Planktonic Research Articles

Phytoplankton Saprobity as Pollution Bioindicator: A Study of Genera Chaetoceros in Port of Tanjung Emas Waters, Semarang

Water fertility is an assessment of the condition of organism diversity in relation to aquatic ecosystems. PTES (Port of Tanjung Emas, Semarang) is a major port in Java Sea waters and a domestic port for commercial vessels. Its water condition is influenced by the activities of both commercial and fishing vessels. This research applied a descriptive method with cluster sampling, including a group of samples in the port pool and samples from outside the port pool as a control station (comparator). The research aimed to analyze pla nkton fertility through the analysis of plankton abundance (N) and analyze factors that support the fertility of the waters, such as physicochemical parameters. In this research, diatoms ( Bacillariophyceae ) were found as a class that dominated in the waters with a dominance rate of 95%, meaning that the waters were in β-mesosaprobic condition (moderately polluted). The novelty of this research was the finding of toxic Chaetoceros , which dominated in the waters, resulting in the disappearance of other genera and lower organism abundance and diversity at a higher level. This abundance was a bioindicator that triggered heavy pollution (α-mesosaprobic). Regression analysis showed that phytoplankton abundance was determined by brightness, nitrate, turbidity, and zooplankton abundance. Using factor analysis, there were five factors that affected the total saprobic index (TSI); the largest factor was influenced by the first components (41.49%), including salinity, brightness, temperature, pH, DO, nitrate, and SI. Keywords: Port of Tanjung Emas, water fertility, total saprobic index, factor analysis, physicochemical parameters. https://doi.org/10.55463/issn.1674-2974.50.4.11

The Efficacy of Taurolidine Citrate Solution v Heparin Lock Solution Instilled in Catheter Lumens of End Stage Renal Disease

Background: Hemodialysis patients with end-stage renal illness use a tunnelled central vein catheter for vascular access. Heparin with a preservative, in contrast, exhibits inferior antibacterial effects against biofilm and plank tonic bacteria. Aim: To evaluate the effectiveness of taurolidine citrate solution versus heparin lock solution when infused into the catheter lumens of hemodialysis patients with end-stage renal illness. Study design: Randomized clinical trial Place and duration of study: Hemodialysis Unit, King Fahad Specialist Hospital, Buraidah, Saudi Arabia from 11th December 2018 to 10th June 2019. Methodology: One hundred and fourteen patients on hemodialysis aged 40-70 years with end stage renal disease with Glomerular filtration rate (GFR) less than 15 mL/min, on maintenance hemodialysis through tunnelled dialysis catheter dependent for at least 6 months and patent catheters were selected and randomized into two equal groups by using sealed opaque envelopes bearing a tag of Heparin group and citrate-taurolidine group. Patients were excluded from the study if they had a catheter site infection or an infection unrelated to a catheter that was on antibiotic therapy or had positive blood cultures within two weeks of enrollment. Every two weeks and at the time the catheter was removed, blood cultures were routinely obtained from the catheter lumen to look for bacterial colonization. At the conclusion of six months of hemodialysis, the CRI was assessed. All instances of infections caused by catheters were documented. Results: Incidence of catheter related infection occurred in 5 (8.8%) patients who underwent Heparin group while none of the patient (0%) of taurolidine/citrate group suffered with catheter related infection. This data reveals significantly high incidence of CRI in Heparin group (p=0.029) and significantly high efficacy of taurolidine/citrate group over Heparin group. Conclusion: Efficacy of taurolidine citrate solution is superior versus heparin lock solution instilled in the catheter lumens of patients on hemodialysis. Keywords: Catheter, Infection, Renal disease, Hemodialysis

CORRELATE BETWEEN BIOFILM FORMATION AND AZOLE ANTIFUNGAL SUSCEPTIBILITY AGAINST PLANKTONIC AND SESSILE CANDIDA ALBICANS CLINICAL ISOLATES

