scholarly journals Correction: Azinheiro et al. Multiplex Detection of Salmonella spp., E. coli O157 and L. monocytogenes by qPCR Melt Curve Analysis in Spiked Infant Formula. Microorganisms 2020, 8, 1359

2021 ◽  
Vol 9 (7) ◽  
pp. 1482
Author(s):  
Sarah Azinheiro ◽  
Joana Carvalho ◽  
Marta Prado ◽  
Alejandro Garrido-Maestu

The authors would like to make the following correction to the published paper [...]

2020 ◽  
Vol 8 (9) ◽  
pp. 1359
Author(s):  
Sarah Azinheiro ◽  
Joana Carvalho ◽  
Marta Prado ◽  
Alejandro Garrido-Maestu

Food poisoning continue to be a threat in the food industry showing a need to improve the detection of the pathogen responsible for the hospitalization cases and death. DNA-based techniques represent a real advantage and allow the detection of several targets at the same time, reducing cost and time of analysis. The development of new methodology using SYBR Green qPCR for the detection of L. monocytogenes, Salmonella spp. and E. coli O157 simultaneously was developed and a non-competitive internal amplification control (NC-IAC) was implemented to detect reaction inhibition. The formulation and supplementation of the enrichment medium was also optimized to allow the growth of all pathogens. The limit of detection (LoD) 95% obtained was <1 CFU/25 g for E. coli O157, and 2 CFU/25 g for Salmonella spp. and L. monocytogenes and regarding the multiplex detection a LoD 95% of 1.7 CFU/25 g was observed. The specificity, relative sensitivity and accuracy of full methodology were 100% and the use of the NC-IAC allowed the reliability of the results without interfering with the sensitivity of the methodology. The described study proved to obtain results comparable to those of probe-based qPCR, and more economically than classical high resolution melting qPCR, being both important aspects for its implementation in the food industry.


Micromachines ◽  
2021 ◽  
Vol 12 (8) ◽  
pp. 959
Author(s):  
Dammika P. Manage ◽  
Jana Lauzon ◽  
Linda M. Pilarski ◽  
Patrick M. Pilarski ◽  
Lynn M. McMullen

Detection sensitivity of cassette PCR was compared with a commercial BAX® PCR system for detection of eae and stx genes in Escherichia coli from 806 beef carcass swabs. Cassette PCR detects multiple genetic markers on multiple samples using PCR and melt curve analysis. Conventional PCR served as a gold standard. Overall, for positive and negative concordance, cassette PCR was 98.6% concordant with conventional PCR, and BAX PCR was 65.4% concordant. Of 806 beef carcass swabs, 339 by cassette PCR and 84 by BAX PCR harbored eae + stx+E. coli. For BAX PCR reactions, 84% of eae+ swabs, 79% of stx+ swabs, and 86% of eae + stx+ swabs were also detected by cassette PCR. For cassette PCR reactions, 457 swabs were eae+ with only 117 scored as eae+ using BAX PCR for 26% positive concordance. For stx primers, cassette PCR scored 480 samples as stx+ but only 215 samples were stx+ by BAX PCR, giving 45% positive concordance. Importantly, cassette PCR scored 339 swabs as harboring eae + stx+ E. coli, but BAX PCR detected only 71 positives giving only 21% positive concordance, with many false negatives. Cassette PCR is a highly sensitive method for detection of STEC genes in E. coli found in carcass swabs.


2018 ◽  
Vol 69 (5) ◽  
pp. 1240-1243
Author(s):  
Manuela Arbune ◽  
Mioara Decusara ◽  
Luana Andreea Macovei ◽  
Aurelia Romila ◽  
Alina Viorica Iancu ◽  
...  

