RESUMEN
Between March and October 2022, a peak of detection of Bordetella parapertussis by qPCR, real-time PCR was observed in France.Hypothesis/Gap Statement. Whether this peak was due to resurgence from previous circulating lineages or reintroduction into the country was unknown.Objective. The objective of this study is to understand B. parapertussis-transient increase observed in France in 2022 whereas it had virtually stopped being reported since the start of the COVID-19 pandemic in 2020.Methods. We analysed real-time PCR (qPCR) data from the two largest French outpatient laboratories performing whooping cough diagnosis and characterized all B. parapertussis isolates collected in the 2016-2022 period by the French National Reference Centre for Whooping Cough.Results. Microbiological analyses reveal that 13 of 18 bacterial isolates collected in 2022 produce the vaccine antigen pertactin, whereas none of the 22 isolates collected in the 2016-2021 period did.Conclusion. We hypothesize a re-introduction of B. parapertussis from regions of the world where whole-cell vaccines are still in use.
Asunto(s)
Bordetella parapertussis , Tos Ferina , Francia/epidemiología , Humanos , Bordetella parapertussis/genética , Bordetella parapertussis/aislamiento & purificación , Tos Ferina/epidemiología , Tos Ferina/microbiología , Reacción en Cadena en Tiempo Real de la Polimerasa , Proteínas de la Membrana Bacteriana Externa/genética , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/epidemiología , Niño , Preescolar , Adulto , Factores de Virulencia de Bordetella/genética , Femenino , COVID-19/epidemiología , Adolescente , Lactante , Masculino , Adulto JovenRESUMEN
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
B. parapertussis is a bacterium that causes whooping cough, a severe respiratory infection disease, that has shown an increased incidence in the population. Upon transmission through aerosol droplets, the initial steps of host colonization critically depend on the bacterial adhesins. We here described BPP0974, a B. parapertussis protein that exhibits the typical domain architecture of the large repetitive RTX adhesin family. BPP0974 was found to be retained in the bacterial membrane and secreted into the culture medium. This protein was found overexpressed in the avirulent phase of B. parapertussis, the phenotype proposed for initial host colonization. Interestingly, BPP0974 was found relevant for the biofilm formation as well as involved in the bacterial attachment to and survival within the respiratory epithelial cells. Taken together, our results suggest a role for BPP0974 in the early host colonization and pathogenesis of B. parapertussis.
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Adhesinas Bacterianas , Adhesión Bacteriana , Biopelículas , Bordetella parapertussis , Células Epiteliales , Biopelículas/crecimiento & desarrollo , Adhesinas Bacterianas/genética , Adhesinas Bacterianas/metabolismo , Bordetella parapertussis/genética , Bordetella parapertussis/metabolismo , Humanos , Células Epiteliales/microbiología , Viabilidad Microbiana , Tos Ferina/microbiología , Regulación Bacteriana de la Expresión Génica , Línea CelularRESUMEN
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
To determine changes in Bordetella pertussis and B. parapertussis detection rates, we analyzed 1.43 million respiratory multiplex PCR test results from US facilities from 2019 through mid-2023. From mid-2022 through mid-2023, Bordetella spp. detection increased 8.5-fold; 95% of detections were B. parapertussis. While B. parapertussis rates increased, B. pertussis rates decreased.
