scholarly journals Kinetics of BoHV-1 Dissemination in an in Vitro Culture of Bovine Upper Respiratory Tract Mucosa Explants

ILAR Journal ◽  
2012 ◽  
Vol 53 (1) ◽  
pp. E43-E54 ◽  
Author(s):  
L. Steukers ◽  
A. P. Vandekerckhove ◽  
W. Van den Broeck ◽  
S. Glorieux ◽  
H. J. Nauwynck
Keyword(s):  
Respiratory Tract ◽  
In Vitro Culture ◽  
Upper Respiratory Tract ◽  
Upper Respiratory ◽  
Kinetics Of

scholarly journals Asymptomatic COVID-19 Adult Outpatients identified as Significant Viable SARS-CoV-2 Shedders 

2021 ◽  
Author(s):  
Marie Glenet ◽  
Anne-Laure Lebreil ◽  
Laetitia Heng ◽  
Yohan N’Guyen ◽  
Ittah Meyer ◽  
...  
Keyword(s):  
Respiratory Tract ◽  
Control Measures ◽  
Upper Respiratory Tract ◽  
Rna Detection ◽  
Viral Loads ◽  
Infection Control Measures ◽  
Infected Adult ◽  
Asymptomatic Adult ◽  
Upper Respiratory ◽  
Kinetics Of

Abstract Differential kinetics of RNA loads and infectious viral levels in the upper respiratory tract between asymptomatic and symptomatic SARS-CoV-2 infected adult outpatients remain unclear limiting recommendations that may guide clinical management, infection control measures and occupational health decisions. In the present investigation, 496 (2.5%) of 17,911 French adult outpatients were positive for an upper respiratory tract SARS-CoV-2 RNA detection by a quantitative RT-PCR assay, of which 180 (36.3%) were COVID-19 asymptomatic. Of these adult asymptomatic viral shedders, 84.4% had mean to high RNA viral loads (Ct values<30) which median value was significantly higher than that observed in symptomatic subjects (P=0.029), and 50.6% were positive by cell culture assays of their upper respiratory tract specimens. Our findings indicate that COVID-19 asymptomatic adult outpatients are significant viable SARS-CoV-2 shedders in their upper respiratory tract playing a major potential role as SARS-CoV-2 transmitters in various epidemiological transmission chains, promoting COVID-19 resurgence in populations.

scholarly journals Case Report: Infection With SARS-CoV-2 in the Presence of High Levels of Vaccine-Induced Neutralizing Antibody Responses

2021 ◽  
Vol 8 ◽  
Author(s):  
Bianca Schulte ◽  
Benjamin Marx ◽  
Marek Korencak ◽  
Dorian Emmert ◽  
Souhaib Aldabbagh ◽  
...  
Keyword(s):  
Case Report ◽  
Respiratory Tract ◽  
Neutralizing Antibody ◽  
Antibody Responses ◽  
Upper Respiratory Tract ◽  
Protective Measures ◽  
Specific Antibodies ◽  
Household Members ◽  
Upper Respiratory

We present a case of SARS-CoV-2 B.1. 525 infection in a healthcare worker despite the presence of highly neutralizing, multivariant-specific antibodies 7 weeks after full vaccination with the mRNA vaccine BNT162b2. We show that the virus replicated to high levels in the upper respiratory tract over the course of several days in the presence of strong antibody responses. The virus was readily propagatable in vitro, demonstrating the potential to transmit to others, bolstered by the fact that several household members were equally infected. This highlights the importance of protective measures even in vaccinated individuals.

scholarly journals Effects of Ammonia Inhalation and Acetic Acid Pretreatment on Colonization Kinetics of Toxigenic Pasteurella multocida within Upper Respiratory Tracts of Swine

1998 ◽  
Vol 36 (5) ◽  
pp. 1260-1265 ◽  
Author(s):  
T. D. C. Hamilton ◽  
J. M. Roe ◽  
C. M. Hayes ◽  
A. J. F. Webster
Keyword(s):  
Acetic Acid ◽  
Respiratory Tract ◽  
Nasal Cavity ◽  
Pasteurella Multocida ◽  
Atrophic Rhinitis ◽  
Upper Respiratory Tract ◽  
Acid Pretreatment ◽  
Morphometric Index ◽  
Upper Respiratory ◽  
Kinetics Of

