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Guo X, Chen H, Tong Y, Wu X, Tang C, Qin X, Guo J, Li P, Wang Z, Liu W, Mo J. A review on the antibiotic florfenicol: Occurrence, environmental fate, effects, and health risks. ENVIRONMENTAL RESEARCH 2024; 244:117934. [PMID: 38109957 DOI: 10.1016/j.envres.2023.117934] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2023] [Revised: 12/09/2023] [Accepted: 12/11/2023] [Indexed: 12/20/2023]
Abstract
Florfenicol, as a replacement for chloramphenicol, can tightly bind to the A site of the 23S rRNA in the 50S subunit of the 70S ribosome, thereby inhibiting protein synthesis and bacterial proliferation. Due to the widespread use in aquaculture and veterinary medicine, florfenicol has been detected in the aquatic environment worldwide. Concerns over the effects and health risks of florfenicol on target and non-target organisms have been raised in recent years. Although the ecotoxicity of florfenicol has been widely reported in different species, no attempt has been made to review the current research progress of florfenicol toxicity, hormesis, and its health risks posed to biota. In this study, a comprehensive literature review was conducted to summarize the effects of florfenicol on various organisms including bacteria, algae, invertebrates, fishes, birds, and mammals. The generation of antibiotic resistant bacteria and spread antibiotic resistant genes, closely associated with hormesis, are pressing environmental health issues stemming from overuse or misuse of antibiotics including florfenicol. Exposure to florfenicol at μg/L-mg/L induced hormetic effects in several algal species, and chromoplasts might serve as a target for florfenicol-induced effects; however, the underlying molecular mechanisms are completely lacking. Exposure to high levels (mg/L) of florfenicol modified the xenobiotic metabolism, antioxidant systems, and energy metabolism, resulting in hepatotoxicity, renal toxicity, immunotoxicity, developmental toxicity, reproductive toxicity, obesogenic effects, and hormesis in different animal species. Mitochondria and the associated energy metabolism are suggested to be the primary targets for florfenicol toxicity in animals, albeit further in-depth investigations are warranted for revealing the long-term effects (e.g., whole-life-cycle impacts, multigenerational effects) of florfenicol, especially at environmental levels, and the underlying mechanisms. This will facilitate the evaluation of potential hormetic effects and construction of adverse outcome pathways for environmental risk assessment and regulation of florfenicol.
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Affiliation(s)
- Xingying Guo
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Haibo Chen
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Yongqi Tong
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Xintong Wu
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Can Tang
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Xian Qin
- State Key Laboratory of Marine Pollution, City University of Hong Kong, Kowloon, Hong Kong SAR, China
| | - Jiahua Guo
- Shaanxi Key Laboratory of Earth Surface System and Environmental Carrying Capacity, College of Urban and Environmental Sciences, Northwest University, Xi'an, 710127, China
| | - Ping Li
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Zhen Wang
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Wenhua Liu
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China
| | - Jiezhang Mo
- Guangdong Provincial Key Laboratory of Marine Disaster Prediction and Prevention, Shantou University, Shantou, 515063, China.
