scholarly journals The High Prevalence and Diversity of Chlamydiales DNA within Ixodes ricinus Ticks Suggest a Role for Ticks as Reservoirs and Vectors of Chlamydia-Related Bacteria

2015 ◽  
Vol 81 (23) ◽  
pp. 8177-8182 ◽  
Author(s):  
Ludovic Pilloux ◽  
Sébastien Aeby ◽  
Rahel Gaümann ◽  
Caroline Burri ◽  
Christian Beuret ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Human Pathogens ◽  
Content Type ◽  
The Family ◽  
High Prevalence ◽  
Ixodes Ricinus Ticks ◽  
Medical Importance ◽  
High Level ◽  
Positive Results

ABSTRACTTheChlamydialesorder is composed of nine families of strictly intracellular bacteria. Among them,Chlamydia trachomatis,C. pneumoniae, andC. psittaciare established human pathogens, whereasWaddlia chondrophilaandParachlamydia acanthamoebaehave emerged as new pathogens in humans. However, despite their medical importance, their biodiversity and ecology remain to be studied. Even if arthropods and, particularly, ticks are well known to be vectors of numerous infectious agents such as viruses and bacteria, virtually nothing is known about ticks and chlamydia. This study investigated the prevalence ofChlamydiaein ticks. Specifically, 62,889Ixodes ricinusticks, consolidated into 8,534 pools, were sampled in 172 collection sites throughout Switzerland and were investigated using pan-Chlamydialesquantitative PCR (qPCR) for the presence ofChlamydialesDNA. Among the pools, 543 (6.4%) gave positive results and the estimated prevalence in individual ticks was 0.89%. Among those pools with positive results, we obtained 16S rRNA sequences for 359 samples, allowing classification ofChlamydialesDNA at the family level. A high level of biodiversity was observed, since six of the nine families belonging to theChlamydialesorder were detected. Those most common wereParachlamydiaceae(33.1%) andRhabdochlamydiaceae(29.2%). “UnclassifiedChlamydiales” (31.8%) were also often detected. Thanks to the huge amount ofChlamydialesDNA recovered from ticks, this report opens up new perspectives on further work focusing on whole-genome sequencing to increase our knowledge aboutChlamydialesbiodiversity. This report of an epidemiological study also demonstrates the presence ofChlamydia-related bacteria withinIxodes ricinusticks and suggests a role for ticks in the transmission of and as a reservoir for these emerging pathogenicChlamydia-related bacteria.

scholarly journals Evidence for Inhibition of Topoisomerase 1A by Gold(III) Macrocycles and Chelates TargetingMycobacterium tuberculosisandMycobacterium abscessus

2018 ◽  
Vol 62 (5) ◽  
Author(s):  
Rashmi Gupta ◽  
Carolina Rodrigues Felix ◽  
Matthew P. Akerman ◽  
Kate J. Akerman ◽  
Cathryn A. Slabber ◽  
...  
Keyword(s):  
Mycobacterium Abscessus ◽  
Cross Resistance ◽  
Human Pathogens ◽  
Intrinsic Resistance ◽  
Content Type ◽  
Starting Point ◽  
Scalable Synthesis ◽  
High Level ◽  
Novel Drug

ABSTRACTMycobacterium tuberculosisand the fast-growing speciesMycobacterium abscessusare two important human pathogens causing persistent pulmonary infections that are difficult to cure and require long treatment times. The emergence of drug-resistantM. tuberculosisstrains and the high level of intrinsic resistance ofM. abscessuscall for novel drug scaffolds that effectively target both pathogens. In this study, we evaluated the activity of bis(pyrrolide-imine) gold(III) macrocycles and chelates, originally designed as DNA intercalators capable of targeting human topoisomerase types I and II (Topo1 and Topo2), againstM. abscessusandM. tuberculosis. We identified a total of 5 noncytotoxic compounds active against both mycobacterial pathogens under replicatingin vitroconditions. We chose one of these hits, compound 14, for detailed analysis due to its potent bactericidal mode of inhibition and scalable synthesis. The clinical relevance of this compound was demonstrated by its ability to inhibit a panel of diverseM. tuberculosisandM. abscessusclinical isolates. Prompted by previous data suggesting that compound 14 may target topoisomerase/gyrase enzymes, we demonstrated that it lacked cross-resistance with fluoroquinolones, which target theM. tuberculosisgyrase.In vitroenzyme assays confirmed the potent activity of compound 14 against bacterial topoisomerase 1A (Topo1) enzymes but not gyrase. Novel scaffolds like compound 14 with potent, selective bactericidal activity againstM. tuberculosisandM. abscessusthat act on validated but underexploited targets like Topo1 represent a promising starting point for the development of novel therapeutics for infections by pathogenic mycobacteria.