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Infecciones por Bordetella , Bordetella parapertussis , Enfermedades Transmisibles Emergentes , Bordetella parapertussis/genética , Bordetella parapertussis/aislamiento & purificación , Estados Unidos/epidemiología , Humanos , Infecciones por Bordetella/epidemiología , Infecciones por Bordetella/microbiología , Infecciones por Bordetella/diagnóstico , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/microbiología , Bordetella pertussis/genética , Bordetella pertussis/aislamiento & purificación , Historia del Siglo XXI , Niño , Preescolar , Tos Ferina/epidemiología , Tos Ferina/microbiología , Tos Ferina/diagnóstico , Adulto , Adolescente , Lactante , Reacción en Cadena de la Polimerasa Multiplex , Adulto JovenRESUMEN
INTRODUCTION: Cyclical pertussis epidemics primarily affect young infants. This study aims to estimate pertussis prevalence during the ongoing 2023 outbreak at our institution, focusing on affected age groups and clinical presentations. MATERIEL AND METHODS: This retrospective study includes patients admitted to Rabat University Hospital Center from 1st January 2021 to 30th June 2023. Symptomatic patients underwent Multiplex Respiratory Panel PCR testing for respiratory infections. The analysis included cases where RT-PCR identified Bordetella spp., with data analysed using SPSS 15.0. RESULTS: Pertussis cases sharply increased from December 2022, constituting 85.4 % of positive samples. Most cases (78.2 %) occurred in infants under 3 months, presenting symptoms such as coughing (94.5 %) and dyspnoea (94.5 %). Pertussis was suspected in 60 % of RT-PCR confirmed cases. B. pertussis DNA was identified in 81.8 % of cases and B. parapertussis DNA in 18.2 % of cases. CONCLUSION: The study exposes a significant pertussis outbreak affecting predominantly young infants.
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Bordetella pertussis , Brotes de Enfermedades , Tos Ferina , Humanos , Tos Ferina/epidemiología , Tos Ferina/microbiología , Lactante , Estudios Retrospectivos , Masculino , Femenino , Bordetella pertussis/genética , Bordetella pertussis/aislamiento & purificación , Preescolar , Marruecos/epidemiología , Niño , Hospitalización/estadística & datos numéricos , Recién Nacido , Prevalencia , Adolescente , Bordetella parapertussis/genética , Bordetella parapertussis/aislamiento & purificaciónRESUMEN
Whooping cough is a disease caused by Bordetella pertussis, whose morbidity has increased, motivating the improvement of current vaccines. Reverse vaccinology is a strategy that helps identify proteins with good characteristics fast and with fewer resources. In this work, we applied reverse vaccinology to study the B. pertussis proteome and pangenome with several in-silico tools. We analyzed the B. pertussis Tohama I proteome with NERVE software and compared 234 proteins with B. parapertussis, B. bronchiseptica, and B. holmessi. VaxiJen was used to calculate an antigenicity value; our threshold was 0.6, selecting 84 proteins. The candidates were depurated and grouped in eight family proteins to select representative candidates, according to bibliographic information and their immunological response predicted with ABCpred, Bcepred, IgPred, and C-ImmSim. Additionally, a pangenome study was conducted with 603 B. pertussis strains and PanRV software, identifying 3421 core proteins that were analyzed to select the best candidates. Finally, we selected 15 proteins from the proteome study and seven proteins from the pangenome analysis as good vaccine candidates.
Asunto(s)
Bordetella parapertussis , Tos Ferina , Humanos , Bordetella pertussis/genética , Tos Ferina/prevención & control , Proteoma/metabolismo , Vacunología , Bordetella parapertussis/metabolismo , Vacuna contra la Tos FerinaRESUMEN
B. parapertussis is one of the etiological agents of whooping cough. Once inhaled, the bacteria bind to the respiratory epithelium and start the infection. Little is known about this first step of host colonization and the role of the human airway epithelial barrier on B. parapertussis infection. We here investigated the outcome of the interaction of B. parapertussis with a polarized monolayer of respiratory epithelial cells. Our results show that B. parapertussis preferentially attaches to the intercellular boundaries, and causes the disruption of the tight junction integrity through the action of adenylate cyclase toxin (CyaA). We further found evidence indicating that this disruption enables the bacterial access to components of the basolateral membrane of epithelial cells to which B. parapertussis efficiently attaches and gains access to the intracellular location, where it can survive and eventually spread back into the extracellular environment. Altogether, these results suggest that the adenylate cyclase toxin enables B. parapertussis to overcome the epithelial barrier and eventually establish a niche of persistence within the respiratory epithelial cells.
