Oral bacteriophages: metagenomic clues to interpret microbiomes

Bacteriophages are bacterial viruses that are distributed throughout the environment. Lytic phages and prophages in saliva, oral mucosa, and dental plaque interact with the oral microbiota and can change biofilm formation. The interactions between phages and bacteria can be considered a portion of oral metagenomics. The metagenomic profile of the oral microbiome indicates various bacteria. Indeed, there are various phages against these bacteria in the oral cavity. However, some other phages, like phages against Absconditabacteria, Chlamydiae, or Chloroflexi, have not been identified in the oral cavity. This review gives an overview of oral bacteriophage and used for metagenomics. Metagenomics of these phages deals with multi-drug-resistant bacterial plaques (biofilms) in oral cavities and oral infection. Hence, dentists and pharmacologists should know this metagenomic profile to cope with predental and dental infectious diseases

Combinatorial effects of antibiotics and enzymes against dual-species Staphylococcus aureus and Pseudomonas aeruginosa biofilms in the wound-like medium.

Bacterial biofilms are one of the major issues in the treatment of chronic infections such as chronic wounds, where biofilms are typically polymicrobial. The synergy between species can occur during most polymicrobial infections, where antimicrobial resistance enhances as a result. Furthermore, self-produced extracellular polymeric substance (EPS) in biofilms results in a high tolerance to antibiotics that complicates wound healing. Since most antibiotics fail to remove biofilms in chronic infections, new therapeutic modalities may be required. Disruption of EPS is one of the effective approaches for biofilm eradication. Therefore, degradation of EPS using enzymes may result in improved chronic wounds healing. In the current study, we investigated the efficacy of trypsin, β-glucosidase, and DNase I enzymes on the degradation of dual-species biofilms of Pseudomonas aeruginosa and Staphylococcus aureus in a wound-like medium. These species are the two most common bacteria associated with biofilm formation in chronic wounds. Moreover, the reduction of minimum biofilm eradication concentration (MBEC) of meropenem and amikacin was evaluated when combined with enzymes. The minimum effective concentrations of trypsin, β-glucosidase, and DNase I enzymes to degrade biofilms were 1 μg/ml, 8 U/ml, and 150 U/ml, respectively. Combination of 0.15 μg/ml trypsin and 50 U/ml DNase I had a significant effect on S. aureus-P. aeruginosa biofilms which resulted in the dispersal and dissolution of all biofilms. In the presence of the enzymatic mixture, MBECs of antibiotics showed a significant decrease (p < 0.05), at least 2.5 fold. We found that trypsin/DNase I mixture can be used as an anti-biofilm agent against dual-species biofilms of S. aureus-P. aeruginosa

Evaluation of Mannosidase and Trypsin Enzymes Effects on Biofilm Production of Pseudomonas aeruginosa Isolated from Burn Wound Infections.

Biofilm is an important virulence factor in Pseudomonas aeruginosa and has a substantial role in antibiotic resistance and chronic burn wound infections. New therapeutic agents against P. aeruginosa, degrading biofilms in burn wounds and improving the efficacy of current antimicrobial agents, are required. In this study, the effects of α-mannosidase, β-mannosidase and trypsin enzymes on the degradation of P. aeruginosa biofilms and on the reduction of ceftazidime minimum biofilm eliminating concentrations (MBEC) were evaluated. All tested enzymes, destroyed the biofilms and reduced the ceftazidime MBECs. However, only trypsin had no cytotoxic effect on A-431 human epidermoid carcinoma cell lines. In conclusion, since trypsin had better features than mannosidase enzymes, it can be a promising agent in combatting P. aeruginosa burn wound infections

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

Abstract INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02&#956;L/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance

Identification of Etiologic Agents of the Pertussis-like Syndrome in Children by Real-time PCR Method

The aim of this study was to recognize the identity and frequency of etiologic agents of the pertussis-like syndrome in children 6 months of age. In this study, RSV was the most frequent identified pathogen (n=20, 20%), followed by B. pertussis (n=18, 18%) and AdV (n=16, 16%). Pertussis was more frequent in spring (8%) and summer (6%). In addition, clinical symptoms of pertussis were the same as some viral pathogens, which can lead to misdiagnosis of infection. Therefore, diagnosis of pertussis should be established on the bases of both the clinical symptoms and the laboratory methods

Monoterpene isolated from the essential oil of Trachyspermum ammi is cytotoxic to multidrug-resistant Pseudomonas aeruginosa and Staphylococcus aureus strains

