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Acinetobacter Species Associated with Spontaneous Preterm Birth and Histological Chorioamnionitis
Abstract
Aim: Preterm birth is a complex and unresolved public health problem across the globe. Infection is a factor for which a causal link has been established with preterm birth. A better understanding of its aetiology is required to improve obstetric and neonatal care. The case highlights the limitations of current obstetric hospital microbiology tests, and contributes to the knowledge of bacterial pathogens in the female genital tract associated with preterm birth. Case Presentation: A woman presented with no signs of infection and spontaneously delivered preterm at 34 weeks gestation. Culture-based microbiological results from blood samples and swabs of mother and child were negative. Postpartum histopathology of the placenta demonstrated chorioamnionitis, and vasculitis of the umbilical cord. Cultivation-independent PCR analyses showed a massive Acinetobacter spp. infection. Conclusion: Cultivation-independent PCR analyses may detect potentially pathogenic species when standard culture-based techniques are negative. The frequency of Acinetobacter spp. infections during pregnancy and in neonatal units manifests the need to develop appropriate diagnostic methods that can become standard practice in hospitals and clinics.
... Potential effects of colonization by Atopobium, Corynebacterium, Gardnerella, and Megasphaera and have been discussed. The presence of Acinetobacter has been associated with PTB and neonatal infections in American women (He et al., 2013), spontaneous preterm and chorioamnionitis in an Australian Caucasian woman (Quinlivan et al., 2014), and vaginal infection in Indian women (Gopalan et al., 2017). Genital infections of Acinetobacter during pregnancy are associated with adverse outcomes in various racial backgrounds. ...
The genital microbiomes of women varies with racial background. Preterm birth and early-onset neonatal sepsis are two outcomes associated with genital infections during pregnancy. The rate of preterm birth in Aboriginal Australian mothers is high, as is the rate of early-onset sepsis in their infants. To date, no studies have been conducted to investigate genital microbiome taxa associated infection in this group of women. A prospective cohort study to characterize the vaginal and placental microbiomes of a group of these women from the Pilbara region was conducted at the Hedland Health Campus in Western Australia. Included in the study were gravidae Aboriginal (n = 23) and Non-aboriginal (n = 27) women in labor or for planned lower uterine segment Caesarean section. Employing sterile swabs, vaginal samples were obtained under sterile conditions immediately prior to vaginal delivery or planned Caesarean section; and placental samples were obtained under the same conditions during labor. Taxa present in the samples were identified by 16S rRNA amplicon sequencing (V4 region, 515F-806R). Taxon identity and abundance were established from Operational Taxonomic Unit (OTU) counts. Statistical analyses combining clinical metadata and sequencing results were employed to determine associations of taxa with racial background. The findings of this work served to enhance the current understanding of microbiota associated with health and disease in Aboriginal and Non-Aboriginal women. Differences were found between the vaginal and placental microbiomes of Aboriginal and Non-aboriginal women during pregnancy, as well as notable differences between the abundance of specific taxa in each racial group. The relative abundances of specific taxa were significantly different between participants with clinical signs of infection and those with healthy pregnancies. This work will contribute to understanding the causes of differences in rates of infection-driven preterm birth in various racial populations.
... Natural reservoirs of this bacterium outside hospital environment have not yet been identified, however, a few case reports of its association with complications in pregnant women instigated this study. In rare cases, A. baumannii has been reported to cause premature contraction and chorioamnionitis in pregnant women (Aivazova et al., 2010;Quinlivan et al., 2014). ...
... Our experience of epidemiologic changes in the etiology of PPROM means that a more complete diagnostic procedure must be followed, with wider analytic studies, adapting available diagnostic procedures to clinical needs. New culture-independent tools, including DNA amplification techniques have related several oral bacteria species to PPROM and chorioamnionitis and sometimes yield positive results even when vaginal and endocervical cultures are negative [12][13][14][15]. These new techniques can help to detect a possible unusual bacterial infection when vaginal and endocervical cultures are negative in cases of chorioamnionitis, preterm birth, or PPROM. ...
