La influencia de la materia orgánica y pigmentos de fitoplancton sobre la distribución de bacterias en sedimentos de la Bahía de Kaštela (mar Adriático)

Bacterial abundance, biomass, volume and morphological diversity were studied in sediments collected in the eastern Adriatic Sea (Kaštela Bay) in order to investigate their relationship with changes in environmental parameters. To asses the changes in the investigated parameters on a temporal scale and between sediment layers, the sediment samples were collected monthly in 2002 with a piston corer from the sediment surface to a depth of 10 cm. The concentrations of organic matter (OM), chloroplastic pigment equivalents (CPE), chlorophyll a (chl a) and phaeopigments (PHAEO) were used as indicators of substrate concentrations in sediments. Sediment depth was a significant factor influencing the distribution of bacterial abundance, biomass and volume. Granulometric properties of the sediment had no effect on the distribution of bacteria. Bacterial abundance, biomass and volume were strongly related to the indicators of substrate concentrations on both scales. The accumulation of labile OM in deeper layers also had a profound effect on the size and structure of bacteria. High amounts of OM and the low proportion of labile organic fraction (CPE; chl a and PHAEO) indicate that this environment acts as a sink for accumulation of detrital material.La abundancia, biomasa volumen y la diversidad morfologica bacteriana fueron estudiadas en sedimentos recogidos del este del mar Adriático (bahía de Kaštela) con el objeto de investigar su relación con los cambios de diferentes parámetros ambientales. Para establecer los cambios de los parámetros investigados a escala temporal y entre capas de sedimentos, las muestras de sedimento fueron recogidas mensualmente durante 2002, con un corer de pistón desde la superficie del sedimento hasta la profundidad de 10 cm. La concentración de materia orgánica, pigmentos cloroplastídicos equivalentes (CPE), clorofila a (chl a) y feopigmentos (PHAEO) fueron utilizados como indicadores de la concentración de sustrato en el sedimento. La profundidad del sedimento era un factor significativo en la influencia de la distribución del número de bacterias, biomasa y volumen. Las propiedades granulométricas del sedimento no tenían efecto sobre la distribución de bacterias. La abundancia, la biomasa y el volumen bacteriano estaban fuertemente relacionadas con los indicadores de sustrato en ambas escalas. La acumulación de la materia orgánica lábil en las capas más profundas tambien tenían un gran efecto sobre el tamaño y la estructura bacteriana. Una alta cantidad de materia orgánica y baja proporción de la fracción orgánica lábil (CPE; chl a y PHAEO) indica que estos ambientes actúan como sumideros para la acumulación de material detrítico

Volume, abundance and biomass of sediment bacteria in the eastern mid Adriatic Sea

Bacterial abundance, biomass, cell volume, and morphological diversity were studied in sediment samples collected from the coastal area of the eastern mid Adriatic Sea. Samples from the topmost 10 cm of sediment were taken monthly from January to December 2002. The number of bacteria varied from 3.54 x 109 cells g–1 in July to 8.08 x 109 cells g–1 in September. Biomass was lowest in May (78 µg C g-1) and highest in December (378 µg C g-1). The volume of the bacteria varied markedly with season, fluctuating from 3.87 x 108 µm3 g-1 in May to 3.12 x 109 µm3 g-1 in December. Cells with a volume smaller than 0.1 µm3 accounted for the largest number of bacteria (62%) and cocci comprised 93% of these cells. More than 80% of all rod cells had a volume smaller than 0.5 µm3. The majority of filamentous cells (63%) belonged to the 0.32 µm3 volume class. Rodshaped cells were dominant in terms of volume (45-72%) and biomass (42-72%) and cocci in terms of abundance (52-70%). Cells smaller than 0.5 µm3 made up 88-94% of the bacteria and 68-84% of the biomass in the summer and 6-44% of the bacteria and and 21-81% biomass in the winter

Usporedba metoda protočne citometrije i fluorescentne mikroskopije za brojenje morskih heterotrofnih bakterija

