1
|
Hu X, Yu C, Li X, Zou J, Du Y, Paterson DM. Biomineralization of heavy metals based on urea transport and hydrolysis within a new bacterial isolate, B. intermedia TSBOI. JOURNAL OF HAZARDOUS MATERIALS 2024; 469:134049. [PMID: 38522207 DOI: 10.1016/j.jhazmat.2024.134049] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2023] [Revised: 03/12/2024] [Accepted: 03/13/2024] [Indexed: 03/26/2024]
Abstract
A newly isolated ureolytic bacteria, Brucella intermedia TSBOI, exhibited microbially induced calcite precipitation (MICP) which is a promising technique for the remediation of heavy metals in polluted environments. Brucella intermedia TSBOI achieved 90-100% removal of 1 mmol/L Cu2+/Pb2+/Zn2+ within 72 h. A distinctive feature lies in B. intermedia TSBOI's capacity for the transport and hydrolysis of urea, considered to be critical for its strong urease activity. This study explored the mechanisms of this capacity at the genetic, molecular and protein levels through complete genome sequencing, molecular docking and enzymatic reaction kinetics. The results revealed that, for urea hydrolysis, B. intermedia TSBOI exhibited a comprehensive urease gene cluster, with the key gene ureC demonstrating an absolute expression level approximating to 4 × 104 copies/RNA ng under optimal conditions. Results also confirmed the strong spontaneous, energy-independent binding ability of it's urease to urea, with the lowest Gibbs free energy binding site linking to the three amino acids, alanine, asparagine and serine. The urea transport gene yut presented and expressed, with the absolute expression enhanced in response to increasing urea concentrations. The significant positive correlation between ureC/yut expression levels and urease activity provided a theoretical basis for B. intermedia TSBOI's heavy metal bioremediation potential. ENVIRONMENTAL IMPLICATION: Heavy metals (Cu, Pb and Zn) were studied in this study. Heavy metals are hazardous due to their toxicity, persistence, and ability to bioaccumulate in living organisms. They can cause severe health issues, harm ecosystems, and contaminate air, water, and soil. A novel ureolytic bacteria, Brucella intermedia TSBOI, exhibited microbially induced carbonate precipitation capability was isolated which removed 90-100% of 1 mmol/L Cu2+/Pb2+/Zn2+ within 72 h. Its advantages in urea hydrolysis and transport facilitate the remediation of actual heavy metal contaminated environments.
Collapse
Affiliation(s)
- Xuesong Hu
- School of Chemical & Environmental Engineering, China University of Mining and Technology (Beijing), 100083 Beijing, China
| | - Caihong Yu
- School of Chemical & Environmental Engineering, China University of Mining and Technology (Beijing), 100083 Beijing, China.
