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1.
BMC Biotechnol ; 24(1): 28, 2024 May 04.
Article in English | MEDLINE | ID: mdl-38702622

ABSTRACT

Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV-vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200-6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.


Subject(s)
Biofilms , Catfishes , Metal Nanoparticles , Silver , Metal Nanoparticles/chemistry , Biofilms/drug effects , Biofilms/growth & development , Silver/chemistry , Silver/pharmacology , Animals , Humans , Mucus/metabolism , Antineoplastic Agents/pharmacology , Antineoplastic Agents/chemistry , Vero Cells , Fish Proteins/pharmacology , Fish Proteins/chemistry , Fish Proteins/metabolism , Chlorocebus aethiops , Cell Line, Tumor , Microbial Sensitivity Tests , Pseudomonas aeruginosa/drug effects , Anti-Infective Agents/pharmacology , Anti-Infective Agents/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Candida albicans/drug effects , Epidermis/metabolism
2.
BMC Microbiol ; 24(1): 152, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38702660

ABSTRACT

BACKGROUND: Pseudomonas aeruginosa is a common cause of nosocomial infections. However, the emergence of multidrug-resistant strains has complicated the treatment of P. aeruginosa infections. While polymyxins have been the mainstay for treatment, there is a global increase in resistance to these antibiotics. Therefore, our study aimed to determine the prevalence and molecular details of colistin resistance in P. aeruginosa clinical isolates collected between June 2019 and May 2023, as well as the genetic linkage of colistin-resistant P. aeruginosa isolates. RESULTS: The resistance rate to colistin was 9% (n = 18) among P. aeruginosa isolates. All 18 colistin-resistant isolates were biofilm producers and carried genes associated with biofilm formation. Furthermore, the presence of genes encoding efflux pumps, TCSs, and outer membrane porin was observed in all colistin-resistant P. aeruginosa strains, while the mcr-1 gene was not detected. Amino acid substitutions were identified only in the PmrB protein of multidrug- and colistin-resistant strains. The expression levels of mexA, mexC, mexE, mexY, phoP, and pmrA genes in the 18 colistin-resistant P. aeruginosa strains were as follows: 88.8%, 94.4%, 11.1%, 83.3%, 83.3%, and 38.8%, respectively. Additionally, down-regulation of the oprD gene was observed in 44.4% of colistin-resistant P. aeruginosa strains. CONCLUSION: This study reports the emergence of colistin resistance with various mechanisms among P. aeruginosa strains in Ardabil hospitals. We recommend avoiding unnecessary use of colistin to prevent potential future increases in colistin resistance.


Subject(s)
Anti-Bacterial Agents , Bacterial Proteins , Colistin , Microbial Sensitivity Tests , Pseudomonas Infections , Pseudomonas aeruginosa , Transcription Factors , Colistin/pharmacology , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Anti-Bacterial Agents/pharmacology , Humans , Bacterial Proteins/genetics , Pseudomonas Infections/microbiology , Pseudomonas Infections/epidemiology , Prevalence , Drug Resistance, Multiple, Bacterial/genetics , Biofilms/drug effects , Biofilms/growth & development , Hospitals , Drug Resistance, Bacterial/genetics , Cross Infection/microbiology , Cross Infection/epidemiology , Membrane Transport Proteins/genetics , Porins/genetics
3.
Int J Nanomedicine ; 19: 3861-3890, 2024.
Article in English | MEDLINE | ID: mdl-38708178

ABSTRACT

Introduction: Cystic fibrosis (CF) is associated with pulmonary Pseudomonas aeruginosa infections persistent to antibiotics. Methods: To eradicate pseudomonal biofilms, solid lipid nanoparticles (SLNs) loaded with quorum-sensing-inhibitor (QSI, disrupting bacterial crosstalk), coated with chitosan (CS, improving internalization) and immobilized with alginate lyase (AL, destroying alginate biofilms) were developed. Results: SLNs (140-205 nm) showed prolonged release of QSI with no sign of acute toxicity to A549 and Calu-3 cells. The CS coating improved uptake, whereas immobilized-AL ensured >1.5-fold higher uptake and doubled SLN diffusion across the artificial biofilm sputum model. Respirable microparticles comprising SLNs in carbohydrate matrix elicited aerodynamic diameters MMAD (3.54, 2.48 µm) and fine-particle-fraction FPF (65, 48%) for anionic and cationic SLNs, respectively. The antimicrobial and/or antibiofilm activity of SLNs was explored in Pseudomonas aeruginosa reference mucoid/nonmucoid strains as well as clinical isolates. The full growth inhibition of planktonic bacteria was dependent on SLN type, concentration, growth medium, and strain. OD measurements and live/dead staining proved that anionic SLNs efficiently ceased biofilm formation and eradicated established biofilms, whereas cationic SLNs unexpectedly promoted biofilm progression. AL immobilization increased biofilm vulnerability; instead, CS coating increased biofilm formation confirmed by 3D-time lapse confocal imaging. Incubation of SLNs with mature biofilms of P. aeruginosa isolates increased biofilm density by an average of 1.5-fold. CLSM further confirmed the binding and uptake of the labeled SLNs in P. aeruginosa biofilms. Considerable uptake of CS-coated SLNs in non-mucoid strains could be observed presumably due to interaction of chitosan with LPS glycolipids in the outer cell membrane of P. aeruginosa. Conclusion: The biofilm-destructive potential of QSI/SLNs/AL inhalation is promising for site-specific biofilm-targeted interventional CF therapy. Nevertheless, the intrinsic/extrinsic fundamentals of nanocarrier-biofilm interactions require further investigation.


