Bacteriophages are a promising alternative for curtailing infections caused by multi drug resistant (MDR) bacteria. The objective of the present study is to evaluate phage populations from water bodies to inhibit planktonic and biofilm mode of growth of drug resistant Klebsiella pneumoniae in vitro and curtail planktonic growth in vivo in a zebrafish model. Phage specific to K. pneumoniae (MTCC 432) was isolated from Ganges River (designated as KpG). One-step growth curve, in vitro time kill curve study and in vivo infection model were performed to evaluate the ability of phage to curtail planktonic growth. Crystal violet assay and colony biofilm assay were performed to determine the action of phages on biofilms. KpG phages had a greater burst size, better bactericidal potential and enhanced inhibitory effect against biofilms formed at liquid air and solid air interfaces. In vitro time kill assay showed a 3 log decline and a 6 log decline in K. pneumoniae colony counts, when phages were administered individually and in combination with streptomycin, respectively. In vivo injection of KpG phages revealed that it did not pose any toxicity to zebrafish as evidenced by liver/brain enzyme profiles and by histopathological analysis. The muscle tissue of zebrafish, infected with K. pneumoniae and treated with KpG phages alone and in combination with streptomycin showed a significant 77.7% and 97.2% decline in CFU/ml, respectively, relative to untreated control. Our study reveals that KpG phages has the potential to curtail plantonic and biofilm mode of growth in higher animal models.
The variant of Concern(VOC), Omicron is the predominant variant circulating throughout the world of the SARS COV2 pandemic during the third wave including India. The World Health Organisation has designated this highly mutated variant as a VOC due to its high transmissibility and risk of reinfection. Whole-genome sequencing and analysis were performed for SARS-CoV2 PCR positive samples between Dec21 to Jan22. From the 133 omicron variants detected, genomic analysis was carried out by contextualizing them with 1586 complete genomes of Omicron from India obtained from GISAID.The Omicron variant prevalence in India has increased in a log phase within 3 months in most of the metropolitan cities. The sublineage BA.1 was first observed in the country, while the BA.2 sublineage was introduced to Delhi in the mid of December 2021. The two outbreaks observed were of BA.2 variant and were observed to spread to multiple cities in a short time. The rapid spread and specific mutations in the outbreak samples of Omicron indicate that the variant is highly transmissible when compared to previous variants. The study shows the importance of genomic sequence to identify the emergence of clusters and take actions to prevent further spreading events.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.