scholarly journals Challenges in identification of enteroinvasive Escherichia coli and Shigella spp. in Lebanon

Author(s):  
Fatima Bachir Halimeh ◽  
Rayane Rafei ◽  
Seydina Diene ◽  
Mary Mikhael ◽  
Hassan Mallat ◽  
...  

Abstract This study aimed to evaluate the routine identification tools available in Lebanon for differentiation of Escherichia coli and Shigella spp. The identification of 43 isolates defined as Shigella spp. by Api 20E was accessed using MALDI-TOF, serological testing, duplex PCR targeting ipaH (present in Shigella spp. and enteroinvasive E. coli “EIEC”) and lacY (found in E. coli including EIEC but not Shigella spp.) as well as gyrB gene sequencing. Antibiotic susceptibility was investigated as well as Shiga-toxin production. All isolates were identified as E. coli by MALDI-TOF while the PCR showed a disparate group of 26 EIEC, 11 Shigella spp., 5 E. coli and 1 inactive E. coli. However, the sequencing of gyrB gene, which was recently described as a suitable marker for distinguishing E. coli and Shigella spp., identified all isolates as E. coli. Antibiotic resistance was noticeable against ß-lactams, rifampicin, trimethoprim-sulfamethoxazole, gentamicin, and ciprofloxacin. The most common variants of beta-lactamase genes were blaTEM-1, blaCTX-M-15, and blaCTX-M-3. A great discordance between the used methods in identification was revealed herein. An accurate identification technique able to distinguish E. coli from Shigella spp. in routine laboratories is a pressing need in order to select the appropriate treatment and assess the epidemiology of these bacteria.

Author(s):  
Mehmet E. Bulut ◽  
Gülen Hürkal ◽  
Nazan Dalgıç

Abstract Objective Antimicrobial resistance poses a serious threat to children's health. In recent years, high-risk Escherichia coli ST131 has become an important target for global surveillance studies. The E.coli ST131 clone is associated with extended spectrum β-lactamase (ESBL) production, as well as multidrug resistance and treatment failure. Studies on this clone in the pediatric age group are limited. We aim to investigate the rate of high-risk E. coli ST131 clone in ESBL-positive E. coli isolates obtained from pediatric patients. Methods A total of 292 ESBL-positive E. coli isolates from clinical samples of pediatric patients was included in the study. MALDI-TOF MS system was used for bacterial identification. Susceptibility tests were performed using BD Phoenix automated system. ST131 detection was done by MALDI-TOF-MS. Fisher's exact test was used to compare the groups (significance <0.05). Results A total of 292 isolates was analyzed. The high-risk ST131 clone was detected in 117 (40%) of the 292 ESBL-positive isolates. ST131 rates were found to be significantly higher in children under the age of 5 years compared with children over the age of 5 years (49.3 vs. 31.1%, p = 0.0019). Ciprofloxacin resistance was higher in ST131 isolates (45.6 vs. 31.7%; p < 0.05). Conclusion The rate of the ST131 clone was found to be high in the pediatric population. The significantly high rate of resistance to ciprofloxacin, which is not commonly used in the pediatric population, in ST131 isolates reveals the importance of the spread of high-risk clones for the development of resistance.


2020 ◽  
Author(s):  
Mohammad Hasan Namaei ◽  
Hengameh Hamzei ◽  
Marzie Moghanni ◽  
Azadeh Ebrahimzadeh

Abstract Background: Urinary Tract Infection (UTI) is the most common bacterial infection in the world. E. coli is the predominant Pathogen. This study evaluates the prevalence of ESBL in E. colis isolated from patients with urinary tract infections with phenotypic and genotypic methods.Methods: This descriptive-analytical study was done on 155 isolates of E. coli isolated from patients with urinary tract infection who had received the study consent. After accurate identification of E. coli strains. ESBL production for Escherichia coli isolates which are resistant to ceftriaxone or ceftazidime was evaluated by CDT method. TEM, SHV and CTX-M genes were identified by PCR.Results: The results showed that 30 strains from 155 strains of E. coli had ESBL. Strains of ESBL producer were more in males was lower in educated persons. 38.9% of ESBL producer had antibiotic use, 29.9% -producing Escherichia hospitalization and 31.6% uti history. The highest level of drug allergy in the ESBL was related to nitrofurantoin, and the highest resistance was related to cefazolin, co-trimoxazole. The CTX-M and the CTX-M15 gene were found in 92.7% and 57.1% of cases, respectively; also the SHV and TEM genes were not found in any of ESBL-producing Escherichia coli strains. Most therapeutic response in patients was related to cefexime, ciprofloxacin and nitrofurantoin 27.4%, 26% 21.9%, respectively.Conclusion: This study showed that the history of antibiotic use, hospitalization, uti related to increase of ESBL-producing in E. coli isolates., the CTMX-M gene is the most common gene in ESBL-producing E. coli strains.


