scholarly journals Multiple acquisitions of CTX-M plasmids in the rare D2 genotype of Escherichia coli provide evidence for convergent evolution

Microbiology ◽  
2009 ◽  
Vol 155 (5) ◽  
pp. 1656-1668 ◽  
Author(s):  
Catherine Deschamps ◽  
Olivier Clermont ◽  
Marie Claire Hipeaux ◽  
Guillaume Arlet ◽  
Erick Denamur ◽  
...  

Over the last decade, CTX-M enzymes have become the most prevalent extended-spectrum β-lactamases (ESBLs) worldwide, mostly in Escherichia coli, causing a major health problem. An epidemiological relationship has been established between a rare genotype of E. coli, the D2 genotype, and the presence of CTX-M genes. We investigated this striking association by exploring the genetic backgrounds of 18 D2 genotype CTX-M-producing strains and of the plasmids encoding CTX-M enzymes. The 18 strains had different genetic backgrounds, as assessed by multilocus sequence and O typing, and were associated with various plasmids bearing diverse CTX-M genes. The region encompassing the genetic marker of the D2 genotype (TSPE4.C2) was not correlated with the presence of CTX-M genes. CTX-M-producing D2 strains had far fewer virulence factors than a control group of 8 non-ESBL-producing D2 strains, and an inverse relationship was found between the number of co-resistances associated with the CTX-M gene and the number of virulence factors found in the strain. These findings provide evidence for multiple acquisitions of plasmids carrying CTX-M genes in different D2 genotype strains. They strongly suggest that convergent evolution has occurred, and indicate that there has been selection for the association of a specific genetic background of the strain and the CTX-M gene. This fine-tuning of the relationship between the D2 genotype and CTX-M genes presumably increases the fitness of the strain, indicating a role for the host cell in the acquisition and dissemination of CTX-M genes.

Author(s):  
Luis Alberto Romano ◽  
Virgínia Fonseca Pedrosa

The aim of this study was to determine the relationship between EGC degranulation in fish injected with formalin-killed Escherichia coli and the effect of dexamethasone, diphenhydramine supplied separately and before formalin-killed E. coli. We performed a quantitative analysis of the number of cell granules and demonstrated that: compared to the EGCs of animals, the injection of dead E. coli with formalin generated degranulation of the EGC, while the administration of dexamethasone alone did not show significant differences with control group animals. The administration of diphenhydramine alone did not show significant differences neither with the animals of the dexamethasone treated group nor with those of the control group. When dexamethasone was administered one hour before the E. coli injection, degranulation was apparently inhibited and the number of granules did not show significant differences either with the animals in the control group or with those treated with dexamethasone. Finally, when this group was compared with the group of animals that were only injected with E. coli, the differences were statistically significant. However, when diphenhydramine was administered one hour before E. coli injection, a critical inhibition of EGC degranulation was evidenced, with a marked increase in the number of granules. All this seems to show that dexamethasone can partially inhibit the release of substances that participate in the inflammatory process. Diphenhydramine, a recognized antihistamine, inhibited degranulation of EGCs. These results suggest that EGC can release histamine like mammalian mast cells.


2011 ◽  
Vol 26 (2) ◽  
pp. 144-148
Author(s):  
Eliana Maria Ferreira Gouveia ◽  
Iandara Schettert Silva ◽  
Gerson Nakazato ◽  
Flábio Ribeiro de Araujo ◽  
Marilene Rodrigues Chang

PURPOSE: To verify the possibility of an experimental infection with enteropathogenic Escherichia coli and to confirm by PCR that the symptoms manifested after infection were due to the virulence factors of the studied bacteria. METHODS: Experimental units were 14 healthy pups of Boxer breed, aged 60 days. The animals were divided into three groups. One animal from each litter was included in a control group and the remaining animals were divided into two groups: one inoculated with strain 4083, and another one inoculated with strain SPA14. Gelatinous capsules coated with enteric-coating solution were used for the inoculation of strains. E. coli isolation from feces was performed for all tested animals, and the extracted DNA was subjected to Polymerase Chain Reaction (PCR). RESULTS: All infected animals presented diarrhea and had the gene eae amplified by PCR. CONCLUSION: The efficiency of PCR for the studied strains indicates that this technique can be recommended for the diagnosis of enteropathogenic Escherichia coli as a differential from other pathogens causing diarrhea. It may also be used in the future to verify whether other virulence factors (bfpA gene and EAF plasmid) persist after infection and to assess the pathogenicity of these bacteria.


