Haemophilus influenzae biochemotyping

Biochemotyping was performed in 129 strains of Haemophilus influenzae. 95% of strains could be assigned to one of the five biochemotypes proposed by Kilian. Most of the serotype B strains isolated in meningitis belonged to biochemotype I. The biochemical differentiation of Haemophilus influenzae is regarded as a reliable technique deserving further application.     

流感嗜血杆菌的分型研究

目的分析同济医院分离的流感嗜血杆菌的生物学分型及荚膜基因分型,了解本地区分离的流感嗜血杆菌的主要流行株。方法2012年1月1日至2012年12月31日从华中科技大学同济医学院附属同济医院分离流感嗜血杆菌100株。根据脲酶、吲哚和鸟氨酸脱羧酶试验对流感嗜血杆菌进行传统的生物学分型,分为Ⅰ～Ⅷ八个生物型。回顾患者病史资料,分析生物学分型和流感嗜血杆菌所引起的疾病之间的关系。用流感嗜血杆菌荚膜编码基因（bexA）和a—f型特异性荚膜基因设计引物,采用PCR技术对流感嗜血杆菌进行荚膜基因检测。通过生物学分型和荚膜基因分型结果的比对,探讨两者之间的关联。结果分离的100株流感嗜血杆菌生物学分型结果如下：Ⅲ型6株,Ⅳ型28株,Ⅴ型1株,Ⅵ型54株,Ⅶ型11株。未分离到Ⅰ型、Ⅱ型和Ⅷ型。分析患者的临床诊断,发现主要流行株Ⅵ型流感嗜血杆菌主要引起患者肺炎（包括支气管肺炎和新生儿肺炎）和支气管炎（包括毛细支气管炎和喘息性支气管炎）。荚膜基因分型结果显示,未分离到b型和b-型流感嗜血杆菌。共分离到1株f型,其余99株均为无荚膜抗原的不可分型流感嗜血杆菌。生物学分型和荚膜分型之间无明显的相关性。结论该院分离的流感嗜血杆菌主要为生物型Ⅵ型。回顾患者病史,发现Ⅵ型主要引起肺炎和支气管炎。荚膜基因分型显示,本地区分离的流感嗜血杆菌主要为不可分型流感嗜血杆菌。生物学分型和荚膜基因分型之间无明显相关性。     

Haemophilus influenzae infection drives IL-17-mediated neutrophilic allergic airways disease

A subset of patients with stable asthma has prominent neutrophilic and reduced eosinophilic inflammation, which is associated with attenuated airways hyper-responsiveness (AHR). Haemophilus influenzae has been isolated from the airways of neutrophilic asthmatics; however, the nature of the association between infection and the development of neutrophilic asthma is not understood. Our aim was to investigate the effects of H. influenzae respiratory infection on the development of hallmark features of asthma in a mouse model of allergic airways disease (AAD). BALB/c mice were intraperitoneally sensitized to ovalbumin (OVA) and intranasally challenged with OVA 12-15 days later to induce AAD. Mice were infected with non-typeable H. influenzae during or 10 days after sensitization, and the effects of infection on the development of key features of AAD were assessed on day 16. T-helper 17 cells were enumerated by fluorescent-activated cell sorting and depleted with anti-IL-17 neutralizing antibody. We show that infection in AAD significantly reduced eosinophilic inflammation, OVA-induced IL-5, IL-13 and IFN-γ responses and AHR; however, infection increased airway neutrophil influx in response to OVA challenge. Augmented neutrophilic inflammation correlated with increased IL-17 responses and IL-17 expressing macrophages and neutrophils (early, innate) and T lymphocytes (late, adaptive) in the lung. Significantly, depletion of IL-17 completely abrogated infection-induced neutrophilic inflammation during AAD. In conclusion, H. influenzae infection synergizes with AAD to induce Th17 immune responses that drive the development of neutrophilic and suppress eosinophilic inflammation during AAD. This results in a phenotype that is similar to neutrophilic asthma. Infection-induced neutrophilic inflammation in AAD is mediated by IL-17 responses.     

Immunogenic outer-membrane proteins of Haemophilus influenzae type b in infection.

