PubMed Health⌕ Search

Biomedical subjects

C S Easmon

Publications and source records attributed to C S Easmon.

At least 37 records · Page 2Linked to original sources
PubMed1989

Interaction of meropenem with humoral and phagocytic defences.

Meropenem and imipenem were compared for their capacity to kill intracellular Staphylococcus aureus, to alter the pattern of lysis of serum-sensitive or resistant Escherichia coli, and to affect the uptake and intracellular killing of opsonized S. aureus by human neutrophils and mouse peritoneal macrophages. Meropenem killed intracellular S. aureus at concentrations equal to eight times the MBC while imipenem did not. Neither antibiotic had any significant effect on any of the other interactions studied.

Antibody Formation↗
PubMed1989

Characterisation of monoclonal antibodies for detection of Mobiluncus spp. in genital specimens.

Monoclonal antibodies were raised to the anaerobic curved rods, Mobiluncus curtisii subsp. curtisii NCTC 11656, M. curtisii subsp. holmesii NCTC 11657 and M. mulieris NCTC 11658. Three antibodies reacted with the two subspecies of M. curtisii and, when used in combination against clinical isolates, showed 100% sensitivity and specificity in immunofluorescence studies. Immunoblotting showed that two of these antibodies reacted with an epitope on a protein which had an electrophoretic mobility corresponding to a Mr of 75 Kda in the absence of a reducing agent and 82 Kda in its presence in both type strains and in clinical isolates. The third antibody reacted with an epitope in type strains which had a mobility corresponding to 75 Kda and was unaffected by a reducing agent. However, in clinical isolates the epitope was present on a protein of 75 Kda or 71 Kda, or on both. A fourth antibody showed reactivity with M. mulieris NCTC 11658 alone, but only 6 (24%) of 25 clinical isolates gave positive results by immunofluorescence. The epitope is believed to be present on a protein of greater than 90 Kda. All four antibodies were shown by immunogold staining to be directed against epitopes exposed on the cell surface.

Antibodies, Bacterial↗
PubMed1989

Changes in penicillinase-producing Neisseria gonorrhoeae isolated in London.

To investigate changes in the gonococcal population over time, the plasmid content, serotype and auxotype have been determined for strains of penicillinase-producing Neisseria gonorrhoeae (PPNG) isolated from patients attending the Praed Street Clinic for Sexually Transmitted Diseases between 1978 and 1987. Three distinct changes have been identified: (i) in the main plasmid type, from PPNG with the 3.2-Mda plasmid before 1982 to strains with the 4.4-Mda plasmid between 1982 and 1985; (ii) the decline during this time of strains also carrying the 24.5-Mda conjugal plasmid; (iii) the re-emergence of PPNG with the 3.2-Mda plasmid in 1986. The three typing methods used have identified eight clusters of strains which have been prevalent in different years between 1978 and 1987.

Bacterial Typing Techniques↗
PubMed1989

Associations between serotype and susceptibility to antibiotics of Neisseria gonorrhoeae.

A serological classification scheme for Neisseria gonorrhoeae was used to investigate the epidemiological associations between gonococcal serotype and other bacterial and host characters. Six hundred and fifty clinical isolates of non-penicillinase producing N gonorrhoeae from the Praed Street Clinic, St Mary's Hospital, were included in this study. The strains collected represented 41 serovars, although 485 (75%) of the 650 strains belonged to five serovars. Strains of serovar IA-1/2 were commonly isolated from the cervix and tended to be sensitive to penicillin and moderately resistant to erythromycin. Strains of serovar IB-1 showed bimodal patterns of susceptibility to both penicillin and erythromycin and were obtained equally from all anatomical sites. Strains of serovar IB-2 were isolated more often from the rectum and were associated with homosexually acquired infections, whereas those of serovar IB-3 were sensitive to erythromycin and were rarely isolated from the rectum. Strains of IB-5/7 were more resistant to penicillin and erythromycin than strains of other serovars. The serological classification of N gonorrhoeae is thus a powerful tool that may be used to study biological characteristics of the gonococcus, such as susceptibility to antimicrobials and site tropism.

