Inhibition of inducible nitric oxide synthase protects against liver injury induced by mycobacterial infection and endotoxins.

BACKGROUND/AIMS: Bacillus Calmette Guerin (BCG) infection causes hepatic injury following granuloma formation and secretion of cytokines which render mice highly sensitive to endotoxin-mediated hepatotoxicity. This work investigates the role of inducible nitric oxide synthase (iNOS) in liver damage induced by BCG and endotoxins in BCG-infected mice. METHODS: Liver injury and cytokine activation induced by BCG and by LPS upon BCG infection (BCG/LPS) were compared in wild-type and iNOS-/- mice. RESULTS: iNOS-/- mice infected with living BCG are protected from hepatic injury when compared to wild-type mice which express iNOS protein in macrophages forming hepatic granulomas. In addition, iNOS-/- mice show a decrease in BCG-induced IFN-gamma serum levels. LPS challenge in BCG-infected mice strongly activates iNOS in the liver and spleen of wild-type mice which show important liver damage associated with a dramatic increase in TNF and IL-6 and also Th1 type cytokines. In contrast, iNOS-/- mice are protected from liver injury after BCG/LPS challenge and their TNF, IL-6 and Th1 type cytokine serum levels raise moderately. CONCLUSIONS: These results demonstrate that nitric oxide (NO) from iNOS is involved in hepatotoxicity induced by both mycobacterial infection and endotoxin effects upon BCG infection and that inhibition of NO from iNOS protects from liver injuries.

QuantiFERON-TB Gold assay for the diagnosis of latent tuberculosis infection.

Tuberculin skin test (TST) has been used for 100 years for the diagnosis of latent tuberculosis (TB) infection (LTBI). In recent years, increasing interest in the diagnosis of TB has led to the development of new assays. QuantiFERON-TB Gold (QFT-G) is an IFN-gamma-release assay that measures the release of interferon after stimulation in vitro by Mycobacterium tuberculosis antigens. The main advantage of this assay with respect to TST is the lack of crossreaction with bacillus Calmette-Guérin and most nontuberculous mycobacteria. QFT-G also eliminates the need for the patient to return for test reading in 48-72 h. In the immunocompromised host and in pediatric populations, studies suggest that the QFT-G better correlates with the risk of TB than the TST, but data remain inconclusive. In contrast to TST, there are no prospective studies regarding the association of the QFT-G result and the risk for development of TB. Given its advantages, the QFT-G may become the standard test for the diagnosis of LTBI.

Clinical spectrum of tuberculous optic neuropathy.

PURPOSE: Tuberculous optic neuropathy may follow infection with Mycobacterium tuberculosis or administration of the bacille Calmette-Guerin. However, this condition is not well described in the ophthalmic literature. METHODS: Ophthalmologists, identified through professional electronic networks or previous publications, collected standardized clinical data relating to 62 eyes of 49 patients who they had managed with tuberculous optic neuropathy. RESULTS: Tuberculous optic neuropathy was most commonly manifested as papillitis (51.6 %), neuroretinitis (14.5 %), and optic nerve tubercle (11.3 %). Uveitis was an additional ocular morbidity in 88.7 % of eyes. In 36.7 % of patients, extraocular tuberculosis was present. The majority of patients (69.4 %) had resided in and/or traveled to an endemic area. Although initial visual acuity was 20/50 or worse in 62.9 % of 62 eyes, 76.7 % of 60 eyes followed for a median of 12 months achieved visual acuities of 20/40 or better. Visual field defects were reported for 46.8 % of eyes, but these defects recovered in 63.2 % of 19 eyes with follow-up. CONCLUSION: Visual recovery from tuberculous optic neuropathy is common, if the diagnosis is recognized and appropriate treatment is instituted. A tuberculous etiology should be considered when evaluating optic neuropathy in persons from endemic areas.

