scholarly journals Sequential Combined Effect of Phages and Antibiotics on the Inactivation of Escherichia coli

2018 ◽  
Vol 6 (4) ◽  
pp. 125 ◽  
Author(s):  
Ana Lopes ◽  
Carla Pereira ◽  
Adelaide Almeida
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Combined Treatment ◽  
Rapid Evolution ◽  
Generation Cephalosporin ◽  
Resistant Bacteria ◽  
Antibiotic Concentration ◽  
E Coli ◽  
Cephalosporin Resistance ◽  
Community Environments

The emergence of antibiotic resistance in bacteria is a global concern. The use of bacteriophages (or phages) alone or combined with antibiotics is consolidating itself as an alternative approach to inactivate antibiotic-resistant bacteria. However, phage-resistant mutants have been considered as a major threat when phage treatment is employed. Escherichia coli is one of the main responsible pathogens for moderate and serious infections in hospital and community environments, being involved in the rapid evolution of fluoroquinolones and third-generation cephalosporin resistance. The aim of this study was to evaluate the effect of combined treatments of phages and antibiotics in the inactivation of E. coli. For this, ciprofloxacin at lethal and sublethal concentrations was added at different times (0, 6, 12 and 18 h) and was tested in combination with the phage ELY-1 to inactivate E. coli. The efficacy of the combined treatment varied with the antibiotic concentration and with the time of antibiotic addition. The combined treatment prevented bacterial regrowth when the antibiotic was used at minimum inhibitory concentration (MIC) and added after 6 h of phage addition, causing less bacterial resistance than phage and antibiotic applied alone (4.0 × 10-7 for the combined treatment, 3.9 × 10-6 and 3.4 × 10-5 for the antibiotics and the phages alone, respectively). Combined treatment with phage and antibiotic can be effective in reducing the bacterial density and it can also prevent the emergence of resistant variants. However, the antibiotic concentration and the time of antibiotic application are essential factors that need to be considered in the combined treatment.

scholarly journals Occurrence of Antimicrobial-Resistant Escherichia coli and Salmonella enterica in the Beef Cattle Production and Processing Continuum

2014 ◽  
Vol 81 (2) ◽  
pp. 713-725 ◽  
Author(s):  
John W. Schmidt ◽  
Getahun E. Agga ◽  
Joseph M. Bosilevac ◽  
Dayna M. Brichta-Harhay ◽  
Steven D. Shackelford ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Salmonella Enterica ◽  
Generation Cephalosporin ◽  
Resistant Bacteria ◽  
Processing Plant ◽  
Cattle Production ◽  
Content Type ◽  
E Coli ◽  
Beef Processing ◽  
Tract Infections

ABSTRACTSpecific concerns have been raised that third-generation cephalosporin-resistant (3GCr)Escherichia coli, trimethoprim-sulfamethoxazole-resistant (COTr)E. coli, 3GCrSalmonella enterica, and nalidixic acid-resistant (NALr)S. entericamay be present in cattle production environments, persist through beef processing, and contaminate final products. The prevalences and concentrations of these organisms were determined in feces and hides (at feedlot and processing plant), pre-evisceration carcasses, and final carcasses from three lots of fed cattle (n= 184). The prevalences and concentrations were further determined for strip loins from 103 of the carcasses. 3GCrSalmonellawas detected on 7.6% of hides during processing and was not detected on the final carcasses or strip loins. NALrS. entericawas detected on only one hide. 3GCrE. coliand COTrE. coliwere detected on 100.0% of hides during processing. Concentrations of 3GCrE. coliand COTrE. colion hides were correlated with pre-evisceration carcass contamination. 3GCrE. coliand COTrE. coliwere each detected on only 0.5% of final carcasses and were not detected on strip loins. Five hundred and 42 isolates were screened for extraintestinal pathogenicE. coli(ExPEC) virulence-associated markers. Only two COTrE. coliisolates from hides were ExPEC, indicating that fed cattle products are not a significant source of ExPEC causing human urinary tract infections. The very low prevalences of these organisms on final carcasses and their absence on strip loins demonstrate that current sanitary dressing procedures and processing interventions are effective against antimicrobial-resistant bacteria.

