Three novel woody litter inhabiting fungi in Didymosphaeriaceae, Phaeoseptaceae and Synnemasporellaceae from Zhujiangyuan Nature Reserve, Yunnan Province, P.R. China.

Zhujiangyuan Nature Reserve, located in Qujing City, Yunnan Province, China, is reported with high fauna and floral diversity, while the fungal diversity of the region is poorly documented. During the summer season in 2023, decaying wood-inhabiting microfungi were collected from different microhabitats. The novel species were identified based on morphological characteristics and phylogenetic analyses (based on combined datasets of ITS, LSU, SSU, tef1-α, and rpb2 regions). Two species belong to Dothideomycetes (viz., Spegazziniazhujiangyuanensis sp. nov. and Phaeoseptumzhujiangyuanense sp. nov. in Pleosporales) while the other one resides in Sordariomycetes (Synnemasporellafanii sp. nov. in Diaporthales). The results are in conformity with the earlier studies that predicted higher fungal diversity in this region.

Machine learning assisted designing of non-fullerene electron acceptors: A quest for lower exciton binding energy.

The designing of acceptors materials for the organic solar cells is a hot topic. The normal experimental methods are tedious and expensive for large screening. Machine learning guided exploration is more suitable solution. Bagging regression, random forest regression, gradient boosting regression, and linear regression are trained to predict exciton binding energy. Breaking Retrosynthetically Interesting Chemical Substructures (BRICS) methodology has utilized for designing of new non-fullerene acceptors (NFAs). The predicted values were used to select the designed NFAs. On the selected NFAs, clustering and chemical similarity analyses are also performed. Chemical fingerprints are used for this purpose, and the synthetic accessibility score of the new NFAs is also investigated.30 NFAs have selected with low exciton binding energy values. This approach will allow for the rapid screening of NFAs for organic solar cells. Our proposed framework stands out as a valuable tool for strategically selecting the most effective NFAs for organic solar cells and offers a streamlined approach for material discovery.

Thiourea improves yield and quality traits of Brassica napus L. by upregulating the antioxidant defense system under high temperature stress.

High temperature stress influences plant growth, seed yield, and fatty acid contents by causing oxidative damage. This study investigated the potential of thiourea (TU) to mitigate oxidative stress and restoring seed oil content and quality in canola. The study thoroughly examined three main factors: (i) growth conditions-control and high temperature stress (35 °C); (ii) TU supplementation (1000 mg/L)-including variations like having no TU, water application at the seedling stage, TU application at seedling stage (BBCH Scale-39), water spray at anthesis stage, and TU application at anthesis stage (BBCH Scale-60); (iii) and two canola genotypes, 45S42 and Hiola-401, were studied separately. High temperature stress reduced growth and tissue water content, as plant height and relative water contents were decreased by 26 and 36% in 45S42 and 27 and 42% Hiola-401, respectively, resulting in a substantial decrease in seed yield per plant by 36 and 38% in 45S42 and Hiola-401. Seed oil content and quality parameters were also negatively affected by high temperature stress as seed oil content was reduced by 32 and 35% in 45S42 and Hiola-401. High-temperature stress increased the plant stress indicators like malondialdehyde, H2O2 content, and electrolyte leakage; these indicators were increased in both canola genotypes as compared to control. Interestingly, TU supplementation restored plant performance, enhancing height, relative water content, foliar chlorophyll (SPAD value), and seed yield per plant by 21, 15, 30, and 28% in 45S42; 19, 13, 26, and 21% in Hiola-401, respectively, under high temperature stress as compared to control. In addition, seed quality, seed oil content, linoleic acid, and linolenic acid were improved by 16, 14, and 22% in 45S42, and 16, 11, and 23% in Hiola-401, as compared to control. The most significant improvements in canola seed yield per plant were observed when TU was applied at the anthesis stage. Additionally, the research highlighted that canola genotype 45S42 responded better to TU applications and exhibited greater resilience against high temperature stress compared to genotype Hiola-401. This interesting study revealed that TU supplementation, particularly at the anthesis stage, improved high temperature stress tolerance, seed oil content, and fatty acid profile in two canola genotypes.

Proteome analysis, genetic characterization, and antibiotic resistance patterns of Klebsiella pneumoniae clinical isolates.

