Antibiotic therapy as personalized medicine - general considerations and complicating factors

Tunable ciprofloxacin delivery through personalized electrospun patches for tympanic membrane perforations

Approximately 740 million symptomatic patients are affected by otitis media every year. Being an inflammatory disease affecting the middle ear, it is one of the primary causes of tympanic membrane (TM) perforations, often resulting in impaired hearing abilities. Antibiotic therapy using broad-spectrum fluoroquinolones, such as ciprofloxacin (CIP), is frequently employed and considered the optimal route to treat otitis media. However, patients often get exposed to high dosages to compensate for the low drug concentration reaching the affected site. Therefore, this study aims to integrate tissue engineering with drug delivery strategies to create biomimetic scaffolds promoting TM regeneration while facilitating a localized release of CIP. Distinct electrospinning (ES) modalities were designed in this regard either by blending CIP into the polymer ES solution or by incorporating nanoparticles-based co-ES/electrospraying. The combination of these modalities was investigated as well. A broad range of release kinetic profiles was achieved from the fabricated scaffolds, thereby offering a wide spectrum of antibiotic concentrations that could serve patients with diverse therapeutic needs. Furthermore, the incorporation of CIP into the TM patches demonstrated a favorable influence on their resultant mechanical properties. Biological studies performed with human mesenchymal stromal cells confirmed the absence of any cytotoxic or anti-proliferative effects from the released antibiotic. Finally, antibacterial assays validated the efficacy of CIP-loaded scaffolds in suppressing bacterial infections, highlighting their promising relevance for TM applications.

Influence of β-lactam pharmacodynamics on the systems microbiology of gram-positive and gram-negative polymicrobial communities

Objectives

We sought to evaluate the pharmacodynamics of β-lactam antibacterials against polymicrobial communities of clinically relevant gram-positive and gram-negative pathogens.

Methods

Two Enterococcus faecalis isolates, two Staphylococcus aureus isolates, and three Escherichia coli isolates with varying β-lactamase production were evaluated in static time-killing experiments. Each gram-positive isolate was exposed to a concentration array of ampicillin (E. faecalis) or cefazolin (S. aureus) alone and during co-culture with an E. coli isolate that was β-lactamase-deficient, produced TEM-1, or produced KPC-3/TEM-1B. The results of the time-killing experiments were summarized using an integrated pharmacokinetic/pharmacodynamics analysis as well as mathematical modelling to fully characterize the antibacterial pharmacodynamics.

Results

In the integrated analysis, the maximum killing of ampicillin (Emax) against both E. faecalis isolates was ≥ 4.11 during monoculture experiments or co-culture with β-lactamase-deficient E. coli, whereas the Emax was reduced to ≤ 1.54 during co-culture with β-lactamase-producing E. coli. In comparison to monoculture experiments, culturing S. aureus with KPC-producing E. coli resulted in reductions of the cefazolin Emax from 3.25 and 3.71 down to 2.02 and 2.98, respectively. Two mathematical models were created to describe the interactions between E. coli and either E. faecalis or S. aureus. When in co-culture with E. coli, S. aureus experienced a reduction in its cefazolin Kmax by 24.8% (23.1%RSE). Similarly, β-lactamase-producing E. coli preferentially protected the ampicillin-resistant E. faecalis subpopulation, reducing Kmax,r by 90.1% (14%RSE).

Discussion

β-lactamase-producing E. coli were capable of protecting S. aureus and E. faecalis from exposure to β-lactam antibacterials.

A bismuth-based double-network hydrogel-mediated synergistic photothermal-chemodynamic therapy for accelerated wound healing

Multidrug-resistant bacterial infections present a significant challenge to wound healing. Non-antibiotic approaches such as photothermal therapy (PTT) and chemodynamic therapy (CDT) are promising but have suboptimal anti-bacterial efficacy. Herein, we developed a green bismuth-based double-network hydrogel (Bi@P-Cu) as a PTT/CDT synergistic platform for accelerated drug-resistant bacteria-infected wound healing. Bismuth (Bi) nanoparticles fabricated using a microwave method were used as a highly efficient and biocompatible PTT agent while the integration of a small amount of CDT agent Cu2+ endowed the hydrogel with excellent mechanical and self-healing properties, markedly increased photothermal efficiency, promoted cell migration ability, and negligible toxicity. Importantly, PTT enhanced the production of hydroxyl radicals in CDT and the destruction of bacterial cell membranes, which in turn enhanced the thermal sensitivity of bacteria. This synergistic anti-bacterial effect, together with the demonstrated capability to promote angiogenesis and anti-inflammation as well as enhanced fibroblast proliferation, led to accelerated wound healing in a full-thickness mouse model of resistant bacterial infection. This study provides an effective and safe strategy to eliminate drug-resistant bacteria and accelerate wound healing through green, non-antibiotic, double-network hydrogel-mediated synergistic PTT and CDT.

Multidrug-Resistant Bacterial Infections in Pediatric Patients Hospitalized at King Abdulaziz University Hospital, Jeddah, Western Saudi Arabia

Multidrug-resistant bacterial infections (MDRIs) constitute a major global threat due to increased patient morbidity/mortality and hospital stay/healthcare costs. A few studies from KSA, including our locality, addressed antimicrobial resistance in pediatric patients. This study was performed to recognize the incidence and clinical/microbiologic features of MDRIs in hospitalized pediatric patients. A retrospective cross-sectional study included pediatric patients < 18 years, admitted to King Abdulaziz University Hospital, between October 2021 and November 2022, with confirmed positive cultures of bacteria isolated from blood/body fluids. Patients' medical files provided the required data. MDR organisms (MDROs) were identified in 12.8% of the total cultures. The incidence of MDRIs was relatively high, as it was detected in 42% of patients and in 54.3% of positive bacterial cultures especially among critically ill patients admitted to the NICU and PICU. Pneumonia/ventilator-associated pneumonia was the main type of infection in 37.8% of patients with MDROs. Klebsiella pneumoniae was the most common significantly isolated MDRO in 39.5% of MDR cultures. Interestingly, a low weight for (no need for their as terminology weight for age is standard and well-known) was the only significant risk factor associated with MDROs (p = 0.02). Mortality was significantly higher (p = 0.001) in patients with MDROs (32.4%) than in patients without MDROs (3.9%). Patients who died including 85.7% of patients with MDROs had significantly longer durations of admission, more cultures, and utilized a larger number of antibiotics than the surviving patients (p = 0.02, p = 0.01, p = 0.04, respectively). This study provided a comprehensive update on the seriously alarming problem of MDROs, and its impacts on pediatric patients. The detected findings are crucial and are a helpful guide to decid for implementing effective strategies to mitigate MDROs.

