1
|
Cabezón E, Valenzuela-Gómez F, Arechaga I. Primary architecture and energy requirements of Type III and Type IV secretion systems. Front Cell Infect Microbiol 2023; 13:1255852. [PMID: 38089815 PMCID: PMC10711112 DOI: 10.3389/fcimb.2023.1255852] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2023] [Accepted: 11/08/2023] [Indexed: 12/18/2023] Open
Abstract
Many pathogens use Type III and Type IV protein secretion systems to secrete virulence factors from the bacterial cytosol into host cells. These systems operate through a one-step mechanism. The secreted substrates (protein or nucleo-protein complexes in the case of Type IV conjugative systems) are guided to the base of the secretion channel, where they are directly delivered into the host cell in an ATP-dependent unfolded state. Despite the numerous disparities between these secretion systems, here we have focused on the structural and functional similarities between both systems. In particular, on the structural similarity shared by one of the main ATPases (EscN and VirD4 in Type III and Type IV secretion systems, respectively). Interestingly, these ATPases also exhibit a structural resemblance to F1-ATPases, which suggests a common mechanism for substrate secretion. The correlation between structure and function of essential components in both systems can provide significant insights into the molecular mechanisms involved. This approach is of great interest in the pursuit of identifying inhibitors that can effectively target these systems.
Collapse
Affiliation(s)
- Elena Cabezón
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria- CSIC, Santander, Spain
| | | | - Ignacio Arechaga
- Departamento de Biología Molecular and Instituto de Biomedicina y Biotecnología de Cantabria (IBBTEC), Universidad de Cantabria- CSIC, Santander, Spain
| |
Collapse
|
2
|
Arbé-Carton K, Rey-Sogo A, Santos-Fernández N, Altube O, Garbisu C, Arana L, Alkorta I. Development of a high-throughput platform to measure plasmid transfer frequency. Front Cell Infect Microbiol 2023; 13:1269732. [PMID: 37886666 PMCID: PMC10598849 DOI: 10.3389/fcimb.2023.1269732] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 09/25/2023] [Indexed: 10/28/2023] Open
Abstract
Antibiotic resistance represents one of the greatest threats to global health. The spread of antibiotic resistance genes among bacteria occurs mostly through horizontal gene transfer via conjugation mediated by plasmids. This process implies a direct contact between a donor and a recipient bacterium which acquires the antibiotic resistance genes encoded by the plasmid and, concomitantly, the capacity to transfer the acquired plasmid to a new recipient. Classical assays for the measurement of plasmid transfer frequency (i.e., conjugation frequency) are often characterized by a high variability and, hence, they require many biological and technical replicates to reduce such variability and the accompanying uncertainty. In addition, classical conjugation assays are commonly tedious and time-consuming because they typically involve counting colonies on a large number of plates for the quantification of donors, recipients, and transconjugants (i.e., the bacteria that have received the genetic material by conjugation). Due to the magnitude of the antibiotic resistance problem, it is critical to develop reliable and rapid methods for the quantification of plasmid transfer frequency that allow the simultaneous analysis of many samples. Here, we present the development of a high-throughput, reliable, quick, easy, and cost-effective method to simultaneously accomplish and measure multiple conjugation events in 96-well plates, in which the quantification of donors, recipients, and transconjugants is estimated from the time required to reach a specific threshold value (OD600 value) in the bacterial growth curves. Our method successfully discriminates different plasmid transfer frequencies, yielding results that are equivalent to those obtained by a classical conjugation assay.
