Determination of Antibiogram of Staphylococcus species Isolated from Haemodialysis Patients in Khartoum State

Abstract

This is a laboratory-based study, carried out during the period from March to June, 2015 to determine antibiogram of Staphylococcus species isolated from haemodialysis patients in Khartoum State. A total of 33 bacterial isolates were obtained from the Research Laboratory, Sudan University of Science and Technology. Purity of the isolates was checked by streaking on nutrient agar. Gram´s stain and biochemical tests were used to confirm the identification of the isolates. Modified Kirby-Bauer disc diffusion technique was used to determine antibiogram of the isolates against traditionally used antibiotics. These were Methicillin, Vancomycin, Ciprofloxacin, Ceftriaxone, Trimethoprim-sulphamethazole and Gentamicin. Re-identification of the isolates confirmed that all isolates (n=33) were Staphylococcus species. The species were 4 coagulase positive-staphylococci distributed as 2 (6.1%) S. intermedius, 1 (3%) S. aureus subsp. aureus and 1 (3%) S. lutrae and 29 coagulase-negative staphylococci distributed as 7 (21.2%) S. lugdunensis, 5 (15.2%) S. hemolyticus, 3 (9.1%) S. hominis subsp. novobiosepticus, 2 (6.1%) S. hominis subsp. hominis, 2 (6.1%) S. saprophyticus, 2 (6.1%) S. caprae, 2 (6.1%) S. pasteuri, 1 (3%) S. epidermidis, 1 (3%) S. capitis subsp.urealyticus, 1 (3%) S. schleiferi subsp. schleiferi, 1 (3%) S. piscifermentans , 1 (3%) S. arlettae and 1 (3%) S. vitulinus. Study on antibiogram of the isolates revealed that 11 isolates were resistant to Methicillin and 5 isolates were resistant to Vancomycin. S. aureus was susceptible (100%) to Methicillin, Vancomycin, Ciprofloxacin, Trimethoprim-sulphamethazole and Gentamicin. The susceptibility of coagulase-negative staphylococci to Methicillin, Vancomycin, Ciprofloxacin, Ceftriaxone, Trimethoprim-sulphamethazole and Gentamicin were 69%, 86.2%, 82.8%, 3.5%, 31% and 93% respectively. The study concluded that Staphylococcus species were highly susceptible to Gentamicin (94%), Vancomycin (84.8%) and Ciprofloxacin (84.8%). Low susceptibility of Staphylococcus species were detected against Ceftriaxone (6%). Further studies are required to validate the results of this study.