Insight into Population Structure and Drug Resistance of Pediatric Tuberculosis Strains from China and Russia Gained through Whole-Genome Sequencing

This study aimed to determine phenotypic and genotypic drug resistance patterns of Mycobacterium tuberculosis strains from children with tuberculosis (TB) in China and Russia, two high-burden countries for multi/extensively-drug resistant (MDR/XDR) TB. Whole-genome sequencing data of M. tuberculosis isolates from China (n = 137) and Russia (n = 60) were analyzed for phylogenetic markers and drug-resistance mutations, followed by comparison with phenotypic susceptibility data. The Beijing genotype was detected in 126 Chinese and 50 Russian isolates. The Euro-American lineage was detected in 10 Russian and 11 Chinese isolates. In the Russian collection, the Beijing genotype and Beijing B0/W148-cluster were dominated by MDR strains (68% and 94%, respectively). Ninety percent of B0/W148 strains were phenotypically pre-XDR. In the Chinese collection, neither of the Beijing sublineages was associated with MDR/pre-XDR status. MDR was mostly caused by low fitness cost mutations (rpoB S450L, katG S315T, rpsL K43R). Chinese rifampicin-resistant strains demonstrated a higher diversity of resistance mutations than Russian isolates (p = 0.003). The rifampicin and isoniazid resistance compensatory mutations were detected in some MDR strains, but they were not widespread. The molecular mechanisms of M. tuberculosis adaptation to anti-TB treatment are not unique to the pediatric strains, but they reflect the general situation with TB in Russia and China.

The effect of low alcohol consumption during pregnancy on the lipid peroxidation-antioxidant defense system of women, their alcohol-exposed infants, and growth, health, and developmental outcomes

BACKGROUND

Few studies have examined the effects of low-dose alcohol consumption on the "lipid peroxidation-antioxidant defense" (LPO-AOD) system of mothers and infants, and on infant growth and development. This study examined effects of alcohol consumption on the LPO-AOD system of pregnant women and newborns and infant development.

METHODS

A total of 209 pregnant women were recruited for this prospective study at the first prenatal visit and followed until delivery: 112 consumed alcohol and 97 reported no alcohol use during pregnancy. Infants were evaluated at birth, and at 6 and 12 months of age. The study controlled for the confounding effect of maternal smoking.

RESULTS

Biomarkers of lipid peroxidation, for example, thiobarbituric acid reactants, were higher and the activity of the antioxidant defense system was lower in drinkers and their infants. Higher rates of pathological conditions and slower postnatal growth were observed among infants who were prenatally exposed to alcohol. Low-dose alcohol use and tobacco smoking were associated with lower postnatal infant growth trajectories, resulting in restricted growth at 6 and 12 months among infants born to mothers who drank or smoked during pregnancy. Alcohol had a broad effect on the infant and maternal LPO-AOD system, while the effect of smoking was limited in this study to maternal glutathione peroxidase.

CONCLUSIONS

Small amounts of alcohol consumed during pregnancy are associated with dysfunction of the LPO-AOD system and development of oxidative stress in women and their children. Identification and preventive interventions are needed for pregnant women who use alcohol in any amount.

Antioxidant status in peri- and postmenopausal women

Menopause is a risk factor for oxidative stress. The aim of our study is to assess antioxidant system parameters (α-tocopherol, retinol, reduced glutathione, total antioxidant activity) in peri- and postmenopausal women. The antioxidant defense activity by estimation of total antioxidant activity, α-tocopherol, retinol, oxidized and reduced glutathione levels was studied in women of reproductive age (n=37), in perimenopausal (n=41) and postmenopausal women (n=41). In our study we used spectrofluorofotometer methods. Statistical analysis was performed by non-parametric tests with p<0.05 as the level of significance. The results of our study showed the decrease of α-tocopherol and retinol concentrations and the increase of oxidized glutathione level in blood serum both in perimenopausal and postmenopausal women, the total antioxidant activity of blood serum was decreased in postmenopausal women only. The results of our study demonstrate that decrease of antioxidant defense system resources depends on the menopausal phase.

