scholarly journals Investigations on Vector-Borne and Aerosol Transmission Potential of Kaeng Khoi Virus in Cave-Dwelling Wrinkle-Lipped Free-Tailed Bats (Chaerephon plicatus) in Thailand

2021 ◽  
Vol 9 (10) ◽  
pp. 2022
Author(s):  
William A. Neill ◽  
Rebekah C. Kading
Keyword(s):  
Viral Infection ◽  
Neutralizing Antibodies ◽  
Rattus Rattus ◽  
Laboratory Mice ◽  
Experimental Transmission ◽  
Transmission Potential ◽  
Animal Populations ◽  
Vector Borne ◽  
Transmission Studies ◽  
Viral Isolates

Kaeng Khoi virus (KKV; Order: Bunyavirales, Family: Peribunyaviridae, Genus: Orthobunyavirus), is an endemic viral infection of the wrinkle-lipped free-tailed bat (Chaerephon plicatus; also known as Tadarida plicata plicata). Viral isolates from bat bugs (Family: Cimicidae) suggest vector-borne transmission, but in general little is known about the ecology of KKV and seroprevalence in the local human and animal populations. Transmission studies and a serosurvey were carried out in Kaeng Khoi cave, Saraburi province, Thailand, during 1973–1974. Experimental transmission studies were performed with bat bugs captured within the cave to determine the potential for vector-borne transmission, and sentinel laboratory mice placed inside arthropod-proof cages within the cave to assess the potential for aerosolized transmission. Antibodies to KKV were detected in roof rats (Rattus rattus) inhabiting the cave, in dogs living in the valley, and in humans. Freshly collected cimicids were positive for KKV, but the virus did not replicate in laboratory-inoculated bugs. Sentinel mice placed in Kaeng Khoi cave in open cages consistently became infected with KKV, as determined by the development of neutralizing antibodies. Mice placed in arthropod-proof cages also developed antibodies, indicating the possibility of airborne transmission of KKV.

SARS-CoV-2 Biology Insights, Part IV.Antibody-Dependent Enhancement (ADE) and the tricky “Herd Immunity”: narrative review (Preprint)

2020 ◽  
Author(s):  
Laura Lafon-Hughes
Keyword(s):  
Viral Infection ◽  
Viral Entry ◽  
Neutralizing Antibodies ◽  
Vaccine Development ◽  
Whooping Cough ◽  
Common Knowledge ◽  
Herd Immunity ◽  
Life Quality ◽  
Host Cells ◽  
System P

BACKGROUND It is common knowledge that vaccination has improved our life quality and expectancy since it succeeded in achieving almost eradication of several diseases including chickenpox (varicella), diphtheria, hepatitis A and B, measles, meningococcal, mumps, pneumococcal, polio, rotavirus, rubella, tetanus and whooping cough (pertussis) Vaccination success is based on vaccine induction of neutralizing antibodies that help fight the infection (e.g. by a virus), preventing the disease. Conversely, Antibody-dependent enhancement (ADE) of a viral infection occurs when anti-viral antibodies facilitate viral entry into host cells and enhance viral infection in these cells. ADE has been previously studied in Dengue and HIV viruses and explains why a second infection with Dengue can be lethal. As already reviewed in Part I and Part II, SARS-Cov-2 shares with HIV not only 4 sequences in the Spike protein but also the capacity to attack the immune system. OBJECTIVE As HIV presents ADE, we wondered whether this was also the case regarding SARS-CoV-2. METHODS A literature review was done through Google. RESULTS SARS-CoV-2 presents ADE. As SARS, which does not have the 4 HIV-like inserts, has the same property, ADE would not be driven by the HIV-like spike sequences. CONCLUSIONS ADE can explain the failure of herd immunity-based strategies and will also probably hamper anti-SARS-CoV-2 vaccine development. As reviewed in Part I, there fortunately are promising therapeutic strategies for COVID-19, which should be further developed. In the meantime, complementary countermeasures to protect mainly the youth from this infection are presented to be discussed in Part V Viewpoint.

scholarly journals Hemotropic Mycoplasma and Bartonella Species Diversity in Free-Roaming Canine and Feline from Luanda, Angola

Pathogens ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 735
Author(s):  
João R. Mesquita ◽  
Ana C. Oliveira ◽  
Frederico Neves ◽  
Jose R. Mendoza ◽  
Maria F. Luz ◽  
...  
Keyword(s):  
Population Control ◽  
Small Sample Size ◽  
Bartonella Henselae ◽  
Control Program ◽  
Health Impact ◽  
Small Sample ◽  
Stray Cats ◽  
Hemotropic Mycoplasma ◽  
Animal Populations ◽  
Vector Borne

