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Article

Kaotar Nayme, Abouddihaj Barguigua, Brahim Bouchrif, Idrissa Diawara, Fatima El Otmani, Naima Elmdaghri, Khalid Zerouali and Mohammed Timinouni

The purpose of this paper is to assess the occurrence of the extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamase genes in 144 Escherichia coli isolates recovered…

Abstract

Purpose

The purpose of this paper is to assess the occurrence of the extended-spectrum β-lactamases (ESBLs) and AmpC β-lactamase genes in 144 Escherichia coli isolates recovered from 160 vegetable salad samples.

Design/methodology/approach

Among the 144 E. coli isolates recovered from 160 vegetable salads, 17 (12 percent) ceftazidime-resistant isolates were screened for ESBL production with the double disk-diffusion test. The ESBL-producing isolates were characterized for antimicrobial resistance, the presence of virulence genes and plasmid-mediated quinolone resistance (PMQR) determinants. The isolates were also subjected to phylogenetic group typing. The existence of plasmid AmpC genes and mutations in the regulatory region of the chromosomal AmpC gene was assessed using polymerase chain reaction (PCR) and sequencing. All β-lactamase isolates were further characterized by pulsed-field gel electrophoresis to determine the genetic relatedness.

Findings

Overall, 17 (12 percent) of the 144 E. coli isolates studied were ceftazidime resistant. Among the 17 isolates, 13 (77 percent) were multidrug resistant and four (23.5 percent) were ESBL producers. The bla CTX-M14 was the only gene detected. Of the 12 AmpC-producing isolates, three (18 percent) harbored plasmid-encoded AmpC and sequencing analysis of the chromosomal AmpC genes revealed mutations in the promoter/attenuator region. PMQR determinants were detected in 9 (52 percent) isolates. A was the most prevalent phylogenetic group (56 percent), followed by groups B1 (31 percent), D (6 percent), and B2 (6 percent). PCR showed that six (50 percent) ESBL/AmpC-producing E. coli isolates carried one and/or two virulence genes. Pulsed-field gel electrophoresis showed no epidemiological relationship between these isolates.

Originality/value

This study places vegetable salads within the spectrum of ecological niches that may be vehicles for antibiotic-resistant bacteria/genes with clinical interest and these findings are worthy of attention as their spread to humans by ingestion cannot be dismissed.

Details

British Food Journal, vol. 119 no. 7
Type: Research Article
ISSN: 0007-070X

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Article

Evelyne Toe, Adjéhi Dadié, Etienne Dako, Guillaume Loukou, Marcelin Koffi Dje and Y.C. Blé

Vegetable salads, despite their recognized health benefits, are an increasingly common cause of foodborne illness worldwide. The purpose of this paper is to determine the…

Abstract

Purpose

Vegetable salads, despite their recognized health benefits, are an increasingly common cause of foodborne illness worldwide. The purpose of this paper is to determine the prevalence of E. coli with virulence genes in ready-to-eat raw mixed vegetable salads sold in collective catering in Abidjan.

Design/methodology/approach

A total of 436 strains of E. coli were isolated from 306 ready-to-eat raw mixed vegetables salads and then identified biochemically and molecularly based on the uidA gene responsible for beta-glucuronidase activity. The virulence genes were determined by polymerase chain reaction.

Findings

The prevalence in vegetable salads of E. coli with virulence genes was 35.3 percent. The distribution of pathovars was 21.2 percent enterotoxigenic (ETEC), 4.9 percent enteropathogenic (EPEC), 0.7 percent Shigatoxigenic (STEC), and 7.5 percent Enteroaggregative E. coli (EAEC). It appears from the study that vegetable salads sold in collective catering in Abidjan are at risk for contamination by E. coli pathovars.

Originality/value

Processing conditions for these salads during preparation appear to be hygienically insufficient, so measures to control the risk of contamination are necessary.

