Julie van Schalkwyk

Characterization of the vaginal microbiota of healthy Canadian women through the menstrual cycle

BackgroundThe vaginal microbial community plays a vital role in maintaining women’s health. Understanding the precise bacterial composition is challenging because of the diverse and difficult-to-culture nature of many bacterial constituents, necessitating culture-independent methodology. During a natural menstrual cycle, physiological changes could have an impact on bacterial growth, colonization, and community structure. The objective of this study was to assess the stability of the vaginal microbiome of healthy Canadian women throughout a menstrual cycle by using cpn 60-based microbiota analysis. Vaginal swabs from 27 naturally cycling reproductive-age women were collected weekly through a single menstrual cycle. Polymerase chain reaction (PCR) was performed to amplify the universal target region of the cpn 60 gene and generate amplicons representative of the microbial community. Amplicons were pyrosequenced, assembled into operational taxonomic units, and analyzed. Samples were also assayed for total 16S rRNA gene content and Gardnerella vaginalis by quantitative PCR and screened for the presence of Mollicutes by using family and genus-specific PCR.ResultsOverall, the vaginal microbiome of most women remained relatively stable throughout the menstrual cycle, with little variation in diversity and only modest fluctuations in species richness. Microbiomes between women were more different than were those collected consecutively from individual women. Clustering of microbial profiles revealed the expected groupings dominated by Lactobacillus crispatus, Lactobacillus iners, and Lactobacillus jensenii. Interestingly, two additional clusters were dominated by either Bifidobacterium breve or a heterogeneous mixture of nonlactobacilli. Direct G. vaginalis quantification correlated strongly with its pyrosequencing-read abundance, and Mollicutes, including Mycoplasma hominis, Ureaplasma parvum, and Ureaplasma urealyticum, were detected in most samples.ConclusionsOur cpn 60-based investigation of the vaginal microbiome demonstrated that in healthy women most vaginal microbiomes remained stable through their menstrual cycle. Of interest in these findings was the presence of Bifidobacteriales beyond just Gardnerella species. Bifidobacteriales are frequently underrepresented in 16S rRNA gene-based studies, and their detection by cpn 60-based investigation suggests that their significance in the vaginal community may be underappreciated.

Cytomegalovirus Infection in Pregnancy

OBJECTIVES To review the principles of prenatal diagnosis of congenital cytomegalovirus (CMV) infection and to describe the outcomes of the affected pregnancies. OUTCOMES Effective management of fetal infection following primary and secondary maternal CMV infection during pregnancy. Neonatal signs include intrauterine growth restriction (IUGR), microcephaly, hepatosplenomegaly, petechiae, jaundice, chorioretinitis, thrombocytopenia and anemia, and long-term sequelae consist of sensorineural hearing loss, mental retardation, delay of psychomotor development, and visual impairment. These guidelines provide a framework for diagnosis and management of suspected CMV infections. EVIDENCE Medline was searched for articles published in English from 1966 to 2009, using appropriate controlled vocabulary (congenital CMV infection) and key words (intrauterine growth restriction, microcephaly). Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated into the guideline. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. RECOMMENDATIONS The quality of evidence reported in this document has been assessed using the evaluation of evidence criteria in the Report of the Canadian Task Force on Preventive Health Care (Table 1). 1. Diagnosis of primary maternal cytomegalovirus (CMV) infection in pregnancy should be based on de-novo appearance of virus-specific IgG in the serum of a pregnant woman who was previously seronegative, or on detection of specific IgM antibody associated with low IgG avidity. (II-2A) 2. In case of primary maternal infection, parents should be informed about a 30% to 40% risk for intrauterine transmission and fetal infection, and a risk of 20% to 25% for development of sequelae postnatally if the fetus is infected. (II-2A) 3. The prenatal diagnosis of fetal CMV infection should be based on amniocentesis, which should be done at least 7 weeks after presumed time of maternal infection and after 21 weeks of gestation. This interval is important because it takes 5 to 7 weeks following fetal infection and subsequent replication of the virus in the kidney for a detectable quantity of the virus to be secreted to the amniotic fluid. (II-2A) 4. The diagnosis of secondary infection should be based on a significant rise of IgG antibody titre with or without the presence of IgM and high IgG avidity. In cases of proven secondary infection, amniocentesis may be considered, but the risk-benefit ratio is different because of the low transmission rate. (III-C) 5. Following a diagnosis of fetal CMV infection, serial ultrasound examinations should be performed every 2 to 4 weeks to detect sonographic abnormalities, which may aid in determining the prognosis of the fetus, although it is important to be aware that the absence of sonographic findings does not guarantee a normal outcome. (II-2B) 6. Quantitative determination of CMV DNA in the amniotic fluid may assist in predicting the fetal outcome. (II-3B) 7. Routine screening of pregnant women for CMV by serology testing is currently not recommended. (III-B) 8. Serologic testing for CMV may be considered for women who develop influenza-like illness during pregnancy or following detection of sonographic findings suggestive of CMV infection. (III-B) 9. Seronegative health care and child care workers may be offered serologic monitoring during pregnancy. Monitoring may also be considered for seronegative pregnant women who have a young child in day care. (III-B).