Subject(s)
Anti-Bacterial Agents , Biofilms , Chitosan , Liposomes , Nanoparticles , Pseudomonas Infections , Pseudomonas aeruginosa , Biofilms/drug effects , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/physiology , Humans , Pseudomonas Infections/drug therapy , Nanoparticles/chemistry , Chitosan/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/pharmacokinetics , Drug Carriers/chemistry , Cystic Fibrosis/drug therapy , Cystic Fibrosis/microbiology , Lipids/chemistry , Lipids/pharmacology , Quorum Sensing/drug effects , A549 Cells , Alginates/chemistry
4.
J Biosci ; 492024.
Article in English | MEDLINE | ID: mdl-38726825

ABSTRACT

Bacterial species referred to as magnetotactic bacteria (MTB) biomineralize iron oxides and iron sulphides inside the cell. Bacteria can arrange themselves passively along geomagnetic field lines with the aid of these iron components known as magnetosomes. In this study, magnetosome nanoparticles, which were obtained from the taxonomically identified MTB isolate Providencia sp. PRB-1, were characterized and their antibacterial activity was evaluated. An in vitro test showed that magnetosome nanoparticles significantly inhibited the growth of Staphylococcus sp., Pseudomonas aeruginosa, and Klebsiella pneumoniae. Magnetosomes were found to contain cuboidal iron crystals with an average size of 42 nm measured by particle size analysis and scanning electron microscope analysis. The energy dispersive X-ray examination revealed that Fe and O were present in the extracted magnetosomes. The extracted magnetosome nanoparticles displayed maximum absorption at 260 nm in the UV-Vis spectrum. The distinct magnetite peak in the Fourier transform infrared (FTIR) spectroscopy spectra was observed at 574.75 cm-1. More research is needed into the intriguing prospect of biogenic magnetosome nanoparticles for antibacterial applications.


Subject(s)
Anti-Bacterial Agents , Magnetosomes , Providencia , Pseudomonas aeruginosa , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/isolation & purification , Pseudomonas aeruginosa/drug effects , Magnetosomes/chemistry , Magnetosomes/metabolism , Providencia/chemistry , Providencia/drug effects , Spectroscopy, Fourier Transform Infrared , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/growth & development , Nanoparticles/chemistry , Microbial Sensitivity Tests , Staphylococcus/drug effects , Staphylococcus/growth & development , Particle Size , Iron/chemistry , Iron/metabolism , Magnetite Nanoparticles/chemistry
5.
Biomed Environ Sci ; 37(4): 387-398, 2024 Apr 20.
Article in English | MEDLINE | ID: mdl-38727161

ABSTRACT

Objective: Recombinase-aided polymerase chain reaction (RAP) is a sensitive, single-tube, two-stage nucleic acid amplification method. This study aimed to develop an assay that can be used for the early diagnosis of three types of bacteremia caused by Staphylococcus aureus (SA), Pseudomonas aeruginosa (PA), and Acinetobacter baumannii (AB) in the bloodstream based on recombinant human mannan-binding lectin protein (M1 protein)-conjugated magnetic bead (M1 bead) enrichment of pathogens combined with RAP. Methods: Recombinant plasmids were used to evaluate the assay sensitivity. Common blood influenza bacteria were used for the specific detection. Simulated and clinical plasma samples were enriched with M1 beads and then subjected to multiple recombinase-aided PCR (M-RAP) and quantitative PCR (qPCR) assays. Kappa analysis was used to evaluate the consistency between the two assays. Results: The M-RAP method had sensitivity rates of 1, 10, and 1 copies/µL for the detection of SA, PA, and AB plasmids, respectively, without cross-reaction to other bacterial species. The M-RAP assay obtained results for < 10 CFU/mL pathogens in the blood within 4 h, with higher sensitivity than qPCR. M-RAP and qPCR for SA, PA, and AB yielded Kappa values of 0.839, 0.815, and 0.856, respectively ( P < 0.05). Conclusion: An M-RAP assay for SA, PA, and AB in blood samples utilizing M1 bead enrichment has been developed and can be potentially used for the early detection of bacteremia.


