Search PubMed⌕ Search

Biomedical subjects

A Moyes

Publications and source records attributed to A Moyes.

At least 37 records · Page 2Linked to original sources
PubMed1994

Penicillin susceptibility testing of penicillinase producing Neisseria gonorrhoeae by the E test: a need for caution.

The penicillin MICs of 52 clinical isolates of penicillinase producing Neisseria gonorrhoeae (PPNG) and five reference strains were tested by agar dilution and the E test. All 52 PPNG were scored resistant (> or = 2 mg/L) by agar dilution whereas only 78.8% (41/52) and 82.7% (43/52) were classified as resistant by normal (0.016-256 mg/L) and low range (0.002-32 mg/L) E test MICs respectively. Isolates with an E test penicillin MIC > or = 0.19 mg/L should be checked by a specific test for beta-lactamase production.

Gonorrhea↗
PubMed1994

Rapid identification of pathogenic neisserias using the Identicult-Neisseria test.

A rapid enzymatic method using chromogenic substrates for the rapid identification of pathogenic neisseria (Identicult-Neisseria, Scott Laboratories Inc., CA, USA) was tested in parallel with the rapid carbohydrate utilization test (RCUT) and the Phadebact Monoclonal GC Test against 198 consecutive clinical isolates of oxidase-positive Gram-negative diplococci (118 Neisseria gonorrhoeae, 76 N. meningitidis and four N. lactamica). On initial testing the Identicult-Neisseria gave a 95% overall concordance (97.5% N. gonorrhoeae, 90.8% N. meningitidis) with the RCUT and Phadebact tests; the corresponding figures after repeat testing were 98% overall concordance (98.3% N. gonorrhoeae, 97.4% N. meningitidis). Two of the three strains of N. gonorrhoeae mis-identified as N. meningitidis on primary testing were also mis-identified on repeat testing. Seven strains of N. meningitidis were mis-identified on initial testing (six as Moraxella catarrhalis and one as N. lactamica) and two on repeat testing (both as Mor. catarrhalis). We conclude that the Identicult-Neisseria is not sufficiently reliable for the culture confirmation of gonococci and meningococci.

Agglutination Tests↗
PubMed1994

Gonococcal infection in Edinburgh and Newcastle: serovar prevalence in relation to clinical features and sexual orientation.

AIMS: The variable distribution of gonococcal serovars in different areas is well recognised but the factors that are important determinants of serovar prevalence are less clear. The aim of this study was to identify relevant clinical variables by comparing serovar prevalence in two cities over the same time period. METHODS: A prospective analysis of serovar prevalence was made between January and December 1992 in Edinburgh and Newcastle with respect to age, sex, sexual orientation, antibiotic sensitivity and presence of symptoms. RESULTS: 224 infective episodes of gonorrhoea were studied. The serovar distribution varied between the two cities with serovar 1B-1 being more common in Edinburgh (20/91 cf. 4/133, p < 0.01) and serovar 1B-6 more common in Newcastle (26/133 cf. 2/91, p < 0.01). Serovar 1A-2 was associated with heterosexual infection (35/114 in heterosexuals cf. 0/85 in homosexuals, p < 0.01) and was more sensitive to penicillin than average (39/39 1A-2 strains highly penicillin sensitive cf. 98/184 for all other strains, p < 0.01) whilst 1B-6 was mostly acquired through homosexual contact (22/26 cf. 63/142 for all other strains, p < 0.01) and tended to show reduced penicillin susceptibility (13/28 1B-6 strains less penicillin sensitive cf. 45/195 for all other strains, p < 0.01). Infection with serovar 1A-2 was significantly less often symptomatic in heterosexuals than average (15/33 asymptomatic 1A-2 infections cf. 17/59 for all other serovars, p = 0.015). Subgroup analysis of male heterosexual infections confirms an association between asymptomatic infection and serovar 1A-2 (2/14 asymptomatic 1A-2 infections cf. 1/72 for all other serovars, p = 0.02). The distribution of infections over the year differed between the cities. CONCLUSIONS: A variety of factors including penicillin sensitivity and virulence may be important in determining the prevalence of gonococcal serovars within a given area.

