A taxonomic study of the genus Haemophilus, with the proposal of a new species

Outer membrane protein and biotype analysis of non-serotypable strains of Haemophilus influenzae

Strains of Haemophilus influenzae (n = 161) were isolated from inpatients with symptoms of pulmonary infection. Conventional tests showed that 144 strains were non-serotypable and all belonged to one of eight biotypes. The common biotypes were 2 (41%), 3 (27.1%), 1 (13.2%) and 5 (10.4%). The outer membrane protein (OMP) profiles of 59 non-serotypable strains were examined by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). A comparison of OMP profiles suggested a possible association between several strains belonging to biotype 2. Although no clear correlation was established between biotype or OMP profile cluster groups and the age or clinical state of the patients from whom the strains were isolated, SDS-PAGE analysis was a useful technique for the epidemiological study of non-serotypable H influenzae.

Chancroid and Haemophilus ducreyi

Haemophilus ducreyi is the causative agent of chancroid, one of the genital ulcerative diseases. H. ducreyi is the major cause of genital ulcer disease in Africa and Southeast Asia and is of increasing concern in the United States. Definitive diagnosis of chancroid requires the isolation and identification of H. ducreyi, but isolation of this organism is difficult and the available medium is not optimal for all strains. Fluorescent antibody and serologic tests are of limited value. In general, our knowledge of this organism is rather limited, and indeed, recent studies have questioned the placement of H. ducreyi in the genus Haemophilus. H. ducreyi has relatively few biochemical activities, and epidemiologic studies are limited because there are limited phenotypic markers available for strain typing. Specific virulence factors of H. ducreyi have yet to be identified. Antimicrobial resistance in H. ducreyi is of special concern, as this organism has acquired both gram-negative and gram-positive resistance determinants. In addition, some of these determinants can be mobilized and transferred to other Haemophilus species or to Neisseria gonorrhoeae.

Subtyping of Haemophilus influenzae type b strains from Europe and North America by SDS-PAGE of whole-cell polypeptides: the geographical distribution of subtypes

One hundred and nine strains of Haemophilus influenzae type b were subtyped by sodium dodecyl sulphate polyacrylamide gel electrophoresis of whole-cell polypeptides. Twenty-one strains from England, 44 from Scotland, 8 from Sweden, 6 from the Netherlands and 30 from the USA were examined. Some of these strains had been subtyped by outer membrane protein analysis; most of the strains had been isolated from cases of invasive disease. Comparison of polypeptide profiles using the Dice coefficient of similarity showed that the majority of European strains were closely related and formed a single large group. Four smaller groups were identified; three of these included American and European strains, indicating a world-wide distribution of subtypes. However, the common European and American subtypes fell into different groups, indicating the existence of marked geographical variations in subtype frequency.

Treating chancroid: summary of studies in southern Africa

Recent studies undertaken in southern Africa and elsewhere indicate that many short or single dose treatments are available to treat chancroid. Erythromycin 500 mg three times a day for five days, ciprofloxacin 500 mg, sulphamethopyrazine 800 mg and trimethoprim 1000 mg or sulphametrole 3200 mg and trimethoprim 640 mg as single oral doses, or ceftriaxone 250 mg as a single intramuscular injection are all effective in treating the disease. The widespread use of these regimens largely depends on the accuracy of diagnosis, susceptibilities of local Haemophilus ducreyi isolates to antimicrobials, and financial considerations.

Characterisation and antimicrobial sensitivity of haemophili isolated from pigs

A total of 70 haemophili from Australia pigs was compared with a range of reference strains of porcine haemophili. Forty-eight of the isolates were identified as Actinobacillus pleuropneumoniae biovar 1 and the remaining 22 isolates as Haemophilus parasuis. Forty one of the A. pleuropneumoniae isolates were used in a study to determine to the minimal inhibitory concentration (MIC) of 12 antimicrobial agents, or combinations of agents. Penicillin, neomycin, trimethoprim, trimethoprim-sulphamethoxazole and tetracycline all showed low MIC values, indicating their potential for the treatment of porcine pleuropneumonia, although 2 isolates showed resistance to tetracycline. A wide range of MIC values was encountered with the sulphonamides.

Phosphatase activity is a constant feature of all isolates of all major species of the family Enterobacteriaceae

In this study we evaluated phosphatase activity in members of the family Enterobacteriaceae by conventional methods and by a novel method. The novel method is based on the formation of bright-green-strained colonies by phosphatase-positive, but not phosphatase-negative, strains in the presence of a phosphate substrate, such as phenolphthalein monophosphate or 6-benzoylnaphthyl phosphate (6-BNP), and methyl green. A total of 1,055 strains belonging to 65 different species of Enterobacteriaceae were tested for green staining of the colonies in the presence of methyl green and either phenolphthalein monophosphate or 6-BNP and for phosphatase activity by three different conventional methods. With the sole exception of one Leminorella richardii type strain, all isolates of all of the species formed green-stained colonies in the presence of the substrate 6-BNP. All strains were phosphatase positive by all of the conventional methods.

