scholarly journals Targeted Molecular Detection of Nosocomial Carbapenemase-Producing Gram-Negative Bacteria—On Near- and Distant-Patient Surfaces

2021 ◽  
Vol 9 (6) ◽  
pp. 1190
Author(s):  
Claudia Stein ◽  
Isabel Lange ◽  
Jürgen Rödel ◽  
Mathias W. Pletz ◽  
Frank Kipp
Keyword(s):  
Multidrug Resistant ◽  
Mean Value ◽  
Resistant Bacteria ◽  
Screening Methods ◽  
Gram Negative Bacteria ◽  
Bacterial Dna ◽  
Gram Negative ◽  
Integrative Method ◽  
Cleaning And Disinfection ◽  
Positive Results

Background: Here, we describe an integrative method to detect carbapenemase-producing Gram-negative bacteria (gn-Cp) on surfaces/fomites in the patient environment. We examined environmental samples from 28 patient rooms occupied with patients who were proven to be colonised with gn-Cp by rectal screening. Methods: We took samples after 24 h, 72 h and one week. For sampling, we divided the patient environment into four parts and took samples from near- and extended patient areas. To obtain a representative bacterial swab from a larger surface, such as the patient cabinet, we used Polywipes. Bacterial DNA was isolated. Carbapenemase was detected with specific qPCR primers. Results: With this culture- and molecular-based approach, we could control the effectiveness of cleaning and disinfection in everyday clinical practice. Therefore, we could track the spread of gn-Cp within the patient room. The number of positive detections fluctuated between 30.5% (mean value positive results after 72 h) and 35.2% (after 24 h and one week). Conclusion: The method used to detect multidrug-resistant bacteria in the environment of patients by using PolywipesTM is reliable and can therefore be used as an effective, new tool in hygiene and infection control.

scholarly journals A small-molecule inhibitor of BamA impervious to efflux and the outer membrane permeability barrier

2019 ◽  
Vol 116 (43) ◽  
pp. 21748-21757 ◽  
Author(s):  
Elizabeth M. Hart ◽  
Angela M. Mitchell ◽  
Anna Konovalova ◽  
Marcin Grabowicz ◽  
Jessica Sheng ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Small Molecule ◽  
Cytoplasmic Membrane ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Permeability Barrier ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Bam Complex ◽  
Induced Aggregation

The development of new antimicrobial drugs is a priority to combat the increasing spread of multidrug-resistant bacteria. This development is especially problematic in gram-negative bacteria due to the outer membrane (OM) permeability barrier and multidrug efflux pumps. Therefore, we screened for compounds that target essential, nonredundant, surface-exposed processes in gram-negative bacteria. We identified a compound, MRL-494, that inhibits assembly of OM proteins (OMPs) by the β-barrel assembly machine (BAM complex). The BAM complex contains one essential surface-exposed protein, BamA. We constructed a bamA mutagenesis library, screened for resistance to MRL-494, and identified the mutation bamAE470K. BamAE470K restores OMP biogenesis in the presence of MRL-494. The mutant protein has both altered conformation and activity, suggesting it could either inhibit MRL-494 binding or allow BamA to function in the presence of MRL-494. By cellular thermal shift assay (CETSA), we determined that MRL-494 stabilizes BamA and BamAE470K from thermally induced aggregation, indicating direct or proximal binding to both BamA and BamAE470K. Thus, it is the altered activity of BamAE470K responsible for resistance to MRL-494. Strikingly, MRL-494 possesses a second mechanism of action that kills gram-positive organisms. In microbes lacking an OM, MRL-494 lethally disrupts the cytoplasmic membrane. We suggest that the compound cannot disrupt the cytoplasmic membrane of gram-negative bacteria because it cannot penetrate the OM. Instead, MRL-494 inhibits OMP biogenesis from outside the OM by targeting BamA. The identification of a small molecule that inhibits OMP biogenesis at the cell surface represents a distinct class of antibacterial agents.

scholarly journals Species Diversity of Environmental GIM-1-Producing Bacteria Collected during a Long-Term Outbreak

2016 ◽  
Vol 82 (12) ◽  
pp. 3605-3610 ◽  
Author(s):  
Andreas F. Wendel ◽  
Sofija Ressina ◽  
Susanne Kolbe-Busch ◽  
Klaus Pfeffer ◽  
Colin R. MacKenzie
Keyword(s):  
Resistance Genes ◽  
Multidrug Resistant ◽  
Hospital Environment ◽  
Resistant Bacteria ◽  
Environmental Sampling ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Negative ◽  
Content Type