Two direct heterotrophic bacterioplankton counting methods, epifluorescence microscopy (EM) and flow cytometry (FCM) were compared using samples collected in two geographically different oceanic regions, the Adriatic Sea and the English Channel. A statistically significant correlation was found between results obtained by these two methods for samples collected in the Adriatic Sea (r =0.61, n =919, P <0.001) and in the English Channel (r =0.64, n =33, P <0.001). Samples from the Adriatic Sea showed on average 1.16 times higher values obtained by flow cytometry than val- ues estimated by epifluorescence microscopy, while samples from the English Channel showed on average a 0.74 ratio between flow cytometry and epifluorescence microscopy counts. The overall coefficient of variation for epifluorescence microscopy data for samples from the Adriatic Sea and the English Channel was 15.91% and 12.89%, respectively. The flow cytometry method had lower overall coefficient of variation value; for samples collected in the Adriatic Sea it was 3.64%, while for samples collected in the English Channel it was 1.88%Dvije direktne metode za brojanje heterotrofnog bakterioplanktona, epifluorescentna mikroskopija (EM) i protočna citometrija (FCM), uspoređene su koristeći uzorke sakupljene s dva zemljopisno različita morska područja, Jadranskog mora i Engleskog kanala. Između dvije direktne metode brojanja u uzorcima iz Jadran- skog mora (r = 0.61, n = 919, P <0.001) i Engleskog kanala (r = 0.64, n = 33, P <0.001) pronađena je statisti- čki značajna korelacija. U Jadranskom je moru metoda protočne citometrije davala u prosjeku neznatno niže rezultate u odnosu na metodu epifluorescentne mikroskopije, dok je u Engleskom kanalu broj heterotrofnih bakterija dobiven metodom epifluorescentne mikroskopije bio u prosjeku nešto veći u odnosu na protočnu citometriju. Međutim, srednji koeficijent varijacije rezultata dobivenih epifluorescentnim mikroskopom za područje Jadrana iznosio je 15.91%, za područje Engleskog kanala 12.89%, dok je protočna citometrija rezultirala nižim koeficijentima varijacije te je za uzorke iz Jadrana iznosila 3.64%, a za uzorke sakupljene u Engleskom kanalu svega 1.88%. Navedeni rezultati predstavljaju doprinos sagledavanju metode protočne citometrije kao brže, sigurnije i preciznije za brojenje bakterioplanktona u morskom okolišu

Akumulacija indikatorske bakterije Escherichia coli u dagnji (Mytilus galloprovincialis) i kamenici (Ostrea edulis) u eksperimentalnim uvjetima

The simultaneous effects of temperature and salinity on the accumulation of Escherichia coli (E. coli) in mussels (Mytilus galloprovincialis) and oysters (Ostrea edulis) were studied under experimental conditions with different concentrations of E. coli in seawater. The experiments were carried out in 3000 L tanks, within the natural range of temperature (12oC, 18oC and 24oC) and salinity (32 psu and 37 psu) in the coastal areas of the Adriatic Sea. Within the achieved range of E. coli concentrations in seawater (4x10-4.6x103 CFU/100 ml), bacteria accumulated rapidly in the bivalves, reaching the highest concentrations (plateau) after 1 h in mussels and 2 h in oysters. Under the same concentrations of E. coli in seawater, a significantly higher plateau was reached in mussels than oysters. Significant correlations between the E. coli concentration in seawater and bivalves (CR; concentration ratio) were found. The results clearly showed that CR was controlled by temperature and salinity of seawater. Changes in temperature had a strong effect on CR fluctuation, whereas in oysters an effect of changes in salinity on CR variation was also found only in oysters. The interaction between temperature and salinity was statistically significant and suggested that their simultaneous effects on CR were significantly greater than when each of these factors acted independently. The highest E. coli concentrations in mussels and oysters exceeded the concentrations in seawater by an order of magnitude at least, while the CR in mussels exceeded the CR in oysters by 7.7- to 38.5-fold.U ovom radu istraživan je zajednički utjecaj temperature i saliniteta morske vode na akumuliranje bakterije Escherichia coli u dagnji (Mytilus galloprovincialis) i kamenici (Ostrea edulis) u eksperimentalnim uvjetima pri različitim koncentracijama E. coli u morskoj vodi. Eksperimenti su provođeni u bazenima volumena 3000 L, u prirodnim rasponima temperatura (12oC, 18oC i 24oC) i saliniteta (32 psu i 37 psu), karakterističnim za priobalje Jadranskog mora. U istraživanom rasponu koncentracija E. coli u morskoj vodi (4x10-4.6x103 EC/100 ml), zabilježena je brza akumulacija bakterija u školjkašima, a najviše koncentracije (prag) dosezane su u prvom satu kod dagnje i drugom satu kod kamenice. pri jednakim koncentracijama E. coli u morskoj vodi više maksimalne koncentracije E. coli zabilježene su kod dagnje. Utvrđena je jasna pozitivna povezanost između koncentracije E. coli u ambijentalnoj vodi i njene koncentracije u školjkašima (CR;concentration ratio-omjer koncentracija). Utvrđeno je također da je CR kontroliran temperaturom i salinitetom morske vode. Kod dagnje su promjene temperature značajno utjecale na promjene CR, dok su kod kamenice, osim temperature, na promjene CR značajno utjecale i promjene saliniteta. I kod dagnje i kod kamenice, zajednički učinak temperature i saliniteta bio je značajniji od njihovog pojedinačnog učinka. Najviše koncentracije E. coli u školjkašima za najmanje jedan red veličine su premašivale koncentracije u moru, dok je omjer najviših koncentracija u dagnjama i kamenicama bio u rasponu 7.7- 38.5

