Population pharmacokinetics of ciprofloxacin in newborns with early onset neonatal sepsis and suspected meningitis

BACKGROUND

Neonatal Sepsis accounts for significant proportion of neonatal mortality globally. Ciprofloxacin can be used as an effective antimicrobial against common causative agents of neonatal sepsis. However, there is only limited information about its pharmacokinetic distribution in plasma and Cerebrospinal fluid (CSF) of neonates.

METHODS

Plasma and CSF samples were taken using a sparse sampling technique from neonates who received at least one dose of intravenous ciprofloxacin. Ciprofloxacin levels were analysed using high-performance liquid chromatography (HPLC). Population pharmacokinetic analysis was conducted using a non-linear mixed-effects modelling using Pumas® (Pharmaceutical Modelling and Simulation) package (Version 2.0).

RESULTS

53 neonates were enroled in the study of whom; 9 (17%) had meningitis. The median concentration of ciprofloxacin in CSF was 1.4 (0.94-2.06) ug/ml and plasma was 2.94 (1.8-5.0) ug/ml. A one-compartment model with first-order elimination fitted the data. Body weight was found to be a significant covariate on volume of distribution (Vd). Simulations based on the final model suggest that dose of 10 mg/kg, intravenous b.d may not be able to achieve the desirable indices.

CONCLUSIONS

One compartment model with weight as a covariate explained the available data. Further studies with modified sampling strategy, larger sample size and variable dose levels are needed.

Ciprofloxacin and pegylated G-CSF combined therapy mitigates brain hemorrhage and mortality induced by ionizing irradiation

Introduction

Brain hemorrhage was found between 13 and 16 days after acute whole-body 9.5 Gy 60Co-γ irradiation (IR). This study tested countermeasures mitigating brain hemorrhage and increasing survival from IR. Previously, we found that pegylated G-CSF therapy (PEG) (i.e., Neulasta®, an FDA-approved drug) improved survival post-IR by 20-40%. This study investigated whether Ciprofloxacin (CIP) could enhance PEG-induced survival and whether IR-induced brain hemorrhage could be mitigated by PEG alone or combined with CIP.

Methods

B6D2F1 female mice were exposed to 60Co-γ-radiation. CIP was fed to mice for 21 days. PEG was injected on days 1, 8, and 15. 30-day survival and weight loss were studied in mice treated with vehicles, CIP, PEG, or PEG + CIP. For the early time point study, blood and sternums on days 2, 4, 9, and 15 and brains on day 15 post-IR were collected. Platelet numbers, brain hemorrhage, and histopathology were analyzed. The cerebellum/pons/medulla oblongata were detected with glial fibrillary acidic protein (GFAP), p53, p16, interleukin-18 (IL-18), ICAM1, Claudin 2, ZO-1, and complement protein 3 (C3).

Results

CIP + PEG enhanced survival after IR by 85% vs. the 30% improvement by PEG alone. IR depleted platelets, which was mitigated by PEG or CIP + PEG. Brain hemorrhage, both surface and intracranial, was observed, whereas the sham mice displayed no hemorrhage. CIP or CIP + PEG significantly mitigated brain hemorrhage. IR reduced GFAP levels that were recovered by CIP or CIP + PEG, but not by PEG alone. IR increased IL-18 levels on day 4 only, which was inhibited by CIP alone, PEG alone, or PEG + CIP. IR increased C3 on day 4 and day 15 and that coincided with the occurrence of brain hemorrhage on day 15. IR increased phosphorylated p53 and p53 levels, which was mitigated by CIP, PEG or PEG + CIP. P16, Claudin 2, and ZO-1 were not altered; ICAM1 was increased.

Discussion

CIP + PEG enhanced survival post-IR more than PEG alone. The Concurrence of brain hemorrhage, C3 increases and p53 activation post-IR suggests their involvement in the IR-induced brain impairment. CIP + PEG effectively mitigated the brain lesions, suggesting effectiveness of CIP + PEG therapy for treating the IR-induced brain hemorrhage by recovering GFAP and platelets and reducing C3 and p53.

Vedolizumab for the Treatment of Chronic Pouchitis

BACKGROUND

Approximately half the patients with ulcerative colitis who undergo restorative proctocolectomy with ileal pouch-anal anastomosis (IPAA) will subsequently have pouchitis, and among those patients, one fifth will have chronic pouchitis.

METHODS

We conducted a phase 4, double-blind, randomized trial to evaluate vedolizumab in adult patients in whom chronic pouchitis had developed after undergoing IPAA for ulcerative colitis. Patients were assigned (in a 1:1 ratio) to receive vedolizumab intravenously at a dose of 300 mg or placebo on day 1 and at weeks 2, 6, 14, 22, and 30. All the patients received concomitant ciprofloxacin from weeks 1 to 4. The primary end point was modified Pouchitis Disease Activity Index (mPDAI)-defined remission (an mPDAI score of ≤4 and a reduction from baseline of ≥2 points in the mPDAI total score; scores range from 0 to 12, with higher scores indicating more severe pouchitis) at week 14. The mPDAI is based on clinical symptoms and endoscopic findings. Other efficacy end points included mPDAI-defined remission at week 34, mPDAI-defined response (a reduction from baseline of ≥2 points in the mPDAI score) at weeks 14 and 34, and PDAI-defined remission (a PDAI score of ≤6 and a reduction from baseline of ≥3 points; scores range from 0 to 18, with higher scores indicating more severe pouchitis) at weeks 14 and 34. The PDAI is based on clinical symptoms, endoscopic findings, and histologic findings.

RESULTS

Among the 102 patients who underwent randomization, the incidence of mPDAI-defined remission at week 14 was 31% (16 of 51 patients) with vedolizumab and 10% (5 of 51 patients) with placebo (difference, 21 percentage points; 95% confidence interval [CI], 5 to 38; P = 0.01). Differences in favor of vedolizumab over placebo were also seen with respect to mPDAI-defined remission at week 34 (difference, 17 percentage points; 95% CI, 0 to 35), mPDAI-defined response at week 14 (difference, 30 percentage points; 95% CI, 8 to 48) and at week 34 (difference, 22 percentage points; 95% CI, 2 to 40), and PDAI-defined remission at week 14 (difference, 25 percentage points; 95% CI, 8 to 41) and at week 34 (difference, 19 percentage points; 95% CI, 2 to 37). Serious adverse events occurred in 3 of 51 patients (6%) in the vedolizumab group and in 4 of 51 patients (8%) in the placebo group.

CONCLUSIONS

Treatment with vedolizumab was more effective than placebo in inducing remission in patients who had chronic pouchitis after undergoing IPAA for ulcerative colitis. (Funded by Takeda; EARNEST ClinicalTrials.gov number, NCT02790138; EudraCT number, 2015-003472-78.).

Dynamics of the QTc interval over a 24-h dose interval after start of intravenous ciprofloxacin or low-dose erythromycin administration in ICU patients

QTc interval prolongation is an adverse effect associated with the use of fluoroquinolones and macrolides. Ciprofloxacin and erythromycin are both frequently prescribed QTc-prolonging drugs in critically ill patients. Critically ill patients may be more vulnerable to developing QTc prolongation, as several risk factors can be present at the same time. Therefore, it is important to know the QTc-prolonging potential of these drugs in the intensive care unit (ICU) population. The aim of this study was to assess the dynamics of the QTc interval over a 24-hour dose interval during intravenous ciprofloxacin and low-dose erythromycin treatment. Therefore, an observational study was performed in ICU patients (≥18 years) receiving ciprofloxacin 400 mg t.i.d. or erythromycin 100 mg b.i.d. intravenously. Continuous ECG data were collected from 2 h before to 24 h after the first administration. QT-analyses were performed using high-end holter software. The effect was determined with a two-sample t-test for clustered data on all QTc values. A linear mixed model by maximum likelihood was applied, for which QTc values were assessed for the available time intervals and therapy. No evident effect over time on therapy with ciprofloxacin and erythromycin was observed on QTc time. There was no significant difference (p = 0.22) in QTc values between the ciprofloxacin group (mean 393 ms) and ciprofloxacin control group (mean 386 ms). The erythromycin group (mean 405 ms) and erythromycin control group (mean 404 ms) neither showed a significant difference (p = 0.80). In 0.6% of the registrations (1.138 out of 198.270 samples) the duration of the QTc interval was longer than 500 ms. The index groups showed slightly more recorded QTc intervals over 500 ms. To conclude, this study could not identify differences in the QTc interval between the treatments analyzed.