Antibiotic Prophylaxis in Gynaecologic Procedures

Abstract Objective To review the evidence and provide recommendations on antibiotic prophylaxis for gynaecologic procedures. Outcomes Outcomes evaluated include need and effectiveness of antibiotics to prevent infections in gynaecologic procedures. Evidence Medline and The Cochrane Library were searched for articles published between January 1978 and January 2011 on the topic of antibiotic prophylaxis in gynaecologic procedures. Results were restricted to systematic reviews, randomized control trials/ controlled clinical trials, and observational studies. Searches were updated on a regular basis and incorporated in the guideline to June 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values The quality of evidence obtained was rated using the criteria described in the Report of the Canadian Task Force on Preventative Health Care (Table 1). Benefits, harms, and costs Guideline implementation should result in a reduction of cost and related harm of administering antibiotics when not required and a reduction of infection and related morbidities when antibiotics have demonstrated a proven benefit. Recommendations 1. All women undergoing an abdominal or vaginal hysterectomy should receive antibiotic prophylaxis. (I-A) 2. All women undergoing laparoscopic hysterectomy or laparoscopically assisted vaginal hysterectomy should receive prophylactic antibiotics. (III-B) 3. The choice of antibiotic for hysterectomy should be a single dose of a first-generation cephalosporin. If patients are allergic to cephalosporin, then clindamycin, erythromycin, or metronidazole should be used. (I-A) 4. Prophylactic antibiotics should be administered 15 to 60 minutes prior to skin incision. No additional doses are recommended. (I-A) 5. If an open abdominal procedure is lengthy (e.g., > 3 hours), or if the estimated blood loss is > 1500 mL, an additional dose of the prophylactic antibiotic may be given 3 to 4 hours after the initial dose. (III-C) 6. Antibiotic prophylaxis is not recommended for laparoscopic procedures that involve no direct access from the abdominal cavity to the uterine cavity or vagina. (l-E) 7. All women undergoing surgery for pelvic organ prolapse and/or stress urinary incontinence should receive a single dose of firstgeneration cephalosporin. (III-B) 8. Antibiotic prophylaxis is not recommended for hysteroscopic surgery. (II-2D) 9. All women undergoing an induced (therapeutic) surgical abortion should receive prophylactic antibiotics to reduce the risk of postabortal infection. (I-A) 10. Prophylactic antibiotics are not suggested to reduce infectious morbidity following surgery for a missed or incomplete abortion. (I-E) 11. Antibiotic prophylaxis is not recommended for insertion of an intrauterine device. (I-E) However, health care professionals could consider screening for sexually transmitted infections in high-risk populations. (III-C) 12. There is insufficient evidence to support the use of antibiotic prophylaxis for an endometrial biopsy. (III-L) 13. The best method to prevent infection after hysterosalpingography is unknown. Women with dilated tubes found at the time of hysterosalpingography are at highest risk, and prophylactic antibiotics (e.g., doxycycline) should be given. (II-3B) 14. Antibiotic prophylaxis is not recommended for urodynamic studies in women at low risk, unless the incidence of urinary tract infection post-urodynamics is > 10%. (1-E) 15. In patients with morbid obesity (BMI > 35 kg/m2), doubling the antibiotic dose may be considered. (III-B) 16 Administration of antibiotics solely to prevent endocarditis is not recommended for patients who undergo a genitourinary procedure. (III-E)

A Study of the Vaginal Microbiome in Healthy Canadian Women Utilizing cpn60-Based Molecular Profiling Reveals Distinct Gardnerella Subgroup Community State Types.

