- About this Journal ·
- Abstracting and Indexing ·
- Aims and Scope ·
- Annual Issues ·
- Article Processing Charges ·
- Author Guidelines ·
- Bibliographic Information ·
- Citations to this Journal ·
- Contact Information ·
- Editorial Board ·
- Editorial Workflow ·
- Free eTOC Alerts ·
- Publication Ethics ·
- Recently Accepted Articles ·
- Reviewers Acknowledgment ·
- Submit a Manuscript ·
- Subscription Information ·
- Table of Contents
The Scientific World Journal
Volume 2014 (2014), Article ID 269793, 7 pages
In Vitro Phytochemical, Antibacterial, and Antifungal Activities of Leaf, Stem, and Root Extracts of Adiantum capillus veneris
1Department of Microbiology, Faculty of Life Sciences, Abasyn University, Peshawar 25000, Pakistan
2Medicinal Botanic Centre, PCSIR Labs Complex, Peshawar 25120, Pakistan
3Department of Microbiology, Shaheed Benazir Bhutto Women University, Peshawar 25000, Pakistan
4Department of Chemistry, Kohat University of Science and Technology, Kohat 26000, Pakistan
Received 31 August 2013; Accepted 24 November 2013; Published 28 January 2014
Academic Editors: F. Bussotti, M. Chen, R. Creamer, and N. Suganuma
Copyright © 2014 Muhammad Saqib Ishaq et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
Adiantum capillus veneris is a medicinally essential plant used for the treatment of diverse infectious diseases. The study of phytochemical and antimicrobial activities of the plant extracts against multidrug-resistant (MDR) bacteria and medically important fungi is of immense significance. Extracts from the leaves, stems, and roots of Adiantum capillus veneris were extracted with water, methanol, ethanol, ethyl acetate, and hexane and screened for their antimicrobial activity against ten MDR bacterial strains and five fungal strains isolated from clinical and water samples. Ash, moisture, and extractive values were determined according to standard protocols. FTIR (Fourier transform infrared Spectroscopy) studies were performed on different phytochemicals isolated from the extracts of Adiantum capillus Veneris. Phytochemical analysis showed the presence of flavonoids, alkaloids, tannins, saponins, cardiac glycosides, terpenoids, steroids, and reducing sugars. Water, methanol, and ethanol extracts of leaves, stems, and roots showed significant antibacterial and antifungal activities against most of the MDR bacterial and fungal strains. This study concluded that extracts of Adiantum capillus veneris have valuable phytochemicals and significant activities against most of the MDR bacterial strains and medically important fungal strains.
Among foremost health problems, infectious diseases account for 41% of the global disease burden along with noninfectious diseases (43%) and injuries (16%) . The main reasons of these infectious diseases are the natural development of bacterial resistance to various antibiotics [2, 3]. The development of multidrug-resistant (MDR) bacteria takes place because of the accumulation of different antibiotic resistance mechanisms inside the same strain [2, 4]. Although, in previous decades, the pharmacological companies have produced a number of new antibiotics, but even then drug resistance has increased . This situation has forced the attention of researchers towards herbal products, in search of development of better-quality drugs with improved antibacterial, antifungal, and antiviral activities [6, 7].
According to world Health Organization (WHO), 80% of the World’s population is dependent on the traditional medicine . Herbal plants are rich sources of safe and effective medicines  and are used throughout the history of human beings either in the form of plant extracts or pure compounds against various infectious diseases . For the treatment of infectious diseases, different medicinal plants have been mentioned by many phytotherapy manuals because of their reduced toxicity, uncomplicated availability, and fewer side effects . Various studies have been conducted worldwide to describe the antimicrobial activities of different plant extracts [12–18]. Numerous plants have been investigated for treatment of urinary tract infections, gastrointestinal disorders, and respiratory and cutaneous diseases .
Adiantum capillus veneris is a common fern found in pak-indian subcontinent, Mexico, western Himalaya, warmer parts of America, and other tropical and subtropical regions of the world [20, 21]. It is used as expectorant, emmenagogue, astringent, demulcent, antitussive, febrifuge, diuretic and catarrhal affections . Different extracts obtained from Adiantum had shown potential antibacterial activities against Staphylococcus aureus, Streptococcus pyogenes, Klebsiella pneumoniae, Escherichia coli, and antifungal activity against Candida albicans .