Transrectal povidone-iodine efficiency in reducing infections occurring after transrectal ultrasound guided biopsy of the prostate

ABSTRACT

The present study aimed to compare infectious complications in men undergoing transrectal ultrasound-guided prostate biopsy (TRUS-Bx) with and without povidone-iodine transrectal injection using a gavage syringe.The records of 112 patients, who underwent TRUS-Bx between January 2016 and December 2019, were retrospectively reviewed. The biopsy indication was considered high prostate-specific antigen (PSA) level and/or suspicious digital rectal prostate examination findings. Patients' ages, underlying diseases, PSA levels, prostate volumes, pathologic results, and infectious complications after the biopsy were investigated. All the patients received 1500 mg of ciprofloxacin (750 mg twice a day) for 5 days, starting from the day before the procedure. Forty-seven (41.96%) patients received ciprofloxacin prophylaxis with povidone-iodine transrectal injection, while 65 (58.03%) only received ciprofloxacin prophylaxis. All the patients, who were readmitted to the hospital after the procedure, especially with a temperature of higher than 37.8°C, were detected. For the purposes of the study, the priority was placed on the emergence of the rate of febrile infectious complications. Differences in febrile infectious complications in patients, who received ciprofloxacin prophylaxis with transrectal povidone-iodine, and those, who received ciprofloxacin prophylaxis alone before TRUS-Bx, were studied.Febrile infectious complications developed in 10 cases (15.38%) in patients, who received ciprofloxacin antibiotics prophylaxis alone. In the povidone-iodine rectal disinfection group, there was only 1 case of febrile infectious complication (2%). There was no significant difference by clinicopathologic features, age, PSA level, and cancer detection rate between both groups (P > .05). Multivariate logistic regression analysis did not identify any patient subgroups at a significantly higher risk of infection after prostate biopsy. There was no significant side effect associated with povidone iodine.In addition to the use of prophylactic antibiotics, transrectal povidone-iodine was useful in reducing the febrile infection complications following TRUS-Bx.

Validity of caregivers' reports on prior use of antibacterials in children under five years presenting to health facilities in Gulu, northern Uganda

INTRODUCTION

Given the frequent initiation of antibacterial treatment at home by caregivers of children under five years in low-income countries, there is a need to find out whether caregivers' reports of prior antibacterial intake by their children before being brought to the healthcare facility are accurate. The aim of this study was to describe and validate caregivers' reported use of antibacterials by their children prior to seeking care at the healthcare facility.

METHODS

A cross sectional study was conducted among children under five years seeking care at healthcare facilities in Gulu district, northern Uganda. Using a researcher administered questionnaire, data were obtained from caregivers regarding reported prior antibacterial intake in their children. These reports were validated by comparing them to common antibacterial agents detected in blood and urine samples from the children using liquid chromatography with tandem mass spectrometry (LC-MS/MS) methods.

RESULTS

A total of 355 study participants had a complete set of data on prior antibacterial use collected using both self-report and LC-MS/MS. Of the caregivers, 14.4% (51/355, CI: 10.9-18.5%) reported giving children antibacterials prior to visiting the healthcare facility. However, LC-MS/MS detected antibacterials in blood and urine samples in 63.7% (226/355, CI: 58.4-68.7%) of the children. The most common antibacterials detected from the laboratory analysis were cotrimoxazole (29%, 103/355), ciprofloxacin (13%, 46/355), and metronidazole (9.9%, 35/355). The sensitivity, specificity, positive predictive value (PPV), negative predictive value and agreement of self-reported antibacterial intake prior to healthcare facility visit were 17.3% (12.6-22.8), 90.7% (84.3-95.1), 76.5% (62.5-87.2), 38.5% (33.0-44.2) and 43.9% (k 0.06) respectively.

CONCLUSION

There is low validity of caregivers' reports on prior intake of antibacterials by these children. There is need for further research to understand the factors associated with under reporting of prior antibacterial use.

Effect of 7 vs 14 Days of Antibiotic Therapy on Resolution of Symptoms Among Afebrile Men With Urinary Tract Infection: A Randomized Clinical Trial

IMPORTANCE

Determination of optimal treatment durations for common infectious diseases is an important strategy to preserve antibiotic effectiveness.

OBJECTIVE

To determine whether 7 days of treatment is noninferior to 14 days when using ciprofloxacin or trimethoprim/sulfamethoxazole to treat urinary tract infection (UTI) in afebrile men.

DESIGN, SETTING, AND PARTICIPANTS

Randomized, double-blind, placebo-controlled noninferiority trial of afebrile men with presumed symptomatic UTI treated with ciprofloxacin or trimethoprim/sulfamethoxazole at 2 US Veterans Affairs medical centers (enrollment, April 2014 through December 2019; final follow-up, January 28, 2020). Of 1058 eligible men, 272 were randomized.

INTERVENTIONS

Participants continued the antibiotic prescribed by their treating clinician for 7 days of treatment and were randomized to receive continued antibiotic therapy (n = 136) or placebo (n = 136) for days 8 to 14 of treatment.

MAIN OUTCOMES AND MEASURES

The prespecified primary outcome was resolution of UTI symptoms by 14 days after completion of active antibiotic treatment. A noninferiority margin of 10% was selected. The as-treated population (participants who took ≥26 of 28 doses and missed no more than 2 consecutive doses) was used for the primary analysis, and a secondary analysis included all patients as randomized, regardless of treatment adherence. Secondary outcomes included recurrence of UTI symptoms and/or adverse events within 28 days of stopping study medication.

RESULTS

Among 272 patients (median [interquartile range] age, 69 [62-73] years) who were randomized, 100% completed the trial and 254 (93.4%) were included in the primary as-treated analysis. Symptom resolution occurred in 122/131 (93.1%) participants in the 7-day group vs 111/123 (90.2%) in the 14-day group (difference, 2.9% [1-sided 97.5% CI, -5.2% to ∞]), meeting the noninferiority criterion. In the secondary as-randomized analysis, symptom resolution occurred in 125/136 (91.9%) participants in the 7-day group vs 123/136 (90.4%) in the 14-day group (difference, 1.5% [1-sided 97.5% CI, -5.8% to ∞]) Recurrence of UTI symptoms occurred in 13/131 (9.9%) participants in the 7-day group vs 15/123 (12.9%) in the 14-day group (difference, -3.0% [95% CI, -10.8% to 6.2%]; P = .70). Adverse events occurred in 28/136 (20.6%) participants in the 7-day group vs 33/136 (24.3%) in the 14-day group.

CONCLUSIONS AND RELEVANCE

Among afebrile men with suspected UTI, treatment with ciprofloxacin or trimethoprim/sulfamethoxazole for 7 days was noninferior to 14 days of treatment with regard to resolution of UTI symptoms by 14 days after antibiotic therapy. The findings support the use of a 7-day course of ciprofloxacin or trimethoprim/sulfamethoxazole as an alternative to a 14-day course for treatment of afebrile men with UTI.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT01994538.

[Achilles tendinopathy in a hemodialysis patient complicated by rupture of the Achilles tendon due to self-medication with ciprofloxacin: about a case]

This study aims to remind clinicians of fluoroquinolone-related tendinopathies. They are rare side effects, but which can result in functional disability. We report the case of a 79-year-old woman with a 11-year history of haemodialysis who had sudden left ankle pain and functional impairment in the ipsilateral member on day 5th after self-medication with ciprofloxacin. Comorbidities included chronic gonarthrosis, secondary hyperparathyroidism and ischemic heart disease. The diagnosis of bilateral Achilles tendinopathy and rupture of the left Achilles tendon was retained due to clinical features and confirmed by ultrasound of ankles. Ciprofloxacin-associated tendon rupture was evaluated using the French method of accountability for drug unexpected side effects or toxicity. Tendon rupture management was based on surgery followed by functional rehabilitation program with satisfactory outcome. The frequency of fluoroquinolone-related tendinopathies ranges from 15 to 20 accidents per 100,000 subjects treated, a third of whom are complicated by tendon rupture. Incidence is related to age, affecting mainly people > 60 years and involving tissular aging. Pefloxacin and ciprofloxacin are the most offending molecules. In our study, the delay in the onset of symptoms on day 5 after self-medication was consistent with literature. We detected some common contributing factors including chronic renal failure, hemodialysis and the assumption of statins and corticosteroids. Fluoroquinolone-related tendinopathies are characterized by common clinical features which allow diagnosis. They mostly affect Achilles tendon. They are bilateral in 40-66% of cases. Tendon rupture is the main complication. Management is based on surgery. It allows to restore anatomy and to prevent detrimental functional disability. We here report a rare but potentially serious fluoroquinolones-related side effect, exposing the patient to the risk of functional disability. Advanced age, chronic renal failure, chronic haemodialysis, concomitant use of statins and corticosteroids are common contributing factors confirmed in this study. Hemodialysis patients constitute a population at risk; hence the importance of remote monitoring after treatment with these molecules.

Hospital-based ciprofloxacin use evaluation in Eastern Ethiopia: a retrospective assessment of clinical practice

INTRODUCTION

ciprofloxacin is a second-generation fluoroquinolone, which has been used as one of the top three antibacterial agents prescribed in Ethiopia. However, its use has deviated from the recommendation of standard treatment guidelines resulting in a gradual increase in antimicrobial resistance. Therefore, this study aimed to evaluate the annual use of ciprofloxacin in 2016 based on the standard Ethiopian treatment and World Health Organization guidelines, in governmental hospitals, in Eastern Ethiopia from 1st May to 30th June 2018.

METHODS

a hospital-based retrospective cross-sectional study was conducted to evaluate medical records of patients who had taken ciprofloxacin in 2016. The total sample size (n=522) was proportionally allocated to each hospital based on the respective consumption data. A simple random sampling method was employed to collect the required sample. The collected data were entered into SPSS version 21 and analyzed using descriptive analysis.