Klebsiella pneumoniae (K. pneumoniae) is a member of the ESKAPE group and is responsible for severe community and healthcare-associated infections. Certain Klebsiella species have very similar phenotypes, which presents a challenge in identifying K. pneumoniae. Multidrug-resistant K. pneumoniae is also a serious global problem that needs to be addressed. A total of 190 isolates were isolated from urine (n = 69), respiratory (n = 52), wound (n = 48) and blood (n = 21) samples collected from various hospitals in the Al-Qassim, Saudi Arabia, between March 2021 and October 2022. Our study aimed to rapidly and accurately detect K. pneumoniae using the Peptide Mass Fingerprinting (PMF) technique, confirmed by real-time PCR. Additionally, screening for antibiotic susceptibility and resistance was conducted. The primary methods for identifying K. pneumoniae isolates were culture, Gram staining, and the Vitek® 2 ID Compact system. An automated MALDI Biotyper (MBT) instrument was used for proteome identification, which was subsequently confirmed using SYBR green real-time polymerase chain reaction (real-time PCR) and microfluidic electrophoresis assays. Vitek® 2 AST-GN66 cards were utilized to evaluate the antimicrobial sensitivity of K. pneumoniae isolates. According to our results, Vitek® 2 Compact accurately identified 178 out of 190 (93.68%) K. pneumoniae isolates, while the PMF technique correctly detected 188 out of 190 (98.95%) isolates with a score value of 2.00 or higher. Principal component analysis was conducted using MBT Compass software to classify K. pneumoniae isolates based on their structure. Based on the analysis of the single peak intensities generated by MBT, the highest peak values were found at 3444, 5022, 5525, 6847, and 7537 m/z. K. pneumoniae gene testing confirmed the PMF results, with 90.53% detecting entrobactin, 70% detecting 16 S rRNA, and 32.63% detecting ferric iron uptake. The resistance of the K. pneumoniae isolates to antibiotics was as follows: 64.75% for cefazolin, 62.63% for trimethoprim/sulfamethoxazole, 59.45% for ampicillin, 58.42% for cefoxitin, 57.37% for ceftriaxone, 53.68% for cefepime, 52.11% for ampicillin-sulbactam, 50.53% for ceftazidime, 52.11% for ertapenem, and 49.47% for imipenem. Based on the results of the double-disk synergy test, 93 out of 190 (48.95%) K. pneumoniae isolates were extended-spectrum beta-lactamase. In conclusion, PMF is a powerful analytical technique used to identify K. pneumoniae isolates from clinical samples based on their proteomic characteristics. K. pneumoniae isolates have shown increasing resistance to antibiotics from different classes, including carbapenem, which poses a significant threat to human health as these infections may become difficult to treat.

Comparative mineral and biochemical characterization of Citrus reticulata fruits and leaves to citrus canker pathogens, Xanthomonas axonopodis.

Pakistan's economy greatly benefits from citrus production since these fruits are sold and consumed all over the world. Although citrus fruits are easy to cultivate, they are susceptible to diseases caused by bacteria, viruses, and fungi. These challenges, as well as difficulties in obtaining the proper nutrients, might negatively impact fruit yields and quality. Citrus canker is another complicated problem caused by the germ Xanthomonas axonopodis. This germ affects many types of citrus fruits all over the world. This study looked closely at how citrus canker affects the leaves and the quality of the fruit in places like Sargodha, Bhalwal, Kotmomin, and Silanwali, which are big areas for growing citrus in the Sargodha district. What we found was that plants without the disease had more chlorophyll in their leaves compared to the sick plants. Also, the healthy plants had better amounts of important minerals like calcium, magnesium, potassium, and phosphorus in their fruits. But the fruits with the disease had too much sodium, and the iron levels were a bit different. The fruits with the disease also didn't have as much of something that protects them called antioxidants, which made them more likely to get sick. This study helps us understand how citrus canker affects plants and fruit, so we can think of ways to deal with it.

Antibiotic susceptibility of methicillin-resistant Staphylococcus aureus (MRSA) strains isolated at tertiary care hospital in Riyadh, Saudi Arabia.

Staphylococcus aureus is an important human pathogen that has a major impact on public health. The objective of the present work was to determine the prevalence and the pattern of antibiotic susceptibility in S aureus (MRSA) isolates from the King Khalid University Hospital (KKUH) in Riyadh, Saudi Arabia. The isolates were collected from different body sites of infection and the antibiotic susceptibility was confirmed on the Vitek 2 system. A total of 371 MRSA isolates from clinical samples were received over a 12-month period from January 2021 to December 2021. The results showed that infection was predominant among males (55.8%) and most of the isolates occurred in the older age groups, with a mean age of 43.7 years and an age span from <1 to 89 years old. The majority (34.5%) recovered from wound infection followed by (14.6%) from blood. We have observed peaks of MRSA infections during the autumn, especially in September and November. All MRSA isolates were resistant to Amoxicillin + clavulanic acid, Ampicillin, Imipenem, Oxacillin, Cloxacillin, and Penicillin while all isolates were sensitive to Daptomycin and Nitrofurantoin. Furthermore, Vancomycin was resistant in (0.3%) of MRSA isolates, and (2.9%) was resistant to Linezolid. The current study concluded that MRSA strains had developed resistance toward 24 tested antibiotics, including the previous effective drugs vancomycin and linezolid. Therefore, there is an urgent need for continuous review of infection control practices to prevent any further spread of resistant strains.