Lepromatous leprosy: a review and case report

Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae (Hansen"s bacillus). It is transmitted from person to person and has a long incubation period (between two and six years). The disease presents polar clinical forms (the"multibacillary" lepromatous leprosy and the"paucibacillary" tuberculoid leprosy), as well as other intermediate forms with hybrid characteristics. Oral manifestations usually appear in lepromatous leprosy and occur in 20-60% of cases. They may take the form of multiple nodules (lepromas) that progress to necrosis and ulceration. The ulcers are slow to heal, and produce atrophic scarring or even tissue destruction. The lesions are usually located on the hard and soft palate, in the uvula, on the underside of the tongue, and on the lips and gums. There may also be destruction of the anterior maxilla and loss of teeth. The diagnosis, based on clinical suspicion, is confirmed through bacteriological and histopathological analyses, as well as by means of the lepromin test (intradermal reaction that is usually negative in lepromatous leprosy form and positive in the tuberculoid form). The differential diagnosis includes systemic lupus erythematosus, sarcoidosis, cutaneous leishmaniasis and other skin diseases, tertiary syphilis, lymphomas, systemic mycosis, traumatic lesions and malignant neoplasias, among other disorders. Treatment is difficult as it must be continued for long periods, requires several drugs with adverse effects and proves very expensive, particularly for less developed countries. The most commonly used drugs are dapsone, rifampicin and clofazimine. Quinolones, such as ofloxacin and pefloxacin, as well as some macrolides, such as clarithromycin and minocyclin, are also effective. The present case report describes a patient with lepromatous leprosy acquired within a contagious family setting during childhood and adolescence

Adult native septic arthritis: a review of 10 years of experience and lessons for empirical antibiotic therapy.

Objectives To review the epidemiology of native septic arthritis to establish local guidelines for empirical antibiotic therapy as part of an antibiotic stewardship programme. Methods We conducted a 10 year retrospective study based on positive synovial fluid cultures and discharge diagnosis of septic arthritis in adult patients. Microbiology results and medical records were reviewed. Results Between 1999 and 2008, we identified 233 episodes of septic arthritis. The predominant causative pathogens were methicillin-susceptible Staphylococcus aureus (MSSA) and streptococci (respectively, 44.6% and 14.2% of cases). Only 11 cases (4.7%) of methicillin-resistant S. aureus (MRSA) arthritis were diagnosed, among which 5 (45.5%) occurred in known carriers. For large-joint infections, amoxicillin/clavulanate or cefuroxime would have been appropriate in 84.5% of cases. MRSA and Mycobacterium tuberculosis would have been the most frequent pathogens that would not have been covered. In contrast, amoxicillin/clavulanate would have been appropriate for only 75.3% of small-joint infections (82.6% if diabetics are excluded). MRSA and Pseudomonas aeruginosa would have been the main pathogens not covered. Piperacillin/tazobactam would have been appropriate in 93.8% of cases (P < 0.01 versus amoxicillin/clavulanate). This statistically significant advantage is lost after exclusion of diabetics (P = 0.19). Conclusions Amoxicillin/clavulanate or cefuroxime would be adequate for empirical coverage of large-joint septic arthritis in our area. A broad-spectrum antibiotic would be significantly superior for small-joint infections in diabetics. Systematic coverage of MRSA is not justified, but should be considered for known carriers. These recommendations are applicable to our local setting. They might also apply to hospitals sharing the same epidemiology.

Safety concerns about CCR5 as an antiviral target.

PURPOSE OF REVIEW: Clinical trials of CCR5 antagonists attest to their efficacy and tolerance in HIV treatment. However, there has been debate on their long-term safety because of the role of CCR5 in innate immunity. This review highlights gaps in our understanding of epidemiology of infections that are modulated by CCR5, in particular, in HIV-infected individuals. RECENT FINDINGS: In the mouse model, CCR5 has a role in the response against pathogens as diverse as Toxoplama gondii, West Nile virus, Mycobacterium tuberculosis, herpes simplex virus, Trypanosoma cruzi, Cryptococcus neoformans, Chlamydia trachomatis, Listeria, and plasmodia. In human cohorts, individuals carrying the defective CCR5Delta32 allele present an increased susceptibility to flavivirus (West Nile virus and tickborne encephalitis virus). The selective pressures that led to the spread of loss-of-function CCR5 mutations in humans (CCR5Delta32), and in mangabeys (CCR5Delta24) are not understood. SUMMARY: The recent availability of CCR5 antagonists has raised concern that genetic, biological, or chemical CCR5 knockout, although beneficial against some pathogens (i.e. HIV), could be deleterious for other processes implicated in pathogen response. The consequences of long-term pharmaceutical intervention on CCR5 should be carefully assessed through rigorous postmarketing surveillance.

