Activity of Epsilon-poly-L-lysine against Multidrug-Resistant Pseudomonas aeruginosa and Klebsiella pneumoniae Isolates of Urinary Tract Infections.

Pseudomonas aeruginosa and Klebsiella pneumoniae are notorious for their resistance to antibiotics and propensity for biofilm formation, posing significant threats to human health. Epsilon-poly-L-lysine (ε-PL) emerges as a naturally occurring antimicrobial poly(amino acid), which positions it as a prospective agent for addressing challenges linked to multidrug resistance. ε-PL symbolizes a promising avenue in the pursuit of efficacious therapeutic strategies and warrants earnest consideration within the realm of clinical treatment. Thus, our objective was to determine the antibiotic susceptibility profiles of 38 selected P. aeruginosa and ESBL-producing K. pneumoniae clinical isolates and determine the ability of ε-PL to inhibit biofilm formation. After PCR analysis, detection of genes related to ß-lactamases was observed among the selected isolates of P. aeruginosa [blaSPM (35.7%), blaKPC (35.7%), blaSHV (14.3%), blaCTX-M (14.3%), blaOXA (14.3%), blaTEM (7.1%), blaPER (7.1%), blaVIM (7.1%), and blaVIM-2 (7.1%)] and K. pneumoniae [blaCTX-M (91.7%), blaTEM (83.3%), blaKPC (16.7%), blaNDM (12.5%), and blaOXA (4.2%)]. The results of testing the activity of ε-PL against the clinical isolates showed relatively high minimum inhibitory concentrations (MICs) for the P. aeruginosa (range: 8-64 µg/mL) and K. pneumoniae isolates (range: 16-32 µg/mL). These results suggest the need for prior optimization of ε-PL concerning its viability as an alternative to antibiotics for treating infections caused by P. aeruginosa and K. pneumoniae of clinical origin. It is noteworthy that, in the context of a low antibiotic discovery rate, ε-PL could play a significant role in this quest, considering its low toxicity and the unlikely development of resistance. Upon exposure to ε-PL, P. aeruginosa and K. pneumoniae isolates exhibited a reduction in biofilm production, with ε-PL concentration showing an inverse relationship, particularly in isolates initially characterized as strong or moderate producers, indicating its potential as a natural antimicrobial agent with further research needed to elucidate optimal concentrations and application methods across different bacterial species. Further research is needed to optimize its use and explore its potential in various applications.

Determination of Antimicrobial Resistance and the Impact of Imipenem + Cilastatin Synergy with Tetracycline in Pseudomonas aeruginosa Isolates from Sepsis.

Pseudomonas aeruginosa is among the most ubiquitous bacteria in the natural world, exhibiting metabolic and physiological versatility, which makes it highly adaptable. Imipenem + cilastatin and tetracycline are antibiotic combinations commonly used to treat infections caused by P. aeruginosa, including serious infections such as sepsis. In the context of bacterial infections, biofilm, formed by bacterial cells surrounded by extracellular substances forming a matrix, plays a pivotal role in the resistance of P. aeruginosa to antibiotics. This study aimed to characterize a representative panel of P. aeruginosa isolates from septicemias, assessing their susceptibility to various antibiotics, specifically, imipenem + cilastatin and tetracycline, and the impact of these treatments on biofilm formation. Results from antibiotic susceptibility tests revealed sensitivity in most isolates to six antibiotics, with four showing near or equal to 100% sensitivity. However, resistance was observed in some antibiotics, albeit at minimal levels. Notably, tetracycline showed a 100% resistance phenotype, while imipenem + cilastatin predominantly displayed an intermediate phenotype (85.72%), with some resistance (38.1%). Microdilution susceptibility testing identified effective combinations against different isolates. Regarding biofilm formation, P. aeruginosa demonstrated the ability to produce biofilms. The staining of microtiter plates confirmed that specific concentrations of imipenem + cilastatin and tetracycline could inhibit biofilm production. A significant proportion of isolates exhibited resistance to aminoglycoside antibiotics because of the presence of modifying genes (aac(3)-II and aac(3)-III), reducing their effectiveness. This study also explored various resistance genes, unveiling diverse resistance mechanisms among P. aeruginosa isolates. Several virulence genes were detected, including the las quorum-sensing system genes (lasI and lasR) in a significant proportion of isolates, contributing to virulence factor activation. However, genes related to the type IV pili (T4P) system (pilB and pilA) were found in limited isolates. In conclusion, this comprehensive study sheds light on the intricate dynamics of P. aeruginosa, a remarkably adaptable bacterium with a widespread presence in the natural world. Our findings provide valuable insights into the ongoing battle against P. aeruginosa infections, highlighting the need for tailored antibiotic therapies and innovative approaches to combat biofilm-related resistance.

