scholarly journals Immunity Reduces Reservoir Host Competence of Peromyscus leucopus forEhrlichia phagocytophila

2000 ◽  
Vol 68 (3) ◽  
pp. 1514-1518 ◽  
Author(s):  
Michael L. Levin ◽  
Durland Fish

ABSTRACT Infection with Ehrlichia phagocytophila in white-footed mice is transient and followed by a strong immune response. We investigated whether the presence of acquired immunity against E. phagocytophila precludes white-footed mice from further maintenance of this agent in nature. Mice were infected withE. phagocytophila via tick bite and challenged either 12 or 16 weeks later by Ixodes scapularis nymphs infected with the same agent. Xenodiagnostic larvae fed upon each mouse simultaneously with challenging nymphs and 1 week thereafter. Ticks were tested for the agent by PCR, and the prevalence of infection was compared to that in ticks that fed upon nonimmune control mice. Only 30% of immunized mice sustained cofeeding transmission of E. phagocytophila between simultaneously feeding infected and uninfected ticks, compared to 100% of control mice. An average of 6.3% of xenodiagnostic ticks acquired Ehrlichia from previously immunized mice when fed 1 week after the challenge, compared to 82.5% infection in the control group. Although an immune response to a single infection with E. phagocytophila in white-footed mice provided only partial protection against reinfection with the same agent, the majority of mice were rendered reservoir incompetent for at least 12 to 16 weeks. Immunity acquired by mice during I. scapularis nymphal activity in early summer may exclude a large proportion of the mouse population from maintainingE. phagocytophila during the period of larval activity later in the season.

2021 ◽  
Author(s):  
Rossana Elena Chahla ◽  
Rodrigo Hernan Tomas-Grau ◽  
Silvia Ines Cazorla ◽  
Diego Ploper ◽  
Esteban Vera Pingitore ◽  
...  

We hypothesized that in individuals with previous SARS-CoV-2 infection, the first vaccine dose would work as a booster, eliciting a faster and more intense immune response. We herein describe antibody responses to the first and second doses of Gam-COVID-Vac (SPUTNIK V) vaccine in health personnel of Tucuman, Argentina, with previous COVID-19 and compared it with uninfected personnel. Individuals with anti-SARS-CoV-2 titers at baseline showed significantly higher responses to the first dose than people with no prior history of disease (p <0.0001), with titers higher to those registered after the second dose in the control group, representing a clear secondary antibody response. This suggests that a single dose of SPUTNIK V for people with previous SARS-CoV-2 infection could contribute to a better use of available doses.


2013 ◽  
Vol 20 (9) ◽  
pp. 1352-1359 ◽  
Author(s):  
Elshaima Mohamed Fawzi ◽  
Teresa Cruz Bustos ◽  
Mercedes Gómez Samblas ◽  
Gloria González-González ◽  
Jenifer Solano ◽  
...  

ABSTRACTSeven 3-month-old, female, helminth-free lambs were immunized intranasally with three doses (1 mg total) of a recombinant part of the catalytic region of the serine/threonine phosphatase 2A (PP2Ar) (group 1 [G1]). In addition, four lambs were used as an adjuvant control group (G2), four as unimmunized, infected controls (G3), and four as unimmunized, uninfected controls (G4). Fifteen days after the last immunization, lambs from G1, G2, and G3 were challenged with 10,000 larval stage 3 (L3) organisms in a plurispecific nematode infection composed of ca. 40%Trichostrongylus colubriformis, 40%Haemonchus contortus, and 20%Teladorsagia circumcincta. All the lambs were clinically monitored throughout the experiment. Parasitological (fecal egg output and immunological response), biopathological (packed-cell volume and leukocyte and eosinophil counts), and zootechnical (live-weight gain) analyses were conducted. On day 105 of the experiment, all the animals were slaughtered and the adult worm population in their abomasa examined. Intranasal administration of PP2Ar with bacterial walls as an adjuvant elicited a strong immune response in the immunized lambs, as evidenced by their humoral immune response. Immunized animals and animals receiving the adjuvant shed significantly (P< 0.001) fewer numbers of parasites' eggs in their feces. The immunization significantly reduced the helminth burden in the abomasa by the end of the experiment (>68%), protection being provided against bothHaemonchusandTeladorsagia. Live-weight gain in the immunized lambs was similar to that in the uninfected controls versus the infected or adjuvanted animal groups. Our results suggest that heterologous immunization of ruminants by intranasal administration may be efficacious in the struggle to control gastrointestinal helminths in these livestock.


