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Antimicrobial Resistance and Infection... Jun 2024Stenotrophomonas maltophilia, a multidrug-resistant gram-negative bacteria (GNB), is an emerging nosocomial pathogen. This study assessed the clinical outcomes of GNB...
Gram-negative bacterial infections in surgical intensive care unit patients following abdominal surgery: high mortality associated with Stenotrophomonas maltophilia infection.
BACKGROUND
Stenotrophomonas maltophilia, a multidrug-resistant gram-negative bacteria (GNB), is an emerging nosocomial pathogen. This study assessed the clinical outcomes of GNB infections in surgical intensive care unit (SICU) patients post-abdominal surgery, focusing on the differences between S. maltophilia and other GNBs, including Pseudomonas aeruginosa.
METHODS
A retrospective study was conducted on SICU patients at Kaohsiung Chang Gung Memorial Hospital from 2010 to 2020, who developed GNB infections following abdominal surgery.
RESULTS
Of 442 patients, 237 had S. maltophilia and 205 had non-S. maltophilia GNB infections (including 81 with P. aeruginosa). The overall mortality rate was 44.5%, and S. maltophilia infection emerged as a significant contributor to the mortality rate in patients with GNB infections. S. maltophilia patients had longer mechanical ventilation and SICU stays, with a 30-day mortality rate of 35.4%, higher than the non-S. maltophilia GNB (22.9%) and P. aeruginosa (21%) groups. In-hospital mortality was also higher in the S. maltophilia group (53.2%) compared to the non-S. maltophilia GNB (34.6%) and P. aeruginosa groups (29.6%). Risk factors for acquiring S. maltophilia included a higher Sequential Organ Failure Assessment score and prior broad-spectrum antibiotics use. Older age, polymicrobial infections, and elevated bilirubin were associated with increased 30-day mortality in S. maltophilia patients.
CONCLUSION
S. maltophilia infections in post-abdominal surgery patients are linked to higher mortality than non-S. maltophilia GNB and P. aeruginosa infections, emphasizing the need for early diagnosis and treatment to improve outcomes.
Topics: Humans; Stenotrophomonas maltophilia; Gram-Negative Bacterial Infections; Male; Retrospective Studies; Female; Middle Aged; Intensive Care Units; Aged; Abdomen; Hospital Mortality; Pseudomonas aeruginosa; Adult; Cross Infection; Anti-Bacterial Agents
PubMed: 38886759
DOI: 10.1186/s13756-024-01411-7 -
BMC Complementary Medicine and Therapies Jun 2024Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination....
BACKGROUND
Biofilms and oxidative stress retard wound healing. The resistance of biofilms to antibiotics has led to a search for alternative approaches in biofilm elimination. Antioxidants work synergistically with antibacterial agents against biofilms. Hence recent research has suggested plants as candidates in the development of new alternatives in biofilm treatments and as antioxidants due to the presence of phytocompounds which are responsible for their bioactivities. Hoslundia opposita Vahl is one of the plants used by traditional healers to treat wounds and other infections, this makes it a potential candidate for drug discovery hence, in this study, we investigate the antibiofilm and antioxidant activity of methanolic extract of hoslundia opposita Vahl from Uganda. We also identify phytochemicals responsible for its bioactivity.
METHOD
the plant was extracted by maceration using methanol, and the extract was investigated for antioxidant activity using 2,2-diphenyl-1-picrylhydrazyl radical (DPPH) assay. The antibiofilm activity using microtiter plate assay (MTP) assay where the Minimum biofilm inhibitory concentration required to inhibit 50% or 90% of the biofilm (MBIC and MBIC) and Minimum biofilm eradication concentration required to remove 50% or 90% of the biofilm (MBEC and MBEC) were measured. It was further analysed for its phytochemical composition using quantitative screening, as well as Gas chromatography-mass spectrometry (GC-MS) and Liquid chromatography mass-spectrometry (LC-MS).
