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Ecotoxicology and Environmental Safety Jun 2024Cadmium (Cd) pollution is a serious global environmental problem, which requires a global concern and practical solutions. Microbial remediation has received widespread...
Cadmium (Cd) pollution is a serious global environmental problem, which requires a global concern and practical solutions. Microbial remediation has received widespread attention owing to advantages, such as environmental friendliness and soil amelioration. However, Cd toxicity also severely deteriorates the remediation performance of functional microorganisms. Analyzing the mechanism of bacterial resistance to Cd stress will be beneficial for the application of Cd remediation. In this study, the bacteria strain, up to 1400 mg/L Cd resistance, was employed and identified as Proteus mirabilis Ch8 (Ch8) through whole genome sequence analyses. The results indicated that the multiple pathways of immobilizing and detoxifying Cd maintained the growth of Ch8 under Cd stress, which also possessed high Cd extracellular adsorption. Firstly, the changes in surface morphology and functional groups of Ch8 cells were observed under different Cd conditions through SEM-EDS and FTIR analyses. Under 100 mg/L Cd, Ch8 cells exhibited aggregation and less flagella; the Cd biosorption of Ch8 was predominately by secreting exopolysaccharides (EPS) and no significant change of functional groups. Under 500 mg/L Cd, Ch8 were present irregular polymers on the cell surface, some cells with wrapping around; the Cd biosorption capacity exhibited outstanding effects (38.80 mg/g), which was mainly immobilizing Cd by secreting and interacting with EPS. Then, Ch8 also significantly enhanced the antioxidant enzyme activity and the antioxidant substance content under different Cd conditions. The activities of SOD and CAT, GSH content of Ch8 under 500 mg/L Cd were significantly increased by 245.47%, 179.52%, and 241.81%, compared to normal condition. Additionally, Ch8 significantly induced the expression of Acr A and Tol C (the resistance-nodulation-division (RND) efflux pump), and some antioxidant genes (SodB, SodC, and Tpx) to reduce Cd damage. In particular, the markedly higher expression levels of SodB under Cd stress. The mechanism of Ch8 lays a foundation for its application in solving soil remediation.
Topics: Proteus mirabilis; Cadmium; Soil Pollutants; Biodegradation, Environmental
PubMed: 38728947
DOI: 10.1016/j.ecoenv.2024.116432 -
Sensors (Basel, Switzerland) Sep 2023Bacterial resistance to antibiotics is a primary global healthcare concern as it hampers the effectiveness of commonly used antibiotics used to treat infectious...
Bacterial resistance to antibiotics is a primary global healthcare concern as it hampers the effectiveness of commonly used antibiotics used to treat infectious diseases. The development of bacterial resistance continues to escalate over time. Rapid identification of the infecting bacterium and determination of its antibiotic susceptibility are crucial for optimal treatment and can save lives in many cases. Classical methods for determining bacterial susceptibility take at least 48 h, leading physicians to resort to empirical antibiotic treatment based on their experience. This random and excessive use of antibiotics is one of the most significant drivers of the development of multidrug-resistant (MDR) bacteria, posing a severe threat to global healthcare. To address these challenges, considerable efforts are underway to reduce the testing time of taxonomic classification of the infecting bacterium at the species level and its antibiotic susceptibility determination. Infrared spectroscopy is considered a rapid and reliable method for detecting minor molecular changes in cells. Thus, the main goal of this study was the use of infrared spectroscopy to shorten the identification and the susceptibility testing time of and from 48 h to approximately 40 min, directly from patients' urine samples. It was possible to identify the and species with 99% accuracy and, simultaneously, to determine their susceptibility to different antibiotics with an accuracy exceeding 80%.
