Advances in Animal and Veterinary Sciences

Download PDF Download ePUB



Research Article


Molecular Characterization and Antimicrobial Resistance Gene of E. coli and Salmonella Kentucky Isolated from Turkeys in Egypt


Ashraf A. Abd El-Tawab1, Amira Mohamed Rizk1*, Seham N. Homouda2, Emad E. El- Mougy3, Alaa M. Gouda4

1Bacteriology, Immunology and Mycology Department, Faculty of Veterinary Medicine, Benha University, Egypt; 2Food hygiene Deptartment, Animal Health Research Institute, Tanta Branch, Egypt; 3Faculty of Veterinary Medicine, Benha University, Egypt; 4Veterinary Medicine, El-Gharbia, Egypt.


Abstract | This study aimed to determine the extent of possibility of apparently healthy turkeys being reservoirs for the pathogenic strains of E. coli and Salmonella kentucky. A total 150 cloacal swab samples from apparently healthy turkeys from Gharbia governorate, Egypt were investigated bacteriologically and biochemically. The overall prevalence of E. coli and Salmonella Kentucky were 55 (36.67%) and 4 (2.7%) respectively. The Congo red binding assay results revealed 10 pathogenic E. coli isolates out of 55 (18.18%). The antibiotic sensitivity test revealed E-coli and S.kentucky isolates were 100% resistant to β-Lactames (ampicillin, amoxicillin/clavulanic, cefaclor and ceftazidime) while being 100% sensitive to Carbapenem (imipenem). E-coli and S.kentucky Isolates were 100% and 75% resistant to Phenicols (chloramphenicol), 60% and 75% resistant to Fluoroquinolone (ciprofloxacin), 50% and 50% resistant to Aminoglycoside (gentamicin) while being 10% and 25% resistant to Macrolides (azithromycin) respectively. Polymerase chain reaction (PCR) was applied on E. coli and Salmonella isolates to detect resistance gene (blaTEM, blaOXA, floR, aadB and qnrA). All isolates were revealed to express these multi-drug resistant genes by (100%), (0%), (100%), (100%) and (0%) respectively. Our results concluded that turkeys could be a reservoir for resistant E. coli and Salmonella spp., resulting in economic and public health problems which require the development of strategies to reduce and control the development and spread of antimicrobial resistance especially in apparent health turkey flocks.


Keywords | E. coli, Salmonella, Turkey, Antibiotic, Resistance genes


Received | November 16, 2019; Accepted | February 17, 2020; Published | June 25. 2020

*Correspondence | Amira Mohamed Rizk, Bacteriology, Immunology and Mycology Department, Faculty of Veterinary Medicine, Benha University, Egypt; Email:

Citation | El-Tawab AAA, Rizk AM, Homouda SN, El-Mougy EE, Gouda AM (2020). Molecular characterization and antimicrobial resistance gene of E. coli and Salmonella Kentucky isolated from Turkeys in Egypt. Adv. Anim. Vet. Sci. 8(7): 742-747.


ISSN (Online) | 2307-8316; ISSN (Print) | 2309-3331

Copyright © 2020 El-Tawab et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.




Poultry is the most consumed type of meat worldwide.The overuse of antibiotics as therapeutics and growth promoters without precise supervision and control leads to the development of several aspects of antimicrobial resistance (Nhung et al., 2016).


Turkeys convey antimicrobial resistance to human which can be risky in consumption of retail meat. Primary monitoring finding also indicates that poultry meats contain resistant bacteria (Aslam, 2012). The developed resistant pathogens associated with diseases and the rising antibiotic resistant gene gathering in commensal bacteria is alarming. Therefore, more research is needed for understanding the prevalence and dynamics of antimicrobial resistance bacteria in poultry flocks (Chinivasagam et al., 2010). The irregular use of antimicrobials leads to selection of multi-resistant strains of E. coli and salmonella in poultry and plays important role in the transmission of antibiotic-resistant bacteria along the food chain to humans (Moawad et al., 2017; CDC, 2011). Turkey was the second highest category for foodborne outbreaks caused by meat, poultry, or their products between 1998 and 2010 in the USA (CSPI, 2013). E. coli and S.enterica serovars kentucky are foodborne pathogens isolated from poultry and beef meat with the advent of antimicrobial resistance in Egypt (Moawed et al., 2017).


