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Biomedical subjects

G Colman

Publications and source records attributed to G Colman.

At least 19 recordsLinked to original sources
PubMed1998

Pneumococci causing invasive disease in Britain 1982-1990.

A total of 5348 isolates of Streptococcus pneumoniae was serotyped and screened for insusceptibility to tetracycline, penicillin, erythromycin and chloramphenicol. Of these, 4238 (79%) were isolated from patients who had pneumonia or meningitis or were bacteraemic. Altogether, 3948 (74%) of the isolates belonged to one or other of the serotypes 1, 3, 4, 6, 8, 9, 14, 19 or 23 with serotypes 6, 14, 18, 19 and 23 being frequent causes of invasive disease in young children. Many isolates of type 1 were isolated from pneumonia and few from meningitis. Some 768 (14%) isolates were insusceptible to one or more antibiotic and 591 of these belonged to serotypes 6, 9, 14, 19 or 23. Representatives of type 14 resistant to erythromycin were prominent from 1986 onwards. There was an increase in the number of multi-resistant pneumococci from 1985. Among these were isolates of type 23 insusceptible to penicillin, chloramphenicol and tetracycline and cultures of type 6 resistant additionally to erythromycin.

Adolescent↗
PubMed1994

Biochemical differences among human and animal streptococci of Lancefield group C or group G.

Pyogenic streptococci of Lancefield group C or group G from human or animal sources were examined with a view to increasing the number of diagnostic tests useful for their differentiation. Human strains of group G produced L-prolyl-L-arginine aminopeptidase but isolates of Streptococcus equisimilis (group C) did not. Tests for alpha-L-glutamate aminopeptidase together with fermentation of glycogen or sorbitol distinguished S. dysgalactiae from strains of S. equisimilis isolated from animals. It was confirmed that fermentation tests were helpful in the study of S. equi and S. zooepidemicus and that enzyme reactions helped distinguish between S. canis and the human strains of group G.

Aminopeptidases↗
PubMed1993

The serotypes of Streptococcus pyogenes present in Britain during 1980-1990 and their association with disease.

A total of 16,909 cultures of Streptococcus pyogenes (Lancefield group A) isolated in Britain during 1980-90 were examined for T- and M-protein antigens. One or other M antigen was detected in 92.6% of the strains. The numbers of isolates of some serotypes, such as M3 and M12, did not show great variation from year-to-year, whereas there were nationwide epidemics, extending over several years, caused by strains of serotypes M1 and M49. Isolates of serotypes M1 and M3 were associated particularly with invasive disease and fatal infections. Representatives of serotypes M80, M81 and the provisional types PT180, PT1658 and PT5757 were isolated most often from cases of pyoderma. Erythromycin resistance was detected in 30 serotypes but one half of all of the resistant isolates belonged to serotype M4.

Bacteremia↗
PubMed1992

Screening tests for pathogenic corynebacteria.

AIM: To provide simple tests that would help in the identification of corynebacteria that produce diphtheria toxin. METHODS: A collection of 99 freshly isolated corynebacteria was assembled and the cultures identified by conventional tests confirmed by an identification kit. Modifications were made to procedures for preparation of the culture medium for the Elek test and to the test for detection of pyrazinamidase (pyrazine carboxylamidase) activity. These two together with an indicator medium for cystinase activity were applied to the collection of organisms. RESULTS: Cystinase was detected in all 61 members of the toxigenic species and none produced pyrazinamidase. In contrast, all but two of the 38 representatives of non-toxigenic species yielded pyrazinamidase and none formed cystinase. Of the 61 cystinase producing cultures (which were also pyrazinamidase negative), 21 gave a positive Elek test with the modified culture medium. A total of 30 of these 61 were tested for toxigenicity in guinea pigs and the results of the animal and plate tests concorded. At least seven cultures could have been reported as non-toxigenic if Elek tests based on media prepared in the conventional way had been the only test available. CONCLUSION: The three procedures described go some way towards meeting the needs of diagnostic laboratories for efficient procedures for distinguishing pathogenic corynebacteria.

