scholarly journals Comparative Genomic Analysis of 450 Strains of Salmonella enterica Isolated from Diseased Animals

Genes ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 1025
Author(s):  
Shaohua Zhao ◽  
Cong Li ◽  
Chih-Hao Hsu ◽  
Gregory H. Tyson ◽  
Errol Strain ◽  
...  

Salmonella is a leading cause of bacterial infections in animals and humans. We sequenced a collection of 450 Salmonella strains from diseased animals to better understand the genetic makeup of their virulence and resistance features. The presence of Salmonella pathogenicity islands (SPIs) varied by serotype. S. Enteritidis carried the most SPIs (n = 15), while S. Mbandaka, S. Cerro, S. Meleagridis, and S. Havana carried the least (n = 10). S. Typhimurium, S. Choleraesuis, S. I 4,5,12:i:-, and S. Enteritidis each contained the spv operon on IncFII or IncFII-IncFIB hybrid plasmids. Two S. IIIa carried a spv operon with spvD deletion on the chromosome. Twelve plasmid types including 24 hybrid plasmids were identified. IncA/C was frequently associated with S. Newport (83%) and S. Agona (100%) from bovine, whereas IncFII (100%), IncFIB (100%), and IncQ1 (94%) were seen in S. Choleraesuis from swine. IncX (100%) was detected in all S. Kentucky from chicken. A total of 60 antimicrobial resistance genes (ARGs), four disinfectant resistances genes (DRGs) and 33 heavy metal resistance genes (HMRGs) were identified. The Salmonella strains from sick animals contained various SPIs, resistance genes and plasmid types based on the serotype and source of the isolates. Such complicated genomic structures shed light on the strain characteristics contributing to the severity of disease and treatment failures in Salmonella infections, including those causing illnesses in animals.

2007 ◽  
Vol 51 (8) ◽  
pp. 3004-3007 ◽  
Author(s):  
Ying-Tsong Chen ◽  
Tsai-Ling Lauderdale ◽  
Tsai-Lien Liao ◽  
Yih-Ru Shiau ◽  
Hung-Yu Shu ◽  
...  

ABSTRACT A 269-kilobase conjugative plasmid, pK29, from a Klebsiella pneumoniae strain was sequenced. The plasmid harbors multiple antimicrobial resistance genes, including those encoding CMY-8 AmpC-type and CTX-M-3 extended-spectrum β-lactamases in the common backbone of IncHI2 plasmids. Mechanisms for dissemination of the resistance genes are highlighted in comparative genomic analyses.


2017 ◽  
Vol 61 (7) ◽  
Author(s):  
Weihua Huang ◽  
Guiqing Wang ◽  
Robert Sebra ◽  
Jian Zhuge ◽  
Changhong Yin ◽  
...  

ABSTRACT The extended-spectrum-β-lactamase (ESBL)- and Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae represent serious and urgent threats to public health. In a retrospective study of multidrug-resistant K. pneumoniae, we identified three clinical isolates, CN1, CR14, and NY9, carrying both bla CTX-M and bla KPC genes. The complete genomes of these three K. pneumoniae isolates were de novo assembled by using both short- and long-read whole-genome sequencing. In CR14 and NY9, bla CTX-M and bla KPC were carried on two different plasmids. In contrast, CN1 had one copy of bla KPC-2 and three copies of bla CTX-M-15 integrated in the chromosome, for which the bla CTX-M-15 genes were linked to an insertion sequence, ISEcp1, whereas the bla KPC-2 gene was in the context of a Tn4401a transposition unit conjugated with a PsP3-like prophage. Intriguingly, downstream of the Tn4401a-bla KPC-2-prophage genomic island, CN1 also carried a clustered regularly interspaced short palindromic repeat (CRISPR)-cas array with four spacers targeting a variety of K. pneumoniae plasmids harboring antimicrobial resistance genes. Comparative genomic analysis revealed that there were two subtypes of type I-E CRISPR-cas in K. pneumoniae strains and suggested that the evolving CRISPR-cas, with its acquired novel spacer, induced the mobilization of antimicrobial resistance genes from plasmids into the chromosome. The integration and dissemination of multiple copies of bla CTX-M and bla KPC from plasmids to chromosome depicts the complex pandemic scenario of multidrug-resistant K. pneumoniae. Additionally, the implications from this study also raise concerns for the application of a CRISPR-cas strategy against antimicrobial resistance.


