Massiliense Infection Research Articles

Evolution of Mycobacterium abscessus in the human lung: Cumulative mutations and genomic rearrangement of porin genes in patient isolates

ABSTRACT Background Mycobacterium abscessus subspecies massiliense (M. massiliense) is increasingly recognized as an emerging bacterial pathogen, particularly in cystic fibrosis (CF) patients and CF centres’ respiratory outbreaks. We characterized genomic and phenotypic changes in 15 serial isolates from two CF patients (1S and 2B) with chronic pulmonary M. massiliense infection leading to death, as well as four isolates from a CF centre outbreak in which patient 2B was the index case. Results Comparative genomic analysis revealed the mutations affecting growth rate, metabolism, transport, lipids (loss of glycopeptidolipids), antibiotic susceptibility (macrolides and aminoglycosides resistance), and virulence factors. Mutations in 23S rRNA, mmpL4, porin locus and tetR genes occurred in isolates from both CF patients. Interestingly, we identified two different spontaneous mutation events at the mycobacterial porin locus: a fusion of two tandem porin paralogs in patient 1S and a partial deletion of the first porin paralog in patient 2B. These genomic changes correlated with reduced porin protein expression, diminished 14C-glucose uptake, slower bacterial growth rates, and enhanced TNF-α induction in mycobacteria-infected THP-1 human cells. Porin gene complementation of porin mutants partly restored 14C-glucose uptake, growth rate and TNF-α levels to those of intact porin strains. Conclusions We hypothesize that specific mutations accumulated and maintained over time in M. massiliense, including mutations shared among transmissible strains, collectively lead to more virulent, host adapted lineages in CF patients and other susceptible hosts.

Pyruvate dehydrogenase kinase inhibitor dichloroacetate augments autophagy mediated constraining the replication of Mycobacteroides massiliense in macrophages

Increasing evidence indicates a strong interaction between cellular metabolism and innate macrophage immunity. Here, we show that the intracellular replication of Mycobacteroides massiliense in macrophages depends on host pyruvate dehydrogenase kinase (PDK) activity. Infection with M. massiliense induced a metabolic switch in macrophages by increasing glycolysis and decreasing oxidative phosphorylation. Treatment with dichloroacetate (DCA), a PDK inhibitor, converts this switch in M. massiliense-infected macrophages and restricts intracellular bacterial replication. Mechanistically, DCA resulted in AMPKα1 activation via increased AMP/ATP ratio, consequently inducing autophagy to constrain bacterial proliferation in the phagolysosome. This study suggests that the pharmacological inhibition of PDK could be a strategy for host-directed therapy to control virulent M. massiliense infections.

Atypical Mycobacteriosis Due to Mycobacterium abscessus subsp. massiliense: Our Experince.

Members of Micobacterium. abscessus complex comprises three subspecies (M. abscessus subsp. Abscessus, M. abscessus subsp. Bolletii, and M. abscessus subsp. Massiliense) and are a rapid-growing nontuberculous mycobacteria present in different aquatic habitats and soil. It often causes a wide spectrum of infections involving pulmonary infections, surgical wound infections, and infections related to mesotherapy, catheters, hemodialysis devices, endocarditis, and disseminated infections in immunocompromised individuals. In this article we comment on the most relevant aspects of nine patients with skin lesions caused by M. abscessus subsp. massiliense infection. Clinical characteristics, histopathology, and molecular identification were performed. The patients in the clinical cases presented a history of trauma, tattoos, and physical therapy techniques. The most common treatments were minocycline and clindamycin, doxycycline, ceftriaxone, cephalexin, moxifloxacin, rifampicin, and trimethoprim-sulfamethoxazole. The evolution of the treated patients was acceptable, except for one patient, who showed a partial improvement. M. massiliense were identified in all clinical cases using a species-specific PCR. Our series consisted of nine cases of skin biopsies recorded in different years; for this reason, we do not have all the data necessary for a complete description, in particular in four cases, causing limitations in the manuscript, especially in the therapy used and the evolution of patients due to lack of follow-up.

