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Peñalver M, Paradela A, Palacios-Cuéllar C, Pucciarelli MG, García-Del Portillo F. Experimental evidence of d-glutamate racemase activity in the uncultivated bacterium Candidatus Saccharimonas aalborgensis. Environ Microbiol 2024; 26:e16621. [PMID: 38558504 DOI: 10.1111/1462-2920.16621] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2024] [Accepted: 03/16/2024] [Indexed: 04/04/2024]
Abstract
The Candidate Phyla Radiation (CPR) encompasses widespread uncultivated bacteria with reduced genomes and limited metabolic capacities. Most CPR bacteria lack the minimal set of enzymes required for peptidoglycan (PG) synthesis, leaving it unclear how these bacteria produce this essential envelope component. In this study, we analysed the distribution of d-amino acid racemases that produce the universal PG components d-glutamate (d-Glu) or d-alanine (d-Ala). We also examined moonlighting enzymes that synthesize d-Glu or d-Ala. Unlike other phyla in the domain Bacteria, CPR bacteria do not exhibit these moonlighting activities and have, at most, one gene encoding either a Glu or Ala racemase. One of these 'orphan' racemases is a predicted Glu racemase (MurICPR) from the CPR bacterium Candidatus Saccharimonas aalborgenesis. The expression of MurICPR restores the growth of a Salmonella d-Glu auxotroph lacking its endogenous racemase and results in the substitution of l-Ala by serine as the first residue in a fraction of the PG stem peptides. In vitro, MurICPR exclusively racemizes Glu as a substrate. Therefore, Ca. Saccharimonas aalborgensis may couple Glu racemization to serine and d-Glu incorporation into the stem peptide. Our findings provide the first insights into the synthesis of PG by an uncultivated environmental bacterium and illustrate how to experimentally test enzymatic activities from CPR bacteria related to PG metabolism.
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Affiliation(s)
- Marcos Peñalver
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Biologia Molecular Severo Ochoa (CBM), CSIC-UAM, Madrid, Spain
| | - Alberto Paradela
- Proteomics Facility, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
| | - César Palacios-Cuéllar
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
| | - M Graciela Pucciarelli
- Laboratory of Intracellular Bacterial Pathogens, National Centre for Biotechnology (CNB-CSIC), Madrid, Spain
- Department of Molecular Biology, Universidad Autónoma de Madrid (UAM), Madrid, Spain
- Centro de Biologia Molecular Severo Ochoa (CBM), CSIC-UAM, Madrid, Spain
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Comparison of Phenotype and Genotype Virulence and Antimicrobial Factors of Salmonella Typhimurium Isolated from Human Milk. Int J Mol Sci 2023; 24:ijms24065135. [PMID: 36982209 PMCID: PMC10048834 DOI: 10.3390/ijms24065135] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/03/2023] [Accepted: 03/04/2023] [Indexed: 03/11/2023] Open
Abstract
Salmonella is a common foodborne infection. Many serovars belonging to Salmonella enterica subsp. enterica are present in the gut of various animal species. They can cause infection in human infants via breast milk or cross-contamination with powdered milk. In the present study, Salmonella BO was isolated from human milk in accordance with ISO 6579-1:2017 standards and sequenced using whole-genome sequencing (WGS), followed by serosequencing and genotyping. The results also allowed its pathogenicity to be predicted. The WGS results were compared with the bacterial phenotype. The isolated strain was found to be Salmonella enterica subsp. enterica serovar Typhimurium 4:i:1,2_69M (S. Typhimurium 69M); it showed a very close similarity to S. enterica subsp. enterica serovar Typhimurium LT2. Bioinformatics sequence analysis detected eleven SPIs (SPI-1, SPI-2, SPI-3, SPI-4, SPI-5, SPI-9, SPI-12, SPI-13, SPI-14, C63PI, CS54_island). Significant changes in gene sequences were noted, causing frameshift mutations in yeiG, rfbP, fumA, yeaL, ybeU (insertion) and lpfD, avrA, ratB, yacH (deletion). The sequences of several proteins were significantly different from those coded in the reference genome; their three-dimensional structure was predicted and compared with reference proteins. Our findings indicate the presence of a number of antimicrobial resistance genes that do not directly imply an antibiotic resistance phenotype.
