Deborah L. Couldwell

Failure of moxifloxacin treatment in Mycoplasma genitalium infections due to macrolide and fluoroquinolone resistance.

Increasing azithromycin treatment failure in sexually transmitted Mycoplasma genitalium infection, is linked to macrolide resistance and second-line treatment relies on the fluoroquinolone, moxifloxacin. We recently detected fluoroquinolone and macrolide resistance-associated mutations in 15% and 43%, respectively, of 143 initial M. genitalium PCR-positive specimens. For a subset of 33 Western Sydney Sexual Health Centre patients, clinical information and results of sequence analysis of M. genitalium macrolide and fluoroquinolone target genes – the 23S rRNA gene, and parC and gyrA, respectively – were used to examine whether mutations were associated with treatment failure. Macrolide resistance-associated mutations correlated with microbiological (p = 0.013) and clinical (p = 0.024) treatment failure, and fluoroquinolone resistance-associated mutations with microbiological moxifloxacin treatment failure (p = 0.005). We describe the first reported cases of clinical and microbiological moxifloxacin treatment failure. Failure of first- and second-line antibiotic treatment of M. genitalium infection is occurring and likely to increase with current treatment strategies.

Fluoroquinolone and Macrolide Resistance-Associated Mutations in Mycoplasma genitalium

ABSTRACT Mycoplasma genitalium is a significant sexually transmitted pathogen, causing up to 25% of cases of nongonococcal urethritis in men, and it is strongly associated with cervicitis and pelvic inflammatory disease in women. Currently, the usual first-line treatment is the macrolide antibiotic azithromycin, but an increasing incidence of treatment failure over the last 5 years suggests the emergence of antibiotic resistance. The mutations responsible for macrolide resistance have been found in the 23S rRNA gene in numerous M. genitalium populations. A second-line antibiotic, the fluoroquinolone moxifloxacin, was thought to be a reliable alternative when azithromycin began to fail, but recent studies have identified mutations that may confer fluoroquinolone resistance in the genes parC and gyrA. The aim of this study was to determine the prevalence of antibiotic resistance in M. genitalium in Sydney, Australia, by detecting relevant mutations in the 23S rRNA gene, parC, and gyrA. M. genitalium-positive DNA extracts of specimens, collected from patients attending sexual health clinics in Sydney, were tested by PCR amplification and DNA sequence alignment. The 186 specimens tested included 143 initial patient specimens and 43 second, or subsequent, specimens from 24 patients. We identified known macrolide resistance-associated mutations in the 23S rRNA gene in 43% of the initial patient samples and mutations potentially associated with fluoroquinolone resistance in parC or gyrA sequences in 15% of the initial patient samples. These findings support anecdotal clinical reports of azithromycin and moxifloxacin treatment failures in Sydney. Our results indicate that further surveillance is needed, and testing and treatment protocols for M. genitalium infections may need to be reviewed.

Simultaneous Identification of 14 Genital Microorganisms in Urine by Use of a Multiplex PCR-Based Reverse Line Blot Assay

ABSTRACT The aim of this study was to develop and evaluate a sensitive method for the simultaneous identification of 14 urogenital potential pathogens. A multiplex PCR-based reverse line blot (mPCR/RLB) assay was developed to detect 14 urogenital pathogens or putative pathogens, namely Trichomonas vaginalis, Streptococcus pneumoniae, Neisseria gonorrhoeae, Chlamydia trachomatis, Ureaplasma parvum, U. urealyticum, Gardnerella vaginalis, Haemophilus influenzae, herpes simplex virus type 1 (HSV1) and HSV2, N. meningitidis, Mycoplasma hominis, M. genitalium, and adenovirus, using two species-specific primer pairs and probes for each. The method was validated using a reference strain or a well-characterized clinical isolate of each target organism and was found to be both sensitive and specific. The limits of detection for the mPCR/RLB assay varied among the 14 target organisms from 4.2 × 10−1 to 7.0 × 10−11 ng/μl of genomic DNA. There were no cross-reactions among any of the probes. This method was used to test 529 first-voided urine specimens from male patients with and without urethritis attending two Sydney sexual health clinics. One or more target species were detected in 193 (36%) subjects. Of 233 positive results, overall 216 (93%) were concordant between mPCR/RLB and a comparator method (culture and/or species-specific PCR), 9 were positive only by mPCR/RLB, and 8 were positive only by the comparator method. The mPCR/RLB method was an accurate, convenient, and inexpensive method for the detection of multiple potential pathogens in first-voided urine specimens from men.

