Galleria mellonella larvae as an alternative model to determine the pathogenicity of avian pathogenic Escherichia coli.

RESEARCH HIGHLIGHTS: Galleria mellonella larvae are a viable model for determining APEC pathogenicity.Larval disease score is the main variable for determining APEC pathogenicity.Response variables should be evaluated up to 24 h post-inoculation.

Evaluation of Mastadenovirus and Rotavirus Presence in Phyllostomid, Vespertilionid, and Molossid Bats Captured in Rio Grande do Sul, Southern Brazil.

Bat-borne viruses may affect public health and the global economy. These mammals have a wide geographical distribution and unique biological, physiological, and immunogenic characteristics, allowing the dissemination of many known and unknown viruses. Enteric viruses, such as adeno (AdV) and rotaviruses, are recognized as the main causative agents of disease and outbreaks. In the present study, the presence of viruses from Adenoviridae and Reoviridae families was evaluated in molossid, phyllostomid, and vespertilionid bats captured in Rio Grande do Sul, Southern Brazil, between September 2021 and July 2022. Sixty bat rectal swabs were analyzed by PCR. Eight (13.3%) samples were positive for adenovirus and classified as human mastadenovirus C (HAdV-C) (three samples) and HAdV-E (five samples) by sequencing followed by phylogenetic analysis. All samples were negative in rotavirus specific RT-PCR. This is the first study to describe the presence of HAdV in samples of Glossophaga soricina, Eptesicus brasiliensis, and Histiotus velatus. Furthermore, the presence of HAdV-E in bats was reported, which is unusual and may suggest that other HAdV genotypes, in addition to HAdV-C, may also be harbored by wild animals. The data generated in the present study reinforces the importance of eco-surveillance of viral agents related to diseases in humans and wild animals. In addition, it is essential to identify possible new hosts or reservoirs that increase the risk of spillover and dissemination of infectious pathogens, helping to prevent and control zoonotic diseases.

Conservative Versus Surgical Management of Acute Appendicitis: A Systematic Review.

Recent studies have discussed the role of antibiotic treatment in the conservative management of acute appendicitis and whether antibiotics are a safe option to replace appendicectomy, which has been the gold standard treatment of acute appendicitis for many years. The bibliographic databases Cumulative Index to Nursing and Allied Health Literature (CINAHL), Cochrane, Embase, Medline, and PubMed comparing conservative versus surgical treatment of acute appendicitis were systematically searched according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Twenty-one studies consisting of systematic reviews and meta-analyses involving 44,699 participants were identified. At least 17,865 participants were treated with antibiotics. Our studies compare antibiotic versus appendicectomy among acute appendicitis patients ranging from 7 to 94 years of age. In most studies, patients received parenteral antibiotics for a total of one to three days, and oral antibiotics such as oral cephalosporin plus metronidazole, oral amoxicillin/clavulanate, oral fluoroquinolones plus Tinidazole upon hospital discharge for a total of 7 to 10 days. The total course of antibiotics for both parenteral and oral regimes ranged from 2 to 16 days, with 10 days being the commonest duration. The recurrence rate following initial antibiotic treatment at one-year follow-up ranged from 13% to 38%, while the mean duration of recurrence ranged from three to eight months. The majority of the patients with recurrence underwent appendicectomy, while some patients were either given a repeat or different course of antibiotics due to the possible presence of antibiotic resistance; however, only 2.4% of the patients were successfully treated upon completion of the second course of antibiotics. Most of the studies concluded that appendicectomy remains the gold standard treatment for uncomplicated acute appendicitis, given its higher efficacy and lower complication rates. Although antibiotic treatment cannot be routinely recommended, it can be considered an appropriate alternative in selected patients with uncomplicated appendicitis who wish to avoid surgery and also acknowledge the risk of recurrence and the potential need for subsequent surgery at the same time.

Characterization of avian pathogenic Escherichia coli isolates based on biofilm formation, ESBL production, virulence-associated genes, and phylogenetic groups.

