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A 5-month-old, male, 4 kg European shorthair cat presented with ulcera ted cutaneous nodules in many areas over its entire body. The serological results for feline immunodeficiency virus and the feline leukaemia virus were negative. Following detection of acid-proof bacilli in histological examination of three skin biopsies, the diagnosis of mycobacteriosis of the skin was made. Polymerase chain reaction revealed the presence of Mycobacterium lepraemurium . After surgical excision of all cutaneous nodules and a 14.5-week antibiotic therapy with Rifampicin and Clarithromycin, the cat was classified as being cured. During the observation period of 1 year after the end of the therapy, no relapse occurred., Competing Interests: Die Autoren bestätigen, dass kein Interessenkonflikt besteht., (Georg Thieme Verlag KG Stuttgart · New York.)

A 19-year old woman with acute myeloid leukemia presented with newly observed liver lesions during ongoing consolidation therapy. Due to unexplained cholestasis during induction, biliary duct drainage was performed. Microbiologic and histologic examinations revealed the presence of atypical mycobacteria, namely Mycobacterium abscessus. With an appropriate antiinfective regime which was continuously administered using a portable pump in the outpatient setting, further mycobacterial spread during simultaneous chemotherapy-associated neutropenia was prevented. Despite multiple bacterial resistance mechanisms, proper treatment of leukemia with curative intention could be ensured.

We report the case of a 36-year-old woman who presented with a surgical site infection with atypical mycobacteria several months after liposuction in the Caribbean. Postoperative wound infections with Mycobacterium abscessus present as subcutaneous nodular abscesses with partly putrid secretion. Due to the necessity of specific diagnostic measures, diagnosis is often delayed. Treatment is difficult because Mycobacterium abscessus is resistant to conventional tuberculostatics and many other antibiotics. Clarithromycin combined with amikacin is the commonly used empirical treatment. Treatment duration is several months.

Non-tuberculous mycobacteria are rarely responsible for skin and soft tissue infections. These infections are caused by different mycobacterial species originating from the environment (water, soil, plants, and animals). Various factors influence the clinical manifestation of the cutaneous infection: the immunological situation of the patient, the degree of cutaneous impairment, and the extent of the contact with the contaminated environment. The clinical manifestation is non-specific and often the cause of extensive diagnostic activities. The diagnosis is based on the cultural detection of the causative pathogen. The management of these skin and subcutaneous infections is a challenge for each physician. The treatment comprises administration of several antibiotics and antituberculosis drugs for many months. Surgical procedures are necessary in some patients.

Nontuberculous mycobacterium (NTM) species are mycobacterial species other than those belonging to the Mycobacterium tuberculosis complex and M. leprae. NTM are generally free-living organisms that are ubiquitous in the environment. Pulmonary disease, especially in older persons with and without underlying lung disease, is caused primarily by M. avium complex (MAC) and M. kansasii. The symptoms and signs of MAC lung disease are variable and not specific, but include cough, malaise, weakness, dyspnoea, chest discomfort and occasionally hemoptoe. Two major clinical presentations include disease in those with underlying lung disease, primarily white, middle-aged or elderly men - often alcoholics and/or smokers with underlying chronic obstructive lung disease, patients in whom MAC develops in areas of prior bronchiectasis, and patients with cystic fibrosis; and those without known underlying lung disease, including non-smoking women over age 50 who have interstitial patterns on chest radiography. M. kansasii infections are endemic in cities with infected tap water. Symptoms of the M. kansasii lung disease resemble to tuberculosis. M. abszessus is the most pathogenic rapid growing Mycobacterium which causes pulmonary infection. The American Thoracic Society and Infectious Disease Society of America's diagnostic criteria for nontuberculous mycobacterial pulmonary infections include both imaging studies consistent with pulmonary disease and recurrent isolation of mycobacteria from sputum or isolated from at least one bronchial wash in a symptomatic patient. For treatment of MAC lung disease we recommend depending on severity and susceptibility testing a three to four drug treatment with a macrolide, rifampicin and ethambutol and for M. kansasii a treatment with Isoniazid, rifampicin and ethambutol. Surgical management only plays a role in rare and special cases. Treatment should be continued until sputum cultures are consecutively negative for at least one year.

