1
|
Tajer L, Paillart JC, Dib H, Sabatier JM, Fajloun Z, Abi Khattar Z. Molecular Mechanisms of Bacterial Resistance to Antimicrobial Peptides in the Modern Era: An Updated Review. Microorganisms 2024; 12:1259. [PMID: 39065030 PMCID: PMC11279074 DOI: 10.3390/microorganisms12071259] [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: 05/08/2024] [Revised: 06/10/2024] [Accepted: 06/18/2024] [Indexed: 07/28/2024] Open
Abstract
Antimicrobial resistance (AMR) poses a serious global health concern, resulting in a significant number of deaths annually due to infections that are resistant to treatment. Amidst this crisis, antimicrobial peptides (AMPs) have emerged as promising alternatives to conventional antibiotics (ATBs). These cationic peptides, naturally produced by all kingdoms of life, play a crucial role in the innate immune system of multicellular organisms and in bacterial interspecies competition by exhibiting broad-spectrum activity against bacteria, fungi, viruses, and parasites. AMPs target bacterial pathogens through multiple mechanisms, most importantly by disrupting their membranes, leading to cell lysis. However, bacterial resistance to host AMPs has emerged due to a slow co-evolutionary process between microorganisms and their hosts. Alarmingly, the development of resistance to last-resort AMPs in the treatment of MDR infections, such as colistin, is attributed to the misuse of this peptide and the high rate of horizontal genetic transfer of the corresponding resistance genes. AMP-resistant bacteria employ diverse mechanisms, including but not limited to proteolytic degradation, extracellular trapping and inactivation, active efflux, as well as complex modifications in bacterial cell wall and membrane structures. This review comprehensively examines all constitutive and inducible molecular resistance mechanisms to AMPs supported by experimental evidence described to date in bacterial pathogens. We also explore the specificity of these mechanisms toward structurally diverse AMPs to broaden and enhance their potential in developing and applying them as therapeutics for MDR bacteria. Additionally, we provide insights into the significance of AMP resistance within the context of host-pathogen interactions.
Collapse
Affiliation(s)
- Layla Tajer
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
| | - Jean-Christophe Paillart
- CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Université de Strasbourg, 2 Allée Konrad Roentgen, F-67000 Strasbourg, France;
| | - Hanna Dib
- College of Engineering and Technology, American University of the Middle East, Egaila 54200, Kuwait;
| | - Jean-Marc Sabatier
- CNRS, INP, Inst Neurophysiopathol, Aix-Marseille Université, 13385 Marseille, France
| | - Ziad Fajloun
- Laboratory of Applied Biotechnology (LBA3B), Azm Center for Research in Biotechnology and Its Applications, Department of Cell Culture, EDST, Lebanese University, Tripoli 1300, Lebanon; (L.T.); (Z.F.)
- Department of Biology, Faculty of Sciences 3, Lebanese University, Campus Michel Slayman Ras Maska, Tripoli 1352, Lebanon
| | - Ziad Abi Khattar
- Faculty of Medicine and Medical Sciences, University of Balamand, Kalhat, P.O. Box 100, Tripoli, Lebanon
| |
Collapse
|
2
|
Ma J, Wu H, Ma Z, Wu Z. Bacterial and host factors involved in zoonotic Streptococcal meningitis. Microbes Infect 2024:105335. [PMID: 38582147 DOI: 10.1016/j.micinf.2024.105335] [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: 02/01/2024] [Revised: 04/01/2024] [Accepted: 04/02/2024] [Indexed: 04/08/2024]
Abstract
Zoonotic streptococci cause several invasive diseases with high mortality rates, especially meningitis. Numerous studies elucidated the meningitis pathogenesis of zoonotic streptococci, some specific to certain bacterial species. In contrast, others are shared among different bacterial species, involving colonization and invasion of mucosal barriers, survival in the bloodstream, breaching the blood-brain and/or blood-cerebrospinal fluid barrier to access the central nervous system, and triggering inflammation of the meninges. This review focuses on the recent advancements in comprehending the molecular and cellular events of five major zoonotic streptococci responsible for causing meningitis in humans or animals, including Streptococcus agalactiae, Streptococcus equi subspecies zooepidemicus, Streptococcus suis, Streptococcus dysgalactiae, and Streptococcus iniae. The underlying mechanism was summarized into four themes, including 1) bacterial survival in blood, 2) brain microvascular endothelial cell adhesion and invasion, 3) penetration of the blood-brain barrier, and 4) activation of the immune system and inflammatory reaction within the brain. This review may contribute to developing therapeutics to prevent or mitigate injury of streptococcal meningitis and improve risk stratification.
Collapse
Affiliation(s)
- Jiale Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Huizhen Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China
| | - Zhe Ma
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, China.
| | - Zongfu Wu
- MOE Joint International Research Laboratory of Animal Health and Food Safety, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210014, China; Key Lab of Animal Bacteriology, Ministry of Agriculture, Nanjing 210014, China; WOAH Reference Lab for Swine Streptococcosis, Nanjing 210014, China; Guangdong Provincial Key Laboratory of Research on the Technology of Pig-breeding and Pig-disease Prevention, Guangzhou 511400, China.
| |
Collapse
|
3
|
Xu H, Zhu N, Chen Y, Yue H, Zhuo M, Wangkahart E, Liang Q, Wang R. Pathogenicity of Streptococcus iniae causing mass mortalities of yellow catfish ( Tachysurus fulvidraco) and its induced host immune response. Front Microbiol 2024; 15:1374688. [PMID: 38585696 PMCID: PMC10995319 DOI: 10.3389/fmicb.2024.1374688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Accepted: 02/26/2024] [Indexed: 04/09/2024] Open
Abstract
The outbreak of mass mortality occurred in Tachysurus fulvidraco farm in Hubei province of China. The pathogenic strain of Streptococcus iniae (termed 2022SI08) was isolated and identified from diseased T. fulvidraco, based on morphological, physiological, and biochemical characteristics, as well as 16S rRNA gene sequence and phylogenetic analysis. Further, the whole genome of isolate S. iniae was sequenced and predicted to contain one single circular chromosome of 1,776,777 bp with a GC content of 37.14%. The genomic sequence analysis showed that 2022SI08 was positive for 204 virulent and 127 antibiotic resistant genes. The experimental challenge demonstrated the high pathogenicity of the retrieved isolate of S. iniae, with a median lethal dosage (LD50) 9.53 × 105 CFU/g. Histopathological examination indicated that the 2022SI08 strain could induce extensive tissue cell degeneration, necrosis, hemorrhage, and inflammation in the skin, gill, fin, spleen, liver, kidney, intestine, eye, and brain. Moreover, the innate immune enzyme activities in serum such as acid phosphatase and alkaline phosphatase were increased significantly at 24 and 48 h post infection (hpi) and then decreased at 168 hpi. The transcriptional profile of immune associated gene in T. fulvidraco following bacterial infection was detected at each point of time, and the results revealed clear transcriptional activation of those genes, which proving their reacting and regulatory role during the response of the host against S. iniae infection. The results revealed that S. iniae was an etiological agent in the mass mortalities of T. fulvidraco and this research will be conducive for increasing our understanding on pathogenesis and host defensive system in S. iniae invasion.
Collapse
Affiliation(s)
- Hongsen Xu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, China
| | - Nengbin Zhu
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, China
| | - Yiling Chen
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, China
| | - Huamei Yue
- Key Lab of Freshwater Biodiversity Conservation Ministry of Agriculture and Rural Affairs of China, Yangtze River Fisheries Research Institute, CAFS, Wuhan, China
| | - Meiqin Zhuo
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, China
| | - Eakapol Wangkahart
- Laboratory of Fish Immunology and Nutrigenomics, Applied Animal and Aquatic Sciences Research Unit, Division of Fisheries, Faculty of Technology, Mahasarakham University, Mahasarakham, Thailand
| | - Qianrong Liang
- Zhejiang Fisheries Technical Extension Center, and Zhejiang Fisheries Test and Aquatic Disease Prevention Center, Hangzhou, China
| | - Rui Wang
- Hubei Key Laboratory of Animal Nutrition and Feed Science, School of Animal Science and Nutritional Engineering, Wuhan Polytechnic University, Wuhan, China
| |
Collapse
|
4
|
Xiong X, Chen R, Lai J. Comparative genomics analysis of Streptococcus iniae isolated from Trachinotus ovatus: novel insight into antimicrobial resistance and virulence differentiation. BMC Genomics 2023; 24:775. [PMID: 38097934 PMCID: PMC10720119 DOI: 10.1186/s12864-023-09882-5] [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: 09/19/2023] [Accepted: 12/07/2023] [Indexed: 12/18/2023] Open
Abstract
BACKGROUND Streptococcus iniae is an important fish pathogen that cause significant economic losses to the global aquaculture industry every year. Although there have some reports on the genotype of S.iniae and its relationship with virulence, no genome-scale comparative analysis has been performed so far. In our previous work, we characterized 17 isolates of S.iniae from Trachinotus ovatus and divided them into two genotypes using RAPD and rep-PCR methods. Among them, BH15-2 was classified as designated genotype A (in RAPD) and genotype 1 (in rep-PCR), while BH16-24 was classified as genotype B and genotype 2. Herein, we compared the differences in growth, drug resistance, virulence, and genome between BH15-2 and BH16-24. RESULTS The results showed that the growth ability of BH16-24 was significantly faster than that of BH15-2 at the exponential stage. Antimicrobial tests revealed that BH15-2 was susceptible to most of the tested antibiotics except neomycin and gentamycin. In contrast, BH16-24 was resistant to 7 antibiotics including penicillin, sulfasomizole, compound sulfamethoxazole tablets, polymyxin B, spectinomycin, rifampin and ceftazidime. Intraperitoneal challenge of T.ovatus, showed that the LD50 value of BH15-2 was 4.0 × 102 CFU/g, while that of BH16-24 was 1.2 × 105 CFU/g. The genome of S.iniae BH15-2 was 2,175,659 bp with a GC content of 36.80%. Meanwhile, the genome of BH16-24 was 2,153,918 bp with a GC content of 36.83%. Comparative genome analysis indicated that compared with BH15-2, BH16-24 genome had a large-scale genomic inversion fragment, at the location from 502,513 bp to 1,788,813 bp, resulting in many of virulence and resistance genes differentially expression. In addition, there was a 46 kb length, intact phage sequence in BH15-2 genome, which was absent in BH16-24. CONCLUSION Comparative genomic studies of BH15-2 and BH16-24 showed that the main difference is a 1.28 Mbp inversion fragment. The inversion fragment may lead to abnormal expression of drug resistant and virulence genes, which is believed to be the main reason for the multiple resistance and weakened virulence of BH16-24. Our study revealed the potential mechanisms in underlying the differences of multidrug resistance and virulence among different genotypes of S.iniae.
Collapse
Affiliation(s)
- Xiangying Xiong
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Marine Sciences, Guangxi Academy of Sciences, 98 Daling Road, Nanning, 530007, Guangxi, China.
- Guangxi Institute of Oceanology Limited Liability Company, Beihai, 536000, Guangxi, China.