RESULTS
H. Opposita Vahl extract showed good antioxidant activity with of 249.6 mg/mL. It inhibited the growth of P. aeruginosa and S. aureus biofilms with MBIC of 28.37 mg/mL and 10 mg/mL, respectively. It showed the ability to eradicate P. aeruginosa and S. aureus biofilms with MBEC of 23.85 and 39.01 mg/mL respectively. Phytochemical analysis revealed the presence of alkaloids, tannins, flavonoids, and phenols. GC-MS analysis revealed 122 compounds in the extract of which, 23 have evidence of antioxidant or antibiofilm activity in literature. The most abundant compounds were; 1,4- Citric acid, Tetracontane-1,40-diol (43.43.3%, 1, Olean-12-en-28-oic acid, 3-hydroxy-, methyl ester, (3.beta) (15.36%) 9-Octadecenamide (12.50%), Squalene (11.85%) Palmitic Acid 4TMS (11.28%), and alpha Amyrin (11.27%). The LC-MS identified 115 and 57 compounds in multiple reaction mode (MRM) and scan modes respectively.
CONCLUSION
H. opposita Vahl showed antibiofilm and antioxidant activity due to bioactive compounds identified, hence the study justifies its use for wound healing. It can be utilised in further development of new drugs as antibiofilm and antioxidants.
Topics: Biofilms; Antioxidants; Plant Extracts; Wound Healing; Anti-Bacterial Agents; Pseudomonas aeruginosa; Microbial Sensitivity Tests; Uganda; Staphylococcus aureus; Humans; Phytochemicals
PubMed: 38886717
DOI: 10.1186/s12906-024-04540-z -
BMC Microbiology Jun 2024Addressing microbial resistance urgently calls for alternative treatment options. This study investigates the impact of a bimetallic formulation containing colistin,...
BACKGROUND
Addressing microbial resistance urgently calls for alternative treatment options. This study investigates the impact of a bimetallic formulation containing colistin, silver, and copper oxide on a pandrug-resistant, highly virulent Pseudomonas aeruginosa (P. aeruginosa) isolate from a cancer patient at the National Cancer Institute, Cairo University, Egypt.
METHODS
Silver nanoparticles (Ag NPs), copper oxide nanoparticles (CuO NPs), and bimetallic silver-copper oxide nanoparticles (Ag-CuO NPs) were synthesized using gamma rays, combined with colistin (Col), and characterized by various analytical methods. The antimicrobial activity of Col-Ag NPs, Col-CuO NPs, and bimetallic Col-Ag-CuO NPs against P. aeruginosa was evaluated using the agar well diffusion method, and their minimum inhibitory concentration (MIC) was determined using broth microdilution. Virulence factors such as pyocyanin production, swarming motility, and biofilm formation were assessed before and after treatment with bimetallic Col-Ag-CuO NPs. The in vivo efficacy was evaluated using the Galleria mellonella model, and antibacterial mechanism were examined through membrane leakage assay.
RESULTS
The optimal synthesis of Ag NPs occurred at a gamma ray dose of 15.0 kGy, with the highest optical density (OD) of 2.4 at 375 nm. Similarly, CuO NPs had an optimal dose of 15.0 kGy, with an OD of 1.5 at 330 nm. Bimetallic Ag-CuO NPs were most potent at 15.0 kGy, yielding an OD of 1.9 at 425 nm. The MIC of colistin was significantly reduced when combined with nanoparticles: 8 µg/mL for colistin alone, 0.046 µg/mL for Col-Ag NPs, and 0.0117 µg/mL for Col-Ag-CuO NPs. Bimetallic Col-Ag-CuO NPs reduced the MIC four-fold compared to Col-Ag NPs. Increasing the sub-inhibitory concentration of bimetallic nanoparticles from 0.29 × 10 to 0.58 × 10 µg/mL reduced P. aeruginosa swarming by 32-64% and twitching motility by 34-97%. At these concentrations, pyocyanin production decreased by 39-58%, and biofilm formation was inhibited by 33-48%. The nanoparticles were non-toxic to Galleria mellonella, showing 100% survival by day 3, similar to the saline-treated group.