Topics: Humans; Pseudomonas; Microbial Sensitivity Tests; Proteus; Bacteria; Bacterial Infections; Anti-Bacterial Agents; Spectrophotometry, Infrared; Machine Learning; Urinary Tract Infections
PubMed: 37836961
DOI: 10.3390/s23198132 -
Trends in Microbiology Apr 2017Proteus mirabilis is a model organism for urease-producing uropathogens. These diverse bacteria cause infection stones in the urinary tract and form crystalline biofilms... (Review)
Review
Proteus mirabilis is a model organism for urease-producing uropathogens. These diverse bacteria cause infection stones in the urinary tract and form crystalline biofilms on indwelling urinary catheters, frequently leading to polymicrobial infection. Recent work has elucidated how P. mirabilis causes all of these disease states. Particularly exciting is the discovery that this bacterium forms large clusters in the bladder lumen that are sites for stone formation. These clusters, and other steps of infection, require two virulence factors in particular: urease and MR/P fimbriae. Highlighting the importance of MR/P fimbriae is the cotranscribed regulator, MrpJ, which globally controls virulence. Overall, P. mirabilis exhibits an extraordinary lifestyle, and further probing will answer exciting basic microbiological and clinically relevant questions.
Topics: Bacterial Proteins; Biofilms; Catheter-Related Infections; Fimbriae, Bacterial; Humans; Kidney Calculi; Proteus Infections; Proteus mirabilis; Repressor Proteins; Urease; Urinary Bladder; Urinary Tract Infections
PubMed: 28017513
DOI: 10.1016/j.tim.2016.11.015 -
PloS One 2023Proteus mirabilis is an opportunistic pathogen associated with a variety of human infections, including urinary tract infections. The prevalence of P. mirabilis in foods...
Proteus mirabilis is an opportunistic pathogen associated with a variety of human infections, including urinary tract infections. The prevalence of P. mirabilis in foods of animal origin and in the manure by-products created in animal production is not well documented. Further, the prevalence and persistence of extended-spectrum cephalosporin (ESC) resistant P. mirabilis is largely unknown. In this study, we characterized ESC-resistant P. mirabilis recovered from various stages of dairy manure anaerobic digestion. Isolates were screened by PCR for blaCTX-M, blaCMY and blaSHV, and antimicrobial susceptibility testing was performed. Fifty-six P. mirabilis carrying CTX-M were sequenced with short and long read sequencing technologies, and the assembled chromosomes and plasmids were compared. ESC-resistant Proteus was found in four of the six manure digesters, an indication that not all digesters were colonized with resistant strains. Both CTX-M-1 and CTX-M-15 plasmids were found in P. mirabilis isolates. Transfer of plasmid DNA by conjugation was also explored, with ESC-resistance plasmids able to transfer to Escherichia coli at high frequency. We concluded that P. mirabilis can harbour and transfer ESC-resistance genes and plasmids, and may be an overlooked reservoir of antimicrobial resistance.
Topics: Animals; Cattle; Humans; Proteus mirabilis; Manure; Anaerobiosis; Cephalosporins; Escherichia coli; Plasmids; beta-Lactamases; Anti-Infective Agents; Anti-Bacterial Agents
PubMed: 37561682
DOI: 10.1371/journal.pone.0289703 -
Journal of Orthopaedic Research :... Apr 2020While Gram-positive organisms are the most common causative agent of initial bone infections, the percentage of Gram-negative species increases in reoccurring bone...
While Gram-positive organisms are the most common causative agent of initial bone infections, the percentage of Gram-negative species increases in reoccurring bone infections. As bacterial internalization has been suggested as one cause of reoccurring bone infection, we tested the hypothesis that Gram-negative species of bacteria can be internalized into bone cells. Using the MLO-A5 and the MLO-Y4 cell lines as our cell models, we demonstrated that the Gram-negative species, Proteus mirabilis and Serratia marcescens, can be internalized in these cells using an internalization assay. This rate at which these two species were internalized was both time- and initial concentration-dependent. Confocal analysis demonstrated the presence of internalized bacteria within both cell types. Inhibition of the cellular uptake with methyl-β-cyclodextrin and chloroquine both reduced internalized bacteria, indicating that this process is, at least in part, cell mediated. Finally, we demonstrated that the presence of internalized P. mirabilis did not impact cell viability, measured either by lactate dehydrogenase (LDH) release or 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) activity, while the presence of S. marcescens, on the other hand, both increased LDH release and reduced MTT activity, indicating a loss of cell viability in response to the organism. These results indicated that both species of Gram-negative bacteria can be internalized by bone cells and that these internalized bacteria could potentially result in reoccurring bone infections. © 2019 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 38:861-870, 2020.
