In vitro Staphylococcus epidermidis Growth in Some Viscoelastic Substances Containing Sodium Hyaluronate

Abstract

The aim of our study was to verify the in vitro growth of Staphylococcus epidermidis in various dilutions of some viscoelastic substances containing hyaluronic acid (Healon® and Healon GV, IAL®, Biolon^TM). Serial twofold dilutions of each sterile viscoelastic substance, prepared so as to obtain a final concentration ranging from 50 to 0.78% of the product in sterile saline solution (0.85% NaCl), were taken out with a pipette that delivered 1.0 ml/tube. One hundred microliters of the S. epidermidis inocula, used for the evaluation of the positive control of the test organism, was dispensed into each tube. After 24 h of aerobic incubation at 37 °C, 100 μl of sample was taken out from each tube and plated into the specific medium for the growth of the test organism. After 24 h of incubation at 37 °C, these agar plates were examined and the colony-forming unit count of the test organism was compared to the corresponding total colony count, acting as a positive control, in order to determine the quantitative variation of the test organism grown in the presence of the viscoelastic compounds. For the lowest dilutions (from 1: 2 to 1: 8) statistically significant bacterial growth was detected in all tested viscoelastic substances. For the highest dilutions (1: 64 and 1: 128) Biolon and Healon GV showed a significant inhibition of S. epidermidis growth. A significant inhibition was also observed in the highest dilution (1: 128) of Healon. In every dilution of IAL a statistically significant increase in bacterial growth was observed. It remains to be carefully considered whether S. epidermidis, accidentally penetrating the eye via the intraocular lens, could find a culture medium in a small amount of sodium hyaluronate left in the capsular bag behind the optic.

Endophthalmitis: Pathogenesis, clinical presentation, management, and perspectives

“…However, contaminated agents or surgical equipment used perioperatively may also be a source of infection 43–45. In addition, perioperative variations seem to have some impact on postoperative endophthalmitis rate; different intraocular lens (IOL) materials potentially act as vectors for bacterial spread into the eye11,46,47 and viscoelastic substances, such as sodium hyaluronate, or hydroxypropylmethylcellulose may facilitate transmission of bacteria to the eye 48,49…”

In vitro Viability of External Eye Microbial Flora in Hydroxy-Propyl-Methylcellulose

“…Gallenga et al [15]in their in vitro study demonstrated a significant increase in S. epidermidis growth in different dilutions of viscoelastic substances containing sodium hyaluronate. All the viscoelastics tested showed a similar behavior in the lowest dilutions.…”

“…Because of the capability of P. aeruginosa to provoke endophthalmitis [11, 16, 17, 18, 19]and the slow removal of HPMC [5], an accurate aspiration of HPMC at the end of the operation is advisable. Previous studies [10, 15]showed the ability of various staphylococcal and streptococcal species to grow in some viscoelastic substances containing sodium hyaluronate. The use of viscoelastic substances as carriers for antibiotics has been investigated [21]and may be one of the solutions to the problem of microorganism growth in viscoelastic substances.…”