Asunto(s)
Bordetella parapertussis , Tos Ferina , Humanos , Bordetella parapertussis/metabolismo , Toxina de Adenilato Ciclasa/metabolismo , Bordetella pertussis/metabolismo , Espacio Intracelular/metabolismo , Tos Ferina/microbiología , Células Epiteliales/metabolismoRESUMEN
The pathogenic bacteria Bordetella pertussis and Bordetella parapertussis cause pertussis (whooping cough) and pertussis-like disease, respectively, both of which are characterized by paroxysmal coughing. We previously reported that pertussis toxin (PTx), which inactivates heterotrimeric GTPases of the Gi family through ADP-ribosylation of their α subunits, causes coughing in combination with Vag8 and lipid A in B. pertussis infection. In contrast, the mechanism of cough induced by B. parapertussis, which produces Vag8 and lipopolysaccharide (LPS) containing lipid A, but not PTx, remained to be elucidated. Here, we show that a toxin we named deacylating autotransporter toxin (DAT) of B. parapertussis inactivates heterotrimeric Gi GTPases through demyristoylation of their α subunits and contributes to cough production along with Vag8 and LPS. These results indicate that DAT plays a role in B. parapertussis infection in place of PTx.
Asunto(s)
Bordetella parapertussis , Toxinas Biológicas , Tos Ferina , Humanos , Sistemas de Secreción Tipo V , Tos , Lípido A , Lipopolisacáridos/toxicidad , Bordetella pertussis , Toxina del PertussisRESUMEN
RATIONALE: Bordetella parapertussis caused by a severe infection is rare in clinical practice. Here, we report a case of plastic bronchitis (PB). PATIENT CONCERNS: A 4-year-old girl with a 2-day history of fever, paroxysmal cough, and subconjunctival hemorrhage. DIAGNOSES: The diagnoses were (1) B parapertussis , (2) pulmonary atelectasis, and (3) PB. INTERVENTIONS: The patient received azithromycin and underwent bronchoscopy. OUTCOMES: Symptoms disappeared after treatment. The patient had an outpatient follow-up of 2 months without respiratory symptoms. LESSONS: PB can lead to respiratory failure if not intervened in the early stages.
Asunto(s)
Infecciones por Bordetella , Bordetella parapertussis , Bronquitis , Femenino , Humanos , Preescolar , Bordetella pertussis , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/complicaciones , Bronquitis/complicaciones , Bronquitis/diagnóstico , PlásticosRESUMEN
B. parapertussis is a whooping cough etiological agent, whose incidence in the population has increased remarkably. Virulence factors involved in the bacterial infection, however, remain poorly investigated. We here studied the role of adenylate cyclase (CyaA), the main toxin of B. parapertussis, in the outcome of the bacterial interaction with macrophages. Our results showed that B. parapertussis CyaA intoxicates human macrophages, prevents bacterial phagocytosis and precludes phago-lysosomal fusion eventually promoting the bacterial survival to the encounter with these immune cells. Accordingly, we found that B. parapertussis CyaA induces the transcriptional downregulation of host genes encoding for antimicrobial peptides, proteins involved in bacterial intracellular killing, and the pro-inflammatory cytokine TNF-α, while induces the upregulation of the anti-inflammatory cytokine IL-10. Together with previous reports suggesting a protective role of B. parapertussis CyaA against neutrophils bactericidal activity, the results of this study suggest a central role of CyaA in B. parapertussis immune evasion and persistence.
Asunto(s)
Bordetella parapertussis , Tos Ferina , Humanos , Toxina de Adenilato Ciclasa/genética , Toxina de Adenilato Ciclasa/metabolismo , Bordetella parapertussis/genética , Bordetella pertussis/metabolismo , Macrófagos , Tos Ferina/prevención & controlRESUMEN
Pertussis also known as whooping cough is a respiratory infection in humans particularly with severe symptoms in infants and usually caused by Bordetella pertussis. However, Bordetella parapertussis can also cause a similar clinical syndrome. During 2012 to 2015, from nasal swabs sent from different provinces to the pertussis reference laboratory of Pasture Institute of Iran for pertussis confirmation, seven B. parapertussis isolates were identified by bacterial culture, biochemical tests, and the presence of IS1001 insertion in the genome. The expression of pertactin (Prn) as one the major virulence factor for bacterial adhesion was investigated using western blot. Moreover, the genomic characteristic of one recently collected isolate, IRBP134, from a seven-month infant was investigated using Illumina NextSeq sequencing protocol. The results revealed the genome with G+C content 65% and genome size 4.7 Mbp. A total of 81 single nucleotide polymorphisms and 13 short insertions and deletions were found in the genome compared to the B. parapertussis 12822 as a reference genome showing ongoing evolutionary changes. A phylogeny relationship of IRBP134 was also investigated using global B. parapertussis available genomes.
