Adherence and biofilm formation of Mycobacterium avium ,Mycobacterium intracellulare and Mycobacterium abscessus to household plumbing materials

2013 ◽  
Vol 115 (3) ◽  
pp. 908-914 ◽  
Author(s):  
S.N. Mullis ◽  
J.O. Falkinham
Keyword(s):  
Mycobacterium Avium ◽  
Biofilm Formation ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Intracellulare

scholarly journals Association between 16S rRNA gene mutations and susceptibility to amikacin in Mycobacterium avium Complex and Mycobacterium abscessus clinical isolates

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Su-Young Kim ◽  
Dae Hun Kim ◽  
Seong Mi Moon ◽  
Ju Yeun Song ◽  
Hee Jae Huh ◽  
...  
Keyword(s):  
16S Rrna ◽  
16S Rrna Gene ◽  
Mycobacterium Avium ◽  
Inhibitory Concentration ◽  
Gene Mutations ◽  
Mycobacterium Abscessus ◽  
Clinical Isolates ◽  
Rrna Gene ◽  
High Level ◽  
Culture Conversion

AbstractWe evaluated the association between 16S rRNA gene (rrs) mutations and susceptibility in clinical isolates of amikacin-resistant nontuberculous mycobacteria (NTM) in NTM-pulmonary disease (PD) patients. Susceptibility was retested for 134 amikacin-resistant isolates (minimum inhibitory concentration [MIC] ≥ 64 µg/ml) from 86 patients. Amikacin resistance was reconfirmed in 102 NTM isolates from 62 patients with either Mycobacterium avium complex-PD (MAC-PD) (n = 54) or M. abscessus-PD (n = 8). MICs and rrs mutations were evaluated for 318 single colonies from these isolates. For the 54 MAC-PD patients, rrs mutations were present in 34 isolates (63%), comprising all 31 isolates with amikacin MICs ≥ 128 µg/ml, but only three of 23 isolates with an MIC = 64 µg/ml. For the eight M. abscessus-PD patients, all amikacin-resistant (MIC ≥ 64 µg/ml) isolates had rrs mutations. In amikacin-resistant isolates, the A1408G mutation (n = 29) was most common. Two novel mutations, C1496T and T1498A, were also identified. The culture conversion rate did not differ by amikacin MIC. Overall, all high-level and 13% (3/23) of low-level amikacin-resistant MAC isolates had rrs mutations whereas mutations were present in all amikacin-resistant M. abscessus isolates. These findings are valuable for managing MAC- and M. abscessus-PD and suggest the importance of phenotypic and genotypic susceptibility testing.

scholarly journals Autoinducer-2 Triggers the Oxidative Stress Response in Mycobacterium avium, Leading to Biofilm Formation

2008 ◽  
Vol 74 (6) ◽  
pp. 1798-1804 ◽  
Author(s):  
Henriette Geier ◽  
Serge Mostowy ◽  
Gerard A. Cangelosi ◽  
Marcel A. Behr ◽  
Timothy E. Ford
Keyword(s):  
Oxidative Stress ◽  
Stress Response ◽  
Quorum Sensing ◽  
Mycobacterium Avium ◽  
Biofilm Formation ◽  
Transcriptional Response ◽  
Opportunistic Pathogen ◽  
Environmental Stresses ◽  
Oxidative Stress Response ◽  
Autoinducer 2

ABSTRACT Mycobacterium avium is an environmental organism and opportunistic pathogen with inherent resistance to drugs, environmental stresses, and the host immune response. To adapt to these disparate conditions, M. avium must control its transcriptional response to environmental cues. M. avium forms biofilms in various environmental settings, including drinking water pipes and potable water reservoirs. In this study, we investigated the role of the universal signaling molecule autoinducer-2 (AI-2) in biofilm formation by M. avium. The addition of the compound to planktonic M. avium cultures resulted in increased biofilm formation. Microarray and reverse transcriptase PCR studies revealed an upregulation of the oxidative stress response upon addition of AI-2. This suggests that the response to AI-2 might be related to oxidative stress, rather than quorum sensing. Consistent with this model, addition of hydrogen peroxide, a known stimulus of the oxidative stress response, to M. avium cultures resulted in elevated biofilm formation. These results suggest that AI-2 does not act as a quorum-sensing signal in M. avium. Instead, biofilm formation is triggered by environmental stresses of biotic and abiotic origins and AI-2 may exert effects on that level.