La lymphadénite à mycobactérie atypique [Lymphadenitis due to atypical mycobacteria]

La lymphadénite est une maladie courante dans l'enfance et un motif fréquent de consultation pédiatrique ou ORL. Elle est habituellement due à une infection des voies respiratoires hautes et est autolimitée. Chez l'enfant présentant une lymphadénite cervicale subaiguë ou chronique qui ne répond pas aux antibiotiques habituels, une infection à mycobactérie atypique doit être évoquée. L'infection touche surtout les enfants en bonne santé entre un et cinq ans. Le diagnostic précoce est essentiel car le traitement de choix est l'exérèse des ganglions atteints, avant l'apparition d'une nécrose cutanée et d'une fistulisation. Cet article revoit les présentations cliniques spécifiques, les méthodes diagnostiques et le traitement des lymphadénites à mycobactéries atypiques. Cervical lymphadenitis is common in childhood and is a frequent source of consultation at the pediatrician's or ENT's office. It is usually caused by a viral upper respiratory tract infection and is self limited. In children with subacute or chronic cervical lymphadenitis which fails to respond to conventional antibiotics, infection due to atypical mycobacteria should always be considered. Infections occur predominantly in an otherwise healthy child of 1 to 5 years of age. The early diagnosis is essential as the treatment of choice is early surgical excision before skin necrosis and fistula occur. This article reviews the specific clinical manifestations, diagnostic tools and treatment of lymphadenitis due to atypical mycobacteria.

Tuberculosis diagnostics and biomarkers: needs, challenges, recent advances, and opportunities.

Tuberculosis is unique among the major infectious diseases in that it lacks accurate rapid point-of-care diagnostic tests. Failure to control the spread of tuberculosis is largely due to our inability to detect and treat all infectious cases of pulmonary tuberculosis in a timely fashion, allowing continued Mycobacterium tuberculosis transmission within communities. Currently recommended gold-standard diagnostic tests for tuberculosis are laboratory based, and multiple investigations may be necessary over a period of weeks or months before a diagnosis is made. Several new diagnostic tests have recently become available for detecting active tuberculosis disease, screening for latent M. tuberculosis infection, and identifying drug-resistant strains of M. tuberculosis. However, progress toward a robust point-of-care test has been limited, and novel biomarker discovery remains challenging. In the absence of effective prevention strategies, high rates of early case detection and subsequent cure are required for global tuberculosis control. Early case detection is dependent on test accuracy, accessibility, cost, and complexity, but also depends on the political will and funder investment to deliver optimal, sustainable care to those worst affected by the tuberculosis and human immunodeficiency virus epidemics. This review highlights unanswered questions, challenges, recent advances, unresolved operational and technical issues, needs, and opportunities related to tuberculosis diagnostics.

Taking the fungal highway: mobilization of pollutant-degrading bacteria by fungi.

The capacity of fungi to serve as vectors for the dispersion of pollutant-degrading bacteria was analyzed in laboratory model systems mimicking water-saturated (agar surfaces) and unsaturated soil environments (glass-bead-filled columns). Two common soil fungi (Fusarium oxysporum and Rhexocercosporidium sp.) forming hydrophilic and hydrophobic mycelia, respectively, and three polycyclic aromatic hydrocarbon degrading bacteria (Achromobacter sp. SK1, Mycobacterium frederiksbergense LB501TG, and Sphingomonas sp. L138) were selected based on the absence of mutual antagonistic effects. It was shown that fungal hyphae act as vectors for bacterial transport with mobilization strongly depending on the specific microorganisms chosen: The motile strain Achromobacter sp. SK1 was most efficiently spread along hyphae of hydrophilic F. oxysporum in both model systems with transport velocities of up to 1 cm d(-1), whereas no dispersion of the two nonmotile strains was observed in the presence of F. oxysporum. By contrast, none of the bacteria was mobilized along the hydrophobic mycelia of Rhexocercosporidium sp. growing on agar surfaces. In column experiments however, strain SK1 was mobilized by Rhexocercosporidium sp. It is hypothesized that bacteria may move by their intrinsic motilitythrough continuous (physiological) liquid films forming around fungal hyphae. The results of this study suggest that the specific stimulation of indigenous fungi may be a strategy to mobilize pollutant-degrading bacteria leading to their homogenization in polluted soil thereby improving bioremediation.