According to the National Antimicrobial Resistance Monitoring System (NARMS), E. coli and Salmonella exhibited resistance to more than 3 classes of antimicrobial among turkey. (NARMS, 2014). The use of a rapid molecular assay is considered as a useful tool for detection of antibiotic resistance in poultry production (El-adawy et al., 2012). Detection of resistance genes using PCR is highly specific and very ensitive method and less time consuming (Malkawi, 2003). This study aimed to elucidate the prevalence, serotyping, antimicrobial resistance and resistance-associated genes in E. coli and S. kentucky isolated from healthy turkey.




Ethical approval

All samples were taken according to standard sample collection procedure without putting any stress on the bird. The current study was approved by the Ethical Committee for Medical Research at the faculty of veterinary sciences, Benha University and Animal Care Guidelines of the General Organization for Veterinary Services, Egypt.


Sample collection

A total of 150 cloacal samples were collected from living apparently healthy turkeys (40 of each at 35 days old and 110 of each at 4 months old) using sterile swabs. The samples were collected from different turkey farms located in different geographic areas of Gharbia governorate, Egypt. These samples were being transferred without delay to the laboratory in an ice box under complete aseptic condition to the laboratory for bacteriological examination.


Isolation and identification of bacteria

The detection and identification of E. coli and S. kentucky according to (Qunin et al., 2002) and ISO 6579 (2002). Sampling was carried out using sterile cotton swabs dipping in sterile 0.8% saline solution. For isolation of E. coli, 1 ml added to 9 ml MacConkey broth (Oxoid) and incubated at 37°C for up to 48 hours, while for Salmonella detection, cloacal swabs pre-enriched in buffered peptone water (Oxoid) at 37 C for 18 hours. After overnight incubation, 0.1 mL of the incubated pre-enrichment was transferred to 10 mL of Rappaport-Vassilliadis enrichment broth (Oxoid) and incubated at 42°C ± 1°C for 24 hours. A loopful from Rappaport–Vassiliadis broth was streaked on xylose lysine deoxycholate (XLD) agar and Salmonella-Shigella agar (Oxoid) and from macConky broth on macConky agar plates. The pink (lactose fermenter) colonies were picked and cultured onto eosin methylene blue (EMB) agar (Oxoid, Manchester, UK). The inoculated plates were incubated aerobically at 37°C for 18–24h. Suspected colonies were stored onto semi-solid agar to be preserved at 4°C for further examination.


Vitro pathogenicity test of E. coli isolates.

The isolated E. coli were tested for the pathogenicity on Congo red (CR) dye binding assay described by (Berkhoff and Vinal, 1986). The Congo red medium (Sigma) was prepared by adding 0.03% of Congo red dye to the trypticase soya agar (TSA), the E. coli isolates were streaked onto the plates and plates were incubated at 37°C for 24-72 hours. Appearance of deep brick red coloured colonies after an incubation for 24, 48 and 72 hours indicated positive result, while pale or white colonies were considered as negative.



The obtained CR-positive E. coli isolates were serotyped using slide agglutination method using commercial antisera (SIFIN). Serological identification of Salmonella spp. based on somatic (O) and flagellar (H) antigens according to the Kauffmann–White typing scheme (Popoff et al., 2004). The serotyping was applied at the Serology Unit, Animal Health Research Institute, Dokki, Egypt.