An overwhelming immune reaction resulting in granulomatous inflammation after infection with opportunistic pathogens is termed immune reconstitution inflammatory syndrome (IRIS). It has mainly been described in patients with human immunodeficiency virus (HIV) infection on highly active antiretroviral therapy (HAART) who show a significant increase of low CD4 T cells (initially <50/microl). IRIS may lead to organ damage and differential diagnosis is often difficult. We report the case of a 38-year-old female patient who developed a Mycobacteria genavense infection of the liver and the bowel after several immunosuppressive therapies for systemic lupus erythematosus. CD4 T cell counts as low as 17/microl were found and immunosuppressive therapy was stopped. Despite several courses of antibiotic treatment and rising CD4 T cell counts, severe malabsorption persisted. Upper endoscopy revealed a continuous inflammation with pseudopolyps of the small bowel and histologically, a granulomatous infiltrate was detected. After exclusion of a persisting infection by Mycobacteria genavense, IRIS of the small bowel was suspected and treatment with prednisolone was started. The clinical and histological picture improved significantly, the number of CD25(+)CD4(+) cells decreased in the lamina propria of the duodenum under treatment with prednisolone and Foxp3+ regulatory T cells (Treg) accumulated around granulomas. This case shows that IRIS is not restricted to HIV patients but may also occur in otherwise immunosuppressed patients. Due to different treatment strategies, distinguishing IRIS from infectious diseases is essential. The role of Treg in IRIS has to be elucidated.

Tuberculosis remains a leading cause of morbidity and mortality worldwide. A rapid and reliable diagnosis and discrimination from infections with nontuberculous mycobacteria (NTM) is critical. Frequently, formalin-fixed, paraffin-embedded (FFPE) tissues remain the only source for detection of micro-organisms in suspected cases of mycobacterial infection. Recently, numerous methods, including PCR assays, in situ hybridization and immunohistochemistry have been developed for detection of mycobacteria in FFPE samples. PCR-based assays are directed either against M.tbc.-specific sequences, such as IS6110, or amplify regions common to many mycobacterial species, e.g. the 65 kDa antigen, and then require sequencing or restriction fragment length polymorphism for species identification. Whereas the detection of DNA of M.tbc. in the correct setting is always of clinical relevance, the presence of various NTM species has to be interpreted with great caution due to their ubiquitous nature. However, the routine application of molecular tests has demonstrated that NTM infections are more common than previously thought, even in non-immunosuppressed hosts. The introduction of real-time PCR technology allows precise quantification of mycobacterial DNA and can be used for species identification through melting point analysis or appropriate DNA probes. Application of these assays originally developed for clinical microbiology offer a great opportunity for diagnostic improvement in molecular pathology as compared to qualitative PCR, mainly due to an increased specificity and a lower risk of contamination. Given the clinical impact of a positive molecular result for M. tbc., future efforts have to be aimed at standardization and quality control.

Background: Mycobacterial keratitis is a rare complication following LASIK but can lead to an extremely unfavourable outcome. The diagnosis and treatment is often delayed due to confusion with other entities including diffuse lamellar keratitis and poor clinical outcomes with flap amputation and/or keratoplasty are often the case., Patient and Methods: We report the results of LASIK in a 51-year-old woman with subsequent early-diagnosed mycobacterial keratitis and compared this case to treatments and outcomes reported in the literature., Results: The patient presented 10 days following LASIK with a white focal infiltrate in the stromal interface. The flap was lifted and cultures from the stromal bed and the reverse of the flap were obtained and the interface irrigated. The patient was treated with topical antibiotics (ciprofloxacin 0.3%, amikacin 2.5%, clarithromycin 40 mg/ml and tobramycin 15 mg/ml) for 8 weeks and at the most recent follow-up she had a visual acuity of 1.25., Conclusion: In a large number of published cases in the literature the flap had to be amputated and/or corneal transplants were necessary. Early diagnosis and treatment however, are essential to successfully treat post-LASIK keratitis. Therefore the patients should be followed up carefully in the early postoperative period.

