scholarly journals Microfluidic PCR Combined with Pyrosequencing for Identification of Allelic Variants with Phenotypic Associations among Targeted Salmonella Genes

2012 ◽  
Vol 78 (20) ◽  
pp. 7480-7482 ◽  
Author(s):  
Min Yue ◽  
Robert Schmieder ◽  
Robert A. Edwards ◽  
Shelley C. Rankin ◽  
Dieter M. Schifferli

ABSTRACTA novel targeted massive parallel sequencing approach identified genetic variation in eight known or predicted fimbrial adhesins for 46Salmonellastrains. The results highlight associations between specific adhesin alleles, host species, and antimicrobial resistance. The differentiation of allelic variants has potential applications for diagnostic microbiology and epidemiological investigations.

Author(s):  
Aleksandra Trościańczyk ◽  
Aneta Nowakiewicz ◽  
Sebastian Gnat ◽  
Dominik Łagowski ◽  
Marcelina Osińska ◽  
...  

Introduction. The possible transfer of antimicrobial resistance genes between Enterococcus faecium isolates from humans and different animal species, including those not covered by monitoring programs (e.g. pet and wildlife), poses a serious threat to public health. Hypothesis/Gap Statement. Little is known about occurrence and mechanisms of phenomenon of multidrug resistance of E. faecium isolated from various host species in Poland. Aim. The aim of the study was to characterize multidrug-resistant E. faecium isolated from humans and animals (livestock, pets and wildlife) in terms of the occurrence of genetic markers determining resistance. Methodology. Bacterial isolates were tested for phenotypic resistance and the presence of genes encoding resistance to macrolides, tetracycline, aminoglycosides, aminocyclitols and phenicols as well as efflux pump (emeA), resolvase (tndX) and integrase (Int-Tn) genes. The quinolone resistance-determining regions of gyrA and parC were sequenced. Results. Human isolates of E. faecium were characterized by high-level resistance to: ciprofloxacin, enrofloxacin, erythromycin (100 %), as well, as aminoglycosides resistance (kanamycin – 100%, streptomycin – 78 %, gentamicin – 78%). Regardless of the animal species, high level of resistance of E. faecium to tetracycline (from 88–100 %), erythromycin (from 82–94 %) and kanamycin (from 36–100 %) was observed. All E. faecium isolates from wildlife were resistant to fluoroquinolones. However, full susceptibility to vancomycin was observed in all isolates tested. Phenotypic antimicrobial resistance of E. faecium was identified in the presence of the following resistance genes: erm(B) (70%), msr(A) (50 %), tet(L) (35 %), tet(K) (34 %), tet(M) (76 %), aac(6’)-Ie-aph(2″)-Ia (25%), ant(6)-Ia (31%), aph(3)-IIIa (68 %), (tndX) (23 %), and integrase gene (Int-Tn) (34 %). A correlation between an amino acid substitution at positions 83 and 87 of gyrA and position 80 of parC and the high-level fluoroquinolone resistance in E. faecium has been observed as well. Conclusion. The level and range of antimicrobial resistance and the panel of resistance determinants is comparable between E. faecium isolates, despite host species.


2013 ◽  
Vol 79 (13) ◽  
pp. 4170-4172 ◽  
Author(s):  
A. Cabal ◽  
S. Gómez-Barrero ◽  
C. Porrero ◽  
C. Bárcena ◽  
G. López ◽  
...  

ABSTRACTThe distribution of virulence factors (VFs) typical of diarrheagenicEscherichia coliand the antimicrobial resistance (AMR) profiles were assessed in 780 isolates from healthy pigs, broilers, and cattle from Spain. VF distribution was broader than expected, although at low prevalence for most genes, with AMR being linked mainly to host species.


2011 ◽  
Vol 77 (23) ◽  
pp. 8400-8408 ◽  
Author(s):  
Rebecca E. Symula ◽  
Ian Marpuri ◽  
Robert D. Bjornson ◽  
Loyce Okedi ◽  
Jon Beadell ◽  
...  

