Analysis of chlorhexidine, antibiotics and bacterial community composition in water environments from Brazil, Cameroon and Madagascar during the COVID-19 pandemic.

The widespread of chlorhexidine and antibiotics in the water bodies, which grew during the global COVID-19 pandemic, can increase the dispersion of antibiotic resistance. We assessed the occurrence of these pharmaceutical compounds as well as SARS-CoV-2 and analysed the bacterial community structure of hospital and urban wastewaters from Brazil, Cameroon, and Madagascar. Water and wastewater samples (n = 59) were collected between January-June 2022. Chlorhexidine, azithromycin, levofloxacin, ceftriaxone, gentamicin and meropenem were screened by Ultra-High-Performance Liquid Chromatography coupled with mass spectrometer. SARS-CoV-2 was detected based on the nucleocapsid gene (in Cameroon and Madagascar), and envelope and spike protein-encoding genes (in Brazil). The total community-DNA was extracted and used for bacterial community analysis based on the 16S rRNA gene. To unravel likely interaction between pharmaceutical compounds and/or SARS-CoV-2 with the water bacterial community, multivariate statistics were performed. Chlorhexidine was found in hospital wastewater effluent from Brazil with a maximum concentration value of 89.28 µg/L. Additionally, antibiotic residues such as azithromycin and levofloxacin were also present at concentrations between 0.32-7.37 µg/L and 0.11-118.91 µg/L, respectively. In Cameroon, azithromycin was the most found antibiotic present at concentrations from 1.14 to 1.21 µg/L. In Madagascar instead, ceftriaxone (0.68-11.53 µg/L) and levofloxacin (0.15-0.30 µg/L) were commonly found. The bacterial phyla statistically significant different (P < 0,05) among participating countries were Proteobacteria, Patescibacteria and Dependentiae which were mainly abundant in waters sampled in Africa and, other phyla such as Firmicutes, Campylobacterota and Fusobacteriota were more abundant in Brazil. The phylum Caldisericota was only found in raw hospital wastewater samples from Madagascar. The canonical correspondence analysis results suggest significant correlation of azithromycin, meropenem and levofloxacin with bacteria families such as Enterococcaceae, Flavobacteriaceae, Deinococcaceae, Thermacetogeniaceae and Desulfomonilaceae, Spirochaetaceae, Methanosaetaceae, Synergistaceae, respectively. Water samples were also positive for SARS-CoV-2 with the lowest number of hospitalized COVID-19 patients in Madagascar (n = 7) and Brazil (n = 30). Our work provides new data about the bacterial community profile and the presence of pharmaceutical compounds in the hospital effluents from Brazil, Cameroon, and Madagascar, whose limited information is available. These compounds can exacerbate the spreading of antibiotic resistance and therefore pose a risk to public health.

Design of novel solar-light-induced KBi6O9I/Ag-AgVO3 nanophotocatalyst with Ag-bridged Z-scheme charge carriers separation and boosted photo-elimination of hospital effluents.

In this research, a novel solar-light-induced KBi6O9I/Ag-AgVO3 nanophotocatalyst with an Ag-bridged Z-scheme structure has been designed and synthesized through a sonochemical method to photo-degrade antibiotic hospital contaminants under simulated solar-light irradiation. Synthesized nanophotocatalysts with varying KBi6O9I to Ag-AgVO3 weight ratios underwent N2 Adsorption-Desorption, XRD, TEM, UV-Vis DRS, FESEM and PL analyses. The Ag-bridged Z-scheme-structured KBi6O9I/Ag-AgVO3 (1:1) nanophotocatalyst, demonstrated broad light absorption within the solar-light spectrum and showcased effective photocatalytic efficacy in degrading tetracycline antibiotic (88.3% and 83.5% removal for 25 and 50 mg/L, respectively, after 120 min). This performance outperformed other composited photocatalysts, as well as pure Ag-AgVO3 and KBi6O9I photocatalysts. The enhanced degradation efficiency of the KBi6O9I/Ag-AgVO3 (1:1) composite can be ascribed to the synergistic interaction of various elements. These include the surface plasmon resonance impact of silver nanoparticles, their pronounced sensitivity to solar irradiation, and the Z-scheme heterojunction configuration. Collectively, these factors work together to minimize the recombination rate of photoinduced electron-hole pairs, thereby amplifying the efficacy of photodegradation. Furthermore, the KBi6O9I/Ag-AgVO3 (1:1) composite photocatalyst displayed sustained pollutants elimination performance even after undergoing four consecutive cycles.