Subject(s)
Bacteremia , Mannose-Binding Lectin , Humans , Mannose-Binding Lectin/blood , Bacteremia/diagnosis , Bacteremia/microbiology , Bacteremia/blood , Recombinases/metabolism , Acinetobacter baumannii/genetics , Acinetobacter baumannii/isolation & purification , Staphylococcus aureus/isolation & purification , Staphylococcus aureus/genetics , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/genetics , Polymerase Chain Reaction/methods , Sensitivity and Specificity , Bacteria/genetics , Bacteria/isolation & purification
7.
PeerJ ; 12: e16708, 2024.
Article in English | MEDLINE | ID: mdl-38715984

ABSTRACT

The present work aimed at differentiating five Amaranthus species from Saudi Arabia according to their morphology and the ability in nanoparticle formulation. Biogenic silver nanoparticles (AgNPs) were synthesized from leaf extracts of the five Amaranthus species and characterized by different techniques. Fourier-transform infrared spectroscopy (FT-IR) was used to identify the phyto-constituents of Amaranthus species. The nanoparticles (NPs) were characterized by UV-visible spectroscopy, dynamic light scattering (DLS), transmission electron microscopy (TEM), and energy-dispersive X-ray spectroscopy (EDX). The antibacterial activity of the synthesized NPs was tested against Staphylococcus aureus, E. coli, Klebsiella pneumoniae and Pseudomonas aeruginosa using the agar well diffusion method. Spherical NPs varying in size and functional groups from the five plant species were demonstrated by TEM, DLS and FTIR analysis, respectively. Variations in NPs characteristics could be related to the phytochemical composition of each Amaranthus species since they play a significant role in the reduction process. EDX confirmed the presence of Ag in plant fabricated AgNPs. Antibacterial activity varied among the species, possibly related to the NPs characteristics. Varied characteristics for the obtained AgNPs may reflect variations in the phytochemical composition type and concentration among Amaranthus species used for their fabrication.


Subject(s)
Amaranthus , Anti-Bacterial Agents , Metal Nanoparticles , Microbial Sensitivity Tests , Plant Extracts , Silver , Amaranthus/chemistry , Metal Nanoparticles/chemistry , Silver/pharmacology , Silver/chemistry , Plant Extracts/pharmacology , Plant Extracts/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Spectroscopy, Fourier Transform Infrared , Humans , Pseudomonas aeruginosa/drug effects , Plant Leaves/chemistry , Escherichia coli/drug effects , Staphylococcus aureus/drug effects , Microscopy, Electron, Transmission , Saudi Arabia , Bacteria/drug effects , Klebsiella pneumoniae/drug effects
8.
Sci Rep ; 14(1): 10224, 2024 05 03.
Article in English | MEDLINE | ID: mdl-38702368

ABSTRACT

The biosynthesis of nanoparticles offers numerous advantages, including ease of production, cost-effectiveness, and environmental friendliness. In our research, we focused on the bioformation of silver nanoparticles (AgNPs) using a combination of Lactobacillus sp. and Bacillus sp. growth. These AgNPs were then evaluated for their biological activities against multidrug-resistant bacteria. Our study involved the isolation of Bacillus sp. from soil samples and Lactobacillus sp. from raw milk in Dhamar Governorate, Yemen. The synthesized AgNPs were characterized using various techniques such as UV-visible spectroscopy, X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and transmission electron microscopy (TEM). The antibacterial properties of the AgNPs were assessed using the modified Kirby Bauer disk diffusion method against multidrug-resistant strains of Staphylococcus aureus and Pseudomonas aeruginosa. Our results demonstrated that the use of a bacterial mixture for biosynthesis led to faster and more effective production of AgNPs compared to using a single bacterium. The UV-visible spectra showed characteristic peaks indicative of silver nanoparticles, while XRD analysis confirmed the crystalline nature of the synthesized particles. FTIR results suggested the presence of capping proteins that contribute to the synthesis and stability of AgNPs. Furthermore, TEM images revealed the size and morphology of the AgNPs, which exhibited spherical shapes with sizes ranging from 4.65 to 22.8 nm. Notably, the antibacterial activity of the AgNPs was found to be more pronounced against Staphylococcus aureus than Pseudomonas aeruginosa, indicating the potential of these nanoparticles as effective antimicrobial agents. Overall, our study highlights the promising antibacterial properties of AgNPs synthesized by a mixture of Lactobacillus sp. and Bacillus sp. growth. Further research is warranted to explore the potential of utilizing different bacterial combinations for enhanced nanoparticle synthesis.


Subject(s)
Anti-Bacterial Agents , Bacillus , Lactobacillus , Metal Nanoparticles , Microbial Sensitivity Tests , Silver , Metal Nanoparticles/chemistry , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Anti-Bacterial Agents/biosynthesis , Silver/chemistry , Silver/pharmacology , Bacillus/metabolism , Lactobacillus/metabolism , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/growth & development , Staphylococcus aureus/drug effects , Staphylococcus aureus/growth & development , Spectroscopy, Fourier Transform Infrared , X-Ray Diffraction
9.
Sci Rep ; 14(1): 10200, 2024 05 03.
Article in English | MEDLINE | ID: mdl-38702397

ABSTRACT

Today, antibiotic therapies that previously worked well against certain bacteria due to their natural sensitivity, are becoming less effective. Honey has been proven to inhibit the biofilm formation of some respiratory bacteria, however few data are available on how the storage time affects the antibacterial effect. The activity of black locust, goldenrod, linden and sunflower honeys from three consecutive years (2020, 2021, 2022) was analyzed in 2022 against Gram-negative (Haemophilus influenzae, H. parainfluenzae, Pseudomonas aeruginosa) and Gram-positive (Streptococcus pneumoniae) bacteria using in vitro microbiological methods. After determining the physicochemical parameters of honey, broth microdilution was applied to determine the minimum inhibitory concentration of each honey type against each bacterium, and crystal violet assay was used to test their antibiofilm effect. The possible mechanism of action was explored with membrane degradation test, while structural changes were illustrated with scanning electron microscopy. Honeys stored for one or two years were darker than fresh honeys, while older honeys had significantly lower antibacterial activity. The most remarkable inhibitory effect was exerted by linden and sunflower honeys, and P. aeruginosa proved to be the most resistant bacterium. Based on our results, honey intended for medicinal purposes should be used as fresh as possible during a treatment.


