Prevalence of Carbapenemase Genes, qacE, qacEΔ1 and cepA in Multidrug-Resistant Gram-Negative Bacteria with Different Susceptibility to Chlorhexidine

2020 ◽  
Vol 19 (5) ◽  
pp. 49-60
Author(s):  
K. G. Kosyakova ◽  
N. B. Esaulenko ◽  
O. A. Kameneva ◽  
S. P. Kazakov ◽  
A. Y. Dubinina ◽  
...  

Relevance The World Health Organization has provided a list of resistant bacteria that pose the greatest threat to society. Among them, the most important (critically high priority level) are Pseudomonas aeruginosa and Acinetobacter baumannii strains resistant to carbapenems, as well as enterobacteriaceae producing extended spectrum beta-lactamases and carbapenemases.Aim. To conduct a comparative analysis of the sensitivity to chlorhexidine of multiply-resistant gram-negative bacteria, the causative agents of infectious conditions in patients of various medical organizations, and to study the relationship between the presence of resistance genes and the minimum inhibitory concentration of chlorhexidine.Materials & methods. The study included 138 Gram-negative multidrug-resistant strains isolated during 2018–2019 from various clinical specimens. Susceptibility of the isolates to antibiotics were determined using Vitek-2 compact and Phoenix М50, susceptibility to chlorhexidine were determined by agar dilution method. The resistance genes were detected by the real-time PCR method.Results. The lowest level of resistance to chlorhexidine was determined in E. coli strains (MIC90 16 mg/l), other strains were highly resistant: MIC90 of P. aeruginosa and A. baumannii – 128 mg/l, K. pneumoniae, E. cloacae и P. mirabilis – 256 mg/l. The highest frequency of detection of carbapenemase genes observed in K. pneumoniae strains – 56.0% and P. aeruginosa – 48.1%. High prevalence of cepA gene was found out (the strains of enterobacteria – 47.8%, A. baumannii – 42.9%), genes qacE, qacEΔ1 were more often detected in non-fermenting Gram-negative bacteria then in enterobacteria. Conclusion. According to the results of our study, we did not reveal a significant correlation between the presence or absence of resistance genes and MIC of chlorhexidine in Gram-negative bacteria. However, taking into account complex mechanism of the adaptive response of bacteria to the effects of chlorhexidine, and to implement the concept of preventing health care-associated infections, it is proposed to continue dynamic monitoring of the resistance of microorganisms to antiseptics, disinfectants and antibiotics.

2016 ◽  
Vol 82 (12) ◽  
pp. 3605-3610 ◽  
Author(s):  
Andreas F. Wendel ◽  
Sofija Ressina ◽  
Susanne Kolbe-Busch ◽  
Klaus Pfeffer ◽  
Colin R. MacKenzie

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.


2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Edgarthe Priscilla Ngaiganam ◽  
Isabelle Pagnier ◽  
Wafaa Chaalal ◽  
Thongpan Leangapichart ◽  
Selma Chabou ◽  
...  

Abstract Background We investigate here the presence of multidrug-resistant bacteria isolated from stool samples of yellow-legged gulls and chickens (n = 136) in urban parks and beaches of Marseille, France. Bacterial isolation was performed on selective media, including MacConkey agar with ceftriaxone and LBJMR medium. Antibiotic resistance genes, including extended-spectrum β-lactamases (ESBL) (i.e. blaCTX-M, blaTEM and blaSHV), carbapenemases (blaKPC, blaVIM, blaNDM, blaOXA-23, blaOXA-24, blaOXA-48 and blaOXA-58) and colistin resistance genes (mcr-1 to mcr-5) were screened by real-time PCR and standard PCR and sequenced when found. Results Of the 136 stools samples collected, seven ESBL-producing Gram-negative bacteria (BGN) and 12 colistin-resistant Enterobacteriaceae were isolated. Among them, five ESBL-producing Escherichia coli and eight colistin-resistant Hafnia alvei strains were identified. Four blaTEM-1 genes were detected in yellow-legged gulls and chickens. Three CTX-M-15 genes were detected in yellow-legged gulls and pigeons, and one CTX-M-1 in a yellow-legged gull. No mcr-1 to mcr-5 gene were detected in colistin-resistant isolates. Genotyping of E. coli strains revealed four different sequence types already described in humans and animals and one new sequence type. Conclusions Urban birds, which are believed to have no contact with antibiotics appear as potential source of ESBL genes. Our findings highlight the important role of urban birds in the proliferation of multidrug-resistant bacteria and also the possible zoonotic transmission of such bacteria from wild birds to humans.


