Higher risk of urinary tract infections in renal transplant recipients receiving pentamidine versus trimethoprim-sulfamethoxazole (TMP-SMX) for Pneumocystis pneumonia prophylaxis.

Urinary tract infection (UTI) is one of the most common infectious complications among renal transplant patients. Trimethoprim-sulfamethoxazole (TMP-SMX) is routinely used as first-line prophylaxis against Pneumocystis pneumonia (PCP) and other opportunistic infections including UTI. Aerosolized pentamidine is an alternate agent used for PCP prophylaxis; however, it does not provide coverage against uropathogens. This is a retrospective study of 81 renal transplant recipients who received TMP-SMX or aerosolized pentamidine for PCP prophylaxis at our center over 1 year. Survival analysis demonstrated increased cumulative incidence of UTI among patients receiving pentamidine for PCP prophylaxis compared to those receiving TMP-SMX (log-rank test P < .001). Univariate and multivariate Cox proportional hazard regression model showed pentamidine prophylaxis (HR 3.740; 95% CI 1.745-8.016; P = .001) and female sex (HR 4.025; 95% CI 1.770-9.154; P = .001) to independently increase UTI risk. Age, induction agent, graft type, diabetes, and delayed graft function (DGF) were not associated with increased risk. This study concludes that the use of pentamidine for PCP prophylaxis compared to TMP-SMX is associated with increased risk of UTI. Secondary UTI prophylaxis may be considered for patients who are unable to tolerate TMP-SMX and who have other risk factors for UTI; however, the efficacy of this has not been studied.

Functional Complementation Analysis (FCA): A Laboratory Exercise Designed and Implemented to Supplement the Teaching of Biochemical Pathways.

Functional complementation assay (FCA) is an in vivo assay that is widely used to elucidate the function/role of genes/enzymes. This technique is very common in biochemistry, genetics and many other disciplines. A comprehensive overview of the technique to supplement the teaching of biochemical pathways pertaining to amino acids, peptidoglycan and the bacterial stringent response is reported in this manuscript. Two cDNAs from the model plant organism Arabidopsis thaliana that are involved in the metabolism of lysine (L,L-diaminopimelate aminotransferase (dapL) and tyrosine aminotransferase (tyrB) involved in the metabolism of tyrosine and phenylalanine are highlighted. In addition, the bacterial peptidoglycan anabolic pathway is highlighted through the analysis of the UDP-N-acetylmuramoyl-L-alanyl-D-glutamate-meso-2,6-diaminopimelate ligase (murE) gene from the bacterium Verrucomicrobium spinosum involved in the cross-linking of peptidoglycan. The bacterial stringent response is also reported through the analysis of the rsh (relA/spoT homolog) bifunctional gene responsible for a hyper-mucoid phenotype in the bacterium Novosphingobium sp. Four examples of FCA are presented. The video will focus on three of them, namely lysine, peptidoglycan and the stringent response.