Omni-Akuatika ◽  
2017 ◽  
Vol 13 (2) ◽  
Author(s):  
Sukenda Sukenda ◽  
Tuti Sumiati ◽  
Sri Nuryati ◽  
Angela Mariana Lusiastuti ◽  
Dendi Hidayatullah

ABSTRACTFish vaccination aims to induce a specific immune response indicated by an increase of antibodies in vaccinated fish. However, in accordance with time the presence of antibodies will continue to decline. The purpose of this study was to determine the kinetics of specifik immune response and trend mortality against Aeromonas hydrophila and Streptococcus agalactiae on tilapia following vaccination with cocktail vaccine. Fish vaccinated through immersion for 30 minutes in a solution of diluted vaccine. Challenge test was performed for three periods, on day 22, 50, and 78 post-vaccination, fish were challenged with single infection of A. hydrophila 108 cfu. mL-1 and S. agalactiae 104 cfu. mL-1 and co-infection of both bacteria by intraperitoneal. During rearing, the blood fish were taken for determining of serum antibodies, and its  measured by ELISA. The results showed that the concentration of specific antibodies vaccinated fish were significantly higher than the control. The basal antibody levels of A. hydrophila before vaccination were higher than S. agalactiae with OD of 0.104 and 0.069 respectively. The maximum  antibody  response  was  reached  within  70  days  of  the  A. hydrophila OD= 0.264 and 56 days against S. agalactiae OD= 0.188. The mortality rate in the control group was significantly higher than vaccinated on all types and each challenge test period. The trend of mortality due to a single infection of A. hydrophila and co-infections occur more quickly than by S. agalactiae. Lowest mortality occurred in the vaccinated group at 50 day tested challenge.Keywords: kinetics antibody, Aeromnas hydrophila, Streptococcus agalactiae, Oreochromis niloticus


2018 ◽  
Vol 44 (1) ◽  
pp. 6
Author(s):  
Roberto González Garduño ◽  
María Eugenia López Arellano ◽  
Pedro Mendoza de Gives ◽  
Nadia Florencia Ojeda Robertos ◽  
Alfonso Juventino Chay Canul

Background: Trichostrongylus colubriformis is one of the most prevalent gastrointestinal nematodes of sheep in warm climates. In this nematode species, anthelmintic resistance (AR) has been reported, which has motivated the search for alternative methods to control it. One practice is to increase the immune response level through the selection of animals with natural resistance, such as Blackbelly sheep. The aim of this study was to investigate the response of IgA and IgG in serum and saliva and the level of cells involved in the acquired resistance in Blackbelly lambs after single artificial reinfection with a resistant strain of Trichostrongylus colubriformis.Materials, Methods & Results: Sixteen weaned lambs grazed for one month in nematode-contaminated grasslands. All the lambs were treated with Albendazole and Levamisole; later, they were stabled for two months. After that, eight lambs were re-infected with 6000 larvae of T. colubriformis and other eight lambs remained naturally infected. In addition, eight nematode-free lambs raised in cages, served as negative control. Blood samples were taken fortnightly to determine packed cell volume (PCV, %), plasmatic protein (g dL-1), as well as absolute and differential leukocytes. The eggs per gram of feces (EPG) were recorded. An indirect ELISA against T. colubriformis Ag was performed to determine the IgG and IgA levels. All data were analyzed by repeated measures. The EPG in the re-infected group increased after 34 days (625 ± 287), while in the naturally infected group it remained close to 200 ± 158 throughout the study. The control lambs did not show any infection. The PCV (29.4 ± 3.4 %), basophils (44 ± 74), lymphocytes (8443 ± 2845) and monocytes (77 ± 91) counts were not affected by infection. The IgA OD against T. colubriformis increased significantly after 15 days post-infection (dpi) in the re-infected lambs (1.69 ± 0.5, 80% with regards to standard). With IgG was not possible to distinguish the effect of infection.Discussion: Highly persistent infection of T. colubriformis was observed for at least four months in the naturally infected group despite having been treated with anthelmintics. It is a significant problem because this species has a high prevalence in the region of study and shows anthelmintic resistance. For such reason, is important to evaluate the ability of the animal to develop an immune response. In other study, a natural reduction in the fecal egg count (FEC) was indicated at 100 dpi in the same species, but in the present work, the FEC could not be reduced until around 120 days when the naturally infected lambs were evaluated. The larger number of neutrophils and leukocytes in both the naturally infected and re-infected groups implies a sustained response for a long time. While the higher counts of eosinophils only in the re-infected group were produced as an immediate response to infection with T. colubriformis. Similarly, with a single infection of T. colubriformis, in Santa Ines sheep the infected lambs showed significantly higher levels of serum IgA than the control group. In this case, differences in IgA activity were observed between the re-infected lambs and the other groups at fifteen dpi, but the basal levels of IgA in the naturally pre-infected lambs were maintained at least five weeks after infection. In conclusion, an increase in the peripheral immune response in lambs re-infected with T. colubriformis resulted from the increase in IgA levels in serum and saliva, and increase in the number of peripheral eosinophils, total leukocytes and neutrophils. Re-infected lambs had a higher level of IgA than naturally infected lambs and control lambs, making possible to promote the immune response with a single re-infection with Trichostrongylus colubriformis.