scholarly journals Mutations ingyrAandgyrBamong Fluoroquinolone- and Multidrug-Resistant Mycobacterium tuberculosis Isolates

2016 ◽  
Vol 60 (4) ◽  
pp. 2090-2096 ◽  
Author(s):  
Jung-Yien Chien ◽  
Wei-Yih Chiu ◽  
Shun-Tien Chien ◽  
Chia-Jung Chiang ◽  
Chong-Jen Yu ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
East Asian ◽  
Multidrug Resistant ◽  
Molecular Techniques ◽  
Content Type ◽  
Low Level ◽  
High Prevalence ◽  
Mdr Tb ◽  
High Level

ABSTRACTIn order to correlate the mutations inside the entiregyrAandgyrBgenes with the level of resistance to ofloxacin (OFX) and moxifloxacin (MFX) in isolates of multidrug-resistantMycobacterium tuberculosis(MDR-TB), a total of 111 isolates were categorized into OFX-susceptible (MIC, ≤2 μg/ml) and low-level (MIC, 4 to 8 μg/ml) and high-level (MIC, ≥16 μg/ml) OFX-resistant isolates and MFX-susceptible (MIC, ≤0.5 μg/ml) and low-level (MIC, 1 to 2 μg/ml) and high-level (MIC, ≥4 μg/ml) MFX-resistant isolates. Resistance-associated mutations inside thegyrAgene were found in 30.2% of OFX-susceptible and 72.5% and 72.2% of low-level and high-level OFX-resistant isolates and in 28.6% of MFX-susceptible and 58.1% and 83.9% of low-level and high-level MFX-resistant isolates. Compared with OFX-susceptible isolates, low-level and high-level OFX-resistant isolates had a significantly higher prevalence of mutations atgyrAcodons 88 to 94 (17.0%, 65.0%, and 72.2%, respectively;P< 0.001) and a higher prevalence of thegyrBG512R mutation (0.0%, 2.5%, and 16.7%, respectively;P= 0.006). Similarly, compared with MFX-susceptible isolates, low-level and high-level MFX-resistant isolates had a significantly higher prevalence of mutations atgyrAcodons 88 to 94 (14.3%, 51.6%, and 80.6%, respectively;P< 0.001) as well as a higher prevalence of thegyrBG512R mutation (0.0%, 0.0%, and 12.9%, respectively;P= 0.011). D94G and D94N mutations ingyrAand the G512R mutation ingyrBwere correlated with high-level MFX resistance, while the D94A mutation was associated with low-level MFX resistance. The prevalence of mutations atgyrAcodons 88 to 94 and thegyrBG512R mutation were higher among fluoroquinolone (FQ)-susceptible East Asian (Beijing) and Indo-Oceanic strains than they were among Euro-American strains, implying that molecular techniques to detect FQ resistance may be less specific in areas with a high prevalence of East Asian (Beijing) and Indo-Oceanic strains.

scholarly journals Novel Insights into the Classification of Staphylococcal β-Lactamases in Relation to the Cefazolin Inoculum Effect

2020 ◽  
Vol 64 (5) ◽  
Author(s):  
Lina P. Carvajal ◽  
Sandra Rincon ◽  
Aura M. Echeverri ◽  
Jessica Porras ◽  
Rafael Rios ◽  
...  
Keyword(s):  
Phylogenetic Analyses ◽  
Sequence Information ◽  
Content Type ◽  
Novel Approach ◽  
Important Concern ◽  
High Prevalence ◽  
Type C ◽  
Inoculum Effect ◽  
Limited Sequence

