Biliary tract infection caused by Haemophilus parainfluenzae.

Haemophilus parainfluenzae was isolated from the bile specimens of 2 patients with acute cholecystitis. The strains were genetically unrelated by the random amplified polymorphic DNA (RAPD). The 2 H. parainfluenzae strains represented 11.7% of all positive bile cultures inoculated in blood culture bottles. The routine inoculation of bile specimens in media able to support growth of Haemophilus species should be considered.     

R-factor involvement in a local outbreak of ampicillin-resistant Haemophilus influenzae infections.

In a Swedish nursery 11 of 15 children harboured non-encapsulated Haemophilus influenzae in their nasopharynx. Six children had ampicillin-resistant and beta-lactamase-producing isolates. Five of these children had otitis whereas one was healthy. In order to identify the origin of the H. influenzae isolates their O-antigen determinants were studied by an immunodiffusion technique. 18 different rabbit antisera were used. For each isolate an O-antigen pattern was recorded. Five of the 6 resistant isolates had the same O-antigen pattern, indicating that their origin was one strain. The 6th isolate was from another strain. Different isolates from the same strain were found to be either sensitive or resistant to ampicillin. In one child the H. influenzae lost its resistance during trimethoprim-sulphamethoxazole treatment. It is concluded that an R-factor may have been involved in the distribution of ampicillin resistance in the H. influenzae studied. Previous in-vitro studies have shown that beta-lactamase production can be transmitted by a plasmid among H. influenzae strains.     

Treatment failure in Haemophilus influenzae due to a beta-lactamase low-level ampicillin-resistant organism

Haemophilus influenzae is a rare causative organism of vertebral osteomyelitis in an adult. Cases reported in the literature were mainly caused by ampicillin-susceptible type b strains. Here we describe the first case of vertebral osteomyelitis due to a non-typeable, beta-lactamase low-level ampicillin-resistant H. influenzae strain with failure of prolonged intravenous amoxicillin treatment.     

A nosocomial outbreak of ampicillin-resistant Haemophilus influenzae type b in a geriatric unit

A nosocomial outbreak of Haemophilus influenzae type b (Hib) bronchitis occurred in a geriatric unit. The three infected patients were grouped together in an isolation unit and treated. A prevalence survey was done by obtaining pharyngeal cultures from patients and staff in the unit. One patient and a nurse were asymptomatic pharyngeal carriers of Hib. One infected patient was bedridden, and his only known Hib contact was the nurse. Geographic clustering was the only significant risk factor, as determined by a case-control study. Carriers were treated with rifampin. The isolates were characterized for strain relatedness by using three methods. All produced beta-lactamase and all were serotype b. Plasmid profiles and restriction endonuclease analysis of bacterial DNA were performed; chromosomes were digested with the restriction endonucleases HindIII and HaeIII. Strains were confirmed as identical by using these methods and were different from two Hib control strains producing beta-lactamase. This study documents nosocomial transmission of Hib, by using molecular typing methods.     

Haemophilus influenzae type e meningitis and bacteremia in a healthy adult

Haemophilus influenzae type b causes more than 95% of serious H. influenzae meningitis. H. influenzae type e (Hie) has been implicated in a few cases of meningitis. Here, we present an adult Saudi patient with Hie meningitis and review the literature. The patient, a 19-year-old Saudi male with no significant past medical history, was noted by his family to have some changes in his mentation, confusion and refusal to eat; subsequently, he became unresponsive. Cerebrospinal fluid and blood culture grew Hie. The patient was treated with intravenous ceftriaxone with full recovery.     

Serious systemic infection caused by non-encapsulated Haemophilus influenzae biotype III in an adult

Haemophilus influenzae is the aetiological agent in less than 1% of septic arthritis cases in adults and most often serotype b is involved. We report here a case of severe systemic infection due to non-encapsulated H. influenzae biotype III in a 40-year-old man, previously healthy although alcohol abuser. Cholangitis and acute alcoholic hepatitis were diagnosed simultaneously. The organism was grown from blood and from synovial fluid of the left knee, but several other joints were also affected. The close relationship between H. influenzae biotype III and H. aegyptius is mentioned in view of recent reports of fatal childhood illness caused by a special clone of H. aegyptius and the importance of reporting both serotype and biotype in severe H. influenzae induced disease is emphasized.     

Respiratory infections caused by non-typeable Haemophilus influenzae

PURPOSE OF REVIEW: This review will consider recent developments in the clinical aspects of infections due to non-typeable Haemophilus influenzae. In addition, newer developments in the areas of mechanisms of pathogenesis, host pathogen interaction, immune responses and efforts toward vaccine development will be reviewed briefly. RECENT FINDINGS: Non-typeable H. influenzae continues to be a common cause of otitis media in infants and children, sinusitis in children and adults, pneumonia in adults, and lower respiratory tract infection in adults with chronic obstructive pulmonary disease. While the rate of beta-lactamase production by isolates of H. influenzae varies geographically, most regions show a rate of 20-35% of isolates producing beta-lactamase. Recent studies have highlighted the possible role of bacterial biofilms formed by H. influenzae as a cause of otitis media. Several lines of evidence indicate that H. influenzae causes intracellular infection in the lower respiratory tract in chronic obstructive pulmonary disease and this observation has important implications in understanding the human immune response to the bacterium. Lipooligosaccharide is an important virulence factor for H. influenzae and research is generating new information on the complex role of this molecule in colonization and infection of the respiratory tract. Several surface molecules are under active evaluation as vaccine antigens. SUMMARY: Non-typeable H. influenzae is an important cause of respiratory tract infections in children and adults. Most strains are susceptible to amoxicillin/clavulanate, fluoroquinolones and the newer macrolides. Research in the next decade promises substantial progress in the challenge of developing vaccines for nontypeable H. influenzae.     

