Influencer Marketing and Behavioral Outcomes in Social Media: Systematic Literature Review

Influencer Marketing (also called Influence Marketing) is a communication method responding to major issues that brands and communication agencies encounter when communicating with their targets on social networks. Given the continual change in communication methods, brands must be creative in developing effective processes capable of reaching consumers who are averse to intrusive advertisements. Going through an influencer gives the campaign credibility with a more authentic and closer message, relayed by an opinion leader. The purpose of this paper is to review the academic literature on influencer marketing and its behavioral outcomes on social media to highlight the current state of the art, the key research themes and the implications for management research and practice. A systematic literature review of academic research on social media influencer marketing has been conducted to gather, examine and synthesize studies related to behavioral outcomes that result from thesis communication methods. By following a review protocol based on both automatic and manual search for the Scopus and Web of science database, all relevant studies on influencer marketing were identified and analyzed.  Following the results identified by a critical conceptualization of the concept of influence marketing. The main key research topics covered were categorized and divided into four main areas which were further analyzed: The influence of SMIs communication strategy on user/consumer behavior; Influencer-Follower interpersonal relationship; Social media endorsements and the perception of SMIs as human brands; Celebrity level of SMIs and their congruence with brand endorsements are the main themes that have been mostly identified and discussed in our study.   JEL classification: M31 Paper type: Theoretical ResearchInfluencer Marketing (also called Influence Marketing) is a communication method responding to major issues that brands and communication agencies encounter when communicating with their targets on social networks. Given the continual change in communication methods, brands must be creative in developing effective processes capable of reaching consumers who are averse to intrusive advertisements. Going through an influencer gives the campaign credibility with a more authentic and closer message, relayed by an opinion leader. The purpose of this paper is to review the academic literature on influencer marketing and its behavioral outcomes on social media to highlight the current state of the art, the key research themes and the implications for management research and practice. A systematic literature review of academic research on social media influencer marketing has been conducted to gather, examine and synthesize studies related to behavioral outcomes that result from thesis communication methods. By following a review protocol based on both automatic and manual search for the Scopus and Web of science database, all relevant studies on influencer marketing were identified and analyzed.  Following the results identified by a critical conceptualization of the concept of influence marketing. The main key research topics covered were categorized and divided into four main areas which were further analyzed: The influence of SMIs communication strategy on user/consumer behavior; Influencer-Follower interpersonal relationship; Social media endorsements and the perception of SMIs as human brands; Celebrity level of SMIs and their congruence with brand endorsements are the main themes that have been mostly identified and discussed in our study.   JEL classification: M31 Paper type: Theoretical Researc

Understanding Influencer Marketing in the Gaming Industry: The role of social influence and engagement

The gaming industry is experiencing rapid growth, and influence marketing has become an essential tool for brands seeking to reach gamers. Based on a narrative literature review, this study aims to explore the role of social influence in the context of influence marketing in the gaming industry, with a focus on the impact of user engagement. Drawing upon social influence theory and the concept of social congruity, we propose a conceptual model that connects these key variables. The model suggests that social influence exerted by gaming influencers on social media can influence user engagement. The expected results of this study will contribute to a better understanding of the role of social influence in influencer marketing within the gaming industry. Furthermore, the proposed conceptual model will provide insights for marketing professionals to optimize their influence strategies and enhance user engagement among gamers.   Keywords: influence marketing, gaming, social influence, engagement, social congruity, conceptual model. JEL Classification: M31 Paper type:  theoretical researchL'industrie du gaming connaît une expansion fulgurante, et le marketing d'influence est devenu un outil incontournable pour les marques cherchant à atteindre les joueurs. Cette étude vise à explorer le rôle de l'influence sociale dans le contexte du marketing d'influence dans l'industrie du gaming, en mettant l'accent sur l'impact de l'engagement des utilisateurs gamers. En nous appuyant sur la théorie de l'influence sociale et le concept de congruité sociale, nous proposons un modèle conceptuel qui met en relation ces variables clés. Le modèle suggère que l'influence sociale exercée par les influenceurs gamers sur les réseaux sociaux peut influencer l'engagement des utilisateurs gamers. Nous posons l'hypothèse que plus l'influence sociale perçue est élevée, plus l'engagement des utilisateurs gamers sera fort. Pour étayer notre modèle, nous proposons une méthodologie de recherche incluant une enquête auprès d'un échantillon de joueurs réguliers. Les données recueillies seront analysées à l'aide d'analyses statistiques pour évaluer les relations entre l'influence sociale, la congruité sociale et l'engagement des utilisateurs gamers. Les résultats attendus de cette étude contribueront à une meilleure compréhension du rôle de l'influence sociale dans le marketing d'influence de l'industrie du gaming. En outre, le modèle conceptuel proposé fournira des pistes pour les professionnels du marketing afin d'optimiser leurs stratégies d'influence et de renforcer l'engagement des utilisateurs gamers.   Mots-clés : marketing d'influence, gaming, influence sociale, engagement, congruité sociale, modèle conceptuel Classification JEL: M31 Type d’article:  Recherche théoriqu

