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Biomedical subjects

D Hansman

Publications and source records attributed to D Hansman.

At least 55 records · Page 3Linked to original sources

Antibody response to pneumococcal vaccine in children aged 5 to 15 years.

The type-specific antibody response of 99 healthy children, aged 5 to 15 years, to a 14-valent pneumococcal vaccine was determined and analyzed according to age at the time of vaccination. The response to the majority of the serotypes, including the important "pediatric" types 6A, 18C, and 19F, appeared to plateau in the 8- to 10-year-old age group, whereas for types 14 and 23F, which are also important in children, the response continued to improve with age to ages 13 to 15 years. The antibody response of a group of 23 children, aged 5 to 15 years, with various hematologic disorders (12 of whom had undergone splenectomy) was also determined and compared with that of the healthy children. For all serotypes the antibody response was similar in the two groups.

Adolescent↗

Pneumococcal carriage and type-specific antibody. Failure of a 14-valent vaccine to reduce carriage in healthy children.

No consistent effect on nasal carriage rates of Streptococcus pneumoniae belonging to vaccine types was observed during a randomized, controlled trial of a 14-valent pneumococcal vaccine, which included 1273 Australian children aged 6 to 54 months. Nasal carriage of S pneumoniae was associated with a significantly elevated homotypic serum antibody concentration for types 18C, 19F, and 23F, but not for types 6A and 14 (these five types are the most important causes of pneumococcal infections in children). Upper respiratory tract carriage seems to play an important role in natural acquisition of antibody to some but not all pneumococcal serotypes. These findings help to explain why pneumococcal vaccine fails to protect young children from acute otitis media.

Antibodies, Bacterial↗

Cloning and expression in Escherichia coli of the Streptococcus pneumoniae gene encoding pneumolysin.

A gene bank of Sau3A1-generated Streptococcus pneumoniae DNA fragments was constructed in Escherichia coli K-12 by cloning into the BamHI site of the cosmid vector pHC79. Clones expressing the pneumolysin determinant were selected by testing for hemolytic activity which could be inhibited by antibody to purified pneumolysin and by cholesterol. Restriction analysis of pneumolysin-positive recombinant cosmid DNA indicated that the coding sequence for the toxin was located within a 2.9-kilobase-pair (kbp) ClaI DNA fragment. This fragment, which included 0.35 kbp of vector pHC79 DNA, was subcloned into the plasmid pBR322. E. coli cells harboring this recombinant plasmid (designated pJCP20) produced approximately one-third of the amount of pneumolysin found in the donor S. pneumoniae strain. Plasmid pJCP20 was stably maintained in E. coli and resulted in the accumulation of active pneumolysin in the cytoplasm. Western blot analysis showed that E. coli harboring pJCP20 produced two forms of the toxin with molecular weights of 54,000 and 52,000. The lower-molecular-weight form was indistinguishable from native pneumolysin. Subcloning the 2.9-kbp DNA fragment into the expression vector pEV31 allowed the determination of the direction of transcription of the pneumolysin gene. The pneumolysin-coding sequence (approximately 1.5 kbp) has been localized to within a 1.75-kbp segment of pneumococcal DNA.

Bacterial Proteins↗

Multiply-resistant Haemophilus influenzae type b causing systemic disease in children in Australia.

Until 1984 strains of Haemophilus influenzae type b (Hib) isolated from children with systemic infections in Australia had been uniformly sensitive to chloramphenicol. In July 1984 a child with bacteremia in Adelaide, South Australia, yielded a strain of Hib resistant to ampicillin, chloramphenicol and tetracycline. In October and November 1984 similar isolates were obtained on cerebrospinal fluid culture from 2 children with meningitis. The 3 isolates showed an identical resistance pattern and inactivated ampicillin and chloramphenicol. Each isolate was fully sensitive to moxalactam (latamoxef), and to cefotaxime. Both children with meningitis were treated initially with ampicillin and chloramphenicol given intravenously. One of these, a girl aged 16 mth, showed no improvement and a sixth cranial nerve palsy developed. When ampicillin and chloramphenicol were ceased and moxalactam was substituted there was a rapid clinical improvement. As initial therapy in children with bacterial meningitis we advocate using either moxalactam and ampicillin in combination or a suitable third generation cephalosporin such as cefotaxime.

Anti-Bacterial Agents↗

Pneumococcal carriage amongst Australian aborigines in Alice Springs, Northern Territory.

In Alice Springs and its vicinity, a single nasal swab was collected from 282 Australian aborigines in May 1981 to determine nasal carriage rates of pneumococci. Each swab was inoculated on blood agar and on gentamicin blood agar. The carriage rates were 89% in children, 39% in adolescents and 34% in adults. In all, 27 serotypes of pneumococci were met with and 15 (4%) of subjects yielded two or more serotypes. In children, types 23, 19, 6, 22 and 6 were predominant (in that order), whereas type 3 was commonest in older subjects. Approximately 25% children and 5% adults yielded drug-insensitive pneumococci. Resistance to benzylpenicillin, tetracycline and co-trimoxazole was met with, resistant pneumococci showed five resistance patterns and belonged to nine serotypes, predominantly types 19 and 23. All isolates were sensitive to chloramphenicol, erythromycin, lincomycin and rifampicin. The carriage rate of drug-insensitive pneumococci was 100-fold higher amongst children sampled than in non-aboriginal children in Australia.

