Transition in Vibrio spp. correlates with human activity in the Northern Line Islands
Robert Schmieder, Tracy McDole, Elizabeth Dinsdale, Matthew Haynes, Forest Rohwer, Robert Edwards
E D W A R D S
L A B
A T
S A N
Introduction
Northern Line Islands Global map of cumula=ve human impact on the oceans showing the Northern Line Islands in an area of low impact. Data used from Halpern et al. 2008, “A Global Map of Human Impact on Marine Ecosystems”, Science 319:948‐952. 20 23 26 2 11 15 16 1 5 5 8 6 10 13 16 14 26 Locally on islands Pick colonies and store in Count grown Allprotect Tissue Reagent colonies 11 5 21 17 Photobacterium rosenbergii Results
24 17 14 ‐ Vibrio kanaloae 15 ‐ Vibrio mediterranei 16 ‐ Vibrio mimicus 17 ‐ Vibrio navarrensis 18 ‐ Vibrio nigripulchritudo 19 ‐ Vibrio pacinii 20 ‐ Vibrio parahaemoly=cus 21 ‐ Vibrio proteoly=cus 22 ‐ Vibrio scophthalmi 23 ‐ Vibrio shilonii 24 ‐ Vibrio tubiashii 25 ‐ Vibrio vulniﬁcus 26 ‐ Vibrio xuii 19 21 1 2 4 5 7 9 11 17 12 Kiri=ma= (5,115) High
human
activity
Medium
human
activity
V. campbellii P. leiognathi P. damselae P. rosenbergii V. scophthalmi P. damselae V. harveyi V. harveyi associated with coral bleaching Vibrio shilonii 11 Tabuaeran (2,539) 1 ‐ Enterovibrio coralii 2 ‐ Salinivibrio cos=cola 3 ‐ Vibrio aestuarianus 4 ‐ Vibrio campbellii 5 ‐ Vibrio cholerae 6 ‐ Vibrio cincinna=ensis 7 ‐ Vibrio coralliily=cus 8 ‐ Vibrio ﬂuvialis 9 ‐ Vibrio for=s 10 ‐ Vibrio halio=coli 11 ‐ Vibrio harveyi 12 ‐ Vibrio hepatarius 13 ‐ Vibrio ichthyoenteri V. harveyi Enterovibrio coralii 1 Overview of Kiri=ma= Island showing the 5 sites where water and coral samples were collected. The pie charts show the abundance of bacteria based on the culture‐
dependent MLSA analysis. Collec=ng water and coral samples from diﬀerent transects Vibrio harveyi ‐ pathogen to ﬁsh and invertebrates, including lobster and shrimp Vibrio coraliity9cs 17 Kiritimati survey
Methods
Filtering seawater through a ﬁlter to isolate bacteria Palmyra (20) 21 22 25 3 2 U N I V E R S I T Y
Pathogenic Vibrionaceae found
Chart data based on 1104 recA sequences; popula=on numbers from 2005 are shown in parenthesis Kingman (0) Low Pla=ng seawater and coral samples on Vibrio‐selec=ve TCBS agar S T A T E
Northern Line Islands survey
The ini=al microbiological survey of the Northern Line Islands showed that most cultured Vibrio species were found on Kiri=ma=, fewer on Tabuaeran and Palmyra, and least on Kingman. In contrast, a culture‐independent survey by metagenomics – random sequencing of environmental DNA – from these islands showed rela=vely consistent numbers of Vibrio spp. at each island. Neither the culturing nor the meta‐
genomics could accurately iden=fy the exact species present. Therefore, we used a mul=‐locus sequencing approach (MLSA) to analyze the water samples at each island. In addi=on, to determine whether the changes in Vibrio popula=on were biogeographic or human inﬂuenced, culture‐dependent and culture‐independent surveys were conducted around Kiri=ma= Island. Kiri=ma= was chosen based on the distribu=on and ac=vity of people around the island. The culture‐independent surveys provides a non biased assessment of the Vibrio spp. in the environment, whereas culturing was developed to selec=vely iden=fy microbes, par=cularly those that were disease causing. High D I E G O
V. shilonii S. loihica The analysis demonstrates that there is a consistent background of Vibrio spp. present everywhere and detectable by metagenomics, and addi=onal species present at the speciﬁc loca=ons where Vibrios were readily cultured. Within the Vibrio strains iden=ﬁed across the islands there appeared to be more pathogenic strains present on Kiri=ma= where the ecosystem had undergone some perturba=on. The culture‐dependent and culture‐independent surveys around Kiri=ma= Island recapitulate this result. Only one species of Vibrio (V. harveyi ) was found on Kiri=ma= closest to the high levels of human ac=vity, sugges=ng that human ac=vity reduced the diversity of the microbial popula=ons and encouraged the growth of poten=ally pathogenic strains. The prevalence of coral disease was highest on these reefs near the human popula=on and the changes to the microbial popula=on may be a leading cause. This study demonstrates a correla=on between human ac=vity and Vibrio spp. popula=on and removes some of the confounding factors, such as la=tude, which were present in the inter‐island study. Acknowledgment
Thanks to Bahador Nosrat for providing the global map, the Rohwer Lab and Edwards Lab for funding. V. splendidus E. coralii S. amazonensis V. harveyi V. nigripulchritudo Extract DNA from picked colonies PCR microbial DNA with Vibrio‐speciﬁc primers Clone PCR products into E. coli Purify PCR products Pick colony and sequence Sequence Culture‐independent Culture‐dependent Low
human
activity
V. brasiliensis Further information
Please contact [email protected]. This poster is available online at edwards.sdsu.edu/posters/icrs2008.pdf CoralSurvey Please help us and take the survey on coral reefs at coralsurvey.sdsu.edu V. campbellii u V. harveyi P. damselae .sds
u.ed
PCR microbial DNA with Vibrio‐speciﬁc primers Wet lab at SDSU Extract DNA from ﬁlters using beats 