Chuuk State Research Articles

Metavirome Profiling and Dynamics of the DNA Viral Community in Seawater in Chuuk State, Federated States of Micronesia.

Despite their abundance and ecological importance, little is known about the diversity of marine viruses, in part because most cannot be cultured in the laboratory. Here, we used high-throughput viral metagenomics of uncultivated viruses to investigate the dynamics of DNA viruses in tropical seawater sampled from Chuuk State, Federated States of Micronesia, in March, June, and December 2014. Among the identified viruses, 71-79% were bacteriophages belonging to the families Myoviridae, Siphoviridae, and Podoviridae (Caudoviriales), listed in order of abundance at all sampling times. Although the measured environmental factors (temperature, salinity, and pH) remained unchanged in the seawater over time, viral dynamics changed. The proportion of cyanophages (34.7%) was highest in June, whereas the proportion of mimiviruses, phycodnaviruses, and other nucleo-cytoplasmic large DNA viruses (NCLDVs) was higher in March and December. Although host species were not analysed, the dramatic viral community change observed in June was likely due to changes in the abundance of cyanophage-infected cyanobacteria, whereas that in NCLDVs was likely due to the abundance of potential eukaryote-infected hosts. These results serve as a basis for comparative analyses of other marine viral communities, and guide policy-making when considering marine life care in Chuuk State.

Caulerpa Bikinensis (Chlorophyta) Preference for the Mesophotic Depths of Pacific Atolls1

The marine green alga Caulerpa bikinensis W. R. Taylor was described as a new species in 1950 from dredged specimens (37–57 m depth) from Bikini Atoll and Rongelap Atoll in the Marshall Islands. Its relative rareness in collections from waters less than 30 m deep from these atolls indicated that it favored the mesophotic coral ecosystem (MCE) at depths of 30–150 m. Published and unpublished records of this species over the past 70 years show its habitat preference on the seaward slopes of atolls and in lagoons. Observations were based on collections from Pacific atolls of the Marshall Islands, Tuamotu Islands, Chuuk State in the Federated States of Micronesia, Cook Islands, and Johnston Atoll, and on the deep lagoonal reefs of Palau. Caulerpa bikinensis has also been recorded in shallow waters 1 m deep in dark microcavities on lagoonal pinnacles at Takapoto Atoll (Tuamotu Islands) and in Chuuk Lagoon, and 2 m deep at Raroia Atoll (Tuamotu Islands). Caulerpa bikinensis favors the deeper depths of the MCE for its low light intensity rather than its cooler temperature, and definitely shows a strong affinity to the high energy seaward slopes of calcareous Pacific atolls.

DNA barcoding of coral reef fishes from Chuuk State, Micronesia

The fish diversity of Chuuk Micronesia is currently under threat due to rapid changes in the coral reef ecosystem. Thus, accurate fish identification using DNA barcodes is fundamental for exploring species biodiversity and resource protection. In this study, we analyzed 162 fish mitochondrial DNA cytochrome c oxidase I (COI) barcodes from Chuuk Micronesia. Consequently, we identified 95 species from 53 genera in 26 families and seven orders. The average Kimura 2-parameter genetic distances within species, genera, families, and orders were calculated as 0.17%, 11.78%, 15.63%, and 21.90%, respectively. Also, we have utilized DNA barcodes to perform genetic divergence and phylogenetic analysis of families recognized as dominant groups in Chuuk State. Our findings confirm that DNA barcodes using COI are an effective approach in identifying coral reef fish species. We anticipate that the results of this study will provide baseline data for the protection of coral reef fish biodiversity at Chuuk Micronesia.

Long-Term Food Consumption Survey on Piis-Paneu Island, Chuuk State, the Federated States of Micronesia

Long-Term Food Consumption Survey on Piis-Paneu Island, Chuuk State, the Federated States of Micronesia

Vaccination Coverage Among Children Aged 2 Years - U.S. Affiliated Pacific Islands, April-October, 2016.

