Human pathogens associated with raw produce and unpasteurized juices, and difficulties in decontamination

The ability of public health agencies to identify, through enhanced epidemiologic and surveillance techniques, raw fruits, vegetables, and unpasteurized juices as probable sources of infectious microorganisms, has undoubtedly resulted in increased numbers of documented outbreaks. Changes in agronomic, harvesting, distribution, processing, and consumption patterns and practices have also likely contributed to this increase. The risk of illness associated with raw produce and unpasteurized produce products can be reduced by controlling or preventing contamination, or by removing or killing pathogenic microorganisms by washing or treating them with sanitizers. However, the hydrophobic cutin, diverse surface morphologies, and abrasions in the epidermis of fruits and vegetables limit the efficacy of these treatments. Journal of Industrial Microbiology & Biotechnology (2001) 27, 104–110. Received 23 June 2000/ Accepted in revised form 17 October 2000     

Enteric virus contamination of foods through industrial practices: a primer on intervention strategies

Hepatitis A and E viruses, rotaviruses, Norwalk-like caliciviruses, and astroviruses are among the enteric viruses known to cause food- and waterborne illness. These viruses are spread by the fecal–oral route and are a major cause of morbidity and mortality worldwide. Foods may be contaminated at any time pre- or post-harvest; however, many outbreaks are associated with foods handled by infected restaurant workers. Produce may be contaminated by improper irrigation or fertilization practices, by the hands of infected pickers or processors, or as the result of adulteration during any stage of handling. Outbreaks have been commonly associated with foods which are served raw or only lightly cooked, such as molluscan shellfish, fruits and vegetables, and salads or products contaminated after cooking like frosted bakery products. The farming, shellfish, processing, transportation, and restaurant industries must maintain vigilance to reduce outbreaks of enteric virus illness. Intervention strategies to enhance product safety include increased industry and consumer education; changes in industrial practices, product management, and processing technologies; worker immunizations; and the development of improved monitoring tools for the detection of enteric viruses in foods. Journal of Industrial Microbiology & Biotechnology (2001) 27, 117–125. Received 23 June 2000/ Accepted in revised form 22 September 2000     

Ecological factors influencing survival and growth of human pathogens on raw fruits and vegetables

Outbreaks of human infections associated with consumption of raw fruits and vegetables have occurred with increased frequency during the past decade. Factors contributing to this increase may include changes in agronomic and processing practices, an increase in per capita consumption of raw or minimally processed fruits and vegetables, increased international trade and distribution, and an increase in the number of immuno-compromised consumers. A general lack of efficacy of sanitizers in removing or killing pathogens on raw fruits and vegetables has been attributed, in part, to their inaccessibility to locations within structures and tissues that may harbor pathogens. Understanding the ecology of pathogens and naturally occurring microorganisms is essential before interventions for elimination or control of growth can be devised.     

Changes in Intake of Fruits and Vegetables and Weight Change in United States Men and Women Followed for Up to 24 Years: Analysis from Three Prospective Cohort Studies

BackgroundCurrent dietary guidelines recommend eating a variety of fruits and vegetables. However, based on nutrient composition, some particular fruits and vegetables may be more or less beneficial for maintaining or achieving a healthy weight. We hypothesized that greater consumption of fruits and vegetables with a higher fiber content or lower glycemic load would be more strongly associated with a healthy weight.ConclusionsIncreased consumption of fruits and non-starchy vegetables is inversely associated with weight change, with important differences by type suggesting that other characteristics of these foods influence the magnitude of their association with weight change.     

Detection of Klebsiella pneumoniae antibiotic-resistant genes: An impending source of multidrug resistance dissemination through raw food

This study aimed to find out the prevalence and antimicrobial resistance profile of Klebsiella pneumoniae in raw food items. A total of 261 raw food items, including vegetables, fruits, meat, and milk samples, were collected and processed for isolation of K. pneumoniae. Further antimicrobial susceptibility testing and molecular analysis was done to analyze the drug resistance encoding genes. The prevalence rate of K. pneumoniae was found to be high (38%), and the raw milk samples were predominantly contaminated (19/51), followed by fruits (12/51), meat (11/51), and vegetables (9/51). However, no significant association was observed for the isolation of K. pneumoniae and any particular specimen. Among the isolates, 43% were extended-spectrum β-lactamase producers, 24% were AmpC, and 20% were carbapenemase producers. The highest rates of ESBLs and AmpC were observed in vegetables (cabbage, bell pepper, and spinach) and carbapenemases in raw chicken, fish, and raw meat samples. Notably, bla_CTX-M was the most prevalent, followed by bla_SHV and bla_TEM. Six K. pneumoniae possessed bla_MOX, and five possessed bla_FOX genes. Numerous carbapenemases were identified with a higher proportion of bla_NDM. This study indicates that raw vegetables, fruits, meat, and milk are exposed to contaminants. These findings imply a potential threat that drug-resistant K. pneumoniae pathogens could transmit to humans through raw vegetables, fruits, and meat.     