Evolutionary genetics of the encapsulated strains of Haemophilus influenzae

Genetic relationships among 2209 isolates of Haemophilus influenzae of polysaccharide capsule serotypes a, b, c, d, e, and f were determined by analyzing electrophoretically demonstrable allelic variation at 17 chromosomal enzyme loci. We distinguished 280 electrophoretic types (ETs), representing distinctive multilocus genotypes. Genetic diversity among ETs of isolates of the same serotype was, on average, only 67% of that in the total sample, and no ETs were shared among isolates of different serotypes. Cluster analysis of the ETs revealed 2 primary phylogenetic divisions at a genetic distance of 0.66 and 12 major lineages diverging from one another at distances greater than 0.42. In general, strains of different phylogenetic lines or groups of allied lineages have characteristic cap region restriction fragment length polymorphism patterns obtained by digestion of genomic DNA with EcoRI. Strains producing serotype c, e, and f capsules have no close relationships to those of other encapsulated strains. Lineages of both serotype a and b strains occur in each primary phylogenetic division, most probably as a result of the transfer of serotype-specific sequences of the cap region between clonal lineages. Serotype a strains allied in division I with a group of abundant serotype b clones and the serotype d strains apparently are more virulent than the serotype a strains in division II, which are related to serotype b and f strains that rarely cause invasive disease.

Lectin typing of Haemophilus ducreyi

The cell wall carbohydrates of 43 strains of Haemophilus ducreyi isolated in different parts of the world were subjected to lectin analysis using commercial panels containing 14 different plant lectins of known specificity. Preliminary evidence indicated both intrastrain and inter-strain variation in cell wall carbohydrate composition. In addition, it was possible to group strains from different geographical areas by lectin agglutination patterns. Lectin typing might thus become a useful marker system for epidemiological investigation of Haemophilus ducreyi infections.

Antimicrobial susceptibilities of southern African isolates of Haemophilus ducreyi

We determined the antimicrobial susceptibilities of 122 recent clinical isolates of Haemophilus ducreyi to 24 antimicrobial agents. All isolates produced beta-lactamase and were resistant to penicillins. The majority of strains were also resistant to tetracycline, doxycycline, and sulfamethoxazole. All isolates were susceptible to macrolides, quinolones, extended-spectrum cephalosporins, spectinomycin, rifampin, and amoxycillin-clavulanate. Reduced susceptibility to minocycline, co-trimoxazole, and kanamycin was noted. Chloramphenicol and thiamphenicol resistance was noted for the first time among southern African strains.

rRNA gene restriction patterns of Haemophilus influenzae biogroup aegyptius strains associated with Brazilian purpuric fever

The rRNA gene restriction patterns of 92 isolates of Haemophilus influenzae biogroup aegyptius, associated with conjunctivitis or Brazilian purpuric fever in the State of São Paulo, Brazil, were studied with 16 + 23S rRNA from Escherichia coli as a probe. All strains were classified into 15 patterns. Isolates from Brazilian purpuric fever cases were seen only in patterns 3 (most frequently) and 4 (rarely), whereas isolates from conjunctivitis were found in all 15 patterns. The study demonstrated that rRNA from E. coli can serve as a probe for molecular epidemiology.

Biotyping respiratory Haemophilus species with the microbact system

The biochemical characteristics of 114 respiratory Haemophilus isolates were examined by the Minitek and Microbact systems. The Microbact system was easy to use and read, although some of the less important reactions (glucose and xylose) were difficult to interpret on occasions. On the basis of the 3 crucial reactions--indole production, ornithine decarboxylase and urease activity--discrepancies between the two systems were minor. Given careful standardization of techniques the Microbact system is a suitable alternative to established techniques for the biotyping of H. influenzae and H. parainfluenzae.

Treating chancroid with enoxacin

Increasing resistance of Haemophilus ducreyi to antimicrobials necessitates further trials of new antimicrobial agents for treating chancroid. Enoxacin has excellent in vitro activity against H ducreyi, and a randomised clinical trial of three doses of enoxacin 400 mg at intervals of 12 hours compared with a single dose of trimethoprim/sulphametrole (TMP/SMT) 640/3200 mg was therefore conducted. Of 169 men enrolled in the study, 86 received enoxacin and 83 received TMP/SMT. Ulcers were improved or cured in 65/73 men treated with enoxacin and 57/70 men treated with TMP/SMT. This difference was not significant. At 72 hours after treatment, H ducreyi was eradicated from ulcers of 72/77 men treated with enoxacin and of 67/74 of those treated with TMP/SMT. Patients with buboes responded equally well to both treatments. Of 100 H ducreyi strains tested, all were susceptible to both 0.25 mg/l enoxacin and the combination of 0.25 mg/l TMP and 5 mg/l SMT. Although most men treated with either regimen were cured, neither regimen appeared to be the optimum treatment for chancroid. This study shows the efficacy of enoxacin for a soft tissue infection caused by Gram negative organisms.