Fatal Cowpox Virus Infection in Captive Banded Mongooses (Mungos mungo)

Cowpox virus infections have been described in various domestic and exotic animal species. This report is the first on an outbreak of fatal generalized cowpox virus infection among captive banded mongooses ( Mungos mungo, suborder Feliformia). All animals of a colony of 8 mongooses showed a fulminant course of disease. The whole population died (n=7) or was euthanized (n=1) within 11 days. Postmortem examinations were performed on 4 animals. All animals showed extensive necrotizing inflammation of retropharyngeal lymph nodes, typical poxviral skin lesions, and multiple necrotic foci in liver and spleen. Three animals exhibited an ulcerating stomatitis. Pulmonary lesions, a common feature of fatal cowpox virus infections in other feliform species, were not obvious. Histopathologically, characteristic cytoplasmic inclusion bodies were detected in all affected organs but the spleen. Based on transmission electron microscopy and cell culture, Orthopoxvirus was identified as the etiology. The virus was further characterized by polymerase chain reaction and sequence analysis, identifying it as cowpox virus. A survey in the habitat suggests wild brown rats ( Rattus norvegicus) as the most likely source of infection.

Filoviruses: Interactions with the host cell

The highly pathogenic filoviruses, Marburg and Ebola virus, are difficult to handle and knowledge of the interactions between filoviruses and their host cells remained enigmatic for many years. Two developments were crucial for the presented advances in our understanding of the cell biology of filoviruses, which is still fragmentary. On the one hand, the number of high containment laboratories increased where handling of the highly pathogenic filoviruses is possible. On the other hand, molecular biological tools have been developed that allow investigation of certain aspects of filoviral replication under normal laboratory conditions which considerably accelerated research on filoviruses. This review describes advances in understanding the interactions between host cells and filoviruses during viral attachment, entry, transcription, assembly and budding.

Radiotherapy of skin carcinomas of the pinna: a study of 115 lesions in 108 patients

BACKGROUND

The possibility of treating skin carcinomas of the pinna with radiotherapy is somewhat under discussion and scarcely known. Therefore the aim of the study was to evaluate the effectiveness and safety of dermatologic radiotherapy in a series of patients affected by basal or squamous cell carcinoma of the pinna.

METHODS

A retrospective study was performed on 108 patients affected by 115 carcinomas of the pinna (99 basal cell carcinomas, 16 squamous cell carcinomas) without involvement of the external auditory canal. Radiotherapy was performed with kilovoltage techniques (55-120 kV) and the total doses administered ranged from 45 to 70 Gy (105 Gy in one case only), with different fractionations.

RESULTS

The mean follow-up was 28.80 months. Complete remission was obtained in 111 lesions (96.52%) and partial remission in one (0.87%), as evaluated 1 month after the end of radiotherapy. No response was observed in two lesions (1.74%). The response was not evaluable in one lesion (0.87%). During follow up a relapse was observed in 12 lesions (all basal cell carcinomas): nine central and three marginal to the irradiation field. The 5-year cure-rate from the end of radiotherapy was 78%. The cosmetic results were evaluated as good or acceptable in 88.28% of lesions. No complications nor sequelae to the treatment were observed.

CONCLUSIONS

The results obtained confirm the possibility of treating epithelial skin neoplasms of the pinna with dermatologic radiotherapy, which can afford high-remission percentages without damaging cartilaginous tissue.

Site directed mutagenesis of the carboxyl terminus of human cytomegalovirus glycoprotein B leads to attenuation of viral growth in cell culture

A viable human cytomegalovirus (HCMV) mutant was generated harbouring a glycoprotein B (gB) in which the carboxyl-terminal amino acids DRLRHR (aa 885-900) were changed to AALREE. Characterization of the phenotype of the recombinant virus revealed significant reduction of infectious progeny release and only moderate reduction of viral DNA replication indicating its diminished specific infectivity. This observation was in line with immunogold labeling of extracellular virions demonstrating that the amount of gB protein was markedly reduced in the envelope of the mutant virus. Our results suggest that the conserved carboxyl-terminus of the gB molecule is critical for HCMV maturation.

Phosphorylation of Marburg virus VP30 at serines 40 and 42 is critical for its interaction with NP inclusions

The Marburg virus (MBGV) nucleocapsid complex is composed of four viral proteins (NP, L, VP35, and VP30) and the negative-strand nonsegmented genomic RNA. NP, L, and VP35 are functionally conserved among the order Mononegavirales, whereas VP30, a phosphoprotein, represents a filovirus-specific nucleocapsid protein. In the present paper, we have characterized the localization and function of VP30 phosphorylation. The main phosphorylation sites are represented by seven serine residues in the region of amino acid 40 to 51 of VP30. Additionally, trace amounts of phosphothreonine were detected. Substitution of serine residues 40 and 42 by alanine abolished the interaction of VP30 with NP-induced inclusion bodies, which contain nucleocapsid-like structures formed by NP. Substitution of the other phosphoserine residues had little effect on this interaction. Replacement of the introduced alanine residues 40 and 42 by aspartate restored the interaction between VP30 and the NP inclusions pointing to the importance of negative charges at these particular positions.

