First Report of Marek's Disease Virus in Commercial Turkeys in Slovenia.

Marek's disease (MD), caused by Mardivirus gallidalpha 2 (GaAHV-2), also known as MD virus (MDV), is a lymphoproliferative disease that primarily affects chickens. Recently, MDV has been detected in lymphomatous tumors in turkeys in various countries. Between 2021 and 2023, three cases ranging from no to severe clinical disorders (depression, lameness, and increased mortality) occurred in commercial turkey flocks in Slovenia. In all cases, MDV was detected by PCR in DNA samples extracted from organs developing tumor infiltrations. Sequencing and phylogenetic analysis of the meq gene revealed that the GaAHV-2 detected has molecular features of a very virulent pathotype and genetic similarity with GaAHV-2 detected in chickens in Tunisia. This is the first report of MDV in commercial turkeys in Slovenia.

Novel adenoviruses from captive psittacine birds in Slovenia.

To assess the prevalence of adenoviruses in psittacine birds kept in Slovenia, 258 cloacal swabs were collected from different psittacine species and screened by a nested PCR with degenerate, consensus primers targeting the adenoviral DNA polymerase gene. Forty-two samples were found to be positive. By sequencing, 28 samples from 10 different parrot species were identified as the formerly described siadenovirus, psittacine adenovirus 2 (PsAdV-2). A second siadenovirus, a variant of PsAdV-5 (described earlier from Pacific parrotlet, sun parakeet, cockatiel and budgerigar) was found in seven budgerigars, two cockatiels and an amazon parrot species. A variant of Meyer's parrot adenovirus (aviadenovirus, proposed PsAdV-8) was identified in an African grey parrot and a cockatiel. Two novel atadenoviruses were revealed in cockatiel (PsAdV-9) and rose-ringed parakeet (PsAdV-10). These results support the earlier finding that many PsAdVs can cross the species barrier among psittacines, especially effectively in the case of PsAdV-2.

Occurrence of Bacterial and Viral Pathogens in Common and Noninvasive Diagnostic Sampling from Parrots and Racing Pigeons in Slovenia.

Airborne pathogens can cause infections within parrot (Psittaciformes) and pigeon (Columbiformes) holdings and, in the case of zoonoses, can even spread to humans. Air sampling is a useful, noninvasive method which can enhance the common sampling methods for detection of microorganisms in bird flocks. In this study, fecal and air samples were taken from four parrot holdings. Additionally, cloacal and oropharyngeal swabs as well as air samples were taken from 15 racing pigeon holdings. Parrots were examined for psittacine beak and feather disease virus (PBFDV), proventricular dilatation disease virus (PDDV), adenoviruses (AdVs), avian paramyxovirus type-1 (APMV-1), avian influenza virus (AIV), Chlamydia psittaci (CP), and Mycobacterium avium complex (MAC). MAC and AdVs were detected in three parrot holdings, CP was detected in two parrot holdings, and PBFDV and PDDV were each detected in one parrot holding. Pigeons were examined for the pigeon circovirus (PiCV), AdVs, and CP; PiCV and AdVs were detected in all investigated pigeon holdings and CP was detected in five pigeon holdings.

Uterine heterologous malignant mixed Müllerian tumor in a dwarf rabbit (Oryctolagus cuniculus).

Malignant mixed Müllerian tumor (MMMT) is a rare neoplasm of the female genital system. A case of MMMT in the uterus of an 8-year-old female dwarf rabbit, which died with clinical signs associated with severe acute dyspnea and anorexia, is described. At necropsy, an oval, firm tumor was found in each of the 2 uterine horns. Numerous metastases were scattered throughout the mediastinum, thoracic diaphragm, and all pulmonary lobes. Microscopically, the tumors consisted of a poorly demarcated, unencapsulated neoplasm, composed of closely associated carcinomatous and sarcomatous components and areas of osteosarcomatous differentiation. Metastases were composed entirely of the sarcomatous component with osteosarcomatous differentiation. Immunohistochemically, the neoplastic epithelial component was positive for cytokeratin and negative for α-smooth muscle actin (α-SMA), vimentin, and desmin. The sarcomatous component was diffusely and strongly positive for vimentin, focally positive for α-SMA (<20% of cells positive), and negative for desmin. The neoplasm was diagnosed as a heterologous MMMT with metastases to the lung, mediastinum, and thoracic diaphragm.

Variation of vlhA gene in Mycoplasma synoviae clones isolated from chickens.

Mycoplasma synoviae synthesizes haemagglutinin VlhA, which cleaves into the N-terminal part, a lipoprotein MSPB, and a C-terminal part MSPA. Previous studies have shown that the 3'-end of the expressed vlhA gene can recombine with vlhA pseudogenes in a process called gene conversion, but there have been no data about diversification of the expressed vlhA gene in M. synoviae populations replicating in chickens. Following intratracheal inoculation with the M. synoviae strain ULB 02/T6, which showed only minor vlhA gene variation prior to inoculation, we investigated temporal changes in MSPB epitopes defined by monoclonal antibodies (mAbs) 3B4 and 50, as well as diversification of the vlhA gene sequence in M. synoviae populations recovered from chicken tracheas. In cultures isolated 8 and 18 days post inoculation (p.i.), most colonies showed variation of MSPB epitopes for mAbs 3B4 and 50. They also changed 3'-end vlhA gene sequences. Further diversity of the vlhA gene occurred in cultures isolated 8 weeks and 5 months p.i. The vlhA gene sequences from isolated cultures shared only 65 to 80% sequence identity with vlhA gene of the inoculated ULB 02/T6 culture. Notably, in most of those cultures their vlhA gene sequences contained stop codons potentially causing premature terminations of translation. Interestingly, in one culture isolated 8 weeks p.i. (clone T6-8W/IT2A) the 3'-vlhA gene sequence was identical in the last 1140 bases to that of the first vlhA pseudogene positioned the most far (upstream) of the expressed vlhA gene. This is the first demonstration of temporal diversity of the vlhA gene in M. synoviae populations isolated from chicken tracheas.