Variability Assessment of California Infectious Bronchitis Virus Variants.

On the basis of the data from the California Animal Health and Food Safety Laboratory System, 1444 infectious bronchitis (IB) cases were diagnosed between 1997 and 2012. Epidemiologic analyses demonstrated two major IB virus (IBV) outbreak peaks, affecting mainly 35-to-49-day-old broiler chickens. California variant 1737 (CA1737) and California variant 1999 (Cal 99) IBV types were the most prevalent genotypes during the analyzed period. To further understand the increased prevalence of these genotypes, we assessed and compared the variability of the S1 gene hypervariable region of CA1737 and Cal 99 with the variability of IBV strains belonging to the Massachusetts 41 (M41) and Arkansas (Ark) types during serial passages in embryonated chicken eggs. On the basis of the S1 nonsynonymous changes, seven different subpopulations were detected in M41. However, the predominant population of the field strain M41 before passages continued to be predominant throughout the experiment. In contrast, Ark passaging resulted in the detection of 13 different subpopulations, and the field sequence became extinct after the first passage. In IBV Cal 99, eight different subpopulations were detected; one of these became predominant after the second passage. In CA1737, 10 different subpopulations were detected. The field strain major sequence was not detected after the first passage but reappeared after the second passage and remained at low levels throughout the experiment. Compared with M41 and Ark, Cal 99 and CA1737 showed intermediate variability.

Anatomical study of the gastrointestinal tract of a pudu (Pudu puda) using contrast-enhanced abdominal computed tomography.

The pudu (Pudu puda), which is the smallest deer in the world and inhabits central and southern Chile and Argentina, is a ruminant and a browsing herbivore. The aim of this study was to provide a reference for interpretation of the normal anatomy of the pudu's gastrointestinal tract as imaged by abdominal computed tomography (CT). For the study, one adult female pudu was used. After a 24-h fast, the pudu was anaesthetized and positioned in sternal recumbency at the CT table. Image acquisition began immediately after intravenous injection of contrast media (MD-76(®); 370 mgI/ml) into the cephalic vein. Injection of contrast material was administered as a biphasic protocol. First, a manual bolus of contrast material was injected at a rate of 4 ml/s. Then, an additional continuous infusion injection (0.1 ml/min) was performed for adequate opacification of vascular structures. Transverse images of 5 mm thickness and 5 mm interval were obtained with a fourth-generation CT scanner, from the ninth thoracic vertebra (T9) until the first sacral (S1) vertebrae. CT images were labelled and compared with anatomical reference images for ruminants. Structures that were identified in the abdominal cavity included the stomach with its four compartments (rumen, reticulum, omasum and abomasum), the small and large intestines, liver, spleen, kidneys and some major blood vessels (aorta, caudal vena cava). The distal loop of the ascending colon, the transverse colon, the pancreas and lymph nodes could not be identified. The resulting CT images provide a reference for normal cross-sectional abdominal anatomy of the adult pudu.

Detection of mycobacterium avium subsp. paratuberculosis in a cattle/pudu interface / Detecção de mycobacterium avium subsp. paratuberculosis em uma interface gado/pudu

Mycobacterium avium subsp. paratuberculosis (Map) is the etiological agent of paratuberculosis. In Chile, information about Map isolation from both domestic ruminant and wildlife species has been accumulating, but it has to be extended to other species. The present study focuses specifically on one wild grazing species, the pudu (Pudu puda), one of the less known South American deer considered an endangered species that shares pastures with cattle in southern Chile, where the greatest part of the country's dairy cattle population is located. Convenient samples from 3 pudus were collected from one dairy farm where Map infection had previously been confirmed in cattle. All three pudus shed the bacterium in feces and the isolates are the same type of Map as described for cattle. This study represents the first case report of Map isolation in the pudu captured from the wild. It is also the first documented association between a Map-infected dairy herd and free-ranging wildlife species, such as pudu in the Los Ríos region, Chile. Since interspecies transmission of Map and other pathogens from livestock to pudu has already been demonstrated, the results from this study suggest that this free-ranging wildlife specie, inhabiting a dairy district in southern Chile, might represent another case of spillover host.

O agente etiológico da paratuberculose é o Mycobacterium avium subsp. paratuberculosis (Map). No Chile, já foi gerada informação do isolamento do Map em ruminantes domésticos e em algumas espécies selvagens, porém essa informação deve ser expandida a outras espécies. O presente estudo está focado na espécie selvagem herbívora, o Pudu (Pudu puda), que é considerado um dos cervos menos conhecidos da América do Sul, e que está em extinção. Essa espécie compartilha as pastagens com o gado no sul do Chile, local do país onde está concentrada a maior parte do rebanho leiteiro. Foram obtidas amostras de 3 pudus de uma fazenda de gado leiteiro, onde previamente havia sido confirmada a infecção por Map em bovinos. Os três pudus eliminavam a bactéria nas fezes, e os isolados fecais foram do mesmo tipo do Map relatado para os bovinos. Este estudo representa o primeiro relato de caso de isolamento do Map em pudu em vida silvestre. Também é a primeira associação documentada entre um rebanho leiteiro infectado com Map e a infecção de uma espécie silvestre de vida livre, tal como o pudu na região de Los Ríos, no Chile. A transmissão interespécies do Map, do mesmo modo que de outros patógenos de ruminantes para o pudu, já foi demonstrada, assim os resultados deste estudo sugerem que essa espécie de vida extensiva, que habita a mesma região leiteira no sul do Chile, pode representar mais um caso de repercussão ao hospedeiro.