2012 ◽  
Vol 61 (2) ◽  
pp. 105-110
Author(s):  
BEATA SOBIESZCZAŃSKA ◽  
URSZULA KASPRZYKOWSKA ◽  
MICHAŁ TURNIAK ◽  
HENRYK MACIEJEWSKI ◽  
ROMAN FRANICZEK ◽  
...  

The association between Escherichia coli virulence factors and chronic intestinal disorders is mostly unknown. The presented study compared the distribution of virulence genes and phylogroups among E. coli isolated from chronic intestinal disorders such as Crohn's disease and irritable bowel syndrome (IBS) with strains isolated from patients with acute diarrhea as a control group. The presence of 159 virulence genes corresponding to known E. coli pathotypes was determined among 78 E. coli archive strains isolated from IBS, acute diarrhea and Crohn's disease using CGH microarray. E. coli isolated from IBS demonstrated a mosaic of virulence genes specific to enteropathogenic, enterotoxigenic, enterohemorrhagic E. coli strains and Shigella species. In contrast, virulence factors and phylogroups distribution among E. coli isolated from children with acute diarrhea was similar to extraintestinal E. coli strains that probably acquired some virulence genes. The acquisition of virulence genes might have an impact on diarrheagenic potential of these strains. On the other hand, E. coli isolated from children with Crohn's disease seem to be similar to adherent-invasive E. coli strains (AIEC), as it lack most known virulence genes. The presented study showed that these analyzed groups of E. coli strains differed from each other with the respect to the distribution of virulence genes. The differences in gene content support the idea that the participation of E. coli in chronic intestinal diseases is mostly related to virulence potential of these strains.


2021 ◽  
Author(s):  
Lívia Mendonça Pascoal ◽  
Sarah Rodrigues Chagas ◽  
Francisco J. Pallarés ◽  
Juan J. Quereda ◽  
Juan Manuel Herrero Medrano ◽  
...  

Abstract Background: The present study aims to evaluate the efficacy of an intramuscular multivalent Escherichia coli vaccine for suckling piglets against infection not only by pathogenic E. coli but also by pathogens involved in Porcine Enteric Disease Complex (PEDC). Vaccinated Group had piglets vaccinated at days 10 and 20 of life with Colidex-C® (Vetia Animal Health, Spain), and Control Group had piglets that received sterile saline solution injection at the same days of life. We collected fecal samples in the farm from animals presenting diarrhea and intestinal mucosa swabs and ileum and colon tissue at slaughter and then performed PCR to identify E. coli virulence factors genes. Furthermore, we performed PCR to identify Lawsonia intracellularis, Brachyspira hyodisenteriae, and Salmonella spp.Results: Regarding fecal samples, 0% from Vaccinated Group was positive for E. coli, while Control Group had 94.1% of positive samples (p<0.0001). With respect to intestinal mucosa swab, 0% of the samples from Vaccinated Group were positive for E. coli, while 100% from Control Group were positive (p=0.001). Regarding ileum and colon tissue samples, 35% were positive for E. coli in Vaccinated Group and 85% in Control Group (p=0.001); Gcnt had a higher frequency of F41 (p=0.018), LT (p=0.018) and Sta (p=0.028) virulence factors genes. No sample was positive for Salmonella spp. nor for B. hyodisenteriae, but there were positive samples L. intracellularis; real-time PCR was performed and the frequencies found were 40% and 20% of ileum and colon positive samples in Vaccinated Group and 100% for ileum and 70% for colon in Control Group (p<0.001 for ileum and p=0.001 for colon).Conclusion: The results indicate that the E. coli vaccine for piglets may be a strategy to control E. coli infection. E. coli vaccines emerge as a probable strategy to help control L. intracellularis and, maybe, other enteric pathogens of pigs not evaluated in this study.


