Comparison of adherence ability of bacteria on the surface of rigid gas-permeable contact lens made with different materials / 中华实验眼科杂志

ABSTRACT

Background Wearing contaclenincreasethe risk of infection of the cornea.Some studieshowed the gas-permeability of materialused foconstructing corneal contaclenione of the contributing factorrelated to corneal health.Objective Thistudy wato observe the in vitro adherence ability of differenbacterito rigid gas-permeable contaclense(RGP-CL) made with varioumaterials.MethodContaclensemade with hexafocon,enflufocon opolymethyl methacrylate (PMMA) were placed into Staphylococcuaureus,Staphylococcuepidermidis,oPseudomonaaeruginosbacterial suspension(0.5 MCF) fo24 hours.The strength of bacterial adherence watested and studied by the methyl thiazolyl tetrazolium (MTT) colorimetrimethod based on absorbance (value),and the vortex method waused to calculate the colony forming units.The bactericlump formation waexamined with scanning electron microscope (SEM).ResultMTcolorimetrimethod showed thathe adherence ability of Staphylococcuaureuto hexafocon (value) wasignificantly lowethan thato enflufocon and PMMA,respectively (q=7.379,8.207,P＜0.01),buno significandifference wafound in the adherence ability of Staphylococcuaureubetween enflufocon and PMM(q =0.828,P＞0.05).The adherence ability of Staphylococcuepidermidito XO and enflufocon walowethan thato PMM(q =14.000,12.800,P＜0.01),buno significandifference wafound between the adherence of Staphylococcuepidermidito hexafocon and enflufocon material (q =1.200,P＞0.05).There wano significandifference in the adherence ability of Pseudomonaaeruginosto all three material(F=2.155,P=0.138).The vortex method presented the colony forming unitof Staphylococcuaureuto hexafocon,enflufocon and PMMwith (37.9± 1.5)×106,(49.9±2.2)×106 and (67.4± 1.6)×106,respectively,with significandifference among them (F =206.240,P＜0.01),showing the lowesvalue in hexafocon,the highesvalue in PMMand middle value in enflufocon (q=11.650,28.640,16.990,P＜0.01),Moreover,colony forming uniof Staphylococcuepidermidito hexafocon,enflufocon and PMMwa(7.9 ± 1.3) × 106,(10.5 ± 1.5) × 106,(11.2 ±1.2) × 106,respectively.And thaof hexafocon walowethan one of the PMMmaterial (q =5.060,P＜0.05).No significandifference wafound between hexafocon and enflufocon nobetween hexafocon and PMM(q =3.290,1.770,P＞0.05).In addition,the resultthacorresponded to the vortex method were seen in the MTcolorimetriassay (F =0.232,P =0.799).SEM examination showed dispersed population of Staphylococcuaureuand Staphylococcuepidermidion the surfaceof hexafocon and enflufocon;while much more Staphylococcuaureuand Staphylococcuepidermidiadhered on the surface of PMMA,forming net-like appearance.Conversely,high numbeof Pseudomonaaeruginoswaseen on the surface of all three materials,withounoticeable differencein the bacterial shape and quantity on each of the material.ConclusionThe adherence ability of bacterito PMMistrongethan thaof hexafocon and enflufocon,and gas-permeable material of RGP-CL doenoimpacthe adherence ability of bacteria.