Reemergence of Bordetella parapertussis, United States, 2019-2023.

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.

Non-classical Bordetella sp. (closely related to Bordetella hinzii and Bordetella pseudohinzii) lower respiratory tract infection in a patient with extensive bronchiectasis: a case report.

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.

RpoN (sigma factor 54) contributes to bacterial fitness during tracheal colonization of Bordetella bronchiseptica.

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.

Anti-Bordetella bronchiseptica effects of targeted bacteriophages via microbiome and metabolic mediated mechanisms.

Bordetella bronchiseptica poses a significant challenge in the context of respiratory infections, particularly in weanling pigs. In this study, we investigated the impact of a novel targeted bacteriophage in controlling B. bronchiseptica challenge (BBC) in an experimental design involving five distinct treatment groups: NC (no challenge), PC (BBC challenge), BF (108 pfu bacteriophage/kg diet + BBC), BN (2 × 107 pfu/day bacteriophage by nasal spray + BBC), and AT (antibiotic + BBC). The experiment was conducted for 2 weeks. The highest turbinate score was observed in the PC. The BF treatment showed higher plasma IL (interleukine)-1ß and IL-6 compared with the BN and AT treatments. Plasma concentrations of IL-1ß were increased in the BF pigs compared with the BN, AT, and NC. Among the BBC groups, the PC treatment exhibited a higher abundance of Staphylococcus. aureus and B. bronchiseptica in the lung. A lower S. aureus, Streptococcus. suis, and B. bronchiseptica colonization was detected in the AT compared with the BF and BN treatments. The BF showed lower plasma zonulin compared with the BN and AT. A higher plasma concentration of superoxide dismutase was observed in the BF and AT compared with PC and BN. The BN influenced the glycine, serine-threonine metabolism; glycerolipid metabolism; glyoxylate-dicarboxylate metabolism; and arachidonic acid metabolism compared with the NC. In conclusion, nasal-sprayed bacteriophage effectively controlled B. bronchiseptica infection, however, their efficiency was lower than the antibiotic.

Adaptive immune protection of the middle ears differs from that of the respiratory tract.

The efficacy of the adaptive immune system in the middle ear (ME) is well established, but the mechanisms are not as well defined as those of gastrointestinal or respiratory tracts. While cellular elements of the adaptive response have been detected in the MEs following infections (or intranasal immunizations), their specific contributions to protecting the organ against reinfections are unknown. How immune protection mechanisms of the MEs compares with those in the adjacent and attached upper and lower respiratory airways remains unclear. To address these knowledge gaps, we used an established mouse respiratory infection model that we recently showed also involves ME infections. Bordetella bronchiseptica delivered to the external nares of mice in tiny numbers very efficiently infects the respiratory tract and ascends the Eustachian tube to colonize and infect the MEs, where it causes severe but acute inflammation resembling human acute otitis media (AOM). Since this AOM naturally resolves, we here examine the immunological mechanisms that clear infection and protect against subsequent infection, to guide efforts to induce protective immunity in the ME. Our results show that once the MEs are cleared of a primary B. bronchiseptica infection, the convalescent organ is strongly protected from reinfection by the pathogen despite its persistence in the upper respiratory tract, suggesting important immunological differences in these adjacent and connected organs. CD4+ and CD8+ T cells trafficked to the MEs following infection and were necessary to robustly protect against secondary challenge. Intranasal vaccination with heat killed B. bronchiseptica conferred robust protection against infection to the MEs, even though the nasopharynx itself was only partially protected. These data establish the MEs as discrete effector sites of adaptive immunity and shows that effective protection in the MEs and the respiratory tract is significantly different. This model system allows the dissection of immunological mechanisms that can prevent bacteria in the nasopharynx from ascending the ET to colonize the ME.

Bordetella spp. block eosinophil recruitment to suppress the generation of early mucosal protection.

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.

