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SUMMARYThis guidance presents recommendations for clinical microbiology laboratories for processing respiratory samples from people with cystic fibrosis (pwCF). Appropriate processing of respiratory samples is crucial to detect bacterial and fungal pathogens, guide treatment, monitor the epidemiology of cystic fibrosis (CF) pathogens, and assess therapeutic interventions. Thanks to CF transmembrane conductance regulator modulator therapy, the health of pwCF has improved, but as a result, fewer pwCF spontaneously expectorate sputum. Thus, the collection of sputum samples has decreased, while the collection of other types of respiratory samples such as oropharyngeal and bronchoalveolar lavage samples has increased. To optimize the detection of microorganisms, including Pseudomonas aeruginosa, Staphylococcus aureus, Haemophilus influenzae, and Burkholderia cepacia complex; other less common non-lactose fermenting Gram-negative bacilli, e.g., Stenotrophomonas maltophilia, Inquilinus, Achromobacter, Ralstonia, and Pandoraea species; and yeasts and filamentous fungi, non-selective and selective culture media are recommended for all types of respiratory samples, including samples obtained from pwCF after lung transplantation. There are no consensus recommendations for laboratory practices to detect, characterize, and report small colony variants (SCVs) of S. aureus, although studies are ongoing to address the potential clinical impact of SCVs. Accurate identification of less common Gram-negative bacilli, e.g., S. maltophilia, Inquilinus, Achromobacter, Ralstonia, and Pandoraea species, as well as yeasts and filamentous fungi, is recommended to understand their epidemiology and clinical importance in pwCF. However, conventional biochemical tests and automated platforms may not accurately identify CF pathogens. MALDI-TOF MS provides excellent genus-level identification, but databases may lack representation of CF pathogens to the species-level. Thus, DNA sequence analysis should be routinely available to laboratories for selected clinical circumstances. Antimicrobial susceptibility testing (AST) is not recommended for every routine surveillance culture obtained from pwCF, although selective AST may be helpful, e.g., for unusual pathogens or exacerbations unresponsive to initial therapy. While this guidance reflects current care paradigms for pwCF, recommendations will continue to evolve as CF research expands the evidence base for laboratory practices.
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Although acute melioidosis is the most common outcome of Burkholderia pseudomallei infection, we have documented a case, P314, where disease severity lessened with time, and the pathogen evolved towards a commensal relationship with the host. In the current study, we used whole-genome sequencing to monitor this long-term symbiotic relationship to better understand B. pseudomallei persistence in P314's sputum despite intensive initial therapeutic regimens. We collected and sequenced 118 B. pseudomallei isolates from P314's airways over a >16-year period, and also sampled the patient's home environment, recovering six closely related B. pseudomallei isolates from the household water system. Using comparative genomics, we identified 126 SNPs in the core genome of the 124 isolates or 162 SNPs/indels when the accessory genome was included. The core SNPs were used to construct a phylogenetic tree, which demonstrated a close relationship between environmental and clinical isolates and detailed within-host evolutionary patterns. The phylogeny had little homoplasy, consistent with a strictly clonal mode of genetic inheritance. Repeated sampling revealed evidence of genetic diversification, but frequent extinctions left only one successful lineage through the first four years and two lineages after that. Overall, the evolution of this population is nonadaptive and best explained by genetic drift. However, some genetic and phenotypic changes are consistent with in situ adaptation. Using a mouse model, P314 isolates caused greatly reduced morbidity and mortality compared to the environmental isolates. Additionally, potentially adaptive phenotypes emerged and included differences in the O-antigen, capsular polysaccharide, motility, and colony morphology. The >13-year co-existence of two long-lived lineages presents interesting hypotheses that can be tested in future studies to provide additional insights into selective pressures, niche differentiation, and microbial adaptation. This unusual melioidosis case presents a rare example of the evolutionary progression towards commensalism by a highly virulent pathogen within a single human host.
