Virulence factors and phylogenetic group profile of uterine Escherichia coli in early postpartum of high-producing dairy cows

Author(s)

Bicudo, Luana de Cassia ^[1] ; Oba, Eunice ^[1] ; Bicudo, Sony Dimas ^[1] ; Leite, Domingos da Silva ^[2] ; Siqueira, Amanda Keller ^[2] ; de Souza Monobe, Marina Mitie ^[3] ; Nogueira, Meghi ^[2] ; de Figueiredo Pantoja, Jose Carlos ^[4] ; Paganini Listoni, Fernando Jose ^[4] ; Ribeiro, Marcio Garcia ^[4]

Affiliation

^[1] Sao Paulo State Univ UNESP, Sch Vet Med & Anim Sci FMVZ, Dept Anim Reprod & Vet Radiol, Prof Doutor Walter Mauricio Correa St, BR-18618681 Botucatu, SP - Brazil

^[2] Univ Estadual Campinas, Inst Biol, Dept Genet Evolut & Bioagents, 255 Monteiro Lobato St, Postal Address 6109, BR-13083862 Campinas, SP - Brazil

^[3] Sao Paulo State Univ UNESP, Sch Vet Med & Anim Sci FMVZ, Dept Vet Clin, Prof Doutor Walter Mauricio Correa St, BR-18618681 Botucatu, SP - Brazil

^[4] Sao Paulo State Univ UNESP, Sch Vet Med & Anim Sci FMVZ, Dept Vet Hyg & Publ Hlth, Prof Doutor Walter Mauricio Correa St, BR-18618681 Botucatu, SP - Brazil

• Document type: Journal article
• Source: ANIMAL PRODUCTION SCIENCE; v. 59, n. 10, p. 1898-1905, 2019.
• Web of Science Citations: 0

Abstract

Escherichia coli is the most common contaminant of the bovine uterus in the first few weeks postpartum, and one of the most important pathogens involved in uterine infections. This bacterium is characterised by diverse virulence factors (VF); however, the profile of E. coli VF in physiologic postpartum uterine contamination is not well established. Therefore, the present study aimed to investigate the prevalence of intrauterine bacteria, a set of virulence factors and phylogroups of E. coli isolates, leukogram and uterine cytology in 75 Holstein cows at 24 h (Sampling time 1) and 14 days (Sampling time 2) postpartum. Escherichia coli, alpha-haemolytic Streptococcus, Trueperella pyogenes, and Pasteurella multocida were the most common microorganisms isolated in pure culture, whereas E. coli and Clostridium perfringens Type A, E. coli and alpha-haemolytic Streptococcus, and E. coli and Proteus mirabilis were the most frequent microorganisms in mixed colonies at both studied sampling times. In the 59 E. coli isolates after 24 h (n = 35) and 14 days (n = 24) postpartum, the genes detected for VF were fimH, iucD/aer, kps, hlyA, usp, vt1 and vt2. Most E. coli strains detected in both moments of study belonged to Commensal phylogenetic groups A and B1, whereas Pathogenic groups D and B2 were identified at 24 h and 14 days postpartum respectively. All cows presented suitable immune response against the presence of bacteria in uterine lumen, observed by leukocytosis, neutrophilia, lymphocytosis and monocytosis at leukogram and a high number of polymorphonuclear leukocytes in uterine cytology, in both studied moments. Thus, a complex diversity of aerobic and anaerobic bacteria is involved in uterine contamination in the early postpartum of cows, besides the predominance of E. coli. Moreover, the genes fimH, iucD/aer, hlyA, kps, usp, vt1 and vt2 play a key role in the virulence of E. coli in this period. (AU)

• FAPESP's process: 11/15852-7 - Profile characterization of virulence factors in Escherichia coli isolated from the uterus after calving and its relation to the uterine microflora present in the second week postpartum in Holstein cows
• Grantee: Luana de Cássia Bicudo
• Support Opportunities: Scholarships in Brazil - Master