scholarly journals Comparison of clinical characteristics and outcomes of bloodstream infections due to multidrug-resistant Acinetobacter baumannii and other Gram-negative bacteria in ICU patients

2020 ◽  
Author(s):  
Ying Qian ◽  
Yongpeng Xie ◽  
Haifeng Mao ◽  
Jiguang Li ◽  
Caihong Gu ◽  
...  
Keyword(s):  
Septic Shock ◽  
Drug Resistance ◽  
Acinetobacter Baumannii ◽  
Clinical Characteristics ◽  
Multidrug Resistant ◽  
Resistance Rate ◽  
Apache Ii Score ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli

Abstract Background: Multidrug-resistant (MDR) bloodstream infection (BSI) by Gram-negative bacteria (GNB) is an important cause of mortality in the intensive care unit (ICU). The purpose of this study was to compare the clinical characteristics of some GNB BSIs and to analyze their drug resistance, with an emphasis on the analysis of prognostic risk factors related to MDR-Acinetobacter baumannii (A. baumannii) BSI.Methods: A retrospective study was conducted in the ICU of lianyungang hospital in China. Patients with BSIs due to MDR-A. baumannii, MDR-Klebsiella pneumoniae (K. pneumoniae), MDR-Pseudomonas aeruginosa (P. aeruginosa) and MDR-Escherichia coli (E. coli) were included.Results: The overall drug resistance rate to imipenem of A. baumannii and K. pneumoniae was significantly higher than that of P. aeruginosa and E. coli (95.8% and 75.5% vs 44.6% and 9.2% respectively). The mortality rates were 71.9%, 63.3%, 41.5% and 38.1%, respectively. The multivariate analysis of MDR-A. baumannii BSI, APACHE II score, hormone use, development of septic shock were associated with the 30-day mortality, while high albumin level with survival.Conclusion: The treatment of MDR-A. baumannii and MDR-K. pneumoniae infection resulted difficult due to their high drug resistance rate. However, the understanding of the clinical characteristics of different BSIs might be helpful to predict, to some extent, the pathogenic bacteria involved so as to proceed with an early sensitive antibiotic treatment. The high mortality rate due to BSI MDR-A. baumannii might be correlated with APACHE II score, nutritional status, and hormone therapy, while septic shock was a warning sign of poor prognosis.

scholarly journals Interaction of Antimicrobial Peptide Temporin L with Lipopolysaccharide In Vitro and in Experimental Rat Models of Septic Shock Caused by Gram-Negative Bacteria

2006 ◽  
Vol 50 (7) ◽  
pp. 2478-2486 ◽  
Author(s):  
Andrea Giacometti ◽  
Oscar Cirioni ◽  
Roberto Ghiselli ◽  
Federico Mocchegiani ◽  
Fiorenza Orlando ◽  
...  
Keyword(s):  
Septic Shock ◽  
Antimicrobial Peptide ◽  
Gram Negative Bacteria ◽  
Amphibian Skin ◽  
Necrosis Factor Alpha ◽  
Gram Negative ◽  
Rat Models ◽  
E Coli ◽  
Tnf Α

ABSTRACT Sepsis remains a major cause of morbidity and mortality in hospitalized patients, despite intense efforts to improve survival. The primary lead for septic shock results from activation of host effector cells by endotoxin, the lipopolysaccharide (LPS) associated with cell membranes of gram-negative bacteria. For these reasons, the quest for compounds with antiendotoxin properties is actively pursued. We investigated the efficacy of the amphibian skin antimicrobial peptide temporin L in binding Escherichia coli LPS in vitro and counteracting its effects in vivo. Temporin L strongly bound to purified E. coli LPS and lipid A in vitro, as proven by fluorescent displacement assay, and readily penetrated into E. coli LPS monolayers. Furthermore, the killing activity of temporin L against E. coli was progressively inhibited by increasing concentrations of LPS added to the medium, further confirming the peptide's affinity for endotoxin. Antimicrobial assays showed that temporin L interacted synergistically with the clinically used β-lactam antibiotics piperacillin and imipenem. Therefore, we characterized the activity of temporin L when combined with imipenem and piperacillin in the prevention of lethality in two rat models of septic shock, measuring bacterial growth in blood and intra-abdominal fluid, endotoxin and tumor necrosis factor alpha (TNF-α) concentrations in plasma, and lethality. With respect to controls and single-drug treatments, the simultaneous administration of temporin L and β-lactams produced the highest antimicrobial activities and the strongest reduction in plasma endotoxin and TNF-α levels, resulting in the highest survival rates.

