Zn3(BTC)2

Two different zinc-based metal-organic frameworks (MOFs) were investigated to remove one of the most used fluoroquinolone antibiotic, Ofloxacin (OFL), from polluted water. The most common zeolitic imidazolate framework-8 (ZIF-8) and the green Zn(II) and benzene-1,3,5-tri-carboxylate (Zn3(BTC)2) were prepared through a facile synthetic route and characterized by means of Fourier-Transform Infrared (FT-IR) Spectroscopy, X-ray Powder Diffraction (XRPD), and Scanning Electron Microscopy (SEM) analyses. The two MOFs were compared in terms of both adsorption and kinetic aspects under real conditions (tap water, natural pH). Results showed that OFL was adsorbed in remarkable amounts, 95 ± 10 and 25.3 ± 0.8 mg g-1 on ZIF-8 and Zn3(BTC)2, respectively, following different mechanisms. Specifically, a Langmuir model well described the ZIF-8 profile, while for Zn3(BTC)2, cooperative adsorption occurred. Moreover the kinetic results were quite different, pseudo-second-order and sigmoidal, respectively. The suitability of ZIF-8 and Zn3(BTC)2 as adsorbent phases for water depollution was tested on tap water samples spiked with OFL 10 µg L-1. The obtained removal efficiencies, of 88% for ZIF-8 and 72% for Zn3(BTC)2, make these materials promising candidates for removing fluoroquinolone antibiotics (FQs) from polluted waters, notwithstanding their limited reusability in tap water, as demonstrated by in-depth characterization of the two MOFs after usage.

Price Differences Between Otic and Ophthalmic Drops

OBJECTIVE

Otic drops are one of the most frequently prescribed medications in otolaryngology. However, some forms of these drops can be very expensive, and ophthalmic formulations are sometimes used by practitioners to decrease the cost for their patients. The goal of this study is to determine the cost differential between otic and ophthalmic drops.

METHODS

Pharmacies in New York City, Chicago, and Portland were surveyed in the span of 6 weeks by telephone to evaluate the current prices of various otic and ophthalmic drops commonly prescribed by otolaryngologists.

RESULTS

A total of 83 pharmacies were surveyed. Surveyed drugs included ciprofloxacin/dexamethasone (cip/dex) otic, neomycin/polymyxin B sulfates/hydrocortisone (neo/poly/HC) otic, acetic acid (AA) otic, acetic acid/hydrocortisone (AA/HC) otic, ofloxacin otic, ofloxacin ophthalmic, and tobramycin/dexamethasone (tob/dex) ophthalmic. Per milliliter, cip/dex otic was consistently the most expensive, with a median price of $38.00 per milliliter. Among the antibiotic drops, neo/poly/HC otic was the least expensive formulation with a median price of $11.60 per milliliter. Ofloxacin ophthalmic was significantly less expensive than the otic formulation, at $11.00 and $31.00 per milliliter, respectively (adjusted p < 0.001). In general, otic and ophthalmic formulations were not significantly different according to manufacturing information, although ophthalmic drops were more often packaged in a sterile fashion and with less abrasive ingredients for use in the more sensitive tissue of the eye.

CONCLUSION

Significant and meaningful price differences exist between otic and ophthalmic drops. Given the safety of ophthalmic drops used in the ears, they may be a more cost-effective alternative to traditionally prescribed otic drops when clinically appropriate.

Kelp-derived N-doped biochar activated peroxymonosulfate for ofloxacin degradation

N-doped carbon materials have been proven to be effective catalysts for activating peroxymonosulfate (PMS). Marine algae biomass is rich in nitrogenous substances , which can reduce the cost of N-doping process and can obtain excellent N-doped catalysts cheaply and easily. In this study, kelp biomass was selected to prepare N-doped kelp biochar (KB) materials. The high defect degree, high specific surface area, and participation of graphite N make KB have excellent catalytic degradation ability. The KB degraded 40 mg/L ofloxacin (OFL) close to 100% within 60 min, applied with PMS. Through quenching experiments and electron paramagnetic resonance spectroscopy, the degradation process dominated by non-radical pathways was determined. At the same time, O2·- and 1O2 were closely related, and a significant impact of quenching O2·- on the reaction was observed. The non-radical approach made the system excellent performance over a wide pH range and in the presence of multiple anions. The experiments of reusability confirmed the stability of the material. Its catalytic performance was restored after low-temperature pyrolysis. This research supports the use of endogenous nitrogen in biomass. It provides more options for advanced oxidation process application and marine resource development.

Multi-catalysis induced by pulsed discharge plasma coupled with graphene-Fe3O4 nanocomposites for efficient removal of ofloxacin in water: Mechanism, degradation pathway and potential toxicity

Herein, degradation of ofloxacin (OFX) by pulsed discharge plasma (PDP) coupled with multi-catalysis using graphene-Fe₃O₄ nanocomposites was inspected. The graphene-Fe₃O₄ nanocomposites were prepared by hydrothermal synthesis, and their morphology, specific surface area, chemical bond structure and magnetic property were characterized systematically. Compared with sole Fe₃O₄, the specific surface area of graphene-Fe₃O₄ nanocomposites increased from 26.34 m²/g to 125.04 m²/g. The prepared graphene-Fe₃O₄ nanocomposites had higher paramagnetism and the magnetic strength reached 66.05 emu/g, which was prone to separate from solution. Graphene-Fe₃O₄ nanocomposites could further accelerate OFX degradation compared to sole Fe₃O₄. When graphene content was 18 wt%, graphene-Fe₃O₄ nanocomposites exhibited the highest catalytic activity, and the removal efficiency of OFX enhanced from 65.0% (PDP alone) to 99.9%. 0.23 g/L dosage and acid solution were beneficial for OFX degradation. Higher stability of graphene-Fe₃O₄ nanocomposites could be maintained although four times use. Graphene-Fe₃O₄ nanocomposites could catalyze H₂O₂ and O₃ to produce more ·OH. The degradation products of OFX were identified by liquid chromatography mass spectrometry (LC-MS) and ion chromatography (IC). According to the identified products and discrete Fourier transform (DFT), the degradation pathway was inferred. Further toxicity assessment of products manifested that the toxicity of oral rat 50% lethal dose (LD₅₀) and the developmental toxicity of OFX were reduced.

Degradation of ofloxacin using peroxymonosulfate activated by nitrogen-rich graphitized carbon microspheres: Structure and performance controllable study

Nitrogen-rich graphitized carbon microspheres (NGCs) with hierarchically porous were constructed by self-assembly. Under different heat treatment conditions, the structure, morphology and properties of NGCs were studied by using multiple characterization techniques. The results showed that the chemical microenvironments (e.g. surface chemistry, degree of graphitization and defective, etc.) and microstructures properties (e.g. morphology, specific surface area, particle size, etc.) could be delicately controlled via thermal carbonization processes. The degradation of ofloxacin (OFLX) by NGCs activated peroxymonosulfate (PMS) was studied systematically. It was found that the synergistic coupling effect between optimum N or O bonding species configuration ratio (graphitic N and C=O) and special microstructure was the main reason for the enhanced catalytic activity of NGC-800 (calcination temperature at 800°C). Electron paramagnetic resonance (EPR) experiments and radical quenching experiments indicated that the hydroxyl (^•OH), sulfate (SO₄^•-) and singlet oxygen (¹O₂) were contributors in the NGC-800/PMS systems. Further investigation of the durability of chemical structures and surface active sites revealed that undergo N bonding species configuration reconstruction and cannibalistic oxidation during PMS activation reaction. The used NGC-800 physicochemical properties could be recovered by heat treatment to achieve the ideal catalytic performance. The findings proposed a valuable insight for catalytic performance and controllable design of construction.

