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Acta Biomaterialia Jun 2024Antimicrobial phototherapy has gained recognition as a promising approach for addressing bacterial biofilms, however, its effectiveness is often impeded by the robust...
Antimicrobial phototherapy has gained recognition as a promising approach for addressing bacterial biofilms, however, its effectiveness is often impeded by the robust physical and chemical defenses of the biofilms. Traditional antibacterial nanoplatforms face challenges in breaching the extracellular polymeric substances (EPS) barrier to efficiently deliver photosensitizers deep into biofilms. Moreover, the prevalent hypoxia within biofilms restricts the success of oxygen-reliant phototherapy. In this study, we engineered a soft mesoporous organosilica nanoplatform (SMONs) by incorporating polyethylene glycol (PEG), catalase (CAT), and indocyanine green (ICG), forming SMONs-PEG-CAT-ICG (SPCI). We compared the antimicrobial efficacy of SPCI with more rigid nanoplatforms. Our results demonstrate that SPCI's unique flexible mechanical properties enable it to navigate through biofilm barriers, markedly enhancing ICG penetration in methicillin-resistant Staphylococcus aureus (MRSA) biofilms. Notably, in a murine subcutaneous MRSA biofilm infection model, SPCI showed superior biofilm penetration and pharmacokinetic benefits over its rigid counterparts. The embedded catalase in SPCI effectively converts excess HO present in infected tissues into O, alleviating hypoxia and significantly boosting the antibacterial performance of phototherapy. Both in vitro and in vivo experiments confirm that SPCI surpasses traditional rigid nanoplatforms in overcoming biofilm barriers, offering improved treatment outcomes for infections associated with bacterial biofilms. This study presents a viable strategy for managing bacterial biofilm-induced diseases by leveraging the unique attributes of a soft mesoporous organosilica-based nanoplatform. STATEMENT OF SIGNIFICANCE: This research introduces an innovative antimicrobial phototherapy soft nanoplatform that overcomes the inherent limitations posed by the protective barriers of bacterial biofilms. By soft nanoplatform with flexible mechanical properties, we enhance the penetration and delivery of photosensitizers into biofilms. The inclusion of catalase within this soft nanoplatform addresses the hypoxia in biofilms by converting hydrogen peroxide into oxygen in infected tissues, thereby amplifying the antibacterial effectiveness of phototherapy. Compared to traditional rigid nanoplatforms, this flexible nanoplatform not only promotes the delivery of therapeutic agents but also sets a new direction for treating bacterial biofilm infections, offering significant implications for future antimicrobial therapies.
PubMed: 38897337
DOI: 10.1016/j.actbio.2024.06.018 -
Talanta Jun 2024Bovine mastitis is an inflammation of the mammary gland, and it is the most common infectious disease in dairy cattle. Mastitis reduces milk yield and quality, costing...
Bovine mastitis is an inflammation of the mammary gland, and it is the most common infectious disease in dairy cattle. Mastitis reduces milk yield and quality, costing dairy farmers millions of dollars each year. The aim of this study was to develop a point-of-need test for identifying mastitis pathogens that is field portable, cost-effective and can be used with minimal training. Using a proprietary polymer-based milk sample preparation method to rapidly extract pathogen DNA in milk samples, we demonstrated quantitative Polymerase Chain Reaction (qPCR) assays for six common bovine bacterial mastitis pathogens: Staphylococcus aureus, Streptococcus agalactiae, Streptococcus dysgalactiae, Streptococcus uberis, Mycoplasma bovis and Escherichia coli. We also implemented this sample preparation method on a prototype point-of-need system in a proof-of-concept field trial to evaluate user experience. Importantly, the protype system enabled a sample-to-result turnaround time of within 70 min to quantitatively detect all six target pathogens. The key advantage of our point-of-need prototype system is being culture-independent yet providing automated milk sample preparation for molecular identification of key mastitis pathogens by non-expert users. Our point-of-need prototype system showed a good correlation to laboratory-based qPCR for target pathogen detection outcomes, thus potentially removing the need for milk samples to be transported off-site for laboratory testing. Above all, we successfully achieved our objective of developing a point-of-need biosensor technology for mastitis and increased its readiness level with industry partners towards technology commercialization.
