Guidelines for the prophylaxis and treatment of methicillin-resistant Staphylococcus aureus (MRSA) infections in the UK

Efficacy and safety of co-trimoxazole in device-related bone and joint infections: a CRIOGO multicentre case-control study

OBJECTIVES

Co-trimoxazole could be an alternative antibiotic to treat device-related bone and joint infection (BJI) but there are few published data about its efficacy and safety in this complex scenario to treat infection. The objective was to compare the outcome of patients with device-related BJI treated with an antibiotic regimen including co-trimoxazole versus a regimen without co-trimoxazole.

METHODS

This multicentre case-control study included consecutive adult patients diagnosed with device-related BJI. Each patient receiving co-trimoxazole was included in the co-trimoxazole group and was matched with two control patients, with stratification on microbial aetiology and age. The primary outcome was composite and defined by death or treatment failure during the follow-up.

RESULTS

In this study, 150 patients were included, 50 in the co-trimoxazole group and 100 in the control group. The rate of reaching the primary endpoint was 18% in the co-trimoxazole group (9/50 cases) versus 21% in the control group (21/100) (P = 0.66). Co-trimoxazole use was not associated with an unfavourable outcome in the multivariate analysis (adjusted OR 0.8, 95% CI 0.31-2.06, P = 0.64). Although no significant difference was observed in premature discontinuation of treatment due to an adverse event between both groups (14 versus 12%, P = 0.73), treatment-related adverse events were significantly more frequently reported in patients of the co-trimoxazole group than the control group [34% (17/50) versus 18% (18/100), P = 0.03].

CONCLUSIONS

Co-trimoxazole appears to be an effective alternative for the treatment of BJI, even when it occurs on a device, but the safety profile requires close monitoring of adverse effects.

Antimicrobial Evaluation of Two Polycyclic Polyprenylated Acylphloroglucinol Compounds: PPAP23 and PPAP53

Polycyclic polyprenylated acylphloroglucinols (PPAPs) comprise a large group of compounds of mostly plant origin. The best-known compound is hyperforin from St. John's wort with its antidepressant, antitumor and antimicrobial properties. The chemical synthesis of PPAP variants allows the generation of compounds with improved activity and compatibility. Here, we studied the antimicrobial activity of two synthetic PPAP-derivatives, the water-insoluble PPAP23 and the water-soluble sodium salt PPAP53. In vitro, both compounds exhibited good activity against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococcus faecium. Both compounds had no adverse effects on Galleria mellonella wax moth larvae. However, they were unable to protect the larvae from infection with S. aureus because components of the larval coelom neutralized the antimicrobial activity; a similar effect was also seen with serum albumin. In silico docking studies with PPAP53 revealed that it binds to the F1 pocket of human serum albumin with a binding energy of -7.5 kcal/mol. In an infection model of septic arthritis, PPAP23 decreased the formation of abscesses and S. aureus load in kidneys; in a mouse skin abscess model, topical treatment with PPAP53 reduced S. aureus counts. Both PPAPs were active against anaerobic Gram-positive gut bacteria such as neurotransmitter-producing Clostridium, Enterococcus or Ruminococcus species. Based on these results, we foresee possible applications in the decolonization of pathogens.

Effects of lung inflammation and injury on pulmonary tissue penetration of meropenem and vancomycin in a model of unilateral lung injury

OBJECTIVE

The timing and dosing of antimicrobial therapy are key in the treatment of pneumonia in critically ill patients. It is uncertain whether the presence of lung inflammation and injury affects tissue penetration of intravenously administered antimicrobial drugs. The effects of lung inflammation and injury on tissue penetration of two antimicrobial drugs commonly used for pneumonia were determined in an established model of unilateral lung injury.

METHODS

Unilateral lung injury was induced in the left lung of 13 healthy pigs through cyclic rinsing; the right healthy lung served as control. Infusions of meropenem and vancomycin were administered and concentrations of these drugs in lung tissue, blood, and epithelial lining fluid (ELF) were compared over a period of 6 h.

RESULTS

Median vancomycin lung tissue concentrations and penetration ratio were higher in inflamed and injured lungs compared with uninflamed and uninjured lungs (AUC0-6h: P = 0.003 and AUCdialysate/AUCplasma ratio: P = 0.003), resulting in higher AUC0-24/MIC. Median meropenem lung tissue concentrations and penetration ratio in inflamed and injured lungs did not differ from that in uninflamed and uninjured lungs (AUC0-6: P = 0.094 and AUCdialysate/AUCplasma ratio: P = 0.173). The penetration ratio for both vancomycin and meropenem into ELF was similar in injured and uninjured lungs.

CONCLUSION

Vancomycin penetration into lung tissue is enhanced by acute inflammation and injury, a phenomenon barely evident with meropenem. Therefore, inflammation in lung tissue influences the penetration into interstitial lung tissue, depending on the chosen antimicrobial drug. Measurement of ELF levels alone might not identify the impact of inflammation and injury.

Antimicrobial Treatment Challenges in the Management of Infective Spondylodiscitis Associated with Hemodialysis: A Comprehensive Review of Literature and Case Series Analysis

Infective spondylodiscitis (ISD), the infection of vertebral bodies and surrounding tissues, is a rare complication with major impact on the long-term survival of hemodialysis (HD) patients. Although the most frequent etiology is staphylococcal, identifying these pathogens in blood cultures and biopsy cultures is often difficult. This paper aims to present suitable antibiotic combinations for the treatment of these patients, which is usually challenging in the case of an unidentified pathogen. We presented the therapies applied for 13 HD patients and 19 patients without chronic kidney disease (CKD), diagnosed with ISD between 2013 and 2023 in Bihor County. The percentage of positive blood cultures was low in both groups (30.78% HD vs. 15.78% non-HD). The average length of antibiotic therapy was 5.15 weeks in HD patients and 6.29 weeks in non-HD patients. The use of Carbapenem alone (e.g., Meropenem) for an average of 19.6 days for patients in HD when the pathogen was not identified has proven to be efficient in most cases, similarly to using Vancomycin and Fluoroquinolone/Cephalosporines in combination. Regarding the non-CKD patients, the use of Clindamycin in various combinations for an average of 30.3 days has proven to be efficient in more than 90% of cases of ISD with a nonidentified pathogen. Within 2 years after ISD was diagnosed, 12 of the 13 HD patients passed away, mainly due to cardiovascular causes. Unfortunately, there are no guidelines in the literature concerning the empiric treatment of ISD in the particular case of HD patients. Upon checking the literature on PubMed and Google Scholar, only 10 studies provided relevant data regarding ISD treatment for HD patients. More data about the treatment and evolution of these patients is needed in order to elaborate a truly relevant metanalysis.

Population pharmacokinetics and model-based dosing optimization of teicoplanin in elderly critically ill patients with pneumonia

PURPOSE

To evaluate the population pharmacokinetics and pharmacodynamics of teicoplanin in elderly critically ill patients with pneumonia for optimal dosages.

METHODS

Fifteen critically ill patients (9 men) ≥ 60 years received teicoplanin 6 mg/kg for three doses followed by standard maintenance doses (6 mg/kg q24h) with renal dosing adjustment. Serial plasma samples from all patients were analyzed simultaneously by population pharmacokinetic modeling using NONMEM. Probability of target attainment (PTA) was calculated through Monte Carlo simulations for various dosing regimens to achieve adequate systemic exposures.

RESULTS

The median (interquartile range, IQR) age, body mass index, and creatinine clearance (CrCl) was 75 (64-78) years, 22.5 (20.8-25.4) kg/m2, and 64 (47-106) mL/min, respectively. The median (IQR) peak and trough concentration was 46.5 (42.7-51.0) and 8.7 (7.2-9.5) mg/L. The population pharmacokinetic model showed slower clearance (CL) and larger peripheral volume of distribution (V2) in patients with reduced CrCl: CL (L/h) = 0.629 × (CrCl/64)0.656, V2 (L) = 55.7 × (CrCl/64)-0.665. Model-based simulations showed PTAs ≥85% only for higher-dose regimens (12 mg/kg) up to an MIC of 0.5 mg/L.

CONCLUSIONS

Standard teicoplanin dosages for pneumonia may provide inadequate systemic exposures in elderly critically ill patients. High-dose regimens should be considered as empiric therapy or for less susceptible pathogens.

