scholarly journals Antimicrobial screening of selected flora of Pakistan

2011 ◽  
Vol 63 (3) ◽  
pp. 691-695 ◽  
Author(s):  
M. Zia-Ul-Haq ◽  
Mansoor Ahmad ◽  
M Mehjabeen ◽  
Noor Jehan ◽  
Shakeel Ahmad ◽  
...  

Ethanolic extracts of Ferula assafoetida resin, Grewia asiatica leaves, Ipomoea hederacea seeds, Lepidium sativum seeds, Nigella sativa seeds and Terminalia chebula fruits were tested in vitro for their antibacterial and antifungal activities. The antibacterial study performed against eight bacterial species viz., Escherichia coli, Citrobacter, Staphylococcus aureus, Pseudomonas aeruginosa, Salmonella typhi, Micrococcus luteus, Proteus mirabilis and Bacillus subtilis indicated that the investigated plants have potent activity against all the tested microorganisms. The antifungal activity of these extracts was performed against nine fungal strains, viz., Aspergillus parasiticus, Aspergillus niger, Yersinia aldovae, Candida albicans, Aspergillus effusus, Fusarium solani, Macrophomina phaseolina, Saccharomyces cerevisiae and Trichophyton rubrum. The extracts showed moderate as well as significant activity against the different fungal strains.

2018 ◽  
Vol 10 (1) ◽  
pp. 67-76
Author(s):  
M. A. Rahim ◽  
M. M. H. Bhuiyan ◽  
M. M. Matin ◽  
M. R. Alam

Two chloroflavones, 6 and 7 along with their corresponding chalcones, 4 and 5 have been tested for antibacterial and antifungal activities against six human pathogenic bacteria viz. Bacillus cereus (G+), Staphylococcus aureus (G+), Escherichia coli (G-), Vibrio choloriae (G-), Pseudomonas aeruginosa (G-), and Salmonella typhi (G-), and four plant as well as mold fungi viz. Aspergillus flavus, Aspergillus ochraceus, Aspergillus niger and Rhizopus spp.. The antibacterial and antifungal screens of the synthesized compounds were performed in vitro by the filter paper disc diffusion method and the poisoned food technique, respectively. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of these synthesized compounds in comparison to ampicillin were also determined by broth micro-dilution method. Some of them were found to possess significant activity, when compared to standard drugs.


2021 ◽  
Author(s):  
Jane Hawkey ◽  
Hugh Cottingham ◽  
Alex Tokolyi ◽  
Ryan R Wick ◽  
Louise M Judd ◽  
...  

Linear plasmids are extrachromosomal DNA that have been found in a small number of bacterial species. To date, the only linear plasmids described in the Enterobacteriaceae family belong to Salmonella, first found in Salmonella Typhi. Here, we describe a collection of 12 isolates of the Klebsiella pneumoniae species complex in which we identified linear plasmids. We used this collection to search public sequence databases and discovered an additional 74 linear plasmid sequences in a variety of Enterobacteriaceae species. Gene content analysis divided these plasmids into five distinct phylogroups, with very few genes shared across more than two phylogroups. The majority of linear plasmid-encoded genes are of unknown function, however each phylogroup carried its own unique toxin-antitoxin system and genes with homology to those encoding the ParAB plasmid stability system. Passage in vitro of the 12 linear plasmid-carrying Klebsiella isolates in our collection (which include representatives of all five phylogroups) indicated that these linear plasmids can be stably maintained, and our data suggest they can transmit between K. pneumoniae strains (including members of globally disseminated multidrug resistant clones) and also between diverse Enterobacteriaceae species. The linear plasmid sequences, and representative isolates harbouring them, are made available as a resource to facilitate future studies on the evolution and function of these novel plasmids.


