High Levels Of Antibiotics Research Articles

Uptake, Translocation, and Stability of Oxytetracycline and Streptomycin in Citrus Plants.

Huanglongbing (HLB), or citrus greening, is the most destructive disease to the citrus industry. In Florida, it is caused by the bacterium, Candidatus Liberibacter asiaticus (CLas) and is transmitted by the Asian citrus psyllid, Diaphorina citri. Recent studies suggested that antibiotics could inhibit the growth of the CLas pathogen in planta. In the current study, we investigated the uptake and translocation of oxytetracycline and streptomycin in citrus seedlings. Oxytetracycline and streptomycin were delivered via root and stem and their level in various tissues was monitored using enzyme-linked immunosorbent assay (ELISA). Oxytetracycline and streptomycin were detected in the leaves, xylem, phloem, and root after root drench and stem delivery. High levels of antibiotics were detected in the roots after root drench, whereas high levels of antibiotics were detected in the canopy after stem delivery. The level of oxytetracycline detected in the phloem, xylem, and leaves after root drench was higher than that of streptomycin. Whereas the level of streptomycin in root was higher than that of oxytetracycline, indicating that streptomycin was bound to the xylem tissues. Oxytetracycline and streptomycin were detected in the phloem, xylem, leaves, and root tissues thirty-five days after the root incubation in 200 µg·mL−1 solution. These results demonstrated that oxytetracycline and streptomycin were relatively stable and could inhibit CLas growth for a couple of months in citrus trees. Observations reported in this study regarding the distribution and stability of oxytetracycline and streptomycin in citrus plants could be useful for designing an effective program for the control of HLB disease using antibiotics.

Occurrence and distribution of clinical and veterinary antibiotics in the faeces of a Chinese population

Antibiotics ingested in the human gut may create selective pressure to change the composition of the gut microbiota, which could adversely effect the immune system of the host. However, the occurrence and distribution of antibiotics in the human gut remains unclear. A total population of 180 individuals, across three Chinses regions with different economic development levels, including children, adults, and elders, were sampled in 2017. A total of 19 representative antibiotics, including both clinical and veterinary antibiotics, were investigated in human faeces. While clinical use and prescriptions were the main exposure pathways for children, environmental media were the exposure pathway to adults. In addition, significant differences (P < 0.05) in antibiotic residues in human faeces were observed amongst various economic development levels, where human faeces from underdeveloped areas were mostly associated with higher levels of antibiotics. This study first to investigate the occurrence and distribution of typical antibiotics in the faeces of a Chinese population and thereby provide a reference for the intensive study of the effects and mechanisms of antibiotics on human gut microbiota.

Pretreatment of swine manure containing β-lactam antibiotics with whole-cell biocatalyst to improve biogas production

Abstract Biogas is one of the most popular renewable alternatives. Large quantities of antibiotics are used for rearing livestock resulting in the presence of high levels of antibiotics in manure, inhibiting biogas production during anaerobic digestion. In this study, a novel whole-cell biocatalyst that can accelerate degradation of antibiotics was developed by displaying β-lactamase on the cell surface of Escherichia coli. This biocatalyst showed high enzyme activity (4.93 ± 0.77 U/g dry weight of cells) in degrading β-lactam antibiotics and higher stability at room temperature than free β-lactamase. Penicillin, cefamezin, and amoxicillin were completely degraded in solution by the biocatalyst within 1 h. Pretreatment of swine manure containing 50 mg/kg and 100 mg/kg of penicillin, cefamezin, and amoxicillin with the new biocatalyst enhanced methane production by 37.1% and 93.2%, respectively during anaerobic digestion. The engineered biocatalyst protected the microbial community from antibiotic inhibition and hence is conducive for the growth of methanogens. This new strategy eliminates the inhibiting effects of antibiotics on manure, increasing the methane production and therefore achieving maximum utilization of renewable energy during anaerobic digestion. This pretreatment technology provides a new idea to treat manure containing antibiotics and improve energy efficiency.

