Comparative genomics of a drug-resistant Pseudomonas aeruginosa panel and the challenges of antimicrobial resistance prediction from genomes

Antimicrobial resistance (AMR) is now recognized as a global threat to human health. The accessibility of microbial whole-genome sequencing offers an invaluable opportunity for resistance surveillance via the resistome, i.e. the genes and mutations underlying AMR. Unfortunately, AMR prediction from genomic data remains extremely challenging, especially for species with a large pan-genome. One such organism, for which multidrug-resistant (MDR) isolates are frequently encountered in the clinic, is Pseudomonas aeruginosa. This study focuses on a commercially available panel of seven MDR P. aeruginosa strains. The main goals were to sequence and compare these strains' genomes, attempt to predict AMR from whole genomes using two different methods and determine whether this panel could be an informative complement to the international P. aeruginosa reference panel. As expected, the results highlight the complexity of associating genotype and AMR phenotype in P. aeruginosa, mainly due to the intricate regulation of resistance mechanisms. Our results also urge caution in the interpretation of predicted resistomes regarding the occurrence of gene identity discrepancies between strains. We envision that, in addition to accounting for the genomic diversity of P. aeruginosa, future development of predictive tools will need to incorporate a transcriptomic, proteomic and/or metabolomic component.

Effect of estetrol on Beta-Endorphin level in female rats

INTRODUCTION

Estetrol (E4), a naturally occurring estrogen produced exclusively by human fetal liver, is currently being evaluated for potential use in contraception and menopausal care in humans. The present study was designed to profile E4 effects on the central nervous system, to assess the in vivo effects of E4 administration on Beta-Endorphin (β-END) release in specific brain structures and to evaluate whether E4 has synergic or antagonistic effects on estradiol-mediated β-END synthesis.

EXPERIMENTAL

Intact female adult rats received different doses of E4 and ovariectomized (OVX) rats received different doses of E4 or E2V or combinations of both drugs. The concentrations of β-END were assessed in the frontal and parietal cortex, hippocampus, hypothalamus, neurointermediate lobe, anterior pituitary and plasma.

RESULTS

E4 at the dose of 1mg/kg/day did not alter β-END content in most brain areas, as well as, plasma levels of intact animals E4 administered at a dose of 5mg/kg/day decreased β-END content in the hippocampus, hypothalamus, and in the neurointermediate lobe, as well as, plasma levels, compared to intact animals receiving vehicle. E4 increased β-END values in the frontal cortex, but not in the plasma, following the administration of 1mg/kg/day in OVX rats, whereas treatment with 5mg/kg/day in OVX rats induced a significant increase in β-END levels in most brain areas and in the plasma. However, in the presence of estradiol, E4 showed an estrogen-antagonistic effect in selected brain structures at the dose of 5mg/kg/day and in plasma levels of β-END at the dose of 1mg/kg/day and 5mg/kg/day.

CONCLUSION

In OVX rats, E4 increases CNS and peripheral levels of β-END, behaving as a weak estrogen-agonist. The antagonistic effect observed after combined estradiol and E4 administration further profiles E4 as a natural SERM.

Evaluation of adhesions after laparoscopic myomectomy using the Harmonic Ace and the auto-crosslinked hyaluronan gel vs Ringer's lactate solution

OBJECTIVE

To evaluate the efficacy of a crosslinked hyaluronic acid (HA) for the prevention of postsurgical adhesions after laparoscopic myomectomy using the Harmonic Ace.

MATERIALS AND METHODS

Women 23-42 years of age who wished to conceive underwent laparoscopic myomectomy. As adhesion preventing agents, crosslinked HA gel was applied on the myometrial scar at the end of the surgery in Group A, whereas in Group B a Ringer's lactate solution was used in a prospective, observational study. Second-look mini-laparoscopy was performed 45-60 days after surgery and the adhesions were assessed according to a site-specific modified scoring.

RESULTS

The incidence of postoperative adhesions was the same in both groups, but anatomically significant adhesions and site-specific modified score was significantly reduced in Group A compared to Group B control group (31.8% vs 54.6% and 1.05 +/- 1 vs 2.27 +/- 2.5, respectively).

CONCLUSION

The use of auto-cross-linked HA gel confirms a protection on adhesion formation on myometrial wounds, although the degree of this effect appears to be weak. The absence of adnexa adhesions using the HA and a different uterine incision appear remarkable, although a larger number of patients is required to confirm the present findings.

Fertility and endocrine outcome after robot-assisted laparoscopic myomectomy (RALM)

INTRODUCTION

Laparoscopic myomectomy has recently gained wide acceptance but this procedure remains technically highly demanding and concerns have been raised about the increased blood loss and an higher risk of postoperative uterine rupture of the pregnant uterus.

OBJECTIVE

The aim of the present study is to evaluate the fertility and endocrine outcome in women underwent robot-assisted laparoscopic myomectomy (RALM).

METHODS

Data from 48 RALM performed in our department between the years 2007 and 2011 have been collected. Conception rate, abortion rate, incidence of feto-maternal morbidity or severe pregnancy and labor-related complications were reported; FSH and AMH levels and ultrasound valuation of AFC has been made before and 6 months after operation. Number of cesarean sections and vaginal deliveries were described.

