International Journal of
Medicine and Medical Sciences

  • Abbreviation: Int. J. Med. Med. Sci.
  • Language: English
  • ISSN: 2006-9723
  • DOI: 10.5897/IJMMS
  • Start Year: 2009
  • Published Articles: 535

Full Length Research Paper

Antimicrobial susceptibility patterns of Staphylococcus aureus in a tertiary referral hospital in Nairobi, Kenya

Christina A. Okello
  • Christina A. Okello
  • Launceston General Hospital, Tasmania, Australia, 280, Charles Street, Tasmania, Australia.
  • Google Scholar
Loice A. Ombajo
  • Loice A. Ombajo
  • Department of Medicine, Mater Hospital, Dunga road, Nairobi, P. O. Box 30325,0100, Kenya,
  • Google Scholar
Enoch Omonge
  • Enoch Omonge
  • Department of Medicine, Mater Hospital, Dunga road, Nairobi, P. O. Box 30325,0100, Kenya,
  • Google Scholar
Frederick C. F. Otieno
  • Frederick C. F. Otieno
  • Department of Medicine, Mater Hospital, Dunga road, Nairobi, P. O. Box 30325,0100, Kenya,
  • Google Scholar
Davies Otieno
  • Davies Otieno
  • Department of Microbiology, Mater Hospital, P. O. Box 30325,00100, Dunga Road, Nairobi, Kenya.
  • Google Scholar
Christina Mwachari
  • Christina Mwachari
  • Nairobi West Hospital, P. O. Box 43375,00100, Nairobi, Kenya.
  • Google Scholar

  •  Received: 03 March 2021
  •  Accepted: 25 October 2021
  •  Published: 30 November 2021


Staphylococcus aureus is a leading cause of hospital and community acquired infections globally. Methicillin-resistant S. aureus (MRSA) prevalence has been reported to be high in various settings and is associated with increased morbidity, mortality and risk of nosocomial outbreaks. Surveillance of prevalence and antibiotic susceptibility patterns is important to ensure appropriate antibiotic prescription. The objective of our study was to establish the prevalence of S. aureus, to identify patterns of susceptibility to commonly used antibiotics and quantify contemporary penicillin resistance among S. aureus. A retrospective study was conducted at the Mater Hospital, Nairobi. The study involved a review of non-duplicate records of specimens analyzed between January 2014 and December 2018. An isolate was categorized as Penicillin susceptible (PSSA) if it was susceptible to Penicillin and Oxacillin, Methicillin susceptible (MSSA) if resistant to Penicillin but susceptible to Oxacillin and Methicillin resistant (MRSA) if resistant to Oxacillin and Penicillin. We present proportions of S. aureus that was PSSA, MSSA and MRSA. Multivariate logistic regression was used to determine the association between the presence of S. aureus isolates and the source of the clinical specimen (inpatient vs. outpatient), age and gender. A total of 659 isolates of S. aureus were analyzed in 5-year period. PSSA was the most prevalent organism seen (60.85%) while MRSA was the least prevalent (0.61%). Most S. aureus were isolated in pus from wound swabs-644 (73. 3%). A significant increase in susceptibility of S. aureus to Penicillin and Amoxicillin-clavulanic acid was observed during the study period. This study demonstrated a high prevalence of Penicillin Sensitive S. aureus and a low prevalence of MRSA.

Key words: Staphylococcus aureus, antimicrobial, penicillin.


SCC mec;  Staphylococcal cassette chromosome mec, MIC; Minimum inhibitory concentration, SSI; Skin and soft tissue infection, MSSA; Methicillin-susceptible Staphylococcus aureus, MRSA; Methicillin-resistant Staphylococcus aureus, CLSI; Clinical and Laboratory Standards Institute, VRSA; Vancomycin Resistant Staphylococcus aureus, OXA; Oxacillin, PEN; Penicillin, VAN;Vancomycin, SXT; Trimethoprim –sulfamethoxazole, GEN;Gentamicin, CLI;Clindamycin, CIP; Ciprofloxacin, LZD; Linezolid, ERY; Erythromycin, TEC; Teicoplanin, FA; Fusidic Acid, TET;Tetracycline, MXF; Moxifloxacin, RIF; Rifampicin.