High Ciprofloxacin Research Articles

Contribution of gyrA and qnrA genes in Ciprofloxacin Resistant Ecsherichia coli Isolates from Patients with Urinary Tract Infections of Imam Khomeini Hospital of Tehran

Background: Resistance to ciprofloxacin as the most common antibiotic for the treatment of urinary tract infections (UTIs) is increasing. In this study, the role of gyrA and qnrA genes among ciprofloxacin resistant Escherichia coli (E. coli) isolates from UTIs was evaluated. Methods: During September to March 2014, urine samples were collected from patients with UTIs of Imam Khomaini hospital of Tehran. Bacterial identification was done based on standard tests. The antibiotic sensitivity test was performed based on the clinical and laboratory standards institute (CLSI) 2014 protocol and minimal inhibitory concentration (MIC) of ciprofloxacin was determined by E-test strips. DNA was extracted by the boiling method and assessment of gyrA (DNA gyrase (type II topoisomerase)) and qnrA genes was done by the polymerase chain reaction (PCR). Further sequencing was done for PCR confirmation and blasting. Results: All isolates were susceptible to carbapenems (100%) and 98.7% were susceptible to nitrofrontain. The highest resistance was towards piperacillin 85%, ampicillin 83.8%, sulfamethoxazole trimethoprim (SXT) 78.7%, ciprofloxacin 77.5%, and 75% tetracycline. Around 80% of the E. coli isolates were identified as multi drug resistant (MDR). All isolates with MIC of ≥ 4 μg/mL for ciprofloxacin were the candidates for DNA extraction, PCR, and sequencing. The gyrA and qnrA genes were detected in 100% and 39% of isolates, respectively. Mutations were found in the sequence analysis, yet the mean full change was related to change of serine to leucine at position 83 (S 83 L). Conclusions: Finally, contribution of both mutated chromosomal gyrA genes and plasmidic qnrA resistance genes in some of the high ciprofloxacin resistant bacterial strains was found in this study, besides the overuse of antibiotics, which can increase the emergence of resistant strains.

Assessment of ecotoxicological effects of ciprofloxacin in Daphnia magna: life-history traits, biochemical and genotoxic effects.

Antibiotics (e.g. ciprofloxacin) have been detected in surface water and groundwater for several decades. In order to understand the potential impact of the continuous exposure of aquatic organisms to ciprofloxacin, a chronic assay was carried out with Daphnia magna. This approach allowed evaluation of the effects of ciprofloxacin on life-history and sub-individual parameters (antioxidant status and metabolic response: activities of catalase and glutathione S-transferases - GSTs; peroxidative damage; thiobarbituric acid reactive substances and genotoxic effects (genetic damage index, measured by the comet assay). Life-history parameters of D. magna showed no significant effects after ciprofloxacin exposure. Concerning oxidative stress and metabolism parameters, no significant alterations were reported for catalase and GSTs activities. However, a dual response was observed, with a significant decrease in lipid peroxidation levels at low ciprofloxacin concentrations (<0.013 mg/L), while a significant increase was verified at high ciprofloxacin concentrations (0.078 mg/L). The genotoxicity assay detected a significant increase in genetic damage index up to 0.013 mg/L of ciprofloxacin. The here-tested ciprofloxacin concentrations, which are ecologically relevant, did not cause significant impacts concerning the life-history parameters of D. magna; however, at the same levels of ciprofloxacin an oxidative stress and genotoxic damage scenarios were recorded.

The clinical significance of silent mutations with respect to ciprofloxacin resistance in MRSA.

