Numbers Of Acid-fast Bacteria Research Articles

Descriptive Report of Post-Mortem Diagnosis of Bovine Granulomatous Tubercular Pneumonia through Conventional Histological and Immunohistochemical Techniques

The study was aimed to diagnose the tubercular lesion of lung in bovine in spontaneous cases through histological and immunohistochemical techniques. In a year-long study of bovine pneumonia cases, 9 cases were suspected for granulomatous tubercular lesion. The tissues from the lesions were subjected for histological and immunohistological examination along with acid fast staining to see the presence of bacteria. The tubercle appeared as small to medium size was more pronounced in right cranial lobes in most of the cases. Histologically small to large granulomas with clusters of cells surrounding centrally caseous necrotic area were observed. The caseous necrotic areas had nuclear debris and were surrounded by granulomatous inflammatory reaction in which dense cluster of lymphocytes, epithelioid cell, macrophages and moderate amount of scattered Langhans’ giant cell. Staining with Ziehl Neelsen (ZN) stain, 7 cases showed low to high numbers of acid fast bacteria in lung section examined out of 9 cases. Immunohistological (IHC) staining with commercial anti-Mycobacterium tuberculosis polyclonal antibody showed positive reaction in Langhan’s giant cell, epithelioid cells and macrophages and in caseous necrotic tissues. As compared to ZN staining, the entire 9 samples were found positive for M tuberculosis antigen by IHC. Generally the intensity and number of positivity were much higher in IHC staining than ZN staining for acid fast bacilli. Thus, the present study shows that immunohistochemistry can be used over conventional histopathology and ZN staining in postmortem diagnosis of bovine tuberculosis and can be applied even in cases with small number of tubercle bacilli.

Death and Intracellular Degradation of Mycobacterium leprae after Exposure in vitro to Enzymic Free-Radical Generators

An increase in the resistance to sulphones and the prohibitive cost of rifampicin necessitate the development of new chemotherapeutic agents against leprosy. The 02dependent myeloperoxidase-mediated bactericidal system of Klebanoff ( 1975) and analogous free-radical and/or singlet-02 generators are suitable as first-choice candidates for this purpose. Such generators proved highly and readily effective in vitro against a variety of infectious agents (Klebanoff, 1975) including, among intralysosomal parasites, the three mycobacteria causing tuberculosis in man (Demoulin-Brahy et al., 1975) and Mycobacterium lepraemurium (R. J. W. Rees & P. J. Jacques, unpublished work; Avila et al., 1976). The approach and techniques were essentially those previously described (Delville et a[., 1976). Fresh suspensions of M. leprae were exposed in vitro at pH5 and 36°C in aerobic conditions to a mixture of fungal glucose oxidase, glucose, plant peroxidase and iodide or to a similar mixture lacking peroxidase and iodide, for either a few seconds or 1 h. The controls were incubated for 1 h in the same conditions, except that iodide and both enzymes were omitted. After washing the microbial preparation in the cold and resuspension, hind foot-pads of normal mice were inoculated with this resuspended preparation. At various times, ranging from 180 to 424 days after inoculation, the foot-pads were collected and processed for enumeration of total acidfast bacteria and for differentiation between granular and solid-stained bacteria (Shepard, 1960; Rees & Valentine, 1962). As shown in Table 1, contact in vitro of M. leprae with the complete oxidase mixture for only a few seconds resulted in a considerable decrease of the number of solid-stained (live) and granular (dead) mycobacteria that could be observed in mouse foot-pads up to 14 months after the treated microbial suspension had been transferred to that growth system in vivo. Since not a single acid-fast bacterium could be detected when treatment with the complete oxidase mixture had been applied for 1 h, we conclude that a true bactericidal action of the oxidative ‘cocktail’ has been observed. In addition, tissue concentration of the dead mycobacterium was considerably decreased Table 1. Effect of exposure in vitro of M. leprae to complete oxidase mixture on the number of acid-fast bacteria and viable counts Tabulated values are rneansks.~. for 12 individual results (ten for group with exposure for a few seconds only). The latter are mycobacterial counts expressed as percentage of total acid-fast bacteria in the corresponding control. The probability (P) was determined by Student’s t test applied to the population of individual differences.