Outer-membrane proteins (OMPs) from Haemophilus influenzae type b (strain Eagan), grown both in vitro (broth) and in vivo (rat intra-peritoneal), were separated by SDS-PAGE. The major OMPs were present in both growth conditions although the amounts of OMP a and OMP d were reduced in rat-grown organisms. There were strong additional bands in in-vivo-grown organisms at 51 and 92 kDa. Antiserum was raised in rabbits against in-vivo-grown bacteria, and absorbed with lysates of in-vitro-grown bacteria. This serum was used in Western blot analysis of OMPs from in-vitro- and in-vivo-grown cells to identify immunogenic proteins present in infection. These infection-associated OMPs had apparent molecular masses of 43 kDa, 48 kDa, 81 kDa and greater than 200 kDa. Bands of reactivity, of the same molecular mass as some of these, were found on immunoblots when rat and human convalescent sera were used as the source of primary antibody. In particular, a band of 81 kDa was recognized by pooled rat and three human convalescent sera.     

Comparative evaluation of conjugate vaccines in the Haemophilus influenzae infection model

We used a murine model of Haemophilus influenzae type b (Hib) infection to analyze the immunologic response to two commercially available PRP conjugate vaccines (HbOC, PRP-T). The mortality rate in mice infected with a large dose of the bacteria after vaccination with HbOC or PRP-T at two and three doses was significantly lower than in non-vaccinated mice and mice vaccinated by one dose. Furthermore, for infections caused by a small bacterial dose, the mortality rate in mice vaccinated with one, two, or three doses was significantly lower than in non-vaccinated mice. The induction level of anti-PRP antibodies, especially IgG, in serum of mice vaccinated by two or three doses was higher than in those vaccinated with a single dose. Our results indicate that the dose of vaccine influences its efficacy in protecting against Hib infection. Our results also showed a lack of difference between two different PRP conjugate vaccines.     

Bacteriophage N3 of Haemophilus influenzae. IV. Intracellular events during infection by Haemophilus influenzae phage and transfection by its DNA

Intracellular events following infection of competent Haemophilus influenzae cells by N3 phage or transfection by DNA from phage were examined. After infection by whole phage three forms of intracellular phage DNA were observed by sedimentation velocity analysis. These forms are probably twisted circles, open circles and linear duplexes. In transfection only about 15% of the phage DNA is efficiently taken up by the competent cells. After entry of phage DNA into wild-type cells in transfection the DNA is degraded at early times, but later some of the fragments are reassembled, resulting in molecules that sediment faster than the monomer length of phage DNA. These presumably concatamer forms are generated by recombination. In strain rec-1 the fast-sedimenting molecules do not appear and degradation of phage DNA is even more pronounced than in the wild-type cells. Since rec-1 is transfected with much lower efficiency than the wild-type our hypothesis is that both fragmentation and generation of fast-sedimenting phage DNA by recombination are required for efficient transfection. These results also show that although phage N3 codes for its own recombination system it cannot operate in the early stages of transfection and succesful transfection is entirely dependent upon the host recombination system.     

Serotyping of Noncapsular Haemophilus influenzae

A microtechnique is described for agglutination typing of Haemophilus influenzae. It also provides a further means for classification and study of noncapsular type-specific strains.     

Automated Detection of Haemophilus influenzae

Addition of heme (X factor) and pyridine nucleotide (V factor) to the medium permits rapid growth of Haemophilus influenzae, with evolution of easily detectable amounts of (14)CO(2). Radiometric media containing X and V factor should be used when evaluating clinical specimens which might contain Haemophilus species.     

Electron microscopy of Haemophilus influenzae

The electron microscopic study of H. influenzae standard strains, serovar b, in the capsular and noncapsular forms has revealed the pronounced pleomorphism of these organisms in successive generations.     

New Bacteriophage of Haemophilus influenzae

Some properties of a newly isolated Haemophilus influenzae bacteriophage are described. The phage is morphologically distinct from previously described H. influenzae phages.     

Haemophilus influenzae Type B Septicaemia

In the period November 1967 to September 1968 Haemophilus influenzae type b was isolated from the blood of 11 young children. Only three of these presented with meningitis; others had septic arthritis, oesteomyelitis, subcutaneous abscesses, cellulitis, respiratory infections, and undifferentiated pyrexia. During the preceding five years H. influenzae type b was isolated from the blood cultures of 15 patients, and all but two of these were cases of meningitis. Blood culture has proved of value in establishing the role of H. influenzae type b in a broad spectrum of acute infections, and the suggestion is made that meningitis may represent only a minority of cases of haemophilus septicaemia. Because H. influenzae is resistant to some antibiotics bacteriological diagnosis of such cases is important if the correct treatment is to be given.