Introduction. Preterm premature rupture of membranes (PPROM) usually has a multifactorial etiology that is often unknown, although the most frequently reported cause is infection by group B Streptococcus. Therefore, the etiology of PPROM, although probably infectious, remains unknown in most cases. This case describes a PPROM caused by infection from oropharyngeal microbiota.
Case presentation. We report the case of a 26-yr-old pregnant woman. The gestational age was 32 weeks+5 days. Examinations in the emergency department revealed the release of clear amniotic fluid and a closed multiparous cervix with a length of 22 mm. Endocervical culture evidenced the growth of Staphylococcus aureus, serogroup B Neisseria meningitidis and Haemophilus influenzae.
Conclusion. Preventive antibiotic therapy should consider: opportunistic infections by normal genital microbiota, infections due to sexual activity, opportunist microorganisms derived from oral sex, and the hematogenous spread of oral bacteria.
... Recently, it has been proposed that the incongruent findings might be attributed to traditional culturing methods failing to detect some microbial species [11][12][13]. With the advent of culture-independent techniques such as broad-range PCR and fast sequencing to detect the presence of microbial taxa in the amniotic cavity, it is estimated the prevalence of microbes is higher than previously detected by culturebased methods [6]. ...
Aims: To determine if dental bacterial DNA are present in the amniotic cavity of healthy pregnant women undergoing an elective caesarean section at term utilising culture independent techniques. Methods: Pregnant Australian women undergoing an elective caesarean section were recruited. Women completed questionnaires addressing demographics, past and current pregnancies and medical history. One high vaginal swab and three amniotic cavity swabs (amniotic fluid, newborn axilla and placental) were collected under sterile conditions. Samples were analysed using culture-independent techniques to detect the presence of predefined pathogenic bacterial taxa of the oral microbiome. Taxa isolated from the amniotic cavity swabs were compared to those isolated from the vaginal swab. Results: DNA from taxa isolated from the amniotic cavity but not vagina included A. Conclusion: The DNA of many pathogenic oral bacteria can be identified in the amniotic cavity of healthy pregnant women at term when utilising culture-independent techniques. Given DNA is not always present in the vagina, the study findings fulfill one criterion necessary for oral haematogenous spread to the amniotic cavity.
... Employing HTS of the 16S rRNA gene and statistical analyses on DNA extracted from vaginal swabs, bacterial taxa can be identified in the vagina of women with a complicated pregnancy. Recent cases report that taxa belonging to the genera Acinetobacter, Bacteroides, and Hafnia, and the species Campylobacter curvus and Haemophilus parainfluenzae were potentially involved in preterm, very preterm and extremely preterm births [57][58][59]; Table 1 summarises data from these reports. Of note is that none of the taxa identified by 16S rRNA techniques, nor any other pathogens, including Group B Streptococcus, were found employing standard hospital cultures of vaginal swabs. ...
Understanding of the vaginal microbiome in health and disease is essential to screen, detect and manage complications in pregnancy. One of the major complications of pregnancy is preterm birth (PTB), which is the leading world-wide cause of death and disability in children under five years of age. The aetiology of PTB is multifactorial, a causal link has been established with infection. Despite the importance of understanding the vaginal microbiome in pregnancy in order to evaluate strategies to prevent and manage PTB, currently used culture based techniques provide limited information as not all pathogens are able to be cultured.
Implementation of culture-independent high-throughput techniques and bioinformatics tools are now advancing our understanding of the vaginal microbiome. New methods employing 16S rRNA and metagenomics analyses make possible a more comprehensive description of the bacteria of the human microbiome. Several studies on the vaginal microbiota of pregnant women have identified a large number of taxa. Studies also suggest reduced diversity of the microbiota in pregnancy compared to non-pregnant women, with a relative enrichment of the overall abundance of Lactobacillus species, and significant differences in the diversity of Lactobacillus spp. A number of advantages and disadvantages of these new techniques are briefly discussed.
