Mycobacterium avium subsp. hominissuis (MAH) Microaggregate induction of host innate immunity is linked to biofilm formation

Keefe, Bailey F.; Leestemaker-Palmer, Amy; Bermudez, Luiz E.

doi:10.1016/j.micpath.2021.104977

Cited by 5 publications

(7 citation statements)

References 37 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In vitro experiments have shown that microaggregates, the precursors to sessile bacteria in biofilms, can induce phenotype switching, increase early biofilm production, and are more prone to be phagocytosed 22 . The distinction between microaggregate and sessile phenotypes has not been fully characterized, however, so for the sake of simplicity we consider only one sessile phenotype.…”

Section: Sessile Bacteriamentioning

confidence: 99%

See 1 more Smart Citation

The Role of Biofilms, Bacterial Phenotypes, and Innate Immune Response in Mycobacterium avium Colonization to Infection

Weathered

Pennington

Escalante

et al. 2022

Journal of Theoretical Biology

View full text Add to dashboard Cite

Section: Sessile Bacteriamentioning

confidence: 99%

“…In the absence of biofilms, macrophages are known to phagocytose MAC 21 , but phagocytosis is also affected by biofilms. Mature biofilms can prevent phagocytosis 19 , but phenotypic precursors to biofilms, known as microaggregates, have been shown to increase phagocytosis 22 .…”

Section: Introductionmentioning

confidence: 99%

The Role of Biofilms, Bacterial Phenotypes, and Innate Immune Response in Mycobacterium avium Colonization to Infection

Weathered

Pennington

Escalante

et al. 2022

Journal of Theoretical Biology

View full text Add to dashboard Cite

“…Many of these infections (especially lung ones) have been considered as biofilm-related ones. The ability to develop biofilms by these mycobacteria was proved several years ago, and this property is now considered an essential pathogenic factor for these infections [11,[21][22][23]. Moreover, because sessile bacteria appear to be more resistant to antibiotics than planktonic ones, therapy for these patients must be influenced by this finding [24], and prolonged treatment with a combination of different antimicrobials is mandatory.…”

Section: Discussionmentioning

confidence: 99%

“…These infections are currently considered biofilm-related infections, and this fact is of clinical importance because of the higher resistance against antibiotics of sessile bacteria compared with planktonic ones. However, despite these facts, there are only a few in vitro studies regarding biofilm formation by MAC [7][8][9][10][11][12], and most of them used only collection strains. Here we report a study about biofilm formation by the three most important species of MAC and the effect of clarithromycin, an antibiotic commonly used in these infections, on them, using not only collection strains but also clinical isolates of all of them.…”

Section: Introductionmentioning

confidence: 99%

Biofilm Development by Mycobacterium avium Complex Clinical Isolates: Effect of Clarithromycin in Ultrastructure

