PubMed Health⌕ Search

Biomedical subjects

A Moyes

Publications and source records attributed to A Moyes.

At least 19 recordsLinked to original sources
PubMed2005

Evaluation of the serodia Treponema pallidum particle agglutination, the Murex Syphilis ICE and the Enzywell TP tests for serodiagnosis of syphilis.

We evaluated the Treponema pallidum haemagglutination assay (TPHA), a treponemal test, with three other treponemal tests, the Serodia T. pallidum particle agglutination assay, the Murex Syphilis ICE IgG + IgM enzyme immunoassay (EIA) and the Enzywell TP IgG + M EIA (a new rapid EIA) for use in conjunction with the rapid plasma reagin test (RPR), a non-treponemal test, for serodiagnosis of syphilis. In all, 124 serum samples were found reactive with RPR and/or TPHA after testing by the routine laboratory protocol. Twenty-three (18.5%) of them were positive only by RPR test and were evaluated as biologically false-positive, 16 were positive only by the TPHA and 84 by both the RPR and TPHA tests; one sample was non-specific (heterophile reaction) in the TPHA. Agreements of the TPHA with the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP tests were 96.7%, 100% and 99.1%, respectively. We conclude that each one of the tests, the Serodia TPPA, the Murex Syphilis ICE and the Enzywell TP, is an appropriate substitute for screening for serodiagnosis of syphilis.

Antibodies, Bacterial↗
PubMed2000

Increased ciprofloxacin resistance in gonococci isolated in Scotland.

A review of the susceptibility of Neisseria gonorrhoeae isolated from 4415 episodes of infection in Scotland between 1991 and 1999 showed that the proportion of isolates with lowered susceptibility (ciprofloxacin minimum inhibitory concentration [MIC] > or = 0.05 mg/L) increased from 0.5% in 1991 to 5% in 1999 (p<0.001), whereas the proportion of isolates with clinical resistance (ciprofloxacin MIC > or = 1 mg/L) was significantly higher in 1999 than the average for the preceding 4 years (2.2% vs 0.9%; p=0.02). Ciprofloxacin is a recommended treatment for gonococcal infection in the UK but if resistance continues to increase at the present rate it might not be suitable as a first-line treatment of gonorrhoea for much longer.

Anti-Infective Agents↗
PubMed2000

The sac-4 gene of Neisseria gonorrhoeae and co-existing chlamydial infection.

BACKGROUND/OBJECTIVES: Recently, the sac-4 gene in Neisseria gonorrhoeae was postulated to increase the risk of developing mixed gonococcal and chlamydial infection. The aims of this study were to determine the frequency of the sac-4 gene in a larger sample of isolates of different serovars and to assess the prevalence of sac-4 in gonococcal isolates from patients with and without coexisting chlamydial infection. METHODS: Isolates from 259 episodes of gonorrhoea were tested by a PCR assay for the sac-4 gene. The presence of co-existing chlamydial infection was determined from both laboratory and GUM clinical records. RESULTS: The overall prevalence of sac-4 was 57.5% (149/259). The prevalence was not the same in all serovars and ranged from 34.9% in serovar 1B2 to 100% in serovar 1B18. Exact logistic regression analysis indicated significant differences in sac-4 prevalence in isolates of different serovars. The prevalence of sac-4 was 69.5% (41/59) in gonococcal isolates from patients with co-existing chlamydial infection compared with 57.9% (62/107) for those without chlamydial infection. Exact logistic regression analysis showed that the slightly increased sac-4 prevalence among chlamydia positive patients (p = 0.2) virtually disappeared when serovar status was taken into account (p > 0.9). CONCLUSION: The sac-4 gene of the gonococcus does not increase the risk for mixed chlamydial infection.

Chlamydia Infections↗
PubMed2000

Rectal gonorrhoea in homosexual men: source of infection.

