scholarly journals Virulence Genes, Antibiotic Resistance and Phylotyping of Escherichia coli O157 Recovered from Diarrheic Calves

2021 ◽  
Vol 10 (1) ◽  
pp. 1-7

E. coli O157 is one of the main food-borne pathogens that attributed to the attaching and effacing Shigatoxigenic E. coli pathotype (AE-STEC). The occurrence of E. coli O157 in diarrheic calves investigated through molecular detection of rfbEO157 encoding gene was 8.02% within E. coli strains. Detection of AE-STEC virulence genes in E. coli O157 strains using multiplex PCR showed the presence of eae, stx1, stx2 and ehylA in percentages of 93.3, 73.3, 20 and 13.3%, respectively. The virulence genes profile of E. coli O157 revealed the predominance of eae+stx1 combination in 66.7% of these strains. All E. coli O157 strains exhibited antibiotic multi-resistances with higher resistance (100%) to amoxicillin/clavulanic acid, cefalexin, cefuroxime and tetracycline, while the lowest resistance was detected for gentamicin (40%). Phenotypic resistance to extended spectrum cephalosporins (ESCs) indicated that 60% of these strains were resistant to ceftriaxone and cefotaxime, while 53.3% were resistant to cefquinome. Molecular detection of extended spectrum β-lactamases (ESBLs) encoding genes recorded the superiority of blaTEM gene (100%), whereas the blaSHV and blaCTXM genes were detected in percentages of 40 and 20%, respectively. The genetic profiling of resistance genes revealed the role of blaCTXM gene in ESCs resistance as blaTEM+blaSHV+blaCTXM combination was detected only in ESC resistant strains. Finally, B2 phylogroup was the most prevalent one (80%) within E. coli O157 strains. This implicates diarrheic calves as a source of highly pathogenic multi-resistant E. coli O157 strains.

Author(s):  
S. C. Tama ◽  
Y. B. Ngwai ◽  
I. H. Nkene ◽  
R. H. Abimiku

Objectives: The present study reports extended-spectrum beta-lactamase (ESBL) production in E. coli isolates from poultry droppings from selected poultry farms in Keffi, Nigeria. Methods: Seventy-five (75) samples of poultry droppings were collected, and E. coli was isolated using standard microbiological methods. Antibiotic susceptibility testing and minimum inhibitory concentrations were evaluated as described by the Clinical and Laboratory Standards Institute (CLSI). Phenotypic confirmation of ESBL production by the isolates was carried out using double disc synergy test.  Molecular detection of ESBL genes was carried out using Polymerase Chain Reaction (PCR) method. Results: All (100%) samples had E. coli. Antimicrobial resistance in the isolates were as follows: imipenem (12.0%), gentamicin (20.0%), cefoxitin (37.3%), cefotaxime (41.3%), ceftazidime (44.0%), ciprofloxacin (48.0%), amoxicillin/clavulanic acid (58.7%), streptomycin (92.0%),  sulphamethoxazole/trimethoprim (92.0%) and ampicillin (98.7%). Joint resistance to ampicillin, sulphamethoxazole/trimethoprim-streptomycin was the commonest resistance phenotype at 10.6%. Multiple antibiotic resistance (MAR) was observed in 97.3% (73/75) of the isolates; and the most common MAR indices were 0.7 (21.9%), 0.5 (17.8%), 0.4 (16.4%), 0.8 (11.1%) and 0.3 (10.9%). Twenty three (46.9%) of the 49 cefotaxime/ceftazidime isolates were confirmed ESBL producers. Twenty-two of the 23 ESBL positive isolates (95.7%) carried the bla genes as follows: 95.5% (21/22) for blaSHV; 68.2% (15/22) for blaTEM; and 50.0% (11/22) for blaCTX-M. Eleven (50%) of the 22 isolates carried two bla genes (blaSHV and blaCTX-M, blaTEM and blaCTX-M and blaTEM and blaSHV). Conclusion: The E. coli isolates were less resistant to imipenem, gentamicin and cefoxitin; most isolates were MAR, with resistance to 7 antibiotics being the most predominant. In addition, the blaSHV gene was the most common ESBL gene detected in confirmed ESBL-producing E. coli isolates.


2015 ◽  
Vol 309 (12) ◽  
pp. C835-C846 ◽  
Author(s):  
Tarunmeet Gujral ◽  
Anoop Kumar ◽  
Shubha Priyamvada ◽  
Seema Saksena ◽  
Ravinder K. Gill ◽  
...  