Free-roaming dogs and cats represent potential reservoirs for zoonotic vector-borne pathogens shedding to the human population. Given the health impact of these pathogens, we searched free-roaming dogs and cats included in an animal population control program from Luanda, Angola, for Bartonella and hemotropic mycoplasma infection. We report the detection of Bartonella henselae (2/66; 3%), Candidatus Mycoplasma haemominutum (5/66; 7.5%) and Mycoplasma haemofelis (1/66; 1.5%) in cats. One dog was found positive for Mycoplasma haemocanis (1/20; 5%). This is the first report of Bartonella henselae infections in stray cats and of hemotropic mycoplasmas in cats and dogs from Angola. Despite the relatively small sample size, our results sustain the hypothesis of uncontrolled circulation of these agents in highly mobile synanthropic animal populations of Luanda. Population and vector control could contribute to reducing the likelihood for animal-to-animal and animal-to-human transmission.

scholarly journals Rickettsia typhi IN RODENTS AND R. felis IN FLEAS IN YUCATÁN AS A POSSIBLE CAUSAL AGENT OF UNDEFINED FEBRILE CASES

2015 ◽  
Vol 57 (2) ◽  
pp. 129-132 ◽  
Author(s):  
Gaspar PENICHE-LARA ◽  
Karla DZUL-ROSADO ◽  
Carlos PÉREZ-OSORIO ◽  
Jorge ZAVALA-CASTRO
Keyword(s):  
Rattus Rattus ◽  
Conventional Polymerase Chain Reaction ◽  
Causal Agent ◽  
Wild Rodents ◽  
Murine Typhus ◽  
Rickettsia Typhi ◽  
Rickettsia Felis ◽  
Vector Borne ◽  
Polymerase Chain ◽  
First Time

Rickettsia typhi is the causal agent of murine typhus; a worldwide zoonotic and vector-borne infectious disease, commonly associated with the presence of domestic and wild rodents. Human cases of murine typhus in the state of Yucatán are frequent. However, there is no evidence of the presence of Rickettsia typhi in mammals or vectors in Yucatán. The presence of Rickettsia in rodents and their ectoparasites was evaluated in a small municipality of Yucatán using the conventional polymerase chain reaction technique and sequencing. The study only identified the presence of Rickettsia typhi in blood samples obtained from Rattus rattus and it reported, for the first time, the presence of R. felis in the flea Polygenis odiosus collected from Ototylomys phyllotis rodent. Additionally, Rickettsia felis was detected in the ectoparasite Ctenocephalides felis fleas parasitizing the wild rodent Peromyscus yucatanicus. This study’s results contributed to a better knowledge of Rickettsia epidemiology in Yucatán.

Transplantation of Adult Dirofilaria roemeri to Grey Kangaroos and Laboratory Rats

1972 ◽  
Vol 46 (1) ◽  
pp. 81-89 ◽  
Author(s):  
David M. Spratt
Keyword(s):  
Aedes Aegypti ◽  
Peritoneal Lavage ◽  
Natural Infection ◽  
Experimental Transmission ◽  
Laboratory Rats ◽  
Saphenous Veins ◽  
Large Numbers ◽  
Grey Kangaroo ◽  
Transmission Studies ◽  
Excellent Source

Adult Dirofilaria roemeri were transplanted subcutaneously into two grey kangaroos and intraperitoneally into seven laboratory rats in an investigation of amicrofilaraemia, and for experimental transmission studies. Low level blood microfilaraemias of only short duration were produced in all but one rat, supporting the hypothesis that the grey kangaroo is an abnormal host of this parasite. Cortisone was instrumental in the success of D. roemeri in rats. Peritoneal lavage of rats harbouring transplanted D. roemeri proved an excellent source of microfilariae. Injection of large numbers of microfilariae into the saphenous veins of rats harbouring transplanted worms failed to alter the number of circulating microfilariae. D. roemeri failed to develop in Aedes aegypti, fed on rats harbouring transplanted worms and exhibiting blood microfilaraemia. One kangaroo, to which worms had been transplanted, was exposed to the bites of Dasybasis hebes (Diptera, Tabanidae) in the study area and acquired a natural infection of D. roemeri.

scholarly journals Cure of Chronic Viral Infection and Virus-Induced Type 1 Diabetes by Neutralizing Antibodies

2006 ◽  
Vol 13 (1) ◽  
pp. 67-77 ◽  
Author(s):  
Mette Ejrnaes ◽  
Matthias G. von Herrath ◽  
Urs Christen
Keyword(s):  
Type 1 Diabetes ◽  
Viral Infection ◽  
Inflammatory Mediators ◽  
Neutralizing Antibodies ◽  
Chronic Viral Infection ◽  
Negative Consequences ◽  
Ligand Interactions ◽  
The Right

The use of neutralizing antibodies is one of the most successful methods to interfere with receptor–ligand interactions in vivo. In particular blockade of soluble inflammatory mediators or their corresponding cellular receptors was proven an effective way to regulate inflammation and/or prevent its negative consequences. However, one problem that comes along with an effective neutralization of inflammatory mediators is the general systemic immunomodulatory effect. It is, therefore, important to design a treatment regimen in a way to strike at the right place and at the right time in order to achieve maximal effects with minimal duration of immunosuppression or hyperactivation. In this review, we reflect on two examples of how short time administration of such neutralizing antibodies can block two distinct inflammatory consequences of viral infection. First, we review recent findings that blockade of IL-10/IL-10R interaction can resolve chronic viral infection and second, we reflect on how neutralization of the chemokine CXCL10 can abrogate virus-induced type 1 diabetes.

