"Shapeshifter of the mycobacterial world" : Discuss the mechanism of morphological transformation of Mycobacterium abscesses / 中华临床感染病杂志

Mycobacterium abscessesus (MAB) is the most common species of rapidly growing pathogenic nontuberculous mycobacteria (NTM). MAB is also an opportunistic pathogen with high drug resistance. The unique structure of cell wall enables it to exist in different forms and to undergo morphological transformation, making it the "shapeshifter of the mycobacterial world" , which facilitates its survival in natural environment in a saprophytic manner; and also facilitates its invasion into the host with long-term survival and being pathogenic. This article reviews research progress on the specific deformability of MAB and the mechanism associated with its phenotypic transformation; discusses the evolutionary characteristics of MAB to adapt environmental changes to provide reference for better understanding the biological characteristics and pathogenicity of MAB.

Morphologic study of the effect of iron on pseudocyst formation in Trichomonas vaginalis and its interaction with human epithelial cells

BACKGROUND Trichomonas vaginalis is the aetiological agent of human trichomoniasis, which is one of the most prevalent sexually transmitted diseases in humans. Iron is an important element for the survival of this parasite and the colonisation of the host urogenital tract. OBJECTIVES In this study, we investigated the effects of iron on parasite proliferation in the dynamics of pseudocyst formation and morphologically characterised iron depletion-induced pseudocysts. METHODS We performed structural and ultrastructural analyses using light microscopy, scanning electron microscopy and transmission electron microscopy. FINDINGS It was observed that iron depletion (i) interrupts the proliferation of T. vaginalis, (ii) induces morphological changes in typical multiplicative trophozoites to spherical non-proliferative, non-motile pseudocysts, and (iii) induces the arrest of cell division at different stages of the cell cycle; (iv) iron is the fundamental element for the maintenance of typical trophozoite morphology; (v) pseudocysts induced by iron depletion are viable and reversible forms; and, finally, (vi) we demonstrated that pseudocysts induced by iron depletion are able to interact with human epithelial cells maintaining their spherical forms. MAIN CONCLUSIONS Together, these data suggest that pseudocysts could be induced as a response to iron nutritional stress and could have a potential role in the transmission and infection of T. vaginalis.

Morphological Transformation Region II (mtrII) of Human Cytomegalovirus / 대한암학회지

PURPOSE: Human herpesviruses have been associated with the etiology of several human cancers. The role of these viruses in carcinogenesis has not yet been clarified. This study focused on identifying and characterizing the transforming potential of cloned DNA fragments from human cytomegalovirus (HCMV). MATERIALS AND METHODS: Multiple DNA fragments of HCMV were applied to cells for transformation. Morphological transforming region II (mtrII) of HCMV strain Towne has been identified to a 3.0kb XbaI-BamHI DNA fragment which was retained in transformed cells. The transforming activity was induced by a 980 bp BaII-Xho I subfragment (pBS980) containing both promoter/ regulatory elements as well as three open reading frames (ORFs), i.e., 79ORF, 83ORF, and 34ORF. The ORFs have been evaluated for transforming potential in NIH3T3 cells. RESULTS: MtrII (pBS980) has BglII restriction enzyme site which divides into two subfragments, pBS440 and pBS540, the latter has whole 83ORF, 34ORF, and fragment of 79ORF, the former has only fragment of 79ORF. Among three ORFs, 83ORF and 34ORF were not functional in transformation, because in pBS540 these ORFs were not truncated. CONCLUSION: The 79ORF (79-aa transforming peptide) has allowed a better approach to determine the role of HCMV in human carcinogenesis.