Ofloxacin adsorptive interaction with rice husk ash: Parametric and exhausted adsorbent disposability study

The present study investigates the adsorptive interaction of rice husk ash (RHA) with Ofloxacin (OFL) antibiotic. The OFL loaded RHA was studied for its disposability by solidification to find its possible use as a building material. Further, toxicity analysis of leachate from the solidified RHA was also studied for probable leaching of OFL. The effects of adsorption parameters such as initial pH, the dosage of RHA (m), initial OFL concentration (C₀), and contact time (t) on the responses % OFL removal (X₁) and adsorption capacity (mg/g) (X₂) were evaluated using the central composite design (CCD) based on response surface method (RSM). Kinetic and thermodynamic studies were performed at optimized parameters, and adsorption equilibrium data were illustrated by using Langmuir, Redlich-Peterson (R-P), and Tempkin isotherm models. Optimum condition was found as m = 7.94 g/L, t = 430 min and pH = 6, and at this actual responses X₁ and X₂ were evaluated as 79.71% and 6.28 mg/g, respectively. Pseudo-first-order kinetic fitted best for the adsorption kinetic data. Toxicity analysis of leachate from solidified RHA indicated that most of the OFL was encapsulated inside the cement and the OFL present in leachate is not sufficient to eradicate the growth of E.coli and Bacillus subtilis.

Removal of ofloxacin with biofuel production by oleaginous microalgae Scenedesmus obliquus

Microalgae-based technology is an environmental-friendly and cost-effective method for biofuel production and pollutants removal. In this study, Scenedesmus obliquus (S. obliquus) was cultured with varying concentrations of ofloxacin (OFL) in BG11 medium. In the algae-antibiotics culture system, S. obliquus could effectively remove OFL with a concentration of 10 mg/L; however, the removal efficiency was restricted under higher doses (20-320 mg/L). Meanwhile, the lipid content significantly increased by 21.10-49.63%, which was caused by carbon being converted from carbohydrate to lipid. The greatest lipid productivity (7.53 mg/L/d) occurred at an OFL concentration of 10 mg/L, which was approximately 1.5-fold greater than the control. Moreover, S. obliquus cultured with OFL was able to improve the biodiesel quality due to an increase of saturated fatty acids and a decrease of unsaturated fatty acids. This study demonstrates that an algae-antibiotics system is a promising solution to simultaneously achieve antibiotics removal and biofuel production.

Application of a thermo-sensitive imprinted SERS substrate to the rapid trace detection of ofloxacin

A novel composite (AgNPs-MIPs) was prepared by combining nano-silver particles with an ofloxacin (OFL) imprinted thermo-sensitive hydrogel. The thermo-sensitive optical properties of the composite were studied and it was used as a Raman substrate for the detection of ofloxacin. The results have shown that the position and intensity of the plasmon resonance absorption peak of the AgNPs-MIPs can be reversibly changed with the change of temperature, and the intensity of the ofloxacin Raman signal increases with the increase of temperature. Because the hydrogel combined Raman enhancement of silver nanoparticles, the selectivity of molecularly imprinted materials and the intelligent response of thermo-sensitive hydrogels, it can realize rapid, in situ, trace and selective detection of ofloxacin. Moreover, the detection limit can reach 10^-10 mol L^-1.

Acceleration of goethite-catalyzed Fenton-like oxidation of ofloxacin by biochar

While carbon materials have been well studied to stimulate the homogeneous Fenton-like processes, little was known about their impacts on iron mineral-catalyzed heterogeneous Fenton-like reactions. Here, it was found that biochar prepared at 300 °C or 600 °C (BC300 or BC600) greatly stimulated the degradation of ofloxacin (OFX) in a goethite (Gt)-mediated Fenton-like system. In 4 h, while only 38.4 % and 48.4 % OFX were removed in Gt/H₂O₂ and BC600/H₂O₂ systems, the removal efficiency reached over 94.0 % in Gt/BC600/H₂O₂ system. And the pseudo-first-order rate constant of Gt/H₂O₂, BC600/H₂O₂ and Gt/BC600/H₂O₂ systems were 0.12, 0.16 and 0.72 h^-1, respectively, indicating the occurrence of synergistically catalytic degradation. •OH was identified as the major oxidant. Both the •OH yield and the H₂O₂ utilization efficiency of Gt/BC600/H₂O₂ system were higher than those of Gt/H₂O₂ and BC600/H₂O₂ systems. BC600 showed better stimulation effects than BC300. The persistent free radicals (PFRs) of BC could activate H₂O₂ and partly contribute to •OH production in the Gt/BC/H₂O₂ system. While BC could not directly reduce Fe(III) in Gt, it improved the cycling of Fe(III)/Fe(II) through complexing Fe(III) with its carboxyl group. Potential pathways were proposed for OFX degradation in the Gt/BC/H₂O₂ system.

A novel mouse model of chronic suppurative otitis media and its use in preclinical antibiotic evaluation

Chronic suppurative otitis media (CSOM) is a neglected pediatric disease affecting 330 million worldwide for which no new drugs have been introduced for over a decade. We developed a mouse model with utility in preclinical drug evaluation and antimicrobial discovery. Our model used immune-competent mice, tympanic membrane perforation and inoculation with luminescent Pseudomonas aeruginosa that enabled bacterial abundance tracking in real-time for 100 days. The resulting chronic infection exhibited hallmark features of clinical CSOM, including inhibition of tympanic membrane healing and purulent ear discharge. We evaluated the standard care fluoroquinolone ofloxacin and demonstrated that this therapy resulted in a temporary reduction of bacterial burden. These data are consistent with the clinical problem of persistent infection in CSOM and the need for therapeutic outcome measures that assess eradication post-therapeutic endpoint. We conclude that this novel mouse model of CSOM has value in investigating new potential therapies.

Accumulation characteristics and biological response of ginger to sulfamethoxazole and ofloxacin

The potential risk to human health of antibiotics that pass through the food chain has become an important global issue, but there are few reports on the response of ginger (Zingiber officinale) to antibiotic pollution. In this study, we investigated the enrichment characteristics and biological response of ginger to sulfamethoxazole (SMZ) and ofloxacin (OFL) residues, which are common in the environment. Lower levels of SMZ, OFL and their combined duplex treatment (SMZ+OFL) promoted the growth of ginger, but the critical doses necessary to stimulate growth differed among treatments: 10 mg L-1 SMZ, 1 mg L-1 OFL and 1 mg L-1 (SMZ+OFL) had the strongest stimulating effects. At higher dosages, the root growth and light energy utilization efficiency of ginger were impaired, and (SMZ+OFL) had the strongest inhibitory effect. Treatments with lower levels of antibiotics had no significant effect on reactive oxygen species and antioxidant enzyme activities. However, when SMZ, OFL and SMZ+OFL concentrations exceeded 10 mg L-1, the contents of H2O2, O2- and MDA continued to increase, while the activities of SOD, POD, CAT first increased and then decreased, especially in SMZ+OFL. Ginger accumulated more SMZ and OFL in rhizomes and less in leaves, and accumulation increased significantly as antibiotic concentration increased. When SMZ concentration was 1 mg L-1, the SMZ concentrations in rhizomes, roots, and leaves were 0.23, 0.15, and 0.05 mg kg-1, respectively, and the residual SMZ in the rhizome was 2.3 times higher than the maximum residue limit. The abundance of the resistance genes sul1, sul2, qnrS, and intI1 increased with increasing antibiotic concentrations, and intI1 abundance was the highest. OFL induced higher levels of intI1 expression than did SMZ.