Objective: To assess the correlation between biofilm formation and azole antifungal susceptibility against plank tonic and sessile clinical isolates of C.albicans.
 Study Design: Prospective observational study.
 Place and Duration of Study: Combined Military Hospital Peshawar, from Jun 2016 to Sep 2017.
 Methodology: All standard microbiological procedures were carried out according to latest Clinical & laboratory standard institute (CLSI) guidelines. After gram staining and presumptive identification on CHRO Magar Candida, the isolates were biochemically identified by API AUX Candida as C.albicans. Planktonic antifungal susceptibility was carried out by Kirby Bauer disk diffusion method on 300 C.albicans isolates. Broth microdilution method was used to determine Minimum inhibitory concentration (MICs) of plank tonic cells and micro titer assay was used for assessment of biofilm formation by C.albicans.
 Results: In planktonic antifungal susceptibility, fluconazole was susceptible against 195 (65%) and voriconazole against 241 (80%) C. albicans isolates. C. albicans was found susceptible dose dependent (SDD) to fluconazole in 28 (9%) and to voriconazole in 21 (7%) isolates. Seventy-seven (26%) and 38 (13%) C.albicans isolates were found fluconazole and voriconazole resistant, respectively. Sessile antifungal susceptibility was carried out through broth micro dilution method in which 160 (53%) were susceptible, 42 (14%) were susceptible dose dependent SDD and 98 (33%) were resistance to voriconazole, and 161 (54%) were susceptible, 36 (12%) were SDD and 103 (34%) were found resistant to fluconazole. Biofilm forming isolates of C.albicans were observed to be 285 (95%).The p-value is highly significance i.e. <0.01 between......

Understanding the feeding ecology of Cynoglossus joyneri in Haizhou Bay based on stable isotope analysis.

We analyzed the feeding ecology of Cynoglossus joyneri by carbon and nitrogen stable isotope analysis based on the samples collected from the bottom trawl surveys during spring and autumn of 2018 in Haizhou Bay, China. The results showed that the δ13C and δ15N values of C. joyneri ranged from -20.75‰ to -15.91‰ and from 5.98‰ to 12.02‰, respectively. The mean values of the δ13C and δ15N were (-17.79±1.00)‰ and (9.37±1.33)‰, respectively. There was a significantly negative correlation between the δ13C values and standard length and a positive correlation between the δ15N values and standard length. The mean trophic level of C. joyneri was (3.43±0.97). There was a significantly positive correlation between the trophic level and standard length. The dominant prey groups of C. joyneri were fish, crabs, shrimps, mollusca, polychaeta, plankton and particle organic matter (POM). The trophic contribution of shrimps was the highest among these prey groups. The trophic contribution of fish, crabs and shrimps was higher in autumn than those in spring. This study would help to understand the role of C. joyneri in the material cycling and energy flow in Haizhou Bay ecosystem, and provide scientific basis for the protection and rational utilization of this species.

Assessment of Environmental Parameters in Pre- and Post-Monsoons at Chabahar Bay, Gulf of Oman

This study is the first investigation to assess the variations of physical and chemical characteristics and biodiversity of planktons in offshore water column and chlorophyll-a and b, during the two monsoons at Chabahar Bay, to evaluate the water quality. To this end, 27 surface water samples in pre-monsoon (May, 2012) and totally 60 surface and deep water samples in post-monsoon (December, 2012) were collected from 9 and 10 stations at depths between 3.8 to 13.6 m in Chabahar Bay, respectively. The results showed that water salinity and pH with low variations were relatively higher in post-monsoon. The averages of water alkalinity levels in pre- (2.42±0.02 mmol H+/kg) and post- (2.44±0.01 mmol kg-1) monsoons were comparable to that of oceanic surface water (2-2.5 mmol H+/kg). In this study, 66 phytoplankton genus and species belonging to 13 groups were identified in pre-monsoon. Results demonstrated that nutrients were at higher levels inside the Chabahar Bay. Moreover, the physicochemical parameters of water samples were investigated and compared with international standards and data from other marine ecosystems. The results indicated that the water quality falls within the stipulated range of acceptability and sampling area can be classified as a good, stable, and healthy aquatic ecosystem.

