Comparison of Agar Media for Detection and Quantification of Shiga Toxin-Producing Escherichia coli in Cattle Feces.
نویسندگان
چکیده
The isolation and quantification of non-O157 Shiga toxin-producing Escherichia coli (STEC) from cattle feces are challenging. The primary objective of this study was to evaluate the performance of selected agar media in an attempt to identify an optimal medium for the detection and quantification of non-O157 STEC in cattle feces. Comparison studies were performed using CHROMagar STEC, Possé differential agar (Possé), Possé modified by the reduction or addition of antimicrobials, STEC heart infusion washed blood agar with mitomycin C (SHIBAM), and SHIBAM modified by the addition of antimicrobials. Fourteen STEC strains, two each belonging to serogroups O26, O45, O103, O111, O121, O145, and O157, were used to test detection in inoculated fecal suspensions at concentrations of 10(2) or 10(3) CFU/g. One STEC strain from each of these seven serogroups was used to estimate the concentration of recovered STEC in feces inoculated at 10(3), 10(4), or 10(5) CFU/g. Significantly more suspensions (P < 0.05) were positive for STEC when plated on Possé containing reduced concentrations of novobiocin and potassium tellurite compared with SHIBAM, but not SHIBAM modified by containing these same antimicrobials at the same concentrations. Numerically, more suspensions were positive for STEC by using this same form of modified Possé compared with Possé, but this difference was not statistically significant. More suspensions were positive for STEC cultured on CHROMagar STEC compared with those on Possé (P < 0.05) and on modified Possé (P = 0.05). Most inoculated fecal suspensions below 10(4) CFU/g of feces were underestimated or not quantifiable for the concentration of STEC by using CHROMagar STEC or modified Possé. These results suggest that CHROMagar STEC performs better than Possé or SHIBAM for detection of STEC in bovine feces, but adjustments in the concentrations of novobiocin and potassium tellurite in the latter two media result in significant improvements in their performance.
منابع مشابه
Prevalence and molecular characterization of verotoxin-producing Escherichia coli O157:H7 in cattle and sheep in Shiraz-Iran
Shiga toxin producing Escherichia coli have been associated with HUS, HC and TTP in human. We found recto-anal mucosal sample in sheep as well in cattle is the main site for E. coli O157 localization. 1246 E. coli isolates from 872 both healthy and diarrheic animals were analyzed, by screening for the presence of Shiga toxin-producing (VT 1 and VT 2) and intimin (eae) genes used Multiplex PCR. ...
متن کاملChromogenic agar medium for detection and isolation of Escherichia coli serogroups O26, O45, O103, O111, O121, and O145 from fresh beef and cattle feces.
Non-O157 Shiga toxin-producing Escherichia coli (STEC) strains are clinically important foodborne pathogens. Unlike E. coli O157:H7, these foodborne pathogens have no unique biochemical characteristics to readily distinguish them from other E. coli strains growing on plating media. In this study, a chromogenic agar medium was developed in order to differentiate among non-O157 STEC strains of s...
متن کاملDetection of Shiga Toxin-Producing Strains of Escherichia coli (O157:H7) isolated from specimens of urinary and stool by Multiplex-PCR method
Background: Infection of shiga toxin-producing Strains of Escherichia coli has some other dangerous and deadly effects such as hemolytic uremic syndrome (HUS) in addition to diarrhea. Its diagnosis is difficult and there is no information on It's incidence in Iran. The goal of this study is to evaluate and detect shiga toxinproducing strains of E. coli isolated from urinary and stool specimens ...
متن کاملDetection of Shiga toxin-producing Escherichia coli (STEC) in faeces of healthy calves in Mashhad, Iran
The aim of this study was to identify virulent Shiga toxin-producing Escherichia coli (STEC) strains isolated from faecal samples of 100 clinically healthy calves. In the present study, a total of 100 Escherichia coli (E. coli) isolates from clinically healthy calves belonging to 6 different farms located in Khorasan Razavi province, Iran, were examined for presence of virulence genes character...
متن کاملPrevalence of Multidrug Resistant Shiga Toxin-Producing Escherichia coli in Cattle Meat and Its Contact Surfaces
Background: Shiga toxin-producing Escherichia coli (STEC) are group of E. coli causing bloody diarrhea. The goal of this survey was to determine the prevalence of multidrug resistant shiga toxin-producing E. coli in cattle meat and its contact surfaces. Methods: Swab samples (n=120) were randomly collected from meat and contact surface of butchery shops in Sharkia province, Egypt. Prevalence o...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Journal of food protection
دوره 79 6 شماره
صفحات -
تاریخ انتشار 2016