Efficacy of doxycycline therapy for macrolide-resistant Mycoplasma pneumoniae pneumonia in children at different periods.

BACKGROUND: The prevalence of macrolide-resistant Mycoplasma pneumoniae has increased considerably. Treatment in children has become challenging. This study aimed to evaluate the efficacy of doxycycline therapy for macrolide-resistant Mycoplasma pneumoniae pneumonia in children at different periods. METHODS: We retrospectively analyzed the data of patients with macrolide-resistant Mycoplasma pneumoniae pneumonia hospitalized between May 2019 to August 2022. According to treatment, patients were divided into three groups: oral doxycycline treatment alone (DOX group), changed from intravenous azithromycin to oral doxycycline (ATD group), and intravenous azithromycin treatment alone (AZI group). ATD group cases were separated into two sub-groups: intravenous azithromycin treatment<3 days (ATD1 group) and ≥ 3 days (ATD2 group). Clinical symptoms were compared in each group and adjusted by Propensity score matching (PSM) analysis. RESULTS: A total of 106 were recruited in this study. 17 (16%) were in DOX group, 58 (55%) in ATD group, and 31(29%) in AZI group. Compared with ATD group and AZI group, the DOX group showed shorter hospitalization duration and fever duration after treatment, while higher rate of chest radiographic improvement. After using PSM analysis, shorter days to hospitalization duration (P = 0.037) and to fever duration after treatment (P = 0.027) in DOX + ATD1 group than in ATD2 group was observed. A higher number of patients in the DOX + ATD1 group achieved defervescence within 72 h (P = 0.031), and fewer children received glucocorticoid adjuvant therapy (P = 0.002). No adverse reactions associated with doxycycline was observed during treatment. CONCLUSIONS: Children receiving early oral doxycycline had a shorter duration of fever and hospitalization in macrolide-resistant Mycoplasma pneumoniae patients.

Exogenous methionine contributes to reversing the resistance of Streptococcus suis to macrolides.

Streptococcus suis (S. suis) has been increasingly recognized as a porcine zoonotic pathogen that threatens the health of both pigs and humans. Multidrug-resistant Streptococcus suis is becoming increasingly prevalent, and novel strategies to treat bacterial infections caused by these organisms are desperately needed. In the present study, an untargeted metabolomics analysis showed that the significant decrease in methionine content and the methionine biosynthetic pathway were significantly affected by the Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis in drug-resistant S. suis. The addition of L-methionine restored the bactericidal activity of macrolides, doxycycline, and ciprofloxacin on S. suis in vivo and in vitro. Further studies showed that the exogenous addition of methionine affects methionine metabolism by reducing S-adenosylmethionine synthetase activity and the contents of S-adenosylmethionine, S-adenosyl homocysteine, and S-ribose homocysteine. Methionine can decrease the total methylation level and methylesterase activity in multidrug resistant S. suis. The drug transport proteins and efflux pump genes were significantly downregulated in S. suis by exogenous L-methionine. Moreover, the exogenous addition of methionine can reduce the survival of S. suis by affecting oxidative stress and metal starvation in bacteria. Thus, L-methionine may influence the development of resistance in S. suis through methyl metabolism and metal starvation. This study provides a new perspective on the mitigation of drug resistance in S. suis.IMPORTANCEBacterial antibiotic resistance has become a severe threat to human and animal health. Increasing the efficacy of existing antibiotics is a promising strategy against antibiotic resistance. Here, we report that L-methionine enhances the efficacy of macrolides, doxycycline, and ciprofloxacin antibiotics in killing Streptococcus suis, including multidrug-resistant pathogens. We investigated the mechanism of action of exogenous methionine supplementation in restoring macrolides in Streptococcus suis and the role of the methionine cycle pathway on methylation levels, efflux pump genes, oxidative stress, and metal starvation in Streptococcus suis. It provides a theoretical basis for the rational use of macrolides in clinical practice and also identifies a possible target for restoring drug resistance in Streptococcus suis.

[A pharmacologic approach to treatment of Mycobacterium abscessus pulmonary disease]. / Analyse pharmacologique du traitement des pneumopathies à Mycobacterium abscessus.