For few decades, phytochemicals (secondary plant metabolites), with unidentified pharmacological activities, have been comprehensively investigated as a source of medicinal agents . Thus, it is expected that phytochemicals with sufficient antibacterial efficacy will be used for the cure of bacterial infections . Many phytochemicals have been found in Adiantum capillus veneris like oleananes, phenylpropanoids, flavonoids, triterpenoids, carotenoids, carbohydrates, and alicyclics .
The present work was therefore designed to investigate the phytochemical, antibacterial, and antifungal activities of methanol, ethanol, water, ethyl acetate, and hexane extracts of leaves, stems, and roots of Adiantum capillus veneris against MDR bacterial strains isolated from community acquired and nosocomial infections and medicinally important fungi.
2. Materials and Methods
2.1. Plant Material Collection and Extraction
Adiantum capillus veneris was collected from different areas of Swat and Peshawar and then identified by the Department of Botany, University of Peshawar. For the collection of different extracts, the leaves, stems, and roots were separately shadow dried by the same method of Shalini and Sampathkumar . The leaves, stems, and roots were separately ground to homogenous powder. 100 g of each powder, that is, leaves, stems, and roots was soaked in 1 liter of each distilled water, methanol, ethanol, ethyl acetate and hexane for 24 h at 25°C and then filtered through Whatman No. 1 filter paper. According to previously described methods, the filtrates were collected in separate flasks and the same process was repeated three times . The filtrates, that is, crude extracts obtained were concentrated in rotary evaporator. For the isolation of pure extracts, the isolated crude extracts were resuspended in a minimum required volume of corresponding solvents and placed on the water bath (60°C) for the evaporation of extra solvents. These extracts were then preserved in separate containers for further experimentations at 5°C, according to previous methods .
2.2. Ash, Moisture, Extractive Values, Phytochemical Screening, and FTIR Study of Plant Extracts
Ash value of whole plant was found out by the method of Premnath et al. . Moisture value of whole plant was determined by the same method as of Ashutosh et al. . Extractive values of all the fifteen extracts of leaves, stems, and roots were carried out separately by the method described by Singh et al. . Different types of phytochemical tests were performed for the presence of alkaloids, tannins, saponins, flavonoids, steroids, terpenoids, glycosides, and reducing sugars [31–33]. The FTIR (Fourier transform infrared Spectroscopy) model used was IR Pretige-21 (Shimadzu, Japan) with IR Solutions software . FTIR spectroscopy was carried out for all the extracts in dried form by the method used by Meenambal et al. .
2.3. Collection and Identification of Bacterial Cultures
The bacterial samples were obtained from the laboratories of Lady Reading Hospital, Peshawar, and Pakistan council of scientific and industrial research (PCSIR), Peshawar. Bacterial species, that is, Citrobacter freundii, Escherichia coli, and Providencia species were isolated from urine samples, Klebsiella pneumoniae, Proteus vulgaris, Salmonella typhi, Shigella, and Vibrio cholerae from water sample while Pseudomonas aeruginosa and Staphylococcus aureus were isolated from pus samples. The isolated bacterial species were subcultured on selective and differential media, for example, CLED agar and MacConkey, and were identified through their specific characteristics, that is, morphological, staining, and biochemical, according to previously described methods .
2.4. Collection and Identification of Fungal Cultures
The fungal samples, that is, Candida albicans, Pythium, Aspergillus flavis, Aspergillus niger, and Trichoderma, were obtained from the microbiology laboratory of Abasyn University Peshawar. The collected fungal species were subcultured on potato dextrose agar (PDA) and were confirmed by staining and morphological characteristics according to the standard method .
2.5. Assessment of Drug Resistance Pattern of the Test-Bacterial Strains
Disk diffusion method was used for measurement of the antimicrobial activity on Muller Hinton agar. The sensitivity of fourteen antibiotics was tested against the previously mentioned ten bacterial strains (Table 3) and the process was repeated for three times. All the plates were incubated for 24 h at 37°C .
