Simultaneous immobilization of multiple heavy metal(loid)s in contaminated water and alkaline soil inoculated Fe/Mn oxidizing bacterium.

Two strains of Fe/Mn oxidizing bacteria tolerant to high concentrations of multiple heavy metal(loid)s and efficient decontamination for them were screened. The surface of the bio-Fe/Mn oxides produced by the oxidation of Fe(II) and Mn(II) by Pseudomonas taiwanensis (marked as P4) and Pseudomonas plecoglossicida (marked as G1) contains rich reactive oxygen functional groups, which play critical roles in the removal efficiency and immobilization of heavy metal(loid)s in co-contamination system. The isolated strains P4 and G1 can grow well in the following environments: pH 5-9, NaCl 0-4%, and temperature 20-30°C. The removal efficiencies of Fe, Pb, As, Zn, Cd, Cu, and Mn are effective after inoculation of the strains P4 and G1 in the simulated water system (the initial concentrations of heavy metal(loid) were 1 mg/L), approximately reaching 96%, 92%, 85%, 67%, 70%, 54% and 15%, respectively. The exchangeable and carbonate bound As, Cd, Pb and Cu are more inclined to convert to the Fe-Mn oxide bound fractions in P4 and G1 treated soil, thereby reducing the phytoavailability and bioaccessible of heavy metal(loid)s. This research provides alternatives method to treat water and soil containing high concentrations of multi-heavy metal(loid)s.

Biodegradation of combined pollutants of polyethylene terephthalate and phthalate esters by esterase-integrated Pseudomonas sp. JY-Q with surface-co-displayed PETase and MHETase.

The waste pollution problem caused by polyethylene terephthalate (PET) plastics poses a huge threat to the environment and human health. As plasticizers, Phthalate esters (PAEs) are widely used in PET production and become combined pollutants with PET. Synthetic biology make it possible to construct engineered cells for microbial degradation of combined pollutants of PET and PAEs. PET hydroxylase (PETase) and monohydroxyethyl terephthalate hydroxylase (MHETase) isolated from Ideonella sakaiensis 201-F6 exhibit the capability to depolymerize PET. However, PET cannot enter cells, thus enzymatic degradation or cell surface displaying technology of PET hydrolase are the potential strategies. In this study, Pseudomonas sp. JY-Q was selected as a chassis strain, which exhibits robust stress tolerance. First, a truncated endogenous outer membrane protein cOmpA and its variant Signal (OprF)-cOmpA were selected as anchor motifs for exogenous protein to display on the cell surface. These anchor motifs were fused at the N-terminal of PET hydrolase and MHETase and transformed into Pseudomonas sp. JY-Q, the mutant strains successfully display the enzymes on cell surface, after verification by green fluorescent protein labeling and indirect immunofluorescence assay. The resultant strains also showed the catalytic activity of co-displaying PETase and MHETase for PET biodegradation. Then, the cell surface displaying PET degradation module was introduced to a JY-Q strain which genome was integrated with PAEs degrading enzymes and exhibited PAEs degradation ability. The resultant strain JY-Q-R1-R4-SFM-TPH have the ability of degradation PET and PAEs simultaneously. This study provided a promising strain resource for PET and PAEs pollution control.

Can cadmium-contaminated rice be used to produce food additive sodium erythorbate?

Cadmium (Cd) in rice is a significant concern for its quality and safety. Currently, there is a crucial need to develop cost-effective and efficient ways to remove Cd or re-utilize Cd-contaminated rice. The food additive sodium erythorbate is produced via 2-ketogluconic acid (2KGA) fermentation by Pseudomonas plecoglossicida and lactonization using starch-rich raw materials, such as rice. We aimed to determine whether cadmium-contaminated rice can be used to produce sodium erythorbate. To achieve this aim, the migration of cadmium during the production of sodium erythorbate from Cd-contaminated rice was studied. Five rice varieties with different Cd contents from 0.10 to 0.68 mg/kg were used as raw materials. The results indicated the presence of Cd in rice and CaCO3 did not have a notable impact on the fermentation performance of 2KGA. The acidification of 2KGA fermentation broth, the addition of K4Fe(CN)6·3H2O and ZnSO4, and 2KGA purification using cation exchange effectively removed >98% of the Cd in the fermentation broth, but the 2KGA yield remained high at approximately 94%. The sodium erythorbate synthesized from Cd-contaminated rice was of high quality and free from Cd, meeting the requirements of the Chinese National Standard, GB 1886.28-2016. The study provided a safe and effective strategy for comprehensively utilizing Cd-contaminated rice to produce high value-added food additive.

