183 research outputs found
Context-dependent costs and benefits of tuberculosis resistance traits in a wild mammalian host
Disease acts as a powerful driver of evolution in natural host populations, yet individuals in a population often vary in their susceptibility to infection. Energetic trade-offs between immune and reproductive investment lead to the evolution of distinct life history strategies, driven by the relative fitness costs and benefits of resisting infection. However, examples quantifying the cost of resistance outside of the laboratory are rare. Here, we observe two distinct forms of resistance to bovine tuberculosis (bTB), an important zoonotic pathogen, in a free-ranging African buffalo (Syncerus caffer) population. We characterize these phenotypes as âinfection resistance,â in which hosts delay or prevent infection, and âproliferation resistance,â in which the host limits the spread of lesions caused by the pathogen after infection has occurred. We found weak evidence that infection resistance to bTB may be heritable in this buffalo population (h2 = 0.10) and comes at the cost of reduced body condition and marginally reduced survival once infected, but also associates with an overall higher reproductive rate. Infection-resistant animals thus appear to follow a âfastâ pace-of-life syndrome, in that they reproduce more quickly but die upon infection. In contrast, proliferation resistance had no apparent costs and was associated with measures of positive host healthâsuch as having a higher body condition and reproductive rate. This study quantifies striking phenotypic variation in pathogen resistance and provides evidence for a link between life history variation and a disease resistance trait in a wild mammalian host population
Bovine tuberculosis disturbs parasite functional trait composition in African buffalo
Novel parasites can have wide-ranging impacts, not only on host populations, but also on the resident parasite community. Historically, impacts of novel parasites have been assessed by examining pairwise interactions between parasite species. However, parasite communities are complex networks of interacting species. Here we used multivariate taxonomic and trait-based approaches to determine how parasite community composition changed when African buffalo (Syncerus caffer) acquired an emerging disease, bovine tuberculosis (BTB). Both taxonomic and functional parasite richness increased significantly in animals that acquired BTB than in those that did not. Thus, the presence of BTB seems to catalyze extraordinary shifts in community composition. There were no differences in overall parasite taxonomic composition between infected and uninfected individuals, however. The trait-based analysis revealed an increase in direct-transmitted, quickly replicating parasites following BTB infection. This study demonstrates that trait-based approaches provide insight into parasite community dynamics in the context of emerging infections
Hazenella coriacea gen. nov., sp nov., isolated from clinical specimens
A Gram-staining-positive, endospore-forming rod was isolated independently from clinical specimens in New York State, USA, once in 2009 and twice in 2011. The three isolates had identical 16S rRNA gene sequences and, based on their 16S rRNA gene sequence, are most closely related to the type strains of Laceyella sediminis and L. sacchari (94.6% similarity). The partial 23S rRNA gene sequences of the three strains were also 100% identical. Maximumlikelihood phylogenetic analysis suggests that the new isolates belong to the family Thermoactinomycetaceae. Additional biochemical and phenotypic characteristics of the strains support the family designation and suggest that the three isolates represent a single species. In each of the strains, the predominant menaquinone is MK-7, the diagnostic diamino acid is mesodiaminopimelic acid and the major cellular fatty acids are iso-C15 : 0, anteiso-C15 : 0 and iso-C13 : 0.
The polar lipids are phosphatidylglycerol, diphosphatidylglycerol, phosphatidylethanolamine, four unknown phospholipids, four unknown aminophospholipids and an unknown lipid. It is proposed that the novel isolates represent a single novel species within a new genus, for which the name Hazenella coriacea gen. nov., sp. nov. is proposed. The type strain of Hazenella coriacea is strain 23436T (5DSM 45707T5LMG 27204T)
Rucaparib maintenance treatment for recurrent ovarian carcinoma after response to platinum therapy (ARIEL3): a randomised, double-blind, placebo-controlled, phase 3 trial
Background:
Rucaparib, a poly(ADP-ribose) polymerase inhibitor, has anticancer activity in recurrent ovarian carcinoma harbouring a BRCA mutation or high percentage of genome-wide loss of heterozygosity. In this trial we assessed rucaparib versus placebo after response to second-line or later platinum-based chemotherapy in patients with high-grade, recurrent, platinum-sensitive ovarian carcinoma.
