Heme sequestration by hemophilin from Haemophilus haemolyticus reduces respiratory tract colonization and infection with non-typeable Haemophilus influenzae

Iron acquisition is a key feature dictating the success of pathogen colonization and infection. Pathogens scavenging iron from the host must contend with other members of the microbiome similarly competing for the limited pool of bioavailable iron, often in the form of heme. In this study, we identify a beneficial role for the heme-binding protein hemophilin (Hpl) produced by the non-pathogenic bacterium Haemophilus haemolyticus against its close relative, the opportunistic respiratory tract pathogen non-typeable Haemophilus influenzae (NTHi). Using a mouse model, we found that pre-exposure to H. haemolyticus significantly reduced NTHi colonization of the upper airway and impaired NTHi infection of the lungs in an Hpl-dependent manner. Further, treatment with recombinant Hpl was sufficient to decrease airway burdens of NTHi without exacerbating lung immunopathology or systemic inflammation. Instead, mucosal production of the neutrophil chemokine CXCL2, lung myeloperoxidase, and serum pro-inflammatory cytokines IL-6 and TNFα were lower in Hpl-treated mice. Mechanistically, H. haemolyticus suppressed NTHi growth and adherence to human respiratory tract epithelial cells through the expression of Hpl, and recombinant Hpl could recapitulate these effects. Together, these findings indicate that heme sequestration by non-pathogenic, Hpl-producing H. haemolyticus is protective against NTHi colonization and infection.

IMPORTANCE

The microbiome provides a critical layer of protection against infection with bacterial pathogens. This protection is accomplished through a variety of mechanisms, including interference with pathogen growth and adherence to host cells. In terms of immune defense, another way to prevent pathogens from establishing infections is by limiting the availability of nutrients, referred to as nutritional immunity. Restricting pathogen access to iron is a central component of this approach. Here, we uncovered an example where these two strategies intersect to impede infection with the respiratory tract bacterial pathogen Haemophilus influenzae. Specifically, we find that a non-pathogenic (commensal) bacterium closely related to H. influenzae called Haemophilus haemolyticus improves protection against H. influenzae by limiting the ability of this pathogen to access iron. These findings suggest that beneficial members of the microbiome improve protection against pathogen infection by effectively contributing to host nutritional immunity.

Characteristics of Haemophilus influenzae carriage among healthy children in China: A meta-analysis

BACKGROUND

Haemophilus influenzae (Hi) commonly causes invasive and noninvasive bacterial infections. Nationwide investigation on the carriage characteristics of H influenzae in healthy children in China is lacking. We reviewed the prevalence of H influenzae infections in this population.

METHODS

PubMed, CNKI, Wanfang, VIP, and CBM databases were electronically searched to collect cross-sectional studies on the prevalence of Hi among healthy children in China from inception to November 2021. Two reviewers independently screened the literature, extracted the data, and assessed the risk of bias in the included studies. Meta-analysis was performed using Stata 14.0.

RESULTS

A total of 28 studies involving 14,301 children were included, among whom there were 2878 children with Hi. The pooled carriage rate of Hi was 0.21 (95% CI: 0.17-0.25). Subgroup analysis indicated no significant sex- or age-related differences. The proportion of Hi in winter (29%) was higher than that in other seasons. Results indicated significant differences among the provinces, with carriage proportions ranging from 0.11 to 0.60. The proportion of nontypeable H influenzae (NTHi) was higher than that of the capsular type. The proportion of Hib in the capsular type (2%) was higher than that in other serotypes.

CONCLUSIONS

The carriage rate of Hi in healthy children in China was 21% with no sex-related age differences. The proportion of Hi in winter was high, and the proportions of Hi in different regions were significantly different. NTHi was the predominant serotype detected in children.

The Enolase of the Haemophilus influenzae Mediates Binding to Collagens: An Extracellular Matrix Component

Enolase proteins play a significant role as moonlighting proteins. In their role as surface-associated enolase, they have multiple functions as they interact with extracellular matrix proteins. Type I and III collagens are the major constituents of this extracellular matrix, and collagen is one of the targets of interaction with the enolase of many pathogens, thereby helping the colonization process and promoting the subsequent invasion of the host. This work aimed to determine the participation of non-typeable H. influenzae enolase as a collagen-binding protein. In this study, through the use of in vitro tests it was demonstrated that recombinant enolase of non-typeable H. influenzae (rNTHiENO) strongly binds to type I collagen. Using molecular docking, the residues that could take part in the interaction of non-typeable H. influenzae enolase-type I collagen (NTHiENO-Cln I) and non-typeable H. influenzae enolase-type III collagen (NTHiENO-Cln III) were identified. However, in vitro assays show that NTHiENO has a better affinity to interact with Cln I, concerning type Cln III. The interaction of NTHiENO with collagen could play a significant role in the colonization process; this would allow H. influenzae to increase its virulence factors and strengthen its pathogenesis.

