scholarly journals Transmission of Hypervirulent Acinetobacter baumannii Between General and Intensive Care Unit

2020 ◽  
Author(s):  
Min Zhang ◽  
Jinyong Zhang ◽  
Shiyi Liu ◽  
Yuxin Zhong ◽  
Yuemei Lu ◽  
...  

Abstract Background Acinetobacter baumannii is one of the most important microorganisms associated with hospital-acquired infections and nosocomial outbreaks.Aim We investigate a hypervirulent A. baumannii outbreak with aim to identify the transmission mediator.Methods We investigated an outbreak in respiratory intensive critical care unit (RICU) and respiratory medicine unit (RMU) based on whole genome sequencing (WGS) and epidemiology data. Virulence potential was performed in a mouse model.Results Eight and two CRAB isolates were isolated in RICU and RMU during August 2018. Four fatal cases were all involved in a transmission event. In vivo test confirmed the hypervirulence phenotype of the isolates. We inferred that the portable devices were probably the mediator of the transmission based on the transmission chain and epidemiology data. We isolated an hypervirulent CRAB from the screen of portable ventilator. Portable devices disinfection using vaporized hydrogen peroxide and avoiding the sharing of devices between general ward and ICU successfully blocked the further transmission.Conclusions An emerging hypervirulent A. baumannii with enhanced virulence has successfully colonized on the surface of mobile medical device. Sharing these mobile devices may lead to spread between the general ward and ICU. The new transmission chain construction tool is useful to the outbreak investigation.

Antibiotics ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 56
Author(s):  
Dalila Mil-Homens ◽  
Maria Martins ◽  
José Barbosa ◽  
Gabriel Serafim ◽  
Maria J. Sarmento ◽  
...  

Klebsiella pneumoniae, one of the most common pathogens found in hospital-acquired infections, is often resistant to multiple antibiotics. In fact, multidrug-resistant (MDR) K. pneumoniae producing KPC or OXA-48-like carbapenemases are recognized as a serious global health threat. In this sense, we evaluated the virulence of K. pneumoniae KPC(+) or OXA-48(+) aiming at potential antimicrobial therapeutics. K. pneumoniae carbapenemase (KPC) and the expanded-spectrum oxacillinase OXA-48 isolates were obtained from patients treated in medical care units in Lisbon, Portugal. The virulence potential of the K. pneumonia clinical isolates was tested using the Galleria mellonella model. For that, G. mellonella larvae were inoculated using patients KPC(+) and OXA-48(+) isolates. Using this in vivo model, the KPC(+) K. pneumoniae isolates showed to be, on average, more virulent than OXA-48(+). Virulence was found attenuated when a low bacterial inoculum (one magnitude lower) was tested. In addition, we also report the use of a synthetic polycationic oligomer (L-OEI-h) as a potential antimicrobial agent to fight infectious diseases caused by MDR bacteria. L-OEI-h has a broad-spectrum antibacterial activity and exerts a significantly bactericidal activity within the first 5-30 min treatment, causing lysis of the cytoplasmic membrane. Importantly, the polycationic oligomer showed low toxicity against in vitro models and no visible cytotoxicity (measured by survival and health index) was noted on the in vivo model (G. mellonella), thus L-OEI-h is foreseen as a promising polymer therapeutic for the treatment of MDR K. pneumoniae infections.


2018 ◽  
Vol 201 (2) ◽  
Author(s):  
Carly Ching ◽  
Brendan Yang ◽  
Chineme Onwubueke ◽  
David Lazinski ◽  
Andrew Camilli ◽  
...  

ABSTRACTAcinetobacter baumanniiis a Gram-negative opportunistic pathogen that is known to survive harsh environmental conditions and is a leading cause of hospital-acquired infections. Specifically, multicellular communities (known as biofilms) ofA. baumanniican withstand desiccation and survive on hospital surfaces and equipment. Biofilms are bacteria embedded in a self-produced extracellular matrix composed of proteins, sugars, and/or DNA. Bacteria in a biofilm are protected from environmental stresses, including antibiotics, which provides the bacteria with selective advantage for survival. Although some gene products are known to play roles in this developmental process inA. baumannii, mechanisms and signaling remain mostly unknown. Here, we find that Lon protease inA. baumanniiaffects biofilm development and has other important physiological roles, including motility and the cell envelope. Lon proteases are found in all domains of life, participating in regulatory processes and maintaining cellular homeostasis. These data reveal the importance of Lon protease in influencing keyA. baumanniiprocesses to survive stress and to maintain viability.IMPORTANCEAcinetobacter baumanniiis an opportunistic pathogen and is a leading cause of hospital-acquired infections.A. baumanniiis difficult to eradicate and to manage, because this bacterium is known to robustly survive desiccation and to quickly gain antibiotic resistance. We sought to investigate biofilm formation inA. baumannii, since much remains unknown about biofilm formation in this bacterium. Biofilms, which are multicellular communities of bacteria, are surface attached and difficult to eliminate from hospital equipment and implanted devices. Our research identifies multifaceted physiological roles for the conserved bacterial protease Lon inA. baumannii. These roles include biofilm formation, motility, and viability. This work broadly affects and expands understanding of the biology ofA. baumannii, which will permit us to find effective ways to eliminate the bacterium.


