Antimicrobial resistance rates of urogenital Mycoplasma hominis and Ureaplasma species before and during the COVID-19 pandemic: results from a Greek survey, 2014 to 2022.

The prevalence of antibiotic-resistant urogenital mycoplasmas and ureaplasmas has been gradually increasing over the years, leading to greater concern for accurate diagnosis and treatment. In this study, the antimicrobial resistance trends in Greece were analyzed using 2992 Ureaplasma spp. and 371 M. hominis isolates collected between 2014 and 2022. Antibiotic sensitivity was determined using eight different antimicrobial agents (josamycin, pristinamycin, clindamycin, ofloxacin, azithromycin, tetracycline, erythromycin, and doxycycline), with the data analyzed using descriptive statistical methods. Resistance rates to clindamycin and erythromycin increased for both M. hominis and Ureaplasma spp., while remaining relatively low for Tetracycline, Doxycycline, and Ofloxacin. For Ureaplasma spp., high susceptibility was observed to pristinamycin, tetracycline, doxycycline, azithromycin, and josamycin, and intermediate susceptibility to erythromycin. However, the resistance rate for clindamycin dramatically increased from 60% in 2014 to a peak of 98.46% in 2021, and the erythromycin resistance rate increased from 9.54% in 2018 to 22.13% in 2021. M. hominis exhibited consistently high resistance rates to Erythromycin, while Azithromycin resistance significantly increased over time, from 52.78% in 2017 to 97.22% in 2022. The alarming escalation in antibiotic-resistant urogenital mycoplasmas and ureaplasmas in the Greek population is a significant concern. Antibiotic overconsumption may have played a crucial role in increasing resistance trends. The implementation of nationwide surveillance systems, proper antibiotic stewardship policies, and appropriate culture-based therapy policies are necessary to effectively control this emerging risk.

Novel mechanisms of macrolide resistance revealed by in vitro selection and genome analysis in Mycoplasma pneumoniae.

Mycoplasma pneumoniae is an important pathogen causing upper and lower respiratory tract infections in children and other age groups. Macrolides are the recommended treatments of choice for M. pneumoniae infections. However, macrolide resistance in M. pneumoniae is increasing worldwide, which complicates the treatment strategies. The mechanisms of macrolide resistance have been extensively studied focusing on the mutations in 23S rRNA and ribosomal proteins. Since the secondary treatment choice for pediatric patients is very limited, we decided to look for potential new treatment strategies in macrolide drugs and investigate possible new mechanisms of resistance. We performed an in vitro selection of mutants resistant to five macrolides (erythromycin, roxithromycin, azithromycin, josamycin, and midecamycin) by inducing the parent M. pneumoniae strain M129 with increasing concentrations of the drugs. The evolving cultures in every passage were tested for their antimicrobial susceptibilities to eight drugs and mutations known to be associated with macrolide resistance by PCR and sequencing. The final selected mutants were also analyzed by whole-genome sequencing. Results showed that roxithromycin is the drug that most easily induces resistance (at 0.25 mg/L, with two passages, 23 days), while with midecamycin it is most difficult (at 5.12 mg/L, with seven passages, 87 days). Point mutations C2617A/T, A2063G, or A2064C in domain V of 23S rRNA were detected in mutants resistant to the 14- and 15-membered macrolides, while A2067G/C was selected for the 16-membered macrolides. Single amino acid changes (G72R, G72V) in ribosomal protein L4 emerged during the induction by midecamycin. Genome sequencing identified sequence variations in dnaK, rpoC, glpK, MPN449, and in one of the hsdS (MPN365) genes in the mutants. Mutants induced by the 14- or 15-membered macrolides were resistant to all macrolides, while those induced by the 16-membered macrolides (midecamycin and josamycin) remained susceptible to the 14- and 15-membered macrolides. In summary, these data demonstrated that midecamycin is less potent in inducing resistance than other macrolides, and the induced resistance is restrained to the 16-membered macrolides, suggesting a potential benefit of using midecamycin as a first treatment choice if the strain is susceptible.