Mycobacterium abscessus is a fast-growing non-tuberculous mycobacteria complex causing pulmonary infections, comprising the subspecies abscessus, massiliense and bolletii. Differences are based predominantly on natural inducible macrolide resistance, active in most Mycobacterium abscessus spp abscessus species and in Mycobacterium abscessus spp bolletii but inactive in Mycobacterium abscessus spp massiliense. Therapy consists in long-term treatment, combining multiple antibiotics. Prognosis is poor, as only 40% of patients experience cure. Pharmacodynamic and pharmacokinetic data on M. abscessus have recently been published, showing that therapy ineffectiveness might be explained by intrinsic bacterial resistance (macrolides…) and by the unfavorable pharmacokinetics of the recommended antibiotics. Other molecules and inhaled antibiotics are promising.

Clinical Presentations and Treatment Outcomes of Mycoplasma genitalium Infections at a Large New York City Health Care System.

BACKGROUND: Mycoplasma genitalium (MG) is an emerging sexually transmitted infection. Treatment of MG is complicated by increasing resistance to primary treatment regimens, including macrolides and fluoroquinolones. Understanding the various clinical presentations and relative effectiveness of treatments for MG is crucial to optimizing care. METHODS: Patients with a positive MG nucleic acid amplification test between July 1, 2019, and June 30, 2021, at a large health system in New York City were included in a retrospective cohort. Demographics, clinical presentations, coinfections, treatment, and follow-up microbiologic tests were obtained from the electronic medical record. Associations with microbiologic cure were evaluated in bivariate and multivariable logistic regression models. RESULTS: Five hundred two unique patients had a positive MG nucleic acid amplification test result during the study period. Male individuals presented predominantly with urethritis (117 of 187 [63%]) and female individuals with vaginal symptoms (142 of 315 [45%]). Among patients with follow-up testing who received a single antibiotic at the time of treatment, 43% (90 of 210) had persistent infection and 57% (120 of 210) had microbiologic cure. Eighty-two percent of patients treated with moxifloxacin had microbiologic cure compared with 41% of patients receiving azithromycin regimens ( P < 0.001). In multivariable analysis, treatment with moxifloxacin was associated with 4 times the odds of microbiologic cure relative to low-dose azithromycin (adjusted odds ratio [aOR], 4.18; 95% confidence interval, 1.73-10.13; P < 0.01). CONCLUSIONS: Clinical presentations of MG vary, with urethritis or vaginal symptoms in most cases. Among patients who received a single antibiotic, only treatment with moxifloxacin was significantly associated with microbiologic cure relative to low-dose azithromycin.

Current treatment options for Mycobacterium marinum cutaneous infections.

INTRODUCTION: Mycobacterium marinum is a slowly growing photochromogenic nontuberculous mycobacterium that has special growth characteristics. It causes a uniquely human disease, a cutaneous syndrome named fish tank granuloma or swimming pool granuloma because of the strong epidemiological links with water. The treatment of this disease involves the use of different antimicrobials alone and in combination, depending on the severity of the disease. The antibiotics most frequently used are macrolides, tetracyclines, cotrimoxazole, quinolones, aminoglycosides, rifamycins, and ethambutol. Other approaches include the use of surgery in some cases. New treatment options, like new antibiotics, phage therapy, phototherapy, and others are currently being developed with good in vitro experimental results. In any case, the disease is usually a mild one, and the outcome is good in most of the treated patients. AREAS COVERED: We have searched the literature for treatment schemes and drugs used for treatment of M. marinum disease, as well as other therapeutic options. EXPERT OPINION: Medical treatment is the most recommended approach option, as M. marinum is usually susceptible to tetracyclines, quinolones, macrolides, cotrimoxazole, and some tuberculostatic drugs, usually used in a combined therapeutic scheme. Surgical treatment is an option that can be curative and diagnostic in small lesions.

Review of the role of additional treatments including oseltamivir, oral steroids, macrolides, and vitamin supplementation for children with severe pneumonia in low- and middle-income countries.