The aim of the present study was to characterize the antibiotic resistance profile of enterobacteriaceae strains isolated in Infectious Diseases Hospital Galati, Romania, during 2016, in order to guide the local antibiotic stewardship strategy. There are 597 biological samples with positive cultures for enterobacteriaceae, related to invasive and non-invasive infections. The main bacterial genus were E. coli 62%, Klebsiella spp 15%, Proteus spp 11% and Salmonella spp 6%. Over a half of isolated strains have one or more antibiotic resistance. The resistance level depends on bacterial genus, with highest level found among the rare isolates: Enterobacter spp, Citrobacter spp, Morganella spp and Serratia spp. The rate of MDR was 17.,6% for E. coli, 40.9% for Klebsiella spp and 50.7% for Proteus spp. while the rate of strains producing Extended Spectrum of Beta Lactamase are 7.2% for E. coli, 28.4% for Klebsiella spp and 12.3% for Proteus spp. The carbapenem resistant strains were found in 1.1% cases.


2021 ◽  
Vol 193 (8) ◽  
Author(s):  
Desmond Tichaona Mugadza ◽  
Sibusisiwe Isabel Nduku ◽  
Edlyn Gweme ◽  
Sherpherd Manhokwe ◽  
Patience Marume ◽  
...  

Foods ◽  
2018 ◽  
Vol 7 (12) ◽  
pp. 206 ◽  
Author(s):  
Juliane Dao ◽  
Kathrin Stenchly ◽  
Oumar Traoré ◽  
Philip Amoah ◽  
Andreas Buerkert

Vegetable production in urban gardens of Ouagadougou contributes to food security, but water for irrigation is often of low quality. This is particularly acute if irrigation water is taken from wastewater polluted channels. This study aimed at (i) verifying to what degree irrigation water quality is correlated with contamination of lettuce with Escherichia coli, total coliforms, and Salmonella spp., and (ii) assessing effects of post-harvest handling on pathogen development during the trade chain. We tested pathogen removal efficiency on lettuce by applying post-harvest washing. Irrigation water of production areas in Ouagadougou (n = 10) showed a mean E. coli load of 2.1 × 105 CFU 100 mL−1. In 60% of the cases, irrigation water did not meet the standards of the World Health Organization (WHO) for safe irrigation water, and in 30% of the cases, irrigation water was contaminated with Salmonella spp. Loads of total coliforms on lettuce leaves ranged from 2.9 × 103 CFU g−1 to 1.3 × 106 CFU g−1, while E. coli averaged 1.1 × 102 CFU g−1. Results on post-harvest handling revealed that microbial loads increased along the trade chain. Overall, half of all lettuce samples (n = 60) were tested positively for Salmonella spp. The experiment showed that appropriate post-harvest handling could prevent the increase of total coliforms.


2017 ◽  
Vol 38 (1) ◽  
pp. 175 ◽  
Author(s):  
Natalia Harumi Niguma ◽  
Jacinta Sanchez Pelayo ◽  
Tereza Cristina Rocha Moreira de Oliveira

The aims of this study were to evaluate the contamination of lettuce (Lactuca sativa), produced in Londrina, Paraná (PR), with total coliform, coliform at 45 °C, E. coli, and Salmonella spp.; and to determine the E. coli contamination of irrigation water used at the farms studied. Four farms were evaluated, of which three produced lettuce using a conventional system and one using an organic system. An evaluation of the production practices of the farms was also carried out. A total of 111 samples were analyzed, 71 lettuce samples from the conventional system and 40 samples from the organic system. A total of eight irrigation water samples were collected for analysis. Coliform at 45 °C counts above the limit tolerated by Brazilian legislation were observed in 2.8% (2/71) of conventionally grown lettuce samples, and Salmonella spp. was isolated in 1.4% (1/71) of those samples. In the organic lettuce samples, 12.5% (5/40) had coliform at 45 °C counts above the limit tolerated and Salmonella spp. was not detected. Irrigation water samples from three farms were unsatisfactory, with counts higher than 102MPN of E. coli per 100mL. The results of this study demonstrate that most conventionally grown lettuce samples show good sanitary conditions in production, and that lettuce contamination is not related to contamination found in irrigation water samples. The results also showed that the organic production practices required by Brazilian certification agencies should be applied to ensure that contamination of produced lettuce remains controlled.


