Bacteriological Study of Pyoderma

Abstract

Two hundred and twenty cases of pyoderma were investigated to study the bacterial aetiology. Folliculitis formed the largest-clinical group followed by infectious eczematoid dermatitis, secondary infection, impetigo, miscellaneous, furuncles and acne in descending order of frequency. A total of 172 micro-organisms were isolated from the infected specimens examined. A single infecting organism was isolated from 65.5% and more than one type of organism from 6.3% of cases. No organism was isolated from 62 (29.2%) cases, Coagulase positive staphylococcus was isolated from 107 (48.6%) beta haemolytic streptococcus from 18 (8.2%) and both these organisms from 11 (5%) cases. Coagulase positive staphylococcus (69.8%) was the predominant species followed by beta haemolytic streptococcus (17.4%), coaplm negative staphylococcus (8.1%) and alpha haemolytic streptococcus (4.7%). The antibiotic resistance pattern showed maximum resistance to ampicillin, penicillin and polymyxin. None of the strains was found to be resistant to cephaloridine, neomycin and kanamycin. Low percentage of strains were found to be resistant to streptomycin, tetracycline, nitrofurazone, erythromycin, chloramphenicol and gentamycin. Of the strains of Staph. aureusphage typed, 35 (43.7%) were not typable, 15 (18.7%) belonged tophage group 111, followed by phage group II, group I and mixed group. The most prevalent phage type in group III was 42E,in group II type 3 C and in the group I type 52A. Multiple antibiotic resistant strains of staph aureus were found mostly in phage groups III and I and not in group 11.