Subject(s)
Anti-Bacterial Agents , Honey , Microbial Sensitivity Tests , Honey/analysis , Anti-Bacterial Agents/pharmacology , Biofilms/drug effects , Biofilms/growth & development , Time Factors , Pseudomonas aeruginosa/drug effects , Food Storage/methods , Humans
10.
Front Cell Infect Microbiol ; 14: 1404960, 2024.
Article in English | MEDLINE | ID: mdl-38803574

ABSTRACT

Staphylococcus aureus and Staphylococcus epidermidis stand as notorious threats to human beings owing to the myriad of infections they cause. The bacteria readily form biofilms that help in withstanding the effects of antibiotics and the immune system. Intending to combat the biofilm formation and reduce the virulence of the pathogens, we investigated the effects of carotenoids, crocetin, and crocin, on four Staphylococcal strains. Crocetin was found to be the most effective as it diminished the biofilm formation of S. aureus ATCC 6538 significantly at 50 µg/mL without exhibiting bactericidal effect (MIC >800 µg/mL) and also inhibited the formation of biofilm by MSSA 25923 and S. epidermidis at a concentration as low as 2 µg/mL, and that by methicillin-resistant S. aureus MW2 at 100 µg/mL. It displayed minimal to no antibiofilm efficacy on the Gram-negative strains Escherichia coli O157:H7 and Pseudomonas aeruginosa as well as a fungal strain of Candida albicans. It could also curb the formation of fibrils, which partly contributes to the biofilm formation in S. epidermidis. Additionally, the ADME analysis of crocetin proclaims how relatively non-toxic the chemical is. Also, crocetin displayed synergistic antibiofilm characteristics in combination with tobramycin. The presence of a polyene chain with carboxylic acid groups at its ends is hypothesized to contribute to the strong antibiofilm characteristics of crocetin. These findings suggest that using apocarotenoids, particularly crocetin might help curb the biofilm formation by S. aureus and S. epidermidis.


Subject(s)
Anti-Bacterial Agents , Biofilms , Carotenoids , Microbial Sensitivity Tests , Staphylococcus epidermidis , Vitamin A , Biofilms/drug effects , Carotenoids/pharmacology , Vitamin A/analogs & derivatives , Vitamin A/pharmacology , Anti-Bacterial Agents/pharmacology , Staphylococcus epidermidis/drug effects , Candida albicans/drug effects , Staphylococcus aureus/drug effects , Humans , Pseudomonas aeruginosa/drug effects , Staphylococcus/drug effects
11.
Vestn Otorinolaringol ; 89(2): 88-94, 2024.
Article in Russian | MEDLINE | ID: mdl-38805469

ABSTRACT

According to the literature, acute otitis media is complicated by mastoiditis in 0.15-1% of cases. In turn, mastoiditis can be complicated by meningitis, encephalitis, abscess of temporal lobe of brain and cerebellum, epidural and subdural abscesses, facial nerve paresis, labyrinthitis, phlegmon of soft tissues of neck, as well as subperiosteal abscess, which makes 7% in the structure of mastoiditis complications. Nowadays, when doctors have a wide range of antibacterial preparations at their disposal, a complicated course of acute otitis media and further mastoiditis is caused both by an aggressive atypical infectious agent and immunocompromised status of a patient. The article deals with a clinical case of a prolonged course of acute otitis media complicated by mastoiditis and subperiosteal abscess against the background of outpatient courses of antibacterial therapy. The examination revealed an atypical pathogen of otitis media Pseudomonas aeruginosa and HIV-positive status of the patient, previously unknown. Timely surgical intervention and the right combination of antibacterial drugs, meropenem and ciprofloxacin, prevented the development of intracranial and septic complications, despite the presence of multiple foci of bone destruction of the mastoid process and temporal bone pyramid, bordering the middle fossa and sigmoid sinus, according to multispiral head computed tomography. As a part of additional examination in the Center for AIDS and Infectious Diseases Prevention and Control, the patient was diagnosed with HIV infection, clinical stage 4C, progressing phase on the background of absence of antiretroviral therapy, and the necessary amount of treatment was prescribed.