Enteropathogenic Escherichia coli (EPEC) is a food-borne pathogen that causes infantile diarrhea worldwide. EPEC decreases the activity and surface expression of the key intestinal Cl−/HCO3− exchanger SLC26A3 [downregulated in adenoma (DRA)], contributing to the pathophysiology of early diarrhea. Little is known about the mechanisms governing membrane recycling of DRA. In the current study, Caco-2 cells were used to investigate DRA trafficking under basal conditions and in response to EPEC. Apical Cl−/HCO3− exchange activity was measured as DIDS-sensitive 125I− uptake. Cell surface biotinylation was performed to assess DRA endocytosis and exocytosis. Inhibition of clathrin-mediated endocytosis by chlorpromazine (60 μM) increased apical Cl−/HCO3− exchange activity. Dynasore, a dynamin inhibitor, also increased function and surface levels of DRA via decreased endocytosis. Perturbation of microtubules by nocodazole revealed that intact microtubules are essential for basal exocytic (but not endocytic) DRA recycling. Mice treated with colchicine showed a decrease in DRA surface levels as visualized by confocal microscopy. In response to EPEC infection, DRA surface expression was reduced partly via an increase in DRA endocytosis and a decrease in exocytosis. These effects were dependent on the EPEC virulence genes espG1 and espG2. Intriguingly, the EPEC-induced decrease in DRA function was unaltered in the presence of dynasore, suggesting a clathrin-independent internalization of surface DRA. In conclusion, these studies establish the role of clathrin-mediated endocytosis and microtubules in the basal surface expression of DRA and demonstrate that the EPEC-mediated decrease in DRA function and apical expression in Caco-2 cells involves decreased exocytosis.


Microbiology ◽  
2005 ◽  
Vol 151 (7) ◽  
pp. 2291-2299 ◽  
Author(s):  
Stefan Fälker ◽  
M. Alexander Schmidt ◽  
Gerhard Heusipp

DNA adenine methyltransferase (Dam) plays an important role in physiological processes of Gram-negative bacteria such as mismatch repair and replication. In addition, Dam regulates the expression of virulence genes in various species. The authors cloned the dam gene of Yersinia enterocolitica and showed that Dam is essential for viability. Dam overproduction in Y. enterocolitica resulted in an increased frequency of spontaneous mutation and decreased resistance to 2-aminopurine; however, these effects were only marginal compared to the effect of overproduction of Escherichia coli-derived Dam in Y. enterocolitica, implying different roles or activities of Dam in mismatch repair of the two species. These differences in Dam function are not the cause for the essentiality of Dam in Y. enterocolitica, as Dam of E. coli can complement a dam defect in Y. enterocolitica. Instead, Dam seems to interfere with expression of essential genes. Furthermore, Dam mediates virulence of Y. enterocolitica. Dam overproduction results in increased tissue culture invasion of Y. enterocolitica, while the expression of specifically in vivo-expressed genes is not altered.


2015 ◽  
Vol 7 (3) ◽  
pp. 272-280 ◽  
Author(s):  
Ifeoma Chinyere UGWU ◽  
Madubuike Umunna ANYANWU ◽  
Chidozie Clifford UGWU ◽  
Ogbonna Wilfred UGWUANYI

This study was conducted to isolate generic extended-spectrum β-lactam (ESBL)-resistant enterobacteria from pigs reared in Enugu State Southeast, Nigeria and determine the antibacterial resistance profile of the isolates. Rectal swabs were collected from 190, randomly selected, apparently healthy pigs. Isolation of ESBL-resistant enterobacteria was done using Mac Conkey agar supplemented with 2 µg/ml of cefotaxime. Phenotypic characterization of the isolates to generic level was done following standard biochemical methods. Phenotypic resistance of the isolates to antibacterial agents was determined using the disc diffusion method. Out of 46 ESBL-resistant enterobacterial isolates, 4 (8.7%) were Escherichia coli, 11 (23.9%) were Salmonella species, while 31 (67.4%) were Klebsiella species. Resistance of the Salmonella isolates was 45.5% to ciprofloxacin, 36.4% to ofloxacin and levofloxacin, 9.1% to norfloxacin, amikacin and gentamicin, 27.3% to streptomycin, 72.7% to chloramphenicol and 90.9% to tetracycline. Resistance of the Klebsiella isolates was 93.5% to ampicillin, 12.9% to ciprofloxacin, 19.4% to ofloxacin and levofloxacin, 9.7% to norfloxacin and streptomycin, 64.5% to chloramphenicol and 38.7% to tetracycline. Resistance of the E. coli isolates was 100% to gentamicin, 75% to ampicillin and streptomycin, 50% to ciprofloxacin, norfloxacin, chloramphenicol and tetracycline, and 25% to ofloxacin, levofloxacin and amikacin. All the isolates were resistant to ceftriaxone, cefotaxime, ceftazidime, cefepime, cefpodoxime, amoxicillin/clavulanic acid and aztreonam. Resistance of the isolates to more than 3 classes of antibacterial agents tested was 54.8% for Klebsiella, 90.9% for Salmonella and 100% for E. coli, respectively. This study has shown that pigs reared in Enugu State Southeast, Nigeria, are colonized by ESBL-resistant Enterobactericeae and are potential reservoirs and disseminators of these organisms.


