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Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures

Background: Rapid diagnostics of pathogens is essential to prescribe appropriate antibiotic therapy. The current methods for pathogen detection require the bacteria to grow in a culture medium, which is time-consuming. This increases the mortality rate and global burden of antimicrobial resistance....

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Autores principales: Ali, Jawad, Joshi, Mukund, Ahmadi, Asal, Strætkvern, Knut Olav, Ahmad, Rafi
Formato: Online Artículo Texto
Lenguaje:English
Publicado: F1000 Research Limited 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10133824/
https://www.ncbi.nlm.nih.gov/pubmed/37122874
http://dx.doi.org/10.12688/f1000research.129668.2
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author Ali, Jawad
Joshi, Mukund
Ahmadi, Asal
Strætkvern, Knut Olav
Ahmad, Rafi
author_facet Ali, Jawad
Joshi, Mukund
Ahmadi, Asal
Strætkvern, Knut Olav
Ahmad, Rafi
author_sort Ali, Jawad
collection PubMed
description Background: Rapid diagnostics of pathogens is essential to prescribe appropriate antibiotic therapy. The current methods for pathogen detection require the bacteria to grow in a culture medium, which is time-consuming. This increases the mortality rate and global burden of antimicrobial resistance. Culture-free detection methods are still under development and are not common in the clinical routine. Therefore, decreasing the culture time for accurately detecting infection and resistance is vital for diagnosis. Methods: This study investigated easy-to-implement factors (in a minimal laboratory set-up), including inoculum size, incubation temperature, and additional supplementation ( e.g., vitamin B12 and trace metals), that can significantly reduce the bacterial lag time (t (lag)). These factors were arranged in simple two-level factorial designs using Gram-positive cocci ( Staphylococcus aureus), Gram-positive bacilli ( Bacillus subtilis), and Gram-negative bacilli ( Escherichia coli and Pseudomonas aeruginosa) bacteria, including clinical isolates with known antimicrobial resistance profiles. Blood samples spiked with a clinical isolate of E. coli CCUG 17620 (Culture Collection University of Gothenburg) were also tested to see the effect of elevated incubation temperature on bacterial growth in blood cultures. Results: We observed that increased incubation temperature (42°C) along with vitamin B12 supplementation significantly reduced the t (lag) (10 – 115 minutes or 4% - 49%) in pure clinical isolates and blood samples spiked with E. coli CCUG17620. In the case of the blood sample, PCR results also detected bacterial DNA after only 3h of incubation and at three times the CFU/mL. Conclusion: Enrichment of bacterial culture media with growth supplements such as vitamin B12 and increased incubation temperature can be a cheap and rapid method for the early detection of pathogens. This proof-of-concept study is restricted to a few bacterial strains and growth conditions. In the future, the effect of other growth conditions and difficult-to-culture bacteria should be explored to shorten the lag phase.
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spelling pubmed-101338242023-04-28 Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures Ali, Jawad Joshi, Mukund Ahmadi, Asal Strætkvern, Knut Olav Ahmad, Rafi F1000Res Research Article Background: Rapid diagnostics of pathogens is essential to prescribe appropriate antibiotic therapy. The current methods for pathogen detection require the bacteria to grow in a culture medium, which is time-consuming. This increases the mortality rate and global burden of antimicrobial resistance. Culture-free detection methods are still under development and are not common in the clinical routine. Therefore, decreasing the culture time for accurately detecting infection and resistance is vital for diagnosis. Methods: This study investigated easy-to-implement factors (in a minimal laboratory set-up), including inoculum size, incubation temperature, and additional supplementation ( e.g., vitamin B12 and trace metals), that can significantly reduce the bacterial lag time (t (lag)). These factors were arranged in simple two-level factorial designs using Gram-positive cocci ( Staphylococcus aureus), Gram-positive bacilli ( Bacillus subtilis), and Gram-negative bacilli ( Escherichia coli and Pseudomonas aeruginosa) bacteria, including clinical isolates with known antimicrobial resistance profiles. Blood samples spiked with a clinical isolate of E. coli CCUG 17620 (Culture Collection University of Gothenburg) were also tested to see the effect of elevated incubation temperature on bacterial growth in blood cultures. Results: We observed that increased incubation temperature (42°C) along with vitamin B12 supplementation significantly reduced the t (lag) (10 – 115 minutes or 4% - 49%) in pure clinical isolates and blood samples spiked with E. coli CCUG17620. In the case of the blood sample, PCR results also detected bacterial DNA after only 3h of incubation and at three times the CFU/mL. Conclusion: Enrichment of bacterial culture media with growth supplements such as vitamin B12 and increased incubation temperature can be a cheap and rapid method for the early detection of pathogens. This proof-of-concept study is restricted to a few bacterial strains and growth conditions. In the future, the effect of other growth conditions and difficult-to-culture bacteria should be explored to shorten the lag phase. F1000 Research Limited 2023-04-03 /pmc/articles/PMC10133824/ /pubmed/37122874 http://dx.doi.org/10.12688/f1000research.129668.2 Text en Copyright: © 2023 Ali J et al. https://creativecommons.org/licenses/by/4.0/This is an open access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
spellingShingle Research Article
Ali, Jawad
Joshi, Mukund
Ahmadi, Asal
Strætkvern, Knut Olav
Ahmad, Rafi
Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title_full Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title_fullStr Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title_full_unstemmed Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title_short Increased growth temperature and vitamin B12 supplementation reduces the lag time for rapid pathogen identification in BHI agar and blood cultures
title_sort increased growth temperature and vitamin b12 supplementation reduces the lag time for rapid pathogen identification in bhi agar and blood cultures
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10133824/
https://www.ncbi.nlm.nih.gov/pubmed/37122874
http://dx.doi.org/10.12688/f1000research.129668.2
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