RESUMEN
Little is known about oxygen utilization during infection by bacterial respiratory pathogens. The classical Bordetella species, including B. pertussis, the causal agent of human whooping cough, and B. bronchiseptica, which infects nearly all mammals, are obligate aerobes that use only oxygen as the terminal electron acceptor for electron transport-coupled oxidative phosphorylation. B. bronchiseptica, which occupies many niches, has eight distinct cytochrome oxidase-encoding loci, while B. pertussis, which evolved from a B. bronchiseptica-like ancestor but now survives exclusively in and between human respiratory tracts, has only three functional cytochrome oxidase-encoding loci: cydAB1, ctaCDFGE1, and cyoABCD1. To test the hypothesis that the three cytochrome oxidases encoded within the B. pertussis genome represent the minimum number and class of cytochrome oxidase required for respiratory infection, we compared B. bronchiseptica strains lacking one or more of the eight possible cytochrome oxidases in vitro and in vivo. No individual cytochrome oxidase was required for growth in ambient air, and all three of the cytochrome oxidases conserved in B. pertussis were sufficient for growth in ambient air and low oxygen. Using a high-dose, large-volume persistence model and a low-dose, small-volume establishment of infection model, we found that B. bronchiseptica producing only the three B. pertussis-conserved cytochrome oxidases was indistinguishable from the wild-type strain for infection. We also determined that CyoABCD1 is sufficient to cause the same level of bacterial burden in mice as the wild-type strain and is thus the primary cytochrome oxidase required for murine infection, and that CydAB1 and CtaCDFGE1 fulfill auxiliary roles or are important for aspects of infection we have not assessed, such as transmission. Our results shed light on the environment at the surface of the ciliated epithelium, respiration requirements for bacteria that colonize the respiratory tract, and the evolution of virulence in bacterial pathogens.
Asunto(s)
Infecciones por Bordetella , Complejo IV de Transporte de Electrones , Animales , Ratones , Complejo IV de Transporte de Electrones/metabolismo , Complejo IV de Transporte de Electrones/genética , Infecciones por Bordetella/microbiología , Infecciones del Sistema Respiratorio/microbiología , Bordetella bronchiseptica/genética , Bordetella bronchiseptica/metabolismo , Bordetella bronchiseptica/enzimología , Humanos , Sistema Respiratorio/microbiología , Sistema Respiratorio/metabolismo , Evolución Biológica , Bordetella/genética , Bordetella/enzimología , Bordetella pertussis/genética , Bordetella pertussis/enzimología , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/genéticaRESUMEN
OBJECTIVE: To evaluate the role of Bordetella pertussis (B. pertussis), B. parapertussis, B. holmesii, and B. bronchiseptica on pertussis resurgence in China, particularly the sharp rise since the latest winter. METHODS: Nasopharyngeal swabs collected from children with pertussis-like illness from January 2018 to March 2024 were cultured to detect B. pertussis, B. parapertussis, B. holmesii, and B. bronchiseptica, and tested for all of these except for B. bronchiseptica using a pooled real-time polymerase chain reaction (PCR) kit targeting insertion sequences ptxS1, IS481, IS1001, and hIS1001. RESULTS: Out of the collected 7732 nasopharyngeal swabs, 1531 cases tested positive for B. pertussis (19.8%, 1531/7732), and 10 cases were positive for B. parapertussis (0.1%, 10/7732). B. holmesii and B.bronchiseptica were not detected. The number of specimens and the detection rate of B. pertussis were 1709 and 26.9% (459/1709) in 2018, 1936 and 20.7% (400/1936) in 2019, which sharply declined to 308 and 11.4% (35/308) in 2020, 306 and 4.2% (13/306) in 2021, and then notably increased to 754 and 17.6% (133/754) in 2022, 1842 and 16.0% (295/1842) in 2023, 877 and 22.3% (196/877) in the first quarter of 2024. The proportion of children aged 3 to less than 6 years (preschool age) and 6 to 16 years (school age) in pertussis cases increased significantly during the study period, especially the proportion of school-aged children increased from 2.0% (9/459) in 2018 to 40.8% (80/196) in 2024. CONCLUSIONS: B. pertussis was the predominant pathogen among children with pertussis-like illness in China, with sporadic detection of B. parapertussis and no detection of B. holmesii or B.bronchiseptica. The preschool and school-age children are increasingly prevalent in B. pertussis infection cases, which may be associated with the latest rapid escalation of pertussis outbreak.
