Volume 21, Issue 3, 2021 July-September

Volume 21, No 3 Pages:
2021 July-September Articles: 3

Orientia tsutsugamushi: Diversity and Distribution in India: A Review

Scrub typhus is a disease caused by Orientia tsutsugamushi which is an obligate, intracellular gram-negative bacterium. It is endemic to a part of the world known as “tsutsugamushi triangle.” This extends from Japan, China, Taiwan, South Koria, Nepal, Pakistan, Papua New Guinea, Australian states of Queensland and Northern New South Wales. In India, it has been recognized for several years and the disease widely spread all over the country. The severity of scrub typhus disease has been reported to be strain dependent in humans. Orientia tsutsugamushi strains have been examined by various research tools. PCR amplification and sequencing of 56-kDa antigen gene is one of the most advanced tool in identifying O. tsutsugamushi strains and genotypes. In the present review, English-language literature for reports of Orientia tsutsugamushi genotype diversity and distribution in India was searched using PubMed and Google Scholar databases. The search terms scrub typhus or mite typhus or tropical typhus or tsutsugamushi disease or Orientia tsutsugamushi or Rickettsia tsutsugamushiwere used in combination with the term genotypes or strains or serotypes. The result of present review revealed limited Information related to genotype diversity and distribution in the country. Understanding a more detailed regional genetic diversity is required in region-specific vaccine development strategies andsero-diagnostics tools.

Study of induced half-metallic ferromagnetic property in CdO monolayer with non-metallic doping

Doping is known to be an efficient way of altering the properties of materials. We have studied the structural, electronic and magnetic properties of non-metallic element (B, C and N)-doped CdO monolayer based on spin-polarized density function theory within the generalized gradient approximation (GGA) as revised for solids by Perdew, Burke and Ernzerhof (PBE-sol). Substituting B, C and N in O site with one atom in CdO monolayer induces spin polarized localized states in the gap or near the valence band and exhibit local magnetic moments ~ 1 μΒ, ~ 2 μΒ and ~ 1 μΒ respectively. It is found that the magnetic states in these doped systems are associated with the difference between the electronegativity of the dopant and the anion in the host. Our study shows that non-metal doped CdO is a promising candidate for novel nano-materials for future applications.

Study of potable water quality in peripheral areas of Aizawl city in Mizoram

Potable water quality and quantity is one of the most important topics of study in today’s world. More and more techniques for efficient use of water are required throughout the world, especially in developing countries like India. The present study was conducted to analyse the quality of potable water sources use by the citizens of Aizawl district in the state of Mizoram, India. Number of samples was collected from surrounding areas of Greater Aizawl in pre cleaned polyethylene bottles as recommended in the WHO standards and recommendations. Various physico-chemical properties (pH, turbidity, total hardness, chloride, free chlorine, iron, nitrate and total dissolved solids) were studied. The samples were analyzed in the field using handheld meters for pH, turbidity, total hardness and TDS and were then also analyzed in the laboratory to confirm the field results. The other chemical parameters were tested in the laboratory using standard and recommended techniques. The pH values ranged from 6.48 to 7.54. TDS values ranged from 30 to 430ppm. Total hardness ranged from 30 to 60 mg/l. Chloride content in the samples was found to be between the values of 15.5 to 80 ppm. Iron and nitrate were found only in trace quantities in all the samples. In surrounding areas of the city, proper development of perennial springs would serve as the main source of water supply to the local population. Some samples which contained higher concentrations of chloride could have been contaminated from sewage water or waste water leakage. Other than that, the quality of water was within the limits of WHO standards.