Antimicrobials susceptibility testing

E. coli and Salmonella isolates were screened for their resistance to the following antibiotics (Oxoid): amoxicillin-clavulanic (AMC) 30μg, ampicillin 10µg (AMP), ceftzidime 30µg (CAZ), cefaclor 30µg (CEC), imipenem (IPM) 10µg, ciprofloxacin (CIP) 5 μg, gentamicin (CN) 10μg, chloramphenicol (C) 30µg and azithromycin (AZM) 15µg, according to (Koneman et al., 1997) and the degree of sensitivity was interpreted according (NCCLS, 2002, 2016).


Detection of resistant genes was determined by PCR

DNA was extracted from the isolated E. coli and Salmonella using QIAamp DNA mini kit. It was applied on 5 random isolates. PCR Master Mix and cycling conditions of the primers during PCR was prepared according to Emerald Amp GT PCR mastermix (Takara) kit. Oligonucleotide primers used in PCR have specific sequence and amplify a specific product (Table 1). DNA samples for uniplex PCR were amplified in a total of 25μl as follows: 12.5μl of Emerald Amp GT PCR mastermix, 1μl of each primer of 20 pmol concentrations, 4.5 μl of grade water and 6 μl of template DNA. The reaction was performed in a Biometra thermal cycler. Temperature and time conditions of the primers during PCR were applied. Aliquots of amplified PCR products were electrophoresed in 1.5 % agarose gel (ABgene) in 1x TBE buffer at room temperature. For gel analysis, 15 μl of PCR products were loaded in each gel slot.


Table 1: PCR primers used and amplicons size of antibiotic resistant genes.


Resistant genes Primer Sequence (5'-3') Amplicons size Reference



Frana et al., 2001




Colom et al., 2003






Robicsek et al., 2006




Doublet et al., 2003




A 100 bp DNA ladder (QIAGEN Inc, Valencia, CA, USA) was used to determine the fragment sizes. The gel was photographed by a gel documentation system and the data was analyzed through computer software.




Prevalence of E. coli and Salmonella in samples

Out of 150 cloacal swab samples from apparent healthy turkey 55 E. coli (36.67 %) and 4 Salmonella (2.7%) were isolated and identified using bacteriological and biochemical methods. The Congo red binding assay results were positive in 10 E. coli isolates out of 55 (18.18%) indicating their pathogenicity.


Serological characterization of E. coli and Salmonella isolates

Ten E. coli isolates were serotyped as O86a, O119, O1, O27, O111 and O125 and four Salmonella isolates were typed as Salmonella kentucky.


Determination of antimicrobial susceptibility profiles

The antibiotic sensitivity test revealed E-coli and S.kentucky isolates were 100% resistant to β-Lactames (ampicillin, amoxicillin/clavulanic, cefaclor and ceftazidime) while being 100% sensitive to Carbapenem (imipenem). E. coli and S. kentucky Isolates were 100% and 75% resistant to Phenicols (chloramphenicol), 60% and 75% resistant to Fluoroquinolone (ciprofloxacin), 50% and 50% resistant to Aminoglycoside (gentamicin) while being 10% and 25% resistant to Macrolides (azithromycin) respectively.


Molecular detection of resistance-associated genes

Searching for the antibiotic resistant genes by PCR showed 3 genes (blaTEM, aadB and, floR) were expressed in all isolates of E. coli and S.kentucky. while blaOXA and (qnrA)genes could not found in all isolates.




The incidence of E. coli in the present study was (36.67%). This result coordinated with (Slettemeas et al., 2019) who isolated E. coli from turkey with the percentage (50 %). In contrast, high level of E. coli contamination to turkey meat was obtained by (Davis et al., 2018) at the level (90.7%).


