scholarly journals Stepwise pathogenic evolution of Mycobacterium abscessus

Science ◽  
2021 ◽  
Vol 372 (6541) ◽  
pp. eabb8699
Author(s):  
Josephine M. Bryant ◽  
Karen P. Brown ◽  
Sophie Burbaud ◽  
Isobel Everall ◽  
Juan M. Belardinelli ◽  
...  
Keyword(s):  
Parallel Evolution ◽  
Mycobacterium Abscessus ◽  
Human Infection ◽  
Pathogenic Potential ◽  
Cystic Fibrosis Population ◽  
Recent Emergence ◽  
Almost All ◽  
Chronic Lung Infection ◽  
Pathogenic Evolution ◽  
Key Interventions

Although almost all mycobacterial species are saprophytic environmental organisms, a few, such as Mycobacterium tuberculosis, have evolved to cause transmissible human infection. By analyzing the recent emergence and spread of the environmental organism M. abscessus through the global cystic fibrosis population, we have defined key, generalizable steps involved in the pathogenic evolution of mycobacteria. We show that epigenetic modifiers, acquired through horizontal gene transfer, cause saltational increases in the pathogenic potential of specific environmental clones. Allopatric parallel evolution during chronic lung infection then promotes rapid increases in virulence through mutations in a discrete gene network; these mutations enhance growth within macrophages but impair fomite survival. As a consequence, we observe constrained pathogenic evolution while person-to-person transmission remains indirect, but postulate accelerated pathogenic adaptation once direct transmission is possible, as observed for M. tuberculosis. Our findings indicate how key interventions, such as early treatment and cross-infection control, might restrict the spread of existing mycobacterial pathogens and prevent new, emergent ones.

scholarly journals Moraxella catarrhalis: from Emerging to Established Pathogen

2002 ◽  
Vol 15 (1) ◽  
pp. 125-144 ◽  
Author(s):  
Cees M. Verduin ◽  
Cees Hol ◽  
André Fleer ◽  
Hans van Dijk ◽  
Alex van Belkum
Keyword(s):  
Moraxella Catarrhalis ◽  
Current Knowledge ◽  
Bacterial Species ◽  
Bacterial Pathogen ◽  
Diagnostic Techniques ◽  
Human Infection ◽  
Molecular Diagnostic ◽  
Molecular Diagnostic Techniques ◽  
Pathogenic Potential ◽  
The Past

SUMMARY Moraxella catarrhalis (formerly known as Branhamella catarrhalis) has emerged as a significant bacterial pathogen of humans over the past two decades. During this period, microbiological and molecular diagnostic techniques have been developed and improved for M. catarrhalis, allowing the adequate determination and taxonomic positioning of this pathogen. Over the same period, studies have revealed its involvement in respiratory (e.g., sinusitis, otitis media, bronchitis, and pneumonia) and ocular infections in children and in laryngitis, bronchitis, and pneumonia in adults. The development of (molecular) epidemiological tools has enabled the national and international distribution of M. catarrhalis strains to be established, and has allowed the monitoring of nosocomial infections and the dynamics of carriage. Indeed, such monitoring has revealed an increasing number of Β-lactamase-positive M. catarrhalis isolates (now well above 90%), underscoring the pathogenic potential of this organism. Although a number of putative M. catarrhalis virulence factors have been identified and described in detail, their relationship to actual bacterial adhesion, invasion, complement resistance, etc. (and ultimately their role in infection and immunity), has been established in a only few cases. In the past 10 years, various animal models for the study of M. catarrhalis pathogenicity have been described, although not all of these models are equally suitable for the study of human infection. Techniques involving the molecular manipulation of M. catarrhalis genes and antigens are also advancing our knowledge of the host response to and pathogenesis of this bacterial species in humans, as well as providing insights into possible vaccine candidates. This review aims to outline our current knowledge of M. catarrhalis, an organism that has evolved from an emerging to a well-established human pathogen.

