Growth Of Mycobacterium Bovis Research Articles

Diversity-oriented synthesis of furo[3,2- f]chromanes with antimycobacterial activity

We previously reported the synthesis and the antimycobacterial activity of 4-(7,7-dimethyl-7 H-furo[3,2- f]chromen-2-yl)pyridine. From this result, we sought to design simple synthetic accesses to related structures allowing the preparation of a diverse set of analogues. Two approaches were investigated. From 3-(2-bromo-7,7-dimethyl-8,9-dihydro-7 H-furo[3,2- f]chromen-1-yl)propyl acetate, we prepared 2-arylated derivatives via Suzuki–Miyaura reactions between this bromine-bearing compound and various arylboronates. Moreover, and even more simple, we prepared the ((6-hydroxy-2,2,7,8-tetramethylchroman-5-yl)methyl)triphenylphosphonium salt via a selective bromination of 2,2,5,7,8-pentamethylchroman-6-ol. From this salt, a two stage Wittig reaction with an array of activated acids allowed the quick preparation of many analogues. The biological evaluation of the effect of these compounds on the growth of Mycobacterium bovis as well as Mycobacterium tuberculosis pointed out a fourfold improvement of the antimycobacterial properties for one of the compounds made. However, the many analogues which inhibited the growth of M. tuberculosis in the 0.6–5 μg/mL range turned out to be also cytotoxic on VERO cells growth at the same concentration range.

Pancreatic and psoas abscesses as a late complication of intravesical administration of bacillus Calmette-Guerin for bladder cancer: a case report and review of the literature

IntroductionBacillus Calmette-Guerin (BCG) is a live attenuated strain of Mycobacterium bovis that has been used to treat urothelial carcinoma since 1976, and has been reported to eradicate disease in more than 70% of patients with in situ and stage I disease. To the best of our knowledge, we report the first case of disseminated bacillus Calmette-Guerin infection causing multiple abscesses affecting the pancreatic head and right psoas muscle, diagnosed 5 years after intravesical treatment with bacillus Calmette-Guerin therapy for bladder cancer.Case presentationAn 83-year-old Caucasian man was hospitalized with a 2-month history of back pain, anorexia, generalized weakness and a 47-pound weight loss. He had previously undergone two transurethral resections for high-grade transitional cell carcinoma of the bladder and had received 12 intravesical bacillus Calmette-Guerin instillations without any complications. He complained of abdominal pain in his right flank. A computed tomography scan of the abdomen showed multiple abscesses affecting the pancreatic head and right psoas muscle. Growth of Mycobacterium bovis was determined in cultures of the purulent material obtained by surgical drainage of the abscesses.ConclusionsThis case illustrates the fact that although intravesical administration of bacillus Calmette-Guerin is generally considered to be safe, it is not exempt from complications and these could appear immediately after treatment or as a delayed complication many years later.

Growth of Mycobacterium bovis, Bacille Calmette-Guérin, within human monocytes-macrophages cultured in serum-free medium

Mycobacterium bovis BCG is an opportunistic agent that may be responsible for disseminated disease in immunocompromised individuals. Under physiological conditions, macrophages are the natural hosts and final killers of BCG. In the context of inherited or acquired immune disorders underlying disseminated BCG infections, macrophages fail to eradicate BCG or even to restrict its intracellular growth. The direct contribution of macrophages, in this setting of impaired BCG destruction, probably depends on the type of underlying immune deficiency and remains to be experimentally investigated. As an initial approach, we document here the fate of BCG within human monocytes and human monocyte-derived macrophages (MDMs) cultured in commercially available serum-free medium (M-SFM). This medium was used to avoid potential problems associated with human or animal serum-supplemented medium. We show here that both monocytes and MDMs cultured in M-SFM display the morphological features and functional activities expected for such cells. We also show that after an initial phase of intracellular destruction, BCG grow within infected monocytes–macrophages, as shown by colony forming unit (CFU) counts and Ziehl–Nielsen staining. By an electron microscopic analysis, we show that the BCG always reside within phagosomes and that 24-h postinfection many phagosomes stain for the hydrolytic enzyme acid phosphatase. Finally, we compare bacterial growth in vitro within phagocytes from healthy individuals and patients with chronic granulomatous disease (CGD), an inheritable condition associated with disseminated BCG infection in vivo. No destruction of intracellular BCG was achieved by the patients cells, revealing the essential mycobactericidal role of the respiratory burst in human phagocytes. Investigations of BCG growth within MDM cultured in M-SFM from patients with other conditions which predispose to clinical BCG infection is therefore warranted.

