Pathogenic Bacterial Species Research Articles

Bacteriolytic Potential of Enterococcus Phage iF6 Isolated from "Sextaphag®" Therapeutic Phage Cocktail and Properties of Its Endolysins, Gp82 and Gp84.

The number of infections caused by antibiotic-resistant strains of bacteria is growing by the year. The pathogenic bacterial species Enterococcus faecalis and Enterococcus faecium are among the high priority candidate targets for the development of new therapeutic antibacterial agents. One of the most promising antibacterial agents are bacteriophages. According to the WHO, two phage-based therapeutic cocktails and two medical drugs based on phage endolysins are currently undergoing clinical trials. In this paper, we describe the virulent bacteriophage iF6 and the properties of two of its endolysins. The chromosome of the iF6 phage is 156,592 bp long and contains two direct terminal repeats, each 2108 bp long. Phylogenetically, iF6 belongs to the Schiekvirus genus, whose representatives are described as phages with a high therapeutic potential. The phage demonstrated a high adsorption rate; about 90% of iF6 virions attached to the host cells within one minute after the phage was added. Two iF6 endolysins were able to lyse enterococci cultures in both logarithmic and stationary growth phases. Especially promising is the HU-Gp84 endolysin; it was active against 77% of enterococci strains tested and remained active even after 1 h incubation at 60 °C. Thus, iF6-like enterococci phages appear to be a promising platform for the selection and development of new candidates for phage therapy.

A Longitudinal Characterization of the Seminal Microbiota and Antibiotic Resistance in Yearling Beef Bulls Subjected to Different Rates of Gain.

In this study, we evaluated the seminal and fecal microbiota in yearling beef bulls fed a common diet to achieve moderate (1.13 kg/day) or high (1.80 kg/day) rates of weight gain. Semen samples were collected on days 0 and 112 of dietary intervention (n = 19/group) as well as postbreeding (n = 6/group) using electroejaculation, and the microbiota was assessed using 16S rRNA gene sequencing, quantitative PCR (qPCR), and culturing. The fecal microbiota was also evaluated, and its similarity with seminal microbiota was assessed. A subset of seminal bacterial isolates (n = 33) was screened for resistance against 28 antibiotics. A complex and dynamic microbiota was detected in bovine semen, and the community structure was affected by sampling time (R2 = 0.16, P < 0.001). Microbial richness increased significantly from day 0 to day 112, and diversity increased after breeding (P > 0.05). Seminal microbiota remained unaffected by the differential rates of gain, and its overall composition was distinct from fecal microbiota, with only 6% of the taxa shared between them. A total of 364 isolates from 49 different genera were recovered under aerobic and anaerobic culturing. Among these seminal isolates were pathogenic species and those resistant to several antibiotics. Overall, our results suggest that bovine semen harbors a rich and complex microbiota which changes over time and during the breeding season but appears to be resilient to differential gains achieved via a common diet. Seminal microbiota is distinct from the fecal microbiota and harbors potentially pathogenic and antibiotic-resistant bacterial species. IMPORTANCE Increasing evidence from human and other animal species supports the existence of a commensal microbiota in semen and that this seminal microbiota may influence not only sperm quality and fertility but also female reproduction. Seminal microbiota in bulls and its evolution and factors shaping this community, however, remain largely underexplored. In this study, we characterized the seminal microbiota of yearling beef bulls and its response to the bull age, different weight gains, and mating activity. We compared bacterial composition between seminal and fecal microbiota and evaluated the diversity of culturable seminal bacteria and their antimicrobial resistance. Our results obtained from sequencing, culturing, and antibiotic susceptibility testing provide novel information on the taxonomic composition, evolution, and factors shaping the seminal microbiota of yearling beef bulls. This information will serve as an important basis for further understanding of the seminal microbiome and its involvement in reproductive health and fertility in cattle.

Epidemiology and Risk Factors of Community-Associated Bloodstream Infections in Zhejiang Province, China, 2017-2020.