History and Admission Findings: A 53-year-old man with known HIV infection and AIDS was admitted because of painful swelling at the right knee for 6 weeks. The cause was thought to be osteomyelitis and surgical treatment was planned., Investigations: No causative pathogen was found at curettage and lavage of an abscess at the right medical head of the tibia, but at a subsequent operative revision acid-fast rods were seen and identified as Mycobacterium haemophilum., Treatment and Course: A systemic antibiotic, 1 g levofloxacin daily, had been started at the initial abscess operation. 2 weeks later, because swelling of the right knee had recurred with marked local and systemic signs of infection, a second surgical intervention was performed. Afterwards, in view of the histological finding of acid-fast bacteria suggesting tubercular osteomyelitis, the patient was put on combined treatment with 300 mg/d of isoniazid, 1600 mg/d of ethambutol, 2 g/d of pyrazinamide, and 1 g of streptomycin i.m. every other day. After molecular microbiological identification of M. haemophilum the antibiotic treatment was changed to 1600 mg/d of ethambutol, 300 mg/d of rifabutin and 1 g/d of clarithromycin. The operation wound healed well., Conclusion: M. haemophilum infection can be lethal in immunodeficient patients if untreated. Although there is no standard treatment, this rare infectious disease responds relatively well to a modified combined tuberculostatic regimen. Special laboratory techniques to identify the specific causative pathogen are therefore of great importance.

PCR-based diagnosis of infectious diseases has developed into an important method in surgical pathology. We summarize our experience in this area based on 3500 analyses performed during the past 5 years. The peculiarity of material from a pathological laboratory is the risk of DNA fragmentation as a consequence of tissue fixation. For this reason the assays used must be adapted to this particular situation. PCR-based diagnosis of infectious diseases, if performed according to appropriate quality standards, is a safe and effective technique with high sensitivity and specificity and results in an etiologically based diagnosis.

Purpose: To examine the advantage of liver and brain MRI in clinically anomalous haematological patients with fever of unknown origin., Material and Methods: Twenty liver MRI (T2-TSE, T2-HASTE, T1-FLASH +/- Gd dynamic) and 16 brain MRI (T2-TSE, FLAIR, T1-TSE +/- Gd) were performed searching for a focus of fever with a suspected organ system. Comparison with clinical follow-up., Results: A focus was detected in 11/20 liver MRI. Candidiasis (n = 3), mycobacteriosis (n = 2), relapse of haematological disease (n = 3), graft versus host disease (n = 1), non-clarified (n02). The remaining 9 cases with normal MRI were not suspicious of infectious hepatic disease during follow-up. In brain MRI, 3/16 showed a focus (toxoplasmosis, aspergillosis, mastoiditis). Clinical indication for an infectious involvement of the brain was found in 4/16 cases 2-5 months after initially normal brain MRI. No suspicion of an infectious involvement of brain was present in the remaining 9/16 cases., Conclusion: In case of fever of unknown origin and suspicion of liver involvement, MRI of the liver should be performed due to data given in literature and its sensitivity of 100%. Because of the delayed detectability of cerebral manifestations, in cases of persisting suspicion even a previously normal MRI of the brain should be repeated.

The reemergence of tuberculosis in the industrialized countries has hastened the development of new laboratory techniques. Hence, well-known shortcomings of traditional techniques such as the lack of a rapid and specific detection system, the delayed availability of species identification and drug susceptibility results, and the lack of a reliable method for determining strain identity for epidemiological purposes, have become immediate targets for implementing molecular biology techniques. In particular, nucleic acid amplification techniques, restriction fragment-length polymorphism and single-strand conformation polymorphism analyses have dramatically improved diagnostic timeliness and accuracy of mycobacteriology laboratory results. Our paper reviews recent developments and comments on the diagnostic applications of the new tools as compared to traditional techniques.