Investigation on the insecticidal activities of cyanobacterial extracts as an alternative source for the management of fall armyworm, Spodoptera frugiperda (J. E. Smith) (Lepidoptera: Noctuidae).

The Spodoptera frugiperda is a notorious pest with a broad host range. It severely damages crops, mainly in areas of the globewhere maize and sorghum are grown. The pest is difficult to control due to its adaptive nature and resistance to several insecticides available in the market. So, an identification of the alternative strategy is the prime important in the present context. Insecticidal activities of cyanobacterial extracts were evaluated in the laboratory as a biocomponent against S. frugiperda. The crude extracts of Nostoc muscorum and Spirulina sp. were prepared by using ethanol, methanol and petroleum ether solvents. Soxhlet apparatus was used for extraction. S. frugiperda larvae in their second instar were given access to fragments of maize leaf that had been treated with various cyanobacterial extracts. The findings displayed that the petroleum ether extract of N. muscorum had the lowest LC50 value of 155.22 ppm, followed by petroleum ether extracts of Spirulina, ethanol extract of N. Muscorum, methanol extract of N. muscorum, ethanol and methanol extract of Spirulina with an LC50 values of 456.02, 710, 780, 1050 and 1070 ppm respectively. Later, the effect of LC50 values on many biological parameters like the larval duration and pupal stages, the percentage of pupation, the weight of the pupal stage, the malformation of the pupal and adult stages, adult emergence percentage, fertility and the longevity of the male and female adult stages of S. frugiperda was examined. The gas chromatography-mass spectrometry (GC-MS) was used to analyse the crude extract to identify the bioactive components that were responsible for the insecticidal properties. The major compounds detected were diethyl phthalate (19.87 %), tetradecane (5.03%), hexadecanoic acid, ethyl ester (4.10 %), dodecane (4.03%), octadecane (3.72%), octadecanoic acid, methyl ester (3.40 %), ethyl oleate (3.11 %), methyl ester. octadecenoic acid (3.04 %), heptadecane (3.04 %) and phytol (3.02 %). The presence of several bioactive chemicals in the cyanobacterial extracts may be the reason for their insecticidal actions, thus it can be used as an alternative and new source to combat fall armyworm and other crop pests.

Enterobacter cloacae from urinary tract infections: frequency, protein analysis, and antimicrobial resistance.

The genus Enterobacter belongs to the ESKAPE group, which includes Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp. This group is characterized by the development of resistance to various antibiotics. In recent years, Enterobacter cloacae (E. cloacae) has emerged as a clinically important pathogen responsible for a wide range of healthcare-associated illnesses. Identifying Enterobacter species can be challenging due to their similar phenotypic characteristics. The emergence of multidrug-resistant E. cloacae is also a significant problem in healthcare settings. Therefore, our study aimed to identify and differentiate E. cloacae using Matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) as a fast and precise proteomic analytical technique. We also tested hospital-acquired E. cloacae isolates that produce Extended-spectrum beta-lactamases (ESBL) against commonly used antibiotics for treating urinary tract infections (UTIs). We used a total of 189 E. cloacae isolates from 2300 urine samples of patients with UTIs in our investigation. We employed culturing techniques, as well as the BD Phoenix™ automated identification system (Becton, Dickinson) and Analytical Profile Index (API) system for the biochemical identification of E. cloacae isolates. We used the MALDI Biotyper (MBT) device for peptide mass fingerprinting analysis of all isolates. We utilized the single peak intensities and Principal Component Analysis (PCA) created by MBT Compass software to discriminate and cluster the E. cloacae isolates. Additionally, we evaluated the sensitivity and resistance of ESBL-E. cloacae isolates using the Kirby Bauer method. Out of the 189 E. cloacae isolates, the BD Phoenix system correctly identified 180 (95.24%) isolates, while the API system correctly identified 165 (87.30%) isolates. However, the MBT accurately identified 185 (98.95%) isolates with a score of 2.00 or higher. PCA positively discriminated the identified E. cloacae isolates into one group, and prominent peaks were noticed between 4230 mass-to-charge ratio (m/z) and 8500 m/z. The ESBL-E. cloacae isolates exhibited a higher degree of resistance to ampicillin, amoxicillin-clavulanate, cephalothin, cefuroxime, and cefoxitin. Several isolates were susceptible to carbapenems (meropenem, imipenem, and ertapenem); however, potential future resistance against carbapenems should be taken into consideration. In conclusion, MALDI-TOF MS is a powerful and precise technology that can be routinely used to recognize and differentiate various pathogens in clinical samples. Additionally, the growing antimicrobial resistance of this bacterium may pose a significant risk to human health.

A DFT study of bandgap tuning in chloro-fluoro silicene.

