scholarly journals Microbiome disturbance and resilience dynamics of the upper respiratory tract in response to influenza A virus infection in humans and ferrets

2018 ◽  
Author(s):  
Drishti Kaul ◽  
Raveen Rathnasinghe ◽  
Marcela Ferres ◽  
Gene S. Tan ◽  
Aldo Barrera ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Cellular Damage ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Influenza A Virus Infection ◽  
Over Time

AbstractInfection with influenza can be aggravated by bacterial co-infections, which often results in disease exacerbation because of host responses and cellular damage. The native upper respiratory tract (URT) microbiome likely plays a role, yet the effects of influenza infection on the URT microbiome are largely unknown. We performed a longitudinal study to assess the temporal dynamics of the URT microbiomes of uninfected and influenza virus-infected humans and ferrets. Uninfected human patients and ferret URT microbiomes had stable “heathy ecostate” communities both within and between individuals. In contrast, infected patients and ferrets exhibited large changes in bacterial community composition over time and between individuals. The “unhealthy” ecostates of infected individuals progressed towards the “healthy ecostate” over time, coinciding with viral clearance and recovery. Blooms of Pseudomonas were a statistically associated constant in the disturbed microbiomes of infected individuals. The dynamic and resilient nature of the microbiome during influenza virus infection in multiple hosts provides a compelling rationale for the maintenance of the microbiome homeostasis as a potential therapeutic target to prevent IAV associated bacterial co-infections.One Sentence SummaryDynamics of the upper respiratory tract microbiome during influenza A virus infection

scholarly journals Microbiome disturbance and resilience dynamics of the upper respiratory tract during influenza A virus infection

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Drishti Kaul ◽  
Raveen Rathnasinghe ◽  
Marcela Ferres ◽  
Gene S. Tan ◽  
Aldo Barrera ◽  
...  
Keyword(s):  
Virus Infection ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Influenza A Virus Infection

scholarly journals Secretory IgA in Mucosa of Pharynx and Larynx Plays an Important Role against Influenza A Virus Infection in Kidney Yang Deficiency Syndrome Model

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Shaozhe Zhao ◽  
Lei Yuan ◽  
Yi Li ◽  
Longchan Liu ◽  
Zixin Luo ◽  
...  
Keyword(s):  
High Risk ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Influenza A Virus ◽  
Influenza A ◽  
Morbidity And Mortality ◽  
Secretory Iga ◽  
Upper Respiratory Tract ◽  
Gene Expressions ◽  
Upper Respiratory

Objective. Influenza virus poses a major threat to human health and has serious morbidity and mortality which commonly occurs in high-risk populations. Pharynx and larynx of the upper respiratory tract mucosa is the first defense line against influenza virus infection. However, the ability of the pharynx and larynx organ to eliminate the influenza pathogen is still not clear under different host conditions. Methods. In this study, a mouse model of kidney yang deficiency syndrome (KYDS) was used to mimic high-risk peoples. Two different methods of influenza A (H1N1) virus infection by nasal dropping or tracheal intubation were applied to these mice, which were divided into four groups: normal intubation (NI) group, normal nasal dropping (ND) group, model intubation (MI) group, and model nasal dropping (MD) group. The normal control (NC) group was used as a negative control. Body weight, rectal temperature, and survival rate were observed every day. Histopathologic changes, visceral index, gene expressions of H1N1, cytokine expressions, secretory IgA (SIgA) antibodies of tracheal lavage fluids in the upper respiratory tract, and bronchoalveolar lavage fluids were analyzed by ELISA. Results. The MD group had an earlier serious morbidity and mortality than the others. MI and NI groups became severe only in the 6th to 7th day after infection. The index of the lung increased significantly in NI, MI, and MD groups. Conversely, indices of the thymus and spleen increased significantly in NC and ND groups. H&E staining showed severe tissue lesions in MD, MI, and NI groups. H1N1 gene expressions were higher in the MD group compared with the MI group on the 3rd day; however, the MD group decreased significantly on the 7th day. IL-6 levels increased remarkably, and SIgA expressions decreased significantly in the MD group compared with the NC group. Conclusions. SIgA secretions are influenced directly by different conditions of the host in the pharynx and larynx in the upper respiratory tract mucosa. In the KYDS virus disease mode, SIgA expressions could be inhibited severely, which leads to serious morbidity and mortality after influenza A virus infection. The SIgA expressions of the pharynx and larynx would be an important target in high-risk populations against the influenza A virus for vaccine or antiviral drugs research.

scholarly journals Salivary Blockade Protects the Lower Respiratory Tract of Mice from Lethal Influenza Virus Infection

2017 ◽  
Vol 91 (14) ◽  
Author(s):  
Karen Ivinson ◽  
Georgia Deliyannis ◽  
Leanne McNabb ◽  
Lara Grollo ◽  
Brad Gilbertson ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Respiratory Tract ◽  
Lower Respiratory Tract ◽  
Influenza A ◽  
Lethal Dose ◽  
Laboratory Mouse ◽  
Influenza Virus Infection ◽  
Upper Respiratory Tract ◽  
Upper Respiratory

