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Cloud JL, Shutt C, Aldous W, Woods G. Evaluation of a modified gen-probe amplified direct test for detection of Mycobacterium tuberculosis complex organisms in cerebrospinal fluid. J Clin Microbiol 2005; 42:5341-4. [PMID: 15528738 PMCID: PMC525225 DOI: 10.1128/jcm.42.11.5341-5344.2004] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Laboratory evidence for tuberculous meningitis is difficult to acquire due to the low numbers of organisms present in cerebrospinal fluid (CSF) and the presence of nucleic acid amplification inhibitors. The Amplified Mycobacterium tuberculosis Direct Test (MTD) is sensitive and specific for the direct detection of M. tuberculosis complex in respiratory samples but has not been approved for CSF. We evaluated a modified version of the current MTD, optimized for use with CSF samples. Samples were prepared by spiking CSF with various numbers of M. tuberculosis complex organisms. The modified MTD performance was compared with results obtained using a purified RNA sample extracted using the Qiagen RNeasy Protect Bacteria Mini Kit. By use of CSF artificially spiked with M. tuberculosis complex, the sensitivity of the modified MTD was 100% (six of six) for CSF samples containing approximately 600 CFU/ml, 78% (seven of nine) for approximately 60 CFU/ml, 50% (three of six) for 6 CFU/ml, and 17% (one of six) for samples with <1 CFU/ml. The specificity of the modified MTD method was 100% (22 of 22). The sensitivity of the Qiagen MTD method was 100% for CSF samples containing approximately 600 CFU/ml (six of six) and approximately 60 CFU/ml (nine of nine), 50% for samples with approximately 6 CFU/ml (three of six), and 50% for samples with <1 CFU/ml (three of six). The specificity of the Qiagen MTD method was 86% (19 of 22). With the Qiagen MTD method, however, initial results were equivocal for 14 of the 27 (52%) positive samples, requiring repeat analysis, whereas with the modified MTD, only 1 of 27 (4%) was equivocal. The modified MTD for CSF samples was less time-consuming and less expensive and resulted in considerably fewer equivocal results than the Qiagen MTD method did.
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Affiliation(s)
- Joann L Cloud
- ARUP Institute for Clinical and Experimental Pathology, 500 Chipeta Way, Salt Lake City, UT 84108, USA.
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52
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Jin ZH, Lin JP, Cen PL. Scale-up of rifamycin B fermentation with Amycolatoposis mediterranei. JOURNAL OF ZHEJIANG UNIVERSITY. SCIENCE 2004; 5:1590-1596. [PMID: 15547969 DOI: 10.1631/jzus.2004.1590] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Study of the effect of dissolved oxygen and shear stress on rifamycin B fermentation with A. mediterranei XC 9-25 showed that rifamycin B fermentation with Amycolatoposis mediterranei XC 9-25 needs high dissolved oxygen and is not very sensitive to shearing stress. The scale-up of rifamycin B fermentation with A. mediterranei XC 9-25 from a shaking flask to a 15 L fermentor was realized by controlling the dissolved oxygen to above 25% of saturation in the fermentation process, and the potency of rifamycin B fermentation in the 15 L fermentor reached 10 g/L after 6-day batch fermentation. By continuously feeding glucose and ammonia in the fermentation process, the potency of rifamycin B fermentaion in the 15 L fermentor reached 18.67 g/L, which was 86.65% higher than that of batch fermentation. Based on the scale-up principle of constantly aerated agitation power per unit volume, the scale-up of rifamycin B fed-batch fermentation with continuous feed from a 15 L fermentor to a 7 m(3) fermentor and further to a 60 m(3) fermentor was realized successfully. The potency of rifamycin B fermentation in the 7 m(3) fermentor and in the 60 m(3) fermentor reached 17.25 g/L and 19.11 g/L, respectively.
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Affiliation(s)
- Zhi-Hua Jin
- Institute of Bioengineering, School of Materials Science and Chemical Engineering, Zhejiang University, Hangzhou 310027, China
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53
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Vidal JE, Hernández AV, Oliveira ACPD, de Souza AL, Souza DA, Madalosso G, Silva PRMD, Dauar R. Cerebral tuberculomas in AIDS patients: a forgotten diagnosis? ARQUIVOS DE NEURO-PSIQUIATRIA 2004; 62:793-6. [PMID: 15476071 DOI: 10.1590/s0004-282x2004000500010] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The human immunodeficiency virus (HIV) infection epidemics increased the prevalence, multi-drug resistance and disseminated forms of tuberculosis. The central nervous system (CNS) tuberculosis has high mortality and morbidity, and it is usually divided into diffuse (meningitis) and localized (tuberculoma and abscess) forms. We report three cases of cerebral tuberculomas in AIDS patients: one with definitive diagnosis, confirmed with histopathology, and two with probable diagnosis, based on clinical information, radiological images, Mycobaterium tuberculosis isolation out of the CNS and adequate response to antituberculous treatment. Further, we discuss diagnostic, therapeutic and prognostic issues of tuberculomas, with emphasis in the distinction from cerebral tuberculous abscesses. Despite of their infrequent presentation, tuberculomas should be considered in the differential diagnosis of cerebral expansive lesions in patients with AIDS.
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Affiliation(s)
- José E Vidal
- Department of Infectology, Institute of Infectious Disease Emilio Ribas, São Paulo SP, Brazil.
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54
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Borges M, Cafrune PI, Possuelo LG, Valim ARDM, Ribeiro MO, Rossetti MLR. Análise molecular de cepas de Mycobacterium tuberculosis provenientes de um centro de saúde ambulatorial em Porto Alegre, (RS). J Bras Pneumol 2004. [DOI: 10.1590/s1806-37132004000400010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
INTRODUÇÃO: A tuberculose é uma doença antiga que ainda se mantém como um dos maiores males da humanidade no século XXI. Nas últimas décadas, o advento de novas tecnologias utilizando os conhecimentos de biologia molecular tem levado a um aumento na investigação da etiologia, detecção e epidemiologia da tuberculose. OBJETIVO: Avaliar o grau de similaridade entre as cepas de Mycobacterium tuberculosis provenientes do setor de tisiologia do Centro de Saúde Navegantes, de Porto Alegre (RS). MÉTODO: Foi realizado um estudo retrospectivo utilizando 55 amostras de escarro de pacientes atendidos ambulatorialmente no Centro de Saúde Navegantes para realização da técnica de RFLP. Os resultados obtidos pela genotipagem foram correlacionados com os dados gerados a partir da epidemiologia convencional. RESULTADOS: Trinta e nove isolados (70,9%) apresentaram padrão único, enquanto dezesseis isolados (29,1%) apresentaram padrões agrupáveis e formaram 8 clusters, com 2 pacientes em cada. Foi encontrada relação epidemiológica em 6 (37,5%) dos 16 pacientes em cluster. CONCLUSÃO: A associação adequada entre epidemiologia convencional e genotipagem de M. tuberculosis contribui para um melhor entendimento da dinâmica de transmissão da tuberculose mesmo quando o estudo é realizado em um único local.
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55
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Paolo WF, Nosanchuk JD. Tuberculosis in New York city: recent lessons and a look ahead. THE LANCET. INFECTIOUS DISEASES 2004; 4:287-93. [PMID: 15120345 DOI: 10.1016/s1473-3099(04)01004-7] [Citation(s) in RCA: 78] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
In the late 1980s and early 1990s, after decades of decline, the incidence of tuberculosis began to rise in New York city, reaching a peak of 3811 cases by 1992. The epidemic took root in a setting of inadequate treatment regimens, homelessness, a diminished public-health system, and the onset of the HIV/AIDS epidemic. In addition, a subepidemic of drug-resistant tuberculosis occurred throughout New York city, most notably in a series of well documented nosocomial outbreaks. By 1994, using broadened initial treatment regimens, directly observed therapy, and improved US Centers for Disease Control and Prevention guidelines for hospital control and disease prevention, New York city began to effectively halt the progression of the epidemic. By 2002, tuberculosis rates in New York city reached an historic low of 1084. However, given the presence of a large reservoir of latently infected individuals in the city and an ongoing tuberculosis pandemic, New York city continues to face significant challenges from this persistent pathogen.