Adaptation of Nontypeable Haemophilus influenzae in Human Airways in COPD: Genome Rearrangements and Modulation of Expression of HMW1 and HMW2

Chronic obstructive pulmonary disease (COPD) is a common debilitating disorder that is the third most common cause of death globally. Chronic lower airway infection by nontypeable Haemophilus influenzae (NTHi) in adults with COPD increases airway inflammation, causes increased symptoms, and accelerates progressive loss of lung function. Little is known about the mechanisms by which NTHi survives in COPD airways. To explore this question, the present study analyzes, in detail, 14 prospectively collected, serial isolates of a strain that persisted for 543 days in a patient with COPD, including analysis of four gap-free complete genomes. The NTHi genome underwent inversion of a ~400-kb segment three times during persistence. This inversion event resulted in switching of expression of the HMW1A and HMW2A adhesins as the inversion sites are in the promoter regions of HMW1 and HMW2. Regulation of the level of expression of HMW 1 and HMW2 in the human airways was controlled by the ~400-kb inversion and by 7-bp repeats in the HMW promoters. Analysis of knockout mutants of the persistent strain demonstrated that HMW1 and HMW2 proteins both function in the adherence of NTHi to human respiratory epithelial cells during persistence and that HMW1 also facilitates invasion of epithelial cells. An inverse relationship between biofilm formation and HMW1 expression was observed during persistence. This work advances understanding of the mechanisms of persistence of NTHi in COPD airways, which can inform the development of novel interventions to treat and prevent chronic NTHi infection in COPD. IMPORTANCE Nontypeable Haemophilus influenzae (NTHi) persists in the lower airways of adults with chronic obstructive pulmonary disease (COPD) for months to years, increasing airway inflammation that accelerates the progressive loss of lung function. Understanding the mechanisms of persistence in human airways by NTHi is critical in developing novel interventions. Here, in detail, we studied longitudinally collected sequential isolates of a strain of NTHi that persisted in an adult with COPD, including analysis of four gap-free genomes and knockout mutants to elucidate how the genome adapts in human airways. The NTHi genome underwent a genome rearrangement during persistence and this inversion impacted regulation of expression of key virulence phenotypes, including adherence to respiratory epithelial cells, invasion of epithelial cells and biofilm formation. These novel observations advance our understanding of the mechanisms of persistence of NTHi in the airways of adults with COPD.

Pleural thickening induced by Glaesserella parasuis infection was linked to increased collagen and elastin

Glaesserella parasuis is well-known for causing Glässer’s disease, which costs the worldwide swine industry millions of dollars each year. It has been reported the symptom of pleural thickening during Glässer’s disease but this symptom has received little attention. And there is no research on the elements which promote pleural thickening. In this study, pleural thickening was discovered to be associated with increased collagen fibers and elastic fibers. Furthermore, collagen-I and elastin were found to be up-regulated and concentrated in the pleura at the mRNA and protein levels following infection. To summarize, our findings add to the theoretical understanding of Glässer’s disease and provide strong support for further research into the pathogenic mechanism of Glaesserella parasuis and the program’s target treatment.

Development and multimodal characterization of an elastase-induced emphysema mouse disease model for the COPD frequent bacterial exacerbator phenotype

Chronic obstructive pulmonary disease (COPD) patients undergo infectious exacerbations whose frequency identifies a clinically meaningful phenotype. Mouse models have been mostly used to separately study both COPD and the infectious processes, but a reliable model of the COPD frequent exacerbator phenotype is still lacking. Accordingly, we first established a model of single bacterial exacerbation by nontypeable Haemophilus influenzae (NTHi) infection on mice with emphysema-like lesions. We characterized this single exacerbation model combining both noninvasive in vivo imaging and ex vivo techniques, obtaining longitudinal information about bacterial load and the extent of the developing lesions and host responses. Bacterial load disappeared 48 hours post-infection (hpi). However, lung recovery, measured using tests of pulmonary function and the disappearance of lung inflammation as revealed by micro-computed X-ray tomography, was delayed until 3 weeks post-infection (wpi). Then, to emulate the frequent exacerbator phenotype, we performed two recurrent episodes of NTHi infection on the emphysematous murine lung. Consistent with the amplified infectious insult, bacterial load reduction was now observed 96 hpi, and lung function recovery and disappearance of lesions on anatomical lung images did not happen until 12 wpi. Finally, as a proof of principle of the use of the model, we showed that azithromycin successfully cleared the recurrent infection, confirming this macrolide utility to ameliorate infectious exacerbation. In conclusion, we present a mouse model of recurrent bacterial infection of the emphysematous lung, aimed to facilitate investigating the COPD frequent exacerbator phenotype by providing complementary, dynamic information of both infectious and inflammatory processes.