scholarly journals Dog ownership, dog behaviour and transmission of Echinococcus spp. in the Alay Valley, southern Kyrgyzstan

Parasitology ◽  
2013 ◽  
Vol 140 (13) ◽  
pp. 1674-1684 ◽  
Author(s):  
FREYA VAN KESTEREN ◽  
ALEXANDER MASTIN ◽  
BERMET MYTYNOVA ◽  
ISKENDER ZIADINOV ◽  
BELGEES BOUFANA ◽  
...  
Keyword(s):  
Soviet Union ◽  
Rural Communities ◽  
Environmental Contamination ◽  
Human Infection ◽  
Domestic Dogs ◽  
Dog Ownership ◽  
The Soviet Union ◽  
Almost All ◽  
First Time ◽  
Echinococcus Spp

SUMMARYEchinococcosis is a re-emerging zoonotic disease in Kyrgyzstan, and the incidence of human infection has increased substantially since the collapse of the Soviet Union in 1991. Domestic dogs are hosts of Echinococcus spp. and play an important role in the transmission of these parasites. The demography, ecology and behaviour of dogs are therefore relevant in studying Echinococcus spp. transmission. Dog demographics, roles of dogs, dog movements and faecal environmental contamination were assessed in four rural communities in the Alay Valley, southern Kyrgyzstan. Arecoline purge data revealed for the first time that E. granulosus, E. canadensis and E. multilocularis were present in domestic dogs in the Alay Valley. Surveys revealed that many households had dogs and that dogs played various roles in the communities, as pets, guard dogs or sheep dogs. Almost all dogs were free to roam, and GPS data revealed that many moved outside their communities, thus being able to scavenge offal and consume rodents. Faecal environmental contamination was high, presenting a significant infection risk to the local communities.

scholarly journals Recommendations to improve physical activity prescription for the cystic fibrosis population: an Irish perspective

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Nicola Hurley ◽  
Bróna Kehoe ◽  
Noel McCaffrey ◽  
Karen Redmond ◽  
Lydia Cullen ◽  
...  
Keyword(s):  
Physical Activity ◽  
Cystic Fibrosis ◽  
Online Survey ◽  
Continuing Professional Development ◽  
Therapeutic Modality ◽  
Plain Language ◽  
Patient Centered ◽  
Cystic Fibrosis Population ◽  
Almost All

Abstract Background Physical activity (PA) is a well-established therapeutic modality for the maintenance and improvement of long-term health in cystic fibrosis (CF). Healthcare professionals (HCP) are considered credible and well-placed messengers for the delivery of PA advice. Limited research exists investigating the extent of PA prescription within CF care. This study aimed to identify Irish HCP i) knowledge and practice of, and ii) motivators and barriers to PA prescription, and iii) proposed strategies to optimize PA promotion and prescription in CF populations. Methods HCP from six designated CF centres in Ireland and members of the national physiotherapy CF clinical interest group were invited to participate. Following an expression of interest, each HCP (n = 81) received an email containing the plain language statement and link to the online survey. 48 HCP (physiotherapists n = 24, other n = 24) completed the 30-item investigator-developed survey, which included multiple choice single answer, matrix style and open-ended questions. Results Most HCP (81%) acknowledged that discussing PA with CF patients was part of their professional role. Almost all physiotherapists (95%) reported having sufficient knowledge regarding PA prescription, compared to 17% of other HCP. All physiotherapists reported discussing PA at every patient interaction, with 81% employing the current consensus guidelines, compared to 33 and 5% of other HCP, respectively. Among the most common barriers reported by HCP to recommending PA to their CF patients were; lack of motivation and compliance among patients to adhere to PA advice, limited availability of PA programmes to refer their patients to, limited time with patients during clinic visits and a lack of knowledge regarding PA prescription for CF care. Three-quarters of HCP reported a need to improve PA services for CF patients in Ireland. Conclusion As people with CF are living longer, it is imperative that HCP are expanding their scope of practice to include discussions around PA at every patient visit. Formal educational opportunities in the form of continuing professional development programmes are warranted for CF HCP to optimize long-term patient management and outcomes. There is also a need to develop patient-centered and evidence-based PA programmes underpinned by theories of behaviour change to enhance motivation and compliance among CF patients.

