Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis

Detalhes bibliográficos
Autor(a) principal: Lopes, Susana Patrícia
Data de Publicação: 2012
Outros Autores: Azevedo, N. F., Pereira, Maria Olívia
Idioma: eng
Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
Texto Completo: http://hdl.handle.net/1822/28574
Resumo: One of the main manifestations of cystic fibrosis (CF) is a decreased clearance of mucus with concomitant bacterial lung infections. Infections are caused by a wide variety of organisms, which includes not only the typical “residents” but also other uncommon bacteria. It has been widely demonstrated that steep oxygen gradients exist within the mucus layers of cystic fibrosis, giving rise to hypoxic/anaerobic areas where bacteria may colonize and proliferate. In this study, it was aimed to investigate the responses of conventional and atypical bacterial species related with CF, when exposed to environments with different oxygen availability, in terms of biofilm growth and antibiotic susceptibility patterns. Single biofilms of the traditional pathogen Pseudomonas aeruginosa, and two uncommon pathogenic bacteria, Inquilinus limosus and Dolosigranulum pigrum, were formed in vitro under aerobic, microaerophilic and anaerobic environments in microtiter plates, and their biomass and respiratory activity were further evaluated. The planktonic and biofilm susceptibility patterns were also tested against eight clinically relevant antibiotics under the same conditions, by measuring the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC), respectively. All organisms showed ability to grow under milieus with distinct oxygen availability, however, D. pigrum developed biofilms with a higher amount of biomass and respiratory activity, particularly those formed under microaerophilic conditions. The susceptibility patterns of planktonic cultures revealed antibiotic tolerance of microorganisms under aerobic environments, decreasing their resistance under environments with oxygen depletion. However, MBEC data were significantly higher than MIC values for most antibiotics, revealing that the bactericidal activity was significantly disturbed once biofilms are established. Moreover, the biofilms formed by the atypical species surprisingly exhibited significant multidrug resistance comparing with P. aeruginosa biofilms, which was independent of oxygen availability in the environment. This study enabled to conclude that restricted-oxygen atmospheres, as occurs in CF airways, may favor the growth and colonization of other microorganisms that are not conventional, making biofilms more resistant to antibiotics. Thus, CF must be regarded as an environmental habitat where the existence of hypoxic or anaerobic regions affects the ability of the bacteria to allocate, proliferate and resist to antibiotics. A more detailed knowledge on this area might hence be crucial for the success of infection treatment.
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spelling Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic FibrosisOxygen limitationCystic FibrosisPseudomonas aeruginosaMucusBiofilmOne of the main manifestations of cystic fibrosis (CF) is a decreased clearance of mucus with concomitant bacterial lung infections. Infections are caused by a wide variety of organisms, which includes not only the typical “residents” but also other uncommon bacteria. It has been widely demonstrated that steep oxygen gradients exist within the mucus layers of cystic fibrosis, giving rise to hypoxic/anaerobic areas where bacteria may colonize and proliferate. In this study, it was aimed to investigate the responses of conventional and atypical bacterial species related with CF, when exposed to environments with different oxygen availability, in terms of biofilm growth and antibiotic susceptibility patterns. Single biofilms of the traditional pathogen Pseudomonas aeruginosa, and two uncommon pathogenic bacteria, Inquilinus limosus and Dolosigranulum pigrum, were formed in vitro under aerobic, microaerophilic and anaerobic environments in microtiter plates, and their biomass and respiratory activity were further evaluated. The planktonic and biofilm susceptibility patterns were also tested against eight clinically relevant antibiotics under the same conditions, by measuring the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC), respectively. All organisms showed ability to grow under milieus with distinct oxygen availability, however, D. pigrum developed biofilms with a higher amount of biomass and respiratory activity, particularly those formed under microaerophilic conditions. The susceptibility patterns of planktonic cultures revealed antibiotic tolerance of microorganisms under aerobic environments, decreasing their resistance under environments with oxygen depletion. However, MBEC data were significantly higher than MIC values for most antibiotics, revealing that the bactericidal activity was significantly disturbed once biofilms are established. Moreover, the biofilms formed by the atypical species surprisingly exhibited significant multidrug resistance comparing with P. aeruginosa biofilms, which was independent of oxygen availability in the environment. This study enabled to conclude that restricted-oxygen atmospheres, as occurs in CF airways, may favor the growth and colonization of other