scholarly journals Structural and biochemical analysis of OrfG: the VirB8-like component of the integrative and conjugative element ICESt3 from Streptococcus thermophilus

2020 ◽  
Author(s):  
Julien Cappele ◽  
Abbas Mohamad-Ali ◽  
Nathalie Leblond-Bourget ◽  
Sandrine Mathiot ◽  
Tiphaine Dhalleine ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Pathogenic Bacteria ◽  
Quaternary Structure ◽  
Structural Alignment ◽  
Antibiotic Resistance Genes ◽  
Streptococcus Thermophilus ◽  
Conjugative Transfer ◽  
Structural Level ◽  
Secretion Systems ◽  
Integrative And Conjugative Elements

AbstractConjugative transfer is a major threat to global health since it contributes to the spread of antibiotic resistance genes and virulence factors among commensal and pathogenic bacteria. To allow their transfer, mobile genetic elements including Integrative and Conjugative Elements (ICEs) use a specialized conjugative apparatus related to Type IV secretion systems (Conj-T4SS). Therefore, Conj-T4SSs are excellent targets for strategies that aim to limit the spread of antibiotic resistance. In this study, we combined structural, biochemical and biophysical approaches to study OrfG, a protein that belongs to Conj-T4SS of ICESt3 from Streptococcus thermophilus. Structural analysis of OrfG by X-ray crystallography revealed that OrfG central domain is similar to VirB8-like proteins but displays a different quaternary structure in the crystal. To understand, at a structural level, the common and the diverse features between VirB8-like proteins from both Gram-negative and -positive bacteria, we used an in silico structural alignment method that allowed us to identify different structural classes of VirB8-like proteins. Biochemical and biophysical characterizations of purified OrfG soluble domain and its central and C-terminal subdomains indicated that they are mainly monomeric in solution but able to form an unprecedented 6-mer oligomers. Our study provides new insights into the structural and assembly mode of VirB8-like proteins, a component essential for conjugative transfer and improves our understanding on these under-examined bacterial nanomachines.

scholarly journals Structural and Biochemical Analysis of OrfG: The VirB8-like Component of the Conjugative Type IV Secretion System of ICESt3 From Streptococcus thermophilus

2021 ◽  
Vol 8 ◽  
Author(s):  
Julien Cappele ◽  
Abbas Mohamad Ali ◽  
Nathalie Leblond-Bourget ◽  
Sandrine Mathiot ◽  
Tiphaine Dhalleine ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Structural Analysis ◽  
Pathogenic Bacteria ◽  
Quaternary Structure ◽  
Streptococcus Thermophilus ◽  
Type Iv Secretion ◽  
Conjugative Transfer ◽  
Structural Level ◽  
Secretion Systems ◽  
Type Iv

Conjugative transfer is a major threat to global health since it contributes to the spread of antibiotic resistance genes and virulence factors among commensal and pathogenic bacteria. To allow their transfer, mobile genetic elements including Integrative and Conjugative Elements (ICEs) use a specialized conjugative apparatus related to Type IV secretion systems (Conj-T4SS). Therefore, Conj-T4SSs are excellent targets for strategies that aim to limit the spread of antibiotic resistance. In this study, we combined structural, biochemical and biophysical approaches to study OrfG, a protein that belongs to Conj-T4SS of ICESt3 from Streptococcus thermophilus. Structural analysis of OrfG by X-ray crystallography revealed that OrfG central domain is similar to VirB8-like proteins but displays a different quaternary structure in the crystal. To understand, at a structural level, the common and the diverse features between VirB8-like proteins from both Gram-negative and -positive bacteria, we used an in silico structural alignment method that allowed us to identify different structural classes of VirB8-like proteins. Biochemical and biophysical characterizations of purified OrfG soluble domain and its central and C-terminal subdomains indicated that they are mainly monomeric in solution but able to form an unprecedented 6-mer oligomers. Our study provides new insights into the structural analysis of VirB8-like proteins and discusses the interplay between tertiary and quaternary structures of these proteins as an essential component of the conjugative transfer.

scholarly journals COVID-19 Lockdowns May Reduce Resistance Genes Diversity in the Human Microbiome and the Need for Antibiotics

2021 ◽  
Vol 22 (13) ◽  
pp. 6891
Author(s):  
João S. Rebelo ◽  
Célia P. F. Domingues ◽  
Francisco Dionisio ◽  
Manuel C. Gomes ◽  
Ana Botelho ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Bacterial Resistance ◽  
Human Microbiome ◽  
Antibiotic Resistance Genes ◽  
Public Health Problem ◽  
Small World ◽  
Physical Contact ◽  
Hygiene Measures

