scholarly journals Experimental Staphylococcus aureus Mastitis Infection Model by Teat Dipping in Bacterial Culture Suspension in Dairy Cows

Animals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 751
Author(s):  
Oudessa Kerro Dego ◽  
Paulina A. Pacha ◽  
Barbara E. Gillespie ◽  
Gina M. Pighetti
Keyword(s):  
Staphylococcus Aureus ◽  
Dairy Cows ◽  
Natural Infection ◽  
Effective Vaccine ◽  
Bacterial Suspension ◽  
Infection Model ◽  
Culture Suspension ◽  
Physical Barriers ◽  
And Control ◽  
Teat Dipping

Mastitis is inflammation of mammary glands usually caused by bacteria such as Staphylococcus aureus. Dairy cows are susceptible to mastitis during early dry and transition periods. Effective vaccine is needed during these periods. One of the limitations to develop an effective vaccine against S. aureus is the absence of good infection model. Intramammary infusion (IMIF) with S. aureus has been used as an infection model to test vaccine efficacy. IMIF is reliable in causing mastitis, but it bypasses physical barriers, non-specific natural defenses, and immunity in the teat canal. IMIF also transfers a large number of bacteria into the intramammary area at once. The objective of this study was to develop S. aureus IMIF model that mimics natural infection. Eight Holstein dairy cows were randomly divided into two groups of experimental (n = 5) and control (n = 3) cows. All teats of experimental cows were dipped in S. aureus culture suspension, whereas that of control cows were dipped in phosphate-buffered saline. Results showed that four of five cows were infected with challenge strain by day 3 of the challenge. The remaining cow was infected with Staphylococcus chromogenes. In conclusion, an experimental S. aureus intramammary infection can be induced by teat dipping into bacterial suspension.

scholarly journals Viremia in Equine Herpes Virus-1 infection and a possible link to Transient Protective Immunity

2021 ◽  
Vol 9 (1) ◽  
pp. 11-16
Author(s):  
AR Awan ◽  
OL Tulp ◽  
HJ Field
Keyword(s):  
Immune Response ◽  
Immune Responses ◽  
Murine Model ◽  
Herpes Virus ◽  
Natural Infection ◽  
Fluorescent Antibody ◽  
Buffy Coat ◽  
Effective Vaccine ◽  
Infection Model ◽  
Herpès Virus

Equine herpes virus (EHV-1) causes respiratory infections in equine, and results in abortion, paresis, neonatal death, and retinopathy and the virus may become latent following initial infection. Virus entry is via the respiratory route, and the virus replicates in the host in ciliated and non-ciliated epithelial cells of the respiratory tract and in Type 1 and Type 2 pneumocytes in the lung parenchyma. After viral replication in the respiratory system, the virus can become disseminated to other parts of body via viraemic cells. The virus also can cross the placenta which leads to abortion of live or dead fetuses without premonitory signs. Infected horses show transient immunity after natural or experimental infection and immune responses to EHV-1, but the immunoprotective status begins to decline after a few months of active infection. Due to the transient immune response, recovered horses are not immunoprotected and thus are prone to subsequent re-infection. Immunity is not long lived after experimental or natural infection, and as a result the development of an effective vaccine has remained a challenge. In this study viraemic cells were studied in a murine EHV-1 infection model. Mice were infected intranasally and viraemic cells were studied on days three and five which occurs during the peak of the infection. The results of this study may help to identify the nature of viraemic cells and their role in the transient immune response to infection. Buffy coat cells and lungs were removed and stained with a fluorescent antibody test for EHV-1 antigen, and lung specimens were subjected to transmission electron microscopy. Both techniques confirmed the presence of viraemic cells in lung tissues. These viraemic cells were further stained for EHV-1 antigen, and for CD4 or CD8 biomarkers and results are discussed re: pathogenesis of EHV-1 infection, identification of viraemic cells in a murine model and possible link of viraemia to transient immune responses in EHV-1 infection, which demonstrate the validity of this murine model for the investigation of the cytopathologic mechanism and sequelae of EHV manifestation in this model.

