Characterisation of Commensal Escherichia coli Isolated from Apparently Healthy Cattle and Their Attendants in Tanzania

Abstract

While pathogenic types of Escherichia coli are well characterized, relatively little is known about the commensal E. coli flora. In the current study, antimicrobial resistance in commensal E. coli and distribution of ERIC-PCR genotypes among isolates of such bacteria from cattle and cattle attendants on cattle farms in Tanzania were investigated. Seventeen E. coli genomes representing different ERIC-PCR types of commensal E. coli were sequenced in order to determine their possible importance as a reservoir for both antimicrobial resistance genes and virulence factors. Both human and cattle isolates were highly resistant to tetracycline (40.8% and 33.1%), sulphamethazole-trimethoprim (49.0% and 8.8%) and ampicillin (44.9% and 21.3%). However, higher proportion of resistant E. coli and higher frequency of resistance to more than two antimicrobials was found in isolates from cattle attendants than isolates from cattle. Sixteen out of 66 ERIC-PCR genotypes were shared between the two hosts, and among these ones, seven types contained isolates from cattle and cattle attendants from the same farm, suggesting transfer of strains between hosts. Genome-wide analysis showed that the majority of the sequenced cattle isolates were assigned to phylogroups B1, while human isolates represented phylogroups A, C, D and E. In general, in silico resistome and virulence factor identification did not reveal differences between hosts or phylogroups, except for lpfA and iss found to be cattle and B1 phylogroup specific. The most frequent plasmids replicon genes found in strains from both hosts were of IncF type, which are commonly associated with carriage of antimicrobial and virulence genes. Commensal E. coli from cattle and attendants were found to share same genotypes and to carry antimicrobial resistance and virulence genes associated with both intra and extraintestinal E. coli pathotypes.

Metagenomic analysis of enteric bacterial pathogens affecting the performance of dairy cows in smallholder productions systems

“…The present study identified the abundance of tetracycline resistance genes from cow fecal isolates. These findings are in agreement with the results by Thames et al, (2012), Agga et al (2015), Gerzova et al (2015), Iweriebor et al (2015), Madoshi et al (2016) and Pitta et al (2016) who reported high presence of tetC, tetG, tetO, tetW, and tetX in their studies. The findings are also similar to the results reported by Kyselkova et al (2015) when studying the occurrence of tetracycline resistance genes at conventional dairy farm.…”

“…Similar findings were reported by Thames et al (2012) who reported the tetC, tetG, tetO, tetW, and tetX as antimicrobial resistance genes corresponding to tetracycline, ermB, ermF for macrolide, and sul1 and sul2 for sulfonamide identified from dairy calves manures. These findings are in agreement with the results by Agga et al (2015), Gerzova et al (2015), Iweriebor et al (2015), Madoshi et al (2016) and Pitta et Ahmed and Shimamoto (2011) and Chandra et al (2014) who reported blaCTX-M, blaTEM, blaCMY, blaSHV and blaOXA as the predominant genes in their studies. The presence of a high number of genes that confer resistance to these antimicrobials can be explained by indiscriminate use of these drugs in the treatment of diseased animals, prevention of diseases in the farms or with their use as growth promoters in animal feed production Akindolire et al, 2015;Pandey et al, 2015;Cameron and McAllister, 2016).…”

“…This pathogenic bacterium was also identified in the cow fecal samples in other studies by Pandey at al. (2015), Madoshi et al (2016) and Bako et al (2017). Furthermore, E. coli were identified also by Megersha et al (2009) and Amadi et al (2015) in Ethiopia and Grenada in the feces of sheep and goats, respectively.…”

“…In the Enterobacteriaceae, Escherichia coli, Salmonella enterica and Klebsiella pneumonia was detected. E. coli is among the zoonotic bacterial pathogens that cause subclinical mastitis and commonly affects dairy cows during parturition leading them to the local or acute mastitis (Sandra Bjork, 2013;Osman et al, 2014;Madoshi et al, 2016;Hintong et al, 2017). It is excreted in the feces of healthy animal and spreads to the farm via soil or water (Amadi et al, 2015).…”

Genome-Based Analysis of Extended-Spectrum β-Lactamase-Producing Escherichia coli in the Aquatic Environment and Nile Perch (Lates niloticus) of Lake Victoria, Tanzania

“…The additional virulence genes shown by C2 and C3 strains included nfaE, which is essential for diffuse adherence fimbrillar adhesin; iss plays a significant role in increased serum survival; and the vat gene is important for vacuolating autotransporter toxin in host cells for pathogenicity processes. These virulence genes were previously reported from E. coli in humans as well as from pigs and bovine (Szmolka et al, 2012;Madoshi et al, 2016;Ahmed et al, 2017). The lpf A gene is important for long polar fimbriae and has been commonly associated with the ability to invade epithelial cells in animals and humans (Dogan et al, 2012).…”