Asunto(s)
Bordetella parapertussis , Tos Ferina , Bordetella parapertussis/genética , Bordetella pertussis/genética , Humanos , Lactante , Irán , Factores de Virulencia/metabolismo , Tos Ferina/diagnóstico , Tos Ferina/microbiologíaRESUMEN
An increase in positive Bordetella parapertussis tests among patients in a teaching hospital in the Netherlands resulted in enhanced infection control and microbiological surveillance. Further analysis revealed that batches of contaminated nasopharyngeal swabs were associated with a pseudo-outbreak, resulting in incorrect diagnoses, antimicrobial treatments, isolation precautions, and public health notifications.
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Infecciones por Bordetella , Bordetella parapertussis , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/epidemiología , Infecciones por Bordetella/microbiología , Bordetella pertussis , Brotes de Enfermedades , Humanos , Países Bajos/epidemiologíaRESUMEN
Whooping cough (pertussis) is a highly contagious respiratory bacterial infection caused by Bordetella pertussis and is an important cause of morbidity and mortality worldwide, particularly in infants. Bordetella parapertussis can cause a similar, but usually less severe pertussis-like disease. Bordetella pertussis has a number of virulence factors including adhesins and toxins which allow the organism to bind to ciliated epithelial cells in the upper respiratory tract and interfere with host clearance mechanisms. Typical symptoms of pertussis include paroxysmal cough with characteristic whoop and vomiting. Severe complications and deaths occur mostly in infants. Laboratory confirmation can be performed by isolation, detection of genomic DNA or specific antibodies. Childhood vaccination is safe, effective and remains the best control method available. Many countries have replaced whole-cell pertussis vaccines (wP) with acellular pertussis vaccines (aP). Waning protection following immunisation with aP is considered to be more rapid than that from wP. Deployed by resource-rich countries to date, maternal immunisation programmes have also demonstrated high efficacy in preventing hospitalisation and death in infants by passive immunisation through transplacental transfer of maternal antibodies.
Asunto(s)
Bordetella parapertussis/inmunología , Bordetella pertussis/inmunología , Vacuna contra la Tos Ferina/inmunología , Factores de Virulencia/inmunología , Tos Ferina/prevención & control , Humanos , LactanteRESUMEN
Bordetella parapertussis causes respiratory infection in humans, with a mild pertussis (whooping cough)-like disease. The organism produces a brown pigment, the nature and biological significance of which have not been elucidated. Here, by screening a transposon library, we demonstrate that the gene encoding 4-hydroxyphenylpyruvate dioxygenase (HppD) is responsible for production of this pigment. Our results also indicate that the brown pigment produced by the bacterium is melanin, because HppD is involved in the biosynthesis of a type of melanin called pyomelanin, and homogentisic acid, the monomeric precursor of pyomelanin, was detected by high-performance liquid chromatography-mass spectrometry analyses. In an infection assay using macrophages, the hppD-deficient mutant was internalized by THP-1 macrophage-like cells, similar to the wild-type strain, but was less able to survive within the cells, indicating that melanin protects B. parapertussis from intracellular killing in macrophages. Mouse infection experiments also showed that the hppD-deficient mutant was eliminated from the respiratory tract more rapidly than the wild-type strain, although the initial colonization levels were comparable between the two strains. In addition, melanin production by B. parapertussis was not regulated by the BvgAS two-component system, which is the master regulator for the expression of genes contributing to the bacterial infection. Taken together, our findings indicate that melanin produced by B. parapertussis in a BvgAS-independent manner confers a survival advantage to the bacterium during host infection. IMPORTANCE In addition to the Gram-negative bacterium Bordetella pertussis, the etiological agent of pertussis, Bordetella parapertussis also causes respiratory infection in humans, with a mild pertussis-like disease. These bacteria are genetically closely related and share many virulence factors, including adhesins and toxins. However, B. parapertussis is clearly distinguished from B. pertussis by its brown pigment production, the bacteriological significance of which remains unclear. Here, we demonstrate that this pigment is melanin, which is known to be produced by a wide range of organisms from prokaryotes to humans and helps the organisms to survive under various environmental stress conditions. Our results show that melanin confers a survival advantage to B. parapertussis within human macrophages through its protective effect against reactive oxygen species and eventually contributes to respiratory infection of the bacterium in mice. This study proposes melanin as a virulence factor involved in the increased survival of B. parapertussis during host infection.
