-
Journal of Bacteriology Apr 2019The airway fluids of cystic fibrosis (CF) patients contain local pH gradients and are more acidic than those of healthy individuals. pH is a critical factor that is...
The airway fluids of cystic fibrosis (CF) patients contain local pH gradients and are more acidic than those of healthy individuals. pH is a critical factor that is often overlooked in studies seeking to recapitulate the infection microenvironment. We sought to determine the impact of pH on the physiology of a ubiqituous yet understudied microbe, Phylogenomics was first used to reconstruct evolutionary relationships between 74 strains of (59 from CF patients). Neither the core genome (2,158 genes) nor the accessory genome (11,978 genes) distinguish the CF and non-CF isolates; however, strains from similar isolation sources grouped into the same subclades. We grew two human and six CF isolates from different subclades at a range of pH values and observed impaired growth and altered antibiotic tolerances at pH 5. Transcriptomes revealed increased expression of both antibiotic resistance and DNA repair genes in acidic conditions. Although the gene expression profiles of in lab cultures and CF sputum were distinct, we found that the same genes associated with low pH were also expressed during infection, and the higher pH cultures were more similar to sputum metatranscriptomes. Our findings suggest that is not well adapted to acidity and may cope with low pH by expressing stress response genes and colonizing less acidic microenvironments. As a whole, our study underlines the impact of microenvironments on bacterial colonization and adaptation in CF infections. Understanding bacterial responses to physiological conditions is an important priority for combating opportunistic infections. The majority of CF patients succumb to inflammation and necrosis in the airways, arising from chronic infection due to ineffective mucociliary clearance. Steep pH gradients characterize the CF airways but are not often incorporated in standard microbiology culture conditions. is a prevalent CF opportunistic pathogen also found in many disparate environments, yet this bacterium's contribution to CF lung damage and its response to changing environmental factors remain largely understudied. Here, we show that pH impacts the physiology and antibiotic susceptibility of , with implications for the development of relevant models and assessment of antibiotic sensitivity.
Topics: Adaptation, Physiological; Cystic Fibrosis; Gene Expression Profiling; Gram-Negative Bacterial Infections; Humans; Hydrogen-Ion Concentration; Stenotrophomonas maltophilia
PubMed: 30642989
DOI: 10.1128/JB.00478-18 -
Molecules (Basel, Switzerland) Sep 2022Immobilization is a commonly used method in response to the need to increase the resistance of microorganisms to the toxic effects of xenobiotics. In this study, a plant...
Immobilization is a commonly used method in response to the need to increase the resistance of microorganisms to the toxic effects of xenobiotics. In this study, a plant sponge from was used as a carrier for the immobilization of the KB2 strain since such a carrier meets the criteria for high-quality carriers, i.e., low price and biodegradability. The optimal immobilization conditions were established as a temperature of 30 °C, pH 7.2, incubation time of 72 h, and an optical density of the culture of 1.4. The strain immobilized in such conditions was used for the biodegradation of naproxen, and an average rate of degradation of 3.8 µg/hour was obtained under cometabolic conditions with glucose. The obtained results indicate that a microbiological preparation based on immobilized cells on a luffa sponge can be used in bioremediation processes where it is necessary to remove the introduced carrier.
Topics: Biodegradation, Environmental; Glucose; Luffa; Naproxen; Stenotrophomonas maltophilia; Xenobiotics
PubMed: 36144528
DOI: 10.3390/molecules27185795 -
Scientific Reports Dec 2023Prophages, which enables bacterial hosts to acquire novel traits, and increase genetic variation and evolutionary innovation, are considered to be one of the greatest...