Occurrence of Antibiotics and Antibiotic-Resistant Bacteria in Landfill Sites in Kumasi, Ghana

The incidence of antimicrobial resistance among microbial communities is a major threat to global health care and security. Landfills, which are reservoirs for many pharmaceuticals, provide a conducive habitat for antimicrobial-resistant microbes and resistant gene transfer and are therefore a major contributor to the phenomenon of antimicrobial resistance. Hence, this study determined the levels of three widely used antibiotics, metronidazole, penicillin, and amoxicillin, and the occurrence of antimicrobial resistance amongst microbes in soil and leachate samples from active and abandoned landfill sites in Kumasi, Ghana. Soil samples were collected from one active and four abandoned landfills, while leachate specimen was collected only from the active landfill. Sonication and solid-phase extraction (SPE) were used for sample preparation, followed by analysis via an HPLC-PDA method. Isolation and characterization of bacteria were done using standard bacteriological techniques. Antibiotic susceptibility testing was determined following the European Committee on Antimicrobial Susceptibility Testing (EUCAST) guidelines. Antibiotics were detected at very high concentrations in the specimen collected from both active and abandoned landfill sites. For leachate samples obtained from Dompoase, penicillin was present at the highest concentration (67.42 ± 5.35 μg/mL, p&lt;0.05) followed by metronidazole (18.25 ± 7.92 μg/mL) and amoxicillin (10.96 ± 6.93 μg/mL). In general, the levels of antibiotics in soil samples were similar at both active and abandoned landfill sites. Nonetheless, as with leachates, penicillin levels were much higher (p&lt;0.05) than levels of amoxicillin and metronidazole within any particular site. When screened against some antibiotics, Enterobacteriaceae and some Bacillus and Listeria species isolated from the soil and leachate samples proved to be resistant. The high levels of antibiotics coupled with the presence of resistant microbes at these landfills sites call for immediate measures to halt the disposal of pharmaceuticals in the environment so as to avert any possible public health setback.

Tolerance and Resistance of Pseudomonas aeruginosa Biofilms to Antimicrobial Agents-How P. aeruginosa Can Escape Antibiotics.

Pseudomonas aeruginosa is one of the six bacterial pathogens, Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter spp., which are commonly associated with antimicrobial resistance, and denoted by their acronym ESKAPE. P. aeruginosa is also recognized as an important cause of chronic infections due to its ability to form biofilms, where the bacteria are present in aggregates encased in a self-produced extracellular matrix and are difficult or impossible to eradicate with antibiotic treatment. P. aeruginosa causes chronic infections in the lungs of patients with cystic fibrosis and chronic obstructive lung disease, as well as chronic urinary tract infections in patients with permanent bladder catheter, and ventilator-associated pneumonia in intubated patients, and is also an important pathogen in chronic wounds. Antibiotic treatment cannot eradicate these biofilm infections due to their intrinsic antibiotic tolerance and the development of mutational antibiotic resistance. The tolerance of biofilms to antibiotics is multifactorial involving physical, physiological, and genetic determinants, whereas the antibiotic resistance of bacteria in biofilms is caused by mutations and driven by the repeated exposure of the bacteria to high levels of antibiotics. In this review, both the antimicrobial tolerance and the development of resistance to antibiotics in P. aeruginosa biofilms are discussed. Possible therapeutic approaches based on the understanding of the mechanisms involved in the tolerance and resistances of biofilms to antibiotics are also addressed.

Pharmaceuticals, herbicides, and disinfectants in agricultural water sources

Agricultural water withdrawals account for the largest proportion of global freshwater use. Increasing municipal water demands and droughts are straining agricultural water supplies. Therefore, alternative solutions to agricultural water crises are urgently needed, including the use of nontraditional water sources such as advanced treated wastewater or reclaimed water, brackish water, return flows, and effluent from produce processing facilities. However, it is critical to ensure that such usage does not compromise soil, crop, and public health. Here, we characterized five different nontraditional water types (n = 357 samples) for the presence of pharmaceuticals, herbicides, and disinfectants using ultra-high-pressure liquid chromatography tandem mass spectrometry based method (UPLC-MS/MS). We then evaluated whether the levels of these contaminants were influenced by season. The highest level of herbicides (atrazine) was detected in untreated pond water (median concentration 135.9 ng/L). Reclaimed water had the highest levels of antibiotics and stimulants including azithromycin (215 ng/L), sulfamethoxazole (232.1 ng/L), and caffeine (89.4 ng/L). Produce processing plant water also tended to have high levels of atrazine (102.7 ng/L) and ciprofloxacin (80.1 ng/L). In addition, we observed seasonal variability across water types, with the highest atrazine concentrations observed during summer months, while the highest median azithromycin concentrations were observed in reclaimed water during the winter season. Further studies are needed to evaluate if economically feasible on-farm water treatment technologies can effectively remove such contaminants from nontraditional irrigation water sources.