2013 ◽  
Vol 8 (5) ◽  
pp. 1934578X1300800 ◽  
Author(s):  
Andreia F. Duarte ◽  
Susana Ferreira ◽  
Rosário Oliveira ◽  
Fernanda C. Domingues

The increasing incidence of hospital-acquired infections caused by multi-drug resistant pathogens, such as Acinetobacter baumannii, coupled with the low efficacy of drugs and rising treatment costs has created interest in the potential antimicrobial properties of natural products. The main objective of this work was to determine the effect of coriander essential oil on Acinetobacter baumannii in different growth phases, as well as its ability to inhibit the formation or eradication of biofilms. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of coriander oil using a microdilution broth susceptibility assay was determined. The effects of different concentrations of coriander oil (ranging from 0.125 to 4×MIC) on biofilm formation and on established biofilm were tested using 96-well microtiter plates. Crystal violet assay was used as indicator of total biofilm biomass and the biofilm viability was assessed with a XTT staining method. It was found that coriander oil presented significant antibacterial activity against all tested strains of A. baumannii, with MIC values between 1 and 4 μL/mL. The MBC values were the same as the MIC, being an indicator of the bactericidal activity of this essential oil. In what concerns the effect of this essential oil on biofilm formation inhibition was observed of at least 85% of biomass formation by all A. baumannii strains using 2×MIC of coriander oil, in addition to a decrease in the metabolic activity of the cells. After exposure to coriander oil, a decrease in 24 h and 48 h-old biofilm biomass and metabolism was seen for all tested concentrations, even with sub-inhibitory concentrations. Coriander essential oil proved to have a significant antibacterial and anti-biofilm activity and should be considered in the development of future disinfectants to control A. baumannii dissemination.


2018 ◽  
Vol 10 (1) ◽  
pp. 43-46
Author(s):  
Adil Fouad ◽  
Fatiha Bennaoui ◽  
Nadia El Idrissi Slitine ◽  
Nabila Soraa ◽  
FMR Maoulainine

Imipenem-resistant Acinetobacter baumannii meningitis is a hospital-acquired infection, the treatment of which constitutes a real therapeutic challenge. In this article, together with a review of the literature, we report two cases of imipenem-resistant Acinetobacter baumannii neonatal meningitis following ruptured myelomeningocele, treated with intravenous colistin with favorable results. In recent years, Acinetobacter baumannii has become a more and more commonly described pathogen in hospital-acquired infections. However, the cases of meningitis are mainly postoperative and are still not quite frequently described in the literature. Colistin appears to be preferably administered intravenously at a dose of 100.000 IU/kg/day.


Author(s):  
Stephanie A. Halasohoris ◽  
Jennifer M. Scarff ◽  
Lisa M. Pysz ◽  
Sanae Lembirik ◽  
Margaret M. Lemmon ◽  
...  

AbstractAntimicrobial-resistance (AMR) has become an increasingly difficult issue to overcome for bacteria associated with both community- and hospital-acquired infections as well as potential biodefense threats. The need to identify new therapeutics of novel classes and/or with unique mechanisms is critical to combatting AMR in the coming years. GT-1 (LCB10-0200), a siderophore-linked cephalosporin, is one such novel option and is formulated to be used either alone or in combination with a novel broad-spectrum β-lactamase inhibitor, GT-055 (LCB18-055). This study assessed the in vitro and in vivo efficacy of GT-1 and GT-055 against a broad array of multi-drug resistant and biothreat pathogens. Here, we demonstrated sub-4 µg ml−1 efficacy against a number of pathogens in vitro. We further determined that in mice infected via aerosol route with Yersinia pestis, efficacy of GT-1/GT-055 treatment is at least equivalent to the comparator antibiotic, ciprofloxacin.


2009 ◽  
Vol 53 (9) ◽  
pp. 4013-4014 ◽  
Author(s):  
I. Roca ◽  
S. Marti ◽  
P. Espinal ◽  
P. Martínez ◽  
I. Gibert ◽  
...  