Subject(s)
Anti-Bacterial Agents , Mastoiditis , Otitis Media, Suppurative , Humans , Mastoiditis/etiology , Mastoiditis/diagnosis , Anti-Bacterial Agents/therapeutic use , Otitis Media, Suppurative/diagnosis , Male , HIV Infections/complications , Treatment Outcome , Pseudomonas Infections/diagnosis , Pseudomonas aeruginosa/isolation & purification , Adult , Tomography, X-Ray Computed/methods , Acute Disease , Meropenem/administration & dosage , Meropenem/therapeutic use
12.
PLoS One ; 19(5): e0304491, 2024.
Article in English | MEDLINE | ID: mdl-38805522

ABSTRACT

Due to high tolerance to antibiotics and pronounced virulence, bacterial biofilms are considered a key factor and major clinical challenge in persistent wound infections. They are typically composed of multiple species, whose interactions determine the biofilm's structural development, functional properties and thus the progression of wound infections. However, most attempts to study bacterial biofilms in vitro solely rely on mono-species populations, since cultivating multi-species biofilms, especially for prolonged periods of time, poses significant challenges. To address this, the present study examined the influence of bacterial composition on structural biofilm development, morphology and spatial organization, as well as antibiotic tolerance and virulence on human skin cells in the context of persistent wound infections. By creating a wound-mimetic microenvironment, the successful cultivation of dual-species biofilms of two of the most prevalent wound pathogens, Pseudomonas aeruginosa and Staphylococcus aureus, was realized over a period of 72 h. Combining quantitative analysis with electron microscopy and label-free imaging enabled a comprehensive evaluation of the dynamics of biofilm formation and matrix secretion, revealing a twofold increased maturation of dual-species biofilms. Antibiotic tolerance was comparable for both mono-species cultures, however, dual-species communities showed a 50% increase in tolerance, mediated by a significantly reduced penetration of the applied antibiotic into the biofilm matrix. Further synergistic effects were observed, where dual-species biofilms exacerbated wound healing beyond the effects observed from either Pseudomonas or Staphylococcus. Consequently, predicting biofilm development, antimicrobial tolerance and virulence for multi-species biofilms based solely on the results from mono-species biofilms is unreliable. This study underscores the substantial impact of a multi-species composition on biofilm functional properties and emphasizes the need to tailor future studies reflecting the bacterial composition of the respective in vivo situation, leading to a more comprehensive understanding of microbial communities in the context of basic microbiology and the development of effective treatments.


Subject(s)
Anti-Bacterial Agents , Biofilms , Pseudomonas aeruginosa , Staphylococcus aureus , Wound Infection , Biofilms/drug effects , Biofilms/growth & development , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/physiology , Pseudomonas aeruginosa/pathogenicity , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Humans , Virulence/drug effects , Wound Infection/microbiology , Wound Infection/drug therapy , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial/drug effects , Staphylococcal Infections/microbiology , Staphylococcal Infections/drug therapy , Microbial Sensitivity Tests , Pseudomonas Infections/microbiology , Pseudomonas Infections/drug therapy
13.
Front Cell Infect Microbiol ; 14: 1352339, 2024.
Article in English | MEDLINE | ID: mdl-38808066

ABSTRACT

Antibiotic drug combination therapy is critical for the successful treatment of infections caused by multidrug resistant pathogens. We investigated the efficacy of ß-lactam and ß-lactam/ß-lactamase inhibitor combinations with other antibiotics, against the hypervirulent, ceftazidime/avibactam resistant Pseudomonas aeruginosa Liverpool epidemic strain (LES) B58. Although minimum inhibitory concentrations in vitro differed by up to eighty-fold between standard and host-mimicking media, combinatorial effects only marginally changed between conditions for some combinations. Effective combinations in vitro were further tested in a chronic, high-density murine infection model. Colistin and azithromycin demonstrated combinatorial effects with ceftazidime and ceftazidime/avibactam both in vitro and in vivo. Conversely, while tobramycin and tigecycline exhibited strong synergy in vitro, this effect was not observed in vivo. Our approach of using host-mimicking conditions and a sophisticated animal model to evaluate drug synergy against bacterial pathogens represents a promising approach. This methodology may offer insights into the prediction of combination therapy outcomes and the identification of potential treatment failures.


Subject(s)
Abscess , Anti-Bacterial Agents , Disease Models, Animal , Drug Synergism , Drug Therapy, Combination , Microbial Sensitivity Tests , Pseudomonas Infections , Pseudomonas aeruginosa , Animals , Pseudomonas aeruginosa/drug effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/therapeutic use , Pseudomonas Infections/drug therapy , Pseudomonas Infections/microbiology , Mice , Abscess/drug therapy , Abscess/microbiology , Drug Combinations , Drug Resistance, Multiple, Bacterial , Female , Ceftazidime/pharmacology , Ceftazidime/therapeutic use , Azithromycin/pharmacology , Azithromycin/therapeutic use , Azithromycin/administration & dosage , Azabicyclo Compounds/pharmacology , Azabicyclo Compounds/therapeutic use , Colistin/pharmacology , Colistin/therapeutic use , Colistin/administration & dosage
14.
Biomolecules ; 14(5)2024 Apr 27.
Article in English | MEDLINE | ID: mdl-38785933

ABSTRACT

The problem of antimicrobial resistance is becoming a daunting challenge for human society and healthcare systems around the world. Hence, there is a constant need to develop new antibiotics to fight resistant bacteria, among other important social and economic measures. In this regard, murepavadin is a cyclic antibacterial peptide in development. The synthesis of murepavadin was undertaken in order to optimize the preparative protocol and scale-up, in particular, the use of new activation reagents. In our hands, classical approaches using carbodiimide/hydroxybenzotriazole rendered low yields. The use of novel carbodiimide and reagents based on OxymaPure® and Oxy-B is discussed together with the proper use of chromatographic conditions for the adequate characterization of peptide crudes. Higher yields and purities were obtained. Finally, the antimicrobial activity of different synthetic batches was tested in three Pseudomonas aeruginosa strains, including highly resistant ones. All murepavadin batches yielded the same highly active MIC values and proved that the chiral integrity of the molecule was preserved throughout the whole synthetic procedure.


