scholarly journals Modern problems of antibiotic resistance gram-negative nosocomial infections in the Rostov region

2019 ◽  
Vol 10 (3) ◽  
pp. 91-96 ◽  
Author(s):  
O. Yu. Kutsevalova ◽  
I. O. Pokudina ◽  
D. A. Rozenko ◽  
D. V. Martynov ◽  
M. Yu. Kaminsky
Keyword(s):  
Resistance Mechanisms ◽  
Infectious Complications ◽  
Control Measures ◽  
Gram Negative Bacteria ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Infection Control Measures ◽  
Test Kit ◽  
Extended Spectrum Beta Lactamases ◽  
The City

Objectives: to analyze the prevalence of strains of gram-negative bacteria - pathogens of infectious complications resistant to carbapenems, including through the production of carbapenemases isolated from various clinical biomaterials in hospitalized patients of hospitals in the city of Rostov-on-Don.Materials and methods: 366 gram-negative bacterial isolates were studied, from patients from 16 wards, 9 treatment-and-prophylactic institutions of the city of Rostov-on-Don and the region. The study was conducted by traditional microbiological method. Species identification of strains and sensitivity to antimicrobial drugs were determined on a Vitek 2 automatic analyzer (BioMerieux, France). The strains insensitive to carbapenems were tested for the presence of carbapenemases using CIM-test. MBL was detected by the effect of suppression of their activity in the presence of EDTA. MBL genes were detected by PCR-RV test kit “AmpliSens MDR MBL-FL”, “AmpliSens MDR KPC/OXA-48-FL”. The conclusion about the production of BLRS was made by the presence of synergism of cephalosporins of III-IV generation with clavulanic acid by the method of double discs.Results: of the 366 isolates tested, gram-negative bacteria accounted for 74.2 %: Klebsiella pneumoniae — 33.0 %, Escherichia coli — 19.0 %, Acinetobacter baumannii — 18.0 %, Pseudomonas aeruginosa — 15.0 %. Resistance to carbapenems was detected in 90.9 % of A.baumannii strains, more than 50 % of P.aeruginosa and K.pneumoniae. LBR production was detected in more than 90 % of K.pneumoniae and about 80 % of E. coli. In A. baumannii and K.pneumoniae isolates, the presence of OXA and NDM genes was found, and in P.aeruginosa, VIM groups.Conclusion: enterobacteria resistant to beta-lactams, producing extended-spectrum beta-lactamases and carbapenemases are one of the leading causative agents of infectious complications in hospitals of Rostov-on-don and the region, almost not inferior in frequency of occurrence of bacteria of the genus Acinetobacter spp. and Paeruginosa. This determines the importance of detection of resistance mechanisms not only for the purpose of optimal etiotropic therapy, but also for epidemiological control of the spread of resistant strains and the development of infection control measures.

Intrinsic, adaptive and acquired antimicrobial resistance in Gram-negative bacteria

2017 ◽  
Vol 61 (1) ◽  
pp. 49-59 ◽  
Author(s):  
Mohsen Arzanlou ◽  
Wern Chern Chai ◽  
Henrietta Venter
Keyword(s):  
Antimicrobial Resistance ◽  
Molecular Mechanisms ◽  
Resistance Mechanisms ◽  
Stress Conditions ◽  
Gram Negative Bacteria ◽  
Mechanisms Of Resistance ◽  
Intrinsic Resistance ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Negative Organisms

Gram-negative bacteria are responsible for a large proportion of antimicrobial-resistant infections in humans and animals. Among this class of bacteria are also some of the most successful environmental organisms. Part of this success is their adaptability to a variety of different niches, their intrinsic resistance to antimicrobial drugs and their ability to rapidly acquire resistance mechanisms. These mechanisms of resistance are not exclusive and the interplay of several mechanisms causes high levels of resistance. In this review, we explore the molecular mechanisms underlying resistance in Gram-negative organisms and how these different mechanisms enable them to survive many different stress conditions.

scholarly journals Genetic Analysis of mcr-1-Carrying Plasmids From Gram-Negative Bacteria in a Dutch Tertiary Care Hospital: Evidence for Intrapatient and Interspecies Transmission Events

