scholarly journals Comparative genomic analyses reveal diverse virulence factors and antimicrobial resistance mechanisms in clinical Elizabethkingia meningoseptica strains

2019 ◽  
Author(s):  
Shicheng Chen ◽  
Marty Soehnlen ◽  
Jochen Blom ◽  
Nicolas Terrapon ◽  
Bernard Henrissat ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Resistance Mechanisms ◽  
Glycoside Hydrolases ◽  
Comparative Genomic ◽  
Two Component System ◽  
Elizabethkingia Meningoseptica ◽  
Protein Encoding ◽  
Genes Encoding ◽  
Encoding Genes ◽  
Transcription Factor Proteins

AbstractThree human clinical isolates of bacteria (designated strains Em1, Em2 and Em3) had high average nucleotide identity (ANI) to Elizabethkingia meningoseptica. Their genome sizes (3.89, 4.04 and 4.04 Mb) were comparable to those of other Elizabethkingia species and strains, and exhibited open pan-genome characteristics, with two strains being nearly identical and the third divergent. These strains were susceptible only to trimethoprim/sulfamethoxazole and ciprofloxacin amongst 16 antibiotics in minimum inhibitory tests. The resistome exhibited a high diversity of resistance genes, including 5 different lactamase- and 18 efflux protein-encoding genes. Forty-four genes encoding virulence factors were conserved among the strains. Sialic acid transporters and curli synthesis genes were well conserved in E. meningoseptica but absent in E. anophelis and E. miricola. E. meningoseptica carried several genes contributing to biofilm formation. 58 glycoside hydrolases (GH) and 25 putative polysaccharide utilization loci (PULs) were found. The strains carried numerous genes encoding two-component system proteins (56), transcription factor proteins (187~191), and DNA-binding proteins (6~7). Several prophages and CRISPR/Cas elements were uniquely present in the genomes.

scholarly journals Identification and Characterization of Hemolysin-Like Proteins Similar to RTX Toxin in Pasteurella pneumotropica

2009 ◽  
Vol 191 (11) ◽  
pp. 3698-3705 ◽  
Author(s):  
Hiraku Sasaki ◽  
Eiichi Kawamoto ◽  
Yoshikazu Tanaka ◽  
Takuo Sawada ◽  
Satoshi Kunita ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Opportunistic Pathogen ◽  
Pcr Analysis ◽  
Type I ◽  
Secretion Systems ◽  
Rtx Toxin ◽  
Rtx Toxins ◽  
Genes Encoding ◽  
Encoding Genes

ABSTRACT Pasteurella pneumotropica is an opportunistic pathogen that causes lethal pneumonia in immunodeficient rodents. The virulence factors of this bacterium remain unknown. In this study, we identified the genes encoding two RTX toxins, designated as pnxI and pnxII, from the genomic DNA of P. pneumotropica ATCC 35149 and characterized with respect to hemolysis. The pnxI operon was organized according to the manner in which the genes encoded the structural RTX toxin (pnxIA), the type I secretion systems (pnxIB and pnxID), and the unknown orf. The pnxII gene was involved only with the pnxIIA that coded for a structural RTX toxin. Both the structural RTX toxins of deduced PnxIA and PnxIIA were involved in seven of the RTX repeat and repeat-like sequences. By quantitative PCR analysis of the structural RTX toxin-encoding genes in P. pneumotropica ATCC 35149, the gene expression of pnxIA was found to have increased from the early log phase, while that of pnxIIA increased from the late log to the early stationary phase. As expressed in Escherichia coli, both the recombinant proteins of PnxIA and PnxIIA showed weak hemolytic activity in both sheep and murine erythrocytes. On the basis of the results of the Southern blotting analysis, the pnxIA gene was detected in 82% of the isolates, while the pnxIIA gene was detected in 39%. These results indicate that the products of both pnxIA and pnxIIA were putative associations of virulence factors in the rodent pathogen P. pneumotropica.

scholarly journals MOLECULAR DETECTION OF PROTEIN ENCODING GENES Virb11 ON BRUCELLA ABORTUS LOCAL ISOLATES ORIGIN OF PINRANG, NTT AND VACCINE STRAINS

