scholarly journals Addicted? Reduced host resistance in populations with defensive symbionts

2016 ◽  
Vol 283 (1833) ◽  
pp. 20160778 ◽  
Author(s):  
Julien Martinez ◽  
Rodrigo Cogni ◽  
Chuan Cao ◽  
Sophie Smith ◽  
Christopher J. R. Illingworth ◽  
...  
Keyword(s):  
Drosophila Melanogaster ◽  
Insect Resistance ◽  
Resistance Genes ◽  
Host Resistance ◽  
Major Effect ◽  
Insect Host ◽  
Insect Genome ◽  
Resistant Allele ◽  
Wide Range ◽  
Evolution Of Resistance

Heritable symbionts that protect their hosts from pathogens have been described in a wide range of insect species. By reducing the incidence or severity of infection, these symbionts have the potential to reduce the strength of selection on genes in the insect genome that increase resistance. Therefore, the presence of such symbionts may slow down the evolution of resistance. Here we investigated this idea by exposing Drosophila melanogaster populations to infection with the pathogenic Drosophila C virus (DCV) in the presence or absence of Wolbachia , a heritable symbiont of arthropods that confers protection against viruses. After nine generations of selection, we found that resistance to DCV had increased in all populations. However, in the presence of Wolbachia the resistant allele of pastrel —a gene that has a major effect on resistance to DCV—was at a lower frequency than in the symbiont-free populations. This finding suggests that defensive symbionts have the potential to hamper the evolution of insect resistance genes, potentially leading to a state of evolutionary addiction where the genetically susceptible insect host mostly relies on its symbiont to fight pathogens.

scholarly journals High Temperature Enhances the Resistance of Cultivated African Rice, Oryza glaberrima, to Bacterial Blight

Plant Disease ◽  
2016 ◽  
Vol 100 (2) ◽  
pp. 380-387 ◽  
Author(s):  
Gerbert Sylvestre Dossa ◽  
Ricardo Oliva ◽  
Edgar Maiss ◽  
Casiana Vera Cruz ◽  
Kerstin Wydra
Keyword(s):  
High Temperature ◽  
Resistance Genes ◽  
Broad Spectrum ◽  
Host Resistance ◽  
Bacterial Blight ◽  
The Philippines ◽  
Oryza Glaberrima ◽  
Pathogen Invasion ◽  
Broad Spectrum Resistance ◽  
Wide Range

Rice bacterial blight (BB) is caused by Xanthomonas oryzae pv. oryzae and is responsible for substantial yield loss worldwide. Host resistance remains the most feasible control measure. However, pathogen variability leads to the failure of certain resistance genes to control the disease, and climate change with high amplitudes of heat predisposes the host plant to pathogen invasion. Due to pressure in natural selection, landrace species often carry a wide range of unique traits conferring tolerance of stress. Therefore, exploring their genetic background for host resistance could enable the identification of broad-spectrum resistance to combined abiotic and biotic stresses. Nineteen Oryza glaberrima accessions and O. sativa rice variety SUPA were evaluated for BB resistance under high temperature (35 and 31°C day and night, respectively) using 14 X. oryzae pv. oryzae strains originated from the Philippines. Under normal temperature, most of the accessions showed resistance to 9 strains (64.3%) and accession TOG6007 showed broad-spectrum resistance to 12 strains (85.7%). Under high temperature, most accessions showed a reduction in BB disease, whereas, accession TOG5620 showed disease reduction from all the X. oryzae pv. oryzae strains under high temperature. Molecular characterization using gene-based and linked markers for BB resistance genes Xa4, xa5, Xa7, xa13, and Xa21 revealed the susceptible alleles of Xa4, xa5, xa13, and Xa21 in O. glaberrima. However, no allele of Xa7 was detected among O. glaberrima accessions. Our results suggest that O. glaberrima accessions contain a BB resistance different from the Xa gene type. Genome-wide association mapping could be used to identify quantitative trait loci that are associated with BB resistance or combined BB resistance and high-temperature tolerance.

