Spore samplers are widely used in pathogen surveillance but not so much for monitoring the composition of aeromycobiota. In Canada, a nationwide spore-sampling network (AeroNet) was established as a ...pilot project to assess fungal community composition in air and rain samples collected using three different spore samplers in the summers of 2010 and 2011. Metabarcodes of the internal transcribed spacer (ITS) were exhaustively characterized for three of the network sites, in British Columbia (BC), Québec (QC), and Prince Edward Island (PEI), to compare performance of the samplers. Sampler type accounted for ca. 20% of the total explainable variance in aeromycobiota compositional heterogeneity, with air samplers recovering more Ascomycota and rain samplers recovering more Basidiomycota. Spore samplers showed different abilities to collect 27 fungal genera that are plant pathogens. For instance,
spp.,
spp., and
spp. were collected mainly by air samplers, while
spp.,
spp., and
spp. were recovered more frequently with rain samplers. The diversity and abundance of some fungi were significantly affected by sampling location and time (e.g.,
and
) and weather conditions (e.g.,
and
), and depended on using ITS1 or ITS2 as the barcoding region (e.g.,
and
). The observation that Canada's aeromycobiota diversity correlates with cooler, wetter conditions and northward wind requires support from more long-term data sets. Our vision of the AeroNet network, combined with high-throughput sequencing (HTS) and well-designed sampling strategies, may contribute significantly to a national biovigilance network for protecting plants of agricultural and economic importance in Canada.
The current study compared the performance of spore samplers for collecting broad-spectrum air- and rain-borne fungal pathogens using a metabarcoding approach. The results provided a thorough characterization of the aeromycobiota in the coastal regions of Canada in relation to the influence of climatic factors. This study lays the methodological basis to eventually develop knowledge-based guidance on pest surveillance by assisting in the selection of appropriate spore samplers.
This study evaluated effects of feeding low-bush wild blueberry (LBP) and organic American cranberry (CRP) pomaces without or with multienzyme supplement (ENZ) on growth performance, organ weight and ...plasma metabolites in broiler chickens. Nonenzyme-fed (no-ENZ: n = 1,575) and enzyme-fed (ENZ: n = 1,575) day-old male Cobb500 broilers were placed in floor pens (45 chicks/pen) and allocated to five corn-soybean meal-based diets: a basal diet supplemented with either bacitracin methylene disalicylate (BMD, 55 mg/kg), 0.5 or 1% of CRP or LBP in a 2 × 5 factorial design for 35-day experiment. Body weight (BW), feed intake (FI) and mortality were recorded whereas BW gain (BWG) and feed conversion ratio (FCR) were calculated. Birds were sampled at days 21 and 35 for organ weights and plasma metabolites. There were no interactions between diet and ENZ on any parameter (P > 0.05) and no effect of ENZ on overall (d 0–35) growth performance and organ weights (P > 0.05). Birds fed BMD were heavier (P < 0.05) at d 35 and had better overall FCR than berry-supplemented birds. Birds fed 1% LBP had poor FCR than birds fed 0.5% CRP. Birds fed LBP exhibited heavier liver (P < 0.05) than birds fed BMD or 1% CRP. The highest plasma concentrations of aspartate transaminase (AST), creatine kinase (CK) at d 28 and gamma-glutamyl transferase (GGT) at d 35 were found in ENZ-fed birds (P < 0.05). At d 28, birds fed 0.5% LBP showed higher plasma AST and CK concentrations (P < 0.05). However, CRP feeding resulted in a lower plasma CK level compared with BMD feeding (P < 0.05). The lowest cholesterol level was detected in 1% CRP-fed birds. In conclusion, this study showed no ENZ effects to potentiate berry pomaces on the overall growth performance of broilers (P < 0.05. However, plasma profiles revealed the potential of ENZ to modulate the metabolism of pomace-fed broilers. LBP increased BW during the starter phase, while CRP increased BW during the grower phase.
Enterococci are now frequent causative agents of nosocomial infections. In this study, we analyzed the frequency and distribution of antibiotic resistance and virulence genotypes of Enterococcus ...isolates from broiler chickens. Fecal and cecal samples from nine commercial poultry farms were collected to quantify total enterococci. Sixty-nine presumptive enterococci were isolated and identified by API 20 Strep, and their susceptibilities to antibiotics were determined. Genotypes were assessed through the use of a novel DNA microarray carrying 70 taxonomic, 17 virulence, and 174 antibiotic resistance gene probes. Total enterococcal counts were different from farm to farm and between sample sources (P < 0.01). Fifty-one (74%) of the isolates were identified as E. faecium, whereas nine (13%), seven (10%), and two (3%) isolates were identified as E. hirae, E. faecalis, and E. gallinarum, respectively. Multiple-antibiotic resistance was evident in E. faecium and E. faecalis isolates. The most common multiple-antibiotic resistance phenotype was Bac Ery Tyl Lin Str Gen Tet Cip. Genes conferring resistance to aminoglycoside (aac, aacA-aphD, aadB, aphA, sat4), macrolide (ermA, ermB, ermAM, msrC), tetracycline (tetL, tetM, tetO), streptogramin (satG_vatE8), bacitracin (bcrR), and lincosamide (linB) antibiotics were detected in corresponding phenotypes. A range of 9 to 12 different virulence genes was found in E. faecalis, including ace, agg, agrBEfs (agrB gene of E. faecalis), cad1, the cAM373 and cCF10 genes, cob, cpd1, cylAB, efaAEfs, and gelE. All seven E. faecalis isolates were found to carry the gelE gene and to hydrolize gelatin and bile salts. Results from this study showed the presence of enterococci of public and environmental health concerns in broiler chicken farms and demonstrated the utility of a microarray to quickly and reliably analyze resistance and virulence genotypes of Enterococcus spp.
