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Molecular Biotechnology Nov 2023Proteus penneri (P. penneri) is a bacillus-shaped, gram-negative, facultative anaerobe bacterium that is primarily an invasive pathogen and the etiological agent of...
Proteus penneri (P. penneri) is a bacillus-shaped, gram-negative, facultative anaerobe bacterium that is primarily an invasive pathogen and the etiological agent of several hospital-associated infections. P. penneri strains are naturally resistant to macrolides, amoxicillin, oxacillin, penicillin G, and cephalosporins; in addition, no vaccines are available against these strains. This warrants efforts to propose a theoretical based multi-epitope vaccine construct to prevent pathogen infections. In this research, reverse vaccinology bioinformatics and immunoinformatics approaches were adopted for vaccine target identification and construction of a multi-epitope vaccine. In the first phase, a core proteome dataset of the targeted pathogen was obtained using the NCBI database and subjected to bacterial pan-genome analysis using bacterial pan-genome analysis (BPGA) to predict core protein sequences which were then used to find good vaccine target candidates. This identified two proteins, Hcp family type VI secretion system effector and superoxide dismutase family protein, as promising vaccine targets. Afterward using the IEDB database, different B-cell and T-cell epitopes were predicted. A set of four epitopes "KGSVNVQDRE, NTGKLTGTR, IIHSDSWNER, and KDGKPVPALK" were chosen for the development of a multi-epitope vaccine construct. A 183 amino acid long vaccine design was built along with "EAAAK" and "GPGPG" linkers and a cholera toxin B-subunit adjuvant. The designed vaccine model comprised immunodominant, non-toxic, non-allergenic, and physicochemical stable epitopes. The model vaccine was docked with MHC-I, MHC-II, and TLR-4 immune cell receptors using the Cluspro2.0 web server. The binding energy score of the vaccine was - 654.7 kcal/mol for MHC-I, - 738.4 kcal/mol for MHC-II, and - 695.0 kcal/mol for TLR-4. A molecular dynamic simulation was done using AMBER v20 package for dynamic behavior in nanoseconds. Additionally, MM-PBSA binding free energy analysis was done to test intermolecular binding interactions between docked molecules. The MM-GBSA net binding energy score was - 148.00 kcal/mol, - 118.00 kcal/mol, and - 127.00 kcal/mol for vaccine with TLR-4, MHC-I, and MHC-II, respectively. Overall, these in silico-based predictions indicated that the vaccine is highly promising in terms of developing protective immunity against P. penneri. However, additional experimental validation is required to unveil the real immune response to the designed vaccine.
PubMed: 37934390
DOI: 10.1007/s12033-023-00949-y -
Journal of Applied Microbiology Jan 2024The present study investigated the anti-virulence and anti-biofilm effects of 1,2,6-tri-O-galloyl-β-ᴅ-glucose (TGG), isolated from Camellia nitidissima Chi flowers,...
AIMS
The present study investigated the anti-virulence and anti-biofilm effects of 1,2,6-tri-O-galloyl-β-ᴅ-glucose (TGG), isolated from Camellia nitidissima Chi flowers, on Proteus penneri ALK 1200.
METHODS AND RESULTS
TGG was isolated from C. nitidissima Chi flowers using various chromatographic techniques. The milk plate assay, azocasein assay, and exopolysaccharides (EPS) inhibition assay revealed that TGG effectively inhibited the production of crucial virulence factors, including protease and EPS, in P. penneri ALK 1200. Furthermore, fourier transform infrared spectroscopic (FT-IR) analysis indicated that TGG interfered with the composition of P. penneri ALK 1200's cellular component, potentially reducing the bacteria's pathogenicity. In addition, crystal violet assay, scanning electron microscopy (SEM), and confocal laser scanning microscopy (CLSM) analysis indicated a significant reduction in biofilm formation following TGG treatment. The swimming and swarming assays also showed that TGG reduced the motility of P. penneri ALK 1200. Furthermore, the qRT-PCR assay demonstrated that TGG down-regulated the expression of positive regulatory genes (hfq and flhD) responsible for motility and biofilm formation, while up-regulating the expression of the negative regulator of the quorum sensing system, bssS, in P. penneri ALK 1200.
CONCLUSIONS
TGG displayed potent anti-QS and anti-biofilm activity towards P. penneri ALK 1200.
PubMed: 38200708
DOI: 10.1093/jambio/lxae004 -
Diagnostic Microbiology and Infectious... Jun 2024Although Proteus species are occasional causes of serious infections, their epidemiology has not been well defined. The objective was to describe the overall and... (Comparative Study)
Comparative Study
BACKGROUND
Although Proteus species are occasional causes of serious infections, their epidemiology has not been well defined. The objective was to describe the overall and species-specific occurrence and determinants of Proteus species bloodstream infection (BSI) in a large Australian population.