ABSTRACT Cefazolin has become a prominent therapy for methicillin-susceptible Staphylococcus aureus (MSSA) infections. However, an important concern is the cefazolin inoculum effect (CzIE), a phenomenon mediated by staphylococcal β-lactamases. Four variants of staphylococcal β-lactamases have been described based on serological methodologies and limited sequence information. Here, we sought to reassess the classification of staphylococcal β-lactamases and their correlation with the CzIE. We included a large collection of 690 contemporary bloodstream MSSA isolates recovered from Latin America, a region with a high prevalence of the CzIE. We determined cefazolin MICs at standard and high inoculums by broth microdilution. Whole-genome sequencing was performed to classify the β-lactamase in each isolate based on the predicted full sequence of BlaZ. We used the classical schemes for β-lactamase classification and compared it to BlaZ allotypes found in unique sequences using the genomic information. Phylogenetic analyses were performed based on the BlaZ and core-genome sequences. The overall prevalence of the CzIE was 40%. Among 641 genomes, type C was the most predominant β-lactamase (37%), followed by type A (33%). We found 29 allotypes and 43 different substitutions in BlaZ. A single allotype, designated BlaZ-2, showed a robust and statistically significant association with the CzIE. Two other allotypes (BlaZ-3 and BlaZ-5) were associated with a lack of the CzIE. Three amino acid substitutions (A9V, E112A, and G145E) showed statistically significant association with the CzIE (P = <0.01). CC30 was the predominant clone among isolates displaying the CzIE. Thus, we provide a novel approach to the classification of the staphylococcal β-lactamases with the potential to more accurately identify MSSA strains exhibiting the CzIE.

scholarly journals Interaction of Aeromonas Strains with Lactic Acid Bacteria via Caco-2 Cells

2013 ◽  
Vol 80 (2) ◽  
pp. 681-686 ◽  
Author(s):  
E. Hatje ◽  
C. Neuman ◽  
M. Katouli
Keyword(s):  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Detrimental Effect ◽  
Vero Cells ◽  
Human Pathogens ◽  
Environmental Waters ◽  
Environmental Strain ◽  
Content Type ◽  
Aeromonas Veronii ◽  
Medical Importance

ABSTRACTThe genusAeromonasincludes some species that have now been identified as human pathogens of significant medical importance. We investigated the ability of 13 selectedAeromonasstrains belonging to nine species isolated from clinical cases (n= 5), environmental waters (n= 5), and fish (n= 3) to adhere to and translocate Caco-2 cells in the absence and presence of two lactic acid bacteria (LAB), i.e.,Lactobacillus acidophilusandBifidobacterium breve.Aeromonasisolates were also assessed for their cytotoxicity, the presence of virulence genes, and hemolysin production. Among the clinical isolates, one strain ofAeromonas veroniibiovar veronii and two strains ofAeromonas hydrophilacarried cytotoxin (act), heat-labile toxin (alt), hemolysin (hlyA), and aerolysin (aerA) genes, were cytotoxic to Vero cells, produced hemolysin, and showed higher adherence to Caco-2 cells. In contrast, this was seen in only one environmental strain, a strain ofA. veroniibiovar sobria. WhenAeromonasstrains were coinoculated with LAB onto Caco-2 cells, their level of adhesion was reduced. However, their rate of translocation in the presence of LAB increased and was significantly (P< 0.05) higher among fish strains. We suggest that either the interaction betweenAeromonasand LAB strains could have a detrimental effect on the Caco-2 cells, allowing theAeromonasto translocate more readily, or the presence of the LAB stimulated theAeromonasstrains to produce more toxins and/or increase their translocation rate.

scholarly journals High Prevalence and Predominance of the aph(2″)-If Gene Conferring Aminoglycoside Resistance in Campylobacter

2017 ◽  
Vol 61 (5) ◽  
Author(s):  
Hong Yao ◽  
Dejun Liu ◽  
Yang Wang ◽  
Qijing Zhang ◽  
Zhangqi Shen
Keyword(s):  
Horizontal Transmission ◽  
Foodborne Pathogen ◽  
Systemic Infection ◽  
Campylobacter Coli ◽  
Aminoglycoside Resistance ◽  
Content Type ◽  
High Prevalence ◽  
Gentamicin Resistance ◽  
Long Range Pcr ◽  
High Level