ABSTRACTReports of outbreaks concerning carbapenemase-producing Gram-negative bacteria in which the main source of transmission is the hospital environment are increasing. This study describes the results of environmental sampling in a protracted polyspecies metallo-beta-lactamase GIM-1 outbreak driven by plasmids and bacterial clones ofEnterobacter cloacaeandPseudomonas aeruginosain a tertiary care center. Environmental sampling targeting wet locations (especially sinks) was carried out on a surgical intensive care unit and on a medical ward on several occasions in 2012 and 2013. We were able to demonstrate 43blaGIM-1-carrying bacteria (mainly nonfermenters but alsoEnterobacteriaceae) that were either related or unrelated to clinical strains in 30 sinks and one hair washbasin. GIM-1 was found in 12 different species, some of which are described here as carriers of GIM-1. Forty out of 43 bacteria displayed resistance to carbapenems and, in addition, to various non-beta-lactam antibiotics. Colistin resistance was observed in twoE. cloacaeisolates with MICs above 256 mg/liter. TheblaGIM-1gene was harbored in 12 different class 1 integrons, some without the typical 3′ end. TheblaGIM-1gene was localized on plasmids in five isolates.In vitroplasmid transfer by conjugation was successful in one isolate. The environment, with putatively multispecies biofilms, seems to be an important biological niche for multidrug-resistant bacteria and resistance genes. Biofilms may serve as a “melting pot” for horizontal gene transfer, for dissemination into new species, and as a reservoir to propagate future hospital outbreaks.IMPORTANCEIn Gram-negative bacteria, resistance to the clinically relevant broad-spectrum carbapenem antibiotics is a major public health concern. Major reservoirs for these resistant organisms are not only the gastrointestinal tracts of animals and humans but also the (hospital) environment. Due to the difficulty in eradicating biofilm formation in the latter, a sustained dissemination of multidrug-resistant bacteria from the environment can occur. In addition, horizontal transfer of resistance genes on mobile genetic elements within biofilms adds to the total “resistance gene pool” in the environment. To gain insight into the transmission pathways of a rare and locally restricted carbapenemases resistance gene (blaGIM-1), we analyzed the genetic background of theblaGIM-1gene in environmental bacteria during a long-term polyspecies outbreak in a German hospital.

scholarly journals Antibiotic Resistant Bacterial Isolates from Captive Green Turtles andIn VitroSensitivity to Bacteriophages

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alessandro Delli Paoli Carini ◽  
Ellen Ariel ◽  
Jacqueline Picard ◽  
Lisa Elliott
Keyword(s):  
Rapid Evolution ◽  
Chelonia Mydas ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Green Turtles ◽  
Resistant Genes ◽  
Resistance Rates

This study aimed to test multidrug resistant isolates from hospitalised green turtles(Chelonia mydas)and their environment in North Queensland, Australia, forin vitrosusceptibility to bacteriophages. Seventy-one Gram-negative bacteria were isolated from green turtle eye swabs and water samples. Broth microdilution tests were used to determine antibiotic susceptibility. All isolates were resistant to at least two antibiotics, with 24% being resistant to seven of the eight antibiotics. Highest resistance rates were detected to enrofloxacin (77%) and ampicillin (69.2%). More than 50% resistance was also found to amoxicillin/clavulanic acid (62.5%), ceftiofur (53.8%), and erythromycin (53.3%). All the enriched phage filtrate mixtures resulted in the lysis of one or more of the multidrug resistant bacteria, includingVibrio harveyiandV. parahaemolyticus. These results indicate that antibiotic resistance is common in Gram-negative bacteria isolated from hospitalised sea turtles and their marine environment in North Queensland, supporting global concern over the rapid evolution of multidrug resistant genes in the environment. Using virulent bacteriophages as antibiotic alternatives would not only be beneficial to turtle health but also prevent further addition of multidrug resistant genes to coastal waters.

scholarly journals Trends of Bloodstream Infections in a University Greek Hospital during a Three-Year Period: Incidence of Multidrug-Resistant Bacteria and Seasonality in Gram-negative Predominance

2017 ◽  
Vol 66 (2) ◽  
pp. 171-180 ◽  
Author(s):  
Fevronia Kolonitsiou ◽  
Matthaios Papadimitriou-Olivgeris ◽  
Anastasia Spiliopoulou ◽  
Vasiliki Stamouli ◽  
Vasileios Papakostas ◽  
...  
Keyword(s):  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Blood Cultures ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Carbapenem Resistant