2014 ◽  
Vol 81 (2) ◽  
pp. 180-185 ◽  
Author(s):  
Lilian Gregory ◽  
Rodolfo Santos Rossi ◽  
João Padilha Gandara Mendes ◽  
Natalie Neuwirt ◽  
Eduardo Carvalho Marques ◽  
...  

A população de bubalinos estimada no Brasil é de aproximadamente 3 milhões de animais, encontrando-se distribuídos em todos os Estados brasileiros, com crescimento médio anual de 12%. Apesar disso, os trabalhos realizados buscando os avanços na bubalinocultura são escassos. Em função da complexidade etiológica da diarreia em bubalinos e da falta de informações recentes nesta área, o presente estudo teve como objetivo avaliar a ocorrência dos principais agentes bacterianos e parasitários envolvidos na diarreia de bezerros búfalos lactentes, de explorações leiteiras semi-intensivas e intensivas em regiões dos estados de São Paulo e Paraná. De março de 2010 a junho de 2011, foram colhidas 53 amostras para exame coproparasitológico e 46 amostras para o exame bacteriológico de animais com quadro de diarreia nos municípios paulistas de São João da Boa Vista, Dourado, Pirassununga, Registro, Pariquera Açu, Pilar do Sul e uma propriedade no estado do Paraná, município de Santana do Itararé. No exame parasitológico, 45,28% (24) foram positivos para Eimeria spp., 26,42% (14) para Strongyloidea e 1,88 (1) para Toxocara vitulorum. No exame bacteriológico, 97,83%, (45) das amostras foram positivas para E. coli, contudo, somente duas foram consideradas patogênicas (E. coli STEC). Em uma amostra (2,17%) isolou-se Klebsiella pneumoniae; já a presença de Salmonella spp. não foi constatada. Para o presente estudo, a presença de endoparasitas foi bastante relevante, principalmente os casos Eimeria spp., sendo a higiene das instalações e falhas de manejo fatores importantes na ocorrência de diarreia em bezerros búfalos no estado de São Paulo.


2003 ◽  
Vol 66 (11) ◽  
pp. 2010-2016 ◽  
Author(s):  
SHIGENOBU KOSEKI ◽  
KYOICHIRO YOSHIDA ◽  
YOSHINORI KAMITANI ◽  
KAZUHIKO ITOH

The influence of bacterial inoculation methods on the efficacy of sanitizers against pathogens was examined. Dip and spot inoculation methods were employed in this study to evaluate the effectiveness of acidic electrolyzed water (AcEW) and chlorinated water (200 ppm free available chlorine) against Escherichia coli O157:H7 and Salmonella spp. Ten pieces of lettuce leaf (5 by 5 cm) were inoculated by each method then immersed in 1.5 liters of AcEW, chlorinated water, or sterile distilled water for 1 min with agitation (150 rpm) at room temperature. The outer (abaxial) and inner (adaxial) surfaces of the lettuce leaf were distinguished in the spot inoculation. Initial inoculated pathogen population was in the range 7.3 to 7.8 log CFU/g. Treatment with AcEW and chlorinated water resulted in a 1 log CFU/g or less reduction of E. coli O157:H7 and Salmonella populations inoculated with the dip method. Spot inoculation of the inner surface of the lettuce leaf with AcEW and chlorinated water reduced the number of E. coli O157:H7 and Salmonella by approximately 2.7 and 2.5 log CFU/g, respectively. Spot inoculation of the outer surface of the lettuce leaf with both sanitizers resulted in approximately 4.6 and 4.4 log CFU/g reductions of E. coli O157:H7 and Salmonella, respectively. The influence of inoculation population size was also examined. Each sanitizer could not completely eliminate the pathogens when E. coli O157:H7 and Salmonella cells inoculated on the lettuce were of low population size (103 to 104 CFU/g), regardless of the inoculation technique.


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