The CR-binding assay indicate that 10 isolates of 55 (18.18%) were positive indicating their pathogenicity due to their ability of invasion. A close result of 28.6% of virulent avian E. coli isolates exhibited CR-binding assay positive was reported by (Amer et al., 2015). This result disagrees with an investigation reported by (Yadaw et al., 2014) who detected (92.86%) of E. coli isolates have Congo red binding ability. The Congo Red binding assay considered a moderately stable, reproducible, and easily distinguishable phenotypic marker. The positive congo-red E. coli isolates serotyped as O1(3), O125(2), O119(2), O111(1), (O86a(1) and O27(1). These isolates nearly similar to investigation by (Circella et al., 2009) who detected O1, O86 from turkey but O111 detected by (Olsen et al., 2011).


Bacterial antimicrobial resistance is a global emerging problem of public health concern. In this study, antibiotic susceptibility testing of E. coli isolates isolates from turkeys showed (100%) resistance to three or more antibiotics. These findings suggest that there are greater antibiotic selective pressures in turkey production. This result is nearly similar to studies conducted by (Cunha et al., 2014) and (Hoepers et al., 2018) who detected 92% and 82% of the isolates being multi-drug resistant (MDR) respectively.


All E. coli isolates were (100%) resistant to ampicillin, cefaclor, ceftazidime, amoxicillin-clavulanic and chloramphenicol and 60% against gentamicin followed by 50% against ciprofloxacin. a finding nearly in agreement with several previous reports obtained by (Giovarnadi et al., 2013) for ampicillin (96%); (Abdallah et al., 2013) for amoxicillin/clavulanic acid (80%) and ciprofloxacin (40%); (Jones et al., 2013) for ciprofloxacin (41.4%) in breeding flocks and (61.4%) in fattening flocks; (Khaitsa et al., 2008) for gentamicin (48%) and (Kaesbohrer et al., 2019) for ciprofloxacin (40%)..On other hand, our results disagreed with (Cunha et al., 2014); for cefotaxime and cefoxitin (10.2% and 5.7%) respectively; (Khaitsa et al., 2008) for ampicillin (22%); (Sheikh et al., 2012) for amoxicillin/clavulanic, chloramphenicol and ciprofloxacin (10.3%, 3.8 % and 0%) respectively; (Abdallah et al., 2013) for ceftazidime (32.5%); (Soufi et al., 2009) for gentamicin and ciprofloxacin(0%,8%) respectively; (Cunha et al., 2014) for gentamicin (19.5%); and (Slettemeas et al., 2019) for gentamicin and chloramphenicol (15.4%) and ( 10.3%) respectively.


An important aspect of this study was to analyze resistance genes in E. coli isolates. In this study, the β-lactamase encoding gene blaTEM conferring resistance to penicillins was detected in 100% of E. coli isolates but blaOXA not detected. These results are close to that reported by (Randall et al., 2010) who detected blaTEM gene of 60.9% rate and conflicts with the result of blaOXA gene (52.1%). On other hand, blaTEM gene was detected by (Sheikh et al., 2012) with low percentage (16.7%) while (Kaesbohrer et al., 2019) failed to detect blaTEM in turkey. This variability in the presence of resistant genes between different localities could be attributed to the previous time of exposure to different types of antibiotics. This also can be attributed to antibiotics regimes implemented in these different locality that cause less or more extensive development of the resistant genes. In our study, the high sensitivity (100%) of E. coli and salmonella isolates to imipenem could be related to the absence of the blaOXA gene in all isolates. Although only 60% of the isolates were resistant to ciprofloxacin, the qnrA gene could not be detected in any of the isolates. This may be explained by the presence of other resistant genes responsible for that part of resistance.This results is in accordance with that obtained by (Randall et al., 2010) and (Gosling et al., 2012). In this study, floR gene associated with chloramphenicol resistance was detected in all isolates. This result was in agreement with the result reported by (Tadeese et al., 2018) who detected floR with a percentage of 66.67%. Gene associated with aminoglycoside resistance (aadB gene) were identified in all gentamicin resistant E. coli. In contrast, aadB gene could not be identified by (Sheikh et al., 2012).


