Silicon nanoparticles: A promising approach for control of Pseudomonas aeruginosa biofilms.

Objectives: The current study aimed to investigate the control and treatment of biofilm-producing isolates of Pseudomonas aeruginosa using silicon nanoparticles (SiNPs). Materials and Methods: Biofilm-producing isolates of P. aeruginosa were recovered from various food samples and identified through fluorescent green colony formation on selective and differential media, as well as the amplification of oprI and oprL genes. Tube methods, Congo-red agar method, and scanning electron microscopy (SEM) were used to study biofilm phenotypes. The effect of SiNPs was evaluated by broth dilution assay. Results: The biofilm assay revealed that these isolates formed biofilms on glass surfaces within 72 hr of incubation. Scanning electron micrographs showed that the biofilm communities were composed of multicellular clusters of P. aeruginosa encased in matrix material. However, these isolates were unable to form biofilms on SiNPs-coated surfaces. The results showed that the planktonic isolates of P. aeruginosa were comparatively sensitive to the antibacterial properties of SiNPs, with minimum inhibitory concentration (MIC) ranging from 100 to 200 µg/ml. Contrarily, the biofilms were found to be 500 times more tolerant to the highest concentration of SiNPs (MIC of 500 µg/ml) and were more resistant. Under static conditions, the sedimentation of SiNPs resulted in their ineffectiveness. However, under shaking conditions, the biofilms were effectively dispersed and the cells were lysed. The results showed that SiNPs were effective against both the planktonic and the metabolically inactive forms of P. aeruginosa. Conclusion: This study suggests that SiNPs could be a useful tool for preventing the formation of biofilms and removing pre-existing biofilms.

Nanotubes Formation in P. aeruginosa.

The present study discusses a biofilm-positive P. aeruginosa isolate that survives at pH levels ranging from 4.0 to 9.0. The biofilm consortia were colonized with different phenotypes i.e., planktonic, slow-growing and metabolically inactive small colony variants (SCVs). The lower base of the consortia was occupied by SCVs. These cells were strongly attached to solid surfaces and interconnected through a network of nanotubes. Nanotubes were observed at the stationary phase of biofilm indwellers and were more prominent after applying weight to the consortia. The scanning electron micrographs indicated that the nanotubes are polar appendages with intraspecies connectivity. The micrographs indicated variations in physical dimensions (length, width, and height) and a considerable reduction in volume due to weight pressure. A total of 35 cells were randomly selected. The mean volume of cells before the application of weight was 0.288 µm3, which was reduced to 0.144 µm3 after the application of weight. It was observed that a single cell may produce as many as six nanotubes, connected simultaneously to six neighbouring cells in different directions. The in-depth analysis confirmed that these structures were the intra-species connecting tools as no free nanotubes were found. Furthermore, after the application of weight, cells incapable of producing nanotubes were wiped out and the surface was covered by nanotube producers. This suggests that the nanotubes give a selective advantage to the cells to resist harsh environmental conditions and weight pressure. After the removal of weight and proper supply of nutrients, these phenotypes reverted to normal planktonic lifestyles. It is concluded that the nanotubes are not merely the phenomenon of dying cells; rather they are a connectivity tool which helps connected cells to tolerate and resist environmental stress.

An effective weapon against biofilm consortia and small colony variants of MRSA.