Effects of vegetable type, package atmosphere and storage temperature on growth and survival of Escherichia coli O157:H7 and Listeria monocytogenes

The survival and growth of Escherichia coli O157:H7 (ATCC 43888 and NCTC 12900) and Listeria monocytogenes (ATCC 19114 and NCTC 11994) during storage (4 and 8°C) on ready-to-use (RTU) packaged vegetables (lettuce, swedes (rutabaga), dry coleslaw mix, soybean sprouts) were studied. The vegetables were sealed within oriented polypropylene packaging film, and modified atmospheres developed in packs during storage due to produce respiration. Survival and growth patterns were dependent on vegetable type, package atmosphere, storage temperature and bacterial strain. Populations of L. monocytogenes and E. coli O157:H7 increased (P<0.05, by 1.5 to 2.5 log cycles, depending on strain) during a 12-day storage period on shredded lettuce (8°C). L. monocytogenes populations also increased (by ∼1 log cycle) on packaged swedes, did not change significantly (P>0.05) in packages of soybean sprouts and decreased by ∼1.5 log cycles (P<0.05) on coleslaw mix (8°C). E. coli O157:H7 populations on packaged coleslaw and soybean sprouts increased (by 1.5 to 2.5 log cycles) up to day 5, but declined during subsequent storage (8°C). On packaged swedes (8°C), populations of E. coli O157:H7 strain ATCC 43888 increased (by ∼1 log cycle) during storage, whereas populations of strain 12900 increased between days 2 and 5, and declined during subsequent storage. Reducing the storage temperature from 8 to 4°C reduced the growth of L. monocytogenes and E. coli O157:H7 on packaged RTU vegetables. However, viable populations remained at the end of the storage period at 4°C. Journal of Industrial Microbiology & Biotechnology (2001) 27, 111–116. Received 25 May 2000/ Accepted in revised form 21 September 2000     

以pH为扰动因子探究电化学厌氧消化产甲烷代谢通量与微生物的关系

【背景】电化学厌氧消化(electrochemical anaerobic digestion,EAD)系统的代谢途径由具备不同功能的微生物所主导,其代谢通量与功能微生物丰度、活性及群落结构相关。【目的】探究EAD产甲烷代谢通量与微生物的关系。【方法】采用代谢通量分析(metabolic flux analysis,MFA)方法,以pH为扰动因子得到微生物群落与产甲烷通量的响应关系。【结果】pH 7.5扰动时产甲烷通量最大为0.398 4±0.029 3,较对照组(pH 6.9)的0.297 4±0.012 7和扰动组(pH 6.3)的0.136 5±0.012 0分别提高了25%和65%。另外,平均有33.8%±3.1%的氢气(通量)用于还原二氧化碳产甲烷和乙酸,平均有21.0%±2.6%的乙酸(通量)转化为甲烷。此外,产甲烷通量与Mariniphaga、Methanosaeta和Desulfomicrobium的丰度呈正相关,与Sedimentibacter的丰度呈负相关且影响显著。【结论】在EAD产甲烷体系中产甲烷菌和产酸菌共存时,pH值略大于7.0的环境有利于甲烷的生成,改变E...     

Effect of Pattern and Duration of Breastfeeding on the Consumption of Fruits and Vegetables among Preschool Children

Background

The duration and pattern of breastfeeding can influence the consumption of fruits and vegetables in later childhood.

Objective

To investigate the association between pattern and duration of breastfeeding and consumption of fruits and vegetables in children aged between 4 and 7 years.

Methods

We conducted a secondary analysis using data from a former randomized clinical trial with 323 adolescent mothers, their children, and maternal grandmothers, when they cohabited. Information on infant feeding was collected monthly during the first 6 months of life, every two months until the child was 1 year old over and when children were between 4 and 7 years old. The associations between duration of breastfeeding and exclusive breastfeeding and consumption of fruits and vegetables were tested by a logistic regression model.