Background: Pneumonia is a major cause of death in children aged under five years. As children with severe pneumonia have the highest risk of morbidity and mortality, previous studies have evaluated the additional benefit of adjunctive treatments such as oseltamivir, oral steroids, macrolides, and vitamin supplementation that can be added to standard antibiotic management to improve clinical outcomes. The study reviewed the evidence for the role of these additional treatments for children with severe pneumonia in low- and middle-income countries (LMICs). Methods: Four electronic databases were searched for English-language articles between 2000 to 2020. Systematic reviews (SRs) with meta-analyses, comparative cohort studies, and randomised controlled trials (RCTs) from LMICs that reported clinical outcomes for children with severe pneumonia aged between one month to 9 years who received adjunct treatment in addition to standard care were included. Risk of bias of included SRs was assessed using AMSTAR 2, and of individual studies using the Effective Public Health Practice Project (EPHPP) quality assessment tool for quantitative studies. Results: Overall, the search identified 2147 articles, 32 of which were eligible, including 7 SRs and 25 RCTs. These studies evaluated zinc (4 SRs, 17 RCTs), Vitamin D (1 SR, 4 RCTs), Vitamin A (3 SRs, 1 RCT), Vitamin C (1 SR, 2 RCTs) and micronutrients (1 RCT). Most studies reported clinical outcomes of time to improvement, length of stay, and treatment failure (including mortality). No studies of oseltamivir, steroids, or macrolides fulfilling the inclusion criteria were identified. For zinc, pooled analyses from SRs showed no evidence of benefit. Similarly, a Cochrane review and one RCT found that Vitamin A did not improve clinical outcomes. For Vitamin D, an RCT evaluating a single high dose of 100 000 international units (IU) of vitamin D found a reduction in time to improvement, with 38%-40% documented vitamin D deficiency at baseline. However, two other studies of 1000 IU daily did not show any effect, but vitamin D status was not measured. For vitamin C, two studies found a reduction in time to symptom resolution in those with severe disease, with one reporting a shorter length of hospital stay. However, both studies were of weak quality. Most studies excluded malnourished children, and studies which included these children did not report specifically on the effect of micronutrients. Conclusions: This review found that adjunctive zinc and vitamin A, in addition to standard care, does not improve clinical outcomes in children with severe pneumonia in LMICs (strong evidence). However, a reduction in time to symptom resolution was reported with high dose vitamin D supplementation in children with documented vitamin D deficiency (strong evidence from one study) and vitamin C (weak evidence), although further research is needed, especially in underweight children.

Macrolide therapy in Pseudomonas aeruginosa infections causes uL4 ribosomal protein mutations leading to high-level resistance.

OBJECTIVES: Pseudomonas aeruginosa colonizes the cystic fibrosis (CF) airways causing chronic bacterial lung infections. CF patients are routinely treated with macrolides, however, P. aeruginosa is considered insusceptible as consequence of inadequate susceptibility testing leaving resistance mechanism completely overlooked. Here, we investigated a new mechanism of macrolide resistance caused by ribosomal protein mutations. METHODS: Investigating a longitudinal collection of 529 isolates from CF patients and analysing 5758 protein sequences from different sources, mutations in P. aeruginosa's ribosomal proteins connected to macrolide resistance were identified. Using a modified susceptibility testing protocol, isolates harbouring a mutated uL4 ribosomal protein were tested for resistance against macrolide antibiotics and macrolide-induced quorum sensing modulation. Proteome and ribosome profiling were applied to assess the impact of the mutations on the bacterial physiology. RESULTS: Five uL4 mutations were identified in isolates from different CF patients. Most mapped to the conserved loop region of uL4 and resulted in increased macrolide tolerance (>10-fold relative to wt strains). Greater concentrations (>10-fold) of macrolide antibiotic were needed to inhibit the growth, reduce swimming motility, and induce redox sensitivity of the uL4 mutants. 16 proteins involved in ribosome adaptation displayed altered expression possibly to compensate for the uL4 mutations, which changed the ribosome stoichiometry without negatively affecting bacterial physiology. CONCLUSIONS: Macrolide antibiotics should, therefore, be considered as active antimicrobial agents against P. aeruginosa and resistance development should be contemplated when patients are treated with prolonged courses of macrolides. Importantly, improved macrolide susceptibility testing is necessary for the detection of resistant bacteria.

Increased Prevalence of Minocycline-Resistant Staphylococcus epidermidis with tet(M) by Tetracycline Use for Acne Treatment.

Staphylococcus epidermidis, a major skin bacterium, can cause opportunistic infections. Use of antimicrobial agents against Cutibacterium acnes for acne treatment becomes a risk factor for emergence of antimicrobial-resistant skin bacteria. In this study, the impact of antimicrobial treatment of acne vulgaris on S. epidermidis antimicrobial resistance was assessed. A total of 344 S. epidermidis strains isolated from patients with acne vulgaris who visited hospital (165 strains) and dermatological clinics (179 strains), respectively, were analyzed. Except for doxycycline, the resistance rates were higher in strains isolated from patients who had used antimicrobials for acne treatment than in those isolated from patients who had not used antimicrobials. The prevalence rates of strains with erm(C) from patients who used macrolides and clindamycin (hospital, 78.0%; clinics, 61.3%) and those of strains with tet(M) from patients who used tetracyclines (hospital, 27.5%; clinics, 42.4%) were significantly higher than those of strains from patients who did not use antimicrobials (p < 0.05). All strains with erm(A) (8/8) and 91.7% strains with erm(C) (156/170) showed high-level resistance to macrolides and clindamycin (MIC ≥256 µg/mL). Furthermore, almost all strains with tet(M) showed resistance to minocycline. Our results showed that the use of antimicrobials for acne treatment may lead to an increased prevalence of antimicrobial-resistant S. epidermidis. In particular, the emergence of minocycline-resistant strains with tet(M) owing to the use of tetracyclines (doxycycline and minocycline) is a critical issue. Appropriate antimicrobial use for acne treatment may be an important strategy to prevent the emergence of antimicrobial-resistant skin bacteria.

