Limits...
Characterization of bacteria in ballast water using MALDI-TOF mass spectrometry.

Emami K, Askari V, Ullrich M, Mohinudeen K, Anil AC, Khandeparker L, Burgess JG, Mesbahi E - PLoS ONE (2012)

Bottom Line: To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).Seawater samples collected from the North Sea were incubated in steel ballast tanks and the presence of potentially harmful species of Pseudomonas was also investigated.At the genus-level, the identification of thirty six isolates using MALDI-TOF MS produced similar results to those obtained by 16S rRNA gene sequencing.

View Article: PubMed Central - PubMed

Affiliation: School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom. kaveh.emami@ncl.ac.uk

ABSTRACT
To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Since International Maritime Organization (IMO) regulations are concerned with the unintended transportation of pathogenic bacteria through ballast water, emphasis was placed on detecting species of Vibrio, enterococci and coliforms. Seawater samples collected from the North Sea were incubated in steel ballast tanks and the presence of potentially harmful species of Pseudomonas was also investigated. At the genus-level, the identification of thirty six isolates using MALDI-TOF MS produced similar results to those obtained by 16S rRNA gene sequencing. No pathogenic species were detected either by 16S rRNA gene analysis or by MALDI-TOF MS except for the opportunistically pathogenic bacterium Pseudomonas aeruginosa. In addition, in house software that calculated the correlation coefficient values (CCV) of the mass spectral raw data and their variation was developed and used to allow the rapid and efficient identification of marine bacteria in ballast water for the first time.

Show MeSH

Related in: MedlinePlus

Examples of in-house CCV analysis of Vibrio isolates S14 and S27 (A) and S14 and S32 (B).Panel C shows the spectrograms of Vibrio isolates S14, S27, S30, and S32.
© Copyright Policy
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3369924&req=5

pone-0038515-g009: Examples of in-house CCV analysis of Vibrio isolates S14 and S27 (A) and S14 and S32 (B).Panel C shows the spectrograms of Vibrio isolates S14, S27, S30, and S32.

Mentions: In order to evaluate the potential of our in-house software, mass spectra of selected isolates of Vibrio, Pseudomonas, and Pseudoalteromonas were subjected to more detailed analysis. Mass spectra of the four closely related Vibrio isolates S14, S27, S30, and S32, were compared by calculating a CCV matrix. MS data showed that the major peaks present in all four isolates had similar m/z but different intensities (see Figs. 1 and 2). Plots of normalized data for these four isolates are presented in Table 3 and Figure 9, where panels A and B compare the spectrum of isolate S14 with those of isolates S27 and S32. The results shown in Table 3 indicate that with 92% confidence Vibrio isolates S14 and S32 were closest to each other confirming the conclusions of the 16SrRNA gene sequences phylogram (Fig. 1, panel B) There is a high possibility that isolates S14 and S27 or S14 and S32, respectively, are identical species (CCV 0.88). However, when 12 repeats of the E. coli standard (Bruker Daltonics) using 600 laser shots for each sample were analyzed, inter-specific variation of the CCV was in the range of 0.9–1.0 (data not shown). Consequently, this level of variance would rule out the existence of a significant mass difference in the spectra of the Vibrio isolates detectable by CCV analysis.


Characterization of bacteria in ballast water using MALDI-TOF mass spectrometry.

Emami K, Askari V, Ullrich M, Mohinudeen K, Anil AC, Khandeparker L, Burgess JG, Mesbahi E - PLoS ONE (2012)

Examples of in-house CCV analysis of Vibrio isolates S14 and S27 (A) and S14 and S32 (B).Panel C shows the spectrograms of Vibrio isolates S14, S27, S30, and S32.
© Copyright Policy
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3369924&req=5

pone-0038515-g009: Examples of in-house CCV analysis of Vibrio isolates S14 and S27 (A) and S14 and S32 (B).Panel C shows the spectrograms of Vibrio isolates S14, S27, S30, and S32.
Mentions: In order to evaluate the potential of our in-house software, mass spectra of selected isolates of Vibrio, Pseudomonas, and Pseudoalteromonas were subjected to more detailed analysis. Mass spectra of the four closely related Vibrio isolates S14, S27, S30, and S32, were compared by calculating a CCV matrix. MS data showed that the major peaks present in all four isolates had similar m/z but different intensities (see Figs. 1 and 2). Plots of normalized data for these four isolates are presented in Table 3 and Figure 9, where panels A and B compare the spectrum of isolate S14 with those of isolates S27 and S32. The results shown in Table 3 indicate that with 92% confidence Vibrio isolates S14 and S32 were closest to each other confirming the conclusions of the 16SrRNA gene sequences phylogram (Fig. 1, panel B) There is a high possibility that isolates S14 and S27 or S14 and S32, respectively, are identical species (CCV 0.88). However, when 12 repeats of the E. coli standard (Bruker Daltonics) using 600 laser shots for each sample were analyzed, inter-specific variation of the CCV was in the range of 0.9–1.0 (data not shown). Consequently, this level of variance would rule out the existence of a significant mass difference in the spectra of the Vibrio isolates detectable by CCV analysis.

Bottom Line: To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).Seawater samples collected from the North Sea were incubated in steel ballast tanks and the presence of potentially harmful species of Pseudomonas was also investigated.At the genus-level, the identification of thirty six isolates using MALDI-TOF MS produced similar results to those obtained by 16S rRNA gene sequencing.

View Article: PubMed Central - PubMed

Affiliation: School of Biology, Newcastle University, Newcastle upon Tyne, United Kingdom. kaveh.emami@ncl.ac.uk

ABSTRACT
To evaluate a rapid and cost-effective method for monitoring bacteria in ballast water, several marine bacterial isolates were characterized by matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS). Since International Maritime Organization (IMO) regulations are concerned with the unintended transportation of pathogenic bacteria through ballast water, emphasis was placed on detecting species of Vibrio, enterococci and coliforms. Seawater samples collected from the North Sea were incubated in steel ballast tanks and the presence of potentially harmful species of Pseudomonas was also investigated. At the genus-level, the identification of thirty six isolates using MALDI-TOF MS produced similar results to those obtained by 16S rRNA gene sequencing. No pathogenic species were detected either by 16S rRNA gene analysis or by MALDI-TOF MS except for the opportunistically pathogenic bacterium Pseudomonas aeruginosa. In addition, in house software that calculated the correlation coefficient values (CCV) of the mass spectral raw data and their variation was developed and used to allow the rapid and efficient identification of marine bacteria in ballast water for the first time.

Show MeSH
Related in: MedlinePlus