- Beibu Gulf Marine Industry Research Institute, Fangchenggang, 538000, Guangxi, China.
| | - Ruifang Chen
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Marine Sciences, Guangxi Academy of Sciences, 98 Daling Road, Nanning, 530007, Guangxi, China
- Guangxi Institute of Oceanology Limited Liability Company, Beihai, 536000, Guangxi, China
- Beibu Gulf Marine Industry Research Institute, Fangchenggang, 538000, Guangxi, China
| | - Junxiang Lai
- Guangxi Key Laboratory of Marine Environmental Science, Guangxi Academy of Marine Sciences, Guangxi Academy of Sciences, 98 Daling Road, Nanning, 530007, Guangxi, China
- Beibu Gulf Marine Industry Research Institute, Fangchenggang, 538000, Guangxi, China
| |
Collapse
|
5
|
Streptococcosis a Re-Emerging Disease in Aquaculture: Significance and Phytotherapy. Animals (Basel) 2022; 12:ani12182443. [PMID: 36139303 PMCID: PMC9495100 DOI: 10.3390/ani12182443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2022] [Revised: 09/07/2022] [Accepted: 09/12/2022] [Indexed: 11/25/2022] Open
Abstract
Simple Summary Streptococcosis is an economical important bacterial disease that can seriously cause huge losses in the global aquaculture sector. In recent years studies have focused on to use extracts or essences of medicinal herbs and plants to control or treat the disease outbreaks and, in most cases the results were promising. The essential oils of the herbs or plants are more effective than the extracts and, the extracts examined have moderate efficacy in term of increasing fish survival against fish streptococcosis that could be due to the enhancement of fish immunity by the herb bio-compounds. The lack of dosage optimization, toxicity and bioavailability assays of a specific herb/plant or its bioactive compound in fish organs make it difficult to judge the validation of clinical efficacy of a particular herb/plant against fish streptococcosis, and thus, required further investigations. Abstract Streptococcosis, particularly that caused by S. iniae and S. agalactiae, is a major re-emerging bacterial disease seriously affecting the global sustainability of aquaculture development. Despite a wide spread of the disease in aquaculture, few studies have been directed at assessing the in vitro antagonistic activity and in vivo efficacy of medicinal herbs and other plants against streptococcal agents. Most in vitro studies of plant extractives against S. iniae and S. agalactiae have found antibacterial activity, but essential oils, especially those containing eugenol, carvacrol or thymol, are more effective. Although essential oils have shown better anti-streptococcal activity in in vitro assays, in vivo bioassays require more attention. The extracts examined under in vivo conditions show moderate efficacy, increasing the survival rate of infected fish, probably through the enhancement of immunity before challenge bioassays. The available data, however, lack dosage optimization, toxicity and bioavailability assays of a specific plant or its bioactive compound in fish organs; hence, it is difficult to judge the validation of clinical efficacy for the prevention or treatment of fish streptococcosis. Despite the known bioactive compounds of many tested plants, few data are available on their mode of action towards streptococcal agents. This review addresses the efficacy of medicinal plants to fish streptococcosis and discusses the current gaps.
Collapse
|
6
|
Host–Pathogen Interactions of Marine Gram-Positive Bacteria. BIOLOGY 2022; 11:biology11091316. [PMID: 36138795 PMCID: PMC9495620 DOI: 10.3390/biology11091316] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Complex interactions between marine Gram-positive pathogens and fish hosts in the marine environment can result in diseases of economically important finfish, which cause economic losses in the aquaculture industry. Understanding how these pathogens interact with the fish host and generate disease will contribute to efficient prophylactic measures and treatments. To our knowledge, there are no systematic reviews on marine Gram-positive pathogens. Therefore, here we reviewed the host–pathogen interactions of marine Gram-positive pathogens from the pathogen-centric and host-centric points of view. Abstract Marine Gram-positive bacterial pathogens, including Renibacterium salmoninarum, Mycobacterium marinum, Nocardia seriolae, Lactococcus garvieae, and Streptococcus spp. cause economic losses in marine fish aquaculture worldwide. Comprehensive information on these pathogens and their dynamic interactions with their respective fish–host systems are critical to developing effective prophylactic measures and treatments. While much is known about bacterial virulence and fish immune response, it is necessary to synthesize the knowledge in terms of host–pathogen interactions as a centerpiece to establish a crucial connection between the intricate details of marine Gram-positive pathogens and their fish hosts. Therefore, this review provides a holistic view and discusses the different stages of the host–pathogen interactions of marine Gram-positive pathogens. Gram-positive pathogens can invade fish tissues, evade the fish defenses, proliferate in the host system, and modulate the fish immune response. Marine Gram-positive pathogens have a unique set of virulence factors that facilitate adhesion (e.g., adhesins, hemagglutination activity, sortase, and capsules), invasion (e.g., toxins, hemolysins/cytolysins, the type VII secretion system, and immune-suppressive proteins), evasion (e.g., free radical quenching, actin-based motility, and the inhibition of phagolysosomal fusion), and proliferation and survival (e.g., heme utilization and siderophore-mediated iron acquisition systems) in the fish host. After infection, the fish host initiates specific innate and adaptive immune responses according to the extracellular or intracellular mechanism of infection. Although efforts have continued to be made in understanding the complex interplay at the host–pathogen interface, integrated omics-based investigations targeting host–pathogen–marine environment interactions hold promise for future research.
Collapse
|
7
|
Wu M, Huang S, Du J, Li Y, Jiang S, Zhan L, Huang X. D-alanylation of lipoteichoic acid contributes to biofilm formation and acidogenesis capacity of Streptococcusmutans. Microb Pathog 2022; 169:105666. [PMID: 35811023 DOI: 10.1016/j.micpath.2022.105666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2022] [Revised: 05/15/2022] [Accepted: 07/01/2022] [Indexed: 11/19/2022]
Abstract
BACKGROUND D-alanylation of Lipoteichoic acid (LTA) is considered to be essential for virulence factors expression in Gram-positive microorganism. The effects of the D-alanylation of LTA on biofilm formation and acidogenesis of Streptococcus mutans (S. mutans) are still not clearly understood. AIM This study was designed to investigate the impact of D-alanylation of LTA on biofilm formation and acidogenesis of S. mutans and explore the related mechanisms. METHODS AND MATERIAL We compared the biofilm formation process by fluorescence microscope observation of LTA D-alanylation blocking strain with that of the wildtype strain. Auto-aggregation, cell surface charge, and polysaccharide production assays were performed to investigate the related mechanisms. pH drop assay and glycolysis pH drop-down analysis were carried out to evaluate the acidogenesis capacity of S. mutans after LTA D-alanylation blocking. To identify the biofilm formation and adhesive-related genes expressions of S. mutans mutant, qRT-PCR was performed. RESULTS After blocking off the D-alanylation of LTA, S. mutans could not form the three-dimensional structural biofilm, in which cells were scattered on the substratum as small clusters. The auto-aggregation was prompted due to the mutant strain cell morphology change (*p < 0.05). Furthermore, more negative charges were found on the mutant strain cells surfaces and fewer water-insoluble glucans were produced in mutant biofilm (*p < 0.05). The adhesion capacity of the S. mutans biofilm was impaired after LTA D-alanylation blocking (*p < 0.05). Biofilm formation and adhesive-related genes expressions decreased (*p < 0.05), especially at the early stages of biofilm formation. S. mutans mutant strains exhibited suppressed acidogenesis because its glycolytic activity was impaired. CONCLUSION The results of this study suggest that blocking of LTA D-alanylation disrupts normal biofilm formation in S. mutans predominantly if not entirely by altering intercellular auto-aggregation, cell adhesion, and extracellular matrix formation. Moreover, our study results suggest that the LTA D-alanylation plays an important role in S. mutans acidogenesis by altering glycolytic activity. These findings add to the knowledge about mechanisms underlying biofilm formation and acid tolerance in S. mutans.
Collapse
Affiliation(s)
- Minjing Wu
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China; Stomatological Hospital, Southern Medical University, Guangzhou, China.
| | - Shan Huang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China.
| | - Jingyun Du
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Yijun Li
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China
| | - Shan Jiang
- Southern Medical University, Shenzhen Stomatology Hospital (Pingshan), China
| | - Ling Zhan
- Division of Pediatric Dentistry, Department of Orofacial Sciences, Department of Preventive and Restorative Dental Sciences, University of California, San Francisco, USA.
| | - Xiaojing Huang
- Fujian Key Laboratory of Oral Diseases & Fujian Provincial Engineering Research Center of Oral Biomaterial & Stomatological Key Lab of Fujian College and University, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, China.
| |
Collapse
|
8
|
Yan K, Stanley M, Kowalski B, Raimi OG, Ferenbach AT, Wei P, Fang W, van Aalten DMF. Genetic validation of Aspergillus fumigatus phosphoglucomutase as a viable therapeutic target in invasive aspergillosis. J Biol Chem 2022; 298:102003. [PMID: 35504355 PMCID: PMC9168620 DOI: 10.1016/j.jbc.2022.102003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Revised: 04/27/2022] [Accepted: 04/28/2022] [Indexed: 02/09/2023] Open
Abstract
Aspergillus fumigatus is the causative agent of invasive aspergillosis, an infection with mortality rates of up to 50%. The glucan-rich cell wall of A. fumigatus is a protective structure that is absent from human cells and is a potential target for antifungal treatments. Glucan is synthesized from the donor uridine diphosphate glucose, with the conversion of glucose-6-phosphate to glucose-1-phosphate by the enzyme phosphoglucomutase (PGM) representing a key step in its biosynthesis. Here, we explore the possibility of selectively targeting A. fumigatus PGM (AfPGM) as an antifungal treatment strategy. Using a promoter replacement strategy, we constructed a conditional pgm mutant and revealed that pgm is required for A. fumigatus growth and cell wall integrity. In addition, using a fragment screen, we identified the thiol-reactive compound isothiazolone fragment of PGM as targeting a cysteine residue not conserved in the human ortholog. Furthermore, through scaffold exploration, we synthesized a para-aryl derivative (ISFP10) and demonstrated that it inhibits AfPGM with an IC50 of 2 μM and exhibits 50-fold selectivity over the human enzyme. Taken together, our data provide genetic validation of PGM as a therapeutic target and suggest new avenues for inhibiting AfPGM using covalent inhibitors that could serve as tools for chemical validation.
Collapse
Affiliation(s)
- Kaizhou Yan
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Mathew Stanley
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Bartosz Kowalski
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Olawale G Raimi
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Andrew T Ferenbach
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Pingzhen Wei
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Wenxia Fang
- National Engineering Research Center for Non-Food Biorefinery, Guangxi Academy of Sciences, Nanning, China
| | - Daan M F van Aalten
- Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom.
| |
Collapse
|
9
|
Colussi S, Pastorino P, Mugetti D, Antuofermo E, Sciuto S, Esposito G, Polinas M, Tomasoni M, Burrai GP, Fernández-Garayzábal JF, Acutis PL, Pedron C, Prearo M. Isolation and Genetic Characterization of Streptococcus iniae Virulence Factors in Adriatic Sturgeon ( Acipenser naccarii). Microorganisms 2022; 10:883. [PMID: 35630328 PMCID: PMC9144172 DOI: 10.3390/microorganisms10050883] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/15/2022] [Accepted: 04/20/2022] [Indexed: 02/04/2023] Open
Abstract
The first case of infection of Streptococcus iniae in Adriatic sturgeon (Acipenser naccarii) was recently reported in a raceway system located in Northern Italy. A second episode of infection in sturgeons with absence of mortality and evident clinical signs, was registered in November 2020 in the same farm and is reported in this study. Histopathological changes observed in infected organs are described. The strains isolated in the two episodes were compared using molecular analysis based on PCR, phylogeny and virulence factors analysis. Not all the major virulence factors were detected for the two strains; in particular the strains 78697, isolated in November, lacks cpsD, compared to the strains 64844, isolated in September. Moreover, genetic variations were reported for lctO and pmg genes. These findings let us hypothesize a different virulence of the strains in accordance with clinical findings related to the sturgeons.
