Attachment of Bacteria to Soft Contact Lenses Sherry
A.
Fowler, MS; Jack
V.
Greiner, PhD; Mathea R. Allansmith,
\s=b\ A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers and eight patients with contact lens-associated giant papillary conjunctivitis were examined by scanning electron microscopy. Structures that resembled bacteria were present on the anterior surface of seven lenses. All lenses showed a coating of granular mucus-like deposits. Some bacteria were seen scattered randomly over the surface, with no apparent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes, the distal ends of which were unattached. These attached bacteria were cylindrical in shape. Several bacteria showed a constriction centrally. Some bacteria were covered by the surface coating, while others, which were round to ovoid in shape, appeared partially embedded in the coating itself. Aggregations of bacteria were seen around clumps of mucuslike debris.
(Arch Ophthalmol 97:659-660, 1979) a previous study' we noticed bacteria on the anterior surface of several soft contact lenses. These lenses had been worn by either asymptomatic contact lens wearers with normal-appearing conjunctiva or by patients with contact lens-asso¬ ciated giant papillary conjunctivitis.11
Accepted
for publication July 7, 1978. From the Department of Ophthalmology, Harvard Medical School, and the Department of Cornea Research, Eye Research Institute of Retina Foundation, Boston. Reprint requests to Eye Research Institute of Retina Foundation, 20 Staniford St, Boston, MA 02114 (Ms Fowler).
MD
al,3 using scanning electron microscopy, found bacteria on the posterior surface of one of three hydrophilic contact lenses. These bac¬ teria appeared to lie on the lens surface, and it was not clear whether they were otherwise attached to the Matas et
lens surface. The present study uses scanning electron microscopy to investigate the relationship of bacteria to the anterior surface of soft contact lenses. MATERIALS AND METHODS
A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers with normal-appearing conjunctiva and from eight patients with contact lens-associated
giant papillary conjunctivitis were exam¬ ined by means of scanning electron micros¬ copy. Lenses were removed from subjects by using the finger pinch method, touching as little of the lens as possible, and were immediately immersed and fixed in 4% glutaraldehyde solution in 0.15 M sodium phosphate buffer (pH, 7.2) for several hours at room temperature. Lenses were then postfixed in cold 1% osmic acid solu¬ tion in the same buffer for 90 minutes, followed by dehydration in graded ethyl alcohols and drying in a critical point drying apparatus using carbon dioxide as a critical point transitional fluid. Lenses were mounted on aluminum sample stubs and coated with gold (60%)-palladium (40%) in a sputtering device. The anterior lens surface was examined for structures that morphologically resembled bacteria, by use of a scanning electron microscope operated at 40 kV.
electron microscopy. All lenses so examined bore a surface coating of granular deposits, which was believed to be dried mucus debris. Some bacteria were scattered ran¬ domly over the surface, with no appar¬ ent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes (0.1 to 0.2 µ in diameter). The distal end of these structures was free and was unattached to the surface. These cylindrically shaped bacteria had a diameter of 0.3 to 0.4 µ and a length of approximately 2 µ (Fig 1), although several were 3 to 4 µ in length. A slight central constriction divided these longer bacteria into segments that measured approxi¬ mately 1.5 to 2.0 µ. Round to ovoidshaped bacteria, which appeared to be stuck in the surface, measured 0.4 to 0.5 µ in diameter and ranged between 0.4 and 0.7 µ in length (Fig 1). Some bacteria were actually embedded in the surface coating deposits (Fig 2), and aggregations of bacteria were
RESULTS
Structures with the morphologic appearance of bacteria were present on the anterior surface of seven contact lenses examined by scanning
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
Fig 1—Bacteria adherent to surface coat¬ ing of worn contact lens. Bacteria with foot processes (arrows) are attached to granu¬ lated coating (x 1,000). Bar gauge is 1 µ.
not able to determine whether these
immature, but developing cylin¬ 2^-long forms, or if they were some other type of bacteria. were
drical
We believe that lens surface coat¬ to accumulate and attach in the same way that bacteria attach to other mucuscovered, nondesquamating surfaces.7 Bacterial attachment is necessary for persistence and colonization of bacte¬ ria on nondesquamating surfaces.7 Because bacteria are unlikely to proliferate on a surface unless they can attach, and in that we have shown that bacteria do attach to the surface of contact lenses, we suggest that the contact lens provides a surface on which bacteria can proliferate and
ings permit bacteria
s
provide antigenic
mass.