2.6. Evaluation of Antimicrobial Activity of Extracts
For the assessment of antimicrobial activities of all the fifteen extracts of Adiantum capillus veneris, the well diffusion method of Janovska et al.  was followed with some modifications. One mg of plant extract was dissolved in 1 mL of DMSO (dimethyl sulfoxide). Preautoclaved Muller Hinton agar plates were inoculated with a 10−5 dilution of bacterial cultures with sterile cotton swabs, for uniform growth. To test the activity of plant extracts, sterile cork borer was used to bore wells in the agar. 60 μL of each extract, that is, LW (leaves water), LM (leaves methanol), LE (leaves ethanol), LEA (leaves ethyl acetate), LH (leaves hexane), SW (stem water), SM (stem methanol), SE (stem ethanol), SEA (stem ethyl acetate), SH (stem hexane), RW (root water), RM (root methanol), RE (root ethanol), REA (root ethyl acetate), and RH (root hexane), was introduced through micropipette aseptically into distinctively marked wells in the agar plates. All the plates were incubated for 24 h at 37°C and the process was repeated thrice.
2.7. Antifungal Activity of Plant Extracts
Well diffusion method of Mbaveng et al.  was used for the evaluation of antifungal activities of plant extracts. Preautoclaved PDA plates were inoculated with dilution of fungal cultures. 60 μL of each extract, that is, SWE, SME, SEE, SEAE, SHE, LWE, LME, LEE, LEAE, LHE, RWE, RME, REE, REAE, and RHE was introduced through micropipette aseptically into distinctively marked wells in the agar plates. All the plates were incubated for 72 h at 37°C and the process was repeated in triplicate.
3.1. Ash, Moisture, and Extractive Value
The ash value of the whole plant was 7.81% and moisture value was 10% while extractive values were separately calculated for all the 15 extracts. LM extract had a greater percentage of extractive value (35%) followed by REA (23.6%), SM (20%), LE (20%), RE (18%), RW (17.72%), SE (16.2%), RM (16%), SEA (12%), LW (12%), LEA (10.7%), LH (8%), RH (4.32%), SW (4%), and SH (2.75%) (Table 1).
3.2. Phytochemical Screening
It is evident from Table 2 that many phytochemicals were present in Adiantum capillus veneris.
3.3. FTIR Spectroscopy
FTIR spectroscopy was used for the compound identification and run under IR region between the ranges of 400 and 4000 cm−1. The peaks (see Figures 1 to 15 in Supplementary Material available online at http://dx.doi.org/10.1155/2014/269793) showed that the plant has compounds such as aldehyde, amides, alcohol, carboxylic acid, ketone and ethers, and so forth.
3.4. Drug Resistance Pattern of the Test-Bacterial Strains
The MDR bacterial strains were tested for antibiotic sensitivity against 14 frequently used antibiotics. Most of the tested bacterial strains were found to be resistant to the used antibiotics. Citrobacter freundii was the most resistant strain (92.8%) that showed relatively low sensitivity only to tetracycline (TET) (10 mm), among all the tested organisms. Second most resistant strain (85.7%) was Klebsiella pneumoniae which showed sensitivity only to gentamicin (GEN) (15 mm) and cefoperazone-sulbactam, (CZS) (15 mm) followed by Providencia (85.7%), which showed sensitivity to cefotaxime (CTX) (22 mm) and ceftriaxone (CRO) (18 mm). Proteus vulgaris and Escherichia coli were 78.6% resistant while vibrio cholera and Salmonella typhi were 71.4% resistant to all tested antibiotics. Pseudomonas aeruginosa and Staphylococcus aureus were found 50% resistant while Shigella was 35.8% resistant against all 14 test- antibiotics (Table 3).
3.5. Assessment of Antibacterial Activity of Plant Extracts
The leaves, stems and root extracts of Adiantum capillus veneris were tested against ten MDR bacterial strains. 60 μL (1 mg/1 mL) of each extract was used for antimicrobial activity estimation through well diffusion method. LM, LE, LW, SM, SE, SW, RM, RE, and RW extracts of Adiantum capillus veneris showed significant antibacterial activity against all the test bacterial strains (Table 4).
The results were recorded after a 24-hour incubation, according to the ZI of each antibiotic for all tested bacterial strains.
3.6. Assessment of Antifungal Activity of Plant Extracts
Water, methanol, and ethanol extracts of leaves, stems, and roots of Adiantum capillus veneris showed maximum ZI against tested fungal strains while hexane extract of leaves, stems and, roots has shown no activity. LM extract has shown highest zone against Candida albicans ( mm), Aspergillus flavis ( mm), Aspergillus niger ( mm), Pythium ( mm), and Trichoderma ( mm). Similarly, LW, LE, LE, LEA, SW, SM, SEA, RW, RM, RE, and REA were also very active against most the test-fungal strains as evident from Table 5.