Draft genome sequencing data of Enterococcus faecium BT22, a vancomycin-resistant opportunistic pathogen isolated from hospital effluents.

A vancomycin-resistant Gram-positive bacterium of the genus Enterococcus, designated as BT22, was isolated from untreated hospital effluents at Chettia Chlef Hospital. The complete genome of strain BT22 was sequenced using the Illumina MiSeq platform, revealing a total length of 2,577,707 bp, with 2462 coding sequences (CDS) and an average G+C content of 38.00 mol%. Phylogenomic analyses confirmed that strain BT22 belongs to the same species as Enterococcus faecium AVS0243, with a similarity of 99.79 %. The study identified 12 antibiotic resistance genes and one virulence gene in strain BT22. These genes confer resistance to various classes of antibiotics, including aminoglycosides, macrolides, tetracyclines, and vancomycin. However, the virulence gene identified codes for adhesion. Furthermore, mobile genetic elements, such as IS elements carried by a conjugative plasmid, were detected. The genomic sequencing data of E. faecium BT22 will be of great value to the scientific community, enabling comparative genomic analyses and a better understanding of antibiotic resistance mechanisms, particularly towards vancomycin. The genomic information has been deposited in the DDBJ/EMBL/GenBank databases under accession number JASSVD010000000, providing an essential resource in the fight against antibiotic resistance and the spread of resistant bacterial strains.

Detection and Characterization of Carbapenemase-Producing Escherichia coli and Klebsiella pneumoniae from Hospital Effluents of Ouagadougou, Burkina Faso.

Hospital wastewater is a recognized reservoir for resistant Gram-negative bacteria. This study aimed to screen for carbapenemase-producing Escherichia coli and Klebsiella pneumoniae and their resistance determinants in two hospital effluents of Ouagadougou. Carbapenem-resistant E. coli and K. pneumoniae were selectively isolated from wastewater collected from two public hospitals in Ouagadougou, Burkina Faso. Bacterial species were identified via MALDI-TOF mass spectrometry. Carbapenemase production was studied phenotypically using antibiotic susceptibility testing via the disk diffusion method. The presence of carbapenemases was further characterized by PCR. A total of 14 E. coli (13.59%) and 19 K. pneumoniae (17.92%) carbapenemase-producing isolates were identified with different distributions. They were, respectively, blaNDM (71.43%), blaVIM (42.86%), blaIMP (28.57%), blaKPC (14.29%), blaOXA-48 (14.29%); and blaKPC (68.42%), blaNDM (68.42%), blaIMP (10.53%), blaVIM (10.53%), and blaOXA-48 (5.26%). In addition, eight (57.14%) E. coli and eleven (57.89%) K. pneumoniae isolates exhibited more than one carbapenemase, KPC and NDM being the most prevalent combination. Our results highlight the presence of clinically relevant carbapenemase-producing isolates in hospital effluents, suggesting their presence also in hospitals. Their spread into the environment via hospital effluents calls for intensive antimicrobial resistance (AMR) surveillance.

Experimental design by response surface methodology for efficient cefixime uptake from hospital effluents using anion exchange membrane.