マウス足蹠内へのらい菌接種

Four strains of mouse-passage M. leprae provided by Shepard were inoculated into the left hind foot-pads of CF#1 mice. The number of bacteria inoculated per foot-pad ranged from 7.89×102 to 2.37×103, 8.6 to 20.6% of which were stained solidly. The mice were housed in an animal room at 20±1°C, and fed the usual pelleted commercial chow. Three to four mice from a group of mice which were inoculated with a strain were sacrificed about 6 and 9 months after inoculation, and the inoculated foot-pads were dissected off and pooled for each harvest. The number of acid-fast bacteria was counted, the ratio of solidly staining bacteria determined and the generation time calculated.It was conclusively demonstrated that M. leprae could be transmitted to the mouse foot-pad. Multiplication of M. leprae was consistent but limited so that it reached a maximum logarithmic phase by about 6 months after inoculation, which was followed by a plateau phase. The calculated generation time from inoculation to a maximum logarithmic phase ranged from 18.2 to 23.6 days. The ratio of solidly staining bacteria rose during this period and declined later. The acid-fast bacteria from inoculum and harvest were inoculated to Ogawa's medium and incubated at 33° and 37°C for 3 months. No cultivable mycobacteria were isolated. Subcutaneous inoculation of the bacteria to mice failed to produce any lesions.

Growth of Small Numbers of Acid-fast Bacteria in Blood and in Serum.

The survival or growth of tubercle bacilli in blood is an important question from several points of view: the immunological action of serum and leucocytes, the investigation of tuberculous bacillemia, and the suitability of blood as a culture medium. Some investigators have emphasized the unfavorable action of blood on the growth of tubercle bacilli on solid media, while others have reported the growth of these organisms in blood. These points of view were reconciled when it was learned that the influence of blood in the two situations is quite different. This note indicates that, although blood interferes with the growth of tubercle bacilli on a solid substrate, it is actually an excellent medium.Saline, defibrinated rabbit blood, or serum, .45 cc, were mixed with .05 cc volumes of 4 decimal dilutions of “clump-free” suspensions of human, bovine, avian, and timothy bacilli in 10 × 75 mm Pyrex tubes. Of these mixtures .05 cc was spread evenly on each of two slants of Corper's egg-yolk medium (in screw-cap...

Growth Characteristics of Rough and Smooth Acid Fast Bacteria Living in Microculture

While studying the growth of a number of acid fast bacteria in microculture a series of micro motion pictures has been made of a strain of organisms pathogenic to frogs. This mycobacterium, M. ranae I, was provided by the Phipps Institute which obtained it several years ago from E. R. Baldwin. Planted at room temperature on the usual media it gives a rich white growth which at first often has the consistency of very thick cream but with age assumes the wrinkled growth more familiar in acid fast bacterial cultures. Both young and old growths are completely acid fast when stained by the Cooper modification of the Ziehl-Neelson technique. Dissociation was readily brought about by following Petroff's procedure of dilution platings on egg medium containing sodium taurocholate. The rough strain gives the usual wrinkled surface growth on fluid media. Streaked on solid it yields a coarse mealy mass. The smooth strain clouds glycerinated broth and produces a luxuriant mucoid growth on solid media. By transplantation from old Petroff bottles 2 S strains have recently been isolated which differ greatly from one another in their mucosity, one being so fluid that it will almost drip from the surface of an inverted Petri dish. Micro motion picture records show that these R and S dissociants grow in very different ways. The completely dissociated R organisms lie closely packed together as they multiply. They show little tendency to spread over the medium and commence early to overlie one another, forming thereby a thick tangled mass of bacilli. Micro colonies of the S organisms thus far photographed, on the other hand, strikingly resemble those of highly capsulated pneumococci. Several bacilli placed close together when seeding a micro field will not elongate for the first day or two.