scholarly journals A high prevalence of multi-drug resistant Gram-negative bacilli in a Nepali tertiary care hospital and associated widespread distribution of Extended-Spectrum Beta-Lactamase (ESBL) and carbapenemase-encoding genes

2020 ◽  
Vol 19 (1) ◽  
Author(s):  
Sulochana Manandhar ◽  
Raphael M. Zellweger ◽  
Nhukesh Maharjan ◽  
Sabina Dongol ◽  
Krishna G. Prajapati ◽  
...  
Keyword(s):  
Drug Resistance ◽  
Tertiary Care ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Care Hospital ◽  
Global Public Health ◽  
Gram Negative ◽  
E Coli ◽  
Extended Spectrum ◽  
High Prevalence

Abstract Background Multi-drug resistance (MDR) and extensive-drug resistance (XDR) associated with extended-spectrum beta-lactamases (ESBLs) and carbapenemases in Gram-negative bacteria are global public health concerns. Data on circulating antimicrobial resistance (AMR) genes in Gram-negative bacteria and their correlation with MDR and ESBL phenotypes from Nepal is scarce. Methods A retrospective study was performed investigating the distribution of ESBL and carbapenemase genes and their potential association with ESBL and MDR phenotypes in E. coli, Klebsiella spp., Enterobacter spp. and Acinetobacter spp. isolated in a major tertiary hospital in Kathmandu, Nepal, between 2012 and 2018. Results During this period, the hospital isolated 719 E. coli, 532 Klebsiella spp., 520 Enterobacter spp. and 382 Acinetobacter spp.; 1955/2153 (90.1%) of isolates were MDR and half (1080/2153) were ESBL producers. Upon PCR amplification, blaTEM (1281/1771; 72%), blaCTXM-1 (930/1771; 53%) and blaCTXM-8 (419/1771; 24%) were the most prevalent ESBL genes in the enteric bacilli. BlaOXA and blaOXA-51 were the most common blaOXA family genes in the enteric bacilli (918/1771; 25%) and Acinetobacter spp. (218/382; 57%) respectively. Sixteen percent (342/2153) of all isolates and 20% (357/1771) of enteric bacilli harboured blaNDM-1 and blaKPC carbapenemase genes respectively. Of enteric bacilli, Enterobacter spp. was the most frequently positive for blaKPC gene (201/337; 60%). The presence of each blaCTX-M and blaOXA were significantly associated with non-susceptibility to third generation cephalosporins (OR 14.7, p < 0.001 and OR 2.3, p < 0.05, respectively).The presence of each blaTEM, blaCTXM and blaOXA family genes were significantly associated with ESBL positivity (OR 2.96, p < 0.001; OR 14.2, p < 0.001 and OR 1.3, p < 0.05 respectively) and being MDR (OR 1.96, p < 0.001; OR 5.9, p < 0.001 and OR 2.3, p < 0.001 respectively). Conclusions This study documents an alarming level of AMR with high prevalence of MDR ESBL- and carbapenemase-positive ESKAPE microorganisms in our clinical setting. These data suggest a scenario where the clinical management of infected patients is increasingly difficult and requires the use of last-resort antimicrobials, which in turn is likely to intensify the magnitude of global AMR crisis.