ABSTRACTVertical transmission of obligate symbionts generates a predictable evolutionary history of symbionts that reflects that of their hosts. In insects, evolutionary associations between symbionts and their hosts have been investigated primarily among species, leaving population-level processes largely unknown. In this study, we investigated the tsetse (Diptera: Glossinidae) bacterial symbiont,Wigglesworthia glossinidia, to determine whether observed codiversification of symbiont and tsetse host species extends to a single host species (Glossina fuscipes fuscipes) in Uganda. To explore symbiont genetic variation inG. f. fuscipespopulations, we screened two variable loci (lonandlepA) from theWigglesworthia glossinidiabacterium in the host speciesGlossina fuscipes fuscipes(W. g. fuscipes) and examined phylogeographic and demographic characteristics in multiple host populations. Symbiont genetic variation was apparent within and among populations. We identified two distinct symbiont lineages, in northern and southern Uganda. Incongruence length difference (ILD) tests indicated that the two lineages corresponded exactly to northern and southernG. f. fuscipesmitochondrial DNA (mtDNA) haplogroups (P= 1.0). Analysis of molecular variance (AMOVA) confirmed that most variation was partitioned between the northern and southern lineages defined by host mtDNA (85.44%). However, ILD tests rejected finer-scale congruence within the northern and southern populations (P= 0.009). This incongruence was potentially due to incomplete lineage sorting that resulted in novel combinations of symbiont genetic variants and host background. Identifying these novel combinations may have public health significance, since tsetse is the sole vector of sleeping sickness andWigglesworthiais known to influence host vector competence. Thus, understanding the adaptive value of these host-symbiont combinations may afford opportunities to develop vector control methods.


2020 ◽  
Vol 6 (9) ◽  
Author(s):  
Ebenezer Foster-Nyarko ◽  
Nabil-Fareed Alikhan ◽  
Anuradha Ravi ◽  
Gaëtan Thilliez ◽  
Nicholas M. Thomson ◽  
...  

Increasing contact between humans and non-human primates provides an opportunity for the transfer of potential pathogens or antimicrobial resistance between host species. We have investigated genomic diversity and antimicrobial resistance in Escherichia coli isolates from four species of non-human primates in the Gambia: Papio papio (n=22), Chlorocebus sabaeus (n=14), Piliocolobus badius (n=6) and Erythrocebus patas (n=1). We performed Illumina whole-genome sequencing on 101 isolates from 43 stools, followed by nanopore long-read sequencing on 11 isolates. We identified 43 sequence types (STs) by the Achtman scheme (ten of which are novel), spanning five of the eight known phylogroups of E. coli . The majority of simian isolates belong to phylogroup B2 – characterized by strains that cause human extraintestinal infections – and encode factors associated with extraintestinal disease. A subset of the B2 strains (ST73, ST681 and ST127) carry the pks genomic island, which encodes colibactin, a genotoxin associated with colorectal cancer. We found little antimicrobial resistance and only one example of multi-drug resistance among the simian isolates. Hierarchical clustering showed that simian isolates from ST442 and ST349 are closely related to isolates recovered from human clinical cases (differences in 50 and 7 alleles, respectively), suggesting recent exchange between the two host species. Conversely, simian isolates from ST73, ST681 and ST127 were distinct from human isolates, while five simian isolates belong to unique core-genome ST complexes – indicating novel diversity specific to the primate niche. Our results are of planetary health importance, considering the increasing contact between humans and wild non-human primates.


2020 ◽  
Vol 140 (1) ◽  
Author(s):  
Chiara Turchi ◽  
Filomena Melchionda ◽  
Mauro Pesaresi ◽  
Eleonora Ciarimboli ◽  
Carla Bini ◽  
...  

2021 ◽  
Vol 19 (1) ◽  
Author(s):  
Karin Wallander ◽  
Jessada Thutkawkorapin ◽  
Ellika Sahlin ◽  
Annika Lindblom ◽  
Kristina Lagerstedt-Robinson