scholarly journals Effects of DQ-113, a New Quinolone, against Methicillin- and Vancomycin-Resistant Staphylococcus aureus-Caused Hematogenous Pulmonary Infections in Mice

2003 ◽  
Vol 47 (12) ◽  
pp. 3694-3698 ◽  
Author(s):  
Yukihiro Kaneko ◽  
Katsunori Yanagihara ◽  
Yoshitsugu Miyazaki ◽  
Kazuhiro Tsukamoto ◽  
Yoichi Hirakata ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Histopathological Examination ◽  
Untreated Group ◽  
The Other ◽  
Infection Model ◽  
Pulmonary Infections ◽  
Viable Bacteria ◽  
Mrsa Infection ◽  
And Control ◽  
Inflammatory Changes

ABSTRACT We compared the effects of DQ-113, a new quinolone, to those of vancomycin (VCM) and teicoplanin (TEIC) in murine models of hematogenous pulmonary infections caused by methicillin-resistant Staphylococcus aureus (MRSA) and VCM-insensitive S. aureus (VISA). The MICs of DQ-113, VCM, and TEIC for MRSA were 0.125, 1.0, and 0.5μ g/ml, respectively; and those for VISA were 0.25, 8.0, and 8.0μ g/ml, respectively. Treatment with DQ-113 resulted in a significant decrease in the number of viable bacteria in the lungs of the mice used in the MRSA infection model (counts in mice treated with DQ-113, VCM, and TEIC and control mice, 6.33 ± 0.22, 7.99± 0.14, 7.36 ± 0.20, and 8.47 ± 0.22 log10 CFU/lung [mean ± standard error of the mean], respectively [P < 0.01 for the group treated with DQ-113 compared with the group treated with VCM or TEIC or the untreated group]). Mice infected with VISA were pretreated with cyclophosphamide, and the survival rate was recorded daily for 10 days. At the end of this period, 90% of the DQ-113-treated mice were still alive, whereas only 45 to 55% of the mice in the other three groups were still alive (P < 0.05 for the group treated with DQ-113 compared with the group treated with VCM or TEIC or the untreated group]). DQ-113 also significantly (P < 0.05) reduced the number of viable bacteria in the lungs compared with those in the lungs of the other three groups (counts in mice treated with DQ-113, VCM, and TEIC and control mice, 5.76 ± 0.39, 7.33 ± 0.07, 6.90± 0.21, and 7.44 ± 0.17 log10 CFU/lung, respectively). Histopathological examination revealed milder inflammatory changes in DQ-113-treated mice than in the mice in the other groups. Of the antibiotics analyzed, the parameters of area under the concentration-time from 0 to 6 h (AUC0-6)/MIC and the time that the AUC0-6 exceeded the MIC were the highest for DQ-113. Our results suggest that DQ-113 is potent and effective for the treatment of hematogenous pulmonary infections caused by MRSA and VISA strains.

scholarly journals Four-Component Staphylococcus aureus Vaccine 4C-Staph Enhances Fcγ Receptor Expression in Neutrophils and Monocytes and Mitigates S. aureus Infection in Neutropenic Mice

2015 ◽  
Vol 83 (8) ◽  
pp. 3157-3163 ◽  
Author(s):  
Antonina Torre ◽  
Marta Bacconi ◽  
Chiara Sammicheli ◽  
Bruno Galletti ◽  
Donatello Laera ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Bacterial Pathogen ◽  
Receptor Expression ◽  
Effective Vaccine ◽  
Infection Model ◽  
Fcγ Receptor ◽  
Air Pouch ◽  
Content Type ◽  
Specific Antibodies ◽  
Immune Correlates