Community-associated bloodstream infection (CA-BSI) is increasing in many community settings. However, the clinical significance and epidemiology of CA-BSI present in hospital admissions in China are not well established. In this work, we identified the risk factors in outpatients presenting with CA-BSI, and investigate the role of procalcitonin (PCT) and hypersensitive C-reactive protein (CRP) in diagnosing different types of the pathogen in patients with acute CA-BSI. A retrospective study enrolling 219 outpatients with CA-BSI from The Zhejiang People's Hospital from January 2017 to December 2020 was performed. Susceptibility of the isolates obtained from these patients was examined. Subjecting receiver operating characteristic curves (ROC) were constructed to analyze the specificity and sensitivity of PCT, CRP, and WBC in determining infections caused by different bacterial genera. Risk factors for CA-BSI in the emergency setting were analyzed using essential information and simple identification of other pathogenic bacterial species through rapidly tested biomarkers. A total of 219 patients were included in the selection criteria, of which 103 were infected with Gram-positive bacteria (G+) and 116 with Gram-negative bacteria (G-). The PCT was significantly higher in the GN-BSI group than in the GP-BSI group, while no significant difference was observed between the two groups for CRP. Subjecting ROC curves were constructed to analyze WBC, CRP, and PCT, and the area under the curve (AUC) of the PCT in this model was 0.6661, with sensitivity = 0.798 and specificity = 0.489. The PCT between the GP-BSI group and the GN-BSI group was significantly different. By combining the knowledge of clinicians and the clinical signs of patients, PCT should be utilized as a supplementary approach to initially determine pathogens and direct medication in the early stages of clinical practice.

A new and accurate qPCR protocol to detect plant pathogenic bacteria of the genus ‘Candidatus Liberibacter’ in plants and insects

Four pathogenic bacterial species of the genus ‘Candidatus Liberibacter’, transmitted by psyllid vectors, have been associated with serious diseases affecting economically important crops of Rutaceae, Apiaceae and Solanaceae families. The most severe disease of citrus plants, huanglongbing (HLB), is associated with ‘Ca. Liberibacter asiaticus’ (CaLas), ‘Ca. Liberibacter americanus’ (CaLam) and ‘Ca. Liberibacter africanus’ (CaLaf), while ‘Ca. Liberibacter solanacearum’ (CaLsol) is associated with zebra chip disease in potatoes and vegetative disorders in apiaceous plants. Since these bacteria remain non-culturable and their symptoms are non-specific, their detection and identification are done by molecular methods, mainly based on PCR protocols. In this study, a new quantitative real-time PCR protocol based on TaqMan probe, which can also be performed in a conventional PCR version, has been developed to detect the four known phytopathogenic species of the genus Liberibacter. The new protocol has been validated according to European Plant Protection Organization (EPPO) guidelines and is able to detect CaLas, CaLam, CaLaf and CaLsol in both plants and vectors, not only using purified DNA but also using crude extracts of potato and citrus or psyllids. A comparative analysis with other previously described qPCR protocols revealed that this new one developed in this study is more specific and equally or more sensitive. Thus, other genus-specific qPCR protocols have important drawbacks regarding the lack of specificity, while with the new protocol there was no cross-reactions in 250 samples from 24 different plant and insect species from eight different geographical origins. Therefore, it can be used as a rapid and time-saving screening test, as it allows simultaneous detection of all plant pathogenic species of ‘Ca. Liberibacter’ in a one-step assay.

Impacts of dietary supplementation of bamboo vinegar and charcoal powder on growth performance, intestinal morphology, and gut microflora of large-scale loach Paramisgurnus dabryanus.

Although accumulating data demonstrate that dietary supplementation of bamboo vinegar and charcoal powder (BVC) can significantly strengthen the immunity and boost the growth of domestic animals, its application potency still awaits verification in commercial fish species such as the large-scale loach Paramisgurnus dabryanus. The impacts of 90-day dietary supplementation of 1% and 2% BVC on survival and growth performance of the loach, and on the intestinal morphological characteristics and gut microflora were analyzed. Our data show that the large-scale loach supplied with BVC at the experimental doses had significant higher survival rates and better growth performance (indicated by greater weight gain (1.13-1.14 times), higher specific growth rate (1.04 times), and lower feed conversion ratio (0.88-0.89 times)) compared to that of the control (P<0.05). Histological examination revealed significant longer villus (3.22-5.54 times), deeper crypt (1.77-1.87 times), and thicker muscle (1.59-3.17 times) in the intestines of large-scale loach fed with BVC (P<0.05). Furthermore, we found that the gut microflora consisted of significantly fewer proportions of potential pathogenic bacterial species (Aeromonas veronii and Escherichia coli), but significantly greater proportions of beneficial microbes (Lactococus raffinolactis and Faecalibacterium prausnitzii). Therefore, dietary intake of BVC can promote intestinal tract development and optimize gut microflora, by which the survival and growth of large-scale loach may be improved.