Assuntos
Burkholderia pseudomallei/fisiologia , Melioidose/microbiologia , Animais , Antibacterianos/administração & dosagem , Evolução Biológica , Burkholderia pseudomallei/classificação , Burkholderia pseudomallei/genética , Burkholderia pseudomallei/isolamento & purificação , Doença Crônica/terapia , Feminino , Genoma Bacteriano , Humanos , Estudos Longitudinais , Melioidose/tratamento farmacológico , Camundongos , Camundongos Endogâmicos BALB C , Pessoa de Meia-Idade , Filogenia , SimbioseRESUMO
Antimicrobial-resistant ESKAPE ( Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) pathogens represent a global threat to human health. The acquisition of antimicrobial resistance genes by ESKAPE pathogens has reduced the treatment options for serious infections, increased the burden of disease, and increased death rates due to treatment failure and requires a coordinated global response for antimicrobial resistance surveillance. This looming health threat has restimulated interest in the development of new antimicrobial therapies, has demanded the need for better patient care, and has facilitated heightened governance over stewardship practices.
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Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Bactérias/genética , Infecções Bacterianas/tratamento farmacológico , Descoberta de Drogas , Farmacorresistência Bacteriana Múltipla , Infecções Bacterianas/microbiologia , HumanosRESUMO
Achromobacter is a genus of nonfermenting Gram-negative bacteria under order Burkholderiales Although primarily isolated from respiratory tract of people with cystic fibrosis, Achromobacter spp. can cause a broad range of infections in hosts with other underlying conditions. Their rare occurrence and ever-changing taxonomy hinder defining their clinical features, risk factors for acquisition and adverse outcomes, and optimal treatment. Achromobacter spp. are intrinsically resistant to several antibiotics (e.g., most cephalosporins, aztreonam, and aminoglycosides), and are increasingly acquiring resistance to carbapenems. Carbapenem resistance is mainly caused by multidrug efflux pumps and metallo-ß-lactamases, which are not expected to be overcome by new ß-lactamase inhibitors. Among the other new antibiotics, cefiderocol, and eravacycline were used as salvage therapy for a limited number of patients with Achromobacter infections. In this article, we aim to give an overview of the antimicrobial resistance in Achromobacter species, highlighting the possible place of new antibiotics in their treatment.
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Achromobacter , Infecções por Bactérias Gram-Negativas , Achromobacter/genética , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Carbapenêmicos/farmacologia , Farmacorresistência Bacteriana Múltipla , Bactérias Gram-Negativas , Infecções por Bactérias Gram-Negativas/tratamento farmacológico , HumanosRESUMO
Acinetobacter baumannii causes a wide range of nosocomial infections. This pathogen is considered a threat to human health due to the increasingly frequent isolation of multidrug-resistant strains. There is a major gap in knowledge on the infection biology of A. baumannii, and only a few virulence factors have been characterized, including lipopolysaccharide. The lipid A expressed by A. baumannii is hepta-acylated and contains 2-hydroxylaurate. The late acyltransferases controlling the acylation of lipid A have been already characterized. Here, we report the characterization of A. baumannii LpxO, which encodes the enzyme responsible for the 2-hydroxylation of lipid A. By genetic methods and mass spectrometry, we demonstrate that LpxO catalyzes the 2-hydroxylation of the laurate transferred by A. baumannii LpxL. LpxO-dependent lipid A 2-hydroxylation protects A. baumannii from polymyxin B, colistin, and human ß-defensin 3. LpxO contributes to the survival of A. baumannii in human whole blood and is required for pathogen survival in the waxmoth Galleria mellonella LpxO also protects Acinetobacter from G. mellonella antimicrobial peptides and limits their expression. Further demonstrating the importance of LpxO-dependent modification in immune evasion, 2-hydroxylation of lipid A limits the activation of the mitogen-activated protein kinase Jun N-terminal protein kinase to attenuate inflammatory responses. In addition, LpxO-controlled lipid A modification mediates the production of the anti-inflammatory cytokine interleukin-10 (IL-10) via the activation of the transcriptional factor CREB. IL-10 in turn limits the production of inflammatory cytokines following A. baumannii infection. Altogether, our studies suggest that LpxO is a candidate for the development of anti-A. baumannii drugs.
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Infecções por Acinetobacter/microbiologia , Acinetobacter baumannii/metabolismo , Acinetobacter baumannii/patogenicidade , Lipídeo A/metabolismo , Acinetobacter baumannii/genética , Acinetobacter baumannii/crescimento & desenvolvimento , Aciltransferases/genética , Aciltransferases/metabolismo , Animais , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Hidroxilação , Larva/microbiologia , Lipídeo A/química , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mariposas/microbiologia , VirulênciaRESUMO
Median cystic fibrosis (CF) survival has increased dramatically over time due to several factors, including greater availability and use of antimicrobial therapies. During the progression of CF lung disease, however, the emergence of multidrug antimicrobial resistance can limit treatment effectiveness, threatening patient longevity. Current planktonic-based antimicrobial susceptibility testing lacks the ability to predict clinical response to antimicrobial treatment of chronic CF lung infections. There are numerous reasons for these limitations including bacterial phenotypic and genotypic diversity, polymicrobial interactions, and impaired antibiotic efficacy within the CF lung environment. The parallels to other chronic diseases such as non-CF bronchiectasis are discussed as well as research priorities for moving forward.