Pulmonary Disease due to Mycobacterium massiliense

We report a case of a patient suffering from multidrug-resistant pulmonary tuberculosis (MDR-PTB) who later developed an invasive infection of the respiratory tract with a rapidly growing non-tuberculous mycobacteria (NTM), recently identified as Mycobacterium massiliense, closely related to M. abscessus. To the best of our knowledge, this is the first case of M. massiliense infection being reported from India.

Case report of a near-fatal case of Mycobacterium massiliense sepsis after de-clotting of an arteriovenous fistula

BackgroundMycobacterium massiliense is a rapidly growing a non-tuberculous mycobacterium that has been validated as a separate species from the Mycobacterium abscessus group. Only few antibiotics have demonstrated germicidal activity against Mycobacterium massiliense, and some of those include amikacin, clarithromycin, and cefoxitin.Case presentationWe present the first reported case of near-fatal septic shock caused by disseminated Mycobacterium massiliense after de-clotting of an infected arteriovenous fistula, in a patient with end-stage renal disease with concomitant human immunodeficiency virus infection. Early recognition of the culprit organism and treatment with a combination therapy of clarithromycin and amikacin led to rapid improvement.ConclusionThis unique case can highlight the importance of taking into consideration Mycobacterium massiliense infection as a cause of arteriovenous fistula thrombosis and highlights the risk of disseminated infection leading to life threatening sepsis upon de-clotting of the fistula.

Phage Therapy for Mycobacterium Abscessus and Strategies to Improve Outcomes.

Members of Mycobacterium abscessus complex are known for causing severe, chronic infections. Members of M. abscessus are a new “antibiotic nightmare” as one of the most resistant organisms to chemotherapeutic agents. Treatment of these infections is challenging due to the either intrinsic or acquired resistance of the M. abscessus complex to the available antibiotics. Recently, successful phage therapy with a cocktail of three phages (one natural lytic phage and two engineered phages) every 12 h for at least 32 weeks has been reported against a severe case of the disseminated M. abscessus subsp. massiliense infection, which underlines the high value of phages against drug-resistant superbugs. This report also highlighted the limitations of phage therapy, such as the absence of lytic phages with a broad host-range against all strains and subspecies of the M. abscessus complex and also the risk of phage resistant bacteria over treatment. Cutting-edge genomic technologies have facilitated the development of engineered phages for therapeutic purposes by introducing new desirable properties, changing host-range and arming the phages with additional killing genes. Here, we review the available literature and suggest new potential solutions based on the progress in phage engineering that can help to overcome the present limitations of M. abscessus treatment.

Disseminated Mycobacterium abscessus subsp. massiliense infection in a Good\u2019s syndrome patient negative for human immunodeficiency virus and anti-interferon-\u03b3 autoantibody: a case report

BackgroundGood’s syndrome (GS) is characterized by immunodeficiency, and can lead to severe infection, which is the most significant complication. Although Mycobacterium rarely causes infection in patients with GS, disseminated nontuberculous mycobacterial (NTM) infection frequently occurs in GS patients that are also positive for the human immunodeficiency virus (HIV) or anti-interferon (IFN)-γ autoantibodies. Here, we report a rare case of GS with NTM without HIV or IFN-γ autoantibodies.Case presentationA 57-year-old Japanese male with GS and myasthenia gravis (treated with prednisolone and tacrolimus) was diagnosed with disseminated NTM infection caused by Mycobacterium abscessus subsp. massiliense. He presented with fever and back pain. Blood, lumbar tissue, urine, stool, and sputum cultures tested positive for M. abscessus. Bacteremia, spondylitis, intestinal lumber abscess, and lung infection were confirmed by bacteriological examination and diagnostic imaging; urinary and intestinal tract infections were suspected by bacteriological examination but not confirmed by imaging. Despite multidrug combination therapy, including azithromycin, imipenem/cilastatin, levofloxacin, minocycline, linezolid, and sitafloxacin, the patient ultimately died of the infection. The patient tested negative for HIV and anti-IFN-γ autoantibodies.ConclusionsSince myasthenia gravis symptoms interfere with therapy, patients with GS and their physicians should carefully consider the antibacterial treatment options against disseminated NTM.

