Bloodstream infections caused by Acinetobacter species with reduced susceptibility to tigecycline: clinical features and risk factors

Evaluation of role of Tigecycline among clinically significant multidrug resistant pathogens from a tertiary care hospital

Background

Tigecycline, a glycylcycline antibiotic is a promising option for the treatment of single or multidrug resistant pathogens. The aim of the study was to evaluate the in-vitro Tigecycline susceptibility of various pathogens from clinical samples received at the tertiary care hospitals in South India.

Methods

The analysis of specimens from patients admitted were carried out in this prospective cross sectional study. The identification and antimicrobial susceptibility testing was performed by semi-automated Vitek 2 systems and Kirby Bauer method. Pattern of data analysis was done by descriptive statistics.

Results

Among 2574 isolates, 812 isolates were Gram positive pathogens and 1762 isolates were Gram negative pathogens. Resistance to Tigecycline was more common among Gram negative pathogens (18.62%) in comparison to the Gram positive pathogens (0.49%). Among 740 Extended Spectrum Beta Lactamases (ESBL) producers such as Klebsiella species & E coli, 629 isolates were susceptible, and 93 isolates were resistant to the tigecycline. All the methicillin resistant Staphylococcus aureus (MRSA) isolates were susceptible to tigecycline.

Conclusion

Multidrug resistant (MDR) pathogens like Acinetobacter species, and Klebsiella species were found to be highly effective in vitro to tigecycline for elimination of infections caused by both Gram positive and Gram negative pathogens. The use of combination therapy becomes crucial to prevent the development of Pan Drug resistance.

Clinical experience with tigecycline in the treatment of hospital-acquired pneumonia caused by multidrug resistant Acinetobacter baumannii

Background

Tigecycline, with broad in vitro antibacterial activity, has been widely used off-label for nosocomial pneumonia caused by multi-drug resistant Acinetobacter baumannii (MDRAB). However, many concerns have been raised about the efficacy of tigecycline treatment as the inconsistent results from previous clinical studies.

Methods

This retrospective study evaluated the outcome of adult patients with monomicrobial MDRAB nosocomial pneumonia treated with tigecycline between 2015 and 2017. Results.

A total of 77 patients was eligible for this study, and the overall clinical success and 30-day survival rates were 70.03 and 70.13%, respectively, however, the microbiological eradication rate was relatively low (48%). Multivariate analysis indicated that shorter duration of tigecycline use associated with increased clinical failure, whereas higher CURB65 scores, mechanical ventilation and tigecycline resistant to MDRAB have significant association with 30-day mortality.

Conclusions

Our results suggest that tigecycline is one of the potential choices for the treatment of hospital-acquired pneumonia caused by MDRAB, especially with a MIC≤2 mg/L. In addition, a longer duration of tigecycline treatment may be required to insure better clinical outcomes.

Risk factors with the development of infection with tigecycline- and carbapenem-resistant Enterobacter cloacae

Background

Tigecycline is regarded as a last resort treatment for carbapenem-resistant Enterobacter cloacae (CREC) infections, and increasing numbers of tigecycline- and carbapenem-resistant E. cloacae (TCREC) isolates have been reported in recent years. However, risk factors and clinical impacts of these isolates are poorly characterized.

Patients and methods

We conducted a retrospective case-case-control study of hospitalized patients with TCREC infection during the period 2012-2016 in Chongqing, China. Case patients with TCREC and those with CREC were compared to a control group with no E. cloacae infection. Multivariate logistic regression models were used to identify independent risk factors for acquiring TCREC and CREC.

Results

A total of 36 TCREC cases, 36 CREC cases, and 100 controls were enrolled in our study. Multivariable analysis indicated that nasal catheter (OR: 8.9; 95% CI: 1.1-75.2), exposure to penicillin (OR: 95.9; 95% CI: 8.9-1038.3), aminoglycosides (OR: 42.1; 95% CI: 2.1-830.6), and fluoroquinolones (OR: 18.6; 95% CI: 1.9-185.6) were independent predictors for acquiring TCREC. In addition, venous catheterization (OR: 12.2; 95% CI: 2.5-58.5), penicillin (OR: 30.8; 95% CI: 7.9-120.0), and broad-spectrum cephalosporin (OR: 5.0; 95% CI: 1.5-17.3) were independently associated with CREC acquisition.