The attention of researchers has been deviated by the increasing emergence of antibiotic resistance towards the medicinal plants in search of new, less toxic, and useful drugs. Plants are the reservoirs of valuable phytochemicals. Many plants have been investigated worldwide for their antimicrobial and phytochemical activities. Therefore, this study has been carried out to evaluate the phytochemical and antimicrobial activities of water, methanol, ethanol, ethyl acetate, and hexane extracts of leaves, stems, and roots of Adiantum capillus veneris.
Ash, moisture, and extractive values of all fifteen extracts of Adiantum capillus veneris were determined. Except for the ash value of whole plant which is in accordance with the study of Ahmad et al. , the moisture and extractive values reported in our study have not been investigated before, to the best of our knowledge.
The result of phytochemical screening of all extracts of leaves, stems, and roots of Adiantum capillus veneris showed the presence of alkaloids, flavonoides, tannins, saponins, terpenoids, steroids, glycosides, and reducing sugars (Table 2) which is in line with many other studies conducted worldwide [25, 41, 42]. FTIR results of our study have showed the presence of many new compounds, that is, aldehyde, amides, alcohol, carboxylic acid, ketone, and ethers (Figures 1–15, supplementary data), most of which are not reported previously.
In the present study, 10 bacterial strains were used which were MDR to most of the given antibiotics (Table 3). Our results showed that Citrobacter freundii was the most resistant strain (92.8%) among all the tested bacterial strains. Our findings are in line with the studies conducted in other areas of Pakistan where 100% MDR Citrobacter has been reported . Additionally, 92.8% MDR Citrobacter seen in the present study is also observed in Ethiopia (100% MDR)  and Nepal (86.95%) . Similarly, 85.7% MDR Klebsiella pneumoniae found in this study is almost in agreement with 81.8% MDR investigated locally  in early 2013. We investigated 85.7% MDR Providencia, almost similar to the study of Tumbarello et al. (75%) . We have also investigated that Escherichia coli, P. vulgaris, Salmonella typhi, V. cholera, Staphylococcus aureus, Pseudomonas aeruginosa, and Shigella are rather more MDR (Figure 1) than what was found in other regions of the world, as evident from various studies [48–50] on these bacterial strains.
Numerous studies on Adiantum capillus veneris showed its potency against MDR bacterial strains. For example, Escherichia coli, Staphylococcus aureus, and Klebsiella Pneumoniae were sensitive to LW, LM, SW, and SM extracts of Adiantum capillus veneris in our study which proved to be almost in accordance with the findings of Mahboubi et al.  and kumar and Nagarajan  from Iran and India, respectively. We have found out that most of the extracts of Adiantum capillus veneris were very effective against the MDR bacterial strains as compared to other studies [52, 53] which might be due to the variation in procedures, geographical conditions, and so forth. In comparison to the antibiotics used, the plants extracts were very active against the test bacterial strains, which is evident from the comparison of Tables 3 and 4. Likewise, as compared to other studies [22, 54], all extracts except hexane used in our studies were far more effective against test-fungal strains.
The present study confirms that fractions of Adiantum capillus veneris have significant antibacterial and antifungal activity along with valuable phytochemicals. Different fractions have different antibacterial and antifungal activities against MDR bacterial and fungal strains. It is recommended that further research should be conducted for more effective outcomes.
Conflict of Interests
The authors declare that there is no conflict of interests regarding the publication of this paper.
- J. A. K. Noumedem, M. Mihasan, S. T. Lacmata, et al., “Antibacterial activities of the methanol extracts of ten Cameroonian vegetables against Gram-negative multidrug-resistant bacteria,” BMC Complementary and Alternative Medicine, vol. 13, article 26, 2013.
- I. Chopra, “New drugs for superbugs,” Microbiology Today, vol. 47, pp. 4–6, 2000.
- H. Westh, C. S. Zinn, V. T. Rosdahl et al., “An international multicenter study of antimicrobial consumption and resistance in Staphylococcus aureus isolates from 15 hospitals in 14 countries,” Microbial Drug Resistance, vol. 10, no. 2, pp. 160–168, 2004.