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Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Fibrose Cística/tratamento farmacológico , Infecções por Pseudomonas/tratamento farmacológico , Doença Crônica/tratamento farmacológico , Fibrose Cística/microbiologia , Humanos , Pulmão/efeitos dos fármacos , Pulmão/microbiologia , Testes de Sensibilidade Microbiana , Pseudomonas aeruginosa/efeitos dos fármacos , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Escarro/microbiologiaRESUMO
The airborne route is a potential pathway in the person-to-person transmission of bacterial strains among cystic fibrosis (CF) populations. In this cross-sectional study, we investigate the physical properties and survival of common non-Pseudomonas aeruginosa CF pathogens generated during coughing. We conclude that Gram-negative bacteria and Staphylococcus aureus are aerosolised during coughing, can travel up to 4 m and remain viable within droplet nuclei for up to 45 min. These results suggest that airborne person-to-person transmission is plausible for the CF pathogens we measured.
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Fibrose Cística/microbiologia , Infecções por Bactérias Gram-Negativas/transmissão , Infecções Estafilocócicas/transmissão , Staphylococcus aureus/crescimento & desenvolvimento , Achromobacter/isolamento & purificação , Adulto , Aerossóis , Burkholderia/isolamento & purificação , Contagem de Colônia Microbiana , Tosse/microbiologia , Estudos Transversais , Feminino , Infecções por Bactérias Gram-Negativas/microbiologia , Humanos , Masculino , Infecções por Pseudomonas/transmissão , Pseudomonas aeruginosa/crescimento & desenvolvimento , Escarro/microbiologia , Staphylococcus aureus/isolamento & purificação , Stenotrophomonas maltophilia/isolamento & purificação , Fatores de Tempo , Adulto JovemRESUMO
BACKGROUND AND OBJECTIVE: Aerosol transmission of Pseudomonas aeruginosa has been suggested as a possible mode of respiratory infection spread in patients with cystic fibrosis (CF); however, whether this occurs in other suppurative lung diseases is unknown. Therefore, we aimed to determine if (i) patients with bronchiectasis (unrelated to CF) or chronic obstructive pulmonary disease (COPD) can aerosolize P. aeruginosa during coughing and (ii) if genetically indistinguishable (shared) P. aeruginosa strains are present in these disease cohorts. METHODS: People with bronchiectasis or COPD and P. aeruginosa respiratory infection were recruited for two studies. Aerosol study: Participants (n = 20) underwent cough testing using validated cough rigs to determine the survival of P. aeruginosa aerosols in the air over distance and duration. Genotyping study: P. aeruginosa sputum isolates (n = 95) were genotyped using the iPLEX20SNP platform, with a subset subjected to the enterobacterial repetitive intergenic consensus polymerase chain reaction (ERIC-PCR) assay to ascertain their genetic relatedness. RESULTS: Aerosol study: Overall, 7 of 20 (35%) participants released P. aeruginosa cough aerosols during at least one of the cough aerosol tests. These cough aerosols remained viable for 4 m from the source and for 15 min after coughing. The mean total aerosol count of P. aeruginosa at 2 m was two colony-forming units. Typing study: No shared P. aeruginosa strains were identified. CONCLUSION: Low viable count of P. aeruginosa cough aerosols and a lack of shared P. aeruginosa strains observed suggest that aerosol transmission of P. aeruginosa is an unlikely mode of respiratory infection spread in patients with bronchiectasis and COPD.