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Robinson NA, Robledo D, Sveen L, Daniels RR, Krasnov A, Coates A, Jin YH, Barrett LT, Lillehammer M, Kettunen AH, Phillips BL, Dempster T, Doeschl‐Wilson A, Samsing F, Difford G, Salisbury S, Gjerde B, Haugen J, Burgerhout E, Dagnachew BS, Kurian D, Fast MD, Rye M, Salazar M, Bron JE, Monaghan SJ, Jacq C, Birkett M, Browman HI, Skiftesvik AB, Fields DM, Selander E, Bui S, Sonesson A, Skugor S, Østbye TK, Houston RD. Applying genetic technologies to combat infectious diseases in aquaculture. REVIEWS IN AQUACULTURE 2023; 15:491-535. [PMID: 38504717 PMCID: PMC10946606 DOI: 10.1111/raq.12733] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Revised: 07/24/2022] [Accepted: 08/16/2022] [Indexed: 03/21/2024]
Abstract
Disease and parasitism cause major welfare, environmental and economic concerns for global aquaculture. In this review, we examine the status and potential of technologies that exploit genetic variation in host resistance to tackle this problem. We argue that there is an urgent need to improve understanding of the genetic mechanisms involved, leading to the development of tools that can be applied to boost host resistance and reduce the disease burden. We draw on two pressing global disease problems as case studies-sea lice infestations in salmonids and white spot syndrome in shrimp. We review how the latest genetic technologies can be capitalised upon to determine the mechanisms underlying inter- and intra-species variation in pathogen/parasite resistance, and how the derived knowledge could be applied to boost disease resistance using selective breeding, gene editing and/or with targeted feed treatments and vaccines. Gene editing brings novel opportunities, but also implementation and dissemination challenges, and necessitates new protocols to integrate the technology into aquaculture breeding programmes. There is also an ongoing need to minimise risks of disease agents evolving to overcome genetic improvements to host resistance, and insights from epidemiological and evolutionary models of pathogen infestation in wild and cultured host populations are explored. Ethical issues around the different approaches for achieving genetic resistance are discussed. Application of genetic technologies and approaches has potential to improve fundamental knowledge of mechanisms affecting genetic resistance and provide effective pathways for implementation that could lead to more resistant aquaculture stocks, transforming global aquaculture.
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Affiliation(s)
- Nicholas A. Robinson
- Nofima ASTromsøNorway
- Sustainable Aquaculture Laboratory—Temperate and Tropical (SALTT)School of BioSciences, The University of MelbourneMelbourneVictoriaAustralia
| | - Diego Robledo
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | | | - Rose Ruiz Daniels
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | | | - Andrew Coates
- Sustainable Aquaculture Laboratory—Temperate and Tropical (SALTT)School of BioSciences, The University of MelbourneMelbourneVictoriaAustralia
| | - Ye Hwa Jin
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | - Luke T. Barrett
- Sustainable Aquaculture Laboratory—Temperate and Tropical (SALTT)School of BioSciences, The University of MelbourneMelbourneVictoriaAustralia
- Institute of Marine Research, Matre Research StationMatredalNorway
| | | | | | - Ben L. Phillips
- Sustainable Aquaculture Laboratory—Temperate and Tropical (SALTT)School of BioSciences, The University of MelbourneMelbourneVictoriaAustralia
| | - Tim Dempster
- Sustainable Aquaculture Laboratory—Temperate and Tropical (SALTT)School of BioSciences, The University of MelbourneMelbourneVictoriaAustralia
| | - Andrea Doeschl‐Wilson
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | - Francisca Samsing
- Sydney School of Veterinary ScienceThe University of SydneyCamdenAustralia
| | | | - Sarah Salisbury
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | | | | | | | | | - Dominic Kurian
- The Roslin Institute and Royal (Dick) School of Veterinary StudiesThe University of EdinburghEdinburghUK
| | - Mark D. Fast
- Atlantic Veterinary CollegeThe University of Prince Edward IslandCharlottetownPrince Edward IslandCanada
| | | | | | - James E. Bron
- Institute of AquacultureUniversity of StirlingStirlingScotlandUK
| | - Sean J. Monaghan
- Institute of AquacultureUniversity of StirlingStirlingScotlandUK
| | - Celeste Jacq
- Blue Analytics, Kong Christian Frederiks Plass 3BergenNorway
| | | | - Howard I. Browman
- Institute of Marine Research, Austevoll Research Station, Ecosystem Acoustics GroupTromsøNorway
| | - Anne Berit Skiftesvik
- Institute of Marine Research, Austevoll Research Station, Ecosystem Acoustics GroupTromsøNorway
| | | | - Erik Selander
