ANTIFUNGAL ACTIVITY OF CHITOSAN AGAINST Rhizopus stolonifer

These days instead of chemical pesticides, various natural alternatives have been used for the management of post-harvest diseases. This research was carried out to evaluate the antifungal potential of different chitosan concentrations viz., 5, 10, and 15 mg/µl against Rhizopus stolonifer by the agar dilution and well diffusion methods. The evaluation was carried out after seven days of incubation by measuring the inhibition of R. stolonifer mycelial growth. Results of the study revealed that the chitosan had a significant inhibitory effect on mycelial growth and maximum mycelial growth inhibition was reported at the 10 and 15 mg/µl concentrations and these two treatments are not significantly different. Based on these results, the best concentration (15 mg/µl) was further evaluated by the well diffusion technique. The average inhibition zones formed by the higher concentration was 25mm. Results of the study suggested that chitosan can be used for the management of post-harvesting diseases of tomatoes.

ROSUVASTATIN CALCIUM NANOSPONGES IN THE FORMULATION OF EXTENDED RELEASE TABLETS

Cyclodextrin has been recognized as a linker molecule that can link with the various drug substances to produce a nano-porous structure called nanosponges (NS) and increase the dissolution rate of poorly soluble drug substances. This work aimed to load rosuvastatin calcium (RSC) with solubility enhancer’s β-cyclodextrin (β-CD) or polyvinyl alcohol (PVA). β-CD based RSC-NS were fabricated by the emulsion solvent diffusion technique; with solubilizer dichloromethane and different ratios of ethyl cellulose as a co-polymer. Characterization of the prepared nanosponges was done by various testing procedures that confirm its nanosize and particle size and drug release. RSC loading in NS was assessed by DSC, FTIR and SEM. Among all the formulations F5 has 78.23 % entrapment efficiency. 2-3 folds of increased solubility were obtained with RSC-NS. F1-F6 formulations released 76.35 % - 98.69 % of the drug at the end of 30 min. In the preparation of extended-release tablets, NS prepared from F5 formulation was used and the best tablet formulation was selected based on various evaluation tests. All the formulations except S3, S8 followed first-order release kinetics. S1 & S2 drug release mechanism is Higuchi while other formulations are Korsemeyer-Peppas, so the release mechanism for most of the formulations is erosion than diffusion.

Prevalence of MRSA and Antimicrobial Susceptibility Staphylococcus aureus in Clinical Samples in National Capital Region, India

Background: Infections caused by Staphylococci are frequently linked to indwelling medical equipment. These are extremely difficult to treat with antibiotics. In India, the prevalence of Methicillin-Resistant Staphylococcus aureus (MRSA) varies from 30 to 70%, resulting in high mortality, increased economic burden, and high treatment failure in tertiary care hospitals. Rapid and reliable identification of MRSA is critical for infection management and avoiding the needless use of antibiotics. Materials and Methods: This prospective study was carried out in the Department of Microbiology, Santosh Medical College, Ghaziabad, from the 1st of August 2020 to the 31st of January 2021. MRSA isolates were screened and confirmed using standard methods recommended by the Clinical and Laboratory Standards Institute (CLSI). Methicillin resistance, in Staphylococcus aureus strains, was evaluated using oxacillin/cefoxitin. The Kirby-Bauer disc diffusion technique was used to assess the antibiotic susceptibility pattern of all MRSA strains. Results: In this investigation, MRSA was identified in 29.4% of the 384 Staphylococcus aureus strains. When compared to females, men outnumbered females. Cefoxitin detects a greater amount of MRSA than oxacillin. In this investigation, the majority of MRSA was found in pus samples. Conclusion: MRSA prevalence is known to vary depending on geographical region, hospital type, investigated population, and technique of detection used. Given the clinical implications of MRSA infection and its fast transmission capability, MRSA strains must be monitored on a regular basis.

Sensitivity of Propionibacterium acnes towards Commercial Anti-Acne Formulations

Propionibacterium acnes are aerotolerant anaerobic, gram-positive bacilli that form part of normal flora. They produce several pro-inflammatory substances that can trigger an immune response in the host by an influx of inflammatory leukocytes into the strands, causing inflammatory lesions that leave behind scars. Repeated isolation of Propionibacterium acnes may reduce efficacy among the resistant types, clearly explaining Acne lesions' importance. The Counter acne therapies are often the first treatment choice due to the convenience of cost and time over clinical appointments. However, not all of the commercially available anti-acne formulations are supported by clinical studies. The present study was conducted to test the efficacy of selected commercial anti-acne gel formulations. The microscopic observation and biochemical studies conform to the presence of anti-acne activity. A sensitivity test was performed on all the isolates of Propionibacterium acnes by well diffusion technique. The selected over-the-counter anti-acne gel formulations failed to produce any inhibition zone.

