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Xanthomonas maltophilia [keywords]
- Evaluation of a New Monochloramine Generation System for Controlling Legionella in Building Hot Water Systems. [JOURNAL ARTICLE]
- Infect Control Hosp Epidemiol 2014 Nov; 35(11):1356-1363.
Objective. To evaluate the efficacy of a new monochloramine generation system for control of Legionella in a hospital hot water distribution system. Setting. A 495-bed tertiary care hospital in Pittsburgh, Pennsylvania. The hospital has 12 floors covering approximately 78,000 m(2). Methods. The hospital hot water system was monitored for a total of 29 months, including a 5-month baseline sampling period prior to installation of the monochloramine system and 24 months of surveillance after system installation (postdisinfection period). Water samples were collected for microbiological analysis (Legionella species, Pseudomonas aeruginosa, Stenotrophomonas maltophilia, Acinetobacter species, nitrifying bacteria, heterotrophic plate count [HPC] bacteria, and nontuberculous mycobacteria). Chemical parameters monitored during the investigation included monochloramine, chlorine (free and total), nitrate, nitrite, total ammonia, copper, silver, lead, and pH. Results. A significant reduction in Legionella distal site positivity was observed between the pre- and postdisinfection periods, with positivity decreasing from an average of 53% (baseline) to an average of 9% after monochloramine application ([Formula: see text]). Although geometric mean HPC concentrations decreased by approximately 2 log colony-forming units per milliliter during monochloramine treatment, we did not observe significant changes in other microbial populations. Conclusions. This is the first evaluation in the United States of a commercially available monochloramine system installed on a hospital hot water system for Legionella disinfection, and it demonstrated a significant reduction in Legionella colonization. Significant increases in microbial populations or other negative effects previously associated with monochloramine use in large municipal cold water systems were not observed.
- Novel Cyclic di-GMP Effectors of the YajQ Protein Family Control Bacterial Virulence. [JOURNAL ARTICLE]
- PLoS Pathog 2014 Oct; 10(10):e1004429.
Bis-(3',5') cyclic di-guanylate (cyclic di-GMP) is a key bacterial second messenger that is implicated in the regulation of many critical processes that include motility, biofilm formation and virulence. Cyclic di-GMP influences diverse functions through interaction with a range of effectors. Our knowledge of these effectors and their different regulatory actions is far from complete, however. Here we have used an affinity pull-down assay using cyclic di-GMP-coupled magnetic beads to identify cyclic di-GMP binding proteins in the plant pathogen Xanthomonas campestris pv. campestris (Xcc). This analysis identified XC_3703, a protein of the YajQ family, as a potential cyclic di-GMP receptor. Isothermal titration calorimetry showed that the purified XC_3703 protein bound cyclic di-GMP with a high affinity (Kd∼2 µM). Mutation of XC_3703 led to reduced virulence of Xcc to plants and alteration in biofilm formation. Yeast two-hybrid and far-western analyses showed that XC_3703 was able to interact with XC_2801, a transcription factor of the LysR family. Mutation of XC_2801 and XC_3703 had partially overlapping effects on the transcriptome of Xcc, and both affected virulence. Electromobility shift assays showed that XC_3703 positively affected the binding of XC_2801 to the promoters of target virulence genes, an effect that was reversed by cyclic di-GMP. Genetic and functional analysis of YajQ family members from the human pathogens Pseudomonas aeruginosa and Stenotrophomonas maltophilia showed that they also specifically bound cyclic di-GMP and contributed to virulence in model systems. The findings thus identify a new class of cyclic di-GMP effector that regulates bacterial virulence.
- Stenotrophomonas maltophilia Pseudo-outbreak at a University Hospital Bronchoscopy Unit in Turkey. [JOURNAL ARTICLE]
- West Indian Med J 2014 Apr 8; 63(1):64-66.
Stenotrophomonas maltophilia is an opportunistic pathogen found predominantly in the environment and hospital setting. Invasive procedures and treatment methods, instruments used for diagnosis and irrational antibiotic use play major roles in the spread of this pathogen. The study aimed to evaluate consecutive S maltophilia isolation from bronchoalveolar lavage samples during bronchoscopy procedure during a week.Four patients consecutively had S maltophilia isolated during bronchoscopy between September 8 and 15, 2012. The identification of the isolates and their antibiotic susceptibility were studied by automated Vitek version 2.0 (Biomerieux, France) system. The clonal relationship between the isolates was studied by Enterobacterial repetitive intergenic consensus (ERIC) polymerase chain reaction (PCR).Four consecutive S maltophilia isolates had identical band patterns and showed clonal relatedness.Bronchoscopy is a common invasive procedure that is utilized in chest diseases departments and intensive care units (ICUs). Contamination may take place due to inappropriate use and spread of infectious pathogens. In the current study, we detected consecutive S maltophilia strains with identical band patterns isolated within a week. After appropriate disinfection and cleaning procedures, no further isolation was detected.
