scholarly journals Synergism and antagonism of bacterial-viral co-infection in the upper respiratory tract

2020 ◽  
Author(s):  
Sam Manna ◽  
Julie McAuley ◽  
Jonathan Jacobson ◽  
Cattram D. Nguyen ◽  
Md Ashik Ullah ◽  
...  

ABSTRACTStreptococcus pneumoniae (the pneumococcus) is a leading cause of pneumonia in children under five years old. Co-infection by pneumococci and respiratory viruses enhances disease severity. Little is known about pneumococcal co-infections with Respiratory Syncytial Virus (RSV). Here, we developed a novel infant mouse model of co-infection using Pneumonia Virus of Mice (PVM), a murine analogue of RSV, to examine the dynamics of co-infection in the upper respiratory tract, an anatomical niche that is essential for host-to-host transmission and progression to disease. Coinfection increased damage to the nasal tissue and increased production of the chemokine CCL3. Pneumococcal nasopharyngeal density and shedding in nasal secretions were increased by co-infection. In contrast, co-infection reduced PVM loads in the nasopharynx, an effect that was independent of pneumococcal strain and the order of infection. We showed this ‘antagonistic’ effect was abrogated using a pneumococcal mutant deficient in capsule production and incapable of nasopharyngeal carriage. The pneumococcal-mediated reduction in PVM loads was caused by accelerated viral clearance from the nasopharynx. Although these synergistic and antagonistic effects occurred with both wild-type pneumococcal strains used in this study, the magnitude of the effects was strain dependent. Lastly, we showed that pneumococci can also antagonize influenza virus. Taken together, our study has uncovered multiple novel facets of bacterial-viral co-infection. Our findings have important public health implications, including for bacterial and viral vaccination strategies in young children.

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Cheng Lei ◽  
Lisong Yang ◽  
Cheong Tat Lou ◽  
Fan Yang ◽  
Kin Ian SiTou ◽  
...  

Abstract Background Acute respiratory infections (ARIs) are among the leading causes of hospitalization in children. Understanding the local dominant viral etiologies is important to inform infection control practices and clinical management. This study aimed to investigate the viral etiology and epidemiology of respiratory infections among pediatric inpatients in Macao. Methods A retrospective study using electronic health records between 2014 and 2017 at Kiang Wu Hospital was performed. Nasopharyngeal swab specimens were obtained from hospitalized children aged 13 years or younger with respiratory tract diseases. xMAP multiplex assays were employed to detect respiratory agents including 10 respiratory viruses. Data were analyzed to describe the frequency and seasonality. Results Of the 4880 children enrolled in the study, 3767 (77.1%) were positive for at least one of the 13 viral pathogens tested, of which 2707 (55.5%) being male and 2635 (70.0%) under 2 years old. Among the positive results, there were 3091 (82.0%) single infections and 676 (18.0%) multiple infections. The predominant viruses included human rhinovirus/enterovirus (HRV/EV 27.4%), adenovirus (ADV, 15.8%), respiratory syncytial virus B (RSVB, 7.8%) and respiratory syncytial virus A (RSVA, 7.8%). The detection of viral infection was the most prevalent in autumn (960/1176, 81.6%), followed by spring (1095/1406, 77.9%), winter (768/992, 77.4%), and summer (944/1306, 72.3%), with HRV/EV and ADV being most commonly detected throughout the 4 years of study period. The detection rate of viral infection was highest among ARI patients presented with croup (123/141, 87.2%), followed by lower respiratory tract infection (1924/2356, 81.7%) and upper respiratory tract infection (1720/2383, 72.2%). FluA, FluB and ADV were positive factors for upper respiratory tract infections. On the other hand, infection with RSVA, RSVB, PIV3, PIV4, HMPV, and EV/RHV were positively associated with lower respiratory tract infections; and PIV1, PIV2, and PIV3 were positively associated with croup. Conclusions This is the first study in Macao to determine the viral etiology and epidemiology of pediatric patients hospitalized for ARIs. The study findings can contribute to the awareness of pathogen, appropriate preventative measure, accurate diagnosis, and proper clinical management of respiratory viral infections among children in Macao.