- Department of Marine SciencesUniversity of GothenburgGothenburgSweden
| | - Samantha Bui
- Institute of Marine Research, Matre Research StationMatredalNorway
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Shi F, Huang Y, Yang M, Lu Z, Li Y, Zhan F, Lin L, Qin Z. Antibiotic-induced alternations in gut microflora are associated with the suppression of immune-related pathways in grass carp (Ctenopharyngodon idellus). Front Immunol 2022; 13:970125. [PMID: 36032163 PMCID: PMC9403240 DOI: 10.3389/fimmu.2022.970125] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 07/20/2022] [Indexed: 11/19/2022] Open
Abstract
Gut microbiota play a vital role in fish health homeostasis. Antibiotics are known to alter microbial community composition and diversity; however, the substantial effects of antibiotics upon the gut microbiome with respect to immune-related pathways in healthy fish remain unclear. Accordingly, here we explored the impact of two antibiotics on the intestinal health, immune response, microbiome dynamics, and transcriptome profiles of grass carp. A two-week feeding trial was carried out in which the basal diet was complemented with enrofloxacin (10 mg/kg) or florfenicol (10 mg/kg). The results showed that: (1) Enrofloxacin and florfenicol both induced intestinal oxidative stress and reduced the digestive enzyme activity of grass carp. (2) High-throughput sequencing of 16S rDNA revealed that enrofloxacin but not the florfenicol treatment influenced gut microbiota diversity in grass carp by shifting α/β-diversity with more abundant pathogens detected. (3) Transcriptome profiling demonstrated that florfenicol down-regulated the immune-related pathways of grass carp, and the network analysis revealed that IgA was negatively correlated with certain pathogens, such as Shewanella and Aeromonas. (4) Antibiotic-induced alternations of gut core microbes were revealed via immune-related transcripts, as were lower mRNA expression levels of mucosal-related genes. (5) Apoptosis and histopathological changes were detected in the enrofloxacin- and florfenicol-treated groups compared with the control group. Overall, administering antibiotics will promote oxidative stress, cause intestinal flora dysbiosis, inhibit the mucosal immune system, and induce apoptosis in grass carp.
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Affiliation(s)
| | | | | | | | | | | | - Li Lin
- *Correspondence: Li Lin, ; Zhendong Qin,
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Yin L, Liang C, Wei W, Huang S, Ren Y, Geng Y, Huang X, Chen D, Guo H, Fang J, Deng H, Lai W, Yu S, Ouyang P. The Antibacterial Activity of Thymol Against Drug-Resistant Streptococcus iniae and Its Protective Effect on Channel Catfish (Ictalurus punctatus). Front Microbiol 2022; 13:914868. [PMID: 35733967 PMCID: PMC9207766 DOI: 10.3389/fmicb.2022.914868] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 05/02/2022] [Indexed: 12/30/2022] Open
Abstract
Streptococcus iniae is a zoonotic pathogen, which seriously threatens aquaculture and human health worldwide. Antibiotics are the preferred way to treat S. iniae infection. However, the unreasonable use of antibiotics leads to the enhancement of bacterial resistance, which is not conducive to the prevention and treatment of this disease. Therefore, it is urgent to find new efficient and environmentally friendly antibacterial agents to replace traditional antibiotics. In this study, the antibacterial activity and potential mechanism of thymol against S. iniae were evaluated by electron microscopy, lactate dehydrogenase, DNA and protein leakage and transcriptomic analysis. Thymol exhibited potent antibacterial activity against S. iniae in vitro, and the MIC and MBC were 128 and 256μg/mL, respectively. SEM and TEM images showed that the cell membrane and cell wall were damaged, and the cells were abnormally enlarged and divided. 2MIC thymol disrupted the integrity of cell walls and membranes, resulting in the release of intracellular macromolecules including nucleotides, proteins and inorganic ions. The results of transcriptomic analysis indicated that thymol interfered with energy metabolism and membrane transport, affected DNA replication, repair and transcription in S. iniae. In vivo studies showed that thymol had a protective effect on experimental S. iniae infection in channel catfish. It could reduce the cumulative mortality of channel catfish and the number of S. iniae colonization in tissues, and increase the activities of non-specific immune enzymes in serum, including catalase, superoxide dismutase, lysozyme and acid phosphatase. Taken together, these findings suggested that thymol may be a candidate plant agent to replace traditional antibiotics for the prevention and treatment of S. iniae infection.