CCR2+ monocytes are dispensable to resolve acute pulmonary Pseudomonas aeruginosa infections in WT and Cystic Fibrosis mice.

Extravasation of CCR2-positive monocytes into tissue and to the site of injury is a fundamental immunological response to infections. Nevertheless, exuberant recruitment and/or activity of these monocytes and monocyte-derived macrophages can propagate tissue damage, especially in chronic inflammatory disease conditions. We have previously shown that inhibiting the recruitment of CCR2-positive monocytes ameliorates lung tissue damage caused by chronic neutrophilic inflammation in cystic fibrosis (CF) mouse models. A potential concern with targeting monocyte recruitment for therapeutic benefit in CF, however, is whether they are essential for eradicating infections such as Pseudomonas aeruginosa (PA), a pathogen that commonly colonizes and damages the lungs of patients with CF. In this study, we investigated the role of CCR2-positive monocytes in the immune response to acute pulmonary PA infection. Our data show that the altered host immune response caused by the lack of monocyte recruitment to the lungs does not impact PA lung colonization, clearance, and the severity of the infection. These results also hold up in a CF mouse background, which have a hyper-inflammatory immune response, yet exhibit reduced bactericidal activity. Thus, we lay the groundwork for future studies to investigate the use of CCR2 inhibitors as a potential therapy to ameliorate lung tissue damage in CF. This could be given alone or as an adjunct therapy with CFTR modulators that significantly improve clinical outcomes for eligible patients, but do not completely resolve the persistent infection and inflammation that drive lung tissue damage.

Microbiome and metabolome patterns after lung transplantation reflect underlying disease and chronic lung allograft dysfunction.

BACKGROUND: Progression of chronic lung disease may lead to the requirement for lung transplant (LTx). Despite improvements in short-term survival after LTx, chronic lung allograft dysfunction (CLAD) remains a critical challenge for long-term survival. This study investigates the molecular and microbial relationships between underlying lung disease and the development of CLAD in bronchoalveolar lavage fluid (BALF) from subjects post-LTx, which is crucial for tailoring treatment strategies specific to allograft dysfunctions. METHODS: Paired 16S rRNA gene amplicon sequencing and untargeted LC-MS/MS metabolomics were performed on 856 BALF samples collected over 10 years from LTx recipients (n = 195) with alpha-1-antitrypsin disease (AATD, n = 23), cystic fibrosis (CF, n = 47), chronic obstructive pulmonary disease (COPD, n = 78), or pulmonary fibrosis (PF, n = 47). Data were analyzed using random forest (RF) machine learning and multivariate statistics for associations with underlying disease and CLAD development. RESULTS: The BALF microbiome and metabolome after LTx differed significantly according to the underlying disease state (PERMANOVA, p = 0.001), with CF and AATD demonstrating distinct microbiome and metabolome profiles, respectively. Uniqueness in CF was mainly driven by Pseudomonas abundance and its metabolites, whereas AATD had elevated levels of phenylalanine and a lack of shared metabolites with the other underlying diseases. BALF microbiome and metabolome composition were also distinct between those who did or did not develop CLAD during the sample collection period (PERMANOVA, p = 0.001). An increase in the average abundance of Veillonella (AATD, COPD) and Streptococcus (CF, PF) was associated with CLAD development, and decreases in the abundance of phenylalanine-derivative alkaloids (CF, COPD) and glycerophosphorylcholines (CF, COPD, PF) were signatures of the CLAD metabolome. Although the relative abundance of Pseudomonas was not associated with CLAD, the abundance of its virulence metabolites, including siderophores, quorum-sensing quinolones, and phenazines, were elevated in those with CF who developed CLAD. There was a positive correlation between the abundance of these molecules and the abundance of Pseudomonas in the microbiome, but there was no correlation between their abundance and the time in which BALF samples were collected post-LTx. CONCLUSIONS: The BALF microbiome and metabolome after LTx are particularly distinct in those with underlying CF and AATD. These data reflect those who developed CLAD, with increased virulence metabolite production from Pseudomonas, an aspect of CF CLAD cases. These findings shed light on disease-specific microbial and metabolic signatures in LTx recipients, offering valuable insights into the underlying causes of allograft rejection. Video Abstract.