The aim of the study was to assess the epidemiology, the incidence of multidrug-resistant bacteria and bloodstream infections’ (BSIs) seasonality in a university hospital. This retrospective study was carried out in the University General Hospital of Patras, Greece, during 2011–13 y. Blood cultures from patients with clinical presentation suggestive of bloodstream infection were performed by the BacT/ALERT System. Isolates were identified by Vitek 2 Advanced Expert System. Antibiotic susceptibility testing was performed by the disk diffusion method and E-test. Resistance genes (mecA in staphylococci; vanA/vanB/vanC in enterococci; blaKPC/blaVIM/blaNDM in Klebsiella spp.) were detected by PCR. In total, 4607 (9.7%) blood cultures were positive from 47451 sets sent to Department of Microbiology, representing 1732 BSIs. Gram-negative bacteria (52.3%) were the most commonly isolated, followed by Gram-positive (39.5%), fungi (6.6%) and anaerobes bacteria (1.8%). The highest contamination rate was observed among Gram-positive bacteria (42.3%). Among 330 CNS and 150 Staphylococcus aureus, 281 (85.2%) and 60 (40.0%) were mecA-positive, respectively. From 113 enterococci, eight were vanA, two vanB and two vanC-positives. Of the total 207 carbapenem-resistant Klebsiella pneumoniae (73.4%), 202 carried blaKPC, four blaKPC and blaVIM and one blaVIM. A significant increase in monthly BSIs’ incidence was shown (R2: 0.449), which may be attributed to a rise of Gram-positive BSIs (R2: 0.337). Gram-positive BSIs were less frequent in spring (P < 0.001), summer (P < 0.001), and autumn (P < 0.001), as compared to winter months, while Gram-negative bacteria (P < 0.001) and fungi (P < 0.001) were more frequent in summer months. BSIs due to methicillin resistant S. aureus and carbapenem-resistant Gram-negative bacteria increased during the study period. The increasing incidence of BSIs can be attributed to an increase of Gram-positive BSI incidence, even though Gram-negative bacteria remained the predominant ones. Seasonality may play a role in the predominance of Gram-negative’s BSI.

scholarly journals Antimicrobial Resistance in Hospitalized Surgical Patients: a Silently Emerging Public Health Concern in Benin.

2020 ◽  
Author(s):  
Carine Laurence YEHOUENOU ◽  
Arsène A. KPANGON ◽  
Dissou AFFOLABI ◽  
Hector RODRIGUEZ-VILLALOBOS ◽  
Françoise Van Bambeke ◽  
...  
Keyword(s):  
Gastrointestinal Surgery ◽  
Surgical Site Infections ◽  
Multidrug Resistant ◽  
Public Hospitals ◽  
Health Concern ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Strict Adherence ◽  
Gram Negative

Abstract Background: Surgical site infections are related to high morbidity, mortality and healthcare costs. As the emergence of multidrug-resistant bacterial pathogens in hospitals is becoming a worldwide challenge for surgeons who treat healthcare-associated infections, we wished to identify the causative agents involved in surgical site infections and their susceptibility pattern in six public hospitals in Benin. Methods: Using standard microbiological procedures, we processed pus specimens collected from obstetrics and gastrointestinal surgery wards. Mass spectrometry (MALDI-TOF) was used for confirmation. The antibiotic susceptibility test firstly used the Kirby-Bauer disc diffusion method. The secondary test by microdilution used the Beckton Dickinson Phoenix automated system (Becton Dickinson Diagnostic, USA). Results: We included 304 patients (mean age 32 ± 11 years), whose median length of stay was 9 days. A total of 259 wound swabs (85.2%) had positive aerobic bacterial growth. In obstetrics S. aureus (28.5%, n=42) was the most common isolate. In contrast, Gram-negative bacteria (GNB) were predominant in gastrointestinal surgery. The most dominant being E.coli (38.4%, n=31). Overall, 90.8% (n=208) of aerobic bacteria were multidrug resistant. Two-third of S. aureus (65.3%, n= 32) were methicillin-resistant Staphylococcus aureus (MRSA), three of which carried both MRSA and induced clindamycin resistance (ICR). GNB showed high resistance to ceftazidime, ceftriaxone and cefepime. Extended-spectrum beta-lactamases were presented by 69.4% of E.coli (n=43/62) and 83.3% of K. pneumoniae (n=25/30). Overall, twelve Gram negative bacteria (5.24%) isolates showed resistance to at least one carbapenem. No isolates showed a wild-type susceptible phenotype.Conclusion: This study shows the alarming prevalence of multidrug resistant organisms from surgical site infections in Benin hospitals. To reduce the spread of these multidrug-resistant bacteria, periodic surveillance of surgical site infections and strict adherence to good hand-hygiene practice are essential.