scholarly journals Heterogeneous and Flexible Transmission ofmcr-1in Hospital-AssociatedEscherichia coli

mBio ◽  
2018 ◽  
Vol 9 (4) ◽  
Author(s):  
Yingbo Shen ◽  
Zuowei Wu ◽  
Yang Wang ◽  
Rong Zhang ◽  
Hong-Wei Zhou ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Genomic Analysis ◽  
Multidrug Resistant ◽  
Fluoroquinolone Resistance ◽  
Gram Negative Bacteria ◽  
Colistin Resistance ◽  
Gram Negative ◽  
Content Type ◽  
E Coli ◽  
Genes Encoding

ABSTRACTThe recent emergence of a transferable colistin resistance mechanism, MCR-1, has gained global attention because of its threat to clinical treatment of infections caused by multidrug-resistant Gram-negative bacteria. However, the possible transmission route ofmcr-1amongEnterobacteriaceaespecies in clinical settings is largely unknown. Here, we present a comprehensive genomic analysis ofEscherichia coliisolates collected in a hospital in Hangzhou, China. We found thatmcr-1-carrying isolates from clinical infections and feces of inpatients and healthy volunteers were genetically diverse and were not closely related phylogenetically, suggesting that clonal expansion is not involved in the spread ofmcr-1. Themcr-1gene was found on either chromosomes or plasmids, but in most of theE. coliisolates,mcr-1was carried on plasmids. The genetic context of the plasmids showed considerable diversity as evidenced by the different functional insertion sequence (IS) elements, toxin-antitoxin (TA) systems, heavy metal resistance determinants, and Rep proteins of broad-host-range plasmids. Additionally, the genomic analysis revealed nosocomial transmission ofmcr-1and the coexistence ofmcr-1with other genes encoding β-lactamases and fluoroquinolone resistance in theE. coliisolates. These findings indicate thatmcr-1is heterogeneously disseminated in both commensal and pathogenic strains ofE. coli, suggest the high flexibility of this gene in its association with diverse genetic backgrounds of the hosts, and provide new insights into the genome epidemiology ofmcr-1among hospital-associatedE. colistrains.IMPORTANCEColistin represents one of the very few available drugs for treating infections caused by extensively multidrug-resistant Gram-negative bacteria. The recently emergentmcr-1colistin resistance gene threatens the clinical utility of colistin and has gained global attention. Howmcr-1spreads in hospital settings remains unknown and was investigated by whole-genome sequencing ofmcr-1-carryingEscherichia coliin this study. The findings revealed extraordinary flexibility ofmcr-1in its spread among genetically diverseE. colihosts and plasmids, nosocomial transmission ofmcr-1-carryingE. coli, and the continuous emergence of novel Inc types of plasmids carryingmcr-1and newmcr-1variants. Additionally,mcr-1was found to be frequently associated with other genes encoding β-lactams and fluoroquinolone resistance. These findings provide important information on the transmission and epidemiology ofmcr-1and are of significant public health importance as the information is expected to facilitate the control of this significant antibiotic resistance threat.

scholarly journals 2217. Frequency and Antimicrobial Susceptibility of Bacteria Isolated from Patients Hospitalized with Pneumonia in US Medical Centers During 2018

2019 ◽  
Vol 6 (Supplement_2) ◽  
pp. S756-S756
Author(s):  
Helio S Sader ◽  
Michael D Huband ◽  
Cecilia G Carvalhaes ◽  
Mariana Castanheira
Keyword(s):  
Multidrug Resistant ◽  
Gram Negative Bacteria ◽  
Bacterial Isolates ◽  
Central Laboratory ◽  
Active Compounds ◽  
Gram Negative ◽  
E Coli ◽  
Medical Centers ◽  
Carbapenem Resistant ◽  
Esbl Producers