Prior infection with Bordetella bronchiseptica enhanced colonization but not disease with Streptococcus suis.

Bordetella bronchiseptica and Streptococcus suis are widely distributed swine pathogens. B. bronchiseptica is a primary pathogen and causes atrophic rhinitis and bronchopneumonia. S. suis is a contributing agent to porcine respiratory disease complex and causes systemic diseases including arthritis, meningitis, polyserositis, and septicemia. Colonization with B. bronchiseptica has been associated with increased colonization by other pathogenic bacteria and increased disease severity with viral and bacterial pathogens. It has also been reported to predispose cesarean derived, colostrum deprived (CDCD) piglets to S. suis systemic disease. Here, we evaluated the role of B. bronchiseptica colonization on S. suis colonization, dissemination, and disease in one study using conventional pigs and another using CDCD pigs. Pigs were challenged with S. suis, B. bronchiseptica, or B. bronchiseptica followed by S. suis. Incidence of S. suis disease was not increased in either study for animals pre-inoculated with B. bronchiseptica. Nasal colonization with S. suis was increased in coinfected animals, while B. bronchiseptica was similar between mono- and co-infected animals. Although increased S. suis disease was not seen in coinfected pigs, there is evidence that B. bronchiseptica can increase colonization with S. suis, which may contribute to enhanced disease when animals are stressed or immunocompromised.

Case report: Plastic bronchitis associated with Bordetella parapertussis.

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.

Adjuvant Efficacy of the ECMS-Oil on Immune Responses against Bordetella bronchiseptica in Mice through the TLR2/MyD88/NF-κB Pathway.

Bordetella infection can be efficiently prevented through vaccination. The current study investigated the effects of an extract of Cochinchina momordica seed (ECMS) combined with oil on the immune responses to the inactivated Bordetella vaccine in mice. Serum IgG and IgG1 level was significantly increased in ECMS-oil group compared to any other group (P < 0.05) 2 weeks after immunization, while groups ECMS200 µg/400 µg-oil had a markedly higher level of serum IgG2b and IgG3 than any other groups (P < 0.05). Moreover, lipopolysaccharide/ConA-stimulated proliferation of splenocytes was significantly enhanced in ECMS 400 µg-oil immunized mice in comparison with mice in any other group (P < 0.05). RT-PCR assay revealed that while ECMS800 µg-oil group had significantly higher levels of serum IL-4, IL-10, Toll-like receptor (TLR)2, and IL-1 beta than any other group (P < 0.05), the levels of serum IL-2, IL-4, and IL-10 were markedly increased in ECMS 400 µg-oil group as compared to any other groups (P < 0.05). Blood analysis showed that ECMS800 µg-oil and oil groups had a significantly higher number of immunocytes than any other groups (P < 0.05). There were significant differences in the number of IgG+, IgG2b+, and IgA+ cells in the lung between ECMS800 µg-oil group and any other groups (P < 0.05). Western blot analysis demonstrated that stimulation with ECMS 25 µg/mL or 50 ng/mL led to a significant increase in the expression of TLR2, MyD88, and NF-κB in Raw264.7 cells (P < 0.05). Compared with any other group, the expression of MyD88 was markedly increased in the cells stimulated with ECMS 50 ng/mL, as indicated by the RT-PCR analysis (P < 0.05). Overall, we observed that ECMS-oil efficiently enhanced the humoral or cellular immune responses against Bordetella and suggested that the mechanism of adjuvant activity of ECMS-oil might involve TLR2/MyD88/NF-κB signaling pathway.

Bordetella bronchiseptica and Bordetella pertussis: Similarities and Differences in Infection, Immuno-Modulation, and Vaccine Considerations.

