scholarly journals Analysis and Comparative Genomics of the SXT/R391 Family ICE, pMERPH

Author(s):  
Michael P. Ryan ◽  
Shannon Slattery ◽  
J. Tony Pembroke

The aim of this study was to analyse pMERPH, the first integrative and conjugative element (ICE) of the SXT/R391 family isolated in the United Kingdom and to determine its relationship to other members of the SXT/R391 family of ICEs. Whole Genome Sequencing of Escherichia coli isolate KH802 (which contains the ICE pMERPH) was performed using Illumina sequencing technology. pMERPH was evaluated by de novo assembly of the sequenced genome, via gene prediction and annotation tools, and phenotypic analysis via comparative genomics to other members of the SXT/R391 ICEs. pMERPH has a size of 110 Kb and has 112 predicted ORFs making it one of the bigger SXT/R391 ICE’s thus far characterised. The “Hotspot regions” of the element were found to contain putative restriction digestion systems, insertion sequences and heavy metal resistance genes that give resistance to mercury and arsenate. pMERPH is closely related to the SXT-like elements from widely dispersed geographic areas. The sequencing of pMERPH increases the knowledge of the earliest isolated SXT/R391family members and may provide insight on the emergence of such elements.

2009 ◽  
Vol 71-73 ◽  
pp. 143-150 ◽  
Author(s):  
David S. Holmes ◽  
Juan Pablo Cárdenas ◽  
Jorge H. Valdés ◽  
Raquel Quatrini ◽  
M. Esparza ◽  
...  

The metabolic potential of 16 bioleaching microorganisms (Eubacteria and Archaea) has been investigated, allowing the prediction of potential inter- and intra-species physiological interactions (ecophysiology) during spatial and temporal changes that are known to occur within industrial bioleaching heaps. Genome analysis has allowed preliminary models to be built for genes and pathways involved in key processes such as nitrogen and carbon cycling, sulfur and iron uptake and homeostasis, extra-cellular polysaccharide biosynthesis, heavy metal resistance and energy metabolism. This paper will focus on the diverse ways that microorganisms obtain carbon from their environment with a particular emphasis on elucidating how these processes might be expected to vary over space and time during the lifetime of a bioleaching operation. It is anticipated that this knowledge will improve our understanding of fundamental biological processes in extremely acidic environments and it is hoped that it will capture usable knowledge that can be applied to bioleaching. Comparative genomics between two strains of Acidthiobacillus ferrooxidans highlights the importance of lateral gene transfer in increasing genetic and metabolic potential and suggests that classical molecular DNA techniques, such as rDNA typing, significantly underestimate the microbial diversity of bioleaching heaps.


2020 ◽  
Vol 11 ◽  
Author(s):  
Erika Corretto ◽  
Livio Antonielli ◽  
Angela Sessitsch ◽  
Christoph Höfer ◽  
Markus Puschenreiter ◽  
...  

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.


Author(s):  
Kashaf Junaid ◽  
Hasan Ejaz ◽  
Iram Asim ◽  
Sonia Younas ◽  
Humaira Yasmeen ◽  
...  

This study evaluates bacteriological profiles in ready-to-eat (RTE) foods and assesses antibiotic resistance, extended-spectrum β-lactamase (ESBL) production by gram-negative bacteria, and heavy metal tolerance. In total, 436 retail food samples were collected and cultured. The isolates were screened for ESBL production and molecular detection of ESBL-encoding genes. Furthermore, all isolates were evaluated for heavy metal tolerance. From 352 culture-positive samples, 406 g-negative bacteria were identified. Raw food samples were more often contaminated than refined food (84.71% vs. 76.32%). The predominant isolates were Klebsiella pneumoniae (n = 76), Enterobacter cloacae (n = 58), and Escherichia coli (n = 56). Overall, the percentage of ESBL producers was higher in raw food samples, although higher occurrences of ESBL-producing E. coli (p = 0.01) and Pseudomonas aeruginosa (p = 0.02) were observed in processed food samples. However, the prevalence of ESBL-producing Citrobacter freundii in raw food samples was high (p = 0.03). Among the isolates, 55% were blaCTX-M, 26% were blaSHV, and 19% were blaTEM. Notably, heavy metal resistance was highly prevalent in ESBL producers. These findings demonstrate that retail food samples are exposed to contaminants including antibiotics and heavy metals, endangering consumers.


