Averting transmission: A pivotal target to manage amoebiasis

Amoebiasis is a parasitic infectious disease caused by the enteric protozoan Entamoeba histolytica, a leading basis of deaths accounted to parasites, succeeding malaria and schistosomiasis. Conventional treatment methodologies used to deal with amoebiasis mainly rely on the administration of anti‐amoebic compounds and vaccines but are often linked with substantial side‐effects on the patient. Besides, cases of development of drug resistance in protozoans have been recorded, contributing further to the reduction in the efficiency of the treatment. Loopholes in the efficacious management of the disease call for the development of novel methodologies to manage amoebiasis. A way to achieve this is by targeting the essential metabolic processes of ‘encystation’ and ‘excystation’, and the associated biomolecules, thus interrupting the biphasic life cycle of the parasite. Technologies like the CRISPR‐Cas9 system can efficiently be exploited to discover novel and essential molecules that regulate the protozoan's metabolism, while efficiently manipulating and managing the known drug targets, leading to an effective halt and forestall to the enteric infection. This review presents a perspective on these essential metabolic processes and the associated molecules that can be targeted efficaciously to prevent the transmission of amoebiasis, thus managing the disease and proving to be a fruitful endeavour.     

Molecular characterization and pathogenicity of a carrot (Daucus carota) infecting begomovirus and associated betasatellite from India

The yellow mosaic pattern and shortening of leaf petiole are common disease symptoms associated with begomovirus infection in carrot. DNA from field infected carrot leaves was analyzed by rolling circle amplification and sequencing. The results established the presence of ageratum enation virus (AEV), which is referred to here as ageratum enation virus-carrot (AEV-Car). Symptomatic ageratum (Ageratum conyzoides) plants, growing adjacent to the carrot fields, also showed the presence of AEV (AEV-Age). Ageratum yellow leaf curl betasatellite (AYLCB) was also detected in the AEV infected carrot and ageratum samples. AEV-Car and AEV-Age are 95–97% identical in their DNA sequences, represent groups of isolates from the respective plant hosts (carrot and ageratum). Agroinoculation using infectious clones of AEV-Car plus AYLCB or AEV-Age plus AYLCB in carrot, ageratum, tobacco (Nicotiana tabacum) and tomato (Solanum lycopersicum) produced yellow mosaic and curling symptoms in leaves of inoculated plants. Agroinoculation of the two isolates together, along with the betasatellite (AEV-Car plus AEV-Age plus AYLCB) resulted in the enhancement of symptoms in comparison to the plants inoculated with single isolate. Plants with more severe symptoms showed a higher level of viral DNA accumulation, suggesting synergistic interactions between the two isolates of AEV.     

Comparative Evaluation of PCR and Imprint Smear Microscopy Analyses of Skin Biopsy Specimens in Diagnosis of Macular,Papular, and Mixed Papulo-Nodular Lesions of Post-Kala-Azar Dermal Leishmaniasis

Diagnosis of post-kala-azar dermal leishmaniasis (PKDL), particularly the macular form, is difficult when based on microscopy. This study compared the results of nested PCR (91.9% positive samples) with imprint smear microscopy (70.9% positive samples) for 62 PKDL samples. We found that nested PCR, which indicated 87.5% positivity for the macular lesions, compared to 41.6% positivity by imprint smear microscopy, is an efficient method for early diagnosis of PKDL.     

The emerging role of microRNAs in regulating immune and inflammatory responses in the lung

Chronic inflammatory diseases of the lung are leading causes of morbidity and mortality worldwide. Many of these disorders can be attributed to abnormal immune responses to environmental stimuli and infections. As such, understanding the innate host defense pathways and their regulatory systems will be critical to developing new approaches to treatment. In this regard, there is increasing interest in the role of microRNAs (miRNAs) in the regulation of pulmonary innate host defense responses and the inflammatory sequelae in respiratory disease. In this review, we discuss recent findings that indicate an important role for miRNAs in the regulation in mouse models of various respiratory diseases and in host defense against bacterial and viral infection. We also discuss the potential utility and limitations of targeting these molecules as anti-inflammatory strategies and also as a means to improve pathogen clearance from the lung.     

Hepatitis E virus antigen detection as an early diagnostic marker: Report from India

Hepatitis E virus (HEV) is implicated in many outbreaks of viral hepatitis in the Indian subcontinent. The conventional diagnosis of such outbreaks rests on the detection of anti‐HEV IgM antibodies. However, IgM antibodies develop after 4–5 days of infection. An early‐diagnostic marker is imperative for timely diagnosis of the outbreak and also initiation of control measures. This study aimed to determine the use of hepatitis E virus antigen detection as an early diagnostic marker in an outbreak in comparison to anti‐HEV IgM and RT‐PCR analyses. Forty samples were collected during a suspected outbreak of viral hepatitis due to HEV. A total of 36 samples were positive for one or more HEV markers. The positivity for anti‐HEV IgM, HEV antigen, and RT‐PCR was 91.6%, 69.4%, and 47.2% respectively. RT‐PCR and HEV antigen detection gave the highest positive results (100%) in the first 3 days of illness. Positive HEV PCR declined to 54% by Days 4–7, whereas HEV antigen and IgM detection were 88% and 100%, respectively. Sequencing of representative HEV samples indicated that the strains responsible for this outbreak belonged to genotype I, subtype 1a. HEV antigen was found to be an early diagnostic marker of acute infection. HEV antigen was detected in three additional cases in the early phase (1–3 days), and they had no detectable anti‐HEV IgM antibodies. These three samples were also positive for HEV RNA. After Day 7, anti‐HEV IgM was the main diagnostic indicator of infection. J. Med. Virol. 85:823–827, 2013. © 2013 Wiley Periodicals, Inc.