scholarly journals Whole genome-based characterisation of antimicrobial resistance and genetic diversity in Campylobacter jejuni and Campylobacter coli from ruminants

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Medelin Ocejo ◽  
Beatriz Oporto ◽  
José Luis Lavín ◽  
Ana Hurtado
Keyword(s):  
Genetic Diversity ◽  
Antimicrobial Resistance ◽  
Campylobacter Jejuni ◽  
Resistance Genes ◽  
Campylobacter Coli ◽  
Whole Genome ◽  
Northern Spain ◽  
Sequence Alignments ◽  
Phenotypic Data ◽  
Wide Range

AbstractCampylobacter, a leading cause of gastroenteritis in humans, asymptomatically colonises the intestinal tract of a wide range of animals.Although antimicrobial treatment is restricted to severe cases, the increase of antimicrobial resistance (AMR) is a concern. Considering the significant contribution of ruminants as reservoirs of resistant Campylobacter, Illumina whole-genome sequencing was used to characterise the mechanisms of AMR in Campylobacter jejuni and Campylobacter coli recovered from beef cattle, dairy cattle, and sheep in northern Spain. Genome analysis showed extensive genetic diversity that clearly separated both species. Resistance genotypes were identified by screening assembled sequences with BLASTn and ABRicate, and additional sequence alignments were performed to search for frameshift mutations and gene modifications. A high correlation was observed between phenotypic resistance to a given antimicrobial and the presence of the corresponding known resistance genes. Detailed sequence analysis allowed us to detect the recently described mosaic tet(O/M/O) gene in one C. coli, describe possible new alleles of blaOXA-61-like genes, and decipher the genetic context of aminoglycoside resistance genes, as well as the plasmid/chromosomal location of the different AMR genes and their implication for resistance spread. Updated resistance gene databases and detailed analysis of the matched open reading frames are needed to avoid errors when using WGS-based analysis pipelines for AMR detection in the absence of phenotypic data.

scholarly journals Risk factors for severity on admission and the disease progression during hospitalisation in a large cohort of patients with COVID-19 in Japan

BMJ Open ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. e047007
Author(s):  
Mari Terada ◽  
Hiroshi Ohtsu ◽  
Sho Saito ◽  
Kayoko Hayakawa ◽  
Shinya Tsuzuki ◽  
...  
Keyword(s):  
Risk Factors ◽  
Mechanical Ventilation ◽  
Chronic Respiratory Disease ◽  
Major Effect ◽  
Secondary Outcome ◽  
Healthcare Facilities ◽  
Wide Range ◽  
Registration Number ◽  
Using Data ◽  
Obesity Hypertension

ObjectivesTo investigate the risk factors contributing to severity on admission. Additionally, risk factors of worst severity and fatality were studied. Moreover, factors were compared based on three points: early severity, worst severity and fatality.DesignAn observational cohort study using data entered in a Japan nationwide COVID-19 inpatient registry, COVIREGI-JP.SettingAs of 28 September 2020, 10480 cases from 802 facilities have been registered. Participating facilities cover a wide range of hospitals where patients with COVID-19 are admitted in Japan.ParticipantsParticipants who had a positive test result on any applicable SARS-CoV-2 diagnostic tests were admitted to participating healthcare facilities. A total of 3829 cases were identified from 16 January to 31 May 2020, of which 3376 cases were included in this study.Primary and secondary outcome measuresPrimary outcome was severe or nonsevere on admission, determined by the requirement of mechanical ventilation or oxygen therapy, SpO2 or respiratory rate. Secondary outcome was the worst severity during hospitalisation, judged by the requirement of oxygen and/orinvasive mechanical ventilation/extracorporeal membrane oxygenation.ResultsRisk factors for severity on admission were older age, men, cardiovascular disease, chronic respiratory disease, diabetes, obesity and hypertension. Cerebrovascular disease, liver disease, renal disease or dialysis, solid tumour and hyperlipidaemia did not influence severity on admission; however, it influenced worst severity. Fatality rates for obesity, hypertension and hyperlipidaemia were relatively lower.ConclusionsThis study segregated the comorbidities influencing severity and death. It is possible that risk factors for severity on admission, worst severity and fatality are not consistent and may be propelled by different factors. Specifically, while hypertension, hyperlipidaemia and obesity had major effect on worst severity, their impact was mild on fatality in the Japanese population. Some studies contradict our results; therefore, detailed analyses, considering in-hospital treatments, are needed for validation.Trial registration numberUMIN000039873. https://upload.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000045453