Asunto(s)
Infecciones por Bordetella , Bordetella , Nasofaringe , Tos Ferina , Humanos , China/epidemiología , Preescolar , Niño , Lactante , Masculino , Femenino , Tos Ferina/epidemiología , Tos Ferina/diagnóstico , Tos Ferina/microbiología , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/epidemiología , Infecciones por Bordetella/diagnóstico , Nasofaringe/microbiología , Bordetella/aislamiento & purificación , Bordetella/genética , Bordetella/clasificación , Bordetella pertussis/genética , Bordetella pertussis/aislamiento & purificación , Adolescente , Bordetella parapertussis/aislamiento & purificación , Bordetella parapertussis/genética , Reacción en Cadena en Tiempo Real de la PolimerasaRESUMEN
In the United States, the general laboratory method for diagnosing pertussis, caused by Bordetella pertussis, is real-time PCR (rt-PCR) targeting insertion sequence 481 (IS481). Other Bordetella species (parapertussis, holmesii, and bronchiseptica) can also cause a pertussis-like syndrome, and some commercial laboratory assays include the insertion sequence 1001 (pIS1001) that can detect B. parapertussis/B. bronchiseptica (BppBb). Because IS481 exists in B. pertussis and B. holmesii, current commercial assays cannot differentiate these two species. We used a multiplex rt-PCR assay containing species-specific targets to Bordetella to evaluate clinical specimens detected as B. pertussis/B. holmesii (BpBh) or BppBb by commercial laboratories. A sample of 3,984 clinical specimens positive for IS481 or pIS1001 from two commercial laboratories during 2012-2019 were re-tested at CDC. Agreement of Bordetella species between the CDC and commercial laboratory assays, and the proportion of commercial laboratory specimens that were non-B. pertussis by CDC's assay was assessed. Overall agreement in Bordetella species detection and identification between the CDC and commercial lab assays was 85%. Agreement for identifying B. pertussis was 87% for 3,663 BpBh specimens and 98% for identifying B. parapertussis in 310 BppBb specimens. CDC's assay detected B. holmesii in 55/3,984 (1.4%) specimens. Most discrepant results (410/490, 82%) were BpBh specimens interpreted as indeterminate B. pertussis at CDC. We found a small portion of B. holmesii in a sample of IS481-positive clinical specimens originally identified by commercial laboratory rt-PCR assays, suggesting that commercial PCR assays are a reliable diagnostic tool for correctly identifying Bordetella species in most patients with suspected pertussis. IMPORTANCE: When testing specimens collected from patients with suspected pertussis, large-scale commercial laboratories in the United States employ an IS481-based assay that cannot differentiate between Bordetella pertussis and Bordetella holmseii. The level of B. holmesii causing pertussis-like illness in the United States is not well-understood given that only B. pertussis is nationally notifiable. After re-testing with a multiplex, species-specific rt-PCR assay, our data show low levels of B. holmesii identified in a sample of IS481-positive clinical specimens originally identified by commercial laboratory rt-PCR assays. These results reinforce the validity of large-scale commercial rt-PCR testing as a reliable diagnostic tool for pertussis in the United States.