Prevalence and Antimicrobial Susceptibility of Ureaplasma urealyticum and Mycoplasma hominis in Female Outpatients, 2017 - 2021.

BACKGROUND: The latest region-specific panel of mycoplasma species is often crucial for providing insights into local mycoplasma epidemiology and updating clinical practice guidance. METHODS: We retrospectively reviewed reports of 4,166 female outpatients detected by the mycoplasma identification verification and antibiotic susceptibility kit from the last five years. RESULTS: Among them, > 73.3% of cases with Ureaplasma urealyticum or Mycoplasma hominis single infection or co-infection with both species were susceptible to three tetracyclines and one macrolide (josamycin). Additionally, > 84.8%, ≤ 4.4%, and ≤ 39.6% of the U. urealyticum, M. hominis, and co-infection cases, respectively, were susceptible to clarithromycin and roxithromycin. Four quinolones (ciprofloxacin, ofloxacin, sparfloxacin, and levofloxacin) and three macrolides (azithromycin, erythromycin, and acetylspiramycin) were active against < 48.9% of the isolates. Furthermore, 77.8%, 18.4%, and 7.5% of the M. hominis, U. urealyticum, and co-infection cases, respectively, were susceptible to spectinomycin. CONCLUSIONS: Tetracyclines and josamycin were the best antibiotics for most mycoplasma-infected patients.

Combination Therapy with Betamethasone and Josamycin Demonstrates Superior Therapeutic Efficacy in an NC/Nga Mouse Model of Atopic Dermatitis.

We have previously demonstrated the excellent bactericidal activity of josamycin against Staphylococcus aureus isolated from patients with atopic dermatitis (AD), with therapeutic efficacy equal to that of betamethasone. The present study was designed to evaluate the effectiveness of combination therapy with betamethasone and josamycin for AD. Betametasone (0.1%) and josamycin (0.1%) were topically administered to NC/Nga mice with severe AD-like skin lesions. Skin severity scores, histological changes in skin lesions, and serum immunoglobulin E (IgE) levels were assessed as indicators of therapeutic efficacy. Topical treatment with both drugs suppressed the skin severity score to a greater degree than betamethasone alone. This was associated with a reduction of epidermal thickening, a reduced density of dermal cellular infiltration, a decreased mast cell count in the dermis, and a reduced serum IgE level. In addition, both drugs in combination markedly reduced the expression of interferon (IFN)-γ and interleukin (IL)-4 in auricular lymph node cells, as well as the S. aureus count on the lesioned skin. These results show that simultaneous topical application of both drugs can ameliorate severe AD-like skin lesions in NC/Nga mice. It is suggested that combination therapy with betamethasone and josamycin would be beneficial for control of severe AD lesions colonized by S. aureus by inhibiting the development of both T helper (Th) type 1 (Th1) and Th2 cells and also through elimination of superficially located S. aureus.

Separation of false-positive microplastics and analysis of microplastics via a two-phase system combined with confocal Raman spectroscopy.

In the field of microplastics research, more accurate standardised methods and analytical techniques still need to be explored. In this study, a new method for the microplastics quantitatively and qualitatively analysis by two-phase (ethyl acetate-water) system combined with confocal Raman spectroscopy was developed. Microplastics can be separated from false-positive microplastics in beach sand and marine sediment, attributing to the hydrophobic-lipophilic interaction (HLI) of the two-phase system. Results show that the recovery rates of complex environment microplastics (polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), polyamide 66 (PA 66), polycarbonate (PC) and polyethylene (PE)) are higher than 92.98%. Moreover, the new technique can also be used to detect hydrophobic and lipophilic antibiotics, such as sulfamethoxazole (SMX), erythromycin (EM), madimycin (MD), and josamycin (JOS), which adsorbed on microplastics and are extracted based on the dissolving-precipitating mechanism. This innovative research strategy provides a new scope for further detection of marine environment microplastics and toxic compounds adsorbed on its surface.

