-
Journal of Clinical Tuberculosis and... Aug 2017is an uncommonly encountered acid-fast staining bacillus (AFB) that can cause a broad range of infections. We describe a tertiary care center's experience with... (Review)
Review
is an uncommonly encountered acid-fast staining bacillus (AFB) that can cause a broad range of infections. We describe a tertiary care center's experience with infections identified from 2000 to 2015. Ten adult patients were identified with infections, and most had immunocompromising conditions. presented in one of two syndromes: a peripheral cutaneous infection presenting with skin nodularity and local invasion, and a cervicofacial infection involving regional lymph nodes. Duration of therapy was variable (0-18 months) and was dependent on the underlying syndrome and immunological status of the patient. Treatment responses were favorable in all patients. During therapy, three patients developed culture-negative aseptic cutaneous lesions, consistent with immunologic reconstitution inflammatory syndrome (IRIS); we postulate that such reactions may not be uncommon with select infections.
PubMed: 31723708
DOI: 10.1016/j.jctube.2017.06.002 -
Journal of the American Association For... Mar 2017Mycobacterium spp. infections are common in zebrafish kept in research facilities. These comorbidities can substantially modulate the responses of these fish to external...
Mycobacterium spp. infections are common in zebrafish kept in research facilities. These comorbidities can substantially modulate the responses of these fish to external and internal stimuli. Therefore, diagnostic tests to detect Mycobacterium spp. infections in zebrafish colonies prove essential. Here, we outline the development of quantitative simplex real-time PCR assays to detect the 3 Mycobacterium species most commonly identified in laboratory zebrafish. The assays targeted the heatshock protein 65 gene of M. marinum, M. chelonae, and M. haemophilum. The assays are both highly specific and sensitive for fresh-frozen samples and highly specific and moderately sensitive for formalin-fixed paraffin-embedded (FFPE) samples. Two sampling techniques for FFPE samples of sagittally sectioned zebrafish were evaluated. Both paraffin cores targeting granulomas containing bacteria and scrolls from the entire fish yielded DNA of equivalent quantity and purity. The diagnostic sensitivity of cores was superior to that of scrolls for M. chelonae and M. haemophilum but not M. marinum. The assays are cost-effective and ideally suited to diagnosing common Mycobacterium spp. infections in zebrafish.
Topics: Animals; Fish Diseases; Laboratory Animal Science; Mycobacterium; Mycobacterium Infections; Real-Time Polymerase Chain Reaction; Zebrafish
PubMed: 28315641
DOI: No ID Found -
International Journal of... Dec 2016Mycobacterium haemophilum is a slow-growing nontuberculous mycobacterium (NTM) that can cause ulcerating cutaneous or subcutaneous nodular skin lesions in...
INTRODUCTION
Mycobacterium haemophilum is a slow-growing nontuberculous mycobacterium (NTM) that can cause ulcerating cutaneous or subcutaneous nodular skin lesions in immunocompromised and immunocompetent patients. Acid-fast staining cannot distinguish NTM from M. tuberculosis; culturing at two temperatures with iron-supplemented media and polymerase chain reaction (PCR) are needed for optimal detection of M. haemophilum.
CASE PRESENTATION
A 32-year-old man with end-stage renal disease, undergoing hemodialysis twice a week, presented with multiple, painless, nonpruritic nodular lesions. A formalin-fixed paraffin-embedded tissue block from his finger lesion was sent to the Department of Pathology, Masih Daneshvari Hospital for consultation. The lesions were primarily diagnosed to be dermatofibroma by another pathologist. On microscopic examination, vague granuloma with areas of necrosis was observed. The diagnosis was established by positive acid-fast staining, negative PCR results for M. tuberculosis complex, and positive nested PCR results for M. haemophilum.
CONCLUSION
Cutaneous lesions in immunocompromised patients with positive results in acid-fast staining and negative results for M. tuberculosis should be further assessed using skin culture and molecular techniques to identify rare, atypical mycobacterial species like M. haemophilum.
