-
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 -
The Journal of Infection Mar 2020Stenotrophomonas maltophilia (SM) is increasingly identified in intensive care unit (ICU). This study aim to identify risk factors for SM ventilator-associated pneumonia...
BACKGROUND
Stenotrophomonas maltophilia (SM) is increasingly identified in intensive care unit (ICU). This study aim to identify risk factors for SM ventilator-associated pneumonia (VAP) and whether it affects ICU mortality METHODS: Two nested matched case-control studies were performed based in OUTCOMEREA database. The first episodes of SM-VAP patients were matched with two different control groups: VAP due to other micro-organisms (VAP-other) and Pseudomonas aeruginosa VAP (Pyo-VAP). Matching criteria were the hospital, the SAPS II, and the previous duration of mechanical ventilation (MV).
RESULTS
Of the 102 SM-VAP patients (6.2% of all VAP patients), 92 were matched with 375 controls for the SM-VAP/other-VAP matching and 84 with 237 controls for the SM-VAP/Pyo-VAP matching. SM-VAP risk factors were an exposition to ureido/carboxypenicillin or carbapenem during the week before VAP, and respiratory and coagulation components of SOFA score upper to 2 before VAP. SM-VAP received early adequate therapy in 70 cases (68.6%). Risk factors for Day-30 were age (OR = 1.03; p < 0.01) and Chronic heart failure (OR = 3.15; p < 0.01). Adequate treatment, either monotherapy or combination of antimicrobials, did not modify mortality. There was no difference in 30-day mortality, but 60-day mortality was higher in patients with SM-VAP compared to Other-VAP (P = 0.056).
CONCLUSIONS
In a large series, independent risk factors for the SM-VAP were ureido/carboxypenicillin or carbapenem exposure the week before VAP, and respiratory and coagulation components of the SOFA score > 2 before VAP. Mortality risk factors of SM-VAP were age and chronic heart failure. Adequate treatment did not improve SM-VAP prognosis.
Topics: Carbapenems; Humans; Intensive Care Units; Pneumonia, Ventilator-Associated; Risk Factors; Stenotrophomonas maltophilia
PubMed: 31682878
DOI: 10.1016/j.jinf.2019.10.021 -
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 -
Microorganisms Aug 2021has been reported in various ocular infections, including keratitis, conjunctivitis, preseptal cellulitis, and endophthalmitis, all of which may lead to vision loss....
has been reported in various ocular infections, including keratitis, conjunctivitis, preseptal cellulitis, and endophthalmitis, all of which may lead to vision loss. However, the strain is resistant to a wide variety of antibiotics, including penicillins, third-generation cephalosporins, aminoglycosides, and imipenem. In this study, we retrospectively reviewed the clinical characteristics, antibiotic susceptibility, antimicrobial minimum inhibitory concentrations (MICs), and visual outcomes for endophthalmitis. The data of 9 patients with positive cultures in a tertiary referral center from 2010 to 2019 were reviewed. Cataract surgery ( = 8, 89%) was the most common etiology, followed by intravitreal injection ( = 1, 11%). 's susceptibility to levofloxacin and moxifloxacin was observed in 6 cases (67%). Seven isolates were resistant to sulfamethoxazole-trimethoprim (78%). The MIC for was 256, 256, 256, 8, 12, 12, 12, and 8 μg/mL for amikacin, cefuroxime, ceftazidime, tigecycline, sulfamethoxazole-trimethoprim, levofloxacin, galtifloxacin, and moxifloxacin, respectively. Final visual acuity was 20/200 or better in 5 patients (56%). Fluoroquinolones and tigecycline exhibited low antibiotic MIC. Therefore, the results suggest that fluoroquinolones can be used as first-line antibiotics for endophthalmitis.