The objective of this retrospective study was to determine the possible source of infection in homosexual men with rectal gonorrhoea: the probable source of rectal gonorrhoea was identified in 46/155 cases. Although the urethra was the site of infection in 33 (72%) of these contacts, only pharyngeal gonorrhoea was identified in 9 (20%) men. In 25/26 cases, there was concordance in the auxo/serotypes of Neisseria gonorrhoeae between contacts with urethral gonorrhoea and the index men with rectal gonorrhoea. Eleven out of 12 pharyngeal isolates were of the same auxo/serotype as the index cases. This study supports the hypothesis that rectal gonorrhoea in homosexual men can be acquired from the oropharynx. Because infection at this site is an independent risk factor for acquisition of HIV, screening for rectal and pharyngeal gonorrhoea should be offered to men who have sex with men, even when there is no history of unprotected receptive anal intercourse.

Adolescent↗
PubMed2000

Enzywell recombinant enzyme immunoassay for the serological diagnosis of syphilis.

The aim of this study was to evaluate Enzywell TP, a new rapid enzyme immunoassay (EIA) that uses 2 recombinant Treponema pallidum antigens for the serological diagnosis of syphilis. Specificity was evaluated by screening 1055 unselected bloods requesting serological tests for syphilis in parallel with Enzywell TP and the Syphilis ICE EIA which is our standard screening test for syphilis. Sensitivity was evaluated using a panel of 159 known treponemal sera representing various stages of syphilis and 5 treponemal sera detected on screening. The specificity of Enzywell TP on initial and repeat testing (99.6% and 99.7% respectively) was similar to that of the Syphilis ICE test (99.8% and 99.9% respectively). The sensitivity of Enzywell TP (100%) was similar to that of Syphilis ICE (99.4%): both tests were significantly more sensitive (P=0.01) than the fluorescent antibody absorbed test (94.5%) but not the T. pallidum particle agglutination (TPPA) assay (99.4%). Both Enzywell TP and Syphilis ICE were positive with sera from 16 known HIV-infected patients who had been treated for syphilis many years previously (mean 9.4 years) confirming the value of these tests in excluding previous syphilis in HIV-infected individuals. We conclude that the Enzywell recombinant EIA is simple, rapid, highly sensitive and specific, and is a welcome addition to the range of currently available diagnostic tests for syphilis.

Antibodies, Bacterial↗
PubMed1999

Subtyping of high-level plasmid-mediated tetracycline resistant Neisseria gonorrhoeae isolated in Scotland between 1992 and 1998.

Tetracycline resistant Neisseria gonorrhoeae (TRNG) contain a 25.2 MDa TetM plasmid encoding a 68 KDa cytoplasmic protein which confers high-level tetracycline resistance. The aim of this study was to subtype all TRNG isolated in Scotland between 1992 and 1998. Subtyping was performed by a polymerase chain reaction (PCR) assay which characterizes the TetM plasmid as either the Dutch variant (443 base pair product) or the American variant (777 base pair product). Of the 78 TRNG isolates, 35 were the American variant and 43 were the Dutch variant. TRNG were distributed amongst 30 serovar/auxotype classes, the most common being 1A6/NR (11.5%), 1A6/P (14.1%) and 1B4/NR (14.1%). The country where infection was acquired was known for 36 of the 46 TRNG strains isolated between 1996 and 1998. All infections acquired in Asia and South America were the Dutch variant whereas all infections acquired in Africa were the American variant. A penicillinase plasmid was present in 66% (23/35) of the American variant TRNG compared with 51% (22/43) of the Dutch variant: the 3.2 MDa penicillinase plasmid was found in 87% of the American variant TRNG whereas the 4.4 MDa penicillinase plasmid was found in 68% of the Dutch variant TRNG. We conclude that subtyping of TRNG by PCR is a useful tool in studying the epidemiology of gonococcal infection due to plasmid-mediated resistant isolates.

Bacterial Typing Techniques↗
PubMed1999

Epidemiology and treatment outcome of infection with antibiotic resistant strains of Neisseria gonorrhoeae in Scotland.