Fe3O4@S-doped ZnO: A magnetic, recoverable, and reusable Fenton-like catalyst for efficient degradation of ofloxacin under alkaline conditions

In this study, an efficient and reusable heterogeneous Fenton catalyst Fe₃O₄@S-doped ZnO magnetic composite was synthesized for the degradation of ofloxacin (OFX) under alkaline conditions without external energy input. The Fe₃O₄@S-doped ZnO exhibited excellent catalytic activity toward ofloxacin degradation within 120 min. Using 0.25 g/L of catalyst and 5.0 mL/L of H₂O₂ under optimized conditions, the catalyst was effective in pH values ranging from 5.2 to 9.0. The catalytic performance at optimal conditions was in accordance with a pseudo-first-order kinetics model. The reaction constant of Fe₃O₄@S-doped ZnO (0.0354 min^-1) was three times than that of Fe₃O₄@ZnO (0.0124 min^-1) under alkaline conditions (pH 8.2). The reactive oxygen species were the ·OH and O₂^·-, with ·OH dominating in the degradation of OFX. It is proposed that the catalyst acts as a Lewis acid, creating an acidic microenvironment on the catalyst's surface and widening the pH range of the Fenton reaction to alkaline conditions. Additionally, the catalyst was stable and reusable after six cycles of use. The Fenton-like Fe₃O₄@S-doped ZnO catalyst overcomes the problem of the narrow pH of the reaction system, thus providing promising environmental applications.

Significant enhancement of photo-Fenton degradation of ofloxacin over Fe-Dis@Sep due to highly dispersed FeC6 with electron deficiency

An efficient strategy for enhancing iron efficiency in heterogeneous Fenton reaction via the pyrolysis of ferrocene chemically modified sepiolite (Sep) was proposed in this study. Highly dispersed FeC₆ on sepiolite (Fe-Dis@Sep) was synthesized as an efficient photo-Fenton catalyst for the visible light degradation of ofloxacin (OFX). It exhibits an excellent Fenton activity and stability towards OFX degradation. The pseudo-first order reaction rate constant of Fe-Dis@Sep was 5.1-fold higher than that of the supported catalyst with aggregated iron oxides prepared by traditional impregnation method (Fe-Agg@Sep). Based on TEM images and density functional theory (DFT) calculation, the enhanced Fenton activity of Fe-Dis@Sep was attributed to the unique incorporation of FeC₆ on Sep via Si-O-C-Fe bond which not only favor the high dispersion of FeC₆ with an electron deficiency but also promote Fe(III) to Fe(II) cycle via the formation of surface Fe-H₂O₂ complex. OH and O₂^- were identified as active species for OFX degradation in Fe-Dis@Sep-H₂O₂-Vis system. 98.7% of F and 97.0% of N in OFX was converted into F^- and NO₃^- with a TOC removal efficiency of 89.35%. The possible degradation pathway of OFX was also proposed according to HPLC-MS results. Finally, the Fenton reaction mechanism over Fe-Dis@Sep was discussed.

Quinolone-induced psychosis: an updated review

Quinolones are an antibiotic group widely used due to their antimicrobial action and security profile, however, it has been described neuropsychiatric adverse effects, being induced-psychotic episodes one of the most clinically relevant. Nevertheless, this secondary effect has been scarcely studied. A literature search using PRISMA guidelines was performed between 01/01/1962 and 01/31/2019 on PubMed and ScienceDirect, including manuscripts which described substance-induced psychotic disorder according to DSM-5 and in which the symptomatology was not attributable to an acute confusional state (delirium) or to other induced psychiatric disorders. 459 articles were found, but only 27 manuscripts fulfilled inclusion criteria (n=27 patients, median age of 36.15±16.96 years). Ciprofloxacin, levofloxacin and ofloxacin were the main antibiotics implicated. Quinolone- induced psychosis is a clinical relevant issue due to the high prescription of these antibiotics and the severity of this clinical syndrome. In general, this syndrome can remit in a few days with the withdrawal of the quinolone and performing symptomatic support if it is necessary. Finally, it is important to perform further research on this issue. Keywords: Quinolones, Psychosis, Ciprofloxacin, Levofloxacinn, Psychotic Induced.

Occurrence and distribution of priority pharmaceuticals in the Yellow River and the Huai River in Henan, China

The occurrence and spatial distribution of priority pharmaceuticals (PPs) in water samples from the Yellow River and the Huai River in the Henan region of China were investigated in this study. The concentration of the total PPs (ΣPPs; sum of the 10 observed PPs) ranged from not detected to 3474 ng L^-1 in samples from the Yellow River and from 4.35 to 146 ng L^-1 in samples from the Huai River. The level of the ΣPPs in the Huai River was much lower than that found in the Yellow River. The composition of the PPs differed between the two rivers. Norfloxacin, carbamazepine, and 5,5-diphenylhydantoin were detected at high concentrations in the Yellow River, whereas sulfamethazine, ampicillin trihydrate, carbamazepine, and 5,5-diphenylhydantoin were the dominant species in the Huai River, suggesting there were different pollution sources. In comparison to other studies around China, most of the PPs in water samples from the Yellow River and the Huai River were at low concentrations, except for norfloxacin and ofloxacin. There were significant seasonal variations among the PPs in water samples from the Huai River, whereas spatial distinctions were recorded among the PPs in the Yellow River. Dissolved organic carbon content did not correlate with the PPs in the studied area.

Ultraviolet/peroxydisulfate degradation of ofloxacin in seawater: Kinetics, mechanism and toxicity of products

The ultraviolet/peroxydisulfate (UV/PDS) system was used to degrade ofloxacin (OFL) in fresh water, synthetic marine aquaculture water and synthetic seawater. The comparison of the reaction degradation rate constants proved that the order of reaction rate was the following: synthetic seawater (0.77 min^-1) > synthetic marine aquaculture water (0.74 min^-1) > freshwater (0.30 min^-1). Bromide (Br^-) and bicarbonate (HCO₃^-) promote the degradation of OFL, whereas chloride (Cl^-) inhibits the degradation. The piperazine ring of OFL was the main reactive group, and atoms N1, C6, C7 and N2 were identified as the reaction sites. Based on the intermediate and final products, the possible degradation pathways of OFL in the three kinds of water were proposed. Additionally, during the UV/PDS treatment of synthetic marine aquaculture water containing Cl^- and Br^-, the oxidation products of OFL showed a slight toxicity to Chlorella pyrenoidosa (C. pyrenoidosa) and Priacanthus tayenus (P. tayenus). The maximum growth inhibition rate of the products to C. pyrenoidosa was 9.72%. The products also caused liver cells of P. tayenus to be damaged and reduced the species richness and diversity of intestinal microorganism. Nevertheless, compared with the products degraded by traditional disinfection methods using NaClO, the biological toxicities were much lower. UV/PDS can be used for seawater as a new alternative disinfection method.

Influence of pH and DO on the ofloxacin degradation in water by UVA-LED/TiO2 nanotube arrays photocatalytic fuel cell: mechanism, ROSs contribution and power generation

The influence of pH and dissolved oxygen (DO) on the degradation of ofloxacin (OFX) in water by UVA-LED/TiO₂ nanotube arrays photocatalytic fuel cell (UVA-LED/TNA PFC) was investigated. The degradation pathway depended on the location of OFX frontier orbital with different ionization states and the role of reactive oxidative species (ROSs) played with varied pH and DO values. In presence of DO, the quencher tests revealed that O₂^- played a key role at pH 3.0, 7.0 and 11.0, while OH made its greatest contribution at pH 3.0 and the effect of h⁺ was largely inhibited at pH 11.0. Hydroxylation for cationic OFX was more significant, while demethylation and piperazinyl ring oxidation for anionic OFX occurred more quickly compared to other forms. Besides, zwitterionic OFX underwent decarboxylation and combination of demethylation & hydroxylation more easily. Much higher power generation was observed in presence of DO at pH 7.0, probably due to the enhanced adsorption of OFX on the TNA, and DO could amplify the electric potential between the two electrodes. The degradation efficiencies were almost the same in presence or absence of DO, but the pathways were different and e-_aq may replace O₂- as the leading ROSs in absence of DO.