| | - Xianhong Li
- School of Chemical & Environmental Engineering, China University of Mining and Technology (Beijing), 100083 Beijing, China
| | - Jiacheng Zou
- School of Chemical & Environmental Engineering, China University of Mining and Technology (Beijing), 100083 Beijing, China
| | - Yanbin Du
- School of Chemical & Environmental Engineering, China University of Mining and Technology (Beijing), 100083 Beijing, China
| | - David M Paterson
- Scottish Oceans Institute, School of Biology, University of St Andrews, East Sands, St. Andrews, Fife KY16 8LB, UK
| |
Collapse
|
2
|
Yu F, Luo W, Xie W, Li Y, Liu Y, Ye X, Peng T, Wang H, Huang T, Hu Z. The effects of long-term hexabromocyclododecanes contamination on microbial communities in the microcosms. CHEMOSPHERE 2023; 325:138412. [PMID: 36925001 DOI: 10.1016/j.chemosphere.2023.138412] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 01/21/2023] [Accepted: 03/13/2023] [Indexed: 06/18/2023]
Abstract
The adaptation of microbial community to the long-term contamination of hexabromocyclododecanes (HBCDs) has not been well studied. Our previous study found that the HBCDs contamination in the microcosms constructed of sediments from two different mangrove forests in 8 months resulted in serious acidification (pH2-3). This study reanalyzed previous sequencing data and compared them with data after 20 months to investigate the adaptive properties of microbial communities in the stress of HBCDs and acidification. It hypothesized that the reassembly was based on the fitness of taxa. The results indicated that eukaryotes and fungi might have better adaptive capacity to these deteriorated habitats. Eukaryotic taxa Eufallia and Syncystis, and fungal taxa Wickerhamomyces were only detected after 20 months of contamination. Moreover, eukaryotic taxa Caloneis and Nitzschia, and fungal taxa Talaromyces were dominant in most of microbial communities (14.467-95.941%). The functional compositions were sediment-dependent and more divergent than community reassemblies. Network and co-occurrence analysis suggested that acidophiles such as Acidisoma and Acidiphilium were gaining more positive relations in the long-term stress. The acidophilic taxa and genes involved in resistance to the acidification and toxicity of HBCDs were enriched, for example, bacteria Acidisoma and Acidiphilium, archaea Thermogymnomonas, and eukaryotes Nitzschia, and genes kdpC, odc1, polA, gst, and sod-2. These genes involved in oxidative stress response, energy metabolism, DNA damage repair, potassium transportation, and decarboxylation. It suggested that the microbial communities might cope with the stress from HBCDs and acidification via multiple pathways. The present research shed light on the evolution of microbial communities under the long-term stress of HBCDs contamination and acidification.
Collapse
Affiliation(s)
- Fei Yu
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Wenqi Luo
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Wei Xie
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Yuyang Li
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Yongjin Liu
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Xueying Ye
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Tao Peng
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Hui Wang
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China
| | - Tongwang Huang
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China.
| | - Zhong Hu
- Department of Biology, College of Science, Shantou University, Shantou, Guangdong Province, China; Southern Marine Science and Engineering Guangdong Laboratory (Guangzhou), Guangzhou, Guangdong Province, China.
| |
Collapse
|
3
|
Lin WF, Hu RY, Chang HY, Lin FY, Kuo CH, Su LH, Peng HL. The role of urease in the acid stress response and fimbriae expression in Klebsiella pneumoniae CG43. JOURNAL OF MICROBIOLOGY, IMMUNOLOGY, AND INFECTION = WEI MIAN YU GAN RAN ZA ZHI 2022; 55:620-633. [PMID: 35367140 DOI: 10.1016/j.jmii.2022.02.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 01/26/2022] [Accepted: 02/07/2022] [Indexed: 06/14/2023]
Abstract
BACKGROUND/PURPOSE Two urease operons were identified in Klebsiella pneumoniae CG43, ure-1 and ure-2. This study investigates whether a differential regulation of the expression of ure-1 and ure-2 exists and how urease activity influences the acid stress response and expression of type 1 and type 3 fimbriae. METHODS The ureA1 and ureA2 gene specific deletion mutants were constructed. Promoter activity was assessed using a LacZ reporter system. The sensitivity to acid stress was determined by assessing the survival after pH 2.5 treatment. The influence on type 1 and type 3 fimbriae expression was assessed using western blotting and mannose-sensitive yeast agglutination and biofilm formation assay, respectively. RESULTS Bacterial growth analysis in mM9-U or modified Stuart broth revealed that ure-1 was the principal urease system, and ure-2 had a negative effect on ure-1 activity. Deletion of the fur or nac gene had no apparent effect on the activity of Pure1, Pure2-1, and Pure2-2. The Pure2-2 activity was enhanced by deletion of the hns gene. ureA1 deletion increased acid stress sensitivity, whereas the deleting effect of ureA2 was notable without hns. Deletion of ureA1 or ureA2 significantly induced the expression of type 1 fimbriae but decreased MrkA production and biofilm formation. CONCLUSION ure-1 is the primary expression system in K. pneumoniae CG43, while ure-2 is active in the absence of hns. Impairment of urease activity increases the sensitivity to acid stress, and the accumulation of urea induces the expression of type 1 fimbriae but represses type 3 fimbriae expression.
