Evaluation of phyto-gallic acid as a potential inhibitor of Staphylococcus aureus efflux pump mediated tetracycline resistance: an in-vitro and in-silico study.

Plants contain many bioactive compounds with potent antibacterial and efflux pump inhibitory activity (EPI). In this study, gallic acid extracted from pomegranate molasses by analytical HPLC holds promise as an EPI drug for Staphylococcus aureus mediated tetracycline resistance, it lowered the bacterial resistance and reversed the mechanism via tet family efflux pump, using molecular technique and in-silico molecular docking analysis. Extracted gallic acid combined with tetracycline demonstrated a significant decrease in the minimal inhibitory concentration MIC compared to its single activity. Similarly, little growth and lower fluorescence of S. aureus were observed on ethidium bromide (2.5 mg/mL) agar plates, indicating a reversible efflux pump mechanism and a potent EPI activity. Molecular docking demonstrated a promising affinity binding energy between gallic acid and tet efflux genes, opening a new baseline in bacterial infection treatment. PCR for tetK and Qac A/B genes failed to show any relation between tet genes and gallic acid.

The Implementation of HIV Self-Testing in Resource-Limited Settings Where the HIV Disease Burden is High.

In resource-limited settings, there is growing evidence that HIV testing is lacking among high-risk key populations such as men having sex with men, injection drug users, and transgenders largely due to stigma, discrimination, and lack of confidentiality. Findings from recent studies among high-risk key populations and the general population from various regions including resource-limited settings support the need for wider accessibility of HIV self-testing (HIV-ST) to reach those who may not otherwise have access to testing. Therefore, HIV-ST has untapped potential as a strategy to improve access to HIV testing and to increase testing frequency among key high-risk populations and their partners. Though HIV-ST has emerged as a safe, acceptable, and effective way to reach people, there are several roadblocks to implementing the HIV-ST policy, and fast-track policy implementation needs to be necessitated with newer or modified strategic plans.

Moonlighting proteins [ML proteins]: The pandora's box of insidious oro-dental diseases.

Oral pathogens survive in the harsh niche of the oral microbiome on account of a plethora of moonlighting [ML] proteins that can multitask in the oro-mucosal layers. ML proteins are considered as the complex protein hyperspace expressed in many oral bacterial pathogens and encompass many hypothetical and experimentally evidenced proteins that can efficiently assist in the initiation and progression of various oro-dental infections. With the propensity of multi-drug resistance and biofilm formation, unravelling the mysterious functions associated with the oral ML proteins could be essential in targeting the vital oral bacteria and their associated infections. This commentary thus throws insights onto the key clues on various ML proteins that can be considered for the development of therapeutic versatility to curtail the complications caused by various oral bacterial species.

Protean role of epigenetic mechanisms and their impact in regulating the Tregs in TME.

Constitutive expression of Foxp3+ Tregs in the tumor microenvironment (TME) specifically renders immune suppression in the tumor tissues. Being highly stable and self-tolerant, Tregs may be influenced by various epigenetic-associated mechanisms while exhibiting their functions. DNA methylation, histone acetylation, epigenetic silencing, alteration in chromatin networks, etc., are some of the main factors underlying the epigenetic-based Treg cell functional modulations in the TME. The possible reasons on why these epigenetic modulations should be specifically targeted are thus discussed, so that enhanced anti-tumor immunity in TME can be achieved.

Characterization of biofilm producing methicillin resistant coagulase negative Staphylococci from India.

Methicillin-resistant coagulase-negative staphylococci (MR-CoNS) cause infectious diseases due to their potential to form biofilm and further colonization in hospital materials. This study evaluated the antibiotic susceptible phenotypes, biofilm-producing ability, and biofilm-associated genes (mecA, icaAD, bap, cna, and fnbA). Biofilm formation was detected through Congo red agar (CRA) method and MTP method. The presence of biofilm and associated genes in MR-CoNS were detected by PCR. A total of 310 (55.95%) isolates produced the biofilm. Among these isolates, Staphylococcus haemolyticus (34.83%), Staphylococcus epidermis (31.93%), Staphylococcus capitis (16.77%), Staphylococcus cohnii (10.96%), and Staphylococcus hominis (5.48%) were identified. The antimicrobial susceptibility pattern of CoNS isolates indicated resistance to cefoxitin (100%), erythromycin (94.8%), ciprofloxacin (66.7%), sulfamethoxazole/trimethoprim (66.7%), gentamicin (66.12%), and clindamycin (62.9%). Resistance rate to mupirocin was 48.5% in S. epidermidis and 38.9% in S. haemolyticus isolates. All isolates were sensitive to vancomycin and linezolid. The prevalence rates of icaAD, bap, fnbA, and cna were 18.06%, 12.5%, 47.4%, and 27.4%, respectively. icaAD and bap genes were detected in 18.06% and 12.5% of MR-CoNS isolates. fnbA and cna genes were detected in 47.41% and 27.41% of MRCoNS isolates. icaAD positive strains exhibited a significant increase in the biofilm formation compared with those that lacked icaAD (0.86 (0.42, 1.39) versus 0.36 (0.14, 0.75), respectively; P < 0.001). In conclusion, the majority of MR-CoNS isolates were biofilm producers, and S. capitis, which possessed icaAD genes, ranked as the great biofilm producer than other Staphylococcus. The study's findings are important to form a strategy to control biofilm formation as an alternative strategy to counter the spread of MR-CoNS in healthcare settings.

