Ability of staphylococcus spp. Isolated from meningitis patients to biofilm formation

Abstract

A total 248 clinical samples of cerebrospinal fluid (CSF) were collected from meningitis patients, for the period of July to October 2018 from the Child Protection Teaching Hospital in the Medical City Compound in Baghdad. All isolates were identification depending on macroscopic, microscopic, biochemical tests and definite with Vitek-2 compact system. The results showed a growth in 42 samples. Sixteen isolates of Staphylococcus spp. were obtained from samples. The number (percentage) of isolates according to species as follow: 7/16) 44%) of S. epidermidis, 3/16 (19%) of S. hominis, 3/16) 19%) of S. haemolyticus, 2/16 (12%) of S. aureus, 1/16 (6%) of S.warneri. These isolates were tested for ability to biofilm formation by using Luria Broth and Tryptone Soya Broth (TSB) supplemented with 0.25% and 2% glucose. The ability of the isolates to form biofilm with Luria Broth, for S.epidermidis, S. aureus, S. haemolyticus, S.hominis and S. warneri were 7/7 (100%), 1/2 (50%), 2/3 (66.66%), 1/3 (33.33%),1/1 (100%) respectively not forming biofilm.As for using a TSB supplemented with 0.25% glucose, S.epidermidis, S. aureus, S. haemolyticus and S.hominis were 6/7 (85.71%), 2/2 (100%), 2/3 (66.66%) and 3/3 (100%) respectively were weakly biofilm formed and when using TSB supplemented with 2% glucose, showed that all Staphylococcus spp. (100%) were positive for the test. The study showed the effect of minimum inhibition concentration(8 μg/ mL) and minimum bactericidal concentrationand (16μg/mL) of Erythromycin on biofilm of Staphylococcus spp. Staphylococcus spp. isolated from CSF showed weak ability to biofilm formation and depending on the host content of sugars . This study showed also weak biofilm forming of Staphylococcus spp. was resistence to erythromosin.