RESULTS

in this study, 522 medical records were reviewed, with a male to female ratio of 1.03: 1. Ciprofloxacin was indicated in 478 (91.6%) participants whose age was greater than eighteen years. The majority were treated in the medical and emergency outpatient departments (n=477, 91.4%). Urinary tract infections (n=224, 42.9%), acute febrile illnesses (n=68, 13.0%), and typhoid fever (n=54, 10.4%) were the top indications to which ciprofloxacin was prescribed. Non-steroidal anti-inflammatory drugs (NSAIDs) (n=241, 34.7%) and antimicrobials (n=135, 19.6%) were among the most frequently co-indicated agents. Based on the standard Ethiopian treatment guidelines, therapy was appropriate in 30% (n= 159) of patients. The major reason for inappropriate utilization (95%) was the wrong duration of antibiotic use (n=228). Evaluation based on World Health Organization criteria showed that indication, dose, and frequency were in line with the recommendation.

CONCLUSION

ciprofloxacin was primarily indicated for urinary tract infections. The drug was appropriately used in less than one-third of patients, with the wrong duration being the main reason for overall inappropriate utilization. This trend may potentially impose a high risk to the emergence of drug-resistant microorganisms. To this end, further studies addressing the susceptibility pattern of bacterial isolates towards ciprofloxacin should be carried out.

Synthesis and characterization of novel tamarind gum and rice bran oil-based emulgels for the ocular delivery of antibiotics

In this study, we developed tamarind gum (TG) and rice bran oil (RBO)-based emulgels. The control formulation (TR0), did not contain RBO. The emulgels were named as TR1, TR2, TR3, and TR4, which contained 5% (w/w), 10% (w/w), 15% (w/w), and 20% (w/w/) of RBO, respectively. The microscopic studies showed that the emulgels were biphasic in nature. FTIR spectroscopy revealed the reduction in the hydrogen bonding with an increase in the RBO content. Impedance profiles suggested that the resistive component of the emulgels was increased as the RBO content was increased. The thermal analysis suggested that the addition of RBO reduced the water holding capacity of the emulgels. Stress relaxation studies revealed that the fluidic component was considerably higher in TG/RBO-based emulgels as compared to TR0. In vitro release study of the model drug (ciprofloxacin HCl; a hydrochloride salt of ciprofloxacin) suggested a significantly lower release from the emulgel matrices (TR1-TR4) in comparison to TR0. However, ex vivo corneal permeation of the drug increased with an increase in the RBO content. Since the emulgels were able to improve the corneal permeation of the model drug, the emulgels can be explored to deliver drugs to the internal structures of the eye.

Synergistic activity of phage PEV20-ciprofloxacin combination powder formulation-A proof-of-principle study in a P. aeruginosa lung infection model

Combination treatment using bacteriophage and antibiotics is potentially an advanced approach to combatting antimicrobial-resistant bacterial infections. We have recently developed an inhalable powder by co-spray drying Pseudomonas phage PEV20 with ciprofloxacin. The purpose of this study was to assess the in vivo effect of the powder using a neutropenic mouse model of acute lung infection. The synergistic activity of PEV20 and ciprofloxacin was investigated by infecting mice with P. aeruginosa, then administering freshly spray-dried single PEV20 (10⁶ PFU/mg), single ciprofloxacin (0.33 mg/mg) or combined PEV20-ciprofloxacin treatment using a dry powder insufflator. Lung tissues were then harvested for colony counting and flow cytometry analysis at 24 h post-treatment. PEV20 and ciprofloxacin combination powder significantly reduced the bacterial load of clinical P. aeruginosa strain in mouse lungs by 5.9 log₁₀ (p < 0.005). No obvious reduction in the bacterial load was observed when the animals were treated only with PEV20 or ciprofloxacin. Assessment of immunological responses in the lungs showed reduced inflammation associating with the bactericidal effect of the PEV20-ciprofloxacin powder. In conclusion, this study has demonstrated the synergistic potential of using the combination PEV20-ciprofloxacin powder for P. aeruginosa respiratory infections.

Controlled release of ciprofloxacin and ceftriaxone from a single ototopical administration of antibiotic-loaded polymer microspheres and thermoresponsive gel

Acute otitis media (AOM) is the main indication for pediatric antibiotic prescriptions, accounting for 25% of prescriptions. While the use of topical drops can minimize the administered dose of antibiotic and adverse systemic effects compared to oral antibiotics, their use has limitations, partially due to low patient compliance, high dosing frequency, and difficulty of administration. Lack of proper treatment can lead to development of chronic OM, which may require invasive interventions. Previous studies have shown that gel-based drug delivery to the ear is possible with intratympanic injection or chemical permeation enhancers (CPEs). However, many patients are reluctant to accept invasive treatments and CPEs have demonstrated toxicity to the tympanic membrane (TM). We developed a novel method of delivering therapeutics to the TM and middle ear using a topical, thermoresponsive gel depot containing antibiotic-loaded poly(lactic-co-glycolic acid) microspheres. Our in vitro and ex vivo results suggest that the sustained presentation can safely allow therapeutically relevant drug concentrations to penetrate the TM to the middle ear for up to 14 days. Animal results indicate sufficient antibiotic released for treatment from topical administration 24h after bacterial inoculation. However, animals treated 72h after inoculation, a more clinically relevant treatment practice, displayed spontaneous clearance of infection as is also often observed in the clinic. Despite this variability in the disease model, data suggest the system can safely treat bacterial infection, with future studies necessary to optimize microsphere formulations for scaled up dosage of antibiotic as well as further investigation of the influence of spontaneous bacterial clearance and of biofilm formation on effectiveness of treatment. To our knowledge, this study represents the first truly topical drug delivery system to the middle ear without the use of CPEs.

Optimization of inhalable liposomal powder formulations and evaluation of their in vitro drug delivery behavior in Calu-3 human lung epithelial cells

Inhalation therapy has advantages for the treatment of multidrug resistant bacterial lung infections with high drug concentrations at the infection sites in the airways and reduced systemic exposure. We have developed liposomal formulations for pulmonary delivery of synergistic ciprofloxacin (Cipro) and colistin (Col) as the potential candidate for treatment of lung infections caused by multidrug resistant Gram-negative bacteria. This study aims to: (1) further optimize the powder formulation by adding drying stabilizers (polyvinyl pyrrolidone or poloxamer) to protect the liposomes during spray-freeze-drying; (2) evaluate the transport and cellular uptake of drugs in a human lung epithelial Calu-3 cell model. The liposomal powder formulations were produced using the ultrasonic spray-freeze-drying technique. The optimal formulation (F5) used mannitol (8% w/v) and sucrose (2% w/v) as the internal lyoprotectants. Adding external lyoprotectants/aerosolization enhancers (i.e. 8% w/v mannitol, 2% w/v sucrose and 1%, w/w PVP 10) produced the superior rehydrated EE values of ciprofloxacin and colistin (50.2 ± 0.9% for Cipro and 37.8 ± 1.2% for Col) as well as satisfactory aerosol performance (FPF: 34.2 ± 0.8% for Cipro and 33.6 ± 0.9% for Col). The cytotoxicity study indicated that F5 with the colistin concentration at 50 μg/mL and ciprofloxacin at 200 μg/mL was not cytotoxic to human lung epithelial Calu-3 cells. The intracellular uptake of ciprofloxacin was concentration-dependent in Calu-3 cells and the uptake of A-B was more than that of B-A for all samples (p < 0.05). This study demonstrates that co-delivery of ciprofloxacin and colistin in a single liposome can lower the transport capability of both drugs across the Calu-3 cell monolayer and their accumulation in the cells. These findings indicate that co-loaded liposomal powder of ciprofloxacin and colistin is a promising potential treatment for respiratory infections caused by multidrug resistant Gram-negative bacteria.

Early neonatal sepsis and meningitis caused by Elizabethkingia meningoseptica in Saudi Arabia

Elizabethkingia meningoseptica (E. meningoseptica ) are Gram-negative bacteria commonly associated with nosocomial infections in neonates. This is a case study of E. meningoseptica, presented as meningitis and sepsis in a term baby. The female infant was born by vaginal delivery at 37 weeks gestational age. The case was peculiar because the baby was neither premature nor immuno-compromised, which are known risk factors for E. meningoseptica infection. The onset began on the second day of the neonate’s life. On day 3, peripheral blood culture and cerebrospinal fluid findings isolated a gram-negative bacteria identified as E. meningoseptica. The first-line antibiotics therapy was changed to ciprofloxacin, vancomycin, and rifampicin, based on the laboratory determination of antimicrobial sensitivity. The patient’s clinical condition improved, although post hemorrhagic ventricular dilatation was revealed by imaging studies. Clinicians should possess proper awareness of the antibiotic sensitivity of E. meningoseptica, as it is important in preventing high rates of morbidity and mortality.

Potentiation of Antibiotics by a Novel Antimicrobial Peptide against Shiga Toxin Producing E. coli O157:H7

Infection with Shiga toxin-producing Escherichia coli (STEC) results in hemorrhagic colitis and can lead to life-threatening sequelae including hemolytic uremic syndrome (HUS). Conventional treatment is intravenous fluid volume expansion. Antibiotic treatment is contraindicated, due in part to the elevated risk of HUS related to increased Shiga toxin (Stx) release associated with some antibiotics. Given the lack of effective strategies and the increasing number of STEC outbreaks, new treatment approaches are critically needed. In this study, we used an antimicrobial peptide wrwycr, previously shown to enhance STEC killing without increasing Stx production, in combination with antibiotic treatments. Checkerboard and time-kill assays were used to assess peptide wrwycr-antibiotic combinations for synergistic STEC killing. Cytotoxicity and real-time PCR were used to evaluate Stx production and stx expression, respectively, associated with these combinations. The synergistic combinations that showed rapid killing, no growth recovery and minimal Stx production were peptide wrwycr-kanamycin/gentamicin. Transmission electron microscopy revealed striking differences in bacterial cell morphology associated with various treatments. This study provides proof of principle for the design of an antibiotic-peptide wrwycr combination effective in killing STEC without enhancing release of Shiga toxins. It also offers a strategy for the repurposing of antibiotics for treatment of STEC infection.

