Full Sequence and Comparative Analysis of the Plasmid pAPEC-1 of Avian Pathogenic E. coli χ7122 (O78∶K80∶H9)

(APEC), are very diverse. They cause a complex of diseases in Human, animals, and birds. Even though large plasmids are often associated with the virulence of ExPEC, their characterization is still in its infancy., are also present in the sequence of pAPEC-1. The comparison of the pAPEC-1 sequence with the two available plasmid sequences reveals more gene loss and reorganization than previously appreciated. The presence of pAPEC-1-associated genes is assessed in human ExPEC by PCR. Many patterns of association between genes are found.The pathotype typical of pAPEC-1 was present in some human strains, which indicates a horizontal transfer between strains and the zoonotic risk of APEC strains. ColV plasmids could have common virulence genes that could be acquired by transposition, without sharing genes of plasmid function

Prevalence and antimicrobial resistance of salmonella enterica shed from range and feedlot cattle from post-weaning to slaughter

The objectives of this study were to (1) estimate the prevalence of Salmonella in beef cows and steers at postweaning, finishing and slaughter, and (2) determine antimicrobial resistance of isolates, and (3) assess the association between resistance and presence of class 1 integrons. Fecal samples were collected from 48 cows and 48 steers at multiple sampling periods, and mid-line sponge samples collected from steer hides before slaughter. Bacteriological culture, antimicrobial resistance tests, and polymerase chain reaction testing were performed. Salmonella prevalence varied from 8% (3/38) to 92% (35/38] in cows and from 28% (13/47) to 100% (24/24) in steers, with higher estimates at postweaning than at finishing and slaughter. Of the 200 isolates recovered, the majority (56%) were resistant to 2 or more antimicrobials. Class 1 integrons were detected in 98 isolates, of which 88 (90%) carried the conserved sequence for aadA resistance gene encoding for streptomycin/spectinomycin resistance. Study findings revealed that most steers shed Salmonella at postweaning, indicating widespread exposure either before or after weaning. The recovery of multidrug resistant isolates and presence of class 1 integrons carrying the aadA resistance gene further underscores the dilemma and public health significance associated with veterinary use of antibiotics such as streptomycin in beef cattle. Copyright © 2015, International Association for Food Protection 6200 Aurora Ave., Suite 200W, Des Moines, IA 50322-2864

Isolation and characterization of shiga toxin-producing escherichia coli serogroups O26, O45, O103, O111, O113, O121, O145, and O157 shed from range and feedlot cattle from postweaning to slaughter

Cattle are the main reservoirs for Shiga toxin-producing Escherichia coli (STEC) strains. E. coli O26, O45, O103, O111, O121, O145, and O157 are among the STEC serogroups that cause severe foodborne illness and have been declared as adulterants by the U.S. Department of Agriculture, Food Safety and Inspection Service. The objectives of this study were (i) to estimate the prevalence of non-O157 STEC and E. coli O157 in naturally infected beef cows and in steer calves at postweaning, during finishing, and at slaughter and (ii) to test non-O157 STEC isolates for the presence of virulence genes stx1, stx2, eaeA, and ehlyA. Samples were collected from study animals during multiple sampling periods and included fecal grabs, rectal swabs, and midline sponge samples. Laboratory culture, PCR, and multiplex PCR were performed to recover and identify E. coli and the virulence genes. The prevalence of non-O157 STEC (serogroups O26, O45, O103, O111, O121, O113, and O145) fecal shedding ranged from 8% (4 of 48 samples) to 39% (15 of 38 samples) in cows and 2% (1 of 47 samples) to 38% (9 of 24 samples) in steer calves. The prevalence of E. coli O157 fecal shedding ranged from 0% (0 of 38 samples) to 52% (25 of 48 samples) in cows and 2% (1 of 47 samples) to 31% (15 of 48 samples) in steer calves. In steer calves, the prevalence of non-O157 STEC and E. coli O157 was highest at postweaning, at 16% (15 of 96 samples) and 23% (22 of 96 samples), respectively. Among the 208 non- O157 STEC isolates, 79% (164 isolates) had stx1, 79% (165 isolates) had stx2, and 58% (121 isolates) had both stx1 and stx2 genes. The percentage of non-O157 STEC isolates encoding the eaeA gene was low; of the 165 isolates tested, 8 (5%) were positive for eaeA and 135 (82%) were positive for ehlyA. Findings from this study provide further evidence of non-O157 STEC shedding in beef cows and steer calves particularly at the stage of postweaning and before entry into the feedlot

Prevalence of Escherichia coli and Salmonella in Runoff of Two Cattle Feedlots in North Dakota

