Update on Dihydropteroate Synthase (DHPS) Mutations in Pneumocystis jirovecii

A Pneumocystis jirovecii is one of the most important microorganisms that cause pneumonia in immunosupressed individuals. The guideline for treatment and prophylaxis of Pneumocystis pneumonia (PcP) is the use of a combination of sulfa drug-containing trimethroprim and sulfamethoxazole. In the absence of a reliable method to culture Pneumocystis, molecular techniques have been developed to detect mutations in the dihydropteroate synthase gene, the target of sulfa drugs, where mutations are related to sulfa resistance in other microorganisms. The presence of dihydropteroate synthase (DHPS) mutations has been described at codon 55 and 57 and found almost around the world. In the current work, we analyzed the most common methods to identify these mutations, their geographical distribution around the world, and their clinical implications. In addition, we describe new emerging DHPS mutations. Other aspects, such as the possibility of transmitting Pneumocystis mutated organisms between susceptible patients is also described, as well as a brief summary of approaches to study these mutations in a heterologous expression system.

Synthesis and Antibacterial Property of An Encapsulated Sulfonamide Nanoparticle in a Multidisciplinary Approach

Multigram quantity of a novel Sulfa Drug complex -poly(amido)amine-sulfonamide or PAMAM-Sulfa- was synthesized, from commercially available materials. It was characterized with spectroscopic methods such as nuclear magnetic resonance (NMR). The Kirby-Bauer test was used to test it against gram positive and/or gram negative bacteria using different concentrations of an ethanol solution of the PAMAM-Sulfa complex. The goal of this experiment was to synthesize and study the effect of water soluble encapsulated sulfonamides on common bacteria by undergraduate students engaging in research involving more than one STEM discipline. Students synthesized a dendrimer-sulfonamide complex before evaluating its antibiotic properties. In doing so, students employed research methods that are common to chemistry, biology and nanoscience while also learning about mechanism of infectious diseases, drugs and drug resistance. This project allowed students to combine aspects of scientific research that are usually done separately, and an opportunity to observe the seamlessness of multidisciplinary science.

Benzofuran sulfonates and small self-lipid antigens activate type II NKT cells via CD1d

Natural killer T (NKT) cells detect lipids presented by CD1d. Most studies focus on type I NKT cells that express semi-invariant αβ T cell receptors (TCR) and recognize α-galactosylceramides. However, CD1d also presents structurally distinct lipids to NKT cells expressing diverse TCRs (type II NKT cells), but our knowledge of the antigens for type II NKT cells is limited. An early study identified a nonlipidic NKT cell agonist, phenyl pentamethyldihydrobenzofuransulfonate (PPBF), which is notable for its similarity to common sulfa drugs, but its mechanism of NKT cell activation remained unknown. Here, we demonstrate that a range of pentamethylbenzofuransulfonates (PBFs), including PPBF, activate polyclonal type II NKT cells from human donors. Whereas these sulfa drug–like molecules might have acted pharmacologically on cells, here we demonstrate direct contact between TCRs and PBF-treated CD1d complexes. Further, PBF-treated CD1d tetramers identified type II NKT cell populations expressing αβTCRs and γδTCRs, including those with variable and joining region gene usage (TRAV12-1–TRAJ6) that was conserved across donors. By trapping a CD1d–type II NKT TCR complex for direct mass-spectrometric analysis, we detected molecules that allow the binding of CD1d to TCRs, finding that both selected PBF family members and short-chain sphingomyelin lipids are present in these complexes. Furthermore, the combination of PPBF and short-chain sphingomyelin enhances CD1d tetramer staining of PPBF-reactive T cell lines over either molecule alone. This study demonstrates that nonlipidic small molecules, which resemble sulfa drugs implicated in systemic hypersensitivity and drug allergy reactions, are targeted by a polyclonal population of type II NKT cells in a CD1d-restricted manner.

Benzofuran sulfonates and small self-lipid antigens activate type II NKT cells via CD1d

Natural Killer T (NKT) cells detect lipids presented by CD1d. Most studies focus on type I NKT cells that express semi-invariant αβ T cell receptors (TCR) and recognise α-galactosylceramides. However, CD1d also presents structurally distinct lipids to NKT cells expressing diverse TCRs (type II NKT cells) but our knowledge of the antigens for type II NKT cells is limited. An early study identified an NKT cell agonist, phenyl pentamethyldihydrobenzofuransulfonate (PPBF), which is notable for its similarity to common sulfa-drugs, but its mechanism of NKT-cell activation remained unknown. Here we demonstrate that a range of pentamethylbenzofuransulfonate (PBFs), including PPBF, activate polyclonal type II NKT cells from human donors. Whereas these sulfa drug-like molecules might have acted pharmacologically on cells, here we demonstrate direct contact between TCRs and PBF-treated CD1d complexes. Further, PBF-treated CD1d-tetramers identified type II NKT cell populations cells expressing αβ and γδTCRs, including those with variable and joining region gene usage (TRAV12-1–TRAJ6) that was conserved across donors. By trapping a CD1d-type II NKT TCR complex for direct mass spectrometric analysis, we detected molecules that allow binding of CD1d to TCRs, finding that both PBF and short-chain sphingomyelin lipids are present in these complexes. Furthermore, the combination of PPBF and short-chain sphingomyelin enhances CD1d tetramer staining of PPBF-reactive T cell lines over either molecule alone. This study demonstrates that non-lipidic small molecules, that resemble sulfa-drugs implicated in systemic hypersensitivity and drug allergy reactions, activate a polyclonal population of type II NKT cells in a CD1d-restricted manner.Significance StatementWhereas T cells are known to recognize peptide, vitamin B metabolite or lipid antigens, we identify several non-lipidic small molecules, pentamethylbenzofuransulfonates (PBFs), that activate a population of CD1d-restricted NKT cells. This represents a breakthrough in the field of NKT cell biology. This study also reveals a previously unknown population of PBF-reactive NKT cells in healthy individuals with stereotyped receptors that paves the way for future studies of the role of these cells in immunity, including sulfa-drug hypersensitivity.