Anti-Bacterial Agents↗
PubMed1989

Rapid detection of Haemophilus ducreyi in clinical and experimental infections using monoclonal antibody: a preliminary evaluation.

A monoclonal antibody raised against Haemophilus ducreyi was tested for its sensitivity and specificity as an immunofluorescence (IF) reagent using simulated vaginal smears containing H. ducreyi, smears taken from skin lesions of mice infected with H. ducreyi and patients from South Africa, Thailand and Malaysia with clinically diagnosed chancroid. The IF test was more sensitive than culture or Gram staining in the simulated smears, theoretically detecting less than 4 organisms/sample. It detected H. ducreyi in 95% of the animal lesions compared with 14% detected by culture. Immunofluorescence testing identified over 90% of culture-positive cases of chancroid but also detected organisms in some culture-negative cases where clinical evidence for the diagnosis was strong. These results suggest that this antibody may provide a simple, rapid and sensitive means of detecting H. ducreyi in cases of chancroid.

Animals↗
PubMed1988

Comparison of the opsonic activity of polyclonal and monoclonal antibodies raised against Salmonella minnesota strain R595.

Murine monoclonal antibodies and immune rabbit serum were raised against the rough mutant Salmonella minnesota strain R595. These antibodies were tested for their opsonic activity against the homologous strain and the smooth wild type S. minnesota by luminol-dependent chemiluminescence and a microscopic assessment of phagocytosis. Immune rabbit serum opsonised both strains. Treatment with normal rabbit serum inhibited the phagocytic uptake of S. minnesota R595. None of the monoclonal antibodies RE01 (anti-KDO), RE12 (anti-KDO) and RE23 (anti-lipid A) were opsonic. Unopsonised S. minnesota R595 stimulated marked chemiluminescence possibly because of its hydrophobic surface, but this was not reflected in increased uptake by phagocytic cells. Results obtained with luminol-dependent chemiluminescence should be interpreted with caution when the opsonisation of rough bacterial strains or those with high surface hydrophobicity is being investigated.

Animals↗
PubMed1988

Evaluation of a fluorescent monoclonal antibody reagent for identification of cultured Neisseria gonorrhoeae.

We evaluated a new fluorescent monoclonal antibody reagent for confirmation of identity of Neisseria gonorrhoeae. The reagent correctly identified all 161 fresh clinical isolates of N. gonorrhoeae, which included 11 penicillinase producing strains (PPNG). The reagent also correctly identified 21 stored PPNG strains. No cross reactions were seen with 58 fresh clinical isolates of N. meningitidis, 12 stored strains of N. lactamica, or with strains of Gardnerella vaginalis, lactobacilli, Candida spp., Staphylococcus epidermidis or Enterobacteriaceae. Some cross reaction was noted with strains of S. aureus, probably related to cell-wall protein. A. However, this reagent was highly sensitive and specific for use against oxidase positive, gram-negative cocci isolated in London.

Antibodies, Monoclonal↗
PubMed1988

Opsonophagocytosis of Campylobacter pylori.

The opsonic activity of human serum from various sources against Campylobacter pylori was compared. All sera, whether from control subjects with no symptoms of gastritis or peptic ulceration, or from symptomatic patients from whom C. pylori had or had not been isolated, opsonised C. pylori equally well. Opsonisation depended on the alternative pathway of complement activation but not on antibody. These findings suggest that antibody plays no role in protection against C. pylori and that the presence of antibody in patients' sera is mainly of diagnostic value.

Antibodies, Bacterial↗
PubMed1988

Characterization of aromatic- and purine-dependent Salmonella typhimurium: attention, persistence, and ability to induce protective immunity in BALB/c mice.

