Assessment of the efficacy of selected disinfectant formulations against clinical isolates of Staphyloccocus aureus from a tertiary Hospital in Ibadan, Nigeria

Abstract

Background: S. aureus is one of the most common causes of nosocomial infections and can cause a range of illnesses, from minor skin infections to life threatening diseases.
Objective: This study was done to assess the efficacy of some commercially available disinfectants and to determine the antimicrobial susceptibility profile of clinical S. aureus isolates.
Material and Methods: Fifty S. aureus isolates were obtained from the Microbiology unit of the University College Hospital, Ibadan and characterized by standard biochemical tests. The efficacy of the test disinfectant formulations was assessed using standard method. Antimicrobial susceptibility profile of the clinical isolates to commonly prescribed antibiotics was determined by modified Kirby-Bauer method.
Results: Salvon ® was most effective with 100% efficacy both at the manufacturer’s in-use concentration and double. Dettol® showed 76% efficacy at the  manufacturer’s in-use concentration and 100% efficacy when concentration was
doubled. Jik® showed activity only when the manufacturer’s in-use concentration was doubled with 94% efficacy. All the isolates were resistant to Germicide® both at the manufacturer’s in-use concentration and double. The isolates (68%) were observed to be most susceptible to Ofloxacin, 44% susceptibility to Gentamicin, 10% susceptibility to Cefuroxime and Amoxycillin/Clavulanate respectively. Only 4% susceptibility was observed to cloxacillin, and 100% resistance was observed to Erythromycin.
Conclusion: Savlon® was the most effective disinfectant, and Germicide® the least (even at double manufacturer’s inuse concentration). Majority of the isolates (96%) were found to be multidrug resistant.

Keywords: S. aureus, Chemical disinfectants, Manufacturers’ concentration,  Microbial resistance.