The excessive use of antibiotics and their ultimate routes to the environment have prompted the drug resistance, which is becoming a major ecological issue. In this work, we have evaluated the performance of quaternary ammonium poly (2, 6-dimethyl-1,4-phenylene oxide) and polyvinyl alcohol (QPPO/PVA) based anion exchange membrane against cefixime (a third generation cephalosporin antibiotic) present in hospital effluents. The membrane's surface morphology was studied through scanning electron microscopy. The optimization of experimental parameters through Response Surface Methodology helped to evaluate the inter parameter dependence and predict maximum uptake capacity (qe). The speculated value of qe (6.72 mg g-1) obtained through central composite design was close to the experimental value of 7.01 mg g-1 with percent relative error of 4.31%. Further, the evaluation of experimental data using isotherms (Langmuir and Freundlich) and kinetic models (pseudo-first-order and second-order) proposed that the interactions between cefixime and the membrane were physisorptive in nature. The intra-day and inter-day assays exhibited lower %RSD values of 0.4% (n = 5) and 0.3% (n = 5). Furthermore, a percentage recovery of 98.2% (n = 9) and limit of detection 1 × 10-5 µg mL-1 was observed. The chromatogram of the treated water samples presented only negligible amount of cefixime indicating a great potential of QPPO/PVA membrane for the removal of cefixime from real water samples. The membrane could be regenerated for three consecutive cycles without any prominent loss in efficiency.

Occurrence and characterization of ß-lactamase-producing bacteria in biomedical wastewater and in silico enhancement of antibiotic efficacy.

Wastewater discharged from hospitals is a recognized contributor to the dissemination of antibiotic-resistant bacteria and their associated genetic traits into the environment. This study focused on the analysis of ß-lactamase-producing pathogenic bacteria within untreated biomedical wastewater originating from various hospitals in Dhaka City, Bangladesh, as well as in silico evaluation and structural activity relationship mentioned antibiotics were evaluated. In silico drug design techniques were applied to identify the relationship with how the functional group impacts the binding energy. Out of the 184 isolates obtained from well-established hospital sewage discharge points in Dhaka, 89 were identified as ß-lactamase positive. These bacteria were subjected to antimicrobial susceptibility testing using the VITEK-2 assay, and their profiles of extended-spectrum beta-lactamase (ESBL) production were determined through molecular methodologies. Among the ß-lactamase-positive isolates, considerable resistance was observed, particularly against ampicillin, Ceftriaxone, Cefuroxime, and Meropenem. The predominant resistant species included Escherichia coli, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter cloacae. The study identified the prevalence of ESBL-producing genes, with blaNDM-1 being the most prevalent, followed by blaOXA-1, blaSHV, blaCTX-M, and blaKPC. None of the isolates carried the blaTEM gene. In addition to characterizing these bacteria, the research explored ways to enhance the binding energy of four existing antibiotics as new inhibitors through computational studies. The findings revealed significant improvements in binding energy. Specifically, Meropenem initially exhibited a binding energy of -7.5 kcal/mol, notably increasing to -8.3 kcal/mol after modification. With an initial binding energy was only -7.9 kcal/mol, Ampicillin experienced an enhancement, reaching -8.0 kcal/mol post-modification. Similarly, Ceftriaxone, with an initial binding energy of -8.2 kcal/mol, increased to -8.5 kcal/mol following structural adjustments. Finally, Cefuroxime, initially registering a binding energy of -7.1 kcal/mol, substantially increased to -8.9 kcal/mol after modification. This finding establishes a foundation for future investigations in the development of modified antibiotics to address the issue of antibiotic resistance. It presents prospective remedies for the persistent problem of antibiotic-resistant bacteria in healthcare and the environment.

OCCURRENCE OF METFORMIN IN ENVIRONMENTAL WATER SAMPLES AND COMPARISON WITH CONSUMPTION DATA FROM A SURROUNDING HOSPITAL OVER 5 YEARS: A RETROSPECTIVE CASE STUDY.

