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Letters in Applied Microbiology Jun 2024This study explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using soil bacteria, Pseudomonas otitidis. The bio-synthesized AgNPs were characterized...
This study explores the eco-friendly synthesis of silver nanoparticles (AgNPs) using soil bacteria, Pseudomonas otitidis. The bio-synthesized AgNPs were characterized using various techniques, including UV-visible spectroscopy, Fourier transform infrared (FTIR) spectroscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). UV-visible spectroscopy revealed a distinct broad absorption band in the range of 443 nm, indicating the reduction of silver nitrate to AgNPs. XRD analysis provided evidence of the crystalline nature of the particles, with sharp peaks confirming their crystallinity and an average size of 82.76 nm. FTIR spectroscopy identified extracellular protein compounds as capping agents. SEM examination revealed spherical agglomeration of the crystalline AgNPs. The antimicrobial assay by a disc diffusion method, minimum inhibitory concentration, and minimum bactericidal concentration testing revealed that the biosynthesized AgNPs showed moderate antibacterial activity against both pathogenic Gram-negative (Klebsiella pneumoniae, Pseudomonas aeruginosa, and Acinetobacter baumannii) and Gram-positive (Bacillus cereus, Staphylococcus aureus, and Streptococcus mutans) bacterial strains. Furthermore, the AgNPs significantly disrupted the biofilm of P. aeruginosa, as confirmed by crystal violet assay and fluorescent microscopy. Overall, this study underscores the potential of microbial-synthesized nanoparticles in biomedical applications, particularly in combating pathogenic bacteria, offering a promising avenue for future research and development.
Topics: Silver; Biofilms; Metal Nanoparticles; Anti-Bacterial Agents; Microbial Sensitivity Tests; Pseudomonas; Spectroscopy, Fourier Transform Infrared; X-Ray Diffraction; Pseudomonas aeruginosa
PubMed: 38845375
DOI: 10.1093/lambio/ovae053 -
Microbiology Resource Announcements Mar 2024Here, we report the draft genome sequences of strains zfem001-005, five isolates from the intestinal microbiota of healthy larval zebrafish at a developmental age of 7...
Here, we report the draft genome sequences of strains zfem001-005, five isolates from the intestinal microbiota of healthy larval zebrafish at a developmental age of 7 days post fertilization. The isolates have been identified as , , , , and , respectively.
PubMed: 38376340
DOI: 10.1128/mra.00934-23 -
Journal of Global Antimicrobial... Mar 2024The contamination of fresh surface waters poses a significant burden on human health and prosperity, especially in marginalized communities with limited resources and...
OBJECTIVES
The contamination of fresh surface waters poses a significant burden on human health and prosperity, especially in marginalized communities with limited resources and inadequate infrastructure. Here, we performed in-depth genomic analyses of multidrug-resistant bacteria (MDR-B) isolated from Al-Oueik river water that is used for irrigation of agricultural fields in a disenfranchised area that also hosts a makeshift Syrian refugee camp.
METHODS
A composite freshwater sample was filtered. Faecal coliforms were counted and extended spectrum cephalosporins and/or ertapenem resistant bacteria were screened. Isolates were identified using MALDI-TOF-MS and analysed using whole-genome sequencing (WGS) to identify the resistome, sequence types, plasmid types, and virulence genes.
RESULTS
Approximately 10 CFU/100 mL of faecal coliforms were detected in the water. Four drug-resistant Gram-negative bacteria were identified, namely Escherichia coli, Klebsiella pneumoniae, Enterobacter hormaechei, and Pseudomonas otitidis. Notably, the E. coli isolate harboured bla and a YRIN-inserted PBP3, representing an emerging public health challenge. The K. pneumoniae isolate carried bla as well as mutations in the gene encoding the OmpK37 porin. Enterobacter hormaechei and P. otitidis harboured bla and bla, respectively.
CONCLUSION
This report provides comprehensive genomic analyses of MDR-B in irrigation water in Lebanon. Our results further support that irrigation water contaminated with faecal material can be a reservoir of important MDR-B, which can spread to adjacent agricultural fields and other water bodies, posing both public health and food safety issues. Therefore, there is an urgent need to implement effective water quality monitoring and management programs to control the proliferation of antibiotic-resistant pathogens in irrigation water in Lebanon.