Topics: Animals; Cell Line; Endocytosis; Host-Pathogen Interactions; Mice; Microscopy, Confocal; Osteocytes; Proteus mirabilis; Serratia marcescens
PubMed: 31692074
DOI: 10.1002/jor.24510 -
BMC Microbiology Jun 2020Members of the genus Proteus are mostly opportunistic pathogens that cause a variety of infections in humans. The molecular evolutionary characteristics and genetic...
Multilocus sequence analysis for the taxonomic updating and identification of the genus Proteus and reclassification of Proteus genospecies 5 O'Hara et al. 2000, Proteus cibarius Hyun et al. 2016 as later heterotypic synonyms of Proteus terrae Behrendt et al. 2015.
BACKGROUND
Members of the genus Proteus are mostly opportunistic pathogens that cause a variety of infections in humans. The molecular evolutionary characteristics and genetic relationships among Proteus species have not been elucidated to date. In this study, we developed a multilocus sequence analysis (MLSA) approach based on five housekeeping genes (HKGs) to delineate phylogenetic relationships of species within the genus Proteus.
RESULTS
Of all 223 Proteus strains collected in the current study, the phylogenetic tree of five concatenated HKGs (dnaJ, mdh, pyrC, recA and rpoD) divided 223 strains into eleven clusters, which were representative of 11 species of Proteus. Meanwhile, the phylogenetic trees of the five individual HKGs also corresponded to that of the concatenated tree, except for recA, which clustered four strains at an independent cluster. The evaluation of inter- and intraspecies distances of HKG concatenation indicated that all interspecies distances were significantly different from intraspecies distances, which revealed that these HKG concatenations can be used as gene markers to distinguish different Proteus species. Further web-based DNA-DNA hybridization estimated by genome of type strains confirmed the validity of the MLSA, and each of eleven clusters was congruent with the most abundant Proteus species. In addition, we used the established MLSA method to identify the randomly collected Proteus and found that P. mirabilis is the most abundant species. However, the second most abundant species is P. terrae but not P. vulgaris. Combined with the genetic, genomic and phenotypic characteristics, these findings indicate that three species, P. terrae, P. cibarius and Proteus genospecies 5, should be regarded as heterotypic synonyms, and the species should be renamed P. terrae, while Proteus genospecies 5 has not been named to date.
CONCLUSIONS
This study suggested that MLSA is a powerful method for the discrimination and classification of Proteus at the species level. The MLSA scheme provides a rapid and inexpensive means of identifying Proteus strains. The identification of Proteus species determined by the MLSA approach plays an important role in the clinical diagnosis and treatment of Proteus infection.
Topics: Bacterial Proteins; Bacterial Typing Techniques; Cross Infection; Genes, Essential; Humans; Multilocus Sequence Typing; Phylogeny; Proteus
PubMed: 32522175
DOI: 10.1186/s12866-020-01844-1 -
Romanian Journal of Morphology and... 2016A 46-year-old female patient presented with photosensitivity, symmetric arthritis, episodic plantar pain and strikingly redundant plantar skin folds, likely due to...