Surveillance and Resistance of Community-Onset Extended-Spectrum β-Lactamase-Producing Escherichia coli and Klebsiella pneumonia in Oral and Maxillofacial Surgery Site Infections

Background: The prevalence of community-onset infections of extended spectrum β-lactamase (ESBL)-producing strains has increased globally, yet surveillance and resistance in patients with oral and maxillofacial surgery site infections is less investigated. Patients and Methods: A retrospective cohort study was performed to investigate risk factors and resistance of ESBL-producing Escherichia coli (ESBL-EC) and ESBL-producing Klebsiella pneumonia (ESBL-KP) among community-onset patients with oral and maxillofacial surgery during January 2010 to December 2016. Demographic features, predisposing factors, clinical outcomes, and antibiotic agent costs were analyzed. Antimicrobial susceptibility testing of nine antimicrobial agents against ESBL-KP and ESBL-EC were measured. Results: Among 2,183 cultures from infection sites in patients with oral and maxillofacial surgery site (45 cases [2.06%]) were confirmed with community-onset ESBL-KP (24; 1.10%) or ESBL-EC (21; 0.96%) infection. Multivariable analysis showed the independent risk factors for ESBL-producing bacterial infection were prior history of hospitalization (adjusted odds ratio [aOR], 10.984; 95% confidence interval [CI], 5.965-59.879; p = 0.025) and malignant condition (aOR, 3.373; 95% CI 2.947-7.634; p = 0.024). Based on antimicrobial susceptibility testing, 57.8% ESBL-KP and ESBL-EC were found receiving inappropriate antimicrobial therapy, and antibiotic agent costs were higher than non-ESBL-producing bacterial infections ($493.8 ± $367.3 vs. $304.1 ± $334.7; p = 0.031). Conclusions: Infections caused by ESBL-KP and ESBL-EC among patients in sites with oral and maxillofacial surgery are associated with prior history of hospitalization and malignant conditions. Prompt detection and appropriate antibiotic administration for community-onset infections of ESBLs are necessary for such populations.

[Precision medicine in infectious diseases]

Infectious medicine faces a variety of challenges, such as the increase in antibiotic resistance and the emergence and spread of infectious diseases fueled by climate change and globalization. Precision medicine can provide solutions to many of these challenges. Since an untargeted request for diagnostic tests can lead to test results without clinical relevance, which can increase the use of non-indicated antibiotics, the principle aimed at is: targeted diagnostics (the right test) and consideration of patient characteristics (the right person) to optimize management (the right action). At the same time, one must always decide whether empirical therapy must be immediately initiated, even if the results of the initiated diagnostics are not yet available. In addition, many new diagnostics as well as therapies have recently been developed for the rapid detection and more specific treatment of bacterial infections. Molecular genetic methods, which offer more rapid results than classical bacterial cultures, are gaining ground as new diagnostics. New therapeutics such as bacteriophages, antibodies or antibacterial peptides allow increasingly precise treatment of certain bacterial infections. Precision medicine will also play an increasingly important role in infectious medicine in the future.

Promising bioprocesses for the efficient removal of antibiotics and antibiotic-resistance genes from urban and hospital wastewaters: Potentialities of aerobic granular systems

The use, overuse, and improper use of antibiotics have resulted in higher levels of antibiotic-resistant bacteria (ARB) and antibiotic-resistance genes (ARGs), which have profoundly disturbed the equilibrium of the environment. Furthermore, once antibiotic agents are excreted in urine and feces, these substances often can reach wastewater treatment plants (WWTPs), in which improper treatments have been highlighted as the main reason for stronger dissemination of antibiotics, ARB, and ARGs to the receiving bodies. Hence, achieving better antibiotic removal capacities in WWTPs is proposed as an adequate approach to limit the spread of antibiotics, ARB, and ARGs into the environment. In this review, we highlight hospital wastewater (WW) as a critical hotspot for the dissemination of antibiotic resistance due to its high level of antibiotics and pathogens. Hence, monitoring the composition and structure of the bacterial communities related to hospital WW is a key factor in controlling the spread of ARGs. In addition, we discuss the advantages and drawbacks of the current biological WW treatments regarding the antibiotic-resistance phenomenon. Widely used conventional activated sludge technology has proved to be ineffective in mitigating the dissemination of ARB and ARGs to the environment. However, aerobic granular sludge (AGS) technology is a promising technology-with broad adaptability and excellent performance-that could successfully reduce antibiotics, ARB, and ARGs in the generated effluents. We also outline the main operational parameters involved in mitigating antibiotics, ARB, and ARGs in WWTPs. In this regard, WW operation under long hydraulic and solid retention times allows better removal of antibiotics, ARB, and ARGs independently of the WW technology employed. Finally, we address the current knowledge of the adsorption and degradation of antibiotics and their importance in removing ARB and ARGs. Notably, AGS can enhance the removal of antibiotics, ARB, and ARGs due to the complex microbial metabolism within the granular biomass.

Modified Gexia-Zhuyu Tang inhibits gastric cancer progression by restoring gut microbiota and regulating pyroptosis

BACKGROUND

Gexia-Zhuyu Tang (GZT), a traditional Chinese medicine formula, is used to treat a variety of diseases. However, its roles in gastric cancer (GC) remain unclear.

OBJECTIVE

The aim of this study was to explore the roles and underlying molecular mechanisms of modified GZT in GC.

METHODS

The effects of modified GZT on GC were investigated by constructing mouse xenograft models with MFC cell line. The fecal samples from low-dose, high-dose, and without modified GZT treatment groups were collected for the 16S rRNA gene sequencing and fecal microbiota transplantation (FMT). Histopathological alterations of mice were evaluated using the hematoxylin-eosin (HE). Immunohistochemical (IHC) analysis with Ki67 and GSDMD was performed to measure tissue cell proliferation and pyroptosis, respectively. Proteins associated with pyroptosis, invasion, and metastasis were detected by Western blotting. Enzyme-linked immunosorbent assay (ELISA) was used to assess inflammation-related factors levels.

RESULTS

Modified GZT inhibited GC tumor growth and reduced metastasis and invasion-related proteins expression levels, including CD147, VEGF, and MMP-9. Furthermore, it notably promoted caspase-1-dependent pyroptosis, as evidenced by a dose-dependent increase in TNF-α, IL-1β, IL-18, and LDH levels, along with elevated protein expression of NLRP3, ASC, and caspase-1. Additionally, modified GZT increased species abundance and diversity of the intestinal flora. FMT assay identified that modified GZT inhibited GC tumor progression through regulation of intestinal flora.

