Next Article in Journal
Digestibility of Amino Acids in Protein-Rich Feed Ingredients Originating from Animals, Peanut Flour, and Full-Fat Soybeans Fed to Pigs
Next Article in Special Issue
Immunomodulatory Effects of Dietary Phosphorus and Calcium in Two Strains of Laying Hens
Previous Article in Journal
Psychological Stress, Its Reduction, and Long-Term Consequences: What Studies with Laboratory Animals Might Teach Us about Life in the Dog Shelter
Previous Article in Special Issue
Impact of Housing Environment on the Immune System in Chickens: A Review

Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal

Central Department of Microbiology, Tribhuvan University, Kirtipur, Kathmandu 44618, Nepal
Central Veterinary Laboratory Ministry of Agriculture, Land Management and Cooperatives, Government of Nepal, Tripureshwor, Kathmandu 44618, Nepal
Centre for Tropical Medicine and Global Health, Nuffield Department of Medicine, University of Oxford, Oxford OX1 3SY, UK
Author to whom correspondence should be addressed.
These authors have equally contributed in this study.
Animals 2020, 10(11), 2060;
Received: 30 August 2020 / Revised: 22 October 2020 / Accepted: 25 October 2020 / Published: 7 November 2020
(This article belongs to the Special Issue Poultry Microbiology and Immunology)
The poultry industry is one of the top agribusinesses in Nepal. However, despite the government’s restriction on the use of antibiotics as growth promotors in animals, the overuse and misuse of antibiotics can be seen all over the country. Such inappropriate use of antibiotics has led to the rise of antibiotic resistance among treatment options for both human and animal pathogens. Several findings suggest the failure of colistin, a polymyxin E antibiotic (once regarded as the last resort drug), in the treatment of human bacterial infections is due to the emergence and spread of the plasmid-mediated colistin resistance gene (mcr-1) among Gram-negative bacterial pathogens. The emergence and rapid transfer of resistant strains in poultry farms are associated with unwanted loss of livestock, economic burden and spread of drug-resistance to other animals, humans and the environment, as well. In this study, we characterized the mcr-1 gene from infected chicken livers, where prevalence was found to be alarmingly high. This study identifies the result of regulatory failures. Therefore, this report provides valuable reference to the policy makers so that a more effective policy can be formulated and implemented to curb the spread of drug-resistant pathogens.
Background: Plasmid-mediated resistance to the colistin in poultry is considered as an emerging problem worldwide. While poultry constitutes the major industry in Nepal, there is a paucity of evidence on colistin resistance in Escherichia coli isolates causing natural infections in poultry. This study aimed to explore the prevalence of plasmid-mediated colistin resistance gene, mcr-1 in E. coli isolated from liver samples of dead poultry suspected of E. coli infections. Methods: A total of two hundred and seventy liver samples (227 broilers and 43 layers) from dead poultry suspected of colibacillosis were collected from post-mortem in the Central Veterinary Laboratory (CVL), Kathmandu, between 1 February and 31 July 2019. The specimens were processed to isolate and identify E. coli; an antimicrobial susceptibility test (AST) using disk diffusion method was performed with 12 different antibiotics: Amikacin (30 µg), ampicillin (10 µg), ciprofloxacin (5 µg), chloramphenicol (30 µg), cefoxitin (30 µg), ceftazidime (30 µg), ceftriaxone (30 µg), cotrimoxazole (25 µg), gentamicin (10 µg), imipenem (10 µg), levofloxacin (5 µg) and tetracycline (30 µg). Colistin resistance was determined by agar dilution method and colistin-resistant strains were further screened for plasmid-mediated mcr-1 gene, using conventional polymerase chain reaction (PCR). Results: Out of 270 liver samples, 53.3% (144/270) showed growth of E. coli. The highest number (54%; 109/202) of E. coli isolates was obtained in the liver samples from poultry birds (of both types) aged less than forty days. In AST, 95.1% (137/144) and 82.6% (119/144) of E. coli isolates were resistant against tetracycline and ciprofloxacin, respectively, while 13.2% (19/144) and 25.7% (37/144) isolates were resistant to cefoxitin and imipenem, respectively. In the same assay, 76.4% (110/144) E. coli isolates were multi-drug resistant (MDR). The phenotypic prevalence of colistin resistance was 28.5% (41/144). In the PCR assay, 43.9% (18/41) of colistin-resistant isolates were screened positive for plasmid-mediated mcr-1. Conclusion: The high prevalence of mcr-1 in colistin-resistant E. coli isolates in our study is a cause of concern for the probable coming emergence of colistin resistance in human pathogens, due to horizontal transfer of resistant genes from poultry to human isolates. View Full-Text
Keywords: Escherichia coli; colistin resistance; MDR; mcr-1 Escherichia coli; colistin resistance; MDR; mcr-1
Show Figures

Figure 1

MDPI and ACS Style

Bista, S.; Thapa Shrestha, U.; Dhungel, B.; Koirala, P.; Gompo, T.R.; Shrestha, N.; Adhikari, N.; Joshi, D.R.; Banjara, M.R.; Adhikari, B.; Rijal, K.R.; Ghimire, P. Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal. Animals 2020, 10, 2060.

AMA Style

Bista S, Thapa Shrestha U, Dhungel B, Koirala P, Gompo TR, Shrestha N, Adhikari N, Joshi DR, Banjara MR, Adhikari B, Rijal KR, Ghimire P. Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal. Animals. 2020; 10(11):2060.

Chicago/Turabian Style

Bista, Sayara; Thapa Shrestha, Upendra; Dhungel, Binod; Koirala, Pragya; Gompo, Tulsi R.; Shrestha, Nabaraj; Adhikari, Nabaraj; Joshi, Dev R.; Banjara, Megha R.; Adhikari, Bipin; Rijal, Komal R.; Ghimire, Prakash. 2020. "Detection of Plasmid-Mediated Colistin Resistant mcr-1 Gene in Escherichia coli Isolated from Infected Chicken Livers in Nepal" Animals 10, no. 11: 2060.

Find Other Styles
Note that from the first issue of 2016, MDPI journals use article numbers instead of page numbers. See further details here.

Article Access Map by Country/Region

Search more from Scilit
Back to TopTop