PubMed: 28043577
DOI: 10.1016/j.ijmyco.2016.09.024 -
Microbiology Spectrum Nov 2016The list of clinically important slow-growing nontuberculous mycobacteria (NTM) continues to expand as new species are identified and older ones are found to be... (Review)
Review
The list of clinically important slow-growing nontuberculous mycobacteria (NTM) continues to expand as new species are identified and older ones are found to be pathogenic. Based on pigment production, the strains may be classified as photochromogenic, scotochromogenic, or unpigmented. Some of these organisms are not newly discovered but have heretofore been considered virtually nonpathogenic. Previously, many were regarded as contaminants when isolated from clinical specimens. Ubiquitous in nature, many NTM have been isolated from groundwater or tap water, soil, house dust, domestic and wild animals, and birds. Most infections result from inhalation or direct inoculation from environmental sources. They are not spread from person to person. The infections may be localized or disseminated. In most cases, the optimal regimen or duration of therapy has not been firmly established. The results of in vitro susceptibility testing may be used to select a therapeutic regimen. Many experts recommend clarithromycin with companion drugs such as rifampin and ethambutol for most, but not all, slowly growing species. Aminoglycosides, clofazimine, fluoroquinolones, linezolid, pyrazinamide, or trimethoprim-sulfamethoxazole also may be effective against some strains. Immunocompetent patients with clinically significant infections with NTM usually should receive 18 to 24 months of therapy. Infected immunocompromised patients, particularly those with disseminated infection, probably should receive therapy as long as their immune systems remain impaired. Some of the species discussed include Mycobacterium alsiense, M. celatum, M. gordonae, M. haemophilum, M. kyorinense, M. malmoense, M. simiae complex, M. szulgai, M. terrae complex, M. ulcerans, and M. xenopi.
Topics: Anti-Bacterial Agents; Antitubercular Agents; Environmental Microbiology; Humans; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; Rifampin
PubMed: 27837745
DOI: 10.1128/microbiolspec.TNMI7-0012-2016 -
BMJ Case Reports Oct 2016Opportunistic infections are a major concern in renal and transplant medicine. We present the case of a renal transplant recipient with a generalised Mycobacterium...
Opportunistic infections are a major concern in renal and transplant medicine. We present the case of a renal transplant recipient with a generalised Mycobacterium haemophilum infection after an increase in immunosuppressive therapy and treatment with a tumour necrosis factor-α (TNF-α) inhibitor. Infection involved skin and soft tissue, joints and bones, as well as the renal transplant with an interstitial nephritis. Rapid diagnosis using PCR and DNA sequencing allowed early appropriate treatment. Triple antibiotic therapy and reduction in immunosuppression resulted in a slow but sustained recovery. Immunosuppression causes severe opportunistic infections. TNF-α inhibitors are very effective and well tolerated but have an increased susceptibility to infections with mycobacteria. Mycobacterial infections represent a significant clinical risk to transplant recipients because of their aggressive clinical course and the need for complex toxic antibiotic treatments. In these patients, M. haemophilum is a cause of skin infections.
Topics: Adult; Antitubercular Agents; Biopsy; Humans; Immunocompromised Host; Immunosuppressive Agents; Kidney Function Tests; Kidney Transplantation; Male; Mycobacterium Infections; Mycobacterium haemophilum; Opportunistic Infections
PubMed: 27799227
DOI: 10.1136/bcr-2016-216042 -
PloS One 2016Accurate identification of slowly growing nontuberculous mycobacteria (SG-NTM) of clinical significance remains problematic. This study evaluated a novel method of...
16S-23S Internal Transcribed Spacer Region PCR and Sequencer-Based Capillary Gel Electrophoresis has Potential as an Alternative to High Performance Liquid Chromatography for Identification of Slowly Growing Nontuberculous Mycobacteria.