Activities of nine antifungal agents against Candida auris biofilms.

Candida auris is a newly described multidrug-resistant fungal pathogen associated with biofilm formation and severe infections with high mortality. To study the activities of fluconazole, itraconazole, posaconazole, voriconazole, deoxycholate and liposomal amphotericin B, anidulafungin, caspofungin and micafungin against Cauris biofilms and planktonic cells. Cauris strains originating from 5 clades (South Asian, East Asian, African, South American and Iranian) were tested for biofilm production by safranin staining of the extracellular matrix polysaccharide structure as well as biofilm (BF) and planktonic (PLK) antifungal susceptibility to nine antifungal agents using the XTT reduction assay. Candida auris isolates produced mature BF as compared to non-Cauris control (Candida albicans and Candida parapsilosis) strains. Four C auris isolates exhibited relatively high MIC's for fluconazole (32-128mg/L for PLK MIC and 128-1024mg/L for BF MIC) as compared to the Iranian strain that had PLK and BF MIC's 0.5 and 16, respectively. Itraconazole, posaconazole and voriconazole had relatively low PLK MICs but high BF MICs. A similar pattern was observed with echinocandins; relatively low PLK MIC (0.06-4mg/L) but quite high BF MICs (4-2048mg/L). While all isolates exhibited relatively low PLK MICs (0.06-4mg/L) for both amphotericin B formulations, liposomal amphotericin B showed higher MICs compared to deoxycholate amphotericin B against Cauris BF. Triazoles, echinocandins and liposomal amphotericin B appear to have less activity against Cauris biofilms than deoxycholate amphotericin B. Our in vitro model provides evidence for intrinsic Cauris biofilm resistance to antifungal agents.

Sedimentary Diatom Records Reveal the Succession of Ecosystem in Lake Xihu, Dali over the Past 50 Years

In recent decades, intense human activities have caused a decline in many lake ecosystems in Yunnan Province, rendering the transformation of the lake from a clear macrophyte-dominated state to a turbid phytoplankton-dominated state. Improved understanding of the ecological changes in lake ecosystem has significant implications for management. In this study, a small lake in Dali Prefecture of Yunnan Province, i.e., Lake Xihu, was selected. Combined with diatom records and physicochemical proxies from the lake sediments, this paper focuses on the long-term ecological changes in Lake Xihu, Dali since the mid-1960s. The results show that the Lake Xihu, Dali has undergone a significant shift in stable states over the past 50 years. Prior to 2000, the benthic-epiphytic species (i.e., Cocconeis placentula, Staurosira construens, Gomphonema angustum, and Achnanthidium minutissimum) dominated in diatom assemblages, indicating oligotrophic conditions; since 2000, benthic-epiphytic species (i.e., Encyonopsis microcephala and Navicula cryptocephala) and planktonic species (i.e., Cyclotella atomus, Cyclotella meneghiniana, Stephanodiscus hantzschii, and Aulacoseira granulata) dominated successively, indicating mesotrophic to eutrophic conditions. Principal component analysis based on the diatom assemblages in temporal scale showed the response of diatoms succession to nutrients. Redundancy analysis also confirmed that nutrient enrichment was the main driving force for the succession of diatom assemblages in Lake Xihu, Dali. In the past 50 years, climate change and human activities (i.e., agricultural reclamation, fertilization, animal husbandry, and fishery) have enhanced the accumulation of nutrients in the lake. The continuous loading of nutrients promoted the propagation of planktonic algae, and also the productivity of the lake, rendering the transformation to a turbid phytoplankton-dominated state.