Context: The environmental occurrence of metformin has been frequently world-widely reported. Despite the diabetes susceptibility in the Chinese population, the studies on occurrence of metformin as environment disruptor in China are insufficient. Objective: To determine the occurrence trends and possible environmental pollution sources of metformin as an emerging micropollutant. Methods: High-performance liquid chromatography-electrospray ionization-tandem mass spectrometry system was used to detect the metformin levels in water samples collected from the Xi'an city Moat, China once a year from 2017 to 2021. Correlations among the metformin levels in moat water, in surrounding hospital wastewater, and hospital metformin consumption data were assessed using Pearson, Spearman and Kendall's tau-b correlation coefficients. Results: Occurrence of metformin was found in Xi'an city Moat water with levels in the range of 304-793 ng/L. Significant correlations were found between the metformin levels in city moat water and the total (or outpatient) metformin utilization data of the hospital. Conclusion: Data suggested the potential environmental issues posed by metformin in Xi'an city in China. The metformin consumption volume in the surrounding hospitals, especially at the outpatient services, could be used to predict the metformin concentrations in the moat water.

Antibiotic and analgesic residues in the environment - Occurrence and ecological risk study from the Sunyani municipality, Ghana.

The presence of five antibiotics (metronidazole, ciprofloxacin, amoxicillin, doxycycline, and chloramphenicol) and four analgesics (diclofenac, ibuprofen, paracetamol, and caffeine) were investigated in water and soil samples from the Sunyani municipality, Ghana. Liquid samples were collected from hospital effluents, sachet drinking water, municipal waterworks, river Tano, and dumpsite leachates, while soil samples were collected from dumpsites and municipal waterworks. All samples were prepared using solid-phase extraction (SPE) and analyzed via an HPLC- PDA method. All antibiotics analyzed, apart from metronidazole, were detected either in soil or water samples. Doxycycline and ciprofloxacin were present in almost all liquid samples. The investigated hospital effluents had antibiotic concentrations of up to 2.93 mg/L for doxycycline and 4.74 mg/L for ciprofloxacin. The highest concentration of any antibiotic found was 8.76 mg/L of amoxicillin in hospital effluents. The maximum concentration of analgesics in liquid samples analyzed was 3.20 mg/L (paracetamol) and 3.00 mg/kg (caffeine) in soil samples. Ecological risk assessment indicated that the pharmaceuticals pose a possible risk to some aquatic organisms. The findings from this study showed the presence of these pharmaceuticals at concentrations that could impact the ecosystem. Consistent monitoring of environmental levels and pursuing the development and implementation of a suitable remediation program is needed.

Plasmid sequence dataset of multidrug-resistant Enterobacterales isolated from hospital effluents and wastewater treatment plant.

We present plasmid sequences of 21 multidrug resistant isolates of Enterobacterales belonging to Escherichia coli (n=10), Klebsiella pneumoniae (n=9), Klebsiella oxytoca (n=1), and Citrobacter freundii (n=1). The isolates originated from effluent collected from hospital sewer pipes and from a wastewater treatment plant (WWTP) in a southwestern Hungarian city. Isolation was carried out using eosin methylene blue agar supplemented with ceftriaxone and the isolates were identified with MALDI-TOF MS. Screening for multidrug resistance was conducted by determining susceptibility to four chemical classes namely, beta-lactams, aminoglycoside, fluoroquinolone, and sulfonamide. Plasmid DNA was isolated by alkaline lysis method using the Monarch plasmid DNA miniprep kit from freshly grown pure colonies. Molecular typing and Illumina sequencing of plasmid DNA of multiresistant strains were performed. After the assembly of contigs, genes localized on plasmid sequences were determined and functionally annotated. These reconstructed plasmid sequences supplemented with gene functional annotations were deposited in the Mendeley data. Using these datasets different plasmid incompatibility groups were identified. These conjugative plasmids appear to play a key role in the transmission of multiple resistance genes in enteric bacteria via wastewater. The presented data may provide useful insight on the correlations between environmental antibiotic contamination and the development of bacterial resistance, which poses a serious public health threat.

Microbial Resistance to Carbapenems in Effluents from Gynaecological, Paediatric and Surgical Hospital Units.