Collapse
Affiliation(s)
- Silvia Colussi
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Paolo Pastorino
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Davide Mugetti
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Elisabetta Antuofermo
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | - Simona Sciuto
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Giuseppe Esposito
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Marta Polinas
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | - Mattia Tomasoni
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | - Giovanni Pietro Burrai
- Department of Veterinary Medicine, University of Sassari, 07100 Sassari, Italy; (E.A.); (M.P.); (G.P.B.)
| | | | - Pier Luigi Acutis
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| | | | - Marino Prearo
- The Veterinary Medical Research Institute for Piemonte, Liguria and Valle d’Aosta, 10154 Turin, Italy; (S.C.); (S.S.); (G.E.); (M.T.); (P.L.A.); (M.P.)
| |
Collapse
|
10
|
Heckman TI, Shahin K, Henderson EE, Griffin MJ, Soto E. Development and efficacy of Streptococcus iniae live-attenuated vaccines in Nile tilapia, Oreochromis niloticus. FISH & SHELLFISH IMMUNOLOGY 2022; 121:152-162. [PMID: 34965443 DOI: 10.1016/j.fsi.2021.12.043] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 11/30/2021] [Accepted: 12/23/2021] [Indexed: 06/14/2023]
Abstract
Streptococcus iniae is a re-emerging bacterial pathogen in freshwater and marine aquaculture worldwide. There are no commercial vaccines available for S. iniae in the United States, and autogenous vaccines are restricted to inactivated whole-cell preparations with limited protection against heterogenous strains. Live-attenuated vaccines (LAV) represent an advantageous alternative to these bacterins, as they induce robust cellular and humoral immunity, and may provide longer lasting protection through less stressful routes of administration. We investigated whether accumulation of mutations in S. iniae by serial passage in the presence of rifampin can generate immunogenic LAV conferring protection against challenge with heterologous wild-type (WT) S. iniae strains in Nile tilapia (Oreochromis niloticus). Three lineages of rifampin-resistant S. iniae strains were generated from three genetically distinct parent strains (n = 9) by multiple passages in increments of Rifamycin SV sodium salt. Growth in liquid media, extent of capsulation, antimicrobial susceptibility, survival in Nile tilapia whole blood, and cytotoxicity in an O. mossambicus endothelial cell line were compared between the passaged and WT strains. Nile tilapia challenges were used to assess strain virulence, generation of anti-S. iniae IgM, and the protection conferred by LAV candidates against virulent S. iniae. Rifampin-resistant strains demonstrated changes in growth rate and cytotoxicity in endothelial cells, as well as significant reductions in whole blood survival (p < 0.05). Selected strains also showed attenuated virulence in the Nile tilapia challenge model, and anti-S. iniae IgM generated against these strains demonstrated cross-reactivity against heterologous bacteria. Immunization by intracoelomic injection induced protection against a virulent WT strain of S. iniae, with relative percent survival up to 95.05%.
Collapse
Affiliation(s)
- Taylor I Heckman
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA
| | - Khalid Shahin
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA; Aquatic Animals Diseases Laboratory, Aquaculture Division, National Institute of Oceanography and Fisheries, P.O. Box 43511, Suez, Egypt
| | - Eileen E Henderson
- California Animal Health and Food Safety Lab, School of Veterinary Medicine, University of California, Davis, CA, 92408, USA
| | - Matt J Griffin
- Department of Pathobiology and Population Medicine, College of Veterinary Medicine, Mississippi State University, Stoneville, MS, 39762, USA
| | - Esteban Soto
- Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA, 95616, USA.
| |
Collapse
|
11
|
Huang S, Wu M, Li Y, Du J, Chen S, Jiang S, Huang X, Zhan L. The dlt operon contributes to the resistance to chlorhexidine in Streptococcus mutans. Int J Antimicrob Agents 2022; 59:106540. [DOI: 10.1016/j.ijantimicag.2022.106540] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Revised: 01/01/2022] [Accepted: 01/19/2022] [Indexed: 11/05/2022]
|
12
|
Zabidi A, Yusoff FM, Amin N, Yaminudin NJM, Puvanasundram P, Karim MMA. Effects of Probiotics on Growth, Survival, Water Quality and Disease Resistance of Red Hybrid Tilapia ( Oreochromis spp.) Fingerlings in a Biofloc System. Animals (Basel) 2021; 11:ani11123514. [PMID: 34944289 PMCID: PMC8697905 DOI: 10.3390/ani11123514] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2021] [Revised: 11/22/2021] [Accepted: 11/24/2021] [Indexed: 11/23/2022] Open
Abstract
Simple Summary Streptococcosis, a warm-water pathogenic bacteria, has greatly affected red hybrid tilapia production in Malaysia over the years, causing mass mortality in various culture systems. Probiotics have been used to treat and prevent bacterial diseases, including streptococcosis, yet they require constant application to ensure that their concentration is adequate. Incorporating probiotics in a biofloc system may reduce this issue as the effective microorganism may further flourish and be utilized by the fish. The objectives of this study were to evaluate the influence of probiotic addition on the growth performance and water quality of red hybrid tilapia. From the study, it was observed that a probiotic mix was able to inhibit Streptococcus spp., improve red hybrid tilapia performance and disease resistance against streptococcosis. Providing a beneficial mix of probiotics can effectively improve biofloc culture in red hybrid tilapia culture. Abstract Biofloc technology has shown positive effects in aquaculture, especially on the growth performance of cultured animals. The aims of this study were to evaluate the effects of adding different probiotic strains in a biofloc system on the growth performance and disease resistance of red hybrid tilapia (Oreochromis spp.). Three different probiotics (Lysinibacillus fusiformis SPS11, Bacillus amyloliquefaciens L9, and Enterococcus hirae LAB3), commercial probiotics (MG1) and a mixed probiotics (MP) combining all three strains were used in this study. The in vitro assay results showed that the mixed probiotic (MP) was able to inhibit the growth of Streptococcus agalactiae and Streptococcus iniae significantly compared to the single and commercial probiotic. The efficacy of MP was further tested in in vivo tilapia culture challenged with S. agalactiae. The best specific growth rate (3.73 ± 0.23% day−1) and feed conversion ratio (0.76 ± 0.04) were recorded in the group of biofloc with addition of MP. After being challenged with S. agalactiae, the group of biofloc with MP had significantly higher survival (83 ± 1.43%) compared to the other groups. Furthermore, the nitrogen concentration (NO2-N and NH4-N) was significantly lower in all the biofloc groups compared to the control. Hence, the addition of probiotics was able to provide beneficial effects to red hybrid tilapia culture in the biofloc system.
Collapse
Affiliation(s)
- Aimi Zabidi
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.); (F.M.Y.); (N.A.); (N.J.M.Y.)
| | - Fatimah Md Yusoff
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.); (F.M.Y.); (N.A.); (N.J.M.Y.)
- Laboratory of Sustainable Aquaculture, International Institute of Aquaculture and Aquatic Sciences, Universiti Putra Malaysia, Port Dickson 71050, Malaysia
| | - Nurul Amin
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.); (F.M.Y.); (N.A.); (N.J.M.Y.)
- Laboratory of Sustainable Aquaculture, International Institute of Aquaculture and Aquatic Sciences, Universiti Putra Malaysia, Port Dickson 71050, Malaysia
| | - Nur Jasmin Mohd Yaminudin
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.); (F.M.Y.); (N.A.); (N.J.M.Y.)
| | - Puvaneswari Puvanasundram
- Laboratory of Aquatic Animal Health and Therapeutics, Institute of Biosciences, Universiti Putra Malaysia, Serdang 43400, Malaysia;
| | - Murni Marlina Abd Karim
- Department of Aquaculture, Faculty of Agriculture, Universiti Putra Malaysia, Serdang 43400, Malaysia; (A.Z.); (F.M.Y.); (N.A.); (N.J.M.Y.)
- Laboratory of Sustainable Aquaculture, International Institute of Aquaculture and Aquatic Sciences, Universiti Putra Malaysia, Port Dickson 71050, Malaysia
- Correspondence: ; Tel.: +60-123-026-397
| |
Collapse
|
13
|
Rahman S, Das AK. Integrated Multi-omics, Virtual Screening and Molecular Docking Analysis of Methicillin-Resistant Staphylococcus aureus USA300 for the Identification of Potential Therapeutic Targets: An In-Silico Approach. Int J Pept Res Ther 2021; 27:2735-2755. [PMID: 34548853 PMCID: PMC8446483 DOI: 10.1007/s10989-021-10287-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/10/2021] [Indexed: 11/28/2022]
Abstract
Staphylococcus aureus infection is a leading cause of mortality and morbidity in community, hospital and live-stock sectors, especially with the widespread emergence of methicillin-resistant S. aureus (MRSA) strains. To identify new drug molecules to treat MRSA patients, we have undertaken to search essential proteins that are indispensable for their survival but non-homologous to human host proteins. The current study utilizes a subtractive genome and proteome approach to screen the possible therapeutic targets against S. aureus USA300. Bacterial essential genes are obtained from the DEG database and are compared to avoid cross-reactivity with human host genes. In silico analysis shows 198 proteins that may be considered as therapeutic candidates. Depending on their sub-cellular localization, proteins are grouped as either vaccine or drug targets or both. Extracellular proteins such as cell division proteins (Q2FZ91, Q2FZ95), penicillin-binding proteins (Q2FZ94, Q2FYI0) of the bacterial cell wall, phosphoglucomutase (Q2FE11) and lipoteichoic acid synthase (Q2FIS2) are considered as vaccine targets, and their epitopes have been mapped. Altogether, 53 drug targets are identified, which have shown similarity with the drug targets available in the DrugBank database. Predicted drug targets belong to the common metabolic pathways of MRSA, such as fatty acid biosynthesis, folate biosynthesis, peptidoglycan biosynthesis, ribosome, etc. Protein-protein interaction analysis emphasizing peptidoglycan biosynthesis reveals the connection between penicillin-binding proteins, mur-family proteins and FemXAB proteins. In this study, staphylococcal FemA protein (P0A0A5) is subjected to structure-based virtual screening for the drug repurposing approach. There are 20 residues missing in the crystal structure of FemA, and 12 of these residues are located at the catalytic site. The missing residues are modelled, and stereochemistry is checked. FDA approved drugs available in the DrugBank database have been used in virtual screening with FemA in search of potential repurposed molecules. This approach provides us with 10 drugs that may be used in the treatment of methicillin-resistant staphylococcal mediated diseases. AutoDock 4.2 is used for in silico screening and shows a comparable inhibition constant (Ki) for all 10 FDA-approved drugs towards FemA. Most of these drugs are used in the treatment of various cancers, migraines and leukaemia. Protein-drug interaction analysis shows that the drugs mostly interact with hydrophobic residues of FemA. Moreover, Tyr328 and Lys383 contribute largely to hydrogen bondings during interactions. All interacting amino acids that bind to the drugs are part of the active site cavity of FemA. Supplementary Information The online version contains supplementary material available at 10.1007/s10989-021-10287-9.