Recently, much attention has been paid to the COVID-19 pandemic. Yet bacterial resistance to antibiotics remains a serious and unresolved public health problem that kills hundreds of thousands of people annually, being an insidious and silent pandemic. To contain the spreading of the SARS-CoV-2 virus, populations confined and tightened hygiene measures. We performed this study with computer simulations and by using mobility data of mobile phones from Google in the region of Lisbon, Portugal, comprising 3.7 million people during two different lockdown periods, scenarios of 40 and 60% mobility reduction. In the simulations, we assumed that the network of physical contact between people is that of a small world and computed the antibiotic resistance in human microbiomes after 180 days in the simulation. Our simulations show that reducing human contacts drives a reduction in the diversity of antibiotic resistance genes in human microbiomes. Kruskal–Wallis and Dunn’s pairwise tests show very strong evidence (p < 0.000, adjusted using the Bonferroni correction) of a difference between the four confinement regimes. The proportion of variability in the ranked dependent variable accounted for by the confinement variable was η2 = 0.148, indicating a large effect of confinement on the diversity of antibiotic resistance. We have shown that confinement and hygienic measures, in addition to reducing the spread of pathogenic bacteria in a human network, also reduce resistance and the need to use antibiotics.

scholarly journals Modified U-Tube for Ruling out Naked DNA Transfer during Conjugation and Application in Antibiotic Resistance Genes Transfer Research

Water ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 1313
Author(s):  
Ning Zhang ◽  
Xiang Liu ◽  
Bing Li ◽  
Limei Han ◽  
Xuejiao Ma ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Public Health Issue ◽  
Primary Concern ◽  
Conjugative Transfer ◽  
Donor Strain ◽  
Global Public Health ◽  
Pseudomonas Putida Kt2440 ◽  
Naked Dna

Antibiotic resistance is currently a major global public health issue. In particular, the emergence and transfer of antibiotic resistance genes (ARGs) is a matter of primary concern. This study presented a method for ruling out the transfer of naked DNA (plasmid RP4 lysed from donor cells) during the cell-to-cell conjugation, using a modified “U-tube”. A series of gene transfer assays was conducted in both flask and modified U-tube, using Pseudomonas putida KT2440 (P. putida (RP4)) harboring the RP4 plasmid as the donor strain, Escherichia coli (E. coli, ATCC 25922) in pure culture as sole recipient, and bacteria from reclaimed water microcosms as multi-recipients. The verification experiments showed that the U-tube device could prevent direct contact of bacteria without affecting the exchange of free plasmid. In the experiments involving a sole recipient, the transconjugants were obtained in flask samples, but not in modified U-tube. Furthermore, in experiments involving multi-recipients, transfer of naked DNA in the modified U-tube accounted for 5.18% in the transfer frequency of the flask transfer experiment. The modified U-tube proved to be useful for monitoring the interference of naked DNA in the research of conjugative transfer and calculating the exact conjugative transfer rate. This device is identified as a promising candidate for distinguishing different gene transfers in practical application because of its convenient use and easy and simple manufacture.

scholarly journals Monitoring and Evaluation of Antibiotic Resistance Genes in Three Rivers in Northeast China

2021 ◽  
Author(s):  
Chen Zhao ◽  
Chenyu Li ◽  
Xiaoming Wang ◽  
Zhuosong Cao ◽  
Chao Gao ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
River Water ◽  
Resistance Genes ◽  
Northeast China ◽  
Pathogenic Bacteria ◽  
Respiratory Infections ◽  
Antibiotic Resistance Genes ◽  
Distribution Characteristics ◽  
Beta Lactam ◽  
Three Rivers