BackgroundThe aim of this study was to investigate the genotypic differences between different sequence type MRSA isolates, especially focusing on silent rpoB474 mutations and the relationship between such mutations and ciprofloxacin resistance.MethodsSeventy-nine MRSA isolates were obtained for antibiotic susceptibility tests and molecular study.ResultsAmong these isolates, we found that the MIC50, MIC90, and minimum inhibitory concentration (MIC) range of ciprofloxacin were much higher for the isolates without the rpoB474 mutation than for isolates with the rpoB474 mutation. A total of 87.5% of the isolates with the rpoB474 mutation were susceptible to ciprofloxacin, but none of the isolates without the rpoB474 mutation were susceptible to ciprofloxacin. For 27 MRSA isolates without rpo474 silent mutation but with gyrA86/126 silent mutation, all of them belonged to SCCmec III, and had high ciprofloxacin MIC levels. For another 44 MRSA isolates with rpo474 silent mutation but without gyrA86/126 silent mutation, all of them showed low ciprofloxacin MIC levels, all of them belonged to either SCCmec IV or V. Furthermore, MRSA ciprofloxacin resistance was found to be associated with the mutations gyrA S84L/parC S80F or gyrA S84L, and S85P/parC S80Y.ConclusionMost occurrences of this rpoB474 silent mutation were found in community acquired-MRSA (CA-MRSA) isolates with susceptibility to most antibiotics, especially for ciprofloxacin and vice versa. Thus, this mutation may help to differentiate the different microbiologic characteristics of MRSA clinical isolates.

ZIF-67 derived hollow cobalt sulfide as superior adsorbent for effective adsorption removal of ciprofloxacin antibiotics

The hollow nanostructures receive increasing attention in recent years. In particular, the confined cavity in the hollow nanostructures can function as a carrier for loading target molecules, whereas the porous walls are beneficial for shortening the transport distance of target molecules from solution to surface of adsorbent, making it possible to achieve high adsorption capacity with short adsorption time. Here, the hollow Co3S4 was synthesized by using ZIF-67 as template and thioacetamide as sulfide reagent through a simple solvothermal method, and characterized by SEM, TEM, HRTEM, XRD, FT-IR, zeta potential measurement, TG, N2 adsorption-desorption and XPS analysis. The adsorption performance of hollow Co3S4 for ciprofloxacin (CIP) antibiotics was evaluated in neutral aqueous solution. The equilibrium adsorption data were well fitted by Langmuir model, and a high maximum CIP adsorption capacity of 471.7 mg g−1 was obtained. The relatively high correlation coefficient of Tempkin model (r2 = 0.960) indicated a stronger electrostatic interaction between CIP and hollow Co3S4, which was consistent with the observation from the effects of pH and ionic strength. Result of adsorption kinetic investigation indicated fast CIP adsorption by hollow Co3S4. The adsorption kinetics follows the pseudo-second-order kinetic model and liquid-film diffusion model. CIP adsorption by hollow Co3S4 was hardly affected by humic acid. Further, the hollow Co3S4 exhibited no obvious loss in CIP removal after recycling for five times. The result displays an important environmental significance of hollow Co3S4 for CIP sequestration, in particular in wastewater, where CIP antibiotics are only slightly transformed or even unchanged.

Intraspecific variability of ciprofloxacin accumulation, tolerance, and metabolism in Chinese flowering cabbage (Brassica parachinensis)

To investigate the mechanism of genotype differences in ciprofloxacin (CIP) accumulation, this study was designed to compare the tolerance and metabolic responses to CIP exposure between low (Cutai) and high (Sijiu) CIP-accumulation cultivars of Brassica parachinensis. Decreases in biomass and chlorophyll content were significantly greater (p < 0.05) and toxicities were more severe within cell ultrastructures of Cutai compared to Sijiu. A sequential growth test also revealed that Sijiu was more tolerant to CIP stress compared to Cutai. Meanwhile, significantly higher (p < 0.05) root parameters and higher areas of the stele and xylem may be responsible for the increased uptake and transport of CIP in Sijiu. Ultra performance liquid chromatography-electrospray ionization tandem mass spectrometry (UPLC–ESI-MS/MS) analysis revealed that CIP was metabolized to three major metabolites by the hydroxylation and breakdown of the piperazinyl substituent in the CIP molecule. The enhanced metabolic transformation of CIP in Sijiu indicated a more efficient capacity to detoxify, which in turn favored an increased accumulation of CIP in this cultivar. Thus, the present study demonstrated that the stronger tolerance and metabolism of Sijiu to CIP were responsible for its high CIP accumulation, suggesting an evolutionary mechanism for adaptation to environmental stress.