Collapse
Affiliation(s)
- Shakilur Rahman
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
| | - Amit Kumar Das
- Department of Biotechnology, Indian Institute of Technology Kharagpur, Kharagpur, West Bengal 721302 India
| |
Collapse
|
14
|
Serek P, Lewandowski Ł, Dudek B, Pietkiewicz J, Jermakow K, Kapczyńska K, Krzyżewska E, Bednarz-Misa I. Klebsiella pneumoniae enolase-like membrane protein interacts with human plasminogen. Int J Med Microbiol 2021; 311:151518. [PMID: 34237624 DOI: 10.1016/j.ijmm.2021.151518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 05/14/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022] Open
Abstract
Many models assessing the risk of sepsis utilize the knowledge of the constituents of the plasminogen system, as it is proven that some species of bacteria can activate plasminogen, as a result of interactions with bacterial outer membrane proteins. However, much is yet to be discovered about this interaction since there is little information regarding some bacterial species. This study is aimed to check if Klebsiella pneumoniae, one of the major factors of nosocomial pneumonia and a factor for severe sepsis, has the ability to bind to human plasminogen. The strain used in this study, PCM 2713, acted as a typical representative of the species. With use of various methods, including: electron microscopy, 2-dimensional electrophoresis, immunoblotting and peptide fragmentation fingerprinting, it is shown that Klebsiella pneumoniae binds to human plasminogen, among others, due to plasminogen-bacterial enolase-like protein interaction, occurring on the outer membrane of the bacterium. Moreover, the study reveals, that other proteins, such as: phosphoglucomutase, and phosphoenolpyruvate carboxykinase act as putative plasminogen-binding factors. These information may virtually act as a foundation for future studies investigating: the: pathogenicity of Klebsiella pneumoniae and means for prevention from the outcomes of Klebsiella-derived sepsis.
Collapse
Affiliation(s)
- Paweł Serek
- Department of Biochemistry and Immunochemistry, Wroclaw Medical University, Chałubińskiego 10, 50-368, Wroclaw, Poland
| | - Łukasz Lewandowski
- Department of Biochemistry and Immunochemistry, Wroclaw Medical University, Chałubińskiego 10, 50-368, Wroclaw, Poland
| | - Bartłomiej Dudek
- Department of Microbiology, Institute of Genetics and Microbiology, University of Wrocław, Przybyszewskiego 63-77, 51-148, Wroclaw, Poland
| | - Jadwiga Pietkiewicz
- Department of Biochemistry and Immunochemistry, Wroclaw Medical University, Chałubińskiego 10, 50-368, Wroclaw, Poland
| | - Katarzyna Jermakow
- Department of Microbiology, Faculty of Medicine, Wroclaw Medical University, Chałubińskiego 4, 50-368, Wrocław, Poland
| | - Katarzyna Kapczyńska
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114, Wrocław, Poland
| | - Eva Krzyżewska
- Department of Immunology of Infectious Diseases, Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, 53-114, Wrocław, Poland
| | - Iwona Bednarz-Misa
- Department of Biochemistry and Immunochemistry, Wroclaw Medical University, Chałubińskiego 10, 50-368, Wroclaw, Poland.
| |
Collapse
|
15
|
Yang DX, Yang H, Cao YC, Jiang M, Zheng J, Peng B. Succinate Promotes Phagocytosis of Monocytes/Macrophages in Teleost Fish. Front Mol Biosci 2021; 8:644957. [PMID: 33937328 PMCID: PMC8082191 DOI: 10.3389/fmolb.2021.644957] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 03/26/2021] [Indexed: 12/14/2022] Open
Abstract
Development of immunity-based strategy to manage bacterial infection is urgently needed in aquaculture due to the widespread of antibiotic-resistant bacteria. Phagocytosis serves as the first line defense in innate immunity that engulfs bacteria and restricts their proliferations and invasions. However, the mechanism underlying the regulation of phagocytosis is not fully elucidated and the way to boost phagocytosis is not yet explored. In this manuscript, we profiled the metabolomes of monocytes/macrophages isolated from Nile tilapia, prior and after phagocytosis on Vibrio alginolyticus. Monocytes/macrophages showed a metabolic shift following phagocytosis. Interestingly, succinate was accumulated after phagocytosis and was identified as a crucial biomarker to distinguish before and after phagocytosis. Exogenous succinate increased the phagocytotic rate of monocytes/macrophages in a dose-dependent manner. This effect was dependent on the TCA cycle as the inhibitor of malonate that targets succinate dehydrogenase abrogated the effect. Meanwhile, exogenous succinate regulated the expression of genes associated with innate immune and phagocytosis. In addition, succinate-potentiated phagocytosis was applicable to both gram-negative and -positive cells, including V. alginolyticus, Edwardsiella tarda, Streptococcus agalactiae, and Streptococcus iniae. Our study shed light on the understanding of how modulation on host's metabolism regulates immune response, and this can be a potent therapeutic approach to control bacterial infections in aquaculture.
Collapse
Affiliation(s)
- Dai-Xiao Yang
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Hao Yang
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Yun-Chao Cao
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Ming Jiang
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| | - Jun Zheng
- Faculty of Health Sciences, University of Macau, Macau, China
| | - Bo Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Biocontrol, Guangdong Key Laboratory of Pharmaceutical Functional Genes, School of Life Sciences, Sun Yat-sen University, Guangzhou, China.,Laboratory for Marine Biology and Biotechnology, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China.,Southern Marine Science and Engineering Guangdong Laboratory, Zhuhai, China
| |
Collapse
|
16
|
Heckman TI, Griffin MJ, Camus AC, LaFrentz BR, Morick D, Smirnov R, Ofek T, Soto E. Multilocus sequence analysis of diverse Streptococcus iniae isolates indicates an underlying genetic basis for phenotypic heterogeneity. DISEASES OF AQUATIC ORGANISMS 2020; 141:53-69. [PMID: 32940251 DOI: 10.3354/dao03521] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Streptococcus iniae is a Gram-positive, opportunistically zoonotic bacterium infective to a wide variety of farmed and wild fish species worldwide. Outbreaks in wild fish can have detrimental environmental and cultural impacts, and mortality events in aquaculture can result in significant economic losses. As an emerging or re-emerging pathogen of global significance, understanding the coalescing factors contributing to piscine streptococcosis is crucial for developing strategies to control infections. Intraspecific antigenic and genetic variability of S. iniae has made development of autogenous vaccines a challenge, particularly where the diversity of locally endemic S. iniae strains is unknown. This study genetically and phenotypically characterized 11 S. iniae isolates from diseased wild and farmed fish from North America, Central America, and the Caribbean. A multilocus sequence analysis (MLSA) scheme was developed to phylogenetically compare these isolates to 84 other strains of Streptococcus spp. relevant to aquaculture. MLSA generated phylogenies comparable to established genotyping methods, and isolates formed distinct clades related to phenotype and host species. The endothelial Oreochromis mossambicus bulbus arteriosus cell line and whole blood from rainbow trout Oncorhynchus mykiss, Nile tilapia Oreochromis niloticus, and white sturgeon Acipenser transmontanus were used to investigate the persistence and virulence of the 11 isolates using in vitro assays. In vivo challenges using an O. niloticus model were used to evaluate virulence by the intragastric route of infection. Isolates showed significant differences (p < 0.05) in virulence and persistence, with some correlation to genogroup, establishing a basis for further work uncovering genetic factors leading to increased pathogenicity.
Collapse
Affiliation(s)
- Taylor I Heckman
- Aquatic Animal Health Laboratory, Department of Medicine & Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA
| | | | | | | | | | | | | | | |
Collapse
|
17
|
|
18
|
Zhang D, Gao Y, Li Q, Ke X, Liu Z, Lu M, Shi C. An effective live attenuated vaccine against Streptococcus agalactiae infection in farmed Nile tilapia (Oreochromis niloticus). FISH & SHELLFISH IMMUNOLOGY 2020; 98:853-859. [PMID: 31751658 DOI: 10.1016/j.fsi.2019.11.044] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/12/2019] [Revised: 10/19/2019] [Accepted: 11/18/2019] [Indexed: 06/10/2023]
Abstract
Streptococcus agalactiae is an important pathogen associated with various aquatic animals, especially tilapia. Streptococcosis has greatly limited the healthy development of tilapia aquaculture in recent times. The development of novel effective vaccines is important for the prevention and control of streptococcosis in fish. We previously constructed a non-encapsulated S. agalactiae strain △cps by the in-frame deletion method. Here, we evaluated whether this mutant △cps is safe for tilapia and suitable for protection against streptococcosis. We observed that the △cps strain was non-pathogenic to tilapia, and there was no reversion of virulence when it was passaged in tilapia. Moreover, the △cps strain survived for at least 11 d in the main immune organs of tilapia. The tilapia vaccinated via intraperitoneal (IP) injection with △cps strain induced a high antibody titer, and the IgM antibody levels were significantly higher in the vaccinated group than in the control group. The vaccination protected tilapia against the S. agalactiae challenge with a relative percent survival of 90.47%. In addition, tilapia immunized with the △cps strain showed significantly higher expression level of IFN-γ, IL-1β, MyD88, IgM, and MHC-Iα in the head kidney than those in the control during the entire observation period. The expression of MHC-IIβ was inhibited during 1-7 d of immunization. These results revealed that the △cps strain is able to induce humoral and cell-mediated immune response in tilapia. Therefore, the strain △cps has a broad application prospect as a target for attenuation in vaccine development.
Collapse
Affiliation(s)
- Defeng Zhang
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Yanxia Gao
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Qingyong Li
- Fisheries Research and Extension Center of Huizhou, Huizhou, 516002, China
| | - Xiaoli Ke
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Zhigang Liu
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| | - Maixin Lu
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China.
| | - Cunbin Shi
- Key Laboratory of Fishery Drug Development, Ministry of Agriculture and Rural Affairs, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China; Key Laboratory of Aquatic Animal Immune Technology, Guangdong Province, Pearl River Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou, 510380, China
| |
Collapse
|
19
|
Review on Immersion Vaccines for Fish: An Update 2019. Microorganisms 2019; 7:microorganisms7120627. [PMID: 31795391 PMCID: PMC6955699 DOI: 10.3390/microorganisms7120627] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 11/25/2019] [Accepted: 11/26/2019] [Indexed: 01/11/2023] Open
Abstract
Immersion vaccines are used for a variety of aquacultured fish to protect against infectious diseases caused by bacteria and viruses. During immersion vaccination the antigens are taken up by the skin, gills or gut and processed by the immune system, where the resulting response may lead to protection. The lack of classical secondary responses following repeated immersion vaccination may partly be explained by the limited uptake of antigens by immersion compared to injection. Administration of vaccines depends on the size of the fish. In most cases, immersion vaccination is inferior to injection vaccination with regard to achieved protection. However, injection is problematic in small fish, and fry as small as 0.5 gram may be immersion vaccinated when they are considered adaptively immunocompetent. Inactivated vaccines are, in many cases, weakly immunogenic, resulting in low protection after immersion vaccination. Therefore, during recent years, several studies have focused on different ways to augment the efficacy of these vaccines. Examples are booster vaccination, administration of immunostimulants/adjuvants, pretreatment with low frequency ultrasound, use of live attenuated and DNA vaccines, preincubation in hyperosmotic solutions, percutaneous application of a multiple puncture instrument and application of more suitable inactivation chemicals. Electrostatic coating with positively charged chitosan to obtain mucoadhesive vaccines and a more efficient delivery of inactivated vaccines has also been successful.
Collapse
|
20
|
Ma J, Bruce TJ, Jones EM, Cain KD. A Review of Fish Vaccine Development Strategies: Conventional Methods and Modern Biotechnological Approaches. Microorganisms 2019; 7:E569. [PMID: 31744151 PMCID: PMC6920890 DOI: 10.3390/microorganisms7110569] [Citation(s) in RCA: 131] [Impact Index Per Article: 26.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2019] [Revised: 11/10/2019] [Accepted: 11/14/2019] [Indexed: 01/09/2023] Open
Abstract
Fish immunization has been carried out for over 50 years and is generally accepted as an effective method for preventing a wide range of bacterial and viral diseases. Vaccination efforts contribute to environmental, social, and economic sustainability in global aquaculture. Most licensed fish vaccines have traditionally been inactivated microorganisms that were formulated with adjuvants and delivered through immersion or injection routes. Live vaccines are more efficacious, as they mimic natural pathogen infection and generate a strong antibody response, thus having a greater potential to be administered via oral or immersion routes. Modern vaccine technology has targeted specific pathogen components, and vaccines developed using such approaches may include subunit, or recombinant, DNA/RNA particle vaccines. These advanced technologies have been developed globally and appear to induce greater levels of immunity than traditional fish vaccines. Advanced technologies have shown great promise for the future of aquaculture vaccines and will provide health benefits and enhanced economic potential for producers. This review describes the use of conventional aquaculture vaccines and provides an overview of current molecular approaches and strategies that are promising for new aquaculture vaccine development.