- H. Harbottle, S. Thakur, S. Zhao, and D. G. White, “Genetics of antimicrobial resistance,” Animal Biotechnology, vol. 17, no. 2, pp. 111–124, 2006.
- G. G. F. Nascimento, J. Locatelli, P. C. Freitas, and G. L. Silva, “Antibacterial activity of plant extracts and phytochemicals on antibiotic-resistant bacteria,” Brazilian Journal of Microbiology, vol. 31, no. 4, pp. 247–256, 2000.
- Z. C. Maiyo, R. M. Ngure, J. C. Matasyoh, and R. Chepkorir, “Phytochemical constituents and antimicrobial activity of leaf extracts of three Amaranthus plant species,” African Journal of Biotechnology, vol. 9, no. 21, pp. 3178–3182, 2010.
- N. Benkeblia, “Antimicrobial activity of essential oil extracts of various onions (Allium cepa) and garlic (Allium sativum),” Lebensmittel-Wissenschaft & Technologie, vol. 37, no. 2, pp. 263–268, 2004.
- S. S. Kumar and N. Nagarajan, “Screening of preliminary phytochemical constituents and antimicrobial activity of Adiantum capillus veneris,” Journal of Research in Antimicrobial, vol. 1, no. 1, pp. 56–61, 2012.
- S. Tiwari, “Plants: a rich source of herbal medicine,” Journal of Natural Products, vol. 1, pp. 27–35, 2008.
- J. Parekh and S. V. Chanda, “In vitro antimicrobial activity and phytochemical analysis of some Indian medicinal plants,” Turkish Journal of Biology, vol. 31, no. 1, pp. 53–58, 2007.
- R. Khan, B. Islam, M. Akram et al., “Antimicrobial activity of five herbal extracts against Multi Drug Resistant (MDR) strains of bacteria and fungus of clinical origin,” Molecules, vol. 14, no. 2, pp. 586–597, 2009.
- S. Bonjar, “Evaluation of antibacterial properties of some medicinal plants used in Iran,” Journal of Ethnopharmacology, vol. 94, no. 2-3, pp. 301–305, 2004.
- B. Islam, S. N. Khan, I. Haque, M. Alam, M. Mushfiq, and A. U. Khan, “Novel anti-adherence activity of mulberry leaves: inhibition of Streptococcus mutans biofilm by 1-deoxynojirimycin isolated from Morus alba,” Journal of Antimicrobial Chemotherapy, vol. 62, no. 4, pp. 751–757, 2008.
- A. Z. Almagboul, A. K. Bashir, A. Farouk, and A. K. M. Salih, “Antimicrobial activity of certain Sudanese plants used in folkloric medicine. Screening for antibacterial activity (IV),” Fitoterapia, vol. 56, no. 6, pp. 331–337, 1985.
- M. Sousa, C. Pinheiro, M. E. O. Matos, et al., Constituintes Químicos de Plantas Medicinais Brasileiras, pp. 385–388, Universidade Federal do Ceará, Fortaleza, Brazil, 1991.
- N. Artizzu, L. Bonsignore, F. Cottiglia, and G. Loy, “Studies on the diuretic and antimicrobial activity of Cynodon dactylon essential oil,” Fitoterapia, vol. 66, no. 2, pp. 174–176, 1995.
- E. E. S. Schapoval, S. M. Silveira, M. L. Miranda, C. B. Alice, and A. T. Henriques, “Evaluation of some pharmacological activities of Eugenia uniflora L.,” Journal of Ethnopharmacology, vol. 44, no. 3, pp. 136–142, 1994.
- M. Ikram and H. Inamul, “Screening of medicinal plants for antimicrobial activities,” Fitoterapia, vol. 55, no. 1, pp. 62–64, 1984.
- M. N. Somchit, I. Reezal, I. Elysha Nur, and A. R. Mutalib, “In vitro antimicrobial activity of ethanol and water extracts of Cassia alata,” Journal of Ethnopharmacology, vol. 84, no. 1, pp. 1–4, 2003.
- V. M. Badillo, “Lista actualizada de las especies de la familia Compuestas (Asteraceae) de Venezuela,” Ernstia, vol. 11, pp. 147–215, 2002.
- B. U. Reddy, “Enumeration of antibacterial activity of few medicinal plants by bioassay method,” E-Journal of Chemistry, vol. 7, no. 4, pp. 1449–1453, 2010.
