Multidrug Resistant Salmonella enterica Strains in South Western Nigeria: Prevalence and Susceptibility to Ceftriaxone

Aims: To investigate the prevalence and susceptibility pattern Salmonella enterica strains to ceftriaxone in southwestern Nigeria. Place and Duration of Study: Faculty of Pharmacy, University of Ibadan, Nigeria from November 2012-May 2013. Methodology: Isolates of Salmonella enterica were characterized by established standard cultural and biochemical tests and was screened in-vitro for their sensitivity to different antibiotics (ampicillin, amoxicillin, chloramphenicol, cotrimoxazole and ceftriaxone) using the agar well diffusion method and their MICs determined. Results:  The  susceptibility  pattern  of  these  strains  to  ceftriaxone  and  other  antibiotics  was examined  to  determine  their  prevalence  among  patients  in  South  West  Nigeria.  21  clinical  isolates were  screened  in-vitro  against  five  antibiotics.  A  higher  number  of  the  isolates  showed  MDR (76.19%)  even  at  higher  concentration  of  the  antibiotics,  while  61.9%  were  sensitive  to  ceftriaxone. Among  the  isolates,  71.43%  resistance  was  recorded  against  ampicillin,  66.67%  against amoxicillin,  38.1%  resistance  against  ceftriaxone,  80.95%  resistance  against  chloramphenicol  and 57.14%  resistance  against  cotrimoxazole.  However,  3  isolates  (14.29%)  were  completely  sensitive to  all  of  the  antibiotics.  The  MICs  obtained  were  higher  (ranging  from  30µg/ml  to  >100µg/ml), compared  to  the  CSLI  breakpoint  standard.  The  result  obtained  showed  an  increased  in  incidence of  MDR  S.  enterica  strain  in  southwestern  Nigeria,  and  that  ceftriaxone  is  still  remain  the  drug  of choice  against  Salmonella  enterica  strains,  even  though  the  number  of  isolates  producing resistance  against  the  antibiotics  is  on  the  increase. Conclusion:  The  results  above  proces  that  the  rate  and  prevalence  of  MDR  Salmonella  enterica strains  are  of  major  concern  mostly  in  developing  countries,  therefore  clinicians  and  public  health practitioners  should  reduce  the  rate  of  antibiotic  prescriptions  and  encourage  public  health  and personal  hygiene  to  prevent  S.  enterica  infection