Linking microbial diversity and population dynamics to the removal efficiency of pharmaceutically active compounds (PhACs) in an anaerobic/anoxic/aerobic (A2O) system

The removal efficiencies (REs) of nineteen pharmaceutically active compounds (PhACs) (six antibiotics-clarithromycin, ofloxacin, sulfadiazine, sulfamethazine, sulfamethoxazole and trimethoprim -, four β-blockers -atenolol, metoprolol, propranolol and sotalol-, two antihypertensives/diuretics -furosemide and hydrochlorothiazide-, three lipid regulators -bezafibrate, fenofibrate and gemfibrozil-, and four psychiatric medications -carbamazepine, diazepam, lorazepam and paroxetine) were ascertained in a pilot-scale anaerobic/anoxic/aerobic (A²O) system treating urban wastewater, long term operated during two experimental phases using different sets of environmental conditions and operating parameters. Illumina MiSeq sequencing was used to investigate the structure, diversity and population dynamics of bacteria, archaea and fungi communities in the activated sludge. The results showed that mixed liquor suspended solids (MLSS) and food-to-microorganisms ratio (F/M) were operational parameters significantly influencing the REs of five of the analyzed PhACs in the A²O system. Biota-environment (BIO-ENV) analysis revealed strong correlations between population shifts of the activated sludge community and the REs of PhACs of the different pharmaceutical families. Increased REs of clarithromycin, furosemide, bezafibrate and gemfibrozil were concomitant to higher relative abundances of bacterial phylotypes classified within the Rhodobacteraceae and Sphingomonadaceae (Alphaproteobacteria), while those of Betaproteobacteria, Chloroflexi and Methanomethylovorans (Euryarchaea) correlated positively with the REs of up to seven PhACs belonging to different therapeutic groups.

Effects of Thermal Treatment on Porous Cerium Titanate Photocatalyst for Ofloxacin Degradation

Cetyltrimethyl ammonium bromide (CTAB) template was used in a sol-gel route to synthesize porous cerium titanate. The fractions of CeTi₂O₆, CeO₂, anatase TiO₂ and rutile TiO₂ phases in the materials vary with calcination temperature ranging from 600 to 1000 °C. FT-Far IR spectra prove the far infrared absorption of Ce-O and Ti-O bonds in the materials. The band gap energies of the crystallized materials are around 3.0 eV and are not noticeably affected by calcination temperature. The BET surface area constantly shrinks from 65.4 m²/g at 600 °C to 2.1 m²/g at 1000 °C. Meanwhile, the total pore volume decreases from 0.2057 cm³/g at 600 °C to 0.0024 cm³/g at 1000 °C. The adsorption capacity of the materials drastically decreases with increasing calcination temperature, which is in close relationship to the change of BET surface area. The porous cerium titanate sample obtained at 800 °C has the maximum photocatalytic activity on both ofloxacin degradation and hydroxyl radical productivity. When calcination temperature increases from 600 °C to 800 °C, photocatalytic degradation efficiency is enhanced from 31.2% to 56.7%.

Degradation of Ofloxacin by Perylene Diimide Supramolecular Nanofiber Sunlight-Driven Photocatalysis

This study describes a promising sunlight-driven photocatalyst for the treatment of ofloxacin and other fluoroquinolone antibiotics in water and wastewater. Perylene diimide (PDI) supramolecular nanofibers, which absorb a broad spectrum of sunlight, were prepared via a facile acidification polymerization protocol. Under natural sunlight, the PDI photocatalysts achieved rapid treatment of fluoroquinolone antibiotics, including ciprofloxacin, enrofloxacin, norfloxacin, and ofloxacin. The fastest degradation was observed for ofloxacin, which had a half-life of 2.08 min for the investigated conditions. Various light sources emitting in the UV-vis spectrum were tested, and blue light was found to exhibit the fastest ofloxacin transformation kinetics due to the strong absorption by the PDI catalyst. Reactive species, namely, h⁺, ¹O₂, and O₂^•-, comprised the primary photocatalytic mechanisms for ofloxacin degradation. Frontier electron density calculations and mass spectrometry were used to verify the major degradation pathways of ofloxacin by the PDI-sunlight photocatalytic system and identify the transformation products of ofloxacin, respectively. Degradation mainly occurred through demethylation at the piperazine ring, ketone formation at the morpholine moiety, and aldehyde reaction at the piperazinyl group. An overall mechanism was proposed for ofloxacin degradation in the PDI-sunlight photocatalytic system, and the effects of water quality constituents were examined to determine performance in real water/wastewater systems. Ultimately, the aggregate results from this study highlight the suitability of the PDI-sunlight photocatalytic system to treat antibiotics in real water and wastewater systems.

Surface Facet of CuFeO2 Nanocatalyst: A Key Parameter for H2O2 Activation in Fenton-Like Reaction and Organic Pollutant Degradation

The development of efficient heterogeneous Fenton catalysts is mainly by "trial-and-error" concept and the factor determining H₂O₂ activation remains elusive. In this work, we demonstrate that suitable facet exposure to elongate O-O bond in H₂O₂ is the key parameter determining the Fenton catalyst's activity. CuFeO₂ nanocubes and nanoplates with different surface facets of {110} and {012} are used to compare the effect of exposed facets on Fenton activity. The results indicate that ofloxacin (OFX) degradation rate by CuFeO₂ {012} is four times faster than that of CuFeO₂ {110} (0.0408 vs 0.0101 min^-1). In CuFeO₂ {012}-H₂O₂ system, OFX is completely removed at a pH range 3.2-10.1. The experimental results and theoretical simulations show that ^•OH is preferentially formed from the reduction of absorbed H₂O₂ by electron from CuFeO₂ {012} due to suitable elongation of O-O (1.472 Å) bond length in H₂O₂. By contrast, the O-O bond length is elongated from 1.468 to 3.290 Å by CuFeO₂ {110} facet, H₂O₂ tends to be dissociated into -OH group and passivates {110} facet. Besides, the new formed ≡Fe²⁺* on CuFeO₂ {012} facet can accelerate the redox cycle of Cu and Fe species, leading to excellent long-term stability of CuFeO₂ nanoplates.

Oxygen Vacancy Promoted Heterogeneous Fenton-like Degradation of Ofloxacin at pH 3.2-9.0 by Cu Substituted Magnetic Fe3O4@FeOOH Nanocomposite

To develop an ultraefficient and reusable heterogeneous Fenton-like catalyst at a wide working pH range is a great challenge for its application in practical water treatment. We report an oxygen vacancy promoted heterogeneous Fenton-like reaction mechanism and an unprecedented ofloxacin (OFX) degradation efficiency of Cu doped Fe₃O₄@FeOOH magnetic nanocomposite. Without the aid of external energy, OFX was always completely removed within 30 min at pH 3.2-9.0. Compared with Fe₃O₄@FeOOH, the pseudo-first-order reaction constant was enhanced by 10 times due to Cu substitution (9.04/h vs 0.94/h). Based on the X-ray photoelectron spectroscopy (XPS), Raman analysis, and the investigation of H₂O₂ decomposition, ^•OH generation, pH effect on OFX removal and H₂O₂ utilization efficiency, the new formed oxygen vacancy from in situ Fe substitution by Cu rather than promoted Fe³⁺/Fe²⁺ cycle was responsible for the ultraefficiency of Cu doped Fe₃O₄@FeOOH at neutral and even alkaline pHs. Moreover, the catalyst had an excellent long-term stability and could be easily recovered by magnetic separation, which would not cause secondary pollution to treated water.

Alternative pre-approved and novel therapies for the treatment of anthrax

BACKGROUND

Bacillus anthracis, the causative agent of anthrax, is a spore forming and toxin producing rod-shaped bacterium that is classified as a category A bioterror agent. This pathogenic microbe can be transmitted to both animals and humans. Clinical presentation depends on the route of entry (direct contact, ingestion, injection or aerosolization) with symptoms ranging from isolated skin infections to more severe manifestations such as cardiac or pulmonary shock, meningitis, and death. To date, anthrax is treatable if antibiotics are administered promptly and continued for 60 days. However, if treatment is delayed or administered improperly, the patient's chances of survival are decreased drastically. In addition, antibiotics are ineffective against the harmful anthrax toxins and spores. Therefore, alternative therapeutics are essential. In this review article, we explore and discuss advances that have been made in anthrax therapy with a primary focus on alternative pre-approved and novel antibiotics as well as anti-toxin therapies.

