Acquisition of Antibiotic Resistance Plasmids by Enterohemorrhagic Escherichia coli O157:H7 within Rumen Fluid

2002 ◽  
Vol 65 (6) ◽  
pp. 1038-1040 ◽  
Author(s):  
SHAIKH MIZAN ◽  
MARGIE D. LEE ◽  
BARRY G. HARMON ◽  
SUZANA TKALCIC ◽  
JOHN J. MAURER

The emergence of antibiotic resistance among important foodborne pathogens like Escherichia coli O157:H7 has become an important issue with regard to food safety. In contrast to the case for Salmonella, antibiotic resistance has been slow in its development in E. coli O157:H7 despite the presence of mobile antibiotic resistance genes in other E. coli organisms that inhabit the same animal host. We set out to determine if rumen fluid influences the transfer of plasmid-mediated, antibiotic resistance to E. coli O157:H7. A commensal E. coli strain from a dairy cow was transformed with conjugative R plasmids and served as the donor in matings with naladixic acid–resistant E. coli O157:H7. R plasmids were transferred from the donor E. coli strain to E. coli O157:H7 in both Luria-Bertani (LB) broth and rumen fluid. R plasmids were transferred at a higher frequency to E. coli O157:H7 during 6 h of incubation in rumen fluid at rates comparable to those in LB broth, indicating that conditions in rumen fluid favor the transfer of the plasmids to E. coli O157. This finding suggests that the cow's rumen is a favorable environment for the genetic exchange of plasmids between microflora and resident E. coli O157:H7 in the bovine host.

2009 ◽  
Vol 55 (11) ◽  
pp. 1229-1239 ◽  
Author(s):  
Cynthia L. Handford ◽  
Charma T. Stang ◽  
Tracy L. Raivio ◽  
Jonathan J. Dennis

Two uncharacterized small cryptic plasmids (SCPs) were isolated from enteropathogenic Escherichia coli strain E2348/69. Genomic DNA sequence analysis of both SCPs indicated that the smaller plasmid, p5217, encoded several mobilization genes, whereas the larger plasmid, p6148, encoded several putative antibiotic resistance determinants. Complementation analysis showed that p6148 encodes functional streptomycin resistance genes but, owing to the presence of several frameshift mutations, a nonfunctional sulfonamide resistance determinant. A plasmid similar to p6148 has previously been shown to confer a slight growth advantage on E. coli. However, we were unable to observe any significant growth advantage in different E. coli strains transformed with p6148. The p6148 DNA sequence is homologous in sequence and arrangement to DNA from other plasmid families, including large conjugative plasmids and SXT integrative and conjugative elements. This study suggests that gene clusters of the sul2–strAB antibiotic resistance genes are widespread and highly transferable, owing to their presence in a wide variety of mobile genetic elements.


2015 ◽  
Vol 3 (5) ◽  
Author(s):  
Daniela Jones-Dias ◽  
Vera Manageiro ◽  
Daniel Ataíde Sampaio ◽  
Luís Vieira ◽  
Manuela Caniça

Escherichia coli is a commensal bacterium that is frequently associated with multidrug-resistant zoonotic and foodborne infections. Here, we report the 5.6-Mbp draft genome sequence of an E. coli recovered from poultry, which encodes multiple acquired antibiotic resistance determinants, virulence factors, pathogenicity determinants, and mobile genetic elements.


2004 ◽  
Vol 67 (3) ◽  
pp. 486-492 ◽  
Author(s):  
GERRY P. SCHAMBERGER ◽  
FRANCISCO DIEZ-GONZALEZ