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Affiliation(s)
- William F Paolo
- Department of Medicine, Division of Infectious Diseases, Albert Einstein College of Medicine, Bronx, New York, USA
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56
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Dannaoui E, Lortholary O, Dromer F. In vitro evaluation of double and triple combinations of antifungal drugs against Aspergillus fumigatus and Aspergillus terreus. Antimicrob Agents Chemother 2004; 48:970-8. [PMID: 14982791 PMCID: PMC353155 DOI: 10.1128/aac.48.3.970-978.2004] [Citation(s) in RCA: 81] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Microdilution broth checkerboard techniques based on the National Committee for Clinical Laboratory Standards methodology were used to study double and triple antifungal combinations against clinical isolates of Aspergillus fumigatus and A. terreus. The influences of the end-point definition (partial or complete inhibition) and the mode of reading (visually or spectrophotometrically) were determined. Interactions between antifungal drugs were also evaluated by agar diffusion tests. Combinations of caspofungin with either amphotericin B or voriconazole were additive for all the isolates, and antagonism was not observed. The interaction between caspofungin and flucytosine was synergistic for 62% of the isolates. In contrast, the interaction between voriconazole and flucytosine was never synergistic and antagonism was noted for 93% of the isolates. The triple combination of caspofungin with flucytosine and amphotericin B was synergistic for all the isolates tested. The triple combination of caspofungin with flucytosine and voriconazole was also mostly synergistic; but complex interactions were obtained for some isolates, with synergy or antagonism depending on the concentrations of caspofungin and voriconazole. Analysis of the influence of the reading technique on the results showed that spectrophotometric reading was a good alternative to the recommended visual reading. The results of these in vitro tests suggest that the activity of flucytosine as part of a double combination with caspofungin and as part of a triple combination with caspofungin and amphotericin B against Aspergillus spp. warrants further investigations. Animal studies are needed to evaluate the in vivo efficacies of these combinations.
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Affiliation(s)
- Eric Dannaoui
- Centre National de Référence Mycologie et Antifongiques, Unité de Mycologie Moléculaire, Institut Pasteur, 75724 Paris Cedex 15, France.
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57
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Bapat PM, Wangikar PP. Optimization of rifamycin B fermentation in shake flasks via a machine-learning-based approach. Biotechnol Bioeng 2004; 86:201-8. [PMID: 15052640 DOI: 10.1002/bit.20056] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Rifamycin B is an important polyketide antibiotic used in the treatment of tuberculosis and leprosy. We present results on medium optimization for Rifamycin B production via a barbital insensitive mutant strain of Amycolatopsis mediterranei S699. Machine-learning approaches such as Genetic algorithm (GA), Neighborhood analysis (NA) and Decision Tree technique (DT) were explored for optimizing the medium composition. Genetic algorithm was applied as a global search algorithm while NA was used for a guided local search and to develop medium predictors. The fermentation medium for Rifamycin B consisted of nine components. A large number of distinct medium compositions are possible by variation of concentration of each component. This presents a large combinatorial search space. Optimization was achieved within five generations via GA as well as NA. These five generations consisted of 178 shake-flask experiments, which is a small fraction of the search space. We detected multiple optima in the form of 11 distinct medium combinations. These medium combinations provided over 600% improvement in Rifamycin B productivity. Genetic algorithm performed better in optimizing fermentation medium as compared to NA. The Decision Tree technique revealed the media-media interactions qualitatively in the form of sets of rules for medium composition that give high as well as low productivity.
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Affiliation(s)
- Prashant M Bapat
- Department of Chemical Engineering, Indian Institute of Technology, Bombay, Powai, Mumbai 400 076, India
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58
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Eguchi J, Ishihara K, Watanabe A, Fukumoto Y, Okuda K. PCR method is essential for detecting Mycobacterium tuberculosis in oral cavity samples. ORAL MICROBIOLOGY AND IMMUNOLOGY 2003; 18:156-9. [PMID: 12753466 DOI: 10.1034/j.1399-302x.2003.00050.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Tuberculosis is a re-emerging infectious disease, and infection by Mycobacterium tuberculosis has been increasing in immunocompromised hosts, including elderly persons. M. tuberculosis-infected persons may receive dental treatment. To evaluate the risk of M. tuberculosis infection in dental clinics, we examined the detection rates of M. tuberculosis in sample of mixed saliva, dental plaque, extracted teeth, caries lesions, and denture plaque by nested polymerase chain reaction (PCR). The detection rates by PCR in samples from mixed saliva, dental plaque, caries lesions and denture plaque obtained from tuberculosis patients were 98.0%, 92.0%, 89.0%, and 100%, respectively. The detection rates by the culture method were 17.3%, 2.0%, 0%, and 0%, respectively. M. tuberculosis also was detected from the nontuberculous mycobacteria-infected group. Strains of Actinomyces naeslundii, Porphyromonas gingivalis, and Fusobacterium nucleatum inhibited the growth of clinical strains of M. tuberculosis, but strains of Streptococcus mutans, Streptococcus sanguinis, and Actinobacillus actinomycetemcomitans did not. The present study concludes that the PCR method is essential for detecting M. tuberculosis in oral samples.
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Affiliation(s)
- J Eguchi
- Department of Microbiology, Tokyo Dental College, Chiba, Japan
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59
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Ahmad S, Ali MM, Mustafa AS. Construction of a modified vector for efficient purification of recombinant Mycobacterium tuberculosis proteins expressed in Escherichia coli. Protein Expr Purif 2003; 29:167-75. [PMID: 12767806 DOI: 10.1016/s1046-5928(03)00052-4] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A major problem in assessing the vaccine and diagnostic potential of various proteins encoded by Mycobacterium tuberculosis genome is the inability to produce large quantities of these proteins, even when Escherichia coli or other heterologous systems are employed for recombinant protein production. To overcome these barriers, we have constructed a modified expression vector, using pGEX-4T-1 vector as the backbone. In addition to the features offered by the pGEX-4T vectors, the new vector allowed easy purification of recombinant proteins on the highly versatile Ni-NTA-agarose affinity matrix. The utility of the new vector was demonstrated by expressing and purifying, to near homogeneity, two M. tuberculosis proteins, i.e., Rv3872 (a member of the multi-gene PE subfamily) and Rv3873 (a member of the multi-gene PPE subfamily), which are encoded by the RD1 region of M. tuberculosis. The proteins encoded by rv3872 and rv3873 were expressed at high levels as fusion proteins with glutathione-S-transferase in E. coli. The recombinant Rv3872 and Rv3873 proteins were purified and isolated free of the fusion partner (GST) by affinity purification on glutathione-Sepharose and/or Ni-NTA-agarose affinity matrix and cleavage of the purified fusion proteins by thrombin protease. The recombinant Rv3872 protein was nearly homogeneous (more than 95% pure) while Rv3873 preparation was more than 90% pure. The recombinant Rv3872 and Rv3873 proteins were immunologically active and reacted with antibodies in sera from TB patients. Our results demonstrate the utility of the newly constructed expression vector with two affinity tags for efficient expression and purification of recombinant M. tuberculosis proteins expressed in E. coli, which could be used for further diagnostic and immunological studies.
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Affiliation(s)
- Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, Safat 13110, Kuwait.
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60
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Xu J, Mahmud T, Floss HG. Isolation and characterization of 27-O-demethylrifamycin SV methyltransferase provides new insights into the post-PKS modification steps during the biosynthesis of the antitubercular drug rifamycin B by Amycolatopsis mediterranei S699. Arch Biochem Biophys 2003; 411:277-88. [PMID: 12623077 DOI: 10.1016/s0003-9861(03)00004-3] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The gene rif orf14 in the rifamycin biosynthetic gene cluster of Amycolatopsis mediterranei S699, producer of the antitubercular drug rifamycin B, encodes a protein of 272 amino acids identified as an AdoMet: 27-O-demethylrifamycin SV methyltransferase. Frameshift inactivation of rif orf14 generated a mutant of A. mediterranei S699 that produces no rifamycin B, but accumulates 27-O-demethylrifamycin SV (DMRSV) as the major new metabolite, together with a small quantity of 27-O-demethyl-25-O-desacetylrifamycin SV (DMDARSV). Heterologous expression of rif orf14 in Escherichia coli yielded a 33.8-kDa polyhistidine-tagged polypeptide, which efficiently catalyzes the methylation of DMRSV to rifamycin SV, but not that of DMDARSV or rifamycin W. 27-O-Demethylrifamycin S was methylated poorly, if at all, by the enzyme to produce rifamycin S. The purified enzyme does not require a divalent cation for catalytic activity. While Ca(2+) or Mg(2+) inhibits the enzyme activity slightly, Zn(2+), Ni(2+), and Co(2+) are strongly inhibitory. The K(m) values for DMRSV and S-adenosyl-L-methionine (AdoMet) are 18.0 and 19.3 microM, respectively, and the K(cat) is 87s(-1). The results indicate that DMRSV is a direct precursor of rifamycin SV and that acetylation of the C-25 hydroxyl group must precede the methylation reaction. They also suggest that rifamycin S is not the precursor of rifamycin SV in rifamycin B biosynthesis, but rather an oxidative shunt-product.
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Affiliation(s)
- Jun Xu
- Department of Chemistry, University of Washington, Box 351700, Seattle, WA 98195-1700, USA
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61
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Vidal JE, Cimerman S, da Silva PRM, Sztajnbok J, Coelho JFGS, Lins DLM. Tuberculous brain abscess in a patient with AIDS: case report and literature review. Rev Inst Med Trop Sao Paulo 2003; 45:111-4. [PMID: 12754580 DOI: 10.1590/s0036-46652003000200013] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Tuberculous brain abscesses in AIDS patients are considered rare with only eight cases reported in the literature. We describe the case of a 34-year-old woman with AIDS and previous toxoplasmic encephalitis who was admitted due to headache and seizures. A brain computed tomography scan disclosed a frontal hypodense lesion with a contrast ring enhancement. Brain abscess was suspected and she underwent a lesion puncture through a trepanation. The material extracted was purulent and the acid-fast smear was markedly positive. Timely medical and surgical approaches allowed a good outcome. Tuberculous abscesses should be considered in the differential diagnosis of focal brain lesions in AIDS patients. Surgical excision or stereotactic aspiration, and antituberculous treatment are the mainstay in the management of these uncommon lesions.