Vaccine-preventable diseases (VPDs) cause substantial morbidity and mortality in the United States Affiliated Pacific Islands (USAPI).* CDC collaborates with USAPI immunization programs to monitor vaccination coverage. In 2016, † USAPI immunization programs and CDC piloted a method for estimating up-to-date status among children aged 2 years using medical record abstraction to ascertain regional vaccination coverage. This was the first concurrent assessment of childhood vaccination coverage across five USAPI jurisdictions (American Samoa; Chuuk State, Federated States of Micronesia [FSM]; Commonwealth of the Northern Mariana Islands [CNMI]; Republic of the Marshall Islands [RMI]; and Republic of Palau).§ Differences in vaccination coverage between main and outer islands¶ were assessed for two jurisdictions where data were adequate.** Series coverage in this report includes the following doses of vaccines: ≥4 doses of diphtheria and tetanus toxoids and acellular pertussis vaccine (DTaP); ≥3 doses of inactivated poliovirus vaccine (IPV); ≥1 dose of measles, mumps, and rubella vaccine (MMR); ≥3 doses of Haemophilus influenzae type B (Hib) vaccine; ≥3 doses of hepatitis B (HepB) vaccine; and ≥4 doses of pneumococcal conjugate vaccine (PCV); i.e., 4:3:1:3:3:4. Coverage with ≥3 doses of rotavirus vaccine was also assessed. Completion of the recommended series of each of these vaccines†† was <90% in all jurisdictions except Palau. Coverage with the full recommended six-vaccine series (4:3:1:3:3:4) ranged from 19.5% (Chuuk) to 69.1% (Palau). In RMI and Chuuk, coverage was lower in the outer islands than in the main islands for most vaccines, with differences ranging from 0.9 to 66.8 percentage points. Medical record abstraction enabled rapid vaccination coverage assessment and timely dissemination of results to guide programmatic decision-making. Effectively monitoring vaccination coverage, coupled with implementation of data-driven interventions, is essential to maintain protection from VPD outbreaks in the region and the mainland United States.

Otsuka, Y. and Yamamoto, S. eds.: Ethnography of Piis-Paneu Island, Chuuk State, the Federated States of Micronesia

Otsuka, Y. and Yamamoto, S. eds.: Ethnography of Piis-Paneu Island, Chuuk State, the Federated States of Micronesia

Characterization of the coccoid cyanobacterium Myxosarcina sp. KIOST-1 isolated from mangrove forest in Chuuk State, Federated States of Micronesia

Mangrove forests are known to be inhabited by diverse symbiotic cyanobacterial communities that are capable of N2 fixation. To investigate its biodiversity, root sediments were collected from a mangrove forest in Chuuk State, Federated States of Micronesia (FSM), and an entangled yellow-brown coccoid cyanobacterium was isolated. The isolated cyanobacterium was reproduced by multiple fission and eventually produced baeocytes. Phylogenetic analysis revealed that the isolate was most similar to the genera Myxosarcina and Chroococcidiopsis in the order Pleurocapsales. Compositions of protein, lipid and carbohydrate in the cyanobacterial cells were estimated to be 19.4 ± 0.1%, 18.8 ± 0.4% and 31.5 ± 0.1%, respectively. Interestingly, total fatty acids in the isolate were mainly composed of saturated fatty acids and monounsaturated fatty acids, whereas polyunsaturated fatty acids were not detected. Based on the molecular and biochemical characteristics, the isolate was finally classified in the genus Myxosarcina, and designated as Myxosarcina sp. KIOST-1. These results will contribute to better understanding of cyanobacterial biodiversity in the mangrove forest in FSM as well as the genus Myxosarcina, and also will allow further exploitation of its biotechnological potential on the basis of its cellular characteristics.

New Records of Butterflies (Lepidoptera) from the Federated States of Micronesia with Remarks on Geographic Variation inHypolimnas bolina(Linnaeus)

Abstract New locality records are given for 10 species of butterflies from 10 islands and island groups (atolls) within the Federated States of Micronesia (FSM). All the species recorded are widespread in the Pacific and in many cases farther afield. We report the first record of Badamia exclamationis from Kosrae (the second for the FSM) and the first record of Catopsilia pomona from Chuuk State. Danaus plexippus is intermittently distributed in the FSM but often observed where the introduced ornamental Calotropis gigantea is common. Hypolimnas bolina was one of the most frequently encountered species during this study. The extent of variation in coloration and pattern within local populations of H. bolina in the FSM and adjacent areas of Oceania suggests that use of sub-species names is probably unwarranted.

Dietary Patterns and Food Consumption in the Federated States of Micronesia::A Case Study Conducted on Piis-Paneu Island, Chuuk Atoll, Chuuk State

Dietary Patterns and Food Consumption in the Federated States of Micronesia::A Case Study Conducted on Piis-Paneu Island, Chuuk Atoll, Chuuk State

Mass poisoning after consumption of a hawksbill turtle, Federated States of Micronesia, 2010.