Genetic diversity and clonal characteristics of ciprofloxacin-resistant Campylobacter jejuni isolated from Chilean patients with gastroenteritis

Campylobacter jejuni is a major cause of acute gastroenteritis worldwide. However, it has also been associated with other diseases such as bacteremia and with several post-infection sequelae. Although campylobacteriosis is usually a self-limited infection, antibiotics are indicated for severe and chronic conditions. Unfortunately, several industrialised nations have reported a substantial increase in antibiotic resistance of C. jejuni. However, there is still a lack of knowledge about the epidemiology of resistance developed by this pathogen in the developing world. For this reason, our objective was to determine the resistance of clinical C. jejuni strains to ciprofloxacin and erythromycin in Chile and their associated genotypes.Fifty C. jejuni isolates recovered from fecal samples of people with acute gastroenteritis, in central and southern Chile between 2006 and 2015, were analysed. Resistance to erythromycin and ciprofloxacin was assessed by disk diffusion and agar dilution methods. Furthermore, these strains were genotyped by Multilocus Sequence Typing (MLST).Only one of the isolates was resistant to erythromycin. However, 48% of them were resistant to ciprofloxacin. The minimal inhibitory concentration of these ciprofloxacin-resistant isolates was in the range between 4 and 32 μg/ml. Moreover, MLST analyses showed that most ciprofloxacin-resistant strains were grouped into three dominant clonal complexes (ST-21, ST-48 and ST-353), while the unique strain resistant to both antibiotics belonged to the ST-45 complex. Our results evidence a high ciprofloxacin resistance and suggest that there is a dissemination of resistant clonal lineages responsible for cases of campylobacteriosis in Chile. Further studies should elucidate the origin of these resistant genotypes.

Glyoxylamide-based self-assembly hydrogels for sustained ciprofloxacin delivery

In this study, we report the synthesis of glyoxylamide peptide-mimics as self-assembled gels with well-defined molecular structures for topical delivery of ciprofloxacin (CIP). The glyoxylamide peptide mimics successfully formed hydrogels with critical gel concentrations of 0.02-0.08% (w/v). The mechanical strength, secondary structure, and fiber morphology of these hydrogels can be modulated by varying the N-substituent of the ring-opened isatins. The synthesised hydrogel exhibited a high loading capacity of CIP (40% (w/w)) and a sustained release profile. The CIP-loaded hydrogels were able to release CIP for more than 15 days and the released solution was shown to retain activity against Gram-positive and Gram-negative bacteria. In addition, the hydrogels formed showed low toxicity against Cos7 cells.

Successful outpatient management of Campylobacter fetus bacteremia in an immunocompetent patient with endovascular involvement.

We describe a case of Campylobacter fetus bacteremia with endovascular involvement in an immunocompetent female patient. The patient was treated with high dose ciprofloxacin as an outpatient and recovered well.

Aspects of urinary tract infections and antimicrobial resistance in hospitalized urology patients in Asia: 10-Year results of the Global Prevalence Study of Infections in Urology (GPIU).