Molecules ◽  
2019 ◽  
Vol 24 (17) ◽  
pp. 3152 ◽  
Author(s):  
Raphaël E. Duval ◽  
Marion Grare ◽  
Béatrice Demoré

Antimicrobial resistance in bacteria is frightening, especially resistance in Gram-negative Bacteria (GNB). In 2017, the World Health Organization (WHO) published a list of 12 bacteria that represent a threat to human health, and among these, a majority of GNB. Antibiotic resistance is a complex and relatively old phenomenon that is the consequence of several factors. The first factor is the vertiginous drop in research and development of new antibacterials. In fact, many companies simply stop this R&D activity. The finding is simple: there are enough antibiotics to treat the different types of infection that clinicians face. The second factor is the appearance and spread of resistant or even multidrug-resistant bacteria. For a long time, this situation remained rather confidential, almost anecdotal. It was not until the end of the 1980s that awareness emerged. It was the time of Vancomycin-Resistance Enterococci (VRE), and the threat of Vancomycin-Resistant MRSA (Methicillin-Resistant Staphylococcus aureus). After this, there has been renewed interest but only in anti-Gram positive antibacterials. Today, the threat is GNB, and we have no new molecules with innovative mechanism of action to fight effectively against these bugs. However, the war against antimicrobial resistance is not lost. We must continue the fight, which requires a better knowledge of the mechanisms of action of anti-infectious agents and concomitantly the mechanisms of resistance of infectious agents.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S314-S315
Author(s):  
Alejandro Iregui ◽  
Zeb Khan ◽  
David Landman ◽  
John M Quale

Abstract Background Carbapenem-resistant Gram-negative bacteria are important nosocomial pathogens, and therapeutic options are often limited. Methods Clinical isolates were gathered during a surveillance study in 2017 involving 7 hospitals in Brooklyn, NY. Isolates underwent susceptibility testing using the agar dilution method; for the combination of imipenem-relebactam and ceftolozane-tazobactam, the concentrations of relebactam and tazobactam were fixed at 4 µg/mL. Breakpoints were defined according to CLSI criteria; for imipenem-relebactam, the breakpoint of imipenem was utilized. Isolates were screened by PCR for common carbapenemases. Results Overall susceptibility patterns are given in the Table. Of 1805 isolates of E. coli (including 4 with blaKPC), 100% were susceptible to imipenem and imipenem-relebactam. Of 503 isolates of K. pneumoniae (including 19 isolates with blaKPC), all were susceptible to imipenem-relebactam. Of 171 isolates of Enterobacter spp. (including 3 with blaKPC), 100% were susceptible to imipenem-relebactam. Of 260 isolates of P. aeruginosa, 96% were susceptible to imipenem-relebactam and nearly all to ceftolozane-tazobactam. Against A. baumannii, the activity of imipenem-relebactam was the same as imipenem and the ceftolozane-tazobactam MIC was ≤ 4 µg/mL in 65% of isolates. Conclusion Imipenem-relebactam possesses promising activity against multidrug-resistant Enterobacteriaceae endemic to New York City. Ceftolozane-tazobactam demonstrated excellent activity against P. aeruginosa, including isolates resistant to carbapenems. Disclosures All authors: No reported disclosures.


Nanomaterials ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 312
Author(s):  
Mohammad Okkeh ◽  
Nora Bloise ◽  
Elisa Restivo ◽  
Lorenzo De Vita ◽  
Piersandro Pallavicini ◽  
...  