Adult↗
PubMed1994

Gonorrhoea in Aberdeen: a serovar analysis.

The serotyping of gonococcal isolates has enabled detailed studies of the epidemiology of gonorrhoea in different geographical areas. This study reports the patterns of infection found in 1992 in Aberdeen and relates these to a variety of clinical parameters. 140 cases of gonorrhoea were isolated the majority of which belonged to one strain (lA-2) in contrast to the diversity of strains seen in other Scottish cities. Most isolates were highly sensitive to penicillin and only 3 penicillinase producing strains were found. A low rate of infections in homosexual men is reported again in contrast to the situation seen in other geographically close cities. Compared to the rest of Scotland Aberdeen has a high prevalence of gonorrhoea.

Adolescent↗
PubMed1993

Serotype patterns of gonococcal infection in contact pairs.

The use of gonococcal serovars in studying the epidemiology of Neisseria gonorrhoeae is well established. Most studies assume that the isolated serovar remains stable in vivo indefinitely. This study was designed to observe the correlation between serovars isolated in patients naming each other as sexual contacts. The overall rate of discordant transmission episodes was 12% (26/220). There were however significantly more discordant transmission episodes for partners of patients infected with IB serovars than IA serovars: 19% (23/124) versus 3% (3/96) - p < 0.01. The overall prevalence of serogroup IB isolates although significantly higher at 53% (p < 0.01) was thought insufficient to account for the correlation between discordant pairs and serogroup IB infection. Reasons considered for the discrepancies in contact pairs included: problems of partner reporting involving inaccurate or incomplete information; technical problems with reagents; culture induced phenotypic variation in antigenic expression or differences in the in vitro recognition of epitopes; and antigenic differences resulting from genetic mutation within the Protein I gene. It was concluded that carefully planned and controlled prospective studies involving duplicate parallel testing of isolates from patients and their well documented partners are needed to assess the extent to which these various factors contribute to discordancies in serovars isolated from contact pairs. Serotyping should be combined with other methods such as auxotyping for detailed microepidemiological studies involving partner notification.

Bacterial Typing Techniques↗
PubMed1993

Comparative evaluation of AccuProbe culture identification test for Neisseria gonorrhoeae and other rapid methods.

The AccuProbe chemiluminescent culture identification test for Neisseria gonorrhoeae (Gen-Probe Inc., San Diego, Calif.) was assessed in a comparative evaluation with other rapid methods by using 269 isolates of oxidase-positive, gram-negative diplococci. Chemiluminescence was read with a PAL luminometer, and results were expressed as PAL light units (PLUs): the cutoff value for a positive identification was 1,500 PLUs. All 200 isolates of gonococci confirmed by carbohydrate utilization and serotyped with monoclonal antibodies were identified correctly by AccuProbe on initial testing. The API Quadferm system (Bio Merieux, Marcy l'Etoile, France) identified 95% (n = 190) of the gonococci correctly on initial testing and 99.5% (n = 199) on repeat testing, while the Phadebact Monoclonal GC test (Kara Bio Diagnostics AB, Huddinge, Sweden) identified 95.5% (n = 191) of the gonococci on both initial and repeat testing; 8 of the Phadebact-negative isolates were all of the same rare serovar (serovar 1B-17). The mean PLU for the gonococcal isolates was 9,014 (range 2,264 to 10,845) compared with a mean of 51 (range, 8 to 109) for the 69 nongonococcal isolates. We conclude that the AccuProbe culture confirmation test provides a rapid and accurate objective means of identifying cultured N. gonorrhoeae isolates.

Bacteriological Techniques↗
PubMed1993

Typing of Neisseria gonorrhoeae by auxotype, serovar and lectin agglutination.

