BackgroundAcanthamoeba spp. are free-living ubiquitous protozoans capable of causing Acanthamoeba meningitis/meningoencephalitis (AME) of the central nervous system in humans. Acanthamoeba spp. are divided into 20 different genotypes (T1–T20) on the basis of variation in nucleotide sequences of the 18S rRNA gene. The objective of this study was to identify the genotypes of Acanthamoeba spp. in patients of Acanthamoeba meningitis/meningoencephalitis (AME) using 18S rRNA gene-based PCR assay. The present study provides information regarding the involvement of the most prevalent and predominant genotype of Acanthamoeba spp. in Acanthamoeba meningitis/meningoencephalitis infections in India.MethodsCerebrospinal fluid (CSF) was collected from 149 clinically suspected Acanthamoeba meningitis/meningoencephalitis (AME) patients reporting to the outpatient department/causality services of the Neurosciences Centre, AIIMS, New Delhi, India during the past five years. Samples were inoculated onto 2 % non-nutrient agar plates overlaid with E. coli and incubated at 30 °C for 14 days. Among 149 suspected patients, ten were found culture-positive for Acanthamoeba spp. out of which six isolates were established in axenic culture for molecular analysis. DNA was isolated and a PCR assay was performed for amplification of the Diagnostic fragment 3 (DF3) (~280 bp) region of the 18S rRNA gene from axenic culture of six Acanthamoeba spp. isolates. Rns genotyping was performed on the basis of the variation in nucleotide sequences of DF3 region of the 18S rRNA gene.ResultsIn the phylogenetic analysis, all of the six Acanthamoeba spp. isolates were found to belong to genotype T4. The sequence homology search for these six isolates in the NCBI databank showed homology with the available strains of Acanthamoeba spp. The newly generated sequences are available in the GenBank database under accession numbers KT004416–KT004421.ConclusionsIn the present study, genotype T4 was found as the most prevalent and predominant genotype in Acanthamoeba meningitis/ meningoencephalitis infections. Hence further studies are needed to develop optimal therapeutic strategy against Acanthamoeba spp. of genotype T4 to combat against the infections.

Chlamydia trachomatis, an obligate intraocular bacteria causing trachoma, adult and neonatal inclusion conjunctivitis, was the leading cause of blindness in the last century worldwide. Improvement in socioeconomic and living conditions, availability of antibiotics, and introduction of National Trachoma Control Programmes reduced the prevalence in developed countries, but it persisted in resource-poor settings of Africa and Asia, including India. In 2016, as per the WHO report, trachoma is restricted to 42 countries, causing blindness/visual impairment in ~1.9 million people. India is one of the five countries with nearly half of total active trachoma patients. Introduction of Global Elimination of Trachoma 2020 program by the WHO, using SAFE strategy (surgery for trachomatous trichiasis; Antibiotics for C. trachomatis; Facial cleanliness; and environmental improvement) greatly reduced the prevalence, but trachoma still persists in India. Global increase in the reproductive tract infection by C. trachomatis urogenital serotypes (D-K) has led to concurrent increase in C. trachomatis eye infections. Therefore, kerato eye infections due to chlamydial infections continue to be seen in hospitals. Over the years, there have been advances in laboratory diagnostics, in understanding the pathogenesis, tissue tropism, C. trachomatis genomics, and treatment modalities. Due attention and research is still needed for the study of C. trachomatis eye infections.

No abstract

No abstract