Antimicrobial effect of Moringa oleifera seed powder against Vibrio cholerae isolated from the rearing water of shrimp (Penaeus vannamei) postlarvae.

Shrimp farming has experienced rising costs as a result of disease outbreaks associated with Vibrio spp. Suitable strategies for disease prevention and control are therefore urgently needed. This study aimed to evaluate the antimicrobial effect of Moringa oleifera seed powder against Vibrio cholerae in the rearing water of Pacific white shrimp (Penaeus vannamei) postlarvae. In vitro assays included the determination of minimum inhibitory concentration (MIC) of M. oleifera seed powder against V. cholerae, whereas in vivo assays included the effect of M. oleifera seed powder on bacterial load and water quality parameters in the rearing tanks, as well as its effect on shrimp postlarvae survival. M. oleifera seed powder inhibited the growth of V. cholerae with MIC values of 62·5 µg ml-1 . Moreover, seawater pH of treated tanks (8·66) was significantly lower (P < 0·01) than pH of the control tanks (9·02), whereas the visibility of treated tanks (37·08 cm) was significantly higher (P < 0·01) as compared to control tanks (35·37 cm). Likewise, V. cholerae load was significantly reduced (P < 0·01) from 4·7 × 104 to 3·1 × 103  CFU per ml in tanks treated with M. oleifera seed powder. Altogether, this study demonstrates the antimicrobial activity of M. oleifera against V. cholerae in shrimp culture.

Outcome of treatment of MDR-TB or drug-resistant patients treated with bedaquiline and delamanid: Results from a large global cohort.

The World Health Organization (WHO) recommends countries introduce new anti-TB drugs in the treatment of multidrug-resistant tuberculosis. The aim of the study is to prospectively evaluate the effectiveness of bedaquiline (and/or delamanid)- containing regimens in a large cohort of consecutive TB patients treated globally. This observational, prospective study is based on data collected and provided by Global Tuberculosis Network (GTN) centres and analysed twice a year. All consecutive patients (including children/adolescents) treated with bedaquiline and/or delamanid were enrolled, and managed according to WHO and national guidelines. Overall, 52 centres from 29 countries/regions in all continents reported 883 patients as of January 31st 2021, 24/29 countries/regions providing data on 100% of their consecutive patients (10-80% in the remaining 5 countries). The drug-resistance pattern of the patients was severe (>30% with extensively drug-resistant -TB; median number of resistant drugs 5 (3-7) in the overall cohort and 6 (4-8) among patients with a final outcome). For the patients with a final outcome (477/883, 54.0%) the median (IQR) number of months of anti-TB treatment was 18 (13-23) (in days 553 (385-678)). The proportion of patients achieving sputum smear and culture conversion ranged from 93.4% and 92.8% respectively (whole cohort) to 89.3% and 88.8% respectively (patients with a final outcome), a median (IQR) time to sputum smear and culture conversion of 58 (30-90) days for the whole cohort and 60 (30-100) for patients with a final outcome and, respectively, of 55 (30-90) and 60 (30-90) days for culture conversion. Of 383 patients treated with bedaquiline but not delamanid, 284 (74.2%) achieved treatment success, while 25 (6.5%) died, 11 (2.9%) failed and 63 (16.5%) were lost to follow-up.

SARS-CoV2/COVID-19 Infection in Transplant Recipients and in Patients on the Organ Transplant Waiting List in Colombia.

To assess our determination to continue transplant activity in Colombia during the coronavirus disease 2019 (COVID-19) pandemic, this study seeks to describe the risk of infection and mortality of transplanted patients vs those on the waiting list. Therefore, a descriptive study of severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2)/COVID-19 infection in transplant recipients and patients on the waiting list was conducted. The data sources were the information systems of the Instituto Nacional de Salud of Colombia: National Donation and Transplant Information System, the National Public Health Surveillance System, and the National COVID-19 Data Repository. Characteristics of the patients who tested positive were analyzed, and the mortality rate was determined. An Real Time-PCR test for SARS-CoV-2/COVID-19 was performed in 7% of the transplant recipients included in this study, and 14.8% of those recipients tested positive. Among patients on the waiting list, 15.2% were tested, and 16.7% showed positive results. Overall, 1% (84/8108) of the transplant recipients and 2.5% (74/2926) of patients on the waiting list were infected with SARS-CoV-2/COVID-19. There were no differences in mortality between these groups (P = .8748). In conclusion, with the data obtained so far, the hospital availability, and the adoption of safety protocols in the institutions, our findings can support the continuity of the transplant activities in this country.

[Subacute meningococcaemia during adalimumab therapy]. / Méningococcémie subaiguë sous adalimumab.