The structural, electronic and optical properties of silicene and its derivatives are investigated in the present work by employing density functional theory (DFT). The Perdew-Burke-Ernzerhof generalized gradient approximation (PBE-GGA) is used as the exchange-correlation potential. Our results provide helpful insight for tailoring the band gap of silicene via functionalization of chlorine and fluorine. First, relaxation of all the materials is performed to obtain the appropriate structural parameters. Cl-Si showed the highest lattice parameter 4.31 Å value, while it also possesses the highest buckling of 0.73 Å among all the derivatives of silicene. We also study the electronic charge density, charge difference density and electrostatic potential, to check the bonding characteristics and charge transfer between Si-halides. The electronic properties, band structures and density of states (DOS) of all the materials are calculated using the PBE-GGA as well as the modified Becke-Johnson (mBJ) on PBE-GGA. Pristine silicene is found to have a negligibly small band gap but with the adsorption of chlorine and fluorine atoms, its band gap can be opened. The band gap of Cl-Si and F-Si is calculated to be 1.7 eV and 0.6 eV, respectively, while Cl-F-Si has a band gap of 1.1 eV. Moreover, the optical properties of silicene and its derivatives are explored, which includes dielectric constants ε1 and ε2, refractive indices n, extinction coefficients k, optical conductivity σ and absorption coefficients I. The calculated binding energies and phonon band structures confirm the stability of Cl-Si, Cl-F-Si, and F-Si. We also calculated the photocatalytic properties which show silicine has a good response to reduction, and the other materials to oxidation. A comparison of our current work to recent work in which graphene was functionalized with halides, is also presented and we observe that silicene is a much better alternative for graphene in terms of semiconductors and photovoltaics applications.

Comparative effectiveness of biorational pesticides for management of Phenacoccus solenopsis Tinsley and Paracoccus marginatus Williams & Granara de Willink in Gymnema sylvestre (Retz.) R.Br. ex Sm.

The cotton mealybug, Phenacoccus solenopsis Tinsley and papaya mealybug, Paracoccus marginatus Williams and Granara de Willink (Hemiptera: Pseudococcidae) are becoming major threats to the production of Gymnema sylvestre R. Br. (Asclepiadaceae) in India. Management mainly depends on chemical insecticides which cause a serious problem of pesticide residue and insecticide resistance. The use of biorational insecticides such as biopesticides, botanicals, insect growth regulators, and microbial insecticides is important components of an Integrated Pest Management (IPM) program for successful management. We evaluated the bio-efficacy of twelve biorational insecticides, including entomopathogenic fungi (EPF), using the leaf spray method in laboratory conditions at 25 ± 1 °C, 70 % ± 5 % RH. The results revealed that the highest percent mortality was recorded by acetamiprid 20 % SP (100.00 %), followed by azadirachtin (98.27 %), Lecanicillium muscarium (2 × 109 spores/mL) (85.70 %) and Ocimum sanctum leaf extract (76.87 %) at 120 h after treatment (HAT) in P. solenopsis. In P. marginatus, 100.00 %, 96.39 % and 85.67 % and 74.90 % mortalities were achieved by acetamiprid 20 % SP, azadirachtin, L. muscarium (2 × 109 spores/mL) and O. sanctum leaf extract, respectively, at 120 HAT during the first spray. Various biorational insecticides showed a more or less similar trend of percent mortality in both species during the second spray. In both species, the lowest percent mortality was recorded by Andrographis paniculata leaf extract (46.29, 44.54) and (41.03, 46.39) at 120 Hours after treatment in the first and second spray, respectively. It was concluded that all the prescribed treatments are more effective than the control. Overall, azadirachtin recorded the highest percent mortality after acetamiprid and had the shortest LT50 (12.52 h) and (13.87 h) values in P. solenopsis and P. marginatus, respectively. Our study emphasizes that biopesticides like Azadirachtin 1 % EC (10000 ppm), L. muscarium (2 × 109 spores/mL) (5 mL/L) and O. sanctum leaf extract (5 %) may be recommended as alternatives to synthetic insecticides. Botanicals and EPF would be the most effective approach for sustainable integrated management of P. solenopsis and P. marginatus in the G. sylvestre ecosystem.

Enhancing Wheat Crop Resilience to Drought Stress through Cellulolytic Microbe-Enriched Cow Dung Vermicompost.

