Wastewater-based epidemiology for tracking bacterial diversity and antibiotic resistance in COVID-19 isolation hospitals in Qatar.

BACKGROUND: Hospitals are hotspots for antimicrobial resistance genes (ARGs), and play a significant role in their emergence and spread. Large numbers of ARGs will be ejected from hospitals via wastewater systems. Wastewater-based epidemiology has been consolidated as a tool to provide real-time information, and represents a promising approach to understanding the prevalence of bacteria and ARGs at community level. AIMS: To determine bacterial diversity and identify ARG profiles in hospital wastewater pathogens obtained from coronavirus disease 2019 (COVID-19) isolation hospitals compared with non-COVID-19 facilities during the pandemic. METHODS: Wastewater samples were obtained from four hospitals: three assigned to patients with COVID-19 patients and one assigned to non-COVID-19 patients. A microbial DNA quantitative polymerase chain reaction was used to determine bacterial diversity and ARGs. FINDINGS: The assay recorded 27 different bacterial species in the samples, belonging to the following phyla: Firmicutes (44.4%), Proteobacteria (33.3%), Actinobacteria (11%), Bacteroidetes (7.4%) and Verrucomicrobiota (3.7%). In addition, 61 ARGs were detected in total. The highest number of ARGs was observed for the Hazem Mebaireek General Hospital (HMGH) COVID-19 patient site (88.5%), and the lowest number of ARGs was found for the HMGH non-patient site (24.1%). CONCLUSION: The emergence of contaminants in sewage water, such as ARGs and high pathogen levels, poses a potential risk to public health and the aquatic ecosystem.

Outcome of desensitization in human leukocyte antigen- and ABO-incompatible living donor kidney transplantation: a single-center experience in more than 100 patients.

BACKGROUND: Antibody-mediated rejection (AMR) and inferior graft outcome remain the 2 most important obstacles to successful kidney transplantation in human leukocyte antigen (HLA)- and ABO-incompatible recipients. We report a single-center experience in the outcome of desensitized living donor HLA- and ABO-incompatible kidney transplantation. METHODS: Since 2007 we included 2 groups in our desensitization program. HLA-incompatible living donor kidney transplant candidates displaying donor-specific antibodies (DSA) with or without a positive T-cell and/or B-cell flow crossmatch (FCXM). Second, those displaying DSA with positive T-cell immunoglobulin (Ig)G AHG CDC CXM with a titer of ≤1:8, as well as all ABO-incompatible living donor kidney transplant candidates with an IgM isoagglutinin titer ≤ 256. They were risk stratified for AMR and underwent individualized desensitization protocol: ABO-incompatible and HLA-incompatible candidates with either positive AHG CDC CXM or positive T and/or B IgG flow CXM with repeat HLA mismatch from a previous transplantation were deemed to be high risk and received a single dose of Rituximab, therapeutic plasma exchange and high-dose intravenous immunoglobulin (IVIG) (2 g/kg). HLA-incompatible candidates with negative CDC but positive T and/or B IgG FCXM were deemed intermediate risk, receiving rituximab and high-dose IVIG. Those with positive DSA but negative flow and CDC CXM were deemed low risk, receiving low-dose IVIG (1 g/kg). All patients received induction with thymoglobulin and were maintained on a tacrolimus-based immunosuppressive regimen. RESULTS: Among 124 incompatible recipients, 85 received HLA-incompatible and 39 ABO-incompatible living donor kidney transplantations after desensitization. Risk stratification for HLA-incompatible transplants revealed 61 high-risk, 42 intermediate-risk, and 21 low-risk cases. Ninety-nine (80%) were primary transplants. At a median follow-up of 23 (range 1-53) months, patient survival was 98% and death censored graft survival 96%. Mean serum creatinine was 84 µmol/L (range 41-169). Acute cellular rejection was observed in 15 (12%) and AMR in 5 (4%) patients. All rejection episodes responded to treatment except 1 AMR in an ABO-incompatible transplant that led to graft failure. CONCLUSION: Our risk stratification for desensitization strategy achieved a low incidence of AMR among HLA- and ABO-incompatible kidney transplant recipients. Their 2-year data appear to be comparable to HLA- and ABO-compatible transplantations.

Use of yttrium-90 microsphere radioembolization of hepatocellular carcinoma as downstaging and bridge before liver transplantation: a case report.

BACKGROUND AND OBJECTIVE: Yttrium-90 microspheres radioembolization (Y90-RE) has been recently introduced as promising modality of treatment in patients with hepatocellular carcinoma (HCC) who are not otherwise candidates for local ablation, surgical resection, or liver transplantation (OLT). However, its use in downstaging HCC or as a bridge for OLT is still unclear. Herein, we have presented a case where Y90-RE was used to both downstage and to serve as a bridge for OLT. CASE REPORT: We report a 54-year-old lady who was known to have hepatitis B virus cirrhosis in addition to two focal hepatic lesions in segments 5 and 8, measuring 1.5 and 7.5 cm, respectfully. Extrahepatic spread was thoroughly ruled out. This tumor was clearly beyond both the Milans and University of California San Francisco criteria for OLT in HCC patients; therefore, we offered the patient Y90-RE in an attempt to downstage the tumor and as a bridge for OLT. Y90-RE was performed targeting the large lesion; the patient underwent cadaveric OLT 2 months thereafter. Gross examination of the explant showed necrotic tumor with obvious signs of irradiation-induced damage. Microscopic examination of the explant showed Y90 microspheres trapped in the large tumor with near-complete tumor necrosis. This patient completed 1-year post-OLT follow-up with no signs of tumor recurrence. CONCLUSIONS: The use Y90-RE in HCC may be useful for downstaging or as a bridge to liver transplantation.