INTRODUCTION: The aim of this study was to determine whether an herbal extract containing monoterpene exhibited activity against multidrug-resistant Staphylococcus aureus and Pseudomonas aeruginosa isolated from clinical infection samples. METHODS: The essential oil of Trachyspermum ammi (L.) Sprague ex Turrill (Apiaceae) fruit was extracted by hydrodistillation. Fruit residues were treated with hydrochloric acid and re-hydrodistilled to obtain volatile compounds. Compounds in the distilled oil were identified using gas-chromatography (GC) and GC-mass spectrometry (MS). The antibiotic susceptibility of all bacterial isolates was analyzed using both the disc diffusion method and determination of the minimum inhibitory concentration (MIC). The sensitivity of antibiotic-resistant isolates to essential oil was also determined by using the disc diffusion method and MIC determination. RESULTS: Of 26 clinical isolates, 92% were multidrug-resistant (MDR). Aromatic monoterpenes (thymol, paracymene, and gamma-terpinene) were the major (90%) components of the oil. Growth of S. aureus strains was successfully inhibited by the oil, with an inhibitory zone diameter (IZD) between 30-60mm and MIC <0.02μL/mL. The oil had no antimicrobial activity against clinical isolates of P. aeruginosa; rather, it prevented pigment production in these isolates. CONCLUSIONS: This study revealed that the essential oil of Trachyspermum ammi, which contains monoterpene, has good antibacterial potency. Monoterpenes could thus be incorporated into antimicrobial ointment formulas in order to treat highly drug-resistant S. aureus infections. Our findings also underscore the utility of research on natural products in order to combat bacterial multidrug resistance

Evaluation of Mannosidase and Trypsin Enzymes Effects on Biofilm Production of Pseudomonas aeruginosa Isolated from Burn Wound Infections

Biofilm is an important virulence factor in Pseudomonas aeruginosa and has a substantial role in antibiotic resistance and chronic burn wound infections. New therapeutic agents against P. aeruginosa, degrading biofilms in burn wounds and improving the efficacy of current antimicrobial agents, are required. In this study, the effects of α-mannosidase, β-mannosidase and trypsin enzymes on the degradation of P. aeruginosa biofilms and on the reduction of ceftazidime minimum biofilm eliminating concentrations (MBEC) were evaluated. All tested enzymes, destroyed the biofilms and reduced the ceftazidime MBECs. However, only trypsin had no cytotoxic effect on A-431 human epidermoid carcinoma cell lines. In conclusion, since trypsin had better features than mannosidase enzymes, it can be a promising agent in combatting P. aeruginosa burn wound infections

The efficacy of lyticase and β-glucosidase enzymes on biofilm degradation of Pseudomonas aeruginosa strains with different gene profiles

Background: Pseudomonas aeruginosa is a nosocomial pathogen that causes severe infections in immunocompromised patients. Biofilm plays a significant role in the resistance of this bacterium and complicates the treatment of its infections. In this study, the effect of lyticase and β-glucosidase enzymes on the degradation of biofilms of P. aeruginosa strains isolated from cystic fibrosis and burn wound infections were assessed. Moreover, the decrease of ceftazidime minimum biofilm eliminating concentrations (MBEC) after enzymatic treatment was evaluated. Results: This study demonstrated the effectiveness of both enzymes in degrading the biofilms of P. aeruginosa. In contrast to the lyticase enzyme, β-glucosidase reduced the ceftazidime MBECs significantly (P < 0.05). Both enzymes had no cytotoxic effect on the A-549 human lung carcinoma epithelial cell lines and A-431 human epidermoid carcinoma cell lines. Conclusion: Considering the characteristics of the β-glucosidase enzyme, which includes the notable degradation of P. aeruginosa biofilms and a significant decrease in the ceftazidime MBECs and non-toxicity for eukaryotic cells, this enzyme can be a promising therapeutic candidate for degradation of biofilms in burn wound patients, but further studies are needed

Influence of the most effective concentrations of alpha-mannosidase (0.02 unit/ml), beta-mannosidase (0.02 unit/ml), citrate buffer (100mM, pH 4.5) and trypsin (0.75μg/ml) on the viability of A-431 human epidermoid carcinoma cell lines after 24h incubation.

<p>No enzyme column represents control positive of the test. The relative cell viability (%) was computed by this formula: [A]_test/ [A]_control ×100. The experiment was performed 2 times in duplicates. Error bars represent standard errors.</p

The effect of selected concentration of enzymes alpha-mannosidase, beta-mannosidase, and trypsin on the biofilms of <i>P</i>. <i>aeruginosa</i> isolates.

<p>The experiment was performed once in triplicates. Error bars represent standard errors.</p