Results

Approximately 60% and 45% of children consumed fruits and vegetables, respectively, five or more times a week. Consumption of vegetables among 4-7-year-old children was higher in children who were breastfed for 12 months or longer (OR 2.7; 95%CI 1.49–4.93); however, exclusive breastfeeding duration did not have a significant association with consumption of vegetables (OR 1.5; 95%CI 0.70–3.04). There was no association between weekly consumption of fruits and duration of breastfeeding (OR 1.3; 95%CI 0.71–2.30) or exclusive breastfeeding (OR 0.7; 95%CI 0.34–1.44).

Conclusions

Longer duration of breastfeeding was positively associated with consumption of vegetables in children aged 4–7 years; however, there was no association with consumption of fruits. Exclusive breastfeeding duration did not have influence on consumption of fruits or vegetables.     

Biosurfactant-enhanced degradation of residual hydrocarbons from ship bilge wastes

The use of Bacillus subtilis O9 biosurfactant (surfactin) and of bioaugmentation to improve the treatment of residual hydrocarbons from ship bilge wastes was studied. A biodegradation experiment was conducted in aquaria placed outdoors under non-aseptic conditions. Three treatments were examined: culture medium plus bilge wastes, bioaugmentation with microorganisms from bilge wastes, and bioaugmentation plus biosurfactant. Samples were analyzed for viable counts, aliphatic and aromatic hydrocarbon concentrations, n-C17/pristane and n-C18/phytane ratios. While the addition of biosurfactant stimulated hydrocarbon degradation, bioaugmentation did not produce any remarkable effect. At day 10, the remaining percentages of aliphatic and aromatic hydrocarbons in aquaria, which received biosurfactant, were 6.8 and 7.2, respectively, while it took 20 days to reach comparable results with the other treatments. The biosurfactant did not affect the preferential biodegradation of n-C17/pristane and n-C18/phytane. This biosurfactant, which can be produced in a relatively simple and inexpensive process, is a promising alternative in the optimization of hydrocarbon waste treatment. Journal of Industrial Microbiology & Biotechnology (2000) 25, 70–73. Received 26 January 2000/ Accepted in revised form 09 June 2000     

Characterization of mannitol producing strains of Leuconostoc species

Mannitol is a naturally occurring low calorie sweetener, widely used in the food, pharmaceutical, medicine and chemical industries. In this study mannitol producing strains of Leuconostoc spp. (210) were isolated from a wide array of sources such as raw milk, fermented milks, fermented cereal foods, fruits, vegetables and sugar factory syrup. During initial screening, half of the population of these isolates (105) exhibited ability to produce mannitol to a variable extent. Only 11.4% isolate produced mannitol yield of above 80% (when fructose used @ 50 g/l). Cultural and environmental factors affecting growth and mannitol production were studied for four high mannitol producing isolates. High mannitol production was favored by high temperature and high pH. Isolates had high osmotic tolerance as these could use fructose concentration as high as 100 g/l in batch culture. Sequencing of 16S rRNA genes of the strains revealed that Ln27, Ln104 and Ln206 were Leuconostoc mesenteroides and Ln92 was Leuconostoc fallax.     

北疆传统发酵生奶酪中乳酸菌的耐受性及益生特性测定

【背景】北疆乳制品中生奶酪作为发酵乳制品,其中有多种微生物的参与,是优质食品级微生物的宝贵来源,然而其中蕴含的丰富的微生物资源也面临着流失。【目的】研究已筛选出的41株乳酸菌的生长曲线变化规律,并对其在低pH环境的耐酸特性及益生特性进行分析。【方法】通过人工模拟胃肠液和含0.3%、0.5%、1.0%浓度牛胆盐溶液培养,对从生奶酪中分离鉴定的41株乳酸菌菌株进行人工胃肠液、牛胆盐耐受性试验。【结果】41株乳酸菌中有6株乳酸菌(编号为QM-5、QM-27、UM-12、UM-18、NM-11和NM-14)均能在pH值分别为2.0、2.5、3.0、3.5、4.0时生长较好,在pH 2.0的环境下也保持一定程度的生长。菌株存活率大于50%,乳酸菌含量为108 CFU/mL以上。从生奶酪分离的乳酸菌有极强的耐酸、耐胆盐特性,可以预测在胃肠道环境生存。41株菌对大肠杆菌(Escherichia coli)、金黄色葡萄球菌(Staphylococcus aureus)和枯草芽孢杆菌(Bacillus subtilis)均有抑制作用。【结论】通过比较耐酸性、胃肠道模拟、胆盐耐受性和抑菌特性等实验结果,初...     