Collapse
Affiliation(s)
- Wei-Feng Lin
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan
| | - Rong-Yu Hu
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan
| | - Hwan-You Chang
- Institute of Molecular Medicine, National Tsing Hua University, Hsin Chu, Taiwan
| | - Fang-Yu Lin
- Institute of Molecular Medicine, National Tsing Hua University, Hsin Chu, Taiwan
| | - Chih-Hao Kuo
- Department of Biological Science and Technology, School of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan
| | - Li-Hsin Su
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan
| | - Hwei-Ling Peng
- Institute of Molecular Medicine and Bioengineering, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan; Department of Biological Science and Technology, School of Biological Science and Technology, National Yang Ming Chiao Tung University, Hsin Chu, Taiwan.
| |
Collapse
|
4
|
Ezeobiora CE, Igbokwe NH, Amin DH, Enwuru NV, Okpalanwa CF, Mendie UE. Uncovering the biodiversity and biosynthetic potentials of rare actinomycetes. FUTURE JOURNAL OF PHARMACEUTICAL SCIENCES 2022. [DOI: 10.1186/s43094-022-00410-y] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Abstract
Background
Antibiotic resistance is on the rise, and new antibiotic research has slowed in recent years, necessitating the discovery of possibly novel microbial resources capable of producing bioactive compounds. Microbial infections are gaining resistance to existing antibiotics, emphasizing the need for novel medicinal molecules to be discovered as soon as possible. Because the possibilities of isolating undiscovered actinomycetes strains have decreased, the quest for novel products has shifted to rare actinomycetes genera from regular environments or the identification of new species identified in unusual habitats.
Main body of the abstract
The non-streptomyces actinobacteria are known as rare actinomycetes that are extremely difficult to cultivate. Rare actinomycetes are known to produce a variety of secondary metabolites with varying medicinal value. In this review, we reported the diversity of rare actinomycetes in several habitat including soil, plants, aquatic environment, caves, insects and extreme environments. We also reported some isolation methods to easily recover rare Actinobacteria from various sources guided with some procedures to identify the rare Actinobacteria isolates. Finally, we reported the biosynthetic potential of rare actinomycetes and its role in the production of unique secondary metabolites that could be used in medicine, agriculture, and industry. These microbial resources will be of interest to humanity, as antibiotics, insecticides, anticancer, antioxidants, to mention but a few.
Short conclusion
Rare actinomycetes are increasingly being investigated for new medicinal compounds that could help to address existing human health challenges such as newly emerging infectious illnesses, antibiotic resistance, and metabolic disorders. The bioactive secondary metabolites from uncommon actinomycetes are the subject of this review, which focuses on their diversity in different habitats, isolation, identification and biosynthetic potentials.
Collapse
|
5
|
Righetto RD, Anton L, Adaixo R, Jakob RP, Zivanov J, Mahi MA, Ringler P, Schwede T, Maier T, Stahlberg H. High-resolution cryo-EM structure of urease from the pathogen Yersinia enterocolitica. Nat Commun 2020; 11:5101. [PMID: 33037208 PMCID: PMC7547064 DOI: 10.1038/s41467-020-18870-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2020] [Accepted: 09/15/2020] [Indexed: 01/09/2023] Open
Abstract
Urease converts urea into ammonia and carbon dioxide and makes urea available as a nitrogen source for all forms of life except animals. In human bacterial pathogens, ureases also aid in the invasion of acidic environments such as the stomach by raising the surrounding pH. Here, we report the structure of urease from the pathogen Yersinia enterocolitica at 2 Å resolution from cryo-electron microscopy. Y. enterocolitica urease is a dodecameric assembly of a trimer of three protein chains, ureA, ureB and ureC. The high data quality enables detailed visualization of the urease bimetal active site and of the impact of radiation damage. The obtained structure is of sufficient quality to support drug development efforts. Urease is a nickel enzyme responsible for catalyzing the conversion of urea into ammonia and carbon dioxide. Here the authors report a high resolution cryo-EM structure of urease from the bacterial pathogen Yersinia enterocolitica, providing a detailed visualization of the urease bimetal active site and a basis for drug development.