2013 ◽  
Vol 68 (7) ◽  
pp. 57-60
Author(s):  
O. A. Sharavii ◽  
S. V. Smirnova

 Aim. The study of the prevalence and clinical peculiarities of Mycoplasmosis and Chlamydiosis in patients with different pathogenic forms of bronchial asthma (BA) taking into account ethnicity of a patient. Subjects and Methods. The research covered 239 subjects – both the Europeoids and the Mongoloids in the city of Krasnoyarsk and the town of Kyzyl, all of them being BA patients of different stages, including acute stage and practically healthy. We had determined antigens Mycoplasma pneumoniae, Mycoplasma hominis, Chlamydophila pneumoniae, Chlamydophila psittaci and Chlamydia trachomatis in smears of mucosa of pharynx and antibodies to these antigens in peripheral blood serum. Results.  We found high frequency of Mycoplasmosis and Chlamydiosis in the inhabitants of Eastern Siberia, BA patients with different pathogenic forms as compared to control group. We had determined ethnic peculiarities of specific immune response: IgM to М. pneumoniae was revealed in the Europoids more frequently than in the Mongoloids, but IgM to С. pneumoniae and to C. trachomatis, C. trachomatis antigens had been revealed more often in the Mongoloids than in the Europoids. We accepted as clinical equivalents of Mycoplasmosis and Chlamydiosis diagnostics the following signs: temperature around 37C (subfebrile temperature), non-intensive but stable coughing with scanty mucous and muco-purulent sputum, dyspnea of mixed character. Conclusions. Mycoplasma and Chlamydia are meaningful etiologic factors of bronchial asthma. We have found the peculiarities of immune response depending on ethnicity of a patient (ethnic belonging). Clinical markers of Mycoplasmosis and Chlamydiosis should be taken into account in bronchial asthma in order to provide diagnostics timely as well as eradication of infection agents. Because of insufficient knowledge of problem of bronchial asthma related to contamination with Мycoplasma and Chlamydia we put the goal to study the frequency of Mycoplasmosis and Chlamydiosis occurrence in bronchial asthma patients and determine the characteristics clinical course of diseases. We defined antigens Мycoplasma pneumoniae, Мycoplasma hominis, Chlamydophila pneumoniaе, Chlamydophila psittaci, Chlamydia trachomatis in smears of oropharynx mucosa and antibodies to them in blood serum. 


2014 ◽  
Vol 3 (1) ◽  
pp. 150-157
Author(s):  
Khalid M. Gaafar

The research was conducted to study the effect of feeding broiler chickens on diets containing isomaltooligosaccharides on the growth performance, carcass traits and immune response. 90-one day old broiler chicks were used according to completely randomized two treatment groups and one control, 30 birds each. Birds fed ad-libitum on basal starter and grower-finisher diets for 35 day. Diets of treatment`s groups contained 0.5 g/Kg and 1 g/Kg of Isomaltooligosaccharides, while the control group fed on the basal diets without Isomaltooligosaccharides supplementation. Dietary supplementation of broiler chickens with Isomaltooligosaccharides improved body weight, feed conversion, carcass traits, two lymphoid organs weight and log antibody titer against avian flu vaccine. Most of the highest values were for birds fed low levels of Isomaltooligosaccharides. Feed intake decreases as Isomaltooligosaccharides level increases. Dietary supplementation with Isomaltooligosaccharides did not affect the lipids profile (triglycerides, total cholesterol, LDL and HDL), however the blood VLDL levels decreased with increased levels of Malondialdehyde and Glutathione reductase. Collectively, Dietary supplementation of broiler chickens with 0.5 g/Kg diet of Isomaltooligosaccharides improved growth performance, carcass traits and immune status.