In vitro efficacy of combinations of eight antimicrobial agents against Mycobacteroides abscessus complex

ObjectivesA standard treatment regimen against Mycobacteroides abscessus complex (MABC) infections has not yet been established, making MABC difficult to treat successfully. In this study, we sought to develop an active ingredient for the clinical treatment of MABC infections. MethodsWe screened 102 MABC strains isolated from clinical specimens using DNA sequence analysis with the housekeeping genes hsp65 and rpoB. Drug susceptibility testing was performed against two subspecies—Mycobacteroides abscessus subsp. abscessus (M. abscessus) and Mycobacteroides abscessus subsp. massiliense (M. massiliense)—using eight antimicrobial agents (clarithromycin, amikacin, doxycycline, imipenem, linezolid, moxifloxacin, faropenem, and rifampicin). The combined efficacy of the antimicrobial agents was investigated using a checkerboard method. ResultsWe identified 51 isolates as M. abscessus, 46 as M. massiliense, and five as others. Most of the M. abscessus isolates (83.0 %) exhibited inducible resistance to clarithromycin via the expression of the erm(41) gene. Combinations of imipenem with linezolid, moxifloxacin, and rifampicin exhibited additive effects against 81.0 %, 40.7 %, and 26.9 % of M. abscessus, respectively, and against 54.5 %, 69.2 %, and 30.8 % of M. massiliense, respectively. ConclusionsThese results demonstrated the potential efficacy of a regimen containing imipenem against M. abscessus and M. massiliense infections.

Development of a loop-mediated isothermal amplification coupled lateral flow dipstick targeting erm(41) for detection of Mycobacterium abscessus and Mycobacterium massiliense

Mycobacterium abscessus (M. abscessus) and Mycobacterium massiliense (M. massiliense) are major pathogens that cause post-surgical wound infection and chronic pulmonary disease. Although they are closely related subspecies of M. abscessus complex, their infections are associated with different drug-resistance and cure rate. In the present study, a loop-mediated isothermal amplification (LAMP) coupled with lateral flow dipstick (LFD) method was developed to simultaneous detect M. abscessus and M. massiliense, via specific erm(41) gene. The amplification was carried out at 65 °C for only 60 min, and the results could be visualized on a lateral flow strip. Positive results only occurred in M. abscessus and M. massiliense, no cross-reaction with other mycobacterial species was observed. Therefore, the cost-effective MABC (M. abscessus complex)–LAMP–LFD method developed here was able to correct the diagnose of M. abscessus and M. massiliense infection in a short time. Thus, this method could be used to guide clinicians in treatment of M. abscessus group infections.

The first reported case of pelvic inflammatory disease caused by Actinobaculum massiliense

We report the first case of pelvic inflammatory disease (PID) caused by Actinobaculum massiliense. A 53-year-old woman attended the emergency department with symptoms compatible with a PID episode, finally resolved by intramuscular antibiotic treatment. Actinobaculum sp. was isolated by culture, and A. massiliense was confirmed by matrix assisted laser desorption time-of-flight mass spectrometry and 16S rRNA gene sequencing. Only a few cases of A. massiliense infections have been reported, and the pathogenesis of infections by these bacteria is poorly understood. The introduction of new diagnostic methods into hospital routines will improve the detection of new and little-studied pathogens.

Antimicrobial and Chemotactic Activity of Scorpion-Derived Peptide, ToAP2, against Mycobacterium massiliensis.