Amidohydrolases↗
PubMed1992

The role of streptococcal infection in the initiation of guttate psoriasis.

BACKGROUND AND DESIGN: Although the association between streptococcal infection and guttate psoriasis is well known, to date there has been little information on whether only limited groups and/or serotypes of beta-hemolytic streptococci are involved. One hundred eleven patients with a sudden onset or deterioration of psoriasis were investigated for evidence of streptococcal infection. Of these patients, 34 had acute guttate psoriasis, 30 had a guttate flare of chronic psoriasis, 37 had chronic plaque psoriasis, and 10 had other types of psoriasis. RESULTS: Serologic evidence of recent streptococcal infection was present in 19 (58%) of 33 patients with acute guttate psoriasis compared with seven (26%) of 27 patients with guttate exacerbations of chronic psoriasis. Streptococcus pyogenes was isolated from 19 (17%) of all 111 patients (9 [26%] of 34 with acute guttate psoriasis, four [13%] of 30 with guttate exacerbations of chronic psoriasis, and five [14%] of 37 patients with chronic psoriasis) compared with seven (7%) of 101 of a control population of patients being seen for treatment of viral warts. Other beta-hemolytic streptococci were found with equal frequency in the study and control populations. Thirteen isolates of 10 different streptococcal serotypes were obtained from the 64 patients with guttate psoriasis. These serotypes were similar in distribution and prevalence to those present in the local community. CONCLUSIONS: This study confirms the strong association between prior infection with S pyogenes and guttate psoriasis but suggests that the ability to trigger guttate psoriasis is not serotype specific.

Antibodies, Bacterial↗
PubMed1991

Streptococcus pyogenes vulvovaginitis in children in Nottingham.

Isolates of Streptococcus pyogenes from vaginal swabs of children with vulvovaginitis received at Nottingham Public Health Laboratory during 1986-9 were studied. A total of 159 isolates was made during the 4 years, increasing from 17 in 1986 to 64 in 1989 and accounting for 11% of all vaginal swabs received from children. The numbers of throat swabs yielding S. pyogenes also showed an increase from 974 in 1986 to 1519 in 1989. A winter peak of isolates was noted for both vaginal swabs and throat swabs. A total of 98 strains from vaginal swabs were serotyped: 22 different types were identified, 61% of which were the common types M4, M6, R28 and M12. Erythromycin sensitivity was done on 89 strains; 84% were highly sensitive (MIC less than 0.03 mg/l). There are no other reports of such large numbers in the literature; the reason for seeing this increase in Nottingham is unclear.

Child↗
PubMed1990

Streptococcal serotypes newly associated with epidemic post-streptococcal acute glomerulonephritis.

The increasing incidence of reported scabies in Trinidad, from 24.2/100,000 population in 1984 to 59.5/100,000 in 1985, led to a careful monitoring in 1986 of all patients with post-streptococcal acute glomerulonephritis (PSAGN). There were 181 cases of PSAGN; 84 beta-haemolytic streptococcal isolates from 72 patients were sent to the Central Public Health Laboratory, Colindale, for grouping and serotyping. The PSAGN epidemic of 1986 was bimodal. Streptococci of M-type 73 appeared to be associated with the first phase (March-May) and comprised 20% of the isolates serotyped. New to Trinidad, streptococci of M-type 48 (4% of the isolates serotyped) preceded the first phase of the epidemic and were isolated from two patients with PSAGN. Provisional type (PT) 5757, also new to Trinidad, had been previously identified only among serotypes from the United Kingdom and the Federal Republic of Germany. This type was isolated from seven patients, in six from skin lesions and in one from the throat. PT 5757 occurred during the first wave of the epidemic and comprised 14% of the strains serotyped. Thus, the first wave of the bimodal epidemic involved serotypes M73, M48 and PT 5757. The more intense second phase (July-October) was associated with the previously documented nephritogenic M-type 55.

Acute Disease↗
PubMed1990

Detection of diphtheria toxin in culture supernates of Corynebacterium diphtheriae and C. ulcerans by immunoassay with monoclonal antibody.