scholarly journals Detection of Multidrug Resistant Gram Negative Bacteria in Healthy Cattle from Maiduguri Metropolitan, Nigeria

2020 ◽  
pp. 68-76
Author(s):  
Adam Mustapha ◽  
Mustafa Alhaji Isa ◽  
Ibrahim Yusuf Ngoshe ◽  
Hashidu Bala
Keyword(s):  
Antibiotic Resistance ◽  
Clinical Laboratory ◽  
Resistance Index ◽  
Multidrug Resistant ◽  
Diffusion Method ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Salmonella Spp ◽  
Gram Negative ◽  
Healthy Cattle

Aim: Prevalence of multidrug resistant bacteria on apparently health animals has turned antibiotic resistance to multifaceted process and threatens global food security and public health. The aim of the present study was to investigate the resistance profile of isolates from apparently healthy cattle in Maiduguri, Nigeria. Methodology: A total of 120 nasal swab samples were collected from cattle. Colony identification was according to the guidelines of Bergey’s Manual of Determinative Bacteriology. The susceptibility pattern of the isolates was conducted on the identified isolates according to the Modified Kirby-Baur disc diffusion method on Muller-Hilton agar and interpreted according to the procedures of Clinical Laboratory Standards Institute (CLSI, 2018) guidelines. Multiple Antibiotic Resistance Index (MARI) was calculated using the formula, MARI=a/b where “a” is the number of antibiotic resisted and “b” is the total number of antibiotic used in the study. Results: Of the total samples (120) from cattle 96 (80%) detected the following isolates; E. coli was the most commonly recovered isolates (33, 34.4%), followed by Klebsiella spp (28, 29.2%), Salmonella spp (21, 21.9%) and Pseudomonas aeruginosa (14, 14.5%). In this study, all the recovered isolates were found to be multidrug resistant gram negative bacteria, with highest resistance was shown by Salmonella spp. The high MARI observed in all the isolates in this study ranging from 0.7 to 0.9. MARI value of 0.2 > is suggests multiple antibiotic resistant bacteria and indicate presence of highly resistant bacteria. Conclusion: The study indicates highly resistant bacteria are carried by healthy food animals. Thus, there is need for continued monitoring of antibiotics use in animal husbandry to prevent further spread of resistance in Maiduguri, Nigeria.

Oral, nasopharyngeal, and gut decontamination in the ICU

2016 ◽  
Author(s):  
Evelien Oostdijk ◽  
Marc Bonten
Keyword(s):  
Digestive Tract ◽  
Antibiotic Use ◽  
Multidrug Resistant ◽  
Selective Decontamination ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Detailed Data ◽  
Multidrug Resistant Bacteria ◽  
Gram Negative ◽  
Selective Oropharyngeal Decontamination

Many infections are caused by enteric bacilli, presumably from endogenous origin. Selective decontamination of the digestive tract (SDD) was developed to selectively eliminate the aerobic Gram-negative bacilli from the digestive tract, leaving the anaerobic flora unaffected. As an alternative to SDD, investigators have evaluated the effects of selective oropharyngeal decontamination (SOpD) alone. Most detailed data on the effects of SDD and SOpD in ICU-patients come from two studies performed in Dutch ICUs. The Dutch studies provide strong evidence that SDD and SOpD reduce ICUmortality, ICU-acquired bacteraemia with Gram-negative bacteria, and systemic antibiotic use. Although successful application has been reported from several solitary ICUs across Europe, it is currently unknown to what extent these effects can be achieved in settings with different bacterial ecology. More studies are needed on the use of SDD or SOpD as a measure to control outbreaks with multidrug resistant bacteria.

scholarly journals Bacteriocins, Antimicrobial Peptides from Bacterial Origin: Overview of Their Biology and Their Impact against Multidrug-Resistant Bacteria

2020 ◽  
Vol 8 (5) ◽  
pp. 639 ◽  
Author(s):  
Alexis Simons ◽  
Kamel Alhanout ◽  
Raphaël E. Duval
Keyword(s):  
Antimicrobial Resistance ◽  
Bacterial Infections ◽  
Antimicrobial Agents ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Multidrug Resistant Bacteria ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Further Development