A 46-year-old female patient presented with photosensitivity, symmetric arthritis, episodic plantar pain and strikingly redundant plantar skin folds, likely due to lipoatrophy after recurrent episodes of plantar panniculitis. In this context, leukopenia with lymphopenia, thrombocytopenia and positive antinuclear antibodies were revelatory for systemic lupus erythematosus. However, a small cerebriform plantar collagenoma, along with discrete dysmorphic features with downslanting palpebral fissures and mild right ptosis, second and third syndactyly and a larger first right toe since childhood, and early-onset bilateral ovarian cystadenoma, suggested a minimal Proteus syndrome. Genetic confirmation could not be performed. As adipose tissue dysregulation may be a feature of Proteus syndrome, the possible mechanisms leading to localized lipoatrophy in this setting are discussed. This case enlights intriguing links between adipogenesis, inflammation and dysmorphology. From a practical point of view, finding and treating an over-imposed inflammation could help limit damage in a hamartomatous syndrome.
Topics: Female; Foot; Humans; Middle Aged; Proteus Syndrome; Skin Diseases
PubMed: 28002528
DOI: No ID Found -
BMC Microbiology Nov 2021Penicillin was the first and most famous fungal secondary metabolite used as broad spectrum antibiotic that revolutionarised pharmaceutical research and also saved...
PROBLEM BACKGROUND
Penicillin was the first and most famous fungal secondary metabolite used as broad spectrum antibiotic that revolutionarised pharmaceutical research and also saved millions of lives. The over optimistic belief in 1967 that sufficient antibiotics had been discovered to defeat infectious diseases was quickly crashed with the appearance of multidrug resistant (MDR) bacteria in 1990s. This has posed a serious threat to mankind. Although scientists are making efforts to synthesize and discover new antibiotics there are not enough new drugs in pharmaceutical pipeline to beat the pace at which MDR bacteria are emerging. In view of this there is an urgent and serious medical need for new bioactive compounds to be discovered to treat infections caused by MDR pathogens. The present study is aimed to investigate the antibacterial potential of Aspergillus flavus originated compounds that may act as drug leads to treat future infections.
METHODOLOGY
Among the 6 isolated fungal strains from the rhizosphere of Mentha piperetta, one was processed for isolation of secondary metabolites on the basis of preliminary antibacterial testing. Observation of morphological and microscopic features helped in identification of the fungal strain as Aspergillus flavus. Potato Dextrose Agar (PDA) medium was used for fungal growth while Czapec Yeast Broth (CYB) medium was used for production of fungal metabolites. Column chromatography technique was utilized for purification of compound from crude fungal extract and the mass of the compound was determined using Liquid Chromatography Mass Spectrometry (LCMS) method. Structure elucidation of the pure compound was performed using 500 Varian Nuclear Magnetic Resonance (NMR) machine. Docking was performed using Glide SP algorithm. Agar well diffusion method was used to determine the invitro antibacterial potential of the compound against two MDR bacterial strains i.e. Staphylococcus aureus and Proteus vulgaris. For this a total of 4 dose concentrations i.e. (100, 250, 500, 1000 μg mL) of the compound were prepared and applied to bacterial strains on Mueller Hinton agar using tetracycline as control.
RESULTS
The chemical name of the purified compound from A. flavus was determined as (2E)-3-[(3S, 4R)-8-hydroxy-3, 4-dimethyl-1-oxo-3, 4-dihydro-1H-2- benzopyran-7-yl] prop-2-enoic acid with the formula CHO and exact mass of 262.08. The in-Silico analysis showed that this compound has the potential to inhibit the binding pocket of S. aureus TyrRS (1JII) with docking score of - 8.67 Kcal mole. The results obtained from invitro experiments were encouraging as at 1000 μg mL the compound showed 58.8% inhibition against S. aureus and 28% inhibition against P. vulgaris.
CONCLUSIONS
The pure compound with formula CHO and exact mass of 262 exhibited antibacterial potential both insilico and invitro against both Gram negative and Gram positive bacteria. The compound was more active against S. aureus in comparison to P. vulgaris. From the obtained results it is concluded that this compound can be used as potent antibacterial candidate but further studies will be needed prior to its use as antibiotic.