scholarly journals Pluripotency of Wolbachia against Arboviruses: the case of yellow fever

2019 ◽  
Vol 3 ◽  
pp. 161 ◽  
Author(s):  
Marcele Neves Rocha ◽  
Myrian Morato Duarte ◽  
Simone Brutman Mansur ◽  
Bianca Daoud Mafra e Silva ◽  
Thiago Nunes Pereira ◽  
...  
Keyword(s):  
Yellow Fever ◽  
Yellow Fever Virus ◽  
Oral Feeding ◽  
Risk Of Infection ◽  
Wild Type ◽  
Transmission Potential ◽  
Mosquito Saliva ◽  
Tropical Cities ◽  
Complementary Strategy ◽  
Viral Isolates

Background: Yellow fever outbreaks have re-emerged in Brazil during 2016-18, with mortality rates up to 30%. Although urban transmission has not been reported since 1942, the risk of re-urbanization of yellow fever is significant, as Aedes aegypti is present in most tropical and sub-tropical cities in the World and still remains the main vector of urban YFV. Although the YFV vaccine is safe and effective, it does not always reach populations at greatest risk of infection and there is an acknowledged global shortage of vaccine supply. The introgression of Wolbachia bacteria into Ae. aegypti mosquito populations is being trialed in several countries (www.worldmosquito.org) as a biocontrol method against dengue, Zika and chikungunya. Here, we studied the ability of Wolbachia to reduce the transmission potential of Ae. aegypti mosquitoes for Yellow fever virus (YFV). Methods: Two recently isolated YFV (primate and human) were used to challenge field-derived wild-type and Wolbachia-infected (wMel +) Ae. aegypti mosquitoes. The YFV infection status was followed for 7, 14 and 21 days post-oral feeding (dpf). The YFV transmission potential of mosquitoes was evaluated via nano-injection of saliva into uninfected mosquitoes or by inoculation in mice. Results: We found that Wolbachia was able to significantly reduce the prevalence of mosquitoes with YFV infected heads and thoraces for both viral isolates. Furthermore, analyses of mosquito saliva, through indirect injection into naïve mosquitoes or via interferon-deficient mouse model, indicated Wolbachia was associated with profound reduction in the YFV transmission potential of mosquitoes (14dpf). Conclusions: Our results suggest that Wolbachia introgression could be used as a complementary strategy for prevention of urban yellow fever transmission, along with the human vaccination program.

scholarly journals A Multiepitope Fusion Antigen Elicits Neutralizing Antibodies against Enterotoxigenic Escherichia coli and Homologous Bovine Viral Diarrhea VirusIn Vitro

2013 ◽  
Vol 20 (7) ◽  
pp. 1076-1083 ◽  
Author(s):  
Emad A. Hashish ◽  
Chengxian Zhang ◽  
Xiaosai Ruan ◽  
David E. Knudsen ◽  
Christopher C. Chase ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Viral Infection ◽  
Neutralizing Antibodies ◽  
Cell Epitope ◽  
Enterotoxigenic Escherichia Coli ◽  
Bovine Viral Diarrhea ◽  
Content Type ◽  
Diarrhea Virus ◽  
Viral Diarrhea ◽  
Fusion Antigen

ABSTRACTDiarrhea is one of the most important bovine diseases. EnterotoxigenicEscherichia coli(ETEC) and bovine viral diarrhea virus (BVDV) are the major causes of diarrhea in calves and cattle. ETEC expressing K99 (F5) fimbriae and heat-stable type Ia (STa) toxin are the leading bacteria causing calf diarrhea, and BVDV causes diarrhea and other clinical illnesses in cattle of all ages. It is reported that maternal immunization with K99 fimbrial antigens provides passive protection to calves against K99 fimbrial ETEC and that BVDV major structural protein E2 elicits antibodies neutralizing against BVDV viral infection. Vaccines inducing anti-K99 and anti-STa immunity would protect calves more effectively against ETEC diarrhea, and those also inducing anti-E2 neutralizing antibodies would protect calves and cattle against diarrhea caused by both ETEC and BVDV. In this study, we used the ETEC K99 major subunit FanC as a backbone, genetically embedded the STa toxoid STaP12Fand the most-antigenic B-cell epitope and T-cell epitope predicted from the BVDV E2 glycoprotein into FanC for the multivalent antigen FanC-STa-E2, and examined immunogenicity of this multivalent antigen to assess vaccine potential against bovine diarrhea. Mice intraperitoneally (i.p.) immunized with this multivalent antigen developed anti-K99, anti-STa, and anti-BVDV antibodies. Moreover, elicited antibodies showed neutralization activities, as they inhibited adherence of K99 fimbrialE. coli, neutralized STa toxin, and prevented homologous BVDV viral infectionin vitro. Results from this study suggest that this multiepitope fusion antigen can potentially be developed as a vaccine for broad protection against bovine diarrhea and that the multiepitope fusion strategy may be generally applied for multivalent vaccine development against heterogeneous pathogens.

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