Money is very important to human life as it facilitates the needs and currency notes are vital for goods and services worldwide. Banknotes are used for every type of commerce from buying milk at local store to buying even drugs. Although, the paper notes of currency which is handled by a large number of people increase the possibility of acting as environmental vehicle for the transmission of potential pathogenic microorganisms i.e., bacteria and fungi.
So, the infected currency is identified as potential public health hazard as
pathogen spread by circulating banknotes. Immunocompromised person stand the
risk of acquiring opportunistic infection, through handling of contaminated
currency. Opportunistic infection can occur when immune system is not function
properly so bacteria and fungi are usually harmful and cause diseases (Bodsworth
et al., 1990; Cheesbrough, 1991; Allen
et al., 1972).
In literature there is a few data obtained from currency notes as result of
microbial contamination. For example in Nigeria Emikpe and
Oyero (2007) identified Entrobacter sp., Staphylococcus sp.,
Citrobacter sp., Klebsiella sp. and Proteus sp. as pathogenic
bacteria resistant to tetracycline and cotrmoxazole and also sensitive to amoxoftine,
gentamicin, nalidixic acid and ofloxacin. In USA, Peter Ender isolated S.
aurous, Klebsiella pneumoniae, Enterobacter sp. and Pseudomonas
sp. with a 72% sample contamination. In India, Venkatesh similarly isolated
S. aurous, Candida sp. and Aspergillus sp. in currency
note samples. In Pakistan, a co-operative study in Microbiology Department of
Karachi University concluded that contacts with contaminated currency notes
could cause diarrhea and urinary tract infection besides skin burn and septicemia
infection. Their research findings emphasized the economic importance of banknotes
as a source of microbial contamination.
In Sudan, there is no any documented data concerning the pathogenic fungi and bacteria which transmitted by currency notes therefore, the objectives of the present research work are to:
whether Sudanese banknotes currency save as barriers for microbial contamination
some environmental pollution due to currency microbial contamination
some control measures to minimize contamination in Sudanese banknote currency
MATERIALS AND METHODS
Survey: Banknotes from different sources such as butchers, vegetable
markets, fish markets and bus passengers were selected. The values of banknotes
were 1, 2, 5, 10 and 20 Sudanese pounds which were collected randomly and put
in sterile polyethylene bags. They were immediately transferred to the microbiology
laboratory of El-Neelain University to apply all microbiological examinations
for the different values of collected banknotes.
Preparation of samples: Values of banknotes were rinsed and soaked separately in normal saline or sterilized distilled water in 250 mL beaker for 24 h.
Inoculation in culture media: Streaking and swabbing were done with washed water using sterile loop and swab and inoculated onto Nutrient Agar (Play House 52, Wash Bary, U K) and Macconkey Agar (SHIV, India) to obtain bacterial isolation for 48 h incubation period at 37°C. While Sabroud Dextrose Agar (Play House 52, Wash Bary, UK) was used for fungal isolation for 1 week at 28°C.
Examination of culture media: Cultures in solid media were visually inspected for growth rate and colony characteristics.
Sub-culturing: Different colonies were sub-cultured on Nutrient Agar and Macconkey Agar and incubated similarly as before.
Identification of bacteria: Identification of bacteria was carried out using different tests as described by Cowan.
Identification of fungi: The growth of fungi on Sabaroud dextrose agar
was examined critically after 1 week using prepared microscope slides. The prepared
specimens were mounted on Lacto phenol cotton blue and identification of the
fungal species was performed with aid of binocular compound microscope (40X)
adopting the techniques used by Bruge et al. (1977).
RESULTS AND DISCUSSION
Microbiological methods which were adopted in this study indicated that various species of bacteria and fungi have been isolated from different Sudanese banknotes. The genera of isolated bacteria are the members of the family Enterobacteriaceae i.e., Citrobacter frendii, Citrobacter koseri, Escherichia coli, Klebsiella ozaeni, Klebsiella pneumoniae, Klebsiella rhinosclrematis, Proteus vulgaris, Shigella flexneria and Shigella dysentery which are shown in Table 1.