Efficient green silver nanoparticles-antibiotic combinations against antibiotic-resistant bacteria

Antibiotic-resistant bacterial strains and the consequent surge in infections caused by them have become major public health concerns. Silver nanoparticles (AgNPs) exhibit antibacterial properties and have wide applications in biomedical sciences. In this study, AgNPs were synthesized in the presence of antibiotics: Ceftazidime (Cft), Cefotaxime (Cef), Ceftriaxone (Cfx), and Cefepime (Cpm), along with the extract of Mentha longifolia. Mentha longifolia-based AgNPs were kept as the control for all experiments. The associated metabolites, structural properties, surface charges, and antibacterial activity of the AgNPs were also evaluated. Overall, a blue-shift of SPR peaks was observed for control AgNPs (λmax = 421 nm, 422 nm, 426 nm, and 406 nm for Cft-AgNPs, Cef-AgNPs, Cfx-AgNPs, and Cpm-AgNPs, respectively), compared to the control (λmax = 438 nm). Fourier-transform infrared spectroscopy showed that antibiotic-based AgNPs had distinct peaks that corresponded to the respective antibiotics, which were not observed in the control. XRD analysis showed that there were observed changes in crystallinity in antibiotic-based AgNPs compared to the control. TEM images revealed that all samples had spherical nanoparticles with different sizes and distributions compared to the control. The Zeta potential for extract-based AgNPs was - 33.6 mV, compared to -19.6 mV for Cft-AgNPs, -2 mV for Cef-AgNPs, -21.1 mV for Cfx-AgNPs, and - 24.2 mV for Cpm-AgNPs. The increase in the PDI value for antibiotic-based AgNPs also showed a highly polydisperse distribution. However, the antibiotic-AgNPs conjugates showed significantly higher activity against pathogenic bacteria. The addition of antibiotics to AgNPs brought significant changes in structural properties and antibacterial activities.

Albalawi S, M. Al-Zaydi K, Said MA. Synthesis of Silver(I) Complexes Containing 3-Oxo-3-phenyl-2-(2-phenylhydrazono)propanal-Based Ligands as a Multifunction Platform for Antimicrobial and Optoelectronic Applications

Toward multifunctionality, including antimicrobial and optoelectronic applications, herein, we reported the synthesis of a novel Ag(I) complex with 3-oxo-3-phenyl-2-(2-phenylhydrazono)propanal-based ligands including 3-(4-chlorophenyl)-2-[2-(4-nitrophenyl)hydrazono]-3-oxopropanal (named as "4A"), 3-(4-chlorophenyl)-2-[2-(4-methylphenyl)hydrazono]-3-oxopropanal (named as "6A"), and 3-(4-chlorophenyl)-3-oxo-2-(2-phenylhydrazono)propanal (named as "9A"). The synthesized compounds were characterized through FTIR, ¹H NMR, and density functional theory (DFT). The morphological features and thermal stability were evaluated through transmission electron microscopy (TEM) and TG/DTA analysis. The antimicrobial activity of the synthesized Ag complexes was tested against various pathogens, including Gram-negative bacteria (Escherichia coli and Klebsiella pneumonia), Gram-positive bacteria (Staphylococcus aureus and Streptococcus mutans), and fungi (Candida albicans and Aspergillus niger). Results show that the synthesized complexes (Ag(4A), Ag(6A), and Ag(9A)) possess promising antimicrobial efficacy against various pathogens and are in good competition with several standard drugs as well. On the other hand, the optoelectronic features such as absorbance, band gap, and Urbach energy were examined by measuring the absorbance using a UV-vis spectrophotometer. The values of the band gap reflected the semiconducting nature of these complexes. The complexation with Ag resulted in a lowering band gap to match the apex of the solar spectrum. Such low band gap values are preferable for optoelectronic applications like dye-sensitized solar cells, photodiodes, and photocatalysis.

The Identification and Treatment of Common Skin Infections

Skin conditions are a common problem addressed by medical providers. Up to 25% of individuals in the United States will seek attention for these conditions each year. The same problem occurs in the athletic training room, where athletes with infectious skin conditions can be seen. Most conditions are simple and can be treated without concern for spread to susceptible athletes. However, others can be quite serious and spread rapidly through a team and opponents during competition. Knowledge of the different types of skin infections is necessary to help treat these athletes and prevent spread to others. With proper diagnosis and treatment, certified athletic trainers can keep the athlete off the field of play for a minimum period and prevent transmission.

Pharmacist-Driven Dosing Services and Pharmaceutical Care Increase Probability of Teicoplanin Target Concentration Attainment and Improve Clinical and Economic Outcomes in Non-Critically Ill Patients

INTRODUCTION

Pharmacist-driven (PD) dosing and monitoring services have been shown to improve the clinical and economic outcomes in patients treated with different antibiotics, other than teicoplanin. This study investigates the impact of PD dosing and monitoring services on the clinical and economic outcomes of non-critically ill patients receiving teicoplanin treatment.

METHODS

A single-center retrospective study was conducted. Patients were divided into the PD group and the non-PD (NPD) group. Primary outcomes included the achievement of target serum concentration, and a composite endpoint of all-cause mortality, intensive care unit (ICU) admission, and sepsis or septic shock development during hospitalization or within 30 days of hospital admission. The cost of teicoplanin, overall medication cost, and total cost during hospital stay were also compared.

RESULTS

A total of 163 patients from January to December 2019 were included and assessed. Seventy patients were assigned to the PD group and 93 to the NPD group. The PD group had a higher percentage of patients reaching the target trough concentration (54% versus 16%, p < 0.001). Around 26% of the patients in the PD group and 50% of the patients in the NPD group met the composite endpoint during their hospital stay (p = 0.002). The PD group exhibited a significantly lower incidence of sepsis or septic shock, shorter hospital stays, reduced drug costs, and lower total expenses.

CONCLUSIONS

Our study demonstrates that pharmacist-driven teicoplanin therapy can improve the clinical and economic outcomes for non-critically ill patients.

TRIAL REGISTRATION

https://www.chictr.org.cn ; identifier, ChiCTR2000033521.

Randomized clinical trial: Long-term Staphylococcus aureus decolonization in patients on home parenteral nutrition

BACKGROUND & AIMS

Staphylococcus aureus decolonization has proven successful in prevention of S. aureus infections and is a key strategy to maintain venous access and avoid hospitalization in patients receiving home parenteral nutrition (HPN). We aimed to determine the most effective and safe long-term S. aureus decolonization regimen.

METHODS

A randomized, open-label, multicenter clinical trial was conducted. Adult intestinal failure patients with HPN support and carrying S. aureus were randomly assigned to a 'continuous suppression' (CS) strategy, a repeated chronic topical antibiotic treatment or a 'search and destroy' (SD) strategy, a short and systemic antibiotic treatment. Primary outcome was the proportion of patients in whom S. aureus was totally eradicated during a 1-year period. Secondary outcomes included risk factors for decolonization failure and S. aureus infections, antimicrobial resistance, adverse events, patient compliance and cost-effectivity.

RESULTS

63 participants were included (CS 31; SD 32). The mean 1-year S. aureus decolonization rate was 61% (95% CI 44, 75) for the CS group and 39% (95% CI 25, 56) for the SD group with an OR of 2.38 (95% CI 0.92, 6.11, P = 0.07). More adverse effects occurred in the SD group (P = 0.01). Predictors for eradication failure were a S. aureus positive caregiver and presence of a (gastro)enterostomy.

CONCLUSION

We did not demonstrate an increased efficacy of a short and systemic S. aureus decolonization strategy over a continuous topical suppression treatment. The latter may be the best option for HPN patients as it achieved a higher long-term decolonization rate and was well-tolerated (NCT03173053).

Model-informed precision dosing of teicoplanin for the rapid achievement of the target area under the concentration-time curve: A simulation study

Teicoplanin, a glycopeptide antimicrobial, is recommended for therapeutic drug monitoring, but it remains unclear how to target the area under the concentration-time curve (AUC). This simulation study purposed to demonstrate the potential of the Bayesian forecasting approach for the rapid achievement of the target AUC for teicoplanin. We generated concordant and discordant virtual populations against a Japanese population pharmacokinetic model. The predictive performance of the Bayesian posterior AUC in limited sampling on the first day against the reference AUC was evaluated as an acceptable target AUC ratio within the range of 0.8-1.2. In the concordant population, the probability for the maximum a priori or Bayesian posterior AUC on the first day (AUC_0-24 ) was 61.3% or more than 77.0%, respectively. The Bayesian posterior AUC on the second day (AUC_24-48 ) was more than 75.1%. In the discordant population, the probability for the maximum a priori or Bayesian posterior AUC_0-24 was 15.5% or 11.7-80.7%, respectively. The probability for the maximum a priori or Bayesian posterior AUC_24-48 was 23.4%, 30.2-82.1%. The AUC at steady-state (AUC_SS ) was correlated with trough concentration at steady-state, with a coefficient of determination of 0.930; the coefficients on days 7 and 4 were 0.442 and 0.125, respectively. In conclusion, this study demonstrated that early sampling could improve the probability of AUC_0-24 and AUC_24-48 but did not adequately predict AUC_SS . Further studies are necessary to apply early sampling-based model-informed precision dosing in the clinical settings.