Bordetella pertussis and Bordetella bronchiseptica belong to the genus Bordetella, which comprises 14 other species. B. pertussis is responsible for whooping cough in humans, a severe infection in children and less severe or chronic in adults. These infections are restricted to humans and currently increasing worldwide. B. bronchiseptica is involved in diverse respiratory infections in a wide range of mammals. For instance, the canine infectious respiratory disease complex (CIRDC), characterized by a chronic cough in dogs. At the same time, it is increasingly implicated in human infections, while remaining an important pathogen in the veterinary field. Both Bordetella can evade and modulate host immune responses to support their persistence, although it is more pronounced in B. bronchiseptica infection. The protective immune responses elicited by both pathogens are comparable, while there are important characteristics in the mechanisms that differ. However, B. pertussis pathogenesis is more difficult to decipher in animal models than those of B. bronchiseptica because of its restriction to humans. Nevertheless, the licensed vaccines for each Bordetella are different in terms of formulation, route of administration and immune responses induced, with no known cross-reaction between them. Moreover, the target of the mucosal tissues and the induction of long-lasting cellular and humoral responses are required to control and eliminate Bordetella. In addition, the interaction between both veterinary and human fields are essential for the control of this genus, by preventing the infections in animals and the subsequent zoonotic transmission to humans.

Characterization of Temperate LPS-Binding Bordetella avium Phages That Lack Superinfection Immunity.

Bordetella avium causes a highly infectious upper respiratory tract disease in turkeys and other poultry with high economic losses. Considering the antimicrobial resistance crisis, bacteriophages (phages) may be an alternative approach for treating bacterial infections such as bordetellosis. Here, we describe seven B. avium phages, isolated from drinking water and feces from chicken and turkey farms. They showed strong bacteriolytic activity with a broad host range and used lipopolysaccharides (LPS) as a host receptor for their adsorption. All phages are myoviruses based on their structure observed by transmission electron microscopy. Genome sequence analyses revealed genome assembly sizes ranging from 39,087 to 43,144 bp. Their permutated genomes were organized colinearly, with a conserved module order, and were packed according to a predicted headful packing strategy. Notably, they contained genes encoding putative markers of lysogeny, indicative of temperate phages, despite their lytic phenotype. Further investigation revealed that the phages could indeed undergo a lysogenic life cycle with varying frequency. However, the lysogenic bacteria were still susceptible to superinfection with the same phages. This lack of stable superinfection immunity after lysogenization appears to be a characteristic feature of B. avium phages, which is favorable in terms of a potential therapeutic use of phages for the treatment of avian bordetellosis. IMPORTANCE To maintain the effectiveness of antibiotics over the long term, alternatives to treat infectious diseases are urgently needed. Therefore, phages have recently come back into focus as they can specifically infect and lyse bacteria and are naturally occurring. However, there is little information on phages that can infect pathogenic bacteria from animals, such as the causative agent of bordetellosis of poultry, B. avium. Therefore, in this study, B. avium phages were isolated and comprehensively characterized, including whole-genome analysis. Although phenotypically the phages were thought to undergo a lytic cycle, we demonstrated that they undergo a lysogenic phase, but that infection does not confer stable host superinfection immunity. These findings provide important information that could be relevant for potential biocontrol of avian bordetellosis by using phage therapy.

Multiple rib and vertebral fractures associated with Bordetella pertussis infection: a case report.