Collapse
Affiliation(s)
- Jie Ma
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Timothy J. Bruce
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Evan M. Jones
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| | - Kenneth D. Cain
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, ID 83844, USA (T.J.B.); (E.M.J.)
- Aquaculture Research Institute, University of Idaho, Moscow, ID 83844, USA
| |
Collapse
|
21
|
Abdi M, Mirkalantari S, Amirmozafari N. Bacterial resistance to antimicrobial peptides. J Pept Sci 2019; 25:e3210. [DOI: 10.1002/psc.3210] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 07/04/2019] [Accepted: 07/21/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Milad Abdi
- Student Research Committee, Faculty of MedicineIran University of Medical Sciences Tehran Iran
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
| | - Shiva Mirkalantari
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
| | - Nour Amirmozafari
- Department of Microbiology, Faculty of MedicineIran University of Medical Sciences Tehran Iran
| |
Collapse
|
22
|
Nilsson M, Givskov M, Twetman S, Tolker-Nielsen T. Inactivation of the pgmA Gene in Streptococcus mutans Significantly Decreases Biofilm-Associated Antimicrobial Tolerance. Microorganisms 2019; 7:microorganisms7090310. [PMID: 31484288 PMCID: PMC6780209 DOI: 10.3390/microorganisms7090310] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2019] [Revised: 08/29/2019] [Accepted: 08/30/2019] [Indexed: 11/16/2022] Open
Abstract
Screening of a Streptococcus mutans mutant library indicated that pgmA mutants displayed a reduced biofilm-associated tolerance toward gentamicin. The biofilms formed by the S. mutanspgmA mutant also displayed decreased tolerance towards linezolid and vancomycin compared to wild-type biofilms. On the contrary, the resistance of planktonic S. mutanspgmA cells to gentamycin, linezolid, and vancomycin was more similar to wild-type levels. Investigations of biofilms grown in microtiter trays and on submerged glass slides showed that pgmA mutants formed roughly the same amount of biofilm as the wild type, indicating that the reduced antimicrobial tolerance of these mutants is not due to diminished biofilm formation. The pgmA gene product is known to be involved in the synthesis of precursors for cell wall components such as teichoic acids and membrane glycolipids. Accordingly, the S. mutanspgmA mutant showed increased sensitivity to Congo Red, indicating that it has impaired cell wall integrity. A changed cell wall composition of the S. mutanspgmA mutant may play a role in the increased sensitivity of S. mutanspgmA biofilms toward antibiotics.
Collapse
Affiliation(s)
- Martin Nilsson
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Michael Givskov
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
- Singapore Centre for Environmental Life Sciences Engineering, Nanyang Technological University, Singapore 637551, Singapore
| | - Svante Twetman
- Department of Odontology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark
| | - Tim Tolker-Nielsen
- Costerton Biofilm Center, Department of Immunology and Microbiology, Faculty of Health and Medical Sciences, University of Copenhagen, DK-2200 Copenhagen, Denmark.
| |
Collapse
|
23
|
Sheng X, Gao J, Liu H, Tang X, Xing J, Zhan W. Recombinant phosphoglucomutase and CAMP factor as potential subunit vaccine antigens induced high protection against Streptococcus iniae infection in flounder (Paralichthys olivaceus). J Appl Microbiol 2018; 125:997-1007. [PMID: 29877008 DOI: 10.1111/jam.13948] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/17/2018] [Accepted: 06/01/2018] [Indexed: 12/14/2022]
Abstract
AIMS The aim of this study was to screen vaccine candidates from virulence factors of Streptococcus iniae in flounder model. METHODS AND RESULTS The immunogenicity of recombinant phosphoglucomutase (rPGM) and rCAMP factor was confirmed by Western blot. The percentage of surface membrane immunoglobulin-positive (sIg+ ) lymphocytes in peripheral blood leucocytes, the specific and total serum IgM and the activity of acid phosphatase (ACP) and peroxidase (POD) in flounder were determined with flow cytometry, ELISA and commercial enzyme activity kits, respectively, after intraperitoneal immunization with rPGM and rCAMP factor. The results showed that rPGM and rCAMP factor could induce significant rise in sIg+ lymphocytes, specific serum IgM and activities of ACP and POD. Additionally, the relative percent survival rate of the vaccinated flounder was 64 and 54% in challenge experiment using S. iniae, respectively. These results indicated that rPGM and rCAMP factor could evoke humoural and innate immune response in flounder and provide high-efficiency immunoprotection against S. iniae infection. CONCLUSIONS Phosphoglucomutase (PGM) and CAMP factor were promising vaccine candidates against S. iniae in flounder. SIGNIFICANCE AND IMPACT OF THE STUDY Phosphoglucomutase and CAMP factor have the potential to be vaccine candidates, which provide important information for us to develop the effective subunit vaccines, especially the multivaccine, against S .iniae in aquaculture.
Collapse
Affiliation(s)
- X Sheng
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China
| | - J Gao
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China
| | - H Liu
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China
| | - X Tang
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China
| | - J Xing
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China
| | - W Zhan
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, China.,Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, China
| |
Collapse
|
24
|
Sheng X, Liu M, Liu H, Tang X, Xing J, Zhan W. Identification of immunogenic proteins and evaluation of recombinant PDHA1 and GAPDH as potential vaccine candidates against Streptococcus iniae infection in flounder (Paralichthys olivaceus). PLoS One 2018; 13:e0195450. [PMID: 29847601 PMCID: PMC5976140 DOI: 10.1371/journal.pone.0195450] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2018] [Accepted: 03/22/2018] [Indexed: 11/30/2022] Open
Abstract
Streptococcus iniae is a major Gram-positive pathogen that causes invasive disease in fish worldwide. In this study, in order to identify immunogenic proteins for developing highly effective vaccine against S. iniae, whole-cell lysate proteins of S. iniae were analyzed by western blotting using flounder anti-S. iniae antibodies, and two positive protein bands of molecular weight 37 kDa and 40 kDa were screened, which were identified as pyruvate dehydrogenase E1 subunit alpha (PDHA1), BMP family ABC transporter substrate-binding protein (BMP) and L-lactate dehydrogenase (LDH), as well as ornithine carbamoyltransferase (OCT), lactate oxidas (LOx) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) by mass spectrometry. Subsequently, the six recombinant proteins were produced and used to immunize healthy flounder, and the relative percent survival (RPS) value was 72.73%, 27.27%, 36.36%, 9.09%, 36.36% and 63.64% respectively after intraperitoneal challenge with live S. iniae, revealing that rPDHA1 and rGAPDH produced higher relative percent survival than formalin-killed S. iniae (36.36%). To further investigate the protective efficacy of rPDHA1 and rGAPDH, the proliferation of surface membrane immunoglobulin-positive (sIg+) lymphocytes in peripheral blood leucocytes, the total serum IgM, specific IgM against S. iniae and RPS were detected. The results showed that rPDHA1, rGAPDH and formalin-killed S. iniae significantly induced the proliferation of sIg+ lymphocytes, the production of total serum IgM and specific IgM as compared with the control group, and rGAPDH and rPDHA1 provide higher RPS (62.5% and 75%, respectively) again. These results demonstrated that rPDHA1 and rGAPDH are promising vaccine candidates against S. iniae infection in flounder.
Collapse
Affiliation(s)
- Xiuzhen Sheng
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
| | - Min Liu
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
| | - Haibo Liu
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
| | - Xiaoqian Tang
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
| | - Jing Xing
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
| | - Wenbin Zhan
- Laboratory of Pathology and Immunology of Aquatic Animals, KLMME, Ocean University of China, Qingdao, P. R. China
- Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Qingdao, P. R. China
| |
Collapse
|
25
|
Aziz MA, Ushirokita R, Azuma Y. Identification of Chlamydia pneumoniae candidate genes that interact with human apoptotic factor caspase-9. J GEN APPL MICROBIOL 2018; 64:253-257. [PMID: 29760350 DOI: 10.2323/jgam.2017.12.008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Chlamydia pneumoniae is an obligate intracellular pathogen responsible for respiratory diseases, including pneumonia and bronchitis, and is highly involved in chronic diseases, including atherosclerosis, asthma, and Alzheimer's disease. We previously showed that the host apoptotic factor caspase-9 played a crucial role for chlamydial multiplication and host apoptosis inhibition by chlamydial infection. To identify chlamydial genes interacting with human caspase-9, yeast two-hybrid screening was performed and 5 chlamydial genes, including Cpj0838 and pmpG were isolated from the C. pneumoniae genomic library. Pull-down experiments showed that caspase-9 physically bound to the Cpj0838 product and chlamydial cells, which contain PmpG proteins. This study could provide a clue to understanding host-Chlamydia interactions, especially the apoptosis repression by Chlamydia infection.
Collapse
Affiliation(s)
- Md Abdul Aziz
- Graduate School of Biology-Oriented Science and Technology, Kindai University
| | - Rie Ushirokita
- Graduate School of Biology-Oriented Science and Technology, Kindai University
| | - Yoshinao Azuma
- Graduate School of Biology-Oriented Science and Technology, Kindai University
| |
Collapse
|
26
|
Kamal AHM, Fessler MB, Chowdhury SM. Comparative and network-based proteomic analysis of low dose ethanol- and lipopolysaccharide-induced macrophages. PLoS One 2018; 13:e0193104. [PMID: 29481576 PMCID: PMC5826526 DOI: 10.1371/journal.pone.0193104] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 02/05/2018] [Indexed: 12/24/2022] Open
Abstract
Macrophages are specialized phagocytes that play an essential role in inflammation, immunity, and tissue repair. Profiling the global proteomic response of macrophages to microbial molecules such as bacterial lipopolysaccharide is key to understanding fundamental mechanisms of inflammatory disease. Ethanol is a widely abused substance that has complex effects on inflammation. Reports have indicated that ethanol can activate or inhibit the lipopolysaccharide receptor, Toll-like Receptor 4, in different settings, with important consequences for liver and neurologic inflammation, but the underlying mechanisms are poorly understood. To profile the sequential effect of low dose ethanol and lipopolysaccharide on macrophages, a gel-free proteomic technique was applied to RAW 264.7 macrophages. Five hundred four differentially expressed proteins were identified and quantified with high confidence using ≥ 5 peptide spectral matches. Among these, 319 proteins were shared across all treatment conditions, and 69 proteins were exclusively identified in ethanol-treated or lipopolysaccharide-stimulated cells. The interactive impact of ethanol and lipopolysaccharide on the macrophage proteome was evaluated using bioinformatics tools, enabling identification of differentially responsive proteins, protein interaction networks, disease- and function-based networks, canonical pathways, and upstream regulators. Five candidate protein coding genes (PGM2, ISYNA1, PARP1, and PSAP) were further validated by qRT-PCR that mostly related to glucose metabolism and fatty acid synthesis pathways. Taken together, this study describes for the first time at a systems level the interaction between ethanol and lipopolysaccharide in the proteomic programming of macrophages, and offers new mechanistic insights into the biology that may underlie the impact of ethanol on infectious and inflammatory disease in humans.