CONCLUSIONS

Modified GZT treatment may promote pyroptosis by modulating gut microbiota in GC. This study identifies a new potential approach for the GC clinical treatment.

Levothyroxine personalized treatment: is it still a dream?

Levothyroxine is a milestone in the treatment of all causes of hypothyroidism. From 19th century till today, Levothyroxine experienced a great advancement, from hypodermic injections of an extract of the thyroid gland of a sheep to novel formulations, known to circumvent malabsorption issue. However, the rate of patients on suboptimal therapy is still high. Current Guidelines are clear, daily Levothyroxine dosage should be calculated based on body weight. However, we are still far away from the possibility to administer the right dosage to the right patient, for several reasons. We retrace the history of treatment with levothyroxine, pointing out strengths and weaknesses of different formulations, with particular attention to what keeps us away from tailored therapy. In the age of digitalization, the pharmaceutical industry has been giving rising importance to Digital therapeutics, that are known to be effective in reaching target therapies. By combining current knowledge of hypothyroidism therapy with cutting-edge technology, we also hypothesized what could be the future strategies to be developed in this field.

Knowledge, attitudes, and practices regarding antibiotic use among the population of the Republic of Serbia - A cross-sectional study

BACKGROUND

Antimicrobial resistance presents one of the most significant threats to public health. This study aimed to examine antibiotic usage within the general population in the Republic of Serbia and their knowledge, attitudes, and behavior concerning this topic.

METHODS

We conducted an online cross-sectional study over two weeks in December 2022, on a sample of 1014 respondents, representative of the Republic of Serbia's population. Predictors of the Antibiotic Knowledge Score (composed of four questions) were analyzed by multivariate ordinal logistic regression.

RESULTS

In 2022, 76.8% of the participants from the Serbian population had taken antibiotics, mostly upon a medical prescription, with the most common reasons being upper respiratory tract infections. Only 31.3% of all respondents received any kind of advice about the rational use of antibiotics and half of them changed their opinions on using antibiotics after receiving this information. The average Antibiotic Knowledge Score was 2.6 out of 4, with 32.5% of respondents answering all knowledge questions correctly. The multivariate ordinal logistic regression analysis showed that female gender, higher education level, and the willingness to change opinions regarding the usage of antibiotics after receiving information about the rational use of antibiotics from any available source were significant predictors of better knowledge about antibiotics use. Respondents who were open to changing their opinion after receiving information about the rational use of antibiotics had 28% higher odds of higher antibiotic knowledge scores.

CONCLUSION

This is the first population-level study on public knowledge, attitudes, and practices about antibiotic use in Serbia and therefore the baseline for future research and measuring the impact of potential interventions. Our findings underline the importance of taking into account specific population characteristics, knowledge levels, and attitudes when designing educational and intervention strategies for antibiotic use. Policymakers can leverage these findings to target specific groups and enhance the population's knowledge and practices regarding rational antibiotic usage.

Antibiotic-induced collateral damage to the microbiota and associated infections

Antibiotics have transformed medicine, saving millions of lives since they were first used to treat a bacterial infection. However, antibiotics administered to target a specific pathogen can also cause collateral damage to the patient's resident microbial population. These drugs can suppress the growth of commensal species which provide protection against colonization by foreign pathogens, leading to an increased risk of subsequent infection. At the same time, a patient's microbiota can harbour potential pathogens and, hence, be a source of infection. Antibiotic-induced selection pressure can cause overgrowth of resistant pathogens pre-existing in the patient's microbiota, leading to hard-to-treat superinfections. In this Review, we explore our current understanding of how antibiotic therapy can facilitate subsequent infections due to both loss of colonization resistance and overgrowth of resistant microorganisms, and how these processes are often interlinked. We discuss both well-known and currently overlooked examples of antibiotic-associated infections at various body sites from various pathogens. Finally, we describe ongoing and new strategies to overcome the collateral damage caused by antibiotics and to limit the risk of antibiotic-associated infections.

Sensing of Antibiotic-Bacteria Interactions

Sensing of antibiotic-bacteria interactions is an important area of research that has gained significant attention in recent years. Antibiotic resistance is a major public health concern, and it is essential to develop new strategies for detecting and monitoring bacterial responses to antibiotics in order to maintain effective antibiotic development and antibacterial treatment. This review summarizes recent advances in sensing strategies for antibiotic-bacteria interactions, which are divided into two main parts: studies on the mechanism of action for sensitive bacteria and interrogation of the defense mechanisms for resistant ones. In conclusion, this review provides an overview of the present research landscape concerning antibiotic-bacteria interactions, emphasizing the potential for method adaptation and the integration of machine learning techniques in data analysis, which could potentially lead to a transformative impact on mechanistic studies within the field.

Daptomycin Pharmacokinetics in Blood and Wound Fluid in Critical Ill Patients with Left Ventricle Assist Devices

Daptomycin is a cyclic lipopeptide antibiotic with bactericidal effects against multidrug-resistant Gram-positive bacteria, including methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecalis (VRE). For critically ill patients, especially in the presence of implants, daptomycin is an important therapeutic option. Left ventricle assist devices (LVADs) can be utilized for intensive care patients with end-stage heart failure as a bridge to transplant. We conducted a single-center prospective trial with critically ill adults with LVAD who received prophylactic anti-infective therapy with daptomycin. Our study aimed to evaluate the pharmacokinetics of daptomycin in the blood serum and wound fluids after LVAD implantation. Daptomycin concentration were assessed over three days using high-performance liquid chromatography (HPLC). We detected a high correlation between blood serum and wound fluid daptomycin concentration at 12 h (IC95%: 0.64 to 0.95; r = 0.86; p < 0.001) and 24 h (IC95%: -0.38 to 0.92; r = 0.76; p < 0.001) after antibiotic administration. Our pilot clinical study provides new insights into the pharmacokinetics of daptomycin from the blood into wound fluids of critically ill patients with LVADs.

