Introduction
The most common skin condition seen in dermatological OPDs is Pyoderma. Pyoderma are purulent infections of skin and its appendages mainly caused by pyogenic bacteria such as staphylococcus aureus, streptococcus species, CoNS, Enterococus, and gram negative bacteria such as E.coli, Klebsiella and pseudomonas.1
Primary pyoderma is involvement of normal skin and its infection by pyogenic bacteria directly affecting the normal tissue, whereas secondary pyoderma is involvement of skin with a condition predispoding to infection. Primary pyoderma is of various types such as impetigo, carbuncle, furuncle, folliculitis, cellulitis, and other purulent conditions of skin.1, 2
Malnutrition, poor hygiene, overcrowding, poor socioeconomic status, obesity, immunosuppressive conditions such as diabetes mellitus, malignancies, may increase the risk for pyoderma infection in developing countries.2, 3
With emergence of drug resistant bacteria and changing in antibiotic sensitivity pattern it has become a challenge to the clinician to treat pyoderma without proper microbiological reports. The rampant use of antibiotics both topical and systemic and lack of proper antibiotic policies at hospital level lead to the development of drug resistance globally.4, 5
Present study was conducted to know the bacteriological profile of pyoderma in this region and to determine its antibiotic sensitivity pattern along with special reference to MRSA.
Materials and Methods6, 7
A Retrospective study was conducted for a period of one year starting from June 2018 to May 2019 in a tertiary care hospital attached to MR Medical College, Kalaburagi in North Karnataka. Present study was conducted by Dept of Microbiology and Skin and VD dept Of MR medical college. Total samples collected were from 315 clinically diagnosed cases of pyoderma.
Inclusion criteria
All the patients attending the Skin and VD OPD with complaints of purulent skin infection were enrolled in the study after taking written consent from patient or attenders if the patient is minor.
Exclusion criteria
All the patients with non purulent skin lesion, insect bite, patients already on antibiotic therapy.
Specimen collection
Two sterile swabs were collected from clinically diagnosed case after cleaning the area with normal saline. In case of purulent lesions intact, pus was collected on the two sterile swabs after pricking the purulent lesion with sterile needle. The swabs were transported to the microbiology laboratory immediately within 15-30min.
One of the swabs was used for direct grams stain and other swab for inoculation on sheep blood agar and MacConkey agar, both plates incubated at 370c for 24-28hrs. The colony morphology was studied and was subjected to battery of biochemical tests based on repeat gram staining for identification to species level.
Antibiotic sensitivity testing of isolates was done by modified Kirby Bauer’s disc diffusion testing using 0.5 McFarland’s standard as per CLSI guidelines. HiMedia antibiotic discs used for gram positive cocci included, Penicillin(10units), gentamicin (10 µg), amikacin (30µg),ciprofloxacin (5 µg), cefazolin(30 µg), cefuroxime(30 µg),erythromycin (15 µg), co-trimoxazole (25 µg), tetracycline(30 µg), and vancomycin (30 µg), clindamycin (2 µg) and the antibiotics discs used for gram negative bacilli included Ampicillin (10 µg), gentamicin (10 µg), amikacin (30 µg), ciprofloxacin (5 µg), piperacillin(100 µg), ceftazidime(30µg), ceftazidime + clavulanic acid(30 + 10 µg), piperacillin+ tazobactam (100+10 µg), co-trimoxazole (1.25+23.75 µg),tetracycline(30 µg), imipenem (10 µg). MRSA was detected using Cefoxitin disc method.
Results
Total of 315 cases diagnosed as pyoderma clinically were included in the study. Of 315 cases, 295 were culture positive and 20 culture negatives. (Table 1)
Table 1
|
Total number of clinically diagnosed cases pyoderma |
Culture positive |
Culture negative |
|
315 |
295 |
20 |
Around 59% of pyoderma cases were primary and 41% cases were secondary to contact dermatitis, scabies, skin ulcers & eczema.
Impetigo found to be the most common type followed by furunculosis, folliculitis, ecthyma and carbuncle.
Table 2
Primary and secondary pyoderma
The incidence of pyoderma in Males is higher than females with ratio of 1.56:1.
Pyoderma is found all age groups mainly affecting 11-30 yrs age group constituting 45% of cases.
Table 4
Age wise distribution of cases
|
Age group |
Numbers of cases |
Percentage (%) |
|
Less than 10yrs |
35 |
11.1 |
|
11-20yrs |
76 |
24.1 |
|
21-30yrs |
66 |
20.9 |
|
31-40yes |
53 |
16.8 |
|
41-50yrs |
45 |
14.2 |
|
51-60yrs |
21 |
6.6 |
|
61-70yrs |
14 |
4.4 |
|
Above 70yrs |
5 |
1.5 |
|
Total |
315 |
|
The major associated risk factors for causation of Pyoderma was Malnutrition (35%) followed by Diabetes (16.5%), Hypertension (6.3%) & multiple comorbidities found in 12.6% of cases. However, in 94 cases (30%) no associated risk factors were detected.