METHODS

A literature search was conducted using the University of Manitoba search engine. Using this search engine allowed access to a greater variety of journals/articles that would have otherwise been restricted for general use. In order to be considered for discussion for this review, all articles must have been published later than 2009.

RESULTS

The alternative pre-approved antibiotics demonstrated high efficacy against B. anthracis both in vitro and in vivo. In addition, the safety profile and clinical pharmacology of these drugs were already known. Compounds that targeted underexploited bacterial processes (DNA replication, RNA synthesis, and cell division) were also very effective in combatting B. anthracis. In addition, these novel compounds prevented bacterial resistance. Targeting B. anthracis virulence, more specifically the anthrax toxins, increased the length of which treatment could be administered.

CONCLUSIONS

Several novel and pre-existing antibiotics, as well as toxin inhibitors, have shown increasing promise. A combination treatment that targets both bacterial growth and toxin production would be ideal and probably necessary for effectively combatting this armed bacterium.

Assessing the potential of pharmaceuticals and their transformation products to cause mutagenic effects: Implications for gene expression profiling

The selection and prioritization of pharmaceuticals and their transformation products for evaluating effects on the environment and human health is a challenging task. One common approach is based on compounds (e.g., mixture composition, concentrations), and another on biology (e.g., relevant endpoint, biological organizational level). Both of these approaches often resemble a Lernaean Hydra-they can create more questions than answers. The present study embraces this complexity, providing an integrated approach toward assessing the potential effects of transformation products of pharmaceuticals by means of mutagenicity, estrogenicity, and differences in the gene expression profiles. Mutagenicity using the tk kinase assay was applied to assess a list of 11 priority pharmaceuticals, namely, atenolol, azithromycin, carbamazepine, diclofenac, ibuprofen, erythromycin, metoprolol, ofloxacin, propranolol, sulfamethoxazole, and trimethoprim. The most mutagenic compounds were found to be β-blockers. In parallel, the photolabile pharmaceuticals were assessed for their mixture effects on mutagenicity (tk assay), estrogenicity (T47D- KBluc assay), and gene expression (microarrays). Interestingly, the mixtures were mutagenic at the µg/L level, indicating a synergistic effect. None of the photolysed mixtures were statistically significantly estrogenic. Gene expression profiling revealed effects related mainly to certain pathways, those of the p53 gene, mitogen-activated protein kinase, alanine, aspartate, and glutamate metabolism, and translation-related (spliceosome). Fourteen phototransformation products are proposed based on the m/z values found through ultra-performance liquid chromatography-tandem mass spectrometry analysis. The transformation routes of the photolysed mixtures indicate a strong similarity with those obtained for each pharmaceutical separately. This finding reinforces the view that transformation products are to be expected in naturally occurring mixtures. Environ Toxicol Chem 2016;35:2753-2764. © 2016 SETAC.

Impacts of urbanization on the prevalence of antibiotic-resistant Escherichia coli in the Chaophraya River and its tributaries

River water samples were taken from 32 locations around the basin of Chaophraya River and its four major tributaries in Thailand to investigate resistance ratios of Escherichia coli isolates to eight antibiotic agents of amoxicillin, sulfamethoxazole/trimethoprim, tetracycline, doxytetracycline, ciprofloxacin, levofloxacin, norfloxacin and ofloxacin. Principal component analysis was performed to characterize resistance patterns of the samples. Relevancy of the obtained principal components with urban land use and fecal contamination of the river were examined. The ratio of antibiotic-resistant bacteria is likely to increase when urban land use near the sampling site exceeds a certain ratio. The resistance ratio to fluoroquinolones tends to be high in a highly populated area. Meanwhile, no significant contribution of fecal contamination was found to increase the resistance ratio. These results suggest that an antibiotic-resistance ratio is dependent on conditions of local urbanization rather than the upstream conditions, and that the major sources of antibiotic-resistant bacteria in the Chaophraya River basin are possibly point sources located in the urban area which contains a high ratio of resistant bacteria.

The occurrence and removal of selected fluoroquinolones in urban drinking water treatment plants

Fluoroquinolones (FQs) are a widely prescribed group of antibiotics. They enter the aqueous environment, where they are frequently detected, and can lead to a threat to human health. Drinking water treatment plants (DWTPs) play a key role in removing FQs from potable water. This study investigated the occurrence and removal of four selected FQs (norfloxacin (NOR), ciprofloxacin (CIP), enrofloxacin (ENR), and ofloxacin (OFL)) in three urban DWTPs in China. The treatment efficacy for each system was simultaneously evaluated. Two of the examined DWTPs used conventional treatment processes. The third used conventional processes followed by additional treatment processes (ozonation-biologically activated carbon (ozonation-BAC) and membrane technology). The average concentrations of the four FQs in the source water and the finished water ranged from 51 to 248 ng/L and from <5 to 46 ng/L, respectively. Based on residual concentrations, the conventional treatment system had a low removal of FQs. In contrast, the addition of advanced treatment processes such as the ozonation-BAC and membranes, substantially improved the removal of FQs. The finding of this study has important implications: even though coagulation-sedimentation and chlorination treatment processes can remove most target FQs, the typical practice of advanced treatment processes is necessary for the further removal.

[Distribution Characteristics of Fluoroquinolones Antibiotics in Surface Water and Groundwater from Typical Areas in A City]

In order to investigate the characteristics of 5 typical kinds of fluoroquinolones (FQs) pollution in waters from a city, surface water and groundwater samples from main drainage rivers and typical areas were collected, respectively. The conventional test and FQs concentrations analysis of the water samples were conducted. The results showed the concentration and composition of FQs in groundwater differed substantially from those in surface water. The average concentration of FQs in surface water was 789.1 ng x L(-1) with the main components of ofloxacin (OFL) and lomefloxacin (LOM). This value was higher than the average concentration of FQs in groundwater: 342.7 ng x L(-1) with the main components of norfloxacin (NOR) and lomefloxacin (LOM). The enrofloxacin (ENR) exhibited relatively lower levels in both surface water and groundwater as compared to others. The highest FQs concentrations in surface water were found in trenches, followed by tributaries and the main stream. For groundwater, FQs concentrations were relatively higher in the sewage riverside. A decreasing trend of FQs concentration was monitored with the increasing distance of sampling points to the drainage rivers and all components mentioned above showed similar changing trends. The results of this study preliminarily indicated that FQs in groundwater along the riverside probably came from the surface water.

Biotransformation of fluoroquinolone antibiotics by ligninolytic fungi--Metabolites, enzymes and residual antibacterial activity

A group of white rot fungi (Irpex lacteus, Panus tigrinus, Dichomitus squalens, Trametes versicolor and Pleurotus ostreatus) was investigated for the biodegradation of norfloxacin (NOR), ofloxacin (OF) and ciprofloxacin (CIP). The selected fluoroquinolones were readily degraded almost completely by I. lacteus and T. versicolor within 10 and 14 d of incubation in liquid medium, respectively. The biodegradation products were identified by liquid chromatography-mass spectrometry. The analyses indicated that the fungi use similar mechanisms to degrade structurally related antibiotics. The piperazine ring of the molecules is preferably attacked via either substitution or/and decomposition. In addition to the degradation efficiency, attention was devoted to the residual antibiotic activities estimated using Gram-positive and Gram-negative bacteria. Only I. lacteus was able to remove the antibiotic activity during the course of the degradation of NOR and OF. The product-effect correlations evaluated by Principal Component Analysis (PCA) enabled elucidation of the participation of the individual metabolites in the residual antibacterial activity. Most of the metabolites correlated with the antibacterial activity, explaining the rather high residual activity remaining after the biodegradation. PCA of ligninolytic enzyme activities indicated that manganese peroxidase might participate in the degradation.