Vaccines ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 419
Author(s):  
Daehyun Kim ◽  
Joonho Moon ◽  
Jaejung Ha ◽  
Doyoon Kim ◽  
Junkoo Yi

Vaccination against foot-and-mouth disease is the most common method for preventing the spread of the disease; the negative effects include miscarriage, early embryo death, lower milk production, and decreased growth of fattening cattle. Therefore, in this study, we analyze the side effects of vaccination by determining the acute immune response and ovulation rate after vaccinating cows for foot-and-mouth disease. The test axis was synchronized with ovulation using 100 Hanwoo (Bos taurus coreanae) cows from the Gyeongsangbuk-do Livestock Research Institute; only individuals with estrus confirmed by ovarian ultrasound were used for the test. All test axes were artificially inseminated 21 days after the previous estrus date. The control group was administered 0.9% normal saline, the negative control was injected intramuscularly with lipopolysaccharide (LPS; 0.5 µg/kg), and the test group was administered a foot-and-mouth disease virus vaccine (FMDV vaccine; bioaftogen, O and A serotypes, inactivated vaccine) 2, 9, and 16 days before artificial insemination. White blood cells and neutrophils increased significantly 1 day after vaccination, and body temperature in the rumen increased for 16 h after vaccination. Ovulation was detected 1 day after artificial fertilization by ovarian ultrasound. The ovulation rates were as follows: control 89%, LPS 60%, FMDV vaccine (−2 d) 50%, FMDV vaccine (−9 d) 75%, and FMDV vaccine (−16 d) 75%. In particular, the FMDV vaccine (−2 d) test group confirmed that ovulation was delayed for 4 days after artificial insemination. In addition, it was confirmed that it took 9 days after inoculation for the plasma contents of haptoglobin and serum amyloid A to recover to the normal range as the main acute immune response factors. The conception rate of the FMDV vaccine (−2 d) group was 20%, which was significantly lower than that of the other test groups.


Agriculture ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 662
Author(s):  
Sabrin Abdelrahman Morshedy ◽  
Ahmed M. Abdelmodather ◽  
Mohamed M. Basyony ◽  
Soliman A. Zahran ◽  
Mohamed A. Hassan

Vegetable oils are a source of natural antioxidants, including tocopherols, sterols, phenolic compounds, coenzymes, and polyunsaturated fatty acids that provide nutritional value, organoleptic properties, and significantly delay or prevent lipid oxidation. Eighty-four V-line rabbits at 5 weeks of age with an initial body weight (BW) of 535.60 ± 13.48 g were assigned randomly to four experimental groups (seven replicates in each group with three rabbits each). The first group served as a control and received 0.3 mL/kg BW of distilled water (CON), while the second and third groups received 0.3 mL/kg BW of rocket seed oil (RSO) and wheat germ oil (WGO), respectively. The fourth group received a mixture of oils consisting of 0.15 mL of RSO and 0.15 mL of WGO/kg BW (MOs). The experiment lasted 7 weeks. The study investigated the effects of RSO, WGO, and their mixture on growth performance, feed utilization, antioxidant status, and immune response of growing rabbits. The results indicated that the rabbits that were administered orally with RSO and WGO or their mixture had higher (p ≤ 0.05) final BW, weight gain, and average daily gain when compared to the control group. In addition, the feed conversion ratio improved significantly with RSO, WGO, and MOs treatments. Different oil treatments improved nutrient digestibility, nutritive value, and nitrogen balance. Moreover, the rabbits that received RSO, WGO, and their mixture had an improvement the meat fatty acid composition compared to the control rabbits. Oral administration of RSO, WGO, and their mixture significantly improved serum protein fractions, decreased blood urea nitrogen, and had a positive effect on serum total lipids, HDL-c, and LDL-c. Furthermore, the treatments of RSO, WGO, and MOs had a significant improvement in the antioxidative status and immune response.