Escherichia coli is a part of both animal and human commensal microbiota. Avian pathogenic E. coli (APEC) is responsible for colibacillosis in poultry, an economically important disease. However, the close similarities among APEC isolates make it difficult to differentiate between pathogenic and commensal bacteria. The aim of this study was to determine phenotypic and molecular characteristics of APEC isolates and to compare them with their in vivo pathogenicity indices. A total of 198 APEC isolates were evaluated for their biofilm-producing ability and extended-spectrum ß-lactamase (ESBL) production phenotypes. In addition, 36 virulence-associated genes were detected, and the isolates were classified into seven phylogenetic groups using polymerase chain reaction. The sources of the isolates were not associated with biofilms, ESBL, genes, or phylogroups. Biofilm and ESBL production were not associated with pathogenicity. Group B2 had the highest pathogenicity index. Groups B2 and E were positively associated with high-pathogenicity isolates and negatively associated with low-pathogenicity isolates. In contrast, groups A and C were positively associated with apathogenic isolates, and group B1 was positively associated with low-pathogenicity isolates. Some virulence-associated genes showed positive or negative associations with specific phylogenetic groups. None of the individual techniques produced results that correlated with the in vivo pathogenicity index. However, the combination of two techniques, namely, detection of virulence-associated genes and the phylogenetic groups, could help the classification of the isolates as pathogenic or commensal.

Probing water mobility in confining channels of reverse wormlike micelles.

Reverse wormlike micelles are a potential template for chemical reactions in confined environments. Here, we use time-domain NMR to demonstrate the solvent effect on the mobility of water molecules. The higher the cohesive energy of alkanes, the lower the water mobility, and the less viscous the solution.

Assessment of muscle mass using chest computed tomography-based quantitative and qualitative measurements in patients with systemic sclerosis: A retrospective study with cross-sectional and longitudinal analyses.

BACKGROUND/ PURPOSE: Sarcopenia has been increasingly studied in systemic sclerosis (SSc), which is one of the most lethal autoimmune diseases, mainly due to lung involvement. Our objective was to study the associations of myopenia and/or myosteatosis with clinical features of SSc and subsequent adverse outcomes. METHODS: This is a retrospective study with cross-sectional and longitudinal analyses, in which patients with SSc were consecutively included in the outpatient clinic of a tertiary university hospital between 2012 and 2021. Clinical and laboratory parameters of patients with SSc were collected from their medical records. Skeletal muscle mass was assessed on chest computed tomography (CT) at the level of the first lumbar vertebra (L1) by skeletal muscle area (SMA), skeletal muscle index ([SMI] SMA/height2), and skeletal muscle radiation attenuation (SMRA). Cut-off values for myopenia in women and men were SMA <70.1 cm² and <110.4 cm², and SMI <25.9 cm²/m² and <34.6 cm²/m², respectively; values for myosteatosis in women and men were SMRA <29.8 HU and <36.3 HU, respectively. In a subgroup of 31 patients followed-up between 2017 and 2019, the diagnostic properties of SMA, SMI, and SMRA by CT were compared with the appendicular skeletal muscle mass index (ASMI) by dual-energy X-ray absorptiometry (DXA). Low muscle quantity was defined according to the European Working Group on Sarcopenia in Older People 2: ASMI <5.5 kg/m2 in women and <7.0 kg/m2 in men. Afterwards, a better tomographic index was used for correlating with clinical and laboratory parameters. RESULTS: Myopenia and/or myosteatosis were present in 75.7 % of patients with SSc. The prevalence rates according to each index were SMA 25.2%, SMI 12.1%, and SMRA 69.2%. In 73% of the patients with overweight/obesity (body mass index [BMI] ≥25 kg/m²), only SMRA was reduced. Considering ASMI as the gold standard, the sensitivity, specificity, positive and negative predictive values for SMA were 60%, 96.2%, 75% and 92.6%, respectively; for SMI, they were 40%, 96.2%, 66.7%, and 89.3%, respectively; for SMRA, these values were 60%, 34.6%, 15%, and 81.8%. Pearson's correlation coefficients were 0.73, 0.74, and 0.10 for SMA, SMI, and SMRA, respectively, and ASMI significantly agreed with SMA (kappa 0.611, p < 0.001) and SMI (kappa 0.431, p = 0.012). After adjustments in a multivariate model, BMI (p < 0.001) and female sex (p < 0.001) remained significantly associated with myopenia by SMA; BMI (p =0.010) remained significantly associated with low muscle mass by ASMI. CONCLUSION: The SMA index at L1 level on chest CT was demonstrated to be an accurate measure that is useful for detecting myopenia in patients with SSc. BMI and male sex predicted low SMA and BMI was associated with low ASMI on DXA. STATEMENT OF CLINICAL SIGNIFICANCE: In recent years, great advances have been made in sarcopenia-related research, resulting in broader knowledge on its definition, causes, diagnosis, and treatment options. Regarding the techniques used for assessing muscle composition, computed tomography (CT) was demonstrated by many studies to be an efficient and easy-to-use method that can be employed by professionals of different specialties, including rheumatologists. This study was able to demonstrate that although the L3 image was not present on CT, the analysis of SMA at the L1 level on chest CT proved to be an accurate and useful measure to detect myopenia in patients with SSc. This study identified some associated factors of myopenia and/or myosteatosis according to each method employed for assessing muscle composition. Reduced BMI and male sex were associated factors of myopenia when using SMA, and reduced BMI was associated with myopenia when employing ASMI by DXA. Finally, we highlight the need not to generalize the term "sarcopenia" in clinical studies assessing imaging parameters of body composition. The use of the terms myopenia and/or myosteatosis would be more adequate, because CT allows the assessment of muscle composition and not strength or physical performance.

