Genes Encoding the Virulence and the Antimicrobial Resistance in Enterotoxigenic and Shiga-Toxigenic E. coli Isolated from Diarrheic Calves.

Calf diarrhea is one of the considerable infectious diseases in calves, which results in tremendous economic losses globally. To determine the prevalence of Shiga-toxigenic E. coli (STEC) and Enterotoxigenic E. coli (ETEC) incriminated in calf diarrhea, with special reference to Shiga- toxins genes (stx1 and stx2) and enterotoxins genes (lt and sta) that govern their pathogenesis, as well as the virulence genes; eaeA (intimin) and f41(fimbrial adhesion), and the screening of their antibiogram and antimicrobial resistance genes; aadB, sul1, and bla-TEM, a total of 274 fecal samples were collected (April 2018-Feb 2019) from diarrheic calves at different farms in El-Sharqia Governorate, Egypt. The bacteriological examination revealed that the prevalence of E. coli in diarrheic calves was 28.8%. The serotyping of the isolated E. coli revealed 7 serogroups; O26, O128, O111, O125, O45, O119 and O91. Furthermore, the Congo red binding test was carried out, where 89.8% of the examined strains (n = 71) were positive. The antibiogram of the isolated strains was investigated; the majority of E. coli serotypes exhibit multidrug resistance (MDR) to four antimicrobial agents; neomycin, gentamycin, streptomycin, and amikacin. Polymerase chain reaction (PCR) was used to detect the prevalence of the virulence genes; stx1, stx2 lt, sta, f41 and eaeA, as well as the antibiotic resistance genes; aadB, sul1, and bla-TEM. The prevalence of STEC was 20.2% (n = 16), while the prevalence of ETEC was 30.4% (n = 24). Briefly, the Shiga toxins genes; stx1 and stx2, are the most prevalent virulence genes associated with STEC, which are responsible for the pathogenesis of the disease and helped by the intimin gene (eaeA). In addition, the lt gene is the most prevalent enterotoxin gene accompanied by the ETEC strains, either alone or in combination with sta and/or f41 genes. The majority of pathogenic E. coli incriminated in calf diarrhea possesses the aadB resistance gene, followed by the sul1 gene. Enrofloxacin, florfenicol, amoxicillin-clavulanic acid, and ampicillin-sulbactam, are the most effective antimicrobial agents against the isolated STEC and ETEC strains.

Cutaneous mononuclear cells and eosinophils are significantly increased after warm water challenge in pruritic areas of polycythemia vera.

BACKGROUND: Increased cutaneous cells following warm water challenge in pruritus-related polycythemia vera (PV) have been reported, but their nature and magnitude are not known. METHODS: Qualitative and quantitative assessments (digital image analysis) of the cutaneous mononuclear cells, eosinophils and mast cells were carried out in PV patients and healthy controls (n = 10 each) following exposures to water at room temperature and warm water. RESULTS: Infiltration of the spongiotic epidermis and dermis by mononuclear cells and eosinophils together with edema and vasodilatation of upper dermis following warm water contact was clearly observed only in PV patients. In contrast to controls, significant increase in numbers of mononuclear cells and eosinophils in comparison with exposure to water at room temperature at the dermal-epidermal junction (p < 0.01), papillary dermis (p < 0.01) and perivascular area (p < 0.05) was found. Obvious mast cell degranulation was seen in PV sections after warm water contact, but no significant increase of their numbers was observed whether among PV patients or healthy controls (p > 0.05). However, the numbers of papillary dermal mast cells in specimens obtained from PV patients following room temperature water exposure were significantly more than those of healthy controls (p < 0.05). CONCLUSIONS: PV represents an invisible dermatosis in which the infiltrating mononuclear cells and eosinophils may have a role in warm water-induced pruritus.