METHODS
All Queensland residents with Proteus species BSI identified within the publicly funded healthcare system between 2000 and 2019 were included.
RESULTS
A total of 2,143 incident episodes of Proteus species BSI were identified among 2,079 Queensland residents. The prevalence of comorbid illness differed with higher Charlson comorbidity scores observed with P. penneri and P. vulgaris, and higher prevalence of liver disease with P. penneri, higher comorbid cancer with P. vulgaris, and lower diabetes and renal disease prevalence with P. mirabilis BSIs.
CONCLUSION
This study provides novel information on the epidemiology of Proteus species BSI.
Topics: Humans; Bacteremia; Male; Middle Aged; Female; Proteus Infections; Aged; Queensland; Proteus; Prevalence; Adult; Comorbidity; Aged, 80 and over; Young Adult; Proteus mirabilis
PubMed: 38574445
DOI: 10.1016/j.diagmicrobio.2024.116286 -
Chemistry & Biodiversity Apr 2024Ruta chalepensis L. is a versatile herb used in culinary arts and traditional medicine. The study aimed to determine the chemical composition of an ethanolic extract...
Ruta chalepensis L. is a versatile herb used in culinary arts and traditional medicine. The study aimed to determine the chemical composition of an ethanolic extract from R. chalepensis and the total phenolic and flavonoid content. Additionally, the extracts' antimicrobial and antioxidant activities were tested. The disc diffusion method and minimum inhibitory concentration (MIC) were used to test the antibacterial properties on four types of bacteria: Escherichia coli, Proteus penneri, Bacillus cereus, and Staphylococcus aureus. A colorimetric assay was used to evaluate the total phenolic and flavonoid content, and the DPPH method was used to assess the antioxidant activity. The phytochemical constituents were determined using LC-MS/MS. The results indicated that R. chalepensis ethanolic extract had 34 compounds, and the predominant compounds were quercetin (9.2 %), myricetin (8.8 %), and camphene (8.0 %). Moreover, the extract had a good level of polyphenols and flavonoids, as demonstrated by inhibiting free radicals (DPPH) (IC was 41.2±0.1). Also, the extract exhibited robust antimicrobial activity against P. penneri and S. aureus with an MIC of 12.5 and 25.0 μg/mL, respectively. In conclusion, the results suggest that the R. chalepensis ethanolic extract has good antioxidant and antibacterial properties that could be utilized to develop new antibacterial agents.
Topics: Anti-Bacterial Agents; Anti-Infective Agents; Antioxidants; Chromatography, Liquid; Ethanol; Flavonoids; Phenols; Plant Extracts; Ruta; Staphylococcus aureus; Tandem Mass Spectrometry; Polyphenols; Quercetin
PubMed: 38372467
DOI: 10.1002/cbdv.202400026 -
Environmental Pollution (Barking, Essex... Nov 2023This study investigates the size distribution, microbial composition, and antibiotic resistance (ABR) of airborne bioaerosols at a suburban location in Doha, Qatar...
This study investigates the size distribution, microbial composition, and antibiotic resistance (ABR) of airborne bioaerosols at a suburban location in Doha, Qatar between October 2021 and January 2022. Samples were collected using an Andersen six-stage viable cascade impactor and a liquid impinger. Findings showed that the mean bacteria concentration (464 CFU/m) was significantly higher than that of fungi (242 CFU/m) during the study period. Both bacteria and fungi were most abundant in the aerodynamic size fractions of 1.10-2.21 μm, with peak concentrations observed in the mornings and lowest concentrations in the afternoons across all size fractions. A total of 24 different culturable species were identified, with the most abundant ones being Pasteurella pneumotropica (9.71%), Pantoea spp. 1 (8.73%), and Proteus penneri (7.77%) spp. At the phylum level, the bacterial community configurations during the autumn and winter seasons were nearly identical as revealed by molecular genomics, with Proteobacteria being the most predominant, followed by Firmicutes, Bacteroidetes, Acidobacteriota, and Planctomycetota. However, there was a significant variation in dominant genera between autumn and winter. The most abundant genera included Sphingomonas, Paraburkholderia, Comamonas, Bacillus, and Lysinibacillus. Several bacterial genera identified in this study have important public health and ecological implications, including the risk of respiratory tract infections. Furthermore, the study found that ABR was highest in December, with bioaerosols exhibiting resistance to at least 5 out of 10 antibiotics, and 100% resistance to Metronidazole in all samples. Metagenomics analysis revealed the presence of various airborne bacteria that were not detected through culture-dependent methods. This study provides valuable insights into the airborne microbial composition, temporal variability and ABR in the Arabian Gulf region.
PubMed: 37598930
DOI: 10.1016/j.envpol.2023.122401