2021 ◽  
Vol 12 ◽  
Author(s):  
Nikolaos Strepis ◽  
Anne F. Voor in ’t holt ◽  
Margreet C. Vos ◽  
Willemien H. A. Zandijk ◽  
Astrid P. Heikema ◽  
...  
Keyword(s):  
Medical Center ◽  
Tertiary Care ◽  
Control Measures ◽  
Interspecies Transmission ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Genetic Composition ◽  
Gram Negative ◽  
Infection Control Measures ◽  
Depth Analysis

The role of plasmids in the complex pandemic of antimicrobial resistance is increasingly being recognized. In this respect, multiple mobile colistin resistance (mcr) gene-carrying plasmids have been described. However, the characteristics and epidemiology of these plasmids within local healthcare settings are largely unknown. We retrospectively characterized the genetic composition and epidemiology of plasmids from mcr-1-positive bacterial isolates identified from patients from a large academic hospital in the Netherlands. Clinical Gram-negative bacteria with an MIC > 2 μg/mL for colistin, obtained from patients hospitalized at the Erasmus MC University Medical Center Rotterdam during the years 2010–2018, were screened for presence of the mcr-1 gene. Extracted plasmids from mcr-1-positive isolates were sequenced using a combination of short- and long-read sequencing platforms, characterized by incompatibility type and genetic composition and compared to publicly available mcr-1-carrying plasmid sequences. In 21 isolates from 14 patients, mcr-1 was located on a plasmid. These plasmids were of diverse genetic background involving Inc types IncX4, IncI2(delta), IncHI2, as well as double Inc types IncHI2/IncN and IncHI2/IncQ. mcr-1-carrying plasmids were found in Escherichia coli, Klebsiella pneumoniae, and Kluyvera georgiana, and within the chromosome of an ST147 K. pneumoniae isolate. In depth analysis indicated intrapatient, interpatient, and interspecies transmission events of mcr-1-carrying plasmids. In addition, our results show that the mcr-1 gene resides in a rich environment full of other (mcr-1 negative) plasmids and of many different Inc types, enabling interplasmidal transfer events and facilitating widespread dissemination of the mcr-1 gene. Multiple mcr-1-carrying plasmid transmission events had likely occurred among isolates from hospitalized patients. Recognition and identification of plasmid transmission events within hospitals is necessary in order to design and implement effective infection control measures.

scholarly journals ESβL, AmpC and carbapenemase co-production in multi-drug resistant Gram-negative bacteria from HIV-infected patients in southwestern Nigeria

2021 ◽  
Vol 22 (1) ◽  
pp. 38-51
Author(s):  
F.M. Adeyemi ◽  
S.B. Akinde
Keyword(s):  
Control Measures ◽  
University Teaching ◽  
Teaching Hospitals ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Southwestern Nigeria ◽  
Gram Negative ◽  
Healthcare Facilities ◽  
Infection Control Measures ◽  
Tertiary Healthcare