C. acnes qPCR-Based Antibiotics Resistance Assay (ACQUIRE) Reveals Widespread Macrolide Resistance in Acne Patients and Can Eliminate Macrolide Misuse in Acne Treatment.

Background: Macrolides have been widely used to treat moderate-to-severe acne for more than 50 years. However, the prevalent antibiotic resistance of Propionibacterium acnes, along with the absence of clinically available resistance tests, has made macrolide misuse a frequent occurrence around the globe, with serious consequences. Objective: We developed Cutibacterium acnes quantitative PCR (qPCR)-based antibiotics resistance assay (ACQUIRE) to enable fast and accurate detection of C. acnes macrolide resistance in clinical settings, representing an opportunity to administer antibiotics more wisely and improve the quality of care. Methods: A cross-sectional observational study (n = 915) was conducted to probe into the macrolide resistance of C. acnes in patients with acne. Results: The high sensitivity of ACQUIRE enabled us to reveal a much higher C. acnes 23S recombinant DNA (rDNA) point mutation rate (52%) and thus a higher macrolide resistance (75.5%) compared to previous reports. Carriage of ermX gene was discovered on 472 (53%) subjects, which concurs with previous studies. Conclusion: The macrolide resistance of C. acnes is much higher than previously reported. Integrating ACQUIRE into acne treatment modalities may eliminate macrolide misuse and achieve better clinical improvements.

Azithromycin and Ciprofloxacin Treatment Outcomes During an Outbreak of Multidrug-Resistant Shigella sonnei Infections in a Retirement Community-Vermont, 2018.

BACKGROUND: In 2018, the Centers for Disease Control and Prevention and the Vermont Department of Health investigated an outbreak of multidrug-resistant Shigella sonnei infections in a retirement community that offered a continuum of care from independent living through skilled nursing care. The investigation identified 24 culture-confirmed cases. Isolates were resistant to trimethoprim-sulfamethoxazole, ampicillin, and ceftriaxone, and had decreased susceptibility to azithromycin and ciprofloxacin. METHODS: To evaluate clinical and microbiologic response, we reviewed inpatient and outpatient medical records for treatment outcomes among the 24 patients with culture-confirmed S. sonnei infection. We defined clinical failure as diarrhea (≥3 loose stools per day) for ≥1 day after treatment finished, and microbiologic failure as a stool culture that yielded S. sonnei after treatment finished. We used broth microdilution to perform antimicrobial susceptibility testing, and whole genome sequencing to identify resistance mechanisms. RESULTS: Isolates contained macrolide resistance genes mph(A) and erm(B) and had azithromycin minimum inhibitory concentrations above the Clinical and Laboratory Standards Institute epidemiological cutoff value of ≤16 µg/mL. Among 24 patients with culture-confirmed Shigella infection, 4 were treated with azithromycin; all had clinical treatment failure and 2 also had microbiologic treatment failure. Isolates were susceptible to ciprofloxacin but contained a gyrA mutation; 2 patients failed treatment with ciprofloxacin. CONCLUSIONS: These azithromycin treatment failures demonstrate the importance of clinical breakpoints to aid clinicians in identifying alternative treatment options for resistant strains. Additionally, these treatment failures highlight a need for comprehensive susceptibility testing and systematic outcome studies, particularly given the emergence of multidrug-resistant Shigella among an expanding range of patient populations.

Multistep antimicrobial stewardship intervention on antibiotic prescriptions and treatment duration in children with pneumonia.