Salmonella infections considered as great danger to human and animal health. In the present study Salmonella spp. were isolated from turkeys with a percentage of 2.7 %. this result is little far from results obtained by (Rahimi, 2012), (Yeh et al., 2017) and (Osman et al., 2010) who isolated Salmonella 6.7%, 11.9% and 12.6% from turkey respectively. Our results are lower than that obtained by (Fakhr et al., 2006) who detected Salmonella in a rate of (40.5%). In the current study, the serotyping of the isolated Salmonella revealed all isolates being Salmonella Kentucky in turkeys. These results coincide with the finding of (Santos et al., 2007) who detected S. Kentucky in most of the isolates.


Among antibiogram, the result showed that all Salmonella isolates were resistant to ampicillin, cefaclor, ceftazidime, amoxicillin-clavulanic in 100%. The resistance to chloramphenicol and ciprofloxacin was 75%, in agreement with the finding of (Yeh et al., 2017) who reported 75.7% and 69.1% resistance against ampicillin and chloramphenicol respectively. This disagree with the finding by Beutlich et al. (2010) who reported low resistance against chloramphenicol; ciprofloxacin and amoxicillin/clavulanic acid to be 9%, 29% and 24% respectively. A high resistance against gentamicin (50%) reported in this study is in contrast to the finding of (Gad et al., 2018) and (Rahimi, 2012) who recorded maximum resistance gentamicin (100%). On the other hand, all Salmonella isolates in this study were sensitive to imipenem 100% followed by 75% to azithromycin in line with the finding of (Nisar et al., 2017) who reported also maximum sensitivity against azithromycin.


Moreover, in this study, all Salmonella isolates expressed blaTEM, aadB and floR (100%) while none of them expressed blaOXA, qnrA. This result is in agreement with (Beutlich et al., 2010) who detected blaTEM, aadB and blaOXA by 100%; 98% and 0% respectively; (Yeh et al., 2017) who detected floR with a percent (63.8%) and disagreed with (Yeh et al., 2017) who detected blaTEM with a percentage of 42%.




In conclusion, the presence of MDR Salmonella kentucky and E. coli in apparent healthy turkey is alarming for the health concern. This mean that healthy turkey farms could be potential spots for development of MDR genes. These farms have the probability of playing a role in the dissemination of antimicrobial resistance among bacterial populations. Thus, considerable efforts need to be taken to precisely control antimicrobial resistance development in turkey and hence guard against human health concerns.



The authors thank the members of the Animal Health Research Institute, Tanta Branch, Egypt for their technical support during the working and analysis of the samples.


Authors Contribution


Ashraf A. Abd El Tawab: shared in the study design,development of methodology and manuscript revision. Amira Mohamed Rizk shared in collection of data, data analysis and interpretation in addition to writing and revision of the manuscript. Seham N. homouda shared in the study design, development of methodology. Emad E. El Mougy shared in the study design, and collection of samples. Alaa M. Gouda shared in samples collection, methodology and writing of the manuscript.


Conflict of interest

The authors declare that they have no conflict of interests. The authors declared that they did not have any funding source to support their study.




