Comparison of manual mycobacteria growth indicator tube and epsilometer test with agar proportion method for susceptibility testing of Mycobacterium tuberculosis

Background and Objectives: Antimycobacterial susceptibility tests take weeks, and delayed therapy can lead to spread of Mycobacterium tuberculosis. Therefore, rapid, accurate and cost-effective methods are required for proper therapy selection. In this study, the Mycobacteria growth indicator tube (MGIT) and epsilometer test (Etest) methods were compared to the agar proportion method for susceptibility testing of Mycobacterium tuberculosis. Materials and Methods: The susceptibility tests against isoniazid (INH), rifampin (RIF), streptomycin (STM) and ethambutol (ETM) of 51 M. tuberculosis complex isolates were analyzed by the MGIT, Etest and agar proportion methods. Results: The concordance between MGIT/Etest and agar proportion methods was 98% for INH and 100% for RIF, STM, ETM. There were not statistically significant differences in results of the susceptibility tests between MGIT/Etest and the reference agar proportion method. Conclusion: The results have shown that MGIT and Etest methods can be used instead of the agar proportion method, because these two methods are more rapid and easier than the agar proportion method.     

分枝杆菌肉芽肿形成的细胞及分子机制究进展

分枝杆菌肉芽肿是由细菌与不同的宿主细胞如巨噬细胞、树突细胞、淋巴细胞等相互作用,在各种免疫分子如细胞因子、黏附分子、补体等参与下,形成的特征性病理学结构.其形成过程中细菌各种成分、宿主不同细胞、产生的不同免疫分子均起重要作用.而斑马鱼模型的建立及原位荧光观察方法的应用亦为分枝杆菌尤其是海鱼分枝杆菌感染肉芽肿的体内形成及演变研究提供基础.     

腺苷脱氨酶、结核抗体及DNA联合检测在结核性积液的临床诊断价值

目的:探讨腺苷脱氨酶( ADA)、结核抗体(TB-Ab)、TB-DNA联合检测在结核性积液的临床诊断价值.方法:选择87例胸腔积液进行分析,其中结核组38例,非结核组49例,比较3种检测方法的检测情况及单独检测和联合检测的方法学指标.结果:两组别3种检测方法的阳性率经卡方检验分析,有统计学差异(P＜0.05),在结核组中3种检测方法阳性率经卡方检验分析比较,有统计学差异(P＜0.05),3种检测方法以TB-DNA阳性率最高,3种方法联合检测灵敏度为92.1％,特异度以TB-DNA最高为97.9％.结论:3种方法联合检测可提高灵敏度,提高结核杆菌的检出率,方法学指标综合分析,以TB-DNA检测为优.     

Searching for the Cartilage-associated Mimicry Epitope in Adjuvant Arthritis

Adjuvant arthritis (AA) is a T cell mediated disease which can be induced in genetically susceptible rats by immunization with heat-killed Mycobacterium tuberculosis ( Mt ) suspended in incomplete Freund's adjuvant. The critical mycobacterial T cell epitope for the induction of AA was previously identified as residues 178-186 of the mycobacterial 65 kDa heat shock protein ( Mt. hsp65 178-186 ). It was suggested that the development of AA was due to molecular mimicry between a mycobacterial epitope and a cartilage-associated self-antigen. However, until now such cartilage-associated mimicry epitope has not been identified. In this study we designed a computer search profile to predict mimicry self-epitopes, and investigated whether one or more of these self-epitopes could serve as mimicry epitopes in AA. Although several of these self-epitopes were recognized by arthritogenic T cells, no cross-reactivity was found between T cells specific for these self-epitopes and Mt. hsp65 178-186 specific T cells.     

Phagocytosis and cytokine response to rough and smooth colony variants of Mycobacterium abscessus by human peripheral blood mononuclear cells

Mycobacterium abscessus is a non‐tuberculous mycobacteria able to cause opportunistic infections in selected patient groups. During the last decades it has emerged as a cause of chronic pulmonary infection in patients with cystic fibrosis (CF). M. abscessus strains exhibit either smooth or rough colony morphology. Strains exhibiting the rough phenotype more often cause pulmonary infections in CF patients than did the smooth ones. Here, we examined phagocytosis and production of cytokines by human peripheral blood mononuclear cells, in response to M. abscessus strains with smooth and rough colony phenotype. The rough isolates all formed multicellular cords, similar to what is observed in Mycobacterium tuberculosis. Monocytes were generally unable to internalize these rough cord isolates, in contrast with the smooth ones. Furthermore, the rough M. abscessus strains induced a distinct cytokine profile differing from that induced by the smooth ones. Rough isolates induced significantly less IL‐10 and tumour necrosis factor compared to smooth strains, but more IL‐1β. Both varieties induced equal amounts of IFN‐γ, IL‐17, IL‐23, IL‐6, IL‐8 and equally little IL‐12. The ability to withstand phagocytosis might be a virulence factor contributing to the capacity of rough M. abscessus strains to give persistent pulmonary infections.     