Population pharmacokinetic analysis and dosing regimen optimization of teicoplanin in critically ill patients with sepsis

Objectives: Teicoplanin has been extensively used in the treatment for infections caused by gram-positive bacteria including methicillin-resistant Staphylococcus aureus (MRSA). However, current teicoplanin treatment is challenging due to relatively low and variable concentrations under standard dosage regimens. This study aimed to investigate the population pharmacokinetics (PPK) characteristics of teicoplanin in adult sepsis patients and provide recommendations for optimal teicoplanin dosing regimens. Methods: A total of 249 serum concentration samples from 59 septic patients were prospectively collected in the intensive care unit (ICU). Teicoplanin concentrations were detected, and patients' clinical data were recorded. PPK analysis was performed using a non-linear, mixed-effect modeling approach. Monte Carlo simulations were performed to evaluate currently recommended dosing and other dosage regimens. The optimal dosing regimens were defined and compared by different pharmacokinetic/pharmacodynamic parameters, including trough concentration (C_min), the ratio of 24-h area under the concentration-time curve to the minimum inhibitory concentration (AUC_0-24/MIC), as well as the probability of target attainment (PTA) and the cumulative fraction of response (CFR) against MRSA. Results: A two-compartment model adequately described the data. The final model parameter estimates for clearance, central compartment volume of distribution, intercompartmental clearance and peripheral compartment volume were 1.03 L/h, 20.1 L, 3.12 L/h and 101 L, respectively. Glomerular filtration rate (GFR) was the only covariate that significantly affected teicoplanin clearance. Model-based simulations revealed that 3 or 5 loading doses of 12/15 mg/kg every 12 h followed by a maintenance dose of 12/15 mg/kg every 24 h-72 h for patients with different renal functions were required to achieve a target C_min of 15 mg/L and a target AUC_0-24/MIC of 610. For MRSA infections, PTAs and CFRs were not satisfactory for simulated regimens. Prolonging the dosing interval may be easier to achieve the target AUC_0-24/MIC than reducing the unit dose for renal insufficient patients. Conclusion: A PPK model for teicoplanin in adult septic patients was successfully developed. Model-based simulations revealed that current standard doses may result in undertherapeutic C_min and AUC, and a single dose of at least 12 mg/kg may be needed. AUC_0-24/MIC should be preferred as the PK/PD indicator of teicoplanin, if AUC estimation is unavailable, in addition to routine detection of teicoplanin C_min on Day 4, follow-up therapeutic drug monitoring at steady-state is recommended.

A Middle East systematic review and meta-analysis of prevalence and antibiotic susceptibility pattern in MRSA Staphylococcus aureus isolated from patients with cystic fibrosis

Background

This study aimed to determine the prevalence and antibiotic resistance patterns in Staphylococcus aureus isolated from patients with cystic fibrosis in Middle Eastern countries.

Methods

A systematic search was conducted in the PubMed, Web of Science (ISI), and Scopus databases for studies presenting the prevalence of MRSA strains, antibiotic resistance pattern in S. aureus strains isolated from patients who suffered from cystic fibrosis in Middle Eastern countries from 1999 to 10 June 2020. The following terms were used; prevalence, antibiotic resistance, antimicrobial drug resistance, drug resistance, Staphylococcus aureus, S. aureus, Methicillin-resistant Staphylococcus aureus, MRSA, cystic fibrosis, CF, and the Middle East. The meta-analysis was performed using Comprehensive Meta-analysis software (Version 3.3.070).

Results

Patients’ age ranged from 1.6 to 18 years. Females were more than males. The prevalence of S. aureus was varied between 5.6 and 77.8%. The prevalence of S. aureus was varied between 5.6 and 77.8% in different countries. The combined prevalence of S. aureus in Middle East countries from 1999 to 2020 was reported by 40.9% (95% CI 29.6–53.1). The pooled prevalence of MRSA was reported at 18.6% (95% CI 1.1–82.6), Z = 0.9, I² = 98.6, Q = 146.7. The highest combined resistance in S. aureus strains was reported to Penicillin G (94%), followed by Ciprofloxacin (54.9%).

Conclusion

Regarding a quite prevalence of S. aureus and an intermediate prevalence of MRSA in CF patients, preventive measures and health policies should be implemented in the Middle East area to prevent the spread of infections caused by MRSA strains in CF patients.

Supplementary Information

The online version contains supplementary material available at 10.1186/s41043-022-00305-x.

Investigating forthcoming strategies to tackle deadly superbugs: current status and future vision

INTRODUCTION

Superbugs are microorganisms that cause disease and have increased resistance to the treatments typically used against infections. Recently, antibiotic resistance development has been more rapid than the pace at which antibiotics are manufactured, leading to refractory infections. Scientists are concerned that a particularly virulent and lethal 'superbug' will one day join the ranks of existing bacteria that cause incurable diseases, resulting in a global health disaster on the scale of the Black Death.

AREAS COVERED

This study highlights the current developments in the management of antibiotic-resistant bacteria and recommends strategies for further regulating antibiotic-resistant microorganisms associated with the healthcare system. This review also addresses the origins, prevalence, and pathogenicity of superbugs, and the design of antibacterial against these growing multidrug-resistant organisms from a medical perspective.

EXPERT OPINION

It is recommended that antimicrobial resistance should be addressed by limiting human-to-human transmission of resistant strains, lowering the use of broad-spectrum antibiotics, and developing novel antimicrobials. Using the risk-factor domains framework from this study would assure that not only clinical but also community and hospital-specific factors are covered, lowering the chance of confounders. Extensive subjective research is necessary to fully understand the underlying factors and uncover previously unexplored areas.

Antibiotics and Carbohydrate-Containing Drugs Targeting Bacterial Cell Envelopes: An Overview

Certain bacteria constitute a threat to humans due to their ability to escape host defenses as they easily develop drug resistance. Bacteria are classified into gram-positive and gram-negative according to the composition of the cell membrane structure. Gram-negative bacteria have an additional outer membrane (OM) that is not present in their gram-positive counterpart; the latter instead hold a thicker peptidoglycan (PG) layer. This review covers the main structural and functional properties of cell wall polysaccharides (CWPs) and PG. Drugs targeting CWPs are discussed, both noncarbohydrate-related (β-lactams, fosfomycin, and lipopeptides) and carbohydrate-related (glycopeptides and lipoglycopeptides). Bacterial resistance to these drugs continues to evolve, which calls for novel antibacterial approaches to be developed. The use of carbohydrate-based vaccines as a valid strategy to prevent bacterial infections is also addressed.

Target Therapeutic Ranges of Anti-MRSA Drugs, Linezolid, Tedizolid and Daptomycin, and the Necessity of TDM

The target therapeutic ranges of vancomycin, teicoplanin, and arbekacin have been determined, and therapeutic drug monitoring (TDM) is performed in clinical practice. However, TDM is not obligatory for daptomycin, linezolid, or tedizolid. In this study, we examined whether TDM will be necessary for these 3 drugs in the future. There was no significant difference in therapeutic effects on acute bacterial skin and skin structure infection between linezolid and tedizolid by meta-analysis. Concerning the therapeutic effects on pneumonia, the rate of effectiveness after treatment with tedizolid was significantly lower than with linezolid. With respect to safety, the incidences of gastrointestinal adverse events and blood/lymphatic system disorders related to tedizolid were significantly lower than those related to linezolid. Linezolid exhibits potent therapeutic effects on pneumonia, but the appearance of adverse reactions is indicated as a problem. There was a dose-dependent decrease in the platelet count, and the target trough concentration (C_trough) was estimated to be 4-6 or 2-7 µg/mL in accordance with the patient's condition. The efficacy of linezolid may be obtained while minimizing the appearance of adverse reactions by performing TDM. The target therapeutic range of tedizolid cannot be achieved in immunocompromised or severe patients. Therefore, we concluded that TDM was unnecessary, considering step-down therapy with oral drugs, use in non-severe patients, and high-level safety. Concerning daptomycin, high-dose administration is necessary to achieve an area under the curve (AUC) of ≥666 as an index of efficacy. To secure its safety, C_trough (<20 µg/mL) monitoring is important. Therefore, TDM is necessary.

Optimizing Antimicrobial Dosing for Critically Ill Patients with MRSA Infections: A New Paradigm for Improving Efficacy during Continuous Renal Replacement Therapy

The dosage regimen of vancomycin, teicoplanin and daptomycin remains controversial for critically ill patients undergoing continuous renal replacement therapy (CRRT). Monte Carlo simulation was applied to identify the optimal regimens of antimicrobial agents in patients with methicillin-resistant Staphylococcus aureus (MRSA) infections based on the mechanisms of different CRRT modalities on drug clearance. The optimal vancomycin dosage for patients received a CRRT doses ≤ 30 mL/kg/h was 20 mg/kg loading dose followed by 500 mg every 8 h, while 1 g every 12 h was appropriate when 35 mL/kg/h was prescribed. The optimal teicoplanin dosage under a CRRT dose ≤ 25 mL/kg/h was four loading doses of 10 mg/kg every 12 h followed by 10 mg/kg every 48 h, 8 mg/kg every 24 h and 6 mg/kg every 24 h for continuous veno-venous hemofiltration, continuous veno-venous hemodialysis and continuous veno-venous hemodiafiltration, respectively. When the CRRT dose increased to 30–35 mL/kg/h, the teicoplanin dosage should be increased by 30%. The recommended regimen for daptomycin was 6–8 mg/kg every 24 h under a CRRT dose ≤ 25 mL/kg/h, while 8–10 mg/kg every 24 h was optimal under 30–35 mg/kg/h. The CRRT dose has an impact on probability of target attainment and CRRT modality only influences teicoplanin.