Characterization of Haemophilus influenzae isolated from patients with otitis media

Two hundred and twenty-three Haemophilus influenzae strains isolated from patients with otitis media throughout France were characterized by biotype, serotype, antibiotic susceptibility, type of beta-lactamase production and human erythrocyte agglutination properties. All strains fell in one of two groups. One group consisted of encapsulated type b strains, 50% of which were biotype I, often resistant to ampicillin (38.5% of beta-lactamase producing strains) and seldom positive for haemagglutination (3.8%). The second group was composed of non-encapsulated strains, 42% of which were of biotype II, 10.6% beta-lactamase producers and 10.5% positive for haemagglutination.

Comparison of antibiotic resistant and sensitive strains of Haemophilus influenzae type b in The Netherlands by outer-membrane protein subtyping

The percentage of beta-lactamase producing Haemophilus influenzae strains from patients with meningitis in The Netherlands increased from 0% in 1975/1976 to 4.6% in 1985/1986 (n = 1559). Twenty-three isolates resistant to ampicillin, penicillin, chloramphenicol, rifampicin and/or tetracycline were subtyped to determine if one resistant strain was spreading. (Sub)typing was performed by capsular typing, analysis of the major outer membrane protein patterns on sodium dodecylsulfate gels (SDS-PAGE subtypes), lipopolysaccharide serotyping and biotyping. The (sub)types of the resistant strains were similar to those of sensitive strains, thus indicating that antibiotic resistant strains develop at random.

Limited diversity of the immunoglobulin A1 protease gene (iga) among Haemophilus influenzae serotype b strains

Immunoglobulin A1 (IgA1) proteases are thought to be important virulence factors in certain bacterial infections, including meningitis, and may have potential usage in vaccines. In this study, we compared the locations of EcoRI, BamHI, and PstI restriction endonuclease sites in the IgA1 protease gene (iga) region of whole-cell DNA from 76 Haemophilus influenzae strains. The analysis was performed by using isolated fragments of the cloned iga gene, which encodes the IgA1 protease originating from a H. influenzae serotype d strain, as probes in Southern blot experiments. All strains, including three without detectable IgA1 protease activity, had DNA sequences with a high degree of homology to the iga probes. The numbers and sizes of the DNA fragments hybridizing with the probes indicated that only three strains, none of which was of serotype b, had more than one iga gene. The iga restriction fragment length patterns of 60 clinical isolates of serotype b were of only four distinct types, which correlated with previously observed clusters of multilocus genotypes (electrophoretic types). This correlation supports the concept of the clonal population structure of H. influenzae. Three of the iga gene restriction types, which appear to represent 98% of the H. influenzae serotype b population, encode IgA1 proteases that were inhibited by antisera to any one of these types and therefore could form the basis for the development of a vaccine against H. influenzae meningitis.

Nasopharyngeal carriage and antibiotic resistance of Haemophilus influenzae in healthy children

An investigation was undertaken to determine the isolation rate and antibiotic resistance of Haemophilus influenzae from the nasopharynx of young children. The 996 subjects studied were up to 6 years of age. H. influenzae was isolated from 304 (30.5%) and strains of capsular type b from 11 (1.1%). Age, sibling status, season, respiratory infection and antibiotic therapy all influenced isolation rates. The overall prevalence of antibiotic resistance in the strains isolated was ampicillin 5.4% (all beta-lactamase producers), cefaclor 0.3%, chloramphenicol 1.3%, erythromycin 38.2%, tetracycline 1.3%, trimethoprim 5.4% and sulphamethoxazole 0%. Ampicillin resistance was more common in type b than non-capsulated strains.

Early synergistic killing activity at concentrations attainable in CSF of amoxicillin or cefotaxime and aminoglycosides against Haemophilus influenzae

Rapid eradication of bacteria from the CSF is critical for the outcome of Haemophilus influenzae meningitis in children. In 15 patients studied, the mean H. influenzae colony counts in CSF were 10(5) CFU/ml (range: 10(2) to 10(9) CFU/ml). Time-kill curves were determined for amoxicillin and cefotaxime alone and in combination with gentamicin or amikacin, against 60 clinical isolates of H. influenzae at concentrations equivalent to those found in CSF following systemic administration. Against beta-lactamase-negative strains (n = 44) a bactericidal effect was observed at 18 h for amoxicillin alone, at 5 h for amoxicillin plus aminoglycosides and at 2.5 h for cefotaxime with or without aminoglycosides. Against beta-lactamase-positive strains a bactericidal effect was observed at 18 h for cefotaxime, at 5 h for amoxicillin plus aminoglycosides and at 2.5 h for cefotaxime plus aminoglycosides. It appears that despite low concentrations of gentamicin or amikacin in the CSF, the accelerated killing of H. influenzae provides a rationale for the initial use of the combination of cefotaxime and aminoglycosides in the initial treatment of H. influenzae meningitis.