Stable transposon-generated auxotrophic mutations in aroA, purA, and purE or aroA and purA together were introduced into Salmonella typhimurium strains which were virulent in mice. Strains harboring any of these mutations were attenuated when tested in BALB/c mice. purE strains were less attenuated than aroA or purA strains. Both aroA and purA mutants persisted for several weeks in the livers and spleens of the mice after intravenous infection, although the numbers of viable cells detected at various times after infection differed. aroA strains persisted at a higher level than purA strains and were effective live vaccines given intravenously or orally. purA strains were ineffective as oral vaccines and were poor intravenous vaccines. Strains harboring both aroA and purA mutations together were ineffective vaccines when administered orally or intravenously even though they persisted in the livers and spleens of the mice for long periods after intravenous infection.

Administration, Oral↗
PubMed1987

Suture materials in contaminated wounds: a detailed comparison of a new suture with those currently in use.

The relationship between five different suture materials (expanded polytetrafluoroethylene (PTFE), polypropylene, polyglycolic acid, polydioxanone and polyglactin 910) and infection has been studied in 540 guinea-pig wounds contaminated with synergistic enteric organisms. The recently introduced expanded PTFE suture has been studied because, unlike the others, it has not previously been studied under these contaminated conditions. The incidence of wound infection in the control series was 26 per cent and all suture materials increased this figure significantly. The infection rate using expanded PTFE of 51 per cent was similar to all other sutures except polyglycolic acid, which produced an infection rate of 41 per cent. This difference was not statistically significant at the 5 per cent level. This confirms other studies including our own which show that the presence of most suture materials in contaminated wounds increases the incidence of infection. It further demonstrates that expanded PTFE is no different from other materials in this regard.

Animals↗
PubMed1987

The activity of the 4 quinolone Ro 23 6240 and the cephalosporins Ro 15 8074 and Ro 19 5247 against penicillin sensitive and resistant gonococci.

We have compared the in-vitro activity of the 4-quinolone Ro 23 6240 and the oral cephalosporins Ro 15 8074 and Ro 19 5247 with that of penicillin, spectinomycin, cefuroxime, ceftriaxone, ciprofloxacin, ofloxacin and norfloxacin against 60 strains of Neisseria gonorrhoeae. MICs 90 against penicillinase producing N. gonorrhoeae (PPNG) and chromosomally-mediated resistant N. gonorrhoeae (CMRNG) respectively were: spectinomycin 16 and 16 mg/l, cefuroxime 0.12 and 1.0 mg/l, ceftriaxone 0.008 and 0.03 mg/l, Ro 15 8074 0.015 and 0.12 mg/l, Ro 19 5247 0.015 and 0.12 mg/l, Ro 23 6240 0.06 and 0.06 mg/l, ciprofloxacin 0.008 and 0.015 mg/l, ofloxacin 0.03 and 0.06 mg/l, norfloxacin 0.06 and 0.12 mg/l. The spectinomycin resistant and spectinomycin-sensitive strains did not differ. All three new agents show good activity against gonococci and warrant further clinical investigation. Ro 23 6240 in common with the other 4-quinolones appears to be as active against gonococcal strains exhibiting non-enzymic chromosomal resistance to penicillin as against PPNG and penicillin-sensitive isolates.

Anti-Bacterial Agents↗
PubMed1987

Enhancement of neutrophil chemiluminescence after elective gastrointestinal surgery.

Neutrophil count and luminol-dependent chemiluminescence were measured pre-operatively and on the second, sixth and ninth days after operation in nine patients undergoing major, elective gastrointestinal surgery. The aim of the study was to test the hypothesis that elective surgery as a form of injury has no prolonged deleterious effect on neutrophil activity in non-septic patients. A significant increase in neutrophil count was demonstrated in all patients at Day 2 (P less than 0.01) and Day 9 (P less than 0.01). Neutrophil chemiluminescence increased on Day 2 and Day 6, the increase on Day 6 being significant (P less than 0.02). In the first 9 days after elective gastrointestinal surgery, a biphasic neutrophilia occurs and the metabolic response of neutrophils to an opsonized particle is not impaired. These data would support the hypothesis that major elective surgery has no deleterious effects on neutrophil activity, and indeed that neutrophil activity may be enhanced.

