scholarly journals Assignment of virus and antimicrobial resistance genes to microbial hosts in a complex microbial community by combined long-read assembly and proximity ligation

2018 ◽  
Author(s):  
Derek M. Bickhart ◽  
Mick Watson ◽  
Sergey Koren ◽  
Kevin Panke-Buisse ◽  
Laura M. Cersosimo ◽  
...  

AbstractThe characterization of microbial communities by metagenomic approaches has been enhanced by recent improvements in short-read sequencing efficiency and assembly algorithms. We describe the results of adding long-read sequencing to the mix of technologies used to assemble a highly complex cattle rumen microbial community, and compare the assembly to current short read-based methods applied to the same sample. Contigs in the long-read assembly were 7-fold longer on average, and contained 7-fold more complete open reading frames (ORF), than the short read assembly, despite having three-fold lower sequence depth. The linkages between long-read contigs, provided by proximity ligation data, supported identification of 188 novel viral-host associations in the rumen microbial community that suggest cross-species infectivity of specific viral strains. The improved contiguity of the long-read assembly also identified 94 antimicrobial resistance genes, compared to only seven alleles identified in the short-read assembly. Overall, we demonstrate a combination of experimental and computational methods that work synergistically to improve characterization of biological features in a highly complex rumen microbial community.

2019 ◽  
Author(s):  
Narjol Gonzalez-Escalona ◽  
Marc A. Allard ◽  
Eric W. Brown ◽  
Shashi Sharma ◽  
Maria Hoffmann

AbstractWhole genome sequencing can provide essential public health information. However, it is now known that widely used short-read methods have the potential to miss some randomly-distributed segments of genomes. This can prevent phages, plasmids, and virulence factors from being detected or properly identified. Here, we compared assemblies of three complete STEC O26:H11 genomes from two different sequence types (ST21 and 29), each acquired using the MiSeq-Nextera XT, MinION nanopore-based sequencing, and Pacific Biosciences (PacBio) sequencing. Each closed genome consisted of a single chromosome, approximately 5.7 Mb for CFSAN027343, 5.6 Mb for CFSAN027346, and 5.4 MB for CFSAN027350. However, short-read WGS using MiSeq-Nextera failed to identify some virulence genes in plasmids and on the chromosome, both of which were detected using the long-read platforms. Results from long-read MinION and PacBio allowed us to identify differences in plasmid content: a single 88 kb plasmid in CFSAN027343; a 157kb plasmid in CFSAN027350; and two plasmids in CFSAN027346 (one 95 Kb, one 72 Kb). These data enabled rapid characterization of the virulome, detection of antimicrobial genes, and composition/location of Stx phages. Taken together, positive correlations between the two long-read methods for determining plasmids, virulome, antimicrobial resistance genes, and phage composition support MinION sequencing as one accurate and economical option for closing STEC genomes and identifying specific virulence markers.


2020 ◽  
Vol 67 (4) ◽  
pp. 460-466
Author(s):  
Katherine E. L. Worsley‐Tonks ◽  
Elizabeth A. Miller ◽  
Stanley D. Gehrt ◽  
Shane C. McKenzie ◽  
Dominic A. Travis ◽  
...  

2021 ◽  
Author(s):  
Jenna M Swarthout ◽  
Erica R Fuhrmeister ◽  
Latifah Hamzah ◽  
Angela Harris ◽  
Mir A. Ahmed ◽  
...  