National collaborative study of the prevalence of antimicrobial resistance among clinical isolates of Haemophilus influenzae

A total of 2,811 clinical isolates of Haemophilus influenzae were obtained during 1986 from 30 medical centers and one nationwide private independent laboratory in the United States. Among these, 757 (26.9%) were type b strains. The overall rate of beta-lactamase-mediated ampicillin resistance was 20.0%. Type b strains were approximately twice as likely as non-type b strains to produce beta-lactamase (31.7 versus 15.6%). The MICs of 12 antimicrobial agents were determined for all isolates. Ampicillin resistance among strains that lacked beta-lactamase activity was extremely uncommon (0.1%). Percentages of study isolates susceptible to cefamandole, cefaclor, cephalothin, and cephalexin were 98.7, 94.5, 87.3, and 43.3%, respectively. For 14 strains (0.5% of the total), chloramphenicol MICs were greater than or equal to 8.0 micrograms, and thus the strains were considered resistant. All of these resistant strains produced chloramphenicol acetyltransferase. In addition, all 14 strains were resistant to tetracycline; 11 produced beta-lactamase. The percentage of isolates susceptible to tetracycline was 97.7%. In contrast, erythromycin and sulfisoxazole were relatively inactive. The combination of erythromycin-sulfisoxazole (1/64) was more active than erythromycin alone but essentially equivalent in activity to sulfisoxazole alone. Finally, small numbers of clinical isolates of H. influenzae were resistant to trimethoprim-sulfamethoxazole and rifampin.

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans in human periodontal diseases

Bacteroides gingivalis, Bacteroides intermedius and Actinobacillus actinomycetemcomitans seem to be major pathogens in advancing periodontitis in man. First, these organisms are recovered in higher prevalence and proportions from progressive periodontitis lesions than from quiescent periodontal sites. Second, antibody levels against B. gingivalis and A. actinomycetemcomitans are markedly elevated in serum and gingival crevice fluid of periodontitis patients compared to normal controls. Third, B. gingivalis and B. intermedius elaborate potent proteases and A. actinomycetemcomitans various noxious substances which have the potential to perturb important host defenses and to disintegrate key constituents of the periodontal tissues. Monitoring these bacteria in advanced periodontal lesions may greatly assist the assessment of treatment efficacy and risk of further periodontal breakdown.

Haemophilus influenzae serotype a: outer membrane protein classification and correlation with DNA polymorphism at the cap locus

Fifty-four temporally and geographically distinct isolates of Haemophilus influenzae serotype a were characterized by (i) outer membrane protein composition and (ii) DNA polymorphism at the cap locus. In 53 of 54 cases, knowledge of the outer membrane protein type was accurately predictive of the cap locus polymorphism, suggesting that the majority of H. influenzae (type a) isolates have evolved from a limited number of clones.

Haemophilus segnis endocarditis

Haemophilus segnis is a rarely recognised commensal in the oropharynx. We wish to report the first published case of endocarditis caused by H. segnis. The patient, a 76-year-old female did not recover until after 2 courses of ampicillin given for a total of 57 days. In the second course of treatment, ampicillin was combined with 10 days of netilmicin therapy.

Urinary tract infection caused by Haemophilus influenzae. A case report

In a patient with frequent symptoms of urinary tract infection during the past 5 years and steadily deteriorating renal function, standard urine cultures were mostly negative. Following microscopy of freshly voided, gram-stained urine, culture on haematin agar plates incubated in 10% CO2 resulted in isolation of Haemophilus influenzae. Augmented culture procedures may identify the cause of symptoms in similar cases.

Nasopharyngeal bacteriology and secretory otitis media in young children

A prevalence study was performed on the nasopharyngeal bacteriology of 112 young children, aged 4-6 years. During the preceding 2 years, 74 of these children had suffered from secretory otitis media (SOM) and 40 had had normal middle ear ventilation. At the examination, one-third of the children with SOM had improved their middle ear status (previous SOM group), whereas otomicroscopy and tympanometry remained unchanged in the healthy group. The nasopharyngeal swab sample was obtained from behind the soft palate by the oral route. The isolation rate of Streptococcus pneumoniae was significantly higher in the SOM group than in the two other groups of children (p less than 0.006). The most commonly isolated capsular types of pneumococci were 6, 19, and 23, corresponding to the types involved in acute otitis media. The isolation rate of Haemophilus influenzae was 50% and an even distribution was found among the three groups of children examined. Biotypes I, II, III and IV accounted for 75% of the isolated cases of H. influenzae. As in acute otitis media, S. pneumoniae also seemed to play an important role in the pathogenesis of tubal dysfunction and SOM, and the difference is probably caused by variations in the quantitative colonization of pneumococci in the nasopharynx.