Author(s):  
Dr Mark Harrison

15.1 Rhinovirus, 209 15.2 Influenza, 210 15.3 Parainfluenza, 211 15.4 Respiratory syncytial virus (RSV), 211 • There are more than 100 different serotypes of rhinovirus. • Rhinovirus is chiefly limited to upper respiratory tract infections and is the major cause of the common cold....


mBio ◽  
2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tonia Zangari ◽  
Mila B. Ortigoza ◽  
Kristen L. Lokken-Toyli ◽  
Jeffrey N. Weiser

ABSTRACT The dynamics underlying respiratory contagion (the transmission of infectious agents from the airways) are poorly understood. We investigated host factors involved in the transmission of the leading respiratory pathogen Streptococcus pneumoniae. Using an infant mouse model, we examined whether S. pneumoniae triggers inflammatory pathways shared by influenza A virus (IAV) to promote nasal secretions and shedding from the upper respiratory tract to facilitate transit to new hosts. Here, we show that amplification of the type I interferon (IFN-I) response is a critical host factor in this process, as shedding and transmission by both IAV and S. pneumoniae were decreased in pups lacking the common IFN-I receptor (Ifnar1−/− mice). Additionally, providing exogenous recombinant IFN-I to S. pneumoniae-infected pups was sufficient to increase bacterial shedding. The expression of IFN-stimulated genes (ISGs) was upregulated in S. pneumoniae-infected wild-type (WT) but not Ifnar1−/− mice, including genes involved in mucin type O-glycan biosynthesis; this correlated with an increase in secretions in S. pneumoniae- and IAV-infected WT compared to Ifnar1−/− pups. S. pneumoniae stimulation of ISGs was largely dependent on its pore-forming toxin, pneumolysin, and coinfection with IAV and S. pneumoniae resulted in synergistic increases in ISG expression. We conclude that the induction of IFN-I signaling appears to be a common factor driving viral and bacterial respiratory contagion. IMPORTANCE Respiratory tract infections are a leading cause of childhood mortality and, globally, Streptococcus pneumoniae is the leading cause of mortality due to pneumonia. Transmission of S. pneumoniae primarily occurs through direct contact with respiratory secretions, although the host and bacterial factors underlying transmission are poorly understood. We examined transmission dynamics of S. pneumoniae in an infant mouse model and here show that S. pneumoniae colonization of the upper respiratory tract stimulates host inflammatory pathways commonly associated with viral infections. Amplification of this response was shown to be a critical host factor driving shedding and transmission of both S. pneumoniae and influenza A virus, with infection stimulating expression of a wide variety of genes, including those involved in the biosynthesis of mucin, a major component of respiratory secretions. Our findings suggest a mechanism facilitating S. pneumoniae contagion that is shared by viral infection.


2019 ◽  
Vol 71 (11) ◽  
pp. 2777-2786 ◽  
Author(s):  
Roy F Chemaly ◽  
Sanjeet S Dadwal ◽  
Anne Bergeron ◽  
Per Ljungman ◽  
Yae-Jean Kim ◽  
...  

