Effects of cucumber mosaic virus‐infected chilli plants on non‐vector Bemisia tabaci (Hemiptera: Aleyrodidae)

Plant virus infections are known to alter host plant attractiveness and suitability for insect herbivores.This study was conducted to determine how cucumber mosaic virus (CMV)-infected chilli plants affect the fitness and settling preferences ofnonvector whitefly,Bemisia tabaci adults under dual-choice conditions with volatile organic compounds analyzed using solid phase microextraction coupled with gas chromatography-mass spectrometry (GC-MS).Results showed that the presence of CIVIV in chilli plants substantially affects the settling preferences of the B.tabaci,which preferred to settle on noninfected plants.Duration of the egg stage and the longevity and fecundity of adult B.tabaci on CMV-infected chilli plants were not markedly different from those on noninfected chilli plants.In contrast,the developmental time from egg to adult was significantly reduced in CMV-infected chilli plants compared to the noninfected plants.The results also showed that CMV-infected chilli plants released significantly more linalool and phenylacetaldehyde than noninfected plants.Overall,it was suggested that the behavioral response of B.tabaci might be modified by CMV-infected plants,which alter the release of specific headspace volatiles.Based on these results,the modification of plant volatile profiles may help in enhancing the effectiveness of biological control and the protection of crop plants against B.tabaci.     

Screening Primary-Care Patients Forgoing Health Care for Economic Reasons

Background

Growing social inequities have made it important for general practitioners to verify if patients can afford treatment and procedures. Incorporating social conditions into clinical decision-making allows general practitioners to address mismatches between patients'' health-care needs and financial resources.

Objectives

Identify a screening question to, indirectly, rule out patients'' social risk of forgoing health care for economic reasons, and estimate prevalence of forgoing health care and the influence of physicians'' attitudes toward deprivation.

Design

Multicenter cross-sectional survey.

Participants

Forty-seven general practitioners working in the French–speaking part of Switzerland enrolled a random sample of patients attending their private practices.

Main Measures

Patients who had forgone health care were defined as those reporting a household member (including themselves) having forgone treatment for economic reasons during the previous 12 months, through a self-administered questionnaire. Patients were also asked about education and income levels, self-perceived social position, and deprivation levels.

Key Results

Overall, 2,026 patients were included in the analysis; 10.7% (CI95% 9.4–12.1) reported a member of their household to have forgone health care during the 12 previous months. The question “Did you have difficulties paying your household bills during the last 12 months” performed better in identifying patients at risk of forgoing health care than a combination of four objective measures of socio-economic status (gender, age, education level, and income) (R² = 0.184 vs. 0.083). This question effectively ruled out that patients had forgone health care, with a negative predictive value of 96%. Furthermore, for physicians who felt powerless in the face of deprivation, we observed an increase in the odds of patients forgoing health care of 1.5 times.

Conclusion

General practitioners should systematically evaluate the socio-economic status of their patients. Asking patients whether they experience any difficulties in paying their bills is an effective means of identifying patients who might forgo health care.     

Dengue Virus Type 2 (DENV2)-Induced Oxidative Responses in Monocytes from Glucose-6-Phosphate Dehydrogenase (G6PD)-Deficient and G6PD Normal Subjects

Background

Dengue virus is endemic in peninsular Malaysia. The clinical manifestations vary depending on the incubation period of the virus as well as the immunity of the patients. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is prevalent in Malaysia where the incidence is 3.2%. It has been noted that some G6PD-deficient individuals suffer from more severe clinical presentation of dengue infection. In this study, we aim to investigate the oxidative responses of DENV2-infected monocytes from G6PD-deficient individuals.

Methodology

Monocytes from G6PD-deficient individuals were infected with DENV2 and infection rate, levels of oxidative species, nitric oxide (NO), superoxide anions (O₂ ⁻), and oxidative stress were determined and compared with normal controls.

Principal Findings

Monocytes from G6PD-deficient individuals exhibited significantly higher infection rates compared to normal controls. In an effort to explain the reason for this enhanced susceptibility, we investigated the production of NO and O₂ ⁻ in the monocytes of individuals with G6PD deficiency compared with normal controls. We found that levels of NO and O₂ ⁻ were significantly lower in the DENV-infected monocytes from G6PD-deficient individuals compared with normal controls. Furthermore, the overall oxidative stress in DENV-infected monocytes from G6PD-deficient individuals was significantly higher when compared to normal controls. Correlation studies between DENV-infected cells and oxidative state of monocytes further confirmed these findings.