Anticancer properties of curcumin-treated Lactobacillus plantarum against the HT-29 colorectal adenocarcinoma cells

Probiotic bacteria with functions of importance to the health and well-being of the host exhibit various medicinal properties including anti-proliferative properties against cancer cells. There are observations demonstrating probiotic bacteria and their metabolomics can be different in various populations with different eating habits. Here, Lactobacillus plantarum was treated with curcumin (the major compound of turmeric), and its resistance to the curcumin was determined. After then the cell-free supernatants of untreated bacteria (CFS) and bacteria treated with curcumin (cur-CFS) were isolated and their anti-proliferative properties against HT-29 colon cancer cells were compared. The ability of L. plantarum treated with curcumin to combat a variety of pathogenic bacterial species and its ability to survive in acidic conditions were evidence that the probiotic properties of the bacterium were unaffected by the curcumin treatment. L. plantarum treated with curcumin and intact L. plantarum were both able to live in acidic conditions, according to the results of the resistance to low pH test. The MTT result showed that CFS and cur-CFS dose-dependently decreased the growth of HT29 cells with a half-maximal inhibitory concentration of 181.7 and 116.3 µL/mL at 48 h, respectively. Morphological alteration of DAPI-stained cells also exhibited significant fragmentation in the chromatin within the nucleus of cur-CFS-treated cells compared to CFS-treated HT29 cells. Moreover, flow cytometry analyses of apoptosis and cell cycle confirmed DAPI staining and MTT assay results and stipulated the increased occurrence of programmed cell death (apoptosis) in cur-CFS-treated cells (~ 57.65%) compared to CFS-treated cells (~ 47%). These results were more confirmed with qPCR and exhibited the upregulation of Caspase 9–3 and BAX genes, and downregulation of the BCL-2 gene in cur-CFS- and CFS-treated cells. In conclusion, turmeric spice and curcumin may affect the metabolomics of probiotics in intestinal flora which could subsequently influence their anticancer properties.

Determine the Ability of Bacterial Isolates from Urinary Tract Infections on L-Asparginase Production

This study was conducted to isolate and identify the pathogenic bacterial species from urinary tract of patients that reviewers to Tikrit hospital education from tow gender and different age periods. It was also the determination of bacterial species isolated in their ability to production of the L-asparginase enzyme and assay the environmental conditions and the production media ingredients for high concentration of enzyme production. Results showed that 142 samples was positive in microbial isolation (91.64%) from the total study samples that were at 150 samples, and high isolation percentage was from female at 58% and from aged period between 15 to 75 years for two gender. It also found that the species of bacterial E.coli was appear as highest in isolation percentage followed by Citrobacter diversus, Enterobacter aerogenes and Klebsiella pneumonia which was at 54.2, 21.1, 17.6 and 7.04% respectively. The assay of bacterial isolates to L-asparginase produce illustrate that the E.coli species appear as the most production and the isolate no. 3 was the top one at 70.4 IU/ml of media. When the assay of environmental conditions and ingredients combination for media to access for higher production from enzyme, shows that the optimal conditions for production of E.coli-Iso.3 was in development at 35 º c, pH 7.0 for 24 hours with agitation at 150 rpm in the media consists of maltose, L-asparginase, NaCl and KH2PO4 at 10, 100, and 5.0 and 0.75 g/l respectively.

The transmittable through stinging microbiota differs between honeybees and wasps: a potentially greater microbial risk of the wasp sting for humans

The present research investigated whether accidental contact through stinging with honeybees, wasps, and hornets could represent a microbial hazard for humans. It has been previously suggested that such contact may transmit pathogens causing infections that could even be fatal for some susceptible individuals. Stinging simulation experiments were performed in the lab with live insects collected from the environment in Lemnos Island (north-eastern Greece), while different selective agar media targeting some clinically important bacteria (i.e., Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecalis/faecium, and Pseudomonas aeruginosa) were used as substrates for microbial recovery and identification. Results revealed none of the target pathogenic bacterial species in the honeybee samples, with bacilli, staphylococci, and micrococci dominating their surveyed microbiota. However, most of the suspect colonies isolated from wasps and hornets belonged to important hygienic indicators (i.e., enterococci, Proteus mirabilis, and coliforms), implying possible contact of these insects with fecal origin materials. To sum up, the microbiota that may be transmitted to humans through stinging appears to differ between honeybees and wasps/hornets, while the isolation from the latter samples of some other important opportunistic pathogens, such as Enterobacter spp. and Klebsiella spp., also known for multidrug resistance, could be an additional reason of concern.