Antibiotic resistance in Neisseria gonorrhoeae occurs worldwide and may limit the efficacy of treatment. This study reports the epidemiology and treatment outcome for 125 episodes of infection with antibiotic resistant gonococci diagnosed in Scotland in 1996. Infections with penicillinase producing N. gonorrhoeae (PPNG) and/or high level plasmid mediated tetracycline resistant N. gonorrhoeae (TRNG) and isolates showing reduced susceptibility to ciprofloxacin were more likely to belong to an unusual serovar and have been acquired abroad by heterosexual intercourse than isolates showing chromosomal resistance to penicillin or tetracycline, which were more likely to belong to a common serovar and to have been acquired in the United Kingdom by homosexual intercourse. Among the 88 episodes of infection whose outcome was known initial treatment with an antibiotic to which the isolate was resistant failed in nine out of 16 infections and in three out of the 72 infections treated with an antibiotic to which the organism was sensitive. In the case of high level plasmid mediated resistance, treatment with an inappropriate antibiotic always resulted in failure. Continuous monitoring of treatment outcome is essential to guide clinicians in prescribing the most appropriate antibiotic for individual patients.

Adolescent↗
PubMed1998

Novel recombinant-antigen enzyme immunoassay for serological diagnosis of syphilis.

Enzyme immunoassay (EIA) is an ideal method for screening large numbers of patients for syphilis. We evaluated a novel immune-capture EIA (ICE Syphilis; Murex Diagnostics) that uses three recombinant Treponema pallidum antigens (TpN15, TpN17, and TpN47) and compared the results with those obtained by the native T. pallidum antigen EIA (Captia SelectSyph-G; Centocor) that we currently use for the serodiagnosis of syphilis. Specificity was evaluated by screening 1,184 unselected serum specimens in parallel by the ICE Syphilis and SelectSyph-G assays, while sensitivity was tested with a panel of 101 serum specimens containing antitreponemal antibodies (treated and untreated) from patients with various stages of infection. The specificity of the ICE Syphilis EIA (99.8%) on screening was significantly higher (P < 0.02) than that of the SelectSyph-G EIA (99.2%). The sensitivity of the ICE Syphilis EIA was significantly higher (P < 0.01) than that of the SelectSyph-G EIA on both initial (99 versus 91.4%) and repeat (100 versus 92.4%) testing. The ICE Syphilis EIA was also significantly more sensitive (P < 0.01) than the fluorescent treponemal antibody-abs (92.4%) but not the T. pallidum hemagglutination assay (97.1%). Sera containing antitreponemal antibodies gave a much higher antibody index (absorbance of test serum/kit cutoff) by the ICE Syphilis EIA than by the SelectSyph-G EIA. This combined with the overall high sensitivity makes the ICE Syphilis EIA an ideal test for excluding or detecting treponemal infection in human immunodeficiency virus (HIV)-infected patients. The ICE Syphilis EIA was positive with sera from all 15 HIV-infected patients in the study, whereas sera from 3 HIV-infected patients were negative by the SelectSyph-G EIA. We conclude that the high sensitivity and specificity of the ICE Syphilis EIA and its suitability for automation make it an ideal screening test.

Antigens, Bacterial↗
PubMed1998

PCR testing of genital and urine specimens compared with culture for the diagnosis of chlamydial infection in men and women.

Our aim was to determine the number of chlamydial infections detected by Cobas Amplicor CT/NG multiplex polymerase chain reaction (PCR) testing of genital and first-voided urine (FVU) specimens compared with routine culture. Two hundred and eighty-six female and 276 male patients attending the Genito-Urinary Medicine (GUM) Unit at Edinburgh Royal Infirmary were included in the study. Case notes were analysed retrospectively to determine how many infected patients would not have been treated had diagnosis relied on routine culture. Polymerase chain reaction on FVU from women had a sensitivity, specificity, positive and negative predictive value of 91%, 100%, 100% and 99.1%: corresponding values for genital PCR and culture were 96%, 100%, 100%, 99.6% and 65%, 100%, 100%, 96.7% respectively. PCR on FVU from men had a sensitivity, specificity, positive and negative predictive value of 96%, 99.1%, 92.6% and 99.5%: corresponding values for genital PCR and culture were 89%, 99.5%, 95.8%, 98.6% and 48%, 100%, 100%, 94.3% respectively. In both men and women genital PCR and urine PCR were significantly more sensitive than culture. PCR almost doubled the number of patients detected by culture (49 vs 27). Of the 22 cases detected only by PCR 8 would not have received treatment on the basis of clinic treatment policy.