The battle within: how Pseudomonas aeruginosa uses host-pathogen interactions to infect the human lung.

Pseudomonas aeruginosa is a versatile Gram-negative pathogen known for its ability to invade the respiratory tract, particularly in cystic fibrosis patients. This review provides a comprehensive analysis of the multifaceted strategies for colonization, virulence, and immune evasion used by P. aeruginosa to infect the host. We explore the extensive protein arsenal of P. aeruginosa, including adhesins, exotoxins, secreted proteases, and type III and VI secretion effectors, detailing their roles in the infective process. We also address the unique challenge of treating diverse lung conditions that provide a natural niche for P. aeruginosa on the airway surface, with a particular focus in cystic fibrosis. The review also discusses the current limitations in treatment options due to antibiotic resistance and highlights promising future approaches that target host-pathogen protein-protein interactions. These approaches include the development of new antimicrobials, anti-attachment therapies, and quorum-sensing inhibition molecules. In summary, this review aims to provide a holistic understanding of the pathogenesis of P. aeruginosa in the respiratory system, offering insights into the underlying molecular mechanisms and potential therapeutic interventions.

Changes in factors associated with inhaled antibiotic prescriptions for people with cystic fibrosis over time in the U.S.

RATIONALE: CF care guidelines recommend chronic inhaled antibiotics for chronic Pseudomonas aeruginosa (Pa) lung infection. These medications are costly, time consuming and prescription needs may change with improved outcomes. OBJECTIVES: We determined the proportion of pwCF with chronic, intermittent or negative Pa infection categories, their clinical and demographic characteristics, factors associated with inhaled antibiotic prescription and changes between 2011 and 2019. METHODS: This cohort study using the U.S. CF Foundation patient registry for pwCF >2 years, no prior lung transplant, and with ≥3 respiratory cultures/year determined chronic inhaled antibiotics (≥3 months per calendar year) and Pa infection status from encounter level data. Outcomes and odds of prescription for relevant clinical factors were evaluated using generalized estimating equation models with additional interaction between the predictor and the calendar year to examine changes of predictors over time. RESULTS: Proportion of pwCF with chronic and intermittent Pa decreased and antibiotic prescription rates increased for these groups and decreased for Pa negative pwCF. Hispanic ethnicity, female sex, pancreatic insufficiency, CF diabetes, and ivacaftor/lumacaftor were associated with higher antibiotic prescriptions for each Pa status. Among Pa-negative pwCF prescriptions were higher with Burkholderia spp. (1.17, (CI95 1.03,1.34)) or MRSA (OR 1.45, (1.26,1.68)) but decreased between 2011 and 2019. For Aspergillus OR increased to 1.6,(1.3,1.8) in 2019. Prescriptions for pwCF on ivacaftor decreased, becoming lower in 2019 for chronic (OR 0.7, (0.5,0.8)) and Pa-negative pwCF (OR 0.7, (0.5,0.8)). CONCLUSIONS: Factors predicting inhaled antibiotic prescription differed between 2011 and 2019 indicating changes in health and care for pwCF even prior to triple-modulators.

Unlocking sustainable solutions: wood waste as a novel substrate for polyhydroxybutyrate (PHB) production to combat plastic pollution.

Polyhydroxybutyrate (PHB) is considered as a hope for bioplastic production, which can serve as a sustainable alternative. Utilizing feedstock as substrate is widely explored for the production but wood waste, which is abundant in cellulose, hemicellulose and lignocellulose, has limited studies for PHB production. Herein, wood waste is used as a biobased feedstock Hydrolyses of wood waste was done using sulphuric acid (H2SO4) to break down of cellulose and hemicellulose into simple carbon forms. The hydrolysed product was analysed for sugar presence by quantitative and qualitative methods. Pseudomonas fluorescens bacterial strain was used for the production purpose using hydrolysed wood waste as substrate media. The Plackett-Burman design (PBD) and response surface methodology (RSM) were applied to optimize the growth media. The results of PBD were used to identify significant factors influencing PHB production, which were then further optimized using RSM. The work's results conclusively demonstrated that P. fluorescens possesses the capability to effectively utilize wood waste and wastewater as substrate media up to production rate of 13-14 mg mL-1 of PHB. Fourier Transformed Infra-Red (FTIR) spectroscopic peaks confirm the produced product is PHB, which is a type of polyhydroxyalkanoate (PHA), classified within the polyester family highlighting wood waste potential as a sustainable solution to address plastic pollution.

