Decolorization of various dyes by microorganisms and green-synthesized nanoparticles: current and future perspective

Various types of colored pigments have been recovered naturally from biological sources including shells, flowers, insects, and so on in the past. At present, such natural colored substances (dyes) are replaced by manmade dyes. On the other hand, due to their continuous usage in various purpose, these artificial dyes or colored substances persist in the environmental surroundings. For example, industrial wastewater contains diverse pollutant substances including dyes. Several of these (artificial dyes) were found to be toxic to living organisms. In recent times, microbial-based removal of dye(s) has gained more attention. These methods were relatively inexpensive for eliminating such contaminants in the environmental system. Hence, various researchers were isolated microbes from environmental samples having the capability of decolorizing synthetic dyes from industrial wastewater. Furthermore, the microorganisms which are genetically engineered found higher degradative/decolorize capacity to target compounds in the natural environs. Very few reviews are available on specific dye treatment either by chemical treatments or by bacteria and/or fungal treatments. Here, we have enlightened literature reports on the removal of different dyes in microbes like bacteria (including anaerobic and aerobic), fungi, GEM, and microbial enzymes and also green-synthesized nanoparticles. This up-to-date literature survey will help environmental managements to co-up such contaminates in nature and will help in the decolorization of dyes.

Various strategies applied for the removal of emerging micropollutant sulfamethazine: a systematic review

Pharmaceutical active drug(s) especially sulfamethazine (SMZ) is considered as one of the major emerging microcontaminants due its long-term existence in the environmental system and that can influence on the developmental of antibacterial resistance genes. Because of this region it has a great concern in the aquatic system. Moreover, the vast utilization of SMZ, excretion of undigested portion by animals and also through dumping or mishandling, SMZ is frequently detected in various samples (including water) of different places and its surroundings. Additionally, reports shown it has toxic effect against microalgae and mice. Thus, that can lead to several investigators, focusing on removal of SMZ alone or in combination of other drugs in wastewater treatment plants (WWTPs) either by abiotic and/or biotic treatment methods. The present review provides an overview of the toxic effect of SMZ and SMZ degradation/removal in abiotic and biotic processes. Finally, reveals the need of further implication of integrated treatments (including engineered biological mediators) to understand ideal biological approaches for the mineralization of SMZ.

Retrospective Analysis on Antimicrobial Resistance Trends and Prevalence of β-lactamases in Escherichia coli and ESKAPE Pathogens Isolated from Arabian Patients during 2000-2020

The production of diverse and extended spectrum β-lactamases among Escherichia coli and ESKAPE pathogens is a growing threat to clinicians and public health. We aim to provide a comprehensive analysis of evolving trends of antimicrobial resistance and β-lactamases among E. coli and ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acine to bacter baumannii, Pseudomonas aeruginosa, and Enterobacter species) in the Arabian region. A systematic review was conducted in Medline PubMed on papers published between January 2000 and February 2020 on countries in the Arab region showing different antibiotic resistance among E. coli and ESKAPE pathogens. A total of n = 119,144 clinical isolates were evaluated for antimicrobial resistance in 19 Arab countries. Among these clinical isolates, 74,039 belonged to E. coli and ESKAPE pathogen. Distribution of antibiotic resistance among E. coli and ESKAPE pathogens indicated that E. coli (n = 32,038) was the predominant pathogen followed by K. pneumoniae (n = 17,128), P. aeruginosa (n = 11,074), methicillin-resistant S. aureus (MRSA, n = 4370), A. baumannii (n = 3485) and Enterobacter spp. (n = 1574). There were no reports demonstrating Enterococcus faecium producing β-lactamase. Analyses revealed 19 out of 22 countries reported occurrence of ESBL (Extended-Spectrum β-Lactamase) producing E. coli and ESKAPE pathogens. The present study showed significantly increased resistance rates to various antimicrobial agents over the last 20 years; for instance, cephalosporin resistance increased from 37 to 89.5%, fluoroquinolones from 46.8 to 70.3%, aminoglycosides from 40.2 to 64.4%, mono-bactams from 30.6 to 73.6% and carbapenems from 30.5 to 64.4%. An average of 36.9% of the total isolates were reported to have ESBL phenotype during 2000 to 2020. Molecular analyses showed that among ESBLs and Class A and Class D β-lactamases, bla_CTX-M and bla_OXA have higher prevalence rates of 57% and 52.7%, respectively. Among Class B β-lactamases, few incidences of bla_VIM 27.7% and bla_NDM 26.3% were encountered in the Arab region. Conclusion: This review highlights a significant increase in resistance to various classes of antibiotics, including cephalosporins, β-lactam and β-lactamase inhibitor combinations, carbapenems, aminoglycosides and quinolones among E. coli and ESKAPE pathogens in the Arab region.

Metabolism of drugs and carcinogens in man: antipyrine elimination as an indicator

The suitability of the most commonly used "prototype" drug, viz, antipyrine, in predicting drug and carcinogen metabolism was evaluated, by studying in vivo antipyrine elimination rate (Ke) and in vitro metabolism of drugs and carcinogens in liver preparations in the same individuals. Our subjects were 20 adult males undergoing abdominal surgery for gastrojejunostomy, although antipyrine Ke could be studied in only 16 subjects. Correlations of the various in vito--in vivo parameters were positive between the parameter pairs: in vivo antipyrine Ke--in vitro benzopyrene hydroxylase; benzopyrene hydroxylase--aniline hydroxylase; and benzopyrene hydroxylase--gamma-glutamyl transferase. Aminopyrine demethylase did not correlate with any of the parameters studied. The degree of correlation between antipyrine Ke and benzopyrene hydroxylase was statistically significant but was not satisfactory for predictive purposes. Our study indicates some of the problems and limitations of in vivo--in vitro comparisons and confirms earlier doubts on the usefulness of antipyrine as a "prototype" drug for predicting drug and carcinogen metabolism in man.