Surgical Antimicrobial Prophylaxis in Patients of Neonatal and Pediatric Age Undergoing Orthopedic and Hand Surgery: A RAND/UCLA Appropriateness Method Consensus Study

Surgical site infections (SSIs) represent a potential complication in any type of surgery and can occur up to one year after the procedure in the case of implant placement. In the field of orthopedic and hand surgery, the rate of SSIs is a relevant issue, considering the need for the placement of synthesis devices and the type of some interventions (e.g., exposed fractures). This work aims to provide guidance on the management of peri-operative antibiotic prophylaxis for the pediatric and neonatal population undergoing orthopedic and hand surgery in order to standardize the management of patients and to reduce, on the one hand, the risk of SSI and, on the other, the development of antimicrobial resistance. The following scenarios were considered: (1) bloodless fracture reduction; (2) reduction of unexposed fracture and grade I and II exposed fracture; (3) reduction of grade III exposed fracture or traumatic amputation; (4) cruel fracture reduction with percutaneous synthesis; (5) non-traumatic amputation; (6) emergency intact skin trauma surgery and elective surgery without synthetic media placement; (7) elective orthopedic surgery with prosthetic and/or synthetic media placement and spinal surgery; (8) clean elective hand surgery with and without bone involvement, without use of synthetic means; (9) surgery of the hand on an elective basis with bone involvement and/or with use of synthetic means. This manuscript has been made possible by the multidisciplinary contribution of experts belonging to the most important Italian scientific societies and represents, in our opinion, the most complete and up-to-date collection of recommendations regarding the behavior to be adopted in the peri-operative setting in neonatal and pediatric orthopedic and hand surgery. The specific scenarios developed are aimed at guiding the healthcare professional in practice to ensure the better and standardized management of neonatal and pediatric patients, together with an easy consultation.

Clinical practice guidelines for therapeutic drug monitoring of teicoplanin: a consensus review by the Japanese Society of Chemotherapy and the Japanese Society of Therapeutic Drug Monitoring

Background

Owing to its low risk of adverse effects, teicoplanin has been extensively used in patients with infections caused by MRSA. To promote the better management of patients receiving teicoplanin, we have updated the guidelines for therapeutic drug monitoring (TDM).

Methods

The guidelines were developed by a committee following the methodology handbook published by the Japanese Medical Information Distribution Service. Nine clinical questions were selected. The committee conducted a systematic review and meta-analysis to establish evidence-based recommendations for the target trough concentration (C_min). An initial electronic database search returned 515 articles, and 97 articles qualified for a full review. Four and five studies were included for the efficacy evaluation of cut-off C_min values of 15 and 20 mg/L, respectively.

Results

Compared with C_min < 15 mg/L, a target C_min value of 15–30 mg/L resulted in increased clinical efficacy in patients with non-complicated MRSA infections (OR = 2.68; 95% CI = 1.14–6.32) without an increase in adverse effects. Although there was insufficient evidence, target C_min values of 20–40 mg/L were suggested in patients with complicated or serious MRSA infections. A 3 day loading regimen followed by maintenance treatment according to renal function was recommended to achieve the target trough concentrations. Because of the prolonged half-life of teicoplanin, measurement of the C_min value on Day 4 before reaching steady state was recommended.

Conclusions

The new guideline recommendations indicate the target C_min value for TDM and the dosage regimen to achieve this concentration and suggest practices for specific subpopulations.

Current Treatment Strategies Against Multidrug-Resistant Bacteria: A Review

There are several bacteria called superbugs that are resistant to multiple antibiotics which can be life threatening specially for critically ill and hospitalized patients. This article provides up-to-date treatment strategies employed against some major superbugs, like methicillin-resistant Staphylococcus aureus, carbapenem-resistant Enterobacteriaceae, vancomycin-resistant Enterococcus, multidrug-resistant Pseudomonas aeruginosa, and multidrug-resistant Escherichia coli. The pathogen-directed therapeutics decrease the toxicity of bacteria by altering their virulence factors by specific processes. On the other hand, the host-directed therapeutics limits these superbugs by modulating immune cells, enhancing host cell functions, and modifying disease pathology. Several new antibiotics against the global priority superbugs are coming to the market or are in the clinical development phase. Medicinal plants possessing potent secondary metabolites can play a key role in the treatment against these superbugs. Nanotechnology has also emerged as a promising option for combatting them. There is urgent need to continuously figure out the best possible treatment strategy against these superbugs as resistance can also be developed against the new and upcoming antibiotics in future. Rational use of antibiotics and maintenance of proper hygiene must be practiced among patients.

Risk factors of multidrug-resistant pyogenic spondylitis in thoraco-lumbar spine: A retrospective study of 122 cases

BACKGROUND

The number of spinal infections has been increasing in developed countries due to the increase of aged or immunosuppressed patients. Spondylitis caused by multidrug-resistant (MDR) bacterial infection often become intractable and require long-term antibiotic therapy and multiple surgeries. Therefore, it is of great importance to understand risk factors for MDR spinal infections. The aim of this study was to elucidate the risk factors for MDR bacterial spondylitis.

METHODS

A total of 122 patients (82 men, 40 women; average age: 63.8 y) with thoracic/lumbar spondylitis who underwent posterolateral full-endoscopic debridement and irrigation were included. The organisms detected by this endoscopic procedure were investigated, and the incidence and risk factors for MDR bacterial infection were retrospectively analyzed.

RESULTS

Cultures of specimens obtained by endoscopic procedures were positive in 78 patients (63.9%). Among 68 isolated bacteria, MDR bacteria accounted for 47.1%. Multivariate analysis showed that significant risk factors for MDR bacterial infection included autoimmune connective tissue disease (P = 0.03) and central venous catheter (P = 0.02). The incidence of MDR bacteria in patients who were administered a broad-spectrum antibiotic for more than 1 month preoperatively was 64.0%, which was significantly higher than in patients who were administered a broad-spectrum antibiotic for less than 1 month and patients who were administered a narrow-spectrum antibiotic (P < 0.01, P < 0.01, respectively).

CONCLUSIONS

The significant risk factors for MDR bacterial spondylitis included immunosuppressed conditions, such as autoimmune connective tissue disease, presence of central venous catheter, and longer administration periods of a broad-spectrum antibiotic. In patients with pyogenic spondylitis who could not be controlled with previous antibiotics and whose result of culture was negative, administration of anti-MRSA antibiotics would be considered when they have the risk factors identified in this study.

Staphylococcus aureus with inducible clindamycin resistance and methicillin resistance in a tertiary hospital in Nepal

Background

Staphylococcus aureus is a global public health issue in both community and hospital settings. Management of methicillin-resistant S. aureus (MRSA) infections are tough owing to its resistance to many antibiotics. Macrolide-lincosamide-streptogramin B (MLSB) antibiotics are commonly used for the management of MRSA. This study was aimed to determine the occurrence of inducible clindamycin- and methicillin-resistant S. aureus at a tertiary care hospital in Kathmandu, Nepal.

Methods

A total of 1027 clinical samples were processed following standard laboratory procedures and antibiotic susceptibility testing of S. aureus was performed by disc diffusion method. MRSA isolates were detected phenotypically using cefoxitin disc, and inducible clindamycin resistance was detected phenotypically using the D-zone test.

Results

Of 1027 samples, 321 (31.2%) were culture positive, of which 38 (11.8%) were S. aureus. All S. aureus isolates were susceptible to vancomycin, and 25 (67%) of S. aureus isolates were multidrug-resistant. Similarly, 15 (39.5%) of S. aureus were MRSA and 14 (36.5%) were inducible clindamycin-resistant phenotypes.

Conclusion

Inducible clindamycin and methicillin resistance were common in S. aureus. This emphasizes that the methicillin resistance test and the D-zone test should be incorporated into the routine antibiotic susceptibility testing in hospital settings.

Treatment of MRSA infections in India: Clinical insights from a Delphi analysis

PURPOSE

International and Indian guidelines for the management of patients with methicillin-resistant Staphylococcus aureus (MRSA) infections are available, but the local guidelines are not MRSA-specific. This study aimed to provide clinical insights for the treatment of MRSA infections in India.

METHODS

We used a three-step modified Delphi method to obtain insights. Ten experts comprising infectious disease specialists, microbiologists, pulmonologists, and critical care experts agreed to participate in the analysis. In round 1, a total of 161 statements were circulated to the panel and the experts were asked to 'agree' or 'disagree' by responding 'yes' or 'no' to each statement and provide comments. The same process was used for 73 statements in round 2. Direct interaction with the experts was carried out in round 3 wherein 35 statements were discussed. At least 80% of the experts had to agree for a statement to reach concordance.