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Affiliation(s)
- Lizi Yin
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Chao Liang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Wenyan Wei
- Aquaculture Research Institute, Chengdu Academy of Agriculture and Forestry Sciences, Chengdu, China
| | - Shuanghui Huang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yongqiang Ren
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yi Geng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaoli Huang
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Defang Chen
- Department of Aquaculture, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China
| | - Hongrui Guo
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Jing Fang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Huidan Deng
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Weimin Lai
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shumin Yu
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ping Ouyang
- Department of Basic Veterinary, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- *Correspondence: Ping Ouyang
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Maulu S, Hasimuna OJ, Mphande J, Munang'andu HM. Prevention and Control of Streptococcosis in Tilapia Culture: A Systematic Review. JOURNAL OF AQUATIC ANIMAL HEALTH 2021; 33:162-177. [PMID: 34121243 DOI: 10.1002/aah.10132] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/01/2021] [Accepted: 04/14/2021] [Indexed: 06/12/2023]
Abstract
Tilapia culture is a very promising industry within the aquaculture sector. However, disease outbreaks have continued to threaten the industry, causing serious economic losses among the producers. Streptococcosis has become the major bacterial disease affecting tilapia production in most regions of the world. To combat the disease and minimize its economic impact on fish producers, numerous preventive and control measures have been developed and reported over the years. This paper aims to systematically review the measures that could be used to manage the disease outbreaks and maintain fish health based on previously published scientific studies. Although numerous measures currently available have been highlighted, it is far better for the producers to maximize the preventive measures for management to be economically feasible. Among the currently available preventive measures, the use of vaccines has been shown to have the most promise, while the use of herbs has been demonstrated to be a more sustainable and economically affordable control measure. However, there are still a number of important gaps in existing literature that require further investigation. Overall, significant progress has been made in preventing and controlling streptococcosis in tilapia although, no single effective measure has been identified. Therefore, a combination of these measures may provide a more effective result.
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Affiliation(s)
- Sahya Maulu
- Centre for Innovative Approach Zambia, Lusaka Central Business Area, Post Office Box 30135, Lusaka, Zambia
| | - Oliver J Hasimuna
- Ministry of Fisheries and Livestock, National Aquaculture Research and Development Centre, Post Office Box 22797, Mwekera, Kitwe, Zambia
- Department of Zoology and Aquatic Sciences, Copperbelt University, Post Office Box 21692, Kitwe, Zambia
| | - Joseph Mphande
- Ministry of Fisheries and Livestock, Department of Fisheries, Post Office Box 70416, Ndola, Zambia
| | - Hetron M Munang'andu
- Section of Aquatic Medicine and Nutrition, Faculty of Veterinary Medicine and Biosciences, Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Adamstuen Campus, Post Office Box 369, Oslo, 0102, Norway
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Zhang Y, Deng Y, Feng J, Guo Z, Chen H, Wang B, Hu J, Lin Z, Su Y. Functional characterization of VscCD, an important component of the type Ⅲ secretion system of Vibrio harveyi. Microb Pathog 2021; 157:104965. [PMID: 34015493 DOI: 10.1016/j.micpath.2021.104965] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 03/23/2021] [Accepted: 05/11/2021] [Indexed: 11/19/2022]
Abstract