Monoclonal antibody (MAb) to diphtheria toxin was produced in mouse hybridomas, and shown by ELISA to be of sub-class IgG1. Hybridomas were inoculated into mice to produce ascitic fluid from which MAb was purified by caprylic acid. The MAb was shown by immunoblotting to be directed against the A fragment of the toxin and also against the intact toxin molecule. After conjugation with fluorescein isothiocyanate, it was used in an immunoassay to detect toxin in culture supernates of Corynebacterium diphtheriae and C. ulcerans. The assay correlated well with the Elek test and with virulence in guinea-pigs; but it gave occasional false positive results, probably by binding of MAb to defective toxin.

Animals↗
PubMed1989

The presence of M proteins in outbreak strains of Streptococcus equisimilis T-type 204.

Cultures of Streptococcus equisimilis (Lancefield group C) from three outbreaks of illness were found to carry the T-protein antigen 204. Strains of this type were not otherwise represented in a collection of 743 cultures of these 'pyogenes-like' streptococci isolated from other outbreaks of infection or as random isolates. Two of the three outbreaks were of pharyngitis. The third arose in a maternity unit where the organism was isolated from mothers with puerperal fever, from staff and also from the environment. Representative strains were found to carry M-protein antigens as judged by their ability to survive and multiply in fresh normal human blood. Comparison of absorbed rabbit antiserum to the M antigens in opsonic and precipitin tests showed that a distinct M antigen was present on isolates from one outbreak of sore throat and that all cultures from the other two incidents shared a common M antigen. Samples of serum were also available from patients in the outbreak of puerperal sepsis. Most patients developed antibodies to one or more streptococcal antigens including the M protein, streptolysin O, streptokinase and the hyaluronidase specific for strains of group C and group G streptococci.

Antigens, Bacterial↗
PubMed1988

Typing of Streptococcus agalactiae (Lancefield group B).

A two-stage typing scheme in routine use in this laboratory is described. The strains of group B streptococci (GBS) are first serotyped and then, if necessary, phage-typing is performed. Serotyping lacks discrimination because almost 40% of strains handled carry either the Ia/c or III/R antigens. On the other hand, the typability rate with phages is less than 80%. The evidence from the combined scheme is consistent with the view that GBS infections occurring within the first five days of life are, with few exceptions, due to acquisition of the mother's flora. After this time the infecting strain may come from other sources. Human and bovine strains of GBS belong predominantly to two recognizably different populations that can be distinguished by antigenic and biochemical differences. There are no patterns of lysis by phages characteristic of either human or bovine strains.

Animals↗
PubMed1988

Changes in the pattern of infection caused by Streptococcus pyogenes.

The distribution of T- and M-protein antigens was determined in 12,469 cultures of Streptococcus pyogenes sent to a reference laboratory. Of these 7232 (58%) were isolates from hospital patients, 249 (2%) from hospital staff and 4988 (40%) from the community. The survey extended from January 1980 to June 1987. During this time the numbers of isolates of M-types 6, 49 and 81 rose then fell, being replaced by types 1, 3 and 28. The proportion of isolates of M-types 4 and 12 remained constant. Few strains were received from cases of nephritis or rheumatic fever but there has been an increase in the number of strains from serious infections and deaths. Forty-four of the 55 (80%) strains received since 1985 from fatal infections have belonged to M-type 1. All other strains, bar two, received from fatal infections in those years belonged to M-type 3. Representatives of M-type 1 were also associated with erysipelas. Types 3 and 4 predominated among the isolates from scarlet fever, types 1, 4, 12 and 49 from nephritis, types 49 and 81 from skin infections in meat workers and type 28 in cases of puerperal sepsis. The M-typability rate was 97% but new M antigens await definition among strains causing pyoderma.

Agglutination Tests↗
PubMed1988

Patterns of carriage of group B streptococci in genitourinary medicine clinic patients.