Collapse
Affiliation(s)
- Kepa Arbé-Carton
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Ana Rey-Sogo
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Nagore Santos-Fernández
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Oihane Altube
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| | - Carlos Garbisu
- Department of Conservation of Natural Resources, NEIKER-Basque Institute for Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Derio, Spain
| | - Lide Arana
- Department of Applied Chemistry, University of the Basque Country (UPV/EHU), Donostia, Spain
| | - Itziar Alkorta
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), Bilbao, Spain
| |
Collapse
|
3
|
Beltrán de Heredia I, Garbisu C, Alkorta I, Urra J, González-Gaya B, Ruiz-Romera E. Spatio-seasonal patterns of the impact of wastewater treatment plant effluents on antibiotic resistance in river sediments. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2023; 319:120883. [PMID: 36572269 DOI: 10.1016/j.envpol.2022.120883] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/26/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 06/17/2023]
Abstract
There is a growing concern about the risk of antibiotic resistance emergence and dissemination in the environment. Here, we evaluated the spatio-seasonal patterns of the impact of wastewater treatment plant (WWTP) effluents on antibiotic resistance in river sediments. To this purpose, sediment samples were collected in three river basins affected by WWTP effluents in wet (high-water period) and dry (low-water period) hydrological conditions at three locations: (i) upstream the WWTPs; (ii) WWTP effluent discharge points (effluent outfall); and (iii) downstream the WWTPs (500 m downriver from the effluent outfall). The absolute and relative abundances of 9 antibiotic resistance genes (ARGs), 3 mobile genetic element (MGE) genes, and 4 metal resistance genes (MRGs) were quantified in sediment samples, as well as a variety of physicochemical parameters, metal contents, and antibiotic concentrations in both sediment and water samples. In sediments, significantly higher relative abundances of most genes were observed in downstream vs. upstream sampling points. Seasonal changes (higher values in low-water vs. high-water period) were observed for both ARG absolute and relative abundances in sediment samples. Chemical data revealed the contribution of effluents from WWTPs as a source of antibiotic and metal contamination in river ecosystems. The observed positive correlations between ARG and MGE genes relative abundances point out to the role of horizontal gene transfer in antibiotic resistance dissemination. Monitoring plans that take into consideration spatio-temporal patterns must be implemented to properly assess the environmental fate of WWTP-related emerging contaminants in river ecosystems.
Collapse
Affiliation(s)
- Irene Beltrán de Heredia
- Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo 1, 48013, Bilbao, Spain.
| | - Carlos Garbisu
- Department of Conservation of Natural Resources, NEIKER-Basque Institute of Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Bizkaia Science and Technology Park, P812, 48160, Derio, Spain
| | - Itziar Alkorta
- Department of Biochemistry and Molecular Biology, University of the Basque Country (UPV/EHU), P.O. Box 644, 48080, Bilbao, Spain
| | - Julen Urra
- Department of Conservation of Natural Resources, NEIKER-Basque Institute of Agricultural Research and Development, Basque Research and Technology Alliance (BRTA), Bizkaia Science and Technology Park, P812, 48160, Derio, Spain
| | - Belén González-Gaya
- Department of Analytical Chemistry, University of the Basque Country (UPV/EHU), Campus of Leioa, 48940, Leioa, Spain; Research Centre for Experimental Marine Biology and Biotechnology (PIE), University of the Basque Country (UPV/EHU), Areatza Pasealekua 47, 48620, Plentzia, Spain
| | - Estilita Ruiz-Romera
- Department of Chemical and Environmental Engineering, University of the Basque Country (UPV/EHU), Plaza Ingeniero Torres Quevedo 1, 48013, Bilbao, Spain
| |
Collapse
|
4
|
Tang T, Chen Y, Du Y, Yao B, Liu M. Effects of functional modules and bacterial clusters response on transmission performance of antibiotic resistance genes under antibiotic stress during anaerobic digestion of livestock wastewater. JOURNAL OF HAZARDOUS MATERIALS 2023; 441:129870. [PMID: 36063716 DOI: 10.1016/j.jhazmat.2022.129870] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/06/2022] [Accepted: 08/26/2022] [Indexed: 06/15/2023]
Abstract
The formation and transmission of antibiotic resistance genes (ARGs) have attracted increasing attention. It is unclear whether the internal mechanisms by which antibiotics affect horizontal gene transfer (HGT) of ARGs during anaerobic digestion (AD) were influenced by dose and type. We investigated the effects of two major antibiotics (oxytetracycline, OTC, and sulfamethoxazole, SMX) on ARGs during AD according to antibiotic concentration in livestock wastewater influent. The low-dose antibiotic (0.5 mg/L) increased ROS and SOS responses, promoting the formation of ARGs. Meanwhile, low-dose antibiotics could also promote the spread of ARGs by promoting pili, communication responses, and the type IV secretion system (T4SS). However, different types and doses of antibiotics would lead to changes in the above functional modules and then affect the enrichment of ARGs. With the increasing dose of SMX, the advantages of pili and communication responses would gradually change. In the OTC system, low-dose has the strongest promoting ability in both pili and communication responses. Similarly, an increase in the dose of SMX would change T4SS from facilitation to inhibition, while OTC completely inhibits T4SS. Microbial and network analysis also revealed that low-dose antibiotics were more favorable for the growth of host bacteria.