scholarly journals Determining the Rate of Development of Antibiotic Resistance to Streptomycin and Doxycycline in Escherichia coli

2019 ◽  
pp. 2-7
Author(s):  
Dominique Tertigas ◽  
Gemma Barber
Keyword(s):  
Escherichia Coli ◽  
Antibiotic Resistance ◽  
Combination Treatment ◽  
Bacterial Resistance ◽  
Cross Resistance ◽  
Resistant Bacteria ◽  
Small Scale ◽  
Rate Of Development ◽  
E Coli ◽  
Successive Generations

Antibiotic resistance is a pressing issue in the medical field today. It is important to understand the development of bacterial resistance to implement effective preventative measures against antibiotic resistant bacteria. This study investigated the rate at which Escherichia coli (E. coli), a common pathogen, developed resistance to streptomycin and doxycycline, as Oz et al. (2014) showed differing levels of resistance in E. coli to these two antibiotics. The development of antibiotic resistance was measured by adding E. coli to 96-well plates in the presence of increasing doses of doxycycline, streptomycin, or a combination treatment. Successive generations were added to the same treatments to see whether they would grow at higher concentrations of antibiotic. The change in minimum inhibitory concentration for streptomycin and doxycycline was determined as the bacteria became increasingly resistant to each antibiotic. The fastest rate of antibiotic resistance was observed for streptomycin, with doxycycline resistance exhibiting a slower rate of development. The rate of resistance development for the combination treatment was the slowest, potentially due to small differences in target domains. Some cross-resistance was also observed. This study provides a small-scale methodological basis and preliminary insight on antibiotic resistance trends for two antibiotic classes and a combination treatment.

Intrathecal Administration of Amikacin for Treatment of Meningitis Secondary to Cephalosporin-Resistant Escherichia Coli

1993 ◽  
Vol 27 (7-8) ◽  
pp. 870-873 ◽  
Author(s):  
Sandra L. Preston ◽  
Laurie L. Briceland
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Generation Cephalosporin ◽  
Intrathecal Administration ◽  
Neurosurgical Procedures ◽  
Third Generation ◽  
E Coli ◽  
Efficacious Treatment ◽  
Clonic Seizures ◽  
Third Generation Cephalosporins

OBJECTIVE: To report a case of gram-negative bacillary meningitis (GNBM) secondary to cephalosporin-resistant Escherichia coli that was treated with intrathecal and intravenous amikacin and intravenous imipenem/cilastatin (I/C). CASE SUMMARY: A patient who had undergone two recent neurosurgical procedures developed GNBM and bacteremia. He was treated empirically with ceftazidime. Both bloodstream and cerebrospinal fluid isolates were identified as E. coli, resistant to third-generation cephalosporins, penicillins, tobramycin, and gentamicin. The patient was subsequently treated with intravenous and intrathecal amikacin plus intravenous I/C He experienced subjective and objective improvement on days 2–4 of antimicrobial therapy; two generalized tonic-clonic seizures occurred on days 7 and 12. Intrathecal amikacin was discontinued after 6 days, and intravenous amikacin and I/C were discontinued after 23 and 27 days, respectively. The patient's mental status did not completely return to premeningitis baseline. DISCUSSION: Third-generation cephalosporins are the treatment of choice for GNBM. In the case reported herein, bacterial resistance to these agents prompted the use of a therapy that has not been well studied and is also considered to be less safe and perhaps less efficacious. Treatment of GNBM with an intrathecally administered aminoglycoside or with intravenous I/C plus an aminoglycoside is reviewed. CONCLUSIONS: Patients with GNBM secondary to third-generation cephalosporin-resistant organisms may require therapies that may be less effective and more toxic. Further study of alternative agents is warranted.

scholarly journals Role of Ceftiofur in Selection and Dissemination of blaCMY-2-Mediated Cephalosporin Resistance in Salmonella enterica and Commensal Escherichia coli Isolates from Cattle

