Elena Shipitsyna

Differences in human papillomavirus type distribution in high‐grade cervical intraepithelial neoplasia and invasive cervical cancer in Europe

Knowledge of differences in human papillomavirus (HPV)‐type prevalence between high‐grade cervical intraepithelial neoplasia (HG‐CIN) and invasive cervical cancer (ICC) is crucial for understanding the natural history of HPV‐infected cervical lesions and the potential impact of HPV vaccination on cervical cancer prevention. More than 6,000 women diagnosed with HG‐CIN or ICC from 17 European countries were enrolled in two parallel cross‐sectional studies (108288/108290). Centralised histopathology review and standardised HPV‐DNA typing were applied to formalin‐fixed paraffin‐embedded cervical specimens dated 2001–2008. The pooled prevalence of individual HPV types was estimated using meta‐analytic methods. A total of 3,103 women were diagnosed with HG‐CIN and a total of 3,162 with ICC (median ages: 34 and 49 years, respectively), of which 98.5 and 91.8% were HPV‐positive, respectively. The most common HPV types in women with HG‐CIN were HPV16/33/31 (59.9/10.5/9.0%) and in ICC were HPV16/18/45 (63.3/15.2/5.3%). In squamous cell carcinomas, HPV16/18/33 were most frequent (66.2/10.8/5.3%), and in adenocarcinomas, HPV16/18/45 (54.2/40.4/8.3%). The prevalence of HPV16/18/45 was 1.1/3.5/2.5 times higher in ICC than in HG‐CIN. The difference in age at diagnosis between CIN3 and squamous cervical cancer for HPV18 (9 years) was significantly less compared to HPV31/33/‘other’ (23/20/17 years), and for HPV45 (1 year) than HPV16/31/33/‘other’ (15/23/20/17 years). In Europe, HPV16 predominates in both HG‐CIN and ICC, whereas HPV18/45 are associated with a low median age of ICC. HPV18/45 are more frequent in ICC than HG‐CIN and associated with a high median age of HG‐CIN, with a narrow age interval between HG‐CIN and ICC detection. These findings support the need for primary prevention of HPV16/18/45‐related cervical lesions.

Composition of the Vaginal Microbiota in Women of Reproductive Age – Sensitive and Specific Molecular Diagnosis of Bacterial Vaginosis Is Possible?

Background and Objective Bacterial vaginosis (BV) is the most common vaginal disorder, characterized by depletion of the normal lactobacillus-dominant microbiota and overgrowth of commensal anaerobic bacteria. This study aimed to investigate the composition of the vaginal microbiota in women of reproductive age (healthy women and women with BV), with the view of developing molecular criteria for BV diagnosis. Materials and Methods Vaginal samples from 163 women (79 control, 73 BV and 11 intermediate (Lactobacillary grade II flora) cases) were analyzed using 454 pyrosequencing of the hypervariable regions V3–V4 of the 16S rRNA gene and 16 quantitative bacterial species/genus-specific real-time PCR assays. Sensitivities and specificities of potential BV markers were computed using the Amsel criteria as reference standard for BV. The use of quantitative thresholds for prediction of BV, determined for both relative abundance measured with 454 pyrosequencing and bacterial load measured with qPCR, was evaluated. Results Relative to the healthy women, the BV patients had in their vaginal microbiota significantly higher prevalence, loads and relative abundances of the majority of BV associated bacteria. However, only Gardnerella vaginalis, Atopobium vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 detected at or above optimal thresholds were highly predictable for BV, with the best diagnostic accuracy shown for A. vaginae. The depletion of Lactobacillus species combined with the presence of either G. vaginalis or A. vaginae at diagnostic levels was a highly accurate BV predictor. Conclusions Quantitative determination of the presence of G. vaginalis, A. vaginae, Eggerthella, Prevotella, BVAB2 and Megasphaera type 1 as well as the depletion of Lactobacillus was highly accurate for BV diagnosis. Measurements of abundance of normal and BV microbiota relative to total bacteria in vaginal fluid may provide more accurate BV diagnosis, and be used for test-of-cure, rather than qualitative detection or absolute counts of BV related microorganisms.