Prophages, which enables bacterial hosts to acquire novel traits, and increase genetic variation and evolutionary innovation, are considered to be one of the greatest drivers of bacterial diversity and evolution. Stenotrophomonas maltophilia is widely distributed and one of the most important multidrug resistant bacteria in hospitals. However, the distribution and genetic diversity of S. maltophilia prophages have not been elucidated. In this study, putative prophages were predicted in S. maltophilia genomes by using virus prediction tools, and the genetic diversity and phylogeny of S. maltophilia and the prophages they harbor were further analyzed. A total of 356 prophage regions were predicted from 88 S. maltophilia genomes. Among them, 144 were intact prophages, but 77.09% of the intact prophages did not match any known phage sequences in the public database. The number of prophage carried by S. maltophilia is related to its host habitat and is an important factor affecting the size of the host genome, but it is not related to the genetic diversity of the prophage. The prediction of auxiliary genes encoded by prophage showed that antibiotic resistance genes was not predicted for any of the prophages except for one questionable prophage, while 53 virulence genes and 169 carbohydrate active enzymes were predicted from 11.24 and 44.1% prophages, respectively. Most of the prophages (72.29%) mediated horizontal gene transfer of S. maltophilia genome, but only involved in 6.25% of the horizontal gene transfer events. In addition, CRISPR prediction indicated 97.75% S. maltophilia strains contained the CRISPR-Cas system containing 818 spacer sequences. However, these spacer sequences did not match any known S. maltophilia phages, and only a few S. maltophilia prophages. Comparative genomic analysis revealed a highly conserved and syntenic organization with genomic rearrangement between the prophages and the known related S. maltophilia phages. Our results indicate a high prevalence and genetic diversity of prophages in the genome of S. maltophilia, as well as the presence of a large number of uncharacterized phages. It provides an important complement to understanding the diversity and biological characteristics of phages, as well as the interactions and evolution between bacteria and phages.
Topics: Prophages; Phylogeny; Stenotrophomonas maltophilia; Genomics; Gene Transfer, Horizontal
PubMed: 38135742
DOI: 10.1038/s41598-023-50449-x -
International Journal of Molecular... Jul 2020Although strains are efficient biocontrol agents, their field applications have raised concerns due to their possible threat to human health. The non-pathogenic... (Comparative Study)
Comparative Study
Although strains are efficient biocontrol agents, their field applications have raised concerns due to their possible threat to human health. The non-pathogenic species, which is closely related to has been proposed as an alternative. However, knowledge regarding the genetics of is limited. Thus, the aim of the study was to define any genetic differences between the species and to characterise their ability to promote the growth of plant hosts as well as to enhance phytoremediation efficiency. We compared 37 strains that belong to both species using the tools of comparative genomics and identified 96 genetic features that are unique to (e.g., chitin-binding protein, mechanosensitive channels of small conductance and KGG repeat-containing stress-induced protein) and 59 that are unique to (e.g., glucosylglycerol-phosphate synthase, cold shock protein with the DUF1294 domain, and pteridine-dependent dioxygenase-like protein). The strains from both species have a high potential for biocontrol, which is mainly related to the production of keratinases (KerSMD and KerSMF), proteinases and chitinases. Plant growth promotion traits are attributed to the biosynthesis of siderophores, spermidine, osmoprotectants such as trehalose and glucosylglycerol, which is unique to . In eight out of 37 analysed strains, the genes that are required to degrade protocatechuate were present. While our results show genetic differences between the two species, they had a similar growth promotion potential. Considering the information above, constitutes a promising alternative for for use in agricultural biotechnology.
Topics: Biodegradation, Environmental; Biological Control Agents; DNA, Bacterial; Enzymes; Gene Ontology; Genes, Bacterial; Genome, Bacterial; Genomics; Host-Pathogen Interactions; Mechanotransduction, Cellular; Phylogeny; Plant Proteins; Quorum Sensing; Species Specificity; Stenotrophomonas; Stenotrophomonas maltophilia; Virulence; Xenobiotics
PubMed: 32664682
DOI: 10.3390/ijms21144922 -
Phytopathology Nov 2021is ubiquitous in diverse environmental habitats. It merits significant concern because of its increasing incidence of nosocomial and community-acquired infection in...
is ubiquitous in diverse environmental habitats. It merits significant concern because of its increasing incidence of nosocomial and community-acquired infection in immunocompromised patients and multiple drug resistance. It is rarely reported as a phytopathogen except in causing white stripe disease of rice in India and postharvest fruit rot of Lanzhou lily. For this study, and strains were simultaneously isolated from soft rot leaves of in Guangzhou, China, and were both demonstrated to be pathogenic to the host. Compared with the strains, strains propagated faster for greater growth in lysogeny broth medium and produced no cellulases or polygalacturonases, but did produce more proteases and fewer extracellular polysaccharides. Furthermore, strains swam and swarmed dramatically less on semisolid media, but formed a great many more biofilms. Both and strains isolated from clivia caused rot symptoms on other monocot hosts, but not on dicots. Similar to previously reported strains isolated from other sources, the strain JZL8 survived under many antibiotic stresses. The complete genome sequence of strain JZL8 consists of a chromosome of 4,635,432 bp without a plasmid. Pan-genome analysis of JZL8 and 180 other strains identified 50 genes that are unique to JZL8, seven of which implicate JZL8 as the potential pathogen contributor in plants. JZL8 also contains three copies of Type I Secretion System machinery; this is likely responsible for its greater production of proteases. Findings from this study extend our knowledge on the host range of and provide insight into the phenotypic and genetic features underlying the plant pathogenicity of JZL8.