Antibiotic Resistant Enterobacteriaceae in Milk Alternatives

The consumption of non-dairy milk is on the rise due to health benefits. Although there is increasing inclination towards milk alternatives (MA), there is limited data on antibiotic resistant bacteria in these substitutes. The aim of this study was to investigate antimicrobial resistance of bacteria isolated from MA. A total of 138 extracts from almonds (n = 63), cashew nuts (n = 36), and soybeans (n = 39) were analyzed for Enterobacteriaceae. The identification of the bacteria was based on biochemical and PCR methods. Antibiotic sensitivity was determined by using the Kirby-Bauer disk diffusion technique. Overall, 31% (43 of 138) of extracts were positive for Enterobacteriaceae. Ten bacterial species were identified, of which Enterobacter cloacae (42.7%) and Enterobacter cancerogenus (35.4%) were the most predominant species (p < 0.05). Antibiotic resistance was exhibited to vancomycin (88.3%), novobiocin (83.8%), erythromycin (81.1%), which was significantly higher (p < 0.05) than in tetracycline (59.5%), cefpodoxime (30.6%), and nalidixic acid (6.3%). There was no resistance displayed to kanamycin and imipenem. ERY-NOV-VAN-TET and ERY-NOV-CEP-VAN-TET were the most common resistant patterns displayed by Enterobacter cloacae. The findings of this study suggest that MAs, though considered healthy, may be a reservoir of multidrug resistant opportunist pathogens.

Novel topical combo-therapeutic formulation integrating honey, neomycin and bacitracin for diabetic wound management

This study evaluated the healing effects of honey as a topical therapy for diabetic ulcers singly and in combination with bacitracin and neomycin (Cicatrin®), formulated as ointments in experimental rats. Antimicrobial evaluation of the test agents against Vancomycin and Oxacillin resistant Staphylococcus aureus (VORSA) and Pseudomonas aeruginosa was done by the cup plate agar-diffusion technique using the Checkerboard method. Subsequently, the optimized combination was formulated into an ointment and administered as single therapy and in combination to hyperglycemic rats made diabetic by subcutaneous injection of alloxan (130 mg/kg) and inflicted with wounds. Administration was done daily on wounds for 21 days while infected wounds had the pus from them evaluated for presence of VORSA and Pseudomonas aeruginosa. The triple combo-therapeutics formulation had improved anti-bacterial activity, in comparison with the individual formulations, with the ratio (1:9) of Cicatrin®: Honey respectively giving the best activity against VORSA. Also, the triple combo-therapeutics exhibited positive wound contraction and size reduction. Furthermore, clinical signs of infection were absent at the end of the follow-up period in the rats administered the combo-therapeutic agents while other groups of rats administered the bland ointment, and the individual agents were infected with either Pseudomonas aeruginosa or VORSA. In addition, the triple combo-therapeutics formulation exhibited good physicochemical stability throughout the treatment duration and beyond (28 days), with insignificant (p > 0.05) changes in pH and spreadability. The triple combination therapeutics formulation showed superior effect to the singly administered agents (honey and Cicatrin®) in the management of diabetic wounds

Determination of the prevalence of blaoxa-like gene and ISAba1 elements among extensiveــdrug resistant (XDR) Acinetobacter boumannii isolates

The capacity of Multiـdrug resistant (MDR) Acinetobacter baumannii to survive in any state of affairs concerning the gaining of various gene types of virulence and antimicrobial agent resistance are the main anxiety in the hospital’s environments. So, it is very crucial to determine the prevalence of insertion sequences in A. baumannii. In the hospitals. Detecting the blaoxa-51 gene through the polymerase chain reaction (PCR) was performed to confirm Acinetobacter baumannii and the search for ISAba1 element. Between October 2020 and February 2021, 540 distinct clinical specimens were gathered from five hospitals in Baghdad. Thirty-eight A. baumannii isolates were obtained from various clinical specimens. The isolates were initially identified phenotypically using standard microbiological techniques and by the Vitek2 compact automated machine. Isolates of A. baumannii were identified genotypically by amplification of the blaoxa-51-like gene. Antimicrobials are studied by Kirby-Bauer (disc diffusion) technique on Muller-Hinton agar as specified by the recent clinical and laboratory standard institute (CLSI) guidelines (2020). The actual results of the current study indicated that from total isolated (38) A.baumannii isolates, 23 isolates (61%) were resistant to meropenem and 25 isolates (66%) were resistant to imipenem. The blaoxa-51 gene was identified in all strains examined, ISAba1 was also present in all A. baumannii isolates. ISAba1 has a high predominance between drug-resistant A. baumannii. Identifying these parameters can assist in the control of infection and decreasing the microorganism’s prevalence rate.

