scholarly journals Analysis of Bacterial Diversity in Relation to the Presence of the Top 7 Shiga Toxin–Producing Escherichia coli throughout Australian Beef Abattoirs

2020 ◽  
Vol 83 (10) ◽  
pp. 1812-1821
Author(s):  
SANGA KANG ◽  
JOSHUA T. RAVENSDALE ◽  
RANIL COOREY ◽  
GARY A. DYKES ◽  
ROBERT S. BARLOW

ABSTRACT There is increasing evidence that diversity changes in bacterial communities of beef cattle correlate to the presence of Shiga toxin–producing Escherichia coli (STEC). However, studies that found an association between STEC and bacterial diversity have been focused on preslaughter stages in the beef supply chain. This study was designed to test a hypothesis that there are no differences in bacterial diversity between samples with and those without the presence of the top 7 STEC (O26, O45, O103, O111, O121, O145, and O157) throughout processing in an integrated (abattoir A) and a fragmented (abattoir B) Australian beef abattoir. Slaughter and boning room surface samples from each abattoir were analyzed using 16S rRNA amplicon sequencing and tested for the top 7 STEC following the Food Safety and Inspection Service protocol. Potential positives through slaughter were similar between the abattoirs (64 to 81%). However, abattoir B had substantially reduced potential positives in the boning room compared with abattoir A (abattoir A: 23 and 48%; abattoir B: 2 and 7%). Alpha diversity between the sample groups was not significantly different (P > 0.05) regardless of different STEC markers. Nonmetric multidimensional scaling of slaughter samples showed that the bacterial composition in fecal and hide samples shared the least similarity with the communities in carcass and environmental samples. Surface samples from slaughter (carcass and environmental) and boning (carcass, beef trim, and environmental) all appeared randomly plotted on the scale. This indicated that the STEC presence also did not have a significant effect (P > 0.05) on beta diversity. Although presence of STEC appeared to correlate with changes in diversity of fecal and hide bacterial communities in previous studies, it did not appear to have the same effect on other samples throughout processing. HIGHLIGHTS

Diversity ◽  
2021 ◽  
Vol 13 (2) ◽  
pp. 85
Author(s):  
Allison M. Spring ◽  
Kenneth D. Domingue ◽  
Thomas V. Kerber ◽  
Margaret M. Mooney ◽  
Rebecca L. Hale ◽  
...  

Land use influences the composition of near-surface airborne bacterial communities, and bacteria can be transported through the atmosphere at global scales. The atmosphere mixes vertically, but rigorously assessing whether the effects of land use on atmospheric communities extends to higher altitudes requires examining communities from multiple altitudes collected at a stable location and timeframe. In this study, we collected near-surface (<2 m) and higher-altitude (150 m) air samples from three sites in an agricultural/developed location and a forested/undeveloped location. We used bacterial 16S rRNA amplicon sequencing to compare communities and predict functionality by altitude. Higher-altitude and near-surface communities did not differ in composition within each location. Communities collected above the undeveloped location were equally variable at both altitudes; higher-altitude samples from the developed location predominantly contained Firmicutes and were less variable than near-surface samples. We also compared airborne taxa to those present in soil and snow. Communities from higher-altitude samples above the developed location contained fewer overlapping taxa with soil and snow sources, and overlapping Operational Taxonomic Units (OTUs) among the three sources differed by location. Our results suggest that land use affects the composition of both near-surface and higher-altitude airborne bacterial communities and, therefore, may influence broad bacterial dispersal patterns. This small-scale pilot study provides a framework for simultaneously examining local and regional airborne microbial communities that can be applied to larger studies or studies using different types of samplers.


Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2414
Author(s):  
Laura Sanjulián ◽  
Alexandre Lamas ◽  
Rocío Barreiro ◽  
Alberto Cepeda ◽  
Cristina A. Fente ◽  
...  

The objective of this work was to characterize the microbiota of breast milk in healthy Spanish mothers and to investigate the effects of lactation time on its diversity. A total of ninety-nine human milk samples were collected from healthy Spanish women and were assessed by means of next-generation sequencing of 16S rRNA amplicons and by qPCR. Firmicutes was the most abundant phylum, followed by Bacteroidetes, Actinobacteria, and Proteobacteria. Accordingly, Streptococcus was the most abundant genus. Lactation time showed a strong influence in milk microbiota, positively correlating with Actinobacteria and Bacteroidetes, while Firmicutes was relatively constant over lactation. 16S rRNA amplicon sequencing showed that the highest alpha-diversity was found in samples of prolonged lactation, along with wider differences between individuals. As for milk nutrients, calcium, magnesium, and selenium levels were potentially associated with Streptococcus and Staphylococcus abundance. Additionally, Proteobacteria was positively correlated with docosahexaenoic acid (DHA) levels in breast milk, and Staphylococcus with conjugated linoleic acid. Conversely, Streptococcus and trans-palmitoleic acid showed a negative association. Other factors such as maternal body mass index or diet also showed an influence on the structure of these microbial communities. Overall, human milk in Spanish mothers appeared to be a complex niche shaped by host factors and by its own nutrients, increasing in diversity over time.


