Microbiological contamination sources of freshly cultivated vegetables

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.

Assessment of survival of pathogenic bacteria in fresh vegetables through in vitro challenge test

“…In Bangladesh, such microbial growth simulating research on fresh vegetables is still in its infancy and data are scanty except a few reports (Rahman and Noor 2012;Fatema et al 2013;Ahmed et al 2014;Senjuti et al 2014;Tahera et al 2014;Alam et al 2015). However, in the current study we have further extended our research on the bacterial survival within capsicum, chili, coriander and onion samples.…”

“…Previously we found the fresh vegetables to be contaminated by an array of microorganisms, of which most were resistant against the commonly used antibiotics (Rahman and Noor 2012;Ahmed et al 2014;Alam et al 2015;Noor and Feroz 2015). Conversely, an antibacterial activity of lettuce and cucumber samples against potential pathogenic bacteria was also notable (Ahmed et al 2014).…”

“…Eating a lot of vegetables as part of a low fat and high fiber diet may help reduce blood pressure, risk of heart disease, stroke, diabetes, cancer and manage weight (Gomez and Ricketts 2013). Conversely, raw fresh vegetables like other food items have been reported to come in contact with an array of harmful microorganisms in agricultural land where indusrial and domestic wastes are disposed, during harvesting, transportation and storage and through water bodies that result in the onset of various diseases (Burnett and Beuchat 2001;Guo et al 2002;Solomon et al 2002;Wachtel et al 2002;Nipa et al 2011;Rahman and Noor 2012;Ahmed et al 2014;Feroz et al 2014;Noor et al 2014;Acharjee et al 2015;Alam et al 2015;. Furthermore, contamination and growth of spoilage microorganisms which are usually likely to limit the shelf life of vegetables (King and Bolin 1989;Robbs et al 1996;Uyttendaele et al 2009;Fatema et al 2013;Feroz et al 2013Feroz et al , 2014Noor and Feroz 2015).…”

Food safety in Bangladesh: A microbiological perspective

“…globe, Bangladeshi people are more likely to be prone to microbial attack due to the relatively dense population with extremely unhygienic sanitary facilities (11,31,32). Several researches revealed that the propagation of waterborne microorganisms into the environment causing cholera and diarrhoea is very frequent in this country (32)(33)(34). A recent estimation has revealed that approximately 30 million people in Bangladesh suffer from foodborne illnesses each year (8,35).…”

Microbiological analysis and detection of anti-bacterial activity of Centella asiatica and Aloe vera samples collected from different areas of Dhaka city, Bangladesh

“…In principle, the microbial load of plants is the result of a series of influences caused by animate & inanimate sources and microbial contaminates are easily transferred via air and soil borne vectors (20)(21)(22)(23). Furthermore, original microflora in plants, presence of microorganisms within processing plant, dust, using contaminated water and animal human a excreta, before and after harvest procedure including processing, storage and distribution may be the origins of microbial contamination (20,24). In addition, the collection and handling of medicinal plants does not usually done in sanitary conditions and unhygienic cultivation conditions can increase pollution, influence the maintenance period and destruct the aspect and the potential advantage of medicinal plants (9,25).…”