- A. Ahmad, N. Jahan, A. Wadud, et al., “Physiochemical and biological properties of Adiantum capillus veneris: an important drug of unani system of medicines,” International Journal of Current Research and Review, vol. 4, no. 21, pp. 70–75, 2012.
- A. V. Krishnaraju, T. V. N. Rao, D. Sundararaju, et al., “Assessment of bioactivity of Indian medicinal plants using Brine shrimp (Artemiasalina) lethality assay,” International Journal of Applied Science and Engineering, vol. 3, no. 2, pp. 125–134, 2005.
- R. Ansari and K. Ekhlasi-Kazaj, “Adiantum capillus-veneris. L: phytochemical constituents, traditional uses and pharmacological properties: a review,” Journal of Advanced Research, vol. 3, no. 4, pp. 15–20, 2012.
- S. Shalini and P. Sampathkumar, “Phytochemical screening and antimicrobial activity of plant extracts for disease management,” International Journal of Current Science, pp. 209–218, 2012.
- D. H. S. Gracelin, A. D. J. Britto, and P. B. J. R. Kumar, “Antibacterial screening of a few medicinal ferns against antibiotic resistant phytopathogen,” International Journal of Pharmaceutical Sciences and Research, vol. 3, no. 3, pp. 868–873, 2012.
- R. J. P. Cannell, “How to approach the isolation of a natural product,” Natural Products Isolation Methods in Biotechnology, vol. 4, pp. 1–52, 1990.
- D. Premnath, J. V. Priya, S. E. Ebilin, and G. M. Patric, “Antifungal and anti bacterial activities of chemical constituents from Heliotropium indicum Linn. Plant,” Drug Invention Today, vol. 4, no. 11, pp. 564–568, 2012.
- M. Ashutosh, P. D. Kumar, M. M. Ranjan, et al., “Phytochemical screening of Ichnocarpus Frutescens plant parts,” International Journal of Pharmacognosy and Phytochemical Research, vol. 1, no. 1, pp. 5–7, 2009.
- S. Singh, S. Khatoon, H. Singh, et al., “A report on pharmacognostical evaluation of four Adiantum species, Pteridophyta, for their authentication and quality control,” Revista Brasileira de Farmacognosia, vol. 23, no. 2, 2013.
- S. A. Kayani, A. Masood, A. K. K. Achakzai, and S. Anbreen, “Distribution of secondary metabolites in plants of Quetta-Balochistan,” Pakistan Journal of Botany, vol. 39, no. 4, pp. 1173–1179, 2007.
- A. M. Khan, R. A. Qureshi, F. Ullah et al., “Phytochemical analysis of selected medicinal plants of Margalla hills and surroundings,” Journal of Medicinal Plant Research, vol. 5, no. 25, pp. 6017–6023, 2011.
- G. A. Ayoola, H. Coker, S. A. Adesegun, et al., “Phytochemical screening and antioxidant activities of some selected medicinal plants used for malaria therapy in South Western Nigeria,” Tropical Journal of Pharmaceutical Research, vol. 7, no. 3, pp. 1019–1024, 2008.
- H. Liu, S. Sun, L. Guang-Hua, and K. C. Kelvin, “Study on Angelica and its different extracts by Fourier transform infrared spectroscopy and two-dimensional correlation IR spectroscopy,” Spectrochimica Acta A, vol. 64, no. 2, pp. 321–326, 2006.
- M. Meenambal, K. Pughalendy, C. Vasantharaja, et al., “Phytochemical information from FTIR and GC-MS studies of methol extract of Delonix elat leaves,” International Journal of Chemical and Analytical Science, vol. 3, no. 6, pp. 1446–1448, 2012.
- J. G. Collee and W. Marr, “Specimen collection, culture containers and media,” in Mackie & McCartney, Practical Medical Microbiology, pp. 95–111, Charchill Living Stone, New York, NY, USA, 14th edition, 1996.
- G. C. Ainsworth, F. K. Sparrow, and A. C. Sussman, The Fungi. An Advanced Treatise, vol. 4 of A Taxonomic Review with Keys, Academic Press, London, UK, 1973.
- P. I. Ushimaru, M. T. N. da Silva, L. C. di Stasi, L. Barbosa, and A. Fernandes Jr., “Antibacterial activity of medicinal plant extracts,” Brazilian Journal of Microbiology, vol. 38, no. 4, pp. 717–719, 2007.