Abstract Background Rapidly introducing appropriate antimicrobial therapy is crucial to reduce morbidity and mortality of patients hospitalized with pneumonia (PHP), and therapy is determined mostly by understanding causative pathogens. Ceftazidime–avibactam (CAZ-AVI) was recently approved and ceftolozane–tazobactam (C-T) is in late-stage clinical development for treating nosocomial pneumonia, including ventilator-associated. Methods Bacterial isolates were consecutively collected from PHP (1/patient) in 67 US medical centers in 2018 and the Gram-negative bacilli (GNB) were tested by reference broth microdilution methods for susceptibility (S) to CAZ-AVI, C-T, and many comparators at a central laboratory. Results The most common organisms isolated from PHP were S. aureus (27.0%), P. aeruginosa (PSA) (24.6%), K. pneumoniae (KPN; 7.6%), E. coli (6.8%), S. marcescens (5.4%), and S. maltophilia (XM; 4.5%). Colistin (99.7%S), CAZ-AVI (95.7%S), and C-T (94.9%S) were the most active compounds against PSA; CAZ-AVI (99.9%S), amikacin (AMK; 98.8%S), and meropenem (MEM; 97.6%S) were the most active compounds against Enterobacterales (ENT). CAZ-AVI and C-T retained activity against PSA isolates non-S (NS) to piperacillin–tazobactam (PIP-TAZ), MEM, and cefepime (FEP), whereas PSA isolates NS to PIP-TAZ, MEM, or FEP exhibited low S rates to PIP-TAZ (≤ 39.2%), MEM (≤ 37.8%), and FEP (≤ 38.0%; Table). CAZ-AVI and tigecycline were the only compounds with good activity against carbapenem-resistant ENT (CRE), both with 96.6%S. Among ENT, the most common ESBL and carbapenemase were CTX-M-15 (73%) and KPC-2/3 (76%), respectively. CAZ-AVI was active against all ESBL producers (100.0%S), whereas the S rate to C-T was 82.4%. The most active compounds against multidrug-resistant (MDR) ENT were CAZ-AVI (98.9%S), AMK (91.5%S), and MEM (80.8%S). XM and A. baumannii exhibited low S rates to most antimicrobials tested. Conclusion Gram-negative bacteria were isolated from 70% of PHP, and PSA and ENT represented >80% of these organisms. CAZ-AVI and C-T showed similar coverage (%S) against PSA (95.7–94.9%S). In contrast, C-T was less active than CAZ-AVI against ENT in general and exhibited limited activity against ENT-resistant subsets. Disclosures All authors: No reported disclosures.

scholarly journals Investigation of urban birds as source of β-lactamase-producing Gram-negative bacteria in Marseille city, France

2019 ◽  
Vol 61 (1) ◽  
Author(s):  
Edgarthe Priscilla Ngaiganam ◽  
Isabelle Pagnier ◽  
Wafaa Chaalal ◽  
Thongpan Leangapichart ◽  
Selma Chabou ◽  
...  
Keyword(s):  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Gram Negative Bacteria ◽  
Urban Birds ◽  
Multidrug Resistant Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Stool Samples

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.

scholarly journals A Study the Effect of TiO2 Nanoparticles Combination with Antibiotics and Plant extracts Against Some Gram Negative Bacteria

2016 ◽  
Vol 13 (3) ◽  
pp. 425-434
Author(s):  
Baghdad Science Journal
Keyword(s):  
Titanium Dioxide ◽  
Acinetobacter Baumannii ◽  
Tio2 Nanoparticles ◽  
Plant Extracts ◽  
Salvia Officinalis ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
E Coli ◽  
Origanum Majorana ◽  
Arctium Minus