Conclusions/Significance

Altered redox state of DENV-infected monocytes from G6PD-deficient individuals appears to augment viral replication in these cells. DENV-infected G6PD-deficient individuals may contain higher viral titers, which may be significant in enhanced virus transmission. Furthermore, granulocyte dysfunction and higher viral loads in G6PD-deificient individuals may result in severe form of dengue infection.     

Influences of leaf age and type,non‐host volatiles,and mineral oil deposits on the incidence,distribution, and form of stylet tracks of Diaphorina citri

Psyllids produce saliva that gels to form a protective sheath around their stylets. This saliva can be visualized as stylet tracks, and we have used the presence of tracks to study the feeding behaviour of Diaphorina citri Kuwayama (Hemiptera: Liviidae). Both single and branched tracks were produced by nymphs and adults, and the tracks made by males and females did not differ. Tracks dissipated from calamondin leaves within a 7‐day post‐feeding period after adults fed for 2 days and numbers of tracks declined with increasing maturity of calamondin leaves. In the six host plants studied, most psyllids fed abaxially from midribs and most probes traversed or terminated in the tissue (midrib, lateral vein, minor vein, or mesophyll) above which the stylets entered the leaf or leaflet. The number of tracks and landings were recorded on the six hosts in choice tests. More tracks were found in leaves or leaflets of orange jasmine, wampee, and trifoliate orange than in sour orange, calamondin, and lemon. Orange jasmine is considered a preferred host of D. citri, and this is in agreement with the number of tracks found in this study, but not the number of landings. Trifoliate orange is considered a poor host of D. citri, which, in this study, is reflected in the low number of landings, but not in the numbers of tracks. Our results indicate that the presence of adult psyllids on a plant may not reflect its host status, and that the presence of stylet tracks should also be determined in host preference studies. When calamondin leaves were paired with leaves of guava, billygoat weed, or greenleaf desmodium, the presence of volatiles from these plants reduced feeding by adults on calamondin and suggests that understoreys of billygoat weed or desmodium in orchards may also reduce feeding. A negative, exponential relationship between numbers of tracks per leaf and the concentrations of an agricultural mineral oil applied to leaf surfaces was found. This reduction in feeding, in conjunction with reductions in oviposition, has practical implications for suppressing psyllid populations in orchards.     

Effects of orally administered tetracycline on the intestinal community structure of chickens and on tet determinant carriage by commensal bacteria and Campylobacter jejuni

There is a growing concern that antibiotic usage in animal production has selected for resistant food-borne bacteria. Since tetracyclines are common therapeutic antibiotics used in poultry production, we sought to evaluate the effects of oral administration on the resistance of poultry commensal bacteria and the intestinal bacterial community structure. The diversity indices calculated from terminal restriction fragment length polymorphism (T-RFLP) analysis of 16S rRNA amplicons did not indicate significant changes in the cecal bacterial community in response to oxytetracycline. To evaluate its effects on cultivable commensals, Enterococcus spp., Escherichia coli, and Campylobacter spp. were isolated from the cecal droppings of broiler chickens. Enterococcus spp. and E. coli expressed tetracycline MICs of >8 microg/ml and harbored a variety of tet resistance determinants regardless of the tetracycline exposure history of the birds. The enterococcal isolates possessed tetM (61%), tetL (25.4%), and tetK (1.3%), as well as tetO (52.5%), the determinant known to confer a tetracycline resistance phenotype in Campylobacter jejuni. E. coli isolates harbored tetA (32.2%) or tetB (30.5%). Tetracycline MICs remained at <2 microg/ml for Campylobacter isolates before and after tetracycline treatment of the chickens, even though isolates expressing MICs of >16 mug/ml were commonly cultured from flocks that did not receive oxytetracycline. The results imply that complex ecological and genetic factors contribute to the prevalence of antibiotic resistance arising from resistance gene transfer in the production environment.     

Simenoside A,a New Triterpenoid Saponin from Gypsophila simonii Hub.‐Mor.

