Photodynamic inactivation of Klebsiella pneumoniae biofilms and planktonic cells by 5-aminolevulinic acid and 5-aminolevulinic acid methyl ester

The treatment of Klebsiella pneumoniae, particularly extended-spectrum β-lactamase (ESBL)-producing K. pneumoniae, is currently a great challenge. Photodynamic antimicrobial chemotherapy is a promising approach for killing antibiotic-resistant bacteria. The aim of this study was to evaluate the capacity of 5-aminolevulinic acid (5-ALA) and its derivative 5-ALA methyl ester (MAL) in the presence of white light to cause photodynamic inactivation (PDI) of K. pneumoniae planktonic and biofilm cells. In the presence of white light, 5-ALA and MAL inactivated planktonic cells in a concentration-dependent manner. Biofilms were also sensitive to 5-ALA and MAL-mediated PDI. The mechanisms by which 5-ALA and MAL caused PDI of ESBL-producing K. pneumonia were also investigated. Exposure of K. pneumonia to light in the presence of either 5-ALA or MAL induced cleavage of genomic DNA and the rapid release of intracellular biopolymers. Intensely denatured cytoplasmic contents and aggregated ribosomes were also detected by transmission electron microscopy. Scanning electron microscopy showed that PDI of biofilms caused aggregated bacteria to detach and that the bacterial cell envelope was damaged. This study provides insights into 5-ALA and MAL-mediated PDI of ESBL-producing K. pneumoniae

Developmental morphology of cover crop species exhibit contrasting behaviour to changes in soil bulk density, revealed by X-ray computed tomography

Plant roots growing through soil typically encounter considerable structural heterogeneity, and local variations in soil dry bulk density. The way the in situ architecture of root systems of different species respond to such heterogeneity is poorly understood due to challenges in visualising roots growing in soil. The objective of this study was to visualise and quantify the impact of abrupt changes in soil bulk density on the roots of three cover crop species with contrasting inherent root morphologies, viz. tillage radish (Raphanus sativus), vetch (Vicia sativa) and black oat (Avena strigosa). The species were grown in soil columns containing a two-layer compaction treatment featuring a 1.2 g cm-3 (uncompacted) zone overlaying a 1.4 g cm-3 (compacted) zone. Three-dimensional visualisations of the root architecture were generated via X-ray computed tomography, and an automated root-segmentation imaging algorithm. Three classes of behaviour were manifest as a result of roots encountering the compacted interface, directly related to the species. For radish, there was switch from a single tap-root to multiple perpendicular roots which penetrated the compacted zone, whilst for vetch primary roots were diverted more horizontally with limited lateral growth at less acute angles. Black oat roots penetrated the compacted zone with no apparent deviation. Smaller root volume, surface area and lateral growth were consistently observed in the compacted zone in comparison to the uncompacted zone across all species. The rapid transition in soil bulk density had a large effect on root morphology that differed greatly between species, with major implications for how these cover crops will modify and interact with soil structure

Prognostic model to predict postoperative acute kidney injury in patients undergoing major gastrointestinal surgery based on a national prospective observational cohort study.

Background: Acute illness, existing co-morbidities and surgical stress response can all contribute to postoperative acute kidney injury (AKI) in patients undergoing major gastrointestinal surgery. The aim of this study was prospectively to develop a pragmatic prognostic model to stratify patients according to risk of developing AKI after major gastrointestinal surgery. Methods: This prospective multicentre cohort study included consecutive adults undergoing elective or emergency gastrointestinal resection, liver resection or stoma reversal in 2-week blocks over a continuous 3-month period. The primary outcome was the rate of AKI within 7 days of surgery. Bootstrap stability was used to select clinically plausible risk factors into the model. Internal model validation was carried out by bootstrap validation. Results: A total of 4544 patients were included across 173 centres in the UK and Ireland. The overall rate of AKI was 14·2 per cent (646 of 4544) and the 30-day mortality rate was 1·8 per cent (84 of 4544). Stage 1 AKI was significantly associated with 30-day mortality (unadjusted odds ratio 7·61, 95 per cent c.i. 4·49 to 12·90; P < 0·001), with increasing odds of death with each AKI stage. Six variables were selected for inclusion in the prognostic model: age, sex, ASA grade, preoperative estimated glomerular filtration rate, planned open surgery and preoperative use of either an angiotensin-converting enzyme inhibitor or an angiotensin receptor blocker. Internal validation demonstrated good model discrimination (c-statistic 0·65). Discussion: Following major gastrointestinal surgery, AKI occurred in one in seven patients. This preoperative prognostic model identified patients at high risk of postoperative AKI. Validation in an independent data set is required to ensure generalizability

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Pengaruh tingkat pendidikan dan pengalaman kerja terhadap peningkatan kinerja guru padamadrasah tsanawiyah nehgeri ma'rang pangkep

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Higher Levels of Aflatoxin M1 Contamination and Poorer Composition of Milk Supplied by Informal Milk Marketing Chains in Pakistan

The present study was conducted to observe the seasonal variation in aflatoxin M1 and nutritional quality of milk along informal marketing chains. Milk samples (485) were collected from three different chains over a period of one year. The average concentrations of aflatoxin M1 during the autumn and monsoon seasons (2.60 and 2.59 ppb) were found to be significantly higher (standard error of the difference, SED = 0.21: p = 0.003) than in the summer (1.93 ppb). The percentage of added water in milk was significantly lower (SED = 1.54: p < 0.001) in summer (18.59%) than in the monsoon season (26.39%). There was a significantly different (SED = 2.38: p < 0.001) mean percentage of water added by farmers (6.23%), small collectors (14.97%), large collectors (27.96%) and retailers (34.52%). This was reflected in changes in milk quality along the marketing chain. There was no difference (p = 0.178) in concentration of aflatoxin M1 in milk collected from the farmers (2.12 ppb), small collectors (2.23 ppb), large collectors (2.36 ppb) and retailers (2.58 ppb). The high levels of contamination found in this study, which exceed the standards set by European Union (0.05 ppb) and USFDA (0.5 ppb), demand radical intervention by regulatory authorities and mass awareness of the consequences for consumer health and safety