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Affiliation(s)
- José E Vidal
- Instituto de Infectologia Emílio Ribas, São Paulo, SP, Brazil.
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62
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Rodríguez JC, Ruiz M, López M, Royo G. In vitro activity of moxifloxacin, levofloxacin, gatifloxacin and linezolid against Mycobacterium tuberculosis. Int J Antimicrob Agents 2002; 20:464-7. [PMID: 12458143 DOI: 10.1016/s0924-8579(02)00239-x] [Citation(s) in RCA: 116] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The in vitro activity of moxifloxacin, gatifloxacin, levofloxacin and linezolid was evaluated against 234 strains of Mycobacterium tuberculosis isolated in the Southeast of Spain. All drugs tested showed good activity, with an MIC(90) of less than 1 mg/l, and were active against isociacide and rifampicin resistant strains. Three strains were resistant to isoniazid and to the fluoroquinolones, which suggested the existence of mechanisms of resistance not yet described. These new compounds may prove to be therapeutic alternatives for treatment of multi-resistant tuberculosis and further studies should be done to demonstrate their true usefulness.
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Affiliation(s)
- J C Rodríguez
- Section of Microbiology, Hospital General Universitario de Elche, Universidad Miguel Hernández, 03202 Elche, Alicante, Spain.
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63
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Jin ZH, Lin JP, Xu ZN, Cen PL. Improvement of industry-applied rifamycin B-producing strain, Amycolatopsis mediterranei, by rational screening. J GEN APPL MICROBIOL 2002; 48:329-34. [PMID: 12682871 DOI: 10.2323/jgam.48.329] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
An industrially applied rifamycin B-producing strain, Amycolatopsis mediterranei XC 1-02, was used for further screening. A special mutation and screening procedure was adopted to select a strain, which can alleviate the inhibition caused by both aromatic amino acid and p-hydroxybenzoic acid in the pathway of rifamycin B biosynthesis as well as enhance the production of propionate, one of the precursors of rifamycin B biosynthesis. By the above methods, a strain A. mediterranei XC 9-25 was obtained, and its rifamycin B productivity in shaking flask reaches 10 g/L, which is 2.38 times higher than that of the ancestral strain XC 1-02. The productivity of rifamycin B fed-batch fermentation in 60000 L fermentor with A. mediterranei XC 9-25 reached 19.11 g/L.
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Affiliation(s)
- Zhi Hua Jin
- Institute of Bioengineering, College of Materials Science and Chemical Engineering, Zhejiang University, Hangzhou 310027, P. R. China
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64
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Ahmad S, Mokaddas E, Fares E. Characterization of rpoB mutations in rifampin-resistant clinical Mycobacterium tuberculosis isolates from Kuwait and Dubai. Diagn Microbiol Infect Dis 2002; 44:245-52. [PMID: 12493171 DOI: 10.1016/s0732-8893(02)00457-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Mutations conferring resistance to rifampin in rifampin-resistant clinical Mycobacterium tuberculosis isolates occur mostly in the 81 bp rifampin-resistance-determining region (RRDR) of the rpoB gene. In this study, 29 rifampin-resistant and 12 -susceptible clinical M. tuberculosis isolates were tested for characterization of mutations in the rpoB gene by line probe (INNO-LiPA Rif. TB) assay and the results were confirmed and extended by DNA sequencing of the PCR amplified target DNA. The line probe assay identified all 12 susceptible strains as rifampin-sensitive and the DNA sequence of RRDR in the amplified rpoB gene from two isolates matched perfectly with the wild-type sequence. The line probe assay identified 28 resistant isolates as rifampin-resistant with specific detection of mutation in 22 isolates including one isolate that exhibited hetro-resistance containing both the wild-type pattern as well as a specific mutation within RRDR while one of the rifampin-resistant strain was identified as rifampin-susceptible. DNA sequencing confirmed these results and, in addition, led to the specific detection of mutations in 5 rifampin-resistant isolates in which specific base changes within RRDR could not be determined by the line probe assay. These analyses identified 8 different mutations within RRDR of the rpoB gene including one novel mutation (S522W) that has not been reported so far. The genotyping performed on the isolates carrying similar mutations showed that majority of these isolates were unique as they exhibited varying DNA banding patterns. Correlating the ethnic origin of the infected TB patients with the occurrence of specific mutations at three main codon positions (516, 526 and 531) in the rpoB gene showed that most patients (11 of 15) from South Asian region contained mutations at codon 526 while majority of isolates from patients (6 of 11) of Middle Eastern origin contained mutations at codon 531.
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Affiliation(s)
- Suhail Ahmad
- Department of Microbiology, Faculty of Medicine, Kuwait University, P.O. Box 24923, 13110, Safat, Kuwait.
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65
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Lledó L, Gegúndez MI, Saz JV, Beltrán M. [Preliminary evaluation of the prevalence of tuberculosis infection in an occupational risk group]. Enferm Infecc Microbiol Clin 2002; 20:332-4. [PMID: 12236999 DOI: 10.1016/s0213-005x(02)72810-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND The aim of this study was to gain knowledge on the prevalence of tuberculosis infection in occupational groups whose professional activity could implicate a high risk of contact with persons infected with Mycobacterium tuberculosis. Additionally, we sought to identify risk factors in order to establish effective measures for control and prevention. With this aim we carried out a pilot study among members of our police force. MATERIAL AND METHODS Reactivity against tuberculin was tested in 150 individuals belonging to the Spanish National Police Force and an epidemiological survey was conducted to identify risk factors. RESULTS The prevalence of tuberculin reactivity was 10.7%. No correlation was found between positive testing and sex or years of service, but there was a correlation with respect to age. CONCLUSIONS The prevalence data and the experience obtained in this pilot study enable us to continue working toward the establishment of an effective control program.
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Affiliation(s)
- Lourdes Lledó
- Departamento de Microbiología y Parasitología, Facultad de Medicina, Universidad Alcalá de Henares, Madrid, España.
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66
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Sharaf-Eldin GS, Saeed NS, Hamid ME, Jordaan AM, Van der Spuy GD, Warren RM, Van Helden PD, Victor TC. Molecular analysis of clinical isolates of Mycobacterium tuberculosis collected from patients with persistent disease in the Khartoum region of Sudan. J Infect 2002; 44:244-51. [PMID: 12099732 DOI: 10.1053/jinf.2001.0992] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
SETTING Patients with positive smears for acid-fast bacilli were enrolled at tuberculosis (TB) clinics in the Khartoum region of Sudan. OBJECTIVE To identify the presence of drug resistant genotypes in M. tuberculosis isolates which are difficult to treat. METHODS Genus specific PCR-SSCP was performed to confirm the presence of M. tuberculosis in clinical isolates. Genotypic drug resistance testing was performed by mutation analysis and spoligotyping was used to monitor transmission and to identify epidemic strains. RESULTS Fifty (48%) of the original 105 samples were classified as M. tuberculosis. Four (4%) of the samples were typed as mycobacteria other than TB, while the remaining (n =50) samples were refractory to further molecular analysis. The fifty amplifiable M. tuberculosis samples were used for subsequent mutation analysis and typing. Mutations were identified in the genes conferring resistance to INH (kat G, 12%), RIF (rpoB, 8%), SM (r psL and rrs, 30%) and EMB (embB, 4%). Two of the samples (4%) had mutations in genes associated to both INH and RIF and can be classified as MDR-TB. Thirty-three percent (13/39) of the persistant tuberculosis cases (5/18 treatment failure; 5/14 relapse; 3/7 defaulter) had mutations accounting for drug resistance. A total of 27 different spoligotypes were identified from 49/50 samples. Twenty-nine (59%) of the isolates were grouped into one of seven clusters, while 20 (41%) showed unique patterns. One patient was infected with M. bovis. CONCLUSION This is the first molecular approach to characterize clinical isolates of M. tuberculosis from Sudan. The results show that drug resistance is indeed a serious problem and it may compliment the efforts of the National Tuberculosis Programme to improve strategies to control this disease.