Currently, the emergence and ongoing dissemination of antimicrobial resistance among bacteria are critical health and economic issue, leading to increased rates of morbidity and mortality related to bacterial infections. Research and development for new antimicrobial agents is currently needed to overcome this problem. Among the different approaches studied, bacteriocins seem to be a promising possibility. These molecules are peptides naturally synthesized by ribosomes, produced by both Gram-positive bacteria (GPB) and Gram-negative bacteria (GNB), which will allow these bacteriocin producers to survive in highly competitive polymicrobial environment. Bacteriocins exhibit antimicrobial activity with variable spectrum depending on the peptide, which may target several bacteria. Already used in some areas such as agro-food, bacteriocins may be considered as interesting candidates for further development as antimicrobial agents used in health contexts, particularly considering the issue of antimicrobial resistance. The aim of this review is to present an updated global report on the biology of bacteriocins produced by GPB and GNB, as well as their antibacterial activity against relevant bacterial pathogens, and especially against multidrug-resistant bacteria.

scholarly journals Synergistic Effect of Propidium Iodide and Small Molecule Antibiotics with the Antimicrobial Peptide Dendrimer G3KL against Gram-Negative Bacteria

Molecules ◽  
2020 ◽  
Vol 25 (23) ◽  
pp. 5643
Author(s):  
Bee-Ha Gan ◽  
Xingguang Cai ◽  
Sacha Javor ◽  
Thilo Köhler ◽  
Jean-Louis Reymond
Keyword(s):  
Synergistic Effect ◽  
Propidium Iodide ◽  
Synergistic Effects ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Bacterial Killing ◽  
Gram Negative ◽  
Outer Membranes ◽  
New Antibiotics

There is an urgent need to develop new antibiotics against multidrug-resistant bacteria. Many antimicrobial peptides (AMPs) are active against such bacteria and often act by destabilizing membranes, a mechanism that can also be used to permeabilize bacteria to other antibiotics, resulting in synergistic effects. We recently showed that G3KL, an AMP with a multibranched dendritic topology of the peptide chain, permeabilizes the inner and outer membranes of Gram-negative bacteria including multidrug-resistant strains, leading to efficient bacterial killing. Here, we show that permeabilization of the outer and inner membranes of Pseudomonas aeruginosa by G3KL, initially detected using the DNA-binding fluorogenic dye propidium iodide (PI), also leads to a synergistic effect between G3KL and PI in this bacterium. We also identify a synergistic effect between G3KL and six different antibiotics against the Gram-negative Klebsiella pneumoniae, against which G3KL is inactive.

Evaluation of Potential Environmental Contamination Sources for the Presence of Multidrug-Resistant Bacteria Linked to Wound Infections in Combat Casualties

2012 ◽  
Vol 33 (9) ◽  
pp. 905-911 ◽  
Author(s):  
Edward F. Keen ◽  
Katrin Mende ◽  
Heather C. Yun ◽  
Wade K. Aldous ◽  
Timothy E. Wallum ◽  
...  
Keyword(s):  
Surgical Procedures ◽  
Bacterial Contamination ◽  
Micrococcus Luteus ◽  
The United States ◽  
Multidrug Resistant ◽  
Soil Samples ◽  
Resistant Bacteria ◽  
Microbiological Analysis ◽  
Gram Negative Bacteria ◽  
Gram Negative

Objective.To determine whether multidrug-resistant (MDR) gram-negative organisms are present in Afghanistan or Iraq soil samples, contaminate standard deployed hospital or modular operating rooms (ORs), or aerosolize during surgical procedures.Design.Active surveillance.Setting.US military hospitals in the United States, Afghanistan, and Iraq.Methods.Soil samples were collected from sites throughout Afghanistan and Iraq and analyzed for presence of MDR bacteria. Environmental sampling of selected newly established modular and deployed OR high-touch surfaces and equipment was performed to determine the presence of bacterial contamination. Gram-negative bacteria aerosolization during OR surgical procedures was determined by microbiological analysis of settle plate growth.Results.Subsurface soil sample isolates recovered in Afghanistan and Iraq included various pansusceptible members of Enterobacteriaceae, Vibrio species, Pseudomonas species, Acinetobacter Iwojfii, and coagulase-negative Staphylococcus (CNS). OR contamination studies in Afghanistan revealed 1 surface with a Micrococcus luteus. Newly established US-based modular ORs and the colocated fixed-facility ORs revealed no gram-negative bacterial contamination prior to the opening of the modular OR and 5 weeks later. Bacterial aerosolization during surgery in a deployed fixed hospital revealed a mean gram-negative bacteria colony count of 12.8 colony-forming units (CFU)/dm2/h (standard deviation [SD], 17.0) during surgeries and 6.5 CFU/dm2/h (SD, 7.5; P = .14) when the OR was not in use.Conclusion.This study demonstrates no significant gram-negative bacilli colonization of modular and fixed-facility ORs or dirt and no significant aerosolization of these bacilli during surgical procedures. These results lend additional support to the role of nosocomial transmission of MDR pathogens or the colonization of the patient themselves prior to injury.

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