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Aerossóis , Bronquiectasia/complicações , Tosse/microbiologia , Infecções por Pseudomonas/complicações , Pseudomonas aeruginosa , Doença Pulmonar Obstrutiva Crônica/complicações , Idoso , Contagem de Colônia Microbiana , Tosse/etiologia , Feminino , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Filogenia , Pseudomonas aeruginosa/genética , Pseudomonas aeruginosa/isolamento & purificação , Escarro/microbiologiaRESUMO
RATIONALE: People with cystic fibrosis (CF) generate Pseudomonas aeruginosa in droplet nuclei during coughing. The use of surgical masks has been recommended in healthcare settings to minimize pathogen transmission between patients with CF. OBJECTIVES: To determine if face masks and cough etiquette reduce viable P. aeruginosa aerosolized during coughing. METHODS: Twenty-five adults with CF and chronic P. aeruginosa infection were recruited. Participants performed six talking and coughing maneuvers, with or without face masks (surgical and N95) and hand covering the mouth when coughing (cough etiquette) in an aerosol-sampling device. An Andersen Cascade Impactor was used to sample the aerosol at 2 meters from each participant. Quantitative sputum and aerosol bacterial cultures were performed, and participants rated the mask comfort levels during the cough maneuvers. MEASUREMENTS AND MAIN RESULTS: During uncovered coughing (reference maneuver), 19 of 25 (76%) participants produced aerosols containing P. aeruginosa, with a positive correlation found between sputum P. aeruginosa concentration (measured as cfu/ml) and aerosol P. aeruginosa colony-forming units. There was a reduction in aerosol P. aeruginosa load during coughing with a surgical mask, coughing with an N95 mask, and cough etiquette compared with uncovered coughing (P < 0.001). A similar reduction in total colony-forming units was observed for both masks during coughing; yet, participants rated the surgical masks as more comfortable (P = 0.013). Cough etiquette provided approximately half the reduction of viable aerosols of the mask interventions during voluntary coughing. Talking was a low viable aerosol-producing activity. CONCLUSIONS: Face masks reduce cough-generated P. aeruginosa aerosols, with the surgical mask providing enhanced comfort. Cough etiquette was less effective at reducing viable aerosols.
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Tosse/microbiologia , Fibrose Cística/microbiologia , Exposição por Inalação/prevenção & controle , Máscaras , Infecções por Pseudomonas/prevenção & controle , Pseudomonas aeruginosa/isolamento & purificação , Adulto , Austrália , Estudos de Coortes , Transmissão de Doença Infecciosa/prevenção & controle , Feminino , Humanos , Masculino , Infecções por Pseudomonas/transmissão , Valores de ReferênciaRESUMO
BACKGROUND: Chronic lung infections caused by Pseudomonas aeruginosa are a significant cause of morbidity and mortality in people with cystic fibrosis (CF). Shared P. aeruginosa strains, that can be transmitted between patients, are of concern and in Australia the AUST-02 shared strain is predominant in individuals attending CF centres in Queensland and Western Australia. M3L7 is a multidrug resistant sub-type of AUST-02 that was recently identified in a Queensland CF centre and was shown to be associated with poorer clinical outcomes. The main aim of this study was to resolve the relationship of the emergent M3L7 sub-type within the AUST-02 group of strains using whole genome sequencing. RESULTS: A whole genome core phylogeny of 63 isolates indicated that M3L7 is a monophyletic sub-lineage within the context of the broader AUST-02 group. Relatively short branch lengths connected all of the M3L7 isolates. A phylogeny based on nucleotide polymorphisms present across the genome showed that the chronological estimation of the most recent common ancestor was around 2001 (± 3 years). SNP differences between sequential non-hypermutator M3L7 isolates collected 3-4 years apart from five patients suggested both continuous infection of the same strain and cross-infection of some M3L7 variants between patients. The majority of polymorphisms that were characteristic of M3L7 (i.e. acquired after divergence from all other AUST-02 isolates sequenced) were found to produce non-synonymous mutations in virulence and antibiotic resistance genes. CONCLUSIONS: M3L7 has recently diverged from a common ancestor, indicating descent from a single carrier at a CF treatment centre in Australia. Both adaptation to the lung and transmission of M3L7 between adults attending this centre may have contributed to its rapid dissemination. Further genomic investigations are required on multiple intra-sample isolates of this sub-type to decipher potential mechanisms which facilitates its epidemiological success.