Determination of the inhibitory activity of silver nanoparticles against some pathogenic multi-antibiotic resistant bacterial species

The study was done to determine the inhibitory effect of silver nanoparticles synthesed by the filamentous fungus Fusarium mangiferae against some multidrugs resistant pathogenic bacteria which were taken from the Central Laboratory of Sulaymaniyah Teaching Hospital.Silver nanoparticles showed their inhibitory effect on the various bacterial species in this study by two methods Wich are the well diffusion method and inhibition growth. Nanoparticles of silver showed inhibitory areas by Well diffusion method against Staphylococcus aureus, Staphylococcus epidermidis, Pseudomonas aeruginosa, and Proteus mirabilis.&#x0D; The Diameter of inhibition zones of the above mentioned bacteria were (15.25, 20.5, 17.75.16) mm while The method of inhibition of growth had shown that nanoparticles effective against the above bacterial species at concentrations (50, 50, 50, 100)% respectively through the lack of growth of the colonies on the surface of the nutrient agar. Therefore, the use of nanoparticles from some metals is the best solution for the treatment of infectious diseases due to the effective inhibiting properties of these nanoparticles against bacteria without negative side effects.

MBPD: A multiple bacterial pathogen detection pipeline for One Health practices.

Bacterial pathogens are one of the major threats to biosafety and environmental health, and advanced assessment is a prerequisite to combating bacterial pathogens. Currently, 16S rRNA gene sequencing is efficient in the open-view detection of bacterial pathogens. However, the taxonomic resolution and applicability of this method are limited by the domain-specific pathogen database, taxonomic profiling method, and sequencing target of 16S variable regions. Here, we present a pipeline of multiple bacterial pathogen detection (MBPD) to identify the animal, plant, and zoonotic pathogens. MBPD is based on a large, curated database of the full-length 16S genes of 1986 reported bacterial pathogen species covering 72,685 sequences. In silico comparison allowed MBPD to provide the appropriate similarity threshold for both full-length and variable-region sequencing platforms, while the subregion of V3-V4 (mean: 88.37%, accuracy rate compared to V1-V9) outperformed other variable regions in pathogen identification compared to full-length sequencing. Benchmarking on real data sets suggested the superiority of MBPD in a broader range of pathogen detections compared with other methods, including 16SPIP and MIP. Beyond detecting the known causal agent of animal, human, and plant diseases, MBPD is capable of identifying cocontaminating pathogens from biological and environmental samples. Overall, we provide a MBPDpipeline for agricultural, veterinary, medical, and environmental monitoring to achieve One Health.

Isolation and Identification of some Species of Bacterial Pathogens from Musca Domestic and Test their Susceptibility Againts Antibiotics

The current study was conducted during the period from the beginningof October 2016 to April 2017 to isolate and diagnose the bacteria on theouter surface of the domestic fly (Musca domestica) and to determine thesensitivity of bacterial isolates against antibiotics using differentagricultural mediums. Insects were collected from three sites in the Tikritcity which are: vegetable market, butchers market and sheep sheds. 50samples were collected from each site. Bacterial isolates obtained fromthe external surface of insects were subjected to morphological andbiochemical tests and API 20 E system was used for diagnosis.153 isolations were obtained belonging to 9 bacterial species .Escherichia coli reached 36 isolations that prevailed the rest of thebacterial species with an isolation rate of 23.5%, followed by Salmonellatyphi 32 isolates by 20.9% , and Proteus mirabilis 31 isolates by 20.3% .Staphylococcus aureus has 25 isolations by 16.3%. Klebsiella pneumoniahas 11 isolations by 7.2% , and Shigella spp has 7 isolates by 4.6%,followed by Citrobacter freundii which has 6 isolates by 3.9% , ThenHafina spp. Has 3 isolations by 1.9% , Serratia marcescens has only twoisolates by 1.3% .The results showed that the highest contamination rate was in thevegetable market which is 92%, then the sheep sheds is 88%, and finallyButchers market is 86%.The Gram-negative bacterial isolates were tested for sensitivity to 8 typesof antibiotics, E.coli showed the highest resistance to both Erythromycinand Ceftriaxon by 77.8% , while S.typhi showed resistance to Amikacinand Ceftriaxon by 53.1%, P.mirabilis was resistant to Tetracyclin by64.5%, Shigella spp. was resistant to Ceftriaxon by 57.14%,K.Pneumonia bacteria were resistant to Erythromycin by 72.7% ,C.freundii showed resistance to the antibiotic Trimethoprim +Sulfamethoxazol and 100%, Hafnia was 33.33% resistant toChloramphenicol, Finally, Ser.marcescens were 100% resistant toErythromycin.The sensitivity of Staph.aureus bacteria was tested against 5 types ofantibiotics with the highest resistance to Vancomycin by 80% .

