scholarly journals Development of a Tetracycline Resistant Strain of E. coli Sensitive to Ultraviolet Radiation

2014 ◽  
Vol 3 (1) ◽  
pp. 63-68
Author(s):  
Meredith Joy Reesor ◽  
Isaac Joseph King ◽  
Jeffrey Copeland
Keyword(s):  
Escherichia Coli ◽  
Protein Synthesis ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Resistant Strain ◽  
Bacterial Infections ◽  
Present Report ◽  
Medical Community ◽  
Protein Synthesis Inhibitors ◽  
E Coli

Multidrug resistance bacteria pose a significant threat to human health and the efforts of the medical community.  Given our reliance on antibiotics for therapeutic treatment of bacterial infections it is imperative to understand the mechanism by which bacteria develop antibiotic resistance.  In the present report we develop a strain of Escherichia coli capable of resisting high levels of tetracycline and other protein synthesis inhibitors.  Furthermore the tetracycline resistant strain is approximately 1/3rd in length and is sensitive to UV radiation.

scholarly journals Increased Survival of Antibiotic-Resistant Escherichia coli inside Macrophages

2012 ◽  
Vol 57 (1) ◽  
pp. 189-195 ◽  
Author(s):  
Migla Miskinyte ◽  
Isabel Gordo
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Bacterial Infections ◽  
Resistance Mutation ◽  
Fitness Cost ◽  
Resistance Mutations ◽  
Content Type ◽  
E Coli ◽  
Fitness Effects ◽  
K 12

ABSTRACTMutations causing antibiotic resistance usually incur a fitness cost in the absence of antibiotics. The magnitude of such costs is known to vary with the environment. Little is known about the fitness effects of antibiotic resistance mutations when bacteria confront the host's immune system. Here, we study the fitness effects of mutations in therpoB,rpsL, andgyrAgenes, which confer resistance to rifampin, streptomycin, and nalidixic acid, respectively. These antibiotics are frequently used in the treatment of bacterial infections. We measured two important fitness traits—growth rate and survival ability—of 12Escherichia coliK-12 strains, each carrying a single resistance mutation, in the presence of macrophages. Strikingly, we found that 67% of the mutants survived better than the susceptible bacteria in the intracellular niche of the phagocytic cells. In particular, allE. colistreptomycin-resistant mutants exhibited an intracellular advantage. On the other hand, 42% of the mutants incurred a high fitness cost when the bacteria were allowed to divide outside of macrophages. This study shows that single nonsynonymous changes affecting fundamental processes in the cell can contribute to prolonged survival ofE. coliin the context of an infection.

Escherichia coli Strains Isolated from Retail Meat Products: Evaluation of Biofilm Formation Ability, Antibiotic Resistance, and Phylogenetic Group Analysis

2020 ◽  
Vol 83 (2) ◽  
pp. 233-240
Author(s):  
ELENA BARILLI ◽  
ALICE VISMARRA ◽  
VIVIANA FRASCOLLA ◽  
MARTINA REGA ◽  
CRISTINA BACCI
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Health Risk ◽  
Phylogenetic Group ◽  
Animal Origin ◽  
Potential Health ◽  
Potential Health Risk ◽  
E Coli ◽  
Retail Meat

ABSTRACT Escherichia coli is a ubiquitous organism capable of forming a biofilm. This is an important virulence factor and is critical in certain diseases and in the development of antibiotic resistance, which is increased by biofilm synthesis. In the present study, the potential health risk associated with handling and consumption of foods of animal origin contaminated with E. coli–producing biofilm was evaluated. We analyzed the ability of 182 E. coli strains isolated from pork, poultry, and beef, purchased in three different supermarkets in the area of the “Italian Food Valley” (Parma, northern Italy), to form biofilms. Positive strains were also tested for the presence of 12 biofilm-associated genes. Moreover, the 182 E. coli were characterized for antibiotic resistance, presence of multidrug resistance, extended-spectrum β-lactamase strains, and phylogenetic diversity through PCR. Twenty-five percent of the isolates produced biofilm. The majority showed weak adherence, five were moderate, and three were strong producers. E. coli with a strong adherence capability (three of three) harbored eight biofilm-associated genes, while weak and moderate producers harbored only five (frequencies ranging from 80 to 100%). Multidrug resistance was observed in 20 biofilm-producing E. coli, and 15 of these belonged to phylogenetic group D. Among nonbiofilm producers, the percentage of strains belonging to phylogenetic groups B2 and D was approximately 40%, highlighting a potential health risk for consumers and people handling contaminated products. The present study underlines the importance of monitoring the prevalence and characteristics of E. coli contaminating retail meat in relation to the potential virulence highlighted here. HIGHLIGHTS

scholarly journals Antibiotic resistance and virulence genes of extraintestinal pathogenic Escherichia coli from tropical estuary, south India