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Aznar J, Safi H, Conejo MC, Palomares JC. Molecular epidemiology of tuberculosis in a prison facility in Seville: a 3-year study (1993--95). Clin Microbiol Infect 2002; 3:586-588. [PMID: 11864192 DOI: 10.1111/j.1469-0691.1997.tb00318.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Javier Aznar
- Dpto Microbiologia, Apdo 914, Universidad de Sevilla, 41080-Sevilla, Spain
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68
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Pompeo F, Mushtaq A, Sim E. Expression and purification of the rifamycin amide synthase, RifF, an enzyme homologous to the prokaryotic arylamine N-acetyltransferases. Protein Expr Purif 2002; 24:138-51. [PMID: 11812235 DOI: 10.1006/prep.2001.1550] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The assembly of the polyketide backbone of rifamycin B by the type I rifamycin polyketide synthase, encoded by the rifA-rifE genes, is terminated by the product of the rifF gene, an amide synthase that releases the completed undecaketide as its macrocyclic lactam. The sequence of the RifF protein from Amycolatopsis mediterranei shows 26% identity and 40% homology with the members of the arylamine N-acetyltransferase (NAT) family of proteins. Based on the homology of the primary structures and the similarity of the reactions catalyzed by the two enzymes, we have compared the RifF protein with members of the NAT family. We have modeled the three-dimensional (3D) structure of RifF using NAT from Salmonella typhimurium and Mycobacterium smegmatis as a template. Proteolytic digestions of RifF revealed accessible regions in the protein which are in agreement with the modeled structure. We have expressed the whole protein and individual domains of the protein based on comparison with NAT from S. typhimurium and have purified the proteins by affinity chromatography using a hexahistidine tag. RifF has been further purified using ion-exchange (Mono Q) chromatography. An antiserum has been generated using the C-terminal nona- and tridecapeptides of RifF and has been shown to recognize RifF uniquely. It does not cross-react with any other member of the NAT family.
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Affiliation(s)
- Frédérique Pompeo
- Department of Pharmacology, University of Oxford, Mansfield Road, Oxford OX1 3QT, United Kingdom
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69
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Fernández De La Hoz K, Fernández S, Ordobás M, Gómez P, Fernández M, Arce A. [Compliance of antituberculosis therapy among ex-inmates in the Madrid area]. Enferm Infecc Microbiol Clin 2001; 19:362-6. [PMID: 11602136 DOI: 10.1016/s0213-005x(01)72667-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
BACKGROUND The inmate population is not a tight compartment without communication with the community but there is a flow of persons and thus of health problems. The high incidence of tuberculosis among inmates is therefore of concern for the Public Health System. METHODS The outcomes of antituberculosis treatment among ex-inmates released from prison in 1987 in the Madrid Area were evaluated and compared with those who remained in jail on treatment. Individuals who met the case definition of tuberculosis were included in the study. The outcome was defined as the individual status one year after the beginning of therapy. To determine the association between the study variables with outcome, odds ratios (OR) with their 95% confidence intervals were used. The Chi2 test was used to determine the statistical significance. RESULTS Differences between outcomes of individuals in the two groups were observed: 69.7% of inmates had completed their therapy compared with 20.5% of ex-inmates. Treatment had to be prolonged in 15.2% of inmates compared with 46.2% in ex-inmates. The only predictor associated with therapy completion one year after the beginning was imprisonment, as OR for not having completed therapy for ex-inmates was almost 13 times higher (OR=12.94; 95% IC, 3.38-13.10) than those in jail. CONCLUSIONS Special strategies should be developed that assure clinical cure of persons with factors related to non-compliance.
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Affiliation(s)
- K Fernández De La Hoz
- Subdirección General de Sanidad Penitenciaria, Dirección General de Instituciones Penitenciarias, de Madrid, Spain.
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70
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Lee LK, Dinneen MD, Ahmad S. The urologist and the patient infected with human immunodeficiency virus or with acquired immunodeficiency syndrome. BJU Int 2001; 88:500-10. [PMID: 11678742 DOI: 10.1046/j.1464-410x.2001.02376.x] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Affiliation(s)
- L K Lee
- Department of Urology, Royal Bolton Hospitals, Lancashire, UK.
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71
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Brienze VM, Pereira FJ, Liso E, Tognola WA, dos Santos MA, Ferreira MU. Low sensitivity of polymerase chain reaction for diagnosis of tuberculous meningitis in southeastern Brazil. Rev Soc Bras Med Trop 2001; 34:389-93. [PMID: 11562736 DOI: 10.1590/s0037-86822001000400015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
Two polymerase chain reaction (PCR) protocols showed low sensitivity (36% and 53% for TB AMPLICOR and MPB64 nested PCR, respectively), when compared with classic microbiological methods (73% and 54% for Ziehl-Neelsen staining and culture, respectively), in the diagnosis of tuberculous meningitis in 91 patients in southeastern Brazil. Only three PCR-positive, microbiologically negative patients were found. Analysis of sequential cerebrospinal fluid samples by nested PCR detected Mycobacterium tuberculosis DNA up to 29 days after the introduction of antituberculosis chemotherapy.
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Affiliation(s)
- V M Brienze
- Departamento de Doenças Infecciosas e Parasitárias, Faculdade de Medicina de São José do Rio Preto, São José do Rio Preto, SP
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72
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Garcia L, Alonso-Sanz M, Rebollo MJ, Tercero JC, Chaves F. Mutations in the rpoB gene of rifampin-resistant Mycobacterium tuberculosis isolates in Spain and their rapid detection by PCR-enzyme-linked immunosorbent assay. J Clin Microbiol 2001; 39:1813-8. [PMID: 11325996 PMCID: PMC88031 DOI: 10.1128/jcm.39.5.1813-1818.2001] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Genetic alterations in the rpoB gene were characterized in 50 rifampin-resistant (Rif(r)) clinical isolates of Mycobacterium tuberculosis complex from Spain. A rapid PCR-enzyme-linked immunosorbent assay (ELISA) technique for the identification of rpoB mutations was evaluated with isolates of the M. tuberculosis complex and clinical specimens from tuberculosis patients that were positive for acid-fast bacilli (AFB). Sequence analysis demonstrated 11 different rpoB mutations among the Rif(r) isolates in the study. The most frequent mutations were those associated with codon 531 (24 of 50; 48%) and codon 526 (11 of 50; 22%). Although the PCR-ELISA does not permit characterization of the specific Rif(r) allele within each strain, 10 of the 11 Rif(r) genotypes were correctly identified by this method. We used the PCR-ELISA to predict the rifampin susceptibility of M. tuberculosis complex organisms from 30 AFB-positive sputum specimens. For 28 samples, of which 9 contained Rif(r) organisms and 19 contained susceptible strains, results were concordant with those based on culture-based drug susceptibility testing and sequencing. Results from the remaining two samples could not be interpreted because of low bacillary load (microscopy score of 1+ for 1 to 9 microorganisms/100 fields). Our results suggest that the PCR-ELISA is an easy technique to implement and could be used as a rapid procedure for detecting rifampin resistance to complement conventional culture-based methods.
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73
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Yu TW, Muller R, Muller M, Zhang X, Draeger G, Kim CG, Leistner E, Floss HG. Mutational analysis and reconstituted expression of the biosynthetic genes involved in the formation of 3-amino-5-hydroxybenzoic acid, the starter unit of rifamycin biosynthesis in amycolatopsis Mediterranei S699. J Biol Chem 2001; 276:12546-55. [PMID: 11278540 DOI: 10.1074/jbc.m009667200] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
To investigate a novel branch of the shikimate biosynthesis pathway operating in the formation of 3-amino-5-hydroxybenzoic acid (AHBA), the unique biosynthetic precursor of rifamycin and related ansamycins, a series of target-directed mutations and heterologous gene expressions were investigated in Amycolatopsis mediterranei and Streptomyces coelicolor. The genes involved in AHBA formation were inactivated individually, and the resulting mutants were further examined by incubating the cell-free extracts with known intermediates of the pathway and analyzing for AHBA formation. The rifL, -M, and -N genes were shown to be involved in the step(s) from either phosphoenolpyruvate/d-erythrose 4-phosphate or other precursors to 3,4-dideoxy-4-amino-d-arabino-heptulosonate 7-phosphate. The gene products of the rifH, -G, and -J genes resemble enzymes involved in the shikimate biosynthesis pathway (August, P. R., Tang, L., Yoon, Y. J., Ning, S., Müller, R., Yu, T.-W., Taylor, M., Hoffmann, D., Kim, C.-G., Zhang, X., Hutchinson, C. R., and Floss, H. G. (1998) Chem. Biol. 5, 69-79). Mutants of the rifH and -J genes produced rifamycin B at 1% and 10%, respectively, of the yields of the wild type; inactivation of the rifG gene did not affect rifamycin production significantly. Finally, coexpressing the rifG-N and -J genes in S. coelicolor YU105 under the control of the act promoter led to significant production of AHBA in the fermented cultures, confirming that seven of these genes are indeed necessary and sufficient for AHBA formation. The effects of deletion of individual genes from the heterologous expression cassette on AHBA formation duplicated the effects of the genomic rifG-N and -J mutations on rifamycin production, indicating that all these genes encode proteins with catalytic rather than regulatory functions in AHBA formation for rifamycin biosynthesis by A. mediterranei.
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Affiliation(s)
- T W Yu
- Department of Chemistry, University of Washington, Seattle, Washington 98195-1700, USA.
