Intestinal ischemia in the COVID-19 era: case series from peripheral healthcare centre

Coronavirus disease-2019 (COVID-19) caused by SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) has caused global health crisis. Initially considered a respiratory tract pathogen, it can cause multiple organ dysfunction. It has also been described to predispose to venous and arterial thromboembolism; however, limited published data is available regarding mesenteric thrombosis COVID-19. We report 6 cases of COVID-19 positive patients with mesenteric/intestinal ischemia. These patients were examined with variables including demographics, laboratory blood tests including coagulation panels, medical and surgical history, comorbidities, and postoperative follow-up period.

‘Mycoplasma hominis does not share common risk factors with other genital pathogens’: Findings from a South African pregnant cohort

Background: The role of Mycoplasma hominis (M. hominis) as a genital tract pathogen was still debatable. This study identified the risk factors associated with the prevalence of M. hominis in South African pregnant women.Methods: This was a cross-sectional analysis of n = 221 prenatal patients attending a Durban hospital during November 2017 to April 2018. M. hominis was detected from urine samples using the quantitative polymerase chain reaction. The population characteristics were described using frequencies stratified by the infection status of M. hominis. In addition, a univariate analysis was used to assess the relationship between each risk factor and infection status. The analysis further considered logistic regression to assess the influence of these risk factors univariately and in the presence of other factors. The coinfection rate between M. hominis and bacterial vaginosis (BV), Trichomonas vaginalis (T. vaginalis), Mycoplasma genitalium (M. genitalium) and Candida species was also determined. All the tests were conducted at 5% level of significance.Results: The prevalence of M. hominis in this study population was 48% (106/221). In the univariate analysis, factors significantly associated with M. hominis positivity included having past abnormal vaginal discharge (p = 0.037), having current abnormal vaginal discharge (p = 0.010) and a borderline significance (p = 0.052), which were noted for previous pre-term delivery. However, none of these factors were sustained in the multivariate analysis. There was a statistically significant association between M. hominis and BV positivity (p 0.001). Similarly, M. hominis and M. genitalium positivity was significant (p = 0.006).Conclusion: This study showed that M. hominis does not share common risk factors with known genital tract pathogens in a population of pregnant women and therefore cannot be considered a genital tract pathogen.

Mapping the functional landscape of the receptor binding domain of T7 bacteriophage by deep mutational scanning

The interaction between a bacteriophage and its host is mediated by the phage's receptor binding protein (RBP). Despite its fundamental role in governing phage activity and host range, molecular rules of RBP function remain a mystery. Here, we systematically dissect the functional role of every residue in the tip domain of T7 phage RBP (1660 variants) by developing a high-throughput, locus-specific, phage engineering method. This rich dataset allowed us to cross compare functional profiles across hosts to precisely identify regions of functional importance, many of which were previously unknown. Substitution patterns showed host-specific differences in position and physicochemical properties of mutations, revealing molecular adaptation to individual hosts. We discovered gain-of-function variants against resistant hosts and host-constricting variants that eliminated certain hosts. To demonstrate therapeutic utility, we engineered highly active T7 variants against a urinary tract pathogen. Our approach presents a generalized framework for characterizing sequence–function relationships in many phage–bacterial systems.

Evaluation of inhibitory activity of domestic probiotics for against invasion and infection by Proteus mirabilis in the urinary tract

Introduction: Approximately 5% of men and 40%–50% of women have experienced urinary tract infections (UTI), which are the most common infectious diseases and nosocomial infections in humans. Proteus mirabilis is susceptible to most antibiotics, but antibiotic treatment usually causes side effects. In this research, lactic acid bacteria (LAB) was assessed for its inhibitory activity against a urinary tract pathogen. Methodology: We studied the effect of pH adjustment, heat, and enzyme treatments on the inhibitory activity of LAB strains and their supernatants, using well-diffusion and co-culture assays. In the cell culture assay, anti-adhesion and anti-invasion activities against P. mirabilis were tested with SV-HUC-1 urothelial cells. Results: LAB were able to adhere to the urothelial cells and inhibited P. mirabilis growth. LAB were also able to inhibit P. mirabilis adhesion to or invasion of SV-HUC-1 urothelial cells. Finally, in the competition assay, LAB showed inhibitory effects against P. mirabilis. LAB could also inhibit the invasion of P. mirabilis into urothelial cells. Conclusions: Two LAB strains (PM206 and 229) exhibited antagonistic activity against P. mirabilis adhesion or invasion of urothelial cells in culture. In the future, probiotics may be used in food or urinary tract cleansing and could replace antibiotic treatments.

The use of mucolytic therapy in the treatment of infectious and inflammatory diseases of the respiratory tract

The article is devoted to the use of mucolytic therapy in the treatment of infectious and inflammatory diseases of the respiratory tract. Pathogen exposure results in an increase in the viscosity and adhesion of the respiratory tract mucus and leads to an impairment of drainage function and mucociliary clearance of the bronchi. Given the pathogenetic features, the primary goal of the treatment is to change the rheological properties of sputum and remove mucus from the respiratory tract. This justifies the administration of mucolytics, taking into account their pharmacological characteristics.