2009 ◽  
Vol 75 (11) ◽  
pp. 3648-3655 ◽  
Author(s):  
Joshua B. Daniels ◽  
Douglas R. Call ◽  
Dale Hancock ◽  
William M. Sischo ◽  
Katherine Baker ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
The United States ◽  
Generation Cephalosporin ◽  
Plasmid Transfer ◽  
Third Generation ◽  
Antimicrobial Drugs ◽  
E Coli ◽  
History Of ◽  
Cephalosporin Resistance

ABSTRACT Third-generation cephalosporin resistance of Salmonella and commensal Escherichia coli isolates from cattle in the United States is predominantly conferred by the cephamycinase CMY-2, which inactivates β-lactam antimicrobial drugs used to treat a wide variety of infections, including pediatric salmonellosis. The emergence and dissemination of bla CMY-2 --bearing plasmids followed and may in part be the result of selection pressure imposed by the widespread utilization of ceftiofur, a third-generation veterinary cephalosporin. This study assessed the potential effects of ceftiofur on bla CMY-2 transfer and dissemination by (i) an in vivo experimental study in which calves were inoculated with competent bla CMY-2-bearing plasmid donors and susceptible recipients and then subjected to ceftiofur selection and (ii) an observational study to determine whether ceftiofur use in dairy herds is associated with the occurrence and frequency of cephalosporin resistance in Salmonella and commensal E. coli. The first study revealed bla CMY-2 plasmid transfer in both ceftiofur-treated and untreated calves but detected no enhancement of plasmid transfer associated with ceftiofur treatment. The second study detected no association (P = 0.22) between ceftiofur use and either the occurrence of ceftiofur-resistant salmonellosis or the frequency of cephalosporin resistance in commensal E. coli. However, herds with a history of salmonellosis (including both ceftiofur-resistant and ceftiofur-susceptible Salmonella isolates) used more ceftiofur than herds with no history of salmonellosis (P = 0.03) These findings fail to support a major role for ceftiofur use in the maintenance and dissemination of bla CMY-2-bearing plasmid mediated cephalosporin resistance in commensal E. coli and in pathogenic Salmonella in these dairy cattle populations.

scholarly journals OmpF Downregulation Mediated by Sigma E or OmpR Activation Confers Cefalexin Resistance in Escherichia coli in the Absence of Acquired β-Lactamases.

2021 ◽  
Author(s):  
Maryam Alzayn ◽  
Punyawee Dulyayangkul ◽  
Naphat Satapoomin ◽  
Kate J Heesom ◽  
Matthew B Avison
Keyword(s):  
Escherichia Coli ◽  
Generation Cephalosporin ◽  
Loss Of Function ◽  
E Coli ◽  
Large Numbers ◽  
Regulatory Mutations ◽  
Cephalosporin Resistance ◽  
Human Infections ◽  
Sigma E ◽  
Group 1

Cefalexin is a widely used 1st generation cephalosporin, and resistance in Escherichia coli is caused by Extended-Spectrum (e.g. CTX-M) and AmpC β-lactamase production and therefore frequently coincides with 3rd generation cephalosporin resistance. However, we have recently identified large numbers of E. coli isolates from human infections, and from cattle, where cefalexin resistance is not β-lactamase mediated. Here we show, by studying laboratory selected mutants, clinical isolates, and isolates from cattle, that OmpF porin disruption or downregulation is a major cause of cefalexin resistance in E. coli. Importantly, we identify multiple regulatory mutations that cause OmpF downregulation. In addition to mutation of ompR, already known to downregulate OmpF and OmpC porin production, we find that rseA mutation, which strongly activates the Sigma E regulon, greatly increasing DegP production, which degrades OmpF, OmpC and OmpA porins. Furthermore, we reveal that mutations affecting lipopolysaccharide structure, exemplified by the loss of GmhB, essential for lipopolysaccharide heptosylation, also modestly activate DegP production, resulting in OmpF degradation. Remarkably, given the critical importance attached to such systems for normal E. coli physiology, we find evidence for DegP-mediated OmpF downregulation, gmhB and rseA loss of function mutation in E. coli isolates derived from human infections. Finally, we show that these regulatory mutations enhance the ability of group 1 CTX-M β-lactamase to confer reduced carbapenem susceptibility, particularly those mutations that cause OmpC in addition to OmpF downregulation.