Collapse
Affiliation(s)
- Taotao Tang
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China
| | - Ying Chen
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China
| | - Ye Du
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China
| | - Bing Yao
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China
| | - Min Liu
- College of Architecture and Environment, Sichuan University, Chengdu 610065, PR China.
| |
Collapse
|
5
|
Tang B, Wang C, Sun D, Lin H, Ma J, Guo H, Yang H, Li X. In Silico Characterization of blaNDM-Harboring Conjugative Plasmids in Acinetobacter Species. Microbiol Spectr 2022; 10:e0210222. [PMID: 36301090 PMCID: PMC9769834 DOI: 10.1128/spectrum.02102-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 09/28/2022] [Indexed: 01/06/2023] Open
Abstract
New Delhi metallo-β-lactamase (NDM)-producing clinical strains in Acinetobacter spp. have been recently reported in many countries and have received considerable attention. The vast majority of blaNDM cases occur on conjugative plasmids, which play a vital role in disseminating blaNDM. To characterize the conjugative plasmids bearing blaNDM genes in Acinetobacter spp., we analyzed the variants of blaNDM, conjugative transfer regions, genetic contexts of blaNDM, and the phylogenetic pattern of the 62 predicted blaNDM-positive plasmids, which were selected from 1,191 plasmids of Acinetobacter species from GenBank. We identified 30 conjugative plasmids from the 62 blaNDM-harboring plasmids in Acinetobacter species, with the oriT sites similar to plasmid pNDM-YR7 in our study, genes coding for relaxases of the MOBQ family, genes encoding type IV coupling proteins (T4CPs) of the TrwB/TraD subfamily, and VirB-like type IV secretion system (T4SS) gene clusters. The genome sizes of all 30 pNDM-YR7-like plasmids ranged from 39.36 kb to 49.65 kb, with a median size of 44.56 kb. The most common species of Acinetobacter containing the blaNDM-positive conjugative plasmids was A. baumannii, followed by Acinetobacter lwoffii and Acinetobacter indicus. Notably, pNDM-YR7 is the first report on a blaNDM-positive conjugative plasmid in Acinetobacter junii. Moreover, all 30 blaNDM-positive conjugative plasmids in Acinetobacter species were found to contain genetic contexts with the structure ISAba14-aph(3')-VI-ISAba125-blaNDM-ble. Our findings provide important insights into the phylogeny and evolution of blaNDM-positive plasmids of Acinetobacter species and further address their role in acquiring and spreading blaNDM genes in Acinetobacter species. IMPORTANCE Conjugative plasmids harboring the blaNDM gene play a vital role in disseminating carbapenem resistance. In this study, we first report a conjugative plasmid, pNDM-YR7, in Acinetobacter junii. Based on the genomic characteristics of the blaNDM-positive pNDM-YR7, we performed in silico typing and comparative analysis of blaNDM-positive plasmids using the 1,191 plasmids of Acinetobacter species available in the NCBI RefSeq database. We analyzed the characteristics of blaNDM-positive plasmids, including the variants of blaNDM, genetic features associated with blaNDM, conjugative transfer regions, and the phylogenetic pattern of the blaNDM-positive plasmids. All 30 blaNDM-positive conjugative plasmids were found to contain an ISAba14-aph(3')-VI-ISAba125-blaNDM-ble region. This study provides novel insights into the phylogeny and evolution of blaNDM-harboring conjugative plasmids and contributes to the repertoire of knowledge surrounding blaNDM-positive plasmids in the genus Acinetobacter.