Marine turtles of all species are capable of being toxic. On 17 October 2010, health authorities in the Federated States of Micronesia were notified of the sudden death of three children and the sickening of approximately 20 other people on Murilo Atoll in Chuuk State. The illnesses were suspected to be the result of mass consumption of a hawksbill turtle (Eretmochelys imbricata). An investigation team was assembled to confirm the cause of the outbreak, describe the epidemiology of cases and provide recommendations for control. We conducted chart reviews, interviewed key informants, collected samples for laboratory analysis, performed environmental investigations and conducted a cohort study. Four children and two adults died in the outbreak and 95 others were sickened; 84% of those who ate the turtle became ill (n=101). The relative risk for developing illness after consuming the turtle was 11.1 (95% confidence inteval: 4.8-25.9); there was a dose-dependent relationship between amount of turtle meat consumed and risk of illness. Environmental and epidemiological investigations revealed no alternative explanation for the mass illness. Laboratory testing failed to identify a causative agent. We concluded that turtle poisoning (also called chelonitoxism) was the cause of the outbreak on Murilo. The range of illness described in this investigation is consistent with previously reported cases of chelonitoxism. This devastating incident highlights the dangers, particularly to children, of consuming turtle meat. Future incidents are certain to occur unless action is taken to alter turtle-eating behaviour in coastal communities throughout the world.

Reptiles of Lukunor Atoll, Mortlock Islands, Chuuk State, Federated States of Micronesia

Sixteen species of reptiles (two sea turtles, seven geckos, six skinks, and one monitor lizard) are recorded from Lukunor Atoll, Federated States of Micronesia. None is endemic to the atoll, and nearly all are widespread in Micronesia, and in many cases well beyond. The gecko Perochirus ateles has the highest incidence of occurrence, being recorded on 17 of the 18 islands, followed by the skink Lamprolepis smaragdina (14 islands), and the gecko Gehyra oceanica (13 islands). The skinks Emoia caeruleocauda and E. impar were among the most common lizards wherever they occurred on the atoll but were observed on only eight and six of the islands, respectively, and occurred together on only two of them. The Pacific monitor, Varanus indicus, was introduced during the Japanese administration, and the common house gecko, Hemidactylus frenatus, probably sometime after World War II. Origins of the other species are less certain; some possibly arrived by natural dispersal and others assisted by humans.

Island impressions of Typhoon Owen: Interviews with Nómwiin islanders and photographs

Abstract Over Easter 2012, Rebecca Hofmann travelled to Nómwiin, an outer atoll of Chuuk State in the Paafeng Islands (literally ‘lying to the north’, also known as Hall Islands after the first European to have encountered them). This special article contains some of her interviews with Nómwiin islanders, and photographs.

Hexabromobenzens 농후 배양에 따른 해면(Axinella sp.) 공생 미생물의 군집구조 변화

할로겐화 또는 탈할로겐화에 관여하는 미생물을 특정하고자 해양의 주된 할로겐화합물 생산자인 해면 공생미생물의 군집구조에 미치는 HBB (hexabromobenzene)의 영향을 밝히고자 했다. 혐기 marine broth 2216에서 100ppm HBB첨가 유무에 관계없이 검출된 균주들은 산호나 해면에서 유래한 클론들과 높은 유사도를 보였으며 그 중 Deltaproteobacteria에 속하는 Desulfovibrio marinisediminis와 99% 유사도를 보이는 클론이 우점하는 것으로 나타났다. Clostridia계통의 Fusibacter paucivorans와 유사도가 높은 클론과 Lentisphaerae에 속하는 균주들은 HBB에 의해 감소하는 반면 Clostridia계통의 Vallitalea guaymasensis와 유사도가 높은 균주들은 HBB가 있는 경우에만 검출되었다. 알려진 균주들과의 비교 결과로 볼 때 D. marinisediminis 및 V. guaymasensis 계통의 균주들이 할로겐화 및 탈할로겐화에 관여하는 것으로 추정된다. Bacteria associated with marine sponges seemed to be concerned in halogenation/dehalogenation process of natural compounds. In the present study, the effect of hexabromobenzene (HBB) on the community structure of bacteria associated with a marine sponge Axinella sp. from Chuuk State under anaerobic condition was investigated. Regardless of 100 ppm HBB, most of detected microorganisms displayed high similarity with clones reported from coral or sponges. Amongst, Desulfovibrio marinisediminis like clones were dominant. Clones affiliated with Lentisphaerae and Fusibacter paucivorans (Clostridia) were detected at the conditions without HBB but clones affiliated with Vallitalea guaymasensis (Clostridia) increased its proportion with HBB. From these results and previous reports clones affiliated with D. marinisediminis and V. guaymasensis seemed to be concerned in halogenation/dehalogenation process.

