Pathogenic and Opportunistic Vibrio spp. Associated with Vibriosis Incidences in the Greek Aquaculture: The Role of Vibrio harveyi as the Principal Cause of Vibriosis

A monitoring program to follow vibriosis incidents in the Greek marine aquaculture was implemented over the past 13 years. 273 isolates, from various cases originating from eight regions and nine hosts, were collected and characterized. The main aquaculture species of the survey were the European seabass (Dicentrarchus labrax) and the gilthead seabream (Sparus aurata). Various species of Vibrionaceae were associated with vibriosis. Vibrio harveyi had the highest prevalence and was isolated throughout the year from all hosts. During the warm months, Vibrio harveyi prevailed with frequent co-isolations of Photobacterium damselae subsp. damselae and Vibrio alginolyticus, while during spring, other Vibrio species were more abundant, such as Vibrio lentus, Vibrio cyclitrophicus, and Vibrio gigantis. Phylogenetic analysis using the mreB gene and the metabolic fingerprint of the isolates showed great variability within the species of the collection. The severity of the disease and the frequency of outbreaks make vibriosis (that is, mainly attributed to V. harveyi) an important concern for the regional aquaculture sector.

Development of autogenous vaccines for farmed European seabass against Aeromonas veronii using zebrafish as a model for efficacy assessment

Aeromonas veronii bv. sobria is an emerging pathogen for the European seabass cultured in the Aegean Sea (Mediterranean) causing significant problems in the Greek and Turkish aquaculture industry since no licensed vaccine is currently available for the disease. A bivalent vaccine was developed based on two phenotypically distinct strains of the pathogen, PDB (motile, pigment-producing strain) and NS (non-motile, non-pigment-producing). The two strains comprising the bivalent vaccine were evaluated as monovalent products in zebrafish before the seabass trials. Challenges using the homologous or the heterologous strain showed that both vaccines were protective with RPS values ranging between 66 and 100% in zebrafish. The bivalent vaccine was then tested in European seabass following dip or intraperitoneal administration. Efficacy was evaluated separately against both strains comprising the bivalent vaccine. Dip vaccination applied to juvenile seabass of 2.5 g average weight provided protection following challenge tests 30 days post vaccination only in one of the two strains tested (strain PDB, RPS: 88%). This was also the case in the injection vaccination of adult seabass of 60 g average weight where the vaccine was effective only against the PDB strain (RPS: 63%). High antibody titers against both strains were found at 30 and 60 days after intraperitoneal vaccination in the adult seabass. The use of zebrafish as a model for vaccine development for aquaculture species is discussed.

Prevalence and factors associated with hyperkalaemia in stable kidney transplant recipients

Background

Hyperkalaemia is a frequent and potentially life-threatening condition in patients with chronic kidney disease (CKD). Even after successful kidney transplantation (KTx), KTx recipients have mild to severe CKD. Moreover, they share comorbid conditions and frequently use medications that predispose to hyperkalaemia. This study aimed to examine the prevalence and factors associated with hyperkalaemia in this population.

Methods

Over a pre-specified period of 6 months (1 September 2019 to 31 March 2020), we recorded in cross-sectional fashion information on serum potassium (K⁺) and relevant demographics, comorbidities, medications, laboratory and transplant-associated variables in clinically stable KTx recipients attending the Transplant Outpatient Clinic of our Department. Ηyperkalaemia was classified as follows: serum K⁺ level >5.0 mEq/L; and further as >5.0 mEq/L with concomitant use of sodium (Na⁺) polystyrene sulphonate; serum K⁺ ≥5.2 mEq/L; serum K⁺ ≥5.5 mEq/L. Univariate and multiple logistic regression analyses were used to identify factors associated with serum K⁺ >5.0 mEq/L.