CONCLUSIONS
The synthesis of bimetallic Ag-CuO NPs conjugated with colistin presents a promising alternative treatment for combating the challenging P. aeruginosa pathogen in hospital settings. Further research is needed to explore and elucidate the mechanisms underlying the inhibitory effects of colistin-bimetallic Ag-CuO NPs on microbial persistence and dissemination.
Topics: Pseudomonas aeruginosa; Colistin; Copper; Anti-Bacterial Agents; Microbial Sensitivity Tests; Silver; Animals; Metal Nanoparticles; Biofilms; Pseudomonas Infections; Drug Resistance, Multiple, Bacterial; Humans; Moths; Virulence Factors; Egypt
PubMed: 38886632
DOI: 10.1186/s12866-024-03358-6 -
Journal of Hazardous Materials Aug 2024Effective treatment of industrial wastewater containing complex pollutants, such as nitrate (NO-N) and organic pollutants, remains a significant challenge to date. Here,...
Enhanced denitrification and p-nitrophenol removal performance via hydrophilic sponge carriers fixed with dual-bacterial: Optimization, performance, and enhancement mechanism.
Effective treatment of industrial wastewater containing complex pollutants, such as nitrate (NO-N) and organic pollutants, remains a significant challenge to date. Here, a strain Nocardioides sp. ZS2 with denitrification and degradation of p-nitrophenol (PNP) was isolated and its culture conditions were optimized by kinetic analysis. Hydrophilic sponge carriers were prepared using polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC), and chitosan (CS) to construct bioreactors. Furthermore, to further enhance the PNP degradation and denitrification performance of bioreactors, Pseudomonas stutzeri GF2 with denitrification capability was introduced. The results revealed that the removal efficiencies of PNP and NO-N reached 97.9 % and 91.9 %, respectively, when hydraulic retention time (HRT) of 6 h, C/N of 2.0, and pH of 6.5. The bioreactor exhibited stable denitrification performance even with fluctuations in the influent PNP concentration. The potential functional prediction results revealed that the abundance of amino acids, fatty acids, and carbohydrates increased as the influent C/N decreased, reflecting a tendency of the microbial community to adjust carbon source utilization to maintain cell growth, metabolic balance, and resist adverse C/N environments. This research provides new insights into the effective removal of organic pollutants and NO-N in wastewater treatment.
Topics: Nitrophenols; Bioreactors; Denitrification; Water Pollutants, Chemical; Hydrophobic and Hydrophilic Interactions; Chitosan; Pseudomonas stutzeri; Polyvinyl Alcohol; Carboxymethylcellulose Sodium; Biodegradation, Environmental; Nitrates; Wastewater; Actinobacteria; Waste Disposal, Fluid
PubMed: 38885589
DOI: 10.1016/j.jhazmat.2024.134922 -
Microbial Biotechnology Jun 2024Pathogens resistant to classical control strategies pose a significant threat to crop yield, with seeds being a major transmission route. Bacteriophages, viruses...
Pathogens resistant to classical control strategies pose a significant threat to crop yield, with seeds being a major transmission route. Bacteriophages, viruses targeting bacteria, offer an environmentally sustainable biocontrol solution. In this study, we isolated and characterized two novel phages, Athelas and Alfirin, which infect Pseudomonas syringae and Agrobacterium fabrum, respectively, and included the recently published Pfeifenkraut phage infecting Xanthomonas translucens. Using a simple immersion method, phages coated onto seeds successfully lysed bacteria post air-drying. The seed coat mucilage (SCM), a polysaccharide-polymer matrix exuded by seeds, plays a critical role in phage binding. Seeds with removed mucilage formed five to 10 times less lysis zones compared to those with mucilage. The podovirus Athelas showed the highest mucilage dependency. Phages from the Autographiviridae family also depended on mucilage for seed adhesion. Comparative analysis of Arabidopsis SCM mutants suggested the diffusible cellulose as a key component for phage binding. Long-term activity tests demonstrated high phage stability on seed surfaces and significantly increasing seedling survival rates in the presence of pathogens. Using non-virulent host strains enhanced phage presence on seeds but also has potential limitations. These findings highlight phage-based interventions as promising, sustainable strategies for combating pathogen resistance and improving crop yield.