RESULTS

Eighty-eight statements in round 1, thirty-eight statements in round 2, and eight statements in round 3 reached concordance and were accepted without modification. The final document comprised 152 statements on the management of various syndromes associated with MRSA such as skin and soft tissue infections, bacteremia and endocarditis, pneumonia, bone and joint infections, and central nervous system infections.

CONCLUSIONS

This analysis will assist clinicians in India to choose an appropriate course of action for MRSA infections.

Pathogens and Prognosis of Deep Neck Infection in End-Stage Renal Disease Patients

OBJECTIVES/HYPOTHESIS

To examine the pathogenic bacterial spectra and prognosis of deep neck infection (DNI) in end-stage renal disease (ESRD) patients.

STUDY DESIGN

Retrospective study.

METHODS

Patients diagnosed with DNI between 2004 and 2015 in Chang Gung Memorial Hospital were enrolled and divided into three groups, namely ESRD-DNI, chronic kidney disease (CKD)-DNI, and non-CKD-DNI. Differences in pathogenic bacteria, treatment, and prognosis were compared across the three groups.

RESULTS

The bacterial spectra differed among the three groups. The main three facultative anaerobic or aerobic bacteria causing ESRD-DNIs were methicillin-resistant Staphylococcus aureus (MRSA; 25.4%), methicillin-susceptible S. aureus (MSSA; 14.1%), and Klebsiella pneumoniae (KP; 12.7%). For CKD-DNIs, they were KP (23.5%), Viridans streptococci (VS; 23.5%), and MSSA (14.7%). For non-CKD-DNIs, they were VS (31.7%), KP (17.2%), and coagulase-negative staphylococci (8.0%). Compared with the other groups, the ESRD-DNI group had higher white blood cell and C-reactive protein levels, longer hospital stays, more frequent admissions to the intensive care unit, more mediastinal complications, and a significantly higher mortality rate.

CONCLUSIONS

The ESRD-DNI group exhibited more severe disease activity and higher mortality compared with those of the CKD-DNI and non-CKD-DNI groups. MRSA was the leading pathogen for patients with ESRD-DNI. Physicians must implement strategies for the early detection of MRSA to accurately prescribe antibiotics and prevent nosocomial transmission.

LEVEL OF EVIDENCE

4 Laryngoscope, 2021.

Mechanistic aspects of plant-based silver nanoparticles against multi-drug resistant bacteria

Resistance among pathogenic bacteria to the existing antibiotics is one of the most alarming problems of the modern world. Alongwith reducing the use of antibiotics, and antibiotic stewardship, an alternative to antibiotics is much needed in the current scenario to combact infectious diseases. One alternative is to produce nanomaterials, especially, silver nanoparticles (AgNPs) against antibiotic-resistant bacteria. AgNPs are the most vital and fascinating nanoparticles because of their unique structural and functional properties and application against pathogenic bacteria. However, the synthesis of AgNPs remains a problem because of the chemicals and energy requirements and the byproducts of the reactions. Concerns have been raised about using chemically and physically synthesized nanoparticles because of their potential risks to the human body, animals, and environment. Green synthesis of these nanoparticles is a better alternative to physical and chemical approaches. Plant-based synthesis in turn is a method which can provide AgNPs that are cost-effective and eco-friendly as well as biocompatible. The specific features of size, morphology and shape of plant-based AgNPs give them the potency to fight multi-drug resistant bacteria. A detailed look into mechanistic aspects of the action of AgNPs against resistant bacteria with a focus on characteristic properties of AgNPs is required. This review discusses in detail these aspects and the potential of plant-based AgNPs as a solution to antibiotic resistance.

Optimal trough concentration of teicoplanin for the treatment of methicillin-resistant Staphylococcus aureus infection: A systematic review and meta-analysis

WHAT IS KNOWN AND OBJECTIVE

It has been recommended that the trough concentration (C_min ) of teicoplanin should be maintained at ≥20 μg/ml for difficult-to-treat complicated infections caused by methicillin-resistant Staphylococcus aureus (MRSA). Conversely, C_min of teicoplanin of at least 10 μg/ml is required for non-complicated MRSA infections. Considering the low incidence of nephrotoxicity for teicoplanin, C_min  = 15-30 μg/ml has been suggested for most MRSA infections. Thus, we assessed the clinical efficacy and adverse effects of teicoplanin at this target C_min .

METHODS

We searched electronic databases (PubMed, Cochrane Central Register of Controlled Trials and Ichushi-Web) to identify eligible studies. Studies were included if they provided the incidence of treatment success, mortality in patients with MRSA infection, and/or hepatotoxicity and nephrotoxicity according to the C_min range.

RESULTS AND DISCUSSION

Four trials assessing clinical success (n = 299) and three studies assessing adverse effects (n = 546) were included. C_min  = 15-30 μg/ml significantly increased the probability of treatment success compared with C_min  < 15 μg/ml (odds ratio [OR] = 2.68, 95% confidence interval [CI] = 1.14-6.32, p = 0.02). The all-cause mortality rate did not differ between the groups (OR = 0.46, 95% CI = 0.13-1.61, p = 0.22). C_min  = 15-30 μg/ml did not increase the risks of nephrotoxicity (OR = 0.91, 95% CI = 0.49-1.69, p = 0.76) or hepatotoxicity (OR = 0.67, 95% CI = 0.18-2.44, p = 0.54).

WHAT IS NEW AND CONCLUSION

Teicoplanin therapy using a C_min target of 15-30 μg/ml is likely to be associated with better clinical responses than C_min  < 15 μg/ml without increasing the risk of adverse effects.

Comparison of trough concentration and area under the curve of vancomycin associated with the incidence of nephrotoxicity and predictors of a high trough level

PURPOSE

A high vancomycin trough concentration during therapy is associated with increased nephrotoxicity, and the recent guidelines for therapeutic monitoring of vancomycin recommend target of the ratio of area under the curve (AUC) to minimum inhibitory concentration. We aimed to determine vancomycin trough concentration and AUC that induce nephrotoxicity and evaluate predictive factors associated with a high serum vancomycin trough level according to the initial dosing strategy.

METHODS

We conducted a retrospective cohort study in patients administered intravenous vancomycin from June 2013 to February 2017. Totally, 346 patients were included.

RESULTS

38 experienced nephrotoxicity during therapy. The both trough level and AUC were significant risk factors for the occurrence of vancomycin induced-nephrotoxicity (p < 0.001, p = 0.001). The exposure-response analysis revealed that the trough level of 15 μg/mL was associated with 12.0% nephrotoxicity incidence and AUC of 600 was associated with 12.9% nephrotoxicity incidence. During the treatment, 90 patients had an initial trough concentration of ≥15 μg/mL, and 124 patients had AUC of ≥600 μg h/mL. The multiple logistic regression analysis revealed body weight (p = 0.001), serum creatinine level (p = 0.028), daily vancomycin dose (p = 0.001), and ICU (p = 0.015) were independent predictive factors for a high trough concentration. And same factors were selected for the high AUC.

CONCLUSION

The risk factors for vancomycin induced nephrotoxicity were comparable in both trough concentration and AUC. The incidence of nephrotoxicity can be reduced by controlling vancomycin trough concentration similarly AUC and promoting antimicrobial stewardship.

Impact of chemorophylaxis policy for AIDS-immunocompromised patients on emergence of bacterial resistance

Chemoprophylaxis (antibiotic prophylaxis) is a long relied-upon means of opportunistic infection management among HIV/AIDS patients, but its use represents an evolutionary tradeoff: Despite the benefits of chemoprophylaxis, widespread use of antibiotics creates a selective advantage for drug-resistant bacterial strains. Especially in the developing world, with combined resource limitations, antibiotic misuse, and often-poor infection control, the emergence of antibiotic resistance may pose a critical health risk. Extending previous work that demonstrated that this risk is heightened when a significant proportion of the population is HIV/AIDS-immunocompromised, we work to address the relationship between HIV/AIDS patients' use of antibiotic chemoprophylaxis and the emergence of resistance. We apply an SEIR compartmental model, parameterized to reflect varying percentages of chemoprophylaxis use among HIV/AIDS+ patients in a resource-limited setting, to investigate the magnitude of the risk of prophylaxis-associated emergence versus the individual-level benefits it is presumed to provide. The results from this model suggest that, while still providing tangible benefits to the individual, chemoprophylaxis is associated with negligible decreases in population-wide morbidity and mortality from bacterial infection, and may also fail to provide assumed efficacy in reduction of TB prevalence.

Antibiotic Resistance Profile and Methicillin-Resistant Encoding Genes of Staphylococcus aureus Strains Isolated from Bloodstream Infection Patients in Northern Vietnam

BACKGROUND:

Evaluating the antibiotic susceptibility and resistance genes is essential in the clinical management of bloodstream infections (BSIs). Nevertheless, there are still limited studies in Northern Vietnam. This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License (CC BY-NC 4.0)

AIM:

This study aimed to determine the antibiotic resistance profile and methicillin-resistant encoding genes of Staphylococcus aureus (S. aureus) causing BSIs in Northern Vietnam.

