The RdRp genotyping of SARS-CoV-2 isolated from patients with different clinical spectrum of COVID-19.

BACKGROUND: The evolution of SARS-CoV-2 has been observed from the very beginning of the fight against COVID-19, some mutations are indicators of potentially dangerous variants of the virus. However, there is no clear association between the genetic variants of SARS-CoV-2 and the severity of COVID-19. We aimed to analyze the genetic variability of RdRp in correlation with different courses of COVID-19. RESULTS: The prospective study included 77 samples of SARS-CoV-2 isolated from outpatients (1st degree of severity) and hospitalized patients (2nd, 3rd and 4th degree of severity). The retrospective analyses included 15,898,266 cases of SARS-CoV-2 genome sequences deposited in the GISAID repository. Single-nucleotide variants were identified based on the four sequenced amplified fragments of SARS-CoV-2. The analysis of the results was performed using appropriate statistical methods, with p < 0.05, considered statistically significant. Additionally, logistic regression analysis was performed to predict the strongest determinants of the observed relationships. The number of mutations was positively correlated with the severity of the COVID-19, and older male patients. We detected four mutations that significantly increased the risk of hospitalization of COVID-19 patients (14676C > T, 14697C > T, 15096 T > C, and 15279C > T), while the 15240C > T mutation was common among strains isolated from outpatients. The selected mutations were searched worldwide in the GISAID database, their presence was correlated with the severity of COVID-19. CONCLUSION: Identified mutations have the potential to be used to assess the increased risk of hospitalization in COVID-19 positive patients. Experimental studies and extensive epidemiological data are needed to investigate the association between individual mutations and the severity of COVID-19.

Comparative study of virulence potential, phylogenetic origin, CRISPR-Cas regions and drug resistance of Escherichia coli isolates from urine and other clinical materials.

Introduction: Urinary tract infections (UTI), among which the main etiological factor is uropathogenic Escherichia coli (UPEC, E. coli), remain an important issue for clinicians. The aim of the study was to demonstrate clear differences in the pathogenic properties of urine-derived E. coli compared to other extraintestinal E. coli clinical isolates (derived from: blood, lower respiratory tracts, sputum, reproductive tract, body fluids, perianal pus, other pus, wound, postoperative wound and other sources). Methods: The collection of 784 E. coli isolates was collected from various materials of hospitalized patients. They were analyzed in terms of virulence-associated genes (papC, sfaD/sfaE, cnf1, usp., fimG/H, hlyA), belonging to phylogenetic groups and the presence of CRISPR-Cas regions using PCR. In addition, the epidemiological data and the antibiotic resistance profiles provided by the hospital's microbiology department were included for statistical analyses. Results: Urine-derived E. coli showed significantly greater virulence potential compared to other isolates, but they were generally unremarkable in terms of drug resistance. The isolates most often belonged to phylogenetic group B2. Drug resistance was negatively correlated with CRISPR 2 presence and high average virulence score, but positively correlated with CRISPR 4 presence. To the best of our knowledge, we are the first to report significant differences in sputum-derived isolates-they revealed the lowest virulence potential and, at the same time, the highest drug resistance. Discussion: In conclusion, we demonstrated significant differences of urinary-derived E. coli compared to other clinical E. coli isolates. We would like to suggest excluding penicillins from use in E. coli infection at this time and monitoring strains with a high pathogenicity potential.

Bacterial Motility and Its Role in Skin and Wound Infections.

Skin and wound infections are serious medical problems, and the diversity of bacteria makes such infections difficult to treat. Bacteria possess many virulence factors, among which motility plays a key role in skin infections. This feature allows for movement over the skin surface and relocation into the wound. The aim of this paper is to review the type of bacterial movement and to indicate the underlying mechanisms than can serve as a target for developing or modifying antibacterial therapies applied in wound infection treatment. Five types of bacterial movement are distinguished: appendage-dependent (swimming, swarming, and twitching) and appendage-independent (gliding and sliding). All of them allow bacteria to relocate and aid bacteria during infection. Swimming motility allows bacteria to spread from 'persister cells' in biofilm microcolonies and colonise other tissues. Twitching motility enables bacteria to press through the tissues during infection, whereas sliding motility allows cocci (defined as non-motile) to migrate over surfaces. Bacteria during swarming display greater resistance to antimicrobials. Molecular motors generating the focal adhesion complexes in the bacterial cell leaflet generate a 'wave', which pushes bacterial cells lacking appendages, thereby enabling movement. Here, we present the five main types of bacterial motility, their molecular mechanisms, and examples of bacteria that utilise them. Bacterial migration mechanisms can be considered not only as a virulence factor but also as a target for antibacterial therapy.

Loop-Mediated Isothermal Amplification of DNA (LAMP) as an Alternative Method for Determining Bacteria in Wound Infections.

The increasing number of patients with chronic wounds requires the development of quick and accurate diagnostics methods. One of the key and challenging aspects of treating ulcers is to control wound infection. Early detection of infection is essential for the application of suitable treatment methods, such as systemic antibiotics or other antimicrobial agents. Clinically, the most frequently used method for detecting microorganisms in wounds is through a swab and culture on appropriate media. This test has major limitations, such as the long bacterial growth time and the selectivity of bacterial growth. This article presents an overview of molecular methods for detecting bacteria in wounds, including real-time polymerase chain reaction (rtPCR), quantitative polymerase chain reaction (qPCR), genotyping, next-generation sequencing (NGS), and loop-mediated isothermal amplification (LAMP). We focus on the LAMP method, which has not yet been widely used to detect bacteria in wounds, but it is an interesting alternative to conventional detection methods. LAMP does not require additional complicated equipment and provides the fastest detection time for microorganisms (approx. 30 min reaction). It also allows the use of many pairs of primers in one reaction and determination of up to 15 organisms in one sample. Isothermal amplification of DNA is currently the easiest and most economical method for microbial detection in wound infection. Direct visualization of the reaction with dyes, along with omitting DNA isolation, has increased the potential use of this method.