Staphylococcus aureusis a human bacterial pathogen causing a variety of diseases. The occurrence of multidrug-resistant strains ofStaphylococcus aureusunderlines the need for a vaccine. Defining immune correlates of protection may support the design of an effective vaccine. We used a murineStaphylococcus aureusinfection model, in which bacteria were inoculated in an air pouch generated on the back of the animal. Analysis of the air-pouch content in mice immunized or not with an adjuvanted multiantigen vaccine formulation, four-componentS. aureusvaccine (4C-Staph), prior to infection allowed us to measure bacteria, cytokines, and 4C-Staph-specific antibodies and to analyze host immune cells recruited to the infection site. Immunization with 4C-Staph resulted in accumulation of antigen-specific antibodies in the pouch and mitigated the infection. Neutrophils were the most abundant cells in the pouch, and they showed the upregulation of Fcγ receptor (FcγR) following immunization with 4C-Staph. Reduction of the infection was also obtained in mice immunized with 4C-Staph and depleted of neutrophils; these mice showed an increase in monocytes and macrophages. Upregulation of the FcγR and the presence of antigen-specific antibodies induced by immunization with 4C-Staph may contribute to increase bacterial opsonophagocytosis. Protection in neutropenic mice indicated that an effective vaccine could activate alternative protection mechanisms compensating for neutropenia, a condition often occurring inS. aureus-infected patients.

scholarly journals Ethical and scientific considerations on the establishment of a controlled human infection model for schistosomiasis in Uganda: report of a stakeholders’ meeting held in Entebbe, Uganda.

2018 ◽  
Vol 1 ◽  
pp. 2 ◽  
Author(s):  
Alison M. Elliott ◽  
Meta Roestenberg ◽  
Anne Wajja ◽  
Christopher Opio ◽  
Francis Angumya ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Natural Infection ◽  
Human Infection ◽  
Sub Saharan Africa ◽  
Effective Vaccine ◽  
Infection Model ◽  
Pilot Studies ◽  
Implementation Challenges ◽  
Study Protocols ◽  
Sub Saharan

Controlled human infection (CHI) models are gaining recognition as an approach to accelerating vaccine development, for use in both non-endemic and endemic populations: they can facilitate identification of the most promising candidate vaccines for further trials and advance understanding of protective immunity. Helminths present a continuing health burden in sub-Saharan Africa. Vaccine development for these complex organisms is particularly challenging, partly because protective responses are akin to mechanisms of allergy. A CHI model for Schistosoma mansoni (CHI-S) has been developed at Leiden University Medical Centre, the Netherlands. However, responses to schistosome infections, and candidate vaccines, are likely to be different among people from endemic settings compared to schistosome-naïve Dutch volunteers. Furthermore, among volunteers from endemic regions who have acquired immune responses through prior exposure, schistosome challenge can be used to define responses associated with clinical protection, and thus to guide vaccine development.  To explore the possibility of establishing the CHI-S in Uganda, a Stakeholders’ Meeting was held in Entebbe in 2017. Regulators, community members, researchers and policy-makers discussed implementation challenges and recommended preparatory steps: risk assessment; development of infrastructure and technical capacity to produce the infectious challenge material in Uganda; community engagement from Parliamentary to grass-roots level; pilot studies to establish approaches to assuring fully informed consent and true voluntariness, and strategies for selection of volunteers who can avoid natural infection during the 12-week CHI-S; the building of regulatory capacity; and the development of study protocols and a product dossier in close consultation with ethical and regulatory partners. It was recommended that, on completion, the protocol and product dossier be reviewed for approval in a joint meeting combining ethical, regulatory and environment management authorities. Most importantly, representatives of schistosomiasis-affected communities emphasised the urgent need for an effective vaccine and urged the research community not to delay in the development process.

scholarly journals Ethical and scientific considerations on the establishment of a controlled human infection model for schistosomiasis in Uganda: report of a stakeholders’ meeting held in Entebbe, Uganda.