Antimicrobial mechanisms and antifungal activity of compounds generated by banana rhizosphere Pseudomonas aeruginosa Gxun-2 against fusarium oxysporum f. sp. cubense.

Introduction: Fusarium wilt of banana, also recognized as Panama disease, is caused by the soil-borne fungus Fusarium oxysporum f. sp. cubense tropical race 4 (FOC TR4). In recent years, strategies utilizing biocontrol agents, comprising antifungal microorganisms and their associated bioactive compounds from various environments, have been implemented to control this destructive disease. Our previous study showed that Pseudomonas aeruginosa Gxun-2 had significant antifungal effects against FOC TR4. However, there has been little scientific investigation of the antibacterial or antifungal activity. The aim of this study was to isolate, identify and evaluate the inhibition strength of active compounds in P. aeruginosa Gxun-2, so as to explain the mechanism of the strain inhibition on FOC TR4 from the perspective of compounds. Methods: The main antibacterial compounds of strain Gxun-2 were isolated, purified and identified using by fermentation extraction, silica gel column chromatography, thin-layer chromatography (TLC), high-performance liquid chromatography (HPLC), and nuclear magnetic resonance (NMR) techniques. The effect of the compounds on the mycelial growth, morphology and spore germination of strain FOC TR4 was observed by 96-well plate method and AGAR diffusion method. Results: Among the metabolites produced by the strain, four antifungal compounds which were identified phenazine (C12H8N2), phenazine-1-carboxylic acid (PCA) (C13H8N2O2), 2-acetamidophenol (C8H9NO2) and aeruginaldehyde (C10H7NO2S) were identified through HPLC and NMR. Of these compounds, phenazine and PCA exhibited the most pronounced inhibitory effects on the spore germination and mycelial growth of FOC TR4. Phenazine demonstrated potent antifungal activity against FOC TR4 with a minimum inhibitory concentration (MIC) of 6.25 mg/L. The half-maximal effective concentration (EC50) was calculated to be 26.24 mg/L using the toxicity regression equation. PCA exhibited antifungal activity against FOC TR4 with an MIC of 25 mg/L and an EC50 of 89.63 mg/L. Furthermore, phenazine and PCA triggered substantial morphological transformations in the mycelia of FOC TR4, encompassing folding, bending, fracturing, and diminished spore formation. Discussion: These findings indicate that strain Gxun-2 plays a crucial role in controlling FOC TR4 pathogenesis, predominantly through producing the antifungal compounds phenazine and PCA, and possesses potential as a cost-efficient and sustainable biocontrol agent against Fusarium wilt of banana in forthcoming times.

Impact of bacterial co-isolation on treatment initiation and long-term prognosis of patients with nontuberculous mycobacterial pulmonary disease: analysis of a prospective cohort study.