Titanium dioxide TiO2 has been widely utilized in cleaning and sterilizing material for many clinical tools sanitary ware, food tableware and cooking and items for use in hospitals. Titanium dioxide TiO2 non toxicity and long term physical and chemical stability. It has been widely used decomposition of organic compounds and microbial organisms such as cancer cell, viruses and bacteria as well as its potential application in sterilization of medical devices. The aim of the study the effect of titanium dioxide TiO2 on some Gram negative bacteria and study their effects on some virulence factors and chromosomal DNA.In this study, we obtained (E. coli ? Proteus mirabilis, Proteus vulgaris ? Pseudomonas aeruginosa ? Klebsiella pneumonia and Acinetobacter baumannii) from Al-Emamain Al-Kadhemain Medical City Hospital in Baghdad. Samples collection were carried out from 1 April to 30 June 2014. Study the effect of (plant extraction and Antibiotic) alone and combination with Titanium dioxide TiO2 on bacteria growth. And study the effect of Titanium dioxide TiO2 on biofilm layer and chromosomal DNA.Combinations of TiO2 nanoparticle with water and alcohol extracts of plant (Salvia officinalis ?Arctium minus, Origanum majorana and Anabasis syriaca) gave synergistic results against the gram negative bacterial isolates.A Synergism effect was observed in combination of Ciprofloxacin with Titanium TiO2 nanoparticles toward all Gram negative bacteria. Also a high efficiency was observed when TiO2 nanoparticles mixed with Amikacin toward all isolates except Acinetobacter baumannii and E. coli3. While the results of mixing TiO2 nanoparticles with Cephalothin indicate highly efficiency toward all isolates except Pseudomonas aeruginosa.The combination of plant extracts (Salvia officinalis ? Arctium minus ? Origanum majorana and Anabasis syriaca) with TiO2 nanoparticles was appear to be damaged to E. coli chromosomal DNA.The study showed the ability of nanoparticles TiO2 to inhibition of the layer Biofilm to all isolates of bacteria at concentrations (1, 1.5) µg/ ml.Conclude from this study we can be used TiO2 nanoparticles to kill some types of bacteria

scholarly journals Epidemiology of Multidrug-resistant Bacteria Isolated from Hospitalized Patients in a Regional Central Hospital in China

2020 ◽  
Author(s):  
Jixun Zhang ◽  
Rui Li ◽  
Zhenzhong Liu ◽  
Chao Wang
Keyword(s):  
Pseudomonas Aeruginosa ◽  
Acinetobacter Baumannii ◽  
Multidrug Resistant ◽  
Hospitalized Patients ◽  
Resistant Bacteria ◽  
Central Hospital ◽  
Gram Negative ◽  
E Coli ◽  
Significant Difference ◽  
The Impact

Abstract Objectives: Considering the dynamic changes of MDR, we did an up-to-date study and analyzed the impact of MDR on the outcome of patients. Design: Collected MDR isolated from hospitalized patients between June 2018 and May 2020 and performed retrospective analysis. Setting: This study was conducted in a public regional central hospital in China.Patients: 1156 patients with MDR infections.Results: Total 1291 MDRS were isolated, intensive care unit (ICU) accounted for 32.3% as the most. The main samples were sputum (75.1%) and 89.6% MDR were Gram-negative. The most common MDR were Acinetobacter baumannii, carbapenemase-producing K. pneumoniae, Pseudomonas aeruginosa, ESBL-producing E. coli. Methicillin-resistant Staphylococcus aureus (MRSA) and ESBL-producing K.pneumoniae. 35.6% were nosocomial infections and 64.4% were community-acquired infections. There was a statistically significant difference in mortality between patients infected with MDR and those with non-MDR (7.4% [32/432] vs 2.6% [17/655]; P = 0.001). The Acinetobacter baumannii and Klebsiella pneumoniae were mainly sensitive to tigecycline. The Pseudomonas aeruginosa was mainly sensitive to amikacin and levofloxacin. More than 80% of the Escherichia coli were sensitive to tigecycline and carbapenems. More than 90% of MRSA were sensitive to vancomycin, linezolid, and quinoprptin / daptoptin.Conclusions: The MDRS are mainly gram-negative bacteria. ICU contributes most MDR and pulmonary infection is the main origin of MDR. MDR infection is an independent risk factor for death. ESBL-producing Enterobacteriaceae, especially carbapenemase producing Enterobacteriaceae, should be paid more attention. This study is helpful to understand the distribution of MDR in hospital and the extent of antibiotic resistance.

scholarly journals Neonate Bloodstream Infections (BSI) in China: Emerging Threat of Multidrug-resistant (MDR) pathogens

