Introduction
Pyoderma is one of the most common public health concerns. It is the pyogenic infection of skin as a result of exogenous bacterial infection or imbalance between the commensal flora.1 Pyoderma is classified into two main types as primary pyoderma and secondary pyoderma.2 Primary pyoderma is infection of skin or its appendages with formation of pus in a previously non diseased skin whereas secondary pyoderma is pyogenic infection in a previously diseased skin as a secondary manifestation.3 In developing countries; the hot and humid climate, low socioeconomic conditions, lack of hygiene, poor access to water, high interpersonal contact and household overcrowding and certain other pre-existing skin conditions like reactions to insects bites (scabies) play a significant role in aetiology of pyoderma.4, 5
Spontaneous resolution of lesions may be a commonest prognosis expected in pyoderma, however rare complications include, superficial and septic dissemination to deep abscess, cellulitis or Sepsis. Occurrence of Glomerulonephritis and other delayed post-streptococcal complications can be observed in Group A Streptococcal infections.4
Among the causative bacteria, Staphylococcus aureus and Streptococcus pyogenes are two most common agents and many times Gram negative bacilli like Proteus species, Pseudomonas species and Coliforms are also encountered. Changing trends are being noted in the etiological aspects of primary pyoderma and also there is an emergence of drug resistant strains. Types of pyoderma, their causative agents and their antibiotic susceptibility pattern vary from region to region and time to time.1 So the awareness about the regional pattern of antibiotic sensitivity of prevalent bacteria is of utmost importance in the diagnosis, treatment and most importantly to prevent inadvertent and indiscriminate use of antibiotics which would further lead to antimicrobial resistance.3
Hence the present study is undertaken to know the bacterial profile of Community acquired pyoderma and their antibiotic susceptibility pattern with special reference to MRSA and ESBL in our set up using conventional methodology.
Materials and Methods
Exclusion criteria
Pus samples from non pyoderma patients
Pus samples from of clinically diagnosed in patient pyoderma cases
Samples yielding bacterial isolates in mixed culture more than three isolates
Samples yielding no growth even after 48 hours of incubation.
Samples yielding known skin commensal flora with no probable pathogenicity are considered as skin contaminants and excluded from the study.
Samples yielding fungal growth.
Sample collection
Skin around the lesion was sterilized using 70% alcohol. In case of an intact pustular lesion, it was ruptured with a sterile needle and the material was collected. In case of open wounds, lesions were rinsed thoroughly with sterile saline after removing debris and then the material collected using sterile swabs. In crusted lesions, the crust was partially lifted and the specimen collected from underneath. Pus Samples were collected on two sterile swabs and placed in sterile test tubes following proper aseptic precautions and transported to the microbiology laboratory within one hour. 6, 7
Sample processing
Gram stain was done with the first swab. The second swab was inoculated in Chocolate agar and MacConkey agar and incubated at 37°C for 24-48 hours for isolation; further processing was done as per the standard microbiological procedures. The organisms were identified based on colony morphology, microscopy by Gram staining and a set of biochemical reactions. 6 Antibiotic susceptibility tests were performed by Kirby-Bauer disk diffusion method on Mueller Hinton agar using routine antibiotic panel. MRSA was detected by using Cefoxin (30µg) disc, Staphylococcus aureus isolates showing less than 21mm zone of inhibition around Cefoxitin disc were considered Methicillin resistant and ESBL production was detected by phenotypic screening and confirmatory methods as per CLSI guidelines. 8
Permission was taken from the institutional Ethical clearance committee. (BIMS- IEC/152/2020-21)
Results
A total of 150 samples collected from clinically diagnosed pyoderma cases attending Outpatient Departments were included in the study out of which 105 (70%) were primary pyoderma cases and 45 (30%) were secondary pyoderma cases. All the age groups from 0 to 100 years were included in the study, of which the most affected age group was 0 to 10 years (25.33%) followed by 11 to 20 years (18%.) (Table/Image-1) Male to female ratio was 2.57:1. Incidence of pyoderma cases was more common in males as the affected males are 108 (72%) and females are 42 (28%). (Table 1) Out of 150 samples Pseudomonas aeruginosa.
Staphylococcus aureus showed highest resistance towards Penicillin (81.91%) followed by Erythromycin and Ciprofloxacin (55.24%), Amoxicillin-Clavulanic Acid and Ofloxacin (37.14%),
None of the Enterobacteriaeceae were ESBL producers.
Table 1
Age and gender wise distribution of pyoderma cases
Table 2
Bacteriological profile of pyoderma cases
Table 3
Antibiotic resistance pattern of Gram Positive Cocci:
Table 4
Antibiotic resistance pattern of Gram negative bacilli:
Discussion
The present study has studied 150 community acquired pyoderma cases. Bacteriological profile and antibiotic susceptibility testing was done using conventional methods and the results were analysed by comparing with other similar studies conducted across the country.
In the present study majority of the pyoderma cases were reported in the age group of 0 to 10 years (25.33%) this could be due to lack of hygiene among children and increased incidence of injuries. Similar occurrence of pyoderma cases in the early paediatric age group is seen in a study conducted by Nandihal W et al,9 Gandhi S et al 10 and Badabagni P et al.11 Whereas studies conducted by HulmaniM et al,12 showed highest occurrence among 21-30 years of age group and Malhotra et al13 in 31-40 years of age group. However, a study conducted by Singh N et al 14 showed uniform occurrence among the first three decades of age group. Male to female ratio was 2.57:1 in the present study with 72% of males and 28% of females being infected. Similar male preponderance is seen in studies conducted by most of the studies. 9, 10, 11, 12, 13 This can be attributed to males being more involved in increased outdoor physical activities than females as well as males seeking medical attention more than females.