- Highly efficient transformation of Stenotrophomonas maltophilia S21, an environmental isolate from soil, by electroporation. [JOURNAL ARTICLE]
- J Microbiol Methods 2014 Oct 6.
Stenotrophomonas maltophilia is an emerging opportunistic pathogen, which also exhibits potential of wide applications in industry, environment and agriculture. An efficient transformation method for S. maltophilia would be convenient to its genetic studies. In this report, we focused on developing an efficient transformation protocol for S. maltophilia. Gene transfer by three different methods (chemical transformation, conjugation and electroporation) indicated that electroporation was the most efficient method to transform S. maltophilia S21. Then, the entire electroporation process from competent-cell preparation to post-pulse incubation was optimized to get higher efficiencies. Utilizing competent cells prepared at optical density (600 nm) of 1.0, the maximal transformation efficiency of S. maltophilia S21 reached 1.53×10(8) transformants/μg of pBBR1MCS DNA at a field strength of 18 kV/cm, a time constant of 4.8 ms (200 Ω), a DNA amount of 100 ng and a cell concentration of 2.4×10(8) CFU/ml after 3 h incubation. Moreover, we successfully transformed the other four isolates of S. maltophilia using this protocol. To date, this is the first report about electroporation of S. maltophilia and it will facilitate the further study of this species.
- Stenotrophomonas maltophilia Infection Among Young Children in a Cardiac Intensive Care Unit: A Single Institution Experience. [JOURNAL ARTICLE]
- Pediatr Cardiol 2014 Oct 8.
Stenotrophomonas maltophilia can present as bacteremia, respiratory tract infection, urinary tract infection, soft tissue and wound infections, bone and joint infections, meningitis, and endocarditis especially in immunosuppressed patients and those with underlying medical conditions. The incidence and impact of S. maltophilia in young children with heart disease are poorly defined. A single center retrospective observational study was conducted in infants <180 days of age with positive S. maltophilia cultures over a period of 5 years. The overall incidence for S. maltophilia infection was 0.8 % (n = 32/3656). Among 32 identified infants, there were 47 episodes of S. maltophilia infection 66 % of infants had prior exposure to broad spectrum antibiotics. 97 % of positive isolates were susceptible to trimethoprim/sulfamethoxazole and 91 % to levofloxacin as well as ticarcillin/clavulanate. Ventilator-free days and absolute lymphocyte count prior to acquiring infection were significantly lower in non-survivors than in survivors. 100 % of survivors had clearance of positive cultures compared to 50 % in non-survivors (p < 0.05). The crude all-cause mortality rate was 37.5 %. All non-survivors had increased length of ICU stay and duration of mechanical ventilation and had delayed clearance of infection and required longer duration of treatment.
- The Impact of spgM, rpfF, rmlA Gene Distribution on Biofilm Formation in Stenotrophomonas maltophilia. [Journal Article]
- PLoS One 2014; 9(10):e108409.
Stenotrophomonas maltophilia is emerging as one of the most frequently found bacteria in chronic pulmonary infection. Biofilm is increasingly recognized as a contributing factor to disease pathogenesis. In the present study, a total of 37 isolates of S. maltophilia obtained from chronic pulmonary infection patients were evaluated to the relationship between biofilm production and the relative genes expression.The clonal relatedness of isolates was determined by pulse-field gel electrophoresis. Biofilm formation assays were performed by crystal violet assay, and confirmed by Electron microscopy analysis and CLSM analysis. PCR was employed to learn gene distribution and expression.Twenty-four pulsotypes were designated for 37 S. maltophilia isolates, and these 24 pulsotypes exhibited various levels of biofilm production, 8 strong biofilm-producing S. maltophilia strains with OD492 value above 0.6, 14 middle biofilm-producing strains with OD492 average value of 0.4 and 2 weak biofilm-producing strains with OD492 average value of 0.19. CLSM analysis showed that the isolates from the early stage of chronic infection enable to form more highly structured and multilayered biofim than those in the late stage. The prevalence of spgM, rmlA, and rpfF genes was 83.3%, 87.5%, and 50.0% in 24 S. maltophilia strains, respectively, and the presence of rmlA, spgM or rpfF had a close relationship with biofilm formation but did not significantly affect the mean amount of biofilm. Significant mutations of spgM and rmlA were found in both strong and weak biofilm-producing strains.Mutations in spgM and rmlA may be relevant to biofilm formation in the clinical isolates of S. maltophilia.
- Complementary treatment of contact lens-induced corneal ulcer using honey: A case report. [JOURNAL ARTICLE]
- Cont Lens Anterior Eye 2014 Sep 29.