The synergistic activity of SBC3 in combination with Ebselen against Escherichia coli infection

Escherichia coli ranks as the number one clinical isolate in the past years in China according to The China Antimicrobial Surveillance Network (CHINET), and its multidrug-resistant (MDR) pathogenic strains account for over 160 million cases of dysentery and one million deaths per year. Here, our work demonstrates that E. coli is highly sensitive to the synergistic combination of SBC3 [1,3-Dibenzyl-4,5-diphenyl-imidazol-2-ylidene silver (I) acetate] and Ebselen, which shows no synergistic toxicity on mammalian cells. The proposed mechanism for the synergistic antibacterial effect of SBC3 in combination with Ebselen is based on directly inhibiting E. coli thioredoxin reductase and rapidly depleting glutathione, resulting in the increase of reactive oxygen species that cause bacterial cell death. Furthermore, the bactericidal efficacy of SBC3 in combination with Ebselen has been confirmed in mild and acute peritonitis mice. In addition, the five most difficult to treat Gram-negative bacteria (including E. coli, Acinetobacter baumannii, Enterobacter cloacae, Klebsiella pneumoniae, and Pseudomonas aeruginosa) are also highly sensitive to a synergistic combination of SBC3 and Ebselen. Thus, SBC3 in combination with Ebselen has potential as a treatment for clinically important Gram-negative bacterial infections.

Prevalence of biofilms in acute infections challenges a longstanding paradigm

The significance of bacterial biofilm formation in chronic bacterial lung infections has long been recognized [1]. Likewise, chronic biofilm formation on medical devices is well accepted as a nidus for recurrent bacteremia [2,3]. Even though the prevailing paradigm relies on the dominance of planktonic bacteria in acute endobronchial infections, our understanding of the bacterial organization during acute infection is, so far, limited - virtually absent. However, by comparing similar clinical samples, we have recently demonstrated massive bacterial biofilm formation during acute lung infections resembling the immense bacterial biofilm formation during chronic lung infections. These findings pose major challenges to the basic paradigm of chronic infections being dominated by biofilm forming bacteria while acute infections are dominated by planktonic bacteria. As opposed to the similar high amount of bacterial biofilm found in chronic and acute lung infections, we found that the fast bacterial growth in acute lung infections differed from the slow bacterial growth in chronic lung infections. By highlighting these new findings, we review modes of improved treatment of biofilm infections and the relevance of bacterial growth rates for other bacterial biofilm infections than human lung infections.

The potential of 4D's approach in curbing antimicrobial resistance among bacterial pathogens

INTRODUCTION

Antibiotics are life-saving drugs but irrational/inappropriate use leads to the emergence of antibiotic-resistant bacterial superbugs, making their treatment extremely challenging. Increasing antimicrobial resistance (AMR) among bacterial pathogens is becoming a serious public health concern globally. If ignorance persists, there would not be any antibiotics available to treat even a common bacterial infection in future.

AREA COVERED

This article intends to collate and discuss the potential of 4D's (right Drug, Dose, Duration, and De-escalation of therapy) approach to tackle the emerging problem of AMR. For this, we searched PubMed, Google Scholar, Medline, and clinicaltrials.gov databases primarily using keywords 'optimal antibiotic therapy,' 'antimicrobial resistance,' 'higher versus lower dose antibiotic treatment,' 'shorter versus longer duration antibiotic treatment,' 'de-escalation study', and 'antimicrobial stewardship measures' and based on the findings, form and expressed our opinion.

EXPERT OPINION

More efforts are needed for developing diagnostics for rapid, accurate, point-of-care, and cost-effective pathogen identification and antimicrobial susceptibility testing (AST) to facilitate rational use of antibiotics. Current dosing and duration of therapies also need to be redefined to maximize their impact. Furthermore, de-escalation approaches should be developed and encouraged in the clinic. This altogether will minimize selection pressure on the pathogens and reduce emergence of AMR.

Ellagic acid prevents gut damage via ameliorating microbe-associated intestinal lymphocyte imbalance

Inflammatory bowel disease (IBD) pathogenesis involves a sustained microbial-mediated immune response following intestinal stress. Although administration of antibiotics can be an effective therapy, the misuse of antibiotics may risk unknown drug-resistant bacteria. In this study, piglets pretreated with ellagic acid (EA) and Ampicillin (AMP) for 21 days, and were injected intraperitoneally with paraquat (PQ) on 14 and 18 days. We found piglets lost most of their gut microbes in the AMP group, protected from subsequent intestinal damage caused by gut oxidative stress. Hence, we identified some gut microbes that may play a critical role in mediating cellular responses following cytokine stimulation in PQ-induced stress. EA preprocessing exhibited the same performance as AMP. Pretreatment of EA reduced Streptococcus abundance in the gut. Particularly, EA modulated intestinal lymphocyte distribution, reduced the frequency of CD79a⁺ cells, and alleviated the upward migration of CD3⁺ cells to the apex of the intestinal villi in the intestinal epithelium. Additionally, the intestinal immune response had been known associated closely with the abundance of Streptococcus in the gut. Thus, we concluded that EA has the potential to replace antibiotics to prevent microbial-mediated immune responses in the gut, and EA can be applied as a supplement candidate to alleviate the development of inflammation caused by intestinal stress.

Dermatologic Disease-Directed Targeted Therapy (D3T2): The Application of Biomarker-Based Precision Medicine for the Personalized Treatment of Skin Conditions-Precision Dermatology

Precision dermatology uses individualized dermatologic disease-directed targeted therapy (D³T²) for the management of dermatoses and for the evaluation and therapy of cutaneous malignancies. Personalized/precision strategies are based on biomarkers that are most frequently derived from tissue transcriptomic expression or genomic sequencing or from circulating cytokines. For instance, the pathologic diagnosis of a pigmented lesion and determining the prognosis of a malignant melanocytic neoplasm can be enhanced by genomic/transcriptomic analysis. In addition to biopsy, innovative techniques have been developed for obtaining transcriptomes in skin conditions; as an example, patches can be applied to a psoriasis plaque for a few minutes to capture the epidermis/upper dermis transcriptome. Atopic dermatitis and prurigo nodularis may also be candidate conditions for precision dermatology. Precision dermatology has a role in managing melanoma and nonmelanoma skin cancers and rare cutaneous tumors-such as perivascular epithelioid cell tumor (PEComa)-that can originate in or metastasize to the skin. For instance, advanced/metastatic basal cell carcinomas can be treated with Hedgehog inhibitors (vismodegib and sonidegib) targeting the smoothened (SMO) or patched 1 (PTCH1) gene alterations that are a hallmark of these cancers and activate the Hedgehog pathway. Advanced/metastatic basal and cutaneous squamous cell cancers often have a high tumor mutational burden (which predicts immunotherapy response); immune checkpoint blockade with cemiplimab, a programmed cell death protein 1 (PD1) inhibitor, is now approved for these malignancies. Gene expression profiling of primary cutaneous squamous cell carcinoma can identify those individuals at high risk for subsequent metastases. In the realm of rare neoplasms, PEComas-which can originate in the skin, albeit uncommonly-have tuberous sclerosis complex 1 (TSC1)/tuberous sclerosis complex 2 (TSC2) gene alterations, which activate mammalian target of rapamycin (mTOR) signaling, and can be suppressed by nab-sirolimus, now approved for this condition. In summary, precision dermatologic techniques/strategies are an important emerging approach for evaluation and management of skin disorders and cutaneous neoplasms, and may serve as a paradigm for the application of precision medicine beyond dermatology.