The aim of this work is to identify and count antimicrobial resistance (AMR) in hospital effluents (HEs) of 2 units of the University Hospital Mohamed VI the Mother and Child Hospital (MCH) and the Ar-razi Surgical Hospital (ArzH), and to compare the two hospital units in terms of ARMs and seasonal variation. Each HE was sampled during 2016 and 2017. After identification of the pathogenic strains and determination of AMR, the results were reported for 24 ABs, including 3 carbapenems (CBP), and their consumption rates. The Predicted environmental concentration (PEC) rate of carbapenems in the HE of the study sites is calculated. A comparative analysis of the AMR of the isolated bacterial species was performed and related to the evolution of PEC in HEs. In the ArzH effluents:15 strains isolated, 7 are carbanepenem-resistant Enterobacteria (CRE) and are resistant to at least one of the 3 carbapenems tested. ArzH and MCH effluents respectively show some similarities: 26.87% and 28.57% of isolated bacteria are resistant to ertapenem while 43.48% and 57.14% are resistant to meropenem. However, for imipenem, the MCH effluent has a higher percentage of bacterial antibiotic resistance than ArzH. In addition, the percentage of resistance in each hospital unit effluent is mainly in relation with the increasing antibiotic consumption and predicted environmental values PEC for very antibiotic in each unit in the same period.

Pharmaceutical pollution of hospital effluents and municipal wastewaters of Eastern Canada.

Quantification of drugs residues in wastewaters of different sources could help better understand contamination pathways, eventually leading to effluent regulation. However, limited data are available for hospital-derived wastewaters. Here, an analytical method based on automated on-line solid-phase extraction liquid chromatography tandem mass spectrometry (on-line SPE - UPLC-MS/MS) was developed for the quantification of multi-class pharmaceuticals in wastewaters. Filtrate phase and suspended solids (SPM) were both considered to evaluate the distribution of targeted analytes. Experimental design optimization involved testing different chromatographic columns, on-line SPE columns, and loading conditions for the filtrate phase, and different organic solvents and cleanup strategies for suspended solids. The selected methods were validated with suitable limits of detection, recovery, accuracy, and precision. A total of 30 hospital effluents and 6 wastewater treatment plants were sampled to evaluate concentrations in real field-collected samples. Certain pharmaceuticals were quantified at high levels such as caffeine at 670,000 ng/L in hospital wastewaters and hydroxyibuprofen at 49,000 ng/L in WWTP influents. SPM samples also had high contaminant concentrations such as ibuprofen at 31,000 ng/g in hospital effluents, fluoxetine at 529 ng/g in WWTP influents or clarithromycin at 295 ng/g in WWTP effluents. Distribution coefficients (Kd) and particle-associated fractions (Φ) indicate that pharmaceuticals tend to have better affinity to suspended solids in hospital wastewater than in municipal wastewaters. The results also bring arguments for at source treatment of these specific effluents before their introduction into urban wastewater systems.

Characterization of ß-Lactamases and Multidrug Resistance Mechanisms in Enterobacterales from Hospital Effluents and Wastewater Treatment Plant.

Antimicrobials in wastewater promote the emergence of antibiotic resistance, facilitated by selective pressure and transfer of resistant genes. Enteric bacteria belonging to Escherichia coli, Klebsiella pneumoniae, Klebsiella oxytoca, Enterobacter cloacae, and Citrobacter species (n = 126) from hospital effluents and proximate wastewater treatment plant were assayed for susceptibility to four antimicrobial classes. The ß-lactamase encoding genes harbored in plasmids were genotyped and the plasmids were sequenced. A multidrug resistance phenotype was found in 72% (n = 58) of E. coli isolates, 70% (n = 43) of Klebsiella species isolates, and 40% (n = 25) of Enterobacter and Citrobacter species. Moreover, 86% (n = 50) of E. coli, 77% (n = 33) of Klebsiella species, and 25% (n = 4) of Citrobacter species isolates phenotypically expressed extended spectrum ß-lactamase. Regarding ESBL genes, blaCTX-M-27 and blaTEM-1 were found in E. coli, while Klebsiella species harbored blaCTX-M-15, blaCTX-M-30, or blaSHV-12. Genes coding for aminoglycoside modifying enzymes, adenylyltransferases (aadA1, aadA5), phosphotransferases (aph(6)-1d, aph(3″)-Ib), acetyltransferases (aac(3)-IIa), (aac(6)-Ib), sulfonamide/trimethoprim resistant dihydropteroate synthase (sul), dihydrofolate reductase (dfrA), and quinolone resistance protein (qnrB1) were also identified. Monitoring wastewater from human sources for acquired resistance in clinically important bacteria may provide a cheaper alternative in regions facing challenges that limit clinical surveillance.