Topics: Genomics; Humans; Oryza; Plant Diseases; Stenotrophomonas maltophilia; Virulence
PubMed: 33759550
DOI: 10.1094/PHYTO-11-20-0501-R -
Letters in Applied Microbiology Mar 2021Stenotrophomonas maltophilia isolates are responsible for various hospital-acquired infections and are particularly increasing in the immunocompromised patients. The aim...
Stenotrophomonas maltophilia isolates are responsible for various hospital-acquired infections and are particularly increasing in the immunocompromised patients. The aim of this study was to determine the clonal relatedness between S. maltophilia isolates originating from the clinic and environment. A total of 150 S. maltophilia isolates from patients and 1108 environmental samples obtained in three hospitals from Tehran. Following molecular identification targeting 23S rRNA gene, the clonal relatedness of the environmental and clinical isolates was determined using pulsed field gel electrophoresis (PFGE). Of the 150 clinical and 18 environmental isolates identified using phenotypic tests, the speciation of 120 and 15 was confirmed by targeting the 23S rRNA gene. The 24 common pulsotypes (PTs) and 32 single PTs were identified by PFGE. Only a small cluster was shared among the clinic and environment within a hospital; therefore, the intra-hospital dissemination of certain isolates of S. maltophilia among the clinic and environment was demonstrated.
Topics: Cross Infection; Electrophoresis, Gel, Pulsed-Field; Gram-Negative Bacterial Infections; Hospitals; Humans; Immunocompromised Host; Iran; Microbial Sensitivity Tests; RNA, Ribosomal, 23S; Stenotrophomonas maltophilia
PubMed: 33064916
DOI: 10.1111/lam.13416 -
Microbiology Spectrum Jan 2018Bacteria of the genus are found throughout the environment, in close association with soil, sewage, and plants. , the first member of this genus, is the predominant...
Bacteria of the genus are found throughout the environment, in close association with soil, sewage, and plants. , the first member of this genus, is the predominant species, observed in soil, water, plants, animals, and humans. It is also an opportunistic pathogen associated with the increased number of infections in both humans and animals in recent years. In this article, we summarize all species (mainly ) isolated from animals and food products of animal origin and further distinguish all isolates based on antimicrobial susceptibility and resistance phenotypes. The various mechanisms of both intrinsic and acquired antimicrobial resistance, which were mainly identified in isolates of nosocomial infections, have been classified as follows: multidrug efflux pumps; resistance to β-lactams, aminoglycosides, quinolones, trimethoprim-sulfamethoxazole, and phenicols; and alteration of lipopolysaccharide and two-component regulatory systems. The dissemination, coselection, and persistence of resistance determinants among isolates have also been elaborated.
Topics: Acetyltransferases; Animals; Anti-Bacterial Agents; Bacterial Proteins; Cross Infection; DNA Topoisomerases; Drug Resistance, Multiple, Bacterial; Food Microbiology; Gram-Negative Bacterial Infections; Membrane Transport Proteins; Microbial Sensitivity Tests; Stenotrophomonas maltophilia; beta-Lactam Resistance; beta-Lactamases
PubMed: 29350131
DOI: 10.1128/microbiolspec.ARBA-0005-2017 -
The Journal of Hospital Infection Jan 2020Levofloxacin has been considered as an alternative treatment for Stenotrophomonas maltophilia infection. However, levofloxacin-resistant S. maltophilia (LRSM) are...
BACKGROUND
Levofloxacin has been considered as an alternative treatment for Stenotrophomonas maltophilia infection. However, levofloxacin-resistant S. maltophilia (LRSM) are emerging worldwide.
AIM
To investigate LRSM risk factors in hospitalized patients and to determine antibiotic susceptibility patterns of LRSM isolates.
METHODS
In a retrospective matched case-control-control study, LRSM patients (the case group) were compared with two control groups: levofloxacin-susceptible S. maltophilia (LSSM) patients (control group A) and non-S. maltophilia-infected patients (control group B). Conditional logistic regression was used to analyse risk factors for LRSM occurrence. Tigecycline, ceftazidime, colistin, and trimethoprim/sulfamethoxazole (TMP/SMX) susceptibilities in collected LRSM clinical isolates were determined.
