Trade-offs between antibacterial resistance and fitness cost in the production of metallo-b-lactamases by enteric bacteria manifest as sporadic emergence of carbapenem resistance in a clinical setting

Meropenem is a clinically important antibacterial reserved for treatment of multiresistant infections. In meropenem-resistant bacteria of the family Enterobacterales, NDM-1 is considerably more common than IMP-1, despite both metallo-β-lactamases (MBLs) hydrolyzing meropenem with almost identical kinetics. We show that bla(NDM-1) consistently confers meropenem resistance in wild-type Enterobacterales, but bla(IMP-1) does not. The reason is higher bla(NDM-1) expression because of its stronger promoter. However, the cost of meropenem resistance is reduced fitness of bla(NDM-1)-positive Enterobacterales. In parallel, from a clinical case, we identified multiple Enterobacter spp. isolates carrying a plasmid-encoded bla(NDM-1) having a modified promoter region. This modification lowered MBL production to a level associated with zero fitness cost, but, consequently, the isolates were not meropenem resistant. However, we identified a Klebsiella pneumoniae isolate from this same clinical case carrying the same bla(NDM-1) plasmid. This isolate was meropenem resistant despite low-level NDM-1 production because of a ramR mutation reducing envelope permeability. Overall, therefore, we show how the resistance/fitness trade-off for MBL carriage can be resolved. The result is sporadic emergence of meropenem resistance in a clinical setting

Impact of the Double Mutants on Spike Protein of SARS-CoV-2 B.1.617 Lineage on the Human ACE2 Receptor Binding: A Structural Insight

The recent emergence of novel SARS-CoV-2 variants has threatened the efforts to contain the COVID-19 pandemic. The emergence of these “variants of concern” has increased immune escape and has supplanted the ancestral strains. The novel variants harbored by the B.1.617 lineage (kappa and delta) carry mutations within the receptor-binding domain of spike (S) protein (L452R + E484Q and L452R + T478K), the region binding to the host receptor. The double mutations carried by these novel variants are primarily responsible for an upsurge number of COVID-19 cases in India. In this study, we thoroughly investigated the impact of these double mutations on the binding capability to the human host receptor. We performed several structural analyses and found that the studied double mutations increase the binding affinity of the spike protein to the human host receptor (ACE2). Furthermore, our study showed that these double mutants might be a dominant contributor enhancing the receptor-binding affinity of SARS-CoV-2 and consequently making it more stable. We also investigated the impact of these mutations on the binding affinity of two monoclonal antibodies (Abs) (2-15 and LY-CoV555) and found that the presence of the double mutations also hinders its binding with the studied Abs. The principal component analysis, free energy landscape, intermolecular interaction, and other investigations provided a deeper structural insight to better understand the molecular mechanism responsible for increased viral transmissibility of these variants

Migratory Wild Birds as a Potential Disseminator of Antimicrobial-Resistant Bacteria around Al-Asfar Lake, Eastern Saudi Arabia

Migratory wild birds acquire antimicrobial-resistant (AMR) bacteria from contaminated habitats and then act as reservoirs and potential spreaders of resistant elements through migration. However, the role of migratory wild birds as antimicrobial disseminators in the Arabian Peninsula desert, which represents a transit point for birds migrating all over Asia, Africa, and Europe not yet clear. Therefore, the present study objective was to determine antimicrobial-resistant bacteria in samples collected from migratory wild birds around Al-Asfar Lake, located in Al-Ahsa Oasis, Eastern Saudi Arabia, with a particular focus on Escherichia coli virulence and resistance genes. Cloacal swabs were collected from 210 migratory wild birds represent four species around Al-Asfar. E. coli, Staphylococcus, and Salmonella spp. have been recovered from 90 (42.9%), 37 (17.6%), and 5 (2.4%) birds, respectively. Out of them, 19 (14.4%) were a mixed infection. All samples were subjected to AMR phenotypic characterization, and results revealed (14–41%) and (16–54%) of E. coli and Staphylococcus spp. isolates were resistant to penicillins, sulfonamides, aminoglycoside, and tetracycline antibiotics. Multidrug-resistant (MDR) E. coli and Staphylococcus spp. were identified in 13 (14.4%) and 7 (18.9%) isolates, respectively. However, none of the Salmonella isolates were MDR. Of the 90 E. coli isolates, only 9 (10%) and 5 (5.6%) isolates showed the presence of eaeA and stx2 virulence-associated genes, respectively. However, both eaeA and stx2 genes were identified in four (4.4%) isolates. None of the E. coli isolates carried the hlyA and stx1 virulence-associated genes. The E. coli AMR associated genes blaCTX-M, blaTEM, blaSHV, aac(3)-IV, qnrA, and tet(A) were identified in 7 (7.8%), 5 (5.6%), 1 (1.1%), 8 (8.9%), 4 (4.4%), and 6 (6.7%) isolates, respectively. While the mecA gene was not detected in any of the Staphylococcus spp. isolates. Regarding migratory wild bird species, bacterial recovery, mixed infection, MDR, and AMR index were relatively higher in aquatic-associated species. Overall, the results showed that migratory wild birds around Al-Asfar Lake could act as a reservoir for AMR bacteria enabling them to have a potential role in maintaining, developing, and disseminating AMR bacteria. Furthermore, results highlight the importance of considering migratory wild birds when studying the ecology of AMR

