In this study, we divided the clinically used antibiotics into eight categories according to their resistance mechanisms fig. Gut colonization by multidrugresistant and carbapenem. Antimicrobial resistance in carbapenem nonsusceptible acinetobacter baumannii cnsab is a major public health concern globally. Carbapenem resistant acinetobacter baumannii crab are an increasing infectious threat in hospitals. The rate of carbapenem resistance was 93 % in 2012, 88 % in 20 and 91 % in 2014, respectively, while, all carbapenem resistantisolates had mics to imipenem and meropenem 256 mgl. The organisms ability to survive under a wide range of environmental conditions and to persist for extended periods of time on surfaces make it a frequent cause of. Acinetobacter baumannii, antimicrobial resistance one of the main challenges of therapy of infections is the increasingly growing number of multidrugresistant bacteria. Epidemiology of carbapenemaseproducing enterobacteriaceae. Acinetobacter baumannii, a nonmotile, glucose non fermentative, oxidase negative, encapsulated, gramnegative coccobacillus, has recently gained importance because of its increasing resistance to the available antibiotics.
Acinetobacter baumannii is an opportunistic pathogen that is frequently involved in outbreaks of infection, occurring mostly in intensive care units. We investigated 118 patients, on 27 wards, in whom mdr a. Acinetobacter baumannii is an emerging bacterial pathogen that causes nosocomial pneumonia and other infections. Mechanisms of colistin resistance in two sets of clinical isolates. Antibioticresistant acinetobacter baumannii increasing. Drugresistant profiles of the clinically isolated a. Jul 24, 2017 drugresistant profiles of the clinically isolated a. Carbapenemases found in acinetobacter belong to molecular class d oxa enzymes or class b metalloenzymes of imp and vimtype or sim1. Acinetobacter baumannii is an opportunistic gramnegative pathogen with increasing relevance in a variety of nosocomial infections especially among intensivecareunit icu patients. Molecular epidemiology and mechanisms of carbapenem resistance in acinetobacter baumannii endemic in new york city. Although it is recognized as an increasing threat to immunocompromised patients, the mechanism of host defense against a. Of great concern is the increase in carbapenem resistance reported among these organisms over the last decade 2. Prevalence and mechanisms of carbapenem resistance among. Acinetobacter baumannii is a typically short, almost round, rodshaped coccobacillus gramnegative bacterium.
Recent trends show many infections are caused by carbapenemresistant or even extensively drugresistant. The most common mechanism for carbapenem resistance in a. We investigated the clinical epidemiology of crab infections vs. Antimicrobial resistance in acinetobacter baumannii is a growing public health concern and an important pathogen in nosocomial infections. Request pdf prevalence and mechanisms of carbapenem resistance among acinetobacter baumannii clinical isolates in egypt the increasing number of carbapenem resistant acinetobacter baumannii. We investigated the genes involved in resistance to carbapenems and cephalosporins in clinical a. Drug treatment for multidrugresistant acinetobacter. Pseudomonas aeruginosa and acinetobacter baumannii are gramnegative bacilli that in the last decades have become prevalent agents of hospital infection due to high antimicrobial resistance developed by these microorganisms. The origin and epidemiological characteristics of the strains used. The treatment of these infections is often difficult due to the acquisition of resistance genes. Multidrug resistant acinetobacter baumannii and its closely related species a.
Molecular epidemiology of carbapenem resistant acinetobacter. Apr 15, 2008 resistance mechanisms for acinetobacter species are similar to those for pseudomonas species, although acinetobacter species have not been studied as extensively 67, 68. Emergence and rapid spread of carbapenem resistance during a large and sustained hospital outbreak of multiresistant acinetobacter baumannii. In addition, they showed a high resistance against amikacin 3436, 94. The genus acinetobacter consists of aerobic, gramnegative bacilli that.
Carbapenem resistance among acinetobacter baumannii isolates is rapidly increasing and has been widely implicated in nosocomial infections and hospital outbreaks. Prevalence of acinetobacter baumannii in saudi arabia. This study focuses on the dissemination of plasmidborne carbapenemase genes in gramnegative bacteria in tamil nadu, india. Acinetobacter baumannii is a leading cause of healthcareassociated infections worldwide. Wide distribution of carbapenem resistant acinetobacter. Genome dynamics of multidrugresistant acinetobacter. Acinetobacter baumannii is emerging as an important nosocomial pathogen worldwide. Due to the prevalence of infections and outbreaks caused by multidrug resistant a. The acinetobacter genus consists of over 50 species, most of which are ubiquitous in the environment, have low pathogenicity, but can infect humans as opportunistic pathogens. The 2017 world health organization who global priority list of pathogens ranks carbapenem resistant enterobacteriaceae cre, carbapenem resistant pseudomonas aeruginosa, and carbapenem resistant acinetobacter baumannii in the highest priority category ie, critical. Multifacility outbreaks can be also sustained by interhospital transfer of colonized patients. Emerging antibiotic resistance medical and molecular microbiology unit, department of.
