The TcdE holin drives toxin secretion and virulence in Clostridioides difficile.

Clostridioides difficile is the leading cause of healthcare associated infections. The Pathogenicity Locus (PaLoc) toxins TcdA and TcdB promote host disease. These toxins lack canonical N-terminal signal sequences for translocation across the bacterial membrane, suggesting alternate mechanisms of release, which have included targeted secretion and passive release from cell lysis. While the holin TcdE has been implicated in TcdA and TcdB release, its role in vivo remains unknown. Here, we show profound reductions in toxin secretion in ΔtcdE mutants in the highly virulent strains UK1 (epidemic ribotype 027, Clade 3) and VPI10463 (ribotype 087, Clade 1). Notably, tcdE deletion in either strain rescued highly susceptible gnotobiotic mice from lethal infection by reducing acute extracellular toxin to undetectable levels, limiting mucosal damage, and enabling long-term survival, in spite of continued toxin gene expression in ΔtcdE mutants. Our findings confirm TcdE's critical functions in vivo for toxin secretion and C. difficile virulence.

Comparative analysis of the skim milk and milk fat globule membrane proteomes produced by Jersey cows grazing pastures with different plant species diversity.

The objective of this experiment was to identify and characterize the bovine milk proteome within the skim milk fraction and milk fat globule membrane (MFGM)-associated fraction from 16 organically certified lactating Jersey cows after a short term of grazing pastures with or without annual forage crops (AFC). Cows were offered a partial mixed ration (∼60% of dry matter intake) and approximately 40% of their total dry matter intake as herbage. Eight cows were offered a cool-season grass-legume herbage (GLH), which included orchardgrass (Dactylis glomerata), timothy (Phleum pratense), Kentucky bluegrass (Poa pratensis), and white clover (Trifolium repens). The other 8 cows were offered the same GLH strip-tilled with the AFC, including oat (Avena sativa), millet (Pennisetum glaucum), teff (Eragrostis tef), buckwheat (Fagopyrum esculentum), and chickling vetch (Lathyrus sativus). Milk samples were collected from each cow during a.m. and p.m. milkings on d 19 to 21 of grazing, and composite milk samples per cow were analyzed for (1) the high-abundance milk protein profile, (2) the skim milk low-abundance protein-enriched proteome, and (3) the MFGM proteome. Of the 443 proteins identified in the skim and MFGM proteomes, 433 were included in statistical analysis, including 68 proteins identified in the skim milk fraction and 365 in the MFGM-associated fraction. Analysis of the skim and MFGM proteomes encompassed unique gene ontology profiles and proportions of functional classifications. In response to diet, αS1-casein as well as 8 low-abundance proteins were present in higher concentration or abundance in milk from cows grazing the GLH strip-tilled with the AFC compared with milk from cows grazing GLH, suggesting that even short-term grazing of pastures including some AFC may affect the milk proteome.

[Intrauterine devices of a reduced size in nulliparous patients. Experience with Mini-Copper-7]. / I dispositivi intrauterini di taglia ridotta nella nullipara. Esperienza con il Mini Copper - 7.

PIP: The authors inserted a Mini Copper 7 device in 60 nulliparous women with a or= 7 cm intrauterine cavity; these users were then followed up for a total of 1220 cycles. 5 spontaneous expulsions, 2 intrauterine pregnancies, 8 removals and no cases of pelvic inflammatory disease were recorded. Although not very extensive, the experience reported offers contraceptive users an alternative in the demand for contraceptives, especially among nulliparous patients. (author's modified)^ieng

[Analysis of the various methods of voluntary interruption of pregnancy after the first ninety days of gestation]. / Analisi delle metodiche di intervento nella interruzione volontaria della gravidanza dopo il 90 giorno di gestazione.

PIP: Being that the last few years have seen a greater demand for pregnancy interruption after the 1st triemster, the authors describe the methods most ofter used, while specifying their validity and the possiblity of complications. A critical analysis is offered as a conclusion. (author's modified)^ieng