Virulence of Acinetobacter baumannii in proteins moonlighting.

The diverse function of the moonlighting proteins in Acinetobacter baumannii is highly associated with its virulence that had spurred renewed attention in recent years. The existing and newly formed hypothetical moonlighting proteins, evolve without jeopardizing the structural constraints of their original roles. It is yet uncertain and undefined to lucidly describe the functions of the moonlighting proteins in A. baumannii albeit its overwhelming evidences on few proteins. This commentary thus highlights the expression and occurrence of potent moonlighting proteins in A. baumannii, rendering virulence to the strains and the reasons to target the same portraying an active arena of research.

Genetic alterations in Wnt family of genes and their putative association with head and neck squamous cell carcinoma.

Head and neck squamous cell carcinoma (HNSCC) is the most frequent type of head and neck cancer that usually arises from the mucosal surfaces of several organs including nasal cavity, paranasal sinuses, oral cavity, tongue, pharynx, and larynx. The Wnt signaling pathway is a crucial mechanism for cellular maintenance and development. It regulates cell cycle progression, apoptosis, proliferation, migration, and differentiation. Dysregulation of this pathway correlates with oncogenesis in various tissues including breast, colon, pancreatic as well as head and neck cancers. The present study aims to assess the gene alterations in the Wnt family of genes so as to derive an association with HNSCC. Computational approaches have been utilized for the identification of gene alterations in the Wnt family of genes. Several databases such as cBioportal, STRING, and UALCAN were used for the purpose. The frequency of alteration was high in case of Wnt family member 11 (5%). Gene amplification, deep deletions, missense and truncating mutations were observed in HNSCC patients. There was a marked difference in the gene expression profile of WNT11 between grades as well as normal samples. The survival probability measured using the Kaplan-Meier curve also presented with a significant difference among male and female subjects experiencing a low/medium level expression. The female patients showed less survival probability when compared to the male subjects. This provides the prognostic significance of the WNT11 gene in HNSCC. Taken together, the present study provides clues on the possible association of WNT11 gene alterations with HNSCC, which has to be further validated using experimental approaches.

Protein targets in red complex pathogens for catechin.

The development of antimicrobial drug resistance has encouraged scientists to develop alternate methods to combat infectious pathogens associated with dental diseases. Therefore, it is of interest to predict interactions for catechin (a plant derived compound) with protein targets in the red complex pathogens using computer aided network tools. However, in vitro and in vivo studies are warranted to confirm the antimicrobial effect of catechin (gallocatechin, epicatechin, epigallactocatechin (EGC) and gallolyl catechins) on the dental pathogens.

Genistein binding protein targets in dental pathogens.

Oral pathogens have created a menace in recent years due to biofilm formation and antimicrobial drug resistance. The current treatment strategy works well with antibiotics. However, constant use of antibiotics creates a selective pressure, which increases adaptability of the pathogens. Therefore, it is of interest to analyze the potential targets of genistein in dental pathogens using computer aided prediction tools.

An in silico approach towards identification of virulence factors in red complex pathogens targeted by reserpine.

Oral cavity hosts an exhaustive collection of microorganisms which are known to be associated with disease such as dental caries, periodontal and deep-seated infections. Elimination of these pathogens from the site of infection remains a perplexing task, which demands the use of antibiotics. The emergence of drug resistant forms has spurred interest into identifying novel therapeutic targets against these pathogens. In this context, the present study has been designed to analyse and identify potential drug targets of the phytocompound reserpine in red complex pathogens. Computational tools were used to identify the targets, assess its functional role and virulence property. Further, the peptide epitopes present in the virulence factors were identified using BepiPred tool. The subcellular location of the virulence proteins were also elucidated using PSORTb. Reserpine was found to target vital protein transporters such as ABC transporter and efflux pumps which are known to play a crucial role in the survival of bacterial cells. Hence the present in silico study provides substantial evidence on the anti-bacterial activity of reserpine against red complex pathogens. However, in vitro studies using the compound is warranted to further confirm the efficacy of the compound.