To assess Asian data from Global Prevalence Study on Infections in Urology (GPIU study) which has been performed more than 10 years. Seventeen Asian countries participated in the GPIU study between 2004 and 2013. Data for these countries were collected from the web-based GPIU database. The point prevalence of urinary tract infections (UTI) and antimicrobial susceptibility of representative pathogens were analysed for Asian geographic regions. A total of 6706 patients (5271 male, 1435 female) were assessed during the study period, and 659 patients were diagnosed with a UTI (9.8%). Of these UTI patients, 436 were male and 223 were female. Mean patient age was 54.9±19.3 years. Pyelonephritis and cystitis were the most common clinical diagnoses, representing 30.7% and 29.9% of patients, respectively. Escherichia coli was the most frequently identified uropathogen (38.7%). For the patients with urinary tract infection, cephalosporins were the most frequently used antibiotics (34.4%), followed by fluoroquinolones (24.1%), aminoglycosides (16.8%). Fluoroquinolone resistance was relatively high (ciprofloxacin 54.9%, levofloxacin 39.0%), and cephalosporin resistance 42% (42.5-49.4%). Of the antibiotics evaluated, uropathogens had maintained the highest level of susceptibility to amikacin and imipenem (24.9% and 11.3% resistance rates, respectively). Uropathogens in many Asian countries had high resistance to broad-spectrum antibiotics. Knowledge of regional and local resistance data and prudent use of antibiotics are important for proper management of UTI in Asian countries.

New aerosol formulation to control ciprofloxacin pulmonary concentration

Ciprofloxacin (CIP) apparent permeability across a pulmonary epithelium model can be controlled by the affinity of its complex with a metal cation. The higher the complex affinity, the larger is the reduction in CIP apparent permeability. The aim of this study was to evaluate if the control of the CIP apparent permeability observed in vitro could be transposed in vivo to control the CIP lung-to-blood absorption rate and CIP concentrations in the lung epithelial lining fluid (ELF) after intratracheal (IT) administration. Two types of innovative inhalable microparticles loaded with the low-affinity CIP-calcium complex (CIP-Ca) or with the high-affinity CIP-copper complex (CIP-Cu) were formulated and characterized. Then, ELF and plasma pharmacokinetics of CIP were studied in rats after IT administration of these two types of microparticles and of a CIP solution (2.5mg/kg). The presence of Cu2+ had little effect on the microparticle properties and the dry powder had aerodynamic properties which allowed it to reach the lungs. CIP concentrations in ELF were much higher after CIP-Cu microparticles IT administration compared to the other two formulations, with mean AUCELF to AUCu,plasma ratios equal to 1069, 203 and 9.8 after CIP-Cu microparticles, CIP-Ca microparticles and CIP solution pulmonary administration, respectively. No significant modification of lung toxicity markers was found (lactate dehydrogenase and total protein). CIP complexation with Cu2+ seems to be an interesting approach to obtain high CIP concentrations in the ELF of lungs after dry powder IT administration.

Phylogeny and antimicrobial resistance in Neisseria gonorrhoeae isolates from Rio de Janeiro, Brazil

Resistance in Neisseria gonorrhoeae is a global public health challenge. However, little is known about N. gonorrhoeae isolates from Brazil. In this study, we characterized 116N. gonorrhoeae isolates obtained in Rio de Janeiro between 2006 and 2015 according to antimicrobial susceptibility profiles, resistance mechanisms, and clonal diversity. We determined antimicrobial minimal inhibitory concentrations by agar dilution, and whole genome sequencing was conducted to investigate alleles related to resistance, determine multilocus sequence typing profiles, and group isolates based on core genome single nucleotide polymorphisms. Resistance to penicillin, tetracycline, ciprofloxacin, and azithromycin was observed since 2006. Resistance to penicillin was mediated by β-lactamase plasmids and chromosomal mutations in ponA and porB genes, and tetracycline resistance was mediated by TetM plasmids, and porB and rspJ mutations. Ciprofloxacin resistant isolates presented cumulative point mutations in the quinolone resistance-determining region (QRDR) of gyrA and parC. Alterations in rrl genes encoding 23S rRNA, mtrR, and the mtrR promoter region were responsible for resistance to azithromycin. Phylogenetic analysis identified seven main clades, which included isolates with similar resistance profiles that mainly belonged to a limited number of sequence types that occurred during different years. Our results demonstrated high penicillin, tetracycline, and ciprofloxacin resistance rates associated with the persistence of successful resistant gonococcal lineages, and the polyclonal emergence of azithromycin resistance. Moreover, we reinforce the importance of surveillance to monitor the evolution of this scenario and to allow the early detection of possible changes to azithromycin and ceftriaxone as effective treatment options in the city.