Chi-Square Distribution↗
PubMed1998

A new recombinant antigen latex agglutination test (Syphilis Fast) for the rapid serological diagnosis of syphilis.

We report an assessment of Syphilis Fast, a new latex test that uses a pool of 3 recombinant Treponema pallidum antigens (TpN15, TpN17, and TpN47) for the serodiagnosis of syphilis. Specificity was evaluated by screening 1518 unselected blood specimens in parallel with Syphilis Fast, the Captia SelectSyph-G EIA and the Venereal Disease Research Laboratory (VDRL) cardiolipin antigen test while sensitivity was tested using a panel of 99 treponemal sera (treated and untreated) representing various stages of infection and 15 treponemal sera detected on screening. The specificity of Syphilis Fast on initial testing (99.8%) was significantly higher (P<0.02) than that of Captia SelectSyph-G (99.2%) and the VDRL (99.1%): the specificity of Syphilis Fast remained significantly higher (P<0.02) after repeat testing (respective values 99.9%, 99.5% and 99.4%). There was no difference in the sensitivity of Syphilis Fast and Captia SelectSyph-G on initial (93% vs 92.1%) or repeat (95.6% vs 94.7%) testing: both were significantly more sensitive (P<0.001) than the VDRL (46.5% on initial and 43.9% on repeat testing). The sensitivities of the Treponema pallidum haemagglutination test (TPHA) and FTA-abs were 98.2% and 95.6% respectively. Negative reactions in Syphilis Fast and SelectSyph-G were associated with treated infections and correlated with low TPHA titres (< or = 80). We conclude that Syphilis Fast is a highly specific, simple and fast screening test with a sensitivity comparable to native antigen treponemal tests and that it merits consideration as a front-line screening test.

Antibodies, Bacterial↗
PubMed1997

Failure of Neisseria gonorrhoeae to grow in the ATB NH susceptibility test system.

The ATB NH system designed for antibiotic susceptibility testing of Neisseria gonorrhoeae, Neisseria meningitidis and Haemophilus influenzae was evaluated using 94 clinical isolates of gonococci representing a wide variety of serovar/auxotype strains. Using the manufacturer's automated system 55% of the clinical isolates failed to grow, compared with a 33% failure rate for manual processing and visual reading. Growth failure was significantly higher with 1A isolates (73% automated and 69% manual) than with 1B isolates (49% automated and 25% manual). The higher failure rate of 1A isolates correlated with multiple auxotrophy. The inability of the ATB NH system to support the growth of common serovar/auxotypes makes the ATB NH system unsuitable for antibiotic susceptibility testing of N. gonorrhoeae.

Humans↗
PubMed1997

Non-cultural detection of rectal and pharyngeal gonorrhoea by the Gen-Probe PACE 2 assay.