RESULTS

The average age of the patients was 35 years and median Body Mass Index was 23 kg/m(2) (range 18-35 kg/m(2)). Seven women (13%) became pregnant after RALM with eight pregnancies. One pregnancy is actually on going; there were six deliveries with caesarian section and one spontaneous delivery. No spontaneous abortions. No uterine ruptures occurred. No significant modification of ovarian function was found after myomectomy.

CONCLUSION

RALM seems to have a favorable impact on the reproductive outcome of young patients with no impact on the ovarian function.

Evaluation of brain-derived neurotrophic factor in menstrual blood and its identification in human endometrium

The presence of high-affinity brain-derived neurotrophic factor receptor Trk B in mouse and in human fetal oocytes, together with the presence of neurotrophins in human follicular fluid suggests a paracrine role for brain-derived neurotrophic factor (BDNF) in female biology. This study aims to evaluate if BDNF is present and quantitatively determined in human menstrual blood and endometrium. Twenty-one women were studied and subdivided in two groups: A, 11 fertile women (27 ± 2 days cycle length) and B, 10 anovulatory women and/or women with inadequate luteal phase (36 ± 2 days cycle length). In fertile women menstrual BDNF levels was higher than plasma (679.3 ± 92.2 vs 301.9 ± 46.7 pg/ml p <0.001). Similarly, in Group B, BDNF in menstrual blood was higher than plasma (386.1 ± 85.2 vs 166.8 ± 24.1 pg/ml p < 0.001). Moreover, both menstrual and plasma BDNF concentrations in Group A were significantly higher respect to Group B (679.3 ± 92.2 vs 386.1 ± 85.2 pg/ml p < 0.001; 301.9 ± 46.7 vs 166.8 ± 24.1 pg/ml p < 0.001). Immunohistochemistry evidence of BDNF in endometrium, during follicular and luteal phase, was also shown. The detection of BDNF in the human menstrual blood and endometrium further supports the role of this neurotrophin in female reproductive function.

Influence of endogenous and exogenous sex hormones on plasma brain-derived neurotrophic factor

BACKGROUND

Brain-derived neurotrophic factor (BDNF) is a mediator of neuronal plasticity and influences learning, memory and cognitive behaviour. The aim of this study is to assess plasma BDNF variations according to hormonal status.

METHODS

A total of 60 subjects were included: 20 fertile ovulatory women, 15 amenorrhoeic women and 25 postmenopausal women. Blood samples were collected after overnight fasting. For 5 out of the 20 fertile women, samples were collected every 2 days throughout the whole menstrual cycle. Following basal evaluation, 10 out of 25 postmenopausal women were administered a hormone replacement therapy (HRT) and reevaluated after 6 months of treatment. Plasma BDNF concentrations were measured by enzyme-linked immunosorbent assay. In fertile women, estradiol (E(2)), progesterone and gonadotrophins were also assessed.

RESULTS

In fertile women, luteal phase levels of plasma BDNF were significantly higher than follicular phase levels (P < 0.001). BDNF increased from early follicular phase up to Day 14 of the cycle, reaching a pre-ovulatory peak, similar to E(2). A second rise took place during mid-luteal phase, with a peak on Day 24. Amenorrhoeic subjects, as well as postmenopausal women, showed significantly lower plasma BDNF levels compared with fertile females (P < 0.001). BDNF was positively correlated with E(2) and progesterone and negatively correlated with menopausal age. HRT restored BDNF levels to those present in fertile women during the follicular phase.

CONCLUSIONS

Plasma BDNF levels are influenced by hormonal status. Modifications in BDNF circulating levels during the menstrual cycle suggest a potential role for gonadal sex hormones (E(2) and progesterone) in regulating neurotrophin expression.

Progesterone and progestins: effects on brain, allopregnanolone and beta-endorphin

The increased use of hormonal therapies over the last years has led to improve the knowledge of pharmacological, biochemical and metabolic properties of several progestins and their effects in target tissues, such as the central nervous system. Progesterone and synthetic progestational agents are able to modulate the synthesis and release of several neurotransmitters and neuropeptides in response to specific physiological and pathological stimuli. While these actions may relay on differential activation of progesterone receptor or recruitment of intracellular pathways, some of the differences found between synthetic progestins may depend on the specific conversion to neuroactive steroids, such as the 3-alpha, 5-alpha reduced metabolite, allopregnanolone. This is a potent endogenous steroid that rapidly affects the excitability of neurons and glia cells through direct modulation of the GABA-A receptors activity exerting hypnotic/sedative, anxiolytic, anaesthetic and anticonvulsive properties. Estrogens increase the CNS and serum levels of allopregnanolone and the addition of certain but not all synthetic progestins determines a further increase in allopregnanolone levels, suggesting that the metabolism into this reduced product is related to the chemical structure of progestin molecule used. In addition, depending on specific progestin molecule used, different interaction are found with the estradiol-induced beta-endorphin synthesis and release, showing that diverse progestins have specific and divergent actions on the opiatergic system. These results highlight the concept that natural and synthetic progesterone receptor agonists may systematically induce different biological actions in CNS. This may have far-reaching implications for the clinical effects and related indications of each compound.