Pigs reared in intensive production systems are continuously exposed to ammonia released by the microbial degradation of their excrement. Exposure to this gas has been shown to increase the severity of the disease progressive atrophic rhinitis by facilitating colonization of the pig’s upper respiratory tract by Pasteurella multocida. The etiological mechanism responsible for this synergy was investigated by studying the colonization kinetics of P. multocida enhanced by ammonia and comparing them with those evoked by an established disease model. Three-week-old Large White piglets were weaned and allocated to five experimental groups (groups A to E). Pigs in groups A and B were exposed continuously to ammonia at 20 ppm for the first 2 weeks of the study. Pigs in group C were pretreated with 0.5 ml of 1% acetic acid per nostril on days −2 and −1 of the study. On day 0 all the pigs in groups A, C, and D were inoculated with 1.4 × 108 toxigenic P. multocida organisms given by the intranasal route. The kinetics of P. multocida colonization were established by testing samples obtained at weekly intervals throughout the study. The study was terminated on day 37, and the extent of turbinate atrophy was determined by using a morphometric index. The results of the study showed that exposure to aerial ammonia for a limited period had a marked effect on the colonization of toxigenic P. multocidain the nasal cavities of pigs, which resulted in the almost total exclusion of commensal flora. In contrast, ammonia had only a limited effect on P. multocida colonization at the tonsil. The exacerbation of P. multocida colonization by ammonia was restricted to the period of ammonia exposure, and the number ofP. multocida organisms colonizing the upper respiratory tract declined rapidly upon the cessation of exposure to ammonia. During the exposure period, the ammonia levels in mucus recovered from the nasal cavity and tonsil were found to be 7- and 3.5-fold higher, respectively, than the levels in samples taken from unexposed controls. Acetic acid pretreatment also induced marked colonization of the nasal cavity which, in contrast to that induced by ammonia, persisted throughout the time course of the study. Furthermore, acetic acid pretreatment induced marked but transient colonization of the tonsil. These findings suggest that the synergistic effect of ammonia acts through an etiological mechanism different from that evoked by acetic acid pretreatment. A strong correlation was found between the numbers of P. multocida organisms isolated from the nasal cavity and the severity of clinical lesions, as determined by using a morphometric index. The data presented in the paper highlight the potential importance of ammonia as an exacerbating factor in respiratory disease of intensively reared livestock.

Antiviral Properties of Food Plants Could Help to Reduce Contagion and Severity in SARS-CoV-2 Infections

2021 ◽  
Vol 07 ◽  
Author(s):  
Betina Cardoso
Keyword(s):  
Respiratory Tract ◽  
Literature Search ◽  
Food Plants ◽  
Upper Respiratory Tract ◽  
Site Specific ◽  
In Vivo Experiments ◽  
Upper Respiratory ◽  
Novel Coronavirus

Introduction: The importance of an immediate tool to help patients and prevent viral diffusion of new pneumonia caused by 2019 novel coronavirus (2019-nCoV or SARS-CoV-2) that causes the disease COVID-19 becomes evident. Recent articles have reported on body site-specific SARS-CoV-2 infection, showing very active replication in the throat and upper respiratory tract when symptoms were still mild, and thus being efficient in viral transmission in sputum. Material and Methods: An alternative that may be feasible is to resort to scientific studies that demonstrate the antiviral potential of medicinal plants species through in-vitro and in-vivo experiments to alleviate symptoms and prevent the spread of contagion. A literature search in Scopus and PubMed on herbs and foods with antiviral properties was performed. Results: Herbs and foods with demonstrated antiviral potential have been identified, which could limit SARS-CoV-2 spreading by interfering on ACE2 protein on infection sites. The analysis of transdisciplinary knowledge allows us to connect previous research on the action of common plants and foods on viruses to limit the replication of SARS-CoV-2 in the throat and upper respiratory tract. Conclusions: Herbs and foods with demonstrated antiviral potential have been identified, which could limit SARS-CoV-2 spreading by interfering on ACE2 protein on infection sites. The analysis of transdisciplinary knowledge allows us to connect previous research on the action of common plants and foods on viruses to limit the replication of SARS-CoV-2 in the throat and upper respiratory tract.