The Response of the Rodent Gut Microbiome to Broad-Spectrum Antibiotics Is Different in Males and Females

Gut microbiome composition is different in males and females, but sex is rarely considered when prescribing antibiotics, and sex-based differences in gut microbiome recovery following antibiotic treatment are poorly understood. Here, we compared the effects of broad-spectrum antibiotics on both the stool and small bowel microbiomes in male and female rats. Adult male and female Sprague Dawley rats were exposed to a multi-drug antibiotic cocktail for 8 days, or remained unexposed as controls. Following cessation of antibiotics, rats were monitored for an additional 13-day recovery period prior to euthanasia. Baseline stool microbiome composition was similar in males and females. By antibiotic exposure day 8 (AbxD8), exposed male rats exhibited greater loss of stool microbial diversity compared to exposed females, and the relative abundance (RA) of numerous taxa were significantly different in exposed males vs. exposed females. Specifically, RA of phylum Proteobacteria and genera Lactobacillus, Sutterella, Akkermansia, and Serratia were higher in exposed males vs. exposed females, whereas RA of phyla Firmicutes and Actinobacteria and genera Turicibacter and Enterococcus were lower. By 13 days post antibiotics cessation (PAbxD13), the stool RA of these and other taxa remained significantly different from baseline, and also remained significantly different between exposed males and exposed females. RA of phyla Firmicutes and Actinobacteria and genus Enterococcus remained lower in exposed males vs. exposed females, and genus Sutterella remained higher. However, RA of phylum Proteobacteria and genus Akkermansia were now also lower in exposed males vs. females, whereas RA of phylum Bacteroidetes and genus Turicibacter were now higher in exposed males. Further, the small bowel microbiome of exposed rats on PAbxD13 was also significantly different from unexposed controls, with higher RA of Firmicutes, Turicibacter and Parabacteroides in exposed males vs. females, and lower RA of Bacteroidetes, Proteobacteria, Actinobacteria, Oscillospira, Sutterella, and Akkermansia in exposed males vs. females. These findings indicate that broad-spectrum antibiotics have significant and sex-specific effects on gut microbial populations in both stool and the small bowel, and that the recovery of gut microbial populations following exposure to broad-spectrum antibiotics also differs between sexes. These findings may have clinical implications for the way antibiotics are prescribed.

New methods for quantification of amoxicillin and clindamycin in human plasma using HPLC with UV detection

Objectives

We aimed to develop simple and rapid HPLC methods for determination of amoxicillin and clindamycin in human plasma.

Methods

Plasma samples were pretreated by direct deproteinization with acetonitrile and the analytical separation took place on a reverse phase Poroshell 120 EC-C18 column (2.7 μm, 2.1 × 100 mm) with a gradient of acetonitrile. UV detection at 229 nm for amoxicillin and 204 nm for clindamycin was used for determination of the antibiotics in plasma.

Results

The calibration curves were linear over the concentration ranges of 1–100 mg/L for amoxicillin and 1–15 mg/L for clindamycin with a correlation coefficient of ≥0.98. Intra-assay precisions were all ≤15% and the accuracies were within ±15%. The limit of quantification (LOQ) was found to be 0.5 mg/L for amoxicillin and 1 mg/L for clindamycin with inter-assay imprecision coefficient of variances (CVs) of 18.7% and 15.6%, respectively. The present HPLC methods were successfully applied on spike-in samples and on plasma samples collected 4–6 and 3.5–5.5 h after oral antibiotic administration of 500 mg of amoxicillin and 600 mg of clindamycin, respectively.

Conclusions

We have developed HPLC methods with UV detection for quantification of amoxicillin and clindamycin in human plasma. The methods are fast, simple and suitable for use in routine settings and clinical studies.

Inappropriate use of antibiotics and its predictors in pediatric patients admitted at the Central Hospital of Nampula, Mozambique

Background

Antibiotics are synthetic or natural substances used to treat bacterial infectious diseases. When used incorrectly, they can be a factor in the development of antimicrobial resistance, increased treatment time, costs, and mortality. The present study aimed to assess the pattern of inappropriate use of antibiotics and their predictors in pediatric patients admitted to the Central Hospital in Nampula, Mozambique.

Methods

A cross-sectional, retrospective study with a quantitative approach was conducted between January and July 2019. The population consisted of children ages 0–10 years hospitalized in the pediatric ward I. Binary logistic regression was used to determine risk factors for the inappropriate use of antibiotics with 95% confidence interval.

Results

The prevalence of antibiotic use among pediatric patients was 97.5%. Of the 464 antibiotics prescribed, 39.9% were for patients suffering from gastroenteritis, 21.8% and 9.1% for those affected with pneumonia and malaria, respectively. Most antibiotics were for parenteral use (95.9%, 445/464). Many (36.5%) of the prescriptions had errors, primarily in the duration of treatment (74.0%) or dosage (24.4%). Binary logistic regression analysis revealed that patients prescribed ≥ 3 antibiotics (OR = 2.83, 95% CI 1.245–6.462, p-value = 0.013) or hospitalized for a short time (OR = 1.88, 95% CI 1.133–2.3140, p-value = 0.015) were more likely to experience inappropriate use of antibiotics.

Conclusion

The study showed both a high prevalence of antibiotic use and a high error rate in prescriptions, especially among patients prescribed ≥ 3 antibiotics or hospitalized for a short time. These results are concerning, since inappropriate and excessive use of antibiotics is a major factor in the development of antibiotic-resistant microorganisms. Therefore, policies to reduce the inappropriate and excessive use of antibiotics are necessary.

A Polymer-Based Multichannel Sensor for Rapid Cell-Based Screening of Antibiotic Mechanisms and Resistance Development

Antibiotic resistance presents a critical threat to public health, necessitating the rapid development of novel antibiotics and an appropriate choice of therapeutics to combat refractory bacterial infections. Here, we report a high-throughput polymer-based sensor platform that rapidly (30 min) profiles mechanisms of antibiotic activity. The sensor array features three fluorophore-conjugated polymers that can detect subtle antibiotic-induced phenotypic changes on bacterial surfaces, generating distinct mechanism-based fluorescence patterns. Notably, discrimination of different generations of antibiotic resistance was achieved with high efficiency. This sensor platform combines trainability, simplicity, and rapid screening into a readily translatable platform.