2020 ◽  
Author(s):  
hua zou ◽  
Ligang Zhou ◽  
Yan Shen ◽  
Chunli Li ◽  
Qiuhong Li
Keyword(s):  
Early Onset ◽  
Pathogenic Bacteria ◽  
Late Onset ◽  
Bloodstream Infections ◽  
Multidrug Resistant ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Antibiotic Exposure ◽  
Gram Negative ◽  
E Coli

Abstract Background: Bloodstream Infections (BSIs) continue to be associated with significant morbidity and mortality worldwide, which multidrug-resistant (MDR) pathogens present an ever-growing burden in the hospital and community settings. Data on antimicrobial resistance and prevalence of BSIs pathogens among hospitalized neonates in China are few and not clearly defined. Methods: we retrospectively collected clinical and bacteria data about patients with BSI from 2013 to 2017 in Chongqing Health Center for Women and Children. The patients were divided into the early- and late-onset BSI groups according to if BSI occurred within or beyond 72 hours after admission.Results: 210 BSIs occurred from January 1st, 2014 to December 31th, 2019. Of all included 210 patients, there were 99(47.14%), 105 (50.00%), and 6 (2.86%) infected with gram-positive bacteria, gram-negative bacteria, and fungi, respectively. For early-onset BSI, the predominated pathogen was E. coli, accounting for 59.6% with 29.72% producing of extended-spectrum beta-lactamases (ESBLs). CNS (40.3%), K. pneumoniae (23.8%), and E. coli (20.9%) constitute the main causes of late-onset BSIs. Notably, 75.0% of K. pneumoniae produced ESBLs and 81.3% were MDR, which were higher than early-onset BSIs. Late onset BSIs and antibiotic exposure were significantly associated with MDR infection. Conclusion: Gram-negative bacteria gradually became the main pathogenic bacteria, among which E. coli and K. pneumoniae accounted for the largest proportion. The phenomenon of multi-drug resistance of bacteria is serious, and the first-line drug can't meet the practical needs. Late onset sepsis and antibiotic exposure were significantly associated with MDR infection.

scholarly journals Identification of Ly2 members as antimicrobial peptides from zebrafish Danio rerio

2017 ◽  
Vol 37 (1) ◽  
Author(s):  
Xuemin Liu ◽  
Xuwen Cao ◽  
Su Wang ◽  
Guangdong Ji ◽  
Shicui Zhang ◽  
...  
Keyword(s):  
Antimicrobial Peptides ◽  
Recombinant Proteins ◽  
Mammalian Cells ◽  
Multidrug Resistant ◽  
Scatchard Analysis ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
E Coli ◽  
Gram Positive Bacteria

The emergence of multidrug-resistant (MDR) microbes caused by overuse of antibiotics leads to urgent demands for novel antibiotics exploration. Our recent data showed that Ly2.1–3 (a novel lymphocyte antigen 6 (Ly6) gene cluster) were proteins with cationic nature and rich in cysteine content, that are characteristic of antimicrobial peptides (AMPs) and their expression were all significantly up-regulated after challenge with lipopolysaccharide (LPS). These strongly suggested that Ly2.1–3 are potential AMPs, but firm evidence are lacking. Here, we clearly showed that the recombinant proteins of Ly2.1–3 were capable of killing Gram-negative bacteria Aeromonas hydrophila and Escherichia coli, while they had little bactericidal activity against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis. We also showed that recombinant proteins Ly2.1–3 (rLy2.1–3) were able to bind to the Gram-negative bacteria A. hydrophila, E. coli and the microbial signature molecule LPS, but not to the Gram-positive bacteria S. aureus and B. subtilis as well as the microbial signature molecule LTA. Moreover, the Scatchard analysis revealed that rLy2.1–3 could specifically bind to LPS. Finally, we found that Ly2.1–3 were not cytotoxic to mammalian cells. All these together indicate that Ly2.1–3 can function as AMPs.