Waterpipe Tobacco Smoking and Gastric Cancer Risk among Vietnamese Men

BackgroundThe association of waterpipe tobacco (WPT) smoking with gastric cancer (GC) risk was suggested.MethodsA hospital-based case-control study was conducted to examine the association of WPT with GC risk among Vietnamese men, in Hanoi city, during the period of 2003–2011. Newly-diagnosed GC cases (n = 454) and control patients (n = 628) were matched by age (+/- 5 years) and the year of hospitalization. Information on smoking and alcohol drinking habits and diet including salty food intake and fruits/vegetables consumption were obtained by the interview. Maximum likelihood estimates of odds ratios (ORs) and corresponding 95% confidence intervals (Cis) were obtained using conditional logistic regression models.ResultsThe group with the highest consumption of citrus fruits showed a significantly low GC risk (OR = 0.6, 95%CI = 0.4–0.8, P for trend = 0.002). However, there was no association of raw vegetable consumption with GC risk. Referring to never smokers, GC risk was significantly higher in current WPT smokers (OR = 1.8, 95%CI = 1.3–2.4), and it was more evident in exclusively WPT smokers (OR = 2.7, 95%CI = 1.2–6.5). GC risk tended to be higher with daily frequency and longer duration of WPT smoking but these trends were not statistically significant (P for trend: 0.144 and 0.154, respectively). GC risk of those who started smoking WPT before the age of 25 was also significantly high (OR = 3.7, 95%CI = 1.2–11.3). Neither cigarette smoking nor alcohol drinking was related to GC risk.ConclusionThe present findings revealed that WPT smoking was positively associated with GC risk in Vietnamese men.     

Fleisch als Nahrung von Gestreiften Mausv?geln (Colius striatus) im Freiland

Summary Mousebirds are usually regarded to consume vegetables and fruits only. Therefore it is of interest, that at least 4 free-living Speckled Mousebirds (Colius striatus) could be observed at Mountain-Lodge/Mt. Kenya feeding greater amounts of cooked and raw meat, which was deposed to attract carnivore animals.     

Role of Chrysonilia sitophila in the quality of cork stoppers for sealing wine bottles

The contribution of Chrysonilia sitophila in cork stopper manufacture was studied and a simulation of the industrial processing of cork stoppers was performed. Stoppers cut from slabs where mold development was inhibited were compared with others cut from slabs colonized by C. sitophila alone or with several molds, in terms of physical properties and chemical taints. C. sitophila does not produce 2,4,6-trichloroanisole, guaiacol, or 1-octene-3-ol on cork slabs incubated for 66 days. Since some chlorophenol-related compounds contaminate cork slabs during the production processes, metabolic tests were performed to investigate the capability of molds to produce 2,4,6-trichloroanisole by methylation of 2,4,6-trichlorophenol. Degradation of 2,4,6-trichlorophenol by C. sitophila resulted in a very high level of degradation without production of 2,4,6-trichloroanisole. C. sitophila restricted growth of other molds on maturing slabs for at least 30 days. These results show that C. sitophila can be exploited by industrial producers of cork stoppers since it is able to inhibit the development of other molds and it does not produce the compounds responsible for ‘cork-taint’, even in the presence of chlorophenols. Journal of Industrial Microbiology & Biotechnology (2000) 24, 256–261. Received 28 July 1999/ Accepted in revised form 05 January 2000     

Occurrence and diversity of entomopathogenic fungi in cultivated and uncultivated soils in Pakistan

The distribution of entomopathogenic fungi in various geographical areas of Punjab, Pakistan, is poorly understood. The present study was planned to explore the occurrence and diversity of entomopathogenic fungi from soils collected from cultivated and non‐cultivated habitats. The detailed survey of different habitats (crop fields, fruits, vegetables, forests) was conducted to collect soil samples and the associated fungi were isolated using Galleria bait method. Among 210 soil samples, 168 fungal isolates were recovered and identified, with 98 from forests, 32 from vegetables, 30 from field crops and 8 from fruits. The major entomopathogenic fungi recovered from these samples were Beauveria bassiana, Metarhizium anisopliae, Paecilomyces lilacinus, B. brongniartii, P. chlamydosporia and Lecanicillium attenuatum. The diversity of entomopathogenic fungi was greater in soil samples from forests compared to crop fields, vegetables and fruits, respectively. The geographical attributes (altitude, longitude, latitude) greatly influenced the occurrence of entomopathogenic fungi with the highest number of isolates found from >600 m altitude, 33°–34′N latitude, and 73°74′E longitude from soil samples. The results of the surveys clearly indicated that the entomopathogenic fungi are distributed in the soils which may be used in successful IPM programs in future.     

