In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets
Colibacillosis in nursery pigs, caused by <i>Escherichia coli</i> (ETEC, EPEC, and STEC pathotypes), remains a major economic concern in the swine industry. This study evaluated the effects of in-feed or in-water chlortetracycline (CTC) administration on the fecal prevalence of virulence...
Saved in:
| Main Authors: | , , , , , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-05-01
|
| Series: | Microorganisms |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2076-2607/13/6/1185 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850168276046315520 |
|---|---|
| author | Ramya Kalam Raghavendra G. Amachawadi Xiaorong Shi Jianfa Bai Mina Abbasi Mike D. Tokach Tiruvoor G. Nagaraja |
| author_facet | Ramya Kalam Raghavendra G. Amachawadi Xiaorong Shi Jianfa Bai Mina Abbasi Mike D. Tokach Tiruvoor G. Nagaraja |
| author_sort | Ramya Kalam |
| collection | DOAJ |
| description | Colibacillosis in nursery pigs, caused by <i>Escherichia coli</i> (ETEC, EPEC, and STEC pathotypes), remains a major economic concern in the swine industry. This study evaluated the effects of in-feed or in-water chlortetracycline (CTC) administration on the fecal prevalence of virulence genes and pathotypes associated with colibacillosis. A total of 1296 weaned piglets (21 days old) were allocated to 48 pens (16 pens/treatment; 27 piglets/pen) and assigned randomly to no CTC, in-feed CTC, or in-water CTC groups. CTC was administered from days 0 to 14. Fecal samples from five piglets per pen on days 0, 14, and 28 were enriched, screened by 11-plex PCR, cultured for pathotypes, and tested for CTC susceptibility and tetracycline resistance genes. None of the 360 fecal samples or 3267 <i>E. coli</i> isolates were positive for <i>bfpA</i> or <i>aggA</i>. Prevalence of <i>estB</i> (96.9%) and <i>astA</i> (92.8%) was highest. ETEC was the dominant pathotype (41.2%), with <i>astA</i> (29%) and <i>estB</i> (21.9%) as predominant enterotoxin genes. CTC administration had no significant effect on fecal prevalence of virulence genes or pathotypes (<i>p</i> > 0.05). <i>stx2</i> and STEC were detected only at day 28, all harboring <i>stx2e</i>. All pathotypes were CTC-resistant, with <i>tetA</i> as the predominant resistance gene. |
| format | Article |
| id | doaj-art-1d4c3fdc9f8b4e52a9bdaea5a23cf98a |
| institution | OA Journals |
| issn | 2076-2607 |
| language | English |
| publishDate | 2025-05-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Microorganisms |
| spelling | doaj-art-1d4c3fdc9f8b4e52a9bdaea5a23cf98a2025-08-20T02:20:59ZengMDPI AGMicroorganisms2076-26072025-05-01136118510.3390/microorganisms13061185In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in PigletsRamya Kalam0Raghavendra G. Amachawadi1Xiaorong Shi2Jianfa Bai3Mina Abbasi4Mike D. Tokach5Tiruvoor G. Nagaraja6Department of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USADepartment of Clinical Sciences, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USADepartment of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USAKansas State Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USADepartment of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USADepartment of Animal Sciences and Industry, College of Agriculture, Kansas State University, Manhattan, KS 66506, USADepartment of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS 66506, USAColibacillosis in nursery pigs, caused by <i>Escherichia coli</i> (ETEC, EPEC, and STEC pathotypes), remains a major economic concern in the swine industry. This study evaluated the effects of in-feed or in-water chlortetracycline (CTC) administration on the fecal prevalence of virulence genes and pathotypes associated with colibacillosis. A total of 1296 weaned piglets (21 days old) were allocated to 48 pens (16 pens/treatment; 27 piglets/pen) and assigned randomly to no CTC, in-feed CTC, or in-water CTC groups. CTC was administered from days 0 to 14. Fecal samples from five piglets per pen on days 0, 14, and 28 were enriched, screened by 11-plex PCR, cultured for pathotypes, and tested for CTC susceptibility and tetracycline resistance genes. None of the 360 fecal samples or 3267 <i>E. coli</i> isolates were positive for <i>bfpA</i> or <i>aggA</i>. Prevalence of <i>estB</i> (96.9%) and <i>astA</i> (92.8%) was highest. ETEC was the dominant pathotype (41.2%), with <i>astA</i> (29%) and <i>estB</i> (21.9%) as predominant enterotoxin genes. CTC administration had no significant effect on fecal prevalence of virulence genes or pathotypes (<i>p</i> > 0.05). <i>stx2</i> and STEC were detected only at day 28, all harboring <i>stx2e</i>. All pathotypes were CTC-resistant, with <i>tetA</i> as the predominant resistance gene.https://www.mdpi.com/2076-2607/13/6/1185colibacillosischlortetracycline<i>Escherichia coli</i>pathotypesPCRpiglets |
| spellingShingle | Ramya Kalam Raghavendra G. Amachawadi Xiaorong Shi Jianfa Bai Mina Abbasi Mike D. Tokach Tiruvoor G. Nagaraja In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets Microorganisms colibacillosis chlortetracycline <i>Escherichia coli</i> pathotypes PCR piglets |
| title | In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets |
| title_full | In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets |
| title_fullStr | In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets |
| title_full_unstemmed | In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets |
| title_short | In-Feed vs. In-Water Chlortetracycline Administration on the Fecal Prevalence of Virulence Genes and Pathotypes of <i>Escherichia coli</i> Involved in Enteric Colibacillosis in Piglets |
| title_sort | in feed vs in water chlortetracycline administration on the fecal prevalence of virulence genes and pathotypes of i escherichia coli i involved in enteric colibacillosis in piglets |
| topic | colibacillosis chlortetracycline <i>Escherichia coli</i> pathotypes PCR piglets |
| url | https://www.mdpi.com/2076-2607/13/6/1185 |
| work_keys_str_mv | AT ramyakalam infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT raghavendragamachawadi infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT xiaorongshi infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT jianfabai infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT minaabbasi infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT mikedtokach infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets AT tiruvoorgnagaraja infeedvsinwaterchlortetracyclineadministrationonthefecalprevalenceofvirulencegenesandpathotypesofiescherichiacoliiinvolvedinentericcolibacillosisinpiglets |