This study was supported by grants EY-00208, EY-01552, and Institutional National Research
in granulated surface coating (lower left corner). Elongated bacterium with central constriction (white arrow). Bacterium with foot processes (black arrow). High magnification of foot process (black-on-white arrow). Unattached, loose bacteria (lower left [ 10,000] ). Bar gauge is 1 µ. Inset, Bacteria aggregated around and stuck into mucus-like debris ( 1,000). Bar gauge is 1 µ.
Fig 2.—Bacterium embedded
gathered around clumps of mucus-like debris (Fig 2, inset). COMMENT
Bacteria were demonstrated on sev¬ en of 25 soft contact lenses examined. It is not known how many lenses originally had bacteria on them. The procedure used for preparation of these lenses for scanning electron microscopy would be likely to break the attachment of bacteria to the lens surface, thereby removing them. The presence of bacteria on contact lens surfaces has been mentioned previously.'"1 Only one group of authors showed pictures to substan¬ tiate their comments. ' The structures reported by Matas et al' were rodshaped and measured 2 to 4 µ in length. Pseudomonas aeruginosa was
cultured from the soaking solution from which this lens was obtained. Scanning electron microscopy of the cultured bacterial colonies demon¬ strated collections of rod-shaped structures, which appeared to be morphologically identical to those seen on the contact lens surface. These bacterial structures were similar if not identical to those seen on the anterior surface of the lenses that we examined. The scanning electron microscopic appearance of long, cylin¬ drical bacteria with foot processes was similar both in length and diameter to the flagellate bacteria shown by Pfister" in a scanning electron micrograph of the rabbit conjunctival surface. As for the round-to-ovoid bacterial structures that appeared to be stuck in the surface coating deposits, we were
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
Service award EY-07018 from the National Eye Institute, National Institutes of Health, and by a
grant from Allergan.
References 1. Fowler SA, Greiner JV, Allansmith MR: The surface of soft contact lenses from patients with giant papillary conjunctivitis. Am J Ophthalmol, to be published. 2. Allansmith MR, Korb DR, Greiner JV, et al: Giant papillary conjunctivitis in contact lens wearers. Am J Ophthalmol 83:697-708, 1977. 3. Matas BR, Spencer WH, Hayes TL: Scanning electron microscopy of hydrophilic contact lenses. Arch Ophthalmol 88:287-295, 1972. 4. Doughman DJ, Mobilia E, Drago D, et al: The nature of "spots" on soft lenses. Ann Ophthalmol 7:345-353, 1975. 5. Maberley AL, Tuffnell PG, Hill JC: Contamination of trial contact lenses. Can J Ophthalmol 5:45-54, 1970. 6. Pfister RR: The normal surface of conjunctival epithelium: A scanning electron microscopic study. Invest Ophthalmol 14:267-279, 1975. 7. Gibbons RJ: Bacterial adherence to mucosal surfaces and its inhibition by secretory antibodies, in Mestecky J, Lawton AR (eds): The Immunoglobulin A System. New York, Plenum Press Inc, 1974, pp 315-325. 8. Tinanoff N, Brady JM, Gross A: The effect of NF and SF2 mouthrinses on bacterial colonization of tooth enamel: TEM and SEM studies. Caries Res 10:415-426, 1976.
A.
Fowler, MS; Jack
V.