Results

The study population consisted of 582 stable KTx recipients, 369 (63.4%) males, aged 52.4 ± 13.5 years, with estimated glomerular filtration rate (eGFR) of 55.8 ± 20.1 mL/min/1.73 m² transplanted for >1 year. The prevalence of hyperkalaemia defined as K⁺ >5.0 mEq/L; >5.0 mEq/L and use of Na⁺ polystyrene sulphonate; K⁺ ≥5.2; or K⁺ ≥5.5 mEq/L, was: 22.7, 22.7, 14.4 and 4.1% (132, 132, 84 and 24 patients), respectively. In multivariate analysis, male gender [odds ratio (OR) = 2.020, 95% confidence interval (CI) 1.264–3.227] and use of renin–angiotensin–aldosterone system (RAAS) blockers (OR = 1.628, 95% CI 1.045–2.536) were independently associated with hyperkalaemia, while higher eGFR (OR = 0.967, 95% CI 0.955–0.979) and use of non-K⁺-sparing diuretics (OR = 0.140, 95% CI 0.046–0.430) were associated with lower odds of the disorder.

Conclusions

The prevalence of mild hyperkalaemia in stable KTx recipients is relatively high but that of moderate or severe hyperkalaemia is low. Among a wide range of factors studied, only male gender and RAAS blockade were associated with increased odds of hyperkalaemia, while higher eGFR and diuretics were associated with decreased odds of hyperkalaemia.

Risk Factors of the Development of Diabetes Mellitus After Kidney Transplantation

BACKGROUND

The occurrence of diabetes mellitus is common after kidney transplantation (posttransplant diabetes mellitus [PTDM]) and enhances the cardiovascular risk and risk for kidney graft loss. The incidence of PTDM is about 5% to 40%. This study aimed to examine the potential risk factors that determine the occurrence of PTDM.

METHODS

This study retrospectively included 298 patients from transplantation unit of Evangelismos who underwent kidney transplantation during a 10-year period (January 1, 2009, to January 1, 2019). Kidney transplant recipients with diabetes mellitus prior to transplantation or those with follow-up of <6 months were rejected from the study. In total, the study included 274 recipients with a mean age of 50 ± 18 years. The mean time of monitoring was 63 ± 18 months. The PTDM diagnosis was based on the 2018 criteria of the American Diabetes Association.

RESULTS

Of 274 kidney transplant recipients, PTDM developed in 38 (13.8%) patients over a period of 11 ± 9 months after transplantation. Given that immunosuppressive therapy was identical in most patients, statistical analysis did not correlate the incidence of diabetes with treatment. However, there was a correlation for the occurrence of PTDM between the presence of hypomagnesemia and increased uric acid levels. Finally, there was a negative correlation between the age of the recipient and the time of PTDM onset.

CONCLUSION

Hypomagnesemia and hyperuricemia increased the risk of PTDM in these patients. Given the association between hypomagnesemia and the development of diabetes mellitus after kidney transplantation, prospective studies are needed to identify the causes of PTDM and to develop prevention strategies.

Determinants of Parathyroid Hormone Levels During the First Year After Kidney Transplantation

BACKGROUND

Spontaneous remission of secondary hyperparathyroidism after kidney transplantation requires time to occur. The aim of the present study was to investigate factors that may be related to the reduction of parathyroid hormone (PTH) after transplantation as well as the rate of its reduction.

METHODS

We studied 81 kidney transplant recipients at our transplantation center between January 2014 and September 2017. The relationship of PTH values during the first year after transplant with renal function, type of kidney graft origin (deceased or living), and delayed renal graft function was examined. Moreover, we determined the correlation of the rate of PTH reduction within the first year with the value of PTH before transplant.

RESULTS

Of the total of 81 recipients, 28 (35.1%) were women and 53 (64.8%) were men, with a mean age of 47 ± 11.87 years. At the same time, there was a decrease of PTH by 33% in the first half of the first year after transplantation and by 57% in the second. In addition, a statistically significant correlation of PTH with renal function was found (P = .001), with PTH values decreasing as the glomerular filtration rate increased. Finally, transplants from deceased donors were associated with higher values of PTH, whereas the value of PTH before transplant was positively correlated with the value after it (P = .001).