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Halimi A, Gabarrini G, Sobkowiak MJ, Ateeb Z, Davanian H, Gaiser RA, Arnelo U, Valente R, Wong AY, Moro CF, Del Chiaro M, Özenci V, Chen MS. Isolation of pancreatic microbiota from cystic precursors of pancreatic cancer with intracellular growth and DNA damaging properties. Gut Microbes 2022; 13:1983101. [PMID: 34816784 PMCID: PMC8632270 DOI: 10.1080/19490976.2021.1983101] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Emerging research suggests gut microbiome may play a role in pancreatic cancer initiation and progression, but cultivation of the cancer microbiome remains challenging. This pilot study aims to investigate the possibility to cultivate pancreatic microbiome from pancreatic cystic lesions associated with invasive cancer. Intra-operatively acquired pancreatic cyst fluid samples showed culture-positivity mainly in the intraductal papillary mucinous neoplasm (IPMN) group of lesions. MALDI-TOF MS profiling analysis shows Gammaproteobacteria and Bacilli dominate among individual bacteria isolates. Among cultivated bacteria, Gammaproteobacteria, particularly Klebsiella pneumoniae, but also Granulicatella adiacens and Enterococcus faecalis, demonstrate consistent pathogenic properties in pancreatic cell lines tested in ex vivo co-culture models. Pathogenic properties include intracellular survival capability, cell death induction, or causing DNA double-strand breaks in the surviving cells resembling genotoxic effects. This study provides new insights into the role of the pancreatic microbiota in the intriguing link between pancreatic cystic lesions and cancer.
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Affiliation(s)
- Asif Halimi
- Division of Surgery, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden,Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden
| | - Giorgio Gabarrini
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
| | | | - Zeeshan Ateeb
- Division of Surgery, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden
| | - Haleh Davanian
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
| | | | - Urban Arnelo
- Division of Surgery, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden,Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden
| | - Roberto Valente
- Division of Surgery, Department of Clinical Science, Intervention and Technology, Karolinska Institutet, Stockholm, Sweden,Department of Surgical and Perioperative Sciences, Surgery, Umeå University, Umeå, Sweden
| | - Alicia Y.W. Wong
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden,Department of Clinical Microbiology F 72, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Carlos Fernández Moro
- Division of Pathology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden,Department of Clinical Pathology/Cytology, Karolinska University Hospital, Huddinge, Sweden
| | - Marco Del Chiaro
- Department of Surgery, University of Colorado Denver – Anschutz Medical Campus, Aurora, CO, USA
| | - Volkan Özenci
- Division of Clinical Microbiology, Department of Laboratory Medicine, Karolinska Institutet, Huddinge, Sweden,Department of Clinical Microbiology F 72, Karolinska University Hospital, Huddinge, Stockholm, Sweden
| | - Margaret Sällberg Chen
- Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden,CONTACT Margaret Sällberg Chen Department of Dental Medicine, Karolinska Institutet, Huddinge14141, Sweden
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Abuaita BH, Lawrence ALE, Berger RP, Hill DR, Huang S, Yadagiri VK, Bons B, Fields C, Wobus CE, Spence JR, Young VB, O’Riordan MX. Comparative transcriptional profiling of the early host response to infection by typhoidal and non-typhoidal Salmonella serovars in human intestinal organoids. PLoS Pathog 2021; 17:e1009987. [PMID: 34669717 PMCID: PMC8570492 DOI: 10.1371/journal.ppat.1009987] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Revised: 11/05/2021] [Accepted: 09/28/2021] [Indexed: 12/18/2022] Open