2020 ◽  
Vol 21 (4) ◽  
pp. 503-511
Author(s):  
Maria Gladis Bupu Maze ◽  
Didik Handijatno ◽  
Wiwik Tyasningsih ◽  
Suwarno Suwarno ◽  
Agnes Theresia Soelih Estoepangestie ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Virulence Factor ◽  
Brucella Abortus ◽  
Molecular Detection ◽  
Livestock Population ◽  
Gram Staining ◽  
Protein Encoding ◽  
Important Virulence Factor ◽  
Pcr Method ◽  
Encoding Genes

Brucellosis in cattle is a disease caused by Brucella abortus due to the reduction in livestock population caused by abortion, stillbirth, weak birth, infertility and sterility. Brucella abortus has several potential virulence factors, i.e. virB11 gene that encodes VirB11 protein is an important virulence factor acts as an ATPase for assembling organelles when the bacteria replicate, helping to complete the bacterial cycle and agress to another cells. The aim of this study are to re-identification Brucella abortus and detect virB11 gene as encoding of B. abortus VirB11 protein in local isolates from Pinrang, NTT, strain vaccines S19 and RB51. The isolates Brucella abortus were re-cultured in Brucella agar base and re-identification is followed by microscopic with Gram staining and biochemical tested with urease, citrat, indol and TSIA test. virB11gene was detected with PCR method. The PCR result showed virB11 gene have DNA band 720 bp. virB11 gene are present in local isolates from Pinrang, NTT, strain vaccines S19 and RB51.

scholarly journals Identification of Genetic Bases ofVibrio fluvialisSpecies-Specific Biochemical Pathways and Potential Virulence Factors by Comparative Genomic Analysis

2014 ◽  
Vol 80 (6) ◽  
pp. 2029-2037 ◽  
Author(s):  
Xin Lu ◽  
Weili Liang ◽  
Yunduan Wang ◽  
Jialiang Xu ◽  
Jun Zhu ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Genomic Analysis ◽  
Comparative Genomic Analysis ◽  
Comparative Genomic ◽  
Type Vi Secretion System ◽  
Biochemical Tests ◽  
Regulatory Pathways ◽  
Vibrio Fluvialis ◽  
Genes Encoding ◽  
Genetic Mechanisms

ABSTRACTVibrio fluvialisis an important food-borne pathogen that causes diarrheal illness and sometimes extraintestinal infections in humans. In this study, we sequenced the genome of a clinicalV. fluvialisstrain and determined its phylogenetic relationships with otherVibriospecies by comparative genomic analysis. We found that the closest relationship was betweenV. fluvialisandV. furnissii, followed by those withV. choleraeandV. mimicus. Moreover, based on genome comparisons and gene complementation experiments, we revealed genetic mechanisms of the biochemical tests that differentiateV. fluvialisfrom closely related species. Importantly, we identified a variety of genes encoding potential virulence factors, including multiple hemolysins, transcriptional regulators, and environmental survival and adaptation apparatuses, and the type VI secretion system, which is indicative of complex regulatory pathways modulating pathogenesis in this organism. The availability ofV. fluvialisgenome sequences may promote our understanding of pathogenic mechanisms for this emerging pathogen.

scholarly journals Molecular Characterization of Baseline Enterobacterales and Pseudomonas aeruginosa Isolates from a Phase 3 Nosocomial Pneumonia (ASPECT-NP) Clinical Trial

2020 ◽  
pp. AAC.02461-20
Author(s):  
Mariana Castanheira ◽  
Matthew G. Johnson ◽  
Brian Yu ◽  
Jennifer A. Huntington ◽  
Patricia Carmelitano ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Pseudomonas Aeruginosa ◽  
Nosocomial Pneumonia ◽  
Resistance Mechanisms ◽  
Quantitative Real Time Pcr ◽  
Phase 3 ◽  
Genes Encoding ◽  
Elevated Expression ◽  
Encoding Genes