2018 ◽  
pp. 1720-1724 ◽  
Author(s):  
Shahin Mahmud ◽  
K. H. M. Nazmul Hussain Nazir ◽  
Md. Tanvir Rahman

Aim: The present study was carried out to determine the prevalence and molecular detection of fluoroquinolone-resistant Escherichia coli carrying qnrA and qnrS genes in healthy broiler chickens in Mymensingh, Bangladesh, and also to identify the genes responsible for such resistance. Materials and Methods: A total of 65 cloacal swabs were collected from apparently healthy chickens of 0-14 days (n=23) and 15-35 days (n=42) old. The samples were cultured onto Eosin Methylene Blue Agar, and the isolation and identification of the E. coli were performed based on morphology, cultural, staining, and biochemical properties followed by polymerase chain reaction (PCR) targeting E. coli 16S rRNA genes. The isolates were subjected to antimicrobial susceptibility test against five commonly used antibiotics under fluoroquinolone (quinolone) group, namely gatifloxacin, levofloxacin, moxifloxacin, ofloxacin, and pefloxacin by disk diffusion method. Detection of qnrA and qnrS genes was performed by PCR. Results: Among the 65 cloacal samples, 54 (83.08%) were found to be positive for E. coli. Antibiotic sensitivity test revealed that, of these 54 isolates, 18 (33.33%) were found to be resistant to at least one fluoroquinolone antibiotic. The highest resistance was observed against pefloxacin (61.11%). By PCR, of 18 E. coli resistant to fluoroquinolone, 13 (72.22%) were found to be positive for the presence of qnrS. None of the isolates were found positive for qnrA. Conclusion: Fluoroquinolone-resistant E. coli harboring qnrS genes is highly prevalent in apparently healthy broiler chickens and possesses a potential threat to human health.


2019 ◽  
Vol 11 (04) ◽  
pp. 346-351
Author(s):  
Pankaj Singh ◽  
Sharda C. Metgud ◽  
Subarna Roy ◽  
Shashank Purwar

Abstract CONTEXT: Diarrheagenic Escherichia coli (DEC) is the leading cause of infectious diarrhea in developing countries. On the basis of virulence and phenotypic characteristics, the DEC is categorized into multiple pathotypes. Each pathotype has different pathogenesis and geographical distribution. Thus, the proper management of disease relies on rapid and accurate identification of DEC pathotypes. AIMS: The aim of the study was to determine the prevalence of DEC pathotypes in India. MATERIALS AND METHODS: A cross-sectional study was carried out between January 2008 and December 2012 at Jawaharlal Nehru Medical College and KLES Dr. Prabhakar Kore Hospital and Medical Research Center, Belgaum (Karnataka), India. A total of 300 stool samples were collected from diarrhea patients with age >3 months. The DEC was identified by both conventional and molecular methods. RESULTS: Of 300 samples, E. coli were detected in 198 (66%) and 170 (56.6%) samples by culture and polymerase chain reaction, respectively. Among DEC (n = 198) isolates, eae gene (59.5%) was the most prevalent followed by stx (27.7%), east (27.2%), elt (12.6%), est (10.6%), ipaH (5.5%), and eagg (1.5%) genes. On the basis of virulence genes, enteropathogenic E. coli (33.8%) was the most common pathotype followed by Shiga toxin-producing E. coli (STEC, 23.2%), enterotoxigenic E. coli (ETEC, 13.6%), enteroinvasive E. coli (5.5%), enteroaggregative heat-stable enterotoxin 1-harboring E. coli (EAST1EC, 4.5%), STEC/ETEC (3.5%), STEC/enteroaggregative E. coli (STEC/EAEC, 1.0%), and EAEC (0.05%). CONCLUSIONS: The hybrid DEC is potentially more virulent than basic pathotypes. The pathotyping should be included in clinical settings for the proper management of DEC-associated diarrhea.


2017 ◽  
Vol 37 (12) ◽  
pp. 1373-1379
Author(s):  
Daniele Bier ◽  
Juliane F. Tutija ◽  
Taynara N. Pasquatti ◽  
Tayná L. Oliveira ◽  
Flábio R. Araújo ◽  
...  