The vaginal microbiota is important in women’s reproductive and overall health. However, the relationships between the structure, function and dynamics of this complex microbial community and health outcomes remain elusive. The objective of this study was to determine the phylogenetic range and abundance of prokaryotes in the vaginal microbiota of healthy, non-pregnant, ethnically diverse, reproductive-aged Canadian women. Socio-demographic, behavioural and clinical data were collected and vaginal swabs were analyzed from 310 women. Detailed profiles of their vaginal microbiomes were generated by pyrosequencing of the chaperonin-60 universal target. Six community state types (CST) were delineated by hierarchical clustering, including three Lactobacillus-dominated CST (L. crispatus, L. iners, L. jensenii), two Gardnerella-dominated (subgroups A and C) and an “intermediate” CST which included a small number of women with microbiomes dominated by seven other species or with no dominant species but minority populations of Streptococcus, Staphylococcus, Peptoniphilus, E. coli and various Proteobacteria in co-dominant communities. The striking correspondence between Nugent score and deep sequencing CST continues to reinforce the basic premise provided by the simpler Gram stain method, while additional analyses reveal detailed cpn60-based phylogeny and estimated abundance in microbial communities from vaginal samples. Ethnicity was the only demographic or clinical characteristic predicting CST, with differences in Asian and White women (p = 0.05). In conclusion, this study confirms previous work describing four cpn60-based subgroups of Gardnerella, revealing previously undescribed CST. The data describe the range of bacterial communities seen in Canadian women presenting with no specific vaginal health concerns, and provides an important baseline for future investigations of clinically important cohorts.

Antibiotic prophylaxis in obstetric procedures.

Abstract Objective To review the evidence and provide recommendations on antibiotic prophylaxis for obstetrical procedures. Outcomes Outcomes evaluated include need and effectiveness of antibiotics to prevent infections in obstetrical procedures. Evidence Published literature was retrieved through searches of Medline and The Cochrane Library on the topic of antibiotic prophylaxis in obstetrical procedures. Results were restricted to systematic reviews, randomized controlled trials/controlled clinical trials, and observational studies. Searches were updated on a regular basis and articles published from January 1978 to June 2009 were incorporated in the guideline. Current guidelines published by the American College of Obstetrics and Gynecology were also incorporated. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. Values The evidence obtained was reviewed and evaluated by the Infectious Diseases Committee of the Society of Obstetricians and Gynaecologists of Canada under the leadership of the principal authors, and recommendations were made according to guidelines developed by the Canadian Task Force on Preventive Health Care (Table 1). Benefits, Harms, and Costs Implementation of this guideline should reduce the cost and harm resulting from the administration of antibiotics when they are not required and the harm resulting from failure to administer antibiotics when they would be beneficial. Summary Statements 1. Available evidence does not support the use of prophylactic antibiotics to reduce infectious morbidity following operative vaginal delivery. (II-1) 2. There is insufficient evidence to argue for or against the use of prophylactic antibiotics to reduce infectious morbidity for manual removal of the placenta. (III) 3. There is insufficient evidence to argue for or against the use of prophylactic antibiotics at the time of postpartum dilatation and curettage for retained products of conception. (III) 4. Available evidence does not support the use of prophylactic antibiotics to reduce infectious morbidity following elective or emergency cerclage. (II-3) Recommendations 1. All women undergoing elective or emergency Caesarean section should receive antibiotic prophylaxis. (I-A) 2. The choice of antibiotic for Caesarean section should be a single dose of a first-generation cephalosporin. If the patient has a penicillin allergy, clindamycin or erythromycin can be used. (I-A) 3. The timing of prophylactic antibiotics for Caesarean section should be 15 to 60minutes prior to skin incision. No additional doses are recommended. (I-A) 4. If an open abdominal procedure is lengthy (>3hours) or estimated blood loss is greater than 1500mL, an additional dose of the prophylactic antibiotic may be given 3 to 4hours after the initial dose. (III-L) 5. Prophylactic antibiotics may be considered for the reduction of infectious morbidity associated with repair of third and fourth degree perineal injury. (I-B) 6. In patients with morbid obesity (BMI>35), doubling the antibiotic dose may be considered. (III-B) 7. Antibiotics should not be administered solely to prevent endocarditis for patients who undergo an obstetrical procedure of any kind. (III-E

Guidelines for the Management of Herpes Simplex Virus in Pregnancy

OBJECTIVE To provide recommendations for the management of genital herpes infection in women who want to get pregnant or are pregnant and for the management of genital herpes in pregnancy and strategies to prevent transmission to the infant. OUTCOMES More effective management of complications of genital herpes in pregnancy and prevention of transmission of genital herpes from mother to infant. EVIDENCE Medline was searched for articles published in French or English related to genital herpes and pregnancy. Additional articles were identified through the references of these articles. All study types and recommendation reports were reviewed. VALUES Recommendations were made according to the guidelines developed by the Canadian Task Force on Preventive Health Care.

