32 research outputs found
Fecal Microbiota Transplant From Highly Feed Efficient Donors Affects Cecal Physiology and Microbiota in Low- and High-Feed Efficient Chickens
Publication history: Accepted - 25 June 2019; Published online - 9 July 2019Fecal microbiota transplants (FMT) may be used to improve chicken’s feed efficiency
(FE) via modulation of the intestinal microbiota and microbe-host signaling. This study
investigated the effect of the administration of FMT from highly feed efficient donors early
in life on the jejunal and cecal microbiota, visceral organ size, intestinal morphology,
permeability, and expression of genes for nutrient transporters, barrier function and
innate immune response in chickens of diverging residual feed intake (RFI; a metric
for FE). Chicks (n = 110) were inoculated with the FMT or control transplant (CT) on
1, 6, and 9 days posthatch (dph), from which 56 chickens were selected on 30 dph
as the extremes in RFI, resulting in 15 low and 13 high RFI chickens receiving the
FMT and 14 low and 14 high RFI chickens receiving the CT. RFI rank and FMT only
caused tendencies for alterations in the jejunal microbiota and only one unclassified
Lachnospiraceae genus in cecal digesta was indicative of high RFI. By contrast, the
FMT caused clear differences in the short-chain fatty acid (SCFA) profile in the crop
and cecal microbiota composition compared to the CT, which indicated alterations
in amylolytic, pullulanolytic and hemicellulolytic bacteria such as Lactobacillus, Dorea,
and Ruminococcus. Moreover, the FMT caused alterations in intestinal development
as indicated by the longer duodenum and shallower crypts in the ceca. From the
observed RFI-associated variation, energy-saving mechanisms and moderation of the
mucosal immune response were indicated by higher jejunal permeability, shorter villi
in the ileum, and enhanced cecal expression of the anti-inflammatory cytokine IL10 in
low RFI chickens. Relationships obtained from supervised multigroup data integration
support that certain bacteria, including Ruminococcocaceae-, Lactobacillus-, and
unclassified Clostridiales-phylotypes, and SCFA in jejunal and cecal digesta modulated
expression levels of cytokines, tight-junction protein OCLN and nutrient transporters
for glucose and SCFA uptake. In conclusion, results suggest that the intestine only
Frontiers in Microbiology | www.frontiersin.org 1 July 2019 | Volume 10 | Article 1576
fmicb-10-01576 July 5, 2019 Time: 15:15 # 2
Metzler-Zebeli et al. Fecal Microbiota Transplant and Gut Functions
played a moderate role for the RFI-associated variation of the present low and high
RFI phenotypes, whereas modulating the early microbial colonization resulted in longlasting changes in bacterial taxonomic and metabolite composition as well as in host
intestinal development.This project (ECO-FCE) has received funding from the European Union’s Seventh Framework Programme for research, technological development, and demonstration under Grant Agreement No. 311794
Feed Restriction Reveals Distinct Serum Metabolome Profiles in Chickens Divergent in Feed Efficiency Traits
Publication history: Accepted - 20 February 2019; Published - 25 February 2019.Restrictive feeding influences systemic metabolism of nutrients; however, this impact
has not been evaluated in chickens of diverging feed efficiency. This study investigated the effect
of ad libitum versus restrictive feeding (85% of ad libitum) on the serum metabolome and white
blood cell composition in chickens of diverging residual feed intake (RFI; metric for feed efficiency).