METHODS:

The cross-sectional study was done from December 2012 to June 2014 in two tertiary hospitals in Northern Vietnam. Tests performed at the lab of the hospital.

RESULTS:

In 43 S. aureus strains isolating, 53.5 % were MRSA. Distribution of gene for overall, MRSA, and MSSA strains were following mecA gene (58.1 %; 95.7%, and 15%), femA gene (48.8%, 47.8%, and 50%), femB gene (88.4%, 82.6%, and 95%). Antibiotic resistance was highest in penicillin (100%), followed by erythromycin (65.1%) and clindamycin (60.5%). Several antibiotics were susceptible (100%), including vancomycin, tigecycline, linezolid, quinupristin/dalfopristin. Quinolone group was highly sensitive, include ciprofloxacin (83.7%), levofloxacin (86%) and moxifloxacin (86%).

CONCLUSION:

In S. aureus causing BSIs, antibiotic resistance was higher in penicillin, erythromycin, and clindamycin. All strains were utterly susceptible to vancomycin, tigecycline, linezolid, quinupristin/dalfopristin.

Comparative Effectiveness of Local Application of Chlorhexidine Gluconate, Mupirocin Ointment, and Normal Saline for the Prevention of Peritoneal Dialysis-related Infections (COSMO-PD Trial): a multicenter randomized, double-blind, controlled protocol

BACKGROUND

Current international guidelines recommend the use of a daily topical exit-site antimicrobial to prevent peritoneal dialysis (PD)-related infections. Although nonantibiotic-based therapies are appealing because they may limit antimicrobial resistance, no controlled trials have been conducted to compare topical antimicrobial agents with usual exit-site care for the prevention of PD-related infections among the Thai PD population. We propose a controlled three-arm trial to examine the efficacy and safety of a daily chlorhexidine gluconate-impregnated patch versus mupirocin ointment versus usual exit-site care with normal saline for the prevention of PD-related infections.

METHODS/DESIGNS

This study is a randomized, double-blind, multicenter, active-controlled, clinical trial. Adult patients aged 18 years or older who have end-stage kidney disease and are undergoing PD will be enrolled at three PD Centers in Thailand. A total of 354 PD patients will be randomly assigned to either the 2% chlorhexidine gluconate-impregnated patch, mupirocin ointment, or usual exit-site care with normal saline dressing according to a computer-generated random allocation sequence. Participants will be followed until discontinuation of PD or completion of 24 months. The primary study outcomes are time to first PD-related infection (exit-site/tunnel infection or peritonitis) event and the overall difference in PD-related infection rates between study arms. Secondary study outcomes will include (i) the rate of infection-related catheter removal and PD technique failure, (ii) rate of nasal and exit-site Staphylococcus aureus colonization, (iii) healthcare costs, and (iv) skin reactions and adverse events. We plan to conduct a cost-utility analysis alongside the trial from the perspectives of patients and society. A Markov simulation model will be used to estimate the total cost and health outcome in terms of quality-adjusted life years (QALYs) over a 20-year time horizon. An incremental cost-effectiveness ratio in Thai Baht and U.S. dollars per QALYs gained will be illustrated. A series of probabilistic sensitivity analyses will be conducted to assess the robustness of the cost-utility analysis findings.

DISCUSSION

The results from this study will provide new clinical and cost-effectiveness evidence to support the best strategy for the prevention of PD-related infections among the Thai PD population.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT02547103. Registered on September 11, 2015.

Efficacy of cotrimoxazole (Sulfamethoxazole-Trimethoprim) as a salvage therapy for the treatment of bone and joint infections (BJIs)

INTRODUCTION

Cotrimoxazole (Sulfamethoxazole-Trimethoprim, SXT) has interesting characteristics for the treatment of bone and joint infection (BJI): a broad spectrum of activity with adequate bone diffusion and oral and intravenous formulations. However, its efficacy and safety in BJIs are poorly documented and its use remains limited.

METHODS

We conducted a retrospective study in 2 reference centers for BJIs from 2013 to 2018 among patients treated with SXT for a BJI. Data were collected from patient's medical charts. Outcomes and adverse events were evaluated at day (D)7, D45 and D90.

RESULTS

We analyzed 51 patients with a mean age of 60 ± 20 (SD) years of which 76% presented with an orthopedic device infection (ODI). Gram-negative bacilli (GNB) were involved in 47% of BJIs (n = 24). Moreover, they were often polymicrobial infections (41%). Doses of SXT ranged from 800/160mg bid (61%; n = 31) to 800/160mg tid (39%; n = 20). Median SXT treatment duration was 45 days (IQR 40-45). SXT was part of a dual therapy in 84% of patients (n = 43), associated mainly with fluoroquinolones (n = 17) or rifampicin (n = 14). Outcome was favorable at D7 in 98% (n = 50), at D45 in 88.2% (n = 45) and at D90 in 78.4% (n = 40). The second agent combined with SXT was not an independent factor of favorable outcome (p = 0.97). Adverse events were reported in 8% (n = 4) of patients, with a median of 21 days (IQR 20-30) from SXT initiation and led to discontinuation (n = 3).

CONCLUSION

SXT appears to be effective for treatment of BJIs as a salvage therapy, even in GNB or polymicrobial infection, including ODI. Further data are needed to confirm SXT efficacy as an alternative oral regimen in BJIs.

Use of antimicrobial dressings in England and the association with published clinical guidance: interrupted time series analysis

OBJECTIVES

In healthcare systems, practices and products of unproven value and cost-effectiveness can decrease value and increase waste. Using the management of complex wounds, this study investigates temporal trends in the use of antimicrobials dressings, places this in the context of available evidence and discusses the potential impacts on the UK National Health Service (NHS).

DESIGN

Secondary descriptive and interrupted time series (ITS) analysis of NHS prescription data.

SETTING

Prescribing Cost Analysis (PCA) details all NHS prescriptions dispensed in the community in England.

INTERVENTIONS

An ITS design was used to compare annual changes in the expenditure and use of antimicrobial and non-antimicrobial dressings before and after the publication of the 'intervention' of key evidence-based Scottish Intercollegiate Guidelines Network (SIGN) guidance in 2010.

PRIMARY AND SECONDARY OUTCOME MEASURES

Trends in use and expenditure of antimicrobial dressings in relation to published clinical guidance.

RESULTS

There was a large increase in the prescribing of, and expenditure on, antimicrobial wound dressings between 1997 and 2016. In 1997, the total number of dressings prescribed was 5 792 700; increasing to 11 447 102 in 2009 with expenditure increasing from £1 960 386 to £32 841 263. During the year of the SIGN intervention (2010), there was a significant drop in the use of silver but there was no consistent ongoing reduction from 2011 to 2015.

CONCLUSIONS

Prescribing data can be used to identify products of unproven benefit, which also impose a significant financial burden. This study quantifies the huge increase in the use of antimicrobial wound dressings over a 20-year period despite the lack of compelling evidence to support their routine use. There is some suggestion, however that the use and expenditure decreased after the publication of key guidance. Routine data can be used to as part of more systematic efforts to increase value and reduce waste in health systems.

Differences in distribution of MLS antibiotics resistance genes in clinical isolates of staphylococci belonging to species: S. epidermidis, S. hominis, S. haemolyticus, S. simulans and S. warneri

Background

Macrolides and lincosamides are two leading types of antibiotics commonly used in therapies. The study examines the differences in resistance to these antibiotics and their molecular bases in S. epidermidis as well as in rarely isolated species of coagulase-negative staphylococci such as S. hominis, S. haemolyticus, S. warneri and S. simulans. The isolates were tested for the presence of the erm(A), erm(B), erm(C), lnu(A), msr(A), msr(B), mph(C), ere(A) and ere(B) genes. Phenotypic resistance to methicillin and mecA presence were also determined.

Results

The MLS_B resistance mechanism was phenotypically found in isolates of species included in the study. The most prevalent MLS_B resistance mechanism was observed in S. hominis, S. haemolyticus and S. epidermidis isolates mainly of the MLS_B resistance constitutive type. Macrolide, lincosamide and streptogramin B resistance genes were rarely detected in isolates individually. The erm(B), ere(A) and ere(B) genes were not found in any of the strains. The erm(A) gene was determined only in four strains of S. epidermidis and S. hominis while lnu(A) was seen in eight strains (mainly in S. hominis). The erm(C) gene was present in most of S. epidermidis strains and predominant in S. hominis and S. simulans isolates. The examined species clearly differed between one another in the repertoire of accumulated genes.

Conclusions

The presence of genes encoding the MLS_B resistance among CoNS strains demonstrates these genes’ widespread prevalence and accumulation in opportunistic pathogens that might become gene reservoir for bacteria with superior pathogenic potential.