Subject(s)
Anti-Bacterial Agents , Microbial Sensitivity Tests , Peptides, Cyclic , Pseudomonas aeruginosa , Pseudomonas aeruginosa/drug effects , Peptides, Cyclic/chemistry , Peptides, Cyclic/chemical synthesis , Peptides, Cyclic/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemical synthesis , Anti-Bacterial Agents/chemistry , Antimicrobial Peptides/chemistry , Antimicrobial Peptides/chemical synthesis , Antimicrobial Peptides/pharmacology , Carbodiimides/chemistry , Humans
15.
Arch Microbiol ; 206(6): 272, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38772980

ABSTRACT

Phage-encoded endolysins have emerged as a potential substitute to conventional antibiotics due to their exceptional benefits including host specificity, rapid host killing, least risk of resistance. In addition to their antibacterial potency and biofilm eradication properties, endolysins are reported to exhibit synergism with other antimicrobial agents. In this study, the synergistic potency of endolysins was dissected with antimicrobial peptides to enhance their therapeutic effectiveness. Recombinantly expressed and purified bacteriophage endolysin [T7 endolysin (T7L); and T4 endolysin (T4L)] proteins have been used to evaluate the broad-spectrum antibacterial efficacy using different bacterial strains. Antibacterial/biofilm eradication studies were performed in combination with different antimicrobial peptides (AMPs) such as colistin, nisin, and polymyxin B (PMB) to assess the endolysin's antimicrobial efficacy and their synergy with AMPs. In combination with T7L, polymyxin B and colistin effectively eradicated the biofilm of Pseudomonas aeruginosa and exhibited a synergistic effect. Further, a combination of T4L and nisin displayed a synergistic effect against Staphylococcus aureus biofilms. In summary, the obtained results endorse the theme of combinational therapy consisting of endolysins and AMPs as an effective remedy against the drug-resistant bacterial biofilms that are a serious concern in healthcare settings.


Subject(s)
Anti-Bacterial Agents , Antimicrobial Peptides , Biofilms , Drug Synergism , Endopeptidases , Microbial Sensitivity Tests , Pseudomonas aeruginosa , Staphylococcus aureus , Biofilms/drug effects , Endopeptidases/pharmacology , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Staphylococcus aureus/drug effects , Staphylococcus aureus/physiology , Pseudomonas aeruginosa/drug effects , Antimicrobial Peptides/pharmacology , Antimicrobial Peptides/chemistry , Nisin/pharmacology , Nisin/chemistry , Polymyxin B/pharmacology , Bacteriophages , Colistin/pharmacology , Bacteriophage T4/drug effects , Bacteriophage T4/physiology , Bacteriophage T7/drug effects , Bacteriophage T7/genetics
16.
Antimicrob Resist Infect Control ; 13(1): 54, 2024 May 21.
Article in English | MEDLINE | ID: mdl-38769515

ABSTRACT

BACKGROUND: Currently, different guidelines recommend using different methods to determine whether deduplication is necessary when determining the detection rates of multidrug-resistant organisms (MDROs). However, few studies have investigated the effect of deduplication on MDRO monitoring data. In this study, we aimed to investigate the influence of deduplication on the detection rates of MDROs in different specimens to assess its impact on infection surveillance outcomes. METHODS: Samples were collected from hospitalized patients admitted between January 2022 and December 2022; four types of specimens were collected from key monitored MDROs, including sputum samples, urine samples, blood samples, and bronchoalveolar lavage fluid (BALF) samples. In this study, we compared and analysed the detection rates of carbapenem-resistant Klebsiella pneumoniae (CRKP), carbapenem-resistant Escherichia coli (CRECO), carbapenem-resistant Acinetobacter baumannii (CRAB), carbapenem-resistant Pseudomonas aeruginosa (CRPA), and methicillin-resistant Staphylococcus aureus (MRSA) under two conditions: with and without deduplication. RESULTS: When all specimens were included, the detection rates of CRKP, CRAB, CRPA, and MRSA without deduplication (33.52%, 77.24%, 44.56%, and 56.58%, respectively) were significantly greater than those with deduplication (24.78%, 66.25%, 36.24%, and 50.83%, respectively) (all P < 0.05). The detection rates in sputum samples were significantly different between samples without duplication (28.39%, 76.19%, 46.95%, and 70.43%) and those with deduplication (19.99%, 63.00%, 38.05%, and 64.50%) (all P < 0.05). When deduplication was not performed, the rate of detection of CRKP in urine samples reached 30.05%, surpassing the rate observed with deduplication (21.56%) (P < 0.05). In BALF specimens, the detection rates of CRKP and CRPA without deduplication (39.78% and 53.23%, respectively) were greater than those with deduplication (31.62% and 42.20%, respectively) (P < 0.05). In blood samples, deduplication did not have a significant impact on the detection rates of MDROs. CONCLUSION: Deduplication had a significant effect on the detection rates of MDROs in sputum, urine, and BALF samples. Based on these data, we call for the Infection Prevention and Control Organization to align its analysis rules with those of the Bacterial Resistance Surveillance Organization when monitoring MDRO detection rates.