INTRODUCTION: The Italian antimicrobial prescription rate is one of the highest in Europe, and antibiotic resistance has become a serious problem with high costs and severe consequences, including prolonged illnesses, the increased period of hospitalization and mortality. Inadequate antibiotic prescriptions have been frequently reported, especially for lower respiratory tract infections (LRTI); many patients receive antibiotics for viral pneumonia or bronchiolitis or broad-spectrum antibiotics for not complicated community-acquired pneumonia. For this reason, healthcare organizations need to implement strategies to raise physicians' awareness about this kind of drug and their overall effect on the population. The implementation of antibiotic stewardship programs and the use of Clinical Pathways (CPs) are excellent solutions because they have proven to be effective tools at diagnostic and therapeutic levels. AIMS: This study evaluates the impact of CPs implementation in a Pediatric Emergency Department (PED), analyzing antibiotic prescriptions before and after the publication in 2015 and 2019. The CP developed in 2019 represents an update of the previous one with the introduction of serum procalcitonin. The study aims to evaluate the antibiotic prescriptions in patients with community-acquired pneumonia (CAP) before and after both CPs (2015 and 2019). METHODS: The periods analyzed are seven semesters (one before CP-2015 called PRE period, five post CP-2015 called POST 1-5 and 1 post CP-2019 called POST6). The patients have been split into two groups: (i) children admitted to the Pediatric Acute Care Unit (INPATIENTS), and (ii) patients evaluated in the PED and sent back home (OUTPATIENTS). We have analyzed all descriptive diagnosis of CAP (the assessment of episodes with a descriptive diagnosis were conducted independently by two pediatricians) and CAP with ICD9 classification. All antibiotic prescriptions for pediatric patients with CAP were analyzed. RESULTS: A drastic reduction of broad-spectrum antibiotics prescription for inpatients has been noticed; from 100.0% in the PRE-period to 66.7% in POST1, and up to 38.5% in POST6. Simultaneously, an increase in amoxicillin use from 33.3% in the PRE-period to 76.1% in POST1 (p-value 0.078 and 0.018) has been seen. The outpatients' group's broad-spectrum antibiotics prescriptions decreased from 54.6% PRE to 17.4% in POST6. Both for outpatients and inpatients, there was a decrease of macrolides. The inpatient group's antibiotic therapy duration decreased from 13.5 days (PRE-period) to 7.0 days in the POST6. Antibiotic therapy duration in the outpatient group decreased from 9.0 days (PRE) to 7.0 days (POST1), maintaining the same value in subsequent periods. Overlapping results were seen in the ICD9 group for both inpatients and outpatients. CONCLUSIONS: This study shows that CPs are effective tools for an antibiotic stewardship program. Indeed, broad-spectrum antibiotics usage has dropped and amoxicillin prescriptions have increased after implementing the CAP CP-2015 and the 2019 update.

Genome-Wide Association Study Reveals Genetic Markers for Antimicrobial Resistance in Mycoplasma bovis.

Mycoplasma bovis causes many health and welfare problems in cattle. Due to the absence of clear insights regarding transmission dynamics and the lack of a registered vaccine in Europe, control of an outbreak depends mainly on antimicrobial therapy. Unfortunately, antimicrobial susceptibility testing (AST) is usually not performed, because it is time-consuming and no standard protocol or clinical breakpoints are available. Fast identification of genetic markers associated with acquired resistance may at least partly resolve former issues. Therefore, the aims of this study were to implement a first genome-wide association study (GWAS) approach to identify genetic markers linked to antimicrobial resistance (AMR) in M. bovis using rapid long-read sequencing and to evaluate different epidemiological cutoff (ECOFF) thresholds. High-quality genomes of 100 M. bovis isolates were generated by Nanopore sequencing, and isolates were categorized as wild-type or non-wild-type isolates based on MIC testing results. Subsequently, a k-mer-based GWAS analysis was performed to link genotypes with phenotypes based on different ECOFF thresholds. This resulted in potential genetic markers for macrolides (gamithromycin and tylosin) (23S rRNA gene and 50S ribosomal unit) and enrofloxacin (GyrA and ParC). Also, for tilmicosin and the tetracyclines, previously described mutations in both 23S rRNA alleles and in one or both 16S rRNA alleles were observed. In addition, two new 16S rRNA mutations were possibly associated with gentamicin resistance. In conclusion, this study shows the potential of quick high-quality Nanopore sequencing and GWAS analysis in the evaluation of phenotypic ECOFF thresholds and the rapid identification of M. bovis strains with acquired resistance. IMPORTANCE Mycoplasma bovis is a leading cause of pneumonia but also causes other clinical signs in cattle. Since no effective vaccine is available, current M. bovis outbreak treatment relies primarily on the use of antimicrobials. However, M. bovis is naturally resistant to different antimicrobials, and acquired resistance against macrolides and fluoroquinolones is frequently described. Therefore, AST is important to provide appropriate and rapid antimicrobial treatment in the framework of AMR and to prevent the disease from spreading and/or becoming chronic. Unfortunately, phenotypic AST is time-consuming and, due to the lack of clinical breakpoints, the interpretation of AST in M. bovis is limited to the use of ECOFF values. Therefore, the objective of this study was to identify known and potentially new genetic markers linked to AMR phenotypes of M. bovis isolates, exploiting the power of a GWAS approach. For this, we used high-quality and complete Nanopore-sequenced M. bovis genomes of 100 isolates.