Abstract Background Hematopoietic-cell transplant (HCT) recipients are at risk for severe respiratory syncytial virus (RSV) infection. We evaluated the RSV fusion inhibitor presatovir in a randomized, double-blind, Phase II trial in HCT recipients with RSV upper respiratory tract infections. Methods Patients were stratified by lymphopenia (<200/µL) and ribavirin use; were randomized, stratified by lymphopenia (<200/μL) and ribavirin use, to receive oral presatovir at 200 mg or a placebo on Days 1, 5, 9, 13, and 17, and were followed through Day 28. The coprimary efficacy endpoints were the time-weighted average change in the nasal RSV viral load between Days 1 and 9 and the proportion of patients developing lower respiratory tract complications (LRTCs) through Day 28. Results From 23 January 2015 to 16 June 2017, 189 patients were randomly assigned to treatment (96 to presatovir and 93 to the placebo). Presatovir treatment, compared with the placebo treatment, did not significantly affect (prespecified α = 0.01) a time-weighted average decline in the RSV viral load from Day 1 to 9 (treatment difference, −0.33 log10 copies/mL; 95% confidence interval [CI] −.64 to −.02 log10 copies/mL; P = .040) or the progression to LRTC (11.2% vs 19.5%, respectively; odds ratio, 0.50; 95% CI, .22–1.18; P = .11). In a post hoc analysis among patients with lymphopenia, presatovir decreased LRTC development by Day 28 (2/15 [13.3%] vs 9/14 [64.3%], respectively; P = .008), compared with the placebo. Adverse events were similar for patients receiving presatovir and the placebo. Conclusions Presatovir had a favorable safety profile in adult HCT recipients with RSV but did not achieve the coprimary endpoints. Exploratory analyses suggest an antiviral effect among patients with lymphopenia. Clinical Trials Registration NCT02254408; EUDRA-CT#2014-002474-36.


2010 ◽  
Vol 8 (2) ◽  
pp. 197-199 ◽  
Author(s):  
Amilton Mouro ◽  
Luci Black Tabacow Hidal ◽  
Marines Dalla Valle Martino ◽  
Jacyr Pasternark

ABSTRACT Objective: To evaluate the prevalence of pathogens in the upper respiratory tract according to age at a tertiary care hospital in the city of São Paulo. Methods: A total of 6,144 biological material tests from upper respiratory airways were analyzed: 740 bacterial cultures, 726 virus screenings and 4,678 rapid tests for S. pyogenes. Results: The most frequently found etiological agent was respiratory syncytial virus (29.6%; 215/726). The main agents detected per age groups were: respiratory syncytial virus (25.34%; 184/726) in patients aged 28 days-3 years; S. pyogenes (9.5%; 70/740) in 3-12 year-old children; influenza virus (8.8%; 64/726) in adults (18-59 years). Conclusions: The etiologic agents of upper respiratory infections vary according to age and imply diverse clinical and therapeutic management.


Intervirology ◽  
2008 ◽  
Vol 51 (2) ◽  
pp. 112-115 ◽  
Author(s):  
Jesus F. Bermejo-Martin ◽  
Alberto Tenorio ◽  
Raul Ortiz de Lejarazu ◽  
Jose M. Eiros ◽  
Vanesa Matías ◽  
...  

1990 ◽  
Vol 105 (3) ◽  
pp. 609-618 ◽  
Author(s):  
K. G. Nicholson ◽  
D. J. Baker ◽  
A. Farquhar ◽  
D. Hurd ◽  
J. Kent ◽  
...  

SUMMARYOccupants of 482 long-stay and 33 short-stay beds in 11 Leicester City Council homes for the elderly were studied during a 30-week period from September 1988 to March 1989 to determine the incidence, aetiology, morbidity, and mortality of acute upper respiratory tract viral infections and the use of influenza vaccine.Influenza immunization rates by home ranged from 15·4 to 90% (mean 45%). There were no differences in the distribution of medical conditions by home. The highest immunization rates were seen in people with chest disease (77%), heart disease (60%), diabetes (56%), and those with three medical conditions (75%). There was an average of 0·7 upper respiratory episodes per bed per annum with a mortality of 3·4% (6/179). Half of all episodes were seen by a general medical practitioner and 81 of 90 (90%) referrals were prescribed antibiotics costing approximately £7.50 per patient. Lower respiratory tract complications developed during 45 (25%) of 179 episodes including 3 of 12 coronavirus infections, 3 of 9 respiratory syncytial virus infections, 2 of 4 adenovirus infections, 1 of 11 rhinovirus infections, but none of 5 influenza infections. Respiratory infections were caused mostly by pathogens other than influenza virus during the influenza period documented nationally. This highlights the role of coronaviruses, respiratory syncytial virus, and unidentified agents in the elderly, and questions the assumptions made in American estimates on the impact of influenza and the value of influenza vaccines.


