Outbreak of Chlamydia psittaci Infection in a Commercial Psittacine Breeding Aviary in Argentina.

Chlamydiosis, caused by Chlamydia psittaci is a bacterial infection found in at least 465 species of birds worldwide. It is highly contagious among birds and can spread to humans. In birds, the disease can manifest itself in acute, subacute, and chronic forms with signs including anorexia, diarrhea, lethargy, weight loss, or, occasionally, mucopurulent or serous oculonasal discharge. This article describes an outbreak of chlamydiosis that occurred in a commercial psittacine breeding aviary in 2021 in Buenos Aires province, Argentina. In total, 16 juvenile blue-fronted parrots, more than 60 blue-fronted parrot chicks, and 2 adult macaws died during the outbreak. In all cases, clinical signs were weight loss, diarrhea, yellowish green excrement, and respiratory distress. The necropsy of four juvenile blue-fronted parrots, two blue-fronted parrot chicks, and two adult macaws revealed cachexia, hepatomegaly, splenomegaly, splenic petechial hemorrhages, ascites, pulmonary edema, and hydropericardium. Histologically, multifocal lymphoplasmacytic and heterophilic airsaculitis, multifocal lymphoplasmacytic and necrotizing hepatitis with intracytoplasmic elementary bodies, multifocal necro-heterophilic hepatitis, multifocal lymphoplasmacytic nephritis, and diffuse heterophilic pneumonia were found. A presumptive diagnosis was established based on gross and microscopic lesions, and it was confirmed using immunohistochemistry and polymerase chain reactions. The sequencing and phylogenetic analysis of the ompA gene revealed genotype A and B of Chlamydia psittaci.

Effect of Campylobacter fetus on in vitro fertilization and embryonic development of preimplantation bovine embryos.

Campylobacter fetus is an important veterinary pathogen that causes campylobacteriosis. This disease causes decreased productivity of cattle by inducing reproductive losses. Although several virulence factors have been recognized in C. fetus, including a cytolethal distending toxin (CDT), the exact mechanism responsible for embryonic death remains unknown. The aim of this work was to evaluate the effect of C. fetus subsp. fetus (Cff) and C. fetus subsp. venerealis (Cfv), and their toxin activity on the in vitro fertilization of bovine ova and early embryonic development. Two different experiments were performed. In Experiment 1, a total of 1524 cumulus-oocyte complexes (COCs) were inseminated, distributed into three groups: two of them infected with the microorganism (Cff, Cfv) and a control group. Percentages COCs cleaved were similar among groups (p = 0.1243); however, the embryonic development rate (blastocyst at day 7) in the control group was greater (p < 0.001) than those obtained in Cff and Cfv groups. In experiment 2, a total of 746 COCs were inseminated, divided into three groups: two of them treated with the bacterial-free culture filtrates to test toxin activity (Cff-CDT, Cfv-CDT) and a control group. Both cleavage and embryonic development rates were greater (p < 0.001) in the control group than those obtained in Cff-CDT and Cfv-CDT groups. This study provides evidence that both subspecies of C. fetus do not interfere with fertilization but do affect in vitro embryonic development. It is the first report on the biological effect of the CDT on bovine embryonic development.

Effects of Campylobacter fetus on bull sperm quality.

Campylobacter fetus is a gram-negative, motile, spiral or S-shaped bacterium, which induces campylobacteriosis. This disease causes decrease productivity of cattle. Although considerable research has been done on the role of C. fetus on female fertility, little is known about the effect on bulls. The aim of this work was to evaluate the effect of C. fetus subsp. fetus (Cff) and C. fetus subsp. venerealis (Cfv) on bull sperm quality. Samples of frozen semen (n = 29 straws) were each distributed into three groups: two of them incubated with the microorganism (Cff, Cfv) and a control group. The proportions of live spermatozoa, with functional membrane and true acrosomal reaction in control group were significantly (P < 0.01) greater than those observed in Cff and Cfv groups. However, no significant differences (P > 0.05) were found in sperm chromatin structure among treatments. In adhesion assay, proportions of spermatozoa with adhered Campylobacter were similar for both subspecies. Results confirm that Cff and Cfv have the same ability to bind in an irreversible way to bull spermatozoa and to affect sperm quality. It is proposed that adherence could be considered as the main cause of sperm alterations, and also an important step of pathogenesis and venereal transmission.

Quantitative analysis of campylobacter fetus venerealis adhesion to bovine reproductive tract cell cultures / Análise quantitativa da adesão de campylobacter fetus venerealis em culturas de células do aparelho reprodutor bovino

Campylobacter fetus is the etiological agent of bovine genital campylobacteriosis, a sexually transmitted disease which is associated with reproductive losses in bovines. Campylobacter colonizes the vagina and the uterus and then infects the epithelial cells of the endometrium. The objective of this work was to develop an ex vivo model to quantify the adhesion of Campylobacter to its natural specific target cells; this is a key step for the establishment of infection and studies regarding the adherence and cytotoxicity on the natural host cells are not available. The assays were carried out by seeding Campylobacter fetus venerealis on bovine vaginal and uterine epithelial cell cultures. HeLa cells were used as control. Bacterial adhesion was corroborated by optical microscopy and determination of the percentage of adherent bacteria was performed on immunochemically-stained slides. Results are presented as percentage of cells with adherent Campylobacter and as number of bacteria per cell. In comparison to the control HeLa cells, the statistical analysis revealed that primary cultures show a higher percentage of infected cells and a lower variation of the evaluated parameters. This primary culture model might be useful for studies on cytopathogenicity and adhesion of different field strains of Campylobacter fetus.

Campylobacter fetus é o agente etiológico da campilobacteriose genital bovina, uma doença sexualmente transmissível que está associada com perdas reprodutivas em bovinos. Campylobacter coloniza a vagina e o útero e então infecta as células epiteliais do endométrio. O objetivo deste trabalho foi desenvolver um modelo ex vivo para quantificar a adesão de Campylobacter às células-alvo naturais específicas; este é um passo fundamental para o estabelecimento da infecção e estudos acerca da adesão e citotoxicidade sobre as células do hospedeiro natural não estão disponíveis. Os ensaios foram realizados a través da semeadura de Campylobacter fetus venerealis em culturas celulares epiteliais vaginais e uterinas.Células HeLa foram utilizadas como controle.A aderência bacteriana foi confirmada por microscopia óptica e a determinação da porcentagem de bactérias aderidas foi realizada em lâminas tingidas imunoquimicamente. Os resultados são apresentados como porcentagem de células com Campylobacter aderente e como o número de bactérias por células. Em comparação com as células HeLa controle, a análise estatística revelou que as culturas primárias mostram uma maior porcentagem de células infectadas e uma menor variação dos parâmetros avaliados. Este modelo de cultura primária pode ser útil para estudos sobre citopatogenicidade e adesão de diferentes cepas de campo de Campylobacter fetus.