Laboratory Maintenance of <i>Mycobacterium abscessus</i>

Cortès, Mélanie; Nessar, Rachid; Singh, Anil Kumar

doi:10.1002/9780471729259.mc10d01s18

Cited by 18 publications

(18 citation statements)

References 28 publications

(36 reference statements)

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“…2). As per the generation time of M. abscessus (4 to 5 h for M. abscessus [25] versus 20 to 30 min for E. coli [24]), the time points at which aliquots of the liquid cultures were plated for CFU determination were adjusted to 6, 12, and 24 h. As expected, LIN and TIG showed no bactericidal activity (Fig. 2).…”

Section: Resultsmentioning

confidence: 60%

Lack of Antimicrobial Bactericidal Activity in Mycobacterium abscessus

Maurer

Bruderer

Ritter

et al. 2014

Antimicrob Agents Chemother

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bAntibiotic therapy of infections caused by the emerging pathogen Mycobacterium abscessus is challenging due to the organism's natural resistance toward most clinically available antimicrobials. We investigated the bactericidal activity of antibiotics commonly administered in M. abscessus infections in order to better understand the poor therapeutic outcome. Time-kill curves were generated for clinical M. abscessus isolates, Mycobacterium smegmatis, and Escherichia coli by using antibiotics commonly categorized as bactericidal (amikacin and moxifloxacin) or bacteriostatic (tigecycline and linezolid). In addition, the impact of aminoglycoside-modifying enzymes on the mode of action of substrate and nonsubstrate aminoglycosides was studied by using M. smegmatis as a model organism. While amikacin and moxifloxacin were bactericidal against E. coli, none of the tested compounds showed bactericidal activity against M. abscessus. Further mechanistic investigations of the mode of action of aminoglycosides in M. smegmatis revealed that the bactericidal activity of tobramycin and gentamicin was restored by disruption of the chromosomal aac(2=) gene in the mycobacterial genome. The lack of bactericidal antibiotics in currently recommended treatment regimens provides a reasonable explanation for the poor therapeutic outcome in M. abscessus infection. Our findings suggest that chromosomally encoded drug-modifying enzymes play an important role in the lack of aminoglycoside bactericidal activity against rapidly growing mycobacteria.

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Section: Resultsmentioning

confidence: 60%

Lack of Antimicrobial Bactericidal Activity in Mycobacterium abscessus

Maurer

Bruderer

Ritter

et al. 2014

Antimicrob Agents Chemother

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“…The clinical strains grow better in Middlebrook 7H9 broth supplemented with 10% (vol/vol) oleic acid-albumin-dextrose-catalase (OADC) enrichment ( Fig. S1B), a liquid laboratory medium for culturing mycobacteria (26)(27)(28). Therefore, Middlebrook 7H9 liquid medium was primarily used in this study.…”

Section: Resultsmentioning

confidence: 99%

“…S1; Table S3). Due to concerns that the inherent instability of ␤-lactams may lead to artificially high MIC values after such prolonged incubation periods (8,(23)(24)(25)(26)(27)(28), we relied primarily on Middlebrook 7H9 liquid medium for the broth MIC assays in this study. However, we also evaluated a selection of carbapenems and cephalosporins in CAMHB and found that, in general, the MICs were indeed higher in CAMHB than Middlebrook 7H9 medium (Tables 2 and S4).…”

Section: Discussionmentioning

confidence: 99%

In Vitro Activity of the New β-Lactamase Inhibitors Relebactam and Vaborbactam in Combination with β-Lactams against Mycobacterium abscessus Complex Clinical Isolates

Kaushik

Ammerman

Liu

et al. 2019

Antimicrob Agents Chemother

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Pulmonary disease due to infection withMycobacterium abscessuscomplex (MABC) is notoriously difficult to treat, in large part due to the intrinsic resistance of MABC strains to most antibiotics, including β-lactams. MABC organisms express a broad-spectrum β-lactamase that is resistant to traditional β-lactam-based β-lactamase inhibitors but inhibited by a newer non-β-lactam-based β-lactamase inhibitor, avibactam. Consequently, the susceptibility of MABC members to some β-lactams is increased in the presence of avibactam. Therefore, we hypothesized that two new non-β-lactam-based β-lactamase inhibitors, relebactam and vaborbactam, would also increase the susceptibility of MABC organisms to β-lactams. The objective of the present study was to evaluate thein vitroactivity of various marketed β-lactams alone and in combination with either relebactam or vaborbactam against multidrug-resistant MABC clinical isolates. Our data demonstrate that both β-lactamase inhibitors significantly improved the anti-MABC activity of many carbapenems (including imipenem and meropenem) and cephalosporins (including cefepime, ceftaroline, and cefuroxime). As a meropenem-vaborbactam combination is now marketed and an imipenem-relebactam combination is currently in phase III trials, these fixed combinations may become the β-lactams of choice for the treatment of MABC infections. Furthermore, given the evolving interest in dual β-lactam regimens, our results identify select cephalosporins, such as cefuroxime, with superior activity in the presence of a β-lactamase inhibitor that are deserving of further evaluation in combination with these carbapenem–β-lactamase inhibitor products.

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“…The fact that the disinfector was fully loaded might have influenced our results, but it probably mimics reality more precisely. For safety reasons, we did all mycobacterial testing in a BSL-3 Lab in a safety cabinet Class II, which meant we were limited to two steam disinfectors and disposable test tubes instead of nebulizer parts [43]. Finally, some materials are not heat-resistant enough for steam disinfection; therefore, all manufacturers of nebulizers or airway clearance devices should declare if steam disinfection is possible and choose materials suitable for steam disinfection.…”

Section: Discussionmentioning

confidence: 99%