Molecular epidemiology of carbapenemnonsusceptible. In order to better understand transmission and evolutionary dynamics of mdr acinetobacter baumannii ab during longterm infection, we analyzed genomes from a series of isolates from individual. During the study period, 1116 carbapenem resistant a. Mechanisms of resistance to carbapenems in meropenem. From january to june 2009, 75 crab strains were collected. Alarming levels of antimicrobial resistance among a. These resistance mechanisms pose a serious therapeutic threat, since carbapenems are frequently used to treat otherwise resistant a. All isolates were subjected to pulsedfield gel electrophoresis pfge. The identification of drug resistance mechanisms in a. Limited treatment options are available for patients infected with multidrug mdr or pandrug pdrresistant bacterial pathogens, resulting in infections that can persist for weeks or months.
Because of various intrinsic and acquired mechanisms of resistance, most. Acinetobacter infections have increased and gained attention because of the organisms prolonged environmental survival and propensity to develop antimicrobial drug resistance. Carbapenem resistance, acinetobacter baumanniicomplex, surveillance, epidemiology, temporal trends, regional trends background in the gramnegative, strictly aerobic acinetobacter genus, the species that mostly present a risk as opportunistic. Prevalence of carbapenem resistant pseudomonas aeruginosa. The emergence of a novel sequence type of mdr acinetobacter. Carbapenemresistant acinetobacter baumannii from brazil. The organism has the ability to accumulate diverse mechanisms of resistance, leading to the emergence of strains that are resistant to all commerciallyavailable antibiotics.
A retrospective, matched cohort investigation was performed at 2 baltimore hospitals to examine outcomes of. Acinetobacter baumannii is a pleomorphic aerobic gramnegative bacillus similar in appearance to haemophilus influenzae on gram stain commonly isolated from the hospital environment and hospitalized patients. Aug 21, 2010 infections caused by acinetobacter baumannii are a threat to neonates because of its resistance to antimicrobials, including carbapenems. Carbapenem resistance in gramnegative bacteria has become a worldwide problem. In this study, we aimed to investigate the antibiotic susceptibility patterns and the clonal relationship of a. Multidrugresistant acinetobacter baumannii, russia. In the present study, 50 clinical isolates of multidrug resistant mdra. Molecular epidemiology and mechanisms of tigecycline resistance in clinical. The genus acinetobacter consists of aerobic, gramnegative bacilli that comprise 33 differentiated species, of which only ten. Clinical antibioticresistant acinetobacter baumannii strains. Mobile genetic elements related to carbapenem resistance. This is a pdf file of an unedited manuscript that has been accepted for publication.
Molecular epidemiology and clinical impact of acinetobacter. Carbapenem resistance in acinetobacter baumannii request pdf. Infections caused by acinetobacter baumannii are a threat to neonates because of its resistance to antimicrobials, including carbapenems. Here, we analyzed the basis of carbapenem resistance in clinical a. Mechanisms of carbapenem resistance in acinetobacter baumannii. Acinetobacter baumannii is widely recognized as an important pathogen associated with nosocomial infections. The mechanisms of resistance generally fall into 3 categories. Carbapenemresistant acinetobacter baumannii in healthcare.
This study determined the antibiotic resistance and molecular epidemiology of cnsab isolates from a referral burn center in tehran, iran. Introduction acinetobacter is a gramnegative coccobacillus that has emerged from an organism of questionable pathogenicity to an infectious agent of importance to hospitals worldwide. Carbapenem resistance in gramnegative bacteria is an ongoing publichealth problem of global dimensions leaving very few treatment options for severely infected patients. The increasing trend of carbapenem resistance in acinetobacter baumannii worldwide is a concern since it limits drastically the range of therapeutic alternatives. To overcome this problem, knowledge of the pathogenesis and antibiotic resistance mechanisms of a.
Antibioticresistant infectious bacteria currently imply a high risk and therefore constitute a strong challenge when treating patients in hospital settings. Molecular mechanisms of antimicrobial resistance in. Mechanisms of antibiotic resistance of this organism, including acquirement of. The present study is a retrospective analysis of all positive cultures for these microorganisms in the period of january 2004 to december 2008. Carbapenem resistance in acinetobacter baumannii article in clinical microbiology and infection 129. Zarrilli et al carbapenem resistance in acinetobacter baumannii j infect dev ctries 2009. While other species of the genus acinetobacter are often found in. The relevance of acinetobacter baumannii as a problematic microorganism in inpatient. To overcome this problem, knowledge of the pathogenesis. Evolution of carbapenem resistance in acinetobacter. Molecular epidemiology and mechanisms of carbapenem. We report molecular epidemiology of 65 carbapenem nonsusceptible a.