Collapse
Affiliation(s)
- Biao Tang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products & Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Chenyu Wang
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Dongchang Sun
- College of Biotechnology and Bioengineering, Zhejiang University of Technology, Hangzhou, China
| | - Hui Lin
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products & Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Jiangang Ma
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products & Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Hengzhao Guo
- Department of Radiation Oncology, Zhuhai People’s Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai, Guangdong, China
| | - Hua Yang
- State Key Laboratory for Managing Biotic and Chemical Threats to the Quality and Safety of Agro-products & Institute of Agro-product Safety and Nutrition, Zhejiang Academy of Agricultural Sciences, Hangzhou, Zhejiang, China
| | - Xiaobin Li
- Zhuhai Precision Medical Center, Zhuhai People's Hospital (Zhuhai Hospital affiliated with Jinan University), Zhuhai, Guangdong, China
| |
Collapse
|
6
|
Yu Z, Zhang Z, Shi L, Hua S, Luan T, Lin Q, Zheng Z, Feng X, Liu M, Li X. In silico characterization of IncX3 plasmids carrying blaOXA-181 in Enterobacterales. Front Cell Infect Microbiol 2022; 12:988236. [PMID: 36159637 PMCID: PMC9492964 DOI: 10.3389/fcimb.2022.988236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 08/23/2022] [Indexed: 12/03/2022] Open
Abstract
Carbapenem-resistant Enterobacterales poses a global urgent antibiotic resistance threat because of its ability to transfer carbapenemase genes to other bacteria via horizontal gene transfer mediated by mobile genetic elements such as plasmids. Oxacillinase-181 (OXA-181) is one of the most common OXA-48-like carbapenemases, and OXA-181-producing Enterobacterales has been reported in many countries worldwide. However, systematic research concerning the overall picture of plasmids harboring blaOXA-181 in Enterobacterales is currently scarce. In this study, we aimed to determine the phylogeny and evolution of blaOXA-181-positive (gene encoding OXA-181) plasmids. To characterize the plasmids harboring blaOXA-181 in Enterobacterales, we identified 81 blaOXA-181-positive plasmids from 35,150 bacterial plasmids downloaded from the NCBI RefSeq database. Our results indicated that diverse plasmid types harbored blaOXA-181 but was predominantly carried by IncX3-type plasmids. We systematically compared the host strains, plasmid types, conjugative transfer regions, and genetic contexts of blaOXA-181 among the 66 blaOXA-181-positive IncX3 plasmids. We found that IncX3 plasmids harboring blaOXA-181 were mostly ColKP3-IncX3 hybrid plasmids with a length of 51 kb each and were mainly distributed in Escherichia coli and Klebsiella pneumoniae. Most of the IncX3 plasmids harboring blaOXA-181 were human origin. Almost all the blaOXA-181-positive IncX3 plasmids were found to carry genes coding for relaxases of the MOBP family and VirB-like type IV secretion system (T4SS) gene clusters, and all the 66 IncX3 plasmids were found to carry the genes encoding type IV coupling proteins (T4CPs) of the VirD4/TraG subfamily. Most IncX3 plasmids harbored both blaOXA-181 and qnrS1 in their genomes, and the two antibiotic resistance genes were found to a composite transposon bracketed by two copies of insertion sequence IS26 in the same orientation. Our findings provide important insights into the phylogeny and evolution of blaOXA-181-positive IncX3 plasmids and further address their role in acquiring and spreading blaOXA-181 genes in Enterobacterales.