Asunto(s)
Infecciones por Bordetella , Bordetella pertussis , Bordetella , Reacción en Cadena en Tiempo Real de la Polimerasa , Estados Unidos , Humanos , Bordetella/genética , Bordetella/clasificación , Bordetella/aislamiento & purificación , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/diagnóstico , Bordetella pertussis/genética , Bordetella pertussis/clasificación , Bordetella pertussis/aislamiento & purificación , Tos Ferina/diagnóstico , Tos Ferina/microbiología , Reacción en Cadena de la Polimerasa Multiplex/métodos , Sensibilidad y Especificidad , Elementos Transponibles de ADN/genética , Bordetella bronchiseptica/genética , Bordetella bronchiseptica/aislamiento & purificación , Bordetella bronchiseptica/clasificaciónRESUMEN
Bordetella hinzii (B. hinzii), a Gram-negative bacillus commonly associated with respiratory infections in animals, has garnered attention for its sporadic cases in humans, particularly in immunocompromised individuals. Despite its opportunistic nature, there remains limited understanding regarding its pathogenicity, diagnostic challenges, and optimal treatment strategies, especially in the context of immunosuppression. Herein, we present the first documented case of acute bronchitis caused by B. hinzii in an immunocompromised patient following double-lung transplantation. The patient, a former smoker with sarcoidosis stage IV, underwent transplant surgery and subsequently developed a febrile episode, leading to the identification of B. hinzii in broncho-alveolar lavage samples. Antimicrobial susceptibility testing revealed resistance to multiple antibiotics, necessitating tailored treatment adjustments. Our case underscores the importance of heightened awareness among clinicians regarding B. hinzii infections and the imperative for further research to elucidate its epidemiology and optimal management strategies, particularly in immunocompromised populations.
Asunto(s)
Infecciones por Bordetella , Bordetella , Huésped Inmunocomprometido , Trasplante de Pulmón , Trasplante de Pulmón/efectos adversos , Humanos , Bordetella/aislamiento & purificación , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/diagnóstico , Masculino , Persona de Mediana Edad , Antibacterianos/uso terapéutico , Antibacterianos/farmacología , Receptores de TrasplantesRESUMEN
Bordetella pertussis is the causative pathogen of whooping cough or pertussis, a contagious respiratory disease. Aside from serodiagnosis, laboratory confirmation of pertussis is done through PCR, as B. pertussis is difficult to culture. The ELITe InGenius instrument (ELITechGroup, France) with accompanying Bordetella ELITe MGB Kit was evaluated against a laboratory-developed assay. Both assays combine two screening (IS481, IS1001) and two confirmation targets (recA, ptxA-Pr or IS1002) for optimal sensitivity and specificity. The company's stated claims on sensitivity and reproducibility were confirmed. Accuracy testing showed full concordance between both assays for the screening targets. Minor discrepancies were seen for the B. pertussis confirmation target. Some cross-reactivity with other Bordetella species was observed for the IS481-target, however, none of these were confirmed in the ptxA-Pr target. These results show the suitability of the Bordetella ELITe MGB Kit for the detection and differentiation of B. pertussis, B. parapertussis and B. holmesii.
Asunto(s)
Bordetella pertussis , Bordetella , Sensibilidad y Especificidad , Tos Ferina , Humanos , Tos Ferina/diagnóstico , Tos Ferina/microbiología , Bordetella pertussis/aislamiento & purificación , Bordetella pertussis/genética , Bordetella/aislamiento & purificación , Bordetella/clasificación , Bordetella/genética , Bordetella parapertussis/aislamiento & purificación , Bordetella parapertussis/genética , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/microbiología , Reproducibilidad de los Resultados , Juego de Reactivos para Diagnóstico/normas , Reacción en Cadena de la Polimerasa/métodos , Técnicas de Diagnóstico Molecular/métodosRESUMEN
Whole-genome sequencing (WGS) of microbial pathogens recovered from patients with infectious disease facilitates high-resolution strain characterization and molecular epidemiology. However, increasing reliance on culture-independent methods to diagnose infectious diseases has resulted in few isolates available for WGS. Here, we report a novel culture-independent approach to genome characterization of Bordetella pertussis, the causative agent of pertussis and a paradigm for insufficient genomic surveillance due to limited culture of clinical isolates. Sequencing libraries constructed directly from residual pertussis-positive diagnostic nasopharyngeal specimens were hybridized with biotinylated RNA "baits" targeting B. pertussis fragments within complex mixtures that contained high concentrations of host and microbial background DNA. Recovery of B. pertussis genome sequence data was evaluated with mock and pooled negative clinical specimens spiked with reducing concentrations of either purified DNA or inactivated cells. Targeted enrichment increased the yield of B. pertussis sequencing reads up to 90% while simultaneously decreasing host reads to less than 10%. Filtered sequencing reads provided sufficient genome coverage to perform characterization via whole-genome single nucleotide polymorphisms and whole-genome multilocus sequencing typing. Moreover, these data were concordant with sequenced isolates recovered from the same specimens such that phylogenetic reconstructions from either consistently clustered the same putatively linked cases. The optimized protocol is suitable for nasopharyngeal specimens with diagnostic IS481 Ct < 35 and >10 ng DNA. Routine implementation of these methods could strengthen surveillance and study of pertussis resurgence by capturing additional cases with genomic characterization.