Molecular mechanisms of antimicrobial resistance in acinetobacter baumannii molecular epidemiology of a. Multidrug resistant acinetobacter baumannii is a rapidly emerging pathogen in the health care setting, where it causes infections that include bacteremia, pneumonia, meningitis, urinary tract infection, and wound infection. Treatment options for carbapenemresistant and extensively. Multidrugresistant acinetobacter infection mortality rate. Carbapenems have been widely used to treat serious multidrugresistant a.
Acinetobacter baumannii is undoubtedly one of the most successful pathogens responsible for hospitalacquired nosocomial infections in the modern healthcare system. In addition, carbapenemresistant organisms cro have recently. Epidemiology and molecular characterization of multidrug. Review article carbapenem resistance in acinetobacter. Prevalence of carbapenem resistant pseudomonas aeruginosa and. Carbapenem resistance in acinetobacter baumannii j infect dev ctries 2009. Clinical antibioticresistant acinetobacter baumannii. Acinetobacter baumannii is known for nosocomial outbreaks worldwide.
Carbapenem resistance, acinetobacter baumanniicomplex, surveillance, epidemiology, temporal trends, regional trends background in the gramnegative, strictly aerobic acinetobacter genus, the species that mostly present a risk as opportunistic human pathogens are a. Mobile genetic elements related to carbapenem resistance in. The emergence and global spread of carbapenemaseproducing enterobacteriaceae and acinetobacter baumannii are of great concern to health services worldwide. Carbapenems are considered firstline agents for the treatment of a. Molecular epidemiology of carbapenem resistant acinetobacter baumannii carrying isaba1blaoxa51 like genes 1. The acinetobacter baumannii calcoaceticus abc complex has emerged as an important nosocomial pathogen. Acinetobacter baumannii is a particularly challenging pathogen because it is associated with a high degree of resistance, and it is difficult to eliminate its environmental reservoir in healthcare settings. Epidemiology and impact of imipenem resistance in acinetobacter baumannii article in infection control and hospital epidemiology 3012.
The strains loss of lps was tested to be colistin resistance. Carbapenems are the antibiotics of choice to treat infections caused by acinetobacter baumannii, and resistance to this class can be determined by loss of membrane permeability and enzymatic mechanisms. Acinetobacter baumannii is a gramnegative pathogen often associated with nosocomial infections, including bacteraemia, pneumonia, meningitis and urinary tract infections. An investigation of drugresistant acinetobacter baumannii. It can be an opportunistic pathogen in humans, affecting people with compromised immune systems, and is becoming increasingly important as a hospitalderived infection. Multiple antibiotic resistance occurs in both grampositive and in gramnegative bacteria. Epidemiological and molecular analysis of virulence and antibiotic.
Molecular epidemiology of carbapenem nonsusceptible. Emerging broadspectrum resistance in pseudomonas aeruginosa. The present study is a retrospective analysis of all positive cultures. They are mostly of the kpc, vim, imp, ndm, and oxa48 types. Of these, acinetobacter baumannii, acinetobacter nosocomialis and acinetobacter. Prevalence of carbapenem resistance genes in acinetobacter. Biofilm formation patterns among acinetobacter baumannii isolates. Oct 20, 2015 antimicrobial resistance in carbapenem nonsusceptible acinetobacter baumannii cnsab is a major public health concern globally. May 10, 2017 acinetobacter baumannii is known for nosocomial outbreaks worldwide. Rapid dissemination of colistin and carbapenem resistant. To understand the epidemiology of multidrugresistant mdr acinetobacter baumannii and define individual risk factors for mdr, we used epidemiologic methods, performed organism typing by pulsedfield gel electrophoresis pfge, and conducted a matched casecontrol retrospective study. In this study, we examined the potential role of macrophages in host defense against a.
Prevalence of carbapenemresistant acinetobacter baumannii. Citeseerx document details isaac councill, lee giles, pradeep teregowda. Epidemiology and diagnostics of carbapenem resistance in. Multidrugresistant acinetobacter baumannii volume 11. Acinetobacter baumannii is an important opportunistic pathogen due to its capabilities for developing mechanisms of resistance to a wide range of antimicrobial agents including carbapenems. The southeast asian region has a history of high prevalence of multidrugresistant gramnegative bacteria mdrgn including extendedspectrum. We report molecular epidemiology of 65 carbapenemnonsusceptible a. Acinetobacter baumannii is a common causative agent of hospitalacquired infections and a leading cause of infection in burns patients. Characterization of these species and of particular strains is a priority for the establishment of diagnostic tests and preventive procedures. Dissemination of carbapenemresistance and plasmids.