In Vitro Antimicrobial Studies of Mesoporous Silica Nanoparticles Comprising Anionic Ciprofloxacin Ionic Liquids and Organic Salts.

The combination of active pharmaceutical ingredients in the form of ionic liquids or organic salts (API-OSILs) with mesoporous silica nanoparticles (MSNs) as drug carriers can provide a useful tool in enhancing the capabilities of current antibiotics, especially against resistant strains of bacteria. In this publication, the preparation of a set of three nanomaterials based on the modification of a MSN surface with cholinium ([MSN-Chol][Cip]), 1-methylimidazolium ([MSN-1-MiM][Cip]) and 3-picolinium ([MSN-3-Pic][Cip]) ionic liquids coupled with anionic ciprofloxacin have been reported. All ionic liquids and functionalized nanomaterials were prepared through sustainable protocols, using microwave-assisted heating as an alternative to conventional methods. All materials were characterized through FTIR, solution 1H NMR, elemental analysis, XRD and N2 adsorption at 77 K. The prepared materials showed no in vitro cytotoxicity in fibroblasts viability assays. The minimum inhibitory concentration (MIC) for all materials was tested against Gram-negative K. pneumoniae and Gram-positive Enterococcus spp., both with resistant and sensitive strains. All sets of nanomaterials containing the anionic antibiotic outperformed free ciprofloxacin against resistant and sensitive forms of K. pneumoniae, with the prominent case of [MSN-Chol][Cip] suggesting a tenfold decrease in the MIC against sensitive strains. Against resistant K. pneumoniae, a five-fold decrease in the MIC was observed for all sets of nanomaterials compared with neutral ciprofloxacin. Against Enterococcus spp., only [MSN-1-MiM][Cip] was able to demonstrate a slight improvement over the free antibiotic.

Study of Antimicrobial Resistance, Biofilm Formation, and Motility of Pseudomonas aeruginosa Derived from Urine Samples.

Pseudomonas aeruginosa causes urinary tract infections associated with catheters by forming biofilms on the surface of indwelling catheters. Therefore, controlling the spread of the bacteria is crucial to preventing its transmission in hospitals and the environment. Thus, our objective was to determine the antibiotic susceptibility profiles of twenty-five P. aeruginosa isolates from UTIs at the Medical Center of Trás-os-Montes and Alto Douro (CHTMAD). Biofilm formation and motility are also virulence factors studied in this work. Out of the twenty-five P. aeruginosa isolates, 16% exhibited multidrug resistance, being resistant to at least three classes of antibiotics. However, the isolates showed a high prevalence of susceptibility to amikacin and tobramycin. Resistance to carbapenem antibiotics, essential for treating infections when other antibiotics fail, was low in this study, Notably, 92% of the isolates demonstrated intermediate sensitivity to ciprofloxacin, raising concerns about its efficacy in controlling the disease. Genotypic analysis revealed the presence of various ß-lactamase genes, with class B metallo-ß-lactamases (MBLs) being the most common. The blaNDM, blaSPM, and blaVIM-VIM2 genes were detected in 16%, 60%, and 12% of the strains, respectively. The presence of these genes highlights the emerging threat of MBL-mediated resistance. Additionally, virulence gene analysis showed varying prevalence rates among the strains. The exoU gene, associated with cytotoxicity, was found in only one isolate, while other genes such as exoS, exoA, exoY, and exoT had a high prevalence. The toxA and lasB genes were present in all isolates, whereas the lasA gene was absent. The presence of various virulence genes suggests the potential of these strains to cause severe infections. This pathogen demonstrated proficiency in producing biofilms, as 92% of the isolates were found to be capable of doing so. Currently, antibiotic resistance is one of the most serious public health problems, as options become inadequate with the continued emergence and spread of multidrug-resistant strains, combined with the high rate of biofilm production and the ease of dissemination. In conclusion, this study provides insights into the antibiotic resistance and virulence profiles of P. aeruginosa strains isolated from human urine infections, highlighting the need for continued surveillance and appropriate therapeutic approaches.