Diversity and Risk Factors Associated with Multidrug and Methicillin-Resistant Staphylococci Isolated from Cats Admitted to a Veterinary Clinic in Eastern Province, Saudi Arabia

Understanding the distribution, antimicrobial resistance (AMR), and risk factors associated with multidrug-resistant (MDR) and methicillin-resistant staphylococci (MRS) isolated from cats admitted to veterinary clinics may decrease the risk of MDR and MRS transmission to humans and other cats. As such, the objectives of this study were to investigate the diversity in Staphylococcus spp. recovered from different anatomical locations in healthy and diseased cats and to determine the occurrence of MDR and MRS spp. as well as possible risk factors associated with colonization in these cats. Five swabs were collected from the anus, skin, ear canal, conjunctival sac, and nares of each cat (209 healthy and 191 diseased) admitted to a veterinary clinic in Eastern Province, Saudi Arabia, between January and December 2018. Prior to sample collection, cat owners completed a questionnaire collecting information on cat demographics, health status, management, and antimicrobial usage. In total, 179 Staphylococcus isolates were recovered from healthy (n = 71) and diseased (n = 108) cats, including 94 (52.5%) coagulase-positive staphylococci (CoPS), and 85 (47.5%) coagulase-negative staphylococci (CoNS). Five Staphylococcus spp. were identified, namely, Staphylococcus aureus, Staphylococcus pseudintermedius, Staphylococcus felis, Staphylococcus capitis, and Staphylococcus saprophyticus. Staphylococcus isolates were most commonly resistant to penicillin (56.4%) and ciprofloxacin (25.7%); however, no isolate was resistant to clindamycin. Thirty (16.8%) Staphylococcus spp. (24 S. aureus and 6 S. pseudintermedius) isolates were MDR, with resistance to up to six different antibiotic classes. Only 17 (9.5%) Staphylococcus spp. (15 methicillin-resistant S. aureus and 2 methicillin-resistant S. pseudintermedius) harbored the mecA gene. Risk factor analysis showed that cats with a history of antibiotic therapy, those raised mainly indoors with a child, and those who visit a veterinary clinic for treatment were at higher risk of MDR and MRS colonization. In conclusion, MDR and MRS were common in healthy and diseased cats in Saudi Arabia. Thus, an effective antimicrobial stewardship program and further studies using a One Health approach are required to investigate the role of cats as vectors for AMR transmission to humans

Lime and manure amendment improve soil fertility, productivity and nutrient uptake of rice-mustard cropping pattern in an acidic terrace soil

Acid soil is an obstacle to agricultural development and a concern regarding food and environmental security. Therefore, a study was carried out for two consecutive years to see how lime and organic manure (OM) amendments affect yield and nutrient absorption in the Transplanted (T.) Aman–Mustard–Boro cropping pattern in an acidic terrace soil. With nine treatments and three replications, the experiment was set in a randomized complete block design. The treatments were applied to the first crop, T. Aman, with different dosages of lime (dololime at the rate of 1 and 2 t ha−1), OM (cow dung at 5 t ha−1, poultry manure at 3 t ha−1) and lime–OM combination, and their residual effects were studied in the following mustard and boro rice crops. Results demonstrate that the effect of lime and manure was more pronounced in the case of the second and third crops in the first year and of all crops in the pattern in the second year. In the first year, grain and straw yield of T. Aman as well as the overall system productivity were not influenced significantly by the application of lime and manure, but significant increases were obtained in the second year. As an average of both years, the highest grain yield of 5.2 t ha−1 (12% over control) was recorded for T. Aman, 1.7 t ha−1 (41% over control) for mustard and 5.9 t ha−1 (47% over control, 3.9 t ha−1) for boro rice when dololime was applied in combination with poultry manure. In both years, N, P, K and S uptake were significantly increased compared to the control in all the crops due to the combined application of lime and cow dung or poultry manure. Combined application of lime and manure amendment significantly improved nutrient availability and soil quality. Therefore, applying lime in combination with manure can be practiced to uplift crop productivity in acidic terrace soils