The Usefulness of a Transbronchial Lung Cryobiopsy for Diffuse Bronchiolitis

We herein report four cases of diffuse bronchiolitis proven by a transbronchial lung cryobiopsy (TBLC). Based on various aspects, including the pathological findings, we definitively diagnosed two patients with diffuse panbronchiolitis (DPB) and the other two with primary ciliary dyskinesia (PCD). One of the DPB patients had more severe peribronchiolar fibrosis than the other, and the disease course was refractory to macrolide therapy. One of the PCD patients was additionally diagnosed with combined constrictive bronchiolitis. This report highlights the importance of a TBLC in the differentiation of bronchiolitis, suggesting its utility for helping pulmonologists formulate a treatment strategy.

The importance of intracellular bacterial biofilm in infectious diseases

Various bacterial species, previously known as extracellular pathogens, can reside inside different host cells by adapting to intracellular modes by forming microbial aggregates with similar characteristics to bacterial biofilms. Additionally, bacterial invasion of human cells leads to failure in antibiotic therapy, as most conventional anti-bacterial agents cannot reach intracellular biofilm in normal concentrations. Various studies have shown that bacteria such as uropathogenic Escherichia coli, Pseudomonas aeruginosa, Borrelia burgdorferi,Moraxella catarrhalis, non-typeable Haemophilus influenzae, Streptococcus pneumonia, and group A Streptococci produce biofilm-like structures within the host cells. For the first time in this review, we will describe and discuss the new information about intracellular bacterial biofilm formation and its importance in bacterial infectious diseases.

Diffuse panbronchiolitis research in MEDLINE (1969-2017): Report of a bibliometric analysis

BACKGROUND

Given the well documented and undesired impact of diffuse panbronchiolitis (DPB), there is a need to create a statistical inventory of research output on DPB. The aim of this study was to identify and analyze different trends in publication over time, with technological additions.

METHODS

Articles indexed in MEDLINE regarding DPB were retrieved using PubMed. Citation results were categorized by article type, year of publication, language, and country.

RESULTS

A total of 657 publications, published between 1969 and 2017 were retrieved from PubMed; the year with the highest number of articles published was 1992 (n = 32). Japan accounted for 68.34% (n = 449) publications, followed by the United States of America (USA; 6.70%, n = 44) and China (5.48%, n = 36). English (n = 401) was the most commonly used language in the publications, followed by Japanese (n = 223) and Chinese (n = 16). Articles were published in 218 different journals; The Japanese Journal of Thoracic Diseases published the maximum number of articles, accounting for 13.7% (n = 90) citations. Sugiyama Y was the most productive author and contributed to 12 publications.

CONCLUSIONS

This was the first bibliometric analysis of DPB. Between 1991 and 2000, the number of publications on DPB literature reached a peak, and although the frequency of publication has decreased recently, the quantity of DPB research during the past 48 years is adequate and satisfactory. Overall, the publications on DPB have undergone exponential growth over the last 30 years.

Treatment of otitis media by transtympanic delivery of antibiotics

Otitis media is the most common reason U.S. children receive antibiotics. The requisite 7- to 10-day course of oral antibiotics can be challenging to deliver in children, entails potential systemic toxicity, and encourages selection of antimicrobial-resistant bacteria. We developed a drug delivery system that, when applied once to the tympanic membrane through the external auditory canal, delivers an entire course of antimicrobial therapy to the middle ear. A pentablock copolymer poloxamer 407-polybutylphosphoester (P407-PBP) was designed to flow easily during application and then to form a mechanically strong hydrogel on the tympanic membrane. U.S. Food and Drug Administration-approved chemical permeation enhancers within the hydrogel assisted flux of the antibiotic ciprofloxacin across the membrane. This drug delivery system completely eradicated otitis media from nontypable Haemophilus influenzae (NTHi) in 10 of 10 chinchillas, whereas only 62.5% of animals receiving 1% ciprofloxacin alone had cleared the infection by day 7. The hydrogel system was biocompatible in the ear, and ciprofloxacin was undetectable systemically (in blood), confirming local drug delivery and activity. This fast-gelling hydrogel could improve compliance, minimize side effects, and prevent systemic distribution of antibiotics in one of the most common pediatric illnesses, possibly minimizing the development of antibiotic resistance.