Enhanced antibiotic resistance development from fluoroquinolone persisters after a single exposure to antibiotic

Bacterial persisters are able to tolerate high levels of antibiotics and give rise to new populations. Persister tolerance is generally attributed to minimally active cellular processes that prevent antibiotic-induced damage, which has led to the supposition that persister offspring give rise to antibiotic-resistant mutants at comparable rates to normal cells. Using time-lapse microscopy to monitor Escherichia coli populations following ofloxacin treatment, we find that persisters filament extensively and induce impressive SOS responses before returning to a normal appearance. Further, populations derived from fluoroquinolone persisters contain significantly greater quantities of antibiotic-resistant mutants than those from untreated controls. We confirm that resistance is heritable and that the enhancement requires RecA, SOS induction, an opportunity to recover from treatment, and the involvement of error-prone DNA polymerase V (UmuDC). These findings show that fluoroquinolones damage DNA in persisters and that the ensuing SOS response accelerates the development of antibiotic resistance from these survivors.

Ultrasound-triggered antibiotic release from PEEK clips to prevent spinal fusion infection: Initial evaluations

Despite aggressive peri-operative antibiotic treatments, up to 10% of patients undergoing instrumented spinal surgery develop an infection. Like most implant-associated infections, spinal infections persist through colonization and biofilm formation on spinal instrumentation, which can include metal screws and rods for fixation and an intervertebral cage commonly comprised of polyether ether ketone (PEEK). We have designed a PEEK antibiotic reservoir that would clip to the metal fixation rod and that would achieve slow antibiotic release over several days, followed by a bolus release of antibiotics triggered by ultrasound (US) rupture of a reservoir membrane. We have found using human physiological fluid (synovial fluid), that higher levels (100–500 μg) of vancomycin are required to achieve a marked reduction in adherent bacteria vs. that seen in the common bacterial medium, trypticase soy broth. To achieve these levels of release, we applied a polylactic acid coating to a porous PEEK puck, which exhibited both slow and US-triggered release. This design was further refined to a one-hole or two-hole cylindrical PEEK reservoir that can clip onto a spinal rod for clinical use. Short-term release of high levels of antibiotic (340 ± 168 μg), followed by US-triggered release was measured (7420 ± 2992 μg at 48 h). These levels are sufficient to prevent adhesion of Staphylococcus aureus to implant materials. This study demonstrates the feasibility of an US-mediated antibiotic delivery device, which could be a potent weapon against spinal surgical site infection. Statement of SignificanceSpinal surgical sites are prone to bacterial colonization, due to presence of instrumentation, long surgical times, and the surgical creation of a dead space (≥5 cm3) that is filled with wound exudate. Accordingly, it is critical that new approaches are developed to prevent bacterial colonization of spinal implants, especially as neither bulk release systems nor controlled release systems are available for the spine. This new device uses non-invasive ultrasound (US) to trigger bulk release of supra-therapeutic doses of antibiotics from materials commonly used in existing surgical implants. Thus, our new delivery system satisfies this critical need to eradicate surviving bacteria, prevent resistance, and markedly lower spinal infection rates.

Occurrence and removal of antibiotics and antibiotic resistance genes in natural and constructed riverine wetlands in Beijing, China