Collapse
Affiliation(s)
- Ricardo D Righetto
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Leonie Anton
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Ricardo Adaixo
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Roman P Jakob
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Jasenko Zivanov
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Mohamed-Ali Mahi
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Philippe Ringler
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland
| | - Torsten Schwede
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.,SIB Swiss Institute of Bioinformatics, Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland
| | - Timm Maier
- Biozentrum, University of Basel, Klingelbergstrasse 50/70, CH-4056, Basel, Switzerland.
| | - Henning Stahlberg
- Center for Cellular Imaging and NanoAnalytics, Biozentrum, University of Basel, Mattenstrasse 26, CH-4058, Basel, Switzerland.
| |
Collapse
|
6
|
Bozcal E. A general view on virulence determinants and infection strategies of Yersinia enterocolitica. MINERVA BIOTECNOL 2020. [DOI: 10.23736/s1120-4826.19.02582-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
7
|
Rego YF, Queiroz MP, Brito TO, Carvalho PG, de Queiroz VT, de Fátima Â, Macedo Jr. F. A review on the development of urease inhibitors as antimicrobial agents against pathogenic bacteria. J Adv Res 2018; 13:69-100. [PMID: 30094084 PMCID: PMC6077150 DOI: 10.1016/j.jare.2018.05.003] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 04/30/2018] [Accepted: 05/01/2018] [Indexed: 01/24/2023] Open
Abstract
Ureases are enzymes that hydrolyze urea into ammonium and carbon dioxide. They have received considerable attention due to their impacts on living organism health, since the urease activity in microorganisms, particularly in bacteria, are potential causes and/or factors contributing to the persistence of some pathogen infections. This review compiles examples of the most potent antiurease organic substances. Emphasis was given to systematic screening studies on the inhibitory activity of rationally designed series of compounds with the corresponding SAR considerations. Ureases of Canavalia ensiformis, the usual model in antiureolytic studies, are emphasized. Although the active site of this class of hydrolases is conserved among bacteria and vegetal ureases, the same is not observerd for allosteric site. Therefore, inhibitors acting by participating in interactions with the allosteric site are more susceptible to a potential lack of association among their inhibitory profile for different ureases. The information about the inhibitory activity of different classes of compounds can be usefull to guide the development of new urease inhibitors that may be used in future in small molecular therapy against pathogenic bacteria.
Collapse
Affiliation(s)
- Yuri F. Rego
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Marcelo P. Queiroz
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Tiago O. Brito
- Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Priscila G. Carvalho
- Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| | - Vagner T. de Queiroz
- Departamento de Química e Física, Centro de Ciências Exatas, Naturais e da Saúde, Universidade Federal do Espírito Santo, Alegre, ES, Brazil
| | - Ângelo de Fátima
- Departamento de Química, Instituto de Ciências Exatas, Universidade Federal de Minas Gerais, Belo Horizonte, MG, Brazil
| | - Fernando Macedo Jr.
