Clinical and microbiological efficacy of tigecycline for complicated skin-soft-tissue and intra-abdominal infections in a Turkish university hospital

Simultaneous determination of colistin sulfate and tigecycline in human plasma by liquid chromatography-tandem mass spectrometry method

OBJECTIVE

To establish a high-performance liquid chromatography-tandem mass spectrometry method (HPLC-MS/MS) to simultaneously determine colistin sulfate and tigecycline in human plasma.

METHODS

Polymyxin B1 internal standard (20 µL) was added into 200 µL of plasma sample. The samples were treated with methanol-5% trichloroacetic acid (50:50, V/V) solution, and the protein precipitation method was adopted for post-injection analysis. The chromatographic column was a Dikma C18 (4.6 mm × 150 mm, 5 μm). For the mobile phase, 0.1% formic acid in aqueous solution was used for phase A, 0.1% formic acid in acetonitrile solution for phase B, and gradient elution was also applied. The flow rate was 0.8 mL/min, the column temperature was 40 °C, and the injection volume was 10 µL; Electrospray ionization and multiple reaction ion monitoring were adopted and scanned by the HPLC-MS/MS positive ion mode.

RESULTS

The endogenous impurities in the plasma had no interference in the determination of the analytes. There existed a good linear relationship of colistin sulfate within the range of 0.1-10 µg/mL (R2 = 0.9986), with the lower limit of quantification (LLOQ) of 0.1 µg/mL. There existed a good linear relationship of tigecycline within the range of 0.05-5 µg/ mL (R2 = 0.9987), with the LLOQ of 0.05 µg/mL. The intra- and inter-day relative standard deviations of colistin sulfate and tigecycline were both less than 15%, and the accuracy was between 88.21% and 108.24%. The extraction had good stability, the extraction recovery rate was 87.75-91.22%, and the matrix effect was 99.40-105.26%.

CONCLUSION

This study successfully established a method for simultaneously detecting colistin sulfate and tigecycline plasma concentrations. The method was simple, rapid, and highly sensitive and could be applied for therapeutic medication monitoring.

Tigecycline-Containing Regimens and Multi Drug-Resistant Acinetobacter baumannii: A Systematic Review and Meta-Analysis

Introduction: The use of tigecycline (TG) for the treatment of Acinetobacter baumannii is controversial. In this systematic review and meta-analysis, we aimed to better explore the safety and efficacy of TG for the treatment of multi drug-resistant (MDR) Acinetobacter. Methods: We searched PubMed/MEDLINE, Scopus, Cochrane Central, and Web of Science to identify studies reporting the clinical and microbiological efficacy and safety of regimens containing TG in patients with drug susceptibility testing (DST)-confirmed MDR A. baumannii, published until December 30, 2022. Observational studies were included if they reported clinical and microbiological efficacy of TG-based regimens. The Newcastle-Ottawa Scale (NOS) and Joana Briggs Institute (JBI) critical appraisal tool were used to assess the quality of included studies. Results: There were 30 observational studies, of which 19 studies were cohort and 11 studies were single group studies. Pooled clinical response and failure rates in the TG-containing regimens group were 58.1 (95% confidence interval [CI] 49.2-66.6) and 40.2 (95% CI 31.1-50.0), respectively. The pooled microbiological response rate was 32.1 (95% CI 19.8-47.5), and the pooled all-cause mortality rate was 41.1 (95% CI 34.1-48.4). Pooled clinical response and failure rates in the colistin-based regimens group were 52.7 (42.7-62.5) and 43.1 (33.1-53.8), respectively. The pooled microbiological response rate was 42.9 (16.2-74.5), and the pooled all-cause mortality rate was 34.3 (26.1-43.5). Conclusions: According to our results, the efficacy of the TG-based regimen is the same as other antibiotics. However, our study showed a high mortality rate and a lower rate of microbiological eradication for TG compared with colistin-based regimen. Therefore, our study does not recommend it for the treatment of MDR A. baumannii. However, this was a prevalence meta-analysis of observational studies, and for better conclusion experimental studies are required.