BACKGROUND: Nontuberculous mycobacterial pulmonary disease (NTM-PD), a chronic respiratory condition, presents a growing challenge globally. Uncertainties exist regarding the impact of concurrent bacterial co-isolation on treatment initiation and long-term prognosis. METHODS: This study analysed data from participants enrolled in an ongoing prospective observational cohort study on NTM-PD (NCT01616745) between 1 July 2011, and 31 December 2022, who provided sputum samples for bacterial culture at enrolment. Identification of potential pathogenic microorganisms (PPMs) was defined as a positive bacterial culture. Clinical characteristics were compared between NTM-PD patients with Pseudomonas, non-pseudomonal PPMs, and those without PPM co-isolation. Cox proportional hazard regression models were employed to assess the association of bacterial co-isolation with rates of NTM-PD treatment initiation and all-cause mortality. RESULTS: Overall, 453 patients (median age, 62 years; 30% male) were included in the analysis. PPMs were co-isolated in 77 patients (17%), including 13 with Pseudomonas species. Co-isolation of Pseudomonas was associated with a significantly higher erythrocyte sedimentation rate (P = 0.02) and St. George's Respiratory Questionnaire score (P = 0.01). Non-pseudomonal PPM co-isolation was significantly associated with a higher likelihood of NTM-PD treatment initiation (adjusted hazards ratio [aHR], 1.56, 95% confidence interval [CI], 1.03-2.36, P = 0.036), whereas co-isolation of Pseudomonas was independently correlated with increased all-cause mortality (aHR, 3.25, 95% CI, 1.08-9.84, P = 0.037). CONCLUSIONS: Our findings emphasize the importance of microbial surveillance, as bacterial co-isolation affects treatment initiation and prognosis in patients with NTM-PD.

L-asparaginase-driven antibiosis in Pseudomonas fluorescens EK007: A promising biocontrol strategy against fire blight.

Fire blight, caused by Erwinia amylovora, is a destructive bacterial disease affecting pear and apple trees. The biocontrol ability of Pseudomonas fluorescens EK007 suppresses E. amylovora through competitive exclusion. In this study, EK007 was isolated from the pear phylloplane and characterized as an effective biological agent through antibacterial compounds. To identify the mechanisms underlying EK007's biocontrol activity, physiological tests, transposon insertion mutant libraries, allelic exchange, and whole-genome sequencing were performed. A transposon mutation in the massC homolog gene, part of the massetolide A lipopeptide biosynthesis cluster, reduced the biocontrol efficiency. Allelic exchange confirmed cyclic lipopeptide (CLP) as part of the mechanism. Additionally, a gacA mutant isolated by transposon mutagenesis showed deficient inhibition activity. Culture conditions and nutritional sources clearly influenced EK007's antimicrobial activity against E. amylovora. Growth yield generally correlated with antibiotic production, with amino acids and iron affecting production. Asparagine and aspartate shut down biocontrol activity. This study presents preliminary findings on a novel CLP that may contribute to EK007's antibacterial activity against E. amylovora. While EK007 shows promise as a biocontrol candidate compared to related strains, these results are based solely on in vitro studies, highlighting the need for further investigations to evaluate its efficacy in natural environments.

Antibacterial and anti-biofilm efficacy of selenium nanoparticles against Pseudomonas aeruginosa: Characterization and in vitro analysis.

Pseudomonas aeruginosa (P. aeruginosa), a Gram-negative opportunistic pathogen, poses significant treatment challenges due to its antibiotic resistance and biofilm formation. This study investigates the anti-bacterial and anti-biofilm activities of chemically synthesized selenium nanoparticles (SeNPs) against P. aeruginosa. SeNPs were synthesized using ascorbic acid as a reducing agent and characterized. Biofilm formation was quantified using a modified microtiter plate method, and the anti-biofilm efficacy of SeNPs was evaluated using confocal microscopy and SEM. The P.aeruginosa isolates exhibited high resistance to piperacillin-tazobactam (60%) and ceftazidime (59%). SeNPs demonstrated a round shape with a diameter of 15-18 nm. UV-Vis spectra showed a peak at 275 nm, and XRD analysis revealed crystalline peaks corresponding to selenium. The FTIR spectra confirmed the presence of various functional groups. SeNPs significantly reduced biofilm formation in a dose-dependent manner, with MIC50 and MIC90 values of 60 µg/mL and 80 µg/mL, respectively. Confocal microscopy and SEM analysis showed a notable decrease in biofilm thickness and bacterial adherence post-SeNPs treatment. These findings suggest that SeNPs could be a promising alternative or adjunctive treatment option for combating antibiotic-resistant P. aeruginosa infections. Further research is warranted to explore the clinical applications of SeNPs in treating biofilm-associated infections.

A "love match" score to compare root exudate attraction and feeding of the plant growth-promoting rhizobacteria Bacillus subtilis, Pseudomonas fluorescens, and Azospirillum brasilense.