Blood samples were collected between days 33 and 37 post-hatch. While serum glucose was
similar, serum uric acid and cholesterol were indicative of the nutritional status and chicken’s
RFI, respectively. Feed restriction and RFI rank caused distinct serum metabolome profiles, whereby
restrictive feeding also increased the blood lymphocyte proportion. Most importantly, 10 amino
acids were associated with RFI rank in birds, whereas restrictive feeding affected almost all detected
lysophosphatidylcholines, with 3 being higher and 6 being lower in restrictively compared to ad
libitum fed chickens. As indicated by relevance networking, isoleucine, lysine, valine, histidine, and
ornithine were the most discriminant for high RFI, whereas 3 biogenic amines (carnosine, putrescine,
and spermidine) and 3 diacyl-glycerophospholipids (38:4, 38:5, and 40:5) positively correlated with
feed intake and body weight gain, respectively. Only for taurine, feed intake mostly explained
the RFI-associated variation, whereas for most metabolites, other host physiological factors played
a greater role for the RFI-associated differences, and was potentially related to insulin-signaling,
phospholipase A2, and arachidonic acid metabolism. Alterations in the hepatic synthesis of long-chain
fatty acids and the need for precursors for gluconeogenesis due to varying energy demand may
explain the marked differences in serum metabolite profiles in ad libitum and restrictively fed birds.This project (ECO-FCE) has received funding from the European Union’s Seventh Framework
Programme for research, technological development, and demonstration under grant agreement no. 311794
Feed Restriction Modulates the Fecal Microbiota Composition, Nutrient Retention, and Feed Efficiency in Chickens Divergent in Residual Feed Intake
Publication histroy: Accepted - 23 October 2018; Published - 19 November 2019.There is a great interest to understand the impact of the gut microbiota on host’s
nutrient use and FE in chicken production. Both chicken’s feed intake and gut bacterial
microbiota differ between high and low-feed efficient chickens. To evaluate the impact
of the feed intake level on the feed efficiency (FE)-associated variation in the chicken
intestinal microbiota, differently feed efficient chickens need to eat the same amount of
feed, which can be achieved by feeding chickens restrictively. Therefore, we investigated
the effect of restrictive vs. ad libitum feeding on the fecal microbiome at 16 and 29
days posthatch (dph), FE and nutrient retention in chickens of low and high residual
feed intake (RFI; metric for FE). Restrictively fed chickens were provided the same
amount of feed which corresponded to 85% of the ad libitum fed group from 9 dph.
FE was determined for the period between 9 and 30 dph and feces for nutrient retention
were collected on 31 to 32 dph. From the 112 chickens (n = 56 fed ad libitum, and
n = 56 fed restrictively), 14 low RFI and 15 high RFI ad libitum fed chickens, and
14 low RFI (n = 7 per sex) and 14 high RFI restrictively fed chickens were selected
as the extremes in RFI and were retrospectively chosen for data analysis. Bray-Curtis
dissimilarity matrices showed significant separation between time points, and feeding
level groups at 29 dph for the fecal bacterial communities. Relevance networking
indicated positive associations between Acinetobacter and feed intake at 16 dph,
whereas at 29 dph Escherichia/Shigella and Turicibacter positively and Lactobacillus
negatively correlated to chicken’s feed intake. Enterobacteriaceae was indicative for
low RFI at 16 dph, whereas Acinetobacter was linked to high RFI across time points.
However, restrictive feeding-associated changes in the fecal microbiota were not similar
in low and high RFI chickens, whichmay have been related to the higher nutrient retention
and thus lower fecal nutrient availability in restrictively fed high RFI chickens. Thismay also
explain the decreased RFI value in restrictively fed high RFI chickens indicating improved
FE, with a stronger effect in females.This project (ECO-FCE) has received funding from the
European Union’s Seventh Framework Programme for research,
technological development and demonstration under grant
agreement No. 311794
Fecal Microbiota Transplant from Highly Feed-Efficient Donors Shows Little Effect on Age-Related Changes in Feed-Efficiency-Associated Fecal Microbiota from Chickens
peer-reviewedChickens with good or poor feed efficiency (FE) have been shown to
differ in their intestinal microbiota composition. This study investigated differences
in the fecal bacterial community of highly and poorly feed-efficient chickens at 16
and 29 days posthatch (dph) and evaluated whether a fecal microbiota transplant
(FMT) from feed-efficient donors early in life can affect the fecal microbiota in chickens at 16 and 29 dph and chicken FE and nutrient retention at 4 weeks of age. A
total of 110 chickens were inoculated with a FMT or a control transplant (CT) on
dph 1, 6, and 9 and ranked according to residual feed intake (RFI; the metric for FE)
on 30 dph. Fifty-six chickens across both inoculation groups were selected as the extremes in RFI (29 low, 27 high). RFI-related fecal bacterial profiles were discernible at
16 and 29 dph. In particular, Lactobacillus salivarius, Lactobacillus crispatus, and Anaerobacterium operational taxonomic units were associated with low RFI (good FE).