The identified gram positive bacteria were Staphylococcus aureus, Staphylococcus
epidermidis, Staphylococcus saprophyticus and spore-forming bacteria
such as Bacillus subtilis, Bacillus pemulus, Bacillus megaterium,
Bacillus firmus, Corynbacterium haemolyticum, C. hafmainaii
and Lactobacillus caserii as shown in Table 2.
Bacteria which isolated from different banknotes and showed high occurrence
were Staphylococcus auraus, E. coli.
tests for identification of grams negative pathogenic bacteria isolated
from some Sudanese currency notes
= positive, R = Red, Y = Yellow, O = Oxidation, F = Fermentation, MR =
Methyl Red, VP = Voges Prosker, KIA = Kliger Iron Agar
tests for identification of grams positive pathogenic bacteria isolated
from some Sudanese currency notes*
- = Negative, + = Positive, R = Red, Y= Yellow, O.f = Oxidative fermentation,
MR = Methyl Red, VP = Voges Proskaur, KIA = Kliger Iron Agar. (s.f) =
of some pathogenic bacteria isolated from some Sudanese currency notes*
= low occurrence, ++ = medium occurrence, +++ = high occurrence
While genera such as Bacillus, Klebsiella, Citrobacter,
Proteus, Shigella were found in a limited colony numbers especially
in banknotes value of 5, 10 and 20 pounds (Table 3).
The most predominant fungal species isolated were Epidermophyton sp. and Saccharomyces sp., those found abundant in banknote values of 1 and 2 Sudanese pounds. While species such as Tinea sp. and Aspergillus sp. were isolated from a very limited numbers of samples. The occurrence of some species such as Microsporum sp. is somewhat negligible and in a limited manner of prevalence with some percentage of <25%. Moreover, some species of the genus Asprgillus sp. are found very low as compared to the other isolated genera of fungi (Table 4).
From the present investigation, it was clearly observed that there is a negative
correlation between value of banknotes decrease and increase in microorganisms
that were found, regardless of the species found. Areas within Khartoum state
are more contaminated with pathogenic fungi and bacteria because it is a capital
city of the country and involve a large population which means more handling
more frequent exchange of currency leading to more contamination. There were
also a large number of pathogenic bacteria and fungi isolated from samples collected
from fish markets. The bacteria isolated belong to Enterobacteriaceae family
and this family is more frequency found in the air (air-borne) and was found
also in large quantity in faces. This reflects that faucal pollution appears
as a result of poor hygienic attitude in the community. Moreover, the genera
of Enterobacteriaceae are usually hazardous such as Salmonella typhi and
Shigella dysentery that are pathogenic to human and animals.
of pathogenic fungi isolated from some Sudanese currency notes*
+= low occurrence, ++ = medium occurrence, +++ = high occurrence
Furthermore, it was observed that high values of currency are less contaminated
than a low values currency because a low values are more wide spread and exchangeable
between people in population.
The results are closely related and similar to those obtained by Oyero in Nigeria who isolated Enterobacter sp., Staphylococcus sp., Citrobacter sp., Klebsiella sp. and Proteus sp. from different samples of Nigerian currency. Also from this investigation and others, we have reach to the point that Sudanese currency gives a positive appearance of some species of pathogenic bacteria and fungi due to the absence of antimicrobial agent in row material used for manufacture. We also found bacterial contamination in significant number of samples from fish markets which also indicated lack of hygienic attitude.
The results suggest that currency notes may be contaminated especially with bacteria and enteric microbes and may serve as a source of infection. Personal hygiene to reduce the risk of infection is recommended.
Therefore, a recommendation should be pointed out such as awareness of people is how to handle money emphasizing to reduce their hand contamination so reducing currency pollution; emphasis is to be stressed in the handling of banknotes by children so as to keep them safe from infectious diseases because they may enter all type of currency on their mouth; to develop banknotes manufacture by adding antimicrobial agents as a row material during processing; Re-sterilization of currency when it is dirty and return it back to reduce the risk of infection especially for children; plastic banknotes are strongly recommended and coin currency is sometimes needed.