2015 ◽  
Vol 9 (05) ◽  
pp. 496-504 ◽  
Author(s):  
Divya Sukumaran ◽  
Abdulla A Mohamed Hatha
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Virulence Factor ◽  
Virulence Genes ◽  
Antimicrobial Agents ◽  
Diffusion Method ◽  
Disk Diffusion Method ◽  
E Coli ◽  
Virulence Factor Genes

Introduction: Escherichia coli strains can cause a variety of intestinal and extraintestinal diseases. Extraintestinal pathogenic E. coli (ExPEC) strains have the ability to cause severe extraintestinal infections. Multidrug resistance among ExPEC could complicate human infections. Methodology: Escherichia coli strains were isolated during the period of January 2010 to December 2012 from five different stations set at Cochin estuary. Susceptibility testing was determined by the disk-diffusion method using nine different antimicrobial agents. A total of 155 strains of Escherichia coli were screened for the presence of virulence factor genes including papAH, papC, sfa/focDE, iutA,and kpsMT II associated with ExPEC. Results: Among the 155 E. coli isolates, 26 (16.77%), carried two or more virulence genes typical of ExPEC. Furthermore, 19.23% of the ExPEC isolates with multidrug resistance were identified to belong to phylogenetic groups B2 and D. Statistically significant association of iutA gene in ExPEC was found with papC (p < 0.001) and kpsMT II (p < 0.001) genes. ExPEC isolates were mainly resistant to ampicillin (23.07%), tetracycline (19.23%), co-trimoxazole (15.38%), and cefotaxime (15.38%). The adhesion genes papAH and sfa/focDE were positively associated with resistance to gentamicin, chloramphenicol, and cefotaxime (p < 0.05). Conclusions: Co-occurrence of virulence factor genes with antibiotic resistance among ExPEC poses considerable threat to those who use this aquatic system for a living and for recreation.

Commensal Escherichia coli of healthy humans: a reservoir for antibiotic-resistance determinants

2010 ◽  
Vol 59 (11) ◽  
pp. 1331-1339 ◽  
Author(s):  
Jannine K. Bailey ◽  
Jeremy L. Pinyon ◽  
Sashindran Anantham ◽  
Ruth M. Hall
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Resistance Genes ◽  
Resistant Strain ◽  
Healthy Adults ◽  
Susceptible Strain ◽  
E Coli ◽  
Resistance Determinants ◽  
Healthy Humans ◽  
Depth Analysis

This study examined in detail the population structure of Escherichia coli from healthy adults with respect to the prevalence of antibiotic resistance and specific resistance determinants. E. coli isolated from the faeces of 20 healthy adults not recently exposed to antibiotics was tested for resistance to ten antibiotics and for carriage of integrons and resistance determinants using PCR. Strain diversity was assessed using biochemical and molecular criteria. E. coli was present in 19 subjects at levels ranging from 2.0×104 to 1.7×108 c.f.u. (g faeces)−1. Strains resistant to one to six antibiotics were found at high levels (>30 %) in only ten individuals, but at significant levels (>0.5 %) in 14. Resistant isolates with the same phenotype from the same individual were indistinguishable, but more than one susceptible strain was sometimes found. Overall, individuals harboured one to four E. coli strains, although in 17 samples one strain was dominant (>70 % of isolates). Eighteen strains resistant to ampicillin, sulfamethoxazole, tetracycline and trimethoprim in 15 different combinations were observed. One resistant strain was carried by two unrelated individuals and a susceptible strain was shared by two cohabiting subjects. Two minority strains were derivatives of a more abundant resistant strain in the same sample, showing that continuous evolution is occurring in vivo. The trimethoprim-resistance genes dfrA1, dfrA5, dfrA7, dfrA12 or dfrA17 were in cassettes in a class 1 or class 2 integron. Ampicillin resistance was conferred by the bla TEM gene, sulfamethoxazole resistance by sul1, sul2 or sul3 and tetracycline resistance by tetA(A) or tetA(B). Chloramphenicol resistance (cmlA1 gene) was detected only once. Phylogenetic groups A and B2 were more common than B1 and D. Commensal E. coli of healthy humans represent an important reservoir for numerous antibiotic-resistance genes in many combinations. However, measuring the true extent of resistance carriage in commensal E. coli requires in-depth analysis.

