Effect of Coptis chinensis on Biofilm Formation and Antibiotic Susceptibility in Mycobacterium abscessus

Mycobacterium abscessus infections are notoriously difficult to be treated and newer treatment options are required. Coptis chinensis (C. chinensis) and its main compound berberine are frequently used to treat bacterial and viral infections. In this study, the susceptibility of M. abscessus to C. chinensis extract and berberine was assessed by minimal inhibitory concentration (MIC) and minimal bactericidal concentration (MBC) evaluation. The effects of C. chinensis and berberine on biofilm formation and antibiotic susceptibility in M. abscessus were observed. C. chinensis at concentrations of MIC (1.5 mg/mL) and 2 × MIC (3.0 mg/mL) and berberine at ½ × MIC (0.125 mg/mL) demonstrated a strong inhibition of biofilm formation. Concentration of C. chinensis at ½ × MIC resulted in a significant reduction in MICs of trimethoprim/sulfamethoxazole (TMP/SXT), clarithromycin (CLA), and linezolid (LZD). Similarly, ½ × MIC berberine had a significant effect on the MIC reductions of nine antibiotics including TMP/SXT, CLA, and LZD. Notably, the resistance level MIC of LZD against M. abscessus was reversed to a susceptible level by treatment with either C. chinensis or berberine. Therefore, C. chinensis and berberine have the potential to produce a synergistic antimycobacterial effect, reduce biofilm formation, and decrease antibacterial resistance to LZD in M. abscessus.

Non-pigmented rapidly growing mycobacteria smooth and rough colony phenotypes pathogenicity evaluated using in vitro and experimental models

Non-pigmented rapidly growing mycobacteria (NPRGM) are widely distributed in water, soil and animals. It has been observed an increasing importance of NPRGM related-infections, particularly due to the high antimicrobial resistance. NPRGM have rough and smooth colony phenotypes, and several studies have showed that rough colony variants are more virulent than smooth ones. However, other studies have failed to validate this observation. In this study, we have performed two models, invitro and in vivo, in order to assess the different pathogenicity of these two phenotypes. We used collection and clinical strains of Mycobacteriumabscessus, Mycobacterium fortuitum and Mycobacteriumchelonae. On the invitro model (macrophages), phagocytosis was higher for M. abscessus and M. fortuitum rough colony variant strains when compared to smooth colony variants. However, we did not find differences with colonial variants of M. chelonae. Survival of Galleriamellonella larvae in the experimental model was lower for M. abscessus and M. fortuitum rough colony variants when compared with larvae infected with smooth colony variants. We did not find differences in larvae infected with M. chelonae.Results of our in vivo study correlated well with the experimental model. This fact could have implications on the interpretation of the clinical significance of the NPRGM isolate colonial variants.

Historical evolution of the diseases caused by non-pigmented rapidly growing mycobacteria in a University Hospital

OBJECTIVE

Non-pigmented rapidly growing mycobacteria (NPRGM) are a group of organisms of increasing interest due to the growing number of potential patients and the difficulties for a proper treatment in many of them. However, the evolution of these diseases in a long period of time and its evolutionary changes has been described only in a scanty number of reports.

METHODS

We performed a retrospective study between January 1st 2004 and December 31st 2017 in order to evaluate the clinical significance and types of diseases caused by NPRGM. Patients with isolates of NPRGM during this period were selected for the study, and clinical charts were reviewed using a predefined protocol.

RESULTS

During this period we identified 59 patients (76 clinical samples) with isolates of NPRGM, with 12 cases of clinical disease and one patient with doubtful significance (including 6 respiratory tract infections, 2 catheter infections, 1 skin and soft tissue infection, 1 disseminated infection, 1 conjunctivitis, 1 prosthetic joint infection and 1 mastitis). Fifty percent of M. chelonae isolates, 37.5% of M. abscessus isolates and 23.33% of M. fortuitum isolates were clinically significant. None of the isolates of other species were significant.

CONCLUSIONS

Most isolates in respiratory samples were contaminants/colonizations. M. abscessus was the main etiological agent in respiratory syndromes, whereas M. chelonae and M. fortuitum were more frequently associated with other infections, especially clinical devices and skin and soft tissue infections.

To bee or not to bee: The potential efficacy and safety of bee venom acupuncture in humans

Bee venom acupuncture is a form of acupuncture in which bee venom is applied to the tips of acupuncture needles, stingers are extracted from bees, or bees are held with an instrument exposing the stinger, and applied to acupoints on the skin. Bee venom is a complex substance consisting of multiple anti-inflammatory compounds such as melittin, adolapin, apamin. Other substances such as phospholipase A2 can be anti-inflammatory in low concentrations and pro-inflammatory in others. However, bee venom also contains proinflammatory substances, melittin, mast cell degranulation peptide 401, and histamine. Nevertheless, in small studies, bee venom acupuncture has been used in man to successfully treat a number of musculoskeletal diseases such as lumbar disc disease, osteoarthritis of the knee, rheumatoid arthritis, adhesive capsulitis, and lateral epicondylitis. Bee venom acupuncture can also alleviate neurological conditions, including peripheral neuropathies, stroke and Parkinson's Disease. The treatment has even been piloted in one series to alleviate depression. An important concern is the safety of bee venom. Bee venom can cause anaphylaxis, and several deaths have been reported in patients who successfully received the therapy prior to the adverse event. While the incidence of adverse events is unknown, the number of published reports of toxicity is small. Refining bee venom to remove harmful substances may potentially limit its toxicity. New uses for bee venom acupuncture may also be considered.

Mycobacterium chelonae hand infection after steroid injection in a patient with rheumatoid arthritis receiving long-term linezolid therapy

A 66-year-old multimorbid man with rheumatoid arthritis developed an infection after a steroid injection in the hand. Mycobacterium chelonae was cultured 1-month after presentation. In the mean time, his third finger had been amputated. Further treatment was based on preliminary susceptibility testing and the American Thoracic Society guidelines. No regression of the infection was observed before the addition of linezolid (600 mg×1/day) to a combination antimicrobial therapy also consisting of clarithromycin (500 mg×2/day) and moxifloxacin (400 mg×1/day), even though two methods of susceptibility testing, the E-test and broth microdilution, had shown susceptibility to other antimicrobial drugs. The healing was complete 12 months after presentation. There were no serious side effects observed with the use of linezolid in reduced dosage of 600 mg×1/day for a duration of 9 months.

Mycobacterium fortuitum skin infections after subcutaneous injections with Vietnamese traditional medicine: a case report

Background

Iatrogenic skin and soft tissue infections by rapidly growing mycobacteria are described with increasing frequency, especially among immunocompromised patients.

Case presentation

Here, we present an immunocompetent patient with extensive Mycobacterium fortuitum skin and soft tissue infections after subcutaneous injections to relieve joint pains by a Vietnamese traditional medicine practitioner. Moreover, we present dilemmas faced in less resourceful settings, influencing patient management.

Conclusion

This case illustrates the pathogenic potential of rapid growing mycobacteria in medical or non-medical skin penetrating procedures, their world-wide distribution and demonstrates the dilemmas faced in settings with fewer resources.

Electronic supplementary material

The online version of this article (doi:10.1186/s12879-014-0550-z) contains supplementary material, which is available to authorized users.