ABSTRACT It is possible to model the progression of influenza virus from the upper respiratory tract to the lower respiratory tract in the mouse using viral inoculum delivered in a restricted manner to the nose. In this model, infection with the A/Udorn/307/72 (Udorn) strain of virus results ultimately in high viral titers in both the trachea and lungs. In contrast, the A/Puerto Rico/8/34 (PR8) strain causes an infection that is almost entirely limited to the nasal passages. The factors that govern the progression of virus down the respiratory tract are not well understood. Here, we show that, while PR8 virus grows to high titers in the nose, an inhibitor present in the saliva blocks further progression of infection to the trachea and lungs and renders an otherwise lethal dose of virus completely asymptomatic. In vitro, the salivary inhibitor was capable of potent neutralization of PR8 virus and an additional 20 strains of type A virus and two type B strains that were tested. The exceptions were Udorn virus and the closely related H3N2 strains A/Port Chalmers/1/73 and A/Victoria/3/75. Characterization of the salivary inhibitor showed it to be independent of sialic acid and other carbohydrates for its function. This and other biochemical properties, together with its virus strain specificity and in vivo function, indicate that the mouse salivary inhibitor is a previously undescribed innate inhibitory molecule that may have evolved to provide pulmonary protection of the species from fatal influenza virus infection. IMPORTANCE Influenza A virus occasionally jumps from aquatic birds, its natural host, into mammals to cause outbreaks of varying severity, including pandemics in humans. Despite the laboratory mouse being used as a model to study influenza virus pathogenesis, natural outbreaks of influenza have not been reported in the species. Here, we shed light on one mechanism that might allow mice to be protected from influenza in the wild. We show that virus deposited in the mouse upper respiratory tract will not progress to the lower respiratory tract due to the presence of a potent inhibitor of the virus in saliva. Containing inhibitor-sensitive virus to the upper respiratory tract renders an otherwise lethal infection subclinical. This knowledge sheds light on how natural inhibitors may have evolved to improve survival in this species.

scholarly journals Routine blood parameters are helpful for early identification of influenza infection in children

2020 ◽  
Author(s):  
Ronghe Zhu ◽  
Cuie Chen ◽  
Qiu Wang ◽  
Xixi Zhang ◽  
Chaosheng Lu ◽  
...  
Keyword(s):  
Influenza Virus ◽  
Virus Infection ◽  
Influenza A Virus ◽  
Early Identification ◽  
Influenza A ◽  
Influenza Infection ◽  
Influenza Virus Infection ◽  
Cutoff Value ◽  
Routine Blood ◽  
Influenza A Virus Infection

Abstract Purpose Routine blood parameters, such as the lymphocyte (LYM) count, platelet (PLT) count, lymphocyte-to-monocyte ratio (LMR), neutrophil-to-lymphocyte ratio (NLR), LYM*PLT and mean platelet volume-to-platelet ratio (MPV/PLT), are widely used to predict the prognosis of infectious diseases. We aimed to explore the value of these parameters in the early identification of influenza virus infection in children.Methods We conducted a single-center, retrospective, observational study of fever with influenza-like symptoms in pediatric outpatients from different age groups and evaluated the predictive value of various routine blood parameters measured within 48 hours of the onset of fever for influenza virus infection.Results The LYM count, PLT count, LMR and LYM*PLT were lower, and the NLR and MPV/PLT were higher in children with an influenza infection (PCR-confirmed and symptomatic). The LYM count, LMR and LYM*PLT in the influenza infection group were lower in the 1- to 6-year-old subgroup, and the LMR and LYM*PLT in the influenza infection group were lower in the >6-year-old subgroup. In the 1- to 6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.75, the sensitivity was 81.87%, the specificity was 84.31%, and the area under the curve (AUC) was 0.886; the cutoff value of the LMR for predicting influenza B virus infection was 3.71, the sensitivity was 73.58%, the specificity was 84.31%, and the AUC was 0.843. In the >6-year-old subgroup, the cutoff value of the LMR for predicting influenza A virus infection was 3.05, the sensitivity was 89.27%, the specificity was 89.61%, and the AUC was 0.949; the cutoff value of the LMR for predicting influenza B virus infection was 2.88, the sensitivity was 83.19%, the specificity was 92.21%, and the AUC was 0.924.Conclusions Routine blood tests are simple, inexpensive and easy to perform, and they are useful for the early identification of influenza virus infection in children. The LMR had the strongest predictive value for influenza virus infection in children older than 1 year, particularly influenza A virus infection.

Microbiota Regulates the TLR7 Signaling Pathway Against Respiratory Tract Influenza A Virus Infection

2013 ◽  
Vol 67 (4) ◽  
pp. 414-422 ◽  
Author(s):  
Sha Wu ◽  
Zhen-You Jiang ◽  
Yi-Fan Sun ◽  
Bin Yu ◽  
Jia Chen ◽  
...  
Keyword(s):  
Virus Infection ◽  
Respiratory Tract ◽  
Signaling Pathway ◽  
Influenza A Virus ◽  
Influenza A ◽  
Influenza A Virus Infection
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