Acinetobacter baumannii in the critically ill: complex infections get complicated

Abstract

Acinetobacter baumannii is increasingly associated with various epidemics, representing a serious concern due to the broad level of antimicrobial resistance and clinical manifestations. During the last decades, A. baumannii has emerged as a major pathogen in vulnerable and critically ill patients. Bacteremia, pneumonia, urinary tract, and skin and soft tissue infections are the most common presentations of A. baumannii, with attributable mortality rates approaching 35%. Carbapenems have been considered the first choice to treat A. baumannii infections. However, due to the widespread prevalence of carbapenem-resistant A. baumannii (CRAB), colistin represents the main therapeutic option, while the role of the new siderophore cephalosporin cefiderocol still needs to be ascertained. Furthermore, high clinical failure rates have been reported for colistin monotherapy when used to treat CRAB infections. Thus, the most effective antibiotic combination remains disputed. In addition to its ability to develop antibiotic resistance, A. baumannii is also known to form biofilm on medical devices, including central venous catheters or endotracheal tubes. Thus, the worrisome spread of biofilm-producing strains in multidrug-resistant populations of A. baumannii poses a significant treatment challenge. This review provides an updated account of antimicrobial resistance patterns and biofilm-mediated tolerance in A. baumannii infections with a special focus on fragile and critically ill patients.

In vitro and in silico assessment of anti-biofilm and anti-quorum sensing properties of 2,4-Di-tert butylphenol against Acinetobacter baumannii

“…Global rates of A. baumannii infections are approximately 1 million per year with high mortalities, especially in intensive care units (ICUs). A. baumannii infected patient mortalities have been reported as high as 35 % with 83 % mortalities attributed to pneumonia patients [6][7][8]. Higher infection rates and deaths have been reported in Mediterranean, sub-Saharan Africa and South Asia regions [9].…”

Risk factors and genetic characteristics of the carriage of hypervirulent and carbapenem-resistant Acinetobacter baumannii among pregnant women

“…As a pivotal pathogen of global concern, carbapenem-resistant Acinetobacter baumannii (CRAB) is intrinsically linked with severe, sometimes fatal, infections, prompting wide-ranging epidemiological research ( Li et al, 2020 ; Cavallo et al, 2023 ; Diep et al, 2023 ). Efforts to understand and track the epidemiology of AB have employed a variety of genotyping methods, revealing the pathogen’s sophisticated population dynamics.…”

“…Pregnant women who undergo physiological immunological changes, present a notable risk group for acquiring or reactivating infections ( Hazenberg et al, 2021 ; Osei Sekyere et al, 2021 ), and who are carriers of AB are not only more predisposed to associated infections at an uncertain time during pregnancy, intrapartum or postpartum period, but also have a risk of maternal carriers transferring the AB to their newborns ( Sood et al, 2019 ; Osei Sekyere et al, 2021 ). AB as a cause of pneumonia, urinary tract infections, and sepsis ( Cavallo et al, 2023 ), has manifested among pregnant women and newborns in numerous countries ( Sood et al, 2019 ; Osei Sekyere et al, 2021 ; Ghanchi et al, 2023 ; Odoyo et al, 2023 ; Woon et al, 2023 ), inciting adverse outcomes including spontaneous abortion, premature labor, and perinatal deaths ( Aivazova et al, 2010 ; He et al, 2013 ; Osei Sekyere et al, 2021 ). Although the World Health Organization (WHO) estimates that puerperal sepsis accounts for 10.68% of maternal deaths, antepartum screening for AB remains scant, with prevailing data often emerging from retrospective studies and postpartum examinations ( Say et al, 2014 ; Bebell et al, 2017 ; Osei Sekyere et al, 2021 ; Sousa et al, 2023 ).…”

“…Since the early 1970s, various reports have repeatedly emphasized the role of asymptomatic patients as a reservoir of pathogens, thus favoring their persistent colonization and extensive dissemination, and patients with positive surveillance cultures were eight times more likely to develop CRAB infections ( Latibeaudiere et al, 2015 ), even after controlling for other variables, which emphasize the need for active surveillance for multidrug-resistant organisms and the value of molecular typing of strains to investigate their transmission and distribution features. Although there have been reported the skin or rectum being the site of higher carriage rate of CRAB ( Nutman et al, 2020 ; Osei Sekyere et al, 2021 ), buccal mucosa also remains one of the most reliable sample sources to screen for its carriers ( Nutman et al, 2016 ; Zhou et al, 2018 ; Cavallo et al, 2023 ; Da Silva et al, 2023 ). The oropharyngeal swabs, while may not be the best but the most viable option, could reduce sampling difficulty by healthcare professionals and enhance acceptability among pregnant women.…”

The Use of CHROMID® Colistin R for the Detection of Colistin-Resistant Gram-Negative Bacteria in Positive Blood Cultures

“…In recent years, colistin has been increasingly used as a last resort treatment for multidrug-resistant (MDR) Gram-negative bacteria causing serious infections such as bacteraemia or hospital-acquired pneumonia [ 1 , 2 , 3 , 4 , 5 ]. Treatment with colistin commonly results in nephrotoxicity and, especially as monotherapy, is associated with poor clinical outcomes [ 6 ].…”