Sorting of Marburg virus surface protein and virus release take place at opposite surfaces of infected polarized epithelial cells

Marburg virus, a filovirus, causes severe hemorrhagic fever with hitherto poorly understood molecular pathogenesis. We have investigated here the vectorial transport of the surface protein GP of Marburg virus in polarized epithelial cells. To this end, we established an MDCKII cell line that was able to express GP permanently (MDCK-GP). The functional integrity of GP expressed in these cells was analyzed using vesicular stomatitis virus pseudotypes. Further experiments revealed that GP is transported in MDCK-GP cells mainly to the apical membrane and is released exclusively into the culture medium facing the apical membrane. When MDCKII cells were infected with Marburg virus, the majority of GP was also transported to the apical membrane, suggesting that the protein contains an autonomous apical transport signal. Release of infectious progeny virions, however, took place exclusively at the basolateral membrane of the cells. Thus, vectorial budding of Marburg virus is presumably determined by factors other than the surface protein.

Clustering of apoptotic cells via bystander killing by peroxides

Clustering of apoptotic cells is a characteristic of many developing or renewing systems, suggesting that apoptotic cells kill bystanders. Bystander killing can be triggered experimentally by inducing apoptosis in single cells and may be based on the exchange of as yet unidentified chemical cell death signals between nearby cells without the need for cell-to-cell communication via gap junctions. Here we demonstrate that apoptotic cell clusters occurred spontaneously, after serum deprivation or p53 transfection in cell monolayers in vitro. Clustering was apparently induced through bystander killing by primary apoptotic cells. Catalase, a peroxide scavenger, suppressed bystander killing, suggesting that hydrogen peroxide generated by apoptotic cells is the death signal. Although p53 expression increased the number of apoptoses, clustering was found to be similar around apoptotic cells whether or not p53 was expressed, indicating that there is no specific p53 contribution to bystander killing. Bystander killing through peroxides emitted by apoptotic cells may propagate tissue injury in different pathological situations and be relevant in chemo-, gamma-ray, and gene therapy of cancer.

Ultrastructural organization of recombinant Marburg virus nucleoprotein: comparison with Marburg virus inclusions

HeLa cells expressing the recombinant Marburg virus (MBGV) nucleoprotein (NP) have been studied by immunoelectron microscopy. It was found that MBGV NPs assembled into large aggregates which were in close association with membranes of the rough endoplasmic reticulum. Further analysis of these aggregates revealed that NPs formed tubule-like structures which were arranged in a hexagonal pattern. A similar pattern of preformed nucleocapsids was detected in intracellular inclusions induced by MBGV infection. Our data indicated that MBGV NP is able to form nucleocapsid-like structures in the absence of the authentic viral genome and other nucleocapsid-associated proteins.

Respiratory Marburg virus infection in guinea pigs

Marburg virus (MV) reproduction in organs, hematological and pathological changes were studied by virological and clinical methods, light and electron microscopy in guinea pigs respiratory challenged by the virus. Liver and spleen were most affected by MV, as in parenteral infection. The sequential involvement of cells in virus replication was also the same as in parenteral infection, with monocytoid-macrophagal cells infected first, followed by hepatocytes, spongiocytes, endotheliocytes and fibroblasts. Hemopoietic cells showed evidence of severe damage in respiratory infected guinea pigs. A distinguishing feature of the respiratory infection was close contact of leucocytes with MV infected cells. It is suggested that the entrapment and accumulation of MV in the lungs of respiratory infected guinea pigs makes possible the enfoldment leucocyte attack which does not, however, result in destruction of the infected cells.

Ebola virus infection in guinea pigs: presumable role of granulomatous inflammation in pathogenesis

An approach combining virology with light and electron microscopy was used to study the organs of guinea pigs during nine serial passages of Ebola virus, strain Zaire. It was observed that the wild type of Ebola virus causes severe granulomatous inflammation in the liver and reproduces in the cells of the mononuclear phagocyte system (MPS). Based on morphological characterization, two types of virus-cell interactions were demonstrated. The obtained data evidenced for heterogeneity of the population of wild type of Ebola virus. The virus accumulated in the liver of the infected animals, and the lesions became more pronounced with passage. Degenerative changes appeared, and their severity was increased with passage in the other organs as well. The set of target cells diversified and, as a result, not only the MPS cells, but also hepatocytes, spongiocytes, endotheliocytes and fibroblasts became involved in the reproduction of Ebola virus. The possible role of granulomatous inflammation in the development of the adaptive mechanism of Ebola virus to guinea pigs is discussed.