Browsing by Author "Supervisor Dr. Bashir Ahmad"

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    ISOLATION, OPTIMIZATION AND CHARACTERIZATION OF SECONDARY METABOLITES FROM SOIL BORNE FUNGI SCRELOTIUM AND ASPERGILLUS SPECIES
    (Center of Biotechnology & Microbiology, University of Peshawar, 2016) Muhammad Rizwan; Supervisor Dr. Bashir Ahmad
    In the present dissertation, our research findings on the production of bioactive secondary metabolites by soil borne fungi are discussed. The application of microorganisms for the welfare of human beings is the main goal of biotechnology. In this study, two phytopathogenic fungi, Sclerotium rolfsii and Aspergillus flavus were isolated from soil samples collected from Malakand Division, Khyber Pakhtunkhwa, Pakistan. Growth parameters (nutrient media, temperature, pH, incubation period, and static/shaking intervals) were optimized for achieving maximum production of bioactive secondary metabolites. Five nutrient media were used for fungal growth. S. rolfsii produced maximum amounts of metabolites in Czapek yeast broth media (CYB), whereas maximum formation of metabolites by A. flavus was found in potato dextrose media (PDB). Furthermore, the crude secondary metabolites in ethyl acetate (EtOAc) and n-hexane extract obtained from each medium were screened for their activities against different pathogenic bacteria. The EtOAc and n-hexane fractions obtained from the CYB medium were more active against pathogenic bacteria as compared to the crude metabolites obtained from the other media in the case with S. rolfsii, whereas PDB was the media, in which A. flavus yielded the largest quantities of secondary metabolites, showed significant results against pathogenic bacteria. EtOAc and n-hexane fractions of both fungi were screened for their in vitro effects, including antifungal, phytotoxic, and insecticidal properties and brine shrimp lethality. The in vivo activities of the metabolites, such as acute toxicity, analgesic, and sedative action, were also studied. The results showed that the ethyl acetate (EtOAc) fraction was more active as compared to the n-hexane fraction due to the presence of polar constituents. The results obtained from the examinations of the biological activities indicated that both fungi produced bioactive secondary metabolites which have antimicrobial, phytotoxic, insecticidal, cytotoxic, analgesic, and sedative effects.
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    Molecular Epidemiology of Staphylococcus A Case Study of Khyber Pakhtunkhwa, Pakistan
    (Center of Biotechnology & Microbiology, University of Peshawar, 2015) FARMAN ULLAH; Supervisor Dr. Bashir Ahmad
    The present study was conducted from June 2010 to June 2014 in Khyber Teaching Hospital (KTH) and Hayatabad Medical Complex (HMC), Peshawar, Pakistan to know about the prevalence of resistance to antibiotics and molecular epidemiology of Staphylococcus aureus. The specimens include pus, blood and urine received for culture and sensitivity. S. aureus were identified at molecular level using polymerase chain reaction (PCR). The identified strains were subjected to antimicrobial testing by disc diffusion method and minimum inhibitory concentration (MIC) method according to the guide lines ofclinical laboratory and standards institute (CLSI). Cefoxitin, 30 pg discs were also applied in the culture sensitivity to find methicillin resistant S. aureus (MRSA) strains. Majority of S. aureus wereisolated from skin infections. A total of 273 (61.34%) isolates were found to be MRSA out of 445. The samples collected from KTH’s clinical laboratory were named as KLS (n=167), KTH’s environmental samples as KE (n=64), KTH’s blood isolates as KLBS (n=15), KTH’s currency notes as CRN (n=18), KTH’s burn ward samples as KBRN (n=89) and the isolates collected from Hayatabad medical complex were named as HMC (n=92). As a whole, amongtheantibiotics tested against S. aureus, vancomycin was most potent among alLantibiotics to which 89.89% isolates were susceptible. Next to vancomycin were fusidic acid, rifampicin, linezolid and chloramphenicol inhibiting 84.94, 83.37, 83.15 and 81.12 % of the isolates respectively. Among the 445 isolates, 73.03% were susceptible to doxycycline, 62.47 % to amikacin and 60% to meropenem. Gentamicin, clarithromycin and ciprofloxacin had average activity, ie. 53.93, 44.04 and 41.57 % respectively. Rest of the antibiotics had below 40 % activities. MRSA strains were found more resistant as compared to MSSA. Thereason for erythromycin resistance was genetically investigated.