Topics: Humans; Escherichia coli; Rivers; Enterobacter; Plasmids; Klebsiella pneumoniae; Gram-Negative Bacteria
PubMed: 38154747
DOI: 10.1016/j.jgar.2023.12.016 -
BMC Infectious Diseases Dec 2023Pseudomonas otitidis belongs to the genus Pseudomonas and causes various infections, including ear, skin, and soft tissue infections. P. otitidis has a unique... (Review)
Review
BACKGROUND
Pseudomonas otitidis belongs to the genus Pseudomonas and causes various infections, including ear, skin, and soft tissue infections. P. otitidis has a unique susceptibility profile, being susceptible to penicillins and cephalosporins but resistant to carbapenems, due to the production of the metallo-β-lactamase called POM-1. This revealed genetic similarities with Pseudomonas aeruginosa, which can sometimes lead to misidentification.
CASE PRESENTATION
We report the case of a 70-year-old Japanese male who developed cellulitis and bacteremia during chemotherapy for multiple myeloma. He was initially treated with meropenem, but blood culture later revealed gram-negative bacilli identified as P. otitidis using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Carbapenem resistance was predicted from previous reports; therefore, we switched to dual therapy with levofloxacin and cefepime, and favorable treatment results were obtained.
CONCLUSION
This is the first reported case of P. otitidis cellulitis and bacteremia in an immunocompromised patient. Carbapenems are typically used in immunocompromised patients and P. otitidis is often resistant to it. However, its biochemical properties are similar to those of Pseudomonas aeruginosa; therefore, its accurate identification is critical. In the present study, we rapidly identified P. otitidis using MALDI-TOF MS and switched from carbapenems to an appropriate antimicrobial therapy, resulting in a successful outcome.
Topics: Humans; Male; Aged; Anti-Bacterial Agents; Cellulitis; Pseudomonas; Carbapenems; Pseudomonas Infections; Pseudomonas aeruginosa; Bacteremia; Immunocompromised Host; Spectrometry, Mass, Matrix-Assisted Laser Desorption-Ionization
PubMed: 38110897
DOI: 10.1186/s12879-023-08919-0 -
Biologia Futura Sep 2023To study how biofilm-forming rhizobacteria isolated from mines and dumpsites improved the phytoremediation efficacy of B. juncea in metal-contaminated soil. Out of 91...
Biofilm-forming plant growth-promoting rhizobacterial consortia isolated from mines and dumpsites assist green remediation of toxic metal (Ni and Pb) using Brassica juncea.
To study how biofilm-forming rhizobacteria isolated from mines and dumpsites improved the phytoremediation efficacy of B. juncea in metal-contaminated soil. Out of 91 isolates, six were chosen for research based on their tolerance to metals, and their efficient PGPR properties, and subjected to the design of a consortium. A compatibility study revealed no antagonistic interaction between rhizobacterial-consortiums. The results of the biofilm formation and FEG-SEM studies revealed that a consortium-BC8 formed a strong biofilm on the root surface of B. juncea seedlings. Based on results obtained with the phytoextraction efficiency of B. juncea in consortium-BC8 (SMHMZ46 and SMHMP23), they were identified as Klebsiella variicola and Pseudomonas otitidis, respectively, and submitted to NCBI GenBank with accession numbers MZ145092 and OK560623. This rhizobacteria is the first to be reported as assisting Ni and Pb phytoremediation by employing B. juncea. Soil inoculation with consortium-BC8 increased the amount of soluble Ni and Pb by 13.25-fold and 10.69-fold, respectively, when compared to the control. These consortiums-BC8 significantly increased vegetative growth and metal accumulation in root and shoot with a translocation-factor of 1.58 for Ni and soil to root with a bioconcentration-factor of 1.3 for Pb in B. juncea grown in individual soil contamination with 96.05 mg/kg NiCl and 89.63 mg/kg Pb(NO), which are significantly higher than other consortium treatments and the non-inoculated control. B. juncea amendments with a biofilm-forming consortium-BC8 having TF, BCF, and BAC > 1 for Ni, whereas BCF > 1, TF, and BAC < 1 for Pb, are appropriate for green remediation of Ni and phytostabilization of Pb.