scholarly journals 322. Evaluation of the BioFire® Bone and Joint Infection (BJI) Panel for the Detection of Microorganisms and Antimicrobial Resistance Genes in Synovial Fluid Specimens

2020 ◽  
Vol 7 (Supplement_1) ◽  
pp. S233-S234
Author(s):  
Corrin Graue ◽  
Bryan H Schmitt ◽  
Amy Waggoner ◽  
Frederic Laurent ◽  
Lelia Abad ◽  
...  
Keyword(s):  
Antimicrobial Resistance ◽  
Synovial Fluid ◽  
Resistance Genes ◽  
Clinical Care ◽  
Joint Infection ◽  
High Morbidity ◽  
Bone And Joint Infection ◽  
Microbiological Methods ◽  
Antimicrobial Resistance Genes ◽  
Wide Range

Abstract Background Bone and Joint Infections (BJIs) present with non-specific symptoms that may include pain, swelling, and fever and are associated with high morbidity and significant risk of mortality. BJIs can be caused by a variety of bacteria and fungi, including anaerobes and microorganisms that can be challenging to culture or identify by traditional microbiological methods. Clinicians primarily rely on culture to identify the pathogen(s) responsible for infection. The BioFire® Bone and Joint Infection (BJI) Panel (BioFire Diagnostics, Salt Lake City, UT) is designed to detect 15 gram-positive bacteria (including seven anaerobes), 14 gram-negative bacteria (including one anaerobe), two yeast, and eight antimicrobial resistance (AMR) genes from synovial fluid specimens in about an hour. The objective of this study was to evaluate the performance of an Investigational Use Only (IUO) version of the BioFire BJI Panel compared to various reference methods. Methods Remnant synovial fluid specimens, which were collected for routine clinical care at 13 study sites in the US and Europe, underwent testing using an IUO version of the BioFire BJI Panel. Performance of this test was determined by comparison to Standard of Care (SoC) consisting of bacterial culture performed at each study site according to their routine procedures. Results A total of 1544 synovial fluid specimens were collected and tested with the BioFire BJI Panel. The majority of specimens were from knee joints (77.9%) and arthrocentesis (79.4%) was the most common collection method. Compared to SoC culture, overall sensitivity was 90.2% and specificity was 99.8%. The BioFire BJI Panel yielded a total of 268 Detected results, whereas SoC yielded a total of 215 positive results for on-panel analytes. Conclusion The BioFire BJI Panel is a sensitive, specific, and robust test for rapid detection of a wide range of analytes in synovial fluid specimens. The number of microorganisms and resistance genes included in the BioFire BJI Panel, together with a reduced time-to-result and increased diagnostic yield compared to culture, is expected to aid in the timely diagnosis and appropriate management of BJIs. Disclosures Benjamin von Bredow, PhD, BioFire (Grant/Research Support) Jennifer Dien Bard, PhD, BioFire Diagnostic (Consultant, Scientific Research Study Investigator) Bart Kensinger, PhD, BioFire Diagnostics (Employee) Benedicte Pons, PhD, bioMerieux SA (Employee) Corinne Jay, PhD, bioMerieux SA (Employee)

scholarly journals Bacterial Communities Differ among Drosophila melanogaster Populations and Affect Host Resistance against Parasitoids

PLoS ONE ◽  
2016 ◽  
Vol 11 (12) ◽  
pp. e0167726 ◽  
Author(s):  
Mariia Chaplinska ◽  
Sylvia Gerritsma ◽  
Francisco Dini-Andreote ◽  
Joana Falcao Salles ◽  
Bregje Wertheim
Keyword(s):  
Drosophila Melanogaster ◽  
Host Resistance ◽  
Bacterial Communities

scholarly journals Multi-omic surveillance of Escherichia coli and Klebsiella spp. in hospital sink drains and patients