[Contamination characteristics of fluoroquinolones in different kinds of soil profiles in Southeast suburb of Beijing]

Eighty-six soil samples were collected using Geoprobe soil sampler from 11 borehole profiles of Beijing Southeast suburb. The sampling sites could be divided into 8 kinds of landuse. Physical and chemical properties of samples were analyzed. The concentrations of 5 fluoroquinolones (FQs) were analyzed by the high-performance liquid chromatography. Results show that the average value of total concentrations of 5 FQs is 46.1 μg x kg(-1). Ofloxacin (OFL) is the predominant among them, and then is norfloxacin (NOR). Last comes to enrofloxacin (ENR), ciprofloxacin (CIP) and lomefloxacin (LOM). There are significant differences in FQs concentrations and kinds among the 8 land use types of soil profiles. The average value of total concentrations of 5 FQs decrease with an increasing of soil depth. The average concentration of OFL, NOR, LOM and ENR decrease with an increasing of soil depth. But CIP has the opposite result. Based on FQs concentrations from 42 soil samples with a depth among 0 to 3 meters, contamination characteristics of FQs were analyzed by fuzzy hierarchial clustering. Sampling sites of vegetable greenhouse, woods, sewage irrigation zone, groundwater irrigation zone, livestock and poultry farm, sediments from sewage river have similar components and contents of FQs, with less kinds and low concentration. In contrast, sampling sites of pharmaceutical enterprises and refuse landfill have more kinds and medium concentration of FQs.

Solar photocatalytic ozonation of a mixture of pharmaceutical compounds in water

Aqueous solutions of mixtures of four pharmaceutical compounds (atenolol, hydrochlorothiazide, ofloxacin and trimethoprim) both in Milli-Q ultrapure water and in a secondary effluent from a municipal wastewater treatment plant have been treated at pH 7 by different oxidation methods, such as conventional ozonation, photolytic ozonation, TiO2 catalytic ozonation, TiO2 photocatalytic oxidation and TiO2 photocatalytic ozonation. Experiments were carried out using a solar compound parabolic concentrator. The performance results have been compared in terms of removal of emerging contaminants (ECs), generation rate of phenolic intermediates, organic matter mineralization, ecotoxicity removal and enhancement of biodegradability. Also, the consumption of ozone to achieve certain treatment goals (95% removal of ECs and 40% mineralization) is discussed. Results reveal that solar photocatalytic ozonation is a promising oxidation method as it led to the best results in terms of EC mineralization (∼85%), toxicity removal (∼90%) and efficient use of ozone (∼2mgO3mgEC(-1) to achieve complete EC removal and ∼18mgO3mgTOC(-1) to achieve 40% EC mineralization, respectively).

[Efficacy and safety of levofloxacin in patients with nursing and healthcare-associated pneumonia]

Levofloxacin (LVFX) is one of respiratory quinolones with wide spectrum of antimicrobial efficacy for Gram-positive and -negative bacteria and also atypical bacteria, and 500 mg of intravenous LVFX infusion has recently been able to use once daily based on pharmacokinetics-pharmacodynamics in Japan. So far, there had been no reports of the prospective studies evaluating efficacy and safety of LVFX in patients with nursing and healthcare-associated pneumonia (NHCAP). This study was conducted to evaluate prospectively the efficacy and safety of LVFX in patients with NHCAP categories B and C (other antibacterial agents were allowed to use with LVFX) according to Japanese guideline for NHCAP by the Japanese Respiratory Society (JRS). LVFX 500 mg was intravenously administered once daily, and the clinical efficacy and safety were evaluated by clinical symptoms, peripheral blood laboratory findings and chest X-rays. Sixty-two patients (average age was 81.2 years old, female/male was 22/40) were firstly registered and evaluated for the safety of LVFX, and eventually 54 patients were enrolled for the evaluation of clinical efficacy of LVFX. The percentage of these 54 patients aged over 65 years old was 96.3%, NHCAP category B/C was 33/21. The efficacy of LVFX in all 54 patients evaluated was 85.2% (categories B/C of NHCAP was 81.8/90.5%). In addition, the efficacies of LVFX in each pneumonia severity category by A-DROP system by JRS in NHCAP patients were 100% in mild, 86.7% in moderate, 77.8% in severe/very severe. Nine patients (2 with liver dysfunction, 6 with renal dysfunction and 1 with thrombocytopenia) out of 62 patients were reported to have possible adverse effects of LVFX. All of the patients with liver and renal dysfunctions after starting LVFX administration demonstrated mild dysfunctions and continued LVFX treatment, and these dysfunctions normalized soon after cessation of LVFX. LVFX was changed to other antibacterial agent in one patient with thrombocytopenia, and also thrombocytopenia was normalized thereafter. In conclusion, LVFX is effective and relatively safe for categories B and C in patients with NHCAP.

In vitro evaluation of IgE-mediated hypersensitivity reactions to quinolones

BACKGROUND

  Hypersensitivity IgE-mediated reactions to quinolones are not easy to diagnose, with skin testing inducing false positive results. The aim of the study was to evaluate the in vitro-specific IgE response in patients with immediate allergic reactions to quinolones.

METHODS

  We evaluated 38 patients with confirmed immediate allergic reactions to quinolones. Those with anaphylaxis were considered allergic by clinical history, once other possible causes were ruled out, and those with urticaria by drug provocation. Sepharose-radioimmunoassay (RIA) and basophil activation test (BAT) with ciprofloxacin, moxifloxacin and levofloxacin were performed.

RESULTS

  The quinolones involved were moxifloxacin (N = 24), ciprofloxacin (N = 11) and levofloxacin (N = 3). Sepharose-RIA was positive in 12 cases (31.57%) and BAT in 27 (71.05%). With Sepharose-RIA, 8 (21%) were positive to ciprofloxacin, 7 (18.4%) to moxifloxacin and 7 (18.4%) to levofloxacin. With BAT, 23 (60.5%) were positive to ciprofloxacin, 12 (31.6%) to moxifloxacin and 8 (21%) to levofloxacin. The specificity of the Sepharose-RIA was demonstrated by inhibition tests. To confirm that the BAT results observed were IgE mediated, the PI3K inhibitor wortmannin was used, with this compound inhibiting the BAT when stimulated with anti-IgE and the different quinolones, but not when fMLP was used as the basophil stimulator. Sepharose-RIA and BAT were repeated in positive cases 1 year later, detecting a decrease in all cases, with four becoming negative.

CONCLUSION

  Immediate hypersensitivity reactions to quinolones do occur, with moxifloxacin being the drug most frequently involved. The BAT is a useful method for diagnosing patients. Specific IgE was demonstrated by Sepharose-RIA and inhibition assay.

Novel lipophilic 7H-pyrido[1,2,3-de]-1,4-benzoxazine-6-carboxylic acid derivatives as potential antitumor agents: improved synthesis and in vitro evaluation

A convenient route for the synthesis of some acyloxymethyl esters and carboxamides of levofloxacin (LV) with modulated lipophilicity is described. The synthesized compounds were evaluated in vitro for their growth inhibitory effect in five human cancer cell lines. The most efficient LV derivatives (ester 2e and amide 4d) displayed IC(50) values in the 0.2-2.2 μM range, while IC(50) values for parent LV ranged between 70 and 622 μM depending on the cell line. The esters displayed no in vivo toxicity up to 80 mg/kg when administered intraperitoneally. This study thus shows that LV analogs displayed antitumor efficacy, at least in vitro, a feature that appeared to be independent from the lipophilicity of the grafted substituent.