- Departamento de Química, Centro de Ciências Exatas, Universidade Estadual de Londrina, Londrina, PR, Brazil
| |
Collapse
|
8
|
Kh ZH, Kh M, H B, I B, B MBAA. Safety characterization of Yersinia enterocolitica strains isolated from raw milk in Western Algeria. ACTA ACUST UNITED AC 2016. [DOI: 10.5897/ajmr2015.7839] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
|
9
|
Tikhomirova A, Jiang D, Kidd SP. A new insight into the role of intracellular nickel levels for the stress response, surface properties and twitching motility by Haemophilus influenzae. Metallomics 2016; 7:650-61. [PMID: 25350148 DOI: 10.1039/c4mt00245h] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Nickel acts as a co-factor for a small number of enzymes in bacteria. Urease is one of the two nickel-dependent enzymes that have been identified in Haemophilus influenzae; glyoxalase I is the other. However, nickel has been suggested to have roles in H. influenzae that can not attributed to the function of these enzymes. We have previously shown that in the H. influenzae strain Rd KW20 the inability to acquire nickel led to alterations to the cell-type; an increased biofilm formation and changes in cell surface properties. Here we report the differences in the genome wide gene expression between Rd KW20 and a strain incapable of importing nickel (nikQ); revealing a link between intracellular nickel levels and genes involved in metabolic pathways, stress responses and genes associated with surface factors such as type IV pili. We have then taken a strain previously shown to use type IV pili both in biofilm formation and for twitching motility (86-028NP) and have shown its homologous genes (NTHI1417-1422; annotated as cobalt transporter, cbiKLMOQ) did import nickel and mutations in this locus had pleiotropic effects correlating to stress response and motility. Compared to wild type cells, the nickel depleted cells were more electronegativity charged, they aggregated and formed a biofilm. Correct intracellular nickel levels were also important for resistance to oxidative stress; the nickel depleted cells were more sensitive to oxidative stress. The nickel depleted cells were also non-motile, but the addition specifically of nickel returned these cells to a wild type motility state. We have also analysed the role of nickel uptake in a naturally, urease negative strain (the blood isolate R2866) and depleting intracellular nickel (a nikQ mutant) in this strain effected a similar range of cell functions. These data reveal a role for the capacity to acquire nickel from the environment and for the correct intracellular nickel levels as part of H. influenzae stress response and in signalling for a switch to a sessile bacterial lifestyle.
Collapse
Affiliation(s)
- Alexandra Tikhomirova
- Research Centre for Infectious Disease, School of Molecular and Biomedical Science, The University of Adelaide, Adelaide, 5005, Australia.
| | | | | |
Collapse
|
10
|
|
11
|
Dhar MS, Virdi JS. Strategies used by Yersinia enterocolitica to evade killing by the host: thinking beyond Yops. Microbes Infect 2014; 16:87-95. [DOI: 10.1016/j.micinf.2013.11.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2013] [Revised: 10/04/2013] [Accepted: 11/05/2013] [Indexed: 02/07/2023]
|
12
|
Zadernowska A, Chajęcka-Wierzchowska W, Łaniewska-Trokenheim Ł. Yersinia enterocolitica: A Dangerous, But Often Ignored, Foodborne Pathogen. FOOD REVIEWS INTERNATIONAL 2013. [DOI: 10.1080/87559129.2013.853775] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
|
13
|
Dhar MS, Virdi JS. Interaction of Yersinia enterocolitica biovar 1A with cultured cells in vitro does not reflect the two previously identified clonal groups. J Med Microbiol 2013; 62:1807-1814. [PMID: 24037761 DOI: 10.1099/jmm.0.056077-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Yersinia enterocolitica biovar 1A strains have been delineated into two clonal groups (A and B) based on repetitive extragenic palindrome- and enterobacterial repetitive intergenic consensus-PCR genotyping. The present study investigated the interaction of Y. enterocolitica biovar 1A strains with cultured cells in vitro by their ability to adhere, invade and survive within these cells. The response of macrophages to these strains was also studied by quantifying the expression of inducible nitric oxide synthase, production of nitric oxide and cytokines, and activation of NFκB. The survival rate of clonal group B strains inside macrophages was significantly higher than that of clonal group A strains. In addition, strains harbouring the fepA gene showed better survival inside macrophages. However, the production of nitric oxide and cytokines and activation of NFκB did not show any significant differences between the two clonal groups. In this study, interaction of Y. enterocolitica biovar 1A with cultured cells in vitro did not reflect the previously identified clonal groups, but was more dependent on the characteristics of the individual strains. Therefore, a combination of genotype and phenotype data must be used to characterize this extremely heterogeneous organism.
