ANNALS OF IBADAN POSTGRADUATE MEDICINE
O.L. Okunye1 , P.A. Idowu2 and O.S. Makinde2
Background: Antimicrobial ointments are topical products used for the treatment of common skin infections. Potency superiority between certain ointments and creams used in the treatment of skin infections has been a controversial subject among clinicians. Objective: This study was carried out to investigate the activities of some antimicrobial ointments on selected bacteria and fungi of clinical importance that caused skin infections.
Methods: Three brands of antibacterial; gentamicin, chloramphenicol, bactroban and two brands of antifungal ointments; nystatin and Whitefield’s were evaluated by agar - cup diffusion method for their antimicrobial activity. Minimum inhibitory concentration, minimum bactericidal concentration and minimum fungicidal concentration of the ointments were determined. Kinetic study of bactroban on all the clinical isolates was evaluated to determine their efficacy within a specific time lag.
Results: All the isolates of Pseudomonas aeruginosa were susceptible to bactroban while 4 of the 5 isolates of Streptococcus pyogenes were resistant. Three of the five isolates of Staphylococcus aureus were susceptible to bactroban. Gentamicin had no activity on Pseudomonas aeruginosa while 4 of the 5 isolates of Streptococcus pyogenes were susceptible to gentamicin. Three of the 5 isolates of Staphylococcus aureus were susceptible to gentamicin and varied resistance were recorded for chloramphenicol and antifungal agents. The MIC’’s values recorded for the antimicrobial ointments examined varied with respect to concentrations and composition.
Keywords: Antimicrobial ointments, Skin infection, Microbial agents.
Dr. O.L. Okunye
Dept of Pharmaceutical Micro,
Olabisi Onabanjo University,
The skin is a relatively inhospitable environment for the growth of most pathogenic microorganisms. The hostility of the skin environment is attributed to relative dryness of cutaneous surfaces that provides insufficient amount of moisture that could support significant growth of pathogens and colonization with resident microflora that produces metabolites that are inhibitory to the growth of invading/competing pathogens1 . Eradication of resident flora greatly enhances the survival of Staphylococcus aureus and the subsequent development of infection. Skin infections may be either primary or secondary. Primary infections have characteristic morphologies and courses, and are initiated by single organisms, and usually occur in normal skin. They are most frequently caused by Staphylococcus aureus, Streptococcus pyogenes, and coryneform bacteria. Impetigo, folliculitis, boils, and erythrismal are common examples. Secondary infections originate in diseased skin as a superimposed condition, when the skin is damaged by inflammation, burn or exfoliation, absorption is further increased2 . Pseudomonas aeruginosa is an opportunistic pathogen that can cause skin infection especially in burns and wounds, sores and ulcers often as secondary invaders. Skin lesions have been reported to accompany Pseudomonas aeruginosa sepsis in 13-39 percent of patients studied over the years3. The dermatological manifestations of Pseudomonas aeruginosa include erythema gangrenosum which was however reported in 25% of patients with bacteraemia. Staphylococcus aureus is responsible for variety of infection syndromes that may produce local or diffuse skin lessions by producing toxins (Staphylococcal scalded skin syndrome and toxic shock syndrome due to vascular invasion often in association with carditis4 . Other spectrum skin mediated infections that Staphylococcus aureus can cause include; impetigo, folliculitis, furuncles, and ecthyma. Fungi and yeasts are capable of causing many different forms of skin infections broadly referred to as dermatomycoses. Dermatomycoses are a group of common infections generally caused by Trichophyton species. These infections include tinea capitis, tinea barbae, tinea corporis, tinea pedis and tinea cruris 5,6 Candida albicans that causes vaginitis is manifested by vaginal itching and discharge, often accompanied by dysuria and pain. Pelvic examination may reveal a creamy to cheesy whitish discharge, redness of the vagina wall and external genitalia may also be present7 Antibiotic ointments are topical preparation that are used for the treatment of common skin infections. They contain a medicament dissolved, suspended or emulsified in a base and in their pharmaceutical dosage forms, they are anti-infective and protective on host skin8 . Antimicrobial ointments are used topically for several purposes; as protectants, antiseptics, emollients, antipruritis, keratolytics and astringents. The use of ointments can be an effective part of wound care, along with regularly cleansing the wound in ensuring speedy healing. Ointments are made up of bases which may be hydrocarbon (oleaginous), absorption, water removable and water soluble type9 . In general, ointments are intended to speed healing and prevent infection.