scholarly journals The Toxin-Antitoxin Systems of the Opportunistic Pathogen Stenotrophomonas maltophilia of Environmental and Clinical Origin

Toxins ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 635
Author(s):  
Laurita Klimkaitė ◽  
Julija Armalytė ◽  
Jūratė Skerniškytė ◽  
Edita Sužiedėlienė
Keyword(s):  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Opportunistic Pathogen ◽  
Bioinformatic Analysis ◽  
Multidrug Resistant ◽  
Bacterial Toxin ◽  
Clinical Settings ◽  
Environmental Bacterium ◽  
Tract Infections

Stenotrophomonas maltophilia is a ubiquitous environmental bacterium that has recently emerged as a multidrug-resistant opportunistic pathogen causing bloodstream, respiratory, and urinary tract infections. The connection between the commensal environmental S. maltophilia and the opportunistic pathogen strains is still under investigation. Bacterial toxin–antitoxin (TA) systems have been previously associated with pathogenic traits, such as biofilm formation and resistance to antibiotics, which are important in clinical settings. The same species of the bacterium can possess various sets of TAs, possibly influencing their overall stress response. While the TA systems of other important opportunistic pathogens have been researched, nothing is known about the TA systems of S. maltophilia. Here, we report the identification and characterization of S. maltophilia type II TA systems and their prevalence in the isolates of clinical and environmental origins. We found 49 putative TA systems by bioinformatic analysis in S. maltophilia genomes. Despite their even spread in sequenced S. maltophilia genomes, we observed that relBE, hicAB, and previously undescribed COG3832-ArsR operons were present solely in clinical S. maltophilia isolates collected in Lithuania, while hipBA was more frequent in the environmental ones. The kill-rescue experiments in Escherichia coli proved higBA, hicAB, and relBE systems to be functional TA modules. Together with different TA profiles, the clinical S. maltophilia isolates exhibited stronger biofilm formation, increased antibiotic, and serum resistance compared to environmental isolates. Such tendencies suggest that certain TA systems could be used as indicators of virulence traits.

Global analyses imply that Stenotrophomonas maltophilia biofilms are phenotypically highly diverse despite a common transcriptome profile

2020 ◽  
Author(s):  
Ifey Alio ◽  
Mirja Gudzuhn ◽  
Marie Schölmerich ◽  
Pablo Pérez García ◽  
Christel Vollstedt ◽  
...  
Keyword(s):  
Biofilm Formation ◽  
Stenotrophomonas Maltophilia ◽  
Phenotypic Variability ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Clinical Settings ◽  
Data Set ◽  
Specific Level ◽  
Key Factor ◽  
Fermentative Growth

<p><strong>Stenotrophomonas maltophilia</strong><strong> is one of the most frequently isolated multidrug resistant opportunistic pathogens. It contributes to disease progression in cystic fibrosis patients and is found in wounds, other infected tissues and on catheter surfaces. Only little is known on key processes linked to biofilm formation of S. maltophilia on a broader basis. Thus the aim of this study was the identification of key processes involved in biofilm formation of S. maltophilia on a global level. Therefore, we analyzed biofilm profiles of 300 globally collected clinical and environmental isolates of the main and recently identified lineages Sgn3, Sgn4 and Sm2 - Sm18 (Groeschel et al., 2020). These data together with the 3D structural analysis of a subset of clinical 40 clinical isolates revealed an unexpectedly high phenotypic variability on a strain specific level. Further transcriptome analysis of seven clinical isolates using biofilm grown cells identified a set of 106 shared and coexpressed genes and roughly 30-35 strain-specific genes. Based on these findings S. maltophilia employs a mostly fermentative growth modus under the biofilm conditions and uptake of iron, phosphorous and other metals appears to be of high relevance. Surprisingly, the transcriptome profiles of biofilm versus planktonic cells revealed that only 8.6% of all genes were differentially regulated when both conditions were compared.  This implies that only relatively few genes contribute to the change from planktonic to biofilm life style. Thereby iron uptake appears to be a key factor involved in this metabolic shift. The transcriptome data generated in this study together with the phenotypic and metabolic analysis represent so far the largest data set on S. maltophilia biofilm versus planktonic grown cells. This study now lays the foundation for the identification of new strategies in fighting S. maltophilia infections in clinical settings.</strong></p> <p>Ref:  Gröschel et al., 2020 ,The phylogenetic landscape and nosocomial spread of the multidrug-resistant opportunist Stenotrophomonas maltophilia. Nature Commun. 2020 Apr 27;11(1):2044. doi: 10.1038/s41467-020-15123-0.</p>

scholarly journals Characterization of a Multigene-Encoded Sodium/Hydrogen Antiporter (Sha) from Pseudomonas aeruginosa: Its Involvement in Pathogenesis