2018 ◽  
Vol 1 ◽  
pp. 2 ◽  
Author(s):  
Alison M. Elliott ◽  
Meta Roestenberg ◽  
Anne Wajja ◽  
Christopher Opio ◽  
Francis Angumya ◽  
...  
Keyword(s):  
Vaccine Development ◽  
Natural Infection ◽  
Human Infection ◽  
Sub Saharan Africa ◽  
Effective Vaccine ◽  
Infection Model ◽  
Pilot Studies ◽  
Implementation Challenges ◽  
Study Protocols ◽  
Sub Saharan

Controlled human infection (CHI) models are gaining recognition as an approach to accelerating vaccine development, for use in both non-endemic and endemic populations: they can facilitate identification of the most promising candidate vaccines for further trials and advance understanding of protective immunity. Helminths present a continuing health burden in sub-Saharan Africa. Vaccine development for these complex organisms is particularly challenging, partly because protective responses are akin to mechanisms of allergy. A CHI model for Schistosoma mansoni (CHI-S) has been developed at Leiden University Medical Centre, the Netherlands. However, responses to schistosome infections, and candidate vaccines, are likely to be different among people from endemic settings compared to schistosome-naïve Dutch volunteers. Furthermore, among volunteers from endemic regions who have acquired immune responses through prior exposure, schistosome challenge can be used to define responses associated with clinical protection, and thus to guide vaccine development.  To explore the possibility of establishing the CHI-S in Uganda, a Stakeholders’ Meeting was held in Entebbe in 2017. Regulators, community members, researchers and policy-makers discussed implementation challenges and recommended preparatory steps: risk assessment; development of infrastructure and technical capacity to produce the infectious challenge material in Uganda; community engagement from Parliamentary to grass-roots level; pilot studies to establish approaches to assuring fully informed consent and true voluntariness, and strategies for selection of volunteers who can avoid natural infection during the 12-week CHI-S; the building of regulatory capacity; and the development of study protocols and a product dossier in close consultation with ethical and regulatory partners. It was recommended that, on completion, the protocol and product dossier be reviewed for approval in a joint meeting combining ethical, regulatory and environment management authorities. Most importantly, representatives of schistosomiasis-affected communities emphasised the urgent need for an effective vaccine and urged the research community not to delay in the development process.

scholarly journals Broad and Effective Protection against Staphylococcus aureus Is Elicited by a Multivalent Vaccine Formulated with Novel Antigens

mSphere ◽  
2019 ◽  
Vol 4 (5) ◽  
Author(s):  
Jian Deng ◽  
Xiaolei Wang ◽  
Bao-Zhong Zhang ◽  
Peng Gao ◽  
Qiubin Lin ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
T Cells ◽  
Γδ T Cells ◽  
Infection Process ◽  
Effective Vaccine ◽  
Infection Model ◽  
Content Type ◽  
Multivalent Vaccine ◽  
Protein Components ◽  
Combined Vaccine

ABSTRACT The demand for a prophylactic vaccine against methicillin-resistant Staphylococcus aureus (MRSA) has motivated numerous dedicated research groups to design and develop such a vaccine. In this study, we have developed a multivalent vaccine, Sta-V5, composed of five conserved antigens involved in three important virulence mechanisms. This prototype vaccine conferred up to 100% protection against multiple epidemiologically relevant S. aureus isolates in five different murine disease models. The vaccine not only elicits functional antibodies that mediate opsonophagocytic killing of S. aureus but also mounts robust antigen-specific T-cell responses. In addition, our data implied that γδ T cells contribute to the protection induced by Sta-V5 in a murine skin infection model. IMPORTANCE Staphylococcus aureus infections, especially MRSA infections, are becoming a major global health issue and are resulting in mortality rates that are increasing every year. However, an effective vaccine is lacking due to the complexity of the infection process of S. aureus. In this study, we found that the addition of two novel protein components to three well-studied vaccine candidates significantly improved the efficacy of the combined vaccine. Furthermore, the five-component vaccine not only elicits a robust antibody response but also induces cytokine secretion by T cells, making it a promising vaccine candidate to fill the void.

scholarly journals Natural Infection of Dairy Cows with Bovine Leukemia Virus Affects Immunoglobulin Levels in Saliva and Serum but Not Milk