BACKGROUND: Pertussis is a highly contagious respiratory disease caused by the bacterium Bordetella pertussis, characterized by paroxysms of severe coughing, and predominantly affects children. We report the first case of multiple fractures in the ribs, lumbar spine, and sacrum associated with severe coughing caused by Bordetella pertussis infection in an adult. CASE PRESENTATION: A 49-year-old female presented with acute-onset chest wall pain for 3 weeks. Imaging results revealed multiple fractures in the ribs and vertebrae, as well as bilateral pleural effusion, pericardial effusion, right pneumothorax, and enlargement of the left parapharyngeal and subclavian lymph nodes. The patient's bone density scan, autoimmune antibodies, bone marrow biopsy, and sacral bone biopsy all came back normal. Imaging test results found no evidence of solid tumors or active TB infection. The patient later recalled having violent coughing prior to the onset of chest pain and several family members having similar symptoms. Her blood sample was sent to the CDC, revealing Bordetella pertussis toxin (PT) IgG titer of 110.68 IU/mL. The patient was diagnosed with pertussis and multiple stress fractures from violent coughing. Symptomatic treatments were administered, and the patient's symptoms improved. The patient was followed up 8 weeks later, she reported no more coughing or chest pain. CONCLUSIONS: Pertussis is not just a pediatric disease, but diagnosis in adults is challenging as patients may present with a myriad of confusing symptoms, such as multiple stress fractures due to violent coughing. Medical and epidemiological histories are key to reaching the correct diagnosis, which is essential for appropriate treatments to avoid further complications. Adult immunization should be suggested both for the protection of the adult population and to prevent transmission to children.

Bordetella spp. utilize the type 3 secretion system to manipulate the VIP/VPAC2 signaling and promote colonization and persistence of the three classical Bordetella in the lower respiratory tract.

Introduction: Bordetella are respiratory pathogens comprised of three classical Bordetella species: B. pertussis, B. parapertussis, and B. bronchiseptica. With recent surges in Bordetella spp. cases and antibiotics becoming less effective to combat infectious diseases, there is an imperative need for novel antimicrobial therapies. Our goal is to investigate the possible targets of host immunomodulatory mechanisms that can be exploited to promote clearance of Bordetella spp. infections. Vasoactive intestinal peptide (VIP) is a neuropeptide that promotes Th2 anti-inflammatory responses through VPAC1 and VPAC2 receptor binding and activation of downstream signaling cascades. Methods: We used classical growth in vitro assays to evaluate the effects of VIP on Bordetella spp. growth and survival. Using the three classical Bordetella spp. in combination with different mouse strains we were able to evaluate the role of VIP/VPAC2 signaling in the infectious dose 50 and infection dynamics. Finally using the B. bronchiseptica murine model we determine the suitability of VPAC2 antagonists as possible therapy for Bordetella spp. infections. Results: Under the hypothesis that inhibition of VIP/VPAC2 signaling would promote clearance, we found that VPAC2-/- mice, lacking a functional VIP/VPAC2 axis, hinder the ability of the bacteria to colonize the lungs, resulting in decreased bacterial burden by all three classical Bordetella species. Moreover, treatment with VPAC2 antagonists decrease lung pathology, suggesting its potential use to prevent lung damage and dysfunction caused by infection. Our results indicate that the ability of Bordetella spp. to manipulate VIP/VPAC signaling pathway appears to be mediated by the type 3 secretion system (T3SS), suggesting that this might serve as a therapeutical target for other gram-negative bacteria. Conclusion: Taken together, our findings uncover a novel mechanism of bacteria-host crosstalk that could provide a target for the future treatment for whooping cough as well as other infectious diseases caused primarily by persistent mucosal infections.

Immunization with autotransporter Vag8 prevents coughing induced by Bordetella pertussis infection in mice.

Bordetella pertussis causes pertussis, which is characterized by paroxysmal coughing. This disease is generally prevented through vaccination; however, the number of pertussis cases is increasing worldwide despite high vaccination coverage. We previously reported that an autotransporter of B. pertussis, virulence-associated gene 8 (Vag8), causes coughing in combination with pertussis toxin and lipooligosaccharide. Here, we show that immunization with Vag8 protected mice from coughing after B. pertussis infection and enhanced the efficacy of a current pertussis vaccine containing pertussis toxoid against the cough. Our findings indicate that Vag8 could be a vaccine antigen to prevent pertussis cough.

Outbreak management of multidrug-resistant Bordetella bronchiseptica in 16 shelter-housed cats.

