517 research outputs found

    Mobile genetic elements in Clostridium difficile and their role in genome function.

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    Approximately 11% the Clostridium difficile genome is made up of mobile genetic elements which have a profound effect on the biology of the organism. This includes transfer of antibiotic resistance and other factors that allow the organism to survive challenging environments, modulation of toxin gene expression, transfer of the toxin genes themselves and the conversion of non-toxigenic strains to toxin producers. Mobile genetic elements have also been adapted by investigators to probe the biology of the organism and the various ways in which these have been used are reviewed

    Horizontal gene transfer converts non-toxigenic Clostridium difficile strains into toxin producers.

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    Clostridium difficile is a major nosocomial pathogen and the main causative agent of antibiotic-associated diarrhoea. The organism produces two potent toxins, A and B, which are its major virulence factors. These are chromosomally encoded on a region termed the pathogenicity locus (PaLoc), which also contains regulatory genes, and is absent in non-toxigenic strains. Here we show that the PaLoc can be transferred from the toxin-producing strain, 630Δerm, to three non-toxigenic strains of different ribotypes. One of the transconjugants is shown by cytotoxicity assay to produce toxin B at a similar level to the donor strain, demonstrating that a toxigenic C. difficile strain is capable of converting a non-toxigenic strain to a toxin producer by horizontal gene transfer. This has implications for the treatment of C. difficile infections, as non-toxigenic strains are being tested as treatments in clinical trials

    TetAB46, a predicted heterodimeric ABC transporter conferring tetracycline resistance in Streptococcus australis isolated from the oral cavity.

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    OBJECTIVES: To identify the genes responsible for tetracycline resistance in a strain of Streptococcus australis isolated from pooled saliva from healthy volunteers in France. S. australis is a viridans Streptococcus, originally isolated from the oral cavity of children in Australia, and subsequently reported in the lungs of cystic fibrosis patients and as a cause of invasive disease in an elderly patient. METHODS: Agar containing 2 mg/L tetracycline was used for the isolation of tetracycline-resistant organisms. A genomic library in Escherichia coli was used to isolate the tetracycline resistance determinant. In-frame deletions and chromosomal repair were used to confirm function. Antibiotic susceptibility was determined by agar dilution and disc diffusion assay. RESULTS: The tetracycline resistance determinant from S. australis FRStet12 was isolated from a genomic library in E. coli and DNA sequencing showed two open reading frames predicted to encode proteins with similarity to multidrug resistance-type ABC transporters. Both genes were required for tetracycline resistance (to both the naturally occurring and semi-synthetic tetracyclines) and they were designated tetAB(46). CONCLUSIONS: This is the first report of a predicted ABC transporter conferring tetracycline resistance in a member of the oral microbiota

    Skin, Thermal and Umbilical Cord Care Practices for Neonates in Southern, Rural Zambia: A Qualitative Study

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    Background: In Choma District, southern Zambia, the neonatal mortality rate is approximately 40 per 1000 live births and, although the rate is decreasing, many deliveries take place outside of formal facilities. Understanding local practices during the postnatal period is essential for optimizing newborn care programs. Methods: We conducted 36 in-depth interviews, five focus groups and eight observational sessions with recently-delivered women, traditional birth attendants, and clinic and hospital staff from three sites, focusing on skin, thermal and cord care practices for newborns in the home. Results: Newborns were generally kept warm by application of hats and layers of clothing. While thermal protection is provided for preterm and small newborns, the practice of nighttime bathing with cold water was common. The vernix was considered important for the preterm newborn but dangerous for HIV-exposed infants. Mothers applied various substances to the skin and umbilical cord, with special practices for preterm infants. Applied substances included petroleum jelly, commercial baby lotion, cooking oil and breastmilk. The most common substances applied to the umbilical cord were powders made of roots, burnt gourds or ash. To ward off malevolent spirits, similar powders were reportedly placed directly into dermal incisions, especially in ill children. Conclusions: Thermal care for newborns is commonly practiced but co-exists with harmful practices. Locally appropriate behavior change interventions should aim to promote chlorhexidine in place of commonly-reported application of harmful substances to the skin and umbilical cord, reduce bathing of newborns at night, and address the immediate bathing of HIV-infected newborns