Topics: Anti-Bacterial Agents; Aspergillus flavus; Drug Resistance, Bacterial; Mentha piperita; Microbial Sensitivity Tests; Proteus vulgaris; Secondary Metabolism; Soil Microbiology; Staphylococcus aureus
PubMed: 34798838
DOI: 10.1186/s12866-021-02371-3 -
Journal of Global Antimicrobial... Jun 2022The prevalence of tet(X) genes threatens the clinical use of last-line tigecycline. The tet(X6) gene has been reported in Proteus strains, but its genetic context is...
OBJECTIVES
The prevalence of tet(X) genes threatens the clinical use of last-line tigecycline. The tet(X6) gene has been reported in Proteus strains, but its genetic context is rarely reported. This study aimed to investigate the prevalence and genetic contexts of tet(X6) gene in Proteus spp.
METHODS
A tet(X6) variant-bearing P. terrae subsp. cibarius strain was subjected to susceptibility testing, determination of growth curves, scanning electron microscopy, transmission electron microscopy and whole-genome sequencing (WGS). The genomic contexts of the tet(X6)-positive strain were analysed by sequence comparison and annotation.
RESULTS
ZJ19PC, a P. terrae subsp. cibarius strain harbouring the tet(X6) variant, was isolated from 20 cecum samples collected in Zhejiang, China. The chromosome size of ZJ19PC was 3 952 084 bp; the GC content was 38.2%; and hugA, sul2, tet(H), floR, dfra1, aadA1, aac(3)-IV and aph(4)-la were found in addition to the tet(X6) variant. Proteus spp. could be classified into three groups based on the tet(X6) gene contexts. Strain ZJ19PC belongs to group 1 (sra-sul2-ISCR2-floR-ISCR2-floR-ISCR2- tet(X6) variant-tnpA-ISEc59-aph(4)-la-aac(3)-Iva-IS26), and this region of group 1 was inserted between modA and guaA. The common antimicrobial resistance (AMR) genes of the three types of AMR gene islands were sul2, floR, tet(X6) and aac(3). The tet(X6) gene contexts and SNP tree showed that ZJ19PC was homologous to HNCF44W and HNCF43W, which indicated that these strains may be clonally transmitted.
CONCLUSION
This study analysed the genetic contexts of the tet(X6) gene in Proteus spp. and highlighted the significance of monitoring tigecycline-resistant P. terrae subsp. cibarius.
Topics: Animals; Anti-Bacterial Agents; Cecum; Proteus; Tigecycline
PubMed: 35218939
DOI: 10.1016/j.jgar.2022.02.011 -
Tidsskrift For Den Norske Laegeforening... Mar 2019Purple urine bag syndrome (PUBS) can occur in cases of bacteriuria with species expressing enzymes capable of converting tryptophan metabolites to red and blue pigments...
BACKGROUND
Purple urine bag syndrome (PUBS) can occur in cases of bacteriuria with species expressing enzymes capable of converting tryptophan metabolites to red and blue pigments which are excreted in urine, leaving a characteristic purple colour. Risk factors include urinary catheterisation, constipation and chronic kidney disease. Treatment includes catheter replacement, and antibiotics in case of urinary tract infection.
CASE PRESENTATION
A man in his 70s with myelodysplastic syndrome, stage 5 chronic kidney disease and chronic indwelling urinary catheterisation due to benign prostatic hyperplasia was admitted for transfusion for symptomatic anaemia. On the second day of hospitalisation, his urine turned purple. There was no sign of transfusion reaction, haemoglobinuria, myoglobinuria or bilirubinuria. Urine cultures were positive for Proteus vulgaris and Enterococcus faecalis, two species associated with PUBS.
INTERPRETATION
The constellation was consistent with PUBS. His bacteriuria was considered colonisation not requiring antibiotic treatment. The catheter was replaced and the urine colour returned to normal.
Topics: Aged; Bacteriuria; Catheter-Related Infections; Enterococcus faecalis; Humans; Male; Proteus vulgaris; Urinary Catheters; Urinary Tract Infections; Urine
PubMed: 30917642
DOI: 10.4045/tidsskr.18.0677