Preparation of Adsorption Ceramsite Derived from Sludge Biochar

Adsorption ceramsite (SKC) was prepared with biochar (BC) derived from municipal sludge and kaolin (KL) based on the optimized processing parameters to adsorb ciprofloxacin (CIP) in aqueous solutions. The CIP adsorption mechanism of SKC was investigated by adsorption kinetics and isotherm adsorption models, combined with the analysis of microstructure, pore structure, phase composition, and zeta potential. Furthermore, the heavy metal leaching toxicity was assessed using the toxicity characteristic leaching procedure (TCLP) method. The results showed that SKC, with 60% BC and 40% KL calcining at 1,050℃ for 5 min, showed an outstanding removal efficiency of CIP (65.34%). The pseudo-second-order equation agreed with the adsorption behavior and the Freundlich model described the adsorption process well. The adsorption process was a multilayer adsorption controlled by physical and chemical reactions. The leaching concentration of heavy metals, trapped by the mineral phases in SKC was much lower than that in BC, indicating low ecotoxicological risk. SKC possessed the ability to adsorb CIP with its developed porosity and characteristic mineralogical phases, including silicon aluminum oxide and iron oxide. This work provides a low-cost recyclable sorbing material to remove high concentration CIP from wastewater and offers a new idea for the large-scale safe use of BC.

Prevalence and Mechanism of Fluoroquinolone Resistance in Escherichia coli Isolated from Swine Feces in Korea

In this study, we investigated the prevalence and fluoroquinolone (FQ) resistance mechanisms in Escherichia coli isolated from swine fecal samples. E. coli isolates were collected from 171 (72.2%) of 237 swine fecal samples. Of these, 59 isolates (34.5%) were confirmed as FQ-resistant E. coli by the disk diffusion method. Of the FQ-resistant isolates, three major FQ resistance mechanisms were investigated. Of the 59 isolates, plasmid-mediated quinolone resistance genes were detected in 9 isolates (15.3%). Efflux pump activity was found in 56 isolates (94.9%); however, this was not correlated with the increased FQ resistance measured by determining the MIC. Point mutations in quinolone resistance-determining regions were the main cause of FQ resistance. All 59 ciprofloxacin-resistant isolates had mutations in quinolone resistance-determining regions; of these 59 isolates, all (100%) had mutations in gyrA, 58 (98.3%) had mutations in parC, 22 (37.3%) had mutations in parE, and none had mutations in gyrB. The predominant mutation type was double mutation in gyrA (Ser83Leu plus mutation in aspartic acid 87), and all FQ-resistant isolates (except one) that had mutations in parC or parE also had double mutations in gyrA. Importantly, the frequencies of multidrug-resistant and extended-spectrum β-lactamase-producing E. coli were significantly higher in the high ciprofloxacin MIC group in this study. Compared with previous studies in Korea, the prevalence of FQ resistance and plasmid-mediated quinolone resistance genes had increased considerably in swine. Although the use of FQ as a feed additive is prohibited in Korea, use for self-treatment and therapeutic purposes has been increasing, which may be responsible for the higher FQ resistance rate observed in this study. Therefore, prudent use of FQ on animal farms is warranted to reduce the evolution of FQ-resistant bacteria in the animal industry.

