Effect of heat stress during flowering and pod formation in pea (Pisum sativum L.).

Heat stress is a major constraint of yield in grain legumes including peas. Increasing global warming and human population now urge to develop climate resilient varieties. The present experiment was conducted over 2 years to evaluate the heat tolerance of 211 pea genotypes. In the present study, the field pea genotypes showed a wide variation for reproductive stage heat stress (RSHS) quantitative traits. Significant positive correlations were found between no. of seeds per plant and no. of pods per plant; seed diameter (mm) and 25-seed weight (g) in heat tolerant as well as heat susceptible genotypes. Principal component analysis revealed two major principal components contributed approximately 91% of total variations and heat tolerant and susceptible genotypes separately formed two major clusters. Stepwise multiple regression analysis revealed that no. of seeds per plant was the best predictor for no. of pods per plant. On the basis of four RSHS traits, the most prominent heat tolerant pea genotypes identified in the present study JP-625, IARI-2877, PMR-38 II, EC-318760, EC-328758 and IARI-2904 would better combat RSHS and provide yield stability under changing climatic conditions.

Evaluation of custom multiplex real - time RT - PCR in comparison to fast - track diagnostics respiratory 21 pathogens kit for detection of multiple respiratory viruses.

BACKGROUND: Severe acute respiratory infections in children can be fatal, rapid identification of the causative agent and timely treatment can be life saving. Multiplex real time RT-PCR helps in simultaneous detection of multiple viruses saving cost, time and labour. Commercially available multiplex real time RT-PCR kits are very expensive. Therefore the aim of the present study was to develop a cost effective multiplex real time RT-PCR for the detection of 18 respiratory viruses and compare it with an in-vitro diagnostics approved Fast Track Diagnostic Respiratory Pathogens 21 Kit (FTD). METHODS: Nasopharyngeal aspirates and throat swabs were collected and processed for extraction of nucleic acid using an automated extraction system and multiplex real time RT-PCR was performed using the FTD kit and a custom assay on 356 samples. RESULTS: Custom and FTD assays detected one or more respiratory viruses in 268 (75.29 %) and 262 (73.60 %) samples respectively. The concordance between the custom assay and the FTD assay was 100 % for HCoV OC43, HCoV 229E, HPIV-1, HPIV-2, HBoV, HPeV, Flu A, and Influenza A(H1N1)pdm09 and 94.66 - 99.71 % for the remaining viruses; Flu B (99.71 %), HRV (99.71 %), HPIV-3 (98.87 %), HPIV-4 (99.43 %), HCoV NL63 (99.71 %), HMPV A/B (99.71 %), RSV A/B (94.66 %), EV (98.31 %), HCoV HKU1 (99.71 %), HAdV (99.71 %). Major discrepancy was observed for RSV A/B, which was over detected in 18 samples by the custom assay as compared to the FTD assay. The custom assay was much cheaper than the FTD assay and the time taken was only 29 min more. CONCLUSION: The custom primer and probe mix was found to be comparable to the FTD assay with good concordance but was much cheaper and the time taken for reporting was only 29 min more. The low cost custom multiplex RT-PCR can be a useful alternative to the costly FTD kit for rapid identification of viral aetiology in resource limited settings.

Cluster of differentiation 4+ T-cell counts and human immunodeficiency virus-1 viral load in patients coinfected with hepatitis B virus and hepatitis C virus.

BACKGROUND: Coinfections of human immunodeficiency virus (HIV) with hepatitis viruses may affect the progress of disease and response to therapy. OBJECTIVES: To study the incidence of hepatitis B virus (HBV) and hepatitis C virus (HCV) coinfections in HIV-positive patients and their influence on HIV-1 viral load and cluster of differentiation 4+ (CD4+) T-cell counts. MATERIALS AND METHODS: This pilot study was done on 179 HIV-positive patients attending antiretroviral therapy (ART) centre. Their blood samples were tested for HIV-1 viral load, CD4+ T-cell counts, hepatitis B surface antigen, anti-HCV antibodies, HBV DNA and HCV RNA polymerase chain reaction. RESULTS: Among the 179 patients, 7.82% (14/179) were coinfected with HBV and 4.46% (8/179) with HCV. Median CD4+ T-cell count of HIV monoinfected patients was 200 cells/µl and viral load was 1.67 log10 copies/µl. Median CD4+ T-cell counts of 193 cells/µl for HBV (P = 0.230) and 197 cells/µl for HCV (P = 0.610) coinfected patients were similar to that of HIV monoinfected patients. Viral load was higher in both HBV and HCV infected patients but statistically significant only for HCV (P = 0.017). Increase in CD4+ T-cell counts and decrease in HIV-1 viral load in coinfected patients on 2 years of ART were lower than that in HIV monoinfected patients. CONCLUSION: HBV/HCV coinfected HIV patients had similar CD4+ T-cell counts as in HIV monoinfected patients, higher HIV viral load both in chemo-naive patients and in those on ART as compared to HIV monoinfected patients. However, this study needs to be done on a large scale to assess the impact of coinfection on CD4 count and HIV viral load with proper follow-up of patients every 6 months till at least 2 years.

