18 research outputs found
IMPACT OF SUPERVISOR - SUBORDINATE RELATIONSHIP ON ENVY, KNOWLEDGE SHARING, AND RELATIONAL CONFLICT AMONG EMPLOYEES: A PILOT STUDY
Envy has been relatively ignored in organizational behavior research. In this study, we focus on the impact of leader member exchange on envy. In addition, we also investigate the consequences of envy in terms of employee knowledge sharing and relational conflict. Building on Affective events theory, we argue that employees who do not have a good relationship with their supervisors (low quality LMX) will exhibit higher levels of envy and eventually will restrict their knowledge sharing and engage in relational conflict in the workplace. PLS based SEM was applied to the data derived from a sample of forty three software engineers. Results of the study provide support to three of the proposed hypotheses. This study contributes to the field by demonstrating the negative consequences of envy in the workplace. Practical implications of the study and some interesting avenues for future research are also discussed
AN INTERNATIONAL PERSPECTIVE CONCERNING IMPACT OF SUPERVISOR - SUBORDINATE RELATIONSHIP ON ENVY, KNOWLEDGE SHARING, AND RELATIONAL CONFLICT AMONG EMPLOYEES
Envy has been relatively ignored in organizational behavior research. In this study, we focus on the impact of supervisor subordinate relationship (LMX) on envy. In addition, we also investigate the consequences of envy in terms of employee knowledge sharing and relational conflict. Building on Affective events theory, we argue that employees who do not have a good relationship with their supervisors (low quality LMX) will exhibit higher levels of envy. As a result, they will restrict their knowledge sharing, and engage in relational conflict in the workplace. Partial least squares based structural equation modeling was applied to the data derived from a sample of one hundred sixty one software engineers working across various information technology firms in India. Results of the study provide support to three of the proposed hypotheses. This study contributes to the field by demonstrating the negative consequences of envy in the workplace. Practical implications of the study and some interesting avenues for future research are also discussed
Optimism in Music Piracy: A Pilot Study
Piracy continues to be a threat to global economy. Previous literature on factors influencing individualâs attitude towards piracy indicates that as perceived risk increases, individuals attitude of acceptance of piracy should decrease. In spite of the increased risks, some people pirate, there has been no explanation for this apparent paradox. We try to explain this paradox by using the concept of optimism bias. Results of our study show that individuals having an optimism bias engage in piracy because they consider themselves at low risk than average compared to the group
Reciprocal Interactions between Nematodes and Their Microbial Environments
Parasitic nematode infections are widespread in nature, affecting humans as
well as wild, companion, and livestock animals. Most parasitic nematodes
inhabit the intestines of their hosts living in close contact with the
intestinal microbiota. Many species also have tissue migratory life stages in
the absence of severe systemic inflammation of the host. Despite the close
coexistence of helminths with numerous microbes, little is known concerning
these interactions. While the environmental niche is considerably different,
the free-living nematode Caenorhabditis elegans (C. elegans) is also found
amongst a diverse microbiota, albeit on decaying organic matter. As a very
well characterized model organism that has been intensively studied for
several decades, C. elegans interactions with bacteria are much more deeply
understood than those of their parasitic counterparts. The enormous breadth of
understanding achieved by the C. elegans research community continues to
inform many aspects of nematode parasitology. Here, we summarize what is known
regarding parasitic nematode-bacterial interactions while comparing and
contrasting this with information from work in C. elegans. This review
highlights findings concerning responses to bacterial stimuli, antimicrobial
peptides, and the reciprocal influences between nematodes and their
environmental bacteria. Furthermore, the microbiota of nematodes as well as
alterations in the intestinal microbiota of mammalian hosts by helminth
infections are discussed
CD4+ Th immunogenicity of the Ascaris spp. secreted products
Ascaris spp. is a major health problem of humans and animals alike, and understanding the immunogenicity of its antigens is required for developing urgently needed vaccines. The parasite-secreted products represent the most relevant, yet complex (>250 proteins) antigens of Ascaris spp. as defining the pathogen-host interplay. We applied an in vitro antigen processing system coupled to quantitative proteomics to identify potential CD4+ Th cell epitopes in Ascaris-secreted products. This approach considerably restricts the theoretical list of epitopes using conventional CD4+ Th cell epitope prediction tools. We demonstrate the specificity and utility of our approach on two sets of candidate lists, allowing us identifying hits excluded by either one or both computational methods. More importantly, one of the candidates identified experimentally, clearly demonstrates the presence of pathogen-reactive T cells in healthy human individuals against these antigens. Thus, our work pipeline identifies the first human T cell epitope against Ascaris spp. and represents an easily adaptable platform for characterization of complex antigens, in particular for those pathogens that are not easily amenable for in vivo experimental validation
Trilateral Relationship: Ascaris, Microbiota, and Host Cells
Ascariasis is a globally spread intestinal nematode infection of humans and a considerable concern in pig husbandry. Ascaris accomplishes a complex body migration from the intestine via the liver and lung before returning to the intestine. Tissue migration and the habitat shared with a complex microbial community pose the question of how the nematode interacts with microbes and host cells from various tissues. This review addresses the current knowledge of the trilateral relationship between Ascaris, its microbial environment, and host cells, and discusses novel approaches targeting these interactions to combat this widespread infection of livestock and man
Infection with soil-transmitted helminths and their impact on coinfections
