OBJECTIVES/HYPOTHESIS: Biofilms occur in animal models of acute otitis media (AOM) and in children with recurrent AOM (rAOM) and chronic otitis media with effusion (OME). We therefore studied the ability of nontypeable Haemophilus influenzae (NTHi) strains from children to form biofilms in vitro under conditions we presumed occurred in the middle ear during AOM, rAOM, and OME. STUDY DESIGN: Evaluate NTHi isolates for biofilm formation across a pH range under aerobic, microaerophilic, and anaerobic conditions. METHODS: Using a crystal violet biofilm assay we studied 12 NTHi pediatric clinical isolates to investigate biofilm formation over a pH range of 4.5 to 10 under aerobic, microaerophilic, and anaerobic conditions. RESULTS: Our findings included: 1) not all clinical NTHi strains form biofilms (75% did); 2) the pH of middle ear fluid collected from AOM (n = 170; age range, 4-36 months), rAOM (n = 54; age range, 7-36 months), and OME (n = 30; age range, 9-60 months) subjects tested immediately after withdrawal was similar (mean = 8.0;range 7.0-9.0); 3) biofilms formed optimally at pH 8.0, a finding that is consistent with previous studies by other investigators; 4) biofilms did not form under aerobic conditions as likely occurs in AOM, whereas under microaerophilic and anaerobic conditions biofilm formation was observed as likely occurs during rAOM and OME. CONCLUSIONS: We concluded that biofilm formation by NTHi does not occur in all strains, occurs best where the pH = 8.0 and in anaerobic conditions as likely occurs in children during rAOM and OME. However, biofilm formation is limited or absent under aerobic conditions as likely occurs during AOM. LEVEL OF EVIDENCE: NA.
OBJECTIVES/HYPOTHESIS: Biofilms occur in animal models of acute otitis media (AOM) and in children with recurrent AOM (rAOM) and chronic otitis media with effusion (OME). We therefore studied the ability of nontypeable Haemophilus influenzae (NTHi) strains from children to form biofilms in vitro under conditions we presumed occurred in the middle ear during AOM, rAOM, and OME. STUDY DESIGN: Evaluate NTHi isolates for biofilm formation across a pH range under aerobic, microaerophilic, and anaerobic conditions. METHODS: Using a crystal violet biofilm assay we studied 12 NTHi pediatric clinical isolates to investigate biofilm formation over a pH range of 4.5 to 10 under aerobic, microaerophilic, and anaerobic conditions. RESULTS: Our findings included: 1) not all clinical NTHi strains form biofilms (75% did); 2) the pH of middle ear fluid collected from AOM (n = 170; age range, 4-36 months), rAOM (n = 54; age range, 7-36 months), and OME (n = 30; age range, 9-60 months) subjects tested immediately after withdrawal was similar (mean = 8.0;range 7.0-9.0); 3) biofilms formed optimally at pH 8.0, a finding that is consistent with previous studies by other investigators; 4) biofilms did not form under aerobic conditions as likely occurs in AOM, whereas under microaerophilic and anaerobic conditions biofilm formation was observed as likely occurs during rAOM and OME. CONCLUSIONS: We concluded that biofilm formation by NTHi does not occur in all strains, occurs best where the pH = 8.0 and in anaerobic conditions as likely occurs in children during rAOM and OME. However, biofilm formation is limited or absent under aerobic conditions as likely occurs during AOM. LEVEL OF EVIDENCE: NA.
Authors: Guillermo L Monroy; Paritosh Pande; Ryan M Nolan; Ryan L Shelton; Ryan G Porter; Michael A Novak; Darold R Spillman; Eric J Chaney; Daniel T McCormick; Stephen A Boppart Journal: J Biomed Opt Date: 2017-12 Impact factor: 3.170
Authors: Guillermo L Monroy; Wenzhou Hong; Pawjai Khampang; Ryan G Porter; Michael A Novak; Darold R Spillman; Ronit Barkalifa; Eric J Chaney; Joseph E Kerschner; Stephen A Boppart Journal: Otolaryngol Head Neck Surg Date: 2018-03-27 Impact factor: 3.497
Authors: Carine Ysebaert; Philippe Denoël; Vincent Weynants; Lauren O Bakaletz; Laura A Novotny; Fabrice Godfroid; Philippe Hermand Journal: Infect Immun Date: 2019-07-23 Impact factor: 3.441
Authors: Judith M Martin; Alejandro Hoberman; Nader Shaikh; Timothy Shope; S Onika Bhatnagar; Stan L Block; Mary Ann Haralam; Marcia Kurs-Lasky; Michael Green Journal: Open Forum Infect Dis Date: 2018-02-17 Impact factor: 3.835