BACKGROUND: Wheat, an important cereal crop, is commonly cultivated in arid and semiarid areas, and therefore, it often experiences water deficit conditions. The consequences of induced stress on wheat can be mitigated through vermicompost amendments. To address drought stress on wheat seedlings, a pot experiment was conducted in the wire-house in which two contrasting wheat cultivars, Faisalabad-08 (drought-tolerant) and Galaxy-13 (drought-sensitive), were exposed to three water level conditions: well-watered [D0, 70% of field capacity (FC)], moderate drought (D1, 45% FC), and severe drought (D2, 30% FC). Four rates of vermicompost, derived from cow dung enriched with cellulolytic microbes, were applied (VT0, control; VT1, 4 t ha-1; VT2, 6 t ha-1; and VT3, 8 t ha-1) to the experiment. Data on various physiological, biochemical, and enzymatic antioxidants were recorded. RESULTS: Our results demonstrated that the drought treatments significantly reduced nutrient accumulation, chlorophyll and SPAD values, and carotenoid content in both cultivars where the maximum reduction was recorded for severe drought stress. Nonetheless, the application of vermicompost significantly improved these traits, and statistically maximum chlorophyll contents, SPAD value, and total carotenoid contents were observed for VT1 in both cultivars under drought treatments. While the lowest chlorophyll and carotenoid contents were recorded for untreated replicated pots. Among the cultivars, Faisalabad-08 exhibited greater resistance to drought, as evidenced by higher values of the aforementioned traits compared to Galaxy-13. Soil-applied vermicompost also showed a positive influence on antioxidant enzyme activities in both wheat cultivars grown under well-watered as well as water-scarce conditions. CONCLUSIONS: The findings of this study revealed that drought conditions substantially decreased the enzymatic antioxidants and physiological and biochemical attributes of the wheat crop. However, soil-applied vermicompost, particularly at an optimum rate, had a positive impact on the wheat seedlings under drought conditions. Moving forward, exploring the potential of utilizing cellulolytic microbe-enriched cow dung vermicompost stands as a promising avenue to mitigate the detrimental effects of water stress on wheat. Further research in this direction could offer substantial insights into enhancing wheat resilience and productivity under water stress conditions.

Exploitation of various physio-morphological and biochemical traits for the identification of drought tolerant genotypes in cotton.

BACKGROUND: Drought is one of the limiting factors for quality and quantity of cotton lint in tropical and sub-tropical regions. Therefore, development of drought tolerant cotton genotypes have become indispensable. The identification of drought tolerant genotypes is pre-requisite to develop high yielding cultivars suitable for drought affected areas. METHODS: Forty upland cotton accessions were selected on the basis of their adaptability and yield. The collected germplasm accessions were evaluated at seedling stage on the basis of morphological, physiological and biochemical parameters. The experiment was conducted under controlled conditions in greenhouse where these genotypes were sown under different levels of drought stress by following factorial under completely randomized design. The data were collected at seedling stages for root and shoot lengths, relative leaf water content, excised leaf water losses, peroxidase content and hydrogen peroxide concentrations in leaf tissues. RESULTS: The biometrical analysis revealed that germplasm is significantly varied for recorded parameters, likewise interaction of genotypes and water stress was also significantly varied. The cotton germplasm was categorized in eight clusters based on response to water stress. The genotype Cyto-124 exhibited lowest H2O2 content under drought conditions, minimum excised leaf water loss under stress environment was exhibited by genotypes Ali Akber-802 and CEMB-33. Overall, on the basis of morphological and biochemical traits, SL-516 and Cyto-305 were found to be drought tolerant. Genotypes 1852 - 511, Stoneville 15-17 and Delta Pine-55 showed low values for root length, peroxidase activity and higher value for H2O2 contents. On the basis of these finding, these genotypes were declared as drought susceptible. CONCLUSION: The categorization of cotton germplasm indicating the differential response of various parameters under the control and drought stress conditions. The recorded parameters particularly relative leaf water contents and biochemical assays could be utilized to screen large number of germplasm of cotton for water deficit conditions. Besides, the drought tolerant genotypes identified in this research can be utilized in cotton breeding programs for the development of improved cultivars.

Teicoplanin associated gene tcaA inactivation increases persister cell formation in Staphylococcus aureus.

Staphylococcus aureus is part of normal human flora and is widely associated with hospital-acquired bacteremia. S. aureus has shown a diverse array of resistance to environmental stresses and antibiotics. Methicillin-resistant S. aureus (MRSA) is on the high priority list of new antibiotics discovery and glycopeptides are considered the last drug of choice against MRSA. S. aureus has developed resistance against glycopeptides and the emergence of vancomycin-intermediate-resistant, vancomycin-resistant, and teicoplanin-resistant strains is globally reported. Teicoplanin-associated genes tcaR-tcaA-tcaB (tcaRAB) is known as the S. aureus glycopeptide resistance operon that is associated with glycopeptide resistance. Here, for the first time, the role of tcaRAB in S. aureus persister cells formation, and ΔtcaA dependent persisters' ability to resuscitate the bacterial population was explored. We recovered a clinical strain of MRSA from a COVID-19 patient which showed a high level of resistance to teicoplanin, vancomycin, and methicillin. Whole genome RNA sequencing revealed that the tcaRAB operon expression was altered followed by high expression of glyS and sgtB. The RNA-seq data revealed a significant decrease in tcaA (p = 0.008) and tcaB (p = 0.04) expression while tcaR was not significantly altered. We knocked down tcaA, tcaB, and tcaR using CRISPR-dCas9 and the results showed that when tcaA was suppressed by dCas9, a significant increase was witnessed in persister cells while tcaB suppression did not induce persistence. The results were further evaluated by creating a tcaA mutant that showed ΔtcaA formed a significant increase in persisters in comparison to the wild type. Based on our findings, we concluded that tcaA is the gene that increases persister cells and glycopeptide resistance and could be a potential therapeutic target in S. aureus.