A previously identified set of anti– Escherichia coli O157:H7 colicinogenic E. coli were characterized to assess the suitability of these isolates as a preharvest food safety intervention in cattle. This collection of 23 E. coli strains were screened for virulence factors, antibiotic resistance, type of colicin(s) present, and their ability to inhibit other pathogenic E. coli. With the use of PCR, pathogen genes were detected in six of the 23 colicinogenic E. coli. When the nonpathogenic strains were assessed for antibiotic resistance, four strains showed resistance to at least one antibiotic. The remaining set of 14 strains were evaluated for the presence of previously identified colicins. Seven colicins (B, E1, E2/E7, E7, Ia/Ib, K, and M) were detected. One half of the strains possessed multiple types of colicins. The most commonly detected colicins were B, E2/E7, and M, which were found in six strains each. DNA sequencing was also performed in order to classify the E2/E7 colicins separately from E7 colicins. The 14 colicinogenic E. coli also were evaluated for their ability to inhibit 10 different non-O157 pathogenic E. coli. Six of the colicinogenic E. coli were capable of inhibiting all 10 pathogens, and the remaining eight strains could each inhibit between six to eight of the pathogenic E. coli. This strain collection has great potential for inhibiting E. coli O157:H7 in cattle.


2004 ◽  
Vol 48 (10) ◽  
pp. 3996-4001 ◽  
Author(s):  
Yolanda Sáenz ◽  
Laura Briñas ◽  
Elena Domínguez ◽  
Joaquim Ruiz ◽  
Myriam Zarazaga ◽  
...  

ABSTRACT Seventeen multiple-antibiotic-resistant nonpathogenic Escherichia coli strains of human, animal, and food origins showed a wide variety of antibiotic resistance genes, many of them carried by class 1 and class 2 integrons. Amino acid changes in MarR and mutations in marO were identified for 15 and 14 E. coli strains, respectively.


1997 ◽  
Vol 60 (8) ◽  
pp. 891-897 ◽  
Author(s):  
L. M. HUDSON ◽  
J. CHEN ◽  
A. R. HILL ◽  
M. W. GRIFFITHS

Outbreaks of enterohemorrhagic Escherichia coli O157:H7 have been commonly associated with products derived from ground beef, but recently the organism has been implicated as the causative agent in outbreaks involving yogurt and cheese. This finding has raised concern about the potential for its growth and survival in fermented dairy products. A bioluminescent strain of E. coli O157:H7 was used to determine postprocessing survival in yogurt with live cultures at pH 4.17, 4.39, and 4.47 stored at 4 and 10°C. In addition, survival of E. coli O157:H7 was monitored during the manufacture of Cottage, Colby, Romano, and Feta cheeses. Results indicated survival for 8 and 5 days at 4 and 10°C respectively in yogurt at pH 4.17, 17 and 15 days at 4 and 10°C respectively in yogurt at pH 4.39, and 17days at both 4 and 10°C in yogurt at pH 4.47. E. coli O157:H7 did not survive cooking procedures at 56°C in Cottage cheese. However, the pathogen survived for 27, 30, and 27 days in Colby, Romano, and Feta cheeses respectively. A high correlation of r2 > 0.89 was obtained between counts of bioluminescenct colonies and standard plate count for all yogurt and cheese varieties, indicating that bioluminescence was a sensitive and rapid indicator of cellular viability for E. coli O157:H7. Survival of the pathogen, as indicated by this method, is possible in highly acidic environments even at refrigeration temperatures. This poses a potential hazard should postprocessing contamination occur.


2019 ◽  
Vol 12 (7) ◽  
pp. 984-993 ◽  
Author(s):  
Md. Abdus Sobur ◽  
Abdullah Al Momen Sabuj ◽  
Ripon Sarker ◽  
A. M. M. Taufiqur Rahman ◽  
S. M. Lutful Kabir ◽  
...  

