structure of MOF‐199. This light‐activated MB then catalyzes the reduction of CuII to CuI through a single‐electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF‐catalyzed drug synthesis in inhibiting S. aureus, including their methicillin‐resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on‐site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects.

Light-activated Nanocatalyst for Precise In-situ Antimicrobial Synthesis via Photoredox-Catalytic Click Reaction.

The excessive and prolonged use of antibiotics contributes to the emergence of drug-resistant S. aureus strains and potential dysbacteriosis-related diseases, necessitating the exploration of alternative therapeutic approaches. Herein, we present a light-activated nanocatalyst for synthesizing in-situ antimicrobials through photoredox-catalytic click reaction, achieving precise, site-directed elimination of S. aureus skin infections. Methylene blue (MB), a commercially available photosensitizer, was encapsulated within the CuII-based metal-organic framework, MOF-199, and further enveloped with Pluronic F-127 to create the light-responsive nanocatalyst MB@PMOF. Upon exposure to red light, MB participates in a photoredox-catalytic cycle, driven by the 1,3,5-benzenetricarboxylic carboxylate salts (BTC-) ligand presented in the structure of MOF-199. This light-activated MB then catalyzes the reduction of CuII to CuI through a single-electron transfer (SET) process, efficiently initiating the click reaction to form active antimicrobial agents under physiological conditions. Both in vitro and in vivo results demonstrated the effectiveness of MB@PMOF-catalyzed drug synthesis in inhibiting S. aureus, including their methicillin-resistant strains, thereby accelerating skin healing in severe bacterial infections. This study introduces a novel design paradigm for controlled, on-site drug synthesis, offering a promising alternative to realize precise treatment of bacterial infections without undesirable side effects.

Photoresponsive Multirole Nanoweapon Camouflaged by Hybrid Cell Membrane Vesicles for Efficient Antibacterial Therapy of Pseudomonas aeruginosa-Infected Pneumonia and Wound.

Exploring effective antibacterial approaches for targeted treatment of pathogenic bacterial infections with reduced drug resistance is of great significance. Combinational treatment modality that leverages different therapeutic components can improve the overall effectiveness and minimize adverse effects, thus displaying considerable potential against bacterial infections. Herein, red blood cell membrane fuses with macrophage membrane to develop hybrid cell membrane shell, which further camouflages around drug-loaded liposome to fabricate biomimetic liposome (AB@LRM) for precise antibacterial therapy. Specifically, photoactive agent black phosphorus quantum dots (BPQDs) and classical antibiotics amikacin (AM) are loaded in AB@LRM to accurately target the inflammatory sites through the guidance of macrophage membrane and long residence capability of red blood cell membrane, eventually exerting efficacious antibacterial activities. Besides, due to the excellent photothermal and photodynamic properties, BPQDs act as an efficient antibacterial agent when exposed to near-infrared laser irradiation, dramatically increasing the sensitivity of bacteria to antibiotics. Consequently, the synergistic sterilizing effect produced by AB@LRM further restricts bacterial resistance. Upon laser irradiation, AB@LRM shows superior anti-inflammatory and antibacterial properties in models of P. aeruginosa-infected pneumonia and wounds. Hence, this light-activatable antibacterial nanoplatform with good biocompatibility presents great potential to advance the clinical development in the treatment of bacterial infections.

Antimicrobial Potential of Aqueous and Ethanol Extract of Termite and Bee Natural Products on Escherichia coli for Possible Medicinal Purpose