Study the inhibitory effect of Genger and Altbek grain against the growth some pathogenic bacterial and fungal species

This study included the test of Antimicrobial activity for two types extracts, the first is effect of aqueous, alcoholic, fresh juice and powder ginger extract .The second is the aqueous and alcoholic extract of Altbek grain on sex bacterial species: Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pneumonia, Proteus mirabilis, Escherichia coli, Klebsiella pneumonia and 3 fungal species belonging to the genus Candida: Candida albicans, Candida krusei, Candida glabrata . The results showed that both the aqueous and alcoholic for genger have high inhibited activity against p.mirabilis comparison all five tested antibiotics ,Also have the aqueous extract of ginger high activity against K .pneumonia when compared to all Antibiotics used in the study, either powder extract of genger have high inhibited activity against only P.aeruginosa while not showed any effective inhibition against bacterial and fungal species, also showed effective inhibition for alcoholic extract of genger against all fungal species, While not showed any effective inhibition for aqueous, juice and powder extract against fungal species. The study showed the aqueous and alcoholic Altbek grain have high effective activity against S.aureus comparison to Antibiotics: Cefotaxim, Norfloxacin and moderate effective when compared to Antibiotics: Amikacin, Ciprofloxacin, Augmentin, The aqueous and alcoholic genger extract have highly effective inhibition against S.pneumonia compared of Antibiotics: Norfloxacin, Augmentin, Cefotaxim and medium effective compared with Antibiotics: Amikacin, Ciprofloxacin, and did not appear any effective inhibition against all fungal species.

Proteome-Wide Screening of Potential Vaccine Targets against Brucella melitensis.

The ongoing antibiotic-resistance crisis is becoming a global problem affecting public health. Urgent efforts are required to design novel therapeutics against pathogenic bacterial species. Brucella melitensis is an etiological agent of brucellosis, which mostly affects sheep and goats but several cases have also been reported in cattle, water buffalo, yaks and dogs. Infected animals also represent the major source of infection for humans. Development of safer and effective vaccines for brucellosis remains a priority to support disease control and eradication in animals and to prevent infection to humans. In this research study, we designed an in-silico multi-epitopes vaccine for B. melitensis using computational approaches. The pathogen core proteome was screened for good vaccine candidates using subtractive proteomics, reverse vaccinology and immunoinformatic tools. In total, 10 proteins: catalase; siderophore ABC transporter substrate-binding protein; pyridoxamine 5'-phosphate oxidase; superoxide dismutase; peptidylprolyl isomerase; superoxide dismutase family protein; septation protein A; hypothetical protein; binding-protein-dependent transport systems inner membrane component; and 4-hydroxy-2-oxoheptanedioate aldolase were selected for epitopes prediction. To induce cellular and antibody base immune responses, the vaccine must comprise both B and T-cells epitopes. The epitopes were next screened for antigenicity, allergic nature and water solubility and the probable antigenic, non-allergic, water-soluble and non-toxic nine epitopes were shortlisted for multi-epitopes vaccine construction. The designed vaccine construct comprises 274 amino acid long sequences having a molecular weight of 28.14 kDa and instability index of 27.62. The vaccine construct was further assessed for binding efficacy with immune cell receptors. Docking results revealed that the designed vaccine had good binding potency with selected immune cell receptors. Furthermore, vaccine-MHC-I, vaccine-MHC-II and vaccine-TLR-4 complexes were opted based on a least-binding energy score of -5.48 kcal/mol, 0.64 kcal/mol and -2.69 kcal/mol. Those selected were then energy refined and subjected to simulation studies to understand dynamic movements of the docked complexes. The docking results were further validated through MMPBSA and MMGBSA analyses. The MMPBSA calculated -235.18 kcal/mol, -206.79 kcal/mol, and -215.73 kcal/mol net binding free energy, while MMGBSA estimated -259.48 kcal/mol, -206.79 kcal/mol and -215.73 kcal/mol for TLR-4, MHC-I and MHC-II complexes, respectively. These findings were validated by water-swap and entropy calculations. Overall, the designed vaccine construct can evoke proper immune responses and the construct could be helpful for experimental researchers in formulation of a protective vaccine against the targeted pathogen for both animal and human use.