2005 ◽  
Vol 187 (15) ◽  
pp. 5242-5248 ◽  
Author(s):  
Saori Kosono ◽  
Koki Haga ◽  
Rui Tomizawa ◽  
Yusuke Kajiyama ◽  
Kazuo Hatano ◽  
...  
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Critical Role ◽  
Opportunistic Pathogen ◽  
Growth Defect ◽  
Monovalent Cations ◽  
Sodium Hydrogen ◽  
Tract Infections ◽  
Transport Complex ◽  
Six Genes

ABSTRACT Sha (also known as Mrp/Mnh/Pha) is a Na+/H+ antiporter encoded by a cluster of six or seven genes that probably form a multisubunit transport complex. The Sha system is important for the homeostasis of H+, Na+, and other monovalent cations and plays a critical role in various functions, including alkaliphily, sporulation, and symbiosis. Here, we characterized the sha homologue genes from the opportunistic pathogen Pseudomonas aeruginosa, which exist as a cluster of six genes (PA1054 to PA1059). The gene cluster PA1054 to PA1059, but not the cluster with a deletion of PA1054, complemented a growth defect in the presence of 0.2 M NaCl and a defect in Na+/H+ antiport activity of the Escherichia coli TO114 mutant lacking the three major Na+/H+ antiporters, indicating that genes PA1054 to PA1059 are responsible for Na+/H+ antiport activity. We disrupted PA1054 (a shaA homologue gene) and determined its effect on Na+ tolerance during growth, Na+ efflux, and pathogenicity in mice. Disruption of PA1054 resulted in severe Na+ sensitivity during growth and decreased Na+ efflux activity. In mice, the deletion mutant of PA1054 also exhibited an attenuated virulence in systemic, pulmonary, and urinary tract infections and also a decrease in colonization of the infected organs. From these results, we conclude that the genes PA1054 to PA1059 encode a Na+/H+ antiporter that is largely responsible for Na+ extrusion in P. aeruginosa and has a role in the infection of the pathogen. We propose to designate PA1054 to PA1059 as the sha (sodium hydrogen antiporter) genes, shaABCDEFG.

scholarly journals Stenotrophomonas maltophilia strains replicate and persist in the murine lung, but to significantly different degrees

Microbiology ◽  
2011 ◽  
Vol 157 (7) ◽  
pp. 2133-2142 ◽  
Author(s):  
Ruella Rouf ◽  
Sara M. Karaba ◽  
Jenny Dao ◽  
Nicholas P. Cianciotto
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Fold Increase ◽  
Multidrug Resistant ◽  
Clinical Isolates ◽  
Mouse Strains ◽  
Mammalian Host ◽  
Virulence Determinants ◽  
Environmental Bacterium ◽  
Bacterial Replication ◽  
Pro Inflammatory Cytokines

The environmental bacterium Stenotrophomonas maltophilia is increasingly described as a multidrug-resistant pathogen of humans, being associated with pneumonia, among other diseases. But the degree to which S. maltophilia is capable of replicating in a mammalian host has been an issue of controversy. Using a model of intranasal inoculation into adult A/J mice, we now document that S. maltophilia strain K279a, the clinical isolate of S. maltophilia whose complete genome sequence was recently determined, is in fact capable of replicating in lungs, displaying as much as a 10-fold increase in c.f.u. in the first 8 h of infection. Importantly, as few as 104 c.f.u. deposited into the A/J lung was sufficient to promote bacterial outgrowth. Bacterial replication in the lungs of the A/J mice was followed by elevations in pro-inflammatory cytokines and also promoted resistance to subsequent challenge. We also found that DBA/2 mice were permissive for S. maltophilia K279a replication, although the level of growth and persistence in these animals was less than it was in the A/J mice. In contrast, the BALB/c and C57BL/6 mouse strains were non-permissive for S. maltophilia K279a growth. Interestingly, when five additional clinical isolates were introduced into the A/J lung, marked differences in survival were observed, with some strains being much less infective than K279a and others being appreciably more infective. These data suggest that the presence of major virulence determinants is variable among clinical isolates. Overall, this study confirms the infectivity of S. maltophilia for the mammalian host, and illustrates how both host and bacterial factors affect the outcome of Stenotrophomonas infection.