Introduction: The rhizosphere is the zone of soil surrounding plant roots that is directly influenced by root exudates released by the plant, which select soil microorganisms. The resulting rhizosphere microbiota plays a key role in plant health and development by enhancing its nutrition or immune response and protecting it from biotic or abiotic stresses. In particular, plant growth-promoting rhizobacteria (PGPR) are beneficial members of this microbiota that represent a great hope for agroecology, since they could be used as bioinoculants for sustainable crop production. Therefore, it is necessary to decipher the molecular dialog between roots and PGPR in order to promote the establishment of bioinoculants in the rhizosphere, which is required for their beneficial functions. Methods: Here, the ability of root exudates from rapeseed (Brassica napus), pea (Pisum sativum), and ryegrass (Lolium perenne) to attract and feed three PGPR (Bacillus subtilis, Pseudomonas fluorescens, and Azospirillum brasilense) was measured and compared, as these responses are directly involved in the establishment of the rhizosphere microbiota. Results: Our results showed that root exudates differentially attracted and fed the three PGPR. For all beneficial bacteria, rapeseed exudates were the most attractive and induced the fastest growth, while pea exudates allowed the highest biomass production. The performance of ryegrass exudates was generally lower, and variable responses were observed between bacteria. In addition, P. fluorescens and A. brasilense appeared to respond more efficiently to root exudates than B. subtilis. Finally, we proposed to evaluate the compatibility of each plant-PGPR couple by assigning them a "love match" score, which reflects the ability of root exudates to enhance bacterial rhizocompetence. Discussion: Taken together, our results provide new insights into the specific selection of PGPR by the plant through their root exudates and may help to select the most effective exudates to promote bioinoculant establishment in the rhizosphere.

A Case of Catheter-Associated Urinary Tract Infection by Pseudomonas mendocina in the Setting of COVID-19.

Pseudomonas mendocina, a Gram-negative, aerobic bacillus, has rarely been implicated in human infections. This report details the first documented case of catheter-associated urinary tract infection (CAUTI) caused by P. mendocina in a COVID-19-positive patient. We present the case of a 70-year-old male with obstructive uropathy who presented with altered mental status eight days after testing positive for COVID-19. Urine cultures identified P. mendocina and Enterococcus faecalis. The antibiotic regimen was adjusted to cefepime and fosfomycin for coverage against P. mendocina and E. faecalis, respectively, resulting in the patient's improvement and discharge with an outpatient course of ciprofloxacin. However, the patient was readmitted 12 days later for recurrent symptoms and traumatic catheter removal, requiring nephrostomy tube placement. Follow-up revealed severe bladder and prostate abnormalities, confirming a complex interplay of factors contributing to his infection. P. mendocina is a rare opportunistic pathogen, often occurring in patients with pre-existing health conditions. This case is significant as the first CAUTI caused by P. mendocina and highlights potential links between COVID-19 and increased susceptibility to bacterial infections. The patient's comorbidities, particularly obstructive uropathy, and prolonged catheter use, were likely major factors in his infection. The role of COVID-19 in facilitating bacterial colonization remains speculative but warrants further investigation. This case report underscores the need for heightened clinical awareness and prompt intervention in patients with similar risk factors. The successful treatment regimen provides a valuable reference for managing such infections. Further research is needed to explore the interplay between viral and bacterial infections, particularly in the context of COVID-19.

A Case of Bacterial Keratitis in a Patient Using Orthokeratology and Soft Contact Lenses.

A 63-year-old male with high myopia developed sudden visual loss, eyelid swelling, eye pain, discharge, and tearing in his left eye while wearing soft contact lenses (CLs) during the day and orthokeratology lenses at night. At the initial visit, his corrected visual acuity in the left eye was 20/1000, with a ring-shaped ulcer in the central cornea, corneal infiltration across the entire cornea, and conjunctival hyperemia. Pseudomonas aeruginosa was detected from corneal scrapings, and after antibiotic treatment, the ulcer healed with corneal opacity remaining. On the 60th day, corrected visual acuity of 20/20 was achieved with rigid gas-permeable CLs. To prevent CL-related ocular complications, eye care professionals must carefully evaluate the suitability of all CLs, including orthokeratology.

Innovative Microencapsulation of Polymyxin B for Enhanced Antimicrobial Efficacy via Coated Spray Drying.