Abstract Background: Antibiotic resistance genes (ARGs) have become an important public health problem. In this study, we used metagenomic sequencing to analyze the composition of ARGs in certain original habitats of northeast China, comprising three different rivers and riverbank soils of the Heilongjiang River, Tumen River, and Yalu River. Results: Twenty types of ARG were detected in every water sample. The major ARGs were multidrug resistance genes, at approximately 0.5 copies/16s rRNA, accounting for 57.5% of the total ARG abundance. The abundance of multidrug, bacitracin, beta-lactam, macrolide‑lincosamide‑streptogramin, sulfonamide, fosmidomycin, and polymyxin resistance genes covered 96.9% of the total ARG abundance. No significant ecological boundary of ARG diversity was observed. The compositions of the resistance genes in the three rivers were very similar to each other, and 92.1% of ARG subtypes were shared by all water samples. Except for vancomycin resistance genes, almost all ARGs in riverbank soils were detected in the river water. About 31.05% ARGs were carried by Pseudomonas. Opportunistic pathogenic bacteria carrying resistance genes were mainly related to diarrhea and respiratory infections. Multidrug and beta-lactam resistance genes correlated positively with mobile genetic elements (MGEs), indicating a potential risk of diffusion.Conclusions: The composition of ARGs in three different rivers was similar, indicating that climate played an important role in ARG occurrence. ARG subtypes in river water were almost completely the same as those in riverbank soil. ARGs had no significant geographical distribution characteristics. Many ARGs were carried by human pathogenic bacteria related to human diarrhea and respiratory infections, such as Pseudomonas aeruginosa and Aeromonas caviae. In general, our results provide a valuable dataset of river water ARG distribution in northeast China. The related ecological geography distribution characteristics should be further explored.

Genome Assessment of Antibiotic Resistance Genes in Probiotic Bacteria and a Literature Review

2021 ◽  
Author(s):  
Mehdi Fatahi-Bafghi ◽  
Sara Naseri ◽  
Ali Alizehi
Keyword(s):  
Antibiotic Resistance ◽  
Genome Sequence ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Antibiotic Resistance Genes ◽  
Probiotic Bacteria ◽  
Whole Genome Sequence ◽  
Probiotic Properties ◽  
Antibiotic Resistant ◽  
To Come

Abstract Having various clinical applications, probiotic bacteria are currently used in the diet. There are reports of antibiotic resistance genes (ARGs) in these bacteria that can be transferred to other microflora and pathogenic bacteria. The aim of the study is to examine whole-genome sequence analysis in bacteria with probiotic properties. Moreover, this study follows existing issues about the importance and presence of ARGs in these bacteria the dangers of which may affect human health in the years to come. In the present study, 126 complete probiotic bacterial genomes were collected and analysed for ARGs. The results of the study shows there are various antibiotic resistant genes of in these bacteria some of which can be transmitted to other bacteria. We propose microorganisms be applied as a probiotic element in various types of products, antibiogram be conducted for a large number of antibiotics and analysis of complete genome sequence for ARGs prediction.

Metagenomic analysis of effects of oxytetracycline and copper on antibiotic resistance genes and associated pathogenic hosts in swine manure compost

2020 ◽  
Author(s):  
Honghong Guo ◽  
jie gu ◽  
Xiaojuan Wang ◽  
Zilin Song ◽  
Xun Qian ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Pathogenic Bacteria ◽  
Swine Manure ◽  
Antibiotic Resistance Genes ◽  
Feed Additives ◽  
Poultry Feed ◽  
Risk Scores ◽  
Composting Process ◽  
Positive Effects

Abstract Background: The proliferation of antibiotic resistance genes (ARGs) in compost and their horizontal transfer to human pathogenic bacteria (HPB) may lead to the failure of human antibiotics. However, the antibiotic resistome in compost has not been comprehensively characterized. This study used a metagenomic approach to obtain new insights into the effects of oxytetracycline (OTC) and copper (Cu) on the antibiotic resistome during swine manure composting and the risks posed to human health. Results: The results showed that composting reduced the abundances and diversity of ARGs and HPB in swine manure. In total, 289 ARG subtypes and 19 ARG types were detected in the samples with abundances ranging from 1.08 ´ 10 –1 to 9.39 ´ 10 –1 copies/16S rRNA, which mainly encoded tetracycline, aminoglycoside, and macrolide–lincosamide–streptogramin (MLS) resistance genes. The application of OTC and Cu, especially the combined application, exacerbated the compost resistome risk scores and specific ARG subtypes responded differently. Tetracycline, multidrug, and MLS resistance genes mainly affected resistance profiles of HPB throughout the composting process. HPB and intI1 had significant positive effects on determining the ARG profiles during the composting process, and the co-selective effect of heavy metals may increase the abundances of ARGs via strong positive effects on intI1 . In addition, the effect of mobile genetic elements on the horizontal gene transfer of ARGs should not be ignored. Conclusions: This study of the antibiotic resistome in compost indicates the need for effective regulation of the misuse of livestock and poultry feed additives in order to minimize the spread of the antibiotic resistome in agro-ecosystems and decrease the potential risk to public health. Keywords: Antibiotic resistome; Composting; Metagenome; Pathogenic host; Swine manure

Sign in / Sign up

Export Citation Format

Share Document