ABSTRACT Acinetobacter baumannii has been increasingly associated with hospital-acquired infections, and the presence of multidrug resistance strains is of great concern to clinicians. A. baumannii is thought to possess a great deal of intrinsic resistance to several antimicrobial agents, including chloramphenicol, although the mechanisms involved in such resistance are not well understood. In this work, we have identified a major facilitator superfamily efflux pump present in most A. baumannii strains, displaying strong substrate specificity toward chloramphenicol.


2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Mélyssa Cambronel ◽  
Damien Tortuel ◽  
Kelly Biaggini ◽  
Olivier Maillot ◽  
Laure Taupin ◽  
...  

AbstractMicrobial endocrinology has demonstrated for more than two decades, that eukaryotic substances (hormones, neurotransmitters, molecules of the immune system) can modulate the physiological behavior of bacteria. Among them, the hormones/neurotransmitters, epinephrine (Epi) and norepinephrine (NE), released in case of stress, physical effort or used in medical treatment, were shown to be able to modify biofilm formation in various bacterial species. In the present study, we have evaluated the effect of Epi on motility, adhesion, biofilm formation and virulence of Pseudomonas aeruginosa, a bacterium linked to many hospital-acquired infections, and responsible for chronic infection in immunocompromised patients including persons suffering from cystic fibrosis. The results showed that Epi increased adhesion and biofilm formation of P. aeruginosa, as well as its virulence towards the Galleria mellonella larvae in vivo model. Deciphering the sensor of this molecule in P. aeruginosa and the molecular mechanisms involved may help to find new strategies of treatment to fight against this bacterium.


Author(s):  
Septimiu Voidazan ◽  
Sorin Albu ◽  
Réka Toth ◽  
Bianca Grigorescu ◽  
Anca Rachita ◽  
...  

Background: Hospital-acquired infections (HAI) contribute to the emotional stress and functional disorders of the patient and in some cases, can lead to a state of disability that reduces quality of life. Often, HAI are one of the factors that lead to death. The purpose of this study was to analyze the cases of HAI identified in public hospitals at the county level, through case report sheets, as they are reported according to the Romanian legislation. Methods: We performed a cross sectional study design based on the case law of the data reported to the Mures Public Health Directorate, by all the public hospitals belonging to this county. We tracked hospital-acquired infections reported for 2017–2018, respectively, a number of 1024 cases, which implies a prevalence rate of 0.44%, 1024/228,782 cases discharged from these hospitals during the studied period. Results: The most frequent HAIs were reported by the intensive care units (48.4%), the most common infections being the following: bronchopneumonia (25.3%), enterocolitis with Clostridioides difficile (23.3%), sepsis, surgical wound infections and urinary tract infections. At the basis of HAI were 22 pathogens, but the five most common germs were Clostridioides difficile, Acinetobacter baumannii, Klebsiella pneumoniae, Pseudomonas aeruginosa and Staphylococcus aureus. Bronchopneumonia have been most frequently reported in intensive care units, the most common being identified the Acinetobacter baumannii agent. Sepsis and central catheter infections also appeared predominantly in intensive care units, more often with Klebsiella pneumoniae. The enterocolitis with Clostridioides difficile, were the apanage of the medical sections. Infections with Staphylococcus aureus have been identified predominantly in the surgical sections at the level of the surgical wounds. Urinary infections had a similar distribution in the intensive care units, the medical and surgical sections, with Klebsiella pneumoniae being the most commonly incriminated agent. Conclusions: We showed a clear correspondence between the medical units and the type of HAI: what recommends the rapid, vigilant and oriented application of the prevention and control strategies of the HAI.


2019 ◽  
Vol 10 ◽  
Author(s):  
Clara Cosgaya ◽  
Carlos Ratia ◽  
Marta Marí-Almirall ◽  
Laia Rubio ◽  
Paul G. Higgins ◽  
...  

2016 ◽  
Vol 2016 ◽  
pp. 1-5 ◽  
Author(s):  
Zihe Yan ◽  
Junjun Yang ◽  
Renjing Hu ◽  
Xichi Hu ◽  
Kong Chen

Acinetobacter baumanniiis a significant cause of severe hospital-acquired infections with a recent rise in multidrug-resistant infections involving traumatic wounds of military personnel. The interleukin-17 (IL-17) pathway is essential for neutrophil recruitment in response to a variety of pathogens, while the control ofA. baumanniiinfection is known to be dependent on neutrophils. This suggests that IL-17 may play an important role inA. baumanniiinfection; however, this has yet to be studied. Here, we summarize the recent advances in understanding the host-pathogen interaction ofA. baumanniiand propose a potential role of the IL-17 pathway in generating a protective immune response.


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