Changing Landscape of Antimicrobial Resistance in Neonatal Sepsis: An in silico Analyses of Multidrug Resistance in Klebsiella pneumoniae.

BACKGROUND: Neonatal sepsis poses a critical healthcare concern, as multidrug-resistant Klebsiella pneumoniae (K. pneumoniae) infections are on the rise. Understanding the antimicrobial susceptibility patterns and underlying resistance mechanism is crucial for effective treatment. OBJECTIVES: This study aimed to comprehensively investigate the antimicrobial susceptibility patterns of K. pneumoniae strains responsible for neonatal sepsis using in silico tools. We sought to identify trends and explore reasons for varying resistance levels, particularly for ß-lactams and fluoroquinolone. METHODS: K. pneumoniae isolated from neonates at Kanchi Kamakoti CHILDS Trust Hospital (2017-2020) were analyzed for antimicrobial resistance. Elevated resistance to ß-lactam and fluoroquinolone antibiotics was further investigated through molecular docking and interaction analysis. ß-lactam affinity with penicillin-binding proteins and ß-lactamases was examined. Mutations in ParC and GyrA responsible for quinolone resistance were introduced to investigate ciprofloxacin interactions. RESULTS: Of 111 K. pneumoniae blood sepsis isolates in neonates, high resistance was detected to ß-lactams such as cefixime (85.91%, n = 71), ceftriaxone (84.9%, n = 106), cefotaxime (84.9%, n = 82) and fluoroquinolone (ciprofloxacin- 79.44%, n = 107). Molecular docking revealed low ß-lactam binding toward penicillin-binding proteins and higher affinities for ß-lactamases, attributing to the reduced ß-lactam efficiency. Additionally, ciprofloxacin showed decreased affinity toward mutant ParC and GyrA in comparison to their corresponding wild-type proteins. CONCLUSION: Our study elucidates altered resistance profiles in neonatal sepsis caused by K. pneumoniae, highlighting mechanisms of ß-lactam and fluoroquinolone resistance. It underscores the urgent need for the development of sustainable therapeutic alternatives to address the rising antimicrobial resistance in neonatal sepsis.

Computational study of the piperidine and FtsZ interaction in Salmonella Typhi: implications for disrupting cell division machinery.

FtsZ, a bacterial cell division protein, is essential for assembling the contractile Z-ring crucial in bacterial cytokinesis. Consequently, inhibiting FtsZ could impede proto-filaments, disrupting FtsZ and other associated proteins vital for cell division machinery. Conduct an in-silico drug interaction study to identify novel drug candidates that inhibit the FtsZ protein, aiming to prevent Multi-Drug Resistant (MDR) Salmonella Typhi. Data mining was performed based on piperidine compounds, which were subsequently screened for safe pharmacokinetic profiles. Compounds that met favorable drug-likeness criteria underwent virtual screening against the FtsZ drug target. Two compounds were chosen for molecular docking and molecular dynamic simulation to verify the binding affinity and stability between the target protein and the potential compounds. The 400 isoforms of piperidine analogues were curated, among them potent compound ZINC000000005416 found to possess high binding affinity (-8.49 kcal/mol) and low dissociation constant (0.597 µM). The highest binding affinity shown by ZINC000000005416 was validated by hydrogen bonds, hydrophobic interaction, and salt bridges with the functional domain of the cell division regulatory protein. Docking profiles, when correlated with molecular dynamic simulation (MDS) depicted stable trajectories and compatible conformational changes in the FtsZ-ZINC000000005416 complex. The stable simulated trajectories were validated through free-energy calculations using the Molecular Mechanics-Poisson Boltzmann Surface Area (MM/PBSA) module. Low energy conformations, although the simulation trajectory confirmed the stable ZINC000000005416-FtsZ interaction, which encouraged experimental validations. This study encourages further exploration of the compound ZINC000000005416 as a drug candidate inhibiting FtsZ protein against MDR Salmonella Typhi.Communicated by Ramaswamy H. Sarma.

Emergence of sulphonamide resistance in azithromycin-resistant pediatric strains of Salmonella Typhi and Paratyphi A: A genomics insight.