Rapid and Simple Universal Escherichia coli Genotyping Method Based on Multiple-Locus Variable-Number Tandem-Repeat Analysis Using Single-Tube Multiplex PCR and Standard Gel Electrophoresis

International audienceWe developed a multiplex PCR method based on multiple-locus variable-number tandem-repeat (VNTR) analysis (MLVA) that was designed for the rapid typing of Escherichia coli and Shigella isolates. The method amplifies seven VNTRs and does not require a sequencing capillary or fluorescent dyes. The amplification products are simply loaded on a standard agarose gel for electrophoresis, and the banding patterns are analyzed visually. We evaluated the method on 220 strains belonging to different collections: the E. coli reference (ECOR) collection (n = 72), O1:K1 isolates causing neonatal meningitis (n = 38), extended-spectrum beta-lactamase-producing fecal isolates belonging to the worldwide sequence type 131 (ST131) clone (n = 38), Shiga toxin-producing E. coli (STEC) isolates of serogroups O157:H7 (n = 21) and O26 (n = 16, 8 of which belonged to an outbreak), 27 Shigella isolates (22 Shigella sonnei isolates, including 5 epidemic strains), and 8 reference strains. The performances were compared to those of multilocus sequence typing (MLST), the DiversiLab automated repetitive element palindromic PCR (REP-PCR), pulsed-field gel electrophoresis (PFGE), and whole-genome sequencing (WGS). We found 66 different profiles among the isolates in the ECOR collection. Among the clonal group O1:K1 isolates, 14 different profiles were identified. For the 37 STEC isolates, we found 23 profiles, with 1 corresponding to the 8 epidemic strains. We found 19 profiles among the 27 Shigella isolates, with 1 corresponding to the epidemic strain. The method was able to recognize strains of the ST131 clone and to distinguish the O16 and O25b serogroups and identified 15 different MLVA types among them. This method allows the simple, fast, and inexpensive typing of E. coli/Shigella isolates that can be carried out in any laboratory equipped for molecular biology and has a discriminatory power superior to that of MLST and DiversiLab REP-PCR but slightly lower than that of PFGE.IMPORTANCE Fast typing methods that can easily and accurately distinguish clonal groups and unrelated isolates are of particular interest for microbiologists confronted with outbreaks or performing epidemiological studies. Highly discriminatory universal methods, like PFGE, optical mapping, or WGS, are expensive and/or time-consuming. MLST is useful for phylogeny but is less discriminatory and requires sequencing facilities. PCR methods, which are fast and easy to perform, also have drawbacks. Random PCRs and REP-PCR are universal but lack reproducibility. Other PCR methods may lack the discriminatory power to differentiate isolates during outbreaks. MLVA combines the advantages of PCR methods with a high discriminatory power but in its standard form requires sequencing capillary electrophoresis. The method that we have developed combines the advantages of standard PCR (simple, fast, and inexpensive) with the high discriminatory power of MLVA and permits the typing of all E. coli isolates (either intestinal or extraintestinal pathogenic isolates as well as commensal isolates)

Role of astroglial Connexin 43 in pneumolysin cytotoxicity and during pneumococcal meningitis.