Mycobacterium massiliense is a rapid growing, multidrug-resistant, non-tuberculous mycobacteria that is responsible for a wide spectrum of skin and soft tissue infections, as well as other organs, such as the lungs. Antimicrobial peptides had been described as broad-spectrum antimicrobial, chemotactic, and immunomodulator molecules. In this study we evaluated an antimicrobial peptide derived from scorpion Tityus obscurus as an anti-mycobacterial agent in vitro and in vivo. Bioinformatics analyses demonstrated that the peptide ToAP2 have a conserved region similar to several membrane proteins, as well as mouse cathelicidin. ToAP2 inhibited the growth of four M. massiliense strains (GO01, GO06, GO08, and CRM0020) at a minimal bactericidal concentration (MBC) of 200 µM. MBC concentration used to treat infected macrophages was able to inhibit 50% of the bacterial growth of all strains. ToAP2 treatment of infected mice with bacilli reduced the bacterial load in the liver, lung, and spleen, similarly to clarithromycin levels (90%). ToAP2 alone recruited monocytes (F4/80low Gr1), neutrophils (F4/80− Gr1), and eosinophils (F4/80+ Gr1+). ToAP2, together with M. massiliense infection, was able to increase F4/80low and reduce the percentage of F4/80high macrophages when compared with infected and untreated mice. ToAP2 has in vitro anti-microbial activity that is improved in vivo due to chemotactic activity.

Phylogenetic analysis of Mycobacterium massiliense strains having recombinant rpoB gene laterally transferred from Mycobacterium abscessus.

Recent multi locus sequence typing (MLST) and genome based studies indicate that lateral gene transfer (LGT) events in the rpoB gene are prevalent between Mycobacterium abscessus complex strains. To check the prevalence of the M. massiliense strains subject to rpoB LGT (Rec-mas), we applied rpoB typing (711 bp) to 106 Korean strains of M. massiliense infection that had already been identified by hsp65 sequence analysis (603 bp). The analysis indicated 6 smooth strains in M. massiliense Type I (10.0%, 6/60) genotypes but no strains in M. massiliense Type II genotypes (0%, 0/46), showing a discrepancy between the 2 typing methods. Further MLST analysis based on the partial sequencing of seven housekeeping genes, argH, cya, glpK, gnd, murC, pta and purH, as well as erm(41) PCR proved that these 6 Rec-mas strains consisted of two distinct genotypes belonging to M. massiliense and not M. abscessus. The complete rpoB sequencing analysis showed that these 6 Rec-mas strains have an identical hybrid rpoB gene, of which a 478 bp partial rpoB fragment may be laterally transferred from M. abscessus. Notably, five of the 6 Rec-mas strains showed complete identical sequences in a total of nine genes, including the seven MLST genes, hsp65, and rpoB, suggesting their clonal propagation in South Korea. In conclusion, we identified 6 M. massiliense smooth strains of 2 phylogenetically distinct genotypes with a specific hybrid rpoB gene laterally transferred from M. abscessus from Korean patients. Their clinical relevance and bacteriological traits remain to be elucidated.

Mycobacteriological characteristics and treatment outcomes in extrapulmonary Mycobacterium abscessus complex infections

The differentiation between Mycobacterium abscessus subspecies abscessus (M. abscessus) and Mycobacterium abscessus subspecies massiliense (M. massiliense) and determination of the presence of inducible resistance to macrolide antibiotics are important factors in the management of patients with Mycobacterium abscessus complex (MABC) infections. Unlike pulmonary MABC infections, little information on extrapulmonary MABC infections is available. The molecular identification of clinical isolates was performed, and the clinical characteristics and treatment outcomes of 20 consecutive patients with extrapulmonary MABC infections were assessed. M. abscessus and M. massiliense each caused 10 (50%) of the cases. Eight (80%) M. abscessus isolates that had inducible resistance to clarithromycin harbored an intact erm(41) gene of the T28 variant, whereas two (20%) M. abscessus isolates had the C28 erm(41) variant and were susceptible to clarithromycin. All M. massiliense isolates had a truncated erm(41) gene and were susceptible to clarithromycin. The drug susceptibility profiles other than clarithromycin were similar for the M. abscessus and M. massiliense isolates. Of the 20 patients, 17 (85%) showed a favorable outcome, including all patients with M. massiliense infection and 70% (7/10) of patients with M. abscessus infection. Favorable outcomes were associated with M. massiliense and M. abscessus isolates with a non-functional erm(41) gene (p=0.049). Precise species and subspecies identification and the determination of macrolide susceptibility are recommended for the optimal treatment of extrapulmonary MABC infections.