PubMed: 38897015
DOI: 10.1016/j.talanta.2024.126424 -
Veterinary Medicine and Science Jul 2024Bersama abyssinica Fresen is a plant that is used in folk medicine for the treatment of mastitis and other infectious diseases.
BACKGROUND
Bersama abyssinica Fresen is a plant that is used in folk medicine for the treatment of mastitis and other infectious diseases.
OBIECTIVE
The antibacterial activity of methanol crude extract of plant was evaluated against three common bacterial pathogens, including Gram positive (Staphylococcus aureus) and Gram negative (Escherichia coli and Pseudomonas aeruginosa).
METHODS
The antibacterial activities and minimum inhibitory concentration of B. abyssinica crude extracts were evaluated using agar-well diffusion and broth dilution methods according to the National Committee for Clinical Laboratory Standards (NCCLS).
RESULTS
A significant difference in the antibacterial activity of crude extracts was observed among different levels of concentration against tested isolates. A higher mean inhibition zone diameter was recorded in E. coli (29.2 ± 1.5 mm), followed by S. aureus (27.8 ± 1.1 mm) and P. aeruginosa (18.0 ± 0.7 mm) at a concentration of 100 mg/mL. The antibacterial activity of crude plant extract at 100 mg/mL was comparable with that of a standard antibiotic (27.6 ± 2.6) against S. aureus and E. coli isolates. The findings indicated that bacterial growth inhibition increased as the concentration of the crude extracts increased. E. coli and S. aureus isolates showed significantly higher susceptibilities to crude extracts than P. aeruginosa at all concentrations. The minimum inhibitory concentrations of extracts against S. aureus, E. coli and P. aeruginosa isolates were 0.78 mg/mL, 1.56 mg/mL and 1.56 mg/mL, respectively.
CONCLUSIONS
All tested pathogenic bacterial species were susceptible to plant leaf extract and broad-spectrum activity against Gram-positive and Gram-negative bacteria. The study recommends further fractionation of the B. abyssinica plant that contributes to its antibacterial activity and understands the mode of action of this plant against bacteria and other microbes.
Topics: Plant Extracts; Anti-Bacterial Agents; Microbial Sensitivity Tests; Gram-Negative Bacteria; Gram-Positive Bacteria; Escherichia coli; Staphylococcus aureus; Pseudomonas aeruginosa
PubMed: 38896065
DOI: 10.1002/vms3.1498 -
Frontiers in Pharmacology 2024We sought to evaluate the pharmacodynamics of β-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens.
OBJECTIVES
We sought to evaluate the pharmacodynamics of β-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens.
METHODS
Two isolates, two isolates, and three isolates with varying β-lactamase production were evaluated in static time-killing experiments. Each gram-positive isolate was exposed to a concentration array of ampicillin () or cefazolin () alone and during co-culture with an isolate that was β-lactamase-deficient, produced TEM-1, or produced KPC-3/TEM-1B. The results of the time-killing experiments were summarized using an integrated pharmacokinetic/pharmacodynamics analysis as well as mathematical modelling to fully characterize the antibacterial pharmacodynamics.
RESULTS
In the integrated analysis, the maximum killing of ampicillin (E) against both isolates was ≥ 4.11 during monoculture experiments or co-culture with β-lactamase-deficient , whereas the E was reduced to ≤ 1.54 during co-culture with β-lactamase-producing . In comparison to monoculture experiments, culturing with KPC-producing resulted in reductions of the cefazolin E from 3.25 and 3.71 down to 2.02 and 2.98, respectively. Two mathematical models were created to describe the interactions between and either or . When in co-culture with , experienced a reduction in its cefazolin K by 24.8% (23.1%RSE). Similarly, β-lactamase-producing preferentially protected the ampicillin-resistant subpopulation, reducing K by 90.1% (14%RSE).