Long-term survival and resistance of submerged pseudomonad cultures in the exopolymer mass

An issue on the cellular forms that ensure survival of pseudomonads is important due to wide occurrence of these bacteria in the environment and their role for clinical microbiology. The present work demonstrates the high survival potential of Pseudomonas aurantiaca and P. аeruginosa in the mass of exopolymers produced by cells. Exopolymer formation occurred only during incubation of the post-stationary phase cultures of P. aurantiaca (at 4°C) and P. aeruginosa (at 4 and 20°C). After storage for 1.5–12 months, the number of colony-forming units in the exopolymer was 30 to 68% of the viable cell titer in stationary-phase cultures. Antibiotic-tolerant persister cells that were revealed in the exopolymer cultures after treatment with ciprofloxacin (2.5–100 μg/mL) were more resistant to the antibiotic than persisters in suspension cultures, with the threshold doses of 25 and 2.5 μg/mL, respectively. The cells embedded in the exopolymer were found to be more resistant to 5-min heating at 60–70°C than the vegetative cells of suspension cultures, which did not survive such heat treatment conditions. Electron microscopic investigation revealed morphological heterogeneity of exopolymer-embedded pseudomonads, including the presence of the cells similar to cystlike dormant forms. The populations developing on solid media inoculated with the exopolymer mass with cells were found to contain 1.5 to 2 orders of magnitude more persisters tolerant to high ciprofloxacin doses (25 μg/mL for P. aurantiaca and 100 μg/mL for P. aeruginosa) than the populations developing after inoculation with second-transfer vegetative cells of the cells of planktonic cultures. The results obtained improve our understanding of pseudomonad survival in the environment.

Pharmacokinetics of ciprofloxacin in bath medicated hybrid tilapias using enzyme linked immunosorbent assay (ELISA)

The apparent absence of established dosage regime for medicating tilapia with fluoroquinolones in the country necessitated investigating the absorption and tissue distribution of ciprofloxacin, since dosage regimes conform to accepted standards of pharmacokinetic studies. Ciprofloxacin pharmacokinetic studies were conducted on 76 hybrid tilapia weighing between 100 and 200 grams divided into two groups with each subjected to bath administration of ciprofloxacin at two different concentrations. The fishes in groups 1 and 2 were exposed by bath to 50 mg and 25 mg respectively of ciprofloxacin per litre of water. Tissue and blood samples were collected at 0.5h, 1h, 2h, 4h, and 8h during medication and drug withdrawal at 24h, 48h, and 72h, to quantify their ciprofloxacins by Enzyme Linked Immunosorbent Assay (ELISA). Peak serum concentration of ciprofloxacin in group 1 was 2,251±877 μg/L at 8 h while for group 2; it was 2,226±174 μg/L at 4 h exposure time. The t- test comparing the means of the groups 1 and 2 showed that there was no significant statistical difference (p > 0.05) on group sera, liver and kidney, except skeletal muscle ciprofloxacin concentration. The elimination half-lives in groups 1 and 2 were determined on serum ciprofloxacin values, after withdrawal of drug and were 27.75 h and 31.8 h, with rate constant of elimination being 0.025 h-1 and 0.022 h-1 respectively. Sera Area under Curve, {AUC (0.5-8h)} values were 12,159.3 and 13,194 μg/L respectively with 92.2% correlation. Prolonged high ciprofloxacin concentration was observed in tilapia skeletal muscle. High correlation in sera AUC values is suggestive of similar therapeutic action hence; it is cheaper to use the lower dose. While a prolonged high ciprofloxacin concentration in skeletal muscle has therapeutic advantage for fish, it remains a public health concern because the muscle is an edible tissue.Keywords: Bath, Ciprofloxacin, ELISA, Pharmacokinetics, Tilapia

Contribution of target alteration, protection and efflux pump in achieving high ciprofloxacin resistance in Enterobacteriaceae.