RESUMO: O objetivo deste trabalho foi introduzir a técnica de espectrometria de massa com fonte de ionização e dessorção a laser assistida por matriz e analisador de tempo-de-voo (MALDI-TOF) para incrementar o método tradicional microbiológico na detecção de Salmonella spp. e Escherichia coli em carcaças bovinas. Foram avaliadas 270 amostras de 90 carcaças de bovinos. Para isolamento de Salmonella spp. e E. coli, foram utilizadas, respectivamente, as metodologias descritas na ISO 6579:2002 e no Compendium of Methods for the Microbiological Examination of Foods. As análises por MALDI-TOF foram realizadas a partir de isolados cultivados em ágar nutriente ou em caldo triptona de soja, provenientes das amostras com características bioquímicas positivas (n=7), inconclusivas (n=4) e negativas (n=85) para Salmonella spp. e bioquímicas positivas (n=37) e negativas (n=85) para E. coli. Os perfis de massas foram adquiridos com o espectrômetro de massas MALDI-TOF Autoflex III SmartBeam e os espectros brutos foram processados usando o programa MALDI Biotyper (Bruker Daltonics). De acordo com a identificação preliminar, com base na morfologia das colônias e nas reações bioquímicas, sete isolados foram considerados positivos para Salmonella spp. Através do MALDI Biotyper, esses sete isolados foram classificados como pertencentes ao gênero Salmonella e, além disso, identificados como S. enterica. Quatro isolados que apresentaram características fenotípicas não usuais e resultados inconclusivos nos testes bioquímicos para Salmonella foram identificados como pertencentes aos gêneros Citrobacter e Proteus após análise por MALDI. Para E. coli, 37 amostras foram positivas pelos testes bioquímicos da espécie, o que foi confirmado por MALDI Biotyper. A metodologia MALDI-TOF permitiu a rápida confirmação da identidade de Salmonella spp. e E. coli, podendo ser utilizada para detecção desses microrganismos em isolados bacterianos de carcaças bovinas.


Microbiology ◽  
2011 ◽  
Vol 157 (1) ◽  
pp. 220-233 ◽  
Author(s):  
Bożena Nejman ◽  
Beata Nadratowska-Wesołowska ◽  
Agnieszka Szalewska-Pałasz ◽  
Alicja Węgrzyn ◽  
Grzegorz Węgrzyn

The pathogenicity of Shiga toxin-producing Escherichia coli (STEC) depends on the expression of stx genes that are located on lambdoid prophages. Effective toxin production occurs only after prophage induction, and one may presume that replication of the phage genome is important for an increase in the dosage of stx genes, positively influencing their expression. We investigated the replication of plasmids derived from Shiga toxin (Stx)-converting bacteriophages in starved E. coli cells, as starvation conditions may be common in the intestine of infected humans. We found that, unlike plasmids derived from bacteriophage λ, the Shiga toxin phage-derived replicons did not replicate in amino acid-starved relA + and relA − cells (showing the stringent and relaxed responses to starvation, respectively). The presence of the stable fraction of the replication initiator O protein was detected in all tested replicons. However, while ppGpp, the stringent response effector, inhibited the activities of the λ P R promoter and its homologues from Shiga toxin-converting bacteriophages, these promoters, except for λ P R, were only weakly stimulated by the DksA protein. We suggest that this less efficient (relative to λ) positive regulation of transcription responsible for transcriptional activation of the origin contributes to the inhibition of DNA replication initiation of Shiga toxin-converting bacteriophages in starved host cells, even in the absence of ppGpp (as in starved relA − hosts). Possible clinical implications of these results are discussed.


2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Anastasia Pavelkovich ◽  
Arta Balode ◽  
Petra Edquist ◽  
Svetlana Egorova ◽  
Marina Ivanova ◽  
...  

The spread of carbapenemase-producing Enterobacteriaceae is a global problem; however, no exact data on the epidemiology of carbapenemase in the Baltic countries and St. Petersburg area is available. We aimed to evaluate the epidemiology of carbapenemase-producingEscherichia coliandKlebsiella pneumoniaein the Baltic States and St. Petersburg, Russia, and to compare the different methods for carbapenemase detection. From January to May 2012, allK. pneumoniae  n=1983andE. coli  n=7774clinical isolates from 20 institutions in Estonia, Latvia, Lithuania, and St. Petersburg, Russia were screened for carbapenem susceptibility. The IMP, VIM, GIM, NDM, KPC, and OXA-48 genes were detected using real-time PCR and the ability to hydrolyze ertapenem was determined using MALDI-TOF MS. Seventy-seven strains were found to be carbapenem nonsusceptible. From these, 15K. pneumoniaestrains hydrolyzed ertapenem and carried theblaNDMgene. All of these strains carried integron 1 and most carried integron 3 as well as genes of the CTX-M-1 group. No carbapenemase-producingE. coliorK. pneumoniaestrains were found in Estonia, Latvia, or Lithuania; however, NDM-positiveK. pneumoniaewas present in the hospital in St. Petersburg, Russia. A MALDI-TOF MS-based assay is a suitable and cost-effective method for the initial confirmation of carbapenemase production.