Livestock waste is used extensively as manure in crop farming. Improperly managed manure can contaminate foods such as raw produce and can serve as a major source of zoonotic foodborne pathogens such as Escherichia coli and Salmonella. The objective of this study was to detect and estimate the prevalence of E. Coli (0157 and non-0157] serotypes and Salmonella species in runoff samples collected from two cattle feedlots [A and B) in North Dakota. Runoff samples were collected using automatic samplers (ISCO 6712) and processed by following standard culture and confirmatory methods for the isolation of E. Coli and Salmonella. Of 136 samples collected from feedlots A and B, 106 (78%) tested positive for at least one of the E. Coli serotypes (026, 045, 0103, 0111, 0113, 0121, 0145 and 0157), and 54 (40%) tested positive for Salmonella. One to seven E. Coli serotypes were detected in each of the positive runoff samples, and a total of 237 E. Coli serotypes were detected in the 106 positive runoff samples. Of the 237 serotypes, the most frequent was 045 (22%), followed by 0103 (19%), 0157 (18%), 0121 (15%), 026 (9%), 0111 (5%), 0113 (5%), and 0145 (5%). The number of serotypes recovered from feedlot A (169/237) was higher (P< 0.001) than the number recovered from B (68/237). These data provide evidence of the presence of E. Coli serotypes and Salmonella in feedlot runoff, underscoring the need for pretreatment of feedlot runoff before it is disposed into the environment or used as fertilizer. Copyright 2016, International Association for Food Protection

A far‑field radio‑frequency experimental exposure system with unrestrained mice

Radio-frequency (RF) energy is nearly everywhere, it is used in cell phones, wire-less internet and many other sources. These RF energy levels used by common devices are below the threshold level which does not produce heating of cells in living tissues. However, this low-level exposure of RF energy has still raised concerns over its possible effects on human health, specifically, genetic alterations. Researchers have investigated if RF energy can induce changes in biological function (Gherardini 2014; Kundi 2009; Polk and Postow 1995; Vanderstaeten and Verschaeve 2008). The methods used to investigate RF energy effects have varied widely depending on study. This variation in procedures has led to a lack of reproducibility, and because of that, inconclusive results (Gherardini 2014; Vanderstaeten and Verschaeve 2008). The goal of this paper is to describe a new experimental exposure system to explore the effects of far-field RF energy on biological function in unrestrained murine models, in vivo. Paffi et al. (2013) performed an extensive review of exposure systems. Many of these used a horn antenna to deliver RF energy, but lack long term continuous exposure for free moving murine models. Other studies including Kesari et al. (2010) and Wasoonta

Resistência antimicrobiana e perfil plasmidial de Escherichia coli isolada de frangos de corte e poedeiras comerciais no Estado de Pernambuco

Embora existam linhagens de Escherichia coli não patogênicas para aves, muitas outras possuem a capacidade de causar sérios danos à saúde das mesmas, sendo capazes de ocasionar diferentes tipos de processos infecciosos. As linhagens patogênicas são denominadas Avian Pathogenic Escherichia coli (APEC), possuindo genes relacionados ao processo de patogênese em epissomos (plasmídios) ou no cromossomo. A presença de plasmídios, contendo genes de resistência a antibióticos em linhagens aviárias, patogênicas ou não, indicam a possibilidade de transferência gênica lateral entre diferentes tipos de linhagens facilitando também a transferência de genes de patogenicidade ou virulência. Objetivou-se com este estudo avaliar o perfil de sensibilidade a antibióticos (13) de diferentes amostras (35) de E. coli isoladas de aves comerciais do Estado de Pernambuco apresentando, ou não, sinais clínicos de processos infecciosos e correlacionar esta resistência com a presença de plasmídios. Os testes utilizados demonstraram que 94,28% dos isolados foram resistentes a três ou mais antibióticos, com a lincomicina apresentando o maior percentual de resistência (100%). Na Concentração Inibitória Mínima (CIM) observou-se multirresistência a vários antimicrobianos. A presença de plasmídios foi detecada em 80,0% (28/35) dos isolados, com 16 isolados apresentando plasmídios com peso molecular aproximado de 88 MDa. Também foi verificada a presença de linhagens apresentando plasmídios de vários tamanhos. Concluiu-se que isolados de E. coli resistentes a antimicrobianos utilizados na avicultura estão presentes no Estado de Pernambuco, tanto em frangos de corte quanto em poedeiras comerciais. A presença de plasmídios detectados na maioria dos isolados pode estar associada à resistência aos antimicrobianos e sugere a presença de possíveis genes relacionados à patogenicidade. Monitorar a resistência a antibióticos em bactérias isoladas de animais torna-se um fator determinante para eleição e êxito do tratamento, bem como a possibilidade de eliminação daquelas que possuem plasmídios para se evitar a transferência de genes relacionados à patogenicidade