Relationships Between Diagnosis, Bacterial Isolation, and Antibiotic Prescription in Out Patients With Respiratory Tract Infection Symptoms in Rural Anhui, China

Objectives

This paper aims to explore the direct associations of antibiotics prescription with clinical diagnosis and bacterial detection. It also analyses the relations of clinical diagnosis with symptoms and bacterial detection, with a hope of revealing indirect links to antibiotic prescription.

Methods

The study was implemented in one village clinic and one township health center in each of four rural residential areas in Anhui Province, China. Observations were conducted to record clinical diagnosis and antibiotic prescription. A semi-structured questionnaire survey was used to collected patients' sociodemographic information and reported symptoms. Sputum and throat swabs were collected for bacterial culture.

Results

Among 1,068 patients presenting in the study settings who received a diagnosis of respiratory tract infection (RTI), 87.8% of prescriptions included an antibiotic and 35.8% included two or more antibiotics. Symptomatic RTI patients to the site clinics were diagnosed mainly as having upper respiratory tract infection (32.0%), bronchitis/tracheitis (23.4%), others (16.6%), pharyngitis (11.1%), common cold (8.0%), pneumonia/bronchopneumonia (4.6%) and tonsillitis (4.3%). These clinical diagnosis were associated with symptoms to a varied degree especially for upper respiratory tract infection and bronchitis/tracheitis. Prescription of any antibiotics was positively associated with diagnosis of bronchitis/tracheitis (OR: 5.00, 95% CI: 2.63–9.51), tonsillitis (OR: 4.63, 95% CI: 1.48–14.46), pneumonia/bronchopneumonia (OR: 4.28, 95% CI: 1.40–13.04), pharyngitis (OR: 3.22, 95% CI: 1.57–6.59) and upper respiratory tract infection (OR: 3.04, 95% CI: 1.75–5.27). Prescription of two or more antibiotics was statistically significant related to diagnosis of bronchitis/ tracheitis (OR: 2.20, 95% CI: 1.44–3.35) or tonsillitis (OR: 2.97, 95% CI: 1.47–6.00). About 30% of the patients were identified with some type of bacteria. Bacteria detection was linked with pharyngitis (OR: 0.50, 95% CI: 0.28–0.88) but not prescription of antibiotics.

Conclusions

Antibiotics prescription were found with a strong relation to diagnosis of RTIs given by the clinician but was not associated with the presence of bacteria in patient samples. Part of the diagnosis may have been given by the clinician to justify their antibiotics prescription. There is clear need to use additional measures (e.g., symptoms) in conjunction with diagnosis to supervise or audit excessive antibiotics use.

Are Antibiotics Appropriately Dosed in Critically Ill Patients with Augmented Renal Clearance? A Narrative Review

AIMS

Augmented renal clearance (ARC), which is commonly defined as increased renal clearance above 130 ml/min/1.73 m², is a common phenomenon among critically ill patients. The increased elimination rate of drugs through the kidneys in patients with ARC can increase the risk of treatment failure due to the exposure to subtherapeutic serum concentrations of medications and affect the optimal management of infections, length of hospital stay, and outcomes. The main goal of this review article is to summarize the recommendations for appropriate dosing of antibiotics in patients with ARC.

METHODS

This article is a narrative review of the articles that evaluated different dosing regimens of antibiotics in patients with ARC. The keywords "Augmented Renal Clearance," "Critically ill patients," "Drug dosing," "Serum concentration," "Beta-lactams," "Meropenem," "Imipenem," "Glycopeptide," "Vancomycin," "Teicoplanin," "Linezolid," "Colistin," "Aminoglycosides," "Amikacin," "Gentamycin," "Fluoroquinolones," "Ciprofloxacin," and "Levofloxacin" were searched in Scopus, Medline, PubMed, and Google Scholar databases, and pediatric, nonhuman, and non-English studies were excluded.

RESULTS

PK properties of antibiotics including lipophilicity or hydrophilicity, protein binding, the volume of distribution, and elimination rate that affect drug concentration should be considered along with PD parameters for drug dosing in critically ill patients with ARC.

CONCLUSION

This review recommends a dosing protocol for some antibiotics to help the appropriate dosing of antibiotics in ARC and decrease the risk of subtherapeutic exposure that may be observed while receiving conventional dosing regimens in critically ill patients with ARC.

OUP accepted manuscript

Objectives

To describe the therapeutic drug monitoring (TDM) of cefepime in non-critically ill adults and compare four different ways of dosing: conventional table-based; empirically adjusted following TDM; individualized based on a population pharmacokinetic (PopPK) model without TDM; and TDM-adjusted with a Bayesian approach integrating TDM and PopPK.

Methods

We conducted a retrospective study in a tertiary centre to examine the current practice of TDM and to evaluate the potential for improvement by PopPK-based software individualization. The prediction of trough concentrations and the total daily doses (TDD) prescribed according to each approach were compared by calculating the mean logarithmic bias and the root mean squared error, complemented by linear regression and variance analysis.

Results

Among 168 trough concentrations in 119 patients (median: 12 mg/L), 38.6% of measurements exceeded 15 mg/L, the reported threshold for neurotoxicity. Nine patients developed neurotoxicity. The prediction performance of PopPK alone for trough concentrations was moderate, but clearly improved after integration of TDM. Accordingly, TDD were significantly lower for a priori PopPK-based dosage (mean: 2907 mg/24 h) compared with actual table-based dosage (4625 mg/24 h, P < 0.001). They were also lower for a posteriori dosage based on PopPK and TDM (3377 mg/24 h) compared with actual dosage after empirical TDM (4233 mg/24 h, P < 0.001), as model-based adjustment privileged more frequent administrations.

Conclusions

Our observations support routine TDM of cefepime to prevent overdosing and subsequent toxicity in the non-critically ill. Software-based individualization seems promising to optimize the benefits of TDM, but has little potential to replace it.