In 2017 the World Health Organization (WHO) announced a list of the 12 multidrug-resistant (MDR) families of bacteria that pose the greatest threat to human health, and recommended that new measures should be taken to promote the development of new therapies against these superbugs. Few antibiotics have been developed in the last two decades. Part of this slow progression can be attributed to the surge in the resistance acquired by bacteria, which is holding back pharma companies from taking the risk to invest in new antibiotic entities. With limited antibiotic options and an escalating bacterial resistance there is an urgent need to explore alternative ways of meeting this global challenge. The field of medical nanotechnology has emerged as an innovative and a powerful tool for treating some of the most complicated health conditions. Different inorganic nanomaterials including gold, silver, and others have showed potential antibacterial efficacies. Interestingly, gold nanoparticles (AuNPs) have gained specific attention, due to their biocompatibility, ease of surface functionalization, and their optical properties. In this review, we will focus on the latest research, done in the field of antibacterial gold nanoparticles; by discussing the mechanisms of action, antibacterial efficacies, and future implementations of these innovative antibacterial systems.


2019 ◽  
Vol 116 (43) ◽  
pp. 21748-21757 ◽  
Author(s):  
Elizabeth M. Hart ◽  
Angela M. Mitchell ◽  
Anna Konovalova ◽  
Marcin Grabowicz ◽  
Jessica Sheng ◽  
...  

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.


2020 ◽  
Vol 8 (9) ◽  
pp. 1425
Author(s):  
Lara Pérez-Etayo ◽  
David González ◽  
José Leiva ◽  
Ana Isabel Vitas

Due to the global progress of antimicrobial resistance, the World Health Organization (WHO) published the list of the antibiotic-resistant “priority pathogens” in order to promote research and development of new antibiotics to the families of bacteria that cause severe and often deadly infections. In the framework of the One Health approach, the surveillance of these pathogens in different environments should be implemented in order to analyze their spread and the potential risk of transmission of antibiotic resistances by food and water. Therefore, the objective of this work was to determine the presence of high and critical priority pathogens included in the aforementioned list in different aquatic environments in the POCTEFA area (North Spain–South France). In addition to these pathogens, detection of colistin-resistant Enterobacteriaceae was included due its relevance as being the antibiotic of choice to treat infections caused by multidrug resistant bacteria (MDR). From the total of 80 analyzed samples, 100% of the wastewater treatment plants (WWTPs) and collectors (from hospitals and slaughterhouses) and 96.4% of the rivers, carried antibiotic resistant bacteria (ARB) against the tested antibiotics. Fifty-five (17.7%) of the isolates were identified as target microorganisms (high and critical priority pathogens of WHO list) and 58.2% (n = 32) of them came from WWTPs and collectors. Phenotypic and genotypic characterization showed that 96.4% were MDR and resistance to penicillins/cephalosporins was the most widespread. The presence of bla genes, KPC-type carbapenemases, mcr-1 and vanB genes has been confirmed. In summary, the presence of clinically relevant MDR bacteria in the studied aquatic environments demonstrates the need to improve surveillance and treatments of wastewaters from slaughterhouses, hospitals and WWTPs, in order to minimize the dispersion of resistance through the effluents of these areas.


2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S288-S288
Author(s):  
Tafese B Tufa ◽  
Fuchs André ◽  
Sileshi Abdissa ◽  
Zewdu Hurissa ◽  
Hans Martin Orth ◽  
...  