Background: The rising global emergence of Gram-negative bacteria (GNB) producing β-lactam hydrolysing enzymes in clinical infections constitutes a growing public health threat. This study investigated the occurrence of co-production of extended spectrum β-lactamase (ESβL), AmpC β-lactamases, and carbapenemases among GNB isolated from HIVinfected patients in two tertiary healthcare facilities in southwest Nigeria.Methodology: A total of 115 GNB isolates previously recovered from HIV-infected patients at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, and the State Specialist Hospital, Akure, were investigated. The isolates were characterized to species level with the Microbact 24E kit and screened for ESβL production using the double-disc test (DDT) and combination disc methods, AmpC using modified Hodge test (MHT) and AmpC EDTA disc, and carbapenemase production using the MHT and EDTA disc test. Antibiotic susceptibility testing (AST) was performed by the Kirby-Bauer disc diffusion method.Results: A total of 15 species of GNB were characterized. The AST profile of the isolates revealed high resistance rates to ampicillin (94.5%), tetracycline (74.5%), sulphamethoxazole-trimethoprim (66.3%), and lowest resistance to imipenem (10.9%). Multi-drug resistance (MDR) was observed in 93.6% while 98.8% of ESβL, AmpC, and carbapenemase-producing isolates had multiple antibiotic resistance (MAR) indices ≥ 0.2. ESβL production was detected in 53.9%, AmpC in 20.9% and carbapenemase in 25.2% of the isolates. ESβL, AmpC or carbapenemase or co-production of two or all three enzymes was detected in 80 (69.6%) isolates, while only 10.0% produced all three enzymes.Conclusion: The isolation of MDR bacteria and isolates co-producing β-lactam hydrolysing enzymes in immunocompromised individuals portend grave consequences. Routine screening for these enzymes in MDR bacteria will be highly essential to guide the institution of appropriate antibiotic therapy and infection control measures. Keywords: ESβL, AmpC, carbapenemase, HIV, MDR, clinical isolates, MHT, DDST   French Title: Coproduction d'ESβL, AmpC et carbapénémase dans des bactéries Gram-négatives multirésistantes de patients infectés par le VIH dans le sud-ouest du Nigéria Contexte: L'émergence mondiale croissante de bactéries à Gram négatif (GNB) produisant des enzymes d'hydrolyse de β-lactame dans les infections cliniques constitue une menace croissante pour la santé publique. Cette étude a examiné l'occurrence de la coproduction de β-lactamases à spectre étendu (ESβL), de  β-lactamases AmpC et de carbapénémases parmi les GNB isolés de patients infectés par le VIH dans deux établissements de santé tertiaires du sud-ouest du Nigéria. Méthodologie: Un total de 115 isolats de GNB précédemment récupérés de patients infectés par le VIH au complexe hospitalier universitaire Obafemi Awolowo, Ile-Ife, et au State Specialist Hospital, Akure, ont été  étudiés. Les isolats ont été caractérisés au niveau des espèces avec le kit Microbact 24E et criblés pour la  production d'ESβL en utilisant le test à double disque (DDT) et les méthodes de disques combinés, AmpC en utilisant le test Hodge modifié (MHT) et le disque AmpC EDTA, et la production de carbapénémase en utilisant le MHT et test de disque EDTA. Le test de sensibilité aux antibiotiques (AST) a été effectué par la méthode de diffusion de disque de Kirby-Bauer Résultats: Un total de 15 espèces de GNB ont été caractérisées. Le profil AST des isolats a révélé des taux derésistance élevés à l'ampicilline (94,5%), à la tétracycline (74,5%), au sulfaméthoxazole-triméthoprime (66,3%) età la plus faible résistance à l'imipénème (10,9%). Une résistance à plusieurs médicaments (MDR) a été observéedans 93,6% tandis que 98,8% des isolats producteurs d'ESβL, AmpC et carbapénémase avaient de multiples indices de résistance aux antibiotiques (MAR) ≥ 0,2. La production d'ESβL a été détectée dans 53,9%, AmpC dans 20,9% et carbapénémase dans 25,2% des isolats. ESβL, AmpC ou carbapénémase ou la coproduction de deux ou des trois enzymes a été détectée dans 80 isolats (69,6%), tandis que seulement 10,0% ont produit les trois enzymes. Conclusion: L'isolement des bactéries MDR et des isolats co-producteurs d'enzymes d'hydrolyse des β-lactamines chez les individus immunodéprimés laisse présager de graves conséquences. Le dépistage systématique de ces enzymes dans les bactéries MDR sera très essentiel pour guider la mise en place d'une antibiothérapie appropriée et de mesures de contrôle des infections. Mots-clés: ESβL, AmpC, carbapénémase, VIH, MDR, isolats cliniques, MHT, DDST

scholarly journals Multidrug-resistant organisms detected in refugee patients admitted to a University Hospital, Germany June‒December 2015

2016 ◽  
Vol 21 (2) ◽  
Author(s):  
Claudia Reinheimer ◽  
Volkhard A. J. Kempf ◽  
Stephan Göttig ◽  
Michael Hogardt ◽  
Thomas A. Wichelhaus ◽  
...  
Keyword(s):  
Confidence Interval ◽  
Multidrug Resistant ◽  
Control Measures ◽  
University Hospital ◽  
Healthcare Personnel ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
Infection Control Measures ◽  
Multidrug Resistant Organisms ◽  
The University

Multidrug-resistant Gram-negative bacteria (MDR GNB) were found to colonise 60.8% (95% confidence interval: 52.3–68.9) of 143 refugee patients mainly from Syria (47), Afghanistan (29), and Somalia (14) admitted to the University Hospital Frankfurt, Germany, between June and December 2015. This percentage exceeds the prevalence of MDR GNB in resident patients four–fold. Healthcare personnel should be aware of this and the need to implement or adapt adequate infection control measures.