Study on a terahertz biosensor based on graphene-metamaterial.

The interaction between the terahertz wave propagating in free space and the sample is weak, which leads to the weak signal of the sample, which cannot meet the detection needs of trace samples. In order to meet the detection of trace samples, a kind of metamaterial absorber (the basic unit of the absorber is composed of gold-high resistance silicon-aluminum three-layer structure) is designed, and the monolayer graphene is transferred on the surface of the metamaterial absorber to construct the graphene-metamaterial absorber heterostructure. The transmission spectrum of the resonant cavity is simulated and measured by terahertz time domain spectroscopy system, and the obvious resonance frequency shift is observed. The results show that the graphene-metamaterial absorber heterostructure can detect josamycin antibiotic solution with concentration of 0.02 mg/L (the mass of josamycin is 0.2 ng). Compared with using the same structure metamaterial absorber to detect josamycin antibiotics, the sensitivity is increased by an order of magnitude. Using graphene-metamaterial heterostructure to detect the relative change of heterostructure reflectivity caused by josamycin antibiotics can reach 40%. The research in this paper provides a new technical means for accurate and rapid detection in terahertz band.

Effects of Josamycin on Scratching Behavior in NC/Nga Mice with Atopic Dermatitis-Like Skin Lesions.

Our previous study showed that chronic skin colonization by Staphylococcus aureus exacerbated atopic dermatitis (AD) and that control of such skin colonization using antibiotic ointment might relieve AD-related skin inflammation. However, the role of S. aureus colonization in the pruritus accompanying AD was not elucidated. The aim of the present study was to evaluate the effect of topically applied josamycin, a macrolide antibiotic, on the scratching behavior of NC/Nga mice with AD-like skin lesions. Josamycin (0.1%) was topically administered to NC/Nga mice with AD-like skin lesions induced by a mite antigen, Dermatophagoides farinae extract, and the therapeutic effects of josamycin were assessed by measurement of the skin severity score, S. aureus colonization, scratching count, and interleukin (IL)-31 mRNA expression in the skin lesions. Topical treatment with josamycin ointment significantly suppressed the increase of the skin severity score in NC/Nga mice. This suppressive effect was associated with decreases in the S. aureus count on the lesioned skin, scratching behavior of mice and IL-31 mRNA expression in the lesions. The present results show that the severity of AD-like skin inflammation in NC/Nga mice is correlated with the level of S. aureus colonization and subsequent IL-31 production in the skin. Therefore, topical application of josamycin to AD lesions colonized by S. aureus would be beneficial for control of AD by eliminating superficially located S. aureus and by suppressing the IL-31-induced scratching behavior.

Universal response method for the quantitative analysis of multi-components in josamycin and midecamycin using liquid chromatography coupled with charged aerosol detector.

Josamycin and midecamycin are consisted of three groups of components with different ultraviolet maximum absorption wavelengths (λmax), which are 231 nm, 280 nm and 205 nm. The quantitative analysis of all these components is challengeable due to the absence of the respective reference substances. To address this problem, universal and reliable methods were developed using high performance liquid chromatography coupled with charged aerosol detector (HPLC-CAD) for the quantitative analysis of components in josamycin and midecamycin. The chromatographic conditions and CAD parameters setting were optimized. Subsequently, the components were identified using HPLC coupled with ion trap/time-of-flight mass spectrometry (IT/TOF MS). The developed methods were validated by assessing linearity, limit of quantitation (LOQ), accuracy, precision and robustness. Good separations were achieved for all components and the adjustment of the filter valve and power function value efficiently improved sensitivity. The developed methods were more comprehensive than current HPLC-UV method. The experimental results demonstrated good linearity with coefficients of determination (R2) greater than 0.999 in the range of 0.002-0.30 mg mL-1. The limits of detection (LOD) were ranging from 1.8 to 2.0 µg·mL-1. The intra-day and inter-day RSD values were less than 2.0 % (n = 6) and 5.6 % (n = 9) respectively. The recoveries were 95.0 %-124.0 % at the spiked concentration levels of 0.05 %, 0.50 %, 0.10 % and 2.5 % with relative standard deviations (RSDs, n = 3) lower than 2.0 %. Finally, the developed methods were successfully applied to the quantitative analysis of minor components and used main components (leucomycin A3 and midecamycin A1) as alternative reference substance of minor components. The overall results demonstrated that the HPLC-CAD was a good alternative for the quantitative analysis of multi-components in 16-membered macrolides.