Whole-genome sequences of Chlamydia trachomatis directly from clinical samples without culture

The use of whole-genome sequencing as a tool for the study of infectious bacteria is of growing clinical interest. Chlamydia trachomatis is responsible for sexually transmitted infections and the blinding disease trachoma, which affect hundreds of millions of people worldwide. Recombination is widespread within the genome of C. trachomatis, thus whole-genome sequencing is necessary to understand the evolution, diversity, and epidemiology of this pathogen. Culture of C. trachomatis has, until now, been a prerequisite to obtain DNA for whole-genome sequencing; however, as C. trachomatis is an obligate intracellular pathogen, this procedure is technically demanding and time consuming. Discarded clinical samples represent a large resource for sequencing the genomes of pathogens, yet clinical swabs frequently contain very low levels of C. trachomatis DNA and large amounts of contaminating microbial and human DNA. To determine whether it is possible to obtain whole-genome sequences from bacteria without the need for culture, we have devised an approach that combines immunomagnetic separation (IMS) for targeted bacterial enrichment with multiple displacement amplification (MDA) for whole-genome amplification. Using IMS-MDA in conjunction with high-throughput multiplexed Illumina sequencing, we have produced the first whole bacterial genome sequences direct from clinical samples. We also show that this method can be used to generate genome data from nonviable archived samples. This method will prove a useful tool in answering questions relating to the biology of many difficult-to-culture or fastidious bacteria of clinical concern.

First evaluation of six nucleic acid amplification tests widely used in the diagnosis of Chlamydia trachomatis in Russia

Background  In Russia, nationally developed nucleic acid amplification tests (NAATs), which have never been validated to international commercially available NAATs, are mainly used in the diagnosis of Chlamydia trachomatis infection.

Recommended antimicrobial treatment of uncomplicated gonorrhoea in 2009 in 11 East European countries: implementation of a Neisseria gonorrhoeae antimicrobial susceptibility programme in this region is crucial.

Background Antimicrobial resistance (AMR) in Neisseria gonorrhoeae (gonococcus) is a major problem worldwide. Quality-assured and quality-controlled AMR surveillance data on gonococci globally are crucial for public health purposes. In East European countries, knowledge regarding gonococcal AMR and its prevalence is limited. Objectives To ascertain the recommendations for antimicrobial treatment of uncomplicated gonorrhoea in 11 East European countries, valuable information for introducing an international gonococcal AMR surveillance programme. Methods A questionnaire was used to collect information regarding the types, doses and manufacturers of the antimicrobials recommended for gonorrhoea treatment in all countries. Results Ceftriaxone (250–1000 mg, intramuscularly (IM)×1) was reported as a first-line antimicrobial in all countries (n=11). Many of the second-line and alternative treatments seemed suboptimal for empirical treatment. Regionally manufactured antimicrobials were predominantly used and easily available, and some may be of suboptimal quality. This generates effective prerequisites for emergence, and rapid spread of gonococcal AMR and gonorrhoea. Conclusion Ceftriaxone was first-line antimicrobial in all the 11 East European countries, which is an appropriate choice also in a global perspective. However, the adherence, especially among private physicians, to these public sector recommendations is questionable. Implementation of national and international gonococcal AMR surveillance in this region is crucial; to provide evidence-based data for regular and timely updating of treatment guidelines, to identify emerging resistance, and to assist in the prevention, control and containment of gonococcal AMR and gonorrhoea.

Guidelines for the Laboratory Diagnosis of Mycoplasma genitalium Infections in East European Countries

The present guidelines aim to provide comprehensive information regarding laboratory diagnosis of Mycoplasma genitalium infections in East European countries. These guidelines are intended primarily for laboratory professionals testing specimens from patients at sexual health care clinics, but may also be useful for community-based screening programmes. Diagnosis of M. genitalium infection is performed exclusively using nucleic acid amplification tests (NAATs), owing to the poor and slow growth of the bacterium in culture. Because no internationally validated and approved commercial NAAT for M. genitalium detection is presently available, it is necessary that laboratories performing M. genitalium diagnostics not only carefully evaluate and validate their in-house PCRs before using them routinely, but also use comprehensive internal controls and take part in external quality assessment programmes. The guidelines were elaborated as a consensus document of the Eastern European Sexual and Reproductive Health (EE SRH) Network, and comprise one element of a series of guidelines aimed at optimizing, standardizing, and providing guidance on quality laboratory testing for reproductive tract infections.