Microbiological Analysis of Punch Biopsies of Tonsillar Crypts of Patients with Chronic Tonsillitis

Statement of the Problem: Medicine identified that recurrent and chronic infections of palatine tonsils are exacerbated by the creation of biofilms by microorganisms in the wet and warm folds of the tonsils which act as a repository of infection (Abu Bakar et al., 2018). Although 99% of all bacteria exist within biofilms, it is the planktonic state and swab samples from tonsillar surface that historically have received the attention. This is likely due to the fact that disease - causing bacteria is grown more rapidly in the planktonic form and it is much easier to sample fluids as opposed to surfaces (Snyder et al., 2009). Clinical Practice: At Pauls Stradiņs Clinical University Hospital was decided to microbiologically analyze the punch biopsy samples of tonsillar crypts of patients with chronic tonsillitis. Patients who met Paradise criteria were admitted to the Department of Otorhinolaryngology for tonsillectomies. Biopsies were taken before operations. Pathogenic bacteria of biopsy samples were tested for antibacterial susceptibility and biofilm producing ability. Results of the microbiological analysis revealed variety of pathogenic bacteria with resistance to common antibiotics un strong biofilm formation ability. Conclusion & Significance: Isolated pathogens from tonsillar crypts were resistant to antibiotics which are used to treat tonsillitis. Isolated pathogens from tonsillar crypts were weak, moderate or strong biofilm producers. Only 20 % of strains did not produce biofilm. During further studies the role of strong biofilm producers has to be evaluated as biofilm production plays a key role in the pathogenesis of chronic tonsillitis.

Drivers of water pollution and evaluating its ecological stress with special reference to macrovertebrates (fish community structure): a case of Churni River, India.

The focus of this study is to measure ecological stress of Churni River based on the estimates of dissolved oxygen (DO), pH, biological oxygen demand (BOD), chemical oxygen demand (COD), nutrients imbalances of dissolved inorganic nitrogen or DIN (NO3- N and NO2- N) and dissolved inorganic phosphate or DIP (PO43-). The present water quality measured in terms of overall index of pollution (OIP), eutrophication index (EI), organic pollution (OPI) and water pollution indexes for ecological status (WPI) portrays that the river is polluted having a high concentration of BOD, COD, nutrients (DIP and DIN) and a very low concentration of DO. Fish community structure taken as most sensitive indicator of ecological stress of water pollution depicts that out of 44 species, 28 fish species (63.63%) comprising 20.0% planktivore (PL), 9.09% benthic feeder (BE), 18.18% omnivorous (OM) and 15.90% carnivorous (CA) at Majhdia and 21 fish species (47.72%) comprising 18.18% PL, 4.59% BE, 13.63% OM and 11.36% CA at Ranaghat have been disappeared. The present investigation has found that anthropogenic interventions like disposal of industrial effluents and agricultural run-off from on-bed and off bed land use are the main drivers of the pollution. Furthermore, natural forcing in the form of neotectonic movements and monsoon regimes has intensified the problem.

Advancing science from plankton to whales—Celebrating the contributions of James J. McCarthy

Advancing science from plankton to whales—Celebrating the contributions of James J. McCarthy

Extensive genetic differentiation between recently evolved sympatric Arctic charr morphs.

The availability of diverse ecological niches can promote adaptation of trophic specializations and related traits, as has been repeatedly observed in evolutionary radiations of freshwater fish. The role of genetics, environment, and history in ecologically driven divergence and adaptation, can be studied on adaptive radiations or populations showing ecological polymorphism. Salmonids, especially the Salvelinus genus, are renowned for both phenotypic diversity and polymorphism. Arctic charr (Salvelinus alpinus) invaded Icelandic streams during the glacial retreat (about 10,000 years ago) and exhibits many instances of sympatric polymorphism. Particularly, well studied are the four morphs in Lake Þingvallavatn in Iceland. The small benthic (SB), large benthic (LB), planktivorous (PL), and piscivorous (PI) charr differ in many regards, including size, form, and life history traits. To investigate relatedness and genomic differentiation between morphs, we identified variable sites from RNA‐sequencing data from three of those morphs and verified 22 variants in population samples. The data reveal genetic differences between the morphs, with the two benthic morphs being more similar and the PL‐charr more genetically different. The markers with high differentiation map to all linkage groups, suggesting ancient and pervasive genetic separation of these three morphs. Furthermore, GO analyses suggest differences in collagen metabolism, odontogenesis, and sensory systems between PL‐charr and the benthic morphs. Genotyping in population samples from all four morphs confirms the genetic separation and indicates that the PI‐charr are less genetically distinct than the other three morphs. The genetic separation of the other three morphs indicates certain degree of reproductive isolation. The extent of gene flow between the morphs and the nature of reproductive barriers between them remain to be elucidated.