Detection of human Mastadenovirus C in wild guinea pigs (Cavia aperea aperea) feces.

The Adenoviridae family is composed by a high diversity of viruses that are extremely resistant in environment and are frequently excreted in animal reservoir feces for long periods. The knowledge of adenovirus (AdV) diversity among wild species may be important for the understanding of the epidemiology of putative emerging diseases. Cavia aperea aperea, commonly known as wild guinea pigs, wild cavies, or preas, are small herbivorous rodents widely distributed throughout South America and classified in Caviidae family, as well as domestic guinea pigs and capybaras. In order to investigate their potential role as reservoir of zoonotic agents, the present study aimed to verify the presence of AdV in fecal samples of 14 preas from Northeast Brazil. When submitted to nested PCR, two out of 14 samples (14.28%) were positive for AdV and classified as human Mastadenovirus C (HAdV-C) using DNA sequencing and phylogenetic analysis. Wild guinea pigs are synanthropic rodents that live in close contact with humans. The investigation of viral agents in rodents is important due to their potential role as reservoirs of human and animal pathogens. Moreover, the present work presents the first known evidence of HAdV in wild guinea pig stool samples, which may represent both the impact of anthropogenic pollution to wild animals and an important knowledge in terms of human health.

Avian pathogenic Escherichia coli (APEC) and uropathogenic Escherichia coli (UPEC): characterization and comparison.

INTRODUCTION: Avian pathogenic E. coli (APEC) and uropathogenic E. coli (UPEC) are responsible for avian colibacillosis and human urinary tract infections, respectively. There are genetic similarities between the APEC and UPEC pathotypes, suggesting the APEC strains could be a potential reservoir of virulence and antimicrobial-resistance genes for the UPEC strains. This study aimed to characterize and compare APEC and UPEC strains regarding the phylogroup classification, pathogenicity and antimicrobial susceptibility. METHODOLOGY: A total of 238 APEC and 184 UPEC strains were selected and characterized. The strains were assayed for antimicrobial susceptibility and classified into phylogenetic groups using a multiplex-PCR protocol. In addition, the APEC strains had previously been classified according to their in vivo pathogenicity. RESULTS: The results showed that both pathotypes had variation in their susceptibility to most of the antimicrobial agents evaluated, with few strains classified as multidrug resistant. The highest resistance rate for both pathotypes was to amoxicillin. Classifying the APEC and UPEC strains into phylogenetic groups determined that the most frequently frequencies were for groups D and B2, respectively. These results reflect the pathogenic potential of these strains, as all the UPEC strains were isolated from unhealthy patients, and most of the APEC strains were previously classified as pathogenic. CONCLUSIONS: The results indicate that distribution into phylogenetic groups provided, in part, similar classification to those of in vivo pathogenicity index, as it was possible to adequately differentiate most of the pathogenic and commensal or low-pathogenicity bacteria. However, no relationship could be found between the specific antimicrobial agents and pathogenicity or phylogenetic group for either pathotype.