Investigating the mechanisms of secretion of the moonlighting proteins Enolase and Fructose-1, 6-Bisphosphate Aldolase in Neisseria meningitidis

Neisseria meningitidis is an obligate commensal of humans that mainly colonises the nasopharynx. It is also an important cause of serious diseases, such as meningitis and sepsis. N. meningitidis uses several secretion systems (type I, type Va, type Vb, and type Vc) for secreting proteins, which enable the bacteria to modulate their cell surface and evade the human immune system. The moonlighting proteins fructose bis-1, 6-phosphate aldolase (FBA) and enolase were previously shown to localise to the surface of N. meningitidis. The mechanisms of secretion of both proteins were investigated in this study. Specifically, lysine residue 337 of enolase was substituted to investigate its role in secretion since in Escherichia coli mutation of the corresponding residue has been reported to decrease export efficiency. This study proposes that K337E substitution in meningococcal enolase causes a growth defect confirming an important functional role of this residue. However, its role in the localisation of the protein to the meningococcal cell surface is still not confirmed despite the several attempts to enhance enolase expression. The alanine residue 14 in the predicted cleavage site of the N-terminal region of FBA was substituted to investigate the role of the putative signal peptide in the surface localisation. Immunoblot analysis showed a reduction in FBA expression compared to the MC58ΔcbbA cbbAEct. Sub-cellular fractionation suggested that this mutation affected protein expression rather than its localisation to the meningococcal cell surface

Presence of BlaPER-1 and BlaVEB-1 Beta-Lactamase Genes among Isolates of Pseudomonas Aeruginosa from Burn and Trauma Hospital Peshawar, Pakistan

Pseudomonas aeruginosa spp are the most prevalent bacteria that cause nosocomial infections in hospitals. Most antibiotics, including novel new β-lactams, are already resistant to them, and they can become resistant during treatment, which can make the treatment fail. P. aeruginosa isolates from ICU patients who had Per-1 and VEB-1 were the main focus of this study. These two ESBLs are the two most common in ICU patients who had them. 50 isolates were gathered from Peshawar\u27s LRH ICU facilities in the year 2021. The antibiotic susceptibility test was conducted in accordance with the Clinical and Laboratory Standards Institute\u27s standards (CLSI). The combination disc test used to identify isolates that produce ESBLs. Ceftazidime MIC was determined using the agar dilution method using particular primers, the PER-1 and VEB-1 genes were detected using polymerase chain reaction (PCR). Fifty-six percent patients (n=40) male, whereas forty percent (n=25) were female. Augmentin (96.6%, n=61) and cefpodoxim (86.7%, n=55) resistance was found in the majority of ICU isolates. Fifty isolates (77%) tested positive for ESBL, with 94 percent (n=47) carrying the PER-1 gene and VEB-1 gene 52 percent (n=26). Ten isolates had blaPER1 and blaVEB1 present at the same time, and seven of them amplified all three genes. ESBL producers were found in a large number of ICU P. aeruginosa isolates. Although blaVEB1 and blaPER1 were found in a small number of isolates, their frequency was very high. Furthermore, carbapenem resistance was negligible. Because of drug-resistant P. aeruginosa isolates, it is vital to monitor ICU centers

Rise in carriage of group W meningococci in university students in United Kingdom

MenACWY conjugate vaccination was recently introduced in the UK for adolescents and 24 young adults to reduce disease due to Neisseria meningitidis group W (MenW). We 25 conducted a cross-sectional carriage study in first year university students. Despite 71% 26 MenACWY vaccine coverage, carriage of MenW, but not MenY, rose significantly in 27 students

Tenacibaculosis caused by Tenacibaculum maritimum: Updated knowledge of this marine bacterial fish pathogen

Tenacibaculosis occurs due to the marine bacterial pathogen Tenacibaculum maritimum. This ulcerative disease causes high mortalities for various marine fish species worldwide. Several external clinical signs can arise, including mouth erosion, epidermal ulcers, fin necrosis, and tail rot. Research in the last 15 years has advanced knowledge on the traits and pathogenesis mechanisms of T. maritimum. Consequently, significant progress has been made in defining the complex host-pathogen relationship. Nevertheless, tenacibaculosis pathogenesis is not yet fully understood. Continued research is urgently needed, as demonstrated by recent reports on the re-emerging nature of tenacibaculosis in salmon farms globally. Current sanitary conditions compromise the development of effective alternatives to antibiotics, in addition to hindering potential preventive measures against tenacibaculosis. The present review compiles knowledge of T. maritimum reported after the 2006 review by Avendaño-Herrera and colleagues. Essential aspects are emphasized, including antigenic and genomic characterizations and molecular diagnostic procedures. Further summarized are the epidemiological foundations of the T. maritimum population structure and elucidations as to the virulence mechanisms of pathogenic isolates, as found using biological, microbiological, and genomic techniques. This comprehensive source of reference will undoubtable serve in tenacibaculosis prevention and control within the marine fish farming industry. Lastly, knowledge gaps and valuable research areas are indicated as potential guidance for future studies