Cereus sinensis Polysaccharide Alleviates Antibiotic-Associated Diarrhea Based on Modulating the Gut Microbiota in C57BL/6 Mice

The present study investigated whether the purified polysaccharide from Cereus sinensis (CSP-1) had beneficial effects on mice with antibiotic-associated diarrhea (AAD). The effects of CSP-1 on gut microbiota were evaluated by 16S rRNA high-throughput sequencing. Results showed that CSP-1 increased the diversity and richness of gut microbiota. CSP-1 enriched Phasecolarctobacterium, Bifidobacterium and reduced the abundance of Parabacteroides, Sutterella, Coprobacillus to near normal levels, modifying the gut microbial community. Microbial metabolites were further analyzed by gas chromatography-mass spectrometry (GC-MS). Results indicated CSP-1 promoted the production of various short-chain fatty acids (SCFAs) and significantly improved intestinal microflora dysfunction in AAD mice. In addition, enzyme linked immunosorbent assay and hematoxylin-eosin staining were used to assess the effects of CSP-1 on cytokine levels and intestinal tissue in AAD mice. Results demonstrated that CSP-1 inhibited the secretion of interleukin-2 (IL-2), interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α) and improved the intestinal barrier. Correspondingly, the daily records also showed that CSP-1 promoted recovery of diarrhea status score, water intake and body weight in mice with AAD. In short, CSP-1 helped alleviate AAD by regulating the inflammatory cytokines, altering the composition and richness of intestinal flora, promoting the production of SCFAs, improving the intestinal barrier as well as reversing the dysregulated microbiota function.

Understanding the pharmacokinetics of antibiotics in pregnancy: Is there a role for therapeutic drug monitoring? A narrative review

PURPOSE

Antibiotics are commonly used during pregnancy. However, physiological changes during pregnancy can affect the pharmacokinetics of drugs, including antibiotics, used during this period. Pharmacokinetic evaluations have shed light on how antibiotics are affected during pregnancy and have influenced dosing recommendations in this context. Methods: A narrative review was conducted and included reports providing data reflecting drug distribution and exposure in the context of pregnancy. Results: Pharmacokinetic parameters of antibiotics in pregnancy and transplacental passage of antibiotics are comprehensively presented. Conclusion: Knowledge about the impact on pharmacokinetics and fetal exposure is especially helpful for complicated or severe infections, including intra-amniotic infection and sepsis in pregnancy, where both mother and fetus are at risk. Further studies are warranted to consolidate the role of therapeutic drug monitoring in complicated or severe infections in pregnant patients.

Harnessing the Potential of Multiomics Studies for Precision Medicine in Infectious Disease

The field of infectious diseases currently takes a reactive approach and treats infections as they present in patients. Although certain populations are known to be at greater risk of developing infection (eg, immunocompromised), we lack a systems approach to define the true risk of future infection for a patient. Guided by impressive gains in "omics" technologies, future strategies to infectious diseases should take a precision approach to infection through identification of patients at intermediate and high-risk of infection and deploy targeted preventative measures (ie, prophylaxis). The advances of high-throughput immune profiling by multiomics approaches (ie, transcriptomics, epigenomics, metabolomics, proteomics) hold the promise to identify patients at increased risk of infection and enable risk-stratifying approaches to be applied in the clinic. Integration of patient-specific data using machine learning improves the effectiveness of prediction, providing the necessary technologies needed to propel the field of infectious diseases medicine into the era of personalized medicine.

The Functional Significance of Hydrophobic Residue Distribution in Bacterial Beta-Barrel Transmembrane Proteins

β-barrel membrane proteins have several important biological functions, including transporting water and solutes across the membrane. They are active in the highly hydrophobic environment of the lipid membrane, as opposed to soluble proteins, which function in a more polar, aqueous environment. Globular soluble proteins typically have a hydrophobic core and a polar surface that interacts favorably with water. In the fuzzy oil drop (FOD) model, this distribution is represented by the 3D Gauss function (3DG). In contrast, membrane proteins expose hydrophobic residues on the surface, and, in the case of ion channels, the polar residues face inwards towards a central pore. The distribution of hydrophobic residues in membrane proteins can be characterized by means of 1–3DG, a complementary 3D Gauss function. Such an analysis was carried out on the transmembrane proteins of bacteria, which, despite the considerable similarities of their super-secondary structure (β-barrel), have highly differentiated properties in terms of stabilization based on hydrophobic interactions. The biological activity and substrate specificity of these proteins are determined by the distribution of the polar and nonpolar amino acids. The present analysis allowed us to compare the ways in which the different proteins interact with antibiotics and helped us understand their relative importance in the development of the resistance mechanism. We showed that beta barrel membrane proteins with a hydrophobic core interact less strongly with the molecules they transport.

Antibiotic therapy in sepsis: No next time for a second chance!

WHAT IS KNOWN AND OBJECTIVE

Sepsis is a life-threatening organ dysfunction associated with a high rate of morbidity and mortality. Appropriate antibiotic therapy remains the cornerstone of sepsis and septic shock management.

COMMENT

Although the early initiation of antimicrobial agents in the treatment of sepsis is widely acknowledged, the selection and adjustment to optimal dosage can be equally important. Since significant pathophysiological changes in the critically ill patients lead to altered pharmacokinetics of antibiotics, early consideration of pharmacokinetic/pharmacodynamic (PK/PD) properties is necessary for optimal antibiotic dosing in sepsis and should be integrated in practice.

WHAT IS NEW AND CONCLUSION

Where possible, an individualized antibiotic dosing approach through the application of therapeutic drug monitoring (TDM) service should replace the conventional dosing in critically ill patients with sepsis. Finally, antimicrobial stewardship can help improve clinical outcomes.

Phage Therapy: Towards a Successful Clinical Trial

While phage therapy carried out as compassionate use (experimental therapy) has recently flourished, providing numerous case reports of supposedly healed patients, clinical trials aiming to formally prove their value in accord with current regulatory requirements have failed. In light of the current issue of increasing antibiotic resistance, the need for a final say regarding the place of phage therapy in modern medicine is evident. We analyze the possible factors that may favor success or lead to the failure of phage therapy: quality of phage preparations, their titer and dosage, as well as external factors that could also contribute to the outcome of phage therapy. Hopefully, better control of these factors may eventually bring about long-awaited positive results.

Precision Medicine in the Diagnosis and Management of Orthopedic Biofilm Infections

Orthopedic biofilm infections are difficult to treat and require a multidisciplinary approach to diagnostics and management. Recent advances in the field include methods to disrupt biofilm, sequencing tools, and antibiotic susceptibility tests for bacteria residing in biofilm. The observation of interclonal differences in biofilm properties of the causative microorganisms, together with considerations of comorbidities and polypharmacy in a growing aging population, calls for a personalized approach to treat these infections. In this article, we highlight aspects of precision medicine that may open new perspectives in the diagnosis and management of orthopedic biofilm infections.

Effect of augmented renal clearance on the therapeutic drug monitoring of vancomycin in patients after neurosurgery

OBJECTIVE

To study the effect of augmented renal clearance (ARC) on vancomycin therapeutic drug monitoring in patients undergoing neurosurgery.