scholarly journals Potential Inhibitory Effect of Apis mellifera’s Venom and of Its Two Main Components—Melittin and PLA2—on Escherichia coli F1F0-ATPase

Antibiotics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 824
Author(s):  
Hala Nehme ◽  
Helena Ayde ◽  
Dany El Obeid ◽  
Jean Marc Sabatier ◽  
Ziad Fajloun
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Inhibitory Effect ◽  
Resistant Bacteria ◽  
Bacterial Strains ◽  
Crude Venom ◽  
E Coli ◽  
F1f0 Atpase ◽  
Main Components ◽  
Dose Dependent

Bacterial resistance has become a worrying problem for human health, especially since certain bacterial strains of Escherichia coli (E. coli) can cause very serious infections. Thus, the search for novel natural inhibitors with new bacterial targets would be crucial to overcome resistance to antibiotics. Here, we evaluate the inhibitory effects of Apis mellifera bee venom (BV-Am) and of its two main components -melittin and phospholipase A2 (PLA2)- on E. coli F1F0-ATPase enzyme, a crucial molecular target for the survival of these bacteria. Thus, we optimized a spectrophotometric method to evaluate the enzymatic activity by quantifying the released phosphate from ATP hydrolysis catalyzed by E. coli F1F0-ATPase. The protocol developed for inhibition assays of this enzyme was validated by two reference inhibitors, thymoquinone (IC50 = 57.5 μM) and quercetin (IC50 = 30 μM). Results showed that BV-Am has a dose-dependent inhibitory effect on E. coli F1F0-ATPase with 50% inhibition at 18.43 ± 0.92 μg/mL. Melittin inhibits this enzyme with IC50 = 9.03 ± 0.27 µM, emphasizing a more inhibitory effect than the two previous reference inhibitors adopted. Likewise, PLA2 inhibits E. coli F1F0-ATPase with a dose-dependent effect (50% inhibition at 2.11 ± 0.11 μg/mL) and its combination with melittin enhanced the inhibition extent of this enzyme. Crude venom and mainly melittin and PLA2, inhibit E. coli F1F0-ATPase and could be considered as important candidates for combating resistant bacteria.

scholarly journals Profile of Antibiotic Resistant Bacteria Isolated from Slaughterhouse Effluents of Etoudi-Yaounde and Its Receiving Waterbody

2021 ◽  
Vol 11 (4) ◽  
pp. 40-47
Author(s):  
Merveille Tamema Masse ◽  
Romuald Jacques Samba Aloys ◽  
Brunelle Tchakounte Betbui
Keyword(s):  
Escherichia Coli ◽  
Bacterial Resistance ◽  
Generation Cephalosporin ◽  
Resistant Bacteria ◽  
Antibiotic Resistant Bacteria ◽  
Salmonella Spp ◽  
Antibiotic Resistant ◽  
Bacterial Drug Resistance ◽  
Shigella Spp ◽  
Wastewater Samples

