Intralitter Transmission of Haemophilus influenzae Type b in Infant Rats and Rifampin Eradication of Nasopharyngeal Colonization

Halsey, Neal A.; Korock, C.; Johansen, T. L.; Glodé, Mary P.

doi:10.1093/infdis/142.5.739

Cited by 19 publications

(11 citation statements)

References 14 publications

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“…In one set of studies, influenza increased pneumococcal titers in the directly inoculated donor, or index, mice (26), and increasing these bacterial numbers by neutrophil depletion was sufficient to promote transmission to influenza-infected recipient, or contact, mice (105). Earlier, more observational transmission models in infant rodents for pneumococci (61) and H. influenzae (32) suggested that influenza was not absolutely required for transmission. More recent studies have suggested that influenza coinfection leads to increased transmission not because of higher bacterial titers in the donor mice but rather because of increased shedding from donor mice (99).…”

Section: Transmissionmentioning

confidence: 99%

See 1 more Smart Citation

Mechanisms of Bacterial Colonization of the Respiratory Tract

Siegel¹,

Weiser²

2015

Annu. Rev. Microbiol.

164

123

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Respiratory tract infections are an important cause of morbidity and mortality worldwide. Chief among these are infections involving the lower airways. The opportunistic bacterial pathogens responsible for most cases of pneumonia can cause a range of local and invasive infections. However, bacterial colonization (or carriage) in the upper airway is the prerequisite of all these infections. Successful colonizers must attach to the epithelial lining, grow on the nutrient-limited mucosal surface, evade the host immune response, and transmit to a susceptible host. Here, we review the molecular mechanisms underlying these conserved stages of carriage. We also examine how the demands of colonization influence progression to disease. A range of bacteria can colonize the upper airway; nevertheless, we focus on strategies shared by many respiratory tract opportunistic pathogens. Understanding colonization opens a window to the evolutionary pressures these pathogens face within their animal hosts and that have selected for attributes that contribute to virulence and pathogenesis.

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Section: Transmissionmentioning

confidence: 99%

“…H. influenzae , however, was also transmitted among weaned rats, demonstrating that the presence of the dam is not required for at least some transmission models (32). Other studies have physically separated donor and recipient animals, demonstrating that airborne transmission can occur without direct contact (11, 70).…”

Section: Transmissionmentioning

confidence: 99%

Mechanisms of Bacterial Colonization of the Respiratory Tract

Siegel¹,

Weiser²

2015

Annu. Rev. Microbiol.

164

123

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“…The encapsulated, type b organism is a major cause of invasive bacterial disease in infants and young children, while the non-typable organism is a common agent in local respiratory tract disease, such as otitis media and sinusitis. The initial event in the pathogenesis of both local disease with non-typable H. influenzae and systemic disease with the type b organism appears to be respiratory tract colonization (7). Prerequisite to the establishment of H. influenzae mucosal colonization is the adherence of the organisms to respiratory epithelial cells (8).…”

Section: Introductionmentioning

confidence: 99%

Adherence of Haemophilus influenzae to Human Epithelial Cells

Gilsdorf

Ferrieri

1984

Scandinavian Journal of Infectious Diseases

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Haemophilus influenzae organisms, both type b and non-typable strains, were tested for their adherence to human buccal epithelial cells. Adherence was determined by visual examination of gram-stained specimens of epithelial cells following incubation with H. influenzae. Among 36 isolates tested, 2 organisms adhered well to buccal cells; a type b nasopharyngeal isolate showed a mean of 19.94 bacteria per cell and a non-typable throat isolate showed a mean of 37.72 bacteria per cell. These isolates readily hemagglutinated human red blood cells. None of the other 12 type b blood or spinal fluid isolates tested adhered well (range 0.04-1.34 bacteria per cell) nor hemagglutinated red cells. There was no difference in the adherence of H. influenzae to buccal mucosal cells from 6 donors, and no difference between epithelial cells obtained from the buccal or nasal mucosa. Although both type b and non-typable H. influenzae strains appear capable of adhering to human epithelial cells, many strains do not. The role of adherence factors in the maintenance of mucosal colonization with these poorly-adherent strains remains unknown.

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“…The animals were sacrificed 6 days after the initial inoculation. At this time, nasal cultures were obtained by allowing the animals to inhale a drop of sterile phosphate-buffered saline which subsequently was aspirated from the nares and plated onto agar containing HiTb antiserum (6). Five to ten nasopharyngeal colonies were selected from several infant rats for in vitro adherence studies.…”

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confidence: 99%

Role of adherence in the pathogenesis of Haemophilus influenzae type b infection in infant rats

Kaplan

Mason

Wiedermann³

1983

Infect Immun

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We evaluated the role of pili in the pathogenesis of disease due to Haemophilus influenzae type b (HiTb), using the infant rat model. Piliated and nonpiliated HiTb strains were isolated from the nasopharynx and cerebrospinal fluid, respectively, of three children. Infant rats inoculated intranasally with nonadherent HiTb developed bacteremia and meningitis more frequently (P = 0.005) than animals inoculated with companion adherent HiTb strains. When analyzed separately, only one HiTb pair (884/880) demonstrated significant differences in the incidence of bacteremia and meningitis between the adherent and nonadherent strains. Blood or cerebrospinal isolates recovered from infant rats inoculated with piliated adherent HiTb strains were not piliated and were not adherent in vitro. Adherent and nonadherent HiTb colonized the nasopharynx of infant rats equally. The piliated strains of HiTb were not adherent in vivo or in vitro to rat nasal or buccal epithelial cells, respectively. Piliated strains of HiTb have no apparent advantage over nonpiliated HiTb strains for colonization or invasion of infant rats. Furthermore, the loss of piliation is noted for cerebrospinal fluid, blood, and nasal isolates of HiTb cultured from infant rats inoculated with an adherent piliated HiTb strain. Thus, the loss or suppression of pili may be an important prerequisite for the invasion of the host by HiTb strains that are highly piliated.

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Intralitter Transmission of Haemophilus influenzae Type b in Infant Rats and Rifampin Eradication of Nasopharyngeal Colonization

Cited by 19 publications

References 14 publications

Mechanisms of Bacterial Colonization of the Respiratory Tract

Mechanisms of Bacterial Colonization of the Respiratory Tract

Adherence of Haemophilus influenzae to Human Epithelial Cells

Role of adherence in the pathogenesis of Haemophilus influenzae type b infection in infant rats

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