Current research in microbiology and biotechnology
Current Research in Microbiology and Biotechnology Vol. 3, No. 4 (2015): 690-693 Research Article Open Access
ISSN: 2320-2246
Prevalence and antibiotics sensitivity of
Staphylococcus aureus skin infection in children in
Khartoum, Sudan
Salwa A. Aboud1, Abdallah El-yamani1, Mohamed A. Hussain1,* and Aimun AE. Ahmed2,3
1 Department of pharmaceutical Microbiology, International University of Africa, Sudan. 2 Department of Pharmacology, Faculty of Pharmacy, Omdurman Islamic University, Sudan. 3 Department of Pharmacology, Faculty of Pharmacy, International University of Africa, Sudan. * Corresponding author: Mohamed A. Hussain; e-mail
Received: 02 July 2015 Accepted: 23 July 2015 Online: 30 July 2015
ABSTRACT
Staphylococcus aureus has been reported to cause severe community-associated infections of skin and soft tissues that are especially prevalent in children. Recently S. aureus is increasingly becoming resistant to majority of the available antibiotics in use and subsequently have developed into a challenging public health problem. The aim of this study was to investigate the prevalence and antibiotic sensitivity of S. aureus skin infections in children. Clinical samples (n=212) of Pus and skin swabs were collected from patients enrolled from the out-patient department (OPD) of Khartoum dermatology and venereal teaching hospital over a period of 6 months.
The samples were cultured on bacteriological media for the isolation of S. aureus using standard methods of isolation and identification of bacteria. Antibiotics sensitivity test was carried out using Kirby-Bauer Disk Diffusion Technique in accordance with Clinical and Laboratory Standard Institute (CLSI). 198 (93%) of the total samples showed abundant growth. Of these 150 isolates were identified as S. aureus. The most commonly diagnosed skin infection was impetigo accounting for 61 (30.8%) of the samples of which 48 (78.7%) isolates were S. aureus. Sex differences in the prevalence of S. aureus were not significant whilst age differences were significant. The most effective antimicrobial agent was gentamicin (97.3%) efficacy, then fusidic acid (78%)
efficacy. The sensitivity of the rest antimicrobial agents were erythromycin (50%), amoxy-clav (21.3%) and
bacitracin (12.7%). The present study demonstrated that Staphylococcus aureus are important pathogens in the
context of skin infections. In addition, S. aureus is the main pathogen isolated from Impetigo. S. aureus isolates
showed a very low degree of sensitivity to B-lactam antibiotic and bacitracin indicating the ineffectiveness of
these antibiotics and need to re-assess the policies on antibiotic usage in hospital environment.
Keywords: prevalence, S. aureus, skin infection in children, antibiotic sensitivity, Sudan.
1. INTRODUCTION
There are over 26 species currently recognized in the
S. aureus skin infections were classified as primary or
genus staphylococci [1]. Staphylococcus aureus is by far
secondary [7]. Primary infections were those occurring
the most important and virulent pathogen among the
on apparently normal skin and mainly comprises of
staphylococci [2-3]. S. aureus has been reported to
impetigo, folliculitis, cellulitis and ecthyma. Secondary
cause severe community-associated infections of skin
infections were those arising in damaged skin
and soft tissues [4] that are especially prevalent in
(traumatized skin, or a preexisting skin disease) [8-9].
children [5]. Behavioral factors of children (e.g. the
tendency of children to put hands and objects in their
Impetigo is a common cutaneous infection that is
mouths) as well as their physiologic factors (e.g.
especially prevalent in children. Historically, impetigo
immature immune systems) contribute to the success
is caused by either group A β-hemolytic streptococci or
of pathogen transmission [6].
Salwa A. Aboud et al. / Curr Res Microbiol Biotechnol. 2015, 3(4): 690-693
Staphylococcus aureus. Currently, the most frequently
3. RESULTS AND DISCUSSION
isolated pathogen from impetigo is S. aureus [5].
Out of 212 skin specimens that were collected from
infected children 198 (93%) showed abundant growth
Topical antibiotics are the treatment of choice since
(population pattern is shown in table 1). Of these 150
oral antibiotics have more side effects [10]. Mupirocin
were identified to be S. aureus. Colonial morphology,
and fusidic acid are the first choice options. The
gram stain and biochemical reactions (tube coagulase,
combination of neomycin and bacitracin does not lead
tube catalase and DNAse) were found to be similar to
to bacterial eradication [5] because Bacitracin became
those described by Cheesebrough et al [17].
ineffective. The rise of resistant strains of
Staphylococcal infection has been well documented
According to the report of Pereira (2014), S. aureus is
[11] and clinicians should be cautious not to contribute
the most frequently isolated pathogen from impetigo
to this problem. As Heng et al (2013) concluded in their
[5]. Similarly, Alsterholm (2012), proved that S. aureus
work on antimicrobial resistance, physicians should
was by far the most common bacteria found in cultures
‘prescribe topical fusidic acid discerningly'[12]. If
from skin lesions in impetigo [20]. In this study, the
possible, topical antiseptic preparations should be used
prevalence of impetigo (the commonest diagnosis) was
to treat skin infection. If action is not taken now, the
found to be 78%. This result is in aggreement with
future use of fusidic acid will be compromised [13].'