30 patients infected with HIV (20 men, 10 women; mean age 34 [26-54] years), suspected of having Pneumocystis carinii (Pc) pneumonia, had undergone bronchoalveolar lavage which proved negative for Pc. They were then kept under observation for 5 months. No transbronchial biopsy was performed. 27 patients were in stage IV of the HIV infection, and 14 had been on pentamidine prophylaxis. The most frequent diagnosis with the bronchial lavage was bacterial infection (19 patients), next most frequent was mycobacterial infection (6, atypical in 5). A neoplasia (Kaposi sarcoma; non-Hodgkin lymphoma) was found in two, with pulmonary involvement. The diagnosis remained unclear in only three patients who were treated as for Pc pneumonia. The remaining 27 patients did not receive any treatment against Pc. Nonetheless, there were no cases of Pc pneumonia in the 5 months of observation so that bronchoalveolar lavage has a negative predictive value of 90% (27 of 30), high enough to make additional bronchial biopsy unnecessary.

In this contribution we analyzed the reliability and the diagnostic value of the results obtained by direct amplification of mycobacterial DNA from patient specimens. Presently, the PCR-method is not as sensitive as recommended culture techniques. In cases of low concentration of mycobacteria in specimens (microscopic negative!) false-negative PCR-results are not rare.

Comparative 16S rRNA sequencing allows to infer natural relationships among bacteria, to characterize and identify microorganisms at a molecular level and to develop DNA probes specific at any desired taxonomic level (e.g. family, genus, species). Probes targeted at ribosomal RNA are suitable for in situ hybridization of whole, intact bacterial cells as well as in polymerase-chain-reaction techniques for sensitive detection and identification of bacteria. Comparative 16S rRNA sequencing provided the basis for a systematic phylogenetic analysis of the genus Mycobacterium. Certain growth characteristics, i.e. thermotolerance and growth rate correspond to natural relationships among the mycobacteria. However, the phylogenetic relatedness within the slow-growing species did not reflect the Runyon classification of photochromogenic, scotochromogenic and nonphotochromogenic mycobacteria. The use of oligonucleotides targeted at highly or semi-conserved regions within the 16S rRNA molecule allows a universal procedure for amplification and rapid sequence determination of 16S rDNA-gene fragments from any virtually bacterial organism. This method of amplification of 16S rDNA-gene fragments was used to identify a novel, uncultured pathogen and opens new perspectives for other infectious diseases of unknown cause.

Microscopy is, for various reasons, even today the most important diagnostic measure for pulmonary Tb. With other forms of Tb and with other mycobacterioses there is a considerable increase in importance of the radiometric culture techniques, particularly if these are combined with serologic (ELISA and its variants) or molecular-genetic assays for the presence of mycobacteria. The latter, especially the so called genetic probes combined with the polymerase chain reaction, represent probably the assay of the future for mycobacteria; however, a stern warning must be sounded against the use of such techniques without previous experience in the field of the "classic" mycobacteriology. Serology is, inspite of recent enormous advances, still not capable of producing unequivocal results.

Infections having atypical mycobacteria are occurring more frequently for 2 main reasons. First there are the disturbances of the immunity system, whether due to the acquired immune deficiency syndrome (AIDS) or the result of therapeutic measures taken against malignant processes, other diseases or after organ transplantation. Second, travel and free-time activities increase the risk of an infection. In many cases such infections become localized on the skin, but can also develop changes in the lungs, depending on the patient's occupation. For this reason we provide a review of the new literature on the microbiology of mycobacteria as well as on the symptoms of diseases of the skin and other organs which are caused by atypical mycobacteria, such as swimming pool granuloma or Buruli ulcer.

In Germany the Working Group Mycobacteria was founded 15 years ago. During this period new methods have been introduced or improved. Today all new techniques are examined by quality control and the results are published in international journals or are reported at special meetings. That is why in Germany the diagnostic of mycobacteria has reached a very high level.