INTRODUCTION: Subacute or chronic meningococcaemia is an invasive infection by Neisseria meningitidis characterized by fever lasting between a few days (subacute) and a week or more (chronic), cutaneous rash and arthralgia, without meningitis. PATIENTS AND METHODS: A 59-year-old woman was admitted for a fever with cutaneous rash. She had a history of Crohn's disease diagnosed in 2016 and treated with adalimumab for 14 months at a dosage of 40mg/week. For 3 days, she presented fever with a temperature of up to 40°C associated with a non-itchy erythematous-papular eruption on all four limbs, especially the lower limbs. The lesions were mildly painful on palpation. The rest of the clinical examination was unremarkable. The patient did not have arthralgia or neurological symptoms, and in particular, she exhibited no meningeal syndrome. Blood cultures as well as PCR on a skin biopsy specimen confirmed the diagnosis of meningococcaemia. The patient was treated with ceftriaxone 2g/day for 4 days then amoxicillin 12g/day for 4 days. A favourable outcome was quickly achieved, and the condition subsided without sequelae. DISCUSSION: We report the first case of subacute meningococcaemia in a patient treated with anti-TNF alpha therapy. This case concerns the role of biotherapies, and more particularly anti-TNF alpha therapy, in the occurrence of particular infections but also in changes in their clinical presentation and clinical course, as in the present case without arthralgia.

T cell suppression in vitro during Toxoplasma gondii infection is the result of IL-2 competition between Tregs and T cells leading to death of proliferating T cells.

A reduced proliferation to T cell mitogens is observed in vitro in murine cells isolated during the acute phase of Toxoplasma gondii infection. Foxp3(+) regulatory T cells (Tregs) mediate this suppression, which is interleukin (IL)-2 dependent. In this work, we analysed the mechanism of this Treg-mediated suppression. We found that removal of antigen-presenting cells (APC) from spleen cells from infected mice did not modify suppression but further elimination of Tregs led to a restored proliferation, demonstrating that Tregs mediate suppression in the absence of APC. Production of IL-2 by T cells from infected animals was abolished but partially restored when Tregs were removed. However, IL-2 levels and T cell proliferation were restored when Tregs and T cells were separated by transwells, indicating that Tregs require close proximity with T cells to induce suppression. Tregs from infected mice were able to reduce proliferation of CTLL-2 cells in the classical IL-2 bioassay, strongly suggesting that Tregs compete with T cells for IL-2. We found that T cells from infected mice died after a few rounds of division in vitro, but addition of recombinant IL-2 or removal of Tregs abolished this effect. Our results showed that suppression of T cell proliferation during acute Toxoplasma gondii infection is the result of death of proliferating T cells by Treg-mediated IL-2 competition. Thus, immunosuppression is due to death of proliferating T cells as a consequence of low IL-2 availability.

The sensitivity of tropical leaf litter decomposition to temperature: results from a large-scale leaf translocation experiment along an elevation gradient in Peruvian forests.

• We present the results from a litter translocation experiment along a 2800-m elevation gradient in Peruvian tropical forests. The understanding of the environmental factors controlling litter decomposition is important in the description of the carbon and nutrient cycles of tropical ecosystems, and in predicting their response to long-term increases in temperature. • Samples of litter from 15 species were transplanted across all five sites in the study, and decomposition was tracked over 448 d. • Species' type had a large influence on the decomposition rate (k), most probably through its influence on leaf quality and morphology. When samples were pooled across species and elevations, soil temperature explained 95% of the variation in the decomposition rate, but no direct relationship was observed with either soil moisture or rainfall. The sensitivity of the decay rate to temperature (κ(T)) varied seven-fold across species, between 0.024 and 0.169 °C⁻¹, with a mean value of 0.118 ± 0.009 °C⁻¹ (SE). This is equivalent to a temperature sensitivity parameter (Q10) for litter decay of 3.06 ± 0.28, higher than that frequently assumed for heterotrophic processes. • Our results suggest that the warming of approx. 0.9 °C experienced in the region in recent decades may have increased decomposition and nutrient mineralization rates by c. 10%.

Ultrastructural study of unencapsulated vertebrate mechanoreceptor terminals facilitated by double staining and resectioning of thick plastic sections.

A set of techniques for localization of unencapsulated sensory receptor terminals in plastic-embedded tissue is described. The tissue is pinned flat in fixative and flat-embedded in a small amount of medium-soft Epon. Pieces of the specimen are remounted so that tangential thick sections (2-3 micron) can be cut. These sections are stained with a mixture of 15 ml of 0.5% toluidine blue, 1% sodium borate; 10 ml of 2% p-phenylenediamine, and 5 ml of acetone. Stained sections are examined with a light microscope and brown-stained sensory receptor regions are located. Sections to be examined in the electron microscope are remounted by inverting a capsule of medium-hard Epon over them, and polymerized blocks are removed from the slide after heating it. Thin sections cut from remounted thick sections are stained with uranyl acetate and lead citrate. This procedure has been used successfully to locate aortic baroreceptors and very small apparent nerve endings in the atrium of the rat as well as stretch receptors in dog trachealis muscle. All of these receptor endings stain brown and are surrounded by light blue collagen and darker blue Schwann cells.