2017 ◽  
Vol 5 (33) ◽  
Author(s):  
Mike L. Dyall-Smith ◽  
Yuhong Liu ◽  
Helen Billman-Jacobe

ABSTRACT We report the genome sequence of a monophasic Salmonella enterica subsp. enterica Typhimurium strain (TW-Stm6) isolated in Australia that is similar to epidemic multidrug-resistant strains from Europe and elsewhere. This strain carries additional antibiotic and heavy-metal resistance genes on a large (275-kb) IncHI2 plasmid.


2018 ◽  
Vol 85 (2) ◽  
Author(s):  
Liangzhi Li ◽  
Zhenghua Liu ◽  
Delong Meng ◽  
Xueduan Liu ◽  
Xing Li ◽  
...  

ABSTRACTMembers of the genusAcidithiobacillus, which can adapt to extremely high concentrations of heavy metals, are universally found at acid mine drainage (AMD) sites. Here, we performed a comparative genomic analysis of 37 strains within the genusAcidithiobacillusto answer the untouched questions as to the mechanisms and the evolutionary history of metal resistance genes inAcidithiobacillusspp. The results showed that the evolutionary history of metal resistance genes inAcidithiobacillusspp. involved a combination of gene gains and losses, horizontal gene transfer (HGT), and gene duplication. Phylogenetic analyses revealed that metal resistance genes inAcidithiobacillusspp. were acquired by early HGT events from species that shared habitats withAcidithiobacillusspp., such asAcidihalobacter,Thiobacillus,Acidiferrobacter, andThiomonasspecies. Multicopper oxidase genes involved in copper detoxification were lost in iron-oxidizingAcidithiobacillus ferridurans,Acidithiobacillus ferrivorans, andAcidithiobacillus ferrooxidansand were replaced by rusticyanin genes during evolution. In addition, widespread purifying selection and the predicted high expression levels emphasized the indispensable roles of metal resistance genes in the ability ofAcidithiobacillusspp. to adapt to harsh environments. Altogether, the results suggested thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. This study sheds light on the distribution, organization, functionality, and complex evolutionary history of metal resistance genes inAcidithiobacillusspp.IMPORTANCEHorizontal gene transfer (HGT), natural selection, and gene duplication are three main engines that drive the adaptive evolution of microbial genomes. Previous studies indicated that HGT was a main adaptive mechanism in acidophiles to cope with heavy-metal-rich environments. However, evidences of HGT inAcidithiobacillusspecies in response to challenging metal-rich environments and the mechanisms addressing how metal resistance genes originated and evolved inAcidithiobacillusare still lacking. The findings of this study revealed a fascinating phenomenon of putative cross-phylum HGT, suggesting thatAcidithiobacillusspp. recruited and consolidated additional novel functionalities during the adaption to challenging environments via HGT, gene duplication, and purifying selection. Altogether, the insights gained in this study have improved our understanding of the metal resistance strategies ofAcidithiobacillusspp.


2021 ◽  
Vol 9 (6) ◽  
pp. 1118
Author(s):  
Kodjovi D. Mlaga ◽  
Vincent Garcia ◽  
Philippe Colson ◽  
Ruimy Raymond ◽  
Jean-Marc Rolain ◽  
...  

Here, we performed a comparative genomic analysis of all available genomes of E. faecalis (n = 1591) and E. faecium (n = 1981) and investigated the association between the presence or absence of CRISPR-Cas systems, endonuclease/anti-endonuclease systems and the acquisition of antimicrobial resistance, especially vancomycin resistance genes. Most of the analysed Enterococci were isolated from humans and less than 14% of them were from foods and animals. We analysed and detected CRISPR–Cas systems in 75.36% of E. faecalis genomes and only 4.89% of E. faecium genomes with a significant difference (p-value < 10−5). We found a negative correlation between the number of CRISPR–Cas systems and genome size (r = −0.397, p-value < 10−5) and a positive correlation between the genome %GC content and the number of CRISPR–Cas systems (r = 0.215, p-value < 10−5). Our findings showed that the presence of the anti-endonuclease ardA gene may explain the decrease in the number of CRISPR–Cas systems in E. faecium, known to deactivate the endonucleases’ protective activities and enable the E. faecium genome to be versatile in acquiring mobile genetic elements, including carriers of antimicrobial resistance genes, especially vanB. Most importantly, we observed that there was a direct association between the absence of CRISPR–Cas, the presence of the anti-CRISPR ardA gene and the acquisition of vancomycin resistance genes.


2021 ◽  
Vol 12 ◽  
Author(s):  
Cong Li ◽  
Gregory H. Tyson ◽  
Chih-Hao Hsu ◽  
Lucas Harrison ◽  
Errol Strain ◽  
...  

