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Molecular-based approaches to characterize coastal microbial community and their potential relation to the trophic state of Red Sea.

Ansari MI, Harb M, Jones B, Hong PY - Sci Rep (2015)

Bottom Line: Microbial source tracking revealed the presence of >1 human-associated Bacteroides spp. at some of the near-shore sampling sites and at a heavily frequented beach.Enterococci abundances obtained from next-generation sequencing did not correlate well with the cultured enterococci numbers.Operational taxonomic units (OTUs) associated with cyanobacteria, Prochlorococcus, Ostreococcus spp. and Gramella were more prevalent in waters that were likely impacted by urban runoffs and recreational activities.

View Article: PubMed Central - PubMed

Affiliation: Water Desalination and Reuse Center, Environmental Science and Engineering.

ABSTRACT
Molecular-based approaches were used to characterize the coastal microbiota and to elucidate the trophic state of Red Sea. Nutrient content and enterococci numbers were monitored, and used to correlate with the abundance of microbial markers. Microbial source tracking revealed the presence of >1 human-associated Bacteroides spp. at some of the near-shore sampling sites and at a heavily frequented beach. Water samples collected from the beaches had occasional exceedances in enterococci numbers, higher total organic carbon (TOC, 1.48-2.18 mg/L) and nitrogen (TN, 0.15-0.27 mg/L) than that detected in the near-shore waters. Enterococci abundances obtained from next-generation sequencing did not correlate well with the cultured enterococci numbers. The abundance of certain genera, for example Arcobacter, Pseudomonas and unclassified Campylobacterales, was observed to exhibit slight correlation with TOC and TN. Low abundance of functional genes accounting for up to 41 copies/L of each Pseudomonas aeruginosa and Campylobacter coli were detected. Arcobacter butzleri was also detected in abundance ranging from 111 to 238 copies/L. Operational taxonomic units (OTUs) associated with cyanobacteria, Prochlorococcus, Ostreococcus spp. and Gramella were more prevalent in waters that were likely impacted by urban runoffs and recreational activities. These OTUs could potentially serve as quantifiable markers indicative of the water quality.

No MeSH data available.


Cell abundances in the water samples as determined by flow cytometry.(A) Total cell counts per mL in the KW and TW beach waters, and in the near-shore waters, and (B) Copies per L of regA, glyA and rpoB associated with Pseudomonas aeruginosa, Campylobacter coli and Arcobacter butzleri, respectively.
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f3: Cell abundances in the water samples as determined by flow cytometry.(A) Total cell counts per mL in the KW and TW beach waters, and in the near-shore waters, and (B) Copies per L of regA, glyA and rpoB associated with Pseudomonas aeruginosa, Campylobacter coli and Arcobacter butzleri, respectively.

Mentions: Flow cytometry cell counts revealed that the water samples collected from N sites and along the beach have an average 7.79 × 105 and 6.44 × 105 cells per mL, respectively. In comparison, the average cells count in S, NS and T sites were 1.04 × 106 cells per mL, which was 45.1% higher than that from N and beach sites (Figure 3A). To approximate the cell abundance of selected genera associated with opportunistic pathogens, we multiplied the relative abundance of individual genera obtained from next-generation sequencing to the total microbial cell counts obtained from flow cytometry. Table 3 showed that the cell abundance of bacterial groups associated with Acinetobacter, Arcobacter, Pseudomonas and unclassified Campylobacterales in both KW and TW beach water samples ranged from 2.61 × 103 to 2.47 × 106 cells/L, and these abundances were higher compared to all other near-shore waters (Table 3). In particular, the abundance of Arcobacter detected by next-generation sequencing was significantly higher in the TW beach waters than all other samples (One-way ANOVA, p < 0.001). The abundance of Acinetobacter in KW waters was also significantly higher than those detected in the near-shore waters (One-way ANOVA, p = 0.002). With the exception of Acinetobacter spp., the relative abundance of bacterial populations Arcobacter, Pseudomonas and unclassified Campylobacterales exhibited a slight but significant correlation (Spearman's rank correlation, rS = 0.33–0.44) to the TOC and TN concentrations in the water samples (Table 3). However, only Arcobacter and unclassified Campylobacterales exhibited a significant correlation with the enterococci MPN (Table 3).


