Bacteroides fragilis response to subinhibitory concentrations of antimicrobials includes different morphological, physiological and virulence patterns after in vitro selection

Freitas, Michele Cristine Ribeiro de; Silva, Vânia Lúcia; Gameiro, Jacy; Ferreira-Machado, Alessandra Barbosa; Coelho, Cíntia Marques; Cara, Denise Carmona; Diniz, Cláudio Galuppo

doi:10.1016/j.micpath.2014.12.002

Cited by 7 publications

(4 citation statements)

References 36 publications

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“…Thus, the strains continue the division process when in contact with the sub-MICs, but the septation does not occur (DE ANDRADE et al, 2016). On the other hand, in relation to the sub-MICs of MET, changes in bacterial morphology appear to be related to the inhibition of autolytic enzymes that initiate septation (DINIZ et al, 2000;FREITAS et al, 2015).…”

Section: Discussionmentioning

confidence: 99%

“…However, the consequences of these morphological changes as pathogenicity factors and for clinical diagnosis are not well established ( FREITAS et al, 2015;DE ANDRADE et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

“…According to the literature, antimicrobials may interfere with bacterial adhesion to both epithelial and intestinal cells, as well as expression of other pathogenicity factors in various bacterial species (FREITAS et al, 2015). Some antimicrobials may significantly decrease the bacterial adhesion process to certain types of surfaces, which can be explained by a change in the hydrophobicity of the cell surface, inhibition of motility, or possible decrease of the adhesins in the bacterial cell surface due to the induction of filamentous cells (FONSECA et al, 2004).…”

Section: Discussionmentioning

confidence: 99%

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AVALIAÇÃO DA TOXICIDADE AGUDA E DA CITOTOXICIDADE DOS EXTRATOS ETANÓLICOS DA MACRÓFITA Hydrocotyle bonariensis LAM (APIACEAE)

Nascimento¹,

Guedes²,

Bezerra³

et al. 2020

Pesquisa Científica E Tecnológica Em Microbiologia 3

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Todo o conteúdo deste livro está licenciado sob uma Licença de Atribuição Creative Commons. Atribuição 4.0 Internacional (CC BY 4.0). O conteúdo dos artigos e seus dados em sua forma, correção e confiabilidade são de responsabilidade exclusiva dos autores. Permitido o download da obra e o compartilhamento desde que sejam atribuídos créditos aos autores, mas sem a possibilidade de alterá-la de nenhuma forma ou utilizá-la para fins comerciais.

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Section: Discussionmentioning

confidence: 99%

“…However, the consequences of these morphological changes as pathogenicity factors and for clinical diagnosis are not well established ( FREITAS et al, 2015;DE ANDRADE et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

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AVALIAÇÃO DA TOXICIDADE AGUDA E DA CITOTOXICIDADE DOS EXTRATOS ETANÓLICOS DA MACRÓFITA Hydrocotyle bonariensis LAM (APIACEAE)

Nascimento¹,

Guedes²,

Bezerra³

et al. 2020

Pesquisa Científica E Tecnológica Em Microbiologia 3

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“…Add to that, the resident microbiota exposure to subinhibitory concentrations (SIC), which may interfere with microbial ecosystem, may also lead to changes in bacteria-bacteria and bacteria-host relationships related to pleiotropic regulation in bacterial gene expression, as an adaptive response ( Bohnen, 1998 ; Diniz et al, 2004 ). Under SIC of antimicrobial drugs, in vitro studies reported cellular alterations related to the anaerobic bacteria morphology, physiology, and protein expression ( Diniz et al, 2003 ; de Souza Filho et al, 2012 ; Freitas et al, 2015 ).…”