scholarly journals The Wide Range of Antibiotic Resistance and Variability of Genotypic Profiles in Escherichia coli from Domestic Animals in Eastern Sicily

Antibiotics ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 28
Author(s):  
Nunziatina Russo ◽  
Alessandro Stamilla ◽  
Giuseppe Cascone ◽  
Cinzia Lucia Randazzo ◽  
Antonino Messina ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Domestic Animals ◽  
Antibiotic Resistant ◽  
E Coli ◽  
Antibiotic Resistance Profile ◽  
Wide Range ◽  
Resistance Patterns ◽  
Antibiotic Resistance Patterns

The emergence of multidrug resistance among Enterobacteriaceae in livestock poses a serious public health threat. Escherichia coli, a usual host of intestinal microbiota, is recognized also as etiological agent of numerous infections widespread in both humans and animals. The colibacillosis is one of the most reported zoonoses worldwide, typically treated with antibiotics in the primary stages. This strategy has promoted the onset of antibiotic-resistant serotypes of E. coli, reducing the effectiveness of therapeutic treatments and contributing to antibiotic resistance spread. The current study focused on biodiversity, pathogenicity, and antibiotic resistance profile of 104 E. coli strains isolated from domestic animals in Eastern Sicily. The strains were isolated from sick animals and carcasses of six different animal species and screened for resistance against 16 antibiotic molecules, as recommended by WHO and OIE. The antibiotic resistance patterns highlighted that all strains were multi-resistant, showing resistance to at least three antibiotic classes. The highest incidence of resistance was observed against amoxicillin (100%), tylosin (97%), sulfamethoxazole (98%), and erythromycin (92%), while the lowest for colistin (8%). The pathotype characterization identified two EPEC strains and the study of genetic linkage (PFGE) showed a wide variety of profiles. The current study emphasized the wide range of multidrug resistance and genotyping profiles in E. coli isolated in Easter Sicily.

scholarly journals Limited and strain-specific transcriptional and growth responses to acquisition of a multidrug resistance plasmid in genetically diverse Escherichia coli lineages

2020 ◽  
Author(s):  
Steven J. Dunn ◽  
Laura Carrilero ◽  
Michael Brockhurst ◽  
Alan McNally
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Resistance Genes ◽  
Antibiotic Resistance Genes ◽  
Growth Responses ◽  
Fitness Costs ◽  
Transcriptional Responses ◽  
E Coli ◽  
Resistance Plasmid

AbstractMulti-drug resistant (MDR) Escherichia coli are a major global threat to human health, wherein multi-drug resistance is primarily spread by MDR plasmid acquisition. MDR plasmids are not widely distributed across the entire E. coli species, but instead are concentrated in a small number of clones. Here, we test if diverse E. coli strains vary in their ability to acquire and maintain MDR plasmids, and if this relates to their transcriptional response following plasmid acquisition. We used strains from across the diversity of E. coli, including the common MDR lineage ST131, and the IncF plasmid, pLL35, encoding multiple antibiotic resistance genes. Strains varied in their ability to acquire pLL35 by conjugation, but all were able to stably maintain the plasmid. The effects of pLL35 acquisition on cefotaxime resistance and growth also varied among strains, with growth responses ranging from a small decrease to a small increase in growth of the plasmid-carrier relative to the parental strain. Transcriptional responses to pLL35 acquisition were limited in scale and highly strain specific. We observed significant transcriptional responses at the operon or regulon level, possibly due to stress responses or interactions with resident MGEs. Subtle transcriptional responses consistent across all strains were observed affecting functions, such as anaerobic metabolism, previously shown to be under negative frequency dependent selection in MDR E. coli. Overall there was no correlation between the magnitude of the transcriptional and growth responses across strains. Together these data suggest that fitness costs arising from transcriptional disruption are unlikely to act as a barrier to MDR plasmid dissemination in E. coli.ImportancePlasmids play a key role in bacterial evolution by transferring niche adaptive functions between lineages, including driving the spread of antibiotic resistance genes. Fitness costs of plasmid acquisition arising from the disruption of cellular processes could limit the spread of multidrug resistance plasmids. However, the impacts of plasmid acquisition are typically measured in lab-adapted strains rather than in more ecologically relevant natural isolates. Using a clinical multidrug resistance plasmid and a diverse collection of E. coli strains isolated from clinical infections and natural environments, we show that plasmid acquisition had only limited and highly strain-specific effects on bacterial growth and transcription. These findings suggest that fitness costs arising from transcriptional disruption are unlikely to act as a barrier to plasmid transmission in natural populations of E. coli.