Details

British Food Journal, vol. 120 no. 12
Type: Research Article
ISSN: 0007-070X

Keywords

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Abstract

Purpose

Broad-spectrum cephalosporin resistance is rapidly increasing in Escherichia coli, representing a food safety problem. The purpose of this paper is to characterize eight extended-spectrum-ß-lactamase (ESBL) and acquired AmpC ß-lactamase-producing E. coli isolates and virotypes associated, obtained from chicken and pork food samples in Puebla, Mexico.

Design/methodology/approach

Samples (36 from chicken and 10 from pork) were cultured on Levine agar plates supplemented with cefotaxime (2 mg/L) for isolation of cefotaxime-resistant (CTXR) E. coli. CTXR-E. coli isolates were detected in 33 of 46 samples (72 percent), and one isolate/sample was characterized (28 from chicken and 5 from pork), for ESBL production, phylogenetic group, sequence typing, resistance and virulence genes by PCR and sequencing.

Findings

Results showed 16 ESBL-E. coli (35 percent) (12/16 belonging to phylogroup B1) and 8 CMY-2-E. coli (17 percent). ESBL detected were as follows (number of isolates): CTX-M-2 (8); CTX-M-1 (2); CTX-M-15 (1); SHV-2a (4) and TEM-52c (1). In total, 20 different sequence types (STs) were identified among the ESBL- or CMY-2-producing E. coli strains, which included four new ones. The CTX-M-15 β-lactamase was detected in one E. coli ST617-ST10 Cplx-B1 strain that also carried ibeA gene. One CMY-2-positive strain of lineage ST224-B2 was detected and it carried the qnrA1 gene.

Originality/value

In this study, a ST131-based virotyping scheme for strains from food of animal origin was established since this kind of strains constitutes an important vehicle of virulent ESBL- and CMY-2-producing E. coli isolates, which could be transmitted to humans by direct contact or through the food chain.

Details

British Food Journal, vol. 120 no. 7
Type: Research Article
ISSN: 0007-070X

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Article

Shajuty Marjan, Kamal Kanta Das, Saurab Kishore Munshi and Rashed Noor

– Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues.

Abstract

Purpose

Current study was carried to detect the presence of pathogenic bacteria including the drug-resistant ones from milk and milk products. The paper aims to discuss these issues.

Design/methodology/approach

Twenty-six raw milk samples from ten different areas, 28 pasteurized milk samples from 12 different companies and 26 yogurt samples from ten different sources in Dhaka city were microbiologically analyzed through cultural and biochemical identification of the isolates. Drug resistance trait was also determined by the Kirby-Bauer method on Muller-Hinton agar.

Findings

Out of 80 samples studied, 74 were found to harbor pathogens within a range of 102-104 cfu/ml, including Escherichia coli, Salmonella spp., Staphylococcus aureus, and Vibrio spp. The study of antibiogram revealed that most of the isolates were resistant against most of the commonly used antibiotics.

Research limitations/implications

Employment of only cultural/ biochemical tests excluding the molecular detection of virulence and/or antibiotic resistance genes might stand as a shortfall of the study. Nevertheless, such basic approach of microbiology can make this type of study replicable in the resource poor settings in the other developing countries.

Practical implications

Routine detection of drug-resistant bacteria can further unveil the complications in chemotherapy during the endemic food borne diseases.

Social implications

The study outcome/knowledge would aid to a better public health management especially in the developing countries.

Originality/value

The presence of drug-resistant pathogenic bacteria in most of the tested milk samples poses a great public health threat, especially to the children. Therefore, the study revealed the necessity of maintaining proper hygienic practice and care in handling and processing of milk and milk products.

Details

Nutrition & Food Science, vol. 44 no. 3
Type: Research Article
ISSN: 0034-6659

Keywords

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Article

Nick Carpita

A meeting report on the Keystone Symposium “Systems Approach to Plant Biology”, Big Sky, Montana, 26‐31 January, 2001. This symposium, sponsored by several plant biotech…

Abstract

A meeting report on the Keystone Symposium “Systems Approach to Plant Biology”, Big Sky, Montana, 26‐31 January, 2001. This symposium, sponsored by several plant biotech companies, brought together both industrial and academic researchers to plot bolder strategies for high‐throughput plant biological research. Broad‐ranging discussions covered historical discoveries, recent developments and exciting new trends that are emerging in this highly dynamic field. Participants from around the world appeared to be energized by the exciting possibilities for determining and, ultimately, controlling metabolic pathways and processes while recognizing that there is still much to do in order to understand the biological systems of all known genes.