Multiple administrations of the FMT only slightly changed the fecal bacterial composition, which was supported by weighted UniFrac analysis, showing similar bacterial
communities in the feces of both inoculation groups at 16 and 29 dph. Moreover,
the FMT did not change the RFI and nutrient retention of highly and poorly feedefficient recipients, whereas it tended to increase feed intake and body weight gain
in female chickens. This finding suggests that host- and environment-related factors
may more strongly affect chicken fecal microbiota and FE than the FMT.European Union Seventh Framework Programm
Feed Restriction Modifies Intestinal Microbiota-Host Mucosal Networking in Chickens Divergent in Residual Feed Intake
Publication history: Accepted online - 8 January 2019; Published online - 29 January 2019.Differences in chickens’ feed intake may be the underlying factor influencing
feed-efficiency (FE)-associated variation in intestinal microbiota and physiology.
In chickens eating the same amount of feed, quantitative feed restriction may
create similar intestinal conditions and help clarify this cause-and-effect relationship.
This study investigated the effect of ad libitum versus restrictive feeding (85% of ad
libitum) on ileal and cecal microbiota, concentrations of short-chain fatty acids, visceral
organ size, intestinal morphology, permeability, and expression of genes related
to nutrient uptake, barrier function, and innate immune response in broiler
chickens with divergent residual feed intake (RFI; metric for FE). On day 30 posthatch,
28 low-RFI (good FE) and 29 high-RFI (poor FE) chickens across both feedinglevel
groups (n 112) were selected. Supervised multigroup data integration and
relevance network analyses showed that especially Lactobacillus (negative) in ileal digesta,
Turicibacter (positive) in cecal digesta, and Enterobacteriaceae (positive) in
both intestinal segments depended on chicken’s feed intake, whereas the level of
Anaerotruncus in cecal digesta was most discriminative for high RFI. Moreover, shallower
crypts and fewer goblet cells in ceca indicated host-related energy-saving
mechanisms with low RFI, whereas greater tissue resistance suggested a stronger jejunal
barrier function in low-RFI chickens. Values corresponding to feed intake
level RFI interactions indicated larger pancreas and lower levels of ileal and cecal
short-chain fatty acids in restrictively fed high-RFI chickens than in the other 3
groups, suggesting host physiological adaptations to support greater energy and
nutrient needs of high-RFI chickens compensating for the restricted feeding.