Plasmidome analysis of a hospital effluent biofilm: Status of antibiotic resistance.

Plasmids are widely involved in the dissemination of characteristics within bacterial communities. Their genomic content can be assessed by high-throughput sequencing of the whole plasmid fraction of an environment, the plasmidome. In this study, we analyzed the plasmidome of a biofilm formed in the effluents of the teaching hospital of Clermont-Ferrand (France). Our analysis discovered >350 new complete plasmids, with a length ranging from 1219 to 40,193 bp. Forty-two plasmid incompatibility (Inc) groups were found among all the plasmid contigs. Ten large plasmids, described here in detail, were reconstructed from plasmid contigs, seven of which carried antibiotic resistance genes. Four plasmids potentially confer resistance to numerous families of antibiotics, including carbapenems, aminoglycosides, colistin, and chloramphenicol. Most of these plasmids were affiliated to Proteobacteria, a phylum of Gram-negative bacteria. This study therefore illustrates the composition of an environmental mixed biofilm in terms of plasmids and antibiotic resistance genes.

Anionic surfactants monitoring in healthcare facilities - a case of Belo Horizonte City, Brazil.

Surfactants are substances that when in aquatic environments can cause negative impacts. Hospital effluents carry numerous chemicals daily, including surfactants, used in sanitization and disinfection procedures. These chemicals are found in the effluents and reach water bodies due to a lack of proper removal in the wastewater treatment plants. The present study investigated data about wastewater monitored from healthcare facilities located in the city of Belo Horizonte, Brazil, focusing on anionic surfactants. The results showed 72 establishments monitoring this parameter, resulting in a median concentration of 1 mg L-1 and 2.49 mg L-1 mean value of anionic surfactants, between 2007 and 2019. It is also observed in the correlation between surfactants and oils in all healthcare establishment sizes, except for the medium-sized. Although anionic surfactants are the most used in cleaning product formulations, cationic surfactants still do not have specific legislation in the studied country that dictates a limit for discharge into sewage; consequently, they are not routinely monitored in effluents. However, these compounds are used in the formulation of routine hospital products.

A multi-biomarker approach for the early assessment of the toxicity of hospital wastewater using the freshwater organism Daphnia magna.

Hospital wastewater (HWW) contains different hazardous substances resulting from a combination of medical and non-medical activities of hospitals, including pharmaceutical residues. These substances may represent a threat to the aquatic environment if they do not follow specific treatment processes. Therefore, we aimed to investigate the effects of the untreated effluent collected from a general hospital in Mahdia City (Tunisia) on neonatal stages of the freshwater crustacean Daphnia magna. Test organisms were exposed to three proportions (3.12%, 6.25%, and 12.5% v/v) of HWW. After 48 h of exposure, a battery of biomarkers was measured, including the quantification of antioxidant enzymes [catalase (CAT) and total and selenium-dependent glutathione peroxidase (total GPx; Se-GPx)], phase II biotransformation isoenzymes glutathione-S-transferases (GSTs), cyclooxygenases (COX) involved in the regulation of the inflammatory process, and total cholinesterases (ChEs) activities. Lipid peroxidation (LPO) was measured to estimate oxidative damage. The here-obtained results showed significant decreases of CAT and GSTs activities and also on LPO content in daphnids, whereas Se-GPx activity was significantly increased in a dose-dependent manner. Impairment of cholinesterasic and COX activities were also observed, with a significant decrease of ChEs and an increase of COX enzymatic activities. Considering these findings, HWW was capable of inducing an imbalance of the antioxidant defense system, but without resulting in oxidative damage in test organisms, suggesting that peroxidases and alternative detoxifying pathways were able to prevent the oxidant potential of several drugs, which were found in the tested effluents. In general, this study demonstrated the toxicity of hospital effluents, measured in terms of the potential impairment of key pathways, namely neurotransmission, antioxidant defense, and inflammatory homeostasis of crustaceans.

