COMBINATORIAL EFFECT OF D-AMINOACIDS AND TETRACYCLINE AGAINST PSEUDOMONAS AERUGINOSA BIOFILM

Objective: The present study attempted to evaluate the anti-biofilm activity of D-amino acids (D-AAs) on Pseudomonas aeruginosa and determine if the combination of D-AAs with tetracycline enhances the anti-biofilm activity in vitro and ex vivo.Methods: Different D-AAs were tested for antibiofilm activity against wild type P. aeruginosa PAO1 and two multidrug resistant P. aeruginosa clinical strains in the presence of sub inhibitory concentrations of tetracycline using crystal violet microtitre plate assay. Results were further validated using in vitro wound dressing and ex vivo porcine skin models followed by cytotoxicity and hemocompatibility studies.Results: D-tryptophan (5 mmol) showed 61 % reduction in biofilm formation of P. aeruginosa. Interestingly combinatorial effect of 5 mmol D-tryptophan and 0.5 minimum inhibitory concentration (MIC) (7.5µg/ml) tetracycline showed 90% reduction in biofilm formation. 5 mmol D-methionine shows 28 % reduction and combination with tetracycline shows 41% reduction in biofilm formation of P. aeruginosa. D-leucine and D-tyrosine alone or in combination with tetracycline did not show significant anti-biofilm activity. D tryptophan-tetracycline combination could reduce 80 % and 77 % reduction in biofilm formation in two multi drug resistant P. aeruginosa clinical strains. D-tryptophan-tetracycline-combination could also reduce 76% and 66% reduction in biofilm formation in wound dressing model and porcine skin explant respectively. The cytotoxicity and hemocompatibility studies did not show significant toxicity when this combination was used.Conclusion: The results established the potential therapeutic application of D-tryptophan alone or in combination with tetracycline for treating biofilm associated clinical problems caused by P. aeruginosa

The genetic discrimination observatory : confronting novel issues in genetic discrimination

Genetic discrimination (GD) is the differential or unfair profiling of an individual on the basis of genetic data. This article summarizes the actions of the Genetic Discrimination Observatory (GDO) in addressing GD and recent developments in GD since late 2020. It shows how GD can take many forms in today’s rapidly evolving society.http://www.journals.elsevier.com/trends-in-geneticshj2022Immunolog

Efficacy & safety of Carica papaya leaf extract (CPLE) in severe thrombocytopenia (≤30,000/μl) in adult dengue - Results of a pilot study.

Severe thrombocytopenia in dengue often prompts platelet transfusion primarily to reduce bleeding risk. In India, about 11-43% of dengue patients report receiving platelet transfusions which is considered scarce and expensive especially in resource limited settings. Herein, we evaluated the efficacy and safety of Carica papaya leaf extract (CPLE) in the management of severe thrombocytopenia (≤30,000/μL) in dengue infection. 51 laboratory confirmed adult dengue patients with platelet counts ≤30,000/μL were randomly assigned to either treatment (n = 26) or placebo (n = 24) group. By day 3, CPLE treated patients reported significantly (p = 0.007) increased platelet counts (482%± 284) compared to placebo (331%±370) group. In the treatment group, fewer patients received platelet transfusions (1/26 v/s 2/24) and their median time for platelets to recover to ≥ 50,000/μL was 2 days (IQR 2-3) compared to 3 days (IQR 2-4) in placebo. Overall, CPLE was safe and well tolerated with no significant decrease in mean hospitalization days. Plasma cytokine profiling revealed that by day 3, mean percent increase in TNFα and IFNγ levels in treatment group was less compared to that observed in placebos; (TNFα: 58.6% v/s 127.5%; p = 0.25 and IFNγ: 1.93% v/s 62.6% for; p = 0.12). While a mean percent increase in IL-6 levels occurred in placebos (15.92%±29.93%) by day 3, a decrease was noted in CPLE group (12.95%±21.75%; p = 0.0232). Inversely, CPLE treated patients reported a mean percent increase compared to placebo by day 3 (143% ±115.7% v/s 12.03%± 48.4%; p = 0.006). Further, by day 3, a faster clearance kinetics of viral NS1 antigenemia occurred-mean NS1 titers in treatment group decreased to 97.3% compared to 88% in placebos (p = 0.023). This study demonstrates safety and efficacy of CPLE in increasing platelet counts in severe thrombocytopenia in dengue infections. A possible immunomodulatory and antiviral activity may be attributed to CPLE treatment. These findings merit validation in larger prospective studies. Trial registration Name of the registry: Clinical Trials Registry-India (CTRI) Registration No.: CTRI-REF/2017/02/013314

Establishing the International Genetic Discrimination Observatory

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