DISCUSSION
β-lactamase-producing were capable of protecting and from exposure to β-lactam antibacterials.
PubMed: 38895629
DOI: 10.3389/fphar.2024.1339858 -
BioRxiv : the Preprint Server For... Jun 2024Antimicrobial resistance (AMR) poses a critical threat to hospital infections particularly in the context of hospital-acquired infections (HAIs). This study leverages...
UNLABELLED
Antimicrobial resistance (AMR) poses a critical threat to hospital infections particularly in the context of hospital-acquired infections (HAIs). This study leverages genomic tools to predict AMR and identify resistance markers in clinical bacterial samples associated with HAIs. Using comprehensive genomic and phenotypic analyses, we evaluated the genetic profiles of Pseudomonas aeruginosa and Staphylococcus aureus to uncover resistance mechanisms. Our results demonstrate that genomic tools, such as CARD-RGI and the Solu platform, can accurately identify resistance genes and predict AMR phenotypes in nosocomial pathogens. These findings underscore the potential of integrating genomic approaches into clinical practice to enhance the management of resistant infections in hospital settings and inform the development of novel antimicrobial strategies.
IMPORTANCE
This study investigates the impact of prophages on antibiotic resistance in two clinically significant bacteria, Pseudomonas aeruginosa and Staphylococcus aureus. Understanding how prophages influence resistance mechanisms in these pathogens is crucial, as Pseudomonas aeruginosa is known for its role in chronic infections in cystic fibrosis patients, while Staphylococcus aureus, including MRSA strains, is a leading cause of hospital-acquired infections. By exploring the relationship between prophage presence and resistance, this research provides insights that could inform the development of more effective treatment strategies and enhance our ability to combat antibiotic-resistant infections, ultimately improving patient outcomes and public health.
PubMed: 38895396
DOI: 10.1101/2024.06.02.595912 -
Frontiers in Pediatrics 2024infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on...
BACKGROUND
infections are a significant cause of morbidity and mortality in pediatric populations worldwide. The Staphylo Research Network conducted an extensive study on pediatric patients across Colombia from 2018 to 2021. The aim of this study was to describe the epidemiological and microbiological characteristics of in this patient group.
METHODS
We analyzed isolates from WHONET-reporting centers. An "event" was a positive culture isolation in a previously negative individual after 2 weeks. We studied center characteristics, age distribution, infection type, and antibiotic susceptibilities, comparing methicillin sensitive (MSSA) and resistant (MRSA) isolates.
RESULTS
Isolates from 20 centers across 7 Colombian cities were included. Most centers (80%) served both adults and children, with 55% offering oncology services and 85% having a PICU. We registered 8,157 culture isolations from 5,384 events (3,345 MSSA and 1,961 MRSA) in 4,821 patients, with a median age of 5 years. Blood (26.2%) and skin/soft tissue (18.6%) were the most common infection sources. Most isolates per event remained susceptible to oxacillin (63.2%), clindamycin (94.3%), and TMP-SMX (98.3%). MRSA prevalence varied by city (<0.001), with slightly higher rates observed in exclusively pediatric hospitals. In contrast, the MRSA rate was somewhat lower in centers with Antimicrobial Stewardship Program (ASP). MRSA was predominantly isolated from osteoarticular infections and multiple foci, while MSSA was more frequently associated with recurrent infections compared to MRSA.
CONCLUSIONS
This is the largest study of pediatric infections in Colombia. We found MSSA predominance, but resistance have important regional variations. remains susceptible to other commonly used antibiotics such as TMP-SMX and clindamycin. Ongoing monitoring of infections is vital for understanding their behavior in children. Prospective studies within the Staphylored LATAM are underway for a more comprehensive clinical and genetic characterization.
