Performance, kinetic, and biodegradation pathway evaluation of anaerobic fixed film fixed bed reactor in removing phthalic acid esters from wastewater

Emerging and hazardous environmental pollutants like phthalic acid esters (PAEs) are one of the recent concerns worldwide. PAEs are considered to have diverse endocrine disrupting effects on human health. Industrial wastewater has been reported as an important environment with high concentrations of PAEs. In the present study, four short-chain PAEs including diallyl phthalate (DAP), diethyl phthalate (DEP), dimethyl phthalate (DMP), and phthalic acid (PA) were selected as a substrate for anaerobic fixed film fixed bed reactor (AnFFFBR). The process performances of AnFFFBR, and also its kinetic behavior, were evaluated to find the best eco-friendly phthalate from the biodegradability point of view. According to the results and kinetic coefficients, removing and mineralizing of DMP occurred at a higher rate than other phthalates. In optimum conditions 92.5, 84.41, and 80.39% of DMP, COD, and TOC were removed. DAP was found as the most bio-refractory phthalate. The second-order (Grau) model was selected as the best model for describing phthalates removal

Carbohydrate sources for macadamia shoot development

The effect of carbohydrate sources on vegetative growth in macadamia at two major flushing times (March and September in southern hemisphere) were studied indirectly by measuring the growth rate of individual flushes in response to girdling and defoliation treatments during the vegetative growth period. Internode length and girth of a single flush were affected significantly by girdling and defoliation treatments. Two sources of carbohydrate were hypothesised for vegetative growth of the single flush; reserved carbohydrate and current photosynthate. The contribution of these sources to vegetative growth were defined and calculated from the differences between the combinations of girdling and defoliation treatments over time. Based on the results for two major flushing times, reserved carbohydrate contributes more to vegetative growth of macadamia than current photosynthesis

Allometric relationships for vegetative growth flush in pruned stems of macadamia (Macadamia integrifolia): effects of carbohydrate source and season

Hedging is used to control tree size in macadamia orchards, but the effects on subsequent shoot growth and floral initiation may impair fruit production. Four-year-old grafted macadamia (Macadamia integrifolia Maiden & Betche) trees were subjected to pruning of the most recent seasonal shoot in autumn and spring. Factorial combinations of treatments included girdling or not girdling near the base of the previous season's (parent) shoot; removal of all except two, four or six leaves from the parent shoot; and defoliation or no defoliation of the shoot that appeared after pruning. Initial numbers and dimensions of flush-shoot internodes were similar for all branch treatments in autumn and for girdled branches in spring, and were smaller than half those for non-girdled stems in spring. Later flush-shoot growth depended on the number of leaves retained on the parent shoot, the presence or absence of a connection to the tree below the parent shoot, and on the season, declining with limiting growing degree-days in winter and accelerating with increasing growing degree-days in summer. In both seasons, reserves beyond the parent (previous season's) shoot contributed the major source of carbohydrate for continuing flush-shoot growth, and particularly the growth of leaves. The combinations of seasonal conditions, shoot parameters before the commencement of flush-shoot growth, and flush-shoot morphology permit the inference of allometric relationships that can be applied to the quantitative modelling of vegetative shoot morphology and growth in macadamia

Phage therapy as a renewed therapeutic approach to mycobacterial infections: a comprehensive review

Mycobacterial infections are considered to a serious challenge of medicine, and the emergence of MDR and XDR tuberculosis is a serious public health problem. Tuberculosis can cause high morbidity and mortality around the world, particularly in developing countries. The emergence of drug-resistant Mycobacterium infection following limited therapeutic technologies coupled with the serious worldwide tuberculosis epidemic has adversely affected control programs, thus necessitating the study of the role bacteriophages in the treatment of mycobacterial infection. Bacteriophages are viruses that are isolated from several ecological specimens and do not exert adverse effects on patients. Phage therapy can be considered as a significant alternative to antibiotics for treating MDR and XDR mycobacterial infections. The useful ability of bacteriophages to kill Mycobacterium spp has been explored by numerous research studies that have attempted to investigate the phage therapy as a novel therapeutic/diagnosis approach to mycobacterial infections. However, there are restricted data about phage therapy for treating mycobacterial infections. This review presents comprehensive data about phage therapy in the treatment of mycobacterial infection, specifically tuberculosis disease

Expression of type II toxin-antitoxin systems and ClpP protease of methicillin-resistant Staphylococcus aureus under thermal and oxidative stress conditions

Background and Objectives: Staphylococcus aureus is a main human pathogen that causes a variety of chronic to persistent infections. Across the diverse factors of pathogenesis in bacteria, Toxin-Antitoxin (TA) systems can be considered as an antibacterial target due to their involvement in cellular physiology counting stress responses. Here, the expression of TA system genes and ClpP protease was investigated under the thermal and oxidative conditions in S. aureus strains. Materials and Methods: The colony-forming unit (CFU) was used to determine the effects of thermal and oxidative stresses on bacterial survival. Moreover, the expressions of TA system genes in S. aureus strains were evaluated 30 min and 1 h after thermal and oxidative stresses, respectively, by quantitative reverse transcriptase real-time PCR (qRT-PCR). Results: The cell viability was constant across thermal stress while oxidative stress induction showed a significantly decrease in the growth of Methicillin-Resistant S. aureus (MRSA) strain. Based on the qRT-PCR results, the expression of mazF gene increased under both thermal and oxidative stresses in the MRSA strain. Conclusion: A putative TA system (namely immA/irrA) most likely has a role under the stress condition of S. aureus. The MRSA strain responds to stress by shifting the expression level of TA genes that has diverse effects on the survival of the pathogen due to the stress conditions. The TA systems may be introduced as potential targets for antibacterial treatment