scholarly journals Multidrug Resistance following Expression of the Escherichia coli marA Gene in Mycobacterium smegmatis

1998 ◽  
Vol 180 (11) ◽  
pp. 2995-2998 ◽  
Author(s):  
Patrick F. McDermott ◽  
David G. White ◽  
Isabelle Podglajen ◽  
Michael N. Alekshun ◽  
Stuart B. Levy
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Mycobacterium Smegmatis ◽  
Antimicrobial Agents ◽  
Regulatory System ◽  
Mutant Protein ◽  
Multiple Antibiotic Resistance ◽  
Alpha Helices ◽  
E Coli

ABSTRACT Expression of the Escherichia coli multiple antibiotic resistance marA gene cloned in Mycobacterium smegmatis produced increased resistance to multiple antimicrobial agents, including rifampin, isoniazid, ethambutol, tetracycline, and chloramphenicol. Cloned marR or marA cloned in the antisense direction had no effect. Resistance changes were lost with spontaneous loss of the plasmid bearing marA. A MarA mutant protein, having an insertional mutation within either of its two alpha-helices of the first putative helix-turn-helix domain, failed to produce the multiresistance phenotype in E. coli andM. smegmatis, indicating that this region is critical for MarA function. These results strongly suggest that E. coli marA functions in M. smegmatis and that amar-like regulatory system exists in this organism.

scholarly journals Susceptibility to antibiotics in escherichiae isolated in a multidisciplinary medical centre

2016 ◽  
Vol 65 (4) ◽  
pp. 83-89
Author(s):  
Nadezda S. Kozlova ◽  
Natalia E. Barantsevich ◽  
Elena P. Barantsevich
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Antimicrobial Resistance ◽  
Antimicrobial Agents ◽  
E Coli ◽  
Microdilution Method ◽  
Carbapenem Resistant ◽  
Resistant Strains ◽  
High Level

Relevance. Antimicrobial resistance in nosocomial strains currently presents a very important problem.  Aim of the study: Study of antibiotic resistance in Escherichia coli, isolated in a multidisciplinary centre.  Materials and Methods. Susceptibility of 151 E. coli strains to 15 antibiotics was studied by microdilution method. Results. The majority of the studied strains were resistant to antibiotics, including: ampicillin (57.0%), ciprofloxacin and moxifloxacin (42.4% each), III and IV generation cephalosporins (37.1% and 34.4%, respectively) and gentamycin (29.1%). The highest activity against E. coliwas shown for carbapenems (resistance to erthapenem – 2.6%, meropenem – 0.7%), in particular, for imipenem – no strains resistant to this drug were isolated. Resistance to amikacin and phosphomycin was low: 3.3% and 1.3% respectively. Wide diversity of antibiotic resistance spectra was revealed in studied strains, with a high level of multidrug resistance (48.0%). Conclusion. Study of susceptibility to antimicrobial agents in E. coli, isolated in a multidisciplinary centre, showed predominance of resistant strains with a high level of multidrug resistance. The appearance of carbapenem-resistant strains in a multidisciplinary centre presents a rising problem.

scholarly journals Antimicrobial resistance in fecal Escherichia coli and Salmonella enterica isolates: a two-year prospective study of small poultry flocks in Ontario, Canada

