The Tn916/Tn1545 Family of Conjugative Transposon

The conjugative transposon Tn916 was first discovered in the late 1970s and is, together with the related conjugative transposon Tn1545, the paradigm of a large family of related conjugative transposons known as the Tn916/Tn1545 family, which are found in an extremely diverse range of bacteria. With the huge increase in bacterial genomic sequence data available, due to the widespread use of next generation sequencing, more putative conjugative transposons belonging to the Tn916/Tn1545 family are being reported. Many of these are capable of excision, integration and conjugation. Nearly all of the Tn916/Tn1545‑like elements discovered to date encode tetracycline resistance however, increasingly resistance to other antimicrobials is being found. Some of the members of the Tn916/Tn1545 family of elements are composite structures which contain smaller mobile genetic elements which are also capable of transposition. Tn916/Tn1545‑like elements themselves are also found within larger and more complex elements. This review will give an overview of the current knowledge of the Tn916/Tn1545 family of conjugative transposons highlighting recently characterized composite elements carrying additional and novel resistance genes

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

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

Plasmids can transfer to Clostridium difficile CD37 and 630Δerm both by a DNase resistant conjugation-like mechanism and a DNase sensitive mechanism

Broad host range conjugative plasmids that replicate in Escherichia coli have been widely used to mobilise smaller replicons, bearing their cognate origin of transfer (oriT) into a variety of organisms that are less tractable genetically, such as Clostridium (Clostridioides) difficile. In this work we demonstrated that the oriT region of pMTL9301 (derived from RK2) is not required for transfer between E. coli and C. difficile strains 630Δerm and CD37 and that this oriT-independent transfer is abolished in the presence of DNase when CD37 is the recipient. Transfer to the 630Δerm strain is DNase resistant even without an obvious oriT, when E. coli CA434 is used as a donor and is sensitive to DNase when E. coli HB101 is the donor

Health and Human Rights in Chin State, Western Burma: A Population-Based Assessment Using Multistaged Household Cluster Sampling

Sollom and colleagues report the findings from a household survey study carried out in Western Burma; they report a high prevalence of human rights violations such as forced labor, food theft, forced displacement, beatings, and ethnic persecution

Local birthing services for rural women: Adaptation of a rural New South Wales maternity service.

OBJECTIVE: To describe the outcomes of a public hospital maternity unit in rural New South Wales (NSW) following the adaptation of the service from an obstetrician and general practitioner-obstetrician (GPO)-led birthing service to a low-risk midwifery group practice (MGP) model of care with a planned caesarean section service (PCS). DESIGN: A retrospective descriptive study using quantitative methodology. SETTING: Maternity unit in a small public hospital in rural New South Wales, Australia. PARTICIPANTS: Data were extracted from the ward-based birth register for 1172 births at the service between July 2007 and June 2012. MAIN OUTCOME MEASURES: Birth numbers, maternal characteristics, labour, birthing and neonatal outcomes. RESULTS: There were 750 births over 29 months in GPO and 277 and 145 births over 31 months in MGP and PCS, respectively, totalling 422 births following the change in model of care. The GPO had 553 (73.7%) vaginal births and 197 (26.3%) caesarean section (CS) births (139 planned and 58 unplanned). There were almost universal normal vaginal births in MGP (>99% or 276). For normal vaginal births, more women in MGP had no analgesia (45.3% versus 25.1%) or non-invasive analgesia (47.9% versus 38.6%) and episiotomy was less common in MGP than GPO (1.9% versus 3.4%). Neonatal outcomes were similar for both groups with no difference between Apgar scores at 5 min, neonatal resuscitations or transfer to high-level special care nurseries. CONCLUSION: This study demonstrates how a rural maternity service maintained quality care outcomes for low-risk women following the adaptation from a GPO to an MGP service

Neonatal hypothermia and associated risk factors among newborns of southern Nepal

<p>Abstract</p> <p>Background</p> <p>Neonatal hypothermia is associated with an increased mortality risk for 28 days. There are few community-based data on specific risk factors for neonatal hypothermia. Estimates of association between neonatal hypothermia in the community and risk factors are needed to guide the design of interventions to reduce exposure.</p> <p>Methods</p> <p>A cohort of 23,240 babies in rural southern Nepal was visited at home by field workers who measured axillary temperatures for 28 days (213,316 temperature measurements). The cumulative incidence of hypothermia (defined as < 35.0°C based on an analysis of the hypothermia-mortality risk relationship) was examined for any association with infant characteristics, care practices and parental, household, socioeconomic and demographic factors. Estimates were adjusted for age and ambient temperature.</p> <p>Results</p> <p>Ten percent of the babies (<it>n </it>= 2342) were observed with temperatures of < 35.0°C. Adjusted prevalence ratios (Adj PR) were increased among those who weighed < 2000 g [Adj PR = 4.32 (3.73, 5.00)] or < 1500 g [Adj PR = 11.63 (8.10, 16.70)] compared to those of normal weight (> 2500 g). Risk varied inversely along the entire weight spectrum: for every 100 g decrement hypothermia risk increased by 7.4%, 13.5% and 31.3%% for babies between 3000 g and 2500 g, 2500 g and 2000 g and < 2000 g, respectively. Preterm babies (< 34 weeks), females, those who had been first breastfed after 24 h and those with hypothermic mothers were at an increased risk. In the hot season the risk disparity between smaller and larger babies increased. Hypothermia was not associated with delayed bathing, hat wearing, room warming or skin-to-skin contact: they may have been practiced reactively and thereby obscured any potential benefit.</p> <p>Conclusions</p> <p>In addition to season in which the babies were born, weight is an important risk factor for hypothermia. Smaller babies are at higher relative risk of hypothermia during the warm period and do not receive the protective seasonal benefit apparent among larger babies. The need for year-round thermal care, early breastfeeding and maternal thermal care should be emphasized. Further work is needed to quantify the benefits of other simple neonatal thermal care practices.</p

Minocycline resistance in an oral Streptococcus infantis isolate is encoded by tet(S) on a novel small, low copy number plasmid.

We have determined the genetic basis of minocycline resistance in a strain of Streptococcus infantis isolated from a healthy human oral cavity. We demonstrate that tet(S), identical to tet(S) found on the enterococcal conjugative transposon Tn6000, is responsible for the observed resistance. The gene is located on a small, low copy number plasmid and is flanked by IS1216 elements. The tet(S) gene is capable of excising from the plasmid together with one of the IS1216 elements. The plasmid contains a putative toxin/antitoxin system related to relBE. Deletion of the toxin, relE, did not result in plasmid instability but did increase the fitness of the mutant compared to the wild-type strain

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

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

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

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

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