The study aims at revealing the comprehensive contribution of target alteration, target protection and efflux pump to the development of high level of ciprofloxacin (CIP) resistance in Enterobacteriaceae bacteria of environmental, clinical and poultry origins. Antibiotic susceptibility test was used to detect CIP resistant (CIPR) isolates and MICCIP was determined by broth microdilution method. The presence of qnrS gene was identified by PCR and Southern blot hybridization (SBH) confirmed their location. Checkerboard titration demonstrated the effect of NMP on CIP action. PCR followed by sequencing and in silico analysis revealed the contribution of mutations in acrR, marR and gyrA to CIPR development. Out of 152 isolates, 101 were detected as CIPR. Randomly selected 53 isolates (MICCIP 4–512 µg/mL) were identified as Escherichia spp. (26), Enterobacter spp. (7), Klebsiella spp. (5) and Salmonella spp. (15) and of them 31 isolates carried qnrS. qnrS harboring 18 highly CIPR isolates (MICCIP: 256–512 µg/mL) were selected for further study. SBH confirmed 7 isolates harbored qnrS gene in plasmids. The acrA, acrB and tolC were present in all 18 isolates and NMP had an additive (12-isolates) or synergistic (6-isolates) effect on CIP action. Most isolates contained double amino acid (aa) substitutions (S83L and D87N) in QRDR of GyrA resulting in an altered conformation of putative CIP binding pocket. However, some isolates contained single (S83L or S83Y) or no aa substitution but showed high CIPR implicating that the concerted action of three mechanisms is responsible for high CIPR with the most significant role of efflux pump.Electronic supplementary materialThe online version of this article (doi:10.1186/s13568-016-0294-9) contains supplementary material, which is available to authorized users.

Variability of residue concentrations of ciprofloxacin in honey from treated hives

ABSTRACTHoney bees (Apis mellifera L.) were treated with a model veterinary drug compound (ciprofloxacin) in a 3-year study (2012–14) to investigate the variability of residue concentration in honey. Sucrose solution containing ciprofloxacin was administered to 45 hives (1 g of ciprofloxacin per hive) at the beginning of the honey flow in late May/mid-June 2012, 2013 and 2014. Buckfast honey bees (A. mellifera – hybrid) were used in years 2012 and 2013. Carniolan honey bees (A. mellifera carnica) were used instead of the Buckfast honey bees as a replacement due to unforeseen circumstances in the final year of the study (2014). Honey was collected over nine scheduled time points from May/June till late October each year. Up to five hives were removed and their honey analysed per time point. Honey samples were analysed by liquid chromatography-tandem mass spectrometry (LC-MS/MS) to determine ciprofloxacin concentration. Statistical assessment of the data shows that the inter-hive variation of ciprofloxacin concentrations in 2012/13 is very different compared with that of 2014 with relative standard deviations (RSDs) of 138% and 61%, respectively. The average ciprofloxacin concentration for 2014 at the last time point was more than 10 times the concentration compared with samples from 2012/13 at the same time point. The difference between the 2012/13 data compared with the 2014 data is likely due to the different type of honey bees used in this study (2012/13 Buckfast versus 2014 Carniolan). Uncertainty estimates for honey with high ciprofloxacin concentration (upper 95th percentile) across all hives for 55-day withdrawal samples gave residual standard errors (RSEs) of 22%, 20% and 11% for 2012, 2013 and 2014, respectively. If the number of hives were to be reduced for future studies, RSEs were estimated to be 52% (2012), 54% (2013) and 26% (2014) for one hive per time point (nine total hives).

Removal Performance, Antibacterial Effects, and Toxicity Assessment of Ciprofloxacin Treated by the Electrocoagulation Process

This study is concerned with the removal performance of the antibiotic ciprofloxacin (CIP) from synthetic solutions by electrocoagulation (EC), as well as the toxic effects of treated CIP solutions. A response surface analysis (RSA) was applied to search optimal operational parameter values of the pH of solution, electrical current density (ECD), and electrolysis time (ET). The EC efficiency was evaluated by determining the total organic carbon (TOC) and CIP concentration performed by high-performance liquid chromatography. Although the best EC efficiency was attained at pH = 8, ECD = 22.2 A m−2, and ET = 75 min, toxicity and antibacterial tests were performed using Artemia salina cysts and Staphylococcus aureus and Escherichia coli microorganisms in a wide ET range and other pH and ECD values. Increasing optimal pH value (9), along with reducing optimal ECD value (18 A m−2) and regarding low ET values, similar results for the removal of CIP (98%) and TOC (87%) were also attained. Toxicity variation was observed during EC process in synthetic solutions with the lowest antibacterial effects due to CIP and recalcitrant compound residues after 40 min of ET. These results clearly showed that the EC process presents a promising alternative method for the treatment of wastewaters containing high CIP concentrations.