FINDINGS
A total of 105 LRSM, 105 LSSM, and 105 non-S. maltophilia-infected patients were analysed. The first multivariate analysis (cases vs group A) revealed that previous fluoroquinolones use was significantly associated with LRSM occurrence, and the second multivariate analysis (cases vs group B) revealed that previous fluoroquinolone use, previous intensive care unit stay, and the number of previous exposures to different classes of antibiotics were significantly associated with LRSM occurrence. Of all the LRSM isolates tested for antibiotic susceptibility, ceftazidime, TMP/SMX, tigecycline, and colistin resistance rates were 42.0, 99.0, 78.0, and 40.0%, respectively.
CONCLUSION
LRSM antibiotic susceptibility patterns revealed multiple-drug resistance, which further limits treatment options for clinicians. To reduce LRSM occurrence, proper use of antibiotics, especially fluoroquinolones, is mandatory.
Topics: Adult; Aged; Aged, 80 and over; Anti-Bacterial Agents; Case-Control Studies; Ceftazidime; Colistin; Drug Resistance, Multiple, Bacterial; Female; Fluoroquinolones; Gram-Negative Bacterial Infections; Hospitalization; Humans; Intensive Care Units; Levofloxacin; Male; Microbial Sensitivity Tests; Middle Aged; Retrospective Studies; Risk Factors; Stenotrophomonas maltophilia; Taiwan; Tigecycline; Trimethoprim, Sulfamethoxazole Drug Combination
PubMed: 31505224
DOI: 10.1016/j.jhin.2019.09.001 -
Genes Apr 2021In patients with cystic fibrosis (CF), the lung is a remarkable ecological niche in which the microbiome is subjected to important selective pressures. An inexorable... (Review)
Review
In patients with cystic fibrosis (CF), the lung is a remarkable ecological niche in which the microbiome is subjected to important selective pressures. An inexorable colonization by bacteria of both endogenous and environmental origin is observed in most patients, leading to a vicious cycle of infection-inflammation. In this context, long-term colonization together with competitive interactions among bacteria can lead to over-inflammation. While and , the two pathogens most frequently identified in CF, have been largely studied for adaptation to the CF lung, in the last few years, there has been a growing interest in emerging pathogens of environmental origin, namely and . The aim of this review is to gather all the current knowledge on the major pathophysiological traits, their supporting mechanisms, regulation and evolutionary modifications involved in colonization, virulence, and competitive interactions with other members of the lung microbiota for these emerging pathogens, with all these mechanisms being major drivers of persistence in the CF lung. Currently available research on complex and shows that these emerging pathogens share important pathophysiological features with well-known CF pathogens, making them important members of the complex bacterial community living in the CF lung.
Topics: Achromobacter denitrificans; Adaptation, Physiological; Cystic Fibrosis; Gram-Negative Bacterial Infections; Humans; Lung; Mutation Rate; Stenotrophomonas maltophilia
PubMed: 33919046
DOI: 10.3390/genes12050610 -
Infectious Diseases (London, England) Mar 2019Stenotrophomonas maltophilia is an increasingly prevalent opportunistic pathogen responsible for a wide range of nosocomial infections in intensive care unit patients,... (Review)
Review
Stenotrophomonas maltophilia is an increasingly prevalent opportunistic pathogen responsible for a wide range of nosocomial infections in intensive care unit patients, life-threatening diseases in immunocompromised haematology-oncology patients and chronic pulmonary infections in individuals with cystic fibrosis. Therapy of these infections is problematic due to the remarkable intrinsic antimicrobial resistance of the species and to acquired resistance to multiple antimicrobial agents. As this organism is a low-grade pathogen, the pathogenesis of S. maltophilia infections involves numerous virulence factors as well as the ability of bacterial cells to form biofilms on abiotic surfaces and host tissues. The present review summarizes the literature data regarding extracellular and cell-associated virulence factors of S. maltophilia (some of which have still not been studied in detail) and considers the basic characteristics of biofilm formation. Many virulence features such as extracellular enzymes, bacterial motility and biofilm formation are finely controlled by quorum sensing (QS) that enable the bacteria to express these virulence factors in a coordinated, cell-density-dependent manner and overwhelm the host defence mechanisms. Manipulating the QS regulatory system is a promising approach for development of new strategies for control of S. maltophilia infections.
Topics: Biofilms; Gram-Negative Bacterial Infections; Humans; Stenotrophomonas maltophilia; Virulence; Virulence Factors
PubMed: 30422737
DOI: 10.1080/23744235.2018.1531145