Epidemiological Predicting of the Fleas on Rattus norvegicus

[Objective]To predict prevalence of fleas via a simple epidemiological model.[Method]The field investigation was carried out in 23 locations in Yunnan Province.A simple epidemiological model was involved mean abundance and variance of abundance.[Result]The prevalence of fleas increased with their mean abundance in logistic curve.A linear correlation of the predicted prevalence against observed prevalence did not differ significantly from unity.[Conclusion]Prevalence could be explained simply by their mean abundance.

Isolation of Kytococcus schroeteri from the brown rat Rattus norvegicus

Rodents such as Rattus rattus and Rattus norvegicus have adapted to living close to human settlements[1].This presents a public health challenge as these rodents are considered as pests that can transmit a number of zoonotic diseases to humans[1,2].A rodent surveillance programme was initiated between the years 2014 and 2015,focusing on rodents captured at wet markets where there is abundant food and considerable human traffic.The present study was conducted in several wet markets in Kuala Terengganu,Malaysia(5.3333°N,103.1500°E).

RNA Interference-Mediated Downregulation of sAC Gene Inhibits Sperm Hyperactivation in Male Rats(Rattus norvegicus)

Hyperactivation is one of the most critical parts for fertilization, cAMP generated by soluble adenylyl cyclase （sAC） is necessary to activate sperm and is a prerequisite for sperm hyperactivation. The aim of this study is to investigate the function of sAC in hyperactivation in male rats. Four siRNAs of sAC gene were designed and separately transformed into rat sperm using electrotransformation method. Cultured for 12 and 24 h, physiological and biochemical indexes of these sperm were analyzed, and the expressions of some hyperactivation-related genes were detected using real-time PCR. We demonstrated 26.3-30.8% and 49.1-50.5% reduction in sAC at the protein by Western blot and mRNA levels by real-time PCR, respectively. The results showed that two siRNAs, Actb-717 and Actb-4205, were the best RNAi sites for silencing sAC. The VCL （curvilinear velocity） and ALH （amplitude of lateral head displacement） of RNA interference （RNAi）-transfected sperm were reduced, cAMP and protein phosphorylation in RNAi transfected sperm were also decreased. The hyperactivation-related genes, such as CatSper2, LDHC and PKA, were downregulated in the sperm, which sAC was knockdown. These findings demonstrated that sAC might play a critical role in cAMP signaling in the rat sperm hyperactivation, and downregulated sAC gene might prevent the expression of these hyperactivation-ralated genes resulting in sperm dysfunction. These findings suggest that these hyperactivation-ralated genes and sAC are functionally related in sperm hyperactivation and sAC falls into an expanding group of sperm proteins that appear to be promising targets for the development of male contraceptives.

珠江三角洲黄毛鼠(Rattus rattoides exiguus)天敌食性的初步观察

农田鼠害生物防治的可行性是人们非常关心的问题,也是鼠害综合防治的一个重要环节。本文着重从食性入手,观察研究了珠江三角洲黄毛鼠天敌滑鼠蛇的食性,以及其摄食量与温度、湿度的关系;并且还对黄毛鼠的另一类天敌(号鸟)类的食量情况作了初步观察。提出了对天敌在黄毛鼠生物防治的作用应采取一分为二的态度,一方面不宜过高估计其灭鼠作用,另一方面也应禁止捕捉鼠类天敌,保护其生活环境,维持生态平衡。

Pitx2 suppression at meiotic stages associates with seasonal inhibition of testis development in Rattus norvegicus caraco

The bicoid-related transcription factor 2(Pitx2)plays a crucial role in the development of many organs and tissues by affecting the mitotic cell cycle.Postnatal testis development is related to mitosis and meiosis in mul-tiple cell types,but the role of Pitx2 gene in seasonal inhibition of testicular development remains unknown in rodents.We analyzed PITX2 protein and Pitx2 mRNA expression features using both laboratory and wild male Rattus norvegicus caraco.In postnatal testicle of laboratory colony,we found that PITX2 was expressed in Leydig cells,pachytene spermatocytes,round spermatids,and elongating spermatids rather than spermatogonia and lep-totene/zygotene spermatocytes.Pitx2b expression significantly increased along with the occurrence of pachytene spermatocytes and round spermatids,while decreased along with the processes of elongated spermatids.In wild male rats with similar testes weight,a significantly suppressed Pitx2b expression occurred with an active meiotic stage in the inhibited testes in autumn and winter,compared with the normally developing testes in spring and summer.These results indicate that Pitx2b expression suppression plays a crucial role in the seasonal inhibition of testis development.