Multi-Centre Evaluation of the Determine HIV Combo Assay when Used for Point of Care Testing in a High Risk Clinic-Based Population

Background Determine HIV Combo (DHC) is the first point of care assay designed to increase sensitivity in early infection by detecting both HIV antibody and antigen. We conducted a large multi-centre evaluation of DHC performance in Sydney sexual health clinics. Methods We compared DHC performance (overall, by test component and in early infection) with conventional laboratory HIV serology (fourth generation screening immunoassay, supplementary HIV antibody, p24 antigen and Western blot tests) when testing gay and bisexual men attending four clinic sites. Early infection was defined as either acute or recent HIV infection acquired within the last six months. Results Of 3,190 evaluation specimens, 39 were confirmed as HIV-positive (12 with early infection) and 3,133 were HIV-negative by reference testing. DHC sensitivity was 87.2% overall and 94.4% and 0% for the antibody and antigen components, respectively. Sensitivity in early infection was 66.7% (all DHC antibody reactive) and the DHC antigen component detected none of nine HIV p24 antigen positive specimens. Median HIV RNA was higher in false negative than true positive cases (238,025 vs. 37,591 copies/ml; p = 0.022). Specificity overall was 99.4% with the antigen component contributing to 33% of false positives. Conclusions The DHC antibody component detected two thirds of those with early infection, while the DHC antigen component did not enhance performance during point of care HIV testing in a high risk clinic-based population.

Ureaplasma urealyticum is significantly associated with non-gonococcal urethritis in heterosexual Sydney men.

We investigated the prevalence of various genital organisms in 268 men with (cases) and 237 men without (controls) urethral symptoms/signs (urethral discharge, dysuria and/or urethral irritation) from two sexual health clinics in Sydney between April 2006 and November 2007. The presence of urethral symptoms/signs was defined as non-gonococcal urethritis (NGU) for this study. Specific aims were to investigate the role of Ureaplasma urealyticum in NGU and the prevalence of Mycoplasma genitalium in our population. Multiplex polymerase chain reaction-based reverse line blot (mPCR/RLB) assay was performed to detect 14 recognized or putative genital pathogens, including Chlamydia trachomatis, M. genitalium, U. urealyticum and U. parvum. U. urealyticum was associated with NGU in men without another urethral pathogen (odds ratio [OR] 2.0, 95% confidence interval [CI] 1.1–3.8; P = 0.04); this association remained after controlling for potential confounding by age and history of unprotected vaginal sex in the last four weeks (OR 2.0, 95% CI: 1.1–3.9; P = 0.03). C. trachomatis (OR 7.5, P < 0.001) and M. genitalium (OR 5.5, P = 0.027) were significantly associated with NGU. The prevalence of M. genitalium was low (4.5% cases, 0.8% controls). U. urealyticum is independently associated with NGU in men without other recognized urethral pathogens. Further research should investigate the role of U. urealyticum subtypes among heterosexual men with NGU.

Barriers to HIV testing and characteristics associated with never testing among gay and bisexual men attending sexual health clinics in Sydney

HIV diagnoses among gay and bisexual men have increased over the past decade in Australia. HIV point‐of‐care testing (POCT) was introduced in Australia in 2011 as a strategy to increase HIV testing by making the testing process more convenient. We surveyed gay and bisexual men undergoing POCT to assess barriers to HIV testing and characteristics associated with not having previously tested for HIV (never testing).

The prevalence of urogenital micro-organisms detected by a multiplex PCR―reverse line blot assay in women attending three sexual health clinics in Sydney, Australia

This study used a previously described multiplex PCR-based reverse line blot (mPCR/RLB) assay to assess the prevalence and distribution of 14 urogenital pathogens or putative pathogens, namely Neisseria gonorrhoeae, Chlamydia trachomatis, Mycoplasma genitalium, Mycoplasma hominis, Trichomonas vaginalis, Gardnerella vaginalis, Ureaplasma parvum, Ureaplasma urealyticum, Neisseria meningitidis, Streptococcus pneumoniae, Haemophilus influenzae, herpes simplex virus types 1 and 2, and human adenovirus. First-voided urine specimens and endocervical and self-collected vaginal swabs from each of 216 women attending three sexual health clinics in Sydney, Australia, were tested and the results were compared with those of reference methods for each organism. One hundred and sixty-eight women (77.7 %) had at least one and 105 (48.6 %) had more than one target organism, most commonly G. vaginalis and Ureaplasma spp. The prevalence of each of the four known sexually transmissible pathogens was <5 %. Of the 216 women, 111 (51.4 %) reported at least one symptom consistent with genital or urethral infection, including discharge, pain or discomfort. Only G. vaginalis was detected more frequently in women with symptoms (P = 0.05). The specificity of the mPCR/RLB assay compared with that of the reference methods for each organism and for all specimen types was 100 %. The mean sensitivities of the mPCR/RLB assay compared with those of the reference methods for self-collected vaginal swabs, cervical swabs and first-voided urine specimens for all organisms were 99.3, 98.1 and 84.6 %, respectively; however, these differences were not significant. There were no differences in sensitivities between specimen types for C. trachomatis, N. gonorrhoeae, T. vaginalis and H. influenzae, although all were found infrequently. Overall, the mPCR/RLB platform was found to be an accurate testing platform in a sexual health clinic setting.