OBJECTIVES: This study was designed to investigate the effect of AgNPs (10 nm and 30 nm) on different phenotypes of Staphylococcus aureus biofilm consortia. MATERIALS AND METHODS: A total of eighteen biofilm-producing isolates of Methicillin-Resistant S. aureus (MRSA) were used in the present study. Tube methods, Congo-red agar method, and scanning electron microscopy (SEM) were used to study biofilm phenotypes. Population analysis assay on a tryptone soya agar (TSA) plate was applied to study the different phenotypes of biofilm consortia. The effect of AgNPs was evaluated by broth dilution assay. RESULTS: Results showed that biofilm consortia harbour different phenotypes, i.e., planktonic, metabolically inactive cells, and small colony variants (SCVs) or persister cells. The focus of the present study is the effect of AgNPs on biofilm consortia of MRSA, particularly on the SCVs population. Large size AgNPs (30 nm) were unable to diffuse through extracellular matrix material coverings of the biofilm consortia; they were only active against the planktonic population that occupies the outer surface of consortia. The smaller AgNPs (10 nm), on the other hand, were found to diffuse through the matrix material and hence were effective against planktonic as well as metabolically inactive population of consortia. Moreover, 30 nm AgNPs take 6 hr to disperse off and kill planktonic and upper surface indwellers. The 10 nm AgNPs disperse and kill the majority of biofilm indwellers within 20 min. CONCLUSION: The present study showed that 10 nm AgNPs can easily penetrate inside the biofilm and are active against all of the indwellers of consortia.

Relationship of cell surface hydrophobicity with biofilm formation and growth rate: A study on Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli.

OBJECTIVES: This study was designed to determine the relationship of Pseudomonas aeruginosa, Staphylococcus aureus, and Escherichia coli isolates in multispecies biofilms and their individual phenotypic characters in biofilm consortia. MATERIALS AND METHODS: The subject isolates were recovered from different food samples and identified on the basis of growth on differential and selective media. Tube methods, Congo-red agar method, and scanning electron microscopy (SEM) were used to study biofilms phenotypes. The hydrophobicity of the strains was evaluated by the adhesion to apolar solvent. RESULTS: The results showed that E. coli dominated the pre-biofilm stage. It has been observed that E. coli adopted biofilm life much before S. aureus and P. aeruginosa. However, after adopting biofilm lifestyle, slowly and gradually, P. aeruginosa dominated the consortia and dispersed other stakeholders. The subject isolates of P. aeruginosa produce cis-2-decanoic acid to disperse or inhibit S. aureus and E. coli biofilms. Gas-chromatography and mass spectrometry results showed that cis-2-decanoic was higher in the co-culture condition and increased at late log-phase or at stationary phase. Although majority of S. aureus were unable to compete with P. aeruginosa, however, a minor population competed, survived, and persisted in biofilm consortia as small colony variants. The survivors showed higher expression of sigB and sarA genes. P. aeruginosa showed comparatively higher hydrophobic surface properties. CONCLUSION: Comparative analysis showed that cell surface hydrophobicity, growth rate, and small colony variants (SCVs) are correlated in biofilm consortia of the P. aeruginosa, S. aureus, and E. coli.

Evaluation of a classical unani pharmacopeial formulation safoof-e-muhazzil in hyperlipidemia: A randomized, standard controlled clinical study.

AIM OF THE STUDY: The aim of the following study is to evaluate the efficacy and tolerability of a compound Unani formulation in hyperlipidemia on clinical and biochemical parameters. MATERIALS AND METHODS: A total of 90 patients with total cholesterol level of 220 mg/dl and above were included. In Group 'A' thirty patients with total cholesterol 243.5 ± 5.294 mg/dl received Unani formulation safoof-e-muhazzil (SM) in its classical powder form 5 g twice daily orally, in Group 'B' thirty patients with total cholesterol 234 ± 3.822 mg/dl received the SM but in compressed tablet form in the same dosage and in Group 'C' 30 patients with total cholesterol 242.7 ± 5.563 mg/dl received atorvastatin 10 mg as a standard control. Follow-up was carried out on second, fourth and 6th week and patients were evaluated on clinical as well as biochemical parameters. RESULTS: Group A before treatment had mean total cholesterol of 243.5 ± 5.294 mg/dl which decreased significantly after treatment to 225.6 ± 5.953 mg/dl (P < 0.001) with a percentage change of 7.35%. Group B had mean total cholesterol of 234 ± 3.822 mg/dl which was significantly reduced to 212.67 ± 3.94 mg/dl (P < 0.001) post-treatment with a percentage change of 9.11%. Control Group C having mean total cholesterol of 242.7 ± 5.563 mg/dl before treatment was significantly decreased to 178.73 ± 4.669 mg/dl (P < 0.001) post-treatment with a percentage change of 26.3%. Group A had significant relief 20.72% (P < 0.001) in fatigue, 16.09% (P > 0.5) relief in palpitation and 26.17% (P < 0.001) relief in dyspnea post-treatment. Group B fatigue decreased significantly by 18.14% (P < 0.01), palpitation by 22.91% (P < 0.01) and dyspnea by 20.46% (P < 0.01). In Group C a non-significant increase of 2.2% was observed in fatigue post-treatment, palpitation decreased by 10.22% non-significantly and dyspnea decreased significantly by 17.64% (P < 0.001). Results indicate that the test drug safely and effectively ameliorates the clinical condition of patients with hyperlipidemia while decreasing cholesterol level as well.