PubMed: 37733193
DOI: 10.1007/s42977-023-00179-y -
Journal of Water and Health May 2023Metallo-β-lactamases (MBLs) encoding carbapenem resistance in wastewater are a well-known serious threat to human health. Twelve Pseudomonas otitidis isolates obtained...
Metallo-β-lactamases (MBLs) encoding carbapenem resistance in wastewater are a well-known serious threat to human health. Twelve Pseudomonas otitidis isolates obtained from a municipal wastewater treatment plant (WWTP) in Hawaii were found to possess a subclass B3 MBL - POM (P. otitidis MBL), with a minimum inhibition concentration (MIC) range of 8-16 mg/L. The unrooted neighbor-joining phylogenetic tree showed that these bla genes isolated in wastewater samples (n = 12) were distinctly different from other reference genes isolated from clinical, freshwater, animal, and soil samples except for isolates MR7, MR8, and MR11. MR7, MR8, and MR11 were found to have 4, 3, and 3 amino acid substitutions when compared to the type strain MC10330 and were closely clustered to the clinical reference genes. The meropenem hydrolysis experiment showed that isolates with multiple amino acid substitutions completely hydrolyzed 64 mg/L of meropenem in 7 h. The emergence of the opportunistic pathogen P. otitidis chromosomally encoding bla in the treated municipal wastewater is an alarming call for the spread of this MBL in the environment. Further studies are required to understand the mechanism and regulation of this carbapenem-resistant β-lactamase in order to fill in the knowledge gap.
Topics: Animals; Humans; Carbapenems; Meropenem; Anti-Bacterial Agents; Wastewater; Phylogeny; beta-Lactamases; Microbial Sensitivity Tests; Pseudomonas aeruginosa
PubMed: 37254905
DOI: 10.2166/wh.2023.255 -
Pathogens (Basel, Switzerland) Dec 2022is a rare and unique species among the genus that has not been previously reported as a cause of male genitourinary tract infection. In this report, we describe a case...
is a rare and unique species among the genus that has not been previously reported as a cause of male genitourinary tract infection. In this report, we describe a case of a 20-year-old immunocompetent male who presented with recurrent epididymo-orchitis, which was initially misidentified as Vibrio vulnificus and treated successfully. The causative agent could not be identified appropriately using the available routine methods, but a final identification was established using 16S rRNA targeted sequencing followed by whole-genome sequencing.
PubMed: 36558809
DOI: 10.3390/pathogens11121475 -
Ecotoxicology and Environmental Safety Jan 2023Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various...
Nafion by-product 2 (Nafion BP2), an emerging fluorinated sulfonic acid commonly used in polymer electrolyte membrane technologies, has been detected in various environmental and human matrices. To date, however, few studies have explored its toxicity. In this study, zebrafish embryos were exposed to Nafion BP2 at concentrations of 20, 40, 60, 80, 100, 120, 140, and 160 mg/L from fertilization to 120 post-fertilization (hpf), and multiple developmental parameters (survival rate, hatching rate, and malformation rate) were then determined. Results showed that Nafion BP2 exposure led to a significant decrease in survival and hatching rates and an increase in malformations. The half maximal effective concentration (EC) of Nafion BP2 for malformation at 120 hpf was 55 mg/L, which is higher than the globally important contaminant perfluorooctane sulfonate (PFOS, 6 mg/L). Furthermore, exposure to Nafion BP2 resulted in additional types of malformations compared to PFOS exposure. Pathologically, Nafion BP2 caused abnormal early foregut development, with exfoliation of intestinal mucosa, damage to lamina propria, and aberrant proliferation of lamina propria cells. Nitric oxide content also decreased markedly. In addition, embryos showed an inflammatory response following Nafion BP2 exposure, with significantly increased levels of pro-inflammatory factors C4 and IL-6. Acidic mucin in the hindgut increased more than two-fold. 16 S rRNA sequencing revealed a marked increase in the pathogen Pseudomonas otitidis. Furthermore, pathways involved in intestinal protein digestion and absorption, inflammatory response, and immune response were significantly altered. Our findings suggest that the intestine is a crucial toxicity target of Nafion BP2 in zebrafish, thus highlighting the need to evaluate its health risks.