Using Protein Fingerprinting for Identifying and Discriminating Methicillin Resistant Staphylococcus aureus Isolates from Inpatient and Outpatient Clinics.

In hospitals and other clinical settings, Methicillin-resistant Staphylococcus aureus (MRSA) is a particularly dangerous pathogen that can cause serious or even fatal infections. Thus, the detection and differentiation of MRSA has become an urgent matter in order to provide appropriate treatment and timely intervention in infection control. To ensure this, laboratories must have access to the most up-to-date testing methods and technology available. This study was conducted to determine whether protein fingerprinting technology could be used to identify and distinguish MRSA recovered from both inpatients and outpatients. A total of 326 S. aureus isolates were obtained from 2800 in- and outpatient samples collected from King Faisal Specialist Hospital and Research Centre in Riyadh, Saudi Arabia, from October 2018 to March 2021. For the phenotypic identification of 326 probable S. aureus cultures, microscopic analysis, Gram staining, a tube coagulase test, a Staph ID 32 API system, and a Vitek 2 Compact system were used. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS), referred to as protein fingerprinting, was performed on each bacterial isolate to determine its proteomic composition. As part of the analysis, Principal Component Analysis (PCA) and a single-peak analysis of MALDI-TOF MS software were also used to distinguish between Methicillin-sensitive Staphylococcus aureus (MSSA) and MRSA. According to the results, S. aureus isolates constituted 326 out of 2800 (11.64%) based on the culture technique. The Staph ID 32 API system and Vitek 2 Compact System were able to correctly identify 262 (80.7%) and 281 (86.2%) S. aureus strains, respectively. Based on the Oxacillin Disc Diffusion Method, 197 (62.23%) of 326 isolates of S. aureus exhibited a cefoxitin inhibition zone of less than 21 mm and an oxacillin inhibition zone of less than 10 mm, and were classified as MRSA under Clinical Laboratory Standards Institute guidelines. MALDI-TOF MS was able to correctly identify 100% of all S. aureus isolates with a score value equal to or greater than 2.00. In addition, a close relationship was found between S. aureus isolates and higher peak intensities in the mass ranges of 3990 Da, 4120 Da, and 5850 Da, which were found in MRSA isolates but absent in MSSA isolates. Therefore, protein fingerprinting has the potential to be used in clinical settings to rapidly detect and differentiate MRSA isolates, allowing for more targeted treatments and improved patient outcomes.

The functional repertoire of AmpR in the AmpC ß-lactamase high expression and decreasing ß-lactam and aminoglycosides resistance in ESBL Citrobacter freundii.

Citrobacter freundii is characterized by AmpC ß-lactamases that develop resistance to ß-lactam antibiotics. The production of extended-spectrum ß-lactamase (ESBL) is substantially high in Escherichia coli, C. freundii, Enterobacter cloacae, and Serratia marcescens, but infrequently explored in C. freundii. The present investigation characterized the ESBL C. freundii and delineated the genes involved in decrease in antibiotics resistance. We used the VITEK-2 system and Analytical Profile Index (API) kit to characterize and identify the Citrobacter isolates. The mRNA level of AmpC and AmpR was determined by RT-qPCR, and gel-shift assay was performed to evaluate protein-DNA binding. Here, a total of 26 Citrobacter strains were isolated from COVID-19 patients that showed varying degrees of antibiotic resistance. We examined and characterized the multidrug resistant C. freundii that showed ESBL production. The RT-qPCR analysis revealed that the AmpC mRNA expression is significantly high followed by a high level of AmpR. We sequenced the AmpC and AmpR genes that revealed the AmpR has four novel mutations in comparison to the reference genome namely; Thr64Ile, Arg86Ser, Asp135Val, and Ile183Leu while AmpC remained intact. The ΔAmpR mutant analysis revealed that the AmpR positively regulates oxidative stress response and decreases ß-lactam and aminoglycosides resistance. The AmpC and AmpR high expression was associated with resistance to tazobactam, ampicillin, gentamicin, nitrofurantoin, and cephalosporins whereas AmpR deletion reduced ß-lactam and aminoglycosides resistance. We conclude that AmpR is a positive regulator of AmpC that stimulates ß-lactamases which inactivate multiple antibiotics.

Performance prediction of polymer-fullerene organic solar cells and data mining-assisted designing of new polymers.

