Clinical effectiveness of cefiderocol for the treatment of bloodstream infections due to carbapenem-resistant Acinetobacter baumannii during the COVID-19 era: a single center, observational study

BACKGROUND

We assessed the clinical effectiveness of cefiderocol (CFDC) in comparison with colistin (COL) for the treatment of carbapenem-resistant Acinetobacter baumannii (CRAB) bloodstream infections (BSI).

MATERIALS/METHODS

Retrospective cohort study including adults with CRAB-BSI. Outcomes were mortality, clinical cure and adverse events during therapy. The average treatment effect of CFDC compared to COL was weighted with the inverse-probability treatment weight (IPTW).

RESULTS

Overall, 104 patients were included (50 CFDC, 54 COL), median age 66.5 years, median Charlson Comorbidity Index 5, septic shock in 33.6% of patients. Primary BSI accounted for 43.3% of cases, followed by ventilator-associated pneumonia (VAP) (26%), catheter-related BSI (20.2%) and hospital-acquired pneumonia (HAP) (9.6%). Although not significantly, mortality at all time points was lower for CFDC than COL, while clinical cure was higher in CFDC than COL (66% vs. 44.4%, p = 0.027). Adverse events were more frequent in COL than CFDC-group (38.8% vs. 10%, p < 0.0001), primarily attributed to acute kidney injury (AKI) in the COL group. Patients with bacteremic HAP/VAP treated with CFDC had a significant lower 30-d mortality and higher clinical cure than COL (p = 0.008 and p = 0.0008, respectively). Increment of CCI (p = 0.005), ICU (p = 0.025), SARS-CoV2 (p = 0.006) and ECMO (p < 0.0001) were independently associated with 30-d mortality, while receiving CFDC was not associated with survival.

CONCLUSIONS

CFDC could represent an effective and safe treatment option for CRAB BSI, especially in patients with bacteremic HAP/VAP and frail patients where the risk of acute renal failure during therapy should be avoided.

Porcine milk exosomes modulate the immune functions of CD14+ monocytes in vitro

Exosomes mediate near and long-distance intercellular communication by transferring their molecular cargo to recipient cells, altering their biological response. Milk exosomes (MEx) are internalized by immune cells and exert immunomodulatory functions in vitro. Porcine MEx can accumulate in the small intestine, rich in macrophages. No information is available on the immunomodulatory ability of porcine MEx on porcine monocytes, which are known precursors of gut macrophages. Therefore, this study aims at (1) assessing the in vitro uptake of porcine MEx by porcine monocytes (CD14+), and (2) evaluating the in vitro impact of porcine MEx on porcine monocytes immune functions. MEx were purified by ultracentrifugation and size exclusion chromatography. The monocytes' internalization of PKH26-labeled MEx was examined using fluorescence microscopy. Monocytes were incubated with increasing exosome concentrations and their apoptosis and viability were measured. Lastly, the ability of MEx to modulate the cells' immune activities was evaluated by measuring monocytes' phagocytosis, the capacity of killing bacteria, chemotaxis, and reactive oxygen species (ROS) production. MEx were internalized by porcine monocytes in vitro. They also decreased their chemotaxis and phagocytosis, and increased ROS production. Altogether, this study provides insights into the role that MEx might play in pigs' immunity by demonstrating that MEx are internalized by porcine monocytes in vitro and exert immunomodulatory effects on inflammatory functions.

The Role of Yeast Saccharomyces cerevisiae in Supporting Gut Health in Horses: An Updated Review on Its Effects on Digestibility and Intestinal and Fecal Microbiota

To support the overall health of horses, it is essential to maintain an optimal gut health (GH) status, which encompasses several physiological and functional aspects, including the balance and functionality of intestinal microbial populations and, accordingly, the effective digestion and absorption of nutrients. Numerous biotic and abiotic stressors can lead to an imbalance of GH, such as the quality of forages and the composition of diet, e.g., the inclusion of high energy-dense feeds to meet the energy requirements of performance horses. To support the digestive function and the intestinal microbial populations, the diet can be supplemented with feed additives, such as probiotic yeasts, that promote the ability of cellulolytic bacteria in the hindgut to digest the available fiber fractions, finally increasing feed efficiency. Among the different yeasts available, S. cerevisiae is the most used in horses' nutrition; however, results of digestibility trials, as well as data on intestinal and fecal microbial populations, are sometimes contradictory. Therefore, the purpose of this review is to summarize the effects of S. cerevisiae on in vivo and in vitro digestibility, providing an updated overview of its effects on the intestinal and fecal microbial population.