Brojnost i sastav pikoplanktonske zajednice u srednjem Jadranu

The abundance and structure of the picoplankton community were studied at two stations, one in coastal waters and one in offshore waters, of the middle Adriatic from December 1996 to June 1998. The abundance of prokaryotic Synechococcus cells, eukaryotic autotrophic picoplankton, and heterotrophic nanoflagellates (HNF) was determined, as were the chlorophyll a, physical and chemical factors, and nutrients of the water. Synechococcus dominated the picoplankton abundance by 96%. In offshore waters, the abundance of Synechococcus was influenced by nutrient availability and HNF abundance more than by temperature. In coastal waters, where nutrients were not a limiting factor, temperature had greater influence. Picophytoplankton contributed more to the total phytoplankton biomass in offshore (31%) than in coastal (9%) waters.Brojnost i struktura pikoplanktonske zajednice istraživana je na dvjema postajama smještenim u obalnim i otvorenim vodama srednjeg Jadranau u razdoblju od prosinca 1996 do lipnja 1998. Istraživanjem je obuhvaćena brojnost cijanobakterija Synechococcus, eukariotskog pikoplanktona i heterotrofnih nanoflagelata (HNF), koncentracija klorofila a kao i fizikalno kemijski parametri (slanost, temperatura, hranjive soli). Rezultati istraživanja pokazali su da u pikofitoplankltonskoj zajednici dominiraju cijanobakterije Synechococcus (96%). Brojnost cijanobakterija u otvorenim vodama najvećim je dijelom uvjetovana raspoloživom koncentracijom hranjivih soli kao i veličinom populacije HNF. Temperatura ima veći utjecaj na brojnost cijanobakterija u obalnim vodama gdje hranjive soli nisu ograničavajući factor. Pikofitoplankton znatno više dobrinosi ukupnoj fitoplanktonskoj biomasi u otvorenim vodama (31%) nego u obalnim vodama (9%)

Struktura mikrobne zajednice u anhialinim špiljama na otoku Mljetu (Jadransko more)