[Evaluation of safety of haemophilus influenza type b(Hib) conjugate vaccine in postmarketing based on the immunization information management system]

OBJECTIVE

To analyze the occurrence feature of adverse events following immunization (AEFI) of Hib conjugate vaccine (HibCV) and to evaluate the safety of HibCV in postmarketing.

METHODS

2008-2013 HibCV AEFI data were collected through national AEFI information management system, which were downloaded in March 18, 2014.The demographic information and inoculation quantity of HibCV were from Immunization information management system in Jiangsu province. The incidence rate and 95% CI value of AEFI, common vaccine reaction and rare vaccine reaction following immunization of HibCV were calculated. The differences in the incidence rate of common vaccine reaction and rare vaccine reaction among sex, months of age, and number of injections were compared by means of (χ² tests.

RESULTS

A total of 6.16 million doses of vaccine were administered in Jiangsu province during 2008-2013, and 4 718 vaccinees reported having adverse event, for a rate of 76.60/100 000 (95% CI: 74.42/100 000-78.79/100 000). The incidence rate of common vaccine reaction and rare vaccine reaction was 71.10/100 000 (95% CI: 68.99/100 000-73.20/100 000) and 5.16/100 000 (95% CI: 4.60/100 000-5.73/100 000), respectively. The main symptoms of common vaccine reactions were fever, swelling, indurations and gastrointestinal reactions. The incidence rates of them were 40.54/100 000, 35.09/100 000, 12.94/100 000 and 0.36/100 000 in turn. The main symptoms of rare vaccine reactions were anaphylactic rashes and angioedema, the incidence rates of which were 4.77/100 000 and 0.15/100 000 respectively. 91.39% (4 002/4 379) of common vaccine reactions and 88.36% (281/318) of rare vaccine reactions happened within 1 d after vaccination. Anaphylactic shock (3 cases) and laryngeal edema (1 case) all happened within 1 d after vaccination. The incidence rate of common vaccine reactions among boys (79.72/100 000, 2 641/3 313 071) was higher than that of girls (61.07/100 000, 1 738/2 846 001) (χ² = 74.92, P < 0.001). The incidence rate of common vaccine reactions among children aged ≥ 12 month-old (86.82/100 000, 2 200/2 533 949) was higher than that among children aged 2-11 month-old (60.11/100 000, 2 179/3 625 123) (χ² = 149.79, P < 0.001). The incidence rate of common vaccine reactions in children vaccinated the first dose (78.93/100 000, 2 666/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (61.59/100 000, 1 713/2 781 458) (χ² = 64.59, P < 0.001). The incidence rate of rare vaccine reactions in children vaccinated the first dose (6.69/100 000, 226/3 377 614) was higher than that in children vaccinated the second or third or fourth dose (3.31/100 000, 92/2 781 458) (χ² = 33.82, P < 0.001).

CONCLUSION

The safety of HibCV among children was relative good. However, the surveillance should still focus on the anaphylactoid reactions of anaphylactic shock and laryngeal edema after HibCV immunization.

The PilA protein of non-typeable Haemophilus influenzae plays a role in biofilm formation, adherence to epithelial cells and colonization of the mammalian upper respiratory tract

We recently described the expression of type IV pili (Tfp) by non-typeable Haemophilus influenzae (NTHI), a common respiratory tract pathogen. Prior to that report, Tfp were not thought to be produced by NTHI as they are not observed on NTHI when grown on chocolate agar or other commonly used growth media. To further characterize growth conditions permissive for the expression of NTHI Tfp, as well as determine their role in colonization and virulence, we transformed an NTHI otitis media isolate with a reporter plasmid containing the lux gene cluster driven by the pilA promoter. Transcription from the pilA promoter was demonstrated under a variety of in vitro growth conditions and, importantly, by ex vivo imaging of luciferase-producing NTHI in infected chinchillas. Luciferase-producing NTHI were also identified within a biofilm formed by NTHI in vivo. We further demonstrated a role for NTHI PilA in adherence to human respiratory epithelial cells, in colonization of the chinchilla respiratory tract as well as a requirement for PilA in biofilm development, both in vitro and in vivo. Collectively, our data demonstrate that NTHI express PilA in vivo, and that PilA plays an important role in the pathogenesis of an upper respiratory tract infection induced by NTHI.