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74
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Strych U, Penland RL, Jimenez M, Krause KL, Benedik MJ. Characterization of the alanine racemases from two mycobacteria. FEMS Microbiol Lett 2001; 196:93-8. [PMID: 11267762 DOI: 10.1111/j.1574-6968.2001.tb10547.x] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
D-Alanine is a necessary precursor in the biosynthesis of the bacterial peptidoglycan. The naturally occurring L-alanine isomer is racemized to its D-form through the action of a class of enzymes called alanine racemases. These enzymes are ubiquitous among prokaryotes, and with very few exceptions are absent in eukaryotes, making them a logical target for the development of novel antibiotics. The alanine racemase gene from both Mycobacterium tuberculosis and M. avium was amplified by PCR and cloned in Escherichia coli. Overexpression of the proteins in the E. coli BL21 system, both as native and as His-tagged recombinant products, has been achieved. The proteins have been purified to electrophoretic homogeneity and analyzed biochemically. A D-alanine requiring double knock-out mutant of E. coli (alr, dadX) was constructed and the cloned genes were able to complement its deficiencies.
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Affiliation(s)
- U Strych
- Department of Biology and Biochemistry, University of Houston, Houston, TX 77204-5513, USA
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75
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Van Soolingen D. Molecular epidemiology of tuberculosis and other mycobacterial infections: main methodologies and achievements. J Intern Med 2001; 249:1-26. [PMID: 11168781 DOI: 10.1046/j.1365-2796.2001.00772.x] [Citation(s) in RCA: 203] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the last decade, DNA fingerprint techniques have become available to study the interperson transmission of tuberculosis and other mycobacterial infections. These methods have facilitated epidemiological studies at a population level. In addition, the species identification of rarely encountered mycobacteria has improved significantly. This article describes the state of the art of the main molecular typing methods for Mycobacterium tuberculosis complex and non-M. tuberculosis complex (atypical) mycobacteria. Important new insights that have been gained through molecular techniques into epidemiological aspects and diagnosis of mycobacterial diseases are highlighted.
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MESH Headings
- Animals
- Contact Tracing
- DNA Fingerprinting
- DNA, Bacterial/genetics
- Genetics, Microbial/trends
- Genotype
- Humans
- Molecular Epidemiology/methods
- Mycobacterium/classification
- Mycobacterium/genetics
- Mycobacterium/isolation & purification
- Mycobacterium Infections, Nontuberculous/epidemiology
- Mycobacterium Infections, Nontuberculous/genetics
- Mycobacterium Infections, Nontuberculous/transmission
- Mycobacterium tuberculosis/genetics
- Nontuberculous Mycobacteria/genetics
- Polymorphism, Restriction Fragment Length
- RNA, Bacterial/genetics
- Reproducibility of Results
- Sequence Analysis, DNA
- Sequence Analysis, RNA
- Transformation, Bacterial
- Tuberculosis/epidemiology
- Tuberculosis/genetics
- Tuberculosis/transmission
- Tuberculosis, Multidrug-Resistant/epidemiology
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Affiliation(s)
- D Van Soolingen
- Mycobacteria Reference Department, Diagnostic Laboratory for Infectious Diseases and Perinatal Screening, National Institute of Public Health and the Environment, Bilthoven, The Netherlands.
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76
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Sritharan M, Sritharan V. Polymerase chain reaction in the diagnosis of tuberculosis. Indian J Clin Biochem 2000; 15:200-16. [PMID: 23105283 PMCID: PMC3454082 DOI: 10.1007/bf02867559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
A rapid, sensitive, specific and yet economical method for the diagnosis ofM. tuberculosis and other mycobacteria in clinical specimen is a desperate and urgent requirement of the day in the laboratory diagnosis and hence management of tuberculosis. This need is further accentuated by emerging diseases like multi drug resistant tuberculosis, tuberculosis in AIDS patients and opportunistic mycobacterial infections, which do not respond to conventional anti TB therapy. Molecular methods, particularly PCR based detection ofM. tuberculosis, has come a long way since it was first described about fifteen years ago. Several probes have been developed and some of them, particularly the IS6110 and TB400 have been validated on several clinical samples. The latter has been validated on a variety of clinical specimens along with a simple sample processing method. Polymerase chain reaction based diagnosis ofM. tuberculosis has been introduced as one of the routine/confirmatory tests in clinical microbiology laboratory in some countries like Canada, the United States and the United Kingdom several years ago. The possibility of introducing PCR based direct diagnosis of drug resistance is being explored in some laboratories, particularly for drugs like rifampicin. The evolution and application of PCR for diagnosis ofM. tuberculosis is being analysed and discussed in this review.
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Affiliation(s)
- Manjula Sritharan
- Department of Animal Sciences, School of Life Sciences, University of Hyderabad, 46 Hyderabad
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77
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Murali Krishna PS, Venkateswarlu G, Venkateswar Rao L. Effect of uracil on rifamycin SV production by Amycolatopsis mediterranei MV35R. Lett Appl Microbiol 2000; 31:73-6. [PMID: 10886619 DOI: 10.1046/j.1472-765x.2000.00769.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The effect of different organic nitrogen compounds on the production of rifamycin SV by Amycolatopsis mediterranei MV35R and their optimum concentrations have been described. Results obtained indicate that rifamycin SV production increased from 4020 mg l-1 to 4575 mg l-1 when organic nitrogen compound uracil was added at 0.2% (w/v) concentration to the fermentation medium by A. mediterranei MV35R. The rifamycin SV yield was enhanced by 505 mg l-1 using uracil (2 g l-1) when compared with barbital.
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78
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Identification of drug-resistantMycobacterium tuberculosis by single strand conformation polymorphism and cleavase fragment length polymorphism. Indian J Clin Biochem 2000; 15:88-93. [DOI: 10.1007/bf02883734] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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79
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Hannan MM, Azadian BS, Gazzard BG, Hawkins DA, Hoffman PN. Hospital infection control in an era of HIV infection and multi-drug resistant tuberculosis. J Hosp Infect 2000; 44:5-11. [PMID: 10633047 DOI: 10.1053/jhin.1999.0651] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Tuberculosis infection control in hospitals has received renewed interest after decades of low prominence following the occurrence of multiply drug-resistant strains in populations of patients with immune systems affected by HIV. This paper examines the history of tuberculosis infection control in hospitals and how recent outbreaks have influenced contemporary measures. The principal infection control measure must always be early recognition and isolation of patients in HIV-care situations who may be dispersing Mycobacterium tuberculosis, in both ward and outpatient areas. If there is either a high degree of suspicion or proven TB, patients should be housed in negative pressure isolation rooms whilst undergoing treatment and investigation. Procedures which may generate infectious aerosols should be carried out in similarly ventilated rooms. The quality assurance in such infection control is through the administrative systems put in place, staff training and the engineering controls of isolation room ventilation.
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Affiliation(s)
- M M Hannan
- Medical Microbiology Department, Department of HIV/GUM, Chelsea and Westminster Hospital, 369 Fulham Rd, SW10 9NH, UK
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80
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Abstract
The most frequent cause of upper urinary tract infection remains E. coli. Other organisms are found in complicated infections associated with diabetes mellitus, instrumentation, stone, and immunosuppression. The pathogenesis of acute pyelonephritis is reviewed herein, with an emphasis on the virulence factors responsible for its initiation, including urothelial adhesion by P-fimbriae of E. coli and other common factors including hemolysin and aerobactin. Renal damage does not always ensue following such infection. It is seen when toxic oxygen radicals are released during the ischemic episode and the respiratory burst of phagocytosis is marked and prolonged. These events occur when effective antibacterial treatment is delayed when the diagnosis is not made early or when socioeconomic factors prevent treatment. The scarring of chronic pyelonephritis leads to the loss of renal tissue and function and may progress to end-stage renal disease. With effective antibacterial therapy, the immune response by both T and B lymphocytes leads to antibodies that assist in bacterial eradication. Therapy must be both rapid and effective. In many instances, antibacterial agents may be used as outpatient therapy. If the Gram stain shows only gram-negative organisms and if the infection is community acquired, oral outpatient therapy with trimethoprim/sulfamethoxazole or a fluoroquinolone may suffice if the patient has no nausea. When the patient is septic, hospitalization and treatment with parenteral antibiotics are needed. Both ceftriaxone and gentamycin are cost-effective parenteral therapy because only once-daily dosing is needed. If gram-positive organisms are found, an enterococcus should be suspected, and a beta-lactam penicillin such as piperacillin or a third-generation cephalosporin such as ceftriaxone is indicated. If penicillin allergy exists, vancomycin should be used. If the patient does not improve rapidly, diagnostic studies including ultrasound and CT will assist in the diagnosis of obstruction, abscess, or emphysematous pyelonephritis. Most of these complications are now rapidly treated percutaneously, with surgical therapy following as needed. Complicated infections, such as those occurring in patients with anatomic abnormalities, stone, or immunosuppression, are often caused by organisms other than E. coli, and long-term antibacterial therapy often leads to fungal infections such as candidiasis. A recrudescence of tuberculosis is occurring, often with resistance to antituberculous drugs. The increased incidence has been associated with the immunosuppression of AIDS but is also occurring in intravenous drug users, perhaps because of poor nutrition but also owing to noncompliance with treatment. The symptoms of renal tuberculosis are usually limited to fever, frequency, urgency, and dysuria. Hematuria with sterile pyuria is the usual laboratory finding. The young urologist should remember this renal disease in the differential diagnosis of hematuria, because medical therapy can provide a cure.