PubMed: 34576735
DOI: 10.3390/microorganisms9091840 -
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 -
Clinics in Chest Medicine Dec 2022Patients with cystic fibrosis (CF) often develop respiratory tract infections with pathogenic multidrug-resistant organisms (MDROs) such as methicillin-resistant... (Review)
Review
Patients with cystic fibrosis (CF) often develop respiratory tract infections with pathogenic multidrug-resistant organisms (MDROs) such as methicillin-resistant Staphylococcus aureus, and a variety of gram-negative organisms that include Pseudomonas aeruginosa, Burkholderia sp., Stenotrophomonas maltophilia, Achromobacter xylosoxidans, and nontuberculous mycobacteria (NTM). Despite the introduction of new therapies to address underlying cystic fibrosis transmembrane conductance regulator (CFTR) dysfunction, MDRO infections remain a problem and novel antimicrobial interventions are still needed. Therapeutic approaches include improving the efficacy of existing drugs by adjusting the dose based on differences in CF patient pharmacokinetics/pharmacodynamics, the development of inhaled formulations to reduce systemic adverse events, and the use of newer beta-lactam/beta-lactamase combinations. Alternative innovative therapeutic approaches include the use of gallium and bacteriophages to treat MDRO pulmonary infections including those with extreme antibiotic resistance. However, additional clinical trials are required to determine the optimal dosing and efficacy of these different strategies and to identify patients with CF most likely to benefit from these new treatment options.
Topics: Humans; Cystic Fibrosis; Methicillin-Resistant Staphylococcus aureus; Stenotrophomonas maltophilia; Pseudomonas aeruginosa; Respiratory Tract Infections; Anti-Bacterial Agents; Pseudomonas Infections
PubMed: 36344073
DOI: 10.1016/j.ccm.2022.06.008 -
Frontiers in Cellular and Infection... 2024The hemin acquisition system is composed of an outer membrane TonB-dependent transporter that internalizes hemin into the periplasm, periplasmic hemin-binding proteins...
INTRODUCTION
The hemin acquisition system is composed of an outer membrane TonB-dependent transporter that internalizes hemin into the periplasm, periplasmic hemin-binding proteins to shuttle hemin, an inner membrane transporter that transports hemin into the cytoplasm, and cytoplasmic heme oxygenase to release iron. Fur and HemP are two known regulators involved in the regulation of hemin acquisition. The hemin acquisition system of is poorly understood, with the exception of HemA as a TonB-dependent transporter for hemin uptake.
METHODS
Putative candidates responsible for hemin acquisition were selected via a homolog search and a whole-genome survey of . Operon verification was performed by reverse transcription-polymerase chain reaction. The involvement of candidate genes in hemin acquisition was assessed using an in-frame deletion mutant construct and iron utilization assays. The transcript levels of candidate genes were determined using quantitative polymerase chain reaction.
RESULTS
and operons were selected as candidates for hemin acquisition. Compared with the parental strain, and mutants displayed a defect in their ability to use hemin as the sole iron source for growth. However, hemin utilization by the and mutants was comparable to that of the parental strain. expression was repressed by Fur in iron-replete conditions and derepressed in iron-depleted conditions. HemP negatively regulated expression. Like , was repressed by Fur in iron-replete conditions; however, was moderately derepressed in response to iron-depleted stress and fully derepressed when hemin was present. Unlike and , the operon was constitutively expressed, regardless of the iron level or the presence of hemin, and Fur and HemP had no influence on its expression.
CONCLUSION
HemA, HemU, and TonB1 contribute to hemin acquisition in . Fur represses the expression of and in iron-replete conditions. expression is regulated by low iron levels, and HemP acts as a negative regulator of this regulatory circuit. expression is regulated by low iron and hemin levels in a -dependent manner.
Topics: Hemin; Stenotrophomonas maltophilia; Bacterial Proteins; Membrane Proteins; Iron
PubMed: 38596648
DOI: 10.3389/fcimb.2024.1380976 -
Antibiotics (Basel, Switzerland) Oct 2021is an urgent global threat due to its increasing incidence and intrinsic antibiotic resistance. Antibiotic development has focused on carbapenem-resistant... (Review)
Review
is an urgent global threat due to its increasing incidence and intrinsic antibiotic resistance. Antibiotic development has focused on carbapenem-resistant Enterobacteriaceae, Pseudomonas, and Acinetobacter, with approved antibiotics in recent years having limited activity for Stenotrophomonas. Accordingly, novel treatment strategies for Stenotrophomonas are desperately needed. We conducted a systemic literature review and offer recommendations based on current evidence for a treatment strategy of Stenotrophomonas infection.
PubMed: 34680807
DOI: 10.3390/antibiotics10101226