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Bordetella parapertussis/patogenicidad , Melaninas/metabolismo , Melaninas/fisiología , Pigmentación de la Piel/fisiología , Tos Ferina/metabolismo , Adhesinas Bacterianas/metabolismo , Animales , Humanos , Masculino , Ratones , Ratones Endogámicos C57BL , Infecciones del Sistema Respiratorio/etiología , Células THP-1 , Factores de Virulencia/metabolismo , Tos Ferina/microbiologíaRESUMEN
The highly contagious whooping cough agent Bordetella pertussis has evolved as a human-restricted pathogen from a progenitor which also gave rise to Bordetella parapertussis and Bordetella bronchiseptica. While the latter colonizes a broad range of mammals and is able to survive in the environment, B. pertussis has lost its ability to survive outside its host through massive genome decay. Instead, it has become a highly successful human pathogen by the acquisition of tightly regulated virulence factors and evolutionary adaptation of its metabolism to its particular niche. By the deployment of an arsenal of highly sophisticated virulence factors it overcomes many of the innate immune defenses. It also interferes with vaccine-induced adaptive immunity by various mechanisms. Here, we review data from invitro, human and animal models to illustrate the mechanisms of adaptation to the human respiratory tract and provide evidence of ongoing evolutionary adaptation as a highly successful human pathogen.
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Bordetella bronchiseptica , Bordetella parapertussis , Animales , Bordetella bronchiseptica/genética , Bordetella parapertussis/metabolismo , Bordetella pertussis/genética , Bordetella pertussis/metabolismo , Humanos , Mamíferos , Virulencia , Factores de Virulencia/genética , Factores de Virulencia/metabolismoRESUMEN
Noncoding small RNAs (sRNAs) are crucial for the posttranscriptional regulation of gene expression in all organisms and are known to be involved in the regulation of bacterial virulence. In the human pathogen Bordetella pertussis, which causes whooping cough, virulence is controlled primarily by the master two-component system BvgA (response regulator)/BvgS (sensor kinase). In this system, BvgA is phosphorylated (Bvg+ mode) or nonphosphorylated (Bvg- mode), with global transcriptional differences between the two. B. pertussis also carries the bacterial sRNA chaperone Hfq, which has previously been shown to be required for virulence. Here, we conducted transcriptomic analyses to identify possible B. pertussis sRNAs and to determine their BvgAS dependence using transcriptome sequencing (RNA-seq) and the prokaryotic sRNA prediction program ANNOgesic. We identified 143 possible candidates (25 Bvg+ mode specific and 53 Bvg- mode specific), of which 90 were previously unreported. Northern blot analyses confirmed all of the 10 ANNOgesic candidates that we tested. Homology searches demonstrated that 9 of the confirmed sRNAs are highly conserved among B. pertussis, Bordetella parapertussis, and Bordetella bronchiseptica, with one that also has homologues in other species of the Alcaligenaceae family. Using coimmunoprecipitation with a B. pertussis FLAG-tagged Hfq, we demonstrated that 3 of the sRNAs interact directly with Hfq, which is the first identification of sRNA binding to B. pertussis Hfq. Our study demonstrates that ANNOgesic is a highly useful tool for the identification of sRNAs in this system and that its combination with molecular techniques is a successful way to identify various BvgAS-dependent and Hfq-binding sRNAs. IMPORTANCE Noncoding small RNAs (sRNAs) are crucial for posttranscriptional regulation of gene expression in all organisms and are known to be involved in the regulation of bacterial virulence. We have investigated the presence of sRNAs in the obligate human pathogen B. pertussis, using transcriptome sequencing (RNA-seq) and the recently developed prokaryotic sRNA search program ANNOgesic. This analysis has identified 143 sRNA candidates (90 previously unreported). We have classified their dependence on the B. pertussis two-component system required for virulence, namely, BvgAS, based on their expression in the presence/absence of the phosphorylated response regulator BvgA, confirmed several by Northern analyses, and demonstrated that 3 bind directly to B. pertussis Hfq, the RNA chaperone involved in mediating sRNA effects. Our study demonstrates the utility of combining RNA-seq, ANNOgesic, and molecular techniques to identify various BvgAS-dependent and Hfq-binding sRNAs, which may unveil the roles of sRNAs in pertussis pathogenesis.
