Identification and molecular characterization of cotton leaf curl Gezira betasatellite and two distinct begomoviruses infecting papaya trees in the Kingdom of Saudi Arabia

Begomovirus is the largest genus in the family Geminiviridae and constitutes more than 445 virus species. Begomoviruses are characterized by single-stranded circular genomes with monopartite or bipartite components and transmitted by whitefly (Bemisia tabaci). Begomoviruses cause severe diseases in many economically important crops throughout the world. Typical symptoms of a begomovirus infection including severe leaf curling, vein thickening, vein darkening and reduced leaf size were observed in papaya plants in the Dammam district of the Eastern Province of Saudi Arabia during the growing season in 2022. A total of 10 samples were collected, and total genomic DNA was isolated from naturally infected papaya tree samples and subjected to PCR amplification using universal diagnostic primers for begomoviruses and associated satellites. Three PCR-amplified genomic components of begomoviruses and betasatellite namely P61Begomo (645 bp), P62Begomo (341 bp) and P62Beta (563 bp) were sent for Sanger DNA sequencing to Macrogen Inc. These partial viral genome sequences were submitted to Genbank database and accession numbers ON206051, ON206052 and ON206050 were assigned to P61Begomo, P62Begomo and P62Beta respectively. Phylogenetic analysis and pairwise nucleotide sequence identity studies identified P61Begomo was identified as Tomato yellow leaf curl virus, P62Begomo as DNA A component of a bipartite begomovirus Watermelon chlorotic stunt virus and P62Beta as begomovirus associated betasatellite; Cotton leaf curl Gezira betasatellite. To the best of our knowledge, this is the first report of a begomovirus complex infecting papaya (Carica papaya) in the Kingdom of Saudi Arabia.

Enhanced Protection by Recombinant Newcastle Disease Virus Expressing Infectious Bronchitis Virus Spike Ectodomain and Chicken Granulocyte-Macrophage Colony-Stimulating Factor

We previously reported that recombinant Newcastle disease virus LaSota (rLS) expressing infectious bronchitis virus (IBV) Arkansas (Ark)-type trimeric spike (S) ectodomain (Se; rLS/ArkSe) provides suboptimal protection against IBV challenge. We have now developed rLS expressing chicken granulocyte-macrophage colony-stimulating factor (GMCSF) and IBV Ark Se in an attempt to enhance vaccine effectiveness. In the current study, we first compared protection conferred by vaccination with rLS/ArkSe and rLS/ArkSe.GMCSF. Vaccinated chickens were challenged with virulent Ark, and protection was determined by clinical signs, viral load, and tracheal histomorphometry. Results showed that coexpression of GMCSF and the Se from rLS significantly reduced tracheal viral load and tracheal lesions compared with chickens vaccinated with rLS/ArkSe. In a second experiment, we evaluated enhancement of cross-protection of a Massachusetts (Mass) attenuated vaccine by priming or boosting with rLS/ArkSe.GMCSF. Vaccinated chickens were challenged with Ark, and protection was evaluated. Results show that priming or boosting with the recombinant virus significantly increased cross-protection conferred by Mass against Ark virulent challenge. Greater reductions of viral loads in both trachea and lachrymal fluids were observed in chickens primed with rLS/ArkSe.GMCSF and boosted with Mass. Consistently, Ark Se antibody levels measured with recombinant Ark Se protein-coated ELISA plates 14 days after boost were significantly higher in these chickens. Unexpectedly, the inverse vaccination scheme, that is, priming with Mass and boosting with the recombinant vaccine, proved somewhat less effective. We concluded that a prime and boost strategy by using rLS/ArkSe.GMCSF and the worldwide ubiquitous Mass attenuated vaccine provides enhanced cross-protection. Thus, rLS/GMCSF coexpressing the Se of regionally relevant IBV serotypes could be used in combination with live Mass to protect against regionally circulating IBV variant strains.

Cigarette smoking and the influencing factors among adolescents in a secondary school in Malaysia

BACKGROUND

Smoking has always been a huge problem in Malaysia and its surrounding nations. The purpose of this study was to determine the prevalence of cigarette smoking and to identify the influencing factors associated with smoking habits among adolescents.

MATERIALS AND METHODS

This cross-sectional study was carried out on 226 respondents, using a questionnaire which had 4 sections: socio-demographic data, personal information, family information and social information. Data was analyzed using SPSS® version 16. For categorical variables, comparisons were made using Chi-square and for numerical variables a t-test was performed.

RESULTS

The current smoker prevalence rate was 20.8% which showed a significant association between smoking and individual factors: level of knowledge on the effects of smoking (p < 0.05), significant association was seen between smoking and marital status of parents, smoking status of male siblings and various other aspects of the individuals themselves.

CONCLUSIONS

Concerted efforts involving various parties should be taken to curb or prevent this problem or the number of teenage smokers in the country will increase. This in the long run will invite problems to the well being of the adolescents themselves, their families, community and the nation as a whole.

Kidney lesions associated with systemic vasculitis: report of 25 cases in morocco

In this retrospective study, we report 25 patients with renal injury caused by systemic vasculitis. These patients were hospitalized at the department of nephrology-hemodialysis in Ibn Rochd hospital from 1985 to 1998. The mean age of the patients was 36 years (range 3 to 57 years) with male predominance (68%). The clinical presentations included cutaneous purpura in 80% of the patients, arthritis in 60% and pulmonary hemorrhage in 20%. The renal injury manifested as abnormal urinary sediment in 20 of the study patients (80%), nephritic syndrome in 14 (56%), renal failure in nine (36%). Three patients (12%) had renal failure as the initial presentation followed by the other manifestations of vasculitis. The anti-neutrophil cytoplasmic antibodies (ANCA) have been checked in only six patients of whom four were positive. Henoch-Schonlein purpura was the most common clinical sign in 11 patients (44%) followed by Behcet's disease in five (20%). The treatment was variable in type and duration but generally included corticoids alone or in combination with immunosuppressants. The prognosis of the renal injury was variable. The renal function remained stable in those with Henoch-Schonlein purpura, but was less favorable with the other etiologies with more predominance of renal failure and end-stage renal disease. This retrospective analysis of our experience is given to throw light on the pattern of vasculitis in our region.

Kinetics of bromination of safranine by peroxydisulphate ion in presence of bromide ion

Kinetics of bromination safranine by peroxydisulphate ion in presence of bromide ion has been investigated at various temperatures and ionic strengths. The rate followed first order kinetics in peroxy disulphate and bromide ion each, and zero order kinetics in safranine. A linear relation was obtained for the variation of logarithm of rate constant (log k) with the square root of ionic strength of the media (mu). The rate constants for the rate controlling step were evaluated and interpreted as a function of ionic strengths and temperatures. The values of activation parameters were also computed.

Kinetics of reaction between phenothiazine dye/methylene green and peroxydisulphate ion in presence of bromide ion

The rate of nuclear bromination was observed when the methylene green reacts with peroxydisulphate ion in presence of bromide ion. The reaction obeys zero order kinetics in the dye whereas first order kinetics in peroxodisulphate and bromide ion. The reaction was studied at various ionic strengths and temperatures to find out the effect of ionic strength on rate of nuclear brominating and energy of activation. The kinetics pertains to the rate determining stage of peroxydisulphate-bromide reaction. The study in different concentration of bromide and peroxydisulphate has shown that the rate constant increases by increasing the ionic strength and temperature of the system. The effect of ionic strength on the activation parameters was also studied.