scholarly journals Pathogenicity Analysis of Weaned Piglets Challenged With Novel Emerging Senecavirus A in Fujian, China

2021 ◽  
Vol 8 ◽  
Author(s):  
Cun Liu ◽  
Yanhan Liu ◽  
Xiubo Li ◽  
Lin Liang ◽  
Shangjin Cui
Keyword(s):  
Viral Load ◽  
Intramuscular Injection ◽  
Vaccine Development ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Neutralizing Antibody ◽  
Enzyme Linked Immunosorbent Assay ◽  
Weaned Piglets ◽  
Antibody Levels ◽  
Symptoms And Signs

In order to evaluate the pathogenicity of Senecavirus A (SVA) to weaned piglets preliminarily, 28-day-old weaned piglets were challenged with SVA by intramuscular injection. The clinical manifestations, antibody levels, and tissue viral load of infected piglets were detected. The results indicated that the piglets challenged with SVA CH/FuJ/2017 showed drowsiness, lameness, oral blisters, diarrhea, and other clinical signs. Lesions on the hooves were observed. Red spots or plaques were initially observed on the hoof and then developed into blisters that cracked and gradually formed scab. The symptoms and signs were relieved after 8 days post-infection (dpi). The sentinel piglet, feeding together with the challenged piglets, showed similar clinical signs with the challenged piglets after 3 dpi. Monitoring of antibody levels showed that anti-SVA antibody could be detected at 5 dpi by competition enzyme-linked immunosorbent assay (cELISA) method, and neutralizing antibody could be detected after 7 dpi. Analysis of viral tissue distribution and viral load indicated that SVA could replicate in the liver, spleen, lung, kidney, and lymph node. In all, Senecavirus disease was successfully replicated by SVA CH/FuJ/2017 isolate, which verified the clinical manifestations of SVA infection in weaned piglets, and provided a foundation for further SVA pathogenesis and vaccine development.

ChAd155-RSV vaccine is immunogenic and efficacious against bovine RSV infection-induced disease in young calves

2021 ◽  
Author(s):  
Rineke de Jong ◽  
Norbert Stockhofe-Zurwieden ◽  
Judith Bonsing ◽  
Kai-fen Wang ◽  
Sarah Vandepaer ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Vaccine Candidate ◽  
Clinical Symptoms ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Neutralizing Antibody ◽  
Rsv Infection ◽  
Syncytial Virus ◽  
Tract Disease ◽  
The One

Abstract Respiratory syncytial virus (RSV) infection causes a substantial lower respiratory-tract disease burden in infants, and is a global priority for vaccine development. We evaluated the immunogenicity, safety and efficacy of a chimpanzee adenovirus (ChAd)-based vaccine candidate, ChAd155-RSV, in a bovine RSV (bRSV) challenge model. This model closely reproduces the pathogenesis/clinical manifestations of severe pediatric RSV disease. In seronegative calves, ChAd155-RSV elicited robust neutralizing antibody responses against human RSV. Two doses protected calves from clinical symptoms/lung pathological changes, and reduced nasal/lung virus loads after both a short (4-week) and a long (16-week) interval between the last immunization and a subsequent bRSV challenge. The one-dose regimen also conferred near-complete or significant protection after the short-term or long-term intervals before challenge, respectively. Importantly, immunized calves presented no clinical signs of enhanced respiratory disease. Collectively, the data supported the development of ChAd155-RSV as an RSV vaccine candidate for infants.

scholarly journals IgM and IgA Antibody Responses in 12 Cases of Human Acquired Toxoplasmosis

1997 ◽  
Vol 39 (6) ◽  
pp. 327-332 ◽  
Author(s):  
Emília E. H. TAKAHASHI ◽  
Cláudio L. ROSSI
Keyword(s):  
Serological Test ◽  
Clinical Manifestations ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
Igm Antibodies ◽  
Iga Antibodies ◽  
Direct Elisa ◽  
Acute Toxoplasmosis ◽  
Antibody Levels ◽  
Acquired Toxoplasmosis