PubMed: 38895192
DOI: 10.3389/fped.2024.1386310 -
Cureus May 2024Background and objective Urinary tract infections (UTIs) are a common infectious disease affecting people of various ages and genders and are prevalent in different...
The Prevalence of Multidrug-Resistant Uropathogenic Bacterial Profile With Antibiotic Susceptibility Patterns Among the Community and Hospitalized Patients During COVID Waves.
Background and objective Urinary tract infections (UTIs) are a common infectious disease affecting people of various ages and genders and are prevalent in different geographical locations. However, the way Gram-positive and Gram-negative (UTI) germs react to antibiotic treatment varies significantly. The coronavirus disease 2019 (COVID-19) pandemic has increased the frequency of secondary bacterial superinfection, leading to a spike in ongoing recommendations for antibiotic treatment, both therapeutic and preventative. In this study, we aimed to assess uropathogenic bacterial resistance and shed light on how COVID-19 epidemic waves influence the evolution of bacterial resistance. Materials and methods A cross-sectional study was conducted, assessing the different isolates of the uropathogen in all COVID-19 waves by using convenience sampling from August 2020 till the end of 2023. The VITEK-2 compact system employing industry-standard bacteriological tests to identify the bacteria and confirm their antibiotic susceptibility was utilized. Results Of the total 3877 patients, 381 (9.8%) and 3483 (89.8%) had positive and negative microbial growth, respectively. Of the 381 (9.8%) positive cases, 130 (34%) were male and 251 (65%) were female; 138 (43.3%) patients in the age range of 15-40 years developed sporadic UTIs attributed to Gram-negative bacteria. Alternatively, patients over 40 years had the highest prevalence rate (n = 180, 56.6%). The most common strains of Gram-negative and Gram-positive bacteria were and with278 (88.8%) and 13 (20.9%) cases respectively. People with Gram-negative bacteria who were not hospitalized were very resistant to trimethoprim/sulfamethoxazole (n = 219, 69.1%), cefotaxime (n = 193, 60.9%), ampicillin (n = 192, 60.6%), and amoxicillin/clavulanic acid (176, 55.5%). While high sensitivity to meropenem (n = 14, 4.4%) and imipenem (n = 13, 4.1%) was observed, hospitalized individuals had higher levels of resistance and great sensitivity to the same antibiotics. S. . were commonly present. Hospitalized patients were less sensitive to benzylpenicillin, ampicillin, and oxacillin, and there was a big rise in resistance to cefoxitin in the community. Conclusions In this study, Gram-negative germs among females were predominantly observed with extremely high multi-drug resistance (MDR). The most effective antibiotics against Gram-positive germs included linezolid, vancomycin, and nitrofurantin, while those against Gram-negative bacteria were meropenem and amikacin. Clinicians should be regularly updated and informed about antibiotic selection through routine monitoring of uropathogenic bacteria's susceptibility. Moreover, we recommend changes to the local antibiotic policy regarding the selection of UTIs; further multicentric and high-volume studies are required to gain deeper insights into the topic.
PubMed: 38894805
DOI: 10.7759/cureus.60613 -
Materials (Basel, Switzerland) Jun 2024In this study, a pH-responsive polycaprolactone (PCL)-copper peroxide (CuO) composite antibacterial coating was developed by suspension flame spraying. The successful...
In this study, a pH-responsive polycaprolactone (PCL)-copper peroxide (CuO) composite antibacterial coating was developed by suspension flame spraying. The successful synthesis of CuO nanoparticles and fabrication of the PCL-CuO composite coatings were confirmed by microstructural and chemical analysis. The composite coatings were structurally homogeneous, with the chemical properties of PCL well maintained. The acidic environment was found to effectively accelerate the dissociation of CuO, allowing the simultaneous release of Cu and HO. Antimicrobial tests clearly revealed the enhanced antibacterial properties of the PCL-CuO composite coating against both and under acidic conditions, with a bactericidal effect of over 99.99%. This study presents a promising approach for constructing pH-responsive antimicrobial coatings for biomedical applications.
