Compared to their terrestrial and marine counterparts, little is known about the capacity of freshwater-derived actinomycete bacteria to produce novel secondary metabolites. In the current study, we highlight the disparities that exist between cultivation-independent and -dependent analyses of actinomycete communities from four locations in Lake Michigan sediment. Furthermore, through phylogenetic analysis of strains isolated from these locations, we identified a Streptomyces sp., strain B025, as being distinct from other Streptomyces spp. isolated from sediment. Upon fermentation this strain produced a rare class of eight-membered lactone secondary metabolites, which have been for their antitumor properties. We used spectroscopic and chemical derivitization techniques to characterize octalactin B (1) in addition to its corresponding novel, unnatural degradation product (2).
Bacteria ; Fermentation ; Fresh Water ; Lakes ; Michigan ; Streptomyces*

OBJECTIVE: To investigate the quantity and species distribution of diatoms in Chuanyang River of Pudong new area of Shanghai and provide references for the invesitigation of water body in forensic practice. METHODS: The water samples collected from 15 areas in Chuanyang River of Pudong new area in September 2012 were examined by microscope to identify the species of diatoms. RESULTS: Cyclotella and Pinnularia were found to be the dominant species within the 12 species of diatoms in Chuanyang River, which showed differences in species among the sections of Huangpu River, the center and the East China Sea. CONCLUSION The differences in subsectional distribution of diatom species in Chuanyang River may provide a new foundation for forensic identification in drowning cases especially in the determination of falling location.
China ; Diatoms ; Drowning ; Forensic Medicine ; Fresh Water ; Rivers

The purpose of this study was to investigate the current status of metal pollution in the sediment from rivers, lakes, and streams in active gold mining districts in Ghana. Two hundred and fifty surface sediment samples from 99 locations were collected and analyzed for concentrations of As, Hg, Cr, Co, Cu, Fe, Zn, Pb, Cd, Ni, and Mn using inductively coupled plasma-mass spectroscopy (ICP-MS). Metal concentrations were then used to assess the human health risks to resident children and adults in central tendency exposure (CTE) and reasonable maximum exposure (RME) scenarios. The concentrations of Pb, Cd, and As were almost twice the threshold values established by the Hong Kong Interim Sediment Quality Guidelines (ISQG). Hg, Cu, and Cr concentrations in sediment were 14, 20, and 26 times higher than the Canadian Freshwater Sediment Guidelines for these elements. Also, the concentrations of Pb, Cu, Cr, and Hg were 3, 11, 12, and 16 times more than the Australian and New Zealand Environment and Conservation Council (ANZECC) sediment guideline values. The results of the human health risk assessment indicate that for ingestion of sediment under the central tendency exposure (CTE) scenario, the cancer risks for child and adult residents from exposure to As were 4.18 x 10(-6) and 1.84 x 10(-7), respectively. This suggests that up to 4 children out of one million equally exposed children would contract cancer if exposed continuously to As over 70 years (the assumed lifetime). The hazard index for child residents following exposure to Cr(VI) in the RME scenario was 4.2. This is greater than the United States Environmental Protection Agency (USEPA) threshold of 1, indicating that adverse health effects to children from exposure to Cr(VI) are possible. This study demonstrates the urgent need to control industrial emissions and the severe heavy metal pollution in gold mining environments.
Adult ; Child ; Chromium ; Contracts ; Eating ; Fresh Water ; Ghana ; Hong Kong ; Humans ; Lakes ; Metals ; Mining ; New Zealand ; Risk Assessment ; Rivers ; Spectrum Analysis ; United States Environmental Protection Agency

To know the value of the solubilization method using tissue solubilizer Soluene-350 in diagnosis of drowning, mice (ICR) were drowned artificially with the fresh water of Chungju district. Chlorophyta (or green algae), such as Oocystis and Eudorina, as well as diatoms, such as Diatoma, Synedra and Cyclotella were detected with other algae including Microcystis, Oscillatoria, Trachlomonas, Altenaria and Cephalodella in the water of Daeje-ji(Dae-je pond). This method is useful in detection of green algae and other kinds of algae for diagnosis of drowning in submerged bodies among legal autopsy cases.
Animals ; Autopsy ; Chlorophyta* ; Chungcheongbuk-do* ; Diagnosis* ; Diatoms ; Drowning* ; Fresh Water ; Mice ; Microcystis ; Oscillatoria ; Rivers* ; Water