Topics: Seeds; Pseudomonas syringae; Plant Diseases; Bacteriophages; Arabidopsis; Xanthomonas; Plant Mucilage; Biological Control Agents; Virus Attachment
PubMed: 38884488
DOI: 10.1111/1751-7915.14507 -
The Israel Medical Association Journal... Jun 2024Pseudomonas aeruginosa (PSA) is an infectious pathogen associated with acute appendicitis; however, it is not consistently addressed by empirical antibiotic therapy,...
BACKGROUND
Pseudomonas aeruginosa (PSA) is an infectious pathogen associated with acute appendicitis; however, it is not consistently addressed by empirical antibiotic therapy, despite potential complications.
OBJECTIVES
To investigate the incidence, predictors, and outcomes of PSA-associated acute appendicitis in children.
METHODS
We conducted a retrospective analysis involving pediatric patients who underwent acute appendicitis surgery and had positive peritoneal cultures. Clinical, microbiological, and intraoperative data were extracted from medical records.
RESULTS
Among 2523 children with acute appendicitis, 798 (31.6%) underwent peritoneal cultures, revealing 338 positive cases (42.3%), with PSA detected in 77 cases (22.8%). Children with PSA were three times more likely to exhibit high intraoperative grading ≥ 3 (93.4% vs. 76.8%, 95% confidence interval [95%CI] 1.2-8.3, P = 0.023) and nearly four times more likely to have polymicrobial cultures (88.3% vs. 62.1%, 95%CI 1.8-8.0, P < 0.001) than those without PSA in peritoneal cultures. Duration of symptoms did not predict PSA isolation (P = 0.827). Patients with PSA had longer median hospital stays (8 days, interquartile range [IQR] 7-10) than those with other pathogens (7 days, IQR 5-9) (P = 0.004). Antibiotic treatment duration, intensive care unit admission rates, readmission, and mortality were similar between the two groups (P = 0.893, 0.197, 0.760, and 0.761, respectively).
CONCLUSIONS
PSA is a common pathogen in children diagnosed with acute appendicitis and positive peritoneal cultures. The likelihood of isolating PSA increases with high-grade intraoperative assessment and in the presence of multiple pathogens in peritoneal cultures, suggests antipseudomonal treatment.
Topics: Humans; Appendicitis; Female; Pseudomonas aeruginosa; Child; Retrospective Studies; Male; Pseudomonas Infections; Incidence; Anti-Bacterial Agents; Length of Stay; Appendectomy; Acute Disease; Israel; Adolescent; Child, Preschool
PubMed: 38884308
DOI: No ID Found -
The Journal of the Association of... Apr 2024is a rare pathogen that primarily causes nosocomial infection. It is usually seen in immune dysfunction or immunocompromised patients and patients with invasive medical...
is a rare pathogen that primarily causes nosocomial infection. It is usually seen in immune dysfunction or immunocompromised patients and patients with invasive medical devices. Here, we present a rare case of bacteremia in a patient with cirrhosis of the liver.
Topics: Humans; Bacteremia; Pseudomonas putida; Liver Cirrhosis; Pseudomonas Infections; Male; Anti-Bacterial Agents; Middle Aged
PubMed: 38881090
DOI: 10.59556/japi.72.0416 -
Pesticide Biochemistry and Physiology Jun 2024ε-Poly-l-lysine (ε-PL) is an effective antimicrobial peptide for controlling fungal plant diseases, exhibiting significant antifungal activity and safety. Despite its...
