## 4 Discussion  
Different _E. coli_ pathotypes are related to diarrhea in both human and animal populations with some serotypes capable of causing outbreaks [6,32]. In this work, several serotypes associated with diarrhea in humans in Mexico and other countries were found (O8:NM, O76:H19 and O146:H21) [32,33]. Moreover, serotypes O6:NM, O91:H10, and O104:H2 have been related to HUS. It is important to highlight that serotype O146:H21 was found in sheep from farms and slaughterhouses in Brazil [34,35], while the same serotype can be found in Mexico backyard sheep or adult sheep from Norway [36,37]. Similarly, the serogroup O104 is considered of clinical importance in the European Economic Community; interestingly, this serogroup is disseminated in lambs and sheep from India and lambs in Mexico [38, 39, 40, 41]. According to [PERSON] et al. (2011) [42], 40% of putative pathogenic _E. coli_ belongs to pathotype STEC (non-O157) and is the major agent of microbial contaminations in meat products in Europe and USA [43,44]. In this work, STEC was the most frequent pathotype (47.7%) in sheep slaughtered in the abattoir; this finding is similar to that reported in Brazil \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline \multirow{2}{*}{**Isolate**} & \multirow{2}{*}{**Serotype**} & \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Source**} & \multirow{2}{*}{**Entimate**} & \multirow{2}{*}{**Entimate**} & \multirow{2}{*}{**Entimate**} & \multicolumn{3}{c}{**Antimicrobial**} & \multicolumn{3}{c}{**Resistance Gene**} \\ \cline{6-10}  & & & & & & & **Resistance Profile** & _tetA_ & _tetB_ & _su11_ & _su12_ \\ \hline C23 & O146:H21 & rectal & + & & & NIT, AMP & & & & \\ Z5 & O174:H16 & rectal & + & & & NIT, AMP & & & & \\ Z25 & O174:H16 & rectal & + & & & NIT, AMP & & & & + \\ B3 & O176:NM & rectal & + & & NIT, AMP & & & & & \\ C24 & O185:NM & rectal & + & & NIT, AMP & & & + & \\ E15B & O32:H27 & rectal & + & & & NIT, AMP & & & & \\ E20 & O32:H7 & rectal & + & & & NIT, AMP & & & & \\ E30 & O34:O145:H45 & rectal & + & & & NIT, AMP & & & & \\ Z16 & O37:H10 & rectal & + & & NIT, AMP & & & & \\ B1 & O6:H16 & rectal & + & & NIT, AMP & & & & \\ B15 & O6:NM & rectal & + & & NIT, AMP & & & & \\ Z17 & O76:H19 & rectal & + & & NIT, AMP & & & & \\ Z32 & O76:H19 & rectal & + & & NIT, AMP & & & & \\ Z34 & O76:H19 & rectal & + & & NIT, AMP & & & & \\ E18 & O8:H2 & rectal & + & & NIT, AMP & & + & \\ C27 & O91:H10 & rectal & + & & NIT, AMP & + & & \\ Z12 & O91:H28 & rectal & + & & NIT, AMP & & & & \\ Z13 & O91:H42 & rectal & + & & NIT, AMP & & & & \\ Z14 & O91:H47 & rectal & + & & NIT, AMP & & & & \\ Z18 & O91:H47 & rectal & + & & NIT, AMP & & & & \\ C3 & O96:H20 & carcass & + & & NIT, AMP & & & & \\ V13 & O146:H10 & rectal & + & & NIT, TET & & & & \\ V5 & O176:H21 & rectal & + & & NIT, TET & & & & \\ C28B & -:H14 & rectal & + & & NIT & & & & \\ Z29 & -:H16 & rectal & + & & NIT & & & & \\ Z19 & O146:H21 & rectal & + & & & NIT & & & \\ B13C & O150:NM & carcass & + & & & NIT & & & \\ Z20 & O70:H10 & rectal & + & & NIT & & & & \\ Z21 & O76:H19 & rectal & + & & NIT & & & & \\ Z2 & -:H34 & rectal & + & & NIT, AMP, TET, SXT & + & & \\ D3 & -:H34 & carcass & + & & NIT, AMP, TET, SXT & & & & \\ Z15 & -:H10 & rectal & + & & NIT, AMP & & & & \\ D53 & O28 AC:H21 & carcass & + & & NIT, AMP & & & & \\ D15 & O105 AB:H16 & carcass & & + & NIT, AMP, TET & & & & \\ D15B & O120:H16 & carcass & & + & NIT, AMP & & & & \\ E3 & O28 AC:H21 & rectal & & + & NIT, AMP, TET & & & & \\ \hline \end{tabular}
\end{table} 
Table 5: _Cont._in sheep abattoirs (11.3%), or slaughter-age sheep from Australia (72%), and with other ruminants like goats in Kenya (50%), Iran (16.4%) or bovines in Burkina Faso (37%) and Mexico (40.7%) [14; 16; 34; 45; 46; 47]. The most frequent _stx_ subtype gene described worldwide in sheep is _stx1c_[48; 49; 50]. The results of our investigation corroborate this statement, however, a small number of isolates carried _stx1a_ and _stx1d_. The _stx1c_ subtype gene is related to diarrhea without complications in humans [9].