Coxiella Endosymbiont of Rhipicephalus microplus Modulates Tick Physiology With a Major Impact in Blood Feeding Capacity

In the past decade, metagenomics studies exploring tick microbiota have revealed widespread interactions between bacteria and arthropods, including symbiotic interactions. Functional studies showed that obligate endosymbionts contribute to tick biology, affecting reproductive fitness and molting. Understanding the molecular basis of the interaction between ticks and their mutualist endosymbionts may help to develop control methods based on microbiome manipulation. Previously, we showed that Rhipicephalus microplus larvae with reduced levels of Coxiella endosymbiont of R. microplus (CERM) were arrested at the metanymph life stage (partially engorged nymph) and did not molt into adults. In this study, we performed a transcriptomic differential analysis of the R. microplus metanymph in the presence and absence of its mutualist endosymbiont. The lack of CERM resulted in an altered expression profile of transcripts from several functional categories. Gene products such as DA-P36, protease inhibitors, metalloproteases, and evasins, which are involved in blood feeding capacity, were underexpressed in CERM-free metanymphs. Disregulation in genes related to extracellular matrix remodeling was also observed in the absence of the symbiont. Taken together, the observed alterations in gene expression may explain the blockage of development at the metanymph stage and reveal a novel physiological aspect of the symbiont-tick-vertebrate host interaction.

Draft genome sequence data of Cercospora kikuchii, a causal agent of Cercospora leaf blight and purple seed stain of soybeans

Cercospora kikuchii (Tak. Matsumoto & Tomoy.) M.W. Gardner 1927 is an ascomycete fungal pathogen that causes Cercospora leaf blight and purple seed stain on soybean. Here, we report the first draft genome sequence and assembly of this pathogen. The C. kikuchii strain ARG_18_001 was isolated from soybean purple seed collected from San Pedro, Buenos Aires, Argentina, during the 2018 harvest. The genome was sequenced using a 2 × 150 bp paired-end method by Illumina NovaSeq 6000. The C. kikuchii protein-coding genes were predicted using FunGAP (Fungal Genome Annotation Pipeline). The draft genome assembly was 33.1 Mb in size with a GC-content of 53%. The gene prediction resulted in 14,856 gene models/14,721 protein coding genes. Genomic data of C. kikuchii presented here will be a useful resource for future studies of this pathosystem. The data can be accessed at GenBank under the accession number VTAY00000000 https://www.ncbi.nlm.nih.gov/nuccore/VTAY00000000.

P1552Different forms of evaluation of atherosclerotic load and its different predicted powers compared with framingham risk score

Introduction

The screening of carotid and/or ileo-femoral subclinical atherosclerosis using vascular ultrasound could be a cost-effective tool in the reclassification of cardiovascular risk in primary cardiovascular prevention. But until today we don't have evidence indicating which atherosclerotic load indicator variable (such as plaque area, number of atherosclerotic plaques or affected territories) has the most predictive power for future cardiovascular events.

Objectives

a. Evaluate the prevalence of carotid and ileo-femoral subclinical atherosclerosis (SubAth). b. Evaluate the predictive power of each atherosclerotic load indicator variable for cardiovascular events (CVE). c. to compare those methods with Framingham Score for prediction of CVE.

Material and methods

We retrospectively evaluated patients from our registry called CARFARE (CARDIOMETABOLIC RISK FACTORS REGISTRY) conducted in the context of a cardiovascular primary prevention program (n=6108). In this analysis we included only those patients who completed a follow up ≥24 months from the first vascular evaluation. Exclusion criteria: <40 or >65 years old, BMI>40 kg/m2, previous cardiovascular and/or cerebrovascular event, chronic stable angina. We used Framingham score for the cardiovascular risk assessment. We evaluated the following atherosclerotic load variables using high resolution vascular ultrasonography (Mannheim Consensus): carotid plaques area (AR-C), ileo-femoral plaques area (AR-IF), and total (carotid+ileo-femoral, AR-TOT), number of affected territories (N-TER). Primary composite endpoints (P-CVE): myocardial infarction, stroke, hospitalization due to angina or acute heart failure. For prediction power analysis we used ROC curves and logistic regressions (unadjusted and adjusted by age, sex, BMI, major cardiovascular risk factors and treatment).