2020 ◽  
Vol 8 (7) ◽  
pp. 978
Author(s):  
Maria-Theresia Gekenidis ◽  
Anita Kläui ◽  
Kornelia Smalla ◽  
David Drissner

Extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae are classified as serious threats to human health by the U.S. Centers for Disease Control and Prevention. Water used for irrigation of fresh produce can transmit such resistant bacteria directly to edible plant parts. We screened ESBL-producing Escherichia coli, Enterobacter cloacae, and Citrobacter freundii isolated from irrigation water for their potential to transmit resistance to antibiotic-susceptible E. coli. All strains were genome-sequenced and tested in vitro for transmission of resistance to third-generation cephalosporins on solid agar as well as in liquid culture. Of the 19 screened isolates, five ESBL-producing E. coli were able to transfer resistance with different efficiency to susceptible recipient E. coli. Transconjugant strains were sequenced for detection of transferred antibiotic resistance genes (ARGs) and compared to the known ARG pattern of their respective donors. Additionally, phenotypic resistance patterns were obtained for both transconjugant and corresponding donor strains, confirming ESBL-producing phenotypes of all obtained transconjugants.


Author(s):  
Ángel Rodríguez-Villodres ◽  
María Luisa Gil-Marqués ◽  
Rocío Álvarez-Marín ◽  
Rémy A Bonnin ◽  
María Eugenia Pachón-Ibáñez ◽  
...  

Abstract Objectives Escherichia coli is characterized by three resistance patterns to β-lactams/β-lactamase inhibitors (BLs/BLIs): (i) resistance to ampicillin/sulbactam and susceptibility to amoxicillin/clavulanic acid and piperacillin/tazobactam (RSS); (ii) resistance to ampicillin/sulbactam and amoxicillin/clavulanic acid, and susceptibility to piperacillin/tazobactam (RRS); and (iii) resistance to ampicillin/sulbactam, amoxicillin/clavulanic acid and piperacillin/tazobactam (RRR). These resistance patterns are acquired consecutively, indicating a potential risk of developing resistance to piperacillin/tazobactam, but the precise mechanism of this process is not completely understood. Methods Clinical isolates incrementally pressured by piperacillin/tazobactam selection in vitro and in vivo were used. We determined the MIC of piperacillin/tazobactam in the presence and absence of piperacillin/tazobactam pressure. We deciphered the role of the blaTEM genes in the new concept of extended-spectrum resistance to BLs/BLIs (ESRI) using genomic analysis. The activity of β-lactamase was quantified in these isolates. Results We show that piperacillin/tazobactam resistance is induced in E. coli carrying blaTEM genes. This resistance is due to the increase in copy numbers and transcription levels of the blaTEM gene, thus increasing β-lactamase activity and consequently increasing piperacillin/tazobactam MICs. Genome sequencing of two blaTEM-carrying representative isolates showed that piperacillin/tazobactam treatment produced two types of duplications of blaTEM (8 and 60 copies, respectively). In the clinical setting, piperacillin/tazobactam treatment of patients infected by E. coli carrying blaTEM is associated with a risk of therapeutic failure. Conclusions This study describes for the first time the ESRI in E. coli. This new concept is very important in the understanding of the mechanism involved in the acquisition of resistance to BLs/BLIs.


2020 ◽  
Vol 64 (8) ◽  
Author(s):  
Inga Fröding ◽  
Badrul Hasan ◽  
Isak Sylvin ◽  
Maarten Coorens ◽  
Pontus Nauclér ◽  
...  

ABSTRACT Invasive infections due to extended-spectrum-β-lactamase- and pAmpC-producing Escherichia coli (ESBL/pAmpC-EC) are an important cause of morbidity, often caused by the high-risk clone sequence type (ST131) and isolates classified as extraintestinal pathogenic E. coli (ExPEC). The relative influence of host immunocompetence versus microbiological virulence factors in the acquisition and outcome of bloodstream infections (BSI) is poorly understood. Herein, we used whole-genome sequencing on 278 blood culture isolates of ESBL/pAmpC-EC from 260 patients with community-onset BSI collected from 2012 to 2015 in Stockholm to study the association of virulence genes, sequence types, and antimicrobial resistance with severity of disease, infection source, ESBL/pAmpC-EC BSI low-risk patients, and patients with repeated episodes. ST131 subclade C2 comprised 29% of all patients. Factors associated with septic shock in multivariable analysis were patient host factors (hematologic cancer or transplantation and reduced daily living activity), presence of the E. coli virulence factor iss (increased serum survival), absence of phenotypic multidrug resistance, and absence of the genes pap and hsp. Adhesins, particularly pap, were associated with urinary tract infection (UTI) source, while isolates from post-prostate biopsy sepsis had a low overall number of virulence operons, including adhesins, and commonly belonged to ST131 clades A, B, and subclade C1, ST1193, and ST648. ST131 was associated with recurrent episodes. In conclusion, the most interesting finding is the association of iss with septic shock. Adhesins are important for UTI pathogenesis, while otherwise low-pathogenic isolates from the microbiota can cause post-prostate biopsy sepsis.