We evaluated β-lactam-resistant Enterobacterales species and Pseudomonas aeruginosa baseline lower respiratory tract isolates collected during the ASPECT-NP phase 3 clinical trial evaluating the safety and efficacy of ceftolozane-tazobactam compared with meropenem for treatment of ventilated nosocomial pneumonia in adults. Isolates were subjected to whole genome sequencing, quantitative real-time PCR for quantification of the expression levels of β-lactamase and efflux genes, and Western blot analysis for detection of OprD (P. aeruginosa only). ESBL genes were detected in 168 of 262 Enterobacterales isolates and among these blaCTXM-15 was the most common, detected in 125 isolates. Sixty-one Enterobacterales carried genes encoding carbapenemases while 33 isolates did not carry ESBLs or carbapenemases. Carbapenemase-producing isolates carried mainly NDM and OXA-48 variants, with ceftolozane-tazobactam MIC values ranging from 4 to 128 μg/mL. Most ceftolozane-tazobactam-nonsusceptible Enterobacterales isolates that did not carry carbapenemases were K. pneumoniae that exhibited disrupted OmpK35, specific mutations in OmpK36, and, in some isolates, elevated expression of blaCTXM-15. Among 89 P. aeruginosa isolates, carbapenemases and ESBL-encoding genes were observed among 12 and 22 isolates, respectively. P. aeruginosa isolates without acquired β-lactamases displaying elevated expression of AmpC (14 isolates), elevated expression of efflux pumps (11 isolates), and/or decrease or loss of OprD (22 isolates) were susceptible to ceftolozane-tazobactam. Ceftolozane-tazobactam was active against >75% of the Enterobacterales isolates from the ASPECT-NP trial that did not carry carbapenemases. K. pneumoniae resistant to ceftolozane-tazobactam might represent a challenge for treatment due to its multiple resistance mechanisms. Ceftolozane-tazobactam was among the agents displaying the greatest activity against P. aeruginosa isolates.

scholarly journals Identification of Three Genes Encoding PII-Like Proteins in Gluconacetobacter diazotrophicus: Studies of Their Role(s) in the Control of Nitrogen Fixation

2003 ◽  
Vol 185 (19) ◽  
pp. 5854-5861 ◽  
Author(s):  
Olena Perlova ◽  
Alejandro Ureta ◽  
Stefan Nordlund ◽  
Dietmar Meletzus
Keyword(s):  
Gene Expression ◽  
Nitrogen Fixation ◽  
Gluconacetobacter Diazotrophicus ◽  
Triple Mutant ◽  
Gene Encoding ◽  
Protein Encoding ◽  
Genes Encoding ◽  
Encoding Gene ◽  
Encoding Genes ◽  
Expression And Activity

ABSTRACT In our studies on the regulation of nitrogen metabolism in Gluconacetobacter diazotrophicus, an endophytic diazotroph of sugarcane, three glnB-like genes were identified and their role(s) in the control of nitrogen fixation was studied. Sequence analysis revealed that one PII protein-encoding gene, glnB, was adjacent to a glnA gene (encoding glutamine synthetase) and that two other PII protein-encoding genes, identified as glnK1 and glnK2, were located upstream of amtB1 and amtB2, respectively, genes which in other organisms encode ammonium (or methylammonium) transporters. Single and double mutants and a triple mutant with respect to the three PII protein-encoding genes were constructed, and the effects of the mutations on nitrogenase expression and activity in the presence of either ammonium starvation or ammonium sufficiency were studied. Based on the results presented here, it is suggested that none of the three PII homologs is required for nif gene expression, that the GlnK2 protein acts primarily as an inhibitor of nif gene expression, and that GlnB and GlnK1 control the expression of nif genes in response to ammonium availability, both directly and by relieving the inhibition by GlnK2. This model includes novel regulatory features of PII proteins.

scholarly journals IDENTIFICATION TARGETED ON toxR GENE AND DETECTION OF VIRULENT FACTOR ENCODING GENES ON Vibrio parahaemolyticus ISOLATED FROM RAW CHICKEN MEAT

2011 ◽  
Vol 2 (1) ◽  
pp. 7-11
Author(s):  
Eka Fitrianda
Keyword(s):  
Virulence Factors ◽  
Chicken Meat ◽  
Specific Gene ◽  
Gene Encoding ◽  
Genes Encoding ◽  
Thermostable Direct Hemolysin ◽  
Pcr Method ◽  
Toxr Gene ◽  
Meat Samples ◽  
Encoding Genes

A number of V. parahaemolyticus isolates has been isolated from raw chicken meat samples collected in Pasar raya Padang. Isolation was done using ChromagarTM Vibrio media. Identification of toxR gene was then done to these isolates. toxR is a very specific gene in V. parahaemolyticus species. Detection for the presence of genes encoding virulence factors, in this case were the gene encoding thermostable direct hemolysin (tdh) and TDH related hemolysin (trh) was performed on toxR positive V. parahaemolyticus isolates. Identification of toxR gene and detection of tdh and trh genes were done trough amplification using polymerase chain reaction PCR (method). The results showed that all of the tested V. parahaemolyticus isolates (22 isolates) had toxR gene, but none of isolates has gene encoding the production of virulence factors both tdh and trh.