Molecular Typing of Leptospira interrogans Strains Isolated from Rattus tanezumi in Guizhou Province,Southwest of China

Abstract Objective To identify and type three leptospires isolated from Rattus tanezumi in Guizhou Province by using three molecular techniques （PFGE, MLVA, and MLST）, reveal the molecular characteristic of causative agents of local leptospirosis and evaluate these three molecular methods based on their detection resolution and efficiency. Methods Three Leptospira strains were isolated from the kidney of Rattus tanezumi and cultured with EMJH medium. PFGE, MLVA, and MLST assays were applied to type the three strains isolated from Rattus tanezumi in Guizhou Province. Results PFGE, MLVA, and MLST typing showed that the three leptospiral isolates matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai. The findings of the genotyping methods were consistent. MLVA and MLST defined genotypes, whereas PFGE allowed the recognition of additional subgroups within the genotypes, and the findings of molecular typing were also consistent with those of traditional techniques. Conclusion Three leptospiral isolates from Guizhou Province matched with leptospiral serogroup Icterohaemorrhagiae serovar Lai, and PFGE, MLVA, and MLST, as reliable molecular techniques for identifying and typing of Leptospira interrogans, would contribute to the active surveillance, outbreak investigation and source tracking for leptospirosis in Guizhou Province.

How many species of Apodemus and Rattus occur in China？ A survey based on mitochondrial cyt b and morphological analyses

Apodemus （mice） and Rattus （rats） are the top rodent reservoirs for zoonoses in China,yet little is known about their diversity.We reexamined the alpha diversity of these two genera based on a new collection of specimens from China and their cyt b sequences in GenBank.We also tested whether species could be identified using external and craniodental measurements exclusively.Measurements from 147 specimens of Apodemus and 233 specimens of Rattus were used for morphological comparisons.We analysed 74 cyt b sequences of Apodemus and 100 cyt b sequences of Rattus to facilitate phylogenetic estimations.Results demonstrated that nine species of Apodemus and seven species of Rattus,plus a new subspecies of Rattus nitidus,are distributed in China.Principal component analysis using external and craniodental measurements revealed that measurements alone could not separate the recognized species.The occurrence of Rattus pyctoris in China remains uncertain.

Sequence Divergence of Mitochondrial 12S rRNA Gene and Phylogenetic Relationship Between Rattus rattus Sladeni and Rattus rattus Hainanicus

The appearance and hair color between these two subspecies Rattus rattus Sladeni and R.r. Hainanicus are similar to each other. Their most major distinctive characteristic is the length ratio of tail to body. However, this characteristic was unstable in some measuring records. In Guangdong, R.r. Hainanicus is restrictedly distributed in the west region, and R.r. Sladeni is widely distributed in the other regions of this province. In this study, we detected the sequences of mitochondrial 12S rRNA gene fragments of 9 samples from R.r. Hainanicus and R.r. Sladeni (Longmen and Hong Kong populations). These 385 nucleotide positions of 12S rRNA gene fragment include 26 variable sites and 14 parsimony-informative sites. 3 insertion/deletion sites are observed. The phylogenetic relationships among these samples were constructed by Neighbor-joining and Maximum parsimony methods. The analysis shows that R.r. Hainanicus is more closely relative to the Longmen population of R.r. Sladeni than to the Hong Kong population of R.r. Sladeni. The sequencing analysis of 12S rRNA gene fragments is not agreement on the classification of subspecies R. r. Hainanicus inferred from the morphology and geographical distribution. The morphological variation of R.r. Hainanicus should result from the natural selection, which causes local adaptation and geographic isolation.