CASE SERIES SUMMARY: This case series describes an outbreak of multidrug-resistant (MDR) Bordetella bronchiseptica in 16 shelter-housed cats with infectious respiratory disease. Four cats presented with acute dyspnea on the same day, each with a history of previous upper respiratory disease that had resolved with treatment. Early diagnostic testing and culture and sensitivity allowed for targeted antimicrobial therapy and environmental interventions. A case definition based on exposure and clinical signs identified 12 additional presumptive cases, including the likely index case. Comprehensive outbreak management included diagnostic testing, risk assessment, vaccination, use of isolation and quarantine, increased surveillance and review of biosecurity practices. The outbreak resolved in 26 days. RELEVANCE AND NOVEL INFORMATION: Management of an MDR B bronchiseptica outbreak in shelter-housed cats has not been previously described. Along with standard population and environmental measures, early and appropriate use of necropsy, PCR and bacterial culture allowed rapid and appropriate use of effective, second-line antibiotics. Shelters are resource-challenged population centers. Veterinarians working in animal shelters can play an important role in helping to develop cost-efficient and effective antimicrobial stewardship practices for companion animal settings. Outbreak management expertise and funding for diagnostic testing, as well as application of the principles of antimicrobial stewardship, are essential components of shelter medicine practice.

Phosphorylation chemistry of the Bordetella PlrSR TCS and its contribution to bacterial persistence in the lower respiratory tract.

Bordetella species cause lower respiratory tract infections in mammals. B. pertussis and B. bronchiseptica are the causative agents of whooping cough and kennel cough, respectively. The current acellular vaccine for B. pertussis protects against disease but does not prevent transmission or colonization. Cases of pertussis are on the rise even in areas of high vaccination. The PlrSR two-component system, is required for persistence in the mouse lung. A partial plrS deletion strain and a plrS H521Q strain cannot survive past 3 days in the lung, suggesting PlrSR works in a phosphorylation-dependent mechanism. We characterized the biochemistry of B. bronchiseptica PlrSR and found that both proteins function as a canonical two-component system. His521 was essential and Glu522 was critical for PlrS autophosphorylation. Asn525 was essential for phosphatase activity. The PAS domain was critical for both PlrS autophosphorylation and phosphatase activities. PlrS could both phosphotransfer to and exert phosphatase activity toward PlrR. Unexpectedly, PlrR formed a tetramer when unphosphorylated and a dimer upon phosphorylation. Finally, we demonstrated the importance of PlrS phosphatase activity for persistence within the murine lung. By characterizing PlrSR we hope to guide future in vivo investigation for development of new vaccines and therapeutics.

Gastrointestinal helminths increase Bordetella bronchiseptica shedding and host variation in supershedding.

Co-infected hosts, individuals that carry more than one infectious agent at any one time, have been suggested to facilitate pathogen transmission, including the emergence of supershedding events. However, how the host immune response mediates the interactions between co-infecting pathogens and how these affect the dynamics of shedding remains largely unclear. We used laboratory experiments and a modeling approach to examine temporal changes in the shedding of the respiratory bacterium Bordetella bronchiseptica in rabbits with one or two gastrointestinal helminth species. Experimental data showed that rabbits co-infected with one or both helminths shed significantly more B. bronchiseptica, by direct contact with an agar petri dish, than rabbits with bacteria alone. Co-infected hosts generated supershedding events of higher intensity and more frequently than hosts with no helminths. To explain this variation in shedding an infection-immune model was developed and fitted to rabbits of each group. Simulations suggested that differences in the magnitude and duration of shedding could be explained by the effect of the two helminths on the relative contribution of neutrophils and specific IgA and IgG to B. bronchiseptica neutralization in the respiratory tract. However, the interactions between infection and immune response at the scale of analysis that we used could not capture the rapid variation in the intensity of shedding of every rabbit. We suggest that fast and local changes at the level of respiratory tissue probably played a more important role. This study indicates that co-infected hosts are important source of variation in shedding, and provides a quantitative explanation into the role of helminths to the dynamics of respiratory bacterial infections.