The potential clinical importance of the new techniques is illustrated through recent reports where traditional culture-based techniques failed to identify pathogens in high risk complicated pregnancies whose presence subsequently was established using culture-independent, high-throughput analyses.
Introduction:
Some anecdotal reports suggest that maternal colonisation with Acinetobacter baumannii during pregnancy is associated with adverse maternal and neonatal effects, including preterm premature rupture of membrane (PPROM). The objective of this study was to compare the maternal and neonatal effects of A. baumannii colonisation in cases with PPROM and those with spontaneous onset of labour at term.
Methods:
The recruitment of participants' was carried out at Selayang Hospital, Selangor, Malaysia. Vaginal swabs were prospectively taken from 104 patients of PPROM and 111 with spontaneous onset of labour at term. Swabs were also taken from the axillae and ears of their babies. These swabs were cultured to isolate A. baumannii. Maternal and neonatal adverse outcomes were documented.
Results:
Sixteen mothers were A. baumannii positive, eight from each group respectively. None of the cases developed chorioamnionitis or sepsis. Those positive were four cases of PPROM and two babies of term labour. None of the babies developed sepsis.
Conclusions:
This study does not support the suggestion that A. baumannii colonisation during pregnancy is associated with adverse maternal and neonatal outcomes.
Objective. In a prospective study, we have recruited two groups of pregnant women (the first one with preterm labor activity; the second one with labor in term), trying to find a correlation between bacterial vaginosis (BV) and preterm birth activity. Other parameters influencing the presence of BV have been studied as well, such as educational level and history of previous preterm deliveries. Materials and Methods. Each group was composed of 75 women; recruitment stopped when the number was reached. Bacteriological data were retrospectively collected from the follow-up visits that pregnant women had performed at the regional hospital facility, where the study was performed. The diagnosis of BV was made according to Amsel criteria. Results. Our study showed a significant correlation between BV and preterm labor. BV seems to be an independent risk factor for preterm labor. In the study group, the prevalence of BV was 32%, whereas in the control group, the figure was 14.6% (
𝑃
=
0
.
0
1
). Conclusion. Highly risked groups for a preterm birth activity, such as pregnant women presenting BV and with a low educational level, have to be followed up and eventually treated cautiously in order to avoid early and late complications of preterm delivery.
Objective To determine perinatal and pregnancy outcomes of Acinetobacter baumannii infection using clinicopathologic material from pregnant women, neonates, and perinatal postmortem examinations with positive cultures.
Study Design This is a retrospective record review with placental and postmortem examination.
Results During a 5-year period, 40 positive cultures were found. Three pregnancies with positive cultures close in the peripartum period were all associated with adverse outcomes including spontaneous abortion, preterm labor, and one full-term birth with histological chorioamnionitis. Two positive cultures were found in preterm neonates in the neonatal intensive care unit. Two of three cases of perinatal death grew pure cultures from blood and/or fetal tissue with placental or fetal examination demonstrating evidence of infection/inflammation with fetal inflammatory response.
Conclusion This is the first case series report of A. baumannii-positive cultures in maternal, fetal, and neonatal specimen, with histopathologic evidence of infection. The results suggest a significant role of A. baumannii infection in adverse pregnancy and perinatal outcomes.
Preterm birth remains the leading challenge in perinatal mortality and morbidity in the developing world. Existing strategies to reduce preterm birth target at risk women and are not suitable as a population strategy because of their expense. However, more than 50% of preterm births are to women with no pre-existing risk factors. Therefore, population based strategies are desirable.
We present the evidence for fish oil supplements as a population based strategy to reduce early preterm birth.
Fish oils act as competitive antagonists of series two prostaglandins and can target premature cervical ripening as a cause of early preterm birth. These oils are safe and well tolerated by pregnant women. Analyses from randomised trials show that fish oils may be promising as a population based strategy for the prevention of early preterm birth.
