Serological survey of Chlamydia abortus in Greek dairy sheep flocks

Chlamydiosis due to Chlamydia abortus is one of the most common causes of abortion in small ruminant flocks worldwide. Although the causative agent is zoonotic, chlamydiosis is not a reportable disease. There is lack of recent data concerning sheep chlamydiosis in Greece.In the current study, a serological investigation for Chlamydia abortus was conducted. Blood samples from 26 randomly selected sheep flocks not vaccinated against chlamydiosis were collected. From each flock, 15 to 20 blood samples were taken from adult female sheep. In total 464 blood samples were examined. One hundred and six samples were positive (22.8%), while 24 samples (5.24%) were doubtful.  Moreover, at farm level, in 18 out of the total number of 26 farms, at least one positive animal was detected (69.2%).Chlamydiosis is considered a highly likely cause of sheep abortion in Greece. Therefore, vaccination of the sheep flocks is strongly recommended for the prevention and control of the disease. 

Seroprevalence and risk factors assessment of Brucella spp. in dairy buffaloes in mainland Greece

Brucellosis is an infectious bacterial disease caused by members of genus Brucella, affecting both animals and humans, and resulting in both serious economic losses in animal production sector and deterioration of public health. A cross-sectional study was conducted from January to August of 2018 to determine the seroprevalence and associated risk factors of bovine brucellosis, in Central Macedonia and East Macedonia and Thrace, in mainland Greece. A total of 1,255 blood samples were collected using a simple random sampling technique from dairy buffaloes older than12 months. All serum samples were analyzed with Rose Bengal Test for screening and Complement Fixation Test for confirmation of the positive samples. Accordingly, the overall individual-level seroprevalence of dairy buffaloes in the study area was 0.72% (9/1,255, 95% CI:0.32-1.36%) while the overall herd-level seroprevalence was 15.38% (4/26, 95% CI:6.15-33.53%). Moreover, information was gathered on demographic characteristics of the owners, individual animals and herd level risk factors and other farm characteristics using a questionnaire. Higher prevalence of Brucella spp. was observed in buffaloes bred under intensive and semi-intensive feeding systems, compared to those bred under extensive ones. High seroprevalence of brucellosis was also observed in medium size herds. Two of the herds had recorded history of the disease, the last five years while, in these two herds delays in the implementation of brucellosis eradication programs were revealed. The present study indicated that the occurrence of brucellosis in Greece dairy buffalo farms is at a low magnitude. Even though the seroprevalence is low, it can still be potential hazard for both susceptible animals and humans

First Detection and Identification of FAdV-8b as the Causative Agent of an Outbreak of Inclusion Body Hepatitis in a Commercial Broiler Farm in Greece

Inclusion body hepatitis (IBH) is an economically important disease of chickens, with a worldwide distribution, caused by Fowl Aviadenoviruses (FAdVs). Currently, the increased number of cases, the virulence of the isolate strains, as well as the lack of cross-species protection highlight that detailed in-field data are fundamental for the development of successful control strategies. This case report provides a detailed clinicopathological investigation of an unusual IBH outbreak in a commercial broiler farm in the region of Macedonia, Greece. The farm consisted of 64,000 birds, originated from the same breeder stock and placed in three different houses (Flock A–C). At 20 days of age, a sudden increase in daily mortality was recorded in Flock A. It is worth mentioning that, although all flocks were serologically (indirect ELISA) and molecularly (RT-PCR) positive for FAdV, the mortality rate, attributed to IBH, was much higher in Flock A compared to others. The clinical manifestation included non-specific symptoms such as depression, inappetence, yellowish mucoid diarrhea, and lack of uniformity. At necropsy, typically, enlarged, pale, and friable livers were dominant, while sporadically lesions were recorded in the pancreas, kidneys, skeletal muscles, and lymphoid organs. The histopathological examination of liver samples showed multifocal inflammation, necrosis, and the presence of basophilic/ eosinophilic inclusion bodies in hepatocytes. In addition, the loss of the architecture of pancreatic lobules and the presence of fibrosis and foci of mononuclear cell aggregates were suggestive of chronic pancreatic inflammation. PCR analysis confirmed the presence of FAdV, belonging to species E, serotype FAdV-8b. Performance and financial calculations revealed that IBH increased Feed Conversion Ratio (FCR), feed cost/chick as well as feed cost/kg live weight, whereas the Livability (%) and the European Production Efficiency Factor (EPEF) were decreased in the most severely affected flocks (Flock A). This study is the first report of the detection and identification of FAdV serotypes associated with IBH in commercial broiler flocks in Greece. However, there is still a lack of information about the circulating FAdV serotypes in the country, and therefore epidemiological studies are needed to establish control strategies for IBH.

