Flabbiness and expression wrinkles can be helped by undergoing a face lifting or by implanting subcutaneous tissues of polyurethane or polypropylene threads. Under certain conditions microorganisms can attach themselves to the threads and interact with these surfaces initiating cellular growth. The goal of the present study was to evaluate bacterial attachment to polyurethane and polypropylene threads by means of scanning electron microscopy and microbiological method. The threads were sectioned into segments of 1.0cm in length and inserted, one by one, into separated Falcon tubes (50 mL) containing Mueller Hinton broth (15 mL), with 200µl of the bacterial suspension (10 8 CFU/mL) prepared, and incubated for 1 hour and 30 minutes, at 4, 24, 48, 72 and 120 hour periods. After each incubation period, the coupons were rinsed three times and, inserted, one by one, into 5.0 mL of sterile physiological saline solution, sonicated at 40kHz for 8 minutes and vortexed for 10 seconds. This solution was diluted threefold (1/10 to 1/1000), from dilution the 1/1000 dilution an aliquot of 0.1 mL was plated onto Tryptic Soy agar (TSA). The plates were incubated at 37ºC from 18 to 24h. After the incubation periods, the viable bacteria were counted and the results noted in terms of colony forming units (CFU/ml). The coupons destined for scanning electron microscopy observations were fixed in glutaraldehyde, dehydrated in alcohol series, dried in vacuum centryfuge and metalized with gold. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polyurethane, after 1h and 30 minutes of contact, the results shown 4.0±0.0 CFU/ml, S. epidermidis 4.07±0.1 CFU/ml and P. aeruginosa 5.08±0.14 CFU/ml. After 4-120h the number of viable cells of S. aureus on polyurethane surfaces were 5.49±0,04 CFU/ml, S. epidermidis 4.99±0.07 CFU/ml and P. aeruginosa 6.52±0.03 CFU/ml. A quantitative evaluation was recorded of the growth of S. aureus on the surface of polypropylene after 1h and 30 minutes of contact, the results shown 4.24±0.20 CFU/ml, with S. epidermidis 4.14±0.1 CFU/ml and P. aeruginosa 5.77±0.05 CFU/ml. After 4-120h the number of viable cells of S. aureus on polypropylene surfaces were 5.96±0.07 CFU/ml, S. epidermidis 4.96±0.07 CFU/ml and P. aeruginosa 6.63±0.05 CFU/ml. The number of viable cells of S. aureus, S. epidermidis, P. aeruginosa on polyurethane and polypropylene surfaces were significantly different (p<0.05). A biofilm was observed on both threads (polyurethane and polypropylene) as demonstrated by scanning electron microscopy.