scholarly journals P058 Prevalence of shared Mycobacterium abscessus complex (MABSC) in the Queensland cystic fibrosis population

2018 ◽  
Vol 17 ◽  
pp. S75
Author(s):  
R.E. Stockwell ◽  
L.E.X. Leong ◽  
N.E. Wheeler ◽  
J.M. Bryant ◽  
M.E. Wood ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Mycobacterium Abscessus ◽  
Mycobacterium Abscessus Complex ◽  
Cystic Fibrosis Population

Bacterial Survival on Respirator Filters and Surgical Masks

1997 ◽  
Vol 2 (3) ◽  
pp. 32-43 ◽  
Author(s):  
Lisa M. Brosseau ◽  
Nicole Vars McCullough ◽  
Donald Vesley
Keyword(s):  
Bacillus Subtilis ◽  
Staphylococcus Epidermidis ◽  
Mycobacterium Abscessus ◽  
Bacterial Survival ◽  
Risk Of Infection ◽  
Surgical Masks ◽  
Before And After ◽  
Control And Prevention ◽  
Almost All ◽  
Subtilis Subsp

The Centers for Disease Control and Prevention recently developed recommendations for respirators worn to minimize exposures to Mycobacterium tuberculosis. These recommendations include criteria for filters and facial fit, but do not address how respirators are worn or disposed of. Handling may increase the risk of infection if loaded organisms remain viable. Respirator filters were challenged with aerosols containing three bacteria: Mycobacterium abscessus, Staphylococcus epidermidis, and Bacillus subtilis subsp. niger. Elution and surface contact sampling were used to recover organisms from filters after loading and following 5 days storage at 85% RH. Almost all filters showed culturable organisms immediately after loading. After storage, filters showed the least culturability for M. abscessus (20% of all filters) followed by S. epidermidis (61%), while B. subtilis remained highly culturable (98%). A slimilar trend was seen for the number of organisms recovered before and after storage (M abscessus demonstrated the least survival and B. subtilis the most).

scholarly journals Recommendations to Improve Physical Activity Prescription for the Cystic Fibrosis Population: An Irish Perspective

2020 ◽  
Author(s):  
Nicola Hurley ◽  
Bróna Kehoe ◽  
Noel McCaffrey ◽  
Karen Redmond ◽  
Lydia Cullen ◽  
...  
Keyword(s):  
Physical Activity ◽  
Cystic Fibrosis ◽  
Online Survey ◽  
Continuing Professional Development ◽  
Therapeutic Modality ◽  
Plain Language ◽  
Patient Centered ◽  
Cystic Fibrosis Population ◽  
Almost All

Abstract Background: Physical activity (PA) is a well-established therapeutic modality for the maintenance and improvement of long-term health in cystic fibrosis (CF). Healthcare professionals (HCP) are considered credible and well-placed messengers for the delivery of PA advice. Limited research exists investigating the extent of PA prescription within CF care. This study aimed to identify Irish HCP i) knowledge and practice of, and ii) motivators and barriers to PA prescription, and iii) proposed strategies to optimize PA promotion and prescription in CF populations.Methods: HCP from six designated CF centres in Ireland and members of the national physiotherapy CF clinical interest group were invited to participate. Following an expression of interest, each HCP (n=81) received an email containing the plain language statement and link to the online survey. 48 HCP (physiotherapists n=24, other n=24) completed the 30-item investigator-developed survey, which included multiple choice single answer, matrix style and open-ended questions.Results: Most HCP (81%) acknowledged that discussing PA with CF patients was part of their professional role. Almost all physiotherapists (95%) reported having sufficient knowledge regarding PA prescription, compared to 17% of other HCP. All physiotherapists reported discussing PA at every patient interaction, with 81% employing the current consensus guidelines, compared to 33% and 5% of other HCP, respectively. Among the most common barriers reported by HCP to recommending PA to their CF patients were; lack of motivation and compliance among patients to adhere to PA advice, limited availability of PA programmes to refer their patients to, limited time with patients during clinic visits and a lack of knowledge regarding PA prescription for CF care. Three-quarters of HCP reported a need to improve PA services for CF patients in Ireland.Conclusion: As people with CF are living longer, it is imperative that HCP are expanding their scope of practice to include discussions around PA at every patient visit. Formal educational opportunities in the form of continuing professional development programmes are warranted for CF HCP to optimize long-term patient management and outcomes. There is also a need to develop patient-centered and evidence-based PA programmes underpinned by theories of behaviour change to enhance motivation and compliance among CF patients.