A total of 267 strains of Neisseria gonorrhoeae, comprising 129 serogroup IA and 138 serogroup IB, isolated in Edinburgh over a two-year period were analysed to assess the discrimination given by three typing methods: auxotyping; serotyping using the Genetic Systems (GS) and Pharmacia (PH) monoclonal antibody panels; and lectin agglutination. Each typing system was assessed individually and in combination. Serotyping subdivided the strains into 14 GS and 18PH serovars. Auxotyping (Aux) yielded 11 separate auxotypes while lectin agglutination yielded 22 different reaction patterns (LP). The standard auxotype/GS serovar (A/S) classification system yielded 37 classes. Lectin agglutination allowed further subdivision of the main A/S classes. AHU/IA-2 strains,which accounted for 70% of IA strains, yielded nine different lectin patterns (A/S/LP classes). Likewise, lectin agglutination allowed subdivision of the main IB A/S classes. NR/IB-1, NR/IB-2 and NR/IB-3, which accounted for 28%, 38% and 20% respectively of the IB strains, yielded 7, 7 and 6 A/S/LP classes respectively. It was concluded that lectin agglutination is a useful adjunct to the standard A/S classification system for studying the micro-epidemiology of gonococcal infection.

Agglutination Tests↗
PubMed1992

An analysis of lectin agglutination as a means of sub-dividing gonococcal serovars.

Sixteen lectins were examined for their ability to agglutinate 298 strains of Neisseria gonorrhoeae. Seven lectins failed to agglutinate any of the strains; the remaining nine lectins gave 22 different agglutination patterns. The 298 strains were divided into 14 serovars with a single panel of monoclonal antibody typing reagents; lectin agglutination subdivided these into 57 serovar/lectin patterns. A combination of two monoclonal antibody serotyping panels divided the strains into 32 serovar combinations; lectin agglutination further subdivided these into 79 serovar/lectin patterns. There was no correlation between lectin pattern and serovar. Lectin agglutination is a simple supplementary typing method and could be particularly useful in micro-epidemiological studies.

Agglutination↗
PubMed1992

Enzyme immunoassay for anti-treponemal IgG: screening or confirmatory test?

AIMS: To review the performance of the Venereal Diseases Research Laboratory (VDRL) test and the Treponema pallidum haemagglutination assay (TPHA) as a combined screen for syphilis to provide a baseline for assessing screening by anti-treponemal IGG EIA. METHODS: Between 1980 and 1987 all serum samples were screened by both VDRL and TPHA tests. The FTA-ABS test was also used in suspected early primary syphilis, or when one of the other tests was positive. A positive result in a screening test was confirmed by quantitative testing. From 1988 all specimens were screened with an enzyme immunoassay (Captia Syph G) as a single screening test. RESULTS: Of the 44 primary, 47 secondary, and 38 early latent cases of syphilis, the VDRL and TPHA detected 32 (73%) and 31 (71%) of the primary cases; the combination detected 37 (84%). All 85 cases of cases of secondary and early latent infection were reactive in the TPHA test, whereas the VDRL was reactive in only 68 (80%). EIA had a reported sensitivity of 82% for primary infection. CONCLUSIONS: EIA can be used as a single screening test for detecting early syphilis because its results are comparable with those of the combined VDRL and TPHA tests. The conventional VDRL test should not be used as a single screening test.

Antibodies, Bacterial↗
PubMed1992

A serovar analysis of heterosexual gonorrhoea in Edinburgh 1986-90.

OBJECTIVE: To analyse the frequency of different gonococcal serovars within Edinburgh, Scotland and to describe changes that occurred in the frequency of such serovars over time. METHODS: All heterosexual patients with a diagnosis of gonorrhoea confirmed on culture between January 1986 and December 1990 had their gonococcal strain serotyped. Temporal changes in the prevalence of gonorrhoea and the serovar of the isolates were analysed. RESULTS: Isolates of Neisseria gonorrhoeae from 1356 episodes of gonorrhoea were serotyped. Three serovars, Bajk (IB-3/IB-6), Bacejk (IB-1/IB-2) and Aedgkih (IA-1/IA-2), dominated, occurring in two-thirds of all infections. Over the study period Bajk (IB-3/IB-6) and Aedgkih (IA-1/IA-2) isolates declined in frequency in parallel with an overall fall in the prevalence of gonorrhoea but Bacejk (IB-1/IB-2) persisted at a lower but fairly constant level. Despite a fall in the number of gonococcal infections the variety of new serovars being isolated fluctuated. CONCLUSIONS: The ability of some serovars to persist while others decline in incidence may be partially related to antibiotic sensitivities but other factors such as an ability to evade the immune response and transfer of serovars from one population group to another may also be important.