Evaluation of the antibacterial potential of silver nanoparticles synthesized through the interaction of antibiotic and aqueous callus extract of Fagonia indica

Fagonia indica is a widely known medicinal plant. The extracts of Fagonia species contain secondary metabolites such as flavonoids, phenolic compounds, and terpenoids. Silver nanoparticles are known for antibacterial properties. In this study, AgNPs were synthesized using the callus extract of F. indica as a reducing agent. Characterization through different techniques suggests that the AgNPs absorbed light and gave SPR peaks at 414 nm while in case of ciprofloxacin supplemented callus mediated AgNPs the peak were recorded at 419 nm. Furthermore, FTIR analysis revealed the role of amides, acyl group, nitro group of callus extract of F. indica, and some functional groups of the ciprofloxacin in the reduction process as well as the capping and stabilization of AgNPs. Similarly, X-Ray Diffraction analysis indicate the structure of AgNPs as face-centered cubic crystalline particles. The antibacterial activity of AgNPs and ciprofloxacin and callus extract as control against resistant bacteria such as Escherichia coli, Citrobacter amalonaticus, Shigella sonnei, and Salmonella typhi was studied. The combination of AgNPs and antibiotic showed better antibacterial activity as compared to AgNPs alone and ciprofloxacin alone. Maximum inhibition zone of E. coli, C. amalonaticus, S. sonnei, and S. typhi in response to AgNPs and ciprofloxacin was 38.5 mm, 35.5 mm, 33 mm, and 35.5 mm, respectively. It can, therefore, be suggested that the AgNPs along with Ciprofloxacin might have worked in interaction and resulted in better antibacterial activity against all the tested pathogens.

Adjunctive rifampicin to reduce early mortality from Staphylococcus aureus bacteraemia: the ARREST RCT

BACKGROUND

Staphylococcus aureus bacteraemia is a common and frequently fatal infection. Adjunctive rifampicin may enhance early S. aureus killing, sterilise infected foci and blood faster, and thereby reduce the risk of dissemination, metastatic infection and death.

OBJECTIVES

To determine whether or not adjunctive rifampicin reduces bacteriological (microbiologically confirmed) failure/recurrence or death through 12 weeks from randomisation. Secondary objectives included evaluating the impact of rifampicin on all-cause mortality, clinically defined failure/recurrence or death, toxicity, resistance emergence, and duration of bacteraemia; and assessing the cost-effectiveness of rifampicin.

DESIGN

Parallel-group, randomised (1 : 1), blinded, placebo-controlled multicentre trial.

SETTING

UK NHS trust hospitals.

PARTICIPANTS

Adult inpatients (≥ 18 years) with meticillin-resistant or susceptible S. aureus grown from one or more blood cultures, who had received < 96 hours of antibiotic therapy for the current infection, and without contraindications to rifampicin.

INTERVENTIONS

Adjunctive rifampicin (600-900 mg/day, oral or intravenous) or placebo for 14 days in addition to standard antibiotic therapy. Investigators and patients were blinded to trial treatment. Follow-up was for 12 weeks (assessments at 3, 7, 10 and 14 days, weekly until discharge and final assessment at 12 weeks post randomisation).

MAIN OUTCOME MEASURES

The primary outcome was all-cause bacteriological (microbiologically confirmed) failure/recurrence or death through 12 weeks from randomisation.

RESULTS

Between December 2012 and October 2016, 758 eligible participants from 29 UK hospitals were randomised: 370 to rifampicin and 388 to placebo. The median age was 65 years [interquartile range (IQR) 50-76 years]. A total of 485 (64.0%) infections were community acquired and 132 (17.4%) were nosocomial; 47 (6.2%) were caused by meticillin-resistant S. aureus. A total of 301 (39.7%) participants had an initial deep infection focus. Standard antibiotics were given for a median of 29 days (IQR 18-45 days) and 619 (81.7%) participants received flucloxacillin. By 12 weeks, 62 out of 370 (16.8%) patients taking rifampicin versus 71 out of 388 (18.3%) participants taking the placebo experienced bacteriological (microbiologically confirmed) failure/recurrence or died [absolute risk difference -1.4%, 95% confidence interval (CI) -7.0% to 4.3%; hazard ratio 0.96, 95% CI 0.68 to 1.35; p = 0.81]. There were 4 (1.1%) and 5 (1.3%) bacteriological failures (p = 0.82) in the rifampicin and placebo groups, respectively. There were 3 (0.8%) versus 16 (4.1%) bacteriological recurrences (p = 0.01), and 55 (14.9%) versus 50 (12.9%) deaths without bacteriological failure/recurrence (p = 0.30) in the rifampicin and placebo groups, respectively. Over 12 weeks, there was no evidence of differences in clinically defined failure/recurrence/death (p = 0.84), all-cause mortality (p = 0.60), serious (p = 0.17) or grade 3/4 (p = 0.36) adverse events (AEs). However, 63 (17.0%) participants in the rifampicin group versus 39 (10.1%) participants in the placebo group experienced antibiotic or trial drug-modifying AEs (p = 0.004), and 24 (6.5%) participants in the rifampicin group versus 6 (1.5%) participants in the placebo group experienced drug-interactions (p = 0.0005). Evaluation of the costs and health-related quality-of-life impacts revealed that an episode of S. aureus bacteraemia costs an average of £12,197 over 12 weeks. Rifampicin was estimated to save 10% of episode costs (p = 0.14). After adjustment, the effect of rifampicin on total quality-adjusted life-years (QALYs) was positive (0.004 QALYs), but not statistically significant (standard error 0.004 QALYs).

CONCLUSIONS

Adjunctive rifampicin provided no overall benefit over standard antibiotic therapy in adults with S. aureus bacteraemia.

FUTURE WORK

Given the substantial mortality, other antibiotic combinations or improved source management should be investigated.

TRIAL REGISTRATIONS

Current Controlled Trials ISRCTN37666216, EudraCT 2012-000344-10 and Clinical Trials Authorisation 00316/0243/001.

FUNDING

This project was funded by the National Institute for Health Research (NIHR) Health Technology Assessment programme and will be published in full in Health Technology Assessment; Vol. 22, No. 59. See the NIHR Journals Library website for further project information.

High variability of teicoplanin concentration in patients with continuous venovenous hemodiafiltration

INTRODUCTION

Continuous venovenous hemodiafiltration (CVVHDF) may alter teicoplanin pharmacokinetics and increase the risk of incorrect dosing. The objective of this prospective observational study was to assess the effect of CVVHDF on the pharmacokinetics of teicoplanin as maintenance therapy.

METHODS

Blood, urine, and dialysate samples were collected to measure teicoplanin levels. CVVHDF clearance (CL_CVVHDF ), total clearance (CL_TOTAL ), and volume of distribution (Vd) were calculated by simplex-linear modeling. The influence of CVVHDF dose on teicoplanin pharmacokinetics was assessed.

FINDINGS

Ten samples from eight patients were studied. Creatinine clearance was 3.4 ± 5.1 ml/min/1.73 m² . Three patients were anuria. The dose for CVVHDF was 32.1 ± 7.0 mL/kg/h. Vd was 1.6 ± 0.7 L/kg. T1/2 was 100.1 ± 42.7 hours. CL_TOTAL of teicoplanin was 11.9 ± 5.4 mL/min and CL_CVVHDF was 5.8 ± 4.2 mL/min. Contribution of CL_CVVHDF to CL_TOTAL was 51.2% ± 23.6%. CL_CVVHDF of individual teicoplanin varied widely. Large intra-occasion differences were also observed. Dose of CL_CVVHDF did not influence overall CL_TOTAL , Vd, or half-life. The proportion of CL_TOTAL due to CL_CVVHDF varied widely. It was high in some cases.

DISCUSSION

In patients receiving CVVHDF, there is great variability in teicoplanin pharmacokinetics which complicates empiric approach to dosing, suggesting the need for therapeutic drug monitoring.

Adhesion and biofilm formation by Staphylococcus aureus clinical isolates under conditions relevant to the host: relationship with macrolide resistance and clonal lineages

PURPOSE

Staphylococcus aureus isolates, collected from various clinical samples, were analysed to evaluate the contribution of the genetic background of both erythromycin-resistant (ERSA) and -susceptible (ESSA) S. aureus strains to biofilm formation.

METHODS

A total of 66 ESSA and 43 ERSA clinical isolates were studied for adhesiveness and biofilm formation under different atmospheres. All isolates were evaluated for phenotypic and genotypic macrolide resistance, and for clonal relatedness by pulsed-field gel electrophoresis (PFGE), and by spa typing on representative isolates.

RESULTS

A high genetic heterogeneity was encountered, although 10 major PFGE types accounted for 86 % with a few small spatially and temporally related clusters. Overall, biofilm formation under anoxia was significantly lower than under oxic and micro-aerophilic atmospheres. Biofilm formation by ESSA was significantly higher compared to ERSA under oxic and micro-aerophilic conditions. Adhesiveness to plastic was significantly higher among respiratory tract infection isolates under micro-aerophilic conditions, while surgical site infection isolates formed significantly higher biomass of biofilm under oxic and micro-aerophilic atmospheres compared to anoxia. Pulsotype 2 and 4 strains formed significantly higher biofilm biomass than pulsotype 1, with strains belonging to CC8 forming significantly more compared to those belonging to CC5, under both oxic and micro-aerophilic atmospheres.