- D. Janovska, K. Kubikova, and L. Kokoska, “Screening for antimicrobial activity of some medicinal plants species of traditional Chinese medicine,” Czech Journal of Food Sciences, vol. 21, no. 3, pp. 107–110, 2003.
- A. T. Mbaveng, B. Ngameni, V. Kuete et al., “Antimicrobial activity of the crude extracts and five flavonoids from the twigs of Dorstenia barteri (Moraceae),” Journal of Ethnopharmacology, vol. 116, no. 3, pp. 483–489, 2008.
- N. S. Rajurkar and K. Gaikwad, “Evaluation of phytochemicals, antioxidant activity and elemental content of Adiantum capillus veneris leaves,” Journal of Chemical and Pharmaceutical Research, vol. 4, no. 1, pp. 365–374, 2012.
- T. Nakane, Y. Maeda, H. Ebihara et al., “Fern constituents: triterpenoids from Adiantum capillus-veneris,” Chemical and Pharmaceutical Bulletin, vol. 50, no. 9, pp. 1273–1275, 2002.
- D. Shaikh, S. A. H. Zaidy, K. Shaikh, et al., “Post surgical wound infections: a study on threats of emerging resistance,” Pakistan Journal Of Pharmacology, vol. 20, no. 1, pp. 31–41, 2003.
- F. Biadglegne, B. Abera, A. Alem, and B. Anagaw, “Bacterial isolates from wound infection and their antimicrobial susceptibility pattern in Felege Hiwot Referral Hospital, North West Ethiopia,” Ethiopian Journal of Health Sciences, vol. 19, pp. 173–177, 2009.
- B. Thapa, D. Karn, and K. Mahat, “Emerging trends of nosocomial Citrobacter species surgical wound infection: concern for infection control,” Nepal Journal of Dermatology, Venereology and Leprology, vol. 9, no. 1, pp. 10–14, 2010.
- A. Hannan, M. U. Qamar, M. Usman, et al., “Multidrug resistant microorganisms causing neonatal septicemia: in a tertiary care hospital Lahore, Pakistan,” African Journal of Microbiology Research, vol. 7, no. 19, pp. 1896–1902, 2013.
- M. Tumbarello, R. Citton, T. Spanu et al., “ESBL-producing multidrug-resistant Providencia stuartii infections in a university hospital,” Journal of Antimicrobial Chemotherapy, vol. 53, no. 2, pp. 277–282, 2004.
- E. Amaya, D. Reyes, S. Vilchez et al., “Antibiotic resistance patterns of intestinal Escherichia coli isolates from Nicaraguan children,” Journal of Medical Microbiology, vol. 60, no. 2, pp. 216–222, 2011.
- K. Shimizu, T. Kumada, and W.-C. Hsieh, “Comparison of aminoglycoside resistance patterns in Japan, Formosa, and Korea, Chile, and the United States,” Antimicrobial Agents and Chemotherapy, vol. 28, no. 2, pp. 282–288, 1985.
- S. H. Mirza, N. J. Beeching, and C. A. Hart, “The prevalence and clinical features of multi-drug resistant Salmonella typhi infections in Baluchistan, Pakistan,” Annals of Tropical Medicine and Parasitology, vol. 89, no. 5, pp. 515–519, 1995.
- A. Mahboubi, M. Kamalinejad, M. Shalviri, et al., “Evaluation of antibacterial activity of three Iranian medicinal plants,” African Journal of Microbiology Research, vol. 6, no. 9, pp. 2048–2052, 2012.
- P. Parihar, L. Parihar, and A. Bohra, “In vitro antibacterial activity of fronds (leaves) of some important pteridophtes,” Journal of Microbiology and Antimicrobials, vol. 2, no. 2, pp. 19–22, 2010.
- I. Bukhari, M. Hassan, F. M. Abassi, et al., “Antibacterial spectrum of traditionally used medicinal plants of Hazara, Pakistan,” African Journal of Biotechnology, vol. 11, no. 33, pp. 8404–8406, 2012.
- M. Singh, N. Singh, P. B. Khare, and A. K. S. Rawat, “Antimicrobial activity of some important Adiantum species used traditionally in indigenous systems of medicine,” Journal of Ethnopharmacology, vol. 115, no. 2, pp. 327–329, 2008.