Pathogens ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 907
Author(s):  
Monika Dziuba ◽  
Vickie J. Ruggiero ◽  
Catherine Wilson ◽  
Paul C. Bartlett ◽  
Paul M. Coussens
Keyword(s):  
Pilot Study ◽  
Dairy Cows ◽  
Bovine Leukemia Virus ◽  
Leukemia Virus ◽  
Natural Infection ◽  
Total Serum ◽  
Serum Samples ◽  
Retroviral Infection ◽  
Serum Iga ◽  
The Impact

Bovine leukemia virus (BLV) is a retroviral infection that disrupts the immune function of infected animals. It is widespread among U.S. dairy cattle. In this pilot study, the average total IgA and IgM concentrations in milk, saliva, and serum samples from BLV ELISA-positive (ELISA+) dairy cows were compared against samples from BLV ELISA-negative (ELISA−) cows using the Kruskal–Wallis test (with ties). The results from ELISA+ cows were also stratified by lymphocyte count (LC) and proviral load (PVL). In milk and saliva from ELISA+ cows, the average total IgA and IgM concentrations were decreased compared to ELISA− cows, although this was only statistically significant for saliva IgM in cows with low PVL (p = 0.0424). Numerically, the average total IgA concentrations were 33.6% lower in milk and 23.7% lower in saliva, and the average total IgM concentrations were 42.4% lower in milk and 15.5% lower in saliva. No significant differences were observed in the total serum IgA concentrations, regardless of PVL and LC. The total serum IgM from ELISA+ cows was significantly decreased (p = 0.0223), with the largest decreases occurring in the highest PVL and LC subgroups. This pilot study is a first step in investigating the impact of BLV on mucosal immunity and will require further exploration in each of the various stages of disease progression.

Properties and control of cold-induced small colony variants of Staphylococcus aureus

2020 ◽  
pp. 100874
Author(s):  
Jiaju Qiao ◽  
Mengjiao Zhu ◽  
Yun Fan ◽  
Zhaoxin Lu ◽  
Fengxia Lv ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Small Colony Variants ◽  
Small Colony ◽  
And Control

scholarly journals Effects of Intrauterine Infusion of a Chitosan Solution on Recovery and Subsequent Reproductive Performance of Early Postpartum Dairy Cows with Endometritis: A Pilot Field Trial

Animals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 197
Author(s):  
Hiroaki Okawa ◽  
Missaka M.P. Wijayagunawardane ◽  
Peter L.A.M. Vos ◽  
Osamu Yamato ◽  
Masayasu Taniguchi ◽  
...  
Keyword(s):  
Dairy Cows ◽  
Reproductive Performance ◽  
Polymorphonuclear Leukocytes ◽  
Prostaglandin F2α ◽  
Chitosan Solution ◽  
Control Group ◽  
Control Groups ◽  
Early Postpartum Period ◽  
Early Postpartum ◽  
And Control

This study investigated the efficacy of intrauterine infusion of a chitosan solution (CHT) on uterine recovery in early postpartum dairy cows with or without endometritis, and their subsequent reproductive performance. In Experiment 1, cows with endometritis at 3 weeks postpartum were administered CHT (n = 5) and prostaglandin F2α (PGF2α) (n = 4). Untreated cows (n = 7) served as the control group. In Experiment 2, 18 cows with a normally recovered uterus at the fresh cow check (mean, 35 days postpartum) were assigned to the CHT (n = 10) and control (n = 8) groups, and intrauterine infusion was conducted in the CHT group. Overall, in Experiment 1, the percentage of polymorphonuclear leukocytes significantly declined in the CHT group (32.3 ± 10.2 to 5.5 ± 2.4, p < 0.05) from week 3 to week 5, but no decline occurred in the PGF2α and control groups. In Experiment 2, the CHT and control groups showed no significant differences in reproductive parameters, suggesting the absence of adverse effects of CHT on fertility. These results suggest that intrauterine infusion of CHT in the early postpartum period effectively accelerates uterine recovery from endometritis and might be a suitable replacement for PGF2α administration.

Sign in / Sign up

Export Citation Format

Share Document