Greiner, PhD; Mathea R. Allansmith,
\s=b\ A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers and eight patients with contact lens-associated giant papillary conjunctivitis were examined by scanning electron microscopy. Structures that resembled bacteria were present on the anterior surface of seven lenses. All lenses showed a coating of granular mucus-like deposits. Some bacteria were seen scattered randomly over the surface, with no apparent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes, the distal ends of which were unattached. These attached bacteria were cylindrical in shape. Several bacteria showed a constriction centrally. Some bacteria were covered by the surface coating, while others, which were round to ovoid in shape, appeared partially embedded in the coating itself. Aggregations of bacteria were seen around clumps of mucuslike debris.
(Arch Ophthalmol 97:659-660, 1979) a previous study' we noticed bacteria on the anterior surface of several soft contact lenses. These lenses had been worn by either asymptomatic contact lens wearers with normal-appearing conjunctiva or by patients with contact lens-asso¬ ciated giant papillary conjunctivitis.11
Accepted
for publication July 7, 1978. From the Department of Ophthalmology, Harvard Medical School, and the Department of Cornea Research, Eye Research Institute of Retina Foundation, Boston. Reprint requests to Eye Research Institute of Retina Foundation, 20 Staniford St, Boston, MA 02114 (Ms Fowler).
MD
al,3 using scanning electron microscopy, found bacteria on the posterior surface of one of three hydrophilic contact lenses. These bac¬ teria appeared to lie on the lens surface, and it was not clear whether they were otherwise attached to the Matas et
lens surface. The present study uses scanning electron microscopy to investigate the relationship of bacteria to the anterior surface of soft contact lenses. MATERIALS AND METHODS
A total of 25 soft contact lenses from 17 asymptomatic contact lens wearers with normal-appearing conjunctiva and from eight patients with contact lens-associated
giant papillary conjunctivitis were exam¬ ined by means of scanning electron micros¬ copy. Lenses were removed from subjects by using the finger pinch method, touching as little of the lens as possible, and were immediately immersed and fixed in 4% glutaraldehyde solution in 0.15 M sodium phosphate buffer (pH, 7.2) for several hours at room temperature. Lenses were then postfixed in cold 1% osmic acid solu¬ tion in the same buffer for 90 minutes, followed by dehydration in graded ethyl alcohols and drying in a critical point drying apparatus using carbon dioxide as a critical point transitional fluid. Lenses were mounted on aluminum sample stubs and coated with gold (60%)-palladium (40%) in a sputtering device. The anterior lens surface was examined for structures that morphologically resembled bacteria, by use of a scanning electron microscope operated at 40 kV.
electron microscopy. All lenses so examined bore a surface coating of granular deposits, which was believed to be dried mucus debris. Some bacteria were scattered ran¬ domly over the surface, with no appar¬ ent attachment to the lens, whereas others were attached to the coated surface by thin, flagella-like foot processes (0.1 to 0.2 µ in diameter). The distal end of these structures was free and was unattached to the surface. These cylindrically shaped bacteria had a diameter of 0.3 to 0.4 µ and a length of approximately 2 µ (Fig 1), although several were 3 to 4 µ in length. A slight central constriction divided these longer bacteria into segments that measured approxi¬ mately 1.5 to 2.0 µ. Round to ovoidshaped bacteria, which appeared to be stuck in the surface, measured 0.4 to 0.5 µ in diameter and ranged between 0.4 and 0.7 µ in length (Fig 1). Some bacteria were actually embedded in the surface coating deposits (Fig 2), and aggregations of bacteria were
RESULTS
Structures with the morphologic appearance of bacteria were present on the anterior surface of seven contact lenses examined by scanning
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
Fig 1—Bacteria adherent to surface coat¬ ing of worn contact lens. Bacteria with foot processes (arrows) are attached to granu¬ lated coating (x 1,000). Bar gauge is 1 µ.
not able to determine whether these
immature, but developing cylin¬ 2^-long forms, or if they were some other type of bacteria. were
drical
We believe that lens surface coat¬ to accumulate and attach in the same way that bacteria attach to other mucuscovered, nondesquamating surfaces.7 Bacterial attachment is necessary for persistence and colonization of bacte¬ ria on nondesquamating surfaces.7 Because bacteria are unlikely to proliferate on a surface unless they can attach, and in that we have shown that bacteria do attach to the surface of contact lenses, we suggest that the contact lens provides a surface on which bacteria can proliferate and
ings permit bacteria
s
provide antigenic
mass.