Immunomodulatory effects of long-chain n-3 polyunsaturated fatty acids (n-3 PUFA) on porcine monocytes (CD14 +) immune response in vitro

Docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) are omega-3 long-chain polyunsaturated fatty acids (n-3 PUFA) found mostly in fish oil. They have been commonly used as dietary integrators in human and animal nutrition, modulating the immune system, mostly by exerting anti-inflammatory activities as demonstrated by in vivo and in vitro studies. The precise mechanisms of action at the background of EPA and DHA immunomodulatory activity are still not fully elucidated. Moreover, no information on their effects on porcine monocytes immune response is available yet. To cover this gap, the study aimed to evaluate DHA and EPA's in vitro impact on porcine monocytes (CD14 +) defensive functions. Briefly, monocytes were isolated from the blood of twenty-six healthy pigs, using a magnetic-activated cell sorting technique (MACS). Monocytes were first treated with increasing concentrations of DHA and EPA (25, 50, 100 and 200 µM) and apoptosis and viability were measured to assess potential cytotoxic effects. Once determined EPA and DHA subtoxic working concentrations (25, 50 and 100 µM), their effects on chemotaxis, phagocytosis and total, intracellular and extracellular reactive oxygen species (ROS) production were evaluated. DHA and EPA only decreased porcine monocytes viability at the highest concentration (200 µM), but their apoptosis was unaffected. DHA (100 µM) decreased the cells' chemotaxis, while EPA (25 µM) increased their intracellular ROS production after 60 min under non-inflammatory or resting conditions and at 90 min under pro-inflammatory conditions (PMA challenge). EPA (50 µM) decreased monocytes' intracellular ROS levels only under resting conditions at 30 min. No effects were observed on porcine monocytes phagocytic capacity. In conclusion, this study demonstrates that DHA and EPA can exert differential in vitro immunomodulatory effects in pigs, by dampening monocytes chemotaxis and potentiating their oxidative burst, respectively. Thus, our results suggest these n-3 PUFA might exert both anti-inflammatory and/or immune-enhancing effects in pigs.

Effects of Saccharomyces cerevisiae hydrolysate on growth performance, immunity function, and intestinal health in broilers

The current study was performed to explore the effects of dietary supplementation of Saccharomyces cerevisiae hydrolysate (SCH) on growth performance, immune function, and intestinal health in broiler chicken. A total of 300 Ross 308 male broilers (1-day-old) were randomly assigned to 2 dietary treatments including a basal diet (control group), and a basal diet supplemented with SCH feed additive (500 mg/kg in starter and grower phase, and 250 mg/kg in finisher phase). Each treatment had 6 replicates with 25 birds each. The results showed that the addition of SCH promoted growth during d 15 to 28 (P < 0.05). Although the addition of SCH had no significant effect on the intestinal relative indexes, it significantly increased the jejunum villus height (VH) and the ratio of villus height to crypt depth (VCR) of jejunum, and decreased the crypt depth (CD) of ileum (P < 0.05). Furthermore, SCH addition significantly downregulated the mRNA expression of immunomodulatory genes (TNF-α, IL-1β, and IL-6), and upregulated the tight junction genes (ZO-1 and Claudin-1) (P < 0.05). High throughput sequencing analysis of bacterial 16S rRNA revealed that dietary SCH supplementation altered cecum microbiota. Alpha diversity analysis showed that a higher bacterial richness in cecum of broilers fed with SCH. The composition of cecum microbiota regulated by SCH addition was characterized by an increased abundance of Firmicutes and a reduced abundance of Bacteroidetes. At the genus level, dietary SCH resulted in a decrease of Bacteroides and an increase of short-chain fatty acids (SCFA) -producing bacteria including Lactobacillus and Faecalibacterium. Taken together, dietary SCH supplementation can stimulate the growth of broilers by regulating the intestinal immunity and barrier function, and improving the intestinal morphology, which may be related to the enhancement of bacterial diversity and the changes of intestinal microbial composition.

Effects of Low ω6:ω3 Ratio in Sow Diet and Seaweed Supplement in Piglet Diet on Performance, Colostrum and Milk Fatty Acid Profiles, and Oxidative Status

Simple Summary

Feeding maternal animals divergent ratios of omega-6 (ω6) and omega-3 (ω3) fatty acids can change not only their health, physiological condition, and performance but also do the same for their offspring. In swine production, various ω6:ω3 ratios have been tested, but the search for an optimal proportion in the sow diet is still in progress. For piglets, weaning oxidative stress has been alleviated by supplementing with abundant sources of bioactive compounds. In this case, brown seaweed, a rich source of natural antimicrobials and antioxidants, can be a good candidate, but its supplementation in piglet diet is limited. This study explores the hypothesis that feeding a low ω6:ω3 ratio diet to sows during gestation and lactation, together with the supplementation of Ascophyllum nodosum for piglets during the post-weaning period, could benefit piglets’ performance and oxidative status more than the respective single treatment provided to the mother or the piglet. Results showed that the low dietary ω6:ω3 ratio (4:1) and seaweed supplement did not affect the post-weaning piglets’ growth rate and oxidative status. However, a low ω6:ω3 ratio diet alone improved weaning survival rate, suckling piglets’ weight gain, and total ω3 fatty acids in colostrum and milk.