Antigens, Bacterial↗
PubMed1992

Syphilis diagnosis: screening by enzyme immunoassay and variation in fluorescent treponemal antibody absorbed (FTA-ABS) confirmatory test performance.

Four fluorescent treponemal antibody absorbed (FTA-ABS) test kits were evaluated with 86 treponemal and 84 non-treponemal sera selected with enzyme immunoassay (EIA). Agreement between all four kits was 63% for treponemal, and 50% for non-treponemal, sera. Discrepancies with treponemal sera were associated with low levels of antibody characterised by T. pallidum haemagglutination assay (TPHA) titres < or = 160 and a negative Venereal Diseases Research Laboratory (VDRL) test. Discrepancies with non-treponemal sera were significantly associated with false reactivity on screening with EIA. Possible reasons for the differences obtained between kits, the importance of screening policies for pre-selecting sera, and the significance of equivocal (borderline) reactions on positive and negative predictive values are discussed.

Evaluation Studies as Topic↗
PubMed1991

Epidemiological typing of Neisseria gonorrhoeae: a comparative analysis of three monoclonal antibody serotyping panels.

Sixteen hundred and thirty seven isolates of Neisseria gonorrhoeae isolated over a two year period were serotyped using three panels of monoclonal antibodies. The isolates comprised 687 serogroup WI strains and 950 serogroup WII/III strains. The antibodies used in the panels were those developed by Pharmacia (Ph) and Genetic Systems (GS). The GS antibodies were used as two separate panels; the American (GS-A) panel which designates serovars by a simple numerical nomenclature and the Swedish (GS-S) panel which designates serovars by a more detailed descriptive nomenclature. Using only a single panel the Ph panel gave the greatest discrimination yielding 42 serovars compared with 28 serovars with the GS-S panel and 23 serovars with the GS-A panel. Using two panels in combination, the GS-A/Ph panel combination gave the greatest discrimination with 81 serovar combinations while a combination of the GS-S and Ph panels yielded 77 serovar combinations. A compilation of antibodies from all three panels yielded 90 serovar combinations. As the combination of GS-A and Ph panels gave a greater degree of discrimination than the combination of the GS-S and Ph panels we advocate that first-stage serotyping should be performed with the more widely used GS-A panel while second-stage serotyping should be performed with the Ph panel. We propose that serovar combinations should be reported using a dual nomenclature e.g. IA-1/Arost, IB-1/Bropt, IB-1/Bropyt etc. The use of such a dual system would allow "core comparison" between all centres while maintaining a degree of flexibility regarding the extent of discrimination required.

Antibodies, Monoclonal↗
PubMed1991

Preliminary evaluation of "Clearview Chlamydia" for the rapid detection of chlamydial antigen in cervical secretions.

Clearview Chlamydia (Unipath) is a rapid monoclonal antibody based latex immunodiffusion test for detecting chlamydial antigen in endocervical specimens. The assay does not require specialised equipment or extensive training and takes less than 30 minutes from sample to results. The clinical performance of Clearview Chlamydia was evaluated with 478 paired endocervical swabs from patients attending a genitourinary medicine clinic. In the first part of the study, 221 non-randomised specimens were tested by cell culture (1st swab) and Clearview (2nd swab) whereas in the second part of the study 257 randomised swabs were examined by Clearview, cell culture and immunofluorescence. The overall prevalence of chlamydial infection was 8.8% and the sensitivity, specificity, positive and negative predictive values for Clearview were 85.7%, 99.1%, 90% and 98.6%. The test requires further evaluation to establish its role in the management and control of chlamydial infection.