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Fibrose Cística/complicações , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/transmissão , Pseudomonas aeruginosa/classificação , Pseudomonas aeruginosa/isolamento & purificação , Adulto , Fibrose Cística/microbiologia , Variação Genética , Genótipo , Humanos , Filogenia , Pseudomonas aeruginosa/genética , Sequenciamento Completo do GenomaRESUMO
The lungs of individuals with cystic fibrosis (CF) become chronically infected with Pseudomonas aeruginosa that is difficult to eradicate by antibiotic treatment. Two key P. aeruginosa antibiotic resistance mechanisms are the AmpC ß-lactamase that degrades ß-lactam antibiotics and MexXYOprM, a three-protein efflux pump that expels aminoglycoside antibiotics from the bacterial cells. Levels of antibiotic resistance gene expression are likely to be a key factor in antibiotic resistance but have not been determined during infection. The aims of this research were to investigate the expression of the ampC and mexX genes during infection in patients with CF and in bacteria isolated from the same patients and grown under laboratory conditions. P. aeruginosa isolates from 36 CF patients were grown in laboratory culture and gene expression measured by reverse transcription-quantitative PCR (RT-qPCR). The expression of ampC varied over 20,000-fold and that of mexX over 2,000-fold between isolates. The median expression levels of both genes were increased by the presence of subinhibitory concentrations of antibiotics. To measure P. aeruginosa gene expression during infection, we carried out RT-qPCR using RNA extracted from fresh sputum samples obtained from 31 patients. The expression of ampC varied over 4,000-fold, while mexX expression varied over 100-fold, between patients. Despite these wide variations, median levels of expression of ampC in bacteria in sputum were similar to those in laboratory-grown bacteria. The expression of mexX was higher in sputum than in laboratory-grown bacteria. Overall, our data demonstrate that genes that contribute to antibiotic resistance can be highly expressed in patients, but there is extensive isolate-to-isolate and patient-to-patient variation.
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Fibrose Cística/microbiologia , Resistência Microbiana a Medicamentos/genética , Pseudomonas aeruginosa/genética , Adolescente , Adulto , Aminoglicosídeos/farmacologia , Antibacterianos/farmacologia , Proteínas de Bactérias/genética , Criança , Fibrose Cística/tratamento farmacológico , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana/métodos , Pessoa de Meia-Idade , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/efeitos dos fármacos , Escarro/microbiologia , Adulto Jovem , beta-Lactamases/genéticaRESUMO
Infection is a common complication of cystic fibrosis (CF) airway disease. Current treatment approaches include early intervention with the intent to eradicate pathogens in the hope of delaying the development of chronic infection and the chronic use of aerosolized antibiotics to suppress infection. The use of molecules that help restore CFTR (cystic fibrosis transmembrane conductance regulator) function, modulate pulmonary inflammation, or improve pulmonary clearance may also influence the microbial communities in the airways. As the pipeline of these new entities continues to expand, it is important to define when key pathogens are eradicated from the lungs of CF patients and, equally important, when new pathogens might emerge as a result of these novel therapies.
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Antibacterianos/uso terapêutico , Bactérias/efeitos dos fármacos , Bactérias/isolamento & purificação , Fibrose Cística/tratamento farmacológico , Fibrose Cística/microbiologia , Antibacterianos/farmacologia , Bactérias/crescimento & desenvolvimento , Doença Crônica/prevenção & controle , Fibrose Cística/complicações , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Humanos , Pulmão/microbiologia , Pulmão/patologia , Infecções Respiratórias/complicações , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologiaRESUMO
BACKGROUND: Pulmonary exacerbations in cystic fibrosis (CF) remain poorly understood and treatment is usually targeted at Pseudomonas aeruginosa. Within Australia a predominant shared P. aeruginosa strain (AUST-02) is associated with greater treatment needs. This single centre study assessed temporal shared strain population dynamics during and after antibiotic treatment of exacerbations. METHODS: Sputum was collected from 12 adult patients with a history of chronic AUST-02 infection at four time-points during and after treatment of an exacerbation. Forty-eight P. aeruginosa isolates within each sample underwent AUST-02 allele-specific PCR and SNP-based strain genotyping. RESULTS: Various commonly shared Australian strains (AUST-01, 0.1%; AUST-02, 54.3%; AUST-06, 36.6%; AUST-07, 4.6%; AUST-11, 4.3%) and two unique strains (0.1%) were identified from 45 sputum samples (2160 isolates). Based on within-patient relative abundance of strains, a "single-strain infection" (n = 7) or "mixed-strain infection" (n = 5) was assigned to each patient. A significant temporal variation in the P. aeruginosa population composition was found for those with mixed-strain infection (P < 0.001). Patients with mixed-strain infections had more long-term treatment requirements than those with single-strain infection. Moreover, despite both groups having similar lung function at study entry, patients with single-strain infection had greater improvement in FEV1% predicted following their exacerbation treatment (P = 0.02). CONCLUSION: Pulmonary exacerbations may reveal multiple, unrelated P. aeruginosa strains whose relative abundance with one another may change rapidly, in a sustained and unpredictable manner.