Comparison of amoxycillin/clavulanate with amoxycillin in children and adults with chronic obstructive pulmonary disease and infection with Haemophilus influenzae

71 children and adults (median age 7 years) with chronic obstructive pulmonary disease in which ampicillin-sensitive Haemophilus influenzae were isolated from lower airway secretions were included in a single-blind study comparing amoxycillin/clavulanate and amoxycillin alone. The dosage of amoxycillin was 50 mg/kg/day given together with probenecid and divided in 3 doses. Duration of treatment was 14 days. Clinical and bacteriological examinations were performed at study entry and again immediately after the treatment period. A late bacteriological follow-up 1.5 months after entry was performed. 65 patients were eligible for analysis of clinical outcome, and no difference between the groups was found. Side-effects were mild at a frequency of 3% for either preparation. In terms of eradication of the initially isolated H. influenzae amoxycillin/clavulanate tended to be better than amoxycillin, although the difference was not significant (70% and 57%, respectively). In a subset of 33 patients with polymicrobial flora amoxycillin/clavulanate was significantly more effective than amoxycillin. However, amoxycillin/clavulanate did not significantly reduce the emergency of beta-lactamase producing H. influenzae during treatment, and thus offers no advantage over amoxycillin in patients with amoxycillin-sensitive H. influenzae. The combination should be reserved to patients with either polymicrobial flora or ampicillin-resistant H. influenzae.

Neonatal infections with Haemophilus species

During a 27 month study seven nonserotypable strains of Haemophilus influenzae and two of Haemophilus parainfluenzae were isolated from nine neonates. Seven had early infection associated with respiratory distress or conjunctivitis; three had septicaemia one of whom died. The incidence of haemophilus septicaemia was 0.23 per 1000 live births.

Beta-lactamase production in the upper respiratory tract flora in relation to antibiotic consumption: a study in children attending day nurseries

The occurrence of beta-lactamase production in Haemophilus influenzae, Branhamella catarrhalis and Moraxella nonliquefaciens was compared in 191 healthy children attending day nurseries in 2 municipalities differing with regard to the prescription rate of beta-lactam antibiotics. A significantly higher frequency of beta-lactamase production was recorded in M. nonliquefaciens isolated in the municipality with the higher prescription rate. A corresponding difference was not recorded for H. influenzae or B. catarrhalis. Approximately 75% of the nasopharyngeal pathogens H. influenzae, B. catarrhalis and Streptococcus pneumoniae, as well as the commensal M. nonliquefaciens, were eliminated and often replaced by other strains of either species over a period of one month. Although none of the children were on antibiotics a substantial proportion of the acquired strains produced beta-lactamase. This suggested that the carrier rate of beta-lactamase producing strains of the respiratory tract is not only related to the effect of recent antibiotic treatment but also to the prevalence of such strains in the population.

Genomic relationships and species differentiation in the genus Capnocytophaga

Ten epidemiologically independent Capnocytophaga strains from clinical materials constituted three distinct DNA homology groups corresponding to the established species, Capnocytophaga ochracea, sputigena, and gingivalis. The three groups exhibited only low, or even insignificant degrees of genomic relatedness mutually, and to a reference culture of CDC group DF-2. All of five Capnocytophaga ochracea strains considered were involved in topic infections whereas four strains, isolated from blood belonged to either Capnocytophaga sputigena or Capnocytophaga gingivalis. However, Capnocytophaga ochracea and Capnocytophaga sputigena could not be discriminated on the basis of DNA base composition, genome size, or phenotypic features including cellular fatty acids, lipoquinones, and various fermentation and hydrolase reactions. The need for additional phenotypic criteria characterizing species of Capnocytophaga is underlined by the present findings.

Haemophilus influenzae type b strains of outer membrane subtypes 1 and 1c cause different types of invasive disease

Of 275 consecutive Haemophilus influenzae type b (Hib) strains isolated from children with invasive disease in Finland in 1985-86, 74% were of the common European outer membrane protein (OMP) subtype 1 and 22% were of OMP subtype 1c, which is usually rare. Strains of subtype 1c caused proportionately more meningitis and less epiglottis than did strains of subtype 1c. Furthermore, children with disease due to strains of subtype 1c were younger than those with disease due to strains of subtype 1. The significant difference in association between subtype and the diagnosis of epiglottitis or meningitis remained even when the strong influence of age was accounted for. This finding may suggest a true difference in the virulence between these subtypes not previously demonstrated for Haemophilus influenzae type b.