ε-Poly-l-lysine (ε-PL) is an effective antimicrobial peptide for controlling fungal plant diseases, exhibiting significant antifungal activity and safety. Despite its known efficacy, the potential of ε-PL in combating plant bacterial diseases remains underexplored. This study evaluated the effectiveness of ε-PL and its nanomaterial derivative in managing tomato bacterial spot disease caused by Pseudomonas syringae pv. tomato. Results indicated that ε-PL substantially inhibited the growth of Pseudomonas syringae pv. tomato. Additionally, when ε-PL was loaded onto attapulgite (encoded as ATT@PL), its antibacterial effect was significantly enhanced. Notably, the antibacterial efficiency of ATT@PL containing 18.80 μg/mL ε-PL was even close to that of 100 μg/mL pure ε-PL. Further molecular study results showed that, ATT@PL stimulated the antioxidant system and the salicylic acid signaling pathway in tomatoes, bolstering the plants disease resistance. Importantly, the nanocomposite demonstrated no negative effects on both seed germination and plant growth, indicating its safety and aligning with sustainable agricultural practices. This study not only confirmed the effectiveness of ε-PL in controlling tomato bacterial spot disease, but also introduced an innovative high antibacterial efficiency ε-PL composite with good bio-safety. This strategy we believe can also be used in improving other bio-pesticides, and has high applicability in agriculture practice.
Topics: Pseudomonas syringae; Solanum lycopersicum; Polylysine; Anti-Bacterial Agents; Plant Diseases; Silicon Compounds; Magnesium Compounds
PubMed: 38879341
DOI: 10.1016/j.pestbp.2024.105959 -
Ecotoxicology and Environmental Safety Jul 2024Simultaneous heterotrophic nitrification and aerobic denitrification (SND) is gaining tremendous attention due to its high efficiency and low cost in water treatment....
Simultaneous heterotrophic nitrification and aerobic denitrification (SND) is gaining tremendous attention due to its high efficiency and low cost in water treatment. However, SND on an industrial scale is still immature since effects of coexisting pollutants, for example, heavy metals, on nitrogen removal remains largely unresolved. In this study, a HNAD bacterium (Pseudomonas sp. XF-4) was isolated. It could almost completely remove ammonium and nitrate at pH 5-9 and temperature 20 ℃-35 ℃ within 10 h, and also showed excellently simultaneous nitrification and denitrification efficiency under the coexistence of any two of inorganic nitrogen sources with no intermediate accumulation. XF-4 could rapidly grow again after ammonium vanish when nitrite or nitrate existed. There was no significant effects on nitrification and denitrification when Cd(II) was lower than 10 mg/L, and 95 % of Cd(II) was removed by XF-4. However, electron carrier and electron transport system activity was inhibited, especially at high concentration of Cd(II). Overall, this study reported a novel strain capable of simultaneous nitrification and denitrification coupled with Cd(II) removal efficiently. The results provided new insights into treatment of groundwater or wastewater contaminated by heavy metals and nitrogen.
Topics: Cadmium; Denitrification; Nitrification; Pseudomonas; Water Pollutants, Chemical; Nitrogen; Heterotrophic Processes; Nitrates; Wastewater; Biodegradation, Environmental; Aerobiosis; Water Purification; Ammonium Compounds
PubMed: 38878332
DOI: 10.1016/j.ecoenv.2024.116588 -
Nature Communications Jun 2024Tomato (Solanum lycopersicum) is one of the world's most important food crops, and as such, its production needs to be protected from infectious diseases that can...
Tomato (Solanum lycopersicum) is one of the world's most important food crops, and as such, its production needs to be protected from infectious diseases that can significantly reduce yield and quality. Here, we survey the effector-triggered immunity (ETI) landscape of tomato against the bacterial pathogen Pseudomonas syringae. We perform comprehensive ETI screens in five cultivated tomato varieties and two wild relatives, as well as an immunodiversity screen on a collection of 149 tomato varieties that includes both wild and cultivated varieties. The screens reveal a tomato ETI landscape that is more limited than what was previously found in the model plant Arabidopsis thaliana. We also demonstrate that ETI eliciting effectors can protect tomato against P. syringae infection when the effector is delivered by a non-virulent strain either prior to or simultaneously with a virulent strain. Overall, our findings provide a snapshot of the ETI landscape of tomatoes and demonstrate that ETI can be used as a biocontrol treatment to protect crop plants.
Topics: Solanum lycopersicum; Pseudomonas syringae; Plant Diseases; Plant Immunity; Arabidopsis; Plant Proteins; Virulence; Gene Expression Regulation, Plant; Bacterial Proteins
PubMed: 38877009
DOI: 10.1038/s41467-024-49425-4