CIM monolithic chromatography as a useful tool for endotoxin reduction and purification of bacteriophage particles supported with PAT analytics

Bacteriophages represent immense potential as therapeutic agents. Many of the most compelling applications of bacteriophages involve human therapy, some pertinent to gene therapy, others involving antibiotic replacement. Phages themselves are considered safe for humans. However, phage lysates may contain many kinds of harmful by-products, especially endotoxins of gram-negative bacteria and protein toxins produced by many pathogenic bacterial species. In bacteriophage research and therapy, most applications ask for highly purified phage suspensions, as such it is crucial to reduce proteins, endotoxins, DNA and other contaminants.In this article we present an efficient two-step chromatographic purification method for P. aeruginosa bacteriophage PP-01, using Convective Interaction Media (CIM®) monoliths, that is cGMP compliant and easy to scale-up for most stringent production of the therapeutic phage. First chromatographic step on CIMmultus OH resulted in 100% bacteriophage recovery with a reduction of 98 % protein and more than 99 % DNA content. Polishing was conducted using three different column options, CIMmultus with QA, H-Bond and PrimaS ligands. For PP-01 bacteriophage all three different options worked, but multimodal ligands H-Bond and PrimaS outperformed traditional QA in endotoxin removal (7 log step reduction). Additionally, an HPLC analytical method was developed to estimate phage concentration and impurity profile in different in-process samples. The HPLC method shows good correlation with drop assay titration, provides useful insights and can be run very fast with just 20 min per sample analysis.

Structural elucidation of new ferrocene appended scaffold and their metal complexes: Comparative in vitro DNA/BSA binding and antibacterial assay

A new organometallic ligand (L) was designed and synthesized from ferrocenecarboxaldehyde and 2–Aminobenzophenone through the condensation reaction in one step process. The metal complexes of this L with the formula [Zn(L)2](NO3)2 (1), [Cu(L)2](NO3)2 (2) and [Co(L)2](NO3)2 (3) were synthesized in high yield. The ligand (L) and complexes 1–3 were completely characterized by elemental analysis, spectroscopic and spectrometric techniques such as FT–IR, ToF Mass,1H NMR,13C NMR molar conductance and magnetic moment measurements. The spectroscopic interpretation showed that complex 1 and complex 3 prefer tetrahedral geometry whereas complex 2 adopts a square planar arrangement around the copper(II) ion. The in vitro DNA interaction studies of ligand (L) and metal complexes 1–3, were performed by UV–Vis absorption, fluorescence spectral and ethidium bromide displacement experiments. The absorption studies of complexes 1–3 reveal the existence of both hyperchromic and hypochromic effect which indicated the mixed type of binding that is intercalation of the aromatic part and the electrostatic surface interaction of metal ions with DNA phosphate groups. A comparison of binding constant Kb values suggested the stronger binding of complex 2 (Kb = 6.17 × 104 M−1) as compared to L and complexes 1 and 3. Furthermore, in vitro BSA binding studies and FRET also suggests greater interaction of complex 2 with BSA causing modulations in the hydrophobic microenvironment near Trp-212 in the subdomain IIA pocket by static quenching mechanism. Interestingly, all three complexes 1–3 tested showed promising antimicrobial activity as revealed by the disc diffusion assay in all four human pathogenic bacterial species comprising both gram–positive and gram–negative bacteria.