Surveillance of drug-resistant tuberculosis in the state of Gujarat, India

BACKGROUND

Limited information about the prevalence of drug-resistant tuberculosis (TB) has been reported from India, the country with the world's highest burden of TB. We conducted a representative state-wide survey in the state of Gujarat (2005 population: 56 million).

METHODS

Mycobacterium tuberculosis isolates from a representative sample of new and previously treated smear-positive pulmonary TB (PTB) cases were subjected to drug susceptibility testing (DST) against first-line drugs at a World Health Organization supranational reference laboratory. Isolates found to have at least both isoniazid (INH) and rifampicin (RMP) resistance (i.e., multidrug-resistant TB [MDR-TB]) were subjected to second-line DST.

RESULTS

Of 1571 isolates from new patients, 1236 (78.7%) were susceptible to all first-line drugs, 173 (11%) had any INH resistance and MDR-TB was found in 37 (2.4%, 95%CI 1.6-3.1). Of 1047 isolates from previously treated patients, 564 (54%) were susceptible to all first-line drugs, 387 (37%) had any INH resistance and MDR-TB was found in 182 (17.4%, 95%CI 15.0-19.7%). Among 216 MDR-TB isolates, 52 (24%) were ofloxacin (OFX) resistant; seven cases of extensively drug-resistant TB (XDR-TB) were found, all of whom were previously treated cases.

CONCLUSION

MDR-TB prevalence remains low among new TB patients in Gujarat, but is more common among previously treated patients. Among MDR-TB isolates, the alarmingly high prevalence of OFX resistance may threaten the success of the expanding efforts to treat and control MDR-TB.

Biofilm Formation on Hydrophilic Intraocular Lens Material

PURPOSE

To estimate bacterial biofilm formation on the hydrophilic acrylic (hydrogel) intraocular lens (IOL) Meridian (HP60M, Baush & Lomb) and to investigate a preventive effect against biofilm formation of hydrogel IOLs presoaked in antibiotics.

METHODS

Two Staphylococcus epidermidis strains, ATCC 12228 and ATCC 35984 (biofilm-producer), and an Enterococcus faecalis strain (KOS1, clinical isolate from an endophthalmitis patient) were used. Biofilms were cultivated on disks of different IOL materials: hydrogel, PMMA (polymethylmethacrylate), and acrylic. Biofilms were stained with crystal violet (CV), which served as an index of biofilm formation. The bacterial population was enumerated after biofilm homogenization. Biofilms were also examined by scanning electron microscopy (SEM). IOLs were presoaked in two antibiotics, levofloxacin (LVFX) and gatifloxacin (GFLX), and then the bacterial population was enumerated. As in vivo experiment, antibiotics-treated and nontreated Meridian IOLs were implanted in rabbit eyes, which served as an endophthalmitis model, and the bacterial population was enumerated.

RESULTS

The amount of biofilm formed was the least on hydrogel from among the three materials tested after 48- and 72-hr incubation (p < 0.05 to 0.01). The bacterial population was the least on hydrogel from among the three materials with ATCC 12228 (p < 0.05 to 0.01), and the bacterial population was significantly different between hydrogel and acrylic after 72-hr incubation with ATCC 35984 (p < 0.05). Biofilm by the two S. epidermidis strains were recognized after 24-hr incubation. Rates of biofilm-positive SEM fields, which were defined as being occupied by biofilm over at least half of the area, were increased through 72 hr with ATCC 35984. While the E. faecalis strain showed no bacterial adherence on the antibiotics-treated hydrogel IOLs, adherence of the S. epidermidis strain, ATCC 35984 was recognized on the LVFX-treated IOLs after 48-hr incubation (103 to 104 CFU/ml). In the rabbit in vivo model, the bacterial populations in eyes with an antibiotics-treated Meridian IOL were significantly smaller than in eyes with a nontreated IOL for 72 hr after surgery (p < 0.05 to 0.01).

CONCLUSIONS

The biofilm formation was less on hydrogel than on other two materials tested. Hydrogel presoaked in antibiotics exhibited a preventive effect against biofilm formation at least for 24 hr in vitro and against bacterial proliferation in the rabbit in vivo endophthalmitis model.

Use of intravenous immunoglobulin for the treatment of severe Clostridium difficile colitis

BACKGROUND

Clostridium difficile is a gram-positive, anaerobic, spore-forming, rod-shaped bacterium responsible for most of the hospital-acquired diarrhea in developed countries. The organism received its name because it was difficult to isolate and grow in culture. Infections in the elderly have been associated with significant morbidity and mortality as well as prolonged hospitalization.

CASE SUMMARY

A 72-year-old white male presented with a 5-day history of abdominal pain, nausea, and severe diarrhea but no fever or chills. He had had recent chemotherapy for Merkel cell carcinoma of the right ear. Medical history included hypothyroidism for 10 years and non-Hodgkin's lymphoma in remission for 4 years after a stem cell transplant. The patient was receiving oral vancomycin, levofloxacin, thyroxine, and esomeprazole. He had severe infection secondary to chemotherapy for Merkel cell carcinoma; in addition, he had failed to respond to metronida-zolc and vancomycin treatment, with the resulting development of colon dilatation and hypoalbuminemia. Colonoscopy showed severe ulceration with inflammation suggestive of severe persistent colitis. At that point, the patient was given 1 dose of IV immunoglobulin (IVIG) 400 mg/kg; vancomycin treatment was continued. Two days after IVIG therapy, the patient's diarrhea improved, with complete resolution after 6 days; bowel dilatation resolved completely after 7 days; and oral intake improved after 2 days. The patient continued on a tapering dose of vancomycin for 6 weeks. He was discharged home and had no recurrence despite antibiotic use for pseudomonas and staphylococcus bacteremia.

CONCLUSIONS

Severe C difficile colitis has been reported more frequently in the literature recently, especially in elderly patients. Tissue culture assay is the best diagnostic test to detect the cytotoxin; enzyme immunoassay is the test used in most hospitals, but it has a sensitivity of only -75%. Treatment options remain limited to eradicate this serious infection. Antibiotic therapy, infection control measures, and early diagnosis are essential components of successful outcome for this disease. This patient's infection resolved with the addition of IVIG with no recurrence, suggesting the possible benefit of this treatment in certain patients with severe colitis who do not respond to standard therapy.

[Present possibilities of Q fever therapy.]

The first-line therapy for acute Q fever is 14 to 21 days of doxycycline, or fluoroquinolones such as ofloxacin or pefloxacin. Clarithromycin is a potential effective alternative. Chronic Q fever, especially endocarditis, requires treatment for at least 18 months, with the preferred combination of doxycycline and hydroxychloroquine. An alternative treatment for chronic Q fever, when adverse effects of hydroxychloroquine are a problem, is the combination of doxycycline and fluoroquinolones with extended therapy for 3 years or more. Serologic tests may be used to monitor the response to therapy.

A retrospective study of endophtalmitis rates comparing quinolone antibiotics

PURPOSE

To compare endophthalmitis rates between topical quinolone antibiotics over a four-year period in a university setting.

DESIGN

Retrospective, cross-sectional (prevalence) study.

METHODS

STUDY POPULATION

Nine thousand seventy-nine patients who underwent a phacoemulsification procedure at a University Eye Center.

INTERVENTIONS

The following interventions were conducted: use of a nosocomial infectious reporting database retrospective analysis of prospectively collected data to establish endophthalmitis rates; prevalence analysis of postoperative quinolone antibiotics; analysis of endophthalmitis rate vs postoperative quinolone prescribed.

MAIN OUTCOME MEASURES

Occurrence of endophthalmitis after cataract surgery.