The microbial abundances, including bacteria, viruses, and heterotrophic nanoflagellates, were determined for two anchialine caves located on the Island of Mljet (Adriatic Sea): Bjejajka Cave and Lenga Pit. Both caves are situated approximately 100 m from the coast with extensive subterranean connections to the sea, resulting in noticeable marine and terrestrial, influences. Because of the shallow settings of the studied caves, they represent habitats with a minimal light or complete darkness where photosynthesis is minimal or not possible. Thus, during the surveys there was no evidence of cyanobacterial cells in either caves, but the presence of bacteria, viruses and heterotrophic nanoflagellates (HNF) was established. Further, bacterial abundance was higher in caves in comparison to surrounding open seawater. In the surrounding seawater the predominance of the LNA group over HNA is determined, which also indicates the differences in relation to the studied caves. In fact, the dominance of HNA group of bacteria in caves together with higher total bacterial abundance indicates that the caves are of higher trophic level than the surrounding seawater. With regard to bacterial diversity, both caves had a unique makeup of bacterial populations and low diversity, with the chemolithoautotrophic Epsilonproteobacteria representing the most abundant taxonomic group. To examine the mechanisms regulating bacterial abundance in these habitats, we observed the relationship between bacteria and heterotrophic nanoflagellates (HNF) and between bacteria and viruses. The importance of predation in controlling bacteria (top down control) and, consequently, the domination of bottom up control of HNF were observed in both caves.Istraživanja abundancije mikroorganizama, uključujući bakterije, viruse i heterotrofne nanoflagelate (HNF) su provedena u anhialinim špiljama Bjejajka i Lenga na otoku Mljetu. Špilje su smještene na oko 100 m udaljenosti od obalne linije s podzemnom vezom s morem te su pod znatnim utjecajem mora kao i kopnenih staništa. S obzirom na položaj istraživane špilje predstavljaju staništa s minimalnim prodorom svjetlosti ili potpunim mrakom što ukazuje na izostanak procesa fotosinteze. Tijekom istraživanja ni u jednoj špilji nije utvrđeno prisustvo cijanobakterija odgovornih za procese fotosinteze, ali je utvrđena značajna brojnost bakterija, virusa i heterotrofnih nanoflagelata. Štoviše brojnost bakterija u špiljama je bila veća od brojnosti bakterija u okolnom moru. Jednako i odnosi HNA i LNA bakterija ukazuju na razlike između špilja i okolnog mora. U okolnom moru je utvrđena dominacija LNA bakterija u odnosu na HNA dok je u špiljama utvrđeno prevladavanje HNA bakterija što zajedno s većom ukupnom brojnošću bakterija ukazuje na viši trofički stupanj u špiljama u odnosu na okolno more. Preliminarnim ispitivanjem raznolikosti bakterija u špiljama je utvrđeno najbrojnije prisustvo kemolitoautotrofnih bakterija taksonomske skupine Epsilonproteobacteria. U svrhu studiranja mehanizama regulacije bakterijske abundancije u istraživanim su špiljama analizirani odnosi između bakterija i heterotrofnih nanoflagelata i između bakterija i virusa. Važnost predacije u kontroli bakterija (top down kontrola) je utvđena u obje ispitivane špilje

Dinamika prokariotske zajednice u Bokokotorskom zaljevu (Južni Jadran)

The dynamics of the prokaryotic picoplankton community were studied at six stations of three embayments in Boka Kotorska Bay from January 2010 to January 2011. The abundance of non-pigmented bacteria, high nucleic acid content (HNA) bacteria, low nucleic acid content (LNA) bacteria, bacterial production and heterotrophic nanoflagellates was determined, as well as the chlorophyll a, physical and chemical factors of the water column. It seems that freshwater input has the ability to control bacterial abundance as well as the proportion of HNA cells in bacterial community and thus the abundance of HNF cells. During the warmer seasons, in the investigated area, which is mainly oligotrophic, we found an increase in values and domination of the LNA group in the bacterial population. The dominance of the HNA group was found only during the colder seasons. Weak coupling between bacteria and HNF suggests that predation (top down control) is not dominant in controling of bacterial abundance in studied area.Raspodjela i aktivnost prokariotskog pikoplanktona u crnogorskom dijelu južnog Jadrana je studirana na šest postaja Bokokotorskog zaljeva u razdoblju od siječnja 2010. do siječnja 2011. Istraživana je brojnost nepigmentiranih bakterija, udjeli bakterija s visokim (HNA) i niskim (LNA) sadržajem nukleinskih kiselina, bakterijska proizvodnja, heterotrofni nanoflagelati (HNF) te klorofil a i fizikalno kemijski čimbenici. Utvrđeno je da unos slatke vode u istraživano područje ima utjecaja na bakterijsku brojnost, na udjele HNA I LNA grupa bakterija kao i na brojnost HNF-a. U toplijem razdoblju godine u istraživanom je području utvrđen porast i prevladavanje LNA bakterija dok je prevladavanje HNA bakterija utvrđeno u hladnijem dijelu godine. Slaba povezanost između bakterija i HNF ukazuje da predacija nije prevladavajući mehanizam kontrole bakterijske abundancije u istraživanom području

The Proposal of the Croatian Society for Rheumatology for the treatment of adult rheumatoid arthritis patients with biologics, 2013

Standardiziran pristup bolesnicima s reumatoidnim artritisom (RA) jedan je od uvjeta dobre reumatološke kliničke prakse. Hrvatsko reumatološko društvo (HRD) Hrvatskog liječničkog zbora (HLZ) ažuriralo je Prijedlog liječenja RA biološkim lijekovima u skladu s novijim spoznajama u reumatologiji kroz posljednje 3 godine. Poštivanjem dogovorenog standarda liječenja izbjegava se nesavjesno liječenje i neracionalna potrošnja, a većini bolesnika pruža veća šansa za povoljan ishod.Standardized approach to the patients with rheumatoid arthritis (RA) is one of the requirements of good clinical practice. Croatian Society for Rheumatology (HRD) of Croatian Medical Association (HLZ) updated the Proposed treatment of rheumatoid arthritis (RA) with biologic agents in line with recent findings in rheumatology for the last 3 years. By complying with the agreed standards of treatment we can avoid malpractice and irrational consumption, and to the most patients provide a greater chance for a favorable outcome

The Proposal of Croatian Society for Rheumatology for anti-TNF-α therapy in adult patients with spondyloarthritides, 2013.