DNA probe technology for detection of Haemophilus influenzae

A 5 kb Haemophilus influenzae DNA fragment involved in penicillin-binding proteins expression was used as a probe for specific detection of H. influenzae strains. The 32p-labeled probe specificity was assessed by hybridization to bacterial dots and 75 strains were tested. All H. influenzae (18) and H. aegyptius (1) strains reacted very strongly with the probe. The H. influenzae serotypes tested (a, b, and non-typable strains) did not differ in their hybridization. Some hybridization was also found with the 12 other Haemophilus species tested as well as other Pasteurellaceae such as Actinobacillus lignieresii and Pasteurella multocida. Two other less related species (Klebsiella ozaenae and Providencia stuartii) also showed low hybridization. The probe detected as low as 10(5)-10(6) H. influenzae cells and 0.1 microgram of DNA in a dot sensitivity test. Hybridization to electroblotted, digested DNA from different species which reacted in the bacterial dot test revealed strong hybridization to H. influenzae and H. aegyptius only. This DNA probe should prove useful for H. influenzae and possibly H. aegyptius detection due to its high specificity and sensitivity under stringent hybridization conditions.

Determination of biotypes of Haemophilus influenzae and Haemophilus parainfluenzae a comparison of methods and a description of a new biotype (VIII) of H. parainfluenzae

A total of 180 strains of Haemophilus influenzae and 119 strains of Haemophilus parainfluenzae were characterized with respect to biotype (i.e., production of indole, urease, and ornithine decarboxylase) using conventional biochemical methods and two commercially available biotyping systems: Trio-Tube Haemophilus system (Carr Microbiologicals) and the Rapid NH System (Inovative Diagnostic Systems). Concordance between the results of the Trio-Tube system and conventional biochemicals was achieved with 294 of the 299 test organisms (98.3%). With the Rapid NH System, concordance with the results of conventional biochemical tests was observed with 275 of the 299 tests strains (92.0%). One previously unrecognized biotype of H. parainfluenzae, designated biotype VIII, is described. Typical reactions of this biotype include indole production but no production of urease or ornithine decarboxylase.

Haemophilus influenzae subtyping by SDS-PAGE of whole-cell polypeptides

Strains of Haemophilus influenzae isolated from patients in N.E. Scotland between 1983 and 1986 have been subtyped by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) of whole-cell polypeptides. Gels were stained with Coomassie blue and polypeptide profiles were analysed using the Dice coefficient of similarity. Type b strains were all closely related, the 19 strains analysed being grouped at a 90% similarity level into one large (13 strains) and one small (3 strains) cluster with 3 strains being ungrouped. Thirty-six non-typable, epidemiologically unrelated strains were subtyped; one pair of strains had indistinguishable polypeptide profiles. The polypeptide profiles of the remaining strains showed much heterogeneity, although groups of strains isolated from the same patient over short periods showed indistinguishable profiles.

Separation of Haemophilus influenzae type b subtypes by numerical analysis

Outer membrane proteins (OMPs) were prepared from 20 previously established subtypes of Haemophilus influenzae type b. Proteins were separated by one-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis (11% acrylamide). Each lane in the gels contained two internal molecular weight standards. One central lane contained a range of molecular weight standards, which were used to calculate a molecular weight curve for each gel. Migration distances of the OMPs were determined with a soft laser-scanning densitometer, and the distances were normalized by using the mean migration distances of the internal standards. The protein patterns of all subtypes were compared by a recently described method (B.D. Plikaytis, G.M. Carlone, and B.B. Plikaytis, J. Gen. Microbiol. 132:2653-2660, 1986). All subtypes could be differentiated by this method. The ability to store and compare numerous OMP patterns from different isolates of H. influenzae type b, separated with a single homogeneous polyacrylamide gel, will facilitate the continued development of a subtyping system based on these proteins.

Resistance of clinical isolates of Haemophilus influenzae in United Kingdom 1986

Between 1 January and 31 March 1986, 2434 strains of Haemophilus influenzae collected from 23 laboratories in the United Kingdom were examined. With the same criteria as previous studies in 1977 and 1981 the prevalence of resistance was: ampicillin 7.8% (6.2% beta-lactamase producers and 1.6% non-producers), tetracycline 2.7%, chloramphenicol 1.7%, trimethoprim 4.2%, and sulphamethoxazole 3.5%. of the 87 capsulated strains, 15 produced beta-lactamase, nine were resistant to ampicillin but did not produce beta-lactamase, and two strains, one of which produced beta-lactamase, were resistant to chloramphenicol and tetracycline. Since 1977 the prevalence of resistance to ampicillin, chloramphenicol, and trimethoprim has increased significantly. During 1981-6 strains resistant to ampicillin but not producing beta-lactamase and strains resistant to trimethoprim have significantly increased.