Clinical features and treatment outcomes of septic arthritis due to Mycobacterium massiliense associated with intra-articular injection: a case report.

BackgroundThere are increasing reports on nosocomial Mycobacterium massiliense infection, but septic arthritis and osteomyelitis because of that microorganism is rare. This report focuses on the clinical aspects of M. massiliense arthritis outbreak concurrent with soft tissue infection.Case presentationAn outbreak of septic arthritis among patients who had been injected at a single clinic occurred in South Korea between April and September 2012. This may be associated with repeated injection of triamcinolone contaminated with M. massiliense. Nine of the Korean patients visited our hospital complaining of painful swelling of the knees. During treatment course, patients are suffered from soft tissue abscess around the injection site. Acid-fast bacilli culture for infected tissue was positive in five patients, and polymerase chain reaction for non-tuberculous mycobacteria was positive in four patients. They were treated with antibiotics, repeated arthroscopic surgeries, incision and drainage for a long time. All patients were eventually cured but three patients have suffered from a decreased range of motion.ConclusionEarly clinical suspicion and microbiological diagnosis are key factors in reducing morbidity since septic arthritis with M. massiliense manifests late after the injection and treatment of it is a laborious process.

Prolonged postprocedural outbreak of Mycobacterium massiliense infections associated with ultrasound transmission gel

Postprocedural infections by Mycobacterium abscessus complex are increasing worldwide, and the source and route of transmission are infrequently identified. Here the extension of a previous clustering of paediatric patients with surgical site infections due to a single strain of the subspecies M. massiliense is reported. The investigation was conducted at a 2200-bed teaching hospital in Taiwan and included microbial surveillance of the environment (water, air, equipment and supplies) and a case–control study. We performed molecular identification and typing of the isolates by a trilocus sequencing scheme, confirmed by multilocus sequencing typing and pulsed-field gel electrophoresis. We investigated 40 patients who developed postprocedure soft tissue or bloodstream infections by M. massiliense (TPE101) during a 3-year period. Thirty-eight patients were identified at hospital A, and one newborn and her mother were identified at hospital B (185 km from hospital A). A case–control study identified the association of invasive procedures (adjusted odds ratio, 9.13) and ultrasonography (adjusted odds ratio, 2.97) (both p <0.05) with acquiring the outbreak strain. Isolates from the cases and unopened bottles of ultrasound transmission gel were all of strain ST48 and indistinguishable or closely related by pulsed-field gel electrophoresis. After replacement of contaminated gel, no new cases were detected during 18 months' follow-up. This investigation identified the use of contaminated gel as the common source causing an outbreak on a larger scale than had been recognized. Our findings halted production by the manufacturer and prompted revision of hospital guidelines.

Effect of ethyl acetate fraction of urucum extract on cell viability of peripheral blood mononuclear cells and antimicrobial activity in human pathogenic bacteria.

Effect of ethyl acetate fraction of urucum extract on cell viability of peripheral blood mononuclear cells and antimicrobial activity in human pathogenic bacteria.

Advances in the management of pulmonary disease due to Mycobacterium abscessus complex.