Delineating the Immuno-Dominant Antigenic Vaccine Peptides Against gacS-Sensor Kinase in Acinetobacter baumannii: An in silico Investigational Approach.

OBJECTIVES: To predict the novel vaccine peptide candidates against gacS protein involved with the citrate utilization in the two-component system of A. baumannii-associated virulence as an alternative strategy to combat the multi-drug resistant strains using an immuno-informatic approach. METHODS: The study is designed as an observational in silico study design with the application of BepiPred, AlgPred, VaxiJen, AntigenPro, SolPro, Expasy ProtParam server, IEDB database, and MHC cluster analytical tools and servers to predict the immuno-dominant B-cell and T-cell epitopes from gacS FASTA sequences retrieved from UNIPROT database. Further peptide interactions with TLR-4 was assessed based on the number of hydrogen bonds. RESULTS: Nine peptides (20aa) with the highest score of 1 were selected from the 137 epitopes, and five were predicted as antigenic epitopes (E1-E5). E3 was selected as the potent antigen (score: 0.939537) and E1 as the best vaccine candidate (score: 0.9803) under AntigenPro and Vaxijen server, respectively. SolPro predicted all epitopes as soluble peptides. ProtParam predictions showed E3 and E5 as stable proteins with a shelf life of 3.5 and 1.9 h and possessed negative GRAVY values. PsortB server predicted a final localization score of 7.88 for the gacS protein sequence as a cytoplasmic membrane protein. IEDB conservancy analysis showed 100% conserved sequences within the gacS sequence, and class I conservancy yielded positive values for all epitopes. Cluster analysis showed strong interactions, and the protein-peptide interactions with TLR-2 finally detected E5 as the best interacting peptide (H bonds = 14) followed by E3 (H bonds = 12). CONCLUSION: The study suggests five antigenic peptides as promiscuous vaccine candidates to target the gacS of A. baumannii using immuno-informatic approach toward the peptide synthesis and in vitro analysis. However, the study recommends further experimental validation for immunological response and memory through in vivo studies.

A computational study targeting the mutated L321F of ERG11 gene in C. albicans, associated with fluconazole resistance with bioactive compounds from Acacianilotica.

BACKGROUND: Emergence of fluconazole resistance mediated by L321F mutation in the ERG11 gene poses a serious impediment in the candidal treatment process. This leads to the search of novel target proteins to develop newer drugs against fluconazole resistant C. albicans. The present investigation is thus aimed to explore the inhibitory potential of bioactive compounds from A. nilotica against the wild and mutated ERG11 gene of C. albicans. MATERIALS AND METHODS: Homology modelling of the wild and mutated ERG11 target gene was done by Modeller 9.2, with SDM I-mutant form of ERG11 together with SAVES server and Ramachandran plot validation. 2D and 3D structures of the bioactive compounds from A. nilotica were optimized by ACD chemsketch. Molinspirational assessments for the molecular properties of the ligands and their drug likeliness were estimated. In silico inhibitory potential of the selected ligands against wild and mutated ERG11 was done by AutoDock 2.0 and was visualized with Accelrys discovery studio tool. RESULTS: Apigenin proved to be the best candidate to target mutant ERG11 with a binding energy of -8.33 Kcal/mol followed by catechin with six hydrogen bonds with more drug likeliness. Molinspiration assessments showed zero violations for all the bioactive compounds from A. nilotica and the TPSA scores of the ligands showed the values<140Å towards the best oral bio-availability. CONCLUSION: The findings of the study emphasize that kaempferol, apigenin and catechin from A. nilotica seem to possess a promising inhibitory effect against the wild and mutated ERG11 of C. albicans suggesting ERG11 as the best target to combat fluconazole resistant C. albicans with further in vivo validation targeting the same.

In silico analysis of virulence genes in an emerging dental pathogen A. baumannii and related species.

OBJECTIVES: Acinetobacter baumannii is an opportunistic pathogen which has recently been categorized as a high risk pathogen by World Health Organisation (WHO). The microbe has stealthily entered the oral cavity and has established itself as a potential pathogen by acquiring drug resistance and expression of several virulence genes. Surveillance on the type of virulence factors harboured by the organism will enable us to comprehend the mechanism of pathogenesis. The study was performed to screen for the presence of crucial virulence factors associated with Acinetobacter spp. as reviewed from the literature by employing computational tools. DESIGN: Nineteen genome sequences of Acinetobacter spp. with the predominance of different strains of A. baumannii were classified phylogenetically into clusters using in silico restriction digestion and pulse field gel electrophoresis (PFGE). Further, the frequency of common virulence genes in the genome of various Acinetobacter spp. was recorded using in silico PCR analysis. RESULTS: Based on PFGE pattern and phylogenetic tree the genomes of A. baumannii were clustered into 4 genotypes (G1-G4). Two species were excluded from the list since they were negative for almost all the virulence genes tested. Frequency of virulence genes in each of the 17 genomes analysed, found ompA and smpA to be the major virulence factors in A. baumannii and related species. Acinetobacter spp. belonging to genotypes 2 and 3 were found to harbour 1-15 and 6-10 potential genes encoding virulence factors respectively. CONCLUSIONS: The present study showed numerous virulence genes in genomes analysed. In silico analysis of these virulence genes can be used as candidates to build novel therapeutic targets against the pathogen. An extensive study on the functional role of these genes could aid in stalling the propagation and dissemination of A. baumannii among susceptible individuals.