Amoebal pathogens as emerging causal agents of pneumonia.

Despite using modern microbiological diagnostic approaches, the aetiological agents of pneumonia remain unidentified in about 50% of cases. Some bacteria that grow poorly or not at all in axenic media used in routine clinical bacteriology laboratory but which can develop inside amoebae may be the agents of these lower respiratory tract infections (RTIs) of unexplained aetiology. Such amoebae-resisting bacteria, which coevolved with amoebae to resist their microbicidal machinery, may have developed virulence traits that help them survive within human macrophages, i.e. the first line of innate immune defence in the lung. We review here the current evidence for the emerging pathogenic role of various amoebae-resisting microorganisms as agents of RTIs in humans. Specifically, we discuss the emerging pathogenic roles of Legionella-like amoebal pathogens, novel Chlamydiae (Parachlamydia acanthamoebae, Simkania negevensis), waterborne mycobacteria and Bradyrhizobiaceae (Bosea and Afipia spp.).

Lepromatous leprosy: a review and case report

Leprosy is a contagious and chronic systemic granulomatous disease caused by Mycobacterium leprae (Hansen"s bacillus). It is transmitted from person to person and has a long incubation period (between two and six years). The disease presents polar clinical forms (the"multibacillary" lepromatous leprosy and the"paucibacillary" tuberculoid leprosy), as well as other intermediate forms with hybrid characteristics. Oral manifestations usually appear in lepromatous leprosy and occur in 20-60% of cases. They may take the form of multiple nodules (lepromas) that progress to necrosis and ulceration. The ulcers are slow to heal, and produce atrophic scarring or even tissue destruction. The lesions are usually located on the hard and soft palate, in the uvula, on the underside of the tongue, and on the lips and gums. There may also be destruction of the anterior maxilla and loss of teeth. The diagnosis, based on clinical suspicion, is confirmed through bacteriological and histopathological analyses, as well as by means of the lepromin test (intradermal reaction that is usually negative in lepromatous leprosy form and positive in the tuberculoid form). The differential diagnosis includes systemic lupus erythematosus, sarcoidosis, cutaneous leishmaniasis and other skin diseases, tertiary syphilis, lymphomas, systemic mycosis, traumatic lesions and malignant neoplasias, among other disorders. Treatment is difficult as it must be continued for long periods, requires several drugs with adverse effects and proves very expensive, particularly for less developed countries. The most commonly used drugs are dapsone, rifampicin and clofazimine. Quinolones, such as ofloxacin and pefloxacin, as well as some macrolides, such as clarithromycin and minocyclin, are also effective. The present case report describes a patient with lepromatous leprosy acquired within a contagious family setting during childhood and adolescence

Mykobakteerien lajinmääritykseen käytettävän kitin validointi

Tämä opinnäytetyö tehtiin Elintarviketurvallisuusvirasto Eviran Helsingin yksikön eläintautibakteriologian ryhmälle. Työn tarkoituksena oli löytää ja ottaa käyttöön tämänhetkisen AccuProbe-menetelmän lisäksi monipuolisempi menetelmä mykobakteerien lajinmääritykseen. AccuProbe-testillä pystytään tunnistamaan suurin osa Eviraan tulleista näytteistä eristetyistä mykobakteereista, mutta muun muassa kalanäytteistä eristettyjen mykobakteerien tunnistamiseen ei ole ollut menetelmää. Työhön valittiin GenoType® Mycobacterium CM -kitti. Mykobakteerien lajinmääritykseen kehitetyn GenoType® Mycobacterium CM -kitin käyttöä opeteltiin aluksi Mycobacterium avium ATCC 25291 -kannalla. Tämän jälkeen kittiä kokeiltiin eläimistä eristetyillä sekä M. intracellulare ATCC 13950- ja M. tuberculosis ATCC 25177 -kannoilla. Kyseessä on hybridisaatioon perustuva DNA-liuska-menetelmä, joka sisältää kolme päävaihetta: DNA:n eristäminen, monistaminen PCR:llä ja hybridisaatio. Työn aikana optimoitiin substraatin vaikutusaikoja, seurattiin hybrisaatiovaiheen lämpötiloja ja kehitettiin kitin valmistajan suosittelemaa ravistelevaa lämpöhaudetta / inkubaattoria vastaavia laitteita. Työn tuloksena kitti on käyttövalmis, mutta menetelmän soveltuvuutta eläinkannoille täytyy testata lisää. Osassa tulosliuskoissa oli vääriä vaaleita viivoja ja osa oikeista vaaleista viivoista puuttui. Saadut tulokset antavat kuitenkin hyvän pohjan jatkaa kitin validointia.