Akir,

Senhaji-Kacha,

Muñoz-Egea

et al. 2024

Antibiotics

View full text Add to dashboard Cite

Background: The Mycobacterium avium complex includes the commonest non-tuberculous mycobacteria associated with human infections. These infections have been associated with the production of biofilms in many cases, but there are only a few studies about biofilms produced by the species included in this group. Methods: Three collection strains (M. avium ATCC25291, M. intracellulare ATCC13950, and M. chimaera DSM756), three clinically significant strains (647, 657, and 655), and three clinically non-significant ones (717, 505, and 575) of each species were included. The clinical significance of the clinical isolates was established according to the internationally accepted criteria. The biofilm ultrastructure was studied by Confocal-Laser Scanning Microscopy by using BacLight Live–Dead and Nile Red stains. The viability, covered surface, height, and relative autofluorescence were measured in several images/strain. The effect of clarithromycin was studied by using the technique described by Muñoz-Egea et al. with modifications regarding incubation time. The study included clarithromycin in the culture medium at a concentration achievable in the lungs (11.3 mg/L), using one row of wells as the control without antibiotics. The bacterial viability inside the biofilm is expressed as a percentage of viable cells. The differences between the different parameters of the biofilm ultrastructure were analyzed by using the Kruskal–Wallis test. The correlation between bacterial viability in the biofilm and treatment time was evaluated by using Spearman’s rank correlation coefficient (ρ). Results: The strains showed differences between them with all the studied parameters, but neither a species-specific pattern nor a clinical-significance-specific pattern were detected. For the effect of clarithromycin, the viability of the bacteria contained in the biofilm was inversely proportional to the exposure time of the biofilm (ρ > −0.3; p-value < 0.05), excluding two M. chimaera strains (M. chimaera DSM756 and 575), which showed a weak positive correlation with treatment time (0.2 < ρ < 0.39; p-value < 0.05). Curiously, despite a clarithromycin treatment of 216 h, the percentage of the biofilm viability of the strains evaluated here was not less than 40% at best (M. avium 717). Conclusions: All the M. avium complex strains studied can form biofilm in vitro, but the ultrastructural characteristics between them suggest that these are strain-specific characteristics unrelated to the species or the clinical significance. The clarithromycin effect on MAC species is biofilm-age/time-of-treatment-dependent and appears to be strain-specific while being independent of the clinical significance of the strain.

show abstract

“…It has also been shown that peripheral blood mononuclear cells (PBMCs) from patients with NTMPD produced lower levels of IFNγ and TNFα compared to those of healthy controls [27,28]. Finally, human genetics studies have revealed that toll-like receptor (TLR) signaling, and innate immunity are necessary to combat disseminated NTM [29][30][31][32][33][34].…”

Section: Introductionmentioning

confidence: 99%

Impact of aging on the immunological and microbial landscape of the lung during non-tuberculous mycobacterial infection

Cinco¹,

Rhoades²,

Napier³

et al. 2023

Preprint

View full text Add to dashboard Cite

Nontuberculous mycobacteria (NTM) are environmentally ubiquitous and predominately cause pulmonary disease (NTMPD). The incidence of NTMPD has steadily increased and is now more prevalent than that of Mycobacterium tuberculosis (M. tb) in the US. Moreover, the prevalence of NTMPD increases with age; therefore, it is likely that the burden of NTMPD will continue to increase in the coming decades as the number of those over the age of 65 increased in the U.S population. However, the mechanisms leading to higher susceptibility and severity of NTMPD with aging are poorly defined. Here, we used a rhesus macaque model of intrabronchial infection with M. avium complex in young and aged animals to address this knowledge gap. Unilateral infection resulted in a robust inflammatory response predominantly in the inoculated lung, however, immune cell infiltration and antigen-specific T cell responses were detected in both lungs. Nasal, oral, and fecal swabs, and BAL samples were profiled using 16S amplicon sequencing. These data suggested that decompartmentalization of the lower respiratory microbiome was occurring, evidenced by detection of bacterial DNA typically found in the gut and oral-pharyngeal cavity in bronchoalveolar samples following infection. Radiographic studies, gross pathology, and histopathology examination revealed increased disease severity in aged compared to young animals with pulmonary consolidation, edema, and lesions. Finally, single cell RNA sequencing indicated that aged animals generated a dysregulated macrophage and CD8 T cell response to MAC infection.

show abstract

Mycobacterium avium subsp. hominissuis (MAH) Microaggregate induction of host innate immunity is linked to biofilm formation

Cited by 5 publications

References 37 publications

The Role of Biofilms, Bacterial Phenotypes, and Innate Immune Response in Mycobacterium avium Colonization to Infection

The Role of Biofilms, Bacterial Phenotypes, and Innate Immune Response in Mycobacterium avium Colonization to Infection

Biofilm Development by Mycobacterium avium Complex Clinical Isolates: Effect of Clarithromycin in Ultrastructure

Impact of aging on the immunological and microbial landscape of the lung during non-tuberculous mycobacterial infection

Contact Info

Product

Resources

About