Characterization of enterotoxigenic E. coli (ETEC), Shiga-toxin producing E. coli (STEC) and necrotoxigenic E. coli (NTEC) isolated from diarrhoeic Mediterranean water buffalo calves (Bubalus bubalis)

Borriello, Giorgia; Lucibelli, Maria Gabriella; Carlo, Esterina De; Auriemma, Clementina; Cozza, D.; Ascione, G.; Scognamiglio, Francesca; Iovane, G.; Galiero, Giorgio

doi:10.1016/j.rvsc.2011.05.009

Cited by 27 publications

(30 citation statements)

References 33 publications

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“…E. coli and C. perfringens were isolated according to the protocol reported by Quinn et al [2]. E. coli hemolytic activity was evaluated by growing colonies on blood agar base, while virulence factors (lt-heat-labile toxin, st-heatstable toxin, stx1-Shiga toxin 1, stx2-Shiga-toxin 2, eaeintimin, cnf-cytotoxic necrotizing factor, and cdt-cytolethal distending toxin) were detected by molecular assays, as previously reported [26][27][28].…”

Section: Bacterial Strains and Diagnostic Methodsmentioning

confidence: 99%

Diversity of Salmonella spp. serovars isolated from the intestines of water buffalo calves with gastroenteritis

et al. 2012

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BackgroundSalmonellosis in water buffalo (Bubalus bubalis) calves is a widespread disease characterized by severe gastrointestinal lesions, profuse diarrhea and severe dehydration, occasionally exhibiting a systemic course. Several Salmonella serovars seem to be able to infect water buffalo, but Salmonella isolates collected from this animal species have been poorly characterized. In the present study, the prevalence of Salmonella spp. in water buffalo calves affected by lethal gastroenteritis was assessed, and a polyphasic characterization of isolated strains of S. Typhimurium was performed.ResultsThe microbiological analysis of the intestinal contents obtained from 248 water buffalo calves affected by lethal gastroenteritis exhibited a significant prevalence of Salmonella spp. (25%), characterized by different serovars, most frequently Typhimurium (21%), Muenster (11%), and Give (11%). The 13 S. Typhimurium isolates were all associated with enterocolitis characterized by severe damage of the intestine, and only sporadically isolated with another possible causative agent responsible for gastroenteritis, such as Cryptosporidium spp., Rotavirus or Clostridium perfringens. Other Salmonella isolates were mostly isolated from minor intestinal lesions, and often (78% of cases) isolated with other microorganisms, mainly toxinogenic Escherichia coli (35%), Cryptosporidium spp. (20%) and Rotavirus (10%). The S. Typhimurium strains were characterized by phage typing and further genotyped by polymerase chain reaction (PCR) detection of 24 virulence genes. The isolates exhibited nine different phage types and 10 different genetic profiles. Three monophasic S. Typhimurium (B:4,12:i:-) isolates were also found and characterized, displaying three different phage types and three different virulotypes. The molecular characterization was extended to the 7 S. Muenster and 7 S. Give isolates collected, indicating the existence of different virulotypes also within these serovars. Three representative strains of S. Typhimurium were tested in vivo in a mouse model of mixed infection. The most pathogenic strain was characterized by a high number of virulence factors and the presence of the locus agfA, coding for a thin aggregative fimbria.ConclusionsThese results provide evidence that Salmonella is frequently associated with gastroenteritis in water buffalo calves, particularly S. Typhimurium. Moreover, the variety in the number and distribution of different virulence markers among the collected S. Typhimurium strains suggests that within this serovar there are different pathotypes potentially responsible for different clinical syndromes.

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Section: Bacterial Strains and Diagnostic Methodsmentioning

confidence: 99%

Diversity of Salmonella spp. serovars isolated from the intestines of water buffalo calves with gastroenteritis

et al. 2012

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“…Diarrhea is an important health concern in young animals, and frequently E. coli pathovars such as enterotoxigenic E. coli (ETEC), Shiga-toxin producing E. coli (STEC), enterohemorrhagic E. coli (EHEC), and entero-pathogenic E. coli (EPEC), are associated with its etiology (CROXEN & FINLAY 2010). Water buffalo calves are susceptible to all E. coli pathovars that cause diarrhea in bovine calves, including necrotoxigenic E. coli (NTEC) (BORRIELLO et al, 2012).…”

Section: Introductionmentioning

confidence: 99%

“…There are a few studies involving E. coli pathovar infections in buffalo calves worldwide (OLIVEIRA et al, 2007;BORRIELLO et al, 2012;MAHANTI et al, 2013;BERALDO et al, 2014). Most previous studies focused on STEC infections, and phylogenetic classification was not performed.…”