Types and subtypes of 73 strains of Haemophilus influenzae isolated from patients more than 6 years of age with meningitis in The Netherlands

Strains of Haemophilus influenzae isolated in The Netherlands between 1975 and 1984 from patients with meningitis were analysed in order to determine whether older patients are infected with particular types or subtypes of the organism. Of 1154 patients with H. influenzae meningitis 73 (6.3%) were more than 6 years of age. Thirty-one strains (42%) were of serotype b, one strain was of serotyped, one strain was of serotype f and 40 strains (55%) were non-typable. Twenty-eight type b strains were available for subtyping by analysis of the major outer-membrane proteins by sodium dodecylsulphate (SDS)-polyacrylamide gel electrophoresis (PAGE), by serotyping of their lipopolysaccharides and by biotyping. Twenty-one strains were outer-membrane protein subtype 1,24-lipopolysaccharide serotype 1 and 24 biotype I. Seventeen strains (61%) combined these characteristics. This percentage did not differ significantly from the percentage found for strains isolated from patients of all age groups (80%). The 32 non-typable H. influenzae strains analysed had different outer-membrane protein patterns as seen by SDS-PAGE. Five biotypes were found, among which biotype II was predominant (21/32). The results indicated that (i) patients more than 6 years of age were infected by subtypes of H. influenzae b strains which were not significantly different from the strains isolated from younger patients, (ii) non-typable strains of H. influenzae were much more common (55%) in the older age group than in the younger (1.2%) and (iii) that these non-typable strains were not of a particular subtype.

Supraglottitis and Hemophilus parainfluenzae: pathogenic potential of the organism

Hemophilus parainfluenzae may be a normal inhabitant of the pharynx, but it can have pathogenic potential elsewhere in the body. It has been identified as a cause of bacteremia and meningitis. The case discussed here represents the first report of H parainfluenzae-induced supraglottitis in a child. In reviewing its pathogenic potential in the upper respiratory tract, it appears that its major effect could be the ability to transfer ampicillin resistance to ampicillin-susceptible Hemophilus influenzae.

Isolation and molecular characterization of beta-lactamase-producing Haemophilus parainfluenzae from the genital tract

Three Haemophilus parainfluenzae strains isolated from the urogenital tract harbored a beta-lactamase-coding 3.2-megadalton plasmid identical, by restriction endonuclease digestion and hybridization with radioactive and biotin-labeled probes specific for the TEM-1 beta-lactamase and TnA sequences, to the 3.2-megadalton "African-type" plasmid found in Neisseria gonorrhoeae.

[Brazilian purpuric fever: preliminary results of the etiological research]

Em várias regiões do interior do Estado de São Paulo, notificou-se a partir do final de 1984 a 1986, a ocorrência de doença até então desconhecida, com características clínicas, em muitos aspectos, semelhante à meningococcemia. Esta síndrome foi denominada Febre Purpúrica Brasileira (FPB). Em quinze dos casos com quadro clínico compatível com a síndrome, o Haemophilus aegyptius foi isolado a partir de culturas de sangue, de líquido cefalorraquidiano sanguinolento, de secreção conjuntival e orofaríngea. Analisa-se a importância deste achado, face à existência de somente um relato na literatura, de infecção sistêmica por bactérias desta espécie.

Influence of growth medium and supplement on growth of Haemophilus influenzae and on antibacterial activity of several antibiotics

In the present study, five non-beta-lactamase- and five beta-lactamase-producing strains of Haemophilus influenzae were used to determine whether three different growth media, Mueller-Hinton broth and agar, brain heart infusion broth and agar, and tryptic soy broth and agar, and their added supplements (0.2% hemin-0.1% IsoVitaleX, 1% hemin-1% IsoVitaleX, 2% sheep blood, 10% Fildes enrichment, 5% Fildes enrichment, 1% supplement B, 5% horse erythrocytes, and 2% hemoglobin-1% IsoVitaleX) would influence the growth rate of this microorganism and the antibacterial activity of eight antibiotics, including ampicillin, tetracycline, chloramphenicol, gentamicin, cefamandole, erythromycin, trimethoprim-sulfamethoxazole (TMP-SMX), and cefoperazone. The growth curve studies were carried out with an initial inoculum of 10(4) bacteria per ml, and MICs were determined with an inoculum of 5 X 10(5) microorganisms. Mueller-Hinton broth, brain heart infusion broth, and tryptic soy broth enriched with 5% Fildes resulted in a maximal growth of more than 10(8) CFU/ml at 24 h. When 10% Fildes or 2% sheep blood was added as enrichment to Mueller-Hinton broth, a considerable reduction in the growth rate of H. influenzae strains resulted (P less than 0.01). Significant variations in MICs (P less than 0.01) were observed with chloramphenicol, TMP-SMX, erythromycin, and cefoperazone when brain heart infusion agar, Mueller-Hinton agar, or tryptic soy agar was used. Chloramphenicol, gentamicin, erythromycin, and TMP-SMX were all affected by the different enrichments added to Mueller-Hinton agar. MICs were in general higher with 5% Fildes enrichment and lower with 1% supplement B. Cefoperazone was the only drug which exhibited a lower MIC in 5% Fildes enrichment for ampicillin-resistant H. influenzae strains.