Qualitative and Quantitative Analysis of Certain Aspects of the Cytotoxic and Genotoxic Hazard of Hospital Wastewaters by Using a Range of In Vitro Assays.

Health care facilities and hospitals generate significant amounts of wastewater which are released into the sewage system, either after a preliminary treatment or without any further treatment. Hospital wastewater may contain large amounts of hazardous chemicals and pharmaceuticals, some of which cannot be eliminated entirely by wastewater treatment plants. Moreover, hospital effluents may be loaded with a plethora of pathogenic microorganisms or other microbiota and microbiome residues. The need to monitor hospital effluents for their genotoxic hazard is of high importance, as detailed information is scarce. DNA-based information can be acquired directly from samples through the application of various molecular methods, while cell-based biomonitoring assays can provide important information about impaired cellular pathways or mechanisms of toxicity without prior knowledge of the identity of each toxicant. In our study, we evaluated samples of chlorinated hospital wastewater discharged into the sewage system after this disinfection process. The assessment of cytotoxicity, genotoxicity and mutagenicity of the hospital effluents was performed in vitro by using a broad battery of biomonitoring assays that are relevant for human health effects. All the tested hospital wastewater samples could be classified as potentially genotoxic, and it is concluded that the microbiota present in hospital wastewater might contribute to this genotoxic potential.

Using basic parameters to evaluate adsorption potential of alternative materials: example of amoxicillin adsorption by activated carbon produced from termite bio-waste.

The minimum set of parameters that can be used to assess the adsorption capacity of activated carbon (AC) produced from termite bio-waste was determined. Three types of AC were prepared: AC600 at 600 °C, MAC600 at the same temperature and impregnated with FeCl3, and AC800 at 800 °C. The influence of the solution pH on the adsorption, adsorption kinetics, isotherms and thermodynamic parameters was considered to characterize the amoxicillin (AMX) adsorption process. The AC materials had surface areas (m2 g-1) of approximately 248.8 for AC600, 501.6 for AC800 and 269.5 for MAC600, with point of zero charge (pHPZC) values of 8.3, 7.5 and 1.7, respectively. A time period of 30 min was chosen for the adsorption kinetics, which was best represented by the pseudo-first-order model for AC600, the intraparticle diffusion model for AC800 and the pseudo-second-order model for MAC600. Regarding the isotherms, a maximum adsorption of 23.4 mg g-1 was found for AC800. In general, the thermodynamic parameters demonstrated a non-spontaneous process. It seems that the medium conditions, the adsorbate and adsorbent characteristics, and the Gibbs free energy are the most important parameters to be considered in a preliminary assessment of the adsorption efficiency of specific adsorbent/adsorbate pairs.

Investigating the impact of hospital antibiotic usage on aquatic environment and aquaculture systems: A molecular study of quinolone resistance in Escherichia coli.

Quinolones are one of the most important classes of antibacterials available for the treatment of infectious diseases in humans. However, there is a growing concern about bacterial resistance to antimicrobials including quinolones. The spread of antibiotic-resistant bacteria in the aquatic environment has been recognized as a growing threat to public health and hospitals appear to be a major contributor to this. The objective of this study was to investigate the prevalence of quinolone resistance in Escherichia coli from selected water bodies receiving direct hospital effluents in Kerala, India. Standard disc diffusion and E-test were used for antibiotic susceptibility testing. As antibiotic resistance can develop in bacterial isolates by different means, EtBr Agar Cartwheel method was used to detect the efflux pump activity and presence of resistant genes was detected by PCR. The mechanism of transfer of plasmid mediated resistance was confirmed by conjugation experiments. A total of 209 multidrug-resistant Escherichia coli were isolated from different hospital effluent discharge sites and aquaculture farms located in their vicinity. Among them, qnrB was found to be most prevalent followed by qnrS, OqxAB, qnrA and aac (6')-Ib-cr. The results suggested that the antibiotics present at sub-inhibitory concentrations in direct hospital effluents increases the selection pressure impacting the cell function of even normal microorganisms in the aquatic environment to change the genetic expression of virulence factors or acquire resistance genes by different transfer mechanisms, posing a serious threat to public health.