[Survey of nasopharyngeal carriage of Haemophilus influenzae and Streptococcus pneumoniae in infants at day care centers]

Infants at day care centers tend to contract repetitive upper respiratory infections and prolonged otitis media. The increase in antimicrobial-resistant bacteria, particularly in infants, has given rise to a stubborn therapeutic problem. We studied the nasopharyngeal carriage and drug resistance to Haemophilus influenzae (H. influenzae) and Streptococcus pneumoniae (S. pneumoniae), the most common pathogens of upper respiratory infections, in infants at day care centers. Nasopharyngeal cultures of infants between the ages of 0 and 6 years were conducted at two day care centers in July 2004 ("summer"; n=183), and in February 2005 ("winter"; n=182). Isolated H. influenzae and S. pneumoniae were subjected to antibiotic susceptibility tests by broth microdilution. We also conducted an otolaryngological examination and a survey on past and life histories. H. influenzae in summer (38.3%) increased significantly in winter (57.7%). Beta-lactamase-negative and positive ampicillin-resistant H. influenzae (BLNAR+ BLPAR) in summer decreased significantly in winter. S. pneumoniae did not differ in summer (42.1%) or in winter (43.4%). Penicillin-resistant and intermediate S. pneumoniae (PRSP+PISP) was 41.3% in summer and decreased significantly to 19.0% in winter. BLNAR + BLPAR and PRSP + PISP differed with the day care center. In otolaryngological examination, rhinosinusitis was commonest (28.4% in summer and 30.8% in winter), followed by allergic rhinitis (8.7% in summer and 6.0% in winter) and otitis media (8.2% in summer and 6.0% in winter). Tonsillitis was minor (0.5% in both seasons). Rhinosinusitis in winter was significantly higher in carriers of H. influenzae and/or S. pneumoniae than in non carriers (36.4% versus 16.0%). Breast-fed infants tended to have less otitis media than bottle-fed infants (38.2% versus 52.9%). H. influenzae and/or S. pneumoniae plateaued (75-80%) after 12 months in day care centers. These results suggest that infants attending day care centers are immediately colonized by H. influenzae and S. pneumoniae in the nasopharynx after entering the centers. Nasopharyngeal drug-resistant H. influenzae and S. pneumoniae varied during the seasons and between day care centers. Further prospective studies are needed to determine upper respiratory tract infection in infants at day care centers and to evaluate carriage, epidemiology, and the drug-resistance rates of these pathogens.

An unusual presentation of sphenoid sinusitis with septicaemia in a healthy young adult

Streptococcus pneumonia and Haemophilus influenzae account for more than 50% of bacterial acute sinusitis. Isolated sphenoid sinusitis is a rare disease with potentially devastating complications such as cranial nerve involvement, brain abscess, and meningitis. It occurs at an incidence of about 2.7% of all sinus infections. There have been no previous reported cases of unilateral sphenoid sinusitis presenting as septicaemia in an otherwise healthy young immunocompetent adult.

[A case of pulmonary abscess in which Haemophilus parainfluenzae and Streptococcus intermedius were isolated by percutaneous needle aspiration]

Some microbes, including the Bacteroides species, Staphylococcus aureus and Streptococcus milleri groups, can cause pulmonary abscess. Haemophilus parainfluenzae is usually categorized as one of the normal flora which colonizes in the ears and the nasopharynx, and it has been long considered that H. parainfluenzae has little pathogenicity in the lower respiratory tract and lung parenchymal. In this report, we present a case of pulmonary abscess caused by both H. parainfluenzae and Streptococcus intermedius. The patient was a 75-year-old man who had had total esophageo-gastrectomy because of esophageal cancer. He presented with purulent sputum, and chest X-ray film showed a dense consolidation in the right upper lung field. CT-guided transcutaneous fine needle aspiration was performed as a diagnostic procedure. Since both H. parainfluenzae and S. intermedius had been isolated from the lesion, pulmonary abscess caused by these two pathogens was diagnosed. The patient was treated with panipenem/betamipron, and his symptoms and pulmonary infiltrates on the chest X-ray film improved thereafter. So far, very few cases have been reported in which H. parainfluenzae caused lower respiratory tract infection. Although S. intermedius is known as one of the pathogens of pulmonary abscess, it is possible that H. parainfluenzae could also be pathogenic in infectious diseases of the lung.