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Antibacterianos/uso terapêutico , Fibrose Cística/complicações , Infecções por Pseudomonas/tratamento farmacológico , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/genética , Infecções Respiratórias/tratamento farmacológico , Infecções Respiratórias/microbiologia , Adulto , Progressão da Doença , Feminino , Volume Expiratório Forçado , Genótipo , Humanos , Masculino , Pessoa de Meia-Idade , Fenótipo , Dinâmica Populacional , Infecções por Pseudomonas/fisiopatologia , Pseudomonas aeruginosa/isolamento & purificação , Infecções Respiratórias/fisiopatologia , Escarro/microbiologia , Fatores de TempoRESUMO
BACKGROUND AND OBJECTIVE: In cystic fibrosis (CF), chronic Pseudomonas aeruginosa infection is associated with increased morbidity, antibiotic treatments and mortality. By linking Australian CF registry data with a national microbiological data set, we examined the association between where treatment was delivered, its intensity and P. aeruginosa antibiotic resistance. METHODS: Sputa were collected from paediatric and adult CF patients attending 18 Australian CF centres. P. aeruginosa antibiotic susceptibilities determined by local laboratories were correlated with clinical characteristics, treatment intensity and infection with strains commonly shared among Australian CF patients. Between-centre differences in treatment and antibiotic resistance were also compared. RESULTS: Large variations in antibiotic usage, maintenance treatment practices and multi-antibiotic resistant P. aeruginosa (MARPA) prevalence exist between Australian CF centres, although the overall proportions of MARPA isolates were similar in paediatric and adult centres (31% vs 35%, P = 0.29). Among paediatric centres, MARPA correlated with intravenous antibiotic usage and the Australian state where treatment was delivered, while azithromycin, reduced lung function and treating state predicted intravenous antibiotic usage. In adult centres, body mass index (BMI) and treating state were associated with MARPA, while intravenous antibiotic use was predicted by gender, BMI, dornase-alpha, azithromycin, lung function and treating state. In adults, P. aeruginosa strains AUST-01 and AUST-02 independently predicted intravenous antibiotic usage. CONCLUSION: Increased treatment intensity in paediatric centres and the Australian state where treatment was received are both associated with greater risk of MARPA, but not worse clinical outcomes.
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Antibacterianos/uso terapêutico , Fibrose Cística/complicações , Farmacorresistência Bacteriana Múltipla , Instalações de Saúde , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/efeitos dos fármacos , Administração Intravenosa , Adulto , Antibacterianos/administração & dosagem , Austrália , Azitromicina/uso terapêutico , Índice de Massa Corporal , Criança , Fibrose Cística/fisiopatologia , Uso de Medicamentos , Feminino , Humanos , Masculino , Testes de Sensibilidade Microbiana , Padrões de Prática Médica , Sistema de Registros , Testes de Função Respiratória , Fatores Sexuais , Escarro/microbiologiaRESUMO
BACKGROUND: People with cystic fibrosis (CF) may work in healthcare settings risking nosocomial pathogen acquisition. The aim of this study was to determine the incidence of methicillin-resistant Staphylococcus aureus (MRSA) infection in adult healthcare workers with CF (HCWcf). METHODS: Data was collected in this observational study on MRSA acquisition from 405 CF patients attending an adult CF centre in Australia between 2001-2012. Demographic and clinical characteristics were compared between HCWcf and non-HCWcf. A sub-analysis was subsequently performed to compare demographic and clinical characteristics between those patients (HCWcf versus non-HCWcf) that acquired MRSA. We also investigated rates of chronic MRSA infection and the outcome of eradication treatment in HCWcf. RESULTS: A higher proportion of HCWcf acquired MRSA [n = 10/21] compared to non-HCWcf [n = 40/255] (P <0.001). The odds of MRSA acquisition were 8.4 (95 % CI, 3.0 - 23.4) times greater in HCWcf than non-HCWcf. HCWcf with MRSA were older (P = 0.02) and had better lung function (P = 0.009), yet hospitalisation rates were similar compared to non-HCWcf with MRSA. Chronic MRSA infection developed in 36/50 CF patients (HCWcf, n = 6; non-HCWcf, n = 30), with eradication therapy achieved in 5/6 (83 %) HCWcf. CONCLUSIONS: The rate of MRSA incidence was highest in HCWcf and the workplace is a possible source of acquisition. Vocational guidance should include the potential for MRSA acquisition for CF patients considering healthcare professions.