Accurate identification of slowly growing nontuberculous mycobacteria (SG-NTM) of clinical significance remains problematic. This study evaluated a novel method of SG-NTM identification by amplification of the mycobacterial 16S-23S rRNA internal transcribed spacer (ITS) region followed by resolution of amplified fragments by sequencer-based capillary gel electrophoresis (SCGE). Fourteen American Type Culture Collection (ATCC) strains and 103 clinical/environmental isolates (total n = 24 species) of SG-NTM were included. Identification was compared with that achieved by high performance liquid chromatography (HPLC), in-house PCR and 16S/ITS sequencing. Isolates of all species yielded a SCGE profile comprising a single fragment length (or peak) except for M. scrofulaceum (two peaks). SCGE peaks of ATCC strains were distinct except for peak overlap between Mycobacterium kansasii and M. marinum. Of clinical/environmental strains, unique peaks were seen for 7/17 (41%) species (M. haemophilum, M. kubicae, M. lentiflavum, M. terrae, M. kansasii, M. asiaticum and M. triplex); 3/17 (18%) species were identified by HPLC. There were five SCGE fragment length types (I-V) each of M. avium, M. intracellulare and M. gordonae. Overlap of fragment lengths was seen between M. marinum and M. ulcerans; for M. gordonae SCGE type III and M. paragordonae; M. avium SCGE types III and IV, and M. intracellulare SCGE type I; M. chimaera, M. parascrofulaceum and M. intracellulare SCGE types III and IV; M. branderi and M. avium type V; and M. vulneris and M. intracellulare type V. The ITS-SCGE method was able to provide the first line rapid and reproducible species identification/screening of SG-NTM and was more discriminatory than HPLC.
Topics: Base Sequence; Chromatography, High Pressure Liquid; DNA, Ribosomal Spacer; Electrophoresis, Capillary; Humans; Multiplex Polymerase Chain Reaction; Mycobacterium Infections, Nontuberculous; Nontuberculous Mycobacteria; RNA, Ribosomal, 16S; RNA, Ribosomal, 23S; Real-Time Polymerase Chain Reaction; Reproducibility of Results; Species Specificity
PubMed: 27749897
DOI: 10.1371/journal.pone.0164138 -
Zebrafish Jul 2016Considering the numbers of zebrafish held in the laboratories, it is relevant to develop some tools to monitor the health of the animals, as well as their biotope....
Considering the numbers of zebrafish held in the laboratories, it is relevant to develop some tools to monitor the health of the animals, as well as their biotope. Environmental samples can be used to detect aquatic pathogens. Comprehensive health monitoring would thus seek pathogens in three dimensions of the animals and microbes' habitat: the fish, the sludge, and the water. This three-dimensional approach is called the 3D screen and it introduces some complementary tools to routine sentinel screening. For example, sludge and sump swabs analyses allow an efficient detection of pathogens at a low cost and with a fast turnover. These assays are particularly useful in cases of Pseudocapillaria tomentosa infestation or Mycobacterium haemophilum outbreak. Indeed, such a broader choice of diagnostic tests gives flexibility for the veterinarian to investigate Mycobacterium spp. presence in the water systems and fish colonies. Some other robust additional analysis, like the mortality rate monitoring, quickens the decision-making process. The 3D screen describes how this new toolbox can be used efficiently to monitor laboratory fish health.
Topics: Animal Husbandry; Animal Welfare; Animals; Aquaculture; Enoplida Infections; Fish Diseases; Mycobacterium Infections; Mycobacterium haemophilum; Sentinel Surveillance; Trichuroidea; Zebrafish
PubMed: 27182750
DOI: 10.1089/zeb.2015.1200 -
MBio Nov 2015Mycobacterium haemophilum is an emerging pathogen associated with a variety of clinical syndromes, most commonly skin infections in immunocompromised individuals....
UNLABELLED
Mycobacterium haemophilum is an emerging pathogen associated with a variety of clinical syndromes, most commonly skin infections in immunocompromised individuals. M. haemophilum exhibits a unique requirement for iron supplementation to support its growth in culture, but the basis for this property and how it may shape pathogenesis is unclear. Using a combination of Illumina, PacBio, and Sanger sequencing, the complete genome sequence of M. haemophilum was determined. Guided by this sequence, experiments were performed to define the basis for the unique growth requirements of M. haemophilum. We found that M. haemophilum, unlike many other mycobacteria, is unable to synthesize iron-binding siderophores known as mycobactins or to utilize ferri-mycobactins to support growth. These differences correlate with the absence of genes associated with mycobactin synthesis, secretion, and uptake. In agreement with the ability of heme to promote growth, we identified genes encoding heme uptake machinery. Consistent with its propensity to infect the skin, we show at the whole-genome level the genetic closeness of M. haemophilum with Mycobacterium leprae, an organism which cannot be cultivated in vitro, and we identify genes uniquely shared by these organisms. Finally, we identify means to express foreign genes in M. haemophilum. These data explain the unique culture requirements for this important pathogen, provide a foundation upon which the genome sequence can be exploited to improve diagnostics and therapeutics, and suggest use of M. haemophilum as a tool to elucidate functions of genes shared with M. leprae.