The persistence, in some subjects, of specific IgM antibodies to Toxoplasma gondii for several months after the acute phase of infection has complicated the interpretation of serological test results for toxoplasmosis. Several reports have emphasized the value of the detection of Toxoplasma-specific IgA antibodies for the diagnosis of acute toxoplasmosis. In this article, we report the follow-up profiles of Toxoplasma-specific IgM and IgA antibodies in serum samples obtained from 12 patients at various intervals after the onset of the clinical manifestations of infection. IgM antibodies were detected by the indirect immunofluorescence (IIF) test, antibody capture enzyme-linked immunosorbent assay (cELISA) and enzyme-mediated chemilluminescent technique (CmL). IgA antibodies were quantified by the direct ELISA (dELISA) and cELISA procedures. As defined by the manufacturer of the cELISA test for IgA used, most patients with acute toxoplasmosis have antibody levels > 40 arbritary units per ml (AU/ml). At values > 40 AU/ml, the cELISA for IgA detected significant antibody levels for a shorter time than the other techniques used for IgM and IgA detection. However, IgA levels <FONT FACE="Symbol">£</font> 40 AU/ml do not exclude the possibility of acute toxoplasmosis since such levels can be reached very soon after infection with T. gondii. The results obtained in the present study show that the serological diagnosis of acute toxoplasmosis may not be such an easy task. Our data suggest that use of the IgA-cELISA concomitantly with IgM antibody screening could permit, in some circumstances, a more efficient diagnosis of acute acquired toxoplasmosis

scholarly journals Autoimmune thyroiditis: clinical presentation in a Nepalese population

2014 ◽  
Vol 3 (1) ◽  
pp. 44-47
Author(s):  
K Paudel ◽  
B Paudel
Keyword(s):  
Clinical Presentation ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Primary Hypothyroidism ◽  
Cold Intolerance ◽  
Wide Range ◽  
Tingling Sensation ◽  
Pedal Edema ◽  
Antibody Levels ◽  
Hypothyroid Patients

Background: Hypothyroidism has a wide range of clinical presentations. This study was conducted to describe the clinical manifestations of chronic Hashimoto`s thyroiditis (HT) in a Nepalese population. We also tried to identify symptoms or signs characteristic for HT. Methods: During the study period, all newly diagnosed patients with hypothyroidism were interviewed about symptoms, and clinical signs were assessed. The data of hypothyroid patients were divided in two groups: TPO antibody positive and TPO antibody negative. The symptoms and signs of the two groups were analyzed and compared. Results: Among the 88 hypothyroid patients, 33 (37.5%) had positive TPO antibody levels. Female patients were more likely to be TPO antibody positive (41.3% among female and 15.4% among male). The most frequent symptoms were lethargy, cold intolerance, constipation, tingling sensation and weight gain, and the most frequent signs were facial puffiness and non-pitting pedal edema, in both groups. Statistical analysis revealed, that cold intolerance, decreased appetite and insomnia were significantly more prevalent symptoms in the TPO antibody positive group (p<0.05). Conclusion: Hashimoto`s thyroiditis is a common cause of primary hypothyroidism. It is not possible to differentiate it from the clinical presentation. Nepal Journal of Medical Sciences | Volume 03 | Number 01 | January-June 2014 | Page 68-71 DOI: http://dx.doi.org/10.3126/njms.v3i1.10362

scholarly journals Neutralizing Antibody Responses in COVID-19 Convalescent Sera

2020 ◽  
Vol 223 (1) ◽  
pp. 47-55 ◽  
Author(s):  
William T Lee ◽  
Roxanne C Girardin ◽  
Alan P Dupuis ◽  
Karen E Kulas ◽  
Anne F Payne ◽  
...  
Keyword(s):  
Neutralizing Antibodies ◽  
High Titer ◽  
Experimental Treatment ◽  
Neutralizing Antibody ◽  
Maximal Activity ◽  
The United States ◽  
Enzyme Linked Immunosorbent Assay ◽  
United States Food ◽  
Antibody Titers ◽  
Antibody Levels

