King Saud University
Saudi Journal of Biological Sciences
Antimicrobial activity of certain bacteria and fungi isolated from soil mixed with human saliva against pathogenic microbes causing dermatological diseases
Huda Mohammed Ahmed Sheikh
Faculty of Science (Girls),Microbiology, K.A.U. Jeddah, Saudi Arabia Received 25 May 2010; revised 8 June 2010; accepted 9 June 2010 Available online 23 June 2010
KEYWORDS Antimicrobial activity; Soil microorganisms; Saliva; Pathogenic microbes; Staphylococcus aureus; MRSA; Aspergillus niger
Abstract Soil samples (collected from El-Madina El-Monawara, Kingdom Saudi Arabia) were mixed with human saliva, incubated inmedia suitable for bacterial and fungal growth and ﬁltered. Eighteen bacterial and ﬁve fungal species were isolated and identiﬁed. The bacterial and fungal ﬁltrates as well as the isolated species were evaluated for their antimicrobial activities against some pathogenic microbes causing dermatological diseases (Staphylococcus aureus, methicillin resistant S. aureus (MRSA) and Aspergillus niger). Thebacterial ﬁltrate showed signiﬁcant antagonistic effect against S. aureus and methicillin resistant S. aureus (MRSA), whereas showed non inhibitory action on the pathogenic fungus. In contrast, the fungal ﬁltrate antagonized the growth of the pathogenic fungus (A. niger) and did not produce any inhibitory effect on the two tested pathogenic bacteria. The isolated bacterial species showeddifferent levels of antagonistic activities against the three tested microbes. Bacillus subtilis was described as potent isolate against the three pathogens, followed by Esherichia coli. However, Bacillus megaterium strongly inhibited the growth of the pathogenic bacteria only. On the other side, all the fungal ﬁltrates of the isolated species, except Cochliobolus lanatus showed antagonistic activityagainst the pathogenic fungus (A. niger). The ﬁltrate of Fusarium oxysporum and Emericella nidulans counteracted the growth of S. aureus, whereas, the growth of MRSA was inhibited only by the ﬁltrate of E. nidulans. From the passage way of our respected prophet, how is never tells from him self, if any person complains from awound or ulcer, the messenger of Allah (prayers and peace be upon him) puthis foreﬁnger on the ground and lift it then he says: (In the Name of God, soil of our land, with the saliva of some of us, our sick person
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H.M. Ahmed Sheikh
will get well after the permission of our God) Al-Bukhari. The meaning of this Hadith that the prophet takes his saliva on the foreﬁnger then he put it on the soil and wipe on the wound place while saying the above Hadith that is shows the Prophet’s miracle, which is evidence of healing by using soil and saliva.
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1. Introduction The dermatological pathogenic microbes could endure in the skin through the cracks, ulcers causing skin infections. The treatment depends on using antibiotics, which have several side effects. The remarkable increase in antibiotics resistant bacterial species (Kina, 2003; Motta et al., 2004) lead to search for new sources of antibiotics through the isolation andidentiﬁcation of new types of microorganisms such as bacteria, fungi and actinomycetes (Alexander, 1982). The antibiotics produced by bacteria have been gaining importance by many investigators. Bacterial species producing antibiotics have been used as biocontrol agents against pathogenic fungi (Yilmaz et al., 2005; Gebree1 et al., 2008). Soil is considered one of the most suitable environments for...