Results

We included 1431 patients (55.0±9.78 y.o., 38% women, follow-up period of 789±23 days). The total P-CVE rate was 3.77% during this period (54 events). The overall prevalence of atherosclerosis in this population was 60.7%. The AUC of the ROC curves for P-CVE prediction was 0.648, for Framingham 0.706, for AR-C 0.726, for AR-IF 0.746, for AR-TOT and 0.79 for N-TER (graph). The AUC of AR-TOT and N-TER were significantly higher than the AUC of the Framingham score (p=0.017 and p=0.0004, respectively) for prediction of P-CVE. The dichotomization criteria according to ROC were: AR-C>5.80 mm2, AR-IF>23.0 mm2, AR-TOT>43.9 mm2, and N-TER>1. In the logistic regressions adjusted for prediction of P-CVE the OR were: Framingham 1.05 (95% CI: 1.02–1.07), AR-C 4.00 (95% CI: 1.89–8.47), AR-IF 4.01 (95% CI: 2.02–8.32), AR-TOT 4.35 (95% CI: 2.13- 8.91) and N-TER 6.95 (95% CI: 3.05–15.8).

Comparison of ROC curves for CVE

Conclusions

The carotid/ileo-femoral SubAth scan was a more potent predictor of cardiovascular events than the Framingham score, particularly those variables that indicate extension of multiterritorial affection like AR-TOT or N-TER.

Safety and efficacy of ledipasvir/sofosbuvir with or without ribavirin in hepatitis C genotype 1 patients including those with decompensated cirrhosis who failed prior treatment with simeprevir/sofosbuvir

BACKGROUND

Combination therapy of simeprevir (SIM)/sofosbuvir (SOF) is an approved treatment for hepatitis C genotype (gen) 1 with overall SVR12 rate of 85%-95%. The single tablet fixed-dose combination of ledipasvir (LDV)/SOF is also approved for gen 1 with sustained virologic response at 12 weeks (SVR12) rates ≥95%. No data are available on the efficacy of retreatment with LDV/SOF in patients who failed initial treatment with SIM/SOF.

AIM

To evaluate the efficacy of retreatment with LDV/SOF ± ribavirin (RBV) in gen 1 patients who had previously failed treatment with SIM/SOF.

METHODS

Data from a combined treatment cohort of 2 hepatology centres, which included patients previously treated with SIM/SOF ± RBV for 12 weeks but failed to achieve SVR and then underwent retreatment with LDV/SOF ± RBV, were analysed (n = 30). LDV/SOF ± RBV was administered for 12-24 weeks based on the discretion of the treating hepatologist.

RESULTS

Of the 30 patients, 23 (77%) were male, 77% were Caucasian and 26 (87%) were gen 1a. 26 (86%) had cirrhosis, of which 16 (62%) had decompensated, Child's class B or C cirrhosis. Three patients were liver transplant recipients with recurrent hepatitis C. Overall, 27/30 (90%) achieved SVR. Treatment was well tolerated with 37% reporting no adverse events. The most common adverse events were fatigue, headache, insomnia and nausea. Two patients with Child's B cirrhosis required hospitalization during treatment for variceal haemorrhage and abdominal pain respectively. However, no treatment discontinuations or deaths occurred.

CONCLUSION

Single tablet fixed-dose combination LDV/SOF ± RBV is efficacious and well tolerated in patients who previously failed treatment with SIM/SOF, including those with decompensated cirrhosis and recurrent hepatitis C following liver transplantation.