Topics: Animals; Humans; Embryo, Nonmammalian; Fluorocarbon Polymers; Homeostasis; Intestines; Water Pollutants, Chemical; Zebrafish
PubMed: 36508837
DOI: 10.1016/j.ecoenv.2022.114368 -
Environmental Science and Pollution... Jan 2023Thiram (tetramethylthiuramdisulfide) or thiram sulphide is a dithiocarbamate group of non-systemic group of fungicide which are applied for seed treatment, control of...
Thiram (tetramethylthiuramdisulfide) or thiram sulphide is a dithiocarbamate group of non-systemic group of fungicide which are applied for seed treatment, control of the crop pests, to repel animals, etc. Moreover, thiram has also been responsible to cause moderate skin sensitivity and eye irritation. Higher exposure to thiram might also lead to developmental damages to newborn and neurotoxic effects to non-target organisms. Advancing to prevent such toxic effects and prevention of soil fertility from thiram and thiram-like chemicals is indispensable. The analytical High-Performance Thin-Layer Chromatography (HPTLC) is a simple, quick and a reliable method was proposed and validated for the detection and quantification of various small molecules for many years. This manuscript represents the solution to use microbes to degrade the thiram present in the soil and for that, HPTLC based method to study thiram degradation by Pseudomonas has been designed. Herein, a HPTLC protocol formalised to reveal the detection and quantification of thiram within the range of 100 to 700 ng/spot on TLC plate. The same concentration was then used for calculating percent microbial degradation of thiram from the culture broth. To perform the microbial degradation of thiram, Pseudomonas otitidis strain TD-8 and Pseudomonas stutzeri strain TD-18 were taken as thiram degrader microbial strain. The efficacy of TD-8 to degrade thiram was identified to be 81 and 99% when grown in presence of thiram for 4 days and 8 days, respectively, while TD-18 strain's efficacy to degrade thiram was found to be 57% and 99% when grown in presence of thiram for 4 days and 8 days, respectively.
Topics: Animals; Thiram; Pesticides; Chromatography, Thin Layer; Fungicides, Industrial; Soil
PubMed: 36048383
DOI: 10.1007/s11356-022-22731-4 -
The Journal of Antimicrobial... Aug 2022There is no comprehensive study on PAM-like MBLs.
BACKGROUND
There is no comprehensive study on PAM-like MBLs.
OBJECTIVES
Our aim was to characterize novel B3 MBL variants, PAM-2 and PAM-3, from Pseudomonas tohonis clinical isolates.
METHODS
We evaluated the antimicrobial susceptibility and the MBL gene composition of three novel P. tohonis clinical isolates identified at a Japanese hospital, using the broth microdilution method and WGS, respectively. We characterized the PAM-2 and PAM-3 proteins using recombinant protein expression and biochemical evaluations.
RESULTS
Low carbapenem MICs (meropenem MIC = 0.125-1 mg/L) were observed for all three P. tohonis isolates; however, the isolates produced MBLs. We identified blaPAM-2 and blaPAM-3 as potential genes, belonging to a novel subclass of B3 MBLs. Their genomic sequence was similar to that of blaPAM-1 from Pseudomonas alcaligenes. PAM-2 and PAM-3 comprised 287 amino acids and exhibited 90% amino acid identity with PAM-1, 73% identity with POM-1 from Pseudomonas otitidis and 61% identity with L1 from Stenotrophomonas maltophilia. Biochemical evaluations of recombinant PAM-2 and PAM-3 revealed similar kcat/Km ratios and demonstrated catalytic activity against all the tested β-lactams, except for aztreonam. In addition, the kcat/Km ratio for imipenem was 40-fold lower than that for meropenem.
CONCLUSIONS
P. tohonis harbours a species-specific PAM-family MBL gene. This enzyme has higher hydrolytic activity against meropenem compared with that against imipenem.
Topics: Anti-Bacterial Agents; Humans; Imipenem; Meropenem; Microbial Sensitivity Tests; Pseudomonas; Pseudomonas Infections; Pseudomonas aeruginosa; beta-Lactamases
PubMed: 35786775
DOI: 10.1093/jac/dkac210