The Profile of antibiotic resistant bacteria isolated from slaughterhouse effluents of Etoudi-Yaounde, and its receiving waterbody (River Ako’o) were investigated. Wastewater samples were collected from abattoir outlet and along the river (pond, mid river and out-river). Resistance to amoxicillin, tetracycline, ciprofloxacin, sulfamethoxazole / trimethoprim, cefixime and kanamycin were determined. Resistance to amoxicillin was the highest (96.3 %), followed by sulfamethoxazole / trimethoprim (85.1%), kanamycin (81.5 %), cefixime (81.3 %), tetracycline (80.9 %) and ciprofloxacin (73.6 %). Bacterial resistance was higher in October, compared to March and December. Higher resistance ratios were observed downstream at out-river (77.9 %). Enterobacteria constituted 80% of the isolates. Escherichia coli, Salmonella spp., Klebsiella spp., Shigella spp., Staphylococcus spp. and Streptococcus spp. were the identified drug resistant bacteria, Escherichia coli was more prevalent (30.7%). All isolates were multi-resistant antibiotic resistant bacteria and some presented resistance to third generation cephalosporin. Wastewater from Etoudi-abattoir is a serious vector of the spread of bacterial drug resistance, thus, strategies towards hygiene and sanitation of the slaughterhouse and its effluents should be implemented. Key words: Antibiotic resistance, slaughterhouse wastewater, public health.

scholarly journals Increasing incidence and antimicrobial resistance in Escherichia coli bloodstream infections: a multinational population-based cohort study

2021 ◽  
Vol 10 (1) ◽  
Author(s):  
Melissa C. MacKinnon ◽  
Scott A. McEwen ◽  
David L. Pearl ◽  
Outi Lyytikäinen ◽  
Gunnar Jacobsson ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Incidence Rate ◽  
Bloodstream Infections ◽  
Generation Cephalosporin ◽  
Population Based ◽  
Incidence Rates ◽  
Third Generation ◽  
Common Cause ◽  
E Coli ◽  
Cephalosporin Resistance

Abstract Background Escherichia coli is an important pathogen in humans and is the most common cause of bacterial bloodstream infections (BSIs). The objectives of our study were to determine factors associated with E. coli BSI incidence rate and third-generation cephalosporin resistance in a multinational population-based cohort. Methods We included all incident E. coli BSIs (2014–2018) from national (Finland) and regional (Australia [Canberra], Sweden [Skaraborg], and Canada [Calgary, Sherbrooke, and western interior]) surveillance. Incidence rates were directly age and sex standardized to the European Union 28-country 2018 population. Multivariable negative binomial and logistic regression models estimated factors significantly associated with E. coli BSI incidence rate and third-generation cephalosporin resistance, respectively. The explanatory variables considered for inclusion in both models were year (2014–2018), region (six areas), age (< 70-years-old and ≥ 70-years-old), and sex (female and male). Results We identified 31,889 E. coli BSIs from 40.7 million person-years of surveillance. Overall and third-generation cephalosporin-resistant standardized rates were 87.1 and 6.6 cases/100,000 person-years, respectively, and increased 14.0% and 40.1% over the five-year study. Overall, 7.8% (2483/31889) of E. coli BSIs were third-generation cephalosporin-resistant. Calgary, Canberra, Sherbrooke, and western interior had significantly lower E. coli BSI rates compared to Finland. The significant association between age and E. coli BSI rate varied with sex. Calgary, Canberra, and western interior had significantly greater odds of third-generation cephalosporin-resistant E. coli BSIs compared to Finland. Compared to 2014, the odds of third-generation cephalosporin-resistant E. coli BSIs were significantly increased in 2016, 2017, and 2018. The significant association between age and the odds of having a third-generation cephalosporin-resistant E. coli BSI varied with sex. Conclusions Increases in overall and third-generation cephalosporin-resistant standardized E. coli BSI rates were clinically important. Overall, E. coli BSI incidence rates were 40–104% greater than previous investigations from the same study areas. Region, sex, and age are important variables when analyzing E. coli BSI rates and third-generation cephalosporin resistance in E. coli BSIs. Considering E. coli is the most common cause of BSIs, this increasing burden and evolving third-generation cephalosporin resistance will have an important impact on human health, especially in aging populations.

scholarly journals Social and Environmental Determinants of Community-Acquired Antimicrobial-Resistant Escherichia coli in Children Living in Semirural Communities of Quito, Ecuador