2012 ◽  
Vol 2 (5) ◽  
pp. 217-226
Author(s):  
E. O. Omwenga ◽  
P. O. Okemo ◽  
P. K. Mbugua

The antimicrobial effect of some selected Samburu medicinal plants was evaluated on bacterial strains like Staphylococcus aureus ‐ ATCC 20591, Bacillus subtillis ‐ Local isolate, Salmonella typhi‐ATCC 2202, Escherichia coli‐STD. 25922 and Pseudomonas aeroginosa ‐ ATCC 25852 and fungal strains like Candida albicans ATCC EK138, Aspergillus niger ATCC 16404, Aspergillusflavus‐Local isolate, Fusarium lateritium‐Local isolate, and Penicillium spp.‐ local isolate. Methanol was used as solvent for the extraction from the selected medicinal plants used by the Samburu community. The in vitro antimicrobial activity was performed by agar disc diffusion and micro‐dilution technique. The most susceptible Gram‐positive bacterium was S. aureus, while the most susceptible Gram‐negative bacterium was P. aeroginosa. The extracts of Gomphocarpus fruticosus (L) W.T. Aiton showed less activity against the bacterial strains investigated. The most active antibacterial plants were Euphorbia scarlatica S. Carter, and Euclea divinoram Hiern. Incidentally most of the extracts were inactive against the fungal strains with only a few proving to be slightly active against the C. albicans i.e. Loranthus acaciae Zucc., Kedrostis pseudogijef (Gilg) C. Jeffrey, Euclea divinoram Hiern. and Croton macrostachyus (A. Rich). Benths. The significant antimicrobial activity of active extracts was compared with the standard antimicrobials, cefrodoxima, amoxicillin and fluconazole. The MICs of the most active plants ranged from 18.75mg/ml to 37.50mg/ml. The MBCs ranged between 18.75mg/ml to75mg/ml. These results were significant at P< 0.01. The findings show that most of the medicinal plants used by the Samburu community have some significant activity on the bacterial but not fungal pathogens known to cause diarrhoea.


Author(s):  
Mohammed M Matin ◽  
Mohammad Ibrahim ◽  
Md Shafiqur Rahman

A number of 2,3-di-O-acyl derivatives (6-11) of methyl 4-O-acetyl-a-Lrhamnopyranoside (5) obtained by using various acylating agents were screened for in vitro antifungal activity against four plant pathogenic fungi, viz., Alternaria alternata, Curvularia lunata. Fusarium equiseti and Macrophomina phaseolina. These compounds were also screened for in vitro antibacterial activity against ten human pathogenic bacteria, viz., Bacillus subtilis, Bacillus cereus, Bacillus megaterium, Staphylococcus aureus, Escherichia coli, INABA ET (Vibrio), Pseudomonas species, Salmonella paratyphi, Shigella dysenteriae and Salmonella typhi. The study reveal that these 4-O-acetyl-?-L-rhamnopyranoside derivatives are more prone towards antifungal activities than that of antibacterial activities. DOI: http://dx.doi.org/10.3329/cujbs.v3i1.13404 The Chittagong Univ. J. B. Sci.,Vol. 3(1&2):33-43, 2008


2010 ◽  
Vol 75 (6) ◽  
pp. 739-747 ◽  
Author(s):  
Dinesh Bisht ◽  
Rajendra Padalia ◽  
Lalit Singh ◽  
Veena Pande ◽  
Priyanka Lal ◽  
...  