CONTEXT: Selecting high performance polymer materials for organic solar cells (OSCs) remains a compelling goal to improve device morphology, stability, and efficiency. To achieve these goals, machine learning has been reported as a powerful set of algorithms/techniques to solve complex problems and help/guide exploratory researchers to screen, map, and develop high performance materials. In present work, we have applied machine learning tools to screen data from reported studies and designed new polymer acceptor materials, respectively. Quantitative structure-activity relationship (QSAR) models were generated using machine learning-assisted simulation techniques. For this purpose, 3000 molecular descriptors are generated. Consequently, molecular descriptors having key effect on power conversion efficiency (PCE) were identified. Moreover, numerous regression models (e.g., random forest and bagging regressor models) were developed to predict the PCE. In particular, new materials were designed based on the similarity analysis. The GDB17 chemical database consisting of 166 million organic molecules in an ordered form is used for performing similarity analysis. A similarity behavior between GDB17 materials and the materials reported in literature is studied using RDKit (a cheminformatics software). Noteworthily, 100 monomers proved to be unique and effective, and PCEs of these monomers are predicted. Among these monomers, four monomers exhibited PCE higher than 14%, which is better than various reported studies. Our methodology provides a unique, time- and cost-efficient approach to screening and designing new polymers for OSCs using similarity analysis without revisiting the reported studies. METHODS: To perform machine learning analysis, data from reported studies and online databases was collected. Different molecular descriptors were generated for polymer materials utilizing Dragon software. 3D structures of studied molecules were applied as input (SDF; structure data file format). Importantly, about 3000 molecular descriptors were generated. Comma-separated value (.csv) file format was used to export these molecular descriptors. To shortlist best descriptors, univariate regression analysis was performed. These descriptors were further utilized for training machine learning models. Moreover, necessary packages of Python for data analysis and visualization were imported such as Matplotlib, Numpy, Pandas, Scikit-learn, Seaborn, and Scipy. Random forest and bagging regressor models were applied for performing machine learning analysis. A cheminformatics software, RDKit, was applied for similarity analysis.

The Prevalence of Multidrug-Resistant Acinetobacter baumannii and Its Vaccination Status among Healthcare Providers.

There is growing concern among healthcare providers worldwide regarding the prevalence of multidrug-resistant Acinetobacter baumannii (A. baumannii). Some of the worst hospital-acquired infections, often in intensive care units (ICUs), are caused by this bacterial pathogen. In recent years, the rise in multidrug-resistant A. baumannii has been linked to the overuse of antimicrobial drugs and the lack of adequate infection control measures. Infections caused by this bacterial pathogen are the result of prolonged hospitalization and ICU stays, and they are associated with increased morbidity and mortality. This review outlines the epidemiology, risk factors, and antimicrobial resistance associated with A. baumannii in various countries, with a special focus on the Kingdom of Saudi Arabia. In response to the growing concern regarding this drug-resistant bacteria, fundamental information about its pathology has been incorporated into the development of vaccines. Although these vaccines have been successful in animal models, their effectiveness in humans remains unproven. The review will discuss the development of A. baumannii vaccines, potential related obstacles, and efforts to find an effective strategy against this pathogen.

Green Synthesised TiO2 Nanoparticles-Mediated Terenna asiatica: Evaluation of Their Role in Reducing Oxidative Stress, Inflammation and Human Breast Cancer Proliferation.

Oxidative stress and chronic inflammation interplay with the pathogenesis of cancer. Breast cancer in women is the burning issue of this century, despite chemotherapy and magnetic therapy. The management of secondary complications triggered by post-chemotherapy poses a great challenge. Thus, identifying target-specific drugs with anticancer potential without secondary complications is a challenging task for the scientific community. It is possible that green technology has been employed in a greater way in order to fabricate nanoparticles by amalgamating plants with medicinal potential with metal oxide nanoparticles that impart high therapeutic properties with the least toxicity. Thus, the present study describes the synthesis of Titanium dioxide nanoparticles (TiO2 NPs) using aqueous Terenna asiatica fruit extract, with its antioxidant, anti-inflammatory and anticancer properties. The characterisation of TiO2 NPs was carried out using a powdered X-ray diffractometer (XRD), Fourier transform infrared (FTIR), scanning electron microscopy (SEM), energy-dispersive X-ray diffraction (EDX), high-resolution transmission electron microscopy (HR-TEM), dynamic light scattering (DLS), and zeta-potential. TiO2 NPs showed their antioxidant property by scavenging 1,1-diphenyl-2-picrylhydrazyl (DPPH) free radicals in a dose-dependent manner with an IC50 value of 80.21 µg/µL. To ascertain the observed antioxidant potential of TiO2 NPs, red blood cells (RBC) were used as an in vitro model system. Interestingly, TiO2 NPs significantly ameliorated all the stress parameters, such as lipid peroxidation (LPO), protein carbonyl content (PCC), total thiol (TT), superoxide dismutase (SOD), and catalase (CAT) in sodium nitrite (NaNO2)-induced oxidative stress, in RBC. Furthermore, TiO2 NPs inhibited RBC membrane lysis and the denaturation of both egg and bovine serum albumin, significantly in a dose-dependent manner, suggesting its anti-inflammatory property. Interestingly, TiO2 NPs were found to kill the MCF-7 cells as a significant decrease in cell viability of the MCF-7 cell lines was observed. The percentage of growth inhibition of the MCF-7 cells was compared to that of untreated cells at various doses (12.5, 25, 50, 100, and 200 µg/mL). The IC50 value of TiO2 NPs was found to be (120 µg/mL). Furthermore, the Annexin V/PI staining test was carried out to confirm apoptosis. The assay indicated apoptosis in cancer cells after 24 h of exposure to TiO2 NPs (120 µg/mL). The untreated cells showed no significant apoptosis in comparison with the standard drug doxorubicin. In conclusion, TiO2 NPs potentially ameliorate NaNO2-induced oxidative stress in RBC, inflammation and MCF-7 cells proliferation.