Simultaneous elimination of antibiotics and antibiotic resistance genes (ARGs) is rarely investigated in full-scale riverine wetlands. Here, we compared the occurrence, abundance, and removal of 60 antibiotics and 27 ARGs in natural (Yeya Lake (YL)) and constructed (Bai River (BR)) riverine wetlands in Beijing, China. The concentrations of antibiotics in YL wetland were ND–51.9 ng/L in water and ND–37.9 ng/g in sediments. Significantly higher concentrations were found in BR wetland (ND–546 ng/L in water and ND–118 ng/g in sediments), which locates at the downstream of a reclaimed water treatment plant. The abundances of ARGs in YL and BR wetlands were up to 5.33 × 105 and 8.41 × 105 copies/mL in water, and 1.60 × 107 and 4.67 × 108 copies/g in sediments, respectively. These results suggest that wastewater greatly contributes to the elevated abundance of antibiotics and ARGs in both water and sediments. Compared to summer, higher levels of antibiotics in water were found in winter due to the higher usage, slower attenuation and the limited dilution. But higher abundances of ARGs were found in summer than in winter, in accordance with the favored microbial growth at higher temperature as denoted by copies of 16S rRNA. Compared to BR wetland, YL wetland achieved better removal of antibiotics and ΣARGs, with average removal efficiencies of 70.0% and 87.5%. Antibiotics, ARGs and environmental factors showed strong correlations in water samples from YL wetland. However, in BR wetland that receives urban wastewater effluents, no correlation between antibiotics and ARGs was found although the distribution of antibiotics was affected by aquatic environmental factors. These results indicate that subinhibitory concentrations of antibiotics may stimulate the prevalence of ARGs in natural wetlands.

Fecal pollution can explain antibiotic resistance gene abundances in anthropogenically impacted environments

Discharge of treated sewage leads to release of antibiotic resistant bacteria, resistance genes and antibiotic residues to the environment. However, it is unclear whether increased abundance of antibiotic resistance genes in sewage and sewage-impacted environments is due to on-site selection pressure by residual antibiotics, or is simply a result of fecal contamination with resistant bacteria. Here we analyze relative resistance gene abundance and accompanying extent of fecal pollution in publicly available metagenomic data, using crAssphage sequences as a marker of human fecal contamination (crAssphage is a bacteriophage that is exceptionally abundant in, and specific to, human feces). We find that the presence of resistance genes can largely be explained by fecal pollution, with no clear signs of selection in the environment, with the exception of environments polluted by very high levels of antibiotics from manufacturing, where selection is evident. Our results demonstrate the necessity to take into account fecal pollution levels to avoid making erroneous assumptions regarding environmental selection of antibiotic resistance.

Antibiotics in water and sediments of Danjiangkou Reservoir, China: Spatiotemporal distribution and indicator screening

Danjiangkou Reservoir is the largest artificial freshwater lake in China. The occurrence and spatiotemporal distribution of 77 antibiotics in water and sediment samples from Danjiangkou Reservoir were investigated. Approximately 90% of the detectable concentrations of the 61 and 54 antibiotics found in water and sediment samples were lower than 5.0 ng/L and 1.0 ng/g, respectively. Sulfamethoxazole was the most abundant antibiotic found in water (1.65–149 ng/L, median 6.25 ng/L). In sediment samples, macrolides were frequently detected (42.7–54.5%) at concentrations of ND–4.34 ng/g. Greater diversity and higher levels of antibiotics were generally found in both water and sediment samples in spring than in the other seasons. Composition profiles of antibiotics differed between the two tributary river basins of Danjiangkou Reservoir, indicating different sources of contamination and the influence of water and sediment properties. Four criteria, namely widespread occurrence, correlation with the total antibiotic concentration, and risk to aquatic organisms or to human health, were suggested to select specific indicators for monitoring and pollution control of antibiotics. Five antibiotics were selected as appropriate indicators for Danjiangkou Reservoir, namely sulfamethoxazole, trimethoprim, clarithromycin, roxithromycin, and anhydrochlortetracycline. This study adds to the understanding of the occurrence of antibiotics in water reservoirs and can assist authorities in regulating antibiotic contamination and designing effective strategies for risk minimization.

Synthesis and evaluation of cadiolide analogues as inhibitors of bacterial biofilm formation

Bacterial biofilm infections pose a major clinical challenge due to the ability of biofilms to resist high levels of conventional antibiotics. In the present study, we describe the synthesis and biofilm inhibiting properties of nine new butenolides related to the cadiolide family of marine antibiotics. Eight new cadiolide analogues were synthesized using oxazole−ynone Diels−Alder cycloaddition/cycloreversion as the key step. Their effects on bacterial growth and biofilm formation were investigated against a range of Gram-positive and Gram-negative bacteria, namely Staphylococcus aureus, Enterococcus faecalis, Acinetobacter baumannii, Escherichia coli, Klebsiella pneumoniae and Pseudomonas aeruginosa. The cadiolide analogues strongly inhibited biofilm formation of the two Gram-positive bacteria (S. aureus and E. faecalis) at concentrations as low as 0.3 μg mL−1 and 0.5 μg mL−1, respectively. The identification of synthetic cadiolides with potent biofilm-inhibiting capabilities opens a new avenue for therapeutic interventions and highlights the potential of this class of compounds for antimicrobial drug development.