Enzyme profile of Haemophilus ducreyi strains isolated on different continents

Two hundred strains of Haemophilus ducreyi, isolated in different parts of the world, were investigated using the API-ZYM system, which included 95 different substrates. All strains produced aminopeptidase against beta-naphthylamide derivatives of L-lysine, glycine, L-arginine, L-alanine, D-L-methionine, glycyl-glycine, glycyl-L-alanine and L-leucine. All strains also produced alkaline and acid phosphatase and phosphohydrolase. Nearly all strains showed esterase activity against butyrate, valerate, caproate and caprylate, but the reactions were very weak. No glycosidase activity could be detected. Of the 47 aminopeptidase tests showing variable reactions, only the results for S-benzyl-L-cystine, L-ornithine, L-alanyl-L-phenyl-alanyl-L-proline, L-hystidyl-L-leucyl-L-histidine and L-histidyl-L-serine arylamidase obtained on strains from Asia, Africa and Europe were significantly different (p less than 0.05). On the basis of test results for L-ornithine arylamidase and L-alanyl-L-phenyl-alanyl-L-proline arylamidase, the distribution of three biovars found among the isolates of the different continents was significantly different (p less than 0.0001), whereas African strains isolated in Kenya and South Africa yielded the same enzymatic pattern. Thus, these enzymes may constitute a marker system for the epidemiological study of Haemophilus ducreyi.

Limited genetic diversity of Haemophilus influenzae (type b)

170 strains of Haemophilus influenzae (serotype b), isolated largely from patients with invasive disease from differing temporal and geographic origins were characterized using the combined approaches of DNA hybridization and outer membrane protein classification. Hybridization of a DNA probe to a region of the chromosome involved in the expression of type b capsular polysaccharide revealed that 163 (96%) isolates had one of three distinct, but closely related, chromosomal restriction fragment length polymorphisms (RFLPs). Each polymorphism was associated with its own distinctive set of outer membrane protein subtypes, indicating that the majority of H. influenzae (type b) isolates have evolved from common ancestors, giving rise to globally distributed organisms that have clonal characteristics.

Risk of subsequent disease among day-care contacts of patients with systemic Hemophilus influenzae type B disease

There is controversy about whether to provide rifampin prophylaxis routinely to contacts in day-care facilities of a patient with a primary case of Hemophilus influenzae type b disease. We prospectively investigated primary cases of H. influenzae type b disease in day-care facilities in Dallas County, Texas, to determine the rate of subsequent disease among contacts. Ninety-one children with primary cases of H. influenzae type b disease who were attending day-care facilities were enrolled from October 1982 to October 1984. A total of 587 classroom contacts of these children under four years of age were not given rifampin. During 60 days of follow-up, there was one subsequent case in a classroom contact. Untreated children under two years of age who were directly exposed to a patient with a primary case were considered to be at highest risk of disease, but there were no subsequent cases in this group of 361 children. However, there were two cases in new enrollees who started attending day-care facilities during the 60-day follow-up period but who were not exposed to a patient with a primary case. At day-care centers in which there was a second case during the follow-up period, there was a high prevalence of colonization with H. influenzae type b in both patient and nonpatient groups of preschool children. These data indicate that the rate of subsequent disease in classroom contacts of patients in day-care facilities is lower than that reported in households (1 of 587 vs. 20 of 829, P = 0.001) and that this rate may be similar to the base rate of primary disease in day-care facilities. We conclude that rifampin prophylaxis may not be appropriate after the occurrence of a primary case of H. influenzae type b disease in a day-care facility in Dallas County.

Five cases of Haemophilus segnis appendicitis

The clinical, histological, and bacteriological findings in five cases of acute appendicitis caused by Haemophilus segnis are reported. This is the first documentation of appendicitis associated with this organism.

Beta-lactamase production in the upper respiratory tract flora

In order to determine the recovery rate of species of the genera Haemophilus and Moraxella (including subgenus Branhamella) from the upper respiratory tract and the incidence of beta-lactamase production within these genera, cultures were made of nose and throat swab specimens and adenoid tissue in 50 children undergoing adenoidectomy. Haemophilus influenzae was isolated from 92% of the children. All children harboured strains of Haemophilus spp. and in 46%, at least one strain produced the TEM-1 beta-lactamase. Branhamella catarrhalis and/or Moraxella nonliquefaciens were isolated from 82% of the children and strains producing the BRO-1 beta-lactamase from 34%. Overall, TEM-1 and/or BRO-1 producing strains were recovered from 60% of the investigated patients. The beta-lactamase production was found to be transferable by conjugation within the respective genera. It is suggested that the apathogenic species may be a source of transferable determinants mediating beta-lactamase production in the upper respiratory tract.

Deoxyribonucleic acid relatedness between Haemophilus aegyptius and Haemophilus influenzae

Haemophilus aegyptius should be considered a junior subjective synonym of Haemophilus influenzae. Both nomenspecies are indistinguishable by DNA/DNA hybridization (S1 nuclease method). No single phenotypic test can unambigously separate H. aegyptius from the other biotypes of H. influenzae.