Brachionus falcatus and Platyias patulus indicating organic pollution in Ouémé River’s basin, Republic of Benin

Zooplankton is a biological compartment widely used in the bio-monitoring of aquatic ecosystems. It allows early detection of environmental disturbances even before reaching the upper compartments of interest to humans. The present study evaluated the ability of two rotifer species Brachionus falcatus and Platyias patulus to indicate organic pollution in the Oueme River basin. Sampling was done between October 2014 and September 2015. Plankton net of 20 μm mesh size was used. Parameters such as NH 4 + , NO 2 - and PO 4 3- were measured in water and used for the calculation of the Organic Pollution Index (IPO). The results showed that the occurrence of B. falcatus and P. patulus was 96.66% and 81.11%, respectively. Both species were particularly abundant in sites such as Kaboua and Vossa as well as downstream of the basin (Agonlin-lowe and Bonou). These strong abundances are linked to a very strong organic pollution in Kaboua and Vossa then to a high organic pollution at downstream. The least organically polluted station (Kpassa) had the lowest abundance of both species. B. falcatus and P. patulus are therefore two indicator species of organic pollution in the Oueme River’s basin in Benin.

Linalool, citral, eugenol and thymol: control of planktonic and sessile cells of Shigella flexneri

The antimicrobial activity of linalool, citral, eugenol and thymol was determined in growth studies of both planktonic (PC) and biofilm cells (BC) Shigella flexneri. These components were evaluated either in isolation or in combinations using a sequential experimental strategy with Plackett & Burman and central composite rotational designs totaling 47 treatments. The minimum inhibitory concentration for PC was 0.125% (v v−1) for linalool and 0.5% (v v−1) for citral, eugenol and thymol. The biofilm minimum bactericidal concentration was 3 and 1% (v v−1) for linalool and citral, respectively, and 2% (v v−1) for eugenol and thymol. In the mixtures, the minimum concentrations in the efficient assays for PC growth inhibition were 0.0003, 0.0443 and 0.0443% (v v−1), for linalool, citral and thymol, respectively. In the BC, only two assays with concentrations of 0.0558, 0.0558 and 0.319% (v v−1) and 0.035, 0.035 and 0.3999% (v v−1) for linalool, citral and thymol, respectively, inhibited Shigella growth. Synergism was observed among the components, where PC and BC growth inhibition occurred at lower concentrations than those noted individually. The bactericidal effect of the components in microplate was different from the observed in stain steel coupons. Therefore, the obtained model can describe and predict the PC count of S. flexneri in medium with the tested compounds and they could be an alternative for the use in microbiological control in food industry.

Mathematical Modeling of Plankton Biomass Dynamics During the Spring Thermal Bar in Kamloops Lake

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Synergistic Effect of Tryptophan and Erythromycin on Pseudomonas Aeruginosa Biofilm Structure and Dispersal