Antibiotic distribution, risk assessment, and microbial diversity in river water and sediment in Hong Kong.

For the past fewer years, environment antibiotic residues have got more and more attention. The occurrence and distribution of eight common antibiotics, belonging to five classes, were determined in both water and sediment of eleven rivers of Hong Kong. The target antibiotics were found to be widely distributed. Sulfamethoxazole (n.d.-79.9ng/L), sulfadimidine (n.d.-29.9ng/L), and ofloxacin (n.d.-75.5ng/L) were the dominant antibiotics in river water, with detection rates of 84.6, 76.9, and 69.2%, respectively. Tetracycline (n.d.-9.8ng/g) was the dominant antibiotic in sediment, with a detection rate of 60%. The concentrations of all antibiotics in river water of Hong Kongwere lower than which in various rivers of Europe, North America and Australia, as well as the Pearl River Basin of China. All sediment sites exhibited significant bacterial diversity. Gammaproteobacteria (0.08-12.7%) and Flavobacteria (0.14-14.1%) were the dominant bacterial classes in all sediments. The bacterial compositions varied between sites; areas polluted with high levels of antibiotics had rich and highly diverse bacterial communities. The environmental risk assessment determined that the antibiotics in 73.1% of the samples posed ecological risks to algae, and two samples posed low risks to invertebrates. Ofloxacin was the main contributor of risk to aquatic organisms, while the antibiotics in 11.5% of the samples posed resistance selection risks. The occurrence and distribution of eight common antibiotics, belonging to five classes, were widely distributed in Hong Kong. Sulfamethoxazole, sulfadimidine, and ofloxacin were the dominant antibiotics in river waters, Tetracycline was the dominant antibiotic in sediment. Areas polluted with high levels of antibiotics had rich and highly diverse bacterial communities. Antibiotics in 73.1% of the samples posed ecological risks, while the antibiotics in 11.5% of the samples posed resistance selection risks.

Antibiotic susceptibility profile of Staphylococcus aureus from door handles in Nasarawa State University, Keffi, Nigeria

This study was carried out in order to determine the prevalence of Staphylococcus aureus on door handles and the antibiotic susceptibility of the organism to some commonly used antibiotics in Nasarawa State University, Keffi, Nigeria. A total of 100 door samples were obtained, 20 each from the five faculties within the university’s main campus. These were cultured and identified using appropriate protocols. A total of 26(26.0%) isolates were identified as Staphylococcus aureus. Faculties of Administration and Arts jointly accounted for the highest prevalence with 40%. The antibiotics susceptibility test revealed that Gentamicin was the most effective of all the test antibiotics against the Staphylococcus aureus isolated. The multidrug resistant S. aureus isolates 12(46.2%) were observed to have produced beta lactamase enzymes implicated in beta lactam antibiotics resistance. Observation from this study showed that there is a high level of antibiotics abuse or misuse with resultant multidrug-resistant S. aureus isolates in the study area.

Validation of the Declared Withdrawal Periods of Antibiotics

Drug residues in poultry and poultry products are becoming an alarming or burning concern for public health because of improper use of drugs/feed additive, or failure to observe drug withdrawal period, non-existence of restrictive legislation and lack of consumer awareness in the poultry industry. The declared withdrawal periods and safe level/tolerance level of any antibiotics will be stay in same points. The aim of the study was to validate the declared withdrawal periods and to see whether there is any alteration of these declared withdrawal periods that farmers are practicing in in-situ and ex- situ condition in Bangladesh context. For this, a total of 2100 broilers and 2100 eggs were collected from different markets of poultry rich area in seven divisions of Bangladesh. Seven different drugs such as Enrofloxacin, Oxytetracycline, Ciprofloxacin, Sulfonamide, Chloramphenicol, Gentamycin, Furazolidone were used as Maximum Residue Limit (MRL). In case of Enrofloxacin, Ciprofloxacin and Sulfonamides residues persist in broiler meat after the declared withdrawal periods, on the other hand Oxytetracycline, Cloramphenical and Gentamycin maintains the withdrawal period as per stated but the Furazolidone disappears for broiler meat before the declared withdrawal periods. It was found that 55% poultry samples remain above MRL during 1-3 interval period's in the validation of withdrawal period indicates not safe for human health. It can be concluded that lack of observation of withdrawal period might be a common practice given the high level of antibiotics in the poultry farm of Bangladesh.