Alsterholm's report that noted a prevalence of 76-88%
Recent study has lent a voice to the already existing
body of knowledge that S. aureus are increasingly
There were no significant differences in the prevalence
becoming resistant to majority of the available
of S. aureus in males and females (df = 1, P = 0.939) as
antibiotics in use and subsequently have developed
shown in figure 1. Similarly there were no significant
into a challenging public health problem [14-15].
sex differences noted by Farajzadeh et al. at 2008 [21]
Moreover, geographic variation has been found in the
and Alenizi at 2013 [22]. In addition, Hill et al. (2011)
antimicrobial susceptibility patterns of S. aureus [16].
proved that there was no statistical difference between
Hence, continuous local surveillance on antimicrobial
males and females regarding the rate of S. aureus
susceptibility of S. aureus is essential.
colonization [23].
The aim of this study was to determine the prevalence
Age differences in the prevalence of S. aureus was
and antibiotic sensitivity of S. aureus skin infection in
significant (df = 2, P = 0.020) see figure 2. Noting a
higher prevalence in adolescents and infants compared
to children. It is believed that the infants immunity is
not properly developed at this stage to cope up with
2. MATERIALS AND METHODS
bacterial infections hence they are vulnerable and
Clinical samples (n=212) of Pus and skin swabs were
easily infected by ubiquitous bacteria such as S. aureus.
collected from patients enrolled from the outpatient
However in this study, it is not clearly understood why
department (OPD) of Khartoum dermatology and
S. aureus prevalence in adolescents was higher than in
venereal teaching hospital over a period of 6 months.
children. This may be probably due to a significantly
Nutrient agar, Blood agar, Mannitol salt agar, Dnase
smaller sample size in adolescents compared to
agar and Mueller-Hinton agar were prepared according
to manufacturer's instruction (HiMedia Ltd, India), then
used for the isolation of S. aureus using standard
In the present study, antibiotic sensitivity to Fusidic
methods of isolation and identification of the bacteria
Acid was found to be 78%. This result is consistent with
[17]. Antibiotics susceptibility testing was performed
that of Mir et al. (2015) where antibiotic sensitivity to
by Kirby-Bauer disc diffusion method and the
Fusidic Acid was noted to be 79.8% [24]. In this study,
susceptibility to antibiotics was assessed based on the
the antibiotic sensitivity to Erythromycin was found to
Clinical Laboratory Standards Institute (CLSI 2013)
be 50%. This result compares favourably with the
guidelines [18]. The antibiotics tested were Fusidic
published articles from Kenya at 2006, Pakistan at
Acid (10μg), Erythromycin (15μg), Gentamicin (10μg),
2007 and Nigeria at 2011 that reported erythromycin
Amoxiclav (30μg) and Bacitracin (10 units). All
sensitivity of 44.7%, 55.6% and 52.4%, respectively
antibiotic discs were procured from Himedia
[15, 25-26]. However higher percentages of 71.43%
Laboratories Pvt. Ltd. The data was analyzed using a
and 60.6% were reported by two recent published
personal computer and statistical package for social
articles [24, 27] and also lower percentages of 17.2%
sciences (SPSS). Statistical analysis was performed with
[28], 33.3% [21], and 25.64% [22] were noted. This
chi-square test. Significance level was set to be less
than 0.05%, throughout the study analysis. The
microorganisms varies from time to time and from
children were classified according to US FDA [19] into
place to place. In the present study, the antibiotic
four major categories: Neonates: birth to 1 month,
sensitivity to Gentamicin was 97.3%. Although this
Infant: 1 month to 2 years, Children: 2 to 12 years and
result is higher than those of Kaup et al. (2014) [27]
Adolescent: 12 years to <16 years.
and Mir et al. (2015) [24] where Gentamicin sensitivity
was found to be 80.95% and 76.6%, respectively, it was
found to be similar to the report of Onbuwiko et al.
Salwa A. Aboud et al. / Curr Res Microbiol Biotechnol. 2015, 3(4): 690-693
(2011) [15] that noted 92.4% sensitivity. In the present
sensitivity to Amoxyclav was noted to be 21.3% in this
study, the antibiotic sensitivity to Bacitracin was
study. This result was found to be lower than that from
12.7%. This was lower than that of Bashir et al. at 2007
that reported a 25.0% sensitivity [26]. The antibiotic
Figure 1: Bar chart illustrating Sex differences in the prevalence of S. aureus
Figure 2: Differences in the prevalence of S. aureus from different age groups.
Table 1: Population pattern of n=198 by Age, Sex and Diagnosis.
Salwa A. Aboud et al. / Curr Res Microbiol Biotechnol. 2015, 3(4): 690-693
4. CONCLUSION
antimicrobial
resistance.
The present study demonstrated that Staphylococcus
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