Adolescent↗

Serotype distribution of meningococci isolated in South Australia 1971 through 1980.

The serotypes of meningococci isolated from 76 sporadic cases of meningococcal disease in South Australia during the years 1971 through 1980 were determined. Thirty-four (56%) of the 61 group B strains were nontypable; the remainder were of five serotypes namely 8 (16%), 1 (13%), 2 (2a and 2b) (9%), 12 (3%), and 15 (3%). Four of the five group B type 2 strains were serotype 2b. Serotype 2a accounted for four of seven group C strains and four of five group W135 strains. Overall serotypes 2 (2a and 2b) (17%), 8 (13%), and 1 (10%) occurred most frequently amongst the typable strains, whereas 40 (53%) of the 76 strains were nontypable. The results indicate that several serotypes and many nontypable strains were responsible for the sporadic disease occurring during a 10-year period in Australia.

Australia↗

Acute tonsillitis in children: microbial pathogens in relation to age.

Tonsil swabs were collected from 248 children (1 through 10 yr) who presented with acute tonsillitis. A beta-hemolytic streptococcus was grown from 129 (53%) of 244 cases and as the sole pathogen from 83 (47%) of 178 cases. Beta-Hemolytic streptococci were especially common over the age of 6 yr (68% of children) relatively uncommon under the age of 4 yr (18%); most (90%) streptococci belonged to group A; 18 streptococcal T types were represented amongst 88 group A strains; the potentially nephritogenic serotypes 4 and 12 were prominent and accounted for 42 (47%) of typable isolates. Eight (8%) of 96 unmatched children (1 through 10 yr) who served as controls were found to be carrying beta-hemolytic streptococci, 5 of which belonged to group A. A virus was grown from 52 (29%) of 182 children and as the sole pathogen from 40 (22%) of 178 children. Only echoviruses (8 serotypes) and adenoviruses (5 serotypes) were common; younger children showed a higher isolation rate of viruses. The clinical picture in children yielding a virus was indistinguishable from that of cases who yielded a beta-hemolytic streptococcus.

Acute Disease↗

Meningococcal disease in South Australia: incidence and serogroup distribution 1971-1980.

During the ten-year period 1971-80 isolates of meningococci from 85 cases of meningococcal disease (MD) in South Australia, from 66 children, 6 adolescents and 13 adults, were examined. These comprised 69 cases of meningitis and 16 cases of bacteraemia without meningitis. Thirty-three (39%) of all cases of MD occurred in children less than 1 year of age, the median age was 19 months. Serogroup B accounted for 61 (72%) cases of MD, group A seven (8%), group C seven (8%), group W135 five (6%), group Y three (4%) and group X one (1%); in addition there was a single case of Neisseria lactamica infection. The annual prevalence of MD in South Australia for the period was 11 cases per 100000 for children under the age of 2 years and 0.7 cases per 100000 overall. The prevalence was highest in winter (45% cases) and spring (26%) and lowest in summer (13%). The overall mortality rate was 8%. Four of the 21 infants under the age of 6 months died (mortality rate 19%) whereas none of the 32 children aged from 6 months to 14 years died (P = 0.02). Amongst the survivors, three children had deafness, which was bilateral and severe in two.

Adolescent↗

Serotypes in pneumococcal disease. A ten year study in Australia 1970 through 1979.

During the ten year period 1970 through 1979, pneumococci from 1205 episodes of pneumococcal disease affecting children and adults in Australia were studied. These included 188 cases of bacteremic pneumonia (85% in adults), 103 cases of primary bacteremia (50% adults), 201 cases of meningitis (69% children), 13 cases of osteomyelitis and/or arthritis, and 13 cases of peritonitis. Otitis media (403 cases), conjunctivitis and sinusitis were predominant amongst 672 localised infections. Of 36 serotypes of pneumococci met with, the leading types were 19, 14, 6, 3 and 9: type 14 predominated in children with primary bacteremia, bacteremic pneumonia or meningitis, type 9 in adults with bacteremic pneumonia, and types 3 and 7 in adults with meningitis. In otitis media types 19 and 3 predominated, in conjunctivitis types 19 and 6, and in sinusitis types 6 and 19. For bacteremic and meningeal infections the current (United States) vaccine provides 83% cover, deletion of the rare (in Australia) types 2, 12 and 25 and the substitution of types 11, 15 and 33 would increase cover by 5% to 88%.

Adolescent↗

Campylobacter as a cause of acute enteritis in children in South Australia. I. A 12-month study with controls.

During a 12-month period, we tested faecal samples from 386 children with acute enteritis and 332 controls by light and electron microscopy, and by bacterial and viral culture for pathogens, especially to assess the importance of campylobacter. Campylobacter alone was responsible for the illness in 17 patients (5%), and was second to salmonella among the bacterial agents, which were predominant in summer. Overall, rotavirus was the commonest identifiable cause of acute enteritis and was especially important in winter (with a rate of 49% in August). Thirty-five patients showed two or more agents. In 117 patients (30%) no pathogen was isolated or identified, suggesting that there are as yet unidentified agents in acute enteritis.

Acute Disease↗