Adhesion and biofilm formation on polystyrene by drinking water-isolated bacteria

Abstract

This study was performed in order to characterize the relationship between adhesion and biofilm formation abilities of drinking water-isolated bacteria (Acinetobacter calcoaceticus, Burkholderia cepacia, Methylobacterium sp., Mycobacterium mucogenicum, Sphingomonas capsulata and Staphylococcus sp.). Adhesion was assessed by two distinct methods: thermodynamic prediction of adhesion potential by quantifying hydrophobicity and the free energy of adhesion; and by microtiter plate assays. Biofilms were developed in microtiter plates for 24, 48 and 72 h. Polystyrene (PS) was used as adhesion substratum. The tested bacteria had negative surface charge and were hydrophilic. PS had negative surface charge and was hydrophobic. The free energy of adhesion between the bacteria and PS was[ 0 mJ/m 2 (thermodynamic unfavorable adhesion). The thermodynamic approach was inappropriate for modelling adhesion of the tested drinking water bacteria, underestimating adhesion to PS. Only three (B. cepacia, Sph. capsulata and Staphylococcus sp.) of the six bacteria were non-adherent to PS. A. calcoaceticus, Methylobacterium sp. and M. mucogenicum were weakly adherent. This adhesion ability was correlated with the biofilm formation ability when comparing with the results of 24 h aged biofilms. Methylobacterium sp. and M. mucogenicum formed large biofilm amounts, regardless the biofilm age. Given time, all the bacteria formed biofilms; even those non-adherents produced large amounts of matured (72 h aged) biofilms. The overall results indicate that initial adhesion did not predict the ability of the tested drinking water-isolated bacteria to form a mature biofilm, suggesting that other events such as phenotypic and genetic switching during biofilm development and the production of extracellular polymeric substances (EPS), may play a significant role on biofilm formation and differentiation. This understanding of the relationship between adhesion and biofilm formation is important for the development of control strategies efficient in the early stages of biofilm development.

Increased Biofilm Formation by Nontypeable Haemophilus influenzae Isolates from Patients with Invasive Disease or Otitis Media versus Strains Recovered from Cases of Respiratory Infections

“…Previous studies used crystal violet staining after 2 h growth to determine the initial adhesion to solid surfaces (33,34). This staining is an established method for quantifying biofilm formation; however, in common with other approaches that involve washing the surface where bacteria adhere, this is a controversial technique for assessing initial adherence (33,35).…”

“…After 4 h growth, NT H. influenzae isolates from OM patients presented higher adherence levels than the other isolates, while NB-CAP isolates showed the lowest level of adhesion. It has been stated that bacterial isolates from different niches can exhibit differences in adhesion patterns (34,39). However, why NT H. influenzae OM isolates should adhere faster than the other isolates remains unresolved.…”

Transmission of Infection by Flexible Gastrointestinal Endoscopy and Bronchoscopy

“…Only one case of Methylobacterium bacteremia in a patient after ERCP and removal of a biliary tract prosthesis has been reported (147). Methylobacterium has a strong biofilm-producing ability and is highly resistant to dehydration, elevated temperatures, and ionizing radiation, which can explain the frequent occurrence and colonization of Methylobacterium in the hospital environment (148,149).…”

Methylobacterium and Its Role in Health Care-Associated Infection

“…According to the literature, Methylobacterium has a strong biofilm-producing ability (28)(29)(30). Simões et al (29) tested the effects of sodium hypochlorite (liquid bleach) on the activity and culturability of Methylobacterium biofilms.…”