Background Low- and middle-income countries (LMICs) bear the largest mortality burden due to antimicrobial-resistant infections. Small-scale animal production and free-roaming domestic animals are common in many LMICs, yet data on zoonotic exchange of gut bacteria and antimicrobial resistance genes (ARGs) in low-income communities are sparse. Differences between rural and urban communities in population density, antibiotic use, and cohabitation with animals likely influence the frequency of transmission of gut bacterial communities and ARGs between humans and animals. Here, we determined the similarity in gut microbiomes, using 16S rRNA gene amplicon sequencing, and resistomes, using long-read metagenomics, between humans, chickens, and goats in rural compared to urban Bangladesh. Results Gut microbiomes were more similar between humans and chickens in rural (where cohabitation is more common) compared to urban areas, but there was no difference for humans and goats. Urbanicity did not impact the similarity of human and animal resistomes; however, ARG abundance was higher in urban animals compared to rural animals. We identified substantial overlap of ARG alleles in humans and animals in both settings. Humans and chickens had more overlapping ARG alleles than humans and goats. All fecal hosts carried ARGs on contigs classified as potentially pathogenic bacteria, including Escherichia coli, Campylobacter jejuni, Clostridiodes difficile, and Klebsiella pneumoniae. Conclusions While the development of antimicrobial resistance in animal gut microbiomes and subsequent transmission to humans has been demonstrated in intensive farming environments and high-income countries, evidence of zoonotic exchange of antimicrobial resistance in LMIC communities is lacking. This research provides genomic evidence of overlap of antimicrobial resistance genes between humans and animals, especially in urban communities, and highlights chickens as important reservoirs of antimicrobial resistance. Chicken and human gut microbiomes were more similar in rural Bangladesh, where cohabitation is more common. Incorporation of long-read metagenomics enabled characterization of bacterial hosts of resistance genes, which has not been possible in previous culture-independent studies using only short-read sequencing. These findings highlight the importance of developing strategies for combatting antimicrobial resistance that account for chickens being reservoirs of ARGs in community environments, especially in urban areas.


2020 ◽  
Vol 2 (7A) ◽  
Author(s):  
Ebenezer Foster-Nyarko ◽  
Nabil-Fareed Alikhan ◽  
Anuradha Ravi ◽  
Gaëtan Thilliez ◽  
Nicholas Thomson ◽  
...  

Increasing contact between humans and non-human primates provides an opportunity for the transfer of potential pathogens or antimicrobial resistance between different host species. We have investigated genetic diversity and antimicrobial resistance in Escherichia coli isolates from a range of non-human primates dispersed across the Gambia: patas monkey (n=1), western colobus monkey (n=6), green monkey (n=14) and guinea baboon (n=22). From 43 stools, we recovered 99 isolates. We performed Illumina whole-genome shotgun sequencing on all isolates and nanopore long-read sequencing on isolates with antimicrobial resistance genes. We inferred the evolution of E. coli in this population using the EnteroBase software environment. We identified 43 sequence types (ten of them novel), spanning five of the eight known phylogroups of E. coli. Many of the observed sequence types and phylotypes from non-human primates have been associated with human extra-intestinal infection and carry virulence characteristics associated with disease in humans, particularly ST73, ST217 and ST681. However, we found a low prevalence of antimicrobial resistance genes in isolates from non-human primates. Hierarchical clustering showed that ST442 and ST349 from non-human primates are closely related to isolates from human infections, suggesting recent exchange of bacteria between humans and monkeys. Our results are of public health importance, considering the increasing contact between humans and wild primates.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
R. V. Pereira ◽  
C. Foditsch ◽  
J. D. Siler ◽  
S. C. Dulièpre ◽  
C. Altier ◽  
...  

Abstract The objective of this study was to evaluate the longitudinal effect of enrofloxacin or tulathromycin use in calves at high risk of bovine respiratory disease (BRD) on antimicrobial resistance genes and mutation in quinolone resistance-determining regions (QRDR) in fecal E. coli. Calves at high risk of developing BRD were randomly enrolled in one of three groups receiving: (1) enrofloxacin (ENR; n = 22); (2) tulathromycin (TUL; n = 24); or (3) no treatment (CTL; n = 21). Fecal samples were collected at enrollment and at 7, 28, and 56 days after beginning treatment, cultured for Escherichiacoli (EC) and DNA extracted. Isolates were screened for cephalosporin, quinolone and tetracycline resistance genes using PCR. QRDR screening was conducted using Sanger sequencing. The only resistance genes detected were aac(6′)Ib-cr (n = 13), bla-CTX-M (n = 51), bla-TEM (n = 117), tetA (n = 142) and tetB (n = 101). A significantly higher detection of gyrA mutated at position 248 at time points 7 (OR = 11.5; P value = 0.03) and 28 (OR = 9.0; P value = 0.05) was observed in the ENR group when compared to calves in the control group. Our findings support a better understanding of the potential impacts from the use of enrofloxacin in calves on the selection and persistence of resistance.


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