Biofilms as a sink for antibiotic resistance genes (ARGs) in the Yangtze Estuary

Biofilms are ubiquitous throughout aquatic environments and they are thought to promote the acquisition and dissemination of antibiotic resistant genes (ARGs). This study focused on the occurrence and distribution of five types of ARG in naturally-occurring biofilms, in comparison to associated sediment and water samples, from the Yangtze Estuary, which borders the meta-city of Shanghai, China. The detection frequency and abundances of most ARGs showed the following order: biofilm > sediment > water, which can be attributed to a high level of antibiotics and metals that can accelerate the generation and propagation of ARGs in biofilms. Most of ARG abundances were contributed by extracellular DNA (eDNA) in biofilm and sediment samples. ARGs (sul1, sul2, tetA and tetW) in eDNA were significantly correlated with TOC in both biofilm and sediment samples. Furthermore, both intracellular DNA-associated ARGs per gram of microbial biomass carbon (MBC) and eDNA-associated ARGs per gram of non-MBC and were higher in biofilms than sediments, and the partitioning coefficients of ARGs in eDNA between biofilm and water were higher than those between sediment and water. Our results provide new insight for evaluating the occurrence and abundance of ARGs in aquatic environments, confirming that biofilms are a significant sink for ARGs in the estuarine environment.

Behavior of antibiotic resistance genes under extremely high-level antibiotic selection pressures in pharmaceutical wastewater treatment plants

Pharmaceutical wastewater treatment plants (PWWTPs), which receive wastewater containing extremely high levels of antibiotics, are regarded as potential hot spots for antibiotic-resistance development in the environment. Six sampling campaigns in six PWWTPs in Southeastern China were carried out to assess the prevalence and fate of antibiotic resistance genes (ARGs). Different genes were monitored in different PWWTPs (PWWTP A: lincosamides; PWWTP B: aminoglycosides and macrolides; PWWTP C: quinolones; PWWTP D: macrolides and quinolones; PWWTP E: cephalosporins; and PWWTP F: quinolones and macrolides) using real-time quantitative polymerase chain reactions (PCRs), according to the antibiotic type produced. The levels of typical ARG subtypes in the final effluents ranged from (1.03±0.91)×101 to (6.78±0.21)×107copies/mL. The absolute abundance of ARGs in effluents accounted for 0%–577% of influents to the six PWWTPs with a median value of 6%. Most of the ARGs are transported to the dewatered sludge, with concentrations from (1.38±0.21)×105 to (6.84±0.43)×1010copies/g dry weight (dw). In different treatment units (before/after biological units), a clear trend of proliferation or attenuation was not observed for the ARGs, aside from a strong attenuation in moving bed bio-film reactor (MBBR) in PWWTP C. Through correlation analyses, this study demonstrated that the bacterial abundance and antibiotic concentrations within the PWWTPs influenced the fate of the associated ARGs, and this was possibly related primarily to the intrinsic resistance mechanisms of corresponding ARGs. Macrolide ARGs, which tend to locate in plasmids and transposons, positively correlate weakly with total macrolide antibiotic concentrations but positively correlate strongly with 16S rRNA concentrations. Furthermore, ARG concentrations in the wastewater from fermentation were significantly higher than in the wastewater from chemical synthesis and preparation. This is the first comprehensive study on the behavior of antibiotic resistance genes under extremely high-level antibiotic selection pressures in pharmaceutical wastewater treatment plants (PWWTPs) in Southeastern China.

