Viral diseases of the giant fresh water prawn Macrobrachium rosenbergii: a review

The giant freshwater prawn Macrobrachium rosenbergii is cultivated essentially in Southern and South-eastern Asian countries such as continental China, India, Thailand and Taiwan. To date, only two viral agents have been reported from this prawn. The first (HPV-type virus) was observed by chance 25 years ago in hypertrophied nuclei of hepatopancreatic epithelial cells and is closely related to members of the Parvoviridae family. The second, a nodavirus named MrNV, is always associated with a non-autonomous satellite-like virus (XSV), and is the origin of so-called white tail disease (WTD) responsible for mass mortalities and important economic losses in hatcheries and farms for over a decade. After isolation and purification of these two particles, they were physico-chemically characterized and their genome sequenced. The MrNV genome is formed with two single linear ss-RNA molecules, 3202 and 1250 nucleotides long, respectively. Each RNA segment contains only one ORF, ORF1 coding for the RNA-dependant RNA polymerase located on the long segment and ORF2 coding for the structural protein CP-43 located on the small one. The XSV genome (linear ss-RNA), 796 nucleotides long, contains a single ORF coding for the XSV coat protein CP-17. The XSV does not contain any RdRp gene and consequently needs the MrNV polymerase to replicate.     

Virus diseases of farmed shrimp in the Western Hemisphere (the Americas): a review

Penaeid shrimp aquaculture is an important industry in the Americas, and the industry is based almost entirely on the culture of the Pacific White Shrimp, Litopenaeus vannamei. Western Hemisphere shrimp farmers in 14 countries in 2004 produced more than 200,000 metric tons of shrimp, generated more than $2 billion in revenue, and employed more than 500,000 people. Disease has had a major impact on shrimp aquaculture in the Americas since it became a significant commercial entity in the 1970s. Diseases due to viruses, rickettsial-like bacteria, true bacteria, protozoa, and fungi have emerged as major diseases of farmed shrimp in the region. Many of the bacterial, fungal and protozoan caused diseases are managed using improved culture practices, routine sanitation, and the use of chemotherapeutics. However, the virus diseases have been far more problematic to manage and they have been responsible for the most costly epizootics. Examples include the Taura syndrome pandemic that began in 1991-1992 when the disease emerged in Ecuador, and the subsequent White Spot Disease pandemic that followed its introduction to Central America from Asia in 1999. Because of their socioeconomic significance to shrimp farming, seven of the nine crustacean diseases listed by the World Animal Organization (OIE) are virus diseases of shrimp. Of the seven virus diseases of penaeid shrimp, five are native to the Americas or have become enzootic following their introduction. The shrimp virus diseases in the Americas are increasingly being managed by exclusion using a combination of biosecurity and the practice of culturing domesticated specific pathogen-free (SPF) stocks or specific pathogen-resistant (SPR) stocks. Despite the significant challenges posed by disease, the shrimp farming industry of the Americas has responded to the challenges posed by disease and it has developed methods to manage its diseases and mature into a sustainable industry.     

Sexual selection in hermit crabs: a review and outlines of future research

The information currently available on sexual selection in hermit crabs is reviewed to identify the role of males and females before, during and after mating. According to this information, possible mechanisms of male–male competition, female choice and/or sexual conflict are suggested. Important male components that may affect mating success include dragging the female shell, rotations of the female's shell and male cheliped palpations, and male size and/or shell characteristics (species and size). Possible female determinants of male mating/fertilization success include size (as an indicator of egg production capacity), signalling of sexual receptivity to males, delay from mate guarding to copulation and mating duration. Avenues for deeper exploration in males include the role of the number and morphometry of male sexual tubes during sperm transfer, and whether ejaculate size and sperm number can be adjusted with variable situations of sperm competition intensity and risk. In females it would be interesting to investigate the chemical and behavioural mechanisms affecting spermatophore breakage for sperm release and the variable duration from sperm transfer to spawning. Given these possibilities, and that sperm is externally deposited on the female's body but inside her shell (except for those species that do not use shells, e.g. Birgus , or species where shells are rather small and do not cover the body totally, e.g. Parapagurus ), we conclude that hermit crabs are unique subjects for separating male and female effects, particularly with respect to the applicability of current ideas in sexual selection such as female choice and sexual conflict. Some practical ideas are provided to disentangle both hypotheses using these animals.     

