Variation in the Distribution of Putative Virulence and Colonization Factors in Shiga Toxin-Producing Escherichia coli Isolated from Different Categories of Cattle

Abstract

Shiga toxin-producing Escherichia coli (STEC) are pathogens of significant public health concern. Several studies have confirmed that cattle are the main reservoir of STEC in Argentina and other countries. Although Shiga toxins represent the primary virulence factors of STEC, the adherence and colonization of the gut are also important in the pathogenesis of the bacteria. The aim of this study was to analyze and to compare the presence of putative virulence factors codified in plasmid -katP, espP, subA, stcE- and adhesins involved in colonization of cattle -efa1, iha- in 255 native STEC strains isolated from different categories of cattle from different production systems. The most prevalent gene in all strains was espP, and the less prevalent was stcE. katP was highly detected in strains isolated from young and rearing calves (33.3%), while subA was predominant in those isolated from adults (71.21%). Strains from young calves showed the highest percentage of efa1 (72.46%), while iha showed a high distribution in strains from rearing calves and adults (87.04 and 98.48% respectively). It was observed that espP and iha were widely distributed throughout all strains, whereas katP, stcE, and efa1 were more associated with the presence of eae and subA with the eae-negative strains. A great proportion of eae-negative strains were isolated from adults -dairy and grazing farms- and from rearing calves -dairy and feedlot-, while mostly of the eae-positive strains were isolated from dairy young calves. Data exposed indicate a correlation between the category of the animal and the production systems with the presence or absence of several genes implicated in adherence and virulence of STEC.

Serotyping, virulence gene expression and phenotypic characterization of E. coli O157:H7 in colibacillosis affecting buffalo calves in Basra governorate

“…Constable had reported that the bacteria toxins exerts effect on the thermoregulatory center of the hypothalamus thereby altering the thermostatic level. The other clinical signs such as heart rate, respiratory rate, capillary refilling time, weakens, dehydration is similar to those observed and reported by Constable et al; Cundon et al; Caceres et al (9,22,23). These authors reported that the production of the enterotoxin results in net secretion of fluid and electrolytes from the systemic circulation into the lumen of the intestine, resulting in varying degrees of diarrhea, dehydration, electrolyte imbalances, acidemia, circulatory failure, shock, and death.…”

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“…Some factors that contribute to the presence and spread of STEC in a herd are the management practices, stress, diet, population density, geographic region and season [41]. Contact with feces of cattle, direct contact with the animals or their environment and consumption of contaminated beef, milk, dairy products, water, unpasteurized apple juices and vegetables are possible routes for STEC human exposure and disease [42]. So, measures to prevent direct contact with animal fecal material in the environment include the wearing of protective clothing, increased hand washing and targeted education of the population at risk regarding possible sources of STEC infection.…”

Botulinum Toxin Type A—A Modulator of Spinal Neuron–Glia Interactions under Neuropathic Pain Conditions

“…Obtained data suggest that BoNT/A, in addition to altering neuronal function, can also influence spinal microglial cells [ 38 , 39 ]; however, it is still unclear whether those BoNT/A actions are mediated in a direct or indirect manner. The latest in vitro research by Piotrowska et al 2017 [ 62 ] shed new light on the analgesic effect of BoNT/A and suggested a possible direct impact of this toxin on microglia in the CNS ( Figure 1 ).…”

“…The direct influence of BoNT/A on astroglia was unclear, since the study by Parpura et al (1995) [ 64 ] showed the expression of some of the SNARE protein complexes but not that of SNAP-25. The authors analyzed post-nuclear astroglial cell membrane extract, not the whole lysates as in Piotrowska et al 2017 [ 62 ]. The authors, using in vitro primary cell culture studies, have demonstrated that astroglial cells possess both mRNA and protein for the SNAREs SNAP-25 and SNAP-23 [ 62 ].…”

“…The authors analyzed post-nuclear astroglial cell membrane extract, not the whole lysates as in Piotrowska et al 2017 [ 62 ]. The authors, using in vitro primary cell culture studies, have demonstrated that astroglial cells possess both mRNA and protein for the SNAREs SNAP-25 and SNAP-23 [ 62 ]. These data correlate well with the study of Marinelli et al (2012) [ 61 ] showing that BoNT/A exerts analgesic effects on neuropathic pain through the cleavage of SNAP-25 in spinal astroglia.…”