Clinical, microbiological and histological findings of the late phase of experimentally induced Mycoplasma-polyarthritis in rats are described. Investigations were carried out between the 7.-30. week and between the 54-61. week p.i. M. arthritidis could be reisolated from affected joints regularly up to the 7th week p.i. Thereafter until 12th week only occasional recovery was possible. The healing process of affected joints dominated signs of arthritis which could be confirmed histologically as a purulent process. The alterations of carpal and tarsal joints were divided into purulent, chronic deforming and chronic minor lesions. The findings derived from investigation of joints and parenchymatous organs during the course of the disease are discussed.

It is reported about the BCG-osteomyelitis in early childhood. A long intervall between BCG-vaccination and the onset of clinical symptoms, the good general condition of the patient, nearly unrestricted joint function, often negative bacteriological culture for the tubercle bacillus and negative guinea-pig test are characteristics. Even with extensive lesions of the epiphysis and metaphysis of the long bone and formation of an abscess, the course of the disease seems to be fairly benign. Operation is recommended for getting biopsy material for histological proof of the tuberculous process and for quicker healing.

Mycobacterial infections were confirmed in 629 HIV-infected persons (1.4%). Five patients had a generalized infection with Mycobacterium avium complex (MAC), four an extrapulmonary tuberculosis caused by Mycobacterium tuberculosis (M. tbc). In general, the tuberculosis was the first severe opportunistic infection, while infections with MAC were more frequent in patients with already manifest AIDS. Common to all patients were a septic temperature and definite shift to the left of neutrophil granulocytes. Four of five patients with MAC also had diarrhoea, and three of four with tuberculosis additionally had peripheral lymphomas. The chest x-ray films were normal in six of the nine patients. The diagnosis was made in six patients primarily by the microscopic demonstration of acid-fast bacteria in lymph node tissue or stool, in three patients by culture from blood or liver tissue. Microscopic stool examination was helpful: in three of five patients with MAC and one of two with M. tbc in the stool culture, acid-fast bacteria had already been demonstrated. In an individual case MAC infections could not be distinguished either clinically or morphologically from infections with M. tbc, but only by culture.

Atypical mycobacteria may cause pulmonary diseases - similar to tuberculosis - as well as infections of the lymph nodes, the skin and other organs. But only if several cultures from sputum or biopsy specimen have been positive and Mycobacterium tuberculosis has been excluded, these species can be noted as the pathogenetic agents. The course of disease mostly times appears uncharacteristic, the manifestations remind of chronic tuberculosis. The majority of patients with atypical mycobacterioses belong to the group with reduced host resistance (like AIDS, immunosuppression, malignancy). The outcome and prognosis without special treatment are deleterious. Because of the difference in the susceptibility of atypical mycobacteria to antituberculotic drugs a successful chemotherapy only can be made according to the analysis of resistance behaviour.

In a child aged 2 5/12 years with a suppurating pericarditis mycobacterium rhodochrous was grown from a blood culture and was regarded as the causative organism of the disease. By means of chemotherapy and surgical measures we succeeded in a complete cure of the process without complications. The problems of microbiological diagnostics, particularly of the taxonomic differentiation of these causative organisms as well the therapy of the infections produced by them are discussed.

Among 200 hospitalized patients treated for HIV infections there were 98 with gastrointestinal symptoms, independent of the stage of the disease. Only 22 had abnormal stool findings. But histological examination and culture of endoscopically obtained biopsies revealed opportunistic infection in 62, of whom 28 had a cytomegalovirus infection. Mycobacterium avium-intracellulare was found in the gastrointestinal mucosa of 25 patients, but its clinical significance is unclear. In 33 of the 98 patients previously classified as positive for HIV or AIDS-related complex, endoscopic demonstration of an opportunistic infection required amendment of their HIV stage. In over 60% endoscopy revealed mucosal changes. A distinction from Crohn's disease or ulcerative colitis could only be made by histology or exclusion of the causative microorganism. Demonstration of the causative microorganism from the biopsy is thus essential in patients with gastrointestinal symptoms, because specific treatment is in principle possible and successful for some opportunistic infections.