Phase change material for thermotherapy of Buruli ulcer: modelling as an aid to implementation

A mathematical model was developed and validated to predict the thermal behaviour of a heat application device based on a phase change material (pcm) for the heat treatment of Mycobacterium ulcerans infection (Buruli ulcer). The thermal model allows the prediction of skin surface temperatures and an optimization of the amount of pcm with respect to discharge time. A first prototype of such a pcm bandage was manufactured and used in a proof-of-principal trial in Cameroon. The experimental data were analysed and yielded no difference in thermoregulatory response between people living in hot or moderate climate. Short-term maximum skin surface temperatures of 42°C are tolerable; the pcm bandage keeps the skin surface temperature above 40°C for about four to five hours. This makes such pcm bandages an ideal device for the heat treatment of Buruli ulcer. The pcm bandage is easy to apply, cheap, and thus is well suited for use in low-resource countries.     

Mycobacterium Kansasii and Osteoarticular Lesions

Four patients with an unusual type of bone lesion are reported. the histological diagnosis in two of them was non—specific chronic inflammation and one case was diagnosed as chronic eosinophilic granuloma. on subjecting the material to culture Mycobacterium Kansasii (a photochromogen) were isolated. It is suggested that M. Kansasii are capable of producing osteoarticular lesions with a rather vague clinical and radiological picture not typical of osteoarticular tuberculosis.     

Leprosy in transplant recipients: report of a case after liver transplantation and review of the literature

M.A.B. Trindade, M. de Lourdes Palermo, C. Pagliari, N. Valente, B. Naafs, P.C.B. Massarollo, L.A.C. D'Albuquerque, G. Benard. Leprosy in transplant recipients: report of a case after liver transplantation and review of the literature.
Transpl Infect Dis 2011: 13: 63–69. All rights reserved Abstract: Leprosy still is an important public health problem in several parts of the world including Brazil. Unlike the diseases caused by other mycobacteria, the incidence and clinical presentation of leprosy seems little affected in immunosuppressed patients. We report the first case, to our knowledge, of a liver transplant patient who developed multi‐bacillary leprosy. The patient presented with papules and infiltrated plaques with loss of sensation suggestive of leprosy 3.5 years after living‐related liver transplantation for autoimmune hepatitis. A skin biopsy showing non‐caseating macrophagic granulomas, neuritis, and intact acid‐fast bacilli on Fite‐Faraco stain, confirmed the diagnosis of borderline lepromatous leprosy. The donor of the liver did not show any evidence of leprosy. During follow‐up, the patient presented 2 episodes of upgrading leprosy type I reactions, 1 mild before leprosy treatment, and 1 moderate 3 months after receiving standard multi‐drug treatment (rifampicin, clofazimine, and dapsone). These reactions were accompanied by increase in liver function tests, especially of canalicular enzymes. This reaction occurred despite the patient's triple immunosuppression regimen. The moderate reaction was successfully treated with further immunosuppression (prednisone, 0.5 mg/kg). Currently, the patient is asymptomatic, off leprosy medication, with routine liver transplant follow‐up. The dilemmas in diagnosis and management of such a case are discussed and the literature on leprosy in transplant recipients is reviewed.     

The histopathologic spectrum of decorative tattoo complications

Tattooing for ornamental purposes is an ancient practice that remains popular in modern times. Tattoos are encountered by the dermatopathologist either as incidental findings on skin biopsies or because of complications specific to the tattoo. A range of neoplasms and inflammatory conditions are seen in association with tattoos, many of which may be attributed to hypersensitivity to tattoo inks. The composition of tattoo inks is highly variable, and inks can contain numerous potentially allergenic or carcinogenic compounds. Infections with bacterial, viral and fungal species can occur after tattooing, sometimes after substantial delay. Atypical mycobacterial infections in particular are increasingly reported; special stains for mycobacteria should be performed and cultures recommended particularly when dense, mixed or granulomatous infiltrates are present.