Abstract Background Acute infectious diseases and sepsis are among the leading causes of mortality in Ethiopia. The lack of local data concerning causative pathogens and resistance patterns results in suboptimal empirical treatment and unfavorable clinical outcome. The objective of this study was the characterization of bacterial pathogens in hospitalized patients with febrile infections in Central Ethiopia. Methods In total, 684 patients ≥1 year of age with fever admitted to the Asella Teaching Hospital from April 2016 to June 2018 were included. Blood and other appropriate clinical specimens were cultured. Susceptibility testing was performed using the Kirby–Bauer method and VITEK2. Confirmation of species identification and identification of resistance genes were conducted using MALDI-ToF and PCR at a microbiology laboratory in Düsseldorf, Germany. Results In total, 684 study participants were included; 54% were male and mean age was 26.7 years. Thus, the overall culture positivity rate was 7.5%. Of the 83 cultured organisms, 38(46%) were Gram-negative, 43(52%) Gram-positive, and 2(2%) Candida species. Among the 38 Gram-negative isolates, 16(42%) were E. coli, 15(39%) K. pneumoniae, and 4(11%) P. aeruginosa. Resistance against commonly used antibiotics for Gram-negative at the study site was: piperacillin/tazobactam 48%(13), ampicillin/sulbactam 93% (25), cefotaxime 89%(24), ceftazidime 74%(20), Cefipime 74%(20), meropenem 7%(2), amikacin 4% (1) and gentamicin 56%(15). Of 27 Gram-negative available for resistance-gene detection, blaNDM-1 was detected in one K. pneumoniae isolate and blaNDM-1 plus blaOXA-51 in A. baumannii. 81%(22/27) of the Gram-negative rods were confirmed to contain ESBL-genes as follows: TEM 17(77%), CTX-M-1-group 15(68%), SHV-6(27%) and CTX-M-9-group 2(9%). Among isolated S.aureus, 1(5%) was confirmed to be Methicillin-resistant S. aureus. Conclusion We found a high prevalence (81%) of ESBL-producing bacteria and 7.4% carbapenem resistance at the study site. More than half of Gram-negative isolates had two or more mobile resistance genes. These findings warrant the need for local national multidrug-resistant surveillance. Strengthening of antimicrobial stewardship programs is needed in order to face the threat of multidrug-resistant bacteria. Disclosures All authors: No reported disclosures.


2015 ◽  
Vol 9 (01) ◽  
pp. 029-034 ◽  
Author(s):  
Thiago César Nascimento ◽  
Vânia Lúcia Da Silva ◽  
Alessandra Barbosa Ferreira-Machado ◽  
Cláudio Galuppo Diniz

Introduction: Healthcare waste (HCW) might potentially harbor infective viable microorganisms in sanitary landfills. We investigated the antimicrobial susceptibility patterns and the occurrence of the mecA gene in coagulase-negative Staphylococcus strains (CoNS) recovered from the leachate of the HCW in an untreated sanitary landfill. Methodology: Bacterial identification was performed by physiological and molecular approaches, and minimum inhibitory concentrations (MICs) of antimicrobial drugs were determined by the agar dilution method according to CLSI guidelines. All oxacillin-resistant bacteria were screened for the mecA gene. Results: Out of 73 CoNS, seven different species were identified by 16S rDNA sequencing: Staphylococcus felis (64.4%; n = 47), Staphylococcus sciuri (26.0%; n = 19), Staphylococcus epidermidis (2.7%; n = 2), Staphylococcus warneri (2.7%; n = 2), Staphylococcus lentus (1.4%; n = 1), Staphylococcus saprophyticus (1.4%; n = 1), and Staphylococcus haemolyticus (1.4%; n = 1). Penicillin was the least effective antimicrobial (60.3% of resistance; n = 44) followed by erythromycin (39.8%; n = 29), azithromycin (28.8%; n = 21), and oxacillin (16.5%; n = 12). The most effective drug was vancomycin, for which no resistance was observed, followed by gentamicin and levofloxacin, for which only intermediate resistance was observed (22%, n = 16 and 1.4%, n = 1, respectively). Among the oxacillin-resistant strains, the mecA gene was detected in two isolates. Conclusions: Considering the high antimicrobial resistance observed, our results raise concerns about the survival of putative bacterial pathogens carrying important resistance markers in HCW and their environmental spread through untreated residues discharged in sanitary landfills.


2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Alessandro Delli Paoli Carini ◽  
Ellen Ariel ◽  
Jacqueline Picard ◽  
Lisa Elliott

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.


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