Antibiotic is a type of medication that helps in fighting bacterial infection. Treating bacterial infections in clinical setting become more complicated and costly due to drug resistance. This study was conducted to determine the antibacterial potential of Psidium guajava Linn leaf extracts against Gram-positive and Gram-negative bacteria. P. guajava Linn leaf was obtained from Research Orchards at University Putra Malaysia (UPM). Leaves were extracted using three types of extracts; hot, cold and methanol extract. Freeze dried was used in this study and temperature was set at -104°C for 24 hours. Antibacterial testing was determined using disc diffusion and well diffusion method. Antibacterial activity was evaluated by measuring the inhibitory zone of the tested bacteria. Phytochemical analysis was conducted by adding few drop of diluted NaOH (Sodium Hydroxide) solution to detect the active flavanoid from leaves extract. Antimicrobial activity showed all extracts were effective against Gram-positive and Gram-negative bacteria. Phytochemical analysis of P. guajava Linn leaf extracts showed the methanol extract indicating the presence of tannins, phenols, flavonoids, terpenoids, glycosides and saponins. Results showed that P. guajava Linn leaf was effective against Gram-positive and Gram-negative bacteria, and pythochemical analysis also exhibited a few active compounds that were determined. P. guajava Linn leaf had potential natural product that may be used for further analysis in the future research.

Dermatomycosis is a fungal infection of the skin, hair and nail caused by Trichophyton, Microsporum and Epidermophyton. These organisms are found in the environment, humans and animals in forms of yeast or mold. There are many factors that contribute to the growth of fungal infections in human body. But still majority of virulent factors and mechanisms of the diseases of fungi are not clear. This review paper describes types of fungal infections, their classification, epidemiology and new insights into pathogenesis with the focus on molecular mechanisms of the diseases. Furthermore, traditional and novel molecular diagnostic methods and the variety of drug treatment and the development of resistance against these drugs are discussed.

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Antibacterial activity of different types of P. odorata leaf extracts was evaluated in combination with standard antibiotics. Persicaria. odorata leaves were extracted with n-hexane (n-hex), dichloromethane (DCM) and methanol (MeOH).  Each extract was applied on vancomycin (30µg), erythromycin (15µg) and gentamicin (10µg) discs, respectively. Disk diffusion method was used to evaluate the synergistic activity of each combination on Staphylococcus aureus, Staphylococcus epidermidis, Streptococcus pyogenes, Streptococcus pneumoniae, Pseudomonas aeruginosa, Salmonella typhi, and Escherichia coli. Minimum inhibitory concentration (MIC) and gas chromatography mass spectrometry (GCMS) analysis was performed on the active extract. Synergistic effects seen were mainly from the n-hex+antibiotics combinations, mainly on the Gram-positive bacteria (7 additive, 5 antagonistic), with MIC range from 50 µg/ml to 100 µg/ml, as well as Gram-negative bacteria (2 additive, 2 indifferent, 5 antagonistic). In particular, synergism showed by the combination of n-hex+van were all additive against the susceptible bacteria. DCM extract combination showed synergistic effects on three Gram-positive species (S. aureus, S. epidermidis, S. pyogenes). Meanwhile, MeOH+antibiotics combination showed significant additive synergistic effects (p<0.05) on S. aureus and S. epidermidis.  The major compounds of leaves extract were decanal and β-citral. n-Hex extract superiorly inhibited Gram-positive bacteria growth as compared to DCM and MeOH extracts. The additive synergistic property of the n-hex P. odorata extract could be further studied for possible use as an antibacterial agent.

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