Synthesis, Molecular Docking and Pharmacological Investigation of Some 4-Methylphenylsulphamoyl Carboxylic Acid Analogs

Compounds bearing and amino acid moieties are considered the basis for sulfa drug development. The synthesis of 4-methylphenylsulphamoyl acids and the evaluation of their pharmacological activities are reported. The synthesis of these compounds was accomplished by the reaction of various acids and 4-methyl chloride in basic aqueous solution. Structures were confirmed by FTIR, 1HNMR, 13CNMR spectra and elemental analytical data. Molecular docking interactions of the analogues were determined using PyRx. In the in antimicrobial activity analysis, compounds 1, 3, 5and 7 had antimicrobial inhibitory concentration range of 0.5-1.0mg/ml comparable with 0.1-2.0mg/ml of and . In the in anti-oxidant activity study compounds 1, 2and 6displayed half-maximal inhibitory concentrations (IC50) of 1.104±0.001 /ml, 1.159±0.002µg/ml and1.240±0.001µg/ml respectively comparable with 0.999±0.002µg/ml of acid. In the molecular docking study, compound 4 had a strong 2D binding interaction with II amino acid residue and compounds 1, 3, 4, 5, 6 and 7 had in antimicrobial, anti-oxidant, and antimalarial properties similar to their standard drugs. Considering the outstanding pharmacological properties and their strict compliance with Lipinski’s rule, the synthesized 4-methylphenylsulphamoyl analogues could be considered as antimicrobial, antimalarial, and anti-oxidant drug candidates.

Knowledge and Awareness about Antibiotic Usage and Emerging Drug Resistance Bacteria among Dental Students

Antibiotics are commonly used in dental practice. It has been estimated that 10% of all antibiotic prescriptions are related with dental infection. Antibiotic treatment is a feature of pharmacotherapy with the particularity of providing both prophylactic and curative action. It was introduced in the mid twentieth century in the form of sulfa drug (1935), penicillin (1941), tetracycline (1948) and erythromycin (1952). Since then, antibiotics have focused much clinical and pharmacological research, in response antibiotics, the consolidation of new disease, and novel clinical situations.to “Penicilin antibiotics are commonly use in dental practice. Amoxicillin, metronidozole and clavulanate are frequently prescribed drugs by dentists.” The aim of this study is to create knowledge and awareness about antibiotic usage and emerging drug resistance bacteria among dental students. The Questionnaires had been prepared and distributed to 100 participants of dental students. The resulting data have been analyzed using SPSS statistical software. Descriptive statistical analysis was carried out and chi square test was used and p value was calculated. Most of the participants in the survey were aware about antibiotic use and emerging drug resistance bacteria. From this present study, it can be concluded that the participants are aware about antibiotic usage and drug resistance bacteria.

517 ALDEN Based Determination of Culprit Drugs in Stevens-Johnson Syndrome: A 15-year Single Center Review

Introduction Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis Syndrome (TENS) are severe and potentially lethal adverse drug reactions characterized by acute inflammation and subsequent necrosis of the skin, mucous membranes, and ocular surface. SJS/TENS is defined on a spectrum based on the percent of total body surface area (%TBSA) with epidermal detachment: SJS (< 10% TBSA), Overlap Syndrome (10–30%), and TENS (>30%). The purpose of our study was to perform a systemic retrospective trend analysis of SJS spectrum diagnoses and culprit drugs in 147 patients admitted to the burn center over the past 15 years with the final diagnosis of SJS/TENS. The burn center serves as a regional referral center for patients with suspected or confirmed SJS/TENS. These referrals came from the five other academic medical centers as well as private hospitals in the area. Methods The electronic medical records of patients with a confirmed diagnosis of SJS/TENS admitted to the burn center from 2002 to 2017 were reviewed. Clinical data and the algorithm of drug causality for epidermal necrolysis (ALDEN) were used to identify the single most probable culprit drug. The following data were reviewed: date of admission, %TBSA with detachment, biopsy confirmation, and possible inciting agents. Chi-square tests were used to assess statistical significance for group comparisons. Results Over 15 years, 147 patients had a biopsy-confirmed diagnosis of SJS/TENS, of which 67% (n =98) had a culprit drug identified. The most common spectrum classification was TENS (n=73), followed by SJS (n=46) and Overlap Syndrome (n=27). Anticonvulsants (n=24), fluoroquinolones (n=14), allopurinol (n=11), sulfa drugs (n=9), and NSAIDs (n=9) were the most common inciting agents. Between 2006–2017, the proportion of patients presenting with SJS increased as compared to TENS and Overlap syndrome (10% in 2002–2009 vs. 42% in 2010–2017, p< 0.01). Sulfa drug reactions were more prevalent in recent years (0% in 2002–2009 vs. 18% in 2010–2017, p=0.065) and fluoroquinolone-induced reactions in earlier years (21% in 2002–2009 vs. 6% in 2010–2017, p=0.068). Conclusions This is one of the largest single center series of SJS/TENS/Overlap cases in the US. Our data supports trends presented in the EuroSCAR (1997–2001) and RegiSCAR (2003–2012) studies. Applicability of Research to Practice The ALDEN algorithm provides an important and validated method for determining the probable culprit drug in SJS/TENS spectrum reactions. Trends in culprit drugs can shift over time based on changes in prescribing practices. Therefore, these trends need to be monitored in order to advise providers on which agents present the greatest risk to patients.