IMPORTANCE
Mycobacterium haemophilum is an emerging pathogen with an unknown natural reservoir that exhibits unique requirements for iron supplementation to grow in vitro. Understanding the basis for this iron requirement is important because it is fundamental to isolation of the organism from clinical samples and environmental sources. Defining the molecular basis for M. haemophilium's growth requirements will also shed new light on mycobacterial strategies to acquire iron and can be exploited to define how differences in such strategies influence pathogenesis. Here, through a combination of sequencing and experimental approaches, we explain the basis for the iron requirement. We further demonstrate the genetic closeness of M. haemophilum and Mycobacterium leprae, the causative agent of leprosy which cannot be cultured in vitro, and we demonstrate methods to genetically manipulate M. haemophilum. These findings pave the way for the use of M. haemophilum as a model to elucidate functions of genes shared with M. leprae.
Topics: Base Sequence; Culture Media; Genome, Bacterial; Heme; Hemoglobins; Humans; Iron; Mycobacterium haemophilum; Mycobacterium leprae; Oxazoles; Phenotype; Sequence Analysis, DNA
PubMed: 26578674
DOI: 10.1128/mBio.01313-15 -
Dermatology Reports May 2015Non-tuberculous mycobacteria (NTM) are a group of environmental pathogens, which cause a broad spectrum of disease. The incidence of NTM infection is increasing,...
Non-tuberculous mycobacteria (NTM) are a group of environmental pathogens, which cause a broad spectrum of disease. The incidence of NTM infection is increasing, especially in immunocompromized patients. The past three decades also saw a rapid increase in the incidence of NTM infection involving otherwise healthy subjects. We report a case of cutaneous NTM infection in a 79-year-old Chinese woman, who was receiving methotrexate for psoriasis. Mycobacterial culture grew Mycobacterium abscessus, and the lesions cleared with a combination of oral clarithromycin, ciprofloxacin and doxycycline. Interestingly, she then developed a second episode of cutaneous NTM infection with Mycobacterium haemophilum over the same body region, five years after stoppage of methotrexate. Both episodes were separated in time and involved different species, indicating that they were independent from each other. We further discuss the risk factors for cutaneous NTM infection, treatment, and highlight the need for diagnostic vigilance.
PubMed: 26236445
DOI: 10.4081/dr.2015.5712 -
Journal of Infection in Developing... Mar 2015We report the first case of an immunocompromised adult patient presenting with cervicofacial lymphadenitis due to Mycobacterium haemophilum, confirmed using hsp65 gene...
We report the first case of an immunocompromised adult patient presenting with cervicofacial lymphadenitis due to Mycobacterium haemophilum, confirmed using hsp65 gene sequencing and line-probe assays. In resource-limited settings, especially in developing countries, appropriate culture methods and rapid molecular diagnostic tools such as hsp65 gene sequencing for identification of this organism may not be readily available. This may cause M. haemophilum infections to go unrecognised or lead to delays in diagnosis. Lack of heightened awareness about the potential for this mycobacterial species to cause infections may also contribute to possible underestimation of M. haemophilum cases in the developing world.
Topics: Adult; Bacterial Proteins; Chaperonin 60; DNA, Bacterial; Face; Female; Humans; Immunocompromised Host; Lymphadenitis; Molecular Diagnostic Techniques; Mycobacterium Infections; Mycobacterium haemophilum; Neck
PubMed: 25771471
DOI: 10.3855/jidc.5208