Mycoplasma genitalium infection: current treatment options, therapeutic failure, and resistance-associated mutations

Mycoplasma genitalium is an important cause of non-gonococcal urethritis, cervicitis, and related upper genital tract infections. The efficacy of doxycycline, used extensively to treat non-gonococcal urethritis in the past, is relatively poor for M. genitalium infection; azithromycin has been the preferred treatment for several years. Research on the efficacy of azithromycin has primarily focused on the 1 g single-dose regimen, but some studies have also evaluated higher doses and longer courses, particularly the extended 1.5 g regimen. This extended regimen is thought to be more efficacious than the 1 g single-dose regimen, although the regimens have not been directly compared in clinical trials. Azithromycin treatment failure was first reported in Australia and has subsequently been documented in several continents. Recent reports indicate an upward trend in the prevalence of macrolide-resistant M. genitalium infections (transmitted resistance), and cases of induced resistance following azithromycin therapy have also been documented. Emergence of antimicrobial-resistant M. genitalium, driven by suboptimal macrolide dosage, now threatens the continued provision of effective and convenient treatments. Advances in techniques to detect resistance mutations in DNA extracts have facilitated correlation of clinical outcomes with genotypic resistance. A strong and consistent association exists between presence of 23S rRNA gene mutations and azithromycin treatment failure. Fluoroquinolones such as moxifloxacin, gatifloxacin, and sitafloxacin remain highly active against most macrolide-resistant M. genitalium. However, the first clinical cases of moxifloxacin treatment failure, due to bacteria with coexistent macrolide-associated and fluoroquinolone-associated resistance mutations, were recently published by Australian investigators. Pristinamycin and solithromycin may be of clinical benefit for such multidrug-resistant infections. Further clinical studies are required to determine the optimal therapeutic dosing schedules for both agents to effect clinical cure and minimize the risk of emergent antimicrobial resistance. Continual inappropriate M. genitalium treatments will likely lead to untreatable infections in the future.

Rapid HIV Testing Is Highly Acceptable and Preferred among High-Risk Gay And Bisexual Men after Implementation in Sydney Sexual Health Clinics

Background Rapid HIV testing (RHT) is well established in many countries, but it is new in Australia. We assessed the acceptability of RHT and its associations among gay, bisexual and other men who have sex with men (GBM) after implementation of RHT in Sydney sexual health clinics. Methods GBM were invited to complete an acceptability questionnaire before and after provision of the result of finger-prick blood RHT, comparing their experience of RHT with conventional HIV testing (CHT) involving venipuncture. Logistic regression was used to assess associations between patient characteristics and the preference for RHT over CHT next time they tested for HIV. Results Of 1061 GBM who received non-reactive RHT results, 59% found RHT less stressful than CHT and 34% reported no difference, and 61% found RHT more comfortable than CHT and 26% reported no difference. Nearly all men were satisfied with RHT result delivery (99%) and the RHT process overall (99%). Most men (79%) preferred RHT for their next HIV test and this preference was stronger in men who were aged 35-44 years (adjusted odds ratio [AOR] 2.49, p<0.01), reported they would test more often if RHT was available (AOR 1.66, p=0.01), found returning for results annoying (AOR 1.67, p=0.01), and found RHT less stressful (AOR 2.37, p<0.01) and more comfortable (AOR 1.62, p=0.02) than CHT. Men concerned about the reliability of RHT were less than half as likely to prefer RHT for their next HIV test (AOR 0.44, p<0.01). Conclusions Most GBM preferred RHT to CHT next time and this preference was associated with finding RHT more convenient, more comfortable and less stressful than CHT. These findings suggest that in a clinic setting RHT should be considered to improve the patient experience and may potentially increase uptake and frequency of HIV testing.

What proportion of sexually transmissible infections and HIV are diagnosed in New South Wales’ public sexual health services compared with other services?

BACKGROUND In New South Wales (NSW), publicly funded sexual health services (PFSHSs) target the populations at greatest risk for important sexually transmissible infections (STIs) and so may make a large contribution to the diagnosis of notifiable STIs. We aimed to determine the proportions of STIs diagnosed in PFSHSs and notified to the NSW Ministry of Health in 2009, and describe geographical variations. METHODS The number of notifiable STIs (infectious syphilis, gonorrhoea, HIV and chlamydia) diagnosed in 2009 was obtained for each Area Health Service (AHS) and each PFSHS. The proportion of diagnoses made by PFSHSs was calculated at the state and AHS level according to five geographical regions: inner and outer metropolitan, regional, rural and remote. RESULTS The overall proportions of diagnoses made by NSW PFSHSs were syphilis, 25%; gonorrhoea, 25%; HIV, 21%; and chlamydia, 14%. Within each zone, the proportions of these STIs were (respectively): (i) inner metropolitan: 32%, 26%, 21% and 13%; (ii) outer metropolitan: 41%, 24%, 43% and 9%; (iii) regional: 62%, 15%, 23% and 10%; (iv) rural: 8%, 29%, <5% and 20%; and (v) remote: <5%, 43%, <5% and 29%. There was considerable variation in proportions of STIs between and within AHSs (<5-100%). CONCLUSIONS NSW PFSHSs contribute a large proportion of diagnoses for syphilis, gonorrhoea and HIV, but less so for chlamydia. Across AHSs and zones, there was considerable variation in the proportions. These data support the role of PFSHS in identifying and managing important STIs in high-risk populations.