Development and selection of low-level multi-drug resistance over an extended range of sub-inhibitory ciprofloxacin concentrations in Escherichia coli

To better combat bacterial antibiotic resistance, a growing global health threat, it is imperative to understand its drivers and underlying biological mechanisms. One potential driver of antibiotic resistance is exposure to sub-inhibitory concentrations of antibiotics. This occurs in both the environment and clinic, from agricultural contamination to incorrect dosing and usage of poor-quality medicines. To better understand this driver, we tested the effect of a broad range of ciprofloxacin concentrations on antibiotic resistance development in Escherichia coli. We observed the emergence of stable, low-level multi-drug resistance that was both time and concentration dependent. Furthermore, we identified a spectrum of single mutations in strains with resistant phenotypes, both previously described and novel. Low-level class-wide resistance, which often goes undetected in the clinic, may allow for bacterial survival and establishment of a reservoir for outbreaks of high-level antibiotic resistant infections.

Cuminaldehyde potentiates the antimicrobial actions of ciprofloxacin against Staphylococcus aureus and Escherichia coli

Escherichia coli and Staphylococcus aureus are important agents of urinary tract infections that can often evolve to severe infections. The rise of antibiotic-resistant strains has driven the search for novel therapies to replace the use or act as adjuvants of antibiotics. In this context, plant-derived compounds have been widely investigated. Cuminaldehyde is suggested as the major antimicrobial compound of the cumin seed essential oil. However, this effect is not fully understood. Herein, we investigated the in silico and in vitro activities of cuminaldehyde, as well as its ability to potentiate ciprofloxacin effects against S. aureus and E. coli. In silico analyses were performed by using different computational tools. The PASS online and SwissADME programmes were used for the prediction of biological activities and oral bioavailability of cuminaldehyde. For analysis of the possible toxic effects and the theoretical pharmacokinetic parameters of the compound, the Osiris, SwissADME and PROTOX programmes were used. Estimations of cuminaldehyde gastrointestinal absorption, blood brain barrier permeability and skin permeation by using SwissADME; and drug likeness and score by using Osiris, were also evaluated The in vitro antimicrobial effects of cuminaldehyde were determined by using microdilution, biofilm formation and time-kill assays. In silico analysis indicated that cuminaldehyde may act as an antimicrobial and as a membrane permeability enhancer. It was suggested to be highly absorbable by the gastrointestinal tract and likely to cross the blood brain barrier. Also, irritative and harmful effects were predicted for cuminaldehyde if swallowed at its LD50. Good oral bioavailability and drug score were also found for this compound. Cuminaldehyde presented antimicrobial and anti-biofilm effects against S. aureus and E. coli.. When co-incubated with ciprofloxacin, it enhanced the antibiotic antimicrobial and anti-biofilm actions. We suggest that cuminaldehyde may be useful as an adjuvant therapy to ciprofloxacin in S. aureus and E. coli-induced infections.

Inhalable liposomal powder formulations for co-delivery of synergistic ciprofloxacin and colistin against multi-drug resistant gram-negative lung infections

The aim of this study was to design and characterize dry powder inhaler formulations of ciprofloxacin and colistin co-loaded liposomes prepared by the ultrasonic spray-freeze-drying (USFD) technique. Liposomal formulations and powder production parameters were optimized to achieve optimal characteristics and in-vitro performance such as encapsulation efficiency (EE), particle size, particle distribution index (PDI), fine particle fraction (FPF), emitted dose (ED) and in vitro antibacterial activity. The formulation (F6) with the mannitol (5% w/v) as the internal lyoprotectant and sucrose (5%, w/v), mannitol (10%, w/v) and leucine (5%, w/w) as the external lyoprotectants/aerosolization enhancers showed an optimal rehydrated EE values of ciprofloxacin and colistin (44.9 ± 0.9% and 47.0 ± 0.6%, respectively) as well as satisfactory aerosol performance (FPF: 45.8 ± 2.2% and 43.6 ± 1.6%, respectively; ED: 97.0 ± 0.5% and 95.0 ± 0.6%, respectively). For the blank liposomes, there was almost no inhibitory effect on the cell proliferation in human lung epithelial A549 cells, showing that the lipid materials used in the liposome formulation is safe for use in pulmonary drug delivery. The cytotoxicity study demonstrated that the optimized liposomal formulation (F6) was not cytotoxic at least at the drug concentrations of colistin 5 μg/mL and ciprofloxacin 20 μg/mL. Colistin (2 mg/L) monotherapy showed no antibacterial effect against P. aeruginosa H131300444 and H133880624. Ciprofloxacin (8 mg/L) monotherapy showed moderate bacterial killing for both clinical isolates; however, regrowth was observed in 6 h for P. aeruginosa H133880624. The liposomal formulation displayed superior antibacterial activity against clinical isolates of Pseudomonas aeruginosa H131300444 and P. aeruginosa H133880624 compared to each antibiotic per se. These results demonstrate that the liposomal powder formulation prepared by USFD could potentially be a pulmonary delivery system for antibiotic combination to treat multi-drug resistant Gram-negative lung infections.

Assessment of contribution of BCRP to intestinal absorption of various drugs using portal-systemic blood concentration difference model in mice

Prediction of the intestinal absorption of new chemical entities (NCEs) is still difficult, in part because drug efflux transporters, including breast cancer resistance protein (BCRP) and P-glycoprotein (P-gp), restrict their intestinal permeability. We have demonstrated that the absorptive quotient (AQ) obtained from the in vitro Caco-2 permeability study would be a valuable parameter for estimating the impact of BCRP on the intestinal absorption of drugs. In this study, in order to assess the correlation between the in vitro AQ for BCRP and in vivo contribution of BCRP on drug absorption, we evaluated the oral absorption of various compounds by portal-systemic blood concentration (P-S) difference method in wild-type (WT), Bcrp(-/-), and Mdr1a/1b(-/-) mice. In addition, we also calculated a rate of BCRP contribution (Rbcrp ). Ciprofloxacin and nitrofurantoin showed the low Rbcrp value (0.05 and 0.15), and their apparent fractions of intestinal absorption in WT mice were 46.5% and 63.7%, respectively. These results suggest that BCRP hardly affects their intestinal absorption in mice. On the other hand, the apparent fraction of intestinal absorption of topotecan and sulfasalazine was significantly lower in WT mice than in Bcrp(-/-) mice. Moreover, their Rbcrp values were 0.42 and 0.79, respectively, indicating the high contribution of BCRP to their oral absorption. Furthermore, in vivo Rbcrp calculated in this study was almost comparable to in vitro AQ obtained from Caco-2 permeability study. This study provides useful concepts in assessing the contribution of BCRP on intestinal absorption in drug discovery and development process.

Current routines for antibiotic prophylaxis prior to transrectal prostate biopsy: a national survey to all urology clinics in Sweden

Background: The risk of infection after transrectal ultrasound (TRUS)-guided prostate biopsies is increasing. The aim of the study was to assess the use of antibiotic prophylaxis for prostate biopsy in Sweden. Methods: All public and private urology clinics reporting to the National Prostate Cancer Register of Sweden received a survey on TRUS-biopsy prophylaxis. Results: Of the 84 clinics surveyed, 76 replied (90%). If no risk factors for infection were present, a single dose of ciprofloxacin 750 mg was used by 50 clinics (66%). Multiple doses of ciprofloxacin 500 or 750 mg (n=14; 18%) or a single dose of trimethoprim-sulfamethoxazole 160/800 mg (n=7; 9%) were other common prophylaxes. Most clinics gave the prophylaxes immediately before the biopsy (n=41; 54%). Urine dipstick was used by 30 clinics (39%) and rectal enema by six (8%). In patients with high risk of infection, the survey mirrors a large variety of regiments used. Conclusions: The preference to use a single dose of ciprofloxacin 750 mg is in accordance with the Swedish national guidelines for patients with a low risk of infection. Better compliance to the guideline recommendation to use a urine dipstick would probably increase the number of patients classified as having an increased risk of infection. Being classified as a high-risk patient should lead to an extended duration of antibiotic prophylaxis, however, the variety of regimens used in the high-risk group reflects an inability to treat these patients in a standardized fashion and also highlights a need for more clear-cut guidelines. Pre-biopsy identification of high-risk patients is an important issue to tackle for the urologic clinics in order to reduce the number of infections.