IMPORTANCE The impact of the FE-associated differences in feed intake on intestinal
bacterial and host physiological parameters has so far not been clarified. Understanding
the underlying principles is essential for the development of cost-effective
strategies to improve FE in chicken production. Under conditions of quantitative
feed restriction, low- and high-RFI chickens ate the same amount of feed. Therefore,
this research helps in distinguishing intestinal bacterial taxa and functions that were
highly reliant on feed intake from those that were associated with physiological adaptations
to RFI-associated differences in host nutritional needs and intestinal nutrient
availability. This work provides a background for further research to assess manipulation
of the intestinal microbiota, host physiology, and FE in chickens by
dietary intervention.This project (ECO-FCE) has received funding from the European Union’s Seventh
Framework Program for research, technological development, and demonstration under
grant agreement 311794
Comparison of proteomic responses as global approach to antibiotic mechanism of action elucidation
This is an open-access article distributed under the terms of the Creative Commons Attribution 4.0 International license. New antibiotics are urgently needed to address the mounting resistance challenge. In early drug discovery, one of the bottlenecks is the elucidation of targets and mechanisms. To accelerate antibiotic research, we provide a proteomic approach for the rapid classification of compounds into those with precedented and unprecedented modes of action. We established a proteomic response library of Bacillus subtilis covering 91 antibiotics and comparator compounds, and a mathematical approach was developed to aid data analysis. Comparison of proteomic responses (CoPR) allows the rapid identification of antibiotics with dual mechanisms of action as shown for atypical tetracyclines. It also aids in generating hypotheses on mechanisms of action as presented for salvarsan (arsphenamine) and the antirheumatic agent auranofin, which is under consideration for repurposing. Proteomic profiling also provides insights into the impact of antibiotics on bacterial physiology through analysis of marker proteins indicative of the impairment of cellular processes and structures. As demonstrated for trans-translation, a promising target not yet exploited clinically, proteomic profiling supports chemical biology approaches to investigating bacterial physiology
IST Austria Thesis
Social insects are a common model to study disease dynamics in social animals. Even though pathogens should thrive in social insect colonies as the hosts engage in frequent social interactions, are closely related and live in a pathogen-rich environment, disease outbreaks are rare. This is because social insects have evolved mechanisms to keep pathogens at bay – and fight disease as a collective. Social insect colonies are often viewed as “superorganisms” with division of labor between reproductive “germ-like” queens and males and “somatic” workers, which together form an interdependent reproductive unit that parallels a multicellular body. Superorganisms possess a “social immune system” that comprises of collective disease defenses performed by the workers - summarized as “social immunity”. In social groups immunization (reduced susceptibility to a parasite upon secondary exposure to the same parasite) can e.g. be triggered by social interactions (“social immunization”). Social immunization can be caused by (i) asymptomatic low-level infections that are acquired during caregiving to a contagious individual that can give an immune boost, which can induce protection upon later encounter with the same pathogen (active immunization) or (ii) by transfer of immune effectors between individuals (passive immunization).
In the second chapter, I built up on a study that I co-authored that found that low-level infections can not only be protective, but also be costly and make the host more susceptible to detrimental superinfections after contact to a very dissimilar pathogen. I here now tested different degrees of phylogenetically-distant fungal strains of M. brunneum and M. robertsii in L. neglectus and can describe the occurrence of cross-protection of social immunization if the first and second pathogen are from the same level. Interestingly, low-level infections only provided protection when the first strain was less virulent than the second strain and elicited higher immune gene expression.
In the third and fourth chapters, I expanded on the role of social immunity in sexual selection, a so far unstudied field. I used the fungus Metarhizium robertsii and the ant Cardiocondyla obscurior as a model, as in this species mating occurs in the presence of workers and can be studied under laboratory conditions. Before males mate with virgin queens in the nest they engage in fierce combat over the access to their mating partners.
First, I focused on male-male competition in the third chapter and found that fighting with a contagious male is costly as it can lead to contamination of the rival, but that workers can decrease the risk of disease contraction by performing sanitary care.