scholarly journals Molecular epidemiology and phylogenomic analysis of Mycobacterium abscessus clinical isolates in an Asian population

2021 ◽  
Vol 7 (11) ◽  
Author(s):  
Ka Lip Chew ◽  
Sophie Octavia ◽  
Roland Jureen ◽  
Oon Tek Ng ◽  
Kalisvar Marimuthu ◽  
...  
Keyword(s):  
Virulence Factors ◽  
Type Species ◽  
Asian Population ◽  
Bioinformatic Analysis ◽  
Mycobacterium Abscessus ◽  
Phylogenomic Analysis ◽  
Pathogenic Potential ◽  
Content Type ◽  
Link Type ◽  
Sequence Types

Mycobacterium abscessus comprises three subspecies: M. abscessus subsp. abscessus , M. abscessus subsp. bolletii , and M. abscessus subsp. massiliense . These closely related strains are typically multi-drug-resistant and can cause difficult-to-treat infections. Dominant clusters of isolates with increased pathogenic potential have been demonstrated in pulmonary infections in the global cystic fibrosis (CF) population. An investigation was performed on isolates cultured from an Asian, predominantly non-CF population to explore the phylogenomic relationships within our population and compare it to global M. abscessus isolates. Whole-genome-sequencing was performed on M. abscessus isolates between 2017 and 2019. Bioinformatic analysis was performed to determine multi-locus-sequence-type, to establish the phylogenetic relationships between isolates, and to identify virulence and resistance determinants in these isolates. A total of 210 isolates were included, of which 68.5 % (144/210) were respiratory samples. These isolates consisted of 140 (66.6 %) M . abscessus subsp. massiliense , 67 (31.9 %) M . abscessus subsp. abscessus, and three (1.4 %) M . abscessus subsp. bolletii . Dominant sequence-types in our population were similar to those of global CF isolates, but SNP differences in our population were comparatively wider despite the isolates being from the same geographical region. ESX (ESAT-6 secretory) cluster three appeared to occur most commonly in ST4 and ST6 M. abscessus subsp. massiliense , but other virulence factors did not demonstrate an association with isolate subspecies or sample source. We demonstrate that although similar predominant sequence-types are seen in our patient population, cross-transmission is absent. The risk of patient-to-patient transmission appears to be largely limited to the vulnerable CF population, indicating infection from environmental sources remains more common than human-to-human transmission. Resistance and virulence factors are largely consistent across the subspecies with the exception of clarithromycin susceptibility and ESX-3.

scholarly journals Experimental Usutu Virus Infection in Domestic Canaries Serinus canaria

Viruses ◽  
2020 ◽  
Vol 12 (2) ◽  
pp. 164 ◽  
Author(s):  
Emna Benzarti ◽  
José Rivas ◽  
Michaël Sarlet ◽  
Mathieu Franssen ◽  
Daniel Desmecht ◽  
...  
Keyword(s):  
Neurological Disease ◽  
Neurological Complications ◽  
Human Infection ◽  
Histopathological Changes ◽  
Serinus Canaria ◽  
Usutu Virus ◽  
Virus Tropism ◽  
Almost All ◽  
Different Doses