An investigation of Baccharoides anthelmintica (L.) Moench seed extract for antibacterial and antioxidant activities

Use of herbal remedies is on the rise in developed and developing countries. Plant kingdom is a gold mine for novel and affordable antimicrobial and antioxidant compounds. The medicinal properties of plants are due to metabolites especially secondary compounds produced by plant species around the globe. The current study was designed to investigate the seed extract of Baccharoides anthelmintica (L.) Moench for its antibacterial and antioxidant activities. The antibacterial activity of the acetone, aqueous and methanol seed extracts was determined in-vitro against medically important pathogens such as Bacillus cereus, Escherichia coli, Listeria monocytogenes, Pseudomonas aeruginosa, Staphylococcus aureus and Yersinia pestis by agar-well diffusion method using different concentrations (25, 50, 75 and 100%). Results showed low to significant antibacterial activity against the mentioned pathogenic bacterial species. The methanol extract of B. anthelmintica showed maximum zone of inhibition (20.40±0.68 mm) in the growth of L. monocytogenes which was followed by P. aeruginosa (19.10±1.77 mm), S. aureus (18.55±2.20 mm), E. coli (16.00±0.60 mm) and Y. pestis (16.00±0.00 mm) at 100% of its concentration respectively. Methanol seed extract was found to be more effective against selected pathogenic bacterial species as compared to acetone and aqueous seed extracts. Further the seed extract inhibited gram-positive bacteria more efficiently than gram-negative bacteria. The antioxidant capacity of the different seed extracts (methanol, acetone and aqueous) of B. anthelmintica was evaluated by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging assay at different concentrations (20, 40, 60, 80 and 100 µg/mL). The plant showed 14.40±0.05 and 13.20±0.55 % DPPH radical scavenging potential in methanol and acetone extracts respectively at 100 µg/mL and exhibited no radical scavenging potential in case of aqueous extract. Therefore, the seed extracts of this plant can be selected for further investigation to discover or determine their ultimate therapeutic potential.&#x0D; Keywords: Baccharoides anthelmintica, seed extract, agar well diffusion, zone of inhibition, DPPH

Comparison of Microbial Composition of Natural Teeth and Implants by 16S rRNA Gene Sequencing.

Exploring variations in the oral microbiome that predict the early stages of oral diseases could lead to more accurate diagnosis and therapy before the disease manifests clinically. This study compared the bacterial profile around prosthesis on natural teeth and implants in a healthy oral cavity. Fifteen participants with prosthesis on natural teeth and 15 participants with implants were recruited. All participants were periodontally healthy. Plaque samples were collected and then subjected to PCR amplification with 16S rRNA gene sequencing. Using the BlastN program, the sequenced data were compared to reference bacterial gene sequences in the Human Oral Microbiome Database. Finally, bacterial species in both groups' samples were identified, and a phylogenetic tree was created to compare the bacterial profile around prosthesis on natural teeth and implants. Microorganisms identified were Streptococcus, Fusobacterium, Corynebacterium, Micrococcus, Aeromonas, Leptotrichia, and Dechloromonas species; around implants were Streptococcus, Fusobacterium, Corynebacterium, Prevotella, Eikenella, Nisseria, Rothia, Aeromonas, Leptotrichia, and Actinomyces species. On comparing the bacterial profile around prosthesis on natural teeth and implants in periodontally healthy individuals, pathogenic bacterial species including Fusobacterium nucleatum, Prevotella intermedia, and Eikenella corrodens were identified around implants.

Choline and geranic acid (CAGE)ionic liquids inhibit both elastase activity and growth of oral bacteria.

Choline and geranic acid (CAGE) ionic liquids have recently been shown to have applications in the delivery of macromolecules and poorly soluble drugs across epithelial barriers and in bacterial growth inhibition. Ionic liquids are known to denature proteins by the disruption of forces that guide natural protein folding, and the inflammatory enzyme elastase was recently shown to be inhibited by a variety of ionic liquids other than CAGE. Inhibition of collagenolytic enzymes, including elastase, has been shown to improve outcomes in cases of periodontitis via amelioration of periodontal inflammation and alveolar bone resorption. In this study, we investigated whether CAGE prepared with varying stoichiometries was able to inhibit elastase at varying concentrations and whether these CAGE formulations could inhibit the growth of key pathogenic bacterial species associated with oral health conditions. We found that CAGE was capable of inhibiting both porcine elastase and human neutrophil elastase at concentrations as low as 5 mM, and that CAGE formulations were effective at inhibiting the growth of all tested pathogenic oral bacteria. The inhibition of elastase by CAGE may be a mechanism by which CAGE can improve outcomes in periodontitis independent from CAGE's known antibacterial properties.