Section: Introductionmentioning

confidence: 99%

Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole

et al. 2016

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Bacteroides fragilis, member from commensal gut microbiota, is an important pathogen associated to endogenous infections and metronidazole remains a valuable antibiotic for the treatment of these infections, although bacterial resistance is widely reported. Considering the need of a better understanding on the global mechanisms by which B. fragilis survive upon metronidazole exposure, we performed a RNA-seq transcriptomic approach with validation of gene expression results by qPCR. Bacteria strains were selected after in vitro subcultures with subinhibitory concentration (SIC) of the drug. From a wild type B. fragilis ATCC 43859 four derivative strains were selected: first and fourth subcultures under metronidazole exposure and first and fourth subcultures after drug removal. According to global gene expression analysis, 2,146 protein coding genes were identified, of which a total of 1,618 (77%) were assigned to a Gene Ontology term (GO), indicating that most known cellular functions were taken. Among these 2,146 protein coding genes, 377 were shared among all strains, suggesting that they are critical for B. fragilis survival. In order to identify distinct expression patterns, we also performed a K-means clustering analysis set to 15 groups. This analysis allowed us to detect the major activated or repressed genes encoding for enzymes which act in several metabolic pathways involved in metronidazole response such as drug activation, defense mechanisms against superoxide ions, high expression level of multidrug eﬄux pumps, and DNA repair. The strains collected after metronidazole removal were functionally more similar to those cultured under drug pressure, reinforcing that drug-exposure lead to drastic persistent changes in the B. fragilis gene expression patterns. These results may help to elucidate B. fragilis response during metronidazole exposure, mainly at SIC, contributing with information about bacterial survival strategies under stress conditions in their environment.

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Sub-Inhibitory Concentration of Piperacillin–Tazobactam May be Related to Virulence Properties of Filamentous Escherichia coli

et al. 2015

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Sub-inhibitory concentrations of antibiotics are always generated as a consequence of antimicrobial therapy and the effects of such residual products in bacterial morphology are well documented, especially the filamentation generated by beta-lactams. The aim of this study was to investigate some morphological and pathological aspects (virulence factors) of Escherichia coli cultivated under half-minimum inhibitory concentration (1.0 µg/mL) of piperacillin-tazobactam (PTZ sub-MIC). PTZ sub-MIC promoted noticeable changes in the bacterial cells which reach the peak of morphological alterations (filamentation) and complexity at 16 h of antimicrobial exposure. Thereafter the filamentous cells and a control one, not treated with PTZ, were comparatively tested for growth curve; biochemical profile; oxidative stress tolerance; biofilm production and cell hydrophobicity; motility and pathogenicity in vivo. PTZ sub-MIC attenuated the E. coli growth rate, but without changes in carbohydrate fermentation or in traditional biochemical tests. Overall, the treatment of E. coli with sub-MIC of PTZ generated filamentous forms which were accompanied by the inhibition of virulence factors such as the oxidative stress response, biofilm formation, cell surface hydrophobicity, and motility. These results are consistent with the reduced pathogenicity observed for the filamentous E. coli in the murine model of intra-abdominal infection. In other words, the treatment of E. coli with sub-MIC of PTZ suggests a decrease in their virulence.

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Bacteroides fragilis response to subinhibitory concentrations of antimicrobials includes different morphological, physiological and virulence patterns after in vitro selection

Cited by 7 publications

References 36 publications

AVALIAÇÃO DA TOXICIDADE AGUDA E DA CITOTOXICIDADE DOS EXTRATOS ETANÓLICOS DA MACRÓFITA Hydrocotyle bonariensis LAM (APIACEAE)

AVALIAÇÃO DA TOXICIDADE AGUDA E DA CITOTOXICIDADE DOS EXTRATOS ETANÓLICOS DA MACRÓFITA Hydrocotyle bonariensis LAM (APIACEAE)

Exploratory Investigation of Bacteroides fragilis Transcriptional Response during In vitro Exposure to Subinhibitory Concentration of Metronidazole

Sub-Inhibitory Concentration of Piperacillin–Tazobactam May be Related to Virulence Properties of Filamentous Escherichia coli

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