Adult↗
PubMed1987

Neisseria gonorrhoeae: a versatile pathogen.

Neisseria gonorrhoeae is one of the most important causes of sexually transmitted disease. We do not fully understand the pathogenesis of infection with this organism, although recent improvements in immunological and molecular techniques have brought us closer to an answer. These techniques are now also being used to detect and identify N gonorrhoeae and to analyse the epidemiology of gonorrhoea. Plasmid and chromosomal mediated antibiotic resistance increases the difficulty of controlling gonorrhoea. Resistant strains occur all over the world and new patterns of resistance are still emerging. A better understanding of gonococcal pathogenicity is necessary for the development of an effective vaccine. Despite work on pili and outer membrane proteins no vaccine yet exists. The control of gonorrhoea still depends on diagnosis, treatment, and epidemiological control, facilities that are not widely available in many of those parts of the world where gonorrhoea is a major problem.

Drug Resistance, Microbial↗
PubMed1987

New microbial and host factors in disseminated gonococcal infection: case report.

Disseminated gonococcal infection was diagnosed in an immunocompromised patient who presented with oliogoarthropathy and tenosynovitis. The gonococcal isolate was prototrophic, showed intermediate resistance to penicillin, and belonged to serogroup WII/III. An isolate from the patient's sexual contact showed similar characteristics. The patient had a Saccharomyces opsonin defect, which is associated with childhood infections and has not been reported previously in association with disseminated gonococcal infection. The pathogenetic importance of the unusual isolate and the underlying host defence defect is considered.

Adolescent↗
PubMed1987

Development and evaluation of scheme for serotyping Gardnerella vaginalis.

Antibodies to Gardnerella vaginalis were raised in rabbits. Nine antisera that reacted with their immunising strains, but not with the remaining eight strains, were used to develop a serotyping scheme. A dot blotting technique was used, and complexes of antigen and antibody were visualised using anti-rabbit immunoglobulin linked to alkaline phosphatase. Of 91 clinical isolates used to evaluate the scheme, 79 (87%) were typable and 52 (57%) reacted with only a single antiserum. The antigens expressed were stable during growth on different media and on subculture. The specificity of the antibody was shown to be directed against different immunodominant proteins and possibly a carbohydrate.

Antibody Specificity↗
PubMed1987

Chromosomal resistance of gonococci to antibiotics.

Three hundred and twenty nine strains of non-penicillinase-producing Neisseria gonorrhoeae (non-PPNG) isolated from men and women were tested for their susceptibility to a range of antibiotics, and were also auxotyped and serogrouped. Nearly 6% (18) of 312 strains tested were resistant to 1 mg/l or more penicillin (compared with 4.4% of PPNG strains isolated in 1981). Many (198, 64%) strains showed intermediate resistance to penicillin (0.12-0.5 mg/l). Nearly 5% (15) of 312 strains tested were resistant to 0.5 mg/l or more cefuroxime, and there was a high degree of cross resistance between these two antibiotics. High levels of resistance to erythromycin and tetracycline were also found, and there was also appreciable cross resistance between these antibiotics and the beta lactam drugs. Resistance to spectinomycin was rare, and there was no cross resistance between spectinomycin and other agents tested. Levels of resistance between strains isolated from different anatomical sites did not differ, except that resistance to erythromycin was greater in rectal isolates. Four main auxotypes were detected. Strains requiring arginine, hypoxanthine, and uracil (AHU-) were more prevalent from the cervix. We have shown that there is an association between auxotype, serogroup, and level of sensitivity to penicillin, cefuroxime, and tetracycline.

Anti-Bacterial Agents↗