Haemophilus influenzae pericarditis with tamponade as the initial presentation of systemic lupus erythematosus

Although cardiac tamponade is an important and emergent complication of systemic lupus erythematosus (SLE), purulent pericarditis is rare despite the high frequency of pericardial effusion in SLE. We describe the first SLE case of Haemophilus influenzae type-f pericarditis with cardiac tamponade with SLE as the initial presentation. The pathophysiology and therapy are discussed.

[The effect of routine vaccination in the Czech Republic on the incidence of invasive diseases caused by Haemophilus influenzae b]

OBJECTIVES

The paper is an analysis of the results of a five-year surveillance programme in the Czech Republic (1999-2003); it evaluates the efficacy of routine Hib vaccination that started in July 2001.

MATERIAL AND METHODS

Morbidity due to Hib was explored in a surveillance programme, which since 2002 also included the investigation of Hib vaccine failure. Hib identification was carried out with standard methods, serotypes were verified using PCR, biotyping was carried out in all strains and in selected strains also multilocus sequential typing.

RESULTS

In the years 1999-2003 invasive Hib disease presented mostly as meningitis, followed by epiglottitis. Mortality due to an invasive Hib disease was in the years 1999-2003 2.3 %. Among the Hib strains isolated in invasive disorders predominated the biotype I and the sequence type ST-6.

CONCLUSIONS

Following the introduction of routine Hib vaccination in the Czech Republic there was an overall drop in morbidity due to Hib invasive disorders. This was most obvious in a decrease in the morbidity of Hib meningitis and in the vaccinated age group. Two years after the introduction of routine Hib vaccination morbidity dropped by 81 % in children aged 0 to 1 year. In higher age groups there was no change in the number of invasive Hib disease. Neither was there an increase in "non-b" haemophilus invasive disorders. Failure of Hib vaccination is a rare occurence.

[Acute purulent pericarditis due to Haemophilus influenzae treated successfully with subxiphoid pericardial drainage; report of a case]

A surgical case of acute purulent pericarditis in 1-year 2-month old boy who developed pericardial tamponade rapidly is reported. A subxiphoid pericardiectomy through a median incision was performed. Haemophilus influenzae was isolated from the effusion. He recovered successfully with an administration of antibiotics after the drainage procedures and did not develop constructive pericarditis. Our experience suggested that early subxiphoid pericardial drainage was effective in treatment of acute purulent pericarditis.

Haemophilus influenzae acute pyelonephritis in the elderly

Haemophilus influenzae has rarely been implicated as the causative agent of urinary tract infections in adults. We report a case of H. influenzae pyelonephritis in a 78-year old man with benign prostatic hyperplasia and discuss the possible underestimation of the true incidence of H. influenzae in adult urinary tract infections.

Observations on the carriage of pneumococci by patients with chronic bronchitis, and their families

Previous workers (Stuart-Harris, Pownall, Scothorne & Franks, 1953; May, 1953)have reported studies on the bacterial flora of the sputum in cases of chronic bronchitis. Both pneumococci and Haemophilus influenzae have been reported frequently in the sputum but the source of these organisms, which might be either the patient's own upper respiratory tract or the environment, has not been traced.A long-term study of individuals with and without chronic bronchitis and of their families was therefore begun in an attempt to discern the role of exogenous infection in this disease. Observations were limited to the pneumococcus because serological identification of individual strains was readily possible in this species.

[A case of pyogenic vertebral osteomyelitis caused by Haemophilus aphrophilus]

On Aug. 3, 1999, a 73-year-old male was admitted to our hospital with the chief complaint of pain in the neck, high fever, and numbness in the arm. MRI of the cervix showed high intensity at the C3/C4 disc space. Laboratory data showed several signs of inflammation. Haemophilus aphrophilus was detected from the specimen of the disc space, and the diagnosis of pyogenic vertebral osteomyelitis caused by H. aphrophilus was made. After the identification of H. aphrophilus, antibiotic therapy with Cefotiam (2 g/day) was given but his vertebral collapsed. Surgical treatment consisted of curettage and anterior spinal body fusion using the iliac bone, was performed on his 23rd hospital day, successfully. The antibiotic therapy of Cefazolin (2 g/day) was continued for the first 3 days, followed by Cefotiam (2 g/day) and later Levofloxacin (300 mg/day). The patient was discharged on the 88th hospital day. The origin of infecting H. aphrophilus in this patient was not clear, but oral source was suspected. We reported the first case of pyogenic vertebral osteomyelitis caused by H. aphrophilus in Japan.