EFFECTIVENESS OF ORAL ANALGESICS IN CONTROL OF DENTAL PAIN: A SYSTEMATIC REVIEW

Introduction: Trauma to either soft and hard tissues are usually associated with surgical dental extraction and deep cavity preparations, often accompanied with pain and swelling. The aim of this review was to review clinical trials investigating the effectiveness of oral analgesics in control of dental pain. Materials and methods: A web search was conducted in MEDLINE database and the resultant studies were screened for eligibility criteria including clinical trials conducted among human subjects in the last 5 year. The trials should aim to assess the effect of the analgesics in the control of postoperative dental pain. The full articles were retrieved for the eligible studies and the secondary screening was conducted to exclude the ineligible studies based on the full text reading. Results:Our search identified eligible 49 articles underwent full-text review and 8 met our inclusion criteria enrolling 2406 patients. Codeine 60mg added to a paracetamol 1000 mg/ibuprofen 400 mg regimen does not improve analgesia following third molar surgery. Tramadol/Acetaminophen decreased pain over time from time point 6 hours. Pain intensity was significantly lower over 24 hours with ER naproxen sodium vs. placebo. Etoricoxib was more effective than Paracetamol/ Acetaminophen and the placebo. Conclusion:Because of the absence of strong evidence, no clear evidence whether the foundational non-steroidal anti-inflammatory (NSAIDs) are more compelling than paracetamol at reducing pain related with dental treatment. Keywords: Analgesics, Dental, Surgery, Operative, Efficacy

Changes in dietary and lifestyle behaviors and mental stress among medical students upon Ramadan diurnal intermittent fasting: a prospective cohort study from Taif/Saudi Arabia

Abstract Background Intermittent fasting (IF) is a popular dietary plan for weight loss. In fact, fasting is a common practice in different religions such as Buddhism, Hinduism, Judaism, Christianity, and Islam. During the month of Ramadan, more than 1.5 billion Muslims worldwide fast from dawn to sunset. Ramadan diurnal intermittent fasting (RDIF) has health benefits, including a reduction in cardiovascular disease (CVD) risk and an improvement in mood. However, little is known about the effects of RDIF on lifestyle behaviors, such as regular exercise, consuming healthy diet, and avoiding harmful substances, as well as mental stress, and academic performance in high school and university students. Methods In this prospective cohort study, two self-reported questionnaires were sent one week before and during the last week of Ramadan (April 2022; Ramadan 1443 in Hijri Islamic Calendar) to assess changes in lifestyle, perceived stress, and academic achievement of medical students at Taif University in Taif city, Saudi Arabia. Healthy lifestyle components data were collected to calculate healthy lifestyle scores, including body mass index, physical activity, adherence to a Mediterranean diet, smoking status, and sleep duration. Results RDIF was associated with a healthier lifestyle in both female and male participants (pre-RDIF mean score: 2.42 vs post-RDIF mean score: 2.74; statistical power = 0.99; P-value < 0.05). They were more active and adherent to the Mediterranean diet during RDIF. Additionally, the post-RDIF smoking rate declined by 53.4%. Male participants showed higher perceived stress scores during RDIF (pre-RDIF mean score: 19.52 vs post-RDIF mean score: 22.05; P-value < 0.01). No changes in academic performance were observed upon RDIF. Conclusion Medical students show healthier dietary and lifestyle behaviors and their academic performance is not affected during RDIF. However, perceived stress is higher among male students

Adsorption of Methylene Blue by Biosorption on Alkali-Treated <i>Solanum incanum</i>: Isotherms, Equilibrium and Mechanism

In this study, a new bio-adsorbent (NASIF) was successfully prepared via chemical activation of Solanum incanum (SI) with hydrogen peroxide and sodium hydroxide reagents as an inexpensive and effective adsorbent for the removal of methylene blue (MB) from aqueous media. The morphology of the NASIF adsorbent surface and the nature of the potential MB interactions were examined by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) micrograph. FTIR results suggested that carboxyl, carbonyl, and hydroxyl groups were involved in MB adsorption on the NASIF surface. EDX analysis confirmed the successful increase of oxygen-containing functional groups during the chemical activation. The influence of important factors was studied using the batch method. The results revealed that the maximum removal efficiency was 98% at contact time: 120 min; pH: 6.5, adsorbent dose: 40 mg; and temperature-25 °C. Isothermal behavior was evaluated using three non-linear isotherm models, Langmuir, Freundlich, and D–R isotherm. MB adsorption onto NASIF adsorbent followed the Langmuir isotherm model with maximum monolayer capacity (mg/g) at 25 °C. Meanwhile, the PSO kinetics model was found to be better than PFO kinetic model for describing the adsorption process using kinetic models. Based on the D–R model, the free energy (E, kJ mol−1) values were in the range of 0.090–0.1812 kJ mol−1, which indicated that the MB adsorption onto NASIF may belong to physical adsorption. The adsorption mechanism of MB onto NASIF adsorbent mainly includes electrostatic attraction, π-π interaction, n-π interaction, and H-bonding. The thermodynamic parameters revealed that the adsorption process was a feasibility, spontaneous and exothermic process. Finally, the result of the present work could provide strong evidence of the potential of NASIF adsorbent for eliminating MB from aqueous media