Relationships between active school transport and adiposity indicators in school-age children from low-, middle- and high-income countries

OBJECTIVES

Within the global context of the nutrition and physical activity transition it is important to determine the relationship between adiposity and active school transport (AST) across different environmental and socio-cultural settings. The present study assessed the association between adiposity (that is, body mass index z-score (BMIz), obesity, percentage body fat (PBF), waist circumference) and AST in 12 country sites, in the International Study of Childhood Obesity, Lifestyle and the Environment (ISCOLE).

METHODS

The analytical sample included 6797 children aged 9-11 years. Adiposity indicators included, BMIz calculated using reference data from the World Health Organization, obesity (BMIz ⩾+2 s.d.), PBF measured using bioelectrical impedance and waist circumference. School travel mode was assessed by questionnaire and categorized as active travel versus motorized travel. Multilevel linear and non-linear models were used to estimate the magnitude of the associations between adiposity indicators and AST by country site and sex.

RESULTS

After adjusting for age, sex, parental education and motorized vehicle availability, children who reported AST were less likely to be obese (odds ratio=0.72, 95% confidence interval (0.60-0.87), P<0.001) and had a lower BMIz (-0.09, s.e.m.=0.04, P=0.013), PBF (least square means (LSM) 20.57 versus 21.23% difference -0.66, s.e.m.=0.22, P=0.002) and waist circumference (LSM 63.73 cm versus 64.63 cm difference -0.90, s.e.m.=0.26, P=0.001) compared with those who reported motorized travel. Overall, associations between obesity and AST did not differ by country (P=0.279) or by sex (P=0.571).

CONCLUSIONS

AST was associated with lower measures of adiposity in this multinational sample of children. Such findings could inform global efforts to prevent obesity among school-age children.

Risk assessment for hepatocellular carcinoma in chronic hepatitis B: scores and surveillance

Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death (1). Chronic infection with hepatitis B virus (HBV) is a major risk factor for HCC, accounting for more than one half of cases worldwide (2). Early detection of HCC in populations with chronic HBV infection through surveillance methods is critically important in providing definitive treatment for HCC and has a major impact on patient outcomes (3), including a survival benefit as demonstrated in one prospective randomised controlled trial (4). Efforts to identify populations and individuals with HBV infection who are at high risk may contribute to the development of surveillance strategies with the greatest impact on patient outcomes; however, the implementation of an individualised approach to surveillance can be challenging. This Perspective aims to explore risk factors associated with HCC in patients with chronic HBV infection, recent data on developing scoring systems to assess risk, and how these may impact surveillance strategies.

Inverse association between hepatic stellate cell apoptosis and fibrosis in chronic hepatitis C virus infection

Perisinusoidal hepatic stellate cells (HSC) are the principal fibrogenic cells in the liver. In animal models, HSC apoptosis is the predominant clearance mechanism of activated HSC, although data evaluating whether the same processes occur in humans are limited. We conducted a cross-sectional study to evaluate the association between HSC apoptosis and fibrosis stage in subjects with chronic hepatitis C virus (HCV) infection (n = 44) and HCV-negative controls with normal liver histology (n = 9). We used immunohistochemical techniques to identify activated (alpha-smooth muscle actin+), proliferative (Ki-67+) and apoptotic (terminal deoxynucleotidyl transferase [TdT]-mediated dUTP nick end-labelling+) HSC in liver biopsy specimens from all subjects. The same pathologist enumerated positive cells per high-power field (HPF, x 200) in 20 periportal/lobular areas. HSC apoptosis was decreased in HCV-positive subjects compared with controls (median 0.4, range 0.0-3.1 vs 1.1, 0.2-3.5 cells/HPF, P = 0.02). Among HCV-positive subjects, HSC apoptosis was decreased in those with moderate to advanced fibrosis (P = 0.04) compared with those with mild fibrosis. By multivariate analysis, HSC apoptosis decreased by an average of 0.14 cells/HPF (95% confidence interval 0.01-0.28 cells/HPF) per increase in fibrosis stage (P = 0.04). While the number of activated and proliferative HSC was significantly increased in HCV-infected subjects compared with that in uninfected controls, the numbers of these cells did not differ between HCV-infected subjects with mild vs moderate/advanced fibrosis. In conclusion, the number of apoptotic HSC was significantly decreased in HCV-infected subjects with advanced fibrosis. In chronic HCV infection, inhibition of HSC apoptosis may be one mechanism by which fibrosis progresses.