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Infecção Hospitalar/tratamento farmacológico , Infecção Hospitalar/epidemiologia , Fibrose Cística/complicações , Pessoal de Saúde , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Infecções Estafilocócicas/tratamento farmacológico , Infecções Estafilocócicas/epidemiologia , Adulto , Antibacterianos/uso terapêutico , Austrália , Estudos Transversais , Feminino , Ácido Fusídico/uso terapêutico , Humanos , Incidência , Linezolida/uso terapêutico , Modelos Logísticos , Masculino , Análise Multivariada , Estudos Retrospectivos , Rifampina/uso terapêutico , Resultado do Tratamento , Adulto JovemRESUMO
Nine Burkholderia cepacia complex (Bcc) bacteria were isolated during environmental surveys for the ecological niche of Burkholderia pseudomallei, the aetiological agent of melioidosis, in the Northern Territory of Australia. They represented two multi-locus sequence analysis-based clusters, referred to as Bcc B and Bcc L. Three additional environmental and clinical Bcc B isolates were identified upon deposition of the sequences in the PubMLST database. Analysis of the concatenated nucleotide sequence divergence levels within both groups (1.4 and 1.9%, respectively) and towards established Bcc species (4.0 and 3.9%, respectively) demonstrated that the two taxa represented novel Bcc species. All 12 isolates were further characterized using 16S rRNA and recA gene sequence analysis, RAPD analysis, DNA base content determination, fatty acid methyl ester analysis and biochemical profiling. Analysis of recA gene sequences revealed a remarkable diversity within each of these taxa, but, together, the results supported the affiliation of the two taxa to the Bcc. Bcc B strains can be differentiated from most other Bcc members by the assimilation of maltose. Bcc L strains can be differentiated from other Bcc members by the absence of assimilation of N-acetylglucosamine. The names Burkholderia stagnalis sp. nov. with type strain LMG 28156(T) ( = CCUG 65686(T)) and Burkholderia territorii sp. nov. with type strain LMG 28158(T) ( = CCUG 65687(T)) are proposed for Bcc B and Bcc L bacteria, respectively.
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Complexo Burkholderia cepacia/classificação , Filogenia , Técnicas de Tipagem Bacteriana , Composição de Bases , Complexo Burkholderia cepacia/genética , Complexo Burkholderia cepacia/isolamento & purificação , DNA Bacteriano/genética , Ácidos Graxos/química , Genes Bacterianos , Humanos , Dados de Sequência Molecular , Tipagem de Sequências Multilocus , Northern Territory , RNA Ribossômico 16S/genética , Técnica de Amplificação ao Acaso de DNA Polimórfico , Análise de Sequência de DNA , Microbiologia do Solo , Escarro/microbiologia , Microbiologia da ÁguaRESUMO
BACKGROUND: Several cases of Burkholderia pseudomallei infection in CF have been previously reported. We aimed to identify all cases globally, risk factors for acquisition, clinical consequences, and optimal treatment strategies. METHODS: We performed a literature search to identify all published cases of B. pseudomallei infection in CF. In addition we hand-searched respiratory journals, and contacted experts in infectious diseases and CF around the world. Supervising clinicians for identified cases were contacted and contemporaneous clinical data was requested. RESULTS: 25 culture-confirmed cases were identified. The median age at acquisition was 21 years, mean FEV1 % predicted was 60 %, and mean BMI was 19.5 kg/m(2). The location of acquisition was northern Australia or south-east Asia for most. 19 patients (76 %) developed chronic infection, which was usually associated with clinical decline. Successful eradication strategies included a minimum of two weeks of intravenous ceftazidime, followed by a consolidation phase with trimethoprim/sulfamethoxazole, and this resulted in a higher chance of success when instituted early. Three cases of lung transplantation have been recorded in the setting of chronic B. pseudomallei infection. CONCLUSION: Chronic carriage of B. pseudomallei in patients with CF appears common after infection, in contrast to the non-CF population. This is often associated with an accelerated clinical decline. Lung transplantation has been performed in select cases of chronic B. pseudomallei infection.