Vaccines ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 361
Author(s):  
Valentina Valenzuela-Muñoz ◽  
Bárbara P. Benavente ◽  
Antonio Casuso ◽  
Yeny Leal ◽  
Cristian Gallardo-Escárate

Infection processes displayed by pathogens require the acquisition of essential inorganic nutrients and trace elements from the host to survive and proliferate. Without a doubt, iron is a crucial trace metal for all living organisms and also a pivotal component in the host–parasite interactions. In particular, the host reduces the iron available to face the infectious disease, increasing iron transport proteins’ expression and activating the heme synthesis and degradation pathways. Moreover, recent findings have suggested that iron metabolism modulation in fish promotes the immune response by reducing cellular iron toxicity. We hypothesized that recombinant proteins related to iron metabolism could modulate the fish’s immune system through iron metabolism and iron-responsive genes. Here a chimeric iron transport protein (IPath®) was bioinformatically designed and then expressed in a recombinant bacterial system. The IPath® protein showed a significant chelating activity under in vitro conditions and biological activity. Taking this evidence, a vaccine candidate based on IPath® was evaluated in Atlantic salmon challenged with three different fish pathogens. Experimental trials were conducted using two fish groups: one immunized with IPath® and another injected with adjutant as the control group. After 400 accumulated thermal units (ATUs), two different infection trials were performed. In the first one, fish were infected with the bacterium Aeromonas salmonicida, and in a second trial, fish were exposed to the ectoparasite Caligus rogercresseyi and subsequently infected with the intracellular bacterium Piscirickettsia salmonis. Fish immunized with IPath® showed a significant delay in the mortality curve in response to A. salmonicida and P. salmonis infections. However, no significant differences between infected and control fish groups were observed at the end of the experiment. Notably, sea lice burden reduction was observed in vaccinated Atlantic salmon. Transcriptional analysis evidenced a high modulation of iron-homeostasis-related genes in fish vaccinated with IPath® compared to the control group during the infection. Moreover, increasing expression of Atlantic salmon IgT was associated with IPath® immunization. This study provides evidence that the IPath® protein could be used as an antigen or booster in commercial fish vaccines, improving the immune response against relevant pathogens for salmon aquaculture.


Viruses ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1103
Author(s):  
Keyla Santos Guedes de Sá ◽  
Ednelza da Silva Graça Amoras ◽  
Simone Regina Souza da Silva Conde ◽  
Maria Alice Freitas Queiroz ◽  
Izaura Maria Vieira Cayres-Vallinoto ◽  
...  

An inefficient immune response against the hepatitis C virus (HCV), combined with viral evasion mechanisms, is responsible for the chronicity of infection. The need to evaluate the innate mechanisms of the immune response, such as TLR3 and IFN-λ3, and their relationship with the virus–host interaction is important for understanding the pathogenesis of chronic hepatitis C. The present study aimed to investigate the gene expressions of TRL3 and IFNL3 in liver tissue, seeking to evaluate whether these could be potential biomarkers of HCV infection. A total of 23 liver biopsy samples were collected from patients with chronic HCV, and 8 biopsies were collected from healthy control patients. RNA extraction, reverse transcription and qPCR were performed to quantify the relative gene expressions of TLR3 and IFNL3. Data on the viral load; AST, ALT, GGT and AFP levels; and the viral genotype were collected from the patients′ medical records. The intrahepatic expression of TLR3 (p = 0.0326) was higher in chronic HCV carriers than in the control group, and the expression of IFNL3 (p = 0.0037) was lower in chronic HCV carriers than in the healthy control group. The expression levels of TLR3 (p = 0.0030) and IFNL3 (p = 0.0036) were higher in the early stages of fibrosis and of necroinflammatory activity in the liver; in contrast, TLR3 and IFNL3 expressions were lower in the more advanced stages of fibrosis and inflammation. There was no correlation between the gene expression and the serum viral load. Regarding the initial METAVIR scale scores, liver transaminase levels were lower in patients with advanced fibrosis when correlated with TLR3 and IFNL3 gene expressions. The results suggest that in the early stages of the development of hepatic fibrosis, TLR3 and IFN-λ3 play important roles in the antiviral response and in the modulation of the tolerogenic liver environment because there is a decrease in the intrahepatic expressions of TLR3 and IFNL3 in the advanced stages of fibrosis, probably due to viral evasion mechanisms.


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