CONCLUSIONS

Secondary hyperparathyroidism, which accompanies end-stage chronic renal failure, usually resolves adequately after transplantation. The determinants of this resolution are the recipient's renal function, the kidney graft origin (deceased), and the pretransplant PTH values.

Resistive Renal Index of the Recipient and its Correlation With the Outcome of Kidney Transplantation at the End of the First Year: Preliminary Results

BACKGROUND

Renal resistive index (RRI) of ultrasonography is a useful and potent tool for the assessment of patients who have undergone transplantations. The aim of this study was to evaluate the association of RRI with renal function 1 year after transplant.

METHODS

We retrospectively evaluated 93 kidney allograft recipients. Data were collected from transplantations performed in our medical center between January 2014 and September 2018. Patients with acute loss of the renal function and renal survival <1 year were excluded from the study. We longitudinally compared the RRI at the first week after transplant and the third month, with estimated glomerular filtration rate (eGFR, by Chronic Kidney Disease Epidemiology Collaboration equation) at the end of the first year of transplantation. RRI was divided into 2 groups (RRI ≤0.80 or >0.80).

RESULTS

From the total of 86 recipients, 59 (68.6%) were male recipients and 27 female recipients with a mean age of 48.3 ± 12.1 years. No correlations were found between the first week's RRI with sex and age of both donors and recipients (P > .05). Similarly, the first week's RRI was not correlated with delayed graft function (DGF) and 1-year eGFR after transplant (P > .05). On the contrary, RRI performed at the third month was strongly correlated to DGF and eGFR at the end of the first year. Last but not least, neither higher recipient age nor sex affects the value of resistive index in the third month after transplantation (P < .05).

CONCLUSIONS

RRI values <0.80 in the third month after kidney transplantation were related to better annual renal function and a lower incidence of DGF.

Body Mass Index and Kidney Donor Profile Index as Prognostic Markers of the Outcome of Renal Transplantation

BACKGROUND

The aim of this study was to determine the effects of Kidney Donor Profile Index (KDPI) and body mass index (BMI) of the deceased donor on the kidney allograft outcome 1 year after transplantation.

METHODS

We retrospectively studied 98 deceased kidney allograft donors with a mean age of 56 ± 12 years. The donors were divided into 5 groups according to their BMI: Normal ΒΜΙ = 25 (n = 25); ΒΜΙ 25 to 29 = Overweight (n = 33); ΒΜΙ 30 to 34.9 = Obese class I (n = 19); ΒΜΙ 35 to 39 = Obese class ΙΙ (n = 11); and ΒΜΙ >40 = Obese class III (n = 10). We examined the impact of the deceased donor's BMI and KDPI on delayed graft function (DGF) and estimated renal glomerular filtration rate (eGFR) (measured by the Chronic Kidney Disease Epidemiology Collaboration equation) 1 year after transplantation.

RESULTS

Donor BMI significantly increased the prevalence of DGF (P = .031), and it was associated with higher cold ischemia time (P = .021). However, there was no significant association between the aforementioned BMI groups and 1-year eGFR (P = 0.57), as deceased grafts from donors with increased BMI (BMI > 40) gained sufficient renal function during the first year of transplantation. Moreover, high KDPI was associated not only with DGF (P = .015), but also with decreased values of eGFR (P = .033).

CONCLUSION

In this population, we identified no significant association between donor BMI and long-term clinical outcomes in deceased donor kidney transplants. KDPI, and not ΒΜΙ, of the deceased donor seems to be a good prognostic factor of renal function at the end of the first year after kidney transplant, whereas high BMI and high KDPI markedly induce DGF.

MO861THE PROGNOSIS OF PATIENTS RECEIVING CONTINUOUS RENAL REPLACEMENT THERAPY (CRRT) AFTER CARDIOVASCULAR SURGERY DEPENDS ON THE INDICATION FOR ITS INITIATION

Background and Aims

Continuous Renal Replacement Therapy is required in 2.6% to 5% of patients who have undergone cardiovascular surgery. Although its implementation is frequent, several aspects of this therapeutic measure still remain uncertain.

