Biology subjects

Varsha, V.

Publications and source records attributed to Varsha, V..

2 recordsLinked to original sources

bioRxiv2020

Detection of NDM-1, VIM-1 and AIM-type Metallo-beta-lactamase genes in Gram-negative bacteria isolated from clinical samples in Tamil Nadu

The distribution of carbapenem-resistant Gram-negative bacteria has become an increasing public health concern in India. The aim of this study was to investigate the prevalence of carbapenem-resistant bacteria isolated from the clinical samples in Tamil Nadu, India. A total of 126 non-repetitive Gram-negative bacteria were taken for this study. The susceptibility to meropenem was determined by Minimum Inhibitory Concentration (MIC) by broth micro-dilution. The phenotypic resistance screening such as MHT (Modified Hodge test), EDTA disk synergy and CIM (carbapenem inactivation method) were performed. A multiplex PCR was used for the detection of carbapenemase-encoding genes. Among the 126 isolates studied, 82 (65.07%) meropenem-resistant isolates were identified by MIC. A total of 18 (21.9%) isolates were found to be positive for Metallo-{beta}-Lactamase production through EDTA synergy test. None of the isolates were carbapenemase producer by MHT and CIM. The isolates identified with resistance genes (8/82) were blaNDM-1 in two Klebsiella sp., two P. aeruginosa and one A. baumannii, blaVIM-1 in one P. aeruginosa and blaAIM-1 in one P. aeruginosa and one A. baumannii. The study showed the distribution and increase of carbapenem-resistant bacteria in the study region. Therefore, constant monitoring and effective elimination should be focused to reduce the spread of carbapenem-resistant isolates.

microbiology↗

bioRxiv2019

Phenotyping and molecular marker analysis of WH1105 and Kharchia 65 backcrosses and F4 progenies for salinity tolerance

Soil salinity is a worldwide adverse environmental factor for crop productivity and quality in arid, semiarid and coastal areas. In India, approximately 8.5 million hectare of land area is affected by high salinity (EC [≥] 5 dS m-1). Development of salinity tolerant varieties through marker assisted breeding is most efficient and effective strategy for management of soil salinity. WH 1105 is widely cultivated wheat variety with many agronomically superior qualities but is affected by soil salinity. Two genes (Nax1 and Nax2) for salinity tolerance were introgressed from Kharchia 65 into the genetic background of WH 1105 through marker assisted backcross breeding. BC1F3, BC2F2 and F4 generations of the cross WH1105 x Kharchia 65 were evaluated for various morphological traits under initial salt stress condition. On the basis of phenotypic and genotypic variations 44 high yielding plants were selected from the cross. Out of 178 SSRs tested, 30 were found polymorphic for background selection of the foreground selected plants. Cluster tree analysis of parents and all the three generations showed that all the selected plants were inclined toward recurrent parent (WH 1105) indicating higher similarity with the recurrent parent. Four plants were selected as high grain yielding and salt tolerant. These plants could be further backcrossed with the recurrent parent to develop salt tolerant wheat lines.

plant biology↗