Tigecycline salvage therapy for critically ill children with multidrug-resistant/extensively drug-resistant infections after surgery

OBJECTIVE

The aim of this study was to evaluate the efficacy and safety of salvage therapy of tigecycline in critically ill children with infections caused by multidrug-resistant (MDR)/extensively drug-resistant (XDR) bacteria after surgery.

METHODS

A retrospective chart review was performed of critically ill children after surgery who had received tigecycline for ≥3days between June 2012 and May 2016 in the surgical intensive care unit of a tertiary level children's hospital.

RESULTS

Of 6442 consecutive children admitted after surgery, a total of 22 were enrolled. They had a median age of 7.5 months (interquartile range (IQR), 6 months to 4 years) and a median weight of 7.3kg (IQR, 5.1-12.5kg). Patients received tigecycline for a median 17days (IQR, 12-20 days). The median intensive care unit stay was 56days (IQR, 38-61 days) and median hospital stay was 78days (IQR, 61-94 days). Tigecycline was prescribed as culture-directed therapy in 91% of patients and as empirical therapy in 9%. Clinical success was reported in 86% of the patients. The all-cause mortality in this cohort was 18%. No serious adverse effects of tigecycline were detected in these patients.

CONCLUSIONS

Tigecycline salvage therapy was successful in 86% of critically ill pediatric patients with MDR/XDR infections after surgery, with no severe adverse effects.

Recommendations for intra-abdominal infections consensus report

Guidelines include the recommendations of experts from various specialties within a topic in consideration of data specific to each country. However, to date there has not been a guideline standardizing the nomenclature and offering recommendations for intra-abdominal infections (IAIs) in Turkey. This is mainly due to the paucity of laboratory studies regarding the clinical diagnosis and treatment of IAIs or the sensitivity of microorganisms isolated from patients with IAIs. However, due to the diversification of host characteristics and advancements in technological treatment methods, it has become imperative to 'speak a common language'. For this purpose May 2015, a group of 15 experts in intra-abdominal infections, under the leadership of the Infectious Diseases and Clinical Microbiology Specialty Society of Turkey (EKMUD) and with representatives from the Turkish Surgical Association, Turkish Society of Colon and Rectal Surgery, Hernia Society, Turkish Society of Hepato-pancreato-biliary Surgery, and the Turkish Society of Hospital Infections and Control, was formed to analyze relevant studies in the literature. Ultimately, the suggestions for adults found in this consensus report were developed using available data from Turkey, referring predominantly to the 2010 guidelines for diagnosing and managing complicated IAIs in adults and children by the Infectious Diseases Society of America (IDSA) and the Surgical Infection Society. The recommendations are presented in two sections, from the initial diagnostic evaluation of patients to the treatment approach for IAI. This Consensus Report was presented at the EKMUD 2016 Congress in Antalya and was subsequently opened for suggestions on the official websites of the Infectious Diseases and Clinical Microbiology Specialty Society of Turkey and Turkish Surgical Association for one month. The manuscript was revised according to the feedback received.

Characteristics of superinfections during treatment with tigecycline

Tigecycline has a broad-spectrum in vitro activity against Gram-positive and Gram-negative bacteria, including multidrug-resistant (MDR) strains. However, some Gram-negative bacteria are intrinsically resistant or have reduced susceptibility to tigecycline. We performed a prospective, observational study of 43 patients who received tigecycline as the treatment for serious infections due to MDR Gram-negative microorganisms, to evaluate superinfections. In 60.5% of our patients, tigecycline-resistant (T-R) Gram-negative microorganisms were isolated, representing superinfection in 37.2% and colonization in 23.5%. Pseudomonas aeruginosa was the predominant pathogen (48.4%) followed by Providencia stuartii, Proteus mirabilis and Stenotrophomonas maltophilia. Median time elapsed between tigecycline prescription and isolation of T-R pathogens was 7 days. The 16 superinfections consisted of ventilator-associated pneumonias (43.75%), catheter-related bloodstream infections (37.5%), intra-abdominal infections (12.5%) and urinary tract infection (6.25%). Attributed mortality to superinfections was 31.25%. The comparison of various potential risk factors for isolation of T-R microorganisms did not reveal statistically significant results.