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Affiliation(s)
- J A Roberts
- Department of Urology, Tulane University School of Medicine, New Orleans, Louisiana, USA
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81
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Abstract
There is currently intense interest in unravelling the modus operandi of type I modular polyketide synthases in order to lay the ground work for their use in the combinatorial biosynthesis of new bioactive molecules. Much of our knowledge is derived from studies on 6-deoxyerythronolide B (DEBS), the enzyme assembling the polyketide backbone of erythromycin. Work on the rifamycin polyketide synthase has revealed a number of features that differ from those seen with DEBS.
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Affiliation(s)
- H G Floss
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA.
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82
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Naser SA, Felix J, Liping H, Romero C, Naser N, Walsh A, Safranek W. Occurrence of the IS900 gene in Mycobacterium avium complex derived from HIV patients. Mol Cell Probes 1999; 13:367-72. [PMID: 10508558 DOI: 10.1006/mcpr.1999.0261] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The occurrence of the insertion sequence IS900 in Mycobacterium avium subsp. avium strains isolated from HIV infected patients has been investigated. In this study, genomic DNA from 62 mycobacterial isolates [31 strains of M. avium complex (MAC) consisting of 26 M. avium subsp. avium HIV-isolates and five non-HIV isolates and 31 additional Mycobacterium species] were analysed by an IS900 -based polymerase chain reaction (PCR) assay and Southern hybridization using a non-radioactive-labelled 251 bp DNA fragment located at the 5'-region of the IS900 sequence. As expected, none of the 28 Mycobacterium species contained the IS900 in their genomic DNA. Of the 26 M. avium subsp. avium HIV-isolates, 15 (57.6%) were strongly positive for the IS900 or IS900 related sequence. The five pulmonary non-HIV MAC isolates were negative for the IS900. As expected, the three strains of M. avium subsp. paratuberculosis were positive. This PCR guided study suggest that the IS900 gene is very common in clinical strains of M. avium subsp. avium especially those isolated from HIV patients. Ultimately the IS900 PCR-based assay may provide a useful tool for diagnostic and epidemiological studies related to MAC infections in HIV patients.
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Affiliation(s)
- S A Naser
- Department of Molecular Biology and Microbiology and Center for Discovery of Drugs and Diagnostics, University of Central Florida, Orlando, Florida 32816, USA.
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83
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Yu TW, Shen Y, Doi-Katayama Y, Tang L, Park C, Moore BS, Richard Hutchinson C, Floss HG. Direct evidence that the rifamycin polyketide synthase assembles polyketide chains processively. Proc Natl Acad Sci U S A 1999; 96:9051-6. [PMID: 10430893 PMCID: PMC17730 DOI: 10.1073/pnas.96.16.9051] [Citation(s) in RCA: 110] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The assembly of the polyketide backbone of rifamycin B on the type I rifamycin polyketide synthase (PKS), encoded by the rifA-rifE genes, is terminated by the product of the rifF gene, an amide synthase that releases the completed undecaketide as its macrocyclic lactam. Inactivation of rifF gives a rifamycin B nonproducing mutant that still accumulates a series of linear polyketides ranging from the tetra- to a decaketide, also detected in the wild type, demonstrating that the PKS operates in a processive manner. Disruptions of the rifD module 8 and rifE module 9 and module 10 genes also result in accumulation of such linear polyketides as a consequence of premature termination of polyketide assembly. Whereas the tetraketide carries an unmodified aromatic chromophore, the penta- through decaketides have undergone oxidative cyclization to the naphthoquinone, suggesting that this modification occurs during, not after, PKS assembly. The structure of one of the accumulated compounds together with (18)O experiments suggests that this oxidative cyclization produces an 8-hydroxy-7, 8-dihydronaphthoquinone structure that, after the stage of proansamycin X, is dehydrogenated to an 8-hydroxynaphthoquinone.
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Affiliation(s)
- T W Yu
- Department of Chemistry, Box 351700, University of Washington, Seattle, WA 98195-1700, USA
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84
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Eads JC, Beeby M, Scapin G, Yu TW, Floss HG. Crystal structure of 3-amino-5-hydroxybenzoic acid (AHBA) synthase. Biochemistry 1999; 38:9840-9. [PMID: 10433690 DOI: 10.1021/bi990018q] [Citation(s) in RCA: 40] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The biosynthesis of ansamycin antibiotics, including rifamycin B, involves the synthesis of an aromatic precursor, 3-amino-5-hydroxybenzoic acid (AHBA), which serves as starter for the assembly of the antibiotics' polyketide backbone. The terminal enzyme of AHBA formation, AHBA synthase, is a dimeric, pyridoxal 5'-phosphate (PLP) dependent enzyme with pronounced sequence homology to a number of PLP enzymes involved in the biosynthesis of antibiotic sugar moieties. The structure of AHBA synthase from Amycolatopsis mediterranei has been determined to 2.0 A resolution, with bound cofactor, PLP, and in a complex with PLP and an inhibitor (gabaculine). The overall fold of AHBA synthase is similar to that of the aspartate aminotransferase family of PLP-dependent enzymes, with a large domain containing a seven-stranded beta-sheet surrounded by alpha-helices and a smaller domain consisting of a four-stranded antiparallel beta-sheet and four alpha-helices. The uninhibited form of the enzyme shows the cofactor covalently linked to Lys188 in an internal aldimine linkage. On binding the inhibitor, gabaculine, the internal aldimine linkage is broken, and a covalent bond is observed between the cofactor and inhibitor. The active site is composed of residues from two subunits of AHBA synthase, indicating that AHBA synthase is active as a dimer.
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Affiliation(s)
- J C Eads
- School of Biochemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT, U.K
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85
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Sintchenko V, Chew WK, Jelfs PJ, Gilbert GL. Mutations in rpoB gene and rifabutin susceptibility of multidrug-resistant Mycobacterium tuberculosis strains isolated in Australia. Pathology 1999; 31:257-60. [PMID: 10503273 DOI: 10.1080/003130299105089] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/16/2022]
Abstract
Control of tuberculosis, the single largest killer among the infectious diseases, has been threatened by the emergence of multidrug-resistant Mycobacterium tuberculosis (MDRTB) infection due to the limited treatment options. Rifampicin (RIF) resistance is considered as a marker for MDRTB. The aim of this study was the detection of rpoB gene mutations and rifabutin resistance in MDRTB strains recently isolated in Australia by a line probe assay (INNO-LiPA Rif. TB, Innogenetics). Rifabutin and RIF susceptibility of 20 MDRTB and 16 RIF-sensitive M. tuberculosis complex clinical isolates were studied. The overall concordance of the line probe assay (LiPA) with phenotypic RIF susceptibility test was 96%. Seven distinct nucleotide substitutions were identified in 21 of 22 RIF-resistant isolates of diverse geographical origins, but in none of the RIF-sensitive strains. The majority (71%) of mutations occurred in the 526-533 codons and were associated with resistance to rifabutin and RIF. Of the RIF-resistant MDRTB strains, 18% appeared to be rifabutin-sensitive and produced delta S2 and delta S3 INNO-LiPA patterns. We conclude that amino acid substitutions at Asp516 and Ser522 in the rpoB gene in RIF-resistant M. tuberculosis predict rifabutin susceptibility for MDRTB. Use of the LiPA for RIF and rifabutin resistance may facilitate the rapid response required to limit the extent and severity of MDRTB transmission and infection.
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Affiliation(s)
- V Sintchenko
- Centre for Infectious Diseases, Westmead Hospital, New South Wales, Australia.
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86
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Adams LB, Sinha I, Franzblau SG, Krahenbuhl JL, Mehta RT. Effective treatment of acute and chronic murine tuberculosis with liposome-encapsulated clofazimine. Antimicrob Agents Chemother 1999; 43:1638-43. [PMID: 10390215 PMCID: PMC89336 DOI: 10.1128/aac.43.7.1638] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The therapeutic efficacy of liposomal clofazimine (L-CLF) was studied in mice infected with Mycobacterium tuberculosis Erdman. Groups of mice were treated with either free clofazimine (F-CLF), L-CLF, or empty liposomes twice a week for five treatments beginning on day 1 (acute), day 21 (established), or day 90 (chronic) postinfection. One day after the last treatment, the numbers of CFU of M. tuberculosis in the spleen, liver, and lungs were determined. F-CLF at the maximum tolerated dose of 5 mg/kg of body weight was ineffective; however, 10-fold-higher doses of L-CLF demonstrated a dose response with significant CFU reduction in all tissues without any toxic effects. In acutely infected mice, 50 mg of L-CLF/kg reduced CFU 2 to 3 log units in all three organs. In established or chronic infection, treated mice showed no detectable CFU in the spleen or liver and 1- to 2-log-unit reduction in the lungs. A second series of L-CLF treatments cleared M. tuberculosis in all three tissues. L-CLF appears to be bactericidal in the liver and spleen, which remained negative for M. tuberculosis growth for 2 months. Thus, L-CLF could be useful in the treatment of tuberculosis.