Assuntos
Burkholderia pseudomallei , Fibrose Cística/epidemiologia , Melioidose/epidemiologia , Adolescente , Adulto , Antibacterianos/uso terapêutico , Australásia/epidemiologia , Ceftazidima/uso terapêutico , Criança , Fibrose Cística/fisiopatologia , Europa (Continente)/epidemiologia , Feminino , Volume Expiratório Forçado , Humanos , Masculino , Melioidose/tratamento farmacológico , América do Norte/epidemiologia , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: Person-to-person transmission of respiratory pathogens, including Pseudomonas aeruginosa, is a challenge facing many cystic fibrosis (CF) centres. Viable P aeruginosa are contained in aerosols produced during coughing, raising the possibility of airborne transmission. METHODS: Using purpose-built equipment, we measured viable P aeruginosa in cough aerosols at 1, 2 and 4 m from the subject (distance) and after allowing aerosols to age for 5, 15 and 45 min in a slowly rotating drum to minimise gravitational settling and inertial impaction (duration). Aerosol particles were captured and sized employing an Anderson Impactor and cultured using conventional microbiology. Sputum was also cultured and lung function and respiratory muscle strength measured. RESULTS: Nineteen patients with CF, mean age 25.8 (SD 9.2) years, chronically infected with P aeruginosa, and 10 healthy controls, 26.5 (8.7) years, participated. Viable P aeruginosa were detected in cough aerosols from all patients with CF, but not from controls; travelling 4 m in 17/18 (94%) and persisting for 45 min in 14/18 (78%) of the CF group. Marked inter-subject heterogeneity of P aeruginosa aerosol colony counts was seen and correlated strongly (r=0.73-0.90) with sputum bacterial loads. Modelling decay of viable P aeruginosa in a clinic room suggested that at the recommended ventilation rate of two air changes per hour almost 50 min were required for 90% to be removed after an infected patient left the room. CONCLUSIONS: Viable P aeruginosa in cough aerosols travel further and last longer than recognised previously, providing additional evidence of airborne transmission between patients with CF.
Assuntos
Tosse/microbiologia , Fibrose Cística/microbiologia , Infecções por Pseudomonas/microbiologia , Infecções por Pseudomonas/transmissão , Pseudomonas aeruginosa/isolamento & purificação , Adolescente , Adulto , Aerossóis , Estudos de Casos e Controles , Feminino , Humanos , Exposição por Inalação , Masculino , Testes de Função Respiratória , Escarro/microbiologiaRESUMO
BACKGROUND: Molecular typing is integral for identifying Pseudomonas aeruginosa strains that may be shared between patients with cystic fibrosis (CF). We conducted a side-by-side comparison of two P. aeruginosa genotyping methods utilising informative-single nucleotide polymorphism (SNP) methods; one targeting 10 P. aeruginosa SNPs and using real-time polymerase chain reaction technology (HRM10SNP) and the other targeting 20 SNPs and based on the Sequenom MassARRAY platform (iPLEX20SNP). METHODS: An in-silico analysis of the 20 SNPs used for the iPLEX20SNP method was initially conducted using sequence type (ST) data on the P. aeruginosa PubMLST website. A total of 506 clinical isolates collected from patients attending 11 CF centres throughout Australia were then tested by both the HRM10SNP and iPLEX20SNP assays. Type-ability and discriminatory power of the methods, as well as their ability to identify commonly shared P. aeruginosa strains, were compared. RESULTS: The in-silico analyses showed that the 1401 STs available on the PubMLST website could be divided into 927 different 20-SNP profiles (D-value = 0.999), and that most STs of national or international importance in CF could be distinguished either individually or as belonging to closely related single- or double-locus variant groups. When applied to the 506 clinical isolates, the iPLEX20SNP provided better discrimination over the HRM10SNP method with 147 different 20-SNP and 92 different 10-SNP profiles observed, respectively. For detecting the three most commonly shared Australian P. aeruginosa strains AUST-01, AUST-02 and AUST-06, the two methods were in agreement for 80/81 (98.8%), 48/49 (97.8%) and 11/12 (91.7%) isolates, respectively. CONCLUSIONS: The iPLEX20SNP is a superior new method for broader SNP-based MLST-style investigations of P. aeruginosa. However, because of convenience and availability, the HRM10SNP method remains better suited for clinical microbiology laboratories that only utilise real-time PCR technology and where the main interest is detection of the most highly-prevalent P. aeruginosa CF strains within Australian clinics.