  • Abdellah EA, Fouzia RF, Bouchra O (2013). Prevalence and antibiogram study of Escherichia coli and Staphylococcus aureus in turkey meat in Morocco. Pharmaceut. Anal. Acta. 4: 270.
  • Amer MM, Bastamy M, Elbayoumi KM, Mervat S (2015). Isolation and characterization of avian pathogenic Escherichia coli from broiler chickens in some Governorates of Egypt. Vet. Med. J. Giza (VMJG), 61(1): 1-7.
  • Aslam M, Checkley S, Avery B, Chalmers G, Bohaychuk V, Gensler G, Reid-Smith R, Boerlin P (2012). Phenotypic and genetic characterization of antimicrobial resistance in Salmonella serovars isolated from retail meats in Alberta, Canada. Food Microbiol., 32(1): 110–117.
  • Berkhoff HA, Vinal AC (1986). Congo red medium to distinguish between invasive and non-invasive Escherichia coli for poultry. Avian Dis., 30: 117-121.
  • Beutlich J, Rodríguez IN, Schroeter AD, Käsbohrer A, Helmuth R, Guerra, BS (2010). A predominant multidrug-resistant Salmonella enterica serovar Saintpaul clonal line in German turkey and related food products. Appl. Environ. Microbiol., 76(11): 3657-3667.
  • Centers for Disease Control and Prevention (CDC) (2011). Investigation update: Multistate outbreak of human Salmonella Heidelberg infections linked to turkey.
  • Center for Science in the Public Interest (CSPI) (2013). Risky meat: A CSPI field guide to meat and poultry safety.
  • Chinivasagam HN, M Redding M, Runge G, Blackall PJ (2010). Presence and incidence of food-borne pathogens in Australian chicken litter. Br. Poult. Sci. 51: 311–318.
  • Circella E, Pennelli D, Tagliabue S, Ceruti R, Giovanardi D, Camarda A (2009). Virulence –associated genes in Avian Pathogenic Escherichia coli of turkey. Italian Journal of Animal Science, 8(4): 775–779.
  • Colom K, Pèrez J, Alonso R, Fernández-A, Lariňo E, Cisterna R (2003). Simple and reliable multiplex PCR assay for detection of blaTEM, blaSHV and blaOXA-1 genes in Enterobacteriaceae. FEMS Microbiol. Lett. 223: 147-151.
  • Cunha-Neto AD, Carvalho LA, Carvalho RC, Rodrigues DD, Mano SB, Figueiredo EE, Conte-Junior CA (2018). Salmonella isolated from chicken carcasses from a slaughterhouse in the state of Mato Grosso ,Brazil: antibiotic resistance profile, serotyping, and characterization by repetitive sequence-based PCR system. Poult. Sci., 97(4): 1373-1381.
  • Davis GS, Waits K, Nordstrom L, Grande H, Weaver B, Papp K, Horwinski J, Koch B, Hungate BA, Liu CM, Price LB (2018). Antibiotic-resistant Escherichia coli from Retail Poultry Meat with Different Antibiotic Use Claims. BMC Microbiol.,18(174): 1-7.
  • Doublet B, Lailler R, Meunier D, Brisabois A, Boyd D, Mulvey MR, Chaslus-Dancla E, Cloeckaert A (2003). Variant Salmonella Genomic Island 1 Antibiotic Resistance Gene Cluster in Salmonella enteric Serovar Albany. Emerg. Infect. Dis. 9(5): 585-591.
  • El-Adawy H, Hotzel H, Düpre S, Tomaso H, Neubauer H, Hafez HM (2012). Determination of antimicrobial sensitivities of Campylobacter jejuni isolated from commercial turkey farms in Germany. Avian Dis. 56: 685–692.
  • Fakhr MK, Sherwood JS, Thorsness J, Logue CM (2006). Molecular characterization and antibiotic resistance profiling of Salmonella isolated from retail turkey meat products. Foodborne Pathog. Dis. 3: 366–374.
  • Frana TS, Carlson SA, Griffith RW (2001). Relative distribution and conservation of genes encoding aminoglycoside-modifying enzymes in Salmonella enterica serotype Typhimurium phage type DT104. Appl. Environ. Microbiol. 67: 445–448.