Investigating the mechanisms of secretion of the moonlighting proteins Enolase and Fructose-1, 6-Bisphosphate Aldolase in Neisseria meningitidis

Neisseria meningitidis is an obligate commensal of humans that mainly colonises the nasopharynx. It is also an important cause of serious diseases, such as meningitis and sepsis. N. meningitidis uses several secretion systems (type I, type Va, type Vb, and type Vc) for secreting proteins, which enable the bacteria to modulate their cell surface and evade the human immune system. The moonlighting proteins fructose bis-1, 6-phosphate aldolase (FBA) and enolase were previously shown to localise to the surface of N. meningitidis. The mechanisms of secretion of both proteins were investigated in this study. Specifically, lysine residue 337 of enolase was substituted to investigate its role in secretion since in Escherichia coli mutation of the corresponding residue has been reported to decrease export efficiency. This study proposes that K337E substitution in meningococcal enolase causes a growth defect confirming an important functional role of this residue. However, its role in the localisation of the protein to the meningococcal cell surface is still not confirmed despite the several attempts to enhance enolase expression. The alanine residue 14 in the predicted cleavage site of the N-terminal region of FBA was substituted to investigate the role of the putative signal peptide in the surface localisation. Immunoblot analysis showed a reduction in FBA expression compared to the MC58ΔcbbA cbbAEct. Sub-cellular fractionation suggested that this mutation affected protein expression rather than its localisation to the meningococcal cell surface

Facile, polyherbal drug-mediated green synthesis of CuO nanoparticles and their potent biological applications

Copper oxide nanoparticles (CuO NPs) were synthesized using ayurvedic medicine septilin. The septilin-mediated CuO NPs were characterized using UV–Vis, fourier-transform infrared spectroscopy, X-ray diffraction (XRD), scanning electron microscope (SEM), and transmission electron microscope (TEM). The average particle size of CuO NPs was 8 nm as evident from TEM. Minimum inhibitory concentration of CuO NPs against Escherichia coli, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), and Candida albicans was found in the range of 1–2.5 mg·mL−1. CuO NPs dose-dependently decreased the biofilm formation from 0.0315 to 2 mg·mL−1, at the highest dose of 2 mg·mL−1 of CuO NPs; 92.91%, 79.84%, and 71.57% decrease in biofilm was observed for P. aeruginosa, MRSA, and C. albicans, respectively. Down-regulation of biofilm upon treatment with nanoparticles (NPs) was also observed by SEM analysis. SEM analysis also showed the change in morphological structure, and deformities in bacterial and fungal cells upon treatment of NPs. Furthermore, the anticancer efficacy of NPs was assessed using colon cancer (HCT-116). The 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay clearly showed the anticancer potential of NPs, as the concentration of CuO NPs increased, the number of viable cells decreased. The produced CuO NPs have promise for future investigations in many biological and therapeutic domains, including the treatment of microbial biofilm infections, as well as the inhibition of cancer cell growth

Sustainable Green Synthesis of Yttrium Oxide (Y2O3) Nanoparticles Using Lantana camara Leaf Extracts: Physicochemical Characterization, Photocatalytic Degradation, Antibacterial, and Anticancer Potency

Due to their appropriate physicochemical properties, nanoparticles are used in nanomedicine to develop drug delivery systems for anticancer therapy. In biomedical applications, metal oxide nanoparticles are used as powerful and flexible multipurpose agents. This work described a green synthesis of Y2O3 nanoparticles (NPs) using the sol-gel technique with the use of aqueous leaf extracts of Lantana camara L (LC). These nanoparticles were characterized with the aid of different methods, including UV, X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FTIR), transmitted electron microscopy (TEM), and photocatalytic degradation. Y2O3 nanoparticles showed excellent antibacterial activity against Gram-positive Bacillus subtilis and Gram-negative Escherichia coli with a 10 to 15 mm inhibitory zone. Green Y2O3 NPs were released with a 4 h lag time and 80% sustained release rate, indicating that they could be used in drug delivery. In addition, the bioavailability of green Y2O3 NPs was investigated using cell viability in cervical cancer cell lines. These green-synthesized Y2O3 NPs demonstrated photocatalytic degradation, antibacterial, and anticancer properties