Method

The data of all patients who were surgically treated during a 3-year period (2017-2019) at a single cardiovascular department were collected and the cases in which continuous renal replacement therapy was used were identified. From this group, the data of those that received dialysis for the first time were analyzed.

Results

In about 5% of patients renal replacement was inevitable, and the mortality rate among them reached 57.6%. The mean duration of renal therapy was 8.4 days. The investigation of laboratory parameters in different stages revealed certain aspects about the expected outcomes. The survival rate varied significantly in relation to the indication for CRRT. Fluid overload and electrolytic disorders were associated with high survival rate, while oliguria or anuria, acidosis or intoxications were linked to increased mortality rate.

Conclusion

Despite CRRT being associated with high mortality rates, it is the only option for life-threatening conditions in clinical practice. The indication for CRRT is a key factor for the prognosis, decision-making and the overall management of a patient.

MO953PREVALENCE AND FACTORS ASSOCIATED WITH HYPERKALAEMIA IN STABLE KIDNEY TRANSPLANT RECIPIENTS WITH PRESERVED RENAL FUNCTION

Background and Aims

Hyperkalaemia is a frequent and potentially life-threatening condition in patients with CKD. Even after successful kidney transplantation, kidney transplant recipients have mild to severe CKD. Moreover, they share co-morbid conditions and frequently use medications that predispose to hyperkalaemia. This study aimed to examine the prevalence and factors associated with hyperkalaemia in this population.

Method

Over a pre-specified period of 6 months (September 1st 2019 to March 31st 2020), we recorded in a cross-sectional fashion information on serum potassium and relevant demographics, co-morbidities, medications, laboratory and transplant-associated variables in clinically stable kidney transplant recipients attending the Transplant Outpatient Clinic of our Department. Ηyperkalaemia was classified as follows: serum potassium level &gt;5 mEq/L or &gt;5 with concomitant use of sodium polystyrene sulfonate; ≥5.2; and ≥5.5 mEq/L. Univariate and multiple logistic regression analyses were used to identify factors associated with increased serum potassium &gt;5.0 mEq/L.

Results

The study population consisted of 582 stable kidney transplant recipients, 369 (63.4%) males, aged 52.4±13.5 years, with eGFR of 55.8±20.1 ml/min/1.73m2 transplanted for more than one year. The prevalence of hyperkalaemia defined as potassium &gt;5, &gt;5 and use of sodium polystyrene sulfonate, ≥ 5.2 or ≥5.5, was 22.7%, 22.7%, 14.4% and 4.1% (132, 132, 84 and 24 patients), respectively. In multivariate analysis, male gender (OR 2.020, 95% CI 1.264-3.227) and use of renin-angiotensin-aldosterone-system blockers (OR 1.628, 95% CI 1.045-2.536), were independently associated with hyperkalaemia, while higher eGFR (OR 0.967, 95% CI 0.955-0.979) and diuretic use (OR 0.140, 95% CI 0.046-0.430) were associated with lower odds of the disorder.

Conclusion

The prevalence of mild hyperkalaemia in stable kidney transplant recipients is common but that of moderate or severe hyperkalemia is relatively uncommon. Male gender and low eGFR are the most potent factors associated with hyperkalaemia. Among a wide range of factors only male gender, RAAS blockade and low eGFR increased the odds of hyperkalemia.

P1711RENAL RESISTIVE INDEX (RRI) OF KIDNEY ALLOGRAFT. OMEN OF THE OUTCOME OF TRANSPLANTION?

Background and Aims

Renal resistive index (RRI) of ultrasonography is a useful and potent tool for assessment and evaluation of renal hyperfiltration status of the transplanted patients. The aim of this study was to evaluate the association of RRI with renal function one year after transplant.