2021 ◽  
Author(s):  
Kathleen M. Kurowski ◽  
Rachel Marusinec ◽  
Heather K. Amato ◽  
Carlos Saraiva-Garcia ◽  
Fernanda Loayza ◽  
...  
Keyword(s):  
Risk Factors ◽  
Escherichia Coli ◽  
Generation Cephalosporin ◽  
Multidrug Resistant ◽  
Resistant Bacteria ◽  
Drug Resistant ◽  
Extended Spectrum Beta Lactamase ◽  
E Coli ◽  
Drug Resistant Bacteria ◽  
Household Crowding

Extended-spectrum beta-lactamase-producing Enterobacteriaceae (ESBL), a family of bacteria that includes Escherichia coli, have emerged as a global health threat. This study examined risks associated with carriage of third-generation cephalosporin-resistant (3GC-R) E. coli, including ESBL-producing, multidrug-resistant, and extensively drug-resistant (XDR) strains in children living in semirural parishes of Quito, Ecuador. We conducted a longitudinal study with two cycles of sampling (N = 374, N = 366) that included an analysis of child fecal samples and survey questions relating to water, sanitation, and hygiene, socioeconomic status, household crowding, and animal ownership. We used multivariate regression models to assess risk factors associated with a child being colonized. Across the two cycles, 18.4% (n = 516) of the 3GC-R isolates were ESBL-producing E. coli, and 40.3% (n = 516) were XDR E. coli. Children living in households that owned between 11 and 20 backyard animals had an increased odds of being colonized with XDR E. coli (odds ratio [OR] = 1.94, 95% confidence interval [CI]: 1.05–3.60) compared with those with no animals. Households that reported smelling odors from commercial poultry had increased odds of having a child positive for XDR E. coli (OR = 1.72, 95% CI: 1.11–2.66). Our results suggest that colonization of children with antimicrobial-resistant E. coli is influenced by exposure to backyard and commercial livestock and poultry. Future studies should consider community-level risk factors because child exposures to drug-resistant bacteria are likely influenced by neighborhood and regional risk factors.

scholarly journals OmpF Downregulation Mediated by Sigma E or OmpR Activation Confers Cefalexin Resistance in Escherichia coli in the Absence of Acquired β-Lactamases.

2021 ◽  
Author(s):  
Maryam Alzayn ◽  
Punyawee Dulyayangkul ◽  
Naphat Satapoomin ◽  
Kate J. Heesom ◽  
Matthew B. Avison
Keyword(s):  
Escherichia Coli ◽  
Generation Cephalosporin ◽  
Loss Of Function ◽  
E Coli ◽  
Large Numbers ◽  
Regulatory Mutations ◽  
Cephalosporin Resistance ◽  
Human Infections ◽  
Sigma E ◽  
Group 1

Cefalexin is a widely used 1 st generation cephalosporin, and resistance in Escherichia coli is caused by Extended-Spectrum (e.g., CTX-M) and AmpC β-lactamase production and therefore frequently coincides with 3 rd generation cephalosporin resistance. However, we have recently identified large numbers of E. coli isolates from human infections, and from cattle, where cefalexin resistance is not β-lactamase mediated. Here we show, by studying laboratory selected mutants, clinical isolates, and isolates from cattle, that OmpF porin disruption or downregulation is a major cause of cefalexin resistance in E. coli . Importantly, we identify multiple regulatory mutations that cause OmpF downregulation. In addition to mutation of ompR , already known to downregulate OmpF and OmpC porin production, we find that rseA mutation, which strongly activates the Sigma E regulon, greatly increasing DegP production, which degrades OmpF, OmpC and OmpA. Furthermore, we reveal that mutations affecting lipopolysaccharide structure, exemplified by the loss of GmhB, essential for lipopolysaccharide heptosylation, also modestly activate DegP production, resulting in OmpF degradation. Remarkably, given the critical importance attached to such systems for normal E. coli physiology, we find evidence for DegP-mediated OmpF downregulation, gmhB and rseA loss of function mutation in E. coli isolates derived from human infections. Finally, we show that these regulatory mutations enhance the ability of group 1 CTX-M β-lactamase to confer reduced carbapenem susceptibility, particularly those mutations that cause OmpC in addition to OmpF downregulation.

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