2019 ◽  
Vol 1 (1) ◽  
pp. 104-110 ◽  
Author(s):  
E. P. Foshina ◽  
T. A. Serova ◽  
I. B. Bisheva ◽  
O. V. Slatinova

Aim.To study the level of specific antibodies of different isotypes to the antigens of Staphylococcus aureus and Klebsiella рneumoniae in the serum, saliva and nazal secret and the concentration of IgA,sIgA,IgG in saliva from frequently and long-term ill children in nasal-oral administration of Immunovac VP-4.Materials and methods.Specific antibodies to S. aureus and K.pneumoniae, contained in saliva, nasal, and serum were determined by the method of enzyme immunoassay. Concentrations of immunoglobulins of classes G, A and sА in saliva were determined by radial immunodiffusion using a commercial kit produced by the NPC «Medical immunology».Results. The high level of specific antibodies contained in the serum and nasal secretions, the level of antibodies in saliva is negligible. The serum is dominated by IgG-isotype antibodies, saliva and nasal secret — antibodies of IgA-isotope. After the introduction of Immunovac VP-4 there was a statistically significant increase in the level of specific antibacterial antibodies in serum, saliva and nasal secret, and increasing levels of IgG and sIgA in saliva.Conclusion. Obtained data demonstratet that the nasal-oral scheme of administration of Immunovac VP-4 frequently and long-term ill children allowed to increase the level of specific antibodies in serum, saliva and nasal secret to bacterial antigens that are part of the vaccine and to normalize the local synthesis of IgG and sIgA, which play a major role in the protection of the respiratory tract and mucous membranes of the upper respiratory tract.


mSphere ◽  
2020 ◽  
Vol 5 (6) ◽  
Author(s):  
L. Patrick Schenck ◽  
Joshua J. C. McGrath ◽  
Daphnée Lamarche ◽  
Martin R. Stämpfli ◽  
Dawn M. E. Bowdish ◽  
...  

ABSTRACT Respiratory infections are a leading cause of morbidity and mortality worldwide. Bacterial pathogens often colonize the upper respiratory tract (nose or mouth) prior to causing lower respiratory infections or invasive disease. Interactions within the upper respiratory tract between colonizing bacteria and the resident microbiota could contribute to colonization success and subsequent transmission. Human carriage studies have identified associations between pathogens such as Streptococcus pneumoniae and members of the resident microbiota, although few mechanisms of competition and cooperation have been identified and would be aided by the use of animal models. Little is known about the composition of the murine nasal microbiota; thus, we set out to improve assessment, including tissue sampling, composition, and comparison between mouse sources. Nasal washes were efficient in sampling the nasopharyngeal space but barely disrupted the nasal turbinates. Nasal tissue extraction increased the yield of cultivable bacterial compared to nasal washes, revealing distinct community compositions. Experimental pneumococcal colonization led to dominance by the colonizing pathogen in the nasopharynx and nasal turbinates, but the composition of the microbiota, and interactions with resident microbes, differed depending on the sampling method. Importantly, vendor source has a large impact on microbial composition. Bacterial interactions, including cooperation and colonization resistance, depend on the biogeography of the nose and should be considered during research design of experimental colonization with pathogens. IMPORTANCE The nasal microbiota is composed of species that play a role in the colonization success of pathogens, including Streptococcus pneumoniae and Staphylococcus aureus. Murine models provide the ability to explore disease pathogenesis, but little is known about the natural murine nasal microbiota. This study established techniques to allow the exploration of the bacterial members of the nasal microbiota. The mouse nasal microbiota included traditional respiratory bacteria, including Streptococcus, Staphylococcus, and Moraxella species. Analyses were affected by different sampling methods as well as the commercial source of the mice, which should be included in future research design of infectious disease research.


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