Trends of respiratory syncytial virus sub-types in children hospitalised at a tertiary care centre in Jaipur during 2012-2014.

Respiratory syncytial virus (RSV) causes high mortality and morbidity in infants. The study was planned to determine the trends of RSV sub-types in hospitalised children. Nasopharyngeal aspirate and throat swabs were collected from the hospitalised children up to 5 years of age. Viral nucleic acid was extracted using easyMAG automated extraction system, and real-time reverse transcription polymerase chain reaction was performed. Total positivity for RSV was found to be 25.40%, predominantly for RSV B (20.03%), followed by RSV A (2.90%) and RSV AB mixed infections (2.47%). Palivizumab prophylaxis can be planned to be given to infants from post-monsoon to end of winter.

Aetiological study of viruses causing acute encephalitis syndrome in North West India.

CONTEXT: Acute encephalitis syndrome (AES) is a serious public health problem, caused mainly by viruses. However, the profile of viruses causing AES in Rajasthan is not well characterised. AIMS: The present study was undertaken to identify the viruses causing AES and develop diagnostic algorithm so as to help in improved diagnosis, treatment, prevention and control. SETTINGS AND DESIGN: The present study is a hospital-based descriptive, observational study. Samples were processed at Grade-1 DHR/ICMR Viral Research and Diagnostic Laboratory at SMS, Jaipur. SUBJECTS AND METHODS: Cerebrospinal fluid (CSF) samples were processed for IgM antibody detection by enzyme-linked immunosorbent assay (ELISA) for mumps virus (MPV), measles virus (MV), Rubella virus (RV), Japanese encephalitis virus (JEV), West Nile virus (WNV) and Dengue virus using commercial kits. Nucleic acid was extracted from CSF using automated extraction system. Real-time polymerase chain reaction was done using specific primers and probes for Herpes simplex virus (HSV), Varicella-zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV) and enterovirus (EV). STATISTICAL ANALYSIS USED: Statistical analysis was done using ANOVA. RESULTS: Among 3088 patients, 702 (22.7%) patients were positive for one or more viruses. HSV (261;8.45%) was the most common followed by EBV (173;5.6%), VZV (97;3.1%), CMV (68;2.2%), EV (32;1.03%), MPV (27;0.9%), DV (28;0.9%), MV (19;0.6%) and RV (6;0.2%). CONCLUSIONS: AES occurred sporadically in Rajasthan, samples should be tested first for herpes group of viruses followed by EV or/and for arboviruses depending on season or measles, mumps and RVs in children.

Distribution and Trends of Human Parainfluenza Viruses in Hospitalised Children.

OBJECTIVE: To study the distribution of Human Parainfluenza viruses (HPIV) 1-4 and their trends in children ≤5 y of age, hospitalised at a tertiary care centre, Jaipur and co-infection with other respiratory viruses. METHODS: Nasopharyngeal aspirate and throat swabs were collected and processed for extraction of nucleic acid using automated extraction system and real time RT-PCR was performed using primers and probes specific to HPIV 1-4 and other respiratory viruses on 743 samples. RESULTS: Total positivity for Parainfluenza viruses 1-4 was found to be 69/743 (9.28 %), of which 50/533 (9.38 %) were boys and 19/210 (9.05 %) girls. Predominance of HPIV- 3 was observed [41/743 (5.52%)] followed by HPIV-1 in 13/743 (1.75%), HPIV-4 in 10/743 (1.34%) and HPIV-2 in 5/743 (0.67%) patients. Maximum positivity was observed in age group 25-36 mo (12.98%) followed by 13-24 mo group (11.96%). HPIVs were found to be circulating round the year and each year. Co-infections with other respiratory viruses were observed in 22/69 (31.88%) of HPIV positive patients. CONCLUSIONS: All the four types of HPIV were found to be circulating in the index population during all the three years, predominantly during post monsoon and winter seasons. HPIV vaccination should be targeted for all types.