Antibiotic susceptibility of Salmonella, Shigella and Vibrio isolated from diarrhea patients in Jakarta, Indonesia

Background : The rapid increase of antibiotic resistance among enteric pathogens in developing countries has become a great concern. In Indonesia, Salmonella, Shigella, and Vibro are still an important public health problem. Objectives : The purpose of this study was to determine the antibiotic resistance patterns of several diarrhea-causing enteric bacteria that are frequently found in Indonesia, particularly Salmonella, Shigella and Vibrio. Methods : A cross-sectional study was conducted , among 150 rectal swabs collected from patients with diarrhea, the enteric pathogens isolated comprised Shigella (11.4%), Salmonella (6.6%) and Vibrio(2.7%). Results : Antibiotic susceptibility test on Shigella species to several antibiotics such as ampicillin, chloramphenicol, tetracycline and, trimethoprim-sulfamethoxazole showed a considerably high resistance rate (25%-100%), whereas ceftriaxone, ciprofloxacin, norfloxacin and nalidixic acid were apparently still effective (resistance rate 0%). Non-typhoid Salmonella had similar resistance patterns as those of Shigella, particularly to ampicillin, tetracycline, chloramphenicol and trimethoprim- sulfamethoxazole However, for S. typhi it was found that all antibiotics were still effective. Vibrio was resistant to ampicillin (resistance rate 100%), whereas the other antibiotics were still effective. Conclusion: It may be concluded that for each of the enteric pathogens the antibiotic resistance pattern should be determined. Use of antibiotics should be based on the antibiotic susceptibility tests.

Serum and milk concentrations of enrofloxacin in cows intramammarily treated with a new enrofloxacin-polymorph

The success rate in treatment against Staphylococcus aureus mastitis with antibacterial drugs is marginal. Low antibacterial drug concentrations in the mammary tissue is part of the reason for this failure. Enrofloxacin has only been administered on few occasions through the intramammary route i.e., combined with gentamicin in an undisclosed vehicle or dose. A new solvate form of enrofloxacin (enrofloxacin hydrochloride-dihydrate [enro-C]) prepared as 1.5% suspension pH 5.5 was tested in a field mastitis outbreak due to coagulase-negative S. aureus (CNS) in F1 (Holstein/Zebu) cows aged 5-8 years destined to be culled. Enro-C was administered intramammarily daily (300 mg/infected quarter) for 8 days both to healthy and mastitic cows; milk and serum enro-C concentrations were determined on days 1 and 8. Maximum serum concentration (CMAX) values were similar in both groups (9.4 to 10.7 µg/mL). The area under the moment curve (AUMC) for enrofloxacin increased only by 11% in healthy cows and by 10% in infected cows from day 1 to day 8, a fact that suggests little accumulation with this dose regime. Peak concentrations in milk ranged from 18.5 to 19.8 µg/mL on day 1 and from 20.2 to 22 µg/mL on day 8. Cure rates on day 21 after treatment were 75% (12 out of 16 cows) or 69.4% (26 out of 36 glands). Somatic cell counts and California mastitis test showed a positive trend in cured animals. Uniquely high milk enrofloxacin and ciprofloxacin concentrations were obtained after intramammary administration of enro-C. These concentrations seem effective for treating CNS mastitis. The feasibility of incorporating this experimental pharmaceutical preparation of enrofloxacin is discussed.