Efficacy of a classical antiobesity Unani pharmacopial formulation (Safoof-e-Muhazzil) in systolic and diastolic blood pressure: A randomized, open-labeled, controlled clinical study.

The aim of this study is to evaluate the efficacy of a Unani formulation in hypertension. A total of 90 patients with total cholesterol level of more than 220 mg/dl with associated conditions were included in this study. A total of 30 patients having a mean systolic blood pressure (BP) of 133.86 mmHg comprising Group A received Unani formulation Safoof-e-Muhazzil (SM) in its classical powder form in the dose of 5 g twice a day orally. Group B comprising of 30 patients with a mean systolic BP of 133.13 mmHg received same drug, but in compressed tablet form in the same dosage, whereas, 30 patients comprising Group C with a mean systolic BP of 129.45 mmHg, received Atorvastatin 10 mg as a standard control. Patients were evaluated on each follow-up at 2(nd), 4(th) and 6(th) week. The mean systolic BP in Group A and B before treatment was 133.86 ± 3.028 mmHg and 133.13 ± 2.852 mmHg, which significantly decreased to 119.33 ± 1.922 mmHg (P < 0.001) and 119 ± 1.760 mmHg (P < 0.001) respectively. In the control Group C before treatment BP was 129.45 ± 2.499 mmHg and after treatment it significantly decreased to 124.34 ± 1.794 mmHg (P < 0.01). The percentage change after treatment was 10.85%, 10.61% and 3.94% respectively in each group. Mean diastolic BP in Group A and B before treatment was 85.06 ± 2.11 mmHg and 84.56 ± 1.5 mmHg, which significantly decreased to 79.06 ± 1.56 mmHg (P < 0.001) and 79.96 ± 1.15 mmHg (P < 0.001) respectively, BP before treatment in Group C was 83.23 ± 1.588 mmHg, which was decreased to 124.34 ± 1.794 mmHg (P < 0.01). The study results indicate that the test drug was quite effective in reducing both systolic as well as diastolic BP.

Management of knee osteoarthritis with cupping therapy.

The study aimed to evaluate the effect of cupping therapy at a clinical setting for knee osteoarthritis. A randomized, controlled clinical trial was conducted. Cupping was performed on 0-6(th) day; 9-11(th) day and 14(th) day, i.e., 11 sittings follow-up to determine longer term carryover of treatment effects utilizing both objective and subjective assessment. The assessment was performed before and after treatment spreading over a period of 15 days. The results of this study shows significant and better results in the overall management of knee osteoarthritis, particularly in relieving pain, edema, stiffness and disability. The efficacy of treatment with cupping therapy in relieving signs and symptoms of knee osteoarthritis is comparable to that of acetaminophen 650 mg thrice a day orally, in terms of analgesia, anti-inflammatory and resolution of edema with minimal and temporary side-effects like echymosis and blister formation while as control drug has greater side-effects particularly on upper gastrointestinal tract. It is recommended that further studies are conducted with a larger study samples and of longer duration.