ABSTRACT Campylobacter is a major foodborne pathogen, and previous studies revealed that Campylobacter isolates from food-producing animals are increasingly resistant to gentamicin in China. The molecular epidemiology and genetic mechanisms responsible for gentamicin resistance in China have not been well understood. In this study, 607 Campylobacter isolates of chicken and swine origins collected in 2014 were analyzed, revealing that 15.6% (25/160) of the Campylobacter jejuni isolates and 79.9% (357/447) of the Campylobacter coli isolates were resistant to gentamicin. PCR detection of the gentamicin resistance genes indicated that aph(2″)-If was more prevalent than the previously identified aacA/aphD gene and has become the dominant gentamicin resistance determinant in Campylobacter. Transformation and whole-genome sequencing as well as long-range PCR discovered that aph(2″)-If was located on a chromosomal segment inserted between two conserved genes, Cj0299 and panB. Cloning of aph(2″)-If into gentamicin-susceptible C. jejuni NCTC 11168 confirmed its function in conferring high-level resistance to gentamicin and kanamycin. Molecular typing by pulsed-field gel electrophoresis suggested that both regional expansion of a particular clone and horizontal transmission were involved in the dissemination of the aph(2″)-If gene in Campylobacter. To our knowledge, this is the first report describing the high prevalence of a chromosomally encoded aph(2″)-If gene in Campylobacter. The high prevalence and predominance of this gene might be driven by the use of aminoglycoside antibiotics in food animal production in China and potentially compromise the usefulness of gentamicin as a therapeutic agent for Campylobacter-associated systemic infection.

Simultaneous instance and feature selection for improving prediction in special education data

2017 ◽  
Vol 51 (3) ◽  
pp. 278-297 ◽  
Author(s):  
Yenny Villuendas-Rey ◽  
Carmen Rey-Benguría ◽  
Miltiadis Lytras ◽  
Cornelio Yáñez-Márquez ◽  
Oscar Camacho-Nieto
Keyword(s):  
Feature Selection ◽  
Data Sets ◽  
Feature Selection Technique ◽  
Similarity Functions ◽  
Content Type ◽  
Education Data ◽  
Multiple Feature ◽  
The Family ◽  
Selection For

Purpose The purpose of this paper is to improve the classification of families having children with affective-behavioral maladies, and thus giving the families a suitable orientation. Design/methodology/approach The proposed methodology includes three steps. Step 1 addresses initial data preprocessing, by noise filtering or data condensation. Step 2 performs a multiple feature sets selection, by using genetic algorithms and rough sets. Finally, Step 3 merges the candidate solutions and obtains the selected features and instances. Findings The new proposal show very good results on the family data (with 100 percent of correct classifications). It also obtained accurate results over a variety of repository data sets. The proposed approach is suitable for dealing with non-symmetric similarity functions, as well as with high-dimensionality mixed and incomplete data. Originality/value Previous work in the state of the art only considers instance selection to preprocess the schools for children with affective-behavioral maladies data. This paper explores using a new combined instance and feature selection technique to select relevant instances and features, leading to better classification, and to a simplification of the data.

scholarly journals Phylogenetic Analysis of the Species Theilovirus: Emerging Murine and Human Pathogens

2008 ◽  
Vol 82 (23) ◽  
pp. 11545-11554 ◽  
Author(s):  
Zhiguo Liang ◽  
A. S. Manoj Kumar ◽  
Morris S. Jones ◽  
Nick J. Knowles ◽  
Howard L. Lipton
Keyword(s):  
Phylogenetic Analysis ◽  
Phylogenetic Analyses ◽  
Distinct Species ◽  
Encephalomyocarditis Virus ◽  
Gene Products ◽  
Human Pathogens ◽  
Central Nervous System Infections ◽  
The Family ◽  
Encephalomyelitis Virus

ABSTRACT The Cardiovirus genus of the family Picornaviridae includes two distinct species, Encephalomyocarditis virus and Theilovirus. We now report the complete nucleotide sequences of three Theiler's murine encephalomyelitis virus (TMEV) strains (TO Yale, TOB15, and Vie 415HTR) and of Vilyuisk human encephalomyelitis virus (VHEV). This information, together with the recently reported sequences of divergent theiloviruses (Theiler's-like rat virus [TRV] and Saffold viruses 1 and 2 [SAFV-1 and SAFV-2]), enables an updated phylogenetic analysis as well as a reexamination of several gene products important in the pathogenesis of this emerging group of viruses. In the light of the known neurotropism of TMEV and the new human SAFV-1 and SAFV-2, the resulting data suggest the existence of theiloviruses that cause human central nervous system infections. Our phylogenetic analyses point to the classification of presently known theiloviruses into five types: TMEV, VHEV, TRV, SAFV-1, and SAFV-2.