Investigating an outbreak of acute fever in Chuuk, Federated States of Micronesia.

In September 2012, there was an unexpected increase of acute febrile illness (AFI) in Chuuk State of the Federated States of Micronesia. At the same time, dengue outbreaks were occurring in two of the Federated States of Micronesia's other three states. The cause of AFI was suspected to be dengue; however, by the end of October, only one of 39 samples was positive for dengue. The objective of the investigation was to establish the cause of the outbreak. A line list was created and data analysed by time, place, person and clinical features. Reported symptoms were compared with the published symptoms of several diagnoses and laboratory testing undertaken. Of the 168 suspected cases, 62% were less than 20 years of age and 60% were male. The clinical features of the cases were not typical for dengue but suggestive of respiratory illness. Nasopharyngeal swabs were subsequently collected and found to be positive for influenza. Public health measures were undertaken and the AFI returned to expected levels. Clinical diagnosis of acute febrile illness (AFI) can often be difficult and misleading. This can mean that opportunities for preventive measures early on in an outbreak are missed. In any outbreak, descriptive epidemiological analyses are valuable in helping to ascertain the cause of the outbreak.

Suvanine analogs from a Coscinoderma sp. marine sponge and their cytotoxicities against human cancer cell lines.

Nine suvanine analogs including suvanine phenethylammonium salt and two new compounds were isolated from the marine sponge Coscinoderma sp., collected from Chuuk State, Federated States of Micronesia. The structures of the new compounds were elucidated by 2D NMR and HRMS analyses. Suvanine and a new analog exhibited weak but selective cytotoxicity against colon (HCT-15), lung (NCI-H23), stomach (NUGC-3), and prostate (PC-3) cancer cell lines.

Phenol content, antioxidant and tyrosinase inhibitory activity of mangrove plants in Micronesia

ObjectiveTo find out and compare the in vitro antioxidant and tyrosinase inhibitory activities of two species of mangrove plants. MethodsMangrove samples were harvested at the shoreline on the island of Weno, Chuuk State in Micronesia. The phenol content, antioxidant activity (based on DPPH-free radical scavenging) and tyrosinase inhibitory activity in different tissues (leaves, barks and roots) of Rhizophora stylosa (R. stylosa) and Sonneratia alba (S. alba), collected from the island of Weno. ResultsTotal phenol content ranged from 4.87 to 11.96 mg per g of freeze dried samples. The highest antioxidant activity was observed in R. stylosa bark (85.5%). The highest tyrosinase inhibitory activity was found in S. alba bark. Also, total phenol content and antioxidant activity were higher in methanol extracts than in aqueous extracts. ConclusionsTaken together, the results of this study proved that mangroves can be excellent sources of antioxidant compounds.

Ochrovirga pacifica gen. nov., sp. nov., a novel agar-lytic marine bacterium of the family Flavobacteriaceae isolated from a seaweed.

A strain designated as S85(T) was isolated from a seaweed collected from coastal area of Chuuk State in Micronesia. The strain was gram-negative, rod-shaped, and non-motile and formed yellow colonies on the SWY agar (0.2% yeast extract and 1.5% agar in seawater) and Marine agar 2216. The strain grew at pH 5-9 (optimum, pH 8), at 15-40°C (optimum, 25-28°C), and with 1-9% (w/v) NaCl (optimum, 3%). The phylogenetic analysis based on 16S rRNA gene sequence showed that strain S85(T) was related to Lutibacter litoralis CL-TF09(T) and Maritimimonas rapanae A31(T) with 91.4% and with 90.5% similarity, respectively. The dominant fatty acids were iso-C15:0, iso-C15:0 3-OH and iso-C17:0 3-OH, C16:0 3-OH and summed feature 3 (C16:1 ω7c and/or iso-C15:0 2-OH). The major isoprenoid quinone was MK-6. The DNA G+C content of the type strain was 34.6mol%. The major polar lipids were phosphatidylethanolamine, an unknown glycolipid and two unknown polar lipids. Based on this polyphasic taxonomic data, strain S85(T) stands for a novel species of a new genus, and we propose the name Ochrovirga pacifica gen. nov., sp. nov. The type strain of O. pacifica is S85(T) (=KCCM 90106 =JCM 18327(T)).