2021 ◽  
Vol 9 (3) ◽  
pp. 499
Author(s):  
Majid Rasool Kamli ◽  
Nada A. Y. Alzahrani ◽  
Nahid H. Hajrah ◽  
Jamal S. M. Sabir ◽  
Adeel Malik

Bacteria belonging to the genus Aneurinibacillus within the family Paenibacillaceae are Gram-positive, endospore-forming, and rod-shaped bacteria inhabiting diverse environments. Currently, there are eight validly described species of Aneurinibacillus; however, several unclassified species have also been reported. Aneurinibacillus spp. have shown the potential for producing secondary metabolites (SMs) and demonstrated diverse types of enzyme activities. These features make them promising candidates with industrial implications. At present, genomes of 9 unique species from the genus Aneurinibacillus are available, which can be utilized to decipher invaluable information on their biosynthetic potential as well as enzyme activities. In this work, we performed the comparative genome analyses of nine Aneurinibacillus species representing the first such comprehensive study of this genus at the genome level. We focused on discovering the biosynthetic, biodegradation, and heavy metal resistance potential of this under-investigated genus. The results indicate that the genomes of Aneurinibacillus contain SM-producing regions with diverse bioactivities, including antimicrobial and antiviral activities. Several carbohydrate-active enzymes (CAZymes) and genes involved in heavy metal resistance were also identified. Additionally, a broad range of enzyme classes were also identified in the Aneurinibacillus pan-genomes, making this group of bacteria potential candidates for future investigations with industrial applications.


1995 ◽  
Vol 18 (3) ◽  
pp. 191-203 ◽  
Author(s):  
Eva M. Top ◽  
Helene Rore ◽  
Jean-Marc Collard ◽  
Veerle Gellens ◽  
Galina Slobodkina ◽  
...  

2000 ◽  
Vol 182 (8) ◽  
pp. 2170-2178 ◽  
Author(s):  
Neville Firth ◽  
Sumalee Apisiridej ◽  
Tracey Berg ◽  
Brendon A. O'Rourke ◽  
Steve Curnock ◽  
...  

ABSTRACT Based on structural and functional properties, three groups of large staphylococcal multiresistance plasmids have been recognized, viz., the pSK1 family, pSK41-like conjugative plasmids, and β-lactamase–heavy-metal resistance plasmids. Here we describe an analysis of the replication functions of a representative of each of these plasmid groups. The replication initiation genes from theStaphylococcus aureus plasmids pSK1, pSK41, and pI9789::Tn552 were found to be related to each other and to the Staphylococcus xylosus plasmid pSX267 and are also related to rep genes of several plasmids from other gram-positive genera. Nucleotide sequence similarity between pSK1 and pI9789::Tn552 extended beyond theirrep genes, encompassing upstream divergently transcribed genes, orf245 and orf256, respectively. Our analyses revealed that genes encoding proteins related to the deducedorf245 product are variously represented, in several types of organization, on plasmids possessing six seemingly evolutionarily distinct types of replication initiation genes and including both theta-mode and rolling-circle replicons. Construction of minireplicons and subsequent functional analysis demonstrated that orf245is required for the segregational stability of the pSK1 replicon. In contrast, no gene equivalent to orf245 is evident on the conjugative plasmid pSK41, and a minireplicon encoding only the pSK41 rep gene was found to exhibit a segregational stability approaching that of the parent plasmid. Significantly, the results described establish that many of the large multiresistance plasmids that have been identified in clinical staphylococci, which were formerly presumed to be unrelated, actually utilize an evolutionarily related theta-mode replication system.