Synthesis and Characterization of Yttrium-Doped Hydroxyapatite Nanoparticles and Their Potential Antimicrobial Activity

This study reports a detailed analysis of the yttrium doping effects into hydroxyapatite (HAp) nano-structures at different amounts (e.g., 0, 1, 2.5, 5, 7.5, 10, and 15%) on the structural, spectroscopic, dielectric, and antimicrobial properties. For this purpose, seven HAp samples having the Y-contents mentioned above were prepared using the microwave-assisted sol-gel precipitation technique. The structure of synthesized samples was fully described via X-ray diffraction (XRD), scanning electron microscopy (SEM), and Fourier transforms infrared (FTIR). Raman spectroscopy and dielectric measurements were used to characterize the spectroscopic properties. Furthermore, the samples’ antimicrobial features have been assisted through the agar disk diffusion technique. This study showed that the crystallinity decreased with the adding of Y-ions inside the HAp matrix. The Y-contents have influenced the crystallite size, lattice parameters, dislocation density, lattice strain, and unit cell volume. The surface morphology is composed of the agglomerated smaller particles. Remarkable changes in the dielectric properties were observed with the adding of Y-ions. The alternating current conductivity obeys the Jonscher’s relation. Y-doped hydroxyapatite nanoparticles have a considerable inhibitory effect against bacteria and fungi (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, and Candida albicans). The Y-doped hydroxyapatite nanoparticles are a promising material for bone cement engineering with a potential bio-activity

Synthesis, characterization and biological studies of some new organometallic compounds containing mercury, selenium and tellurium based on p-aminobenzoic acid

Ten chalcogen and mercury bearing compounds based on 4-aminobenzoic acid (i.e., (2-amino-5-(ethoxycarbonyl)phenyl)mercury(II) chloride (1), (2-amino-5-(ethoxycarbonyl)phenyl) phenyl selenide (2), (2-amino-5-(ethoxycarbonyl)phenyl) phenyl telluride (3), (4-carboxyphenyl)mercury(II) chloride (4), 4-selenocyanatobenzoic acid (5), 4-tellurocyanatobenzoic acid (6), bis(4-carboxyphenyl) diselenide (7) bis(4-carboxyphenyl) ditelluride (8), bis(4-carboxyphenyl) selenide (9) bis(4-carboxyphenyl) telluride (10) were prepared and characterized by various spectroscopic techniques. All compounds were screened for antibacterial activity against Gram-positive bacterial strains of Staphylococcus aureus and the Gram-negative bacteria Escherichia coli by using the disk diffusion technique. The antibacterial activity of these compounds was dependent on the molecular structure of the compounds, and the bacterial strain under consideration.

Phytochemical analysis and antimicrobial and antioxidant activities of Celosia argentea leaves

This study performed the phytochemical screening and bioactivity of Celosia argentea leaves. The phytochemical profile of hexane (Hex), ethyl acetate (AcOEt) and methanolic (MeOH) extracts of C. argentea leaves was observed by Thin Layer Chromatography and spectrophotometric analysis. In the susceptibility test, the disk-diffusion technique was performed. Minimum Inhibitory Concentration (MIC) was assessed by microdilution. Minimum Microbic Concentration (MMC) was determined in the extracts which presented MIC. Antioxidant activities were measured using 2,2-diphenyl-1-picril-hidrazil (DPPH), determination of reducing power and total antioxidant capacity (TAC). The results showed a higher content of phenolic compounds (252.02 ± 0.02 mg GAE/g) in the extract AcOEt, and of tannins (103.72 ± 0.004 mg/EAT/g) in MeOH; this was effective against Micrococcus luteus (inhibition of 24.7 ± 0.6 mm). MIC and CMM of the AcOEt for M. luteus were 0.06 and 0.25 mg/mL, respectively. The MeOH extract eliminated 70.4 ± 0.03% of DPPH radical, whereas AcOEt had greater reducing power (289.23 ± 0.05 mg AA/g) and TAC at a concentration of 250 µg/mL (89.6%). This study revealed that C. argentea has phytochemicals with bactericidal and fungicidal potential, in addition to elevated antioxidant power. Key words: antimicrobial, antioxidant, bioactivity.