Asunto(s)
Bordetella , Tos Ferina , Humanos , Bordetella pertussis/genética , Tos Ferina/diagnóstico , Tos Ferina/epidemiología , Filogenia , Genómica , ADNRESUMEN
Bordetella holmesii is a bacterium recently recognized in 1995. It is a gram-negative coccobacillus that can cause pertussis-like symptoms in humans as well as invasive infections. It is often confused with Bordetella pertussis because routine diagnostic tests for whooping cough are not species-specific. The prevalence of B. holmesii as a cause of pertussis has increased in several countries. Therefore, B. holmesii assays are important for determining the epidemiology of pertussis, for the choice of an effective treatment, and for detecting vaccination failures.
Asunto(s)
Bordetella , Tos Ferina , Humanos , Tos Ferina/diagnóstico , Tos Ferina/epidemiología , Tos Ferina/prevención & control , Bordetella pertussisRESUMEN
An increasing number of reports have described the pathogenic nature of several non-classical Bordetella spp. Among them, Bordetella hinzii and Bordetella pseudohinzii have been implicated in a myriad of respiratory-associated infections in humans and animals. We report the isolation of a genetically close relative of B. hinzii and B. pseudohinzii from the sputum of a woman in her early 60s with extensive bronchiectasis who presented with fever and brown colored sputum. The isolate had initially been identified as Bordetella avium by API 20NE, the identification system for non-enteric Gram-negative rod bacteria. Sequencing of the 16S rDNA, ompA, nrdA, and genes used in the Bordetella multilocus sequence typing scheme could not resolve the identity of this Bordetella isolate. Whole-genome single nucleotide polymorphism analysis positioned the isolate between B. hinzii and B. pseudohinzii in the phylogenetic tree, forming a distinct cluster. Whole-genome sequencing enabled the further identification of this rare organism, and should be considered for wider applications, especially the confirmation of organism identity in the clinical diagnostic microbiology laboratory.
Asunto(s)
Infecciones por Bordetella , Bordetella , Bronquiectasia , Infecciones del Sistema Respiratorio , Humanos , Animales , Femenino , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/microbiología , Filogenia , Bordetella/genética , Bronquiectasia/complicaciones , Infecciones del Sistema Respiratorio/diagnóstico , Infecciones del Sistema Respiratorio/microbiologíaRESUMEN
The Gram-negative pathogenic bacterium Bordetella bronchiseptica is a respiratory pathogen closely related to Bordetella pertussis, the causative agent of whooping cough. Despite sharing homologous virulence factors, B. bronchiseptica infects a broad range of mammalian hosts, including some experimental animals, whereas B. pertussis is strictly adapted to humans. Therefore, B. bronchiseptica is often used as a representative model to explore the pathogenicity of Bordetella in infection experiments with laboratory animals. Although Bordetella virulence factors, including toxins and adhesins have been studied well, our recent study implied that unknown virulence factors are involved in tracheal colonization and infection. Here, we investigated bacterial genes contributing to tracheal colonization by high-throughput transposon sequencing (Tn-seq). After the screening, we picked up 151 candidate genes of various functions and found that a rpoN-deficient mutant strain was defective in tracheal colonization when co-inoculated with the wild-type strain. rpoN encodes σ54 , a sigma factor that regulates the transcription of various genes, implying its contribution to various bacterial activities. In fact, we found RpoN of B. bronchiseptica is involved in bacterial motility and initial biofilm formation. From these results, we propose that RpoN supports bacterial colonization by regulating various bacteriological functions.