Direct anti-biofilm effects of macrolides on Acinetobacter baumannii: comprehensive and comparative demonstration by a simple assay using microtiter plate combined with peg-lid.

Recently, opportunistic nosocomial infections caused by Acinetobacter baumannii have become increasingly prevalent worldwide. The pathogen often establishes biofilms that adhere to medical devices, causing chronic infections refractory to antimicrobial therapy. Clinical reports have indicated that some macrolide antibiotics are effective against chronic biofilm-related infections. In this study, we examined the direct anti-biofilm effects of seven macrolides (azithromycin, clarithromycin, erythromycin, josamycin, spiramycin, fidaxomicin, and ivermectin) on A. baumannii using a simple and newly established in vitro assay system for the swift and serial spectrophotometric determinations of two biofilm-amount indexes of viability and biomass. These macrolides were found to possess direct anti-biofilm effects exerting specific anti-biofilm effects not exclusively depending on their bacteriostatic/bactericidal effects. The anti-biofilm effect of azithromycin was found to be the strongest, while those of fidaxomicin and ivermectin were weak and limited. These results provide insights into possible adjunctive chemotherapy with macrolides for A. baumannii infection. Common five macrolides also interfered with the Agrobacterium tumefaciens NTL(pCF218) (pCF372) bioassay system of N-acyl homoserine lactones, providing insights into sample preparation for the bioassay, and putatively suggesting the actions of macrolides as remote signals in bacterial quorum sensing systems.

Characterization of 28 unknown impurities in 16-membered macrolides by liquid chromatography coupled with ion trap/time-of-flight mass spectrometry.

In terms of risk assessment, the study of the impurity profile is important to ensure the safety and effectiveness of drugs in clinical application. Sixteen-membered macrolides are produced by microbial fermentation, and many closely related substances in the product make the components and impurities complicated. In this study, methods were developed to separate and identify the impurities in three representative 16-membered macrolides (josamycin, midecamycin and meleumycin) using a high-performance liquid chromatography coupled to high-resolution ion trap/time-of-flight mass spectrometry (IT-TOF MS). In total, 53 impurities were characterized in the positive mode of electrospray ionization, among which 28 novel impurities were found. The proposed structures of impurities were deduced based on MS/MS data, and the ultraviolet (UV) absorption behaviors of impurities were discussed. In addition to the impurities with maximum absorption wavelengths (λmax) of 231 nm and 280 nm, there was a new group of impurities with λmax of 205 nm in meleumycin, midecamycin and josamycin.

A genome-wide analysis of targets of macrolide antibiotics in mammalian cells.