METHODS

A retrospective observational analysis was conducted in a neurosurgery department from January 2019 to June 2019. Patients undergoing vancomycin therapeutic drug monitoring were assigned to the normal renal function or ARC group. The baseline characteristics, vancomycin therapeutic drug monitoring data, and prognosis were compared and analyzed.

RESULTS

In total, 104 patients were enrolled, including 78 and 26 patients in the normal renal function and ARC groups, respectively. There were significant differences in age, weight, creatinine clearance, the vancomycin treatment duration, the total dose, the trough concentration, and the trough concentration achievement rate between the two groups. Prognosis did not differ between the two groups. The trough concentration achievement rate in the ARC group was only 19.23%.

CONCLUSION

For young, obese, or otherwise healthy patients undergoing neurosurgery, attention should be paid to the possibility of ARC and the need for individualized dose adjustment based on the results of therapeutic drug monitoring.

Challenges for Clinical Development of Vaccines for Prevention of Hospital-Acquired Bacterial Infections

Increasing antibiotic resistance in bacteria causing endogenous infections has entailed a need for innovative approaches to therapy and prophylaxis of these infections and raised a new interest in vaccines for prevention of colonization and infection by typically antibiotic resistant pathogens. Nevertheless, there has been a long history of failures in late stage clinical development of this type of vaccines, which remains not fully understood. This article provides an overview on present and past vaccine developments targeting nosocomial bacterial pathogens; it further highlights the specific challenges associated with demonstrating clinical efficacy of these vaccines and the facts to be considered in future study designs. Notably, these vaccines are mainly applied to subjects with preexistent immunity to the target pathogen, transient or chronic immunosuppression and ill-defined microbiome status. Unpredictable attack rates and changing epidemiology as well as highly variable genetic and immunological strain characteristics complicate the development. In views of the clinical need, re-thinking of the study designs and expectations seems warranted: first of all, vaccine development needs to be footed on a clear rationale for choosing the immunological mechanism of action and the optimal time point for vaccination, e.g., (1) prevention (or reduction) of colonization vs. prevention of infection and (2) boosting of a preexistent immune response vs. altering the quality of the immune response. Furthermore, there are different, probably redundant, immunological and microbiological defense mechanisms that provide protection from infection. Their interplay is not well-understood but as a consequence their effect might superimpose vaccine-mediated resolution of infection and lead to failure to demonstrate efficacy. This implies that improved characterization of patient subpopulations within the trial population should be obtained by pro- and retrospective analyses of trial data on subject level. Statistical and systems biology approaches could help to define immune and microbiological biomarkers that discern populations that benefit from vaccination from those where vaccines might not be effective.

Advances in Antimicrobial Microneedle Patches for Combating Infections

Skin infections caused by bacteria, viruses and fungi are difficult to treat by conventional topical administration because of poor drug penetration across the stratum corneum. This results in low bioavailability of drugs to the infection site, as well as the lack of prolonged release. Emerging antimicrobial transdermal and ocular microneedle patches have become promising medical devices for the delivery of various antibacterial, antifungal, and antiviral therapeutics. In the present review, skin anatomy and its barriers along with skin infection are discussed. Potential strategies for designing antimicrobial microneedles and their targeted therapy are outlined. Finally, biosensing microneedle patches associated with personalized drug therapy and selective toxicity toward specific microbial species are discussed.

Cathelicidin-DM is an Antimicrobial Peptide from Duttaphrynus melanostictus and Has Wound-Healing Therapeutic Potential

Antimicrobial peptides (AMPs) are a class of templates with application potential for drug development. Amphibians are important sources of AMPs. Duttaphrynus melanostictus is the main source of traditional Chinese medicine "Chansu", which has anti-infection effect while without a clear mechanism. This study aimed to find the cathelicidin peptide in D. melanostictus and then investigate the activity in vivo and in vitro, and an AMP-encoding gene (cathelicidin-DM, GenBank: KJ820824.1) was obtained from the constructed cDNA library of D. melanostictus. The MIC test and SYTOX Green uptake were used for the evaluation of the bactericidal capacity and mechanisms. The serum stability tests were used for the evaluation of the application potential. The skin wound infection model and in vivo imaging were used for in vitro application of possibility evaluation. The results showed that cathelicidin-DM was a 37 amino acid AMP with good bactericidal ability, which was similar to melittin: both can kill bacteria within 15 min. Moreover, cathelicidin-DM exhibits good therapeutic potential in the mouse wound infection model, and it can be enriched to the site of infection for treatment. Thus, cathelicidin-DM could be a new template for antimicrobial drug development given its good antibacterial activity in vivo and in vitro.

Evaluation of current dosing guidance for oral rifampicin treatment in adult patients with osteoarticular infections

For management of osteoarticular infections, rifampicin appears to be the key antibiotic. We aimed to evaluate the actual rifampicin dosing regimens using a population pharmacokinetic model of rifampicin in patients with osteoarticular infections. A Monte Carlo simulation study was performed to simulate steady-state plasma concentrations for 1000 randomly sampled subjects using a total daily dose between 600 and 1200 mg (600 and 900 mg once daily, 450 and 600 mg twice daily, or 300 mg 3 times daily). When rifampicin was administered with fusidic acid, the pharmacokinetic/pharmacodynamic (PK/PD) target (area under the curve/minimum inhibitory concentration ≥952) was achieved with all tested dosing regimen, except 600 mg once daily for Staphylococcus epidermidis infections. Without coadministration of fusidic acid, none of tested dosing regimens achieved this PK/PD target. Most recommended drug-dosing regimens allow attaining the fixed area under the curve/minimum inhibitory concentration target for Staphylococcus aureus and coagulase-negative staphylococcal osteoarticular infections. In future studies, PK/PD target for osteoarticular infections in human should also be confirmed.

Nine Things Genomics Can Tell Us About Candida auris

Candida auris is a recently emerged multidrug-resistant fungal pathogen causing severe illness in hospitalized patients. C. auris is most closely related to a few environmental or rarely observed but cosmopolitan Candida species. However, C. auris is unique in the concern it is generating among public health agencies for its rapid emergence, difficulty to treat, and the likelihood for further and more extensive outbreaks and spread. To date, five geographically distributed and genetically divergent lineages have been identified, none of which includes isolates that were collected prior to 1996. Indeed, C. auris' ecological niche(s) and emergence remain enigmatic, although a number of hypotheses have been proposed. Recent genomic and transcriptomic work has also identified a variety of gene and chromosomal features that may have conferred C. auris with several important clinical phenotypes including its drug-resistance and growth at high temperatures. In this review we discuss nine major lines of enquiry into C. auris that big-data technologies and analytical approaches are beginning to answer.