Details

British Food Journal, vol. 103 no. 11
Type: Research Article
ISSN: 0007-070X

Keywords

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Article

Md. Sajjad Alam, Farahnaaz Feroz, Hasibur Rahman, Kamal Kanta Das and Rashed Noor

The purpose of the paper is to emphasize on contamination sources of freshly cultivated vegetables commonly consumed by the Bangladeshi people. Several local studies have…

Abstract

Purpose

The purpose of the paper is to emphasize on contamination sources of freshly cultivated vegetables commonly consumed by the Bangladeshi people. Several local studies have been conducted to detect the microbial contamination within fresh vegetables, plantation lands and the irrigation waters separately; however, the correlation of microbial contamination between the fresh produces and the surrounding environment has not been clarified.

Design/methodology/approach

Bottle gourd (Lagenaria siceraria), pumpkin (Cucurbita pepo), radish (Raphanus sativus) and eggplant (Solanum melongena); their plantations soils and the fertilizers applied across the agricultural lands; and, finally, the irrigation waters used were analyzed from nine districts of Bangladesh using conventional microbiological and biochemical methods.

Findings

Almost all vegetable samples studied were found to be immensely contaminated with bacteria and fungi. Among the pathogens, Klebsiella spp., Staphylococcus spp. and Pseudomonas spp. were found to be dominant. Besides, massive microbial growth was also observed in the plantation soils and fertilizers, including Klebsiella spp., Pseudomonas spp., Bacillus spp., Listeria spp., Escherichia coli and Vibrio spp. Existence of the fecal coliforms, E. coli, Klebsiella spp., Salmonella spp. and Listeria spp., was noticed in the irrigation waters.

Research limitations/implications

Although the present study revealed the combined results connecting the vegetable contamination aspect with the knowledge on microbiology ultimately in the food chain, implementation of molecular studies detecting the virulence genes both in the fresh produces and the plantation soils, fertilizers and the irrigation waters would further clarify the microbial dissemination mechanism.

Practical implications

Earlier studies demonstrated the ability of water bodies to disseminate numerous microorganisms into the plantation soils, and to some extent unraveled the ability of organic fertilizers to propagate pathogenic bacteria into the vegetation objects. These microorganisms may pose as a threat to vegetables, particularly by limiting crop production as well as the shelf life of the fresh produces.

Social implications

The scenario of microbial divergence not only in the vegetables but also within the surroundings is gradually being heightened in Bangladesh principally due to the malpractice of sanitation, dumping the agricultural lands with feces, improperly controlled septic systems, waste water runoff across the agricultural lands, etc. Therefore, the preliminary and replicable experimental approach described in the current study would be feasible for all other developing countries to maintain the public health safety.

Originality/value

Growth and proliferation of microorganisms both in the vegetable samples and the environmental samples nearly to a similar extent indeed projected for the first time in Bangladesh, the agricultural perspective of the contamination sources of vegetables. Such knowledge would aid in the existing knowledge on the hygienic processing during crop production and harvesting for the sake of better consumer safety management.

Details

Nutrition & Food Science, vol. 45 no. 4
Type: Research Article
ISSN: 0034-6659

Keywords

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Article

Swati Singh, Ankur Kaushal and Ashok Kumar

There is an immense concern in the international community about controlling the outburst of infectious diseases. An essential step towards diminishing it is the…

Abstract

Purpose

There is an immense concern in the international community about controlling the outburst of infectious diseases. An essential step towards diminishing it is the development of an adequate detection system. Among the huge plethora of microorganisms which may infect the human body, Streptococcus pyogenes is important one which infects the upper respiratory tract leading to sore throat, which eventually develops into rheumatic heart disease (RHD) in the absence of timely treatment. A major process in controlling the infection is to detect it at an early stage. Hence, there is a need to develop detection tools which are both rapid and reliable.