Macrolide antibiotics, such as erythromycin and josamycin, are natural polyketide products harboring 14- to 16-membered macrocyclic lactone rings to which various sugars are attached. These antibiotics are used extensively in the clinic because of their ability to inhibit bacterial protein synthesis. More recently, some macrolides have been shown to also possess anti-inflammatory and other therapeutic activities in mammalian cells. To better understand the targets and effects of this drug class in mammalian cells, we used a genome-wide shRNA screen in K562 cancer cells to identify genes that modulate cellular sensitivity to josamycin. Among the most sensitizing hits were proteins involved in mitochondrial translation and the mitochondrial unfolded protein response, glycolysis, and the mitogen-activated protein kinase signaling cascade. Further analysis revealed that cells treated with josamycin or other antibacterial agents exhibited impaired oxidative phosphorylation and metabolic shifts to glycolysis. Interestingly, we observed that knockdown of the mitogen-activated protein kinase kinase kinase 4 (MAP3K4) gene, which contributes to p38 mitogen-activated protein kinase signaling, sensitized cells only to josamycin but not to other antibacterial agents. There is a growing interest in better characterizing the therapeutic effects and toxicities of antibiotics in mammalian cells to guide new applications in both cellular and clinical studies. To our knowledge, this is the first report of an unbiased genome-wide screen to investigate the effects of a clinically used antibiotic on human cells.

Mycoplasma hominis profile in women: Culture, kit, molecular diagnosis, antimicrobial resistance, and treatment.

OBJECTIVES: Mycoplasma hominis (M.hominis) infections are sexually transmitted and usually associated with urogenital and respiratory diseases. The aim of our study was to (i) detect M. hominis in the vaginal and urine samples of sexually active women using three different detection methods and (ii) to determine the antimicrobial susceptibility and recurrence after the treatment. METHODS: Both vaginal and urine samples were collected from 110 sexually active women at the Obstetrics and Gynecology Clinic, Baskent University Ankara Hospital, Turkey, between March 2015 and February 2016. The presence of M. hominis in the vaginal and urine samples was detected by in vitro culture, two biochemical diagnostics kits (Mycoplasma IES (Autobio, China) and Mycoplasma IST-2 (BioMérieux, France) and PCR. The antibiotic susceptibility of each sample was tested using the kits. The women positive for M. hominis were treated either singly or along with their sexual partners by tetracycline. RESULTS: M. hominis was detected in 72 of 220 (32.7%) samples (both vaginal and urine). Of which 37 showed contrary results with two different kits and then were confirmed by PCR. In 13 samples the IES kit identified M. hominis missed by IST-2, and in 8 samples the MIST-2 kit identified M. hominis missed by IES, while both kits missed 6 samples that were agar culture positive for M. hominis." The highest susceptibility rate was observed against pristinamycin (100%), followed by 91%, 83%, and 75% for doxycycline, tetracycline, and josamycin, respectively. Twenty-five patients treated with tetracycline were followed after one month. The recurrence of M. hominis was not observed in any of the 18 cases where both sexual partners were treated but recurred in 5 of the 7 singly treated women. CONCLUSIONS: The rate of M. hominis detection was significantly higher in the vaginal samples compared to the urine samples. The probability of detecting M. hominis by IST-2 kit was 1.18 times less than IES kit (p < 0.001). When the relationship between the samples was examined, the difference between IES and IST-2 for detecting M. hominis was statistically significant (p < 0.01). Antibiotic susceptibility tests indicated that the tetracycline group of antibiotics was effective in eliminating M. hominis when given to both the sexual partners.

Analysis of josamycin in three kinds of feed using ultra high performance liquid chromatography with tandem mass spectrometry.

In this study, a new and accurate method based on ultra-high performance liquid chromatography (UHPLC) with electrospray ionisation tandem triple quadrupole mass spectrometry (MS/MS) was developed and validated for the determination of josamycin in three kinds of feeds (compound, concentrated and premix feeds). The optimised sample pretreatment procedure included extracting from the matrix with a mixture of methanol and acetonitrile (1:1, v/v) followed by drying under nitrogen and redissolving in phosphate buffer solution (pH = 8, 0.1 mol/L) followed by purifying using HLB cartridges. Validation of the method was carried out in three different matrices (compound, concentrated and premix feed) by recovery experiments, using samples spiked at concentration levels of 20, 100 and 200 µg/kg. Satisfactory recoveries from 82.4% to 93.0%, with RSDs lower than 17.4% under intermediate precision conditions were obtained in all feed matrices tested. The developed method was applied to commercially samples and josamycin was found frequently in feed containing kitasamycin.