2001 ◽  
Vol 8 (1) ◽  
pp. 143-149 ◽  
Author(s):  
Ulla Niewerth ◽  
Andreas Frey ◽  
Thomas Voss ◽  
Chantal Le Bouguénec ◽  
Georg Baljer ◽  
...  

ABSTRACT Pathogenic Escherichia coli strains are known to cause edema disease (ED) and postweaning diarrhea (PWD) in piglets. Although the exact mechanisms of pathogenicity that lead to ED-PWD remain to be elucidated, E. coli-borne Shiga-like toxin and adhesion-mediating virulence factors such as F18 adhesin or F4 fimbriae are believed to play a central role in ED-PWD. In light of these observations we investigated whether another E. coliadhesin, the plasmid-encoded AIDA (adhesin involved in diffuse adherence) might also be present in ED-PWD-causing E. coli isolates. For rapid screening for the AIDA system in large numbers of isolates, a multiplex PCR method along with a duplex Western blot procedure was developed. When screening 104 strains obtained from pigs with or without ED-PWD, we observed a high prevalence of the AIDA operon in porcine E. coli isolates, with over 25% of all strains being AIDA positive, and we could demonstrate a significant association of the intact AIDA gene (orfB) with ED-PWD, while defects in orfB were associated with the absence of disease. Although our data hint toward a contribution of AIDA to ED-PWD, further studies will be necessary since the presence of the AIDA genes was also associated with the presence of the Shiga-like toxin and F18 adhesin genes, two reported virulence factors for ED-PWD.


2011 ◽  
Vol 80 (2) ◽  
pp. 493-505 ◽  
Author(s):  
Patrick D. Vigil ◽  
Travis J. Wiles ◽  
Michael D. Engstrom ◽  
Lev Prasov ◽  
Matthew A. Mulvey ◽  
...  

ABSTRACTUropathogenicEscherichia coli(UPEC) is responsible for the majority of uncomplicated urinary tract infections (UTI) and represents the most common bacterial infection in adults. UPEC utilizes a wide range of virulence factors to colonize the host, including the novel repeat-in-toxin (RTX) protein TosA, which is specifically expressed in the host urinary tract and contributes significantly to the virulence and survival of UPEC.tosA, found in strains within the B2 phylogenetic subgroup ofE. coli, serves as a marker for strains that also contain a large number of well-characterized UPEC virulence factors. The presence oftosAin anE. coliisolate predicts successful colonization of the murine model of ascending UTI, regardless of the source of the isolate. Here, a detailed analysis of the function oftosArevealed that this gene is transcriptionally linked to genes encoding a conserved type 1 secretion system similar to other RTX family members. TosA localized to the cell surface and was found to mediate (i) adherence to host cells derived from the upper urinary tract and (ii) survival in disseminated infections and (iii) to enhance lethality during sepsis (as assessed in two different animal models of infection). An experimental vaccine, using purified TosA, protected vaccinated animals against urosepsis. From this work, it was concluded that TosA belongs to a novel group of RTX proteins that mediate adherence and host damage during UTI and urosepsis and could be a novel target for the development of therapeutics to treat ascending UTIs.


2015 ◽  
Vol 78 (5) ◽  
pp. 1018-1023 ◽  
Author(s):  
MEILI XI ◽  
QIAN WU ◽  
XIN WANG ◽  
BAOWEI YANG ◽  
XIAODONG XIA ◽  
...  