The Impact of the Virulence of Pseudomonas aeruginosa Isolated from Dogs.

Pseudomonas aeruginosa is a pathogenic bacterium that can cause serious infections in both humans and animals, including dogs. Treatment of this bacterium is challenging because some strains have developed multi-drug resistance. This study aimed to evaluate the antimicrobial resistance patterns and biofilm production of clinical isolates of P. aeruginosa obtained from dogs. The study found that resistance to various ß-lactam antimicrobials was widespread, with cefovecin and ceftiofur showing resistance in 74% and 59% of the isolates tested, respectively. Among the aminoglycosides, all strains showed susceptibility to amikacin and tobramycin, while gentamicin resistance was observed in 7% of the tested isolates. Furthermore, all isolates carried the oprD gene, which is essential in governing the entry of antibiotics into bacterial cells. The study also investigated the presence of virulence genes and found that all isolates carried exoS, exoA, exoT, exoY, aprA, algD, and plcH genes. This study compared P. aeruginosa resistance patterns worldwide, emphasizing regional understanding and responsible antibiotic use to prevent multi-drug resistance from emerging. In general, the results of this study emphasize the importance of the continued monitoring of antimicrobial resistance in veterinary medicine.

Genomic and Metabolic Characteristics of the Pathogenicity in Pseudomonas aeruginosa.

In recent years, the effectiveness of antimicrobials in the treatment of Pseudomonas aeruginosa infections has gradually decreased. This pathogen can be observed in several clinical cases, such as pneumonia, urinary tract infections, sepsis, in immunocompromised hosts, such as neutropenic cancer, burns, and AIDS patients. Furthermore, Pseudomonas aeruginosa causes diseases in both livestock and pets. The highly flexible and versatile genome of P. aeruginosa allows it to have a high rate of pathogenicity. The numerous secreted virulence factors, resulting from its numerous secretion systems, the multi-resistance to different classes of antibiotics, and the ability to produce biofilms are pathogenicity factors that cause numerous problems in the fight against P. aeruginosa infections and that must be better understood for an effective treatment. Infections by P. aeruginosa represent, therefore, a major health problem and, as resistance genes can be disseminated between the microbiotas associated with humans, animals, and the environment, this issue needs be addressed on the basis of an One Health approach. This review intends to bring together and describe in detail the molecular and metabolic pathways in P. aeruginosa's pathogenesis, to contribute for the development of a more targeted therapy against this pathogen.

The 10,000-Year Success Story of Wheat!

Wheat is one of the most important cereal crops in the world as it is used in the production of a diverse range of traditional and modern processed foods. The ancient varieties einkorn, emmer, and spelt not only played an important role as a source of food but became the ancestors of the modern varieties currently grown worldwide. Hexaploid wheat (Triticum aestivum L.) and tetraploid wheat (Triticum durum Desf.) now account for around 95% and 5% of the world production, respectively. The success of this cereal is inextricably associated with the capacity of its grain proteins, the gluten, to form a viscoelastic dough that allows the transformation of wheat flour into a wide variety of staple forms of food in the human diet. This review aims to give a holistic view of the temporal and proteogenomic evolution of wheat from its domestication to the massively produced high-yield crop of our day.

Advances in quantification and analysis of the celiac-related immunogenic potential of gluten.