Subject(s)
Cross Infection , Drug Resistance, Multiple, Bacterial , Klebsiella pneumoniae , Sputum , Humans , Cross Infection/microbiology , Cross Infection/epidemiology , Klebsiella pneumoniae/genetics , Klebsiella pneumoniae/isolation & purification , Klebsiella pneumoniae/drug effects , Sputum/microbiology , Methicillin-Resistant Staphylococcus aureus/isolation & purification , Methicillin-Resistant Staphylococcus aureus/genetics , Acinetobacter baumannii/drug effects , Acinetobacter baumannii/isolation & purification , Acinetobacter baumannii/genetics , Anti-Bacterial Agents/pharmacology , Pseudomonas aeruginosa/drug effects , Pseudomonas aeruginosa/isolation & purification , Pseudomonas aeruginosa/genetics , Bronchoalveolar Lavage Fluid/microbiology , Carbapenems/pharmacology , Escherichia coli/isolation & purification , Escherichia coli/drug effects , Escherichia coli/genetics , Epidemiological Monitoring , Hospitals
17.
Photobiomodul Photomed Laser Surg ; 42(5): 356-365, 2024 May.
Article in English | MEDLINE | ID: mdl-38776546

ABSTRACT

Background: Nosocomial wound infection with Pseudomonas aeruginosa (PA) is a serious complication often responsible for the septic mortality of burn patients. Objective: High-intensity antimicrobial blue light (aBL) treatment may represent an alternative therapy for PA infections and will be investigated in this study. Methods: Antibacterial effects of a light-emitting diode array (450-460 nm; 300 mW/cm2; 15/30 min; 270/540 J/cm2) against PA were determined by suspension assay, biofilm assay, and a human skin wound model and compared with 15-min topically applied 3% citric acid (CA) and wound irrigation solution (Prontosan®; PRT). Results: aBL reduced the bacterial number [2.51-3.56 log10 colony-forming unit (CFU)/mL], whereas PRT or CA treatment achieved a 4.64 or 6.60 log10 CFU/mL reduction in suspension assays. aBL reduced biofilm formation by 60-66%. PRT or CA treatment showed reductions by 25% or 13%. Here, aBL reduced bacterial number in biofilms (1.30-1.64 log10 CFU), but to a lower extend than PRT (2.41 log10 CFU) or CA (2.48 log10 CFU). In the wound skin model, aBL (2.21-2.33 log10 CFU) showed a bacterial reduction of the same magnitude as PRT (2.26 log10 CFU) and CA (2.30 log10 CFU). Conclusions: aBL showed a significant antibacterial efficacy against PA and biofilm formation in a short time. However, a clinical application of aBL in wound therapy requires effective active skin cooling and eye protection, which in turn may limit clinical implementation.


Subject(s)
Biofilms , Pseudomonas Infections , Pseudomonas aeruginosa , Wound Infection , Humans , Pseudomonas aeruginosa/radiation effects , Biofilms/radiation effects , Pseudomonas Infections/therapy , Pseudomonas Infections/radiotherapy , Wound Infection/therapy , Wound Infection/microbiology , Phototherapy , Blue Light
18.
Microbiologyopen ; 13(3): e1415, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38780167

ABSTRACT

The standard method of receptor activation involves the binding of signals or signal-loaded solute binding proteins (SBPs) to sensor domains. Many sensor histidine kinases (SHKs), which are activated by SBP binding, are encoded adjacent to their corresponding sbp gene. We examined three SBPs of Pseudomonas aeruginosa PAO1, encoded near the genes for the AgtS (PA0600) and AruS (PA4982) SHKs, to determine how common this arrangement is. Ligand screening and microcalorimetric studies revealed that the SBPs PA0602 and PA4985 preferentially bind to GABA (KD = 2.3 and 0.58 µM, respectively), followed by 5-aminovalerate (KD = 30 and 1.6 µM, respectively) and ethanoldiamine (KD = 2.3 and 0.58 µM, respectively). In contrast, AgtB (PA0604) exclusively recognizes 5-aminovaleric acid (KD = 2.9 µM). However, microcalorimetric titrations did not show any binding between the AgtS sensor domain and AgtB or PA0602, regardless of the presence of ligands. Similarly, bacterial two-hybrid assays did not demonstrate an interaction between PA4985 and the AruS sensor domain. Therefore, sbp and shk genes located nearby are not always functionally linked. We previously identified PA0222 as a GABA-specific SBP. The presence of three SBPs for GABA may be linked to GABA's role as a trigger for P. aeruginosa virulence.