Abstract Passive transfer of antibodies from COVID-19 convalescent patients is being used as an experimental treatment for eligible patients with SARS-CoV-2 infections. The United States Food and Drug Administration’s (FDA) guidelines for convalescent plasma initially recommended target antibody titers of 160. We evaluated SARS-CoV-2 neutralizing antibodies in sera from recovered COVID-19 patients using plaque reduction neutralization tests (PRNT) at moderate (PRNT50) and high (PRNT90) stringency thresholds. We found that neutralizing activity significantly increased with time post symptom onset (PSO), reaching a peak at 31–35 days PSO. At this point, the number of sera having neutralizing titers of at least 160 was approximately 93% (PRNT50) and approximately 54% (PRNT90). Sera with high SARS-CoV-2 antibody levels (&gt;960 enzyme-linked immunosorbent assay titers) showed maximal activity, but not all high-titer sera contained neutralizing antibody at FDA recommended levels, particularly at high stringency. These results underscore the value of serum characterization for neutralization activity.

scholarly journals Simulation of the Clinical and Pathological Manifestations of Coronavirus Disease 2019 (COVID-19) in a Golden Syrian Hamster Model: Implications for Disease Pathogenesis and Transmissibility

2020 ◽  
Author(s):  
Jasper Fuk-Woo Chan ◽  
Anna Jinxia Zhang ◽  
Shuofeng Yuan ◽  
Vincent Kwok-Man Poon ◽  
Chris Chung-Sing Chan ◽  
...  
Keyword(s):  
Weight Loss ◽  
Viral Load ◽  
Syrian Hamster ◽  
Clinical Signs ◽  
Neutralizing Antibody ◽  
Adaptive Mutation ◽  
Lung Pathology ◽  
Hamster Model ◽  
Golden Syrian Hamster ◽  
Virus Challenge

Abstract Background A physiological small-animal model that resembles COVID-19 with low mortality is lacking. Methods Molecular docking on the binding between angiotensin-converting enzyme 2 (ACE2) of common laboratory mammals and the receptor-binding domain of the surface spike protein of SARS-CoV-2 suggested that the golden Syrian hamster is an option. Virus challenge, contact transmission, and passive immunoprophylaxis studies were performed. Serial organ tissues and blood were harvested for histopathology, viral load and titer, chemokine/cytokine level, and neutralizing antibody titer. Results The Syrian hamster could be consistently infected by SARS-CoV-2. Maximal clinical signs of rapid breathing, weight loss, histopathological changes from the initial exudative phase of diffuse alveolar damage with extensive apoptosis to the later proliferative phase of tissue repair, airway and intestinal involvement with viral nucleocapsid protein expression, high lung viral load, and spleen and lymphoid atrophy associated with marked chemokine/cytokine activation were observed within the first week of virus challenge. The mean lung virus titer was between 105 and 107 TCID50/g. Challenged index hamsters consistently infected naive contact hamsters housed within the same cages, resulting in similar pathology but not weight loss. All infected hamsters recovered and developed mean serum neutralizing antibody titers ≥1:427 14 days postchallenge. Immunoprophylaxis with early convalescent serum achieved significant decrease in lung viral load but not in lung pathology. No consistent nonsynonymous adaptive mutation of the spike was found in viruses isolated from the infected hamsters. Conclusions Besides satisfying Koch’s postulates, this readily available hamster model is an important tool for studying transmission, pathogenesis, treatment, and vaccination against SARS-CoV-2.

Clinical Characteristics of Pediatric Patients with Ocular Toxocariasis in China

2016 ◽  
Vol 235 (2) ◽  
pp. 97-105 ◽  
Author(s):  
Yalu Liu ◽  
Qi Zhang ◽  
Jing Li ◽  
Xunda Ji ◽  
Yu Xu ◽  
...  
Keyword(s):  
Rural Areas ◽  
Clinical Characteristics ◽  
Pediatric Patients ◽  
Age Of Onset ◽  
Age Groups ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Signs And Symptoms ◽  
Enzyme Linked Immunosorbent Assay ◽  
Ocular Toxocariasis