Comprehensive analysis of Enterococcus strains isolated from human microbiome and evaluation of their benefits for digestive system

Background: Some studies have highlighted a mutualistic relationship between human and Enterococcus spp.; however, other surveys have showed only a commensal connection. This study aimed to clearly answer this question that whether or not Enterococci strains have a beneficial potential for the human GI tract? Methods: The fecal samples were collected from 1000 healthy volunteers. Inhibitory potency of these bacteria was evaluated on three intestinal pathogens using phenotypic agar spot assay and genotypic PCR method. After typing bacteria by PFGE, the probiotic supplemented tests were used for evaluating Enterococci beneficial potential. Results: Out of 1000 fecal isolated Enterococci strains, 91 isolates were identified as E. faecium; entA (88.6) and entB (26.8) were present almost in all of the isolates. Also, 100 of the E. faecium isolates were active against EAEC and Shigella dysenteriae (zone �10 mm); however, these E. faecium isolates weren't effective against EPEC. Moreover, it was found that 9 out of 91 E. faecium isolates had >50 viability in bile salts and acid stress assays, and only 4 of these 9 acid-bile resistant isolates were able to adhere to HT-29 cell line. Conclusions: To sum up, almost 4 of human isolated Enterococcus spp. were shown to have a mutualistic behavior with an impressive probiotic potential. It is believed that in the future, these mutualistic Enterococci could be replaced by commensal ones in all people by taking probiotic supplements containing Enterococci. © 202

Antimicrobial susceptibility pattern and serotype distribution of streptococcus pneumoniae in the middle east region: A systematic review and meta-analysis

This study aimed to explore the prevalence, antimicrobial resistance levels, and serotype distribution of S. pneumoniae in the Middle East region. We conducted a systematic literature review by searching several databases including PubMed, ISI Web of Science, Scopus, Google scholar through 2000 to 2017 by using the following keywords: �Streptococcus pneumoniae�, �pneumococcus�, �serotype�, �Antibiotic resistance,� and �Middle East �in combination with �OR� and �AND� Boolean Operators within Title/Abstract/Keywords fields. We used a random-effects model to calculate the pooled prevalence and 95 confidence intervals (CIs) for binomial variables. All statistical analyses were done using STATA 12.0 (STATA Corp, College Station, TX). We found 73 articles appropriate, on the word of inclusion and exclusion criteria, for inclusion in this systematic review and meta-analysis. The result revealed that the pooled prevalence of S. pneumoniae carriage was 35 (95 CI: 26-44). The most frequent pneumococcal serotypes were19, 19F, 6, 23 and 6A/B which were found in 19,12, 11, 10 and 10 of isolates respectively. Pneumococcal resistance reported for azithromycin, cefaclor, clarithromycin, chloramphenicol, erythromycin, and tetracycline were 24, 37, 23, 11, 26, and 29 respectively, while vancomycin resistance was not reported. The highest resistant prevalence was reported against co-trimoxazole (Trimethoprim/sulfamethoxazole). For this antibiotic, a pooled resistance prevalence of 43 was identified. The present review demonstrates that the prevalence of S. pneumoniae carriage was high in the Middle East region. Surveillance must be continued in this region to evaluate. The resistance pattern and serotype distribution. © 2021 Tehran University of Medical Sciences

Global prevalence of colistin resistance in clinical isolates of Acinetobacter baumannii: A systematic review and meta-analysis

Introduction: Acinetobacter baumannii antimicrobial resistance is a public health concern in developing and developed countries, especially in the hospital setting. Understanding the antibiotic resistance profile can help to provide better guidelines for the prescription of appropriate antibiotics, reduction of antibiotic resistance, and introducing new and effective treatment options. Method: Using the PRISMA guidelines, databases of PubMed, Embase, and Cochrane Library were searched systematically from January 1, 2000, to January 1, 2018. All statistical analyses were carried out via Comprehensive Meta-Analysis Software Version 2.0 (Biostat, Englewood, NJ). Depending on the heterogeneity test, either random or fix effect models were used for determining the pooled prevalence of drug resistance. Result: A total of 150 studies were included from 41 countries of six different WHO regional offices worldwide. The highest and the lowest rate of resistance were observed for cefotaxime (99, 95 CI: 95�99.9) in Africa and colistin (1.1, 95 CI: 0.3�4.5) in Western Pacific, respectively. Lebanon (17.5, 95 CI: 16�19) and China (12, 95 CI: 3.5�32.5) had the highest and Germany (0.2, 95 CI: 0�2.5) had the lowest rate of resistance for colistin. Conclusion: Our analysis showed that prevalence and rate of increased colistin resistance in South-East Asia and Eastern Mediterranean countries are higher than other regions of the world. Therefore, the establishment of appropriate antibiotic usage guidelines should be essential in these countries. © 201