To understand the distribution of Giardia cysts in drinking water supplies in Seoul, Korea, we collected water samples quarterly at 6 intakes in the Han River, its largest stream and 6 conventional water treatment plants (WTPs) serving drinking water, from 2000 to 2009. Giardia cysts in each of 10 L water were confirmed in 35.0% of intake water samples and the arithmetic mean was 1.65 cysts/10 L (range 0-35 cysts/10 L). The lowest cyst density was observed at Paldang and Kangbuk intakes, and the pollution level was higher at 4 intakes downstream. It seemed that these 4 intakes were under influence of Wangsuk stream at the end of which cysts were found in all samples with the mean of 140 cysts/10 L. The annual mean number of cysts was 0.21-4.21 cysts/10 L, and the cyst level at the second half of the 10 years was about 1/5 of that at first half on average. The cysts were more frequently found in winter, and their mean density was 3.74 cysts/10 L in winter and 0.80-1.08 cysts/10 L in other seasons. All finished water samples collected at 6 WTPs were negative for Giardia in each of 100 L sample for 10 years and cyst removal by physical process was average 2.9-log. It was concluded that conventional water treatment at 6 WTPs of Seoul appears to remove the cysts effectively under the present level of their source water. Domestic wastewater from the urban region could be an important source of Giardia pollution in the river.
Fresh Water/*parasitology ; Giardia/growth & development/*isolation & purification ; Republic of Korea ; Rivers/parasitology ; Seasons ; Water Supply/*analysis

Potamotrygon motoro, also known as the Marble motoro, is a potamodromous freshwater ray native to the basins of the Amazon River. Marble motoros were introduced to South Korea in the 2000s, and, because they are easy to raise, were sold as aquarium fish. The aim of this report is to illustrate a new case involving envenomation by a Marble motoro. A 35-year-old commercial aquarium assistant came to the hospital after being pricked by a Marble motoro. The clinical picture in this case showed acute local pain with minimal systemic manifestations. This patient recovered after receiving symptomatic treatment and wound care. This case of envenomation accentuates the potential for injury among people coming in contact with a venomous Marble motoro.
Adult ; Calcium Carbonate ; Fresh Water ; Humans ; Porphyrins ; Republic of Korea ; Rivers ; Spine ; Venoms

PURPOSE: This study investigated the factors of C. sinensis infection among the residents in vicinity of the Nakdong River and the infection status of fishes in the stream with C. sinensis maetacercaria. METHODS: Selected five regions of the Nakdong River and collected freshwater fishes from the stream to examine their metacercarial infections; and studied the status and causes of C. sinensis infection in 552 residents living within 5 kilometers from the river. RESULTS: Among the 552 residents studied, 13.8% were infected with C. sinensis, and among 379 freshwater fishes of 20 species collected from the five regions, 41 fishes of 8 species were infected with C. sinensis metacercaria. CONCLUSION: In order to prevent human C. sinensis infection and transition to chronic liver ions, we need to develop and apply good programs such as continuous health education, personal hygiene improvement, active medical treatment for those infected with C. sinensis, and residents' voluntarily stop of eating freshwater fishes in the raw state.
Clonorchiasis* ; Clonorchis sinensis ; Eating ; Fishes ; Fresh Water ; Health Education ; Humans ; Hygiene ; Ions ; Liver ; Rivers