Collapse
Affiliation(s)
- Zhijian Yu
- Department of Otolaryngology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Zhengrong Zhang
- Department of Urology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Lile Shi
- Department of Cardiology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Shengni Hua
- Department of Radiation Oncology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Ting Luan
- Community Health Service Center of Xinkou Town, Tianjin, China
| | - Qiuping Lin
- Zhuhai Precision Medical Center, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Zhixiong Zheng
- Zhuhai Precision Medical Center, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
| | - Xiaosan Feng
- Department of Neonatology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
- *Correspondence: Xiaobin Li, ; Mubiao Liu, ; Xiaosan Feng,
| | - Mubiao Liu
- Department of Obstetrics and Gynecology, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
- *Correspondence: Xiaobin Li, ; Mubiao Liu, ; Xiaosan Feng,
| | - Xiaobin Li
- Zhuhai Precision Medical Center, Zhuhai People’s Hospital, Zhuhai Hospital Affiliated with Jinan University, Zhuhai, China
- *Correspondence: Xiaobin Li, ; Mubiao Liu, ; Xiaosan Feng,
| |
Collapse
|
7
|
Al Mamun AAM, Kissoon K, Kishida K, Shropshire WC, Hanson B, Christie PJ. IncFV plasmid pED208: Sequence analysis and evidence for translocation of maintenance/leading region proteins through diverse type IV secretion systems. Plasmid 2022; 123-124:102652. [PMID: 36228885 PMCID: PMC10018792 DOI: 10.1016/j.plasmid.2022.102652] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 10/02/2022] [Accepted: 10/04/2022] [Indexed: 12/04/2022]
Abstract
Two phylogenetically distantly-related IncF plasmids, F and pED208, serve as important models for mechanistic and structural studies of F-like type IV secretion systems (T4SSFs) and F pili. Here, we present the pED208 sequence and compare it to F and pUMNF18, the closest match to pED208 in the NCBI database. As expected, gene content of the three cargo regions varies extensively, although the maintenance/leading regions (MLRs) and transfer (Tra) regions also carry novel genes or motifs with predicted modulatory effects on plasmid stability, dissemination and host range. By use of a Cre recombinase assay for translocation (CRAfT), we recently reported that pED208-carrying donors translocate several products of the MLR (ParA, ParB1, ParB2, SSB, PsiB, PsiA) intercellularly through the T4SSF. Here, we extend these findings by reporting that pED208-carrying donors translocate 10 additional MLR proteins during conjugation. In contrast, two F plasmid-encoded toxin components of toxin-antitoxin (TA) modules, CcdB and SrnB, were not translocated at detectable levels through the T4SSF. Remarkably, most or all of the pED208-encoded MLR proteins and CcdB and SrnB were translocated through heterologous T4SSs encoded by IncN and IncP plasmids pKM101 and RP4, respectively. Together, our sequence analyses underscore the genomic diversity of the F plasmid superfamily, and our experimental data demonstrate the promiscuous nature of conjugation machines for protein translocation. Our findings raise intriguing questions about the nature of T4SS translocation signals and of the biological and evolutionary consequences of conjugative protein transfer.
Collapse
Affiliation(s)
- Abu Amar M Al Mamun
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Fannin St, Houston, TX 77030, United States of America.
| | - Kimberly Kissoon
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Fannin St, Houston, TX 77030, United States of America
| | - Kouhei Kishida
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Fannin St, Houston, TX 77030, United States of America
| | - William C Shropshire
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA; Center for Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, TX, USA
| | - Blake Hanson
- Center for Antimicrobial Resistance and Microbial Genomics, University of Texas Health Science Center, McGovern School of Medicine, Houston, TX, USA; Center for Infectious Diseases, University of Texas Health Science Center, School of Public Health, Houston, TX, USA
| | - Peter J Christie
- Department of Microbiology and Molecular Genetics, University of Texas Health Science Center, McGovern School of Medicine, Fannin St, Houston, TX 77030, United States of America.