•Retail poultry meat could be a reservoir of AMR ExPEC.•AMR ExPEC from retail poultry meat reduced the life span of C. elegans.•No correlation between ARGs and VGs was noted for the virulence in C. ...elegans.•Whole-genome sequencing identified plasmid-encoded multidrug resistance in ExPEC.
Healthy poultry can be a reservoir for extraintestinal pathogenic Escherichia coli (ExPEC), some of which could be multidrug resistant to antimicrobials. These ExPEC strains could contaminate the environment and/or food chain representing thus, food safety and human health risk. However, few studies have shown the virulence of poultry-source antimicrobial-resistant (AMR) ExPEC in humans. This study characterized AMR ExPEC and investigated the virulence potential of some of their isolates in a Caenorhabditis elegans infection model. A total of 46 E. coli isolates from poultry (chicken, n = 29; turkey, n = 12) retail meats and chicken feces (n = 4), or humans (n = 1) were sequenced and identified as ExPEC. Except eight, all remaining 38 ExPEC isolates were resistant to at least one antibiotic and carried corresponding antimicrobial resistance genes (ARGs). About 27 of the 46 ExPEC isolates were multidrug-resistant (≥3 antibiotic classes). Seven ExPEC isolates from chicken or turkey meats were of serotype O25:H4 and sequence type (ST) 131 which clustered with an isolate from a human urinary tract infection (UTI) case having the same serotype and ST. The C. elegans challenge model using eight of studied ExPEC isolates harboring various ARGs and virulence genes (VGs) showed that regardless of their ARG or VG numbers in tested poultry meat and feces, ExPEC significantly reduced the life span of the nematode (P < 0.05) similarly to a human UTI isolate. This study indicated the pathogenic potential of AMR ExPEC from retail poultry meat or feces, but more studies are warranted to establish their virulence in poultry and human. Furthermore, relationships between specific resistance profiles and/or VGs in these E. coli isolates for their pathogenicity deserve investigations.
There is a need to develop cost-effective approaches to modulate gut microbiota, promote bird health, and prevent infections in pasture-raised broiler chickens. The present study evaluated the ...efficacy of organic wild blueberry (Vaccinium angustifolium) also called low-bush blueberry pomace (LBBP)-supplemented feed to modulate the chicken gut microbiota, and blood metabolites in order to improve bird health and productivity. Slow-growing broiler chickens were reared on pasture up to 64 D for sampling after 2 wk of treatment during brooding with 0, 1, and 2% LBBP in feed. Intestinal samples were collected at different time-points throughout the trial for bacterial culture and microbial community analysis by 16S rRNA gene sequencing using Illumina MiSeq. Blood sera were also analyzed for metabolites at each sampling time. Of the 14 bacterial phyla, the predominant taxa across all sampling time-points were Firmicutes, Proteobacteria, Bacteroidetes, and Tenericutes, representing >97% of all sequences. Bacteroidetes seemed to be replacing Firmicutes by LBBP supplementation, with the most noticeable effect at day 64 with 1% LBBP. LBBP inclusion enriched Lactobacillus, Bacteroides, and Bifidobacterium, while Escherichia coli, Clostridium_Clostridiaceae, Helicobacter, and Enterococcus showed higher abundances in control birds at the end of trial. Principal co-ordinate analysis showed a clear clustering of the intestinal samples from control and LBBP-treated groups at day 29. Application of LBBP resulted in a decrease (P < 0.05) in cholesterol at day 21, and an increase (P < 0.05) in high-density lipoprotein cholesterol in 14-day-old broilers. Higher (P < 0.05) levels of phosphorus, magnesium, and globulin at day 21 as well as iron and albumin at day 36 were also observed in 1% LBBP-fed birds. Despite limitations consisting essentially of low sampled birds for measurements, this study indicated that dietary supplementation of LBBP could positively influence gut microbiota and blood metabolites that may contribute to the overall health of pasture-raised broiler chickens.