Lobar pneumonia caused by Haemophilus influenzae type B

Haemophilus influenzae type b is a rare cause of adult lobar pneumonia and we are unaware of any reported British cases. However in the United States this condition is well described and the incidence is increasing (Levin et al. 1977).     

Purulent pericarditis caused by Haemophilus influenzae type B

Purulent pericarditis, once a common entity associated with intrathoracic infections, such as pneumonia and empyema, has become an infrequent illness in the post-antibiotic era. Prompt recognition and therapy are vital in improving disease-related mortality. Herein, we describe a rare case of Haemophilus influenzae type B purulent pericarditis and associated cardiac tamponade. Antibiotic therapy, pericardial drainage, and subsequent pericardiectomy were performed with resolution of illness.     

Genetic analyses of beta-lactamase negative ampicillin-resistant strains of Haemophilus influenzae isolated in Okinawa, Japan

Recently, the instance of beta-lactamase-negative ampicillin (AMP)-resistant (BLNAR) strains of Haemophilus influenzae has exhibited a marked increase in Japan. Our group determined the MICs of 160 clinical isolates of H. influenzae at a university hospital in Okinawa, the southernmost part of Japan, and found that 27 strains were BLNAR, while 24 strains were beta-lactamase-producing. Among the latter, 2 strains were resistant to AMP/clavulanic acid. BLNAR strains were shown to be more resistant to cephems than non-BLNAR strains. The competitive affinity assay using biotinylated AMP for penicillin-binding protein (PBP) showed that the binding of cefotiam to PBP 3A/3B of BLNAR strain C2163 was lower than that of the AMP-susceptible strain, while bindings to other PBPs were not changed. The sequences of ftsI, the gene encoding transpeptidase domain of PBP 3A and/or PBP 3B, were determined, and it was found that sequences of the ftsI gene of BLNAR strains were heterogeneous mutations. Deduced amino acid sequence analyses of BLNAR strains showed that three residues (Asn-526, Val-547, and Asn-569) were replaced with Lys, Ile, and Ser, respectively. In addition, some BLNAR strains had an additional three residues (Met-377, Ser-385, and Leu-389) in ftsI replaced with Ile, Thr, and Phe, respectively. Furthermore, changes from Asp-350 to Asn-350 and from Ser-357 to Asn-357 were also found in most BLNAR strains. These substitutions were located around the penicillin binding sites of PBP3. Multiple substitutions in the amino acid sequence seemed to be closely related with extended resistance against beta-lactams, including third-generation cephems. Randomly amplified polymorphism DNA fingerprinting of clinical isolates of BLNAR strains showed genetic heterogeneity of the strains, suggesting that the prevalence of BLNAR in this region was a result of the emergence of multiple clones of this phenotype.     

Haemophilus influenzae bacteremia and meningitis resulting from survival of a single organism

Infant rats were infected intranasally with mixtures of streptomycin-sensitive and streptomycin-resistant strains of Haemophilus influenzae type b and cultures of nasopharyngeal washings, blood, and cerebrospinal fluid were obtained. If the infecting organisms cooperated with each other during the establishment of infection, nasopharyngeal, blood, and cerebrospinal fluid cultures should have contained mixtures of the variants. If each organism acted independently, then with small infecting inocula all the organisms in nasopharynx, blood, or cerebrospinal fluid should be descended from a single bacterium. Cultures should then contain only one of the variants.Single variant nasopharyngeal cultures were obtained from 8 out of 19 (42%) rats when the intranasal inoculum was <100 organisms. As the inoculum was increased, single variant cultures were less frequently observed. When the inoculum was >/=10(5) organisms, nasopharyngeal cultures were always mixtures. Single variant blood cultures were obtained in 46 of 67 (68.7%) episodes of bacteremia when rats were inoculated intranasally with 10(8) organisms. Single variants were isolated from the cerebrospinal fluid of 13 of 19 (68.4%) rats with meningitis whose blood contained both streptomycin-sensitive and streptomycin-resistant variants. When the blood contained a single variant, this same variant was cultured from the cerebrospinal fluid on 39 of 40 (97.5%) occasions. These studies demonstrated that invasive. H. influenzae b infections of infant rats resulted from independent action, as opposed to cooperative interaction of intransally inoculated organisms. The results also suggested that the meninges were invaded by the hematogenous route.     

Epidemiology of rob beta-lactamase among ampicillin-resistant Haemophilus influenzae isolates in the United States

We surveyed 161 clinical isolates of ampicillin-resistant, beta-lactamase-producing isolates of Haemophilus influenzae obtained between 1975 and 1985 to determine whether they produced TEM-1 or Rob beta-lactamase. Plasmid DNA was obtained from a Rob-producing isolate, F990, and a plasmid (pBR322) known to encode TEM-1. Both plasmids were labeled with 32P and hybridized to whole cell DNA obtained from the clinical isolates. All 161 isolates hybridized with one of the plasmid probes and could be classified as TEM-1- or Rob-producing isolates. Analysis of the distinctive pH profiles of the two beta-lactamases was used to confirm the findings of the DNA hybridization assay. Overall, 13 (8%) isolates obtained from patients in California, North Carolina, Tennessee, Missouri, Louisiana, and Mississippi produced the Rob beta-lactamase. The remaining isolates elaborated the TEM-1 enzyme. We conclude that ampicillin resistance in H. influenzae may be mediated by the production of Rob beta-lactamase and that the occurrence of this enzyme is not limited to the two isolates described to date.