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Affiliation(s)
- L B Adams
- G. W. Long Hansen's Disease Center at Louisiana State University, Baton Rouge, Louisiana, USA
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87
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Munsiff SS, Alpert PL, Gourevitch MN, Chang CJ, Klein RS. A prospective study of tuberculosis and HIV disease progression. JOURNAL OF ACQUIRED IMMUNE DEFICIENCY SYNDROMES AND HUMAN RETROVIROLOGY : OFFICIAL PUBLICATION OF THE INTERNATIONAL RETROVIROLOGY ASSOCIATION 1998; 19:361-6. [PMID: 9833744 DOI: 10.1097/00042560-199812010-00006] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To determine whether active tuberculosis alters the rate of progression of HIV infection in dually infected patients. METHODS HIV-seropositive patients at two Bronx, New York hospitals with tuberculosis confirmed by culture from July 1992 to February 1995, who survived the initial hospitalization for tuberculosis, were matched on gender, age, CD4+ percentage, and calendar time with HIV-seropositive patients without tuberculosis participating in a study of the natural history of HIV infection. Patients received follow-up observation prospectively until May 23, 1995 to determine survival rates and development of AIDS-defining opportunistic infections (OIs). RESULTS 70 patients had tuberculosis; 120 did not. Mean CD4+ percentages were 12.4% and 12.5%, respectively. At study entry, 27% of those with tuberculosis had prior AIDS-defining OIs other than tuberculosis, compared with 10% of those without tuberculosis (p = .004). In multivariate survival analysis, controlling for CD4+ level, tuberculosis was not an independent predictor of increased other causes of AIDS-related mortality. However, in a logistic regression model, independent predictors of subsequent OIs included tuberculosis (hazard ratio, 4.1; 95% confidence intervals [CI], 1.9, 8.7), CD4+ count <100/mm3 (hazard ratio, 2.4; 95% CI, 1.1, 5.0) and prior OIs (hazard ration, 3.3; 95% CI, 1.3, 8.3). CONCLUSIONS Tuberculosis was not an independent predictor of increased non-tuberculosis-related mortality in HIV-seropositive patients but was associated with increased risk of development of OIs.
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Affiliation(s)
- S S Munsiff
- Department of Medicine, Montefiore Medical Center and the Albert Einstein College of Medicine, Bronx, New York, USA.
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88
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Zanini MS, Moreira EC, Lopes MT, Mota P, Salas CE. Detection of Mycobacterium bovis in milk by polymerase chain reaction. ZENTRALBLATT FUR VETERINARMEDIZIN. REIHE B. JOURNAL OF VETERINARY MEDICINE. SERIES B 1998; 45:473-9. [PMID: 9820115 DOI: 10.1111/j.1439-0450.1998.tb00818.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
A simple method was developed for DNA extraction of Mycobacterium bovis in milk and further detection of the bacterium by polymerase chain reaction (PCR). Milk previously seeded with M. bovis was used as the starting material. The procedure involved overnight digestion of a milk sample with proteinase K at 56 degrees C and phenol extraction, followed by ethanol precipitation and PCR. The amplification pattern obtained was analyzed with primers BW8-BW9 which amplify a 248 bp in strains of M. bovis. By using the BW8-BW9 primers, 10(3) CFU were detected on silver-stained PAGE gels. The procedure was validated by PCR analysis of milk in tuberculin-positive animals. It is anticipated that this method can be used for routine diagnosis of M. bovis in milk samples.
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Affiliation(s)
- M S Zanini
- Departamento de Bioquímica e Imunologia, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
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89
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Doenhoff MJ. Granulomatous inflammation and the transmission of infection: schistosomiasis--and TB too? IMMUNOLOGY TODAY 1998; 19:462-7. [PMID: 9785670 DOI: 10.1016/s0167-5699(98)01310-3] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Immune-dependent granulomatous inflammation is important in the pathogenesis of both schistosomiasis and tuberculosis. A case has previously been made for a role for schistosome egg-induced granulomas in the onward transmission of infection. Here, Mike Doenhoff suggests that a similar hypothesis applies to tuberculosis.
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Affiliation(s)
- M J Doenhoff
- School of Biological Sciences, University of Wales, Bangor, Gwynedd, UK.
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90
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Cantrell CL, Nuñez IS, Castañeda-Acosta J, Foroozesh M, Fronczek FR, Fischer NH, Franzblau SG. Antimycobacterial activities of dehydrocostus lactone and its oxidation products. JOURNAL OF NATURAL PRODUCTS 1998; 61:1181-1186. [PMID: 9784148 DOI: 10.1021/np970333i] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
In an attempt to study the structural dependence of antimycobacterial activity of the guaianolide dehydrocostus lactone and its derivatives, m-chloroperoxybenzoic acid oxidations of dehydrocostus lactone (1a) were performed. Three new monoepoxides, one previously synthesized diepoxide, and two new diepoxides were obtained. Two of the monoepoxides are C-10 epimers (3a, 3b), while the 4(15)-monoepoxide (2) has the 4alpha-O-configuration. The known diepoxide (4a) contains a C-10 alpha-epoxide and a beta-epoxide at C-4. The diepoxides 4b and 4c, each with a C-4 alpha-epoxy group, differ in the configuration of the epoxide ring at C-10. Allylic oxidation of dehydrocostus lactone (1a) with selenium dioxide/tert-butyl hydroperoxide afforded the known 3-epizaluzanin C (1b). The relative configurations of compounds 1b-4c were established by 1D and 2D NMR techniques (1H, 13C, COSY, NOESY, HMQC, and HMBC) as well as comparison with literature data. The molecular structures of lactones 1b, 4a, and 4c were determined by single-crystal X-ray diffraction. In radiorespirometric bioassays against Mycobacterium tuberculosis and Mycobacterium avium, dehydrocostus lactone (1a) exhibited minimum inhibitory concentrations of 2 and 16 microgram/mL, respectively. In contrast, its monoepoxides (2, 3a, and 3b) and diepoxides (4a-c), as well as its hydrogenated derivatives and other analogues (1b, 1c, 5, and 6), showed significantly lower activities against M. tuberculosis.
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Affiliation(s)
- C L Cantrell
- Department of Chemistry, Louisiana State University, Baton Rouge, Louisiana 70803-1804, and G. W. L. Hansen's Disease Center, P.O. Box 25072, Baton Rouge, Louisiana 70894, USA
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91
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Oleksijew A, Meulbroek J, Ewing P, Jarvis K, Mitten M, Paige L, Tovcimak A, Nukkula M, Chu D, Alder JD. In vivo efficacy of ABT-255 against drug-sensitive and -resistant Mycobacterium tuberculosis strains. Antimicrob Agents Chemother 1998; 42:2674-7. [PMID: 9756775 PMCID: PMC105917 DOI: 10.1128/aac.42.10.2674] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Current therapy for pulmonary tuberculosis involves 6 months of treatment with isoniazid, pyrazinamide, rifampin, and ethambutol or streptomycin for reliable treatment efficacy. The long treatment period increases the probability of noncompliance, leading to the generation of multidrug-resistant isolates of Mycobacterium tuberculosis. A treatment option that significantly shortened the course of therapy, or a new class of antibacterial effective against drug-resistant M. tuberculosis would be of value. ABT-255 is a novel 2-pyridone antibacterial agent which demonstrates in vitro potency and in vivo efficacy against drug-susceptible and drug-resistant M. tuberculosis strains. By the Alamar blue reduction technique, the MIC of ABT-255 against susceptible strains of M. tuberculosis ranged from 0.016 to 0.031 microg/ml. The MIC of ABT-255 against rifampin- or ethambutol-resistant M. tuberculosis isolates was 0.031 microg/ml. In a murine model of pulmonary tuberculosis, 4 weeks of oral ABT-255 therapy produced a 2- to 5-log10 reduction in viable drug-susceptible M. tuberculosis counts from lung tissue. Against drug-resistant strains of M. tuberculosis, ABT-255 produced a 2- to 3-log10 reduction in viable bacterial counts from lung tissue. ABT-255 is a promising new antibacterial agent with activity against M. tuberculosis.
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Affiliation(s)
- A Oleksijew
- Experimental Therapeutics and Pharmacology, Abbott Laboratories, Abbott Park, Illinois 60064, USA.
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92
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van der Zanden AG, Hoentjen AH, Heilmann FG, Weltevreden EF, Schouls LM, van Embden JD. Simultaneous detection and strain differentiation of Mycobacterium tuberculosis complex in paraffin wax embedded tissues and in stained microscopic preparations. Mol Pathol 1998; 51:209-14. [PMID: 9893747 PMCID: PMC395638 DOI: 10.1136/mp.51.4.209] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
AIMS To detect and differentiate Mycobacterium tuberculosis simultaneously by polymerase chain reaction (PCR) in clinical samples prepared for histopathological analysis and for microscopic detection of acid fast bacteria. METHODS Paraffin wax embedded tissue samples and Ziehl-Neelsen (ZN) and auramine stained microscopic preparations from culture positive tuberculosis patients were subjected to DNA extraction and amplification by PCR. PCR was performed with primers specific for direct repeats and the product was detected by hybridisation to a set of 43 different oligonucleotides, a procedure designated as "spoligotyping". RESULTS Mycobacterium tuberculosis complex DNA was detected in all of the 23 paraffin wax embedded tissues analysed. Strain differentiation was possible in 20 of the 23 paraffin wax embedded tissues. Mycobacterium tuberculosis complex DNA was also detected and typed in eight of 10 ZN stained microscopic preparations. The hybridisation patterns obtained from virtually all of these samples were identical to those obtained from DNA extracted from cultures. CONCLUSION Simultaneous detection and strain differentiation of M. tuberculosis complex bacteria is possible in clinical samples prepared by current methods for microscopic and histopathological analysis, without the need to culture. The methodology described opens the way to rapid disclosure of outbreaks in high risk settings, such as hospitals and prisons, where dissemination of tuberculosis might be very fast as a result of a high prevalence of human immunodeficiency virus infected patients.