The aim of this study was to report the complementary use of honey for treatment of a contact lens-induced corneal ulcer. A 23-year-old contact lens user presented with a corneal ulcer in her left eye. She had visual acuity reduced to hand movement. There was a history of wearing contact lenses while swimming in a lake seven days before presentation. The cultures from corneal scrapings and contact lenses were positive for Klebsiella oxytoca, Pseudomonas aeruginosa, Stenotrophomonas maltophilia and Pseudomonas spp. The treatment with topical levofloxacin and 25% (w/v) γ-irradiated honeydew honey solution was effective and the patient achieved final best corrected visual acuity of affected eye. In addition to positive clinical outcome, honeydew honey was shown to be highly effective in vitro against ocular isolates, in particular S. maltophilia. The minimal inhibitory concentrations for honeydew honey ranged from 5% to 10%. These results demonstrate that honey is a promising antibacterial agent in management of corneal ulcers. Moreover, honey exhibits anti-biofilm and anti-inflammatory properties, and thus becomes an interesting ophthalmologic agent.
- Delineation of Stenotrophomonas maltophilia isolates from cystic fibrosis patients by fatty acid methyl ester profiles and MALDI-TOF mass spectra using hierarchical cluster analysis and principal component analysis. [JOURNAL ARTICLE]
- J Med Microbiol 2014 Sep 29.
Stenotrophomonas maltophilia is an opportunist multidrug resistant pathogen that causes a wide range of nosocomial infections. Various cystic fibrosis (CF) centres have reported an increasing prevalence of S. maltophilia colonisation/infection among patients with this disease. The purpose of this study was to assess specific fingerprints of S. maltophilia isolates from CF patients (n=71) by investigating the fatty acid methyl esters (FAME) through gas chromatography (GC) and high abundant proteins by Matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS), and finally, to compare them to isolates obtained from intensive care unit (ICU) patients (n=20) and the environment (n=11). Principal component analysis of GC-FAME patterns did not reveal a clustering corresponding to distinct CF, ICU or environmental types. Based on the peak area index (PAI), it was observed that S. maltophilia isolates from CF patients produced significantly higher amount of fatty acids in comparison to ICU patients and the environmental isolates. Hierarchical cluster analysis (HCA) based on the MALDI-TOF MS peak profiles of S. maltophilia revealed the presence of five large clusters, suggesting a high phenotypic diversity. Although HCA of MALDI-TOF mass spectra did not result in distinct clusters predominantly composed of CF isolates, principal component analysis (PCA) revealed the presence of a distinct cluster composed of S. maltophilia isolated from CF-patients. Our data suggest that S. maltophilia colonising CF patients tend to modify not only their fatty acid patterns, but also their protein patterns as a response to adaptation in the CF-lung unfavourable environment.
- Combination of photoreactor and packed bed bioreactor for the removal of ethyl violet from wastewater. [JOURNAL ARTICLE]
- Chemosphere 2014 Sep 23.:494-501.
An efficient treatment system that combines a photoreactor and packed bed bioreactor (PBR) was developed and evaluated for treating ethyl violet (EV)-containing wastewater. Initial experiments demonstrated that the optimal operating parameters for the photoreactor in treating EV-containing wastewater were 2h reaction time, pH of 7, and 2min liquid retention time. Under these conditions, the photocatalytic reaction achieved a 61% EV removal efficiency and resulted in a significant BOD/COD increase in the solution. The results displayed by the coupled photobiological system achieved a removal efficiency of 85% and EC50 of the solution increased by 19 times in a semi-continuous mode when the EV concentration was <150mgL(-)(1). The effect of shock loading on the EV removal was temporary but coexisting substrate (glucose and crystal violet) at specific levels would affect the EV removal efficiency of the PBR. Phylogenetic analysis in the PBR indicated that the major bacteria species were Bdellovibrio bacteriovorus, Ralstonia pickettii, Stenotrophomonas maltophilia, and Comamonas sp. Furthermore, the possible degrading mechanisms of this coupled system were demethylation, deethylation, aromatic ring opening, nitrification, and carbon oxidation. The intermediates were characterized using gas chromatography-mass spectrometry analysis. These results indicated that the coupled photobiological system provides an effective method of EV removal.
- Complete Genome Sequence of Stenotrophomonas maltophilia Type Strain 810-2 (ATCC 13637). [Journal Article]
- Genome Announc 2014; 2(5)
An emerging nosocomial pathogen, Stenotrophomonas maltophila has a high mortality rate in those it infects. Here, we present the complete genome sequence of Stenotrophomonas maltophilia 810-2 (ATCC 13637), the type strain of the species. The 5-Mb (66.1% G+C content) genome has been deposited in NCBI under accession number CP008838.