线粒体自噬在感染性疾病中的作用机制研究进展

线粒体自噬作为一种选择性自噬方式是近年研究的热点.细胞通过自噬机制选择性清除受损伤或不必需的线粒体,从而维持其功能稳态.近年来,越来越多的研究聚焦于病原体通过胁迫线粒体自噬在机体感染过程中调节先天免疫信号通路,从而影响感染性疾病的进程.本文分别从线粒体自噬在病毒、细菌和真菌感染性疾病中的作用机制研究进展进行综述,以期为...     

IgY在胃肠感染性疾病中的应用

卵黄抗体（1mmunoglobulinofyolk,IgY）是通过使用特种抗原免疫产蛋鸡,由其卵黄中提取的抗体,与哺乳动物的IgG相似,IgY性质稳定,在控制胃肠道感染性疾病方面存在许多独特的优点,可用于相应疾病的预防和治疗。研究表明,口服特种的IgY对大肠埃希菌、沙门菌、轮状病毒等引起的胃肠感染性疾病可起到免疫保护作用,有望成为抗生素的替代制剂。目前IgY正成为生物技术领域和医药研究中的新热点。     

单细胞测序技术在传染病及微生物领域的应用研究进展

单细胞测序技术正逐渐成为生物学基础研究的“必备工具”,为我们理解各种生物学现象带来革命性的洞见。很多传染性疾病均涉及免疫细胞的差异化功能,而这些免疫细胞之间具有较大的异质性。与传统的批量高通量测序相比,近年来新兴的单细胞转录组测序使得研究者能够分析感染过程的免疫细胞异质性,充分挖掘珍贵的临床样本的分子信息,还能获取难以培养的病原微生物的遗传信息。本文着重介绍了当前单细胞测序在传染性疾病及病原微生物研究领域中的应用情况,并对其发展前景做了简要展望。     

Emerging zoonotic diseases originating in mammals: a systematic review of effects of anthropogenic land-use change

1. Zoonotic pathogens and parasites that are transmitted from vertebrates to humans are a major public health risk with high associated global economic costs. The spread of these pathogens and risk of transmission accelerate with recent anthropogenic land-use changes (LUC) such as deforestation, urbanisation, and agricultural intensification, factors that are expected to increase in the future due to human population expansion and increasing demand for resources.
2. We systematically review the literature on anthropogenic LUC and zoonotic diseases, highlighting the most prominent mammalian reservoirs and pathogens, and identifying avenues for future research.
3. The majority of studies were global reviews that did not focus on specific taxa. South America and Asia were the most-studied regions, while the most-studied LUC was urbanisation. Livestock were studied more within the context of agricultural intensification, carnivores with urbanisation and helminths, bats with deforestation and viruses, and primates with habitat fragmentation and protozoa.
4. Research into specific animal reservoirs has improved our understanding of how the spread of zoonotic diseases is affected by LUC. The behaviour of hosts can be altered when their habitats are changed, impacting the pathogens they carry and the probability of disease spreading to humans. Understanding this has enabled the identification of factors that alter the risk of emergence (such as virulence, pathogen diversity, and ease of transmission). Yet, many pathogens and impacts of LUC other than urbanisation have been understudied.
5. Predicting how zoonotic diseases emerge and spread in response to anthropogenic LUC requires more empirical and data synthesis studies that link host ecology and responses with pathogen ecology and disease spread. The link between anthropogenic impacts on the natural environment and the recent COVID-19 pandemic highlights the urgent need to understand how anthropogenic LUC affects the risk of spillover to humans and spread of zoonotic diseases originating in mammals.