OBJECTIVE: To assess the sensitivity and specificity of the Gen-Probe PACE 2 assay, which uses a chemiluminescent labelled single-stranded DNA probe to detect gonococcal ribosomal RNA (rRNA), for the non-cultural detection of rectal and pharyngeal gonorrhoea in homosexual men. SUBJECTS: 161 homosexual men attending the Department of Genitourinary Medicine, Edinburgh Royal Infirmary during the latter half of 1995 and the first quarter of 1996. METHODS: Duplicate rectal and pharyngeal swabs were collected for culture on modified New York City (MNYC) medium and detection of gonococcal nucleic acid by the Gen-Probe assay. Repeatedly reactive Gen-Probe specimens from culture negative patients were also tested by the Gen-Probe competition assay (PCA). RESULTS: Of the 161 patients, 23 (14.3%) gave a positive culture at one or both sites (rectum 10, throat 8, rectum and throat 5) compared with 28 (16.7%) who gave a positive Gen-Probe result at one or both sites (rectum 9, throat 11, rectum and throat 8). After resolution of discrepant results by PCA the sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of Gen-Probe was 94.1%, 100%, 100% and 99.3% for rectal specimens while the corresponding values for pharyngeal specimens were 86.4%, 100%, 100%, and 97.9%. The sensitivity and NPV of rectal culture were 88.2% and 98.6% while the corresponding values for pharyngeal culture were 59% and 93.9%. Gen-Probe was significantly more sensitive than throat culture (p < 0.05) but not rectal culture (p > 0.2). The average Relative Light Units (RLU) value for the cut-off was 386 (range 351-450) while the average for a positive result was 20306 (range 403-110104): this was, however, significantly higher (p = 0.019) in rectal specimens 31325 (range 1705-110104) than in throat specimens 10447 (range 403-15633). CONCLUSIONS: Gen-Probe PACE 2 assay is a sensitive and specific method for the detection of rectal and pharyngeal gonorrhoea. As the Gen-Probe assay may detect nucleic acid from non viable gonococci the clinical significance of a probe positive culture negative specimen from a patient without culture evidence of gonorrhoea at another site is uncertain and requires further consideration. Nevertheless a positive result does indicate exposure to infection and could be important in ensuring appropriate partner notification action. If non-cultural methods are used to screen for gonococcal infection cultures should be obtained from patients with positive results in order that the antibiotic susceptibility and molecular epidemiology of the gonococcal population can be monitored.

Bacteriological Techniques↗
PubMed1997

Azithromycin and erythromycin resistant Neisseria gonorrhoeae following treatment with azithromycin.

A pre-treatment and a 3-week post-treatment isolate of Neisseria gonorrhoeae from a 13-year-old boy treated with azithromycin in a single 1 g oral dose were characterized microbiologically. Both isolates were of the same serovar/auxotype (1B6/non-requiring) and had similar antibiograms apart from erythromycin and azithromycin: the pre- and post-treatment MICs (minimum inhibitory concentrations) were: 1 mg/L and 32 mg/L to erythromycin and 0.125 mg/L and 3 mg/L to azithromycin. The finding that both isolates were 1B6/NR, had similar antibiograms (other than azithromycin and erythromycin), and no other 1B6/NR isolates were resistant to erythromycin supports the view that macrolide resistance developed following treatment. A high overall level of azithromycin susceptibility was confirmed by testing 67 clinical isolates: MIC90 0.5 mg/L (range 0.023-0.75 mg/L). We conclude that the long half-life of azithromycin which is beneficial in treating chlamydial infection may result in increased selective pressure for resistance in gonococci. This report also highlights the importance of antibiotic susceptibility surveillance of gonococci and stresses the need for appropriate treatment of gonococcal infection, particularly when it is prescribed outwith departments of genitourinary medicine.

Adolescent↗
PubMed1996

An evaluation of pre-poured selective media for the isolation of Neisseria gonorrhoeae.

Fourteen commercial media supplied as pre-poured plates were compared with an 'in-house' selective medium for their ability to support the growth of 105 gonococcal isolates (representing a wide variety of serovars encountered in natural infection), 25 meningococcal and 20 Neisseria lactamica isolates, and to inhibit the growth of 71 isolates of non-pathogenic neisseriae and miscellaneous organisms. Only two of the pre-poured plate media and the in-house selective medium yielded growth of duplicate cultures of all 105 gonococcal isolates after incubation for 24 h: one other medium provided growth of all the isolates after incubation for 48 h. The ability of the various media to suppress the growth of the 71 isolates of non-pathogenic neisseriae and miscellaneous organisms ranged from 97.2 to 71.8% of isolates inhibited. Of the four media that enabled growth of all the gonococcal strains, inhibition was 94.4% for the in-house medium, 85.9% and 80.3% for the two media on which all gonococci grew after 24 h and 71.8% for the medium on which all of the gonococci grew after 48 h. Failure of growth of gonococci was associated with: serogroup IA isolates (p<0.001), AHU auxotype (p<0.001) and the presence of vancomycin rather than lincomycin in the selective medium (p < 0.02). The use of 10% blood and a highly nutritious medium based on the original New York City (NYC) or modified New York City (MNYC) formulation were also important in supporting growth of gonococci. One of the main problems in lack of selectivity was a failure to inhibit the growth of yeasts. As effective inhibition of yeasts was obtained with other media containing the same concentration of amphotericin, failure may be due to batch variation of supplement, media preparation, or reduced shelf life of the media. None of the commercially available pre-poured media performed as well as the in-house medium despite the fact that some of the media were prepared to a very similar formula.