| |
Collapse
|
8
|
Zhang L, Sun J, Zhang Z, Peng Z, Dai X, Ni BJ. Polyethylene terephthalate microplastic fibers increase the release of extracellular antibiotic resistance genes during sewage sludge anaerobic digestion. WATER RESEARCH 2022; 217:118426. [PMID: 35427830 DOI: 10.1016/j.watres.2022.118426] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Revised: 04/04/2022] [Accepted: 04/05/2022] [Indexed: 06/14/2023]
Abstract
Microplastic fibers (MFs), as the most frequently detected microplastic shape in sewage sludge, have posed emerging concern for sludge treatment and disposal. However, the effect of MFs on antibiotic resistance genes (ARGs), especially extracellular ARGs (eARGs) during sludge treatment remains far from explicit. Therefore, this study investigated the potential impact of MFs on eARGs during sludge anaerobic digestion (AD), a commonly used sludge treatment method, through long-term operation. The qPCR results showed that both absolute and relative abundances of eARGs increased with the MFs exposure during sludge AD. The average absolute and relative abundances of eight tested eARGs in the AD reactor with the highest MFs dosage (170 items/gTS) were 1.70 and 2.15 times higher than those in the control AD reactor. The metagenomics results further comfirmed the increase of eARGs abundance during sludge anaerobic digestion after MFs exposure and the enhancement did not show significant selectivity. The identification of the potential hosts of eARGs suggested the host numbers of eARGs also increased with MFs exposure, which may suggest enhanced horizonal transformation as a result of increased eARGs. Further exploring the mechansims showed that the genes involved in type IV secretion system was upregulated after MFs exposure, suggesting the active release of eARGs was enhanced with MFs exposure. In contrast, the MFs may not affect the passive release of eARGs as its impact on cell membrance damage was insignificant. The enhanced eARGs in sludge AD process may further accelerate the transport of ARGs in environment, which should be considered during sludge treatment and disposal.
Collapse
Affiliation(s)
- Lu Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Jing Sun
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China; Anhui Provincial Key Laboratory of Environmental Pollution Control and Resource Reuse, Hefei 230000, China.
| | - Zisha Zhang
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Zitong Peng
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China
| | - Xiaohu Dai
- State Key Laboratory of Pollution Control and Resource Reuse, Key Laboratory of Yangtze River Water Environment, College of Environmental Science and Engineering, Tongji University, Shanghai 200092, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai 200092, China
| | - Bing-Jie Ni
- Centre for Technology in Water and Wastewater (CTWW), School of Civil and Environmental Engineering, University of Technology Sydney (UTS), Sydney, NSW 2007, Australia
| |
Collapse
|
9
|
Biology and engineering of integrative and conjugative elements: Construction and analyses of hybrid ICEs reveal element functions that affect species-specific efficiencies. PLoS Genet 2022; 18:e1009998. [PMID: 35584135 PMCID: PMC9154091 DOI: 10.1371/journal.pgen.1009998] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 05/31/2022] [Accepted: 04/04/2022] [Indexed: 11/19/2022] Open
Abstract
Integrative and conjugative elements (ICEs) are mobile genetic elements that reside in a bacterial host chromosome and are prominent drivers of bacterial evolution. They are also powerful tools for genetic analyses and engineering. Transfer of an ICE to a new host involves many steps, including excision from the chromosome, DNA processing and replication, transfer across the envelope of the donor and recipient, processing of the DNA, and eventual integration into the chromosome of the new host (now a stable transconjugant). Interactions between an ICE and its host throughout the life cycle likely influence the efficiencies of acquisition by new hosts. Here, we investigated how different functional modules of two ICEs, Tn916 and ICEBs1, affect the transfer efficiencies into different host bacteria. We constructed hybrid elements that utilize the high-efficiency regulatory and excision modules of ICEBs1 and the conjugation genes of Tn916. These elements produced more transconjugants than Tn916, likely due to an increase in the number of cells expressing element genes and a corresponding increase in excision. We also found