Proteomic Profiling Reveals Distinct Bacterial Extracellular Vesicle Subpopulations with Possibly Unique Functionality.

Bacterial outer membrane vesicles (OMVs) are 20- to 200-nm secreted packages of lipids, small molecules, and proteins that contribute to diverse bacterial processes. In plant systems, OMVs from pathogenic and beneficial strains elicit plant immune responses that inhibit seedling growth and protect against future pathogen challenge. Previous studies of OMV-plant interactions suggest functionally important differences in the protein composition of Pseudomonas syringae and Pseudomonas fluorescens OMVs, and that their composition and activity differ as a result of medium culture conditions. Here, we show that plant apoplast-mimicking minimal medium conditions impact OMV protein content dramatically in P. syringae but not in P. fluorescens relative to complete medium conditions. Comparative, 2-way analysis of the four conditions reveals subsets of proteins that may contribute to OMV-mediated bacterial virulence and plant immune activation as well as those involved in bacterial stress tolerance or adaptation to a beneficial relationship with plants. Additional localization enrichment analysis of these subsets suggests the presence of outer-inner membrane vesicles (OIMVs). Collectively, these results reveal distinct differences in bacterial extracellular vesicle cargo and biogenesis routes from pathogenic and beneficial plant bacteria in different medium conditions and point to distinct populations of vesicles with diverse functional roles. IMPORTANCE Recent publications have shown that bacterial vesicles play important roles in interkingdom communication between bacteria and plants. Indeed, our recently published data reveal that bacterial vesicles from pathogenic and beneficial strains elicit immune responses in plants that protect against future pathogen challenge. However, the molecules underlying these striking phenomena remain unknown. Our recent work indicated that proteins packaged in vesicles are critically important for vesicle-mediated seedling growth inhibition, often considered an indirect measure of plant immune activation. In this study, we characterize the protein cargo of vesicles from Pseudomonas syringae pathovar tomato DC3000 and Pseudomonas fluorescens from two different medium conditions and show that distinct subpopulations of vesicles contribute to bacterial virulence and stress tolerance. Furthermore, we reveal differences in how beneficial and pathogenic bacterial species respond to harsh environmental conditions through vesicle packaging. Importantly, we find that protein cargo implicates outer-inner membrane vesicles in bacterial stress responses, while outer membrane vesicles are packaged for virulence.

Study on the anti-microbial effect of Sinigrin against some pathogenic bacterial species

The increasing anti-bacterial drug resistance is one of the biggest challenges facing doctors around the globe, so finding alternative treatments is one of the ideal options to overcome this problem. The cruciferous family is one of the wealthiest plants worldwide because it contains the most important secondary metabolites, glucosinolates, known for their anti-microbial properties. The present study aimed to evaluate the anti-bacterial effect of glucosinolates (Sinigrin) against eight bacterial isolates (Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Actinomyces, Proteus mirabilis and Streptococcus pneumoniae). The current study investigated six concentrations of pure Sinigrin (100, 300, 500, 700, 900, and 1100 µg/ml). The sensitivity of bacterial isolates to various antibiotics was tested by VITIK 2DensiCheck equipment. The anti-bacterial activity of Sinigrin was assessed using the agar diffusion method, and the microtiter plate method measured the minimal inhibitory concentration (MIC). The highest anti-bacterial effect of Sinigrin was observed against S. aureus, E. coli, and E. faecalis. The anti-bacterial activity started as lower as 100 µg/ml, while a moderate effect was seen against P. aeruginosa and K. pneumoniae at a concentration lower than 700 µg/ml. On the other hand, Sinigrin was not effective against Actinomyces, P. mirabilis, and S. pneumoniae. It can be concluded from the present study that Sinigrin has an anti-bacterial effect on some isolates of bacteria which suggests the possibility of using Sinigrin as alternative medicine in the future. Keywords: Anti-bacterial activity, Agar well diffusion, Glucosinolates, Minimum inhibition concentration and antibiotic susceptibility, Sinigrin.