Adsorption of Methylene Blue by Biosorption on Alkali-Treated Solanum incanum: Isotherms, Equilibrium and Mechanism

In this study, a new bio-adsorbent (NASIF) was successfully prepared via chemical activation of Solanum incanum (SI) with hydrogen peroxide and sodium hydroxide reagents as an inexpensive and effective adsorbent for the removal of methylene blue (MB) from aqueous media. The morphology of the NASIF adsorbent surface and the nature of the potential MB interactions were examined by Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM) micrograph. FTIR results suggested that carboxyl, carbonyl, and hydroxyl groups were involved in MB adsorption on the NASIF surface. EDX analysis confirmed the successful increase of oxygen-containing functional groups during the chemical activation. The influence of important factors was studied using the batch method. The results revealed that the maximum removal efficiency was 98% at contact time: 120 min; pH: 6.5, adsorbent dose: 40 mg; and temperature-25 &deg;C. Isothermal behavior was evaluated using three non-linear isotherm models, Langmuir, Freundlich, and D&ndash;R isotherm. MB adsorption onto NASIF adsorbent followed the Langmuir isotherm model with maximum monolayer capacity (mg/g) at 25 &deg;C. Meanwhile, the PSO kinetics model was found to be better than PFO kinetic model for describing the adsorption process using kinetic models. Based on the D&ndash;R model, the free energy (E, kJ mol&minus;1) values were in the range of 0.090&ndash;0.1812 kJ mol&minus;1, which indicated that the MB adsorption onto NASIF may belong to physical adsorption. The adsorption mechanism of MB onto NASIF adsorbent mainly includes electrostatic attraction, &pi;-&pi; interaction, n-&pi; interaction, and H-bonding. The thermodynamic parameters revealed that the adsorption process was a feasibility, spontaneous and exothermic process. Finally, the result of the present work could provide strong evidence of the potential of NASIF adsorbent for eliminating MB from aqueous media

Removal of Biomass and Nutrients by Weeds and Direct-Seeded Rice under Conservation Agriculture in Light-Textured Soils of North-Western India

The escalating scarcity of irrigation water, transplantation of rice on light-textured soils and labour cost acted as major drivers for the transition towards direct-seeded rice (DSR) cultivation from the conventionally flooded transplanting system. Despite these advantages, DSR is a challenge in light texture soil due to heavy weed infestation and a slight decline in crop yield. The weeds compete for nutrients and have an adverse effect on the growth and yield of crops. Hence, to assess the removal of macro and micronutrients by weeds and direct-seeded rice, a field experiment was carried out on sandy loam soil for two consecutive Kharif seasons (2018 and 2019). Three treatments from rice, namely: DSR under zero tillage (DSR-ZT), DSR under conventional tillage (DSR-CT) and DSR under reduced tillage (DSR-RT) were taken as main plots with three tillage treatments in wheat, namely: Conventional tillage without rice straw (CTW-R), Zero tillage without rice straw (ZTW-R) and Zero tillage with straw as mulch using Happy Seeder (ZTW+R) as subplots, replicated thrice. Among the rice establishment methods, DSR-RT showed an edge in terms of rice grain and straw yield (6.18 and 8.14 Mg ha−1, respectively) as well as macro- and micronutrient uptake by rice. Under management practices, ZTW+R proved as an efficient strategy in terms of yield and nutrient uptake by crops. The contribution of weeds towards biomass production was maximum under the ZTW-R (9.44%) treatment followed by DSR-ZT (7.72%). The nutrient budgeting showed that macro- and micronutrient removal by weeds was minimum under reduced tillage (24.51 and 50.35%, respectively), whereas it was 21.88 and 44.87% when wheat was grown under conventional tillage without rice straw. In overall, the research study concluded that weeds on an average remove 25.65 % macronutrients (N, P, K) and 51.47% of micronutrients (Zn, Cu, Fe and Mn) in DSR under rice-wheat cropping system