Extended-spectrum β-lactamase (ESBL)–producing Escherichia coli strains have been reported worldwide; however, the incidence and characterization of foodborne ESBL-producing E. coli strains have been rarely reported in the People's Republic of China. Among a collection of 659 E. coli isolates recovered from retail foods in Shaanxi Province, People's Republic of China, 223 cefoxitin-resistant and/or cefoperazone-resistant isolates were screened for ESBL production with the double disk diffusion test. The ESBL-producing isolates were characterized for antimicrobial resistance and the presence of blaTEM, blaSHV, and blaCTX-M genes. Isolates with blaCTX-M were further classified by PCR as having blaCTX-M-1, blaCTX-M-2, blaCTX-M-8, blaCTX-M-9, or blaCTX-M-25. One hundred forty-seven isolates were identified as ESBL positive. PCR detection revealed that 146 isolates (99.3%) contained the blaCTX-M gene. Among these isolates, 42 (28.8%) were positive for the enzyme CTX-M-1, 5 (3.4%) for CTX-M-2, and 99 (67.8%) for CTX-M-9. No CTX-M-8 and CTX-M-25 were found in this study. One hundred fifteen isolates (78.2%) were positive for the blaTEM gene, but blaSHV was not detected. Among the 147 ESBL-producing E. coli isolates, 75 (51.0%), 35 (23.8%), and 4 (2.7%) isolates were positive for blaTEM and blaCTX-M-9, blaTEM and blaCTX-M-1, and blaTEM and blaCTX-M-2, respectively. All of the 147 ESBL-producing isolates were resistant to three or more non–β-lactam antibiotics. This study provides evidence that foodborne E. coli can harbor ESBL-encoding genes. Thus, food could be a vehicle for the dissemination of ESBL-producing E. coli strains, a situation that requires surveillance and appropriate management strategies.


Author(s):  
Mehrdad Halaji ◽  
Shahrzad Shahidi ◽  
Behrooz Ataei ◽  
Abdolamir Atapour ◽  
Awat Feizi ◽  
...  

Abstract Background This study aimed to investigate the phylogenetic characterization and virulence traits of uropathogenic Escherichia coli (UPEC) isolated from kidney transplant patients (KTPs) as well as non-KTPs and analyze the clonal distribution of Extended spectrum β-lactamases (ESBLs)-producing UPEC containing blaCTX-M gene. Methods To this end, we determined virulence marker and the phylogenetic characterization of UPEC in non-KTPs (n = 65) and KTPs (n = 46). The non-KTPs were considered the control group of the study. Also, according to the Achtman scheme, we performed multilocus sequence typing to assess the relationship between twenty-nine of ESBL-producing isolates containing blaCTX-M gene. Results According to the results of PCR assay, the prevalence of virulence factor genes ranged from 0% (cnf and papG III) to 93.7% (fimH). Also, KTP isolates significantly differed from non-KTP isolates only in terms of the prevalence of pap GI elements. Moreover, the most frequent UPEC isolates were in phylogenetic group B2, followed by group D (18.9%), and group A (13.5%). Furthermore, except for phylogenetic group C, there was no significant correlation between phylogenetic distribution in KTPs and non-KTPs. Additionally, MLST analysis of blaCTX-M carrying isolates identified 18 unique sequence types (ST) the most common of which was ST131 (24.1%), followed by ST1193 (10.3%), while fourteen STs were detected only once. Conclusions The results further revealed significant differences between the UPEC isolates from KTPs and non-KTPs regarding the phylogroups C and PAI gene. Based on MLST analysis, we also observed a relatively high diversity in UPEC isolates obtained from KTPs and non-KTPs. Moreover, clonal complex (CC) 131 and ST131 were found to be the most prevalent clones and ST types, respectively. Besides, for the first time, ST8503 were reported in KTPs. These results suggested regular studies on characterization of UPEC isolates among KTPs.


2020 ◽  
Vol 19 (2) ◽  
pp. 84-93
Author(s):  
Ika Dharmayanti ◽  
Dwi Hapsari Tjandrarini