Aim: The present study was carried out to determine load of total bacteria, Escherichia coli and Salmonella spp. in dairy farm and its environmental components. In addition, the antibiogram profile of the isolated bacteria having public health impact was also determined along with identification of virulence and resistance genes by polymerase chain reaction (PCR) under a one-health approach. Materials and Methods: A total of 240 samples of six types (cow dung - 15, milk - 10, milkers' hand wash - 10, soil - 10 water - 5, and vegetables - 10) were collected from four dairy farms. For enumeration, the samples were cultured onto plate count agar, eosin methylene blue, and xylose-lysine deoxycholate agar and the isolation and identification of the E. coli and Salmonella spp. were performed based on morphology, cultural, staining, and biochemical properties followed by PCR. The pathogenic strains of E. coli stx1, stx2, and rfbO157 were also identified through PCR. The isolates were subjected to antimicrobial susceptibility test against 12 commonly used antibiotics by disk diffusion method. Detection of antibiotic resistance genes ereA, tetA, tetB, and SHV were performed by PCR. Results: The mean total bacterial count, E. coli and Salmonella spp. count in the samples ranged from 4.54±0.05 to 8.65±0.06, 3.62±0.07 to 7.04±0.48, and 2.52±0.08 to 5.87±0.05 log colony-forming unit/g or ml, respectively. Out of 240 samples, 180 (75%) isolates of E. coli and 136 (56.67%) isolates of Salmonella spp. were recovered through cultural and molecular tests. Among the 180 E. coli isolates, 47 (26.11%) were found positive for the presence of all the three virulent genes, of which stx1 was the most prevalent (13.33%). Only three isolates were identified as enterohemorrhagic E. coli. Antibiotic sensitivity test revealed that both E. coli and Salmonella spp. were found highly resistant to azithromycin, tetracycline, erythromycin, oxytetracycline, and ertapenem and susceptible to gentamycin, ciprofloxacin, and imipenem. Among the four antibiotic resistance genes, the most observable was tetA (80.51-84.74%) in E. coli and Salmonella spp. and SHV genes were the lowest one (22.06-25%). Conclusion: Dairy farm and their environmental components carry antibiotic-resistant pathogenic E. coli and Salmonella spp. that are potential threat for human health which requires a one-health approach to combat the threat.


2001 ◽  
Vol 64 (6) ◽  
pp. 783-787 ◽  
Author(s):  
CAROLYN M. MAYERHAUSER

Escherichia coli O157:H7 survival in acid foods such as unpasteurized apple cider and fermented sausage is well documented. Researchers have determined that E. coli O157:H7 can survive in refrigerated acid foods for weeks. The potential of acid foods to serve as a vector of E. coli O157:H7 foodborne illness prompted this study to determine the fate of this organism in retail mustard containing acetic acid when stored at room and refrigerated temperatures. Various retail brands of dijon, yellow, and deli style mustard, pH ranging from 3.17 to 3.63, were inoculated individually with three test strains of E. coli O157:H7. Samples were inoculated with approximately 1.0 × 106 CFU/g, incubated at room (25 ± 2.5°C) and refrigerated (5 ± 3°C) temperatures, and assayed for surviving test strains at predetermined time intervals. An aliquot was appropriately diluted and plated using sorbitol MacConkey agar (SMAC). When the test strain was not recoverable by direct plating, the sample was assayed by enrichment in modified tryptic soy broth and recovered using SMAC. Growth of E. coli O157:H7 test strains was inhibited in all retail mustard styles. E. coli O157:H7 was not detected in dijon style mustard beyond 3 h at room and 2 days at refrigerated temperatures. Survival in yellow and deli style mustard was not detected beyond 1 h. Overall, test strain survival was greater at refrigerated than room temperature. Retail mustard demonstrated the ability to eliminate effectively any chance contamination by this organism within hours to days, suggesting that these products are not a likely factor in E. coli O157:H7 foodborne illness.


2020 ◽  
Vol 7 ◽  
Author(s):  
John I. Alawneh ◽  
Ben Vezina ◽  
Hena R. Ramay ◽  
Hulayyil Al-Harbi ◽  
Ameh S. James ◽  
...  