Collapse
Affiliation(s)
- Abu Hena M. Kamal
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas, United States of America
| | - Michael B. Fessler
- Immunity, Inflammation and Disease Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina, United States of America
| | - Saiful M. Chowdhury
- Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, Texas, United States of America
| |
Collapse
|
27
|
Putative model based on iTRAQ proteomics for Spirulina morphogenesis mechanisms. J Proteomics 2018; 171:73-80. [DOI: 10.1016/j.jprot.2017.03.017] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 02/13/2017] [Accepted: 03/19/2017] [Indexed: 11/21/2022]
|
28
|
Identification of additional loci associated with antibody response to Mycobacterium avium ssp. Paratuberculosis in cattle by GSEA-SNP analysis. Mamm Genome 2017; 28:520-527. [PMID: 28864882 DOI: 10.1007/s00335-017-9714-7] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2017] [Accepted: 08/27/2017] [Indexed: 10/18/2022]
Abstract
Mycobacterium avium subsp. paratuberculosis: (MAP) causes a contagious chronic infection results in Johne's disease in a wide range of animal species, including cattle. Several genome-wide association studies (GWAS) have been carried out to identify loci putatively associated with MAP susceptibility by testing each marker separately and identifying SNPs that show a significant association with the phenotype, while SNP with modest effects are usually ignored. The objective of this study was to identify modest-effect genes associated with MAP susceptibility using a pathway-based approach. The Illumina BovineSNP50 BeadChip was used to genotype 966 Holstein cows, 483 positive and 483 negative for antibody response to MAP, data were then analyzed using novel SNP-based Gene Set Enrichment Analysis (GSEA-SNP) and validated with Adaptive Rank Truncated Product methodology. An allele-based test was carried out to estimate the statistical association for each marker with the phenotype, subsequently SNPs were mapped to the closest genes, considering for each gene the single variant with the highest value within a window of 50 kb, then pathway-statistics were tested using the GSEA-SNP method. The GO biological process "embryogenesis and morphogenesis" was most highly associated with antibody response to MAP. Within this pathway, five genes code for proteins which play a role in the immune defense relevant to response to bacterial infection. The immune response genes identified would not have been considered using a standard GWAS, thus demonstrating that the pathway approach can extend the interpretation of genome-wide association analyses and identify additional candidate genes for target traits.
Collapse
|
29
|
Stiers KM, Muenks AG, Beamer LJ. Biology, Mechanism, and Structure of Enzymes in the α-d-Phosphohexomutase Superfamily. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2017; 109:265-304. [PMID: 28683921 PMCID: PMC5802415 DOI: 10.1016/bs.apcsb.2017.04.005] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Enzymes in the α-d-phosphohexomutases superfamily catalyze the reversible conversion of phosphosugars, such as glucose 1-phosphate and glucose 6-phosphate. These reactions are fundamental to primary metabolism across the kingdoms of life and are required for a myriad of cellular processes, ranging from exopolysaccharide production to protein glycosylation. The subject of extensive mechanistic characterization during the latter half of the 20th century, these enzymes have recently benefitted from biophysical characterization, including X-ray crystallography, NMR, and hydrogen-deuterium exchange studies. This work has provided new insights into the unique catalytic mechanism of the superfamily, shed light on the molecular determinants of ligand recognition, and revealed the evolutionary conservation of conformational flexibility. Novel associations with inherited metabolic disease and the pathogenesis of bacterial infections have emerged, spurring renewed interest in the long-appreciated functional roles of these enzymes.
Collapse
Affiliation(s)
| | | | - Lesa J Beamer
- University of Missouri, Columbia, MO, United States.
| |
Collapse
|
30
|
Cai X, Wang B, Peng Y, Li Y, Lu Y, Huang Y, Jian J, Wu Z. Construction of a Streptococcus agalactiae phoB mutant and evaluation of its potential as an attenuated modified live vaccine in golden pompano, Trachinotus ovatus. FISH & SHELLFISH IMMUNOLOGY 2017; 63:405-416. [PMID: 27884809 DOI: 10.1016/j.fsi.2016.11.050] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/17/2016] [Accepted: 11/19/2016] [Indexed: 06/06/2023]
Abstract
Streptococcus agalactiae is a Gram-positive pathogen that can survive inside professional phagocytes and nonphagocytic cells to cause septicemia and meningoencephalitis in freshwater and marine fish. However, vaccines based on extracellular products (ECP) and formalin-killed whole S. agalactiae cells, as well as subunit vaccine are unable to protect fish from infection by variant serotypes S. agalactiae. The search for live attenuated vaccine with highly conserved and virulent-related genes is essential for producing a vaccine to help understand and control streptococcosis In this study, the phoB gene was cloned from pathogenic S. agalactiae TOS01 strain and the mutant strain SAΔphoB was constructed via allelic exchange mutagenesis. The results showed that the deduced amino acid of S. agalactiae TOS01 shares high similarities with other Streptococcus spp. and has high conserved response regulator receiver domain (REC) and DNA-binding effector domain of two-component system response regulators (Trans_reg_C). Cell adherence and invasion assays, challenge experiments and histopathological changes post-vaccination were performed and observed, the results showed that the mutant strain SAΔphoB has a lower adherence and invasion rate and less virulent than the wild type strain in golden pompano, and it doesn't induce clinical symptoms and obvious pathological changes in golden pompano, thereby indicating that the deletion of phoB affects the virulence and infectious capacity of S. agalactiae. Golden pompano vaccinated via intraperitoneal injection SAΔphoB had the relative percent survival value of 93.1% after challenge with TOS01, demonstrating its high potential as an effective attenuated live vaccine candidate. Real-time PCR assays showed that the SAΔphoB was able to enhance the expression of immune-related genes, including MHC-I, MyD88, IL-22 and IL-10 after vaccination, indicating that the SAΔphoB is able to induce humoral and cell-mediated immune response in golden pompano over a long period of time.
Collapse
Affiliation(s)
- Xiaohui Cai
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Bei Wang
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Yinhui Peng
- Guangxi Key Laboratory of Marine Biotechnology, Guangxi Institute of Oceanology, Beihai, 536000, China
| | - Yuan Li
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Yishan Lu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Yucong Huang
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China
| | - Jichang Jian
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China.
| | - Zaohe Wu
- College of Fishery, Guangdong Ocean University, Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Key Laboratory of Control for Disease of Aquatic Animals of Guangdong Higher Education Institutes, Zhanjiang, 524025, China.
| |
Collapse
|
31
|
Identification of some main Streptococcus iniae associated proteins: relationship. Vet Res Commun 2017; 41:85-95. [DOI: 10.1007/s11259-017-9675-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2016] [Accepted: 01/08/2017] [Indexed: 10/20/2022]
|
32
|
Abstract
Antimicrobial peptides (AMPs), also known as host defense peptides, are small naturally occurring microbicidal molecules produced by the host innate immune response that function as a first line of defense to kill pathogenic microorganisms by inducing deleterious cell membrane damage. AMPs also possess signaling and chemoattractant activities and can modulate the innate immune response to enhance protective immunity or suppress inflammation. Human pathogens have evolved defense molecules and strategies to counter and survive the AMPs released by host immune cells such as neutrophils and macrophages. Here, we review the various mechanisms used by human bacterial pathogens to resist AMP-mediated killing, including surface charge modification, active efflux, alteration of membrane fluidity, inactivation by proteolytic digestion, and entrapment by surface proteins and polysaccharides. Enhanced understanding of AMP resistance at the molecular level may offer insight into the mechanisms of bacterial pathogenesis and augment the discovery of novel therapeutic targets and drug design for the treatment of recalcitrant multidrug-resistant bacterial infections.
Collapse
|
33
|
The dlt genes play a role in antimicrobial tolerance of Streptococcus mutans biofilms. Int J Antimicrob Agents 2016; 48:298-304. [DOI: 10.1016/j.ijantimicag.2016.06.019] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 05/27/2016] [Accepted: 06/05/2016] [Indexed: 11/23/2022]
|
34
|
cpsJ gene of Streptococcus iniae is involved in capsular polysaccharide synthesis and virulence. Antonie van Leeuwenhoek 2016; 109:1483-1492. [PMID: 27535839 DOI: 10.1007/s10482-016-0750-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Accepted: 08/05/2016] [Indexed: 10/21/2022]
Abstract
The capsular polysaccharides are an important virulence factor of Streptococcus iniae, protecting the bacterium from destruction and clearance by the immune system. The cpsJ gene encodes a putative UDP-glucose epimerase involved in the capsule synthesis system. To determine the role of the CpsJ protein in the production of the capsule, a ΔcpsJ mutant was generated and analyzed by comparing its growth performances and virulence with those of the wild type (WT) strain. The ΔcpsJ mutant had longer chains, smaller colonies, and a slower growth rate and decreased optical density than the WT, suggesting that the ΔcpsJ mutant produces less capsular polysaccharide. The ΔcpsJ mutant was more able to adhere to and invaded epithelioma papulosum cyprinid cells (EPCs) when its virulence in vitro was compared with that of the WT, but survived less well in the whole blood of channel catfish. When a channel catfish infection model was used to determine the virulence of the ΔcpsJ mutant in vivo, the mutant caused an increase in survival with the mutant (53.33 %) versus the WT (26.67 %). In summary, mutation of the cpsJ gene influenced both the capsule synthesis and virulence of S. iniae.
Collapse
|
35
|
Dwivedi UN, Tiwari S, Prasanna P, Awasthi M, Singh S, Pandey VP. Citrus Functional Genomics and Molecular Modeling in Relation to Citrus sinensis (Sweet Orange) Infection with Xylella fastidiosa (Citrus Variegated Chlorosis). OMICS-A JOURNAL OF INTEGRATIVE BIOLOGY 2016; 20:485-90. [DOI: 10.1089/omi.2016.0062] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- Upendra N. Dwivedi
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| | - Sameeksha Tiwari
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| | - Pragya Prasanna
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| | - Manika Awasthi
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| | - Swati Singh
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| | - Veda P. Pandey
- Bioinformatics Infrastructure Facility, Centre of Excellence in Bioinformatics, Department of Biochemistry, University of Lucknow, Lucknow, India
| |
Collapse
|
36
|
Joo HS, Fu CI, Otto M. Bacterial strategies of resistance to antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2016; 371:20150292. [PMID: 27160595 PMCID: PMC4874390 DOI: 10.1098/rstb.2015.0292] [Citation(s) in RCA: 205] [Impact Index Per Article: 25.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/18/2016] [Indexed: 02/06/2023] Open
Abstract
Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
Collapse
Affiliation(s)
- Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Chih-Iung Fu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| |
Collapse
|
37
|
Joo HS, Fu CI, Otto M. Bacterial strategies of resistance to antimicrobial peptides. Philos Trans R Soc Lond B Biol Sci 2016. [PMID: 27160595 DOI: 10.1098/rstb.2015.0292.] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Antimicrobial peptides (AMPs) are a key component of the host's innate immune system, targeting invasive and colonizing bacteria. For successful survival and colonization of the host, bacteria have a series of mechanisms to interfere with AMP activity, and AMP resistance is intimately connected with the virulence potential of bacterial pathogens. In particular, because AMPs are considered as potential novel antimicrobial drugs, it is vital to understand bacterial AMP resistance mechanisms. This review gives a comparative overview of Gram-positive and Gram-negative bacterial strategies of resistance to various AMPs, such as repulsion or sequestration by bacterial surface structures, alteration of membrane charge or fluidity, degradation and removal by efflux pumps.This article is part of the themed issue 'Evolutionary ecology of arthropod antimicrobial peptides'.