2019 ◽  
Vol 15 (1) ◽  
Author(s):  
Csaba Varga ◽  
Michele T. Guerin ◽  
Marina L. Brash ◽  
Durda Slavic ◽  
Patrick Boerlin ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Multidrug Resistance ◽  
Bacterial Infections ◽  
Animal Health ◽  
Enteric Bacteria ◽  
Positive Sample ◽  
Resistance Pattern ◽  
Resistant Bacteria ◽  
E Coli ◽  
Game Bird

Abstract Background Although keeping small poultry flocks is increasingly popular in Ontario, information on the antimicrobial susceptibility of enteric bacteria of such flocks is lacking. The current study was conducted on small poultry flocks in Ontario between October 2015 and September 2017, and samples were submitted on a voluntary basis to Ontario’s Animal Health Laboratory. From each submission, a pooled cecal sample was obtained from all the birds of the same species from the same flock and tested for the presence of two common enteric pathogens, E. coli and Salmonella. Three different isolates from each E. coli-positive sample and one isolate from each Salmonella-positive sample were selected and tested for susceptibility to 14 antimicrobials using a broth microdilution technique. Results A total of 433 fecal E. coli isolates (358 chicken, 27 turkey, 24 duck, and 24 game bird) and 5 Salmonella isolates (3 chicken, 1 turkey, and 1 duck) were recovered. One hundred and sixty-seven chicken, 5 turkey, 14 duck, and 15 game bird E. coli isolates were pan-susceptible. For E. coli, a moderate to high proportion of isolates were resistant to tetracycline (43% chicken, 81% turkey, 42% duck, and 38% game bird isolates), streptomycin (29% chicken, 37% turkey, and 33% game bird isolates), sulfonamides (17% chicken, 37% turkey, and 21% duck isolates), and ampicillin (16% chicken and 41% turkey isolates). Multidrug resistance was found in 37% of turkey, 20% of chicken, 13% of duck, and 8% of game bird E. coli isolates. Salmonella isolates were most frequently resistant to streptomycin, tetracycline, and sulfonamides. Resistance to cephalosporins, carbapenems, macrolides, and quinolones was infrequent in both E. coli and Salmonella isolates. Cluster and correlation analyses identified streptomycin-tetracycline-sulfisoxazole-trimethoprim-sulfamethoxazole as the most common resistance pattern in chicken E. coli isolates. Turkey E. coli isolates compared to all the other poultry species had higher odds of resistance to tetracycline and ampicillin, and a higher multidrug resistance rate. Conclusions Escherichia coli isolates were frequently resistant to antimicrobials commonly used to treat poultry bacterial infections, which highlights the necessity of judicious antimicrobial use to limit the emergence of multidrug resistant bacteria.

scholarly journals Role for Tandem Duplication and Lon Protease in AcrAB-TolC- Dependent Multiple Antibiotic Resistance (Mar) in an Escherichia coli Mutant without Mutations in marRAB or acrRAB

2006 ◽  
Vol 188 (12) ◽  
pp. 4413-4423 ◽  
Author(s):  
Hervé Nicoloff ◽  
Vincent Perreten ◽  
Laura M. McMurry ◽  
Stuart B. Levy
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Multidrug Resistance ◽  
Gene Duplication ◽  
Tandem Duplication ◽  
Lon Protease ◽  
Spontaneous Mutant ◽  
Multiple Antibiotic Resistance ◽  
E Coli ◽  
Coli Mutant

ABSTRACT A spontaneous mutant (M113) of Escherichia coli AG100 with an unstable multiple antibiotic resistance (Mar) phenotype was isolated in the presence of tetracycline. Two mutations were found: an insertion in the promoter of lon (lon3::IS186) that occurred first and a subsequent large tandem duplication, dupIS186, bearing the genes acrAB and extending from the lon3::IS186 to another IS186 present 149 kb away from lon. The decreased amount of Lon protease increased the amount of MarA by stabilization of the basal quantities of MarA produced, which in turn increased the amount of multidrug effux pump AcrAB-TolC. However, in a mutant carrying only a lon mutation, the overproduced pump mediated little, if any, increased multidrug resistance, indicating that the Lon protease was required for the function of the pump. This requirement was only partial since resistance was mediated when amounts of AcrAB in a lon mutant were further increased by a second mutation. In M113, amplification of acrAB on the duplication led to increased amounts of AcrAB and multidrug resistance. Spontaneous gene duplication represents a new mechanism for mediating multidrug resistance in E. coli through AcrAB-TolC.

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