microorganisms that are not conventional, making biofilms more resistant to antibiotics. Thus, CF must be regarded as an environmental habitat where the existence of hypoxic or anaerobic regions affects the ability of the bacteria to allocate, proliferate and resist to antibiotics. A more detailed knowledge on this area might hence be crucial for the success of infection treatment.Universidade do MinhoLopes, Susana PatríciaAzevedo, N. F.Pereira, Maria Olívia20122012-01-01T00:00:00Zconference objectinfo:eu-repo/semantics/publishedVersionapplication/pdfhttp://hdl.handle.net/1822/28574enginfo:eu-repo/semantics/openAccessreponame:Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)instname:Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãoinstacron:RCAAP2024-05-11T05:29:54Zoai:repositorium.sdum.uminho.pt:1822/28574Portal AgregadorONGhttps://www.rcaap.pt/oai/openairemluisa.alvim@gmail.comopendoar:71602024-05-11T05:29:54Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informaçãofalse
dc.title.none.fl_str_mv Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
title Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
spellingShingle Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
Lopes, Susana Patrícia
Oxygen limitation
Cystic Fibrosis
Pseudomonas aeruginosa
Mucus
Biofilm
title_short Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
title_full Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
title_fullStr Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
title_full_unstemmed Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
title_sort Impact of environments with distinct oxygen availability on biofilm growth and susceptibility patterns of traditional and emerging species in Cystic Fibrosis
author Lopes, Susana Patrícia
author_facet Lopes, Susana Patrícia
Azevedo, N. F.
Pereira, Maria Olívia
author_role author
author2 Azevedo, N. F.
Pereira, Maria Olívia
author2_role author
author
dc.contributor.none.fl_str_mv Universidade do Minho
dc.contributor.author.fl_str_mv Lopes, Susana Patrícia
Azevedo, N. F.
Pereira, Maria Olívia
dc.subject.por.fl_str_mv Oxygen limitation
Cystic Fibrosis
Pseudomonas aeruginosa
Mucus
Biofilm
topic Oxygen limitation
Cystic Fibrosis
Pseudomonas aeruginosa
Mucus
Biofilm
description One of the main manifestations of cystic fibrosis (CF) is a decreased clearance of mucus with concomitant bacterial lung infections. Infections are caused by a wide variety of organisms, which includes not only the typical “residents” but also other uncommon bacteria. It has been widely demonstrated that steep oxygen gradients exist within the mucus layers of cystic fibrosis, giving rise to hypoxic/anaerobic areas where bacteria may colonize and proliferate. In this study, it was aimed to investigate the responses of conventional and atypical bacterial species related with CF, when exposed to environments with different oxygen availability, in terms of biofilm growth and antibiotic susceptibility patterns. Single biofilms of the traditional pathogen Pseudomonas aeruginosa, and two uncommon pathogenic bacteria, Inquilinus limosus and Dolosigranulum pigrum, were formed in vitro under aerobic, microaerophilic and anaerobic environments in microtiter plates, and their biomass and respiratory activity were further evaluated. The planktonic and biofilm susceptibility patterns were also tested against eight clinically relevant antibiotics under the same conditions, by measuring the minimum inhibitory concentration (MIC) and minimum biofilm eradication concentration (MBEC), respectively. All organisms showed ability to grow under milieus with distinct oxygen availability, however, D. pigrum developed biofilms with a higher amount of biomass and respiratory activity, particularly those formed under microaerophilic conditions. The susceptibility patterns of planktonic cultures revealed antibiotic tolerance of microorganisms under aerobic environments, decreasing their resistance under environments with oxygen depletion. However, MBEC data were significantly higher than MIC values for most antibiotics, revealing that the bactericidal activity was significantly disturbed once biofilms are established. Moreover, the biofilms formed by the atypical species surprisingly exhibited significant multidrug resistance comparing with P. aeruginosa biofilms, which was independent of oxygen availability in the environment. This study enabled to conclude that restricted-oxygen atmospheres, as occurs in CF airways, may favor the growth and colonization of other microorganisms that are not conventional, making biofilms more resistant to antibiotics. Thus, CF must be regarded as an environmental habitat where the existence of hypoxic or anaerobic regions affects the ability of the bacteria to allocate, proliferate and resist to antibiotics. A more detailed knowledge on this area might hence be crucial for the success of infection treatment.
publishDate 2012
dc.date.none.fl_str_mv 2012
2012-01-01T00:00:00Z
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collection Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
repository.name.fl_str_mv Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos) - Agência para a Sociedade do Conhecimento (UMIC) - FCT - Sociedade da Informação
repository.mail.fl_str_mv mluisa.alvim@gmail.com
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