Abstract
Salmonella enterica represents over 2500 serovars associated with a wide-ranging spectrum of disease; from self-limiting gastroenteritis to invasive infections caused by non-typhoidal serovars (NTS) and typhoidal serovars, respectively. Host factors strongly influence infection outcome as malnourished or immunocompromised individuals can develop invasive infections from NTS, however, comparative analyses of serovar-specific host responses have been constrained by reliance on limited model systems. Here we used human intestinal organoids (HIOs), a three-dimensional “gut-like” in vitro system derived from human embryonic stem cells, to elucidate similarities and differences in host responses to NTS and typhoidal serovars. HIOs discriminated between the two most prevalent NTS, Salmonella enterica serovar Typhimurium (STM) and Salmonella enterica serovar Enteritidis (SE), and typhoidal serovar Salmonella enterica serovar Typhi (ST) in epithelial cell invasion, replication and transcriptional responses. Pro-inflammatory signaling and cytokine output was reduced in ST-infected HIOs compared to NTS infections, consistent with early stages of NTS and typhoidal diseases. While we predicted that ST would induce a distinct transcriptional profile from the NTS strains, more nuanced expression profiles emerged. Notably, pathways involved in cell cycle, metabolism and mitochondrial functions were downregulated in STM-infected HIOs and upregulated in SE-infected HIOs. These results correlated with suppression of cellular proliferation and induction of host cell death in STM-infected HIOs and in contrast, elevated levels of reactive oxygen species production in SE-infected HIOs. Collectively, these results suggest that the HIO model is well suited to reveal host transcriptional programming specific to infection by individual Salmonella serovars, and that individual NTS may provoke unique host epithelial responses during intestinal stages of infection. Salmonella enterica is the major causative agent of bacterial infections associated with contaminated food and water. Salmonella enterica consists of over 2500 serovars of which Typhimurium (STM), Enteritidis (SE) and Typhi (ST) are the three major serovars with medical relevance to humans. These serovars elicit distinctive immune responses and cause different diseases in humans, including self-limiting diarrhea, gastroenteritis and typhoid fever. Differences in the human host response to these serovars are likely to be a major contributing factor to distinct disease outcomes but are not well characterized, possibly due to the limitations of human-derived physiological infection models. Distinct from immortalized epithelial cell culture models, human intestinal organoids (HIOs) are three-dimensional structures derived from embryonic stem cells that differentiate into intestinal mesenchymal and epithelial cells, mirroring key organizational aspects of the intestine. In this study, we used HIOs to monitor transcriptional changes during early stages of STM, SE and ST infection. Our comparative analysis showed that HIO inflammatory responses are the dominant response in all infections, but ST infection induces the weakest upregulation of inflammatory mediators relative to the other serovars. In addition, we identified several cellular processes, including cell cycle and mitochondrial functions, that were inversely regulated between STM and SE infection despite these serovars causing similar localized intestinal infection in humans. Our findings reinforce HIOs as an emerging model system to study Salmonella serovar infection and define global host transcriptional response profiles as a foundation for understanding human infection outcomes.
