Risk factors and clinical responses of pneumonia patients with colistin-resistantAcinetobacter baumannii-calcoaceticus

Abstract

BACKGROUND Nosocomial infections with carbapenem-resistant Acinetobacter baumannii-calcoaceticus complex (ABC) strains are great problem for intensive care units. ABC strains can develop resistance to all the antibiotics available. Carbapenem resistance is common and colistin resistance is rare in our country. Knowing the risk factors for colistin resistance is important since colistin seems to be the only remaining therapeutic option for the patients with pneumonia due to extensively drug resistant ABC for our country. AIM To investigate the comparison of clinical responses and outcomes between pneumonia patients with colistin-susceptible and -resistant Acinetobacter sp . Strains. METHODS During the study period, 108 patients with pneumonia due to colistin-susceptible strains and 16 patients with colistin-resistant strains were included retrospectively. Continuous variables were compared with the Mann-Whitney U test, and categorical variables were compared using Pearson’s chi-square test or Fisher’s Exact chi-square test for two groups. A binary logistic regression model was developed to identify the potential independent factors associated with colistin resistance in patients with colistin-resistant strains. RESULTS High Acute Physiology and Chronic Health Evaluation II scores (OR = 1.9, 95%CI: 1.4-2.7; P < 0.001) and prior receipt of teicoplanin (OR = 8.1, 95%CI: 1.0-63.3; P = 0.045) were found to be independent risk factors for infection with colistin-resistant Acinetobacter sp . Different combinations of antibiotics including colistin, meropenem, ampicillin/sulbactam, amikacin and trimethoprim/sulfamethoxazole were used for the treatment of patients with colistin-resistant strains. Although the median duration of microbiological cure ( P < 0.001) was longer in the colistin-resistant group, clinical ( P = 0.703), laboratory ( P = 0.277), radiological ( P = 0.551), microbiological response ( P = 1.000) and infection related mortality rates ( P = 0.603) did not differ between the two groups. Among the patients with infections due to colistin-resistant strains, seven were treated with antibiotic combinations that included sulbactam. Clinical (6/7) and microbiological (5/7) response rates were quite high in these patients. CONCLUSION The optimal therapy regimen is unclear for colistin-resistant Acinetobacter sp . infections. Although combinations with sulbactam seems to be more effective in our study patients, data supporting the usefulness of combinations with sulbactam is very limited.

Propranolol, chlorpromazine and diclofenac restore susceptibility of extensively drug-resistant (XDR)-Acinetobacter baumannii to fluoroquinolones

“…They were divided into 12 major profiles according to the number of antimicrobial agents to which they were resistant. It was previously reported that, the high prevalence of MDR, XDR and PDR A. baumannii was due to the misuse of the antimicrobial agents [42,43], or due to the differences in rates of infections by the respective pathogen (which could be an indications of how strictly the hygiene protocols and good manufacturing practice are applied in different hospitals) [44], in addition to the plasticity and endless capacity of A. baumannii genomes [45].…”

Impact of target site mutations and plasmid associated resistance genes acquisition on resistance of Acinetobacter baumannii to fluoroquinolones

“…PDR and most of XDR- A. baumannii were isolated from Assiut university hospitals. The prevalence of MDR, XDR, and PDR A. baumannii could be attributed to the misuse of antimicrobial agents 41 , 42 , or due to the differences in rates of infections by the respective pathogens (mostly related to the degree of strict hygiene protocols applied in different hospitals) 43 , in addition to the plasticity and endless capacity of changes demonstrated in A. baumannii genomes 44 .…”

The pathogenic characteristics and influencing factors of health care-associated infection in elderly care center under the mode of integration of medical care and elderly care service

“…Antibiotics are an important means to treat patients with infection, but unreasonable use can cause flora imbalance and increase the incidence of opportunistic pathogens and drugresistant bacteria infection. [12][13][14] Therefore, according to the results of pathogenic examination and drug sensitivity test, grasp the time of drug use correctly, and abide by the indications of combined drug use strictly. Scientific and rational use of antibiotics is an important means to prevent and control hospital infection in elderly care centers.…”

“…Multiple logistic regression analysis showed that antibiotic agents used was an important factor of HCAI in the elderly care center. Antibiotics are an important means to treat patients with infection, but unreasonable use can cause flora imbalance and increase the incidence of opportunistic pathogens and drug-resistant bacteria infection [12–14] …”