2020 ◽  
Author(s):  
B Constantinides ◽  
KK Chau ◽  
TP Quan ◽  
G Rodger ◽  
M Andersson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antimicrobial Resistance ◽  
Resistance Genes ◽  
Bacterial Infections ◽  
Wide Spectrum ◽  
Klebsiella Oxytoca ◽  
Clinical Disease ◽  
E Coli ◽  
Antimicrobial Resistance Genes ◽  
Wide Range

ABSTRACTEscherichia coli and Klebsiella spp. are important human pathogens that cause a wide spectrum of clinical disease. In healthcare settings, sinks and other wastewater sites have been shown to be reservoirs of antimicrobial-resistant E. coli and Klebsiella spp., particularly in the context of outbreaks of resistant strains amongst patients. Without focusing exclusively on resistance markers or a clinical outbreak, we demonstrate that many hospital sink drains are abundantly and persistently colonised with diverse populations of E. coli, Klebsiella pneumoniae and Klebsiella oxytoca, including both antimicrobial-resistant and susceptible strains. Using whole genome sequencing (WGS) of 439 isolates, we show that environmental bacterial populations are largely structured by ward and sink, with only a handful of lineages, such as E. coli ST635, being widely distributed, suggesting different prevailing ecologies which may vary as a result of different inputs and selection pressures. WGS of 46 contemporaneous patient isolates identified one (2%; 95% CI 0.05-11%) E. coli urine infection-associated isolate with high similarity to a prior sink isolate, suggesting that sinks may contribute to up to 10% of infections caused by these organisms in patients on the ward over the same timeframe. Using metagenomics from 20 sink-timepoints, we show that sinks also harbour many clinically relevant antimicrobial resistance genes including blaCTX-M, blaSHV and mcr, and may act as niches for the exchange and amplification of these genes. Our study reinforces the potential role of sinks in contributing to Enterobacterales infection and antimicrobial resistance in hospital patients, something that could be amenable to intervention.IMPORTANCEEscherichia coli and Klebsiella spp. cause a wide range of bacterial infections, including bloodstream, urine and lung infections. Previous studies have shown that sink drains in hospitals may be part of transmission chains in outbreaks of antimicrobial-resistant E. coli and Klebsiella spp., leading to colonisation and clinical disease in patients. We show that even in non-outbreak settings, contamination of sink drains by these bacteria is common across hospital wards, and that many antimicrobial resistance genes can be found and potentially exchanged in these sink drain sites. Our findings demonstrate that the colonisation of handwashing sink drains by these bacteria in hospitals is likely contributing to some infections in patients, and that additional work is needed to further quantify this risk, and to consider appropriate mitigating interventions.

scholarly journals Genome Sequence of a Recently Emerged, Highly Transmissible, Multi-Antibiotic- and Antiseptic-Resistant Variant of Methicillin-Resistant Staphylococcus aureus, Sequence Type 239 (TW)

2009 ◽  
Vol 192 (3) ◽  
pp. 888-892 ◽  
Author(s):  
Matthew T. G. Holden ◽  
Jodi A. Lindsay ◽  
Craig Corton ◽  
Michael A. Quail ◽  
Joshua D. Cockfield ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Staphylococcus Aureus ◽  
Genome Sequence ◽  
Resistance Genes ◽  
Methicillin Resistant Staphylococcus Aureus ◽  
Housekeeping Genes ◽  
Sequence Type ◽  
Resistant Variant ◽  
Methicillin Resistant ◽  
Wide Range

ABSTRACT The 3.1-Mb genome of an outbreak methicillin-resistant Staphylococcus aureus (MRSA) strain (TW20) contains evidence of recently acquired DNA, including two large regions (635 kb and 127 kb). The strain is resistant to a wide range of antibiotics, antiseptics, and heavy metals due to resistance genes encoded on mobile genetic elements and also mutations in housekeeping genes.

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