Formation of ciprofloxacin nanocrystals within liposomes by spray drying for controlled release via inhalation

The present study was conducted to harness spray drying technology as a novel method of producing Ciprofloxacin nanocrystals inside liposomes (CNL) for inhalation delivery. Liposomal ciprofloxacin dispersions were spray dried with sucrose as a lyoprotectant in different mass ratios (0.5:1, 1:1 and 2:1 sucrose to lipids), along with 2% w/w magnesium stearate and 5% w/w isoleucine as aerosolization enhancers. Spray drying conditions were: inlet air temperature 50 °C, outlet air temperature 33-35 °C, atomizer rate 742 L/h and aspirator 35 m³/h. After spray drying, the formation of ciprofloxacin nanocrystals inside the liposomes was confirmed by cryo- transmission electron microscopy. The physiochemical characteristics of the spray dried powder (particle size, morphology, crystallinity, moisture content, drug encapsulation efficiency (EE), in vitro aerosolization performance and drug release) were determined. The EE of the liposomes was found to vary between 44 and 87% w/w as the sucrose content was increased from 25 to 57% w/w. The powders contained partially crystalline particles with a volume median diameter of ~1 µm. The powders had low water content (~2% wt.) and were stable at high relative humidity. Aerosol delivery using the Osmohaler® inhaler at a flow rate of 100 L/min produced an aerosol fine particle fraction (% wt. <5 µm) of 58-64%. The formulation with the highest sucrose content (2:1 w/w sucrose to lipid) demonstrated extended ciprofloxacin release from liposomes (80% released within 7 h) in comparison to the original liquid formulation (80% released within 2 h). In conclusion, a stable and inhalable CNL powder with controlled drug release was successfully prepared by spray drying.

Ciprofloxacin Functionalized Biogenic Gold Nanoflowers as Nanoantibiotics Against Pathogenic Bacterial Strains

PURPOSE

Antibiotics are currently being rendered non-functional by the rising incidence of multi-drug resistance amongst pathogenic bacteria. Research has now been focused on developing solutions to this problem by creating new antibiotics and enhancing the functionality of the existing ones.

PATIENTS AND METHODS

In the present study, ciprofloxacin was conjugated to biogenic gold nanoflowers (GNFs) from Bacillus subtilis RSB64 by a robust adsorption method under optimized conditions. The resultant drug-nanoflower conjugate was characterized by UV-visible spectroscopy and Fourier transform infrared spectroscopy (FTIR). Addition of ciprofloxacin to gold nanoflowers changed the extinction spectrum towards longer wavelength. The ciprofloxacin-conjugated gold nanoflowers were tested for the drug release statistically. The prepared nanoflower-drug conjugate was subjected to an in vitro microbiological assay against different Gram-positive and Gram-negative bacterial strains to verify the effect of GNF-ciprofloxacin conjugate on the cell growth inhibitory activity of ciprofloxacin.

RESULTS

The GNF-ciprofloxacin conjugates demonstrated enhanced bactericidal activity against Gram-negative bacteria as compared to Gram-positive. The enhancement of the antibacterial activity of the nanoflower-drug conjugate could be attributed to the interaction of the conjugate with phosphate/amine group of the outer membrane of Gram-negative bacterial cell wall making them susceptible to the antibacterial effect of the conjugate.

CONCLUSION

This study demonstrates the positive attributes of GNF-ciprofloxacin conjugates as a promising antibacterial therapeutic agent against pathogens.

Highly Sensitive Detection of the Antibiotic Ciprofloxacin by Means of Fiber Enhanced Raman Spectroscopy

Sepsis and septic shock exhibit a rapid course and a high fatality rate. Antibiotic treatment is time-critical and precise knowledge of the antibiotic concentration during the patients’ treatment would allow individual dose adaption. Over- and underdosing will increase the antimicrobial efficacy and reduce toxicity. We demonstrated that fiber enhanced Raman spectroscopy (FERS) can be used to detect very low concentrations of ciprofloxacin in clinically relevant doses, down to 1.5 µM. Fiber enhancement was achieved in bandgap shifted photonic crystal fibers. The high linearity between the Raman signals and the drug concentrations allows a robust calibration for drug quantification. The needed sample volume was very low (0.58 µL) and an acquisition time of 30 s allowed the rapid monitoring of ciprofloxacin levels in a less invasive way than conventional techniques. These results demonstrate that FERS has a high potential for clinical in-situ monitoring of ciprofloxacin levels.

Treatment responses to Azithromycin and Ciprofloxacin in uncomplicated Salmonella Typhi infection: A comparison of Clinical and Microbiological Data from a Controlled Human Infection Model

BACKGROUND

The treatment of enteric fever is complicated by the emergence of antimicrobial resistant Salmonella Typhi. Azithromycin is commonly used for first-line treatment of uncomplicated enteric fever, but the response to treatment may be sub-optimal in some patient groups when compared with fluoroquinolones.

METHODS

We performed an analysis of responses to treatment with azithromycin (500mg once-daily, 14 days) or ciprofloxacin (500mg twice-daily, 14 days) in healthy UK volunteers (18-60 years) enrolled into two Salmonella controlled human infection studies. Study A was a single-centre, open-label, randomised trial. Participants were randomised 1:1 to receive open-label oral ciprofloxacin or azithromycin, stratified by vaccine group (Vi-polysaccharide, Vi-conjugate or control Men-ACWY vaccine). Study B was an observational challenge/re-challenge study, where participants were randomised to challenge with Salmonella Typhi or Salmonella Paratyphi A. Outcome measures included fever clearance time, blood-culture clearance time and a composite measure of prolonged treatment response (persistent fever ≥38.0°C for ≥72 hours, persistently positive S. Typhi blood cultures for ≥72 hours, or change in antibiotic treatment). Both trials are registered with ClinicalTrials.gov (NCT02324751 and NCT02192008).

FINDINGS

In 81 participants diagnosed with S. Typhi in two studies, treatment with azithromycin was associated with prolonged bacteraemia (median 90.8 hours [95% CI: 65.9-93.8] vs. 20.1 hours [95% CI: 7.8-24.3], p<0.001) and prolonged fever clearance times <37.5°C (hazard ratio 2.4 [95%CI: 1.2-5.0]; p = 0.02). Results were consistent when studies were analysed independently and in a sub-group of participants with no history of vaccination or previous challenge. A prolonged treatment response was observed significantly more frequently in the azithromycin group (28/52 [54.9%]) compared with the ciprofloxacin group (1/29 [3.5%]; p<0.001). In participants treated with azithromycin, observed systemic plasma concentrations of azithromycin did not exceed the minimum inhibitory concentration (MIC), whilst predicted intracellular concentrations did exceed the MIC. In participants treated with ciprofloxacin, the observed systemic plasma concentrations and predicted intracellular concentrations of ciprofloxacin exceeded the MIC.

INTERPRETATION

Azithromycin at a dose of 500mg daily is an effective treatment for fully sensitive strains of S. Typhi but is associated with delayed treatment response and prolonged bacteraemia when compared with ciprofloxacin within the context of a human challenge model. Whilst the cellular accumulation of azithromycin is predicted to be sufficient to treat intracellular S. Typhi, systemic exposure may be sub-optimal for the elimination of extracellular circulating S. Typhi. In an era of increasing antimicrobial resistance, further studies are required to define appropriate azithromycin dosing regimens for enteric fever and to assess novel treatment strategies, including combination therapies.

TRIAL REGISTRATION

ClinicalTrials.gov (NCT02324751 and NCT02192008).

An evaluation of reports of ciprofloxacin, levofloxacin, and moxifloxacin-association neuropsychiatric toxicities, long-term disability, and aortic aneurysms/dissections disseminated by the Food and Drug Administration and the European Medicines Agency

Introduction: Ciprofloxacin, levofloxacin, and moxifloxacin belong to the fluoroquinolone class of antibiotics and are amongst the most commonly prescribed antibiotics. In 2018 and 2019, Food and Drug Administration (FDA) and the European Medicine Agency (EMA) requested that manufacturers harmonize FQ safety information related to neuropsychiatric, aortic dissection, and long-term disability. The authors hypothesize that FDA and EMA epidemiologists support a strong association between these drugs and the three toxicities. Areas covered: Studies of FQ-associated neuropsychiatric toxicity, long-term disability, and aortic ruptures/dissections. Clinical sources include FDA Advisory Committee documents, a 2014 Citizen Petition filed with the FDA requesting safety information additions to FQ labels for neuropsychiatric toxicities (partially granted in 2018), an under-review Citizen Petition under review by the FDA requesting a FQ Risk Evaluation and Mitigation Strategy, and safety notifications from the EMA. Expert opinion: FDA and the EMA report state that neuropsychiatric toxicity, long-term disability, and aortic dissections//aneurysms occur with all FQs. Disability and neuropsychiatric toxicity can occur after one dose or several months after FQs. United States' and European' regulators warn physicians not to prescribe FQs for uncomplicated acute urinary tract infection, sinusitis, or bronchitis, unless other possible choices are tried first, as risks outweigh benefits in these settings.

Evaluation of prophylactic antibiotic regimens on recurrence and mortality in spontaneous bacterial peritonitis

INTRODUCTION AND OBJECTIVES

Limited data describe current SBP epidemiology and specific secondary SBP prophylactic regimens, leading to variable prescribing practices. This work aims to compare 90-day and one-year SBP recurrence and mortality based on secondary SBP antibiotic prophylaxis regimens.

MATERIALS AND METHODS

We performed a retrospective cohort of patients >18 years with an SBP diagnosis from 2010 to 2015 at two academic institutions. Eligible patients had ascitic PMN counts ≥250cells/mm3 or a positive ascitic culture. Patients were compared based on secondary SBP prophylaxis regimens (i.e., daily, intermittent, or no prophylaxis).