Collapse
Affiliation(s)
- Mahesh S Dhar
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| | - Jugsharan S Virdi
- Microbial Pathogenicity Laboratory, Department of Microbiology, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India
| |
Collapse
|
14
|
Dhar MS, Kumar P, Virdi JS. Exogenous phage recombinase-independent inactivation of chromosomal genes in Yersinia enterocolitica. J Microbiol Methods 2013; 95:102-6. [PMID: 23928288 DOI: 10.1016/j.mimet.2013.07.023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 07/16/2013] [Accepted: 07/23/2013] [Indexed: 11/16/2022]
Abstract
Characterization of newly identified genes is necessary to understand their functions. Phenotypic characterization of isogenic mutants provides good understanding of the functions of the genes in wild type strains. In the present study, we report the use of linear dsDNA as a substrate for homologous recombination in Yersinia enterocolitica. A double-stranded linear recombinant DNA (LRD) containing an antibiotic resistance gene flanked by homologous regions to the target gene was created. Transformation of this LRD into Y. enterocolitica led to the replacement of targeted loci with antibiotic resistance gene. Using this strategy, two chromosomal genes namely urease C (ureC) and hemophore A (hasA) were disrupted in three strains of Y. enterocolitica. These recombinations were independent of the EPR functions. This is the first report of EPR-independent inactivation of chromosomal genes in Y. enterocolitica strains.
Collapse
Affiliation(s)
- Mahesh S Dhar
- Microbial Pathogenicity Laboratory, University of Delhi South Campus, Benito Juarez Road, New Delhi 110 021, India.
| | | | | |
Collapse
|
15
|
Bolton DJ, Ivory C, McDowell D. Thermal inactivation of Yersinia enterocolitica in pork slaughter plant scald tank water. Meat Sci 2013; 95:668-71. [PMID: 23279870 DOI: 10.1016/j.meatsci.2012.11.034] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 11/09/2012] [Accepted: 11/16/2012] [Indexed: 10/27/2022]
Abstract
The objective of this study was to establish the time-temperature combinations required to ensure the thermal inactivation of Yersinia enterocolitica during scalding of pork carcasses. A 2 strain cocktail of Y. enterocolitica (bioserotypes 2/O:5,27 and 1A/O:6,30) was heat treated at 50, 55 and 60°C in samples of scald tank water obtained from a commercial pork slaughter plant. Samples were removed at regular intervals and surviving cells enumerated using (i) Cefsulodin-Irgasan-Novobiocin Agar (CIN) supplemented with ampicillin and arabinose and (ii) Tryptone Soya Agar (TSA), overlaid with CIN agar with ampicillin and arabinose. The data generated was used to estimate D- and z-values and the formula Dx=log(-1)(log D60-((t2-t1)/z)) was applied to calculate thermal death time-temperature combinations from 55 to 65°C. D50, D55 and D60-values of 45.9, 10.6 and 2.7min were calculated from the cell counts obtained on CIN agar, respectively. The corresponding D-values calculated from the TSA/CIN counts were 45.1, 11 and 2.5min, respectively. The z-value was 7.8. It was concluded that a time-temperature combination of 2.7min at 60°C is required to achieve a 1 log reduction in Y. enterocolitica in pork scald tank water. The predicted equivalent at 65°C was 0.6min. This study provides data and a model to enable pork processors to identify and apply parameters to limit the risk of carcass cross-contamination with Y. enterocolitica in pork carcass scald tanks.