Collapse
Affiliation(s)
- Hwang-Soo Joo
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Chih-Iung Fu
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| | - Michael Otto
- Pathogen Molecular Genetics Section, Laboratory of Bacteriology, National Institute of Allergy and Infectious Diseases (NIAID), US National Institutes of Health (NIH), 50 South Drive, Bethesda, MD 20892, USA
| |
Collapse
|
38
|
Ture M, Altinok I. Detection of putative virulence genes of Lactococcus garvieae. DISEASES OF AQUATIC ORGANISMS 2016; 119:59-66. [PMID: 27068503 DOI: 10.3354/dao02981] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Lactococcus garvieae is the causative agent of lactococcosis and has been isolated from a wide variety of animals. In the present study, 34 strains of L. garvieae isolated from fish from different sources and locations were tested for the presence or absence of the following putative virulence genes: a capsule gene cluster (CGC), hemolysins 1, 2, and 3 (hly1, -2, -3), NADH oxidase, superoxide dismutase (sod), phosphoglucomutase (pgm), adhesin Pav (adhPav), adhesin PsaA (adhPsaA), enolase (eno), LPxTG-containing surface proteins 1, 2, 3, and 4 (LPxTG-1, LPxTG-2, LPxTG-3, LPxTG-4; where LPxTG means Leu-Pro-any-Thr-Gly), adhesin clusters 1 and 2 (adhCI, adhCII), and adhesin (adh). To determine the presence of the CGC, we developed a multiplex PCR. All strains of L. garvieae had the hly1, -2, -3, NADH oxidase, pgm, adhPav, LPxTG-2, LPxTG-3, sod, eno, adhPsaA, adhCII, and adhCII genes, while only the Lg2 strain contained the CGC. The virulent Lg2 strain contained all 17 virulent genes. All Turkish, Spanish, Italian, and French strains did not contain the CGC. The multiplex PCR assay was useful for the detection of the CGC genes. In conclusion, the CGC is not the only virulent factor in L. garvieae because strains that lack the CGC are virulent to rainbow trout. Single genes also might not be responsible for the virulence of L. garvieae.
Collapse
Affiliation(s)
- Mustafa Ture
- Fish Health Department, Central Fisheries Research Institute, 61250 Yomra, Trabzon, Turkey
| | | |
Collapse
|
39
|
Protective efficacy of Streptococcus iniae derived enolase against Streptococcal infection in a zebrafish model. Vet Immunol Immunopathol 2016; 170:25-9. [PMID: 26872628 DOI: 10.1016/j.vetimm.2016.01.004] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 01/05/2016] [Accepted: 01/13/2016] [Indexed: 11/23/2022]
Abstract
Enolase (ENO) is one of the surface-exposed proteins of Streptococcus iniae, which previously had been identified as a plasminogen-binding protein. In this study, ENO was evaluated to induce cross-protective immunity against S. iniae and Streptococcus parauberis which are major pathogens causing streptococcosis in fish. Immunoblot analysis shows that S. iniae recombinant ENO (rENO) produced in Escherichia coli was cross-reactive with antisera against S. iniae, and S. parauberis serotype I and II. In the challenge experiment of streptococcal infection after vaccination in zebrafish, rENO elicited a similar protection with a whole cell bacterin against S. iniae and S. parauberis, which suggests its feasibility as an efficient vaccine against streptococcosis.
Collapse
|
40
|
Zinc disrupts central carbon metabolism and capsule biosynthesis in Streptococcus pyogenes. Sci Rep 2015; 5:10799. [PMID: 26028191 PMCID: PMC4450579 DOI: 10.1038/srep10799] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2015] [Accepted: 04/30/2015] [Indexed: 11/08/2022] Open
Abstract
Neutrophils release free zinc to eliminate the phagocytosed bacterial pathogen Streptococcus pyogenes (Group A Streptococcus; GAS). In this study, we investigated the mechanisms underpinning zinc toxicity towards this human pathogen, responsible for diseases ranging from pharyngitis and impetigo, to severe invasive infections. Using the globally-disseminated M1T1 GAS strain, we demonstrate that zinc stress impairs glucose metabolism through the inhibition of the glycolytic enzymes phosphofructokinase and glyceraldehyde-3-phosphate dehydrogenase. In the presence of zinc, a metabolic shift to the tagatose-6-phosphate pathway allows conversion of D-galactose to dihydroxyacetone phosphate and glyceraldehyde phosphate, partially bypassing impaired glycolytic enzymes to generate pyruvate. Additionally, zinc inhibition of phosphoglucomutase results in decreased capsule biosynthesis. These data indicate that zinc exerts it toxicity via mechanisms that inhibit both GAS central carbon metabolism and virulence pathways.
Collapse
|
41
|
El Aamri F, Remuzgo-Martínez S, Acosta F, Real F, Ramos-Vivas J, Icardo JM, Padilla D. Interactions of Streptococcus iniae with phagocytic cell line. Microbes Infect 2015; 17:258-65. [DOI: 10.1016/j.micinf.2014.06.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Revised: 05/20/2014] [Accepted: 06/06/2014] [Indexed: 10/25/2022]
|
42
|
LaRock CN, Nizet V. Cationic antimicrobial peptide resistance mechanisms of streptococcal pathogens. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2015; 1848:3047-54. [PMID: 25701232 DOI: 10.1016/j.bbamem.2015.02.010] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 02/04/2015] [Accepted: 02/07/2015] [Indexed: 02/06/2023]
Abstract
Cationic antimicrobial peptides (CAMPs) are critical front line contributors to host defense against invasive bacterial infection. These immune factors have direct killing activity toward microbes, but many pathogens are able to resist their effects. Group A Streptococcus, group B Streptococcus and Streptococcus pneumoniae are among the most common pathogens of humans and display a variety of phenotypic adaptations to resist CAMPs. Common themes of CAMP resistance mechanisms among the pathogenic streptococci are repulsion, sequestration, export, and destruction. Each pathogen has a different array of CAMP-resistant mechanisms, with invasive disease potential reflecting the utilization of several mechanisms that may act in synergy. Here we discuss recent progress in identifying the sources of CAMP resistance in the medically important Streptococcus genus. Further study of these mechanisms can contribute to our understanding of streptococcal pathogenesis, and may provide new therapeutic targets for therapy and disease prevention. This article is part of a Special Issue entitled: Bacterial Resistance to Antimicrobial Peptides.
Collapse
Affiliation(s)
- Christopher N LaRock
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA.
| | - Victor Nizet
- Department of Pediatrics, University of California, San Diego, La Jolla, CA, USA; Skaggs School of Medicine and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA, USA; Rady Children's Hospital, San Diego, CA, USA.
| |
Collapse
|
43
|
Woo SH, Park SI. Effects of phosphoglucomutase gene (PGM) in Streptococcus parauberis on innate immune response and pathogenicity of olive flounder (Paralichthys olivaceus). FISH & SHELLFISH IMMUNOLOGY 2014; 41:317-325. [PMID: 25240979 DOI: 10.1016/j.fsi.2014.09.012] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2014] [Revised: 08/26/2014] [Accepted: 09/10/2014] [Indexed: 06/03/2023]
Abstract
In recent years, Streptococcus parauberis infection has been an emerging problem in aquaculture in South Korea because of its more frequent isolation than other streptococcal bacteria including Streptococcus iniae. To develop effective treatment and prophylaxis methods against this emerging disease by S. parauberis, it is necessary to understand the underlying pathogenic mechanisms. To uncover the pathogenicity, the mutant strain of S. parauberis with a deleted phosphoglucomutase (PGM) gene which has been known to be an important virulence factor in bacterial pathogens was generated to investigate the relationship between virulence and gene function using an allelic exchange mutagenesis method. Allelic exchange mutagenesis of the phosphoglucomutase gene resulted in phenotype changes including decreased extracellular capsules, reduced buoyancy, increased hydrophobicity and reduced growth. Moreover, the S. parauberis mutant was more sensitive to innate immune clearance mechanisms including serum, mucus and phagocyte killing and could not induce mortality in olive flounder. These phenotype changes and the attenuated virulence of the pathogen to fish could be due to the reduction in capsule production by mutation of the PGM gene. The results provide evidences that phosphoglucomutase expression contributes to S. parauberis virulence in fish by affecting bacterial survival against the host's humoral and cellular defense mechanisms.
Collapse
Affiliation(s)
- Sung Ho Woo
- Institute of Fisheries Sciences, Pukyong National University, 474, Ilgwang-Ro, Ilgwang-myeon, Gijang-gun, Busan 619-911, South Korea; Department of Aquatic Life Medicine, Pukyong National University, 45, Yongso-ro, Namgu, Busan 608-737, South Korea.
| | - Soo Il Park
- Department of Aquatic Life Medicine, Pukyong National University, 45, Yongso-ro, Namgu, Busan 608-737, South Korea.
| |
Collapse
|
44
|
Wang J, Zou LL, Li AX. Construction of a Streptococcus iniae sortase A mutant and evaluation of its potential as an attenuated modified live vaccine in Nile tilapia (Oreochromis niloticus). FISH & SHELLFISH IMMUNOLOGY 2014; 40:392-398. [PMID: 25090938 DOI: 10.1016/j.fsi.2014.07.028] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/15/2014] [Revised: 07/20/2014] [Accepted: 07/22/2014] [Indexed: 06/03/2023]
Abstract
Streptococcus iniae is a major Gram-positive aquatic pathogen, which causes invasive diseases in cultured fish worldwide. The identification of potential virulence determinants of streptococcal infections will help to understand and control this disease, but only a few have been confirmed in S. iniae. Sortase A (srtA) is the key enzyme that anchors pre-mature cell wall-attached proteins to peptidoglycan and it can affect the correct positioning of surface proteins, as well as the course of Gram-positive bacterial infection, thereby making it a potential target in the study of virulence factors and disease control. In this study, the 759 bp srtA gene was cloned from pathogenic S. iniae TBY-1 strain and the mutant strain TBY-1ΔsrtA was constructed via allelic exchange mutagenesis. We found that srtA shares high similarities with sortase A from other Streptococcus spp. Direct survival rate assay and challenge experiments were performed, which showed that the mutant strain TBY-1ΔsrtA had a lower survival capacity in healthy tilapia blood and it was less virulent than the wild type strain in tilapia, thereby indicating that the deletion of sortase A affects the virulence and infectious capacity of S. iniae. The mutant strain TBY-1ΔsrtA was used as a live vaccine, which was administered via intraperitoneal injection, and it provided the relative percent survival value of 95.5% in Nile tilapia, thereby demonstrating its high potential as an effective attenuated live vaccine candidate.
Collapse
Affiliation(s)
- J Wang
- State Key Laboratory of Bio-control, Key Laboratory for Aquatic Products Safety of Ministry of Education, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang West Road, Haizhu District, Guangzhou 510275, Guangdong Province, PR China.
| | - L L Zou
- Hubei Province Key Laboratory of Pathogenic Microorganism, Medical College, China Three Gorges University, 8 Daxue Road, Xiling District, Yichang 443002, Hubei Province, PR China.
| | - A X Li
- State Key Laboratory of Bio-control, Key Laboratory for Aquatic Products Safety of Ministry of Education, Guangdong Provincial Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang West Road, Haizhu District, Guangzhou 510275, Guangdong Province, PR China.
| |
Collapse
|
45
|
Cheng ZX, Ma YM, Li H, Peng XX. N-acetylglucosamine enhances survival ability of tilapias infected by Streptococcus iniae. FISH & SHELLFISH IMMUNOLOGY 2014; 40:524-30. [PMID: 25120218 DOI: 10.1016/j.fsi.2014.08.008] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/13/2014] [Accepted: 08/03/2014] [Indexed: 05/20/2023]
Abstract
Streptococcus iniae infection has emerged as a serious fish health and economic problem in the global aquaculture operations. Current antibiotic options are few and possess severe practical limitations and potential adverse environmental impacts. The major factor contributing to the large burden of S. iniae disease in aquaculture is the lack of fundamental knowledge of innate immunity against the pathogen. In the present study, we use a tilapia model to explore which metabolites are crucial for the defense against the infection caused by S. iniae. We establish GC/MS based metabolic profile of tilapia liver and then compare the metabolic difference between survivals and the dying fish post the bacterial infection. We identify elevating N-acetylglucosamine in survival group as the most crucial metabolite differentiating the survivals from the dying in these fish infected by S. iniae. Exogenous N-acetylglucosamine significantly elevates survival ability of tilapia against the infection caused by S. iniae. Our findings highlight the importance of metabolic strategy against bacterial infections.