RESULTS

Of 791 patients with ascitic fluid samples, 86 patients were included. Antibiotic prophylaxis included daily (n=34), intermittent (n=36), or no prophylaxis (n=16). Nearly half of SBP episodes had a positive ascitic fluid culture; 50% were gram-negative pathogens, and 50% were gram-positive pathogens. Daily and intermittent regimens had similar rates of recurrence at 90-days (19.4% vs. 14.7%, p=0.60) and one-year (33.3% vs. 26.5%, p=0.53). Similarly, mortality did not differ among daily and intermittent regimens at 90-days (32.4% vs. 30.6%, p=0.87) or one-year (67.6% vs. 63.9%, p=0.74). When comparing any prophylaxis vs. no prophylaxis, there were no differences in 90-day or one-year recurrence or mortality.

CONCLUSIONS

In patients with a history of SBP, our data indicate similar outcomes with daily, intermittent, or no secondary antibiotic prophylaxis. With available data, including ours, demonstrating a changing epidemiology for SBP pathogens, further data is required to determine if traditional approaches to secondary SBP prophylaxis remain appropriate.

A Physiologically-Based Pharmacokinetic Model to Describe Ciprofloxacin Pharmacokinetics Over the Entire Span of Life

Background

Physiologically-based pharmacokinetic (PBPK) modeling has received growing interest as a useful tool for the assessment of drug pharmacokinetics by continuous knowledge integration.

Objective

The objective of this study was to build a ciprofloxacin PBPK model for intravenous and oral dosing based on a comprehensive literature review, and evaluate the predictive performance towards pediatric and geriatric patients.

Methods

The aim of this report was to establish confidence in simulations of the ciprofloxacin PBPK model along the development process to facilitate reliable predictions outside of the tested adult age range towards the extremes of ages. Therefore, mean data of 69 published clinical trials were identified and integrated into the model building, simulation and verification process. The predictive performance on both ends of the age scale was assessed using individual data of 258 subjects observed in own clinical trials.

Results

Ciprofloxacin model verification demonstrated no concentration-related bias and accurate simulations for the adult age range, with only 4.8% of the mean observed data points for intravenous administration and 12.1% for oral administration being outside the simulated twofold range. Predictions towards the extremes of ages for the area under the plasma concentration–time curve (AUC) and the maximum plasma concentration (C_max) over the entire span of life revealed a reliable estimation, with only two pediatric AUC observations outside the 90% prediction interval.

Conclusion

Overall, this ciprofloxacin PBPK modeling approach demonstrated the predictive power of a thoroughly informed middle-out approach towards age groups of interest to potentially support the decision-making process.

Electronic supplementary material

The online version of this article (10.1007/s40262-018-0661-6) contains supplementary material, which is available to authorized users.

Electrospun Chitosan/Poly (Vinyl Alcohol)/Graphene Oxide Nanofibrous Membrane with Ciprofloxacin Antibiotic Drug for Potential WoundDressing Application

In this paper, nanofibrous membranes based on chitosan (CS), poly (vinyl alcohol) (PVA) and graphene oxide (GO) composites, loaded with antibiotic drugs, such as Ciprofloxacin (Cip) and Ciprofloxacin hydrochloride (CipHcl) were prepared via the electrospinning technique. The uniform and defect-free CS/PVA nanofibers were obtained and GO nanosheets, shaping spindle and spherical, were partially embedded into nanofibers. Besides, the antibiotic drugs were effectively loaded into the nanofibers and part of which were absorbed into GO nanosheets. Intriguingly, the release of the drug absorbed in GO nanosheets regulated the drug release profile trend, avoiding the "burst" release of drug at the release initial stage, and the addition of GO slightly improved the drug release ratio. Nanofibrous membranes showed the significantly enhanced antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus subtilis after the addition of antibiotic drug. Moreover, the drug-loaded nanofibrous membranes exhibited excellent cytocompatibility with Melanoma cells, indicative to the great potential potential for applications in wound dressing.

In vitro drug release behavior of Ce-doped nano-bioactive glass carriers under oxidative stress

Ce-containing bioactive glasses are known to decrease reactive oxygen activities inside the body. That is because of their excellent catalytic activities which come from the fast interchange of Ce³⁺/Ce⁴⁺ oxidation states. This research was mainly aimed at preparing new Ce-doped nano-bioactive glasses based on 60SiO₂-(10-x)B₂O₃-25CaO-5P₂O₅-xCeO₂, in mole% (x = 0 and 5 mol%) as multifunctional bone fillings. Moreover, the glasses were used as a delivery system for ciprofloxacin to intensely solve the bone infection complications. Nevertheless, there were no previous works studied of the nature immersing solution effect on the drug release behavior from Ce-doped nano-bioactive glass carriers. Therefore, phosphate-free and phosphate-containing buffer solutions with/without superoxide species (H₂O₂) were used to investigate the efficacy of this drug delivery system in different environment. The results showed that Ce addition enhanced the formation of apatite layer and cell viability. Moreover, the percentage of released drug was apparently affected by the glass composition and nature of soaking fluid, specifically, in the media containing superoxide species (H₂O₂). In conclusion, the prepared Ce-doped glass nanoparticles illustrated multifunctional bone filling material, but when it intended to be utilized as a drug delivery system, the nature of surrounding medium have to be taken into consideration.

Combination of berberine and ciprofloxacin reduces multi-resistant Salmonella strain biofilm formation by depressing mRNA expressions of luxS, rpoE, and ompR

Bacterial biofilms have been demonstrated to be closely related to clinical infections and contribute to drug resistance. Berberine, which is the main component of Coptis chinensis, has been reported to have efficient antibacterial activity. This study aimed to investigate the potential effect of a combination of berberine with ciprofloxacin (CIP) to inhibit Salmonella biofilm formation and its effect on expressions of related genes (rpoE, luxS, and ompR). The fractional inhibitory concentration (FIC) index of the combination of berberine with CIP is 0.75 showing a synergistic antibacterial effect. The biofilm's adhesion rate and growth curve showed that the multi-resistant Salmonella strain had the potential to form a biofilm relative to that of strain CVCC528, and the antibiofilm effects were in a dose-dependent manner. Biofilm microstructures were rarely observed at 1/2 × MIC/FIC concentrations (MIC, minimal inhibition concentration), and the combination had a stronger antibiofilm effect than each of the antimicrobial agents used alone at 1/4 × FIC concentration. LuxS, rpoE, and ompR mRNA expressions were significantly repressed (p ＜ 0.01) at 1/2 × MIC/FIC concentrations, and the berberine and CIP combination repressed mRNA expressions more strongly at the 1/4 × FIC concentration. The results indicate that the combination of berberine and CIP has a synergistic effect and is effective in inhibiting Salmonella biofilm formation via repression of luxS, rpoE, and ompR mRNA expressions.

Revascularization in Immature and Mature Teeth with Necrotic Pulp: A Clinical Study

AIM

The aim of this in vivo study was to evaluate the revascularization procedure both in immature and mature teeth with necrotic pulp and open apices, disinfected with triple antibiotic paste followed by inducing blood clot in the root canal.

MATERIALS AND METHODS

Fifteen patients were selected who presented with immature and mature permanent teeth with pulpal necrosis and open apices. In the first visit, the root canal was accessed with LA and rubber dam isolation; then the canal was disinfected using triple antibiotic paste containing ciprofloxacin, metronidazole, and clindamycin in the ratio of 1:1:1 and closed with IRM. In the second visit, after administering local anesthesia and isolating with a rubber dam, the triple antibiotic paste was washed out by saline irrigation, and apical papilla beyond the confines of the root canal was stimulated with sterile H file to produce a blood clot. Finally, the access was closed using a double seal with mineral trioxide aggregate (MTA) placed apical to cementoenamel junction and resin bonded cement over the MTA. Radiographic examination and pulp sensibility test was done during the follow-up period of 2,4,6,8 and 10 months.

RESULT

After 10 months follow-up, 10 out of 13 patients showed root development and apical closure. The eight patients out of 13 showed root development, apical closure and lateral thickening of radicular dentin and 2 out of 13 patients showed a positive response to electric sensibility test.

CONCLUSION

Within the limitation of this study, it can be concluded that there is evidence of root development, increase in lateral wall thickness, apical closure and positive response to pulp sensibility test in both mature and immature teeth with necrotic pulp.

CLINICAL SIGNIFICANCE

The conventional approach for management of teeth with necrotic pulp and the open apex is altered with the possibility of tissue regeneration within the pulp space and continued root development through revascularization procedures. It also re-establishes the vitality in a previously nonvital and necrosed tooth.