    Association between Nutritional Status and Positive Childhood Disability Screening Using the Ten Questions Plus Tool in Sarlahi, Nepal

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    The study was conducted to examine the association between the indicators of malnutrition and disability of children as reported by caregivers. The Ten Questions Plus questionnaire was administered to caregivers of 1,902 children aged 1–9 years, during August 2007–March 2008, in rural Nepal. Height and weight of children were also measured. The main outcome was a positive response to one or more questions. In total, 514 (27%) children had a positive response to at least one question. Moderate stunting [odds ratio (OR)=1.47, 95% confidence interval (CI) 1.02–2.12) and severe (OR=2.39, 95% CI 1.60–3.57) stunting were independently associated with reported delay in sitting, standing, or walking. Severe stunting was also associated with report of delayed learning compared to other children of similar age (OR=2.01, 95% CI 1.27–3.20). Parental report of disability was quite prevalent in this setting, with over a quarter of the sample screening positive. Chronic malnutrition may be associated with delayed motor and mental development

    Perceptions, careseeking, and experiences pertaining to non-cephalic births in rural Sarlahi District, Nepal: a qualitative study.

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    BACKGROUND: In low-resource settings, a significant proportion of fetal, neonatal, and maternal deaths can be attributed to intrapartum-related complications. Certain risk factors, such as non-cephalic presentation, have a particularly high risk of complications. This qualitative study describes experiences around non-cephalic births and highlights existing perceptions and care-seeking behavior specific to non-cephalic presentation in rural Sarlahi District, Nepal. METHODS: We conducted in-depth interviews with 34 individuals, including women who recently gave birth to a non-cephalic infant and female decision-makers in their households. We also conducted two focus groups with mothers (have two or more children, with at least one child under age five) and two focus groups with grandmothers in the community. RESULTS: Several women described scenes of obstructed labor and practices like provision of unspecified injections early in labor to assist with the delivery. There were reports of arduous care-seeking processes from primary health centers to tertiary facilities, and mixed quality of care among home birth attendants and facility-based health workers respectively. Very few women were aware of the fetal presentation prior to delivery, and we identified no consistent understanding among participants of the risks of and care strategies for non-cephalic births. Risk perception around non-cephalic presentation varied widely. Some participants were acutely aware of potential dangers, while others had not heard of non-cephalic birth. Many interviewees said that the position in which a pregnant woman sleeps could impact the fetal position. Several participants had either taken or heard of medication intended to rotate the fetus into the correct position. CONCLUSIONS: Our findings suggest the mixed quality of and access to care associated with non-cephalic birth and a lack of consistent understanding of the risk of and care for non-cephalic births in rural Nepal. The high risk of the condition and the recommended tertiary care present a dilemma in low-resource settings; the logistical difficulties and the mixed quality of care make care-seeking and referral decisions complex. While public health stakeholders strive to improve the quality of and access to the formal health system, those players must also be sensitive to the potential negative implications of promoting institutional care-seeking

    Clean birth and postnatal care practices to reduce neonatal deaths from sepsis and tetanus: a systematic review and Delphi estimation of mortality effect

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    BACKGROUND: Annually over 520,000 newborns die from neonatal sepsis, and 60,000 more from tetanus. Estimates of the effect of clean birth and postnatal care practices are required for evidence-based program planning. OBJECTIVE: To review the evidence for clean birth and postnatal care practices and estimate the effect on neonatal mortality from sepsis and tetanus for the Lives Saved Tool (LiST). METHODS: We conducted a systematic review of multiple databases. Data were abstracted into standard tables and assessed by GRADE criteria. Where appropriate, meta-analyses were undertaken. For interventions with low quality evidence but a strong GRADE recommendation, a Delphi process was conducted. RESULTS: Low quality evidence supports a reduction in all-cause neonatal mortality (19% (95% c.i. 1-34%)), cord infection (30% (95% c.i. 20-39%)) and neonatal tetanus (49% (95% c.i. 35-62%)) with birth attendant handwashing. Very low quality evidence supports a reduction in neonatal tetanus mortality with a clean birth surface (93% (95% c.i. 77-100%)) and no relationship between a clean perineum and tetanus. Low quality evidence supports a reduction of neonatal tetanus with facility birth (68% (95% c.i. 47-88%). No relationship was found between birth place and cord infections or sepsis mortality. For postnatal clean practices, all-cause mortality is reduced with chlorhexidine cord applications in the first 24 hours of life (34% (95% c.i. 5-54%, moderate quality evidence) and antimicrobial cord applications (63% (95% c.i. 41-86%, low quality evidence). One study of postnatal maternal handwashing reported reductions in all-cause mortality (44% (95% c.i. 18-62%)) and cord infection ((24% (95% c.i. 5-40%)).Given the low quality of evidence, a Delphi expert opinion process was undertaken. Thirty experts reached consensus regarding reduction of neonatal sepsis deaths by clean birth practices at home (15% (IQR 10-20)) or in a facility (27% IQR 24-36)), and by clean postnatal care practices (40% (IQR 25-50)). The panel estimated that neonatal tetanus mortality was reduced by clean birth practices at home (30% (IQR(20-30)), or in a facility (38% (IQR 34-40)), and by clean postnatal care practices (40% (IQR 30-50)). CONCLUSION: According to expert opinion, clean birth and particularly postnatal care practices are effective in reducing neonatal mortality from sepsis and tetanus. Further research is required regarding optimal implementation strategies