2007 ◽  
Vol 189 (17) ◽  
pp. 6482-6486 ◽  
Author(s):  
Anne-Laure Prunier ◽  
Raymond Schuch ◽  
Reinaldo E. Fernández ◽  
Anthony T. Maurelli

ABSTRACT Comparison of nadA and nadB in 14 Shigella strains and enteroinvasive Escherichia coli versus E. coli showed that at least one locus is altered in all strains. These observations explain the characteristic nicotinic acid auxotrophy of Shigella organisms and are consistent with the previously identified antivirulence nature of these genes for these pathogens.


2019 ◽  
Vol 21 (6) ◽  
pp. 280-283
Author(s):  
Farshad Kakian ◽  
Behnam Zamanzad ◽  
Abolfazle Gholipour ◽  
Kiarash Zamanzad

Background and aims: Carbapenems are the final-line treatments for multidrug-resistant, gram-negative infections. The patterns of resistance to carbapenems among hospital bacterial pathogens vary widely across different hospitals in a country. Considering that Escherichia coli is one of the most important causes of nosocomial infections, it is essential to study its drug resistance. Methods: In this descriptive-analytical study, a total of 80 samples of E. coli isolated from inpatients with urinary tract infections (UTIs) were collected in different wards (i.e., women, urology, infectious, and ICU) of Shahrekord hospitals. After the diagnosis and confirmation of bacteria by standard bacteriological methods, their sensitivity to imipenem and meropenem was investigated by the antibiogram (diskdiffusion) method. Then, the minimum inhibitory concentration (MIC) was determined by the E-test strip according to the Clinical and Laboratory Standards Institute (CLSI) standard. Results: In this study, resistance to meropenem and imipenem by antibiogram (disc diffusion) was observed in 21 (25.26%) and 20 (25%) of the isolates, respectively. Twenty isolates had MIC ≥4 μg/mL for meropenem, 13 isolates demonstrated MIC≥4 μg/mL for imipenem, and 14 isolates had 1≤MIC<4 μg/mL and were semi-sensitive. Conclusion: In general, E. coli had significant resistance to carbapenems. Therefore, rapid and accurate identification of these strains can be a major step to the treatment and control of these strains and prevention of the spread of the resistance.


Author(s):  
Nahid Kondori ◽  
Amra Kurtovic ◽  
Beatriz Piñeiro-Iglesias ◽  
Francisco Salvà-Serra ◽  
Daniel Jaén-Luchoro ◽  
...  

Bloodstream infections (BSIs), the presence of microorganisms in blood, are potentially serious conditions that can quickly develop into sepsis and life-threatening situations. When assessing proper treatment, rapid diagnosis is the key; besides clinical judgement performed by attending physicians, supporting microbiological tests typically are performed, often requiring microbial isolation and culturing steps, which increases the time required for confirming positive cases of BSI. The additional waiting time forces physicians to prescribe broad-spectrum antibiotics and empirically based treatments, before determining the precise cause of the disease. Thus, alternative and more rapid cultivation-independent methods are needed to improve clinical diagnostics, supporting prompt and accurate treatment and reducing the development of antibiotic resistance. In this study, a culture-independent workflow for pathogen detection and identification in blood samples was developed, using peptide biomarkers and applying bottom-up proteomics analyses, i.e., so-called “proteotyping”. To demonstrate the feasibility of detection of blood infectious pathogens, using proteotyping, Escherichia coli and Staphylococcus aureus were included in the study, as the most prominent bacterial causes of bacteremia and sepsis, as well as Candida albicans, one of the most prominent causes of fungemia. Model systems including spiked negative blood samples, as well as positive blood cultures, without further culturing steps, were investigated. Furthermore, an experiment designed to determine the incubation time needed for correct identification of the infectious pathogens in blood cultures was performed. The results for the spiked negative blood samples showed that proteotyping was 100- to 1,000-fold more sensitive, in comparison with the MALDI-TOF MS-based approach. Furthermore, in the analyses of ten positive blood cultures each of E. coli and S. aureus, both the MALDI-TOF MS-based and proteotyping approaches were successful in the identification of E. coli, although only proteotyping could identify S. aureus correctly in all samples. Compared with the MALDI-TOF MS-based approaches, shotgun proteotyping demonstrated higher sensitivity and accuracy, and required significantly shorter incubation time before detection and identification of the correct pathogen could be accomplished.


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