Collapse
Affiliation(s)
- Zhi-xue Cheng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China
| | - Yan-mei Ma
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China
| | - Hui Li
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
| | - Xuan-xian Peng
- Center for Proteomics and Metabolomics, State Key Laboratory of Bio-Control, MOE Key Lab Aquatic Food Safety, School of Life Sciences, Sun Yat-sen University, University City, Guangzhou 510006, People's Republic of China.
| |
Collapse
|
46
|
Lupo A, Ruppen C, Hemphill A, Spellerberg B, Sendi P. Phenotypic and molecular characterization of hyperpigmented group B Streptococci. Int J Med Microbiol 2014; 304:717-24. [PMID: 24933304 DOI: 10.1016/j.ijmm.2014.05.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2013] [Revised: 05/05/2014] [Accepted: 05/11/2014] [Indexed: 10/25/2022] Open
Abstract
Group B Streptococcus (GBS) causes invasive infections in neonates, older adults and patients with comorbidities. β-hemolysin/cytolysin is an important GBS virulence factor. It is encoded by the cyl operon and confers GBS hemolytic activity. Isolates displaying hyperpigmentation are typically hyperhemolytic. Comparison of clonally identical isolates displaying different levels of pigmentation has shown transcriptional dysregulation due to mutations in components of the control of the virulence S/R (CovS/R) regulatory system. In addition, hyperpigmented isolates show decreased CAMP factor and decreased capsule thickness. In analogy to findings in group A Streptococcus, a pivotal role of CovS/R has been proposed in the host-pathogen interaction of invasive GBS infection. However, corresponding investigations on multiple clinical GBS isolates have not been performed. We prospectively collected hyperpigmented isolates found in a diagnostic laboratory and performed phenotypic, molecular and transcriptional analyses. In the period from 2008 to 2012, we found 10 isolates obtained from 10 patients. The isolates reflected both invasive pathogens and colonizers. In three cases, clonally identical but phenotypically different variants were also found. Hence, the analyses included 13 isolates. No capsular serotype was found to be significantly more frequent. Bacterial pigments were analyzed via spectrophotometry and for their hemolytic activity. Data obtained for typical absorbance spectra peaks correlated significantly with hemolytic activity. Molecular analysis of the cyl operon showed that it was conserved in all isolates. The covR sequence displayed mutations in five isolates; in one isolate, the CovR binding site to cylX was abrogated. Our results on clinical isolates support previous findings on CovR-deficient isogenic mutants, but suggest that - at least in some clinical isolates - for β-hemolysin/cytolysin and CAMP factor production, other molecular pathways may be involved.
Collapse
Affiliation(s)
- Agnese Lupo
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Corinne Ruppen
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland
| | - Andrew Hemphill
- Institute of Parasitology, University of Bern, Bern, Switzerland
| | - Barbara Spellerberg
- Institute of Medical Microbiology and Hygiene, University Hospital Ulm, Ulm, Germany
| | - Parham Sendi
- Institute for Infectious Diseases, University of Bern, Bern, Switzerland; Department of Infectious Diseases, Bern University Hospital, Bern, Switzerland.
| |
Collapse
|
47
|
Li MF, Zhang BC, Li J, Sun L. Sil: a Streptococcus iniae bacteriocin with dual role as an antimicrobial and an immunomodulator that inhibits innate immune response and promotes S. iniae infection. PLoS One 2014; 9:e96222. [PMID: 24781647 PMCID: PMC4004548 DOI: 10.1371/journal.pone.0096222] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2014] [Accepted: 04/04/2014] [Indexed: 11/18/2022] Open
Abstract
Streptococcus iniae is a Gram-positive bacterium and a severe pathogen to a wide range of economically important fish species. In addition, S. iniae is also a zoonotic pathogen and can cause serious infections in humans. In this study, we identified from a pathogenic S. iniae strain a putative bacteriocin, Sil, and examined its biological activity. Sil is composed of 101 amino acid residues and shares 35.6% overall sequence identity with the lactococcin 972 of Lactococcus lactis. Immunoblot analysis showed that Sil was secreted by S. iniae into the extracellular milieu. Purified recombinant Sil (rSil) exhibited a dose-dependent inhibitory effect on the growth of Bacillus subtilis but had no impact on the growths of other 16 Gram-positive bacteria and 10 Gram-negative bacteria representing 23 different bacterial species. Treatment of rSil by heating at 50°C abolished the activity of rSil. rSil bound to the surface of B. subtilis but induced no killing of the target cells. Cellular study revealed that rSil interacted with turbot (Scophthalmus maximus) head kidney monocytes and inhibited the innate immune response of the cells, which led to enhanced cellular infection of S. iniae. Antibody blocking of the extracellular Sil produced by S. iniae significantly attenuated the infectivity of S. iniae. Consistent with these in vitro observations, in vivo study showed that administration of turbot with rSil prior to S. iniae infection significantly increased bacterial dissemination and colonization in fish tissues. Taken together, these results indicate that Sil is a novel virulence-associated bacteriostatic and an immunoregulator that promotes S. iniae infection by impairing the immune defense of host fish.
Collapse
Affiliation(s)
- Mo-fei Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Bao-cun Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Jun Li
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- School of Biological Sciences, Lake Superior State University, Sault Ste Marie, Michigan, United States of America
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Collaborative Innovation Center of Deep Sea Biology, Zhejiang University, Hangzhou, China
- * E-mail:
| |
Collapse
|
48
|
Zhang BC, Zhang J, Sun L. Streptococcus iniae SF1: complete genome sequence, proteomic profile, and immunoprotective antigens. PLoS One 2014; 9:e91324. [PMID: 24621602 PMCID: PMC3951389 DOI: 10.1371/journal.pone.0091324] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2013] [Accepted: 02/10/2014] [Indexed: 01/06/2023] Open
Abstract
Streptococcus iniae is a Gram-positive bacterium that is reckoned one of the most severe aquaculture pathogens. It has a broad host range among farmed marine and freshwater fish and can also cause zoonotic infection in humans. Here we report for the first time the complete genome sequence as well as the host factor-induced proteomic profile of a pathogenic S. iniae strain, SF1, a serotype I isolate from diseased fish. SF1 possesses a single chromosome of 2,149,844 base pairs, which contains 2,125 predicted protein coding sequences (CDS), 12 rRNA genes, and 45 tRNA genes. Among the protein-encoding CDS are genes involved in resource acquisition and utilization, signal sensing and transduction, carbohydrate metabolism, and defense against host immune response. Potential virulence genes include those encoding adhesins, autolysins, toxins, exoenzymes, and proteases. In addition, two putative prophages and a CRISPR-Cas system were found in the genome, the latter containing a CRISPR locus and four cas genes. Proteomic analysis detected 21 secreted proteins whose expressions were induced by host serum. Five of the serum-responsive proteins were subjected to immunoprotective analysis, which revealed that two of the proteins were highly protective against lethal S. iniae challenge when used as purified recombinant subunit vaccines. Taken together, these results provide an important molecular basis for future study of S. iniae in various aspects, in particular those related to pathogenesis and disease control.
Collapse
Affiliation(s)
- Bao-cun Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Jian Zhang
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Graduate University of the Chinese Academy of Sciences, Beijing, China
| | - Li Sun
- Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao, China
- Collaborative Innovation Center of Deep Sea Biology, Zhejiang University, Hangzhou, China
- * E-mail:
| |
Collapse
|
49
|
Sun Y, Sun L, Xing MQ, Liu CS, Hu YH. SagE induces highly effective protective immunity against Streptococcus iniae mainly through an immunogenic domain in the extracellular region. Acta Vet Scand 2013; 55:78. [PMID: 24215645 PMCID: PMC3829104 DOI: 10.1186/1751-0147-55-78] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Accepted: 11/03/2013] [Indexed: 11/10/2022] Open
Abstract
Background Streptococcus iniae is a Gram-positive bacterium and a severe pathogen of a wide range of farmed fish. S. iniae possesses a virulence-associated streptolysin S cluster composed of several components, one of which is SagE. SagE a transmembrane protein with one major extracellular region named ECR. This study aimed to develop a SagE-based DNA candidate vaccine against streptococcosis and examine the immunoprotective mechanism of the vaccine. Results We constructed a DNA vaccine, pSagE, based on the sagE gene and examined its immunological property in a Japanese flounder (Paralichthys olivaceus) model. The results showed that at 7 days post-vaccination, expression of SagE at transcription and translation levels was detected in the tissues of the vaccinated fish. After challenge with S. iniae at one and two months post-vaccination, pSagE-vaccinated fish exhibited relative percent survival (RPS) of 95% and 88% respectively. Immunological analysis showed that (i) pSagE significantly upregulated the expression of a wide range of immune genes, (ii) pSagE induced the production of specific serum antibodies that bound whole-cell S. iniae, and (iii) treatment of S. iniae with pSagE-induced antibodies blocked bacterial invasion of host cells. To localize the immunoprotective domain of SagE, the ECR-expressing DNA vaccine pSagEECR was constructed. Immunization analysis showed that flounder vaccinated with pSagEECR exhibited a RPS of 68%, and that pSagEECR induced serum antibody production and immune gene expression in a manner similar to, though to lower magnitudes than, those induced by pSagE. Conclusions We in this study developed a DNA vaccine, pSagE, which induces highly protective immunity against S. iniae. The protective effect of pSagE is probably due to its ability to elicit systemic immune response, in particular that of the humoral branch, which leads to production of specific serum antibodies that impair bacterial infection. These results add insights to the immunoprotective mechanism of fish DNA vaccine.
Collapse
|
50
|
Inactivation of the phosphoglucomutase gene pgm in Corynebacterium glutamicum affects cell shape and glycogen metabolism. Biosci Rep 2013; 33:BSR20130076. [PMID: 23863124 PMCID: PMC3755335 DOI: 10.1042/bsr20130076] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
In Corynebacterium glutamicum formation of glc-1-P (α-glucose-1-phosphate) from glc-6-P (glucose-6-phosphate) by α-Pgm (phosphoglucomutase) is supposed to be crucial for synthesis of glycogen and the cell wall precursors trehalose and rhamnose. Furthermore, Pgm is probably necessary for glycogen degradation and maltose utilization as glucan phosphorylases of both pathways form glc-1-P. We here show that C. glutamicum possesses at least two Pgm isoenzymes, the cg2800 (pgm) encoded enzyme contributing most to total Pgm activity. By inactivation of pgm we created C. glutamicum IMpgm showing only about 12% Pgm activity when compared to the parental strain. We characterized both strains during cultivation with either glucose or maltose as substrate and observed that (i) the glc-1-P content in the WT (wild-type) and the mutant remained constant independent of the carbon source used, (ii) the glycogen levels in the pgm mutant were lower during growth on glucose and higher during growth on maltose, and (iii) the morphology of the mutant was altered with maltose as a substrate. We conclude that C. glutamicum employs glycogen as carbon capacitor to perform glc-1-P homeostasis in the exponential growth phase and is therefore able to counteract limited Pgm activity for both anabolic and catabolic metabolic pathways.
Collapse
|