    Does gender matter? A cross-national investigation of primary class-room discipline.

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    © 2018 Informa UK Limited, trading as Taylor & Francis GroupFewer than 15% of primary school teachers in both Germany and the UK are male. With the on-going international debate about educational performance highlighting the widening gender achievement gap between girl and boy pupils, the demand for more male teachers has become prevalent in educational discourse. Concerns have frequently been raised about the underachievement of boys, with claims that the lack of male ‘role models’ in schools has an adverse effect on boys’ academic motivation and engagement. Although previous research has examined ‘teaching’ as institutional talk, men’s linguistic behaviour in the classroom remains largely ignored, especially in regard to enacting discipline. Using empirical spoken data collected from four primary school classrooms in both the UK and in Germany, this paper examines the linguistic discipline strategies of eight male and eight female teachers using Interactional Sociolinguistics to address the question, does teacher gender matter?Peer reviewedFinal Accepted Versio

    The effect of umbilical cord cleansing with chlorhexidine on omphalitis and neonatal mortality in community settings in developing countries: a meta-analysis.

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    BACKGROUND: There is an increased risk of serious neonatal infection arising through exposure of the umbilical cord to invasive pathogen in home and facility births where hygienic practices are difficult to achieve. The World Health Organization currently recommends 'dry cord care' because of insufficient data in favor of or against topical application of an antiseptic. The primary objective of this meta-analysis is to evaluate the effects of application of chlorhexidine (CHX) to the umbilical cord to children born in low income countries on cord infection (omphalitis) and neonatal mortality. Standardized guidelines of Child Health Epidemiology Reference Group (CHERG) were followed to generate estimates of effectiveness of topical chlorhexidine application to umbilical cord for prevention of sepsis specific mortality, for inclusion in the Lives Saved Tool (LiST). METHODS: Systematic review and meta-analysis. Data sources included Cochrane Central Register of Controlled Trials (CENTRAL) in the Cochrane Library, PubMed, CINHAL and WHO international clinical trials registry. Only randomized trials were included. Studies of children in hospital settings were excluded. The comparison group received no application to the umbilical cord (dry cord care), no intervention, or a non-CHX intervention. Primary outcomes were omphalitis and all-cause neonatal mortality. RESULTS: There were three cluster-randomised community trials (total participants 54,624) conducted in Nepal, Bangladesh and Pakistan that assessed impact of CHX application to the newborn umbilical cord for prevention of cord infection and mortality. Application of any CHX to the umbilical cord of the newborn led to a 23% reduction in all-cause neonatal mortality in the intervention group compared to control [RR 0.77, 95 % CI 0.63, 0.94; random effects model, I2=50 %]. The reduction in omphalitis ranged from 27 % to 56 % compared to control group depending on severity of infection. Based on CHERG rules, effect size for all-cause mortality was used for inclusion to LiST model as a proxy for sepsis specific mortality. CONCLUSIONS: Application of CHX to newborn umbilical cord can significantly reduce incidence of umbilical cord infection and all-cause mortality among home births in community settings. This inexpensive and simple intervention can save a significant number of newborn lives in developing countries
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