scholarly journals Comparison of Three Expanded-Spectrum Cephalosporin Hydrolysis Assays and the NG-Test CTX-M Multi Assay That Detects All CTX-M-Like Enzymes

Diagnostics ◽  
2022 ◽  
Vol 12 (1) ◽  
pp. 197
Author(s):  
Camille Gonzalez ◽  
Christian Moguet ◽  
Arnaud Chalin ◽  
Saoussen Oueslati ◽  
Laurent Dortet ◽  
...  
Keyword(s):  
Infection Control ◽  
Rapid Detection ◽  
Resistance Mechanisms ◽  
Control Measures ◽  
Confirmatory Test ◽  
Lateral Flow Immunoassay ◽  
Gram Negative ◽  
Infection Control Measures ◽  
Hands On ◽  
Acinetobacter Spp

Rapid detection of expanded-spectrum cephalosporins (ESC) hydrolysing enzymes is crucial to implement infection control measures and antibiotic stewardship. Here, we have evaluated three biochemical ESC hydrolysis assays (ESBL NDP test, β-LACTA™ test, LFIA-CTX assay) and the NG-Test® CTX-M MULTI that detects CTX-M enzymes, on 93 well-characterized Gram-negative isolates, including 60 Enterobacterales, 21 Pseudomonas spp. and 12 Acinetobacter spp. The performances were good for all three hydrolysis assays, with the LFIA-CTX being slightly more sensitive and specific on the tested panel of isolates especially with Enterobacterales, without ambiguous results. This study showed that LFIA-CTX may be used for the detection of ESC hydrolysis as a competitive alternative to already available assays (β-LACTA™ test and ESBL NDP test) without any specific equipment and reduced hands-on-time. The lateral flow immunoassay NG-Test® CTX-M MULTI has proven to be a useful, easy, rapid, and reliable confirmatory test in Enterobacterales for detection of CTX-M-type ESBLs, which account for most of the resistance mechanisms leading to ESC resistance in Enterobacterales, but it misses rare ESC hydrolysing β-lactamases (AmpC, minor ESBLs, and carbapenemases). Combining it with the LFIA-CTX assay would yield an assay detecting the most frequently-encountered ESBLs (CTX-M-like β-lactamases) together with ESC hydrolysis.

scholarly journals Detection of bacterial samples on the aquatic ecosystems adjacent to Saquarema Lagoon – Rio de Janeiro

2016 ◽  
Vol 14 (2) ◽  
pp. 147
Author(s):  
Barbara Araujo Nogueira ◽  
Julianna Giordano Botelho Olivella ◽  
Adriana Costa Gil ◽  
Frederico Meirelles-Pereira ◽  
Verônica Dias Gonçalves ◽  
...  
Keyword(s):  
Plasmid Dna ◽  
Economic Value ◽  
City Centre ◽  
Gram Negative Bacteria ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Agar Media ◽  
The City ◽  
Constant Growth ◽  
Human Recreation

Introduction: Saquarema Lagoon (RJ) has a high ecological and economic value owing to its multiple uses. The population’s constant growth increases the amount of sewage containing bacteria and antimicrobial drugs that are discharged to the environment. Objectives: to detect Gram negative bacilli able to colonize or infect humans and animals and determine their antimicrobial resistance profiles. Methodology:samples were collected in the city centre in April 2010 and at Jaconé (Lagoon’s most preserved site) in February 2011. The total and thermo tolerant coliforms were determined and the isolation of samples was made using agar media containing  32cg/ mL of cephalotin. All samples were tested for antimicrobial susceptibility (AST) and on 16 samples, plasmid DNA was extracted. Results: different Gram negative bacteria were detected, such as: Enterobacter spp, Citrobacter freundii, Klebsiella pneumoniae and Pseudomonas aeruginosa. The coliform results showed that the water quality is proper for Human recreation. AST results demonstrated the existence of bacteria resistant to antimicrobial drugs frequently used in the community. It was possible to detected high molecular weight plasmids and nine samples (56,25%) showed at least one plasmid DNA electrophoresis band. Conclusions: there were not detected resistant samples to antimicrobial drugs normally used in hospital settings, which may possibly refute the idea of a contamination by nosocomial and/or veterinary sewage discharge.

