First case series of emerging Rickettsial neonatal sepsis identified by polymerase chain reaction-based deoxyribonucleic acid sequencing.

Purpose: To detect and identify the aetiological agent in the peripheral blood from the cases of neonatal sepsis. Materials and Methods: Four neonates from geographically different regions of South India presented with signs of neonatal sepsis and all the routine clinical and laboratory investigations were performed. Blood culture by Bac T Alert 3D was negative. To establish the aetiology, polymerase chain reaction (PCR) for eubacterial genome and subsequent amplifi cation with Gram positive and Gram negative primers were performed followed by deoxyribonucleic acid (DNA) sequencing. Results: PCR for the detection of eubacterial genome was positive in all the four neonates and further amplifi cation with designed Gram positive and Gram negative primers revealed the presence of Gram negative bacteria. The amplicons were identifi ed as Orientia tsutsugamushi in three neonates and Coxiella burnetti in the other neonate. Multalin analysis was done to further characterise the strain variation among the three strains. Conclusion: PCR-based DNA sequencing is a rapid and reliable diagnostic tool to identify the aetiological agents of neonatal sepsis. This is the fi rst case series of emerging Rickettsial neonatal sepsis in India.

Isolation of a variant human adenovirus identified based on phylogenetic analysis during an outbreak of acute keratoconjunctivitis in Chennai.

Background & objectives: Though several viruses are responsible for conjunctivitis, but human adenovirus (HAdV) is by far the most common cause. Epidemic conjunctivitis causes morbidity and early detection of aetiological agent is essential in preventing spread of disease as some of serotypes of adenoviruses cause a severe form of conjunctivitis. This study was undertaken to identify the causative agent of conjunctivitis outbreak in Chennai in 2010. Methods: Conjunctival samples collected from 17 patients with conjunctivitis were subjected to virological investigations. Culture and PCR for detection of adenovirus and enterovirus were carried out. PCR positive products were further subjected for DNA sequencing. The nucleotide sequences of the hexons of isolates were analyzed by comparison with all 51 human adenovirus strains. Phylogenetic tree was constructed using DAMBE software. Results: Among 17 patients, seven were positive for adenovirus by PCR on the direct specimen, none was positive for enterovirus. Eleven of 30 conjunctival swabs showed cytopathic effect in HEp-2 cell line and were confirmed as HAdV by PCR. The DNA sequence data of the 11 isolates had equal percentage of homology with HAdV 6 and 2 on blast analysis. On phylogenetic analysis with GeneBank data of 51 adenovirus strains, 11 isolates from patients during the outbreak of conjunctivitis formed a separate clade indicating a new variant strain. Interpretation & conclusions: Based on phylogenetic analysis it was concluded that the recent conjunctivitis outbreak that occurred in Chennai was caused by a variant adenovirus strain.