2020 ◽  
Author(s):  
Pedro E. Romero ◽  
Erika Calla-Quispe ◽  
Camila Castillo-Vilcahuaman ◽  
Mateo Yokoo ◽  
Hammerly Lino Fuentes-Rivera ◽  
...  

AbstractBackgroundThe Rimac river is the main source of water for Lima, Peru’s capital megacity. The river is constantly affected by different types of contamination including mine tailings in the Andes and urban sewage in the metropolitan area. We aim to produce the first characterization of bacterial communities in the Rimac river using a 16S rRNA amplicon sequencing approach which would be useful to identify bacterial diversity and potential understudied pathogens.ResultsWe report a higher diversity in bacterial communities from the Upper and, especially, Middle Rimac compared to the Lower Rimac (Metropolitan zone). Samples were generally grouped according to their geographical location. Bacterial classes Alphaproteobacteria, Bacteroidia, Campylobacteria, Fusobacteriia, and Gammaproteobacteria were the most frequent along the river. Arcobacter cryaerophilus (Campylobacteria) was the most frequent species in the Lower Rimac while Flavobacterium succinicans (Bacteroidia) and Hypnocyclicus (Fusobacteriia) were the most predominant in the Upper Rimac. Predicted metabolic functions in the microbiota include bacterial motility, quorum sensing and xenobiotics metabolism. Additional metabolomic analyses showed the presence natural flavonoids and antibiotics in the Upper Rimac, and herbicides in the Lower Rimac.ConclusionsThe dominance in the Metropolitan area of Arcobacter cryaerophilus, an emergent pathogen associated with fecal contamination and antibiotic multiresistance, but that is not usually reported in traditional microbiological quality assessments, highlights the necessity to apply next-generation sequencing tools to improve pathogen surveillance. We believe that our study will encourage the integration of omics sciences in Peru and its application on current environmental and public health issues.


2020 ◽  
Vol 7 (6) ◽  
pp. e896
Author(s):  
Alexandre Lecomte ◽  
Lucie Barateau ◽  
Pedro Pereira ◽  
Lars Paulin ◽  
Petri Auvinen ◽  
...  

ObjectiveTo test the hypothesis that narcolepsy type 1 (NT1) is related to the gut microbiota, we compared the microbiota bacterial communities of patients with NT1 and control subjects.MethodsThirty-five patients with NT1 (51.43% women, mean age 38.29 ± 19.98 years) and 41 controls (57.14% women, mean age 36.14 ± 12.68 years) were included. Stool samples were collected, and the fecal microbiota bacterial communities were compared between patients and controls using the well-standardized 16S rRNA gene amplicon sequencing approach. We studied alpha and beta diversity and differential abundance analysis between patients and controls, and between subgroups of patients with NT1.ResultsWe found no between-group differences for alpha diversity, but we discovered in NT1 a link with NT1 disease duration. We highlighted differences in the global bacterial community structure as assessed by beta diversity metrics even after adjustments for potential confounders as body mass index (BMI), often increased in NT1. Our results revealed differential abundance of several operational taxonomic units within Bacteroidetes, Bacteroides, and Flavonifractor between patients and controls, but not after adjusting for BMI.ConclusionWe provide evidence of gut microbial community structure alterations in NT1. However, further larger and longitudinal multiomics studies are required to replicate and elucidate the relationship between the gut microbiota, immunity dysregulation and NT1.


Rheumatology ◽  
2020 ◽  
Author(s):  
Maxim B Freidin ◽  
Maria A Stalteri ◽  
Philippa M Wells ◽  
Genevieve Lachance ◽  
Andrei-Florin Baleanu ◽  
...  