Hospital wastewaters: A reservoir and source of clinically relevant bacteria and antibiotic resistant genes dissemination in urban river under tropical conditions.

The occurrence and dissemination of antibiotic resistant genes (ARGs) that are associated with clinical pathogens and the evaluation of associated risks are still under-investigated in developing countries under tropical conditions. In this context, cultivable and molecular approaches were performed to assess the dissemination of bacteria and the antibiotic resistance genes in aquatic environment in Kinshasa, Democratic Republic of the Congo. Cultivable approach quantified ß-lactam, carbapenem resistant, and total Escherichia coli and Enterobacteriaceae in river sediments and surface waters that receive raw hospital effluents. The molecular approach utilized Quantitative Polymerase Chain Reaction (qPCR) to quantify the total bacteria and the richness of relevant bacteria (Escherichia coli, Enterococcus, and Pseudomonas), and antibiotic resistance genes (ARGs: blaOXA-48, blaCTX-M, blaIMP, blaTEM) in sediment samples. Statistical analysis were employed to highlight the significance of hospital contribution and seasonal variation of bacteria and ARGs into aquatic ecosystems in suburban municipalities of Kinshasa, Democratic Republic of the Congo. The contribution of hospitals to antibiotic resistance proliferation is higher in the dry season than during the wet season (p < 0.05). Hospital similarly contributed Escherichia coli, Enterococcus, and Pseudomonas and ARGs significantly to the sediments in both seasons (p < 0.05). The organic matter content correlated positively with E. coli (r = 0.50, p < 0.05). The total bacterial load correlated with Enterococcus, and Pseudomonas (0.49 < r < 0.69, p < 0.05). Each ARG correlated with the total bacterial load or at least one relevant bacteria (0.41 < r < 0.81, p < 0.05). Our findings confirm that hospital wastewaters contributed significantly to antibiotic resistance profile and the significance of this contribution increased in the dry season. Moreover, our analysis highlights this risk from untreated hospital wastewaters in developing countries, which presents a great threat to public health.

Improving the biodegradability of hospital urines polluted with chloramphenicol by the application of electrochemical oxidation.

This work focuses on improving the biodegradability of hospital urines polluted with antibiotics by electrochemical advanced oxidation processes (EAOPs). To do this, chloramphenicol (CAP) has been used as a model compound and the influence of anodic material (Boron Doped Diamond (BDD) and Mixed Metal Oxide (MMO)) and current density (1.25-5 mA cm-2) on the toxicity and the biodegradability was evaluated. Results show that a complete CAP removal was attained using BDD anodes, being the process more efficient at the lowest current density tested (1.25 mA cm-2). Conversely, after passing 4 Ah dm-3, only 35% of CAP removal is reached using MMO anodes, regardless of the current density applied. Furthermore, a kinetic study demonstrated that there is a clear competitive oxidation between the target antibiotic and the organic compounds naturally contained in urine, regardless the current density and the anode material used. During the first stages of the electrolysis, acute toxicity is around 1% EC50 but it increases once CAP and its organic intermediates have been degraded. The formation and accumulation of inorganic oxidants may justify the remaining acute toxicity. This also helps to explain the trend observed in the rapid biodegradability assays. Finally, a 60% of standard biodegradability (Zahn-Wellens test) was achieved which suggests that electrochemical oxidation with BDD anodes could be the most appropriate technology to reduce the hazard of hospital urines at the operating conditions tested.