Vibrio harveyi is a Gram-negative bacterium that occurs widely in the ocean and a kind of pathogenic bacteria associated with vibriosis in grouper. We investigated whether the VscCD protein of the type Ⅲ secretion system (T3SS) was important for pathogenicity of V. harveyi. Mutations to the vscC and vscD genes (ΔvscCD) and complementation of the ΔvscCD mutant (C-ΔvscCD) were created. Moreover, the biological characteristics of the wild-type (WT) and mutant strains of V. harveyi 345 were compared. The results showed that deletion of the vscCD genes had no effect on bacterial growth, swimming/swarming ability, secretion of extracellular protease, or biofilm formation. However, as compared with the V. harveyi 345: pMMB207 (WT+) and complementary (C-ΔvscCD) strains, the ΔvscCD: pMMB207 (ΔvscCD+) mutant displayed decreased resistance to acid stress, H2O2, and antibiotics. In addition, infection of the pearl gentian grouper (♀Epinephelus fuscoguttatus × ♂Epinephelus lanceolatu) showed that as compared with the WT+ and C-ΔvscCD strains, the ΔvscCD+ strain significantly reduced cumulative mortality of the host. The colonization ability of the ΔvscCD+ mutant in the spleen and liver tissues of the pearl gentian grouper was significantly lower than that of the WT+ and C-ΔvscCD strains. In the early stage of infection with the ΔvscCD+ strain, the expression levels of IL-1β, IL-16, TLR3, TNF-α, MHC-Iα, and CD8α were up-regulated to varying degrees. As compared with the WT+ and C-ΔvscCD strains, luxR expression was significantly up-regulated in the ΔvscCD+ strain, while the expression of vcrH and vp1668 was significantly down-regulated. As an important component of the T3SS, VscCD seemed to play a significant role in the pathogenesis of V. harveyi.
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Affiliation(s)
- Yaqiu Zhang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Yiqin Deng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China.
| | - Juan Feng
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Zhixun Guo
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Haoxiang Chen
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Baotun Wang
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Jianmei Hu
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; College of Fisheries and Life Science, Shanghai Ocean University, Shanghai 201306, China
| | - Ziyang Lin
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China
| | - Youlu Su
- Key Laboratory of South China Sea Fishery Resources Exploitation & Utilization, Ministry of Agriculture and Rural Affairs, South China Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Guangzhou 510300, China; Innovative Institute of Animal Healthy Breeding, Zhongkai University of Agriculture and Engineering, Guangzhou 510225, China.
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Research Advances on Tilapia Streptococcosis. Pathogens 2021; 10:pathogens10050558. [PMID: 34066313 PMCID: PMC8148123 DOI: 10.3390/pathogens10050558] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Revised: 03/14/2021] [Accepted: 03/17/2021] [Indexed: 12/14/2022] Open
Abstract
Streptococcus agalactiae, often referred to as group B streptococci (GBS), is a severe pathogen that can infect humans as well as other animals, including tilapia, which is extremely popular in commercial aquaculture. This pathogen causes enormous pecuniary loss, and typical symptoms of streptococcosis—the disease caused by S. agalactiae—include abnormal behavior, exophthalmos, and meningitis, among others. Multiple studies have examined virulence factors associated with S. agalactiae infection, and vaccines were explored, including studies of subunit vaccines. Known virulence factors include capsular polysaccharide (CPS), hemolysin, Christie-Atkins-Munch-Peterson (CAMP) factor, hyaluronidase (HAase), superoxide dismutase (SOD), and serine-threonine protein kinase (STPK), and effective vaccine antigens reported to date include GapA, Sip, OCT, PGK, FbsA, and EF-Tu. In this review, I summarize findings from several studies about the etiology, pathology, virulence factors, and vaccine prospects for S. agalactiae. I end by considering which research areas are likely to yield success in the prevention and treatment of tilapia streptococcosis.
