Management of Phytophthora parasitica causing gummosis in citrus using biogenic copper oxide nanoparticles

AIM

The main aim of the present study is to develop nanotechnology-based solutions for the management of a fungus, Phytophthora parasitica causing gummosis in citrus.

METHODS AND RESULTS

Biogenic copper nanoparticles (CuONPs) were synthesized using two different biocontrol agents, Pseudomonas fluorescens and Trichoderma viride and characterized using different analytical techniques. Further, in vitro (at the concentrations of 10 mg/L, 15 mg/L, 30 mg/L, 50 mg/L, 70 mg/L, 100 mg/L and 150 mg/L) and in vivo (at the concentration of 100 mg/L) activities of these nanoparticles were evaluated for their antifungal efficacy against P. parasitica. The results obtained confirmed the synthesis of irregular shaped CuONPs having a size in the range of 40-100 nm in case of P. fluorescens, whereas, spherical CuONPs in the size range of 20-80 were recorded in case of T. viride. As far as the in vitro antifungal efficacies of both these CuONPs is concerned, the maximum percent growth inhibition was observed in case of CuONPs synthesized from T. viride compared to CuONPs from P. fluorescens. However, in case of in vivo antifungal efficacies, CuONPs synthesized from T. viride showed the activity significantly higher than the conventionally used Bordeaux mixture.

CONCLUSIONS

It can be concluded that biosynthesized CuONPs can be effectively used as a potential fungicide against P. parasitica.

SIGNIFICANCE AND IMPACT OF THE STUDY

The application of nanoparticles having antifungal activities can be used as alternative fungicides to the conventional chemical fungicides. It has the potential to revolutionize the existing management strategies available for plant pathogenic fungi.

Effect of Donor Hepatic Steatosis on Ischemia Reperfusion Injury in Liver Transplant Recipient

INTRODUCTION

Ischemia reperfusion injury (IRI) is an important complication of liver transplant (LT). The donor risk index, which does not incorporate steatosis, includes several variables known to impact on allograft survival. The purpose of this study was to report on donor liver allograft steatosis and its association with severity of IRI.

AIM

The aim of this study was to determine the effect of type and grade of donor liver steatosis on the occurrence and severity of IRI in LT recipients.

METHODS

This was an observational study conducted at a single center over a period of 37 months from July 2013 to August 2016. Liver biopsy was performed twice, initially at the time of procurement before graft perfusion for steatosis assessment. Steatosis was classified as microsteatosis (MiS) or macrosteatosis (MaS) with mild, moderate, or severe grade. Second biopsy for IRI assessment was taken before skin closure in death donor LT (DDLT) and at the time of transaminitis in postoperative period (<72 hrs) in living donor LT (LDLT). IRI was graded as per neutrophil infiltrate, apoptosis, and hepatocyte cell dropout. Prevalence of IRI and association steatosis was studied along with other factors.

RESULTS

Among 53 subjects, 35 were DDLTs and 18 were LDLTs. All live donor grafts were restricted to <15% MaS and the deceased liver grafts had different type and degree of steatosis. In DDLTs, the association between occurrence of IRI and MaS was not statistically significant (P = 0.201). In DDLTs, the mild steatosis was not significantly associated with IRI. Death donor and ischemic time were significantly associated with IRI. Child's stage and MELD scores, gender, and age were not associated with risk of IRI. Severity of IRI is significantly associated with 3-month mortality (P = 0.001).

CONCLUSION

In patients with mild steatosis, IRI does not correlate with steatosis. However, more patients with moderate and severe steatosis are needed to define the relationship of the two in this group of patients.

Threshold somatic cell count for delineation of subclinical mastitis cases

Aim:

Somatic cell count (SCC) is the most widely used single reliable indicator of udder health. The present study was carried out with an objective to find the exact threshold of SCC.

Materials and Methods:

Milk samples collected from a total of 214 Holstein Friesian crossbred dairy animals were subjected to bacterial DNA extraction and SCC estimation by digital PortaCheck. California Mastitis Test and polymerase chain reaction based on amplification of organism using reported primers were performed to diagnose subclinical mastitis. Receiver’s operating characteristic (ROC) curve analysis and discriminate function analyses were performed using SPSS 18 software.

Results:

ROC curve analysis represented that the area under the curve was 0.930 with the standard error of 0.02. Results indicated that 93% of the case could be correctly predicted as mastitis infected using SCC as a marker (p<0.001). At cut score level of 282 000 cells/ml, 285,000 cells/ml and 288,000 cells/ml, sensitivity remained 92.6% and specificity augmented as 86.3%, 87.2%, and 88%, respectively. At SCC value of 310,000 cells/ml of milk, sensitivity and specificity were optimal, namely, 92.6% and 91.5%, respectively. The function fitted demonstrated 89.2% accuracy with p<0.001. The functions at group centroids were −0.982 and 1.209, respectively, for normal and mastitis-infected animals and log_SCC value was the most important factor contributing 38.30% of the total distance measured.

Conclusion:

Our study supports that the threshold value to delineate subclinical mastitis case from the normal is 310,000 somatic cells/ml of milk and a model so fitted using the variable SCC can be successfully used in field for the diagnosis of subclinical cases of mastitis which otherwise would be difficult to differentiate based on clinical signs.