Abstract Background We have previously reported a family with a suspected autosomal dominant rectal and gastric cancer syndrome without any obvious causative genetic variant. Here, we focused the study on a potentially isolated rectal cancer syndrome in this family. Methods We included seven family members (six obligate carriers). Whole-exome sequencing and whole-genome sequencing data were analyzed and filtered for shared coding and splicing sequence and structural variants among the affected individuals. Results When considering family members with rectal cancer or advanced adenomas as affected, we found six new potentially cancer-associated variants in the genes CENPB, ZBTB20, CLINK, LRRC26, TRPM1, and NPEPL1. All variants were missense variants and none of the genes have previously been linked to inherited rectal cancer. No structural variant was found. Conclusion By massive parallel sequencing in a family suspected of carrying a highly penetrant rectal cancer predisposing genetic variant, we found six genetic missense variants with a potential connection to the rectal cancer in this family. One of them could be a high-risk genetic variant, or one or more of them could be low risk variants. The p.(Glu438Lys) variant in the CENPB gene was found to be of particular interest. The CENPB protein binds DNA and helps form centromeres during mitosis. It is involved in the WNT signaling pathway, which is critical for colorectal cancer development and its role in inherited rectal cancer needs to be further examined.


Rechtsmedizin ◽  
2021 ◽  
Author(s):  
Jana Naue ◽  
Julia Winkelmann ◽  
Ulrike Schmidt ◽  
Sabine Lutz-Bonengel

AbstractThe analysis of age-dependent DNA methylation changes is a valuable tool in epigenetic research and forensic genetics. With some exceptions, most studies in the past concentrated on the analysis of blood, buccal, and saliva samples. Another important sample type in forensic investigations is hair, where age-dependent DNA methylation has not been investigated so far. In this pilot study a deeper look was taken at the possibilities and challenges of DNA methylation analysis in hair. The DNA methylation of selected age-dependent 5’-C-phosphate-G‑3’ (CpG) sites were characterized for their potential use as a biomarker for age prediction using plucked hair samples and massive parallel sequencing. Plucked hair roots of 49 individuals were included in the study. The DNA methylation of 31 hairs was successfully analyzed. The DNA methylation pattern of 10 loci, including ELOVL2, F5, KLF14, and TRIM59, was determined by amplicon-based massive parallel sequencing. Age-dependent changes were found for several markers. The results demonstrate the possible use of already established age-dependent markers but at the same time they have tissue/cell type-specific characteristics. Special challenges such as low amounts of DNA and degraded DNA as well as the possible heterogeneous cellular composition of plucked hair samples, have to be considered.


1993 ◽  
Vol 79 (5) ◽  
pp. 729-735 ◽  
Author(s):  
David Barba ◽  
Joseph Hardin ◽  
Jasodhara Ray ◽  
Fred H. Gage

✓ Gene therapy has many potential applications in central nervous system (CNS) disorders, including the selective killing of tumor cells in the brain. A rat brain tumor model was used to test the herpes simplex virus (HSV)-thymidine kinase (TK) gene for its ability to selectively kill C6 and 9L tumor cells in the brain following systemic administration of the nucleoside analog ganciclovir. The HSV-TK gene was introduced in vitro into tumor cells (C6-TK and 9L-TK), then these modified tumor cells were evaluated for their sensitivity to cell killing by ganciclovir. In a dose-response assay, both C6-TK and 9L-TK cells were 100 times more sensitive to killing by ganciclovir (median lethal dose: C6-TK, 0.1 µg ganciclovir/ml; C6, 5.0 µg ganciclovir/ml) than unmodified wild-type tumor cells or cultured fibroblasts. In vivo studies confirmed the ability of intraperitoneal ganciclovir administration to kill established brain tumors in rats as quantified by both stereological assessment of brain tumor volumes and studies of animal survival over 90 days. Rats with brain tumors established by intracerebral injection of wild-type or HSV-TK modified tumor cells or by a combination of wild-type and HSV-TK-modified cells were studied with and without ganciclovir treatments. Stereological methods determined that ganciclovir treatment eliminated tumors composed of HSV-TK-modified cells while control tumors grew as expected (p < 0.001). In survival studies, all 10 rats with 9L-TK tumors treated with ganciclovir survived 90 days while all untreated rats died within 25 days. Curiously, tumors composed of combinations of 9L and 9L-TK cells could be eliminated by ganciclovir treatments even when only one-half of the tumor cells carried the HSV-TK gene. While not completely understood, this additional tumor cell killing appears to be both tumor selective and local in nature. It is concluded that HSV-TK gene therapy with ganciclovir treatment does selectively kill tumor cells in the brain and has many potential applications in CNS disorders, including the treatment of cancer.


Sign in / Sign up

Export Citation Format

Share Document