Streptococcus pneumoniae or pneumococcus (PN) is a major causative agent of bacterial meningitis with high mortality in young infants and elderly people worldwide. The mechanism underlying PN crossing of the blood brain barrier (BBB) and specifically, the role of non-endothelial cells of the neurovascular unit that control the BBB function, remains poorly understood. Here, we show that the astroglial connexin 43 (aCx43), a major gap junctional component expressed in astrocytes, plays a predominant role during PN meningitis. Following intravenous PN challenge, mice deficient for aCx43 developed milder symptoms and showed severely reduced bacterial counts in the brain. Immunofluorescence analysis of brain slices indicated that PN induces the aCx43-dependent destruction of the network of glial fibrillary acid protein (GFAP), an intermediate filament protein specifically expressed in astrocytes and up-regulated in response to brain injury. PN also induced nuclear shrinkage in astrocytes associated with the loss of BBB integrity, bacterial translocation across endothelial vessels and replication in the brain cortex. We found that aCx4-dependent astrocyte damages could be recapitulated using in vitro cultured cells upon challenge with wild-type PN but not with a ply mutant deficient for the pore-forming toxin pneumolysin (Ply). Consistently, we showed that purified Ply requires Cx43 to promote host cell plasma membrane permeabilization in a process involving the Cx43-dependent release of extracellular ATP and prolonged increase of cytosolic Ca2+ in host cells. These results point to a critical role for astrocytes during PN meningitis and suggest that the cytolytic activity of the major virulence factor Ply at concentrations relevant to bacterial infection requires co-opting of connexin plasma membrane channels

Enterohemorrhagic Escherichia coli Hybrid Pathotype O80:H2 as a New Therapeutic Challenge

We describe the epidemiology, clinical features, and molecular characterization of enterohemorrhagic Escherichia coli (EHEC) infections caused by the singular hybrid pathotype O80:H2, and we examine the influence of antibiotics on Shiga toxin production. In France, during 2005–2014, a total of 54 patients were infected with EHEC O80:H2; 91% had hemolytic uremic syndrome. Two patients had invasive infections, and 2 died. All strains carried stx2 (variants stx2a, 2c, or 2d); the rare intimin gene (eae-ξ); and at least 4 genes characteristic of pS88, a plasmid associated with extraintestinal virulence. Similar strains were found in Spain. All isolates belonged to the same clonal group. At subinhibitory concentrations, azithromycin decreased Shiga toxin production significantly, ciprofloxacin increased it substantially, and ceftriaxone had no major effect. Antibiotic combinations that included azithromycin also were tested. EHEC O80:H2, which can induce hemolytic uremic syndrome complicated by bacteremia, is emerging in France. However, azithromycin might effectively combat these infections

Identification of aryl hydrocarbon receptor as a barrier to HIV-1 infection and outgrowth in CD4+ T cells

Summary: The aryl hydrocarbon receptor (AhR) regulates Th17-polarized CD4+ T cell functions, but its role in HIV-1 replication/outgrowth remains unknown. Genetic (CRISPR-Cas9) and pharmacological inhibition reveal AhR as a barrier to HIV-1 replication in T cell receptor (TCR)-activated CD4+ T cells in vitro. In single-round vesicular stomatitis virus (VSV)-G-pseudotyped HIV-1 infection, AhR blockade increases the efficacy of early/late reverse transcription and subsequently facilitated integration/translation. Moreover, AhR blockade boosts viral outgrowth in CD4+ T cells of people living with HIV-1 (PLWH) receiving antiretroviral therapy (ART). Finally, RNA sequencing reveals genes/pathways downregulated by AhR blockade in CD4+ T cells of ART-treated PLWH, including HIV-1 interactors and gut-homing molecules with AhR-responsive elements in their promoters. Among them, HIC1, a repressor of Tat-mediated HIV-1 transcription and a tissue-residency master regulator, is identified by chromatin immunoprecipitation as a direct AhR target. Thus, AhR governs a T cell transcriptional program controlling viral replication/outgrowth and tissue residency/recirculation, supporting the use of AhR inhibitors in “shock and kill” HIV-1 remission/cure strategies

Identification of Aryl Hydrocarbon Receptor as a Barrier to HIV-1 Infection and Outgrowth in CD4+ T-Cells

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