Section: Introductionmentioning

confidence: 99%

Virulence factors and phylotyping of Escherichia coli isolated from non-diarrheic and diarrheic water buffalo calves

et al. 2019

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This study aimed to determine the virulence factors, phylogenetic groups, and the relationships between pathovars and phylogenetic groups of E. coli strains isolated from feces of buffalo calves. A total of 217 E. coli strains were obtained from feces after culture and were screened by PCR for detection of virulence factors EAST-1, enterohemolysin, Saa, CNF2, F41, F5, STa, intimin, Stx1 and Stx2. One hundred and thirty-four isolates were positive for one or more virulence factors: eighty-four from diarrheic animals, and fifty from non-diarrheic calves. The pathovars of E. coli identified in diarrheic feces were ETEC (F5+) (2/84), NTEC (16/84), STEC (20/84), EPEC (3/84), EHEC (3/84), and EAEC (EAST-1+) (33/84). Pathovars identified in non-diarrheic animals were NTEC (21/50), STEC (17/50), EHEC (1/50) and EAEC (7/50). E. coli strains positive for EAST-1 (P=0.008) and phylogroup C (P = 0.05) were associated with the presence of diarrhea. Phylogenetic analysis showed that 58.95% of the isolates belonged to phylogroup B1, followed by E (9.70%), B2 (5.90%), C (5.90%), D (5.22%), A (2.24%), and F (1.50%). Phylogroup B1 predominated in pathogenic E. coli isolated from water buffalo, and phylogroup C constituted an enteropathogenic E. coli for water buffalo calves.

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“…The carriage rates observed in the period from 2002 to 2003 were 32.3 and 14.5% of the herds and animals sampled respectively, and serotype O157:H7 isolates were de-643 tected (Galiero et al, 2005). Similarly, a study carried out from 2006 to 2009 showed that 6.8% of E. coli isolates detected in water buffalo calves with diarrheic syndrome were characterized as enterohemorrhagic E. coli (EHEC), possessing stx1, eae, and HlyA genes (Borriello et al, 2012). In 2005, 2 STEC clusters, each with 3 cases of hemolytic uremic syndrome due to serotype O26 were observed in June and September (Scavia et al, 2005).…”

Section: Introductionmentioning

confidence: 98%

“…Microbial contamination of raw milk by Shiga toxinproducing Escherichia coli (STEC) has been reported in several areas, including buffalo herds in southern Italy (Galiero et al, 2005;Borriello et al, 2012). The carriage rates observed in the period from 2002 to 2003 were 32.3 and 14.5% of the herds and animals sampled respectively, and serotype O157:H7 isolates were de-643 tected (Galiero et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

Thermal inactivation kinetics of Shiga toxin-producing Escherichia coli in buffalo Mozzarella curd

Trevisani

Mancusi

Valero

2014

Journal of Dairy Science

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The use of raw milk in the processing of buffalo Mozzarella cheese is permitted, but the heat treatment used for stretching the curd must ensure that the final product does not contain pathogens such as Shiga toxin-producing Escherichia coli (STEC) that may be present on buffalo dairy farms. This study carried out challenge tests at temperatures between 68 °C and 80 °C for 2 to 10 min to simulate curd temperatures during the stretching phase. Curd samples were inoculated with 2 STEC strains (serotypes O157 and O26), and their inactivation rates were assessed in the different challenge tests. The curd samples were digested with papain to ensure a homogeneous dispersion of bacteria. The STEC cells were counted after inoculation (range 7.1-8.7 log cfu/g) and after heat treatments using the most probable number (MPN) technique. A plot of log MPN/g versus time was created for each separate experiment. The log linear model with tail was used to provide a reasonable fit to observed data. Maximum inactivation rate (k(max), min(-1)), residual population (log MPN/g), decimal reduction time (min), and time for a 4D (4-log10) reduction (min) were estimated at each temperature tested. A 4D reduction of the O26 STEC strain was achieved when curd was heated at 68 °C for 2.6 to 6.3 min or at 80 °C for 2.1 to 2.3 min. Greater resistance was observed for the O157 strain at 68 °C because k(max) was 1.48 min(-1). The model estimates can support cheesemakers in defining appropriate process criteria needed to control possible STEC contamination in raw milk intended for the production of Mozzarella.

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Characterization of enterotoxigenic E. coli (ETEC), Shiga-toxin producing E. coli (STEC) and necrotoxigenic E. coli (NTEC) isolated from diarrhoeic Mediterranean water buffalo calves (Bubalus bubalis)

Cited by 27 publications

References 33 publications

Diversity of Salmonella spp. serovars isolated from the intestines of water buffalo calves with gastroenteritis

Diversity of Salmonella spp. serovars isolated from the intestines of water buffalo calves with gastroenteritis

Virulence factors and phylotyping of Escherichia coli isolated from non-diarrheic and diarrheic water buffalo calves

Thermal inactivation kinetics of Shiga toxin-producing Escherichia coli in buffalo Mozzarella curd

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