Polyp and fibrous adhesion formation in acute otitis media caused by non-typeable or type b Haemophilus influenzae or Moraxella catarrhalis

Among a variety of other histopathologic changes, polyps and fibrous adhesions are readily formed in the middle ear mucosa during experimental acute otitis media (AOM) caused by Streptococcus pneumoniae. Quantitative studies on experimental AOM caused by other bacteria have shown that some of these histopathologic changes, such as adaptive bone modeling and increase in goblet cell density, differ according to the type of bacteria. This investigation surveys polyp and fibrous adhesion formation in experimental AOM caused by either non-typeable or type b Haemophilus influenzae, or Moraxella catarrhalis. Seventy-five rats were inoculated with 1 of these 3 bacteria (25 rats in each of 3 groups). Five rats from each group were sacrificed on days 4, 8, 16, 60 and 180 post-inoculation. The middle ear mucosae were dissected and histopathologic changes in whole-mount and section preparations were studied using light microscopy. Polyps were found in most ears and in the greatest numbers on the early days; fewer polyps were found on the later days, regardless of the type of bacteria. However, non-typeable and type b H. influenzae induced formation of significantly more polyps than M. catarrhalis. The polyps were primarily located in the epitympanum. Fibrous adhesions were primarily located in the hypotympanum and formed in almost all ears, on all days post-inoculation, regardless of the type of bacteria. Numbers increased to a peak on day 16 and then decreased. Non-typeable and type b H. influenzae induced formation of significantly more adhesions than M. catarrhalis, and the middle ears displayed a higher number of persisting adhesions in the animals inoculated with non-typeable H. influenzae. We conclude that polyps and adhesions are formed in experimental AOM regardless of bacterial type, confirming a pathogenesis based on inflammation. Both types of H. influenzae induce formation of greater numbers of polyps/adhesions than M. catarrhalis, and the non-typeable form causes more adhesive sequelae in the mucosa than the encapsulated type b.

Adaptive bone modeling and remodeling in acute otitis media caused by non-typeable or type B Haemophilus influenzae or Moraxella catarrhalis

Experimental studies have shown that acute otitis media caused by Streptococcus pneumoniae alters modeling dynamics in bone tissue structures surrounding the middle ear cavity. Initial resorption of bone is followed by formative activity, seen as massive osteoneogenesis. However, neither resorptive nor formative activity occurs in the otic capsule, supporting the existence of a perilymphatic zone of specialized bone. This study investigates adaptive bone modeling in acute otitis media caused by other bacteria frequently encountered in this disease. Seventy-five rats were inoculated with either non-typeable or type b Haemophilus influenzae, or Moraxella catarrhalis (25 rats in each group). Five rats from each group were sacrificed on days 4, 8, 16, 60 and 180 post-inoculation. Qualitative as well as quantitative histopathology revealed increasing apposition of new bone on both sides of the original bony wall of the middle ear bulla, i.e. at the inner and outer periosteum. Remodeling activity was seen on later days of sacrifice, as typical osteone (Haversian system) formation. Measured bone thickness in four anatomically well-defined localities progressed to a peak 2 months post-inoculation, followed by some degree of normalization. However, bone thickness was still massively increased 6 months after the acute incident. Except in the otic capsule, resorptive and formative activity was found in all bone tissue structures surrounding the middle ear cavity. These findings were irrespective of the type of inoculated bacteria. However, non-typeable or type b Haemophilus influenzae induces significantly more new bone formation than Moraxella catarrhalis. We conclude that acute otitis media caused by either of the bacteria is accompanied by massive and progressive net osteoneogenesis, already evident on day 4 and peaking 2 months post-inoculation, followed by some degree of normalization. Non-typeable and type b Haemophilus influenzae induce more new bone formation than Moraxella catarrhalis, whereas other features of bone histomorphology were equivalent. The present findings further support the existence of a perilymphatic zone of specialized bone.

Noninvasive fluorescent identification of bacteria causing acute otitis media in a chinchilla model

OBJECTIVES

To evaluate a noninvasive method of bacterial identification via fluorescence spectroscopy in the setting of acute otitis media in a chinchilla model.

STUDY DESIGN

Prospective.