Hrvatsko reumatološko društvo Hrvatskog liječničkog zbora ažuriralo je Prijedlog primjene inhibitora TNF-α u odraslih bolesnika sa spondiloartritisima (SpA) u skladu s novom klasifikacijom SpA i europskim preporukama za liječenje biološkom terapijom. Na ovaj način postiže se standardiziran način dijagnostike, ciljanog liječenja, praćenja i ocjene ishoda primljenjiv za većinu bolesnika.Croatian Society for Rheumatology of Croatian Medical Association updated the proposal for the application of TNF-α inhibitors in adult patients with spondyloartritides (SpA) in accordance with the new classification of SpA and european recommendations for the treatment of SpA with biologic agents. In this way a standardized method of diagnosis, targeted treatment, monitoring and evaluating outcomes are proposed

HNA i LNA bakterije u odnosu na aktivnost heterotrofnih bakterija

A one-year survey of HNA and LNA heterotrophic bacteria abundance and its relation to bacterial production was conducted in the middle and southern Adriatic. The average abundance of heterotrophic bacteria in the central and southern coastal areas of the eastern coast of the Adriatic Sea ranged from 0.24×106 to 2.39×106 cells mL-1 and in the open sea area ranged from 0.23×106 to 0.63×106 cells mL-1. Elevated average abundances were found in the coastal area of Šibenik and in Kaštela Bay. The average monthly percentage of HNA bacteria in the central and southern coastal areas investigated ranged from 21.48 to 93.18%, while in the open sea HNA ranged from 28.62 to 65.62%. The seasonal distribution in the coastal areas mostly showed simultaneously the prevalence of LNA bacteria in the bacterial community and high values of bacterial production, respectively, during spring and summer. The prevalence of the HNA group in the bacterial community was found during colder seasons together with low values of bacterial production. Exceptions are identified in the areas influenced by rivers with the highest bacterial production, where HNA bacteria were dominant in the microbial community during all four seasons. On the open sea during the periods with the highest values of bacterial production, when viewed seasonally and vertically, the water column was dominated by LNA bacteria indicating the importance of both groups of bacteria in the marine ecosystems of the waters studied.Jednogodišnje istraživanje HNA i LNA heterotrofnih bakterija u odnosu na bakterijsku proizvodnju provedeno je na području srednjeg i južnog Jadrana. Prosječna bakterijska brojnost na istraživanom obalnom području srednjeg i južnog Jadrana iznosila je od 0.24 × 106 do 2.39 x 106 st mm-1, te na otvorenom moru od 0.23 × 106 to 0.63 × 106 st ml-1. Najviše vrijednosti utvrđene su na obalnom području Šibenika i Kaštelanskom zaljevu. Prosječna bakterijska brojnost na području otvorenog mora iznosila je od 0.23 × 106 do 0.63 × 106 st ml-1. Prosječni udio HNA bakterija na istraživanom priobalnom području iznosio je u rasponu od 21.48 do 93.18%, dok je na otvorenom moru HNA iznosio od 28.62 do 65.62%. Sezonska je raspodjela tijekom proljeća i ljeta na obalnom području uglavnom pokazala istovremeno prevladavanje LNA grupe u bakterijskoj zajednici i visoke vrijednosti bakterijske proizvodnje. Prevladavanje HNA grupe u bakterijskoj zajednici utvrđeno je tijekom hladnijeg razdoblja, zajedno s niskim vrijednostima bakterijske proizvodnje. Iznimke su utvrđene na područjima najviše bakterijske aktivnosti (područja pod utjecajem rijeka), gdje su HNA bakterije prevladavale u vodenom stupcu tijekom sve četiri sezone. Na području otvorenog mora sezonska i vertikalna raspodjela je za vrijeme visokih vrijednosti bakterijske proizvodnje pokazala prevladavanje LNA bakterija. Navedeno upućuje na važnost obiju bakterijskih grupa u morskom ekosustavu istraživanog područja