PubMed: 38893930
DOI: 10.3390/ma17112666 -
Molecules (Basel, Switzerland) Jun 2024The adoption of green chemistry protocols in nanoparticle (NP) synthesis has exhibited substantial potential and is presently a central focus in research for generating...
The adoption of green chemistry protocols in nanoparticle (NP) synthesis has exhibited substantial potential and is presently a central focus in research for generating versatile NPs applicable across a broad spectrum of applications. In this scientific contribution, we, for the first time, examined the ability of () crude extract to synthesize silver and gold nanoparticles (AgNPs@AL; AuNP@AL) and explored their potential applications in biological activities and the catalytic degradation of environmental pollutants. The synthesized NPs exhibited a distinctive surface plasmon resonance pattern, a spherical morphology with approximate sizes of 5-10 nm (TEM imaging), a crystalline architecture (XRD analysis), and potential functional groups identified by FTIR spectroscopy. The antibacterial activity was demonstrated by inhibition zones that measured 16 and 14 mm for the AgNPs@AL and AuNP@AL at a concentration of 80 µg/mL against and 14 and 12 mm against , respectively. The antioxidant potential of the synthesized NPs was evaluated using 2,2-diphenyl-1-picrylhydrazyl (DPPH), 2-Phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl 3-Oxide (PTIO), and 3-ethylbenzothiazoline-6-sulfonic acid (ABTS) assays. Our findings suggest that the AuNP@AL effectively countered the tested radicals considerably, displaying IC values of 115.9, 103.54, and 180.85 µg/mL against DPPH, PTIO, and ABTS, respectively. In contrast, the AgNPs@AL showed IC values of 144.9, 116.36, and 95.39 µg/mL against the respective radicals. In addition, both the NPs presented significant effectiveness in the photocatalytic degradation of methylene blue and rhodamine B. The overall observations indicate that possesses a robust capability to synthesize spherical nanoparticles, exhibiting excellent dispersion and showcasing potential applications in both biological activities and environmental remediation.
Topics: Metal Nanoparticles; Silver; Gold; Plant Extracts; Aconitum; Anti-Bacterial Agents; Catalysis; Antioxidants; Microbial Sensitivity Tests; Staphylococcus aureus; Green Chemistry Technology; Escherichia coli
PubMed: 38893515
DOI: 10.3390/molecules29112640 -
Molecules (Basel, Switzerland) May 2024Isoflavones are a class of natural products that exhibit a wide range of interesting biological properties, including antioxidant, hepatoprotective, antimicrobial, and...
Isoflavones are a class of natural products that exhibit a wide range of interesting biological properties, including antioxidant, hepatoprotective, antimicrobial, and anti-inflammatory activities. Scandenone (), osajin (), and 6,8-diprenylgenistein () are natural prenylated isoflavones that share the same polyphenol framework. In this research, the key intermediate was used for the synthesis of the natural isoflavones -, establishing a stereoselective synthetic method for both linear and angular pyran isoflavones. The antibacterial activities of - were also evaluated, and all of them displayed good antibacterial activity against Gram-positive bacteria. Among them, was the most potent one against MRSA, with a MIC value of 2 μg/mL, and the SEM assay indicated that the bacterial cell membranes of both MRSA and could be disrupted by . These findings suggest that this type of isoflavone could serve as a lead for the development of novel antibacterial agents for the treatment of Gram-positive bacterial infections.
Topics: Anti-Bacterial Agents; Isoflavones; Microbial Sensitivity Tests; Molecular Structure; Methicillin-Resistant Staphylococcus aureus; Gram-Positive Bacteria; Biological Products; Enterococcus faecalis
PubMed: 38893450
DOI: 10.3390/molecules29112574