This study was performed to investigate the heavy metal contents of freshwater fishes. The samples of 24 species were collected at 7 areas located on the Mankyung River during September in 1987. And then the contents of lead, cadmium, copper and zine were analyzed by atomic absorption spectrophotometer. The results were summarized as follows ; 1. The mean value of lead, cadmium, and copper contents of fishes collected in the downstream were significantly higher than those of upstream. 2. The mean lead content of C. auratus was the highest 1.50+/-0.98 microgram/g in viscera and statistically significant difference from muscle content. 3. The mean cadmium content of C. auratus was the highest 0.087+/-0.054 microgram/g and significantly higher than that of muscle, skeleton and gill. 4. In the copper contents, the viscera of C. auratus was the highest 5.25+/-0.94 microgram/g and significantly higher than that of muscle, skeleton and gill. 5. The mean value of zinc content of C. auratus was shown the order of gill, skeleton, viscera and muscle.
Absorption ; Animals ; Cadmium ; Copper ; Fishes* ; Fresh Water* ; Gills ; Rivers* ; Skeleton ; Viscera ; Zinc

The infection status of Clonorchis sinensis metacercariae (CsMc) was examined in freshwater fish from a highly prevalent site, Wicheon (a branch of Nakdong-gang), which is located in Gunwi-gun, Gyeongsangbuk-do, the Republic of Korea. Total 1,162 fish in 32 species were examined by the artificial digestion method through 6 years. CsMc were detected in 720 (67.5%) out of 1,067 fish (26 spp.) and their density was 610 per fish infected. In the susceptible gobioninid fish group, i.e., Pungtungia herzi, Squalidus gracilis majimae, Squalidus japonicus coreanus, Sarcocheilichthys variegatus wakiyae and Pseudorasbora parva, all of 323 fish were infected with an average of 1,310 CsMc. Total 23 (95.8%) gobioninid fish, i.e., Pseudogobio esocinus, Abbottina springeri, Hemibarbus longirostris, Microphysogobio koreensis, and Microphysogobio jeoni, were infected with 127 CsMc in average. In the acheilognathinid fish (bitterlings) group, the prevalence was 77.0%, and the density was 50 CsMc per fish infected. In the rasborinid fish (chubs) group, i.e., Zacco platypus, Zacco temminckii, Zacco koreanus, and Opsariichthys uncirostris amurensis, 147 (36.5%) out of 403 fish examined were infected with 15 CsMc in average. The susceptibility indices of CsMc were 412 in the overall positive fish group, 1,310 in the gobioninid group-1, 122 in the gobioninid group-2, 38.5 in the acheilognathinid group, and 5.5 in the rasborinid fish group. Conclusively, it was confirmed that CsMc are highly prevalent in fish from Wicheon, and their infection tendency varied according to the subfamily groups in Cyprinidae fish hosts.
Clonorchis sinensis ; Cyprinidae ; Digestion ; Fresh Water ; Gyeongsangbuk-do ; Korea ; Metacercariae ; Methods ; Platypus ; Prevalence ; Republic of Korea ; Rivers

The aim of this study was to conduct a freshwater snail survey in Mae Lao agricultural basin to assess the diversity with a focus on habitat types and their larval trematode infections. Snails were collected and examined in 14 sites of Mae Lao agricultural basin from August 2016 to October 2017. A total of 1,688 snail individuals were collected and classified into 7 families, 8 genera, and 12 species. Snail diversity and habitat types were higher in rice paddies than irrigation canals and streams. The most abundant species was Bithynia siamensis siamensis, representing 54.6% of the sample. Three species of snails act as first intermediate host were found with cercarial infections. They were Filopaludina sumatrensis polygramma, B. s. siamensis, and Melanoides tuberculata. The cercariae were categorized into 7 types; echinostome, monostome, gymnocephalous, virgulate, parapleurolophocercous, pleurolophocercous and megalurous cercariae. Parapleurolophocercous cercariae constituted the most common type of cercariae recovered, contributing 41.2% of all infections in snails. Echinostome metacercariae infections were found in 6 snail species with 7.6% prevalence. In addition, the metacercaria of avian trematode, Thapariella sp. were found in Filopaludina spp. snails and B. funiculata with a prevalence of 0.5%. This is the first report for Thapariella metacercariae in the snail host, B. funiculata, and also confirmed that viviparid and bithyniid snails act as the second intermediate hosts of this trematode. This work will provide new information on the distribution and intermediate host of trematode in this area.
Cercaria ; Ecosystem ; Fresh Water ; Humans ; Metacercariae ; Prevalence ; Rivers ; Snails ; Trematode Infections