Economic and disease burden of RSV-associated hospitalizations in young children in France, from 2010 through 2018.

BACKGROUND: Respiratory syncytial virus (RSV) is the main cause of infant and child hospitalizations. The study objective is to estimate the RSV-associated hospitalizations and economic burden in young children in France to inform future preventive strategies. METHODS: We conducted a retrospective analysis of RSV-associated hospitalizations data from the French Hospital database (PMSI-MCO) which covers the entire French population. All children aged < 5 years hospitalized with RSV ICD-10 codes (J210, J219, J45, J121, J205, R062) from 2010 to 2018, were included. Descriptive analyses were conducted by RSV seasons (Oct to March), by respiratory years (July to June) and per age groups. RESULTS: On average 45,225 RSV-associated hospitalizations (range: 43,715 - 54,616) per season was reported in France, 69% among children < 1 year old. This represents 28% of all-cause hospitalizations that occurred among children < 1 year old, and less than 10% of all-cause hospitalizations in older children. Number of RSV-associated hospitalizations were similar for infants born during (Oct-March) or outside (April-September) their first RSV season. The highest risk being reported for infants born from September through November. The associated hospitalization cost increased between 2010 - 11 and 2017-18, from €93.2 million to €124.1 million, respectively, and infants < 1 year old represented 80% of the economic burden. CONCLUSION: RSV is an important cause of child hospitalization in France. The burden on healthcare system is mainly driven by < 1 year olds, and preventive strategies should be implemented before the first RSV season.

Telemedicine for ENT: Effect on quality of care during Covid-19 pandemic.

AIMS: To assess the benefit of telemedicine consultation during the Covid-19 pandemic. MATERIAL AND METHODS: A prospective study of patient satisfaction with telemedicine consultation was carried out in the ENT department of a university hospital center where telemedicine consultations were set up to replace scheduled out-patient consultations. Patients were divided into two groups according to overall satisfaction, in order to identify predictive factors. The significance threshold was set at P<0.005. The main endpoint was patient satisfaction after an ENT telemedicine consultation during global lockdown. The secondary endpoint comprised predictive factors for overall satisfaction. RESULTS: One hundred of the 125 patients with telemedicine consultation over a 7-day inclusion period completed the questionnaire. Overall satisfaction was 87%. There were no clinically relevant predictive factors significantly associated with satisfaction. Sound and video quality was satisfactory for 76% and 61% of patients respectively, without significant impact on overall satisfaction (respectively: OR=3.40, P-value=0.049; and OR=3.79, P-value=0.049). Lack of physical examination did not significantly correlate with reduced overall satisfaction (OR=0.30, P-value=0.027). CONCLUSION: Telemedicine consultation did not allow complete medical care but, in a difficult time like the global pandemic, was well accepted by patients. It is a simple way to maintain continuity of care while reducing contamination risk by avoiding direct contact between patients and healthcare professionals.

Gene disruption through homologous recombination in Spiroplasma citri: an scm1-disrupted motility mutant is pathogenic.

To determine whether homologous recombination could be used to inactivate selected genes in Spiroplasma citri, plasmid constructs were designed to disrupt the motility gene scm1. An internal scm1 gene fragment was inserted into plasmid pKT1, which replicates in Escherichia coli but not in S. citri, and into the S. citri oriC plasmid pBOT1, which replicates in spiroplasma cells as well as in E. coli. Electrotransformation of S. citri with the nonreplicative, recombinant plasmid pKTM1 yielded no transformants. In contrast, spiroplasmal transformants were obtained with the replicative, pBOT1-derived plasmid pCJ32. During passaging of the transformants, the plasmid was found to integrate into the chromosome by homologous recombination either at the oriC region or at the scm1 gene. In the latter case, plasmid integration by a single crossover between the scm1 gene fragment carried by the plasmid and the full-length scm1 gene carried by the chromosome led to a nonmotile phenotype. Transmission of the scm1-disrupted mutant to periwinkle (Catharanthus roseus) plants through injection into the leafhopper vector (Circulifer haematoceps) showed that the motility mutant multiplied in the insects and was efficiently transmitted to plants, in which it induced symptoms similarly to the wild-type S. citri strain. These results suggest that the spiroplasmal motility may not be essential for pathogenicity and that, more broadly, the S. citri oriC plasmids can be considered promising tools for specific gene disruption by promoting homologous recombination in S. citri, a mollicute which probably lacks a functional RecA protein.

Isolation, characterization, and complementation of a motility mutant of Spiroplasma citri.