Among the 150 samples received, 70% accounted for primary pyoderma cases and 30% for secondary in the present study. This data is in good correlation with studies conducted by Singh N. et al, 14 Ghadage et al15 and Singh A et al. 15 However in a study conducted by Badabagni et al 11 primary pyoderma accounted for as high as 90% of cases and contrastingly in studies conducted by Malhotra et al, 13 only 19% of the cases are from primary pyoderma.
Among the causative bacteria Staphylococcus aureus was most frequently isolated in the present study accounting for 70% of the isolates followed by Coagulase Negative Staphylococcus (10.67%), Streptococcus Pyogenes (8.67%) and Enterococcus Species (4.67%). S. aureus remains the most frequently isolated causative agent of pyoderma in most of the studies conducted across India.9, 10, 12, 13, 15, 16 though the percentage of S. aureus is comparatively lower in the studies conducted by Nagmoti et al 17 and Badabagni et al11 i.e 45% and 52.33% respectively, still S. aureus remains the most common isolate in their studies too. CoNS (10.67%) found to be the second most commonly isolated organism similar to the studies conducted by Singh N et al 14 (12.5%) and Kalashetti V et al 16 (8%). However in the various other studies 9, 11, 14, 18 -haemolytic streptococci appears to be the second highest isolated organism. Whereas in the present study S. pyogenes remains the third commonest isolate (8.67%) which is in good correlation with studies conducted by Nandihal et al (11%), 9 Singh N et al (9.9%).14
Coming to the antibiotic susceptibility pattern of S. aureus isolates, maximum resistance was expressed against Penicillin (81.91%) which is comparable to the study conducted by Biradar S et al19 and Hulmani M et al,12 however many other studies,20, 21 Penicillin resistance is much higher than the present study. Similarly few studies 12, 22 show relatively lesser resistance to Penicillin. Erythromycin being most commonly used topical antibiotic whose resistance was 55.24% in the present study, which is similar to the studies conducted by Singh N et al 14 and Biradar S et al 19 and contrasting with Studies conducted by Shilpa S H et al, 22 Paudel et al 19 and Badabagni et al 11 where Erythromycin is resistance is much lesser than the present study and Hulmani M et al 12 found more resistance. Similar resistance was expressed against Ciprifloxacin (55.28%) in the present study, which is correlating with the study conducted by Hulmani M et al, 12 Ruturaj et al 21 and Singh N et al 14 but study by Shilpa S H et al, 22 Paudel et al 18 and Badabagni et al 11 showed higher sensitivity towards Ciprofloxacin however, much higher resistance is seen in a study by Singh A et al. 15 Such higher resistance to Erythromycin and Ciprifloxacin could be due to irrational usage of these two antibiotics as they are easy available over the counter and easy to use antibiotics in the community set up. Cotrimoxazole, another important first line oral antibiotic against Community acquired infections is 26.67% of resistance which is comparable with most of the studies, 16, 21, 22 however few other studies 10, 12, 13, 17 show much higher resistance than the present study. Gentamicin (11.43%), commonly used injectable in combination with -lactams and other agents turns out to be the quiet effective antibiotic in the present study similar to the studies conducted by Shilpa S H et al, 22 Singh N et al 14 and Biradar et al 19 however studies conducted by Nandihal W et al, 9 Badab`agni et al11 and Hulmani et al 12 showed much higher resistance than present study. Another commonly used topical agent Clindamycin (06.67%) is also effective antibiotic in the present study similar to the study conducted by Nandihal W et al 9 but in most of the studies. 12, 13, 17 Fortunately the higher antibiotics like, Linezolid, Vancomycin and teicoplanin are 100% sensitive in the present study, it is also shown in most of the similar studies,16, 17 however, Hulmani et al, 12 Singh A et al 15 and Kulkarni et al 23 reported emergence of Linezolid and Vancomycin resistant S. aureus isolates. Present study reports 24.76% of MRSA from pyoderma cases which is similar to the studies conducted by Hulmani M et al, 12 Gandhi S et al 10 and Singh Th N et al24 however studies 9, 11, 13, 14, 18, 21, 23, 25 across the country showed varied occurrence of MRSA causing Pyoderma. Occurrence of MRSA is substantially high among community acquired infections in the present study, which can be attributed to irrational use of over the counter available antibiotics leading to selection pressure among causative agents. Indiscriminate use of antibiotics at the primary health sectors can lead to emergence of such resistance mechanisms at community level.
CoNS (10.67%) being the next frequent isolate in the present study expressed an almost similar resistance pattern as that of S. aureus with a slightly higher rate of Methicillin resistance (33.33%). Antibiotic susceptibility patterns of other isolates are mentioned in Table-3 and Table-4. However as their number of occurrences is considerably low, the results of their Susceptibility could not be generalised.
Limitations
Though the study was conducted over a long period of one and half years the sample size appears to be relatively smaller looking into the proportion of the isolates. Extensive analysis regard to the Gram negative bacilli and their antibiotic susceptibility was not possible as their prevalence was very low.
Conclusion
The present study concludes that, S. aureus is the commonest causative agent of pyoderma cases which are more frequent in early paediatric age groups with male propendarence hence the preventive measures need to be directed towards this age group through primary education. Role of hygiene and attentiveness towards injuries and wounds needs to be stressed up on. Prevalence of MRSA in the present study is 24.76% and Erythromycin and Ciprofloxacin are least effective options against pyoderma infections and other commonly used topical, oral and injectable agents are promising options in treating these infections in the present set up. Study stresses upon systematic surveillance of antimicrobial susceptibility to help in effective management of clinical cases and detection of emergence of drug resistance along with antibiotic policy for empirical therapy of community acquired pyoderma cases.