Macrophage-targeted drugamers with enzyme-cleavable linkers deliver high intracellular drug dosing and sustained drug pharmacokinetics against alveolar pulmonary infections

Intracellular bacterial infections localized to the lung alveolar macrophage (AM) remain one of the most challenging settings for antimicrobial therapy. Current systemic antibiotic treatment fails to deliver sustained doses to intracellular bacterial reservoirs, which necessitates prolonged treatment regimens. Herein, we demonstrate a new intracellular enzyme-cleavable polymeric prodrug with tailored ciprofloxacin release profiles in the lungs and AM. The targeted polymeric prodrug, termed "drugamers", incorporates (1) hydrophilic mannose residues to solubilize the antibiotic cargo and to target and enhance AM uptake and intracellular delivery, and (2) enzyme-cleavable linkage chemistry to provide high and sustained intracellular AM drug dosing. Prodrug monomers, derived from the antibiotic ciprofloxacin, were synthesized with either an intracellular protease cleavable dipeptide linker or a hydrolytic phenyl ester linker. RAFT polymerization was used to copolymerize the prodrug monomers and mannose monomer to synthesize well-defined drugamers without requiring a post-polymerization conjugation step. In addition to favorable in vivo safety profiles following intratracheal administration, a single dose of the drugamers sustained ciprofloxacin dosing in lungs and AMs above the minimum inhibitory concentration (MIC) over at least a 48 h period. The enzyme-cleavable therapeutic achieved a >10-fold increase in sustained ciprofloxacin in AM, and maintained a significantly higher whole lung PK as well. Ciprofloxacin dosed in identical fashion displayed rapid clearance with a half-life of approximately 30 min. Notably, inhalation of the mannose-targeted ciprofloxacin drugamers achieved full survival (100%) in a highly lethal mouse model of pneumonic tularemia, contrasted with 0% survival using free ciprofloxacin. These findings demonstrate the versatility of the drugamer platform for engineering the intracellular pharmacokinetic profiles and its strong therapeutic activity in treating pulmonary intracellular infections.

Bioresponsive Nanoparticles Targeted to Infectious Microenvironments for Sepsis Management

Sepsis is a life-threatening disease resulted from a dysregulated host immune response to bacterial infections, continuing to cause high morbidity and mortality worldwide. Despite discoveries of many potential therapeutic targets, effective treatments of sepsis are lacking. Here, a strategy is reported to target infectious microenvironments (IMEs) via bioresponsive nanoparticles that simultaneously eliminate bacteria and alleviate the host inflammation response, thus managing sepsis in mice. The nanoparticle is made of copolymers sensitive to pH and bacterial enzymes to self-assemble into a micelle loaded with both an antibiotic (ciprofloxacin) and an anti-inflammatory agent ((2-[(aminocarbonyl)amino]-5-(4-fluorophenyl)-3-thiophenecarboxamide). In addition, the nanoparticle is conjugated with intercellular adhesion molecule-1 antibodies to target IMEs. Nanoparticle targeting to IMEs and local cues as triggers to deliver therapeutics in on-demand manners is demonstrated using an acute lung bacterial infection mouse model. In the sepsis mouse model induced by peritonitis at a lethal dose of bacterial invasion, it is shown that concurrently targeting pathogens and excessive inflammation pathways is valuable to manage the sepsis. The study illustrates not only the development of a new delivery system but also the mechanism-based therapy of nanomedicine for infectious diseases.

Association of oral ciprofloxacin, levofloxacin, ofloxacin and moxifloxacin with the risk of serious ventricular arrhythmia: a nationwide cohort study in Korea

OBJECTIVE

To evaluate whether oral ciprofloxacin, levofloxacin, ofloxacin and moxifloxacin increase the risk of ventricular arrhythmia in Korea's general population.

DESIGN

Population-based cohort study using administrative claims data on a national scale in Korea.

SETTING

All primary, secondary and tertiary care settings from 1 January 2015 to 31 December 2015.

PARTICIPANTS

Patients who were prescribed the relevant study medications at outpatient visits.

PRIMARY OUTCOME MEASURES

Each patient group that was prescribed ciprofloxacin, levofloxacin, ofloxacin or moxifloxacin was compared with the group that was prescribed cefixime to assess the risk of serious ventricular arrhythmia (ventricular tachycardia, fibrillation, flutter and cardiac arrest). Using logistic regression analysis with inverse probability of treatment weighting using the propensity score, OR and 95% CI for serious ventricular arrhythmia were calculated for days 1-7 and 8-14 after the patients commenced antibiotic use.

RESULTS

During the study period, 4 888 890 patients were prescribed the study medications. They included 1 466 133 ciprofloxacin users, 1 141 961 levofloxacin users, 1 830 786 ofloxacin users, 47 080 moxifloxacin users and 402 930 cefixime users. Between 1 and 7 days after index date, there was no evidence of increased serious ventricular arrhythmia related to the prescription of ciprofloxacin (OR 0.72; 95% CI 0.49 to 1.06) and levofloxacin (OR 0.92; 95% CI 0.66 to 1.29). Ofloxacin had a 59% reduced risk of serious ventricular arrhythmia compared with cefixime during 1-7 days after prescription. Whereas the OR of serious ventricular arrhythmia after the prescription of moxifloxacin was 1.87 (95% CI 1.15 to 3.11) compared with cefixime during 1-7 days after prescription.

CONCLUSIONS

During 1-7 days after prescription, ciprofloxacin and levofloxacin were not associated with increased risk and ofloxacin showed reduced risk of serious ventricular arrhythmia. Moxifloxacin increased the risk of serious ventricular arrhythmia.

Evaluation of the hepatic effect of concomitant administration of ciprofloxacin and some antimalarial drugs in Plasmodium berghei infected mice: An in vivo study

This study evaluated the hepatotoxic effects of artesunate (AS), artemether-lumefantrine (AL) and artesunate-amodiaquine (ASAQ) co-administration with ciprofloxacin (CIP) using animal model. Chloroquine sensitive Plasmodium berghei NK65 strain infected albino mice (120) were utilized for this study, carried out in three phases. Phase 1 comprised eleven groups treated with different doses of either AS, AL, ASAQ or CIP alone. Phase 2 consisted of nine groups treated with 7mg/kg of CIP combined with different doses of AS, AL, ASAQ. Phase 3 comprised ten groups treated with 14mg/kg of CIP (CIP2) with different doses of AS, AL, ASAQ. Seventy-two hours after administration of drugs, toxicity was determined by evaluating the effect of drugs on liver enzymes using spectrophotometer. Statistical analysis revealed that CIP alone significantly (P<0.05) reduced the levels of Aspartate Transaminase (AST) and Serum Alanine Transaminase (ALT) compared to AS, AL and ASAQ alone. Combination of different doses of AS, AL and ASAQ with 7mg/kg CIP significantly increased the level of AST and ALT while combination of AS, AL and ASAQ with 14mg/kg CIP significantly decreased AST and ALT levels. Care should be taken during the co-administration of low dose ciprofloxacin with artesunate, artemether-lumefantrine or artesunate-amodiaquine.

Mixed pneumonic plague and nosocomial MDR-bacterial infection of lung: a rare case report

BACKGROUND

Plague is a life-threatening disease caused by the bacterium, Yersinia pestis. Madagascar is the leading country for human plague cases worldwide. Human plague is a serious disease, particularly in its septicaemic and pneumonic forms. We report a case of pneumonic plague co-infected by a MDR-Stenotrophomonas maltophilia.

CASE PRESENTATION

A 24 year-old man originated from Soavinandriana, a plague focus, felt uneasy and developed high fever with chills. He started treatment by himself, by private medical care and by a traditional healer for nine days moving several times from place to place. His condition had deteriorated when he presented to a district hospital with a syndrome of dyspnea, bronchial rale and altered state of consciousness. Two days later, plague diagnosis, performed as a last resort, revealed a positive F1 antigen on rapid diagnostic test. Additional tests (pla PCR and plague serology) evidenced a Y. pestis infection. However, streptomycin treatment did not achieve a complete recovery as the course of disease was complicated by the presence of MDR-S. maltophilia in his lung. This opportunistic infection could have been favored by an immunosuppression due to Y. pestis pulmonary infection and probably been acquired during his stay at a District Hospital. He was treated with a combination of ciprofloxacin and gentamycin and recovered fully.

CONCLUSIONS

Pneumonic plague infection may promote another virulent or avirulent bacterial infection particularly when it is not initially suspected. However, coinfection is rarely described and its occurrence frequency is unknown. In middle or low resources areas, which is the case of most plague endemic countries, control and prevention of infections in health facilities is not optimal. Co-infection with an opportunistic pathogen agent, such as S. maltophilia, is a risk which must not be disregarded as demonstrated by this case report. When deciding of a national control strategy, it should be taken into account in the choice of the first line treatment.

Malignant external otitis following radiotherapy for oral cancer: A case report

RATIONALE

Although an ototoxicity is well-known as adverse event of the radiotherapy, it is not widely known that immunosuppressed patients who underwent radiotherapy in head and neck region have risk of malignant external otitis.

PATIENT CONCERNS

A 68-year-old man with diabetes, who had been diagnosed as intraosseous squamous cell carcinoma of the right mandible, underwent surgical resection. He received a total of 60 Gy/30Fr postoperative radiation. Four months after the course of radiation, he suffered from right aural fullness, otalgia and otorrhea.

DIAGNOSES

Clinical examination revealed granulation and existence of Pseudomonas aeruginosa in the external auditory canal. Computed tomography showed expansive inflammation and erosion in the temporal bone. The patient is elderly and diabetes. These findings led to the diagnosis of malignant external otitis.

INTERVENTIONS

The ear irrigation and administration of quinolones were started. Afterwards, fistula was formed in the oral cavity, and connected to the right external auditory canal. Therefore, irrigations were performed not only from ear but also from the oral fistula.

OUTCOMES

Eight weeks after starting treatment, the malignant external otitis was completely healed.

LESSONS

Physicians should raise awareness of malignant external otitis in immunosuppressed patients with oral cancer after radiotherapy.