Bacillus solimangrovi sp. nov., isolated from mangrove soil

Two novel bacterial strains, GH2-4T and GH2-5, were isolated from mangrove soil near the seashore of Weno island in Chuuk state, Micronesia, and were characterized by a polyphasic approach. The two strains were strictly aerobic, Gram-staining-positive, motile, endospore-forming rods that were catalase- and oxidase-positive. Colonies were circular, convex, stringy and transparent yellowish (GH2-4T) or opaque whitish (GH2-5). The 16S rRNA gene sequences of the two isolates were identical. The most closely related strains in terms of 16S rRNA gene sequence similarity were Bacillus kochii WCC 4582T, B. horneckiae DSM 23495T, B. azotoformans LMG 9581T, B. cohnii DSM 6307T and B. halmapalus DSM 8723T (95.6, 95.4, 95.4, 95.2 and 95.2% similarity, respectively). The partial groEL sequence of strain GH2-4T was identical to that of strain GH2-5 and showed <85% similarity to those of the most closely related strains. The isolates grew at pH 5-12 (optimal growth at pH 9), at 10-40 °C (optimum 30-35 °C) and at 0-9% (w/v) NaCl (optimum 1-3% NaCl). The cell-wall peptidoglycan of strains GH2-4T and GH2-5 contained meso-diaminopimelic acid and cell-wall hydrolysates contained ribose as a major sugar. The DNA G+C content was 36 mol%, and DNA-DNA relatedness between the isolates and five related reference strains was 20-24%. Strain GH2-4T exhibited 81% DNA-DNA relatedness with strain GH2-5. The major cellular fatty acids of both strains were iso-C15:0, iso-C16:0, iso-C14:0 and anteiso-C15:0 and the predominant menaquinone was MK-7. On the basis of the evidence from this polyphasic study, strains GH2-4T and GH2-5 (=KCTC 33143=JCM 18995=DSM 27084) represent a novel species of the genus Bacillus, for which the name Bacillus solimangrovi sp. nov. is proposed; the type strain is GH2-4T (=KCTC 33142T=JCM 18994T=DSM 27083T).

North-eastern range extension of the anemone Stichodactyla haddoni to the Marshall Islands represents a new record of host use by the endemic anemonefish Amphiprion tricinctus

Amphiprion tricinctus is an anemonefish endemic to the Marshall Islands that was previously reported to inhabit four species of sea anemone. Underwater visual surveys in 2009 and 2010 located five individuals of the anemone Stichodactyla haddoni in the shallow lagoon of Majuro Atoll. This is the first record of S. haddoni in the Marshall Islands and a significant north-eastern range extension by 2200 km from its nearest record in Chuuk State, Federated States of Micronesia. Stichodactyla haddoni was inhabited by juvenile and adult A. tricinctus. This report is the first to describe a symbiotic relationship between A tricinctus and S. haddoni. The number of host anemone species inhabited by A. tricinctus now extends to five.

Mosquitoes collected on Weno Island, Romanum Island and Piis-Paneu Island, Chuuk State, the Federated States of Micronesia (Diptera: Culicidae)

Mosquito larval surveys were carried out on Weno Island, Romonum Island and Piis Island in August 2011. Larvae were collected from 133 natural and artificial habitats. A total of 1,761 larvae belonging to nine species including one unidentified species were collected. On Weno Island, eight species, Aedes hensilli， Ae. albopictus， Ae. lamelliferus, Aedes sp.， Culex quinquefasciatus， Cx. carolinensis， Cx. annulirostris and Lutzia vorax, were collected. On Romonum Island， four species, Ae. scutoscriptus， Ae. hensilli， Cx. quinquefasciatus and Cx. carolinensis were collected. On Piis Island, six species, Ae. scutoscriptus， Ae. hensilli， Aedes sp.， Cx. quinquefasciatus， Cx. carolinensis and Cx. annilirostris, were collected. Distributions of Ae. hensilli and Ae. albopictus were confirmed in this survey. To prevent the outbreak of dengue fever, environmental management should focus on the destruction, alternation, disposal or recycling of containers that produce the greater number of adult Aedes mosquitoes.