An insight into the emergence of Acinetobacter baumannii as an oro-dental pathogen and its drug resistance gene profile - An in silico approach.

BACKGROUND: Acinetobacter baumannii, a potential nosocomial pathogen has stealthily gained entry into the oral cavity. Their association with other pathogens like Pseudomonas aeruginosa in chronic and aggressive periodontitis cases is well documented. The magnitude of problem caused by A . baumannii could be attributed to resistance genes acquired by the organism. Since the microbiome of oral cavity is heterogeneous and complex, the transfer of genes from multidrug resistant A . baumannii may be a serious threat in infection control and management. In view of this fact, the present study aims to categorize and characterize drug resistant genes present in each of the 19 genomes of Acinetobacter Sp. selected for the study. METHODS: About 19 genome sequences of Acinetobacter spp. with the predominance of different strains of A . baumannii was genotyped using in silico restriction digestion and pulse field gel electrophoresis (PFGE). Further, the prevalence of common drug resistant genes in the genome of various Acinetobacter spp. was recorded using in silico PCR analysis. RESULTS: Based on the PFGE pattern, phylogenetic tree was constructed and the genomes were clustered into 6 genotypes. Genotype 4 (n = 8; 42.10%) and 5 (n = 6; 31.57%) were predominant, followed by genotypes 2 (n = 2; 10.52%), 1, 3 and 6 (n = 1; 5.26%). Three species were excluded from the list since they were negative for most of the drug resistant genes tested. Prevalence of drug resistant genes in each of the 16 genomes analysed found oxa-51, ISAba 1 and ADC 1 to be the major genes found in A . baumannii. Acinetobacter spp. belonging to genotypes 4 and 5 were found to harbour 6-10 and 2-8 potential drug resistant genes respectively. CONCLUSION: The present study showed cluster of multi-drug resistant genes in genomes analysed, thus, warranting the need for antibiotic surveillance, alternate therapeutic measures and development of novel antimicrobials. An extensive study on the genes conferring drug resistance in this pathogen will open new avenues for battling the entry and spread of this pathogen in vulnerable patient groups.

A preliminary study on the screening of emerging drug resistance among the caries pathogens isolated from carious dentine.

BACKGROUND: Dental caries being the commonest unmet public health problem indicates its need to urge the dentists to overcome this problem globally. Caries exhibit in different types and is found to be associated with co-aggregation property of microbial flora with other oral hygienic factors. In spite of the surgical removals, excavations and administration of antimicrobials for carious dentine, there seems to be repeated infection and chronic prevalence of caries. A complete understanding of microbial etiology and prevention of emerging drug-resistant strains will aid in the eradication of this chronic dentine problem condition from the oral cavity. AIM: This study is aimed to isolate the predominant bacterial pathogens associated with caries and to screen for the emergence of drug resistance among the isolated caries pathogens. MATERIALS AND METHODS: Carious dentine specimens were collected from 75 endodontic patients and the samples were processed microbiologically to isolate the caries pathogens. Identification of the strains was done by standard biochemical characterization studies. Statistical analysis of the isolates was done by Pearson Chi-square test and Fisher's exact test. The predominant isolates were subjected to antimicrobial sensitivity test using Kirby Bauer's method. The results were recorded and analyzed for drug resistance. RESULTS: Carious dentine samples yielded a high percentage of Lactobacillus sp., and Candida albicans from different type of caries. Among the study population, dentinal caries was the most predominant type affecting most males with other associated risk factors. Nearly 47.3% of the isolated Lactobacillus sp. and 55.5% of the yeast C. albicans were screened to show resistance against the antimicrobials used for the study. CONCLUSION: This study concludes by stating that Lactobacillus sp., and C. albicans are mostly involved in the caries etiology and show resistance to the commonest antimicrobial agent. This implicates the need for periodical antimicrobial susceptibility examination of the caries pathogens that will aid to prevent the emergence of resistance property among the dentinal pathogenic organisms.