Macrolide and fluoroquinolone resistance of Mycoplasma genitalium in southern Spain, 2018-2019.

OBJECTIVES: In recent years, resistance in Mycoplasma genitalium (MG) to first-line (azithromycin) and second-line (moxifloxacin) treatment has been increasingly reported worldwide, however, no data regarding the south of Spain are available. METHODS: To determine resistance rates, MG-positive samples collected from June 2018 to June 2019 were analysed by sequencing the 23S rRNA and parC genes. RESULTS: A total of 77 patients (24 men having sex with men (MSM), 30 heterosexual men and 23 women) were included. Resistance-associated mutations against macrolide and fluoroquinolones were found in 36.4% (95% CI 25.7% to 48.1%) and 9.1% (95% CI 3.7% to 17.8%) of the patients, respectively. Being MSM and having had another STI in the last year were significantly associated with macrolide-resistant MG infection, while no associations were found with resistance to fluoroquinolones. CONCLUSIONS: Testing for resistance to first-line and second-line drugs against MG should be recommended for the general population and mandatory for the MSM population. We suggest that empiric azithromycin use for STI management should be avoided.

Comparative efficacy and safety of traditional Chinese patent medicine in the treatment of Mycoplasma pneumoniae pneumonia in children: A protocol for systematic review and meta-analysis.

BACKGROUND: Mycoplasma pneumoniae pneumonia (MPP) is a common respiratory disease in children. Its incidence rate is increasing year by year. The drug resistance rate of macrolide antibiotics and other conventional treatment methods is higher, and there are limitations in clinical application. Traditional Chinese patent medicine (TCPM) is a powerful weapon to treat this disease. At present, there is no comparison of the safety and effectiveness of multiple TCPMs in the treatment of MPP in children. Therefore, we take the method of network meta-analysis to systematically compare the efficacy of various TCPMs in the treatment of this disease. METHODS: We will conduct comprehensive searches of Cochrane Library, PubMed, Web of Science, Clinical Trials, China National Knowledge Infrastructure, Chinese Scientific Journals Database, Chinese BioMedical Literature, Wanfang Database, and other electronic databases. The time frame is set from the establishment of the database to October 2020. All randomized controlled trials that meet the inclusion criteria will be included in this study. The 2 researchers will independently screen the literature according to the inclusion criteria, extract the data, and assess the bias risk of the included study. We will evaluate all the obtained data and evidence through Bayesian network meta-analysis, and use Stata 15.0 to process and analyze the data. RESULTS: Through this study, we will evaluate the efficacy and safety of a variety of TCPMs for the treatment of MPP in children. CONCLUSION: The purpose of this study is to provide a strong reference for clinical application of TCPMs in the treatment of MPP in children, and to provide an important basis for clinicians to make correct judgments and put forward accurate treatment plans. ETHICS AND DISSEMINATION: This review does not involve any human or animal experiments and therefore does not require ethical approval. INPLASY REGISTRATION NUMBER: INPLASY 2020100108.

Pharmacotherapeutic management of asthma in the elderly patient.

INTRODUCTION: Asthma is a heterogeneous syndrome with variable phenotypes. Reversible airway obstruction and airway hyper-responsiveness often with an atopic or eosinophilic component is common in the elderly asthmatic. Asthma chronic obstructive pulmonary disease overlap syndrome (ACOS), a combination of atopy-mediated airway hyper-responsiveness and a history of smoking or other environmental noxious exposures, can lead to some fixed airway obstruction and is also common in elderly patients. Little specific data exist for the treating the elderly asthmatic, thus requiring the clinician to extrapolate from general adult data and asthma treatment guidelines. AREAS COVERED: A stepwise approach to pharmacotherapy of the elderly patient with asthma and ACOS is offered and the literature supporting the use of each class of drugs reviewed. EXPERT OPINION: Inhaled, long-acting bronchodilators in combination with inhaled corticosteroids represent the backbone of treatment for the elderly patient with asthma or ACOS . Beyond these medications used as direct bronchodilators and topical anti-inflammatory agents, a stepwise approach to escalation of therapy includes multiple options such as oral leukotriene receptor antagonist or 5-lipoxygense inhibitor therapy, oral phosphodiesterase inhibitors, systemic corticosteroids, oral macrolide antibiotics and if evidence of eosinophilic/atopic component disease exists then modifying monoclonal antibody therapies.

