ABSTRACT
During evolution Orientia tsutsugamushi became a smarter obligate bacterium to establish as intracellular pathogens. O. tsutsugamushi is a human pathogenic bacterium responsible for 1 billion infections of scrub typhus. Several novel mechanisms make this bacterium unique (cell wall, genetic constitutions, secretion system, etc.). In 2007, O. tsutsugamushi Boryong was pioneer strain for whole-genome sequencing. But the fundamental biology of this bacterial cell is a mystery till date. The unusual biology makes this organism as model for host cell interaction. Only a few antibiotics are effective against this intracellular pathogen but emergence of less susceptibility toward antibiotics make the situation alarming. The review was captivated to highlight the unusual aspects of adaptation, antibiotics, and drugs beyond antibiotics.
Subject(s)
Anti-Bacterial Agents , Orientia tsutsugamushi , Scrub Typhus , Orientia tsutsugamushi/genetics , Orientia tsutsugamushi/drug effects , Scrub Typhus/microbiology , Scrub Typhus/drug therapy , Anti-Bacterial Agents/pharmacology , Humans , Adaptation, Physiological , AnimalsABSTRACT
Dengue (DEN) is the most common cause of mosquito-borne endemic viral diseases in the tropical and subtropical countries. DEN outbreaks associated with multiple dengue virus (DV) serotypes have been regularly reported in different parts of India. This study was done during DEN outbreaks in 2015 to 2016 in UP and Bihar where DEN-2 was found as the only prevalent serotype. DV-2 was the only serotype amplified in serotype-specific reverse-transcription polymerase chain reaction from sera of 210 (65.21%) out of 322 DV NS1 antigen-positive patients. Further genetic analysis based on full-length envelope (E) protein sequence derived from patient's sera as well as DV isolate showed the circulation of lineages I and III of DV-2 cosmopolitan genotype during 2015 and lineage II during 2016. Finally, the phylogenetic analysis using the E gene sequence revealed that these DV-2 strains have a close genetic relationship with the recently reported DV-2 genotypes from DEN outbreaks reported from different parts of north India. These results showed the circulation of cosmopolitan genotype of DV-2 in eastern Uttar Pradesh and western Bihar, India. The genetic database generated on circulating DV strains in this study will be useful as reference for disease surveillance and strengthening laboratory diagnosis protocols.