The helical mollicute Spiroplasma citri, when growing on low-agar medium, forms fuzzy colonies with occasional surrounding satellite colonies due to the ability of the spiroplasmal cells to move through the agar matrix. In liquid medium, these helical organisms flex, twist, and rotate rapidly. By using Tn4001 insertion mutagenesis, a motility mutant was isolated on the basis of its nondiffuse, sharp-edged colonies. Dark-field microscopy observations revealed that the organism flexed at a low frequency and had lost the ability to rotate about the helix axis. In this mutant, the transposon was shown to be inserted into an open reading frame encoding a putative polypeptide of 409 amino acids for which no significant homology with known proteins was found. The corresponding gene, named scm1, was recovered from the wild-type strain and introduced into the motility mutant by using the S. citri oriC plasmid pBOT1 as the vector. The appearance of fuzzy colonies and the observation that spiroplasma cells displayed rotatory and flexional movements showed the motile phenotype to be restored in the spiroplasmal transformants. The functional complementation of the motility mutant proves the scm1 gene product to be involved in the motility mechanism of S. citri.

Suppression of Ripening-Associated Gene Expression in Tomato Fruits Subjected to a High CO2 Concentration.

High concentrations of CO2 block or delay the ripening of fruits. In this study we investigated the effects of high CO2 on ripening and on the expression of stress- and ripening-inducible genes in cherry tomato (Lycopersicon esculentum Mill.) fruit. Mature-green tomato fruits were submitted to a high CO2 concentration (20%) for 3 d and then transferred to air. These conditions effectively inhibited ripening-associated color changes and ethylene production, and reduced the protein content. No clear-cut effect was observed on the expression of two proteolysis-related genes, encoding polyubiquitin and ubiquitin-conjugating enzyme E2, respectively. Exposure of fruit to high CO2 also resulted in the strong induction of two genes encoding stress-related proteins: a ripening-regulated heat-shock protein and glutamate decarboxylase. Induction of these two genes indicated that high CO2 had a stress effect, most likely through cytosolic acidification. In addition, high CO2 blocked the accumulation of mRNAs for genes involved in the main ripening-related changes: ethylene synthesis (1-aminocyclopropane-1-carboxylic acid synthase and 1-aminocyclopropane-1-carboxylic acid oxidase), color (phytoene synthase), firmness (polygalacturonase), and sugar accumulation (acid invertase). The expression of ripening-specific genes was affected by CO2 regardless of whether their induction was ethylene- or development-dependent. It is proposed that the inhibition of tomato fruit ripening by high CO2 is due, in part, to the suppression of the expression of ripening-associated genes, which is probably related to the stress effect exerted by high CO2.

Integrative and free Spiroplasma citri oriC plasmids: expression of the Spiroplasma phoeniceum spiralin in Spiroplasma citri.

The replication region (oriC) of the Spiroplasma citri chromosome has been recently sequenced, and a 2-kbp DNA fragment was characterized as an autonomously replicating sequence (F. Ye, J. Renaudin, J. M. Bové, and F. Laigret, Curr. Microbiol. 29:23-29, 1994). In the present studies, we have combined this DNA fragment, containing the dnaA gene and the flanking dnaA boxes, with a ColE1-derived Escherichia coli replicon and the Tet M determinant, which confers resistance to tetracycline. The recombinant plasmid, named pBOT1, was introduced into S. citri cells, in which it replicated. Plasmid pBOT1 was shuttled from E. coli to S. citri and back to E. coli. In S. citri, replication of pBOT1 did not require the presence of a functional dnaA gene on the plasmid. However, the dnaA box region downstream of the dnaA gene was essential. Upon passaging of the S. citri transformants, the plasmid integrated into the spiroplasmal host chromosome by recombination at the replication origin. The integration process led to duplication of the oriC sequences. In contrast to the integrative pBOT1, plasmid pOT1, which does not contain the E. coli replicon, was stably maintained as a free extrachromosomal element. Plasmid pOT1 was used as a vector to introduce into S. citri the G fragment of the cytadhesin P1 gene of Mycoplasma pneumoniae and the spiralin gene of Spiroplasma phoeniceum. The recombinant plasmids, pOTPG with the G fragment and pOTPS with the spiralin gene, were stably maintained in spiroplasmal transformants. Expression of the heterologous S. phoeniceum spiralin in S. citri was demonstrated by Western immunoblotting.

Cadmium-induced ultrastructural changes in Euglena cells.

The ultrastructure of Euglena gracilis grown in the presence of Cd showed only numerous myelin-like structures in mitochondria, chloroplasts altered in shape, and thylakoid arrangement and increase of osmiophilic plastoglobuli. These alterations indicate that respiratory processes are the initial target of Cd toxicity.