Evaluation of Efficacy and Safety of Ciprofloxacin Ophthalmic Solution versus Chloramphenicol

The results of this clinical study demonstrate that ciprofloxacin ophthalmic solution 0.3% is as safe and as effective as 0.5% chloramphenicol ophthalmic solution in the treatment of conjunctivitis and blepharitis of bacterial aetiology. Both agents achieved microbiological improvement rates in excess of 90% after 1 week's treatment. On ciprofloxacin 93.5% of patients were judged clinically cured or improved versus 84.6% on chloramphenicol after 1 week. There were no serious adverse affects. One patient in each group suffered drug-related side-effects (chemosis, erythema) which resolved on discontinuation or changing of therapy. Cirpofloxacin is not associated with the rare, but serious, side effect of aplastic anaemia which is associated with chloramphenicol use. On the evidence of this study ciprofloxacin would appear to be an appropriate agent for general use as a topical ophthalmic formulation.

Ciprofloxacin Ophthalmic Solution in the Treatment of Conjunctivitis and Blepharitis: A Comparison with Fusidic Acid

The efficacy and safety of ciprofloxacin ophthalmic solution (0.3%) and fusidic acid gel (1%) were compared in the treatment of bacterial conjunctivitis and blepharitis in a randomized, open, parallel group study. Thirty-nine patients, 21 treated with ciprofloxacin solution and 18 treated with fusidic acid gel, were culture-positive on admission and were evaluable for efficacy. At the end of a 7-day treatment, the infecting organism was eradicated in 81% of those treated with ciprofloxacin and 72% of those treated with fusidic acid gel. There was clinical cure or improvement in 95% and 89% respectively. The clinical cure rate appeared to be higher with ciprofloxacin than fusidic acid (62% compared with 28%) but this was related to the higher proportion of patients with acute conjunctivitis in the ciprofloxacin group. Two patients using ciprofloxacin had mild discomfort and stinging on instillation and one given fusidic acid had moderate edema and discomfort; the latter patient stopped treatment. Topical ciprofloxacin is effective and well tolerated and is a useful treatment of bacterial conjunctivitis and blepharitis.

Topical Ciprofloxacin in the Treatment of Blepharitis and Blepharoconjunctivitis

An international multicentre study assessed the clinical and antibacterial efficacy of a new topical ophthalmic formulation of the quinolone antimicrobial agent ciprofloxacin and compared it with that of tobramycin ophthalmic solution in patients with blepharitis and blepharoconjunctivitis. The study consisted of a randomised double-masked between-group evaluation of 464 patients, 230 of whom were treated with ciprofloxacin and 234 with tobramycin. There was qualitative and quantitative bacteriology, and clinical assessment of ocular symptoms and signs before and after a seven-day course of treatment. Bacteriological cultures demonstrated eradication or reduction of potentially pathogenic bacteria in 93.7% of eyes (ciprofloxacin) versus 88.9% of eyes (tobramycin), seven days after starting treatment. Clinically more than 80% of patients in both treatment groups were cured or improved after seven days. No statistically significant differences were observed between the two treatment groups. No serious side-effects were observed after use of either antimicrobial agent. Ciprofloxacin ophthalmic solution appears safe and effective. The spectrum of activity and clinical efficacy of this new formulation are discussed in comparison with currently used antimicrobial agents.

Comparative Evaluation of Efficacy and Safety of Ciprofloxacin and Norfloxacin Ophthalmic Solutions

The efficacy and safety of ciprofloxacin ophthalmic solution 0.3% and norfloxacin ophthalmic solution 0.3% in the treatment of bacterial conjunctivitis and blepharitis were compared in a double masked randomised study. A total of 131 patients, 65 treated with ciprofloxacin (42 with conjunctivitis and 23 with blepharitis) and 66 treated with norfloxacin (39 with conjunctivitis and 27 with blepharitis) were enrolled in the study at five centres in France. In the efficacy population, pathogens were eradicated or reduced in 96% (24/25) of patients in the ciprofloxacin group and 89% (24/27) in the norfloxacin group. There was no difference between treatments with regard to eradication of particular pathogens. In the efficacy population, clinical cure or improvement was seen in 96% of the patients (24/25 in the ciprofloxacin group and 26/27 in the norfloxacin group). There were no significant differences between ciprofloxacin and norfloxacin with respect to improvements in four symptoms or ten clinical signs. No serious treatment-related adverse events were reported and both ciprofloxacin and norfloxacin were well tolerated.

[Treatment of vancomycin-resistant enterococcal infections]

Vancomycin-resistant enterococci (VRE) are a growing healthcare concern, and since 2012 the incidence has increased eightfold in Denmark. Treatment options for infections with ampicillin-resistant VRE are sparse, and there are no Danish guidelines concerning this topic. For treatment of uncomplicated VRE urinary tract infections, ciprofloxacin or nitrofurantoin can be used. The mainstay of treatment of bacteraemia and other severe infections caused by VRE is linezolid or high-dose daptomycin. Combination treatment is recommended for complicated infections and/or prolonged therapy.

Effect of Nitric Oxide Synthase Inhibition in Experimental Pseudomonas keratitis in Rabbits

Purpose

The aim of this study was to assess the efficacy of the nitric oxide synthase inhibitor L-NG-nitro-arginine-methyleser (L-NAME) in the treatment of experimental Pseudomonas keratitis.

Methods

Twelve young New Zealand white rabbits were given intrastromal injections of Pseudomonas aeruginosa strains. Twenty-four hours later, the rabbits were randomly divided into four groups: group 1 was treated with topical 0.3% ciprofloxacin drops and a single subconjunctival injection of L-NAME (150 mg/kg); group 2 received topical 0.3% ciprofloxacin drops alone; group 3 received a single subconjunctival injection of L-NAME alone; group 4, the control group, was treated with topical balanced salt solution (BSS) drops. One drop of either ciprofloxacin of BSS was applied at each treatment interval. Twenty-six hours after the start of treatment, the eyes were examined by slit lamp to assess inflammation. Aqueous humor specimens were collected from each eye to measure the nitric oxide concentration. Corneas were removed to count bacteria results.

Results

Slit lamp examination cell scores were significantly lower for groups 1 and 3 than groups 2 and 4 eyes (p = 0.002 to p = 0.004). No viable bacteria were detected in the corneas of groups 1 and 2. Group 3 corneas had significantly fewer bacteria (6.33 ± 0.42 × 103) than group 4 (5.94 ± 0.16 × 104) (p < 0.05). Nitric oxide levels in the aqueous humor were significantly lower for group 1 eyes than for groups 2, 3, or 4 (p = 0.02, p = 0.01, and p = 0.003, respectively).

Conclusions

We conclude that nitric oxide synthase inhibitors may be a useful adjunct but are not a replacement for traditional antibiotic drop therapy.

Epididymo-orchitis caused by enteric organisms in men > 35 years old: beyond fluoroquinolones

Epididymo-orchitis is a common urological condition in men of all ages, causing a unilateral or bilateral swelling of the epididymis and/or testis. It is frequently caused by sexually transmitted infections, Chlamydia trachomatis and Neisseria gonorrheae, as well as common enteric organisms implicated in urinary tract infections. Men over 35 years old may develop epididymo-orchitis associated with enteric organisms, often associated with functional bladder outlet problems such as benign prostatic hyperplasia or urethral stricture disease. Fluoroquinolones, especially ciprofloxacin, have long been the mainstay of treatment for these infections; however, rising resistance to ciprofloxacin in E. coli isolates in Europe and the USA means that there is an unprecedented necessity for alternative antimicrobials with adequate penetration into genital tissues (epididymis and testes) to allow appropriate and comprehensive treatment of epididymo-orchitis in this group of patients.

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 AUC_ELF to AUC_u,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.

Effects of intramuscularly administered enrofloxacin on the susceptibility of commensal intestinal Escherichia coli in pigs (sus scrofa domestica)

BACKGROUND

In the European Union, various fluoroquinolones are authorised for the treatment of food producing animals. Each administration poses an increased risk of development and spread of antimicrobial resistance. The aim of this study was to investigate the impact of parenteral administration of enrofloxacin on the prevalence of enrofloxacin and ciprofloxacin susceptibilities in the commensal intestinal E. coli population.

METHODS

E. coli isolates from faeces of twelve healthy pigs were included. Six pigs were administered enrofloxacin on day 1 to 3 and after two weeks for further three days. The other pigs formed the control group. MIC values were determined. Virulence and resistance genes were detected by PCR. Phylogenetic grouping was performed by PCR. Enrofloxacin and ciprofloxacin were analysed in sedimentation samples by HPLC.

RESULTS

Susceptibility shifts in commensal E. coli isolates were determined in both groups. Non-wildtype E. coli could be cultivated from two animals of the experimental group for the first time one week after the first administration and from one animal of the control group on day 28. The environmental load with enrofloxacin in sedimentation samples showed the highest amount between days one and five. The repeated parenteral administration of enrofloxacin to pigs resulted in rapidly increased MIC values (day 28: MIC up to 4 mg/L, day 35: MIC ≥ 32mg/L). E. coli populations of the control group in the same stable without direct contact to the experimental group were affected.

CONCLUSION

The parenteral administration of enrofloxacin to piglets considerably reduced the number of the susceptible intestinal E. coli population which was replaced by E. coli strains with increased MIC values against enrofloxacin. Subsequently also pigs of the control were affected suggesting a transferability of strains from the experimental group through the environment to the control group especially as we could isolate the same PFGE strains from both pig groups and the environment.