Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features

Bergogne-Bérézin, E; Towner, K. J.

doi:10.1128/cmr.9.2.148

Cited by 1,353 publications

(499 citation statements)

References 212 publications

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“…Clostridium is a widely variable oxygen-tolerant anaerobic genus found in soil, freshwater, marine sediments, animal and human feces, and human clinical isolates such as blood, wounds, and abscesses [39]. It is this ubiquitous nature that likely explains the presence of Clostridium and Clostridiaceae on both cadavers in this study.…”

Section: Resultsmentioning

confidence: 93%

Initial insights into bacterial succession during human decomposition

et al. 2014

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Decomposition is a dynamic ecological process dependent upon many factors such as environment, climate, and bacterial, insect, and vertebrate activity in addition to intrinsic properties inherent to individual cadavers. Although largely attributed to microbial metabolism, very little is known about the bacterial basis of human decomposition. To assess the change in bacterial community structure through time, bacterial samples were collected from several sites across two cadavers placed outdoors to decompose and analyzed through 454 pyrosequencing and analysis of variable regions 3-5 of the bacterial 16S ribosomal RNA (16S rRNA) gene. Each cadaver was characterized by a change in bacterial community structure for all sites sampled as time, and decomposition, progressed. Bacteria community structure is variable at placement and before purge for all body sites. At bloat and purge and until tissues began to dehydrate or were removed, bacteria associated with flies, such as Ignatzschineria and Wohlfahrtimonas, were common. After dehydration and skeletonization, bacteria associated with soil, such as Acinetobacter, were common at most body sites sampled. However, more cadavers sampled through multiple seasons are necessary to assess major trends in bacterial succession.

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Section: Resultsmentioning

confidence: 93%

Initial insights into bacterial succession during human decomposition

et al. 2014

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“…8,12,[17][18][19] Our study involved an outbreak of MDR A. baumannii in 2004 during which most of the patients had been transferred from another hospital, in particular from a respiratory ICU with the diagnosis of acute exacerbation of COPD. In various studies, cross-contamination by transfer of infected and or/colonized patients from one facility to another has been reported to play an important role in epidemics of A. baumannii infection.…”

Section: Discussionmentioning

confidence: 99%

Epidemiology and risk factors for colonization and infection by Acinetobacter baumannii in an ICU in Tunisia, where this pathogen is endemic

Brahmi¹,

Beji²,

Abidi³

et al. 2007

Journal of Infection and Chemotherapy

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“…Acinetobacter baumannii is a gram-negative coccobacillus that causes serious infections in compromised human hosts (Bergogne-Berezin and Towner 1996;Bergogne-Berezin 2001;Villegas and Hartstein 2003). This bacterial pathogen has been observed to cause community-acquired pneumonia as well as nosocomial infections and has recently emerged as a problematic infection for troops wounded in the Middle East (Davis et al 2005;Joly-Guillou 2005;Dijkshoorn et al 2007).…”

Section: Introductionmentioning

confidence: 98%

Iron acquisition functions expressed by the human pathogen Acinetobacter baumannii

et al. 2009

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Acinetobacter baumannii is a gram-negative bacterium that causes serious infections in compromised patients. More recently, it has emerged as the causative agent of severe infections in military personnel wounded in Iraq and Afghanistan. This pathogen grows under a wide range of conditions including iron-limiting conditions imposed by natural and synthetic iron chelators. Initial studies using the type strain 19606 showed that the iron proficiency of this pathogen depends on the expression of the acinetobactin-mediated iron acquisition system. More recently, we have observed that hemin but not human hemoglobin serves as an iron source when 19606 isogenic derivatives affected in acinetobactin transport and biosynthesis were cultured under iron-limiting conditions. This finding is in agreement with the observation that the genome of the strain 17978 has a gene cluster coding for putative hemin-acquisition functions, which include genes coding for putative hemin utilization functions and a TonBExbBD energy transducing system. This system restored enterobactin biosynthesis in an E. coli ExbBD deficient strain but not when introduced into a TonB mutant. PCR and Southern blot analyses showed that this hemin-utilization gene cluster is also present in the 19606 strain. Analysis of the 17978 genome also showed that this strain harbors genes required for acinetobactin synthesis and transport as well as a gene cluster that could code for additional iron acquisition functions. This hypothesis is in agreement with the fact that the inactivation of the basD acinetobactin biosynthetic gene did not affect the growth of A. baumannii 17978 cells under iron-chelated conditions. Interestingly, this second iron uptake gene cluster is flanked by perfect inverted repeats and includes transposase genes that are expressed transcriptionally. Also interesting is the observation that this additional cluster could not be detected in the type strain 19606, an observation that suggests some significant differences in the iron uptake capacity between these two A. baumannii strains. Transposome mutagenesis of the strain 19606 resulted in the isolation of a derivative unable to grow under iron-chelated conditions. Gene mapping and protein analysis together with complementation assays showed that a protein related to SecA, which is a component of the Sec protein secretion system in a wide range of bacteria, is needed at least for the production of the BauA acinetobactin outer membrane receptor. Furthermore, this derivative was unable to use hemin as an iron source under limiting conditions. Taken together, these results indicate that A. baumannii expresses siderophore-mediated and hemin acquisition functions, although different isolates differ in their iron acquisition capacity. Unexpectedly, the ability of this pathogen to acquire iron depends on the expression of a SecA protein secretion function, which has not been associated with iron acquisition in bacteria.

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Acinetobacter spp. as nosocomial pathogens: microbiological, clinical, and epidemiological features

Cited by 1,353 publications

References 212 publications

Initial insights into bacterial succession during human decomposition

Initial insights into bacterial succession during human decomposition

Epidemiology and risk factors for colonization and infection by Acinetobacter baumannii in an ICU in Tunisia, where this pathogen is endemic

Iron acquisition functions expressed by the human pathogen Acinetobacter baumannii

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