Structure Elucidation of Macrolide Antibiotics Using MSn Analysis and Deuterium Labelling.

The 14- and 16-membered macrolide antibiotics are an important structural class. Ubiquitously produced by a number of bacterial strains, namely actinomycetes, purification and structure elucidation of the wide array of analogs is challenging, both for discovery efforts and methodologies to monitor for byproducts, metabolites, and contaminants. Collision-induced dissociation mass spectrometry offers an attractive solution, enabling characterization of mixtures, and providing a wealth of structural information. However, interpretation of these spectra can be difficult. We present a study of 14- and 16-membered macrolide antibiotics, including MSn analysis for unprecedented depth of coverage, and complimentary analysis with D2O and H218O labeling to elucidate fragmentation mechanisms. These analyses contrast the behaviors of varying classes of macrolides and highlight how analogues can be identified in relation to similar structures, which will provide utility for future studies of novel macrolides, as well as impurities, metabolites, and degradation products of pharmaceuticals. Graphical Abstract.

Josamycin suppresses Prevotella intermedia lipopolysaccharide-induced production of nitric oxide and interleukin-1ß in murine macrophages.

AIMS: Josamycin has immunomodulatory properties independent of its antibacterial actions. This study was designed to explore the influences and associated mechanisms of josamycin upon the generation of proinflammatory mediators in murine macrophages activated with lipopolysaccharide (LPS) from Prevotella intermedia, a pathogenic bacterium associated with periodontal disease. MAIN METHODS: LPS was purified by employing phenol-water extraction protocol. Culture supernatants were analyzed for nitric oxide (NO) and interleukin (IL)-1ß. Real-time PCR and immunoblotting were conducted to quantify mRNA and protein expression, respectively. The expression levels of IL-1ß were analyzed by confocal laser scanning microscopy. NF-κB-dependent SEAP levels were estimated by reporter assay. KEY FINDINGS: Josamycin significantly attenuated NO production elicited by P. intermedia LPS as well as induction of iNOS protein and mRNA in RAW264.7 cells. While the release of IL-1ß from cells stimulated by LPS was suppressed in the presence of josamycin, josamycin failed to reduce the degree of IL-1ß mRNA expression. Josamycin did not reduce the stability of IL-1ß mRNA induced by P. intermedia LPS, at the same time josamycin also failed to suppress the LPS-induced intracellular IL-1ß expression. Josamycin augmented HO-1 induction in cells exposed to P. intermedia LPS, and SnPP, an inhibitor of HO-1 activity, reversed the suppressive impact of josamycin upon NO generation induced by LPS. Josamycin diminished NF-κB transcriptional activity induced by P. intermedia LPS. Further, josamycin enhanced SOCS1 mRNA level in cells activated with LPS. SIGNIFICANCE: Josamycin suppressed P. intermedia LPS-induced generation of NO and IL-1ß in RAW264.7 macrophages via the inhibition of NF-κB activation as well as HO-1 and SOCS1 induction. Josamycin may have benefits as a host modulatory agent in treating periodontal disease.

In Vitro Activities of Miltefosine and Antibacterial Agents from the Macrolide, Oxazolidinone, and Pleuromutilin Classes against Pythium insidiosum and Pythium aphanidermatum.

We tested 29 isolates of Pythium insidiosum and one isolate of Pythium aphanidermatum to investigate their susceptibility to miltefosine and antibacterial drugs from the macrolide, oxazolidinone, and pleuromutilin classes. We found that miltefosine, azithromycin, clarithromycin, josamycin, linezolid, sutezolid, retapamulin, tiamulin, and valnemulin had inhibitory and cidal activity against the pathogens at concentrations ranging from 0.25 to 64 µg/ml. Our results suggest that these antimicrobials are promising candidates for future studies on pythiosis in animals and humans.