scholarly journals An Application of Imipenem Discs or P. aeruginosa ATCC 27853 Reference Strain Increases Sensitivity of Carbapenem Inactivation Method for Non-Fermenting Gram-Negative Bacteria

Antibiotics ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 875
Author(s):  
Tomasz Bogiel ◽  
Mateusz Rzepka ◽  
Eugenia Gospodarek-Komkowska
Keyword(s):  
Human Population ◽  
Reference Strain ◽  
Resistance Mechanisms ◽  
Gram Negative Bacteria ◽  
Opportunistic Pathogens ◽  
Beta Lactams ◽  
Gram Negative ◽  
E Coli ◽  
Human Infections ◽  
Reliable Diagnostic Method

Non-fermenting Gram-negative rods are one of the most commonly isolated bacteria from human infections. These microorganisms are typically opportunistic pathogens that pose a serious threat to public health due to possibility of transmission in the human population. Resistance to beta-lactams, due to carbapenemases synthesis, is one of the most important antimicrobial resistance mechanisms amongst them. The aim of this study was to evaluate the usefulness of the Carbapenem Inactivation Method (CIM), and its modifications, for the detection of carbapenemase activity amongst non-fermenting Gram-negative rods. This research involved 81 strains of Gram-negative rods. Of the tested strains, 55 (67.9%) synthesized carbapenemases. For non-fermenting rods, 100% sensitivity and specificity was obtained in the version of the CIM test using imipenem discs and E. coli ATCC 25922 strain. The CIM test allows for differentiation of carbapenems resistance mechanisms resulting from carbapenemase synthesis from other resistance types. It is a reliable diagnostic method for the detection of carbapenemase activity amongst non-fermenting Gram-negative rods. Application of imipenem discs and P. aeruginosa ATCC 27853 reference strain increases CIM results sensitivity, while imipenem discs and E. coli ATCC 25922 strain use maintains full precision of the test for non-fermenting rods.

scholarly journals Antimicrobial Activities of Mefloquine and a Series of Related Compounds

2000 ◽  
Vol 44 (4) ◽  
pp. 848-852 ◽  
Author(s):  
C. M. Kunin ◽  
W. Y. Ellis
Keyword(s):  
Staphylococcus Epidermidis ◽  
Antimicrobial Activities ◽  
Walter Reed Army Institute ◽  
Gram Negative Bacteria ◽  
Antimicrobial Drugs ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Resistant Strains ◽  
Vancomycin Resistant ◽  
Related Compounds

ABSTRACT Mefloquine was found to have bactericidal activity against methicillin- and fluoroquinolone-susceptible and -resistant strains ofStaphylococcus aureus and Staphylococcus epidermidis and gentamicin- and vancomycin-resistant strains ofEnterococcus faecalis and Enterococcus faecium. The MICs were 16 μg/ml, and the minimal bactericidal concentrations (MBCs) were 16 to 32 μg/ml. These concentrations cannot be achieved in serum. Mefloquine was active at a more achievable concentration against penicillin-susceptible and -resistant Streptococcus pneumoniae, with MICs of 0.2 to 1.5 μg/ml. Mefloquine was not active against gram-negative bacteria and yeasts. In an attempt to find more active derivatives, 400 mefloquine-related compounds were selected from the chemical inventory of The Walter Reed Army Institute of Research. We identified a series of compounds containing a piperidine methanol group attached to pyridine, quinoline, and benzylquinoline ring systems. These had activities similar to that of mefloquine against S. pneumoniae but were far more active against other gram-positive bacteria (MICs for staphylococci, 0.8 to 6.3 μg/ml). They had activities similar to that of amphotericin B againstCandida spp. and Cryptococcus neoformans. Combinations of the compounds with gentamicin and vancomycin were additive against staphylococci and pneumococci. The MIC and MBC of gentamicin were decreased by four- to eightfold when this drug was combined with limiting dilutions of the compounds. There was no antagonism with other antimicrobial drugs. The compounds were rapidly bactericidal. They appear to act by disrupting cell membranes. Combinations of the compounds with aminoglycoside antibiotics may have potential for therapeutic use.

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