scholarly journals Characterization of the Enterobacter Phage vB_EclM_CIP9

2020 ◽  
Vol 9 (13) ◽  
Author(s):  
Klara Wang ◽  
Marielou G. Tamayo ◽  
Tiffany V. Penner ◽  
Bradley W. M. Cook ◽  
Deborah A. Court ◽  
...  
Keyword(s):  
Enterobacter Cloacae ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Open Reading Frames ◽  
Resistant Isolate ◽  
Content Type ◽  
Hospital Acquired Infections ◽  
Hospital Acquired ◽  
Reading Frames

Enterobacter cloacae is an opportunistic pathogen that causes hospital-acquired infections in immunocompromised patients. Here, we describe vB_EclM_CIP9, a novel Enterobacter phage that infects a multidrug-resistant isolate of E. cloacae. Phage vB_EclM_CIP9 is a myovirus that has a 174,924-bp genome, with 296 predicted open reading frames.

scholarly journals Biofilm Formation and Detection of Fluoroquinolone- and Carbapenem-Resistant Genes in Multidrug-Resistant Acinetobacter baumannii

2019 ◽  
Vol 2019 ◽  
pp. 1-5 ◽  
Author(s):  
María-Guadalupe Avila-Novoa ◽  
Oscar-Alberto Solís-Velázquez ◽  
Daniel-Eduardo Rangel-López ◽  
Jean-Pierre González-Gómez ◽  
Pedro-Javier Guerrero-Medina ◽  
...  
Keyword(s):  
Acinetobacter Baumannii ◽  
Biofilm Formation ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Resistance Mechanisms ◽  
Low Grade ◽  
Carbapenem Resistant ◽  
Hospital Environments ◽  
Potential Association ◽  
Clinical Environments

Acinetobacter baumannii is an important opportunistic pathogen that shows resistance to cephalosporins, penicillins, carbapenems, fluoroquinolones, and aminoglycosides, the multiresistance being associated with its ability to form biofilms in clinical environments. The aim of this study was to determine biofilm formation and its potential association with genes involved in antibiotic resistance mechanisms of A. baumannii isolates of different clinical specimens. We demonstrated 100% of the A. baumannii isolates examined to be multidrug resistant (MDR), presenting a 73.3% susceptibility to cefepime and a 53.3% susceptibility to ciprofloxacin. All A. baumannii isolates were positive for blaOXA-51, 33.3% being positive for blaOXA-23 and ISAba1, and 73.3% being positive for gyrA. We found 86.6% of A. baumannii strains to be low-grade biofilm formers and 13.3% to be biofilm negative; culturing on Congo red agar (CRA) plates revealed that 73.3% of the A. baumannii isolates to be biofilm producers, while 26.6% were not. These properties, combined with the role of A. baumannii as a nosocomial pathogen, increase the probability of A. baumannii causing nosocomial infections and outbreaks as a complication during therapeutic treatments and emphasize the need to control A. baumannii biofilms in hospital environments.

scholarly journals Avibactam Restores the Susceptibility of Clinical Isolates of Stenotrophomonas maltophilia to Aztreonam

2017 ◽  
Vol 61 (10) ◽  
Author(s):  
Maria F. Mojica ◽  
Krisztina M. Papp-Wallace ◽  
Magdalena A. Taracila ◽  
Melissa D. Barnes ◽  
Joseph D. Rutter ◽  
...  
Keyword(s):  
Stenotrophomonas Maltophilia ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
World Health ◽  
Combination Therapies ◽  
Content Type ◽  
Medical Need ◽  
The World ◽  
Health Organization

ABSTRACT Stenotrophomonas maltophilia is an emerging opportunistic pathogen, classified by the World Health Organization as one of the leading multidrug-resistant organisms in hospital settings. The need to discover novel compounds and/or combination therapies for S. maltophilia is urgent. We demonstrate the in vitro efficacy of aztreonam-avibactam (ATM-AVI) against S. maltophilia and kinetically characterize the inhibition of the L2 β-lactamase by avibactam. ATM-AVI overcomes aztreonam resistance in selected clinical strains of S. maltophilia, addressing an unmet medical need.

scholarly journals The global phylogenetic landscape and nosocomial spread of the multidrug-resistant opportunist Stenotrophomonas maltophilia