Gluten-free products have emerged in response to the increasing prevalence of gluten-related disorders, namely celiac disease. Therefore, the quantification of gluten in products intended for consumption by individuals who may suffer from these pathologies must be accurate and reproducible, in a way that allows their proper labeling and protects the health of consumers. Immunochemical methods have been the methods of choice for quantifying gluten, and several kits are commercially available. Nevertheless, they still face problems such as the initial extraction of gluten in complex matrices or the use of a standardized reference material to validate the results. Lately, other methodologies relying mostly on mass spectrometry-based techniques have been explored, and that may allow, in addition to quantitative analysis, the characterizationof gluten proteins. On the other hand, although the level of 20 mg/kg of gluten detected by these methods is sufficient for a product to be considered gluten-free, its immunogenic potential for celiac patients has not been clinically validated. In this sense, in vitro and in vivo models, such as the organoid technology applied in gut-on-chip devices and the transgenic humanized mouse models, respectively, are being developed for investigating both the gluten-induced pathogenesis and the treatment of celiac disease. Due to the ubiquitous nature of gluten in the food industry, as well as the increased prevalence of gluten-related disorders, here we intend to summarize the available methods for gluten quantification in food matrices and for the evaluation of its immunogenic potential concerning the development of novel therapies for celiac disease to highlight active research and discuss knowledge gaps and current challenges in this field.

[Robin sequence: a single treatment protocol]. / Seqüência de Robin -- protocolo único de tratamento.

OBJECTIVE: To present a single protocol that might cover both the respiratory and feeding difficulties of neonates and infants with Robin sequence. SOURCES OF DATA: The article was prepared on the basis of the most recent publications available in bibliographic databases and in books that discuss the treatment of Robin sequence, especially the studies conducted at the Hospital for Rehabilitation of Craniofacial Anomalies of Universidade de São Paulo (HRAC/USP). SUMMARY OF THE FINDINGS: We present the morphological and genetic aspects of Robin sequence and concepts about nasopharyngoscopy and its clinical implications; we discuss the treatment of respiratory and feeding difficulties, and we present a single protocol for the treatment of all Robin sequence cases regardless of their severity and complexity. CONCLUSIONS: Robin sequence is not only an anatomic obstructive disorder to be treated with surgical procedures, but knowledge about children s growth and development must be applied by a multidisciplinary team, since this permits the maintenance of airway permeability and of the ability to feed orally, often without the need of surgical procedures and their risks, especially when applied to neonates and small infants.

Nasopharyngoscopy in Robin sequence: clinical and predictive value.

OBJECTIVE: To correlate nasopharyngoscopic findings with clinical manifestations during the first month of life and study the course of respiratory obstruction during the first year in infants with Robin sequence (RS). DESIGN: A longitudinal prospective study of children with RS. SETTING: Hospital de Reabilitação de Anomalias Craniofaciais, University of São Paulo, Bauru-SP, Brazil, 1998 to 2000. PATIENTS: Fifty-six children were studied from the age of 1 month to 12 months. INTERVENTIONS: The type of respiratory obstruction was defined by nasopharyngoscopy. Patients for whom glossoptosis was the only mechanism of respiratory obstruction were classified as having mild, moderate, or severe glossoptosis by nasopharyngoscopy and as mild, moderate, or severe cases with respect to the clinical manifestations. RESULTS: Forty-two (75%) patients showed respiratory obstruction caused by glossoptosis; seven (43.7%) of these infants with mild clinical manifestations showed moderate glossoptosis during the first month of life and five (31.3%) presented severe glossoptosis; 10 (45.5%) of the infants with severe clinical manifestations showed moderate and 11 (50.0%) severe glossoptosis. At 12 months of age, glossoptosis was mild or absent in 83.3% of the patients, moderate in 14.3% and severe in 2.4%. CONCLUSIONS: A poor correlation between the severity of glossoptosis and the severity of clinical manifestations was observed for patients with respiratory obstruction caused by glossoptosis during the first month of life, but the correlation between glossoptosis and respiratory distress according to age was statistically significant. Nasopharyngoscopy is not a good method for predicting the severity of the clinical course of respiratory obstruction caused by glossoptosis.