Collapse
Affiliation(s)
- Declan J Bolton
- Food Safety Department, Teagasc Food Research Centre, Ashtown, Dublin 15, Ireland.
| | | | | |
Collapse
|
16
|
De Biase D, Pennacchietti E. Glutamate decarboxylase-dependent acid resistance in orally acquired bacteria: function, distribution and biomedical implications of the gadBC operon. Mol Microbiol 2012; 86:770-86. [PMID: 22995042 DOI: 10.1111/mmi.12020] [Citation(s) in RCA: 108] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/28/2012] [Indexed: 02/06/2023]
Abstract
For successful colonization of the mammalian host, orally acquired bacteria must overcome the extreme acidic stress (pH < 2.5) encountered during transit through the host stomach. The glutamate-dependent acid resistance (GDAR) system is by far the most potent acid resistance system in commensal and pathogenic Escherichia coli, Shigella flexneri, Listeria monocytogenes and Lactococcus lactis. GDAR requires the activity of glutamate decarboxylase (GadB), an intracellular PLP-dependent enzyme which performs a proton-consuming decarboxylation reaction, and of the cognate antiporter (GadC), which performs the glutamatein /γ-aminobutyrateout (GABA) electrogenic antiport. Herein we review recent findings on the structural determinants responsible for pH-dependent intracellular activation of E. coli GadB and GadC. A survey of genomes of bacteria (pathogenic and non-pathogenic), having in common the ability to colonize or to transit through the host gut, shows that the gadB and gadC genes frequently lie next or near each other. This gene arrangement is likely to be important to ensure timely co-regulation of the decarboxylase and the antiporter. Besides the involvement in acid resistance, GABA production and release were found to occur at very high levels in lactic acid bacteria originally isolated from traditionally fermented foods, supporting the evidence that GABA-enriched foods possess health-promoting properties.
Collapse
Affiliation(s)
- Daniela De Biase
- Istituto Pasteur - Fondazione Cenci Bolognetti, Dipartimento di Scienze e Biotecnologie Medico-Chirurgiche, Sapienza Università di Roma, 04100, Latina, Italy.
| | | |
Collapse
|
17
|
Anderson KL, Roux CM, Olson MW, Luong TT, Lee CY, Olson R, Dunman PM. Characterizing the effects of inorganic acid and alkaline shock on the Staphylococcus aureus transcriptome and messenger RNA turnover. ACTA ACUST UNITED AC 2010; 60:208-50. [PMID: 21039920 DOI: 10.1111/j.1574-695x.2010.00736.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Staphylococcus aureus pathogenesis can be attributed partially to its ability to adapt to otherwise deleterious host-associated stresses. Here, Affymetrix GeneChips® were used to examine the S. aureus responses to inorganic acid and alkaline shock and to assess whether stress-dependent changes in mRNA turnover are likely to facilitate the organism's ability to tolerate a pH challenge. The results indicate that S. aureus adapts to pH shock by eliciting responses expected of cells coping with pH alteration, including neutralizing cellular pH, DNA repair, amino acid biosynthesis, and virulence factor expression. Further, the S. aureus response to alkaline conditions is strikingly similar to that of stringent response-induced cells. Indeed, we show that alkaline shock stimulates the accumulation of the stringent response activator (p)ppGpp. The results also revealed that pH shock significantly alters the mRNA properties of the cell. A comparison of the mRNA degradation properties of transcripts whose titers either increased or decreased in response to a sudden pH change revealed that alterations in mRNA degradation may, in part, account for the changes in the mRNA levels of factors predicted to mediate pH tolerance. A set of small stable RNA molecules were induced in response to acid- or alkaline-shock conditions and may mediate adaptation to pH stress.
Collapse
Affiliation(s)
- Kelsi L Anderson
- Department of Pathology and Microbiology, University of Nebraska Medical Center, Omaha, NE, USA
| | | | | | | | | | | | | |
Collapse
|
18
|
|