Molecular-based approaches to characterize coastal microbial community and their potential relation to the trophic state of Red Sea.

Ansari MI, Harb M, Jones B, Hong PY - Sci Rep (2015)

Cell abundances in the water samples as determined by flow cytometry.(A) Total cell counts per mL in the KW and TW beach waters, and in the near-shore waters, and (B) Copies per L of regA, glyA and rpoB associated with Pseudomonas aeruginosa, Campylobacter coli and Arcobacter butzleri, respectively.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4355682&req=5

f3: Cell abundances in the water samples as determined by flow cytometry.(A) Total cell counts per mL in the KW and TW beach waters, and in the near-shore waters, and (B) Copies per L of regA, glyA and rpoB associated with Pseudomonas aeruginosa, Campylobacter coli and Arcobacter butzleri, respectively.
Mentions: Flow cytometry cell counts revealed that the water samples collected from N sites and along the beach have an average 7.79 × 105 and 6.44 × 105 cells per mL, respectively. In comparison, the average cells count in S, NS and T sites were 1.04 × 106 cells per mL, which was 45.1% higher than that from N and beach sites (Figure 3A). To approximate the cell abundance of selected genera associated with opportunistic pathogens, we multiplied the relative abundance of individual genera obtained from next-generation sequencing to the total microbial cell counts obtained from flow cytometry. Table 3 showed that the cell abundance of bacterial groups associated with Acinetobacter, Arcobacter, Pseudomonas and unclassified Campylobacterales in both KW and TW beach water samples ranged from 2.61 × 103 to 2.47 × 106 cells/L, and these abundances were higher compared to all other near-shore waters (Table 3). In particular, the abundance of Arcobacter detected by next-generation sequencing was significantly higher in the TW beach waters than all other samples (One-way ANOVA, p < 0.001). The abundance of Acinetobacter in KW waters was also significantly higher than those detected in the near-shore waters (One-way ANOVA, p = 0.002). With the exception of Acinetobacter spp., the relative abundance of bacterial populations Arcobacter, Pseudomonas and unclassified Campylobacterales exhibited a slight but significant correlation (Spearman's rank correlation, rS = 0.33–0.44) to the TOC and TN concentrations in the water samples (Table 3). However, only Arcobacter and unclassified Campylobacterales exhibited a significant correlation with the enterococci MPN (Table 3).

Bottom Line: Microbial source tracking revealed the presence of >1 human-associated Bacteroides spp. at some of the near-shore sampling sites and at a heavily frequented beach.Enterococci abundances obtained from next-generation sequencing did not correlate well with the cultured enterococci numbers.Operational taxonomic units (OTUs) associated with cyanobacteria, Prochlorococcus, Ostreococcus spp. and Gramella were more prevalent in waters that were likely impacted by urban runoffs and recreational activities.

View Article: PubMed Central - PubMed

Affiliation: Water Desalination and Reuse Center, Environmental Science and Engineering.

ABSTRACT
Molecular-based approaches were used to characterize the coastal microbiota and to elucidate the trophic state of Red Sea. Nutrient content and enterococci numbers were monitored, and used to correlate with the abundance of microbial markers. Microbial source tracking revealed the presence of >1 human-associated Bacteroides spp. at some of the near-shore sampling sites and at a heavily frequented beach. Water samples collected from the beaches had occasional exceedances in enterococci numbers, higher total organic carbon (TOC, 1.48-2.18 mg/L) and nitrogen (TN, 0.15-0.27 mg/L) than that detected in the near-shore waters. Enterococci abundances obtained from next-generation sequencing did not correlate well with the cultured enterococci numbers. The abundance of certain genera, for example Arcobacter, Pseudomonas and unclassified Campylobacterales, was observed to exhibit slight correlation with TOC and TN. Low abundance of functional genes accounting for up to 41 copies/L of each Pseudomonas aeruginosa and Campylobacter coli were detected. Arcobacter butzleri was also detected in abundance ranging from 111 to 238 copies/L. Operational taxonomic units (OTUs) associated with cyanobacteria, Prochlorococcus, Ostreococcus spp. and Gramella were more prevalent in waters that were likely impacted by urban runoffs and recreational activities. These OTUs could potentially serve as quantifiable markers indicative of the water quality.

No MeSH data available.