V-ATPase blockade reduces renal gluconeogenesis and improves insulin secretion in type 2 diabetic rats.

Vacuolar H+-adenosine triphosphatase (V-ATPase) stimulates vesicular acidification that may activate cytoplasmic enzymes, hormone secretion and membrane recycling of transporters. We investigated the effect of blockade of V-ATPase by bafilomycin B1 on renal gluconeogenesis, mitochondrial enzymes, and insulin secretion in type 2 diabetic rats. Spontaneous type 2 diabetic Torii rats were treated with intraperitoneal injection of bafilomycin B1 for 1 week, and the kidneys were examined after 24 h of starvation in metabolic cages. The renal expression and activity of V-ATPase were increased in the brush border membrane of the proximal tubules in diabetic rats. The blockade of V-ATPase by bafilomycin B1 reduced renal V-ATPase activity and urinary ammonium in diabetic rats. Treatment with bafilomycin suppressed the enhanced renal gluconeogenesis enzymes and mitochondrial electron transport enzymes in type 2 diabetic rats and reduced the renal cytoplasmic glucose levels. The insulin index and pancreatic insulin granules were decreased in diabetic rats with increased V-ATPase expression in islet cells, and treatment with bafilomycin B1 reversed these changes and increased the insulin secretion index. Hepatosteatosis in type 2 diabetic rats was ameliorated by bafilomycin treatment. As a consequence, treatment with bafilomycin B1 significantly decreased the plasma glucose level after 24 h of starvation in diabetic rats. In conclusion, a V-ATPase inhibitor improved plasma glucose levels in type 2 diabetes by inhibiting renal mitochondrial gluconeogenesis and improving insulin secretion.

In vitro synergistic effect of retapamulin with erythromycin and quinupristin against Enterococcus faecalis.

To find a therapeutic alternative for the treatment of skin and soft tissue infections, we evaluated the effects of combinations of retapamulin with macrolide, lincosamide, and streptogramin (MLS) antibiotics against Staphylococcus aureus, Streptococcus pyogenes, Enterococcus faecium, and Enterococcus faecalis. Using both the disk diffusion test and checkerboard assay, we initially examined the effects of combinations of retapamulin with MLS antibiotics against standard strains of these species. Combinations of retapamulin with erythromycin, quinupristin/dalfopristin and quinupristin showed synergistic activity against E. faecalis only. Synergy of retapamulin with clindamycin and dalfopristin was not observed. Then, a checkerboard assay was performed to evaluate the effects of the combinations against 15 clinical strains of E. faecalis. Retapamulin and quinupristin, the most synergistic combination, showed activity against all erythromycin-susceptible, -intermediate, and -resistant strains tested. Among the eight strains with high-level erythromycin resistance, five strains were synergistically inhibited in the presence of only 1 µg of retapamulin per ml. Time-kill assay revealed that combinations of retapamulin with erythromycin and quinupristin were bacteriostatic. These results suggest that combinations of retapamulin with erythromycin and quinupristin have in vitro synergistic activity against E. faecalis, including strains with high-level erythromycin resistance.

A Common Practice of Widespread Antimicrobial Use in Horse Production Promotes Multi-Drug Resistance.

The practice of prophylactic administration of a macrolide antimicrobial with rifampin (MaR) to apparently healthy foals with pulmonary lesions identified by thoracic ultrasonography (i.e., subclinically pneumonic foals) is common in the United States. The practice has been associated epidemiologically with emergence of R. equi resistant to MaR. Here, we report direct evidence of multi-drug resistance among foals treated with MaR. In silico and in vitro analysis of the fecal microbiome and resistome of 38 subclinically pneumonic foals treated with either MaR (n = 19) or gallium maltolate (GaM; n = 19) and 19 untreated controls was performed. Treatment with MaR, but not GaM, significantly decreased fecal microbiota abundance and diversity, and expanded the abundance and diversity of antimicrobial resistance genes in feces. Soil plots experimentally infected with Rhodococcus equi (R. equi) and treated with MaR selected for MaR-resistant R. equi, whereas MaR-susceptible R. equi out-competed resistant isolates in GaM-treated or untreated plots. Our results indicate that MaR use promotes multi-drug resistance in R. equi and commensals that are shed into their environment where they can persist and potentially infect or colonize horses and other animals.