The Biological and Regulatory Role of Type VI Secretion System of Klebsiella pneumoniae

Wenke Liu,1,&ast; Min Li,1,&ast; Shiwen Cao,1 Hafiz Muhammad Ishaq,2 Huajie Zhao,1 Fan Yang,1 Liang Liu1 1Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China; 2Faculty of Veterinary and Animal Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan&ast;These authors contributed equally to this workCorrespondence: Liang Liu, Email [email protected]: Bacteria communicate with their surroundings through diverse secretory systems, and the recently discovered Type VI Secretion System (T6SS) has gained significant attention. Klebsiella pneumoniae (K. pneumoniae), an opportunistic pathogen known for causing severe infections in both hospital and animal settings, possesses this intriguing T6SS. This system equips K. pneumoniae with a formidable armory of protein-based weaponry, enabling the delivery of toxins into neighboring cells, thus granting a substantial competitive advantage. Remarkably, the T6SS has also been associated with K. pneumoniae’s ability to form biofilms and acquire resistance against antibiotics. However, the precise effects of the T6SS on K. pneumoniae’s functions remain inadequately studied, despite research efforts to understand the intricacies of these mechanisms. This comprehensive review aims to provide an overview of the current knowledge regarding the biological functions and regulatory mechanisms of the T6SS in K. pneumoniae.Keywords: Klebsiella pneumoniae, T6SS, competition, drug resistance, virulenc

Molecular Characterization of Klebsiella pneumoniae Isolated from Sputum in a Tertiary Hospital in Xinxiang, China

Yuqi Hao,1 Yong’ang Jiang,1 Hafiz Muhammad Ishaq,2 Wenke Liu,1 Huajie Zhao,1 Mingyong Wang,3 Fan Yang1 1Xinxiang Key Laboratory of Pathogenic Biology, Department of Pathogenic Biology, School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang, People’s Republic of China; 2Faculty of Veterinary and Animal Sciences, Muhammad Nawaz Shareef University of Agriculture, Multan, Pakistan; 3Xinxiang Key Laboratory of Immunoregulation and Molecular Diagnostics, School of Laboratory Medicine, Xinxiang Medical University,, Xinxiang, People’s Republic of ChinaCorrespondence: Fan Yang; Mingyong Wang, Email [email protected]; [email protected]: In clinical practice, Klebsiella pneumoniae (K. pneumoniae) is a common opportunistic pathogen responsible for nosocomial infection. This study aimed to analyze the trend of antimicrobial susceptibility and virulent characteristics of K. pneumoniae isolated from sputum. In clinics, data of the current study will help in the clinical treatment of K. pneumoniae infection.Results: The current research showed the resistance rates of the 20 K. pneumoniae isolates against 13 antibiotics ranged from 15.0% to 80.0%. The detection rate of extended spectrum β-lactamases (ESBLs) was up to 55%, while blaSHV was the most prevalent ESBLs genes. Four strains (25.0%) of K. pneumoniae presented hypermucoviscous phenotype (HMV). Moreover, 18 strains (90.0%) showed the stronger biofilm-forming ability. wzi, wabG, fimH, mrkD were the most prevalent virulence genes in current research. Ten strains were found capsule typing and the higher genetic diversity of colonizing K. pneumoniae in this region. K19 exhibited a strong positive correlation with imipenem resistance, while K1 showed strong correlations with magA. Furthermore, HMV phenotype showed significantly negative correlations with multidrug-resistant.Conclusion: In the hospital, the antibiotic resistance of K. pneumoniae (isolated from sputum samples) has a serious concern. Additionally, strains of K. pneumoniae show the higher genetic diversity.Keywords: Klebsiella pneumoniae, antimicrobial resistance, resistant genes, virulent genes, biofilm-formin

Different Selection Strategies for the Improvement of the Growth Performance and Carcass Traits of Japanese Quails

ABSTRACT The present study evaluated different selection strategies to improve the growth performance and carcass traits of Japanese quails. To this end, 540 Japanese quails previously selected for high body weight at three ages (10, 12 and 14 weeks) from four close-bred flocks (Major, Kaleem, Saadat and Zahid) were subjected to three selection strategies: pedigree-based, mass selection or random-bred (controls). For pedigree-based selection, 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1 bird each) with full pedigree and selected for high body weight were used, whereas in mass selection 324 birds (4 close-bred flocks × 3 age groups × 9 replicates × 3 birds each) with high body weight were selected to be the parents of next generation. Random-bred controls included 108 birds (4 close-bred flocks × 3 age groups × 9 replicates × 1bird each) which were not previously submitted to selection. The effects of selection strategies of Japanese quail parents from four close-bred flocks (CBF) at three ages on the performance growth and carcass traits of their progenies were measured. The parent flocks were selected at three ages (10, 12 and 14 weeks) and reared for 20 weeks, and their progenies were reared for four weeks. The progeny of pedigree-based selected parents presented better feed intake (g), body weight gain (g), feed conversion ratio, live and carcass weights (g), and carcass yield. The progeny of 10- and 14-week-old parents showed better growth performance and carcass traits, respectively. Moreover, there was no influence of CBF on growth and carcass traits. It was concluded that pedigree-based selection had pronounced effect on the growth performance and carcass traits of the progeny compared with mass selection and random breeding. It is suggested that parental ages of 10 and 14 weeks of age promote better progeny growth performance and carcass traits