Antibiotic Resistance: Relationship to Persistence of Group A Streptococci in the Upper Respiratory Tract

PEDIATRICS ◽  
1996 ◽  
Vol 97 (6) ◽  
pp. 971-975
Author(s):  
Michael A. Gerber
Keyword(s):  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Beta Lactam ◽  
Erythromycin Resistance ◽  
In Vitro Susceptibility ◽  
Beta Lactam Antibiotics ◽  
Group A ◽  
Resistant Strains ◽  
Upper Respiratory

Despite the use of penicillin for more than 40 years in treating GABHS infections, there has been no significant change in the in vitro susceptibility of GABHS to penicillin. Reported failures to eradicate GABHS from the upper respiratory tracts of patients with pharyngitis and the apparent resurgence of serious Group A streptococcal infections and their sequelae probably are not related to the emergence of penicillin resistance. Although erythromycin resistance in GABHS had been a major problem in Japan and continues to be a major problem in Finland, it has not been a problem in this country. The susceptibility of GABHS to the newer macrolide antibiotics appears to be similar to that of erythromycin. Comprehensive, community-wide programs to continuously monitor for erythromycin resistance in GABHS would be difficult to justify. However, because little is known about how erythromycin resistance in GABHS is acquired or spread, it would be reasonable to periodically monitor isolates of GABHS for erythromycin resistance. A substantial proportion of GABHS are currently resistant to tetracyclines and these agents are inappropriate for treating GABHS infections. Although little recent information is available about the susceptibility of GABHS to sulfonamides, these agents have been shown to be ineffective in eradicating GABHS from the upper respiratory tract regardless of the in vitro sensitivities. GABHS have not been shown to be resistant to any of the commonly used oral cephalosporins; however, there is a great deal of variability among these agents in their activity against GABHS. Clindamycin resistance in GABHS has remained unusual. This agent is an alternative for treating GABHS infections due to macrolide-resistant strains in patients who cannot be treated with beta-lactam antibiotics. There is no reason, based on the in vitro susceptibilities of GABHS, to change the current recommendations for treating GABHS infections with penicillin and for using erythromycin for patients who are allergic to penicillin.

A rat nasal epithelial model for predicting upper respiratory tract toxicity: in vivo–in vitro correlations

Toxicology ◽  
2000 ◽  
Vol 145 (1) ◽  
pp. 39-49 ◽  
Author(s):  
J.D Kilgour ◽  
S.A Simpson ◽  
D.J Alexander ◽  
C.J Reed
Keyword(s):  
Respiratory Tract ◽  
Upper Respiratory Tract ◽  
Upper Respiratory

scholarly journals Demonstration of N , N -Dimethyldithiocarbamate as a Copper-Dependent Antibiotic against Multiple Upper Respiratory Tract Pathogens

2021 ◽  
Author(s):  
Sanjay V. Menghani ◽  
Angela Rivera ◽  
Miranda Neubert ◽  
James R. Hagerty ◽  
Lourdes Lewis ◽  
...  
Keyword(s):  
Antibiotic Resistance ◽  
Streptococcus Pneumoniae ◽  
Respiratory Tract ◽  
Dependent Manner ◽  
Upper Respiratory Tract ◽  
Coccidioides Posadasii ◽  
Content Type ◽  
Upper Respiratory

With the rise of antibiotic resistance, approaches that add new antimicrobials to the current repertoire are vital. Here, we investigate putative and known copper ionophores in an attempt to intoxicate bacteria and use ionophore/copper synergy, and we ultimately find success with N , N -dimethyldithiocarbamate (DMDC). We show that DMDC has in vitro efficacy in a copper-dependent manner and kills pathogens across three different kingdoms, Streptococcus pneumoniae ( Sr. pneumoniae ), Coccidioides posadasii , and Schistosoma mansoni , and in vivo efficacy against Sr . pneumoniae .

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