Microbial reduction of alpha-chloroketone to alpha-chlorohydrin

Microbial reduction of α-chloroketone to α-chlorohydrin was studied as one of the approaches for construction of the chiral center of the corresponding epoxide. About 100 microorganisms covering many species of Candida, Pichia, Hansenula, Geotrichum, Rhodococcus and Aureobasidium were screened to reduce the α-chloroketone stereospecifically. Many strains provided the R-α-chlorohydrin with 100% enantiomeric excess (ee), e.g., Candida sonorensis SC 16117, Geotrichum candidum SC 5469, Rhodotorula glutinis SC 16293, Sphingomonas paucimobilis SC 16113, Pichia silvicola SC 16159 and Rhodococcus equi SC 15835. Few microorganisms showed preferential formation of S-α-chlorohydrin after reduction. Among them, Pichia pinus SC 13864 and two Pichia methanolica strains SC 16116 and SC 13860 were the best, providing the S-α-chlorohydrin with ee of 88%, 79% and 78%, respectively. The enantiospecificity of the reduction by these Pichia species can be modified by changing the pH or prior heat treatment of the cells and S-α-chlorohydrin with ≥95% ee was obtained by appropriate modification of reaction conditions. Journal of Industrial Microbiology & Biotechnology (2001) 26, 259–262. Received 23 June 2000/ Accepted in revised form 06 November 2000     

Polysaccharide-specific probes inhibit adhesion of Hyphomonas rosenbergii strain VP-6 to hydrophilic surfaces

Biofilm formation commences with the adhesion of microorganisms to surfaces. Information regarding the initial bond between a bacterium and a solid surface is essential for devising methods to inhibit the onset of biofilm formation. Three different types of polysaccharide-specific probes, cationic metals, dyes, and lectins, were used to bind the exopolysaccharide of Hyphomonas rosenbergii, a budding, prosthecate marine bacterium. Probes, which specifically bind complex carbohydrates, inhibit the adhesion of H. rosenbergii to hydrophilic surfaces. These results suggest that the polysaccharide portion of H. rosenbergii capsular, extracellular polymeric-substance is involved in the primary adhesion process. Journal of Industrial Microbiology & Biotechnology (2000) 25, 81–85. Received 01 February 2000/ Accepted in revised form 03 June 2000     

Frankia inoculation,soil biota,and host tissue amendment influence Casuarina nodulation capacity of a tropical soil

The effects of soil biota, Frankia inoculation and tissue amendment on nodulation capacity of a soil was investigated in a factorial study using bulked soil from beneath a Casuarina cunninghamiana tree and bioassays with C. cunninghamiana seedlings as capture plants. Nodulation capacities were determined from soils incubated in sterile jars at 21 °C for 1, 7, and 28 days, after receiving all combinations of the following treatments: ± steam pasteurization, ± inoculation with Frankia isolate CjI82001, and ± amendment with different concentrations of Casuarina cladode extracts. Soil respiration within sealed containers was determined periodically during the incubation period as a measure of overall microbial activity. Soil respiration, and thus overall microbial activity, was positively correlated with increasing concentrations of Casuarina cladode extracts. The nodulation capacity of soils inoculated with Frankia strain Cj82001 decreased over time, while those of unpasteurized soils without inoculation either increased or remained unaffected. The mean nodulation capacity of unpasteurized soil inoculated with Frankia CjI82001 was two to three times greater than the sum of values for unpasteurized and inoculated pasteurized soils. Our results suggest a positive synergism between soil biota as a whole and Frankia inoculum with respect to host infection.     

Combination of edible vegetable oil and artificial fruit to reduce Bactrocera dorsalis oviposition in chilli fruits

Bactrocera dorsalis (Hendel) is a major pest of a wide variety of fruits and vegetables. This study aimed to evaluate the potency of combining edible vegetable oil application and artificial fruit provision to reduce the oviposition of B. dorsalis in chilli fruits. Experiments were conducted in laboratory using a 20‐L plastic container provided with chilli fruits and in semi field using a fruit‐bearing chilli plant caged with insect screen. The laboratory test revealed that the combination of coconut oil application and artificial fruit provision significantly reduced fruit fly visits, eggs laid and the number of infested chilli fruits no matter when the chilli fruits were without prepuncture or with prepuncture. Further study using a caged chilli plant also found that this combination had significant effects on fruit fly visits and infestation in chilli fruits. These results provide an indication that coconut oil and artificial fruit can work together to reduce fruit fly attacks on chilli fruits. Combining the use of coconut oil and artificial fruit is likely to create an integrated behavioural manipulation (push and pull) of female B. dorsalis that lead to a much lower fruit fly infestation in chilli fruits.