First report of detection of microcystins in farmed mediterranean mussels Mytilus galloprovincialis in Thermaikos gulf in Greece

BACKGROUND

Microcystins are emerging marine biotoxins, produced by potentially toxic cyanobacteria. Their presence has been reported in aquatic animals in Greek freshwater, while data are few in marine environments. Since the climate change induces eutrophication and harmful algal blooms in coastal marine ecosystems affecting the public health, further research on microcystins' presence in marine waters is required. The aim of this study was to examine the potential presence of microcystins in mussels Mytilus galloprovincialis in the largest farming areas in Thermaikos gulf, in Northern Greece, and to investigate their temporal and spatial distribution, adding to the knowledge of microcystins presence in Greek Mediterranean mussels.

RESULTS

A 4-year microcystins' assessment was conducted from 2013 to 2016, in farmed Mediterranean mussels M. galloprovincialis, in five sampling areas in Thermaikos gulf, in northern Greece, where the 90% of the Greek mussels' farming activities is located. The isolation of potentially toxic cyanobacteria was confirmed by molecular methods. An initial screening was performed with a qualitative and quantitative direct monoclonal (DM) ELISA and results above 1 ng g-1 were confirmed for the occurrence of the most common microcystins-RR, -LR and -YR, by Ultra High Performance Liquid Chromatography (UHPLC) coupled with a high- resolution mass spectrometer (HRMS) (Orbitrap analyzer). Microcystin-RR and microcystin-LR were detected, while the intensity of microcystin-YR was below the method detection limit. Most samples that exhibited concentrations above 1 ng g-1 were detected during the warm seasons of the year and especially in spring. Results indicated an overestimation of the ELISA method, since concentrations ranged between 0.70 ± 0.15 ng g-1 and 53.90 ± 3.18 ng g-1, while the confirmation denoted that the levels of microcystins were 6 to 22 times lower.

CONCLUSIONS

Microcystin-RR and microcystin-LR were detected for the first time in mussel M. galloprovincialis, harvested from farms in Thermaikos gulf, in Central Macedonia, Greece. Their presence was linked to potentially toxic cyanobacteria. Bioaccumulation was observed in digestive gland, while the concentrations in muscles were found extremely low. Samples with levels above 1 ng g-1 were observed mostly during spring, confirming the seasonal distribution of microcystins. The comparison of the results by the ELISA and the LC-Orbitrap MS method indicated an overestimation of concentration by the ELISA method.

Reduction of the abortion rate due to Toxoplasma in 3 goat herds following administration of sulfadimidine

The efficacy of sulfadimidine (4 doses of 33 mg/kg body weight, IM, q48h) against Toxoplasma abortion was assessed in 3 dairy goat herds suffering from Toxoplasma abortions during the 4th month of gestation. This protocol was very effective for the control of Toxoplasma abortions (P < 0.01).

Acute coenurosis of dairy sheep from 11 flocks in Greece

CASE HISTORY

A syndrome of acute neurological dysfunction with increased mortality was observed in lambs of 10 dairy sheep flocks and adult animals in one flock in Central and Northern Greece. Each farmer completed a questionnaire regarding the management and feeding of their flocks. In seven of the 11 flocks the affected animals were grazing pasture, while in the remaining four flocks (5, 8, 9, 10) the animals were fed alfalfa hay (Medicago sativa) and concentrates indoors. A follow-up study of the affected flocks was conducted during the next 12 months.

CLINICAL FINDINGS

Of 42 sheep with acute coenurosis that were examined, the most prominent neurological abnormalities were ataxia, depression, blindness, scoliosis, coma and dysmetria. Except for the four sheep that were comatose, all other animals had normal body temperatures and their appetites remained normal or were slightly decreased. Haematological findings of 15 examined sheep were within normal limits. The affected sheep were subject to euthanasia. A histopathological examination was performed in 13 cases. Faecal samples from dogs associated with these flocks were negative for taeniid infections. During the following 12 months cases of chronic coenurosis in these flocks were observed.

PATHOLOGICAL FINDINGS

In the 42 animals that were necropsied, the main gross findings were cystic formations between 0.5-1 cm in diameter with translucent walls that were seen lying free on the leptomeninges or partly penetrating the brain tissue, sterile microabscecess and brain necrosis. Histopathological evaluation of tissue sections of 13 brains showed multifocal purulent or pyogranulomatous meningoencephalitis, accompanied by eosinophilic infiltrations. No bacteria were isolated following bacterial culture of brain tissue Parasitological examination of the cysts from five cases revealed whitish specks on the transparent cyst wall and germination membrane representing the scolices.

DIAGNOSIS

Acute coenurosis was diagnosed in all cases studied.

CLINICAL RELEVANCE

Acute coenurosis can be one of the causes of acute encephalopathy mainly in lambs, but also in adult sheep. This condition is incurable, but can be controlled by changing the feeding regime. Cases of chronic coenurosis may be seen a few months later in the same flock.