Antibiotic Susceptibilities of Two Multidrug Resistant Acinetobacter Species Clinical Strains Showed Significant Variation to Amoxicillin Resistance and Susceptibilities to Quinolones

Abstract

Acinetobacter species is now considered among the three most important nosocomial bacterial pathogens worldwide. Acinetobacter species possess an inherent capacity to withstand environmental stress and the bacterium pathobiology is complicated with limited therapeutic options available for its treatment due to widespread resistance to antimicrobials of different classes. A total of 75 swabbed surfaces at the nurses’ station paediatric surgical ward ATBUTH were examined for Acinetobacter species and the susceptibility to antibiotics of the isolates investigated.  A low prevalence 2.67% (2/75) was obtained. The isolates were completely resistant to three of the 10 antibiotics tested namely: Chloramphenicol, augmentin (ampicillin + sulbactam) and amoxicillin and wholly susceptible to five of the 10 antibiotics tested: Septrin (sulfamethaxozole + trimethoprim), sparfloxacin, perfloxacin, ofloxacin and streptomycin. The zone of inhibition of the isolates differ significantly with four of the antibiotics tested; ofloxacin (p<0.01), streptomycin (p<0.04), gentamicin (p<0.002) and amoxicillin (p<0.005). The study showed strains of Acinetobacter species even though β-Lactam resistant could vary in the degree of resistance to β-Lactam antibiotics evident with significant difference in zone of inhibitions and high susceptibilities to quinolones antibiotics of the strains. Further work will determine whether strains are clonal and whether the determinant and expression of β-Lactam resistance are the same in those strains background, as well as if the different susceptibilities to β-Lactam as shown by zone of diffusion will translate to different MIC values, and if whether such resistance determinants do not encode quinolone resistance.