小家鼠(Mus musculus)和褐家鼠(Rattus norvegicus)的化石材料与早期迁徙

小家鼠和褐家鼠在小型啮齿动物中是现今世界上与人类关系最为密切、分布最为广泛的种类。动物学界认为,这2种鼠科动物均起源于中国,然后随着人类活动进行迁徙,逐步扩散到现今世界上所有人类活动区域。由于这2种鼠科动物化石研究材料稀少,以前在古生物或兽类研究中,还缺少对这2种动物从进化方面进行专门研究。本文综合此前中国已报道的小家鼠和褐家鼠化石材料,对它们的早期出现、体质形态变化与迁徙现象等进行探讨。

Reproductive ecology of the black rat (Rattus rattus) in Madagascar: the influence of density-dependent and -independent effects

The black rat(Rattus rattus)poses a severe threat to food security and public health in Madagascar,where it is a major cause of pre-and post-harvest crop losses and an important reservoir for many zoonotic diseases,including plague.Elsewhere,ecologically based rodent management(EBRM)strategies have been developed using ecologi-cal information to inform decisions on where and when to target control.EBRM could deliver improved health and well-being outcomes in Madagascar if adapted to the local ecological context.Using data collected from removal studies,we explored spatio-temporal patterns in the breeding activity of the black rat(R.rattus)in domestic and agricultural habitats across Madagascar and investigated to what extent these trends are influenced by rainfall and rat density.We identified clear spatio-temporal variation in the seasonality of R.rattus reproduction.Reproduction was highly seasonal both inside and outside of houses,but seasonal trends varied between these two habitats.Sea-sonal trends were explained,in part,by variation in rainfall;however,the effect of rainfall on reproductive rates did itself vary by season and habitat type.A decline in breeding intensity with increasing rat density was recorded outside of houses.This has important implications for control,as populations may compensate for removal through increased reproduction.We recommend that sustained control initiated before the main breeding season,combined with improved hygiene and adequate rodent-proofing in homes and grain stores,could curtail population growth and reduce pre-and post-harvest losses provided that these measures overcome the compensatory response of rodent populations.

Antifertility effects of EP-1 (quinestrol and levonorgestrel) on Pacific rats (Rattus exulans)

Pest rodents pose a serious threat to island biodiversity.Fertility control could be an alternative approach to control the impact of rodents on these islands.In this study,we examined the antifertility effects of EP-1 baits containing quinestrol(E)and levonorgestrel(P)using a dose of 50 ppm E and P at three different ratios(E:P ratio=1:2,1:1,and 2:1)on Pacific rats(Rattus exulans)in the Xisha Islands,Hainan,China.Compared to the control group,all animals in EP-1 treatment groups showed significantly decreased food intake and body weight.In treated males,there were obvious abnormalities in testis structure and a significant decrease of relative seminal vesicle weight,but no significant effect on relative uterine and ovarian weights(g kg-1 body weight),or ovarian structure in females.Adding 8%sucrose to the original 50-ppm baits(E:P ratio=1:1)significantly increased bait palatability for males and females.This dose induced uterine edema and abnormalities of ovarian structure in females but had no significant negative effect on the relative testis,epididymis,and seminal vesicle weights(g kg-1 body weight)or sperm density in males.In summary,50-ppm EP-1(1:1)baits have the potential to disrupt the fertility of females,and 8%sucrose addition to the EP-1 baits(E:P ratio=1:1)could improve bait palatability.This dose disrupted the testis structure in males.Future studies are needed to improve bait acceptance and assess the antifertility effects of EP-1(1:1)on Pacific rats in captive breeding trials and underfield conditions.

Efficacy of anticoagulant-free alternative bait products against house mice(Mus musculus)and brown rats(Rattus norvegicus)

The attractiveness and efficacy of four anonymous anticoagulant-free alternative rodenticides(active ingredients cellulose or plaster)were tested on wild strain groups of house mice(Mus musculus Linnaeus)and brown rats(Rattus norvegicus Berkenhout)in laboratory choice and no-choice experiments.In no-choice tests,the rodenticide product was offered ad libitum to the animals for 21 days(mice)and 10 days(rats),respectively.In choice tests,the rodenticide product and non-poisoned food were offered for 28 days(mice)and 14 days(rats).Two products with cellulose(C1 and C2)as the active ingredient were tested against both mice and rats.In two no-choice tests with mice,all animals died within 14 days(C1)and 21 days(C2);in a third no-choice test,11%(2/18)of mice survived(C1:21 days).In all three tests,numerous incidents of cannibalism were observed.The attractiveness of cellulose baits was tested for one product(C1)in three trials against normal food pellets.In all trials,bait consumption was low and all mice survived(15-34 days).Two no-choice trials with cellulose baits(C1)were conducted on groups of Rattus norvegicus;11 of 12 rats survived the bait feeding period and no cannibalism or sign of aggression between conspecifics was observed.Two plaster-based(CaSO_(4)·0.5H_(2)O)products(P1 and P2)were tested against both mice and rats;in no-choice tests,only one mouse(n=20)and no rats(n=8)were killed,although the baits proved to be attractive for rats and mice in choice tests.The results of these experiments suggest that neither cellulose-based nor plaster-based rodenticides are suitable agents for the control of Mus musculus and Rattus norvegicus.