Asunto(s)
Infecciones por Bordetella , Bordetella bronchiseptica , Bordetella , Animales , Humanos , Bordetella bronchiseptica/genética , ARN Polimerasa Sigma 54 , Bordetella pertussis/genética , Factores de Virulencia de Bordetella/genética , Factores de Virulencia/genética , MamíferosRESUMEN
Bordetella spp. are respiratory pathogens equipped with immune evasion mechanisms. We previously characterized a Bordetella bronchiseptica mutant (RB50ΔbtrS) that fails to suppress host responses, leading to rapid clearance and long-lasting immunity against reinfection. This work revealed eosinophils as an exclusive requirement for RB50ΔbtrS clearance. We also show that RB50ΔbtrS promotes eosinophil-mediated B/T cell recruitment and inducible bronchus-associated lymphoid tissue (iBALT) formation, with eosinophils being present throughout iBALT for Th17 and immunoglobulin A (IgA) responses. Finally, we provide evidence that XCL1 is critical for iBALT formation but not maintenance, proposing a novel role for eosinophils as facilitators of adaptive immunity against B. bronchiseptica. RB50ΔbtrS being incapable of suppressing eosinophil effector functions illuminates active, bacterial targeting of eosinophils to achieve successful persistence and reinfection. Overall, our discoveries contribute to understanding cellular mechanisms for use in future vaccines and therapies against Bordetella spp. and extension to other mucosal pathogens.
Asunto(s)
Infecciones por Bordetella , Bordetella bronchiseptica , Bordetella , Humanos , Eosinófilos , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/prevención & control , ReinfecciónRESUMEN
Bordetella hinzii has emerged as an unusual cause of infection in immunocompromised patients, previously linked to zoonotic transmission. Antimicrobial susceptibility and genetic diversity of B. hinzii are poorly understood. This study reports phenotypic and genomic characteristics of the first four Australian isolates of B. hinzii obtained from elderly immunocompromised patients. Bordetella hinzii isolates were identified by MALDI-TOF and whole genome sequencing (WGS). Antibiotic susceptibility testing was performed using disk diffusion or E-test. Genomes of B. hinzii were analysed in global context. A phylogenetic tree was constructed of all isolates using Roary and a maximum-likelihood tree was generated from the core-snp alignment. Bordetella hinzii minimum inhibitory concentrations (MICs) were largely uniform with high MICs to ampicillin, ceftriaxone and ciprofloxacin and low MICs to meropenem and piperacillin-tazobactam. Genomic analysis of isolate sequences divided strains analysed into two phylogenetically distinct groups, with one Australian B. hinzii isolate (AUS-4) assigned to Group 1, and the remaining isolates (AUS1-AUS3 and AUS-5) to Group 2. Single nucleotide polymorphism (SNP) analysis revealed two isolates, AUS-1 and AUS-2, were closely related with 14 SNP differences between them. All other Australian isolates were unrelated to each and all other isolates from the international dataset. Bordetella hinzii appears to pose a risk to immunocompromised individuals but remains susceptible to extended spectrum ß-lactam and carbapenem antibiotics. Genomic analysis suggested a dissemination of genetically distinct strains.
Asunto(s)
Bordetella , Infecciones del Sistema Respiratorio , Humanos , Anciano , Filogenia , Australia , Bordetella/genética , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Pruebas de Sensibilidad MicrobianaRESUMEN
Coinfections/mixed infections are common in the respiratory tract. Many times existing organisms have similar risk factors and clinical features that make the diagnosis difficult. Coronavirus diagnosed in 2019 (COVID-19) and tuberculosis (TB) are two such diseases. Patients with TB have lower cellular immunity and impaired pulmonary function. In such environment, atypical organisms, can infect and make the outcome unfavorable. A 21-year-old malnourished (body mass index- 15 kg/m2) girl presented with fever and cough for 10 days. Sputum for Cartridge Based Nucleic Acid Amplification Test demonstrated Mycobacterium tuberculosis with no rifampin resistance. Fever persisted (100-101°F) and saturation was dropping even after 10 days of antitubercular treatment. A repeat reverse transcription-polymerase chain reaction was done and was positive. In view of persistent symptoms after 20 days, bronchoscopy was done, and cultures showed Bordetella bronchiseptica. Fever and symptoms resolved completely after initiation of the sensitive drug. Diagnostic delay in coinfections can lead to increased morbidity and mortality.