ABSTRACT  Diarrhea is a major health problem in Indonesia with high morbidity and mortality rates. Unhealthy environment and unhygienic behavior are closely related to diarrhea disease. This study aims to identify the association between environmental conditions and behavior with the occurrence of diarrhea in Jawa and Bali. Data source used was the integration data of March’s Susenas and Riskesdas 2018. A logistic regression analysis was chosen to elicit the relationship between sanitation and drinking water facilities, open defecation practice, and other factors with the prevalence of diarrhea. The results showed that open defecation (OR = 1.2; 95% CI: 1.12 to 1.29; P<0.001, and improper of household sanitation and drinking water (OR = 1.11; 95% CI: 1.04 to 1.2; P = 0.003) had significant association with diarrhea. Other factors are age 0-5 years (OR = 1.56; 95% CI: 1.46 to 1.66; P <0,001) and low education (OR = 1.33; 95% CI: 1.21 to 1.47; P <0,001). This study shows the hygienic behavior is the essential factors to reduce the incidence of diarrhea. Therefore, it is recommended to to prioritize aspects of behavior and environmental health, namely changing people’s behavior to defecate in a latrine, and provide proper sanitation and sufficient drinking water. Keywords: Diarrhea; sanitation; drinking water; open defecation   ABSTRAK Penyakit diare merupakan masalah kesehatan utama di Indonesia dengan angka kesakitan dan kematian yang masih tinggi. Lingkungan yang tidak sehat dan perilaku tidak higienis sangat erat kaitannya dengan penyakit diare. Penelitian ini bertujuan untuk menganalisis hubungan antara kondisi lingkungan dan perilaku dengan penyakit diare di pulau Jawa dan Bali. Sumber data yang digunakan adalah data integrasi Susenas Maret dan Riskesdas 2018. Analisis dilakukan dengan menggunakan regresi logistik untuk melihat hubungan antara ketersediaan sanitasi dan air minum, perilaku buang air besar serta faktor lainnya terhadap kejadian diare. Hasil menunjukkan bahwa faktor perilaku buang air besar sembarangan (OR = 1,2; 95% CI: 1,12 - 1,29; P <0,001) serta akses sanitasi dan air minum rumah tangga tidak layak/tidak tersedia (OR = 1,11; 95% CI: 1,04 - 1,2; P = 0,003) memiliki hubungan dengan kejadian diare. Faktor lainnya yaitu: usia 0-5 tahun (OR = 1,56; 95% CI: 1,46 - 1,66; P <0,001) dan pendidikan rendah (OR = 1,33; 95% CI: 1,21 - 1,47; P <0,001).  Penelitian ini menunjukkan bahwa perilaku higienis sangat penting untuk menurunkan kejadian diare. Oleh karena itu direkomendasikan untuk mengutamakan aspek perilaku dan kesehatan lingkungan, yaitu merubah perilaku masyarakat untuk BAB di jamban, serta menyediakan sanitasi dan air minum yang layak. Kata kunci: Diare, sanitasi, sarana air minum, buang air besar sembarangan


2020 ◽  
Vol 13 (2) ◽  
pp. 360-363
Author(s):  
Shikha Tamta ◽  
Obli Rajendran Vinodh Kumar ◽  
Shiv Varan Singh ◽  
Bommenahalli Siddaramiah Pruthvishree ◽  
Ravichandran Karthikeyan ◽  
...  

Background and Aim: Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli are gradually increasing worldwide and carry a serious public threat. This study aimed to determine the antimicrobial resistance pattern of ESBL-producing E. coli isolated from fecal samples of piglets and pig farm workers. Materials and Methods: Fecal samples from <3-month-old piglets (n=156) and farm workers (n=21) were processed for the isolation of ESBL-producing E. coli in MacConkey agar added with 1 μg/mL of cefotaxime. E. coli (piglets=124; farm workers=21) were tested for ESBL production by combined disk method and ESBL E-strip test. Each of the ESBL-positive isolate was subjected to antibiotic susceptibility testing. The ESBL-producing E. coli were further processed for genotypic confirmation to CTX-M gene. Results: A total of 55 (44.4%, 55/124) and nine (42.9%, 9/21) ESBL-producing E. coli were isolated from piglets and farm workers, respectively. Antibiotic susceptibility testing of the ESBL-positive E. coli isolates from piglets and farm workers showed 100% resistance to ceftazidime, cefotaxime, cefotaxime/clavulanic acid, ceftazidime/clavulanic acid, and cefpodoxime. A proportion of 100% (55/55) and 88.9% (8/9) ESBL-positive E. coli were multidrug resistance (MDR) in piglets and farm workers, respectively. On genotypic screening of the ESBL E. coli isolated from piglets (n=55), 15 were positive for the blaCTX-M gene and of the nine ESBL E. coli from farm workers, none were positive for the blaCTX-M gene. Conclusion: Although there was no significant difference in isolation of ESBL-producing E. coli between piglets and farm workers, the ESBL-positive E. coli from piglets showed relatively higher MDR than farm workers.


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