2019 ◽  
Author(s):  
Matthias I Gröschel ◽  
Conor J Meehan ◽  
Ivan Barilar ◽  
Margo Diricks ◽  
Aitor Gonzaga ◽  
...  
Keyword(s):  
Population Structure ◽  
Resistance Genes ◽  
Stenotrophomonas Maltophilia ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Global Level ◽  
Global Spread ◽  
Healthcare Associated ◽  
Globally Distributed ◽  
Hospital Transmission

AbstractRecent studies portend a rising global spread and adaptation of human- or healthcare-associated pathogens. Here, we analysed an international collection of the emerging, multidrug-resistant, opportunistic pathogen Stenotrophomonas maltophilia from 22 countries to infer population structure and clonality at a global level. We show that the S. maltophilia complex is divided into 23 monophyletic lineages, most of which harboured strains of all degrees of human virulence. Lineage Sm6 comprised the highest rate of human-associated strains, linked to key virulence and resistance genes. Transmission analysis identified potential outbreak events of genetically closely related strains isolated within days or weeks in the same hospitals.One Sentence SummaryThe S. maltophilia complex comprises genetically diverse, globally distributed lineages with evidence for intra-hospital transmission.

scholarly journals Successful Treatment of Bloodstream Infection Due to Metallo-β-Lactamase-Producing Stenotrophomonas maltophilia in a Renal Transplant Patient

2016 ◽  
Vol 60 (9) ◽  
pp. 5130-5134 ◽  
Author(s):  
Maria F. Mojica ◽  
Christopher P. Ouellette ◽  
Amy Leber ◽  
M. Brian Becknell ◽  
Monica I. Ardura ◽  
...  
Keyword(s):  
Renal Transplant ◽  
Stenotrophomonas Maltophilia ◽  
Conventional Treatment ◽  
Renal Transplant Patient ◽  
Transplant Patient ◽  
Opportunistic Pathogen ◽  
Multidrug Resistant ◽  
Content Type ◽  
Colistimethate Sodium ◽  
Novel Drug

ABSTRACTStenotrophomonas maltophiliais an emerging multidrug-resistant (MDR) opportunistic pathogen for which new antibiotic options are urgently needed. We report our clinical experience treating a 19-year-old renal transplant recipient who developed prolonged bacteremia due to metallo-β-lactamase-producingS. maltophiliarefractory to conventional treatment. The infection recurred despite a prolonged course of colistimethate sodium (colistin) but resolved with the use of a novel drug combination with clinical efficacy against the patient'sS. maltophiliaisolate.

scholarly journals Characterization of auto-agglutinating and non-typeable uropathogenic Escherichia coli strains

2019 ◽  
Vol 13 (06) ◽  
pp. 465-472
Author(s):  
Ulises Hernández-Chiñas ◽  
Alejandro Pérez-Ramos ◽  
Laura Belmont-Monroy ◽  
María E Chávez-Berrocal ◽  
Edgar González-Villalobos ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Uropathogenic Escherichia Coli ◽  
E Coli ◽  
Resistant Strains ◽  
Tract Infections ◽  
Disk Method

Introduction: Uropathogenic Escherichia coli (UPEC) are the main etiological agent of urinary tract infections (UTIs). Association between different serotypes and UTIs is known, however, some strains are incapable to be serotyped. The aim of this work was to study bthe phenotypical and genotypical characteristics of 113 non-typeable (NT) and auto-agglutinating (AA) E. coli strains, isolated from UTIs in children and adults. Methodology: The 113 UPEC strains were analyzed by PCR assays using specific primers to determine their serogroups, fimH, papC, iutA, sat, hlyCA and cnf1, virulence associated genes, and chuA, yjaA and TSPE4.C2 for phylogroup determination. Additionally, the diffusion disk method was performed to evaluate the antimicrobial resistance to 18 antimicrobial agents. Results: Using the PCR assay, 63% (71) of the strains were genotyped showing O25 and O75 as the most common serogroups. The virulence genes fimH (86%) and iutA (74%) were the most prevalent, in relation to the phylogroups the commensal (A and B1) and virulent (B2 and D) showed similar frequencies (P > 0.05). The antimicrobial susceptibility test showed a high percentage (73%) of multidrug-resistant strains. Conclusions: The genotyping allowed identifying the serogroup in many of the strains that could not be typed by traditional serology. The strains carried virulence genes and were multidrug-resistant in both, commensal and virulent phylogroups. Our findings revealed that, in addition to the classical UPEC serogroups, there are pathogenic serogroups not reported yet.

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