A global overview of the most important zoonotic bacteria pathogens transmitted from Rattus norvegicus to humans in urban environments

Zoonotic pathogens,comprising over 61%of all pathogenic microorganisms,can be transmitted from different animals to individuals in numerous ways either in the presence or the absence of a vector.Causing new emerging human infectious diseases,these pathogens could be categorized into 4 groups,bacteria,viruses,parasites,and fungi.Among the wide range of reservoirs for zoonotic pathogens,tremendous attention has been attracted to wild rats,due to their global distribution not only in urban environments but also in the sylvatic and agricultural surroundings.For the nonce,zoonotic bacteria transmitted via wild rats have turned into a global public health problem probably due to their ability to induce re-emerging diseases even after eradication and controlling man-agement.Despite the importance of wild rats in spreading pathogens,little data are available about the bacterial diversity present in urban wild rat populations.In this review,we present a complete list of zoonotic bacterial pathogens isolated from wild rats in urban environments.

大鼠在医学实验中的应用

现在所用的大鼠,几乎全部来自挪威种(Rattus Norvegicus)。一般认为这种大鼠最早生活于西伯利亚的贝加尔湖,以及东欧的里海和特伯尔斯克(Tocolsk)之间的地带。18世纪,随着贸易发展该鼠传播至整个欧洲和美国。19世纪中叶,该种鼠广泛用于解剖学、生理学及营养学等方面的研究。20世纪初,H·H Donaldson等培育了第一代近交系大鼠,并由其同事用于遗传学和癌症的研究。目前大鼠常用于如下几方面研究。 1、在器官移植方面当今实验性移植研究主要从四个方面进行。即:小肠、心脏和肝脏的同种动物间移植;神经组织移植,异种动物间皮肤移植;生殖研究等。这些方面,大鼠是主要的实验对象。

珠江三角洲主要害鼠染色体分类的研究

本文对珠江三角洲主要害鼠的5个种以及种内有明显变异的群体的染色体组型进行研究,从染色体组型的角度探讨这些动物的分类地位。在本项研究的3个属的动物中,Y染色体均为末端着丝粒染色体,说明这些动物的Y染色体具有同源性,是科内动物的共同特征。 Mus和Bandicota两个属中2n、NF和常、X染色体形态都具有明显的区别,基本证实了目前主要根据形态学所确定的这两个属的分类系统。但Rattus属中各种动物的NF及X染色体形态有差异。小家鼠与小田鼠的核型分析结果表明,它们更可能是不同的亚种。黑型褐家型与褐型褐家鼠的核型有明显差异,很可能分化为不同的种。黄毛鼠与褐家鼠(褐型)的核型相同,值得进一步研究。

大鼠UQCRFS1基因的克隆及其表达模式分析

通过克隆获得泛醌-细胞色素C还原酶铁硫蛋白亚基1(Ubiquinol-cytochrome C reductase iron-sulfur subunit 1,UQCRFS1)基因,对基因序列及其编码的蛋白质进行分析,研究了其在大鼠(Rattusnorvegicus)心、脑、肾、肺组织中的表达模式。测序结果显示UQCRFS1基因全长826 bp,RT-PCR结果显示其在大鼠心脏中表达量较高,脑和肺中表达量稍低,肾脏组织中表达量最低,推测UQCRFS1的功能可能与大鼠的心脏发育有关。

Survey of Angiostrongylus cantonensis in rats and giant African land snails in Phitsanulok province,Thailand