Design/methodology/approach

Different types of diagnostic methods are available for identification, but the most commonly used are culturing, staining and rapid antigen detection tests. For better sensitivity and specificity, this review describes the development of biosensor. Compared with the current available methods, which are usually cumbersome, time-consuming and expensive, this approach features sequence specificity, cost efficiency, rapid and ease of use.

Findings

This review outlines various sensors which are available for the detection of Streptococcus pyogenes which causes human RHD. The working scheme of the sensors, their sensitivity and limitation of detection has been described in the review.

Originality/value

The review fulfills an acknowledged the need to study various sensors that are available for the detection of Streptococcus pyogenes, causing human RHD.

Details

Sensor Review, vol. 38 no. 1
Type: Research Article
ISSN: 0260-2288

Keywords

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Article

Seyedeh Maryam Mousavi, Bita Archangi, Hosein Zolgharnein and Isaac Zamani

The purpose of this paper was to identify Serratia marcescens to extract and purify prodigiosin pigment to evaluate the antibacterial potential of the pigment.

Abstract

Purpose

The purpose of this paper was to identify Serratia marcescens to extract and purify prodigiosin pigment to evaluate the antibacterial potential of the pigment.

Design/methodology/approach

Samples were collected from shrimp aquaculture ponds. Species identification was conducted using morphological, biochemical and molecular tests. Pigment extraction and purification were carried out using column chromatography. The antibacterial effect of crude and purified prodigiosin pigment was evaluated on Escherichia coli, Bacillus subtilis, Pseudomonas aeruginosa and Staphylococcus aureus as biofouling bacteria. In addition, the interaction between prodigiosin and proteins involved in biofilm formation was evaluated using molecular docking.

Findings

The results of prodigiosin extraction with solvents showed the highest percentage of pigment presence with methanol solvent in the second day of culture. The chemical structure of pure prodigiosin obtained from the column chromatography was confirmed by Fourier-transform infrared spectroscopy. Both crude and purified pigments exhibited antibacterial effects against selected bacterial strains. The antibacterial effect of the purified pigment was higher, and the highest antibacterial effect was observed on B. subtilis. Prodigiosin docking was carried out with all target proteins, and the docked energy in all of them was at an acceptable level.

Originality/value

Prodigiosin extracted from S. marcescens can be used as a bioactive compound to design and manufacture of anti-biofouling and anti-biofilm formation products to use extensively for industrial applications as a natural color in marine industries, food industry, cosmetics and textile productions.

Details

Pigment & Resin Technology, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0369-9420

Keywords

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Article

Larry R. Beuchat

Food and water safety is a major international concern. Among the food groups implicated with greater frequency in recent years as having caused or been associated with…

Abstract

Purpose

Food and water safety is a major international concern. Among the food groups implicated with greater frequency in recent years as having caused or been associated with enteric diseases in humans are raw fruits and vegetables. Outbreaks of diseases caused by infectious and toxigenic bacteria as well as parasites and viruses have been documented to occur as a result of consumption of contaminated produce. This paper seeks to review the scientific literature reporting evidence to support the potential for preharvest contamination of fruits and vegetables intended to be eaten raw.

Design/methodology/approach

Sources of preharvest contamination of produce include manure, manure compost, sewage sludge, irrigation water, runoff water from livestock operations, and wild and domestic animals. Literature was reviewed to assess the conditions affecting survival of pathogenic microorganisms originating from these sources in preharvest environments and potential for contamination of produce before or at the time of harvest.

Findings

Prevention of preharvest contamination is essential to minimizing the risk of illness caused by consuming raw produce because postharvest treatment with sanitizers cannot be relied upon to eliminate pathogens.

Originality/value

A better understanding of the behaviour of pathogens in preharvest environments will enhance the prospect of developing effective strategies and interventions that will assure the delivery of safe produce to the consumer.

Details

British Food Journal, vol. 108 no. 1
Type: Research Article
ISSN: 0007-070X

Keywords

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Abstract

Details

Infusing Undergraduate Research into Historically Black Colleges and Universities Curricula
Type: Book
ISBN: 978-1-78560-159-0

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