Publications

Antigen fingerprinting based on surface glycolipid antigens was applied to the epidemiology of clinical isolates of the Mycobacterium avium complex from 128 acquired immunodeficiency syndrome (AIDS) and 31 non-AIDS patients from several different regions of Spain. The application of thin-layer chromatography, gas chromatography-mass spectrometry and monoclonal antibodies, combined with ELISA, allowed a facile identification, differentiation and classification of the isolates. The cumulative results demonstrate that, among the clinical isolates, serovar 4 was predominant in both AIDS (33.6%) and non-AIDS (22.6%) isolates. In general, the results demonstrate geographical as well as disease-related differences in the distribution of Myco. avium complex serovars of clinical importance.

Mycobacterium avium is the causative agent of the avian mycobacteriosis commonly known as avian tuberculosis (ATB). This infection causes disseminated disease, is difficult to diagnose, and is of serious concern because it causes significant mortality in birds. A new method was developed for processing specimens for an antemortem screening test for ATB. This novel method uses the zwitterionic detergent C18-carboxypropylbetaine (CB-18). Blood, bone marrow, bursa, and fecal specimens from 28 ducks and swabs of 20 lesions were processed with CB-18 for analysis by smear, culture, and polymerase chain reaction (PCR). Postmortem examination confirmed nine of these birds as either positive or highly suspect for disseminated disease. The sensitivities of smear, culture, and PCR, relative to postmortem analysis and independent of specimen type, were 44.4%, 88.9%, and 100%, respectively, and the specificities were 84.2%, 57.9%, and 15.8%, respectively. Reductions in specificity were due primarily to results among fecal specimens. However, these results were clustered among a subset of birds, suggesting that these tests actually identified birds in early stages of the disease. Restriction fragment length polymorphism mapping identified one strain of M. avium (serotype 1) that was isolated from lesions, bursa, bone marrow, blood, and feces of all but three of the culture-positive birds. In birds with confirmed disease, blood had the lowest sensitivity and the highest specificity by all diagnostic methods. Swabs of lesions provided the highest sensitivity by smear and culture (33.3% and 77.8%, respectively), whereas fecal specimens had the highest sensitivity by PCR (77.8%). The results of this study indicate that processing fecal specimens with CB-18, followed by PCR analysis, may provide a valuable first step for monitoring the presence of ATB in birds.