Whole genome sequences of Salmonella enterica subspecies enterica serovar Typhi (S. Typhi) and Salmonella enterica subspecies enterica serovar Paratyphi A (S. Paratyphi A) from pediatric settings were used to assess the emerging Antimicrobial Resistance (AMR). The high throughput sequences of twenty pediatric clinical isolates of S. Typhi and S. Paratyphi A were retrieved and were screened for prevalent Antimicrobial Resistance Genes (ARGs) and Virulent Factors (VF). The resistance data was compared with the reference strains of S. Typhi and S. Paratyphi A. AMR studies identified sul1, sul2, dfrA7, tem-1, AH(6)-Id and APH(3″)-Ib as common ARGs. VFs were identified to understand the level of pathogenicity. The most prevalent AMR genes in the sequenced genomes were detected in phenotypically azithromycin-resistant S. Typhi. Correlation with the global genomes projected a trend of concurrent resistance to macrolides, ß lactams, fluoroquinolones (FQs), tetracyclines, ansamycins, and aminoglycosides. Traces of sulphonamide-resistance were observed indicating the emergence of a currently non-prevalent S. Typhi resistance that could be a future threat. Hence new antibiotic regimen to treat azithromycin-resistant S. Typhi should be formulated by avoiding the risks of aggravating sulphonamide resistance. The identified ARGs in genomes from paediatric isolates will aid future studies to design anti-bacterial compounds against S. Typhi and S. Paratyphi A.

Bioactive phytocompounds against specific target proteins of Borrelia recurrentis responsible for louse-borne relapsing fever: Genomics and structural bioinformatics evidence.

Louse-borne relapsing fever (LBRF) with high untreated mortality caused by spirochete Borrelia recurrentis is predominantly endemic to Sub-Saharan Africa and has re-emerged in parts of Eastern Europe, Asia and Latin America due to population migrations. Despite subtractive evolution of lice-borne pathogenic Borrelia spp. from tick-borne species, there has been no comprehensive report on conservation of protein targets across tick and lice-borne pathogenic Borrelia nor exploration of phytocompounds that are toxic to tick against lice. From the 19 available whole genomes including B. recurrentis, B. burgdorferi, B. hermsii, B. parkeri and B. miyamotoi, conservation of seven drug targets (>80% domain identity) viz. 30 S ribosomal subunit proteins (RSP) S3, S7, S8, S14, S19, penicillin-binding protein-2 and 50 S RSP L16 were deciphered through multiple sequence alignments. Twelve phytocompounds (hydroxy-tyrosol, baicalein, cis-2-decanoic acid, morin, oenin, rosemarinic acid, kaempferol, piceatannol, rottlerin, luteolin, fisetin and monolaurin) previously explored against Lyme disease spirochete B. burgdorferi when targeted against LBRF-causing B. recurrentis protein targets revealed high multi-target affinity (2%-20% higher than conventional antibiotics) through molecular docking. However, based on high binding affinity against all target proteins, stable coarse-grained dynamics (fluctuations <1 Å) and safe pharmacological profile, luteolin was prioritized. The study encourages experimental evaluation of the potent phytocompounds and similar protocols for investigating other emerging vector-borne diseases.

Network metrics, structural dynamics and density functional theory calculations identified a novel Ursodeoxycholic Acid derivative against therapeutic target Parkin for Parkinson's disease.

Parkinson's disease (PD) has been designated as one of the priority neurodegenerative disorders worldwide. Although diagnostic biomarkers have been identified, early onset detection and targeted therapy are still limited. An integrated systems and structural biology approach were adopted to identify therapeutic targets for PD. From a set of 49 PD associated genes, a densely connected interactome was constructed. Based on centrality indices, degree of interaction and functional enrichments, LRRK2, PARK2, PARK7, PINK1 and SNCA were identified as the hub-genes. PARK2 (Parkin) was finalized as a potent theranostic candidate marker due to its strong association (score > 0.99) with α-synuclein (SNCA), which directly regulates PD progression. Besides, modeling and validation of Parkin structure, an extensive virtual-screening revealed small (commercially available) inhibitors against Parkin. Molecule-258 (ZINC5022267) was selected as a potent candidate based on pharmacokinetic profiles, Density Functional Theory (DFT) energy calculations (ΔE = 6.93 eV) and high binding affinity (Binding energy = -6.57 ± 0.1 kcal/mol; Inhibition constant = 15.35 µM) against Parkin. Molecular dynamics simulation of protein-inhibitor complexes further strengthened the therapeutic propositions with stable trajectories (low structural fluctuations), hydrogen bonding patterns and interactive energies (>0kJ/mol). Our study encourages experimental validations of the novel drug candidate to prevent the auto-inhibition of Parkin mediated ubiquitination in PD.