Mycobacterium abscessus complex is a group of rapidly growing mycobacteria, and an emerging cause of non-tuberculous mycobacterial lung disease in patients with cystic fibrosis and chronic lung diseases, such as bronchiectasis. M. abscessus complex is the most drug-resistant of the mycobacterial pathogens, resulting in limited therapeutic options and a high treatment failure rate. M. abscessus complex is comprised of three closely related subspecies: M. abscessus (sensu stricto), M. massiliense and M. bolletii. M. abscessus encodes a functional erythromycin ribosomal methylase gene, erm(41), which modifies the binding site for macrolide antibiotics, causing inducible macrolide resistance. However, this inducible macrolide resistance is not seen in M. massiliense, as the erm(41) gene of this subspecies is non-functional. Accordingly, treatment success rates with macrolide-based antibiotic treatment are much higher in patients with M. massiliense infections than in those infected with M. abscessus. Precise speciation of M. abscessus complex is important for predicting antibiotic susceptibilities and patient outcome.

Comparing Mycobacterium massiliense and Mycobacterium abscessus lung infections in cystic fibrosis patients

BackgroundMycobacterium massiliense is closely related to Mycobacterium abscessus and is also a frequent cause of mycobacterial lung disease in patients with cystic fibrosis (CF). There has been no previous investigation of possible differences between M. massiliense and M. abscessus infections in the setting of CF. MethodsWe studied a prospective cohort of 16 M. massiliense and 27 M. abscessus lung infection cases with CF, with a mean follow-up of 6years. ResultsM. massiliense cases were younger than M. abscessus cases (mean age: 12.8 vs 17.1years; p=0.02) at the time of the first mycobacterial isolation and also had lower body mass index values (mean: 16.4 vs 19.3kg/m2, p=0.002). All M. massiliense cases, except one, had negative BMI Z-score values at the time of the first mycobacterial isolation (11/12 vs 16/23 M. abscessus cases, p=0.04). Clarithromycin-based combination therapies led to mycobacterial eradication in 100% of M. massiliense cases but only in 27% of M. abscessus cases (p=0.009). ConclusionOur data show a particular link between M. massiliense and malnutrition specifically in CF patients. Unlike M. abscessus, the bacteriological response of M. massiliense to combination antibiotic therapies containing clarithromycin was excellent. Distinguishing between M. massiliense and M. abscessus has major clinical implications for CF patients.

High-level Relatedness amongMycobacterium abscessussubsp.massilienseStrains from Widely Separated Outbreaks

Three recently sequenced strains isolated from patients during an outbreak of Mycobacterium abscessus subsp. massiliense infections at a cystic fibrosis center in the United States were compared with 6 strains from an outbreak at a cystic fibrosis center in the United Kingdom and worldwide strains. Strains from the 2 cystic fibrosis outbreaks showed high-level relatedness with each other and major-level relatedness with strains that caused soft tissue infections during an epidemic in Brazil. We identified unique single-nucleotide polymorphisms in cystic fibrosis and soft tissue outbreak strains, separate single-nucleotide polymorphisms only in cystic fibrosis outbreak strains, and unique genomic traits for each subset of isolates. Our findings highlight the necessity of identifying M. abscessus to the subspecies level and screening all cystic fibrosis isolates for relatedness to these outbreak strains. We propose 2 diagnostic strategies that use partial sequencing of rpoB and secA1 genes and a multilocus sequence typing protocol.

A Case of Skin and Soft Tissue Infection byMycobacterium massiliense

Mycobacterium massiliense (M. massiliense) was identified recently as a species that separated from M. abscessus. Unlike M. abscessus, M. massiliense responds well to clarithromycin-based antibiotic treatment. Many cases of M. massiliense infections related to iatrogenic procedures have been reported. We report a case of skin and soft tissue infection by M. massiliense, which was not caused by medical appliances, that was treated successfully using clarithromycin monotherapy for -6 months after initial treatment with empirical antibiotics for 4 weeks. (Korean J Med 2014;87:510-513)