2006 ◽  
Vol 50 (8) ◽  
pp. 2700-2706 ◽  
Author(s):  
Claudia Mugnaioli ◽  
Francesco Luzzaro ◽  
Filomena De Luca ◽  
Gioconda Brigante ◽  
Mariagrazia Perilli ◽  
...  

ABSTRACT A nationwide survey of extended-spectrum β-lactamase (ESBL) production among Enterobacteriaceae, carried out in 2003, showed that CTX-M-type enzymes have achieved a sizeable prevalence among ESBL producers in Italy, mostly in Escherichia coli and, to a lesser extent, in Klebsiella pneumoniae. In this work, we report on the molecular epidemiology of the CTX-M-producing isolates from that survey and on the mechanisms of dissemination of these emerging resistance determinants. The CTX-M-producing isolates were detected in 10 of the 11 participating centers distributed across the Italian national territory, although at remarkably variable rates in different centers (1.2 to 49.5% of the ESBL producers). All CTX-M determinants were of group 1, with CTX-M-15 and CTX-M-1 being the most prevalent variants (60% and 35%, respectively) and CTX-M-32 carried by a minority (5%) of isolates. Each variant was detected both in E. coli and in K. pneumoniae. Genotyping of the CTX-M-producing isolates by random amplification of polymorphic DNA revealed a notable diversity, especially among those producing CTX-M-1, while clonal expansion was evident with some CTX-M-15-producing strains. Mating experiments revealed a higher overall transferability of bla CTX-M-1 and bla CTX-M-32 than of bla CTX-M-15. Coresistance to quinolones and aminoglycosides was overall higher with the CTX-M-15-producing isolates. The present results indicate that CTX-M-producing strains are now widespread across the Italian territory and underscore the emerging role of these ESBL determinants in the European setting. They also reveal notable differences in the dissemination mechanisms of genes encoding different CTX-M variants of the same lineage.


Author(s):  
S. C. Tama ◽  
Y. B. Ngwai ◽  
G. R. I. Pennap ◽  
I. H. Nkene ◽  
R. H. Abimiku

Aims: This study investigates and reports the production of extended spectrum beta-lactamase in Escherichia coli isolates in poultry droppings sourced from selected poultry farms in Karu, Nigeria Study Design:  Cross sectional study Place and Duration of Study: Department of Microbiology, Nasarawa State University, Keffi, between August 2019 and February 2020. Methodology: Escherichia coli was isolated from the samples using standard cultural and microbiological methods. Antibiotic susceptibility testing and minimum inhibitory concentrations were evaluated as described by the Clinical and Laboratory Standards Institute (CLSI). The detection of ESBL production in E. coli isolates was carried out using double disc synergy test.  In addition, molecular detection of ESBL genes was carried out using Polymerase Chain Reaction (PCR) method. Results: All (100%) samples collected had E. coli. Antibiotic resistances in the isolates in decreasing order were as follows: ampicillin (96.7%), streptomycin (94.4%), sulphamethoxazole /trimethoprim (87.8%), amoxicillin/ clavulanic acid (61.1%), gentamicin (52.2%), ciprofloxacin (40.0%), ceftazidime (35.6%), cefotaxime (31.1%), imipenems (22.2%), cefoxitin (13.3%). The commonest antibiotic resistant phenotype was AMP-SXT-S-CTX-CN (8.8%). Multiple antibiotic resistance (MAR) was observed in 92.2% (83/90) of the isolates with the common MAR indices being 0.5 (26.5%), 0.6 (19.2%), 0.4 (13.2%) and 0.9 (10.8%). Fifty nine of the eighty beta-lactam resistant isolates (73.7%) were confirmed ESBL producers. 55 of the 59 ESBL positive isolates (93.2%) carried bla genes as follows:   blaSHV (50/55, 90.9%), blaTEM (31/55, 56.3%) and blaCTX-M (46/55, 83.6%). Thirty six (65.5%) of the 55 isolates carried two bla genes (blaSHV and blaTEM, blaTEM and blaCTX-M, and blaCTX-M and blaSHV). Conclusion: The E. coli isolates showed lower resistances to cefoxitin, imipenem, cefotaxime, ceftazidime, and ciprofloxacin and most isolates were MAR, with resistance to 5 antibiotics being the most predominant. In addition, blaSHV gene was the most common ESBL gene detected in the confirmed ESBL-producing E. coli isolates.


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