Pseudomonas aeruginosa is an opportunistic pathogen that is responsible for diseases such as cystic fibrosis (CF) in immunocompromised individuals. Outcome of CF is abnormally thickened mucus that causes problems in patient’s respiratory system. This condition affects 2.5 million people in the UK alone with a high rate of mortality by the age of 40. Various methods of treatment to manage CF by dispersion and disassembly of biofilm have been intensively researched. Since as much as 80% of human bacterial infections are biofilm- associated, many researchers have begun investigating therapies that specifically target the biofilm architecture, thereby dispersing the microbial cells into their more vulnerable, planktonic state. Amongst the current methods of controlling CF, biofilm dissociation by the use of a combination of an amino acid and an antibiotic has been investigated in this research. During this study, biofilm formation by P. aeruginosa PAO1 was observed under aerobic conditions in Luria Broth and M63 minimal media at 37°C for a period of 24 hours. The cultures were treated with two isomeric forms of tryptophan at different concentrations (1 mM, 4 mM, and 8 mM). Dispersal and dissociation of the cells in all cultures were investigated and compared with the control after 24 hours. The D isomer of tryptophan at concentrations of 4 mM and 8 mM showed higher rate of dispersion in comparison to the L isomeric form and the control. The effect of tryptophan varied with the medium that was used for biofilm growth. Extracellular polymeric substances (EPS) were extracted from the treated and untreated biofilm and quantified for their main components. Biofilm treated with tryptophan and erythromycin resulted in nearly 70% loss of EPS components in comparison with the control after 5 days of growth.

Состояние планктонных сообществ и кормовая обеспеченность минтая в северо-западной части Берингова моря в современный период

Состояние планктонных сообществ и кормовая обеспеченность минтая в северо-западной части Берингова моря в современный период

Zooplankton composition in four Reservoirs in Jos, Plateau State, Nigeria

The zooplankton community structure of four reservoirs (Kogingirin, Lamingo, Liberty and Tolemache) in Jos, Plateau State were studied for a period of two years (April 2012 to March 2014) using standard methods. The aim was to identify plankton structure as reference point for the sustainable management of the reservoirs for future developmental plan. The results identified four groups of zooplankton thus: Rotifera (59%), Cladocera (23%), Copepoda (14%) and Protozoan (4%). A total of 10 orders, 30 families and 130 species of zooplankton were collected across the reservoirs. Of this total, 22 species were common across the four reservoirs and 114 new species were identified. The order Ploimida was the most abundant while Brachionidae presented the highest number of family. Results obtained showed that reservoirs on the Plateau are highly resourceful in zooplankton. Keywords: Zooplankton Composition, Reservoirs, Order, Species, Families

Zooplankton composition in four reservoirs in Jos, Plateau State, Nigeria

The zooplankton community structure of four reservoirs (Kogingirin, Lamingo, Liberty and Tolemache) in Jos, Plateau State were studied for a period of two years (April 2012 to March 2014) using standard methods. The aim was to identify plankton structure as reference point for the sustainable management of the reservoirs for future developmental plan. The results identified four groups of zooplankton thus: Rotifera (59%), Cladocera (23%), Copepoda (14%) and Protozoan (4%). A total of 10 orders, 30 families and 130 species of zooplankton were collected across the reservoirs. Of this total, 22 species were common across the four reservoirs and 114 new species were identified. The order Ploimida was the most abundant while Brachionidae presented the highest number of family. Results obtained showed that reservoirs on the Plateau are highly resourceful in zooplankton. Keywords: Zooplankton Composition, Reservoirs, Order, Species, Families

Diversity of freshwater planktons at Haro Dam, Ghatol, Banswara (Rajasthan).

Diversity of freshwater planktons at Haro Dam, Ghatol, Banswara (Rajasthan).

Planktonic and periphytic bdelloid rotifers from Thailand reveal a species assemblage with a combination of cosmopolitan and tropical species

The dispersal pattern of microorganisms has been a debated topic in the last decade, because for microscopic organisms with dispersing stages, biogeographic barriers may not exist and geographic distances may have little effect on the probability of their occurrence. In this study we tested whether a group of microscopic animals, the bdelloid rotifers, sampled in a tropical country, could indeed be cosmopolitan, strictly tropical, and/or have endemic species. We sampled freshwater habitats throughout Thailand in dry and rainy seasons between 2014 and 2016, focusing on permanent water bodies, where the prevalence of species producing resting stages acting as propagules for dispersal should be minimal and thus dispersal limitation should exist, with several species being narrowly distributed. We used traditional morphological identification, geometric morphometric analyses on the shape and size of the jaws, and DNA taxonomy to identify species and to quantify the morphological and genetic distances of Thai ...