The essential oils from six Himalayan Nepeta species, viz. Nepeta leucophylla Benth., Nepeta discolor Royle ex Benth., Nepeta govaniana Benth., Nepeta clarkei Hook f., Nepeta elliptica Royle ex Benth. and Nepeta erecta Benth., were tested for their in vitro antimicrobial activity against six pathogenic bacterial and two fungal strains. The results showed that Pseudomonas aeruginosa was the most sensitive strain tested to the essential oils of Nepeta species. The essential oils of N. elliptica and N. erecta exhibited the highest activity against P. aeruginosa, followed by the essential oils of N. leucophylla and N. clarkei. The essential oils from N. elliptica and N. erecta were also found to be very effective against Serratia marcescens; while the essential oil from N. leucophylla displayed significant activity against Proteus vulgaris and Staphylococcus aureus. Other bacterial strains displayed variable degree of susceptibility against one or more of the tested essential oils. The essential oil from N. leucophylla also showed the highest antifungal activity against both tested fungal strains, viz. Candida albicans and Trichophyton rubrum, followed by the essential oils from N. clarkei, N. govaniana and N. erecta. Iridodial derivatives, viz. iridodial ?-monoenol acetate (25.4 %), dihydroiridodial diacetate (18.2 %) and iridodial dienol diacetate (7.8 %) were identified as the major constituents of N. leucophylla, while the essential oils from N. elliptica and N. erecta were dominated by (7R)-trans, trans nepetalactone (83.4 %) and isoiridomyrmecin (66.7 %), respectively. The essential oil of N. discolor was characterized by 1,8-cineole (25.5 %) and ?-caryophyllene (18.6 %), while N. clarkei was dominated by ?-sesquiphellandrene (22.0 %) and germacrene D (13.0 %). Isoiridomyrmecin (35.2 %) and pregeijerene (20.7 %) were identified as the major constituents of N. govaniana. In general the Nepeta species containing constituents with an iridoid or lactone skeleton were found to have the greater antagonistic activity against most of the microbial strains as compared to those containing regular terpene constituents.


2010 ◽  
Vol 75 (8) ◽  
pp. 1075-1084 ◽  
Author(s):  
Muhammad Imran ◽  
Mitu Liviu ◽  
Shoomaila Latif ◽  
Zaid Mahmood ◽  
Imtiaz Naimat ◽  
...  

The condensation reactions of biacetyl with orthohydroxyaniline and 2-aminobenzoic acid to form bidendate NO donor Schiff bases were studied. The prepared Schiff base ligands were further utilized for the formation of metal chelates having the general formula [ML2.2H2O] where M = Co(II), Ni(II), Cu(II) and Zn(II) and L = HL1 and HL2. These new compounds were characterized by conductance measurements, magnetic susceptibility measurements, elemental analysis, and IR, 1H-NMR and electronic spectroscopy. Both Schiff base ligands were found to have a mono-anionic bidentate nature and octahedral geometry was assigned to all metal complexes. All the complexes contained coordinated water which was lost at 141-160 ?C. These compounds were also screened for their in-vitro antibacterial activity against four bacterial species, namely; Escherichia coli, Staphylococcus aureus, Salmonella typhi and Bacillus subtillis. The metal complexes were found to have greater antibacterial activity than the uncomplexed Schiff base ligands.


Author(s):  
Özden Salman ◽  
Raziye Koçak ◽  
Nuh Boyraz

Macrophomina phaseolina is a soil pathogen known as charcoal rot and can cause up to 90% yield loss in sunflower under suitable conditions. The serious damage caused by chemicals used in the control of soil-borne pathogens to the environment and health has become one of the most important concerns in agriculture. Therefore, in our study, it was aimed to determine the in vitro antagonistic effects of various bacterial species against M phaseolina. A total of 38 bacterial strains were isolated from soil samples in the rhizosphere of Malva sylvestris (hibiscus), Vicia sativa (vetch), Cicer arietinum (chickpea), Papaver rhoeas (weasel), Carlina marianum (thistle), Glebionis coronaria (crown daisy) and Vicia faba collected from Urla district of İzmir. All bacterial strains exhibited antibiosis effect under in vitro conditions, but it was determined that 5 bacterial isolates among them showed a high inhibition zone and showed an average inhibition potential ranging between 55% and 74%. The most effective bacteria identified at species and genus level by Maldi biotyping (MALDI-TOF MS) were identified as Bacillus amyloliquefaciens, Stenotrophomonas sp. and Bacillus cereus (3 isolates), and these species showed that they can be important biocontrol agents in biological control against M. phaseolina.