Asunto(s)
Bordetella , COVID-19 , Coinfección , Mycobacterium tuberculosis , Tuberculosis Pulmonar , Tuberculosis , Femenino , Humanos , Adulto Joven , Adulto , Coinfección/diagnóstico , Tuberculosis Pulmonar/microbiología , Diagnóstico Tardío , Tuberculosis/complicaciones , Tuberculosis/diagnóstico , Tuberculosis/tratamiento farmacológico , Mycobacterium tuberculosis/genética , Esputo/microbiologíaRESUMEN
The purpose of this study is to identify predictive factors associated with missed diagnosis of B. pertussis-B. holmesii co-infection by assessing the analytical performance of a commercially available multiplexed PCR assay and by building a prediction model based on clinical signs and symptoms for detecting co-infections. This is a retrospective study on the electronic health records of all clinical samples that tested positive to either B. pertussis or B. holmesii from January 2015 to January 2018 at Geneva University Hospitals. Multivariate logistic regression was used to build a model for co-infection prediction based on the electronic health record chart review. Limit of detection was determined for all targets of the commercial multiplexed PCR assay used on respiratory samples. A regression model, developed from clinical symptoms and signs, predicted B. pertussis and B. holmesii co-infection with an accuracy of 82.9% (95% CI 67.9-92.8%, p value = .012), for respiratory samples positive with any of the two tested Bordetella species. We found that the LOD of the PCR reaction targeting ptxS1 is higher than that reported by the manufacturer by a factor 10. The current testing strategy misses B. pertussis and B. holmesii co-infections by reporting only B. holmesii infections. Thus, we advocate to perform serological testing for detecting a response against pertussis toxin whenever a sample is found positive for B. holmesii. These findings are important, both from a clinical and epidemiological point of view, as the former impacts the choice of antimicrobial drugs and the latter biases surveillance data, by underestimating B. pertussis infections during co-infections.
Asunto(s)
Infecciones por Bordetella , Bordetella , Coinfección , Tos Ferina , Bacterias Aerobias , Bordetella/genética , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/epidemiología , Infecciones por Bordetella/microbiología , Bordetella pertussis/genética , Coinfección/diagnóstico , ADN Bacteriano/análisis , Factor X , Humanos , Diagnóstico Erróneo , Toxina del Pertussis , Estudios Retrospectivos , Tos Ferina/microbiologíaRESUMEN
Bordetella bronchiseptica injects virulence proteins called effectors into host cells via a type III secretion system (T3SS) conserved among many Gram-negative bacteria. Small proteins called chaperones are required to stabilize some T3SS components or localize them to the T3SS machinery. In a previous study, we identified a chaperone-like protein named Bcr4 that regulates T3SS activity in B. bronchiseptica. Bcr4 does not show strong sequence similarity to well-studied T3SS proteins of other bacteria, and its function remains to be elucidated. Here, we investigated the mechanism by which Bcr4 controls T3SS activity. A pulldown assay revealed that Bcr4 interacts with BscI, based on its homology to other bacterial proteins, to be an inner rod protein of the T3SS machinery. An additional pulldown assay using truncated Bcr4 derivatives and secretion profiles of B. bronchiseptica producing truncated Bcr4 derivatives showed that the Bcr4 C-terminal region is necessary for the interaction with BscI and activation of the T3SS. Moreover, the deletion of BscI abolished the secretion of type III secreted proteins from B. bronchiseptica and the translocation of a cytotoxic effector into cultured mammalian cells. Finally, we show that BscI is unstable in the absence of Bcr4. These results suggest that Bcr4 supports the construction of the T3SS machinery by stabilizing BscI. This is the first demonstration of a chaperone for the T3SS inner rod protein among the virulence bacteria possessing the T3SS. IMPORTANCE The type III secretion system (T3SS) is a needle-like complex that projects outward from bacterial cells. Bordetella bronchiseptica uses the T3SS to inject virulence proteins into host cells. Our previous study reported that a protein named Bcr4 is essential for the secretion of virulence proteins from B. bronchiseptica bacterial cells and delivery through the T3SS. Because other bacteria lack a Bcr4 homologue, the function of Bcr4 has not been elucidated. In this study, we discovered that Bcr4 interacts with BscI, a component of the T3SS machinery. We show that a B. bronchiseptica BscI-deficient strain was unable to secrete type III secreted proteins. Furthermore, in a B. bronchiseptica strain that overproduces T3SS component proteins, Bcr4 is required to maintain BscI in bacterial cells. These results suggest that Bcr4 stabilizes BscI to allow construction of the T3SS in B. bronchiseptica.
