Inhibitory effects of 2-methacryloyloxyethyl phosphorylcholine polymer on the adherence of bacteria causing upper respiratory tract infection

Abstract

Objective: We aimed to investigate the inhibitory effect of 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer on the adherence of Streptococcus pneumoniae (Spn) and nontypeable Haemophilus influenzae (NTHi) in vitro and in vivo. Materials and Methods: Phosphorylcholine (PC) expression of 21 strains each of Spn and NTHi was evaluated using fluorescence-activated cell sorting; the adherence of bacteria to Detroit 562 cells and to the nasal mucosa of BALB/c mice was determined. MPC polymermediated inhibitory effects were compared with PC-keyhole limpet hemocyanin (PC-KLH)mediated inhibitory effects. Results: In vitro experiments showed that pretreatment with MPC polymer markedly inhibited the adherence of Spn and NTHi in a concentration dose-dependent manner independently of PC expression. No correlation was observed between PC expression and MPC polymermediated inhibitory effects. Contrarily, there was a significant negative correlation between PC-KLH-mediated inhibitory effects and PC expression in Spn and NTHi. The same results were obtained via in vivo experiments. The MPC polymer did not affect the histology of the nasal mucosa. Conclusions: MPC polymer might be effective to reduce the occurrence of upper respiratory tract infection caused by Spn and NTHi and could be applied for the development of local treatments, such as topical gargles and nebulizer medications.

Role of Phosphorylcholine in Streptococcus Pyogenes Adherence to Epithelial Cells

“…High PC expression is considered to increase S. pneumoniae and H. in uenzae virulence [17]. For instance, it has been reported that S. pneumoniae with high PC expression causes more invasive infection than that with low PC expression [18].…”

“…Detroit 562 cells (CCL-138; ATCC, Manassas, VA, USA), a human pharyngeal carcinoma epithelial cell line, were grown to con uence in minimal essential medium (Nacalai Tesque Inc., Kyoto, Japan) supplemented with 1 mM sodium pyruvate (Nacalai Tesque), 10% fetal bovine serum (Invitrogen, San Diego, CA, USA), penicillin (100 U/mL), and streptomycin (100 µg/mL; Nacalai Tesque) at 37°C in a 5% CO 2 incubator, as previously described (Iuchi et al, 2020). The cells were harvested using trypsin ( nal concentration, 0.02%) and ethylenediaminetetraacetic acid ( nal concentration, 0.02%; Nacalai Tesque) and seeded at a density of 2 × 10 4 viable cells per well in a 96-well BD Falcon tissue culture plate with a low-evaporation lid (BD Biosciences, Franklin Lakes, NJ, USA).…”

Effectiveness of antibacterial agents against cell-invading bacteria such as Streptococcus pyogenes and Haemophilus influenzae

“…Detroit 562 cells (CCL-138; ATCC, Manassas, VA, USA), a human pharyngeal carcinoma epithelial cell line, were grown to confluence in minimal essential medium (Nacalai Tesque Inc., Kyoto, Japan) supplemented with 1 mM sodium pyruvate (Nacalai Tesque), 10% fetal bovine serum (Invitrogen, San Diego, CA, USA), penicillin (100 U/mL), and streptomycin (100 μg/mL; Nacalai Tesque) at 37 °C in a 5% CO 2 incubator as previously described [ 29 ]. The cells were harvested using trypsin (final concentration, 0.02%) and ethylenediaminetetraacetic acid (EDTA; final concentration, 0.02%; Nacalai Tesque) and seeded at a density of 2 × 10 4 viable cells per well in a 96-well BD Falcon tissue culture plate with a low-evaporation lid (BD Biosciences, Franklin Lakes, NJ, USA).…”

Garenoxacin is effective against bacteria invading cells such as Streptococcus pyogenes and Haemophilus influenzae

“…Detroit 562 cells (CCL-138; ATCC, Manassas, VA, USA), a human pharyngeal carcinoma epithelial cell line, were grown to con uence in minimal essential medium (Nacalai Tesque Inc., Kyoto, Japan) supplemented with 1 mM sodium pyruvate (Nacalai Tesque), 10% fetal bovine serum (Invitrogen, San Diego, CA, USA), penicillin (100 U/mL), and streptomycin (100 μg/mL; Nacalai Tesque) at 37ºC in a 5% CO 2 incubator as previous described [16]. The cells were harvested using trypsin ( nal concentration, 0.02%) and ethylenediaminetetraacetic acid (EDTA; nal concentration, 0.02%; Nacalai Tesque) and seeded at a density of 2 × 10 4 viable cells per well in a 96-well BD Falcon tissue culture plate with a lowevaporation lid (BD Biosciences, Franklin Lakes, NJ, USA).…”