Method

We evaluated retrospectively 98 kidney allograft recipients. Data were collected from transplantations performed in our medical center between 01/2014 and 09/2018. Patients with acute loss of the renal function and renal survival less than a year were excluded from the study. We compared longitudinally the RRI at the first week after transplant and the third month, with glomerular filtration rate (eGFR, by CKD-EPI) at the end of the first year of transplantation. RRI was measured on the interlobular artery level, in each of the aforementioned time periods, and results were classified into 2 groups, RRI &lt;0,8 or&gt;0,8. In addition, age, gender and delayed graft function (DGF) were also determined in all patients.

Results

Sixty seven (67) of the recipients were males and 31 females with a mean age of 48±12years. The corresponding demographics for the donors were 46 males and 52 females with a mean age of 53 ±14. No correlations were found between RRI of the first week with gender and age, of both donors and recipients (p&gt;0.05). Similarly, RRI of the first week was not correlated with DGF and one-year eGFR after transplant (p&gt;0.05). On the contrary, RRI performed at the third month was strongly correlated to DGF and eGFR at the end of the first year. In other words, allograft recipients with a resistive index less than 0.80, had a higher eGFR and reduced frequency of DGF (p=0.01 and 0.03 respectively). Last but not least, higher recipient age and not gender was the main determinant of an increase of resistive index in the third month after transplant (P=0.02).

Conclusion

RRI offers interesting and helpful data on kidney allograft function. RRI of the third month less than 0.8 was related to better renal function at the end of the first year after transplant mainly and a lower incidence of DGF.

Comparative Study on A Novel Pathogen of European Seabass. Diversity of Aeromonas veronii in the Aegean Sea

Aeromonas veronii is an emerging pathogen causing severe pathology and mortalities in European seabass aquaculture in the Aegean Sea, Mediterranean. More than 50 strains of the pathogen were characterized biochemically and genetically in order to study the epidemiology of the disease, as well as the phylogeny and virulence of the bacterium. Based on the phenotypic characteristics, the isolates form three groups consisting of: (a) the West Aegean Sea, non-motile, non-pigment-producing strains, (b) the West Aegean Sea, motile, and pigment-producing strains and (c) the East Aegean Sea motile strains that produce minute amounts of pigment. All strains were highly similar at the genomic level; however, the pattern of West/East geographic origin was reflected in biochemical properties, in general genomic level comparison and in the putative virulent factors studied. Type VI secretion system was not detected in the western strains. The outer membrane protein (OMP) profile which contains proteins that are putative antigenic factors, was very similar between strains from the different areas. Although most of the OMPs were detected in all strains with great sequence similarity, diversification according to geographic origin was evident in known antigenic factors such as the maltoporin LamB. A systematic comparative analysis of the strains is presented and discussed in view of the emergence of A. veronii as a significant pathogen for the Mediterranean aquaculture.

First report of Edwardsiellosis in cage-cultured sharpsnout sea bream, Diplodus puntazzo from the Mediterranean

Background

Edwardsiella tarda, is a serious bacterial pathogen affecting a broad range of aquaculture fish species. The bacterium has also been reported as a human pathogen, however recent studies have dissociated the fish pathogenic Edwardsiella from those isolated from humans by placing them in a new species, E. piscicida. Here we report the first case of Edwardsiellosis in cultured sharpsnout sea breams, Diplodus puntazzo in Greece.

Case presentation

The disease has affected cultured sharpsnout sea breams of a commercial fish farm in a single location in East Greece. Two populations of sharpsnout sea breams stocked in two consecutive years in floating cages presented signs of disease which included nodules and abscesses in spleen and kidney, morbidity and cumulative mortality reaching 5.3 %. Using microbiological, biochemical and molecular tools we have identified Edwardsiella sp. as the main aetiological factor of the disease. Following phylogenetic analysis the bacterial isolates are grouped with the newly described Edwardsiella piscicida species.

Conclusions

This is the first report of Edwardsiellosis in this species but most importantly in sea cage-cultured fish in the Mediterranean which may pose a serious threat for aquaculture fish species in this region.