Antibacterial effectiveness of photo-sonodynamic treatment by methylene blue-incorporated poly(D, L-lactide-co-glycolide) acid nanoparticles to disinfect root canals.

AIM: This in-vitro investigation aimed to assess the antibacterial effectiveness of photo-sonodynamic treatment using methylene blue (MTB)-incorporated poly(D, L-Lactide-Co-Glycolide) acid (PLGA)-nanoparticles for the disinfection of root canals. METHODS: The synthesis of PLGA nanoparticles was achieved using a solvent displacement technique. The morphological and spectral characterization of the formulated PLGA nanoparticles were carried out using scanning electron microscopy (SEM) and Transformed-Fourier infrared spectroscopy (TFIR), respectively. One hundred human premolar teeth were sterilized and then their root canals were infected with Enterococcus faecalis (E. faecalis). Later, the bacterial viability evaluation of the following 5 research groups was conducted: (a) G-1: specimens treated with a diode laser; (b) G-2: specimens treated with antimicrobial photodynamic therapy (aPDT) and 50 µg/mL of MTB-incorporated PLGA nanoparticles; (c) G-3: specimens treated with ultrasound (US); (d) G-4: specimens treated with US and 50 µg/mL of MTB-incorporated PLGA nanoparticles; and (e) G-5: control group consisting of specimens that did not undergo any treatment. RESULTS: Under SEM, the nanoparticles exhibited a uniform spherical shape and were around 100 nm. The formulated nanoparticles' size was validated through zeta potential analysis utilizing dynamic light scattering (DLS). The TFIR images of both PLGA nanoparticles and MTB-incorporated PLGA nanoparticles exhibited absorption bands ranging from around 1000 to 1200/cm and nearly from 1500 to 1750/cm. The G-5 samples (control group) demonstrated the greatest viability against E. faecalis, followed by G-3 (US-conditions specimens), G-1 (diode laser-conditioned specimens), G-2 (aPDT + MTB-incorporated PLGA-nanoparticles-conditioned specimens), and G-5 (US + MTB-incorporated PLGA-nanoparticles-conditioned specimens). Significant statistical differences (p < 0.05) were observed among all research groups, including both the experimental groups and control group. CONCLUSION: The combination of US via MTB-incorporated PLGA nanoparticles exhibited the most effective eradication of E. faecalis, suggestive of a promising therapeutic modality against E. faecalis for disinfecting root canals with complex and challenging anatomy.

The adhesive strength of fiber post-to-canal dentin with Aniline green, Fotoenticine activated by PDT, green tea, and ozone as a final irrigant.

AIM: The effect of novel final disinfection protocols Malachite green (MG), Fotoenticine® (FTC), Green tea extract (GTE), and Ozonated water (OW) on the bond strength of prefabricated glass fiber posts (PGFP) adhered to canal dentin. MATERIAL AND METHOD: The canals of fifty premolars with closed apices were cleansed and obturated. The specimens were randomly assigned to one of five groups based on the final irrigant used, with the control group receiving NaOCl+EDTA and the experimental groups receiving MG, FTC, OW, and GTE. The GFP was cemented with a self-etching, dual-cure paste; the bond strength was estimated with a universal testing machine; and failure analysis was conducted with a stereomicroscope. RESULTS: The highest PBS was observed in the coronal third of Group 4 (using ozonated water as the final irrigant), whereas the lowest bond integrity was observed in the apical section of Group 2 (1.02-0.54 MPa) using Malachite green as the final irrigant. Group 1, Group 4, and Group 5 exhibited no significant difference in the bond integrity of GFP to dentin when compared to Group 2 (p>0.05). In addition, comparable bond score values were obtained for Groups 2 and 3 (p>0.05). CONCLUSION: The results of this study suggest that OW and GTE may be effective final disinfectants for root canals, as they increase the bond strength of resin-luting cement.