CONCLUSIONS

S. aureus biofilm formation appears to be more efficient in ESSA than ERSA, associated with specific S. aureus lineages, mainly CC8 and CC15, and affected by atmosphere. Further studies investigating the relationship between antibiotic resistance and biofilm formation could prove useful in the development of new strategies for the management of S. aureus infections.

Efficacy of cloxacillin versus cefazolin for methicillin-susceptible Staphylococcus aureus bacteraemia (CloCeBa): study protocol for a randomised, controlled, non-inferiority trial

INTRODUCTION

Methicillin-susceptible Staphylococcus aureus (MSSA) bacteraemia is a common and severe disease responsible for approximately 65 000 deaths every year in Europe. Intravenous antistaphylococcal penicillins (ASP) such as cloxacillin are the current recommended antibiotics. However, increasing reports of toxicity and recurrent stock-outs of ASP prompted healthcare providers to seek for alternative antibiotic treatment. Based on retrospective studies, cefazolin, a first-generation cephalosporin, is recommended in patients at risk of severe ASP-associated toxicity.We hypothesised that cefazolin has a non-inferior efficacy in comparison to cloxacillin, with a better safety profile for the treatment of MSSA bacteraemia.

METHODS AND ANALYSIS

The CloCeBa trial is an open-label, randomised, controlled, non-inferiority trial conducted in academic centres throughout France. Eligible patients are adults with MSSA bacteraemia without intravascular device or suspicion of central nervous system infection. Patients will be randomised (1:1) to receive either cloxacillin or cefazolin by the intravenous route, for the first 14 days of therapy. The evaluation criteria is a composite criteria of negative blood cultures at day 5, survival, absence of relapse and clinical success at day 90 after randomisation. Secondary evaluation criteria include both efficacy and safety assessments. Three ancillary studies are planned to describe the epidemiology of β-lactamase encoding genes, the ecological impact and pharmacokinetic/pharmacodynamic parameters of cefazolin and cloxacillin. Including 300 patients will provide 80% power to demonstrate the non-inferiority of cefazolin over cloxacillin, assuming 85% success rate with cloxacillin and taking into account loss-to-follow-up, with a 0.12 non-inferiority margin and a one-sided type I error of 0.025.

ETHICS AND DISSEMINATION

This protocol received authorisation from the ethics committee Sud-Est I on 13 November 2017 (2017-87-PP)and French National Agency for Medicines and Health Products (170661A-43). Results will be disseminated to the scientific community through congresses and publication in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

NCT03248063 and 2017-003967-36.

Infectious Disease in Contact Sports

CONTEXT:

Infections are common in contact sports. This review aims to describe the epidemiology, presenting signs and symptoms, treatment guidelines, and regulations for several common infections seen in contact sport athletes. The conditions discussed include bacterial skin infections, herpes simplex virus, molluscum contagiosum, common warts, tinea, scabies, head lice, conjunctivitis, human immunodeficiency virus, hepatitis C virus, and vaccine-preventable illnesses.

EVIDENCE ACQUISITION:

Searches were performed across PubMed and MEDLINE research databases. In addition, general internet search engine results and reviews of reference lists of relevant papers were used to identify additional sources of evidence.

STUDY DESIGN:

Clinical review.

LEVEL OF EVIDENCE:

Level 4.

RESULTS:

The most common infections seen in contact sport athletes include bacterial skin infections, herpes simplex virus, molluscum contagiosum, common warts, tinea, scabies, head lice, conjunctivitis, and vaccine-preventable illnesses. Other infections, including human immunodeficiency virus and hepatitis C, are uncommon but potentially life threatening.

CONCLUSION:

Infections are common in contact sport athletes. The provider who cares for these athletes should be aware of the most common infections and their appropriate management. Early diagnosis and appropriate clinical management are important for treating the infected athlete, minimizing risk of transmission, minimizing time lost from competition, and preventing large outbreaks.

Clinical outcomes after initial treatment of methicillin-resistant Staphylococcus aureus infections

Objective

To evaluate the clinical outcomes associated with anti-methicillin-resistant Staphylococcus aureus (MRSA) antimicrobials.

Methods

We reviewed a prospective database of 247 consecutive patients with clinically and microbiologically confirmed MRSA infections, hospitalized in 7 Japanese hospitals between April 2014 and March 2015, and treated with anti-MRSA pharmaceuticals. Survival was measured at 30 days. We examined the relationships between initial antimicrobial administered and survival and organ toxicity. HR and 95% CIs were calculated.

Results

Overall 30-day mortality was 12%. The lungs were infected in 105 (41%), skin and soft tissue in 73 (30%), and bones and joints in 21 (9%) patients. Bacteremia complicated the illness in 69 patients (28%). Among 5 pharmaceuticals, vancomycin was prescribed to 174 (71%), linezolid to 38 (16%), teicoplanin to 22 (9%), and daptomycin to 11 (5%) patients. Vancomycin tended to be associated with the lowest survival (HR=2.47; 95% CI=0.93-6.51; P=0.067), particularly in the lung-infected subgroup (HR=4.85; 95% CI=1.12-20.94; P=0.034) after adjustments for baseline illness severity. The incidence of renal dysfunction tended to be higher in patients with trough serum concentrations of vancomycin >15 mg/dL.

Conclusion

In this observational study reflecting real-world conditions, vancomycin was associated with higher 30-day mortality and incidence of kidney dysfunction than other anti-MRSA agents. The significance of the differences observed among antimicrobials other than vancomycin is uncertain.

Evaluation of vancomycin MIC creep in Staphylococcus aureus

OBJECTIVES

Vancomycin is the primary treatment for methicillin-resistant Staphylococcus aureus (MRSA). However, an increasing proportion of MRSA isolates with high minimum inhibitory concentrations (MICs) within the susceptible range (vancomycin 'MIC creep') is being observed. The aim of this study was to assess the vancomycin MIC distribution for S. aureus isolates over a period of 4 years in Centro Hospitalar Baixo Vouga (Aveiro, Portugal) and to identify differences in vancomycin MIC determined by different susceptibility testing methods.

METHODS

For each S. aureus isolate, the vancomycin MIC was assayed by the VITEK^®2 automated system and the broth microdilution testing method.

RESULTS

The results showed significant differences in vancomycin MIC by different methods (P=0.021, sign test) and did not suggest the presence of vancomycin MIC creep during the study period.

CONCLUSIONS

Vancomycin MIC creep is a regional problem, therefore it can only be assessed through the evaluation of local susceptibility profiles, and antibiogram based on real MIC assay should be an essential element in local MRSA infection clinical management.

[Antibiotic stewardship and Staphylococcus aureus Bacteremia]

Rates of antibiotic resistance are increasing worldwide and impact on the treatment of patients with bacterial infections. A broad and uncritical application in inpatient and outpatient settings as well as in agriculture has been recognized as the main driving force. Antibiotic stewardship (ABS) programs aim at countering this worrisome development using various direct interventions such as infectious disease counseling. Blood stream infections caused by Staphylococcus (S.) aureus are severe infections associated with high mortality rates. ABS interventions such as de-eskalation of the antibiotic regimen or application of narrow-spectrum beta-lactam antibiotics can significantly reduce mortality rates. In this review, we discuss the importance of ABS programs and infectious disease counseling for the treatment of S. aureus blood stream infection.

Evaluation of Teicoplanin Trough Values After the Recommended Loading Dose in Children With Associated Safety Analysis

BACKGROUND

This study evaluated whether the recommended teicoplanin loading dose (3 loading doses of 10 mg/kg every 12 hours) achieves a 15-30 μg/mL trough levels in 26 children (2-16 years). In addition, we examined the incidences of renal impairment and hepatic dysfunction in children treated with teicoplanin.

METHODS

This retrospective study was conducted between October 2008 and March 2014.

RESULTS

The percentage of patients with a trough level <10 and <15 μg/mL were 15.4% (4/26) and 46.2% (12/26), respectively. There were significant correlations between age and concentration/cumulative loading dose (C/D) ratio (P = 0.045), serum creatinine and C/D ratio (P < 0.001) and estimated glomerular filtration rate and C/D ratio (P = 0.005). Serum creatinine was significantly lower when trough levels were <15 μg/mL compared with ≥15 μg/mL. The incidences of renal impairment and hepatic dysfunction were 2.3% and 5.8%, respectively, with no significant difference between <20 and ≥20 μg/mL trough-level groups.

CONCLUSIONS

The recommended loading dose may be insufficient to achieve 15-30 μg/mL in children with normal renal function. In addition, the target trough level ≥20 μg/mL for deep-seated infections seems to be safe in children.