Table 5
Distribution of cases with respect to co morbidities
|
Co morbidities |
Number of cases |
Percentage |
|
1. Malnutrition |
109 |
34.6% |
|
2. Diabetes |
52 |
16.5% |
|
3. Hypertension |
20 |
6.3% |
|
4. Multiple co morbidities |
40 |
12.6% |
|
5. None |
94 |
29.8% |
|
Total |
315 |
|
Staphylococcus aureus was found to be the most common cause of Pyoderma followed by CoNS and streptococcus pyogenes in gram positive bacteria.
In gram negative bacteria E. Coli is most common followed by Klebsiella pneumoniae, pseudomonas aeruginosa & citrobacter species.
Table 6
Bacteriological profile of isolated bacteria
Antibiotic sensitivity pattern of staphylococcus aureus was analysed to find the Penicillin G as the least resistant and Linezolid & Vancomycin as completely sensitive for all isolates.
Table 7
Antibiotic sensitivity pattern of Staphylococcus aureus
Out of 195 Staphylococcus aureus isolated 23(11.7%) were Methicillin Resistant Staphylococcus Aureus (MRSA) by cefoxitin disc method.
Discussion
Present study was conducted for period of one year at hospital attached to MR Medical college, Kalaburagi in north Karnataka to study the bacteriological profile of pyoderma with its antibiogram.
Out of total 315 cases of pyoderma, Primary Pyoderma cases were 186(59%) and secondary pyoderma cases were 129(41%) which was in accordance with the study conducted by Shanker Venkatesh BM et al.8 and Paudel et al.9 North Karnataka being a region with extremes of temperature, low socioeconomic status and overcrowded places may be reason for more secondary infections causing secondary pyoderma.
According to our study there was male preponderance with 60.96% compared to females with 39.04% and with Male to female ratio 1.56:1 which was in accordance with the study done by Shanker Venkatesh BM et al.8 Ghadage DP et al,10 Paudel et al.9 This could be due to comparatively more exposure and outdoor physical activities in males compared to females.
The most common age group seen in this study was 11 to 20yrs and 21 to 30 years which is in line with other studies such as Hulmani M et al.,11 Ashokan C et al.,12 Ruturaj M K et al,13 and Nipa Singh et al.11
Co-morbidities in the present study were found in 221 cases, Malnutrition being most common followed by diabetes which was comparable with study done by Singh A et al14 and Nipa Singh et al.11 Hypertension was found in 20 cases only, but may not be associated directly in causing the pyoderma.
Of 315 cases, 295 cases showed growth of bacteria and 20 cases were culture negative. The negative cultures may be attributed to the factors such as inadequate sample or patient may be on antibiotics in near past and unable to recall the history which was also seen in study conducted by Shanker Venkatesh BM et al.8 Overall culture found be positive in 94% of cases making it necessary for all cases of pyoderma.
The most common organism isolated was Staphylococcus aureus 195(66.10%), followed by CoNS 36(12.20%), Streptococcus pyogenes 30(10.16%), Escherichia Coli14(4.74%), Klebsiella pneumoniae 09(3.05%), Pseudomonas aeruginosa 8(2.71%), Citrobacter species 3(1.01%). This finding was in line with studies done by Badabagni P et al,15 Haibati S et al,16 and Nipa Singh et al.11 Gram positive bacteria were etiologic agent in 90% of pyoderma cases.
The antibiotic sensitivity pattern of Staphylococcus aureus with vancomycin and linezolid being 100% sensitive was in accordance with studies such as Ashulmani M et al.,17 Ashokan C et al.,12 Ruturaj M K et al.,13 and Nipa Singh et al.11 Doxycycline and gentamicin sensitivity was found to be more when compared to other studies Singh A et al.14 but in line with Haibati S, 16 Nipa Singh et al. 11 Overall most isolates of S.aureus were sensitive to vancomycin, linezolid, gentamicin, doxycycline and least sensitive to penicillin G.
Out of 195 Staphylococcus aureus isolated 23(11.7%) were MRSA by cefoxitin disc method which was slightly more than Malhotra SK et al.,18 and Nipa Singh et al.11 and not comparable and differs from study done by Jayaraj YM et al.19 with 38.9%.
Conclusion
Pyoderma is an important public health issue and commonly seen in age group of 11-30 years with male preponderance. Staphylococcus aureus is most common organism causing pyoderma. Impetigo was found to be the most commom type followed by furunculosis, folliculitis & ecthyma. Emergence of drug resistant strain such as MRSA is an alarming sign for the community, which in turn demands for strict antibiotics policies which can reduce the incidence of drug resistant organisms in this region.
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