Resistance-Guided Antimicrobial Therapy Using Doxycycline-Moxifloxacin and Doxycycline-2.5 g Azithromycin for the Treatment of Mycoplasma genitalium Infection: Efficacy and Tolerability.

BACKGROUND: Macrolide resistance in Mycoplasma genitalium (MG) exceeds 50% in many regions, and quinolone resistance is increasing. We recently reported that resistance-guided therapy (RGT) using doxycycline followed by sitafloxacin or 2.5 g azithromycin cured 92% and 95% of macrolide-resistant and macrolide-susceptible infections, respectively. We present data on RGT using doxycycline-moxifloxacin, the regimen recommended in international guidelines, and extend data on the efficacy of doxycycline-2.5 g azithromycin and de novo macrolide resistance. METHODS: Patients attending Melbourne Sexual Health Centre between 2017 and 2018 with sexually transmitted infection syndromes were treated with doxycycline for 7 days and recalled if MG-positive. Macrolide-susceptible cases received 2.5 g azithromycin (1 g, then 500 mg daily for 3 days), and resistant cases moxifloxacin (400 mg daily, 7 days). Test of cure was recommended 14-28 days post-antimicrobials. RESULTS: There were 383 patients (81 females/106 heterosexual males/196 men who have sex with men) included. Microbial cure following doxycycline-azithromycin was 95.4% (95% confidence interval [CI], 89.7-98.0) and doxycycline-moxifloxacin was 92.0% (95% CI, 88.1-94.6). De novo macrolide resistance was detected in 4.6% of cases. Combining doxycycline-azithromycin data with our prior RGT study (n = 186) yielded a pooled cure of 95.7% (95% CI, 91.6-97.8). ParC mutations were present in 22% of macrolide-resistant cases. CONCLUSIONS: These findings support the inclusion of moxifloxacin in resistance-guided strategies and extend the evidence for 2.5 g azithromycin and presumptive use of doxycycline. These data provide an evidence base for current UK, Australian, and European guidelines for the treatment of MG.

Efficacy of Delafloxacin versus Moxifloxacin against Bacterial Respiratory Pathogens in Adults with Community-Acquired Bacterial Pneumonia (CABP): Microbiology Results from the Delafloxacin Phase 3 CABP Trial.

Delafloxacin is a novel fluoroquinolone with activity against Gram-positive, Gram-negative, and atypical pathogens, including fluoroquinolone-nonsusceptible methicillin-resistant Staphylococcus aureus (MRSA). The microbiological results of a phase 3 clinical trial in adults with community-acquired pneumonia (CAP) comparing delafloxacin (300 mg intravenously [i.v.] with the option to switch to 450 mg orally every 12 h) to moxifloxacin (400 mg i.v. with the option to switch to 400 mg orally once a day [QD]) were determined. Patients from 4 continents, predominately Europe but also South America and Asia, were enrolled. The microbiological intent-to-treat (MITT) population included 520 patients, and 60.5% of these patients had a bacterial pathogen identified. Multiple diagnostic methods were employed, including culture, serology, PCR, and urinary antigen tests. Based on baseline MIC90 values, delafloxacin exhibited at least 16-fold greater activity than moxifloxacin for Gram-positive and fastidious Gram-negative pathogens. Delafloxacin retained activity against resistant phenotypes found in Streptococcus pneumoniae (penicillin-, macrolide-, and multiple-drug resistant), Haemophilus species (ß-lactamase producing and macrolide nonsusceptible), and S. aureus (MRSA and fluoroquinolone-nonsusceptible methicillin-susceptible S. aureus [MSSA]). The microbiological success rates were 92.7% for S. pneumoniae (87.5% for penicillin-resistant S. pneumoniae [PRSP]), 92.6% for S. aureus (100% for MRSA), 100% for Escherichia coli, 82.4% for Klebsiella pneumoniae, 100% for Klebsiella oxytoca, 100% for Moraxella catarrhalis, 91.7% for Haemophilus influenzae, 88.6% for Haemophilus parainfluenzae, 96.7% for Mycoplasma pneumoniae, 93.1% for Legionella pneumophila, and 100% for Chlamydia pneumoniae There was little correlation between MICs and outcomes, with a high proportion of favorable outcomes observed across all delafloxacin baseline MIC values. Delafloxacin may be considered a treatment option as monotherapy for CAP in adults, where broad-spectrum coverage including MRSA activity is desirable.