scholarly journals Factors Influencing the Chlorine Susceptibility of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum

2003 ◽  
Vol 69 (9) ◽  
pp. 5685-5689 ◽  
Author(s):  
Joseph O. Falkinham
Keyword(s):  
Growth Rate ◽  
Mycobacterium Avium ◽  
Growth Phase ◽  
Growth Rates ◽  
Growth Stage ◽  
Tween 80 ◽  
Culture Conditions ◽  
C Cells ◽  
Mycobacterium Intracellulare ◽  
Factors Influencing

ABSTRACT The susceptibility of representative strains of Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium scrofulaceum (the MAIS group) to chlorine was studied to identify factors related to culture conditions and growth phase that influenced susceptibility. M. avium and M. intracellulare strains were more resistant to chlorine than were strains of M. scrofulaceum. Transparent and unpigmented colony variants were more resistant to chlorine than were their isogenic opaque and pigmented variants (respectively). Depending on growth stage and growth rate, MAIS strains differed in their chlorine susceptibilities. Cells from strains of all three species growing in early log phase at the highest growth rates were more susceptible than cells in log and stationary phase. Rapidly growing cells were more susceptible to chlorine than slowly growing cells. The chlorine susceptibility of M. avium cells grown at 30°C was increased when cells were exposed to chlorine at 40°C compared to susceptibility after exposure at 30°C. Cells of M. avium grown in 6% oxygen were significantly more chlorine susceptible than cells grown in air. Chlorine-resistant MAIS strains were more hydrophobic and resistant to Tween 80, para-nitrobenzoate, hydroxylamine, and nitrite than were the chlorine-sensitive strains.

scholarly journals Effective Treatment of Mycobacterium avium subsp. hominissuis and Mycobacterium abscessus Species Infections in Macrophages, Biofilm, and Mice by Using Liposomal Ciprofloxacin

2018 ◽  
Vol 62 (10) ◽  
Author(s):  
James D. Blanchard ◽  
Valerie Elias ◽  
David Cipolla ◽  
Igor Gonda ◽  
Luiz E. Bermudez
Keyword(s):  
Effective Treatment ◽  
Mouse Models ◽  
Mycobacterium Avium ◽  
Nontuberculous Mycobacteria ◽  
Mycobacterium Abscessus ◽  
Content Type ◽  
Number Of Individuals ◽  
Intranasal Instillation

ABSTRACT Nontuberculous mycobacteria (NTM) affect an increasing number of individuals worldwide. Infection with these organisms is more common in patients with chronic lung conditions, and treatment is challenging. Quinolones, such as ciprofloxacin, have been used to treat patients, but the results have not been encouraging. In this report, we evaluate novel formulations of liposome-encapsulated ciprofloxacin (liposomal ciprofloxacin) in vitro and in vivo. Its efficacy against Mycobacterium avium and Mycobacterium abscessus was examined in macrophages, in biofilms, and in vivo using intranasal instillation mouse models. Liposomal ciprofloxacin was significantly more active than free ciprofloxacin against both pathogens in macrophages and biofilms. When evaluated in vivo, treatment with the liposomal ciprofloxacin formulations was associated with significant decreases in the bacterial loads in the lungs of animals infected with M. avium and M. abscessus. In summary, topical delivery of liposomal ciprofloxacin in the lung at concentrations greater than those achieved in the serum can be effective in the treatment of NTM, and further evaluation is warranted.

Mycobacterium Avium And Mycobacterium Intracellulare: Distinct Pathogens Or Just A “complex”?

2010 ◽  
Author(s):  
Matthew J. Heffer ◽  
Fahad Al-Ghimlas ◽  
Victor Hoffstein ◽  
Frances Jamieson ◽  
Mauli Mehta ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Intracellulare

In Vitro Efficacy of Free and Nanoparticle Formulations of Gallium(III) meso-Tetraphenylporphyrine against Mycobacterium avium and Mycobacterium abscessus and Gallium Biodistribution in Mice

2018 ◽  
Vol 15 (3) ◽  
pp. 1215-1225 ◽  
Author(s):  
Seoung-ryoung Choi ◽  
Bradley E. Britigan ◽  
Barbara Switzer ◽  
Traci Hoke ◽  
David Moran ◽  
...  
Keyword(s):  
Mycobacterium Avium ◽  
Mycobacterium Abscessus
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