Conclusion

Reasonable antibiotic stewardship programs and surveillance are necessary to control the tigecycline resistance among high-risk patients.

Molecular epidemiology and risk factors for colistin- or tigecycline-resistant carbapenemase-producing Klebsiella pneumoniae bloodstream infection in critically ill patients during a 7-year period

A matched 1:2 case-control study was conducted among critically ill patients in order to identify the risk factors of colistin or tigecycline-resistant carbapenemase-producing Klebsiella pneumoniae (ColR-Kp, TigR-Kp) bacteraemia. MIC to colistin and tigecycline were determined by Etest. From 224 bacteraemic patients, 46.4% and 29.5% were resistant to colistin and tigecycline, respectively. PCR revealed that 199 isolates carried the bla_KPC gene. PCR revealed that no isolate carried the mcr-1 gene. Risk factors for ColR-Kp bacteraemia as compared to patients with bacteraemia by a colistin-susceptible isolate or patients without carbapenemase-producing K. pneumoniae bacteraemia were colistin or tigecycline administration and tracheostomy, while TigR-Kp bacteraemia as compared to either patients with bacteraemia by tigecycline-susceptible isolate or patients without carbapenemase-producing K. pneumoniae bacteraemia were colistin or tigecycline administration, number of comorbidities and prior bacteraemia by a Gram-negative pathogen. Administration of colistin and tigecycline predisposed to development of bacteraemia by either ColR-Kp or TigR-Kp.

Determinants of Mortality in Patients with Nosocomial Acinetobacter baumannii Bacteremia in Southwest China: A Five-Year Case-Control Study

Purpose

This study was aimed to identify the determinants of in-hospital mortality in Acinetobacter baumannii (A. baumannii) bacteremia and to assess impact of carbapenem resistance on mortality.

Methods

A five-year case-control study was conducted from January 2011 to December 2015 in a tertiary teaching hospital with 3200 beds, Southwest China. Clinical outcomes and potential determinants of mortality in patients with nosocomial A. baumannii bacteremia and carbapenem-resistant A. baumannii (CRAB) bacteremia were evaluated using Cox and logistic regression analyses.

Results

A total of 118 patients with nosocomial A. baumannii bacteremia were included. Seventy-one percent (84/118) of them had carbapenem-resistant A. baumannii (CRAB) bacteremia. The in-hospital mortality of nosocomial A. baumannii bacteremia was 21.2%, and the attributable in-hospital mortality rate due to CRAB was 21.5%. Significant difference of 30-day in-hospital mortality in the Kaplan-Meier curves was found between CRAB and CSAB groups (log-rank test, P=0.025). The Cox regression analysis showed that patients with CRAB bacteremia had 2.72 times higher risk for 30-day in-hospital mortality than did those with carbapenem-susceptible A. baumannii (CSAB) bacteremia (95% confidence intervals (CIs) 1.14-6.61, P=0.016). The logistic regression analysis reported that mechanical ventilation and respiratory tract as origin of bacteremia were independent predictors of mortality among patients with nosocomial A. baumannii bacteremia and CRAB bacteremia, while high APACHE II score on the day of bacteremia and multiple organ dysfunction syndromes (MODS) during hospitalization were independent predictors of mortality among patients with nosocomial A. baumannii bacteremia but not CRAB bacteremia.

Conclusion

It was the severity of illness (high APACHE II score and MODS) not carbapenem resistance that highlighted the mortality of patients with nosocomial A. baumannii bacteremia. The impact of mechanical ventilation on mortality suggested that respiratory dysfunction might prime the poor outcome. Protection of respiratory function during the progression of nosocomial A. baumannii bacteremia should be given more importance. Early identification and intervention of patients with nosocomial A. baumannii bacteremia in critical ill conditions were advocated.