Objective: The aim of the study was to analyze the clinical characteristics of pediatric patients with ocular toxocariasis. Methods: Ocular toxocariasis was diagnosed and treated in 46 children from Shanghai and surrounding provinces. The diagnosis of ocular toxocariasis was confirmed immunologically by performing an enzyme-linked immunosorbent assay on serum and/or intraocular fluid. All pediatric patients and their guardians completed a questionnaire concerning their cases and living habits. Results: The mean age of onset was 6 ± 3 years. Most children (85%) resided in rural areas, and 91% of the children had contact with adult dogs or puppies. At the first visit, visual acuity (VA) was <20/200 in 36 cases, and we detected peripheral granuloma in 36 patients. In our study, the most common signs were vitritis, vitreous strands, and tractional retinal detachment. The Optomap 200Tx device detected granuloma with an 85% sensitivity, which is much higher than that of other techniques. We treated 40 cases (87%) with topical corticosteroids, while 28 patients (61%) were treated with systemic corticosteroids. Only 18 children (39%) required surgical intervention. All patients were examined and treated by the same ophthalmologists. Conclusions: Preschool children in China are more often affected by toxocariasis compared with other age groups. The most common signs included unilateral granuloma and ocular inflammation. In our study, clinical manifestations were severe and complicated. At the first visit, VA was <20/200 in most patients. Ocular toxocariasis was diagnosed on the basis of clinical signs and symptoms; the diagnosis was confirmed by immunological testing. Techniques using the Optomap 200Tx device can facilitate the early detection and lead to better visual prognosis.

scholarly journals A Multicomponent Vaccine Provides Immunity against Local and Systemic Infections by Group A Streptococcus across Serotypes

mBio ◽  
2019 ◽  
Vol 10 (6) ◽  
Author(s):  
Shuai Bi ◽  
Meiyi Xu ◽  
Ya Zhou ◽  
Xinxin Xing ◽  
Adong Shen ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Vaccine Development ◽  
Group A Streptococcus ◽  
Clinical Manifestations ◽  
Enzyme Linked Immunosorbent Assay ◽  
Th17 Response ◽  
Different Types ◽  
Group A ◽  
Large Repertoire ◽  
Multicomponent Vaccine

ABSTRACT Group A streptococcus (GAS) species are responsible for a broad spectrum of human diseases, ranging from superficial to invasive infections, and are associated with autoimmune disorders. There is no commercial vaccine against GAS. The clinical manifestations of GAS infection may be attributable to the large repertoire of virulence factors used selectively in different types of GAS disease. Here, we selected five molecules, highly conserved among GAS serotypes, and involved in different pathogenic mechanisms, as a multicomponent vaccine, 5CP. Intranasal (i.n.) immunization with 5CP protected mice against both mucosal and systemic GAS infection across serotypes; the protection lasted at least 6 months. Immunization of mice with 5CP constrained skin lesion development and accelerated lesion recovery. Flow cytometry and enzyme-linked immunosorbent assay analyses revealed that 5CP induced Th17 and antibody responses locally and systemically; however, the Th17 response induced by 5CP resolved more quickly than that to GAS when challenge bacteria were cleared, suggesting that 5CP is less likely to cause autoimmune responses. These findings support that immunization through the i.n. route targeting multiple nonredundant virulence factors can induce immunity against different types of GAS disease and represents an alternative strategy for GAS vaccine development, with favorable efficacy, coverage, duration, and safety. IMPORTANCE GAS is among the most common human pathogens and causes a wide variety of diseases, likely more than any other microorganism. The diverse clinical manifestations of GAS may be attributable to its large repertoire of virulence factors that are selectively and synergistically involved in streptococcal pathogenesis. To date, GAS vaccines have not been successful due to multiple serotypes and postinfection sequelae associated with autoimmunity. In this study, five conserved virulence factors that are involved in GAS pathogenesis were used as a combined vaccine. Intranasal immunization with this vaccine induced humoral and cellular immune responses across GAS serotypes and protected against mucosal, systemic, and skin infections. The significance of this work is to demonstrate that the efficacy of GAS vaccines can be achieved by including multiple nonredundant critical virulence factors and inducing local and systemic immunity. The strategy also provides valuable insights for vaccine development against other pathogens.

scholarly journals Stable neutralizing antibody levels six months after mild and severe COVID-19 episode

2020 ◽  
Author(s):  
Edwards Pradenas ◽  
Benjamin Trinité ◽  
Víctor Urrea ◽  
Silvia Marfil ◽  
Carlos Ávila-Nieto ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Neutralizing Antibody ◽  
Asymptomatic Infection ◽  
Current Evidence ◽  
Rapid Decline ◽  
Two Phase ◽  
Neutralizing Activity ◽  
Slow Decline ◽  
Antibody Titers ◽  
Antibody Levels