Asunto(s)
Proteínas Bacterianas/genética , Bordetella pertussis/genética , Bordetella pertussis/patogenicidad , ARN Pequeño no Traducido/genética , Factores de Transcripción/genética , Factores de Virulencia de Bordetella/genética , Bordetella bronchiseptica/genética , Bordetella parapertussis/genética , Biología Computacional , Perfilación de la Expresión Génica , Regulación Bacteriana de la Expresión Génica/genética , Proteína de Factor 1 del Huésped/genética , Programas Informáticos , Transcriptoma/genética , Virulencia/genéticaRESUMEN
Bordetella pertussis is the causative agent of pertussis, which mainly affects unvaccinated children, while Bordetella parapertussis causes a disease presenting clinical characteristics that are indistinguishable from whooping cough. Despite high vaccination coverage, pertussis remains a public health concern worldwide, with approximately 140000 cases reported annually. Here we determined the prevalence of B. pertussis and B. parapertussis infection among infants under one year of age by polymerase chain reaction (PCR); our aim being to identify whether the data obtained relates to the relevant sociodemographic and clinical data. The study included 86 samples of nasopharyngeal swabs from infants aged between 0-12 months, who were reported as probable cases of whooping cough by the health centers around the Ecuadorian highlands, from August 2016 to July 2017. The nasopharyngeal swabs were cultured and microbiological and molecular analyses were performed. B. pertussis was identified by PCR in 41% of the samples (30/86), more than half of which corresponded to infants aged between 0-3 months. Moreover, a statistically significant correlation (p<0.05) between the identification of bacteria in culture and the catarrhal stage of the disease was observed. The results obtained from the study highlighted the need for an active national surveillance of pertussis, in particular for laboratory testing, to provide a highly sensitive and more specific diagnosis of Bordetella infection.
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Infecciones por Bordetella , Bordetella parapertussis , Tos Ferina , Infecciones por Bordetella/diagnóstico , Infecciones por Bordetella/epidemiología , Bordetella pertussis , Niño , Ecuador/epidemiología , Humanos , Lactante , Recién Nacido , Tos Ferina/diagnóstico , Tos Ferina/epidemiologíaRESUMEN
Detection of Bordetella pertussis and Bordetella parapertussis using molecular methods is sensitive and specific with a short turnaround time compared to other diagnostic methods. In this multicenter study, we compared the performance of the Simplexa Bordetella Direct kit to those of other molecular assays in detecting and differentiating B. pertussis and B. parapertussis in nasopharyngeal swab specimens. The limits of detection (LODs) were 150 CFU/ml or 3 fg/µl of DNA for B. pertussis and 1,500 CFU/ml or 10 fg/µl of DNA for B. parapertussis A total of 1,103 fresh and residual frozen specimens from eight clinical sites were tested. Combining the data from individual clinical sites using different comparative assays, the overall positive percent agreement (PPA) and negative percent agreement (NPA) for B. pertussis were 98.7% and 97.3%, respectively. The overall PPA and NPA for B. parapertussis were 96.7% and 100%, respectively. For prospective fresh specimens, the overall PPA and NPA for both targets were 97.7% and 99.3%, respectively. For retrospective frozen specimens, the overall PPA and NPA for both targets were 92.6% and 93.2%, respectively. The percentage of invalid results was 1.0%. A cross-reactivity study using 74 non-Bordetella bacterial species and five yeast species revealed that the Simplexa Bordetella Direct kit was 100% specific. The hands-on time and assay run time of the Simplexa Bordetella Direct kit are favorable compared to those of other commercial and laboratory-developed tests. In summary, the Simplexa Bordetella Direct kit has a performance comparable to those of other molecular assays for the detection of B. pertussis and B. parapertussis.