Abstract Objectives Chronic widespread musculoskeletal pain (CWP) is a characteristic symptom of fibromyalgia, which has been shown to be associated with an altered gut microbiome. Microbiome studies to date have not examined the milder CWP phenotype specifically nor have they explored the role of raised BMI. The aim of this study was to investigate whether the microbiome is abnormal in CWP. Methods CWP was assessed using a standardized screening questionnaire in female volunteers from the TwinsUK cohort including 113 CWP cases and 1623 controls. The stool microbiome was characterised using 16S rRNA amplicon sequencing and amplicon sequence variants (ASVs), and associations with CWP examined using linear mixed-effects models adjusting for BMI, age, diet, family relatedness and technical factors. Results Alpha diversity was significantly lower in CWP cases than controls (Mann–Whitney test, p-values 2.3e-04 and 1.2e-02, respectively). The species Coprococcus comes was significantly depleted in CWP cases (p.adj = 3.04e-03). A genome-wide association study (GWAS) performed for C. comes in TwinsUK followed by meta-analysis with three Dutch cohorts (total n = 3521) resulted in nine suggestive regions, with the most convincing on chromosome 4 near the TRAM1L1 gene (rs76957229, p= 7.4e-8). A Mendelian randomisation study based on the results of the GWAS did not support a causal role for C. comes on the development of CWP. Conclusions We have demonstrated reduced diversity in the microbiome in CWP, indicating an involvement of the gut microbiota in CWP; prospectively the microbiome may offer therapeutic opportunities for this condition.


2017 ◽  
Vol 4 (4) ◽  
pp. 170107 ◽  
Author(s):  
Molly C. Bletz ◽  
R. G. Bina Perl ◽  
Miguel Vences

Diverse microbial assemblages inhabit amphibian skin and are known to differ among species; however, few studies have analysed these differences in systems that minimize confounding factors, such as season, location or host ecology. We used high-throughput amplicon sequencing to compare cutaneous microbiotas among two ranid frogs ( Rana dalmatina, R. temporaria ) and four salamandrid newts ( Ichthyosaura alpestris, Lissotriton helveticus, L. vulgaris, Triturus cristatus ) breeding simultaneously in two ponds near Braunschweig, Germany. We found that bacterial communities differed strongly and consistently between these two distinct amphibian clades. While frogs and newts had similar cutaneous bacterial richness, their bacterial composition strongly differed. Average Jaccard distances between frogs and newts were over 0.5, while between species within these groups distances were only 0.387 and 0.407 for frogs and newts, respectively. At the operational taxonomic unit (OTU) level, 31 taxa exhibited significantly different relative abundances between frogs and newts. This finding suggests that chemical or physical characteristics of these amphibians' mucosal environments provide highly selective conditions for bacterial colonizers. Multi-omics analyses of hosts and their microbiota as well as directed efforts to understand chemical differences in the mucosal environments (e.g. pH), and the specificities of host-produced compounds against potential colonizers will help to better understand this intriguing pattern.


2014 ◽  
Vol 77 (7) ◽  
pp. 1052-1061 ◽  
Author(s):  
ABEL B. EKIRI ◽  
DOUGLAS LANDBLOM ◽  
DAWN DOETKOTT ◽  
SUSAN OLET ◽  
WEILIN L. SHELVER ◽  
...  

Cattle are the main reservoirs for Shiga toxin–producing Escherichia coli (STEC) strains. E. coli O26, O45, O103, O111, O121, O145, and O157 are among the STEC serogroups that cause severe foodborne illness and have been declared as adulterants by the U.S. Department of Agriculture, Food Safety and Inspection Service. The objectives of this study were (i) to estimate the prevalence of non-O157 STEC and E. coli O157 in naturally infected beef cows and in steer calves at postweaning, during finishing, and at slaughter and (ii) to test non-O157 STEC isolates for the presence of virulence genes stx1, stx2, eaeA, and ehlyA. Samples were collected from study animals during multiple sampling periods and included fecal grabs, rectal swabs, and midline sponge samples. Laboratory culture, PCR, and multiplex PCR were performed to recover and identify E. coli and the virulence genes. The prevalence of non-O157 STEC (serogroups O26, O45, O103, O111, O121, O113, and O145) fecal shedding ranged from 8% (4 of 48 samples) to 39% (15 of 38 samples) in cows and 2% (1 of 47 samples) to 38% (9 of 24 samples) in steer calves. The prevalence of E. coli O157 fecal shedding ranged from 0% (0 of 38 samples) to 52% (25 of 48 samples) in cows and 2% (1 of 47 samples) to 31% (15 of 48 samples) in steer calves. In steer calves, the prevalence of non-O157 STEC and E. coli O157 was highest at postweaning, at 16% (15 of 96 samples) and 23% (22 of 96 samples), respectively. Among the 208 non-O157 STEC isolates, 79% (164 isolates) had stx1, 79% (165 isolates) had stx2, and 58% (121 isolates) had both stx1 and stx2 genes. The percentage of non-O157 STEC isolates encoding the eaeA gene was low; of the 165 isolates tested, 8 (5%) were positive for eaeA and 135 (82%) were positive for ehlyA. Findings from this study provide further evidence of non-O157 STEC shedding in beef cows and steer calves particularly at the stage of postweaning and before entry into the feedlot.