Pooling Samples: the Key to Sensitive, Specific and Cost-effective Genetic Diagnosis of Chlamydia trachomatis in Low-Resource Countries

The aims of this study were to compare the performance characteristics and cost-effectiveness of pooling endocervical samples for screening and diagnosis of Chlamydia trachomatis, and to investigate the prevalence of C. trachomatis infection in women in Leningrad Oblast, Russia. A total of 1500 endocervical samples were tested individually and when pooled in groups of 5 and 10 samples, respectively. A previously evaluated in-house diagnostic polymerase chain reaction (PCR) assay was utilized. The sensitivity and specificity of the PCR were not affected by either pooling strategy. The estimated prevalence of genital C. trachomatis infection was 6.6%, 6.1% and 6.0% based on individually tested samples, and pools of 5 and 10, respectively. For diagnosis of individual samples, the pooling strategies resulted in cost savings of 53.3% (5 samples per pool) and 44.0% (10 samples per pool). Pooling samples for PCR detection of C. trachomatis is an accurate and cost-saving approach for diagnosis and large-scale prevalence studies in St Petersburg, Russia.

Human papillomavirus prevalence and type-distribution in cervical glandular neoplasias: results from a European multinational epidemiological study

Cervical glandular neoplasias (CGN) present a challenge for cervical cancer prevention due to their complex histopathology and difficulties in detecting preinvasive stages with current screening practices. Reports of human papillomavirus (HPV) prevalence and type‐distribution in CGN vary, providing uncertain evidence to support prophylactic vaccination and HPV screening. This study [108288/108290] assessed HPV prevalence and type‐distribution in women diagnosed with cervical adenocarcinoma in situ (AIS, N = 49), adenosquamous carcinoma (ASC, N = 104), and various adenocarcinoma subtypes (ADC, N = 461) from 17 European countries, using centralised pathology review and sensitive HPV testing. The highest HPV‐positivity rates were observed in AIS (93.9%), ASC (85.6%), and usual‐type ADC (90.4%), with much lower rates in rarer ADC subtypes (clear‐cell: 27.6%; serous: 30.4%; endometrioid: 12.9%; gastric‐type: 0%). The most common HPV types were restricted to HPV16/18/45, accounting for 98.3% of all HPV‐positive ADC. There were variations in HPV prevalence and ADC type‐distribution by country. Age at diagnosis differed by ADC subtype, with usual‐type diagnosed in younger women (median: 43 years) compared to rarer subtypes (medians between 57 and 66 years). Moreover, HPV‐positive ADC cases were younger than HPV‐negative ADC. The six years difference in median age for women with AIS compared to those with usual‐type ADC suggests that cytological screening for AIS may be suboptimal. Since the great majority of CGN are HPV16/18/45‐positive, the incorporation of prophylactic vaccination and HPV testing in cervical cancer screening are important prevention strategies. Our results suggest that special attention should be given to certain rarer ADC subtypes as most appear to be unrelated to HPV.

Comprehensive global genome dynamics of Chlamydia trachomatis show ancient diversification followed by contemporary mixing and recent lineage expansion

Chlamydia trachomatis is the worlds most prevalent bacterial sexually transmitted infection and leading infectious cause of blindness, yet it is one of the least understood human pathogens, in part due to the difficulties of in vitro culturing and the lack of available tools for genetic manipulation. Genome sequencing has reinvigorated this field, shedding light on the contemporary history of this pathogen. Here, we analyze 563 full genomes, 455 of which are novel, to show that the history of the species comprises two phases, and conclude that the currently circulating lineages are the result of evolution in different genomic ecotypes. Temporal analysis indicates these lineages have recently expanded in the space of thousands of years, rather than the millions of years as previously thought, a finding that dramatically changes our understanding of this pathogens history. Finally, at a time when almost every pathogen is becoming increasingly resistant to antimicrobials, we show that there is no evidence of circulating genomic resistance in C. trachomatis.

First evaluation of polymerase chain reaction assays used for diagnosis of Mycoplasma genitalium in Russia

Background  Diagnosis of Mycoplasma genitalium is entirely based on nucleic acid amplification tests (NAATs). In Russia, several M. genitalium polymerase chain reaction (PCR) assays have been developed; however, any evaluation of their performance has never been performed.