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Genomic characteristics of Streptococcus agalactiae based on the pan-genome orthologous group analysis according to invasiveness and capsular genotype. J Infect Chemother 2021; 27:814-819. [PMID: 33526285 DOI: 10.1016/j.jiac.2021.01.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/10/2021] [Accepted: 01/13/2021] [Indexed: 11/21/2022]
Abstract
OBJECTIVE Following the construction of a bacterial pan-genome from the whole genome sequences on a web-based pipeline, all coding DNA sequences (CDSs) can be clustered into pan-genome orthologous groups (POGs), which is a similar approach to comparative genome hybridization on glass microscope slides. We aimed to clarify the genomic characteristics of Streptococcus agalactiae based on the POG analysis. METHODS Sixty-six S. agalactiae isolates obtained from invasive specimens (blood and cerebrospinal fluid) and non-invasive specimens (urine and vaginal discharge) between 2010 and 2017 in Korea were subjected to whole genome sequencing (WGS). Based on the WGS data, we conducted the POG analysis and constructed a phylogenetic tree along with capsular polysaccharide (CPS) genotyping. We compared the genomics of invasive vs. non-invasive isolates, as well as CPS III vs. non-CPS III genotypes. RESULTS Predicted pan- and core-genome sizes were 3416 and 1658 genes, respectively. We found four clusters consisting of CPS genotypes (III, VIII, Ib/VI, and Ia) in the phylogenetic tree. There were significant differences in two metabolic pathways specific to invasiveness, and in six metabolic pathways specific to CPS III type produced by CDSs. CONCLUSION Our observations reveal the pan- and core-genome sizes, four clusters of genomes distributed by CPS genotypes, and unique CDS features of S. agalactiae by comparative genomics in terms of invasiveness and CPS genotype.
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Zhang Z, Li Y, Hu M, Yu A. Genome reanalysis to decipher resistome, virulome, and attenuated characters of attenuated Streptococcus agalactiae strain HZAUSC001. Microb Pathog 2020; 147:104416. [PMID: 32745666 DOI: 10.1016/j.micpath.2020.104416] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 07/11/2020] [Accepted: 07/20/2020] [Indexed: 10/23/2022]
Abstract
Streptococcus agalactiae is a serious pathogen causing severe anthropozoonosis in a broad range of hosts, from aquatic animals to mammals, including humans. S. agalactiae HZAUSC001 was isolated from a moribund tilapia fish exhibiting classic clinical symptoms of streptococcosis in Zhanjiang, Guangdong, China. And it was identified as the etiological factor resulting in fish disease, but was notable because it exhibited attenuated virulence. Here, the genome of S. agalactiae HZAUSC001 was re-analyzed; we assessed the resistome and virulome and deciphered the attenuated characters of HZAUSC001. The S. agalactiae HZAUSC001 genome was assembled into one chromosome with a GC-content of 35.37% and 1972 predicted open reading frames (ORFs). Phylogenetic analysis indicated that it is evolutionarily similar to piscine GBS strains GD201008-001 and ZQ0910. After re-analyzing the published genomic sequence of HZAUSC001, we identified 38 virulence factor genes and one antibiotic-resistance gene. Note that three previously noted virulence genes, bca (C protein alpha-antigen), cpbA (choline-binding protein A) and esp (enterococcal surface protein), were absent in the virulence-attenuated strain S. agalactiae HZAUSC001 but present in the highly virulent strain S. agalactiae GD201008-001. We speculate that the absence of these three virulence genes may be associated with the attenuated traits of the HZAUSC001 strain. Collectively, our study supports that HZAUSC001 may be an excellent candidate for development of an attenuated vaccine, and our results contribute to further understanding of GBS epidemiology and surveillance targets.
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Affiliation(s)
- Ze Zhang
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China; National Institute of Biological Sciences, Zhongguancun Life Science Park, Changping, 102206, Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206, Beijing, China.
| | - Yuhui Li
- Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 430071, China; University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Minqiang Hu
- School of Chemical Biology and Biotechnology, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
| | - Angen Yu
- Department of Aquatic Animal Medicine, Research Center for Marine Biology, College of Fisheries, Huazhong Agricultural University, Wuhan, Hubei, 430070, China
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