The objective of this study was to characterize antimicrobial resistance (AMR) and virulence genotypes of Enterococcus spp. particularly Enterococcus faecalis isolated from retail meats purchased ...(2007–2008) in Alberta, Canada. Unconditional statistical associations between AMR pheno- and genotypes and virulence genotypes were determined. A total of 532 enterococci comprising one isolate from each positive sample were analyzed for antimicrobial susceptibility. A customized enterococcal microarray was used for species identification and the detection of AMR and virulence genes. E. faecalis was found in >94% of poultry samples and in about 73% of beef and 86% of pork samples. Enterococcus faecium was not found in turkey meat and its prevalence was 2% in beef and pork and 4% in chicken samples. None of the enterococci isolates were resistant to the clinically important drugs ciprofloxacin, daptomycin, linezolid and vancomycin. Multiresistance (≥3 antimicrobials) was more common in E. faecalis (91%) isolated from chicken and turkey (91%) than those isolated from beef (14%) or pork (45%). Resistance to aminoglycosides was also noted at varying degrees. The most common resistance genes found in E. faecalis were aminoglycosides (aac, aphA3, aadE, sat4, aadA), macrolides (ermB, ermA), tetracyclines (tetM, tetL, tetO), streptogramin (vatE), bacitracin (bcrR) and lincosamide (linB). Virulence genes expressing aggregation substances (agg) and cytolysin (cylA, cylB, cylL, cylM) were found more frequently in poultry E. faecalis and were unconditionally associated with tetM, linB and bcrR resistance genes. Other virulence genes coding for adhesion (ace, efaAfs), gelatinase (gelE) were also found in the majority of E. faecalis. Significant statistical associations were found between resistance and virulence genotypes, suggesting their possible physical link on a common genetic element. This study underscores the importance of E. faecalis as a reservoir of resistance and virulence genes and their potential transfer to humans through consumption of contaminated undercooked meat.
►Enterococcus faecalis was found in >94% of poultry samples. ►Resistance to clinically important drugs was not found in any enterococci. ►Resistance genes were more commonly found in E. faecalis from poultry meats. ►Virulence genes were also found more frequently in poultry E. faecalis. ►Statistical associations were found between resistance and virulence genotypes.
Development of viable alternatives to antibiotics to control necrotic enteritis (NE) caused by Clostridium perfringens is becoming urgent for chicken production due to pessures on poultry producers ...to limit or stop the use of antibiotics in feed. We have previously identified citral as a potential alternative to antibiotics. Citral has strong antimicrobial activity and can be encasupsulated in a powder form for protection from loss during feed processing, storage, and intestinal delivery. In the present study, encapsulated citral was evaluated both in vitro and in vivo for its antimicrobial activity against C. perfringens. Encapsulation did not adversely affect the antimicrobial activity of citral. In addition, encapsulated citral was superior to the unencapsulated form in retaining its antimicrobial activity after treatment with simulated gastrointestinal fluids and in the presence of chicken intestinal digesta. In addition, the higher antimicrobial activity of encapsulated citral was confirmed in digesta samples from broilers that had been gavaged with encapsulated or unencapsulated citral. In broilers infected with C. perfringens, the diets supplemented with encapsualted citral at both 250 and 650 μg/g significantly reduced intestinal NE lesions, which was comparable to the effect of bacitracin- and salinomycin-containing diets. However, supplementation with the encapsulated citral appeared to have no significant impact on the intestinal burden of Lactobacillus. These data indicate that citral can be used to control NE in chickens after proper protection by encapsulation.
Cranberry and blueberry pomaces are rich in antimicrobial and antioxidant compounds. They have been identified as potential antibiotic alternatives in animal feed, but their antioxidative capacity ...for maintaining or improving the meat quality in broilers is not well documented. This study was to determine whether cranberry and wild blueberry pomaces in diets could positively influence the broiler meat quality. A total of 3,150 broilers were randomly allotted to 10 dietary treatments with bacitracin methylene disalicylate, wild cranberry pomace (CRP) (0.5 and 1% of the basal diet), and wild blueberry pomace (BLP) (0.5 and 1% of the basal diet) alone or in combination with a mixture of feed enzymes. The results showed that supplementation with the CRP or BLP did not affect meat lightness and yellowness, while the deeper red meat (higher a∗ values) was observed in the birds receiving the diet containing 0.5% BLP against those in CRP treatments (P = 0.015). In addition, inclusion of CRP or BLP in the diet did not change meat texture and proximate composition (moisture, protein, fat, ash) irrespective of pomace concentrations. Although there were no obvious effects of CRP or BLP supplementation on meat antioxidant capacity and the incidence of myopathies (P > 0.05), the upward trend of antioxidant capacity and less severity of woody breast were observed in birds fed with 0.5% CRP. Furthermore, supplementation of 0.5 or 1.0% CRP without the enzyme resulted in higher mRNA levers of Nrf, Gpx2, and HO-1 (P < 0.05). Taken together, 0.5% CRP supplementation without the enzyme could potentially maintain meat quality and attenuate the severity of woody breast.
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