Neurosurgical desmoid tumors

1979 ◽  
Vol 50 (6) ◽  
pp. 725-732 ◽  
Author(s):  
Reinhard L. Friede ◽  
Anita Pollak
Keyword(s):  
Fine Structure ◽  
The Other ◽  
Differential Diagnoses ◽  
Desmoid Tumors ◽  
Content Type ◽  
The Family ◽  
Fine Print

✓ Four neurosurgical tumors of desmoid appearance are presented, along with a brief review of the differential diagnoses of intracranial or spinal fibromatous or desmoid lesions. Two of the tumors were identified as extremely collagenized meningiomas by their typical fine structure. The classification of the other two tumors remains uncertain, but they were thought to belong to the family of desmoid tumors.

scholarly journals Environmental determinants of the occurrence and activity of Ixodes ricinus ticks and the prevalence of tick-borne diseases in eastern Poland

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Zbigniew Zając ◽  
Joanna Kulisz ◽  
Katarzyna Bartosik ◽  
Aneta Woźniak ◽  
Malwina Dzierżak ◽  
...  
Keyword(s):  
Ixodes Ricinus ◽  
Tick Species ◽  
Forest Cover ◽  
Common Species ◽  
Environmental Determinants ◽  
Tick Borne Encephalitis ◽  
High Incidence ◽  
Ixodes Ricinus Ticks ◽  
Medical Importance ◽  
Tick Borne Encephalitis Virus

AbstractIxodes ricinus is the most widely distributed tick species in Europe. Mainly deciduous and mixed forests, pastures, and urban parks are habitats preferred by this species. I. ricinus ticks are also one of the most important reservoirs and vectors of human and animal infectious diseases on the continent. Borrelia burgdorferi s.l. spirochetes causing Lyme borreliosis (LB) in humans and tick borne encephalitis virus (TBEV), which is a causative agent of tick-borne encephalitis (TBE), are pathogens with the highest medical importance transmitted by this species. Investigations of the environmental determinants of the occurrence and activity of I. ricinus are crucial for elucidation of the environmental background of tick-borne diseases. In eastern Poland, I. ricinus is a common species with peak activity recorded in May in the entire region. During this period, 49 females, 32 males, and 55 I. ricinus nymphs were collected from an area of 900 m2. The results of the present study show that the occurrence and seasonal activity of this tick species are mainly influenced by microhabitat conditions, and saturation deficit has a significant effect on the activity of the species. Eastern Poland is characterized by a high incidence of LB and TBE. We have shown a correlation between the forest cover and the number of reported cases of tick-borne diseases.

scholarly journals Reclassification of genus Izhakiella into the family Erwiniaceae based on phylogenetic and genomic analyses

2020 ◽  
Vol 70 (5) ◽  
pp. 3541-3546 ◽  
Author(s):  
Lingmin Jiang ◽  
Dexin Wang ◽  
Ji-Sun Kim ◽  
Ju Huck Lee ◽  
Dae-Hyuk Kim ◽  
...  
Keyword(s):  
Type Species ◽  
Housekeeping Gene ◽  
Rrna Gene ◽  
Content Type ◽  
Link Type ◽  
Conserved Signature Indels ◽  
The Family ◽  
Taxonomical Classification ◽  
Core Genes

The genus Izhakiella was established and designated as a member of the family Enterobacteriaceae in 2016. Although the taxonomical classification of most members in this family has been relatively resolved after two reclassifications in 2016 and 2017, the classification of the genus Izhakiella remains ambiguous. In this study, a polyphasic approach was used to provide evidence supporting the fact that the genus Izhakiella should no longer be considered a member of Enterobacteriaceae and proposes its reclassification into the family Erwiniaceae . The phylogenetic tree of type species in the families Enterobacteriaceae and Erwiniaceae based on the sequences of the 16S rRNA gene, rpoB housekeeping gene, and the whole-genome comprising the 92 core genes revealed that the genus Izhakiella forms a phylogenetic lineage within the family Erwiniaceae . The average nucleotide identity (ANI) value of the type species with genus Izhakiella was found to be higher for the family Erwiniaceae than that for the family Enterobacteriaceae . Notably, 12 conserved signature indels (CSIs) that are exclusively shared among the Erwiniaceae clade members were found in the type strains of the genus Izhakiella . Based on these analyses, this study suggests the reclassification of I. capsodis and I. australiensis into the family Erwiniaceae .

Sign in / Sign up

Export Citation Format

Share Document