This study was supported by grants EY-00208, EY-01552, and Institutional National Research
in granulated surface coating (lower left corner). Elongated bacterium with central constriction (white arrow). Bacterium with foot processes (black arrow). High magnification of foot process (black-on-white arrow). Unattached, loose bacteria (lower left [ 10,000] ). Bar gauge is 1 µ. Inset, Bacteria aggregated around and stuck into mucus-like debris ( 1,000). Bar gauge is 1 µ.
Fig 2.—Bacterium embedded
gathered around clumps of mucus-like debris (Fig 2, inset). COMMENT
Bacteria were demonstrated on sev¬ en of 25 soft contact lenses examined. It is not known how many lenses originally had bacteria on them. The procedure used for preparation of these lenses for scanning electron microscopy would be likely to break the attachment of bacteria to the lens surface, thereby removing them. The presence of bacteria on contact lens surfaces has been mentioned previously.'"1 Only one group of authors showed pictures to substan¬ tiate their comments. ' The structures reported by Matas et al' were rodshaped and measured 2 to 4 µ in length. Pseudomonas aeruginosa was
cultured from the soaking solution from which this lens was obtained. Scanning electron microscopy of the cultured bacterial colonies demon¬ strated collections of rod-shaped structures, which appeared to be morphologically identical to those seen on the contact lens surface. These bacterial structures were similar if not identical to those seen on the anterior surface of the lenses that we examined. The scanning electron microscopic appearance of long, cylin¬ drical bacteria with foot processes was similar both in length and diameter to the flagellate bacteria shown by Pfister" in a scanning electron micrograph of the rabbit conjunctival surface. As for the round-to-ovoid bacterial structures that appeared to be stuck in the surface coating deposits, we were
Downloaded From: http://archopht.jamanetwork.com/ by a University of Michigan User on 06/16/2015
Service award EY-07018 from the National Eye Institute, National Institutes of Health, and by a
grant from Allergan.
References 1. Fowler SA, Greiner JV, Allansmith MR: The surface of soft contact lenses from patients with giant papillary conjunctivitis. Am J Ophthalmol, to be published. 2. Allansmith MR, Korb DR, Greiner JV, et al: Giant papillary conjunctivitis in contact lens wearers. Am J Ophthalmol 83:697-708, 1977. 3. Matas BR, Spencer WH, Hayes TL: Scanning electron microscopy of hydrophilic contact lenses. Arch Ophthalmol 88:287-295, 1972. 4. Doughman DJ, Mobilia E, Drago D, et al: The nature of "spots" on soft lenses. Ann Ophthalmol 7:345-353, 1975. 5. Maberley AL, Tuffnell PG, Hill JC: Contamination of trial contact lenses. Can J Ophthalmol 5:45-54, 1970. 6. Pfister RR: The normal surface of conjunctival epithelium: A scanning electron microscopic study. Invest Ophthalmol 14:267-279, 1975. 7. Gibbons RJ: Bacterial adherence to mucosal surfaces and its inhibition by secretory antibodies, in Mestecky J, Lawton AR (eds): The Immunoglobulin A System. New York, Plenum Press Inc, 1974, pp 315-325. 8. Tinanoff N, Brady JM, Gross A: The effect of NF and SF2 mouthrinses on bacterial colonization of tooth enamel: TEM and SEM studies. Caries Res 10:415-426, 1976.