  • Gad AH, Abo-Shama UH, Harclerode KK, Fakhr MK (2018). Prevalence, serotyping, molecular typing, and antimicrobial resistance of salmonella isolated from conventional and organic retail ground poultry. Front. Microbiol. 9: 2653.
  • Giovanardi D, Lupini C, Pesente P, Rossi G, Ortali G, Catelli E (2013). Characterization and antimicrobial resistance analysis of avian pathogenic Escherichia coli isolated from Italian turkey flocks. Poult. Sci. 92(10); 2661–2667.
  • Gosling RJ, Clouting CS, Randall LP, Horton RA, Davies RH (2012). Ciprofloxacin resistance in E. coli isolated from turkeys in Great Britain. Avian Pathol. 41: 83–89.
  • Hoepers PG, Silva PL, Rossi DA, Valadares Júnior EC, Ferreira BC, Zuffo JP, Fonseca BB (2018). The association between extended spectrum beta-lactamase (ESBL) and ampicillin C (AmpC) beta-lactamase genes with multidrug resistance in Escherichia coli isolates recovered from turkeys in Brazil. Br. Poult. Sci., 59(4): 396–401.
  • ISO 6579 (2002). Microbiology of food and animal feeding stuffs- horizontal method for the detection of Salmonella SPP, Int. Stand., 4th Ed., pp. 7- 15.
  • Jones EM, Snow LC, Carrique-Mas JJ, Gosling RJ, Clouting C, Davies RH (2013). Risk factors for antimicrobial resistance in Escherichia coli found in GB turkey flocks. Vet. Rec. 173(17): 422–422.
  • Käsbohrer A, Bakran-Lebl K, Irrgang A, Fischer J, Kämpf P, Schiffmann AP, Werckenthin CS, Busch M, Kreienbrock L, Hille K (2019). Diversity in prevalence and characteristics of ESBL/pAmpC producing E. coli in food in Germany. Vet. Microbiol., 233: 52-60.
  • Khaitsa ML, Oloya J, Doetkott DM, Kegode RB (2008). Antimicrobial resistance and association with class 1 integrons in Escherichia coli isolated from turkey meat products. J. Food Prot., 71(8): 1679-1684.
  • Konemann E, Allen S, Janda W, Schreckenberger C, Winn W (1997). Color Atlas and text book of diagnostic Microbiology. Fifth Edition. Lippincott, Philadelphia, New York. pp. 55-73.
  • Malkawi H (2003). Molecular identification of Salmonella isolates from poultry and meat products in Ibrid City, Jordan. World J. Microbiol. Biotechnol. 19: 455-459.
  • Moawad AA, Hotzel H, Awad OF, Tomaso H, Neubauer H, Hafez HM, and El-Adawy H (2017). Occurrence of Salmonella enterica and Escherichia coli in raw chicken and beef meat in northern Egypt and dissemination of their antibiotic resistance markers. Gut Pathogens.
  • NARMS Integrated Report (2014). The National Antimicrobial Resistance Monitoring System: Enteric Bacteria.
  • National Committee for clinical laboratory standard “NCCLS” (2002). Performance standards for antimicrobial disc susceptibility test. 7th edition approved standard M 2. A 8, National committee for clinical laboratory standards.
  • National Committee for clinical laboratory standard (NCCLS) (2016). Performance Standards for antimicrobial disks susceptibility tests, CLSI vol. 36 no.1.
  • Nhung N, Cuong N, Thwaites G, Carrique-Mas J (2016). Antimicrobial Usage and Antimicrobial Resistance in Animal Production in Southeast Asia: A Review. Antibiot., 5(4): 37.
  • Nisar MF, Kassem II, Rajashekara G, Goyal SM, Lauer DC, Voss SJ, Nagaraja KV (2017). Genotypic relatedness and antimicrobial resistance of Salmonella Heidelberg isolated from chickens and turkeys in the midwestern United States. Journal of veterinary diagnostic investigation. Off. Publ. Am. Assoc. Vet. Lab. Diagnosticians, Inc, 29(3): 370-375.