Antigens, Bacterial↗
PubMed1991

Patterns of homosexually acquired gonococcal serovars in Edinburgh 1986-90.

AIM: The aim of this study was to observe the changes in gonococcal serovar pattern in homosexual men over a 5 year period. METHODS: All men who presented to the Genitourinary Medicine clinic at Edinburgh Royal Infirmary between 1986 and 1990 with homosexually acquired gonococcal infection were included in the study. Gonococcal isolates were serotyped and the temporal change in isolated serovars noted. RESULTS: Over the 5 year period 32 different serovars were associated with 175 homosexually acquired infections. There was a dynamic temporal change in the dominant serovars with a continual influx of new strains some of which become established in the community but most of which appeared only transiently. Rapid variation in incidence over time was observed for certain serovars while others remained at more constant levels. There was a marked association between certain serovars (Ae/Av; Back/Bropyt; Bacejk/Brpyut; Bacejk/Brpyust; Baejk/Brpyut) and homosexually acquired infection. CONCLUSIONS: Possible determinants for the patterns observed are discussed but the underlying mechanism is probably multifactorial.

Gonorrhea↗
PubMed1991

An analysis of false positive reactions occurring with the Captia Syph G EIA.

AIM: The Captia Syph G enzyme immuno assay (EAI) offers the potential for the rapid automated detection of syphilis antibodies. This study was designed to assess the role of other sexually transmitted diseases (STDs) in producing false positive reactions in the Captia Syph G EIA. The role of rheumatoid factor (RF) as a potential source of false positives was also analysed. METHODS: Patients who attended a genitourinary medicine (GUM) department and gave a false positive reaction with the EIA between 1988 and 1990 were compared with women undergoing antenatal testing and with the control clinic population (EIA negative) over the same time period. The incidence of sexually transmitted disease (STD) in the clinic population and the false positive reactors was measured in relation to gonorrhoea, chlamydia, genital warts, candidiasis, "other conditions not requiring treatment" and "other conditions requiring treatment." Male: female sex ratios were also compared. Ninety two RF positive sera were analysed with the EIA. RESULTS: The rate of false positive reactions did not differ with respect to the diagnosis within the GUM clinic population. The antenatal group of women, however, had a lower incidence of false positive reactions than the GUM clinic group. No RF positive sera were positive on Captia Syph G EIA testing. CONCLUSIONS: There is no cross reaction between Captia Syph G EIA and any specific STD or with RF positive sera. The lower incidence of false positive reactions in antenatal women is unexplained but may be related to physiological changes associated with pregnancy.

False Positive Reactions↗
PubMed1990

Gonococcal infection within Scotland: antigenic heterogeneity and antibiotic susceptibility of infecting strains.

Two panels of monoclonal antibody reagents were used to serotype all strains of Neisseria gonorrhoeae isolated from four separate geographical areas serving two million of the five million Scottish population. Serotype 1B isolates accounted for 60% of the 869 strains examined and were more prevalent than 1A isolates in each geographical area. A total of 11 1A serovars and 47 1B serovars were recognised. Only two of the 11 1A serovars (Aedgkih/Arost and Aedih/Arst) were found in every centre but these accounted for over 90% of the 1A isolates. Although there was a total of 47 different 1B serovars over 80% of the isolates were accounted for by the ten most commonly encountered serovars. There were, however, marked geographical differences within both major and minor serovars. There was a highly significant difference (P less than 0.001) between protein 1A and 1B serovars with respect to their susceptibility to penicillin. Within each protein 1 type there were also differences in antibiotic susceptibility. Penicillinase-producing N. gonorrhoeae (PPNG) were found in all centres and accounted for 24 (2.8%) of the 869 isolates. The majority of the PPNG (71%) were serotype 1A and with one exception were serovar Aedih/Arst. PPNG strains accounted for 37% (16) of the 43 Aedih/Arst isolates. Epidemiological, diagnostic and therapeutic implications arising from the distinct geographical differences in the pool of circulating gonococci are discussed.

Antibodies, Monoclonal↗