that several Tn916 and ICEBs1 components can substitute for one another. Using B. subtilis donors and three Enterococcus species as recipients, we found that different hybrid elements were more readily acquired by some species than others, demonstrating species-specific interactions in steps of the ICE life cycle. This work demonstrates that hybrid elements utilizing the efficient regulatory functions of ICEBs1 can be built to enable efficient transfer into and engineering of a variety of other species. Horizontal gene transfer helps drive microbial evolution, enabling bacteria to rapidly acquire new genes and traits. Integrative and conjugative elements (ICEs) are mobile genetic elements that reside in a bacterial host chromosome and are prominent drivers of horizontal gene transfer. They are also powerful tools for genetic analyses and engineering. Some ICEs carry genes that confer obvious properties to host bacteria, including antibiotic resistances, symbiosis, and pathogenesis. When activated, an ICE-encoded machine is made that can transfer the element to other cells, where it then integrates into the chromosome of the new host. Specific ICEs transfer more effectively into some bacterial species compared to others, yet little is known about the determinants of the efficiencies and specificity of acquisition by different bacterial species. We made and utilized hybrid ICEs, composed of parts of two different elements, to investigate determinants of transfer efficiencies. Our findings demonstrate that there are species-specific interactions that help determine efficiencies of stable acquisition, and that this explains, in part, the efficiencies of different ICEs. These hybrid elements are also useful in genetic engineering and synthetic biology to move genes and pathways into different bacterial species with greater efficiencies than can be achieved with naturally occurring ICEs.
Collapse
|
10
|
Costa TRD, Harb L, Khara P, Zeng L, Hu B, Christie PJ. Type IV secretion systems: Advances in structure, function, and activation. Mol Microbiol 2021; 115:436-452. [PMID: 33326642 DOI: 10.1111/mmi.14670] [Citation(s) in RCA: 112] [Impact Index Per Article: 37.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/12/2020] [Accepted: 12/13/2020] [Indexed: 12/14/2022]
Abstract
Bacterial type IV secretion systems (T4SSs) are a functionally diverse translocation superfamily. They consist mainly of two large subfamilies: (i) conjugation systems that mediate interbacterial DNA transfer and (ii) effector translocators that deliver effector macromolecules into prokaryotic or eukaryotic cells. A few other T4SSs export DNA or proteins to the milieu, or import exogenous DNA. The T4SSs are defined by 6 or 12 conserved "core" subunits that respectively elaborate "minimized" systems in Gram-positive or -negative bacteria. However, many "expanded" T4SSs are built from "core" subunits plus numerous others that are system-specific, which presumptively broadens functional capabilities. Recently, there has been exciting progress in defining T4SS assembly pathways and architectures using a combination of fluorescence and cryoelectron microscopy. This review will highlight advances in our knowledge of structure-function relationships for model Gram-negative bacterial T4SSs, including "minimized" systems resembling the Agrobacterium tumefaciens VirB/VirD4 T4SS and "expanded" systems represented by the Helicobacter pylori Cag, Legionella pneumophila Dot/Icm, and F plasmid-encoded Tra T4SSs. Detailed studies of these model systems are generating new insights, some at atomic resolution, to long-standing questions concerning mechanisms of substrate recruitment, T4SS channel architecture, conjugative pilus assembly, and machine adaptations contributing to T4SS functional versatility.
Collapse
Affiliation(s)
- Tiago R D Costa
- MRC Centre for Molecular Bacteriology and Infection, Department of Life Sciences, Imperial College London, London, UK
| | - Laith Harb
- Department of Biochemistry and Biophysics and Center for Phage Technology, Texas A&M University, College Station, TX, USA
| | - Pratick Khara
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX, USA
| | - Lanying Zeng
- Department of Biochemistry and Biophysics and Center for Phage Technology, Texas A&M University, College Station, TX, USA
| | - Bo Hu
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX, USA
| | - Peter J Christie
- Department of Microbiology and Molecular Genetics, McGovern Medical School at UTHealth, Houston, TX, USA
| |
Collapse
|