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93
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Abstract
Compromised travelers represent a diverse and challenging group of individuals. They include HIV-infected patients who are at risk for potentially adverse reactions to immunizations, and new exposures to enteric water-borne opportunistic pathogens associated with chronic infections. Such travelers may encounter unfamiliar opportunistic fungi and classical tropical infections, such as leishmaniasis, whose pathogenesis can be enhanced by the presence of prior HIV infection. Other immunocompromised groups include those who are functionally or anatomically asplenic, and patients who are iatrogenically immunosuppressed from medications utilized for solid organ transplantation, chemotherapy, or treatment of malignancies. This population of travelers also includes those with diabetes mellitus who may require adjustments in their dosing, administration, and possibly even the types of insulin used on their trips. These patients are also at greater risk for acquisition of tuberculosis, severe community-acquired pneumonia, urinary tract infections, and pyomyositis. Older travelers present both the infectious disease and travel medicine specialist with issues such events, malignancy-related infections, myocardial infarction, and other forms of cardiopulmonary compromise, which the authors address in this article.
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Affiliation(s)
- M D Mileno
- Department of Medicine, Brown University, Providence, Rhode Island, USA
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94
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Abstract
Given the multiple impairments in host defense that occur during HIV infection, patients with AIDS are at risk for a variety of pleural infections and neoplasms. Of infectious causes, bacterial parapneumonic effusions and empyemas and tuberculous pleurisy occur more frequently than effusions caused by P. carinii. In each case, therapy is directed at eradication of the causative organisms. In the setting of systemic Kaposi's sarcoma, pleural involvement is common, although diagnosis is difficult and therapeutic options are limited. Pleural effusions caused by non-Hodgkin's lymphoma often occur in the setting of pulmonary parenchymal disease and can be diagnosed cytologically. The recently described entity of primary effusion lymphoma occurs in the absence of solid-organ involvement. The development of a spontaneous pneumothorax in a HIV-infected individual should prompt a search for P. carinii infection. Although these pneumothoraces often recur and are difficult to manage, recent series suggest that surgical approaches to bronchopleural fistulas are reasonable in selected patients.
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Affiliation(s)
- J M Beck
- Department of Internal Medicine, University of Michigan Medical School, Ann Arbor, USA
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95
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Messmer PR, Jones S, Moore J, Taggart B, Parchment Y, Holloman F, Quintero LM. Knowledge, Perceptions, and Practice of Nurses Toward HIV+/AIDS Patients Diagnosed With Tuberculosis. J Contin Educ Nurs 1998; 29:117-25. [PMID: 9652265 DOI: 10.3928/0022-0124-19980501-07] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Tuberculosis (TB) continues to be a major health problem in the United States. Nurses may be exposed to TB and not realize their risks for becoming infected. The presentation of HIV-associated TB is somewhat different from "standard TB." PURPOSE The purpose of this study was to determine if an educational program could improve nurses' attitudes, level of knowledge, and compliance with infection control standards for HIV/AIDS patients diagnosed with TB. METHOD Participants included 50 staff nurses. The experimental group (35) and control group (15) completed a knowledge test and an attitude survey. Researchers observed participants for compliance with infection control standards pretest and posttest. RESULTS Following an educational program, the experimental group demonstrated a greater knowledge of TB than the control group who did not participate in the educational program (F [1.47] = 14.43, p = .000). In addition, the experimental group had a greater improvement in their Nursing Intervention Observation Tool adherence to respiratory isolation and universal precaution protocols scores as compared to the control group (F [1.47] = 8.95, p = .004). However, there was not a tangible increase in knowledge level of AIDS, attitudes or concerns about caring for these patients. CONCLUSION This nursing research study supports the need for an ongoing educational program with continual monitoring of infection control practices to positively affect client and caregiver outcomes.
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Affiliation(s)
- P R Messmer
- Mount Sinai Medical Center, Miami Beach, FL 33140, USA
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96
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Abstract
This review on the effects of opiate use on infectious diseases discusses the complete spectrum of infections in the opiate user, including those of the lung, the GI tract, the skin, the skeletal system, and the CNS. There is both increased prevalence and increased severity of bacterial and viral infections in injection drug users with the outcome of increased morbidity and mortality. The experimental administration of opiates has lead to a greater understanding of the effects on susceptibility to and progression of infectious diseases. Animal models of opiate dependence and infection are reviewed with specific attention to cases in which the opiate-mediated effects are harmful and in which cases they are beneficial.
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Affiliation(s)
- J M Risdahl
- University of Minnesota, Department of Clinical and Population Sciences, Veterinary Teaching Hospital, St. Paul 55108, USA
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97
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Fattorini L, Xiao Y, Mattei M, Li Y, Iona E, Ricci ML, Thoresen OF, Creti R, Orefici G. Activities of isoniazid alone and in combination with other drugs against Mycobacterium avium infection in beige mice. Antimicrob Agents Chemother 1998; 42:712-4. [PMID: 9517960 PMCID: PMC105526 DOI: 10.1128/aac.42.3.712] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Monotherapy with isoniazid or amikacin or clarithromycin or combinations of two of these drugs showed nil to modest therapeutic activity in beige mice infected with Mycobacterium avium. However, the combination of all three, isoniazid-amikacin-clarithromycin, markedly reduced CFUs in both spleens and lungs after 91 days of infection.
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Affiliation(s)
- L Fattorini
- Laboratory of Bacteriology and Medical Mycology, Istituto Superiore di Sanità, Rome, Italy
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98
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August PR, Tang L, Yoon YJ, Ning S, Müller R, Yu TW, Taylor M, Hoffmann D, Kim CG, Zhang X, Hutchinson CR, Floss HG. Biosynthesis of the ansamycin antibiotic rifamycin: deductions from the molecular analysis of the rif biosynthetic gene cluster of Amycolatopsis mediterranei S699. CHEMISTRY & BIOLOGY 1998; 5:69-79. [PMID: 9512878 DOI: 10.1016/s1074-5521(98)90141-7] [Citation(s) in RCA: 266] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
BACKGROUND The ansamycin class of antibiotics are produced by various Actinomycetes. Their carbon framework arises from the polyketide pathway via a polyketide synthase (PKS) that uses an unusual starter unit. Rifamycin (rif), produced by Amycolatopsis mediterranei, is the archetype ansamycin and it is medically important. Although its basic precursors (3-amino-5-hydroxy benzoic acid AHBA, and acetic and propionic acids) had been established, and several biosynthetic intermediates had been identified, very little was known about the origin of AHBA nor had the PKS and the various genes and enzymes that modify the initial intermediate been characterized. RESULTS A set of 34 genes clustered around the rifK gene encoding AHBA synthase were defined by sequencing all but 5 kilobases (kb) of a 95 kb contiguous region of DNA from A. mediterranei. The involvement of some of the genes in the biosynthesis of rifamycin B was examined. At least five genes were shown to be essential for the synthesis of AHBA, five genes were determined to encode the modular type I PKS that uses AHBA as the starter unit, and 20 or more genes appear to govern modification of the polyketide-derived framework, and rifamycin resistance and export. Putative regulatory genes were also identified. Disruption of the PKS genes at the end of rifA abolished rifamycin B production and resulted in the formation of P8/1-OG, a known shunt product of rifamycin biosynthesis, whereas disruption of the orf6 and orf9 genes, which may encode deoxysugar biosynthesis enzymes, had no apparent effect. CONCLUSIONS Rifamycin production in A. mediterranei is governed by a single gene cluster consisting of structural, resistance and export, and regulatory genes. The genes characterized here could be modified to produce novel forms of the rifamycins that may be effective against rifamycin-resistant microorganisms.
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Affiliation(s)
- P R August
- Department of Chemistry, University of Washington, Seattle 98195-1700, USA
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99
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Herwaldt LA, Pottinger JM, Carter CD, Barr BA, Miller ED. Exposure Workups. Infect Control Hosp Epidemiol 1997. [DOI: 10.2307/30141343] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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100
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Abstract
AbstractExposure workups are an important responsibility for infection control personnel. A well-designed plan for investigating exposures, which includes appropriate algorithms, will enable infection control personnel to evaluate exposures rapidly and consistently so that nosocomial transmission is minimized. Infection control personnel should use their own data to develop policies and procedures that suit the needs of their facility. After they have imple-merited the plan, infection control personnel should continue to collect data on exposures so they can continuously improve their performance.
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