Asunto(s)
Bordetella bronchiseptica , Bordetella , Animales , Sistemas de Secreción Tipo III/metabolismo , Bordetella/metabolismo , Bordetella bronchiseptica/genética , Chaperonas Moleculares/genética , Chaperonas Moleculares/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Mamíferos/metabolismoRESUMEN
Objective: To evaluate and expand the automatic identification and clustering of clinical Bordetella species by MALDI-TOF MS. Methods: Twenty-eight field isolated strains, identified by whole-gene sequencing analysis, were analyzed by MALDI-TOF MS, and the spectra obtained were used to replenish the internal database of the manufacturer. To evaluate and expand the robustness of the database, MALDI-TOF MS identified 91 clinical isolates (except those used for implementation). A distance tree based on mass spectrometry data is constructed to confirm similarity and clusters of each clinical Bordetella species by using the MALDI Biotyper 3.1 software. Results: In this research, when we used the implemented Bruker Daltonics database in our laboratory, 91 clinical isolates were identified at the genus level (100%) and 93.4% were identified at the species level (85/91). We performed proteomics analysis and divided these 91 isolates into cluster I (2.2%) and cluster II (97.8%). The largest group is cluster II (n = 89 isolates), which has been divided into two subclusters. Trees created by analyzing the protein mass spectra of the three species of the clinical isolates reflected their classification. Conclusion: MALDI-TOF MS may present an attractive alternative to automatically confirm and cluster the fastidious bacteria difficult to culture. Extension of identification of the MALDI-TOF MS database is viably fast, more efficient, and alternative to conventional methods in confirming the classical Bordetella species. This strategy could promote the epidemiological and taxonomic research of this important pathogen.
Asunto(s)
Bordetella , Técnicas de Tipificación Bacteriana/métodos , Bordetella/genética , Bases de Datos Factuales , Humanos , Programas Informáticos , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción/métodosRESUMEN
Contamination of soil by antibiotics and heavy metals originating from hospital facilities has emerged as a major cause for the development of resistant microbes. We collected soil samples surrounding a hospital effluent and measured the resistance of bacterial isolates against multiple antibiotics and heavy metals. One strain BMCSI 3 was found to be sensitive to all tested antibiotics. However, it was resistant to many heavy metals and metalloids like cadmium, chromium, copper, mercury, arsenic, and others. This strain was motile and potentially spore-forming. Whole-genome shotgun assembly of BMCSI 3 produced 4.95 Mb genome with 4,638 protein-coding genes. The taxonomic and phylogenetic analysis revealed it, to be a Bordetella petrii strain. Multiple genomic islands carrying mobile genetic elements; coding for heavy metal resistant genes, response regulators or transcription factors, transporters, and multi-drug efflux pumps were identified from the genome. A comparative genomic analysis of BMCSI 3 with annotated genomes of other free-living B. petrii revealed the presence of multiple transposable elements and several genes involved in stress response and metabolism. This study provides insights into how genomic reorganization and plasticity results in evolution of heavy metals resistance by acquiring genes from its natural environment.
Asunto(s)
Metales Pesados , Suelo , Antibacterianos , Bordetella , Genómica , Hospitales , Metales Pesados/toxicidad , FilogeniaRESUMEN
Patients infected with severe acute respiratory syndrome coronavirus 2 might have bacterial and fungal superinfections develop. We describe a clinical case of coronavirus disease with pulmonary aspergillosis associated with Bordetella hinzii pneumonia in an immunocompetent patient in France. B. hinzii infections are rare in humans and develop secondary to immunosuppression or debilitating diseases.