The use of aqueous cetylpyridinium chloride as a transport medium for suspected tuberculous tissues from badgers

Deterioration of tuberculous tissue specimens from badgers during transit in the post was simulated in the laboratory, and it was found that unpreserved tissues showing miliary lesions and initially producing a confluent growth of Mycobacterium bovis became culture-negative over a period of 4 days at ambient summer temperatures (>20 degrees C). These findings implied that false negative results may be obtained from specimens containing only small numbers of bacilli following delays of 2 days between collection and culture. A bench trial of cetyl pyridinium chloride and bromide as preservatives showed viable bacillary numbers were maintained well. A field trial of a 1% aqueous solution of the chloride salt as a transport medium was carried out on 666 split tissue submissions and a significantly improved isolation rate was found from the preserved samples, with 40 (93%) of the total of 43 isolates of M. bovis compared with 27 isolates (63%) when no preservative was used. Isolation using the guinea pig test was attempted on 354 of these samples and yielded 38 (93%) of the 41 isolates, compared with culture of preserved samples which yielded 39 isolates (95%), an insignificant difference. The use of this transport medium maximised cultural isolations, such that no significant gain was achieved by the continued use of the animal test.

Effect of T-cell depletion on the growth of BCG in the mouse footpad.

The growth of Mycobacterium bovis (BCG Montreal) and M. tuberculosis Erdman was determined in normal and T-cell depleted (THXB) mice when injected subcutaneously into a hind footpad. The bacilli multiplied only to a limited extent within the footpad itself but the infection quickly spread to the draining popliteal lymph node to eventually reach the liver, spleen and lung. The amount of systemic growth seen in the THXB mice was 10-100 times greater than in the normal controls, all of which developed a tuberculin hypersensitivity and an immune response in 14-18 days. T-cell depletion completely inhibited the expression of tuberculin sensitivity by the infected host as well as ablating the antituberculous response against both the vaccinating BCG population and a superinfecting Erdman challenge inoculum. Incorporation studies in the THXB mice indicated a striking reduction in cell division within the draining lymph node but there was an unexpected elevation in the level of incorporation by the lung cells as the BCG infection progressed. The significance of these findings is discussed in relation to the possible use of the BCG footpad model for studies of leprosy immunity.

Growth of mycobacterium bovis (BCG) in T lymphocyte-depleted mice.

BCG Montreal (10-6 viable bacilli) injected intravenously into adult thymectomized, irradiated, and bone marrow-reconstituted (THXB) C57Bl times C3H F1 hybrid mice induced a progressive systemic infection which killed 95% of the animals within 60 days. Control mice infected with this dose of BCG did not die. The infected THXB mice failed to develop detectable levels of tuberculin hypersensitivity although they did show considerable Arthus (3 h) reactivity. The BCG-infected THXB mice lost weight progressively, and the root spleen and root lung indices increased substantially as the infection proceeded. None of the THXB mice developed an antibacterial immune response to the systemic BCG infection, and this was reflected by the continued persistence of macroscopic lung granuloma in these animals. The BCG-infected control mice developed as many surface tubercles as did the THXB animals, but the granulomas rapidly regressed in size and numbers in the normal mice. The lung changes correlated with the amount of tritiated thymidine incorporated by the lung cells in the later stages of the BCG infection. T cell depletion depressed the early splenic peak normally seen in BCG-infected controls, but, on the other hand, there was a progressive increase in lung counts in the THXB mice as the infection progressed and this late peak was not seen in the control animals. The significance of these findings is discussed in relation to the development of antituberculous immunity by BCG-infected mice.

Effect of hyperimmune rabbit serum on intracellular growth of Mycobacterium bovis.

SummaryThe interaction between M. bovis and the J-111 cell was influenced by the serum component of a yeast extract-serum nutrient medium. Anti-BCG hyperimmune serum enhanced phagocytosis, suppressed intracellular growth, and prevented loss of infected cells to a greater extent than did normal or antityphoid sera.