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Affiliation(s)
- Basel H. Abuaita
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Anna-Lisa E. Lawrence
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Ryan P. Berger
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - David R. Hill
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Sha Huang
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Veda K. Yadagiri
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Brooke Bons
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Courtney Fields
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Christiane E. Wobus
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Jason R. Spence
- Department of Cell and Developmental Biology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Vincent B. Young
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Mary X. O’Riordan
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
- * E-mail:
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Taniguchi K, Ikeda Y, Nagase N, Tsuji A, Kitagishi Y, Matsuda S. Implications of Gut-Brain axis in the pathogenesis of Psychiatric disorders. AIMS BIOENGINEERING 2021. [DOI: 10.3934/bioeng.2021021] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
<abstract>
<p>Psychiatric disorders may extremely impair the quality of life with patients and are important reasons of social disability. Several data have shown that psychiatric disorders are associated with an altered composition of gut microbiota. Dietary intake could determine the microbiota, which contribute to produce various metabolites of fermentation such as short chain fatty acids. Some of the metabolites could result in epigenetic alterations leading to the disease susceptibility. Epigenetic dysfunction is in fact implicated in various psychiatric and neurologic disorders. For example, it has been shown that neuroepigenetic dysregulation occurs in psychiatric disorders including schizophrenia. Several studies have demonstrated that the intestinal microbiome may influence the function of central nervous system. Furthermore, it has been proved that the alterations in the gut microbiota-composition might affect in the bidirectional communication between gut and brain. Similarly, evidences demonstrating the association between psychiatric disorders and the gut microbiota have come from preclinical studies. It is clear that an intricate symbiotic relationship might exist between host and microbe, although the practical significance of the gut microbiota has not yet to be determined. In this review, we have summarized the function of gut microbiota in main psychiatric disorders with respect to the mental health. In addition, we would like to discuss the potential mechanisms of the disorders for the practical diagnosis and future treatment by using bioengineering of microbiota and their metabolites.</p>
</abstract>
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Das S, Ray S, Arunima A, Sahu B, Suar M. A ROD9 island encoded gene in Salmonella Enteritidis plays an important role in acid tolerance response and helps in systemic infection in mice. Virulence 2020; 11:247-259. [PMID: 32116124 PMCID: PMC7051147 DOI: 10.1080/21505594.2020.1733203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 11/26/2019] [Accepted: 12/02/2019] [Indexed: 10/31/2022] Open
Abstract
Salmonella, like other pathogenic bacteria has undergone multiple genomic alterations to adapt itself into specific host environments executing varied degrees of virulence through evolution. Such variations in genome content have been assumed to lead the closely related non-typhoidal serovars, S. Enteritidis, and S. Typhimurium to exhibit Type Three Secretion System -2 (T3SS-2) based diverse colonization and inflammation kinetics. Mutually exclusive genes present in either of the serovars are recently being studied and in our currentwork, we focused on a particular island ROD9, present in S. Enteritidis but not in S. Typhimurium. Earlier reports have identified a few genes from this island to be responsible for virulence in vitro as well as in vivo. In this study, we have identified another gene, SEN1008 from the same island encoding a hypothetical protein to be a potential virulence determinant showing systemic attenuation upon mutation in C57BL/6 mice infection model. The isogenic mutant strain displayed reduced adhesion to epithelial cells in vitro as well as was highly immotile. It was also deficient in intracellular replication in vitro, with a highly suppressed SPI-2and failed to cause acute colitis at 72-h p.i.in vivo. Moreover, on acid exposure, SEN1008 showed 17 folds and 2 fold up-regulations during adaptation and challenge phases,respectively and ΔSEN1008 failed to survive during ATR assay, indicating its role under acid stress. Together, our findings suggested ΔSEN1008 to be significantly attenuated and we propose this gene to be a potent factor responsible for S. Enteritidis pathogenesis.
