Factors determining phage stability/activity: challenges in practical phage application

Introduction: Phages consist of nucleic acids and proteins that may lose their activity under different physico-chemical conditions. The production process of phage formulations may decrease phage infectivity. Ingredients present in the preparation may influence phage particles, although preparation and storage conditions may also cause variations in phage titer. Significant factors are the manner of phage application, the patient’s immune system status, the type of medication being taken, and diet.

Areas covered: We discuss factors determining phage activity and stability, which is relevant for the preparation and application of phage formulations with the highest therapeutic efficacy. Our article should be helpful for more insightful implementation of clinical trials, which could pave the way for successful phage therapy.

Expert opinion: The number of naturally occurring phages is practically unlimited and phages vary in their susceptibility to external factors. Modern methods offer engineering techniques which should lead to enhanced precision in phage delivery and anti-bacterial activity. Recent data suggesting that phages may also be used in treating nonbacterial infections as well as anti-inflammatory and immunomodulatory agents add further weight to such studies. It may be anticipated that different phage activities could have varying susceptibility to factors determining their actions.     

Analysis of the Factors Contributing to Bariatric Success After Laparoscopic Redo Bariatric Procedures: Results from Multicenter Polish Revision Obesity Surgery Study (PROSS)

Introduction

With continuously growing number of redo bariatric surgeries (RBS), it is necessary to look for factors determining success of redo-surgeries.

Patients and methods

A retrospective cohort study analyzed consecutive patients who underwent RBS in 12 referral bariatric centers in Poland from 2010 to 2020. The study included 529 patients. The efficacy endpoints were percentage of excessive weight loss (%EWL) and remission of hypertension (HT) and/or type 2 diabetes (T2D).

Results

Group 1: weight regain

Two hundred thirty-eight of 352 patients (67.6%) exceeded 50% EWL after RBS. The difference in body mass index (BMI) pre-RBS and lowest after primary procedure < 10.6 kg/m2 (OR 2.33, 95% CI: 1.43–3.80, p = 0.001) was independent factor contributing to bariatric success after RBS, i.e., > 50% EWL.

Group 2: insufficient weight loss

One hundred thirty of 177 patients (73.4%) exceeded 50% EWL after RBS. The difference in BMI pre-RBS and lowest after primary procedure (OR 0.76, 95% CI: 0.64–0.89, p = 0.001) was independent factors lowering odds for bariatric success.

Group 3: insufficient control of obesity-related diseases

Forty-three of 87 patients (49.4%) achieved remission of hypertension and/or type 2 diabetes. One Anastomosis Gastric Bypass (OAGB) as RBS was independent factor contributing to bariatric success (OR 7.23, 95% CI: 1.67–31.33, p = 0.008), i.e., complete remission of HT and/or T2D.

Conclusions

RBS is an effective method of treatment for obesity-related morbidity. Greater weight regain before RBS was minimizing odds for bariatric success in patients operated due to weight regain or insufficient weight loss. OAGB was associated with greater chance of complete remission of hypertension and/or diabetes.

Graphical abstract

     

Impact of early-life events on the susceptibility to Clostridium difficile colonisation and infection in the offspring of the pig

Clostridium difficile has been documented as a major cause of uncontrolled outbreaks of enteritis in neonatal pigs and antibiotic-associated infections in clinical settings. It belongs to the natural cohort of early colonisers of the gastrointestinal tract of pigs and can be detected in faeces up to two weeks post-partum. In older pigs, it often remains under the detection limit. Most neonatal pigs show no clinical signs of disease although C. difficile and its toxins can be detected at high levels in faeces. Increased mortality rates associated with C. difficile on pig farms are, so far, considered “spontaneous” and the predisposing factors are mostly not defined. The infection caused by C. difficile is multifactorial and it is likely that the repertoire of maternal factors, host physiology, the individually developing gut microbiota, co-infections and environmental stress define the conditions for disease development. In this addendum to our recently published work on CDI in neonatal piglets, we discuss the “early-life events” that influence C. difficile spread and infection in neonatal piglets.     

Pneumatosis Intestinalis Due to COVID-19 Infection in Kidney Transplant Recipient: A Case Report

BackgroundPneumatosis intestinalis (PI) is a rare condition usually occurring among adults who have undergone solid organ transplant and are taking steroid therapy. The coronavirus disease 2019 (COVID-19) virus uses angiotensin-converting enzyme 2 in gastrointestinal epithelium as a receptor for entry process. Due to the steroid intake, the COVID-19 virus is present in the patient's gastrointestinal tract for extended period of time. It may therefore increase the possibility of PI in such patients. It is usually asymptomatic, with a clinical spectrum ranging from indolent to life-threatening. Unfortunately, there are no algorithms concerning diagnosis and treatment of PI.Aim of studyThe aim of this study is to highlight the problem of PI induced by COVID-19, especially in high-risk groups such as solid organs recipients.ConclusionOn the basis of the presented case of a severe course of COVID-19–induced PI, we conclude that laparotomy with bowel resection can be a feasible and a safe option for treatment.     

Czy u dzieci z nadmiarem masy ciała mogą występować zaburzenia struktury i mineralizacji kości?

The aim of this study was to analyse the quality of bone, determined on the basis of ultrasound in children with excess body weight.