Methods:
In this randomised, double-blind, placebo-controlled, phase 3 trial, we recruited patients from 87 hospitals and cancer centres across 11 countries. Eligible patients were aged 18 years or older, had a platinum-sensitive, high-grade serous or endometrioid ovarian, primary peritoneal, or fallopian tube carcinoma, had received at least two previous platinum-based chemotherapy regimens, had achieved complete or partial response to their last platinum-based regimen, had a cancer antigen 125 concentration of less than the upper limit of normal, had a performance status of 0â1, and had adequate organ function. Patients were ineligible if they had symptomatic or untreated central nervous system metastases, had received anticancer therapy 14 days or fewer before starting the study, or had received previous treatment with a poly(ADP-ribose) polymerase inhibitor. We randomly allocated patients 2:1 to receive oral rucaparib 600 mg twice daily or placebo in 28 day cycles using a computer-generated sequence (block size of six, stratified by homologous recombination repair gene mutation status, progression-free interval after the penultimate platinum-based regimen, and best response to the most recent platinum-based regimen). Patients, investigators, site staff, assessors, and the funder were masked to assignments. The primary outcome was investigator-assessed progression-free survival evaluated with use of an ordered step-down procedure for three nested cohorts: patients with BRCA mutations (carcinoma associated with deleterious germline or somatic BRCA mutations), patients with homologous recombination deficiencies (BRCA mutant or BRCA wild-type and high loss of heterozygosity), and the intention-to-treat population, assessed at screening and every 12 weeks thereafter. This trial is registered with ClinicalTrials.gov, number NCT01968213; enrolment is complete.
Findings:
Between April 7, 2014, and July 19, 2016, we randomly allocated 564 patients: 375 (66%) to rucaparib and 189 (34%) to placebo. Median progression-free survival in patients with a BRCA-mutant carcinoma was 16¡6 months (95% CI 13¡4â22¡9; 130 [35%] patients) in the rucaparib group versus 5¡4 months (3¡4â6¡7; 66 [35%] patients) in the placebo group (hazard ratio 0¡23 [95% CI 0¡16â0¡34]; p<0¡0001). In patients with a homologous recombination deficient carcinoma (236 [63%] vs 118 [62%]), it was 13¡6 months (10¡9â16¡2) versus 5¡4 months (5¡1â5¡6; 0¡32 [0¡24â0¡42]; p<0¡0001). In the intention-to-treat population, it was 10¡8 months (8¡3â11¡4) versus 5¡4 months (5¡3â5¡5; 0¡36 [0¡30â0¡45]; p<0¡0001). Treatment-emergent adverse events of grade 3 or higher in the safety population (372 [99%] patients in the rucaparib group vs 189 [100%] in the placebo group) were reported in 209 (56%) patients in the rucaparib group versus 28 (15%) in the placebo group, the most common of which were anaemia or decreased haemoglobin concentration (70 [19%] vs one [1%]) and increased alanine or aspartate aminotransferase concentration (39 [10%] vs none).
Interpretation:
Across all primary analysis groups, rucaparib significantly improved progression-free survival in patients with platinum-sensitive ovarian cancer who had achieved a response to platinum-based chemotherapy. ARIEL3 provides further evidence that use of a poly(ADP-ribose) polymerase inhibitor in the maintenance treatment setting versus placebo could be considered a new standard of care for women with platinum-sensitive ovarian cancer following a complete or partial response to second-line or later platinum-based chemotherapy.
Funding:
Clovis Oncology
Kroppenstedtia pulmonis sp. nov. and Kroppenstedtia sanguinis sp. nov., isolated from human patients
Three human clinical strains (W9323T, X0209T and X0394) isolated from lung biopsy, blood and cerebral spinal fluid, respectively, were characterized using a polyphasic taxonomic approach. Comparative analysis of the 16S rRNA gene sequences showed the three strains belonged to two novel branches within the genus Kroppenstedtia: 16S rRNA gene sequence analysis of W9323T showed closest sequence similarity to Kroppenstedtia eburnea JFMB-ATE T (95.3 %), Kroppenstedtia guangzhouensis GD02T (94.7 %) and strain X0209T (94.6 %); sequence analysis of strain X0209T showed closest sequence similarity to K. eburnea JFMB-ATE T (96.4 %) and K. guangzhouensis GD02T (96.0 %). Strains X0209T and X0394 were 99.9 % similar to each other by 16S rRNA gene sequence analysis. The DNA-DNA relatedness was 94.6 %, confirming that X0209T and X0394 belong to the same species. Chemotaxonomic data for strains W9323T and X0209T were consistent with those described for the genus Kroppenstedtia: whole-cell peptidoglycan contained LLdiaminopimelic acid; the major cellular fatty acids were iso-C15 and anteiso-C15; and the major menaquinone was MK-7. Different endospore morphology and carbon utilization profiles of strains W9323T and X0209T supported by phylogenetic analysis enabled us to conclude that the strains represent two new species within the genus Kroppenstedtia, for which the names Kroppenstedtia pulmonis sp. nov. (type strain W9323T =DSM 45752 T) and Kroppenstedtia sanguinis sp. nov. (type strain X0209T =DSM 45749T=CCUG 38657 T) are proposed
Adaptation and diagnostic potential of a commercial cat interferon gamma release assay for the detection of Mycobacterium bovis infection in African lions (Panthera leo)
CITATION: Gumbo, R. et al. 2022. Adaptation and diagnostic potential of a commercial cat interferon gamma release assay for the detection of Mycobacterium bovis infection in African lions (Panthera leo). Pathogens, 11:765, doi:10.3390/pathogens11070765.The original publication is available at https://www.mdpi.comMycobacterium bovis (M. bovis) infection in wildlife, including lions (Panthera leo), has
implications for individual and population health. Tools for the detection of infected lions are needed
for diagnosis and disease surveillance. This study aimed to evaluate the Mabtech Cat interferon
gamma (IFN-Îł) ELISABasic kit for detection of native lion IFN-Îł in whole blood samples stimulated
using the QuantiFERONÂŽ TB Gold Plus (QFT) platform as a potential diagnostic assay. The ELISA
was able to detect lion IFN-Îł in mitogen-stimulated samples, with good parallelism, linearity, and
a working range of 15.6â500 pg/mL. Minimal matrix interference was observed in the recovery of
domestic cat rIFN-Îł in lion plasma. Both intra- and inter-assay reproducibility had a coefficient
of variation less than 10%, while the limit of detection and quantification were 7.8 pg/mL and
31.2 pg/mL, respectively. The diagnostic performance of the QFT Mabtech Cat interferon gamma
release assay (IGRA) was determined using mycobacterial antigen-stimulated samples from M. bovis
culture-confirmed infected (n = 8) and uninfected (n = 4) lions. A lion-specific cut-off value (33 pg/mL)
was calculated, and the sensitivity and specificity were determined to be 87.5% and 100%, respectively.