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Affiliation(s)
- Susmita Das
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | - Shilpa Ray
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | | | - Bikash Sahu
- School of Biotechnology, KIIT University, Bhubaneswar, India
| | - Mrutyunjay Suar
- School of Biotechnology, KIIT University, Bhubaneswar, India
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Henríquez T, Salazar JC, Marvasi M, Shah A, Corsini G, Toro CS. SRL pathogenicity island contributes to the metabolism of D-aspartate via an aspartate racemase in Shigella flexneri YSH6000. PLoS One 2020; 15:e0228178. [PMID: 31978153 PMCID: PMC6980539 DOI: 10.1371/journal.pone.0228178] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Accepted: 01/08/2020] [Indexed: 01/20/2023] Open
Abstract
In recent years, multidrug resistance of Shigella strains associated with genetic elements like pathogenicity islands, have become a public health problem. The Shigella resistance locus pathogenicity island (SRL PAI) of S. flexneri 2a harbors a 16Kbp region that contributes to the multidrug resistance phenotype. However, there is not much information about other functions such as metabolic, physiologic or ecological ones. For that, wild type S. flexneri YSH6000 strain, and its spontaneous SRL PAI mutant, 1363, were used to study the contribution of the island in different growth conditions. Interestingly, when both strains were compared by the Phenotype Microarrays, the ability to metabolize D-aspartic acid as a carbon source was detected in the wild type strain but not in the mutant. When D-aspartate was added to minimal medium with other carbon sources such as mannose or mannitol, the SRL PAI-positive strain was able to metabolize it, while the SRL PAI-negative strain did not. In order to identify the genetic elements responsible for this phenotype, a bioinformatic analysis was performed and two genes belonging to SRL PAI were found: orf8, coding for a putative aspartate racemase, and orf9, coding for a transporter. Thus, it was possible to measure, by an indirect analysis of racemization activity in minimal medium supplemented only with D-aspartate, that YSH6000 strain was able to transform the D-form into L-, while the mutant was impaired to do it. When the orf8-orf9 region from SRL island was transformed into S. flexneri and S. sonnei SRL PAI-negative strains, the phenotype was restored. Although, when single genes were cloned into plasmids, no complementation was observed. Our results strongly suggest that the aspartate racemase and the transporter encoded in the SRL pathogenicity island are important for bacterial survival in environments rich in D-aspartate.
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Affiliation(s)
- Tania Henríquez
- Programa de Microbiología y Micología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- Biozentrum, Ludwig-Maximilians-Universität München, Martinsried, Germany
| | - Juan Carlos Salazar
- Programa de Microbiología y Micología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | | | - Ajit Shah
- Middlesex University London, The Burroughs, London, United Kingdom
| | - Gino Corsini
- Instituto de Ciencias Biomédicas, Universidad Autónoma de Chile, Santiago, Chile
| | - Cecilia S. Toro
- Programa de Microbiología y Micología, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
- * E-mail:
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Muhammad M, Li Y, Gong S, Shi Y, Ju J, Zhao B, Liu D. Purification, Characterization and Inhibition of Alanine Racemase from a Pathogenic Strain of Streptococcus iniae. Pol J Microbiol 2019; 68:331-341. [PMID: 31880879 PMCID: PMC7256847 DOI: 10.33073/pjm-2019-036] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2019] [Revised: 07/10/2019] [Accepted: 07/10/2019] [Indexed: 01/25/2023] Open
Abstract
Streptococcus iniae is a pathogenic and zoonotic bacteria that impacted high mortality to many fish species as well as capable of causing serious disease to humans. Alanine racemase (Alr, EC 5.1.1.1) is a pyridoxal-5’-phosphate (PLP)-containing homodimeric enzyme that catalyzes the racemization of L-alanine and D-alanine. In this study, we purified alanine racemase from S. iniae that was isolated from an infected Chinese sturgeon (Acipenser sinensis), as well as determined its biochemical characteristics and inhibitors. The alr gene has an open reading frame (ORF) of 1107 bp, encoding a protein of 369 amino acids, which has a molecular mass of 40 kDa. The enzyme has optimal activity at a temperature of 35°C and a pH of 9.5. It belongs to the PLP-dependent enzymes family and is highly specific to L-alanine. S. iniae Alr (SiAlr) could be inhibited by some metal ions, hydroxylamine and dithiothreitol (DTT). The kinetic parameters Km and Vmax of the enzyme were 33.11 mM, 2426 units/mg for L-alanine, and 14.36 mM, 963.6 units/mg for D-alanine. Finally, the 50% inhibitory concentrations (IC50) values and antibiotic activity of two alanine racemase inhibitors (homogentisic acid and hydroquinone), were determined and found to be effective against both Gram-positive and Gram-negative bacteria employed in this study.
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Affiliation(s)
- Murtala Muhammad
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Yangyang Li
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Siyu Gong
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Yanmin Shi
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Jiansong Ju
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Baohua Zhao
- College of Life Science, Hebei Normal University , Shijiazhuang , China
| | - Dong Liu
- College of Life Science, Hebei Normal University , Shijiazhuang , China
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