2009 ◽  
Vol 4 (4) ◽  
pp. 493-498 ◽  
Author(s):  
Olgica Stefanovic ◽  
Dragana Stanojevic ◽  
Ljiljana Comic

AbstractAntibacterial and antifungal activities of aqueous, ethanol and ethyl acetate extract of Torilis anthriscus (L.) Gmel. (Apiaceae) were tested in vitro against ten species of bacteria and five of fungi. Antimicrobial properties were determined by disk diffusion and broth tube dilution method. In the minimum inhibitory concentrations (MICs), the ethanol extract showed the highest activity, followed by the ethyl acetate extract and the aqueous extract against bacterial species, while the extracts were inactive against the tested fungi species. The most active extract was chosen to examine the effects of its combinations with commercial antibiotics by checkerboard method. The obtained results showed that the interactions between ethanol extract/streptomycin and ethanol extract/chloramphenicol were additive and indifferent against the tested human-pathogenic bacteria. Synergism and antagonism were not observed.


2004 ◽  
Vol 72 (2) ◽  
pp. 175-185 ◽  
Author(s):  
E. R. EI-Bendary ◽  
F. E. Goda ◽  
A. R. Maarouf ◽  
F. A. Badria

A series of quinoxaline derivatives has been synthesized by reacting 3-hydrazinoquinoxalines 1a,b with many bifunctional reagents. Reaction of 1a,b with chloroacetyl chloride and ethyl chloroacetate afforded 1-chloromethyl[1,2,4]tnazoIo[4,3-a]quinoxalines 2a,b and dihydro[1,2,4]triazino[4,3-a]quinoxalin-2-ones 3a,b respectively. Condensation of 1a,b with ethyl acetoacetate and acetylacetone yielded 2-quinoxalinylhydrazonobutanoates 4a,b and 2-quinoxalinylhydrazono-2-pentanones 5a,b respectively. Cyclization of 5a,b gave 3,5-dimethylpyrazolylquinoxalines 6a,b. Moreover, reaction of compounds 2a,b with N-phenyl piperazine derivatives afforded 4-(4-Arylpiperazin-1-yl)-1-[(4-arylpiperazin-1-yl) methyl)]triazoloquinoxalines 7a−e. The prepared compounds were screened for in vitro antibacterial and antifungal activities. None of the tested compounds showed significant activity towards Pseudomonas aeruginosa. However, remarkable activities were noticed for compounds 5a and 5b against Eschenchia coli. Staphylococcus aureus and Candida albicans. Compounds 6a and 6b lacked any antimicrobial activities against the tested microorganisms.


2022 ◽  
Vol 11 (1) ◽  
pp. 139-146 ◽  
Author(s):  
Nagaraj Adki ◽  
Neelofer Rana ◽  
Ramesh Naik Palthya

A new series of 2-[3-(5-methyl-1-phenyl-1H-1,2,3-triazol-4-yl)-1-phenyl-1H-4-pyrazolyl]-3-aryl-1,3-thiazolan-4-one 5(a-i) have been designed, synthesized and evaluated for their in vitro antibacterial activity against Gram positive bacteria viz. Bacillus subtilis (ATCC 6633), Staphylococcus aureus (ATCC 6538p), Micrococcus luteus (IFC 12708) and Gram negative bacteria viz. Proteus vulgaris (ATCC 3851), Salmonella typhimurium (ATCC 14028), Escherichia coli (ATCC 25922) the antifungal activity against Candida albicans (ATCC 10231), Aspergillus fumigatus (HIC 6094), Trichophyton rubrum (IFO 9185), Trichophyton mentagrophytes (IFO 40996). Antibacterial evaluation indicates that compounds containing 4-methoxyphenyl 5c, 4-fluorophenyl 5d and 2,5-difluorophenyl 5h groups on thiazolidinone ring showed significant activity equal to that of standard drug. The antifungal evaluation shows that compound 5c is highly active against A. fumigatus, compound 5d and 5h were also active against C. albicans and A. fumigatus.


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