2021 ◽  
Vol 19 ◽  
Author(s):  
Manzar Alam ◽  
Mohd Imran ◽  
Syed Sayeed Ahmad

Background: Microbial resistance to antibiotics and heavy metals is a rising problem in the world today. All the Proteus vulgaris isolates showed their MIC in between 50-1600 µg/ml. Of 70% and 46% of the isolates showed their MIC at 800-1200 µg/ml against Zn2+ and Cu2+ while 80% of the isolates showed their MIC at 100-200 µg/ml against Ni2+, respectively. All Proteus vulgaris isolates also exhibited multiple resistance patterns (2-7 heavy metals) in different combination of metals. The Multi metal resistance Index (MHMR) ranges were found (0.04-0.5). Methods: A high level of antibiotics resistance was observed against Methicillin (100%) and least to Oflaxicin (6%), Gentamycine and Neomycin (10%). All Proteus vulgaris isolates also showed multiple drug resistance patterns (2-12 antibiotics) in different combination of antibiotics. The MAR index ranges were found (0.02-0.7). Of 98%, 84% and 80% of the total isolates showed urease, gelatinase and amylase activity. Results: The Proteus vulgaris isolates contained plasmid of size ranging from 42.5 to 57.0kb and molecular weight of plasmids ranged from 27.2 to 37.0 MD. Incidences of resistance transfer, 7 pairs of isolates were assessed for the transfer of the antibiotic/ heavy metal resistance markers. The higher (4.4x10-1 and 3.4x10-1) transfer frequency was observed among antibiotic and heavy metal while lower transfer frequency were (5.0x10-2 and 1.0x10-2) showed against antibiotic and heavy metal in both the medium from the entire site tested, respectively. Conclusion: Indicating the high threat of environmental pollution and appearance of heavy metal resistance which may support the enlargement of resistance to antibiotics among the pathogens.


2018 ◽  
Vol 63 (2) ◽  
pp. e01718-18 ◽  
Author(s):  
Srijan Ranjitkar ◽  
Adriana K. Jones ◽  
Mina Mostafavi ◽  
Zachary Zwirko ◽  
Oleg Iartchouk ◽  
...  

ABSTRACT Efflux pumps contribute to antibiotic resistance in Gram-negative pathogens. Correspondingly, efflux pump inhibitors (EPIs) may reverse this resistance. D13-9001 specifically inhibits MexAB-OprM in Pseudomonas aeruginosa. Mutants with decreased susceptibility to MexAB-OprM inhibition by D13-9001 were identified, and these fell into two categories: those with alterations in the target MexB (F628L and ΔV177) and those with an alteration in a putative sensor kinase of unknown function, PA1438 (L172P). The alterations in MexB were consistent with reported structural studies of the D13-9001 interaction with MexB. The PA1438L172P alteration mediated a >150-fold upregulation of MexMN pump gene expression and a >50-fold upregulation of PA1438 and the neighboring response regulator gene, PA1437. We propose that these be renamed mmnR and mmnS for MexMN regulator and MexMN sensor, respectively. MexMN was shown to partner with the outer membrane channel protein OprM and to pump several β-lactams, monobactams, and tazobactam. Upregulated MexMN functionally replaced MexAB-OprM to efflux these compounds but was insusceptible to inhibition by D13-9001. MmnSL172P also mediated a decrease in susceptibility to imipenem and biapenem that was independent of MexMN-OprM. Expression of oprD, encoding the uptake channel for these compounds, was downregulated, suggesting that this channel is also part of the MmnSR regulon. Transcriptome sequencing (RNA-seq) of cells encoding MmnSL172P revealed, among other things, an interrelationship between the regulation of mexMN and genes involved in heavy metal resistance.


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