Topical Application of Josamycin Inhibits Development of Atopic Dermatitis-Like Skin Lesions in NC/Nga Mice.

BACKGROUND: Patients with atopic dermatitis (AD) have superficial skin colonization by Staphylococcus aureus and an increased number of T helper type 2 (Th2) cells in their peripheral blood. Our previous study showed that josamycin, a macrolide antibiotic, had excellent bactericidal activity against S. aureus strains isolated from AD patients and simultaneously inhibited Th1 and Th2 cell development mediated by Langerhans cells. The purpose of the present study was to evaluate the effect of topical application of josamycin on AD-like skin lesions in NC/Nga mice. METHODS: Josamycin (0.1%) was topically administered to NC/Nga mice with AD-like skin lesions induced by 2, 4, 6-trinitrochlorobenzene (TNCB). The therapeutic effects of josamycin were assessed by measurement of the skin severity scores, histological changes in the lesioned skin, serum levels of total IgE, and expression of interferon (IFN)-γ and interleukin (IL)-4 in lymph nodes and skin lesions. RESULTS: Topical treatment with josamycin significantly suppressed the increase in the skin severity score in NC/Nga mice. This suppressive effect was equal to that of betamethasone, and was associated with a decrease in the density of cellular infiltration into the dermis, the mast cell count in the dermis and the serum IgE level. Furthermore, topical application of josamycin reduced the expression of IFN-γ and IL-4 in auricular lymph node cells and the skin lesions. CONCLUSION: The present results show that topical application of josamycin inhibits the development of AD-like skin lesions in NC/Nga mice. This suggests that topical application of josamycin to AD lesions colonized by S. aureus would be beneficial for control of AD by acting on superficially located S. aureus and by inhibiting the development of Th1 and Th2 cells.This article is open to POST-PUBLICATION REVIEW. Registered readers (see "For Readers") may comment by clicking on ABSTRACT on the issue's contents page.

Synthesis and antibacterial activities of some novel 17, 18-unsaturated carbonyl compounds derivated from josamycin.

Some novel josamycin derivatives bearing an arylalkyl-type side chain were designed and synthesized. By HWE or Wittig reaction, 16-aldehyde group of josamycin analogs were converted into unsaturated carbonyl compounds. They were evaluated for their in vitro antibacterial activities against a panel of respiratory pathogens. 8b and 8e exhibited comparable activities against a panel of respiratory pathogens, especially to resistant ones in the series of desmycarosyl josamycin analogs. Among of all the target molecules, 21 showed the best antibacterial activities.

Evaluation of frequency of paediatric oral liquid medication dosing errors by caregivers: amoxicillin and josamycin.

OBJECTIVE: To study reconstitution and preparation dosing errors of liquid oral medications given by caregivers to children. METHODS: A prospective observational study was carried out in the departments of general paediatrics and emergency paediatrics at the Robert-Debré Children's University Hospital. An interview with caregivers involved (1) practical reconstitution and preparation of an oral liquid medication from a prescription drawn at random (amoxicillin (Clamoxyl, dosing spoon) or josamycin (Josacine, dose-weight pipette)) and (2) a questionnaire about their use. RESULTS: One hundred caregivers were included. Clamoxyl and Josacine were incorrectly reconstituted in 46% (23/50) and 56% (28/50) of cases, respectively, with a risk of underdosing of Clamoxyl (16/23) and overdosing of Josacine (23/28). Dose preparation with the dosing spoon was incorrect in 56% of cases, and in 10% of cases with the dose-weight pipette. Female sex, native French speaker, and age were significantly associated with correct reconstitution. Male sex and medication were significantly associated with correct preparation. CONCLUSIONS: This study highlights the high incidence of errors made by caregivers in reconstituting and preparing doses of these liquid oral medicines, which are associated with considerable risks of over- and underdosing. Factors associated with these errors have been identified which could help health professionals to optimise their strategy for educating families about the use of liquid oral medications and the need to check that they understand these instructions.