Anogenital carriage of group B streptococci was found in 46% (57/125) of men and 38% (68/179) of women attending a genitourinary medicine clinic. Colonisation with group B streptococci was more common in patients who had a history of more than one sexual partner in the preceding three months, but was not related to any previous sexually transmitted infection. Group B streptococci were isolated from either one or both partners of 28 couples, in 12 of which both partners yielded isolates that were indistinguishable by serotyping and phage typing. Colonisation with matching isolates of group B streptococci was more common in couples who had relatively stable relationships.

Adult↗
PubMed1987

Unusual occurrence of an epidemic of type Ib/c group B streptococcal sepsis in a neonatal intensive care unit.

An epidemic of late-onset sepsis due to type Ib/c group B Streptococcus (Ib/c-GBS) occurred in a neonatal intensive care unit (NICU). During a seven-week period, five very low birth weight infants (index cases [ICs]) more than four weeks of age became bacteremic. Bacteriologic surveillance of neonates revealed persistent colonization in three ICs and identified three asymptomatic carriers (ACs). All ICs and one AC acquired Ib/c-GBS nosocomially, whereas the other two ACs were colonized at birth. Among nursery personnel, 39% carried GBS, but only two harbored Ib/c-GBS. Although phage typing of Ib/c-GBS isolates identified two patterns of susceptibility, we believe a single strain was involved in the epidemic, because the patterns overlapped and most isolates carried the same lysogenic phage. Analysis of events suggested infant-to-infant spread via the hands of personnel, but acquisition from the colonized staff was also possible. The control measures instituted prevented further spread of Ib/c-GBS in the NICU.

Anti-Bacterial Agents↗
PubMed1987

Biotyping, serotyping and phage typing of Streptococcus faecalis isolated from dental plaque in the human mouth.

Thirty Streptococcus faecalis isolates from mixed dental plaque samples were classified into four groups on the basis of biotype, tetracycline susceptibility, phage type and serotype combinations. The organisms were from patients on haemodialysis, from staff of the dialysis unit, and from controls. Three biotypes were distinguished by seven biochemical tests: production of acid from inositol, sucrose and xylose; rapid or delayed production of acid from sorbitol; gelatin liquefaction; and production of alkaline phosphatase and beta-galactosidase. With a set of eight typing antisera for S. faecalis, 15 strains were non-typable, 12 were serotype 1 and three were serotype 19. With a set of 17 bacteriophages specific for S. faecalis, all of the oral isolates were typable; 40% were lysotype I1 and the remainder lysotype V6b. On the basis of biotype-serotype-phage-type combinations, indications of possible spread of strains between haemodialysis patients and dialysis unit staff were obtained. Biotyping and serotyping of 13 German isolates of S. faecalis of phage type I1 from four clinical sources and tripartite typing of three control strains provided additional evidence for the potential of biotyping in distinguishing between strains of identical serotype and phage type. One oral isolate of S. faecium was of phage type XX. None of the oral isolates of S. faecalis, of which 14 exhibited delayed sorbitol fermentation, reacted with group-G streptococcal grouping reagents or antiserum. Slow sorbitol fermentation does not appear to be a definitive phenotypic marker for S. faecalis strains possessing antigens that react with both group-D and group-G grouping reagents.

Adolescent↗
PubMed1985

The value of bacteriology and serology in the diagnosis of cellulitis and erysipelas.

Patients diagnosed as suffering from erysipelas or cellulitis were subjected to bacteriological and serological investigations. The serological tests used included the anti-streptolysin O reaction (ASO), the anti-deoxyribonuclease B test (ADB) and the anti-hyaluronidase tests (AHT) that are specific both for the group A streptococcus (Streptococcus pyogenes) and for the human pyogenic streptococci of group C or group G. Antibody tests to the alpha-lysin and the nuclease of Staphylococcus aureus were also employed. Conventional bacteriological culture methods were used plus needle aspiration of injected saline in most patients with erysipelas, but recognized pathogens were isolated in only 42% of cases. Our results indicate the limitations of these tests for making initial diagnoses and deciding treatment. Serial serological testing was very successful in differentiating cellulitis due to group A, C or G haemolytic streptococci, or occasionally Staphylococcus aureus, but was positive in only 40% of cases of erysipelas.

Adult↗