Antibiotic sensitivity profiles of salmonella organisms isolated from presumptive typhoid patients in Zaria, northern Nigeria.

A hundred and ten Salmonella organisms (comprising 38 Salm. typhi, 13 Salm. paratyphi and 59 non-typhi Salmonella spp.) isolated from blood of patients diagnosed of typhoid fever in Zaria, Northern, Nigeria were evaluated for their in-vitro susceptibility to eighteen antibiotics. A high percentage of the Salmonella spp. exhibited resistance to the various test antibiotics. While ceftriaxone, ciprofloxacin and the aminoglycosides exhibited the greatest in-vitro activity against the isolates (82.7-96.4% of the isolates were susceptible), chloramphenicol and the aminopenicilins were considerably less effective (only 54.5% of isolates were sensitive). Multiple antibiotic resistance (MAR) indexing showed that 90.9% of the isolates had multiple drug resistance (MAR) index >0.2. Eighteen of these isolates were resistant to at least 12 of the 18 antibiotics; susceptible only to ceftriaxone, ciprofloxacin and the aminoglycosides. The percentage degree of resistance and MAR indices of the isolates to the antibiotic agents were irrespective of age and gender of the patients. The high prevalence of multiple drug resistant bacteria in this region is of epidemiological concern, as this will restrict the choices of antibiotics in the treatment of typhoid fever to a few compounds.