scholarly journals Antibiotic resistance and detection of plasmid mediated colistin resistance mcr-1 gene among Escherichia coli and Klebsiella pneumoniae isolated from clinical samples

Gut Pathogens ◽  
2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Deepa Karki ◽  
Binod Dhungel ◽  
Srijana Bhandari ◽  
Anil Kunwar ◽  
Prabhu Raj Joshi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Drug Resistance ◽  
Klebsiella Pneumoniae ◽  
Clinical Samples ◽  
Gram Negative Bacteria ◽  
Beta Lactamase ◽  
Drug Resistant ◽  
Colistin Resistance ◽  
Gram Negative ◽  
E Coli

Abstract Background The prevalence of antimicrobial resistance (AMR) among Gram-negative bacteria is alarmingly high. Reintroduction of colistin as last resort treatment in the infections caused by drug-resistant Gram-negative bacteria has led to the emergence and spread of colistin resistance. This study was designed to determine the prevalence of drug-resistance among beta-lactamase-producing strains of Escherichia coli and Klebsiella pneumoniae, isolated from the clinical specimens received at a tertiary care centre of Kathmandu, Nepal during the period of March to August, 2019. Methods A total of 3216 different clinical samples were processed in the Microbiology laboratory of Kathmandu Model Hospital. Gram-negative isolates (E. coli and K. pneumoniae) were processed for antimicrobial susceptibility test (AST) by using modified Kirby-Bauer disc diffusion method. Drug-resistant isolates were further screened for extended-spectrum beta-lactamase (ESBL), metallo-beta-lactamase (MBL), carbapenemase and K. pneumoniae carbapenemase (KPC) production tests. All the suspected enzyme producers were processed for phenotypic confirmatory tests. Colistin resistance was determined by minimum inhibitory concentration (MIC) using agar dilution method. Colistin resistant strains were further screened for plasmid-mediated mcr-1 gene using conventional polymerase chain reaction (PCR). Results Among the total samples processed, 16.4% (529/3216) samples had bacterial growth. A total of 583 bacterial isolates were recovered from 529 clinical samples. Among the total isolates, 78.0% (455/583) isolates were Gram-negative bacteria. The most predominant isolate among Gram-negatives was E. coli (66.4%; 302/455) and K. pneumoniae isolates were 9% (41/455). In AST, colistin, polymyxin B and tigecycline were the most effective antibiotics. The overall prevalence of multidrug-resistance (MDR) among both of the isolates was 58.0% (199/343). In the ESBL testing, 41.1% (n = 141) isolates were confirmed as ESBL-producers. The prevalence of ESBL-producing E. coli was 43% (130/302) whereas that of K. pneumoniae was 26.8% (11/41). Similarly, 12.5% (43/343) of the total isolates, 10.9% (33/302) of E. coli and 24.3% of (10/41) K. pneumoniae were resistant to carbapenem. Among 43 carbapenem resistant isolates, 30.2% (13/43) and 60.5% (26/43) were KPC and MBL-producers respectively. KPC-producers isolates of E. coli and K. pneumoniae were 33.3% (11/33) and 20% (2/10) respectively. Similarly, 63.6% (21/33) of the E. coli and 50% (5/10) of the K. pneumoniae were MBL-producers. In MIC assay, 2.2% (4/179) of E. coli and 10% (2/20) of K. pneumoniae isolates were confirmed as colistin resistant (MIC ≥ 4 µg/ml). Overall, the prevalence of colistin resistance was 3.1% (6/199) and acquisition of mcr-1 was 16.6% (3/18) among the E. coli isolates. Conclusion High prevalence of drug-resistance in our study is indicative of a deteriorating situation of AMR. Moreover, significant prevalence of resistant enzymes in our study reinforces their roles in the emergence of drug resistance. Resistance to last resort drug (colistin) and the isolation of mcr-1 indicate further urgency in infection management. Therefore, extensive surveillance, formulation and implementation of effective policies, augmentation of diagnostic facilities and incorporation of antibiotic stewardship programs can be some remedies to cope with this global crisis.

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