Escherichia coli is frequently associated with mastitis in cattle. “Pathogenic” and “commensal” isolates appear to be genetically similar. With a few exceptions, no notable genotypic differences have been found between commensal and mastitis-associated E. coli. In this study, 24 E. coli strains were isolated from dairy cows with clinical mastitis in three geographic regions of Australia (North Queensland, South Queensland, and Victoria), sequenced, then genomically surveyed. There was no observed relationship between sequence type (ST) and region (p = 0.51). The most common Multi Locus Sequence Type was ST10 (38%), then ST4429 (13%). Pangenomic analysis revealed a soft-core genome of 3,463 genes, including genes associated with antibiotic resistance, chemotaxis, motility, adhesion, biofilm formation, and pili. A total of 36 different plasmids were identified and generally found to have local distributions (p = 0.02). Only 2 plasmids contained antibiotic resistance genes, a p1303_5-like plasmid encoding multidrug-resistance (trimethoprim, quaternary ammonium, beta-lactam, streptomycin, sulfonamide, and kanamycin) from two North Queensland isolates on the same farm, while three Victorian isolates from the same farm contained a pCFSAN004177P_01-like plasmid encoding tetracycline-resistance. This pattern is consistent with a local spread of antibiotic resistance through plasmids of bovine mastitis cases. Notably, co-occurrence of plasmids containing virulence factors/antibiotic resistance with putative mobilization was rare, though the multidrug resistant p1303_5-like plasmid was predicted to be conjugative and is of some concern. This survey has provided greater understanding of antibiotic resistance within E. coli-associated bovine mastitis which will allow greater prediction and improved decision making in disease management.


2003 ◽  
Vol 71 (3) ◽  
pp. 1505-1512 ◽  
Author(s):  
Stuart W. Naylor ◽  
J. Christopher Low ◽  
Thomas E. Besser ◽  
Arvind Mahajan ◽  
George J. Gunn ◽  
...  

ABSTRACT Escherichia coli O157:H7 causes bloody diarrhea and potentially fatal systemic sequelae in humans. Cattle are most frequently identified as the primary source of infection, and E. coli O157:H7 generally colonizes the gastrointestinal tracts of cattle without causing disease. In this study, persistence and tropism were assessed for four different E. coli O157:H7 strains. Experimentally infected calves shed the organism for at least 14 days prior to necropsy. For the majority of these animals, as well as for a naturally colonized animal obtained from a commercial beef farm, the highest numbers of E. coli O157:H7 were found in the feces, with negative or significantly lower levels detected in lumen contents taken from the gastrointestinal tract. Detailed examination demonstrated that in these individuals the majority of tissue-associated bacteria were adherent to mucosal epithelium within a defined region extending up to 5 cm proximally from the recto-anal junction. The tissue targeted by E. coli O157:H7 was characterized by a high density of lymphoid follicles. Microcolonies of the bacterium were readily detected on the epithelium of this region by immunofluorescence microscopy. As a consequence of this specific distribution, E. coli O157:H7 was present predominately on the surface of the fecal stool. In contrast, other E. coli serotypes were present at consistent levels throughout the large intestine and were equally distributed in the stool. This is a novel tropism that may enhance dissemination both between animals and from animals to humans. The accessibility of this site may facilitate simple intervention strategies.


1998 ◽  
Vol 61 (6) ◽  
pp. 662-667 ◽  
Author(s):  
GUODONG WANG ◽  
MICHAEL P. DOYLE

Several recent Escherichia coli O157:H7 outbreaks associated with both drinking and recreational water raise concerns about waterborne illness caused by this pathogen. The survival characteristics of a mixture of five nalidixic acid-resistant E. coli O157:H7 strains (103 CFU/ml) in filtered and autoclaved municipal water, in reservoir water, and in water from two recreational lakes were determined for a period of 91 days at 8, 15, or 25°C. Greatest survival was in filtered autoclaved municipal water and least in lake water. Regardless of the water source, survival was greatest at 8°C and least at 25°C. E. coli O157:H7 populations decreased by 1 to 2 log10 by 91 days at 8°C, whereas the pathogen was not detectable (≥3 log10 decrease) within 49 to 84 days at 25°C in three of the four water sources. SDS-PAGE of surface antigens of surviving cells revealed that there was no major alteration in lipopolysaccharide pattern, but outer membrane protein composition did change. These studies indicate that E. coli O157:H7 is a hardy pathogen that can survive for long periods of time in water, especially at cold temperatures. However, direct viable counts of E. coli O157:H7 determined by acridine orange staining remained essentially the same for 12 weeks at 25°C, whereas viable counts on tryptic soy agar plates decreased to undetectable levels within 12 weeks. Results suggest that E. coli O157:H7 can enter a viable but nonculturable (VBNC) state in water.


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