We here identified for the first time the presence of Mycobacterium avium paratuberculosis (MAP) sheep (S) strain in Argentina. IS900 polymerase chain reaction (PCR) was positive. The S strain was compared with MAP cattle (C) strains by using IS1311 PCR-restriction endonuclease analysis (PCR-REA), multiplex PCR and restriction fragment length polymorphism (RFLP) analysis.

Guanaco, vicuña, alpaca and llama (Lama glama) are also known as Sudamerican camelids (SC). In Argentina llama was considered non profitable wildlife specie but now it is considered a mean for surviving because their meat, wool, leather and skin is valuable. SC are susceptible hosts of mycobacterial infections. A presumptive diagnosis is based on clinical and necropsy findings and is confirmed with bacterial isolation, molecular identification and histopathology. The objective of this publication is to describe a clinical case with clinical and necropsy findings consistent with paratuberculosis and its laboratory diagnosis in a captive llama from a zoo garden in Olavarría, Buenos Aires province. During necropsy granulomatous lesions resembling paratuberculosis in jejunum, ileon and mesenteric lymph nodes were observed. In direct smears and histopathology acid fast bacilli in clusters were detected. Mycobacterium avium subespecie avium was confirmed with bacteriology and the specific probe IS1245 was detected by PCR, IS900 Mycobacterium avium subespecie paratuberculosis specific probe was not demonstrated. These allowed confirming the etiology of a granulomatous enteritis case in llamas caused by Mycobacterium avium subespecie avium with clinical signs and lesions resembling paratuberculosis.

Los camélidos sudamericanos (CS) incluyen cuatro especies, guanaco, vicuña, alpaca y llama (Lama glama). En Argentina las llamas eran consideradas fauna y actualmente ganado, revalorizando su carne, fibra, cueros y pieles, también son un medio de subsistencia. Los CS son susceptibles a las enfermedades ocasionadas por micobacterias. El diagnóstico presuntivo se realiza por los signos clínicos y los hallazgos de necropsia y se confirma por técnicas bacteriológicas, moleculares e histopatología. El objetivo de este trabajo es describir un caso clínico con signos compatibles de paratuberculosis y el diagnóstico de laboratorio en una llama en cautiverio perteneciente a un zoológico de Olavarría, Provincia de Buenos Aires. En la necropsia se observaron lesiones granulomatosas en yeyuno, íleon y linfonodos mesentéricos compatibles con paratuberculosis, en los frotis directos y en la histopatología se observaron bacilos ácido-alcohol resistentes en cluster. Se confirmó la presencia de Mycobacterium avium subespecie avium por bacteriología y por PCR fue detectada la IS1245 característica de este agente, no detectando la IS900 correspondiente a Mycobacterium avium subespecie paratuberculosis. Esto permitió arribar al diagnóstico etiológico, combinando técnicas, de un caso de enteritis granulomatosa en llamas causado por Mycobacterium avium subespecie avium con signología y lesiones compatibles con paratuberculosis.

In the present study we evaluated different systems for the expression of mycobacterial antigen P36 secreted by Mycobacterium bovis. P36 was detected by Western blot using a specific antiserum. The P36 gene was initially expressed in E. coli, under the control of the T7 promoter, but severe proteolysis prevented its purification. We then tried to express P36 in M. smegmatis and insect cells. For M. smegmatis, we used three different plasmid vectors differing in copy number and in the presence of a promoter for expression of heterologous proteins. P36 was detected in the cell extract and culture supernatant in both expression systems and was recognized by sera from M. bovis-infected cattle. To compare the expression level and compartmentalization, the MPB70 antigen was also expressed. The highest production was reached in insect cell supernatants. In conclusion, M. smegmatis and especially the baculovirus expression system are good choices for the production of proteins from pathogenic mycobacteria for the development of mycobacterial vaccines and diagnostic reagents.