Haemophilus influenzae Type D meningitis

Nasopharyngeal and Adenoid Colonization by Haemophilus influenzae and Haemophilus parainfluenzae in Children Undergoing Adenoidectomy and the Ability of Bacterial Isolates to Biofilm Production

Haemophili are pathogenic or opportunistic bacteria often colonizing the upper respiratory tract mucosa. The prevalence of Haemophilus influenzae (with serotypes distribution), and H. parainfluenzae in the nasopharynx and/or the adenoid core in children with recurrent pharyngotonsillitis undergoing adenoidectomy was assessed. Haemophili isolates were investigated for their ability to biofilm production.Nasopharyngeal swabs and the adenoid core were collected from 164 children who underwent adenoidectomy (2-5 years old). Bacteria were identified by the standard methods. Serotyping of H. influenzae was performed using polyclonal and monoclonal antisera. Biofilm formation was detected spectrophotometrically using 96-well microplates and 0.1% crystal violet.Ninety seven percent (159/164) children who underwent adenoidectomy were colonized by Haemophilus spp. The adenoid core was colonized in 99.4% (158/159) children, whereas the nasopharynx in 47.2% (75/159) children (P < 0.0001). In 32% (51/159) children only encapsulated (typeable) isolates of H. influenzae were identified, in 22.6% (36/159) children only (nonencapsulated) H. influenzae NTHi (nonencapsulated) isolates were present, whereas 7.5% (12/159) children were colonized by both types. 14.5% (23/159) children were colonized by untypeable (rough) H. influenzae. In 22% (35/159) children H. influenzae serotype d was isolated. Totally, 192 isolates of H. influenzae, 96 isolates of H. parainfluenzae and 14 isolates of other Haemophilus spp. were selected. In 20.1% (32/159) children 2 or 3 phenotypically different isolates of the same species (H. influenzae or H. parainfluenzae) or serotypes (H. influenzae) were identified in 1 child. 67.2% (129/192) isolates of H. influenzae, 56.3% (54/96) isolates of H. parainfluenzae and 85.7% (12/14) isolates of other Haemophilus spp. were positive for biofilm production. Statistically significant differences (P = 0.0029) among H. parainfluenzae biofilm producers and nonproducers in the adenoid core and the nasopharynx were detected.H. influenzae and H. parainfluenzae carriage rate was comparatively higher in the adenoid core than that in the nasopharynx in children undergoing adenoidectomy, suggesting that their involvement in chronic adenoiditis. The growth in the biofilm seems to be an important feature of haemophili colonizing the upper respiratory tract responsible for their persistence.

Maternal and neonatal sepsis caused by Haemophilus influenzae type d

A 29-year-old pregnant woman was admitted to hospital with signs of sepsis and threatened pre-term labour. The premature neonate also showed signs of sepsis. Haemophilus influenzae biotype III was cultured from a midstream urine sample taken from the mother, maternal placental swabs and neonatal blood cultures. The placental and neonatal isolates were both found to be serotype d by PCR, and were indistinguishable by PFGE.

A cluster of early neonatal sepsis and pneumonia caused by nontypable Haemophilus influenzae

Nine premature infants developed early onset sepsis and/or pneumonia with Haemophilus influenzae during a period of 53 months (January 2000 -May 2004). Their respiratory problems were pneumonia-like rather than classic respiratory distress syndrome. In 8 of the cases, the pathogen was a beta-lactamase-negative, nontypable H. influenzae. In the remaining case, the Haemophilus identified was type d. Before January 2000, no case of beta-lactamase-negative, nontypable H. influenzae sepsis or pneumonia had been recorded.

Haemophilus influenzae type D infection and IgG2 deficiency in a patient with chronic mucocutaneous candidiasis

A 14 year old boy with chronic mucocutaneous candidiasis and persistent pulmonary infection caused by Haemophilus influenzae and Streptococcus pneumoniae is reported. Initial bacterial culture studies showed H. influenzae type B and S. pneumoniae as causative agents. H. influenzae type D was constantly isolated from the patient's sputum. Abnormally low levels of serum immunoglobulin G2 (IgG2) found in the patient may have contributed to the pulmonary infection and H. influenzae type D may be an important causative agent in immunodeficient patients.

Posttraumatic meningitis due to Hemophilus influenzae type A

Posttraumatic meningitis is uncommon in children. This case report describes a 4-year-old child with this complication caused by an unusual type of Hemophilus influenzae. The efficacy of routine use of antibiotics in preventing posttraumatic meningitis remains uncertain. However, this report suggests that in the presence of prolonged fever and clinical evidence of a dural tear, antibiotic treatment is warranted.

Lethal meningoencephalitis and septicemia caused by Haemophilus influenzae type f in an adult with multiple myeloma

A patient with chemotherapy-treated multiple myeloma developed overwhelming sepsis and meningoencephalitis with Haemophilus influenzae type f. Typable H. influenzae other than type b has only rarely been reported as a cause of serious disease in adults. The patient's immunosuppressed status presumably predisposed her to this unusual infection.

Neonatal meningitis caused by Haemophilus influenzae type c

Haemophilus influenzae type c was isolated from blood and cerebrospinal fluid in a 3-day-old fullterm boy with clinical signs of serious infection. Ampicillin, cloxacillin and gentamicin were instituted initially. After 3 days of therapy the child developed a hemiparesis. Treatment was changed to chloramphenicol and the baby improved. The implications of H. influenzae serotype c as a possible pathogen, early diagnostic procedures and therapeutic problems are discussed.

Comparative virulence of Haemophilus influenzae with a type b or type d capsule

To determine the importance of specific capsule type in the pathogenesis of invasive Haemophilus influenzae disease, we compared the virulence of type b and type d strains isolated from different children with the virulence of transformation-derived type b and type d organisms. In addition, the unencapsulated derivative of these strains was also examined. Virulence was assessed by determining the ability of the strains to produce bacteremia with intranasal or subcutaneous inoculation. Unencapsulated derivatives were unable to cause bacteremia by any route; all type b strains (whether natural or derived by transformation), a natural type d, and a type d derived by transformation were able to produce bacteremia with similar frequency (42 to 62%) when 10(7) colony-forming units was given intranasally. Subcutaneous inoculation of 10(3) colony-forming units of strains with the type b capsule produced bacteremia at a greater frequency than did the strains with the type d capsule (P less than 0.002). The type d isolate was more virulent than a mutagenized derivative of the strain. We conclude that the type b strains are more virulent than type d when inoculated subcutaneously.

Non-type b Haemophilus influenzae infections in adults with reference to biotype

We report three cases of serious non-group b Haemophilus influenzae infections. The significance of these isolates with respect to both biotypes and serotypes is discussed.