METHODS

For each chinchilla, transbullar inoculation with Streptococcus pneumoniae, Haemophilus influenzae, or Staphylococcus aureus was performed bilaterally and clinical infection was determined by otoscopy. An optical fiber coupled to a spectrofluorometer allowed for the delivery of an excitation wavelength to the inflamed tympanic membrane and the acquisition of the resulting emission signal. Sequential emission spectra obtained over a range of excitation wavelengths were assembled by a computer algorithm, and a single, three-dimensional plot was created for each test ear. Similarly, plots from the healthy external auditory canal (EAC) were also recorded. Twelve animals were used to establish a library of four reference plots representing the three bacteria and the EAC. Of the 24 ears available for study, 10 were excluded from analysis because of lack of clinical infection or presence of tympanic membrane perforation with purulent drainage. From four additional animals, four samples from ears infected with the above bacteria and three samples of the EAC served as unknowns. The unknown plots were analyzed by an investigator blinded to their identity.

RESULTS

Using a multiple correlation of the unknown to the reference plots, seven of seven samples were correctly identified.

CONCLUSIONS

We were able to establish a prototype method for the noninvasive identification of a limited library of pathogens in a chinchilla model of acute otitis media.

The structural heterogeneity of the lipooligosaccharide (LOS) expressed by pathogenic non-typeable Haemophilus influenzae strain NTHi 9274

Nontypeable Haemophilus influenzae (NTHi) is an important pathogen responsible for otitis media in children and of pneumonitis in adults with depressed resistance. NTHi is acapsular and, therefore, capsular polysaccharide-based vaccines are ineffective for preventing infections by this pathogen. Recently it was found that a detoxified lipooligo-saccharide (LOS) conjugate from NTHi 9274 induced bactericidal antibodies effective against a large number of NTHi isolates, and conferred protection against NTHi otitis media in chinchillas (X.-X.Gu et al., 1996, Infect. Immun.,64, 4047-4053; X. -X.Gu et al., 1997., Infect. Immun.,65, 4488-4493). In this paper we report the chemical character-ization of the LOS from NTHi 9274 LOS. NTHi is capable of expressing a heterogenous population of LOS exhibited by multiple oligosaccharide (OS) epitopes. OSs released from the LOS of NTHi 9274 by mild acid hydrolysis were purified using Bio-Gel P4 gel permeation chromatography. The OSs were characterized by glycosyl composition analysis, glycosyl linkage analysis, nuclear magnetic resonance spectroscopy (NMR), fast atom bombardment mass spectro-metry (FAB-MS), matrix-assisted laser desorption time of flight mass spectro-metry (MALDITOF-MS), and tandem MS/MS. At least 17 different OS molecules were observed. These contained variable glycosyl residues, phosphate (P), and phospho-ethanolamine (PEA) substituents. These molecules contained either three, four, or five hexoses, and all contained four heptosyl residues. The four heptosyl residues consisted of one D,D-Hep and three L,D-Hep. Dephosphorylation of the OSs with aqueous 48% hydrofluoric acid (HF) reduced the number of molecules to about to seven; Hex(1)-(7)Hep(4)Kdo(1). Of these seven, Hex(2)Hep(4)Kdo(1), Hex(3)Hep(4)Kdo(1), and Hex(4)Hep(4)Kdo(1)were the major constituents. Thus, this NTHi LOS preparation is very heterogeneous, and contains structures different from those previously published for Haemophilus influenzae. The tandem MS/MS analysis and glycosyl linkage data suggest that the LOS oligosaccharides have the following structures where Hex is either a Glc or Gal residue.

[Acute epiglottitis in children: current criteria for the diagnosis and treatment]

Acute epiglottitis is still a potentially lethal pathology, particularly in early childhood. The present study involves seven cases of acute epiglottitis in children under 4 years of age. The authors describe the diagnostic and therapeutic protocols used in these pediatric patients placing particular emphasis on the use of endoscopy and the need for prompt hospitalization in an intensive care unit to best integrate the diagnostic approach with therapeutic treatment.

The isolation and identification of Haemophilus spp, from unusual lesions in children

From a high proportion of children sent to hospital H. influenzae can be isolated if suitable culture media are used. A number of H. influenzae strains were isolated from unusual sites, such as (1) blood cultures after tonsillectomy or tonsillotomy in five cases; (2) urine or the urinary tract in eight cases; (3) the lumen of appendices removed at operation in 11 cases (4%); (4) osteomyelitis or pyarthrosis in six cases; (5) miscellaneous infections including two perianal abscesses, three cases of paronychia, one infected thyroglossal cyst, and several skin infections.It is suggested that infections of the skeletal system and the urinary tract arise from haematogenous spread of H. influenzae, as demonstrated by positive blood cultures after tonsillectomy and in two cases of skeletal infection. Infection of the appendix, perianal abscesses, paronychia, and skin infections probably arise by the direct route, either by immediate contact or by passage of viable organisms through the alimentary canal.