Although additional samples should be tested, the QFT Mabtech Cat IGRA could identify M. bovisinfected African lions.https://www.mdpi.com/2076-0817/11/7/765Publisher's versio
Acetate Kinase Isozymes Confer Robustness in Acetate Metabolism
Acetate kinase (ACK) (EC no: 2.7.2.1) interconverts acetyl-phosphate and acetate to either catabolize or synthesize acetyl-CoA dependent on the metabolic requirement. Among all ACK entries available in UniProt, we found that around 45% are multiple ACKs in some organisms including more than 300 species but surprisingly, little work has been done to clarify whether this has any significance. In an attempt to gain further insight we have studied the two ACKs (AckA1, AckA2) encoded by two neighboring genes conserved in Lactococcus lactis (L. lactis) by analyzing protein sequences, characterizing transcription structure, determining enzyme characteristics and effect on growth physiology. The results show that the two ACKs are most likely individually transcribed. AckA1 has a much higher turnover number and AckA2 has a much higher affinity for acetate in vitro. Consistently, growth experiments of mutant strains reveal that AckA1 has a higher capacity for acetate production which allows faster growth in an environment with high acetate concentration. Meanwhile, AckA2 is important for fast acetate-dependent growth at low concentration of acetate. The results demonstrate that the two ACKs have complementary physiological roles in L. lactis to maintain a robust acetate metabolism for fast growth at different extracellular acetate concentrations. The existence of ACK isozymes may reflect a common evolutionary strategy in bacteria in an environment with varying concentrations of acetate
Extension of sylvatic circulation of African swine fever virus in extralimital warthogs in South Africa
Sylvatic circulation of African swine fever virus (ASFV) in warthogs and Ornithodoros ticks
that live in warthog burrows historically occurred in northern South Africa. Outbreaks of
the disease in domestic pigs originated in this region. A controlled area was declared
in the north in 1935 and regulations were implemented to prevent transfer of potentially
infected suids or products to the rest of the country. However, over the past six decades,
warthogs have been widely translocated to the south where the extralimital animals have
flourished to become an invasive species. Since 2016, there have been outbreaks of ASF
in pigs outside the controlled area that cannot be linked to transfer of infected animals
or products from the north. An investigation in 2008â2012 revealed that the presence
of Ornithodoros ticks and ASFV in warthog burrows extended marginally across the
boundary of the controlled area. We found serological evidence of ASFV circulation in
extralimital warthogs further south in the central part of the country.NBAF Transition funds from the State of Kansas, the P20GM130448 and the Department of Homeland Security Center of Excellence for Emerging and Zoonotic Animal Diseases.https://www.frontiersin.org/journals/veterinary-science#am2022Veterinary Tropical Disease
The Effects of Pathological Gaming on Aggressive Behavior
Studies have shown that pathological involvement with computer or video games is related to excessive gaming binges and aggressive behavior. Our aims for this study were to longitudinally examine if pathological gaming leads to increasingly excessive gaming habits, and how pathological gaming may cause an increase in physical aggression. For this purpose, we conducted a two-wave panel study among 851 Dutch adolescents (49% female) of which 540 played games (30% female). Our analyses indicated that higher levels of pathological gaming predicted an increase in time spent playing games 6Â months later. Time spent playing violent games specifically, and not just games per se, increased physical aggression. Furthermore, higher levels of pathological gaming, regardless of violent content, predicted an increase in physical aggression among boys. That this effect only applies to boys does not diminish its importance, because adolescent boys are generally the heaviest players of violent games and most susceptible to pathological involvement
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