Salmonella enterica is a significant and phylogenetically diverse zoonotic pathogen. To understand its genomic heterogeneity and antimicrobial resistance, we performed long-read sequencing on Salmonella isolated from retail meats and food animals. A collection of 134 multidrug-resistant isolates belonging to 33 serotypes were subjected to PacBio sequencing. One major locus of diversity among these isolates was the presence and orientation of Salmonella pathogenic islands (SPI), which varied across different serotypes but were largely conserved within individual serotypes. We also identified insertion of an IncQ resistance plasmid into the chromosome of fourteen strains of serotype I 4,[5],12:i:– and the Salmonella genomic island 1 (SGI-1) in five serotypes. The presence of various SPIs, SGI-1 and integrated plasmids contributed significantly to the genomic variability and resulted in chromosomal resistance in 55.2% (74/134) of the study isolates. A total of 93.3% (125/134) of isolates carried at least one plasmid, with isolates carrying up to seven plasmids. We closed 233 plasmid sequences of thirteen replicon types, along with twelve hybrid plasmids. Some associations between Salmonella isolate source, serotype, and plasmid type were seen. For instance, IncX plasmids were more common in serotype Kentucky from retail chicken. Plasmids IncC and IncHI had on average more than five antimicrobial resistance genes, whereas in IncX, it was less than one per plasmid. Overall, 60% of multidrug resistance (MDR) strains that carried &gt;3 AMR genes also carried &gt;3 heavy metal resistance genes, raising the possibility of co-selection of antimicrobial resistance in the presence of heavy metals. We also found nine isolates representing four serotypes that carried virulence plasmids with the spv operon. Together, these data demonstrate the power of long-read sequencing to reveal genomic arrangements and integrated plasmids with a high level of resolution for tracking and comparing resistant strains from different sources. Additionally, the findings from this study will help expand the reference set of closed Salmonella genomes that can be used to improve genome assembly from short-read data commonly used in One Health antimicrobial resistance surveillance.


2017 ◽  
Author(s):  
Cameron J. Reid ◽  
Ethan R. Wyrsch ◽  
Piklu Roy Chowdhury ◽  
Tiziana Zingali ◽  
Michael Liu ◽  
...  

AbstractPorcine faecal waste is a serious environmental pollutant. Carriage of antimicrobial resistance and virulence-associated genes (VAGs) and the zoonotic potential of commensalEscherichia colifrom swine is largely unknown. Furthermore, little is known about the role of commensalE. colias contributors to the mobilisation of antimicrobial resistance genes between food animals and the environment. Here, we report whole genome sequence analysis of 141E. colifrom the faeces of healthy pigs. Most strains belonged to phylogroups A and B1 and carried i) a class 1 integron; ii) VAGs linked with extraintestinal infection in humans; iii) antimicrobial resistance genesblaTEM, aphAl, cmlA, strAB, tet(A)A,dfrA12, dfrA5, sul1, sul2, sul3; iv)IS26;and v) heavy metal resistance genes (merA, cusA, terA). Carriage of the sulphonamide resistance genesul3was notable in this study. The 141 strains belonged to 42 multilocus sequence types, but clonal complex 10 featured prominently. Structurally diverse class 1 integrons that were frequently associated with IS26 carried unique genetic features that were also identified in extraintestinal pathogenicE. coli(ExPEC) from humans. This study provides the first detailed genomic analysis and point of reference for commensalE. coliof porcine origin, facilitating tracking of specific lineages and the mobile resistance genes they carry.Conflict of Interest StatementNone to declare.


2008 ◽  
Vol 74 (9) ◽  
pp. 2852-2863 ◽  
Author(s):  
Shawn R. Starkenburg ◽  
Frank W. Larimer ◽  
Lisa Y. Stein ◽  
Martin G. Klotz ◽  
Patrick S. G. Chain ◽  
...  

