Co-infection between influenza virus and flagellated bacteria.
Abstract: Trypsin is required in the hemagglutinin (HA) cleavage to in vitro influenza viruses activation. This HA cleavage is necessary for virus cell entry by receptor-mediated endocytosis. Bacteria in the respiratory tract are potential sources of proteases that could contribute to the cleavage of influenza virus in vivo. From 47 samples collected from horses, pigs, and from humans, influenza presence was confirmed in 13 and these samples demonstrated co-infection of influenza with flagellated bacteria, Stenotrophomonas maltophilia from the beginning of the experiments. Despite treatment with antibiotics, the bacteria remained resistant in several of the co-infected samples (48.39%). These bacteria, considered opportunistic invaders from environmental sources, are associated with viral infections in upper respiratory tract of hosts. The protease (elastase), secreted by Stenotrophomonas maltophilia plays a role in the potentiation of influenza virus infection. Proteolytic activity was detected by casein agar test. Positive samples from animals and humans had either a potentiated influenza infectivity or cytopathic effect (CPE) in MDCK and NCI H292 cells, Stenotrophomonas maltophilia were always present. Virus and bacteria were observed ultrastructurally. These in vitro findings show that microbial proteases could contribute to respiratory complications by host protease activity increasing inflammation or destroying endogenous cell protease inhibitors.
Publication Date: 2005-11-16 PubMed ID: 16302111DOI: 10.1590/s0036-46652005000500007Google Scholar: Lookup
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- Journal Article
- Research Support
- Non-U.S. Gov't
Summary
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This research studied the co-infection of the influenza virus and flagellated bacteria, specifically Stenotrophomonas maltophilia, in humans and animals. It discovered that the bacteria’s protease can increase the potency of the flu infection by breaking down the virus’ hemagglutinin, a necessary step for the virus to enter cells.
Research Objective and Methodology
- The aim of the research was to explore the potential link between the presence of certain bacteria in the respiratory tract and their contribution to the severity of an influenza virus infection.
- The study involved collecting samples from humans, horses, and pigs to test for the presence of influenza and Stenotrophomonas maltophilia.
- The researchers used the casein agar test to detect proteolytic activity, that is, the process of breaking down proteins into smaller polypeptides or amino acids.
- Cell structures or ultrastructures of the virus and bacteria were observed through microscopic analysis.
Findings and Implications
- Out of 47 samples, 13 showed the presence of both the influenza virus and the flagellated bacteria, Stenotrophomonas maltophilia.
- The study found that despite antibiotic treatment, the bacteria remained resistant in almost half of the co-infected samples.
- Through microscopic observations, the researchers found that flu virus activation was being propelled by the protease (an enzyme that performs proteolysis, protein degradation) secreted by Stenotrophomonas maltophilia.
- The protease had the capability to break down hemagglutinin (HA), a crucial process in the activation of the influenza virus.
- The role of the bacterial protease in increasing the potency of the influenza virus infection suggests that it could contribute to severe respiratory complications in infected hosts.
Conclusion
- The findings provide an insight into how microbial proteases—like the one secreted by Stenotrophomonas maltophilia—may contribute to the severity of flu infections.
- These bacteria, typically viewed as opportunistic invaders from environmental sources, are linked to viral infections in the host’s upper respiratory tract.
- This research pushes for more studies to understand the relationships and interactions between viruses, bacteria, and their hosts, which could eventually lead to the development of more effective treatments.
Cite This Article
APA
Mancini DA, Mendonça RM, Dias AL, Mendonça RZ, Pinto JR.
(2005).
Co-infection between influenza virus and flagellated bacteria.
Rev Inst Med Trop Sao Paulo, 47(5), 275-280.
https://doi.org/10.1590/s0036-46652005000500007 Publication
Researcher Affiliations
- Divisão de Desenvolvimento Científico, Instituto Butantan, S. Paulo, SP, Brazil. dapmancini@butantan.gov.br
MeSH Terms
- Animals
- Cattle
- Enzyme Activation
- Gram-Negative Bacterial Infections / complications
- Gram-Negative Bacterial Infections / microbiology
- Horses
- Humans
- Influenza, Human / complications
- Influenza, Human / microbiology
- Microscopy, Electron
- Orthomyxoviridae / isolation & purification
- Orthomyxoviridae / pathogenicity
- Orthomyxoviridae / ultrastructure
- Orthomyxoviridae Infections / complications
- Orthomyxoviridae Infections / microbiology
- Pancreatic Elastase / biosynthesis
- Stenotrophomonas maltophilia / enzymology
- Stenotrophomonas maltophilia / isolation & purification
- Swine
- Virus Activation
Citations
This article has been cited 12 times.- Mikušová M, Tomčíková K, Briestenská K, Kostolanský F, Varečková E. The Contribution of Viral Proteins to the Synergy of Influenza and Bacterial Co-Infection. Viruses 2022 May 16;14(5).
- Abdelaziz AM, Mohamed MHA, Fayez MM, Al-Marri T, Qasim I, Al-Amer AA. Molecular survey and interaction of common respiratory pathogens in chicken flocks (field perspective). Vet World 2019 Dec;12(12):1975-1986.
- Ismail ZM, El-Deeb AH, El-Safty MM, Hussein HA. Enhanced pathogenicity of low-pathogenic H9N2 avian influenza virus after vaccination with infectious bronchitis live attenuated vaccine. Vet World 2018 Jul;11(7):977-985.
- Hassan KE, Ali A, Shany SAS, El-Kady MF. Experimental co-infection of infectious bronchitis and low pathogenic avian influenza H9N2 viruses in commercial broiler chickens. Res Vet Sci 2017 Dec;115:356-362.
- Safaeyan F, Nahaei MR, Seifi SJ, Kafil HS, Sadeghi J. Quantitative detection of Staphylococcus aureus, Streptococcus pneumoniae and Haemophilus influenzae in patients with new influenza A (H1N1)/2009 and influenza A/2010 virus infection. GMS Hyg Infect Control 2015;10:Doc06.
- Hou D, Bi Y, Sun H, Yang J, Fu G, Sun Y, Liu J, Pu J. Identification of swine influenza A virus and Stenotrophomonas maltophilia co-infection in Chinese pigs. Virol J 2012 Aug 22;9:169.
- Brooke JS. Stenotrophomonas maltophilia: an emerging global opportunistic pathogen. Clin Microbiol Rev 2012 Jan;25(1):2-41.
- King MD, Guentzel MN, Arulanandam BP, Bodour AA, Brahmakshatriya V, Lupiani B, Chambers JP. Effects of bacterial microflora of the lower digestive tract of free-range waterfowl on influenza virus activation. Appl Environ Microbiol 2011 Jun;77(12):4119-25.
- Haghighat-Jahromi M, Asasi K, Nili H, Dadras H, Shooshtari AH. Coinfection of avian influenza virus (H9N2 subtype) with infectious bronchitis live vaccine. Arch Virol 2008;153(4):651-5.
- Sakudo A. Effect of combined infection with Salmonella and influenza virus on their respective proliferation in chicken embryonated eggs. Open Vet J 2024 Mar;14(3):913-918.
- Xu W, Wang Q, Li L, Zhu B, Cai Q, Yi X, Fang R, Wang Q. Case Report: Metagenomic next-generation sequencing applied in diagnosing psittacosis caused by Chlamydia psittaci infection. Front Cell Infect Microbiol 2023;13:1249225.
- Wang Y, He T, Shen Z, Wu C. Antimicrobial Resistance in Stenotrophomonas spp. Microbiol Spectr 2018 Jan;6(1).
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