Saponins are amphiphilic glycoconjugates which give soap‐like foams in H₂O. A new triterpenoid saponin, simenoside A ( 1 ), based on gypsogenin aglycone, and the known saponin 2 were isolated from Gypsophila simonii Hub.‐Mor. The structure of the new saponin was elucidated as 3‐O‐β‐D ‐galactopyranosyl‐(1→2)‐[β‐D ‐xylopyranosyl‐(1→3)]‐β‐D ‐glucuronopyranosylgypsogenin 28‐O‐β‐D ‐glucopyranosyl‐(1→3)‐[β‐D ‐glucopyranosyl‐(1→2)‐β‐D ‐xylopyranosyl‐(1→4)]‐α‐L ‐rhamnopyranosyl‐(1→2)‐β‐D ‐fucopyranosyl ester on the basis of extensive spectral analyses and chemical evidence. Saponins 1 and 2 were isolated from G. simonii for the first time.     

Diversity and succession of the intestinal bacterial community of the maturing broiler chicken

The diversity of bacterial floras in the ilea and ceca of chickens that were fed a vegetarian corn-soy broiler diet devoid of feed additives was examined by analysis of 1,230 partial 16S rRNA gene sequences. Nearly 70% of sequences from the ileum were related to those of Lactobacillus, with the majority of the rest being related to Clostridiaceae (11%), Streptococcus (6.5%), and Enterococcus (6.5%). In contrast, Clostridiaceae-related sequences (65%) were the most abundant group detected in the cecum, with the other most abundant sequences being related to Fusobacterium (14%), Lactobacillus (8%), and Bacteroides (5%). Statistical analysis comparing the compositions of the different 16S rRNA libraries revealed that population succession occurred during some sampling periods. The significant differences among cecal libraries at 3 and 7 days of age, at 14 to 28 days of age, and at 49 days of age indicated that successions occurred from a transient community to one of increasing complexity as the birds aged. Similarly, the ileum had a stable bacterial community structure for birds at 7 to 21 days of age and between 21 to 28 days of age, but there was a very unique community structure at 3 and 49 days of age. It was also revealed that the composition of the ileal and cecal libraries did not significantly differ when the birds were 3 days old, and in fact during the first 14 days of age, the cecal microflora was a subset of the ileal microflora. After this time, the ileum and cecum had significantly different library compositions, suggesting that each region developed its own unique bacterial community as the bird matured.     

Bacterial communities associated with flowering plants of the Ni hyperaccumulator Thlaspi goesingense

Thlaspi goesingense is able to hyperaccumulate extremely high concentrations of Ni when grown in ultramafic soils. Recently it has been shown that rhizosphere bacteria may increase the heavy metal concentrations in hyperaccumulator plants significantly, whereas the role of endophytes has not been investigated yet. In this study the rhizosphere and shoot-associated (endophytic) bacteria colonizing T. goesingense were characterized in detail by using both cultivation and cultivation-independent techniques. Bacteria were identified by 16S rRNA sequence analysis, and isolates were further characterized regarding characteristics that may be relevant for a beneficial plant-microbe interaction-Ni tolerance, 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase and siderophore production. In the rhizosphere a high percentage of bacteria belonging to the Holophaga/Acidobacterium division and alpha-Proteobacteria were found. In addition, high-G+C gram-positive bacteria, Verrucomicrobia, and microbes of the Cytophaga/Flexibacter/Bacteroides division colonized the rhizosphere. The community structure of shoot-associated bacteria was highly different. The majority of clones affiliated with the Proteobacteria, but also bacteria belonging to the Cytophaga/Flexibacter/Bacteroides division, the Holophaga/Acidobacterium division, and the low-G+C gram-positive bacteria, were frequently found. A high number of highly related Sphingomonas 16S rRNA gene sequences were detected, which were also obtained by the cultivation of endophytes. Rhizosphere isolates belonged mainly to the genera Methylobacterium, Rhodococcus, and Okibacterium, whereas the majority of endophytes showed high levels of similarity to Methylobacterium mesophilicum. Additionally, Sphingomonas spp. were abundant. Isolates were resistant to Ni concentrations between 5 and 12 mM; however, endophytes generally tolerated higher Ni levels than rhizosphere bacteria. Almost all bacteria were able to produce siderophores. Various strains, particularly endophytes, were able to grow on ACC as the sole nitrogen source.