  • Olsen RH, Chadfield MS, Christensen JP, Scheutz F, Christensen H, Bisgaard M (2011). Clonality and virulence traits of Escherichia coli associated with haemorrhagic septicaemia in turkeys. Avian Pathol. 40(6): 587–595.
  • Osman KM, Yousef AMM, Aly MM, Radwan MI (2010). Salmonella spp. Infection in Imported 1-Day-Old Chicks, Ducklings, and Turkey Poults: A Public Health Risk. Foodborne Pathog. Dis., 7(4): 383–390.
  • Popoff MY, Bockemühl J, Gheesling LL (2004). Supplement 2002 (no. 46) to the Kauffmann–White scheme. Res. Microbiol. 155(7): 568–570.
  • Qunin PJ, Markey BK, Carter ME, Donnelly WJC, Leonard CF (2002). VET. Microbiology and Microbial disaese textbook, MPG Books LTd, Bodmin, Cornwall pp. 111.
  • Rahimi E (2012). Prevalence and Antimicrobial Resistance of Salmonella spp. Isolated from Retail Chicken, Turkey, and Ostrich By-Products in Iran. Rev. Med. Vet. 163: 271-275.
  • Randall LP, Clouting C, Horton RA, Coldham NG, Wu GW, Clifton-Hadley FA, Davies RH, Teale C (2010). Prevalence of Escherichia coli carrying extended-spectrum β-lactamases (CTX-M and TEM-52) from broiler chickens and turkeys in Great Britain between 2006 and 2009.  J. Antimicrob. Chemother., 66(1): 86-95.
  • Robicsek A, Jacoby GA, Hooper DC (2006). The worldwide emergence of plasmid-mediated quinolone resistance. Lancet Infect. Dis., 6(10): 629–640.
  • Santos FB, Dsouza DH, Gibson KE, Ferket PR, Sheldon BW (2007). Genotypes, serotypes, and antibiotic resistance profiles of Salmonella isolated from commercial North Carolina turkey farms. J. Food Prot., 70(6): 1328-1333.
  • Sheikh AA, Checkley S, Avery B, Chalmers G, Bohaychuk V, Boerlin P, Reid-Smit R, Aslam M (2012). Antimicrobial Resistance and Resistance Genes in Escherichia coli Isolated from Retail Meat Purchased in Alberta, Canada. Foodborne Pathog. Dis., 9(7): 625–631.
  • Simoneit C, Burow E, Tenhagen BA, Käsbohrer A (2015). Oral administration of antimicrobials increase antimicrobial resistance in E. coli from chicken – A systematic review. Prev. Vet. Med. 118(1): 1–7.
  • Soufi L, Abbassi MS, Sá enz Y, Vinué L, Somalo S, Zarazaga M, Abbas A, Dbaya R, Khanfir L, Hassen AB, Hammami H, Torres C (2009). Prevalence and Diversity of Integrons and Associated Resistance Genes in Escherichia coli Isolates from Poultry Meat in Tunisia. Foodborne Pathog. Dis., 6: 1067–1073.
  • Slettemeås JS, Sunde M, Ulstad CR, Norstro¨m M, Wester AL, Urdahl AM (2019). Occurrence and characterization of quinolone resistant Escherichia coli from Norwegian turkey meat and complete sequence of an IncX1 plasmid encoding qnrS1. PLoS ONE. 14(3): e0212936.
  • Tadesse DA, Li C, Mukherjee S, Hsu C, Jones SB, Gaines SA., Kabera C, Loneraga GH, Torrence ME, Harhay DM, Mcdermott PF, Zhao S (2018). Whole-Genome Sequence Analysis of CTX-M Containing Escherichia coli Isolates from Retail Meats and Cattle in the United States. Microbial drug resistance.
  • Yadav V, Joshi RK, Joshi N, Diwakar RP (2014). Congo red binding and plasmid profile of E. coli isolates of poultry origin. J. Anim. Health Prod. 2(3): 31 – 32.
  • Yeh, J, Chen C, Chiou C, Lo D, Cheng J, Kuo H (2017). Comparison of prevalence, phenotype, and antimicrobial resistance of serovars isolated from turkeys in Taiwan. Poult. Sci., 97(1): 279-288.