Measles virus (MV) is the causative agent for acute measles and subacute sclerosing panencephalitis (SSPE). Although numerous mutations have been found in the MV genome of SSPE strains, the mutations responsible for the neurovirulence have not been determined. We previously reported that the SSPE Osaka-2 strain but not the wild-type strains of MV induced acute encephalopathy when they were inoculated intracerebrally into 3-week-old hamsters. The recombinant MV system was adapted for the current study to identify the gene(s) responsible for neurovirulence in our hamster model. Recombinant viruses that contained envelope-associated genes from the Osaka-2 strain were generated on the IC323 wild-type MV background. The recombinant virus containing the M gene alone did not induce neurological disease, whereas the H gene partially contributed to neurovirulence. In sharp contrast, the recombinant virus containing the F gene alone induced lethal encephalopathy. This phenotype was related to the ability of the F protein to induce syncytium formation in Vero cells. Further study indicated that a single T461I substitution in the F protein was sufficient to transform the nonneuropathogenic wild-type MV into a lethal virus for hamsters.

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Background: Largest organ of human body, the skin, is colonized by millions of microorganisms, most of which are not only harmless but also beneficial to the host. Human skin microbes depend upon geographical variations, ethnicity and various host factors. Despite several studies on human skin microbiota in various parts of the globe, it has not been studied in Nepalese population. Aims and Objective: To identify skin bacterial normal flora in different ethnic groups residing in different altitude of Nepal. Materials and Methods: We cultured skin swabs of 166 randomly selected volunteers belonging to 10 major ethnic groups from 3 distinct geographical altitudes of Nepal, viz. Bharatpur (415 m from sea level), Kathmandu (1,400 m from sea level) and Lukla (2,860 m from sea level). The isolated organisms were characterized and tested for their susceptibility against different antibiotics. Results: Altogether 231 bacterial isolates were characterized from 166 skin samples. Among them, 140 isolates (60.60 %) were Gram positive and 91 isolates (39.40 %) were Gram negative bacteria. Staphylococcus aureus (35.49%) was the most dominant skin bacterial flora followed by Escherichia coli (22.51%) and Streptococcus spp. (17.75%). Medium altitude Kathmandu exhibited the highest growth (120 isolates) followed by low land Bharatpur (66 isolates) and high land Lukla (51 isolates) which is statistically significant (p value =0.0124). Theantibiotic susceptibility testing against 14 antibiotics exhibited the Gram positive isolates were the most sensitive to Imipenem (94.93 %) whereas the least sensitive to Cephalexin (31.36 %) and the Gram negative isolates were the most sensitive to Amikacin (100%) whereas the least sensitive to Amoxycillin (28.57 %). Conclusion: Our data indicates that the skin bacterial normal flora; which is directly exposed to external environment; has significant relationship with altitudes where individuals live. The result desires further study for the adaptability of normal flora found in different altitudes. Some bacterial commensals were found resistant even against new generations of antibiotics as well, and hence can cause life-threatening infections if they happen to cross the skin physical barrier.

The Schwarz FF-8 (FF-8) and AIK-C measles virus vaccine strains are currently used for vaccination in Japan. Here, the complete genome nucleotide sequence of the FF-8 strain has been determined and its genome sequence found to be remarkably similar to that of the AIK-C strain. These two strains are differentiated only by two nucleotide differences in the phosphoprotein gene. Since the FF-8 strain does not possess the amino acid substitutions in the phospho-and fusion proteins which are responsible for the temperature-sensitivity and small syncytium formation phenotypes of the AIK-C strain, respectively, other unidentified common mechanisms likely attenuate both the FF-8 and AIK-C strains.