Subject(s)
Bacterial Proteins , Protein Binding , Pseudomonas aeruginosa , gamma-Aminobutyric Acid , Pseudomonas aeruginosa/metabolism , Pseudomonas aeruginosa/genetics , Pseudomonas aeruginosa/enzymology , gamma-Aminobutyric Acid/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Amino Acids, Neutral/metabolism , Histidine Kinase/metabolism , Histidine Kinase/genetics , Calorimetry
19.
J Oleo Sci ; 73(5): 787-799, 2024.
Article in English | MEDLINE | ID: mdl-38692900

ABSTRACT

Launaea sarmentosa, also known as Sa Sam Nam, is a widely used remedy in Vietnamese traditional medicine and cuisine. However, the chemical composition and bioactivity of its essential oil have not been elucidated yet. In this study, we identified 40 compounds (98.6% of total peak area) in the essential oil via GC-MS analysis at the first time. Among them, five main compounds including Thymohydroquinone dimethyl ether (52.4%), (E)-α-Atlantone (9.0%), Neryl isovalerate (6.6%), Davanol D2 (isomer 2) (3.9%), and trans-Sesquisabinene hydrate (3.9%) have accounted for 75.8% of total peak area. The anti-bacterial activity of the essential oil against 4 microorganisms including Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa has also investigated via agar well diffusion assay. The results showed that the essential oil exhibited a strong antibacterial activity against Bacillus subtilis with the inhibition zones ranging from 8.2 to 18.7 mm. To elucidate the anti-bacterial effect mechanism of the essential oil, docking study of five main compounds of the essential oil (Thymohydroquinone dimethyl ether, (E)-α-Atlantone, Neryl isovalerate, Davanol D2 (isomer 2), and trans-Sesquisabinene hydrate) against some key proteins for bacterial growth such as DNA gyrase B, penicillin binding protein 2A, tyrosyl-tRNA synthetase, and dihydrofolate reductase were performed. The results showed that the main constituents of essential oil were highly bound with penicillin binding protein 2A with the free energies ranging -27.7 to -44.8 kcal/mol, which suggests the relationship between the antibacterial effect of essential oil and the affinity of main compounds with penicillin binding protein. In addition, the free energies of main compounds of the essential oil with human cyclooxygenase 1, cyclooxygenase 2, and phospholipase A2, the crucial proteins related with inflammatory response were less than diclofenac, a non-steroidal antiinflammatory drug. These findings propose the essential oil as a novel and promising anti-bacterial and anti-inflammatory medicine or cosmetic products.


Subject(s)
Anti-Bacterial Agents , Bacillus subtilis , Hemiterpenes , Molecular Docking Simulation , Oils, Volatile , Pentanoic Acids , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/isolation & purification , Anti-Bacterial Agents/chemistry , Oils, Volatile/pharmacology , Oils, Volatile/chemistry , Oils, Volatile/isolation & purification , Bacillus subtilis/drug effects , Staphylococcus aureus/drug effects , Pseudomonas aeruginosa/drug effects , Escherichia coli/drug effects , Tetrahydrofolate Dehydrogenase/metabolism , DNA Gyrase/metabolism , Sesquiterpenes/isolation & purification , Sesquiterpenes/pharmacology , Microbial Sensitivity Tests , Gas Chromatography-Mass Spectrometry
20.
J Pak Med Assoc ; 74(4): 661-665, 2024 Apr.
Article in English | MEDLINE | ID: mdl-38751258

ABSTRACT

Objectives: To identify various species of non-lactose fermenting gram-negative bacilli involved in urinary tract infections, and to determine their antimicrobial resistance pattern. METHODS: The retrospective, descriptive, cross-sectional study was conducted from January 1 to April 1, 2022, at the Dow University of Health Sciences, Karachi, and comprised data from the institutional diagnostic laboratory that was related to urine samples regardless of age and gender from January 1, 2020, to December 31, 2021. Data was analysed using SPSS version 25. RESULTS: Of the 103,887 urine samples, 41,280(39.7%) were positive, 51,146(49.2%) showed no bacterial growth, 11,000(10.6%) had non-significant bacterial growth and 461(0.4%) had mixed bacterial growth. Of the positive samples, 18359(44.5%) were positive in 2020, and 22,921(55.5%) in 2021. Gram-negative lactose fermenting bacteria included escherichia coli 23,123(22.3%) and klebsiella pneumoniae 2,993(2.9%), gram-negative non-lactose fermenting bacteria included pseudomonas aeruginosa 1,110(1.07%), and gram-positive bacteria included enterococcus 8,008(7.7%). Pseudomonas aeruginosa was most resistant against tobramycin 880(79.3%) and least resistant against piperacillin-tazobactam 146(13%). CONCLUSIONS: Piperacillin-tazobactam was highly sensitive drug against non-lactose fermenting uro-pathogens.


Subject(s)
Anti-Bacterial Agents , Gram-Negative Bacteria , Urinary Tract Infections , Humans , Gram-Negative Bacteria/drug effects , Urinary Tract Infections/microbiology , Urinary Tract Infections/drug therapy , Cross-Sectional Studies , Retrospective Studies , Male , Female , Anti-Bacterial Agents/pharmacology , Drug Resistance, Bacterial , Klebsiella pneumoniae/drug effects , Klebsiella pneumoniae/metabolism , Escherichia coli/drug effects , Escherichia coli/metabolism , Pseudomonas aeruginosa/drug effects , Microbial Sensitivity Tests , Gram-Negative Bacterial Infections/microbiology , Gram-Negative Bacterial Infections/drug therapy , Adult , Pakistan , Enterococcus/drug effects , Middle Aged
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