The most important soil-transmitted helminths (STHs) affecting humans are roundworms, whipworms, and hookworms, with a large proportion of the worldâs population infected with one or more of these intestinal parasites. On top of that, concurrent infections with several viruses, bacteria, protozoa, and other helminths such as trematodes are common in STH-endemic areas. STHs are potent immunomodulators, but knowledge about the effects of STH infection on the direction and extent of coinfections with other pathogens and vice versa is incomplete. By focusing on Kenya, a country where STH infections in humans are widespread, we provide an exemplary overview of the current prevalence of STH and co-occurring infections (e.g. with Human Immunodeficiency Virus, Plasmodium falciparum, Giardia duodenalis and Schistosoma mansoni). Using human data and complemented by experimental studies, we outline the immunomechanistic interactions of coinfections in both acutely STH transmigrated and chronically infected tissues, also highlighting their systemic nature. Depending on the coinfecting pathogen and immunological readout, STH infection may restrain, support, or even override the immune response to another pathogen. Furthermore, the timing of the particular infection and host susceptibility are decisive for the immunopathological consequences. Some examples demonstrated positive outcomes of STH coinfections, where the systemic effects of these helminths mitigate the damage caused by other pathogens. Nevertheless, the data available to date are rather unbalanced, as only a few studies have considered the effects of coinfection on the wormâs life cycle and associated host immunity. These interactions are complex and depend largely on the context and biology of the coinfection, which can act in either direction, both to the benefit and detriment of the infected host
The Intestinal Roundworm Ascaris suum Releases Antimicrobial Factors Which Interfere With Bacterial Growth and Biofilm Formation
Ascariasis is a widespread soil-transmitted helminth infection caused by the intestinal roundworm Ascaris lumbricoides in humans, and the closely related Ascaris suum in pigs. Progress has been made in understanding interactions between helminths and host immune cells, but less is known concerning the interactions of parasitic nematodes and the host microbiota. As the host microbiota represents the direct environment for intestinal helminths and thus a considerable challenge, we studied nematode products, including excretory-secretory products (ESP) and body fluid (BF), of A. suum to determine their antimicrobial activities. Antimicrobial activities against gram-positive and gram-negative bacterial strains were assessed by the radial diffusion assay, while effects on biofilm formation were assessed using the crystal violet static biofilm and macrocolony assays. In addition, bacterial neutralizing activity was studied by an agglutination assay. ESP from different A. suum life stages (in vitro-hatched L3, lung-stage L3, L4, and adult) as well as BF from adult males were analyzed by mass spectrometry. Several proteins and peptides with known and predicted roles in nematode immune defense were detected in ESP and BF samples, including members of A. suum antibacterial factors (ASABF) and cecropin antimicrobial peptide families, glycosyl hydrolase enzymes such as lysozyme, as well as c-type lectin domain-containing proteins. Native, unconcentrated nematode products from intestine-dwelling L4-stage larvae and adults displayed broad-spectrum antibacterial activity. Additionally, adult A. suum ESP interfered with biofilm formation by Escherichia coli, and caused bacterial agglutination. These results indicate that A. suum uses a variety of factors with broad-spectrum antibacterial activity to affirm itself within its microbe-rich environment in the gut
Parasitic Nematodes Exert Antimicrobial Activity and Benefit From Microbiota-Driven Support for Host Immune Regulation
Intestinal parasitic nematodes live in intimate contact with the host microbiota. Changes in the microbiome composition during nematode infection affect immune control of the parasites and shifts in the abundance of bacterial groups have been linked to the immunoregulatory potential of nematodes. Here we asked if the small intestinal parasite Heligmosomoides polygyrus produces factors with antimicrobial activity, senses its microbial environment and if the anti-nematode immune and regulatory responses are altered in mice devoid of gut microbes. We found that H. polygyrus excretory/secretory products exhibited antimicrobial activity against gram+/â bacteria. Parasites from germ-free mice displayed alterations in gene expression, comprising factors with putative antimicrobial functions such as chitinase and lysozyme. Infected germ-free mice developed increased small intestinal Th2 responses coinciding with a reduction in local Foxp3+RORÎłt+ regulatory T cells and decreased parasite fecundity. Our data suggest that nematodes sense their microbial surrounding and have evolved factors that limit the outgrowth of certain microbes. Moreover, the parasites benefit from microbiota-driven immune regulatory circuits, as an increased ratio of intestinal Th2 effector to regulatory T cells coincides with reduced parasite fitness in germ-free mice.Peer Reviewe
Guts within guts: the microbiome of the intestinal helminth parasite Ascaris suum is derived but distinct from its host
Background
Intestinal helminths are extremely prevalent among humans and animals. In particular, intestinal roundworms affect more than 1 billion people around the globe and are a major issue in animal husbandry. These pathogens live in intimate contact with the host gut microbiota and harbor bacteria within their own intestines. Knowledge of the bacterial host microbiome at the site of infection is limited, and data on the parasite microbiome is, to the best of our knowledge, non-existent.
Results
The intestinal microbiome of the natural parasite and zoonotic macropathogen, Ascaris suum was analyzed in contrast to the diversity and composition of the infected host gut. 16S sequencing of the parasite intestine and host intestinal compartments showed that the parasite gut has a significantly less diverse microbiome than its host, and the host gut exhibits a reduced microbiome diversity at the site of parasite infection in the jejunum. While the hostâs microbiome composition at the site of infection significantly determines the microbiome composition of its parasite, microbial signatures differentiate the nematodes from their hosts as the Ascaris intestine supports the growth of microbes that are otherwise under-represented in the host gut.
Conclusion
Our data clearly indicate that a nematode infection reduces the microbiome diversity of the host gut, and that the nematode gut represents a selective bacterial niche harboring bacteria that are derived but distinct from the host gut