Abstract

The ratio of omega-6 (ω6) to omega-3 (ω3) polyunsaturated fatty acids (PUFAs) in the diet contributes to animal health and performance modulations because they have mostly opposite physiological functions. Increasing ω3 PUFAs content in the maternal diet can stimulate antioxidative capacity in sow and piglets; however, the optimal ratio of ω6 and ω3 PUFAs in the sow diet is still under discussion. Rich sources of bioactive constituents such as brown seaweed are an excellent supplementation to promote animal health and antioxidant status. However, the knowledge of the effects of this compound, specifically in post-weaning piglets, is still limited. Moreover, the combined effect of a low ω6:ω3 PUFAs ratio in sow diet and seaweed supplementation in post-weaning piglets’ diet has never been studied. This research aims to assess the combined effect of a low ω6:ω3 ratio in sow diets and seaweed supplementation in piglet diets on their growth and oxidative status. We also assessed the impact of a low ω6:ω3 ratio in the maternal diet on reproduction, milk fatty acid (FA) profile, and plasma leptin concentration. Two sow diets (n = 8 each) contained either a control ratio (CR, 13:1 during gestation, starting from day 28 (G28) and 10:1 during lactation) or a low ratio (LR, 4:1 from G28 until the end of lactation (L-End)) of ω6:ω3 FA by adding soybean oil or linseed oil, respectively. Reproductive performance was evaluated. Colostrum and milk at lactation day 7 (L7) and L-End were collected to analyze FA profile. Plasma was collected at G28, G79, G108, L7, L14, and L-End for determination of leptin and oxidative status. At weaning, 20 male piglets were selected per sow group to form 4 diet treatments (n = 10 each), which were supplemented with or without 4 g/kg seaweed. Recording of growth performance and collection of blood were performed at days 0, 7, 15, and 21 of post-weaning for oxidative status. LR diet increased (p < 0.05) the survival rate of piglets at weaning, and individual and litter weight gains. Colostrum and milk at L7 and L-End had lower (p < 0.05) ω6:ω3 ratio in LR sows. Interaction between dietary treatments on sows and piglets was revealed for all examined growth parameters at most time points (p < 0.05). LR diet did not affect plasma leptin levels and oxidative status. These findings suggest that the seaweed supplement during post-weaning could not improve growth rate and oxidative status of piglets born from mothers receiving a low dietary ω6:ω3 ratio (4:1) during gestation and lactation. However, this low ratio was beneficial for weaning survival rate, sucking piglets’ weight gain, and ω3 enrichment in colostrum and milk.

Neuroendoscopic management of hydrocephalus secondary to midline and pineal lesions

AIM

In patients with space-occupying lesions of the pineal region, increased intracranial pressure is due to direct compression of the sylvian aqueduct. Based on results of the recent literature, neuroendoscopic management of obstructive hydrocephalus, secondary to tumors of the pineal gland, has gained a preeminent role respect to shunting procedures.

METHODS

In 14 select cases, hydrocephalus was secondary to midline and pineal lesions. The patient's age ranged from 1 to 56 years (mean 47.3+/-12.5), with a follow-up ranged from 3 months to 5 years after discharge. In 9 cases the endoscopic procedure represented the only surgical treatment. In 5 cases, microsurgical removal of the lesions and/or ventriculo-peritoneal shunts placement were performed, as additional treatment, while adjuvant radiotherapy was utilized in 4 cases; high dose chemotherapy followed by bone marrow transplantation was performed in 3 cases.

RESULTS

In our series, obstructive hydrocephalus secondary to midline and pineal lesions, was successful treated by neuroendoscopic approach alone in 9 cases, with an unremarkable course and good outcome, except in 1 case.

CONCLUSIONS

Neuroendoscopic approach affords a minimally invasive way to obtain 4 objectives by one-step surgical approach, such as resolution of obstructive hydrocephalus by endoscopic third ventriculostomy (ETV), cerebrospinal fluid sample to detect tumor markers and to perform cytological analysis, biopsy specimens and tissue diagnosis, associated to absence of shunt-related complications. Therefore, in experienced hands, ETV should be the treatment of first choice, in cases of hydrocephalus secondary to lesions of the pineal gland.