This study aims to develop an innovative microencapsulation method for coated Polymyxin B, utilizing various polysaccharides such as hydroxypropyl ß-cyclodextrin, alginate, and chitosan, implemented through a three-fluid nozzle (3FN) spray drying process. High-performance liquid chromatography (HPLC) analysis revealed that formulations with a high ratio of sugar cage, hydroxypropyl ß-cyclodextrin (HPßCD), and sodium alginate (coded as ALGHCDHPLPM) resulted in a notable 16-fold increase in Polymyxin B recovery compared to chitosan microparticles. Morphological assessments using fluorescence labeling confirmed successful microparticle formation with core/shell structures. Alginate-based formulations exhibited distinct layers, while chitosan formulations showed uniform fluorescence throughout the microparticles. Focused beam reflectance and histograms from fluorescence microscopic measurements provided insights into physical size analysis, indicating consistent sizes of 6.8 ± 1.2 µm. Fourier-transform infrared (FTIR) spectra unveiled hydrogen bonding between Polymyxin B and other components within the microparticle structures. The drug release study showed sodium alginate's sustained release capability, reaching 26 ± 3% compared to 94 ± 3% from the free solution at the 24 h time point. Furthermore, the antimicrobial properties of the prepared microparticles against two Gram-negative bacteria, Escherichia coli and Pseudomonas aeruginosa, were investigated. The influence of various key excipients on the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) values was evaluated. Results demonstrated effective bactericidal effects of ALGHCDHPLPM against both E. coli and P. aeruginosa. Additionally, the antibiofilm assay highlighted the potential efficacy of ALGHCDHPLPM against the biofilm viability of E. coli and P. aeruginosa, with concentrations ranging from 3.9 to 500 µg/m. This signifies a significant advancement in antimicrobial drug delivery systems, promising improved precision and efficacy in combating bacterial infections.

Subacute Osteomyelitis of the Symphysis Pubis After Left Oophoritis Caused by Pseudomonas Aeruginosa. A Case Report.

Osteomyelitis of the symphysis pubis is a rarely described bone infection. The main strain of bacteria causing this infection is Staphylococcus aureus, while Pseudomonas aeruginosa is seen most commonly in intravenous drug users. Symmetrical involvement of both pubic bones is usually present. Osteomyelitis of the pubic bones following genital infections in females without a history of previous surgery is very unusual. We present a 47-year-old female patient who, to our best knowledge, is the first case in the literature to develop osteomyelitis of the pubic symphysis after adnexitis caused by Pseudomonas aeruginosa without having had previous surgery in that region.

Ceftazidime/avibactam combined with colistimethate sodium successfully cures carbapenem-resistant Pseudomonas aeruginosa-induced brain abscess in a child post-craniotomy: a case report.

The treatment of brain abscess induced by carbapenem-resistant Pseudomonas aeruginosa (CRPA) is a clinical challenge around the world. Apart from novel ß-lactam/ß-lactamase inhibitors and polymyxins, there are few sufficiently powerful antibiotics that are effective against CRPA-induced infections. Considering the blood-brain barrier factor, there are even fewer drugs that can be used to treat intracranial CRPA-induced infections. In this article, we reported a case of CRPA-induced brain abscess that was successfully treated with intravenous ceftazidime/avibactam and intrathecal colistimethate sodium in a child after intracranial tumor resection.

Molecular investigation of LasA, LasB, and PIV genes in clinical isolates of Pseudomonas aeruginosa in Mazandaran Province, North Iran.

AIMS: Pseudomonasaeruginosa plays an important role in hospital infections caused by several virulence factors, such as elastase and proteases. This study aimed to evaluate the prevalence of LasA, LasB, and PIV genes, encoding these enzymes, in clinical isolates of P.aeruginosa.

Complete genome sequences of three Pseudomonas aeruginosa jumbo bacteriophages discovered in Kenya.

The genomes of three Pseudomonas aeruginosa Phikzvirus bacteriophages isolated in Kenya are described. The genomes of phages vB_PaePAO1-KEN19, vB_Pae3705-KEN49, and vB_Pae10145-KEN51, respectively, had lengths of 278,921, 280,231, and 280,173 bp, with 36.93%, 36.84%, and 36.86% GC content, containing 419, 417, and 417 coding sequences (including seven tRNAs in each genome).