scholarly journals Virulence Factors of Enteric Pathogenic Escherichia coli: A Review

2021 ◽  
Vol 22 (18) ◽  
pp. 9922
Author(s):  
Babak Pakbin ◽  
Wolfram M. Brück ◽  
John W. A. Rossen
Keyword(s):  
Escherichia Coli ◽  
Virulence Factors ◽  
Host Cells ◽  
New Developments ◽  
E Coli ◽  
Factors Associated ◽  
Pathogenic Escherichia Coli ◽  
Genes Encoding ◽  
Tract Infections ◽  
Encoding Genes

Escherichia coli are remarkably versatile microorganisms and important members of the normal intestinal microbiota of humans and animals. This harmless commensal organism can acquire a mixture of comprehensive mobile genetic elements that contain genes encoding virulence factors, becoming an emerging human pathogen capable of causing a broad spectrum of intestinal and extraintestinal diseases. Nine definite enteric E. coli pathotypes have been well characterized, causing diseases ranging from various gastrointestinal disorders to urinary tract infections. These pathotypes employ many virulence factors and effectors subverting the functions of host cells to mediate their virulence and pathogenesis. This review summarizes new developments in our understanding of diverse virulence factors associated with encoding genes used by different pathotypes of enteric pathogenic E. coli to cause intestinal and extraintestinal diseases in humans.

scholarly journals Antibiotic resistance, virulence, and phylogenetic analysis of Escherichia coli strains isolated from free-living birds in human habitats

PLoS ONE ◽  
2022 ◽  
Vol 17 (1) ◽  
pp. e0262236
Author(s):  
Bartosz Rybak ◽  
Beata Krawczyk ◽  
Beata Furmanek-Blaszk ◽  
Magdalena Wysocka ◽  
Magdalena Fordon ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Virulence Factors ◽  
Iron Acquisition ◽  
Antibiotic Resistance Genes ◽  
Resistance Mechanisms ◽  
Wild Birds ◽  
Phylogenetic Groups ◽  
Faecal Samples ◽  
Class 1 ◽  
Genes Encoding

Wild birds can be colonized by bacteria, which are often resistant to antibiotics and have various virulence profiles. The aim of this study was to analyze antibiotic resistance mechanisms and virulence profiles in relation to the phylogenetic group of E. coli strains that were isolated from the GI tract of wildfowl. Out of 241 faecal samples, presence of E. coli resistant to a cephalosporin (ESBL/AmpC) was estimated for 33 isolates (13,7%). Based on the analysis of the coexistence of 4 genes encoding ESBLs/AmpC (blaCTX-M, blaTEM, blaSHV, blaAmpC) and class 1 and 2 integrons genes (intI1, intI2) a subset of two resistance profiles was observed among the investigated E. coli isolates carrying blaAmpC, blaSHV, and blaCTX-M, blaTEM, class 1 and 2 integrons, respectively. The E. coli isolates were categorized into 4 phylogenetic groups A (39.4%), B2 (24.25%), D (24.25%) and B1 (12.1%). The pathogenic B2 and D groups were mainly typical for the Laridae family. Among the 28 virulence factors (Vfs) detected in pathogenic phylogenetic groups B2 and D, 7 were exclusively found in those groups (sfa, vat, tosA, tosB, hly, usp, cnf), while 4 VFs (fecA, fyuA, irp2, kspMTII) showed a statistically significant association (P≤0.05) with phylogroups A and B1. Our results indicated that strains belonging to commensal phylogroups A/B1 possess extensive iron acquisition systems (93,9%) and autotransporters (60,6%), typical for pathogens, hence we suggest that these strains evolve towards higher levels of virulence. This study, which is a point assessment of the virulence and drug resistance potential of wild birds, confirms the importance of taking wild birds as a reservoir of strains that pose a growing threat to humans. The E. coli analyzed in our study derive from different phylogenetic groups and possess an arsenal of antibiotic resistance genes and virulence factors that contribute to their ability to cause diseases.

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