Hepatic inflammatory cytokine mRNA expression in hepatitis C virus-human immunodeficiency virus co-infection

Although epidemiologic studies have documented that hepatitis C virus (HCV)/human immunodeficiency virus (HIV) co-infected patients have accelerated fibrogenesis, especially those with CD4+ cell counts <200 cells/mm(3), the pathogenic mechanisms are poorly understood. We investigated whether severe immunodeficiency in co-infection is associated with changes in intrahepatic inflammatory cytokine mRNA levels. We measured interferon (IFN)-gamma, tumour necrosis factor-alpha, transforming growth factor (TGF)-beta(1), interleukin (IL)-4, IL-10, IL-12p35 and IL-12p40 mRNA levels by real-time PCR performed on liver samples from HCV mono-infected (n = 19) and HCV/HIV co-infected (n = 24) patients. Co-infected patients had decreased intrahepatic mRNA levels of IFN-gamma (P = 0.09), IL-4 (P = 0.05) and IL-12p35 (P = 0.04) compared with mono-infected patients, while IL-10 was increased (P = 0.07). In co-infected patients, IFN-gamma mRNA levels increased linearly with increasing peripheral CD4+ cell counts by 1.23 times relative to the calibrator for every 100 CD4+ cells/mm(3) increase (P = 0.02). No other cytokines were significantly associated with CD4+ cell counts. In conclusion, HIV-induced lymphopenia may result in hepatic inflammatory cytokine suppression in HCV/HIV co-infection. Intrahepatic IFN-gamma levels are significantly reduced in patients with advanced immunodeficiency. Further studies are needed to assess whether decreased IFN-gamma secretion by HCV-specific CD4+ cells may account for accelerated fibrogenesis in these patients.

CD56(+dim) and CD56(+bright) cell activation and apoptosis in hepatitis C virus infection

CD3- CD56(+dim) natural killer (NK) cells, which are cytotoxic against virally infected cells, may be important in hepatitis C virus (HCV)-infected patients who are successfully treated with pegylated interferon (PEG-IFN)-alpha. We used flow cytometry to enumerate activated (CD69+) and apoptotic (annexin-V+) dim (CD3- CD56(+dim)) and bright (CD3- CD56(+bright)) NK cells obtained from HCV-infected patients before treatment (n=16) and healthy controls (n=15) in the absence and presence of pegylated interferon (PEG-IFN)-alpha-2b. A subset of HCV-infected patients, subsequently treated with PEG-IFN-alpha-2b in vivo, was determined to have a sustained virological response (SVR, n=6) or to not respond (NR) to treatment (n=5). In the absence of IFN, activated dim (CD3- CD56(+dim) CD69+) NK cells were significantly decreased (P=0.04) while activated apoptotic dim (CD3- CD56(+dim)CD69+ annexin-V+) NK cells tended to be increased (P=0.07) in SVR patients compared with NR patients. Activated bright (CD3-CD56(+bright)CD69+) and activated apoptotic bright (CD3- CD56(+bright)CD69+ annexin-V+) NK cells were significantly correlated (P=0.02 and P=0.01, respectively) with increasing hepatic inflammation. These findings suggest that in the absence of PEG-IFN, activated dim (CD3- CD56(+dim)CD69+) NK cell turnover may be enhanced in SVR compared with NR patients and that activated bright (CD3- CD56(+bright)CD69+) NK cells may play a role in liver inflammation.

Automatic temperature controller for maintaining body temperature in experimental animals

A system for autoregulation of body temperature of large and small animals is described. The device uses the IC AD590 as a temperature transducer. It operates on the basis of continuous regulation of the heating current, and does not emit transients which interfere with electrical recordings. A panel meter shows either the rectal temperature of the animal or the current flow to the blanket.