RESULTS

During a four-year period involving 9079 phacoemulsification procedures, 26 cases of bacterial postoperative endophthalmitis were reported (rate = 0.286%). Eight of the 26 cases were considered complicated; 18 cases were uncomplicated. Among cases performed during this period, postoperative prescription volumes for ciprofloxacin (Ciloxan, Alcon Laboratories, Inc., Fortworth, Texas) and ofloxacin (Ocuflox, Allergan, Inc., Irvine, California) antibiotic drops were nearly identical, with 4538 patients receiving ciprofloxacin (49.98%) and 4541 patients receiving ofloxacin (50.02%). There were 22 endophthalmitis patients (85%) who had used topical ciprofloxacin and 4 patients (15%) who had used topical ofloxacin postoperatively. The difference in infectious rates between antibiotics was highly significant (P < .00026). For uncomplicated cases, 14 patients received ciprofloxacin and 4 patients received ofloxacin. This difference was also significant (P < .015).

CONCLUSIONS

Differences in pharmacokinetic and pharmacodynamic properties exist among quinolone antibiotics, which may affect endophthalmitis incidence following cataract surgery.

Acquisition of quinolone resistance and point mutation of the gyrA gene in Campylobacter jejuni isolated from broilers and in vitro-induced resistant strains

A dramatic rise in the number of resistant Campylobacter to quinolones has been documented in human patients and domestic animals. In this study, the mechanism of acquisition of quinolone resistance was studied by detecting point mutations in the gyrA gene of Campylobacter strains obtained from broilers and strains with in vitro-induced resistance. The minimal inhibitory concentrations (MICs) of norfloxacin (NFLX) and ofloxacin (OFLX) for the strains that had no point mutation were slightly increased from the source strain (Campylobacter jejuni ATCC 33560). The MICs of nalidixic acid (NA), NFLX, and OFLX for the strains that had the point mutation at Thr-86 were 100 or 200 microg/ml, 50 microg/ml, and 25 microg/ml, respectively. The MIC of NA for the strain that had a point mutation at Asp-90 higher than those for the strains that had the point mutation at Thr-86, but the MICs of NFLX and OFLX were relatively lower than those for the strains that had point mutation at Thr-86. These findings suggest that the degree of antimicrobial resistance against NA, NFLX, and OFLX in the in vitro-induced C. jejuni strains was associated with the location of the point mutation in gyrA. On the other hand, a point mutation in all seven resistant strains isolated from broilers was located only at Thr-86, while the MICs of the three quinolones varied in each wild strain. This suggests that another mechanism might also be involved in the acquisition of quinolone resistance in C. jejuni wild strains.

Clinical progression and viral load in a community outbreak of coronavirus-associated SARS pneumonia: a prospective study

BACKGROUND

We investigated the temporal progression of the clinical, radiological, and virological changes in a community outbreak of severe acute respiratory syndrome (SARS).

METHODS

We followed up 75 patients for 3 weeks managed with a standard treatment protocol of ribavirin and corticosteroids, and assessed the pattern of clinical disease, viral load, risk factors for poor clinical outcome, and the usefulness of virological diagnostic methods.

FINDINGS

Fever and pneumonia initially improved but 64 (85%) patients developed recurrent fever after a mean of 8.9 (SD 3.1) days, 55 (73%) had watery diarrhoea after 7.5 (2.3) days, 60 (80%) had radiological worsening after 7.4 (2.2) days, and respiratory symptoms worsened in 34 (45%) after 8.6 (3.0) days. In 34 (45%) patients, improvement of initial pulmonary lesions was associated with appearance of new radiological lesions at other sites. Nine (12%) patients developed spontaneous pneumomediastinum and 15 (20%) developed acute respiratory distress syndrome (ARDS) in week 3. Quantitative reverse-transcriptase (RT) PCR of nasopharyngeal aspirates in 14 patients (four with ARDS) showed peak viral load at day 10, and at day 15 a load lower than at admission. Age and chronic hepatitis B virus infection treated with lamivudine were independent significant risk factors for progression to ARDS (p=0.001). SARS-associated coronavirus in faeces was seen on RT-PCR in 65 (97%) of 67 patients at day 14. The mean time to seroconversion was 20 days.

INTERPRETATION

The consistent clinical progression, shifting radiological infiltrates, and an inverted V viral-load profile suggest that worsening in week 2 is unrelated to uncontrolled viral replication but may be related to immunopathological damage.

Biocompatibility of silver nitrate and ofloxacine coated bioabsorbable SR-PLLA rods

The purpose of this study was to evaluate the biocompatibility of silver nitrate and ofloxacine coatings of bioresorbable self-reinforced poly-L-lactic acid (SR-PLLA) rods. SR-PLLA rods coated with pure poly(caprolactone-co-L-lactide) or blended with silver nitrate (10, 5 or 2 weight-%) or ofloxacine (5 or 2 weight-%) were implanted in the dorsal muscles of 25 male rabbits. Tissue reactions caused by implantation trauma were seen 1 week after implantation. The positive control and 10 w-% silver nitrate coating showed the most marked reactions 1 month after implantation. Only sparse reactions were seen 6 months after implantation. Tissue reactions were scored semi-quantitatively. As a result of this study, we concluded that silver nitrate or ofloxacine coatings up to five w-% did not alter the good biocompatibility of SR-PLLA essentially. The method may lead to the possibility of preventing bacterial adhesion to urological stents during insertion.

Viridans streptococcal bacteraemia due to penicillin-resistant and penicillin-sensitive streptococci: analysis of risk factors and outcome in 60 patients from a single cancer centre before and after penicillin is used for prophylaxis

60 patients with 60 viridans streptococcal bacteraemic episodes (42 due to penicillin-sensitive and 18 due to penicillin-resistant viridans streptococci) were analysed in a population of 12,185 admissions and 1,380 bacteraemic episodes during a 7-year period in a National Cancer Institute. The incidence of viridans streptococci among bacteraemias decreased from 11.5% in 1989 to 2.5% in 1995 after penicillin was introduced for prophylaxis of febrile neutropenia in acute leukaemia in 1993. However, the proportion of penicillin-resistant viridans streptococcal bacteraemias increased from 0 in 1989 and 1990 before any prophylaxis was given, to 12.9-16.7% after quinolones were used for prophylaxis in 1991 and 1992, and to 44.4-81.8% in 1993-1995 after penicillin was added to the quinolones. Mortality rate was higher in the subgroup of penicillin-resistant viridans streptococcal bacteraemias (p < 0.05). Statistically significant risk factors in patients with penicillin-resistant (compared with penicillin-sensitive) viridans streptococcal bacteraemia were: acute leukaemia (p < 0.03), high doses of cytarabine (p < 0.05), mucocutaneous lesions (p < 0.004), breakthrough bacteraemia during prophylaxis with ofloxacine plus penicillin (p < 0.001). Multiple logistic regression analysis showed that only acute leukaemia (OR 2.05, CI 0.85-1.85, p < 0.00452) and penicillin-resistance (OR 0.71, CI 0.103-4.887, p < 0.0209) were significant independent predictors of inferior outcome. Breakthrough bacteraemia during empiric therapy with vancomycine occurred in 5 of 116 patients treated with vancomycine, and during therapy with ampicillin plus gentamicin in 6 patients of 18 treated.

Effect of Mao-bushi-saishin-to on infection of ofloxacin resistant bacteria and of unknown origin

When seven elderly patients with fever due to bacterial infection failed to respond to ofloxacin 300 mg/day for 3 days, we prescribed Mao-bushi-saishin-to for 7 days. Bushi, one of the components of Mao-bushi-saishin-to, is a complex of various alkaloids, which is known to stimulate the conducting system of the heart, so half of the standard dose was prescribed for these patients. We assessed changes in the patients' body temperatures and serum C-reactive protein concentrations. As a result, the patients' body temperatures all fell to under 37 degrees C and C-reactive protein levels decreased from an average of 3.06 mg/dl to an average of 0.36 mg/dl (P< 0.02). In cases where a fever does not decrease through dosage of an antibiotic such as ofloxacin after about 3 days, half of the standard dose of Mao-bushi-saishin-to for 7 days should be considered as a complementary therapy.