Screening and Management of Bacterial Vaginosis in Pregnancy

OBJECTIVE To review the evidence and provide recommendations on screening for and management of bacterial vaginosis in pregnancy. OPTIONS The clinical practice options considered in formulating the guideline. OUTCOMES Outcomes evaluated include antibiotic treatment efficacy and cure rates, and the influence of the treatment of bacterial vaginosis on the rates of adverse pregnancy outcomes such as preterm labour and delivery and preterm premature rupture of membranes. EVIDENCE Medline, EMBASE, CINAHL, and Cochrane databases were searched for articles, published in English before the end of June 2007 on the topic of bacterial vaginosis in pregnancy. VALUES The evidence obtained was rated using the criteria developed by the Canadian Task Force on Preventive Health Care. BENEFITS, HARMS, AND COSTS Guideline implementation will assist the practitioner in developing an approach to the diagnosis and treatment of bacterial vaginosis in pregnant women. Patients will benefit from appropriate management of this condition. VALIDATION These guidelines have been prepared by the Infectious Diseases Committee of the SOGC, and approved by the Executive and Council of the SOGC. SPONSORS The Society of Obstetricians and Gynaecologists of Canada.

Principles of human teratology: drug, chemical, and infectious exposure.

OBJECTIVE To provide a teratology update for prescription and non-prescription drugs and infections during pregnancy. OPTIONS Limited to teratology principles and possible common exposures during pregnancy. EVIDENCE A search of Medline and textbooks was conducted for information published to June 2006 on teratology exposure risks. This document represents an abstraction of the information. BENEFITS, HARMS, AND COSTS This consensus provides practitioners with a summary of information regarding teratology risks for drug, chemical, and infection exposures during pregnancy.

HIV Screening in Pregnancy

OBJECTIVE The purpose of this guideline is to provide recommendations to obstetric health care providers and to minimize practice variations for HIV screening, while taking provincial and territorial recommendations into account. OUTCOMES The risk of transmission of HIV from mother to fetus is significant if the mother is not treated. The primary outcome of screening for and treating HIV in pregnancy is a marked decrease in the rate of vertical transmission of HIV from mother to fetus. Secondary outcomes include confirmation of HIV infection in the woman, which allows optimization of her health and long-term management. EVIDENCE The Cochrane Library and Medline were searched for English-language articles published related to HIV screening and pregnancy. Additional articles were identified through the references of these articles. All study types were reviewed.

Management of Group B Streptococcal Bacteriuria in Pregnancy

OBJECTIVE To provide information regarding the management of group B streptococcal (GBS) bacteriuria to midwives, nurses, and physicians who are providing obstetrical care. OUTCOMES The outcomes considered were neonatal GBS disease, preterm birth, pyelonephritis, chorioamnionitis, and recurrence of GBS colonization. EVIDENCE Medline, PubMed, and the Cochrane database were searched for articles published in English to December 2010 on the topic of GBS bacteriuria in pregnancy. Bacteriuria is defined in this clinical practice guideline as the presence of bacteria in urine, regardless of the number of colony-forming units per mL (CFU/mL). Low colony counts refer to < 100 000 CFU/mL, and high (significant) colony counts refer to ≥ 100 000 CFU/mL. Results were restricted to systematic reviews, randomized controlled trials, and relevant observational studies. Searches were updated on a regular basis and incorporated in the guideline to February 2011. Grey (unpublished) literature was identified through searching the websites of health technology assessment and health technology assessment-related agencies, clinical practice guideline collections, clinical trial registries, and national and international medical specialty societies. VALUES Recommendations were quantified using the evaluation of evidence guidelines developed by the Canadian Task Force on Preventive Health Care (Table). BENEFITS, HARMS, AND COSTS The recommendations in this guideline are designed to help clinicians identify pregnancies in which it is appropriate to treat GBS bacteriuria to optimize maternal and perinatal outcomes, to reduce the occurrences of antibiotic anaphylaxis, and to prevent increases in antibiotic resistance to GBS and non-GBS pathogens. No cost-benefit analysis is provided. RECOMMENDATIONS 1. Treatment of any bacteriuria with colony counts ≥ 100 000 CFU/mL in pregnancy is an accepted and recommended strategy and includes treatment with appropriate antibiotics. (II-2A) 2. Women with documented group B streptococcal bacteriuria (regardless of level of colony-forming units per mL) in the current pregnancy should be treated at the time of labour or rupture of membranes with appropriate intravenous antibiotics for the prevention of early-onset neonatal group B streptococcal disease. (II-2A) 3. Asymptomatic women with urinary group B streptococcal colony counts < 100 000 CFU/mL in pregnancy should not be treated with antibiotics for the prevention of adverse maternal and perinatal outcomes such as pyelonephritis, chorioamnionitis, or preterm birth. (II-2E) 4. Women with documented group B streptococcal bacteriuria should not be re-screened by genital tract culture or urinary culture in the third trimester, as they are presumed to be group B streptococcal colonized. (II-2D).