Usutu virus (USUV) is a neurotropic flavivirus closely related to West Nile virus (WNV). Its enzootic cycle mainly involves mosquitoes and birds. Human infection can occur with occasional, but sometimes severe, neurological complications. Since its emergence and spread in Europe over the last two decades, USUV has been linked to significant avian outbreaks, especially among Passeriformes, including European blackbirds (Turdus merula). Strikingly, no in vivo avian model exists so far to study this arbovirus. The domestic canary (Serinus canaria) is a passerine, which is considered as a highly susceptible model of infection by WNV. Here, we experimentally challenged domestic canaries with two different doses of USUV. All inoculated birds presented detectable amounts of viral RNA in the blood and RNA shedding via feathers and droppings during the early stages of the infection, as determined by RT-qPCR. Mortality occurred in both infected groups (1/5 and 2/5, respectively) and was not necessarily correlated to a pure neurological disease. Subsequent analyses of samples from dead birds showed histopathological changes and virus tropism mimicking those reported in naturally infected birds. A robust seroconversion followed the infection in almost all the surviving canaries. Altogether, these results demonstrate that domestic canaries constitute an interesting experimental model for the study of USUV pathogenesis and transmission.

scholarly journals Mycobacterium abscessus isolated from municipal water - a potential source of human infection

2013 ◽  
Vol 13 (1) ◽  
Author(s):  
Rachel Thomson ◽  
Carla Tolson ◽  
Hanna Sidjabat ◽  
Flavia Huygens ◽  
Megan Hargreaves
Keyword(s):  
Mycobacterium Abscessus ◽  
Human Infection ◽  
Potential Source ◽  
Municipal Water

scholarly journals Genetic diversification of persistent Mycobacterium abscessus within Cystic Fibrosis patients

2021 ◽  
Author(s):  
Astrid Lewin ◽  
Elisabeth Kamal ◽  
Torsten Semmler ◽  
Katja Winter ◽  
Sandra Kaiser ◽  
...  
Keyword(s):  
Cystic Fibrosis ◽  
Control Strategies ◽  
Cholesterol Oxidase ◽  
Treatment Strategies ◽  
Gene Mutations ◽  
Enrichment Analysis ◽  
Lung Infection ◽  
Mycobacterium Abscessus ◽  
Wide Range ◽  
Chronic Lung Infection

AbstractMycobacterium (M.) abscessus infections in Cystic Fibrosis (CF) patients cause a deterioration of lung function. Treatment of these multidrug-resistant pathogens is associated with severe side-effects, while frequently unsuccessful. Insight on M. abscessus genomic evolvement during chronic lung infection would be beneficial for improving treatment strategies. A longitudinal study enrolling 42 CF patients was performed at a CF center in Berlin, Germany, to elaborate phylogeny and genomic diversification of in-patient M. abscessus. Eleven of the 42 CF patients were infected with M. abscessus. Global human-transmissible M. abscessus cluster strains were isolated from five of these 11 patients. Phylogenetic analysis of 88 genomes from isolates of the 11 patients excluded occurrence of M. abscessus transmission among members of the study group. Genome sequencing and variant analysis of 30 isolates from 11 serial respiratory samples collected over four years from a chronically infected patient demonstrated accumulation of gene mutations. In total, 53 genes exhibiting non-synonymous variations were identified. Enrichment analysis emphasized genes involved in synthesis of glycopeptidolipids, genes from the embABC (arabinosyltransferase) operon, betA (glucose-methanol-choline oxidoreductase) and choD (cholesterol oxidase). Genetic diversity evolved in a variety of virulence- and resistance-associated genes. The strategy of M. abscessus populations in chronic lung infection is not clonal expansion of dominant variants, but to sustain simultaneously a wide range of genetic variants facilitating adaptation of the population to changing living conditions in the lung. Genomic diversification during chronic infection requires increased attention when new control strategies against M. abscessus infections are explored.

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