Culture Media↗
PubMed1995

Serovar specific immunity to Neisseria gonorrhoeae: does it exist?

OBJECTIVE: To determine whether the host immune response to gonorrhoea provides limited serovar specific protection from reinfection. SUBJECTS: 508 episodes of gonorrhoea diagnosed at a city centre genitourinary medicine clinic including 22 patients with multiple infections over a 4 year period. METHODS: Patients with recurrent gonococcal infection were analysed with respect to the initial and subsequent serovars isolated. RESULTS: No significant difference was seen in the prevalence of serovars isolated following a repeat infection compared with those without repeat infections. The site of the initial infection did not appear to influence the subsequent serovar isolated. CONCLUSION: We found no evidence of serovar specific immunity in our population. It remains possible that populations with a higher prevalence of gonorrhoea and more frequent infections may have a quantitatively greater immune response.

Adolescent↗
PubMed1995

Storage and repeated recovery of Neisseria gonorrhoeae using cryovials.

One hundred gonococcal isolates, representing eight protein IA serovars and 14 protein IB serovars, were stored at -70 degrees C using the Pro-Lab Microbank cryovial storage system. At monthly intervals a bead from each cryovial was removed and cultured on modified New York City medium. The overall recovery rate was 98.6% (2365/2400), the 35 failures representing 13 separate isolates. There was a small but significant decrease in recovery in the last 12 months of the trial (97.8%) compared with the first 12 months (99.8%), which may have been due to a sampling problem rather than a temporal phenomenon. Failures were significantly associated with minor serovars, suggesting that the transmissibility/viability of minor serovars may be lower than that of common serovars and could be a significant factor in the epidemiology of gonococcal infection. We conclude that Pro-Lab Microbank cryovials provide a highly effective and convenient system for storage of Neisseria gonorrhoeae, particularly when multiple retrieval is required, and the system offers many advantages over conventional lyophilisation.

Cryopreservation↗
PubMed1995

Gonococcal serovar patterns in Glasgow: 1990-1992.

Using monoclonal antibodies directed against protein 1 (major outer membrane protein) in the cell wall of Neisseria gonorrhoeae it is possible to serotype the gonococcus into different sub-groups. This study was designed to analyse the distribution of such serovars in Glasgow, Scotland, and report associations between serovars and clinical features of infection. N. gonorrhoeae isolated from all patients with a diagnosis of gonorrhoea attending genitourinary medicine clinics in Glasgow were serotyped between January 1990 and December 1992. The results were then correlated with sexual orientation of patients, penicillin sensitivity, site of infection, location of acquisition of infection and presence of symptoms. Six hundred and four episodes of gonococcal infection were analysed and an association between certain serovars with sexual orientation, penicillin sensitivity and asymptomatic infection was found. No association between serovar type and locality of acquisition of infection was apparent. Although there was a decreasing trend in the incidence of gonorrhoea overall, infections in homosexual men increased over the three-year study period. The associations between serovars and other features of gonococcal infection are discussed. The observed increase in homosexually-acquired infection has implications with regard to the spread of human immunodeficiency virus infection in this area, and suggests that attempts to promote safer sex in this group are failing.

Adolescent↗