Objective:To survey the Angiostrongylus cantonensis(A.cantonensis) or the rat lungworm in a rat,definitive host,and in a giant African land snail(Achatina fulica),the intermediate host,in Phitsanulok,Thailand.Methods:Rats and giant African land snails were captured from Tha Pho sub-district,Phitsanulok,Thailand.Rats were killed and examined for adult A.cantonensis. The artificial digestion method following Baermann technique were used for isolation third stage larvae of A.cantonensis.Results:Sixty-two rats were captured and they were identified as Rattus argentiventer,Rattus rattus(R.rattus),Bandicota savilei,and Bandicota indica but only one animal(R.rattus) of 62 rats(1.61%) was positive with adult worm of A.cantonensis.The third stage larvae of A.cantonensis were examined on 307 Angiostrongylus fulica snails.It was found that the overall infection rate was 12.38%(38 infected out of 307 Achatina snails).Conclusions: This study demonstrates that A.cantonensis is available in the natural hosts of Phitsanulok.This suggests that the transmissions of this parasite to human may occur in this region.

褐家鼠与大仓鼠消化系统比较

为了解褐家鼠(Rattus norvegicus)与大仓鼠(Cricetulus triton)消化系统之间的差异,试验对两种鼠进行解剖。结果表明,褐家鼠食管平均长度占体长比值是大仓鼠的0.873倍;胃(不含内容物)的平均质量占体重比值是大仓鼠的0.462倍;小肠平均长度占体长的比值是大仓鼠的1.557倍,大肠平均长度占体长比值是大仓鼠的0.383倍,盲肠平均长度占体长比值是大仓鼠的0.283倍;肝重与体重比值是大仓鼠的1.190倍。两种鼠的消化系统中器官长度和结构有多处差异,两种鼠对于食物质量选择的分化程度明显,且褐家鼠食物选择广泛,大仓鼠对植物性食物依赖性更高。

Biochemical and histopathological profiling of Wistar rat treated with Brassica napus as a supplementary feed

Metabolic changes together with cardiovascular and hepatic factors are related to the development of diseases like myocardial lipidosis,heart disease,and profound toxicity.The aim of this animal study is to determine the effects of high erucic acid containing rapeseed oil(Brassica napus L.)varieties on liver,kidney and heart muscles in Wistar rats.Male Wistar rats were divided into three groups where each group containing four rats.Group A was considered as control diet group,while Group B rapeseed wild oil group and Group C rapeseed hybrid oil group were considered as experimental diet groups.The levels of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),creatine kinase-MB(CK-MB)and creatinine of two experimental groups were significantly elevated while compared to the control groups(p<0.05–0.001).Nevertheless,an increment in weight retardation(p<0.05)was also observed in rapeseed hybrid oil treated groups.No significant weight retardation found in other two groups(p>0.05).Noticeable tissue injury observed in this study is a sign of the relative toxicity of erucic acid containing rapeseed oil to mammalian species.The use of Brassica napus as a supplementary feed ingredient should be,therefore,thoroughly considered.

The antioxidative effects of some medicinal plants as hypoglycemic agents on chromosomal aberration and abnormal nucleic acids metabolism produced by diabetes stress in male adult albino rats

The objectives of the present study are to evaluate the chromosomal aberrations in somatic and germ cells of alloxanized diabetic rats treated with methanolic extracts of Cleome droserifolia (Sammo), Anastatica hierochuntica (Kafta), Juniperus phoencea (Araar) and Hyphaene thebaica (Doum) as well as their effects on blood glucose, liver and testes total soluble protein, DNA and RNA contents and also nucleases (RNAase and DNAase) activity. The material and Methods: The study was performed in six groups. The first group was the normal healthy control;the second group was rats injected with alloxan (diabetic control). Every one of the other four groups (diabetic rats) was ingested with each of the methanolic extracts of Kafta, Doum, Sammo and Araar (individually). The results: The results of chromosomal analysis showed that, diabetic rats had a highly significant increase of chromosomal aberrations compared to that of normal healthy control. Animals which treated with the four plants methanolic extracts showed significant improvements in the frequencies of chromosomal aberrations. In case of biochemical analysis, blood glucose level was significantly increased but immunoglobulins levels were decreased in diabetic albino rats. Diabetes increased serum total lipids, cholesterol, triglycerides and LDL but serum HDL was decreased. RNA and DNA as well as inhibited the nucleases (RNAase and DNAase) activity of both organs (liver and testes) tissue. The conclusions: It is concluded that diabetes is much harmful in the animal body, whilst the induction of flavonoids extract (by methanol) of Kafta, Somma, Araar and Doum reduced these harmful of diabetes.