Background: arthropods have been utilized for their socio-economic value as food and medicine for decades in most part of the world. Many traditional healers use insects in their traditional medicine healing system. The idea of utilizing substances collected from insects as medicinal resources, might have originated from the chemical compounds (such as pheromones, venoms, and toxins) sequestered from plants that have shown medicinal value. The study was targeted at investigating the antimicrobial potential of termite and bee natural products on Escherichia coli for possible medicinal purpose. The insects were collected from farmlands (using different insect traps) within Agulu and Nanka communities, Anambra State, Nigeria. The sample was identified and authenticated at the Zoology Department. The insect were killed using killing jar technique, air dried, pulverized and macerated for further investigation. The zoochemical properties and antimicrobial activity of the extract was investigated. Results: It was observed that the constituents, carbohydrate and saponins were present in all the extracts. Tannins, Flavonoids and Terpenoids were present in the ethanol extracts of both insects. The other zoochemicals investigated: Anthraquinones. Alkaloids, Cardiac glycoside, and steroids were not observed in all of the extracts. The water extract of both bee and termite exhibited less activity against E. coli. The ethanol extract of both insects showed E. coli growth inhibition. Based on the distinct zones of inhibition observed. The ethanol extract of termite showed higher inhibition activity (8.33 ± 0.60 mm zone of inhibition), this was followed by the ethanol extract of bee (7.08 ± 1.18 mm zone of inhibition). The aqueous (water) extract of termite (1.33 ± 0.67 mm zone of inhibition) showed higher activity than that of the bee extract (1.00 ± 0.58 mm zone of inhibition). Conclusion: The result of the study showed that ethanol extract of termite and bee contain bioactive constituents with antibacterial effect and lends credence to the entomo-ethno medicinal use of insect in the treatment of bacterial infections.

Nordalbergin Synergizes with Novel β-Lactam Antibiotics against MRSA Infection.

The synergetic strategy has created tremendous advantages in drug-resistance bacterial infection treatment, whereas challenges related to novel compound discovery and identifying drug-binding targets still remain. The mechanisms of antimicrobial resistance involving β-lactamase catalysis and the degradation of β-lactam antibiotics are being revealed, with relevant therapies promising to improve the efficacy of existing major classes of antibiotics in the foreseeable future. In this study, it is demonstrated that nordalbergin, a coumarin isolated from the wood bark of Dalbergia sissoo, efficiently potentiated the activities of β-lactam antibiotics against methicillin-resistant Staphylococcus aureus (MRSA) by suppressing β-lactamase performance and improving the bacterial biofilm susceptibility to antibiotics. Nordalbergin was found to destabilize the cell membrane and promote its permeabilization. Moreover, nordalbergin efficiently improved the therapeutic efficacy of amoxicillin against MRSA pneumonia in mice, as supported by the lower bacterial load, attenuated pathological damage, and decreased inflammation level. These results demonstrate that nordalbergin might be a promising synergist of amoxicillin against MRSA infections. This study provided a new approach for developing potentiators for β-lactam antibiotics against MRSA infections.

Antibacterial Mechanism of d-Cysteine/Polyethylene Glycol-Functionalized Gold Nanoparticles and Their Potential for the Treatment of Bacterial Infections.

Bacterial infection has always posed a severe threat to public health. Gold nanoparticles (Au NPs) exhibit exceptional biocompatibility and hold immense potential in biomedical applications. However, their antibacterial effectiveness is currently unsatisfactory. Herein, a chiral antibacterial agent with high stability was prepared by the modification of Au NPs with d-cysteine with the assistance of polyethylene glycol (PEG). The as-synthesized d-cysteine/PEG-Au NPs (D/P-Au NPs) exhibited a stronger (99.5-99.9%) and more stable (at least 14 days) antibacterial performance against Gram-negative (Escherichia coli and Listeria monocytogenes) and Gram-positive (Salmonella enteritidis and Staphylococcus aureus) bacteria, compared with other groups. The analysis of the antibacterial mechanism revealed that the D/P-Au NPs mainly affected the assembly of ribosomes, the biosynthesis of amino acids and proteins, as well as the DNA replication and mismatch repair, ultimately leading to bacterial death, which is significantly different from the mechanism of reactive oxygen species-activated metallic antibacterial NPs. In particular, the D/P-Au NPs were shown to effectively accelerate the healing of S. aureus-infected wounds in mice to a rate comparable to or slightly higher than that of vancomycin. This work provides a novel approach to effectively design chiral antibacterial agents for bacterial infection treatment.