Understanding mid-term kinetics of immunity to SARS-CoV-2 is the cornerstone for public health control of the pandemic and vaccine development. However, current evidence is rather based on limited measurements, thus losing sight of the temporal pattern of these changes1–6. In this longitudinal analysis, conducted on a prospective cohort of COVID-19 patients followed up to 242 days, we found that individuals with mild or asymptomatic infection experienced an insignificant decay in neutralizing activity that persisted six months after symptom onset or diagnosis. Hospitalized individuals showed higher neutralizing titers, which decreased following a two-phase pattern, with an initial rapid decline that significantly slowed after day 80. Despite this initial decay, neutralizing activity at six months remained higher among hospitalized individuals. The slow decline in neutralizing activity at mid-term contrasted with the steep slope of antibody titers change, reinforcing the hypothesis that the quality of immune response evolves over the post-convalescent stage4,5.

scholarly journals Insights on adaptive and innate immunity in canine leishmaniosis

Parasitology ◽  
2016 ◽  
Vol 144 (1) ◽  
pp. 95-115 ◽  
Author(s):  
SHAZIA HOSEIN ◽  
DAMER P. BLAKE ◽  
LAIA SOLANO-GALLEGO
Keyword(s):  
Immune Responses ◽  
Vaccine Development ◽  
Systemic Disease ◽  
Clinical Signs ◽  
Clinical Manifestations ◽  
Canine Leishmaniosis ◽  
Subclinical Infection ◽  
Adaptive Immune ◽  
Future Direction ◽  
Severe Systemic Disease

SUMMARYCanine leishmaniosis (CanL) is caused by the parasiteLeishmania infantumand is a systemic disease, which can present with variable clinical signs, and clinicopathological abnormalities. Clinical manifestations can range from subclinical infection to very severe systemic disease. Leishmaniosis is categorized as a neglected tropical disease and the complex immune responses associated withLeishmaniaspecies makes therapeutic treatments and vaccine development challenging for both dogs and humans. In this review, we summarize innate and adaptive immune responses associated withL. infantuminfection in dogs, and we discuss the problems associated with the disease as well as potential solutions and the future direction of required research to help control the parasite.

scholarly journals Detection of Surra (trypanosomiasis) positivity in humans in an outbreak area of Indonesia

2019 ◽  
Vol 28 (2) ◽  
pp. 196-202
Author(s):  
Dyah Haryuningtyas Sawitri ◽  
April Hari Wardhana ◽  
Mohamad Sadikin ◽  
Heri Wibowo
Keyword(s):  
Clinical Signs ◽  
Clinical Manifestations ◽  
Protozoan Parasite ◽  
Trypanosoma Evansi ◽  
Enzyme Linked Immunosorbent Assay ◽  
Serum Samples ◽  
The Public ◽  
Outbreak Area ◽  
Blood Sucking ◽  
Serological Status

BACKGROUND Surra is an infection caused by a blood protozoan parasite, Trypanosoma evansi, and transmitted by blood-sucking insects. The parasite generally infects only animals; however, it was reported to infect an Indian cattle farmer in 2004, followed by reports of other human cases. The most severe Surra outbreak in Indonesia occurred in Sumba Island during 2010–2012, resulting in the death of more than 2,000 livestock. This study was conducted to explore the serological status of farmers who have intensive contact with their livestock against T. evansi infection in Southwest Sumba district. METHODS A total of 24 serum samples were collected from farmers living in the Surra outbreak area. All sera were tested using both card agglutination test for trypanosomiasis/T. evansi (CATT/T. evansi) and field enzyme-linked immunosorbent assay (FELISA). RESULTS Of the 24 serum samples, 4 (16.7%) samples were seropositive for the antigen T. evansi using both tests. This is the first report of human trypanosomiasis (Surra) in Indonesia. Unfortunately, the clinical manifestations of farmers with positive Surra infection were not reported because all sera samples used in this study were obtained from the Public Health Service with no reports of clinical signs from the respondents. CONCLUSIONS Farmers living in the Surra outbreak area have a high risk of being infected with T. evansi due to their potential frequent contact with Surra vectors. Therefore, T. evansi infection in humans requires attention as it might have the potential to develop as a new emerging zoonotic disease in Indonesia.

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