In the fourth chapter, I studied the effect of fungal infection on survival and mating success of sexuals (freshly emerged queens and males) and found that worker-performed sanitary care can buffer the negative effect that a pathogenic contagion would have on sexuals by spore removal from the exposed individuals. When social immunity was prevented and queens could contract spores from their mating partner, very low dosages led to negative consequences: their lifespan was reduced and they produced fewer offspring with poor immunocompetence compared to healthy queens. Interestingly, cohabitation with a late-stage infected male where no spore transfer was possible had a positive effect on offspring immunity – male offspring of mothers that apparently perceived an infected partner in their vicinity reacted more sensitively to fungal challenge than male offspring without paternal pathogen history
Individual- and ejaculate-specific sperm traits in ant males
Sperm cells are the most morphologically diverse cells across animal taxa. Within species, sperm and ejaculate traits have been suggested to vary with the male's competitive environment, e.g., level of sperm competition, female mating status and quality, and also with male age, body mass, physiological condition, and resource availability. Most previous studies have based their conclusions on the analysis of only one or a few ejaculates per male without investigating differences among the ejaculates of the same individual. This masks potential ejaculate-specific traits. Here, we provide data on the length, quantity, and viability of sperm ejaculated by wingless males of the ant Cardiocondyla obscurior. Males of this ant species are relatively long-lived and can mate with large numbers of female sexuals throughout their lives. We analyzed all ejaculates across the individuals' lifespan and manipulated the availability of mating partners. Our study shows that both the number and size of sperm cells transferred during copulations differ among individuals and also among ejaculates of the same male. Sperm quality does not decrease with male age, but the variation in sperm number between ejaculates indicates that males need considerable time to replenish their sperm supplies. Producing many ejaculates in a short time appears to be traded-off against male longevity rather than sperm quality
Protection against the lethal side effects of social immunity in ants
Many animals use antimicrobials to prevent or cure disease [1,2]. For example, some animals will ingest plants with medicinal properties, both prophylactically to prevent infection and therapeutically to self-medicate when sick. Antimicrobial substances are also used as topical disinfectants, to prevent infection, protect offspring and to sanitise their surroundings [1,2]. Social insects (ants, bees, wasps and termites) build nests in environments with a high abundance and diversity of pathogenic microorganisms — such as soil and rotting wood — and colonies are often densely crowded, creating conditions that favour disease outbreaks. Consequently, social insects have evolved collective disease defences to protect their colonies from epidemics. These traits can be seen as functionally analogous to the immune system of individual organisms [3,4]. This ‘social immunity’ utilises antimicrobials to prevent and eradicate infections, and to keep the brood and nest clean. However, these antimicrobial compounds can be harmful to the insects themselves, and it is unknown how colonies prevent collateral damage when using them. Here, we demonstrate that antimicrobial acids, produced by workers to disinfect the colony, are harmful to the delicate pupal brood stage, but that the pupae are protected from the acids by the presence of a silk cocoon. Garden ants spray their nests with an antimicrobial poison to sanitize contaminated nestmates and brood. Here, Pull et al show that they also prophylactically sanitise their colonies, and that the silk cocoon serves as a barrier to protect developing pupae, thus preventing collateral damage during nest sanitation
Trade-offs between immunity and competitive ability in fighting ant males
Background: Fighting disease while fighting rivals exposes males to constraints and tradeoffs during male-male competition. We here tested how both the stage and intensity of infection with the fungal pathogen Metarhizium robertsii interfered with fighting success in Cardiocondyla obscurior ant males. Males of this species have evolved long lifespans during which they can gain many matings with the young queens of the colony, if successful in male-male competition. Since male fights occur inside the colony, the outcome of male-male competition can further be biased by interference of the colony’s worker force.
Results: We found that severe, but not yet mild, infection strongly impaired male fighting success. In late-stage infection, this could be attributed to worker aggression directed towards the infected rather than the healthy male and an already very high male morbidity even in the absence of fighting. Shortly after pathogen exposure, however, male mortality was particularly increased during combat. Since these males mounted a strong immune response, their reduced fighting success suggests a trade-off between immune investment and competitive ability already early in the infection. Even if the males themselves showed no difference in the number of attacks they raised against their healthy rivals across infection stages and levels, severely infected males were thus losing in male-male competition from an early stage of infection on.
Conclusions: Males of the ant C. obscurior have evolved high immune investment, triggering an effective immune response very fast after fungal exposure. This allows them to cope with mild pathogen exposures without cost to their success in male-male competition, and hence to gain multiple mating opportunities with the emerging virgin queens of the colony. Under severe infection, however, they are weak fighters and rarely survive a combat already at early infection when raising an immune response, as well as at progressed infection, when they are morbid and preferentially targeted by worker aggression. Workers thereby remove males that pose a future disease threat by biasing male-male competition. Our study thus revealed a novel social immunity mechanism how social insect workers protect the colony against disease risk