Infecção pulmonar tripla em paciente gravemente imunocomprometido por AIDS: relato de caso

Os autores relatam um caso de paciente do sexo masculino, 38 anos de idade, motorista, soropositivo para HIV há oito anos, sem acompanhamento, com quadro de tosse produtiva com secreção acinzentada e episódios intermitentes de dispnéia há 15 dias. Informava dois episódios pregressos de tuberculose pulmonar (1983 e 2001) tratados. A radiografia de tórax evidenciou áreas de hipotransparência nodular e broncogramas aéreos bilateralmente. A tomografia computadorizada de tórax evidenciou vários achados inespecíficos, dentre eles áreas esparsas de consolidação, cavitação, bronquiectasia, opacidade em vidro fosco, espessamento intersticial e broncogramas aéreos. A lavagem broncoalveolar evidenciou numerosas hifas com raros septos bifurcados sugestivos de Aspergillus sp. e a cultura foi positiva para Nocardia sp. e Mycobacterium tuberculosis. Foi instituída terapia com anfotericina B, sulfametoxazol-trimetoprim e anti-retrovirais. Após 20 dias, recebeu alta sem queixas pulmonares. Decorridos 15 dias, retornou com diarréia, febre, disfagia e emagrecimento importante. Foi a óbito após cinco dias, por sepse estafilocócica.

Tuberculose pancreática: relato de caso e revisão da literatura

O pâncreas é raramente afetado por infecções pelo bacilo Mycobacterium tuberculosis, provavelmente em função da presença das enzimas pancreáticas, e apenas alguns casos são descritos na literatura. O diagnóstico diferencial com carcinoma pancreático é um desafio em virtude das semelhanças clínico-radiológicas. Apresentamos um caso de um paciente de 39 anos de idade, do sexo masculino, com quadro clínico de perda ponderal, náuseas e vômitos. A propedêutica radiológica com tomografia computadorizada de abdome revelou lesões em cauda do pâncreas e baço. O diagnóstico foi confirmado por exame histopatológico após laparotomia.

Nanocarriers for DNA Vaccines: Co-Delivery of TLR-9 and NLR-2 Ligands Leads to Synergistic Enhancement of Proinflammatory Cytokine Release

Adjuvants enhance immunogenicity of vaccines through either targeted antigen delivery or stimulation of immune receptors. Three cationic nanoparticle formulations were evaluated for their potential as carriers for a DNA vaccine, and muramyl dipeptide (MDP) as immunostimulatory agent, to induce and increase immunogenicity of Mycobacterium tuberculosis antigen encoding plasmid DNA (pDNA). The formulations included (1) trimethyl chitosan (TMC) nanoparticles, (2) a squalene-in-water nanoemulsion, and (3) a mineral oil-in-water nanoemulsion. The adjuvant effect of the pDNA-nanocomplexes was evaluated by serum antibody analysis in immunized mice. All three carriers display a strong adjuvant effect, however, only TMC nanoparticles were capable to bias immune responses towards Th1. pDNA naturally contains immunostimulatory unmethylated CpG motifs that are recognized by Toll-like receptor 9 (TLR-9). In mechanistic in vitro studies, activation of TLR-9 and the ability to enhance immunogenicity by simultaneously targeting TLR-9 and NOD-like receptor 2 (NLR-2) was determined by proinflammatory cytokine release in RAW264.7 macrophages. pDNA in combination with MDP was shown to significantly increase proinflammatory cytokine release in a synergistic manner, dependent on NLR-2 activation. In summary, novel pDNA-Ag85A loaded nanoparticle formulations, which induce antigen specific immune responses in mice were developed, taking advantage of the synergistic combinations of TLR and NLR agonists to increase the adjuvanticity of the carriers used.