Evaluation of the antibiotics effects on the physical and chemical parameters during the co-composting of sewage sludge with palm wastes in a bioreactor

The objective of this study was to investigate thermal and physicochemical parameters of sewage sludge-palm waste mixtures contaminated by different families of antibiotics (tetracyclines, macrolides and fluoroquinolones) during co-composting. Sludge was spiked with chlortetracycline (CTC), oxytetracycline (OTC), roxithromycin (RXY), enrofloxacin (ENR) and ciprofloxacin (CIP). Antibiotics were spiked at a low level, medium level, high level and a control without antibiotics was conducted. The results showed that the organic matter degradation was delayed and the carbon/nitrogen (C/N) ratio was affected by an increase of the antibiotics concentration. The presence of antibiotics, especially at high level, delayed the coming of the temperature maxima, and disturbed the thermophilic phase. The calorific model showed that the heat release is affected during the thermophilic phase when high antibiotics concentrations were used. In addition, the microbiological approach showed that the adsorption of antibiotics on the rachis could be probably responsible of the fungi inhibition especially during the maturation phase. Therefore, the medium and high levels of antibiotics affected the thermal, physical and chemical parameters as well as the compost quality.

Diagnostic performance and clinical feasibility of a point-of-care test for respiratory viral infections in primary health care.

BackgroundInappropriately high levels of antibiotics are still prescribed in primary health care for respiratory tract infections (RTIs). Access to diagnostic point-of-care tests (POCTs) for RTIs might reduce this over-prescription.ObjectiveThe purpose of our study was to determine the diagnostic performance and clinical feasibility of a recently developed diagnostic POCT for respiratory viruses, the mariPOC®, in a Dutch primary healthcare setting.MethodsIn patients with RTI symptoms presenting to a family practice during the 2015–2016 winter season, we determined the test’s sensitivity and specificity relative to polymerase chain reaction (PCR) testing performed in a laboratory. The clinical feasibility of the POCT was evaluated by interviewing general practitioners (GPs).ResultsOne or more respiratory viruses were detected in 54.9% of the patients (n = 204). For influenza A virus (n = 24), sensitivity of the POCT was 54.2% and specificity was 98.9%; for influenza B virus (n = 18), sensitivity was 72.2% and specificity 99.5%; and for respiratory syncytial virus (RSV) (n = 12), sensitivity was 50.0% and specificity 100%. In samples with higher viral load, sensitivity was 85.7% for influenza A, 78.6% for influenza B and 85.7% for RSV. The availability of a diagnostic test for respiratory viruses was appreciated by both patients and GPs.ConclusionsOur study shows that diagnostic POCTs for respiratory viruses might contribute to a precise and evidence-based diagnosis of RTIs and could positively influence prescription of antibiotics by GPs. However, before implementation in primary healthcare, diagnostic accuracy of the POCT needs improvement and it is impact on clinical decision making should be further assessed.

Removal mechanisms for extremely high-level fluoroquinolone antibiotics in pharmaceutical wastewater treatment plants.

Pharmaceutical wastewater treatment plants (PWWTPs) receive industrial effluents from the plant that contain extremely high levels of antibiotics and are regarded as one of the major sources of antibiotics in the environment. Two PWWTPs have been selected in Zhejiang Province, China, to assess the removal mechanisms of fluoroquinolone antibiotics (FQs). PWWTP A uses activated sludge with biocarriers in a moving bed biofilm reactor in anoxic and aerobic units, and PWWTP B uses biological units under anaerobic, aerobic, and anoxic conditions. The wastewater samples and solid samples (sludge and suspended solid matter) were analyzed using solid-phase extraction and ultra-performance liquid chromatography-mass spectrometry. Ofloxacin (OFX) was detected in each stage of PWWTP A, and enrofloxacin and ciprofloxacin were detected in PWWTP B. The concentrations of FQs ranged from 0.32μg/L to 5.7mg/L. Although the FQs were largely removed in the biological units (94.5 to 99.9%), large amounts were still discharged in the final effluent (up to 88.0±7.0μg/L) and dewatered sludge (up to 0.85±0.24mg/kg). Mass balance analyses of samples from PWWTP A indicated that biodegradation (93.8%) was the major mechanism responsible for the removal of OFX, whereas the contribution of sorption by sludge (0.79%) was less significant, deviating from the findings of most similar studies. Using linear analysis and correlation analysis, we found that the log10 values of the FQ concentration in the sludge were positively related with the log10 values of the equilibrium concentration in water (C w ). These relationships can be described by a Freundlich-like equation. However, these relationships were negative when the C w values were high. Our preliminary explanation is that the equilibrium C w plays an important role in controlling the sorption behavior of FQs in activated sludge.