2021 ◽  
Author(s):  
Nicole E Adams ◽  
Madeleine A Becker ◽  
Suzanne Edmands

Abstract Background With developing understanding that host-associated microbiota play significant roles in individual health and fitness, taking an interdisciplinary approach combining microbiome research with conservation science is increasingly favored. Here we establish the scat microbiome of the imperiled Channel Island fox (Urocyon littoralis) and look at the effects of geography and captivity on the variation in bacterial communities. Results Using high throughput 16S rRNA gene amplicon sequencing, we discovered distinct bacterial communities in each island fox subspecies. Weight, timing of the sample collection, and sex contributed to the geographic patterns. We uncovered significant taxonomic differences and an overall decrease in bacterial diversity in captive versus wild foxes. Conclusions Understanding the drivers of microbial variation in this system provides a valuable lens through which to evaluate the health and conservation of these genetically depauperate foxes. The island-specific bacterial community baselines established in this study can make monitoring island fox health easier and understanding the implications of inter-island translocation clearer. The decrease in bacterial diversity within captive foxes could lead to losses in the functional services normally provided by commensal microbes and suggests that zoos and captive breeding programs would benefit from maintaining microbial diversity.


2020 ◽  
Author(s):  
Katelyn Mika ◽  
Alexander S. Okamoto ◽  
Neil H. Shubin ◽  
David B. Mark Welch

AbstractMicrobial transmission from parent to offspring is hypothesized to be universal in vertebrates. However, evidence for this is limited as many clades remain unexamined. Chondrichthyes, as one of the earliest–branching vertebrate lineages, provide an opportunity to investigate the phylogenetic breadth of this hypothesis. To assess the potential for bacterial transmission in an oviparous chondrichthyan, we used 16S rRNA amplicon sequencing to characterize the microbial communities associated with the skin, gill, and egg capsule of the little skate, Leucoraja erinacea, at six points during ontogeny. We identify site-specific microbiomes dominated by the bacterial phyla Proteobacteria and Bacteroidetes, a composition similar to, but distinct from, that of other chondrichthyans. Our data reveal that the skate egg capsule harbors a highly diverse bacterial community–particularly on the internal surface of the capsule–and facilitates intergenerational microbial transfer to the offspring. Embryonic skin and external gill tissues host similar bacterial communities; the skin and gill communities later diverge as the internal gills and skin denticles develop. Our study is the first exploration of the chondrichthyan microbiome throughout ontogeny and provides the first evidence of vertical transmission in this group, which may be the primary mechanism for the signature of phylosymbiosis previously observed in elasmobranchs.


Author(s):  
Peter J. Flynn ◽  
Catherine L. D’Amelio ◽  
Jon G. Sanders ◽  
Jacob A. Russell ◽  
Corrie S. Moreau

Microbial communities within the animal digestive tract often provide important functions for their hosts. The composition of eukaryotes' gut bacteria can be shaped by host diet, vertical bacterial transmission, and physiological variation within the digestive tract. In several ant taxa, recent findings have demonstrated that nitrogen provisioning by symbiotic bacteria makes up for deficiencies in herbivorous diets. Using 16S rRNA amplicon sequencing and qPCR, this study examined bacterial communities at a fine scale across one such animal group, the turtle ant genus Cephalotes. We analyzed the composition and colonization density across four portions of the digestive tract to understand how bacterial diversity is structured across gut compartments, potentially allowing for specific metabolic functions of benefit to the host. In addition, we aimed to understand if caste differentiation or host relatedness influences the gut bacterial communities of Cephalotes ants. Microbial communities were found to vary strongly across Cephalotes gut compartments in ways that transcend both caste and host phylogeny. Despite this, caste and host phylogeny still have detectable effects. We demonstrated microbial community divergence across gut compartments, possibly due to the varying function of each gut compartment for digestion. IMPORTANCE Gut compartments play an important role in structuring the microbial community within individual ants. The gut chambers of the turtle ant digestive tract differ remarkably in symbiont abundance and diversity. Furthermore, caste type explains some variation in the microbiome composition. Finally, the evolutionary history of the Cephalotes species structures the microbiome in our study, which elucidates a trend in which related ants maintain related microbiomes, conceivably owing to co-speciation. Amazingly, gut compartment-specific signatures of microbial diversity, relative abundance, composition, and abundance have been conserved over Cephalotes evolutionary history, signifying that this symbiosis has been largely stable for over 50 million years.


Sign in / Sign up

Export Citation Format

Share Document