Preterm birth is the second largest direct cause of child deaths in children younger than 5 years. Yet, data regarding preterm birth (<37 completed weeks of gestation) are not routinely collected by UN agencies, and no systematic country estimates nor time trend analyses have been done. We report worldwide, regional, and national estimates of preterm birth rates for 184 countries in 2010 with time trends for selected countries, and provide a quantitative assessment of the uncertainty surrounding these estimates.
METHODS: We assessed various data sources according to prespecified inclusion criteria. National Registries (563 datapoints, 51 countries), Reproductive Health Surveys (13 datapoints, eight countries), and studies identified through systematic searches and unpublished data (162 datapoints, 40 countries) were included. 55 countries submitted additional data during WHO's country consultation process. For 13 countries with adequate quality and quantity of data, we estimated preterm birth rates using country-level loess regression for 2010. For 171 countries, two regional multilevel statistical models were developed to estimate preterm birth rates for 2010. We estimated time trends from 1990 to 2010 for 65 countries with reliable time trend data and more than 10,000 livebirths per year. We calculated uncertainty ranges for all countries.
FINDINGS: In 2010, an estimated 14·9 million babies (uncertainty range 12·3-18·1 million) were born preterm, 11·1% of all livebirths worldwide, ranging from about 5% in several European countries to 18% in some African countries. More than 60% of preterm babies were born in south Asia and sub-Saharan Africa, where 52% of the global livebirths occur. Preterm birth also affects rich countries, for example, USA has high rates and is one of the ten countries with the highest numbers of preterm births. Of the 65 countries with estimated time trends, only three (Croatia, Ecuador, and Estonia), had reduced preterm birth rates 1990-2010.
INTERPRETATION: The burden of preterm birth is substantial and is increasing in those regions with reliable data. Improved recording of all pregnancy outcomes and standard application of preterm definitions is important. We recommend the addition of a data-quality indicator of the per cent of all live preterm births that are under 28 weeks' gestation. Distinguishing preterm births that are spontaneous from those that are provider-initiated is important to monitor trends associated with increased caesarean sections. Rapid scale up of basic interventions could accelerate progress towards Millennium Development Goal 4 for child survival and beyond.
FUNDING: Bill & Melinda Gates Foundation through grants to Child Health Epidemiology Reference Group (CHERG) and Save the Children's Saving Newborn Lives programme; March of Dimes; the Partnership for Maternal Newborn and Childe Health; and WHO, Department of Reproductive Health and Research.
The objective of this study was to compare the outcome of pregnancy in women diagnosed with gestational diabetes mellitus (GDM) before 24 weeks of gestation with those diagnosed after 24 weeks of gestation.
The records of women with a GDM were reviewed over a 5-year period. All women are routinely screened for GDM at their first prenatal visit before 24 weeks of gestation and if negative, a repeat screening occurs at 24-28 weeks of gestation. Two groups were formed based on gestational age of the diagnosis of GDM, a group diagnosed before 24 weeks of gestation and a group diagnosed after 24 weeks of gestation. Multiple gestations, incomplete records, and delivery before 22 weeks of gestation were excluded. Standard statistics and regression analysis considered P<.05 significant and the study was approved by the institutional review board.
There were 305 women diagnosed with GDM before 24 weeks of gestation and 401 women diagnosed after 24 weeks of gestation included in the study. The GDM before 24 weeks of gestation group was older, had more obese women (body mass index greater than 30 kg/m), delivered earlier, and had a lower birth weight. The groups were similar when comparing cesarean delivery rates, preeclampsia, fetal demise, shoulder dystocia, and macrosomia (birth weight greater than 4,000 g) (). In multivariate regression analysis, diagnosis of GDM before 24 weeks of gestation was an independent predictor of preterm birth (less than 37 weeks of gestation; ).(Table is included in full-text article.)(Table is included in full-text article.)
: The diagnosis of GDM before 24 weeks of gestation is associated with preterm delivery when compared with women diagnosed after 24 weeks of gestation.