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.

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.

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%.