ABSTRACT The alphaproteobacterium Nitrobacter hamburgensis X14 is a gram-negative facultative chemolithoautotroph that conserves energy from the oxidation of nitrite to nitrate. Sequencing and analysis of the Nitrobacter hamburgensis X14 genome revealed four replicons comprised of one chromosome (4.4 Mbp) and three plasmids (294, 188, and 121 kbp). Over 20% of the genome is composed of pseudogenes and paralogs. Whole-genome comparisons were conducted between N. hamburgensis and the finished and draft genome sequences of Nitrobacter winogradskyi and Nitrobacter sp. strain Nb-311A, respectively. Most of the plasmid-borne genes were unique to N. hamburgensis and encode a variety of functions (central metabolism, energy conservation, conjugation, and heavy metal resistance), yet ∼21 kb of a ∼28-kb “autotrophic” island on the largest plasmid was conserved in the chromosomes of Nitrobacter winogradskyi Nb-255 and Nitrobacter sp. strain Nb-311A. The N. hamburgensis chromosome also harbors many unique genes, including those for heme-copper oxidases, cytochrome b 561, and putative pathways for the catabolism of aromatic, organic, and one-carbon compounds, which help verify and extend its mixotrophic potential. A Nitrobacter “subcore” genome was also constructed by removing homologs found in strains of the closest evolutionary relatives, Bradyrhizobium japonicum and Rhodopseudomonas palustris. Among the Nitrobacter subcore inventory (116 genes), copies of genes or gene clusters for nitrite oxidoreductase (NXR), cytochromes associated with a dissimilatory nitrite reductase (NirK), PII-like regulators, and polysaccharide formation were identified. Many of the subcore genes have diverged significantly from, or have origins outside, the alphaproteobacterial lineage and may indicate some of the unique genetic requirements for nitrite oxidation in Nitrobacter.


2012 ◽  
Vol 79 (2) ◽  
pp. 663-671 ◽  
Author(s):  
Eun Jin Choi ◽  
Hyun Mi Jin ◽  
Seung Hyeon Lee ◽  
Renukaradhya K. Math ◽  
Eugene L. Madsen ◽  
...  

ABSTRACTPseudoxanthomonas spadixBD-a59, isolated from gasoline-contaminated soil, has the ability to degrade all six BTEX (benzene, toluene, ethylbenzene, ando-,m-, andp-xylene) compounds. The genomic features of strain BD-a59 were analyzed bioinformatically and compared with those of another fully sequencedPseudoxanthomonasstrain,P. suwonensis11-1, which was isolated from cotton waste compost. The genome of strain BD-a59 differed from that of strain 11-1 in many characteristics, including the number of rRNA operons, dioxygenases, monooxygenases, genomic islands (GIs), and heavy metal resistance genes. A high abundance of phage integrases and GIs and the patterns in several other genetic measures (e.g., GC content, GC skew, Karlin signature, and clustered regularly interspaced short palindromic repeat [CRISPR] gene homology) indicated that strain BD-a59's genomic architecture may have been altered through horizontal gene transfers (HGT), phage attack, and genetic reshuffling during its evolutionary history. The genes for benzene/toluene, ethylbenzene, and xylene degradations were encoded on GI-9, -13, and -21, respectively, which suggests that they may have been acquired by HGT. We used bioinformatics to predict the biodegradation pathways of the six BTEX compounds, and these pathways were proved experimentally through the analysis of the intermediates of each BTEX compound using a gas chromatograph and mass spectrometry (GC-MS). The elevated abundances of dioxygenases, monooxygenases, and rRNA operons in strain BD-a59 (relative to strain 11-1), as well as other genomic characteristics, likely confer traits that enhance ecological fitness by enabling strain BD-a59 to degrade hydrocarbons in the soil environment.


2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Chongyang Wu ◽  
Chaoqin Lin ◽  
Xinyi Zhu ◽  
Hongmao Liu ◽  
Wangxiao Zhou ◽  
...  

In this work, by high-throughput sequencing, antibiotic resistance genes, including class A (blaCTX-M, blaZ, blaTEM, blaVEB, blaKLUC, and blaSFO), class C (blaSHV, blaDHA, blaMIR, blaAZECL-29, and blaACT), and class D (blaOXA) β-lactamase genes, were identified among the pooled genomic DNA from 212 clinical Enterobacter cloacae isolates. Six blaMIR-positive E. cloacae strains were identified, and pulsed-field gel electrophoresis (PFGE) showed that these strains were not clonally related. The complete genome of the blaMIR-positive strain (Y546) consisted of both a chromosome (4.78 Mb) and a large plasmid pY546 (208.74 kb). The extended-spectrum β-lactamases (ESBLs) (blaSHV-12 and blaCTX-M-9a) and AmpC (blaMIR) were encoded on the chromosome, and the pY546 plasmid contained several clusters of genes conferring resistance to metals, such as copper (pco), arsenic (ars), tellurite (ter), and tetrathionate (ttr), and genes encoding many divalent cation transporter proteins. The comparative genomic analyses of the whole plasmid sequence and of the heavy metal resistance gene-encoding regions revealed that the plasmid sequences of Klebsiella pneumoniae (such as pKPN-332, pKPN-3967, and pKPN-262) shared the highest similarity with those of pY546. It may be concluded that a variety of β-lactamase genes present in E. cloacae which confer resistance to β-lactam antibiotics and the emergence of plasmids carrying heavy metal resistance genes in clinical isolates are alarming and need further surveillance.


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