Common mistletoe is a vascular plant belonging to the genus Viscum in the Viscaceae family according to the latest classifications, which in turn belongs to the order of Moslems. Its diameter ranges between 25 and 50 cm and may reach 150 cm.  It has many medicinal benefits. The aqueous extracts of European mistletoe have been widely used for decades in alternative therapy, especially in Germany, Austria and Switzerland [1].  Due to its medical importance, it was used in this study to determine the extent to which it inhibits the growth of some Pathogenic bacterial species, including Klebsiella pneumoniae, and this type represents about 95% of clinical isolates of the genus Klebsiella.  Klebsiella pneumoniae is a major cause of community-acquired bacterial lung diseases and causes acute pneumonia, bronchitis, otitis, some types of croup, wounds, and meningitis [2].  Staphylococcus aureus bacteria were also used, which cause several infections, including wound infections, pustule & boils, impetigo as well as ulcers and infections of wounds and burns [3]. Acinetobacter baumannii may cause a wide range of healthcare-associated infections such as bloodstream infections, ventilator-associated pneumonia, surgical site infections, urinary tract infections, cholangitis, meningitis, peritonitis, skin and wound infections, infective endocarditis and Ventriculitis [4].

This study aims to reveal the effect of the aqueous extract of common mistletoe in inhibiting some bacterial species that cause burns and wounds in human Klebsiella pneumoniae, Staphylococcus aureus and Acinetobacter baumannii which were isolated from wounds and burns.

Isolation and identification of bacteria

Bacterial isolates were identified by studying the general culturing characteristics of the colonies growing on the medium of blood agar, Mannitol salt agar, and Macconkey agar, and then the appearance of colony shapes was studied and determined on the basis of hemolysis type, color, shape, and size,  as  well  as  observing other general characteristics such as utilize of mannitol sugar and growth with a high salt concentration, as well as the use of some biochemical tests such as oxidase and catalase tests, then the diagnosis was confirmed using the Vitec system [5].

Preparation of aqueous extract of common mistletoe

Two extracts of common mistletoe were prepared, one using hot water and the other using cold water, by following methods:-

• 10 gm of common mistletoe was weighed and then placed in a glass beaker, fifty ml of cold water was added, and 10 gm of common mistletoe was also weighed and transferred to another glass beaker, and 50 ml of hot water was added.

• The two extracts were placed in a water bath for 10 minutes and then left for 24 hours.

• The two extracts were precipitated using a centrifuge for 10 minutes and 3000 revolutions per minute, after which the filtered extract was taken while leaving and ignoring the precipitate formed in the tube.

Prepare different concentrations of common mistletoe extract in cold and hot water

Five different concentrations of the aqueous extract of common mistletoe were prepared according to the method of Mitscher and his group [6], which was prepared by adding water to the concentrated common mistletoe solution and we obtained the following five concentrations: 1gm, 0.8mg, 0.6mg, 0.4mg, 0.2 mg. Which then tests the inhibitory activity of the aqueous extract of the common mistletoe plant against isolated types of pathogenic bacteria.

An antimicrobial efficacy test of hot and cold aqueous extract of common mistletoe was conducted against Staphylococcus aureus, Klebsiella pneumoniae and Acinetobacter baumannii isolated from wounds and burns by agar well diffusion method.

The results presented in Table 1 show a high inhibitory activity of the hot aqueous extract against Acinetobacter baumannii and K.pneumoniae as in Figures 1 and 3, depending on the size of the diameters of the inhibition zones. The results showed that the concentration (1gm) is more concentrations were effective towards the bacteria, where the diameter of the inhibition zone was more than 16 mm, except for Staphylococcus aureus. The aqueous extract did not show any effect in inhibiting its growth, as it was characterized by its strong resistance to the extract as shown in Figure 5.

The results of this study differ from the results reached by the researcher Salem, Donia Kamal [7] which indicated the high effectiveness of the aqueous extract of common mistletoe against Staphylococcusaureus [7].  This also does not agree with the results that appeared in our study, while the concentration of 0.8 mg showed intermediate activity against Klebsiella pneumoniae and Acinetobacterbaumannii, and the diameters of the inhibition zones were 12 mm, while the concentration of 0.6 mg also had a medium activity against Acinetobacter.  The diameter of the inhibition zone was 10 mm, and it did not show any activity against Klebsiella pneumoniae and Staphylococcus aureus. The results showed that concentrations of 0.2 mg and 0.4 mg did not show any effectiveness in inhibiting the growth of any type of bacterial isolate.

Table 1: Shows the effectiveness of the hot aqueous extract of common mistletoe against some pathogenic bacterial isolates

Table No. (2) shows the effectiveness of the cold aqueous extract of common mistletoe against some pathogenic bacterial isolates

Figure 1: The inhibition activity of the hot aqueous extract of common mistletoe against Acenitobater bawmanii

 Figure 2: The inhibition activity of the cold aqueous extract of common mistletoe towards Acenitobater bawmanii 

Data

Figure 3: The inhibiting activity of the hot aqueous extract of common mistletoe K.pneumoniae 

Figure 4:  The inhibition activity of cold aqueous extract of common mistletoe against K.pneumoniae 

The results presented in Table 2 show the lack of inhibitory activity of cold aqueous extract of common mistletoe towards any type of bacterial isolates used in the study as in Figures 2, 4 and 6.

In general, it is noted that the effect of medicinal plant compounds on microorganisms varies depending on the plant extract concentrations used and the number of bacteria under examination.  The difference in place and time in the methods of extraction and concentrations of extracts used in each study may have a role in the difference in the effect of single plant extracts in several studies.

Figure 5: The inhibition activity of the hot aqueous extract of common mistletoe against S.aureus 

Figure 6: Shows the inhibition activity of cold aqueous extract of common mistletoe against S.aureus 

1. Zuber, D. “Biological Flora of Central Europe: Viscum Album L.” Flora: Morphology, Distribution, Functional Ecology of Plants, vol. 199, no. 3, 2004, pp. 181–203.

2. Benson. Microbiological Application. 8th ed., McGraw-Hill, 2001.

3. Tille, P.M. Bailey and Scott’s Diagnostic Microbiology. 13th ed., Mosby, an Affiliate of Elsevier, 2014.

4. Shea, O.MK. “Acinetobacter in Modern Warfare.” International Journal of Antimicrobial Agents, vol. 39, no. 5, May 2012, pp. 363–375.

5. Alexander, S.K., et al. Laboratory Exercises in Organisms and Molecular Microbiology. McGraw-Hill, 2004.

6. Mitscher, L.A., et al. “Antimicrobial Agents from Higher Plants 1.” Lioydia, vol. 35, 1972, pp. 157–166.